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  1. Hepatocyte Growth Factor Prevents Acute Renal Failure of Accelerates Renal Regeneration in mice

    Science.gov (United States)

    Kawaida, Kouichi; Matsumoto, Kunio; Shimazu, Hisaaki; Nakamura, Toshikazu

    1994-05-01

    Although acute renal failure is encountered with administration of nephrotoxic drugs, ischemia, or unilateral nephrectomy, there has been no effective drug which can be used in case of acute renal failure. Hepatocyte growth factor (HGF) is a potent hepatotropic factor for liver regeneration and is known to have mitogenic, motogenic, and morphogenic activities for various epithelial cells, including renal tubular cells. Intravenous injection of recombinant human HGF into mice remarkably suppressed increases in blood urea nitrogen and serum creatinine caused by administration of cisplatin, a widely used antitumor drug, or HgCl_2, thereby indicating that HGF strongly prevented the onset of acute renal dysfunction. Moreover, exogenous HGF stimulated DNA synthesis of renal tubular cells after renal injuries caused by HgCl_2 administration and unilateral nephrectomy and induced reconstruction of the normal renal tissue structure in vivo. Taken together with our previous finding that expression of HGF was rapidly induced after renal injuries, these results allow us to conclude that HGF may be the long-sought renotropic factor for renal regeneration and may prove to be effective treatment for patients with renal dysfunction, especially that caused by cisplatin.

  2. Mechanisms of renal cell repair and regeneration after acute renal failure.

    Science.gov (United States)

    Nony, Paul A; Schnellmann, Rick G

    2003-03-01

    In many cases, acute renal failure (ARF) is the result of proximal tubular cell injury and death and can arise in a variety of clinical situations, especially following renal ischemia and drug or toxicant exposure. Although much research has focused on the cellular events leading to ARF, less emphasis has been placed on the mechanisms of renal cell repair and regeneration, although ARF is reversed in over half of those who acquire it. Studies using in vivo and in vitro models have demonstrated the importance of proliferation, migration, and repair of physiological functions of injured renal proximal tubular cells (RPTC) in the reversal of ARF. Growth factors have been shown to produce migration and proliferation of injured RPTC, although the specific mechanisms through which growth factors promote renal regeneration in vivo are unclear. Recently, interactions between integrins and extracellular matrix proteins such as collagen IV were shown to promote the repair of physiological functions in injured RPTC. Specifically, collagen IV synthesis and deposition following cellular injury restored integrin polarity and promoted repair of mitochondrial function and active Na(+) transport. Furthermore, exogenous collagen IV, but not collagen I, fibronectin, or laminin, promoted the repair of physiological functions without stimulating proliferation. These findings suggest the importance of establishing and/or maintaining collagen IV-integrin interactions in the stimulation of repair of physiological functions following sublethal cellular injury. Furthermore, the pathway that stimulates repair is distinct from that of proliferation and migration and may be a viable target for pharmacological intervention.

  3. pbx is required for pole and eye regeneration in planarians.

    Science.gov (United States)

    Chen, Chun-Chieh G; Wang, Irving E; Reddien, Peter W

    2013-02-01

    Planarian regeneration involves regionalized gene expression that specifies the body plan. After amputation, planarians are capable of regenerating new anterior and posterior poles, as well as tissues polarized along the anterior-posterior, dorsal-ventral and medial-lateral axes. Wnt and several Hox genes are expressed at the posterior pole, whereas Wnt inhibitory genes, Fgf inhibitory genes, and prep, which encodes a TALE-family homeodomain protein, are expressed at the anterior pole. We found that Smed-pbx (pbx for short), which encodes a second planarian TALE-family homeodomain transcription factor, is required for restored expression of these genes at anterior and posterior poles during regeneration. Moreover, pbx(RNAi) animals gradually lose pole gene expression during homeostasis. By contrast, pbx was not required for initial anterior-posterior polarized responses to wounds, indicating that pbx is required after wound responses for development and maintenance of poles during regeneration and homeostatic tissue turnover. Independently of the requirement for pbx in pole regeneration, pbx is required for eye precursor formation and, consequently, eye regeneration and eye replacement in homeostasis. Together, these data indicate that pbx promotes pole formation of body axes and formation of regenerative progenitors for eyes.

  4. Macrophages are required for adult salamander limb regeneration.

    Science.gov (United States)

    Godwin, James W; Pinto, Alexander R; Rosenthal, Nadia A

    2013-06-04

    The failure to replace damaged body parts in adult mammals results from a muted growth response and fibrotic scarring. Although infiltrating immune cells play a major role in determining the variable outcome of mammalian wound repair, little is known about the modulation of immune cell signaling in efficiently regenerating species such as the salamander, which can regrow complete body structures as adults. Here we present a comprehensive analysis of immune signaling during limb regeneration in axolotl, an aquatic salamander, and reveal a temporally defined requirement for macrophage infiltration in the regenerative process. Although many features of mammalian cytokine/chemokine signaling are retained in the axolotl, they are more dynamically deployed, with simultaneous induction of inflammatory and anti-inflammatory markers within the first 24 h after limb amputation. Systemic macrophage depletion during this period resulted in wound closure but permanent failure of limb regeneration, associated with extensive fibrosis and disregulation of extracellular matrix component gene expression. Full limb regenerative capacity of failed stumps was restored by reamputation once endogenous macrophage populations had been replenished. Promotion of a regeneration-permissive environment by identification of macrophage-derived therapeutic molecules may therefore aid in the regeneration of damaged body parts in adult mammals.

  5. Understanding kidney morphogenesis to guide renal tissue regeneration.

    Science.gov (United States)

    Little, Melissa H; Combes, Alexander N; Takasato, Minoru

    2016-10-01

    The treatment of renal failure has seen little change in the past 70 years. Patients with end-stage renal disease (ESRD) are treated with renal replacement therapy, including dialysis or organ transplantation. The growing imbalance between the availability of donor organs and prevalence of ESRD is pushing an increasing number of patients to undergo dialysis. Although the prospect of new treatment options for patients through regenerative medicine has long been suggested, advances in the generation of human kidney cell types through the directed differentiation of human pluripotent stem cells over the past 2 years have brought this prospect closer to delivery. These advances are the result of careful research into mammalian embryogenesis. By understanding the decision points made within the embryo to pattern the kidney, it is now possible to recreate self-organizing kidney tissues in vitro. In this Review, we describe the key decision points in kidney development and how these decisions have been mimicked experimentally. Recreation of human nephrons from human pluripotent stem cells opens the door to patient-derived disease models and personalized drug and toxicity screening. In the long term, we hope that these efforts will also result in the generation of bioengineered organs for the treatment of kidney disease.

  6. Towards a Guided Regeneration of Renal Tubules at a Polyester Interstitium

    Directory of Open Access Journals (Sweden)

    Will W. Minuth

    2010-03-01

    Full Text Available Stem/progenitor cells are promising candidates for a therapy of renal failure. However, sound knowledge about implantation and regeneration is lacking. Therefore, mechanisms leading from stem/progenitor cells into tubules are under research. Renal stem/progenitor cells were isolated from neonatal rabbit kidney and mounted between layers of polyester fleece. It creates an artificial interstitium and replaces coating by extracellular matrix proteins. Tubulogenic development is induced by aldosterone. Electron microscopy illuminates growth of tubules in close vicinity to polyester fibers. Tubules contain a differentiated epithelium. The spatial extension of tubules opens a new strategy for testing morphogenic drugs and biocompatible fleece materials.

  7. Axon Regeneration Requires A Conserved MAP Kinase Pathway

    OpenAIRE

    Hammarlund, Marc; Nix, Paola; Hauth, Linda; Jorgensen, Erik M.; Bastiani, Michael

    2009-01-01

    Regeneration of injured neurons can restore function, but most neurons regenerate poorly or not at all. The failure to regenerate in some cases is due to a lack of activation of cell-intrinsic regeneration pathways. Thus, these pathways might be targeted for the development of therapies that can restore neuron function after injury or disease. Here, we show that the DLK-1 MAP kinase pathway is essential for regeneration in C. elegans motor neurons. Loss of this pathway eliminates regeneration...

  8. Development of a porcine renal extracellular matrix scaffold as a platform for kidney regeneration.

    Science.gov (United States)

    Choi, Seock Hwan; Chun, So Young; Chae, Seon Yeong; Kim, Jin Rae; Oh, Se Heang; Chung, Sung Kwang; Lee, Jin Ho; Song, Phil Hyun; Choi, Gyu-Seog; Kim, Tae-Hwan; Kwon, Tae Gyun

    2015-04-01

    Acellular scaffolds, possessing an intact three-dimensional extracellular matrix (ECM) architecture and biochemical components, are promising for regeneration of complex organs, such as the kidney. We have successfully developed a porcine renal acellular scaffold and analyzed its physical/biochemical characteristics, biocompatibility, and kidney reconstructive potential. Segmented porcine kidney cortexes were treated with either 1% (v/v) Triton X-100 (Triton) or sodium dodecyl sulfate (SDS). Scanning electron microscopy showed both treatments preserved native tissue architecture, including porosity and composition. Swelling behavior was higher in the Triton-treated compared with the SDS-treated scaffold. Maximum compressive strength was lower in the Triton-treated compared with the SDS-treated scaffold. Attenuated total reflective-infrared spectroscopy showed the presence of amide II (-NH) in both scaffolds. Furthermore, richer ECM protein and growth factor contents were observed in the Triton-treated compared with SDS-treated scaffold. Primary human kidney cell adherence, viability, and proliferation were enhanced on the Triton-treated scaffold compared with SDS-treated scaffold. Following murine in vivo implantation, tumorigenecity was absent for both scaffolds after 8 weeks and in the Triton-treated scaffold only, glomeruli-like structure formation and neovascularity were observed. We identified 1% Triton X-100 as a more suitable decellularizing agent for porcine renal ECM scaffolds prior to kidney regeneration.

  9. Percutaneous renal puncture: requirements and preliminary results

    CERN Document Server

    Leroy, A; Payan, Y; Richard, F; Chartier-Kastler, E; Troccaz, J; Leroy, Antoine; Mozer, Pierre; Payan, Yohan; Chartier-Kastler, Emmanuel; Troccaz, Jocelyne

    2002-01-01

    This paper introduces the principles of computer assisted percutaneous renal puncture, that would provide the surgeon with an accurate pre-operative 3D planning on CT images and, after a rigid registration with space-localized echographic data, would help him to perform the puncture through an intuitive 2D/3D interface. The whole development stage relied on both CT and US images of a healthy subject. We carried out millimetric registrations on real data, then guidance experiments on a kidney phantom showed encouraging results.

  10. Activation of germline-specific genes is required for limb regeneration in the Mexican axolotl.

    Science.gov (United States)

    Zhu, Wei; Pao, Gerald M; Satoh, Akira; Cummings, Gillian; Monaghan, James R; Harkins, Timothy T; Bryant, Susan V; Randal Voss, S; Gardiner, David M; Hunter, Tony

    2012-10-01

    The capacity for tissue and organ regeneration in humans is dwarfed by comparison to that of salamanders. Emerging evidence suggests that mechanisms learned from the early phase of salamander limb regeneration-wound healing, cellular dedifferentiation and blastemal formation-will reveal therapeutic approaches for tissue regeneration in humans. Here we describe a unique transcriptional fingerprint of regenerating limb tissue in the Mexican axolotl (Ambystoma mexicanum) that is indicative of cellular reprogramming of differentiated cells to a germline-like state. Two genes that are required for self-renewal of germ cells in mice and flies, Piwi-like 1 (PL1) and Piwi-like 2 (PL2), are expressed in limb blastemal cells, the basal layer keratinocytes and the thickened apical epithelial cap in the wound epidermis in the regenerating limb. Depletion of PL1 and PL2 by morpholino oligonucleotides decreased cell proliferation and increased cell death in the blastema leading to a significant retardation of regeneration. Examination of key molecules that are known to be required for limb development or regeneration further revealed that FGF8 is transcriptionally downregulated in the presence of the morpholino oligos, indicating PL1 and PL2 might participate in FGF signaling during limb regeneration. Given the requirement for FGF signaling in limb development and regeneration, the results suggest that PL1 and PL2 function to establish a unique germline-like state that is associated with successful regeneration.

  11. Activation of germline-specific genes is required for limb regeneration in the Mexican axolotl

    Science.gov (United States)

    Zhu, Wei; Pao, Gerald M; Satoh, Akira; Cummings, Gillian; Monaghan, James R; Harkins, Timothy T; Bryant, Susan V; Voss, S Randal; Gardiner, David M; Hunter, Tony

    2013-01-01

    The capacity for tissue and organ regeneration in humans is dwarfed by comparison to that of salamanders. Emerging evidence suggests that mechanisms learned from the early phase of salamander limb regeneration – wound healing, cellular dedifferentiation and blastemal formation – will reveal therapeutic approaches for tissue regeneration in humans. Here we describe a unique transcriptional fingerprint of regenerating limb tissue in the Mexican axolotl (Ambystoma mexicanum) that is indicative of cellular reprogramming of differentiated cells to a germline-like state. Two genes that are required for self-renewal of germ cells in mice and flies, Piwi-like 1 (PL1) and Piwi-like 2 (PL2), are expressed in limb blastemal cells, the basal layer keratinocytes and the thickened apical epithelial cap in the wound epidermis in the regenerating limb. Depletion of PL1 and PL2 by morpholino oligonucleotides decreased cell proliferation and increased cell death in the blastema leading to a significant retardation of regeneration. Examination of key molecules that are known to be required for limb development or regeneration further revealed that FGF8 is transcriptionally downregulated in the presence of the morpholino oligos, indicating PL1 and PL2 might participate in FGF signaling during limb regeneration. Given the requirement for FGF signaling in limb development and regeneration, the results suggest that PL1 and PL2 function to establish a unique germline-like state that is associated with successful regeneration. PMID:22841627

  12. Light Requirement for Shoot Regeneration in Horseradish Hairy Roots 1

    Science.gov (United States)

    Saitou, Tsutomu; Kamada, Hiroshi; Harada, Hiroshi

    1992-01-01

    Hairy roots of horseradish (Armoracia rusticana) were induced by inoculation with Agrobacterium rhizogenes harboring Ri plasmid and cultured on phytohormone-free Murashige and Skoog medium after eliminating the bacteria. Hairy roots grew vigorously and sometimes formed yellowish calli under dark conditions. On the other hand, growth of hairy roots stopped after several weeks of culture with light, then shoots were regenerated. Frequency of shoot formation from hairy roots increased as the culture period in light lengthened and the light intensity increased. The shoot regeneration was induced by treatment with white or red light, but not with far-red light. Shoot regeneration by red light was inhibited by following treatment with far-red light. Red and far-red light reversibly affected shoot regeneration. Excised roots of nontransformed plants grew quite slowly on phytohormone-free Murashige and Skoog medium and occasionally formed shoots under white light conditions. PMID:16669041

  13. Integrins are required for tissue organization and restriction of neurogenesis in regenerating planarians.

    Science.gov (United States)

    Seebeck, Florian; März, Martin; Meyer, Anna-Wiebke; Reuter, Hanna; Vogg, Matthias C; Stehling, Martin; Mildner, Karina; Zeuschner, Dagmar; Rabert, Franziska; Bartscherer, Kerstin

    2017-03-01

    Tissue regeneration depends on proliferative cells and on cues that regulate cell division, differentiation, patterning and the restriction of these processes once regeneration is complete. In planarians, flatworms with high regenerative potential, muscle cells express some of these instructive cues. Here, we show that members of the integrin family of adhesion molecules are required for the integrity of regenerating tissues, including the musculature. Remarkably, in regenerating β1-integrin RNAi planarians, we detected increased numbers of mitotic cells and progenitor cell types, as well as a reduced ability of stem cells and lineage-restricted progenitor cells to accumulate at wound sites. These animals also formed ectopic spheroid structures of neural identity in regenerating heads. Interestingly, those polarized assemblies comprised a variety of neural cells and underwent continuous growth. Our study indicates that integrin-mediated cell adhesion is required for the regenerative formation of organized tissues and for restricting neurogenesis during planarian regeneration.

  14. Macrophages are required for adult salamander limb regeneration

    OpenAIRE

    Godwin, James W.; Pinto, Alexander R.; Nadia A. Rosenthal

    2013-01-01

    The failure to replace damaged body parts in adult mammals results from a muted growth response and fibrotic scarring. Although infiltrating immune cells play a major role in determining the variable outcome of mammalian wound repair, little is known about the modulation of immune cell signaling in efficiently regenerating species such as the salamander, which can regrow complete body structures as adults. Here we present a comprehensive analysis of immune signaling during limb regeneration i...

  15. Smed-betacatenin-1 is required for anteroposterior blastema polarity in planarian regeneration.

    Science.gov (United States)

    Petersen, Christian P; Reddien, Peter W

    2008-01-18

    Planarian flatworms can regenerate heads at anterior-facing wounds and tails at posterior-facing wounds throughout the body. How this regeneration polarity is specified has been a classic problem for more than a century. We identified a planarian gene, Smed-betacatenin-1, that controls regeneration polarity. Posterior-facing blastemas regenerate a head instead of a tail in Smed-betacatenin-1(RNAi) animals. Smed-betacatenin-1 is required after wounding and at any posterior-facing wound for polarity. Additionally, intact Smed-betacatenin-1(RNAi) animals display anteriorization during tissue turnover. Five Wnt genes and a secreted Frizzled-related Wnt antagonist-like gene are expressed in domains along the anteroposterior axis that reset to new positions during regeneration, which suggests that Wnts control polarity through Smed-betacatenin-1. Our data suggest that beta-catenin specifies the posterior character of the anteroposterior axis throughout the Bilateria and specifies regeneration polarity in planarians.

  16. Cognitive dysfunction in patients with renal failure requiring hemodialysis

    Directory of Open Access Journals (Sweden)

    Rohini Thimmaiah

    2012-01-01

    Full Text Available Background and Objectives: Renal failure patients show significant impairment on measures of attention and memory, and consistently perform significantly better on neuropsychological measures of memory and attention, approximately 24 hours after hemodialysis treatment. The objectives are to determine the cognitive dysfunction in patients with renal failure requiring hemodialysis. Materials and Methods: A total of 60 subjects comprising of 30 renal failure patients and 30 controls were recruited. The sample was matched for age, sex, and socioeconomic status. The tools used were the Standardized Mini-Mental State Examination and the Brief Cognitive Rating Scale. Results: The patients showed high cognitive dysfunction in the pre-dialysis group, in all the five dimensions (concentration, recent memory, past memory, orientation and functioning, and self-care, and the least in the 24-hour post dialysis group. This difference was found to be statistically significant (P=0.001. Conclusion: Patients with renal failure exhibited pronounced cognitive impairment and these functions significantly improved after the introduction of hemodialysis.

  17. Mesenchymal stem cell-conditioned medium accelerates regeneration of human renal proximal tubule epithelial cells after gentamicin toxicity.

    Science.gov (United States)

    Moghadasali, Reza; Mutsaers, Henricus A M; Azarnia, Mahnaz; Aghdami, Nasser; Baharvand, Hossein; Torensma, Ruurd; Wilmer, Martijn J G; Masereeuw, Rosalinde

    2013-07-01

    Bone marrow-derived mesenchymal stem cells (MSCs) have the capacity to regenerate renal tubule epithelia and repair renal function without fusing with resident tubular cells. The goal of the present project was to investigate the role of MSCs secreted cytokines on tubule cell viability and regeneration after a toxic insult, using a conditionally immortalized human proximal tubule epithelial cell (ciPTEC) line. Gentamicin was used to induce nephrotoxicity, and cell viability and migration were studied in absence and presence of human MSC-conditioned medium (hMSC-CM) i.e. medium containing soluble factors produced and secreted by MSCs. Exposure of ciPTEC to 0-3000 μg/ml gentamicin for 24 h caused a significant dose-dependent increase in cell death. We further demonstrated that the nephrotoxic effect of 2000 μg/ml gentamicin was recovered partially by exposing cells to hMSC-CM. Moreover, exposure of ciPTEC to gentamicin (1500-3000 μg/ml) for 7 days completely attenuated the migratory capacity of the cells. In addition, following scrape-wounding, cell migration of both untreated and gentamicin-exposed cells was increased in the presence of hMSC-CM, as compared to exposures to normal medium, indicating improved cell recovery. Our data suggest that cytokines secreted by MSCs stimulate renal tubule cell regeneration after nephrotoxicity. Copyright © 2012 Elsevier GmbH. All rights reserved.

  18. teashirt is required for head-versus-tail regeneration polarity in planarians.

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    Owen, Jared H; Wagner, Daniel E; Chen, Chun-Chieh; Petersen, Christian P; Reddien, Peter W

    2015-03-15

    Regeneration requires that the identities of new cells are properly specified to replace missing tissues. The Wnt signaling pathway serves a central role in specifying posterior cell fates during planarian regeneration. We identified a gene encoding a homolog of the Teashirt family of zinc-finger proteins in the planarian Schmidtea mediterranea to be a target of Wnt signaling in intact animals and at posterior-facing wounds. Inhibition of Smed-teashirt (teashirt) by RNA interference (RNAi) resulted in the regeneration of heads in place of tails, a phenotype previously observed with RNAi of the Wnt pathway genes β-catenin-1, wnt1, Dvl-1/2 or wntless. teashirt was required for β-catenin-1-dependent activation of posterior genes during regeneration. These findings identify teashirt as a transcriptional target of Wnt signaling required for Wnt-mediated specification of posterior blastemas.

  19. Erbin is required for myelination in regenerated axons after injury

    OpenAIRE

    2012-01-01

    Neuregulin 1 (NRG1) is an axon-derived factor that is critical for Schwann cell (SC) development and myelinogenesis in a manner dependent on transmembrane tyrosine kinases ErbB2 and ErbB3. Recent studies suggest that NRG1 signaling plays a role in remyelination of regenerated nerves after injury. In this study, we investigated the role of Erbin, a protein that interacts with ErbB2 in remyelination of injured nerves. We show that Erbin expression increased dramatically in injured nerves. Myeli...

  20. In vitro effects of Panax ginseng in aristolochic acid-mediated renal tubulotoxicity: apoptosis versus regeneration.

    Science.gov (United States)

    Bunel, Valérian; Antoine, Marie-Hélène; Nortier, Joëlle; Duez, Pierre; Stévigny, Caroline

    2015-03-01

    This in vitro study aimed to determine the effects of a Panax ginseng extract on aristolochic acid-mediated toxicity in HK-2 cells. A methanolic extract of ginseng (50 µg/mL) was able to reduce cell survival after treatment with 50 µM aristolochic acid for 24, 48, and 72 h, as evidenced by a resazurin reduction assay. This result was confirmed by a flow cytometric evaluation of apoptosis using annexin V-PI staining, and indicated higher apoptosis rates in cells treated with aristolochic acid and P. ginseng extract compared with aristolochic acid alone. However, P. ginseng extract by itself (5 and 50 µg/mL) increased the Ki-67 index, indicating an enhancement in cellular proliferation. Cell cycle analysis excluded a P. ginseng extract-mediated induction of G2/M cell cycle arrest such as the one typically observed with aristolochic acid. Finally, β-catenin acquisition was found to be accelerated when cells were treated with both doses of ginseng, suggesting that the epithelial phenotype of renal proximal tubular epithelial cells was maintained. Also, ginseng treatment (5 and 50 µg/mL) reduced the oxidative stress activity induced by aristolochic acid after 24 and 48 h. These results indicate that the ginseng extract has a protective activity towards the generation of cytotoxic reactive oxygen species induced by aristolochic acid. However, the ginseng-mediated alleviation of oxidative stress did not correlate with a decrease but rather with an increase in aristolochic acid-induced apoptosis and death. This deleterious herb-herb interaction could worsen aristolochic acid tubulotoxicity and reinforce the severity and duration of the injury. Nevertheless, increased cellular proliferation and migration, along with the improvement in the epithelial phenotype maintenance, indicate that ginseng could be useful for improving tubular regeneration and the recovery following drug-induced kidney injury. Such dual activities of ginseng certainly warrant further in vivo

  1. SOCS2 Balances Metabolic and Restorative Requirements during Liver Regeneration.

    Science.gov (United States)

    Masuzaki, Ryota; Zhao, Sophia; Valerius, M Todd; Tsugawa, Daisuke; Oya, Yuki; Ray, Kevin C; Karp, Seth J

    2016-02-12

    After significant injury, the liver must maintain homeostasis during the regenerative process. We hypothesized the existence of mechanisms to limit hepatocyte proliferation after injury to maintain metabolic and synthetic function. A screen for candidates revealed suppressor of cytokine signaling 2 (SOCS2), an inhibitor of growth hormone (GH) signaling, was strongly induced after partial hepatectomy. Using genetic deletion and administration of various factors we investigated the role of SOCS2 during liver regeneration. SOCS2 preserves liver function by restraining the first round of hepatocyte proliferation after partial hepatectomy by preventing increases in growth hormone receptor (GHR) via ubiquitination, suppressing GH pathway activity. At later times, SOCS2 enhances hepatocyte proliferation by modulating a decrease in serum insulin-like growth factor 1 (IGF-1) that allows GH release from the pituitary. SOCS2, therefore, plays a dual role in modulating the rate of hepatocyte proliferation. In particular, this is the first demonstration of an endogenous mechanism to limit hepatocyte proliferation after injury.

  2. MMP-10 is required for efficient muscle regeneration in mouse models of injury and muscular dystrophy.

    Science.gov (United States)

    Bobadilla, Míriam; Sáinz, Neira; Rodriguez, José Antonio; Abizanda, Gloria; Orbe, Josune; de Martino, Alba; García Verdugo, José Manuel; Páramo, José A; Prósper, Felipe; Pérez-Ruiz, Ana

    2014-02-01

    Matrix metalloproteinases (MMPs), a family of endopeptidases that are involved in the degradation of extracellular matrix components, have been implicated in skeletal muscle regeneration. Among the MMPs, MMP-2 and MMP-9 are upregulated in Duchenne muscular dystrophy (DMD), a fatal X-linked muscle disorder. However, inhibition or overexpression of specific MMPs in a mouse model of DMD (mdx) has yielded mixed results regarding disease progression, depending on the MMP studied. Here, we have examined the role of MMP-10 in muscle regeneration during injury and muscular dystrophy. We found that skeletal muscle increases MMP-10 protein expression in response to damage (notexin) or disease (mdx mice), suggesting its role in muscle regeneration. In addition, we found that MMP-10-deficient muscles displayed impaired recruitment of endothelial cells, reduced levels of extracellular matrix proteins, diminished collagen deposition, and decreased fiber size, which collectively contributed to delayed muscle regeneration after injury. Also, MMP-10 knockout in mdx mice led to a deteriorated dystrophic phenotype. Moreover, MMP-10 mRNA silencing in injured muscles (wild-type and mdx) reduced muscle regeneration, while addition of recombinant human MMP-10 accelerated muscle repair, suggesting that MMP-10 is required for efficient muscle regeneration. Furthermore, our data suggest that MMP-10-mediated muscle repair is associated with VEGF/Akt signaling. Thus, our findings indicate that MMP-10 is critical for skeletal muscle maintenance and regeneration during injury and disease.

  3. Keratinocyte growth factor (KGF) is required for postnatal thymic regeneration.

    Science.gov (United States)

    Alpdogan, Onder; Hubbard, Vanessa M; Smith, Odette M; Patel, Neel; Lu, Sydney; Goldberg, Gabrielle L; Gray, Daniel H; Feinman, Jared; Kochman, Adam A; Eng, Jeffrey M; Suh, David; Muriglan, Stephanie J; Boyd, Richard L; van den Brink, Marcel R M

    2006-03-15

    Keratinocyte growth factor (KGF) is a member of the fibroblast growth factor family that mediates epithelial cell proliferation and differentiation in a variety of tissues, including the thymus. We studied the role of KGF in T-cell development with KGF-/- mice and demonstrated that thymic cellularity and the distribution of thymocyte subsets among KGF-/-, wildtype (WT), and KGF+/- mice were similar. However, KGF-/- mice are more vulnerable to sublethal irradiation (450 cGy), and a significant decrease was found in thymic cellularity after irradiation. Defective thymopoiesis and peripheral T-cell reconstitution were found in KGF-/- recipients of syngeneic or allogeneic bone marrow transplant, but using KGF-/- mice as a donor did not affect T-cell development after transplantation. Despite causing an early developmental block in the thymus, administration of KGF to young and old mice enhanced thymopoiesis. Exogenous KGF also accelerated thymic recovery after irradiation, cyclophosphamide, and dexamethasone treatment. Finally, we found that administering KGF before bone marrow transplantation (BMT) resulted in enhanced thymopoiesis and peripheral T-cell numbers in middle-aged recipients of an allogeneic BM transplant. We conclude that KGF plays a critical role in postnatal thymic regeneration and may be useful in treating immune deficiency conditions.

  4. PBX/extradenticle is required to re-establish axial structures and polarity during planarian regeneration.

    Science.gov (United States)

    Blassberg, Robert A; Felix, Daniel A; Tejada-Romero, Belen; Aboobaker, A Aziz

    2013-02-01

    Recent advances in a number of systems suggest many genes involved in orchestrating regeneration are redeployed from similar processes in development, with others being novel to the regeneration process in particular lineages. Of particular importance will be understanding the architecture of regenerative genetic regulatory networks and whether they are conserved across broad phylogenetic distances. Here, we describe the role of the conserved TALE class protein PBX/Extradenticle in planarians, a representative member of the Lophotrocozoa. PBX/Extradenticle proteins play central roles in both embryonic and post-embryonic developmental patterning in both vertebrates and insects, and we demonstrate a broad requirement during planarian regeneration. We observe that Smed-pbx has pleiotropic functions during regeneration, with a primary role in patterning the anterior-posterior (AP) axis and AP polarity. Smed-pbx is required for expression of polarity determinants notum and wnt1 and for correct patterning of the structures polarized along the AP axis, such as the brain, pharynx and gut. Overall, our data suggest that Smed-pbx functions as a central integrator of positional information to drive patterning of regeneration along the body axis.

  5. Characteristics and Outcomes of Granulomatosis With Polyangiitis (Wegener) and Microscopic Polyangiitis Requiring Renal Replacement Therapy: Results From the European Renal Association-European Dialysis and Transplant Association Registry

    NARCIS (Netherlands)

    Hruskova, Z.; Stel, V.S.; Jayne, D.; Aasarod, K.; Meester, J. de; Ekstrand, A.; Eller, K.; Heaf, J.G.; Hoitsma, A.J.; Jimenez, C. Martos; Ravani, P.; Wanner, C.; Tesar, V.; Jager, K.J.

    2015-01-01

    BACKGROUND: This study describes the incidence and outcomes of European patients requiring renal replacement therapy (RRT) for kidney failure due to antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV). STUDY DESIGN: Cohort study. SETTING & PARTICIPANTS: 12 renal registries providi

  6. Successful pregnancy outcome among women with end-stage renal disease requiring haemodialysis.

    Science.gov (United States)

    Arora, Nalini; Mahajan, Kirti; Jana, Narayan; Maiti, Tapan Kumar; Mandal, Debasmita; Pandey, Rajendra

    2009-04-01

    Pregnancy is rare in women with end-stage renal disease, and perinatal outcome remains suboptimal because of prematurity and foetal growth restriction. Successful obstetrical outcome in two women presented with chronic renal failure requiring serial haemodialysis and multiple blood transfusions during pregnancy is reported. Both women had vaginal delivery of low birth weight neonates--2100 g and 1540 g at 33 and 37 weeks' gestations respectively. With specialised neonatal care, both neonates survived, and the mothers were counselled for renal replacement therapy.

  7. Urinary proteomic profiling reveals diclofenac-induced renal injury and hepatic regeneration in mice

    Energy Technology Data Exchange (ETDEWEB)

    Swelm, Rachel P.L. van [Department of Pharmacology and Toxicology, Radboud University Nijmegen Medical Centre, P.O. Box 9101, 6500 HB Nijmegen (Netherlands); Laarakkers, Coby M.M. [Department of Laboratory Medicine, Radboud University Nijmegen Medical Centre, P.O. Box 9101, 6500 HB Nijmegen (Netherlands); Pertijs, Jeanne C.L.M.; Verweij, Vivienne; Masereeuw, Rosalinde [Department of Pharmacology and Toxicology, Radboud University Nijmegen Medical Centre, P.O. Box 9101, 6500 HB Nijmegen (Netherlands); Russel, Frans G.M., E-mail: F.Russel@pharmtox.umcn.nl [Department of Pharmacology and Toxicology, Radboud University Nijmegen Medical Centre, P.O. Box 9101, 6500 HB Nijmegen (Netherlands)

    2013-06-01

    Diclofenac (DF) is a widely used non-steroidal anti-inflammatory drug for the treatment of rheumatic disorders, but is often associated with liver injury. We applied urinary proteomic profiling using MALDI-TOF MS to identify biomarkers for DF-induced hepatotoxicity in mice. Female CH3/HeOUJIco mice were treated with 75 mg/kg bw DF by oral gavage and 24 h urine was collected. Proteins identified in urine of DF-treated mice included epidermal growth factor, transthyretin, kallikrein, clusterin, fatty acid binding protein 1 and urokinase, which are related to liver regeneration but also to kidney injury. Both organs showed enhanced levels of oxidative stress (TBARS, p < 0.01). Kidney injury was confirmed by histology and increased Kim1 and Il-6 mRNA expression levels (p < 0.001 and p < 0.01). Liver histology and plasma ALT levels in DF-treated mice were not different from control, but mRNA expression of Stat3 (p < 0.001) and protein expression of PCNA (p < 0.05) were increased, indicating liver regeneration. In conclusion, urinary proteome analysis revealed that DF treatment in mice induced kidney and liver injury. Within 24 h, however, the liver was able to recover by activating tissue regeneration processes. Hence, the proteins found in urine of DF-treated mice represent kidney damage rather than hepatic injury. - Highlights: • The urinary proteome shows biological processes involved in adverse drug reactions. • Urine proteins of DF-treated mice relate to kidney injury rather than liver injury. • Liver regeneration, not liver injury, is apparent 24h after oral DF administration. • Pretreatment with LPS does not enhance DF-induced liver injury in mice.

  8. Renal Replacement Therapy in Congestive Heart Failure Requiring Left Ventricular Assist Device Augmentation

    OpenAIRE

    Thomas, Bernadette A.; Logar, Christine M.; Anderson, Arthur E.

    2012-01-01

    “Cardiorenal syndrome” is a term used to describe a dys-regulation of the heart affecting the kidneys, or vice versa, in an acute or chronic manner (1,2). Renal impairment can range from reversible ischemic damage to renal failure requiring short- or long-term renal replacement therapy (2). Patients who require mechanical circulatory support, such as a left ventricular assist device (LVAD), as definitive treatment for congestive heart failure or as a bridge to cardiac transplantation pose a u...

  9. Augmenter of liver regeneration inhibits TGF-β1-induced renal tubular epithelial-to-mesenchymal transition via suppressing TβR II expression in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Liao, Xiao-hui [Department of Nephrology, The Second Affiliated Hospital, Chongqing Medical University, Chongqing 400010 (China); Zhang, Ling, E-mail: lindazhang8508@hotmail.com [Department of Nephrology, The Second Affiliated Hospital, Chongqing Medical University, Chongqing 400010 (China); Chen, Guo-tao; Yan, Ru-yu [Department of Nephrology, The Second Affiliated Hospital, Chongqing Medical University, Chongqing 400010 (China); Sun, Hang; Guo, Hui [Institute for Viral Hepatitis, Key Laboratory of Molecular Biology for Infectious Diseases, The Second Affiliated Hospital, Chongqing Medical University, Chongqing 400010 (China); Liu, Qi, E-mail: txzzliuqi@163.com [Institute for Viral Hepatitis, Key Laboratory of Molecular Biology for Infectious Diseases, The Second Affiliated Hospital, Chongqing Medical University, Chongqing 400010 (China)

    2014-10-01

    Tubular epithelial-to-mesenchymal transition (EMT) plays a crucial role in the progression of renal tubular interstitial fibrosis (TIF), which subsequently leads to chronic kidney disease (CKD) and eventually, end-stage renal disease (ESRD). We propose that augmenter of liver regeneration (ALR), a member of the newly discovered ALR/Erv1 protein family shown to ameliorate hepatic fibrosis, plays a similar protective role in renal tubular cells and has potential as a new treatment option for CKD. Here, we showed that recombinant human ALR (rhALR) inhibits EMT in renal tubular cells by antagonizing activation of the transforming growth factor-β1 (TGF-β1) signaling pathway. Further investigation revealed that rhALR suppresses the expression of TGF-β receptor type II (TβR II) and significantly alleviates TGF-β1-induced phosphorylation of Smad2 and nuclear factor-κB (NF-κB). No apparent adverse effects were observed upon the addition of rhALR alone to cells. These findings collectively suggest that ALR plays a role in inhibiting progression of renal tubular EMT, supporting its potential utility as an effective antifibrotic strategy to reverse TIF in CKD. - Highlights: • ALR is involved in the pathological progression of renal EMT in NRK-52E cells. • ALR suppresses the expression of TβRII and the phosphorylation of Smad2 and NF-κB. • ALR plays a role in inhibiting progression of renal tubular EMT.

  10. Dynamics of degeneration and regeneration in developing zebrafish peripheral axons reveals a requirement for extrinsic cell types

    Directory of Open Access Journals (Sweden)

    Villegas Rosario

    2012-06-01

    Full Text Available Abstract Background Understanding the cellular mechanisms regulating axon degeneration and regeneration is crucial for developing treatments for nerve injury and neurodegenerative disease. In neurons, axon degeneration is distinct from cell body death and often precedes or is associated with the onset of disease symptoms. In the peripheral nervous system of both vertebrates and invertebrates, after degeneration of detached fragments, axons can often regenerate to restore function. Many studies of axonal degeneration and regeneration have used in vitro approaches, but the influence of extrinsic cell types on these processes can only be fully addressed in live animals. Because of its simplicity and superficial location, the larval zebrafish posterior lateral line (pLL nerve is an ideal model system for live studies of axon degeneration and regeneration. Results We used laser axotomy and time-lapse imaging of pLL axons to characterize the roles of leukocytes, Schwann cells and target sensory hair cells in axon degeneration and regeneration in vivo. Immune cells were essential for efficient removal of axonal debris after axotomy. Schwann cells were required for proper fasciculation and pathfinding of regenerating axons to their target cells. Intact target hair cells were not themselves required for regeneration, but chemical ablation of neuromasts caused axons to transiently deviate from their normal paths. Conclusions Macrophages, Schwann cells, and target sensory organs are required for distinct aspects of pLL axon degeneration or regeneration in the zebrafish larva. Our work introduces a powerful vertebrate model for analyzing axonal degeneration and regeneration in the living animal and elucidating the role of extrinsic cell types in these processes.

  11. Insulin-like growth factor-1 enhances epidermal growth factor receptor activation and renal tubular cell regeneration in postischemic acute renal failure.

    Science.gov (United States)

    Lin, J J; Cybulsky, A V; Goodyer, P R; Fine, R N; Kaskel, F J

    1995-06-01

    Growth factors such as insulin-like growth factor-1 (IGF-1), epidermal growth factor (EGF), and hepatocyte growth factor have been shown to accelerate the recovery from postischemic acute renal failure (ARF) with a concomitant increase in DNA synthesis. Interactions between growth factors have been demonstrated in a number of in vitro studies. This study examined the effect of exogenous IGF-1 on the DNA synthesis and EGF receptor (EGF-R) activation in postischemic rat kidneys. Thirty minutes after the relief of 30-minute total occlusion of the left renal artery in anesthetized 225 to 300 gm Sprague-Dawley rats, either IGF-1 (75 micrograms/kg) or normal saline solution (NS, 0.2 ml) was given by intravenous bolus, followed by twice daily subcutaneous injections of IGF-1 (50 micrograms/kg) or 0.2 ml NS for 4 days, respectively, in IGF-1-Tx) and NS treated (NS-Tx) groups (n = 8 each). On the day after the completion of treatment, inulin clearance (ml/kg/min) of the postischemic kidneys in the IGF-1-Tx group was significantly higher (p < 0.01) than inulin clearance of kidneys in the NS-Tx group. This was associated with improved kidney morphology. IGF-1 treatment also enhanced the labeling index of 5-bromo-2'-deoxyuridine (percent of stained tubule cells), a marker for active DNA synthesis, in the outer medulla of postischemic kidneys at 1 day and 2 days after the injury. EGF-R tyrosine phosphorylation (which reflects receptor activation) increased in postischemic kidneys in both NS-Tx (n = 5) and IGF-1-Tx (n = 3) groups 1 day after the injury as compared with nonischemic contralateral kidneys. In the IGF-1-Tx group there was also increased iodine 125-labeled EGF binding and EGF-R protein. Our results demonstrate a beneficial effect of IGF-1 on postischemic ARF. Furthermore, they suggest that EGF-R activation is involved in tubular regeneration and that IGF-1 may enhance EGF-R activation by increasing EGF-R expression.

  12. Notch-signalling is required for head regeneration and tentacle patterning in Hydra.

    Science.gov (United States)

    Münder, Sandra; Tischer, Susanne; Grundhuber, Maresa; Büchels, Nathalie; Bruckmeier, Nadine; Eckert, Stefanie; Seefeldt, Carolin A; Prexl, Andrea; Käsbauer, Tina; Böttger, Angelika

    2013-11-01

    Local self-activation and long ranging inhibition provide a mechanism for setting up organising regions as signalling centres for the development of structures in the surrounding tissue. The adult hydra hypostome functions as head organiser. After hydra head removal it is newly formed and complete heads can be regenerated. The molecular components of this organising region involve Wnt-signalling and β-catenin. However, it is not known how correct patterning of hypostome and tentacles are achieved in the hydra head and whether other signals in addition to HyWnt3 are needed for re-establishing the new organiser after head removal. Here we show that Notch-signalling is required for re-establishing the organiser during regeneration and that this is due to its role in restricting tentacle activation. Blocking Notch-signalling leads to the formation of irregular head structures characterised by excess tentacle tissue and aberrant expression of genes that mark the tentacle boundaries. This indicates a role for Notch-signalling in defining the tentacle pattern in the hydra head. Moreover, lateral inhibition by HvNotch and its target HyHes are required for head regeneration and without this the formation of the β-catenin/Wnt dependent head organiser is impaired. Work on prebilaterian model organisms has shown that the Wnt-pathway is important for setting up signalling centres for axial patterning in early multicellular animals. Our data suggest that the integration of Wnt-signalling with Notch-Delta activity was also involved in the evolution of defined body plans in animals.

  13. Yap1, transcription regulator in the Hippo signaling pathway, is required for Xenopus limb bud regeneration.

    Science.gov (United States)

    Hayashi, Shinichi; Tamura, Koji; Yokoyama, Hitoshi

    2014-04-01

    The Hippo signaling pathway is conserved from insects to mammals and is important for multiple processes, including cell proliferation, apoptosis and tissue homeostasis. Hippo signaling is also crucial for regeneration, including intercalary regeneration, of the whole body in the flatworm and of the leg in the cricket. However, its role in vertebrate epimorphic regeneration is unknown. Therefore, to identify principles of regeneration that are conserved among bilaterians, we investigated the role of Hippo signaling in the limb bud regeneration of an anuran amphibian, Xenopus laevis. We found that a transcription factor, Yap1, an important downstream effector of Hippo signaling, is upregulated in the regenerating limb bud. To evaluate Yap1׳s function in limb bud regeneration, we made transgenic animals that expressed a dominant-negative form of Yap under a heat-shock promoter. Overexpression of a dominant-negative form of Yap in tadpoles reduced cell proliferation, induced ectopic apoptosis, perturbed the expression domains of limb-patterning genes including hoxa13, hoxa11, and shh in the regenerating limb bud. Transient expression of a dominant-negative Yap in transgenic tadpoles also caused limb bud regeneration defects, and reduced intercalary regeneration. These results indicate that Yap1 has a crucial role in controlling the limb regenerative capacity in Xenopus, and suggest that the involvement of Hippo signaling in regeneration is conserved between vertebrates and invertebrates. This finding provides molecular evidence that common principles underlie regeneration across phyla, and may contribute to the development of new therapies in regenerative medicine.

  14. Health status, renal function, and quality of life after multiorgan failure and acute kidney injury requiring renal replacement therapy

    Directory of Open Access Journals (Sweden)

    Faulhaber-Walter R

    2016-05-01

    Full Text Available Robert Faulhaber-Walter,1,2 Sebastian Scholz,1,3 Herrmann Haller,1 Jan T Kielstein,1,* Carsten Hafer1,4,* 1Department of Renal and Hypertensive Disease, Medical School Hannover, Hannover, Germany; 2Facharztzentrum Aarberg, Waldshut-Tiengen, Germany; 3Sanitaetsversorgungszentrum Wunstorf, Wunstorf, Germany; 4HELIOS Klinikum Erfurt, Erfurt, Germany *These authors contributed equally to this work Background: Critically ill patients with acute kidney injury (AKI in need of renal replacement therapy (RRT may have a protracted and often incomplete rehabilitation. Their long-term outcome has rarely been investigated. Study design: Survivors of the HANnover Dialysis OUTcome (HANDOUT study were evaluated after 5 years for survival, health status, renal function, and quality of life (QoL. The HANDOUT study had examinded mortality and renal recovery of patients with AKI receiving either standard extendend or intensified dialysis after multi organ failure. Results: One hundred fifty-six former HANDOUT participants were analyzed. In-hospital mortality was 56.4%. Five-year survival after AKI/RRT was 40.1% (86.5% if discharged from hospital. Main causes of death were cardiovascular complications and sepsis. A total of 19 survivors presented to the outpatient department of our clinic and had good renal recovery (mean estimated glomerular filtration rate 72.5±30 mL/min/1.73 m2; mean proteinuria 89±84 mg/d. One person required maintenance dialysis. Seventy-nine percent of the patients had a pathological kidney sonomorphology. The Charlson comorbidity score was 2.2±1.4 and adjusted for age 3.3±2.1 years. Numbers of comorbid conditions averaged 2.38±1.72 per patient (heart failure [52%] > chronic kidney disease/myocardial infarction [each 29%]. Median 36-item short form health survey (SF-36™ index was 0.657 (0.69 physical health/0.66 mental health. Quality-adjusted life-years after 5 years were 3.365. Conclusion: Mortality after severe AKI is higher than

  15. Activation of Smad2 but not Smad3 is required to mediate TGF-β signaling during axolotl limb regeneration.

    Science.gov (United States)

    Denis, Jean-François; Sader, Fadi; Gatien, Samuel; Villiard, Éric; Philip, Anie; Roy, Stéphane

    2016-10-01

    Axolotls are unique among vertebrates in their ability to regenerate tissues, such as limbs, tail and skin. The axolotl limb is the most studied regenerating structure. The process is well characterized morphologically; however, it is not well understood at the molecular level. We demonstrate that TGF-β1 is highly upregulated during regeneration and that TGF-β signaling is necessary for the regenerative process. We show that the basement membrane is not prematurely formed in animals treated with the TGF-β antagonist SB-431542. More importantly, Smad2 and Smad3 are differentially regulated post-translationally during the preparation phase of limb regeneration. Using specific antagonists for Smad2 and Smad3 we demonstrate that Smad2 is responsible for the action of TGF-β during regeneration, whereas Smad3 is not required. Smad2 target genes (Mmp2 and Mmp9) are inhibited in SB-431542-treated limbs, whereas non-canonical TGF-β targets (e.g. Mmp13) are unaffected. This is the first study to show that Smad2 and Smad3 are differentially regulated during regeneration and places Smad2 at the heart of TGF-β signaling supporting the regenerative process. © 2016. Published by The Company of Biologists Ltd.

  16. Myc and Fgf Are Required for Zebrafish Neuromast Hair Cell Regeneration.

    Science.gov (United States)

    Lee, Sang Goo; Huang, Mingqian; Obholzer, Nikolaus D; Sun, Shan; Li, Wenyan; Petrillo, Marco; Dai, Pu; Zhou, Yi; Cotanche, Douglas A; Megason, Sean G; Li, Huawei; Chen, Zheng-Yi

    2016-01-01

    Unlike mammals, the non-mammalian vertebrate inner ear can regenerate the sensory cells, hair cells, either spontaneously or through induction after hair cell loss, leading to hearing recovery. The mechanisms underlying the regeneration are poorly understood. By microarray analysis on a chick model, we show that chick hair cell regeneration involves the activation of proliferation genes and downregulation of differentiation genes. Both MYC and FGF are activated in chick hair cell regeneration. Using a zebrafish lateral line neuromast hair cell regeneration model, we show that the specific inhibition of Myc or Fgf suppresses hair cell regeneration, demonstrating that both pathways are essential to the process. Rapid upregulation of Myc and delayed Fgf activation during regeneration suggest a role of Myc in proliferation and Fgf in differentiation. The dorsal-ventral pattern of fgfr1a in the neuromasts overlaps with the distribution of hair cell precursors. By laser ablation, we show that the fgfr1a-positive supporting cells are likely the hair cell precursors that directly give rise to new hair cells; whereas the anterior-posterior fgfr1a-negative supporting cells have heightened proliferation capacity, likely to serve as more primitive progenitor cells to replenish lost precursors after hair cell loss. Thus fgfr1a is likely to mark compartmentalized supporting cell subtypes with different capacities in renewal proliferation and hair cell regeneration. Manipulation of c-MYC and FGF pathways could be explored for mammalian hair cell regeneration.

  17. Myc and Fgf Are Required for Zebrafish Neuromast Hair Cell Regeneration.

    Directory of Open Access Journals (Sweden)

    Sang Goo Lee

    Full Text Available Unlike mammals, the non-mammalian vertebrate inner ear can regenerate the sensory cells, hair cells, either spontaneously or through induction after hair cell loss, leading to hearing recovery. The mechanisms underlying the regeneration are poorly understood. By microarray analysis on a chick model, we show that chick hair cell regeneration involves the activation of proliferation genes and downregulation of differentiation genes. Both MYC and FGF are activated in chick hair cell regeneration. Using a zebrafish lateral line neuromast hair cell regeneration model, we show that the specific inhibition of Myc or Fgf suppresses hair cell regeneration, demonstrating that both pathways are essential to the process. Rapid upregulation of Myc and delayed Fgf activation during regeneration suggest a role of Myc in proliferation and Fgf in differentiation. The dorsal-ventral pattern of fgfr1a in the neuromasts overlaps with the distribution of hair cell precursors. By laser ablation, we show that the fgfr1a-positive supporting cells are likely the hair cell precursors that directly give rise to new hair cells; whereas the anterior-posterior fgfr1a-negative supporting cells have heightened proliferation capacity, likely to serve as more primitive progenitor cells to replenish lost precursors after hair cell loss. Thus fgfr1a is likely to mark compartmentalized supporting cell subtypes with different capacities in renewal proliferation and hair cell regeneration. Manipulation of c-MYC and FGF pathways could be explored for mammalian hair cell regeneration.

  18. Myc and Fgf Are Required for Zebrafish Neuromast Hair Cell Regeneration

    Science.gov (United States)

    Obholzer, Nikolaus D.; Sun, Shan; Li, Wenyan; Petrillo, Marco; Dai, Pu; Zhou, Yi; Cotanche, Douglas A.; Megason, Sean G.; Li, Huawei; Chen, Zheng-Yi

    2016-01-01

    Unlike mammals, the non-mammalian vertebrate inner ear can regenerate the sensory cells, hair cells, either spontaneously or through induction after hair cell loss, leading to hearing recovery. The mechanisms underlying the regeneration are poorly understood. By microarray analysis on a chick model, we show that chick hair cell regeneration involves the activation of proliferation genes and downregulation of differentiation genes. Both MYC and FGF are activated in chick hair cell regeneration. Using a zebrafish lateral line neuromast hair cell regeneration model, we show that the specific inhibition of Myc or Fgf suppresses hair cell regeneration, demonstrating that both pathways are essential to the process. Rapid upregulation of Myc and delayed Fgf activation during regeneration suggest a role of Myc in proliferation and Fgf in differentiation. The dorsal-ventral pattern of fgfr1a in the neuromasts overlaps with the distribution of hair cell precursors. By laser ablation, we show that the fgfr1a-positive supporting cells are likely the hair cell precursors that directly give rise to new hair cells; whereas the anterior-posterior fgfr1a-negative supporting cells have heightened proliferation capacity, likely to serve as more primitive progenitor cells to replenish lost precursors after hair cell loss. Thus fgfr1a is likely to mark compartmentalized supporting cell subtypes with different capacities in renewal proliferation and hair cell regeneration. Manipulation of c-MYC and FGF pathways could be explored for mammalian hair cell regeneration. PMID:27351484

  19. Renal failure

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    2008463 Protective effect of recombination rat augmenter of liver regeneration on kidney in acute renal failure rats. TANG Xiaopeng(唐晓鹏), et al. Dept Nephrol, 2nd Affili Hosp Chongqing Med Univ, Chongqing 400010.Chin J Nephrol 2008;24(6):417-421. Objective To investigate the protective effects of recombination rat augmenter of liver regeneration (rrALR) on tubular cell injury and renal dysfunction

  20. JNK controls the onset of mitosis in planarian stem cells and triggers apoptotic cell death required for regeneration and remodeling.

    Directory of Open Access Journals (Sweden)

    María Almuedo-Castillo

    2014-06-01

    Full Text Available Regeneration of lost tissues depends on the precise interpretation of molecular signals that control and coordinate the onset of proliferation, cellular differentiation and cell death. However, the nature of those molecular signals and the mechanisms that integrate the cellular responses remain largely unknown. The planarian flatworm is a unique model in which regeneration and tissue renewal can be comprehensively studied in vivo. The presence of a population of adult pluripotent stem cells combined with the ability to decode signaling after wounding enable planarians to regenerate a complete, correctly proportioned animal within a few days after any kind of amputation, and to adapt their size to nutritional changes without compromising functionality. Here, we demonstrate that the stress-activated c-jun-NH2-kinase (JNK links wound-induced apoptosis to the stem cell response during planarian regeneration. We show that JNK modulates the expression of wound-related genes, triggers apoptosis and attenuates the onset of mitosis in stem cells specifically after tissue loss. Furthermore, in pre-existing body regions, JNK activity is required to establish a positive balance between cell death and stem cell proliferation to enable tissue renewal, remodeling and the maintenance of proportionality. During homeostatic degrowth, JNK RNAi blocks apoptosis, resulting in impaired organ remodeling and rescaling. Our findings indicate that JNK-dependent apoptotic cell death is crucial to coordinate tissue renewal and remodeling required to regenerate and to maintain a correctly proportioned animal. Hence, JNK might act as a hub, translating wound signals into apoptotic cell death, controlled stem cell proliferation and differentiation, all of which are required to coordinate regeneration and tissue renewal.

  1. Embryonic origin of adult stem cells required for tissue homeostasis and regeneration

    Science.gov (United States)

    Davies, Erin L; Lei, Kai; Seidel, Christopher W; Kroesen, Amanda E; McKinney, Sean A; Guo, Longhua; Robb, Sofia MC; Ross, Eric J; Gotting, Kirsten; Alvarado, Alejandro Sánchez

    2017-01-01

    Planarian neoblasts are pluripotent, adult somatic stem cells and lineage-primed progenitors that are required for the production and maintenance of all differentiated cell types, including the germline. Neoblasts, originally defined as undifferentiated cells residing in the adult parenchyma, are frequently compared to embryonic stem cells yet their developmental origin remains obscure. We investigated the provenance of neoblasts during Schmidtea mediterranea embryogenesis, and report that neoblasts arise from an anarchic, cycling piwi-1+ population wholly responsible for production of all temporary and definitive organs during embryogenesis. Early embryonic piwi-1+ cells are molecularly and functionally distinct from neoblasts: they express unique cohorts of early embryo enriched transcripts and behave differently than neoblasts in cell transplantation assays. Neoblast lineages arise as organogenesis begins and are required for construction of all major organ systems during embryogenesis. These subpopulations are continuously generated during adulthood, where they act as agents of tissue homeostasis and regeneration. DOI: http://dx.doi.org/10.7554/eLife.21052.001 PMID:28072387

  2. Stem cell-dependent formation of a functional anterior regeneration pole in planarians requires Zic and Forkhead transcription factors.

    Science.gov (United States)

    Vogg, Matthias C; Owlarn, Suthira; Pérez Rico, Yuvia A; Xie, Jianlei; Suzuki, Yoko; Gentile, Luca; Wu, Wei; Bartscherer, Kerstin

    2014-06-15

    Planarians can regenerate their head within days. This process depends on the direction of adult stem cells to wound sites and the orchestration of their progenitors to commit to appropriate lineages and to arrange into patterned tissues. We identified a zinc finger transcription factor, Smed-ZicA, as a downstream target of Smed-FoxD, a Forkhead transcription factor required for head regeneration. Smed-zicA and Smed-FoxD are co-expressed with the Wnt inhibitor notum and the Activin inhibitor follistatin in a cluster of cells at the anterior-most tip of the regenerating head - the anterior regeneration pole - and in surrounding stem cell progeny. Depletion of Smed-zicA and Smed-FoxD by RNAi abolishes notum and follistatin expression at the pole and inhibits head formation downstream of initial polarity decisions. We suggest a model in which ZicA and FoxD transcription factors synergize to control the formation of Notum- and Follistatin-producing anterior pole cells. Pole formation might constitute an early step in regeneration, resulting in a signaling center that orchestrates cellular events in the growing tissue.

  3. Smed-Evi/Wntless is required for beta-catenin-dependent and -independent processes during planarian regeneration.

    Science.gov (United States)

    Adell, Teresa; Salò, Emili; Boutros, Michael; Bartscherer, Kerstin

    2009-03-01

    Planarians can regenerate a whole animal from only a small piece of their body, and have become an important model for stem cell biology. To identify regenerative processes dependent on Wnt growth factors in the planarian Schmidtea mediterranea (Smed), we analyzed RNAi phenotypes of Evi, a transmembrane protein specifically required for the secretion of Wnt ligands. We show that, during regeneration, Smed-evi loss-of-function prevents posterior identity, leading to two-headed planarians that resemble Smed-beta-catenin1 RNAi animals. In addition, we observe regeneration defects of the nervous system that are not found after Smed-beta-catenin1 RNAi. By systematic knockdown of all putative Smed Wnts in regenerating planarians, we identify Smed-WntP-1 and Smed-Wnt11-2 as the putative posterior organizers, and demonstrate that Smed-Wnt5 is a regulator of neuronal organization and growth. Thus, our study provides evidence that planarian Wnts are major regulators of regeneration, and that they signal through beta-catenin-dependent and -independent pathways.

  4. A forkhead transcription factor is wound-induced at the planarian midline and required for anterior pole regeneration.

    Directory of Open Access Journals (Sweden)

    M Lucila Scimone

    2014-01-01

    Full Text Available Planarian regeneration requires positional information to specify the identity of tissues to be replaced as well as pluripotent neoblasts capable of differentiating into new cell types. We found that wounding elicits rapid expression of a gene encoding a Forkhead-family transcription factor, FoxD. Wound-induced FoxD expression is specific to the ventral midline, is regulated by Hedgehog signaling, and is neoblast-independent. FoxD is subsequently expressed within a medial subpopulation of neoblasts at wounds involving head regeneration. Ultimately, FoxD is co-expressed with multiple anterior markers at the anterior pole. Inhibition of FoxD with RNA interference (RNAi results in the failure to specify neoblasts expressing anterior markers (notum and prep and in anterior pole formation defects. FoxD(RNAi animals fail to regenerate a new midline and to properly pattern the anterior blastema, consistent with a role for the anterior pole in organizing pattern of the regenerating head. Our results suggest that wound signaling activates a forkhead transcription factor at the midline and, if the head is absent, FoxD promotes specification of neoblasts at the prior midline for anterior pole regeneration.

  5. Akt-mediated foxo1 inhibition is required for liver regeneration.

    Science.gov (United States)

    Pauta, Montse; Rotllan, Noemi; Fernández-Hernando, Ana; Langhi, Cedric; Ribera, Jordi; Lu, Mingjian; Boix, Loreto; Bruix, Jordi; Jimenez, Wladimiro; Suárez, Yajaira; Ford, David A; Baldán, Angel; Birnbaum, Morris J; Morales-Ruiz, Manuel; Fernández-Hernando, Carlos

    2016-05-01

    Understanding the hepatic regenerative process has clinical interest as the effectiveness of many treatments for chronic liver diseases is conditioned by efficient liver regeneration. Experimental evidence points to the need for a temporal coordination between cytokines, growth factors, and metabolic signaling pathways to enable successful liver regeneration. One intracellular mediator that acts as a signal integration node for these processes is the serine-threonine kinase Akt/protein kinase B (Akt). To investigate the contribution of Akt during hepatic regeneration, we performed partial hepatectomy in mice lacking Akt1, Akt2, or both isoforms. We found that absence of Akt1 or Akt2 does not influence liver regeneration after partial hepatectomy. However, hepatic-specific Akt1 and Akt2 null mice show impaired liver regeneration and increased mortality. The major abnormal cellular events observed in total Akt-deficient livers were a marked reduction in cell proliferation, cell hypertrophy, glycogenesis, and lipid droplet formation. Most importantly, liver-specific deletion of FoxO1, a transcription factor regulated by Akt, rescued the hepatic regenerative capability in Akt1-deficient and Akt2-deficient mice and normalized the cellular events associated with liver regeneration. The Akt-FoxO1 signaling pathway plays an essential role during liver regeneration. © 2015 by the American Association for the Study of Liver Diseases.

  6. TWEAK/Fn14 Signaling Is Required for Liver Regeneration after Partial Hepatectomy in Mice

    OpenAIRE

    Gamze Karaca; Marzena Swiderska-Syn; Guanhua Xie; Wing-Kin Syn; Leandi Krüger; Mariana Verdelho Machado; Katherine Garman; Choi, Steve S.; Michelotti, Gregory A.; Burkly, Linda C.; Begoña Ochoa; Anna Mae Diehl

    2014-01-01

    Background & Aims: Pro-inflammatory cytokines are important for liver regeneration after partial hepatectomy (PH). Expression of Fibroblast growth factor-inducible 14 (Fn14), the receptor for TNF-like weak inducer of apoptosis (TWEAK), is induced rapidly after PH and remains elevated throughout the period of peak hepatocyte replication. The role of Fn14 in post-PH liver regeneration is uncertain because Fn14 is expressed by liver progenitors and TWEAK-Fn14 interactions stimulate progenitor gr...

  7. Requirement of MEF2A, C, and D for skeletal muscle regeneration

    Science.gov (United States)

    Liu, Ning; Nelson, Benjamin R.; Bezprozvannaya, Svetlana; Shelton, John M.; Richardson, James A.; Bassel-Duby, Rhonda; Olson, Eric N.

    2014-01-01

    Regeneration of adult skeletal muscle following injury occurs through the activation of satellite cells, an injury-sensitive muscle stem cell population that proliferates, differentiates, and fuses with injured myofibers. Members of the myocyte enhancer factor 2 (MEF2) family of transcription factors play essential roles in muscle differentiation during embryogenesis, but their potential contributions to adult muscle regeneration have not been systematically explored. To investigate the potential involvement of MEF2 factors in muscle regeneration, we conditionally deleted the Mef2a, c, and d genes, singly and in combination, within satellite cells in mice, using tamoxifen-inducible Cre recombinase under control of the satellite cell-specific Pax7 promoter. We show that deletion of individual Mef2 genes has no effect on muscle regeneration in response to cardiotoxin injury. However, combined deletion of the Mef2a, c, and d genes results in a blockade to regeneration. Satellite cell-derived myoblasts lacking MEF2A, C, and D proliferate normally in culture, but cannot differentiate. The absence of MEF2A, C, and D in satellite cells is associated with aberrant expression of a broad collection of known and unique protein-coding and long noncoding RNA genes. These findings reveal essential and redundant roles of MEF2A, C, and D in satellite cell differentiation and identify a MEF2-dependent transcriptome associated with skeletal muscle regeneration. PMID:24591619

  8. NKCC1 Activation Is Required for Myelinated Sensory Neurons Regeneration through JNK-Dependent Pathway.

    Science.gov (United States)

    Mòdol, Laura; Santos, Daniel; Cobianchi, Stefano; González-Pérez, Francisco; López-Alvarez, Víctor; Navarro, Xavier

    2015-05-13

    After peripheral nerve injury, axons are able to regenerate, although specific sensory reinnervation and functional recovery are usually worse for large myelinated than for small sensory axons. The mechanisms that mediate the regeneration of different sensory neuron subpopulations are poorly known. The Na(+)-K(+)-Cl(-) cotransporter 1 (NKCC1) is particularly relevant in setting the intracellular chloride concentration. After axotomy, increased NKCC1 phosphorylation has been reported to be important for neurite outgrowth of sensory neurons; however, the mechanisms underlying its effects are still unknown. In the present study we used in vitro and in vivo models to assess the differential effects of blocking NKCC1 activity on the regeneration of different types of dorsal root ganglia (DRGs) neurons after sciatic nerve injury in the rat. We observed that blocking NKCC1 activity by bumetanide administration induces a selective effect on neurite outgrowth and regeneration of myelinated fibers without affecting unmyelinated DRG neurons. To further study the mechanism underlying NKCC1 effects, we also assessed the changes in mitogen-activated protein kinase (MAPK) signaling under NKCC1 modulation. The inhibition of NKCC1 activity in vitro and in vivo modified pJNK1/2/3 expression in DRG neurons. Together, our study identifies a mechanism selectively contributing to myelinated axon regeneration, and point out the role of Cl(-) modulation in DRG neuron regeneration and in the activation of MAPKs, particularly those belonging to the JNK family. Copyright © 2015 the authors 0270-6474/15/357414-14$15.00/0.

  9. Runx1 Transcription Factor Is Required for Myoblasts Proliferation during Muscle Regeneration.

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    Kfir Baruch Umansky

    2015-08-01

    Full Text Available Following myonecrosis, muscle satellite cells proliferate, differentiate and fuse, creating new myofibers. The Runx1 transcription factor is not expressed in naïve developing muscle or in adult muscle tissue. However, it is highly expressed in muscles exposed to myopathic damage yet, the role of Runx1 in muscle regeneration is completely unknown. Our study of Runx1 function in the muscle's response to myonecrosis reveals that this transcription factor is activated and cooperates with the MyoD and AP-1/c-Jun transcription factors to drive the transcription program of muscle regeneration. Mice lacking dystrophin and muscle Runx1 (mdx-/Runx1f/f, exhibit impaired muscle regeneration leading to age-dependent muscle waste, gradual decrease in motor capabilities and a shortened lifespan. Runx1-deficient primary myoblasts are arrested at cell cycle G1 and consequently differentiate. Such premature differentiation disrupts the myoblasts' normal proliferation/differentiation balance, reduces the number and size of regenerating myofibers and impairs muscle regeneration. Our combined Runx1-dependent gene expression, ChIP-seq, ATAC-seq and histone H3K4me1/H3K27ac modification analyses revealed a subset of Runx1-regulated genes that are co-occupied by MyoD and c-Jun in mdx-/Runx1f/f muscle. The data provide unique insights into the transcriptional program driving muscle regeneration and implicate Runx1 as an important participant in the pathology of muscle wasting diseases.

  10. β-catenin is selectively required for the expansion and regeneration of mature pancreatic acinar cells in mice

    Directory of Open Access Journals (Sweden)

    Matthew D. Keefe

    2012-07-01

    The size of the pancreas is determined by intrinsic factors, such as the number of progenitor cells, and by extrinsic signals that control the fate and proliferation of those progenitors. Both the exocrine and endocrine compartments of the pancreas undergo dramatic expansion after birth and are capable of at least partial regeneration following injury. Whether the expansion of these lineages relies on similar mechanisms is unknown. Although we have shown that the Wnt signaling component β-catenin is selectively required in mouse embryos for the generation of exocrine acinar cells, this protein has been ascribed various functions in the postnatal pancreas, including proliferation and regeneration of islet as well as acinar cells. To address whether β-catenin remains important for the maintenance and expansion of mature acinar cells, we have established a system to follow the behavior and fate of β-catenin-deficient cells during postnatal growth and regeneration in mice. We find that β-catenin is continuously required for the establishment and maintenance of acinar cell mass, extending from embryonic specification through juvenile and adult self-renewal and regeneration. This requirement is not shared with islet cells, which proliferate and function normally in the absence of β-catenin. These results make distinct predictions for the relative role of Wnt–β-catenin signaling in the etiology of human endocrine and exocrine disease. We suggest that loss of Wnt–β-catenin activity is unlikely to drive islet dysfunction, as occurs in type 2 diabetes, but that β-catenin is likely to promote human acinar cell proliferation following injury, and might therefore contribute to the resolution of acute or chronic pancreatitis.

  11. Planarian homologs of netrin and netrin receptor are required for proper regeneration of the central nervous system and the maintenance of nervous system architecture.

    Science.gov (United States)

    Cebrià, Francesc; Newmark, Phillip A

    2005-08-01

    Conserved axon guidance mechanisms are essential for proper wiring of the nervous system during embryogenesis; however, the functions of these cues in adults and during regeneration remain poorly understood. Because freshwater planarians can regenerate a functional central nervous system (CNS) from almost any portion of their body, they are useful models in which to study the roles of guidance cues during neural regeneration. Here, we characterize two netrin homologs and one netrin receptor family member from Schmidtea mediterranea. RNAi analyses indicate that Smed-netR (netrin receptor) and Smed-netrin2 are required for proper CNS regeneration and that Smed-netR may mediate the response to Smed-netrin2. Remarkably, Smed-netR and Smed-netrin2 are also required in intact planarians to maintain the proper patterning of the CNS. These results suggest a crucial role for guidance cues, not only in CNS regeneration but also in maintenance of neural architecture.

  12. Phoenix is required for mechanosensory hair cell regeneration in the zebrafish lateral line.

    Science.gov (United States)

    Behra, Martine; Bradsher, John; Sougrat, Rachid; Gallardo, Viviana; Allende, Miguel L; Burgess, Shawn M

    2009-04-01

    In humans, the absence or irreversible loss of hair cells, the sensory mechanoreceptors in the cochlea, accounts for a large majority of acquired and congenital hearing disorders. In the auditory and vestibular neuroepithelia of the inner ear, hair cells are accompanied by another cell type called supporting cells. This second cell population has been described as having stem cell-like properties, allowing efficient hair cell replacement during embryonic and larval/fetal development of all vertebrates. However, mammals lose their regenerative capacity in most inner ear neuroepithelia in postnatal life. Remarkably, reptiles, birds, amphibians, and fish are different in that they can regenerate hair cells throughout their lifespan. The lateral line in amphibians and in fish is an additional sensory organ, which is used to detect water movements and is comprised of neuroepithelial patches, called neuromasts. These are similar in ultra-structure to the inner ear's neuroepithelia and they share the expression of various molecular markers. We examined the regeneration process in hair cells of the lateral line of zebrafish larvae carrying a retroviral integration in a previously uncharacterized gene, phoenix (pho). Phoenix mutant larvae develop normally and display a morphologically intact lateral line. However, after ablation of hair cells with copper or neomycin, their regeneration in pho mutants is severely impaired. We show that proliferation in the supporting cells is strongly decreased after damage to hair cells and correlates with the reduction of newly formed hair cells in the regenerating phoenix mutant neuromasts. The retroviral integration linked to the phenotype is in a novel gene with no known homologs showing high expression in neuromast supporting cells. Whereas its role during early development of the lateral line remains to be addressed, in later larval stages phoenix defines a new class of proteins implicated in hair cell regeneration.

  13. Phoenix is required for mechanosensory hair cell regeneration in the zebrafish lateral line.

    Directory of Open Access Journals (Sweden)

    Martine Behra

    2009-04-01

    Full Text Available In humans, the absence or irreversible loss of hair cells, the sensory mechanoreceptors in the cochlea, accounts for a large majority of acquired and congenital hearing disorders. In the auditory and vestibular neuroepithelia of the inner ear, hair cells are accompanied by another cell type called supporting cells. This second cell population has been described as having stem cell-like properties, allowing efficient hair cell replacement during embryonic and larval/fetal development of all vertebrates. However, mammals lose their regenerative capacity in most inner ear neuroepithelia in postnatal life. Remarkably, reptiles, birds, amphibians, and fish are different in that they can regenerate hair cells throughout their lifespan. The lateral line in amphibians and in fish is an additional sensory organ, which is used to detect water movements and is comprised of neuroepithelial patches, called neuromasts. These are similar in ultra-structure to the inner ear's neuroepithelia and they share the expression of various molecular markers. We examined the regeneration process in hair cells of the lateral line of zebrafish larvae carrying a retroviral integration in a previously uncharacterized gene, phoenix (pho. Phoenix mutant larvae develop normally and display a morphologically intact lateral line. However, after ablation of hair cells with copper or neomycin, their regeneration in pho mutants is severely impaired. We show that proliferation in the supporting cells is strongly decreased after damage to hair cells and correlates with the reduction of newly formed hair cells in the regenerating phoenix mutant neuromasts. The retroviral integration linked to the phenotype is in a novel gene with no known homologs showing high expression in neuromast supporting cells. Whereas its role during early development of the lateral line remains to be addressed, in later larval stages phoenix defines a new class of proteins implicated in hair cell regeneration.

  14. ROS-Induced JNK and p38 Signaling Is Required for Unpaired Cytokine Activation during Drosophila Regeneration.

    Directory of Open Access Journals (Sweden)

    Paula Santabárbara-Ruiz

    2015-10-01

    Full Text Available Upon apoptotic stimuli, epithelial cells compensate the gaps left by dead cells by activating proliferation. This has led to the proposal that dying cells signal to surrounding living cells to maintain homeostasis. Although the nature of these signals is not clear, reactive oxygen species (ROS could act as a signaling mechanism as they can trigger pro-inflammatory responses to protect epithelia from environmental insults. Whether ROS emerge from dead cells and what is the genetic response triggered by ROS is pivotal to understand regeneration of Drosophila imaginal discs. We genetically induced cell death in wing imaginal discs, monitored the production of ROS and analyzed the signals required for repair. We found that cell death generates a burst of ROS that propagate to the nearby surviving cells. Propagated ROS activate p38 and induce tolerable levels of JNK. The activation of JNK and p38 results in the expression of the cytokines Unpaired (Upd, which triggers the JAK/STAT signaling pathway required for regeneration. Our findings demonstrate that this ROS/JNK/p38/Upd stress responsive module restores tissue homeostasis. This module is not only activated after cell death induction but also after physical damage and reveals one of the earliest responses for imaginal disc regeneration.

  15. ROS-Induced JNK and p38 Signaling Is Required for Unpaired Cytokine Activation during Drosophila Regeneration.

    Science.gov (United States)

    Santabárbara-Ruiz, Paula; López-Santillán, Mireya; Martínez-Rodríguez, Irene; Binagui-Casas, Anahí; Pérez, Lídia; Milán, Marco; Corominas, Montserrat; Serras, Florenci

    2015-10-01

    Upon apoptotic stimuli, epithelial cells compensate the gaps left by dead cells by activating proliferation. This has led to the proposal that dying cells signal to surrounding living cells to maintain homeostasis. Although the nature of these signals is not clear, reactive oxygen species (ROS) could act as a signaling mechanism as they can trigger pro-inflammatory responses to protect epithelia from environmental insults. Whether ROS emerge from dead cells and what is the genetic response triggered by ROS is pivotal to understand regeneration of Drosophila imaginal discs. We genetically induced cell death in wing imaginal discs, monitored the production of ROS and analyzed the signals required for repair. We found that cell death generates a burst of ROS that propagate to the nearby surviving cells. Propagated ROS activate p38 and induce tolerable levels of JNK. The activation of JNK and p38 results in the expression of the cytokines Unpaired (Upd), which triggers the JAK/STAT signaling pathway required for regeneration. Our findings demonstrate that this ROS/JNK/p38/Upd stress responsive module restores tissue homeostasis. This module is not only activated after cell death induction but also after physical damage and reveals one of the earliest responses for imaginal disc regeneration.

  16. DNMT1 is a Required Genomic Regulator for Murine Liver Histogenesis and Regeneration

    DEFF Research Database (Denmark)

    Kaji, Kosuke; Factor, Valentina M; Andersen, Jesper B

    2016-01-01

    conditional knockout mice (Dnmt1(Δalb) ) by crossing Dnmt1(fl/fl) with Albumin-Cre (Alb-Cre) transgenic mice. Serum, liver tissues and primary hepatocytes were collected from 1-20 week old mice. The Dnmt1(Δalb) phenotype was assessed by histology, confocal and electron microscopy, biochemistry as well...... hepatocytes caused global hypomethylation, enhanced DNA damage response and initiated a senescence state causing a progressive inability to maintain tissue homeostasis and proliferate in response to injury. The liver regenerated via activation and repopulation from progenitors due to lineage...... hepatocytes did not affect liver homeostasis. CONCLUSION: These results establish the indispensable role of DNMT1-mediated epigenetic regulation in postnatal liver growth and regeneration. The Dnmt1(Δalb) mice provide a unique experimental model to study the role of senescence and contribution of progenitor...

  17. Mitochondrial DNA Unwinding Enzyme Required for Liver Regeneration | Center for Cancer Research

    Science.gov (United States)

    The liver has an exceptional capacity to proliferate. This ability allows the liver to regenerate its mass after partial surgical removal or injury and is the key to successful partial liver transplants. Liver cells, called hepatocytes, are packed with mitochondria, and regulating mitochondrial DNA (mtDNA) copy number is crucial to mitochondrial function, including energy production, during proliferation. Yves Pommier, M.D., Ph.D., of CCR’s Developmental Therapeutics Branch, and his colleagues recently showed that the vertebrate mitochondrial topoisomerase, Top1mt, was critical in maintaining mitochondrial function in the heart after doxorubicin-induced damage. The group wondered whether Top1mt might play a similar role in liver regeneration.

  18. A new model to predict acute kidney injury requiring renal replacement therapy after cardiac surgery

    Science.gov (United States)

    Pannu, Neesh; Graham, Michelle; Klarenbach, Scott; Meyer, Steven; Kieser, Teresa; Hemmelgarn, Brenda; Ye, Feng; James, Matthew

    2016-01-01

    Background: Acute kidney injury after cardiac surgery is associated with adverse in-hospital and long-term outcomes. Novel risk factors for acute kidney injury have been identified, but it is unknown whether their incorporation into risk models substantially improves prediction of postoperative acute kidney injury requiring renal replacement therapy. Methods: We developed and validated a risk prediction model for acute kidney injury requiring renal replacement therapy within 14 days after cardiac surgery. We used demographic, and preoperative clinical and laboratory data from 2 independent cohorts of adults who underwent cardiac surgery (excluding transplantation) between Jan. 1, 2004, and Mar. 31, 2009. We developed the risk prediction model using multivariable logistic regression and compared it with existing models based on the C statistic, Hosmer–Lemeshow goodness-of-fit test and Net Reclassification Improvement index. Results: We identified 8 independent predictors of acute kidney injury requiring renal replacement therapy in the derivation model (adjusted odds ratio, 95% confidence interval [CI]): congestive heart failure (3.03, 2.00–4.58), Canadian Cardiovascular Society angina class III or higher (1.66, 1.15–2.40), diabetes mellitus (1.61, 1.12–2.31), baseline estimated glomerular filtration rate (0.96, 0.95–0.97), increasing hemoglobin concentration (0.85, 0.77–0.93), proteinuria (1.65, 1.07–2.54), coronary artery bypass graft (CABG) plus valve surgery (v. CABG only, 1.25, 0.64–2.43), other cardiac procedure (v. CABG only, 3.11, 2.12–4.58) and emergent status for surgery booking (4.63, 2.61–8.21). The 8-variable risk prediction model had excellent performance characteristics in the validation cohort (C statistic 0.83, 95% CI 0.79–0.86). The net reclassification improvement with the prediction model was 13.9% (p < 0.001) compared with the best existing risk prediction model (Cleveland Clinic Score). Interpretation: We have developed

  19. Specific NuRD components are required for fin regeneration in zebrafish

    OpenAIRE

    Pfefferli, Catherine; Müller, Fritz; Jaźwińska, Anna; Wicky, Chantal

    2014-01-01

    Background: epimorphic regeneration of a missing appendage in fish and urodele amphibians involves the creation of a blastema, a heterogeneous pool of progenitor cells underneath the wound epidermis. Current evidence indicates that the blastema arises by dedifferentiation of stump tissues in the vicinity of the amputation. In response to tissue loss, silenced developmental programs are reactivated to form a near-perfect copy of the missing body part. However, the importance of chromatin regul...

  20. TWEAK/Fn14 signaling is required for liver regeneration after partial hepatectomy in mice.

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    Gamze Karaca

    Full Text Available BACKGROUND & AIMS: Pro-inflammatory cytokines are important for liver regeneration after partial hepatectomy (PH. Expression of Fibroblast growth factor-inducible 14 (Fn14, the receptor for TNF-like weak inducer of apoptosis (TWEAK, is induced rapidly after PH and remains elevated throughout the period of peak hepatocyte replication. The role of Fn14 in post-PH liver regeneration is uncertain because Fn14 is expressed by liver progenitors and TWEAK-Fn14 interactions stimulate progenitor growth, but replication of mature hepatocytes is thought to drive liver regeneration after PH. METHODS: To clarify the role of TWEAK-Fn14 after PH, we compared post-PH regenerative responses in wild type (WT mice, Fn14 knockout (KO mice, TWEAK KO mice, and WT mice treated with anti-TWEAK antibodies. RESULTS: In WT mice, rare Fn14(+ cells localized with other progenitor markers in peri-portal areas before PH. PH rapidly increased proliferation of Fn14(+ cells; hepatocytic cells that expressed Fn14 and other progenitor markers, such as Lgr5, progressively accumulated from 12-8 h post-PH and then declined to baseline by 96 h. When TWEAK/Fn14 signaling was disrupted, progenitor accumulation, induction of pro-regenerative cytokines, hepatocyte and cholangiocyte proliferation, and over-all survival were inhibited, while post-PH liver damage and bilirubin levels were increased. TWEAK stimulated proliferation and increased Lgr5 expression in cultured liver progenitors, but had no effect on either parameter in cultured primary hepatocytes. CONCLUSIONS: TWEAK-FN14 signaling is necessary for the healthy adult liver to regenerate normally after acute partial hepatectomy.

  1. Foxd1-dependent signals control cellularity in the renal capsule, a structure required for normal renal development.

    Science.gov (United States)

    Levinson, Randy S; Batourina, Ekatherina; Choi, Christopher; Vorontchikhina, Marina; Kitajewski, Jan; Mendelsohn, Cathy L

    2005-02-01

    Development of the metanephric kidney involves the establishment of discrete zones of induction and differentiation that are crucial to the future radial patterning of the organ. Genetic deletion of the forkhead transcription factor, Foxd1, results in striking renal abnormalities, including the loss of these discrete zones and pelvic fused kidneys. We have investigated the molecular and cellular basis of the kidney phenotypes displayed by Foxd1-null embryos and report here that they are likely to be caused by a failure in the correct formation of the renal capsule. Unlike the single layer of Foxd1-positive stroma that comprises the normal renal capsule, the mutant capsule contains heterogeneous layers of cells, including Bmp4-expressing cells, which induce ectopic phospho-Smad1 signaling in nephron progenitors. This missignaling disrupts their early patterning, which, in turn, causes mispatterning of the ureteric tree, while delaying and disorganizing nephrogenesis. In addition, the defects in capsule formation prevent the kidneys from detaching from the body wall, thus explaining their fusion and pelvic location. For the first time, functions have been ascribed to the renal capsule that include delineation of the organ and acting as a barrier to inappropriate exogenous signals, while providing a source of endogenous signals that are crucial to the establishment of the correct zones of induction and differentiation.

  2. Prognostic indicators and patterns of renal recovery in patients requiring hemodialysis for acute kidney injury

    Directory of Open Access Journals (Sweden)

    Vaddadi Suresh, Usha Bhargavi E, N.S.R.C Guptha, Vinod L, Vijay Kumar P, Ravinder P

    2014-03-01

    Full Text Available Background: The outcome of patients with acute kidney injury (AKI is highly variable. Patients who receive renal replacement therapy (RRT for similar diseases may recover differently. The factors that operate in each patient may alter the prognosis and outcome. Aims: Our study aims at identification of prognostic factors influencing recovery in patients who required hemodialysis for AKI. Material and Methods: Patients admitted in different ICUs with AKI who underwent hemodialysis in a tertiary care hospital over a three year period were included in the study. Time from day one of disease to first dialysis, hematological and biochemical parameters were noted. Patients were grouped based on the time taken for recovery of renal function following hemodialysis into group A (2 weeks. Studied parameters have been statistically analyzed to find any significant association with recovery time. Results: Out of 63 patients, 9 progressed to chronic kidney disease. In the remaining 54, Group A comprised 31 and group B 23. Out of all the factors studied, serum creatinine (7.0±1.3 vs 8.4±3.8; P=0.018, S. bicarbonate (21.7±2.8 vs 19.7±3.8; P=0.03, pH at admission (7.25±0.13 vs 7.1±0.19; P=0.048; number of hemodialysis sessions (3.5 ±1.5 vs 5±2.4; P=0.016 and time lag from day one of disease to first hemodialysis (8.6 ± 3.6 vs 11.5±5.9; P=0.007 showed significant association with recovery time. Conclusion: Recovery following AKI is influenced by factors liked delayed presentation, late initiation of hemodialysis, low pH and low bicarbonate which can predict delayed renal recovery following hemodialysis.

  3. [Disseminated intravascular coagulation and acute kidney injury requiring renal replacement therapy after diagnostic amniocentesis].

    Science.gov (United States)

    Ratković, Marina; Bašić-Jukić, Nikolina; Gledović, Branka; Radunović, Danilo

    2014-04-01

    Disseminated intravascular coagulation (DIC) is a very rare complication of amniocentesis. We present a case of a 33-year-old patient who developed DIC with acute respiratory distress syndrome and acute kidney injury after diagnostic amniocentesis. The patient required replacement of renal function for 59 days with continuous venovenous hemodiafiltration and later with hemodialysis. She was treated with heparin, fresh frozen plasma, platelets and cryoprecipitate. Her condition was further complicated with the development of intracranial hematoma. After 67 days of hospitalization, she was discharged from the hospital with serum creatinine 337 μmol/L. Three years later, her serum creatinine was 102 μmol/L, and she is currently in the 7th month of pregnancy.

  4. Transiently Active Wnt/β-Catenin Signaling Is Not Required but Must Be Silenced for Stem Cell Function during Muscle Regeneration

    Directory of Open Access Journals (Sweden)

    Malea M. Murphy

    2014-09-01

    Full Text Available Adult muscle’s exceptional capacity for regeneration is mediated by muscle stem cells, termed satellite cells. As with many stem cells, Wnt/β-catenin signaling has been proposed to be critical in satellite cells during regeneration. Using new genetic reagents, we explicitly test in vivo whether Wnt/β-catenin signaling is necessary and sufficient within satellite cells and their derivatives for regeneration. We find that signaling is transiently active in transit-amplifying myoblasts, but is not required for regeneration or satellite cell self-renewal. Instead, downregulation of transiently activated β-catenin is important to limit the regenerative response, as continuous regeneration is deleterious. Wnt/β-catenin activation in adult satellite cells may simply be a vestige of their developmental lineage, in which β-catenin signaling is critical for fetal myogenesis. In the adult, surprisingly, we show that it is not activation but rather silencing of Wnt/β-catenin signaling that is important for muscle regeneration.

  5. EGFR signaling is required for re-establishing the proximodistal axis during distal leg regeneration in the cricket Gryllus bimaculatus nymph.

    Science.gov (United States)

    Nakamura, Taro; Mito, Taro; Miyawaki, Katsuyuki; Ohuchi, Hideyo; Noji, Sumihare

    2008-07-01

    Nymphs of hemimetabolous insects, such as cockroaches and crickets, possess functional legs with a remarkable capacity for epimorphic regeneration. In this study, we have focused on the role of epidermal growth factor receptor (EGFR) signaling in regeneration of a nymphal leg in the cricket Gryllus bimaculatus. We performed loss-of-function analyses with a Gryllus Egfr homolog (Gb'Egfr) and nymphal RNA interference (RNAi). After injection of double-stranded RNA for Gb'Egfr in the body cavity of the third instar cricket nymph, amputation of the leg at the distal tibia resulted in defects of normal distal regeneration. The regenerated leg lacked the distal tarsus and pretarsus. This result indicates that EGFR signaling is required for distal leg patterning in regeneration during the nymphal stage of the cricket. Furthermore, we demonstrated that EGFR signaling acts downstream of the canonical Wnt/Wg signaling and regulates appendage proximodistal (PD) patterning genes aristaless and dachshund during regeneration. Our results suggest that EGFR signaling influences positional information along the PD axis in distal leg patterning of insects, regardless of the leg formation mode.

  6. Transcription factors lhx1/5-1 and pitx are required for the maintenance and regeneration of serotonergic neurons in planarians.

    Science.gov (United States)

    Currie, Ko W; Pearson, Bret J

    2013-09-01

    In contrast to most adult organisms, freshwater planarians can regenerate any injured body part, including their entire nervous system. This allows for the analysis of genes required for both the maintenance and regeneration of specific neural subtypes. In addition, the loss of specific neural subtypes may uncover previously unknown behavioral roles for that neural population in the context of the adult animal. Here we show that two homeodomain transcription factor homologs, Smed-lhx1/5-1 and Smed-pitx, are required for the maintenance and regeneration of serotonergic neurons in planarians. When either lhx1/5-1 or pitx was knocked down by RNA interference, the expression of multiple canonical markers for serotonergic neurons was lost. Surprisingly, the loss of serotonergic function uncovered a role for these neurons in the coordination of motile cilia on the ventral epidermis of planarians that are required for their nonmuscular gliding locomotion. Finally, we show that in addition to its requirement in serotonergic neurons, Smed-pitx is required for proper midline patterning during regeneration, when it is required for the expression of the midline-organizing molecules Smed-slit in the anterior and Smed-wnt1 in the posterior.

  7. Laboratory prediction of the requirement for renal replacement in acute falciparum malaria

    NARCIS (Netherlands)

    Hanson, J.; Hasan, M.M.U.; Royakkers, A.A.; Alam, S.; Charunwatthana, P.; Maude, R.J.; Douthwaite, S.T.; Yunus, E.B.; Mantha, M.L.; Schultz, M.J.; Faiz, M.A.; White, N.J.; Day, N.P.; Dondorp, A.M.

    2011-01-01

    Acute renal failure is a common complication of severe malaria in adults, and without renal replacement therapy (RRT), it carries a poor prognosis. Even when RRT is available, delaying its initiation may increase mortality. Earlier identification of patients who will need RRT may improve outcomes. P

  8. Supporting cell division is not required for regeneration of auditory hair cells after ototoxic injury in vitro.

    Science.gov (United States)

    Shang, Jialin; Cafaro, Jon; Nehmer, Rachel; Stone, Jennifer

    2010-06-01

    In chickens, nonsensory supporting cells divide and regenerate auditory hair cells after injury. Anatomical evidence suggests that supporting cells can also transdifferentiate into hair cells without dividing. In this study, we characterized an organ culture model to study auditory hair cell regeneration, and we used these cultures to test if direct transdifferentiation alone can lead to significant hair cell regeneration. Control cultures (organs from posthatch chickens maintained without streptomycin) showed complete hair cell loss in the proximal (high-frequency) region by 5 days. In contrast, a 2-day treatment with streptomycin induced loss of hair cells from all regions by 3 days. Hair cell regeneration proceeded in culture, with the time course of supporting cell division and hair cell differentiation generally resembling in vivo patterns. The degree of supporting cell division depended upon the presence of streptomycin, the epithelial region, the type of culture media, and serum concentration. On average, 87% of the regenerated hair cells lacked the cell division marker BrdU despite its continuous presence, suggesting that most hair cells were regenerated via direct transdifferentiation. Addition of the DNA polymerase inhibitor aphidicolin to culture media prevented supporting cell division, but numerous hair cells were regenerated nonetheless. These hair cells showed signs of functional maturation, including stereociliary bundles and rapid uptake of FM1-43. These observations demonstrate that direct transdifferentiation is a significant mechanism of hair cell regeneration in the chicken auditory after streptomycin damage in vitro.

  9. Focal adhesion kinase is required for intestinal regeneration and tumorigenesis downstream of Wnt/c-Myc signaling

    NARCIS (Netherlands)

    Ashton, G.H.; Morton, J.P.; Myant, K.; Phesse, T.J.; Ridgway, R.A.; Marsh, V.; Wilkins, J.A.; Athineos, D.; Muncan, V.; Kemp, R.; Neufeld, K.; Clevers, H.; Brunton, V.; Winton, D.J.; Wang, X.; Sears, R.; Clarke, A.R.; Frame, M.C.; Sansom, O.J.

    2010-01-01

    The intestinal epithelium has a remarkable capacity to regenerate after injury and DNA damage. Here, we show that the integrin effector protein Focal Adhesion Kinase (FAK) is dispensable for normal intestinal homeostasis and DNA damage signaling, but is essential for intestinal regeneration followin

  10. Renal failure (chronic)

    OpenAIRE

    Clase, Catherine

    2011-01-01

    Chronic renal failure is characterised by a gradual and sustained decline in renal clearance or glomerular filtration rate (GFR). Continued progression of renal failure will lead to renal function too low to sustain healthy life. In developed countries, such people will be offered renal replacement therapy in the form of dialysis or renal transplantation. Requirement for dialysis or transplantation is termed end-stage renal disease (ESRD).Diabetes, glomerulonephritis, hypertension, pyelone...

  11. Periodontal regeneration.

    Science.gov (United States)

    Ivanovski, S

    2009-09-01

    The ultimate goal of periodontal therapy is the regeneration of the tissues destroyed as a result of periodontal disease. Currently, two clinical techniques, based on the principles of "guided tissue regeneration" (GTR) or utilization of the biologically active agent "enamel matrix derivative" (EMD), can be used for the regeneration of intrabony and Class II mandibular furcation periodontal defects. In cases where additional support and space-making requirements are necessary, both of these procedures can be combined with a bone replacement graft. There is no evidence that the combined use of GTR and EMD results in superior clinical results compared to the use of each material in isolation. Great variability in clinical outcomes has been reported in relation to the use of both EMD and GTR, and these procedures can be generally considered to be unpredictable. Careful case selection and treatment planning, including consideration of patient, tooth, site and surgical factors, is required in order to optimize the outcomes of treatment. There are limited data available for the clinical effectiveness of other biologically active molecules, such as growth factors and platelet concentrates, and although promising results have been reported, further clinical trials are required in order to confirm their effectiveness. Current active areas of research are centred on tissue engineering and gene therapy strategies which may result in more predictable regenerative outcomes in the future.

  12. Acute Page kidney following renal allograft biopsy: a complication requiring early recognition and treatment.

    Science.gov (United States)

    Chung, J; Caumartin, Y; Warren, J; Luke, P P W

    2008-06-01

    The acute Page kidney phenomenon occurs as a consequence of external compression of the renal parenchyma leading to renal ischemia and hypertension. Between January 2000 and September 2007, 550 kidney transplants and 518 ultrasound-guided kidney biopsies were performed. During that time, four recipients developed acute oligo-anuria following ultrasound-guided allograft biopsy. Emergent doppler-ultrasounds were performed demonstrating absence of diastolic flow as well as a sub-capsular hematoma of the kidney. Prompt surgical exploration with allograft capsulotomy was performed in all cases. Immediately after capsulotomy, intraoperative Doppler study demonstrated robust return of diastolic flow. Three patients maintained good graft function, and one kidney was lost due to acute antibody-mediated rejection. We conclude that postbiopsy anuria associated with a subcapsular hematoma and acute absence of diastolic flow on doppler ultrasound should be considered pathognomonic of APK. All renal transplant specialists should be able to recognize this complication, because immediate surgical decompression can salvage the allograft.

  13. In vitro regeneration of kidney from pluripotent stem cells

    Energy Technology Data Exchange (ETDEWEB)

    Osafune, Kenji, E-mail: osafu@cira.kyoto-u.ac.jp [Center for iPS Cell Research and Application (CiRA), Kyoto University, 53 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto 606-8507 (Japan); PRESTO, Japan Science and Technology Agency (JST), 4-1-8 Honcho, Kawaguchi, Saitama 332-0012 (Japan); JST Yamanaka iPS Cell Special Project, Japan Science and Technology Agency (JST), 4-1-8 Honcho, Kawaguchi, Saitama 332-0012 (Japan)

    2010-10-01

    Although renal transplantation has proved a successful treatment for the patients with end-stage renal failure, the therapy is hampered by the problem of serious shortage of donor organs. Regenerative medicine using stem cells, including cell transplantation therapy, needs to be developed to solve the problem. We previously identified the multipotent progenitor cells in the embryonic mouse kidney that can give rise to several kinds of epithelial cells found in adult kidney, such as glomerular podocytes and renal tubular epithelia. Establishing the method to generate the progenitors from human pluripotent stem cells that have the capacity to indefinitely proliferate in vitro is required for the development of kidney regeneration strategy. We review the current status of the research on the differentiation of pluripotent stem cells into renal lineages and describe cues to promote this research field.

  14. Human renal tubular cells contain CD24/CD133 progenitor cell populations: Implications for tubular regeneration after toxicant induced damage using cadmium as a model.

    Science.gov (United States)

    Shrestha, Swojani; Somji, Seema; Sens, Donald A; Slusser-Nore, Andrea; Patel, Divyen H; Savage, Evan; Garrett, Scott H

    2017-09-15

    The proximal tubules of the kidney are target sites of injury by various toxicants. Cadmium (Cd(+2)), an environmental nephrotoxicant can cause adverse effects and overt renal damage. To decipher the mechanisms involved in nephrotoxicity, an in vitro model system is required. Mortal cultures of human proximal tubule (HPT) cells have served, as models but are difficult to acquire and do not lend themselves to stable transfection. The immortalized human proximal tubule cell line HK-2, has served as a model but it lacks vectorial active transport and shows signs of lost epithelial features. Recently a new proximal tubule cell line was developed, the RPTEC/TERT1, and the goal of this study was to determine if this cell line could serve as a model to study nephrotoxicity. Global gene expression analysis of this cell line in comparison to the HK-2 and HPT cells showed that the RPTEC/TERT1 cells had gene expression patterns similar to HPT cells when compared to the HK-2 cells. The HPT and the RPTEC/TERT1 cell line had an increased population of stem/progenitor cells co-expressing CD24 and CD133 when compared to the HK-2 cells. The level of expression of cadherins, claudins and occludin molecules was also similar between the RPTEC/TERT1 and the HPT cells. Acute exposure to Cd(+2) resulted in necrosis of the RPTEC/TERT1 cells when compared to the HK-2 cells which died by apoptosis. Thus, the RPTEC/TERT1 cells are similar to HPT cells and can serve as a good model system to study mechanisms involved in toxicant induced renal damage. Copyright © 2017 Elsevier Inc. All rights reserved.

  15. Characteristics and outcomes of children with primary oxalosis requiring renal replacement therapy.

    NARCIS (Netherlands)

    Harambat, J.; Stralen, K.J. van; Espinosa, L.; Groothoff, J.W.; Hulton, S.A.; Cerkauskiene, R.; Schaefer, F.; Verrina, E.; Jager, K.J.; Cochat, P.; Hoitsma, A.J.; Hemke, A.C.

    2012-01-01

    BACKGROUND AND OBJECTIVES: Primary hyperoxaluria (PH) as a cause of ESRD in children is believed to have poor outcomes. Data on management and outcomes of these children remain scarce. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: This study included patients aged <19 years who started renal rep

  16. The Impact of Macro-and Micronutrients on Predicting Outcomes of Critically Ill Patients Requiring Continuous Renal Replacement Therapy.

    Directory of Open Access Journals (Sweden)

    Kittrawee Kritmetapak

    Full Text Available Critically ill patients with acute kidney injury (AKI who receive renal replacement therapy (RRT have very high mortality rate. During RRT, there are markedly loss of macro- and micronutrients which may cause malnutrition and result in impaired renal recovery and patient survival. We aimed to examine the predictive role of macro- and micronutrients on survival and renal outcomes in critically ill patients undergoing continuous RRT (CRRT. This prospective observational study enrolled critically ill patients requiring CRRT at Intensive Care Unit of King Chulalongkorn Memorial Hospital from November 2012 until November 2013. The serum, urine, and effluent fluid were serially collected on the first three days to calculate protein metabolism including dietary protein intake (DPI, nitrogen balance, and normalized protein catabolic rate (nPCR. Serum zinc, selenium, and copper were measured for micronutrients analysis on the first three days of CRRT. Survivor was defined as being alive on day 28 after initiation of CRRT.Dialysis status on day 28 was also determined. Of the 70 critically ill patients requiring CRRT, 27 patients (37.5% survived on day 28. The DPI and serum albumin of survivors were significantly higher than non-survivors (0.8± 0.2 vs 0.5 ±0.3g/kg/day, p = 0.001, and 3.2±0.5 vs 2.9±0.5 g/dL, p = 0.03, respectively while other markers were comparable. The DPI alone predicted patient survival with area under the curve (AUC of 0.69. A combined clinical model predicted survival with AUC of 0.78. When adjusted for differences in albumin level, clinical severity score (APACHEII and SOFA score, and serum creatinine at initiation of CRRT, DPI still independently predicted survival (odds ratio 4.62, p = 0.009. The serum levels of micronutrients in both groups were comparable and unaltered following CRRT. Regarding renal outcome, patients in the dialysis independent group had higher serum albumin levels than the dialysis dependent group, p = 0

  17. Bortezomib-based triplets are associated with a high probability of dialysis independence and rapid renal recovery in newly diagnosed myeloma patients with severe renal failure or those requiring dialysis.

    Science.gov (United States)

    Dimopoulos, Meletios A; Roussou, Maria; Gavriatopoulou, Maria; Psimenou, Erasmia; Eleutherakis-Papaiakovou, Evangelos; Migkou, Magdalini; Matsouka, Charis; Mparmparousi, Despoina; Gika, Dimitra; Kafantari, Eftychia; Ziogas, Dimitrios; Fotiou, Despoina; Panagiotidis, Ioannis; Terpos, Evangelos; Kastritis, Efstathios

    2016-05-01

    Renal failure (RF) is a common and severe complication of symptomatic myeloma, associated with significant morbidity and mortality. Such patients are commonly excluded from clinical trials. Bortezomib/dexamethasone (VD)-based regimens are the backbone of the treatment of newly diagnosed MM patients who present with severe RF even those requiring dialysis. We analyzed the outcomes of 83 consecutive bortezomib-treated patients with severe RF (eGFR dialysis. By IMWG renal response criteria, 54 (65%) patients achieved at least MRrenal, including CRrenal in 35% and PRrenal in 12%. Triplet combinations (i.e., VD plus a third agent) versus VD alone were associated with higher rates of renal responses (72 vs. 50%; P = 0.06). Fifteen of the 31 (48%) patients became dialysis independent within a median of 217 days (range 11-724). Triplets were associated with a higher probability of dialysis discontinuation (57 vs. 35%). Serum free light chain (sFLC) level ≥11,550 mg/L was associated with lower rates of major renal response, longer time to major renal response, lower probability, and longer time to dialysis discontinuation. Rapid myeloma response (≥PR within the first month) was also associated with higher rates of renal response. Patients who became dialysis-independent had longer survival than those remaining on dialysis. In conclusion, VD-based triplets are associated with a significant probability of renal response and dialysis discontinuation, improving the survival of patients who became dialysis independent. Rapid disease response is important for renal recovery and sFLCs are predictive of the probability and of the time required for renal response.

  18. Maternal, fetal and renal outcomes of pregnancy-associated acute kidney injury requiring dialysis.

    Science.gov (United States)

    Krishna, A; Singh, R; Prasad, N; Gupta, A; Bhadauria, D; Kaul, A; Sharma, R K; Kapoor, D

    2015-01-01

    Pregnancy-associated acute kidney injury (PAKI) is encountered frequently in developing countries. We evaluated the maternal, fetal and renal outcomes in women with PAKI who needed at least one session of dialysis. Of the total of 98 cases (mean age 28.85 ± 5.13 years; mean parity 2.65 ± 1.28) of PAKI, the most common cause of PAKI was postabortal sepsis. Eighteen patients died; those with oligoanuria, sepsis and central nervous system (CNS) involvement were at greater risk of mortality. The relative risk (RR) of neonatal mortality was lower after with full-term delivery (RR: 0.17, 95% confidence interval (CI): 0.03-0.96, P = 0.02) compared to preterm delivery. Of the 80 surviving patients, 60 (75%) patients achieved complete recovery of renal function at the end of 3 months; and of the remaining 14 had presumed (n = 4) or, biopsy-proven (n = 10) acute patchy cortical necrosis. The RR of non-recovery of renal function was high (RR: 24.7, 95% CI: 3.4- 179.5) in patients who did not recover at 6 weeks. Of the 14 patients with cortical necrosis, 3 (21.42%) became independent of dialysis at 6 months. PAKI patients should be watched for dialysis independency for 6 months.

  19. Rapamycin-Resistant mTOR Activity Is Required for Sensory Axon Regeneration Induced by a Conditioning Lesion

    OpenAIRE

    Chen, Weitao; Lu, Na; Ding, Yue; Wang, Yuan; Chan, Leung Ting; Wang, Xu; Gao, Xin; Jiang, Songshan; Liu, Kai

    2017-01-01

    Abstract Neuronal mammalian target of rapamycin (mTOR) activity is a critical determinant of the intrinsic regenerative ability of mature neurons in the adult central nervous system (CNS). However, whether its action also applies to peripheral nervous system (PNS) neurons after injury remains elusive. To address this issue unambiguously, we used genetic approaches to determine the role of mTOR signaling in sensory axon regeneration in mice. We showed that deleting mTOR in dorsal root ganglion...

  20. Requirement of retinoic acid receptor β for genipin derivative-induced optic nerve regeneration in adult rat retina.

    Directory of Open Access Journals (Sweden)

    Yoshiki Koriyama

    Full Text Available Like other CNS neurons, mature retinal ganglion cells (RGCs are unable to regenerate their axons after nerve injury due to a diminished intrinsic regenerative capacity. One of the reasons why they lose the capacity for axon regeneration seems to be associated with a dramatic shift in RGCs' program of gene expression by epigenetic modulation. We recently reported that (1R-isoPropyloxygenipin (IPRG001, a genipin derivative, has both neuroprotective and neurite outgrowth activities in murine RGC-5 retinal precursor cells. These effects were both mediated by nitric oxide (NO/S-nitrosylation signaling. Neuritogenic activity was mediated by S-nitrosylation of histone deacetylase-2 (HDAC2, which subsequently induced retinoic acid receptor β (RARβ expression via chromatin remodeling in vitro. RARβ plays important roles of neural growth and differentiation in development. However, the role of RARβ expression during adult rat optic nerve regeneration is not clear. In the present study, we extended this hypothesis to examine optic nerve regeneration by IPRG001 in adult rat RGCs in vivo. We found a correlation between RARβ expression and neurite outgrowth with age in the developing rat retina. Moreover, we found that IPRG001 significantly induced RARβ expression in adult rat RGCs through the S-nitrosylation of HDAC2 processing mechanism. Concomitant with RARβ expression, adult rat RGCs displayed a regenerative capacity for optic axons in vivo by IPRG001 treatment. These neuritogenic effects of IPRG001 were specifically suppressed by siRNA for RARβ. Thus, the dual neuroprotective and neuritogenic actions of genipin via S-nitrosylation might offer a powerful therapeutic tool for the treatment of RGC degenerative disorders.

  1. Actin-Cytoskeleton- and Rock-Mediated INM Are Required for Photoreceptor Regeneration in the Adult Zebrafish Retina

    OpenAIRE

    Lahne, Manuela; Li, Jingling; Marton, Rebecca M.; Hyde, David R.

    2015-01-01

    Loss of retinal neurons in adult zebrafish (Danio rerio) induces a robust regenerative response mediated by the reentry of the resident Müller glia into the cell cycle. Upon initiating Müller glia proliferation, their nuclei migrate along the apicobasal axis of the retina in phase with the cell cycle in a process termed interkinetic nuclear migration (INM). We examined the mechanisms governing this cellular process and explored its function in regenerating the adult zebrafish retina. Live-cel...

  2. The mitochondrial import gene tomm22 is specifically required for hepatocyte survival and provides a liver regeneration model

    Science.gov (United States)

    Curado, Silvia; Ober, Elke A.; Walsh, Susan; Cortes-Hernandez, Paulina; Verkade, Heather; Koehler, Carla M.; Stainier, Didier Y. R.

    2010-01-01

    SUMMARY Understanding liver development should lead to greater insights into liver diseases and improve therapeutic strategies. In a forward genetic screen for genes regulating liver development in zebrafish, we identified a mutant – oliver – that exhibits liver-specific defects. In oliver mutants, the liver is specified, bile ducts form and hepatocytes differentiate. However, the hepatocytes die shortly after their differentiation, and thus the resulting mutant liver consists mainly of biliary tissue. We identified a mutation in the gene encoding translocase of the outer mitochondrial membrane 22 (Tomm22) as responsible for this phenotype. Mutations in tomm genes have been associated with mitochondrial dysfunction, but most studies on the effect of defective mitochondrial protein translocation have been carried out in cultured cells or unicellular organisms. Therefore, the tomm22 mutant represents an important vertebrate genetic model to study mitochondrial biology and hepatic mitochondrial diseases. We further found that the temporary knockdown of Tomm22 levels by morpholino antisense oligonucleotides causes a specific hepatocyte degeneration phenotype that is reversible: new hepatocytes repopulate the liver as Tomm22 recovers to wild-type levels. The specificity and reversibility of hepatocyte ablation after temporary knockdown of Tomm22 provides an additional model to study liver regeneration, under conditions where most hepatocytes have died. We used this regeneration model to analyze the signaling commonalities between hepatocyte development and regeneration. PMID:20483998

  3. Rapamycin-Resistant mTOR Activity Is Required for Sensory Axon Regeneration Induced by a Conditioning Lesion.

    Science.gov (United States)

    Chen, Weitao; Lu, Na; Ding, Yue; Wang, Yuan; Chan, Leung Ting; Wang, Xu; Gao, Xin; Jiang, Songshan; Liu, Kai

    2016-01-01

    Neuronal mammalian target of rapamycin (mTOR) activity is a critical determinant of the intrinsic regenerative ability of mature neurons in the adult central nervous system (CNS). However, whether its action also applies to peripheral nervous system (PNS) neurons after injury remains elusive. To address this issue unambiguously, we used genetic approaches to determine the role of mTOR signaling in sensory axon regeneration in mice. We showed that deleting mTOR in dorsal root ganglion (DRG) neurons suppressed the axon regeneration induced by conditioning lesions. To establish whether the impact of mTOR on axon regeneration results from functions of mTOR complex 1 (mTORC1) or 2 (mTORC2), two distinct kinase complexes, we ablated either Raptor or Rictor in DRG neurons. We found that suppressing mTORC1 signaling dramatically decreased the conditioning lesion effect. In addition, an injury to the peripheral branch boosts mTOR activity in DRG neurons that cannot be completely inhibited by rapamycin, a widely used mTOR-specific inhibitor. Unexpectedly, examining several conditioning lesion-induced pro-regenerative pathways revealed that Raptor deletion but not rapamycin suppressed Stat3 activity in neurons. Therefore, our results demonstrate that crosstalk between mTOR and Stat3 signaling mediates the conditioning lesion effect and provide genetic evidence that rapamycin-resistant mTOR activity contributes to the intrinsic axon growth capacity in adult sensory neurons after injury.

  4. Cardiac-surgery associated acute kidney injury requiring renal replacement therapy. A Spanish retrospective case-cohort study

    Directory of Open Access Journals (Sweden)

    Garcia-Fernandez Nuria

    2009-09-01

    Full Text Available Abstract Background Acute kidney injury is among the most serious complications after cardiac surgery and is associated with an impaired outcome. Multiple factors may concur in the development of this disease. Moreover, severe renal failure requiring renal replacement therapy (RRT presents a high mortality rate. Consequently, we studied a Spanish cohort of patients to assess the risk factors for RRT in cardiac surgery-associated acute kidney injury (CSA-AKI. Methods A retrospective case-cohort study in 24 Spanish hospitals. All cases of RRT after cardiac surgery in 2007 were matched in a crude ratio of 1:4 consecutive patients based on age, sex, treated in the same year, at the same hospital and by the same group of surgeons. Results We analyzed the data from 864 patients enrolled in 2007. In multivariate analysis, severe acute kidney injury requiring postoperative RRT was significantly associated with the following variables: lower glomerular filtration rates, less basal haemoglobin, lower left ventricular ejection fraction, diabetes, prior diuretic treatment, urgent surgery, longer aortic cross clamp times, intraoperative administration of aprotinin, and increased number of packed red blood cells (PRBC transfused. When we conducted a propensity analysis using best-matched of 137 available pairs of patients, prior diuretic treatment, longer aortic cross clamp times and number of PRBC transfused were significantly associated with CSA-AKI. Patients requiring RRT needed longer hospital stays, and suffered higher mortality rates. Conclusion Cardiac-surgery associated acute kidney injury requiring RRT is associated with worse outcomes. For this reason, modifiable risk factors should be optimised and higher risk patients for acute kidney injury should be identified before undertaking cardiac surgery.

  5. The normal increase in insulin after a meal may be required to prevent postprandial renal sodium and volume losses.

    Science.gov (United States)

    Irsik, Debra L; Blazer-Yost, Bonnie L; Staruschenko, Alexander; Brands, Michael W

    2017-06-01

    Despite the effects of insulinopenia in type 1 diabetes and evidence that insulin stimulates multiple renal sodium transporters, it is not known whether normal variation in plasma insulin regulates sodium homeostasis physiologically. This study tested whether the normal postprandial increase in plasma insulin significantly attenuates renal sodium and volume losses. Rats were instrumented with chronic artery and vein catheters, housed in metabolic cages, and connected to hydraulic swivels. Measurements of urine volume and sodium excretion (UNaV) over 24 h and the 4-h postprandial period were made in control (C) rats and insulin-clamped (IC) rats in which the postprandial increase in insulin was prevented. Twenty-four-hour urine volume (36 ± 3 vs. 15 ± 2 ml/day) and UNaV (3.0 ± 0.2 vs. 2.5 ± 0.2 mmol/day) were greater in the IC compared with C rats, respectively. Four hours after rats were given a gel meal, blood glucose and urine volume were greater in IC rats, but UNaV decreased. To simulate a meal while controlling blood glucose, C and IC rats received a glucose bolus that yielded peak increases in blood glucose that were not different between groups. Urine volume (9.7 ± 0.7 vs. 6.0 ± 0.8 ml/4 h) and UNaV (0.50 ± 0.08 vs. 0.20 ± 0.06 mmol/4 h) were greater in the IC vs. C rats, respectively, over the 4-h test. These data demonstrate that the normal increase in circulating insulin in response to hyperglycemia may be required to prevent excessive renal sodium and volume losses and suggest that insulin may be a physiological regulator of sodium balance. Copyright © 2017 the American Physiological Society.

  6. Sphingosine-1-phosphate signalling induces the production of Lcn-2 by macrophages to promote kidney regeneration

    DEFF Research Database (Denmark)

    Sola, Anna; Weigert, Andreas; Jung, Michaela;

    2011-01-01

    the kidney. The present study describes a mechanism for renal tissue regeneration after ischaemia/reperfusion injury. Following injury, apoptotic cell-derived sphingosine-1-phosphate (S1P) or exogenously administered sphingosine analogue FTY720 activates macrophages to support the proliferation and healing......Inflammatory reactions are initiated to eliminate pathogens, but also to promote repair of damaged tissue after acute inflammation is terminated. In this regard, macrophages play a prominent role during induction as well as resolution of inflammation and injury in various organs including...... of renal epithelium, once inflammatory conditions are terminated. Both suppression of inflammation and renal regeneration might require S1P receptor 3 (S1P3) signalling and downstream release of neutrophil gelatinase-associated lipocalin (NGAL/Lcn-2) from macrophages. Overall, our data point...

  7. Regeneration and reprogramming compared

    Directory of Open Access Journals (Sweden)

    Robles Vanesa

    2010-01-01

    Full Text Available Abstract Background Dedifferentiation occurs naturally in mature cell types during epimorphic regeneration in fish and some amphibians. Dedifferentiation also occurs in the induction of pluripotent stem cells when a set of transcription factors (Oct4, Sox2, Klf4 and c-Myc is over expressed in mature cell types. Results We hypothesised that there are parallels between dedifferentiation or reprogramming of somatic cells to induced pluripotent stem cells and the natural process of dedifferentiation during epimorphic regeneration. We analysed expression levels of the most commonly used pluripotency associated factors in regenerating and non-regenerating tissue and compared them with levels in a pluripotent reference cell. We found that some of the pluripotency associated factors (oct4/pou5f1, sox2, c-myc, klf4, tert, sall4, zic3, dppa2/4 and fut1, a homologue of ssea1 were expressed before and during regeneration and that at least two of these factors (oct4, sox2 were also required for normal fin regeneration in the zebrafish. However these factors were not upregulated during regeneration as would be expected if blastema cells acquired pluripotency. Conclusions By comparing cells from the regeneration blastema with embryonic pluripotent reference cells we found that induced pluripotent stem and blastema cells do not share pluripotency. However, during blastema formation some of the key reprogramming factors are both expressed and are also required for regeneration to take place. We therefore propose a link between partially reprogrammed induced pluripotent stem cells and the half way state of blastema cells and suggest that a common mechanism might be regulating these two processes.

  8. CD248 expression on mesenchymal stromal cells is required for post‐natal and infection‐dependent thymus remodelling and regeneration

    National Research Council Canada - National Science Library

    Lax, Siân; Ross, Ewan A; White, Andrea; Marshall, Jennifer L; Jenkinson, William E; Isacke, Clare M; Huso, David L; Cunningham, Adam F; Anderson, Graham; Buckley, Christopher D

    2012-01-01

    ...‐natal thymus development and regeneration post‐ Salmonella infection. In CD248 −/− mice the thymus is hypocellular and regeneration is poorer, with significant loss of all thymocyte populations...

  9. Native Nephrectomy with Renal Transplantation is Associated with a Decrease in Hypertension Medication Requirements for Autosomal Dominant Polycystic Kidney Disease.

    Science.gov (United States)

    Shumate, Ashley M; Bahler, Clinton D; Goggins, William C; Sharfuddin, Asif A; Sundaram, Chandru P

    2016-01-01

    We assessed hypertensive control after native nephrectomy and renal transplantation in patients with autosomal dominant polycystic kidney disease. Blood pressure control was studied retrospectively in 118 patients with autosomal dominant polycystic kidney disease who underwent renal transplantation between 2003 and 2013. Overall 54 patients underwent transplantation alone (group 1) and 64 underwent transplantation with concurrent ipsilateral nephrectomy (group 2). Of these 64 patients 32 underwent ipsilateral nephrectomy only (group 2a) and 32 underwent eventual delayed contralateral native nephrectomy (group 2b). The number of antihypertensive drugs and defined daily dose of each antihypertensive was recorded at transplantation and up to 36-month followup. Comparing preoperative to postoperative medications at 12, 24 and 36-month followup, transplantation with concurrent ipsilateral nephrectomy had a greater decrease in quantity (-1.2 vs -0.5 medications, p=0.008; -1.1 vs -0.3, p=0.007 and -1.2 vs -0.4, p=0.03, respectively) and defined daily dose of antihypertensive drug (-3.3 vs -1.0, p=0.0008; -2.9 vs -1.0, p=0.006 and -2.7 vs -0.6, p=0.007, respectively) than transplantation alone at each point. Native nephrectomy continued to be a predictor of hypertensive requirements on multivariable analysis (p decrease in number of medications in group 2b from after ipsilateral nephrectomy to 12 months after contralateral nephrectomy was -0.6 (p=0.0005) and the mean decrease in defined daily dose was -0.6 (p=0.009). In patients with autosomal dominant polycystic kidney disease undergoing renal transplantation, concurrent ipsilateral native nephrectomy is associated with a significant decrease in the quantity and defined daily dose of antihypertensive drugs needed for hypertension control. Delayed contralateral native nephrectomy is associated with improved control of blood pressure to an even greater degree. Copyright © 2016 American Urological Association Education and

  10. Current Bioengineering Methods for Whole Kidney Regeneration

    Directory of Open Access Journals (Sweden)

    Shuichiro Yamanaka

    2015-01-01

    Full Text Available Kidney regeneration is likely to provide an inexhaustible source of tissues and organs for immunosuppression-free transplantation. It is currently garnering considerable attention and might replace kidney dialysis as the ultimate therapeutic strategy for renal failure. However, anatomical complications make kidney regeneration difficult. Here, we review recent advances in the field of kidney regeneration, including (i the directed differentiation of induced pluripotent stem cells/embryonic stem cells into kidney cells; (ii blastocyst decomplementation; (iii use of a decellularized cadaveric scaffold; (iv embryonic organ transplantation; and (v use of a nephrogenic niche for growing xenoembryos for de novo kidney regeneration from stem cells. All these approaches represent potentially promising therapeutic strategies for the treatment of patients with chronic kidney disease. Although many obstacles to kidney regeneration remain, we hope that innovative strategies and reliable research will ultimately allow the restoration of renal function in patients with end-stage kidney disease.

  11. Lactate clearance is associated with mortality in septic patients with acute kidney injury requiring continuous renal replacement therapy

    Science.gov (United States)

    Passos, Rogério da Hora; Ramos, Joao Gabriel Rosa; Gobatto, André; Mendonça, Evandro José Bulhões; Miranda, Eva Alves; Dutra, Fábio Ricardo Dantas; Coelho, Maria Fernanda R; Pedroza, Andrea C; Batista, Paulo Benigno Pena; Dutra, Margarida Maria Dantas

    2016-01-01

    Abstract The aim of the study was to assess the clinical utility of lactate measured at different time points to predict mortality at 48 hours and 28 days in septic patients with acute kidney injury (AKI) requiring continuous renal replacement therapy (CRRT). Consecutive critically ill patients with septic AKI requiring CRRT were prospectively studied. Variables were collected at initiation of CRRT and 24 hours later. In total, 186 patients were analyzed. Overall mortality at 48 hours was 28% and at 28 days was 69%. Initial lactate, lactate at 24 hours and the proportion of patients with a lactate clearance superior to 10% were different between survivors at 28 days [2.0 mmol/L, 1.95 mmol/L and 18/45 (40%)] and nonsurvivors [3.46 mmol, 4.66 mmol, and 18/94 (19%)]. Multivariate analysis demonstrated that lactate at 24 hours and lactate clearance, but not initial lactate, were independently associated to mortality. Area under the ROC curves for 28-day mortality was 0.635 for initial lactate; 0.828 for lactate at 24 hours and 0.701 for lactate clearance. Lactate clearance and lactate after 24 hours of CRRT, but not initial lactate, were independently associated with mortality in septic AKI patients undergoing CRRT. Serial lactate measurements may be useful prognostic markers than initial lactate in these patients. PMID:27749594

  12. TEAD transcription factors are required for normal primary myoblast differentiation in vitro and muscle regeneration in vivo.

    Science.gov (United States)

    Joshi, Shilpy; Davidson, Guillaume; Le Gras, Stéphanie; Watanabe, Shuichi; Braun, Thomas; Mengus, Gabrielle; Davidson, Irwin

    2017-02-01

    The TEAD family of transcription factors (TEAD1-4) bind the MCAT element in the regulatory elements of both growth promoting and myogenic differentiation genes. Defining TEAD transcription factor function in myogenesis has proved elusive due to overlapping expression of family members and their functional redundancy. We show that silencing of either Tead1, Tead2 or Tead4 did not effect primary myoblast (PM) differentiation, but that their simultaneous knockdown strongly impaired differentiation. In contrast, Tead1 or Tead4 silencing impaired C2C12 differentiation showing their different contributions in PMs and C2C12 cells. Chromatin immunoprecipitation identified enhancers associated with myogenic genes bound by combinations of Tead4, Myod1 or Myog. Tead4 regulated distinct gene sets in C2C12 cells and PMs involving both activation of the myogenic program and repression of growth and signaling pathways. ChIP-seq from mature mouse muscle fibres in vivo identified a set of highly transcribed muscle cell-identity genes and sites bound by Tead1 and Tead4. Although inactivation of Tead4 in mature muscle fibres caused no obvious phenotype under normal conditions, notexin-induced muscle regeneration was delayed in Tead4 mutants suggesting an important role in myogenic differentiation in vivo. By combining knockdown in cell models in vitro with Tead4 inactivation in muscle in vivo, we provide the first comprehensive description of the specific and redundant roles of Tead factors in myogenic differentiation.

  13. TEAD transcription factors are required for normal primary myoblast differentiation in vitro and muscle regeneration in vivo.

    Directory of Open Access Journals (Sweden)

    Shilpy Joshi

    2017-02-01

    Full Text Available The TEAD family of transcription factors (TEAD1-4 bind the MCAT element in the regulatory elements of both growth promoting and myogenic differentiation genes. Defining TEAD transcription factor function in myogenesis has proved elusive due to overlapping expression of family members and their functional redundancy. We show that silencing of either Tead1, Tead2 or Tead4 did not effect primary myoblast (PM differentiation, but that their simultaneous knockdown strongly impaired differentiation. In contrast, Tead1 or Tead4 silencing impaired C2C12 differentiation showing their different contributions in PMs and C2C12 cells. Chromatin immunoprecipitation identified enhancers associated with myogenic genes bound by combinations of Tead4, Myod1 or Myog. Tead4 regulated distinct gene sets in C2C12 cells and PMs involving both activation of the myogenic program and repression of growth and signaling pathways. ChIP-seq from mature mouse muscle fibres in vivo identified a set of highly transcribed muscle cell-identity genes and sites bound by Tead1 and Tead4. Although inactivation of Tead4 in mature muscle fibres caused no obvious phenotype under normal conditions, notexin-induced muscle regeneration was delayed in Tead4 mutants suggesting an important role in myogenic differentiation in vivo. By combining knockdown in cell models in vitro with Tead4 inactivation in muscle in vivo, we provide the first comprehensive description of the specific and redundant roles of Tead factors in myogenic differentiation.

  14. Liver regeneration.

    Science.gov (United States)

    Mao, Shennen A; Glorioso, Jaime M; Nyberg, Scott L

    2014-04-01

    The liver is unique in its ability to regenerate in response to injury. A number of evolutionary safeguards have allowed the liver to continue to perform its complex functions despite significant injury. Increased understanding of the regenerative process has significant benefit in the treatment of liver failure. Furthermore, understanding of liver regeneration may shed light on the development of cancer within the cirrhotic liver. This review provides an overview of the models of study currently used in liver regeneration, the molecular basis of liver regeneration, and the role of liver progenitor cells in regeneration of the liver. Specific focus is placed on clinical applications of current knowledge in liver regeneration, including small-for-size liver transplant. Furthermore, cutting-edge topics in liver regeneration, including in vivo animal models for xenogeneic human hepatocyte expansion and the use of decellularized liver matrices as a 3-dimensional scaffold for liver repopulation, are proposed. Unfortunately, despite 50 years of intense study, many gaps remain in the scientific understanding of liver regeneration.

  15. De Novo Kidney Regeneration with Stem Cells

    Directory of Open Access Journals (Sweden)

    Shinya Yokote

    2012-01-01

    Full Text Available Recent studies have reported on techniques to mobilize and activate endogenous stem-cells in injured kidneys or to introduce exogenous stem cells for tissue repair. Despite many recent advantages in renal regenerative therapy, chronic kidney disease (CKD remains a major cause of morbidity and mortality and the number of CKD patients has been increasing. When the sophisticated structure of the kidneys is totally disrupted by end stage renal disease (ESRD, traditional stem cell-based therapy is unable to completely regenerate the damaged tissue. This suggests that whole organ regeneration may be a promising therapeutic approach to alleviate patients with uncured CKD. We summarize here the potential of stem-cell-based therapy for injured tissue repair and de novo whole kidney regeneration. In addition, we describe the hurdles that must be overcome and possible applications of this approach in kidney regeneration.

  16. REGENERATION OF DRY DEBRIS-CONTAMINATED LUBRICATION

    Directory of Open Access Journals (Sweden)

    T. A. Ahmetov

    2011-01-01

    Full Text Available Industrial testing of regenerated lubricant in the process of wire drawing showed satisfactory quality (absence of gloss. It is determined that consumption of regenerated lubricant does not differ from consumption of new lubricant. Regenerated lubricant corresponds to the requirements of normative documents.

  17. Low-flow CO2 removal integrated into a renal-replacement circuit can reduce acidosis and decrease vasopressor requirements

    Science.gov (United States)

    2013-01-01

    Introduction Lung-protective ventilation in patients with ARDS and multiorgan failure, including renal failure, is often paralleled with a combined respiratory and metabolic acidosis. We assessed the effectiveness of a hollow-fiber gas exchanger integrated into a conventional renal-replacement circuit on CO2 removal, acidosis, and hemodynamics. Methods In ten ventilated critically ill patients with ARDS and AKI undergoing renal- and respiratory-replacement therapy, effects of low-flow CO2 removal on respiratory acidosis compensation were tested by using a hollow-fiber gas exchanger added to the renal-replacement circuit. This was an observational study on safety, CO2-removal capacity, effects on pH, ventilator settings, and hemodynamics. Results CO2 elimination in the low-flow circuit was safe and was well tolerated by all patients. After 4 hours of treatment, a mean reduction of 17.3 mm Hg (−28.1%) pCO2 was observed, in line with an increase in pH. In hemodynamically instable patients, low-flow CO2 elimination was paralleled by hemodynamic improvement, with an average reduction of vasopressors of 65% in five of six catecholamine-dependent patients during the first 24 hours. Conclusions Because no further catheters are needed, besides those for renal replacement, the implementation of a hollow-fiber gas exchanger in a renal circuit could be an attractive therapeutic tool with only a little additional trauma for patients with mild to moderate ARDS undergoing invasive ventilation with concomitant respiratory acidosis, as long as no severe oxygenation defects indicate ECMO therapy. PMID:23883472

  18. Bioelectricity and epimorphic regeneration.

    Science.gov (United States)

    Stewart, Scott; Rojas-Muñoz, Agustin; Izpisúa Belmonte, Juan Carlos

    2007-11-01

    All cells have electric potentials across their membranes, but is there really compelling evidence to think that such potentials are used as instructional cues in developmental biology? Numerous reports indicate that, in fact, steady, weak bioelectric fields are observed throughout biology and function during diverse biological processes, including development. Bioelectric fields, generated upon amputation, are also likely to play a key role during vertebrate regeneration by providing the instructive cues needed to direct migrating cells to form a wound epithelium, a structure unique to regenerating animals. However, mechanistic insight is still sorely lacking in the field. What are the genes required for bioelectric-dependent cell migration during regeneration? The power of genetics combined with the use of zebrafish offers the best opportunity for unbiased identification of the molecular players in bioelectricity.

  19. Perfluorodecalin and bone regeneration

    Directory of Open Access Journals (Sweden)

    F Tamimi

    2013-01-01

    Full Text Available Perfluorodecalin (PFD is a chemically and biologically inert biomaterial and, as many perfluorocarbons, is also hydrophobic, radiopaque and has a high solute capacity for gases such as oxygen. In this article we have demonstrated, both in vitro and in vivo, that PFD may significantly enhance bone regeneration. Firstly, the potential benefit of PFD was demonstrated by prolonging the survival of bone marrow cells cultured in anaerobic conditions. These findings translated in vivo, where PFD incorporated into bone-marrow-loaded 3D-printed scaffolds substantially improved their capacity to regenerate bone. Secondly, in addition to biological applications, we have also shown that PFD improves the radiopacity of bone regeneration biomaterials, a key feature required for the visualisation of biomaterials during and after surgical implantation. Finally, we have shown how the extreme hydrophobicity of PFD enables the fabrication of highly cohesive self-setting injectable biomaterials for bone regeneration. In conclusion, perfluorocarbons would appear to be highly beneficial additives to a number of regenerative biomaterials, especially those for bone regeneration.

  20. Instructive composites for bone regeneration

    NARCIS (Netherlands)

    Barbieri, D.

    2012-01-01

    Developing new biomaterials for tissue regeneration requires careful balance between many factors, which is challenging because, on one side, such materials must provide complex information, through their physicochemical properties to actively interact with the biological surroundings and induce tis

  1. Transfusion requirements and clinical outcome in intensive care patients receiving continuous renal replacement therapy: comparison of prostacyclin vs. heparin prefilter administration

    DEFF Research Database (Denmark)

    Windeløv, Nis Agerlin; Ostrowski, Sisse R; Perner, Anders;

    2010-01-01

    Prostacyclin (PGI(2)) analogous are potent antithrombotics recommended as prefilter infusion during renal replacement therapy (RRT) when heparin is contraindicated. It is debated whether PGI(2) administration during RRT affects transfusion requirements and outcome. Retrospective cohort study of a...... intravascular coagulation (DIC) (P=0.006), severe thrombocytopenia (P=0.03), higher maximum Sequential Organ Failure Assessment score (P......: before, during and after CRRT. For each time period, laboratory values were analysed as changes/day and blood transfusion requirements as absolute values. Organ failures during the ICU stay and 1 year all-cause mortality were registered. During CRRT the PGI(2) group had a higher incidence of disseminated...

  2. CNNM2, encoding a basolateral protein required for renal Mg2+ handling, is mutated in dominant hypomagnesemia

    NARCIS (Netherlands)

    Stuiver, M.; Lainez, S.; Will, C.; Terryn, S.; Gunzel, D.; Debaix, H.; Sommer, K.; Kopplin, K.; Thumfart, J.; Kampik, N.B.; Querfeld, U.; Willnow, T.E.; Nemec, V.; Wagner, C.A.; Hoenderop, J.G.J.; Devuyst, O.; Knoers, N.V.A.M.; Bindels, R.J.M.; Meij, I.C.; Muller, D.

    2011-01-01

    Familial hypomagnesemia is a rare human disorder caused by renal or intestinal magnesium (Mg(2+)) wasting, which may lead to symptoms of Mg(2+) depletion such as tetany, seizures, and cardiac arrhythmias. Our knowledge of the physiology of Mg(2+) (re)absorption, particularly the luminal uptake of

  3. Perioperative acute renal failure.

    LENUS (Irish Health Repository)

    Mahon, Padraig

    2012-02-03

    PURPOSE OF REVIEW: Recent biochemical evidence increasingly implicates inflammatory mechanisms as precipitants of acute renal failure. In this review, we detail some of these pathways together with potential new therapeutic targets. RECENT FINDINGS: Neutrophil gelatinase-associated lipocalin appears to be a sensitive, specific and reliable biomarker of renal injury, which may be predictive of renal outcome in the perioperative setting. For estimation of glomerular filtration rate, cystatin C is superior to creatinine. No drug is definitively effective at preventing postoperative renal failure. Clinical trials of fenoldopam and atrial natriuretic peptide are, at best, equivocal. As with pharmacological preconditioning of the heart, volatile anaesthetic agents appear to offer a protective effect to the subsequently ischaemic kidney. SUMMARY: Although a greatly improved understanding of the pathophysiology of acute renal failure has offered even more therapeutic targets, the maintenance of intravascular euvolaemia and perfusion pressure is most effective at preventing new postoperative acute renal failure. In the future, strategies targeting renal regeneration after injury will use bone marrow-derived stem cells and growth factors such as insulin-like growth factor-1.

  4. egr-4, a target of EGFR signaling, is required for the formation of the brain primordia and head regeneration in planarians.

    Science.gov (United States)

    Fraguas, Susanna; Barberán, Sara; Iglesias, Marta; Rodríguez-Esteban, Gustavo; Cebrià, Francesc

    2014-05-01

    During the regeneration of freshwater planarians, polarity and patterning programs play essential roles in determining whether a head or a tail regenerates at anterior or posterior-facing wounds. This decision is made very soon after amputation. The pivotal role of the Wnt/β-catenin and Hh signaling pathways in re-establishing anterior-posterior (AP) polarity has been well documented. However, the mechanisms that control the growth and differentiation of the blastema in accordance with its AP identity are less well understood. Previous studies have described a role of Smed-egfr-3, a planarian epidermal growth factor receptor, in blastema growth and differentiation. Here, we identify Smed-egr-4, a zinc-finger transcription factor belonging to the early growth response gene family, as a putative downstream target of Smed-egfr-3. Smed-egr-4 is mainly expressed in the central nervous system and its silencing inhibits anterior regeneration without affecting the regeneration of posterior regions. Single and combinatorial RNA interference to target different elements of the Wnt/β-catenin pathway, together with expression analysis of brain- and anterior-specific markers, revealed that Smed-egr-4: (1) is expressed in two phases - an early Smed-egfr-3-independent phase and a late Smed-egfr-3-dependent phase; (2) is necessary for the differentiation of the brain primordia in the early stages of regeneration; and (3) that it appears to antagonize the activity of the Wnt/β-catenin pathway to allow head regeneration. These results suggest that a conserved EGFR/egr pathway plays an important role in cell differentiation during planarian regeneration and indicate an association between early brain differentiation and the proper progression of head regeneration.

  5. Tumor necrosis factor-alpha is produced by dying retinal neurons and is required for Muller glia proliferation during zebrafish retinal regeneration.

    Science.gov (United States)

    Nelson, Craig M; Ackerman, Kristin M; O'Hayer, Patrick; Bailey, Travis J; Gorsuch, Ryne A; Hyde, David R

    2013-04-10

    Intense light exposure causes photoreceptor apoptosis in dark-adapted adult albino zebrafish (Danio rerio). Subsequently, Müller glia increase expression of the Achaete-scute complex-like 1a (Ascl1a) and Signal transducer and activator of transcription 3 (Stat3) transcription factors and re-enter the cell cycle to yield undifferentiated neuronal progenitors that continue to proliferate, migrate to the outer nuclear layer, and differentiate into photoreceptors. A proteomic analysis of light-damaged retinal homogenates, which induced Müller glia proliferation when injected into an undamaged eye, revealed increased expression of tumor necrosis factor α (TNFα) signaling proteins relative to undamaged retinal homogenates. TNFα expression initially increased in apoptotic photoreceptors and later in Müller glia. Morpholino-mediated knockdown of TNFα expression before light damage diminished the expression of both Ascl1a and Stat3 in Müller glia and significantly reduced the number of proliferating Müller glia without affecting photoreceptor cell death. Knockdown of TNFα expression in the Müller glia resulted in fewer proliferating Müller glia, suggesting that Müller glial-derived TNFα recruited additional Müller glia to re-enter the cell cycle. While TNFα is required for increased Ascl1a and Stat3 expression, Ascl1a and Stat3 are both necessary for TNFα expression in Müller glia. Apoptotic inner retinal neurons, resulting from intravitreal injection of ouabain, also exhibited increased TNFα expression that was required for Müller glia proliferation. Thus, TNFα is the first molecule identified that is produced by dying retinal neurons and is necessary to induce Müller glia to proliferate in the zebrafish retinal regeneration response.

  6. Tumor necrosis factor-alpha is produced by dying retinal neurons and is required for Müller glia proliferation during zebrafish retinal regeneration

    Science.gov (United States)

    Nelson, Craig M.; Ackerman, Kristin M.; O’Hayer, Patrick; Bailey, Travis J.; Gorsuch, Ryne A.; Hyde, David R.

    2013-01-01

    Intense light exposure causes photoreceptor apoptosis in dark-adapted adult albino zebrafish (Danio rerio). Subsequently, Müller glia increase expression of the Achaete-scute complex-like 1a (Ascl1a) and Signal transducer and activator of transcription 3(Stat3) transcription factors and reenter the cell cycle to yield undifferentiated neuronal progenitors that continue to proliferate, migrate to the outer nuclear layer, and differentiate into photoreceptors. A proteomic analysis of light-damaged retinal homogenates, which induced Müller glia proliferation when injected into an undamaged eye, revealed increased expression of Tumor necrosis factor α (TNFα) signaling proteins relative to undamaged retinal homogenates. TNFα expression initially increased in apoptotic photoreceptors and later in Müller glia. Morpholino-mediated knockdown of TNFα expression prior to light damage diminished the expression of both Ascl1a and Stat3 in Müller glia and significantly reduced the number of proliferating Müller glia without affecting photoreceptor cell death. Knockdown of TNFα expression in the Müller glia resulted in fewer proliferating Müller glia, suggesting that Müller glial-derived TNFα recruited additional Müller glia to reenter the cell cycle. While TNFα is required for increased Ascl1a and Stat3 expression, Ascl1a and Stat3 are both necessary for TNFα expression in Müller glia. Apoptotic inner retinal neurons, resulting from intravitreal injection of ouabain, also exhibited increased TNFα expression that was required for Müller glia proliferation. Thus, TNFα is the first molecule identified that is produced by dying retinal neurons and is necessary to induce Müller glia to proliferate in the zebrafish retinal regeneration response. PMID:23575850

  7. My Regeneration:

    DEFF Research Database (Denmark)

    Carter, Dale

    2016-01-01

    and cultural referents shows that it offers an index to the album. Using its frontier setting and a variety of sacred and secular myths, symbols and icons, ‘Heroes and Villains,’ like Smile as a whole, offers historically-informed visions of national decline, crisis and regeneration that are at once critical...

  8. CRISPR-mediated genomic deletion of Sox2 in the axolotl shows a requirement in spinal cord neural stem cell amplification during tail regeneration.

    Science.gov (United States)

    Fei, Ji-Feng; Schuez, Maritta; Tazaki, Akira; Taniguchi, Yuka; Roensch, Kathleen; Tanaka, Elly M

    2014-09-09

    The salamander is the only tetrapod that functionally regenerates all cell types of the limb and spinal cord (SC) and thus represents an important regeneration model, but the lack of gene-knockout technology has limited molecular analysis. We compared transcriptional activator-like effector nucleases (TALENs) and clustered regularly interspaced short palindromic repeats (CRISPRs) in the knockout of three loci in the axolotl and find that CRISPRs show highly penetrant knockout with less toxic effects compared to TALENs. Deletion of Sox2 in up to 100% of cells yielded viable F0 larvae with normal SC organization and ependymoglial cell marker expression such as GFAP and ZO-1. However, upon tail amputation, neural stem cell proliferation was inhibited, resulting in spinal-cord-specific regeneration failure. In contrast, the mesodermal blastema formed normally. Sox3 expression during development, but not regeneration, most likely allowed embryonic survival and the regeneration-specific phenotype. This analysis represents the first tissue-specific regeneration phenotype from the genomic deletion of a gene in the axolotl.

  9. CRISPR-Mediated Genomic Deletion of Sox2 in the Axolotl Shows a Requirement in Spinal Cord Neural Stem Cell Amplification during Tail Regeneration

    Directory of Open Access Journals (Sweden)

    Ji-Feng Fei

    2014-09-01

    Full Text Available The salamander is the only tetrapod that functionally regenerates all cell types of the limb and spinal cord (SC and thus represents an important regeneration model, but the lack of gene-knockout technology has limited molecular analysis. We compared transcriptional activator-like effector nucleases (TALENs and clustered regularly interspaced short palindromic repeats (CRISPRs in the knockout of three loci in the axolotl and find that CRISPRs show highly penetrant knockout with less toxic effects compared to TALENs. Deletion of Sox2 in up to 100% of cells yielded viable F0 larvae with normal SC organization and ependymoglial cell marker expression such as GFAP and ZO-1. However, upon tail amputation, neural stem cell proliferation was inhibited, resulting in spinal-cord-specific regeneration failure. In contrast, the mesodermal blastema formed normally. Sox3 expression during development, but not regeneration, most likely allowed embryonic survival and the regeneration-specific phenotype. This analysis represents the first tissue-specific regeneration phenotype from the genomic deletion of a gene in the axolotl.

  10. Acoustic field modulation in regenerators

    Science.gov (United States)

    Hu, J. Y.; Wang, W.; Luo, E. C.; Chen, Y. Y.

    2016-12-01

    The regenerator is a key component that transfers energy between heat and work. The conversion efficiency is significantly influenced by the acoustic field in the regenerator. Much effort has been spent to quantitatively determine this influence, but few comprehensive experimental verifications have been performed because of difficulties in modulating and measuring the acoustic field. In this paper, a method requiring two compressors is introduced and theoretically investigated that achieves acoustic field modulation in the regenerator. One compressor outputs the acoustic power for the regenerator; the other acts as a phase shifter. A RC load dissipates the acoustic power out of both the regenerator and the latter compressor. The acoustic field can be modulated by adjusting the current in the two compressors and opening the RC load. The acoustic field is measured with pressure sensors instead of flow-field imaging equipment, thereby greatly simplifying the experiment.

  11. fgf20 is essential for initiating zebrafish fin regeneration.

    Science.gov (United States)

    Whitehead, Geoffrey G; Makino, Shinji; Lien, Ching-Ling; Keating, Mark T

    2005-12-23

    Epimorphic regeneration requires the presence or creation of pluripotent cells capable of reproducing lost organs. Zebrafish fin regeneration is mediated by the creation of blastema cells. Here, we characterize the devoid of blastema (dob) mutant that fails fin regeneration during initial steps, forms abnormal regeneration epithelium, and does not form blastema. This mutation has no impact on embryonic survival. Dob results from an fgf20a null mutation, Y148S. Fgf20a is expressed during initiation of fin regeneration at the epithelial-mesenchymal boundary and later overlaps with the blastema marker msxb. Thus, fgf20a has a regeneration-specific requirement, initiating fin regeneration, and controlling blastema formation.

  12. Estimativa das necessidades energéticas em pacientes com doença renal crônica Estimating the energy requirement of chronic kidney disease patients

    Directory of Open Access Journals (Sweden)

    Juliana Cordeiro Dias Rodrigues

    2013-02-01

    Full Text Available Estabelecer as necessidades energéticas de pacientes com doença renal crônica é importante para que se possam tratar os distúrbios nutricionais encontrados nessa população. Segundo os guias de condutas voltados ao cuidado nutricional de pacientes com essa doença, a recomendação energética pode variar entre 30 e 40kcal/kg/dia. Contudo, trabalhos que avaliaram os componentes do gasto energético nos pacientes com doença renal crônica sugerem que as necessidades energéticas dessa população podem diferir do valor recomendado acima, a depender da condição clínica (presença de comorbidades, da modalidade de tratamento empregado e do nível de atividade física. Dessa forma, o presente trabalho tem como objetivo fazer uma revisão dos estudos sobre o gasto energético de pacientes com doença renal crônica, com o intuito de abordar as seguintes questões: (1 as atuais recomendações de energia para pacientes com doença renal crônica estão adequadas? (2 qual equação de predição poderia ser empregada para estimar as necessidades energéticas desse grupo de pacientes? Assim, esta revisão busca auxiliar o nutricionista ao estimar as necessidades energéticas de pacientes com doença renal crônica.Estimating the energy requirement of patients with chronic kidney disease is highly important for treating the nutritional disorders often seen in this population. According to the specific guidelines for patients with chronic kidney disease, the currently recommended daily energy intake varies from 30 to 40kcal/kg/day. However, studies that investigated energy expenditure components of patients with chronic kidney disease suggested that the energy requirement may differ from the one proposed earlier, depending on overall clinical condition (i.e. presence of comorbidities, treatment modality and level of physical activity. With this perspective in mind, the present study aims to review the studies assessing energy expenditure

  13. Potential molecular therapy for acute renal failure.

    Science.gov (United States)

    Humes, H D

    1993-01-01

    Ischemic and toxic acute renal failure is reversible, due to the ability of renal tubule cells to regenerate and differentiate into a fully functional lining epithelium. Recent data support the thesis that recruitment or activation of macrophages to the area of injury results in local release of growth factors to promote regenerative repair. Because of intrinsic delay in the recruitment of inflammatory cells, the exogenous administration of growth promoters early in the repair phase of acute renal failure enhances renal tubule cell regeneration and accelerates renal functional recovery in animal models of acute renal failure. Molecular therapy for the acceleration of tissue repair in this disease process may be developed in the near future.

  14. Effects of dialysis modality on blood loss, bleeding complications and transfusion requirements in critically ill patients with dialysis-dependent acute renal failure.

    Science.gov (United States)

    Pschowski, R; Briegel, S; Von Haehling, S; Doehner, W; Bender, T O; Pape, U F; Hasper, D; Jörress, A; Schefold, J C

    2015-11-01

    Blood loss and bleeding complications may often be observed in critically ill patients on renal replacement therapies (RRT). Here we investigate procedural (i.e. RRT-related) and non-procedural blood loss as well as transfusion requirements in regard to the chosen mode of dialysis (i.e. intermittent haemodialysis [IHD] versus continuous veno-venous haemofiltration [CVVH]). Two hundred and fifty-two patients (122 CVVH, 159 male; aged 61.5±13.9 years) with dialysis-dependent acute renal failure were analysed in a sub-analysis of the prospective randomised controlled clinical trial-CONVINT-comparing IHD and CVVH. Bleeding complications including severity of bleeding and RRT-related blood loss were assessed. We observed that 3.6% of patients died related to severe bleeding episodes (between group P=0.94). Major all-cause bleeding complications were observed in 23% IHD versus 26% of CVVH group patients (P=0.95). Under CVVH, the rate of RRT-related blood loss events (57.4% versus 30.4%, P=0.01) and mean total blood volume lost was increased (222.3±291.9 versus 112.5±222.7 ml per patient, P dialysis-dependent acute renal failure in this regard.

  15. Stat3 defines three populations of Müller glia and is required for initiating maximal müller glia proliferation in the regenerating zebrafish retina.

    Science.gov (United States)

    Nelson, Craig M; Gorsuch, Ryne A; Bailey, Travis J; Ackerman, Kristin M; Kassen, Sean C; Hyde, David R

    2012-12-15

    We analyzed the role of Stat3, Ascl1a, and Lin28a in Müller glia reentry into the cell cycle following damage to the zebrafish retina. Immunohistochemical analysis was employed to determine the temporal and spatial expression of Stat3 and Ascl1a proteins following rod and cone photoreceptor cell apoptosis. Stat3 expression was observed in all Müller glia, whereas Ascl1a expression was restricted to only the mitotic Müller glia. Knockdown of Stat3 protein expression did not affect photoreceptor apoptosis, but significantly reduced, without abolishing, the number of proliferating Ascl1a-positive Müller glia. Knockdown of Ascl1a protein also did not change the extent of photoreceptor apoptosis, but did yield significantly fewer Müller glia that reentered the cell cycle relative to the stat3 morphant and significantly decreased the number and intensity of Stat3-expressing Müller glia. Finally, introduction of lin28a morpholinos resulted in decreased Müller glia expression of Stat3 and Ascl1a, significantly reducing the number of proliferating Müller glia. Thus, there are three populations of Müller glia in the light-damaged zebrafish retina: 1) Stat3-expressing Ascl1a-nonexpressing nonproliferating (quiescent) Müller glia; 2) Stat3-dependent Ascl1a-dependent proliferating Müller glia; and 3) Stat3-independent Ascl1a-dependent proliferating Müller glia. Whereas Ascl1a and Lin28a are required for Müller glia proliferation, Stat3 is necessary for the maximal number of Müller glia to proliferate during regeneration of the damaged zebrafish retina.

  16. The Microtubule Minus-End-Binding Protein Patronin/PTRN-1 Is Required for Axon Regeneration in C. elegans

    Directory of Open Access Journals (Sweden)

    Marian Chuang

    2014-11-01

    Full Text Available Precise regulation of microtubule (MT dynamics is increasingly recognized as a critical determinant of axon regeneration. In contrast to developing neurons, mature axons exhibit noncentrosomal microtubule nucleation. The factors regulating noncentrosomal MT architecture in axon regeneration remain poorly understood. We report that PTRN-1, the C. elegans member of the Patronin/Nezha/calmodulin- and spectrin-associated protein (CAMSAP family of microtubule minus-end-binding proteins, is critical for efficient axon regeneration in vivo. ptrn-1-null mutants display generally normal developmental axon outgrowth but significantly impaired regenerative regrowth after laser axotomy. Unexpectedly, mature axons in ptrn-1 mutants display elevated numbers of dynamic axonal MTs before and after injury, suggesting that PTRN-1 inhibits MT dynamics. The CKK domain of PTRN-1 is necessary and sufficient for its functions in axon regeneration and MT dynamics and appears to stabilize MTs independent of minus-end localization. Whereas in developing neurons, PTRN-1 inhibits activity of the DLK-1 mitogen-activated protein kinase (MAPK cascade, we find that, in regeneration, PTRN-1 and DLK-1 function together to promote axonal regrowth.

  17. Renal stem cells: fact or science fiction?

    Science.gov (United States)

    McCampbell, Kristen K; Wingert, Rebecca A

    2012-06-01

    The kidney is widely regarded as an organ without regenerative abilities. However, in recent years this dogma has been challenged on the basis of observations of kidney recovery following acute injury, and the identification of renal populations that demonstrate stem cell characteristics in various species. It is currently speculated that the human kidney can regenerate in some contexts, but the mechanisms of renal regeneration remain poorly understood. Numerous controversies surround the potency, behaviour and origins of the cell types that are proposed to perform kidney regeneration. The present review explores the current understanding of renal stem cells and kidney regeneration events, and examines the future challenges in using these insights to create new clinical treatments for kidney disease.

  18. Transfusion requirements and clinical outcome in intensive care patients receiving continuous renal replacement therapy: comparison of prostacyclin vs. heparin prefilter administration

    DEFF Research Database (Denmark)

    Windeløv, Nis Agerlin; Ostrowski, Sisse R; Perner, Anders;

    2010-01-01

    Prostacyclin (PGI(2)) analogous are potent antithrombotics recommended as prefilter infusion during renal replacement therapy (RRT) when heparin is contraindicated. It is debated whether PGI(2) administration during RRT affects transfusion requirements and outcome. Retrospective cohort study of all...... patients at a general intensive care unit (ICU) receiving continuous RRT (CRRT) in a 14-month period. Patients were stratified according to the used anticoagulant, that is prefilter PGI(2) group (n=24) and prefilter heparin group (n=70). The ICU stay of the patients was divided into three time periods...

  19. Trauma renal Renal trauma

    Directory of Open Access Journals (Sweden)

    Gerson Alves Pereira Júnior

    1999-02-01

    Full Text Available Apresentamos uma revisão sobre trauma renal, com ênfase na avaliação radiológica, particularmente com o uso da tomografia computadorizada, que tem se tornado o exame de eleição, ao invés da urografia excretora e arteriografia. O sucesso no tratamento conservador dos pacientes com trauma renal depende de um acurado estadiamento da extensão da lesão, classificado de acordo com a Organ Injury Scaling do Colégio Americano de Cirurgiões. O tratamento conservador não-operatório é seguro e consiste de observação contínua, repouso no leito, hidratação endovenosa adequada e antibioti- coterapia profilática, evitando-se uma exploração cirúrgica desnecessária e possível perda renal. As indicações para exploração cirúrgica imediata são abdome agudo, rápida queda do hematócrito ou lesões associadas determinadas na avaliação radiológica. Quando indicada, a exploração renal após controle vascular prévio é segura, permitindo cuidadosa inspeção do rim e sua reconstrução com sucesso, reduzindo a probabilidade de nefrectomia.We present a revision of the renal trauma with emphasis in the radiographic evaluation, particularly CT scan that it has largely replaced the excretory urogram and arteriogram in the diagnostic worh-up and management of the patient with renal trauma. The successful management of renal injuries depends upon the accurate assessment of their extent in agreement with Organ Injury Scaling classification. The conservative therapy managed by careful continuous observation, bed rest, appropriate fluid ressuscitation and prophylactic antibiotic coverage after radiographic staging for severely injured kidneys can yield favorable results and save patients from unnecessary exploration and possible renal loss. The indications for immediate exploratory laparotomy were acute abdomen, rapidly dropping hematocrit or associated injuries as determinated from radiologic evaluation. When indicated, renal exploration

  20. Renal tubule cell repair following acute renal injury.

    Science.gov (United States)

    Humes, H D; Lake, E W; Liu, S

    1995-01-01

    Experimental data suggests the recovery of renal function after ischemic or nephrotoxic acute renal failure is due to a replicative repair process dependent upon predominantly paracrine release of growth factors. These growth factors promote renal proximal tubule cell proliferation and a differentiation phase dependent on the interaction between tubule cells and basement membrane. These insights identify the molecular basis of renal repair and ischemic and nephrotoxic acute renal failure, and may lead to potential therapeutic modalities that accelerate renal repair and lessen the morbidity and mortality associated with these renal disease processes. In this regard, there is a prominent vasoconstrictor response of the renal vasculature during the postischemic period of developing acute renal failure. The intravenous administration of pharmacologic doses of atrial natriuretic factor (ANF) in the postischemic period have proven efficacious by altering renal vascular resistance, so that renal blood flow and glomerular filtration rate improve. ANF also appears to protect renal tubular epithelial integrity and holds significant promise as a therapeutic agent in acute renal failure. Of equal or greater promise are the therapeutic interventions targeting the proliferative reparative zone during the postischemic period. The exogenous administration of epidermal growth factor or insulin-like growth factor-1 in the postischemic period have effectively decreased the degree of renal insufficiency as measured by the peak serum creatinine and has hastened renal recovery as measured by the duration of time required to return the baseline serum creatinine values. A similarly efficacious role for hepatocyte growth factor has also been recently demonstrated.

  1. Renal arteriography

    Science.gov (United States)

    ... Read More Acute arterial occlusion - kidney Acute kidney failure Aneurysm Atheroembolic renal disease Blood clots Renal cell carcinoma Renal venogram X-ray Review Date 1/5/2016 Updated by: Jason Levy, ...

  2. Nerves Regulate Cardiomyocyte Proliferation and Heart Regeneration.

    Science.gov (United States)

    Mahmoud, Ahmed I; O'Meara, Caitlin C; Gemberling, Matthew; Zhao, Long; Bryant, Donald M; Zheng, Ruimao; Gannon, Joseph B; Cai, Lei; Choi, Wen-Yee; Egnaczyk, Gregory F; Burns, Caroline E; Burns, C Geoffrey; MacRae, Calum A; Poss, Kenneth D; Lee, Richard T

    2015-08-24

    Some organisms, such as adult zebrafish and newborn mice, have the capacity to regenerate heart tissue following injury. Unraveling the mechanisms of heart regeneration is fundamental to understanding why regeneration fails in adult humans. Numerous studies have revealed that nerves are crucial for organ regeneration, thus we aimed to determine whether nerves guide heart regeneration. Here, we show using transgenic zebrafish that inhibition of cardiac innervation leads to reduction of myocyte proliferation following injury. Specifically, pharmacological inhibition of cholinergic nerve function reduces cardiomyocyte proliferation in the injured hearts of both zebrafish and neonatal mice. Direct mechanical denervation impairs heart regeneration in neonatal mice, which was rescued by the administration of neuregulin 1 (NRG1) and nerve growth factor (NGF) recombinant proteins. Transcriptional analysis of mechanically denervated hearts revealed a blunted inflammatory and immune response following injury. These findings demonstrate that nerve function is required for both zebrafish and mouse heart regeneration.

  3. Investment in seed physical defence is associated with species' light requirement for regeneration and seed persistence: evidence from Macaranga species in Borneo

    Science.gov (United States)

    The life stage from seed dispersal to seedling emergence is often critical in determining the regeneration success of plants. During this period seeds must survive an array of seed predators and pathogens and germinate under conditions favorable for seedling establishment. To maximise recruitment s...

  4. Fgfr4 is required for effective muscle regeneration in vivo. Delineation of a MyoD-Tead2-Fgfr4 transcriptional pathway.

    Science.gov (United States)

    Zhao, Po; Caretti, Giuseppina; Mitchell, Stephanie; McKeehan, Wallace L; Boskey, Adele L; Pachman, Lauren M; Sartorelli, Vittorio; Hoffman, Eric P

    2006-01-06

    Fgfr4 has been shown to be important for appropriate muscle development in chick limb buds; however, Fgfr4 null mice show no phenotype. Here, we show that staged induction of muscle regeneration in Fgfr4 null mice becomes highly abnormal at the time point when Fgfr4 is normally expressed. By 7 days of regeneration, differentiation of myotubes became poorly coordinated and delayed by both histology and embryonic myosin heavy chain staining. By 14 days much of the muscle was replaced by fat and calcifications. To begin to dissect the molecular pathways involving Fgfr4, we queried the promoter sequences for transcriptional factor binding sites and tested candidate regulators in a 27-time point regeneration series. The Fgfr4 promoter region contained a Tead protein binding site (M-CAT 5'-CATTCCT-3'), and Tead2 showed induction during regeneration commensurate with Fgfr4 regulation. Co-transfection of Tead2 and Fgfr4 promoter reporter constructs into C2C12 myotubes showed Tead2 to activate Fgfr4, and mutation of the M-CAT motif in the Fgfr4 promoter abolished these effects. Immunostaining for Tead2 showed timed expression in myotube nuclei consistent with the mRNA data. Query of the expression timing and genomic sequences of Tead2 suggested direct regulation by MyoD, and consistent with this, MyoD directly bound to two strong E-boxes in the first intron of Tead2 by chromatin immunoprecipitation assay. Moreover, co-transfection of MyoD and Tead2 intron reporter constructs into 10T1/2 cells activated reporter activity in a dose-dependent manner. This activation was greatly reduced when the two E-boxes were mutated. Our data suggest a novel MyoD-Tead2-Fgfr4 pathway important for effective muscle regeneration.

  5. Catheter dysfunction and dialysis performance according to vascular access among 736 critically ill adults requiring renal replacement therapy: a randomized controlled study.

    Science.gov (United States)

    Parienti, Jean-Jacques; Mégarbane, Bruno; Fischer, Marc-Olivier; Lautrette, Alexandre; Gazui, Nicole; Marin, Nathalie; Hanouz, Jean-Luc; Ramakers, Michel; Daubin, Cédric; Mira, Jean-Paul; Charbonneau, Pierre; du Cheyron, Damien

    2010-04-01

    To compare dialysis catheter function according to catheter site. Multicenter, open, randomized controlled trial. Nine university-affiliated hospitals and three general hospitals in France. Seven hundred thirty-six patients in intensive care units who required a first venous catheterization to perform either intermittent hemodialysis (470 patients with 1275 sessions) or continuous renal replacement therapy (266 patients with 1003 days). Patients randomly received either femoral (n = 370) or jugular (n = 366) catheterization. For the jugular site, right-side position (n = 252) was recommended. Time to catheter ablation for dysfunction, urea reduction ratio (intermittent hemodialysis), and downtime (continuous renal replacement therapy) were assessed for all participants and evaluated by randomly assigned catheterization site (femoral or jugular). Baseline demography and dialysis prescriptions were similar between the site arms. In modified intent-to-treat, catheter dysfunction occurred in 36 of 348 (10.3%) and 38 of 342 (11.1%) patients in the femoral and jugular groups, respectively. The risk of catheter dysfunction did not significantly differ between randomized groups (hazard ratio, 1.06; 95% confidence interval, 0.67-1.68; p = .80). Compared to the femoral site, the observed risk of dysfunction decreased in the right jugular position (15 of 226; 6.6%; adjusted hazard ratio, 0.58; 95% confidence interval, 0.31-1.07; p = .09) and significantly increased in the left jugular position (23 of 118; 19.5%; adjusted hazard ratio, 1.89; 95% confidence interval, 1.12-3.21; p hemodialysis mean urea reduction ratio per session was 50.8% (standard deviation, 16.1) for femoral vs. 52.8% (standard deviation, 15.8) for jugular (p = .30) sites, and the median continuous renal replacement therapy downtime per patient-day was 1.17 hrs (interquartile range, 0.75-1.50) for both sites (p = .98). In terms of catheter dysfunction and dialysis performance among critically ill adults

  6. Impact of CYP3A4 and MDR1 gene (G2677T) polymorphisms on dose requirement of the cyclosporine in renal transplant Egyptian recipients.

    Science.gov (United States)

    Sharaki, Ola; Zeid, Montasser; Moez, Pacint; Zakaria, Nermine Hossam; Nassar, Eman

    2015-01-01

    Advances in immunosuppressive therapy allowed renal transplantation to become the treatment of choice for suitable candidates with (end stage renal disease) ESRD. The post-transplant therapeutic strategy is difficult due to narrow therapeutic indices for the currently used immunosuppressive drugs. Inter-individual differences in drug bioavailability are related to genetic and non genetic factors. The idea of targeted and personalized therapy is to achieve therapeutic success. The empirical dose has lost its value in the post-transplant therapy and an individualized dosage regimen must be established. Interindividual heterogeneity in expression of ABCB1 and CYP3A4 has been suspected to be one of the factors resulting in cyclosporine (CsA) pharmacokinetic variation. This study aimed to investigate the impact of inter-individual CYP3A4 rs4646437C>T and MDR1 G2677T/A polymorphisms on cyclosporine dose requirements among a sample of renal transplant Egyptian recipients. Fifty adult Egyptian patients on CsA were genotyped for CYP3A4 rs4646437C>T and MDR1 G2677T/A and correlated with CsA dose requirement and dose-adjusted CsA (C0) blood levels at 3, 6, and 9 months post transplantation. CYP3A4 rs4646437C>T influenced significantly cyclosporine kinetics, the T carriers requiring higher cyclosporine dose. Daily dose requirements were also significantly higher in T allele MDR1 2677G>T GG genotype as compared to GT/TT genotypes at 3, 6, and 9 months post transplantation. Genotyping of both CYP3A4 and MDR1 SNPs may be helpful in providing pre-transplant pharmacogenetic information to individualize CsA dosing. Heterozygous CT genotype is the most frequent CYP3A4 rs4646437C>T genotype in the studied group of Egyptian population (48 %) followed by CC genotype and TT genotype. Daily dose requirements were significantly higher in T allele MDR1 2677G>T GG genotype as compared to GT/TT genotypes at 3, 6, and 9 months post transplantation.

  7. [Periodontitis and tissue regeneration].

    Science.gov (United States)

    Yamazaki, Kazuhisa

    2005-08-01

    Chronic periodontitis is a destructive disease that affects the supporting structures of the teeth including periodontal ligament, cementum, and alveolar bone. If left untreated, patients may lose multiple teeth and extensive prosthetic treatment will be required. In order to re-engineer lost tooth-supporting tissues, various therapeutic modalities have been used clinically. Periodontal regeneration procedures including guided tissue regeneration have achieved substantial effects. However, there are several issues to be solved. They are highly technique-sensitive, applicable to limited cases which are susceptible to treatment, and supposed to have relatively low predictability. Therefore, it is necessary to develop new approaches to improve the predictability and effectiveness of regenerative therapies for periodontal tissues. Recently, the concept of tissue engineering has been introduced to restore lost tissues more effectively where the biological process of healing is mimicked. To achieve this, integration of three key elements is required: progenitor/stem cells, growth factors and the extracellular matrix scaffold. Although it has been shown that implantation of bone marrow-derived mesenchymal stem cells into periodontal osseous defects induced regeneration of cementum, periodontal ligament and alveolar bone in dogs, further extensive preclinical studies are required. On the other hand, application of growth factors, particularly basic fibroblast growth factor in the treatment of human periodontitis, is promising and is now in clinical trial. Furthermore, the rate of release of growth factor from the scaffold also can profoundly affect the results of tissue engineering strategies and the development of new materials is expected. In addition, as tissue regenerative potential is negatively regulated by aging, the effects of aging have to be clarified to gain complete regeneration.

  8. Massive fluid requirements and an unusual BUN/creatinine ratio for pre-renal failure in patients with cholera.

    Directory of Open Access Journals (Sweden)

    Muhammad Tariq

    Full Text Available BACKGROUND: Cholera is an important infectious cause of secretory diarrhea. The primary symptom of infection is the sudden onset of watery diarrhea with subsequent volume depletion causing renal insufficiency. The objective of this research is to study the level of dehydration at presentation and subsequent fluid management in patients with cholera. METHODS: This study was conducted on 191 patients of Cholera admitted at a tertiary care hospital in Karachi, Pakistan during the period of 5 years. Medical charts were evaluated retrospectively for initial hydration status, baseline lab investigations on admission and discharge and fluid therapy given to all the patients while their stay in the hospital and the data was analyzed on SPSS 15.0. RESULTS: Out of the 191 patients, 83(43% were males and 108 (57% were females with mean age of 42.3 years (SD+/-18.34. The average duration of symptoms was 3.75 days (SD+/-2.04. Of 191 patients, 175 (92.1% presented with dehydration, 80 (42.3% were given Ringer's Lactate (R/L + Normal Saline (N/S, 45 (24% patients were given R/L + N/S + Oral Rehydration Therapy (ORS, 27 (14.3% of the patients were kept on R/L only and remaining were given various combinations of R/L, N/S, ORS and Dextrose Saline (D/S. On admission mean Blood Urea Nitrogen (BUN was 24.54 (SD+/-16.6, mean creatinine was 2.47 (SD+/-2.35 and mean BUN/Creatinine ratio was 11.63 (SD+/-5.7. CONCLUSION: Aggressive fluid rehydration remains the cornerstone of management of cholera. Instead of presenting with a classical BUN/Creatinine ratio of >20:1, patients with pre-renal failure in cholera may present with a BUN/Creatinine ratio of <15:1.

  9. Regenerator seal

    Science.gov (United States)

    Davis, Leonard C.; Pacala, Theodore; Sippel, George R.

    1981-01-01

    A method for manufacturing a hot side regenerator cross arm seal assembly having a thermally stablilized wear coating with a substantially flat wear surface thereon to seal between low pressure and high pressure passages to and from the hot inboard side of a rotary regenerator matrix includes the steps of forming a flat cross arm substrate member of high nickel alloy steel; fixedly securing the side edges of the substrate member to a holding fixture with a concave surface thereacross to maintain the substrate member to a slightly bent configuration on the fixture surface between the opposite ends of the substrate member to produce prestress therein; applying coating layers on the substrate member including a wear coating of plasma sprayed nickel oxide/calcium flouride material to define a wear surface of slightly concave form across the restrained substrate member between the free ends thereon; and thereafter subjecting the substrate member and the coating thereon to a heat treatment of 1600.degree. F. for sixteen hours to produce heat stabilizing growth in the coating layers on the substrate member and to produce a thermally induced growth stress in the wear surface that substantially equalizes the prestress in the substrate whereby when the cross arm is removed from the fixture surface following the heat treatment step a wear face is formed on the cross arm assembly that will be substantially flat between the ends.

  10. Bionanomaterials for skin regeneration

    CERN Document Server

    Leonida, Mihaela D

    2016-01-01

    This book gives a concise overview of bionanomaterials with applications for skin regeneration. The advantages and challenges of nanoscale materials are covered in detail, giving a basic view of the skin structure and conditions that require transdermal or topical applications. Medical applications, such as wound healing, care for burns, skin disease, and cosmetic care, such as aging of the skin and photodamage, and how they benefit from bionanomaterials, are described in detail. A final chapter is devoted to the ethical and social issues related to the use of bionanomaterials for skin regeneration. This is an ideal book for researchers in materials science, medical scientists specialized in dermatology, and cosmetic chemists working in formulations. It can also serve as a reference for nanotechnologists, dermatologists, microbiologists, engineers, and polymer chemists, as well as students studying in these fields.

  11. Mechanisms of platelet-mediated liver regeneration.

    Science.gov (United States)

    Lisman, Ton; Porte, Robert J

    2016-08-04

    Platelets have multiple functions beyond their roles in thrombosis and hemostasis. Platelets support liver regeneration, which is required after partial hepatectomy and acute or chronic liver injury. Although it is widely assumed that platelets stimulate liver regeneration by local excretion of mitogens stored within platelet granules, definitive evidence for this is lacking, and alternative mechanisms deserve consideration. In-depth knowledge of mechanisms of platelet-mediated liver regeneration may lead to new therapeutic strategies to treat patients with failing regenerative responses.

  12. Dicer-dependent production of microRNA221 in hepatocytes inhibits p27 and is required for liver regeneration in mice.

    Science.gov (United States)

    Oya, Yuki; Masuzaki, Ryota; Tsugawa, Daisuke; Ray, Kevin C; Dou, Yongchao; Karp, Seth J

    2017-05-01

    Dicer processes microRNAs (miRs) into active forms in a wide variety of tissues, including the liver. To determine the role of Dicer in liver regeneration, we performed a series of in vivo and in vitro studies in a murine 2/3 hepatectomy model. Dicer was downregulated after 2/3 hepatectomy, and loss of Dicer inhibited liver regeneration associated with decreased cyclin A2 and miR-221, as well as increased levels of the cell cycle inhibitor p27. In vitro, miR-221 inhibited p27 production in primary hepatocytes and increased hepatocyte proliferation. Specific reconstitution of miR-221 in hepatocyte-specific Dicer-null mice inhibited p27 and restored liver regeneration. In wild type mice, targeted inhibition of miR-221 using a cholesterol-conjugated miR-221 inhibited hepatocyte proliferation after 2/3 hepatectomy. These results identify Dicer production of miR-221 as an essential component of a miRNA-dependent mechanism for suppression of p27 that controls the rate of hepatocyte proliferation after partial hepatectomy.NEW & NOTEWORTHY Our findings demonstrate a direct role for microRNAs in controlling the rate of liver regeneration after injury. By deleting Dicer, an enzyme responsible for processing microRNAs into mature forms, we determined miR-221 is a critical microRNA in the physiological process of restoration of liver mass after injury. miR-221 suppresses p27, releasing its inhibitory effects on hepatocyte proliferation. Pharmaceuticals based on miR-221 may be useful to modulate hepatocyte proliferation in the setting of liver injury. Copyright © 2017 the American Physiological Society.

  13. A regulatory program for excretory system regeneration in planarians

    OpenAIRE

    Scimone, M Lucila; Srivastava, Mansi; Bell, George W.; Reddien, Peter W.

    2011-01-01

    Planarians can regenerate any missing body part, requiring mechanisms for the production of organ systems in the adult, including their prominent tubule-based filtration excretory system called protonephridia. Here, we identify a set of genes, Six1/2-2, POU2/3, hunchback, Eya and Sall, that encode transcription regulatory proteins that are required for planarian protonephridia regeneration. During regeneration, planarian stem cells are induced to form a cell population in regeneration blastem...

  14. Amino Acid requirements in critically ill patients with acute kidney injury treated with continuous renal replacement therapy.

    Science.gov (United States)

    Btaiche, Imad F; Mohammad, Rima A; Alaniz, Cesar; Mueller, Bruce A

    2008-05-01

    Acute kidney injury in critically ill patients is often a complication of an underlying condition such as organ failure, sepsis, or drug therapy. In these patients, stress-induced hypercatabolism results in loss of body cell mass. Unless nutrition support is provided, malnutrition and negative nitrogen balance may ensue. Because of metabolic, fluid, and electrolyte abnormalities, optimization of nutrition to patients with acute kidney injury presents a challenge to the clinician. In patients treated with conventional intermittent hemodialysis, achieving adequate amino acid intake can be limited by azotemia and fluid restriction. With the use of continuous renal replacement therapy (CRRT), however, better control of azotemia and liberalization of fluid intake allow amino acid intake to be maximized to support the patient's metabolic needs. High amino acid doses up to 2.5 g/kg/day in patients treated with CRRT improved nitrogen balance. However, to our knowledge, no studies have correlated increased amino acid intake with improved outcomes in critically ill patients with acute kidney injury. Data from large, prospective, randomized, controlled trials are needed to optimize the dosing of amino acids in critically ill patients with acute kidney injury who are treated with CRRT and to study the safety of high doses and their effects on patient morbidity and survival.

  15. Renal replacement therapy for acute renal failure.

    Science.gov (United States)

    Macedo, E; Bouchard, J; Mehta, R L

    2009-09-01

    Renal replacement therapy became a common clinical tool to treat patients with severe acute kidney injury (AKI) since the 1960s. During this time dialytic options have expanded considerably; biocompatible membranes, bicarbonate dialysate and dialysis machines with volumetric ultrafiltration control have improved the treatment for acute kidney injury. Along with advances in methods of intermittent hemodialysis, continuous renal replacement therapies have gained widespread acceptance in the treatment of dialysis-requiring AKI. However, many of the fundamental aspects of the renal replacement treatment such as indication, timing of dialytic intervention, and choice of dialysis modality are still controversial and may influence AKI patient's outcomes. This review outlines current concepts in the use of dialysis techniques for AKI and suggests an approach for selecting the optimal method of renal replacement therapy.

  16. Renal Osteodystrophy

    Directory of Open Access Journals (Sweden)

    Aynur Metin Terzibaşoğlu

    2004-12-01

    Full Text Available Chronic renal insufficiency is a functional definition which is characterized by irreversible and progressive decreasing in renal functions. This impairment is in collaboration with glomeruler filtration rate and serum creatinine levels. Besides this, different grades of bone metabolism disorders develop in chronic renal insufficiency. Pathologic changes in bone tissue due to loss of renal paranchyme is interrelated with calcium, phosphorus vitamine-D and parathyroid hormone. Clinically we can see high turnover bone disease, low turnover bone disease, osteomalacia, osteosclerosis and osteoporosis in renal osteodystropy. In this article we aimed to review pathology of bone metabolism disorders due to chronic renal insufficiency, clinic aspects and treatment approaches briefly.

  17. Mechanisms by which heme oxygenase rescue renal dysfunction in obesity

    Directory of Open Access Journals (Sweden)

    Joseph Fomusi Ndisang

    2014-01-01

    Collectively, these data suggest that hemin ameliorates nephropathy by potentiating the expression of proteins of repair/regeneration, abating oxidative/inflammatory mediators, reducing renal histo-pathological lesions, while enhancing nephrin, podocin, podocalyxin, CD2AP and creatinine clearance, with corresponding reduction of albuminuria/proteinuria suggesting improved renal function in hemin-treated ZFs. Importantly, the concomitant potentiation regeneration proteins and podocyte cytoskeletal proteins are novel mechanisms by which hemin rescue nephropathy in obesity.

  18. Music does not reduce alfentanil requirement during patient-controlled analgesia (PCA) use in extracorporeal shock wave lithotripsy for renal stones.

    Science.gov (United States)

    Cepeda, M S; Diaz, J E; Hernandez, V; Daza, E; Carr, D B

    1998-12-01

    To evaluate the impact of music on opioid requirements and pain levels during renal lithotripsy using alfentanil patient-controlled analgesia (PCA), we conducted a prospective, blinded, randomized controlled trial. Patients undergoing lithotripsy were instructed in PCA use and asked to rate their anxiety and select their preferred type of music. They were then premedicated with morphine and ketorolac and randomly allocated into two groups. Group 1 (n = 97) had music started 10 min before the procedure and maintained until 10 min after its conclusion. Group 2 (n = 96) had music begun at the conclusion of lithotripsy and continued for 10 min. Pain intensity, alfentanil requirement, side effects, quality of analgesia, patient satisfaction, and acceptance of the technique were evaluated. Demographics, alfentanil requirement, pain levels, side effects, quality of analgesia, and patient satisfaction were similar in both groups. The addition of music did not provide any benefit. This result raises the possibility that some nonpharmacologic therapies have minimal impact in settings where the painful stimulus is moderate to severe and adequate pharmacotherapy is available.

  19. Renal tuberculosis

    Directory of Open Access Journals (Sweden)

    Džamić Zoran

    2016-01-01

    Full Text Available Tuberculosis is still a significant health problem in the world, mostly in developing countries. The special significance lies in immunocompromised patients, particularly those suffering from the HIV. Urogenital tuberculosis is one of the most common forms of extrapulmonary tuberculosis, while the most commonly involved organ is the kidney. Renal tuberculosis occurs by hematogenous dissemination of mycobacterium tuberculosis from a primary tuberculosis foci in the body. Tuberculosis is characterized by the formation of pathognomonic lesions in the tissues - granulomata. These granulomata may heal spontaneously or remain stable for years. In certain circumstances in the body associated with immunosuppression, the disease may be activated. Central caseous necrosis occurs within tuberculoma, leading to formation of cavities that destroy renal parenchyma. The process may gain access to the collecting system, forming the caverns. In this way, infection can be spread distally to renal pelvis, ureter and bladder. Scaring of tissue by tuberculosis process may lead to development of strictures of the urinary tract. The clinical manifestations are presented by nonspecific symptoms and signs, so tuberculosis can often be overlooked. Sterile pyuria is characteristic for urinary tuberculosis. Dysuric complaints, flank pain or hematuria may be presented in patients. Constitutional symptoms of fever, weight loss and night sweats are presented in some severe cases. Diagnosis is made by isolation of mycobacterium tuberculosis in urine samples, by cultures carried out on standard solid media optimized for mycobacterial growth. Different imaging studies are used in diagnostics - IVU, CT and NMR are the most important. Medical therapy is the main modality of tuberculosis treatment. The first line anti-tuberculosis drugs include isoniazid, rifampicin, pyrazinamide and ethambutol. Surgical treatment is required in some cases, to remove severely damaged kidney, if

  20. Phosphatase of regenerating liver-3 localizes to cyto-membrane and is required for B16F1 melanoma cell metastasis in vitro and in vivo.

    Directory of Open Access Journals (Sweden)

    Ran Song

    Full Text Available BACKGROUND: Phosphatase of regenerating liver-3 (PRL-3 is a member of the novel phosphatases of regenerating liver family, characterized by one protein tyrosine phosphatase active domain and a C-terminal prenylation (CCVM motif. Though widely proposed to facilitate metastasis in many cancer types, PRL-3's cellular localization and the function of its CCVM motif in metastatic process remain unknown. METHODOLOGY/PRINCIPAL FINDINGS: In the present study, a series of Myc tagged PRL-3 wild type or mutant plasmids were expressed in B16F1 melanoma cells to investigate the relationship between PRL-3's cellular localization and metastasis. With immuno-fluorescence microcopy and cell adhesion/migration assay in vitro, and an experimental passive metastasis model in vivo, we found that CCVM motif is critical for the localization of PRL-3 on cell plasma membrane and the lung metastasis of melanoma. In particular, Cystine170 is the key site for prenylation in this process. CONCLUSIONS/SIGNIFICANCE: These results suggest that cellular localization of PRL-3 is highly correlated with its function in tumor metastasis, and inhibition of PRL-3 prenylation might be a new approach to cancer therapy.

  1. Renal Impairment with Sublethal Tubular Cell Injury in a Chronic Liver Disease Mouse Model.

    Science.gov (United States)

    Ishida, Tokiko; Kotani, Hirokazu; Miyao, Masashi; Kawai, Chihiro; Jemail, Leila; Abiru, Hitoshi; Tamaki, Keiji

    2016-01-01

    The pathogenesis of renal impairment in chronic liver diseases (CLDs) has been primarily studied in the advanced stages of hepatic injury. Meanwhile, the pathology of renal impairment in the early phase of CLDs is poorly understood, and animal models to elucidate its mechanisms are needed. Thus, we investigated whether an existing mouse model of CLD induced by 3,5-diethoxycarbonyl-1,4-dihydrocollidine (DDC) shows renal impairment in the early phase. Renal injury markers, renal histology (including immunohistochemistry for tubular injury markers and transmission electron microscopy), autophagy, and oxidative stress were studied longitudinally in DDC- and standard diet-fed BALB/c mice. Slight but significant renal dysfunction was evident in DDC-fed mice from the early phase. Meanwhile, histological examinations of the kidneys with routine light microscopy did not show definitive morphological findings, and electron microscopic analyses were required to detect limited injuries such as loss of brush border microvilli and mitochondrial deformities. Limited injuries have been recently designated as sublethal tubular cell injury. As humans with renal impairment, either with or without CLD, often show almost normal tubules, sublethal injury has been of particular interest. In this study, the injuries were associated with mitochondrial aberrations and oxidative stress, a possible mechanism for sublethal injury. Intriguingly, two defense mechanisms were associated with this injury that prevent it from progressing to apparent cell death: autophagy and single-cell extrusion with regeneration. Furthermore, the renal impairment of this model progressed to chronic kidney disease with interstitial fibrosis after long-term DDC feeding. These findings indicated that DDC induces renal impairment with sublethal tubular cell injury from the early phase, leading to chronic kidney disease. Importantly, this CLD mouse model could be useful for studying the pathophysiological mechanisms of

  2. Renal Impairment with Sublethal Tubular Cell Injury in a Chronic Liver Disease Mouse Model.

    Directory of Open Access Journals (Sweden)

    Tokiko Ishida

    Full Text Available The pathogenesis of renal impairment in chronic liver diseases (CLDs has been primarily studied in the advanced stages of hepatic injury. Meanwhile, the pathology of renal impairment in the early phase of CLDs is poorly understood, and animal models to elucidate its mechanisms are needed. Thus, we investigated whether an existing mouse model of CLD induced by 3,5-diethoxycarbonyl-1,4-dihydrocollidine (DDC shows renal impairment in the early phase. Renal injury markers, renal histology (including immunohistochemistry for tubular injury markers and transmission electron microscopy, autophagy, and oxidative stress were studied longitudinally in DDC- and standard diet-fed BALB/c mice. Slight but significant renal dysfunction was evident in DDC-fed mice from the early phase. Meanwhile, histological examinations of the kidneys with routine light microscopy did not show definitive morphological findings, and electron microscopic analyses were required to detect limited injuries such as loss of brush border microvilli and mitochondrial deformities. Limited injuries have been recently designated as sublethal tubular cell injury. As humans with renal impairment, either with or without CLD, often show almost normal tubules, sublethal injury has been of particular interest. In this study, the injuries were associated with mitochondrial aberrations and oxidative stress, a possible mechanism for sublethal injury. Intriguingly, two defense mechanisms were associated with this injury that prevent it from progressing to apparent cell death: autophagy and single-cell extrusion with regeneration. Furthermore, the renal impairment of this model progressed to chronic kidney disease with interstitial fibrosis after long-term DDC feeding. These findings indicated that DDC induces renal impairment with sublethal tubular cell injury from the early phase, leading to chronic kidney disease. Importantly, this CLD mouse model could be useful for studying the

  3. Comparison of heparin to citrate as a catheter locking solution for non-tunneled central venous hemodialysis catheters in patients requiring renal replacement therapy for acute renal failure (VERROU-REA study): study protocol for a randomized controlled trial.

    Science.gov (United States)

    Bruyère, Rémi; Soudry-Faure, Agnès; Capellier, Gilles; Binquet, Christine; Nadji, Abdelouaid; Torner, Stephane; Blasco, Gilles; Yannaraki, Maria; Barbar, Saber Davide; Quenot, Jean-Pierre

    2014-11-19

    The incidence of acute kidney injury (AKI) is estimated at 10 to 20% in patients admitted to intensive care units (ICU) and often requires renal replacement therapy (RRT). ICU mortality in AKI patients can exceed 50%. Venous catheters are the preferred vascular access method for AKI patients requiring RRT, but carry a risk of catheter thrombosis or infection. Catheter lock solutions are commonly used to prevent such complications. Heparin and citrate locks are both widely used for tunneled, long-term catheters, but few studies have compared citrate versus heparin for patients with short-term, non-tunneled catheters. We aim to compare citrate 4% catheter lock solution versus heparin in terms of event-free survival of the first non-tunneled hemodialysis catheter inserted in ICU patients with AKI requiring RRT. Secondary objectives are the rate of fibrinolysis, incidence of catheter thrombosis and catheter-related infection per 1,000 catheter days, length of stay in ICU and in-hospital and 28-day mortality. The VERROU-REA study is a randomized, prospective, multicenter, double-blind, parallel-group, controlled superiority study carried out in the medical, surgical and nephrological ICUs of two large university hospitals in eastern France. A catheter lock solution composed of trisodium citrate at 4% will be compared to unfractionated heparin at a concentration of 5,000 IU/mL. All consecutive adult patients with AKI requiring extracorporeal RRT, and in whom a first non-tunneled catheter is to be inserted by the jugular or femoral approach, will be eligible. Catheters inserted by the subclavian approach, patients with acute liver failure, thrombopenia or contraindication to systemic anticoagulation will be excluded. Patients will be followed up daily in accordance with standard practices for RRT until death or discharge. Data is scarce regarding the use of non-tunneled catheters in the ICU setting in patients with AKI. This study will provide an evidence base for

  4. Bone regeneration and stem cells

    DEFF Research Database (Denmark)

    Arvidson, K; Abdallah, B M; Applegate, L A

    2011-01-01

    cells, use of platelet rich plasma for tissue repair, osteogenesis and its molecular markers. A variety of cells in addition to stem cells, as well as advances in materials science to meet specific requirements for bone and soft tissue regeneration by addition of bioactive molecules, are discussed....

  5. A self-renewing division of zebrafish Müller glial cells generates neuronal progenitors that require N-cadherin to regenerate retinal neurons.

    Science.gov (United States)

    Nagashima, Mikiko; Barthel, Linda K; Raymond, Pamela A

    2013-11-01

    Müller glia function as retinal stem cells in adult zebrafish. In response to loss of retinal neurons, Müller glia partially dedifferentiate, re-express neuroepithelial markers and re-enter the cell cycle. We show that the immunoglobulin superfamily adhesion molecule Alcama is a novel marker of multipotent retinal stem cells, including injury-induced Müller glia, and that each Müller glial cell divides asymmetrically only once to produce an Alcama-negative, proliferating retinal progenitor. The initial mitotic division of Müller glia involves interkinetic nuclear migration, but mitosis of retinal progenitors occurs in situ. Rapidly dividing retinal progenitors form neurogenic clusters tightly associated with Alcama/N-cadherin-labeled Müller glial radial processes. Genetic suppression of N-cadherin function interferes with basal migration of retinal progenitors and subsequent regeneration of HuC/D(+) inner retinal neurons.

  6. Renal perfusion scintiscan

    Science.gov (United States)

    Renal perfusion scintigraphy; Radionuclide renal perfusion scan; Perfusion scintiscan - renal; Scintiscan - renal perfusion ... supply the kidneys. This is a condition called renal artery stenosis. Significant renal artery stenosis may be ...

  7. Active magnetic regenerator

    Science.gov (United States)

    Barclay, John A.; Steyert, William A.

    1982-01-01

    The disclosure is directed to an active magnetic regenerator apparatus and method. Brayton, Stirling, Ericsson, and Carnot cycles and the like may be utilized in an active magnetic regenerator to provide efficient refrigeration over relatively large temperature ranges.

  8. Helping the Retina Regenerate

    Science.gov (United States)

    ... Briefs > Helping the retina regenerate Helping the retina regenerate NEI Audacious Goals Initiative report outlines strategies to replace or reprogram neurons in the retina News Brief 03/30/17 ...

  9. Reintegration of the regenerated and the remaining tissues during joint regeneration in the newt Cynops pyrrhogaster.

    Science.gov (United States)

    Tsutsumi, Rio; Inoue, Takeshi; Yamada, Shigehito; Agata, Kiyokazu

    2015-02-01

    Urodele amphibians, such as newts, can regenerate a functional limb, including joints, after amputation at any level along the proximal-distal axis of the limb. The blastema can regenerate the limb morphology largely independently of the stump after proximal-distal identity has been established, but the remaining and regenerated tissues must be structurally reintegrated (matched in size and shape). Here we used newt joint regeneration as a model to investigate reintegration, because a functionally interlocking joint requires structural integration between its opposing skeletal elements. After forelimbs were amputated at the elbow joint, the joint was regenerated between the remaining and regenerated skeletal elements. The regenerated cartilage was thick around the amputated joint to make a reciprocally interlocking joint structure with the remaining bone. Furthermore, during regeneration, the extracellular matrix of the remaining tissues was lost, suggesting that the remaining tissues might contribute to the morphogenesis of regenerating cartilage. Our results showed that the area of the regenerated cartilage matched the area of the apposed remaining cartilage, thus contributing to formation of a functional structure.

  10. Renal neuroendocrine tumors

    Directory of Open Access Journals (Sweden)

    Brian R Lane

    2009-01-01

    Full Text Available Objectives: Neuroendocrine tumors (NETs are uncommon tumors that exhibit a wide range of neuroendocrine differentiation and biological behavior. Primary NETs of the kidney, including carcinoid tumor, small cell carcinoma (SCC, and large cell neuroendocrine carcinoma (LCNEC are exceedingly rare. Materials and Methods: The clinicopathologic features of renal NETs diagnosed at a single institution were reviewed along with all reported cases in the worldwide literature. Results: Eighty renal NETs have been described, including nine from our institution. Differentiation between renal NETs and the more common renal neoplasms (renal cell carcinoma, transitional cell carcinoma can be difficult since clinical, radiographic, and histopathologic features overlap. Immunohistochemical staining for neuroendocrine markers, such as synaptophysin and chromogranin, can be particularly helpful in this regard. Renal carcinoids are typically slow-growing, may secrete hormones, and pursue a variable clinical course. In contrast, SCC and LCNEC often present with locally advanced or metastatic disease and carry a poor prognosis. Nephrectomy can be curative for clinically localized NETs, but multimodality treatment is indicated for advanced disease. Conclusions: A spectrum of NETs can rarely occur in the kidney. Renal carcinoids have a variable clinical course; SCC and LCNEC are associated with poor clinical outcomes. Diagnosis of NETs, especially LCNEC, requires awareness of their rare occurrence and prudent use of immunohistochemical neuroendocrine markers.

  11. BMP signaling induces digit regeneration in neonatal mice.

    Science.gov (United States)

    Yu, Ling; Han, Manjong; Yan, Mingquan; Lee, Eun-Chee; Lee, Jangwoo; Muneoka, Ken

    2010-02-01

    The regenerating digit tip of mice is a novel epimorphic response in mammals that is similar to fingertip regeneration in humans. Both display restricted regenerative capabilities that are amputation-level dependent. Using this endogenous regeneration model in neonatal mice, we have found that noggin treatment inhibits regeneration, thus suggesting a bone morphogenetic protein (BMP) requirement. Using non-regenerating amputation wounds, we show that BMP7 or BMP2 can induce a regenerative response. BMP-induced regeneration involves the formation of a mammalian digit blastema. Unlike the endogenous regeneration response that involves redifferentiation by direct ossification (evolved regeneration), the BMP-induced response involves endochondral ossification (redevelopment). Our evidence suggests that BMP treatment triggers a reprogramming event that re-initiates digit tip development at the amputation wound. These studies demonstrate for the first time that the postnatal mammalian digit has latent regenerative capabilities that can be induced by growth factor treatment.

  12. Nanobiomaterials for neural regeneration

    Institute of Scientific and Technical Information of China (English)

    Nuan Chen; Lingling Tian; Liumin He; Seeram Ramakrishna

    2016-01-01

    Diseases and disorders associated with nervous system such as injuries by trauma and neurodegeneration are shown to be one of the most serious problems in medicine, requiring innovative strategies to trigger and enhance the nerve regeneration. Tissue engineering aims to provide a highly biomimetic environment by using a combination of cells, materials and suitable biological cues, by which the lost body part may be regenerated or even fully rebuilt. Electrospinning, being able to produce extracellular matrix (ECM)-like nanostructures with great lfexibility in design and choice of materials, have demonstrated their great po-tential for fabrication of nerve tissue engineered scaffolds. The review here begins with a brief description of the anatomy of native nervous system, which provides basic knowledge and ideas for the design of nerve tissue scaffolds, followed by ifve main parts in the design of electrospun nerve tissue engineered scaffolds including materials selection, structural design,in vitro bioreactor, functionalization and cellular support. Performances of biomimetic electrospun nanofibrous nerve implant devices are also reviewed. Finally, future directions for advanced electrospun nerve tissue engineered scaffolds are discussed.

  13. OBSTETRIC RENAL FAILURE

    Directory of Open Access Journals (Sweden)

    Rajeshwari

    2015-11-01

    Full Text Available Renal failure in obstetrics is rare but important complication, associated with significant mortality and long term morbidity.1,2 It includes acute renal failure due to obstetrical complications or due to deterioration of existing renal disease. AIMS AND OBJECTIVES: To evaluate the etiology and outcome of renal failure in obstetric patients. METHODS: We prospectively analyzed 30 pregnant and puerperal women with acute renal failure or pre-existing renal disease developing renal failure during pregnancy between November 2007 to sep-2009. Patients who presented/developed ARF during the hospital stay were included in this study. RESULTS: Among 30 patients, mean age was 23 years and 33 years age group. 12 cases (40% patients were primigravidae and 9(30% patients were multigravidae and 9 cases (30% presented in post-partum period. Eighteen cases (60% with ARF were seen in third trimester, followed by in postpartum period 9 cases (30%. Most common contributing factors to ARF were Pre-eclampsia, eclampsia and HELLP syndrome 60%, sepsis 56.6%, post abortal ARF 10%. DIC 40%. Haemorrhage as the aetiology for ARF was present 46%, APH in 20% and PPH in 26.6%. The type of ARF was renal in (63% and prerenal (36%; Oliguric seen in 10 patients (33% and high mortality (30%. Among the 20 pregnant patients with ARF, The average period of gestation was 33±2 weeks (30 -36 weeks, 5 cases (25% presented with intrauterine fetal demise and 18 cases (66% had preterm vaginal delivery and 2 cases (10% had induced abortion. And the average birth weight was 2±0.5 kg (1.5 kg. Eight cases (26% required dialysis. 80% of patients recovered completely of renal functions. 63% patients recovered without renal replacement therapy whereas 17% required dialysis. the maternal mortality was 20%, the main reason for mortality was septic shock and multi organ dysfunction (66%. CONCLUSION: ARF related pregnancy was seen commonly in the primigravidae and in the third trimester, the most

  14. Repair and regeneration in endodontics.

    Science.gov (United States)

    Lin, L M; Rosenberg, P A

    2011-10-01

    The ideal objective of treatment of established diseases, including irreversible pulpitis and apical periodontitis, is to achieve wound healing. Wound healing can result in repair or regeneration. The ultimate goal of wound healing is to restore the original architecture and biological function of the injured tissue or organ. Although humans are equipped with powerful innate and adaptive immune defence mechanisms, many intrinsic and extrinsic factors can affect wound healing. Complete regeneration following injury in humans can occur only in the pre-natal foetus within 24 weeks of gestation. Post-natal wounds including irreversible pulpitis or apical periodontitis always heal by repair or by a combination of repair and regeneration. Somatic cells, such as fibroblasts, macrophages, cementoblasts and osteoblasts, in the pulp and periapical tissues have limited potential for regeneration following injury and lack of telomerase. Wound healing of irreversible pulpitis and apical periodontitis requires recruitment and differentiation of progenitor/stem cells into tissue-committed somatic cells. Stem cell differentiation is regulated by intrinsic factors and extrinsic micro-environmental cues. Functionality of stem cells appears to show an age-related decline because of the change in intrinsic properties and diminished signals within the extrinsic local and systemic environment that modulate the function of stem cells or their progeny. Infection induces an immuno-inflammatory response and tissue destruction, which hinders the potential of tissue regeneration. Therefore, prevention, early detection and treatment of inflammation/infection of pulpal and periapical disease can enhance regeneration and minimize the repair of pulpal and periapical tissues after endodontic therapy. © 2011 International Endodontic Journal.

  15. RENAL CRYOABLATION

    Directory of Open Access Journals (Sweden)

    A. V. Govorov

    2012-01-01

    Full Text Available Renal cryoablation is an alternative minimally-invasive method of treatment for localized renal cell carcinoma. The main advantages of this methodology include visualization of the tumor and the forming of "ice ball" in real time, fewer complications compared with other methods of treatment of renal cell carcinoma, as well as the possibility of conducting cryotherapy in patients with concomitant pathology. Compared with other ablative technologies cryoablation has a low rate of repeat sessions and good intermediate oncological results. The studies of long-term oncological and functional results of renal cryoablation are presently under way.

  16. Renal angiomyolipoma

    DEFF Research Database (Denmark)

    Holm-Nielsen, P; Sørensen, Flemming Brandt

    1988-01-01

    lesion. Three cases of renal angiomyolipoma, 2 of which underwent perfusion-fixation, were studied by electron microscopy to clarify the cellular composition of this lesion. In the smooth muscle cells abundant accumulation of glycogen was found, whereas the lipocytes disclosed normal ultrastructural......-specific vesicular structures. These findings suggest a secondary vascular damage, i.e. the thickened vessels may not be a primary, integral part of renal angiomyolipoma. Evidence of a common precursor cell of renal angiomyolipoma was not disclosed. It is concluded that renal angiomyolipoma is a hamartoma composed...

  17. Chronic renal disease in pregnancy.

    Science.gov (United States)

    Ramin, Susan M; Vidaeff, Alex C; Yeomans, Edward R; Gilstrap, Larry C

    2006-12-01

    The purpose of this review was to examine the impact of varying degrees of renal insufficiency on pregnancy outcome in women with chronic renal disease. Our search of the literature did not reveal any randomized clinical trials or meta-analyses. The available information is derived from opinion, reviews, retrospective series, and limited observational series. It appears that chronic renal disease in pregnancy is uncommon, occurring in 0.03-0.12% of all pregnancies from two U.S. population-based and registry studies. Maternal complications associated with chronic renal disease include preeclampsia, worsening renal function, preterm delivery, anemia, chronic hypertension, and cesarean delivery. The live birth rate in women with chronic renal disease ranges between 64% and 98% depending on the severity of renal insufficiency and presence of hypertension. Significant proteinuria may be an indicator of underlying renal insufficiency. Management of pregnant women with underlying renal disease should ideally entail a multidisciplinary approach at a tertiary center and include a maternal-fetal medicine specialist and a nephrologist. Such women should receive counseling regarding the pregnancy outcomes in association with maternal chronic renal disease and the effect of pregnancy on renal function, especially within the ensuing 5 years postpartum. These women will require frequent visits and monitoring of renal function during pregnancy. Women whose renal disease is further complicated by hypertension should be counseled regarding the increased risk of adverse outcome and need for blood pressure control. Some antihypertensives, especially angiotensin-converting enzyme inhibitors and angiotensin-receptor blockers, should be avoided during pregnancy, if possible, because of the potential for both teratogenic (hypocalvaria) and fetal effects (renal failure, oliguria, and demise).

  18. Regeneration of periodontal tissues: guided tissue regeneration.

    Science.gov (United States)

    Villar, Cristina C; Cochran, David L

    2010-01-01

    The concept that only fibroblasts from the periodontal ligament or undifferentiated mesenchymal cells have the potential to re-create the original periodontal attachment has been long recognized. Based on this concept, guided tissue regeneration has been applied with variable success to regenerate periodontal defects. Quantitative analysis of clinical outcomes after guided tissue regeneration suggests that this therapy is a successful and predictable procedure to treat narrow intrabony defects and class II mandibular furcations, but offers limited benefits in the treatment of other types of periodontal defects.

  19. Renal cancer

    NARCIS (Netherlands)

    Corgna, Enrichetta; Betti, Maura; Gatta, Gemma; Roila, Fausto; De Mulder, Pieter H. M.

    2007-01-01

    In Europe, renal cancer (that is neoplasia of the kidney, renal pelvis or ureter (ICD-9 189 and ICD-10 C64-C66)) ranks as the seventh most common malignancy in men amongst whom there are 29,600 new cases each year (3.5% of all cancers). Tobacco, obesity and a diet poor in vegetables are all acknowle

  20. Renal fallure

    Institute of Scientific and Technical Information of China (English)

    1992-01-01

    920705 Endothelin and acute renal failure:study on their relationship and possiblemechanisms. LIN Shanyan(林善锬), et al.Renal Res Lab, Huashan Hosp, Shanghai MedUniv, Shanghai, 200040. Natl Med J China 1992;72(4): 201-205. In order to investigate the role of endothelin

  1. Renal cancer.

    NARCIS (Netherlands)

    Corgna, E.; Betti, M.; Gatta, G.; Roila, F.; Mulder, P.H.M. de

    2007-01-01

    In Europe, renal cancer (that is neoplasia of the kidney, renal pelvis or ureter (ICD-9 189 and ICD-10 C64-C66)) ranks as the seventh most common malignancy in men amongst whom there are 29,600 new cases each year (3.5% of all cancers). Tobacco, obesity and a diet poor in vegetables are all

  2. Renal cancer

    NARCIS (Netherlands)

    Corgna, Enrichetta; Betti, Maura; Gatta, Gemma; Roila, Fausto; De Mulder, Pieter H. M.

    2007-01-01

    In Europe, renal cancer (that is neoplasia of the kidney, renal pelvis or ureter (ICD-9 189 and ICD-10 C64-C66)) ranks as the seventh most common malignancy in men amongst whom there are 29,600 new cases each year (3.5% of all cancers). Tobacco, obesity and a diet poor in vegetables are all

  3. Notch Signaling Inhibits Axon Regeneration

    OpenAIRE

    Bejjani, Rachid El; Hammarlund, Marc

    2012-01-01

    Many neurons have limited capacity to regenerate their axons after injury. Neurons in the mammalian CNS do not regenerate, and even neurons in the PNS often fail to regenerate to their former targets. This failure is likely due in part to pathways that actively restrict regeneration; however, only a few factors that limit regeneration are known. Here, using single-neuron analysis of regeneration in vivo, we show that Notch/lin-12 signaling inhibits the regeneration of mature C. elegans neuron...

  4. Distinct Wnt signaling pathways have opposing roles in appendage regeneration.

    Science.gov (United States)

    Stoick-Cooper, Cristi L; Weidinger, Gilbert; Riehle, Kimberly J; Hubbert, Charlotte; Major, Michael B; Fausto, Nelson; Moon, Randall T

    2007-02-01

    In contrast to mammals, lower vertebrates have a remarkable capacity to regenerate complex structures damaged by injury or disease. This process, termed epimorphic regeneration, involves progenitor cells created through the reprogramming of differentiated cells or through the activation of resident stem cells. Wnt/beta-catenin signaling regulates progenitor cell fate and proliferation during embryonic development and stem cell function in adults, but its functional involvement in epimorphic regeneration has not been addressed. Using transgenic fish lines, we show that Wnt/beta-catenin signaling is activated in the regenerating zebrafish tail fin and is required for formation and subsequent proliferation of the progenitor cells of the blastema. Wnt/beta-catenin signaling appears to act upstream of FGF signaling, which has recently been found to be essential for fin regeneration. Intriguingly, increased Wnt/beta-catenin signaling is sufficient to augment regeneration, as tail fins regenerate faster in fish heterozygous for a loss-of-function mutation in axin1, a negative regulator of the pathway. Likewise, activation of Wnt/beta-catenin signaling by overexpression of wnt8 increases proliferation of progenitor cells in the regenerating fin. By contrast, overexpression of wnt5b (pipetail) reduces expression of Wnt/beta-catenin target genes, impairs proliferation of progenitors and inhibits fin regeneration. Importantly, fin regeneration is accelerated in wnt5b mutant fish. These data suggest that Wnt/beta-catenin signaling promotes regeneration, whereas a distinct pathway activated by wnt5b acts in a negative-feedback loop to limit regeneration.

  5. Meropenem dosing requirements against Enterobacteriaceae in critically ill patients: influence of renal function, geographical area and presence of extended-spectrum β-lactamases.

    Science.gov (United States)

    Isla, A; Canut, A; Arribas, J; Asín-Prieto, E; Rodríguez-Gascón, A

    2016-03-01

    The aim of this study was the evaluation of the influence of the susceptibility patterns of Escherichia coli and Klebsiella pneumoniae isolates, specifically the presence of extended-spectrum β-lactamases and the geographical area (Europe and USA), on the meropenem dosing requirements in critically ill patients with different degrees of renal function by estimation of the probability of pharmacokinetic/pharmacodynamic (PK/PD) target attainment. Additionally, estimation of the PK/PD breakpoints according to the European Committee on Antimicrobial Susceptibility Testing (EUCAST) approach was also an objective. Six dosing regimens were evaluated: 0.5 g, 1 g and 2 g every 8 h given as 0.5-h or 3-h infusions. Pharmacokinetic data were obtained from the literature, and susceptibility data to meropenem for E. coli and K. pneumoniae were collected from the Tigecycline Evaluation and Surveillance Trial (T.E.S.T.) surveillance study. For the same dose level, the 3-h infusion provided a probability of target attainment (PTA) ≥90 % for minimum inhibitory concentration (MIC) values up to two-fold dilution higher than those obtained with the 0.5-h infusion. For E. coli, the cumulative fraction of response (CFR) was 100 % in most cases, and neither the dose nor the infusion length nor the geographical area significantly affected the probability to reach the target. With regards to K. pneumoniae, the CFR increased when increasing the dose and decreasing the creatinine clearance (CLCR). The CFR for Spanish and USA strains was higher than that calculated for European strains. Meropenem PK/PD breakpoints are dependent on the dose, infusion length and CLCR, ranging from 2 to 32 mg/L. Based on our results, meropenem administered as a extended infusion is the best option to treat infections due to E. coli and K. pneumoniae.

  6. DIAGNOSTICS AND REGENERATION OF COMMON RAIL INJECTORS

    Directory of Open Access Journals (Sweden)

    Łukasz KONIECZNY

    2015-03-01

    Full Text Available The article presents the methodology of Common Rail injector diagnostic, regeneration and regulation with use of professional test stands. The EPS 815 machine can be used to test and repair all BOSCH injectors fully satisfying the producer requirements and standards. The article describes an example injector diagnosis with use of such test stand and additionally presents appropriate injector regeneration and encoding techniques

  7. Stirling convertor regenerators

    CERN Document Server

    Ibrahim, Mounir B

    2011-01-01

    Stirling Convertor Regenerators addresses the latest developments and future possibilities in the science and practical application of Stirling engine regenerators and technology. Written by experts in the vanguard of alternative energy, this invaluable resource presents integral scientific details and design concepts associated with Stirling converter regenerators. Content is reinforced with novel insights and remarkable firsthand experience that the authors and their colleagues acquired while working at the National Aeronautics and Space Administration (NASA) and other leading organizations.

  8. Renal failure in patients with multiple myeloma.

    Science.gov (United States)

    Almueilo, Samir H

    2015-01-01

    Renal dysfunction is encountered in 20-25% of patients with multiple myeloma (MM) at the time of diagnosis. There is often a precipitating event. Several biochemical and clinical correlations with renal failure in MM have been reported. Renal failure in MM is associated with worse outcome of the disease. We retrospectively analyzed the medical records of 64 patients with MM admitted to our institution during the period January 1992 to December 2012. Abnormal renal function was observed in 24 (37.5%) patients and 17 (26.6%) of them had renal failure; 14 of the 17 (82.4%) of patients with renal failure had Stage III MM. Urine Bence- Jones protein was positive in ten (58.8%) patients with renal failure versus ten (21.3%) patients without renal failure (P = 0.004). Potential precipitating factors of renal failure were determined in nine patients. Renal function normalized in 11 patients with simple measures, while six patients required hemodialysis; one remained dialysis dependent till time of death. Early mortality occurred in five (29.4%) patients with renal failure as compared with two (4.3%) patients in the group without renal failure (P = 0.005). In conclusion, renal failure is associated with a higher tumor burden and Bence-Jones proteinuria in patients with MM. It is reversible in the majority of patients; however, early mortality tends to be higher in patients with persistent renal failure.

  9. A histone demethylase is necessary for regeneration in zebrafish.

    Science.gov (United States)

    Stewart, Scott; Tsun, Zhi-Yang; Izpisua Belmonte, Juan Carlos

    2009-11-24

    Urodele amphibians and teleost fish regenerate amputated body parts via a process called epimorphic regeneration. A hallmark of this phenomenon is the reactivation of silenced developmental regulatory genes that previously functioned during embryonic patterning. We demonstrate that histone modifications silence promoters of numerous genes involved in zebrafish caudal fin regeneration. Silenced developmental regulatory genes contain bivalent me(3)K4/me(3)K27 H3 histone modifications created by the concerted action of Polycomb (PcG) and Trithorax histone methyltransferases. During regeneration, this silent, bivalent chromatin is converted to an active state by loss of repressive me(3)K27 H3 modifications, occurring at numerous genes that appear to function during regeneration. Loss-of-function studies demonstrate a requirement for a me(3)K27 H3 demethylase during fin regeneration. These results indicate that histone modifications at discreet genomic positions may serve as a crucial regulatory event in the initiation of fin regeneration.

  10. Ciprofloxacin-Induced Renal Failure

    Directory of Open Access Journals (Sweden)

    Audra Fuller

    2015-10-01

    Full Text Available Acute renal failure (ARF is a common diagnosis in hospitalized patients, particularly in intensive care units (ICU. Determining the cause and contributing factors associated with ARF is crucial during treatment. The etiology is complex, and several factors often contribute to its development. Medications can cause acute tubular necrosis, acute interstitial nephritis, and crystal-induced or post-obstructive nephropathy. There have been several case reports of ARF secondary to fluoroquinolones. Here we report the development of acute renal failure within a few days of initiating oral ciprofloxacin therapy and briefly describe the different types of renal failure secondary to fluoroquinolone administration. Clinical studies demonstrate that using fluoroquinolones with other potentially nephrotoxic medications requires monitoring of renal function to limit the renal toxicity with these medications. Also, the risk-benefit profile of patients requiring fluoroquinolones should be considered.

  11. Epoxyeicosanoids promote organ and tissue regeneration.

    Science.gov (United States)

    Panigrahy, Dipak; Kalish, Brian T; Huang, Sui; Bielenberg, Diane R; Le, Hau D; Yang, Jun; Edin, Matthew L; Lee, Craig R; Benny, Ofra; Mudge, Dayna K; Butterfield, Catherine E; Mammoto, Akiko; Mammoto, Tadanori; Inceoglu, Bora; Jenkins, Roger L; Simpson, Mary A; Akino, Tomoshige; Lih, Fred B; Tomer, Kenneth B; Ingber, Donald E; Hammock, Bruce D; Falck, John R; Manthati, Vijaya L; Kaipainen, Arja; D'Amore, Patricia A; Puder, Mark; Zeldin, Darryl C; Kieran, Mark W

    2013-08-13

    Epoxyeicosatrienoic acids (EETs), lipid mediators produced by cytochrome P450 epoxygenases, regulate inflammation, angiogenesis, and vascular tone. Despite pleiotropic effects on cells, the role of these epoxyeicosanoids in normal organ and tissue regeneration remains unknown. EETs are produced predominantly in the endothelium. Normal organ and tissue regeneration require an active paracrine role of the microvascular endothelium, which in turn depends on angiogenic growth factors. Thus, we hypothesize that endothelial cells stimulate organ and tissue regeneration via production of bioactive EETs. To determine whether endothelial-derived EETs affect physiologic tissue growth in vivo, we used genetic and pharmacological tools to manipulate endogenous EET levels. We show that endothelial-derived EETs play a critical role in accelerating tissue growth in vivo, including liver regeneration, kidney compensatory growth, lung compensatory growth, wound healing, corneal neovascularization, and retinal vascularization. Administration of synthetic EETs recapitulated these results, whereas lowering EET levels, either genetically or pharmacologically, delayed tissue regeneration, demonstrating that pharmacological modulation of EETs can affect normal organ and tissue growth. We also show that soluble epoxide hydrolase inhibitors, which elevate endogenous EET levels, promote liver and lung regeneration. Thus, our observations indicate a central role for EETs in organ and tissue regeneration and their contribution to tissue homeostasis.

  12. Renal teratogens.

    Science.gov (United States)

    Morgan, Thomas M; Jones, Deborah P; Cooper, William O

    2014-09-01

    In utero exposure to certain drugs early in pregnancy may adversely affect nephrogenesis. Exposure to drugs later in pregnancy may affect the renin-angiotensin system, which could have an impact on fetal or neonatal renal function. Reduction in nephron number and renal function could have adverse consequences for the child several years later. Data are limited on the information needed to guide decisions for patients and providers regarding the use of certain drugs in pregnancy. The study of drug nephroteratogenicity has not been systematized, a large, standardized, global approach is needed to evaluate the renal risks of in utero drug exposures.

  13. Gene expression profile of the regeneration epithelium during axolotl limb regeneration.

    Science.gov (United States)

    Campbell, Leah J; Suárez-Castillo, Edna C; Ortiz-Zuazaga, Humberto; Knapp, Dunja; Tanaka, Elly M; Crews, Craig M

    2011-07-01

    Urodele amphibians are unique among adult vertebrates in their ability to regenerate missing limbs. The process of limb regeneration requires several key tissues including a regeneration-competent wound epidermis called the regeneration epithelium (RE). We used microarray analysis to profile gene expression of the RE in the axolotl, a Mexican salamander. A list of 125 genes and expressed sequence tags (ESTs) showed a ≥1.5-fold expression in the RE than in a wound epidermis covering a lateral cuff wound. A subset of the RE ESTs and genes were further characterized for expression level changes over the time-course of regeneration. This study provides the first large scale identification of specific gene expression in the RE.

  14. Sarcoidose renal

    Directory of Open Access Journals (Sweden)

    AQUINO MARIA ENEDINA CLAUDINO DE

    2001-01-01

    Full Text Available Em uma mulher de 62 anos, branca, em avaliação pré-operatória de facectomia, foram detectadas alterações urinárias, tendo sido firmados os diagnósticos de calculose renal esquerda e exclusão renal homolateral. No pré-operatório da nefrectomia foram evidenciados processo pulmonar intersticial bilateral e adenopatia torácica, cuja investigação foi adiada para após a cirurgia. No rim retirado foram detectados granulomas epitelióides não necrotizantes, o mesmo ocorrendo posteriormente em biópsia transbrônquica. A paciente foi tratada com metilprednisolona, com discreta melhora pulmonar, o que não ocorreu com a função renal. O diagnóstico final foi de sarcoidose com envolvimento pulmonar, ganglionar torácico e renal.

  15. Renal failure

    Institute of Scientific and Technical Information of China (English)

    1993-01-01

    930150 Epidermal growth factor and its recep-tor in the renal tissue of patients with acute re-nal failure and normal persons.LIU Zhihong(刘志红),et al.Jinling Hosp,Nanjing,210002.Natl Med J China 1992;72(10):593-595.Epidermal growth factor(EGF)and its receptor(EGF-R)were identified by immunohis-tochemical method(4 layer PAP)in the renaltissue specimens obtained from 11 normal kid-neys and 17 cases of acute renal failure(ARF).The quantitative EGF and EGF-R in the tissuewere expressed as positive tubules per mm~2.The amount of EGF and EGF-R in renal tissue

  16. Renal failure

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    2005234 Association between serum fetuin-A and clinical outcome in end-stage renal disease patients. WANG Kai(王开), Dept Renal Dis, Renji Hosp Shanghai, 2nd Med Univ, Shanghai 200001. Chin J Nephrol, 2005;21(2):72-75. Objective: To investigate the change of serum fetuin-A level before and after dialysis, and the association of serum fetuin-A level with clinical parameters

  17. Renal failure

    Institute of Scientific and Technical Information of China (English)

    1995-01-01

    950351 Serum erythropoietin levels in chronic renalinsufficiency.ZHAI Depei(翟德佩),et al.DeptNephrol.General Hosp,Tianjin Med Univ,Tianjin,300000.Tianjin Med J 1995;23(1):19-21.Patients with chronic renal insufficiency(CRI) areoften associated with anemia.The deficiency of EPOproduction in the kidney is thought to be a key factorin the pathogenesis of renal anemia.Serum erythropoi-

  18. Renal Hemangiopericytoma

    Directory of Open Access Journals (Sweden)

    İbrahim Halil Bozkurt

    2015-03-01

    Full Text Available Hemangiopericytoma is an uncommon perivascular tumor originating from pericytes in the pelvis, head and tneck, and the meninges; extremely rarely in the urinary system. We report a case of incidentally detected renal mass in which radiologic evaluation was suggestive of renal cell carcinoma. First, we performed partial nephrectomy, and then, radical nephrectomy because of positive surgical margins and the pathological examination of the surgical specimen that revealed a hemangiopericytoma. No additional treatment was administered.

  19. Regenerating a kidney in a lymph node.

    Science.gov (United States)

    Francipane, Maria Giovanna; Lagasse, Eric

    2016-10-01

    The ultimate treatment for end-stage renal disease (ESRD) is orthotopic transplantation. However, the demand for kidney transplantation far exceeds the number of available donor organs. While more than 100,000 Americans need a kidney, only 17,000 people receive a kidney transplant each year (National Kidney Foundation's estimations). In recent years, several regenerative medicine/tissue engineering approaches have been exploited to alleviate the kidney shortage crisis. Although these approaches have yielded promising results in experimental animal models, the kidney is a complex organ and translation into the clinical realm has been challenging to date. In this review, we will discuss cell therapy-based approaches for kidney regeneration and whole-kidney tissue engineering strategies, including our innovative approach to regenerate a functional kidney using the lymph node as an in vivo bioreactor.

  20. Renal Failure in Pregnancy.

    Science.gov (United States)

    Balofsky, Ari; Fedarau, Maksim

    2016-01-01

    Renal failure during pregnancy affects both mother and fetus, and may be related to preexisting disease or develop secondary to diseases of pregnancy. Causes include hypovolemia, sepsis, shock, preeclampsia, thrombotic microangiopathies, and renal obstruction. Treatment focuses on supportive measures, while pharmacologic treatment is viewed as second-line therapy, and is more useful in mitigating harmful effects than treating the underlying cause. When supportive measures and pharmacotherapy prove inadequate, dialysis may be required, with the goal being to prolong pregnancy until delivery is feasible. Outcomes and recommendations depend primarily on the underlying cause.

  1. Meropenem population pharmacokinetics in critically ill patients with septic shock and continuous renal replacement therapy: influence of residual diuresis on dose requirements.

    Science.gov (United States)

    Ulldemolins, Marta; Soy, Dolors; Llaurado-Serra, Mireia; Vaquer, Sergi; Castro, Pedro; Rodríguez, Alejandro H; Pontes, Caridad; Calvo, Gonzalo; Torres, Antoni; Martín-Loeches, Ignacio

    2015-09-01

    Meropenem dosing in critically ill patients with septic shock and continuous renal replacement therapy (CRRT) is complex, with the recommended maintenance doses being 500 mg to 1,000 mg every 8 h (q8h) to every 12 h. This multicenter study aimed to describe the pharmacokinetics (PKs) of meropenem in this population to identify the sources of PK variability and to evaluate different dosing regimens to develop recommendations based on clinical parameters. Thirty patients with septic shock and CRRT receiving meropenem were enrolled (153 plasma samples were tested). A population PK model was developed with data from 24 patients and subsequently validated with data from 6 patients using NONMEM software (v.7.3). The final model was characterized by CL = 3.68 + 0.22 · (residual diuresis/100) and V = 33.00 · (weight/73)(2.07), where CL is total body clearance (in liters per hour), residual diuresis is the volume of residual diuresis (in milliliters per 24 h), and V is the apparent volume of distribution (in liters). CRRT intensity was not identified to be a CL modifier. Monte Carlo simulations showed that to maintain concentrations of the unbound fraction (fu ) of drug above the MIC of the bacteria for 40% of dosing interval T (referred to as 40% of the ƒ uT >MIC), a meropenem dose of 500 mg q8h as a bolus over 30 min would be sufficient regardless of the residual diuresis. If 100% of the ƒ uT >MIC was chosen as the target, oligoanuric patients would require 500 mg q8h as a bolus over 30 min for the treatment of susceptible bacteria (MIC dose given as an infusion over 3 h. If bacteria with MICs close to the resistance breakpoint (2 to 4 mg/liter) were to be treated with meropenem, a dose of 500 mg every 6 h would be necessary: a bolus over 30 min for oligoanuric patients and an infusion over 3 h for patients with preserved diuresis. Our results suggest that residual diuresis may be an easy and inexpensive tool to help with titration of the meropenem dose and infusion

  2. Modeling Outcome of Patients on Renal Replacement Therapy

    NARCIS (Netherlands)

    Y.S. Liem (Ylian Serina)

    2008-01-01

    textabstractThe incidence of end-stage renal disease is increasing and therefore, the number of patients requiring renal replacement therapy (RRT), renal dialysis or renal transplantation (RTx), has been rising. The various forms of RRT are associated with differences in survival and quality of life

  3. End-stage renal disease causes an imbalance between endothelial and smooth muscle progenitor cells

    NARCIS (Netherlands)

    Westerweel, Peter E; Hoefer, Imo E; Blankestijn, Peter J; de Bree, Petra; Groeneveld, Dafna; van Oostrom, Olivia; Braam, Branko; Koomans, Hein A; Verhaar, Marianne C

    2007-01-01

    Patients with end-stage renal disease (ESRD) on hemodialysis have an increased risk of cardiovascular disease (CVD). Circulating endothelial progenitor cells (EPC) contribute to vascular regeneration and repair, thereby protecting against CVD. However, circulating smooth muscle progenitor cells (SPC

  4. The Analysis of Activated Carbon Regeneration Technologies

    Institute of Scientific and Technical Information of China (English)

    姚芳

    2014-01-01

    A series of methods for activated carbon regeneration were briefly introduced.Such as thermal regeneration,chemical regeneration,biochemical regeneration,and newly supercritical fluid regeneration, electrochemical regeneration,light-catalyzed regeneration,and microwave radiation method,and the developing trend of activated carbon regeneration was predicted.

  5. Renal denervation and hypertension.

    Science.gov (United States)

    Schlaich, Markus P; Krum, Henry; Sobotka, Paul A; Esler, Murray D

    2011-06-01

    Essential hypertension remains one of the biggest challenges in medicine with an enormous impact on both individual and society levels. With the exception of relatively rare monogenetic forms of hypertension, there is now general agreement that the condition is multifactorial in nature and hence requires therapeutic approaches targeting several aspects of the underlying pathophysiology. Accordingly, all major guidelines promote a combination of lifestyle interventions and combination pharmacotherapy to reach target blood pressure (BP) levels in order to reduce overall cardiovascular risk in affected patients. Although this approach works for many, it fails in a considerable number of patients for various reasons including drug-intolerance, noncompliance, physician inertia, and others, leaving them at unacceptably high cardiovascular risk. The quest for additional therapeutic approaches to safely and effectively manage hypertension continues and expands to the reappraisal of older concepts such as renal denervation. Based on the robust preclinical and clinical data surrounding the role of renal sympathetic nerves in various aspects of BP control very recent efforts have led to the development of a novel catheter-based approach using radiofrequency (RF) energy to selectively target and disrupt the renal nerves. The available evidence from the limited number of uncontrolled hypertensive patients in whom renal denervation has been performed are auspicious and indicate that the procedure has a favorable safety profile and is associated with a substantial and presumably sustained BP reduction. Although promising, a myriad of questions are far from being conclusively answered and require our concerted research efforts to explore the full potential and possible risks of this approach. Here we briefly review the science surrounding renal denervation, summarize the current data on safety and efficacy of renal nerve ablation, and discuss some of the open questions that need

  6. Wegener's granulomatosis with renal involvement: patient survival and correlations between initial renal function, renal histology, therapy and renal outcome.

    Science.gov (United States)

    Andrassy, K; Erb, A; Koderisch, J; Waldherr, R; Ritz, E

    1991-04-01

    Patient survival and renal outcome were followed in 25 patients with biopsy confirmed Wegener's granulomatosis and renal involvement. Fourteen out of 25 patients required dialysis on admission, 11/25 patients did not. All patients were treated with a novel protocol comprising methylprednisolone and cyclophosphamide. The median follow-up observation was 36 months (12-113 months). With the exception of 1 patient (who died from causes not related to Wegener's granulomatosis) all patients are alive. Among the patients initially requiring dialysis (n = 14) 4 are in terminal renal failure after 0, 7, 21 and 38 months respectively. In the nondialysis group (n = 11) only 1 patient subsequently required chronic dialysis 30 months after clinical admission. Renal failure was due to non-compliance with immunosuppressive therapy in at least 2 patients. Percentage of obsolescent glomeruli and the degree of tubulointerstitial lesions, but not active glomerular lesions (crescents, necroses) predicted renal outcome. The major cause of renal functional impairment was relapse of Wegener's granulomatosis usually within 2 years after clinical remission. Therefore prolonged treatment with cyclophosphamide for at least 2 years after clinical remission is recommended. Two patients with initially negative immunohistology had a second renal biopsy which revealed de novo appearance of mesangial IgA deposits.

  7. Requirement of plasminogen binding to its cell-surface receptor α-enolase for efficient regeneration of normal and dystrophic skeletal muscle.

    Directory of Open Access Journals (Sweden)

    Àngels Díaz-Ramos

    Full Text Available Adult regenerative myogenesis is central for restoring normal tissue structure and function after muscle damage. In muscle repair after injury, as in severe myopathies, damaged and necrotic fibers are removed by infiltrating inflammatory cells and then replaced by muscle stem cells or satellite cells, which will fuse to form new myofibers. Extracellular proteolysis mediated by uPA-generated plasmin plays a critical role in controlling inflammation and satellite-cell-dependent myogenesis. α-enolase has been described as plasminogen receptor in several cell types, where it acts concentrating plasmin proteolytic activity on the cell surface. In this study, we investigated whether α-enolase plasminogen receptor plays a regulatory role during the muscular repair process. Inhibitors of α-enolase/plasminogen binding: MAb11G1 (a monoclonal antibody against α-enolase and ε-aminocaproic acid, EACA (a lysine analogue inhibited the myogenic abilities of satellite cells-derived myoblasts. Furthermore, knockdown of α-enolase decreased myogenic fusion of myoblasts. Injured wild-type mice and dystrophic mdx mice were also treated with MAb11G1 and EACA. These treatments had negative impacts on muscle repair impairing satellite cell functions in vitro in agreement with blunted growth of new myofibers in vivo. Furthermore, both MAb11G1 and EACA treatments impaired adequate inflammatory cell infiltration and promoted extracellular matrix deposition in vivo, which resulted in persistent degeneration. These results demonstrate the novel requirement of α-enolase for restoring homeostasis of injured muscle tissue, by controlling the pericellular localization of plasmin activity.

  8. Ultrasonography in chronic renal failure

    Energy Technology Data Exchange (ETDEWEB)

    Buturovic-Ponikvar, Jadranka E-mail: jadranka.buturovic@mf.uni-lj.si; Visnar-Perovic, Alenka

    2003-05-01

    Many chronic renal diseases lead to the final common state of decrease in renal size, parenchymal atrophy, sclerosis and fibrosis. The ultrasound image show a smaller kidney, thinning of the parenchyma and its hyperechogenicity (reflecting sclerosis and fibrosis). The frequency of renal cysts increases with the progression of the disease. Ultrasound generally does not allow for the exact diagnosis of an underlying chronic disease (renal biopsy is usually required), but it can help to determine an irreversible disease, assess prognosis and avoid unnecessary diagnostic or therapeutic procedures. The main exception in which the ultrasound image does not show a smaller kidney with parenchymal atrophy is diabetic nephropathy, the leading cause of chronic and end-stage renal failure in developed countries in recent years. In this case, both renal size and parenchymal thickness are preserved until end-stage renal failure. Doppler study of intrarenal vessels can provide additional information about microvascular and parenchymal lesions, which is helpful in deciding for or against therapeutic intervention and timely planning for optimal renal replacement therapy option.

  9. Strategies for lung regeneration

    Directory of Open Access Journals (Sweden)

    Thomas H. Petersen

    2011-05-01

    Full Text Available Due to the limited ability of the adult lung to regenerate and the frequency of lung disease, the lung is a tissue that can especially benefit from regenerative medicine. Prospects for lung regeneration have made great strides in the past year. In this review, we summarize recent progress and key challenges for approaches in lung regenerative medicine. With a focus on the matrix components critical for the development of regenerative lung tissues, we discuss possible cell sources for lung regeneration, key matrix effects on cell repopulation, and physical stimuli that will aid in the growth of lung tissues in vitro.

  10. Tooth regeneration: Current status

    Directory of Open Access Journals (Sweden)

    Dadu Shifali

    2009-01-01

    Full Text Available Regeneration of a functional tooth has the potential to be a promising therapeutic strategy. Experiments have shown that with the use of principles of bioengineering along with adult stem cells, scaffold material, and signaling molecules, tooth regeneration is possible. Research work is in progress on creating a viable bioroot with all its support. A new culture needs to be created that can possibly provide all the nutrients to the stem cells. With the ongoing research, tissue engineering is likely to revolutionize dental health and well-being of people by regenerating teeth over the next decade.

  11. Tooth regeneration: current status.

    Science.gov (United States)

    Dadu, Shifali S

    2009-01-01

    Regeneration of a functional tooth has the potential to be a promising therapeutic strategy. Experiments have shown that with the use of principles of bioengineering along with adult stem cells, scaffold material, and signaling molecules, tooth regeneration is possible. Research work is in progress on creating a viable bioroot with all its support. A new culture needs to be created that can possibly provide all the nutrients to the stem cells. With the ongoing research, tissue engineering is likely to revolutionize dental health and well-being of people by regenerating teeth over the next decade.

  12. Regeneration Heat Exchange

    Energy Technology Data Exchange (ETDEWEB)

    J. Lin

    2003-07-30

    The original project goals were to establish the viability of the proposed gas turbine regenerator concept by performing the following tasks: (1) Perform detailed design of a working model of the regenerator concept. (2) Construct a ''bench-top'' model of the regenerator concept based upon the detail design. (3) Test the bench-top model and gather data to support the concept's viability. The project funding was used to acquire the tools and material to perform the aforementioned tasks.

  13. Guided tissue regeneration in periapical surgery.

    Science.gov (United States)

    Lin, Louis; Chen, Melody Y-H; Ricucci, Domenico; Rosenberg, Paul A

    2010-04-01

    Tissue regeneration by using membrane barriers and bone grafting materials in periapical surgery is an example of tissue engineering technology. Membrane barriers and/or bone grafts are often used to enhance periapical new bone formation. However, the periapical tissues also consist of the periodontal ligament (PDL) and cementum. For regeneration of the periapical tissues after periapical surgery, one of the important requirements is recruitment and differentiation of progenitor/stem cells into committed pre-osteoblasts, pre-PDL cells, and pre-cementoblasts. Homing of progenitor/stem cells into the wounded periapical tissues is regulated by factors such as stromal cell-derived factor 1, growth factors/cytokines, and by microenvironmental cues such as adhesion molecules and extracellular matrix and associated noncollagenous molecules. Tissue regeneration after injury appears to recapitulate the pathway of normal embryonic tissue development. Multiple tissue regeneration involves a complex interaction between different cells, extracellular matrix, growth/differentiation factors, and microenvironmental cues. Little is known concerning the biologic mechanisms that regulate temporal and spatial relationship between alveolar bone, PDL, and cementum regeneration during periapical wound healing. Simply applying a membrane barrier and/or bone graft during periapical surgery might not result in complete regeneration of the periapical tissues. It has not been clearly demonstrated that these biomaterials are capable of recruiting progenitor/stem cells and inducing these undifferentiated mesenchymal cells to differentiate into PDL cells and cementoblasts after periapical surgery.

  14. Refining the Ciona intestinalis model of central nervous system regeneration.

    Directory of Open Access Journals (Sweden)

    Carl Dahlberg

    Full Text Available BACKGROUND: New, practical models of central nervous system regeneration are required and should provide molecular tools and resources. We focus here on the tunicate Ciona intestinalis, which has the capacity to regenerate nerves and a complete adult central nervous system, a capacity unusual in the chordate phylum. We investigated the timing and sequence of events during nervous system regeneration in this organism. METHODOLOGY/PRINCIPAL FINDINGS: We developed techniques for reproducible ablations and for imaging live cellular events in tissue explants. Based on live observations of more than 100 regenerating animals, we subdivided the regeneration process into four stages. Regeneration was functional, as shown by the sequential recovery of reflexes that established new criteria for defining regeneration rates. We used transgenic animals and labeled nucleotide analogs to describe in detail the early cellular events at the tip of the regenerating nerves and the first appearance of the new adult ganglion anlage. CONCLUSIONS/SIGNIFICANCE: The rate of regeneration was found to be negatively correlated with adult size. New neural structures were derived from the anterior and posterior nerve endings. A blastemal structure was implicated in the formation of new neural cells. This work demonstrates that Ciona intestinalis is as a useful system for studies on regeneration of the brain, brain-associated organs and nerves.

  15. Irradiation inhibits the regeneration of aneurogenic limbs. [X radiation

    Energy Technology Data Exchange (ETDEWEB)

    Wallace, H.; Maden, M.

    1976-03-01

    The developing arms of axolotl larvae from the 2-digit stage onward and the aneurogenic arms of surgically denervated larvae maintained in parabiosis are able to regenerate after amputation. Such regeneration is uniformly inhibited by local irradiation of the arm, whether innervated or not. This demonstration refutes a recent hypothesis that x-rays interfere with a special activity of nerves required for regeneration, and supports the earlier concept that x-rays act directly on those cells which must proliferate to form the regenerated tissues.

  16. Influence of input acoustic power on regenerator's performance

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Performance of a pulse tube cooler significantly depends on the efficient operation of its regenerator. Influence of input acoustic power on regenerator's performance is simulated and analyzed with simple harmonic analysis method. Given regenerator's dimensions and pressure ratio, there is an optimal input acoustic power for achieving a highest coefficient of performance, due to a compromise between relative time-averaged total energy flux in regenerator and relative acoustic power at regenerator's cold end. Additionally, optimal dimensions of regenerator are also estimated and presented for different input acoustic powers. The computed optimal diameter obviously increases with increase of input acoustic power, while the optimal length decreases slightly,and as a result, a larger input acoustic power requires a smaller aspect ratio (length over diameter).

  17. Chemical genetics and regeneration.

    Science.gov (United States)

    Sengupta, Sumitra; Zhang, Liyun; Mumm, Jeff S

    2015-01-01

    Regeneration involves interactions between multiple signaling pathways acting in a spatially and temporally complex manner. As signaling pathways are highly conserved, understanding how regeneration is controlled in animal models exhibiting robust regenerative capacities should aid efforts to stimulate repair in humans. One way to discover molecular regulators of regeneration is to alter gene/protein function and quantify effect(s) on the regenerative process: dedifferentiation/reprograming, stem/progenitor proliferation, migration/remodeling, progenitor cell differentiation and resolution. A powerful approach for applying this strategy to regenerative biology is chemical genetics, the use of small-molecule modulators of specific targets or signaling pathways. Here, we review advances that have been made using chemical genetics for hypothesis-focused and discovery-driven studies aimed at furthering understanding of how regeneration is controlled.

  18. RENAL FUNCTION DERANGEMENT IN HELLP SYNDROME

    Directory of Open Access Journals (Sweden)

    Anusha Harihara Gopalan

    2017-04-01

    Full Text Available BACKGROUND HELLP is the acronym for haemolysis, elevated liver enzymes and low platelet count. HELLP syndrome is a form of severe preeclampsia with an incidence of 0.2-0.6% of all pregnancies. The aim of our study is to evaluate the trend of renal dysfunction in HELLP syndrome patients. MATERIALS AND METHODS This is a cross-sectional observational study conducted in Department of Obstetrics and Gynaecology, Institute of Maternal and Child Health, Government Medical College, Kozhikode, during the period of 12 months from January 2013 to December 2013. All patients with HELLP syndrome were included in the study and their renal function tests monitored. RESULTS Results were renal dysfunction prevalence in HELLP syndrome patients is 77%. The renal impairment recovered by 6 days on an average. All had normal renal function tests at the time of discharge. Patients with renal function derangement had a mean duration of hospital stay and transfusion requirements more than the patients without renal function derangement, which was statistically significant (p value 0.036. Haemodialysis required for one out of 60 patients. One maternal mortality due to acute renal failure. CONCLUSION As the prevalence of renal dysfunction is high, some amount of renal impairment maybe a part of the HELLP syndrome disease spectrum itself. Though the incidence of progression to acute renal failure and dialysis is less, this is the important cause of morbidity and mortality in HELLP syndrome patients.

  19. Neuromodulatory nerve regeneration: adipose tissue-derived stem cells and neurotrophic mediation in peripheral nerve regeneration.

    Science.gov (United States)

    Widgerow, Alan D; Salibian, Ara A; Lalezari, Shadi; Evans, Gregory R D

    2013-12-01

    Peripheral nerve injury requiring nerve gap reconstruction remains a major problem. In the quest to find an alternative to autogenous nerve graft procedures, attempts have been made to differentiate mesenchymal stem cells into neuronal lineages in vitro and utilize these cellular constructs for nerve regeneration. Unfortunately, this has produced mixed results, with no definitive procedure matching or surpassing traditional nerve grafting procedures. This review presents a different approach to nerve regeneration. The literature was reviewed to evaluate current methods of using adipose-derived stem cells (ADSCs) for peripheral nerve regeneration in in vivo models of animal peripheral nerve injury. The authors present cited evidence for directing nerve regeneration through paracrine effects of ADSCs rather than through in vitro nerve regeneration. The paracrine effects rely mainly, but not solely, on the elaboration of nerve growth factors and neurotrophic mediators that influence surrounding host cells to orchestrate in vivo nerve regeneration. Although this paradigm has been indirectly referred to in a host of publications, few major efforts for this type of neuromodulatory nerve regeneration have been forthcoming. The ADSCs are initially "primed" in vitro using specialized controlled medium (not for neuronal differentiation but for sustainability) and then incorporated into a hydrogel base matrix designed for this purpose. This core matrix is then introduced into a natural collagen-based nerve conduit. The prototype design concepts, evidence for paracrine influences, and regulatory hurdles that are avoided using this approach are discussed. Copyright © 2013 Wiley Periodicals, Inc.

  20. A critical role for matrix metal loproteinases in liver regeneration

    NARCIS (Netherlands)

    Alwayn, Ian P. J.; Verbesey, Jennifer E.; Kim, Sendia; Roy, Roopali; Arsenault, Danielle A.; Greene, Arin K.; Novak, Katherine; Laforme, Andrea; Lee, Sang; Moses, Marsha A.; Puder, Mark

    2008-01-01

    Background. Matrix metalloproteinases (MMPs), tumor necrosis factor-alpha (TNF-alpha), and interleukin-6 (IL-6) are mediators of liver regeneration. To determine whether MMPs are required for normal hepatic regeneration, we performed 67% hepatectomies on mice treated with a broad-spectrum MMP-inhibi

  1. REGENERATION OF FULL-THICKNESS WOUNDS USING COLLAGEN SPLIT GRAFTS

    NARCIS (Netherlands)

    VANLUYN, MJA; VERHEUL, J; VANWACHEM, PB

    1995-01-01

    Collagen-based skin substitutes are among the most promising materials to improve regeneration of full-thickness wounds. However, additional meshed grafts or cultured epidermal grafts are still required to create epidermal regeneration. To avoid this, we substituted collagen-based split grafts, i.e.

  2. Air regenerating and conditioning

    Science.gov (United States)

    Grishayenkov, B. G.

    1975-01-01

    Various physicochemical methods of regenerating and conditioning air for spacecraft are described with emphasis on conditions which affect efficiency of the system. Life support systems used in closed, hermetically sealed environments are discussed with references to actual application in the Soviet Soyuz and Voskhod manned spacecraft. Temperature and humidity control, removal of carbon dioxide, oxygen regeneration, and removal of bacteria and viruses are among the factors considered.

  3. Nanostructured Biomaterials for Regeneration**

    OpenAIRE

    Wei, Guobao; Ma, Peter X.

    2008-01-01

    Biomaterials play a pivotal role in regenerative medicine, which aims to regenerate and replace lost/dysfunctional tissues or organs. Biomaterials (scaffolds) serve as temporary 3D substrates to guide neo tissue formation and organization. It is often beneficial for a scaffolding material to mimic the characteristics of extracellular matrix (ECM) at the nanometer scale and to induce certain natural developmental or/and wound healing processes for tissue regeneration applications. This article...

  4. Renal Cysts

    Science.gov (United States)

    ... as “simple” cysts, meaning they have a thin wall and contain water-like fluid. Renal cysts are fairly common in ... simple kidney cysts, meaning they have a thin wall and only water-like fluid inside. They are fairly common in ...

  5. Renal failure

    Institute of Scientific and Technical Information of China (English)

    1997-01-01

    970363 Effect on serum PTH and 1, 25(OH)2 D3levels of rapid correction of metabolic acidosis in CRFpatients with secondary hyperparathyroidism. YUANQunsheng(袁群生), et al. Renal Div, PUMC Hosp,Beijing, 100730. Chin J Nephrol 1996; 12(6): 328-331.

  6. Drug-induced renal injury

    African Journals Online (AJOL)

    Drugs can cause acute renal failure by causing pre-renal, intrinsic or post-renal toxicity. Pre-renal ... incidence of drug dose adjustment in renal impairment in the SAMJ. ... Fever, haemolytic anaemia, thrombocytopenia, renal impairment and.

  7. From kidney development to drug delivery and tissue engineering strategies in renal regenerative medicine

    NARCIS (Netherlands)

    Dankers, Patricia Y. W.; Boomker, Jasper M.; Meijer, E. W.; Popa, Eliane R.; van Luyn, Marja J. A.

    2011-01-01

    Deterioration of renal function is typically slow but progressive, and therefore renal disease is often diagnosed in a late stage when already serious complaints occur. Ultimately when renal function has dropped below 10%, renal replacement is required. Renal transplantation provides a long-term sol

  8. Reduced renal function is associated with progression to AIDS but not with overall mortality in HIV-infected kenyan adults not initially requiring combination antiretroviral therapy

    Directory of Open Access Journals (Sweden)

    Gupta Samir K

    2011-06-01

    Full Text Available Abstract Background The World Health Organization (WHO has recently recommended that antiretrovirals be initiated in all individuals with CD4 counts of less than 350 cells/mm3. For countries with resources too limited to expand care to all such patients, it would be of value to able to identify and target populations at highest risk of HIV progression. Renal disease has been identified as a risk factor for disease progression or death in some populations. Methods Times to meeting combination antiretroviral therapy (cART initiation criteria (developing either a CD4 count 3 or WHO stage 3 or 4 disease and overall mortality were evaluated in cART-naïve, HIV-infected Kenyan adults with CD4 cell counts ≥200/mm3 and with WHO stage 1 or 2 disease. Cox proportional hazard regression models were used to evaluate the associations between renal function and these endpoints. Results We analyzed data of 7383 subjects with a median follow-up time of 59 (interquartile range, 27-97 weeks. In Cox regression analyses adjusted for age, sex, WHO disease stage, CD4 cell count and haemoglobin, estimated creatinine clearance (CrCl 2 was associated with shorter times to meeting cART initiation criteria (HR 1.39; 95% CI, 1.22-1.58, but not with overall mortality. CrCl and eGFR remained associated with shorter times to cART initiation criteria, but neither was associated with mortality, in weight-adjusted analyses. Conclusions In this large natural history study, reduced renal function was strongly associated with faster HIV disease progression in adult Kenyans not initially meeting cART initiation criteria. As such, renal function measurement in resource-limited settings may be an inexpensive method to identify those most in need of cART to prevent progression to AIDS. The initial association between reduced CrCl, but not reduced eGFR, and greater mortality was explained by the low weights in this population.

  9. Emerging rules for inducing organ regeneration.

    Science.gov (United States)

    Yannas, Ioannis V

    2013-01-01

    We review the available evidence for regeneration of adult organs of very diverse nature and examine the applicability of simple rules that can be used to summarize these treatments. In the field of regenerative medicine no widely accepted paradigm is currently available that can guide formulation of new theories on the mechanism of regeneration in adults and open new directions for improved regeneration outcomes. The four rules have emerged from multiyear quantitative studies with skin and peripheral nerve regeneration using scaffold libraries based on a simple, well-defined collagen scaffold. These largely quantitative rules distinguish sharply between spontaneously regenerative and nonregenerative tissues, select the two reactants that are required for regeneration, recognize the essential modification of the wound healing process that must be realized prior to regeneration, and identify three structural features of scaffolds that are required for regenerative activity. The combined evidence points at certain requirements for the structure of a collagen scaffold with regenerative activity. An active scaffold emerges as a temporarily insoluble collagen surface, equipped with sufficient ligands for integrins of contractile cells, that inhibits wound contraction while also serving as a topographic template for new stroma synthesis. The four rules, based on studies with just two organs (skin and peripheral nerves), are now viewed in the context of ongoing studies using scaffolds based on decellularized matrices, which are mostly based on collagen. Decellularized matrices have been used during the past few years to regenerate, in whole or in part, the urethra, the abdominal wall, the Achilles tendon, the bladder, the trachea and other organs in several animal models and occasionally in humans. Although these acellular matrices are distinctly different from simple collagen scaffolds, and the methods used by the investigators are still evolving, the results obtained

  10. Rupture of Renal Transplant

    Directory of Open Access Journals (Sweden)

    Shona Baker

    2015-01-01

    Full Text Available Background. Rupture of renal allograft is a rare and serious complication of transplantation that is usually attributed to acute rejection, acute tubular necrosis, or renal vein thrombosis. Case Presentation. LD, a 26-year-old male with established renal failure, underwent deceased donor transplantation using kidney from a 50-year-old donor with acute kidney injury (Cr 430 mmol/L. LD had a stormy posttransplant recovery and required exploration immediately for significant bleeding. On day three after transplant, he developed pain/graft swelling and another significant haemorrhage with cardiovascular compromise which did not respond to aggressive resuscitation. At reexploration, the renal allograft was found to have a longitudinal rupture and was removed. Histology showed features of type IIa Banff 97 acute vascular rejection, moderate arteriosclerosis, and acute tubular necrosis. Conclusion. Possible ways of avoiding allograft rupture include use of well-matched, good quality kidneys; reducing or managing risk factors that would predispose to delayed graft function; ensuring a technically satisfactory transplant procedure with short cold and warm ischemia times; and avoiding large donor-recipient age gradients.

  11. Transjugular renal biopsy in the treatment of patients with cirrhosis and renal abnormalities.

    Science.gov (United States)

    Jouët, P; Meyrier, A; Mal, F; Callard, P; Guettier, C; Stordeur, D; Trinchet, J C; Beaugrand, M

    1996-11-01

    When renal lesions are suspected in patients with cirrhosis, clotting disorders often preclude percutaneous renal biopsy. This study was undertaken to determine whether transjugular renal biopsy is possible, safe, and useful in such patients. From 1987 to 1994, 70 patients with cirrhosis and clotting disorders underwent transjugular renal biopsies, providing renal tissue in 55. Of these 55 patients, 41 were Child-Pugh class B or C, 35 were alcoholic, serum creatinine levels were > or = 130 micromol/L in 46, and proteinuria was > or = 0.5 g/d in 37. Clinically significant complications of transjugular renal biopsy were persistent hematuria in 4 and perirenal hematoma in 4, requiring blood transfusions in 1 and 2 cases, respectively. There were no deaths related to renal biopsy. Renal lesions were identified as glomerular in 41 (74.5%), interstitial in 7, and end-stage in 2 and were absent in 5. Transjugular renal biopsy influenced treatment in 21 patients (38%), including 11 who were proposed for liver transplantation and 4 who had chronic liver rejection. Decisions based on results of transjugular renal biopsy were to perform liver transplantation in 8 and combined renal and liver transplantation in 5, whereas 2 were refused. In 6 other patients, the results of renal biopsy modified the medical regimen. We conclude that transjugular renal biopsy may be a useful procedure in patients with cirrhosis and clotting disorders. This technique does not entail undue risks and may influence treatment decisions, particularly in patients proposed for liver transplantation.

  12. PERFORMANCE ENHANCEMENT OF A MINIATURE STIRLING CRYOCOOLER WITH A MULTI MESH REGENERATOR DESIGN

    Directory of Open Access Journals (Sweden)

    KISHOR KUMAR V. V.

    2017-06-01

    Full Text Available A parametric study has been carried out using the software REGEN 3.3 to optimize the regenerator of a miniature Stirling cryocooler operating with a warm end temperature of 300 K and cold end temperature of 80 K. Regenerator designs which produce the maximum coefficient of performance (COP of the system is considered as an optimized regenerator. The length and diameter of the regenerator were fixed from the cooler system requirements. Single mesh regenerators made of 200, 250, 300, 400 and 450 Stainless Steel wire meshes were considered and the optimum phase angle and mesh size were obtained. A maximum COP of 0.1475 was obtained for 300 mesh regenerator at 70° phase angle. Then multi mesh regenerators were considered with finer mesh on the cold end and coarser mesh on the hot end. The optimum size and length of each mesh in the multi mesh regenerator and the optimum phase angle were calculated. The maximum COP of 0.156 was obtained for 200 300-400 multi mesh regenerator at 70° phase angle. The COP and net refrigeration obtained for an optimized multi mesh regenerator was found to be significantly higher than that of a single mesh regenerator. Thus a multi mesh regenerator design with a proper combination of regenerator mesh size and length can enhance the regenerator effectiveness.

  13. Renal involvement in antiphospholipid syndrome.

    Science.gov (United States)

    Sciascia, Savino; Cuadrado, Maria José; Khamashta, Munther; Roccatello, Dario

    2014-05-01

    Antiphospholipid syndrome (APS) is an autoimmune disease defined by the presence of arterial or venous thrombotic events and/or pregnancy morbidity in patients who test positive for antiphospholipid antibodies (aPLs). APS can be isolated (known as primary APS) or associated with other autoimmune diseases, such as systemic lupus erythematosus (SLE; known as secondary APS). The kidney is a major target organ in APS and renal thrombosis can occur at any level within the vasculature of the kidney (renal arteries, intrarenal arteries, glomerular capillaries and renal veins); events reflect the site and size of the involved vessels. Histological findings vary widely, including ischaemic glomeruli and thrombotic lesions without glomerular or arterial immune deposits on immunofluorescence. Renal prognosis is affected by the presence of aPLs in patients with lupus nephritis and can be poor. In patients with SLE and aPLs, biopsy should be performed because inflammatory and thrombotic lesions require different therapeutic approaches. Renal involvement in patients with definite APS is treated by anticoagulation with long-term warfarin. The range of renal manifestations associated with APS is broadening and, therefore, aPLs have increasing relevance in end-stage renal disease, transplantation and pregnancy.

  14. Tail regeneration affects the digestive performance of a Mediterranean lizard

    Science.gov (United States)

    Sagonas, Kostas; Karambotsi, Niki; Bletsa, Aristoula; Reppa, Aikaterini; Pafilis, Panayiotis; Valakos, Efstratios D.

    2017-04-01

    In caudal autotomy, lizards shed their tail to escape from an attacking predator. Since the tail serves multiple functions, caudal regeneration is of pivotal importance. However, it is a demanding procedure that requires substantial energy and nutrients. Therefore, lizards have to increase energy income to fuel the extraordinary requirements of the regenerating tail. We presumed that autotomized lizards would adjust their digestion to acquire this additional energy. To clarify the effects of tail regeneration on digestion, we compared the digestive performance before autotomy, during regeneration, and after its completion. Tail regeneration indeed increased gut passage time but did not affect digestive performance in a uniform pattern: though protein income was maximized, lipid and sugar acquisition remained stable. This divergence in proteins may be attributed to their particular role in tail reconstruction, as they are the main building blocks for tissue formation.

  15. Bioinorganics: synthetic growth factors for bone regeneration

    NARCIS (Netherlands)

    Tahmasebi Birgani, Z.

    2016-01-01

    Bone tissue is naturally able to regenerate when damaged. However, in many large defects caused by fractures due to aging or osteoporosis, trauma, tumor removal, etc., the natural regenerative ability of bone is not sufficient to fully heal the defect. In such cases, a graft is required to support t

  16. Defective fin regeneration in medaka fish (Oryzias latipes) with hypothyroidism.

    Science.gov (United States)

    Sekimizu, Koshin; Tagawa, Masatomo; Takeda, Hiroyuki

    2007-07-01

    Wild-type medaka are known to have remarkable capabilities of fin, or epimorphic, regeneration. However, a hypothyroid mutant, kamaitachi (kmi), frequently suffers from injury in fins, suggesting an important role of thyroid hormone in fin regeneration. This led us to examine the relationship between thyroid hormone and fin regeneration using medaka as a model. For this, we first set up a medaka experimental system in which the rate of regeneration was statistically analyzed after caudal fin amputation under normal and hypothyroid conditions. As expected, the regeneration of amputated caudal fins was delayed in hypothyroid kmi -/- mutants. We then examined wild-type medaka with thiourea-induced hypothyroidism to evaluate the requirement of thyroid hormone during epimorphic fin regeneration. The results demonstrate that the growth rate of regenerates was much reduced in severely hypothyroid medaka throughout the regeneration period. This reduction in regenerative rate was recovered by exogenous administration of L-thyroxine. The present study is thus the first to report the direct involvement of thyroid hormone in teleost fin regeneration, and provides a basic framework for future molecular and genetic analyses.

  17. Renale Osteopathie

    OpenAIRE

    Horn S

    2001-01-01

    Die renale Osteopathie umfaßt Erkrankungen des Knochens, die bei Patienten mit chronischen Nierenerkrankungen auftreten, wie den sekundären bzw. tertiären Hyperparathyreoidismus, die adynamische Knochenerkrankung und die Osteopathie nach Nierentransplantation. Durch die Identifikation des Kalzium-Sensing-Rezeptors bzw. des Vitamin D-Rezeptors hat sich unser Verständnis der Zusammenhänge in den letzten Jahren erheblich verbessert. Neue Medikamente versprechen effizientere Prophylaxe- und Thera...

  18. Renale Knochenerkrankungen

    Directory of Open Access Journals (Sweden)

    Mayer G

    2008-01-01

    Full Text Available Störungen des Mineral- und Knochenstoffwechsels sind bei fast allen Patienten mit chronischen Nierenerkrankungen anzutreffen. Pathogenetisch spielt eine Neigung zur Phosphatretention bei einer Reduktion der glomerulären Filtrationsrate die zentrale Rolle. Neben typischen, aber sehr variablen Veränderungen der Knochenstruktur (renale Osteopathie besteht auch eine sehr enge Assoziation zwischen diesen Störungen und dem massiv erhöhten kardiovaskulären Risiko der Patienten.

  19. Obesity and renal hemodynamics

    NARCIS (Netherlands)

    Bosma, R. J.; Krikken, J. A.; van der Heide, J. J. Homan; de Jong, P. E.; Navis, G. J.

    2006-01-01

    Obesity is a risk factor for renal damage in native kidney disease and in renal transplant recipients. Obesity is associated with several renal risk factors such as hypertension and diabetes that may convey renal risk, but obesity is also associated with an unfavorable renal hemodynamic profile

  20. Obesity and renal hemodynamics

    NARCIS (Netherlands)

    Bosma, R. J.; Krikken, J. A.; van der Heide, J. J. Homan; de Jong, P. E.; Navis, G. J.

    2006-01-01

    Obesity is a risk factor for renal damage in native kidney disease and in renal transplant recipients. Obesity is associated with several renal risk factors such as hypertension and diabetes that may convey renal risk, but obesity is also associated with an unfavorable renal hemodynamic profile inde

  1. Pregnancy in renal transplant recipients.

    Science.gov (United States)

    Fuchs, Karin M; Wu, Danny; Ebcioglu, Zeynep

    2007-12-01

    Women with renal disease face increasing infertility and high-risk pregnancy as they approach end-stage renal disease due to uremia. Renal transplantation has provided these patients the ability to return to a better quality of life, and for a number of women who are of child bearing age with renal disease, it has restored their fertility and provided the opportunity to have children. But, although fertility is restored, pregnancy in these women still harbors risk to the mother, graft, and fetus. Selected patients who have stable graft function can have successful pregnancies under the supervision of a multidisciplinary team involving maternal fetal medicine specialists and transplant nephrologists. Careful observation and management are required to optimize outcome for mother and fetus.

  2. Markers of renal function tests

    Directory of Open Access Journals (Sweden)

    Shivaraj Gowda

    2010-04-01

    Full Text Available Background: The markers of renal function test assess the normal functioning of kidneys. These markers may be radioactive and non radioactive. They indicate the glomerular filtration rate, concentrating and diluting capacity of kidneys (tubular function. If there is an increase or decrease in the valves of these markers it indicates dysfunction of kidney. Aim: The aim of this review is to compare and analyze the present and newer markers of renal function tests which help in diagnosis of clinical disorders. Material & Methods: An extensive literature survey was done aiming to compare and compile renal function tests makers required in diagnosis of diseases. Results: Creatinine, urea, uric acid and electrolytes are makers for routine analysis whereas several studies have confirmed and consolidated the usefulness of markers such as cystatin C and β-Trace Protein. Conclusion: We conclude that further investigation is necessary to define these biomarkers in terms of usefulness in assessing renal function.

  3. Medicinal Chemistry Approaches to Heart Regeneration.

    Science.gov (United States)

    Schade, Dennis; Plowright, Alleyn T

    2015-12-24

    Because of the minimal and clearly insufficient ability of the adult heart to regenerate after ischemic injury, there is a great opportunity to identify biological mechanisms, substances, and factors that enhance this process. Hence, innovative therapeutic management of heart failure following infarction requires a paradigm shift in pharmacotherapy. Spurred by tremendous progress in the field of stem cell and cardiac biology, several attractive approaches for regeneration of lost cardiomyocytes and supporting vasculature have emerged. Research in this area focuses on restoring the hearts' original function via proliferation and differentiation of cardiac progenitor cells, proliferation of pre-existing cardiomyocytes, and reprogramming of cardiac fibroblasts. In this review, we outline these principal strategies, putative biological targets or signaling pathways and chemical agents, with a focus on small molecules, to achieve therapeutic heart regeneration. We also point out the many remaining questions and challenges, particularly for translating in vitro discoveries to in vivo application.

  4. Orthopaedic tissue engineering and bone regeneration.

    Science.gov (United States)

    Dickson, Glenn; Buchanan, Fraser; Marsh, David; Harkin-Jones, Eileen; Little, Uel; McCaigue, Mervyn

    2007-01-01

    Orthopaedic tissue engineering combines the application of scaffold materials, cells and the release of growth factors. It has been described as the science of persuading the body to reconstitute or repair tissues that have failed to regenerate or heal spontaneously. In the case of bone regeneration 3-D scaffolds are used as a framework to guide tissue regeneration. Mesenchymal cells obtained from the patient via biopsy are grown on biomaterials in vitro and then implanted at a desired site in the patient's body. Medical implants that encourage natural tissue regeneration are generally considered more desirable than metallic implants that may need to be removed by subsequent intervention. Numerous polymeric materials, from natural and artificial sources, are under investigation as substitutes for skeletal elements such as cartilage and bone. For bone regeneration, cells (obtained mainly from bone marrow aspirate or as primary cell outgrowths from bone biopsies) can be combined with biodegradable polymeric materials and/or ceramics and absorbed growth factors so that osteoinduction is facilitated together with osteoconduction; through the creation of bioactive rather than bioinert scaffold constructs. Relatively rapid biodegradation enables advantageous filling with natural tissue while loss of polymer strength before mass is disadvantageous. Innovative solutions are required to address this and other issues such as the biocompatibility of material surfaces and the use of appropriate scaffold topography and porosity to influence bone cell gene expression.

  5. [Regeneration of airway epithelium].

    Science.gov (United States)

    Adam, D; Perotin, J-M; Lebargy, F; Birembaut, P; Deslée, G; Coraux, C

    2014-04-01

    Epithelial regeneration is a complex process. It can lead to the remodeling of the airway epithelium as in asthma, COPD or cystic fibrosis. The development of in vivo and in vitro models has allowed the analysis of remodeling mechanisms and showed the role of components of extracellular matrix, proteases, cytokines and growth factors. Airway epithelial progenitors and stems cells have been studied in these models. However, their identification remains difficult. Identification and characterization of airway epithelial progenitor/stem-cells, and a better knowledge of the regeneration process may allow the development of new therapeutic strategies for airway epithelial reconstitution. Copyright © 2013 SPLF. Published by Elsevier Masson SAS. All rights reserved.

  6. A Renal Perforating Artery Mistaken for Arterial Bleeding after Percutaneous Renal Biopsy: A Case Report

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Ye Lim; Lee, Chang Hee; Kim, Kyeong Ah; Park, Cheol Min [Korea University College of Medicine, Seoul (Korea, Republic of)

    2009-12-15

    Perirenal hematoma after a renal biopsy is a common complication that usually resolves spontaneously, but this rarely requires transfusions or surgical/radiological intervention. We report here on a case of a renal perforating artery that was mistaken for renal arterial bleeding in a 53-year-old woman who was complicated with perirenal hematoma after undergoing a percutaneous renal biopsy. On the color and pulsed wave Doppler ultrasonography, linear blood flow was seen in the perirenal hematoma, which extended perpendicularly from the renal parenchyma into the perirenal space, and this linear blood flow exhibited an arterial pulse wave. On CT angiography, the renal perforating artery was demonstrated as a curvilinear vessel coursing tangentially to the renal margin and we decided that it was a pseudolesion caused by the renal perforating artery. A renal perforating artery may be mistaken for renal arterial bleeding after a percutaneous renal biopsy. A renal perforating artery and arterial bleeding can be differentiated by the location and shape seen on a color Doppler examination and the pulse waves characteristics

  7. Bilateral Renal Mass-Renal Disorder: Tuberculosis

    Directory of Open Access Journals (Sweden)

    Ozlem Tiryaki

    2013-01-01

    Full Text Available A 30-year-old woman has presented complaining of weakness and fatigue to her primary care physician. The renal sonography is a routine step in the evaluation of new onset renal failure. When the renal masses have been discovered by sonography in this setting, the functional imaging may be critical. We reported a case about bilateral renal masses in a young female patient with tuberculosis and renal insufficiency. Magnetic resonance (MR has revealed the bilateral renal masses in patient, and this patient has been referred to our hospital for further management. The patient’s past medical and surgical history was unremarkable.

  8. Distal renal tubular acidosis

    Science.gov (United States)

    Renal tubular acidosis - distal; Renal tubular acidosis type I; Type I RTA; RTA - distal; Classical RTA ... excreting it into the urine. Distal renal tubular acidosis (Type I RTA) is caused by a defect ...

  9. Proximal renal tubular acidosis

    Science.gov (United States)

    Renal tubular acidosis - proximal; Type II RTA; RTA - proximal; Renal tubular acidosis type II ... by alkaline substances, mainly bicarbonate. Proximal renal tubular acidosis (Type II RTA) occurs when bicarbonate is not ...

  10. Optimization of Energy and Exergy Consumption in MEG Regeneration Processes

    OpenAIRE

    Billington, Henrik Reymert

    2009-01-01

    Monoethylene glycol (MEG) is commonly used for hydrate inhibition in fields that require continuous injection. Traditional processes for regeneration and reclamation of MEG require significant amounts of heat. Reclamation (salt removal) is usually done by complete evaporation of salty MEG in a flash separator under partial vacuum. Regeneration (water removal) is done by distillation. Heat integration in current processes is limited. The oil and gas industry is heading towards energy systems b...

  11. Shoot regeneration from petioles and leaves of Vitis X labruscana 'Catawba'.

    Science.gov (United States)

    Cheng, Z M; Reisch, B I

    1989-10-01

    Shoot regeneration and normal plants were obtained from leaf and petiole explants derived from in vitro grown shoots of Vitis X labruscana 'Catawba'. Regeneration was induced in the presence of both 6-benzylaminopurine and indole-3-butyric acid; combinations of 2,4-dichlorophenoxyacetic acid or 2-naphthoxyacetic acid with 6-benzylaminopurine did not permit regeneration from leaf explants. Up to 15% of leaf and 70% of petiole explants regenerated shoots on media with 5.0-10.0 μM BA and 0.1-0.5 μM IBA. Incubation in the dark was required to obtain regeneration. About 50% of shoots developed normally following transfer to light. An average of one shoot regenerated from leaf explants and 3.3 shoots regenerated per petiole explant. Regeneration from petioles and leaves was always from the basipetal end. The interaction of 6-benzylaminopurine with indole-3-butyric acid was also examined.

  12. Renale Osteopathie

    Directory of Open Access Journals (Sweden)

    Horn S

    2001-01-01

    Full Text Available Die renale Osteopathie umfaßt Erkrankungen des Knochens, die bei Patienten mit chronischen Nierenerkrankungen auftreten, wie den sekundären bzw. tertiären Hyperparathyreoidismus, die adynamische Knochenerkrankung und die Osteopathie nach Nierentransplantation. Durch die Identifikation des Kalzium-Sensing-Rezeptors bzw. des Vitamin D-Rezeptors hat sich unser Verständnis der Zusammenhänge in den letzten Jahren erheblich verbessert. Neue Medikamente versprechen effizientere Prophylaxe- und Therapiemöglichkeiten. Wir beeinflussen dadurch nicht nur die Morbidität und Lebensqualität, sondern auch die Mortalität unserer Patienten.

  13. Periodontal regeneration using strontium-loaded mesoporous bioactive glass scaffolds in osteoporotic rats.

    Directory of Open Access Journals (Sweden)

    Yufeng Zhang

    Full Text Available Recent studies demonstrate that the rate of periodontal breakdown significantly increased in patients compromised from both periodontal disease and osteoporosis. One pharmacological agent used for their treatment is strontium renalate due to its simultaneous ability to increase bone formation and halt bone resorption. The aim of the present study was to achieve periodontal regeneration of strontium-incorporated mesoporous bioactive glass (Sr-MBG scaffolds in an osteoporotic animal model carried out by bilateral ovariectomy (OVX. 15 female Wistar rats were randomly assigned to three groups: control unfilled periodontal defects, 2 MBG alone and 3 Sr-MBG scaffolds. 10 weeks after OVX, bilateral fenestration defects were created at the buccal aspect of the first mandibular molar and assessed by micro-CT and histomorphometric analysis after 28 days. Periodontal fenestration defects treated with Sr-MBG scaffolds showed greater new bone formation (46.67% when compared to MBG scaffolds (39.33% and control unfilled samples (17.50%. The number of TRAP-positive osteoclasts was also significantly reduced in defects receiving Sr-MBG scaffolds. The results from the present study suggest that Sr-MBG scaffolds may provide greater periondontal regeneration. Clinical studies are required to fully characterize the possible beneficial effect of Sr-releasing scaffolds for patients suffering from a combination of both periodontal disease and osteoporosis.

  14. Renal disease in pregnancy.

    Science.gov (United States)

    Thorsen, Martha S; Poole, Judith H

    2002-03-01

    Anatomic and physiologic adaptations within the renal system during pregnancy are significant. Alterations are seen in renal blood flow and glomerular filtration, resulting in changes in normal renal laboratory values. When these normal renal adaptations are coupled with pregnancy-induced complications or preexisting renal dysfunction, the woman may demonstrate a reduction of renal function leading to an increased risk of perinatal morbidity and mortality. This article will review normal pregnancy adaptations of the renal system and discuss common pregnancy-related renal complications.

  15. Infection and Pulp Regeneration

    Directory of Open Access Journals (Sweden)

    Sahng G. Kim

    2016-03-01

    Full Text Available The regeneration of the pulp-dentin complex has been a great challenge to both scientists and clinicians. Previous work has shown that the presence of prior infection may influence the characteristics of tissues formed in the root canal space after regenerative endodontic treatment. The formation of ectopic tissues such as periodontal ligament, bone, and cementum has been observed in the root canal space of immature necrotic teeth with apical periodontitis, while the regeneration of dentin and pulp has been identified in previously non-infected teeth. The current regenerative endodontic therapy utilizes disinfection protocols, which heavily rely on chemical irrigation using conventional disinfectants. From a microbiological point of view, the current protocols may not allow a sufficiently clean root canal microenvironment, which is critical for dentin and pulp regeneration. In this article, the significance of root canal disinfection in regenerating the pulp-dentin complex, the limitations of the current regenerative endodontic disinfection protocols, and advanced disinfection techniques designed to reduce the microorganisms and biofilms in chronic infection are discussed.

  16. Primary Renal Synovial Sarcoma: An Oncologic Surprise

    Directory of Open Access Journals (Sweden)

    H. Krishna Moorthy

    2014-09-01

    Full Text Available Primary renal synovial sarcoma is a rare tumor having a specific chromosomal translocation t(X; 18 (p11.2; q11.2. The clinical features of this tumor and radiologic appearances are quite similar to those of renal cell carcinoma. Confirmatory diagnosis requires fluorescent in situ hybridization or reverse transcriptase polymerase chain reaction validation for differentiating the tumors from sarcomatoid renal cell carcinoma. We present a case of primary renal synovial sarcoma that was diagnosed in a middle-aged man.

  17. Regeneration or replacement? A case report and review of literature.

    Science.gov (United States)

    Farhad, Ali Reza; Shokraneh, Ali; Shekarchizade, Neda

    2016-02-01

    Endodontic treatment of immature necrotic teeth is a real challenge. Recently, a biologically based treatment strategy, referred to as regeneration, has been introduced. Tissue regeneration requires the presence of stems cells, a scaffold, and growth factors. Endodontic regeneration may improve the prognosis of immature necrotic teeth by re-establishing the functional pulpal tissue and further development of the root. However, the tissue formed in the pulpal space may not be original pulp tissue, and in some cases, it may result in uncontrolled calcification of the pulp. This study reports a case of successful endodontic regeneration and compares this process with the normal development of the contralateral tooth. Finally, it discusses the nature of the tissue formed during endodontic regeneration. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  18. Focus on renal congestion in heart failure.

    Science.gov (United States)

    Afsar, Baris; Ortiz, Alberto; Covic, Adrian; Solak, Yalcin; Goldsmith, David; Kanbay, Mehmet

    2016-02-01

    Hospitalizations due to heart failure are increasing steadily despite advances in medicine. Patients hospitalized for worsening heart failure have high mortality in hospital and within the months following discharge. Kidney dysfunction is associated with adverse outcomes in heart failure patients. Recent evidence suggests that both deterioration in kidney function and renal congestion are important prognostic factors in heart failure. Kidney congestion in heart failure results from low cardiac output (forward failure), tubuloglomerular feedback, increased intra-abdominal pressure or increased venous pressure. Regardless of the cause, renal congestion is associated with increased morbidity and mortality in heart failure. The impact on outcomes of renal decongestion strategies that do not compromise renal function should be explored in heart failure. These studies require novel diagnostic markers that identify early renal damage and renal congestion and allow monitoring of treatment responses in order to avoid severe worsening of renal function. In addition, there is an unmet need regarding evidence-based therapeutic management of renal congestion and worsening renal function. In the present review, we summarize the mechanisms, diagnosis, outcomes, prognostic markers and treatment options of renal congestion in heart failure.

  19. PLETHORA Genes Control Regeneration by a Two-Step Mechanism.

    Science.gov (United States)

    Kareem, Abdul; Durgaprasad, Kavya; Sugimoto, Kaoru; Du, Yujuan; Pulianmackal, Ajai J; Trivedi, Zankhana B; Abhayadev, Pazhoor V; Pinon, Violaine; Meyerowitz, Elliot M; Scheres, Ben; Prasad, Kalika

    2015-04-20

    Regeneration, a remarkable example of developmental plasticity displayed by both plants and animals, involves successive developmental events driven in response to environmental cues. Despite decades of study on the ability of the plant tissues to regenerate a complete fertile shoot system after inductive cues, the mechanisms by which cells acquire pluripotency and subsequently regenerate complete organs remain unknown. Here, we show that three PLETHORA (PLT) genes, PLT3, PLT5, and PLT7, regulate de novo shoot regeneration in Arabidopsis by controlling two distinct developmental events. Cumulative loss of function of these three genes causes the intermediate cell mass, callus, to be incompetent to form shoot progenitors, whereas induction of PLT5 or PLT7 can render shoot regeneration hormone-independent. We further show that PLT3, PLT5, and PLT7 establish pluripotency by activating root stem cell regulators PLT1 and PLT2, as reconstitution of either PLT1 or PLT2 in the plt3; plt5-2; plt7 mutant re-established the competence to regenerate shoot progenitor cells but did not lead to the completion of shoot regeneration. PLT3, PLT5, and PLT7 additionally regulate and require the shoot-promoting factor CUP-SHAPED COTYLEDON2 (CUC2) to complete the shoot-formation program. Our findings uncouple the acquisition of competence to regenerate shoot progenitor cells from completion of shoot formation, indicating a two-step mechanism of de novo shoot regeneration that operates in all tested plant tissues irrespective of their origin. Our studies reveal intermediate developmental phases of regeneration and provide a deeper understanding into the mechanistic basis of regeneration. Copyright © 2015 Elsevier Ltd. All rights reserved.

  20. Regeneration of Pelargonium in vitro

    Directory of Open Access Journals (Sweden)

    Agnieszka Wojtania

    2013-12-01

    Full Text Available Pelargonium sp. has been a subject of numerous studies to deterimine the effec tiveness of in vitro techniques to produce a large number of pathogen-free plants. Regeneration of pelargonium plants from the different initial explants as well via organogenesis as via somatic embryogenesis has been obtained. The most effective adventitious shoot formation has been achieved from shoot tips and axillary buds using cytokinin or cytokinin/auxin combinations. Leaf explants, whose general have lower organogenic potency, regenerate better in the presence of thidiazuron. This growth regulator stimulate the somatic embryos production from hypocotyl and cotyledone explants too. The main problem in tissue culture propagation of Pelargonium has been the high tendency to formation of vigorously growing callus with low organogenic potency and rapid senescence of cultures. Moreover, the significant differen ces in requirements to the medium composition (minerals, organic compounds and growth regulators between Pelargonium cultivars has been observed. This makes difficult to develop an universaI method of Pelargonium micropropagation.

  1. Collagen for bone tissue regeneration.

    Science.gov (United States)

    Ferreira, Ana Marina; Gentile, Piergiorgio; Chiono, Valeria; Ciardelli, Gianluca

    2012-09-01

    In the last decades, increased knowledge about the organization, structure and properties of collagen (particularly concerning interactions between cells and collagen-based materials) has inspired scientists and engineers to design innovative collagen-based biomaterials and to develop novel tissue-engineering products. The design of resorbable collagen-based medical implants requires understanding the tissue/organ anatomy and biological function as well as the role of collagen's physicochemical properties and structure in tissue/organ regeneration. Bone is a complex tissue that plays a critical role in diverse metabolic processes mediated by calcium delivery as well as in hematopoiesis whilst maintaining skeleton strength. A wide variety of collagen-based scaffolds have been proposed for different tissue engineering applications. These scaffolds are designed to promote a biological response, such as cell interaction, and to work as artificial biomimetic extracellular matrices that guide tissue regeneration. This paper critically reviews the current understanding of the complex hierarchical structure and properties of native collagen molecules, and describes the scientific challenge of manufacturing collagen-based materials with suitable properties and shapes for specific biomedical applications, with special emphasis on bone tissue engineering. The analysis of the state of the art in the field reveals the presence of innovative techniques for scaffold and material manufacturing that are currently opening the way to the preparation of biomimetic substrates that modulate cell interaction for improved substitution, restoration, retention or enhancement of bone tissue function.

  2. Cellular localization of uranium in the renal proximal tubules during acute renal uranium toxicity.

    Science.gov (United States)

    Homma-Takeda, Shino; Kitahara, Keisuke; Suzuki, Kyoko; Blyth, Benjamin J; Suya, Noriyoshi; Konishi, Teruaki; Terada, Yasuko; Shimada, Yoshiya

    2015-12-01

    Renal toxicity is a hallmark of uranium exposure, with uranium accumulating specifically in the S3 segment of the proximal tubules causing tubular damage. As the distribution, concentration and dynamics of accumulated uranium at the cellular level is not well understood, here, we report on high-resolution quantitative in situ measurements by high-energy synchrotron radiation X-ray fluorescence analysis in renal sections from a rat model of uranium-induced acute renal toxicity. One day after subcutaneous administration of uranium acetate to male Wistar rats at a dose of 0.5 mg uranium kg(-1) body weight, uranium concentration in the S3 segment of the proximal tubules was 64.9 ± 18.2 µg g(-1) , sevenfold higher than the mean renal uranium concentration (9.7 ± 2.4 µg g(-1) ). Uranium distributed into the epithelium of the S3 segment of the proximal tubules and highly concentrated uranium (50-fold above mean renal concentration) in micro-regions was found near the nuclei. These uranium levels were maintained up to 8 days post-administration, despite more rapid reductions in mean renal concentration. Two weeks after uranium administration, damaged areas were filled with regenerating tubules and morphological signs of tissue recovery, but areas of high uranium concentration (100-fold above mean renal concentration) were still found in the epithelium of regenerating tubules. These data indicate that site-specific accumulation of uranium in micro-regions of the S3 segment of the proximal tubules and retention of uranium in concentrated areas during recovery are characteristics of uranium behavior in the kidney.

  3. Stimulating endogenous cardiac regeneration

    Directory of Open Access Journals (Sweden)

    Amanda eFinan

    2015-09-01

    Full Text Available The healthy adult heart has a low turnover of cardiac myocytes. The renewal capacity, however, is augmented after cardiac injury. Participants in cardiac regeneration include cardiac myocytes themselves, cardiac progenitor cells, and peripheral stem cells, particularly from the bone marrow compartment. Cardiac progenitor cells and bone marrow stem cells are augmented after cardiac injury, migrate to the myocardium, and support regeneration. Depletion studies of these populations have demonstrated their necessary role in cardiac repair. However, the potential of these cells to completely regenerate the heart is limited. Efforts are now being focused on ways to augment these natural pathways to improve cardiac healing, primarily after ischemic injury but in other cardiac pathologies as well. Cell and gene therapy or pharmacological interventions are proposed mechanisms. Cell therapy has demonstrated modest results and has passed into clinical trials. However, the beneficial effects of cell therapy have primarily been their ability to produce paracrine effects on the cardiac tissue and recruit endogenous stem cell populations as opposed to direct cardiac regeneration. Gene therapy efforts have focused on prolonging or reactivating natural signaling pathways. Positive results have been demonstrated to activate the endogenous stem cell populations and are currently being tested in clinical trials. A potential new avenue may be to refine pharmacological treatments that are currently in place in the clinic. Evidence is mounting that drugs such as statins or beta blockers may alter endogenous stem cell activity. Understanding the effects of these drugs on stem cell repair while keeping in mind their primary function may strike a balance in myocardial healing. To maximize endogenous cardiac regeneration,a combination of these approaches couldameliorate the overall repair process to incorporate the participation ofmultiple cell players.

  4. How renal cells handle urea.

    Science.gov (United States)

    Bagnasco, S M

    2000-01-01

    The urine concentration process requires an osmolality gradient along the renal cortico-medullary axis, with highest values in the renal papilla. NaCl and urea are the major solutes in the renal inner medulla, concentrations of urea up to 500-600 mM are found in the rat renal papilla. Urea can diffuse across cell membranes and contributes to balance intracellular and extracellular osmotic equilibrium. However, urea has perturbing effects on enzyme activity, and in concentrations above 300 mM is toxic for renal cultured cells. There is increasing evidence that urea can induce cellular responses distinct from those due to NaCl and other non-permeable solutes, including upregulation of immediate-early genes (IEGs). Urea transport by epithelial and endothelial cells is important for intra-medullary urea recycling and preservation of high urea concentration in the inner medulla. Trans-cellular movement of urea in cells expressing urea transporters may influence intracellular levels of this solute and modulate urea-induced signaling pathways. Regulation of urea transporters expression and activity can therefore be viewed as one aspect of cellular adaptation to urea. We have identified tonicity-responsive transcription as one mechanism regulating expression of the urea transporter UT-A. The short-term and long-term effects of variable extracellular urea concentration on the function of renal cells remain still unclear.

  5. Renal calculus

    CERN Document Server

    Pyrah, Leslie N

    1979-01-01

    Stone in the urinary tract has fascinated the medical profession from the earliest times and has played an important part in the development of surgery. The earliest major planned operations were for the removal of vesical calculus; renal and ureteric calculi provided the first stimulus for the radiological investigation of the viscera, and the biochemical investigation of the causes of calculus formation has been the training ground for surgeons interested in metabolic disorders. It is therefore no surprise that stone has been the subject of a number of monographs by eminent urologists, but the rapid development of knowledge has made it possible for each one of these authors to produce something new. There is still a technical challenge to the surgeon in the removal of renal calculi, and on this topic we are always glad to have the advice of a master craftsman; but inevitably much of the interest centres on the elucidation of the causes of stone formation and its prevention. Professor Pyrah has had a long an...

  6. Limb regeneration: a new development?

    Science.gov (United States)

    Nacu, Eugen; Tanaka, Elly M

    2011-01-01

    Salamander limb regeneration is a classical model of tissue morphogenesis and patterning. Through recent advances in cell labeling and molecular analysis, a more precise, mechanistic understanding of this process has started to emerge. Long-standing questions include to what extent limb regeneration recapitulates the events observed in mammalian limb development and to what extent are adult- or salamander- specific aspects deployed. Historically, researchers studying limb development and limb regeneration have proposed different models of pattern formation. Here we discuss recent data on limb regeneration and limb development to argue that although patterning mechanisms are likely to be similar, cell plasticity and signaling from nerves play regeneration-specific roles.

  7. Microwave-Regenerated Diesel Exhaust Particulate Filter

    Energy Technology Data Exchange (ETDEWEB)

    Nixdorf, Richard D. (Industrial Ceramic Solution, LLC); Green, Johney Boyd; Story, John M.; Wagner, Robert M. (Oak Ridge National Laboratory)

    2001-03-05

    Development of a microwave-regenerated particulate filter system has evolved from bench scale work to actual diesel engine experimentation. The filter system was initially evaluated on a stationary mounted 1.2-L diesel engine and was able to remove a significant amount of carbon particles from the exhaust. The ability of the microwave energy to regenerate or clean the filter was also demonstrated on this engine under idle conditions. Based on the 1.2-L experiments, improvements to the filter design and materials were implemented and the system was re-evaluated on a vehicle equipped with a 7.3-L diesel engine. The 7.3-L engine was selected to achieve heavy filter loading in a relatively short period of time. The purpose of these experiments was to evaluate filter-loading capacity, power requirements for regeneration, and filter regeneration efficiency. A more detailed evaluation of the filter was performed on a stationary mounted 1.9-L diesel engine. The effect of exhaust flow rate, loading, transients, and regeneration on filter efficiency was evaluated with this setup. In addition, gaseous exhaust emissions were investigated with and without an oxidation catalyst on the filter cartridge during loading and regeneration. (SAE Paper SAE-2001-01-0903 © 2001 SAE International. This paper is published on this website with permission from SAE International. As a user of this website, you are permitted to view this paper on-line, download this pdf file and print one copy of this paper at no cost for your use only. The downloaded pdf file and printout of this SAE paper may not be copied, distributed or forwarded to others or for the use of others.)

  8. Retrograde Renal Cooling to Minimize Ischemia

    Directory of Open Access Journals (Sweden)

    Janet L. Colli

    2013-01-01

    Full Text Available Objective: During partial nephrectomy, renal hypothermia has been shown to decrease ischemia induced renal damage which occurs from renal hilar clamping. In this study we investigate the infusion rate required to safely cool the entire renal unit in a porcine model using retrograde irrigation of iced saline via dual-lumen ureteral catheter. Materials and Methods: Renal cortical, renal medullary, bowel and rectal temperatures during retrograde cooling in a laparoscopic porcine model were monitored in six renal units. Iced normal saline was infused at 300 cc/hour, 600 cc/hour, 1000 cc/hour and gravity (800 cc/hour for 600 seconds with and without hilar clamping. Results: Retrograde cooling with hilar clamping provided rapid medullary renal cooling and significant hypothermia of the medulla and cortex at infusion rates ≥ 600 cc/hour. With hilar clamping, cortical temperatures decreased at -0.9° C/min. reaching a threshold temperature of 26.9° C, and medullary temperatures decreased at -0.90 C/min. reaching a temperature of 26.1° C over 600 seconds on average for combined data at infusion rates ≥ 600 cc/hour. The lowest renal temperatures were achieved with gravity infusion. Without renal hilum clamping, retrograde cooling was minimal at all infusion rates. Conclusions: Significant renal cooling by gravity infusion of iced cold saline via a duel lumen catheter with a clamped renal hilum was achieved in a porcine model. Continuous retrograde irrigation with iced saline via a two way ureteral catheter may be an effective method to induce renal hypothermia in patients undergoing robotic assisted and/or laparoscopic partial nephrectomy.

  9. Precise control of miR-125b levels is required to create a regeneration-permissive environment after spinal cord injury: a cross-species comparison between salamander and rat.

    Science.gov (United States)

    Diaz Quiroz, Juan Felipe; Tsai, Eve; Coyle, Matthew; Sehm, Tina; Echeverri, Karen

    2014-06-01

    Most spinal cord injuries lead to permanent paralysis in mammals. By contrast, the remarkable regenerative abilities of salamanders enable full functional recovery even from complete spinal cord transections. The molecular differences underlying this evolutionary divergence between mammals and amphibians are poorly understood. We focused on upstream regulators of gene expression as primary entry points into this question. We identified a group of microRNAs (miRNAs) that are conserved between the Mexican axolotl salamander (Ambystoma mexicanum) and mammals but show marked cross-species differences in regulation patterns following spinal cord injury. We found that precise post-injury levels of one of these miRNAs (miR-125b) is essential for functional recovery, and guides correct regeneration of axons through the lesion site in a process involving the direct downstream target Sema4D in axolotls. Translating these results to a mammalian model, we increased miR-125b levels in the rat through mimic treatments following spinal cord transection. These treatments downregulated Sema4D and other glial-scar-related genes, and enhanced the animal's functional recovery. Our study identifies a key regulatory molecule conserved between salamander and mammal, and shows that the expression of miR-125b and Sema4D must be carefully controlled in the right cells at the correct level to promote regeneration. We also show that these molecular components of the salamander's regeneration-permissive environment can be experimentally harnessed to improve treatment outcomes for mammalian spinal cord injuries.

  10. Renal actinomycosis with concomitant renal vein thrombosis.

    Science.gov (United States)

    Chang, Dong-Suk; Jang, Won Ik; Jung, Ji Yoon; Chung, Sarah; Choi, Dae Eun; Na, Ki-Ryang; Lee, Kang Wook; Shin, Yong-Tai

    2012-02-01

    Renal actinomycosis is a rare infection caused by fungi of the genus Actinomyces. A 74-year-old male was admitted to our hospital because of gross hematuria with urinary symptoms and intermittent chills. Computed tomography of the abdomen showed thrombosis in the left renal vein and diffuse, heterogeneous enlargement of the left kidney. After nephrectomy, sulfur granules with chronic suppurative inflammation were seen microscopically, and the histopathological diagnosis was renal actinomycosis. Our case is the first report of renal actinomycosis with renal vein thrombosis.

  11. TRANSPLANTE RENAL

    Directory of Open Access Journals (Sweden)

    Soraia Geraldo Rozza Lopes

    2014-01-01

    Full Text Available El objetivo del estudio fue comprender el significado de espera del trasplante renal para las mujeres en hemodiálisis. Se trata de un estudio cualitativo-interpretativo, realizado con 12 mujeres en hemodiálisis en Florianópolis. Los datos fueron recolectados a través de entrevistas en profundidad en el domicilio. Fue utilizado el software Etnografh 6.0 para la pre-codificación y posterior al análisis interpretativo emergieron dos categorías: “las sombras del momento actual”, que mostró que las dificultades iniciales de la enfermedad están presentes, pero las mujeres pueden hacer frente mejor a la enfermedad y el tratamiento. La segunda categoría, “la luz del trasplante renal”, muestra la esperanza impulsada por la entrada en la lista de espera para un trasplante.

  12. Renal failure

    Institute of Scientific and Technical Information of China (English)

    1993-01-01

    930564 Dwell times affect the local host de-fence mechanism of peritoneal dialysis patients.WANG Tao(汪涛),et al.Renal Instit,SunYatsen Med Univ,Guangzhou,510080.Chin JNephrol 1993;9(2):75—77.The effect of different intraperitoneal awelltimes on the local host defence in 6 peritonealdialysis patients was studied.A significant de-crease in the number of peritoneal cells,IgG con-centration and the phagoeytosis and bactericidalactivity of macrophages was determined when thedwell time decreased from 12 to 4 hs or form 4 to0.5hs,but the peroxidase activity in macrophagesincreased significantly.All variables,except theperoxidase activity in macrophages,showed nosignificant difference between patients of high or

  13. Traumatismo renal

    OpenAIRE

    Rocha, Sofia Rosa Moura Gomes da

    2009-01-01

    Introdução: A realização deste trabalho visa a elaboração de uma revisão sistematizada subordinada à temática da traumatologia renal. Objectivos: Os principais objectivos deste trabalho são: apurar a etiologia, definir a classificação, analisar o diagnóstico e expôr o tratamento e as complicações. Desenvolvimento: Os traumatismos são a principal causa de morte antes dos 40 anos. O rim é o órgão do aparelho génito-urinário mais frequentemente atingido. Os traumatismos renais são mais fre...

  14. Regulation of p53 is critical for vertebrate limb regeneration.

    Science.gov (United States)

    Yun, Maximina H; Gates, Phillip B; Brockes, Jeremy P

    2013-10-22

    Extensive regeneration of the vertebrate body plan is found in salamander and fish species. In these organisms, regeneration takes place through reprogramming of differentiated cells, proliferation, and subsequent redifferentiation of adult tissues. Such plasticity is rarely found in adult mammalian tissues, and this has been proposed as the basis of their inability to regenerate complex structures. Despite their importance, the mechanisms underlying the regulation of the differentiated state during regeneration remain unclear. Here, we analyzed the role of the tumor-suppressor p53 during salamander limb regeneration. The activity of p53 initially decreases and then returns to baseline. Its down-regulation is required for formation of the blastema, and its up-regulation is necessary for the redifferentiation phase. Importantly, we show that a decrease in the level of p53 activity is critical for cell cycle reentry of postmitotic, differentiated cells, whereas an increase is required for muscle differentiation. In addition, we have uncovered a potential mechanism for the regulation of p53 during limb regeneration, based on its competitive inhibition by ΔNp73. Our results suggest that the regulation of p53 activity is a pivotal mechanism that controls the plasticity of the differentiated state during regeneration.

  15. Detection of acute renal allograft rejection by analysis of renal tissue proteomics in rat models of renal transplantation

    Directory of Open Access Journals (Sweden)

    Dai Yong

    2008-01-01

    Full Text Available At present, the diagnosis of renal allograft rejection requires a renal biopsy. Clinical management of renal transplant patients would be improved if rapid, noninvasive and reliable biomarkers of rejection were available. This study is designed to determine whether such protein biomarkers can be found in renal-graft tissue proteomic approach. Orthotopic kidney transplantations were performed using Fisher (F344 or Lewis rats as donors and Lewis rats as recipients. Hence, there were two groups of renal transplant models: one is allograft (from F344 to Lewis rats; another is syngrafts (from Lewis to Lewis rats serving as control. Renal tissues were collected 3, 7 and 14 days after transplantation. As many as 18 samples were analyzed by 2-D Electrophoresis and mass spectrometry (MALDI-TOF-TOF-MS. Eleven differentially expressed proteins were identified between groups. In conclusion, proteomic technology can detect renal tissue proteins associated with acute renal allograft rejection. Identification of these proteins as diagnostic markers for rejection in patients′ urine or sera may be useful and non-invasive, and these proteins might serve as novel therapeutic targets that also help to improve the understanding of mechanism of renal rejection.

  16. Biomaterials for cardiac regeneration

    CERN Document Server

    Ruel, Marc

    2015-01-01

    This book offers readers a comprehensive biomaterials-based approach to achieving clinically successful, functionally integrated vasculogenesis and myogenesis in the heart. Coverage is multidisciplinary, including the role of extracellular matrices in cardiac development, whole-heart tissue engineering, imaging the mechanisms and effects of biomaterial-based cardiac regeneration, and autologous bioengineered heart valves. Bringing current knowledge together into a single volume, this book provides a compendium to students and new researchers in the field and constitutes a platform to allow for future developments and collaborative approaches in biomaterials-based regenerative medicine, even beyond cardiac applications. This book also: Provides a valuable overview of the engineering of biomaterials for cardiac regeneration, including coverage of combined biomaterials and stem cells, as well as extracellular matrices Presents readers with multidisciplinary coverage of biomaterials for cardiac repair, including ...

  17. Tissue regeneration with photobiomodulation

    Science.gov (United States)

    Tang, Elieza G.; Arany, Praveen R.

    2013-03-01

    Low level light therapy (LLLT) has been widely reported to reduce pain and inflammation and enhance wound healing and tissue regeneration in various settings. LLLT has been noted to have both stimulatory and inhibitory biological effects and these effects have been termed Photobiomodulation (PBM). Several elegant studies have shown the key role of Cytochrome C oxidase and ROS in initiating this process. The downstream biological responses remain to be clearly elucidated. Our work has demonstrated activation of an endogenous latent growth factor complex, TGF-β1, as one of the major biological events in PBM. TGF-β1 has critical roles in various biological processes especially in inflammation, immune responses, wound healing and stem cell biology. This paper overviews some of the studies demonstrating the efficacy of PBM in promoting tissue regeneration.

  18. Low Temperature Regenerator Study.

    Science.gov (United States)

    1979-08-01

    effect. The idealized cycle achieves the same theoretical coefficient of performance (COP) as the theoretical Carnot cycle , whose limiting performance...DISTRIBUTION STATEMENT (of the abstract *irt.,ed in Block 20, iI different it oe) I8. SUPPLEMENTARY NOTES I9. KEY WORDS (Continute on reverse @do of noco*oy...PERFORMANCE ............ 64 3.1 Introduction ..... 0 ... . ......... ... . 64 3.2 Stirling Cycle Analysis ................. 71 3.2.1 Simple Regenerator Model

  19. Regeneration of Optic Nerve

    Directory of Open Access Journals (Sweden)

    Kwok-Fai So

    2011-05-01

    Full Text Available The optic nerve is part of the central nervous system (CNS and has a structure similar to other CNS tracts. The axons that form the optic nerve originate in the ganglion cell layer of the retina and extend through the optic tract. As a tissue, the optic nerve has the same organization as the white matter of the brain in regard to its glia. There are three types of glial cells: Oligodendrocytes, astrocytes, and microglia. Little structural and functional regeneration of the CNS takes place spontaneously following injury in adult mammals. In contrast, the ability of the mammalian peripheral nervous system (PNS to regenerate axons after injury is well documented. A number of factors are involved in the lack of CNS regeneration, including: (i the response of neuronal cell bodies against the damage; (ii myelin-mediated inhibition by oligodendrocytes; (iii glial scarring, by astrocytes; (iv macrophage infiltration; and (v insufficient trophic factor support. The fundamental difference in the regenerative capacity between CNS and PNS neuronal cell bodies has been the subject of intensive research. In the CNS the target normally conveys a retrograde trophic signal to the cell body. CNS neurons die because of trophic deprivation. Damage to the optic nerve disconnects the neuronal cell body from its target-derived trophic peptides, leading to the death of retinal ganglion cells. Furthermore, the axontomized neurons become less responsive to the peptide trophic signals they do receive. On the other hand, adult PNS neurons are intrinsically responsive to neurotrophic factors and do not lose trophic responsiveness after axotomy. In this talk different strategies to promote optic-nerve regeneration in adult mammals are reviewed. Much work is still needed to resolve many issues. This is a very important area of neuroregeneration and neuroprotection, as currently there is no cure after traumatic optic nerve injury or retinal disease such as glaucoma, which

  20. Percutaneous coronary intervention versus coronary artery bypass grafting in patients with end-stage renal disease requiring dialysis (5-year outcomes of the CREDO-Kyoto PCI/CABG Registry Cohort-2).

    Science.gov (United States)

    Marui, Akira; Kimura, Takeshi; Nishiwaki, Noboru; Mitsudo, Kazuaki; Komiya, Tatsuhiko; Hanyu, Michiya; Shiomi, Hiroki; Tanaka, Shiro; Sakata, Ryuzo

    2014-08-15

    Ischemic heart disease is a major risk factor for morbidity and mortality in patients with end-stage renal disease. However, long-term benefits of percutaneous coronary intervention (PCI) relative to coronary artery bypass grafting (CABG) in those patients is still unclear in the drug-eluting stent era. We identified 388 patients with multivessel and/or left main disease with end-stage renal disease requiring dialysis among 15,939 patients undergoing first coronary revascularization enrolled in the Coronary REvascularization Demonstrating Outcome Study in Kyoto PCI/CABG Registry Cohort-2 (PCI: 258 patients and CABG: 130 patients). The CABG group included more patients with 3-vessel (38% vs 57%, p <0.001) and left main disease (10% vs 34%, p <0.001). Preprocedural Synergy between Percutaneous Coronary Intervention with Taxus and Cardiac Surgery score in the CABG group was significantly higher than that in the PCI group (23.5 ± 8.7 vs 29.4 ± 11.0, p <0.001). Unadjusted 30-day mortality was 2.7% for PCI and 5.4% for CABG. Cumulative 5-year all-cause mortality was 52.3% for PCI and 49.9% for CABG. Propensity score-adjusted all-cause mortality was not different between PCI and CABG (hazard ratio [HR] 1.33, 95% confidence interval [CI] 0.85 to 2.09, p = 0.219). However, the excess risk of PCI relative to CABG for cardiac death was significant (HR 2.10, 95% CI 1.11 to 3.96, p = 0.02). The risk of sudden death was also higher after PCI (HR 4.83, 95% CI 1.01 to 23.08, p = 0.049). The risk of myocardial infarction after PCI tended to be higher than after CABG (HR 3.30, 95% CI 0.72 to 15.09, p = 0.12). The risk of any coronary revascularization after PCI was markedly higher after CABG (HR 3.78, 95% CI 1.91 to 7.50, p <0.001). Among the 201 patients who died during the follow-up, 94 patients (47%) died from noncardiac morbidities such as stroke, respiratory failure, and renal failure. In patients with multivessel and/or left main disease undergoing dialysis, 5-year

  1. ISLET FORMATION AND REGENERATION

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Objective To explore the mechanisms of differentiation and development of pancreatic endocrine cells as well as pancreatic regeneration. Methods Human embryonic pancreatic tissue at 7-14 weeks of gestation was collected. Diabetes mellitus rat model was induced with 65 mg/kg of streptozotocin. Insulin, glucagon, somatostatin, nestin, and cytokeratin 19 (CK19)of pancreatic tissues were observed by immunohistochemistry. Results At 9 weeks of gestation, pancreatic epithelial cells began to co-express insulin, glucagon, somatostatin, and CK19 before migration. Islet cells gradually congregated along with the increase of aging, and at 14 weeks of gestation histological examination showed islet formation. At 12 weeks of gestation, nestin-positive cells could be seen in the pancreatic mesenchyme. During early embryogenesis, islet cells of pancreatic ducts co-expressed insulin, glucagon, and somatostatin. During pancreatic regeneration after damage, nestin expression of islet cells increased. Conclusion In the early stage of embryogenesis, islet cells of primary pancreatic ducts can be differentiated to multipotential endocrine cells before migration. During tissue regeneration, pancreatic stem cells may differentiate and proliferate to form pancreatic islet.

  2. Renal Primordia Activate Kidney Regenerative Events in a Rat Model of Progressive Renal Disease

    Science.gov (United States)

    Imberti, Barbara; Corna, Daniela; Rizzo, Paola; Xinaris, Christodoulos; Abbate, Mauro; Longaretti, Lorena; Cassis, Paola; Benedetti, Valentina; Benigni, Ariela; Zoja, Carlamaria; Remuzzi, Giuseppe; Morigi, Marina

    2015-01-01

    New intervention tools for severely damaged kidneys are in great demand to provide patients with a valid alternative to whole organ replacement. For repairing or replacing injured tissues, emerging approaches focus on using stem and progenitor cells. Embryonic kidneys represent an interesting option because, when transplanted to sites such as the renal capsule of healthy animals, they originate new renal structures. Here, we studied whether metanephroi possess developmental capacity when transplanted under the kidney capsule of MWF male rats, a model of spontaneous nephropathy. We found that six weeks post-transplantation, renal primordia developed glomeruli and tubuli able to filter blood and to produce urine in cyst-like structures. Newly developed metanephroi were able to initiate a regenerative-like process in host renal tissues adjacent to the graft in MWF male rats as indicated by an increase in cell proliferation and vascular density, accompanied by mRNA and protein upregulation of VEGF, FGF2, HGF, IGF-1 and Pax-2. The expression of SMP30 and NCAM was induced in tubular cells. Oxidative stress and apoptosis markedly decreased. Our study shows that embryonic kidneys generate functional nephrons when transplanted into animals with severe renal disease and at the same time activate events at least partly mimicking those observed in kidney tissues during renal regeneration. PMID:25811887

  3. Renal stem cells and their implications for kidney cancer.

    Science.gov (United States)

    Axelson, Håkan; Johansson, Martin E

    2013-02-01

    The renal cell carcinomas (RCC) denote a diverse set of neoplasias with unique genetic and histological features. The RCCs emanate from the renal tubule, a highly heterogeneous epithelial structure, and depending on which cell is malignified the resulting cancer displays unique characteristics. Notwithstanding this, the cells of origin for the RCC forms are far from established, and only inferred by the accumulated weight of marker similarities, not always providing an unequivocal picture. The tubular epithelium is normally mitotically quiescent, but demonstrates a considerable regenerative capacity upon renal injury. Recently the hypothesis that regeneration is driven by adult stem cells has been added experimental support, providing further complexity to the issue of renal carcinogenesis. Whether these cells are linked to RCC is an open question. In the present review we therefore present the prevailing theories regarding kidney regeneration, since a better understanding of this process might be of relevance when considering the different malignancies that arise from kidney epithelium. Our own results show that papillary renal cell carcinoma displays considerable similarities to proximal tubular progenitor cells and we suggest that this tumor form may develop in a multi-step fashion via benign renal adenomas. The putative connection between renal stem cells and carcinomas is, however, not clarified, since the current understanding of the renal stem cell system is not complete. It is clear that the efforts to isolate and characterize renal progenitor/stem cells suffer from numerous technical limitations and that it remains likely that the kidney harbors different stem cell pools with a restricted differentiation potential.

  4. Bone regeneration: current concepts and future directions

    Directory of Open Access Journals (Sweden)

    McGonagle Dennis

    2011-05-01

    Full Text Available Abstract Bone regeneration is a complex, well-orchestrated physiological process of bone formation, which can be seen during normal fracture healing, and is involved in continuous remodelling throughout adult life. However, there are complex clinical conditions in which bone regeneration is required in large quantity, such as for skeletal reconstruction of large bone defects created by trauma, infection, tumour resection and skeletal abnormalities, or cases in which the regenerative process is compromised, including avascular necrosis, atrophic non-unions and osteoporosis. Currently, there is a plethora of different strategies to augment the impaired or 'insufficient' bone-regeneration process, including the 'gold standard' autologous bone graft, free fibula vascularised graft, allograft implantation, and use of growth factors, osteoconductive scaffolds, osteoprogenitor cells and distraction osteogenesis. Improved 'local' strategies in terms of tissue engineering and gene therapy, or even 'systemic' enhancement of bone repair, are under intense investigation, in an effort to overcome the limitations of the current methods, to produce bone-graft substitutes with biomechanical properties that are as identical to normal bone as possible, to accelerate the overall regeneration process, or even to address systemic conditions, such as skeletal disorders and osteoporosis.

  5. Human stem cells and articular cartilage regeneration.

    Science.gov (United States)

    Inui, Atsuyuki; Iwakura, Takashi; Reddi, A Hari

    2012-11-05

    The regeneration of articular cartilage damaged due to trauma and posttraumatic osteoarthritis is an unmet medical need. Current approaches to regeneration and tissue engineering of articular cartilage include the use of chondrocytes, stem cells, scaffolds and signals, including morphogens and growth factors. Stem cells, as a source of cells for articular cartilage regeneration, are a critical factor for articular cartilage regeneration. This is because articular cartilage tissue has a low cell turnover and does not heal spontaneously. Adult stem cells have been isolated from various tissues, such as bone marrow, adipose, synovial tissue, muscle and periosteum. Signals of the transforming growth factor beta superfamily play critical roles in chondrogenesis. However, adult stem cells derived from various tissues tend to differ in their chondrogenic potential. Pluripotent stem cells have unlimited proliferative capacity compared to adult stem cells. Chondrogenesis from embryonic stem (ES) cells has been studied for more than a decade. However, establishment of ES cells requires embryos and leads to ethical issues for clinical applications. Induced pluripotent stem (iPS) cells are generated by cellular reprogramming of adult cells by transcription factors. Although iPS cells have chondrogenic potential, optimization, generation and differentiation toward articular chondrocytes are currently under intense investigation.

  6. Human Stem Cells and Articular Cartilage Regeneration

    Directory of Open Access Journals (Sweden)

    A. Hari Reddi

    2012-11-01

    Full Text Available  The regeneration of articular cartilage damaged due to trauma and posttraumatic osteoarthritis is an unmet medical need. Current approaches to regeneration and tissue engineering of articular cartilage include the use of chondrocytes, stem cells, scaffolds and signals, including morphogens and growth factors. Stem cells, as a source of cells for articular cartilage regeneration, are a critical factor for articular cartilage regeneration. This is because articular cartilage tissue has a low cell turnover and does not heal spontaneously. Adult stem cells have been isolated from various tissues, such as bone marrow, adipose, synovial tissue, muscle and periosteum. Signals of the transforming growth factor beta superfamily play critical roles in chondrogenesis. However, adult stem cells derived from various tissues tend to differ in their chondrogenic potential. Pluripotent stem cells have unlimited proliferative capacity compared to adult stem cells. Chondrogenesis from embryonic stem (ES cells has been studied for more than a decade. However, establishment of ES cells requires embryos and leads to ethical issues for clinical applications. Induced pluripotent stem (iPS cells are generated by cellular reprogramming of adult cells by transcription factors. Although iPS cells have chondrogenic potential, optimization, generation and differentiation toward articular chondrocytes are currently under intense investigation.

  7. Trasplante renal Kidney transplant

    Directory of Open Access Journals (Sweden)

    P. Martín

    2006-08-01

    Full Text Available El trasplante renal es la terapia de elección para la mayoría de las causas de insuficiencia renal crónica terminal porque mejora la calidad de vida y la supervivencia frente a la diálisis. El trasplante renal de donante vivo es una excelente alternativa para el paciente joven en situación de prediálisis porque ofrece mejores resultados. El tratamiento inmunosupresor debe ser individualizado buscando la sinergia inmunosupresora y el mejor perfil de seguridad, y debe adaptarse a las diferentes etapas del trasplante renal. En el seguimiento del trasplante renal hay que tener muy en cuenta los factores de riesgo cardiovascular y los tumores puesto que la muerte del paciente con injerto funcionante es la segunda causa de pérdida del injerto tras el primer año del trasplante. La función alterada del injerto es un factor de mortalidad cardiovascular independiente que requerirá seguimiento y control de todas sus complicaciones para retrasar la entrada en diálisis.The kidney transplant is the therapy of choice for the majority of the causes of chronic terminal kidney insufficiency, because it improves the quality of life and survival in comparison with dialysis. A kidney transplant from a live donor is an excellent alternative for the young patient in a state of pre-dialysis because it offers the best results. Immunosuppressive treatment must be individualised, seeking immunosuppressive synergy and the best safety profile, and must be adapted to the different stages of the kidney transplant. In the follow-up to the kidney transplant, cardiovascular risk factors and tumours must be especially taken into account, given that the death of the patient with a working graft is the second cause of loss of the graft following the first year of the transplant. The altered function of the graft is a factor of independent cardiovascular mortality that will require follow-up and the control of all its complications to postpone the entrance in dialysis.

  8. A novel osteogenesis technique: The expansible guided bone regeneration

    OpenAIRE

    Osama Zakaria; Marwa Madi; Shohei Kasugai

    2012-01-01

    Guided bone regeneration is a unique osteogenesis technique that requires a barrier membrane under periosteum to create space for bone regeneration. However, creating sizeable spaces is clinically not commonly feasible. A titanium plate and a thin silicone membrane were surgically layered on each calvaria of eight rabbits. Then, the periphery of the silicone membrane was fixed by a plastic ring to the underlying bone u...

  9. Use of biosynthetic cellulose membrane in the guided tissue regeneration

    OpenAIRE

    Iamaguti, Luciana Santini; Universidade Estadual Paulista; Brandão, Cláudia Valéria Seullner; Universidade Estadual Paulista

    2007-01-01

    Guided Tissue Regeneration (GTR) is a regenerative treatment modality that requires the placement of a physical barrier over a bone defect in such a way that the proliferation of the surrounding soft tissues into the barrier-protected area is prevented. Thereby in the guided osseous regeneration allowing boneforming cells from the existent bone edges to invade the space and produce bone. The physical barriers should be biocompatible, allow cellular occlusion, maintain adequate space, tissue i...

  10. Regeneration of begonia plantlets by direct organogenesis

    OpenAIRE

    Mendi, Yalçın Y.; Mendi, Yalcin Y.; Curuk, P.; Kocaman, E.; Unek, C.; Eldoğan, S.; Eldogan, S.; Gencel, G.; Çetiner, Selim; Cetiner, Selim

    2009-01-01

    The economic importance of ornamentals worldwide suggests a bright future for ornamental breeding. Rapid progress in plant molecular biology has great potentials to contribute to the breeding of novel ornamental plants utilizing recombinant DNA technology. The plant cell, tissue or organ culture of many ornamental species and their regeneration are essential for providing the material and systems for their genetic manipulation, and this is therefore the first requirement of genetic engineerin...

  11. Precise control of miR-125b levels is required to create a regeneration-permissive environment after spinal cord injury: a cross-species comparison between salamander and rat

    Directory of Open Access Journals (Sweden)

    Juan Felipe Diaz Quiroz

    2014-06-01

    Full Text Available Most spinal cord injuries lead to permanent paralysis in mammals. By contrast, the remarkable regenerative abilities of salamanders enable full functional recovery even from complete spinal cord transections. The molecular differences underlying this evolutionary divergence between mammals and amphibians are poorly understood. We focused on upstream regulators of gene expression as primary entry points into this question. We identified a group of microRNAs (miRNAs that are conserved between the Mexican axolotl salamander (Ambystoma mexicanum and mammals but show marked cross-species differences in regulation patterns following spinal cord injury. We found that precise post-injury levels of one of these miRNAs (miR-125b is essential for functional recovery, and guides correct regeneration of axons through the lesion site in a process involving the direct downstream target Sema4D in axolotls. Translating these results to a mammalian model, we increased miR-125b levels in the rat through mimic treatments following spinal cord transection. These treatments downregulated Sema4D and other glial-scar-related genes, and enhanced the animal’s functional recovery. Our study identifies a key regulatory molecule conserved between salamander and mammal, and shows that the expression of miR-125b and Sema4D must be carefully controlled in the right cells at the correct level to promote regeneration. We also show that these molecular components of the salamander’s regeneration-permissive environment can be experimentally harnessed to improve treatment outcomes for mammalian spinal cord injuries.

  12. Biomaterial Selection for Tooth Regeneration

    OpenAIRE

    2011-01-01

    Biomaterials are native or synthetic polymers that act as carriers for drug delivery or scaffolds for tissue regeneration. When implanted in vivo, biomaterials should be nontoxic and exert intended functions. For tooth regeneration, biomaterials have primarily served as a scaffold for (1) transplanted stem cells and/or (2) recruitment of endogenous stem cells. This article critically synthesizes our knowledge of biomaterial use in tooth regeneration, including the selection of native and/or s...

  13. Hepatocyte growth factor in renal failure: promise and reality.

    Science.gov (United States)

    Vargas, G A; Hoeflich, A; Jehle, P M

    2000-04-01

    Can science discover some secrets of Greek mythology? In the case of Prometheus, we can now suppose that his amazing hepatic regeneration was caused by a peptide growth factor called hepatocyte growth factor (HGF). Increasing evidence indicates that HGF acts as a multifunctional cytokine on different cell types. This review addresses the molecular mechanisms that are responsible for the pleiotropic effects of HGF. HGF binds with high affinity to its specific tyrosine kinase receptor c-met, thereby stimulating not only cell proliferation and differentiation, but also cell migration and tumorigenesis. The three fundamental principles of medicine-prevention, diagnosis, and therapy-may be benefited by the rational use of HGF. In renal tubular cells, HGF induces mitogenic and morphogenetic responses. In animal models of toxic or ischemic acute renal failure, HGF acts in a renotropic and nephroprotective manner. HGF expression is rapidly up-regulated in the remnant kidney of nephrectomized rats, inducing compensatory growth. In a mouse model of chronic renal disease, HGF inhibits the progression of tubulointerstitial fibrosis and kidney dysfunction. Increased HGF mRNA transcripts were detected in mesenchymal and tubular epithelial cells of rejecting kidney. In transplanted patients, elevated HGF levels may indicate renal rejection. When HGF is considered as a therapeutic agent in human medicine, for example, to stimulate kidney regeneration after acute injury, strategies need to be developed to stimulate cell regeneration and differentiation without an induction of tumorigenesis.

  14. Primary renal primitive neuroectodermal tumor.

    Science.gov (United States)

    Goel, V; Talwar, V; Dodagoudar, C; Singh, S; Sharma, A; Patnaik, N

    2015-01-01

    Primitive Neuroectodermal Tumor of the kidney is a rare entity. Very few cases of primary renal PNET have been reported to date. Most literature about rPNET is isolated case reports. We report a case of rPNET in a 39-year-old male with a pre-operative diagnosis of renal cell carcinoma with renal vein thrombosis. The patient underwent radical nephrectomy with thrombolectomy, and histopathological examination revealed a highly aggressive tumor composed of monotonous sheets of round cells. Tumor cells were positive for CD 99 and FLI-1, hence confirming the diagnosis of Primitive Neuroectodermal Tumor. Post-surgery, patient was given VAC/IE-based adjuvant chemotherapy. In view of highly aggressive nature of this tumor, prompt diagnosis and imparting effective chemotherapy regimen to the patient is required, and it is important to differentiate PNET from other small round-cell tumors because of different therapeutic approach.

  15. Pseudoporphyria secondary to renal failure

    Directory of Open Access Journals (Sweden)

    Lilianna Kulczycka-Siennicka

    2017-04-01

    Full Text Available Introduction . Pseudoporphyria is a rare disease associated with chronic renal failure. Symptoms of pseudoporphyria may develop in response to UV exposure and medications. The literature reports cases of pseudoporphyria in patients infected with hepatis C virus, HIV and undergoing dialysis therapy. Objective . Presentation of the case of a patient with pseudoporphyria and uraemic pruritus, and overview of therapeutic management. Case report . A 64-year-old male patient, who had been on dialysis for chronic renal failure secondary to type 2 diabetes for the past 11 years, presented with tense bullae located on sun-exposed skin which had persisted for the previous 5 months. The patient was diagnosed with pseudoporphyria, and treatment was prescribed including N-acetylcysteine, chloroquine, paroxetine and mianserin. An improvement in the patient’s clinical condition and a regression of pruritus were achieved. Conclusions . Patients with renal failure may develop symptoms of pseudoporphyria requiring differentiation from porphyria cutanea tarda.

  16. [Acetaminophen (paracetamol) causing renal failure: report on 3 pediatric cases].

    Science.gov (United States)

    Le Vaillant, J; Pellerin, L; Brouard, J; Eckart, P

    2013-06-01

    Renal failure secondary to acetaminophen poisoning is rare and occurs in approximately 1-2 % of patients with acetaminophen overdose. The pathophysiology is still being debated, and renal acetaminophen toxicity consists of acute tubular necrosis, without complication if treated promptly. Renal involvement can sometimes occur without prior liver disease, and early renal manifestations usually occur between the 2nd and 7th day after the acute acetaminophen poisoning. While therapy is exclusively symptomatic, sometimes serious metabolic complications can be observed. The monitoring of renal function should therefore be considered as an integral part of the management of children with acute, severe acetaminophen intoxication. We report 3 cases of adolescents who presented with acute renal failure as a result of voluntary drug intoxication with acetaminophen. One of these 3 girls developed severe renal injury without elevated hepatic transaminases. None of the 3 girls' renal function required hemodialysis, but one of the 3 patients had metabolic complications after her acetaminophen poisoning.

  17. Investigation of all-optical regeneration based on self-phase modulation in microstructured fibers

    Institute of Scientific and Technical Information of China (English)

    WEI Yan-fen; XU Yong-zhao; Zhang Xia; HUANG Yong-qing; REN Xiao-min

    2007-01-01

    All-optical regeneration based on self-phase modulation in microstructured fibers is studied. The effects of pulse peak power into the fiber,pulse width and filter parameters on the performance of the regenerator are investigated. The effects of normal dispersion and anomalous dispersion of the microstructured fiber on optical regeneration are compared. The numerical results show that optical regeneration can be achieved by using microstructured fibers with normal dispersion or anomalous dispersion,but the normal dispersion decreases the oscillatory structure in the broadened spectra and obtain a better regenerator transfer function. In order to achieve optical regeneration,the input peak power into the microstructured fiber and the filter parameters need to meet certain requirements. By optimizing those parameters,a better regeneration result can be obtained.

  18. HYPERTENSION IN RENAL ALLOGRAFT RECIPIENTS

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Objective To further evaluate the effect of hypertension on renal graft function, and the relationship between hypertension, hyperlipoidemia and ischemic heart disease. Methods 102 renal transplant recipients with a functioning renal graft for more than 1 year were enrolled in this study. Renal function was followed for the further 24 months. Results The overall prevalence of hypertension was 89.2%(91/102) and 36.2%(33/91) hypertensive patients had uncontrolled blood pressure. After 24 months those with high blood pressure had significantly higher Scr levels than normotensive patients (P<0.05). The number of different antihypertensive classes required was related to Scr (P<0.05). Plasma cholesterol levels in hypertension patients especially in blood pressure uncontrolled group were significantly elevated (P<0.01). Ischemic heart disease was more common in hypertensive patients (P<0.05). Cyclosporine A was associated with hypertension more frequently than azathioprine and FK506, whereas low-dose prednisolone did not appear to influence blood pressure. Conclusion The data further confirmed that hypertension was associated with hyperlipidemia and ischemic heart disease, and emerged as a predictor of renal graft dysfunction. Whether cyclosporine A should be converted to new immunosuppressive agents and which class of antihypertensive medication is more effective in this population remain open questions.

  19. Gastrointestinal complications in renal transplantation

    Directory of Open Access Journals (Sweden)

    Kamal Jeet Singh

    2004-01-01

    Full Text Available Objective: Gastrointestinal complications are responsible for substantial morbidity and mortality among renal allograft recipients. We retrospectively analyzed incidence of these complications and their impact on the patient outcome. Materials & Methods: Between 1998 to Aug 2002, 558 live related renal transplants were performed at our center. The immunosuppression used consisted mainly of cyclosporine, azathioprine and prednisolone, though varied in some patients. These patients were followed for any occurrence of significant gastrointestinal problems. Results: Out of the of 538 renal transplant recipients studied, gastro esophageal ulcerations were seen in 3% patients. Acute pancreatitis was observed in twelve (2.2% patients and four patients had acute intestinal obstruction secondary to fecal impaction. Infectious complications included acute diarrheas in 18% of patients. Three patients developed abdominal tuberculosis. Acute rejection episodes were encountered in 26% of the patients. During these episodes, 58% of patients experienced prolonged ileus. Most of these complications (66% occurred within first one-year post transplant. Three patients presenting with acute intestinal obstruction required laparotomy (two- bands, one-intussusception. There were four mortalities -two patients had severe pancreatitis, one patient had massive upper GI bleed and one succumbed due to perforation peritonitis. Conclusions: Gastrointestinal complications account for significant morbidity and mortality in renal transplant recipients. Paralytic ileus secondary to acute vascular rejection is quite common and resolves spontaneously with recovery of renal function.

  20. Understanding Urban Regeneration in Turkey

    Science.gov (United States)

    Candas, E.; Flacke, J.; Yomralioglu, T.

    2016-06-01

    In Turkey, rapid population growth, informal settlements, and buildings and infrastructures vulnerable to natural hazards are seen as the most important problems of cities. Particularly disaster risk cannot be disregarded, as large parts of various cities are facing risks from earthquakes, floods and landslides and have experienced loss of lives in the recent past. Urban regeneration is an important planning tool implemented by local and central governments in order to reduce to disaster risk and to design livable environments for the citizens. The Law on the Regeneration of Areas under Disaster Risk, commonly known as the Urban Regeneration Law, was enacted in 2012 (Law No.6306, May 2012). The regulation on Implementation of Law No. 6306 explains the fundamental steps of the urban regeneration process. The relevant institutions furnished with various authorities such as expropriation, confiscation and changing the type and place of your property which makes urban regeneration projects very important in terms of property rights. Therefore, urban regeneration projects have to be transparent, comprehensible and acceptable for all actors in the projects. In order to understand the urban regeneration process, the legislation and projects of different municipalities in Istanbul have been analyzed. While some steps of it are spatial data demanding, others relate to land values. In this paper an overview of the urban regeneration history and activities in Turkey is given. Fundamental steps of the urban regeneration process are defined, and particularly spatial-data demanding steps are identified.

  1. Synthetic Phage for Tissue Regeneration

    Directory of Open Access Journals (Sweden)

    So Young Yoo

    2014-01-01

    Full Text Available Controlling structural organization and signaling motif display is of great importance to design the functional tissue regenerating materials. Synthetic phage, genetically engineered M13 bacteriophage has been recently introduced as novel tissue regeneration materials to display a high density of cell-signaling peptides on their major coat proteins for tissue regeneration purposes. Structural advantages of their long-rod shape and monodispersity can be taken together to construct nanofibrous scaffolds which support cell proliferation and differentiation as well as direct orientation of their growth in two or three dimensions. This review demonstrated how functional synthetic phage is designed and subsequently utilized for tissue regeneration that offers potential cell therapy.

  2. Regenerable solid imine sorbents

    Science.gov (United States)

    Gray, McMahan; Champagne, Kenneth J.; Fauth, Daniel; Beckman, Eric

    2013-09-10

    Two new classes of amine-based sorbents are disclosed. The first class comprises new polymer-immobilized tertiary amine sorbents; the second class new polymer-bound amine sorbents. Both classes are tailored to facilitate removal of acid anhydrides, especially carbon dioxide (CO.sub.2), from effluent gases. The amines adsorb acid anhydrides in a 1:1 molar ratio. Both classes of amine sorbents adsorb in the temperature range from about 20.degree. C. upwards to 90.degree. C. and can be regenerated by heating upwards to 100.degree. C.

  3. Evaluation of left renal vein entrapment using multidetector computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Poyraz, Ahmet K.; Onur, Mehmet R. [Dept. of Radiology, Firat Univ. School of Medicine, Elazig (Turkey)], e-mail: akursadpoyraz@yahoo.com.tr; Firdolas, Fatih [Dept. of Urology, Firat Univ. School of Medicine, Elazig (Turkey); Kocakoc, Ercan [Dept. of Radiology, Bezmialem Vakif Univ., School of Medicine, Istanbul (Turkey)

    2013-03-15

    Background: Nutcracker syndrome, also called left renal vein entrapment syndrome, is a cause of non-glomerular hematuria with difficulties in diagnosis. Multidetector computed tomography (MDCT) is a powerful tool to prevent unnecessary diagnostic procedures. Purpose: To retrospectively determine the prevalence of nutcracker phenomenon and nutcracker syndrome seen in MDCT in consecutive patients. Material and Methods: The institutional review board approved the study and waived the requirement for informed consent. Abdominal contrast-enhanced MDCT scans were reviewed from 1000 consecutive patients. MDCT scan assessment included renal vein diameter measurements and evaluation for the presence of anterior or posterior left renal vein entrapment. Electronic medical records and urine analysis reports of patients with left renal vein entrapment were reviewed. Student's t test was used to assess differences in renal vein diameter in patients with left renal vein entrapment. Results: Left renal vein entrapment was observed in 10.9% (109), retroaortic left renal vein in 6.5% (65), entrapment of left renal vein between superior mesenteric artery and aorta in 4.1% (41), and circumaortic left renal vein in 0.3% (3) of patients. Mean diameters of right (8.8 {+-} 1.9 mm) and unentrapped left (8.9 {+-} 1.8 mm) renal veins were not significantly different (P = 0.1). The mean diameter of anterior entrapped left renal veins (10.3 {+-} 2 mm) was significantly greater (P = 0.04) than contralateral renal veins (8.6 {+-} 2.1 mm) in their widest portion. In 8.8% of patients with the left renal vein entrapment, urine analysis showed isomorphic hematuria or proteinuria with no other known cause. Varicocele and pelvic congestion were seen in 5.5% of patients with the left renal vein entrapment. Conclusion: Left renal vein entrapment is not a rare entity and renal nutcracker phenomenon might be underdiagnosed.

  4. Contemporary evaluation and management of renal trauma.

    Science.gov (United States)

    Chouhan, Jyoti D; Winer, Andrew G; Johnson, Christina; Weiss, Jeffrey P; Hyacinthe, Llewellyn M

    2016-04-01

    Renal trauma occurs in approximately 1%-5% of all trauma cases. Improvements in imaging and management over the last two decades have caused a shift in the treatment of this clinical condition. A systematic search of PubMed was performed to identify relevant and contemporary articles that referred to the management and evaluation of renal trauma. Computed tomography remains a mainstay of radiological evaluation in hemodynamically stable patients. There is a growing body of literature showing that conservative, non-operative management of renal trauma is safe, even for Grade IV-V renal injuries. If surgical exploration is planned due to other injuries, a conservative approach to the kidney can often be utilized. Follow up imaging may be warranted in certain circumstances. Urinoma, delayed bleeding, and hypertension are complications that require follow up. Appropriate imaging and conservative approaches are a mainstay of current renal trauma management.

  5. Minimization of the Flowrate of Fresh Water and Corresponding Regenerated Water in Water-using System with Regeneration Reuse

    Institute of Scientific and Technical Information of China (English)

    徐冬梅; 胡仰栋; 华贲; 王修林

    2003-01-01

    A sequential three-step programming method is proposed for determining the minimum flowrate of fresh water and corresponding regenerated water in water-using system of single contaminant with regeneration reuse.In step 1, a programming with the objective of min fws is used to determine the minimum flowrate of fresh water,in which the mathematical representation is a mixed integer nonlinear programming (MINLP1). Then under the same constraints with step 1, a programming with the objective of min freg in step 2 and a programming with the objective of rain Cr in step 3 are subsequently used to determine the minimum flowrate of regenerated water and the minimum inlet concentration to regeneration process corresponding to the minimum flowrate of fresh water based on step 1. The method is easy to apply because we only need to change the objective function but keep the constraints constant to go along the following steps after step 1. In addition, the relationship between the fresh water flowrate required, fws, and inlet concentration to regeneration process, Cr, is investigated. It is found that there exist three relationships between fws and Cr, which indicate three possibilities for Cb: below the pinch, above the pinch or at the pinch. Therefore, a new conclusion is drawn, which differs from that "regeneration of water at pinch minimizes fresh water flowrate" derived in literature and indicates that in some cases, regeneration at other point also minimizes fresh water flowrate.

  6. Functional joint regeneration is achieved using reintegration mechanism in Xenopus laevis.

    Science.gov (United States)

    Tsutsumi, Rio; Yamada, Shigehito; Agata, Kiyokazu

    2016-02-01

    A functional joint requires integration of multiple tissues: the apposing skeletal elements should form an interlocking structure, and muscles should insert into skeletal tissues via tendons across the joint. Whereas newts can regenerate functional joints after amputation, Xenopus laevis regenerates a cartilaginous rod without joints, a "spike." Previously we reported that the reintegration mechanism between the remaining and regenerated tissues has a significant effect on regenerating joint morphogenesis during elbow joint regeneration in newt. Based on this insight into the importance of reintegration, we amputated frogs' limbs at the elbow joint and found that frogs could regenerate a functional elbow joint between the remaining tissues and regenerated spike. During regeneration, the regenerating cartilage was partially connected to the remaining articular cartilage to reform the interlocking structure of the elbow joint at the proximal end of the spike. Furthermore, the muscles of the remaining part inserted into the regenerated spike cartilage via tendons. This study might open up an avenue for analyzing molecular and cellular mechanisms of joint regeneration using Xenopus.

  7. Transcriptional components of anteroposterior positional information during zebrafish fin regeneration.

    Science.gov (United States)

    Nachtrab, Gregory; Kikuchi, Kazu; Tornini, Valerie A; Poss, Kenneth D

    2013-09-01

    Many fish and salamander species regenerate amputated fins or limbs, restoring the size and shape of the original appendage. Regeneration requires that spared cells retain or recall information encoding pattern, a phenomenon termed positional memory. Few factors have been implicated in positional memory during vertebrate appendage regeneration. Here, we investigated potential regulators of anteroposterior (AP) pattern during fin regeneration in adult zebrafish. Sequence-based profiling from tissues along the AP axis of uninjured pectoral fins identified many genes with region-specific expression, several of which encoded transcription factors with known AP-specific expression or function in developing embryonic pectoral appendages. Transgenic reporter strains revealed that regulatory sequences of the transcription factor gene alx4a activated expression in fibroblasts and osteoblasts within anterior fin rays, whereas hand2 regulatory sequences activated expression in these same cell types within posterior rays. Transgenic overexpression of hand2 in all pectoral fin rays did not affect formation of the proliferative regeneration blastema, yet modified the lengths and widths of regenerating bones. Hand2 influenced the character of regenerated rays in part by elevation of the vitamin D-inactivating enzyme encoded by cyp24a1, contributing to region-specific regulation of bone metabolism. Systemic administration of vitamin D during regeneration partially rescued bone defects resulting from hand2 overexpression. Thus, bone-forming cells in a regenerating appendage maintain expression throughout life of transcription factor genes that can influence AP pattern, and differ across the AP axis in their expression signatures of these and other genes. These findings have implications for mechanisms of positional memory in vertebrate tissues.

  8. Diamex solvent regeneration studies

    Energy Technology Data Exchange (ETDEWEB)

    Nicol, C.; Cames, B.; Margot, L.; Ramain, L. [CEA/VALRHO - site de Marcoule, Dept. de Recherche en Retraitement et en Vitrification, DRRV, 30 - Marcoule (France)

    2000-07-01

    The CEA has undertaken the development of the DIAMEX process as the first step in the strategy aiming at recovering minor actinides which could then be transmuted or separately conditioned. The scientific feasibility of this process was demonstrated during counter current hot tests operated in 1993. Then experimental works were conducted, on one hand to optimise the extractant formula, on the other hand to improve the flowsheet. Reference extractant and flowsheet were then chosen, respectively in 1995 and 1996. The next step, still in progress, is the demonstration of the DIAMEX technical feasibility (in 2002); this means that the flowsheet should include solvent regeneration treatments. In this aim, degradation studies were performed to quantify main degradation products, and identify those which could be disturbing in the process. This paper deals with experimental studies performed with intend to propose a regeneration treatment, included in the flowsheet, so that the solvent could be recycled. It comprises: - Quantification of the main degradation products issued from radiolysis or hydrolysis, which are methyl octyl amine (MOA) and carboxylic acids; - Effects of these products on extracting and hydrodynamics performances of the process; - Study of methods able to remove mainly disturbing degradation products. Acidic scrubbing, which are performed in the scrubbing and stripping sections of the DIAMEX process, should allow the quantitative removal of methyl octyl amine. Then basic scrubbings, which were more especially studied, should eliminate at least 80% of carboxylic acids, and part of the cations remaining in the solvent. (authors)

  9. Nerve dependence in tissue, organ, and appendage regeneration.

    Science.gov (United States)

    Kumar, Anoop; Brockes, Jeremy P

    2012-11-01

    Many regeneration contexts require the presence of regenerating nerves as a transient component of the progenitor cell niche. Here we review nerve involvement in regeneration of various structures in vertebrates and invertebrates. Nerves are also implicated as persistent determinants in the niche of certain stem cells in mammals, as well as in Drosophila. We consider our present understanding of the cellular and molecular mechanisms underlying nerve dependence, including evidence of critical interactions with glia and non-neural cell types. The example of the salamander aneurogenic limb illustrates that developmental interactions between the limb bud and its innervation can be determinative for adult regeneration. These phenomena provide a different perspective on nerve cells to that based on chemical and electrical excitability.

  10. Repairing Multiple Failures with Coordinated and Adaptive Regenerating Codes

    CERN Document Server

    Kermarrec, Anne-Marie; Scouarnec, Nicolas Le

    2011-01-01

    Erasure correcting codes are widely used to ensure data persistence in distributed storage systems. This paper addresses the repair of such codes in the presence of simultaneous failures. It is crucial to maintain the required redundancy over time to prevent permanent data losses. We go beyond existing work (i.e., regenerating codes by Dimakis et al.) and propose coordinated regenerating codes allowing devices to coordinate during simultaneous repairs thus reducing the costs further. We provide closed form expressions of the communication costs of our new codes depending on the number of live devices and the number of devices being repaired. We prove that deliberately delaying repairs does not bring additional gains in itself. This means that regenerating codes are optimal as long as each failure can be repaired before a second one occurs. Yet, when multiple failures are detected simultaneously, we prove that our coordinated regenerating codes are optimal and outperform uncoordinated repairs (with respect to ...

  11. In situ tissue regeneration: chemoattractants for endogenous stem cell recruitment.

    Science.gov (United States)

    Vanden Berg-Foels, Wendy S

    2014-02-01

    Tissue engineering uses cells, signaling molecules, and/or biomaterials to regenerate injured or diseased tissues. Ex vivo expanded mesenchymal stem cells (MSC) have long been a cornerstone of regeneration therapies; however, drawbacks that include altered signaling responses and reduced homing capacity have prompted investigation of regeneration based on endogenous MSC recruitment. Recent successful proof-of-concept studies have further motivated endogenous MSC recruitment-based approaches. Stem cell migration is required for morphogenesis and organogenesis during development and for tissue maintenance and injury repair in adults. A biomimetic approach to in situ tissue regeneration by endogenous MSC requires the orchestration of three main stages: MSC recruitment, MSC differentiation, and neotissue maturation. The first stage must result in recruitment of a sufficient number of MSC, capable of effecting regeneration, to the injured or diseased tissue. One of the challenges for engineering endogenous MSC recruitment is the selection of effective chemoattractant(s). The objective of this review is to synthesize and evaluate evidence of recruitment efficacy by reported chemoattractants, including growth factors, chemokines, and other more recently appreciated MSC chemoattractants. The influence of MSC tissue sources, cell culture methods, and the in vitro and in vivo environments is discussed. This growing body of knowledge will serve as a basis for the rational design of regenerative therapies based on endogenous MSC recruitment. Successful endogenous MSC recruitment is the first step of successful tissue regeneration.

  12. Progesterone and peripheral nerve regeneration

    Institute of Scientific and Technical Information of China (English)

    Fei Fan; Haichao Li; Yuwei Wang; Yanglin Zheng; Lianjun Jia; Zhihui Wang

    2006-01-01

    OBJECTIVE: To explore the effect of progesterone on peripheral nerve regeneration.DATA SOURCES: An online search of Medline and OVID databases was under taken to identify articles about progesterone and peripheral nerve regeneration published in English between January 1990 and June 2004 by using the keywords of "peripheral nerve, injury, progesterone, regeneration".STUDY SELECTION: The data were primarily screened, those correlated with progesterone and peripheral nerve regeneration were involved, and their original articles were further searched, the repetitive studies or reviews were excluded.DATA EXTRACTION: Totally 59 articles about progesterone and peripheral nerve regeneration were collected, and 26 of them were involved, the other 33 excluded ones were the repetitive studies or reviews.DATA SYNTHESIS: Recent researches found that certain amount of progesterone could be synthetized in peripheral nervous system, and the expression of progesterone receptor could be found in sensory neurons and Schwann cells. After combined with the receptor, endogenous and exogenous progesterone can accelerate the formation of peripheral nerve myelin sheath, also promote the axonal regeneration.CONCLUSION: Progesterone plays a role in protecting neurons, increasing the sensitivity of nerve tissue to nerve growth factor, and accelerating regeneration of nerve in peripheral nerve regeneration, which provides theoretical references for the treatment of demyelinated disease and nerve injury, as well as the prevention of neuroma, especially that the in vivo level of progesterone should be considered for the elderly people accompanied by neuropathy and patients with congenital luteal phase defect, which is of positive significance in guiding the treatment.

  13. Molecular approach to echinoderm regeneration.

    Science.gov (United States)

    Thorndyke, M C; Chen, W C; Beesley, P W; Patruno, M

    2001-12-15

    Until very recently echinoderm regeneration research and indeed echinoderm research in general has suffered because of the lack of critical mass. In terms of molecular studies of regeneration, echinoderms in particular have lagged behind other groups in this respect. This is in sharp contrast to the major advances achieved with molecular and genetic techniques in the study of embryonic development in echinoderms. The aim of our studies has been to identify genes involved in the process of regeneration and in particular neural regeneration in different echinoderm species. Our survey included the asteroid Asterias rubens and provided evidence for the expression of Hox gene homologues in regenerating radial nerve cords. Present evidence suggests: 1) ArHox1 expression is maintained in intact radial nerve cord and may be upregulated during regeneration. 2) ArHox1 expression may contribute to the dedifferentiation and/or cell proliferation process during epimorphic regeneration. From the crinoid Antedon bifida, we have been successful in cloning a fragment of a BMP2/4 homologue (AnBMP2/4) and analysing its expression during arm regeneration. Here, we discuss the importance of this family of growth factors in several regulatory spheres, including maintaining the identity of pluripotent blastemal cells or as a classic skeletal morphogenic regulator. There is clearly substantial scope for future echinoderm research in the area of molecular biology and certain aspects are discussed in this review.

  14. Tissue absence initiates regeneration through follistatin-mediated inhibition of activin signaling.

    Science.gov (United States)

    Gaviño, Michael A; Wenemoser, Danielle; Wang, Irving E; Reddien, Peter W

    2013-09-10

    Regeneration is widespread, but mechanisms that activate regeneration remain mysterious. Planarians are capable of whole-body regeneration and mount distinct molecular responses to wounds that result in tissue absence and those that do not. A major question is how these distinct responses are activated. We describe a follistatin homolog (Smed-follistatin) required for planarian regeneration. Smed-follistatin inhibition blocks responses to tissue absence but does not prevent normal tissue turnover. Two activin homologs (Smed-activin-1 and Smed-activin-2) are required for the Smed-follistatin phenotype. Finally, Smed-follistatin is wound-induced and expressed at higher levels following injuries that cause tissue absence. These data suggest that Smed-follistatin inhibits Smed-Activin proteins to trigger regeneration specifically following injuries involving tissue absence and identify a mechanism critical for regeneration initiation, a process important across the animal kingdom. DOI:http://dx.doi.org/10.7554/eLife.00247.001.

  15. Kidney (Renal) Failure

    Science.gov (United States)

    ... How is kidney failure treated? What is kidney (renal) failure? The kidneys are designed to maintain proper fluid ... marrow and strengthen the bones. The term kidney (renal) failure describes a situation in which the kidneys have ...

  16. Renal arteries (image)

    Science.gov (United States)

    A renal angiogram is a test used to examine the blood vessels of the kidneys. The test is performed ... main vessel of the pelvis, up to the renal artery that leads into the kidney. Contrast medium ...

  17. A small molecule screen identifies in vivo modulators of peripheral nerve regeneration in zebrafish

    Science.gov (United States)

    Skinner, Julianne; Granato, Michael

    2017-01-01

    Adult vertebrates have retained the ability to regenerate peripheral nerves after injury, although regeneration is frequently incomplete, often leading to functional impairments. Small molecule screens using whole organisms have high potential to identify biologically relevant targets, yet currently available assays for in vivo peripheral nerve regeneration are either very laborious and/or require complex technology. Here we take advantage of the optical transparency of larval zebrafish to develop a simple and fast pectoral fin removal assay that measures peripheral nerve regeneration in vivo. Twenty-four hours after fin amputation we observe robust and stereotyped nerve regrowth at the fin base. Similar to laser mediated nerve transection, nerve regrowth after fin amputation requires Schwann cells and FGF signaling, confirming that the fin amputation assay identifies pathways relevant for peripheral nerve regeneration. From a library of small molecules with known targets, we identified 21 compounds that impair peripheral nerve regeneration. Several of these compounds target known regulators of nerve regeneration, further validating the fin removal assay. Twelve of the identified compounds affect targets not previously known to control peripheral nerve regeneration. Using a laser-mediated nerve transection assay we tested ten of those compounds and confirmed six of these compounds to impair peripheral nerve regeneration: an EGFR inhibitor, a glucocorticoid, prostaglandin D2, a retinoic acid agonist, an inhibitor of calcium channels and a topoisomerase I inhibitor. Thus, we established a technically simple assay to rapidly identify valuable entry points into pathways critical for vertebrate peripheral nerve regeneration. PMID:28575069

  18. The Basis of Muscle Regeneration

    Directory of Open Access Journals (Sweden)

    Antonio Musarò

    2014-01-01

    Full Text Available Muscle regeneration recapitulates many aspects of embryonic myogenesis and is an important homeostatic process of the adult skeletal muscle, which, after development, retains the capacity to regenerate in response to appropriate stimuli, activating the muscle compartment of stem cells, namely, satellite cells, as well as other precursor cells. Moreover, significant evidence suggests that while stem cells represent an important determinant for tissue regeneration, a “qualified” environment is necessary to guarantee and achieve functional results. It is therefore plausible that the loss of control over these cell fate decisions could lead to a pathological transdifferentiation, leading to pathologic defects in the regenerative process. This review provides an overview about the general aspects of muscle development and discusses the cellular and molecular aspects that characterize the five interrelated and time-dependent phases of muscle regeneration, namely, degeneration, inflammation, regeneration, remodeling, and maturation/functional repair.

  19. A bioartificial renal tubule device embedding human renal stem/progenitor cells.

    Directory of Open Access Journals (Sweden)

    Anna Giovanna Sciancalepore

    Full Text Available We present a bio-inspired renal microdevice that resembles the in vivo structure of a kidney proximal tubule. For the first time, a population of tubular adult renal stem/progenitor cells (ARPCs was embedded into a microsystem to create a bioengineered renal tubule. These cells have both multipotent differentiation abilities and an extraordinary capacity for injured renal cell regeneration. Therefore, ARPCs may be considered a promising tool for promoting regenerative processes in the kidney to treat acute and chronic renal injury. Here ARPCs were grown to confluence and exposed to a laminar fluid shear stress into the chip, in order to induce a functional cell polarization. Exposing ARPCs to fluid shear stress in the chip led the aquaporin-2 transporter to localize at their apical region and the Na(+K(+ATPase pump at their basolateral portion, in contrast to statically cultured ARPCs. A recovery of urea and creatinine of (20±5% and (13±5%, respectively, was obtained by the device. The microengineered biochip here-proposed might be an innovative "lab-on-a-chip" platform to investigate in vitro ARPCs behaviour or to test drugs for therapeutic and toxicological responses.

  20. [The relevance of a decline in renal function for risk of renal failure, cardiovascular events and all-cause mortality].

    Science.gov (United States)

    Bots, Michiel L; Blankestijn, Peter J

    2015-01-01

    It is well established that the presence of impaired renal function is associated with an increased risk of end-stage renal disease, cardiovascular events and all-cause mortality. Irrespective of the starting level of renal function, a decline in renal function over two years is a relevant and strong risk factor for end-stage renal disease, cardiovascular death and all-cause mortality. Even a decline of 20 to 30 per cent is associated with to a considerable increased risk and requires further attention.

  1. Insights into kidney stem cell development and regeneration using zebrafish

    Institute of Scientific and Technical Information of China (English)

    Bridgette; E; Drummond; Rebecca; A; Wingert

    2016-01-01

    Kidney disease is an escalating global health problem,for which the formulation of therapeutic approaches using stem cells has received increasing research attention.The complexity of kidney anatomy and function,which includes the diversity of renal cell types,poses formidable challenges in the identification of methods to generate replacement structures.Recent work using the zebrafish has revealed their high capacity to regenerate the integral working units of the kidney,known as nephrons,following acute injury.Here,we discuss these findings and explore the ways that zebrafish can be further utilized to gain a deeper molecular appreciation of renal stem cell biology,which may uncover important clues for regenerative medicine.

  2. [Renal leiomyoma. Case report].

    Science.gov (United States)

    Joual, A; Guessous, H; Rabii, R; Benjelloun, M; Benlemlih, A; Skali, K; el Mrini, M; Benjelloun, S

    1999-01-01

    The authors report a case of renal leiomyoma observed in a 56-year-old man. This cyst presented in the from of loin pain. Computed tomography revealed a homogeneous renal tumor. Treatment consisted of radical nephrectomy. Histological examination of the specimen showed benign renal leiomyoma.

  3. Renal inflammatory myofibroblastic tumor

    DEFF Research Database (Denmark)

    Heerwagen, S T; Jensen, C; Bagi, P

    2007-01-01

    Renal inflammatory myofibroblastic tumor (IMT) is a rare soft-tissue tumor of controversial etiology with a potential for local recurrence after incomplete surgical resection. The radiological findings in renal IMT are not well described. We report two cases in adults with a renal mass treated...

  4. Timber tree regeneration along abandoned logging roads in a tropical Bolivian forest

    DEFF Research Database (Denmark)

    Nabe-Nielsen, J.; Severiche, W.; Fredericksen, T.;

    2007-01-01

    Sustainable management of selectively logged tropical forests requires that felled trees are replaced through increased recruitment and growth. This study compares road track and roadside regeneration with regeneration in unlogged and selectively logged humid tropical forest in north...... areas should be ensured by interspersing large patches of unlogged forest with logged areas. This may also assist regeneration of species that perform poorly in disturbed areas....

  5. A regulatory program for excretory system regeneration in planarians.

    Science.gov (United States)

    Scimone, M Lucila; Srivastava, Mansi; Bell, George W; Reddien, Peter W

    2011-10-01

    Planarians can regenerate any missing body part, requiring mechanisms for the production of organ systems in the adult, including their prominent tubule-based filtration excretory system called protonephridia. Here, we identify a set of genes, Six1/2-2, POU2/3, hunchback, Eya and Sall, that encode transcription regulatory proteins that are required for planarian protonephridia regeneration. During regeneration, planarian stem cells are induced to form a cell population in regeneration blastemas expressing Six1/2-2, POU2/3, Eya, Sall and Osr that is required for excretory system formation. POU2/3 and Six1/2-2 are essential for these precursor cells to form. Eya, Six1/2-2, Sall, Osr and POU2/3-related genes are required for vertebrate kidney development. We determined that planarian and vertebrate excretory cells express homologous proteins involved in reabsorption and waste modification. Furthermore, we identified novel nephridia genes. Our results identify a transcriptional program and cellular mechanisms for the regeneration of an excretory organ and suggest that metazoan excretory systems are regulated by genetic programs that share a common evolutionary origin.

  6. Photon Regeneration Plans

    CERN Document Server

    Ringwald, A

    2006-01-01

    Precision experiments exploiting low-energy photons may yield information on particle physics complementary to experiments at high-energy colliders, in particular on new very light and very weakly interacting particles, predicted in many extensions of the standard model. Such particles may be produced by laser photons send along a transverse magnetic field. The laser polarization experiment PVLAS may have seen the first indirect signal of such particles by observing an anomalously large rotation of the polarization plane of photons after the passage through a magnetic field. This can be interpreted as evidence for photon disappearance due to particle production. There are a number of experimental proposals to test independently the particle interpretation of PVLAS. Many of them are based on the search for photon reappearance or regeneration, i.e. for ``light shining through a wall''. At DESY, the Axion-Like Particle Search (ALPS) collaboration is currently setting up such an experiment.

  7. Photon regeneration plans

    Energy Technology Data Exchange (ETDEWEB)

    Ringwald, A.

    2006-12-15

    Precision experiments exploiting low-energy photons may yield information on particle physics complementary to experiments at high-energy colliders, in particular on new very light and very weakly interacting particles, predicted in many extensions of the standard model. Such particles may be produced by laser photons send along a transverse magnetic field. The laser polarization experiment PVLAS may have seen the first indirect signal of such particles by observing an anomalously large rotation of the polarization plane of photons after the passage through a magnetic field. This can be interpreted as evidence for photon disappearance due to particle production. There are a number of experimental proposals to test independently the particle interpretation of PVLAS. Many of them are based on the search for photon reappearance or regeneration, i.e. for ''light shining through a wall''. At DESY, the Axion-Like Particle Search (ALPS) collaboration is currently setting up such an experiment. (orig.)

  8. A regenerable bitumen composition

    Energy Technology Data Exchange (ETDEWEB)

    Sudzuki, K.; Asakava, Y.; Matsui, A.; Ogava, A.

    1982-10-18

    The regenerable bitumin composition includes the bitumen material (asphalt, oxidized bitumen, petroleum or asphalt pitch) emulsified by an cation emulsifier (alkylamine or an imidazole derivative) and additionally by a noniononic emulsifier (polyoxyethylenamine), an amide, which contains greater than 1 amide groups per molecule (amide derivative, imidazoline), an epoxide compound with greater than 1 epoxide group per molecule (preferably with an epoxy equivalent of 180 to 500), an inorganic compound which hardens in water (Portland cement or silicate cement) and additionally, water. The total content of the second third components is 1 to 200 parts per million to 100 parts of the first component, while the content of the fourth component is from 1 to 400 parts. The water content in the composition is 5 to 1,000 percent of the total content of the first three components. The patented composition is characterized by high stability, strength, chemical stability, resistance to water and good adhesion properties.

  9. [Multiple complications after renal transplantation].

    Science.gov (United States)

    Manrique, J; Rossich, E; Hernández Sierra, A

    2004-01-01

    This is the case of a 32-year-old male patient, diagnosed with end stage renal disease secondary to a focal and segmental glomerulonephritis. After four years of haemodialysis, he received a renal graft from a cadaveric donor. During the following sixteen years, he developped many different complications. In the early post-transplant period, he developed a severe acute tubular necrosis and two episodes of acute rejection took place, both of them with later recovery. Among the outstanding infectious complications were a virus herpes zoster dorsal infection and a Pseudomonas aeruginosa nosocomial pneumonia. Twelve months later, a series of severe digestive complications took place: cholecystitis that required cholecystectomy, pancreatic pseudocyst which required laparotomy because of an abdominal complication, two separate episodes of upper digestive bleeding that finally required gastric surgery, and an hemorrhagic subphrenic abscess that required a second laparotomy. Currently he has developed a calcified chronic pancreatitis. Moreover, metabolic complications must be mentioned carbohydrate intolerance, cataracts and an avascular bone necrosis, all of them closely related to the immunosuppressive therapy. In spite of these multiple complications, he mantains a good renal function and his quality of life is acceptable.

  10. Tissue Regeneration and Stem Cell Distribution in Adriamycin Induced Glomerulopathy

    Science.gov (United States)

    Zickri, Maha Baligh; Fattah, Marwa Mohamed Abdel; Metwally, Hala Gabr

    2012-01-01

    Background and Objectives Glomerulosclerosis develops secondary to various kidney diseases. It was postulated that adriamycin (ADR) induce chronic glomerulopathy. Treatment combinations for one year did not significantly modify renal function in resistant focal segmental glomerulosclerosis (FSGS). Recurrence of FSGS after renal transplantation impacts long-term graft survival and limits access to transplantation. The present study aimed at investigating the relation between the possible therapeutic effect of human mesenchymal stem cells (HMSCs), isolated from cord blood on glomerular damage and their distribution by using ADR induced nephrotoxicity as a model in albino rat. Methods and Results Thirty three male albino rats were divided into control group, ADR group where rats were given single intraperitoneal (IP) injection of 5 mg/kg adriamycin. The rats were sacrificed 10, 20 and 30 days following confirmation of glomerular injury. In stem cell therapy group, rats were injected with HMSCs following confirmation of renal injury and sacrificed 10, 20 and 30 days after HMSCs therapy. Kidney sections were exposed to histological, histochemical, immunohistochemical, morphometric and serological studies. In response to SC therapy multiple Malpighian corpuscles (MC) appeared with patent Bowman's space (Bs) 10 and 20 days following therapy. One month following therapy no remarkable shrunken glomeruli were evident. Glomerular area and serum creatinine were significantly different in ADR group in comparison to control and SC therapy groups. Conclusions ADR induced glomerulosclerosis regressed in response to cord blood HMSC therapy. A reciprocal relation was recorded between the extent of renal regeneration and the distribution of undifferentiated mesenchymal stem cells. PMID:24298364

  11. Postpartum renal vein thrombosis.

    Science.gov (United States)

    Rubens, D; Sterns, R H; Segal, A J

    1985-01-01

    Renal vein thrombosis in adults is usually a complication of the nephrotic syndrome. Rarely, it has been reported in nonnephrotic women postpartum. The thrombosis may be a complication of the hypercoagulable state associated with both the nephrotic syndrome and pregnancy. Two postpartum patients with renal vein thrombosis and no prior history of renal disease are reported here. Neither patient had heavy proteinuria. In both cases, pyelonephritis was suspected clinically and the diagnosis of renal vein thrombosis was first suggested and confirmed by radiologic examination. Renal vein thrombosis should be considered in women presenting postpartum with flank pain.

  12. Renal infarction resulting from traumatic renal artery dissection.

    Science.gov (United States)

    Kang, Kyung Pyo; Lee, Sik; Kim, Won; Jin, Gong Yong; Na, Ki Ryang; Yun, Il Yong; Park, Sung Kwang

    2008-06-01

    Renal artery dissection may be caused by iatrogenic injury, trauma, underlying arterial diseases such as fibromuscular disease, atherosclerotic disease, or connective tissue disease. Radiological imaging may be helpful in detecting renal artery pathology, such as renal artery dissection. For patients with acute, isolated renal artery dissection, surgical treatment, endovascular management, or medical treatment have been considered effective measures to preserve renal function. We report a case of renal infarction that came about as a consequence of renal artery dissection.

  13. A renal registry for Africa: first steps.

    Science.gov (United States)

    Davids, M Razeen; Eastwood, John B; Selwood, Neville H; Arogundade, Fatiu A; Ashuntantang, Gloria; Benghanem Gharbi, Mohammed; Jarraya, Faiçal; MacPhee, Iain A M; McCulloch, Mignon; Plange-Rhule, Jacob; Swanepoel, Charles R; Adu, Dwomoa

    2016-02-01

    There is a dearth of data on end-stage renal disease (ESRD) in Africa. Several national renal registries have been established but have not been sustainable because of resource limitations. The African Association of Nephrology (AFRAN) and the African Paediatric Nephrology Association (AFPNA) recognize the importance of good registry data and plan to establish an African Renal Registry. This article reviews the elements needed for a successful renal registry and gives an overview of renal registries in developed and developing countries, with the emphasis on Africa. It then discusses the proposed African Renal Registry and the first steps towards its implementation. A registry requires a clear purpose, and agreement on inclusion and exclusion criteria, the dataset and the data dictionary. Ethical issues, data ownership and access, the dissemination of findings and funding must all be considered. Well-documented processes should guide data collection and ensure data quality. The ERA-EDTA Registry is the world's oldest renal registry. In Africa, registry data have been published mainly by North African countries, starting with Egypt and Tunisia in 1975. However, in recent years no African country has regularly reported national registry data. A shared renal registry would provide participating countries with a reliable technology platform and a common data dictionary to facilitate joint analyses and comparisons. In March 2015, AFRAN organized a registry workshop for African nephrologists and then took the decision to establish, for the first time, an African Renal Registry. In conclusion, African nephrologists have decided to establish a continental renal registry. This initiative could make a substantial impact on the practice of nephrology and the provision of services for adults and children with ESRD in many African countries.

  14. Cardiac Regeneration and Stem Cells.

    Science.gov (United States)

    Zhang, Yiqiang; Mignone, John; MacLellan, W Robb

    2015-10-01

    After decades of believing the heart loses the ability to regenerate soon after birth, numerous studies are now reporting that the adult heart may indeed be capable of regeneration, although the magnitude of new cardiac myocyte formation varies greatly. While this debate has energized the field of cardiac regeneration and led to a dramatic increase in our understanding of cardiac growth and repair, it has left much confusion in the field as to the prospects of regenerating the heart. Studies applying modern techniques of genetic lineage tracing and carbon-14 dating have begun to establish limits on the amount of endogenous regeneration after cardiac injury, but the underlying cellular mechanisms of this regeneration remained unclear. These same studies have also revealed an astonishing capacity for cardiac repair early in life that is largely lost with adult differentiation and maturation. Regardless, this renewed focus on cardiac regeneration as a therapeutic goal holds great promise as a novel strategy to address the leading cause of death in the developed world.

  15. Biomaterial selection for tooth regeneration.

    Science.gov (United States)

    Yuan, Zhenglin; Nie, Hemin; Wang, Shuang; Lee, Chang Hun; Li, Ang; Fu, Susan Y; Zhou, Hong; Chen, Lili; Mao, Jeremy J

    2011-10-01

    Biomaterials are native or synthetic polymers that act as carriers for drug delivery or scaffolds for tissue regeneration. When implanted in vivo, biomaterials should be nontoxic and exert intended functions. For tooth regeneration, biomaterials have primarily served as a scaffold for (1) transplanted stem cells and/or (2) recruitment of endogenous stem cells. This article critically synthesizes our knowledge of biomaterial use in tooth regeneration, including the selection of native and/or synthetic polymers, three-dimensional scaffold fabrication, stem cell transplantation, and stem cell homing. A tooth is a complex biological organ. Tooth loss represents the most common organ failure. Tooth regeneration encompasses not only regrowth of an entire tooth as an organ, but also biological restoration of individual components of the tooth including enamel, dentin, cementum, or dental pulp. Regeneration of tooth root represents perhaps more near-term opportunities than the regeneration of the whole tooth. In the adult, a tooth owes its biological vitality, arguably more, to the root than the crown. Biomaterials are indispensible for the regeneration of tooth root, tooth crown, dental pulp, or an entire tooth.

  16. Hyperparathyroidism of Renal Disease

    Science.gov (United States)

    Yuen, Noah K; Ananthakrishnan, Shubha; Campbell, Michael J

    2016-01-01

    Renal hyperparathyroidism (rHPT) is a common complication of chronic kidney disease characterized by elevated parathyroid hormone levels secondary to derangements in the homeostasis of calcium, phosphate, and vitamin D. Patients with rHPT experience increased rates of cardiovascular problems and bone disease. The Kidney Disease: Improving Global Outcomes guidelines recommend that screening and management of rHPT be initiated for all patients with chronic kidney disease stage 3 (estimated glomerular filtration rate, < 60 mL/min/1.73 m2). Since the 1990s, improving medical management with vitamin D analogs, phosphate binders, and calcimimetic drugs has expanded the treatment options for patients with rHPT, but some patients still require a parathyroidectomy to mitigate the sequelae of this challenging disease. PMID:27479950

  17. Regenerating articular tissue by converging technologies.

    Directory of Open Access Journals (Sweden)

    Lorenzo Moroni

    Full Text Available Scaffolds for osteochondral tissue engineering should provide mechanical stability, while offering specific signals for chondral and bone regeneration with a completely interconnected porous network for cell migration, attachment, and proliferation. Composites of polymers and ceramics are often considered to satisfy these requirements. As such methods largely rely on interfacial bonding between the ceramic and polymer phase, they may often compromise the use of the interface as an instrument to direct cell fate. Alternatively, here, we have designed hybrid 3D scaffolds using a novel concept based on biomaterial assembly, thereby omitting the drawbacks of interfacial bonding. Rapid prototyped ceramic particles were integrated into the pores of polymeric 3D fiber-deposited (3DF matrices and infused with demineralized bone matrix (DBM to obtain constructs that display the mechanical robustness of ceramics and the flexibility of polymers, mimicking bone tissue properties. Ostechondral scaffolds were then fabricated by directly depositing a 3DF structure optimized for cartilage regeneration adjacent to the bone scaffold. Stem cell seeded scaffolds regenerated both cartilage and bone in vivo.

  18. Sensory hair cell death and regeneration in fishes

    Directory of Open Access Journals (Sweden)

    Jerry D. Monroe

    2015-04-01

    Full Text Available Sensory hair cells are specialized mechanotransductive receptors required for hearing and vestibular function. Loss of hair cells in humans and other mammals is permanent and causes reduced hearing and balance. In the early 1980’s, it was shown that hair cells continue to be added to the inner ear sensory epithelia in cartilaginous and bony fishes. Soon thereafter, hair cell regeneration was documented in the chick cochlea following acoustic trauma. Since then, research using chick and other avian models has led to great insights into hair cell death and regeneration. However, with the rise of the zebrafish as a model organism for studying disease and developmental processes, there has been an increased interest in studying sensory hair cell death and regeneration in its lateral line and inner ears. Advances derived from studies in zebrafish and other fish species include understanding the effect of ototoxins on hair cells and finding otoprotectants to mitigate ototoxin damage, the role of cellular proliferation versus direct transdifferentiation during hair cell regeneration, and elucidating cellular pathways involved in the regeneration process. This review will summarize research on hair cell death and regeneration using fish models, indicate the potential strengths and weaknesses of these models, and discuss several emerging areas of future studies.

  19. Regeneration of sulfur-fouled bimetallic Pd-based catalysts.

    Science.gov (United States)

    Chaplin, Brian P; Shapley, John R; Werth, Charles J

    2007-08-01

    Pd-based catalysts provide efficient and selective reduction of several drinking water contaminants, but their long-term application requires effective treatments for catalyst regeneration following fouling by constituents in natural waters. This studytested alumina-supported Pd-Cu and Pd-In bimetallic catalysts for nitrate reduction with H2 after sulfide fouling and oxidative regeneration procedures. Both catalysts were severely deactivated after treatment with microM levels of sulfide. Regeneration was attempted with dissolved oxygen, hydrogen peroxide, sodium hypochlorite, and heated air. Only sodium hypochlorite and heated air were effective regenerants, specifically restoring nitrate reduction rates for a Pd-In/gamma-Al2O3 catalyst from 20% to between 39 and 60% of original levels. Results from ICP-MS revealed that sodium hypochlorite caused dissolution of Cu from the Pd-Cu catalyst but that the Pd-In catalyst was chemically stable over a range of sulfide fouling and oxidative regenerative conditions. Analysis byXPS indicated that PdS and In2S3 complexes form during sulfide fouling, where sulfur is present as S2-, and that regeneration with sodium hypochlorite converts a portion of the S2- to S6+, with a corresponding increase in reduction rates. These results indicate that Pd-In catalysts show exceptional promise for being robust under fouling and regeneration conditions that may occur when treating natural waters.

  20. Applicability of tooth derived stem cells in neural regeneration

    Institute of Scientific and Technical Information of China (English)

    Ludovica Parisi; Edoardo Manfredi

    2016-01-01

    Within the nervous system, regeneration is limited, and this is due to the small amount of neural stem cells, the inhibitory origin of the stem cell niche and otfen to the development of a scar which constitutes a mechanical barrier for the regeneration. Regarding these aspects, many efforts have been done in the re-search of a cell component that combined with scaffolds and growth factors could be suitable for nervous regeneration in regenerative medicine approaches. Autologous mesenchymal stem cells represent nowa-days the ideal candidate for this aim, thank to their multipotency and to their amount inside adult tissues. However, issues in their harvesting, through the use of invasive techniques, and problems involved in their ageing, require the research of new autologous sources. To this purpose, the recent discovery of a stem cells component in teeth, and which derive from neural crest cells, has came to the light the possibility of using dental stem cells in nervous system regeneration. In this work, in order to give guidelines on the use of dental stem cells for neural regeneration, we brielfy introduce the concepts of regeneration and regenerative medicine, we then focus the attention on odontogenesis, which involves the formation and the presence of a stem component in different parts of teeth, and ifnally we describe some experimental approaches which are exploiting dental stem cells for neural studies.

  1. Mitochondria Localize to Injured Axons to Support Regeneration.

    Science.gov (United States)

    Han, Sung Min; Baig, Huma S; Hammarlund, Marc

    2016-12-21

    Axon regeneration is essential to restore the nervous system after axon injury. However, the neuronal cell biology that underlies axon regeneration is incompletely understood. Here we use in vivo, single-neuron analysis to investigate the relationship between nerve injury, mitochondrial localization, and axon regeneration. Mitochondria translocate into injured axons so that average mitochondria density increases after injury. Moreover, single-neuron analysis reveals that axons that fail to increase mitochondria have poor regeneration. Experimental alterations to axonal mitochondrial distribution or mitochondrial respiratory chain function result in corresponding changes to regeneration outcomes. Axonal mitochondria are specifically required for growth-cone migration, identifying a key energy challenge for injured neurons. Finally, mitochondrial localization to the axon after injury is regulated in part by dual-leucine zipper kinase 1 (DLK-1), a conserved regulator of axon regeneration. These data identify regulation of axonal mitochondria as a new cell-biological mechanism that helps determine the regenerative response of injured neurons. Copyright © 2016 Elsevier Inc. All rights reserved.

  2. Periodontal regeneration: a challenge for the tissue engineer?

    Science.gov (United States)

    Hughes, F J; Ghuman, M; Talal, A

    2010-12-01

    Periodontitis affects around 15 per cent of human adult populations. While periodontal treatment aimed at removing the bacterial cause of the disease is generally very successful, the ability predictably to regenerate the damaged tissues remains a major unmet objective for new treatment strategies. Existing treatments include the use of space-maintaining barrier membranes (guided tissue regeneration), use of graft materials, and application of bioactive molecules to induce regeneration, but their overall effects are relatively modest and restricted in application. The periodontal ligament is rich in mesenchymal stem cells, and the understanding of the signalling molecules that may regulate their differentation has increased enormously in recent years. Applying these principles for the development of new tissue engineering strategies for periodontal regeneration will require further work to determine the efficacy of current experimental preclinical treatments, including pharmacological application of growth factors such as bone morphogenetic proteins (BMPs) or Wnts, use of autologous stem cell reimplantation strategies, and development of improved biomaterial scaffolds. This article describes the background to this problem, addresses the current status of periodontal regeneration, including the background biology, and discusses the potential for some of these experimental therapies to achieve the goal of clinically predictable periodontal regeneration.

  3. Applicability of tooth derived stem cells in neural regeneration

    Directory of Open Access Journals (Sweden)

    Ludovica Parisi

    2016-01-01

    Full Text Available Within the nervous system, regeneration is limited, and this is due to the small amount of neural stem cells, the inhibitory origin of the stem cell niche and often to the development of a scar which constitutes a mechanical barrier for the regeneration. Regarding these aspects, many efforts have been done in the research of a cell component that combined with scaffolds and growth factors could be suitable for nervous regeneration in regenerative medicine approaches. Autologous mesenchymal stem cells represent nowadays the ideal candidate for this aim, thank to their multipotency and to their amount inside adult tissues. However, issues in their harvesting, through the use of invasive techniques, and problems involved in their ageing, require the research of new autologous sources. To this purpose, the recent discovery of a stem cells component in teeth, and which derive from neural crest cells, has came to the light the possibility of using dental stem cells in nervous system regeneration. In this work, in order to give guidelines on the use of dental stem cells for neural regeneration, we briefly introduce the concepts of regeneration and regenerative medicine, we then focus the attention on odontogenesis, which involves the formation and the presence of a stem component in different parts of teeth, and finally we describe some experimental approaches which are exploiting dental stem cells for neural studies.

  4. Genetic evidence for shared mechanisms of epimorphic regeneration in zebrafish.

    Science.gov (United States)

    Qin, Zhao; Barthel, Linda K; Raymond, Pamela A

    2009-06-09

    In a microarray-based gene profiling analysis of Müller glia-derived retinal stem cells in light-damaged retinas from adult zebrafish, we found that 2 genes required for regeneration of fin and heart tissues in zebrafish, hspd1 (heat shock 60-kDa protein 1) and mps1 (monopolar spindle 1), were up-regulated. Expression of both genes in the neurogenic Müller glia and progenitors was independently verified by quantitative reverse transcriptase PCR and in situ hybridization. Functional analysis of temperature-sensitive mutants of hspd1 and mps1 revealed that both are necessary for Müller glia-based cone photoreceptor regeneration in adult zebrafish retina. In the amputated fin, hspd1 is required for the induction of mesenchymal stem cells and blastema formation, whereas mps1 is required at a later step for rapid cell proliferation and outgrowth. This temporal sequence of hspd1 and mps1 function is conserved in the regenerating retina. Comparison of gene expression profiles from regenerating zebrafish retina, caudal fin, and heart muscle revealed additional candidate genes potentially implicated in injury-induced epimorphic regeneration in diverse zebrafish tissues.

  5. The Architectural Practice of Regeneration

    Directory of Open Access Journals (Sweden)

    Tom Van Malderen

    2013-09-01

    Full Text Available In form and in content, cities are the epitome of diversity. This state is the result of the accumulation of layers of history, of construction, of demolition and reconstruction cycles. These tensions are the catalyst for the emergence of new urban forms and participate in the construction of heritage. As such they should be encouraged. As important as the existing fabric of the city is, its evolution to accommodate the ever-changing needs and fashions of its inhabitants is paramount. For regeneration to be successful it must inscribe itself in this process and it must be driven by an understanding of the environment where it occurs. This paper explores, through the lens of an architectural practice, some design processes and architectural proposals that have been generated by working on the Valletta harbours. It also discusses the necessary dynamics required to accommodate stakeholder engagement and planning policy while ensuring design quality and the perpetuation of the creative process inherent to the city. Finally, the paper introduces, as a possible future, the experiments and studies of the practice on the wider Valletta, putting into perspective the benefits of theoretical research combined with formal and aesthetic explorations of the harbour region.

  6. Tissue Regeneration: A Silk Road

    Science.gov (United States)

    Jao, Dave; Mou, Xiaoyang; Hu, Xiao

    2016-01-01

    Silk proteins are natural biopolymers that have extensive structural possibilities for chemical and mechanical modifications to facilitate novel properties, functions, and applications in the biomedical field. The versatile processability of silk fibroins (SF) into different forms such as gels, films, foams, membranes, scaffolds, and nanofibers makes it appealing in a variety of applications that require mechanically superior, biocompatible, biodegradable, and functionalizable biomaterials. There is no doubt that nature is the world’s best biological engineer, with simple, exquisite but powerful designs that have inspired novel technologies. By understanding the surface interaction of silk materials with living cells, unique characteristics can be implemented through structural modifications, such as controllable wettability, high-strength adhesiveness, and reflectivity properties, suggesting its potential suitability for surgical, optical, and other biomedical applications. All of the interesting features of SF, such as tunable biodegradation, anti-bacterial properties, and mechanical properties combined with potential self-healing modifications, make it ideal for future tissue engineering applications. In this review, we first demonstrate the current understanding of the structures and mechanical properties of SF and the various functionalizations of SF matrices through chemical and physical manipulations. Then the diverse applications of SF architectures and scaffolds for different regenerative medicine will be discussed in detail, including their current applications in bone, eye, nerve, skin, tendon, ligament, and cartilage regeneration. PMID:27527229

  7. Tissue Regeneration: A Silk Road.

    Science.gov (United States)

    Jao, Dave; Mou, Xiaoyang; Hu, Xiao

    2016-01-01

    Silk proteins are natural biopolymers that have extensive structural possibilities for chemical and mechanical modifications to facilitate novel properties, functions, and applications in the biomedical field. The versatile processability of silk fibroins (SF) into different forms such as gels, films, foams, membranes, scaffolds, and nanofibers makes it appealing in a variety of applications that require mechanically superior, biocompatible, biodegradable, and functionalizable biomaterials. There is no doubt that nature is the world's best biological engineer, with simple, exquisite but powerful designs that have inspired novel technologies. By understanding the surface interaction of silk materials with living cells, unique characteristics can be implemented through structural modifications, such as controllable wettability, high-strength adhesiveness, and reflectivity properties, suggesting its potential suitability for surgical, optical, and other biomedical applications. All of the interesting features of SF, such as tunable biodegradation, anti-bacterial properties, and mechanical properties combined with potential self-healing modifications, make it ideal for future tissue engineering applications. In this review, we first demonstrate the current understanding of the structures and mechanical properties of SF and the various functionalizations of SF matrices through chemical and physical manipulations. Then the diverse applications of SF architectures and scaffolds for different regenerative medicine will be discussed in detail, including their current applications in bone, eye, nerve, skin, tendon, ligament, and cartilage regeneration.

  8. An experimental study of passive regenerator geometries

    DEFF Research Database (Denmark)

    Engelbrecht, Kurt; Nielsen, Kaspar Kirstein; Pryds, Nini

    2011-01-01

    this article studies the effects of regenerator geometry on performance for flat plate regenerators. This paper investigates methods of improving the performance of flat plate regenerators for use in AMR systems and studies how manufacturing variation affects regenerator performance. In order to eliminate...... experimental uncertainty associated with magnetocaloric material properties, all regenerators are made of aluminum. The performance of corrugated plates and dimpled plates are compared to traditional flat plate regenerators for a range of cycle times and utilizations. Each regenerator is built using 18...

  9. Automated renal histopathology: digital extraction and quantification of renal pathology

    Science.gov (United States)

    Sarder, Pinaki; Ginley, Brandon; Tomaszewski, John E.

    2016-03-01

    The branch of pathology concerned with excess blood serum proteins being excreted in the urine pays particular attention to the glomerulus, a small intertwined bunch of capillaries located at the beginning of the nephron. Normal glomeruli allow moderate amount of blood proteins to be filtered; proteinuric glomeruli allow large amount of blood proteins to be filtered. Diagnosis of proteinuric diseases requires time intensive manual examination of the structural compartments of the glomerulus from renal biopsies. Pathological examination includes cellularity of individual compartments, Bowman's and luminal space segmentation, cellular morphology, glomerular volume, capillary morphology, and more. Long examination times may lead to increased diagnosis time and/or lead to reduced precision of the diagnostic process. Automatic quantification holds strong potential to reduce renal diagnostic time. We have developed a computational pipeline capable of automatically segmenting relevant features from renal biopsies. Our method first segments glomerular compartments from renal biopsies by isolating regions with high nuclear density. Gabor texture segmentation is used to accurately define glomerular boundaries. Bowman's and luminal spaces are segmented using morphological operators. Nuclei structures are segmented using color deconvolution, morphological processing, and bottleneck detection. Average computation time of feature extraction for a typical biopsy, comprising of ~12 glomeruli, is ˜69 s using an Intel(R) Core(TM) i7-4790 CPU, and is ~65X faster than manual processing. Using images from rat renal tissue samples, automatic glomerular structural feature estimation was reproducibly demonstrated for 15 biopsy images, which contained 148 individual glomeruli images. The proposed method holds immense potential to enhance information available while making clinical diagnoses.

  10. A Microfabricated Segmented-Involute-Foil Regenerator for Enhancing Reliability and Performance of Stirling Engines

    Science.gov (United States)

    Ibrahim, Mounir; Danila, Daniel; Simon, Terrence; Mantell, Susan; Sun, Liyong; Gadeon, David; Qiu, Songgang; Wood, Gary; Kelly, Kevin; McLean, Jeffrey

    2007-01-01

    An actual-size microfabricated regenerator comprised of a stack of 42 disks, 19 mm diameter and 0.25 mm thick, with layers of microscopic, segmented, involute-shaped flow channels was fabricated and tested. The geometry resembles layers of uniformly-spaced segmented-parallel-plates, except the plates are curved. Each disk was made from electro-plated nickel using the LiGA process. This regenerator had feature sizes close to those required for an actual Stirling engine but the overall regenerator dimensions were sized for the NASA/Sunpower oscillating-flow regenerator test rig. Testing in the oscillating-flow test rig showed the regenerator performed extremely well, significantly better than currently used random-fiber material, producing the highest figures of merit ever recorded for any regenerator tested in that rig over its approximately 20 years of use.

  11. Direct regeneration of recycled cathode material mixture from scrapped LiFePO4 batteries

    Science.gov (United States)

    Li, Xuelei; Zhang, Jin; Song, Dawei; Song, Jishun; Zhang, Lianqi

    2017-03-01

    A new green recycling process (named as direct regeneration process) of cathode material mixture from scrapped LiFePO4 batteries is designed for the first time. Through this direct regeneration process, high purity cathode material mixture (LiFePO4 + acetylene black), anode material mixture (graphite + acetylene black) and other by-products (shell, Al foil, Cu foil and electrolyte solvent, etc.) are recycled from scrapped LiFePO4 batteries with high yield. Subsequently, recycled cathode material mixture without acid leaching is further directly regenerated with Li2CO3. Direct regeneration procedure of recycled cathode material mixture from 600 to 800 °C is investigated in detail. Cathode material mixture regenerated at 650 °C display excellent physical, chemical and electrochemical performances, which meet the reuse requirement for middle-end Li-ion batteries. The results indicate the green direct regeneration process with low-cost and high added-value is feasible.

  12. Pulmonary-Renal Syndrome with a Focus on Anti-GBM Disease

    NARCIS (Netherlands)

    Sanders, Jan-Stephan F.; Rutgers, Abraham; Stegeman, Coen A; Kallenberg, Cees G.M.

    Pulmonary-renal syndrome is a potentially life-threatening combination of pulmonary hemorrhage and acute renal failure. Several pathological entities can cause this syndrome. This review discusses the diagnostic strategy required to initiate appropriate therapy. Rapid serological testing and

  13. Refractory anemia leading to renal hemosiderosis and renal failure

    OpenAIRE

    Sujatha Siddappa; K M Mythri; Kowsalya, R.; Ashish Parekh

    2011-01-01

    Renal hemosiderosis is a rare cause of renal failure and, as a result, may not be diagnosed unless a detailed history, careful interpretation of blood parameters and renal biopsy with special staining is done. Here, we present a rare case of renal hemosiderosis presenting with renal failure.

  14. Refractory anemia leading to renal hemosiderosis and renal failure

    Directory of Open Access Journals (Sweden)

    Sujatha Siddappa

    2011-01-01

    Full Text Available Renal hemosiderosis is a rare cause of renal failure and, as a result, may not be diagnosed unless a detailed history, careful interpretation of blood parameters and renal biopsy with special staining is done. Here, we present a rare case of renal hemosiderosis presenting with renal failure.

  15. Intestinal parasitic infections in renal transplant recipients

    Directory of Open Access Journals (Sweden)

    Mehdi Azami

    2010-02-01

    Full Text Available The impact of intestinal parasitic infection in renal transplant recipients requires careful consideration in the developing world. However, there have been very few studies addressing this issue in Iran. This study was conducted to determine the prevalence of intestinal parasitic infections in renal transplant recipients in Iran. Stool specimens from renal transplant recipients and control groups were obtained between June 2006 and January 2007. The samples screened for intestinal parasitic infections using direct smear, formalin-ether sedimentation, Sheather's flotation and modified Ziehl-Neelsen staining methods. Out of 150 renal transplant recipients, 33.3% (50, and out of 225 control group, 20% (45 were infected with one or more type of intestinal parasites. The parasites detected among patients included Entamoeba coli (10.6%, Endolimax nana (8.7%, Giardia lamblia (7.4%, Blastocystis spp. (4.7%, Iodamoeba butschlii (0.7%, Chilomastix mesnili (0.7% and Ascaris lumbricoides (0.7%. Multiple infections were more common among renal transplant recipients group (p < 0.05. This study highlights the importance of testing for intestinal parasites among Iranian renal transplant recipients. Routine examinations of stool samples for parasites would significantly benefit the renal transplant recipients by contributing to reduce severe infections.

  16. Intestinal parasitic infections in renal transplant recipients

    Directory of Open Access Journals (Sweden)

    Mehdi Azami

    Full Text Available The impact of intestinal parasitic infection in renal transplant recipients requires careful consideration in the developing world. However, there have been very few studies addressing this issue in Iran. This study was conducted to determine the prevalence of intestinal parasitic infections in renal transplant recipients in Iran. Stool specimens from renal transplant recipients and control groups were obtained between June 2006 and January 2007. The samples screened for intestinal parasitic infections using direct smear, formalin-ether sedimentation, Sheather's flotation and modified Ziehl-Neelsen staining methods. Out of 150 renal transplant recipients, 33.3% (50, and out of 225 control group, 20% (45 were infected with one or more type of intestinal parasites. The parasites detected among patients included Entamoeba coli (10.6%, Endolimax nana (8.7%, Giardia lamblia (7.4%, Blastocystis spp. (4.7%, Iodamoeba butschlii (0.7%, Chilomastix mesnili (0.7% and Ascaris lumbricoides (0.7%. Multiple infections were more common among renal transplant recipients group (p < 0.05. This study highlights the importance of testing for intestinal parasites among Iranian renal transplant recipients. Routine examinations of stool samples for parasites would significantly benefit the renal transplant recipients by contributing to reduce severe infections.

  17. Regenerable Contaminant Removal System Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The Regenerable Contaminant Removal System (RCRS) is an innovative method to remove sulfur and halide compounds from contaminated gas streams to part-per-billion...

  18. A numerical method of regenerator

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Shaowei [Aisin Seiki Co. Ltd., Aichi (Japan); Matsubara, Yoichi [Nihon Univ., Chiba (Japan). Inst. of Quantum Science

    2004-02-01

    A numerical method for regenerators is introduced in this paper. It is not only suitable for the regenerators in cryocoolers and Stirling engines, but also suitable for the stacks in acoustic engines and the pulse tubes in pulse tube refrigerators. The numerical model is one dimensional periodic unsteady flow model. The numerical method is based on the control volume concept with the implicitly solve method. The iteration acceleration method, which considers the one-dimensional periodic unsteady problem as the steady two-dimensional problem, is used for decreasing the calculation time. By this method, the regenerator in an inertance tube pulse tube refrigerator was simulated. The result is useful for understanding how the inefficiency of the regenerator changes with the inertance effect. (author)

  19. A numerical method of regenerator

    Science.gov (United States)

    Zhu, Shaowei; Matsubara, Yoichi

    2004-02-01

    A numerical method for regenerators is introduced in this paper. It is not only suitable for the regenerators in cryocoolers and Stirling engines, but also suitable for the stacks in acoustic engines and the pulse tubes in pulse tube refrigerators. The numerical model is one dimensional periodic unsteady flow model. The numerical method is based on the control volume concept with the implicitly solve method. The iteration acceleration method, which considers the one-dimensional periodic unsteady problem as the steady two-dimensional problem, is used for decreasing the calculation time. By this method, the regenerator in an inertance tube pulse tube refrigerator was simulated. The result is useful for understanding how the inefficiency of the regenerator changes with the inertance effect.

  20. Instructive function of surface structure of calcium phosphate ceramics in bone regeneration

    NARCIS (Netherlands)

    Zhang, Jingwei

    2016-01-01

    The incidence of patients which require spinal fusion or bone regeneration in large bone defects caused by trauma, tumors, tumor resection, infections or abnormal skeletal development, is on the rise. Traditionally, in both spinal fusion surgery and other bone regeneration approaches, bone grafts

  1. Instructive function of surface structure of calcium phosphate ceramics in bone regeneration

    NARCIS (Netherlands)

    Zhang, Jingwei

    2016-01-01

    The incidence of patients which require spinal fusion or bone regeneration in large bone defects caused by trauma, tumors, tumor resection, infections or abnormal skeletal development, is on the rise. Traditionally, in both spinal fusion surgery and other bone regeneration approaches, bone grafts ar

  2. Severe antenatally diagnosed renal disorders: background, prognosis and practical approach.

    Science.gov (United States)

    Aulbert, Wiebke; Kemper, Markus J

    2016-04-01

    Nowadays most renal disorders, especially urinary tract malformations and renal cystic disease, are diagnosed antenatally. In cases of severe bilateral disease, intrauterine renal dysfunction may lead to renal oligohydramnios (ROH), resulting in pulmonary hypoplasia which affects perinatal mortality and morbidity as well as the long-term outcome. However, some infants may only have mild pulmonary and renal disease, and advances in postnatal and dialysis treatment have resulted in improved short- and long-term outcome even in those infants with severe ROH. Here, we review the current state of knowledge and clinical experience of patients presenting antenatally with severe bilateral renal disorders and ROH. By addressing underlying mechanisms, intrauterine tools of diagnosis and treatment as well as published outcome data, we hope to improve antenatal counselling and postnatal care. KEY SUMMARY POINTS: 1. Nowadays most renal disorders are diagnosed antenatally, especially urinary tract malformations and renal cystic disease. 2. Severe kidney dysfunction may lead to renal oligohydramnios, which can cause pulmonary hypoplasia and is a risk factor of perinatal mortality and postnatal renal outcome. However, as considerable clinical heterogeneity is present, outcome predictions need to be treated with caution. 3. Advances in postnatal and dialysis treatment have resulted in improved short- and long-term outcomes even in infants with severe renal oligohydramnios. 4. A multidisciplinary approach with specialist input is required when counselling a family with an ROH-affected fetus as the decision-making process is very challenging.

  3. Tissue engineering for periodontal regeneration.

    Science.gov (United States)

    Kao, Richard T; Conte, Greg; Nishimine, Dee; Dault, Scott

    2005-03-01

    As a result of periodontal regeneration research, a series of clinical techniques have emerged that permit tissue engineering to be performed for more efficient regeneration and repair of periodontal defects and improved implant site development. Historically, periodontal regeneration research has focused on a quest for "magic filler" material. This search has led to the development of techniques utilizing autologous bone and bone marrow, allografts, xenografts, and various man-made bone substitutes. Though these techniques have had limited success, the desire for a more effective regenerative approach has resulted in the development of tissue engineering techniques. Tissue engineering is a relatively new field of reconstructive biology which utilizes mechanical, cellular, or biologic mediators to facilitate reconstruction/regeneration of a particular tissue. In periodontology, the concept of tissue engineering had its beginnings with guided tissue regeneration, a mechanical approach utilizing nonresorbable membranes to obtain regeneration in defects. In dental implantology, guided bone regeneration membranes +/- mechanical support are used for bone augmentation of proposed implant placement sites. With the availability of partially purified protein mixture from developing teeth and growth factors from recombinant technology, a new era of tissue engineering whereby biologic mediators can be used for periodontal regeneration. The advantage of recombinant growth factors is this tissue engineering device is consistent in its regenerative capacity, and variations in regenerative response are due to individual healing response and/or poor surgical techniques. In this article, the authors review how tissue engineering has advanced and discuss its impact on the clinical management of both periodontal and osseous defects in preparation for implant placement. An understanding of these new tissue engineering techniques is essential for comprehending today's ever

  4. Nerves Regulate Cardiomyocyte Proliferation and Heart Regeneration

    OpenAIRE

    Mahmoud, Ahmed I.; O’Meara, Caitlin C.; Gemberling, Matthew; Zhao, Long; Bryant, Donald M.; Zheng, Ruimao; Gannon, Joseph B.; Cai, Lei; Choi, Wen-Yee; Egnaczyk, Gregory F.; Burns, Caroline E.; Burns, C. Geoffrey; MacRae, Calum A.; Poss, Kenneth D.; Lee, Richard T.

    2015-01-01

    Some organisms, such as adult zebrafish and newborn mice, have the capacity to regenerate heart tissue following injury. Unraveling the mechanisms of heart regeneration is fundamental to understanding why regeneration fails in adult humans. Numerous studies have revealed that nerves are crucial for organ regeneration, thus we aimed to determine whether nerves guide heart regeneration. Here, we show using transgenic zebrafish that inhibition of cardiac innervation leads to reduction of myocyte...

  5. Renal function after renal artery stenting

    Institute of Scientific and Technical Information of China (English)

    George S. Hanzel; Mark Downes; Peter A. McCullough

    2005-01-01

    @@ Atherosclerotic renal artery stenosis (ARAS), a common clinical finding, is increasing in prevalence as the population ages. ARAS is seen in ~ 7% of persons over 65 years of age1 and in ~ 20% of patients at the time of coronary angiography.2 It is an important cause of chronic kidney disease and may result in 11-14% of cases of end stage renal disease.3

  6. Transforming growth factor: beta signaling is essential for limb regeneration in axolotls.

    Directory of Open Access Journals (Sweden)

    Mathieu Lévesque

    Full Text Available Axolotls (urodele amphibians have the unique ability, among vertebrates, to perfectly regenerate many parts of their body including limbs, tail, jaw and spinal cord following injury or amputation. The axolotl limb is the most widely used structure as an experimental model to study tissue regeneration. The process is well characterized, requiring multiple cellular and molecular mechanisms. The preparation phase represents the first part of the regeneration process which includes wound healing, cellular migration, dedifferentiation and proliferation. The redevelopment phase represents the second part when dedifferentiated cells stop proliferating and redifferentiate to give rise to all missing structures. In the axolotl, when a limb is amputated, the missing or wounded part is regenerated perfectly without scar formation between the stump and the regenerated structure. Multiple authors have recently highlighted the similarities between the early phases of mammalian wound healing and urodele limb regeneration. In mammals, one very important family of growth factors implicated in the control of almost all aspects of wound healing is the transforming growth factor-beta family (TGF-beta. In the present study, the full length sequence of the axolotl TGF-beta1 cDNA was isolated. The spatio-temporal expression pattern of TGF-beta1 in regenerating limbs shows that this gene is up-regulated during the preparation phase of regeneration. Our results also demonstrate the presence of multiple components of the TGF-beta signaling machinery in axolotl cells. By using a specific pharmacological inhibitor of TGF-beta type I receptor, SB-431542, we show that TGF-beta signaling is required for axolotl limb regeneration. Treatment of regenerating limbs with SB-431542 reveals that cellular proliferation during limb regeneration as well as the expression of genes directly dependent on TGF-beta signaling are down-regulated. These data directly implicate TGF

  7. A wound-induced Wnt expression program controls planarian regeneration polarity.

    Science.gov (United States)

    Petersen, Christian P; Reddien, Peter W

    2009-10-06

    Regeneration requires specification of the identity of new tissues to be made. Whether this process relies only on intrinsic regulative properties of regenerating tissues or whether wound signaling provides input into tissue repatterning is not known. The head-versus-tail regeneration polarity decision in planarians, which requires Wnt signaling, provides a paradigm to study the process of tissue identity specification during regeneration. The Smed-wntP-1 gene is required for regeneration polarity and is expressed at the posterior pole of intact animals. Surprisingly, wntP-1 was expressed at both anterior- and posterior-facing wounds rapidly after wounding. wntP-1 expression was induced by all types of wounds examined, regardless of whether wounding prompted tail regeneration. Regeneration polarity was found to require new expression of wntP-1. Inhibition of the wntP-2 gene enhanced the polarity phenotype due to wntP-1 inhibition, with new expression of wntP-2 in regeneration occurring subsequent to expression of wntP-1 and localized only to posterior-facing wounds. New expression of wntP-2 required wound-induced wntP-1. Finally, wntP-1 and wntP-2 expression changes occurred even in the absence of neoblast stem cells, which are required for regeneration, suggesting that the role of these genes in polarity is independent of and instructive for tail formation. These data indicate that wound-induced input is involved in resetting the normal polarized features of the body axis during regeneration.

  8. Primary and secondary genetic responses after folic acid-induced acute renal injury in the mouse.

    Science.gov (United States)

    Calvet, J P; Chadwick, L J

    1994-12-01

    Folic acid-induced acute renal injury results in dramatic changes in gene expression. Among the genes affected by folic acid treatment are the primary response genes, c-fos and c-myc, which are thought to function to initiate cell cycle events. In this report, changes in the expression of three other genes in response to folic acid injury have been investigated: ornithine decarboxylase, epidermal growth factor (EGF), and sulfated glycoprotein-2 (SGP-2). Renal injury was found to cause a rapid decrease in EGF mRNA, which remained absent for several days after the initial injury, gradually returning to normal levels over an approximately 3-wk regeneration and recovery period. Ornithine decarboxylase mRNA showed a similar decrease. In contrast, folic acid caused a rapid increase in SGP-2 mRNA, which peaked several days after treatment, decreasing to normal levels over the 3-wk period. The mRNAs for the primary response genes were superinduced in the injured kidneys in the presence of the protein synthesis inhibitor cycloheximide. In contrast, the changes in EGF and SGP-2 mRNA levels were blocked by cycloheximide, indicating that these responses required new protein synthesis during the first few hours after folic acid injury. The opposite but parallel responses in the expression of the EGF and SGP-2 genes suggest that their regulation is coupled to the initial injury-induced dedifferentiation and subsequent return to the fully differentiated state.

  9. Forward osmosis process for dialysis fluid regeneration.

    Science.gov (United States)

    Talaat, Khaled Mohamed

    2009-12-01

    In a preliminary experiment, 38% of the spent dialysis fluid water was reclaimed by a forward osmosis process through a cellulose triacetate membrane. The simplicity of forward osmosis and its minimal external energy requirements may allow the construction of a small bulk device that can reclaim a considerable portion of the water used in the patient's dialysis process. For developing an acceptable ambulatory dialysis system, decreasing the bulk of the fluid and equipment carried on the patient is essential. Forward osmosis may feasibly be used for dialysis fluid regeneration in ambulatory dialysis systems.

  10. Evaluation of renal artery stenosis using color Doppler sonography in young patients with multiple renal arteries

    Institute of Scientific and Technical Information of China (English)

    QIN Wei; ZHANG Xin; YANG Min; ZHONG Xu-hui; ZHAO Ming-hui

    2011-01-01

    Background Some individuals have multiple renal arteries. Severe stenosis in one of the arteries may cause refractory hypertension. The detection of stenosis within one of the multiple renal arteries usually required invasive procedures, such as computed tomographic angiography (CTA) and magnetic resonance angiography (MRA). This study reported the application of color Doppler sonography (CDS) in the detection of severe stenosis in one of the multiple arteries.Methods Patients with multiple renal arteries and one of the arteries with severe stenosis were retrospectively studied. Peak systolic velocities (PSV) of renal arteries and the intrarenal CDS patterns were collected and compared. The diagnosis was confirmed by digital subtraction angiography (DSA).Results Four children with multiple renal arteries and one of the arteries with stenosis were investigated. They were admitted due to refractory hypertension. CDS screening identified two renal arteries in one kidney of each patient with one of the two renal arteries having stenosis >70%. The PSV of the stenosed arteries were much higher, and the intrarenal CDS patterns supplied by the stenosed arteries changed into T-P patterns.Conclusion Non-invasive CDS technology may be a useful method to identify severe stenosis in one of multiple renal arteries in young patients.

  11. Live-cell imaging: new avenues to investigate retinal regeneration.

    Science.gov (United States)

    Lahne, Manuela; Hyde, David R

    2017-08-01

    Sensing and responding to our environment requires functional neurons that act in concert. Neuronal cell loss resulting from degenerative diseases cannot be replaced in humans, causing a functional impairment to integrate and/or respond to sensory cues. In contrast, zebrafish (Danio rerio) possess an endogenous capacity to regenerate lost neurons. Here, we will focus on the processes that lead to neuronal regeneration in the zebrafish retina. Dying retinal neurons release a damage signal, tumor necrosis factor α, which induces the resident radial glia, the Müller glia, to reprogram and re-enter the cell cycle. The Müller glia divide asymmetrically to produce a Müller glia that exits the cell cycle and a neuronal progenitor cell. The arising neuronal progenitor cells undergo several rounds of cell divisions before they migrate to the site of damage to differentiate into the neuronal cell types that were lost. Molecular and immunohistochemical studies have predominantly provided insight into the mechanisms that regulate retinal regeneration. However, many processes during retinal regeneration are dynamic and require live-cell imaging to fully discern the underlying mechanisms. Recently, a multiphoton imaging approach of adult zebrafish retinal cultures was developed. We will discuss the use of live-cell imaging, the currently available tools and those that need to be developed to advance our knowledge on major open questions in the field of retinal regeneration.

  12. Live-cell imaging: new avenues to investigate retinal regeneration

    Directory of Open Access Journals (Sweden)

    Manuela Lahne

    2017-01-01

    Full Text Available Sensing and responding to our environment requires functional neurons that act in concert. Neuronal cell loss resulting from degenerative diseases cannot be replaced in humans, causing a functional impairment to integrate and/or respond to sensory cues. In contrast, zebrafish (Danio rerio possess an endogenous capacity to regenerate lost neurons. Here, we will focus on the processes that lead to neuronal regeneration in the zebrafish retina. Dying retinal neurons release a damage signal, tumor necrosis factor α, which induces the resident radial glia, the Müller glia, to reprogram and re-enter the cell cycle. The Müller glia divide asymmetrically to produce a Müller glia that exits the cell cycle and a neuronal progenitor cell. The arising neuronal progenitor cells undergo several rounds of cell divisions before they migrate to the site of damage to differentiate into the neuronal cell types that were lost. Molecular and immunohistochemical studies have predominantly provided insight into the mechanisms that regulate retinal regeneration. However, many processes during retinal regeneration are dynamic and require live-cell imaging to fully discern the underlying mechanisms. Recently, a multiphoton imaging approach of adult zebrafish retinal cultures was developed. We will discuss the use of live-cell imaging, the currently available tools and those that need to be developed to advance our knowledge on major open questions in the field of retinal regeneration.

  13. Renal Replacement Therapy in Austere Environments

    Directory of Open Access Journals (Sweden)

    Christina M. Yuan

    2011-01-01

    Full Text Available Myoglobinuric renal failure is the classically described acute renal event occurring in disaster environments—commonly after an earthquake—which most tests the ingenuity and flexibility of local and regional nephrology resources. In recent decades, several nephrology organizations have developed response teams and planning protocols to address disaster events, largely focusing on patients at risk for, or with, acute kidney injury (AKI. In this paper we briefly review the epidemiology and outcomes of patients with dialysis-requiring AKI after such events, while providing greater focus on the management of the end-stage renal disease population after a disaster which incapacitates a pre-existing nephrologic infrastructure (if it existed at all. “Austere” dialysis, as such, is defined as the provision of renal replacement therapy in any setting in which traditional, first-world therapies and resources are limited, incapacitated, or nonexistent.

  14. Imaging of renal osteodystrophy

    Energy Technology Data Exchange (ETDEWEB)

    Jevtic, V. E-mail: vladimir.jevtic@mf.uni-lj.si

    2003-05-01

    Chronic renal insufficiency, hemodialysis, peritoneal dialysis, renal transplantation and administration of different medications provoke complex biochemical disturbances of the calcium-phosphate metabolism with wide spectrum of bone and soft tissue abnormalities termed renal osteodystrophy. Clinically most important manifestation of renal bone disease includes secondary hyperparathyroidism, osteomalacia/rickets, osteoporosis, adynamic bone disease and soft tissue calcification. As a complication of long-term hemodialysis and renal transplantation amyloid deposition, destructive spondyloarthropathy, osteonecrosis, and musculoskeletal infections may occur. Due to more sophisticated diagnostic methods and more efficient treatment classical radiographic features of secondary hyperparathyroidism and osteomalacia/rickets are now less frequently seen. Radiological investigations play an important role in early diagnosis and follow-up of the renal bone disease. Although numerous new imaging modalities have been introduced in clinical practice (scintigraphy, CT, MRI, quantitative imaging), plain film radiography, especially fine quality hand radiograph, still represents most widely used examination.

  15. Unilateral Renal Ischemia as a Model of Acute Kidney Injury and Renal Fibrosis in Cats.

    Science.gov (United States)

    Schmiedt, C W; Brainard, B M; Hinson, W; Brown, S A; Brown, C A

    2016-01-01

    The objectives of this study were to define the acute and chronic effects of 1-hour unilateral in vivo renal ischemia on renal function and histology in cats. Twenty-one adult purpose-bred research cats were anesthetized, and 1 kidney underwent renal artery and vein occlusion for 1 hour. Serum creatinine and urea concentrations, urine protein:creatinine ratio, urine-specific gravity, glomerular filtration rate, hematocrit, platelet concentration and function, and white blood cell count were measured at baseline and variable time points after ischemia. Renal histopathology was evaluated on days 3, 6, 12, 21, 42, and 70 postischemia; changes in smooth muscle actin and interstitial collagen were examined. Following ischemia, whole animal glomerular filtration rate was significantly reduced (57% of baseline on day 6; P acute epithelial necrosis accompanied by evidence of regeneration of tubules predominantly within the corticomedullary junction. At later periods, postischemic kidneys had evidence of tubular atrophy and interstitial inflammation with significantly more smooth muscle actin and interstitial collagen staining and interstitial fibrosis when compared with the contralateral control kidneys. This study characterizes the course of ischemic acute kidney injury in cats and demonstrates that ischemic acute kidney injury triggers chronic fibrosis, interstitial inflammation, and tubular atrophy in feline kidneys. These late changes are typical of those observed in cats with naturally occurring chronic kidney disease.

  16. A case of scrub typhus requiring maintenance hemodialysis

    Directory of Open Access Journals (Sweden)

    Dae-Yeon Kim

    2013-12-01

    Full Text Available Renal failure caused by scrub typhus is known to be reversible. In most cases, renal function is almost fully restored after appropriate antibiotic treatment. A 71-year-old man was diagnosed with scrub typhus complicated by renal failure. A renal biopsy revealed histopathologic findings consistent with acute tubulointerstitial nephritis. Renal function did not improve 18 months after discharge and the patient required continuous hemodialysis. Although severe renal failure requiring dialysis is a rare complication of scrub typhus, we describe a case of scrub typhus requiring maintenance hemodialysis. To the best of our knowledge, this is the first such report.

  17. Successful renal transplantation after recovery from acute disseminated encephalomyelitis in a child with end-stage renal disease

    Directory of Open Access Journals (Sweden)

    Bhosale Guruprasad

    2010-01-01

    Full Text Available Acute disseminated encephalomyelitis (ADEM, seen mostly in children, is an acute demyelinating disease, affecting mainly the white matter of brain and spinal cord. We report an unusual case of ADEM in an 11-year old boy with end-stage renal disease, who underwent hemopoietic stem cell transplantation prior to renal transplantation. He needed admission to the intensive care unit and required mechanical ventilation. He responded to intravenous injection of steroids and upon recovery, underwent renal transplantation successfully.

  18. Incidental renal neoplasms

    DEFF Research Database (Denmark)

    Rabjerg, Maj; Mikkelsen, Minne Nedergaard; Walter, Steen;

    2014-01-01

    On the basis of associations between tumor size, pathological stage, histological subtype and tumor grade in incidentally detected renal cell carcinoma vs symptomatic renal cell carcinoma, we discussed the need for a screening program of renal cell carcinoma in Denmark. We analyzed a consecutive...... series of 204 patients with renal tumors in 2011 and 2012. The tumors were classified according to detection mode: symptomatic and incidental and compared to pathological parameters. Eighty-nine patients (44%) were symptomatic, 113 (55%) were incidental. Information was not available in two patients...

  19. Insuficiencia renal aguda.

    OpenAIRE

    Carlos Hernán Mejía

    2009-01-01

    Acute renal failure (ARF) is a clinic syndrome characterized by decline in renal function occurring over a short time period. Is a relatively common complication in hospitalized critically ill patients and is associated with high morbidity and mortality. ARF has often a multi-factorial etiology syndrome usually approached diagnostically as pre-renal, post-renal, or intrinsic ARF. Most intrinsic ARF is caused by ischemia or nephrotoxins and is classically associated with acute tubular necrosis...

  20. FGF8 and SHH substitute for anterior-posterior tissue interactions to induce limb regeneration.

    Science.gov (United States)

    Nacu, Eugeniu; Gromberg, Elena; Oliveira, Catarina R; Drechsel, David; Tanaka, Elly M

    2016-05-19

    In salamanders, grafting of a left limb blastema onto a right limb stump yields regeneration of three limbs, the normal limb and two 'supernumerary' limbs. This experiment and other research have shown that the juxtaposition of anterior and posterior limb tissue plus innervation are necessary and sufficient to induce complete limb regeneration in salamanders. However, the cellular and molecular basis of the requirement for anterior-posterior tissue interactions were unknown. Here we have clarified the molecular basis of the requirement for both anterior and posterior tissue during limb regeneration and supernumerary limb formation in axolotls (Ambystoma mexicanum). We show that the two tissues provide complementary cross-inductive signals that are required for limb outgrowth. A blastema composed solely of anterior tissue normally regresses rather than forming a limb, but activation of hedgehog (HH) signalling was sufficient to drive regeneration of an anterior blastema to completion owing to its ability to maintain fibroblast growth factor (FGF) expression, the key signalling activity responsible for blastema outgrowth. In blastemas composed solely of posterior tissue, HH signalling was not sufficient to drive regeneration; however, ectopic expression of FGF8 together with endogenous HH signalling was sufficient. In axolotls, FGF8 is expressed only in the anterior mesenchyme and maintenance of its expression depends on sonic hedgehog (SHH) signalling from posterior tissue. Together, our findings identify key anteriorly and posteriorly localized signals that promote limb regeneration and show that these single factors are sufficient to drive non-regenerating blastemas to complete regeneration with full elaboration of skeletal elements.

  1. Cementum and Periodontal Ligament Regeneration.

    Science.gov (United States)

    Menicanin, Danijela; Hynes, K; Han, J; Gronthos, S; Bartold, P M

    2015-01-01

    The unique anatomy and composition of the periodontium make periodontal tissue healing and regeneration a complex process. Periodontal regeneration aims to recapitulate the crucial stages of wound healing associated with periodontal development in order to restore lost tissues to their original form and function and for regeneration to occur, healing events must progress in an ordered and programmed sequence both temporally and spatially, replicating key developmental events. A number of procedures have been employed to promote true and predictable regeneration of the periodontium. Principally, the approaches are based on the use of graft materials to compensate for the bone loss incurred as a result of periodontal disease, use of barrier membranes for guided tissue regeneration and use of bioactive molecules. More recently, the concept of tissue engineering has been integrated into research and applications of regenerative dentistry, including periodontics, to aim to manage damaged and lost oral tissues, through reconstruction and regeneration of the periodontium and alleviate the shortcomings of more conventional therapeutic options. The essential components for generating effective cellular based therapeutic strategies include a population of multi-potential progenitor cells, presence of signalling molecules/inductive morphogenic signals and a conductive extracellular matrix scaffold or appropriate delivery system. Mesenchymal stem cells are considered suitable candidates for cell-based tissue engineering strategies owing to their extensive expansion rate and potential to differentiate into cells of multiple organs and systems. Mesenchymal stem cells derived from multiple tissue sources have been investigated in pre-clinical animal studies and clinical settings for the treatment and regeneration of the periodontium.

  2. Isolated Renal Hydatidosis Presenting as Renal Mass: A Diagnostic Dilemma

    Directory of Open Access Journals (Sweden)

    Datteswar Hota

    2015-07-01

    Full Text Available Hydatid disease is a parasitic infestation by larval form of Echinococcus granulosus. Isolated renal involvement is extremely rare. There are no specific signs and symptoms of renal hydatidosis. However it may present as palpable mass, flank pain, hematuria, malaise, fever, and hydatiduria or as a complication of it such as infection, abscess, hemorrhage, necrosis and pelviureteric junction obstruction, renal failure etc. Except hydatiduria, none are pathognomonic for renal hydatidosis. There is no literature on renal hydatidosis presenting as renal mass we report 2 cases of isolated renal hydatidosis, which mimicked a renal mass on imaging study.

  3. Distal renal tubular acidosis in recurrent renal stone formers

    DEFF Research Database (Denmark)

    Osther, P J; Hansen, A B; Røhl, H F

    1989-01-01

    (1.1%) had complete distal renal tubular acidosis and 14 (15.5%) incomplete distal renal tubular acidosis. Our results confirm that distal renal tubular acidification defects are associated with a more severe form of stone disease and make distal renal tubular acidosis one of the most frequent...... metabolic disturbances in renal stone formers. Distal renal tubular acidosis (dRTA) was relatively more common in female stone formers and most often found in patients with bilateral stone disease (36%). Since prophylactic treatment in renal stone formers with renal acidification defects is available...

  4. Renal pelvis or ureter cancer

    Science.gov (United States)

    Transitional cell cancer of the renal pelvis or ureter; Kidney cancer - renal pelvis; Ureter cancer ... Cancer can grow in the urine collection system, but it is uncommon. Renal pelvis and ureter cancers ...

  5. a Low Temperature Regenerator Test Facility

    Science.gov (United States)

    Kashani, A.; Helvensteijn, B. P. M.; Feller, J. R.; Salerno, L. J.; Kittel, P.

    2008-03-01

    Testing regenerators presents an interesting challenge. When incorporated into a cryocooler, a regenerator is intimately coupled to the other components: expander, heat exchangers, and compressor. It is difficult to isolate the performance of any single component. We have developed a low temperature test facility that will allow us to separate the performance of the regenerator from the rest of the cryocooler. The purpose of the facility is the characterization of test regenerators using novel materials and/or geometries in temperature ranges down to 15 K. It consists of the following elements: The test column has two regenerators stacked in series. The coldest stage regenerator is the device under test. The warmer stage regenerator contains a stack of stainless steel screen, a well-characterized material. A commercial cryocooler is used to fix the temperatures at both ends of the test regenerator, cooling both heat exchangers flanging the regenerator stack. Heaters allow varying the temperatures and allow measurement of the remaining cooling power, and thus, regenerator effectiveness. A linear compressor delivers an oscillating pressure to the regenerator assembly. An inertance tube and reservoir provide the proper phase difference between mass flow and pressure. This phase shift, along with the imposed temperature differential, simulates the conditions of the test regenerator when used in an actual pulse tube cryocooler. This paper presents development details of the regenerator test facility, and test results on a second stage, stainless steel screen test regenerator.

  6. Signaling Molecules and Pulp Regeneration.

    Science.gov (United States)

    Schmalz, Gottfried; Widbiller, Matthias; Galler, Kerstin M

    2017-09-01

    Signaling molecules play an essential role in tissue engineering because they regulate regenerative processes. Evidence exists from animal studies that single molecules such as members of the transforming growth factor beta superfamily and factors that induce the growth of blood vessels (vascular endothelial growth factor), nerves (brain-derived neurotrophic factor), or fibroblasts (fibroblast growth factor) may induce reparative dentin formation. Mainly the formation of atubular dentin (osteodentin) has been described after the application of single molecules or combinations of recombinant growth factors on healthy exposed pulps or in pulp regeneration. Generally, such preparations have not received regulatory approval on the market so far. Only the use of granulocyte colony-stimulating factors together with cell transplantation is presently tested clinically. Besides approaches with only 1 or few combined molecules, the exploitation of tissue-derived growth factors depicts a third promising way in dental pulp tissue engineering. Preparations such as platelet-rich plasma or platelet-rich fibrin provide a multitude of endogenous signaling molecules, and special regulatory approval for the market does not seem necessary. Furthermore, dentin is a perfect reservoir of signaling molecules that can be mobilized by treatment with demineralizing agents such as EDTA. This conditions the dentin surface and allows for contact differentiation of pulp stem cells into odontoblastlike cells, protects dentin from resorption, and enhances cell growth as well as attachment to dentin. By ultrasonic activation, signaling molecules can be further released from EDTA pretreated dentin into saline, thus avoiding cytotoxic EDTA in the final preparation. The use of dentin-derived growth factors offers a number of advantages because they are locally available and presumably are most fit to induce signaling processes in dental pulp. However, better characterization and standardization of the

  7. Application of dedifferentiated fat cells for periodontal tissue regeneration.

    Science.gov (United States)

    Sugawara, Atsunori; Sato, Soh

    2014-01-01

    Periodontal diseases result from inflammation by bacterial infection in plaques, leading to tooth loss. However, regenerative approaches with periodontal tissue regeneration by guided tissue regeneration and enamel matrix derivative are not yet well established. Tissue regeneration requires three factors: cells, scaffold, and growth factors. Dedifferentiated fat cells (DFATs) are pluripotent with the same differentiation capacities as mesenchymal stem cells (MSCs). Access to MSCs is limited, whereas donor cells for DFATs are abundant in adipose tissues and can be non-invasively obtained. Therefore, we tested DFATs as a new source for periodontal tissue regeneration in an experimental periodontal tissue loss model in rats by transplanting DFATs on an atelocollagen scaffold using DFATs isolated from Sprague-Dawley (SD) rats expressing green fluorescent protein (GFP). GFP-DFAT cells were transplanted on the palatal side of the upper left first molar in SD rats and detected by H&E staining, GFP, and proliferating cell nuclear antigen (PCNA) expression. DFAT differentiation was also evaluated in three-dimensional cultures. GFP positive cells were detected in the regenerated tissue by the DFATs/scaffold mixture at 4 weeks after transplantation, and PCNA-positive cells were significantly increased in the periodontal ligament along the new bone in the DFATs/scaffold group more than in the scaffold-only group, suggesting that DFATs differentiate in the same manner as MSCs and regenerate in the defective areas. Consistent with previous reports, DFATs differentiation was slower than that with stem cells. The present study demonstrates that DFATs are pluripotent and an effective new source of cells for periodontal tissue regeneration.

  8. Regulation and regeneration in the ctenophore Mnemiopsis leidyi.

    Science.gov (United States)

    Henry, J Q; Martindale, M Q

    2000-11-15

    Lobate ctenophores (tentaculates) generally exhibit a remarkable ability to regenerate missing structures as adults. On the other hand, their embryos exhibit a highly mosaic behavior when cut into halves or when specific cells are ablated. These deficient embryos do not exhibit embryonic regulation, and generate incomplete adult body plans. Under certain conditions, however, these deficient animals are subsequently able to replace the missing structures during the adult phase in a process referred to as "post-regeneration." We have determined that successful post-regeneration can be predicted on the basis of a modified polar coordinate model, and the rules of intercalary regeneration, as defined by French et al. (V. French, P. J. Bryant, and S. V. Bryant, 1976, Science 193, 969-981.) The model makes certain assumptions about the organization of the ctenophore body plan that fit well with what we have determined on the basis of cell lineage fates maps, and their twofold rotational ("biradial") symmetry. The results suggest that cells composing the ctenophore adult body plan possess positional information, which is utilized to reconstruct the adult body plan. More specifically, we have found that the progeny of three specific cell lineages are required to support post-regeneration of the comb rows (the e(1), e(2), and m(1) micromeres). Furthermore, post-regeneration of the comb rows involves a suite of cell-cell inductive interactions, which are similar to those that take place during their embryonic formation. The significance of these findings is discussed in terms of the organization of the ctenophore body plan, and the mechanisms involved in cell fate specification. This situation is also contrasted with that of the atentaculate ctenophores, which are unable to undergo post-regeneration. Copyright 2000 Academic Press.

  9. Bone morphogenetic proteins: Periodontal regeneration

    Directory of Open Access Journals (Sweden)

    Subramaniam M Rao

    2013-01-01

    Full Text Available Periodontitis is an infectious inflammatory disease that results in attachment loss and bone loss. Regeneration of the periodontal tissues entails de novo formation of cementum, periodontal ligament, and alveolar bone. Several different approaches are currently being explored to achieve complete, reliable, and reproducible regeneration of periodontal tissues. The therapeutic management of new bone formation is one of the key issues in successful periodontal regeneration. Bone morphogenetic proteins form a unique group of proteins within the transforming growth factor superfamily of genes and have a vital role in the regulation in the bone induction and maintenance. The activity of bone morphogenetic proteins was first identified in the 1960s, but the proteins responsible for bone induction were unknown until the purification and cloning of human bone morphogenetic proteins in the 1980s, because of their osteoinductive potential. Bone morphogenetic proteins have gained a lot of interest as therapeutic agents for treating periodontal defects. A systematic search for data related to the use of bone morphogenetic proteins for the regeneration of periodontal defects was performed to recognize studies on animals and human (PUBMED, MEDLINE, COCHRANE, and Google search. All the studies included showed noticeable regeneration of periodontal tissues with the use of BMP.

  10. Contemporaryperspective on endogenous myocardial regeneration

    Institute of Scientific and Technical Information of China (English)

    2015-01-01

    Considering the complex nature of the adult heart,it is no wonder that innate regenerative processes,while maintaining adequate cardiac function, fall shortin myocardial jeopardy. In spite of these enchaining limitations, cardiac rejuvenation occurs as well asrestricted regeneration. In this review, the backgroundas well as potential mechanisms of endogenousmyocardial regeneration are summarized. We presentand analyze the available evidence in three subsequentsteps. First, we examine the experimental researchdata that provide insights into the mechanisms andorigins of the replicating cardiac myocytes, includingcell populations referred to as cardiac progenitor cells(i.e. , c-kit+ cells). Second, we describe the role ofclinical settings such as acute or chronic myocardialischemia, as initiators of pathways of endogenousmyocardial regeneration. Third, the hitherto conductedclinical studies that examined different approachesof initiating endogenous myocardial regeneration infailing human hearts are analyzed. In conclusion, wepresent the evidence in support of the notion thatregaining cardiac function beyond cellular replacementof dysfunctional myocardium via initiation of innateregenerative pathways could create a new perspectiveand a paradigm change in heart failure therapeutics.Reinitiating cardiac morphogenesis by reintroducingdevelopmental pathways in the adult failing heart mightprovide a feasible way of tissue regeneration. Basedon our hypothesis "embryonic recall", we present firstsupporting evidence on regenerative impulses in themyocardium, as induced by developmental processes.

  11. The developing Xenopus limb as a model for studies on the balance between inflammation and regeneration.

    Science.gov (United States)

    King, Michael W; Neff, Anton W; Mescher, Anthony L

    2012-10-01

    The roles of inflammation and immune cell reactivity triggered by amputation have only recently begun to be addressed in investigations of epimorphic regeneration, although studies of tissue repair in mammals clearly show the importance of the immune system in determining the quality of the repair process. Here, we first review inflammation-related work in non-mammalian systems of epimorphic regeneration which suggests that regeneration of an amputated appendage requires continuous modulation of the local immune response, from the first hours after amputation through the period of blastema patterning. We then present data on the effects of anti-inflammatory and proinflammatory agents on regeneration of larval Xenopus hindlimbs. Treatment with the glucocorticoid beclomethasone immediately after amputation inhibits regeneration in regeneration-complete stage 53 limbs. Other anti-inflammatory agents, including the inhibitors of cyclooxygenase-2 (COX-2) activity celecoxib and diclofenac, applied similarly to larvae amputated at stage 55, when the capacity for limb regeneration is normally being lost, restore regenerative capacity. This suggests that although injury-related events sensitive to glucocorticoids are necessary for regeneration, resolution of the inflammatory response may also be required to allow the complete regenerative response and normal blastema patterning. Conversely, if resolution of inflammation is prevented by local treatment of amputated limbs with beryllium, a strong immunoadjuvant, regeneration is inhibited, and gene expression data suggest that this inhibition results from a failure of normal blastema patterning. Both positive and negative effects of immune- or inflammation-related activities occur during anuran limb regeneration and this underscores the importance of considering immune cells in studies of epimorphic regeneration.

  12. Renal Function Recovery with Total Artificial Heart Support.

    Science.gov (United States)

    Quader, Mohammed A; Goodreau, Adam M; Shah, Keyur B; Katlaps, Gundars; Cooke, Richard; Smallfield, Melissa C; Tchoukina, Inna F; Wolfe, Luke G; Kasirajan, Vigneshwar

    2016-01-01

    Heart failure patients requiring total artificial heart (TAH) support often have concomitant renal insufficiency (RI). We sought to quantify renal function recovery in patients supported with TAH at our institution. Renal function data at 30, 90, and 180 days after TAH implantation were analyzed for patients with RI, defined as hemodialysis supported or an estimated glomerular filtration rate (eGFR) less than 60 ml/min/1.73 m. Between January 2008 and December 2013, 20 of the 46 (43.5%) TAH recipients (age 51 ± 9 years, 85% men) had RI, mean preoperative eGFR of 48 ± 7 ml/min/1.73 m. Renal function recovery was noted at each follow-up interval: increment in eGFR (ml/min/1.73 m) at 30, 90, and 180 days was 21 ± 35 (p = 0.1), 16.5 ± 18 (p = 0.05), and 10 ± 9 (p = 0.1), respectively. Six patients (30%) required preoperative dialysis. Of these, four recovered renal function, one remained on dialysis, and one died. Six patients (30%) required new-onset dialysis. Of these, three recovered renal function and three died. Overall, 75% (15 of 20) of patients' renal function improved with TAH support. Total artificial heart support improved renal function in 75% of patients with pre-existing significant RI, including those who required preoperative dialysis.

  13. Urinary Soluble CD163 in Active Renal Vasculitis

    NARCIS (Netherlands)

    O'Reilly, Vincent P.; Wong, Limy; Kennedy, Claire; Elliott, Louise A.; O'Meachair, Shane; Coughlan, Alice Marie; O'Brien, Eoin C.; Ryan, Michelle M.; Sandoval, Diego; Connolly, Emma; Dekkema, Gerjan J.; Lau, Jiaying; Abdulahad, Wayel H.; Heeringa, Peter; Buckley, Colm; O'Brien, Cathal; Finn, Stephen; Cohen, Clemens D.; Lindemeyer, Maja T.; Hickey, Fionnuala B.; O'Hara, Paul V.; Feighery, Conleth; Moran, Sarah M.; Mellotte, George; Clarkson, Michael R.; Dorman, Anthony J.; Murray, Patrick T.; Little, Mark A.; Sanders, Johannes

    2016-01-01

    A specific biomarker that can separate active renal vasculitis from other causes of renal dysfunction is lacking, with a kidney biopsy often being required. Soluble CD163 (sCD163), shed by monocytes and macrophages, has been reported as a potential biomarker in diseases associated with excessive mac

  14. Urinary Soluble CD163 in Active Renal Vasculitis

    NARCIS (Netherlands)

    O'Reilly, Vincent P.; Wong, Limy; Kennedy, Claire; Elliott, Louise A.; O'Meachair, Shane; Coughlan, Alice Marie; O'Brien, Eoin C.; Ryan, Michelle M.; Sandoval, Diego; Connolly, Emma; Dekkema, Gerjan J.; Lau, Jiaying; Abdulahad, Wayel H.; Heeringa, Peter; Buckley, Colm; O'Brien, Cathal; Finn, Stephen; Cohen, Clemens D.; Lindemeyer, Maja T.; Hickey, Fionnuala B.; O'Hara, Paul V.; Feighery, Conleth; Moran, Sarah M.; Mellotte, George; Clarkson, Michael R.; Dorman, Anthony J.; Murray, Patrick T.; Little, Mark A.; Sanders, Johannes

    2016-01-01

    A specific biomarker that can separate active renal vasculitis from other causes of renal dysfunction is lacking, with a kidney biopsy often being required. Soluble CD163 (sCD163), shed by monocytes and macrophages, has been reported as a potential biomarker in diseases associated with excessive mac

  15. [Hemorrhagic bilateral renal angiomyolipoma].

    Science.gov (United States)

    Benjelloun, Mohamed; Rabii, Redouane; Mezzour, Mohamed Hicham; Joual, Abdenbi; Bennani, Saâd; el Mrini, Mohamed

    2003-09-01

    Renal angiomyolipoma is a rare benign tumour, often associated with congenital diseases especially de Bourneville's tuberous sclerosis. Bilateral angiomyolipoma is exceptional. The authors report a case of bilateral renal angiomyolipoma in a 33-year-old patient presenting with haemorrhagic shock. In the light of this case and a review of the literature, the authors discuss the diagnostic and therapeutic aspects of this disease.

  16. FARMACOFISIOLOGÍA RENAL

    Directory of Open Access Journals (Sweden)

    Musso CG

    2014-03-01

    Full Text Available Renal physiology plays a key role in the pharmacokinetics of many drugs. Knowledge of the particularities of each nephron function (filtration, secretion, reabsorption and excretion and each of renal tubular transport mechanisms (simple diffusion, facilitated diffusion, facilitated transport, active transport, endocytosis and pinocytosis is fundamental to achieve better management of drug prescriptions.

  17. [CHRONIC RENAL FAILURE AND PREGNANCY--A CASE REPORT].

    Science.gov (United States)

    Amaliev, G M; Uchikova, E; Malinova, M

    2015-01-01

    Pregnancy in women with chronic renal failure is a complex therapeutic problem requiring a multidisciplinary approach. It is associated with a higher risk of many perinatal complications. The most common abnormalities are related to: progression of renal failure, development of preeclampsia development of nephrotic syndrome, anemic syndrome, IUGR and fetal death. The prognosis depends on the values of serum creatinine prior to pregnancy, the degree of deterioration of renal function, development of additional obstetric complications and the specific etiological reasons that have led to the occurrence of renal failure. Determining the optimum time for authorization birth depends on the condition of the mother, the condition of the fetus and the rate of progression of renal failure, and the deadline the pregnancy should be terminated is 35 weeks. We present a case of a patient with chronic renal failure, with favorable perinatal outcome.

  18. [Case of infective endocarditis diagnosed with renal infarction].

    Science.gov (United States)

    Nakayama, Takayuki; Yokoyama, Minato; Saito, Kazutaka; Takenaka, Shunsuke; Kubo, Yuichi; Iimura, Yasumasa; Numao, Noboru; Sakai, Yasuyuki; Koga, Fumitaka; Fujii, Yasuhisa; Kobayashi, Tsuyoshi; Kawakami, Satoru; Kihara, Kazunori

    2009-03-01

    A 46-year-old woman with sudden on set strong right flank pain was transferred to our hospital with the diagnosis of right renal infarction. Cardiac ultrasonography revealed a vegetation on the posterior cusp of the mitral valve, and the renal infarction was thought to be caused by renal artery embolism from infective endocarditis. Since the vegetation remained after antimicrobial therapy as conservative management, the patient was surgically treated by mitral annuloplasty. It has been known that infective endocarditis can cause renal infarction. Infective endocarditis requires immediate and adequate treatment because of high mortality. Therefore, the appropriate diagnosis of infective endocarditis is needed for patients with renal infarction without any other disorder causing renal infarction.

  19. Pathogenesis of Type 2 Epithelial to Mesenchymal Transition (EMT in Renal and Hepatic Fibrosis

    Directory of Open Access Journals (Sweden)

    Anusha H. Tennakoon

    2015-12-01

    Full Text Available Epithelial to mesenchymal transition (EMT, particularly, type 2 EMT, is important in progressive renal and hepatic fibrosis. In this process, incompletely regenerated renal epithelia lose their epithelial characteristics and gain migratory mesenchymal qualities as myofibroblasts. In hepatic fibrosis (importantly, cirrhosis, the process also occurs in injured hepatocytes and hepatic progenitor cells (HPCs, as well as ductular reaction-related bile epithelia. Interestingly, the ductular reaction contributes partly to hepatocarcinogenesis of HPCs, and further, regenerating cholangiocytes after injury may be derived from hepatic stellate cells via mesenchymal to epithelia transition, a reverse phenomenon of type 2 EMT. Possible pathogenesis of type 2 EMT and its differences between renal and hepatic fibrosis are reviewed based on our experimental data.

  20. Pathogenesis of Type 2 Epithelial to Mesenchymal Transition (EMT) in Renal and Hepatic Fibrosis

    Science.gov (United States)

    Tennakoon, Anusha H.; Izawa, Takeshi; Kuwamura, Mitsuru; Yamate, Jyoji

    2015-01-01

    Epithelial to mesenchymal transition (EMT), particularly, type 2 EMT, is important in progressive renal and hepatic fibrosis. In this process, incompletely regenerated renal epithelia lose their epithelial characteristics and gain migratory mesenchymal qualities as myofibroblasts. In hepatic fibrosis (importantly, cirrhosis), the process also occurs in injured hepatocytes and hepatic progenitor cells (HPCs), as well as ductular reaction-related bile epithelia. Interestingly, the ductular reaction contributes partly to hepatocarcinogenesis of HPCs, and further, regenerating cholangiocytes after injury may be derived from hepatic stellate cells via mesenchymal to epithelia transition, a reverse phenomenon of type 2 EMT. Possible pathogenesis of type 2 EMT and its differences between renal and hepatic fibrosis are reviewed based on our experimental data. PMID:26729181

  1. The role of exosomes in peripheral nerve regeneration

    Directory of Open Access Journals (Sweden)

    Rosanna C Ching

    2015-01-01

    Full Text Available Peripheral nerve injuries remain problematic to treat, with poor functional recovery commonly observed. Injuries resulting in a nerve gap create specific difficulties for axonal regeneration. Approaches to address these difficulties include autologous nerve grafts (which are currently the gold standard treatment and synthetic conduits, with the latter option being able to be impregnated with Schwann cells or stem cells which provide an appropriate micro-environment for neuronal regeneration to occur. Transplanting stem cells, however, infers additional risk of malignant transformation as well as manufacturing difficulties and ethical concerns, and the use of autologous nerve grafts and Schwann cells requires the sacrifice of a functioning nerve. A new approach utilizing exosomes, secreted extracellular vesicles, could avoid these complications. In this review, we summarize the current literature on exosomes, and suggest how they could help to improve axonal regeneration following peripheral nerve injury.

  2. Microfabricated Segmented-Involute-Foil Regenerator for Stirling Engines

    Science.gov (United States)

    Ibrahim, Mounir; Danila, Daniel; Simon, Terrence; Mantell, Susan; Sun, Liyong; Gedeon, David; Qiu, Songgang; Wood, Gary; Kelly, Kevin; McLean, Jeffrey

    2010-01-01

    An involute-foil regenerator was designed, microfabricated, and tested in an oscillating-flow test rig. The concept consists of stacked involute-foil nickel disks (see figure) microfabricated via a lithographic process. Test results yielded a performance of about twice that of the 90-percent random-fiber currently used in small Stirling converters. The segmented nature of the involute- foil in both the axial and radial directions increases the strength of the structure relative to wrapped foils. In addition, relative to random-fiber regenerators, the involute-foil has a reduced pressure drop, and is expected to be less susceptible to the release of metal fragments into the working space, thus increasing reliability. The prototype nickel involute-foil regenerator was adequate for testing in an engine with a 650 C hot-end temperature. This is lower than that required by larger engines, and high-temperature alloys are not suited for the lithographic microfabrication approach.

  3. The role of exosomes in peripheral nerve regeneration

    Institute of Scientific and Technical Information of China (English)

    Rosanna C Ching; Paul J Kingham

    2015-01-01

    Peripheral nerve injuries remain problematic to treat, with poor functional recovery commonly observed. Injuries resulting in a nerve gap create specific difficulties for axonal regeneration. Approaches to address these difficulties include autologous nerve grafts (which are currently the gold standard treatment) and synthetic conduits, with the latter option being able to be im-pregnated with Schwann cells or stem cells which provide an appropriate micro-environment for neuronal regeneration to occur. Transplanting stem cells, however, infers additional risk of malignant transformation as well as manufacturing dififculties and ethical concerns, and the use of autologous nerve grafts and Schwann cells requires the sacriifce of a functioning nerve. A new approach utilizing exosomes, secreted extracellular vesicles, could avoid these complications. In this review, we summarize the current literature on exosomes, and suggest how they could help to improve axonal regeneration following peripheral nerve injury.

  4. Use of electrospinning to construct biomaterials for peripheral nerve regeneration.

    Science.gov (United States)

    Quan, Qi; Chang, Biao; Meng, Hao Ye; Liu, Ruo Xi; Wang, Yu; Lu, Shi Bi; Peng, Jiang; Zhao, Qing

    2016-10-01

    A number of limitations associated with the use of hollow nerve guidance conduits (NGCs) require further discussion. Most importantly, the functional recovery outcomes after the placement of hollow NGCs are poor even after the successful bridging of peripheral nerve injuries. However, nerve regeneration scaffolds built using electric spinning have several advantages that may improve functional recovery. Thus, the present study summarizes recent developments in this area, including the key cells that are combined with the scaffold and associated with nerve regeneration, the structure and configuration of the electrospinning design (which determines the performance of the electrospinning scaffold), the materials the electrospinning fibers are composed of, and the methods used to control the morphology of a single fiber. Additionally, this study also discusses the processes underlying peripheral nerve regeneration. The primary goals of the present review were to evaluate and consolidate the findings of studies that used scaffolding biomaterials built by electrospinning used for peripheral nerve regeneration support. It is amazing that the field of peripheral nerve regeneration continues to consistently produce such a wide variety of innovative techniques and novel types of equipment, because the introduction of every new process creates an opportunity for advances in materials for nerve repair.

  5. An integrated view of asteroid regeneration: tissues, cells and molecules.

    Science.gov (United States)

    Ben Khadra, Yousra; Sugni, Michela; Ferrario, Cinzia; Bonasoro, Francesco; Varela Coelho, Ana; Martinez, Pedro; Candia Carnevali, Maria Daniela

    2017-03-22

    The potential for repairing and replacing cells, tissues, organs and body parts is considered a primitive attribute of life shared by all the organisms, even though it may be expressed to a different extent and which is essential for the survival of both individual and whole species. The ability to regenerate is particularly evident and widespread within invertebrates. In spite of the wide availability of experimental models, regeneration has been comprehensively explored in only a few animal systems (i.e., hydrozoans, planarians, urodeles) leaving many other animal groups unexplored. The regenerative potential finds its maximum expression in echinoderms. Among echinoderm classes, asteroids offer an impressive range of experimental models in which to study arm regeneration at different levels. Many studies have been recently carried out in order to understand the regenerative mechanisms in asteroids and the overall morphological processes have been well documented in different starfish species, such as Asterias rubens, Leptasterias hexactis and Echinaster sepositus. In contrast, very little is known about the molecular mechanisms that control regeneration development and patterning in these models. The origin and the fate of cells involved in the regenerative process remain a matter of debate and clear insights will require the use of complementary molecular and proteomic approaches to study this problem. Here, we review the current knowledge regarding the cellular, proteomic and molecular aspects of asteroid regeneration.

  6. Regenerator cross arm seal assembly

    Science.gov (United States)

    Jackman, Anthony V.

    1988-01-01

    A seal assembly for disposition between a cross arm on a gas turbine engine block and a regenerator disc, the seal assembly including a platform coextensive with the cross arm, a seal and wear layer sealingly and slidingly engaging the regenerator disc, a porous and compliant support layer between the platform and the seal and wear layer porous enough to permit flow of cooling air therethrough and compliant to accommodate relative thermal growth and distortion, a dike between the seal and wear layer and the platform for preventing cross flow through the support layer between engine exhaust and pressurized air passages, and air diversion passages for directing unregenerated pressurized air through the support layer to cool the seal and wear layer and then back into the flow of regenerated pressurized air.

  7. Muscle regeneration in mitochondrial myopathies

    DEFF Research Database (Denmark)

    Krag, T O; Hauerslev, S; Jeppesen, T D

    2013-01-01

    Mitochondrial myopathies cover a diverse group of disorders in which ragged red and COX-negative fibers are common findings on muscle morphology. In contrast, muscle degeneration and regeneration, typically found in muscular dystrophies, are not considered characteristic features of mitochondrial...... myopathies. We investigated regeneration in muscle biopsies from 61 genetically well-defined patients affected by mitochondrial myopathy. Our results show that the perturbed energy metabolism in mitochondrial myopathies causes ongoing muscle regeneration in a majority of patients, and some were even affected...... by a dystrophic morphology. The results add to the complexity of the pathogenesis underlying mitochondrial myopathies, and expand the knowledge about the impact of energy deficiency on another aspect of muscle structure and function....

  8. Some principles of regeneration in mammalian systems.

    Science.gov (United States)

    Carlson, Bruce M

    2005-11-01

    This article presents some general principles underlying regenerative phenomena in vertebrates, starting with the epimorphic regeneration of the amphibian limb and continuing with tissue and organ regeneration in mammals. Epimorphic regeneration following limb amputation involves wound healing, followed shortly by a phase of dedifferentiation that leads to the formation of a regeneration blastema. Up to the point of blastema formation, dedifferentiation is guided by unique regenerative pathways, but the overall developmental controls underlying limb formation from the blastema generally recapitulate those of embryonic limb development. Damaged mammalian tissues do not form a blastema. At the cellular level, differentiation follows a pattern close to that seen in the embryo, but at the level of the tissue and organ, regeneration is strongly influenced by conditions inherent in the local environment. In some mammalian systems, such as the liver, parenchymal cells contribute progeny to the regenerate. In others, e.g., skeletal muscle and bone, tissue-specific progenitor cells constitute the main source of regenerating cells. The substrate on which regeneration occurs plays a very important role in determining the course of regeneration. Epimorphic regeneration usually produces an exact replica of the structure that was lost, but in mammalian tissue regeneration the form of the regenerate is largely determined by the mechanical environment acting on the regenerating tissue, and it is normally an imperfect replica of the original. In organ hypertophy, such as that occurring after hepatic resection, the remaining liver mass enlarges, but there is no attempt to restore the original form.

  9. Primary renal hydatidosis

    Directory of Open Access Journals (Sweden)

    Johnsy Merla Joel

    2016-01-01

    Full Text Available Echinococcosis or hydatidosis caused by the tapeworm, Echinococcus granulosus, has the highest prevalence in endemic regions and sheep farming areas. The most common organ involved is the liver (50–75% followed by the lungs (15–20% and other organs (10–20%. Primary involvement of the kidney without the involvement of the liver and lungs, i.e., isolated renal hydatid disease is extremely rare even in endemic areas. The incidence of renal echinococcosis is 2–4%. Renal hydatid cysts usually remain asymptomatic for many years and are multiloculated. A 63-year-old male presented with left loin pain. Computed tomography scan abdomen revealed a presumptive diagnosis of renal hydatid disease. The nephrectomy specimen received in histopathology confirmed the diagnosis. We describe a rare case of primary renal hydatidosis.

  10. Involvement of the Hippo pathway in regeneration and fibrogenesis after ischaemic acute kidney injury: YAP is the key effector.

    Science.gov (United States)

    Xu, Jing; Li, Pei-Xue; Wu, Jun; Gao, Yi-Jun; Yin, Meng-Xin; Lin, Ye; Yang, Ming; Chen, Dong-Ping; Sun, Hai-Peng; Liu, Zeng-Bo; Gu, Xiang-Chen; Huang, Hong-Ling; Fu, Li-Li; Hu, Hui-Min; He, Liang-Liang; Wu, Wen-Qing; Fei, Zhao-Liang; Ji, Hong-Bin; Zhang, Lei; Mei, Chang-Lin

    2016-03-01

    Renal tubule cells can recover after they undergo AKI (acute kidney injury). An incomplete repair of renal tubules can result in progressive fibrotic CKD (chronic kidney disease). Studies have revealed the relationship between tubular epithelial cells and kidney fibrogenesis. However, the underlying mechanism remains unclear. Hippo pathway components were evaluated in complete/incomplete repair of I/R (ischaemia/reperfusion) AKI rat models, HK-2 cells and AKI human renal biopsy samples. We found that the expression levels of the Hippo pathway components changed dynamically during kidney regeneration and fibrogenesis in rat models of I/R-induced AKI and human renal biopsy samples. The transcription cofactor YAP (Yes-associated protein) might be a key effector of renal regeneration and fibrogenesis. Our results showed further that YAP might elicit both beneficial and detrimental effects on I/R AKI. After I/R injury occurred, YAP could promote the repair of the injured epithelia. The constant YAP increase and activation might be related to interstitial fibrosis and abnormal renal tubule differentiation. These results indicate that the proper modulation of the Hippo pathway, specifically the transcription cofactor YAP, during repair might be a potent therapeutic target in AKI-CKD transition after I/R injury.

  11. Fenestration defects in the rabbit jaw: an inadequate model for studying periodontal regeneration.

    NARCIS (Netherlands)

    Oortgiesen, D.A.W.; Meijer, G.J.; Bronckers, A.L.; Walboomers, X.F.; Jansen, J.A.

    2010-01-01

    Periodontitis is an inflammatory disease affecting the support of the teeth, eventually leading to loosening and subsequent loss of teeth. Effective procedures for periodontal tissue engineering or regeneration require preclinical models before market introduction. Research has been performed in eit

  12. Fenestration defects in the rabbit jaw: an inadequate model for studying periodontal regeneration

    NARCIS (Netherlands)

    Oortgiesen, D.A.W.; Meijer, G.J.; Bronckers, A.L.J.J.; Walboomers, X.F.; Jansen, J.A.

    2010-01-01

    Periodontitis is an inflammatory disease affecting the support of the teeth, eventually leading to loosening and subsequent loss of teeth. Effective procedures for periodontal tissue engineering or regeneration require preclinical models before market introduction. Research has been performed in eit

  13. Regenerable Trace-Contaminant Sorbent for the Primary Life Support System (PLSS) Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The NASA objective of expanding the human experience into the far reaches of space requires the development of regenerable life support systems. This proposal...

  14. Statins and progressive renal disease.

    Science.gov (United States)

    Buemi, Michele; Senatore, Massimino; Corica, Francesco; Aloisi, Carmela; Romeo, Adolfo; Cavallaro, Emanuela; Floccari, Fulvio; Tramontana, Domenico; Frisina, Nicola

    2002-01-01

    Thanks to the administration of hypocholesterolemic drugs, important advances have been made in the treatment of patients with progressive renal disease. In vitro and in vivo findings demonstrate that statins, the inhibitors of HMG-CoA reductase, can provide protection against kidney diseases characterized by inflammation and/or enhanced proliferation of epithelial cells occurring in rapidly progressive glomerulonephritis, or by increased proliferation of mesangial cells occurring in IgA nephropathy. Many of the beneficial effects obtained occur independent of reduced cholesterol levels because statins can directly inhibit the proliferation of different cell types (e.g., mesangial, renal tubular, and vascular smooth muscle cells), and can also modulate the inflammatory response, thus inhibiting macrophage recruitment and activation, as well as fibrosis. The mechanisms underlying the action of statins are not yet well understood, although recent data in the literature indicate that they can directly affect the proliferation/apoptosis balance, the down-regulation of inflammatory chemokines, and the cytogenic messages mediated by the GTPases Ras superfamily. Therefore, as well as reducing serum lipids, statins and other lipid-lowering agents may directly influence intracellular signaling pathways involved in the prenylation of low molecular weight proteins that play a crucial role in cell signal transduction and cell activation. Statins appear to have important potential in the treatment of progressive renal disease, although further studies are required to confirm this in humans.

  15. Development of regenerable sorbents for the Copper Oxide Bed Regenerable Absorber (COBRA) process

    Energy Technology Data Exchange (ETDEWEB)

    Abbasian, J.; Slimane, R.B. [Inst. of Gas Technology, Des Plaines, IL (United States); Carty, R.H. [Illinois Clean Coal Inst., Carterville, IL (United States)

    1999-07-01

    In the clean air act amendments (CAAA) of 1990, legislation was introduced requiring electric utilities to adopt available technology for removal of pollutant gases (mainly SO{sub 2} and NO{sub x}) and particulates from coal combustion flue gases so that the increased use of coal is done in an environmentally acceptable manner. The copper oxide process has been selected as one of the most promising emerging technologies for SO{sub 2} and NO{sub x} removal from flue gases in the Combustion 2000 program of the U.S. Department of Energy. In particular, the development of the Copper Oxide Bed Regenerable Absorber (COBRA) process, which is based on moving-bed cross-flow reactor design for the combined removal of SO{sub 2}, NO{sub x}, and particulates, has been pursued in conjunction with the use of Illinois coal. This ongoing study has been directed towards the evaluation of the ALCOA copper oxide sorbent currently being utilized in the demonstration of the COBRA process, to identify areas of improvement, and to develop and implement a strategy for preparing improved sorbents. The targeted areas of sorbent improvement include higher reactivity, higher theoretical sulfur capacity, lower regeneration temperature, and better attrition resistance. In this paper, the results obtained to-date from tests carried out for the evaluation of the commercial sorbent for SO2 removal from simulated flue gases, its regenerability, and its effectiveness with repeated use are presented and discussed. (orig.)

  16. Neuro-endovascular Embolic Agent for Treatment of a Renal Arteriovenous Fistula

    Directory of Open Access Journals (Sweden)

    Gurpreet Singh

    2016-01-01

    Full Text Available Renal arteriovenous fistula is a known complication following a renal biopsy, and may require catheter based embolization. Distal location of these fistulas in the renal parenchyma in many a case may necessitate non-traditional embolic materials. Liquid embolic agents that allow a controlled delivery may be suitable in this situation, as demonstrated in this case report.

  17. Renal replacement therapy after cardiac surgery; renal function recovers

    DEFF Research Database (Denmark)

    Steinthorsdottir, Kristin Julia; Kandler, Kristian; Agerlin Windeløv, Nis

    2013-01-01

    To assess renal outcome in patients discharged from hospital following cardiac surgery-associated acute kidney injury (CSA-AKI) with need for renal replacement therapy.......To assess renal outcome in patients discharged from hospital following cardiac surgery-associated acute kidney injury (CSA-AKI) with need for renal replacement therapy....

  18. Gene expression following induction of regeneration in Drosophila wing imaginal discs. Expression profile of regenerating wing discs

    Directory of Open Access Journals (Sweden)

    Blanco Enrique

    2010-09-01

    Full Text Available Abstract Background Regeneration is the ability of an organism to rebuild a body part that has been damaged or amputated, and can be studied at the molecular level using model organisms. Drosophila imaginal discs, which are the larval primordia of adult cuticular structures, are capable of undergoing regenerative growth after transplantation and in vivo culture into the adult abdomen. Results Using expression profile analyses, we studied the regenerative behaviour of wing discs at 0, 24 and 72 hours after fragmentation and implantation into adult females. Based on expression level, we generated a catalogue of genes with putative role in wing disc regeneration, identifying four classes: 1 genes with differential expression within the first 24 hours; 2 genes with differential expression between 24 and 72 hours; 3 genes that changed significantly in expression levels between the two time periods; 4 genes with a sustained increase or decrease in their expression levels throughout regeneration. Among these genes, we identified members of the JNK and Notch signalling pathways and chromatin regulators. Through computational analysis, we recognized putative binding sites for transcription factors downstream of these pathways that are conserved in multiple Drosophilids, indicating a potential relationship between members of the different gene classes. Experimental data from genetic mutants provide evidence of a requirement of selected genes in wing disc regeneration. Conclusions We have been able to distinguish various classes of genes involved in early and late steps of the regeneration process. Our data suggests the integration of signalling pathways in the promoters of regulated genes.

  19. Study report on tissue organ regeneration and replication in situ%组织器官的原位再生复制研究报告

    Institute of Scientific and Technical Information of China (English)

    徐荣祥

    2003-01-01

    果对人类生命科学的一大贡献.%In this report ,we mainly covered the following aspects of "Tissue organ regeneration and replication in situ":1)Procedures of tissue organd regeneration and replication and replication in clnical practice;2)The discover and existence of Potentiald Regenerative Cell(PRC);3)The proliferation ,differentiation and regeneration law of Potential law of Potential Regenerative Cells;4)Study procedure on tissue organ regeneration and replication from PRCs in vitro based on the model of full skin organ regeneration in situ after extensive in vitro,set up the method and technology of searching life regenerative substance required in tissue organ regeneration and replication in situ.In this study,first ,the whole human body is divided into 206 function units,which are the "Tissue Organ"in regeneration study.Then the histology foundation of tissue organ regeneration and replication in situ is set up.In ordre to prove the existence of the Potential Regenerative Cells and their potential baility and function ,we established clinical tracking rechnique of skin organ regeneration in situ;meanwhile,several tissue organ regeneration and replication in vitro models which represent different kinds of runctions were sucessfully set up,With all these techniques and models ,we confirmed:1)the existence ,function and ability of Pptemtoa Regenerative Cells;2)the importance of life regenerative substance;3)the feasibility of tissue organ regeneration and replication in situ;4)the big value of tissue organ regeneration and replication in situ in life science and medicine progerss.We also showed the possible foreground of capture cancer with this method and technologh.In this report,nearly 200 photographs of several tissue organ regeneration and replication in situ or in vitro demonstrated the whole process of tissue organ and big organ entities regeneration and replication from cells .The results of tissue organ regeneration and replication in situ

  20. Assessment of compensatory renal function and [125I]iothalamate clearance in sheep.

    Science.gov (United States)

    Filippich, L J; English, P B; Ainscow, J

    1985-11-01

    Compensatory renal function and sodium [125I]iothalamate clearance were studied in 4 adult Merino ewes. Renal clearances of inulin (CIN), iothalamate (CIOT), and p-aminohippurate (CPAH) were used to measure renal function before and 7 and 170 days after 50% and 75% reductions in renal mass. Renal mass reduction to 50% of normal was achieved by ligation of the right renal artery, and to 25% of normal by ligating the right renal artery and branches of the left renal artery. Renal function (CIN and CPAH) after 50% renal mass reduction was 78% of normal on postligation day (PLD) 7 and 64% of normal on PLD 170. This decrease in renal function between PLD 7 and 170 was significant (P less than 0.05). Renal function (CIN and CPAH) after 75% renal mass reduction was 55% of normal on PLD 7 and 48% on PLD 170; however, this decrease in renal function between PLD 7 and 170 was not significant. Results indicated that, shortly after 50% renal mass reduction by renal arterial ligation, renal function in ewes was greater than that previously reported after unilateral nephrectomy and that a further decrease in renal function developed within 6 months after ligation. The mean CIOT in healthy ewes was 2.46 ml/min/kg of body weight. In healthy ewes and in ewes after renal mass reduction, regression of the simultaneous CIOT and CIN was CIOT = 0.276 + 1.05 CIN. The CIOT was higher than the corresponding CIN, and remained significantly (P less than 0.01) and consistently higher. Therefore, iothalamate can be used to estimate glomerular filtration rate in sheep, although a correction factor is required.

  1. Temporal regulation of planarian eye regeneration

    OpenAIRE

    Deochand, Michelle E.; Birkholz, Taylor R.; Wendy S Beane

    2016-01-01

    Abstract While tissue regeneration is typically studied using standard injury models, in nature injuries vary greatly in the amount and location of tissues lost. Planarians have the unique ability to regenerate from many different injuries (including from tiny fragments with no brain), allowing us to study the effects of different injuries on regeneration timelines. We followed the timing of regeneration for one organ, the eye, after multiple injury types that involved tissue loss (single‐ an...

  2. Stem cell technology for tendon regeneration: current status, challenges, and future research directions

    OpenAIRE

    2015-01-01

    Pauline Po Yee Lui Headquarter, Hospital Authority, Hong Kong SAR, People's Republic of China Abstract: Tendon injuries are a common cause of physical disability. They present a clinical challenge to orthopedic surgeons because injured tendons respond poorly to current treatments without tissue regeneration and the time required for rehabilitation is long. New treatment options are required. Stem cell-based therapies offer great potential to promote tendon regeneration due to their h...

  3. Group C. Initiator paper. Periodontal regeneration--fact or fiction?

    Science.gov (United States)

    Bartold, P M

    2015-01-01

    Numerous techniques have been tried and tested to regenerate tissues lost to periodontal disease. While there has been some success to date, more work is required to move this to a reliable and clinically predictable procedure. Much of the future success for such treatments will rely largely on our understanding of the biology of both developmental and regenerative processes. Nonetheless, despite the noble goal of periodontal regeneration, the relevance of re-creation of a connective tissue attachment has been questioned. Since formation of a long junctional epithelial attachment to the tooth following a variety of periodontal treatment procedures has been shown to be no more susceptible to further breakdown than a non-diseased site, the question arises as to what purpose do we seek the ultimate outcome of periodontal regeneration? The answer lies in the "fact and fiction" of periodontal regeneration. There is no doubt that the regenerative procedures that have been developed can be shown to be biologically successful at the histological level. Furthermore, the results of periodontal regeneration (particularly guided tissue regeneration) have been stable over the long term (at least up to 10 years). However, the techniques currently under use which show the greatest promise (guided tissue regeneration and growth factors) are still clinically unpredictable because of their highly technique-sensitive nature. In addition, whether the slight clinical improvements offered by these procedures over routine open flap debridement procedures are of cost or patient benefit with regards to improved periodontal health and retention of teeth remains to be established. The next phase in regenerative technologies will undoubtedly involve a deeper understanding of the molecular signaling (both intra- and extra-cellular) and cellular differentiation processes involved in the regenerative processes. So in answer to the question of whether periodontal regeneration is fact or fiction

  4. Impaired Renal Function

    Directory of Open Access Journals (Sweden)

    Kentaro Ide

    2011-01-01

    Full Text Available Patients requiring liver transplantation (LT frequently experience renal insufficiency (RI, which affects their survival. Although calcineurin inhibitor-sparing immunosuppressive regimens (CSRs are well known to prevent RI, the immune state in recipients receiving CSR remains to be intensively investigated. Among 60 cases of living-donor LT at our institute, 68% of the patients had none to mild RI (non-RI group and 32% of the patients had moderate to severe RI (RI group. The RI group received a CSR comprising reduced dose of tacrolimus, methylprednisolone, and mycophenolate mofetil, while the non-RI group received a regimen comprising conventional dose of tacrolimus and methylprednisolone. One year after LT, the mean estimated glomerular filtration rate (eGFR in the RI group had significantly improved, although it was still lower than that of the non-RI group. Serial mixed lymphocyte reaction assays revealed that antidonor T-cell responses were adequately suppressed in both groups. Thus, we provide evidence that CSR leads to improvement of eGFR after LT in patients with RI, while maintaining an appropriate immunosuppressive state.

  5. Pregnancy and renal transplantation.

    Science.gov (United States)

    Başaran, O; Emiroğlu, R; Seçme, S; Moray, G; Haberal, M

    2004-01-01

    Ovarian dysfunction, anovulatory vaginal bleeding, amenorrhea, high prolactin levels, and loss of libido are the causes of infertility in women with chronic renal failure. After renal transplantation, endocrine function generally improves after recovery of renal function. In this study we retrospectively evaluated the prepregnancy and postdelivery renal function, outcome of gestation, as well as maternal and fetal complications for eight pregnancies in eight renal transplant recipients between November 1975 and March 2003 of 1095 among 1425. Eight planned pregnancies occurred at a mean of 3.6 years posttransplant. Spontaneous abortion occured in the first trimester in one case. One intrauterine growth retardation was observed with a full-term pregnancy; one intrauterine growth retardation and preterm delivery; one preeclampsia with preterm delivery and urinary tract infection; and one preeclampsia with preterm delivery and oligohydramnios. The mean gestation period was 35.5 +/- 3.0 weeks (31.2 to 38.0). Pregnancy had no negative impact on renal function during a 2-year follow-up. No significant proteinuria or acute rejection episodes were observed. Among the seven deliveries, no congenital anomaly was documented and no postpartum problems for the child and the mother were observed. Our study suggests that successful pregnancy is possible in renal transplant recipients. In cases with good graft function and absence of severe proteinuria or hypertension, pregnancy does not affect graft function or patient survival; however, fetal problems are encountered such as intrauterine growth retardation, low birth weight, and preeclampsia.

  6. Renal autotransplantation: current perspectives.

    Science.gov (United States)

    Stewart, B H; Banowsky, L H; Hewitt, C B; Straffon, R A

    1976-01-01

    Autotransplantation, with or without an extracorporeal renal operation, has been done 39 times in 37 patients. Indications for the procedure included severe ureteral injury in 4 patients, failed supravesical diversion in 2, renal carcinoma in a solitary kidney in 1, renovascular hypertension in 1 and donor arterial reconstruction before renal transplantation in 29. Success was obtained in all but 2 procedures, both of which involved previously operated kidneys with severe inflammation and adhesions involving the renal pelvis and pedicle. Based on our experience and a review of currently available literature we believe that renal autotransplantation and extracorporeal reconstruction can provide the best solution for patients with severe renovascular and ureteral disease not correctable by conventional operative techniques. The technique can be of particular value in removing centrally located tumors in solitary kidneys and in preparing donor kidneys with abnormal arteries for renal transplantation. The role of autotransplantation in the management of advanced renal trauma and calculus disease is less clear. A long-term comparison of patients treated by extracorporeal nephrolithotomy versus conventional lithotomy techniques will be necessary before a conclusion is reached in these disease categories.

  7. Discarded human kidneys as a source of ECM scaffold for kidney regeneration technologies.

    Science.gov (United States)

    Orlando, Giuseppe; Booth, Christopher; Wang, Zhan; Totonelli, Giorgia; Ross, Christina L; Moran, Emma; Salvatori, Marcus; Maghsoudlou, Panagiotis; Turmaine, Mark; Delario, Ginger; Al-Shraideh, Yousef; Farooq, Umar; Farney, Alan C; Rogers, Jeffrey; Iskandar, Samy S; Burns, Alan; Marini, Frank C; De Coppi, Paolo; Stratta, Robert J; Soker, Shay

    2013-08-01

    In the United States, more than 2600 kidneys are discarded annually, from the total number of kidneys procured for transplant. We hypothesized that this organ pool may be used as a platform for renal bioengineering and regeneration research. We previously showed that decellularization of porcine kidneys yields renal extracellular matrix (ECM) scaffolds that maintain their basic components, support cell growth and welfare in vitro and in vivo, and show an intact vasculature that, when such scaffolds are implanted in vivo, is able to sustain physiological blood pressure. The purpose of the current study was to test if the same strategy can be applied to discarded human kidneys in order to obtain human renal ECM scaffolds. The results show that the sodium dodecylsulfate-based decellularization protocol completely cleared the cellular compartment in these kidneys, while the innate ECM framework retained its architecture and biochemical properties. Samples of human renal ECM scaffolds stimulated angiogenesis in a chick chorioallantoic membrane assay. Importantly, the innate vascular network in the human renal ECM scaffolds retained its compliance. Collectively, these results indicate that discarded human kidneys are a suitable source of renal scaffolds and their use for tissue engineering applications may be more clinically applicable than kidneys derived from animals.

  8. Semiconductor devices for all-optical regeneration

    DEFF Research Database (Denmark)

    Öhman, Filip; Bischoff, Svend; Tromborg, Bjarne

    2003-01-01

    We review different implementations of semiconductor devices for all-optical regeneration. A general model will be presented for all-optical regeneration in fiber links, taking into consideration the trade-off between non-linearity and noise. Furthermore we discuss a novel regenerator type, based...

  9. Deer antler regeneration: cells, concepts, and controversies.

    Science.gov (United States)

    Kierdorf, Uwe; Kierdorf, Horst; Szuwart, Thomas

    2007-08-01

    The periodic replacement of antlers is an exceptional regenerative process in mammals, which in general are unable to regenerate complete body appendages. Antler regeneration has traditionally been viewed as an epimorphic process closely resembling limb regeneration in urodele amphibians, and the terminology of the latter process has also been applied to antler regeneration. More recent studies, however, showed that, unlike urodele limb regeneration, antler regeneration does not involve cell dedifferentiation and the formation of a blastema from these dedifferentiated cells. Rather, these studies suggest that antler regeneration is a stem-cell-based process that depends on the periodic activation of, presumably neural-crest-derived, periosteal stem cells of the distal pedicle. The evidence for this hypothesis is reviewed and as a result, a new concept of antler regeneration as a process of stem-cell-based epimorphic regeneration is proposed that does not involve cell dedifferentiation or transdifferentiation. Antler regeneration illustrates that extensive appendage regeneration in a postnatal mammal can be achieved by a developmental process that differs in several fundamental aspects from limb regeneration in urodeles.

  10. All optical regeneration using semiconductor devices

    DEFF Research Database (Denmark)

    Mørk, Jesper; Öhman, Filip; Tromborg, Bjarne

    All-optical regeneration is a key functionality for implementing all-optical networks. We present a simple theory for the bit-error-rate in links employing all-optical regenerators, which elucidates the interplay between the noise and and nonlinearity of the regenerator. A novel device structure ...... is analyzed, emphasizing general aspects of active semiconductor waveguides....

  11. Two cases of cisplatin-induced permanent renal failure following neoadjuvant chemotherapy for esophageal cancer

    OpenAIRE

    Tomohiko Sasaki; Satoru Motoyama; Atsushi Komatsuda; Hiroyuki Shibata; Yusuke Sato; Kei Yoshino; Akiyuki Wakita; Hajime Saito; Akira Anbai; Mario Jin; Yoshihiro Minamiya

    2016-01-01

    Introduction: We experienced two esophageal cancer patients who developed severe acute renal failure after neoadjuvant chemotherapy with cisplatin and 5-fluorourasil. Presentation of case: After administration of cisplatin, their serum creatinine increased gradually until they required hemodialysis and their renal failure was permanent. In both cases, renal biopsy examination indicated partial recovery of the proximal tubule, but renal function did not recover. After these events, one pati...

  12. Practical uses of a quantitative renal scintillation camera study. [/sup 131/I tracer techniques

    Energy Technology Data Exchange (ETDEWEB)

    Bueschen, A.J.; Lloyd, L.K.

    1976-10-01

    A quantitative renal scintillation camera study has been described for the evaluation of total renal function and the split function of the two kidneys by a noninvasive technic. It requires no patient preparation, is not affected by bowel gas, and no allergic reactions have been reported. Six cases are reported to illustrate its usefulness with renal tumors, neurogenic bladders, pyelonephritis, nephrolithiasis, congenital anomalies, and renal insufficiency.

  13. Midterm renal functions following acute renal infarction

    Directory of Open Access Journals (Sweden)

    Sakir Ongun

    2015-10-01

    Full Text Available The aim of this study was to explore clinical features of renal infarction (RI that may have a role in diagnosis and treatment in our patient cohort and provide data on midterm renal functions. Medical records of patients with diagnosis of acute RI, established by contrast enhanced computed tomography (CT and at least 1 year follow-up data, who were hospitalized in our clinic between 1998 and 2012 were retrospectively reviewed; including descriptive data, clinical signs and symptoms, etiologic factors, laboratory findings, and prescribed treatments. Patients with solitary infarct were treated with acetylsalicylic acid (ASA only, whereas patients with atrial fibrillation (AF or multiple or global infarct were treated with anticoagulants. Estimated Glomerular Filtration Rate (eGFR referring to renal functions was determined by the Modification of Diet in Renal Disease (MDRD formula. Twenty-seven renal units of 23 patients with acute RI were identified. The mean age was 59.7 ± 15.7 years. Fourteen patients (60.8% with RI had atrial fibrillation (AF as an etiologic factor of which four had concomitant mesenteric ischemia at diagnosis. At presentation, 20 patients (86.9% had elevated serum lactate dehydrogenase (LDH, 18 patients (78.2% had leukocytosis, and 16 patients (69.5% had microscopic hematuria. Two patients with concomitant mesenteric ischemia and AF passed away during follow up. Mean eGFR was 70.8 ± 23.2 mL/min/1.73 m2 at admission and increased to 82.3 ± 23.4 mL/min/1.73 m2 at 1 year follow up. RI should be considered in patients with persistent flank or abdominal pain, particularly if they are at high risk of thromboembolism. Antiplatelet and/or anticoagulant drugs are both effective treatment options according to the amplitude of the infarct for preserving kidney functions.

  14. Midterm renal functions following acute renal infarction.

    Science.gov (United States)

    Ongun, Sakir; Bozkurt, Ozan; Demir, Omer; Cimen, Sertac; Aslan, Guven

    2015-10-01

    The aim of this study was to explore clinical features of renal infarction (RI) that may have a role in diagnosis and treatment in our patient cohort and provide data on midterm renal functions. Medical records of patients with diagnosis of acute RI, established by contrast enhanced computed tomography (CT) and at least 1 year follow-up data, who were hospitalized in our clinic between 1998 and 2012 were retrospectively reviewed; including descriptive data, clinical signs and symptoms, etiologic factors, laboratory findings, and prescribed treatments. Patients with solitary infarct were treated with acetylsalicylic acid (ASA) only, whereas patients with atrial fibrillation (AF) or multiple or global infarct were treated with anticoagulants. Estimated Glomerular Filtration Rate (eGFR) referring to renal functions was determined by the Modification of Diet in Renal Disease (MDRD) formula. Twenty-seven renal units of 23 patients with acute RI were identified. The mean age was 59.7 ± 15.7 years. Fourteen patients (60.8%) with RI had atrial fibrillation (AF) as an etiologic factor of which four had concomitant mesenteric ischemia at diagnosis. At presentation, 20 patients (86.9%) had elevated serum lactate dehydrogenase (LDH), 18 patients (78.2%) had leukocytosis, and 16 patients (69.5%) had microscopic hematuria. Two patients with concomitant mesenteric ischemia and AF passed away during follow up. Mean eGFR was 70.8 ± 23.2 mL/min/1.73 m(2) at admission and increased to 82.3 ± 23.4 mL/min/1.73 m(2) at 1 year follow up. RI should be considered in patients with persistent flank or abdominal pain, particularly if they are at high risk of thromboembolism. Antiplatelet and/or anticoagulant drugs are both effective treatment options according to the amplitude of the infarct for preserving kidney functions.

  15. DECOLORIZATION AND CHEMICAL REGENERATION OF ...

    African Journals Online (AJOL)

    Preferred Customer

    Citric acid is an important chemical product which wildly used in the food and ... activated carbon (PAC) decoloring process is batch operation and has to be filtered to .... adsorbates adsorbed from solution per unit weight of regenerated GAC at the ..... Achaerandio, I.; Guell, C.; Lopez, F. J. Food Engineering 2002, 51, 311. 9.

  16. Skeletal muscle development and regeneration.

    NARCIS (Netherlands)

    Grefte, S.; Kuijpers-Jagtman, A.M.; Torensma, R.; Hoff, J.W. Von den

    2007-01-01

    In the late stages of muscle development, a unique cell population emerges that is a key player in postnatal muscle growth and muscle regeneration. The location of these cells next to the muscle fibers triggers their designation as satellite cells. During the healing of injured muscle tissue, satell

  17. MECHANICAL REGENERATION OF SAND WASTE

    Directory of Open Access Journals (Sweden)

    D. I. Gnir

    2005-01-01

    Full Text Available The experimental activation of the sand regenerator of the firm SINTO is carried out at ОАО “MZOO". It is shown that sand grains are cleared from films of binding agents, that allows to use the treated sand for preparation of agglutinant and core sands.

  18. Bone regeneration during distraction osteogenesis

    NARCIS (Netherlands)

    Amir, L.R.; Everts, V.; Bronckers, A.L.J.J.

    2009-01-01

    Bone has the capacity to regenerate in response to injury. During distraction osteogenesis, the renewal of bone is enhanced by gradual stretching of the soft connec- tive tissues in the gap area between two separated bone segments. This procedure has received much clinical atten- tion as a way to co

  19. Skeletal muscle development and regeneration.

    NARCIS (Netherlands)

    Grefte, S.; Kuijpers-Jagtman, A.M.; Torensma, R.; Hoff, J.W. Von den

    2007-01-01

    In the late stages of muscle development, a unique cell population emerges that is a key player in postnatal muscle growth and muscle regeneration. The location of these cells next to the muscle fibers triggers their designation as satellite cells. During the healing of injured muscle tissue,

  20. Mechanical device for tissue regeneration

    NARCIS (Netherlands)

    Herder, J.L.; Maij, E.

    2010-01-01

    The invention relates to a mechanical device for tissue- regeneration inside a patient, comprising means (2, 3) to place a scaffold for the tissue under mechanical stress. Said means comprise a first device-part (2) and a second device-part (3) which parts are arranged to be movable with respect to

  1. Live Imaging of Axolotl Digit Regeneration Reveals Spatiotemporal Choreography of Diverse Connective Tissue Progenitor Pools.

    Science.gov (United States)

    Currie, Joshua D; Kawaguchi, Akane; Traspas, Ricardo Moreno; Schuez, Maritta; Chara, Osvaldo; Tanaka, Elly M

    2016-11-21

    Connective tissues-skeleton, dermis, pericytes, fascia-are a key cell source for regenerating the patterned skeleton during axolotl appendage regeneration. This complexity has made it difficult to identify the cells that regenerate skeletal tissue. Inability to identify these cells has impeded a mechanistic understanding of blastema formation. By tracing cells during digit tip regeneration using brainbow transgenic axolotls, we show that cells from each connective tissue compartment have distinct spatial and temporal profiles of proliferation, migration, and differentiation. Chondrocytes proliferate but do not migrate into the regenerate. In contrast, pericytes proliferate, then migrate into the blastema and give rise solely to pericytes. Periskeletal cells and fibroblasts contribute the bulk of digit blastema cells and acquire diverse fates according to successive waves of migration that choreograph their proximal-distal and tissue contributions. We further show that platelet-derived growth factor signaling is a potent inducer of fibroblast migration, which is required to form the blastema.

  2. Gene-enhanced tissue engineering for dental hard tissue regeneration: (1 overview and practical considerations

    Directory of Open Access Journals (Sweden)

    Mason James M

    2006-05-01

    Full Text Available Abstract Gene-based therapies for tissue regeneration involve delivering a specific gene to a target tissue with the goal of changing the phenotype or protein expression profile of the recipient cell; the ultimate goal being to form specific tissues required for regeneration. One of the principal advantages of this approach is that it provides for a sustained delivery of physiologic levels of the growth factor of interest. This manuscript will review the principals of gene-enhanced tissue engineering and the techniques of introducing DNA into cells. Part 2 will review recent advances in gene-based therapies for dental hard tissue regeneration, specifically as it pertains to dentin regeneration/pulp capping and periodontal regeneration.

  3. Lactulose and renal failure.

    Science.gov (United States)

    Vogt, B; Frey, F J

    1997-01-01

    The introduction of lactulose as a new therapeutic agent for treatment of hepatic encephalopathy was a major breakthrough in this field. It was hypothesized that lactulose might prevent postoperative renal impairment after biliary surgery in patients with obstructive jaundice. The presumable mechanism purported was the diminished endotoxinemia by lactulose. Unfortunately, such a reno-protective effect has not been shown conclusively until now in clinical studies. In chronic renal failure lactulose is known to promote fecal excretion of water, sodium, potassium, amonium, urea, creatinine and protons. Thus, lactulose could be useful for the treatment of chronic renal failure. However, compliance to the therapy represents a major problem.

  4. Renal scintigraphy in veterinary medicine.

    Science.gov (United States)

    Tyson, Reid; Daniel, Gregory B

    2014-01-01

    Renal scintigraphy is performed commonly in dogs and cats and has been used in a variety of other species. In a 2012 survey of the members of the Society of Veterinary Nuclear Medicine, 95% of the respondents indicated they perform renal scintigraphy in their practice. Renal scintigraphy is primarily used to assess renal function and to evaluate postrenal obstruction. This article reviews how renal scintigraphy is used in veterinary medicine and describes the methods of analysis. Species variation is also discussed.

  5. Perioperative renal outcome in cardiac surgical patients with preoperative renal dysfunction: aprotinin versus epsilon aminocaproic acid.

    Science.gov (United States)

    Maslow, Andrew D; Chaudrey, Alyas; Bert, Arthur; Schwartz, Carl; Singh, Arun

    2008-02-01

    The administration of aprotinin to patients with pre-existing renal dysfunction who are undergoing cardiac surgery is controversial. Therefore, the authors present their experience with the use of aprotinin for patients with preoperative renal dysfunction who underwent elective cardiac surgery requiring cardiopulmonary bypass (CPB). Retrospective analysis. University hospital. Consecutive cardiac surgical patients with preoperative serum creatinine (SCr) > or =1.8 mg/dL undergoing nonemergent cardiac surgery requiring CPB. None. One hundred twenty-three patients either received epsilon aminocaproic acid (EACA, n = 82) or aprotinin (n = 41) as decided by the attending anesthesiologist and surgeon. Data were collected from the Society of Thoracic Surgeons database and from automated intraoperative anesthesia records. Renal function was assessed from measured serum creatinine (SCr) and calculated creatinine clearances (CrCls). Acute perioperative renal dysfunction was defined as a worsening of perioperative renal function by > or =25% and/or the need for hemodialysis (HD). Data were recorded as mean and standard deviation or percentage of population depending on whether the data were continuous or not. Data were compared by using an analysis of variance, chi-square analysis, Student paired and unpaired t tests, Fisher exact test, Wilcoxon rank sum test, and Mann-Whitney U test. A p value or =3 months after surgery was significantly lower in the aprotinin group compared with the EACA group (1.8 v 2.2 mg/dL, p < 0.05). Acute perioperative renal dysfunction was associated with worse patient outcome and longer CPB and AoXCl times. Demographic and surgical variables indicated that the sicker patients undergoing more complex surgeries were more likely to be treated with aprotinin. Although aprotinin patients had a higher renal risk score, the administration of aprotinin did not negatively impact renal outcome.

  6. Regeneration complexities of Pinus gerardiana in dry temperate forests of Indian Himalaya.

    Science.gov (United States)

    Kumar, Raj; Shamet, G S; Mehta, Harsh; Alam, N M; Kaushal, Rajesh; Chaturvedi, O P; Sharma, Navneet; Khaki, B A; Gupta, Dinesh

    2016-04-01

    Pinus gerardiana is considered an important species in dry temperate forests of North-Western Indian Himalaya because of its influence on ecological processes and economic dependence of local people in the region. But, large numbers of biotic and abiotic factors have affected P. gerardiana in these forests; hence, there is a crucial need to understand the regeneration dynamics of this tree species. The present investigation was conducted in P. gerardiana forests to understand vegetation pattern and regeneration processes on different sites in the region. Statistical analysis was performed to know variability in growing stock and regeneration on sample plots, while correlation coefficients and regression models were developed to find the relationship between regeneration and site factors. The vegetation study showed dominance of P. gerardiana, which is followed by Cedrus deodara, Pinus wallichiana and Quercus ilex in the region. The growing stock of P. gerardiana showed steep increasing and then steadily declining trend from lower to higher diameter class. The distribution of seedling, sapling, pole and trees was not uniform at different sites and less number of plots in each site were observed to have effective conditions for continuous regeneration, but mostly showed extremely limited regeneration. Regeneration success ranging from 8.44 to 15.93 % was recorded in different sites of the region, which suggests that in different sites regeneration success is influenced by collection of cone for extracting seed, grazing/browsing and physico-chemical properties of soil. Regeneration success showed significant correlation and relationship with most of abiotic and biotic factors. The regeneration success is lower than the requirement of sustainable forest, but varies widely among sites in dry temperate forests of Himalaya. More forest surveys are required to understand the conditions necessary for greater success of P. gerardiana in the region.

  7. Optical Regeneration and Noise in Semiconductor Devices

    DEFF Research Database (Denmark)

    Öhman, Filip

    2005-01-01

    In this report all-optical 2R-regeneration in optical communication systems is investigated. A simple regenerator device based on concatenated semiconductor optical amplifiers (SOAs) and electro absorbers (EAs) is introduced and examined. Experiments show that the monolithic SOA-EA 2R-regenerator......In this report all-optical 2R-regeneration in optical communication systems is investigated. A simple regenerator device based on concatenated semiconductor optical amplifiers (SOAs) and electro absorbers (EAs) is introduced and examined. Experiments show that the monolithic SOA-EA 2R...

  8. EGFR signaling regulates cell proliferation, differentiation and morphogenesis during planarian regeneration and homeostasis.

    Science.gov (United States)

    Fraguas, Susanna; Barberán, Sara; Cebrià, Francesc

    2011-06-01

    Similarly to development, the process of regeneration requires that cells accurately sense and respond to their external environment. Thus, intrinsic cues must be integrated with signals from the surrounding environment to ensure appropriate temporal and spatial regulation of tissue regeneration. Identifying the signaling pathways that control these events will not only provide insights into a fascinating biological phenomenon but may also yield new molecular targets for use in regenerative medicine. Among classical models to study regeneration, freshwater planarians represent an attractive system in which to investigate the signals that regulate cell proliferation and differentiation, as well as the proper patterning of the structures being regenerated. Recent studies in planarians have begun to define the role of conserved signaling pathways during regeneration. Here, we extend these analyses to the epidermal growth factor (EGF) receptor pathway. We report the characterization of three epidermal growth factor (EGF) receptors in the planarian Schmidtea mediterranea. Silencing of these genes by RNA interference (RNAi) yielded multiple defects in intact and regenerating planarians. Smed-egfr-1(RNAi) resulted in decreased differentiation of eye pigment cells, abnormal pharynx regeneration and maintenance, and the development of dorsal outgrowths. In contrast, Smed-egfr-3(RNAi) animals produced smaller blastemas associated with abnormal differentiation of certain cell types. Our results suggest important roles for the EGFR signaling in controlling cell proliferation, differentiation and morphogenesis during planarian regeneration and homeostasis.

  9. Neurotrophic regulation of fibroblast dedifferentiation during limb skeletal regeneration in the axolotl (Ambystoma mexicanum).

    Science.gov (United States)

    Satoh, Akira; Cummings, Gillian M C; Bryant, Susan V; Gardiner, David M

    2010-01-15

    The ability of animals to repair tissue damage is widespread and impressive. Among tissues, the repair and remodeling of bone occurs during growth and in response to injury; however, loss of bone above a threshold amount is not regenerated, resulting in a "critical-size defect" (CSD). The development of therapies to replace or regenerate a CSD is a major focus of research in regenerative medicine and tissue engineering. Adult urodeles (salamanders) are unique in their ability to regenerate complex tissues perfectly, yet like mammals do not regenerate a CSD. We report on an experimental model for the regeneration of a CSD in the axolotl (the Excisional Regeneration Model) that allows for the identification of signals to induce fibroblast dedifferentiation and skeletal regeneration. This regenerative response is mediated in part by BMP signaling, as is the case in mammals; however, a complete regenerative response requires the induction of a population of undifferentiated, regeneration-competent cells. These cells can be induced by signaling from limb amputation to generate blastema cells that can be grafted to the wound, as well as by signaling from a nerve and a wound epithelium to induce blastema cells from fibroblasts within the wound environment.

  10. Notch regulates blastema proliferation and prevents differentiation during adult zebrafish fin regeneration.

    Science.gov (United States)

    Münch, Juliane; González-Rajal, Alvaro; de la Pompa, José Luis

    2013-04-01

    Zebrafish have the capacity to regenerate several organs, including the heart and fins. Fin regeneration is epimorphic, involving the formation at the amputation plane of a mass of undifferentiated, proliferating mesenchymal progenitor-like cells, called blastema. This tissue provides all the cell types that form the fin, so that after damage or amputation the fin pattern and structure are fully restored. How blastema cells remain in this progenitor-like state is poorly understood. Here, we show that the Notch pathway plays an essential role during fin regeneration. Notch signalling is activated during blastema formation and remains active throughout the regeneration process. Chemical inhibition or morpholino-mediated knockdown of Notch signalling impairs fin regeneration via decreased proliferation accompanied by reduced expression of Notch target genes in the blastema. Conversely, overexpression of a constitutively active form of the Notch1 receptor (N1ICD) in the regenerating fin leads to increased proliferation and to the expansion of the blastema cell markers msxe and msxb, as well as increased expression of the proliferation regulator aldh1a2. This blastema expansion prevents regenerative fin outgrowth, as indicated by the reduction in differentiating osteoblasts and the inhibition of bone regeneration. We conclude that Notch signalling maintains blastema cells in a plastic, undifferentiated and proliferative state, an essential requirement for fin regeneration.

  11. A role for effectors of cellular immunity in epimorphic regeneration of amphibian limbs.

    Science.gov (United States)

    Fahmy, Gehan H; Sicard, Raymond E

    2002-01-01

    Immune modulation of regeneration of amphibian appendages is suggested, but not proven, by previous studies. Earlier studies have not demonstrated effects of treatments on both epimorphic regeneration and immune responses or restoration of regeneration by specific reversal of immunomodulation. Cyclosporin A (CsA) and interleukin-2 (IL-2) were used in this study to demonstrate the effects of immune suppression and its reversal, on allograft rejection and forelimb regeneration. When administered alone, CsA suppressed rejection of skin allografts and induced a dose-dependent retardation of regeneration. IL-2, administered alone, did not affect allograft rejection or regeneration. However, when combined with CsA, IL-2 abrogated or reversed effects of CsA on both allograft rejection and forelimb regeneration, in a dose-dependent manner. The selective focus of CsA's action and the ability of IL-2 to overcome and reverse these effects strongly suggest that T-lymphocytes participate in or contribute to expression of epimorphic regeneration of amphibian appendages. Further studies are required to better characterize this role.

  12. Neuregulin-1 signaling is essential for nerve-dependent axolotl limb regeneration.

    Science.gov (United States)

    Farkas, Johanna E; Freitas, Polina D; Bryant, Donald M; Whited, Jessica L; Monaghan, James R

    2016-08-01

    The Mexican axolotl (Ambystoma mexicanum) is capable of fully regenerating amputated limbs, but denervation of the limb inhibits the formation of the post-injury proliferative mass called the blastema. The molecular basis behind this phenomenon remains poorly understood, but previous studies have suggested that nerves support regeneration via the secretion of essential growth-promoting factors. An essential nerve-derived factor must be found in the blastema, capable of rescuing regeneration in denervated limbs, and its inhibition must prevent regeneration. Here, we show that the neuronally secreted protein Neuregulin-1 (NRG1) fulfills all these criteria in the axolotl. Immunohistochemistry and in situ hybridization of NRG1 and its active receptor ErbB2 revealed that they are expressed in regenerating blastemas but lost upon denervation. NRG1 was localized to the wound epithelium prior to blastema formation and was later strongly expressed in proliferating blastemal cells. Supplementation by implantation of NRG1-soaked beads rescued regeneration to digits in denervated limbs, and pharmacological inhibition of NRG1 signaling reduced cell proliferation, blocked blastema formation and induced aberrant collagen deposition in fully innervated limbs. Taken together, our results show that nerve-dependent NRG1/ErbB2 signaling promotes blastemal proliferation in the regenerating limb and may play an essential role in blastema formation, thus providing insight into the longstanding question of why nerves are required for axolotl limb regeneration.

  13. Primary renal synovial sarcoma

    Directory of Open Access Journals (Sweden)

    Girish D. Bakhshi

    2012-03-01

    Full Text Available Primary Renal Sarcoma is rare tumor comprising only 1% of all renal tumours. Synovial sarcomas are generally deep-seated tumors arising in the proximity of large joints of adolescents and young adults and account for 5-10% of all soft tissue tumours. Primary synovial sarcoma of kidney is rare and has poor prognosis. It can only be diagnosed by immunohistochemistry. It should be considered as a differential in sarcomatoid and spindle cell tumours. We present a case of 33-year-old female, who underwent left sided radical nephrectomy for renal tumour. Histopathology and genetic analysis diagnosed it to be primary renal synovial sarcoma. Patient underwent radiation therapy and 2 years follow up is uneventful. A brief case report with review of literature is presented.

  14. Renal protection in diabetes

    DEFF Research Database (Denmark)

    Parving, H H; Tarnow, L; Rossing, P

    1996-01-01

    BACKGROUND: The combination of diabetes and hypertension increases the chances of progressive renal disorder and, ultimately, renal failure. Roughly 40% of all diabetics, whether insulin-dependent or not, develop diabetic nephropathy. Diabetic nephropathy is the single most important cause of end......-stage renal disease in the Western world and accounts for more than a quarter of all end-stage renal diseases. Diabetic nephropathy is a major cause of increased morbidity and mortality in diabetic patients. Increased arterial blood pressure is an early and common phenomenon in incipient and overt diabetic...... nephropathy. The relationship between arterial blood pressure and diabetic nephropathy is a complex one, with diabetic nephropathy increasing blood pressure and blood pressure accelerating the course of nephropathy. OVERVIEW: Calcium antagonists antagonize preglomerular vasoconstriction. Additional putative...

  15. Renal primitive neuroectodermal tumors.

    Science.gov (United States)

    Bartholow, Tanner; Parwani, Anil

    2012-06-01

    Primitive neuroectodermal tumors exist as a part of the Ewing sarcoma/primitive neuroectodermal tumor family. These tumors most commonly arise in the chest wall and paraspinal regions; cases with a renal origin are rare entities, but have become increasingly reported in recent years. Although such cases occur across a wide age distribution, the average age for a patient with a renal primitive neuroectodermal tumor is the mid- to late 20s, with both males and females susceptible. Histologically, these tumors are characterized by pseudorosettes. Immunohistochemically, CD99 is an important diagnostic marker. Clinically, these are aggressive tumors, with an average 5-year disease-free survival rate of only 45% to 55%. Given that renal primitive neuroectodermal tumor bears many similarities to other renal tumors, it is important to review the histologic features, immunostaining profile, and genetic abnormalities that can be used for its correct diagnosis.

  16. Renal vein thrombosis

    Science.gov (United States)

    ... Saunders; 2012:chap 34. Read More Acute kidney failure Arteriogram Blood clots Dehydration Nephrotic syndrome Pulmonary embolus Renal Tumor Review Date 5/19/2015 Updated by: Charles Silberberg, ...

  17. Eligibility for renal denervation

    DEFF Research Database (Denmark)

    Persu, Alexandre; Jin, Yu; Baelen, Marie;

    2014-01-01

    -resistant hypertension (ENCOReD). The analysis included 731 patients. Age averaged 61.6 years, office blood pressure at screening was 177/96 mm Hg, and the number of blood pressure-lowering drugs taken was 4.1. Specialists referred 75.6% of patients. The proportion of patients eligible for renal denervation according......Based on the SYMPLICITY studies and CE (Conformité Européenne) certification, renal denervation is currently applied as a novel treatment of resistant hypertension in Europe. However, information on the proportion of patients with resistant hypertension qualifying for renal denervation after...... undetected secondary causes of hypertension (11.1%). In conclusion, after careful screening and treatment adjustment at hypertension expert centers, only ≈40% of patients referred for renal denervation, mostly by specialists, were eligible for the procedure. The most frequent cause of ineligibility...

  18. Complete renal recovery from severe acute renal failure after thrombolysis of bilateral renal vein thrombosis.

    Science.gov (United States)

    Ramadoss, Suresh; Jones, Robert G; Foggensteiner, Lukas; Willis, Andrew P; Duddy, Martin J

    2012-10-01

    A previously healthy young man presented with acute renal failure due to extensive spontaneous deep vein thrombosis, including the inferior vena cava (IVC) and both renal veins. The patient was treated with selectively delivered thrombolytic therapy over a 7-day-period, which resulted in renal vein patency and complete recovery of renal function. A stent was placed over a segment stenosis of the IVC. No thrombophilic factors were identified. Bilateral renal vein thrombosis in young fit individuals is an unusual cause of acute renal failure. Thrombolytic therapy, even with delay, can completely restore renal function.

  19. Management of Asymptomatic Renal Stones in Astronauts

    Science.gov (United States)

    Reyes, David; Locke, James

    2016-01-01

    significance. However, a small asymptomatic MRM or stone within the renal collecting system may become symptomatic, and so affect launch and flight schedules, cause incapacitation during flight, and ultimately require medical evacuation. For exploration class missions, evacuation is unlikely. The new screening and management algorithm allows better management of mission risks, and will define the true incidence of renal stones in U.S. astronauts. This information will be used to refine future screening, countermeasures and treatment methods; and will also inform the needed capabilities to be flown on exploration-class missions.

  20. Management of Asymptomatic Renal Stones in Astronauts

    Science.gov (United States)

    Reyes, David; Locke, James

    2016-01-01

    significance. However, a small asymptomatic MRM or stone within the renal collecting system may become symptomatic, and so affect launch and flight schedules, cause incapacitation during flight, and ultimately require medical evacuation. For exploration class missions, evacuation is unlikely. The new screening and management algorithm allows better management of mission risks, and will define the true incidence of renal stones in U.S. astronauts. This information will be used to refine future screening, countermeasures and treatment methods; and will also inform the needed capabilities to be flown on exploration-class missions.

  1. Renal papillary necrosis

    Directory of Open Access Journals (Sweden)

    Stephen A. Geller

    2013-12-01

    Full Text Available In 1877, Dr. Nikolaus Friedreich (1825-1882; student of Virchow who became Professor of Pathology at Heidelberg and who also described Friedreich’s ataxia first described renal papillary necrosis (RPN in patients with prostatic hypertrophy and secondary hydronephrosis. Thereafter in 1937, Froboese and Günther emphasized the association of this entity with diabetes mellitus. These authors also observed renal papillary necrosis in cases of urinary tract obstruction even in the absence of diabetes mellitus.

  2. [Hyperuricemia and renal risk].

    Science.gov (United States)

    Viazzi, Francesca; Bonino, Barbara; Ratto, Elena; Desideri, Giovambattista; Pontremoli, Roberto

    2015-01-01

    Recent studies have revealed an association between elevated levels of uric acid and conditions correlated to chronic kidney diseases such as hypertension, cardiovascular and cerebral disease, insulin resistance. Several pathogenetic mechanisms at cellular and tissue levels could justify a direct correlation between serum uric acid levels and renal damage. Growing evidence indicating a correlation between urate lowering therapy and renal morbidity could encourage the use of urate lowering therapy in primary or secondary prevention in chronic kidney disease.

  3. Cutaneous histoplasmosis in renal transplant recipients.

    Science.gov (United States)

    Sun, N Z; Augustine, J J; Gerstenblith, M R

    2014-10-01

    Cutaneous histoplasmosis is a rare entity, although it can be seen in a substantial portion of renal transplant recipients with disseminated disease. The prognosis of disseminated disease is worse than isolated cutaneous involvement, and significant delays in diagnosis are reported. We reviewed reports of cutaneous histoplasmosis with and without dissemination in the setting of renal transplantation to examine incidence, timing of diagnosis, clinical features, and prognosis. Remarkable morphologic variability and the non-specific appearance of skin findings suggest that tissue culture is required for definitive diagnosis. Cutaneous lesions represent an easily accessible source for early diagnosis.

  4. Limb Regeneration in Xenopus laevis Froglet

    Directory of Open Access Journals (Sweden)

    Makoto Suzuki

    2006-01-01

    Full Text Available Limb regeneration in amphibians is a representative process of epimorphosis. This type of organ regeneration, in which a mass of undifferentiated cells referred to as the “blastema” proliferate to restore the lost part of the amputated organ, is distinct from morphallaxis as observed, for instance, in Hydra, in which rearrangement of pre-existing cells and tissues mainly contribute to regeneration. In contrast to complete limb regeneration in urodele amphibians, limb regeneration in Xenopus, an anuran amphibian, is restricted. In this review of some aspects regarding adult limb regeneration in Xenopus laevis, we suggest that limb regeneration in adult Xenopus, which is pattern/tissue deficient, also represents epimorphosis.

  5. Retroperitoneoscopic renal biopsy in children

    Directory of Open Access Journals (Sweden)

    Carlos M. Jesus

    2007-08-01

    Full Text Available OBJECTIVE: We present our experience in a series of 17 consecutive pediatric patients submitted to retroperitoneal laparoscopic renal biopsy. MATERIALS AND METHODS: Retroperitoneal laparoscopic renal biopsy (LRB was performed in 5 boys and 12 girls. Mean age was 8.1 years and age range from 2 to 12. Two or three trocars were used to expose the inferior pole of the kidney, remove enough cortical parenchymal specimen and fulgurate the biopsy site. Assessment included surgical time, estimated blood loss, hospitalization period, analgesia requirements, complications and number of glomeruli present in the specimen. RESULTS: LRB was successfully performed in all 15 patients (88%. In two cases, LRB was not possible to be performed. One patient was converted to a transperitoneal laparoscopy due to tear in the peritoneum. The other patient had had previous abdominal surgery and, during retroperitoneal balloon dilation, the peritoneum was opened and the open biopsy was performed. A third patient had postoperatively a perirenal hematoma, which was solved spontaneously. Complication rate was 17.6% (3/17 cases. Mean operative time was 65 minutes, while mean estimated blood loss was 52 mL, mean hospital stay was 2.2 days and mean analgesic requirement was 100 mg of tramadol. The mean number of glomeruli present in the specimen was 60. CONCLUSION: Retroperitoneal laparoscopic renal biopsy in children is a simple, safe. Bleeding is still the most common complication. However, direct vision usually allows a safe control of this drawback. In our institution, laparoscopic approach is the chosen procedure in pediatric patients older than one - year - old.

  6. Muscle repair and regeneration: stem cells, scaffolds, and the contributions of skeletal muscle to amphibian limb regeneration.

    Science.gov (United States)

    Milner, Derek J; Cameron, Jo Ann

    2013-01-01

    Skeletal muscle possesses a robust innate capability for repair of tissue damage. Natural repair of muscle damage is a stepwise process that requires the coordinated activity of a number of cell types, including infiltrating macrophages, resident myogenic and non-myogenic stem cells, and connective tissue fibroblasts. Despite the proficiency of this intrinsic repair capability, severe injuries that result in significant loss of muscle tissue overwhelm the innate repair process and require intervention if muscle function is to be restored. Recent advances in stem cell biology, regenerative medicine, and materials science have led to attempts at developing tissue engineering-based methods for repairing severe muscle defects. Muscle tissue also plays a role in the ability of tailed amphibians to regenerate amputated limbs through epimorphic regeneration. Muscle contributes adult stem cells to the amphibian regeneration blastema, but it can also contribute blastemal cells through the dedifferentiation of multinucleate myofibers into mononuclear precursors. This fascinating plasticity and its contributions to limb regeneration have prompted researchers to investigate the potential for mammalian muscle to undergo dedifferentiation. Several works have shown that mammalian myotubes can be fragmented into mononuclear cells and induced to re-enter the cell cycle, but mature myofibers are resistant to fragmentation. However, recent works suggest that there may be a path to inducing fragmentation of mature myofibers into proliferative multipotent cells with the potential for use in muscle tissue engineering and regenerative therapies.

  7. Arterial spin labeling MR imaging for characterisation of renal masses in patients with impaired renal function: initial experience

    Energy Technology Data Exchange (ETDEWEB)

    Pedrosa, Ivan [Beth Israel Deaconess Medical Center and Harvard Medical School, Department of Radiology, Boston, MA (United States); UT Southwestern Medical Center, Department of Radiology, Dallas, TX (United States); Rafatzand, Khashayar; Robson, Philip; Alsop, David C. [Beth Israel Deaconess Medical Center and Harvard Medical School, Department of Radiology, Boston, MA (United States); Wagner, Andrew A. [Beth Israel Deaconess Medical Center and Harvard Medical School, Surgery, Division of Urology, Boston, MA (United States); Atkins, Michael B. [Beth Israel Deaconess Medical Center and Harvard Medical School, Hematology/Oncology, Boston, MA (United States); Rofsky, Neil M. [University of Texas Southwestern Medical Center, Departments of Radiology, Dallas, TX (United States)

    2012-02-15

    To retrospectively evaluate the feasibility of arterial spin labeling (ASL) magnetic resonance imaging (MRI) for the assessment of vascularity of renal masses in patients with impaired renal function. Between May 2007 and November 2008, 11/67 consecutive patients referred for MRI evaluation of a renal mass underwent unenhanced ASL-MRI due to moderate-to-severe chronic or acute renal failure. Mean blood flow in vascularised and non-vascularised lesions and the relation between blood flow and final diagnosis of malignancy were correlated with a 2-sided homogeneous variance t-test and the Fisher Exact Test, respectively. A p value <0.05 was considered statistically significant. Seventeen renal lesions were evaluated in 11 patients (8 male; mean age = 70 years) (range 57-86). The median eGFR was 24 mL/min/1.73 m{sup 2} (range 7-39). The average blood flow of 11 renal masses interpreted as ASL-positive (134 +/- 85.7 mL/100 g/min) was higher than that of 6 renal masses interpreted as ASL-negative (20.5 +/- 8.1 mL/100 g/min)(p = 0.015). ASL-positivity correlated with malignancy (n = 3) or epithelial atypia (n = 1) at histopathology or progression at follow up (n = 7). ASL detection of vascularity in renal masses in patients with impaired renal function is feasible and seems to indicate neoplasia although the technique requires further evaluation. (orig.)

  8. Laparoscopic Renal Cryoablation

    Science.gov (United States)

    Schiffman, Marc; Moshfegh, Amiel; Talenfeld, Adam; Del Pizzo, Joseph J.

    2014-01-01

    In light of evidence linking radical nephrectomy and consequent suboptimal renal function to adverse cardiovascular events and increased mortality, research into nephron-sparing techniques for renal masses widely expanded in the past two decades. The American Urological Association (AUA) guidelines now explicitly list partial nephrectomy as the standard of care for the management of T1a renal tumors. Because of the increasing utilization of cross-sectional imaging, up to 70% of newly detected renal masses are stage T1a, making them more amenable to minimally invasive nephron-sparing therapies including laparoscopic and robotic partial nephrectomy and ablative therapies. Cryosurgery has emerged as a leading option for renal ablation, and compared with surgical techniques it offers benefits in preserving renal function with fewer complications, shorter hospitalization times, and allows for quicker convalescence. A mature dataset exists at this time, with intermediate and long-term follow-up data available. Cryosurgical recommendations as a first-line therapy are made at this time in limited populations, including elderly patients, patients with multiple comorbidities, and those with a solitary kidney. As more data emerge on oncologic efficacy, and technical experience and the technology continue to improve, the application of this modality will likely be extended in future treatment guidelines. PMID:24596441

  9. Neonatal renal vein thrombosis.

    Science.gov (United States)

    Brandão, Leonardo R; Simpson, Ewurabena A; Lau, Keith K

    2011-12-01

    Neonatal renal vein thrombosis (RVT) continues to pose significant challenges for pediatric hematologists and nephrologists. The precise mechanism for the onset and propagation of renal thrombosis within the neonatal population is unclear, but there is suggestion that acquired and/or inherited thrombophilia traits may increase the risk for renal thromboembolic disease during the newborn period. This review summarizes the most recent studies of neonatal RVT, examining its most common features, the prevalence of acquired and inherited prothrombotic risk factors among these patients, and evaluates their short and long term renal and thrombotic outcomes as they may relate to these risk factors. Although there is some consensus regarding the management of neonatal RVT, the most recent antithrombotic therapy guidelines for the management of childhood thrombosis do not provide a risk-based algorithm for the acute management of RVT among newborns with hereditary prothrombotic disorders. Whereas neonatal RVT is not a condition associated with a high mortality rate, it is associated with significant morbidity due to renal impairment. Recent evidence to evaluate the effects of heparin-based anticoagulation and thrombolytic therapy on the long term renal function of these patients has yielded conflicting results. Long term cohort studies and randomized trials may be helpful to clarify the impact of acute versus prolonged antithrombotic therapy for reducing the morbidity that is associated with neonatal RVT.

  10. Bone marrow-derived cells mobilized by granulocyte-colony stimulating factor facilitate vascular regeneration in mouse kidney after ischemia/reperfusion injury.

    Science.gov (United States)

    Akihama, Susumu; Sato, Kazunari; Satoh, Shigeru; Tsuchiya, Norihiko; Kato, Tetsuro; Komatsuda, Atsushi; Hirokawa, Makoto; Sawada, Kenichi; Nanjo, Hiroshi; Habuchi, Tomonori

    2007-12-01

    Bone marrow-derived cells (BMDC) play crucial roles in tissue regeneration. Granulocyte-colony stimulating factor (G-CSF) mobilizes BMDC and may facilitate the repair of kidney tissues after ischemia/reperfusion (I/R) injury. The tissue protective action of resveratrol, an antioxidant, might modify the regenerating potential of BMDC in I/R renal injury. This study examined whether G-CSF and/or resveratrol affect the recruitment of BMDC into vascular endothelial cells and renal tubular cells and the kidney function after I/R injury. I/R renal injury was induced in female mice that had been lethally irradiated and transplanted with male bone marrow cells. The mice were given saline, resveratrol or G-CSF, daily for 7 days. Non-irradiated and non-bone-marrow-transplanted female mice, which underwent the same kidney injury, were included as control. White blood cell (WBC) count and serum creatinine were monitored. Immunohistologic evaluation for renal tubular cells (cytokeratin) and endothelial cells (factor VIII-related antigen), and fluorescence in situ hybridization for mouse Y chromosome were performed. Although WBC was significantly higher in the G-CSF group, there was no significant difference in creatinine levels among all groups. Factor VIII-related antigen-positive cells with a Y-chromosome signal were identified in the capillary wall between renal tubuli and most frequently seen in the G-CSF group (p cells having a Y-chromosome signal were identified. In conclusion, BMDC are recruited into endothelial cell in I/R renal injury without apparent renal tubular cell regeneration, and G-CSF facilitates the endothelial cell regeneration.

  11. Targeting Strategies for Renal Cell Carcinoma: From Renal Cancer Cells to Renal Cancer Stem Cells

    OpenAIRE

    Zhi-xiang Yuan; Jingxin Mo; Guixian Zhao; Gang Shu; Hua-lin Fu; Wei Zhao

    2016-01-01

    Renal cell carcinoma (RCC) is a common form of urologic tumor that originates from the highly heterogeneous epithelium of renal tubules. Over the last decade, targeting therapies to renal cancer cells have transformed clinical care for RCC. Recently, it was proposed that renal cancer stem cells (CSCs) isolated from renal carcinomas were responsible for driving tumor growth and resistance to conventional chemotherapy and radiotherapy, according to the theory of CSCs; this has provided the rati...

  12. RENAL MALIGNANT NEOPLASMS: RENAL CELL CARCINOMA

    Directory of Open Access Journals (Sweden)

    Elisangela Giachini

    2017-06-01

    Full Text Available The aim of this study is to evaluate the incidence and prevalence of malignant kidney tumors, to contribute to identifying factors which the diagnosis of renal cell carcinomas. Through this study, we understand that kidney disease over the years had higher incidence rates, especially in adults in the sixth decade of life. The renal cell carcinoma (RCC is the third most common malignancy of the genitourinary tract, affecting 2% to 3% of the population. There are numerous ways of diagnosis; however, the most important are ultrasonography, magnetic resonance imaging and computed tomography. In general most of the patients affected by the CCR, have a good prognosis when diagnosed early and subjected to an effective treatment. This study conducted a literature review about the CCR, through this it was possible to understand the development needs of the imaging methods used for precise diagnosis and classification of RCC through the TNM system.

  13. Development of regeneration technique for diesel particulate filter made of porous metal; Kinzoku takotai DPF no saisei gijutsu no kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    Yoro, K.; Ban, S.; Ooka, T.; Saito, H.; Oji, M.; Nakajima, S.; Okamoto, S. [Sumitomo Electric Industries, Ltd., Osaka (Japan)

    1997-10-01

    We have developed the diesel particulate filter (DPF) in which porous metal is used for a filter because of its high thermal conductivity and a radiation heater is used for a regeneration device because of its uniform thermal distribution. In the case high trapping efficiency is required, filter thickness should be thick. The thicker filter has a disadvantage of difficulty in regeneration because of the thermal distribution in the direction of thickness. In order to improve regeneration efficiency, we designed the best filter-heater construction which achieves uniform thermal distribution by using computer simulation and we confirmed good regeneration efficiency in the experiment. 4 refs., 14 figs., 1 tab.

  14. Local Regeneration of Dentin-Pulp Complex Using Controlled Release of FGF-2 and Naturally Derived Sponge-Like Scaffolds

    Directory of Open Access Journals (Sweden)

    Chiaki Kitamura

    2012-01-01

    Full Text Available Restorative and endodontic procedures have been recently developed in an attempt to preserve the vitality of dental pulp after exposure to external stimuli, such as caries infection or traumatic injury. When damage to dental pulp is reversible, pulp wound healing can proceed, whereas irreversible damage induces pathological changes in dental pulp, eventually requiring its removal. Nonvital teeth lose their defensive abilities and become severely damaged, resulting in extraction. Development of regeneration therapy for the dentin-pulp complex is important to overcome limitations with presently available therapies. Three strategies to regenerate the dentin-pulp complex have been proposed; regeneration of the entire tooth, local regeneration of the dentin-pulp complex from amputated dental pulp, and regeneration of dental pulp from apical dental pulp or periapical tissues. In this paper, we focus on the local regeneration of the dentin-pulp complex by application of exogenous growth factors and scaffolds to amputated dental pulp.

  15. Selective amputation of the pharynx identifies a FoxA-dependent regeneration program in planaria

    Science.gov (United States)

    Adler, Carolyn E; Seidel, Chris W; McKinney, Sean A; Sánchez Alvarado, Alejandro

    2014-01-01

    Planarian flatworms regenerate every organ after amputation. Adult pluripotent stem cells drive this ability, but how injury activates and directs stem cells into the appropriate lineages is unclear. Here we describe a single-organ regeneration assay in which ejection of the planarian pharynx is selectively induced by brief exposure of animals to sodium azide. To identify genes required for pharynx regeneration, we performed an RNAi screen of 356 genes upregulated after amputation, using successful feeding as a proxy for regeneration. We found that knockdown of 20 genes caused a wide range of regeneration phenotypes and that RNAi of the forkhead transcription factor FoxA, which is expressed in a subpopulation of stem cells, specifically inhibited regrowth of the pharynx. Selective amputation of the pharynx therefore permits the identification of genes required for organ-specific regeneration and suggests an ancient function for FoxA-dependent transcriptional programs in driving regeneration. DOI: http://dx.doi.org/10.7554/eLife.02238.001 PMID:24737865

  16. Impaired Muscle Regeneration in Ob/ob and Db/db Mice

    Directory of Open Access Journals (Sweden)

    Mai-Huong Nguyen

    2011-01-01

    Full Text Available In obesity and type 2 diabetes, efficient skeletal muscle repair following injury may be required, not only for restoring muscle structure and function, but also for maintaining exercise capacity and insulin sensitivity. The hypothesis of this study was that muscle regeneration would be impaired in ob/ob and db/db mice, which are common mouse models of obesity and type 2 diabetes. Muscle injury was produced by cardiotoxin injection, and regeneration was assessed by morphological and immunostaining techniques. Muscle regeneration was delayed in ob/ob and db/db mice, but not in a less severe model of insulin resistance – feeding a high-fat diet to wild-type mice. Angiogenesis, cell proliferation, and myoblast accumulation were also impaired in ob/ob and db/db mice, but not the high-fat diet mice. The impairments in muscle regeneration were associated with impaired macrophage accumulation; macrophages have been shown previously to be required for efficient muscle regeneration. Impaired regeneration in ob/ob and db/db mice could be due partly to the lack of leptin signaling, since leptin is expressed both in damaged muscle and in cultured muscle cells. In summary, impaired muscle regeneration in ob/ob and db/db mice was associated with reduced macrophage accumulation, angiogenesis, and myoblast activity, and could have implications for insulin sensitivity in the skeletal muscle of obese and type 2 diabetic patients.

  17. Tissue Engineering Considerations in Dental Pulp Regeneration

    Science.gov (United States)

    Nosrat, Ali; Kim, Jong Ryul; Verma, Prashant; S. Chand, Priya

    2014-01-01

    Regenerative endodontic procedure is introduced as a biologically based treatment for immature teeth with pulp necrosis. Successful clinical and radiographic outcomes following regenerative procedures have been reported in landmark case reports. Retrospective studies have shown that this conservative treatment allows for continued root development and increases success and survival rate of the treated teeth compared to other treatment options. Although the goal of treatment is regeneration of a functional pulp tissue, histological analyses show a different outcome. Developing predictable protocols would require the use of key elements for tissue engineering: stem cells, bioactive scaffolds, and growth factors. In this study we will review the evidence based steps and outcomes of regenerative endodontics. PMID:24396373

  18. Guided tissue regeneration. Absorbable barriers.

    Science.gov (United States)

    Wang, H L; MacNeil, R L

    1998-07-01

    Over the past 15 years, techniques aimed at regeneration of lost periodontal tissue have become widely used and accepted in clinical practice. Among these techniques are those which use the principles of guided tissue regeneration (GTR), wherein barriers (i.e., membranes) are used to control cell and tissue repopulation of the periodontal wound. A variety of non-absorbable and absorbable barriers have been developed and used for this purpose, with a trend in recent years toward increased use of absorbable GTR materials. This article describes the evolution of absorbable barrier materials and overview materials available for clinical use today. In addition, advantages and disadvantages of these materials are discussed, as well as possible new developments in barrier-based GTR therapy.

  19. Cardiac regeneration from activated epicardium.

    Directory of Open Access Journals (Sweden)

    Bram van Wijk

    Full Text Available In contrast to lower vertebrates, the mammalian heart has a very limited regenerative capacity. Cardiomyocytes, lost after ischemia, are replaced by fibroblasts. Although the human heart is able to form new cardiomyocytes throughout its lifespan, the efficiency of this phenomenon is not enough to substitute sufficient myocardial mass after an infarction. In contrast, zebrafish hearts regenerate through epicardial activation and initiation of myocardial proliferation. With this study we obtain insights into the activation and cellular contribution of the mammalian epicardium in response to ischemia. In a mouse myocardial infarction model we analyzed the spatio-temporal changes in expression of embryonic epicardial, EMT, and stem cell markers and the contribution of cells of the Wt1-lineage to the infarcted area. Though the integrity of the epicardial layer overlaying the infarct is lost immediately after the induction of the ischemia, it was found to be regenerated at three days post infarction. In this regenerated epicardium, the embryonic gene program is transiently re-expressed as well as proliferation. Concomitant with this activation, Wt1-lineage positive subepicardial mesenchyme is formed until two weeks post-infarction. These mesenchymal cells replace the cardiomyocytes lost due to the ischemia and contribute to the fibroblast population, myofibroblasts and coronary endothelium in the infarct, and later also to the cardiomyocyte population. We show that in mice, as in lower vertebrates, an endogenous, epicardium-dependent regenerative response to injury is induced. Although this regenerative response leads to the formation of new cardiomyocytes, their number is insufficient in mice but sufficient in lower vertebrates to replace lost cardiomyocytes. These molecular and cellular analyses provide basic knowledge essential for investigations on the regeneration of the mammalian heart aiming at epicardium-derived cells.

  20. Pulp-dentin Regeneration: Current State and Future Prospects.

    Science.gov (United States)

    Cao, Y; Song, M; Kim, E; Shon, W; Chugal, N; Bogen, G; Lin, L; Kim, R H; Park, N-H; Kang, M K

    2015-11-01

    The goal of regenerative endodontics is to reinstate normal pulp function in necrotic and infected teeth that would result in reestablishment of protective functions, including innate pulp immunity, pulp repair through mineralization, and pulp sensibility. In the unique microenvironment of the dental pulp, the triad of tissue engineering would require infection control, biomaterials, and stem cells. Although revascularization is successful in resolving apical periodontitis, multiple studies suggest that it alone does not support pulp-dentin regeneration. More recently, cell-based approaches in endodontic regeneration based on pulpal mesenchymal stem cells (MSCs) have demonstrated promising results in terms of pulp-dentin regeneration in vivo through autologous transplantation. Although pulpal regeneration requires the cell-based approach, several challenges in clinical translation must be overcome-including aging-associated phenotypic changes in pulpal MSCs, availability of tissue sources, and safety and regulation involved with expansion of MSCs in laboratories. Allotransplantation of MSCs may alleviate some of these obstacles, although the long-term stability of MSCs and efficacy in pulp-dentin regeneration demand further investigation. For an alternative source of MSCs, our laboratory developed induced MSCs (iMSCs) from primary human keratinocytes through epithelial-mesenchymal transition by modulating the epithelial plasticity genes. Initially, we showed that overexpression of ΔNp63α, a major isoform of the p63 gene, led to epithelial-mesenchymal transition and acquisition of stem characteristics. More recently, iMSCs were generated by transient knockdown of all p63 isoforms through siRNA, further simplifying the protocol and resolving the potential safety issues of viral vectors. These cells may be useful for patients who lack tissue sources for endogenous MSCs. Further research will elucidate the level of potency of these iMSCs and assess their

  1. Thermodynamic simulation of a rotating Ericsson-cycle magnetic refrigerator without a regenerator

    Science.gov (United States)

    Hakuraku, Y.

    1987-09-01

    A magnetic Ericsson cycle, which consists of two isothermal stages and two isofield stages, is generally thought to require regenerators. However, a new concept makes it possible to realize magnetic refrigerators capable of executing an Ericsson-cycle without using regenerators. The basic principle lies in directly linking the two isofield changes by transferring heat between the isofield stages through heat paths rather than through regenerators. A fundamental configuration is proposed for a rotating magnetic refrigerator that operates based on this concept. A simulation of the thermodynamic cycle in this simplified refrigerator model shows that the system is theoretically feasible.

  2. A study on the regeneration performance characteristics of an internally heated regenerator in a liquid desiccant system

    Energy Technology Data Exchange (ETDEWEB)

    Mun, Ji Hyun [Korea University of Science and Technology, Daejeon (Korea, Republic of); Jeon, Dong Soon; Kim, Young Lyoul; Kim, Seon Chang [Korea Institute of Industrial Technology, Cheonan (Korea, Republic of)

    2016-03-15

    This paper presents a study on the regeneration performance characteristics of an internally heated regenerator applicable to a liquid desiccant system. The internally heated regenerator used in this study was designed and manufactured to provide better regeneration performance. An experimental setup was established to examine the regeneration performance. LiCl aqueous solution was used as working fluid. Variables to evaluate regeneration performance characteristics of the internally heated regenerator were dry bulb temperature, relative humidity and velocity of regeneration air, mass flow rate, temperature and concentration of the LiCl aqueous solution. The experimental conditions were chosen by using a 1/2 fractional factorial DOE. Regeneration rate and regeneration effectiveness were taken as results. From the results, solution concentration and regeneration air relative humidity have strong effects on the regeneration rate. The regeneration effectiveness was affected mostly by regeneration air velocity.

  3. Malignant renal tumors in children

    Directory of Open Access Journals (Sweden)

    Justin Scott Lee

    2015-05-01

    Full Text Available Renal malignancies are common in children. While the majority of malignant renal masses are secondary to Wilms tumor, it can be challenging to distinguish from more aggressive renal masses. For suspicious renal lesions, it is crucial to ensure prompt diagnosis in order to select the appropriate surgical procedure and treatment. This review article will discuss the common differential diagnosis that can be encountered when evaluating a suspicious renal mass in the pediatric population. This includes clear cell sarcoma of the kidney, malignant rhabdoid tumor, renal medullary carcinoma and lymphoma. 

  4. Myoclonus in renal failure: Two cases of gabapentin toxicity

    Directory of Open Access Journals (Sweden)

    Kenneth R. Kaufman

    2014-01-01

    Full Text Available Gabapentin, an AED approved for the adjunctive treatment of partial seizures with/without secondary generalization and for the treatment of postherpetic neuralgia, is frequently used off-label for the treatment of both psychiatric and pain disorders. Since gabapentin is cleared solely by renal excretion, dosing requires consideration of the patient's renal function. Myoclonic activity may occur as a complication of gabapentin toxicity, especially with acute kidney injury or end-stage renal disease. We report 2 cases of myoclonic activity associated with gabapentin toxicity in the setting of renal disease which resolved with discontinuation of gabapentin and treatment with hemodialysis and peritoneal dialysis. As gabapentin has multiple indications and off-label uses, an understanding of myoclonus, neurotoxicity, and renal dosing is important to clinicians in multiple specialties.

  5. Energetic costs of loss and regeneration of arms in stellate echinoderms.

    Science.gov (United States)

    Lawrence, John M

    2010-10-01

    Loss of arms has energetic consequences for stellate echinoderms (crinoids, ophiuroids, and asteroids). The energetic cost of losing an arm includes loss of investment, decrease in ability to obtain nutrients and allocation of nutrients to regeneration of the lost arms at a cost to other body compartments. The cost to other body compartments is low when food availability is very low or very high. The cost becomes apparent when food availability is sufficient to support production but not high enough that the cost of regeneration has no effect on production of other body compartments. Loss of investment is greater in asteroids than in crinoids and ophiuroids because of greater development of the body wall and presence of gonads and pyloric caeca in the arms. The cost of regeneration of organic matter in an arm can be estimated from the amount of organic matter present in intact arms and the cost of anabolism. Protein production is the primary cost of regeneration of an arm because of the high concentration of protein in the regenerated arm and the high anabolic cost of protein production. A major energetic cost of loss of arms that affects regeneration is decrease in food consumption. It is necessary to separate cost of decrease in consumption from cost of regeneration. Comparison of intact and regenerating individuals requires they consume the same amount of food. The cost of regeneration will also be affected by the quality of food because of the nutrient requirements for growth. Because the quantity and quality of the food ingested is not known, it is not possible to quantify the cost of regeneration in the field. Asteroids appear to be a good model for the study of regeneration in the laboratory because it is possible to control the quantity and quality of food they ingest. They are also a good model for the study of the evolutionary significance of regeneration by comparing individuals that have lost arms and are regenerating them to those that have lost arms

  6. Collagen based barrier membranes for periodontal guided bone regeneration applications.

    Science.gov (United States)

    Sheikh, Zeeshan; Qureshi, Javairia; Alshahrani, Abdullah M; Nassar, Heba; Ikeda, Yuichi; Glogauer, Michael; Ganss, Bernhard

    2017-01-01

    Certain cell populations within periodontal tissues possess the ability to induce regeneration, provided they have the opportunity to populate the wound or defect. Guided regeneration techniques have been investigated for regenerating periodontal tissues and such therapies usually utilize barrier membranes. Various natural and synthetic barrier membranes have been fabricated and tested to prevent epithelial and connective tissue cells from invading while allowing periodontal cells to selectively migrate into the defect. This paper focuses on the literature relevant to the use and potential of resorbable collagen membranes in GBR procedures, sites of periodontal and intrabony defects, in cases of socket and alveolar ridge preservation and at implant sites. The results of their use in GBR procedures has shown them to be effective and comparable with non-resorbable membranes with regards to clinical attachment gain, probing depth reduction and defect bone filling. They have also shown to prevent epithelial ingrowth into the defect space during the initial wound healing phase postsurgically. Collagen membranes have also been used for root coverage and GBR procedures and have shown good success rates comparable to subepithelial connective tissue grafts and expanded-polytetrafluoroethylene (e-PTFE) membranes. The future for periodontal tissue engineering is very exciting with the use of barrier membranes expected to continue playing a critical role. However, long-term clinical trials are required to further evaluate and confirm the efficacy of the available collagen barrier membranes for periodontal and bone regeneration use.

  7. Sampling forest tree regeneration with a transect approach

    Directory of Open Access Journals (Sweden)

    D. Hessenmöller

    2013-05-01

    Full Text Available A new transect approach for sampling forest tree regeneration isdeveloped with the aim to minimize the amount of field measurements, and to produce an accurate estimation of tree species composition and density independent of tree height. This approach is based on the “probability proportional to size” (PPS theory to assess heterogeneous vegetation. This new method is compared with other approaches to assess forest regeneration based on simulated and measured, real data. The main result is that the transect approach requires about 50% of the time to assess stand density as compared to the plot approach, due to the fact that only 25% of the tree individuals are measured. In addition, tall members of the regeneration are counted with equal probability as small members. This is not the case in the plot approach. The evenness is 0.1 to 0.2 units larger in the transect by PPS than in the plot approach, which means that the plot approach shows a more homogeneous regeneration layer than the PPS approach, even though the stand densities and height distributions are similar. The species diversity is variable in both approaches and needs further investigations.

  8. Nano-odontology: nanostructured assemblies for endodontic regeneration.

    Science.gov (United States)

    Fioretti, F; Mendoza-Palomares, C; Avoaka-Boni, M C; Ramaroson, J; Bahi, S; Richert, L; Granier, F; Benkirane-Jessel, N; Haikel, Y

    2011-06-01

    The vitality of the pulp is so fundamental to the functional life of the tooth that new strategies are required to avoid the removal of the whole pulp following irreversible pulpitis and to regenerate the lost endodontic tissues. Nano-odontology would provide suitable solutions for pulp tissue conservative and regenerative approaches. In our group, we have shown that when covalently coupled to Poly-Glutamic Acid (PGA) the incorporation of an anti-inflammatory hormone (melanocortin, a-MSH) into the multilayered films Poly-L-Lysine (PLL)/PGA increases the anti-inflammatory reaction of pulp fibroblasts and macrophages stimulated by LPS (Lipo-Polysaccharides). Recently, usual linear PLL polymers have been chemically grafted for making new Dendrigraft polymers (DGLG4) whose higher branching ratios can give useful properties. The objective is to use nanostructured assemblies containing DGLG4 and PGA-alpha-MSH to design a new nanomaterial. These nanostructured assemblies (DGLG4-PGA-alpha-MSH)n constitute a thick reservoir of the anti-inflammatory peptide and promote adhesion and proliferation of pulp fibroblast on the biomaterial surface. These nanostructured films could be adapted for an endodontic regeneration application to target pulp connective tissue regeneration. Firstly, the crucial reduction of inflammation could be helpful by using PGA-alpha-MSH and secondly the initiation of the regeneration of the connective tissue will be promoted by the whole nanostructured film of which allows pulp cells colonisation.

  9. Standardisation of sheep model for endodontic regeneration/revitalisation research.

    Science.gov (United States)

    Altaii, Milad; Broberg, Marita; Cathro, Peter; Richards, Lindsay

    2016-05-01

    Different endodontic regeneration/revitalisation protocols have been suggested for the treatment of immature permanent teeth with pulp necrosis. Many aspects of these protocols require further investigating necessitating a suitable standardised animal model for research purposes. The focus of this study was to examine the anatomy and histology of sheep teeth at different stages of development to find an appropriate dental age for endodontic regeneration/revitalisation research. Sheep teeth at mature and immature dental ages were investigated. Standardized radiography, computed tomography, and histology were used to measure root length, apical-third dentine thickness and apex diameter, and to evaluate tissue development stages. A mature sheep tooth has an apical area which consists of a major foramen, intermediate dilatation and minor foramen. From the time of eruption to maturation no major changes occur in the incisor root lengths, but the apical foramen width decreases and the dentinal wall thickness increases. The two-tooth age exhibited the most similar features to that of an immature permanent human tooth. Sheep appears to be an appropriate animal model for endodontic regeneration/revitalization research with similar dimension and characteristics to human anterior teeth. Each dental age has its advantages and disadvantages. The two-tooth age showed the most favourable criteria making this age the most suitable for in vivo regeneration/revitalisation research. Copyright © 2016. Published by Elsevier Ltd.

  10. Sampling forest tree regeneration with a transect approach

    Directory of Open Access Journals (Sweden)

    D. Hessenmoeller

    2013-07-01

    Full Text Available A new transect approach for sampling forest tree regeneration is developed with the aim to minimize the amount of field measurements, and to produce an accurate estimation of tree species composition and density independent of tree height. This approach is based on the “probability proportional to size” (PPS theory to assess heterogeneous vegetation. This new method is compared with other approaches to assess forest regeneration based on simulated and measured, real data. The main result is that the transect approach requires about 50% of the time to assess stand density as compared to the plot approach, due to the fact that only 25% of the tree individuals are measured. In addition, tall members of the regeneration are counted with equal probability as small members. This is not the case in the plot approach. The evenness is 0.1 to 0.2 units larger in the transect by PPS than in the plot approach, which means that the plot approach shows a more homogenous regeneration layer than the PPS approach, even though the stand densities and height distributions are similar. The species diversity is variable in both approaches and needs further investigations.

  11. Multiple Renal Abscesses due to ESBL Extended-Spectrum Beta-Lactamase-Producing Escherichia coli Causing Acute Pyelonephritis and Bacteremia: A Case Report with a Good Outcome (No Drainage Required)

    Science.gov (United States)

    Qurash, Musaad; Saleh, Asem; Ali, Rasha

    2016-01-01

    Extended-spectrum beta-lactamase-producing Enterobacteriaceae urinary tract infections are challenging infections with increased mortality, morbidity, and failure of therapy. A 44-year-old Saudi male diabetic patient was seen at the ER of IMC Hospital with features of acute pyelonephritis: fever, burning urine, and left flank pain for three days. He was treated for cystitis at the Endocrine Clinic two weeks prior to his ER visit with nitrofurantoin and levofloxacin orally according to urine culture and sensitivity result. The patient was admitted, received IV meropenem, and continued to be febrile for three days. His urine and blood culture at ER grew the same ESBL-producing E. coli as in his urine culture from the Endocrine Clinic. His abdomen CT scan showed two left renal abscesses at the upper and middle poles. His temperature resolved on the fourth day of IV therapy. Intravenous meropenem was continued for 4 weeks after inserting PICC line and the patient was followed up by home healthcare. He was feeling better with occasional left flank pain and repeated abdomen CT scan showed complete resolution of both renal abscesses. PMID:28018690

  12. Advanced renal disease, end-stage renal disease and renal death among HIV-positive individuals in Europe

    Directory of Open Access Journals (Sweden)

    Ryom L

    2012-11-01

    failure (1, cardiovascular disease (1, pancreatitis (1 and unknown causes (3. The ARD/ESRD/renal death incidence was low in this population with the available FU, and was associated with traditional and HIV-related risk factors. Most persons with ARD/ESRD/renal death had pre-existing renal impairment, but some experienced a rapid progression from initial normal levels. Prognosis after ARD/ESRD was poor. Larger studies are required to address the possible contribution of specific antiretrovirals.

  13. The expression of EPOR in renal cortex during postnatal development.

    Directory of Open Access Journals (Sweden)

    Lu Xiao

    Full Text Available Erythropoietin (EPO, known for its role in erythroid differentiation, has been shown to be an important growth factor for brain and heart. EPO is synthesized by fibroblast-like cells in the renal cortex. Prompted by this anatomical relationship and its significant impact on the maturation process of brain and heart, we asked whether EPO could play a role during the development of renal cortex. The relationship between the development of renal cortex and the change of EPO receptor (EPOR, through which EPO could act as a renotropic cytokine, became interesting to us. In this study, the day of birth was recorded as postnatal day 0(P0. P7, P14, P21, P28, P35, P42 and mature mice (postnatal days>56 were used as the animal model of different developmental stages. Immunohistochemistry and Western blotting were used to detect the expression of EPOR in mouse renal cortex. Results showed that expression of EPOR decreased with the development of renal cortex and became stable when kidney became mature. The expression of EPOR was detected at the renal tubule of all developmental stages and a relatively higher expression was observed at P14. However, at the renal corpuscle the expression was only observed at P7 and quickly became undetectable after that. All these suggested that a translocation of EPOR from renal corpuscle to renal tubule may take place during the developmental process of renal cortex. Also, EPO may be an essential element for the maturation of renal cortex, and the requirement for EPO was changed during postnatal development process.

  14. Percutaneous renal tumour biopsy.

    Science.gov (United States)

    Delahunt, Brett; Samaratunga, Hemamali; Martignoni, Guido; Srigley, John R; Evans, Andrew J; Brunelli, Matteo

    2014-09-01

    The use of percutaneous renal tumour biopsy (RTB) as a diagnostic tool for the histological characterization of renal masses has increased dramatically within the last 30 years. This increased utilization has paralleled advances in imaging techniques and an evolving knowledge of the clinical value of nephron sparing surgery. Improved biopsy techniques using image guidance, coupled with the use of smaller gauge needles has led to a decrease in complication rates. Reports from series containing a large number of cases have shown the non-diagnostic rate of RTB to range from 4% to 21%. Re-biopsy has been shown to reduce this rate, while the use of molecular markers further improves diagnostic sensitivity. In parallel with refinements of the biopsy procedure, there has been a rapid expansion in our understanding of the complexity of renal cell neoplasia. The 2013 Vancouver Classification is the current classification for renal tumours, and contains five additional entities recognized as novel forms of renal malignancy. The diagnosis of tumour morphotype on RTB is usually achievable on routine histology; however, immunohistochemical studies may be of assistance in difficult cases. The morphology of the main tumour subtypes, based upon the Vancouver Classification, is described and differentiating features are discussed.

  15. Can renal infarction occur after renal cyst aspiration? Case report.

    Science.gov (United States)

    Emre, Habib; Soyoral, Yasemin Usul; Tanik, Serhat; Gecit, Ilhan; Begenik, Huseyin; Pirincci, Necip; Erkoc, Reha

    2011-01-01

    Renal infarction (RI) is a rarely seen disorder, and the diagnosis is often missed. The two major causes of RI are thromboemboli originhating from a thrombus in the heart or aorta, and in-situ thrombosis of a renal artery. We report a case of RI that developed due to renal artery and vein thrombosis, as confirmed by pathological evaluation of the nephrectomy material, three weeks after renal cyst aspiration.

  16. Spatial coexistence of American beech and sugar maple regeneration in post-harvest northern hardwood forests

    OpenAIRE

    Nelson, Andrew S.; Wagner, Robert G.

    2014-01-01

    International audience; & Context Fine scale regeneration patterns of coexistent spe-cies are influenced by regeneration mechanisms and microsite requirements. Spatial patterns may be either disjunct or over-lapping, which will determine competitive effects and microsite dominance, and future forest composition. & Aims Using American beech (Fagus grandifolia Ehrh.) and sugar maple (Acer saccharum Marshall) as an example, three hypotheses were tested: (1) random beech spatial patterns, (2) clu...

  17. New ZnO-Based Regenerable Sulfur Sorbents for Fluid-Bed/Transport Reactor Applications

    Energy Technology Data Exchange (ETDEWEB)

    Slimane, R.B.; Lau, F.S.; Abbasian, J.; Ho, K.H.

    2002-09-19

    The overall objective of the ongoing sorbent development work at GTI is the advancement to the demonstration stage of a promising ZnO-TiO2 sulfur sorbent that has been developed under DCCA/ICCI and DOE/NETL sponsorship. This regenerable sorbent has been shown to possess an exceptional combination of excellent chemical reactivity, high effective capacity for sulfur absorption, high resistance to attrition, and regenerability at temperatures lower than required by typical zinc titanates.

  18. Extracellular matrix scaffolds as a platform for kidney regeneration.

    Science.gov (United States)

    Peloso, Andrea; Tamburrini, Riccardo; Edgar, Lauren; Wilm, Bettina; Katari, Ravi; Perin, Laura; Murray, Patricia; Orlando, Giuseppe

    2016-11-05

    Chronic and end stage renal disease (ESRD) have reached pandemic levels and pose a substantial public health burden. Unfortunately, available therapies lack efficacy in preventing progression to its end stage phase. Regenerative medicine promises to restore function of diseased organs among which the kidney, through two possible approaches: firstly, the maximization of the innate ability of tissues to repair or regenerate following injury; secondly, the ex vivo bio-fabrication of the organ in question. When regenerative medicine is applied to the setting of chronic or ESRD, it is intuitive that endeavors to improve renal repair, promote nephrogenesis in damaged kidneys, or the de novo engineering of transplantable kidneys, could have a major impact on the current management of this pandemic. Among the different regenerative medicine technologies currently under development, cell-on-scaffold seeding technology (CSST) - involving cells seeded throughout supporting scaffold structures made from biomaterials - is the most favorable candidate in the context of realistic clinical application. In this review, we outline and describe current investigations taking place in the field of CSST as it pertains to the restoration of kidney function.

  19. Transcriptional regulators in the Hippo signaling pathway control organ growth in Xenopus tadpole tail regeneration.

    Science.gov (United States)

    Hayashi, Shinichi; Ochi, Haruki; Ogino, Hajime; Kawasumi, Aiko; Kamei, Yasuhiro; Tamura, Koji; Yokoyama, Hitoshi

    2014-12-01

    The size and shape of tissues are tightly controlled by synchronized processes among cells and tissues to produce an integrated organ. The Hippo signaling pathway controls both cell proliferation and apoptosis by dual signal-transduction states regulated through a repressive kinase cascade. Yap1 and Tead, transcriptional regulators that act downstream of the Hippo signaling kinase cascade, have essential roles in regulating cell proliferation. In amphibian limb or tail regeneration, the local tissue outgrowth terminates when the correct size is reached, suggesting that organ size is strictly controlled during epimorphic organ-level regeneration. We recently demonstrated that Yap1 is required for the regeneration of Xenopus tadpole limb buds (Hayashi et al., 2014, Dev. Biol. 388, 57-67), but the molecular link between the Hippo pathway and organ size control in vertebrate epimorphic regeneration is not fully understood. To examine the requirement of Hippo pathway transcriptional regulators in epimorphic regeneration, including organ size control, we inhibited these regulators during Xenopus tadpole tail regeneration by overexpressing a dominant-negative form of Yap (dnYap) or Tead4 (dnTead4) under a heat-shock promoter in transgenic animal lines. Each inhibition resulted in regeneration defects accompanied by reduced cell mitosis and increased apoptosis. Single-cell gene manipulation experiments indicated that Tead4 cell-autonomously regulates the survival of neural progenitor cells in the regenerating tail. In amphibians, amputation at the proximal level of the tail (deep amputation) results in faster regeneration than that at the distal level (shallow amputation), to restore the original-sized tail with similar timing. However, dnTead4 overexpression abolished the position-dependent differential growth rate of tail regeneration. These results suggest that the transcriptional regulators in the Hippo pathway, Tead4 and Yap1, are required for general vertebrate

  20. Dendrite Injury Triggers DLK-Independent Regeneration

    Directory of Open Access Journals (Sweden)

    Michelle C. Stone

    2014-01-01

    Full Text Available Axon injury triggers regeneration through activation of a conserved kinase cascade, which includes the dual leucine zipper kinase (DLK. Although dendrites are damaged during stroke, traumatic brain injury, and seizure, it is not known whether mature neurons monitor dendrite injury and initiate regeneration. We probed the response to dendrite damage using model Drosophila neurons. Two larval neuron types regrew dendrites in distinct ways after all dendrites were removed. Dendrite regeneration was also triggered by injury in adults. Next, we tested whether dendrite injury was initiated with the same machinery as axon injury. Surprisingly, DLK, JNK, and fos were dispensable for dendrite regeneration. Moreover, this MAP kinase pathway was not activated by injury to dendrites. Thus, neurons respond to dendrite damage and initiate regeneration without using the conserved DLK cascade that triggers axon regeneration.

  1. Imaging chronic renal disease and renal transplant in children

    Energy Technology Data Exchange (ETDEWEB)

    Carmichael, Jim; Easty, Marina [Great Ormond Street Hospital, Radiology Department, London (United Kingdom)

    2010-06-15

    At Great Ormond Street Hospital we have the highest number of paediatric renal transplant patients in Europe, taking cases from across the United Kingdom and abroad. Our caseload includes many children with rare complicating medical problems and chronic renal failure related morbidity. This review aims to provide an overview of our experience of imaging children with chronic renal failure and transplants. (orig.)

  2. Renal sympathetic denervation: MDCT evaluation of the renal arteries.

    LENUS (Irish Health Repository)

    Hutchinson, Barry D

    2013-08-01

    Percutaneous transluminal renal sympathetic denervation is a new treatment of refractory systemic hypertension. The purpose of this study was to assess the clinical utility of MDCT to evaluate the anatomic configuration of the renal arteries in the context of renal sympathetic denervation.

  3. Screening renal stone formers for distal renal tubular acidosis

    DEFF Research Database (Denmark)

    Osther, P J; Hansen, A B; Røhl, H F

    1989-01-01

    A group of 110 consecutive renal stone formers were screened for distal renal tubular acidosis (RTA) using morning fasting urinary pH (mfUpH) levels followed by a short ammonium chloride loading test in patients with levels above 6.0. In 14 patients (12.7%) a renal acidification defect was noted...

  4. Salvage of bilateral renal artery occlusion after endovascular aneurysm repair with open splenorenal bypass

    Directory of Open Access Journals (Sweden)

    Samuel Jessula, MDCM

    2017-09-01

    Full Text Available We report renal salvage maneuvers after accidental bilateral renal artery coverage during endovascular aneurysm repair of an infrarenal abdominal aortic aneurysm. A 79-year-old man with an infrarenal abdominal aortic aneurysm was treated with endovascular aneurysm repair. Completion angiography demonstrated coverage of the renal arteries. Several revascularization techniques were attempted, including endograft repositioning and endovascular stenting through the femoral and brachial approach. The patient eventually underwent open splenorenal bypass with a Y Gore-Tex graft (W. L. Gore & Associates, Flagstaff, Ariz. After 3 months, computed tomography showed no evidence of endoleak and patent renal arteries. Renal function was well maintained, and the patient did not require dialysis.

  5. Renal Cell Carcinoma in A Patient with Kartagener Syndrome: First Case Report in English Language

    Directory of Open Access Journals (Sweden)

    Erkin Sağlam

    2015-03-01

    Full Text Available Cardiac and pulmonary anomalies are common among patients with situs inversus totalis. Renal anomalies, including renal agenesis, dysplasia, hypoplasia, ectopia, polycystic kidney, and horseshoe kidney have been reported. We report a case of renal cell carcinoma in a patient with situs inversus totalis (SIT. Our case represents the fourth case report of renal cell carcinoma in a patient with situs inversus totalis and to the best of our knowledge this is the first report in English language. Due to the higher frequency of cardiac, pulmonary, renal, and vascular anomalies the management of patients with situs inversus and urologic disease requires careful preoperative evaluation.

  6. Estimation of feline renal volume using computed tomography and ultrasound.

    Science.gov (United States)

    Tyson, Reid; Logsdon, Stacy A; Werre, Stephen R; Daniel, Gregory B

    2013-01-01

    Renal volume estimation is an important parameter for clinical evaluation of kidneys and research applications. A time efficient, repeatable, and accurate method for volume estimation is required. The purpose of this study was to describe the accuracy of ultrasound and computed tomography (CT) for estimating feline renal volume. Standardized ultrasound and CT scans were acquired for kidneys of 12 cadaver cats, in situ. Ultrasound and CT multiplanar reconstructions were used to record renal length measurements that were then used to calculate volume using the prolate ellipsoid formula for volume estimation. In addition, CT studies were reconstructed at 1 mm, 5 mm, and 1 cm, and transferred to a workstation where the renal volume was calculated using the voxel count method (hand drawn regions of interest). The reference standard kidney volume was then determined ex vivo using water displacement with the Archimedes' principle. Ultrasound measurement of renal length accounted for approximately 87% of the variability in renal volume for the study population. The prolate ellipsoid formula exhibited proportional bias and underestimated renal volume by a median of 18.9%. Computed tomography volume estimates using the voxel count method with hand-traced regions of interest provided the most accurate results, with increasing accuracy for smaller voxel sizes in grossly normal kidneys (-10.1 to 0.6%). Findings from this study supported the use of CT and the voxel count method for estimating feline renal volume in future clinical and research studies.

  7. Percutaneous Renal Biopsy : A Report of 200 Caces

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    M. Bahadori

    1966-01-01

    Full Text Available In the diffuse medical diseases of kidney, percutaneous renal biopsy is a valuable, safe and hazardless procedure. With the aid of this nearly new technique renal pathology, the natural history of renal diseases and the response of renal diseases to therapy, as well as the prognosis of renal disorders can be evaluated."nWe have analysed 210 percutaneous biopsies in Tehran. Complications were observed in 13% of cases, there is no mortality and no patient required drastic therapeutic intervention. Anuria, peri-renal colic and peri-renal hematoma were the only serious complications, which were seen in 4 patients, and were. readily controled with simple measures We obtained renal tissue in 95% cases of our patients and in 9 I% of them the tissue was adequate for c'ear diagnosis."nLike other authors, we believe that the procedure, when properly performed, can give a far more valuable informations about the patients without any realy dangerous risk.

  8. Renal injury, nephrolithiasis and Nigella sativa: A mini review

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    Parichehr Hayatdavoudi

    2016-01-01

    Full Text Available Objective: The incidence and prevalence of kidney stone is increasing worldwide. After the first recurrence the risk of subsequent relapses is higher and the time period between relapses is shortened. Urinary stones can be severely painful and make a huge economic burden. The stone disease may increase the vulnerability of patients to other diseases such as renal failure. Medicinal herbs are rich sources of antioxidants which are increasingly consumed globally for their safety, efficacy and low price. Nigella sativa is a spice plant that is widely used for prevention and treatment of many ailments in Muslim countries and worldwide. This review aims at investigation of the effects of Nigella sativa on renal injury and stone formation. Materials and Method: The scientific resources including PubMed, Scopus, and Google scholar were searched using key words such as: nephrolithiasis, urolithiasis, kidney/renal stone, renal injury, renal failure, urinary retention and black seed, black cumin, Nigella sativa and thymoquinone.    Results: N. sativa and its main component, thymoquinone showed positive effects in prevention or curing kidney stones and renal failure through various mechanism such as antioxidative, anti-inflammatory, anti-eicosanoid and immunomodulatory effects. The putative candidate in many cases has been claimed to be thymoquinone but it seems that at least in part, particularly in kidney stones, the herbal melanin plays a role which requires further investigation to prove. Conclusion: N. sativa and its components are beneficial in prevention and curing of renal diseases including nephrolithiasis and renal damages.

  9. Angioplasty and stent treatment of transplant renal artery stenosis.

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    Del Pozo, Maitane; Martí, Jordi; Guirado, Lluís; Facundo, Carme; Canal, Cristina; de la Torre, Pablo; Ballarín, José; Díaz, Joan M

    2012-07-17

    Transplant renal artery stenosis is a major complication that requires a therapeutic approach involving surgery or angioplasty. The aim of this study was to analyse the evolution of renal transplant patients with renal allograft artery stenosis treated by angioplasty and stent placement. Thirteen patients were diagnosed with transplant renal artery stenosis. Clinical suspicion was based on deterioration of renal function and/or poorly controlled hypertension with compatible Doppler ultrasound findings. The diagnosis was confirmed by arteriography, performing an angioplasty with stent placement during the same operation. A progressive improvement in renal function was observed during the first 3 months after the angioplasty, and renal function then remained stable over 2 years. In addition, blood pressure improved during the first 2 years, and as a consequence there was no need to increase the average number of anti-hypertensive drugs administered (2.5 drugs per patient). In conclusion, angioplasty with stent placement is a safe and effective procedure for the treatment of transplant renal artery stenosis.

  10. Malaria induced acute renal failure: A single center experience

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    Kanodia K

    2010-01-01

    Full Text Available Malaria has protean clinical manifestations and renal complications, particularly acute renal failure that could be life threatening. To evaluate the incidence, clinical profile, out-come and predictors of mortality in patients with malarial acute renal failure, we retrospectively studied the last two years records of malaria induced acute renal failure in patients with peripheral smear positive for malarial parasites. One hundred (10.4% (63 males, 37 females malaria induced acute renal failure amongst 958 cases of acute renal failure were evaluated. Plasmodium (P. falciparum was reported in 85%, P. vivax in 2%, and both in 13% patients. The mean serum creatinine was 9.2 ± 4.2 mg%, and oligo/anuria was present in 82%; 78% of the patients required hemodialysis. Sixty four percent of the patients recovered completely, 10% incompletely, and 5% developed chronic kidney failure; mortality occurred in 21% of the patients. Low hemoglobin, oligo/anuria on admission, hyperbilirubinemia, cerebral malaria, disseminated intravascular coa-gulation, and high serum creatinine were the main predictors of mortality. We conclude that ma-laria is associated with acute renal failure, which occurs most commonly in plasmodium falci-parum infected patients. Early diagnosis and prompt dialysis with supportive management can reduce morality and enhance recovery of renal function.

  11. Renal Cortical Lactate Dehydrogenase: A Useful, Accurate, Quantitative Marker of In Vivo Tubular Injury and Acute Renal Failure.

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    Richard A Zager

    Full Text Available Studies of experimental acute kidney injury (AKI are critically dependent on having precise methods for assessing the extent of tubular cell death. However, the most widely used techniques either provide indirect assessments (e.g., BUN, creatinine, suffer from the need for semi-quantitative grading (renal histology, or reflect the status of residual viable, not the number of lost, renal tubular cells (e.g., NGAL content. Lactate dehydrogenase (LDH release is a highly reliable test for assessing degrees of in vitro cell death. However, its utility as an in vivo AKI marker has not been defined. Towards this end, CD-1 mice were subjected to graded renal ischemia (0, 15, 22, 30, 40, or 60 min or to nephrotoxic (glycerol; maleate AKI. Sham operated mice, or mice with AKI in the absence of acute tubular necrosis (ureteral obstruction; endotoxemia, served as negative controls. Renal cortical LDH or NGAL levels were assayed 2 or 24 hrs later. Ischemic, glycerol, and maleate-induced AKI were each associated with striking, steep, inverse correlations (r, -0.89 between renal injury severity and renal LDH content. With severe AKI, >65% LDH declines were observed. Corresponding prompt plasma and urinary LDH increases were observed. These observations, coupled with the maintenance of normal cortical LDH mRNA levels, indicated the renal LDH efflux, not decreased LDH synthesis, caused the falling cortical LDH levels. Renal LDH content was well maintained with sham surgery, ureteral obstruction or endotoxemic AKI. In contrast to LDH, renal cortical NGAL levels did not correlate with AKI severity. In sum, the above results indicate that renal cortical LDH assay is a highly accurate quantitative technique for gauging the extent of experimental acute ischemic and toxic renal injury. That it avoids the limitations of more traditional AKI markers implies great potential utility in experimental studies that require precise quantitation of tubule cell death.

  12. Cell therapy in renal and cardiovascular disease Terapia celular en enfermedades renales y cardiovasculares

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    Juan Manuel Senior Sánchez

    2006-01-01

    Full Text Available Although there have been important advances in the field of molecular biology, the mechanisms responsible for nephrogenesis and the factors that modulate the process of development, proliferation, growth, and maturation during fetal and adult life have not been thoroughly explained. Animals, including mammals, share the intrinsic ability to regenerate tissues and organs as an important biological defense mechanism. In the case of the kidney, after tissue damage secondary to injury, anatomical and functional recovery of integrity is achieved, accompanied by the activation of a complex, poorly understood process, leading to the replacement of damaged tubular cells by functional ones that reorganize tubular architecture. This regeneration and repair process is produced by somatic, exogenous, adult stem cells, and probably by intrinsic renal stem cells, that are responsible for maintaining renal homeostasis Aunque se han logrado grandes avances en el campo de la biología molecular, todavía no se han esclarecido completamente los mecanismos responsables de la organogénesis y los factores que modulan el proceso de desarrollo, proliferación, crecimiento y maduración celulares durante la vida fetal y adulta. Los animales comparten la capacidad de regenerar tejidos y órganos, como un mecanismo biológico importante de defensa. En el caso del riñón, luego del daño tisular secundario a una noxa, se produce recuperación anatómica y funcional de la integridad, acompañada por la activación de un proceso sofisticado, mal comprendido, que lleva al reemplazo de las células tubulares dañadas por otras funcionalmente normales que reorganizan la arquitectura tubular. Este fenómeno de recambio se produce gracias a la presencia de células madre adultas somáticas exógenas, responsables del proceso de mantenimiento de la homeostasis renal, y posiblemente por células renales intrínsecas.

  13. Renal Tumor Biopsy Technique

    Institute of Scientific and Technical Information of China (English)

    Lei Zhang; Xue-Song Li; Li-Qun Zhou

    2016-01-01

    Objective:To review hot issues and future direction of renal tumor biopsy (RTB) technique.Data Sources:The literature concerning or including RTB technique in English was collected from PubMed published from 1990 to 2015.Study Selection:We included all the relevant articles on RTB technique in English,with no limitation of study design.Results:Computed tomography and ultrasound were usually used for guiding RTB with respective advantages.Core biopsy is more preferred over fine needle aspiration because of superior accuracy.A minimum of two good-quality cores for a single renal tumor is generally accepted.The use of coaxial guide is recommended.For biopsy location,sampling different regions including central and peripheral biopsies are recommended.Conclusion:In spite of some limitations,RTB technique is relatively mature to help optimize the treatment of renal tumors.

  14. Dyslipoproteinemia in renal transplantation.

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    Gunjotikar R

    1994-01-01

    Full Text Available Twenty-seven live related donor renal allograft recipients were evaluated for dyslipoproteinemia. Twenty-two patients received dual immunosuppression with prednisolone and azathioprine. Five patients received cyclosporin as well. Total cholesterol (Tch, triglycerides (TG, HDL cholesterol (HDLch, LDL cholesterol (LDLch and VLDL cholesterol (VLDLch levels were estimated. Fifteen (56% patients showed significant lipoprotein abnormalities. Renal allograft recipients showed significantly lower levels of Tch (p < 0.05 and LDLch (p < 0.05 and higher levels of TG (p < 0.005 and HDLch (p < 0.05. Diet and beta blockers did not influence lipoprotein levels. A significant negative correlation was noted between post-transplant duration and Tch, TG and VLDLch levels. Increased TG levels were associated with increase in weight and higher daily prednisolone dosage at the time of evaluation. The study confirms the existence of dyslipoproteinemia in renal allograft recipients.

  15. Growth factors and cytokines in acute renal failure.

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    Harris, R C

    1997-04-01

    The mammalian kidney is susceptible to injury by ischemia/reperfusion and toxins, and regeneration after injury is characterized by hyperplasia and recovery of the damaged epithelial cells that line the tubules. Locally produced growth factors may serve as mediators of nephrogenesis and differentiation during renal development and of renal regeneration after acute injury. In cultured cells, administration of one or a mixture of growth factors to quiescent cells will initiate progression through the cell cycle and cell division. In the adult kidney, cell division normally is very low, but will increase up to 10-fold after acute injury. In addition to proliferation after lethal injury, there also is cellular repair in cells that have undergone sublethal injury. Recent studies indicate that growth factors inhibit programmed cell death in response to acute injury. Growth factors also may initiate or promote protein and lipid biosynthesis and provide an intracellular milieu that promotes cellular repair. In addition to cellular repair, growth factors also may be involved in the re-establishment of cell-extracellular matrix and cell-cell integrity. Finally, growth factors may limit injury by decreasing the factors that induce damage. Increased local renal expression of growth factors in response to acute injury include heparin binding epidermal growth factor (HB-EGF), hepatocyte growth factor (HGF), insulin-like growth factor-I (IGF-I), transforming growth factor-beta, parathyroid hormone-related peptide, and acidic fibroblast growth factor. In a number of experimental models of acute renal injury, administration of exogenous growth factors has been shown to accelerate both structural and functional recovery. Specifically, EGF, IGF-1, and HGF all have been shown to be effective in this regard. These studies are reviewed and potential therapeutic uses of growth factors and cytokines will be discussed.

  16. Renal (Kidney) Manifestations in TSC

    Science.gov (United States)

    ... International TSC Research Conference Text Size Get Involved RENAL (KIDNEY) MANIFESTATIONS IN TSC Download a PDF of ... sclerosis complex (TSC) will develop some form of renal (kidney) disease during their lifetime. There are three ...

  17. Renal involvement in antiphospholipid syndrome.

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    Pons-Estel, Guillermo J; Cervera, Ricard

    2014-02-01

    Renal involvement can be a serious problem for patients with antiphospholipid syndrome (APS). However, this complication has been poorly recognized and studied. It can be present in patients who have either primary or systemic lupus erythematosus-associated APS. Clinical and laboratory features of renal involvement in APS include hypertension, hematuria, acute renal failure, and progressive chronic renal insufficiency with mild levels of proteinuria that can progress to nephrotic-range proteinuria. The main lesions are renal artery stenosis, venous renal thrombosis, and glomerular lesions (APS nephropathy) that may be acute (thrombotic microangiopathy) and/or chronic (arteriosclerosis, arterial fibrous intimal hyperplasia, tubular thyroidization, arteriolar occlusions, and focal cortical atrophy). APS can also cause end-stage renal disease and allograft vascular thrombosis. This article reviews the range of renal abnormalities associated with APS, and their diagnosis and treatment options.

  18. [Renal transplantation and urinary lithiasis].

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    Lechevallier, E; Saussine, C; Traxer, O

    2008-12-01

    Renal lithiasis in renal donors is rare. A renal stone in a donor, or in a renal transplant, is not a contraindication for harvesting nor transplantation. If possible, the stone must be removed at the time of the transplantation. The risk of lithiasis is increased in the renal transplant recipient, with a frequency of 2-6%. Metabolic abnormalities for lithiasis are frequent and can be induced by the immunosuppressive treatment, anticalcineurins. Lithiasis can have a poor prognosis in the renal recipient with a risk for infection or renal dysfunction. Small (renal transplant can be followed-up. Stones of 0.5-1.5cm need an extracorporeal lithotripsy with a previous safety JJ stent. Stones greater than 1.5cm can be treated by ureteroscopy or percutaneous surgery.

  19. REGENERATION OF Pimpinella pruatjan THROUGH SOMATIC EMBRYOGENESIS

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    I. Roostika

    2016-10-01

    Full Text Available Pruatjan (Pimpinella pruatjan Molk. is an Indonesian endangered plant which has various medicinal properties such as aphrodisiac, diuretic, and tonic. The plant is commonly harvested from its natural habitat, therefore it becomes endangered. Regeneration of pruatjan through organogenesis has been studied, but its shoot multiplication was very low (5 shoots per explant. The study aimed to investigate the best regeneration technique of pruatjan through somatic embryogenesis. This research was conducted at the tissue culture laboratory, Indonesian Center for Agricultural Biotechnology and Genetic Resources Research and Development in 2004-2005. Callus formation of pruatjan was induced from the petioles and leaves in Driver and Kuniyaki’s (DKW based medium containing 2,4-D combined with picloram at the level of 0.5, 1.0, 1.5, and 1.5 ppm. Embryogenic calli were then transferred into embryo development medium in two ways. First, they were directly transferred into media containing IBA/NAA at the level of 0.5, 1.0, and 1.5 ppm. Second, they were indirectly transferred into media containing 2.0 ppm 2,4-D and 0.3% casein hydrolysate prior to the IBA/ NAA media. Parameters evaluated were fresh weight, dry weight, time initiation of embryogenic callus formation, and total number of embryos. The result showed that calli of pruatjan were successfully induced from the petioles and leaves. The best calli were induced from the leaves in the DKW medium containing 2.0 ppm 2,4-D and 0.5 ppm picloram. Embryo development of the calli was best if they were first grown in the media containing 2.0 ppm 2,4-D and 0.3% casein hydrolysate then transferred to the IBA/NAA media. The total number of somatic embryos was counted up to 103 on the medium containing 1.5 ppm IBA. This study indicated that pruatjan somatic embryogenesis regeneration required three different media, i.e. for callus induction, development and maturation, and for

  20. Regeneration: the ultimate example of wound healing.

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    Murawala, Prayag; Tanaka, Elly M; Currie, Joshua D

    2012-12-01

    The outcome of wound repair in mammals is often characterized by fibrotic scaring. Vertebrates such as zebrafish, frogs, and salamanders not only heal scarlessly, but also can regenerate lost appendages. Decades of study on the process of animal regeneration has produced key insights into the mechanisms of how complex tissue is restored. By examining our current knowledge of regeneration, we can draw parallels with mammalian wound healing to identify the molecular determinants that produce such differing outcomes.