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Sample records for cardiac neural crest

  1. Conditional expression of Spry1 in neural crest causes craniofacial and cardiac defects

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    Spicer Douglas B

    2010-05-01

    Full Text Available Abstract Background Growth factors and their receptors are mediators of organogenesis and must be tightly regulated in a temporal and spatial manner for proper tissue morphogenesis. Intracellular regulators of growth factor signaling pathways provide an additional level of control. Members of the Sprouty family negatively regulate receptor tyrosine kinase pathways in several developmental contexts. To gain insight into the role of Spry1 in neural crest development, we analyzed the developmental effects of conditional expression of Spry1 in neural crest-derived tissues. Results Here we report that conditional expression of Spry1 in neural crest cells causes defects in craniofacial and cardiac development in mice. Spry1;Wnt1-Cre embryos die perinatally and exhibit facial clefting, cleft palate, cardiac and cranial nerve defects. These defects appear to be the result of decreased proliferation and increased apoptosis of neural crest and neural crest-derived cell populations. In addition, the domains of expression of several key transcription factors important to normal craniofacial and cardiac development including AP2, Msx2, Dlx5, and Dlx6 were reduced in Spry1;Wnt1-Cre transgenic embryos. Conclusion Collectively, these data suggest that Spry1 is an important regulator of craniofacial and cardiac morphogenesis and perturbations in Spry1 levels may contribute to congenital disorders involving tissues of neural crest origin.

  2. Meis2 is essential for cranial and cardiac neural crest development

    Czech Academy of Sciences Publication Activity Database

    Machoň, Ondřej; Mašek, Jan; Machoňová, Olga; Krauss, S.; Kozmik, Zbyněk

    2015-01-01

    Roč. 15, Nov 6 (2015). ISSN 1471-213X R&D Projects: GA ČR GAP305/12/2042; GA MŠk(CZ) LK11214 Institutional support: RVO:68378050 Keywords : Meis2 * Persistent truncus arteriosus * Neural crest * Craniofacial skeleton * Cranial nerves Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 2.667, year: 2014

  3. Pax7 lineage contributions to the mammalian neural crest.

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    Barbara Murdoch

    Full Text Available Neural crest cells are vertebrate-specific multipotent cells that contribute to a variety of tissues including the peripheral nervous system, melanocytes, and craniofacial bones and cartilage. Abnormal development of the neural crest is associated with several human maladies including cleft/lip palate, aggressive cancers such as melanoma and neuroblastoma, and rare syndromes, like Waardenburg syndrome, a complex disorder involving hearing loss and pigment defects. We previously identified the transcription factor Pax7 as an early marker, and required component for neural crest development in chick embryos. In mammals, Pax7 is also thought to play a role in neural crest development, yet the precise contribution of Pax7 progenitors to the neural crest lineage has not been determined.Here we use Cre/loxP technology in double transgenic mice to fate map the Pax7 lineage in neural crest derivates. We find that Pax7 descendants contribute to multiple tissues including the cranial, cardiac and trunk neural crest, which in the cranial cartilage form a distinct regional pattern. The Pax7 lineage, like the Pax3 lineage, is additionally detected in some non-neural crest tissues, including a subset of the epithelial cells in specific organs.These results demonstrate a previously unappreciated widespread distribution of Pax7 descendants within and beyond the neural crest. They shed light regarding the regionally distinct phenotypes observed in Pax3 and Pax7 mutants, and provide a unique perspective into the potential roles of Pax7 during disease and development.

  4. Neural crest migration: trailblazing ahead

    OpenAIRE

    Kulesa, Paul M.; McLennan, Rebecca

    2015-01-01

    Embryonic cell migration patterns are amazingly complex in the timing and spatial distribution of cells throughout the vertebrate landscape. However, advances in in vivo visualization, cell interrogation, and computational modeling are extracting critical features that underlie the mechanistic nature of these patterns. The focus of this review highlights recent advances in the study of the highly invasive neural crest cells and their migratory patterns during embryonic development. We discuss...

  5. The neural crest and neural crest cells: discovery and significance for theories of embryonic organization

    Indian Academy of Sciences (India)

    Brian K Hall

    2008-12-01

    The neural crest has long fascinated developmental biologists, and, increasingly over the past decades, evolutionary and evolutionary developmental biologists. The neural crest is the name given to the fold of ectoderm at the junction between neural and epidermal ectoderm in neurula-stage vertebrate embryos. In this sense, the neural crest is a morphological term akin to head fold or limb bud. This region of the dorsal neural tube consists of neural crest cells, a special population(s) of cell, that give rise to an astonishing number of cell types and to an equally astonishing number of tissues and organs. Neural crest cell contributions may be direct — providing cells — or indirect — providing a necessary, often inductive, environment in which other cells develop. The enormous range of cell types produced provides an important source of evidence of the neural crest as a germ layer, bringing the number of germ layers to four — ectoderm, endoderm, mesoderm, and neural crest. In this paper I provide a brief overview of the major phases of investigation into the neural crest and the major players involved, discuss how the origin of the neural crest relates to the origin of the nervous system in vertebrate embryos, discuss the impact on the germ-layer theory of the discovery of the neural crest and of secondary neurulation, and present evidence of the neural crest as the fourth germ layer. A companion paper (Hall, Evol. Biol. 2008) deals with the evolutionary origins of the neural crest and neural crest cells.

  6. FGF signaling transforms non-neural ectoderm into neural crest.

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    Yardley, Nathan; García-Castro, Martín I

    2012-12-15

    The neural crest arises at the border between the neural plate and the adjacent non-neural ectoderm. It has been suggested that both neural and non-neural ectoderm can contribute to the neural crest. Several studies have examined the molecular mechanisms that regulate neural crest induction in neuralized tissues or the neural plate border. Here, using the chick as a model system, we address the molecular mechanisms by which non-neural ectoderm generates neural crest. We report that in response to FGF the non-neural ectoderm can ectopically express several early neural crest markers (Pax7, Msx1, Dlx5, Sox9, FoxD3, Snail2, and Sox10). Importantly this response to FGF signaling can occur without inducing ectopic mesodermal tissues. Furthermore, the non-neural ectoderm responds to FGF by expressing the prospective neural marker Sox3, but it does not express definitive markers of neural or anterior neural (Sox2 and Otx2) tissues. These results suggest that the non-neural ectoderm can launch the neural crest program in the absence of mesoderm, without acquiring definitive neural character. Finally, we report that prior to the upregulation of these neural crest markers, the non-neural ectoderm upregulates both BMP and Wnt molecules in response to FGF. Our results provide the first effort to understand the molecular events leading to neural crest development via the non-neural ectoderm in amniotes and present a distinct response to FGF signaling. PMID:23000357

  7. Adrenergic innervation of the developing chick heart: neural crest ablations to produce sympathetically aneural hearts

    International Nuclear Information System (INIS)

    Ablation of various regions of premigratory trunk neural crest which gives rise to the sympathetic trunks was used to remove sympathetic cardiac innervation. Neuronal uptake of [3H]-norepinephrine was used as an index of neuronal development in the chick atrium. Following ablation of neural crest over somites 10-15 or 15-20, uptake was significantly decreased in the atrium at 16 and 17 days of development. Ablation of neural crest over somites 5-10 and 20-25 caused no decrease in [3H]-norepinephrine uptake. Removal of neural crest over somites 5-25 or 10-20 caused approximately equal depletions of [3H]-norepinephrine uptake in the atrium. Cardiac norepinephrine concentration was significantly depressed following ablation of neural crest over somites 5-25 but not over somites 10-20. Light-microscopic and histofluorescent preparations confirmed the absence of sympathetic trunks in the region of the normal origin of the sympathetic cardiac nerves following neural crest ablation over somites 10-20. The neural tube and dorsal root ganglia were damaged in the area of the neural-crest ablation; however, all of these structures were normal cranial and caudal to the lesioned area. Development of most of the embryos as well as the morphology of all of the hearts was normal following the lesion. These results indicate that it is possible to produce sympathetically aneural hearts by neural-crest ablation; however, sympathetic cardiac nerves account for an insignificant amount of cardiac norepinephrine

  8. Defective ALK5 signaling in the neural crest leads to increased postmigratory neural crest cell apoptosis and severe outflow tract defects

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    Sucov Henry M

    2006-11-01

    Full Text Available Abstract Background Congenital cardiovascular diseases are the most common form of birth defects in humans. A substantial portion of these defects has been associated with inappropriate induction, migration, differentiation and patterning of pluripotent cardiac neural crest stem cells. While TGF-β-superfamily signaling has been strongly implicated in neural crest cell development, the detailed molecular signaling mechanisms in vivo are still poorly understood. Results We deleted the TGF-β type I receptor Alk5 specifically in the mouse neural crest cell lineage. Failure in signaling via ALK5 leads to severe cardiovascular and pharyngeal defects, including inappropriate remodeling of pharyngeal arch arteries, abnormal aortic sac development, failure in pharyngeal organ migration and persistent truncus arteriosus. While ALK5 is not required for neural crest cell migration, our results demonstrate that it plays an important role in the survival of post-migratory cardiac neural crest cells. Conclusion Our results demonstrate that ALK5-mediated signaling in neural crest cells plays an essential cell-autonomous role in the pharyngeal and cardiac outflow tract development.

  9. Migrating into Genomics with the Neural Crest

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    Marianne E. Bronner

    2014-01-01

    Full Text Available Neural crest cells are a fascinating embryonic cell type, unique to vertebrates, which arise within the central nervous system but emigrate soon after its formation and migrate to numerous and sometimes distant locations in the periphery. Following their migratory phase, they differentiate into diverse derivatives ranging from peripheral neurons and glia to skin melanocytes and craniofacial cartilage and bone. The molecular underpinnings underlying initial induction of prospective neural crest cells at the neural plate border to their migration and differentiation have been modeled in the form of a putative gene regulatory network. This review describes experiments performed in my laboratory in the past few years aimed to test and elaborate this gene regulatory network from both an embryonic and evolutionary perspective. The rapid advances in genomic technology in the last decade have greatly expanded our knowledge of important transcriptional inputs and epigenetic influences on neural crest development. The results reveal new players and new connections in the neural crest gene regulatory network and suggest that it has an ancient origin at the base of the vertebrate tree.

  10. The origin and evolution of the neural crest

    OpenAIRE

    Donoghue, Philip C. J.; Graham, Anthony; Kelsh, Robert N.

    2008-01-01

    Many of the features that distinguish the vertebrates from other chordates are derived from the neural crest, and it has long been argued that the emergence of this multipotent embryonic population was a key innovation underpinning vertebrate evolution. More recently, however, a number of studies have suggested that the evolution of the neural crest was less sudden than previously believed. This has exposed the fact that neural crest, as evidenced by its repertoire of derivative cell types, h...

  11. Metabolic syndromes and neural crest development

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    A. Berio

    2011-01-01

    Full Text Available Aim of this study is to investigate for the possible connection between abnormal neural crest cell (NCC development and NCC-derived abnormal facial and cerebral structures in 3 children with pyruvate-dehydrogenase (PDH and in 10 cases with oxidative phosphorylation deficiency diagnosed from the Author by standard laboratory assays [i.e. 3 cases of Kearns-Sayre syndrome (KSS, 2 cases of Leigh syndrome, 1 case of KSS with De Toni-Debrè-Fanconi and rachitis (Berio disease, 1 case of KSS with aortic insuffiency and sub-aortic septum hyperthophy, 3 cases of chronic progressive external ophthalmoplegia]. There patients presented with hyperlactacidemia, hyperpyruvicemia and facial abnormalities, similar to those observed in the fetal alcohol syndrome (a typical neurocristopathy due to PDH deficiency, down-regulating NCC genes. The Author hypothesizes that the metabolic defect of scarce energy production is responsible of abnormal NCC proliferation/migration and consequent facial abnormalities.

  12. Current perspectives of the signaling pathways directing neural crest induction

    OpenAIRE

    Stuhlmiller, Timothy J.; García-Castro, Martín I.

    2012-01-01

    The neural crest is a migratory population of embryonic cells with a tremendous potential to differentiate and contribute to nearly every organ system in the adult body. Over the past two decades, an incredible amount of research has given us a reasonable understanding of how these cells are generated. Neural crest induction involves the combinatorial input of multiple signaling pathways and transcription factors, and is thought to occur in two phases from gastrulation to neurulation. In the ...

  13. Negative chemotaxis does not control quail neural crest cell dispersion.

    Science.gov (United States)

    Erickson, C A; Olivier, K R

    1983-04-01

    Negative chemotaxis has been proposed to direct dispersion of amphibian neural crest cells away from the neural tube (V. C. Twitty, 1949, Growth 13(Suppl. 9), 133-161). We have reexamined this hypothesis using quail neural crest and do not find evidence for it. When pigmented or freshly isolated neural crest cells are covered by glass shards to prevent diffusion of a "putative" chemotactic agent away from the cells and into the medium, we find a decrease in density of cells beneath the coverslip as did Twitty and Niu (1948, J. Exp. Zool. 108, 405-437). Unlike those investigators, however, we find the covered cells move slower than uncovered cells and that the decrease in density can be attributed to cessation of cell division and increased cell death in older cultures, rather than directed migration away from each other. In cell systems where negative chemotaxis has been demonstrated, a "no man's land" forms between two confronted explants (Oldfield, 1963, Exp. Cell Res. 30, 125-138). No such cell-free space forms between confronted neural crest explants, even if the explants are closely covered to prevent diffusion of the negative chemotactic material. If crest cell aggregates are drawn into capillary tubes to allow accumulation of the putative material, the cells disperse farther, the wider the capillary tube bore. This is contrary to what would be expected if dispersion depended on accumulation of this material. Also, no difference in dispersion is noted between cells in the center of the tubes versus cells near the mouth of the tubes where the tube medium is freely exchanging with external fresh medium. Alternative hypotheses for directionality of crest migration in vivo are discussed. PMID:6832483

  14. Current perspectives of the signaling pathways directing neural crest induction.

    Science.gov (United States)

    Stuhlmiller, Timothy J; García-Castro, Martín I

    2012-11-01

    The neural crest is a migratory population of embryonic cells with a tremendous potential to differentiate and contribute to nearly every organ system in the adult body. Over the past two decades, an incredible amount of research has given us a reasonable understanding of how these cells are generated. Neural crest induction involves the combinatorial input of multiple signaling pathways and transcription factors, and is thought to occur in two phases from gastrulation to neurulation. In the first phase, FGF and Wnt signaling induce NC progenitors at the border of the neural plate, activating the expression of members of the Msx, Pax, and Zic families, among others. In the second phase, BMP, Wnt, and Notch signaling maintain these progenitors and bring about the expression of definitive NC markers including Snail2, FoxD3, and Sox9/10. In recent years, additional signaling molecules and modulators of these pathways have been uncovered, creating an increasingly complex regulatory network. In this work, we provide a comprehensive review of the major signaling pathways that participate in neural crest induction, with a focus on recent developments and current perspectives. We provide a simplified model of early neural crest development and stress similarities and differences between four major model organisms: Xenopus, chick, zebrafish, and mouse. PMID:22547091

  15. Progenitors of the protochordate ocellus as an evolutionary origin of the neural crest

    OpenAIRE

    Ivashkin, Evgeniy; Adameyko, Igor

    2013-01-01

    The neural crest represents a highly multipotent population of embryonic stem cells found only in vertebrate embryos. Acquisition of the neural crest during the evolution of vertebrates was a great advantage, providing Chordata animals with the first cellular cartilage, bone, dentition, advanced nervous system and other innovations. Today not much is known about the evolutionary origin of neural crest cells. Here we propose a novel scenario in which the neural crest originates from neuroectod...

  16. Aebp2 as an epigenetic regulator for neural crest cells.

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    Hana Kim

    Full Text Available Aebp2 is a potential targeting protein for the mammalian Polycomb Repression Complex 2 (PRC2. We generated a mutant mouse line disrupting the transcription of Aebp2 to investigate its in vivo roles. Aebp2-mutant homozygotes were embryonic lethal while heterozygotes survived to adulthood with fertility. In developing mouse embryos, Aebp2 is expressed mainly within cells of neural crest origin. In addition, many heterozygotes display a set of phenotypes, enlarged colon and hypopigmentation, similar to those observed in human patients with Hirschsprung's disease and Waardenburg syndrome. These phenotypes are usually caused by the absence of the neural crest-derived ganglia in hindguts and melanocytes. ChIP analyses demonstrated that the majority of the genes involved in the migration and development process of neural crest cells are downstream target genes of AEBP2 and PRC2. Furthermore, expression analyses confirmed that some of these genes are indeed affected in the Aebp2 heterozygotes. Taken together, these results suggest that Aebp2 may regulate the migration and development of the neural crest cells through the PRC2-mediated epigenetic mechanism.

  17. Neural crest induction by paraxial mesoderm in Xenopus embryos requires FGF signals.

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    Monsoro-Burq, Anne-Hélène; Fletcher, Russell B; Harland, Richard M

    2003-07-01

    At the border of the neural plate, the induction of the neural crest can be achieved by interactions with the epidermis, or with the underlying mesoderm. Wnt signals are required for the inducing activity of the epidermis in chick and amphibian embryos. Here, we analyze the molecular mechanisms of neural crest induction by the mesoderm in Xenopus embryos. Using a recombination assay, we show that prospective paraxial mesoderm induces a panel of neural crest markers (Slug, FoxD3, Zic5 and Sox9), whereas the future axial mesoderm only induces a subset of these genes. This induction is blocked by a dominant negative (dn) form of FGFR1. However, neither dnFGFR4a nor inhibition of Wnt signaling prevents neural crest induction in this system. Among the FGFs, FGF8 is strongly expressed by the paraxial mesoderm. FGF8 is sufficient to induce the neural crest markers FoxD3, Sox9 and Zic5 transiently in the animal cap assay. In vivo, FGF8 injections also expand the Slug expression domain. This suggests that FGF8 can initiate neural crest formation and cooperates with other DLMZ-derived factors to maintain and complete neural crest induction. In contrast to Wnts, eFGF or bFGF, FGF8 elicits neural crest induction in the absence of mesoderm induction and without a requirement for BMP antagonists. In vivo, it is difficult to dissociate the roles of FGF and WNT factors in mesoderm induction and neural patterning. We show that, in most cases, effects on neural crest formation were parallel to altered mesoderm or neural development. However, neural and neural crest patterning can be dissociated experimentally using different dominant-negative manipulations: while Nfz8 blocks both posterior neural plate formation and neural crest formation, dnFGFR4a blocks neural patterning without blocking neural crest formation. These results suggest that different signal transduction mechanisms may be used in neural crest induction, and anteroposterior neural patterning. PMID:12783784

  18. Regeneration of neural crest derivatives in the Xenopus tadpole tail

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    Slack Jonathan MW

    2007-05-01

    Full Text Available Abstract Background After amputation of the Xenopus tadpole tail, a functionally competent new tail is regenerated. It contains spinal cord, notochord and muscle, each of which has previously been shown to derive from the corresponding tissue in the stump. The regeneration of the neural crest derivatives has not previously been examined and is described in this paper. Results Labelling of the spinal cord by electroporation, or by orthotopic grafting of transgenic tissue expressing GFP, shows that no cells emigrate from the spinal cord in the course of regeneration. There is very limited regeneration of the spinal ganglia, but new neurons as well as fibre tracts do appear in the regenerated spinal cord and the regenerated tail also contains abundant peripheral innervation. The regenerated tail contains a normal density of melanophores. Cell labelling experiments show that melanophores do not arise from the spinal cord during regeneration, nor from the mesenchymal tissues of the skin, but they do arise by activation and proliferation of pre-existing melanophore precursors. If tails are prepared lacking melanophores, then the regenerates also lack them. Conclusion On regeneration there is no induction of a new neural crest similar to that seen in embryonic development. However there is some regeneration of neural crest derivatives. Abundant melanophores are regenerated from unpigmented precursors, and, although spinal ganglia are not regenerated, sufficient sensory systems are produced to enable essential functions to continue.

  19. Development of teeth in chick embryos after mouse neural crest transplantations

    OpenAIRE

    Mitsiadis, Thimios A.; Chéraud, Yvonnick; Sharpe, Paul; Fontaine-Pérus, Josiane

    2003-01-01

    Teeth were lost in birds 70–80 million years ago. Current thinking holds that it is the avian cranial neural crest-derived mesenchyme that has lost odontogenic capacity, whereas the oral epithelium retains the signaling properties required to induce odontogenesis. To investigate the odontogenic capacity of ectomesenchyme, we have used neural tube transplantations from mice to chick embryos to replace the chick neural crest cell populations with mouse neural crest cells. The mouse/chick ...

  20. New genes in the evolution of the neural crest differentiation program

    OpenAIRE

    Martínez-Morales, Juan Ramón; Henrich, Thorsten; Ramialison, Mirana; Wittbrodt, Joachim

    2007-01-01

    BACKGROUND: Development of the vertebrate head depends on the multipotency and migratory behavior of neural crest derivatives. This cell population is considered a vertebrate innovation and, accordingly, chordate ancestors lacked neural crest counterparts. The identification of neural crest specification genes expressed in the neural plate of basal chordates, in addition to the discovery of pigmented migratory cells in ascidians, has challenged this hypothesis. These new findings revive th...

  1. The neural crest stem cells: control of neural crest cell fate and plasticity by endothelin-3

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    ELISABETH DUPIN

    2001-12-01

    Full Text Available How the considerable diversity of neural crest (NC-derived cell types arises in the vertebrate embryo has long been a key question in developmental biology. The pluripotency and plasticity of differentiation of the NC cell population has been fully documented and it is well-established that environmental cues play an important role in patterning the NC derivatives throughout the body. Over the past decade, in vivo and in vitro cellular approaches have unravelled the differentiation potentialities of single NC cells and led to the discovery of NC stem cells. Although it is clear that the final fate of individual cells is in agreement with their final position within the embryo, it has to be stressed that the NC cells that reach target sites are pluripotent and further restrictions occur only late in development. It is therefore a heterogenous collection of cells that is submitted to local environmental signals in the various NC-derived structures. Several factors were thus identified which favor the development of subsets of NC-derived cells in vitro. Moreover, the strategy of gene targeting in mouse has led at identifying new molecules able to control one or several aspects of NC cell differentiation in vivo. Endothelin peptides (and endothelin receptors are among those. The conjunction of recent data obtained in mouse and avian embryos and reviewed here contributes to a better understanding of the action of the endothelin signaling pathway in the emergence and stability of NC-derived cell phenotypes.O modo como a diversidade dos tipos celulares derivados da crista neural (CN surge, no embrião de vertebrado, tem sido uma pergunta chave na biologia do desenvolvimento. A pluripotência e a plasticidade na diferenciação da população de células da CN têm sido intensivamente documentadas, ficando deste modo estabelecido que os factores ambientais têm um papel importante na correta diferenciação dos derivados da CN no organismo. Na d

  2. Neural crest and placode contributions to olfactory development.

    Science.gov (United States)

    Suzuki, Jun; Osumi, Noriko

    2015-01-01

    Olfaction is the sense of smell that influences many primitive behaviors for survival, e.g., feeding, reproduction, social interaction, and fear response. The olfactory system is an evolutionarily ancient sensory system and composed of the olfactory epithelium (OE), the olfactory bulb (OB), and the olfactory cortex. The OE gives rise to olfactory receptor neurons (ORNs), i.e., primary sensory receptor cells whose axons project directly to the OB. The ORNs are unique in the way that they are continuously replaced during physiological turnover or following injury throughout life. In the OE, horizontal basal cells, i.e., flat and quiescent cells attached to the basal lamina, are now thought to be tissue stem cells. Although OE cells, especially ORNs, were hypothesized to be derived from the olfactory placode (OP), recent genetic fate-mapping studies using Cre reporter mice indicate a dual origin, i.e., the OP and neural crest (NC), of the olfactory system. The NC is a transient embryonic tissue that is formed between the dorsal neuroepithelium and epidermis. Neural crest cells (NCCs) are multipotent cells that migrate into various target tissues and differentiate into various cell types, including neurons and glia of the peripheral nervous system, cranial cartilage and bone, and melanocytes. Recent studies have revealed that neural crest-derived cells (NCDCs) are widely distributed in adult tissues, and that a subset of NCDCs still possesses NCC-like multipotency. Here, we review classical and recent studies of the olfactory system, especially focusing on the contribution of the NC and OP to the OE development. PMID:25662265

  3. Deletion of integrin-linked kinase from neural crest cells in mice results in aortic aneurysms and embryonic lethality

    OpenAIRE

    Arnold, Thomas D.; Keling Zang; Ainara Vallejo-Illarramendi

    2013-01-01

    SUMMARY Neural crest cells (NCCs) participate in the remodeling of the cardiac outflow tract and pharyngeal arch arteries during cardiovascular development. Integrin-linked kinase (ILK) is a serine/threonine kinase and a major regulator of integrin signaling. It links integrins to the actin cytoskeleton and recruits other adaptor molecules into a large complex to regulate actin dynamics and integrin function. Using the Cre-lox system, we deleted Ilk from NCCs of mice to investigate its rol...

  4. How Tissue Mechanical Properties Affect Enteric Neural Crest Cell Migration

    Science.gov (United States)

    Chevalier, N. R.; Gazguez, E.; Bidault, L.; Guilbert, T.; Vias, C.; Vian, E.; Watanabe, Y.; Muller, L.; Germain, S.; Bondurand, N.; Dufour, S.; Fleury, V.

    2016-02-01

    Neural crest cells (NCCs) are a population of multipotent cells that migrate extensively during vertebrate development. Alterations to neural crest ontogenesis cause several diseases, including cancers and congenital defects, such as Hirschprung disease, which results from incomplete colonization of the colon by enteric NCCs (ENCCs). We investigated the influence of the stiffness and structure of the environment on ENCC migration in vitro and during colonization of the gastrointestinal tract in chicken and mouse embryos. We showed using tensile stretching and atomic force microscopy (AFM) that the mesenchyme of the gut was initially soft but gradually stiffened during the period of ENCC colonization. Second-harmonic generation (SHG) microscopy revealed that this stiffening was associated with a gradual organization and enrichment of collagen fibers in the developing gut. Ex-vivo 2D cell migration assays showed that ENCCs migrated on substrates with very low levels of stiffness. In 3D collagen gels, the speed of the ENCC migratory front decreased with increasing gel stiffness, whereas no correlation was found between porosity and ENCC migration behavior. Metalloprotease inhibition experiments showed that ENCCs actively degraded collagen in order to progress. These results shed light on the role of the mechanical properties of tissues in ENCC migration during development.

  5. Identification and dissection of a key enhancer mediating cranial neural crest specific expression of transcription factor, Ets-1

    OpenAIRE

    Barembaum, Meyer; Bronner, Marianne E.

    2013-01-01

    Neural crest cells form diverse derivatives that vary according to their level of origin along the body axis, with only cranial neural crest cells contributing to facial skeleton. Interestingly, the transcription factor Ets-1 is uniquely expressed in cranial but not trunk neural crest, where it functions as a direct input into neural crest specifier genes, Sox10 and FoxD3. We have isolated and interrogated a cis-regulatory element, conserved between birds and mammals, that drives reporter exp...

  6. File list: NoD.PSC.10.AllAg.hESC_derived_neural_crests [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available NoD.PSC.10.AllAg.hESC_derived_neural_crests hg19 No description Pluripotent stem cell hESC derived... neural crests http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/assembled/NoD.PSC.10.AllAg.hESC_derived_neural_crests.bed ...

  7. File list: InP.PSC.10.AllAg.hESC_derived_neural_crests [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available InP.PSC.10.AllAg.hESC_derived_neural_crests hg19 Input control Pluripotent stem cell hESC derived... neural crests SRX1091573,SRX059369,SRX059361 http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/assembled/InP.PSC.10.AllAg.hESC_derived_neural_crests.bed ...

  8. File list: Unc.PSC.20.AllAg.hESC_derived_neural_crests [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Unc.PSC.20.AllAg.hESC_derived_neural_crests hg19 Unclassified Pluripotent stem cell hESC derived... neural crests SRX059366 http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/assembled/Unc.PSC.20.AllAg.hESC_derived_neural_crests.bed ...

  9. File list: NoD.PSC.05.AllAg.hESC_derived_neural_crests [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available NoD.PSC.05.AllAg.hESC_derived_neural_crests hg19 No description Pluripotent stem cell hESC derived... neural crests http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/assembled/NoD.PSC.05.AllAg.hESC_derived_neural_crests.bed ...

  10. Changes in cholinergic parameters associated with failure of conotruncal septation in embryonic chick hearts after neural crest ablation

    International Nuclear Information System (INIS)

    Cells from the neural crest over occipital somites migrate to the heart, where they give rise to parasympathetic postganglionic neurons as well as ectomesenchymal elements which contribute to conotruncal septation. With a microcautery needle, the neural crest over occipital somites was ablated bilaterally in chicken embryos at an early stage of development. Histological examination on incubation day 15 revealed conotruncal malformations, involving malformation or absence of the conotruncal septum in all embryos. Two peaks of embryo mortality were observed. One peak (incubation days 6-8) occurred at the same time as conotruncal septal closure; the second peak (incubation days 11-13) was concurrent with the onset of functional parasympathetic innervation. A disruption of parasympathetic innervation was indicated by: (1) a decrease in acetylcholinesterase staining, (2) a decrease (27%) in the number of ganglion cells in the conotruncus, (3) decreases in the acetylcholine content of atrium (31%) and ventricle (39%), and (4) a decrease (21%) in muscarinic acetylcholine receptor density on incubation day 15. Radiolabeled ligand-binding studies revealed no change in the affinity of cardiac muscarinic receptors for [3H]methylscopolamine (K/sub D/ . 0.17-0.21 nM). Agonist-binding affinity and sensitivity to guanine nucleotides were similarly unaffected. The reasons for the limited extent of the parasympathetic lesion are unclear, but may involve recruitment of precursor cells from other regions of the neural crest, partial regeneration of the neural crest following surgical removal, or an alteration in the contribution of incoming sympathetic or preganglionic parasympathetic elements. No such plasticity was associated with neural crest contributions to the structural development of the conotruncus. Malformations were observed in all lesioned embryos

  11. Identification of dividing, determined sensory neuron precursors in the mammalian neural crest

    OpenAIRE

    Greenwood, Amy L.; Turner, Eric E.; Anderson, David J.

    1999-01-01

    Sensory and autonomic neurons of the vertebrate peripheral nervous system are derived from the neural crest. Here we use the expression of lineage-specific transcription factors as a means to identify neuronal subtypes that develop in rat neural crest cultures grown in a defined medium. Sensory neurons, identified by expression of the POU-domain transcription factor Brn-3.0, develop from dividing precursors that differentiate within 2 days following emigration from the neural tube. Most of th...

  12. Tcf7l1 protects the anterior neural fold from adopting the neural crest fate.

    Science.gov (United States)

    Mašek, Jan; Machoň, Ondřej; Kořínek, Vladimír; Taketo, M Mark; Kozmik, Zbyněk

    2016-06-15

    The neural crest (NC) is crucial for the evolutionary diversification of vertebrates. NC cells are induced at the neural plate border by the coordinated action of several signaling pathways, including Wnt/β-catenin. NC cells are normally generated in the posterior neural plate border, whereas the anterior neural fold is devoid of NC cells. Using the mouse model, we show here that active repression of Wnt/β-catenin signaling is required for maintenance of neuroepithelial identity in the anterior neural fold and for inhibition of NC induction. Conditional inactivation of Tcf7l1, a transcriptional repressor of Wnt target genes, leads to aberrant activation of Wnt/β-catenin signaling in the anterior neuroectoderm and its conversion into NC. This reduces the developing prosencephalon without affecting the anterior-posterior neural character. Thus, Tcf7l1 defines the border between the NC and the prospective forebrain via restriction of the Wnt/β-catenin signaling gradient. PMID:27302397

  13. Adipose stromal cells contain phenotypically distinct adipogenic progenitors derived from neural crest.

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    Yoshihiro Sowa

    Full Text Available Recent studies have shown that adipose-derived stromal/stem cells (ASCs contain phenotypically and functionally heterogeneous subpopulations of cells, but their developmental origin and their relative differentiation potential remain elusive. In the present study, we aimed at investigating how and to what extent the neural crest contributes to ASCs using Cre-loxP-mediated fate mapping. ASCs harvested from subcutaneous fat depots of either adult P0-Cre/or Wnt1-Cre/Floxed-reporter mice contained a few neural crest-derived ASCs (NCDASCs. This subpopulation of cells was successfully expanded in vitro under standard culture conditions and their growth rate was comparable to non-neural crest derivatives. Although NCDASCs were positive for several mesenchymal stem cell markers as non-neural crest derivatives, they exhibited a unique bipolar or multipolar morphology with higher expression of markers for both neural crest progenitors (p75NTR, Nestin, and Sox2 and preadipocytes (CD24, CD34, S100, Pref-1, GATA2, and C/EBP-delta. NCDASCs were able to differentiate into adipocytes with high efficiency but their osteogenic and chondrogenic potential was markedly attenuated, indicating their commitment to adipogenesis. In vivo, a very small proportion of adipocytes were originated from the neural crest. In addition, p75NTR-positive neural crest-derived cells were identified along the vessels within the subcutaneous adipose tissue, but they were negative for mural and endothelial markers. These results demonstrate that ASCs contain neural crest-derived adipocyte-restricted progenitors whose phenotype is distinct from that of non-neural crest derivatives.

  14. Neural crest does not contribute to the neck and shoulder in the axolotl (Ambystoma mexicanum.

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    Hans-Henning Epperlein

    Full Text Available BACKGROUND: A major step during the evolution of tetrapods was their transition from water to land. This process involved the reduction or complete loss of the dermal bones that made up connections to the skull and a concomitant enlargement of the endochondral shoulder girdle. In the mouse the latter is derived from three separate embryonic sources: lateral plate mesoderm, somites, and neural crest. The neural crest was suggested to sustain the muscle attachments. How this complex composition of the endochondral shoulder girdle arose during evolution and whether it is shared by all tetrapods is unknown. Salamanders that lack dermal bone within their shoulder girdle were of special interest for a possible contribution of the neural crest to the endochondral elements and muscle attachment sites, and we therefore studied them in this context. RESULTS: We grafted neural crest from GFP+ fluorescent transgenic axolotl (Ambystoma mexicanum donor embryos into white (d/d axolotl hosts and followed the presence of neural crest cells within the cartilage of the shoulder girdle and the connective tissue of muscle attachment sites of the neck-shoulder region. Strikingly, neural crest cells did not contribute to any part of the endochondral shoulder girdle or to the connective tissue at muscle attachment sites in axolotl. CONCLUSIONS: Our results in axolotl suggest that neural crest does not serve a general function in vertebrate shoulder muscle attachment sites as predicted by the "muscle scaffold theory," and that it is not necessary to maintain connectivity of the endochondral shoulder girdle to the skull. Our data support the possibility that the contribution of the neural crest to the endochondral shoulder girdle, which is observed in the mouse, arose de novo in mammals as a developmental basis for their skeletal synapomorphies. This further supports the hypothesis of an increased neural crest diversification during vertebrate evolution.

  15. Elk3 is essential for the progression from progenitor to definitive neural crest cell.

    Science.gov (United States)

    Rogers, Crystal D; Phillips, Jacquelyn L; Bronner, Marianne E

    2013-02-15

    Elk3/Net/Sap2 (here referred to as Elk3) is an Ets ternary complex transcriptional repressor known for its involvement in angiogenesis during embryonic development. Although Elk3 is expressed in various tissues, additional roles for the protein outside of vasculature development have yet to be reported. Here, we characterize the early spatiotemporal expression pattern of Elk3 in the avian embryo using whole mount in situ hybridization and quantitative RT-PCR and examine the effects of its loss of function on neural crest development. At early stages, Elk3 is expressed in the head folds, head mesenchyme, intersomitic vessels, and migratory cranial neural crest (NC) cells. Loss of the Elk3 protein results in the retention of Pax7+ precursors in the dorsal neural tube that fail to upregulate neural crest specifier genes, FoxD3, Sox10 and Snail2, resulting in embryos with severe migration defects. The results putatively place Elk3 downstream of neural plate border genes, but upstream of neural crest specifier genes in the neural crest gene regulatory network (NC-GRN), suggesting that it is critical for the progression from progenitor to definitive neural crest cell. PMID:23266330

  16. Induction of cranial and posterior trunk neural crest by exogenous retinoic acid in zebrafish

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Retinoic acid (RA) plays an important role in development of vertebrate embryos. We demonstrate impacts of exogenous RA on the formation of neural crest cells in zebrafish using specific neural crest markers sox9b and crestin. Treatment with all-trans RA at 10?7 mmol/L at 50% epiboly induces sox9b expression in the forebrain and crestin expression in the forebrain and midbrain, resulting in significant increase of pigment cells in the head derived from the cranial neural crest. In addition, RA treatment induces expression of sox9b and crestin in the caudal marginal cells of the neuroectoderm during early segmentation. Earlier commitment of these cells to the neural crest fate in the posterior margins leads to abnormal development of the posterior body, probably by preventing mingling of ventral derived and dorsal-derived cells during the formation of the tailbud.

  17. Dissecting early regulatory relationships in the lamprey neural crest gene network.

    Science.gov (United States)

    Nikitina, Natalya; Sauka-Spengler, Tatjana; Bronner-Fraser, Marianne

    2008-12-23

    The neural crest, a multipotent embryonic cell type, originates at the border between neural and nonneural ectoderm. After neural tube closure, these cells undergo an epithelial-mesenchymal transition, migrate to precise, often distant locations, and differentiate into diverse derivatives. Analyses of expression and function of signaling and transcription factors in higher vertebrates has led to the proposal that a neural crest gene regulatory network (NC-GRN) orchestrates neural crest formation. Here, we interrogate the NC-GRN in the lamprey, taking advantage of its slow development and basal phylogenetic position to resolve early inductive events, 1 regulatory step at the time. To establish regulatory relationships at the neural plate border, we assess relative expression of 6 neural crest network genes and effects of individually perturbing each on the remaining 5. The results refine an upstream portion of the NC-GRN and reveal unexpected order and linkages therein; e.g., lamprey AP-2 appears to function early as a neural plate border rather than a neural crest specifier and in a pathway linked to MsxA but independent of ZicA. These findings provide an ancestral framework for performing comparative tests in higher vertebrates in which network linkages may be more difficult to resolve because of their rapid development. PMID:19104059

  18. Isolation and characterization of neural crest-derived stem cells from dental pulp of neonatal mice.

    Directory of Open Access Journals (Sweden)

    Kajohnkiart Janebodin

    Full Text Available Dental pulp stem cells (DPSCs are shown to reside within the tooth and play an important role in dentin regeneration. DPSCs were first isolated and characterized from human teeth and most studies have focused on using this adult stem cell for clinical applications. However, mouse DPSCs have not been well characterized and their origin(s have not yet been elucidated. Herein we examined if murine DPSCs are neural crest derived and determined their in vitro and in vivo capacity. DPSCs from neonatal murine tooth pulp expressed embryonic stem cell and neural crest related genes, but lacked expression of mesodermal genes. Cells isolated from the Wnt1-Cre/R26R-LacZ model, a reporter of neural crest-derived tissues, indicated that DPSCs were Wnt1-marked and therefore of neural crest origin. Clonal DPSCs showed multi-differentiation in neural crest lineage for odontoblasts, chondrocytes, adipocytes, neurons, and smooth muscles. Following in vivo subcutaneous transplantation with hydroxyapatite/tricalcium phosphate, based on tissue/cell morphology and specific antibody staining, the clones differentiated into odontoblast-like cells and produced dentin-like structure. Conversely, bone marrow stromal cells (BMSCs gave rise to osteoblast-like cells and generated bone-like structure. Interestingly, the capillary distribution in the DPSC transplants showed close proximity to odontoblasts whereas in the BMSC transplants bone condensations were distant to capillaries resembling dentinogenesis in the former vs. osteogenesis in the latter. Thus we demonstrate the existence of neural crest-derived DPSCs with differentiation capacity into cranial mesenchymal tissues and other neural crest-derived tissues. In turn, DPSCs hold promise as a source for regenerating cranial mesenchyme and other neural crest derived tissues.

  19. Ets-1 confers cranial features on neural crest delamination.

    Directory of Open Access Journals (Sweden)

    Eric Théveneau

    Full Text Available Neural crest cells (NCC have the particularity to invade the environment where they differentiate after separation from the neuroepithelium. This process, called delamination, is strikingly different between cranial and trunk NCCs. If signalings controlling slow trunk delamination start being deciphered, mechanisms leading to massive and rapid cranial outflow are poorly documented. Here, we show that the chick cranial NCCs delamination is the result of two events: a substantial cell mobilization and an epithelium to mesenchyme transition (EMT. We demonstrate that ets-1, a transcription factor specifically expressed in cranial NCCs, is responsible for the former event by recruiting massively cranial premigratory NCCs independently of the S-phase of the cell cycle and by leading the gathered cells to straddle the basal lamina. However, it does not promote the EMT process alone but can cooperate with snail-2 (previously called slug to this event. Altogether, these data lead us to propose that ets-1 plays a pivotal role in conferring specific cephalic characteristics on NCC delamination.

  20. Substrate-mediated reprogramming of human fibroblasts into neural crest stem-like cells and their applications in neural repair.

    Science.gov (United States)

    Tseng, Ting-Chen; Hsieh, Fu-Yu; Dai, Niann-Tzyy; Hsu, Shan-Hui

    2016-09-01

    Cell- and gene-based therapies have emerged as promising strategies for treating neurological diseases. The sources of neural stem cells are limited while the induced pluripotent stem (iPS) cells have risk of tumor formation. Here, we proposed the generation of self-renewable, multipotent, and neural lineage-related neural crest stem-like cells by chitosan substrate-mediated gene transfer of a single factor forkhead box D3 (FOXD3) for the use in neural repair. A simple, non-toxic, substrate-mediated method was applied to deliver the naked FOXD3 plasmid into human fibroblasts. The transfection of FOXD3 increased cell proliferation and up-regulated the neural crest marker genes (FOXD3, SOX2, and CD271), stemness marker genes (OCT4, NANOG, and SOX2), and neural lineage-related genes (Nestin, β-tubulin and GFAP). The expression levels of stemness marker genes and neural crest maker genes in the FOXD3-transfected fibroblasts were maintained until the fifth passage. The FOXD3 reprogrammed fibroblasts based on the new method significantly rescued the neural function of the impaired zebrafish. The chitosan substrate-mediated delivery of naked plasmid showed feasibility in reprogramming somatic cells. Particularly, the FOXD3 reprogrammed fibroblasts hold promise as an easily accessible cellular source with neural crest stem-like behavior for treating neural diseases in the future. PMID:27341268

  1. Skeletogenic fate of zebrafish cranial and trunk neural crest.

    Directory of Open Access Journals (Sweden)

    Erika Kague

    Full Text Available The neural crest (NC is a major contributor to the vertebrate craniofacial skeleton, detailed in model organisms through embryological and genetic approaches, most notably in chick and mouse. Despite many similarities between these rather distant species, there are also distinct differences in the contribution of the NC, particularly to the calvariae of the skull. Lack of information about other vertebrate groups precludes an understanding of the evolutionary significance of these differences. Study of zebrafish craniofacial development has contributed substantially to understanding of cartilage and bone formation in teleosts, but there is currently little information on NC contribution to the zebrafish skeleton. Here, we employ a two-transgene system based on Cre recombinase to genetically label NC in the zebrafish. We demonstrate NC contribution to cells in the cranial ganglia and peripheral nervous system known to be NC-derived, as well as to a subset of myocardial cells. The indelible labeling also enables us to determine NC contribution to late-forming bones, including the calvariae. We confirm suspected NC origin of cartilage and bones of the viscerocranium, including cartilages such as the hyosymplectic and its replacement bones (hymandibula and symplectic and membranous bones such as the opercle. The cleithrum develops at the border of NC and mesoderm, and as an ancestral component of the pectoral girdle was predicted to be a hybrid bone composed of both NC and mesoderm tissues. However, we find no evidence of a NC contribution to the cleithrum. Similarly, in the vault of the skull, the parietal bones and the caudal portion of the frontal bones show no evidence of NC contribution. We also determine a NC origin for caudal fin lepidotrichia; the presumption is that these are derived from trunk NC, demonstrating that these cells have the ability to form bone during normal vertebrate development.

  2. Local increase level of chondroitin sulfate induces changes in the rhombencephalic neural crest migration.

    Science.gov (United States)

    Moro Balbás, J A; Gato, A; Alonso, M; Barbosa, E

    1998-03-01

    Numerous studies suggest that chondroitin sulfate proteoglycan (CSPG) inhibits neural crest cells (NCC) migration at the trunk level. However, its action on the cephalic neural crest is not clear. To determine this action, we have microinjected 0.5 nl of different concentrations of chondroitin sulfate (CS) at the anterior rhombencephalon level in 9 stage chick embryos, as well as subgerminally administering beta-D-xyloside to 8 stage chick embryos. Beta-D-xyloside disrupts CSPG synthesis, producing an increase in CS free chains in several embryonal anlages. Chondroitin sulfate microinjected embryos and beta-D xyloside treated embryos were reincubated until attaining 12 stage. Results obtained for both experimental groups were similar. Immunoreactivity with HNK-1 antibody revealed that NCC did not migrate, remaining near the rhombencephalon dorsal wall; in addition, several NCC did not separate from the neural fold, becoming invaginated towards the rhombencephalon cavity. Our findings indicate that an increase in CS free chains in cephalic neural crest migratory routes not only disrupts their migration, but also impedes delamination and detachment of the rhombencephalic neuroepithelium NCC. These data suggest that the inhibitory action upon the neural crest migration attributed to CSPG may rest on its glycosaminoglycan (GAG). We cannot, however, rule out the possibility that increases in other GAGs apart from CS, may produce similar effects on neural crest migration. PMID:9551866

  3. The SWI/SNF BAF-A complex is essential for neural crest development.

    Science.gov (United States)

    Chandler, Ronald L; Magnuson, Terry

    2016-03-01

    Growing evidence indicates that chromatin remodeler mutations underlie the pathogenesis of human neurocristopathies or disorders that affect neural crest cells (NCCs). However, causal relationships among chromatin remodeler subunit mutations and NCC defects remain poorly understood. Here we show that homozygous loss of ARID1A-containing, SWI/SNF chromatin remodeling complexes (BAF-A) in NCCs results in embryonic lethality in mice, with mutant embryos succumbing to heart defects. Strikingly, monoallelic loss of ARID1A in NCCs led to craniofacial defects in adult mice, including shortened snouts and low set ears, and these defects were more pronounced following homozygous loss of ARID1A, with the ventral cranial bones being greatly reduced in size. Early NCC specification and expression of the BRG1 NCC target gene, PLEXINA2, occurred normally in the absence of ARID1A. Nonetheless, mutant embryos displayed incomplete conotruncal septation of the cardiac outflow tract and defects in the posterior pharyngeal arteries, culminating in persistent truncus arteriosus and agenesis of the ductus arteriosus. Consistent with this, migrating cardiac NCCs underwent apoptosis within the circumpharyngeal ridge. Our data support the notion that multiple, distinct chromatin remodeling complexes govern genetically separable events in NCC development and highlight a potential pathogenic role for NCCs in the human BAF complex disorder, Coffin-Siris Syndrome. PMID:26806701

  4. Signi fi cance of Neural Crest in Tooth Development: The Molecular Signature

    Directory of Open Access Journals (Sweden)

    VP Jayasekharan

    2014-07-01

    Full Text Available The neural crest originates from cells located along the lateral margins of the neural plate. Neural crest cells arise as the result of an inductive action by the non-neural ectoderm adjacent to the neural plate and possibly by nearby mesoderm as well. As the neural tube forms, a group of cells separate from the neuro- ectoderm. These cells have the capacity to migrate and differen- tiate extensively within the developing embryo and they are the basis of structures such as spinal sensory ganglia, sympathetic neurons, Schwann cells, pigment cells and meninges. Speci fi c interactions occur during the development of tooth and recent research has concentrated more on the molecular aspects of these interactions. Thus, it is highly imperative to understand and digress the complex mechanisms involved in these processes

  5. Neural crest stem cell population in craniomaxillofacial development and tissue repair

    Directory of Open Access Journals (Sweden)

    M La Noce

    2014-10-01

    Full Text Available Neural crest cells, delaminating from the neural tube during migration, undergo an epithelial-mesenchymal transition and differentiate into several cell types strongly reinforcing the mesoderm of the craniofacial body area – giving rise to bone, cartilage and other tissues and cells of this human body area. Recent studies on craniomaxillofacial neural crest-derived cells have provided evidence for the tremendous plasticity of these cells. Actually, neural crest cells can respond and adapt to the environment in which they migrate and the cranial mesoderm plays an important role toward patterning the identity of the migrating neural crest cells. In our experience, neural crest-derived stem cells, such as dental pulp stem cells, can actively proliferate, repair bone and give rise to other tissues and cytotypes, including blood vessels, smooth muscle, adipocytes and melanocytes, highlighting that their use in tissue engineering is successful. In this review, we provide an overview of the main pathways involved in neural crest formation, delamination, migration and differentiation; and, in particular, we concentrate our attention on the translatability of the latest scientific progress. Here we try to suggest new ideas and strategies that are needed to fully develop the clinical use of these cells. This effort should involve both researchers/clinicians and improvements in good manufacturing practice procedures. It is important to address studies towards clinical application or take into consideration that studies must have an effective therapeutic prospect for humans. New approaches and ideas must be concentrated also toward stem cell recruitment and activation within the human body, overcoming the classical grafting.

  6. Williams Syndrome Transcription Factor is critical for neural crest cell function in Xenopus laevis

    Science.gov (United States)

    Barnett, Chris; Yazgan, Oya; Kuo, Hui-Ching; Malakar, Sreepurna; Thomas, Trevor; Fitzgerald, Amanda; Harbour, Billy; Henry, Jonathan J.; Krebs, Jocelyn E.

    2012-01-01

    Williams Syndrome Transcription Factor (WSTF) is one of ~25 haplodeficient genes in patients with the complex developmental disorder Williams Syndrome (WS). WS results in visual/spatial processing defects, cognitive impairment, unique behavioral phenotypes, characteristic “elfin” facial features, low muscle tone and heart defects. WSTF exists in several chromatin remodeling complexes and has roles in transcription, replication, and repair. Chromatin remodeling is essential during embryogenesis, but WSTF’s role in vertebrate development is poorly characterized. To investigate the developmental role of WSTF, we knocked down WSTF in Xenopus laevis embryos using a morpholino that targets WSTF mRNA. BMP4 shows markedly increased and spatially aberrant expression in WSTF-deficient embryos, while SHH, MRF4, PAX2, EPHA4 and SOX2 expression are severely reduced, coupled with defects in a number of developing embryonic structures and organs. WSTF-deficient embryos display defects in anterior neural development. Induction of the neural crest, measured by expression of the neural crest-specific genes SNAIL and SLUG, is unaffected by WSTF depletion. However, at subsequent stages WSTF knockdown results in a severe defect in neural crest migration and/or maintenance. Consistent with a maintenance defect, WSTF knockdowns display a specific pattern of increased apoptosis at the tailbud stage in regions corresponding to the path of cranial neural crest migration. Our work is the first to describe a role for WSTF in proper neural crest function, and suggests that neural crest defects resulting from WSTF haploinsufficiency may be a major contributor to the pathoembryology of WS. PMID:22691402

  7. Characterization of an individual neural crest-like cell lineage in the invertebrate chordate Ciona intestinalis

    OpenAIRE

    Cone, Angela C.

    2008-01-01

    During embryogenesis, all chordate embryos undergo neurulation to form a dorsal, hollow nerve cord. Neural crest cells (NCC), considered a vertebrate innovation, arise during neurulation and later differentiate into a multitude of tissues that account for much of the structural complexity that distinguishes craniates from invertebrate chordates [1, 2]. NCCs are induced and specified at the border of the neural and non-neural ectoderm by a complex network of inductive signals and transcription...

  8. [Progress in the study of syndromic hearing loss resulted from neural crest abnormalities].

    Science.gov (United States)

    Yalan, Liu; Hua, Zhang; Yong, Feng

    2014-11-01

    More than 400 types of syndromic hearing loss (SHL) have been reported so far, in which Waardenburg syndrome (WS), congenital microtia syndrome (CMS), and large vestibular aqueduct syndrome (LVAS) are the most common ones in clinic. However, it is difficult to study the genetic basis and pathogenesis of SHL in a systematical way because of the strong clinical and genetic heterogeneity of SHL. Dysfunction of neural crest cells (NCC), which are caused by the gene interaction network extended from SOX10 and PAX3, are relevant to the phenotype of WS, CMS and LVAS. Our previous study also confirmed that the gene network was involved in the pathogenesis of WS. In this review, we summarize research progress in the pathogenic mechanisms of SHL resulted from defects in neural crest decelopment, and provide the gene interaction network of neural crest abnormalities resulting in SHL, and hope to provide research ideas and theoretical basis for the systematical study on pathogenesis of common SHL. PMID:25567871

  9. Modeling Cerebrovascular Pathophysiology in Amyloid-β Metabolism using Neural-Crest-Derived Smooth Muscle Cells

    Directory of Open Access Journals (Sweden)

    Christine Cheung

    2014-10-01

    Full Text Available There is growing recognition of cerebrovascular contributions to neurodegenerative diseases. In the walls of cerebral arteries, amyloid-beta (Aβ accumulation is evident in a majority of aged people and patients with cerebral amyloid angiopathy. Here, we leverage human pluripotent stem cells to generate vascular smooth muscle cells (SMCs from neural crest progenitors, recapitulating brain-vasculature-specific attributes of Aβ metabolism. We confirm that the lipoprotein receptor, LRP1, functions in our neural-crest-derived SMCs to mediate Aβ uptake and intracellular lysosomal degradation. Hypoxia significantly compromises the contribution of SMCs to Aβ clearance by suppressing LRP1 expression. This enabled us to develop an assay of Aβ uptake by using the neural crest-derived SMCs with hypoxia as a stress paradigm. We then tested several vascular protective compounds in a high-throughput format, demonstrating the value of stem-cell-based phenotypic screening for novel therapeutics and drug repurposing, aimed at alleviating amyloid burden.

  10. Neural Crest Stem Cells from Dental Tissues: A New Hope for Dental and Neural Regeneration

    Directory of Open Access Journals (Sweden)

    Gaskon Ibarretxe

    2012-01-01

    Full Text Available Several stem cell sources persist in the adult human body, which opens the doors to both allogeneic and autologous cell therapies. Tooth tissues have proven to be a surprisingly rich and accessible source of neural crest-derived ectomesenchymal stem cells (EMSCs, which may be employed to repair disease-affected oral tissues in advanced regenerative dentistry. Additionally, one area of medicine that demands intensive research on new sources of stem cells is nervous system regeneration, since this constitutes a therapeutic hope for patients affected by highly invalidating conditions such as spinal cord injury, stroke, or neurodegenerative diseases. However, endogenous adult sources of neural stem cells present major drawbacks, such as their scarcity and complicated obtention. In this context, EMSCs from dental tissues emerge as good alternative candidates, since they are preserved in adult human individuals, and retain both high proliferation ability and a neural-like phenotype in vitro. In this paper, we discuss some important aspects of tissue regeneration by cell therapy and point out some advantages that EMSCs provide for dental and neural regeneration. We will finally review some of the latest research featuring experimental approaches and benefits of dental stem cell therapy.

  11. Wnt1 and BMP2: two factors recruiting multipotent neural crest progenitors isolated from adult bone marrow.

    Science.gov (United States)

    Glejzer, A; Laudet, E; Leprince, P; Hennuy, B; Poulet, C; Shakhova, O; Sommer, L; Rogister, B; Wislet-Gendebien, S

    2011-06-01

    Recent studies have shown that neural crest-derived progenitor cells can be found in diverse mammalian tissues including tissues that were not previously shown to contain neural crest derivatives, such as bone marrow. The identification of those "new" neural crest-derived progenitor cells opens new strategies for developing autologous cell replacement therapies in regenerative medicine. However, their potential use is still a challenge as only few neural crest-derived progenitor cells were found in those new accessible locations. In this study, we developed a protocol, based on wnt1 and BMP2 effects, to enrich neural crest-derived cells from adult bone marrow. Those two factors are known to maintain and stimulate the proliferation of embryonic neural crest stem cells, however, their effects have never been characterized on neural crest cells isolated from adult tissues. Using multiple strategies from microarray to 2D-DIGE proteomic analyses, we characterized those recruited neural crest-derived cells, defining their identity and their differentiating abilities. PMID:20976520

  12. File list: ALL.PSC.50.AllAg.hESC_derived_neural_crests [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available ALL.PSC.50.AllAg.hESC_derived_neural_crests hg19 All antigens Pluripotent stem cell hESC derived...X1091539,SRX059364 http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/assembled/ALL.PSC.50.AllAg.hESC_derived_neural_crests.bed ...

  13. File list: His.PSC.10.AllAg.hESC_derived_neural_crests [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available His.PSC.10.AllAg.hESC_derived_neural_crests hg19 Histone Pluripotent stem cell hESC derived...3,SRX1091531,SRX059364,SRX1091530 http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/assembled/His.PSC.10.AllAg.hESC_derived_neural_crests.bed ...

  14. File list: His.PSC.20.AllAg.hESC_derived_neural_crests [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available His.PSC.20.AllAg.hESC_derived_neural_crests hg19 Histone Pluripotent stem cell hESC derived...30,SRX059362,SRX1091539,SRX059364 http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/assembled/His.PSC.20.AllAg.hESC_derived_neural_crests.bed ...

  15. Synthesis on accumulation of putative neurotransmitters by cultured neural crest cells

    International Nuclear Information System (INIS)

    The events mediating the differentiation of embryonic neural crest cells into several types of neurons are incompletely understood. In order to probe one aspect of this differentiation, we have examined the capacity of cultured quail trunk neural crest cells to synthesize, from radioactive precursors, and store several putative neurotransmitter compounds. These neural crest cultures develop the capacity to synthesize and accumulate acetylcholine and the catecholamines norepinephrine and dopamine. In contrast, detectable but relatively little synthesis and accumulation of 5-hydroxytryptamine gamma-aminobutyric acid, or octopamine from the appropriate radiolabeled precursors were observed. The capacity for synthesis and accumulation of radiolabeled acetylcholine and catecholamines is very low or absent at 2 days in vitro. Between 3 and 7 days in vitro, there is a marked rise in both catecholamine and acetylcholine accumulation in the cultures. These findings suggest that, under the particular conditions used in these experiments, the development of neurotransmitter biosynthesis in trunk neural crest cells ijs restricted and resembles, at least partially, the pattern observed in vivo. The development of this capacity to synthesize and store radiolabeled acetylcholine and catecholamines from the appropriate radioactive precursors coincides closely with the development of the activities of the synthetic enzymes choline acetyltransferase and dopamine beta-hydroxylase reported by others

  16. Properties of Neural Crest-Like Cells Differentiated from Human Embryonic Stem Cells

    Czech Academy of Sciences Publication Activity Database

    Křivánek, J.; Švandová, Eva; Králik, J.; Hajda, S.; Fedr, Radek; Vinařský, V.; Jaroš, J.; Souček, Karel

    2014-01-01

    Roč. 60, č. 2014 (2014), s. 30-38. ISSN 0015-5500 R&D Projects: GA ČR(CZ) GAP304/11/1418 Institutional support: RVO:68081707 Keywords : stem cell differentiation * neural crest * odontogenesis Subject RIV: BO - Biophysics; ED - Physiology (UZFG-Y) Impact factor: 1.000, year: 2014

  17. Gene regulatory evolution and the origin of macroevolutionary novelties: insights from the neural crest

    OpenAIRE

    Van Otterloo, Eric; Robert A Cornell; Medeiros, Daniel Meulemans; Garnett, Aaron T.

    2013-01-01

    The appearance of novel anatomic structures during evolution is driven by changes to the networks of transcription factors, signaling pathways, and downstream effector genes controlling development. The nature of the changes to these developmental gene regulatory networks (GRNs) is poorly understood. A striking test case is the evolution of the GRN controlling development of the neural crest (NC). NC cells emerge from the neural plate border (NPB) and contribute to multiple adult structures. ...

  18. An FGF3-BMP Signaling Axis Regulates Caudal Neural Tube Closure, Neural Crest Specification and Anterior-Posterior Axis Extension

    Science.gov (United States)

    Anderson, Matthew J.; Schimmang, Thomas; Lewandoski, Mark

    2016-01-01

    During vertebrate axis extension, adjacent tissue layers undergo profound morphological changes: within the neuroepithelium, neural tube closure and neural crest formation are occurring, while within the paraxial mesoderm somites are segmenting from the presomitic mesoderm (PSM). Little is known about the signals between these tissues that regulate their coordinated morphogenesis. Here, we analyze the posterior axis truncation of mouse Fgf3 null homozygotes and demonstrate that the earliest role of PSM-derived FGF3 is to regulate BMP signals in the adjacent neuroepithelium. FGF3 loss causes elevated BMP signals leading to increased neuroepithelium proliferation, delay in neural tube closure and premature neural crest specification. We demonstrate that elevated BMP4 depletes PSM progenitors in vitro, phenocopying the Fgf3 mutant, suggesting that excessive BMP signals cause the Fgf3 axis defect. To test this in vivo we increased BMP signaling in Fgf3 mutants by removing one copy of Noggin, which encodes a BMP antagonist. In such mutants, all parameters of the Fgf3 phenotype were exacerbated: neural tube closure delay, premature neural crest specification, and premature axis termination. Conversely, genetically decreasing BMP signaling in Fgf3 mutants, via loss of BMP receptor activity, alleviates morphological defects. Aberrant apoptosis is observed in the Fgf3 mutant tailbud. However, we demonstrate that cell death does not cause the Fgf3 phenotype: blocking apoptosis via deletion of pro-apoptotic genes surprisingly increases all Fgf3 defects including causing spina bifida. We demonstrate that this counterintuitive consequence of blocking apoptosis is caused by the increased survival of BMP-producing cells in the neuroepithelium. Thus, we show that FGF3 in the caudal vertebrate embryo regulates BMP signaling in the neuroepithelium, which in turn regulates neural tube closure, neural crest specification and axis termination. Uncovering this FGF3-BMP signaling axis is

  19. An FGF3-BMP Signaling Axis Regulates Caudal Neural Tube Closure, Neural Crest Specification and Anterior-Posterior Axis Extension.

    Directory of Open Access Journals (Sweden)

    Matthew J Anderson

    2016-05-01

    Full Text Available During vertebrate axis extension, adjacent tissue layers undergo profound morphological changes: within the neuroepithelium, neural tube closure and neural crest formation are occurring, while within the paraxial mesoderm somites are segmenting from the presomitic mesoderm (PSM. Little is known about the signals between these tissues that regulate their coordinated morphogenesis. Here, we analyze the posterior axis truncation of mouse Fgf3 null homozygotes and demonstrate that the earliest role of PSM-derived FGF3 is to regulate BMP signals in the adjacent neuroepithelium. FGF3 loss causes elevated BMP signals leading to increased neuroepithelium proliferation, delay in neural tube closure and premature neural crest specification. We demonstrate that elevated BMP4 depletes PSM progenitors in vitro, phenocopying the Fgf3 mutant, suggesting that excessive BMP signals cause the Fgf3 axis defect. To test this in vivo we increased BMP signaling in Fgf3 mutants by removing one copy of Noggin, which encodes a BMP antagonist. In such mutants, all parameters of the Fgf3 phenotype were exacerbated: neural tube closure delay, premature neural crest specification, and premature axis termination. Conversely, genetically decreasing BMP signaling in Fgf3 mutants, via loss of BMP receptor activity, alleviates morphological defects. Aberrant apoptosis is observed in the Fgf3 mutant tailbud. However, we demonstrate that cell death does not cause the Fgf3 phenotype: blocking apoptosis via deletion of pro-apoptotic genes surprisingly increases all Fgf3 defects including causing spina bifida. We demonstrate that this counterintuitive consequence of blocking apoptosis is caused by the increased survival of BMP-producing cells in the neuroepithelium. Thus, we show that FGF3 in the caudal vertebrate embryo regulates BMP signaling in the neuroepithelium, which in turn regulates neural tube closure, neural crest specification and axis termination. Uncovering this FGF3

  20. miR-21 promotes the differentiation of hair follicle-derived neural crest stem cells into Schwann cells

    Institute of Scientific and Technical Information of China (English)

    Yuxin Ni; Kaizhi Zhang; Xuejuan Liu; Tingting Yang; Baixiang Wang; Li Fu; Lan A; Yanmin Zhou

    2014-01-01

    Hair follicle-derived neural crest stem cells can be induced to differentiate into Schwann cells in vivo and in vitro. However, the underlying regulatory mechanism during cell differentiation remains poorly understood. This study isolated neural crest stem cells from human hair folli-cles and induced them to differentiate into Schwann cells. Quantitative RT-PCR showed that microRNA (miR)-21 expression was gradually increased during the differentiation of neural crest stem cells into Schwann cells. After transfection with the miR-21 agonist (agomir-21), the differentiation capacity of neural crest stem cells was enhanced. By contrast, after transfection with the miR-21 antagonist (antagomir-21), the differentiation capacity was attenuated. Further study results showed that SOX-2 was an effective target of miR-21. Without compromising SOX2 mRNA expression, miR-21 can down-regulate SOX protein expression by binding to the 3′-UTR of miR-21 mRNA. Knocking out the SOX2 gene from the neural crest stem cells significantly reversed the antagomir-21 inhibition of neural crest stem cells differentiating into Schwann cells. The results suggest that miR-21 expression was increased during the differentiation of neural crest stem cells into Schwann cells and miR-21 promoted the differentiation through down-regu-lating SOX protein expression by binding to the 3′-UTR of SOX2 mRNA.

  1. CHD7, the gene mutated in CHARGE syndrome, regulates genes involved in neural crest cell guidance.

    Science.gov (United States)

    Schulz, Yvonne; Wehner, Peter; Opitz, Lennart; Salinas-Riester, Gabriela; Bongers, Ernie M H F; van Ravenswaaij-Arts, Conny M A; Wincent, Josephine; Schoumans, Jacqueline; Kohlhase, Jürgen; Borchers, Annette; Pauli, Silke

    2014-08-01

    Heterozygous loss of function mutations in CHD7 (chromodomain helicase DNA-binding protein 7) lead to CHARGE syndrome, a complex developmental disorder affecting craniofacial structures, cranial nerves and several organ systems. Recently, it was demonstrated that CHD7 is essential for the formation of multipotent migratory neural crest cells, which migrate from the neural tube to many regions of the embryo, where they differentiate into various tissues including craniofacial and heart structures. So far, only few CHD7 target genes involved in neural crest cell development have been identified and the role of CHD7 in neural crest cell guidance and the regulation of mesenchymal-epithelial transition are unknown. Therefore, we undertook a genome-wide microarray expression analysis on wild-type and CHD7 deficient (Chd7 (Whi/+) and Chd7 (Whi/Whi)) mouse embryos at day 9.5, a time point of neural crest cell migration. We identified 98 differentially expressed genes between wild-type and Chd7 (Whi/Whi) embryos. Interestingly, many misregulated genes are involved in neural crest cell and axon guidance such as semaphorins and ephrin receptors. By performing knockdown experiments for Chd7 in Xenopus laevis embryos, we found abnormalities in the expression pattern of Sema3a, a protein involved in the pathogenesis of Kallmann syndrome, in vivo. In addition, we detected non-synonymous SEMA3A variations in 3 out of 45 CHD7-negative CHARGE patients. In summary, we discovered for the first time that Chd7 regulates genes involved in neural crest cell guidance, demonstrating a new aspect in the pathogenesis of CHARGE syndrome. Furthermore, we showed for Sema3a a conserved regulatory mechanism across different species, highlighting its significance during development. Although we postulated that the non-synonymous SEMA3A variants which we found in CHD7-negative CHARGE patients alone are not sufficient to produce the phenotype, we suggest an important modifier role for SEMA3A in the

  2. Applications of Mesenchymal Stem Cells and Neural Crest Cells in Craniofacial Skeletal Research

    Directory of Open Access Journals (Sweden)

    Satoru Morikawa

    2016-01-01

    Full Text Available Craniofacial skeletal tissues are composed of tooth and bone, together with nerves and blood vessels. This composite material is mainly derived from neural crest cells (NCCs. The neural crest is transient embryonic tissue present during neural tube formation whose cells have high potential for migration and differentiation. Thus, NCCs are promising candidates for craniofacial tissue regeneration; however, the clinical application of NCCs is hindered by their limited accessibility. In contrast, mesenchymal stem cells (MSCs are easily accessible in adults, have similar potential for self-renewal, and can differentiate into skeletal tissues, including bones and cartilage. Therefore, MSCs may represent good sources of stem cells for clinical use. MSCs are classically identified under adherent culture conditions, leading to contamination with other cell lineages. Previous studies have identified mouse- and human-specific MSC subsets using cell surface markers. Additionally, some studies have shown that a subset of MSCs is closely related to neural crest derivatives and endothelial cells. These MSCs may be promising candidates for regeneration of craniofacial tissues from the perspective of developmental fate. Here, we review the fundamental biology of MSCs in craniofacial research.

  3. The positive transcriptional elongation factor (P-TEFb) is required for neural crest specification.

    Science.gov (United States)

    Hatch, Victoria L; Marin-Barba, Marta; Moxon, Simon; Ford, Christopher T; Ward, Nicole J; Tomlinson, Matthew L; Desanlis, Ines; Hendry, Adam E; Hontelez, Saartje; van Kruijsbergen, Ila; Veenstra, Gert Jan C; Münsterberg, Andrea E; Wheeler, Grant N

    2016-08-15

    Regulation of gene expression at the level of transcriptional elongation has been shown to be important in stem cells and tumour cells, but its role in the whole animal is only now being fully explored. Neural crest cells (NCCs) are a multipotent population of cells that migrate during early development from the dorsal neural tube throughout the embryo where they differentiate into a variety of cell types including pigment cells, cranio-facial skeleton and sensory neurons. Specification of NCCs is both spatially and temporally regulated during embryonic development. Here we show that components of the transcriptional elongation regulatory machinery, CDK9 and CYCLINT1 of the P-TEFb complex, are required to regulate neural crest specification. In particular, we show that expression of the proto-oncogene c-Myc and c-Myc responsive genes are affected. Our data suggest that P-TEFb is crucial to drive expression of c-Myc, which acts as a 'gate-keeper' for the correct temporal and spatial development of the neural crest. PMID:27343897

  4. Neural crest-mediated bone resorption is a determinant of species-specific jaw length

    OpenAIRE

    Ealba, Erin L.; Jheon, Andrew H.; Hall, Jane; Curantz, Camille; Butcher, Kristin D.; Schneider, Richard A

    2015-01-01

    Precise control of jaw length during development is crucial for proper form and function. Previously we have shown that in birds, neural crest mesenchyme (NCM) confers species-specific size and shape to the beak by regulating molecular and histological programs for the induction and deposition of cartilage and bone. Here we reveal that a hitherto unrecognized but similarly essential mechanism for establishing jaw length is the ability of NCM to mediate bone resorption. Osteoclasts are conside...

  5. Culture bag systems for clinical applications of adult human neural crest-derived stem cells

    OpenAIRE

    Greiner, Johannes F. W.; Grunwald, Lena-Marie; Müller, Janine; Sudhoff, Holger; Widera, Darius; Kaltschmidt, Christian; Kaltschmidt, Barbara

    2014-01-01

    Introduction Facing the challenging treatment of neurodegenerative diseases as well as complex craniofacial injuries such as those common after cancer therapy, the field of regenerative medicine increasingly relies on stem cell transplantation strategies. Here, neural crest-derived stem cells (NCSCs) offer many promising applications, although scale up of clinical-grade processes prior to potential transplantations is currently limiting. In this study, we aimed to establish a clinical-grad...

  6. Feeder-free Derivation of Neural Crest Progenitor Cells from Human Pluripotent Stem Cells

    OpenAIRE

    Zeltner, Nadja; Lafaille, Fabien G.; Fattahi, Faranak; Studer, Lorenz

    2014-01-01

    Human pluripotent stem cells (hPSCs) have great potential for studying human embryonic development, for modeling human diseases in the dish and as a source of transplantable cells for regenerative applications after disease or accidents. Neural crest (NC) cells are the precursors for a large variety of adult somatic cells, such as cells from the peripheral nervous system and glia, melanocytes and mesenchymal cells. They are a valuable source of cells to study aspects of human embryonic develo...

  7. Isolation and Characterization of Neural Crest-Derived Stem Cells from Dental Pulp of Neonatal Mice

    OpenAIRE

    Janebodin, Kajohnkiart; Horst, Orapin V; Ieronimakis, Nicholas; Balasundaram, Gayathri; Reesukumal, Kanit; Pratumvinit, Busadee; Reyes, Morayma

    2011-01-01

    Dental pulp stem cells (DPSCs) are shown to reside within the tooth and play an important role in dentin regeneration. DPSCs were first isolated and characterized from human teeth and most studies have focused on using this adult stem cell for clinical applications. However, mouse DPSCs have not been well characterized and their origin(s) have not yet been elucidated. Herein we examined if murine DPSCs are neural crest derived and determined their in vitro and in vivo capacity. DPSCs from neo...

  8. Adipose Stromal Cells Contain Phenotypically Distinct Adipogenic Progenitors Derived from Neural Crest

    OpenAIRE

    Yoshihiro Sowa; Tetsuya Imura; Toshiaki Numajiri; Kosuke Takeda; Yo Mabuchi; Yumi Matsuzaki; Kenichi Nishino

    2013-01-01

    Recent studies have shown that adipose-derived stromal/stem cells (ASCs) contain phenotypically and functionally heterogeneous subpopulations of cells, but their developmental origin and their relative differentiation potential remain elusive. In the present study, we aimed at investigating how and to what extent the neural crest contributes to ASCs using Cre-loxP-mediated fate mapping. ASCs harvested from subcutaneous fat depots of either adult P0-Cre/or Wnt1-Cre/Floxed-reporter mice contain...

  9. Analysis of neural crest-derived clones reveals novel aspects of facial development.

    Science.gov (United States)

    Kaucka, Marketa; Ivashkin, Evgeny; Gyllborg, Daniel; Zikmund, Tomas; Tesarova, Marketa; Kaiser, Jozef; Xie, Meng; Petersen, Julian; Pachnis, Vassilis; Nicolis, Silvia K; Yu, Tian; Sharpe, Paul; Arenas, Ernest; Brismar, Hjalmar; Blom, Hans; Clevers, Hans; Suter, Ueli; Chagin, Andrei S; Fried, Kaj; Hellander, Andreas; Adameyko, Igor

    2016-08-01

    Cranial neural crest cells populate the future facial region and produce ectomesenchyme-derived tissues, such as cartilage, bone, dermis, smooth muscle, adipocytes, and many others. However, the contribution of individual neural crest cells to certain facial locations and the general spatial clonal organization of the ectomesenchyme have not been determined. We investigated how neural crest cells give rise to clonally organized ectomesenchyme and how this early ectomesenchyme behaves during the developmental processes that shape the face. Using a combination of mouse and zebrafish models, we analyzed individual migration, cell crowd movement, oriented cell division, clonal spatial overlapping, and multilineage differentiation. The early face appears to be built from multiple spatially defined overlapping ectomesenchymal clones. During early face development, these clones remain oligopotent and generate various tissues in a given location. By combining clonal analysis, computer simulations, mouse mutants, and live imaging, we show that facial shaping results from an array of local cellular activities in the ectomesenchyme. These activities mostly involve oriented divisions and crowd movements of cells during morphogenetic events. Cellular behavior that can be recognized as individual cell migration is very limited and short-ranged and likely results from cellular mixing due to the proliferation activity of the tissue. These cellular mechanisms resemble the strategy behind limb bud morphogenesis, suggesting the possibility of common principles and deep homology between facial and limb outgrowth. PMID:27493992

  10. Induction of neural crest in Xenopus by transcription factor AP2α

    OpenAIRE

    Luo, Ting; Lee, Young-Hoon; Saint-Jeannet, Jean-Pierre; Sargent, Thomas D.

    2003-01-01

    We report experiments with Xenopus laevis, using both intact embryos and ectodermal explants, showing that the transcription factor AP2α is positively regulated by bone morphogenetic protein (BMP) and Wnt signaling, and that this activation is an essential step in the induction of neural crest (NC). Ectopic expression of AP2α is sufficient to activate high-level expression of NC-specific genes such as Slug and Sox9, which can occur as isolated domains within the neural plate as well as by exp...

  11. Lack of beta1 integrins in enteric neural crest cells leads to a Hirschsprung-like phenotype

    DEFF Research Database (Denmark)

    Breau, Marie A; Pietri, Thomas; Eder, Olivier;

    2006-01-01

    The enteric nervous system arises mainly from vagal and sacral neural crest cells that colonise the gut between 9.5 and 14 days of development in mice. Using the Cre-LoxP system, we removed beta1 integrins in the neural crest cells when they emerge from the neural tube. beta1-null enteric neural...... integrins are required for the villi innervation in the small intestine. Our findings highlight the crucial roles played by beta1 integrins at various steps of enteric nervous system development....

  12. Gene array analysis of neural crest cells identifies transcription factors necessary for direct conversion of embryonic fibroblasts into neural crest cells

    Directory of Open Access Journals (Sweden)

    Tsutomu Motohashi

    2016-03-01

    Full Text Available Neural crest cells (NC cells are multipotent cells that emerge from the edge of the neural folds and migrate throughout the developing embryo. Although the gene regulatory network for generation of NC cells has been elucidated in detail, it has not been revealed which of the factors in the network are pivotal to directing NC identity. In this study we analyzed the gene expression profile of a pure NC subpopulation isolated from Sox10-IRES-Venus mice and investigated whether these genes played a key role in the direct conversion of Sox10-IRES-Venus mouse embryonic fibroblasts (MEFs into NC cells. The comparative molecular profiles of NC cells and neural tube cells in 9.5-day embryos revealed genes including transcription factors selectively expressed in developing trunk NC cells. Among 25 NC cell-specific transcription factor genes tested, SOX10 and SOX9 were capable of converting MEFs into SOX10-positive (SOX10+ cells. The SOX10+ cells were then shown to differentiate into neurons, glial cells, smooth muscle cells, adipocytes and osteoblasts. These SOX10+ cells also showed limited self-renewal ability, suggesting that SOX10 and SOX9 directly converted MEFs into NC cells. Conversely, the remaining transcription factors, including well-known NC cell specifiers, were unable to convert MEFs into SOX10+ NC cells. These results suggest that SOX10 and SOX9 are the key factors necessary for the direct conversion of MEFs into NC cells.

  13. The F-box protein Cdc4/Fbxw7 is a novel regulator of neural crest development in Xenopus laevis

    Directory of Open Access Journals (Sweden)

    Hartley Rebecca S

    2010-01-01

    Full Text Available Abstract Background The neural crest is a unique population of cells that arise in the vertebrate ectoderm at the neural plate border after which they migrate extensively throughout the embryo, giving rise to a wide range of derivatives. A number of proteins involved in neural crest development have dynamic expression patterns, and it is becoming clear that ubiquitin-mediated protein degradation is partly responsible for this. Results Here we demonstrate a novel role for the F-box protein Cdc4/Fbxw7 in neural crest development. Two isoforms of Xenopus laevis Cdc4 were identified, and designated xCdc4α and xCdc4β. These are highly conserved with vertebrate Cdc4 orthologs, and the Xenopus proteins are functionally equivalent in terms of their ability to degrade Cyclin E, an established vertebrate Cdc4 target. Blocking xCdc4 function specifically inhibited neural crest development at an early stage, prior to expression of c-Myc, Snail2 and Snail. Conclusions We demonstrate that Cdc4, an ubiquitin E3 ligase subunit previously identified as targeting primarily cell cycle regulators for proteolysis, has additional roles in control of formation of the neural crest. Hence, we identify Cdc4 as a protein with separable but complementary functions in control of cell proliferation and differentiation.

  14. Canonical Wnt activity regulates trunk neural crest delamination linking BMP/noggin signaling with G1/S transition.

    Science.gov (United States)

    Burstyn-Cohen, Tal; Stanleigh, Jonathan; Sela-Donenfeld, Dalit; Kalcheim, Chaya

    2004-11-01

    Delamination of premigratory neural crest cells depends on a balance between BMP/noggin and on successful G1/S transition. Here, we report that BMP regulates G1/S transition and consequent crest delamination through canonical Wnt signaling. Noggin overexpression inhibits G1/S transition and blocking G1/S abrogates BMP-induced delamination; moreover, transcription of Wnt1 is stimulated by BMP and by the developing somites, which concomitantly inhibit noggin production. Interfering with beta-catenin and LEF/TCF inhibits G1/S transition, neural crest delamination and transcription of various BMP-dependent genes, which include Cad6B, Pax3 and Msx1, but not that of Slug, Sox9 or FoxD3. Hence, we propose that developing somites inhibit noggin transcription in the dorsal tube, resulting in activation of BMP and consequent Wnt1 production. Canonical Wnt signaling in turn stimulates G1/S transition and generation of neural crest cell motility independently of its proposed role in earlier neural crest specification. PMID:15456730

  15. High glucose environment inhibits cranial neural crest survival by activating excessive autophagy in the chick embryo

    Science.gov (United States)

    Wang, Xiao-Yu; Li, Shuai; Wang, Guang; Ma, Zheng-Lai; Chuai, Manli; Cao, Liu; Yang, Xuesong

    2015-01-01

    High glucose levels induced by maternal diabetes could lead to defects in neural crest development during embryogenesis, but the cellular mechanism is still not understood. In this study, we observed a defect in chick cranial skeleton, especially parietal bone development in the presence of high glucose levels, which is derived from cranial neural crest cells (CNCC). In early chick embryo, we found that inducing high glucose levels could inhibit the development of CNCC, however, cell proliferation was not significantly involved. Nevertheless, apoptotic CNCC increased in the presence of high levels of glucose. In addition, the expression of apoptosis and autophagy relevant genes were elevated by high glucose treatment. Next, the application of beads soaked in either an autophagy stimulator (Tunicamycin) or inhibitor (Hydroxychloroquine) functionally proved that autophagy was involved in regulating the production of CNCC in the presence of high glucose levels. Our observations suggest that the ERK pathway, rather than the mTOR pathway, most likely participates in mediating the autophagy induced by high glucose. Taken together, our observations indicated that exposure to high levels of glucose could inhibit the survival of CNCC by affecting cell apoptosis, which might result from the dysregulation of the autophagic process. PMID:26671447

  16. ADAM10 is essential for cranial neural crest-derived maxillofacial bone development.

    Science.gov (United States)

    Tan, Yu; Fu, Runqing; Liu, Jiaqiang; Wu, Yong; Wang, Bo; Jiang, Ning; Nie, Ping; Cao, Haifeng; Yang, Zhi; Fang, Bing

    2016-07-01

    Growth disorders of the craniofacial bones may lead to craniofacial deformities. The majority of maxillofacial bones are derived from cranial neural crest cells via intramembranous bone formation. Any interruption of the craniofacial skeleton development process might lead to craniofacial malformation. A disintegrin and metalloprotease (ADAM)10 plays an essential role in organ development and tissue integrity in different organs. However, little is known about its function in craniofacial bone formation. Therefore, we investigated the role of ADAM10 in the developing craniofacial skeleton, particularly during typical mandibular bone development. First, we showed that ADAM10 was expressed in a specific area of the craniofacial bone and that the expression pattern dynamically changed during normal mouse craniofacial development. Then, we crossed wnt1-cre transgenic mice with adam10-flox mice to generate ADAM10 conditional knockout mice. The stereomicroscopic, radiographic, and von Kossa staining results showed that conditional knockout of ADAM10 in cranial neural crest cells led to embryonic death, craniofacial dysmorphia and bone defects. Furthermore, we demonstrated that impaired mineralization could be triggered by decreased osteoblast differentiation, increased cell death. Overall, these findings show that ADAM10 plays an essential role in craniofacial bone development. PMID:27221046

  17. Expression of the capacity to release [3H]norepinephrine by neural crest cultures

    International Nuclear Information System (INIS)

    Cultures of trunk neural crest cells from quail embryos were tested for their ability to release [3H]norepinephrine [(3H]NE) in response to depolarization. After 7 days in vitro, exposure of the cultures to either the alkaloid veratridine or 40 mM K+ results in the evoked release of [3H]NE. The release evoked by veratridine is blocked in the presence of tetrodotoxin. The release evoked by increased K+ is blocked by the calcium antagonist cobalt. Release in response to the nicotinic cholinergic agonist 1,1-dimethyl-4-phenylpiperazine was also observed. The amount of evoked release is highly correlated with the number of histochemically demonstrable catecholamine-containing cells in a given culture. Autoradiography reveals that the radioactivity taken up by these cultures is located in a subpopulation of cells whose morphology resembles that of the histochemically detectable catecholamine-containing cell population. Whereas capacity for the release of [3H] NE is readily detectable after 7 days in vitro, it is detectable only with difficulty after 4 days in vitro. There is a greater than 6-fold increase in uptake capacity over the period of 4 to 7 days in vitro. These results demonstrate that neural crest cultures grown without their normal synaptic inputs or targets can exhibit the capacity for stimulus secretion coupling characteristic of synaptic neurotransmitter release

  18. IKAP/Elp1 is required in vivo for neurogenesis and neuronal survival, but not for neural crest migration.

    Directory of Open Access Journals (Sweden)

    Barbara J Hunnicutt

    Full Text Available Familial Dysautonomia (FD; Hereditary Sensory Autonomic Neuropathy; HSAN III manifests from a failure in development of the peripheral sensory and autonomic nervous systems. The disease results from a point mutation in the IKBKAP gene, which encodes the IKAP protein, whose function is still unresolved in the developing nervous system. Since the neurons most severely depleted in the disease derive from the neural crest, and in light of data identifying a role for IKAP in cell motility and migration, it has been suggested that FD results from a disruption in neural crest migration. To determine the function of IKAP during development of the nervous system, we (1 first determined the spatial-temporal pattern of IKAP expression in the developing peripheral nervous system, from the onset of neural crest migration through the period of programmed cell death in the dorsal root ganglia, and (2 using RNAi, reduced expression of IKBKAP mRNA in the neural crest lineage throughout the process of dorsal root ganglia (DRG development in chick embryos in ovo. Here we demonstrate that IKAP is not expressed by neural crest cells and instead is expressed as neurons differentiate both in the CNS and PNS, thus the devastation of the PNS in FD could not be due to disruptions in neural crest motility or migration. In addition, we show that alterations in the levels of IKAP, through both gain and loss of function studies, perturbs neuronal polarity, neuronal differentiation and survival. Thus IKAP plays pleiotropic roles in both the peripheral and central nervous systems.

  19. Disruption of CXCR4 signaling in pharyngeal neural crest cells causes DiGeorge syndrome-like malformations.

    Science.gov (United States)

    Escot, Sophie; Blavet, Cédrine; Faure, Emilie; Zaffran, Stéphane; Duband, Jean-Loup; Fournier-Thibault, Claire

    2016-02-15

    DiGeorge syndrome (DGS) is a congenital disease causing cardiac outflow tract anomalies, craniofacial dysmorphogenesis, thymus hypoplasia, and mental disorders. It results from defective development of neural crest cells (NCs) that colonize the pharyngeal arches and contribute to lower jaw, neck and heart tissues. Although TBX1 has been identified as the main gene accounting for the defects observed in human patients and mouse models, the molecular mechanisms underlying DGS etiology are poorly identified. The recent demonstrations that the SDF1/CXCR4 axis is implicated in NC chemotactic guidance and impaired in cortical interneurons of mouse DGS models prompted us to search for genetic interactions between Tbx1, Sdf1 (Cxcl12) and Cxcr4 in pharyngeal NCs and to investigate the effect of altering CXCR4 signaling on the ontogeny of their derivatives, which are affected in DGS. Here, we provide evidence that Cxcr4 and Sdf1 are genetically downstream of Tbx1 during pharyngeal NC development and that reduction of CXCR4 signaling causes misrouting of pharyngeal NCs in chick and dramatic morphological alterations in the mandibular skeleton, thymus and cranial sensory ganglia. Our results therefore support the possibility of a pivotal role for the SDF1/CXCR4 axis in DGS etiology. PMID:26755698

  20. In vivo tumorigenesis was observed after injection of in vitro expanded neural crest stem cells isolated from adult bone marrow.

    Directory of Open Access Journals (Sweden)

    Sabine Wislet-Gendebien

    Full Text Available Bone marrow stromal cells are adult multipotent cells that represent an attractive tool in cellular therapy strategies. Several studies have reported that in vitro passaging of mesenchymal stem cells alters the functional and biological properties of those cells, leading to the accumulation of genetic aberrations. Recent studies described bone marrow stromal cells (BMSC as mixed populations of cells including mesenchymal (MSC and neural crest stem cells (NCSC. Here, we report the transformation of NCSC into tumorigenic cells, after in vitro long-term passaging. Indeed, the characterization of 6 neural crest-derived clones revealed the presence of one tumorigenic clone. Transcriptomic analyses of this clone highlighted, among others, numerous cell cycle checkpoint modifications and chromosome 11q down-regulation (suggesting a deletion of chromosome 11q compared with the other clones. Moreover, unsupervised analysis such as a dendrogram generated after agglomerative hierarchical clustering comparing several transcriptomic data showed important similarities between the tumorigenic neural crest-derived clone and mammary tumor cell lines. Altogether, it appeared that NCSC isolated from adult bone marrow represents a potential danger for cellular therapy, and consequently, we recommend that phenotypic, functional and genetic assays should be performed on bone marrow mesenchymal and neural crest stem cells before in vivo use, to demonstrate whether their biological properties, after ex vivo expansion, remain suitable for clinical application.

  1. In vivo tumorigenesis was observed after injection of in vitro expanded neural crest stem cells isolated from adult bone marrow.

    Science.gov (United States)

    Wislet-Gendebien, Sabine; Poulet, Christophe; Neirinckx, Virginie; Hennuy, Benoit; Swingland, James T; Laudet, Emerence; Sommer, Lukas; Shakova, Olga; Bours, Vincent; Rogister, Bernard

    2012-01-01

    Bone marrow stromal cells are adult multipotent cells that represent an attractive tool in cellular therapy strategies. Several studies have reported that in vitro passaging of mesenchymal stem cells alters the functional and biological properties of those cells, leading to the accumulation of genetic aberrations. Recent studies described bone marrow stromal cells (BMSC) as mixed populations of cells including mesenchymal (MSC) and neural crest stem cells (NCSC). Here, we report the transformation of NCSC into tumorigenic cells, after in vitro long-term passaging. Indeed, the characterization of 6 neural crest-derived clones revealed the presence of one tumorigenic clone. Transcriptomic analyses of this clone highlighted, among others, numerous cell cycle checkpoint modifications and chromosome 11q down-regulation (suggesting a deletion of chromosome 11q) compared with the other clones. Moreover, unsupervised analysis such as a dendrogram generated after agglomerative hierarchical clustering comparing several transcriptomic data showed important similarities between the tumorigenic neural crest-derived clone and mammary tumor cell lines. Altogether, it appeared that NCSC isolated from adult bone marrow represents a potential danger for cellular therapy, and consequently, we recommend that phenotypic, functional and genetic assays should be performed on bone marrow mesenchymal and neural crest stem cells before in vivo use, to demonstrate whether their biological properties, after ex vivo expansion, remain suitable for clinical application. PMID:23071568

  2. Phosphorylation of Sox9 is required for neural crest delamination and is regulated downstream of BMP and canonical Wnt signaling

    OpenAIRE

    Liu, Jessica A. J.; Wu, Ming-Hoi; Yan, Carol H.; Chau, Bolton K H; So,Henry; Ng, Alvis; CHAN, Alan; Cheah, Kathryn S.E.; Briscoe, James; Cheung, Martin

    2013-01-01

    Coordination of neural crest cell (NCC) induction and delamination is orchestrated by several transcription factors. Among these, Sry-related HMG box-9 (Sox9) and Snail2 have been implicated in both the induction of NCC identity and, together with phoshorylation, NCC delamination. How phosphorylation effects this function has not been clear. Here we show, in the developing chick neural tube, that phosphorylation of Sox9 on S64 and S181 facilitates its SUMOylation, and the phosphorylated forms...

  3. Cranial neural crest cells on the move: their roles in craniofacial development.

    Science.gov (United States)

    Cordero, Dwight R; Brugmann, Samantha; Chu, Yvonne; Bajpai, Ruchi; Jame, Maryam; Helms, Jill A

    2011-02-01

    The craniofacial region is assembled through the active migration of cells and the rearrangement and sculpting of facial prominences and pharyngeal arches, which consequently make it particularly susceptible to a large number of birth defects. Genetic, molecular, and cellular processes must be temporally and spatially regulated to culminate in the three-dimension structures of the face. The starting constituent for the majority of skeletal and connective tissues in the face is a pluripotent population of cells, the cranial neural crest cells (NCCs). In this review we discuss the newest scientific findings in the development of the craniofacial complex as related to NCCs. Furthermore, we present recent findings on NCC diseases called neurocristopathies and, in doing so, provide clinicians with new tools for understanding a growing number of craniofacial genetic disorders. PMID:21271641

  4. Molecular control of the neural crest and peripheral nervous system development.

    Science.gov (United States)

    Newbern, Jason M

    2015-01-01

    A transient and unique population of multipotent stem cells, known as neural crest cells (NCCs), generate a bewildering array of cell types during vertebrate development. An attractive model among developmental biologists, the study of NCC biology has provided a wealth of knowledge regarding the cellular and molecular mechanisms important for embryogenesis. Studies in numerous species have defined how distinct phases of NCC specification, proliferation, migration, and survival contribute to the formation of multiple functionally distinct organ systems. NCC contributions to the peripheral nervous system (PNS) are well known. Critical developmental processes have been defined that provide outstanding models for understanding how extracellular stimuli, cell-cell interactions, and transcriptional networks cooperate to direct cellular diversification and PNS morphogenesis. Dissecting the complex extracellular and intracellular mechanisms that mediate the formation of the PNS from NCCs may have important therapeutic implications for neurocristopathies, neuropathies, and certain forms of cancer. PMID:25662262

  5. Leader Cells Define Directionality of Trunk, but Not Cranial, Neural Crest Cell Migration.

    Science.gov (United States)

    Richardson, Jo; Gauert, Anton; Briones Montecinos, Luis; Fanlo, Lucía; Alhashem, Zainalabdeen Mohmammed; Assar, Rodrigo; Marti, Elisa; Kabla, Alexandre; Härtel, Steffen; Linker, Claudia

    2016-05-31

    Collective cell migration is fundamental for life and a hallmark of cancer. Neural crest (NC) cells migrate collectively, but the mechanisms governing this process remain controversial. Previous analyses in Xenopus indicate that cranial NC (CNC) cells are a homogeneous population relying on cell-cell interactions for directional migration, while chick embryo analyses suggest a heterogeneous population with leader cells instructing directionality. Our data in chick and zebrafish embryos show that CNC cells do not require leader cells for migration and all cells present similar migratory capacities. In contrast, laser ablation of trunk NC (TNC) cells shows that leader cells direct movement and cell-cell contacts are required for migration. Moreover, leader and follower identities are acquired before the initiation of migration and remain fixed thereafter. Thus, two distinct mechanisms establish the directionality of CNC cells and TNC cells. This implies the existence of multiple molecular mechanisms for collective cell migration. PMID:27210753

  6. Generation and characterization of a novel neural crest marker allele, Inka1-LacZ, reveals a role for Inka1 in mouse neural tube closure

    OpenAIRE

    Reid, Bethany S.; Sargent, Thomas D.; Williams, Trevor

    2010-01-01

    Previous studies identified Inka1 as a gene regulated by AP-2α in the neural crest required for craniofacial morphogenesis in fish and frog. Here, we extend the analysis of Inka1 function and regulation to the mouse by generating a LacZ knock-in allele. Inka1-LacZ allele expression occurs in the cephalic mesenchyme, heart, and paraxial mesoderm prior to E8.5. Subsequently, expression is observed in the migratory neural crest cells and their derivatives. Consistent with expression of Inka1 in ...

  7. [Transplanted epidermal neural crest stem cell in a peripheral nerve gap].

    Science.gov (United States)

    Zhang, Lu; Zhang, Jieyuan; Li, Bingcang; Liu, Zheng; Liu, Bin

    2014-04-01

    Neural crest stem cells originated from hair follicle (epidermal neural crest stem cell, EPI-NCSC) are easy to obtain and have potentials to differentiate into various tissues, which make them eminent seed cells for tissue engineering. EPI-NCSC is now used to repair nerve injury, especially, the spinal cord injury. To investigate their effects on repairing peripheral nerve injury, EPI-NCSC from a GFP-SD rat were primarily cultured on coated dishes and on a poly lactic acid coglycolic acid copolymer (PLGA) membrane. Methyl thiazolyl tetrazolium (MTT) assay showed that the initial adhesion rate of EPI-NCSC was 89.7% on PLGA membrane, and the relative growth rates were 89.3%, 87.6%, 85.6%, and 96.6% on the 1st, 3rd, 5th, 7th day respectively. Cell cycles and DNA ploidy analysis demonstrated that cell cycles and proliferation indexes of cultured EPI-NCSC had the same variation pattern on coated dishes and PLGA membrane. Then cultured EPI-NCSC were mixed with equal amount of extracellular matrix and injected into a PLGA conduit to connect a 10 mm surgery excision gap of rat sciatic nerve, Dulbecco's Modified Eagle's medium (DMEM) was used to substitute EPI-NCSC in the control group. After four weeks of transplantation, the defected sciatic nerve achieved a histological restoration, the sensory function of rat hind limb was partly recovered and the sciatic nerve index was also improved. The above results showed that a PLGA conduit filled with EPI-NCSC has a good repair effect on the peripheral nerve injury. PMID:25195250

  8. Grouping of histone deacetylase inhibitors and other toxicants disturbing neural crest migration by transcriptional profiling.

    Science.gov (United States)

    Dreser, Nadine; Zimmer, Bastian; Dietz, Christian; Sügis, Elena; Pallocca, Giorgia; Nyffeler, Johanna; Meisig, Johannes; Blüthgen, Nils; Berthold, Michael R; Waldmann, Tanja; Leist, Marcel

    2015-09-01

    Functional assays, such as the "migration inhibition of neural crest cells" (MINC) developmental toxicity test, can identify toxicants without requiring knowledge on their mode of action (MoA). Here, we were interested, whether (i) inhibition of migration by structurally diverse toxicants resulted in a unified signature of transcriptional changes; (ii) whether statistically-identified transcript patterns would inform on compound grouping even though individual genes were little regulated, and (iii) whether analysis of a small group of biologically-relevant transcripts would allow the grouping of compounds according to their MoA. We analyzed transcripts of 35 'migration genes' after treatment with 16 migration-inhibiting toxicants. Clustering, principal component analysis and correlation analyses of the data showed that mechanistically related compounds (e.g. histone deacetylase inhibitors (HDACi), PCBs) triggered similar transcriptional changes, but groups of structurally diverse toxicants largely differed in their transcriptional effects. Linear discriminant analysis (LDA) confirmed the specific clustering of HDACi across multiple separate experiments. Similarity of the signatures of the HDACi trichostatin A and suberoylanilide hydroxamic acid to the one of valproic acid (VPA), suggested that the latter compound acts as HDACi when impairing neural crest migration. In conclusion, the data suggest that (i) a given functional effect (e.g. inhibition of migration) can be associated with highly diverse signatures of transcript changes; (ii) statistically significant grouping of mechanistically-related compounds can be achieved on the basis of few genes with small regulations. Thus, incorporation of mechanistic markers in functional in vitro tests may support read-across procedures, also for structurally un-related compounds. PMID:26238599

  9. Genomic factors that shape craniofacial outcome and neural crest vulnerability in FASD

    Directory of Open Access Journals (Sweden)

    Susan M. Smith

    2014-08-01

    Full Text Available Prenatal alcohol exposure (PAE causes distinctive facial characteristics in some pregnancies and not others; genetic factors may contribute to this differential vulnerability. Ethanol disrupts multiple events of neural crest development including induction, survival, migration, and differentiation. Animal models and genomic approaches have substantially advanced our understanding of the mechanisms underlying these facial changes. PAE during gastrulation produces craniofacial changes corresponding with human fetal alcohol syndrome. These result because PAE reduces prechordal plate extension and suppresses sonic hedgehog, leading to holoprosencephaly and malpositioned facial primordia. Haploinsufficiency in sonic hedgehog signaling increases vulnerability to facial deficits and may influence some PAE pregnancies. In contrast, PAE during early neurogenesis produces facial hypoplasia, preceded by neural crest reductions due to significant apoptosis. Factors mediating this apoptosis include intracellular calcium mobilization, elevated reactive oxygen species, and loss of trophic support from β-catenin/calcium, sonic hedgehog, and mTOR signaling. Genomewide SNP analysis links PDGF receptor genes with facial outcomes in human PAE. Multiple genomic-level comparisons of ethanol-sensitive and –resistant early embryos, in both mouse and chick, independently identify common candidate genes that may potentially modify craniofacial vulnerability, including ribosomal proteins, proteosome, RNA splicing, and focal adhesion. In summary, research using animal models with genome-level differences in ethanol vulnerability, as well as targeted loss- and gain-of-function mutants, has clarified the mechanisms mediating craniofacial change in PAE. The findings additionally suggest that craniofacial deficits may represent a gene-ethanol interaction for some affected individuals. Genetic-level changes may prime individuals toward greater sensitivity or resistance to

  10. In vivo time-lapse imaging reveals extensive neural crest and endothelial cell interactions during neural crest migration and formation of the dorsal root and sympathetic ganglia.

    Science.gov (United States)

    George, Lynn; Dunkel, Haley; Hunnicutt, Barbara J; Filla, Michael; Little, Charles; Lansford, Rusty; Lefcort, Frances

    2016-05-01

    During amniote embryogenesis the nervous and vascular systems interact in a process that significantly affects the respective morphogenesis of each network by forming a "neurovascular" link. The importance of neurovascular cross-talk in the central nervous system has recently come into focus with the growing awareness that these two systems interact extensively both during development, in the stem-cell niche, and in neurodegenerative conditions such as Alzheimer's Disease and Amyotrophic Lateral Sclerosis. With respect to the peripheral nervous system, however, there have been no live, real-time investigations of the potential relationship between these two developing systems. To address this deficit, we used multispectral 4D time-lapse imaging in a transgenic quail model in which endothelial cells (ECs) express a yellow fluorescent marker, while neural crest cells (NCCs) express an electroporated red fluorescent marker. We monitored EC and NCC migration in real-time during formation of the peripheral nervous system. Our time-lapse recordings indicate that NCCs and ECs are physically juxtaposed and dynamically interact at multiple locations along their trajectories. These interactions are stereotypical and occur at precise anatomical locations along the NCC migratory pathway. NCCs migrate alongside the posterior surface of developing intersomitic vessels, but fail to cross these continuous streams of motile ECs. NCCs change their morphology and migration trajectory when they encounter gaps in the developing vasculature. Within the nascent dorsal root ganglion, proximity to ECs causes filopodial retraction which curtails forward persistence of NCC motility. Overall, our time-lapse recordings support the conclusion that primary vascular networks substantially influence the distribution and migratory behavior of NCCs and the patterned formation of dorsal root and sympathetic ganglia. PMID:26988118

  11. Phosphorylation of Sox9 is required for neural crest delamination and is regulated downstream of BMP and canonical Wnt signaling.

    Science.gov (United States)

    Liu, Jessica A J; Wu, Ming-Hoi; Yan, Carol H; Chau, Bolton K H; So, Henry; Ng, Alvis; Chan, Alan; Cheah, Kathryn S E; Briscoe, James; Cheung, Martin

    2013-02-19

    Coordination of neural crest cell (NCC) induction and delamination is orchestrated by several transcription factors. Among these, Sry-related HMG box-9 (Sox9) and Snail2 have been implicated in both the induction of NCC identity and, together with phoshorylation, NCC delamination. How phosphorylation effects this function has not been clear. Here we show, in the developing chick neural tube, that phosphorylation of Sox9 on S64 and S181 facilitates its SUMOylation, and the phosphorylated forms of Sox9 are essential for trunk neural crest delamination. Both phosphorylation and to a lesser extent SUMOylation, of Sox9 are required to cooperate with Snail2 to promote delamination. Moreover, bone morphogenetic protein and canonical Wnt signaling induce phosphorylation of Sox9, thereby connecting extracellular signals with the delamination of NCCs. Together the data suggest a model in which extracellular signals initiate phosphorylation of Sox9 and its cooperation with Snail2 to induce NCC delamination. PMID:23382206

  12. Induction of neural crest in Xenopus by transcription factor AP2alpha.

    Science.gov (United States)

    Luo, Ting; Lee, Young-Hoon; Saint-Jeannet, Jean-Pierre; Sargent, Thomas D

    2003-01-21

    We report experiments with Xenopus laevis, using both intact embryos and ectodermal explants, showing that the transcription factor AP2alpha is positively regulated by bone morphogenetic protein (BMP) and Wnt signaling, and that this activation is an essential step in the induction of neural crest (NC). Ectopic expression of AP2alpha is sufficient to activate high-level expression of NC-specific genes such as Slug and Sox9, which can occur as isolated domains within the neural plate as well as by expansion of endogenous NC territories. AP2alpha also has the property of inducing NC in isolated ectoderm in which Wnt signaling is provided but BMP signaling is minimized by overexpression of chordin. Like other NC regulatory factors, activation of AP2alpha requires some attenuation of endogenous BMP signaling; however, this process occurs at a lower threshold for AP2alpha. Furthermore, AP2alpha expression domains are larger than for other NC factors. Loss-of-function experiments with antisense AP2alpha morpholino oligonucleotides result in severe reduction in the NC territory. These results support a central role for AP2alpha in NC induction. We propose a model in which AP2alpha expression, along with inactivation of NC inhibitory factors such as Dlx3, establish a feedback loop comprising AP2alpha, Sox9, and Slug, leading to and maintaining NC specification. PMID:12511599

  13. Fluorescence-Activated Cell Sorting of EGFP-Labeled Neural Crest Cells From Murine Embryonic Craniofacial Tissue

    Directory of Open Access Journals (Sweden)

    Saurabh Singh

    2005-01-01

    Full Text Available During the early stages of embryogenesis, pluripotent neural crest cells (NCC are known to migrate from the neural folds to populate multiple target sites in the embryo where they differentiate into various derivatives, including cartilage, bone, connective tissue, melanocytes, glia, and neurons of the peripheral nervous system. The ability to obtain pure NCC populations is essential to enable molecular analyses of neural crest induction, migration, and/or differentiation. Crossing Wnt1-Cre and Z/EG transgenic mouse lines resulted in offspring in which the Wnt1-Cre transgene activated permanent EGFP expression only in NCC. The present report demonstrates a flow cytometric method to sort and isolate populations of EGFP-labeled NCC. The identity of the sorted neural crest cells was confirmed by assaying expression of known marker genes by TaqMan Quantitative Real-Time Polymerase Chain Reaction (QRT-PCR. The molecular strategy described in this report provides a means to extract intact RNA from a pure population of NCC thus enabling analysis of gene expression in a defined population of embryonic precursor cells critical to development.

  14. Stem Cells from Human Exfoliated Deciduous Tooth Exhibit Stromal-Derived Inducing Activity and Lead to Generation of Neural Crest Cells from Human Embryonic Stem Cells

    Directory of Open Access Journals (Sweden)

    Khadijeh Karbalaie

    2015-04-01

    Full Text Available Objective: The neural crest is a transient structure of early vertebrate embryos that generates neural crest cells (NCCs. These cells can migrate throughout the body and produce a diverse array of mature tissue types. Due to the ethical and technical problems surrounding the isolation of these early human embryo cells, researchers have focused on in vitro studies to produce NCCs and increase their knowledge of neural crest development. Materials and Methods: In this experimental study, we cultured human embryonic stem cells (hESCs on stromal stem cells from human exfoliated deciduous teeth (SHED for a two-week period. We used different approaches to characterize these differentiated cells as neural precursor cells (NPCs and NCCs. Results: In the first co-culture week, hESCs appeared as crater-like structures with marginal rosettes. NPCs derived from these structures expressed the early neural crest marker p75 in addition to numerous other genes associated with neural crest induction such as SNAIL, SLUG, PTX3 and SOX9. Flow cytometry analysis showed 70% of the cells were AP2/P75 positive. Moreover, the cells were able to self-renew, sustain multipotent differentiation potential, and readily form neurospheres in suspension culture. Conclusion: SHED, as an adult stem cell with a neural crest origin, has stromal-derived inducing activity (SDIA and can be used as an NCC inducer from hESCs. These cells provide an invaluable resource to study neural crest differentiation in both normal and disordered human neural crest development.

  15. IN VITRO PROPERTIES OF NEURAL CREST-DERIVED MULTIPOTENT STEM CELLS FROM A BULGE REGION OF WHISKER FOLLICLE

    Directory of Open Access Journals (Sweden)

    R. G. Vasyliev

    2014-08-01

    Full Text Available A culture method for multipotent neural crest-derived stem cell isolated from the bulge region of the hair follicle of whisker pad of adult mice has been described and their biological properties have been studied. It was shown that the cells possess a fibroblast-like morphology, they are nestin-positive and cytokeratin-negative, and also express the following surface markers: CD44, CD73, CD90 and Sca-1. This cell type shows the functional properties of stem cells in culture: clonogenicity, self-renewal, sphere-forming capacity and the ability to the directed multilineage differentiation. Due to these properties, neural crest-derived multipotent stem cells are promising for application in the regenerative medicine

  16. Evaluation of Developmental Toxicants and Signaling Pathways in a Functional Test Based on the Migration of Human Neural Crest Cells

    OpenAIRE

    Zimmer, Bastian; Lee, Gabsang; Balmer, Nina V.; Meganathan, Kesavan; Sachinidis, Agapios; Studer, Lorenz; Leist, Marcel

    2012-01-01

    Background: Information on the potential developmental toxicity (DT) of the majority of chemicals is scarce, and test capacities for further animal-based testing are limited. Therefore, new approaches with higher throughput are required. A screening strategy based on the use of relevant human cell types has been proposed by the U.S. Environmental Protection Agency and others. Because impaired neural crest (NC) function is one of the known causes for teratologic effects, testing of toxicant ef...

  17. Efficient genome editing of genes involved in neural crest development using the CRISPR/Cas9 system in Xenopus embryos

    OpenAIRE

    Liu, Zhongzhen; Cheng, Tina Tsz Kwan; Shi, Zhaoying; Liu, Ziran; Lei, Yong; Wang, Chengdong; Shi, Weili; Chen, Xiongfeng; Qi, Xufeng; Cai, Dongqing; Feng, Bo; Deng, Yi; Chen, Yonglong; Zhao, Hui

    2016-01-01

    Background The RNA guided CRISPR/Cas9 nucleases have been proven to be effective for gene disruption in various animal models including Xenopus tropicalis. The neural crest (NC) is a transient cell population during embryonic development and contributes to a large variety of tissues. Currently, loss-of-function studies on NC development in X. tropicalis are largely based on morpholino antisense oligonucleotide. It is worthwhile establishing targeted gene knockout X. tropicails line using CRIS...

  18. In vivo tumorigenesis was observed after injection of in vitro expanded neural crest stem cells isolated from adult bone marrow

    OpenAIRE

    Sabine Wislet-Gendebien; Christophe Poulet; Virginie Neirinckx; Benoit Hennuy; Swingland, James T.; Emerence Laudet; Lukas Sommer; Olga Shakova; Vincent Bours; Bernard Rogister

    2012-01-01

    Bone marrow stromal cells are adult multipotent cells that represent an attractive tool in cellular therapy strategies. Several studies have reported that in vitro passaging of mesenchymal stem cells alters the functional and biological properties of those cells, leading to the accumulation of genetic aberrations. Recent studies described bone marrow stromal cells (BMSC) as mixed populations of cells including mesenchymal (MSC) and neural crest stem cells (NCSC). Here, we report the ...

  19. Conditional beta1-integrin gene deletion in neural crest cells causes severe developmental alterations of the peripheral nervous system

    DEFF Research Database (Denmark)

    Pietri, Thomas; Eder, Olivier; Breau, Marie Anne;

    2004-01-01

    Integrins are transmembrane receptors that are known to interact with the extracellular matrix and to be required for migration, proliferation, differentiation and apoptosis. We have generated mice with a neural crest cell-specific deletion of the beta1-integrin gene to analyse the role of beta1-...... almost complete absence of Schwann cells and sensory axon segregation and defective maturation in neuromuscular synaptogenesis. Thus, beta1-integrins are important for the control of embryonic and postnatal peripheral nervous system development....

  20. The EJC component Magoh regulates proliferation and expansion of neural crest-derived melanocytes.

    Science.gov (United States)

    Silver, Debra L; Leeds, Karen E; Hwang, Hun-Way; Miller, Emily E; Pavan, William J

    2013-03-15

    Melanoblasts are a population of neural crest-derived cells that generate the pigment-producing cells of our body. Defective melanoblast development and function underlies many disorders including Waardenburg syndrome and melanoma. Understanding the genetic regulation of melanoblast development will help elucidate the etiology of these and other neurocristopathies. Here we demonstrate that Magoh, a component of the exon junction complex, is required for normal melanoblast development. Magoh haploinsufficient mice are hypopigmented and exhibit robust genetic interactions with the transcription factor, Sox10. These phenotypes are caused by a marked reduction in melanoblast number beginning at mid-embryogenesis. Strikingly, while Magoh haploinsufficiency severely reduces epidermal melanoblasts, it does not significantly affect the number of dermal melanoblasts. These data indicate Magoh impacts melanoblast development by disproportionately affecting expansion of epidermal melanoblast populations. We probed the cellular basis for melanoblast reduction and discovered that Magoh mutant melanoblasts do not undergo increased apoptosis, but instead are arrested in mitosis. Mitotic arrest is evident in both Magoh haploinsufficient embryos and in Magoh siRNA treated melanoma cell lines. Together our findings indicate that Magoh-regulated proliferation of melanoblasts in the dermis may be critical for production of epidermally-bound melanoblasts. Our results point to a central role for Magoh in melanocyte development. PMID:23333945

  1. Fibronectin promotes differentiation of neural crest progenitors endowed with smooth muscle cell potential

    International Nuclear Information System (INIS)

    The neural crest (NC) is a model system used to investigate multipotency during vertebrate development. Environmental factors control NC cell fate decisions. Despite the well-known influence of extracellular matrix molecules in NC cell migration, the issue of whether they also influence NC cell differentiation has not been addressed at the single cell level. By analyzing mass and clonal cultures of mouse cephalic and quail trunk NC cells, we show for the first time that fibronectin (FN) promotes differentiation into the smooth muscle cell phenotype without affecting differentiation into glia, neurons, and melanocytes. Time course analysis indicated that the FN-induced effect was not related to massive cell death or proliferation of smooth muscle cells. Finally, by comparing clonal cultures of quail trunk NC cells grown on FN and collagen type IV (CLIV), we found that FN strongly increased both NC cell survival and the proportion of unipotent and oligopotent NC progenitors endowed with smooth muscle potential. In contrast, melanocytic progenitors were prominent in clonogenic NC cells grown on CLIV. Taken together, these results show that FN promotes NC cell differentiation along the smooth muscle lineage, and therefore plays an important role in fate decisions of NC progenitor cells

  2. Involvement of seven in absentia homolog-1 in ethanol-induced apoptosis in neural crest cells

    Science.gov (United States)

    Sun, Haijing; Chen, Xiaopan; Yuan, Fuqiang; Liu, Jie; Zhao, Yingming; Chen, Shao-yu

    2014-01-01

    Ethanol-induced apoptosis in selected cell populations is a major component of pathogenesis underlying ethanol-induced teratogenesis. However, there is a fundamental gap in understanding how ethanol leads to apoptosis in embryos. In this study, we investigate the role of seven in absentia homolog-1 (Siah1) protein, an E3 ubiquitin ligase, in ethanol-induced apoptosis. Using an in vitro model of neural crest cell (NCC), JoMa1.3 cells, we found that exposure to 100 mM ethanol resulted in a significant increase in Siah1 mRNA expression in NCCs, an ethanol-sensitive cell population implicated in Fetal Alcohol Spectrum Disorders (FASD). Treatment with 100 mM ethanol for 24 hours also significantly increased the protein expression of Siah1 in JoMa1.3 cells. The nuclear translocation and accumulation of Siah1 was evidenced in the cells exposed to ethanol. In addition, we have found that the inhibition of Siah1 function with siRNA prevents ethanol-induced increase in Siah1 protein expression and nuclear translocation in NCCs. Down-regulation of Siah1 by siRNA also greatly diminished ethanol-induced cell death and caspase-3 activation, indicating that inhibition of Siah1 can attenuate ethanol-induced apoptosis. These results strongly suggest that Siah1 plays an important role in ethanol-induced apoptosis in NCCs. PMID:25193017

  3. Are neural crest stem cells the missing link between hematopoietic and neurogenic niches?

    Directory of Open Access Journals (Sweden)

    Virginie Neirinckx

    2015-06-01

    Full Text Available Hematopoietic niches are defined as cellular and molecular microenvironments that regulate hematopoietic stem cell (HSC function together with stem cell autonomous mechanisms. Many different cell types have been characterized as contributors to the formation of HSC niches, such as osteoblasts, endothelial cells, Schwann cells, and mesenchymal progenitors. These mesenchymal progenitors have themselves been classified as CXC chemokine ligand (CXCL12-abundant reticular (CAR cells, stem cell factor expressing cells, or nestin-positive mesenchymal stem cells (MSCs, which have been recently identified as neural crest-derived cells (NCSCs. Together, these cells are spatially associated with HSCs and believed to provide appropriate microenvironments for HSC self-renewal, differentiation, mobilization and hibernation both by cell-to-cell contact and soluble factors. Interestingly, it appears that regulatory pathways governing the hematopoietic niche homeostasis are operating in the neurogenic niche as well. Therefore, this review paper aims to compare both the regulation of hematopoietic and neurogenic niches, in order to highlight the role of NCSCs and nervous system components in the development and the regulation of the hematopoietic system.

  4. Are neural crest stem cells the missing link between hematopoietic and neurogenic niches?

    Science.gov (United States)

    Coste, Cécile; Neirinckx, Virginie; Gothot, André; Wislet, Sabine; Rogister, Bernard

    2015-01-01

    Hematopoietic niches are defined as cellular and molecular microenvironments that regulate hematopoietic stem cell (HSC) function together with stem cell autonomous mechanisms. Many different cell types have been characterized as contributors to the formation of HSC niches, such as osteoblasts, endothelial cells, Schwann cells, and mesenchymal progenitors. These mesenchymal progenitors have themselves been classified as CXC chemokine ligand (CXCL) 12-abundant reticular (CAR) cells, stem cell factor expressing cells, or nestin-positive mesenchymal stem cells (MSCs), which have been recently identified as neural crest-derived cells (NCSCs). Together, these cells are spatially associated with HSCs and believed to provide appropriate microenvironments for HSC self-renewal, differentiation, mobilization and hibernation both by cell-cell contact and soluble factors. Interestingly, it appears that regulatory pathways governing the hematopoietic niche homeostasis are operating in the neurogenic niche as well. Therefore, this review paper aims to compare both the regulation of hematopoietic and neurogenic niches, in order to highlight the role of NCSCs and nervous system components in the development and the regulation of the hematopoietic system. PMID:26136659

  5. Controlled levels of canonical Wnt signaling are required for neural crest migration.

    Science.gov (United States)

    Maj, Ewa; Künneke, Lutz; Loresch, Elisabeth; Grund, Anita; Melchert, Juliane; Pieler, Tomas; Aspelmeier, Timo; Borchers, Annette

    2016-09-01

    Canonical Wnt signaling plays a dominant role in the development of the neural crest (NC), a highly migratory cell population that generates a vast array of cell types. Canonical Wnt signaling is required for NC induction as well as differentiation, however its role in NC migration remains largely unknown. Analyzing nuclear localization of β-catenin as readout for canonical Wnt activity, we detect nuclear β-catenin in premigratory but not migratory Xenopus NC cells suggesting that canonical Wnt activity has to decrease to basal levels to enable NC migration. To define a possible function of canonical Wnt signaling in Xenopus NC migration, canonical Wnt signaling was modulated at different time points after NC induction. This was accomplished using either chemical modulators affecting β-catenin stability or inducible glucocorticoid fusion constructs of Lef/Tcf transcription factors. In vivo analysis of NC migration by whole mount in situ hybridization demonstrates that ectopic activation of canonical Wnt signaling inhibits cranial NC migration. Further, NC transplantation experiments confirm that this effect is tissue-autonomous. In addition, live-cell imaging in combination with biophysical data analysis of explanted NC cells confirms the in vivo findings and demonstrates that modulation of canonical Wnt signaling affects the ability of NC cells to perform single cell migration. Thus, our data support the hypothesis that canonical Wnt signaling needs to be tightly controlled to enable migration of NC cells. PMID:27341758

  6. Regulators of gene expression in Enteric Neural Crest Cells are putative Hirschsprung disease genes.

    Science.gov (United States)

    Schriemer, Duco; Sribudiani, Yunia; IJpma, Arne; Natarajan, Dipa; MacKenzie, Katherine C; Metzger, Marco; Binder, Ellen; Burns, Alan J; Thapar, Nikhil; Hofstra, Robert M W; Eggen, Bart J L

    2016-08-01

    The enteric nervous system (ENS) is required for peristalsis of the gut and is derived from Enteric Neural Crest Cells (ENCCs). During ENS development, the RET receptor tyrosine kinase plays a critical role in the proliferation and survival of ENCCs, their migration along the developing gut, and differentiation into enteric neurons. Mutations in RET and its ligand GDNF cause Hirschsprung disease (HSCR), a complex genetic disorder in which ENCCs fail to colonize variable lengths of the distal bowel. To identify key regulators of ENCCs and the pathways underlying RET signaling, gene expression profiles of untreated and GDNF-treated ENCCs from E14.5 mouse embryos were generated. ENCCs express genes that are involved in both early and late neuronal development, whereas GDNF treatment induced neuronal maturation. Predicted regulators of gene expression in ENCCs include the known HSCR genes Ret and Sox10, as well as Bdnf, App and Mapk10. The regulatory overlap and functional interactions between these genes were used to construct a regulatory network that is underlying ENS development and connects to known HSCR genes. In addition, the adenosine receptor A2a (Adora2a) and neuropeptide Y receptor Y2 (Npy2r) were identified as possible regulators of terminal neuronal differentiation in GDNF-treated ENCCs. The human orthologue of Npy2r maps to the HSCR susceptibility locus 4q31.3-q32.3, suggesting a role for NPY2R both in ENS development and in HSCR. PMID:27266404

  7. MycN Is Critical for the Maintenance of Human Embryonic Stem Cell-Derived Neural Crest Stem Cells.

    Science.gov (United States)

    Zhang, Jie Ting; Weng, Zhi Hui; Tsang, Kam Sze; Tsang, Lai Ling; Chan, Hsiao Chang; Jiang, Xiao Hua

    2016-01-01

    The biologic studies of human neural crest stem cells (hNCSCs) are extremely challenging due to the limited source of hNCSCs as well as ethical and technical issues surrounding isolation of early human embryonic tissues. On the other hand, vast majority of studies on MycN have been conducted in human tumor cells, thus, the role of MycN in normal human neural crest development is completely unknown. In the present study, we determined the role of MycN in hNCSCs isolated from in vitro-differentiating human embryonic stem cells (hESCs). For the first time, we show that suppression of MycN in hNCSCs inhibits cell growth and cell cycle progression. Knockdown of MycN in hNCSCs increases the expression of Cdkn1a, Cdkn2a and Cdkn2b, which encodes the cyclin-dependent kinases p21CIP1, p16 INK4a and p15INK4b. In addition, MycN is involved in the regulation of human sympathetic neurogenesis, as knockdown of MycN enhances the expression of key transcription factors involved in sympathetic neuron differentiation, including Phox2a, Phox2b, Mash1, Hand2 and Gata3. We propose that unlimited source of hNCSCs provides an invaluable platform for the studies of human neural crest development and diseases. PMID:26815535

  8. MycN Is Critical for the Maintenance of Human Embryonic Stem Cell-Derived Neural Crest Stem Cells.

    Directory of Open Access Journals (Sweden)

    Jie Ting Zhang

    Full Text Available The biologic studies of human neural crest stem cells (hNCSCs are extremely challenging due to the limited source of hNCSCs as well as ethical and technical issues surrounding isolation of early human embryonic tissues. On the other hand, vast majority of studies on MycN have been conducted in human tumor cells, thus, the role of MycN in normal human neural crest development is completely unknown. In the present study, we determined the role of MycN in hNCSCs isolated from in vitro-differentiating human embryonic stem cells (hESCs. For the first time, we show that suppression of MycN in hNCSCs inhibits cell growth and cell cycle progression. Knockdown of MycN in hNCSCs increases the expression of Cdkn1a, Cdkn2a and Cdkn2b, which encodes the cyclin-dependent kinases p21CIP1, p16 INK4a and p15INK4b. In addition, MycN is involved in the regulation of human sympathetic neurogenesis, as knockdown of MycN enhances the expression of key transcription factors involved in sympathetic neuron differentiation, including Phox2a, Phox2b, Mash1, Hand2 and Gata3. We propose that unlimited source of hNCSCs provides an invaluable platform for the studies of human neural crest development and diseases.

  9. E-cadherin is required for cranial neural crest migration in Xenopus laevis.

    Science.gov (United States)

    Huang, Chaolie; Kratzer, Marie-Claire; Wedlich, Doris; Kashef, Jubin

    2016-03-15

    The cranial neural crest (CNC) is a highly motile and multipotent embryonic cell population, which migrates directionally on defined routes throughout the embryo, contributing to facial structures including cartilage, bone and ganglia. Cadherin-mediated cell-cell adhesion is known to play a crucial role in the directional migration of CNC cells. However, migrating CNC co-express different cadherin subtypes, and their individual roles have yet to be fully explored. In previous studies, the expression of individual cadherin subtypes has been analysed using different methods with varying sensitivities, preventing the direct comparison of expression levels. Here, we provide the first comprehensive and comparative analysis of the expression of six cadherin superfamily members during different phases of CNC cell migration in Xenopus. By applying a quantitative RT-qPCR approach, we can determine the copy number and abundance of each expressed cadherin through different phases of CNC migration. Using this approach, we show for the first time expression of E-cadherin and XB/C-cadherin in CNC cells, adding them as two new members of cadherins co-expressed during CNC migration. Cadherin co-expression during CNC migration in Xenopus, in particular the constant expression of E-cadherin, contradicts the classical epithelial-mesenchymal transition (EMT) model postulating a switch in cadherin expression. Loss-of-function experiments further show that E-cadherin is required for proper CNC cell migration in vivo and also for cell protrusion formation in vitro. Knockdown of E-cadherin is not rescued by co-injection of other classical cadherins, pointing to a specific function of E-cadherin in mediating CNC cell migration. Finally, through reconstitution experiments with different E-cadherin deletion mutants in E-cadherin morphant embryos, we demonstrate that the extracellular domain, but not the cytoplasmic domain, of E-cadherin is sufficient to rescue CNC cell migration in vivo

  10. Sonic hedgehog is a chemotactic neural crest cell guide that is perturbed by ethanol exposure.

    Science.gov (United States)

    Tolosa, Ezequiel J; Fernández-Zapico, Martín E; Battiato, Natalia L; Rovasio, Roberto A

    2016-01-01

    Our aim was to understand the involvement of Sonic hedgehog (Shh) morphogen in the oriented distribution of neural crest cells (NCCs) toward the optic vesicle and to look for potential disorders of this guiding mechanism after ethanol exposure. In vitro directional analysis showed the chemotactic response of NCCs up Shh gradients and to notochord co-cultures (Shh source) or to their conditioned medium, a response inhibited by anti-Shh antibody, receptor inhibitor cyclopamine and anti-Smo morpholino (MO). Expression of the Ptch-Smo receptor complex on in vitro NCCs was also shown. In whole embryos, the expression of Shh mRNA and protein was seen in the ocular region, and of Ptch, Smo and Gli/Sufu system on cephalic NCCs. Anti-Smo MO or Ptch-mutated plasmid (Ptch1(Δloop2)) impaired cephalic NCC migration/distribution, with fewer cells invading the optic region and with higher cell density at the homolateral mesencephalic level. Beads embedded with cyclopamine (Smo-blocking) or Shh (ectopic signal) supported the role of Shh as an in vivo guide molecule for cephalic NCCs. Ethanol exposure perturbed in vitro and in vivo NCC migration. Early stage embryos treated with ethanol, in a model reproducing Fetal Alcohol Syndrome, showed later disruptions of craniofacial development associated with abnormal in situ expression of Shh morphogen. The results show the Shh/Ptch/Smo-dependent migration of NCCs toward the optic vesicle, with the support of specific inactivation with genetic and pharmacological tools. They also help to understand mechanisms of accurate distribution of embryonic cells and of their perturbation by a commonly consumed teratogen, and demonstrate, in addition to its other known developmental functions, a new biological activity of cellular guidance for Shh. PMID:26979762

  11. Identification of transcriptome signatures and biomarkers specific for potential developmental toxicants inhibiting human neural crest cell migration.

    Science.gov (United States)

    Pallocca, Giorgia; Grinberg, Marianna; Henry, Margit; Frickey, Tancred; Hengstler, Jan G; Waldmann, Tanja; Sachinidis, Agapios; Rahnenführer, Jörg; Leist, Marcel

    2016-01-01

    The in vitro test battery of the European research consortium ESNATS ('novel stem cell-based test systems') has been used to screen for potential human developmental toxicants. As part of this effort, the migration of neural crest (MINC) assay has been used to evaluate chemical effects on neural crest function. It identified some drug-like compounds in addition to known environmental toxicants. The hits included the HSP90 inhibitor geldanamycin, the chemotherapeutic arsenic trioxide, the flame-retardant PBDE-99, the pesticide triadimefon and the histone deacetylase inhibitors valproic acid and trichostatin A. Transcriptome changes triggered by these substances in human neural crest cells were recorded and analysed here to answer three questions: (1) can toxicants be individually identified based on their transcript profile; (2) how can the toxicity pattern reflected by transcript changes be compacted/dimensionality-reduced for practical regulatory use; (3) how can a reduced set of biomarkers be selected for large-scale follow-up? Transcript profiling allowed clear separation of different toxicants and the identification of toxicant types in a blinded test study. We also developed a diagrammatic system to visualize and compare toxicity patterns of a group of chemicals by giving a quantitative overview of altered superordinate biological processes (e.g. activation of KEGG pathways or overrepresentation of gene ontology terms). The transcript data were mined for potential markers of toxicity, and 39 transcripts were selected to either indicate general developmental toxicity or distinguish compounds with different modes-of-action in read-across. In summary, we found inclusion of transcriptome data to largely increase the information from the MINC phenotypic test. PMID:26705709

  12. Delivery of Epidermal Neural Crest Stem Cells (EPI-NCSC) to hippocamp in Alzheimer's Disease Rat Model

    OpenAIRE

    Esmaeilzade, Banafshe; Nobakht, Maliheh; Joghataei, Mohammad Taghi; Rahbar Roshandel, Nahid; Rasouli, Homa; Samadi Kuchaksaraei, Ali; Hosseini, Seyed Mohammad; Najafzade, Nowruz; Asalgoo, Sara; Hejazian, Leila Beygom; Ghoroghi, Fatima Moghani

    2012-01-01

    Background: Alzheimer’s disease (AD) is characterized by progressive neuronal loss in hippocamp. Epidermal neural crest stem cells (EPI-NCSC) can differentiate into neurons, astrocytes and oligodendrocytes. The purpose of this study was to evaluate the effects of transplanting EPI-NCSC into AD rat model. Methods: Two weeks after induction of AD by injection of Amyloid-β 1-40 into CA1 area of rat hippocamp, Y-maze and single-trial passive avoidance tests were used to show deficit of learning a...

  13. Calponin 2 Acts As an Effector of Noncanonical Wnt-Mediated Cell Polarization during Neural Crest Cell Migration

    OpenAIRE

    Bärbel Ulmer; Cathrin Hagenlocher; Silke Schmalholz; Sabrina Kurz; Axel Schweickert; Ayelet Kohl; Lee Roth; Dalit Sela-Donenfeld; Martin Blum

    2013-01-01

    Neural crest cells (NCCs) migrate throughout the embryo to differentiate into cell types of all germ layers. Initial directed NCC emigration relies on planar cell polarity (PCP), which through the activity of the small GTPases RhoA and Rac governs the actin-driven formation of polarized cell protrusions. We found that the actin binding protein calponin 2 (Cnn2) was expressed in protrusions at the leading edge of migratory NCCs in chicks and frogs. Cnn2 knockdown resulted in NCC migration defe...

  14. Neural crest-mediated bone resorption is a determinant of species-specific jaw length.

    Science.gov (United States)

    Ealba, Erin L; Jheon, Andrew H; Hall, Jane; Curantz, Camille; Butcher, Kristin D; Schneider, Richard A

    2015-12-01

    Precise control of jaw length during development is crucial for proper form and function. Previously we have shown that in birds, neural crest mesenchyme (NCM) confers species-specific size and shape to the beak by regulating molecular and histological programs for the induction and deposition of cartilage and bone. Here we reveal that a hitherto unrecognized but similarly essential mechanism for establishing jaw length is the ability of NCM to mediate bone resorption. Osteoclasts are considered the predominant cells that resorb bone, although osteocytes have also been shown to participate in this process. In adults, bone resorption is tightly coupled to bone deposition as a means to maintain skeletal homeostasis. Yet, the role and regulation of bone resorption during growth of the embryonic skeleton have remained relatively unexplored. We compare jaw development in short-beaked quail versus long-billed duck and find that quail have substantially higher levels of enzymes expressed by bone-resorbing cells including tartrate-resistant acid phosphatase (TRAP), Matrix metalloproteinase 13 (Mmp13), and Mmp9. Then, we transplant NCM destined to form the jaw skeleton from quail to duck and generate chimeras in which osteocytes arise from quail donor NCM and osteoclasts come exclusively from the duck host. Chimeras develop quail-like jaw skeletons coincident with dramatically elevated expression of TRAP, Mmp13, and Mmp9. To test for a link between bone resorption and jaw length, we block resorption using a bisphosphonate, osteoprotegerin protein, or an MMP13 inhibitor, and this significantly lengthens the jaw. Conversely, activating resorption with RANKL protein shortens the jaw. Finally, we find that higher resorption in quail presages their relatively lower adult jaw bone mineral density (BMD) and that BMD is also NCM-mediated. Thus, our experiments suggest that NCM not only controls bone resorption by its own derivatives but also modulates the activity of mesoderm

  15. The taming of the neural crest: a developmental perspective on the origins of morphological covariation in domesticated mammals.

    Science.gov (United States)

    Sánchez-Villagra, Marcelo R; Geiger, Madeleine; Schneider, Richard A

    2016-06-01

    Studies on domestication are blooming, but the developmental bases for the generation of domestication traits and breed diversity remain largely unexplored. Some phenotypic patterns of human neurocristopathies are suggestive of those reported for domesticated mammals and disrupting neural crest developmental programmes have been argued to be the source of traits deemed the 'domestication syndrome'. These character changes span multiple organ systems and morphological structures. But an in-depth examination within the phylogenetic framework of mammals including domesticated forms reveals that the distribution of such traits is not universal, with canids being the only group showing a large set of predicted features. Modularity of traits tied to phylogeny characterizes domesticated mammals: through selective breeding, individual behavioural and morphological traits can be reordered, truncated, augmented or deleted. Similarly, mammalian evolution on islands has resulted in suites of phenotypic changes like those of some domesticated forms. Many domesticated mammals can serve as valuable models for conducting comparative studies on the evolutionary developmental biology of the neural crest, given that series of their embryos are readily available and that their phylogenetic histories and genomes are well characterized. PMID:27429770

  16. Bmps and id2a act upstream of Twist1 to restrict ectomesenchyme potential of the cranial neural crest.

    Directory of Open Access Journals (Sweden)

    Ankita Das

    Full Text Available Cranial neural crest cells (CNCCs have the remarkable capacity to generate both the non-ectomesenchyme derivatives of the peripheral nervous system and the ectomesenchyme precursors of the vertebrate head skeleton, yet how these divergent lineages are specified is not well understood. Whereas studies in mouse have indicated that the Twist1 transcription factor is important for ectomesenchyme development, its role and regulation during CNCC lineage decisions have remained unclear. Here we show that two Twist1 genes play an essential role in promoting ectomesenchyme at the expense of non-ectomesenchyme gene expression in zebrafish. Twist1 does so by promoting Fgf signaling, as well as potentially directly activating fli1a expression through a conserved ectomesenchyme-specific enhancer. We also show that Id2a restricts Twist1 activity to the ectomesenchyme lineage, with Bmp activity preferentially inducing id2a expression in non-ectomesenchyme precursors. We therefore propose that the ventral migration of CNCCs away from a source of Bmps in the dorsal ectoderm promotes ectomesenchyme development by relieving Id2a-dependent repression of Twist1 function. Together our model shows how the integration of Bmp inhibition at its origin and Fgf activation along its migratory route would confer temporal and spatial specificity to the generation of ectomesenchyme from the neural crest.

  17. Distinct functional and temporal requirements for zebrafish Hdac1 during neural crest-derived craniofacial and peripheral neuron development.

    Directory of Open Access Journals (Sweden)

    Myron S Ignatius

    Full Text Available The regulation of gene expression is accomplished by both genetic and epigenetic means and is required for the precise control of the development of the neural crest. In hdac1(b382 mutants, craniofacial cartilage development is defective in two distinct ways. First, fewer hoxb3a, dlx2 and dlx3-expressing posterior branchial arch precursors are specified and many of those that are consequently undergo apoptosis. Second, in contrast, normal numbers of progenitors are present in the anterior mandibular and hyoid arches, but chondrocyte precursors fail to terminally differentiate. In the peripheral nervous system, there is a disruption of enteric, DRG and sympathetic neuron differentiation in hdac1(b382 mutants compared to wildtype embryos. Specifically, enteric and DRG-precursors differentiate into neurons in the anterior gut and trunk respectively, while enteric and DRG neurons are rarely present in the posterior gut and tail. Sympathetic neuron precursors are specified in hdac1(b382 mutants and they undergo generic neuronal differentiation but fail to undergo noradrenergic differentiation. Using the HDAC inhibitor TSA, we isolated enzyme activity and temporal requirements for HDAC function that reproduce hdac1(b382 defects in craniofacial and sympathetic neuron development. Our study reveals distinct functional and temporal requirements for zebrafish hdac1 during neural crest-derived craniofacial and peripheral neuron development.

  18. The zebrafish sf3b1b460 mutant reveals differential requirements for the sf3b1 pre-mRNA processing gene during neural crest development.

    Science.gov (United States)

    An, Min; Henion, Paul D

    2012-01-01

    The functions of gene regulatory networks that control embryonic cell diversification occur on a background of constitutively active molecular machinery necessary for the elaboration of genetic interactions. The essential roles of subsets of such "housekeeping" genes in the regulation of specific aspects of development have become increasingly clear. Pre-mRNA processing is essential for production of functional transcripts by, for example, excision of introns. We have cloned the zebrafish toast(b460) locus and found that it encodes splicing factor 3b, subunit 1 (sf3b1). The sf3b1(b460) mutation causes aberrant splicing of sf3b1 resulting in functional and predicted non-functional transcripts and a 90% reduction in full-length Sf3b1 protein. The sf3b1(b460) mutation was isolated in a mutagenesis screen based on the absence of neural crest-derived melanophores. Further analysis revealed specific earlier defects in neural crest development, whereas the early development of other ectodermal populations appears unaffected. The expression of essential transcriptional regulators of neural crest development are severely disrupted in sf3b1(b460) mutants, due in part to defects in pre-mRNA processing of a subset of these factors, leading to defects in neural crest sublineage specification, survival and migration. Misexpression of a subset of these factors rescues aspects of neural crest development in mutant embryos. Our results indicate that although sf3b1 is a ubiquitously essential gene, the degree to which it is required exhibits tissue-type specificity during early embryogenesis. Further, the developmental defects caused by the sf3b1(b460) mutation provide insights into genetic interactions among members of the gene regulatory network controlling neural crest development. PMID:22562198

  19. Dual labeling of neural crest cells and blood vessels within chicken embryos using Chick(GFP) neural tube grafting and carbocyanine dye DiI injection.

    Science.gov (United States)

    Delalande, Jean-Marie; Thapar, Nikhil; Burns, Alan J

    2015-01-01

    All developing organs need to be connected to both the nervous system (for sensory and motor control) as well as the vascular system (for gas exchange, fluid and nutrient supply). Consequently both the nervous and vascular systems develop alongside each other and share striking similarities in their branching architecture. Here we report embryonic manipulations that allow us to study the simultaneous development of neural crest-derived nervous tissue (in this case the enteric nervous system), and the vascular system. This is achieved by generating chicken chimeras via transplantation of discrete segments of the neural tube, and associated neural crest, combined with vascular DiI injection in the same embryo. Our method uses transgenic chick(GFP) embryos for intraspecies grafting, making the transplant technique more powerful than the classical quail-chick interspecies grafting protocol used with great effect since the 1970s. Chick(GFP)-chick intraspecies grafting facilitates imaging of transplanted cells and their projections in intact tissues, and eliminates any potential bias in cell development linked to species differences. This method takes full advantage of the ease of access of the avian embryo (compared with other vertebrate embryos) to study the co-development of the enteric nervous system and the vascular system. PMID:26065540

  20. Search for the Missing lncs: Gene Regulatory Networks in Neural Crest Development and Long Non-coding RNA Biomarkers of Hirschsprung's Disease

    Science.gov (United States)

    Hirschsprung’s disease (HSCR), a birth defect characterized by variable aganglionosis of the gut, affects about 1 in 5000 births, and is a consequence of abnormal development of neural crest cells, from which enteric ganglia derive. In the companion article in this issue (S...

  1. A novel N-terminal motif is responsible for the evolution of neural crest-specific gene-regulatory activity in vertebrate FoxD3

    Czech Academy of Sciences Publication Activity Database

    Ono, H.; Kozmik, Zbyněk; Yu, J.K.; Wada, H.

    2014-01-01

    Roč. 385, č. 2 (2014), s. 396-404. ISSN 0012-1606 R&D Projects: GA ČR GAP305/10/2141 Institutional support: RVO:68378050 Keywords : neural crest * FoxD3 * amphioxus Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 3.547, year: 2014

  2. Dental anomalies in different cleft groups related to neural crest developmental fields contributes to the understanding of cleft aetiology

    DEFF Research Database (Denmark)

    Riis, Louise Claudius; Kjær, Inger; Mølsted, Kirsten

    2014-01-01

    , radiographs, dental casts, and medical records. PATIENTS: Ninety individuals (30 cleft lip, 30 cleft palate, and 30 combined cleft lip and palate), aged 5-27 years. MAIN OUTCOME MEASURES: Visual evaluation of tooth number and tooth morphology. RESULTS: Cleft lip: Dental deviations were predominantly observed...... in the frontonasal field. Supernumerary lateral incisors occurred significantly more often in cleft lip compared to other cleft types. Cleft palate: Dental deviations were observed in the maxillary and palatal fields indicating that both fields are involved in the development of cleft palate....... Malformed roots were seen significantly more often in cleft palate. Combined cleft lip and palate: Number and type of dental deviations differed significantly from deviations in other cleft types, e.g. significantly more ageneses. CONCLUSIONS: Cleft lip seems to be caused by a disorder in neural crest...

  3. Portable Dynamic Positioning Control System on A Barge in Short-Crested Waves Using the Neural Network Algorithm

    Institute of Scientific and Technical Information of China (English)

    FANG Ming-chung; LEE Zi-yi

    2013-01-01

    This paper develops a nonlinear mathematical model to simulate the dynamic motion behavior of the barge equipped with the portable outboard Dynamic Positioning (DP) system in short-crested waves.The self-tuning Proportional-Derivative (PD) controller based on the neural network algorithm is applied to control the thrusters for optimal adjustment of the barge position in waves.In addition to the wave,the current,the wind and the nonlinear drift force are also considered in the calculations.The time domain simulations for the six-degree-of-freedom motions of the barge with the DP system are solved by the 4th order Runge-Kutta method which can compromise the efficiency and the accuracy of the simulations.The technique of the portable alternative DP system developed here can serve as a practical tool to assist those ships without being equipped with the DP facility while the dynamic positioning missions are needed.

  4. Periconceptional folate consumption is associated with neonatal DNA methylation modifications in neural crest regulatory and cancer development genes.

    Science.gov (United States)

    Gonseth, Semira; Roy, Ritu; Houseman, E Andres; de Smith, Adam J; Zhou, Mi; Lee, Seung-Tae; Nusslé, Sébastien; Singer, Amanda W; Wrensch, Margaret R; Metayer, Catherine; Wiemels, Joseph L

    2015-01-01

    Folate deficiency during early embryonic development constitutes a risk factor for neural tube defects and potentially for childhood leukemia via unknown mechanisms. We tested whether folate consumption during the 12 months prior to conception induced DNA methylation modifications at birth in healthy neonates with a genome-wide and agnostic approach. We hypothesized that DNA methylation in genes involved in neural tube development and/or cancer susceptibility would be affected by folate exposure. We retrospectively assessed folate exposure at the time of conception by food-frequency questionnaires administered to the mothers of 343 healthy newborns. We measured genome-wide DNA methylation from neonatal blood spots. We implemented a method based on bootstrap resampling to decrease false-positive findings. Folate was inversely associated with DNA methylation throughout the genome. Among the top folate-associated genes that were replicated in an independent Gambian study were TFAP2A, a gene critical for neural crest development, STX11, a gene implicated in acute myeloid leukemia, and CYS1, a candidate gene for cystic kidney disease. Reduced periconceptional folate intake was associated with increased methylation and, in turn, decreased gene expression at these 3 loci. The top folate-sensitive genes defined by their associated CpG sites were enriched for numerous transcription factors by Gene Set Enrichment Analysis, including those implicated in cancer development (e.g., MYC-associated zinc finger protein). The influence of estimated periconceptional folate intake on neonatal DNA methylation levels provides potential mechanistic insights into the role of this vitamin in the development of neural tube defects and childhood cancers. PMID:26646725

  5. In Vivo Transplantation of Enteric Neural Crest Cells into Mouse Gut; Engraftment, Functional Integration and Long-Term Safety.

    Directory of Open Access Journals (Sweden)

    Julie E Cooper

    Full Text Available Enteric neuropathies are severe gastrointestinal disorders with unsatisfactory outcomes. We aimed to investigate the potential of enteric neural stem cell therapy approaches for such disorders by transplanting mouse enteric neural crest cells (ENCCs into ganglionic and aganglionic mouse gut in vivo and analysing functional integration and long-term safety.Neurospheres generated from yellow fluorescent protein (YFP expressing ENCCs selected from postnatal Wnt1-cre;R26R-YFP/YFP murine gut were transplanted into ganglionic hindgut of wild-type littermates or aganglionic hindgut of Ednrbtm1Ywa mice (lacking functional endothelin receptor type-B. Intestines were then assessed for ENCC integration and differentiation using immunohistochemistry, cell function using calcium imaging, and long-term safety using PCR to detect off-target YFP expression.YFP+ ENCCs engrafted, proliferated and differentiated into enteric neurons and glia within recipient ganglionic gut. Transplanted cells and their projections spread along the endogenous myenteric plexus to form branching networks. Electrical point stimulation of endogenous nerve fibres resulted in calcium transients (F/F0 = 1.16 ± 0.01;43 cells, n = 6 in YFP+ transplanted ENCCs (abolished with TTX. Long-term follow-up (24 months showed transplanted ENCCs did not give rise to tumours or spread to other organs (PCR negative in extraintestinal sites. In aganglionic gut ENCCs similarly spread and differentiated to form neuronal and glial networks with projections closely associated with endogenous neural networks of the transition zone.Transplanted ENCCs successfully engrafted into recipient ganglionic and aganglionic gut showing appropriate spread, localisation and, importantly, functional integration without any long-term safety issues. This study provides key support for the development and use of enteric neural stem cell therapies.

  6. The Wnt Co-Receptor Lrp5 Is Required for Cranial Neural Crest Cell Migration in Zebrafish.

    Directory of Open Access Journals (Sweden)

    Bernd Willems

    Full Text Available During vertebrate neurulation, cranial neural crest cells (CNCCs undergo epithelial to mesenchymal transition (EMT, delaminate from the neural plate border, and migrate as separate streams into different cranial regions. There, they differentiate into distinct parts of the craniofacial skeleton. Canonical Wnt signaling has been shown to be essential for this process at different levels but the involved receptors remained unclear. Here we show that the frizzled co-receptor low-density-lipoprotein (LDL receptor-related protein 5 (Lrp5 plays a crucial role in CNCC migration and morphogenesis of the cranial skeleton. Early during induction and migration of CNCCs, lrp5 is expressed ubiquitously but later gets restricted to CNCC derivatives in the ventral head region besides different regions in the CNS. A knock-down of lrp5 does not interfere with induction of CNCCs but leads to reduced proliferation of premigratory CNCCs. In addition, cell migration is disrupted as CNCCs are found in clusters at ectopic positions in the dorsomedial neuroepithelium after lrp5 knock-down and transient CRISPR/Cas9 gene editing. These migratory defects consequently result in malformations of the craniofacial skeleton. To date, Lrp5 has mainly been associated with bone homeostasis in mammals. Here we show that in zebrafish, lrp5 also controls cell migration during early morphogenetic processes and contributes to shaping the craniofacial skeleton.

  7. Neural crest migration: interplay between chemorepellents, chemoattractants, contact inhibition, epithelial-mesenchymal transition, and collective cell migration.

    Science.gov (United States)

    Theveneau, Eric; Mayor, Roberto

    2012-01-01

    Neural crest (NC) cells are induced at the border of the neural plate and subsequently leave the neuroepithelium during a delamination phase. This delamination involves either a complete or partial epithelium-to-mesenchyme transition, which is directly followed by an extensive cell migration. During migration, NC cells are exposed to a wide variety of signals controlling their polarity and directionality, allowing them to colonize specific areas or preventing them from invading forbidden zones. For instance, NC cells are restricted to very precise pathways by the presence of inhibitory signals at the borders of each route, such as Semaphorins, Ephrins, and Slit/Robo. Although specific NC chemoattractants have been recently identified, there is evidence that repulsive interactions between the cells, in a process called contact inhibition of locomotion, is one of the major driving forces behind directional migration. Interestingly, in cellular and molecular terms, the invasive behavior of NC is similar to the invasion of cancer cells during metastasis. NC cells eventually settle in various places and make an immense contribution to the vertebrate body. They form the major constituents of the skull, the peripheral nervous system, and the pigment cells among others, which show the remarkable diversity and importance of this embryonic-stem cell like cell population. Consequently, several birth defects and craniofacial disorders, such as Treacher Collins syndrome, are due to improper NC cell migration. PMID:23801492

  8. Effects of 13 developmentally toxic chemicals on the migration of rat cephalic neural crest cells in vitro.

    Science.gov (United States)

    Usami, Makoto; Mitsunaga, Katsuyoshi; Miyajima, Atsuko; Takamatu, Mina; Kazama, Shugo; Irie, Tomohiko; Doi, Osamu; Takizawa, Tatsuya

    2016-03-01

    The inhibition of neural crest cell (NCC) migration has been considered as a possible pathogenic mechanism underlying chemical developmental toxicity. In this study, we examined the effects of 13 developmentally toxic chemicals on the migration of rat cephalic NCCs (cNCCs) by using a simple in vitro assay. cNCCs were cultured for 48 h as emigrants from rhombencephalic neural tubes explanted from rat embryos at day 10.5 of gestation. The chemicals were added to the culture medium at 24 h of culture. Migration of cNCCs was measured as the change in the radius (radius ratio) calculated from the circular spread of cNCCs between 24 and 48 h of culture. Of the chemicals examined, 13-cis-retinoic acid, ethanol, ibuprofen, lead acetate, salicylic acid, and selenate inhibited the migration of cNCCs at their embryotoxic concentrations; no effects were observed for acetaminophen, caffeine, indium, phenytoin, selenite, tributyltin, and valproic acid. In a cNCC proliferation assay, ethanol, ibuprofen, salicylic acid, selenate, and tributyltin inhibited cell proliferation, suggesting the contribution of the reduced cell number to the inhibited migration of cNCCs. It was determined that several developmentally toxic chemicals inhibited the migration of cNCCs, the effects of which were manifested as various craniofacial abnormalities. PMID:26175014

  9. Fibulin-1 is required for morphogenesis of neural crest-derived structures

    OpenAIRE

    Cooley, Marion A.; Kern, Christine B.; Fresco, Victor M.; Wessels, Andy; Thompson, Robert P.; McQuinn, Tim C.; Twal, Waleed O.; Mjaatvedt, Corey H.; Drake, Christopher J.; Argraves, W Scott

    2008-01-01

    Here we report that mouse embryos homozygous for a gene trap insertion in the fibulin-1 (Fbln1) gene are deficient in Fbln1 and exhibit cardiac ventricular wall thinning and ventricular septal defects with double outlet right ventricle or overriding aorta. Fbln1 nulls also display anomalies of aortic arch arteries, hypoplasia of the thymus and thyroid, underdeveloped skull bones, malformations of cranial nerves and hemorrhagic blood vessels in the head and neck. The spectrum of malformations ...

  10. Impaired Cellular Immunity in the Murine Neural Crest Conditional Deletion of Endothelin Receptor-B Model of Hirschsprung's Disease.

    Directory of Open Access Journals (Sweden)

    Ankush Gosain

    Full Text Available Hirschsprung's disease (HSCR is characterized by aganglionosis from failure of neural crest cell (NCC migration to the distal hindgut. Up to 40% of HSCR patients suffer Hirschsprung's-associated enterocolitis (HAEC, with an incidence that is unchanged from the pre-operative to the post-operative state. Recent reports indicate that signaling pathways involved in NCC migration may also be involved in the development of secondary lymphoid organs. We hypothesize that gastrointestinal (GI mucosal immune defects occur in HSCR that may contribute to enterocolitis. EdnrB was deleted from the neural crest (EdnrBNCC-/- resulting in mutants with defective NCC migration, distal colonic aganglionosis and the development of enterocolitis. The mucosal immune apparatus of these mice was interrogated at post-natal day (P 21-24, prior to histological signs of enterocolitis. We found that EdnrBNCC-/- display lymphopenia of their Peyer's Patches, the major inductive site of GI mucosal immunity. EdnrBNCC-/- Peyer's Patches demonstrate decreased B-lymphocytes, specifically IgM+IgDhi (Mature B-lymphocytes, which are normally activated and produce IgA following antigen presentation. EdnrBNCC-/- animals demonstrate decreased small intestinal secretory IgA, but unchanged nasal and bronchial airway secretory IgA, indicating a gut-specific defect in IgA production or secretion. In the spleen, which is the primary source of IgA-producing Mature B-lymphocytes, EdnrBNCC-/- animals display decreased B-lymphocytes, but an increase in Mature B-lymphocytes. EdnrBNCC-/- spleens are also small and show altered architecture, with decreased red pulp and a paucity of B-lymphocytes in the germinal centers and marginal zone. Taken together, these findings suggest impaired GI mucosal immunity in EdnrBNCC-/- animals, with the spleen as a potential site of the defect. These findings build upon the growing body of literature that suggests that intestinal defects in HSCR are not restricted

  11. Multipotent skin-derived precursors: adult neural crest-related precursors with therapeutic potential

    OpenAIRE

    Fernandes, Karl J.L; Toma, Jean G; Miller, Freda D.

    2007-01-01

    We previously made the surprising finding that cultures of multipotent precursors can be grown from the dermis of neonatal and adult mammalian skin. These skin-derived precursors (SKPs) display multi-lineage differentiation potential, producing both neural and mesodermal progeny in vitro, and are an apparently novel precursor cell type that is distinct from other known precursors within the skin. In this review, we begin by placing these findings within the context of the rapidly evolving ste...

  12. Adult bone marrow mesenchymal and neural crest stem cells are chemoattractive and accelerate motor recovery in a mouse model of spinal cord injury

    OpenAIRE

    Neirinckx, Virginie; Agirman, Gulistan; Coste, Cécile; Marquet, Alice; Dion, Valérie; Rogister, Bernard; Franzen, Rachelle; Wislet, Sabine

    2015-01-01

    Introduction Stem cells from adult tissues were considered for a long time as promising tools for regenerative therapy of neurological diseases, including spinal cord injuries (SCI). Indeed, mesenchymal (MSCs) and neural crest stem cells (NCSCs) together constitute the bone marrow stromal stem cells (BMSCs) that were used as therapeutic options in various models of experimental SCI. However, as clinical approaches remained disappointing, we thought that reducing BMSC heterogeneity should be a...

  13. Delamination of neural crest cells requires transient and reversible Wnt inhibition mediated by Dact1/2.

    Science.gov (United States)

    Rabadán, M Angeles; Herrera, Antonio; Fanlo, Lucia; Usieto, Susana; Carmona-Fontaine, Carlos; Barriga, Elias H; Mayor, Roberto; Pons, Sebastián; Martí, Elisa

    2016-06-15

    Delamination of neural crest (NC) cells is a bona fide physiological model of epithelial-to-mesenchymal transition (EMT), a process that is influenced by Wnt/β-catenin signalling. Using two in vivo models, we show that Wnt/β-catenin signalling is transiently inhibited at the time of NC delamination. In attempting to define the mechanism underlying this inhibition, we found that the scaffold proteins Dact1 and Dact2, which are expressed in pre-migratory NC cells, are required for NC delamination in Xenopus and chick embryos, whereas they do not affect the motile properties of migratory NC cells. Dact1/2 inhibit Wnt/β-catenin signalling upstream of the transcriptional activity of T cell factor (TCF), which is required for EMT to proceed. Dact1/2 regulate the subcellular distribution of β-catenin, preventing β-catenin from acting as a transcriptional co-activator to TCF, yet without affecting its stability. Together, these data identify a novel yet important regulatory element that inhibits β-catenin signalling, which then affects NC delamination. PMID:27122165

  14. Mesenchymal stem cells and neural crest stem cells from adult bone marrow: characterization of their surprising similarities and differences.

    Science.gov (United States)

    Wislet-Gendebien, Sabine; Laudet, Emerence; Neirinckx, Virginie; Alix, Philippe; Leprince, Pierre; Glejzer, Aneta; Poulet, Christophe; Hennuy, Benoit; Sommer, Lukas; Shakhova, Olga; Rogister, Bernard

    2012-08-01

    The generation of neuronal cells from stem cells obtained from adult bone marrow is of significant clinical interest in order to design new cell therapy protocols for several neurological disorders. The recent identification in adult bone marrow of stem cells derived from the neural crest stem cells (NCSC) might explain the neuronal phenotypic plasticity shown by bone marrow cells. However, little information is available about the nature of these cells compared to mesenchymal stem cells (MSC), including their similarities and differences. In this paper, using transcriptomic as well as proteomic technologies, we compared NCSC to MSC and stromal nestin-positive cells, all of them isolated from adult bone marrow. We demonstrated that the nestin-positive cell population, which was the first to be described as able to differentiate into functional neurons, was a mixed population of NCSC and MSC. More interestingly, we demonstrated that MSC shared with NCSC the same ability to truly differentiate into Tuj1-positive cells when co-cultivated with paraformaldehyde-fixed cerebellar granule neurons. Altogether, those results suggest that both NCSC and MSC can be considered as important tools for cellular therapies in order to replace neurons in various neurological diseases. PMID:22349262

  15. Interaction of adult human neural crest-derived stem cells with a nanoporous titanium surface is sufficient to induce their osteogenic differentiation

    Directory of Open Access Journals (Sweden)

    Matthias Schürmann

    2014-07-01

    Full Text Available Osteogenic differentiation of various adult stem cell populations such as neural crest-derived stem cells is of great interest in the context of bone regeneration. Ideally, exogenous differentiation should mimic an endogenous differentiation process, which is partly mediated by topological cues. To elucidate the osteoinductive potential of porous substrates with different pore diameters (30 nm, 100 nm, human neural crest-derived stem cells isolated from the inferior nasal turbinate were cultivated on the surface of nanoporous titanium covered membranes without additional chemical or biological osteoinductive cues. As controls, flat titanium without any topological features and osteogenic medium was used. Cultivation of human neural crest-derived stem cells on 30 nm pores resulted in osteogenic differentiation as demonstrated by alkaline phosphatase activity after seven days as well as by calcium deposition after 3 weeks of cultivation. In contrast, cultivation on flat titanium and on membranes equipped with 100 nm pores was not sufficient to induce osteogenic differentiation. Moreover, we demonstrate an increase of osteogenic transcripts including Osterix, Osteocalcin and up-regulation of Integrin β1 and α2 in the 30 nm pore approach only. Thus, transplantation of stem cells pre-cultivated on nanostructured implants might improve the clinical outcome by support of the graft adherence and acceleration of the regeneration process.

  16. Novel migrating mouse neural crest cell assay system utilizing P0-Cre/EGFP fluorescent time-lapse imaging

    Directory of Open Access Journals (Sweden)

    Kawakami Minoru

    2011-11-01

    Full Text Available Abstract Background Neural crest cells (NCCs are embryonic, multipotent stem cells. Their long-range and precision-guided migration is one of their most striking characteristics. We previously reported that P0-Cre/CAG-CAT-lacZ double-transgenic mice showed significant lacZ expression in tissues derived from NCCs. Results In this study, by embedding a P0-Cre/CAG-CAT-EGFP embryo at E9.5 in collagen gel inside a culture glass slide, we were able to keep the embryo developing ex vivo for more than 24 hours; this development was with enough NCC fluorescent signal intensity to enable single-cell resolution analysis, with the accompanying NCC migration potential intact and with the appropriate NCC response to the extracellular signal maintained. By implantation of beads with absorbed platelet-derived growth factor-AA (PDGF-AA, we demonstrated that PDGF-AA acts as an NCC-attractant in embryos. We also performed assays with NCCs isolated from P0-Cre/CAG-CAT-EGFP embryos on culture plates. The neuromediator 5-hydroxytryptamine (5-HT has been known to regulate NCC migration. We newly demonstrated that dopamine, in addition to 5-HT, stimulated NCC migration in vitro. Two NCC populations, with different axial levels of origins, showed unique distribution patterns regarding migration velocity and different dose-response patterns to both 5-HT and dopamine. Conclusions Although avian species predominated over the other species in the NCC study, our novel system should enable us to use mice to assay many different aspects of NCCs in embryos or on culture plates, such as migration, division, differentiation, and apoptosis.

  17. Cardiac neural crest ablation inhibits compaction and electrical function of conduction system bundles

    Czech Academy of Sciences Publication Activity Database

    Gurjarpadhye, A.; Hewett, K. W.; Justus, C.; Wen, X.; Stadt, H.; Kirby, M. L.; Sedmera, David; Gourdie, R. G.

    2007-01-01

    Roč. 292, - (2007), H1291-H1300. ISSN 0363-6135 Institutional research plan: CEZ:AV0Z50450515 Keywords : conduction system Subject RIV: FA - Cardiovascular Diseases incl. Cardiotharic Surgery Impact factor: 3.973, year: 2007

  18. In vitro cementoblast-like differentiation of postmigratory neural crest-derived p75{sup +} stem cells with dental follicle cell conditioned medium

    Energy Technology Data Exchange (ETDEWEB)

    Wen, Xiujie; Liu, Luchuan; Deng, Manjing; Liu, Rui; Zhang, Li; Nie, Xin, E-mail: dr.xinnie@gmail.com

    2015-09-10

    Cranial neural crest-derived cells (CNCCs) play important role in epithelial–mesenchymal interactions during tooth morphogenesis. However, the heterogeneity of CNCCs and their tendency to spontaneously differentiate along smooth muscle or osteoblast lineages in vitro limit further understanding of their biological properties. We studied the differentiation properties of isolated rat embryonic postmigratory CNCCs, expressing p75 neurotrophin receptor (p75NTR). These p75NTR positive (p75{sup +}) CNCCs, isolated using fluorescence activated cell sorter, exhibited fibroblast-like morphology and characteristics of mesenchymal stem cells. Incubation of p75{sup +} CNCCs in dental follicle cell conditioned medium (DFCCM) combined with dentin non-collagenous proteins (dNCPs), altered their morphological features to cementoblast-like appearance. These cells also showed low proliferative activity, high ALP activity and significantly increased calcified nodule formation. Markers related to mineralization or specific to cementoblast lineage were highly expressed in dNCPs/DFCCM-treated p75{sup +} cells, suggesting their differentiation along cementoblast-like lineage. p75{sup +} stem cells selected from postmigratory CNCCs represent a pure stem cell population and could be used as a stem cell model for in vitro studies due to their intrinsic ability to differentiate to neuronal cells and transform from neuroectoderm to ectomesenchyme. They can provide a potential stem cell resource for tooth engineering studies and help to further investigate mechanisms of epithelial–mesenchymal interactions in tooth morphogenesis. - Highlights: • Cranial neural crest-derived cells (CNCCs) take part in tooth morphogenesis. • positive (p75{sup +}) CNCCs are fibroblast-like and resemble mesenchymal stem cells. • p75{sup +} CNCCs in dental follicle cell medium (DFCCM/dNCP) appear like cementoblasts. • DFCCM/dNCP-treated p75{sup +} cells express cementoblast specific mineralization

  19. Derivation of Schwann cell precursors from neural crest cells resident in bone marrow for cell therapy to improve peripheral nerve regeneration.

    Science.gov (United States)

    Shi, Haiyan; Gong, Yanpei; Qiang, Liang; Li, Xiaoli; Zhang, Shibo; Gao, Jiawen; Li, Kai; Ji, Ximeng; Tian, Ling; Gu, Xiaosong; Ding, Fei

    2016-05-01

    We have previously successfully enriched post-migratory neural crest cells (NCCs) from postnatal rat bone marrow (BM). These BM-NCCs possess glial and neuronal differentiating potential. Based on the neural crest origin of Schwann cells (SCs), in this study, we aimed at using a straightforward protocol to derive Schwann cell precursors (SCPs) from BM-NCCs. Several clonal subpopulations were isolated from BM-NCCs, displaying long-term proliferative capacity and maintaining the NCC identity. The BM-NCC clones could be induced to differentiate into SCs. In particular, clone N1 gave rise to a large and pure population of SCs. Clone N1-derived SCs demonstrated the myelinating capacity in their co-culture with primary dorsal root ganglion (DRG) neurons. The decreased expression of NCC-markers and increased expression of SC-markers were related to the differentiation state of clone N1-derived SCs. To investigate the repair-promoting effects of clone N1 on injured peripheral neurons in vitro and in vivo, on one hand, the oxygen glucose deprivation-injured DRG neurons were treated with clone N1-conditioned medium, improving the cell survival and axon growth of neurons; on the other hand, clone N1 or clone N1-derived SCs were respectively implanted to the crush sciatic nerve of rats, and clone N1 yielded the better outcome of nerve regeneration and function restoration than clone N1-derived SCs. Taken together, all the results collectively showed that clone N1 could be identified as SCPs, which might hold promise for cell therapy to improve peripheral nerve regeneration. PMID:26946403

  20. Heterochronic shift between early organogenesis and migration of cephalic neural crest cells in two divergent evolutionary phenotypes of archosaurs: crocodile and ostrich.

    Science.gov (United States)

    Kundrát, Martin

    2009-01-01

    Living archosaurs (crocodiles and birds) represent an intriguing evo-devo model system. Although close in phylogenetic relationship, the two lineages show considerable divergence in trends of phenotypic evolution. The head anatomy of recent crocodilians has changed little in comparison with that of their crocodylomorph ancestors. The head phenotype of the avians (birds), as well as some non-avian theropods, shows numerous evolutionary innovations that differ considerably from the crocodylomorph pattern. Most of the novel head structures, such as features of the craniofacial skeleton, cranial nerves, head muscles, and integument are derived from the same cellular source common to all archosaurs, the cephalic neural crest (CNC). Therefore, other factors must be involved in the developmental disparity of homologous structures in the aforementioned lineages. The present study analyzes the earliest developmental events that are associated with the appearance of the neural crest cells in the two archosaur models: Crocodylus niloticus and Struthio camelus. I found that both models share unique developmental features, the presence of an unpaired, rostrally migrating population of CNC cells, showing that the two are closely related to each other. On the other hand, the crocodile and the ostrich differ substantially in (1) timing, (2) duration, and (3) expression patterns of the CNC. Compared with the crocodile, the CNC cells in the ostrich (1) migrate much later into the embryonic head, (2) but relocate to their terminal positions faster, and (3) take specifically directed migratory routes in the mandibular/oral region and head/trunk-interface regions. I suggest that accelerated relocation of CNC cells combined with delayed head organogenesis may represent important innovative conditions in the developmental evolution of a new archosaur head phenotype. PMID:19754710

  1. In vitro cementoblast-like differentiation of postmigratory neural crest-derived p75+ stem cells with dental follicle cell conditioned medium

    International Nuclear Information System (INIS)

    Cranial neural crest-derived cells (CNCCs) play important role in epithelial–mesenchymal interactions during tooth morphogenesis. However, the heterogeneity of CNCCs and their tendency to spontaneously differentiate along smooth muscle or osteoblast lineages in vitro limit further understanding of their biological properties. We studied the differentiation properties of isolated rat embryonic postmigratory CNCCs, expressing p75 neurotrophin receptor (p75NTR). These p75NTR positive (p75+) CNCCs, isolated using fluorescence activated cell sorter, exhibited fibroblast-like morphology and characteristics of mesenchymal stem cells. Incubation of p75+ CNCCs in dental follicle cell conditioned medium (DFCCM) combined with dentin non-collagenous proteins (dNCPs), altered their morphological features to cementoblast-like appearance. These cells also showed low proliferative activity, high ALP activity and significantly increased calcified nodule formation. Markers related to mineralization or specific to cementoblast lineage were highly expressed in dNCPs/DFCCM-treated p75+ cells, suggesting their differentiation along cementoblast-like lineage. p75+ stem cells selected from postmigratory CNCCs represent a pure stem cell population and could be used as a stem cell model for in vitro studies due to their intrinsic ability to differentiate to neuronal cells and transform from neuroectoderm to ectomesenchyme. They can provide a potential stem cell resource for tooth engineering studies and help to further investigate mechanisms of epithelial–mesenchymal interactions in tooth morphogenesis. - Highlights: • Cranial neural crest-derived cells (CNCCs) take part in tooth morphogenesis. • positive (p75+) CNCCs are fibroblast-like and resemble mesenchymal stem cells. • p75+ CNCCs in dental follicle cell medium (DFCCM/dNCP) appear like cementoblasts. • DFCCM/dNCP-treated p75+ cells express cementoblast specific mineralization markers. • p75+ cells are pure stem cells and

  2. EGF–FGF2 stimulates the proliferation and improves the neuronal commitment of mouse epidermal neural crest stem cells (EPI-NCSCs)

    International Nuclear Information System (INIS)

    Epidermal neural crest stem cells (EPI-NCSCs), which reside in the bulge of hair follicles, are attractive candidates for several applications in cell therapy, drug screening and tissue engineering. As suggested remnants of the embryonic neural crest (NC) in an adult location, EPI-NCSCs are able to generate a wide variety of cell types and are readily accessible by a minimally invasive procedure. Since the combination of epidermal growth factor (EGF) and fibroblast growth factor type 2 (FGF2) is mitogenic and promotes the neuronal commitment of various stem cell populations, we examined its effects in the proliferation and neuronal potential of mouse EPI-NCSCs. By using a recognized culture protocol of bulge whiskers follicles, we were able to isolate a population of EPI-NCSCs, characterized by the migratory potential, cell morphology and expression of phenotypic markers of NC cells. EPI-NCSCs expressed neuronal, glial and smooth muscle markers and exhibited the NC-like fibroblastic morphology. The treatment with the combination EGF and FGF2, however, increased their proliferation rate and promoted the acquisition of a neuronal-like morphology accompanied by reorganization of neural cytoskeletal proteins βIII-tubulin and nestin, as well as upregulation of the pan neuronal marker βIII-tubulin and down regulation of the undifferentiated NC, glial and smooth muscle cell markers. Moreover, the treatment enhanced the response of EPI-NCSCs to neurogenic stimulation, as evidenced by induction of GAP43, and increased expression of Mash-1 in neuron-like cell, both neuronal-specific proteins. Together, the results suggest that the combination of EGF–FGF2 stimulates the proliferation and improves the neuronal potential of EPI-NCSCs similarly to embryonic NC cells, ES cells and neural progenitor/stem cells of the central nervous system and highlights the advantage of using EGF–FGF2 in neuronal differentiation protocols. - Highlights: • EPI-NCSCs express

  3. EGF–FGF{sub 2} stimulates the proliferation and improves the neuronal commitment of mouse epidermal neural crest stem cells (EPI-NCSCs)

    Energy Technology Data Exchange (ETDEWEB)

    Bressan, Raul Bardini; Melo, Fernanda Rosene; Almeida, Patricia Alves; Bittencourt, Denise Avani; Visoni, Silvia; Jeremias, Talita Silva [Departamento de Biologia Celular, Embriologia e Genética, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina, Campus Universitário – Trindade, 88040-900 Florianópolis SC (Brazil); Costa, Ana Paula; Leal, Rodrigo Bainy [Departamento de Bioquímica, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina, Campus Universitário – Trindade, 88040-900 Florianópolis SC (Brazil); Trentin, Andrea Gonçalves, E-mail: andrea.trentin@ufsc.br [Departamento de Biologia Celular, Embriologia e Genética, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina, Campus Universitário – Trindade, 88040-900 Florianópolis SC (Brazil)

    2014-09-10

    Epidermal neural crest stem cells (EPI-NCSCs), which reside in the bulge of hair follicles, are attractive candidates for several applications in cell therapy, drug screening and tissue engineering. As suggested remnants of the embryonic neural crest (NC) in an adult location, EPI-NCSCs are able to generate a wide variety of cell types and are readily accessible by a minimally invasive procedure. Since the combination of epidermal growth factor (EGF) and fibroblast growth factor type 2 (FGF{sub 2}) is mitogenic and promotes the neuronal commitment of various stem cell populations, we examined its effects in the proliferation and neuronal potential of mouse EPI-NCSCs. By using a recognized culture protocol of bulge whiskers follicles, we were able to isolate a population of EPI-NCSCs, characterized by the migratory potential, cell morphology and expression of phenotypic markers of NC cells. EPI-NCSCs expressed neuronal, glial and smooth muscle markers and exhibited the NC-like fibroblastic morphology. The treatment with the combination EGF and FGF{sub 2}, however, increased their proliferation rate and promoted the acquisition of a neuronal-like morphology accompanied by reorganization of neural cytoskeletal proteins βIII-tubulin and nestin, as well as upregulation of the pan neuronal marker βIII-tubulin and down regulation of the undifferentiated NC, glial and smooth muscle cell markers. Moreover, the treatment enhanced the response of EPI-NCSCs to neurogenic stimulation, as evidenced by induction of GAP43, and increased expression of Mash-1 in neuron-like cell, both neuronal-specific proteins. Together, the results suggest that the combination of EGF–FGF2 stimulates the proliferation and improves the neuronal potential of EPI-NCSCs similarly to embryonic NC cells, ES cells and neural progenitor/stem cells of the central nervous system and highlights the advantage of using EGF–FGF{sub 2} in neuronal differentiation protocols. - Highlights: • EPI

  4. CREST Syndrome

    Directory of Open Access Journals (Sweden)

    Tuğçe Köksüz

    2014-06-01

    Full Text Available We report a case of CREST syndrome (calsinosis cutis, Raynaud’s phenomenon, oesophageal dysmotility, sclerodactyly and telangiectasia with all of the five major symptoms. A 46-year-old woman was admitted to our clinic with the complaint of erythema, rigidity and pain on the plantar surface of the feet. She had had Raynaud’s phenomenon for 20 years and oesophageal reflux for five years. Her face had become masklike and there was prominent telangiectasies on her face and hands. Sclerosis were confined to the fingers (sclerodactyly. Direct X-ray graphy demonstrated calcinosis cutis on the left hand and suprapatellar region. She was treated with nifedipine 30 mg/day, acetylsalicylic acid 100 mg/day for Raynaud’s phenomenon and famotidine 40 mg/day, metoclopramide HCL 30 mg/day for oesophageal dysmotility. Her complaints were partially relieved after the treatment. This case had all of the five major symptoms of CREST syndrome, and we aimed to emphasize the major symptoms and complications of CREST syndrome. (Turk J Dermatol 2012; 6: 48-50

  5. The ubiquitin ligase Nedd4 regulates craniofacial development by promoting cranial neural crest cell survival and stem-cell like properties.

    Science.gov (United States)

    Wiszniak, Sophie; Kabbara, Samuela; Lumb, Rachael; Scherer, Michaela; Secker, Genevieve; Harvey, Natasha; Kumar, Sharad; Schwarz, Quenten

    2013-11-15

    The integration of multiple morphogenic signalling pathways and transcription factor networks is essential to mediate neural crest (NC) cell induction, delamination, survival, stem-cell properties, fate choice and differentiation. Although the transcriptional control of NC development is well documented in mammals, the role of post-transcriptional modifications, and in particular ubiquitination, has not been explored. Here we report an essential role for the ubiquitin ligase Nedd4 in cranial NC cell development. Our analysis of Nedd4(-/-) embryos identified profound deficiency of cranial NC cells in the absence of structural defects in the neural tube. Nedd4 is expressed in migrating cranial NC cells and was found to positively regulate expression of the NC transcription factors Sox9, Sox10 and FoxD3. We found that in the absence of these factors, a subset of cranial NC cells undergo apoptosis. In accordance with a lack of cranial NC cells, Nedd4(-/-) embryos have deficiency of the trigeminal ganglia, NC derived bone and malformation of the craniofacial skeleton. Our analyses therefore uncover an essential role for Nedd4 in a subset of cranial NC cells and highlight E3 ubiquitin ligases as a likely point of convergence for multiple NC signalling pathways and transcription factor networks. PMID:24080509

  6. CREST Syndrome

    OpenAIRE

    Tuğçe Köksüz; Zeynep Nurhan Saraçoğlu; Ayşe Esra Koku-Aksu; İlham Sabuncu; Cengiz Korkmaz

    2014-01-01

    We report a case of CREST syndrome (calsinosis cutis, Raynaud’s phenomenon, oesophageal dysmotility, sclerodactyly and telangiectasia) with all of the five major symptoms. A 46-year-old woman was admitted to our clinic with the complaint of erythema, rigidity and pain on the plantar surface of the feet. She had had Raynaud’s phenomenon for 20 years and oesophageal reflux for five years. Her face had become masklike and there was prominent telangiectasies on her face and hands. Sclerosis were ...

  7. Impaired Cellular Immunity in the Murine Neural Crest Conditional Deletion of Endothelin Receptor-B Model of Hirschsprung’s Disease

    Science.gov (United States)

    Gosain, Ankush; Barlow-Anacker, Amanda J.; Erickson, Chris S.; Pierre, Joseph F.; Heneghan, Aaron F.; Epstein, Miles L.; Kudsk, Kenneth A.

    2015-01-01

    Hirschsprung’s disease (HSCR) is characterized by aganglionosis from failure of neural crest cell (NCC) migration to the distal hindgut. Up to 40% of HSCR patients suffer Hirschsprung’s-associated enterocolitis (HAEC), with an incidence that is unchanged from the pre-operative to the post-operative state. Recent reports indicate that signaling pathways involved in NCC migration may also be involved in the development of secondary lymphoid organs. We hypothesize that gastrointestinal (GI) mucosal immune defects occur in HSCR that may contribute to enterocolitis. EdnrB was deleted from the neural crest (EdnrBNCC-/-) resulting in mutants with defective NCC migration, distal colonic aganglionosis and the development of enterocolitis. The mucosal immune apparatus of these mice was interrogated at post-natal day (P) 21–24, prior to histological signs of enterocolitis. We found that EdnrBNCC-/- display lymphopenia of their Peyer’s Patches, the major inductive site of GI mucosal immunity. EdnrBNCC-/- Peyer’s Patches demonstrate decreased B-lymphocytes, specifically IgM+IgDhi (Mature) B-lymphocytes, which are normally activated and produce IgA following antigen presentation. EdnrBNCC-/- animals demonstrate decreased small intestinal secretory IgA, but unchanged nasal and bronchial airway secretory IgA, indicating a gut-specific defect in IgA production or secretion. In the spleen, which is the primary source of IgA-producing Mature B-lymphocytes, EdnrBNCC-/- animals display decreased B-lymphocytes, but an increase in Mature B-lymphocytes. EdnrBNCC-/- spleens are also small and show altered architecture, with decreased red pulp and a paucity of B-lymphocytes in the germinal centers and marginal zone. Taken together, these findings suggest impaired GI mucosal immunity in EdnrBNCC-/- animals, with the spleen as a potential site of the defect. These findings build upon the growing body of literature that suggests that intestinal defects in HSCR are not restricted to

  8. The retinoic acid signaling pathway regulates anterior/posterior patterning in the nerve cord and pharynx of amphioxus, a chordate lacking neural crest

    Science.gov (United States)

    Escriva, Hector; Holland, Nicholas D.; Gronemeyer, Hinrich; Laudet, Vincent; Holland, Linda Z.

    2002-01-01

    Amphioxus, the closest living invertebrate relative of the vertebrates, has a notochord, segmental axial musculature, pharyngeal gill slits and dorsal hollow nerve cord, but lacks neural crest. In amphioxus, as in vertebrates, exogenous retinoic acid (RA) posteriorizes the embryo. The mouth and gill slits never form, AmphiPax1, which is normally downregulated where gill slits form, remains upregulated and AmphiHox1 expression shifts anteriorly in the nerve cord. To dissect the role of RA signaling in patterning chordate embryos, we have cloned the single retinoic acid receptor (AmphiRAR), retinoid X receptor (AmphiRXR) and an orphan receptor (AmphiTR2/4) from amphioxus. AmphiTR2/4 inhibits AmphiRAR-AmphiRXR-mediated transactivation in the presence of RA by competing for DR5 or IR7 retinoic acid response elements (RAREs). The 5' untranslated region of AmphiTR2/4 contains an IR7 element, suggesting possible auto- and RA-regulation. The patterns of AmphiTR2/4 and AmphiRAR expression during embryogenesis are largely complementary: AmphiTR2/4 is strongly expressed in the cerebral vesicle (homologous to the diencephalon plus anterior midbrain), while AmphiRAR expression is high in the equivalent of the hindbrain and spinal cord. Similarly, while AmphiTR2/4 is expressed most strongly in the anterior and posterior thirds of the endoderm, the highest AmphiRAR expression is in the middle third. Expression of AmphiRAR is upregulated by exogenous RA and completely downregulated by the RA antagonist BMS009. Moreover, BMS009 expands the pharynx posteriorly; the first three gill slit primordia are elongated and shifted posteriorly, but do not penetrate, and additional, non-penetrating gill slit primordia are induced. Thus, in an organism without neural crest, initiation and penetration of gill slits appear to be separate events mediated by distinct levels of RA signaling in the pharyngeal endoderm. Although these compounds have little effect on levels of AmphiTR2/4 expression, RA

  9. Neural crest migration is driven by a few trailblazer cells with a unique molecular signature narrowly confined to the invasive front.

    Science.gov (United States)

    McLennan, Rebecca; Schumacher, Linus J; Morrison, Jason A; Teddy, Jessica M; Ridenour, Dennis A; Box, Andrew C; Semerad, Craig L; Li, Hua; McDowell, William; Kay, David; Maini, Philip K; Baker, Ruth E; Kulesa, Paul M

    2015-06-01

    Neural crest (NC) cell migration is crucial to the formation of peripheral tissues during vertebrate development. However, how NC cells respond to different microenvironments to maintain persistence of direction and cohesion in multicellular streams remains unclear. To address this, we profiled eight subregions of a typical cranial NC cell migratory stream. Hierarchical clustering showed significant differences in the expression profiles of the lead three subregions compared with newly emerged cells. Multiplexed imaging of mRNA expression using fluorescent hybridization chain reaction (HCR) quantitatively confirmed the expression profiles of lead cells. Computational modeling predicted that a small fraction of lead cells that detect directional information is optimal for successful stream migration. Single-cell profiling then revealed a unique molecular signature that is consistent and stable over time in a subset of lead cells within the most advanced portion of the migratory front, which we term trailblazers. Model simulations that forced a lead cell behavior in the trailing subpopulation predicted cell bunching near the migratory domain entrance. Misexpression of the trailblazer molecular signature by perturbation of two upstream transcription factors agreed with the in silico prediction and showed alterations to NC cell migration distance and stream shape. These data are the first to characterize the molecular diversity within an NC cell migratory stream and offer insights into how molecular patterns are transduced into cell behaviors. PMID:25977364

  10. Decreased proliferative, migrative and neuro-differentiative potential of postnatal rat enteric neural crest-derived cells during culture in vitro.

    Science.gov (United States)

    Yu, Hui; Pan, Wei-Kang; Zheng, Bai-Jun; Wang, Huai-Jie; Chen, Xin-Lin; Liu, Yong; Gao, Ya

    2016-05-01

    A growing body of evidence supports the potential use of enteric neural crest-derived cells (ENCCs) as a cell replacement therapy for Hirschsprung's disease. Based on previous observations of robust propagation of primary ENCCs, as opposed to their progeny, it is suggested that their therapeutic potential after in vitro expansion may be restricted. We therefore examined the growth and differentiation activities and phenotypic characteristics of continuous ENCC cultures. ENCCs were isolated from the intestines of postnatal rats and were identified using an immunocytochemical approach. During continuous ENCC culture expansion, proliferation, migration, apoptosis, and differentiation potentials were monitored. The Cell Counting Kit-8 was used for assessment of ENCC vitality, Transwell inserts for cell migration, immunocytochemistry for cell counts and identification, and flow cytometry for apoptosis. Over six continuous generations, ENCC proliferation potency was reduced and with prolonged culture, the ratio of migratory ENCCs was decreased. The percentage of apoptosis showed an upward trend with prolonged intragenerational culture, but showed a downward trend with prolonged culture of combined generations. Furthermore, the percentage of peripherin(+) cells decreased whilst the percentage of GFAP(+) cells increased with age. The results demonstrated that alterations in ENCC growth characteristics occur with increased culture time, which may partially account for the poor results of proposed cell therapies. PMID:27068376

  11. FGF8 signaling sustains progenitor status and multipotency of cranial neural crest-derived mesenchymal cells in vivo and in vitro.

    Science.gov (United States)

    Shao, Meiying; Liu, Chao; Song, Yingnan; Ye, Wenduo; He, Wei; Yuan, Guohua; Gu, Shuping; Lin, Congxin; Ma, Liang; Zhang, Yanding; Tian, Weidong; Hu, Tao; Chen, YiPing

    2015-10-01

    The cranial neural crest (CNC) cells play a vital role in craniofacial development and regeneration. They are multi-potent progenitors, being able to differentiate into various types of tissues. Both pre-migratory and post-migratory CNC cells are plastic, taking on diverse fates by responding to different inductive signals. However, what sustains the multipotency of CNC cells and derivatives remains largely unknown. In this study, we present evidence that FGF8 signaling is able to sustain progenitor status and multipotency of CNC-derived mesenchymal cells both in vivo and in vitro. We show that augmented FGF8 signaling in pre-migratory CNC cells prevents cell differentiation and organogenesis in the craniofacial region by maintaining their progenitor status. CNC-derived mesenchymal cells with Fgf8 overexpression or control cells in the presence of exogenous FGF8 exhibit prolonged survival, proliferation, and multi-potent differentiation capability in cell cultures. Remarkably, exogenous FGF8 also sustains the capability of CNC-derived mesenchymal cells to participate in organogenesis such as odontogenesis. Furthermore, FGF8-mediated signaling strongly promotes adipogenesis but inhibits osteogenesis of CNC-derived mesenchymal cells in vitro. Our results reveal a specific role for FGF8 in the maintenance of progenitor status and in fate determination of CNC cells, implicating a potential application in expansion and fate manipulation of CNC-derived cells in stem cell-based craniofacial regeneration. PMID:26243590

  12. GMDH-type neural network approach for modeling the discharge coefficient of rectangular sharp-crested side weirs

    Directory of Open Access Journals (Sweden)

    Isa Ebtehaj

    2015-12-01

    Full Text Available Estimating the discharge coefficient using hydraulic and geometrical specifications is one of the influential factors in predicting the discharge passing over a side weir. Taking into account the fact that existing equations are incapable of estimating the discharge coefficient well, artificial intelligence methods are used to predict it. In this study, Group Method of Data Handling (GMDH was used for the purpose of predicting the discharge coefficient in a side weir. The Froude number (F1, weir dimensionless length (b/B, ratios of weir length to depth of upstream flow (b/y1 and weir height to its length (p/y1 were taken as input parameters to express a new model for predicting the discharge coefficient. Two different sets of laboratory data were used to train the artificial network and test the new model. Different statistical indexes were used to evaluate the performance of the GMDH model presented for two states, training and testing. The results indicate that the proposed model predicts the discharge coefficient precisely (MAPE = 5.263 & RMSE = 0.038 and this model is more accurate in predicting than the feed-forward neural network model and existing nonlinear regression equations.

  13. NEURAL AND CARDIAC TOXICITIES ASSOCIATED WITH 3,4-METHYLENEDIOXYMETHAMPHETAMINE (MDMA)

    OpenAIRE

    Baumann, Michael H.; Rothman, Richard B.

    2009-01-01

    (±)-3,4-Methylenedioxymethamphetamine (MDMA) is a commonly abused illicit drug which affects multiple organ systems. In animals, high-dose administration of MDMA produces deficits in serotonin (5-HT) neurons (e.g., depletion of forebrain 5-HT) that have been viewed as neurotoxicity. Recent data implicate MDMA in the development of valvular heart disease (VHD). The present paper reviews several issues related to MDMA-associated neural and cardiac toxicities. The hypothesis of MDMA neurotoxicit...

  14. Musculocontractural Ehlers–Danlos syndrome and neurocristopathies: dermatan sulfate is required for Xenopus neural crest cells to migrate and adhere to fibronectin

    Directory of Open Access Journals (Sweden)

    Nadège Gouignard

    2016-06-01

    Full Text Available Of all live births with congenital anomalies, approximately one-third exhibit deformities of the head and face. Most craniofacial disorders are associated with defects in a migratory stem and progenitor cell population, which is designated the neural crest (NC. Musculocontractural Ehlers–Danlos syndrome (MCEDS is a heritable connective tissue disorder with distinct craniofacial features; this syndrome comprises multiple congenital malformations that are caused by dysfunction of dermatan sulfate (DS biosynthetic enzymes, including DS epimerase-1 (DS-epi1; also known as DSE. Studies in mice have extended our understanding of DS-epi1 in connective tissue maintenance; however, its role in fetal development is not understood. We demonstrate that DS-epi1 is important for the generation of isolated iduronic acid residues in chondroitin sulfate (CS/DS proteoglycans in early Xenopus embryos. The knockdown of DS-epi1 does not affect the formation of early NC progenitors; however, it impairs the correct activation of transcription factors involved in the epithelial–mesenchymal transition (EMT and reduces the extent of NC cell migration, which leads to a decrease in NC-derived craniofacial skeleton, melanocytes and dorsal fin structures. Transplantation experiments demonstrate a tissue-autonomous role for DS-epi1 in cranial NC cell migration in vivo. Cranial NC explant and single-cell cultures indicate a requirement of DS-epi1 in cell adhesion, spreading and extension of polarized cell processes on fibronectin. Thus, our work indicates a functional link between DS and NC cell migration. We conclude that NC defects in the EMT and cell migration might account for the craniofacial anomalies and other congenital malformations in MCEDS, which might facilitate the diagnosis and development of therapies for this distressing condition. Moreover, the presented correlations between human DS-epi1 expression and gene sets of mesenchymal character, invasion and

  15. Control of the collective migration of enteric neural crest cells by the Complement anaphylatoxin C3a and N-cadherin.

    Science.gov (United States)

    Broders-Bondon, Florence; Paul-Gilloteaux, Perrine; Gazquez, Elodie; Heysch, Julie; Piel, Matthieu; Mayor, Roberto; Lambris, John D; Dufour, Sylvie

    2016-06-01

    We analyzed the cellular and molecular mechanisms governing the adhesive and migratory behavior of enteric neural crest cells (ENCCs) during their collective migration within the developing mouse gut. We aimed to decipher the role of the complement anaphylatoxin C3a during this process, because this well-known immune system attractant has been implicated in cephalic NCC co-attraction, a process controlling directional migration. We used the conditional Ht-PA-cre transgenic mouse model allowing a specific ablation of the N-cadherin gene and the expression of a fluorescent reporter in migratory ENCCs without affecting the central nervous system. We performed time-lapse videomicroscopy of ENCCs from control and N-cadherin mutant gut explants cultured on fibronectin (FN) and micropatterned FN-stripes with C3a or C3aR antagonist, and studied cell migration behavior with the use of triangulation analysis to quantify cell dispersion. We performed ex vivo gut cultures with or without C3aR antagonist to determine the effect on ENCC behavior. Confocal microscopy was used to analyze the cell-matrix adhesion properties. We provide the first demonstration of the localization of the complement anaphylatoxin C3a and its receptor on ENCCs during their migration in the embryonic gut. C3aR receptor inhibition alters ENCC adhesion and migration, perturbing directionality and increasing cell dispersion both in vitro and ex vivo. N-cadherin-null ENCCs do not respond to C3a co-attraction. These findings indicate that C3a regulates cell migration in a N-cadherin-dependent process. Our results shed light on the role of C3a in regulating collective and directional cell migration, and in ganglia network organization during enteric nervous system ontogenesis. The detection of an immune system chemokine in ENCCs during ENS development may also shed light on new mechanisms for gastrointestinal disorders. PMID:27041467

  16. Derivation of mesenchymal stromal cells from pluripotent stem cells through a neural crest lineage using small molecule compounds with defined media.

    Directory of Open Access Journals (Sweden)

    Makoto Fukuta

    Full Text Available Neural crest cells (NCCs are an embryonic migratory cell population with the ability to differentiate into a wide variety of cell types that contribute to the craniofacial skeleton, cornea, peripheral nervous system, and skin pigmentation. This ability suggests the promising role of NCCs as a source for cell-based therapy. Although several methods have been used to induce human NCCs (hNCCs from human pluripotent stem cells (hPSCs, such as embryonic stem cells (ESCs and induced pluripotent stem cells (iPSCs, further modifications are required to improve the robustness, efficacy, and simplicity of these methods. Chemically defined medium (CDM was used as the basal medium in the induction and maintenance steps. By optimizing the culture conditions, the combination of the GSK3β inhibitor and TGFβ inhibitor with a minimum growth factor (insulin very efficiently induced hNCCs (70-80% from hPSCs. The induced hNCCs expressed cranial NCC-related genes and stably proliferated in CDM supplemented with EGF and FGF2 up to at least 10 passages without changes being observed in the major gene expression profiles. Differentiation properties were confirmed for peripheral neurons, glia, melanocytes, and corneal endothelial cells. In addition, cells with differentiation characteristics similar to multipotent mesenchymal stromal cells (MSCs were induced from hNCCs using CDM specific for human MSCs. Our simple and robust induction protocol using small molecule compounds with defined media enabled the generation of hNCCs as an intermediate material producing terminally differentiated cells for cell-based innovative medicine.

  17. Transient Global Amnesia following Neural and Cardiac Angiography May Be Related to Ischemia

    Directory of Open Access Journals (Sweden)

    Hongzhou Duan

    2016-01-01

    Full Text Available Introduction. Transient global amnesia (TGA following angiography is rare, and the pathogenesis has not been illustrated clearly till now. The aim of this research is to explore the pathogenesis of TGA following angiography by analyzing our data and reviewing the literature. Methods. We retrospectively studied 20836 cases with angiography in our hospital between 2007 and 2015 and found 9 cases with TGA following angiography. The data of these 9 cases were analyzed. Results. We found all 9 cases with TGA following neural angiography (5 in 4360 or cardiac angiography (4 in 8817 and no case with TGA following peripheral angiography (0 in 7659. Statistical difference was found when comparing the neural and cardiac angiography group with peripheral group (p=0.022. Two cases with TGA were confirmed with small acute infarctions in hippocampus after angiography. This might be related to the microemboli which were rushed into vertebral artery following blood flow during neural angiography or cardiac angiography. There was no statistical difference when comparing the different approaches for angiography (p=0.82 and different contrast agents (p=0.619. Conclusion. Based on the positive findings of imaging study and our analysis, we speculate that ischemia in the medial temporal lobe with the involvement of the hippocampus might be an important reason of TGA following angiography.

  18. Automated Cardiac Beat Classification Using RBF Neural Networks

    Directory of Open Access Journals (Sweden)

    Ali Khazaee

    2013-04-01

    Full Text Available This paper proposes a four stage, denoising, feature extraction, optimization and classification method for detection of premature ventricular contractions. In the first stage, we investigate the application of wavelet denoising in noise reduction of multi-channel high resolution ECG signals. In this stage, the Stationary Wavelet Transform is used. Feature extraction module extracts ten ECG morphological features and one timing interval feature. Then a number of radial basis function (RBF neural networks with different value of spread parameter are designed and compared their ability for classification of three different classes of ECG signals. Genetic Algorithm is used to find best value of RBF parameters. A classification accuracy of 100% for training dataset and 95.66% for testing dataset and an overall accuracy of detection of 95.83% were achieved over seven files from the MIT/BIH arrhythmia database.

  19. Wild-type ALK and activating ALK-R1275Q and ALK-F1174L mutations upregulate Myc and initiate tumor formation in murine neural crest progenitor cells

    Science.gov (United States)

    Montavon, Gisèle; Jauquier, Nicolas; Coulon, Aurélie; Peuchmaur, Michel; Flahaut, Marjorie; Bourloud, Katia Balmas; Yan, Pu; Delattre, Olivier; Sommer, Lukas; Joseph, Jean-Marc; Janoueix-Lerosey, Isabelle; Gross, Nicole; Mühlethaler-Mottet, Annick

    2014-01-01

    The anaplastic lymphoma kinase (ALK) gene is overexpressed, mutated or amplified in most neuroblastoma (NB), a pediatric neural crest-derived embryonal tumor. The two most frequent mutations, ALK-F1174L and ALK-R1275Q, contribute to NB tumorigenesis in mouse models, and cooperate with MYCN in the oncogenic process. However, the precise role of activating ALK mutations or ALK-wt overexpression in NB tumor initiation needs further clarification. Human ALK-wt, ALK-F1174L, or ALK-R1275Q were stably expressed in murine neural crest progenitor cells (NCPC), MONC-1 or JoMa1, immortalized with v-Myc or Tamoxifen-inducible Myc-ERT, respectively. While orthotopic implantations of MONC-1 parental cells in nude mice generated various tumor types, such as NB, osteo/chondrosarcoma, and undifferentiated tumors, due to v-Myc oncogenic activity, MONC-1-ALK-F1174L cells only produced undifferentiated tumors. Furthermore, our data represent the first demonstration of ALK-wt transforming capacity, as ALK-wt expression in JoMa1 cells, likewise ALK-F1174L, or ALK-R1275Q, in absence of exogenous Myc-ERT activity, was sufficient to induce the formation of aggressive and undifferentiated neural crest cell-derived tumors, but not to drive NB development. Interestingly, JoMa1-ALK tumors and their derived cell lines upregulated Myc endogenous expression, resulting from ALK activation, and both ALK and Myc activities were necessary to confer tumorigenic properties on tumor-derived JoMa1 cells in vitro. PMID:24947326

  20. Detection and classification of cardiac ischemia using vectorcardiogram signal via neural network

    Directory of Open Access Journals (Sweden)

    Ali Reza Mehri Dehnavi

    2011-01-01

    Full Text Available Background: Various techniques are used in diagnosing cardiac diseases. The electrocardiogram is one of these tools in common use. In this study vectorcardiogram (VCG signals are used as a tool for detection of cardiac ischemia. Methods: VCG signals used in this study were obtained form 60 patients suspected to have ischemia disease and 10 normal candidates. Verification of the ischemia had done by the cardiologist during strain test by the evaluation of electrocardiogram (ECG records and patient′s clinical history. The recorder device was Cardiax digital recorder system. The VCG signals were recorded in Frank lead configuration system. Results: Extracted ischemia VCG signals have been configured with 22 features. Feature dimensionalities were reduced by the use of Independent Components Analysis and Principal Component Analysis tools. Results obtained from strain test indicated that among 60 subjects, 50 had negative results and 10 had positive results. Ischemia detection of neural network using VCG parameters indicates 86% accuracy. Classification result on neural network using ECG ischemia detection parameters is 73% accurate. Accumulative evaluation including VCG analysis and strain test indicates 90% consistency. Conclusions: Regarding the obtained results in this study, VCG has higher accuracy than ECG, so that in cases which ECG signal cannot provide certain diagnosis of existence or non-existence of ischemia, VCG signal can help in a wider range. We suggest the use of VCG as an auxiliary low cost tool in ischemia detection.

  1. Optogenetic stimulation of multiwell MEA plates for neural and cardiac applications

    Science.gov (United States)

    Clements, Isaac P.; Millard, Daniel C.; Nicolini, Anthony M.; Preyer, Amanda J.; Grier, Robert; Heckerling, Andrew; Blum, Richard A.; Tyler, Phillip; McSweeney, K. M.; Lu, Yi-Fan; Hall, Diana; Ross, James D.

    2016-03-01

    Microelectrode array (MEA) technology enables advanced drug screening and "disease-in-a-dish" modeling by measuring the electrical activity of cultured networks of neural or cardiac cells. Recent developments in human stem cell technologies, advancements in genetic models, and regulatory initiatives for drug screening have increased the demand for MEA-based assays. In response, Axion Biosystems previously developed a multiwell MEA platform, providing up to 96 MEA culture wells arrayed into a standard microplate format. Multiwell MEA-based assays would be further enhanced by optogenetic stimulation, which enables selective excitation and inhibition of targeted cell types. This capability for selective control over cell culture states would allow finer pacing and probing of cell networks for more reliable and complete characterization of complex network dynamics. Here we describe a system for independent optogenetic stimulation of each well of a 48-well MEA plate. The system enables finely graded control of light delivery during simultaneous recording of network activity in each well. Using human induced pluripotent stem cell (hiPSC) derived cardiomyocytes and rodent primary neuronal cultures, we demonstrate high channel-count light-based excitation and suppression in several proof-of-concept experimental models. Our findings demonstrate advantages of combining multiwell optical stimulation and MEA recording for applications including cardiac safety screening, neural toxicity assessment, and advanced characterization of complex neuronal diseases.

  2. Retinol dehydrogenase, RDH1l, is essential for the heart development and cardiac performance in zebrafish

    Institute of Scientific and Technical Information of China (English)

    WANG Wei; ZHANG Li-feng; GUI Yong-hao; SONG Hou-yan

    2013-01-01

    Background Retinoic acid (RA) is a potent signaling molecule that plays pleiotropic roles in patterning,morphogenesis,and organogenesis during embryonic development.The synthesis from retinol (vitamin A) to retinoic acid requires two sequential oxidative steps.The first step involves the oxidation of retinol to retinal through the action of retinol dehydrogenases.Retinol dehydrogenases1l (RDH1l) is a novel zebrafish retinol dehydrogenase.Herein we investigated the role of zebrafish RDH1l in heart development and cardiac performance in detail.Methods RDH1l specific morpholino was used to reduce the function of RDH1l in zebrafish.The gene expressions were observed by using whole mount in situ hybridization.Heart rates were observed and recorded under the microscope from 24 to 72 hours post fertilization (hpf).The cardiac performance was analyzed by measuring ventricular shortening fraction (VSF).Results The knock-down of RDH1l led to abnormal neural crest cells migration and reduced numbers of neural crest cells in RDH1l morphant embryos.The reduced numbers of cardiac neural crest cells also can be seen in RDH1l morphant embryos.Furthermore,the morpholino-mediated knock-down of RDH1l resulted in the abnormal heart loop.The left-right determining genes expression pattern was altered in RDH1l morphant embryos.The impaired cardiac performance was observed in RDH1l morphant embryos.Taken together,these data demonstrate that RDH1l is essential for the heart development and cardiac performance in zebrafish.Conclusions RDH1l plays a important role in the neural crest cells development,and then ultimately affects the heart loop and cardiac performance.These results show for the first time that an enzyme involved in the retinol to retinaldehyde conversion participate in the heart development and cardiac performance in zebrafish.

  3. The influence of different SPECT reconstruction algorithms on cardiac ischemia with the use artificial neural networks

    International Nuclear Information System (INIS)

    The aim of the study was the attempt to evaluate the influence of two different methods of cardiac perfusion SPECT reconstruction (FBP and ITW) on clinical efficacy in diagnosing the coronary artery disease as well as the cardiac ischemia detection in three areas of heart vascularized by main coronary arteries: LAD, LCX and RCA with the use of artificial neural networks (ANN). The study was performed retrospectively with the use of the diagnostic image records as well as clinical dataset of 43 patients. Myocardial perfusion stress/rest SPECT study and X-ray coronarography data were evaluated for each patient. The results of coronary angiography were considered the reference method. The cardiac SPECT data were reconstructed using the two different methods: filtered backprojection (FBP) and iterative Wallis method (ITW). The local perfusion deficits denominated in stress and rest study in three main vessel cardiac segments were the main input values for the ANN. The sensitivity of detection of coronary artery disease with the of ANN was 95% for both FBP and ITW reconstruction technique (p≥0.05). The sensitivity analysis of regional ischemia detection by ANN in areas LAD, LCX and RCA provided 97%, 65% and 64%, correspondingly for FDP method. With the use of ITW algorithm the sensitivity in the respective regions was: 65%, 55% and 60%. The difference in sensitivity of ANN ischemia detection for the LAD region was statistically significant for FDP versus ITW reconstruction algorithm (p=0.0007). No statistical discrepancy in sensitivity was stated in the other regions due to reconstruction technique (p≥0.005). The compared method of reconstruction of myocardial perfusion SPECT studies the do not influence the clinical efficacy in diagnosing the coronary disease with the use of ANN. In case of ANN application for local ischemia recognition results of the study indicate the FBP algorithm effective. (author)

  4. Effect of Tbxl knock-down on cardiac performance in zebrafish

    Institute of Scientific and Technical Information of China (English)

    ZHANG Li-feng; GUI Yong-hao; WANG Yue-xiang; JIANG Qiu; SONG Hou-yan

    2010-01-01

    Background Tbxl is the major candidate gene for DiGeorge syndrome (DGS). Similar to defects observed in DGS patients, the structures disrupted in Tbxl-/- animal models are derived from the neural crest cells during development. Although the morphological phenotypes of some Tbxl knock-down animal models have been well described, analysis of the cardiac performance is limited. Therefore, myocardial performance was explored in Tbxl morpholino injected zebrafish embryos. Methods To elucidate these issues, Tbxl specific morpholino was used to reduce the function of Tbxl in zebrafish. The differentiation of the myocardial cells was observed using whole mount in situ hybridization. Heart rates were observed and recorded under the microscope from 24 to 72 hours post fertilization (hpf). The cardiac performance was analyzed by measuring ventricular shortening fraction and atrial shortening fraction.Results Tbxl morpholino injected embryos were characterized by defects in the pharyngeal arches, otic vesicle, aortic arches and thymus. In addition, Tbxl knock down reduced the amount of pharyngeal neural crest cells in zebrafish. Abnormal cardiac morphology was visible in nearly 20% of the Tbxl morpholino injected embryos. The hearts in these embryos did not loop or loop incompletely. Importantly, cardiac performance and heart rate were reduced in Tbxl morpholino injected embryos.Conclusions Tbxl might play an essential role in the development of pharyngeal neural crest cells in zebrafish. Cardiac performance is impaired by Tbxl knock down in zebrafish.

  5. A cardiac electrical activity model based on a cellular automata system in comparison with neural network model.

    Science.gov (United States)

    Khan, Muhammad Sadiq Ali; Yousuf, Sidrah

    2016-03-01

    Cardiac Electrical Activity is commonly distributed into three dimensions of Cardiac Tissue (Myocardium) and evolves with duration of time. The indicator of heart diseases can occur randomly at any time of a day. Heart rate, conduction and each electrical activity during cardiac cycle should be monitor non-invasively for the assessment of "Action Potential" (regular) and "Arrhythmia" (irregular) rhythms. Many heart diseases can easily be examined through Automata model like Cellular Automata concepts. This paper deals with the different states of cardiac rhythms using cellular automata with the comparison of neural network also provides fast and highly effective stimulation for the contraction of cardiac muscles on the Atria in the result of genesis of electrical spark or wave. The specific formulated model named as "States of automaton Proposed Model for CEA (Cardiac Electrical Activity)" by using Cellular Automata Methodology is commonly shows the three states of cardiac tissues conduction phenomena (i) Resting (Relax and Excitable state), (ii) ARP (Excited but Absolutely refractory Phase i.e. Excited but not able to excite neighboring cells) (iii) RRP (Excited but Relatively Refractory Phase i.e. Excited and able to excite neighboring cells). The result indicates most efficient modeling with few burden of computation and it is Action Potential during the pumping of blood in cardiac cycle. PMID:27087101

  6. Using Mixture Structures of Neural Networks in Order to Detect Cardiac Arrhythmias Using Fusion of Temporal and Wavelet Features

    Directory of Open Access Journals (Sweden)

    syed mohammd Razavi

    2011-05-01

    Full Text Available In recent years the use of intelligent systems in science and engineering, especially in the diagnosis of disease, is increasingly growing. In this paper a smart way to diagnose heart disease (cardiac arrhythmias is presented. This method is based on a combination of structures using neural networks for classification of normal operation and four abnormal heart functions. In the combination of these structures, some neural networks as a mediator, and some of them have been used as a specialist. In the proposed method firstly for removing noise from ECG signal, preprocessing was performed. The various time features (including fifteen properties and wavelet features (includes fifteen feature are extracted from the noise free signal and given the large number of selected features, principal components analysis is used for feature reduction to eight features. The proposed structures of MLP neural networks and RBF neural networks are appropriately trained for classification of arrhythmias and their performance has been evaluated. The results of the implementation of the proposed method on MIT / BIH database show the better performance in the diagnosis of cardiac arrhythmias compared to previous approaches.

  7. Creative Copper Crests

    Science.gov (United States)

    Knab, Thomas

    2011-01-01

    In this article, the author discusses how to create an art activity that would link the computer-created business cards of fourth-grade students with an upcoming school-wide medieval event. Creating family crests from copper foil would be a great connection, since they, like business cards, are an individual's way to identify themselves to others.…

  8. Chronic vagal stimulation for the treatment of low ejection fraction heart failure : results of the NEural Cardiac TherApy foR Heart Failure (NECTAR-HF) randomized controlled trial

    NARCIS (Netherlands)

    Zannad, Faiez; De Ferrari, Gaetano M; Tuinenburg, Anton E; Wright, David; Brugada, Josep; Butter, Christian; Klein, Helmut; Stolen, Craig; Meyer, Scott; Stein, Kenneth M; Ramuzat, Agnes; Schubert, Bernd; Daum, Doug; Neuzil, Petr; Botman, Cornelis; Castel, Maria Angeles; D'Onofrio, Antonio; Solomon, Scott D; Wold, Nicholas; Ruble, Stephen B

    2015-01-01

    AIM: The neural cardiac therapy for heart failure (NECTAR-HF) was a randomized sham-controlled trial designed to evaluate whether a single dose of vagal nerve stimulation (VNS) would attenuate cardiac remodelling, improve cardiac function and increase exercise capacity in symptomatic heart failure p

  9. Detection and classification of cardiac ischemia using vectorcardiogram signal via neural network

    OpenAIRE

    Ali Reza Mehri Dehnavi; Iman Farahabadi; Hossain Rabbani; Amin Farahabadi; Mohamad Parsa Mahjoob; Nasser Rajabi Dehnavi

    2011-01-01

    Background: Various techniques are used in diagnosing cardiac diseases. The electrocardiogram is one of these tools in common use. In this study vectorcardiogram (VCG) signals are used as a tool for detection of cardiac ischemia. Methods: VCG signals used in this study were obtained form 60 patients suspected to have ischemia disease and 10 normal candidates. Verification of the ischemia had done by the cardiologist during strain test by the evaluation of electrocardiogram (ECG) records ...

  10. Cardiac Arrhythmias Classification Method Based on MUSIC, Morphological Descriptors, and Neural Network

    Science.gov (United States)

    Naghsh-Nilchi, Ahmad R.; Kadkhodamohammadi, A. Rahim

    2009-12-01

    An electrocardiogram (ECG) beat classification scheme based on multiple signal classification (MUSIC) algorithm, morphological descriptors, and neural networks is proposed for discriminating nine ECG beat types. These are normal, fusion of ventricular and normal, fusion of paced and normal, left bundle branch block, right bundle branch block, premature ventricular concentration, atrial premature contraction, paced beat, and ventricular flutter. ECG signal samples from MIT-BIH arrhythmia database are used to evaluate the scheme. MUSIC algorithm is used to calculate pseudospectrum of ECG signals. The low-frequency samples are picked to have the most valuable heartbeat information. These samples along with two morphological descriptors, which deliver the characteristics and features of all parts of the heart, form an input feature vector. This vector is used for the initial training of a classifier neural network. The neural network is designed to have nine sample outputs which constitute the nine beat types. Two neural network schemes, namely multilayered perceptron (MLP) neural network and a probabilistic neural network (PNN), are employed. The experimental results achieved a promising accuracy of 99.03% for classifying the beat types using MLP neural network. In addition, our scheme recognizes NORMAL class with 100% accuracy and never misclassifies any other classes as NORMAL.

  11. Cardiac Arrhythmias Classification Method Based on MUSIC, Morphological Descriptors, and Neural Network

    Directory of Open Access Journals (Sweden)

    2009-03-01

    Full Text Available An electrocardiogram (ECG beat classification scheme based on multiple signal classification (MUSIC algorithm, morphological descriptors, and neural networks is proposed for discriminating nine ECG beat types. These are normal, fusion of ventricular and normal, fusion of paced and normal, left bundle branch block, right bundle branch block, premature ventricular concentration, atrial premature contraction, paced beat, and ventricular flutter. ECG signal samples from MIT-BIH arrhythmia database are used to evaluate the scheme. MUSIC algorithm is used to calculate pseudospectrum of ECG signals. The low-frequency samples are picked to have the most valuable heartbeat information. These samples along with two morphological descriptors, which deliver the characteristics and features of all parts of the heart, form an input feature vector. This vector is used for the initial training of a classifier neural network. The neural network is designed to have nine sample outputs which constitute the nine beat types. Two neural network schemes, namely multilayered perceptron (MLP neural network and a probabilistic neural network (PNN, are employed. The experimental results achieved a promising accuracy of 99.03% for classifying the beat types using MLP neural network. In addition, our scheme recognizes NORMAL class with 100% accuracy and never misclassifies any other classes as NORMAL.

  12. An Unusual Cause of Cardiac Arrhythmias; Mediastinal Schwannoma

    Directory of Open Access Journals (Sweden)

    Serdar Ozkan

    2014-02-01

    Full Text Available Schwannomas are rare tumours, which originated from neural crest cells. Thoracic schwannomas are very rare and most commonly seen in posterior mediastinum. In a 39 year old female patient whose tumor story dated back to 4 years, a 14 cm extra parenchymal intrathoracic tumor was observed to put minimal pressure on the heart. The patient%u2019s arrhythmia, who had preoperative complaints of palpitations, was improved after tumor excision. Although schwannomas generally are asympthomatic masses, they can lead mass effect according to their localization. In this study, patient with thoracic schwannoma presented with cardiac arrhythmia which never reported in literature so far.

  13. Co-culture of neural crest stem cells (NCSC and insulin producing beta-TC6 cells results in cadherin junctions and protection against cytokine-induced beta-cell death.

    Directory of Open Access Journals (Sweden)

    Anongnad Ngamjariyawat

    Full Text Available PURPOSE: Transplantation of pancreatic islets to Type 1 diabetes patients is hampered by inflammatory reactions at the transplantation site leading to dysfunction and death of insulin producing beta-cells. Recently we have shown that co-transplantation of neural crest stem cells (NCSCs together with the islet cells improves transplantation outcome. The aim of the present investigation was to describe in vitro interactions between NCSCs and insulin producing beta-TC6 cells that may mediate protection against cytokine-induced beta-cell death. PROCEDURES: Beta-TC6 and NCSC cells were cultured either alone or together, and either with or without cell culture inserts. The cultures were then exposed to the pro-inflammatory cytokines IL-1β and IFN-γ for 48 hours followed by analysis of cell death rates (flow cytometry, nitrite production (Griess reagent, protein localization (immunofluorescence and protein phosphorylation (flow cytometry. RESULTS: We observed that beta-TC6 cells co-cultured with NCSCs were protected against cytokine-induced cell death, but not when separated by cell culture inserts. This occurred in parallel with (i augmented production of nitrite from beta-TC6 cells, indicating that increased cell survival allows a sustained production of nitric oxide; (ii NCSC-derived laminin production; (iii decreased phospho-FAK staining in beta-TC6 cell focal adhesions, and (iv decreased beta-TC6 cell phosphorylation of ERK(T202/Y204, FAK(Y397 and FAK(Y576. Furthermore, co-culture also resulted in cadherin and beta-catenin accumulations at the NCSC/beta-TC6 cell junctions. Finally, the gap junction inhibitor carbenoxolone did not affect cytokine-induced beta-cell death during co-culture with NCSCs. CONCLUSION: In summary, direct contacts, but not soluble factors, promote improved beta-TC6 viability when co-cultured with NCSCs. We hypothesize that cadherin junctions between NCSC and beta-TC6 cells promote powerful signals that maintain beta

  14. Recurrent Fully Convolutional Neural Networks for Multi-slice MRI Cardiac Segmentation

    OpenAIRE

    Poudel, Rudra P K; Lamata, Pablo; Montana, Giovanni

    2016-01-01

    In cardiac magnetic resonance imaging, fully-automatic segmentation of the heart enables precise structural and functional measurements to be taken, e.g. from short-axis MR images of the left-ventricle. In this work we propose a recurrent fully-convolutional network (RFCN) that learns image representations from the full stack of 2D slices and has the ability to leverage inter-slice spatial dependences through internal memory units. RFCN combines anatomical detection and segmentation into a si...

  15. Percutaneous autonomic neural modulation: A novel technique to treat cardiac arrhythmia

    International Nuclear Information System (INIS)

    Ablation and anti-arrhythmic medications have shown promise but have been met with varying success and unwanted side effects such as myocardial injury, arrhythmias, and morbidity from invasive surgical intervention. The answer to improving efficacy of ablation may include modulation of the cardiac aspect of the autonomic nervous system. Our lab has developed a novel approach and device to navigate the oblique sinus and to use DC current and saline/alcohol irrigation to selectively stimulate and block the autonomic ganglia found on the epicardial side of the heart. This novel approach minimizes myocardial damage from thermal injury and provides a less invasive and targeted approach. For feasibility, proof-of-concept, and safety monitoring, we carried out canine studies to test this novel application. Our results suggest a safer and less invasive way of modulating arrhythmogenic substrate that may lead to improved treatment of AF in humans

  16. Percutaneous autonomic neural modulation: A novel technique to treat cardiac arrhythmia

    Energy Technology Data Exchange (ETDEWEB)

    DeSimone, Christopher V.; Madhavan, Malini [Cardiovascular Diseases, Department of Medicine, Mayo Clinic, Rochester, MN (United States); Venkatachalam, Kalpathi L. [Cardiovascular Diseases, Department of Medicine, Mayo Clinic, Jacksonville, FL (United States); Knudson, Mark B. [Mayo Clinic, Rochester, MN (United States); EnteroMedics, EnteroMedics, St. Paul, MN (United States); Asirvatham, Samuel J., E-mail: asirvatham.samuel@mayo.edu [Cardiovascular Diseases, Department of Medicine, Mayo Clinic, Rochester, MN (United States); Pediatric Cardiology, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester, MN (United States)

    2013-05-15

    Ablation and anti-arrhythmic medications have shown promise but have been met with varying success and unwanted side effects such as myocardial injury, arrhythmias, and morbidity from invasive surgical intervention. The answer to improving efficacy of ablation may include modulation of the cardiac aspect of the autonomic nervous system. Our lab has developed a novel approach and device to navigate the oblique sinus and to use DC current and saline/alcohol irrigation to selectively stimulate and block the autonomic ganglia found on the epicardial side of the heart. This novel approach minimizes myocardial damage from thermal injury and provides a less invasive and targeted approach. For feasibility, proof-of-concept, and safety monitoring, we carried out canine studies to test this novel application. Our results suggest a safer and less invasive way of modulating arrhythmogenic substrate that may lead to improved treatment of AF in humans.

  17. Chronic vagal stimulation for the treatment of low ejection fraction heart failure: results of the NEural Cardiac TherApy foR Heart Failure (NECTAR-HF) randomized controlled trial

    OpenAIRE

    Zannad, Faiez; De Ferrari, Gaetano M.; Tuinenburg, Anton E.; Wright, David; Brugada, Josep; Butter, Christian; Klein, Helmut; Stolen, Craig; Meyer, Scott; Stein, Kenneth M.; Ramuzat, Agnes; Schubert, Bernd; Daum, Doug; Neuzil, Petr; Botman, Cornelis

    2014-01-01

    Aim The neural cardiac therapy for heart failure (NECTAR-HF) was a randomized sham-controlled trial designed to evaluate whether a single dose of vagal nerve stimulation (VNS) would attenuate cardiac remodelling, improve cardiac function and increase exercise capacity in symptomatic heart failure patients with severe left ventricular (LV) systolic dysfunction despite guideline recommended medical therapy. Methods: Patients were randomized in a 2 : 1 ratio to receive therapy (VNS ON) or contro...

  18. MicroRNA-21 can promote the differentiation of neural crest stem cells from human follicle into Schwann cells%miR-21促进毛囊神经嵴干细胞分化为许旺细胞

    Institute of Scientific and Technical Information of China (English)

    王艳华; 刘浩; 辛红; 白晓雪; 刘学娟; 倪宇昕

    2014-01-01

    BACKGROUND:MicroRNAs are a class of non-coding single-stranded smal RNA molecules containing 18–25 nucleotides that can bind to the 3’UTR of the mRNA molecules and regulate the protein expression of target genes. Studies have shown that microRNAs could regulate Schwann cel differentiation, myelination maturation and growth of the peripheral nerve. OBJECTIVE: To observe the expression of miR-21 during the differentiation of neural crest stem cels from human folicle into Schwann cels. METHODS: Hair folicle stem cels were cultured and neural crest stem cels were separated from human hair folicles by flow cytometry. Then, the neural crest stem cels were induced to differentiate into Schwann cels. qRT-PCR was used to detect the expression of miR-21 in the process of induction. Neural crest stem cels from hair folicles were divided into control group, agomir-21 group, agomir-NC group, antagomir-21 group and antagomir-NC group. The control group was without intervention. Agomir-21 group was transfected with miR-21 agonist, whereas Antagomir-21 group was transfected with miR-21 antagonist. agomir-NC group and antagomir-NC group were respectively negative controls of agomir-21 group and antagomir-21 group. Finaly, the possible target of miR-21 was searched in database. RESULTS AND CONCLUSION: Neural crest stem cels were successfuly separated from human hair folicles using flow cytometry and induced to differentiate into Schwann cels. In the process of cel differentiation, miR-21 expression was upregulated gradualy. Transfection of miR-21 agonist could enhance the stem cel differentiation into Schwann cels, whereas transfection of miR-21 antagonist could weaken the differentiation capacity of stem cels. Furthermore, we found via database searching that SOX2 maybe a target of miR-21 and participate in the regulatory role of miR-21. This study suggested that hair folicle neural crest stem cels can be used as an important source of Schwann cels and miR-21 can promote the

  19. Crested Ibis%朱鹮

    Institute of Scientific and Technical Information of China (English)

    丁长青

    2010-01-01

    @@ The Crested Ibis(Nipponia nippon,Plates Ⅰ and Ⅱ)(Ciconiiformes: Threskiomithidae)is a mediumsized wading bird,ranging in length from 57.5 to 84.0 cm,with a longish neck and legs,a red featherless face with a crested white head.Its most distinctive morphological character is the long,slender and decurved bill,perfectly adapted for probing in water and mud,or even in cracks on dry ground.The nonbreeding adult is white,with orange cinnamon tones in the tail and flight-feathers.The long bill is black with a red tip.Its red legs do not extend beyond the tail in flight(Hoyo et al.,1992).

  20. Lineage and morphogenetic analysis of the cardiac valves.

    Science.gov (United States)

    de Lange, Frederik J; Moorman, Antoon F M; Anderson, Robert H; Männer, Jörg; Soufan, Alexandre T; de Gier-de Vries, Corrie; Schneider, Michael D; Webb, Sandra; van den Hoff, Maurice J B; Christoffels, Vincent M

    2004-09-17

    We used a genetic lineage-labeling system to establish the material contributions of the progeny of 3 specific cell types to the cardiac valves. Thus, we labeled irreversibly the myocardial (alphaMHC-Cre+), endocardial (Tie2-Cre+), and neural crest (Wnt1-Cre+) cells during development and assessed their eventual contribution to the definitive valvar complexes. The leaflets and tendinous cords of the mitral and tricuspid valves, the atrioventricular fibrous continuity, and the leaflets of the outflow tract valves were all found to be generated from mesenchyme derived from the endocardium, with no substantial contribution from cells of the myocardial and neural crest lineages. Analysis of chicken-quail chimeras revealed absence of any substantial contribution from proepicardially derived cells. Molecular and morphogenetic analysis revealed several new aspects of atrioventricular valvar formation. Marked similarities are seen during the formation of the mural leaflets of the mitral and tricuspid valves. These leaflets form by protrusion and growth of a sheet of atrioventricular myocardium into the ventricular lumen, with subsequent formation of valvar mesenchyme on its surface rather than by delamination of lateral cushions from the ventricular myocardial wall. The myocardial layer is subsequently removed by the process of apoptosis. In contrast, the aortic leaflet of the mitral valve, the septal leaflet of the tricuspid valve, and the atrioventricular fibrous continuity between these valves develop from the mesenchyme of the inferior and superior atrioventricular cushions. The tricuspid septal leaflet then delaminates from the muscular ventricular septum late in development. PMID:15297379

  1. Classification of Atrial Septal Defect and Ventricular Septal Defect with Documented Hemodynamic Parameters via Cardiac Catheterization by Genetic Algorithms and Multi-Layered Artificial Neural Network

    Directory of Open Access Journals (Sweden)

    Mustafa Yıldız

    2012-08-01

    Full Text Available Introduction: We aimed to develop a classification method to discriminate ventricular septal defect and atrial septal defect by using severalhemodynamic parameters.Patients and Methods: Forty three patients (30 atrial septal defect, 13 ventricular septal defect; 26 female, 17 male with documentedhemodynamic parameters via cardiac catheterization are included to study. Such parameters as blood pressure values of different areas,gender, age and Qp/Qs ratios are used for classification. Parameters, we used in classification are determined by divergence analysismethod. Those parameters are; i pulmonary artery diastolic pressure, ii Qp/Qs ratio, iii right atrium pressure, iv age, v pulmonary arterysystolic pressure, vi left ventricular sistolic pressure, vii aorta mean pressure, viii left ventricular diastolic pressure, ix aorta diastolicpressure, x aorta systolic pressure. Those parameters detected from our study population, are uploaded to multi-layered artificial neuralnetwork and the network was trained by genetic algorithm.Results: Trained cluster consists of 14 factors (7 atrial septal defect and 7 ventricular septal defect. Overall success ratio is 79.2%, andwith a proper instruction of artificial neural network this ratio increases up to 89%.Conclusion: Parameters, belonging to artificial neural network, which are needed to be detected by the investigator in classical methods,can easily be detected with the help of genetic algorithms. During the instruction of artificial neural network by genetic algorithms, boththe topology of network and factors of network can be determined. During the test stage, elements, not included in instruction cluster, areassumed as in test cluster, and as a result of this study, we observed that multi-layered artificial neural network can be instructed properly,and neural network is a successful method for aimed classification.

  2. Design Guidelines for Low Crested Structures

    DEFF Research Database (Denmark)

    Burcharth, H. F.; Lamberti, Alberto

    2004-01-01

    The paper presents an overview of the design guidelines for low crested structures (LCS's) to be applied in coastal protection schemes. The design guidelines are formulated as a part of the research project: Environmental Design of Low Crested Coastal Defence Structures (DELOS) within the EC 5FP...

  3. Whistler wave trapping in a density crest

    International Nuclear Information System (INIS)

    The linear trapping process of whistler waves in a field-aligned density crest is investigated theoretically and experimentally below ω = ωsub(c)/2 (half gyrofrequency). The conditions of the crest trapping are derived in terms of the frequency ω/ωsub(c), the incident wave-normal angle theta sub(i), and the density ratio n sub(i)/n sub(o), where n sub(i) and n sub(o) denote the density at the incident point and that at the ridge, respectively. The oscillation length of the trapped ray path is calculated for a parabolic density profile. The experiment on antenna-excited whistler wave has been performed in a large magnetized plasma with the density crest. The phase and amplitude profile of the whistler wave is measured along and across the crest. The measurement has verified characteristic behaviors of the crest trapping. (author)

  4. Human fetal cardiac progenitors: The role of stem cells and progenitors in the fetal and adult heart.

    Science.gov (United States)

    Bulatovic, Ivana; Månsson-Broberg, Agneta; Sylvén, Christer; Grinnemo, Karl-Henrik

    2016-02-01

    The human fetal heart is formed early during embryogenesis as a result of cell migrations, differentiation, and formative blood flow. It begins to beat around gestation day 22. Progenitor cells are derived from mesoderm (endocardium and myocardium), proepicardium (epicardium and coronary vessels), and neural crest (heart valves, outflow tract septation, and parasympathetic innervation). A variety of molecular disturbances in the factors regulating the specification and differentiation of these cells can cause congenital heart disease. This review explores the contribution of different cardiac progenitors to the embryonic heart development; the pathways and transcription factors guiding their expansion, migration, and functional differentiation; and the endogenous regenerative capacity of the adult heart including the plasticity of cardiomyocytes. Unfolding these mechanisms will become the basis for understanding the dynamics of specific congenital heart disease as well as a means to develop therapy for fetal as well as postnatal cardiac defects and heart failure. PMID:26421632

  5. Optical coherence tomography. A new high-resolution imaging technology to study cardiac development in chick embryos

    DEFF Research Database (Denmark)

    Yelbuz, T.M.; Choma, M.A.; Thrane, L.;

    2002-01-01

    Background-Optical coherence tomography (OCT) is a depth-resolved, noninvasive, non-destructive imaging modality, the use of which has yet to be fully realized in developmental biology. Methods and Results-We visualized embryonic chick hearts at looping stages using an OCT system with a 22 mum...... axial and 27 mum lateral resolution and an acquisition rate of 4000 A-scans per second. Normal chick embryos from stages 14 to 22 and sham-operated and cardiac neural crest-ablated embryos from stages 15 and 18 were scanned by OCT. Three-dimensional data sets were acquired and processed to create...... volumetric reconstructions and short video clips. The OCT-scanned embryos (2 in each group) were photographed after histological sectioning in comparable planes to those visualized by OCT. The optical and histological results showing cardiovascular microstructures such as myocardium, the cardiac jelly, and...

  6. Muscle-derived stem cells isolated as non-adherent population give rise to cardiac, skeletal muscle and neural lineages

    International Nuclear Information System (INIS)

    Stem cells with the ability to differentiate in specialized cell types can be extracted from a wide array of adult tissues including skeletal muscle. Here we have analyzed a population of cells isolated from skeletal muscle on the basis of their poor adherence on uncoated or collagen-coated dishes that show multi-lineage differentiation in vitro. When analysed under proliferative conditions, these cells express stem cell surface markers Sca-1 (65%) and Bcrp-1 (80%) but also MyoD (15%), Neuronal β III-tubulin (25%), GFAP (30%) or Nkx2.5 (1%). Although capable of growing as non-attached spheres for months, when given an appropriate matrix, these cells adhere giving rise to skeletal muscle, neuronal and cardiac muscle cell lineages. A similar cell population could not be isolated from either bone marrow or cardiac tissue suggesting their specificity to skeletal muscle. When injected into damaged muscle, these non-adherent muscle-derived cells are retrieved expressing Pax7, in a sublaminar position characterizing satellite cells and participate in forming new myofibers. These data show that a non-adherent stem cell population can be specifically isolated and expanded from skeletal muscle and upon attachment to a matrix spontaneously differentiate into muscle, cardiac and neuronal lineages in vitro. Although competing with resident satellite cells, these cells are shown to significantly contribute to repair of injured muscle in vivo supporting that a similar muscle-derived non-adherent cell population from human muscle may be useful in treatment of neuromuscular disorders

  7. Cardiorespiratory effects of isoflurane anesthesia in crested caracaras (Caracara plancus).

    Science.gov (United States)

    Escobar, André; Thiesen, Roberto; Vitaliano, Sérgio N; Belmonte, Emílio A; Werther, Karin; Valadão, Carlos A A

    2011-03-01

    To evaluate the cardiorespiratory changes induced by isoflurane (ISO) anesthesia in the crested caracara (Caracara plancus), eight crested caracaras that weighed 1.0 kg (range 0.9-1.1 kg) were the subjects for the study. The birds were anesthetized by face mask with ISO for brachial artery catheterization. After recovery, anesthesia was re-induced and maintained with ISO with spontaneous ventilation. Electrocardiography, direct systolic arterial blood pressure (SAP), diastolic arterial blood pressure (DAP), mean arterial blood pressure (MAP), respiratory rate (RR), end-tidal carbon dioxide (P(ET)CO2), and cloacal temperature (T degrees C) were measured before induction (baseline, under physical restraint) and after 5, 10, 15, 20, 25, 30, 35, and 40 min of ISO anesthesia. Arterial blood samples were collected for blood gas analysis at baseline, 10, 25, and 40 min. No cardiac arrhythmias were observed in the present study. RR, SAP, DAP, MAP, T degrees C and pH decreased from baseline values, whereas arterial partial pressures of oxygen and carbon dioxide, bicarbonate concentration, and P(ET)CO2 were significantly higher than baseline. Apnea was not observed in any bird. ISO anesthesia is suitable for use in healthy members of this species despite the moderate cardiovascular and respiratory depression produced. PMID:22946364

  8. Design Guidelines for Low Crested Structures

    DEFF Research Database (Denmark)

    Burcharth, H. F.; Lamberti, Alberto

    2004-01-01

    The European Union within the Fifth Framework Programme 1998-2002 Energy, Environment andmSustainable Development sponsored the research project: Enviromnental Design of Low Crested Coastal Defence Structures (DELOS), with participation of 18 European organisations.......The European Union within the Fifth Framework Programme 1998-2002 Energy, Environment andmSustainable Development sponsored the research project: Enviromnental Design of Low Crested Coastal Defence Structures (DELOS), with participation of 18 European organisations....

  9. Combining Amplitude Spectrum Area with Previous Shock Information Using Neural Networks Improves Prediction Performance of Defibrillation Outcome for Subsequent Shocks in Out-Of-Hospital Cardiac Arrest Patients.

    Directory of Open Access Journals (Sweden)

    Mi He

    Full Text Available Quantitative ventricular fibrillation (VF waveform analysis is a potentially powerful tool to optimize defibrillation. However, whether combining VF features with additional attributes that related to the previous shock could enhance the prediction performance for subsequent shocks is still uncertain.A total of 528 defibrillation shocks from 199 patients experienced out-of-hospital cardiac arrest were analyzed in this study. VF waveform was quantified using amplitude spectrum area (AMSA from defibrillator's ECG recordings prior to each shock. Combinations of AMSA with previous shock index (PSI or/and change of AMSA (ΔAMSA between successive shocks were exercised through a training dataset including 255shocks from 99patientswith neural networks. Performance of the combination methods were compared with AMSA based single feature prediction by area under receiver operating characteristic curve(AUC, sensitivity, positive predictive value (PPV, negative predictive value (NPV and prediction accuracy (PA through a validation dataset that was consisted of 273 shocks from 100patients.A total of61 (61.0% patients required subsequent shocks (N = 173 in the validation dataset. Combining AMSA with PSI and ΔAMSA obtained highest AUC (0.904 vs. 0.819, p<0.001 among different combination approaches for subsequent shocks. Sensitivity (76.5% vs. 35.3%, p<0.001, NPV (90.2% vs. 76.9%, p = 0.007 and PA (86.1% vs. 74.0%, p = 0.005were greatly improved compared with AMSA based single feature prediction with a threshold of 90% specificity.In this retrospective study, combining AMSA with previous shock information using neural networks greatly improves prediction performance of defibrillation outcome for subsequent shocks.

  10. Generalized crested products of Markov chains

    CERN Document Server

    D'Angeli, Daniele

    2010-01-01

    We define a finite Markov chain, called generalized crested product, which naturally appears as a generalization of the first crested product of Markov chains. A complete spectral analysis is developed and the $k$-step transition probability is given. It is important to remark that this Markov chain describes a more general version of the classical Ehrenfest diffusion model. As a particular case, one gets a generalization of the classical Insect Markov chain defined on the ultrametric space. Finally, an interpretation in terms of representation group theory is given, by showing the correspondence between the spectral decomposition of the generalized crested product and the Gelfand pairs associated with the generalized wreath product of permutation groups.

  11. Flow over an Erodible Broad Crested Weir

    Directory of Open Access Journals (Sweden)

    Dr. K. C.Sahu

    2015-01-01

    Full Text Available The overtopping flow of water over an earthen embankment causes erosion of soil from its surfaces and the eroded surface of the embankment acts as a Broad crest weir. But the longitudinal profile of the weir goes on changing with time of erosion. Hence crest height of the weir goes changing in accelerated flow condition. In this paper, the discharge equation for this type of flow situation is established for different types of soils used in the embankment. Then, the experiments have been carried out as the analogous rigid beds of the captured eroded profiles at any time of erosion of the broad crested weir to compare the discharge equation and to study the energy loss in dislodging the soil from the surface of the weir and transporting them down stream.

  12. Laboratory Experiments on Low-crested Breakwaters

    DEFF Research Database (Denmark)

    Kramer, Morten; Zanuttigh, B.; van der Meer, J.W.;

    2005-01-01

    New unique laboratory experiments on low-crested structures (LCSs) have been performed within the DELOS project. The experiments were carried out in three European laboratories aiming at extending and completing existing available information with respect to a wide range of engineering design...

  13. Modified osteomyocutaneous iliac crest flaps transplantation.

    Science.gov (United States)

    Liu, Jun; Song, Dajiang; Li, Jinsong; Xu, Jian; Lv, Hongbin

    2015-04-01

    The paper aims to improve the operative technique of osteomyocutaneous iliac crest flap harvesting, further minimise morbidity of donor site, and improve the effect of recipient site reconstruction. From March 2005 to March 2011, 55 cases of osteomyocutaneous iliac crest flap harvested by different methods were performed to reconstruct the defects of the extremities. Twenty-nine cases were reconstructed with a traditional deep circumflex iliac artery osteomusculocutaneous flap. Twenty-six cases were repaired with modified osteomyocutaneous iliac crest flaps. In 29 cases with a traditional DCIA osteomusculocutaneous flap, two cases showed the injured lateral femoral cutaneous nerve. Flapnecrosis was significant in two cases. Arterial compromise occurred in one case 5 days after operation completion and led to flap failure. Three flaps developed postoperative venous congestion, but only one flap received re-exploration. In the other two cases, some stitches were removed for decompression. All three flaps survived. In two cases, marginal flap necrosis occurred, but no secondary skin grafting was required. In 26 cases with modified flap transplantation, one case showed the injured lateral femoral cutaneous nerve. All flaps survived totally. Osseous integration was achieved in all 55 cases in 3 ∼ 9 months after operation. The modified osteomyocutaneous iliac crest flap technique enhances flap safety, provides the additional advantages of reducing donor-site morbidity, and improves the recipient-site contour. PMID:25001367

  14. Migratory neuronal progenitors arise from the neural plate borders in tunicates.

    Science.gov (United States)

    Stolfi, Alberto; Ryan, Kerrianne; Meinertzhagen, Ian A; Christiaen, Lionel

    2015-11-19

    The neural crest is an evolutionary novelty that fostered the emergence of vertebrate anatomical innovations such as the cranium and jaws. During embryonic development, multipotent neural crest cells are specified at the lateral borders of the neural plate before delaminating, migrating and differentiating into various cell types. In invertebrate chordates (cephalochordates and tunicates), neural plate border cells express conserved factors such as Msx, Snail and Pax3/7 and generate melanin-containing pigment cells, a derivative of the neural crest in vertebrates. However, invertebrate neural plate border cells have not been shown to generate homologues of other neural crest derivatives. Thus, proposed models of neural crest evolution postulate vertebrate-specific elaborations on an ancestral neural plate border program, through acquisition of migratory capabilities and the potential to generate several cell types. Here we show that a particular neuronal cell type in the tadpole larva of the tunicate Ciona intestinalis, the bipolar tail neuron, shares a set of features with neural-crest-derived spinal ganglia neurons in vertebrates. Bipolar tail neuron precursors derive from caudal neural plate border cells, delaminate and migrate along the paraxial mesoderm on either side of the neural tube, eventually differentiating into afferent neurons that form synaptic contacts with both epidermal sensory cells and motor neurons. We propose that the neural plate borders of the chordate ancestor already produced migratory peripheral neurons and pigment cells, and that the neural crest evolved through the acquisition of a multipotent progenitor regulatory state upstream of multiple, pre-existing neural plate border cell differentiation programs. PMID:26524532

  15. Developmental SHP2 dysfunction underlies cardiac hypertrophy in Noonan syndrome with multiple lentigines.

    Science.gov (United States)

    Lauriol, Jessica; Cabrera, Janel R; Roy, Ashbeel; Keith, Kimberly; Hough, Sara M; Damilano, Federico; Wang, Bonnie; Segarra, Gabriel C; Flessa, Meaghan E; Miller, Lauren E; Das, Saumya; Bronson, Roderick; Lee, Kyu-Ho; Kontaridis, Maria I

    2016-08-01

    Hypertrophic cardiomyopathy is a common cause of mortality in congenital heart disease (CHD). Many gene abnormalities are associated with cardiac hypertrophy, but their function in cardiac development is not well understood. Loss-of-function mutations in PTPN11, which encodes the protein tyrosine phosphatase (PTP) SHP2, are implicated in CHD and cause Noonan syndrome with multiple lentigines (NSML), a condition that often presents with cardiac hypertrophic defects. Here, we found that NSML-associated hypertrophy stems from aberrant signaling mechanisms originating in developing endocardium. Trabeculation and valvular hyperplasia were diminished in hearts of embryonic mice expressing a human NSML-associated variant of SHP2, and these defects were recapitulated in mice expressing NSML-associated SHP2 specifically in endothelial, but not myocardial or neural crest, cells. In contrast, mice with myocardial- but not endothelial-specific NSML SHP2 expression developed ventricular septal defects, suggesting that NSML-associated mutations have both cell-autonomous and nonautonomous functions in cardiac development. However, only endothelial-specific expression of NSML-associated SHP2 induced adult-onset cardiac hypertrophy. Further, embryos expressing the NSML-associated SHP2 mutation exhibited aberrant AKT activity and decreased downstream forkhead box P1 (FOXP1)/FGF and NOTCH1/EPHB2 signaling, indicating that SHP2 is required for regulating reciprocal crosstalk between developing endocardium and myocardium. Together, our data provide functional and disease-based evidence that aberrant SHP2 signaling during cardiac development leads to CHD and adult-onset heart hypertrophy. PMID:27348588

  16. The Crest Wing Wave Energy Device

    DEFF Research Database (Denmark)

    Kofoed, Jens Peter; Antonishen, Michael Patrick

    This report presents the results of a continuation of an experimental study of the wave energy converting abilities of the Crest Wing wave energy converter (WEC), in the following referred to as ‘Phase 2'. The Crest Wing is a WEC that uses its movement in matching the shape of an oncoming wave to...... generate power. Model tests have been performed using scale models (length scale 1:30), provided by WaveEnergyFyn, in regular and irregular wave states that can be found in Assessment of Wave Energy Devices. Best Practice as used in Denmark (Frigaard et al., 2008). The tests were carried out at Dept. of...... Civil Engineering, Aalborg University (AAU) in the 3D deep water wave tank. The displacement and force applied to a power take off system, provided by WaveEnergyFyn, were measured and used to calculate mechanical power available to the power take off....

  17. CREST guide:the cognitive interview

    OpenAIRE

    Milne, Rebecca Jane

    2016-01-01

    This CREST Guide is an overview of an interviewing protocol – the Cognitive Interview – which aims to improve the recall of accurate and reliable information from interviewees. The Cognitive Interview is a theory and evidence-based approach which addresses three primary psychological processes that underlie interviews with cooperative interviewees: 1. the social dynamics between the interviewee and interviewer; 2. the interviewee’s and interviewer’s cognitive processes; and 3. communication b...

  18. Steep sharp-crested gravity waves on deep water

    OpenAIRE

    Lukomsky, Vasyl'; Gandzha, Ivan,; Lukomsky, Dmytro

    2001-01-01

    A new type of steady steep two-dimensional irrotational symmetric periodic gravity waves on inviscid incompressible fluid of infinite depth is revealed. We demonstrate that these waves have sharper crests in comparison with the Stokes waves of the same wavelength and steepness. The speed of a fluid particle at the crest of new waves is greater than their phase speed.

  19. Vesicularity of basalt erupted at Reykjanes Ridge crest

    Science.gov (United States)

    Duffield, W.A.

    1978-01-01

    Average vesicularity of basalt drilled at three sites on the west flank of the Reykjanes Ridge increases with decreasing age. This change apparently records concomitant decrease in water depth at the ridge crest where the basalt was erupted and suggests substantial upward growth of the crest during the past 35 Myr. ?? 1978 Nature Publishing Group.

  20. Lessons learned from the EU project T-CREST

    DEFF Research Database (Denmark)

    Schoeberl, Martin

    2016-01-01

    A three year EU project, such a T-CREST, with partners from all over Europe and with backgrounds from different domains is a challenging endeavor. Successful execution of such a project depends on more factors than simply performing excellent research. Within the three-year project T-CREST eight...

  1. Stability of Cubipod Armoured Roundheads in Short Crested Waves

    DEFF Research Database (Denmark)

    Burcharth, Hans F.; Andersen, Thomas Lykke; Medina, Josep R.

    2011-01-01

    The paper presents a comparison of the stability of concrete cube armour and Cubipod armour in a breakwater roundhead with slope 1:1.5, exposed to both 2-D (long-crested) and 3-D (short-crested) waves. The model tests were performed at the Hydraulics and Coastal Engineering Laboratory at Aalborg ...

  2. Crested wheatgrass control and monitoring Benton Lake Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Crested wheatgrass CWG was planted on Benton Lake NWR at least 30 years ago, presumably to stabilize the soil where it had been disturbed in the process of building...

  3. Flow structure in front of the broad-crested weir

    Directory of Open Access Journals (Sweden)

    Zachoval Zbyněk

    2015-01-01

    Full Text Available The paper deals with research focused on description of flow structure in front of broad-crested weir. Based on experimental measurement, the flow structure in front of the weir (the recirculation zone of flow and tornado vortices and flow structure on the weir crest has been described. The determined flow character has been simulated using numerical model and based on comparing results the suitable model of turbulence has been recommended.

  4. Introducing Big Sagebrush into a Crested Wheatgrass Monoculture

    OpenAIRE

    Newhall, Robert L; Rasmussen, V. Philip, Jr.; Kitchen, Boyd M

    2011-01-01

    Crested wheatgrass (Agropyron desertorum or A. cristatum) has been effectively used to stabilize arid and semi-arid range sites for decades. Reestablishing native plant materials into these areas is often desirable to increase wildlife habitat and ecological diversity. Due to its competitive nature, efforts to reestablish native plants into crested wheatgrass monocultures have had limited success. Tillage will control the grass but leaves the soil vulnerable to erosion and weed invasion. This...

  5. CREST: Climate REconstruction SofTware

    Science.gov (United States)

    Chevalier, M.; Cheddadi, R.; Chase, B. M.

    2014-02-01

    Several methods currently exist to quantitatively reconstruct palaeoclimatic variables from fossil botanical data. Of these, pdf-based (probability density functions) methods have proven valuable as they can be applied to a wide range of plants assemblages. Most commonly applied to fossil pollen data, their performance, however, can be limited by the taxonomic resolution of the pollen data, as many species may belong to a given pollen-type. Consequently, the climate information associated with different species cannot sometimes not be precisely identified, resulting less accurate reconstructions. This can become particularly problematic in regions of high biodiversity. In this paper, we propose a novel pdf-based method that takes into account the different climatic requirements of each species constituting the broader pollen-type. Pdfs are fitted in two successive steps, with parametric pdfs fitted first for each species, and then a combination of those individual species pdfs into a broader single pdf to represent the pollen-type as a unit. A climate value for the pollen assemblage is estimated from the likelihood function obtained after the multiplication of the pollen-type pdfs, with each being weighted according to its pollen percentage. To test the robustness of the method, we have applied the method to southern Africa as a regional case study, and reconstructed a suite of climatic variables based on extensive botanical data derived from herbarium collections. The reconstructions proved to be accurate for both temperature and precipitation. Predictable exceptions were areas that experience conditions at the extremes of the regional climatic spectra. Importantly, the accuracy of the reconstructed values is independent from the vegetation type where the method is applied or the number of species used. The method used in this study is publicly available in a software package entitled CREST (Climate REconstruction SofTware) and will provide the opportunity to

  6. CREST: Climate REconstruction SofTware

    Directory of Open Access Journals (Sweden)

    M. Chevalier

    2014-02-01

    Full Text Available Several methods currently exist to quantitatively reconstruct palaeoclimatic variables from fossil botanical data. Of these, pdf-based (probability density functions methods have proven valuable as they can be applied to a wide range of plants assemblages. Most commonly applied to fossil pollen data, their performance, however, can be limited by the taxonomic resolution of the pollen data, as many species may belong to a given pollen-type. Consequently, the climate information associated with different species cannot sometimes not be precisely identified, resulting less accurate reconstructions. This can become particularly problematic in regions of high biodiversity. In this paper, we propose a novel pdf-based method that takes into account the different climatic requirements of each species constituting the broader pollen-type. Pdfs are fitted in two successive steps, with parametric pdfs fitted first for each species, and then a combination of those individual species pdfs into a broader single pdf to represent the pollen-type as a unit. A climate value for the pollen assemblage is estimated from the likelihood function obtained after the multiplication of the pollen-type pdfs, with each being weighted according to its pollen percentage. To test the robustness of the method, we have applied the method to southern Africa as a regional case study, and reconstructed a suite of climatic variables based on extensive botanical data derived from herbarium collections. The reconstructions proved to be accurate for both temperature and precipitation. Predictable exceptions were areas that experience conditions at the extremes of the regional climatic spectra. Importantly, the accuracy of the reconstructed values is independent from the vegetation type where the method is applied or the number of species used. The method used in this study is publicly available in a software package entitled CREST (Climate REconstruction SofTware and will provide the

  7. CREST--classification resources for environmental sequence tags.

    Directory of Open Access Journals (Sweden)

    Anders Lanzén

    Full Text Available Sequencing of taxonomic or phylogenetic markers is becoming a fast and efficient method for studying environmental microbial communities. This has resulted in a steadily growing collection of marker sequences, most notably of the small-subunit (SSU ribosomal RNA gene, and an increased understanding of microbial phylogeny, diversity and community composition patterns. However, to utilize these large datasets together with new sequencing technologies, a reliable and flexible system for taxonomic classification is critical. We developed CREST (Classification Resources for Environmental Sequence Tags, a set of resources and tools for generating and utilizing custom taxonomies and reference datasets for classification of environmental sequences. CREST uses an alignment-based classification method with the lowest common ancestor algorithm. It also uses explicit rank similarity criteria to reduce false positives and identify novel taxa. We implemented this method in a web server, a command line tool and the graphical user interfaced program MEGAN. Further, we provide the SSU rRNA reference database and taxonomy SilvaMod, derived from the publicly available SILVA SSURef, for classification of sequences from bacteria, archaea and eukaryotes. Using cross-validation and environmental datasets, we compared the performance of CREST and SilvaMod to the RDP Classifier. We also utilized Greengenes as a reference database, both with CREST and the RDP Classifier. These analyses indicate that CREST performs better than alignment-free methods with higher recall rate (sensitivity as well as precision, and with the ability to accurately identify most sequences from novel taxa. Classification using SilvaMod performed better than with Greengenes, particularly when applied to environmental sequences. CREST is freely available under a GNU General Public License (v3 from http://apps.cbu.uib.no/crest and http://lcaclassifier.googlecode.com.

  8. Flow characteristics at trapezoidal broad-crested side weir

    Directory of Open Access Journals (Sweden)

    Říha Jaromír

    2015-06-01

    Full Text Available Broad-crested side weirs have been the subject of numerous hydraulic studies; however, the flow field at the weir crest and in front of the weir in the approach channel still has not been fully described. Also, the discharge coefficient of broad-crested side weirs, whether slightly inclined towards the stream or lateral, still has yet to be clearly determined. Experimental research was carried out to describe the flow characteristics at low Froude numbers in the approach flow channel for various combinations of in- and overflow discharges. Three side weir types with different oblique angles were studied. Their flow characteristics and discharge coefficients were analyzed and assessed based on the results obtained from extensive measurements performed on a hydraulic model. The empirical relation between the angle of side weir obliqueness, Froude numbers in the up- and downstream channels, and the coefficient of obliqueness was derived.

  9. Observations of highly localized oscillons with multiple crests and troughs

    CERN Document Server

    LI, Xiaochen; Liao, Shijun

    2014-01-01

    Stable, highly localized Faraday's resonant standing waves with multiple crests and troughs were observed in the alcoholic solution partly filled in a Hele-Shaw cell vertically oscillated with a single frequency. Two types of oscillons were observed. The influence of the experimental parameters (such as the concentration of alcoholic solution, the water depth, the frequency and acceleration amplitude of oscillation) on these oscillons were investigated in details. In the same experimental parameters, all of these oscillons have the almost same wave height but rather irregular crest-to-crest distances. Our experiments highly suggest that the complicated oscillons can be regarded as combination of the two elementary oscillons discovered by Rajchenbach et al. (Physical Review Letters, 107, 2011).

  10. CREST - a large and diverse superfamily of putative transmembrane hydrolases

    Directory of Open Access Journals (Sweden)

    Olson Eric N

    2011-07-01

    Full Text Available Abstract Background A number of membrane-spanning proteins possess enzymatic activity and catalyze important reactions involving proteins, lipids or other substrates located within or near lipid bilayers. Alkaline ceramidases are seven-transmembrane proteins that hydrolyze the amide bond in ceramide to form sphingosine. Recently, a group of putative transmembrane receptors called progestin and adipoQ receptors (PAQRs were found to be distantly related to alkaline ceramidases, raising the possibility that they may also function as membrane enzymes. Results Using sensitive similarity search methods, we identified statistically significant sequence similarities among several transmembrane protein families including alkaline ceramidases and PAQRs. They were unified into a large and diverse superfamily of putative membrane-bound hydrolases called CREST (alkaline ceramidase, PAQR receptor, Per1, SID-1 and TMEM8. The CREST superfamily embraces a plethora of cellular functions and biochemical activities, including putative lipid-modifying enzymes such as ceramidases and the Per1 family of putative phospholipases involved in lipid remodeling of GPI-anchored proteins, putative hormone receptors, bacterial hemolysins, the TMEM8 family of putative tumor suppressors, and the SID-1 family of putative double-stranded RNA transporters involved in RNA interference. Extensive similarity searches and clustering analysis also revealed several groups of proteins with unknown function in the CREST superfamily. Members of the CREST superfamily share seven predicted core transmembrane segments with several conserved sequence motifs. Conclusions Universal conservation of a set of histidine and aspartate residues across all groups in the CREST superfamily, coupled with independent discoveries of hydrolase activities in alkaline ceramidases and the Per1 family as well as results from previous mutational studies of Per1, suggests that the majority of CREST members are

  11. The CREST reactive-burn model for explosives

    OpenAIRE

    Maheswaran M-A.; Lambourn B.; James H.; Whitworth N.; Handley C.

    2011-01-01

    CREST is an innovative reactive-burn model that has been developed at AWE for simulating shock initiation and detonation propagation behaviour in explosives. The model has a different basis from other reactive-burn models in that its reaction rate is independent of local flow variables behind the shock wave e.g. pressure and temperature. The foundation for CREST, based on a detailed analysis of data from particle-velocity gauge experiments, is that the reaction rate depends only on the local ...

  12. Artificial neural network modeling enhances risk stratification and can reduce downstream testing for patients with suspected acute coronary syndromes, negative cardiac biomarkers, and normal ECGs.

    Science.gov (United States)

    Isma'eel, Hussain A; Cremer, Paul C; Khalaf, Shaden; Almedawar, Mohamad M; Elhajj, Imad H; Sakr, George E; Jaber, Wael A

    2016-04-01

    Despite uncertain yield, guidelines endorse routine stress myocardial perfusion imaging (MPI) for patients with suspected acute coronary syndromes, unremarkable serial electrocardiograms, and negative troponin measurements. In these patients, outcome prediction and risk stratification models could spare unnecessary testing. This study therefore investigated the use of artificial neural networks (ANN) to improve risk stratification and prediction of MPI and angiographic results. We retrospectively identified 5354 consecutive patients referred from the emergency department for rest-stress MPI after serial negative troponins and normal ECGs. Patients were risk stratified according to thrombolysis in myocardial infarction (TIMI) scores, ischemia was defined as >5 % reversible perfusion defect, and obstructive coronary artery disease was defined as >50 % angiographic obstruction. For ANN, the network architecture employed a systematic method where the number of neurons is changed incrementally, and bootstrapping was performed to evaluate the accuracy of the models. Compared to TIMI scores, ANN models provided improved discriminatory power. With regards to MPI, an ANN model could reduce testing by 59 % and maintain a 96 % negative predictive value (NPV) for ruling out ischemia. Application of an ANN model could also avoid 73 % of invasive coronary angiograms while maintaining a 98 % NPV for detecting obstructive CAD. An online calculator for clinical use was created using these models. The ANN models improved risk stratification when compared to the TIMI score. Our calculator could also reduce downstream testing while maintaining an excellent NPV, though further study is needed before the calculator can be used clinically. PMID:26626458

  13. Induced Pluripotent Stem Cells for Neural Tissue Engineering

    OpenAIRE

    Wang, Aijun; Tang, Zhenyu; Park, In-Hyun; Zhu, Yiqian; Patel, Shyam; Daley, George Q.; Song, Li

    2011-01-01

    Induced pluripotent stem cells (iPSCs) hold great promise for cell therapies and tissue engineering. Neural crest stem cells (NCSCs) are multipotent and represent a valuable system to investigate iPSC differentiation and therapeutic potential. Here we derived NCSCs from human iPSCs and embryonic stem cells (ESCs), and investigated the potential of NCSCs for neural tissue engineering. The differentiation of iPSCs and the expansion of derived NCSCs varied in different cell lines, but all NCSC l...

  14. Neural defects and cardiac arrhythmia in fish larvae following embryonic exposure to 2,2',4,4'-tetrabromodiphenyl ether (PBDE 47).

    Science.gov (United States)

    Lema, Sean C; Schultz, Irvin R; Scholz, Nathaniel L; Incardona, John P; Swanson, Penny

    2007-05-31

    Polybrominated diphenyl ethers (PBDEs) are added to plastics, polyurethane foam, and textiles as a flame retardant. While PBDEs play a key role in reducing loss of human life and property from fires, these flame retardants have become pervasive organic contaminants in the environment and in the tissues of fish, birds, marine mammals, and humans. Levels of PBDEs in wildlife and humans continue to rise, raising concerns about potential ecological and health risks associated with exposure to these chemicals. Nevertheless, there is little currently known about the toxicological effects of PBDE exposure. Here, we examined the developmental toxicity of the PBDE congener 2,2',4,4'-tetrabromodiphenyl ether (PBDE 47) using the zebrafish (Danio rerio) as an ontogenetic model. Zebrafish embryos were exposed continuously to dissolved phase PBDE 47 (100-5000 microg/l) beginning 3-5 h post-fertilization (hpf). Fish treated with the highest concentrations of PBDE 47 delayed hatching, had reduced growth post-hatching, and displayed an abnormal dorsal curvature of the body with flexion at the hindbrain. By 96h post-fertilization larvae exposed to PBDE 47 had significant tachycardia, which progressed into atrioventricular block arrhythmias. Microinjection of fluorescent dye into the hindbrain ventricle revealed that cerebrospinal fluid in the neural tube and brain ventricles flowed more slowly in fish larvae exposed to PBDE 47, a likely etiology for the dorsal curvature. Similar, though much less pronounced, developmental toxicity also occurred in larvae exposed to PBDE 47 only for a 20h period during early embryogenesis (3-23 hpf), suggesting that PBDEs incorporated in lipid of the egg are bioavailable and cause toxicity later in life. Taken together, this work indicates that exposure to PBDE 47 can cause morphological abnormalities, impair cardiovascular function and cerebrospinal fluid flow, and provides a tractable starting point for using the zebrafish model to explore

  15. The CREST reactive-burn model for explosives

    Directory of Open Access Journals (Sweden)

    Maheswaran M-A.

    2011-01-01

    Full Text Available CREST is an innovative reactive-burn model that has been developed at AWE for simulating shock initiation and detonation propagation behaviour in explosives. The model has a different basis from other reactive-burn models in that its reaction rate is independent of local flow variables behind the shock wave e.g. pressure and temperature. The foundation for CREST, based on a detailed analysis of data from particle-velocity gauge experiments, is that the reaction rate depends only on the local shock strength and the time since the shock passed. Since a measure of shock strength is the entropy of the non-reacted explosive, which remains constant behind a shock, CREST uses an entropy-dependent reaction rate. This paper will provide an overview of the CREST model and its predictive capability. In particular, it will be shown that the model can predict a wide range of experimental phenomena for both shock initiation (e.g. the effects of porosity and initial temperature on sustained-shock and thin-flyer initiation and detonation propagation (e.g. the diameter effect curve and detonation failure cones using a single set of coefficients.

  16. Flexibility of neural stem cells

    Directory of Open Access Journals (Sweden)

    EumorphiaRemboutsika

    2011-04-01

    Full Text Available Embryonic cortical neural stem cells are self-renewing progenitors that can differentiate into neurons and glia. We generated neurospheres from the developing cerebral cortex using a mouse genetic model that allows for lineage selection and found that the self-renewing neural stem cells are restricted to Sox2 expressing cells. Under normal conditions, embryonic cortical neurospheres are heterogeneous with regard to Sox2 expression and contain astrocytes, neural stem cells and neural progenitor cells sufficiently plastic to give rise to neural crest cells when transplanted into the hindbrain of E1.5 chick and E8 mouse embryos. However, when neurospheres are maintained under lineage selection, such that all cells express Sox2, neural stem cells maintain their Pax6+ cortical radial glia identity and exhibit a more restricted fate in vitro and after transplantation. These data demonstrate that Sox2 preserves the cortical identity and regulates the plasticity of self-renewing Pax6+ radial glia cells.

  17. Cardiac rehabilitation

    Science.gov (United States)

    ... attack or other heart problem. You might consider cardiac rehab if you have had: Heart attack Coronary heart disease (CHD) Heart failure Angina (chest pain) Heart or heart valve surgery Heart transplant Procedures such as angioplasty and stenting In some ...

  18. Cardiac Rehabilitation

    Science.gov (United States)

    Cardiac rehabilitation (rehab) is a medically supervised program to help people who have A heart attack Angioplasty or coronary artery bypass grafting for coronary heart disease A heart valve repair or replacement A ...

  19. Cardiac sarcoidosis

    OpenAIRE

    Costello BT; Nadel J.; Taylor AJ

    2016-01-01

    Benedict T Costello,1,2 James Nadel,3 Andrew J Taylor,1,21Department of Cardiovascular Medicine, The Alfred Hospital, 2Baker IDI Heart and Diabetes Research Institute, Melbourne, VIC, 3School of Medicine, University of Notre Dame, Sydney, NSW, Australia Abstract: Cardiac sarcoidosis is a rare but life-threatening condition, requiring a high degree of clinical suspicion and low threshold for investigation to make the diagnosis. The cardiac manifestations include heart failure, conducting syst...

  20. Cardiac CT

    Energy Technology Data Exchange (ETDEWEB)

    Dewey, Marc [Charite - Universitaetsmedizin Berlin (Germany). Inst. fuer Radiologie

    2011-07-01

    Computed tomography of the heart has become a highly accurate diagnostic modality that is attracting increasing attention. This extensively illustrated book aims to assist the reader in integrating cardiac CT into daily clinical practice, while also reviewing its current technical status and applications. Clear guidance is provided on the performance and interpretation of imaging using the latest technology, which offers greater coverage, better spatial resolution, and faster imaging. The specific features of scanners from all four main vendors, including those that have only recently become available, are presented. Among the wide range of applications and issues to be discussed are coronary artery bypass grafts, stents, plaques, and anomalies, cardiac valves, congenital and acquired heart disease, and radiation exposure. Upcoming clinical uses of cardiac CT, such as plaque imaging and functional assessment, are also explored. (orig.)

  1. Cardiac echinococcosis

    Directory of Open Access Journals (Sweden)

    Ivanović-Krstić Branislava A.

    2002-01-01

    Full Text Available Cardiac hydatid disease is rare. We report on an uncommon hydatid cyst localized in the right ventricular wall, right atrial wall tricuspid valve left atrium and pericard. A 33-year-old woman was treated for cough, fever and chest pain. Cardiac echocardiograpic examination revealed a round tumor (5.8 x 4 cm in the right ventricular free wall and two smaller cysts behind that tumor. There were cysts in right atrial wall and tricuspidal valve as well. Serologic tests for hydatidosis were positive. Computed tomography finding was consistent with diagnosis of hydatid cyst in lungs and right hylar part. Surgical treatment was rejected due to great risk of cardiac perforation. Medical treatment with albendazole was unsuccessful and the patient died due to systemic hydatid involvement of the lungs, liver and central nervous system.

  2. Numerical analysis of divertor plasma for demo-CREST

    International Nuclear Information System (INIS)

    The numerical analysis of the demonstration fusion reactor Demo-CREST has been carried out; this analysis focuses on impurity seeding. Several design activities for DEMO have been carried out; however, its detailed divertor plasma analysis remains to be carried out. Therefore, in this study, we discuss the possibility of neon puffing in demo-CREST to decrease the power load to the divertor plate by using the B2-EIRENE code. It has been shown that the radiation power loss by neon increases with upstream plasma density and that the peak power load to the divertor plate comes close to the allowable level by using the preliminary divertor configuration (copyright 2010 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  3. Hydraulic Evaluation of the Crest Wing Wave Energy Converter

    DEFF Research Database (Denmark)

    Kofoed, Jens Peter; Antonishen, Michael Patrick

    This report presents the results of an experimental study of the wave energy converting abilities of the Crest Wing wave energy converter (WEC). The Crest Wing is a WEC that uses its movement in matching the shape of an oncoming wave to generate power. Model tests have been performed using a scale...... model (length scale 1:30), provided by WaveEnergyFyn, in regular and irregular wave states that can be found in Assessment of Wave Energy Devices. Best Practice as used in Denmark (Frigaard et al., 2008). The tests were carried out at Dept. of Civil Engineering, Aalborg (Frigaard et al., 2008). The...... tests were carried out at Dept. of Civil Engineering, Aalborg University (AAU) in the 3D deep water wave tank. The displacement and force applied to a power take off system, provided by WaveEnergyFyn, were measured and used to calculate total power take off....

  4. Facial expression recognition in crested macaques (Macaca nigra)

    OpenAIRE

    Micheletta, Jérôme; Whitehouse, Jamie; Parr, Lisa A.; Bridget M Waller

    2015-01-01

    Facial expressions are a main communication channel used by many different species of primate. Despite this, we know relatively little about how primates discriminate between different facial expressions, and most of what we do know comes from a restricted number of well-studied species. In this study, three crested macaques (Macaca nigra) took part in matching-to-sample tasks where they had to discriminate different facial expressions. In a first experiment, the macaques had to match a photo...

  5. Lumbar Incisional Hernia Repair After Iliac Crest Bone Graft

    OpenAIRE

    Do, Michael V.; Richardson, William S.

    2012-01-01

    The iliac crest is a common donor site for autogenous bone grafts. Among the reported complications, lumbar hernias occur infrequently with a reported incidence of 5% to 9%. Surgical repair is advocated secondary to the risk of incarceration or strangulation. Computed tomography is the diagnostic study of choice. Various transabdominal, retroperitoneal, and laparoscopic approaches have been described for the repair of lumbar hernias. We describe a case of successful lumbar incisional hernia r...

  6. Cardiac sarcoidosis

    Science.gov (United States)

    Smedema, J.P.; Zondervan, P.E.; van Hagen, P.; ten Cate, F.J.; Bresser, P.; Doubell, A.F.; Pattynama, P.; Hoogsteden, H.C.; Balk, A.H.M.M.

    2002-01-01

    Sarcoidosis is a multi-system granulomatous disorder of unknown aetiology. Symptomatic cardiac involvement occurs in approximately 5% of patients. The prevalence of sarcoidosis in the Netherlands is unknown, but estimated to be approximately 20 per 100,000 population (3200 patients). We report on five patients who presented with different manifestations of cardiac sarcoidosis, and give a brief review on the current management of this condition. Magnetic Resonance Imaging (MRI) can be of great help in diagnosing this condition as well as in the follow-up of the response to therapy. ImagesFigure 1Figure 2Figure 3Figure 4Figure 5Figure 6 PMID:25696121

  7. MR imaging findings of medial tibial crest friction

    Energy Technology Data Exchange (ETDEWEB)

    Klontzas, Michail E., E-mail: miklontzas@gmail.com; Akoumianakis, Ioannis D., E-mail: ioannis.akoumianakis@gmail.com; Vagios, Ilias, E-mail: iliasvagios@gmail.com; Karantanas, Apostolos H., E-mail: akarantanas@gmail.com

    2013-11-01

    Objective: Medial tibial condyle bone marrow edema (BME), associated with soft tissue edema (STe) surrounding the medial collateral ligament, was incidentally observed in MRI examinations of young and athletic individuals. The aim of the present study was to 1. Prospectively investigate the association between these findings and coexistence of localized pain, and 2. Explore the possible contribution of the tibial morphology to its pathogenesis. Methods: The medial tibial condyle crest was evaluated in 632 knee MRI examinations. The angle and depth were measured by two separate evaluators. The presence of STe and BME was recorded. A third evaluator blindly assessed the presence of pain at this site. Results: BME associated with STe was found in 24 patients (with no history of previous trauma, osteoarthritis, tumor or pes anserine bursitis). The mean crest angle was 151.3° (95%CI 147.4–155.3°) compared to 159.4° (95%CI 158.8–160°) in controls (Mann–Whitney test, P < 0.0001). MRI findings were highly predictive of localized pain (sensitivity 92% specificity 99%, Fisher's exact test, P < 0.0001). Conclusion: Friction at the medial tibial condyle crest is a painful syndrome. MRI is a highly specific and sensitive imaging modality for its diagnosis.

  8. Cardiac Pacemakers

    International Nuclear Information System (INIS)

    A complete survey of physiological biophysical,clinical and engineering aspects of cardiac facing,including the history and an assessment of possible future developments.Among the topics studied are: pacemakers, energy search, heart stimulating with pacemakers ,mathematical aspects of the electric cardio stimulation chronic, pacemaker implants,proceeding,treatment and control

  9. A rare case of lumbar hernia following iliac crest bone graft

    OpenAIRE

    2013-01-01

    Introduction: Harvesting bone graft from iliac crest is routine procedure in orthopaedics practice. Lumbar hernia following this procedure is rare. Lumbar hernia is classified as congenital, primary, post traumatic and incisional. Objective: Reporting herewith a case of right lumbar hernia in 58 years old female occurring 10 years following full thickness iliac crest bone graft. Conclusion: Iliac crest bone harvest needs to be performed meticulously to prevent postoperative hernia. If occurs,...

  10. Cardiac rhabdomyosarcoma

    OpenAIRE

    Chlumský, Jaromír; Holá, Dana; Hlaváček, Karel; Michal, Michal; Švec, Alexander; Špatenka, Jaroslav; Dušek, Jan

    2001-01-01

    Cardiac sarcoma is a very rare neoplasm and is difficult to diagnose. The case of a 51-year-old man with a left atrial tumour, locally recurrent three months after its surgical removal, is presented. Computed tomography showed metastatic spread to the lung parenchyma. On revised histology, the mass extirpated was a sarcoma. Because of the metastatic spread, further therapy was symptomatic only; the patient died 15 months after the first manifestation of his problems. Immunohistochemical stain...

  11. Cardiac Calcification

    Directory of Open Access Journals (Sweden)

    Morteza Joorabian

    2011-05-01

    Full Text Available There is a spectrum of different types of cardiac"ncalcifications with the importance and significance"nof each type of cardiac calcification, especially"ncoronary artery calcification. Radiologic detection of"ncalcifications within the heart is quite common. The"namount of coronary artery calcification correlates"nwith the severity of coronary artery disease (CAD."nCalcification of the aortic or mitral valve may indicate"nhemodynamically significant valvular stenosis."nMyocardial calcification is a sign of prior infarction,"nwhile pericardial calcification is strongly associated"nwith constrictive pericarditis. A spectrum of different"ntypes of cardiac calcifications (linear, annular,"ncurvilinear,... could be seen in chest radiography and"nother imaging modalities. So a carful inspection for"ndetection and reorganization of these calcifications"nshould be necessary. Numerous modalities exist for"nidentifying coronary calcification, including plain"nradiography, fluoroscopy, intravascular ultrasound,"nMRI, echocardiography, and conventional, helical and"nelectron-beam CT (EBCT. Coronary calcifications"ndetected on EBCT or helical CT can be quantifie,"nand a total calcification score (Cardiac Calcification"nScoring may be calculated. In an asymptomatic"npopulation and/or patients with concomitant risk"nfactors like diabetes mellitus, determination of the"npresence of coronary calcifications identifies the"npatients at risk for future myocardial infarction and"ncoronary artery disease. In patients without coronary"ncalcifications, future cardiovascular events could"nbe excluded. Therefore, detecting and recognizing"ncalcification related to the heart on chest radiography"nand other imaging modalities such as fluoroscopy, CT"nand echocardiography may have important clinical"nimplications.

  12. Tinea Incognita in a Patient with Crest Syndrome: Case Report.

    Science.gov (United States)

    Gorgievska-Sukarovska, Biljana; Skerlev, Mihael; Žele-Starčević, Lidija

    2015-01-01

    Tinea incognita is a dermatophytic infection that is difficult to diagnose, usually modified by inappropriate topical or systemic corticosteroid therapy. We report an extensive case of tinea incognita caused by the zoophilic dermatophyte Trichophyton mentagrophytes (var. granulosa) in a 49-year-old female patient with CREST (Calcinosis; Raynaud phenomenon; Esophageal involvement; Sclerodactyly; Teleangiectasia) syndrome. Immunocompromised patients, as well as patients with keratinization disorders, seem to be especially susceptible to dermatophytic infections with atypical clinical presentation that is sometimes bizarre and difficult to recognize. Therefore, close monitoring and mycological skin examination is recommended in order to avoid misdiagnosis and to give the patient the best chance of recovery. PMID:26476904

  13. Multielement analysis of iliac crest bone by neutron activation

    International Nuclear Information System (INIS)

    Bone samples from iliac crest were obtained from apparently healthy female (n = 4) and male (n = 8) subjects with ages between 15-50. Cortical and trabecular parts were separated and soft tissues like fat, muscle and blood were removed. Calcium, Mg, Na, Cl, Fe, Zn, Br, Sr, and Cs were determined by instrumental neutron activation analysis and other techniques, and their relations were discussed. Fairly good agreement was obtained with literature data. These values may serve as reference values for subjects from a Turkish population. (author)

  14. Isotopic Discrimination in the Double-Crested Cormorant (Phalacrocorax auritus.

    Directory of Open Access Journals (Sweden)

    Elizabeth C Craig

    Full Text Available The diet-tissue discrimination factor is the amount by which a consumer's tissue varies isotopically from its diet, and is therefore a key element in models that use stable isotopes to estimate diet composition. In this study we measured discrimination factors in blood (whole blood, red blood cells and plasma, liver, muscle and feathers of Double-crested Cormorants (Phalacrocorax auritus for stable isotope ratios of carbon, nitrogen and sulfur. Cormorants exhibited discrimination factors that differed significantly among tissue types (for carbon and nitrogen, and differed substantially (in the context of the isotopic variation among relevant prey species from those observed in congeneric species. The Double-crested Cormorant has undergone rapid population expansion throughout much of its historic range over the past three decades, leading to both real and perceived conflicts with fisheries throughout North America, and this study provides an essential link for the use of stable isotope analysis in researching foraging ecology, diet, and resource use of this widespread and controversial species.

  15. Determinants of immigration strategies in male crested macaques (Macaca nigra).

    Science.gov (United States)

    Marty, Pascal R; Hodges, Keith; Agil, Muhammad; Engelhardt, Antje

    2016-01-01

    Immigration into a new group can produce substantial costs due to resistance from residents, but also reproductive benefits. Whether or not individuals base their immigration strategy on prospective cost-benefit ratios remains unknown. We investigated individual immigration decisions in crested macaques, a primate species with a high reproductive skew in favour of high-ranking males. We found two different strategies. Males who achieved low rank in the new group usually immigrated after another male had immigrated within the previous 25 days and achieved high rank. They never got injured but also had low prospective reproductive success. We assume that these males benefitted from immigrating into a destabilized male hierarchy. Males who achieved high rank in the new group usually immigrated independent of previous immigrations. They recieved injuries more frequently and therefore bore immigration costs. They, however, also had higher reproductive success prospects. We conclude that male crested macaques base their immigration strategy on relative fighting ability and thus potential rank in the new group i.e. potential reproductive benefits, as well as potential costs of injury. PMID:27535622

  16. Cardiac conduction system

    Science.gov (United States)

    The cardiac conduction system is a group of specialized cardiac muscle cells in the walls of the heart that send signals ... to contract. The main components of the cardiac conduction system are the SA node, AV node, bundle ...

  17. CRANIAL NEURAL CREST CELLS ON THE MOVE: THEIR ROLES IN CRANIOFACIAL DEVELOPMENT

    OpenAIRE

    Cordero, Dwight R; Brugmann, Samantha; Chu, Yvonne; Bajpai, Ruchi; Jame, Maryam; Helms, Jill A.

    2011-01-01

    The craniofacial region is assembled through the active migration of cells and the rearrangement and sculpting of facial prominences and pharyngeal arches, which consequently make it particularly susceptible to a large number of birth defects. Genetic, molecular, and cellular processes must be temporally and spatially regulated to culminate in the three-dimension structures of the face. The starting constituent for the majority of skeletal and connective tissues in the face is a pluripotent p...

  18. CHD7, the gene mutated in CHARGE syndrome, regulates genes involved in neural crest cell guidance

    NARCIS (Netherlands)

    Schulz, Yvonne; Wehner, Peter; Opitz, Lennart; Salinas-Riester, Gabriela; Bongers, Ernie M. H. F.; van Ravenswaaij-Arts, Conny M. A.; Wincent, Josephine; Schoumans, Jacqueline; Kohlhase, Juergen; Borchers, Annette; Pauli, Silke

    2014-01-01

    Heterozygous loss of function mutations in CHD7 (chromodomain helicase DNA-binding protein 7) lead to CHARGE syndrome, a complex developmental disorder affecting craniofacial structures, cranial nerves and several organ systems. Recently, it was demonstrated that CHD7 is essential for the formation

  19. Elk3 is essential for the progression from progenitor to definitive neural crest cell

    OpenAIRE

    Rogers, Crystal D.; Phillips, Jacquelyn L.; Bronner, Marianne E.

    2013-01-01

    Elk3/Net/Sap2 (here referred to as Elk3) is an Ets ternary complex transcriptional repressor known for its involvement in angiogenesis during embryonic development. Although Elk3 is expressed in various tissues, additional roles for the protein outside of vasculature development have yet to be reported. Here, we characterize the early spatiotemporal expression pattern of Elk3 in the avian embryo using whole mount in situ hybridization and quantitative RT-PCR and examine the effects of its los...

  20. Noggin can mimic BMPs effects on early neural crest-derived mesenchyme

    Czech Academy of Sciences Publication Activity Database

    Buchtová, M.; Celá, Petra; Bálek, L.; Procházková, J.; Richman, J. M.

    Cancun : Intarnational Society of Developmentasl Biologists, 2013. s. 99-99. [International Congress of Developmental Biology /17./. 16.06.2013-20.06.2013, Cancun] R&D Projects: GA ČR GA304/09/0725 Institutional support: RVO:67985904 Keywords : bone morphogenetic protein Subject RIV: FF - HEENT, Dentistry

  1. FLOW OVER A BROAD-CRESTED WEIR IN SUBCRITICAL FLOW CONDITIONS, PHYSICAL STUDY

    Directory of Open Access Journals (Sweden)

    seyed hooman hoseini

    2014-01-01

    Full Text Available Weirs are a small overflow-type dams commonly used to raise the level of a river or stream and cause a large change of water level behind them. The use of portable instrument like kinds of weirs, flumes, floats, and volumetric tank are common. Discharges measured range from a trickle in ditch to a flood on the Amazon. Many researchers have studied the head discharge relations for flows over sharp-crested weirs and broad-crested weirs with a simple cross section shape, such as rectangular, triangular, trapezoidal, truncated triangular, and others Basic experiments were conducted on rectangular broad-crested weirs with different geometry. It was found that the discharge coefficient of a rectangular broad-crested weir is related to upstream total head above the crest, length of weir and Channel breadth. Multiple regression analysis equations based on the dimensional analysis concept were developed for computing the discharge coefficient of a rectangular broad-crested weirs and discharge coefficient equation was used for computing the discharge over the broad-crested weirs. Good agreements between the measured values and the values computed from the predictive equation are obtained. Therefore, a reliable equation for calculating the discharge coefficient of rectangular broad-crested weirs in subcritical flow conditions is presented.

  2. Conditional Second Order Short-crested Water Waves Applied to Extreme Wave Episodes

    DEFF Research Database (Denmark)

    Jensen, Jørgen Juncher

    2005-01-01

    A derivation of the mean second order short-crested wave pattern and associated wave kinematics, conditional on a given magnitude of the wave crest, is presented. The analysis is based on the second order Sharma and Dean finite water wave theory. A comparison with a measured extreme wave profile...

  3. Medical image of the week: CREST plus ILD

    Directory of Open Access Journals (Sweden)

    Oliva I

    2013-06-01

    Full Text Available A 60 year old female with a history of fibromyalgia presented with dyspnea and skin changes, predominantly on the hands. Physical exam and imaging showed classic findings of limited cutaneous systemic sclerosis (scleroderma CREST syndrome. Calcinosis cutis (Figure 1A, Raynaud’s (not shown but endorsed by the patient, Esophageal dysmotility (Figure 1B, dilated esophagus, Sclerodactyly (Figure 1C, and Teleganectasias (Figure 1D were all present. Ground glass opacities were seen predominantly in the bilateral lower lung zones, associated with increased reticular markings (Figure 2A, and traction bronchiectasis (Figure 2B. Pulmonary involvement is noted in the majority of scleroderma patients. Interstitial lung disease (ILD is common and often portends a poor prognosis.

  4. Hycrest crested wheatgrass accelerates the degradation of pentachlorophenol in soil

    Science.gov (United States)

    Ferro, A. M.; Sims, R. C.; Bugbee, B.

    1994-01-01

    We investigated the effects of vegetation on the fate of pentachlorophenol (PCP) in soil using a novel high-flow sealed test system. Pentachlorophenol has been widely used as a wood preservative, and this highly toxic biocide contaminates soil and ground water at many sites. Although plants are known to accelerate the rates of degradation of certain soil contaminants, this approach has not been thoroughly investigated for PCP. The fate of [14C]PCP, added to soil at a concentration of 100 mg/kg, was compared in three unplanted and three planted systems. The plant used was Hycrest, a perennial, drought-tolerant cultivar of crested wheatgrass [Agropyron desertorum (Fischer ex Link) Schultes]. The flow-through test system allowed us to maintain a budget for 14C-label as well as monitor mineralization (breakdown to 14CO2) and volatilization of the test compound in a 155-d trial. In the unplanted systems, an average of 88% of the total radiolabel remained in the soil and leachate and only 6% was mineralized. In the planted system, 33% of the radiolabel remained in the soil plus leachate, 22% was mineralized, and 36% was associated with plant tissue (21% with the root fraction and 15% with shoots). Mineralization rates were 23.1 mg PCP mineralized kg-1 soil in 20 wk in the planted system, and for the unplanted system 6.6 mg PCP kg-1 soil for the same time period. Similar amounts of volatile organic material were generated in the two systems (1.5%). Results indicated that establishing crested wheatgrass on PCP-contaminated surface soils may accelerate the removal of the contaminant.

  5. Cardiac MRI in Athletes

    NARCIS (Netherlands)

    Luijkx, T.

    2012-01-01

    Cardiac magnetic resonance imaging (CMR) is often used in athletes to image cardiac anatomy and function and is increasingly requested in the context of screening for pathology that can cause sudden cardiac death (SCD). In this thesis, patterns of cardiac adaptation to sports are investigated with C

  6. Cardiac perception and cardiac control. A review.

    Science.gov (United States)

    Carroll, D

    1977-12-01

    The evidence regarding specific cardiac perception and discrimination, and its relationship to voluntary cardiac control, is critically reviewed. Studies are considered in three sections, depending on the method used to assess cardiac perception: questionnaire assessment, discrimination procedures, and heartbeat tracking. The heartbeat tracking procedure would appear to suffer least from interpretative difficulties. Recommendations are made regarding the style of analysis used to assess heartbeat perception in such tracking tasks. PMID:348240

  7. Static histomorphometry of human iliac crest and vertebral trabecular bone: a comparative study

    DEFF Research Database (Denmark)

    Thomsen, Jesper Skovhus; Ebbesen, Ebbe Nils; Mosekilde, Lis

    2002-01-01

    years) had a known vertebral fracture of L-2. The iliac crest biopsies and 9-mm-thick mediolateral slices of half the entire vertebral bodies were embedded in methylmetacrylate, stained with aniline blue, and scanned into a computer with a flatbed image scanner at a high resolution. With a custom......We recently developed a new, rapid method for conducting static histomorphometry on large histologic sections. This method has now been applied on both iliac crest and lumbar vertebral bone to compare the age-related changes at these two skeletal sites and to investigate the correlation between the...... histomorphometric measures at the iliac crest and the vertebral body. The material comprised matched sets of unilateral transiliac crest bone biopsies and lumbar vertebral bodies (L-2) from 24 women (19-96 years) and 24 men (23-95 years) selected from a larger autopsy material. Three female subjects (80, 88, and 90...

  8. Sex-related gene and sex identification of Crested Ibis Nipponia nippon (Ciconiiformes: Threskiornithidae)

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The Crested Ibis (Nipponia nippon) is a critical endangeredspecies of the world. At present, a reintroduction program will be conducted to save this species essentially. However, because the Crested Ibise is a sexual alike bird, it is very difficult to identify the sex from the morphological character. In order to identify the sex easily and select the right individuals for captive breeding and reintroduction, the sex related gene on W chromosome was amplified and the sex of three Crested Ibises were also identified in the present study. The 262bp fragment was also sequenced, and we found that there were 13 different nucleotide sites with 2.25 of transition/transversion based on the comparison with that of the Oriental White Stork. The sequence will also provide a theoretic base for further designing specific primer for sex related gene in the Crested Ibis.

  9. 78 FR 26358 - Eagle Mountain Pumped Storage Hydroelectric Project, Eagle Crest Energy; Notice of Meeting With...

    Science.gov (United States)

    2013-05-06

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Eagle Mountain Pumped Storage Hydroelectric Project, Eagle Crest Energy...), on the Eagle Mountain Pumped Storage Hydroelectric Project. e. All local, state, and federal...

  10. 76 FR 22393 - Eagle Mountain Pumped Storage Hydroelectric Project, Eagle Crest Energy; Notice of Cancellation...

    Science.gov (United States)

    2011-04-21

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Eagle Mountain Pumped Storage Hydroelectric Project, Eagle Crest Energy... and Wildlife Service for the proposed Eagle Mountain Pumped Storage Hydroelectric Project....

  11. 77 FR 47628 - Eagle Mountain Pumped Storage Hydroelectric Project; Eagle Crest Energy; Notice of Meeting...

    Science.gov (United States)

    2012-08-09

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Eagle Mountain Pumped Storage Hydroelectric Project; Eagle Crest Energy... Management Act and the Federal Power Act), on the Eagle Mountain Pumped Storage Hydroelectric...

  12. 2009 update to crested wheatgrass control and monitoring Benton Lake Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Crested wheatgrass CWG was planted on Benton Lake NWR at least 30 years ago, presumably to stabilize the soil where it had been disturbed in the process of building...

  13. 2010 update to crested wheatgrass control and monitoring Benton Lake Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Crested wheatgrass CWG was planted on Benton Lake NWR at least 30 years ago, presumably to stabilize the soil where it had been disturbed in the process of building...

  14. 2011 update to crested wheatgrass control and monitoring Benton Lake Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Crested wheatgrass CWG was planted on Benton Lake NWR at least 30 years ago, presumably to stabilize the soil where it had been disturbed in the process of building...

  15. Biology of nesting crested, least, and whiskered auklets at Buldir Island, Alaska

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — During avifaunal investigations at Buldir Island 1974-1976, some aspects of the biology of Crested, Least, and Whiskered Auklets were investigated in a colony where...

  16. Probing dark matter crests with white dwarfs and IMBHs

    CERN Document Server

    Amaro-Seoane, Pau; Schödel, Rainer; Davidson, Emily; Cuadra, Jorge

    2015-01-01

    White dwarfs (WDs) are the most promising captors of dark matter (DM) particles in the crests that are expected to build up in the cores of dense stellar clusters. The DM particles could reach sufficient densities in WD cores to liberate energy through self-annihilation. The extinction associated with our Galactic Centre, the most promising region where to look for such effects, makes it impossible to detect the potential associated luminosity of the DM-burning WDs. However, in smaller stellar systems which are close enough to us and not heavily extincted, such as $\\omega-$Cen, we may be able to detect DM-burning WDs. We investigate the prospects of detection of DM-burning WDs in a stellar cluster harbouring an IMBH, which leads to higher densities of DM at the centre as compared with clusters without one. We calculate the capture rate of WIMPs by a WD around an IMBH and estimate the luminosity that a WD would emit depending on its distance to the center of the cluster. Direct-summation $N-$body simulations o...

  17. Crest factor optimization of the multisine waveform for bioimpedance spectroscopy

    International Nuclear Information System (INIS)

    The multisine excitation is widely used in impedance measurements to retain the advantages of the sine wave, while reducing the measurement time. Adding up sine waves increases the amplitude of the excitation signal, but, for the linearity assumption to be valid, the overall amplitude of the signal needs to be kept low. Thus, the crest factor (CF) of the excitation signal must be minimized. A novel empirical method for the minimization of the CF is described in this paper. As in the case of other known methods, the computed CF may be guaranteed to be only a local minimum. However, a systematic variation of initial parameters, which is possible due to the sparing algorithm, ensures a CF value very close or equal to the global minimum. The results of CF minimization and comparison with the results from other sources are provided. The direct CF optimization results (set of optimal phases) are not well suited for practical implementation. The influence of phase accuracy on the CF is discussed, and an algorithm for the recalculation of initial phases to the rougher set is described. It is shown that previously obtained optimization results (minimal CF) can be highly preserved, even in the case of rough phase resolutions. The CF of the multisine also depends on the frequency distribution and amplitudes of its components. The CF of multisines with several frequency distributions are compared. (paper)

  18. Maintenance and radiation protection issues of the CREST reactor

    International Nuclear Information System (INIS)

    A maintenance approach of the Compact Reversed Shear Tokamak (CREST) for high availability is proposed. Full sector removal through horizontal ports for easy maintenance is adopted in order to increase availability. Cask type sector removal machines are used to transfer the blanket/divertor sectors. Achievable availability is estimated with a maintenance period and its interval. The proposed maintenance approach allows, at least, the similar availability to that of the present nuclear plants. The estimated availability is acceptable from an economical viewpoint. Safety concerns related to the super-heated direct steam cycle are also examined. One of the unique concerns is due to nitrogen-16 production in the coolant. The super-heated steam must flow through the turbines within several 10 s after leaving the blanket. The requirements for shielding on the heat transfer systems are declared. Another concern is the confinement and recovery of tritium in the coolant, because a high temperature blanket may have a large tritium permeation rate. Water detritiation system proposed here would be able to control the tritium concentration in the coolant within an allowable range

  19. Nodular regenerative hyperplasia of the liver, CREST syndrome and primary biliary cirrhosis: an overlap syndrome?

    OpenAIRE

    McMahon, R F; Babbs, C.; Warnes, T W

    1989-01-01

    Nodular regenerative hyperplasia of the liver (NRHL) has been found in association with collagen vascular diseases, after drug therapy, with autoimmune disease, and with a variety of haematological disorders. The association of NRHL with the syndrome of Calcinosis cutis, Raynaud's phenomenon, oesophageal dysfunction, sclerodactyly and telangiectasia (CREST syndrome) has only been reported on two previous occasions. The liver disease usually associated with CREST syndrome is primary biliary ci...

  20. STUDY ON THE RELATIONSHIP AMONG THE HEART MERIDIAN,CARDIAC REFERRED PAIN AND THE HEART

    Institute of Scientific and Technical Information of China (English)

    RONG Peijing; ZHU Bing

    2002-01-01

    @@ Purpose: The referred pain of the somatic structure, a response of the visceralgia, is often seen in clinic. But its underlying mechanisms are poorly understood. It is interested that cardiac referred pain often appears along the running course of the Heart Meridian (HM), while acupuncture of the acupoints of HM can effectively relieve cardiac pain. In the present study, the neural basis of the relationship among the HM, cardiac referred pain and the heart is investigated by using tri-labeling technique.

  1. Common arterial trunk and ventricular non-compaction in Lrp2 knockout mice indicate a crucial role of LRP2 in cardiac development

    NARCIS (Netherlands)

    Baardman, Maria E.; Zwier, Mathijs V.; Wisse, Lambertus J.; Gittenberger-de Groot, Adriana C.; Kerstjens-Frederikse, Wilhelmina S.; Hofstra, Robert M. W.; Jurdzinski, Angelika; Hierck, Beerend P.; Jongbloed, Monique R. M.; Berger, Rolf M. F.; Plosch, Torsten; DeRuiter, Marco C.

    2016-01-01

    Lipoprotein-related receptor protein 2 (LRP2) is important for development of the embryonic neural crest and brain in both mice and humans. Although a role in cardiovascular development can be expected, the hearts of Lrp2 knockout (KO) mice have not yet been investigated. We studied the cardiovascul

  2. BASIC CRITERIA OF IRANIAN COMMERCIAL TOOTHPASTES AND AN ADA APPROVED BRAND (CREST

    Directory of Open Access Journals (Sweden)

    N NOUR BAKHSH

    2003-03-01

    Full Text Available Introduction: The effectiveness of fluorided toothpastes in reducing dental caries is well-documented, However not all fluorided toothpastes are equally effective. The objective of this study was to compare some essential criteria of six different toothpastes manufactured in Iran with one brand of ADA approved toothpaste (Crest. Methods. Six commercial toothpastes produced in Iran named as Paveh, Puneh, Nasim, Darugar, golpasand and saviz were compared with Crest in three subjects as follows: 1. Amount of fluoride concentration 2. Amount of releasing fluoride 3. Cleaning efficiency. Two first criteria were tested using the potentiometric method with F- Ion specific electrode, and Cleaning efficiency was done by O'Leary index on 60 volunteers (10 for each toothpaste. Results: Fluoride Concentration in Paveh, Puneh, Nasim toothpastes were nearly700PPM,while in three others were much lower. The highest amount of fluoride was seen in Crest (1450 PPM. Cleaning efficiency of Darugar was better than Crest, Paveh, Puneh. Cleaning efficiency of Nasim was the same as Crest and Golpasand and Saviz were weaker than Crest. Discussion: Since at the present time, the most effective, Cost-benefit method for preventive aspects of fluoride, especially in developing countries is obtained by fluoride toothpastes. Manufactures should improve quality of fluoride toothpastes, ensure that all pates maximize Fluoride bioavailability, develop active agents to help better cleaning efficiency and label products clearly with containig fluoride in PPM.

  3. What Is Cardiac Rehabilitation?

    Science.gov (United States)

    ANSWERS by heart Treatments + Tests What Is Cardiac Rehabilitation? A cardiac rehabilitation (rehab) program takes place in a hospital or ... special help in making lifestyle changes. During your rehabilitation program you’ll… • Have a medical evaluation to ...

  4. Convergent Evolution of Head Crests in Two Domesticated Columbids Is Associated with Different Missense Mutations in EphB2.

    Science.gov (United States)

    Vickrey, Anna I; Domyan, Eric T; Horvath, Martin P; Shapiro, Michael D

    2015-10-01

    Head crests are important display structures in wild bird species and are also common in domesticated lineages. Many breeds of domestic rock pigeon (Columba livia) have crests of reversed occipital feathers, and this recessive trait is associated with a nonsynonymous coding mutation in the intracellular kinase domain of EphB2 (Ephrin receptor B2). The domestic ringneck dove (Streptopelia risoria) also has a recessive crested morph with reversed occipital feathers, and interspecific crosses between crested doves and pigeons produce crested offspring, suggesting a similar genetic basis for this trait in both species. We therefore investigated EphB2 as a candidate for the head crest phenotype of ringneck doves and identified a nonsynonymous coding mutation in the intracellular kinase domain that is significantly associated with the crested morph. This mutation is over 100 amino acid positions away from the crest mutation found in rock pigeons, yet both mutations are predicted to negatively affect the function of ATP-binding pocket. Furthermore, bacterial toxicity assays suggest that "crest" mutations in both species severely impact kinase activity. We conclude that head crests are associated with different mutations in the same functional domain of the same gene in two different columbid species, thereby representing striking evolutionary convergence in morphology and molecules. PMID:26104009

  5. Diffuse infiltrative cardiac tuberculosis

    International Nuclear Information System (INIS)

    We present the cardiac magnetic resonance images of an unusual form of cardiac tuberculosis. Nodular masses in a sheet-like distribution were seen to infiltrate the outer myocardium and pericardium along most of the cardiac chambers. The lesions showed significant resolution on antitubercular therapy

  6. Facial expression recognition in crested macaques (Macaca nigra).

    Science.gov (United States)

    Micheletta, Jérôme; Whitehouse, Jamie; Parr, Lisa A; Waller, Bridget M

    2015-07-01

    Facial expressions are a main communication channel used by many different species of primate. Despite this, we know relatively little about how primates discriminate between different facial expressions, and most of what we do know comes from a restricted number of well-studied species. In this study, three crested macaques (Macaca nigra) took part in matching-to-sample tasks where they had to discriminate different facial expressions. In a first experiment, the macaques had to match a photograph of a facial expression to another exemplar of the same expression produced by a different individual, against examples of one of three other types of expressions and neutral faces. In a second experiment, they had to match a dynamic video recording of a facial expression to a still photograph of another exemplar of the same facial expression produced by another individual, also against one of four other expressions. The macaques performed above chance in both tasks, identifying expressions as belonging to the same category regardless of individual identity. Using matrix correlations and multidimensional scaling, we analysed the pattern of errors to see whether overall similarity between facial expressions and/or specific morphological features caused the macaques to confuse facial expressions. Overall similarity, measured with the macaque facial action coding system (maqFACS), did not correlate with performances. Instead, functional similarities between facial expressions could be responsible for the observed pattern of error. These results expand previous findings to a novel primate species and highlight the potential of using video stimuli to investigate the perception and categorisation of visual signals in primates. PMID:25821924

  7. Probing dark matter crests with white dwarfs and IMBHs

    Science.gov (United States)

    Amaro-Seoane, P.; Casanellas, J.; Schödel, R.; Davidson, E.; Cuadra, J.

    2016-06-01

    White dwarfs (WDs) are the most promising captors of dark matter (DM) particles in the crests that are expected to build up in the cores of dense stellar clusters. The DM particles could reach sufficient densities in WD cores to liberate energy through self-annihilation. The extinction associated with our Galactic Centre makes it impossible to detect the potential-associated luminosities, contrary to smaller stellar systems which are close enough to us and not heavily extincted, such as -Cen. We investigate the prospects of detection of DM-burning WDs in a stellar cluster harbouring an intermediate-mass black hole (IMBH), which leads to higher densities of DM at the centre. We calculate the capture rate and estimate the luminosity that a WD would emit depending on its distance to the centre of the cluster. Direct-summation N-body simulations of -Cen yield a non-negligible number of WDs in the range of radii of interest. We apply our assumption to published Hubble Space Telescope/Advanced Camera for Surveys observations of stars in the centre of -Cen and, although we are not able to identify any evident candidate, we proof that their bunching up at high luminosities would be unique. We predict that DM burning will lead to a truncation of the cooling sequence at the faint end. The detection of DM burning in future observations of dense stellar clusters could allow us to probe different models of DM distributions and characteristics. On the other hand, if DM-burning WDs really exist, their number and properties could give hints to the existence of IMBHs.

  8. Neural Networks

    International Nuclear Information System (INIS)

    Physicists use large detectors to measure particles created in high-energy collisions at particle accelerators. These detectors typically produce signals indicating either where ionization occurs along the path of the particle, or where energy is deposited by the particle. The data produced by these signals is fed into pattern recognition programs to try to identify what particles were produced, and to measure the energy and direction of these particles. Ideally, there are many techniques used in this pattern recognition software. One technique, neural networks, is particularly suitable for identifying what type of particle caused by a set of energy deposits. Neural networks can derive meaning from complicated or imprecise data, extract patterns, and detect trends that are too complex to be noticed by either humans or other computer related processes. To assist in the advancement of this technology, Physicists use a tool kit to experiment with several neural network techniques. The goal of this research is interface a neural network tool kit into Java Analysis Studio (JAS3), an application that allows data to be analyzed from any experiment. As the final result, a physicist will have the ability to train, test, and implement a neural network with the desired output while using JAS3 to analyze the results or output. Before an implementation of a neural network can take place, a firm understanding of what a neural network is and how it works is beneficial. A neural network is an artificial representation of the human brain that tries to simulate the learning process [5]. It is also important to think of the word artificial in that definition as computer programs that use calculations during the learning process. In short, a neural network learns by representative examples. Perhaps the easiest way to describe the way neural networks learn is to explain how the human brain functions. The human brain contains billions of neural cells that are responsible for processing

  9. A statistical study of equatorial ionospheric anomaly single crest from SWARM satellite

    Science.gov (United States)

    Fathy, Adel; Ghamry, Essam

    2016-07-01

    However the, the Equatorial Ionospheric Anomaly (EIA) is being represented by two crests within ±15 degree in latitudes, a single crest is being observed in the entire ionosphere. A statistical study of 1351 EIA single crest for ionospheric electron density from SWARM-A satellite are investigated within the interval April 2014 to April 2015. Our analysis focused on local time, seasonal and both geographic and geomagnetic latitudinal variations in addition EIA amplitude with respect to solar and geomagnetic activities. Our results showed that the maximum number of EIA single crest events peak mainly in the dayside region around 1000-1200 LT. The electron density amplitude of the EIA single crest events in the dayside region jumps to 3 times its dawn and nightside amplitude. Spring events observed very close to the magnetic equator in comparison to other seasons. Their maximum number occurs within the magnetic equator, while their seasonal distribution showed that the majority of winter events located in the southern hemisphere, while spring events are centered around the magnetic equator. Regardless of local time or longitudinal location of summer events, it always has smaller amplitude in comparison with other seasons. Seasonal distribution showed that the average number of EIA single crests per month is approximately 200 events with relatively large number of events in September than March. Also it showed two maxima at spring and autumn, and two minima at summer and winter. The average magnetic latitude of summer events is +10 degrees in northern hemisphere. The majority of dawnside and nightside summer events is located in northern hemisphere and reverses its location in winter, while dayside and duskside events seem to be centered within the magnetic equator. The EIA solar and magnetic activity dependence showed that almost EIA single crest events occurred at low and moderate activity which is in partial agreement with previous studies and dayside events

  10. The Investigation of EM Scattering from the Time-Varying Overturning Wave Crest Model by the IEM

    Directory of Open Access Journals (Sweden)

    Xiao Meng

    2016-01-01

    Full Text Available Investigation of the electromagnetic (EM scattering of time-varying overturning wave crests is a worthwhile endeavor. Overturning wave crest is one of the reasons of sea spike generation, which increases the probability of false radar alarms and reduces the performance of multitarget detection in the environment. A three-dimensional (3D time-varying overturning wave crest model is presented in this paper; this 3D model is an improvement of the traditional two-dimensional (2D time-varying overturning wave crest model. The integral equation method (IEM was employed to investigate backward scattering radar cross sections (RCS at various incident angles of the 3D overturning wave crest model. The super phenomenon, where the intensity of horizontal polarization scattering is greater than that of vertical polarization scattering, is an important feature of sea spikes. Simulation results demonstrate that super phenomena may occur in some time samples as variations in the overturning wave crest.

  11. Cardiac tumours in children

    Directory of Open Access Journals (Sweden)

    Parsons Jonathan M

    2007-03-01

    Full Text Available Abstract Cardiac tumours are benign or malignant neoplasms arising primarily in the inner lining, muscle layer, or the surrounding pericardium of the heart. They can be primary or metastatic. Primary cardiac tumours are rare in paediatric practice with a prevalence of 0.0017 to 0.28 in autopsy series. In contrast, the incidence of cardiac tumours during foetal life has been reported to be approximately 0.14%. The vast majority of primary cardiac tumours in children are benign, whilst approximately 10% are malignant. Secondary malignant tumours are 10–20 times more prevalent than primary malignant tumours. Rhabdomyoma is the most common cardiac tumour during foetal life and childhood. It accounts for more than 60% of all primary cardiac tumours. The frequency and type of cardiac tumours in adults differ from those in children with 75% being benign and 25% being malignant. Myxomas are the most common primary tumours in adults constituting 40% of benign tumours. Sarcomas make up 75% of malignant cardiac masses. Echocardiography, Computing Tomography (CT and Magnetic Resonance Imaging (MRI of the heart are the main non-invasive diagnostic tools. Cardiac catheterisation is seldom necessary. Tumour biopsy with histological assessment remains the gold standard for confirmation of the diagnosis. Surgical resection of primary cardiac tumours should be considered to relieve symptoms and mechanical obstruction to blood flow. The outcome of surgical resection in symptomatic, non-myxomatous benign cardiac tumours is favourable. Patients with primary cardiac malignancies may benefit from palliative surgery but this approach should not be recommended for patients with metastatic cardiac tumours. Surgery, chemotherapy and radiotherapy may prolong survival. The prognosis for malignant primary cardiac tumours is generally extremely poor.

  12. Long-term culture and differentiation of CNS precursors derived from anterior human neural rosettes following exposure to ventralizing factors

    International Nuclear Information System (INIS)

    In this study we demonstrated that neural rosettes derived from human ES cells can give rise either to neural crest precursors, following expansion in presence of bFGF and EGF, or to dopaminergic precursors after exposure to ventralizing factors Shh and FGF8. Both regionalised precursors are capable of extensive proliferation and differentiation towards the corresponding terminally differentiated cell types. In particular, peripheral neurons, cartilage, bone, smooth muscle cells and also pigmented cells were obtained from neural crest precursors while tyrosine hydroxylase and Nurr1 positive dopaminergic neurons were derived from FGF8 and Shh primed rosette cells. Gene expression and immunocytochemistry analyses confirmed the expression of dorsal and neural crest genes such as Sox10, Slug, p75, FoxD3, Pax7 in neural precursors from bFGF-EGF exposed rosettes. By contrast, priming of rosettes with FGF8 and Shh induced the expression of dopaminergic markers Engrailed1, Pax2, Pitx3, floor plate marker FoxA2 and radial glia markers Blbp and Glast, the latter in agreement with the origin of dopaminergic precursors from floor plate radial glia. Moreover, in vivo transplant of proliferating Shh/FGF8 primed precursors in parkinsonian rats demonstrated engraftment and terminal dopaminergic differentiation. In conclusion, we demonstrated the derivation of long-term self-renewing precursors of selected regional identity as potential cell reservoirs for cell therapy applications, such as CNS degenerative diseases, or for the development of toxicological tests.

  13. Long-term culture and differentiation of CNS precursors derived from anterior human neural rosettes following exposure to ventralizing factors

    Energy Technology Data Exchange (ETDEWEB)

    Colleoni, Silvia, E-mail: silviacolleoni@avantea.it [Laboratorio di Tecnologie della Riproduzione, Avantea, Via Porcellasco 7/f, 26100 Cremona (Italy); Galli, Cesare [Laboratorio di Tecnologie della Riproduzione, Avantea, Via Porcellasco 7/f, 26100 Cremona (Italy); Dipartimento Clinico Veterinario, Universita di Bologna, Via Tolara di Sopra 50, 40064 Ozzano Emilia (Italy); Giannelli, Serena G. [Stem Cells and Neurogenesis Unit, Division of Neuroscience, San Raffaele Scientific Institute, Via Olgettina 58, 20132 Milan (Italy); Armentero, Marie-Therese; Blandini, Fabio [Laboratory of Functional Neurochemistry, Interdepartmental Research Center for Parkinson' s Disease, Neurological Institute C. Mondino, Via Mondino 2, 27100 Pavia (Italy); Broccoli, Vania, E-mail: broccoli.vania@hsr.it [Stem Cells and Neurogenesis Unit, Division of Neuroscience, San Raffaele Scientific Institute, Via Olgettina 58, 20132 Milan (Italy); Lazzari, Giovanna, E-mail: giovannalazzari@avantea.it [Laboratorio di Tecnologie della Riproduzione, Avantea, Via Porcellasco 7/f, 26100 Cremona (Italy)

    2010-04-15

    In this study we demonstrated that neural rosettes derived from human ES cells can give rise either to neural crest precursors, following expansion in presence of bFGF and EGF, or to dopaminergic precursors after exposure to ventralizing factors Shh and FGF8. Both regionalised precursors are capable of extensive proliferation and differentiation towards the corresponding terminally differentiated cell types. In particular, peripheral neurons, cartilage, bone, smooth muscle cells and also pigmented cells were obtained from neural crest precursors while tyrosine hydroxylase and Nurr1 positive dopaminergic neurons were derived from FGF8 and Shh primed rosette cells. Gene expression and immunocytochemistry analyses confirmed the expression of dorsal and neural crest genes such as Sox10, Slug, p75, FoxD3, Pax7 in neural precursors from bFGF-EGF exposed rosettes. By contrast, priming of rosettes with FGF8 and Shh induced the expression of dopaminergic markers Engrailed1, Pax2, Pitx3, floor plate marker FoxA2 and radial glia markers Blbp and Glast, the latter in agreement with the origin of dopaminergic precursors from floor plate radial glia. Moreover, in vivo transplant of proliferating Shh/FGF8 primed precursors in parkinsonian rats demonstrated engraftment and terminal dopaminergic differentiation. In conclusion, we demonstrated the derivation of long-term self-renewing precursors of selected regional identity as potential cell reservoirs for cell therapy applications, such as CNS degenerative diseases, or for the development of toxicological tests.

  14. Modified theoretical stage-discharge relation for circular sharp-crested weirs

    Directory of Open Access Journals (Sweden)

    Rasool GHOBADIAN

    2012-03-01

    Full Text Available A circular sharp-crested weir is a circular control section used for measuring flow in open channels, reservoirs, and tanks. As flow measuring devices in open channels, these weirs are placed perpendicular to the sides and bottoms of straight-approach channels. Considering the complex patterns of flow passing over circular sharp-crested weirs, an equation having experimental correlation coefficients was used to extract a stage-discharge relation for weirs. Assuming the occurrence of critical flow over the weir crest, a theoretical stage-discharge relation was obtained in this study by solving two extracted non-linear equations. To study the precision of the theoretical stage-discharge relation, 58 experiments were performed on six circular weirs with different diameters and crest heights in a 30 cm-wide flume. The results show that, for each stage above the weirs, the theoretically calculated discharge is less than the measured discharge, and this difference increases with the stage. Finally, the theoretical stage-discharge relation was modified by exerting a correction coefficient which is a function of the ratio of the upstream flow depth to the weir crest height. The results show that the modified stage-discharge relation is in good agreement with the measured results.

  15. Adenocarcinoma of the third portion of the duodenum in a man with CREST syndrome

    Directory of Open Access Journals (Sweden)

    Fragulidis Georgios

    2008-10-01

    Full Text Available Abstract Background CREST (Calcinosis, Raynaud's phenomenon, Esophageal dysmotility, Sclerodactyly and Telangiectasias syndrome has been rarely associated with other malignancies (lung, esophagus.This is the first report of a primary adenocarcinoma of the third portion of the duodenum in a patient with CREST syndrome. Case presentation A 54-year-old male patient with CREST syndrome presented with colicky postprandial pain of the upper abdomen, diminished food uptake and a 6-Kg-body weight loss during the previous 2 months. An ulcerative lesion in the third portion of the duodenum was revealed during duodenoscopy, with a diagnosis of adenocarcinoma on biopsy specimen histology. The patient underwent a partial pancreatoduodenectomy. No adjuvant therapy was instituted and follow-up is negative for local recurrence or metastases 21 months postoperatively. Conclusion CREST syndrome has been associated with colon cancer, gastric polyps, familial adenomatous polyposis (FAP syndrome and Crohn's disease; however, this is the first report of a primary adenocarcinoma of the duodenum in a patient with CREST syndrome. However, any etiologic relationship remains to be further investigated.

  16. 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.

  17. Parasympathetic neural activity accounts for the lowering of exercise heart rate at high altitude

    DEFF Research Database (Denmark)

    Boushel, Robert Christopher; Calbet, J A; Rådegran, G; Sondergaard, H; Wagner, Poul Erik; Saltin, B

    2001-01-01

    In chronic hypoxia, both heart rate (HR) and cardiac output (Q) are reduced during exercise. The role of parasympathetic neural activity in lowering HR is unresolved, and its influence on Q and oxygen transport at high altitude has never been studied.......In chronic hypoxia, both heart rate (HR) and cardiac output (Q) are reduced during exercise. The role of parasympathetic neural activity in lowering HR is unresolved, and its influence on Q and oxygen transport at high altitude has never been studied....

  18. Short-crested waves in deep water: a numerical investigation of recent laboratory experiments

    DEFF Research Database (Denmark)

    Fuhrman, David R.; Madsen, Per A.

    2006-01-01

    A numerical study of quasi-steady, doubly-periodic monochromatic short-crested wave patterns in deep water is conducted using a high-order Boussinesq-type model. Simulations using linear wavemaker conditions in the nonlinear model are initially used to approximate conditions from recent laboratory...... experiments. The computed patterns share many features with those observed in wavetanks, including bending (both frontwards and backwards) of the wave crests, dipping at the crest centerlines, and a pronounced long modulation in the direction of propagation. A new and simple explanation for these features is...... provided, involving the release of spurious free first harmonics, due to the neglect of steady third-order components in the three-dimensional wave generation. A comparison with the experimentally observed beat length and amplitude matches the theoretical/numerical predictions well. Additionally, direct...

  19. Preoperative cardiac risk management

    OpenAIRE

    Vidaković Radosav; Poldermans Don; Nešković Aleksandar N.

    2011-01-01

    Approximately 100 million people undergo noncardiac surgery annually worldwide. It is estimated that around 3% of patients undergoing noncardiac surgery experience a major adverse cardiac event. Although cardiac events, like myocardial infarction, are major cause of perioperative morbidity or mortality, its true incidence is difficult to assess. The risk of perioperative cardiac complications depends mainly on two conditions: 1) identified risk factors, and 2) the type of the surgical p...

  20. NEURAL CRYPTOGRAPHY

    OpenAIRE

    PROTIC DANIJELA D.

    2016-01-01

    Neural cryptography based on the tree parity machine (TPM) is presented in this paper. A mutual learning-based synchronization of two networks is studied. The training of the TPM based on the Hebbian, anti-Hebbian and random walk as well as on the secure key generation protocol is described. The most important attacks on the key generation process are shown.

  1. Neurally Derived Tissues in Xenopus laevis Embryos Exhibit a Consistent Bioelectrical Left-Right Asymmetry

    OpenAIRE

    Pai, Vaibhav P.; Vandenberg, Laura N.; Douglas Blackiston; Michael Levin

    2012-01-01

    Consistent left-right asymmetry in organ morphogenesis is a fascinating aspect of bilaterian development. Although embryonic patterning of asymmetric viscera, heart, and brain is beginning to be understood, less is known about possible subtle asymmetries present in anatomically identical paired structures. We investigated two important developmental events: physiological controls of eye development and specification of neural crest derivatives, in Xenopus laevis embryos. We found that the str...

  2. CREST v2.1 Refined by a Distributed Linear Reservoir Routing Scheme

    Science.gov (United States)

    Shen, X.; Hong, Y.; Zhang, K.; Hao, Z.; Wang, D.

    2014-12-01

    Hydrologic modeling is important in water resources management, and flooding disaster warning and management. Routing scheme is among the most important components of a hydrologic model. In this study, we replace the lumped LRR (linear reservoir routing) scheme used in previous versions of the distributed hydrological model, CREST (coupled routing and excess storage) by a newly proposed distributed LRR method, which is theoretically more suitable for distributed hydrological models. Consequently, we have effectively solved the problems of: 1) low values of channel flow in daily simulation, 2) discontinuous flow value along the river network during flood events and 3) irrational model parameters. The CREST model equipped with both the routing schemes have been tested in the Gan River basin. The distributed LRR scheme has been confirmed to outperform the lumped counterpart by two comparisons, hydrograph validation and visual speculation of the continuity of stream flow along the river: 1) The CREST v2.1 (version 2.1) with the implementation of the distributed LRR achieved excellent result of [NSCE(Nash coefficient), CC (correlation coefficient), bias] =[0.897, 0.947 -1.57%] while the original CREST v2.0 produced only negative NSCE, close to zero CC and large bias. 2) CREST v2.1 produced more naturally smooth river flow pattern along the river network while v2.0 simulated bumping and discontinuous discharge along the mainstream. Moreover, we further observe that by using the distributed LRR method, 1) all model parameters fell within their reasonable region after an automatic optimization; 2) CREST forced by satellite-based precipitation and PET products produces a reasonably well result, i.e., (NSCE, CC, bias) = (0.756, 0.871, -0.669%) in the case study, although there is still room to improve regarding their low spatial resolution and underestimation of the heavy rainfall events in the satellite products.

  3. SMOOTH MUSCLE STEM CELLS

    Science.gov (United States)

    Vascular smooth muscle cells (SMCs) originate from multiple types of progenitor cells. In the embryo, the most well-studied SMC progenitor is the cardiac neural crest stem cell. Smooth muscle differentiation in the neural crest lineage is controlled by a combination of cell intrinsic factors, includ...

  4. Avulsion fracture of the iliac crest in a child☆☆☆

    Science.gov (United States)

    Mortati, Rafael Borghi; Borghi Mortati, Lucas; Silva Teixeira, Matheus; Itiro Takano, Marcelo; Armelin Borger, Richard

    2014-01-01

    Avulsion fractures of the apophysis of the iliac crest have rare incidence and are little known. In this article, we report the case of an 11-year-old female patient who presented this injury after indirect trauma. From careful radiographic analysis, an avulsion fracture of the iliac crest was identified. It was decided to use nonsurgical treatment comprising analgesia and load restriction. This case report emphasizes the importance of suspecting avulsion fractures in cases of low-energy trauma, and also guides the treatment, so as to prevent functional deficit and deformities. PMID:26229818

  5. Ethanol regulates calcium channels in clonal neural cells.

    OpenAIRE

    Messing, R. O.; Carpenter, C. L.; Diamond, I.; Greenberg, D A

    1986-01-01

    The acute and long-term effects of ethanol on voltage-dependent Ca channel function were studied in PC12, a clonal cell line of neural crest origin. Acute exposure to ethanol produced a concentration-dependent decrease in depolarization-evoked 45Ca2+ uptake, while prolonged (2-10 days) exposure led to a reciprocal increase in 45Ca2+ uptake and in the number of Ca-channel binding sites labeled by the dihydropyridine Ca-channel antagonist [3H]nitrendipine. Uptake was restored to control levels ...

  6. A Method for Determination of in Run-Up Front Velocities on Dikes in Oblique and Short-Crested Waves

    DEFF Research Database (Denmark)

    Andersen, Thomas Lykke; Nørgaard, Jørgen Harck; Burcharth, Hans F.

    2011-01-01

    flow directions on a dike. A validation of the proposed method is made against existing semiempirical formulae and measurements from a micro-propeller in case of perpendicular long-crested waves. Moreover, the method is applied for long- and short-crested oblique waves where results show that the...

  7. Blunt cardiac rupture.

    Science.gov (United States)

    Martin, T D; Flynn, T C; Rowlands, B J; Ward, R E; Fischer, R P

    1984-04-01

    Blunt injury to the heart ranges from contusion to disruption. This report comprises 14 patients seen during a 6-year period with cardiac rupture secondary to blunt trauma. Eight patients were injured in automobile accidents, two patients were injured in auto-pedestrian accidents, two were kicked in the chest by ungulates, and two sustained falls. Cardiac tamponade was suspected in ten patients. Five patients presented with prehospital cardiac arrest or arrested shortly after arrival. All underwent emergency department thoracotomy without survival. Two patients expired in the operating room during attempted cardiac repair; both had significant extracardiac injury. Seven patients survived, three had right atrial injuries, three had right ventricular injuries, and one had a left atrial injury. Cardiopulmonary bypass was not required for repair of the surviving patients. There were no significant complications from the cardiac repair. The history of significant force dispersed over a relatively small area of the precordium as in a kicking injury from an animal or steering wheel impact should alert the physician to possible cardiac rupture. Cardiac rupture should be considered in patients who present with signs of cardiac tamponade or persistent thoracic bleeding after blunt trauma. PMID:6708151

  8. Neural Engineering

    Science.gov (United States)

    He, Bin

    About the Series: Bioelectric Engineering presents state-of-the-art discussions on modern biomedical engineering with respect to applications of electrical engineering and information technology in biomedicine. This focus affirms Springer's commitment to publishing important reviews of the broadest interest to biomedical engineers, bioengineers, and their colleagues in affiliated disciplines. Recent volumes have covered modeling and imaging of bioelectric activity, neural engineering, biosignal processing, bionanotechnology, among other topics.

  9. Neural networks

    Czech Academy of Sciences Publication Activity Database

    Vajda, Igor; Grim, Jiří

    Oxford : Eolss Publishers-UNESCO, 2008 - (Parra-Luna, F.), s. 224-248 ISBN 978-1-84826-654-4. - (Encyclopedia of Life Support Systems. Volume III) R&D Projects: GA ČR GA102/07/1594 Institutional research plan: CEZ:AV0Z10750506 Keywords : neural networks * probabilistic approach Subject RIV: BD - Theory of Information http://library.utia.cas.cz/separaty/2008/SI/vajda-systems science and cybernetics .pdf

  10. 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 ...

  11. Mathematical cardiac electrophysiology

    CERN Document Server

    Colli Franzone, Piero; Scacchi, Simone

    2014-01-01

    This book covers the main mathematical and numerical models in computational electrocardiology, ranging from microscopic membrane models of cardiac ionic channels to macroscopic bidomain, monodomain, eikonal models and cardiac source representations. These advanced multiscale and nonlinear models describe the cardiac bioelectrical activity from the cell level to the body surface and are employed in both the direct and inverse problems of electrocardiology. The book also covers advanced numerical techniques needed to efficiently carry out large-scale cardiac simulations, including time and space discretizations, decoupling and operator splitting techniques, parallel finite element solvers. These techniques are employed in 3D cardiac simulations illustrating the excitation mechanisms, the anisotropic effects on excitation and repolarization wavefronts, the morphology of electrograms in normal and pathological tissue and some reentry phenomena. The overall aim of the book is to present rigorously the mathematica...

  12. CSUB CREST Research on Climate Change and the San Joaquin Valley, CA

    Science.gov (United States)

    Krugh, W. C.; Negrini, R. M.; Baron, D.; Gillespie, J.; Horton, R. A.; Montoya, E.; Cruz-Boone, C.; Andrews, G. D.; Guo, J.

    2015-12-01

    As part of the NSF-supported Centers for Excellence in Science and Technology (CREST), student and faculty researchers at California State University, Bakersfield (CSUB) have been investigating the regional impacts of climate change as well as evaluating the potential of local contributions to its abatement. Highlights of this research include; 1) the development of a high-resolution climate record from Tulare Lake sediments that spans the past 20,000 years, 2) the quantitative analysis and prediction of climate change impacts on Sierra Nevada snowpack, 3) the detailed subsurface characterization of San Joaquin Valley oilfields targeted for CO2 sequestration, and 4) the evaluation of proposed host rock suitability under simulated CO2 injection conditions. To date, CSUB CREST supported research has resulted in 26 contributions to peer-reviewed journals (currently published or in-review). A primary goal of CSUB CREST is to improve the recruitment, retention, and success of students from the local community, the majority of whom are from backgrounds under-represented in STEM disciplines. More than 28 students have been directly involved in the basic and applied research projects supported by this program. The majority of these students have received, or are on track to receive, an M.S. degree and have ultimately gained employment in a STEM field or been accepted into a Ph.D. program. This presentation, and others in this session, will focus on the accomplishments, challenges, and strategies for success gleaned from CSUB CREST Phase 1.

  13. Nesting habitat requirements and nestling diet in the Mediterranean populations of Crested Tits Lophophanes cristatus

    NARCIS (Netherlands)

    Atienzar, F.; Barba, E.; Holleman, L.J.M.; Belda, E.J.

    2009-01-01

    Most bird species show specific habitat requirements for breeding and feeding. We studied the pattern of habitat occupation, nestling diet and breeding performance of Crested Tits Lophophanes cristatus in a “typical” (coniferous) and an “atypical” (Holm Oak Quercus ilex) forest in eastern Spain duri

  14. 78 FR 25263 - Eagle Mountain Pumped Storage Hydroelectric Project; Eagle Crest Energy; Notice of Meeting With...

    Science.gov (United States)

    2013-04-30

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Eagle Mountain Pumped Storage Hydroelectric Project; Eagle Crest Energy... Power Act), on the Eagle Mountain Pumped Storage Hydroelectric Project. e. All local, state, and...

  15. 76 FR 15971 - Eagle Mountain Pumped Storage Hydroelectric Project; Eagle Crest Energy; Notice of Teleconference

    Science.gov (United States)

    2011-03-22

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Eagle Mountain Pumped Storage Hydroelectric Project; Eagle Crest Energy; Notice of Teleconference a. Date and Time of Meeting: Friday, April 15, 2011 at 9 a.m. (Pacific Time)....

  16. 76 FR 22699 - Eagle Mountain Pumped Storage Hydroelectric Project, Eagle Crest Energy; Notice of Teleconference

    Science.gov (United States)

    2011-04-22

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Eagle Mountain Pumped Storage Hydroelectric Project, Eagle Crest Energy; Notice of Teleconference a. Date and Time of Meeting: Friday, May 6, 2011 at 1 p.m. (Pacific Time)....

  17. 76 FR 69225 - Migratory Bird Permits; Double-Crested Cormorant Management in the United States

    Science.gov (United States)

    2011-11-08

    ....) and other Federal laws, while enabling management of human-wildlife conflicts related to the expansion.... Double-crested cormorants have been implicated in several human-DCCO conflict issues including... conflicts. Permits are still used to resolve conflicts related to human health and safety and...

  18. Calibration of reaction rates for the CREST reactive-burn model

    Science.gov (United States)

    Handley, Caroline

    2015-06-01

    In recent years, the hydrocode-based CREST reactive-burn model has had success in modelling a range of shock initiation and detonation propagation phenomena in polymer bonded explosives. CREST uses empirical reaction rates that depend on a function of the entropy of the non-reacted explosive, allowing the effects of initial temperature, porosity and double-shock desensitisation to be simulated without any modifications to the model. Until now, the sixteen reaction-rate coefficients have been manually calibrated by trial and error, using hydrocode simulations of a subset of sustained-shock initiation gas-gun experiments and the detonation size-effect curve for the explosive. This paper will describe the initial development of an automatic method for calibrating CREST reaction-rate coefficients, using the well-established Particle Swarm Optimisation (PSO) technique. The automatic method submits multiple hydrocode simulations for each ``particle'' and analyses the results to determine the ``misfit'' to gas-gun and size-effect data. Over ~40 ``generations,'' the PSO code finds a best set of reaction-rate coefficients that minimises the misfit. The method will be demonstrated by developing a new CREST model for EDC32, a conventional high explosive.

  19. Management of Vascular Risk Factors in the Carotid Revascularization Endarterectomy Versus Stenting Trial (CREST)

    OpenAIRE

    Meschia, James F; Voeks, Jenifer H.; Leimgruber, Pierre P.; Mantese, Vito A.; Timaran, Carlos H; Chiu, David; Bart M. Demaerschalk; Howard, Virginia J; Hughes, Susan E.; Longbottom, Mary; Howard, Annie Green; Brott, Thomas G

    2014-01-01

    Background The Carotid Revascularization Endarterectomy Versus Stenting Trial (CREST) is a multicenter randomized trial of stenting versus endarterectomy in patients with symptomatic and asymptomatic carotid disease. This study assesses management of vascular risk factors. Methods and Results Management was provided by the patient's physician, with biannual monitoring results collected by the local site. Therapeutic targets were low‐density lipoprotein, cholesterol

  20. [Cardiac evaluation before non-cardiac surgery].

    Science.gov (United States)

    Menzenbach, Jan; Boehm, Olaf

    2016-07-01

    Before non-cardiac surgery, evaluation of cardiac function is no frequent part of surgical treatment. European societies of anesthesiology and cardiology published consensus-guidelines in 2014 to present a reasonable approach for preoperative evaluation. This paper intends to differentiate the composite of perioperative risk and to display the guidelines methodical approach to handle it. Features to identify patients at risk from an ageing population with comorbidities, are the classification of surgical risk, functional capacity and risk indices. Application of diagnostic means, should be used adjusted to this risk estimation. Cardiac biomarkers are useful to discover risk of complications or mortality, that cannot be assessed by clinical signs. After preoperative optimization and perioperative cardiac protection, the observation of the postoperative period remains, to prohibit complications or even death. In consideration of limited resources of intensive care department, postoperative ward rounds beyond intensive care units are considered to be an appropriate instrument to avoid or recognize complications early to reduce postoperative mortality. PMID:27479258

  1. Novel structural components of the ventral disc and lateral crest in Giardia intestinalis.

    Directory of Open Access Journals (Sweden)

    Kari D Hagen

    2011-12-01

    Full Text Available Giardia intestinalis is a ubiquitous parasitic protist that is the causative agent of giardiasis, one of the most common protozoan diarrheal diseases in the world. Giardia trophozoites attach to the intestinal epithelium using a specialized and elaborate microtubule structure, the ventral disc. Surrounding the ventral disc is a less characterized putatively contractile structure, the lateral crest, which forms a continuous perimeter seal with the substrate. A better understanding of ventral disc and lateral crest structure, conformational dynamics, and biogenesis is critical for understanding the mechanism of giardial attachment to the host. To determine the components comprising the ventral disc and lateral crest, we used shotgun proteomics to identify proteins in a preparation of isolated ventral discs. Candidate disc-associated proteins, or DAPs, were GFP-tagged using a ligation-independent high-throughput cloning method. Based on disc localization, we identified eighteen novel DAPs, which more than doubles the number of known disc-associated proteins. Ten of the novel DAPs are associated with the lateral crest or outer edge of the disc, and are the first confirmed components of this structure. Using Fluorescence Recovery After Photobleaching (FRAP with representative novel DAP::GFP strains we found that the newly identified DAPs tested did not recover after photobleaching and are therefore structural components of the ventral disc or lateral crest. Functional analyses of the novel DAPs will be central toward understanding the mechanism of ventral disc-mediated attachment and the mechanism of disc biogenesis during cell division. Since attachment of Giardia to the intestine via the ventral disc is essential for pathogenesis, it is possible that some proteins comprising the disc could be potential drug targets if their loss or disruption interfered with disc biogenesis or function, preventing attachment.

  2. A pilot study investigating the utilization of crest pads for treatment of toe callus and ulceration.

    Science.gov (United States)

    Melo, Monica; Bernecker, Tricia; McCullough, James; Hong, John; Trumbauer, Jane Scott; Miller, Mary Ellen

    2015-12-01

    Patients with lesser-toe deformities are at increased risk of developing calluses and ulcers on the distal ends of the affected digits because of the increased pressures applied to these areas. The number of diabetic patients in the United States continues to increase, along with associated comorbidities such as peripheral vascular disease and peripheral neuropathy. These conditions predispose patients to developing foot ulcerations, especially if foot deformities are present. Crest pads are a simple-to-make, inexpensive option to treat calluses and ulcerations on the distal ends of digits; however, there is no research available that support their use. Crest pads consist of rolled gauze covered in moleskin, with a large opening that fits over several toes and lies on the dorsal aspect of the foot, with the padded portion resting under the toes. Over several days of use, the pad molds to the plantar aspect of the toes, offloading pressure from the distal end of the affected digit(s). The sample was obtained through a retrospective chart review of patients identified as having had at least one nail care visit and at least one follow-up visit at a vascular surgery practice between August 2011 and December 2014. Potential subjects with toe deformities who presented with callus or ulcer on the distal end of a digit were considered for inclusion, if they received a crest pad as part of their treatment plan. The scholarly project was a preintervention or postintervention design with subjects acting as their own controls. McNemar's test was used to analyze the results which were statistically significant (P < .0001 at first callus follow-up and P = .0002 at second callus follow-up) for callus, hemorrhagic callus, and/or ulcer improvement following the crest pad intervention. The results of this scholarly project support the use of crest pads in patients with lesser-toe deformities to treat distal toe calluses and/or ulcerations. PMID:26567055

  3. Cardiac metabolism and arrhythmias

    OpenAIRE

    Barth, Andreas S.; Tomaselli, Gordon F.

    2009-01-01

    Sudden cardiac death remains a leading cause of mortality in the Western world, accounting for up to 20% of all deaths in the U.S.1, 2 The major causes of sudden cardiac death in adults age 35 and older are coronary artery disease (70–80%) and dilated cardiomyopathy (10–15%).3 At the molecular level, a wide variety of mechanisms contribute to arrhythmias that cause sudden cardiac death, ranging from genetic predisposition (rare mutations and common polymorphisms in ion channels and structural...

  4. [Cardiac Rehabilitation 2015].

    Science.gov (United States)

    Hoffmann, Andreas

    2015-11-25

    The goals of cardiac rehabilitation are (re-)conditioning and secondary prevention in patients with heart disease or an elevated cardiovascular risk profile. Rehabilitation is based on motivation through education, on adapted physical activity, instruction of relaxation techniques, psychological support and optimized medication. It is performed preferably in groups either in outpatient or inpatient settings. The Swiss working group on cardiac rehabilitation provides a network of institutions with regular quality auditing. Positive effects of rehabilitation programs on mortality and morbidity have been established by numerous studies. Although a majority of patients after cardiac surgery are being referred to rehabilitation, these services are notoriously underused after catheter procedures. PMID:26602848

  5. Comprehensive cardiac rehabilitation

    DEFF Research Database (Denmark)

    Kruse, Marie; Hochstrasser, Stefan; Zwisler, Ann-Dorthe O;

    2006-01-01

    OBJECTIVES: The costs of comprehensive cardiac rehabilitation are established and compared to the corresponding costs of usual care. The effect on health-related quality of life is analyzed. METHODS: An unprecedented and very detailed cost assessment was carried out, as no guidelines existed for...... uncertain and may be as high as euro 1.877. CONCLUSIONS: Comprehensive cardiac rehabilitation is more costly than usual care, and the higher costs are not outweighed by a quality of life gain. Comprehensive cardiac rehabilitation is, therefore, not cost-effective....

  6. Molecular Basis of Cardiac Myxomas

    Directory of Open Access Journals (Sweden)

    Pooja Singhal

    2014-01-01

    Full Text Available Cardiac tumors are rare, and of these, primary cardiac tumors are even rarer. Metastatic cardiac tumors are about 100 times more common than the primary tumors. About 90% of primary cardiac tumors are benign, and of these the most common are cardiac myxomas. Approximately 12% of primary cardiac tumors are completely asymptomatic while others present with one or more signs and symptoms of the classical triad of hemodynamic changes due to intracardiac obstruction, embolism and nonspecific constitutional symptoms. Echocardiography is highly sensitive and specific in detecting cardiac tumors. Other helpful investigations are chest X-rays, magnetic resonance imaging and computerized tomography scan. Surgical excision is the treatment of choice for primary cardiac tumors and is usually associated with a good prognosis. This review article will focus on the general features of benign cardiac tumors with an emphasis on cardiac myxomas and their molecular basis.

  7. Automatic Implantable Cardiac Defibrillator

    Medline Plus

    Full Text Available Automatic Implantable Cardiac Defibrillator February 19, 2009 Halifax Health Medical Center, Daytona Beach, FL Welcome to Halifax Health Daytona Beach, Florida. Over the next hour you' ...

  8. Sudden Cardiac Arrest

    Science.gov (United States)

    ... scan, or MUGA, which shows how well your heart is pumping blood. Magnetic resonance imaging (MRI) which gives doctors detailed pictures of your heart. How is SCA treated? Sudden cardiac arrest should ...

  9. Sudden Cardiac Arrest

    Science.gov (United States)

    ... Heart Risk Factors & Prevention Heart Diseases & Disorders Atrial Fibrillation (AFib) Sudden Cardiac Arrest (SCA) SCA: Who's At Risk? Prevention of SCA What Causes SCA? SCA Awareness Atrial Flutter Heart Block Heart Failure Sick Sinus Syndrome Substances & Heart Rhythm Disorders Symptoms & ...

  10. Sudden cardiac death

    Directory of Open Access Journals (Sweden)

    Aranđelović Aleksandra Č.

    2004-01-01

    Full Text Available Sudden cardiac death in an athlete is rare and tragic event. An athlete's death draws high public attention given that athletes are considered the healthiest category of society. The vast majority of sudden cardiac death in young athletes is due to congenital cardiac malformations such as hypertrophie cardiomyopathy and various coronary artery anomalies. In athletes over age 35, the usual cause of sudden cardiac death is coronary artery disease. With each tragic death of a young athlete, there is a question why this tragedy has not been prevented. The American College of Sports Medicine and the American Heart Association recommend that a pre-participation exam should include a complete cardiovascular history and physical examination.

  11. Cardiac Risk Assessment

    Science.gov (United States)

    ... to assess cardiac risk include: High-sensitivity C-reactive protein (hs-CRP) : Studies have shown that measuring ... LDL-C but does not respond to typical strategies to lower LDL-C such as diet, exercise, ...

  12. Cardiac arrest - cardiopulmonary resuscitation

    Institute of Scientific and Technical Information of China (English)

    Basri Lenjani; Besnik Elshani; Nehat Baftiu; Kelmend Pallaska; Kadir Hyseni; Njazi Gashi; Nexhbedin Karemani; Ilaz Bunjaku; Taxhidin Zaimi; Arianit Jakupi

    2014-01-01

    Objective:To investigate application of cardiopulmonary resuscitation(CPR) measures within the golden minutes inEurope.Methods:The material was taken from theUniversityClinical Center ofKosovo -EmergencyCentre inPristina, during the two(2) year period(2010-2011).The collected date belong to the patients with cardiac arrest have been recorded in the patients' log book protocol at the emergency clinic.Results:During the2010 to2011 in the emergency center of theCUCK inPristina have been treated a total of269 patients with cardiac arrest, of whom159 or59.1% have been treated in2010, and110 patients or40.9% in2011.Of the269 patients treated in the emergency centre,93 or34.6% have exited lethally in the emergency centre, and176 or 65.4% have been transferred to other clinics.In the total number of patients with cardiac arrest, males have dominated with186 cases, or69.1%.The average age of patients included in the survey was56.7 year oldSD±16.0 years.Of the269 patients with cardiac arrest, defibrillation has been applied for93 or34.6% of patients.In the outpatient settings defibrillation has been applied for3 or3.2% of patients.Patients were defibrillated with application of one to four shocks. Of27 cases with who have survived cardiac arrest, none of them have suffered cardiac arrest at home,3 or11.1% of them have suffered cardiac arrest on the street, and24 or88.9% of them have suffered cardiac arrest in the hospital.5 out of27 patients survived have ended with neurological impairment.Cardiac arrest cases were present during all days of the week, but frequently most reported cases have been onMonday with32.0% of cases, and onFriday with24.5% of cases. Conclusions:All survivors from cardiac arrest have received appropriate medical assistance within10 min from attack, which implies that if cardiac arrest occurs near an institution health care(with an opportunity to provide the emergent health care) the rate of survival is higher.

  13. Awareness in cardiac anesthesia.

    LENUS (Irish Health Repository)

    Serfontein, Leon

    2010-02-01

    Cardiac surgery represents a sub-group of patients at significantly increased risk of intraoperative awareness. Relatively few recent publications have targeted the topic of awareness in this group. The aim of this review is to identify areas of awareness research that may equally be extrapolated to cardiac anesthesia in the attempt to increase understanding of the nature and significance of this scenario and how to reduce it.

  14. Safety in cardiac surgery

    OpenAIRE

    Siregar, S.

    2013-01-01

    The monitoring of safety in cardiac surgery is a complex process, which involves many clinical, practical, methodological and statistical issues. The objective of this thesis was to measure and to compare safety in cardiac surgery in The Netherlands using the Netherlands Association for Cardio-Thoracic Surgery (NVT) database. The safety of care is usually measured using patient outcomes. If outcomes are not available, the process and structure of care may be used. Outcomes should be adjusted ...

  15. Cardiac rehabilitation in Germany.

    Science.gov (United States)

    Karoff, Marthin; Held, Klaus; Bjarnason-Wehrens, Birna

    2007-02-01

    The purpose of this review is to give an overview of the rehabilitation measures provided for cardiac patients in Germany and to outline its legal basis and outcomes. In Germany the cardiac rehabilitation system is different from rehabilitation measures in other European countries. Cardiac rehabilitation in Germany since 1885 is based on specific laws and the regulations of insurance providers. Cardiac rehabilitation has predominantly been offered as an inpatient service, but has recently been complemented by outpatient services. A general agreement on the different indications for offering these two services has yet to be reached. Cardiac rehabilitation is mainly offered after an acute cardiac event and bypass surgery. It is also indicated in severe heart failure and special cases of percutaneous coronary intervention. Most patients are men (>65%) and the age at which events occur is increasing. The benefits obtained during the 3-4 weeks after an acute event, and confirmed in numerous studies, are often later lost under 'usual care' conditions. Many attempts have been made by rehabilitation institutions to improve this deficit by providing intensive aftercare. One instrument set up to achieve this is the nationwide institution currently comprising more than 6000 heart groups with approximately 120000 outpatients. After coronary artery bypass grafting or acute coronary syndrome cardiac rehabilitation can usually be started within 10 days. The multidisciplinary rehabilitation team consists of cardiologists, psychologists, exercise therapists, social workers, nutritionists and nurses. The positive effects of cardiac rehabilitation are also important economically, for example, for the improvement of secondary prevention and vocational integration. PMID:17301623

  16. Ranolazine in Cardiac Arrhythmia.

    Science.gov (United States)

    Saad, Marwan; Mahmoud, Ahmed; Elgendy, Islam Y; Richard Conti, C

    2016-03-01

    Ranolazine utilization in the management of refractory angina has been established by multiple randomized clinical studies. However, there is growing evidence showing an evolving role in the field of cardiac arrhythmias. Multiple experimental and clinical studies have evaluated the role of ranolazine in prevention and management of atrial fibrillation, with ongoing studies on its role in ventricular arrhythmias. In this review, we will discuss the pharmacological, experimental, and clinical evidence behind ranolazine use in the management of various cardiac arrhythmias. PMID:26459200

  17. Cardiac tumours in infancy

    OpenAIRE

    Yadava, O.P.

    2012-01-01

    Cardiac tumours in infancy are rare and are mostly benign with rhabdomyomas, fibromas and teratomas accounting for the majority. The presentation depends on size and location of the mass as they tend to cause cavity obstruction or arrhythmias. Most rhabdomyomas tend to regress spontaneously but fibromas and teratomas generally require surgical intervention for severe haemodynamic or arrhythmic complications. Other relatively rare cardiac tumours too are discussed along with an Indian perspect...

  18. Cardiac Image Registration

    Directory of Open Access Journals (Sweden)

    2008-09-01

    Full Text Available Long procedure time and somewhat suboptimal results hinder the widespread use of catheter ablation of complex arrhythmias such as atrial fibrillation (AF. Due to lack of contrast differentiation between the area of interest and surrounding structures in a moving organ like heart, there is a lack of proper intraprocedural guidance using current imaging techniques for ablation. Cardiac image registration is currently under investigation and is in clinical use for AF ablation. Cardiac image registration, which involves integration of two images in the context of left atrium (LA, is intermodal, with the acquired image and the real-time reference image residing in different image spaces, and involves optimization, where one image space is transformed into the other. Unlike rigid body registration, cardiac image registration is unique and challenging due to cardiac motion during the cardiac cycle and due to respiration. This review addresses the basic principles of the emerging technique of registration and the inherent limitations as they relate to cardiac imaging and registration.

  19. Cardiac Image Registration

    Directory of Open Access Journals (Sweden)

    Jasbir Sra

    2008-09-01

    Full Text Available Long procedure time and somewhat suboptimal results hinder the widespread use of catheter ablation of complex arrhythmias such as atrial fibrillation (AF. Due to lack of contrast differentiation between the area of interest and surrounding structures in a moving organ like heart, there is a lack of proper intraprocedural guidance using current imaging techniques for ablation. Cardiac image registration is currently under investigation and is in clinical use for AF ablation. Cardiac image registration, which involves integration of two images in the context of the left atrium (LA, is intermodal, with the acquired image and the real-time reference image residing in different image spaces, and involves optimization, where one image space is transformed into the other. Unlike rigid body registration, cardiac image registration is unique and challenging due to cardiac motion during the cardiac cycle and due to respiration. This review addresses the basic principles of the emerging technique of registration and the inherent limitations as they relate to cardiac imaging and registration.

  20. Postoperative cardiac arrest due to cardiac surgery complications

    International Nuclear Information System (INIS)

    To examine the role of anesthetists in the management of cardiac arrest occurring in association with cardiac anesthesia. In this retrospective study we studied the potential performances for each of the relevant incidents among 712 patients undergoing cardiac operations at Golestan and Naft Hospitals Ahwaz between November 2006 and July 2008. Out of total 712 patients undergoing cardiac surgery, cardiac arrest occurred in 28 cases (3.9%) due to different postoperative complications. This included massive bleeding (50% of cardiac arrest cases, 1.9% of patients); pulseless supra ventricular tachycardia (28.5% of cardiac arrest cases, 1.1% of patients); Heart Failure (7% of cardiac arrest cases, 0.2% of patients); Aorta Arc Rapture (3.5% of cardiac arrest cases, 0.1% of patients); Tamponade due to pericardial effusion (3.5% of cardiac arrest cases, 0.1% of total patients); Right Atrium Rupture (3.5% of cardiac arrest cases, 0.1% of patients) were detected after cardiac surgery. Out of 28 cases 7 deaths occurred (25% of cardiac arrest cases, 0.1% of patients). The most prevalent reason for cardiac arrest during post operative phase was massive bleeding (50%) followed by pulseless supra ventricular tachycardia (28.5%). Six patients had some morbidity and the remaining 15 patients recovered. There are often multiple contributing factors to a cardiac arrest under cardiac anesthesia, as much a complete systematic assessment of the patient, equipment, and drugs should be completed. We also found that the diagnosis and management of cardiac arrest in association with cardiac anesthesia differs considerably from that encountered elsewhere. (author)

  1. CREST Syndrome - a Limited Form of Systemic Scleroderma: a Case Report and Literature Review

    Directory of Open Access Journals (Sweden)

    Paravina Mirjana

    2015-09-01

    Full Text Available Systemic scleroderma (SSc is a multisystem disease with microvascular abnormalities, autoimmune disorders, excessive collagen production and deposition, and fibrosis of the skin and internal organs. According to the simplest, though incomplete classification, there are two forms of SSc: diffuse and limited (formerly acrosclerosis. CREST syndrome is a subtype of limited SSc, characterized by: calcinosis, Raynaud’s phenomenon, esophageal dysfunction, sclerodactyly, and telangiectasia. We present a patient with all the features of the CREST syndrome, which appeared at the age of 43 and lasted for 23 years. The patient presented with a gradual development of symptoms during the first ten years, from Raynaud’s phenomenon, skin sclerosis, calcinosis, telangiectasia, and esophageal dysmotility. The diagnosis was based on clinical findings and relevant diagnostic procedures. The article presents a literature review on the epidemiology, etiology, pathophysiology, clinical manifestations, various attempts at classification, diagnostic criteria, and therapeutic modalities.

  2. Linear surface capillary-gravity short-crested waves on a current

    Institute of Scientific and Technical Information of China (English)

    HUANG Hu

    2008-01-01

    One of the forward situations in the study of water waves is the basic three-dimensional surface wave motion of short-crested waves. Capillary waves result in rich effects concerned closely with remote sensing in the open ocean. Ocean currents experience a complete process in surface wave motion. Based on the above ideas, a linear dynamical system of surface capillary-gravity short-crested waves is developed by considering the current effects, thus leading to the following analytical expressions of the kinematic and dynamic variables: the wave height, the wave steepness, the phase velocity, the wave-particle velocities, accelerations and trajectories and the wave pressure. A number of the classi-cal, typical and latest special wave cases can arise from these expressions.

  3. Possible rim crest deposits in cores 12027 and 15008 - Some interpretations and problems for future research

    Science.gov (United States)

    Nagle, J. S.

    1980-01-01

    Light colored coarse grained soils in the upper parts of cores 12027 and 15008 have a chaotic fabric and abundant bedrock-derived rock fragments. They overlie dark colored, fine grained soils with horizontal fabric and abundant regolith-derived rock fragments. The light colored soils are interpreted to be rim crest deposits associated with the craters seen in the lunar surface sampling photographs. The coarse size, poor sorting and chaotic fabric are believed to have originated by the violent mixing processes which are expected with ejecta deposition. The increase in bedrock-derived particles within the light colored soil can be explained by ejecta from craters that penetrated through or deep into the regolith. The dark soils are believed to predate the craters. Distribution of rock fragments in the material interpreted as rim crest ejecta does not fit a simple model of overturned stratigraphy.

  4. Implant-Prosthetic Rehabilitation in Bilateral Agenesis of Maxillary Lateral Incisors with a Mini Split Crest

    Science.gov (United States)

    Figliuzzi, M. M.; Giudice, A.; Pileggi, S.; Pacifico, D.; Marrelli, M.; Tatullo, M.; Fortunato, L.

    2016-01-01

    The reported clinical case describes the surgical procedure of ridge augmentation by using a “split crest” technique with a partial thickness flap and a subsequent implant-prosthetic rehabilitation aimed at treating a bilateral agenesis of the upper lateral incisors. In such cases with vestibule-palatal and mesial-distal scarce bone thicknesses associated with the need of a proper functional and aesthetic rehabilitation, the split crest technique is particularly suitable. In the case we reported, because of the poor bone thicknesses, we performed a minimally invasive split crest which allowed a correct insertion of the fixtures. This technique allowed us to achieve an optimal functional and aesthetic rehabilitation; moreover, we obtained a good emergency profile, ensuring the vitality of the close teeth and ensuring a good primary stability and the following osseointegration of dental implants. PMID:27190658

  5. Disproportionately severe calcinosis cutis in an 88-year-old patient with CREST syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Buchowski, J.M.; Ahn, N.U.; Ahn, U.M. [Dept. of Orthopaedic Surgery, Johns Hopkins Univ. School of Medicine, Baltimore, MD (United States); McCarthy, E.F. [Dept. of Orthopaedic Surgery, Johns Hopkins Univ. School of Medicine, Baltimore, MD (United States); Dept. of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD (United States); Mehta, M.B. [Clinical Associates, Good Samaritan Hospital, Baltimore, MD (United States)

    2001-08-01

    An 88-year-old woman with CREST syndrome (calcinosis, Raynaud's phenomenon, esophageal dysmotility, sclerodactyly, and telangiectasias) presented with hyperglycemia, intravascular depletion, and atrial fibrillation. The patient was found to have unusually severe calcinosis cutis in both legs extending from the knees to the ankles bilaterally, as well as Raynaud's phenomenon, sclerodactyly, and telangiectasias. The patient was normocalcemic and normophosphatemic. Although subcutaneous calcification is often seen with CREST syndrome, this case is unusual in that the area of involvement was much larger than previously described. Furthermore, the amount of calcinosis was disproportionately severe and was the major cause of symptoms and disability compared with the other components of the syndrome. (orig.)

  6. Habitat use and food selection of small mammals near a sagebrush/crested wheatgrass interface in southeastern Idaho

    International Nuclear Information System (INIS)

    Research has been conducted on various aspects of the ecology of wildlife residing on and adjacent to the Subsurface Disposal Area (SDA) and one other low-level radioactive waste disposal site on the Idaho National Engineering Laboratory (INEL) in southeastern Idaho. Habitat use and food selection data were collected for deer mice (Peromyscus maniculatus), montane voles (Microtus montanus), Ord's kangaroo rats (Dipodomys ordii), and Townsend's ground squirrels (Spermophilus townsendii) near a sagebrush (Artemisia tridentata)/crested wheatgrass (Agropyron cristatum) interface. Significantly more captures occurred in the native sagebrush habitat than in areas planted in crested wheatgrass or in disturbed sites. Crested wheatgrass, a prolific seed producer, still accounted for over 30% of the total captures. Montane voles and Townsend's ground squirrels (during periods of aboveground activity) used the crested wheatgrass habitat throughout the summer, while deer mice and Ord's kangaroo rats exhibited heavy use after seed set

  7. ECOLOGY OF NON-BREEDING AND BREEDING CRESTED CARACARAS (CARACARA CHERIWAY) IN FLORIDA

    OpenAIRE

    Dwyer, James Fitzgerald

    2010-01-01

    Like many species, Floridaâ s population of Northern Crested Caracaras (Caracara cheriway, hereafter â caracaraâ ) is likely declining due to loss of breeding habitat. Consequently, management-oriented restrictions on landscape modification are applied where breeding occurs, but management rarely is extended beyond breeding areas. Focusing management on breeding areas can be effective if all caracaras occupy breeding areas, all breeding areas are detected, and no intermittent breeding oc...

  8. New Results from the NOAA CREST Lidar Network (CLN Observations in the US Eastcoast

    Directory of Open Access Journals (Sweden)

    Moshary Fred

    2016-01-01

    Full Text Available This paper presents coordinated ground-based observations by the NOAA-CREST Lidar Network (CLN for profiling of aerosols, cloud, water vapor, and wind along the US east coast including Caribbean region at Puerto Rico. The instrumentation, methodology and observation capability are reviewed. The applications to continental and intercontinental-scale transport of smoke and dust plumes, and their large scale regional impact are discussed.

  9. Effect of X-ray beam vertical angulation on radiographic assessment of alveolar crest level.

    OpenAIRE

    Zulqarnain B; Almas K

    1998-01-01

    Periodontal diseases are diagnosed and monitored by various methods. Probing pocket depth measurements and dental radiographs are two of the most commonly used methods. The aim of this study was to assess the effect of x-ray beam vertical angulation on radiographic assessment of alveolar crest level in five human mandibles. A standardized technique was used to take bitewing radiographs with -10 degrees, 0 degree and +10 degrees angulation of X-Ray beam. The range of the mean difference...

  10. New Results from the NOAA CREST Lidar Network (CLN) Observations in the US Eastcoast

    Science.gov (United States)

    Moshary, Fred; Han, Zaw; Wu, Yonghua; Gross, Barry; Wesloh, Daniel; Hoff, Raymond M.; Delgado, Ruben; Su, Jia; Lei, Liqiao; Lee, Robert B.; McCormick, M. Pat; Diaz, Jesus; Cruz, Carlos; Parsiani, Hamed

    2016-06-01

    This paper presents coordinated ground-based observations by the NOAA-CREST Lidar Network (CLN) for profiling of aerosols, cloud, water vapor, and wind along the US east coast including Caribbean region at Puerto Rico. The instrumentation, methodology and observation capability are reviewed. The applications to continental and intercontinental-scale transport of smoke and dust plumes, and their large scale regional impact are discussed.

  11. Correlation of Cere Color with Intra- and Interspecific Agonistic Interactions of Crested Caracaras

    OpenAIRE

    Dwyer, James F.

    2014-01-01

    Bright coloration in birds is an important indicator of individual quality often used in social displays. Structural, carotenoid-, and melanin-based colors are long-lasting, widespread, and widely studied. Hemoglobin-based colors are ephemeral, rare, and less studied. Hemoglobin-based displays occur when an individual facultatively enhances or restricts blood flow through caruncles, combs, wattles, or other highly vascularized un-feathered skin patches. In Crested Caracaras (Caracara cheriway...

  12. Perforated sigmoid diverticulitis in a lumbar hernia after iliac crest bone graft - a case report

    OpenAIRE

    Frueh, Florian S; Vuille-Dit-Bille, Raphael N; Raptis, Dimitri A; Notter, Hanspeter; Muff, Brigitte S

    2014-01-01

    Background The combination of perforated diverticulitis in a lumbar hernia constitutes an extremely rare condition. Case presentation We report a case of a 66 year old Caucasian woman presenting with perforated sigmoid diverticulitis localized in a lumbar hernia following iliac crest bone graft performed 18 years ago. Emergency treatment consisted of laparoscopic peritoneal lavage. Elective sigmoid resection was scheduled four months later. At the same time a laparoscopic hernia repair with a...

  13. Perforated sigmoid diverticulitis in a lumbar hernia after iliac crest bone graft - a case report

    OpenAIRE

    Frueh, Florian S; Vuille-Dit-Bille, Raphael N; Raptis, Dimitri A; Notter, Hanspeter; Muff, Brigitte S

    2014-01-01

    BACKGROUND The combination of perforated diverticulitis in a lumbar hernia constitutes an extremely rare condition. CASE PRESENTATION We report a case of a 66 year old Caucasian woman presenting with perforated sigmoid diverticulitis localized in a lumbar hernia following iliac crest bone graft performed 18 years ago. Emergency treatment consisted of laparoscopic peritoneal lavage. Elective sigmoid resection was scheduled four months later. At the same time a laparoscopic hernia rep...

  14. Estimation of Overtopping Rates on Slopes in Wave Power Devices and Other Low Crested Structures

    DEFF Research Database (Denmark)

    Kofoed, Jens Peter; Burcharth, Hans Falk

    Motivated by questions raised by developers of wave energy devices based on wave overtopping concepts, model tests have been performed to study overtopping of structures with limited draught, low crest freeboards and slope geometries designed to increase overtopping and thereby also the captured...... amount of wave energy. The test results have been incorporated in an existing overtopping prediction formula by application of correction factors presented in the paper...

  15. Population status of great crested newts (Triturus cristatus) at sites subjected to development mitigation

    OpenAIRE

    Lewis, Brett; Griffiths, Richard A.; John W. Wilkinson

    2016-01-01

    Increasing development of natural habitats frequently causes conflict with the conservation of protected species. Consequently, interventions that attempt to mitigate the impact of development are becoming increasingly commonplace. We used four approaches to assess the effectiveness of development mitigation on a species subject to widespread development pressures in Europe – the great crested newt (Triturus cristatus). Firstly, a systematic evidence review revealed eleven published studies o...

  16. A new crested pterosaur from the early cretaceous of Spain: the first European tapejarid (Pterodactyloidea: Azhdarchoidea)

    OpenAIRE

    Vullo, Romain; Marugán-Lobón, Jesús; Buscalioni, Angela D.; Gomez, Bernard; De La Fuente, Montserrat; Moratalla, José J.; Kellner, Alexander W. A.

    2012-01-01

    Background: The Tapejaridae is a group of unusual toothless pterosaurs characterized by bizarre cranial crests. From a paleoecological point of view, frugivorous feeding habits have often been suggested for one of its included clades, the Tapejarinae. So far, the presence of these intriguing flying reptiles has been unambiguously documented from Early Cretaceous sites in China and Brazil, where pterosaur fossils are less rare and fragmentary than in similarly-aged European strata. Methodology...

  17. The morphology of the sella turcica in velocardiofacial syndrome suggests involvement of a neural crest developmental field

    DEFF Research Database (Denmark)

    Mølsted, Kirsten; Boers, Maria; Kjaer, Inger

    2010-01-01

    measure the cranial base angles in individuals with VCFS and, if possible, to discover the developmental field that may be involved in the condition. The study included 33 patients with VCFS from the Copenhagen Cleft Palate Center, Denmark. The genotype was confirmed by fluorescence in situ hybridization...... aplasia, hypothyroidism, and posterior brain abnormality), suggest involvement of a specific developmental field....

  18. The lamprey: A jawless vertebrate model system for examining origin of the neural crest and other vertebrate traits

    OpenAIRE

    Green, Stephen A.; Bronner, Marianne E.

    2014-01-01

    Lampreys are a group of jawless fishes that serve as an important point of comparison for studies of vertebrate evolution. Lampreys and hagfishes are agnathan fishes, the cyclostomes, which sit at a crucial phylogenetic position as the only living sister group of the jawed vertebrates. Comparisons between cyclostomes and jawed vertebrates can help identify shared derived (i.e. synapomorphic) traits that might have been inherited from ancestral early vertebrates, if unlikely to have arisen con...

  19. EXTRACTION, QUANTIFICATION, AND MOLAR MASS DETERMINATION OF HYALURONIC ACID EXTRACTED FROM CHICKEN CREST

    Directory of Open Access Journals (Sweden)

    C. S. ROSA

    2008-11-01

    Full Text Available

    Hyaluronic acid (HA is part of the connective tissue. The polymer is composed of alternating units of ß-d-glucuronic acid and N-acetyl-ß-d-glucosamine linked, respectively, via 1-3 and 1-4 bonds. The chicken crest is one of the richest tissues in this polysaccharide. Since Brazil is one of the main chicken exporters in the world, the utilization of the crests of abated animals for the HA obtaining is particularly attractive. The present work sought to extract HA from chicken crest and to determine the molar mass of the extracted acid. Extraction was accomplished by proteolytic digestion with papain during 24 h at 60oC, followed by precipitation with cetylpyridinium chloride (CPC. Hexuronic acid content was determined via the carbazole method, the intrinsic viscosity was measured using the ball viscosimeter, and the molar mass was calculated by extrapolating the calibration line to zero. In addition, qualitative infrared spectroscopy was carried out on the sample using the Bomem MB spectrophotometer. The results show that the extraction method was effective: the extracted acid possesses a large molecular mass, and the extract contains a signifi cant amount of HA.

  20. Polyurethane resins derived from castor oil (Ricinus communis) for tibial crest deviation in dogs

    International Nuclear Information System (INIS)

    Medial patellar luxation is one of the most common orthopedic problems in small breeds of dogs and tibial crest deviation is a frequent accompaining anatomical abnormality. For that reason, the purpose of this study was to evaluate the behavior of castor oil derived polyurethane implants when apllied to experimental defects created on the medial side of the proximal tibia of normal puppies. Twelve dogs were randomly divided in 3 groups of 4 animals and were submitted to the same treatment. Histopathological study was performed respectively at 30 (GI), 60 (GII) and 90 (GIII) days post-surgery. Evaluations methods included clinical assessment, radiology, gross and macroscopic study, tomography and statistical analysis. Clinically, there were no signs of implant rejection. Radiology revealed intense periosteal reaction and new bone formation. On gross examination, there was thickening and lateral deviation of the tibial crest and new bone neoformation. On microscopic examination, there was fibrous tissue around the polyurethane, periosteal proliferation on the medial side of the tibia and no bone proliferation towards the implant. Cat scans reveled lateral deviation of the tibial crest in eleven animals, which was statistically significant (p<5; pared T test)

  1. Free iliac crest grafts with periosteum for treatment of old acetabular defects

    Institute of Scientific and Technical Information of China (English)

    ZHAO De-wei; SUN Qiang; WANG Ben-jie; CUI Da-ping

    2006-01-01

    Objective: To inquire into the therapeutic effectiveness of free iliac crest grafts with periosteum on old acetabular defects.Methods: From February 1996 to June 2005, 9 patients were treated with free iliac crest grafts with periosteum to reconstruct old acetabular defects. There were 7 males and 2 females and the average age was 41.3 years. The acetabular defects were caused by traffic accidents in 6 cases and fall injury in 3 cases. The time from injury to treatment was 4-13 months and averaged 8 months. Intraoperatively we firstly removed the acetabular fracture fragments of the posterior wall. The femoral head was then reducted. Bone graft was harvested from the iliac crest with periosteum, which was sculpted with a rongeur to conform to the defect. The concave (iliac fossa) side of the graft was placed toward the femoral head. The graft was securedly fixed by two to three leg screws.Results: Postoperative syndrome was not found in any of the cases. Harris' score system showed that the score raised from 32. 3 points preoperatively to 81 points postoperatively. The hip function was evaluated as excellent in 3 cases, good in 4 cases and fair in 2 cases.Conclusions: Although this procedure could not exactly reproduce the anatomy of the hip joint, it enables to restore the posterior stability, provide bone-stock for the hip joints and prevent dislocation of the femoral head.

  2. Use of the Vascularized Iliac-Crest Flap in Musculoskeletal Lesions

    Directory of Open Access Journals (Sweden)

    Cristiane Tonoli

    2013-01-01

    Full Text Available Bone loss was in the past treated by several methods, such as bone distraction and the use of nonvascularized or tissue-bank bone grafts. With the advent of modern microsurgical techniques, the vascularized bone flap has been used with good results; it resolves local nutritional problems, repairs soft tissue that is often damaged by severe trauma, and treats bone loss due to tumors, pseudarthroses, and osteomyelitis. This paper reports the authors’ experience with the use of vascularized iliac-crest flaps to treat orthopedic pathologies in five patients with traumatic bone loss (<10 cm, three with osteomyelitis, and three with atrophic nonunion. In all cases, the same surgeon obtained a vascularized iliac-crest flap with a pedicle based on the deep iliac circumflex artery. All flaps consolidated within a mean period of 3 months. These findings demonstrate that the use of an iliac-crest flap is a treatment option in cases of bone loss and that it is associated with good functional results and minimal donor-site morbidity.

  3. Experimental infection of crested caracara (Caracara plancus) with Toxoplasma gondii simulating natural conditions.

    Science.gov (United States)

    Vitaliano, S N; Mineo, T W P; André, M R; Machado, R Z; Mineo, J R; Werther, K

    2010-08-27

    Toxoplasma gondii affects mainly warm-blooded animals, including birds. Even though previous experimental data indicate that raptors are resistant to clinical infection, there is no information regarding the susceptibility of Brazilian birds of prey to T. gondii. The present study aimed to observe how the crested caracara, a common raptor in Brazil, interacts with T. gondii using an experimental model. Seven crested caracaras, seronegative for T. gondii, were separated into infected (n=5) and control groups (n=2). Birds from the infected group were fed T. gondii-infected Calomys callosus, a rodent present in Brazilian savanna and described as highly susceptible to infection by the parasite, for three consecutive days, while control animals were fed non-infected rodents. All infected birds produced T. gondii-specific IgG antibodies that were firstly detected at day 7 post-infection, with peak production detected between 15 and 30dpi. No significant alterations in clinical and hematological parameters were observed throughout the experimental period, and parasites were sparsely found in muscular tissues after the birds were euthanized. In conclusion, our results demonstrated that crested caracaras are resistant to oral infection with T. gondii, suggesting that the host-parasite relationship between both species has reached a remarkable equilibrium. PMID:20451327

  4. A NOVEL 3-D MODEL FOR THE WATER CRESTING IN HORIZONTAL WELLS

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    In the presence of bottom water, a drop in the reservoir pressure due to fluid production causes the aquifer water to expand and to flow into the reservoir. Therefore, hydrocarbon production from a well is limited by the critical flow rate. The main purpose of this study is to investigate the breakthrough time and the critical rate by using a novel 3-D horizontal well model. Based on the hypothesis that the horizontal well is located in any position of a circular reservoir with no-flow boundary on the top of the reservoir and constant pressure boundary at the bottom, the horizontal well has been regarded as an infinite conductivity line sink and then a 3-D steady-state flow model of the horizontal well is set up. A point sink pressure solution can be obtained with the Fourier transform. The result of the pressure distribution of the uniform flux horizontal well can be presented by means of the principle of superposition. According to the stable water cresting theory, this study confirms the stable height of water cresting and the critical rate. Meanwhile, it can re-confirm the breakthrough time at a specific rate. The output of a comparison between this 3-D model and the reservoir numerical simulator (Eclipse) shows the method presented here can be applied to investigate the behavior of a water cresting and to predict the breakthrough time at the bottom water driver reservoir.

  5. Cognitive Remediation and Emotion Skills Training (CREST) for anorexia nervosa in individual format: self-reported outcomes

    OpenAIRE

    Tchanturia, Kate; Doris, Eli; Mountford, Vicki; Fleming, Caroline

    2015-01-01

    Background To evaluate self-reported outcomes after a brief course of skills-based individual therapy for inpatients with anorexia nervosa (AN). Methods In this case series study 37 adults with AN participated in cognitive remediation and emotion skills training (CREST) sessions, and completed social anhedonia, alexithymia and motivational measures before and after the intervention. Results The CREST primary outcome measures were total scores on the Revised Social Anhedonia Scale (RSAS), whic...

  6. Spatial Ecology of the Critically Endangered Fijian Crested Iguana, Brachylophus vitiensis, in an Extremely Dense Population: Implications for Conservation

    OpenAIRE

    Morrison, Suzanne F.; Biciloa, Pita; Harlow, Peter S.; Keogh, J. Scott

    2013-01-01

    The Critically Endangered Fijian crested iguana, Brachylophus vitiensis, occurs at extreme density at only one location, with estimates of >10,000 iguanas living on the 70 hectare island of Yadua Taba in Fiji. We conducted a mark and recapture study over two wet seasons, investigating the spatial ecology and intraspecific interactions of the strictly arboreal Fijian crested iguana. This species exhibits moderate male-biased sexual size dimorphism, which has been linked in other lizard species...

  7. Yes-associated protein 65 (YAP expands neural progenitors and regulates Pax3 expression in the neural plate border zone.

    Directory of Open Access Journals (Sweden)

    Stephen T Gee

    Full Text Available Yes-associated protein 65 (YAP contains multiple protein-protein interaction domains and functions as both a transcriptional co-activator and as a scaffolding protein. Mouse embryos lacking YAP did not survive past embryonic day 8.5 and showed signs of defective yolk sac vasculogenesis, chorioallantoic fusion, and anterior-posterior (A-P axis elongation. Given that the YAP knockout mouse defects might be due in part to nutritional deficiencies, we sought to better characterize a role for YAP during early development using embryos that develop externally. YAP morpholino (MO-mediated loss-of-function in both frog and fish resulted in incomplete epiboly at gastrulation and impaired axis formation, similar to the mouse phenotype. In frog, germ layer specific genes were expressed, but they were temporally delayed. YAP MO-mediated partial knockdown in frog allowed a shortened axis to form. YAP gain-of-function in Xenopus expanded the progenitor populations in the neural plate (sox2(+ and neural plate border zone (pax3(+, while inhibiting the expression of later markers of tissues derived from the neural plate border zone (neural crest, pre-placodal ectoderm, hatching gland, as well as epidermis and somitic muscle. YAP directly regulates pax3 expression via association with TEAD1 (N-TEF at a highly conserved, previously undescribed, TEAD-binding site within the 5' regulatory region of pax3. Structure/function analyses revealed that the PDZ-binding motif of YAP contributes to the inhibition of epidermal and somitic muscle differentiation, but a complete, intact YAP protein is required for expansion of the neural plate and neural plate border zone progenitor pools. These results provide a thorough analysis of YAP mediated gene expression changes in loss- and gain-of-function experiments. Furthermore, this is the first report to use YAP structure-function analyzes to determine which portion of YAP is involved in specific gene expression changes and the

  8. Pediatric cardiac postoperative care

    Directory of Open Access Journals (Sweden)

    Auler Jr. José Otávio Costa

    2002-01-01

    Full Text Available The Heart Institute of the University of São Paulo, Medical School is a referral center for the treatment of congenital heart diseases of neonates and infants. In the recent years, the excellent surgical results obtained in our institution may be in part due to modern anesthetic care and to postoperative care based on well-structured protocols. The purpose of this article is to review unique aspects of neonate cardiovascular physiology, the impact of extracorporeal circulation on postoperative evolution, and the prescription for pharmacological support of acute cardiac dysfunction based on our cardiac unit protocols. The main causes of low cardiac output after surgical correction of heart congenital disease are reviewed, and methods of treatment and support are proposed as derived from the relevant literature and our protocols.

  9. Giant Cardiac Cavernous Hemangioma.

    Science.gov (United States)

    Unger, Eric; Costic, Joseph; Laub, Glenn

    2015-07-01

    We report the case of an asymptomatic giant cardiac cavernous hemangioma in a 71-year-old man. The intracardiac mass was discovered incidentally during surveillance for his prostate cancer; however, the patient initially declined intervention. On presentation to our institution 7 years later, the lesion had enlarged significantly, and the patient consented to excision. At surgery, an 8 × 6.5 × 4.8 cm intracardiac mass located on the inferior heart border was excised with an intact capsule through a median sternotomy approach. The patient had an uneventful postoperative course. We discuss the diagnostic workup, treatment, and characteristics of this rare cardiac tumor. PMID:26140782

  10. Radiography in cardiology [cardiac disorders, cardiac insufficiency

    International Nuclear Information System (INIS)

    The diagnostic procedure in cardiology nearly always requires an X-ray examination of the thorax. This examination is very informative when it is correctly performed and interpreted. The radiographs need to be read precisely and comprehensively: this includes the evaluation of the silhouette of the heart (size, form and position) as well as the examination of extra-cardiac thoracic structures allowing among other things to search for signs of cardiac insufficiency. The conclusion of the X-ray examination can be drawn after having brought together information concerning the case history, the clinical examination and the study of the radiographs. The radiologist finds himself in one of three situations: (1) the information provided by the X-ray pictures is characteristic of a disease and permits a diagnosis, (2) the X-ray pictures indicate a group of hypotheses; further complementary tests could be useful and (3) the X-ray pictures provide ambiguous even contradictory information; it is necessary to complete the radiological examination by other techniques such as an ultrasonographic study of the heart

  11. Serum myoglobin after cardiac catheterisation.

    OpenAIRE

    McComb, J. M.; McMaster, E A

    1982-01-01

    Study of 80 consecutive patients undergoing elective diagnostic cardiac catheterisation showed that after the procedure 25 (31%) developed myoglobinaemia. This was attributed to complications of the catheterisation in two. The remaining 23 had received premedication by intramuscular injection. In patients without intramuscular injections myoglobinaemia did not occur after uncomplicated cardiac catheterisation. The study did not support the proposition that cardiac catheterisation results in m...

  12. Cardiac arrest during gamete release in chum salmon regulated by the parasympathetic nerve system.

    Directory of Open Access Journals (Sweden)

    Yuya Makiguchi

    Full Text Available Cardiac arrest caused by startling stimuli, such as visual and vibration stimuli, has been reported in some animals and could be considered as an extraordinary case of bradycardia and defined as reversible missed heart beats. Variability of the heart rate is established as a balance between an autonomic system, namely cholinergic vagus inhibition, and excitatory adrenergic stimulation of neural and hormonal action in teleost. However, the cardiac arrest and its regulating nervous mechanism remain poorly understood. We show, by using electrocardiogram (ECG data loggers, that cardiac arrest occurs in chum salmon (Oncorhynchus keta at the moment of gamete release for 7.39+/-1.61 s in females and for 5.20+/-0.97 s in males. The increase in heart rate during spawning behavior relative to the background rate during the resting period suggests that cardiac arrest is a characteristic physiological phenomenon of the extraordinarily high heart rate during spawning behavior. The ECG morphological analysis showed a peaked and tall T-wave adjacent to the cardiac arrest, indicating an increase in potassium permeability in cardiac muscle cells, which would function to retard the cardiac action potential. Pharmacological studies showed that the cardiac arrest was abolished by injection of atropine, a muscarinic receptor antagonist, revealing that the cardiac arrest is a reflex response of the parasympathetic nerve system, although injection of sotalol, a beta-adrenergic antagonist, did not affect the cardiac arrest. We conclude that cardiac arrest during gamete release in spawning release in spawning chum salmon is a physiological reflex response controlled by the parasympathetic nervous system. This cardiac arrest represents a response to the gaping behavior that occurs at the moment of gamete release.

  13. Hepato-cardiac disorders

    Institute of Scientific and Technical Information of China (English)

    Yasser; Mahrous; Fouad; Reem; Yehia

    2014-01-01

    Understanding the mutual relationship between the liver and the heart is important for both hepatologists and cardiologists. Hepato-cardiac diseases can be classified into heart diseases affecting the liver, liver diseases affecting the heart, and conditions affecting the heart and the liver at the same time. Differential diagnoses of liver injury are extremely important in a cardiologist’s clinical practice calling for collaboration between cardiologists and hepatologists due to the many other diseases that can affect the liver and mimic haemodynamic injury. Acute and chronic heart failure may lead to acute ischemic hepatitis or chronic congestive hepatopathy. Treatment in these cases should be directed to the primary heart disease. In patients with advanced liver disease, cirrhotic cardiomyopathy may develop including hemodynamic changes, diastolic and systolic dysfunctions, reduced cardiac performance and electrophysiological abnormalities. Cardiac evaluation is important for patients with liver diseases especially before and after liver transplantation. Liver transplantation may lead to the improvement of all cardiac changes and the reversal of cirrhotic cardiomyopathy. There are systemic diseases that may affect both the liver and the heart concomitantly including congenital, metabolic and inflammatory diseases as well as alcoholism. This review highlights these hepatocardiac diseases

  14. Primary cardiac tumors

    International Nuclear Information System (INIS)

    Cardiac tumors happen to be among the less known pathologies without clear treatment standards. Even one decade ago most of the cardiac tumor diagnosis were made post mortem, and only reports of isolated cases could be found in the literature, showing the lack of interest in the investigation of these pathologies by cardiology and cardiovascular surgery specialists. With the development of echocardiography and of cardiovascular surgery, more cases of primary and metastatic cardiac tumors have been diagnosed. Many cases have been treated by palliative or curative surgical interventions, thus increasing the reports in the world literature and the experience in this field, and pointing out the real incidence of these pathologies, not being as bizarre as it had been considered. a revision of the literature will be made, in which the frequency and the suggested interventions will be reported, as well as the cases of cardiac pathology in two cardiovascular centers of the country known by the author. The echocardiographic, pathologic and histological characteristics of the representative cases will be presented, without a greater evidence level, due to the problem's incidence and the few cases reported by these centers

  15. Cardiac MRI tagging

    International Nuclear Information System (INIS)

    Cardiac MRI tagging is an original technique based upon the perturbation of the magnetization of determined regions of the myocardium (tags). The motion of the tags accurately reflects the deformation of the underlying tissue. Data analysis requires special techniques to reconstruct the 3D motion of the heart, and to evaluate the myocardial strain, locally and throughout the whole heart. (authors)

  16. Automatic Implantable Cardiac Defibrillator

    Medline Plus

    Full Text Available ... Over the next hour you'll see the implantation of an automated implantable cardiac defibrillator. The surgery ... evening we're going to be discussing the implantation of a defibrillator. It’s a battery-powered implantable ...

  17. Cardiac effects of vasopressin.

    Science.gov (United States)

    Pelletier, Jean-Sébastien; Dicken, Bryan; Bigam, David; Cheung, Po-Yin

    2014-07-01

    Vasopressin is an essential hormone involved in the maintenance of cardiovascular homeostasis. It has been in use therapeutically for many decades, with an emphasis on its vasoconstrictive and antidiuretic properties. However, this hormone has a ubiquitous influence and has specific effects on the heart. Although difficult to separate from its powerful vascular effects in the clinical setting, a better understanding of vasopressin's direct cardiac effects could lead to its more effective clinical use for a variety of shock states by maximizing its therapeutic benefit. The cardiac-specific effects of vasopressin are complex and require further elucidation. Complicating our understanding include the various receptors and secondary messengers involved in vasopressin's effects, which may lead to various results based on differing doses and varying environmental conditions. Thus, there have been contradictory reports on vasopressin's action on the coronary vasculature and on its effect on inotropy. However, beneficial results have been found and warrant further study to expand the potential therapeutic role of vasopressin. This review outlines the effect of vasopressin on the coronary vasculature, cardiac contractility, and on hypertrophy and cardioprotection. These cardiac-specific effects of vasopressin represent an interesting area for further study for potentially important therapeutic benefits. PMID:24621650

  18. Cardiac pacemaker power sources

    International Nuclear Information System (INIS)

    A review of chemical and radioisotope batteries used in cardiac pacemakers is presented. The battery systems are examined in terms of longevity, reliability, cost, size and shape, energy density, weight, internal resistance versus time, end-of-life voltage, chemical compatibility, and potential failure mechanisms

  19. REN: a novel, developmentally regulated gene that promotes neural cell differentiation.

    Science.gov (United States)

    Gallo, Rita; Zazzeroni, Francesca; Alesse, Edoardo; Mincione, Claudia; Borello, Ugo; Buanne, Pasquale; D'Eugenio, Roberta; Mackay, Andrew R; Argenti, Beatrice; Gradini, Roberto; Russo, Matteo A; Maroder, Marella; Cossu, Giulio; Frati, Luigi; Screpanti, Isabella; Gulino, Alberto

    2002-08-19

    Expansion and fate choice of pluripotent stem cells along the neuroectodermal lineage is regulated by a number of signals, including EGF, retinoic acid, and NGF, which also control the proliferation and differentiation of central nervous system (CNS) and peripheral nervous system (PNS) neural progenitor cells. We report here the identification of a novel gene, REN, upregulated by neurogenic signals (retinoic acid, EGF, and NGF) in pluripotent embryonal stem (ES) cells and neural progenitor cell lines in association with neurotypic differentiation. Consistent with a role in neural promotion, REN overexpression induced neuronal differentiation as well as growth arrest and p27Kip1 expression in CNS and PNS neural progenitor cell lines, and its inhibition impaired retinoic acid induction of neurogenin-1 and NeuroD expression. REN expression is developmentally regulated, initially detected in the neural fold epithelium of the mouse embryo during gastrulation, and subsequently throughout the ventral neural tube, the outer layer of the ventricular encephalic neuroepithelium and in neural crest derivatives including dorsal root ganglia. We propose that REN represents a novel component of the neurogenic signaling cascade induced by retinoic acid, EGF, and NGF, and is both a marker and a regulator of neuronal differentiation. PMID:12186855

  20. [Cardiac amyloidosis. General review].

    Science.gov (United States)

    Laraki, R

    1994-04-01

    Cardiac amyloidosis, most often of AL type, is a non-exceptional disease as it represents 5 to 10% of non-ischemic cardiomyopathies. It realizes typically a restrictive cardiomyopathy. Nevertheless the wide diversity of possible presentation makes it a "big shammer" which must be evoked in front of every unexplained cardiopathy after the age of forty. If some associated manifestations can rapidly suggest the diagnosis, as a peripheric neuropathy especially a carpal tunnel syndrome or palpebral ecchymosis, cardiac involvement can also evolve in an apparently isolated way. The most suggestive paraclinic elements for the diagnosis are, in one hand, the increased myocardial echogenicity with a "granular sparkling" appearance seen throughout all walls of the left ventricle and, in the other hand, the association of a thickened left ventricle and a low voltage (electrocardiogram could also show pseudo-infarct Q waves). In front of such aspects, the proof of amyloidosis is brought by an extra-cardiac biopsy or by scintigraphy with labelled serum amyloid P component, so that the indications of endomyocardial biopsy are very limited today. The identification of the amyloid nature of a cardiopathy has an direct therapeutic implication: it contra-indicates the use of digitalis, calcium channel blockers and beta-blockers. The treatment of AL amyloidosis (chemotherapy with alkylant agents) remains very unsatisfactory especially in the cardiac involvement which is the most frequent cause of death (in AL amyloidosis). Last, cardiac amyloidosis is a bad indication for transplantation which results are burden by rapid progression of deposits especially in the gastro-intestinal tract and the nervous system. PMID:8059146

  1. Cardiac surgery outcomes.

    Science.gov (United States)

    Halpin, Linda S; Barnett, Scott D; Beachy, Jim

    2003-01-01

    Accrediting organizations and payers are demanding valid and reliable data that demonstrate the value of services. Federal agencies, healthcare industry groups, and healthcare watchdog groups are increasing the demand for public access to outcomes data. A new and growing outcomes dynamic is the information requested by prospective patients in an increasingly consumer-oriented business. Patients demand outcomes, and resources are developing to meet these demands. Physicians are increasingly confronted with requests for information about their mortality and morbidity rates, malpractice suits, and disciplinary actions received. For example, in Virginia, prospective patients have access to data provided by the nonprofit group Virginia Health Information. After numerous resolutions by the Virginia Senate since 1999, the prospective Virginia medical consumer now has access to several annual publications: Virginia Hospitals: A Consumer's Guide, 1999 Annual Report and Strategic Plan Update, and the 1999 Industry Report: Virginia Hospitals and Nursing Facilities. Consumers have access to cardiac outcomes data stratified by hospital, gender, and cardiac service line (cardiac surgery, noninvasive cardiology, and invasive cardiology). This is particularly relevant to IHI because Virginia Health Information specifically targets cardiac care. IHI has a sizable investment in cardiovascular outcomes and has found outcomes measurement and research are key to providing quality care. IHI's goal is to move from an outcomes management model to a disease management model. The hope is to incorporate all aspects of the patient's continuum of care, from preoperative and diagnostic services through cardiac interventions to postoperative rehabilitation. Furthermore, every step along the way will be supported with functional status and quality of life assessments. Although these goals are ambitious and expensive, the return on investment is high. PMID:14618772

  2. Risk factors and the effect of cardiac resynchronization therapy on cardiac and non-cardiac mortality in MADIT-CRT

    DEFF Research Database (Denmark)

    Perkiomaki, Juha S; Ruwald, Anne-Christine; Kutyifa, Valentina;

    2015-01-01

    causes, 108 (63.9%) deemed cardiac, and 61 (36.1%) non-cardiac. In multivariate analysis, increased baseline creatinine was significantly associated with both cardiac and non-cardiac deaths [hazard ratio (HR) 2.97, P ...AIMS: To understand modes of death and factors associated with the risk for cardiac and non-cardiac deaths in patients with cardiac resynchronization therapy with implantable cardioverter-defibrillator (CRT-D) vs. implantable cardioverter-defibrillator (ICD) therapy, which may help clarify...

  3. Auditory stimulation and cardiac autonomic regulation

    Directory of Open Access Journals (Sweden)

    Vitor E. Valenti

    2012-08-01

    Full Text Available Previous studies have already demonstrated that auditory stimulation with music influences the cardiovascular system. In this study, we described the relationship between musical auditory stimulation and heart rate variability. Searches were performed with the Medline, SciELO, Lilacs and Cochrane databases using the following keywords: "auditory stimulation", "autonomic nervous system", "music" and "heart rate variability". The selected studies indicated that there is a strong correlation between noise intensity and vagal-sympathetic balance. Additionally, it was reported that music therapy improved heart rate variability in anthracycline-treated breast cancer patients. It was hypothesized that dopamine release in the striatal system induced by pleasurable songs is involved in cardiac autonomic regulation. Musical auditory stimulation influences heart rate variability through a neural mechanism that is not well understood. Further studies are necessary to develop new therapies to treat cardiovascular disorders.

  4. Population structure and mating system of the Red-crested Korhaan (Lophotis ruficrista) in South Africa

    Institute of Scientific and Technical Information of China (English)

    Johann H van Niekerk

    2015-01-01

    Background:The mating system of the korhaans and bustards in southern Africa is either based on polygyny or monogamy. The Red-crested Korhaan (Lophotis ruficrista) has been described as polygynous but otherwise very little is known about its breeding biology. The aims were to describe the population structure and male behavior during breeding. Methods:The data collected for this paper was mainly based on field transect surveys carried out in 2009, 2010 and 2011. The population structure of the Red-crested Korhaan in the temperate Borakalalo Game Reserve (BGR) was compared with that in the arid Molopo Nature Reserve (MNR) (both situated in the North West province of South Africa). The study was mainly conducted in the BGR but additional work was conducted in the MNR for comparison. Results:The difference in mean group sizes between MNR (1.03) and BGR (1.07) was statistically not significant. Group sizes were not affected by climate despite the fact that the BGR received about 650 mm precipitation per annum and the MNR about 200 mm. In both reserves the apparent sex ratios were skewed in favor of males (1:0.29 in the BGR and 1:0.1 in the MNR). The population was dispersed in a clumped manner which is ascribed to the formation of leks. Leks were positioned in open habitat while females invariably concealed themselves under cover. Conclusions:The leks formed the pivot of the mating system of the Red-crested Korhaan and are identifiable social structures that field ecologists can use to monitor population stability.

  5. Neural Tube Defects

    Science.gov (United States)

    Neural tube defects are birth defects of the brain, spine, or spinal cord. They happen in the first month ... that she is pregnant. The two most common neural tube defects are spina bifida and anencephaly. In spina bifida, ...

  6. An archaic crested plesiosaur in opal from the Lower Cretaceous high-latitude deposits of Australia

    OpenAIRE

    Kear, Benjamin P.; Schroeder, Natalie I; Michael S Y Lee

    2006-01-01

    Umoonasaurus demoscyllus gen. et sp. nov. is a new small-bodied (approx. 2.5 m) pliosauroid plesiosaur from the Lower Cretaceous (Aptian–Albian) of southern Australia. It is represented by several partial skeletons (one with a near complete skull is the most complete opalized vertebrate fossil yet known), and is unique in having large crests on the skull midline and above the orbits. Umoonasaurus is surprisingly archaic despite its relatively late age (approx. 115 Myr ago)—being simultaneousl...

  7. A Priori Estimates for Two-Dimensional Water Waves with Angled Crests

    OpenAIRE

    Kinsey, Rafe H.; Wu, Sijue

    2014-01-01

    We consider the two-dimensional water wave problem in the case where the free interface of the fluid meets a vertical wall at a possibly non-right angle; our problem also covers interfaces with angled crests. We assume that the fluid is inviscid, incompressible, and irrotational, with no surface tension and with air density zero. We construct a low-regularity energy and prove a closed energy estimate for this problem. Our work differs from earlier work in that, in our case, only a degenerate ...

  8. The Crest of the Peacock Non-European Roots of Mathematics (Third Edition)

    CERN Document Server

    Joseph, George Gheverghese

    2011-01-01

    From the Ishango Bone of central Africa and the Inca quipu of South America to the dawn of modern mathematics, The Crest of the Peacock makes it clear that human beings everywhere have been capable of advanced and innovative mathematical thinking. George Gheverghese Joseph takes us on a breathtaking multicultural tour of the roots and shoots of non-European mathematics. He shows us the deep influence that the Egyptians and Babylonians had on the Greeks, the Arabs' major creative contributions, and the astounding range of successes of the great civilizations of India and China. The third editio

  9. T-CREST: Time-predictable multi-core architecture for embedded systems

    DEFF Research Database (Denmark)

    Schoeberl, Martin; Abbaspourseyedi, Sahar; Jordan, Alexander;

    2015-01-01

    -core architectures that are optimized for the WCET instead of the average-case execution time. The resulting time-predictable resources (processors, interconnect, memory arbiter, and memory controller) and tools (compiler, WCET analysis) are designed to ease WCET analysis and to optimize WCET performance. Compared...... domain shows that the WCET can be reduced for computation-intensive tasks when distributing the tasks on several cores and using the network-on-chip for communication. With three cores the WCET is improved by a factor of 1.8 and with 15 cores by a factor of 5.7.The T-CREST project is the result...

  10. Optical Neural Interfaces

    OpenAIRE

    Warden, Melissa R.; Cardin, Jessica A.; Deisseroth, Karl

    2014-01-01

    Genetically encoded optical actuators and indicators have changed the landscape of neuroscience, enabling targetable control and readout of specific components of intact neural circuits in behaving animals. Here, we review the development of optical neural interfaces, focusing on hardware designed for optical control of neural activity, integrated optical control and electrical readout, and optical readout of population and single-cell neural activity in freely moving mammals.

  11. Reconstruction of iliac crest with rib to prevent donor site complications: A prospective study of 26 cases

    Directory of Open Access Journals (Sweden)

    Dave B

    2007-01-01

    Full Text Available Background: The tricortical bone graft from the iliac crest are used to reconstruct the post corpectomy spinal defects. The donor iliac area defect is large and may give rise to pain at donor site, instability of pelvis, fracture of ilium, donor site muscle herniation or abdominal content herniation. Rib removed during thoracotomy was used by us to reconstruct the iliac crest defect. Materials and Methods: Twenty-six patients who underwent thoracotomy for dorsal spine corpectomy or curettage for various spinal pathologies from June 2002 to May 2004 were included in the study. After adequate decompression the spine was reconstructed by tricortical bone graft from iliac crest and reconstruction of the iliac crest was done with the rib removed for exposure during thoracotomy. Results: The mean follow up was 15 months. All patients had good graft incorporation which was evaluated on the basis of local tenderness and radiographs. One patient had graft displacement. Conclusion: The reconstruction of iliac crest by rib is a simple and effective procedure to prevent donor site complications.

  12. Genetics and evolution of plumage color in Crested Ibis: Analysis of the melanocortin-1 receptor (MC1R).

    Science.gov (United States)

    Yang, J; Liu, X; Zhang, J; Qing, B; Lu, B

    2015-01-01

    The melanocortin-1-recepter gene (MC1R), an important regulator in melanin synthesis, may cause different plumage color patterns in birds: gain-of-function mutations lead to the synthesis of eumelanin, whereas loss-of-function mutations help to generate pheomelanin synthesis. We had chosen MC1R as a candidate gene for the depigmentation of crested ibis, cloned and sequenced the crested ibis MC1R gene the first time. The crested ibis MC1R sequence, highly conserved with other birds during evolution, had seven transmembrane domains which played an indispensable function through evolution. We did not found any substitution on this sequence among all the sample individuals. The phylogenetic tree showed that crested ibis separated early in the evolution of birds. TYR, TYRP1, TYRP2 and MC1R were expressed in blood and the expression of the four genes showed no significant difference (p>0.05) between normal and albinism individuals, and this result demonstrated that melanic pigments are not involved in the production of red pigmentation in birds. Further study of the crested ibis albinism should focus on analyzing carotenoid-based genes. PMID:26314199

  13. Cardiac fusion and complex congenital cardiac defects in thoracopagus twins: diagnostic value of cardiac CT

    Energy Technology Data Exchange (ETDEWEB)

    Goo, Hyun Woo [University of Ulsan College of Medicine, Asan Medical Center, Department of Radiology and Research Institute of Radiology, Seoul (Korea, Republic of); Park, Jeong-Jun [University of Ulsan College of Medicine, Asan Medical Center, Department of Pediatric Cardiac Surgery, Seoul (Korea, Republic of); Kim, Ellen Ai-Rhan [University of Ulsan College of Medicine, Asan Medical Center, Division of Neonatology, Department of Pediatrics, Seoul (Korea, Republic of); Won, Hye-Sung [University of Ulsan College of Medicine, Asan Medical Center, Department of Obstetrics and Gynecology, Seoul (Korea, Republic of)

    2014-09-15

    Most thoracopagus twins present with cardiac fusion and associated congenital cardiac defects, and assessment of this anatomy is of critical importance in determining patient care and outcome. Cardiac CT with electrocardiographic triggering provides an accurate and quick morphological assessment of both intracardiac and extracardiac structures in newborns, making it the best imaging modality to assess thoracopagus twins during the neonatal period. In this case report, we highlight the diagnostic value of cardiac CT in thoracopagus twins with an interatrial channel and complex congenital cardiac defects. (orig.)

  14. Holographic neural networks

    OpenAIRE

    Manger, R

    1998-01-01

    Holographic neural networks are a new and promising type of artificial neural networks. This article gives an overview of the holographic neural technology and its possibilities. The theoretical principles of holographic networks are first reviewed. Then, some other papers are presented, where holographic networks have been applied or experimentally evaluated. A case study dealing with currency exchange rate prediction is described in more detail.

  15. Cardiac arrest in children

    Directory of Open Access Journals (Sweden)

    Tress Erika

    2010-01-01

    Full Text Available Major advances in the field of pediatric cardiac arrest (CA were made during the last decade, starting with the publication of pediatric Utstein guidelines, the 2005 recommendations by the International Liaison Committee on Resuscitation, and culminating in multicenter collaborations. The epidemiology and pathophysiology of in-hospital and out-of-hospital CA are now well described. Four phases of CA are described and the term "post-cardiac arrest syndrome" has been proposed, along with treatment goals for each of its four phases: immediate post-arrest, early post-arrest, intermediate and recovery phase. Hypothermia is recommended to be considered as a therapy for post-CA syndrome in comatose patients after CA, and large multicenter prospective studies are underway. We reviewed landmark articles related to pediatric CA published during the last decade. We present the current knowledge of epidemiology, pathophysiology and treatment of CA relevant to pre-hospital and acute care health practitioners.

  16. Cardiac arrest in children.

    Science.gov (United States)

    Tress, Erika E; Kochanek, Patrick M; Saladino, Richard A; Manole, Mioara D

    2010-07-01

    Major advances in the field of pediatric cardiac arrest (CA) were made during the last decade, starting with the publication of pediatric Utstein guidelines, the 2005 recommendations by the International Liaison Committee on Resuscitation, and culminating in multicenter collaborations. The epidemiology and pathophysiology of in-hospital and out-of-hospital CA are now well described. Four phases of CA are described and the term "post-cardiac arrest syndrome" has been proposed, along with treatment goals for each of its four phases: immediate post-arrest, early post-arrest, intermediate and recovery phase. Hypothermia is recommended to be considered as a therapy for post-CA syndrome in comatose patients after CA, and large multicenter prospective studies are underway. We reviewed landmark articles related to pediatric CA published during the last decade. We present the current knowledge of epidemiology, pathophysiology and treatment of CA relevant to pre-hospital and acute care health practitioners. PMID:20930971

  17. Socially differentiated cardiac rehabilitation

    DEFF Research Database (Denmark)

    Meillier, Lucette Kirsten; Nielsen, Kirsten Melgaard; Larsen, Finn Breinholt;

    2012-01-01

    recruitment and participation among low educated and socially vulnerable patients must be addressed to lower inequality in post-MI health. Our aim was to improve referral, attendance, and adherence rates among socially vulnerable patients by systematic screening and by offering a socially differentiated...... standard rehabilitation programme (SRP). If patients were identified as socially vulnerable, they were offered an extended version of the rehabilitation programme (ERP). Excluded patients were offered home visits by a cardiac nurse. Concordance principles were used in the individualised programme elements......%. Patients were equally distributed to the SRP and the ERP. No inequality was found in attendance and adherence among referred patients. Conclusions: It seems possible to overcome unequal referral, attendance, and adherence in cardiac rehabilitation by organisation of systematic screening and social...

  18. Cardiac metastases of osteosarcoma

    International Nuclear Information System (INIS)

    Osteosarcoma is a malignancy whose various sites of metastasis greatly modify its ultimate prognosis. We report a case of simultaneous pulmonary and cardiac metastases in a 41-year-old male patient with osteosarcoma of the tibia, presenting after more then one year of completion of adjuvant therapy with progressive dyspnea and cyanosis. Diagnosis was made on computerized tomogram and echocardiogram. The metastatic mass entirely occupying the right ventricle and the pulmonary artery proved fatal. (author)

  19. Cardiac Tissue Engineering

    OpenAIRE

    MILICA RADISIC; GORDANA VUNJAK-NOVAKOVIC

    2009-01-01

    We hypothesized that clinically sized (1-5 mm thick),compact cardiac constructs containing physiologically high density of viable cells (~108 cells/cm3) can be engineered in vitro by using biomimetic culture systems capable of providing oxygen transport and electrical stimulation, designed to mimic those in native heart. This hypothesis was tested by culturing rat heart cells on polymer scaffolds, either with perfusion of culture medium (physiologic interstitial velocity, supplementation of p...

  20. Cardiac developmental toxicity

    OpenAIRE

    Mahler, Gretchen J.; Jonathan T Butcher

    2011-01-01

    Congenital heart disease is a highly prevalent problem with mostly unknown origins. Many cases of CHD likely involve an environmental exposure coupled with genetic susceptibility, but practical and ethical considerations make nongenetic causes of CHD difficult to assess in humans. The development of the heart is highly conserved across all vertebrate species, making animal models an excellent option for screening potential cardiac teratogens. This review will discuss exposures known to cause ...

  1. Penetrating Cardiac Injuries

    OpenAIRE

    ÖZYAZICIOĞLU, Ahmet

    2002-01-01

    Objectives: To present our experience of penetrating cardiac injuries treated at Atatürk University hospital; in 17 years 38 patients were analyzed. Methods: Patients were classified into three groups: group A (stable), 12; group B (shock), 21; and group C (agonal), five. Five patients were treated by pericardial window and three by pericardiocentesis. Two patients in group C, 19 patients in group B and five patients in group A underwent median sternotomy or thoracotomy in the operating room...

  2. Theoretical Investigation of Peak-Delay Force Reduction for Caissons Exposed to Non-breaking Short-Crested Waves

    DEFF Research Database (Denmark)

    Burcharth, H. F.; Liu, Z.

    In nature coastal structures are exposed to oblique short-crested waves. The effect of wave incident angle on total wave force on a long caisson are twofold. The one is the force reduction due to the reduction of instantaneous point pressure on the caisson, named point-pressure force reduction. The...... other is the force reduction due to the fact that the peak pressures do not occur simultaneously along the caisson, named peak-delay force reduction. These two reduction effects can also be expected with short-crested waves, as the short-crestedness of waves means the spreading of wave energy over a...... on the peak-delay force reduction of caissons exposed to non-breaking short-crested waves. Battjes (1982) has investigated theoretically the peak-delay force reduction of shortcrested waves with only one frequency component. Such a force reduction factor cannot be applied because in nature waves are...

  3. Benign cardiac tumours: cardiac CT and MRI imaging appearances

    International Nuclear Information System (INIS)

    Full text: Primary benign cardiac tumours are rarely found in clinical practice and are generally evaluated with echocardiography. However, with the increasing usage of helical multislice CT, the initial detection and evaluation of these masses may be made by the radiologist during routine daily practice for other indications. The echocardiographic, CT and cardiac MRI appearances of various benign cardiac tumours and masses are described and illustrated in this review

  4. Cardiac tissue engineering

    Directory of Open Access Journals (Sweden)

    MILICA RADISIC

    2005-03-01

    Full Text Available We hypothesized that clinically sized (1-5 mm thick,compact cardiac constructs containing physiologically high density of viable cells (~108 cells/cm3 can be engineered in vitro by using biomimetic culture systems capable of providing oxygen transport and electrical stimulation, designed to mimic those in native heart. This hypothesis was tested by culturing rat heart cells on polymer scaffolds, either with perfusion of culture medium (physiologic interstitial velocity, supplementation of perfluorocarbons, or with electrical stimulation (continuous application of biphasic pulses, 2 ms, 5 V, 1 Hz. Tissue constructs cultured without perfusion or electrical stimulation served as controls. Medium perfusion and addition of perfluorocarbons resulted in compact, thick constructs containing physiologic density of viable, electromechanically coupled cells, in contrast to control constructs which had only a ~100 mm thick peripheral region with functionally connected cells. Electrical stimulation of cultured constructs resulted in markedly improved contractile properties, increased amounts of cardiac proteins, and remarkably well developed ultrastructure (similar to that of native heart as compared to non-stimulated controls. We discuss here the state of the art of cardiac tissue engineering, in light of the biomimetic approach that reproduces in vitro some of the conditions present during normal tissue development.

  5. Misexpression of Pknox2 in mouse limb bud mesenchyme perturbs zeugopod development and deltoid crest formation.

    Science.gov (United States)

    Zhou, Wenrong; Zhu, Huang; Zhao, Jianzhi; Li, Hanjun; Wan, Yong; Cao, Jingjing; Zhao, Haixia; Yu, Jian; Zhou, Rujiang; Yao, Yiyun; Zhang, Lingling; Wang, Lifang; He, Lin; Ma, Gang; Yao, Zhengju; Guo, Xizhi

    2013-01-01

    The TALE (Three Amino acid Loop Extension) family consisting of Meis, Pbx and Pknox proteins is a group of transcriptional co-factors with atypical homeodomains that play pivotal roles in limb development. Compared to the in-depth investigations of Meis and Pbx protein functions, the role of Pknox2 in limb development remains unclear. Here, we showed that Pknox2 was mainly expressed in the zeugopod domain of the murine limb at E10.5 and E11.5. Misexpression of Pknox2 in the limb bud mesenchyme of transgenic mice led to deformities in the zeugopod and forelimb stylopod deltoid crest, but left the autopod and other stylopod skeletons largely intact. These malformations in zeugopod skeletons were recapitulated in mice overexpressing Pknox2 in osteochondroprogenitor cells. Molecular and cellular analyses indicated that the misexpression of Pknox2 in limb bud mesenchyme perturbed the Hox10-11 gene expression profiles, decreased Col2 expression and Bmp/Smad signaling activity in the limb. These results indicated that Pknox2 misexpression affected mesenchymal condensation and early chondrogenic differentiation in the zeugopod skeletons of transgenic embryos, suggesting Pknox2 as a potential regulator of zeugopod and deltoid crest formation. PMID:23717575

  6. Misexpression of Pknox2 in mouse limb bud mesenchyme perturbs zeugopod development and deltoid crest formation.

    Directory of Open Access Journals (Sweden)

    Wenrong Zhou

    Full Text Available The TALE (Three Amino acid Loop Extension family consisting of Meis, Pbx and Pknox proteins is a group of transcriptional co-factors with atypical homeodomains that play pivotal roles in limb development. Compared to the in-depth investigations of Meis and Pbx protein functions, the role of Pknox2 in limb development remains unclear. Here, we showed that Pknox2 was mainly expressed in the zeugopod domain of the murine limb at E10.5 and E11.5. Misexpression of Pknox2 in the limb bud mesenchyme of transgenic mice led to deformities in the zeugopod and forelimb stylopod deltoid crest, but left the autopod and other stylopod skeletons largely intact. These malformations in zeugopod skeletons were recapitulated in mice overexpressing Pknox2 in osteochondroprogenitor cells. Molecular and cellular analyses indicated that the misexpression of Pknox2 in limb bud mesenchyme perturbed the Hox10-11 gene expression profiles, decreased Col2 expression and Bmp/Smad signaling activity in the limb. These results indicated that Pknox2 misexpression affected mesenchymal condensation and early chondrogenic differentiation in the zeugopod skeletons of transgenic embryos, suggesting Pknox2 as a potential regulator of zeugopod and deltoid crest formation.

  7. 3D laboratory experiments on a system of low-crested breakwaters under oblique wave attack

    Science.gov (United States)

    Papacharalampous, Georgia; Karantinos, Michalis; Giantsi, Theodora; Moutzouris, Constantinos

    2016-04-01

    Low-crested breakwaters are being increasingly used for shore protection. Hydrodynamics around coastal structures are complicated and have not been fully understood. A series of large scale (1:40) 3D laboratory experiments were carried out in the Laboratory of Harbour Works, National Technical University of Athens to investigate the wave disturbance around a system of two non-parallel to the shoreline breakwaters. The structures were of the type of low-crested, permeable and attacked by obliquely incident waves. Three different water depths were tested in the basin with a range of various different spectra. The transmission and reflection coefficients were measured in the middle of each breakwater. For this purpose, 1 gauge and 4 gauges (in line) were placed on the landward and seaward side of each breakwater respectively. The effect of diffraction is incorporate at the measured wave heights. The measured coefficients are being compared to their corresponding estimated using existing empirical formulas. Most of those formulas neglect wave obliquity.

  8. Modelling shock to detonation transition in PETN using HERMES and CREST

    Science.gov (United States)

    Maheswaran, Mary-Ann; Curtis, John; Reaugh, Jack

    2013-06-01

    The High Explosive Response to MEchanical Stimulus (HERMES) model has been developed to address High Explosive Violent Response (HEVR). It is a material model for use in the both the LS-DYNA finite element and ALE3D hydrocodes that enables the modelling of both shock to detonation (SDT) and deflagration to detonation (DDT) transition. As part of its ongoing development and application, model parameters for the explosive PETN were found by using experimental data for PETN at different densities. PETN was selected because of the availability of both SDT and DDT data. To model SDT and DDT, HERMES uses a subset of the CREST reactive burn model with the Mie-Gruneisen equation of state (EOS) for the unreacted explosive and a look-up table for the gas EOS as generated by Cheetah. The unreacted EOS parameters were found first by calculating the principal isentrope of unreacted PETN at TMD from PETN shock Hugoniot data. Then Pop-plot data for PETN was used to fit the CREST parameters at each density. The resulting new PETN HERMES material model provides a platform for further investigations of SDT and DDT in low density PETN powder. JER's activity was performed under the auspices of the US DOE by LLNL under Contract DE-AC52-07NA27344, and partially funded by the Joint US DoD/DOE Munitions Technology Development Program.

  9. Clinical effectiveness of 99mTc-diphosphonate scintigraphy of revascularized iliac crest flaps

    International Nuclear Information System (INIS)

    Clinical assessment of the perfusion of the musculocutaneous portion of composite iliac crest free flaps was compared to 99mTc-diphosphonate (HDP) uptake in 14 patients who underwent primary oromandibular reconstruction after ablative cancer surgery. Bone scanning was performed on average at the 9-10th postoperative day (range 4-48) 3 h after intravenous injection of 550 MBq 99mTc-HDP. Eleven patients showed complete concordance between 99mTc-HDP uptake and soft-tissue status. Two patients showed uptake and viable muscle in spite of necrotic skin. One patient had a viable musculocutaneous flap but a photopenic defect in the bone graft; 6 months later, a small corresponding part of the bone was sequestrated. In this study, bone scanning and clinical assessment of muscle perfusion were 100% accurate in predicting viability of bone graft. Skin viability was a less reliable parameter. It is concluded that bone scanning is not indicated as routine investigation for revascularized iliac crest flaps and that clinical assessment of muscle perfusion is a reliable monitor of the early function of such flaps. (au) 8 refs

  10. Combination of microvascular medial femoral condyle and iliac crest flap for hemi-midface reconstruction.

    Science.gov (United States)

    Brandtner, C; Hachleitner, J; Buerger, H; Gaggl, A

    2015-06-01

    In midface defects including the orbit (Brown class III and IV), no single flap can provide adequate reconstruction. In this technical note, the combination of vascularized iliac crest flap and vascularized medial femoral condyle flap (MFC) is described. The vascularized iliac crest flap is reported to be the gold standard for maxilla reconstruction. There is, however, no consensus on the best method for orbital and nasal wall reconstruction. The MFC flap can be harvested as a thin corticoperiosteal flap or as an osteomyocutaneous flap. Due to the periosteal blood supply, this flap can be customized for an individual defect of the upper hemi-midface. It is therefore of great benefit in orbital and nasal wall reconstruction. By combining the deep circumflex iliac artery (DCIA) bone flap and the MFC flap, the best standard reconstruction technique of the hemi-maxilla can be combined with a new anatomical precise microvascular reconstruction technique of the orbit. A nearly symmetric midface appearance can be achieved. PMID:25835757

  11. Tibial crest fracture correction after tibial tuberosity advancement (TTA using a modified TTA technique

    Directory of Open Access Journals (Sweden)

    Tiago Carmagnani Prada

    2015-06-01

    Full Text Available Corrective osteotomies are challenging techniques that require specialized training and acquisition of specific materials. Nevertheless, they have been increasingly studied and used in clinical routine in the world. Several variations on the model and the application technique have been developed and refined in search of the improvement of surgical techniques and development of implants more affordable to purchase. The tibial tuberosity advancement (TTA consists on stabilization of tibial plateau perpendicular to the patellar tendon through the tibial tuberosity advancement. Our goal is to report a surgical complication of fracture of the tibial crest after TTA procedure. A dog with a confirmed diagnosis of rupture of the cranial cruciate ligament (CCLR was operated using conventional technique of TTA. After 3 days of surgery, the same animal had a fracture of the proximal tibial crest. The animal was sent back to surgery and was used a variation of TTA technique, with autologous iliac wing and three cortical screws. This variation of the technique was able to replace the original technique successfully.

  12. Levels of complexity in scale-invariant neural signals

    Science.gov (United States)

    Ivanov, Plamen Ch.; Ma, Qianli D. Y.; Bartsch, Ronny P.

    2012-02-01

    Many physiological systems exhibit complex scale-invariant and nonlinear features characterized long-range power-law correlations, indicating a possibly common control mechanism. It has been suggested that dynamical processes, influenced by inputs and feedback on multiple time scales, may be sufficient to give rise to this complexity. Two examples of physiologic signals that are the output of hierarchical multiscale physiologic systems under neural control are the human heartbeat and human gait. We show that while both cardiac interbeat interval and gait interstride interval time series under healthy conditions have comparable scale-invariant behavior, they still belong to different complexity classes. We compare results from empirical findings and stochastic feedback modeling approaches to cardiac and locomotor dynamics, which provide new insights into the multicomponent neural mechanisms regulating these complex systems.

  13. Indeterminacy of Spatiotemporal Cardiac Alternans

    CERN Document Server

    Zhao, Xiaopeng

    2007-01-01

    Cardiac alternans, a beat-to-beat alternation in action potential duration (at the cellular level) or in ECG morphology (at the whole heart level), is a marker of ventricular fibrillation, a fatal heart rhythm that kills hundreds of thousands of people in the US each year. Investigating cardiac alternans may lead to a better understanding of the mechanisms of cardiac arrhythmias and eventually better algorithms for the prediction and prevention of such dreadful diseases. In paced cardiac tissue, alternans develops under increasingly shorter pacing period. Existing experimental and theoretical studies adopt the assumption that alternans in homogeneous cardiac tissue is exclusively determined by the pacing period. In contrast, we find that, when calcium-driven alternans develops in cardiac fibers, it may take different spatiotemporal patterns depending on the pacing history. Because there coexist multiple alternans solutions for a given pacing period, the alternans pattern on a fiber becomes unpredictable. Usin...

  14. Biosynthesis of cardiac natriuretic peptides

    DEFF Research Database (Denmark)

    Goetze, Jens Peter

    2010-01-01

    Cardiac-derived peptide hormones were identified more than 25 years ago. An astonishing amount of clinical studies have established cardiac natriuretic peptides and their molecular precursors as useful markers of heart disease. In contrast to the clinical applications, the biogenesis of cardiac p...... competent endocrine cells. The structurally related atrial natriuretic peptide will be mentioned where appropriate, whereas C-type natriuretic peptide will not be considered as a cardiac peptide of relevance in mammalian physiology....... characterized. An ongoing characterization of the molecular heterogeneity will help appreciate the biosynthetic capacity of the endocrine heart and could introduce new diagnostic possibilities. Notably, different biosynthetic products may not be equal markers of the same pathophysiological processes. An...... inefficient post-translational prohormone maturation will also affect the biology of the cardiac natriuretic peptide system. This review aims at summarizing the myocardial synthesis of natriuretic peptides focusing on B-type natriuretic peptide, where new data has disclosed cardiac myocytes as highly...

  15. Biosynthesis of cardiac natriuretic peptides

    DEFF Research Database (Denmark)

    Goetze, Jens Peter

    2010-01-01

    Cardiac-derived peptide hormones were identified more than 25 years ago. An astonishing amount of clinical studies have established cardiac natriuretic peptides and their molecular precursors as useful markers of heart disease. In contrast to the clinical applications, the biogenesis of cardiac...... inefficient post-translational prohormone maturation will also affect the biology of the cardiac natriuretic peptide system. This review aims at summarizing the myocardial synthesis of natriuretic peptides focusing on B-type natriuretic peptide, where new data has disclosed cardiac myocytes as highly...... competent endocrine cells. The structurally related atrial natriuretic peptide will be mentioned where appropriate, whereas C-type natriuretic peptide will not be considered as a cardiac peptide of relevance in mammalian physiology....

  16. An overview of cardiac morphogenesis.

    Science.gov (United States)

    Schleich, Jean-Marc; Abdulla, Tariq; Summers, Ron; Houyel, Lucile

    2013-11-01

    Accurate knowledge of normal cardiac development is essential for properly understanding the morphogenesis of congenital cardiac malformations that represent the most common congenital anomaly in newborns. The heart is the first organ to function during embryonic development and is fully formed at 8 weeks of gestation. Recent studies stemming from molecular genetics have allowed specification of the role of cellular precursors in the field of heart development. In this article we review the different steps of heart development, focusing on the processes of alignment and septation. We also show, as often as possible, the links between abnormalities of cardiac development and the main congenital heart defects. The development of animal models has permitted the unraveling of many mechanisms that potentially lead to cardiac malformations. A next step towards a better knowledge of cardiac development could be multiscale cardiac modelling. PMID:24138816

  17. Automatic Classification of Heartbeats Using Wavelet Neural Network

    OpenAIRE

    BENALI, Radhwane; Bereksi-Reguig, Fethi; HADJ SLIMANE, Zinedine

    2012-01-01

    The electrocardiogram (ECG) signal is widely employed as one of the most important tools in clinical practice in order to assess the cardiac status of patients. The classification of the ECG into different pathologic disease categories is a complex pattern recognition task. In this paper, we propose a method for ECG heartbeat pattern recognition using wavelet neural network (WNN). To achieve this objective, an algorithm for QRS detection is first implemented, then a WN...

  18. Sudden Cardiac Death in Athletes.

    Science.gov (United States)

    Wasfy, Meagan M; Hutter, Adolph M; Weiner, Rory B

    2016-01-01

    There are clear health benefits to exercise; even so, patients with cardiac conditions who engage in exercise and athletic competition may on rare occasion experience sudden cardiac death (SCD). This article reviews the epidemiology and common causes of SCD in specific athlete populations. There is ongoing debate about the optimal mechanism for SCD prevention, specifically regarding the inclusion of the ECG and/or cardiac imaging in routine preparticipation sports evaluation. This controversy and contemporary screening recommendations are also reviewed. PMID:27486488

  19. Cardiac Rehabilitation: Guidelines and Recommendations

    OpenAIRE

    Catherine Monpere

    1998-01-01

    Cardiac rehabilitation has been shown to improve exercise tolerance and symptomatology in patients experiencing angina or heart failure and reduce long term mortality after myocardial infarction, with a good cost-effectiveness ratio. In addition to these `hard' endpoints, cardiac rehabilitation improves the patient's quality of life and risk factor profile through a multifactorial intervention. Indeed, cardiac rehabilitation is no longer restricted to physical reconditioning, but should now b...

  20. Chaotic diagonal recurrent neural network

    Institute of Scientific and Technical Information of China (English)

    Wang Xing-Yuan; Zhang Yi

    2012-01-01

    We propose a novel neural network based on a diagonal recurrent neural network and chaos,and its structure andlearning algorithm are designed.The multilayer feedforward neural network,diagonal recurrent neural network,and chaotic diagonal recurrent neural network are used to approach the cubic symmetry map.The simulation results show that the approximation capability of the chaotic diagonal recurrent neural network is better than the other two neural networks.

  1. Chaotic diagonal recurrent neural network

    International Nuclear Information System (INIS)

    We propose a novel neural network based on a diagonal recurrent neural network and chaos, and its structure and learning algorithm are designed. The multilayer feedforward neural network, diagonal recurrent neural network, and chaotic diagonal recurrent neural network are used to approach the cubic symmetry map. The simulation results show that the approximation capability of the chaotic diagonal recurrent neural network is better than the other two neural networks. (interdisciplinary physics and related areas of science and technology)

  2. Diagnostic imaging of cardiac hypertrophy

    International Nuclear Information System (INIS)

    As imaging techniques for cardiac hypertrophy, the ultrasonic dimension gauze technique, echocardiography, ventriculography and the RI technique including emission RI tomography were outlined. (Chiba, N.)

  3. Evolvable Neural Software System

    Science.gov (United States)

    Curtis, Steven A.

    2009-01-01

    The Evolvable Neural Software System (ENSS) is composed of sets of Neural Basis Functions (NBFs), which can be totally autonomously created and removed according to the changing needs and requirements of the software system. The resulting structure is both hierarchical and self-similar in that a given set of NBFs may have a ruler NBF, which in turn communicates with other sets of NBFs. These sets of NBFs may function as nodes to a ruler node, which are also NBF constructs. In this manner, the synthetic neural system can exhibit the complexity, three-dimensional connectivity, and adaptability of biological neural systems. An added advantage of ENSS over a natural neural system is its ability to modify its core genetic code in response to environmental changes as reflected in needs and requirements. The neural system is fully adaptive and evolvable and is trainable before release. It continues to rewire itself while on the job. The NBF is a unique, bilevel intelligence neural system composed of a higher-level heuristic neural system (HNS) and a lower-level, autonomic neural system (ANS). Taken together, the HNS and the ANS give each NBF the complete capabilities of a biological neural system to match sensory inputs to actions. Another feature of the NBF is the Evolvable Neural Interface (ENI), which links the HNS and ANS. The ENI solves the interface problem between these two systems by actively adapting and evolving from a primitive initial state (a Neural Thread) to a complicated, operational ENI and successfully adapting to a training sequence of sensory input. This simulates the adaptation of a biological neural system in a developmental phase. Within the greater multi-NBF and multi-node ENSS, self-similar ENI s provide the basis for inter-NBF and inter-node connectivity.

  4. Cardiac MR image segmentation using CHNN and level set method

    Institute of Scientific and Technical Information of China (English)

    王洪元; 周则明; 王平安; 夏德深

    2004-01-01

    Although cardiac magnetic resonance imaging (MRI) can provide high spatial resolution image, the area gray level inhomogenization, weak boundary and artifact often can be found in MR images. So, the MR images segmentation using the gradient-based methods is poor in quality and efficiency. An algorithm, based on the competitive hopfield neural network (CHNN) and the curve propagation, is proposed for cardiac MR images segmentation in this paper. The algorithm is composed of two phases. In first phase, a CHNN is used to classify the image objects, and to make gray level homogenization and to recognize weak boundaries in objects. In second phase, based on the classified results, the level set velocity function is created and the object boundaries are extracted with the curve propagation algorithm of the narrow band-based level set. The test results are promising and encouraging.

  5. Slit/Robo1 signaling regulates neural tube development by balancing neuroepithelial cell proliferation and differentiation

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Guang; Li, Yan; Wang, Xiao-yu [Key Laboratory for Regenerative Medicine of The Ministry of Education, Department of Histology and Embryology, School of Medicine, Jinan University, Guangzhou 510632 (China); Han, Zhe [Institute of Vascular Biological Sciences, Guangdong Pharmaceutical University, Guangzhou 510224 (China); Chuai, Manli [College of Life Sciences Biocentre, University of Dundee, Dundee DD1 5EH (United Kingdom); Wang, Li-jing [Institute of Vascular Biological Sciences, Guangdong Pharmaceutical University, Guangzhou 510224 (China); Ho Lee, Kenneth Ka [Stem Cell and Regeneration Thematic Research Programme, School of Biomedical Sciences, Chinese University of Hong Kong, Shatin (Hong Kong); Geng, Jian-guo, E-mail: jgeng@umich.edu [Institute of Vascular Biological Sciences, Guangdong Pharmaceutical University, Guangzhou 510224 (China); Department of Biologic and Materials Sciences, University of Michigan School of Dentistry, Ann Arbor, MI 48109 (United States); Yang, Xuesong, E-mail: yang_xuesong@126.com [Key Laboratory for Regenerative Medicine of The Ministry of Education, Department of Histology and Embryology, School of Medicine, Jinan University, Guangzhou 510632 (China)

    2013-05-01

    Formation of the neural tube is the morphological hallmark for development of the embryonic central nervous system (CNS). Therefore, neural tube development is a crucial step in the neurulation process. Slit/Robo signaling was initially identified as a chemo-repellent that regulated axon growth cone elongation, but its role in controlling neural tube development is currently unknown. To address this issue, we investigated Slit/Robo1 signaling in the development of chick neCollege of Life Sciences Biocentre, University of Dundee, Dundee DD1 5EH, UKural tube and transgenic mice over-expressing Slit2. We disrupted Slit/Robo1 signaling by injecting R5 monoclonal antibodies into HH10 neural tubes to block the Robo1 receptor. This inhibited the normal development of the ventral body curvature and caused the spinal cord to curl up into a S-shape. Next, Slit/Robo1 signaling on one half-side of the chick embryo neural tube was disturbed by electroporation in ovo. We found that the morphology of the neural tube was dramatically abnormal after we interfered with Slit/Robo1 signaling. Furthermore, we established that silencing Robo1 inhibited cell proliferation while over-expressing Robo1 enhanced cell proliferation. We also investigated the effects of altering Slit/Robo1 expression on Sonic Hedgehog (Shh) and Pax7 expression in the developing neural tube. We demonstrated that over-expressing Robo1 down-regulated Shh expression in the ventral neural tube and resulted in the production of fewer HNK-1{sup +} migrating neural crest cells (NCCs). In addition, Robo1 over-expression enhanced Pax7 expression in the dorsal neural tube and increased the number of Slug{sup +} pre-migratory NCCs. Conversely, silencing Robo1 expression resulted in an enhanced Shh expression and more HNK-1{sup +} migrating NCCs but reduced Pax7 expression and fewer Slug{sup +} pre-migratory NCCs were observed. In conclusion, we propose that Slit/Robo1 signaling is involved in regulating neural tube

  6. Slit/Robo1 signaling regulates neural tube development by balancing neuroepithelial cell proliferation and differentiation

    International Nuclear Information System (INIS)

    Formation of the neural tube is the morphological hallmark for development of the embryonic central nervous system (CNS). Therefore, neural tube development is a crucial step in the neurulation process. Slit/Robo signaling was initially identified as a chemo-repellent that regulated axon growth cone elongation, but its role in controlling neural tube development is currently unknown. To address this issue, we investigated Slit/Robo1 signaling in the development of chick neCollege of Life Sciences Biocentre, University of Dundee, Dundee DD1 5EH, UKural tube and transgenic mice over-expressing Slit2. We disrupted Slit/Robo1 signaling by injecting R5 monoclonal antibodies into HH10 neural tubes to block the Robo1 receptor. This inhibited the normal development of the ventral body curvature and caused the spinal cord to curl up into a S-shape. Next, Slit/Robo1 signaling on one half-side of the chick embryo neural tube was disturbed by electroporation in ovo. We found that the morphology of the neural tube was dramatically abnormal after we interfered with Slit/Robo1 signaling. Furthermore, we established that silencing Robo1 inhibited cell proliferation while over-expressing Robo1 enhanced cell proliferation. We also investigated the effects of altering Slit/Robo1 expression on Sonic Hedgehog (Shh) and Pax7 expression in the developing neural tube. We demonstrated that over-expressing Robo1 down-regulated Shh expression in the ventral neural tube and resulted in the production of fewer HNK-1+ migrating neural crest cells (NCCs). In addition, Robo1 over-expression enhanced Pax7 expression in the dorsal neural tube and increased the number of Slug+ pre-migratory NCCs. Conversely, silencing Robo1 expression resulted in an enhanced Shh expression and more HNK-1+ migrating NCCs but reduced Pax7 expression and fewer Slug+ pre-migratory NCCs were observed. In conclusion, we propose that Slit/Robo1 signaling is involved in regulating neural tube development by tightly

  7. Cardiac manifestations of myotonic dystrophy type 1

    DEFF Research Database (Denmark)

    Petri, Helle; Vissing, John; Witting, Nanna; Bundgaard, Henning; Køber, Lars

    2012-01-01

    To estimate the degree of cardiac involvement regarding left ventricular ejection fraction, conduction abnormalities, arrhythmia, risk of sudden cardiac death (SCD) and the associations between cardiac involvement and cytosine-thymine-guanine (CTG)-repeat, neuromuscular involvement, age and gender...

  8. Antifibrinolytics in cardiac surgery

    Directory of Open Access Journals (Sweden)

    Achal Dhir

    2013-01-01

    Full Text Available Cardiac surgery exerts a significant strain on the blood bank services and is a model example in which a multi-modal blood-conservation strategy is recommended. Significant bleeding during cardiac surgery, enough to cause re-exploration and/or blood transfusion, increases morbidity and mortality. Hyper-fibrinolysis is one of the important contributors to increased bleeding. This knowledge has led to the use of anti-fibrinolytic agents especially in procedures performed under cardiopulmonary bypass. Nothing has been more controversial in recent times than the aprotinin controversy. Since the withdrawal of aprotinin from the world market, the choice of antifibrinolytic agents has been limited to lysine analogues either tranexamic acid (TA or epsilon amino caproic acid (EACA. While proponents of aprotinin still argue against its non-availability. Health Canada has approved its use, albeit under very strict regulations. Antifibrinolytic agents are not without side effects and act like double-edged swords, the stronger the anti-fibrinolytic activity, the more serious the side effects. Aprotinin is the strongest in reducing blood loss, blood transfusion, and possibly, return to the operating room after cardiac surgery. EACA is the least effective, while TA is somewhere in between. Additionally, aprotinin has been implicated in increased mortality and maximum side effects. TA has been shown to increase seizure activity, whereas, EACA seems to have the least side effects. Apparently, these agents do not differentiate between pathological and physiological fibrinolysis and prevent all forms of fibrinolysis leading to possible thrombotic side effects. It would seem prudent to select the right agent knowing its risk-benefit profile for a given patient, under the given circumstances.

  9. Single ventricle cardiac defect

    International Nuclear Information System (INIS)

    Single ventricle heart is defined as a rare cardiac abnormality with a single ventricle chamber involving diverse functional and physiological defects. Our case is of a ten month-old baby boy who died shortly after admission to the hospital due to vomiting and diarrhoea. Autopsy findings revealed cyanosis of finger nails and ears. Internal examination revealed; large heart, weighing 60 grams, single ventricle, without a septum and upper membranous part. Single ventricle is a rare pathology, hence, this paper aims to discuss this case from a medico-legal point of view. (author)

  10. "A taste for the beautiful": latent aesthetic mate preferences for white crests in two species of Australian grassfinches.

    Science.gov (United States)

    Burley, N T; Symanski, R

    1998-12-01

    Darwin first hypothesized that bright colors and elaborate ornamentation of male animals evolved in response to the "aesthetic" mate preferences of females. By this reasoning, potentially costly male secondary sexual traits may evolve not in response to selection for demonstration of vigor but, rather, in response to latent, nonfunctional preferences by females. Recent comparative evidence for this phenomenon is equivocal. Here we present experimental evidence that two avian species from a lineage devoid of crested species have mate preferences for opposite sex conspecifics wearing artificial white crests. Other colors of crests that have been studied are not preferred. Preferences for white crests did not diminish over the longest experimental interval (12 wk). These results are additional powerful evidence for highly structured aesthetic mate preferences in estrildine finches. Sex differences in the expression of preferences, and the widespread occurrence of facial ornamentation in birds, suggest that the preference "structure" is influenced by the central nervous system. We hypothesize that aesthetic preferences are a potent force in the early evolution of sexually selected traits, and that "indicator" traits evolve secondarily from traits initially favored by aesthetic preferences. PMID:18811428

  11. Crest Level Optimization of the Multi Level Overtopping based Wave Energy Converter Seawave Slot-Cone Generator

    DEFF Research Database (Denmark)

    Kofoed, Jens Peter; Osaland, E.

    2005-01-01

    The paper describes the optimization of the crest levels and geometrical layout of the SSG structure, focusing on maximizing the obtained potential energy in the overtopping water. During wave tank testing at AAU average overtopping rates into the individual reservoirs have been measured. The...

  12. Single-blinded prospective randomized study comparing open versus needle technique for obtaining autologous cancellous bone from the iliac crest.

    NARCIS (Netherlands)

    Bartels, R.H.M.A.

    2005-01-01

    One of the most frequent complications of cervical anterior discectomy with fusion is pain at the donor site, usually the iliac crest. Despite the advent of new materials, autologous bone is still the "gold standard" for fusion procedures. A prospective, single blinded, randomized study was performe

  13. Cryptic crested newt diversity at the Eurasian transition: the mitochondrial DNA phylogeography of Near Eastern Triturus newts.

    Science.gov (United States)

    Wielstra, B; Themudo, G Espregueira; Güçlü, O; Olgun, K; Poyarkov, N A; Arntzen, J W

    2010-09-01

    Crested newts of the Triturus karelinii group occur in a phylogeographically understudied region: the Near East. Controversy surrounds the systematic position of these newts within the complete crested newt assemblage (the Triturus cristatus superspecies). We explore the situation using mitochondrial sequence data (ND2 and ND4, approximately 1.7kb) and employing different methods of phylogenetic inference (Bayesian inference and Maximum Likelihood using mixed models) and molecular dating (r8s and BEAST). The T. karelinii group is monophyletic and constitutes one of four main lineages in the T. cristatus superspecies. The separation of the T. karelinii group from the remaining crested newts around 9Ma is related to the formation of the Mid-Aegean Trench, which separated the Balkan and Anatolian landmasses. The T. karelinii group comprises three geographically structured clades (eastern, central and western). The genetic divergence shown by these clades is comparable to that among recognized crested newt species. We suggest the uplift of the Armenian Plateau to be responsible for the separation of the eastern clade around 7Ma, and the re-establishment of a marine connection between the Black Sea and the Mediterranean at the end of the Messinian Salinity Crisis to have caused the split between the central and western clade around 5.5Ma. Genetic structuring within the three clades dates to the Quaternary Ice Age (<2.59Ma) and is associated with alternating periods of isolation and reconnection caused by periodic changes in sea level and surface runoff. PMID:20435147

  14. MANAGEMENT TECHNIQUES TO MINIMIZE DOUBLE-CRESTED CORMORANTS AND OTHER FISH-EATING BIRDS AT AQUACULTURE FACILITIES.

    Science.gov (United States)

    Methods used to minimize double-crested cormorant (Phalacrocorax auritus) and other fish-eating birds at aquaculture facilities have limited success because birds acclimate or adjust to the technique. During 2000-2001, a technique using twine strung at 30 m intervals across 8 catfish ponds was test...

  15. Generation of Branch Coverage Test Data for Simulink/Stateflow Models Using Crest Tool

    Directory of Open Access Journals (Sweden)

    Sangharatna Godboley

    2013-12-01

    Full Text Available Automated test suite generation is an optimization technique to reduce test effort and duration. Software Testing has traditionally been one of the main techniques contributing to high software quality and dependability. Testing performance consumes about 50% of software development resources, so any methods aiming at reducing software- testing costs are likely to reduce software development costs. So an automated generation of test cases is highly required. Modelling technology has been introduced into the software testing field. Even though how to perform the testing is difficult task, in this approach we are testing using simulation modelling and by using testing methods we are generating MC/DC test cases. In our approach, the first system is modelled in MATLAB using Simulink/Stateflow tool. After that we are generating code from the Simulink/Stateflow models. We use that code to generate the test data using Concolic tester CREST Tool. Concolic testing is used in avionics systems in an efficient way.

  16. Head Discharge Relationship of Thin Plated Rectangular Lab Fabricated Sharp Crested Weirs

    Directory of Open Access Journals (Sweden)

    S. A. Tekade

    2016-01-01

    Full Text Available Measuring open channel flows has been a major challenge at the field level. Because of the fact that the measuring devices are to be made from procedures and materials prescribed in standard codes. Weirs over a period of time had been used to measure discharges in open channel systems. But non-availability of standard material at village level proves to be a major bottleneck in implementing weirs as field measurement devices. The present experimental study is an attempt to prove the good hydraulic performance of weirs made of locally available metal sheets. That use of complicated material and machining is not necessary in the fabrication of rectangular weir. A discharge formula for the rectangular weir of different sizes is extensively studied. From the experimental study it is concluded that the Cd value for each weir is nearly same. Also material and slight variation in thickness has no effect on the Cd value in case of rectangular sharp crested weir.

  17. Solar cycle variation of the total electron content around equatorial anomaly crest region in east asia

    Science.gov (United States)

    Huang, Yinn-Nien; Cheng, Kang

    1995-10-01

    The monthly mean hourly values of total electron content data obtained at Lunping Observatory (geographic coordinates 25.00°N, 121.17°E; geomagnetic coordinates 14.3°N, 191.3°E) by using the ETS2 satellite beacon signal during the period from March 1977 to December 1990 have been used to analyze the solar cycle variations of total electron content (TEC) around equatorial anomaly crest region in East Asia. Positive, correlations were found between the 12 month running average of monthly mean TECs and sunspot numbers. By using the linear regression analysis method, the contour charts for real diurnal and seasonal variations of TEC at certain sunspot numbers were constructed and described. The diurnal variation of TEC was represented by the sum of its diurnal mean and first three harmonic components. The solar cycle variations of these components have also been discussed.

  18. Coastal defence through low crested breakwater structures: jumping out of the frying pan into the fire?

    Science.gov (United States)

    Munari, Cristina; Corbau, Corinne; Simeoni, Umberto; Mistri, Michele

    2011-08-01

    The Adriatic coast of Punta Marina (Ravenna) is protected by 3-km long low crested breakwater structures (LCSs). Through a 3-years long multidisciplinar study, we assessed the impact of such defensive structures on environmental and biological condition. LCSs create pools where conditions are very different from the surrounding nearshore system. Mechanical disturbance by currents and waves varied greatly in intensity and frequency between seaward and landward sides of the structures. Sedimentary budget was positive at the landward side, but it was due to a gain on the seafloor and not on the emerged beach. The budget at seaward was negative. LCSs determine differences in benthic assemblages, alter the seasonal pattern of communities, and modify seasonal fluctuations of animal assemblages. Landward sheltered areas can be seen as "lagoonal island" surrounded by a "sea of marine habitat". Differences in ecological quality status, obtained through M-AMBI, are due to the sum of these factors. PMID:21722927

  19. Crest Factor Reduction in MC-CDMA Employing Carrier Interferometry Codes

    Directory of Open Access Journals (Sweden)

    Natarajan Balasubramaniam

    2004-01-01

    Full Text Available This paper addresses signal compactness issues in MC-CDMA employing carrier interferometry codes using the measure of crest factor (CF. Carrier interferometry codes, applied to N -carrier MC-CDMA systems, enable 2N users to simultaneously share the system bandwidth with minimal degradation in performance (relative to the N -orthogonal-user case. First, for a fully loaded ( K=N and K=2N users MC-CDMA system with practical values of N , it is shown that the CF in downlink transmission demonstrates desirable properties of low mean and low variance. The downlink CF degrades when the number of users in the system decreases. Next, the high CF observed in the uplink is characterized and the poor CF in a partially loaded downlink as well as uplink is effectively combated using Schroeder's analytical CF reduction techniques.

  20. Hypokalemia and sudden cardiac death

    DEFF Research Database (Denmark)

    Kjeldsen, Keld

    2010-01-01

    Worldwide, approximately three million people suffer sudden cardiac death annually. These deaths often emerge from a complex interplay of substrates and triggers. Disturbed potassium homeostasis among heart cells is an example of such a trigger. Thus, hypokalemia and, also, more transient...... of fatal arrhythmia and sudden cardiac death a patient is, the more attention should be given to the potassium homeostasis....

  1. Atrial tumors in cardiac MRI

    International Nuclear Information System (INIS)

    Cardiac magnetic resonance imaging (MRI) is an important tool for the diagnosis of cardiac masses. Various cardiac tumors are predisposed to occurring in atrial structures. The aim of this review article is the description of atrial tumors and their morphological features in MRI. In general, cardiac tumors are rare: approximately 0.001-0.03% in autopsy studies. About 75% of them are benign. The most common cardiac tumor is the myxoma. They are predisposed to occur in the atria and show a characteristically strong hyperintense signal on T2-wieghted images in MRI. In other sequences a heterogeneous pattern reflects its variable histological appearance. Lipomas exhibit a signal behavior identical to fatty tissue with a typical passive movement in cine imaging. Fibroelastomas are the most common tumors of the cardiac valves. Consisting of avascular fibrous tissue, they often present with hypointense signal intensities. Thrombi attached to their surface can cause severe emboli even in small tumors. Amongst primary cardiac malignancies, sarcomas are most common and favor the atria. Secondary malignancies of the heart are far more common than primary ones (20-40 times). In case of known malignancies, approximately 10% of patients develop cardiac metastasis at the end of their disease. Lymphogenic metastases favor the pericardium, while hematogenic spread prefers the myocardium. Since they are not real atrial tumors, thrombi and anatomical structures of the atria have to be differentiated from other pathologies. (orig.)

  2. Cardiac arrest – cardiopulmonary resuscitation

    Directory of Open Access Journals (Sweden)

    Basri Lenjani

    2014-01-01

    Conclusions: All survivors from cardiac arrest have received appropriate medical assistance within 10 min from attack, which implies that if cardiac arrest occurs near an institution health care (with an opportunity to provide the emergent health care the rate of survival is higher.

  3. Fluvastatin attenuates diabetes-induced cardiac sympathetic neuropathy in association with a decrease in oxidative stress

    International Nuclear Information System (INIS)

    Increased oxidative stress might contribute to diabetic (DM) neuropathy, so the effects of long-term treatment with fluvastatin (FL) on myocardial oxidative stress and cardiac sympathetic neural function were investigated in diabetic rats. FL (10 mg·kg-1·day-1, DM-FL) or vehicle (DM-VE) was orally administered for 2 weeks to streptozotocin-induced DM rats. Cardiac oxidative stress was determined by myocardial 8-iso-prostaglandin F2α (PGF2α) and nicotinamide adenine dinucleotide (NADPH) oxidase subunit p22phox mRNA expression. Sympathetic neural function was quantified by autoradiography using 131I- and 125I-metaiodobenzylguanidine (MIBG). FL did not affect plasma glucose levels but remarkably decreased PGF2α levels compared with DM-VE rats (13.8±9.2 vs 175.0±93.9 ng/g tissue), although PGF2α levels were below the detection limit in non-DM rats. FL significantly reduced myocardial p22phox mRNA expression. Cardiac 131I-MIBG uptake was lower in DM-VE rats than in non-DM rats, but the decrease was attenuated in DM-FL rats (1.31±0.08, 1.88±0.22, and 1.58±0.18%kg dose/g, respectively, P<0.01). Cardiac MIBG clearance was not affected by the induction of DM or by FL, indicating that the reduced MIBG uptake in DM rats might result from impaired neural function. FL ameliorates cardiac sympathetic neural dysfunction in DM rats in association with attenuation of increased myocardial oxidative stress. (author)

  4. Neural Systems Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — As part of the Electrical and Computer Engineering Department and The Institute for System Research, the Neural Systems Laboratory studies the functionality of the...

  5. A neural flow estimator

    DEFF Research Database (Denmark)

    Jørgensen, Ivan Harald Holger; Bogason, Gudmundur; Bruun, Erik

    1995-01-01

    This paper proposes a new way to estimate the flow in a micromechanical flow channel. A neural network is used to estimate the delay of random temperature fluctuations induced in a fluid. The design and implementation of a hardware efficient neural flow estimator is described. The system is...... implemented using switched-current technique and is capable of estimating flow in the μl/s range. The neural estimator is built around a multiplierless neural network, containing 96 synaptic weights which are updated using the LMS1-algorithm. An experimental chip has been designed that operates at 5 V with a...

  6. Root Mean Square Acceleration (RMS, Crest Factor and Hand- Arm Vibration Dose Value In Tiller Users

    Directory of Open Access Journals (Sweden)

    PARVIN NASSIRI

    2015-10-01

    Full Text Available The purpose of this study was to assess exposure to hand-arm vibration in tiller users, Forty users of tiller in northeastern provinces of Iran were examined to measure hand-arm vibration parameters such as root mean square acceleration (RMS, total equivalent acceleration, Vibration Dose Value (VDV and crest factor in three directions (x, y, and z and various operating modes for comparing them with the relevant permitted standard levels. The hand-arm vibration measurement was done according to the standards ISO 5349-1 and ISO 5349-2. The obtained results indicated that the exposure level in three modes of rota-tilling, transportation and idling were equal to 16.95, 14.16 and 8.65 m/s2, respectively. In all measurement modes, the exposure to vibration in the direction x was greater than that of y and z. Moreover, the average crest factor was calculated less than six. The highest vibration dose values were measured in rota-tilling mode when the tiller was in 2nd  gear (60.76 m/s1.75 and 1st gear (56.83 m/s1.75. The results indicated that the permitted working time was only few seconds and there was a risk of musculoskeletal disorders. The present study emphasizes on the need for interventional and control managerial measures to eliminate or reduce hand-arm vibration transmitted to the tiller users' hands for avoiding major problems such as musculoskeletal disorders, discomfort and  premature fatigue. In this regard, further studies are required to identify vibration sources in different types of tillers.

  7. Pneumothorax in cardiac pacing

    DEFF Research Database (Denmark)

    Kirkfeldt, Rikke Esberg; Johansen, Jens Brock; Nohr, Ellen Aagaard;

    2012-01-01

    AIM: To identify risk factors for pneumothorax treated with a chest tube after cardiac pacing device implantation in a population-based cohort.METHODS AND RESULTS: A nationwide cohort study was performed based on data on 28 860 patients from the Danish Pacemaker Register, which included all Danish...... patients who received their first pacemaker (PM) or cardiac resynchronization device from 1997 to 2008. Multiple logistic regression was used to estimate adjusted odds ratios (aOR) with 95% confidence intervals for the association between risk factors and pneumothorax treated with a chest tube. The median...... age was 77 years (25th and 75th percentile: 69-84) and 55% were male (n = 15 785). A total of 190 patients (0.66%) were treated for pneumothorax, which was more often in women [aOR 1.9 (1.4-2.6)], and in patients with age >80 years [aOR 1.4 (1.0-1.9)], a prior history of chronic obstructive pulmonary...

  8. Leadership in cardiac surgery.

    Science.gov (United States)

    Rao, Christopher; Patel, Vanash; Ibrahim, Michael; Ahmed, Kamran; Wong, Kathie A; Darzi, Ara; von Segesser, Ludwig K; Athanasiou, Thanos

    2011-06-01

    Despite the efficacy of cardiac surgery, less invasive interventions with more uncertain long-term outcomes are increasingly challenging surgery as first-line treatment for several congenital, degenerative and ischemic cardiac diseases. The specialty must evolve if it is to ensure its future relevance. More importantly, it must evolve to ensure that future patients have access to treatments with proven long-term effectiveness. This cannot be achieved without dynamic leadership; however, our contention is that this is not enough. The demands of a modern surgical career and the importance of the task at hand are such that the serendipitous emergence of traditional charismatic leadership cannot be relied upon to deliver necessary change. We advocate systematic analysis and strategic leadership at a local, national and international level in four key areas: Clinical Care, Research, Education and Training, and Stakeholder Engagement. While we anticipate that exceptional individuals will continue to shape the future of our specialty, the creation of robust structures to deliver collective leadership in these key areas is of paramount importance. PMID:20884217

  9. Cardiac chamber scintiscanning

    International Nuclear Information System (INIS)

    The two methods of cardiac chamber scintiscanning, i.e. 'first pass' and 'ECG-triggered' examinations, are explained and compared. Two tables indicate the most significant radiation doses of the applied radio tracers, i.e. 99m-Tc-pertechnetate and 99m-Tc-HSA, to which a patient is exposed. These averaged values are calculated from various data given in specialised literature. On the basis of data given in literature, an effective half-life of approximately 5 hours in the intravascular space was calculated for the erythrocytes labelled with technetium 99m. On this basis, the radiation doses for the patients due to 99m-Tc-labelled erythrocytes are estimated. The advantages and disadvantages of the two methods applied for cardiac chamber scintiscanning are put into contrast and compared with the advantages and disadvantages of the quantitative X-ray cardiography of the left heart. The still existing problems connected with the assessment of ECG-triggered images are discussed in detail. The author performed investigations of his own, which concerned the above-mentioned problems. (orig./MG)

  10. Affect intensity and cardiac arousal.

    Science.gov (United States)

    Blascovich, J; Brennan, K; Tomaka, J; Kelsey, R M; Hughes, P; Coad, M L; Adlin, R

    1992-07-01

    Relationships between affect intensity and basal, evoked, and perceived cardiac arousal were investigated in 3 experiments. Affect intensity was assessed using Larsen and Diener's (1987) Affect Intensity Measure (AIM). Cardiac arousal was evoked with exercise in the 1st study and with mental arithmetic in the 2nd and 3rd. Perceived cardiac arousal was measured under optimal conditions using a standard heartbeat discrimination procedure. Women as a group scored higher on the AIM. Affect intensity was unrelated to basal or evoked cardiac arousal and was negatively related to perceived cardiac arousal in all 3 studies. Data suggest that affect intensity, although unrelated to actual physiological arousal, is negatively related to the accuracy with which individuals perceive their own arousal. Results are discussed within the context of an expanded arousal-regulation model (Blascovich, 1990). PMID:1494983

  11. Comparison of fracture site callus with iliac crest bone marrow as the source of plastic-adherent cells

    Directory of Open Access Journals (Sweden)

    Achmad Zaki

    2013-05-01

    Full Text Available Background: Red marrow has been described as the main source of mesenchymal stem cells although its aspiration and isolation from bone marrow was reported to have significant donor site morbidity. Since secondary bone healing occurs through formation of callus as the result of proliferation and differentiation of mesenchymal stem cells, callus may become alternative source for mesenchymal stem cells. In this study, we compared the number of plastic-adherent cells from fracture site callus and bone marrow of iliac crest after two and four weeks of culture.Methods: Sixteen New Zealand rabbits were fracturized at the femoral shaft. Then, these rabbits were taken care. After two weeks of fracturization, 3 mL iliac crest bone marrow aspiration and callus extraction of eight rabbits were cultured (group I. The other eight rabbits were treated equally after four weeks of fracturization (group II. Simultaneously, the cultures were observed after one and two weeks. Four weeks later, they were harvested. Cells were counted using Neubauer hemocytometer. The average number of cells between the sources and groups were statistically analyzed using the unpaired t-test. Results: In group I, there were 2.6 ± 0.1 x 104 cells in the culture of iliac crest bone marrow aspirate and 2.5 ± 0.1 x 104 cells in culture of callus extract from fracture site (p = 0.34. In group II, there were 2.7 ± 0.1 x 104 cells and 2.1 ± 0.1 x 104 cells, respectively (p < 0.001.Conclusion: Fracture site callus at the second week post-fracturization may be potential as source of plastic-adherent cells compared with iliac crest bone marrow. (Med J Indones. 2013;22:70-5Keywords: Bone marrow, fracture site callus, iliac crest, long bone, mesenchymal stem cell, plastic-adherent cells

  12. New technique for feline carbon dioxide laser onychectomy by resection of the redundant epidermis of the ungual crest

    Science.gov (United States)

    Young, William P.

    2000-05-01

    A new technique for feline carbon dioxide laser onychectomy can further minimize postoperative pain and complications in any age animal. This procedure is accomplished by resection of the redundant epidermis over the ungual crest. Resection of the redundant epidermis allows complete dissection and removal of the claw from a strictly cranio-dorsal approach, thereby minimizing trauma to the surrounding tissues and post- operative complications. The laser setting is preferred at four to six watts continuous power. The epidermis of the ungual crest is resected in a circumferential manner at its most distal edge. This tissue is pushed proximally over the ungual crest. A second circumferential incision is made 3 mm proximal to the first incision. Deeper subcutaneous fascia is also pushed proximally over the ungual crest. An incision of the extensor tendon is made at its insertion on the ungual crest keeping the redundant epidermis proximal to this incision. The incision through the extensor tendon is continued deeper to the synovium of PII and PIII. Gentle traction in a palmar direction will disarticulate the joint space between PII and PIII. Incisions into the lateral and medial collateral ligaments from a cranio-dorsal origin in palmar direction further disarticulate the joint. Care must be exercised to preserve all epidermal tissue lying immediately adjacent to the collateral ligaments. Continual palmar traction will expose the base of PIII and the insertion of the flexor tendon. A dorsal incision is made into the flexor tendon in a palmar direction. Extreme palmar rotation of PIII will allow the dissection of the subcutaneous tissue of the pad from PIII. The redundant epidermal tissue will now cover the majority of the onychectomy site. No sutures or tissue adhesive are advised.

  13. Neural Networks: Implementations and Applications

    OpenAIRE

    Vonk, E.; Veelenturf, L.P.J.; Jain, L.C.

    1996-01-01

    Artificial neural networks, also called neural networks, have been used successfully in many fields including engineering, science and business. This paper presents the implementation of several neural network simulators and their applications in character recognition and other engineering areas

  14. Critical Branching Neural Networks

    Science.gov (United States)

    Kello, Christopher T.

    2013-01-01

    It is now well-established that intrinsic variations in human neural and behavioral activity tend to exhibit scaling laws in their fluctuations and distributions. The meaning of these scaling laws is an ongoing matter of debate between isolable causes versus pervasive causes. A spiking neural network model is presented that self-tunes to critical…

  15. Vocal behavior of Crested Guineafowl (Guttera edouardi) based on visual and sound playback surveys in the Umhlanga Lagoon Nature Reserve, KwaZulu-Natal province, South Africa

    Institute of Scientific and Technical Information of China (English)

    Johann H.van Niekerk

    2015-01-01

    Background:General y speaking, playbacks were often ineffective to determine the group sizes of birds since mainly males from leks responded. This limitation has not been tested properly for flocking birds such as Crested Guineafowl (Guttera edouardi) with the view to use it as a counting method. The aims of the study reported in this paper were (1) to describe the cal s of Crested Guineafowl in a social context;(2) to interpret cal s in an evolutionary context;and (3) to demonstrate that playbacks can be used to locate and count Crested Guineafowl in smal isolated forests. Methods:The vocal behavior of Crested Guineafowl was observed during a survey conducted in the Umhlanga Lagoon Nature Reserve (KwaZulu-Natal, South Africa) from November 2010 to June 2012. Transect line observations and sound playback methods were used. Results:The behavioral context and structure of cal s were described. The eight cal s described for Crested Guineafowl were produced mainly to unite flock members in the dense understory, where visibility was poor, and to repel intruders. When not disturbed, Crested Guineafowl were quiet and only made soft contact calls. Conclusions:The high rate of call back and the fact that flocks invariably approach the source of the call en masse, shows that field researchers are able to assess the population size of Crested Guineafowl with sound playbacks along a transect. The value of playbacks as a conservation tool is assessed.

  16. Cardiac potassium channel subtypes

    DEFF Research Database (Denmark)

    Schmitt, Nicole; Grunnet, Morten; Olesen, Søren-Peter

    2014-01-01

    About 10 distinct potassium channels in the heart are involved in shaping the action potential. Some of the K(+) channels are primarily responsible for early repolarization, whereas others drive late repolarization and still others are open throughout the cardiac cycle. Three main K(+) channels...... drive the late repolarization of the ventricle with some redundancy, and in atria this repolarization reserve is supplemented by the fairly atrial-specific KV1.5, Kir3, KCa, and K2P channels. The role of the latter two subtypes in atria is currently being clarified, and several findings indicate that...... they could constitute targets for new pharmacological treatment of atrial fibrillation. The interplay between the different K(+) channel subtypes in both atria and ventricle is dynamic, and a significant up- and downregulation occurs in disease states such as atrial fibrillation or heart failure. The...

  17. Trends in Cardiac Pacemaker Batteries

    Directory of Open Access Journals (Sweden)

    Venkateswara Sarma Mallela

    2004-10-01

    Full Text Available Batteries used in Implantable cardiac pacemakers-present unique challenges to their developers and manufacturers in terms of high levels of safety and reliability. In addition, the batteries must have longevity to avoid frequent replacements. Technological advances in leads/electrodes have reduced energy requirements by two orders of magnitude. Micro-electronics advances sharply reduce internal current drain concurrently decreasing size and increasing functionality, reliability, and longevity. It is reported that about 600,000 pacemakers are implanted each year worldwide and the total number of people with various types of implanted pacemaker has already crossed 3 million. A cardiac pacemaker uses half of its battery power for cardiac stimulation and the other half for housekeeping tasks such as monitoring and data logging. The first implanted cardiac pacemaker used nickel-cadmium rechargeable battery, later on zinc-mercury battery was developed and used which lasted for over 2 years. Lithium iodine battery invented and used by Wilson Greatbatch and his team in 1972 made the real impact to implantable cardiac pacemakers. This battery lasts for about 10 years and even today is the power source for many manufacturers of cardiac pacemakers. This paper briefly reviews various developments of battery technologies since the inception of cardiac pacemaker and presents the alternative to lithium iodine battery for the near future.

  18. Differentiation of Equine Mesenchymal Stromal Cells into Cells of Neural Lineage: Potential for Clinical Applications

    Directory of Open Access Journals (Sweden)

    Claudia Cruz Villagrán

    2014-01-01

    Full Text Available Mesenchymal stromal cells (MSCs are able to differentiate into extramesodermal lineages, including neurons. Positive outcomes were obtained after transplantation of neurally induced MSCs in laboratory animals after nerve injury, but this is unknown in horses. Our objectives were to test the ability of equine MSCs to differentiate into cells of neural lineage in vitro, to assess differences in morphology and lineage-specific protein expression, and to investigate if horse age and cell passage number affected the ability to achieve differentiation. Bone marrow-derived MSCs were obtained from young and adult horses. Following demonstration of stemness, MSCs were neurally induced and microscopically assessed at different time points. Results showed that commercially available nitrogen-coated tissue culture plates supported proliferation and differentiation. Morphological changes were immediate and all the cells displayed a neural crest-like cell phenotype. Expression of neural progenitor proteins, was assessed via western blot or immunofluorescence. In our study, MSCs generated from young and middle-aged horses did not show differences in their ability to undergo differentiation. The effect of cell passage number, however, is inconsistent and further experiments are needed. Ongoing work is aimed at transdifferentiating these cells into Schwann cells for transplantation into a peripheral nerve injury model in horses.

  19. Is neural Darwinism Darwinism?

    Science.gov (United States)

    van Belle, T

    1997-01-01

    Neural Darwinism is a theory of cognition developed by Gerald Edelman along with George Reeke and Olaf Sporns at Rockefeller University. As its name suggests, neural Darwinism is modeled after biological Darwinism, and its authors assert that the two processes are strongly analogous. both operate on variation in a population, amplifying the more adaptive individuals. However, from a computational perspective, neural Darwinism is quite different from other models of natural selection, such as genetic algorithms. The individuals of neural Darwinism do not replicate, thus robbing the process of the capacity to explore new solutions over time and ultimately reducing it to a random search. Because neural Darwinism does not have the computational power of a truly Darwinian process, it is misleading to label it as such. to illustrate this disparity in adaptive power, one of Edelman's early computer experiments, Darwin I, is revisited, and it is shown that adding replication greatly improves the adaptive power of the system. PMID:9090158

  20. Consciousness and neural plasticity

    DEFF Research Database (Denmark)

    consciousness is related to neural processes it seems, at least prima facie, that the ability of the neural structures to change should be reflected in a theory of this relationship "Neural plasticity" refers to the fact that the brain can change due to its own activity. The brain is not static but rather a...... relation between consciousness and brain functions. If consciousness is connected to specific brain structures (as a function or in identity) what happens to consciousness when those specific underlying structures change? It is therefore possible that the understanding and theories of neural plasticity can......, something that is stable over time. Considering neural plasticity, this is not necessarily so. The NCC might change and hence literally change the way a person is conscious. What it is about the NCC that can and might change is, even though it can be relevant for the relation between the brain and...

  1. Platelets and cardiac arrhythmia

    Directory of Open Access Journals (Sweden)

    JonasSDe Jong

    2010-12-01

    Full Text Available Sudden cardiac death remains one of the most prevalent modes of death in industrialized countries, and myocardial ischemia due to thrombotic coronary occlusion is its primary cause. The role of platelets in the occurrence of SCD extends beyond coronary flow impairment by clot formation. Here we review the substances released by platelets during clot formation and their arrhythmic properties. Platelet products are released from three types of platelet granules: dense core granules, alpha-granules, and platelet lysosomes. The physiologic properties of dense granule products are of special interest as a potential source of arrhythmic substances. They are released readily upon activation and contain high concentrations of serotonin, histamine, purines, pyrimidines, and ions such as calcium and magnesium. Potential arrhythmic mechanisms of these substances, e.g. serotonin and high energy phosphates, include induction of coronary constriction, calcium overloading, and induction of delayed after-depolarizations. Alpha-granules produce thromboxanes and other arachidonic acid products with many potential arrhythmic effects mediated by interference with cardiac sodium, calcium and potassium channels. Alpha-granules also contain hundreds of proteins that could potentially serve as ligands to receptors on cardiomyocytes. Lysosomal products probably do not have an important arrhythmic effect. Platelet products and ischemia can induce coronary permeability, thereby enhancing interaction with surrounding cardiomyocytes. Antiplatelet therapy is known to improve survival after myocardial infarction. Although an important part of this effect results from prevention of coronary clot formation, there is evidence to suggest that antiplatelet therapy also induces anti-arrhythmic effects during ischemia by preventing the release of platelet activation products.

  2. Metoclopramide-induced cardiac arrest

    Directory of Open Access Journals (Sweden)

    Martha M. Rumore

    2011-11-01

    Full Text Available The authors report a case of cardiac arrest in a patient receiving intravenous (IV metoclopramide and review the pertinent literature. A 62-year-old morbidly obese female admitted for a gastric sleeve procedure, developed cardiac arrest within one minute of receiving metoclopramide 10 mg via slow intravenous (IV injection. Bradycardia at 4 beats/min immediately appeared, progressing rapidly to asystole. Chest compressions restored vital function. Electrocardiogram (ECG revealed ST depression indicative of myocardial injury. Following intubation, the patient was transferred to the intensive care unit. Various cardiac dysrrhythmias including supraventricular tachycardia (SVT associated with hypertension and atrial fibrillation occurred. Following IV esmolol and metoprolol, the patient reverted to normal sinus rhythm. Repeat ECGs revealed ST depression resolution without pre-admission changes. Metoclopramide is a non-specific dopamine receptor antagonist. Seven cases of cardiac arrest and one of sinus arrest with metoclopramide were found in the literature. The metoclopramide prescribing information does not list precautions or adverse drug reactions (ADRs related to cardiac arrest. The reaction is not dose related but may relate to the IV administration route. Coronary artery disease was the sole risk factor identified. According to Naranjo, the association was possible. Other reports of cardiac arrest, severe bradycardia, and SVT were reviewed. In one case, five separate IV doses of 10 mg metoclopramide were immediately followed by asystole repeatedly. The mechanism(s underlying metoclopramide’s cardiac arrest-inducing effects is unknown. Structural similarities to procainamide may play a role. In view of eight previous cases of cardiac arrest from metoclopramide having been reported, further elucidation of this ADR and patient monitoring is needed. Our report should alert clinicians to monitor patients and remain diligent in surveillance and

  3. Cardiac perioperative complications in noncardiac surgery

    OpenAIRE

    Radovanović Dragana; Kolak Radmila; Stokić Aleksandar; Radovanović Zoran; Jovanović Gordana

    2008-01-01

    Anesthesiologists are confronted with an increasing population of patients undergoing noncardiac surgery who are at risk for cardiac complications in the perioperative period. Perioperative cardiac complications are responsible for significant mortality and morbidity. The aim of the present study was to determine the incidence of perioperative (operative and postoperative) cardiac complications and correlations between the incidence of perioperative cardiac complications and type of surgical ...

  4. Epigenetic regulation in cardiac fibrosis

    Institute of Scientific and Technical Information of China (English)

    Li-Ming; Yu; Yong; Xu

    2015-01-01

    Cardiac fibrosis represents an adoptive response in the heart exposed to various stress cues. While resolution of the fibrogenic response heralds normalization of heart function, persistent fibrogenesis is usually associated with progressive loss of heart function and eventually heart failure. Cardiac fibrosis is regulated by a myriad of factors that converge on the transcription of genes encoding extracellular matrix proteins, a process the epigenetic machinery plays a pivotal role. In this minireview, we summarize recent advances regarding the epigenetic regulation of cardiac fibrosis focusing on the role of histone and DNA modifications and non-coding RNAs.

  5. Cardiac catheterization and angiography. Third edition

    International Nuclear Information System (INIS)

    This book discusses the papers on cardiac catheterization and angiography. The topics covered are: historical perspective and present practice of cardiac catheterization; angiography principles and utilization of radiologic and cineangiographic equipment; complications, incidence and prevention of side effects of cardiac catheterization; techniques; blood flow measurement of heart; pressure measurement; diagnostic techniques of angiography; special catheter techniques; coronary angiography, temporary and permanent pacemakers, potential role of lasers in the cardiac catheterization and evaluation of cardiac function

  6. Antifibrotic therapies to control cardiac fibrosis

    OpenAIRE

    Fan, Zhaobo; Guan, Jianjun

    2016-01-01

    Cardiac fibrosis occurs naturally after myocardial infarction. While the initially formed fibrotic tissue prevents the infarcted heart tissue from rupture, the progression of cardiac fibrosis continuously expands the size of fibrotic tissue and causes cardiac function decrease. Cardiac fibrosis eventually evolves the infarcted hearts into heart failure. Inhibiting cardiac fibrosis from progressing is critical to prevent heart failure. However, there is no efficient therapeutic approach curren...

  7. Dynamics of neural cryptography

    International Nuclear Information System (INIS)

    Synchronization of neural networks has been used for public channel protocols in cryptography. In the case of tree parity machines the dynamics of both bidirectional synchronization and unidirectional learning is driven by attractive and repulsive stochastic forces. Thus it can be described well by a random walk model for the overlap between participating neural networks. For that purpose transition probabilities and scaling laws for the step sizes are derived analytically. Both these calculations as well as numerical simulations show that bidirectional interaction leads to full synchronization on average. In contrast, successful learning is only possible by means of fluctuations. Consequently, synchronization is much faster than learning, which is essential for the security of the neural key-exchange protocol. However, this qualitative difference between bidirectional and unidirectional interaction vanishes if tree parity machines with more than three hidden units are used, so that those neural networks are not suitable for neural cryptography. In addition, the effective number of keys which can be generated by the neural key-exchange protocol is calculated using the entropy of the weight distribution. As this quantity increases exponentially with the system size, brute-force attacks on neural cryptography can easily be made unfeasible

  8. Robotic Applications in Cardiac Surgery

    Directory of Open Access Journals (Sweden)

    Alan P. Kypson

    2008-11-01

    Full Text Available Traditionally, cardiac surgery has been performed through a median sternotomy, which allows the surgeon generous access to the heart and surrounding great vessels. As a paradigm shift in the size and location of incisions occurs in cardiac surgery, new methods have been developed to allow the surgeon the same amount of dexterity and accessibility to the heart in confined spaces and in a less invasive manner. Initially, long instruments without pivot points were used, however, more recent robotic telemanipulation systems have been applied that allow for improved dexterity, enabling the surgeon to perform cardiac surgery from a distance not previously possible. In this rapidly evolving field, we review the recent history and clinical results of using robotics in cardiac surgery.

  9. Cardiac manifestations in systemic sclerosis

    Institute of Scientific and Technical Information of China (English)

    Sevdalina; Lambova

    2014-01-01

    Primary cardiac involvement, which develops as a direct consequence of systemic sclerosis(SSc), may manifest as myocardial damage, fibrosis of the conduction system, pericardial and, less frequently, as valvular disease. In addition, cardiac complications in SSc may develop as a secondary phenomenon due to pulmonary arterial hypertension and kidney pathology. The prevalence of primary cardiac involvement in SSc is variable and difficult to determine because of the diversity of cardiac manifestations, the presence of subclinical periods, the type of diagnostic tools applied, and the diversity of patient populations. When clinically manifested, cardiac involvement is thought to be an important prognostic factor. Profound microvascular disease is a pathognomonic feature of SSc, as both vasospasm and structural alterations are present. Such alterations are thought to predict macrovascular atherosclerosis over time. There are contradictory reports regarding the prevalence of atherosclerosis in SSc. According to some authors, the prevalence of atherosclerosis of the large epicardial coronary arteries is similar to that of the general population, in contrast with other rheumatic diseases such as rheumatoid arthritis and systemic lupus erythematosus. However, the level of inflammation in SSc is inferior. Thus, the atherosclerotic process may not be as aggressive and not easily detectable in smaller studies. Echocardiography(especially tissue Doppler imaging), single-photon emission computed tomography, magnetic resonance imaging and cardiac computed tomography are sensitive techniques for earlier detection of both structural and functional scleroderma-related cardiac pathologies. Screening for subclinical cardiac involvement via modern, sensitive tools provides an opportunity for early diagnosis and treatment, which is of crucial importance for a positive outcome.

  10. Computational Modeling of Cardiac Electromechanics

    OpenAIRE

    Krishnamoorthi, Shankarjee

    2013-01-01

    Cardiac arrhythmias are a leading cause of death worldwide. Notably, the electrophysiologiy and microstructural requirements for a fatal ventricular arrhythmia remain incompletely understood, thereby the treatment remains largely empirical. Standard antiarrhythmic drug therapy has failed to reduce, and in some instances has increased, the incidence of Sudden Cardiac Death (SCD). Hence, a more complete understanding of the mechanisms that foment a fatal arrhythmia is needed and computational m...

  11. Cardiac Biomarkers in Hyperthyroid Cats

    OpenAIRE

    Sangster, Jodi Kirsten

    2013-01-01

    Background: Hyperthyroidism has substantial effects on the circulatory system. The cardiac biomarkers NT-proBNP and troponin I (cTNI) have proven useful in identifying cats with myocardial disease but have not been as extensively investigated in hyperthyroidism.Hypothesis: Plasma NT-proBNP and cTNI concentrations are higher in cats with primary cardiac disease than in cats with hyperthyroidism and higher in cats with hyperthyroidism than in healthy control cats.Animals: Twenty-three hyperthyr...

  12. Current trends in cardiac rehabilitation

    OpenAIRE

    Dafoe, W; Huston, P

    1997-01-01

    Cardiac rehabilitation can reduce mortality and morbidity for patients with many types of cardiac disease cost-effectively, yet is generally underutilized. Rehabilitation is helpful not only for patients who have had a myocardial infarction but also for those with stable angina or congestive heart failure or those who have undergone myocardial revascularization procedures, a heart transplant or heart valve surgery. The beneficial effects of rehabilitation include a reduction in the rate of de...

  13. An overview of cardiac morphogenesis.

    OpenAIRE

    Schleich, Jean-Marc; Abdulla, Tariq; Summers, Ron; Houyel, Lucile

    2013-01-01

    International audience Accurate knowledge of normal cardiac development is essential for properly understanding the morphogenesis of congenital cardiac malformations that represent the most common congenital anomaly in newborns. The heart is the first organ to function during embryonic development and is fully formed at 8 weeks of gestation. Recent studies stemming from molecular genetics have allowed specification of the role of cellular precursors in the field of heart development. In th...

  14. Gastrointestinal Complications and Cardiac Surgery

    OpenAIRE

    Allen, Sara J.

    2014-01-01

    Gastrointestinal (GI) complications are an uncommon but potentially devastating complication of cardiac surgery. The reported incidence varies between .3% and 5.5% with an associated mortality of .3–87%. A wide range of GI complications are reported with bleeding, mesenteric ischemia, pancreatitis, cholecystitis, and ileus the most common. Ischemia is thought to be the main cause of GI complications with hypoperfusion during cardiac surgery as well as systemic inflammation, hypothermia, drug ...

  15. Cardiac abnormalities after subarachnoid hemorrhage

    OpenAIRE

    Bilt, I.A.C. van der

    2016-01-01

    Aneurysmal subarachnoid hemorrhage(aSAH) is a devastating neurological disease. During the course of the aSAH several neurological and medical complications may occur. Cardiac abnormalities after aSAH are observed often and resemble stress cardiomyopathy or Tako-tsubo cardiomyopathy(Broken Heart Syndrome) that has been described after acute stress. It is a reversible cardiac dysfunction with distinct imaging features(the echocardiographic or left ventricular angiographic image resembles a Tak...

  16. ANT Advanced Neural Tool

    International Nuclear Information System (INIS)

    This paper describes a practical introduction to the use of Artificial Neural Networks. Artificial Neural Nets are often used as an alternative to the traditional symbolic manipulation and first order logic used in Artificial Intelligence, due the high degree of difficulty to solve problems that can not be handled by programmers using algorithmic strategies. As a particular case of Neural Net a Multilayer Perception developed by programming in C language on OS9 real time operating system is presented. A detailed description about the program structure and practical use are included. Finally, several application examples that have been treated with the tool are presented, and some suggestions about hardware implementations. (Author) 15 refs

  17. ANT Advanced Neural Tool

    Energy Technology Data Exchange (ETDEWEB)

    Labrador, I.; Carrasco, R.; Martinez, L.

    1996-07-01

    This paper describes a practical introduction to the use of Artificial Neural Networks. Artificial Neural Nets are often used as an alternative to the traditional symbolic manipulation and first order logic used in Artificial Intelligence, due the high degree of difficulty to solve problems that can not be handled by programmers using algorithmic strategies. As a particular case of Neural Net a Multilayer Perception developed by programming in C language on OS9 real time operating system is presented. A detailed description about the program structure and practical use are included. Finally, several application examples that have been treated with the tool are presented, and some suggestions about hardware implementations. (Author) 15 refs.

  18. AUV fuzzy neural BDI

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    The typical BDI (belief desire intention) model of agent is not efficiently computable and the strict logic expression is not easily applicable to the AUV (autonomous underwater vehicle) domain with uncertainties. In this paper, an AUV fuzzy neural BDI model is proposed. The model is a fuzzy neural network composed of five layers: input ( beliefs and desires) , fuzzification, commitment, fuzzy intention, and defuzzification layer. In the model, the fuzzy commitment rules and neural network are combined to form intentions from beliefs and desires. The model is demonstrated by solving PEG (pursuit-evasion game), and the simulation result is satisfactory.

  19. FGF21 and cardiac physiopathology

    Directory of Open Access Journals (Sweden)

    Anna ePlanavila

    2015-08-01

    Full Text Available The heart is not traditionally considered either a target or a site of fibroblast growth factor-21 (FGF21 production. However, recent findings indicate that FGF21 can act as a cardiomyokine; that is, it is produced by cardiac cells at significant levels and acts in an autocrine manner on the heart itself. The heart is sensitive to the effects of FGF21, both systemic and locally generated, owing to the expression in cardiomyocytes of β-Klotho, the key co-receptor known to confer specific responsiveness to FGF21 action. FGF21 has been demonstrated to protect against cardiac hypertrophy, cardiac inflammation, and oxidative stress. FGF21 expression in the heart is induced in response to cardiac insults, such as experimental cardiac hypertrophy and myocardial infarction in rodents, as well as in failing human hearts. Intracellular mechanisms involving PPARα and Sirt1 mediate transcriptional regulation of the FGF21 gene in response to exogenous stimuli. In humans, circulating FGF21 levels are elevated in coronary heart disease and atherosclerosis, and are associated with a higher risk of cardiovascular events in patients with type 2 diabetes. These findings provide new insights into the role of FGF21 in the heart and may offer potential therapeutic strategies for cardiac disease.

  20. Physiological and pathological cardiac hypertrophy.

    Science.gov (United States)

    Shimizu, Ippei; Minamino, Tohru

    2016-08-01

    The heart must continuously pump blood to supply the body with oxygen and nutrients. To maintain the high energy consumption required by this role, the heart is equipped with multiple complex biological systems that allow adaptation to changes of systemic demand. The processes of growth (hypertrophy), angiogenesis, and metabolic plasticity are critically involved in maintenance of cardiac homeostasis. Cardiac hypertrophy is classified as physiological when it is associated with normal cardiac function or as pathological when associated with cardiac dysfunction. Physiological hypertrophy of the heart occurs in response to normal growth of children or during pregnancy, as well as in athletes. In contrast, pathological hypertrophy is induced by factors such as prolonged and abnormal hemodynamic stress, due to hypertension, myocardial infarction etc. Pathological hypertrophy is associated with fibrosis, capillary rarefaction, increased production of pro-inflammatory cytokines, and cellular dysfunction (impairment of signaling, suppression of autophagy, and abnormal cardiomyocyte/non-cardiomyocyte interactions), as well as undesirable epigenetic changes, with these complex responses leading to maladaptive cardiac remodeling and heart failure. This review describes the key molecules and cellular responses involved in physiological/pathological cardiac hypertrophy. PMID:27262674

  1. Cardiac MRI in suspected myocarditis

    International Nuclear Information System (INIS)

    Purpose: To evaluate the potential of ECG-gated breath-hold MRI in diagnosing acute myocardidits. Material and methods: Cardiac MRI was performed on 21 consecutive patients with suspected myocarditis. ECG-gated breath-hold T2-weighted images with fat suppression were acquired in 3 standard views. T1-weighted imaging (FLASH) was performed 10 min after IV administration of Gd-DTPA. Laboratory data included creatine kinase, troponin T and serological tests, ECG findings and echocardiography. Imaging findings were retrospectively compared to the discharge diagnoses. Signal alterations were semiquantitatively classified. Results: Acute myocarditis was diagnosed in 9 patients and cardiac sarcoidosis in 2 patients. Late enhancement was observed in 4 patients with acute myocarditis and in both patients with cardiac sarcoidosis. Semiquantitative evaluation revealed 9 true positive, 9 true negative, 1 false positive and 2 false negative results. Conclusion: Cardiac MRI has the potential to detect acute myocarditis and to diagnose cardiac sarcoidosis. Late enhancement of Gd-DTPA can be found in both viral myocarditis and cardiac sarcoidosis. (orig.)

  2. Cardiac imaging. A multimodality approach

    International Nuclear Information System (INIS)

    An excellent atlas on modern diagnostic imaging of the heart Written by an interdisciplinary team of experts, Cardiac Imaging: A Multimodality Approach features an in-depth introduction to all current imaging modalities for the diagnostic assessment of the heart as well as a clinical overview of cardiac diseases and main indications for cardiac imaging. With a particular emphasis on CT and MRI, the first part of the atlas also covers conventional radiography, echocardiography, angiography and nuclear medicine imaging. Leading specialists demonstrate the latest advances in the field, and compare the strengths and weaknesses of each modality. The book's second part features clinical chapters on heart defects, endocarditis, coronary heart disease, cardiomyopathies, myocarditis, cardiac tumors, pericardial diseases, pulmonary vascular diseases, and diseases of the thoracic aorta. The authors address anatomy, pathophysiology, and clinical features, and evaluate the various diagnostic options. Key features: - Highly regarded experts in cardiology and radiology off er image-based teaching of the latest techniques - Readers learn how to decide which modality to use for which indication - Visually highlighted tables and essential points allow for easy navigation through the text - More than 600 outstanding images show up-to-date technology and current imaging protocols Cardiac Imaging: A Multimodality Approach is a must-have desk reference for cardiologists and radiologists in practice, as well as a study guide for residents in both fields. It will also appeal to cardiac surgeons, general practitioners, and medical physicists with a special interest in imaging of the heart. (orig.)

  3. Cardiac involvement in myotonic dystrophy

    DEFF Research Database (Denmark)

    Lund, Marie; Diaz, Lars Jorge; Ranthe, Mattis Flyvholm;

    2014-01-01

    genetic testing for DM1. Information on incident cardiac diseases was obtained from the NPR. We estimated standardized incidence ratios (SIRs) of cardiac disease compared with the background population, overall and according to selected diagnostic subgroups (cardiomyopathy, heart failure, conduction...... disorders, arrhythmias, and device implantation). In the DM cohort, SIR for any cardiac disease was 3.42 [95% confidence interval (CI) 3.01-3.86]; for a cardiac disease belonging to the selected subgroups 6.91 (95% CI: 5.93-8.01) and for other cardiac disease 2.59 (95% CI: 2.03-3.25). For a cardiac disease...... belonging to the selected subgroups, the risk was particularly high in the first year after DM diagnosis [SIR 15.4 (95% CI: 10.9-21.3)] but remained significantly elevated in subsequent years [SIR 6.07 (95% CI: 5.11-7.16]). The risk was higher in young cohort members [e.g. 20-39 years: SIR 18.1 (95% CI: 12...

  4. Cardiac stunning in the clinic: the full picture.

    Science.gov (United States)

    Pomblum, Valdeci J; Korbmacher, Bernhard; Cleveland, Sinclair; Sunderdiek, Ullrich; Klocke, Rainhard C; Schipke, Jochen D

    2010-01-01

    Cardiac stunning refers to different dysfunctional levels occurring after an episode of acute ischemia, despite blood flow is near normal or normal. The phenomenon was initially identified in animal models, where it has been very well characterized. After being established in the experimental setting, it remained unclear, whether a similar syndrome occurs in humans. In addition, it remained controversial, whether stunning was of any clinical relevance as it is spontaneously reversible. Hence, many studies continue to focus on the properties and mechanisms of stunning, although therapies seem more relevant for attenuating and treating myocardial ischemia/reperfusion (I/R) injury, i.e. to bridge until recovery. This article reviews the different facets of cardiac stunning, i.e. myocardial, vascular/microvascular/endothelial, metabolic, neural/neuronal, and electrical stunning. This review also displays where these facets exist and which clinical relevance they might have. Particular attention is directed to the different therapeutic interventions that the various facets of this I/R-induced cardiac injury might require. A final outlook considers possible alternatives to further reduce the detrimental consequences of brief episodes of ischemia and reperfusion. PMID:19773228

  5. Ticks on crested francolins, Francolinus sephaena, and on the vegetation on a farm in Limpopo Province, South Africa : research communication

    Directory of Open Access Journals (Sweden)

    A.C. Uys

    2005-09-01

    Full Text Available Ticks were collected at approximately bi-monthly intervals between June 1996 and June 1997 from crested francolins, Francolinus sephaena, and from the vegetation on a mixed cattle and wildlife farm in Limpopo Province, South Africa. The birds were infested with the immature stages of 13 tick species, of which Amblyomma hebraeum, Amblyomma marmoreum and Hyalomma marginatumrufipes were the most numerous and prevalent. Ten ixodid tick species were collected from the vegetation, of which the immature stages of Rhipicephalus appendiculatus, Rhipicephalus (Boophilus decoloratus and Rhipicephalus evertsi evertsi were the most numerous. No adult ticks were collected from the birds and only two from the vegetation. The restricted home range of crested francolins implies that they could serve as a source of tick infestation only for other animals within the same habitat as the birds.

  6. Association of Total Electron Content (TEC and foF2 variations with earthquake events at the anomaly crest region

    Directory of Open Access Journals (Sweden)

    A. Depueva

    2004-06-01

    Full Text Available The paper attempts to identify ionospheric parameters in association with earthquake at anomaly crest station through VHF Radio Beacon data and ground based ionosonde measurements while the Total Electron Content(TEC parameters from RB observations are based mainly on data taken over Guwahati (26.2°N, 91.75° E, foF2 data used in the analysis were collected at Ahmadabad (23.01°N, 72.36°E. The paper describes methods and techniques adopted to examine modifications on these parameters if any, due to earthquake preparatory processes at equatorial anomaly crest stations. The mechanism of inducement of density changes in the ionosphere is sought through the generation of strong fountain effect possibly by the development of electric field during the earthquake preparatory process.

  7. Levee crest elevation profiles derived from airborne lidar-based high resolution digital elevation models in south Louisiana

    Science.gov (United States)

    Palaseanu-Lovejoy, Monica; Thatcher, Cindy A.; Barras, John A.

    2014-01-01

    This study explores the feasibility of using airborne lidar surveys to derive high-resolution digital elevation models (DEMs) and develop an automated procedure to extract levee longitudinal elevation profiles for both federal levees in Atchafalaya Basin and local levees in Lafourche Parish. Generally, the use of traditional manual surveying methods to map levees is a costly and time consuming process that typically produces cross-levee profiles every few hundred meters, at best. The purpose of our paper is to describe and test methods for extracting levee crest elevations in an efficient, comprehensive manner using high resolution lidar generated DEMs. In addition, the vertical uncertainty in the elevation data and its effect on the resultant estimate of levee crest heights is addressed in an assessment of whether the federal levees in our study meet the USACE minimum height design criteria.

  8. A comparative analysis of double-crested cormorant diets from stomachs and pellets from two Lake Ontario colonies

    Science.gov (United States)

    Johnson, James H.; Ross, Robert M.; McCullough, Russell D.; Mathers, Alastair

    2010-01-01

    Double-crested cormorant (Phalacrocorax auritus) diets were compared with evidence from the stomachs of shot birds and from regurgitated pellets at High Bluff Island and Little Galloo Island, Lake Ontario. The highest similarity in diets determined by stomach and pellet analyses occurred when both samples were collected on the same day. Diet overlap dropped substantially between the two methods when collection periods were seven to ten days apart, which suggested differences in prey availability between the two periods. Since the average number of fish recovered in pellets was significantly higher than that in stomachs, use of pellets to determine fish consumption of double-crested cormorants may be more valid than stomach analysis because pellet content represent an integrated sampling of food consumed over approximately 24 hours.

  9. Convolutional Neural Network Based Fault Detection for Rotating Machinery

    Science.gov (United States)

    Janssens, Olivier; Slavkovikj, Viktor; Vervisch, Bram; Stockman, Kurt; Loccufier, Mia; Verstockt, Steven; Van de Walle, Rik; Van Hoecke, Sofie

    2016-09-01

    Vibration analysis is a well-established technique for condition monitoring of rotating machines as the vibration patterns differ depending on the fault or machine condition. Currently, mainly manually-engineered features, such as the ball pass frequencies of the raceway, RMS, kurtosis an crest, are used for automatic fault detection. Unfortunately, engineering and interpreting such features requires a significant level of human expertise. To enable non-experts in vibration analysis to perform condition monitoring, the overhead of feature engineering for specific faults needs to be reduced as much as possible. Therefore, in this article we propose a feature learning model for condition monitoring based on convolutional neural networks. The goal of this approach is to autonomously learn useful features for bearing fault detection from the data itself. Several types of bearing faults such as outer-raceway faults and lubrication degradation are considered, but also healthy bearings and rotor imbalance are included. For each condition, several bearings are tested to ensure generalization of the fault-detection system. Furthermore, the feature-learning based approach is compared to a feature-engineering based approach using the same data to objectively quantify their performance. The results indicate that the feature-learning system, based on convolutional neural networks, significantly outperforms the classical feature-engineering based approach which uses manually engineered features and a random forest classifier. The former achieves an accuracy of 93.61 percent and the latter an accuracy of 87.25 percent.

  10. An Assessment of Breeding Great Blue Herons and the Impact of Double-Crested Cormorants in the Shad Island Rookery, Swanton Vermont 2001

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Concern about the effects of invading Double-crested Cormorants on Lake Champlain has prompted investigations in the Great Blue Heron rookery on Shad Island,...

  11. Development and Pilot Evaluation of Native CREST – a Cancer Research Experience and Student Training Program for Navajo Undergraduate Students

    OpenAIRE

    Hughes, Christine A; Bauer, Mark C.; Horazdovsky, Bruce F.; Garrison, Edward R.; Patten, Christi A.; Petersen, Wesley O.; Bowman, Clarissa N.; Vierkant, Robert A.

    2013-01-01

    The Mayo Clinic Cancer Center and Diné College received funding for a 4-year collaborative P20 planning grant from the National Cancer Institute in 2006. The goal of the partnership was to increase Navajo undergraduates’ interest in and commitment to biomedical coursework and careers, especially in cancer research. This paper describes the development, pilot testing and evaluation of Native CREST (Cancer Research Experience & Student Training), a 10-week cancer research training program provi...

  12. Unilateral evisceration of an eye following cornea and lens perforation in a sulfur-crested cockatoo (Cacatua galerita)

    OpenAIRE

    CHRISTEN, C.; Richter, M.; Fischer, I.; Eule, C; Spiess, B M; Hatt, J M

    2006-01-01

    A 24-year old male sulfur-crested Cockatoo (Cacatua galerita) was presented with a subacute perforation of the cornea without involvement of the lens.The bird was treated conservatively and the eye remained quiescent up to a second traumatic corneal perforation associated with a lens capsule rupture 15 months later. Due to the second perforating trauma of an already blind eye involving the lens, evisceration of the eye was performed. Two months after surgery the cosmetic result was excellent....

  13. The Numerical Solution of Nekrasov's Equation in the Boundary Layer near the Crest, for Waves near the Maximum Height

    OpenAIRE

    Byatt-Smith, J. G.

    2000-01-01

    Nekrasov's integral equation describing water waves of permanent form, determines the angle phi that the wave surface makes with the horizontal. The independent variable s is a suitably scaled velocity potential, evaluated at the free surface, with the origin corresponding to the crest of the wave. For all waves, except for amplitudes near the maximum, phi satisfies the inequality mod(phi) is less than pi/6. It has been shown numerically and analytically, that as the wave amplitude approaches...

  14. Molecular detection of bacteria in the families Rickettsiaceae and Anaplasmataceae in northern crested caracaras (Caracara cheriway).

    Science.gov (United States)

    Erwin, John A; Fitak, Robert R; Dwyer, James F; Morrison, Joan L; Culver, Melanie

    2016-04-01

    Bacterial pathogens of the families Anaplasmataceae and Rickettsiaceae are often spread to humans or other animals from bites from infected arthropod hosts. Recently, an increasing number of studies have implicated migratory birds in the circulation of these pathogens through the spread of arthropod vectors. However, few studies have examined the potential for resident bird populations to serve as reservoirs for these zoonoses. In this study, we used nested PCRs of the GroESL and 17kDa genes to screen for Anaplasmataceae and Rickettsiaceae, respectively, in a resident population of the northern crested caracara (Caracara cheriway) from Florida (n=55). Additionally, a small number (n=6) of captive individuals from Texas were included. We identified one individual (1.64%) positive for Rickettsia felis and one (1.64%) positive for Ehrlichia chaffeensis; both these individuals were from Florida. Presence of these pathogens demonstrates that these birds are potential hosts; however, the low prevalence of infections suggests that these populations likely do not function as an ecological reservoir. PMID:26837860

  15. Multi-frequency simultaneous measurement of bioimpedance spectroscopy based on a low crest factor multisine excitation

    International Nuclear Information System (INIS)

    Bioimpedance spectroscopy (BIS) is becoming a powerful diagnostic tool for a wide variety of medical applications, and the multi-frequency simultaneous (MFS) measurement of BIS can greatly reduce measurement time and record the transient physiological status of a living body compared with traditional frequency-sweep measurement technology. This paper adopts the Van der Ouderaa’s multisine, which has 31 equidistant and flat amplitude spectra and a low crest factor of 1.405 as the broadband excitation, and realizes the MFS measurement of BIS by means of spectral analysis using the fast Fourier transform algorithm. The approach to implement the multisine based on a field-programmable gate array and a digital to analog converter is described in detail, and impedance measurement experiments are performed on three resistance-capitance three-element phantoms. Experimental results show a commendable accuracy with a mean relative error of 0.55% for the impedance amplitudes, and a mean absolute error of 0.20° for the impedance phases on the 31 frequencies ranging linearly from 32 to 992 kHz. This paper validates the feasibility of the MFS technology for BIS measurement based on the multisine excitation. (paper)

  16. Multi-frequency simultaneous measurement of bioimpedance spectroscopy based on a low crest factor multisine excitation.

    Science.gov (United States)

    Yang, Yuxiang; Zhang, Fu; Tao, Kun; Wang, Lianhuan; Wen, He; Teng, Zhaosheng

    2015-03-01

    Bioimpedance spectroscopy (BIS) is becoming a powerful diagnostic tool for a wide variety of medical applications, and the multi-frequency simultaneous (MFS) measurement of BIS can greatly reduce measurement time and record the transient physiological status of a living body compared with traditional frequency-sweep measurement technology. This paper adopts the Van der Ouderaa's multisine, which has 31 equidistant and flat amplitude spectra and a low crest factor of 1.405 as the broadband excitation, and realizes the MFS measurement of BIS by means of spectral analysis using the fast Fourier transform algorithm. The approach to implement the multisine based on a field-programmable gate array and a digital to analog converter is described in detail, and impedance measurement experiments are performed on three resistance-capitance three-element phantoms. Experimental results show a commendable accuracy with a mean relative error of 0.55% for the impedance amplitudes, and a mean absolute error of 0.20° for the impedance phases on the 31 frequencies ranging linearly from 32 to 992 kHz. This paper validates the feasibility of the MFS technology for BIS measurement based on the multisine excitation. PMID:25679488

  17. Molecular detection of bacteria in the families Rickettsiaceae and Anaplasmataceae in northern crested caracaras (Caracara cheriway)

    Science.gov (United States)

    Erwin, John A.; Fitak, Robert R.; Dwyer, James F.; Morrison, Joan L.; Culver, Melanie

    2016-01-01

    Bacterial pathogens of the families Anaplasmataceae and Rickettsiaceae are often spread to humans or other animals from bites from infected arthropod hosts. Recently, an increasing number of studies have implicated migratory birds in the circulation of these pathogens through the spread of arthropod vectors. However, few studies have examined the potential for resident bird populations to serve as reservoirs for these zoonoses. In this study, we used nested PCRs of the GroESL and 17 kDa genes to screen for Anaplasmataceae and Rickettsiaceae, respectively, in a resident population of the northern crested caracara (Caracara cheriway) from Florida (n = 55). Additionally, a small number (n = 6) of captive individuals from Texas were included. We identified one individual (1.64%) positive for Rickettsia felis and one (1.64%) positive for Ehrlichia chaffeensis; both these individuals were from Florida. Presence of these pathogens demonstrates that these birds are potential hosts; however, the low prevalence of infections suggests that these populations likely do not function as an ecological reservoir.

  18. CREST : a computer program for the calculation of composition dependent self-shielded cross-sections

    International Nuclear Information System (INIS)

    A computer program CREST for the calculation of the composition and temperature dependent self-shielded cross-sections using the shielding factor approach has been described. The code includes the editing and formation of the data library, calculation of the effective shielding factors and cross-sections, a fundamental mode calculation to generate the neutron spectrum for the system which is further used to calculate the effective elastic removal cross-sections. Studies to explore the sensitivity of reactor parameters to changes in group cross-sections can also be carried out by using the facility available in the code to temporarily change the desired constants. The final self-shielded and transport corrected group cross-sections can be dumped on cards or magnetic tape in a suitable form for their direct use in a transport or diffusion theory code for detailed reactor calculations. The program is written in FORTRAN and can be accommodated in a computer with 32 K work memory. The input preparation details, sample problem and the listing of the program are given. (author)

  19. Immunohistochemical and morphological features of a small bowel leiomyoma in a black crested macaque (Macaca nigra

    Directory of Open Access Journals (Sweden)

    Aristizabal-Arbelaez Mónica

    2012-06-01

    Full Text Available Abstract Background Spontaneous gastrointestinal neoplasms in non-human primates are commonly seen in aged individuals. Due to genetic similarities between human and non-human primates, scientists have shown increasing interest in terms of comparative oncology studies. Case presentation The present study is related to a case of an intestinal leiomyoma in a black crested macaque (Macaca nigra, kept on captivity by Matecaña Zoo, Pereira City, Colombia. The animal had abdominal distension, anorexia, vomiting, diarrhea and behavioral changes. Clinical examination showed an increased volume in the upper right abdominal quadrant caused by a neoplastic mass. The patient died during the surgical procedure. Necropsy revealed several small nodules in the peritoneum with adhesion to different portions of the small and large intestines, liver, stomach and diaphragm. Tissue samples were collected, routinely processed and stained by H&E. Microscopic examination revealed a mesenchymal tumor limited to tunica muscularis, resembling normal smooth muscle cells. Neoplastic cells were positive for alpha-smooth muscle actin and vimentin, and negative for cytokeratin AE1/AE3 by immunohistochemistry. Those morphological and immunohistochemical findings allowed to diagnose the intestinal leiomyoma referred above. Conclusion Neoplastic diseases in primates have multifaceted causes. Their manifestations are understudied, leading to a greater difficulty in detection and measurement of the real impact provides by this disease.

  20. Fast tool for evaluation of iliac crest tissue elastic properties using the reduced-basis methods.

    Science.gov (United States)

    Lee, Taeyong; Garlapati, Revanth Reddy; Lam, Kathy; Lee, Peter Vee Sin; Chung, Yoon-Sok; Choi, Jae Bong; Vincent, Tan Beng Chye; Das De, Shamal

    2010-12-01

    Computationally expensive finite element (FE) methods are generally used for indirect evaluation of tissue mechanical properties of trabecular specimens, which is vital for fracture risk prediction in the elderly. This work presents the application of reduced-basis (RB) methods for rapid evaluation of simulation results. Three cylindrical transiliac crest specimens (diameter: 7.5 mm, length: 10-12 mm) were obtained from healthy subjects (20 year-old, 22 year-old, and 24 year-old females) and scanned using microcomputed tomography imaging. Cubic samples of dimensions 5×5×5 mm(3) were extracted from the core of the cylindrical specimens for FE analysis. Subsequently, a FE solution library (test space) was constructed for each of the specimens by varying the material property parameters: tissue elastic modulus and Poisson's ratio, to develop RB algorithms. The computational speed gain obtained by the RB methods and their accuracy relative to the FE analysis were evaluated. Speed gains greater than 4000 times, were obtained for all three specimens for a loss in accuracy of less than 1% in the maxima of von-Mises stress with respect to the FE-based value. The computational time decreased from more than 6 h to less than 18 s. RB algorithms can be successfully utilized for real-time reliable evaluation of trabecular bone elastic properties. PMID:21142323

  1. Evaluation of sloshing wave crest impact pressure acting on a fixed roof cylindrical tank

    International Nuclear Information System (INIS)

    This report describes the applicability of a newly developed computer code SLOSH-3D on estimating of sloshing wave crest impact pressure acting on a fixed roof of cylindrical tank. Based on the computed results, slosh-induced pressure loads and distribution on the tank roof is presented. A large shaking table test conducted on the E-Defense shaking table by a joint study group, composed of some electric companies, has been analyzed. In the shaking table test, partially water-filled cylindrical tank (diameter: 3m, height: 3m, water depth: 2.3m or 1.9m) with a flat fixed roof was subjected to a sinusoidal excitation at the first sloshing resonant frequency. The computer code well simulated the observed waveform with a spiky rising large pressure at the time of liquid impact on the tank wall, including appearance of negative pressures in the post impact period, with sufficient accuracy. As for the liquid impact zone of the tank roof including the water splash phenomena, the numerical computations indicated good agreement with the observed results. Furthermore, the numerical computations provided the total pressure load and pressure distribution on the tank wall at an instant of time when maximum pressure peak occurs. Consequently, the computer code SLOSH-3D was capable of predicting the complex nonlinear sloshing behavior with the collision of the liquid surface against the thank roof with an acceptable level of accuracy. (author)

  2. URANS simulations of ship motion responses in long-crest irregular waves

    Institute of Scientific and Technical Information of China (English)

    沈志荣; 叶海轩; 万德成

    2014-01-01

    In this paper, numerical prediction of ship motion responses in long-crest irregular waves by the URANS-VOF method is presented. A white noise spectrum is applied to generate the incoming waves to evaluate the motion responses. The procedure can replace a decade of simulations in regular wave with one single run to obtain a complete curve of linear motion response, conside-rably reducing computation time. A correction procedure is employed to adjust the wave generation signal based on the wave spe-ctrum and achieves fairly better results in the wave tank. Three ship models with five wave conditions are introduced to validate the method. The computations in this paper are completed by using the solver naoe-FOAM-SJTU, a solver developed for ship and ocean engineering based on the open source code OpenFOAM. The computational motion responses by the irregular wave procedure are compared with the results by regular wave, experiments and strip theory. Transfer functions by irregular wave closely agree with the data obtained in the regular waves, showing negligible difference. The comparison between computational results and experiments also show good agreements. The results better predicted by CFD method than strip theories indicate that this method can compensate for the inaccuracy of the strip theories. The results confirm that the irregular wave procedure is a promising method for the accurate prediction of motion responses with less accuracy loss and higher efficiency compared with the regular wave procedure.

  3. Cardiac output during exercise

    DEFF Research Database (Denmark)

    Siebenmann, C; Rasmussen, P.; Sørensen, H.;

    2015-01-01

    Several techniques assessing cardiac output (Q) during exercise are available. The extent to which the measurements obtained from each respective technique compares to one another, however, is unclear. We quantified Q simultaneously using four methods: the Fick method with blood obtained from the...... right atrium (Q(Fick-M)), Innocor (inert gas rebreathing; Q(Inn)), Physioflow (impedance cardiography; Q(Phys)), and Nexfin (pulse contour analysis; Q(Pulse)) in 12 male subjects during incremental cycling exercise to exhaustion in normoxia and hypoxia (FiO2  = 12%). While all four methods reported a...... progressive increase in Q with exercise intensity, the slopes of the Q/oxygen uptake (VO2) relationship differed by up to 50% between methods in both normoxia [4.9 ± 0.3, 3.9 ± 0.2, 6.0 ± 0.4, 4.8 ± 0.2 L/min per L/min (mean ± SE) for Q(Fick-M), Q(Inn), QP hys and Q(Pulse), respectively; P = 0.001] and...

  4. The Future of Neural Networks

    OpenAIRE

    Lakra, Sachin; T. V. Prasad; G. Ramakrishna

    2012-01-01

    The paper describes some recent developments in neural networks and discusses the applicability of neural networks in the development of a machine that mimics the human brain. The paper mentions a new architecture, the pulsed neural network that is being considered as the next generation of neural networks. The paper also explores the use of memristors in the development of a brain-like computer called the MoNETA. A new model, multi/infinite dimensional neural networks, are a recent developme...

  5. Neural networks for aircraft control

    Science.gov (United States)

    Linse, Dennis

    1990-01-01

    Current research in Artificial Neural Networks indicates that networks offer some potential advantages in adaptation and fault tolerance. This research is directed at determining the possible applicability of neural networks to aircraft control. The first application will be to aircraft trim. Neural network node characteristics, network topology and operation, neural network learning and example histories using neighboring optimal control with a neural net are discussed.

  6. Neural Networks in Data Mining

    OpenAIRE

    Priyanka Gaur

    2012-01-01

    The application of neural networks in the data mining is very wide. Although neural networks may have complex structure, long training time, and uneasily understandable representation of results, neural networks have high acceptance ability for noisy data and high accuracy and are preferable in data mining. In this paper the data mining based on neural networks is researched in detail, and the key technology and ways to achieve the data mining based on neural networks are also researched.

  7. Neural networks and graph theory

    Institute of Scientific and Technical Information of China (English)

    许进; 保铮

    2002-01-01

    The relationships between artificial neural networks and graph theory are considered in detail. The applications of artificial neural networks to many difficult problems of graph theory, especially NP-complete problems, and the applications of graph theory to artificial neural networks are discussed. For example graph theory is used to study the pattern classification problem on the discrete type feedforward neural networks, and the stability analysis of feedback artificial neural networks etc.

  8. Neural Oscillators Programming Simplified

    Directory of Open Access Journals (Sweden)

    Patrick McDowell

    2012-01-01

    Full Text Available The neurological mechanism used for generating rhythmic patterns for functions such as swallowing, walking, and chewing has been modeled computationally by the neural oscillator. It has been widely studied by biologists to model various aspects of organisms and by computer scientists and robotics engineers as a method for controlling and coordinating the gaits of walking robots. Although there has been significant study in this area, it is difficult to find basic guidelines for programming neural oscillators. In this paper, the authors approach neural oscillators from a programmer’s point of view, providing background and examples for developing neural oscillators to generate rhythmic patterns that can be used in biological modeling and robotics applications.

  9. Geometric neural computing.

    Science.gov (United States)

    Bayro-Corrochano, E J

    2001-01-01

    This paper shows the analysis and design of feedforward neural networks using the coordinate-free system of Clifford or geometric algebra. It is shown that real-, complex-, and quaternion-valued neural networks are simply particular cases of the geometric algebra multidimensional neural networks and that some of them can also be generated using support multivector machines (SMVMs). Particularly, the generation of radial basis function for neurocomputing in geometric algebra is easier using the SMVM, which allows one to find automatically the optimal parameters. The use of support vector machines in the geometric algebra framework expands its sphere of applicability for multidimensional learning. Interesting examples of nonlinear problems show the effect of the use of an adequate Clifford geometric algebra which alleviate the training of neural networks and that of SMVMs. PMID:18249926

  10. Hidden neural networks

    DEFF Research Database (Denmark)

    Krogh, Anders Stærmose; Riis, Søren Kamaric

    1999-01-01

    A general framework for hybrids of hidden Markov models (HMMs) and neural networks (NNs) called hidden neural networks (HNNs) is described. The article begins by reviewing standard HMMs and estimation by conditional maximum likelihood, which is used by the HNN. In the HNN, the usual HMM probability...... parameters are replaced by the outputs of state-specific neural networks. As opposed to many other hybrids, the HNN is normalized globally and therefore has a valid probabilistic interpretation. All parameters in the HNN are estimated simultaneously according to the discriminative conditional maximum...... likelihood criterion. The HNN can be viewed as an undirected probabilistic independence network (a graphical model), where the neural networks provide a compact representation of the clique functions. An evaluation of the HNN on the task of recognizing broad phoneme classes in the TIMIT database shows clear...

  11. Bone thickness of the infrazygomatic crest area in skeletal Class III growing patients: A computed tomographic study

    International Nuclear Information System (INIS)

    This study was performed to investigate the bone thickness of the infrazygomatic crest area by computed tomography (CT) for placement of a miniplate as skeletal anchorage for maxillary protraction in skeletal Class III children. CT images of skeletal Class III children (7 boys, 9 girls, mean age: 11.4 years) were taken parallel to the Frankfurt horizontal plane. The bone thickness of the infrazygomatic crest area was measured at 35 locations on the right and left sides, perpendicular to the bone surface. The bone was thickest (5.0 mm) in the upper zygomatic bone and thinnest (1.1 mm) in the anterior wall of the maxillary sinus. Generally, there was a tendency for the bone to be thicker at the superior and lateral area of the zygomatic process of the maxilla. There was no clinically significant difference in bone thickness between the right and left sides; however, it was thicker in male than in female subjects. In the infrazygomatic crest area, the superior and lateral area of the zygomatic process of the maxilla had the most appropriate thickness for placement of a miniplate in growing skeletal Class III children with a retruded maxilla.

  12. Bone thickness of the infrazygomatic crest area in skeletal Class III growing patients: A computed tomographic study

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Hyub Soo; Choi, Hang Moon; Choi, Dong Soon; Jang, Insan; Cha, Bong Kuen [College of Dentistry and Research Institute of Oral Science, Gangneung-Wonju National University, Gangneung (Korea, Republic of)

    2013-12-15

    This study was performed to investigate the bone thickness of the infrazygomatic crest area by computed tomography (CT) for placement of a miniplate as skeletal anchorage for maxillary protraction in skeletal Class III children. CT images of skeletal Class III children (7 boys, 9 girls, mean age: 11.4 years) were taken parallel to the Frankfurt horizontal plane. The bone thickness of the infrazygomatic crest area was measured at 35 locations on the right and left sides, perpendicular to the bone surface. The bone was thickest (5.0 mm) in the upper zygomatic bone and thinnest (1.1 mm) in the anterior wall of the maxillary sinus. Generally, there was a tendency for the bone to be thicker at the superior and lateral area of the zygomatic process of the maxilla. There was no clinically significant difference in bone thickness between the right and left sides; however, it was thicker in male than in female subjects. In the infrazygomatic crest area, the superior and lateral area of the zygomatic process of the maxilla had the most appropriate thickness for placement of a miniplate in growing skeletal Class III children with a retruded maxilla.

  13. Neural cryptography with feedback

    Science.gov (United States)

    Ruttor, Andreas; Kinzel, Wolfgang; Shacham, Lanir; Kanter, Ido

    2004-04-01

    Neural cryptography is based on a competition between attractive and repulsive stochastic forces. A feedback mechanism is added to neural cryptography which increases the repulsive forces. Using numerical simulations and an analytic approach, the probability of a successful attack is calculated for different model parameters. Scaling laws are derived which show that feedback improves the security of the system. In addition, a network with feedback generates a pseudorandom bit sequence which can be used to encrypt and decrypt a secret message.

  14. Recurrent Neural Network Regularization

    OpenAIRE

    Zaremba, Wojciech; Sutskever, Ilya; Vinyals, Oriol

    2014-01-01

    We present a simple regularization technique for Recurrent Neural Networks (RNNs) with Long Short-Term Memory (LSTM) units. Dropout, the most successful technique for regularizing neural networks, does not work well with RNNs and LSTMs. In this paper, we show how to correctly apply dropout to LSTMs, and show that it substantially reduces overfitting on a variety of tasks. These tasks include language modeling, speech recognition, image caption generation, and machine translation.

  15. Neural Turing Machines

    OpenAIRE

    Graves, Alex; Wayne, Greg; Danihelka, Ivo

    2014-01-01

    We extend the capabilities of neural networks by coupling them to external memory resources, which they can interact with by attentional processes. The combined system is analogous to a Turing Machine or Von Neumann architecture but is differentiable end-to-end, allowing it to be efficiently trained with gradient descent. Preliminary results demonstrate that Neural Turing Machines can infer simple algorithms such as copying, sorting, and associative recall from input and output examples.

  16. Neural Tube Defects

    OpenAIRE

    Greene, Nicholas D. E.; Copp, Andrew J.

    2014-01-01

    Neural tube defects (NTDs), including spina bifida and anencephaly, are severe birth defects of the central nervous system that originate during embryonic development when the neural tube fails to close completely. Human NTDs are multifactorial, with contributions from both genetic and environmental factors. The genetic basis is not yet well understood, but several nongenetic risk factors have been identified as have possibilities for prevention by maternal folic acid supplementation. Mechani...

  17. Neural Programmer-Interpreters

    OpenAIRE

    Reed, Scott; De Freitas, Nando

    2015-01-01

    We propose the neural programmer-interpreter (NPI): a recurrent and compositional neural network that learns to represent and execute programs. NPI has three learnable components: a task-agnostic recurrent core, a persistent key-value program memory, and domain-specific encoders that enable a single NPI to operate in multiple perceptually diverse environments with distinct affordances. By learning to compose lower-level programs to express higher-level programs, NPI reduces sample complexity ...

  18. Evolution of neural networks

    OpenAIRE

    Uršič, Aleš

    2012-01-01

    The goal of this work is construction of an artificial life model and simulation of organisms in an environment with food. Organisms survive if they find food successfuly. With evolution and learning organisms develop a neural network which enables that. First neural networks and their history are introduced with the basic concepts like a neuron model, a network, transfer functions, topologies and learning. I describe the backpropagation learning on multilayer feed forward network and dem...

  19. Deep Sequential Neural Network

    OpenAIRE

    Denoyer, Ludovic; Gallinari, Patrick

    2014-01-01

    Neural Networks sequentially build high-level features through their successive layers. We propose here a new neural network model where each layer is associated with a set of candidate mappings. When an input is processed, at each layer, one mapping among these candidates is selected according to a sequential decision process. The resulting model is structured according to a DAG like architecture, so that a path from the root to a leaf node defines a sequence of transformations. Instead of c...

  20. Automatic localization of the left ventricle in cardiac MRI images using deep learning.

    Science.gov (United States)

    Emad, Omar; Yassine, Inas A; Fahmy, Ahmed S

    2015-08-01

    Automatic localization of the left ventricle (LV) in cardiac MRI images is an essential step for automatic segmentation, functional analysis, and content based retrieval of cardiac images. In this paper, we introduce a new approach based on deep Convolutional Neural Network (CNN) to localize the LV in cardiac MRI in short axis views. A six-layer CNN with different kernel sizes was employed for feature extraction, followed by Softmax fully connected layer for classification. The pyramids of scales analysis was introduced in order to take account of the different sizes of the heart. A publically-available database of 33 patients was used for learning and testing. The proposed method was able it localize the LV with 98.66%, 83.91% and 99.07% for accuracy, sensitivity and specificity respectively. PMID:26736354