bluuebunny/crossref_metadata_2025_split huggingface dataset:
Evidence for an extracellular matrix bridge guiding proepicardial cell migration to the myocardium of chick embryos
Authors: Nahirney Patrick C. , Mikawa Takashi , Fischman Donald A. 
Published: July 2003

AbstractDuring heart development, the proepicardium (PE) gives rise to cells of the epicardial epithelium, connective tissue of the subepicardium and the myocardium, and smooth muscle, endothelium, and connective tissue of the coronary arteries. The PE arises as an outgrowth of the pericardial serosa at embryonic day 2 (Hamburger and Hamilton stage [HH] 14) of chick development. Between stages HH14 and HH17, multicellular villous projections extend from the PE toward the dorsal aspect of the lesser curvature of the myocardium. On reaching the atrioventricular (AV) junction, the cells spread over the myocardium, eventually enveloping the complete heart surface as a simple squamous epithelium. Although the lineage of the PE cells is well established, it remains uncertain how cells of the PE reach the myocardial surface and specifically target the AV junction. By using a combination of serial section reconstructions, immunofluorescence, and electron microscopy, we have identified an extracellular matrix bridge (ECMB) spanning the coelomic cavity between the PE and the myocardium. The ECMB is first detectable at HH14 and persists until the PE contacts the bare myocardial surface. This ECMB stains intensely with ruthenium red and Alcian blue, contains heparan sulfate and fibronectin, and exhibits both fibrillar and globular ultrastructure, reminiscent of proteoglycans. After PE attachment to the myocardium (HH16–HH17), the subepicardium exhibited strong staining for heparan sulfate. Heparinase injection into the pericardial coelom at HH15 resulted in aberrant development of the primordial epicardium. On the basis of these studies, we suggest that the ECMB may participate in migration and targeting of the PE to the myocardium. Developmental Dynamics 227:511–523, 2003. © 2003 Wiley‐Liss, Inc.
Induction of neurogenin‐1 expression by sonic hedgehog: Its role in development of trigeminal sensory neurons
Authors: Ota Mitsunori , Ito Kazuo 
Published: July 2003

AbstractWe have examined the roles of signaling molecules in the mechanisms underlying the induction of neurogenin (ngn)‐1 expression. ngn‐1 is a basic helix‐loop‐helix (bHLH) transcription factor, which is essential for the specification of trigeminal sensory neurons. Semiquantitative reverse transcriptase‐polymerase chain reaction using cranial explants in organ cultures showed that sonic hedgehog (Shh) promotes ngn‐1 expression. This promoting activity was not observed in other signaling molecules examined. The promotion of ngn‐1 expression by Shh, furthermore, was inhibited by cyclopamine, a specific inhibitor of Shh signaling. Shh did not affect the expression of ngn‐2, a bHLH transcription factor that plays an important role in the specification of epibranchial placode‐derived sensory neurons. The expression levels of ngn‐1 and ngn‐2 decreased after fibroblast growth factor‐2 treatment. These results suggest that Shh induces ngn‐1 expression specifically and that expression of ngn‐1 and ngn‐2 is regulated by different mechanisms. The induction of ngn‐1 expression by Shh suggests that this signaling molecule participates in the specification of trigeminal sensory neurons. We therefore examined the effect of Shh on the development of these neurons. Immunostaining using anti–ngn‐1 demonstrated that Shh promotes ngn‐1 expression in trigeminal neural crest cells. Trigeminal neural crest cells are derived from the posterior mesencephalon and the most‐anterior rhombencephalon, and they contain a subset of precursors of trigeminal sensory neurons. Moreover, a subpopulation of trigeminal neural crest cells expressed the Shh receptor Patched. The number of cells that express Brn3a, a POU‐domain transcription factor that plays an important role in differentiation of sensory neurons, also increased with Shh treatment. Our data suggest that Shh signaling is involved in the specification of trigeminal sensory neurons through the induction of ngn‐1 expression. Furthermore, Shh promotes the differentiation of neural crest cells into trigeminal sensory neurons. Developmental Dynamics 227:554–551, 2003. © 2003 Wiley‐Liss, Inc.
Pluripotency of reprogrammed somatic genomes in embryonic stem hybrid cells
Authors: Tada Masako , Morizane Asuka , Kimura Hironobu , Kawasaki Hiroshi , Ainscough Justin F.X. , Sasai Yoshiki , Nakatsuji Norio , Tada Takashi 
Published: July 2003

AbstractSomatic nuclei can be epigenetically reprogrammed by factors present in undifferentiated embryonic stem (ES) cells. The acquisition of pluripotency by somatic genomes could render such cells a viable source of personalized cell type(s) for therapeutic application, avoiding the need for controversial therapeutic cloning. To investigate this possibility, we first determined the origin of transcripts in teratomas generated from mouse (ES × somatic cell) hybrid clones. Transcription of markers from the somatic genome demonstrated efficient in vivo differentiation down independent lineages. The induction of dopaminergic neurons by coculture with stromal PA6 feeder cells also demonstrated efficient capacity to differentiate in vitro. Hybrid clone‐derived neurons expressed appropriate markers, and transcription of Pitx3 from the somatic genome was confirmed. When transplanted into mouse brains, the dopaminergic neurons were successfully integrated and expressed tyrosine hydroxylase. Thus, it should be possible to produce personalized ES‐like cells with the reprogrammed somatic genomes. Developmental Dynamics 227:504–510, 2003. © 2003 Wiley‐Liss, Inc.
Establishment of a ventral cell fate in the spinal cord
Authors: Moghadam Kaveh S. , Chen Aileen , Heathcote R. David 
Published: July 2003

AbstractThe neural plate is induced during gastrulation when the organizer affects the ectoderm around it. Recent experiments show that axial mesoderm can stimulate formation of specific ventral cell types in the spinal cord, including floor plate, motor neurons, and several types of interneurons. We have eliminated or disrupted axial mesoderm by using a variety of methods to show that ventral columns of intermittent dopaminergic neurons in the frog Xenopus also appear to be induced by axial mesoderm. Inversion of the dorsal‐ventral neural axis by splitting the presumptive neural plate in vivo, produced two spinal cords with ectopic dopaminergic neurons. The location and number of neurons suggest that even a brief association with axial mesoderm can specify the identity of the first or primary dopaminergic neurons and that notochord retains the ability to induce cells to become secondary dopaminergic neurons. Developmental Dynamics 227:552–562, 2003. © 2003 Wiley‐Liss, Inc.
Progranulin (acrogranin/PC cell‐derived growth factor/granulin‐epithelin precursor) is expressed in the placenta, epidermis, microvasculature, and brain during murine development
Authors: Daniel Rachael , Daniels Eugene , He Zhiheng , Bateman Andrew 
Published: July 2003

AbstractThe growth factor progranulin (acrogranin/PC‐derived growth factor/granulin‐epithelin precursor) promotes onset of blastocyst cavitation and is required for neonatal hypothalamic sexual differentiation. Little is known, however, of the range of developmental processes in which it is involved. We used in situ hybridization to investigate progranulin expression in murine embryos. Progranulin mRNA is expressed in maternal and embryonic components during early establishment of pregnancy. Abundant expression is observed in the early decidualizing uterine stroma and glands. In the embryo, the trophoblast giant cells at the interface of placental exchange sites (both choriovitelline and chorioallantoic placenta) show strong expression. The gastrulating epiblast and mesenchyme (intraembryonic and extraembryonic mesenchyme) all revealed activity. The allantois and yolk sac mesenchyme (site of early hemopoiesis) were positive, as were later phases of active vessel formation (pia mater of brain, epicardium of the heart). In the urogenital system, it was expressed in Sertoli cells and in kidney tubules. It was highly expressed in proliferating epidermal cells. During epidermal appendage formation, the early epithelial bud was positive, but the forming duct and differentiating adjacent mesenchyme was negative. It is widely distributed during central nervous system development and the peripheral nervous system (dorsal root ganglia and sympathetic ganglia). Based on the pattern of progranulin gene expression, we propose proliferative and developmental roles for progranulin in establishing pregnancy, during gastrulation, and during embryonic development of the epidermis, nervous system, blood vessel, formation, and spermatogenesis. Developmental Dynamics 593–599, 2003. © 2003 Wiley‐Liss, Inc.
Candidate testis‐determining gene, Maestro (Mro), encodes a novel HEAT repeat protein
Authors: Smith Lee , Van Hateren Nick , Willan John , Romero Rosario , Blanco Gonzalo , Siggers Pam , Walsh James , Banerjee Ruby , Denny Paul , Ponting Chris , Greenfield Andy 
Published: July 2003

AbstractMammalian sex determination depends on the presence or absence of SRY transcripts in the embryonic gonad. Expression of SRY initiates a pathway of gene expression resulting in testis development. Here, we describe a novel gene potentially functioning in this pathway using a cDNA microarray screen for genes exhibiting sexually dimorphic expression during murine gonad development. Maestro (Mro) transcripts are first detected in the developing male gonad before overt testis differentiation. By 12.5 days postcoitus (dpc), Mro transcription is restricted to the developing testis cords and its expression is not germ cell‐dependent. No expression is observed in female gonads between 10.5 and 14.5 dpc. Maestro encodes a protein containing HEAT‐like repeats that localizes to the nucleolus in cell transfection assays. Maestro maps to a region of mouse chromosome 18 containing a genetic modifier of XX sex reversal. We discuss the possible function of Maestro in light of these data. Developmental Dynamics 227:600–607, 2003. © 2003 Wiley‐Liss, Inc.
Expression of the Wdr9 gene and protein products during mouse development
Authors: Huang He , Rambaldi Isabel , Daniels Eugene , Featherstone Mark 
Published: July 2003

AbstractHuman WDR9 has been mapped to chromosome 21, within one of the Down syndrome (DS) critical regions. Here, we study the expression pattern of the murine Wdr9 gene and its protein product. We show that Wdr9 is broadly expressed in the mouse embryo by means of in situ hybridization and immunohistochemistry. Wdr9 expression levels are dynamic during embryonic development as revealed by Northern blot analysis. We further show that WDR9 is a nuclear protein associated with BRG1, a SWI/SNF complex component. We also demonstrate that a polyglutamine‐containing region of the protein functions as a transcriptional activation domain. We propose that WDR9 is a transcriptional regulator involved in chromatin remodeling through the action of two bromodomains and contacts to the SWI/SNF complex. These results may provide a molecular basis for the association of WDR9 with DS. Developmental Dynamics 227:608–614, 2003. © 2003 Wiley‐Liss, Inc.
Intercalary and supernumerary regeneration in the limbs of the frog, Xenopus laevis
Authors: Shimizu‐Nishikawa Keiko , Takahashi Jun , Nishikawa Akio 
Published: July 2003

AbstractAnuran amphibians, such as Xenopus laevis, can regenerate their limbs only when they are young tadpoles, whereas urodele amphibians have a regenerative ability throughout their lives. It is still unclear whether anuran and urodele use the same mechanism during regeneration. In the present study, we analyzed intercalary and supernumerary regeneration in Xenopus. In contrast to urodele blastema that induces intercalary regeneration along the proximodistal (PD) axis, intercalation did not occur in the Xenopus limb bud when the presumptive zeugopodium (fibula and tibia) was removed. However, when the limb bud tip (presumptive autopodium) was transplanted to the presumptive stylopodium (femur) with a 180‐degree rotation at stage 52, the complete zeugopodium was regenerated. These results were similar to the results of urodele mature limbs, suggesting that Xenopus limb buds are equivalent to the urodele mature limbs but not to the urodele blastemas. We hypothesized that the ability for intercalation depends on the expression pattern of fibroblast growth factor (fgf)‐8, because the expression of fgf‐8 in the urodele spreads over the whole blastema and is close enough to activate the growth of the stump. To test this hypothesis, an FGF‐8–soaked bead was implanted at the boundary between the stump and tip of a Xenopus limb bud. Intercalary regeneration was induced at stages 52 and 53. These results suggest that the Xenopus limb bud possesses the potential for intercalation, but endogenous FGF‐8 in the apical ectodermal ridge (AER) does not induce intercalation to the stump because of the long distance between the AER and stump. Developmental Dynamics 227:563–572, 2003. © 2003 Wiley‐Liss, Inc.
Occupation choices of adults with and without symptoms of dyslexia
Authors: Taylor Kathleen E. , Walter Janet 
Published: July 2003

AbstractPeople with the learning disability developmental dyslexia characteristically have difficulties in processing written language. There is some evidence that they may also have talents in other areas such as visuospatial processing. This pattern of strengths and weaknesses may predispose people who have dyslexia towards adopting certain occupations and away from others. Although there is literature on career choice in learning disabled adults in general, relatively little work has been done specifically for dyslexia. We therefore compared the occupations of adults with and without symptoms of developmental dyslexia. Results were analysed using non‐parametric statistics and are illustrated with a case study. We found significant differences in the distribution of our samples. Adults with symptoms of dyslexia were much less likely than adults not reporting such symptoms to be involved in professions such as science/computing, management and finance. They were more likely to be involved in people‐oriented professions such as nursing or sales. While preliminary, these results suggest that people with dyslexia may indeed show significantly different patterns of occupation choice. Copyright © 2003 John Wiley & Sons, Ltd.
Reading intervention: A ‘conventional’ and successful approach to helping dyslexic children acquire literacy
Authors: Hatcher Peter J. 
Published: July 2003

AbstractThe effectiveness of the ‘conventional’ approach to helping children with dyslexia to acquire literacy has been questioned by Reynolds et al. (Dyslexia 2003). Data are presented in this reply to support the effectiveness of Reading Intervention, a conventional approach to teaching reading delayed children. Copyright © 2003 John Wiley & Sons, Ltd.
Measurement mischief: A critique of Reynolds, Nicolson and Hambly (2003)
Authors: Singleton Chris , Stuart Morag 
Published: July 2003

AbstractReynolds, Nicolson and Hambly (2003) report an intervention study of the effects of exercise‐based training on literacy development, using literacy measures from the Dyslexia Screening Test (DST), the NFER‐Nelson Group Reading Test, and the Standard Assessment Tasks (SATs). Investigation of the nature and psychometric characteristics of these measures casts serious doubt on their appropriateness in a study of this nature. Consideration of the findings obtained using these measures does not support the authors' conclusion that reading was improved by the intervention. The study by Reynolds et al. does not demonstrate that exercise‐based treatment improves literacy skills and the use of its purported findings as evidence that exercise‐based treatment would be beneficial for children with literacy difficulties is scientifically untenable. Copyright © 2003 John Wiley & Sons, Ltd.
Science, sense and synergy: Response to commentators
Authors: Nicolson Roderick I. , Reynolds David 
Published: July 2003

AbstractThe commentaries on our evaluation of the DDAT exercise treatment raise several common themes and several individual themes. We rebut criticisms in terms of research design, consider the comments made, and conclude that our evidence is indeed solid. We conclude by advocating ‘science, sense and synergy’ as the key to making further progress. Copyright © 2003 John Wiley & Sons, Ltd.
Measurements of electron density profile characteristics in various kinds of plasma configurations in the TS‐3 plasma merging device
Authors: Hayashiya Hitoshi , Katsurai Makoto 
Published: July 2003

AbstractMeasurements and a comparative study have been performed on electron density profiles, focusing on the electron density gradient near the magnetic separatrix in various kinds of plasma confinements such as the ST, spheromak, and RFP in the TS‐3 device. A CO2 laser interferometer using a glass tube to clear the path for the laser was introduced in order to measure the electron density profile with time resolution. It was shown that ST with a high q value at the plasma edge (q: safety factor) has a larger electron density gradient than low‐q plasma confinements such as the spheromak and RFP. In particular, the ST with edge q value greater than about 2 showed a large electron density gradient at the edge. The idea that the j×B force profile of the higher‐q ST could sustain the higher thermal pressure supports these results. © 2003 Wiley Periodicals, Inc. Electr Eng Jpn, 145(2): 35–41, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.10158
Dynamical movements of electron density profiles in spherical tokamak merging processes
Authors: Hayashiya Hitoshi , Katsurai Makoto 
Published: July 2003

AbstractPlasma merging is a promising, innovative method of initial heating for spherical tokamak (ST) plasmas. Detailed measurements of the temporal evolution of electron density profiles during plasma merging processes in a TS‐3 device was studied using a CO2 laser interferometer with temporal and spatial resolution. The experimental observations show that the electrons are confined securely inside the magnetic separatrix in the moving plasma during the merging process. It has been found that the plasma particles are not ejected from the confinement region during the magnetic reconnection event, even though the magnetic structure of the plasma is changed drastically. Furthermore, it is shown that the electron density profile becomes hollow after plasma merging. These results indicate that plasma merging is effective not only as a method of initial heating of the ST, but also as a means of particle supply to the ST. © 2003 Wiley Periodicals, Inc. Electr Eng Jpn, 145(2): 42–49, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.10159
Numerical analysis and experimental investigation of discharge characteristics in a ring dielectric line surface‐wave processing plasma apparatus
Authors: Kim Jaeho , Itagaki Toshifumi , Katsurai Makoto 
Published: July 2003

AbstractDischarge characteristics in ring dielectric line surface‐wave processing plasma (RDL‐SWP) apparatus are studied both numerically and experimentally. To numerically simulate electromagnetic waves in SWP apparatus with a cylindrical discharge chamber such as RDL‐SWP apparatus, a three‐dimensional computer code is developed, employing Cartesian coordinates to allow simulation of both the plasma and rectangular waveguide connected to the chamber. The finite difference time domain (FDTD) method is the basis of the numerical code. Electron density and temperature profiles are measured experimentally in Ar plasma using a movable single probe and the optical emission patterns are studied. It is found that peaks in the electron density profiles coincide with intense optical emissions. For profiles across bulk plasmas with densities higher than cut‐off, diffusion effects are found to be more dominant than localized plasma effects produced by surface waves. In particular, by comparison of numerical and experimental results, the applicability and limitations of a plasma model in which uniform electron density is assumed are evaluated. © 2003 Wiley Periodicals, Inc. Electr Eng Jpn, 145(2): 10–20, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.10174
Conduction of water clusters in modified aged oil
Authors: Ota Koji , Miura Masaki , Sone Mototaka , Mitsui Hideo 
Published: July 2003

AbstractDissolved water in insulating liquids has been regarded as a kind of impurity that degrades electrical properties. Recently, the state and the behavior of water molecules in liquid have been measured by infrared methods, making it possible to analyze where water molecules are bound to dielectric molecules and how many molecules gather around polar radicals on the alkyl chain.In the case of transformer oil, which consists almost entirely of saturated hydrocarbons, the content of oxidation products is gradually increased by aging during use. These oxidation products include polar radicals such as carbonyl and ketone radicals. When water dissolves in such oil, water molecules interact with these polar radicals to form water clusters, which can make the conductivity increase. In the research reported here, partially oxidized hydrocarbon was mixed with saturated hydrocarbon and the effect of water clusters around ketone radicals on the conductivity was investigated. When the content of oxidation products was less than 10%, the conductivity did not increase with an increase in the amount of water. But when the ratio exceeded 10%, specific kinds of water clusters increased the conductivity. It appears that these clusters consist of water molecules gathered around one ketone radical. © 2003 Wiley Periodicals, Inc. Electr Eng Jpn, 145(2): 21–27, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.10178
Electric field measurement just beneath a surface discharge by optical‐waveguide pockels sensors
Authors: Takahashi Tsuguhiro 
Published: July 2003

AbstractAlthough surface discharges are one of the principal kinds of phenomena associated with faults in electrical apparatus, they have not yet been fully elucidated. Electric field measurements in and around a corona streamer during the creeping advance of a surface discharge are very helpful in analyzing discharges. Pockels crystals have been used in the optical measurement of electric fields, and an optical waveguide technique has been successfully used to miniaturize the sensors. Electric field measurements are made just beneath a surface discharge with an optical waveguide Pockels sensor installed on a PMMA plate and output signals expressing the development of the discharge are obtained. © 2003 Wiley Periodicals, Inc. Electr Eng Jpn, 145(2): 28–34, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.10185