bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of Exogenous Thyroid Hormone on the Postnatal Morphogenesis of the Rat Parotid Gland
Authors: Ikeda Rie , Aiyama Shigeo , Redman Robert S. 
Published: December 2007

AbstractAdministration of thyroid hormone has been shown to accelerate the early postnatal development of the rat parotid gland, but these studies have dwelt almost entirely on biochemical changes. The objective of this study was to describe the effects of exogenous thyroid hormone on morphologic aspects of the developing parotid gland, in particular the transient appearance of scattered mucous cells in this otherwise serous gland. Pups were given a daily subcutaneous injection of thyroxine (T4) of 0.1, 0.5, or 5.0 μg/g body weight, vehicle only (injection control), or no injection (normal control) beginning at 4 days, and killed for the collection of blood and parotid glands at intervals through 15 days. The serum was analyzed for T4 and the glands were examined by light and electron microscopy. The results indicated that both serum T4 and the pace of gland development were proportional to the dose of T4. In particular, T4 accelerated decreases in acinar size and gland area occupied by stroma and translocation of a subset of cells with small secretory granules, deeply stained with periodic acid–Schiff, from acini to intercalated ducts. However, the chronology of mucous cell disappearance was indifferent to treatment. In addition, signs of toxicity, including slower gain in body weight and greatly increased apoptosis and vacuoles in the glands, occurred with the higher doses of T4. Anat Rec, 291:94–104, 2007. © 2007 Wiley‐Liss, Inc.
Special Features of Dermal Melanocytes in White Silky Chicken Embryos
Authors: Ortolani‐Machado Claudia , De Freitas Patrícia , Borges Marisa E. , Faraco Cloris 
Published: December 2007

AbstractIn the hyperpigmented Silky (SK) chicken, melanoblasts are neural crest cells that emigrate from the neural tube, migrate dorsolaterally, close to the ectoderm and medioventrally, reaching visceral regions of the embryo, as well as populating the dermis. In this work, we analyzed the morphology and distribution of melanocytic lineage cells in white SK embryos at later stages of development (6 to 19 days of incubation) focusing in the dermis of dorsal skin to characterize this ectopically located population. Melanoblasts and immature melanocytes are seen at all analyzed stages, some of them clearly proliferative, suggesting a possibility of continued renewal of the population. Mature, fully differentiated melanocytes are elongated cells with many long cytoplasmic processes, forming a meshwork in superficial dermis, below a layer of collagen and elastic fibers that seems to prevent melanocytic lineage cells from reaching the epidermis at these later stages. SK chicken is the onlyGallus gallusbreed to display this arrangement of dermal melanocytes. The distribution of melanocytes below the collagen layer, observed in regions covered by feathers, is clearly not related with structural coloration as in areas of bare skin. Other functions for this conserved trait in SK must be investigated. Anat Rec, 291:55–64, 2007. © 2007 Wiley‐Liss, Inc.
Development of Outer Hair Cells in Ames Waltzer Mice: Mutation in Protocadherin 15 Affects Development of Cuticular Plate and Associated Structures
Authors: Kikkawa Yayoi S. , Pawlowski Karen S. , Wright Charles G. , Alagramam Kumar N. 
Published: December 2007

AbstractThe Ames waltzer (av) mouse mutant harbors a mutation in the protocadherin 15 gene (Pcdh15) and is a model for deafness in Usher syndrome 1F and nonsyndromic deafness DFNB23. Mutation in Pcdh15 affects stereocilia morphogenesis and polarity. Disruptions of apical cellular components in outer hair cells have also been described in av mutants. Organization of stereocilia and cell polarization may be dependent on proper orientation of structural components residing in the apical portion of the cell during development. We used electron and immunofluorescent microscopy to examine structural maturation of outer hair cells in av3J mice with emphasis on the fonticulus, basal body/centriole complex, actin mesh, and the microtubule network during initiation of bundle organization, between embryonic day (E) 16.5 and postnatal day 5 (P5). We found major ultrastructural rearrangements near the hair cell surface in av3J mice. Earliest changes were in kinocilia, basal body, and stereocilia positioning and microtubule arrangement once the kinocilia had lateralized to the side of the cell (between E16.5 and postnatal day [P] 0, before cuticular plate formation and stereocilia elongation). By P0, the developing fonticulus in av mice appeared enlarged, with a normal vesicle density. Stereocilia bundle disorganization increased after P0, with disruptions of the actin mesh within the cuticular plate. These observations support the hypothesis that mutations in Pcdh15 in av3J mice adversely affect coordinated maturation of apical cell components, resulting in disturbed stereocilia bundle polarity in av mice. Anat Rec, 2007. © 2008 Wiley‐Liss, Inc.
Modelling a general standby system and evaluation of its performance
Authors: Cha Ji Hwan , Mi Jie , Yun Won Young 
Published: December 2007

AbstractRedundancy or standby is a technique that has been widely applied to improving system reliability and availability in system design. In this paper, a general method for modelling standby system is proposed and system performance measures are derived. It is shown that the proposed general standby system includes the cases of cold, hot and warm standby systems with units of exponential distribution, which were studied in the literature, as special cases. An optimal allocation problem for a standby system is also discussed. Copyright © 2007 John Wiley & Sons, Ltd.
The helix‐loop‐helix protein Id2 is expressed differentially and induced by myc in T‐cell lymphomas
Authors: Cotta Claudiu V. , Leventaki Vasiliki , Atsaves Vassilis , Vidaki Athina , Schlette Ellen , Jones Dan , Medeiros L. Jeffrey , Rassidakis George Z. 
Published: December 2007

AbstractBACKGROUND.Inhibitor of DNA binding 2 (Id2), a helix‐loop‐helix protein of the inhibitor of differentiation (ID) family, is involved in hematopoiesis, mainly through interaction with the E‐family of transcription factors. Recent studies have shown that Id2 is overexpressed in some types of B‐cell lymphoma, including classical Hodgkin lymphoma. The authors of the current study hypothesized that Id2 also is overexpressed in T‐cell lymphomas.METHODS.By using reverse‐transcriptase polymerase chain reaction (RT‐PCR) and Western blot analyses, high Id2 messenger RNA (mRNA) and protein levels, respectively, were detected in all 4 T‐cell anaplastic large cell lymphoma (ALCL) cell lines that were tested.RESULTS.Immunohistochemistry results indicated that Id2 was expressed strongly in 21 of 27 (78%) ALCL tumors (79% anaplastic lymphoma kinase [ALK]‐negative and 75% ALK‐positive), in 5 of 10 (50%) extranodal natural killer/T (NK/T)‐cell lymphomas of the nasal type, in 2 of 8 (25%) cutaneous ALCLs, in 2 of 9 (22%) enteropathy type T‐cell lymphomas, in 1 of 5 (20%) peripheral T‐cell lymphomas not otherwise specified, and in 1 of 8 (13%) T‐cell prolymphocytic leukemias. Other types of T‐cell lymphoma were negative for Id2. Because it is known that myc is expressed in ALCL, myc was inhibited selectively in 2 ALCL cell lines, resulting in a concentration‐dependent decrease in Id2 mRNA and protein levels. Conversely, forced expression of myc in HEK 293T cells using an myc/green fluorescent protein adenoviral vector resulted in Id2 up‐regulation.CONCLUSIONS.Taken together, the current data suggest that Id2 commonly is overexpressed in highly proliferative T‐cell lymphomas, and its expression may result from transcriptional activation of myc in these tumors. Cancer 2008. © 2007 American Cancer Society.
On the implications of the classical ergodic theorems: Analysis of developmental processes has to focus on intra‐individual variation
Authors: Molenaar Peter C.M. 
Published: December 2007

AbstractIt is argued that general mathematical‐statistical theorems imply that standard statistical analysis techniques of inter‐individual variation are invalid to investigate developmental processes. Developmental processes have to be analyzed at the level of individual subjects, using time series data characterizing the patterns of intra‐individual variation. It is shown that standard statistical techniques based on the analysis of inter‐individual variation appear to be insensitive to the presence of arbitrary large degrees of inter‐individual heterogeneity in the population. An important class of nonlinear epigenetic models of neural growth is described which can explain the occurrence of such heterogeneity in brain structures and behavior. Links with models of developmental instability are discussed. A simulation study based on a chaotic growth model illustrates the invalidity of standard analysis of inter‐individual variation, whereas time series analysis of intra‐individual variation is able to recover the true state of affairs. © 2007 Wiley Periodicals, Inc. Dev Psychobiol 50: 60–69, 2008.
Notch signaling is activated by TLR stimulation and regulates macrophage functions
Authors: Palaga Tanapat , Buranaruk Chayanit , Rengpipat Sirirat , Fauq Abdul H. , Golde Todd E. , Kaufmann Stefan H. E. , Osborne Barbara A. 
Published: December 2007

AbstractNotch signaling is a well‐conserved pathway involved in cell fate decisions, proliferation and apoptosis. We report on the involvement of Notch signaling in regulating gene expression in activated macrophages. Toll‐like receptors (TLR) agonists such as bacterial lipopeptide, polyI:C, lipopolysaccharide and unmethylated CpG DNA all induced up‐regulation of Notch1 in primary and macrophage‐like cell lines. Notch1 up‐regulation was dependent on the MyD88 pathway when stimulated through TLR2, but not TLR4. Activated Notch1 and expression of the Notch target genes, Hes1 and Deltex, were detected in activated macrophages, suggesting that Notch signaling was activated upon stimulation. Inhibiting processing of Notch receptor by γ‐secretase using a γ‐secretase inhibitor (GSI), the expression of Notch1 was down‐regulated to basal levels. This treatment significantly modulated expression of TNF‐α, IL‐6, and IL‐10. In addition, the amount of nitric oxide produced was significantly lower and the expression of MHC class II was up‐regulated in GSI‐treated cells. Treatment with GSI or silencing Notch1 resulted in decreased translocation of NF‐κBp50 into nucleus upon stimulation. Taken together, stimulation of macrophages through the TLR signaling cascade triggered activation of Notch signaling, which in turn regulated gene expression patterns involved in pro‐inflammatory responses, through activation of NF‐κB.
Levels of autoantibodies, unlike antibodies to all extrinsic antigen groups, fall following B cell depletion with Rituximab
Authors: Ferraro Alastair J. , Drayson Mark T. , Savage Caroline O. S. , MacLennan Ian C. M. 
Published: December 2007

AbstractMany autoantibodies have variable‐region sequences indicating their production in an affinity‐matured antibody response involving germinal centers (GC). Plasma cells from GC can be long‐lived, do not express CD20 and thus should not be depleted by a therapeutic monoclonal Ab against human CD20 ‐ Rituximab. Nevertheless, autoantibody titers often fall following Rituximab treatment. To test if this reflects exclusive production by short‐lived plasma cells in extrafollicular Ab responses, we monitored, after Rituximab treatment, levels of natural Ab and Ab against extrinsic antigens that do not induce productive GC. Eleven patients with active vasculitis and anti‐proteinase‐3 (PR3) Ab were assessed before and during 5 months after Rituximab therapy. Blood B cells were undetectable within 2 wk, and all patients achieved clinical remission. Levels of natural Ab – isohemagglutinins and anti‐phosphorylcholine Ab – and Ab levels against thymus‐independent and thymus‐dependent extrinsic antigens were little affected. By contrast, 5 months after Rituximab, IgG autoantibody against PR3 had fallen to a median of 22% of pretreatment values. While the kinetics of this fall do not suggest an intrinsically short lifespan of autoantibody‐producing cells, the data are consistent with Rituximab causing loss of sites within inflammatory tissues that selectively sustain autoantibody‐producing cells.
Regression with spatially misaligned data
Authors: Madsen L. , Ruppert D. , Altman N. S. 
Published: December 2007

AbstractWe present a simple approach to the problem of estimating the regression slope parameter from spatially misaligned point data. We assume a linear regression model with errors and covariates from two independent Gaussian spatial processes where covariate and response are observed at different locations. Correlation in the covariate is exploited to predict unobserved covariates via kriging. Kriged values are used to find weighted least squares estimates of regression parameters in a ‘krige‐and‐regress’ (KR) procedure. The variance of this estimator is calculated, and a variance estimator is proposed. Because the model and assumptions make it possible to write down the joint likelihood of the data, a maximum likelihood (ML) estimator can be found. Under regularity conditions, this estimator is asymptotically normal with asymptotic variance given by the inverse information matrix, which yields a variance estimator for the ML estimator of the regression parameters. The KR and ML estimators are compared in an example using Environmental Protection Agency data and a simulation study is conducted. While the ML estimator of the slope parameter has a smaller variance than the KR estimator, the ML variance estimator is too small to be used for inference whereas the KR variance estimator gives approximately correct inference. Copyright © 2007 John Wiley & Sons, Ltd.
Raviart–Thomas and Brezzi–Douglas–Marini finite‐element approximations of the shallow‐water equations
Authors: Rostand V. , Le Roux D. Y. 
Published: December 2007

AbstractAn analysis of the discrete shallow‐water equations using the Raviart–Thomas and Brezzi–Douglas–Marini finite elements is presented. For inertia–gravity waves, the discrete formulations are obtained and the dispersion relations are computed in order to quantify the dispersive nature of the schemes on two meshes made up of equilateral and biased triangles. A linear algebra approach is also used to ascertain the possible presence of spurious modes arising from the discretization. The geostrophic balance is examined and the smallest representable vortices are characterized on both structured and unstructured meshes. Numerical solutions of two test problems to simulate gravity and Rossby modes are in good agreement with the analytical results. Copyright © 2007 John Wiley & Sons, Ltd.
On restraining convective subgrid‐scale production in Burgers' equation
Authors: Helder Joop , Verstappen Roel 
Published: December 2007

AbstractSince most turbulent flows cannot be computed directly from the (incompressible) Navier–Stokes equations, a dynamically less complex mathematical formulation is sought. In the quest for such a formulation, we consider nonlinear approximations of the convective term that preserve the symmetry and conservation properties. The underlying idea is to restrain the convective production of small scales in an unconditionally stable manner, meaning that the approximate solution cannot blow up in the energy norm. In this paper, the method is worked out and tested successfully for Burgers' equation. Copyright © 2007 John Wiley & Sons, Ltd.
Novel biostable and biocompatible amphiphilic membranes
Authors: Jewrajka Suresh K. , Erdodi Gabor , Kennedy Joseph P. , Ely Daniel , Dunphy Gail , Boehme Shannon , Popescu Flavius 
Published: December 2007

AbstractWe determined the biostability and biocompatibility of two types of amphiphilic conetworks (APCNs): (1) hydrophilic poly(N,N‐dimethyl acrylamide) (PDMAAm) and hydrophobic polydimethylsiloxane (PDMS) microdomains co‐crosslinked with polymethylhydrosiloxane (PMHS) clusters (PDMAAm/PMHS/PDMS), and (2) poly(ethylene glycol) (PEG) and PDMS microdomains co‐crosslinked with two specially designed small‐molecule crosslinking agents SiC6H5(SiH)2OEt (Y) and polypentamethylhydrocyclosiloxane (PD5) (PEG/Y or PD5/PDMS). Negative standards for comparing biocompatibility and biostability were crosslinked PDMS. Biostability was assessed by quantitatively determining extractables, equilibrium water swelling, mechanical properties (stress‐strain response) of polymer samples before and after implantation in rats for up to 8 weeks, and oxidative accelerated degradation test. Biocompatibility was assessed by determining body weight, fibrous tissue encapsulation, fluid accumulation, and by histological evaluation of lymphocyte infiltration, fibrous tissue accumulation and collagen deposition. According to these stringent metrics PDMAAm/PMHS/PDMS is both biostable and biocompatible, whereas PEG/Y or PD5/PDMS degrades in living tissue but is biocompatible. Surprisingly, the overall biocompatibility scores of these APCNs were superior to those of the PDMS negative standard. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2008
The relationship between femoral periprosthetic cortical bone geometry and porosity after total hip arthroplasty
Authors: Rosenbaum Chou Teri G. , Child Jeremy R. , Naughtin Ryan J. , Rigdon Ryan R. , Schumann Craig , Bloebaum Roy D. 
Published: December 2007

AbstractStress shielding from the presence of a femoral component can cause adverse changes to cortical bone geometry and porosity leading to increased fracture risk in the periprosthetic cortical bone. The objectives of this study were to determine if porosity increased after total hip arthroplasty along the principal axes, and to determine if a relationship existed between cortical bone porosity and geometry. Ten postmortem donors allowed comparisons of implanted femurs to the contralateral nonimplanted femurs. Transverse cross‐sections of the femur were taken at 25, 45, 65, and 85% along the length of the femoral component. The cortical bone principal axes' location (degrees) and rigidity values (mm4) were based on cortical bone geometry by using digitized images of the cortical bone cross‐sections. Percent porosity was measured along the principal axes using backscatter electron imaging. Cortical bone porosity increased in the more distal sections of the implanted femurs by ∼3%, but did not preferentially increase along a particular principal axis. No correlation was found between changes in porosity and rigidity values. In conclusion, the porosity increases in the implanted femurs may have regionally reduced cortical bone strength. The locations of higher porosity did not appear related to the cortical bone geometry. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2008
Biocompatibility of atomic layer‐deposited alumina thin films
Authors: Finch Dudley S. , Oreskovic Tammy , Ramadurai Krishna , Herrmann Cari F. , George Steven M. , Mahajan Roop L. 
Published: December 2007

AbstractPresented in this paper is a study of the biocompatibility of an atomic layer‐deposited (ALD) alumina (Al2O3) thin film and an ALD hydrophobic coating on standard glass cover slips. The pure ALD alumina coating exhibited a water contact angle of 55° ± 5° attributed, in part, to a high concentration of OH groups on the surface. In contrast, the hydrophobic coating (tridecafluoro‐1,1,2,2‐tetrahydro‐octyl‐methyl‐bis(dimethylamino)silane) had a water contact angle of 108° ± 2°. Observations using differential interference contrast microscopy on human coronary artery smooth muscle cells showed normal cell proliferation on both the ALD alumina and hydrophobic coatings when compared to cells grown on control substrates. These observations suggested good biocompatibility over a period of 7 days in vitro. Using a colorimetric assay technique to assess cell viability, the cellular response between the three substrates can be differentiated to show that the ALD alumina coating is more biocompatible and that the hydrophobic coating is less biocompatible when compared to the control. These results suggest that patterning a substrate with hydrophilic and hydrophobic groups can control cell growth. This patterning can further enhance the known advantages of ALD alumina, such as conformality and excellent dielectric properties for bio‐micro electro mechanical systems (Bio‐MEMS) in sensors, actuators, and microfluidics devices. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2008
Biomimetic fabrication of fibrin/apatite composite material
Authors: Yoh Rui , Matsumoto Takuya , Sasaki Jun‐ichi , Sohmura Taiji 
Published: December 2007

AbstractBidirectional diffusion of the Ca and PO4 solutions into the fibrin gel was performed at various pH conditions and fluoride concentrations to generate organic/inorganic composite materials mimicking biomineralization. The minerals produced in this system had a higher crystallinity than those generated by the solution mineralization system. The minerals generated in fibrin gel varied depending on the pH conditions as follows: Dicalcium phosphate dihydrate (DCPD) in the noncontrolled pH solution, the DCPD and octacalcium phosphate (OCP) mixture at pH 7.4, and the OCP and hydroxyapatite (HAp) mixture at pH 9.0. When fluoride ions were added in the range of 2–500 ppm, the minerals produced at pH 7.4 altered from OCP/HAp to HAp/fluorapatite (FAp). In addition, the crystallinity of the obtained minerals increased with an increase in fluoride ion concentration, and the solubility was inversely correlated to crystallinity. In conclusion, we established a novel fabrication method for synthesizing organic/inorganic composite materials composed of fibrin and calcium phosphate and revealed that the characteristics of the minerals in the synthesized material can be controlled by the fabrication condition. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2008
Claisen rearrangement induced by low‐energy collision of ESI‐generated, protonated benzyloxy indoles
Authors: Crotti Sara , Stella Laura , Munari Ilaria , Massaccesi Franco , Cotarca Livius , Forcato Massimiliano , Traldi Pietro 
Published: December 2007

AbstractThe Claisen rearrangement is a well‐known process occurring in condensed phase. In the gas‐phase protonated allyl phenyl ethers, propargyl phenyl ethers, and N‐allyl aniline produced by positive ion chemical ionization undergo Claisen rearrangement. This reaction has been observed even in the case of odd‐electron molecular ions. Phenyl allenyl ether molecular ions actually undergo Claisen rearrangement, producing intense [M − CO]+• ions. In this investigation, the behavior of protonated benzyloxy indole and some of its derivatives, obtained in electrospray conditions, is described. Low‐energy MS/MS experiments carried out on [M + H]+ species show CO loss and an unexpected water loss: both can be justified only by the occurrence of Claisen rearrangement. Deuterium labeling experiments confirm this mechanism. The influence of different substituents in the indole moiety is discussed. Copyright © 2007 John Wiley & Sons, Ltd.