bluuebunny/crossref_metadata_2025_split huggingface dataset:
Regulation of AP‐2 and apoptosis in developing eye in a vitamin A–deficiency model
Authors: Zhou Jian , Kochhar Devendra M. 
Published: January 2003

AbstractBACKGROUNDEye malformations induced by vitamin A deficiency (VAD) during pregnancy is a major part of the VAD syndrome. But the signaling role of retinoic acid (RA) in ocular tissues is poorly understood. The goal of this study was to determine the role of retinoic acid receptor (RAR) in the development of eye and the possible signaling pathway.METHODSTime‐pregnant mice were treated with 1 mg/kg dose of RAR antagonist AGN193109 (AGN) on 8 days postcoitum (dpc). Newborn mice and 18‐dpc embryos were used for phenotype studies. Embryonic eyes of 18 dpc were sectioned for histological study. With immunohistochemistry and TUNEL method, we monitored the alternation of AP‐2 expression and apoptotic cells in sections of 12‐ to 18‐dpc embryos.RESULTSTreatment with AGN resulted in severe craniofacial and eye malformations in virtually all exposed fetuses. The ocular abnormalities included severe defects in anterior segments such as focal corneal thickening and eversion, absence of corneal endothelium and anterior chamber, differentiation defects of lens, as well as defects in posterior segment such as persistent hyperplastic primary vitreous and retinal eversions. The percentage of AP‐2–positive cells in ocular tissues on 12, 14, and 18 dpc was significantly (P < 0.05) reduced in AGN‐treated eyes compared to control ones. Additionally, the number of apoptotic cell was significantly (P < 0.05) increased in AGN‐treated eyes.CONCLUSIONSThe blocking of RAR function can lead to ocular abnormalities that depict partial phenocopies of vitamin A–deficiency syndrome. Both an inhibition of expression of AP‐2 and an enhancement of cell death contribute to AGN‐induced ocular defects. Birth Defects Research (Part A) 67: 41–53, 2003. © 2003 Wiley‐Liss, Inc.
Modeling of scale‐down effects on the hydrodynamics of expanded bed adsorption columns
Authors: Fenneteau Frédérique , Aomari Hafida , Chahal Parminder , Legros Robert 
Published: January 2003

AbstractExpanded‐bed adsorption (EBA) is a technique for primary recovery of proteins starting from unclarified broths. This process combines centrifugation, concentration, filtration, and initial capturing of the proteins in a single step. An expanded bed (EB) is comparable to a packed bed in terms of separation performance but its hydrodynamics are that of a fluidized bed. Downstream process development involving EBA is normally carried out in small columns to minimize time and costs. Our purpose here is to characterize the hydrodynamics of expanded beds of different diameters, to develop scaling parameters that can be reliably used to predict separation efficiency of larger EBA columns. A hydrodynamic model has been developed which takes into account the radial liquid velocity profile in the column. The scale‐down effect can be characterized in terms of apparent axial dispersion, Daxl,app, and plate number, NEB, adapted for expanded bed. The model is in good agreement with experimental results obtained from 1‐ and 5‐cm column diameters with buffer solutions of different viscosities. The model and the experiments show an increase of apparent axial dispersion with an increase in column diameter. Furthermore, the apparent axial dispersion is affected by an increase in liquid velocity and viscos‐ ity. Supported by visual observations and predictions from the model, it was concluded that operating conditions (liquid viscosity and superficial velocity) resulting in a bed‐void fraction between 0.7 and 0.75 would provide the optimal separation efficiency in terms of NEB. © 2003 Wiley Periodicals, Inc. Biotechnol Bioeng 81: 790–799, 2003.
Simultaneous synthesis of enantiomerically pure (S)‐amino acids and (R)‐amines using coupled transaminase reactions
Authors: Cho Byung‐Kwan , Cho Ho Jung , Park Sung‐Hee , Yun Hyungdon , Kim Byung‐Gee 
Published: January 2003

AbstractFor the simultaneous synthesis of enatiomerically pure (S)‐amino acids and (R)‐amines from corresponding α‐keto acids and racemic amines, an α/ω‐transaminase coupled reaction system was designed using favorable reaction equilibrium shift led by ω‐transaminase reaction. Cloned tyrB, aspC and avtA, and ωtaA were co‐expressed in E. coli BL21(DE3) using pET23b(+) and pET24ma, respectively. The coupled reaction produced the (S)‐amino acids with 73–90% (> 99% eeS) of conversion yield and resolved the racemic amines with 83–99% eeR for 5 to 10 hours. In designing the coupled reactions in the cell, alanine and pyruvate were efficiently used in the cell as an amine donor for the alanine transaminase and an amino acceptor for the ω‐transaminase, respectively, resulting in an alanine‐pyruvate shuttling system. The common problem of the low equilibrium constant of the α‐transaminase can be efficiently overcome by the coupling with the ω‐transaminase. However, overcoming the product inhibition of ω‐transaminase by the ketone by‐product and increasing the decarboxylation rate of the oxaloacetate produced during the transaminase reaction become barriers to further improving the overall reaction rate and the yield of the coupled reactions. © 2003 Wiley Periodicals, Inc. Biotechnol Bioeng 81: 783–789, 2003.
Expression and secretion of the heterodimeric protein interleukin‐12 in plant cell suspension culture
Authors: Kwon T. H. , Seo J. E. , Kim J. , Lee J. H. , Jang Y. S. , Yang M. S. 
Published: January 2003

AbstractIt has been suggested that plant cell culture is the most suitable system for producing small‐to‐medium quantities of specialized, expensive, and high‐purity proteins. Here, we report that a heterodimeric protein, human interleukin‐12 (hIL‐12), was expressed and secreted into culture medium in a biologically active form. A transgenic plant expressing hIL‐12 was constructed by sexual crossing of plants that expressed each subunit of the protein. From a piece of transgenic plant, callus was induced and cell suspension culture was established. The biological activity and amount of hIL‐12 secreted into culture medium were analyzed using bioassays and ELISA. Analysis of cellular localization demonstrated that the protein was secreted into the culture medium together with its intrinsic signal peptide. © 2003 Wiley Periodicals, Inc. Biotechnol Bioeng 81: 870–875, 2003.
The impact of a self‐esteem group for people with eating disorders: an uncontrolled study
Authors: Newns Kathryn , Bell Lorraine , Thomas Sara 
Published: January 2003

AbstractLow self‐esteem is widely recognized as a predisposing, precipitating and maintaining factor in the aetiology of eating disorders. This paper examines the effectiveness of a self‐esteem group for women with eating disorders, delivered repeatedly over a 20‐month period. Forty‐one patients began and 33 completed the programme and both pre‐ and post‐measures. Eight were excluded from the final analysis as they were in concurrent psychological treatment. Outcome was assessed using standardized measures and records of symptom levels and drop‐out rates. Significant improvements in self‐esteem, depression, and eating attitudes were observed. It is concluded that a treatment focusing solely on self‐esteem can be beneficial in reducing eating disordered attitudes. Copyright © 2003 John Wiley & Sons, Ltd.
Developing basic training programmes: a case study illustration using the Delphi method in clinical psychology
Authors: Graham Louise F. , Milne Derek L. 
Published: January 2003

AbstractThe effectiveness of interventions in mental health depends on the competence of the therapists who deliver them and in turn on the training that they receive. For this training to be successful it is necessary for programmes to periodically review and develop their objectives, content and methods. In the present article we summarize the main pressures on training programmes to undertake such review and development cycles, detail one review method (the Delphi Technique), and present the results of a Delphi survey of the stakeholders (N = 43) associated with a clinical psychology training programme in the UK. The results indicated that the Delphi was conducted satisfactorily and that it can play a valuable role in defining how a training programme can be improved, based on reaching consensus about developments amongst the programme's stakeholders. Implications are drawn regarding the need for multiple measures, to complement the Delphi Technique as a way of developing training. Copyright © 2003 John Wiley & Sons, Ltd.
Allometric scaling and proportion regulation in the freshwater planarian Schmidtea mediterranea
Authors: Oviedo Néstor J. , Newmark Phillip A. , Sánchez Alvarado Alejandro 
Published: January 2003

AbstractThe regulation of scale and proportion in living organisms is an intriguing and enduring problem of biology. Regulatory mechanisms for controlling body size and proportion are clearly illustrated by the regeneration of missing body parts after amputation, in which the newly regenerated tissues ultimately attain a size that is anatomically congruent with the size of the rest of the organism. Understanding the molecular processes underpinning scaling would have deep consequences for our comprehension of tissue regeneration, developmental ontogeny, growth, and evolution. Although many theories have been put forward to explain this process, it is interesting that no satisfactory mechanistic explanation is currently available to explain scalar relationships. We chose to investigate the freshwater planarian, a commonly used model system for the study of metazoan regeneration, to delineate a strategy for the molecular dissection of scale and proportion mechanisms in metazoans. Here, we report on the cloning and discrete expression pattern of a novel planarian gene, which shares homology with the DEG/ENaC super‐family of sodium channels. We have named H.112.3c cintillo (“head ribbon” in Spanish) and present a strategy for using the expression of this gene to monitor scale and proportion regulation during regeneration, growth and degrowth in the freshwater planarian Schmidtea mediterranea. Developmental Dynamics 226:326–333, 2003.© 2003 Wiley‐Liss, Inc.
Electroporation as a tool to study in vivo spinal cord regeneration
Authors: Echeverri K. , Tanaka E.M. 
Published: January 2003

AbstractTailed amphibians such as axolotls and newts have the unique ability to fully regenerate a functional spinal cord throughout life. Where the cells come from and how they form the new structure is still poorly understood. Here, we describe the development of a technique that allows the visualization of cells in the living animal during spinal cord regeneration. A microelectrode needle is inserted into the lumen of the spinal cord and short rapid pulses are applied to transfer the plasmids encoding the green or red fluorescent proteins into ependymal cells close to the plane of amputation. The use of small, transparent axolotls permits imaging with epifluorescence and differential interference contrast microscopy to track the transfected cells as they contribute to the spinal cord. This technique promises to be useful in understanding how neural progenitors are recruited to the regenerating spinal cord and opens up the possibility of testing gene function during this process. Developmental Dynamics 226:418–425, 2003. © 2003 Wiley‐Liss, Inc.
Unique expression patterns of matrix metalloproteinases in regenerating newt limbs
Authors: Kato Tomoko , Miyazaki Koyomi , Shimizu‐Nishikawa Keiko , Koshiba Kazuko , Obara Masanobu , Mishima Hiromu K. , Yoshizato Katsutoshi 
Published: January 2003

AbstractThe process of regeneration of urodele limbs includes a drastic remodeling of extracellular matrices (ECMs) that is induced by matrix metalloproteinases (MMPs) and is thought to be one of the triggers of the regeneration. We studied this remodeling in limbs of Japanese newt, Cynops pyrrhogaster, by using five genes of newt MMPs (nMMPs) as probes: nMMP9, nMMP3/10‐a, nMMP3/10‐b, and nMMP13 that had been characterized previously, and nMMPe that was newly cloned in the present study. nMMPe was 502 amino acid residues long and showed a low homology to other known vertebrate MMPs. Reverse transcriptase‐polymerase chain reactions analysis localized the transcript of nMMPe in the apical epidermal cap (AEC) and the non–blastemal wound epidermis but not in the blastemal mesenchyme or the normal epidermis. Northern blot analysis localized the transcripts of nMMP9, nMMP3/10‐a, and nMMP13 in the bone of regenerating limbs, whereas those of nMMP3/10‐b in AEC. mRNA in situ hybridization experiments identified the nMMP‐expressing cells. nMMP9 gene was strongly expressed in chondrocytes of the cartilage of epiphysis. Of interest, basal cells of AEC, but not those of the normal skin, expressed nMMP3/10‐b intensely. Immunohistochemical analysis showed that the nMMP9 proteins synthesized by chondrocytes were secreted and distributed widely in the basement membrane of bone and ECMs of the amputation plane. These nMMPs characterized in the present study might cooperatively work to remodel ECMs of regenerating limbs. Developmental Dynamics 226:366–376, 2003. © 2003 Wiley‐Liss, Inc.
Identification of genes expressed during Xenopus laevis limb regeneration by using subtractive hybridization
Authors: King Michael W. , Nguyen Trent , Calley John , Harty Mark W. , Muzinich Michael C. , Mescher Anthony L. , Chalfant Chris , N'Cho Mathias , McLeaster Kevin , McEntire Jacquelyn , Stocum David , Smith Rosamund C. , Neff Anton W. 
Published: January 2003

AbstractSuppression polymerase chain reaction–based subtractive hybridization was used to identify genes that are expressed during Xenopus laevis hindlimb regeneration. Subtractions were done by using RNAs extracted from the regeneration‐competent stage (stage 53) and regeneration‐incompetent stage (stage 59) of limb development. Forward and reverse subtractions were done between stage 53 7‐day blastema and stage 53 contralateral limb (competent stage), stage 59 7‐day pseudoblastema and stage 59 contralateral limb (incompetent stage), and stage 53 7‐day blastema and stage 59 7‐day pseudoblastema. Several thousand clones were analyzed from the various subtracted libraries, either by random selection and sequencing (1,920) or by screening subtracted cDNA clones (6,150), arrayed on nylon membranes, with tissue‐specific probes. Several hundred clones were identified from the array screens whose expression levels were at least twofold higher in experimental tissue vs. control tissue (e.g., blastema vs. limb) and selected for sequencing. In addition, primers were designed to assay several of the randomly selected clones and used to assess the level of expression of these genes during regeneration and normal limb development. Approximately half of the selected clones were differentially expressed, as expected, including several that demonstrate blastema‐specific enhancement of expression. Three distinct categories of expression were identified in our screens: (1) clones that are expressed in both regeneration‐competent blastemas and ‐incompetent pseudoblastemas, (2) clones that are expressed at highest levels in regeneration‐competent blastemas, and (3) clones that are expressed at highest levels in regeneration‐incompetent pseudoblastemas. Characterizing the role of each of these three categories of genes will be important in furthering our understanding of the process of tissue regeneration. Developmental Dynamics 226:398–409, 2003. © 2003 Wiley‐Liss, Inc.
Induction of tenascin‐C by tumor‐specific EWS‐ETS fusion genes
Authors: Watanabe Goichi , Nishimori Hiroyuki , Irifune Hideto , Sasaki Yasushi , Ishida Setsuko , Zembutsu Hitoshi , Tanaka Toshihiro , Kawaguchi Satoshi , Wada Takuro , Hata Jun‐ichi , Kusakabe Moriaki , Yoshida Koichi , Nakamura Yusuke , Tokino Takashi 
Published: January 2003

AbstractEwing sarcoma (ES) and peripheral primitive neuroectodermal tumors (PNETs) are associated with a chromosomal translocation resulting in a fusion of the amino‐terminus of EWS with the DNA‐binding domain of an ETS transcription factor (most commonly FLI1 or ERG). Although previous reports suggested that these chimera proteins would act as aberrant transcription factors, their downstream targets have not been fully elucidated. To identify downstream targets of these EWS‐ETS fusion proteins, we introduced EWS‐ETS fusion constructs into a human fibrosarcoma cell line, HT‐1080, by retroviral transduction. Here we report that Tenascin‐C (TNC) is induced to a significantly higher level in cells expressing EWS‐ETSs than in cells expressing normal ETSs. Furthermore, through use of an antisense cDNA expression vector we show that expression of endogenous TNC mRNA and protein were reduced coordinately with attenuation of EWS‐FLI1 fusion protein expression. A chromatin immunoprecipitation assay showed direct interaction between the TNC promoter and the EWS‐FLI1 fusion protein in vivo. In addition, a luciferase reporter assay revealed that EWS‐ETSs upregulated the TNC gene through four ETS binding sites in the TNC promoter. High levels of TNC expression were observed in a subset of ES cell lines (3 of 6) and primary tumors (4 of 6). Together with previous studies showing that TNC expression is involved in the invasive and malignant phenotype of several tumor types, our data suggest that the oncogenic effect of EWS‐ETS may be mediated in part by upregulating of TNC expression. © 2003 Wiley‐Liss, Inc.
Serrated adenomas and mixed polyposis caused by a splice acceptor deletion in the mouse Smad4 gene
Authors: Hohenstein Peter , Molenaar Lia , Elsinga Joyce , Morreau Hans , van der Klift Heleen , Struijk Ada , Jagmohan‐Changur Shantie , Smits Ron , van Kranen Henk , van Ommen Gert‐Jan B. , Cornelisse Cees , Devilee Peter , Fodde Riccardo 
Published: January 2003

AbstractSerrated adenomas, hyperplastic polyps, and admixed hyperplastic/adenomatous polyps form a distinct group of colorectal tumors, the molecular genetic basis of which is still poorly understood. We describe a novel mouse model for serrated adenomas and mixed polyposis, here referred to as Sad (serrated adenomas), caused by a spontaneously risen splice site mutation in the murine Smad4 gene. The Sad chromosomal region was identified by genetic linkage and loss of heterozygosity (LOH) analysis. Subsequently, several candidate genes were investigated by expression and mutation analysis. By use of genetic linkage and LOH analysis, we mapped the Sad candidate to mouse chromosome 18, 44–48 cM, syntenic to human chromosome band 18q21. Within this chromosomal interval, the Smad2, Smad4, and Smad7 genes were analyzed for the presence of a disease‐causing mutation in affected animals. A single nucleotide (nt) deletion was identified in the intron 5/exon 6 splice acceptor site of the Smad4 gene. The single base deletion results in a frameshift and an early termination codon through activation of a cryptic splice site 4 nt downstream in exon 6. The resulting mRNA is unstable, and the Sad mutation is thus likely to represent a null allele. Identification of a Smad4 mutation in the Sad mouse model provides further support for the involvement of the Smad genes, and thus the TGFB pathway, in the serrated/hyperplastic route to colorectal cancer. © 2003 Wiley‐Liss, Inc.
Morphogenesis of typical winter and summer snow surface patterns in a continental alpine environment
Authors: Herzfeld Ute C. , Mayer Helmut , Caine Nel , Losleben Mark , Erbrecht Tim 
Published: January 2003

AbstractSnow surface roughness is an important variable in the study of surface–atmosphere exchanges, including the investigation of snow melt at several scales, meltwater production and meltwater flux, wind transport and erosion in winter. In this paper the morphogenesis of the snow surface in winter and in summer is investigated both phenomenologically and quantitatively. For the first time, snow surface roughness and microtopography is measured spatially, using the Glacier Roughness Sensor (GRS), an instrument developed especially for this purpose. Data are analysed by application of geostatistical characterization and classification methods. Parameters that are useful as snow surface descriptors are defined and extracted from vario functions of first and second order, which are calculated for snow‐surface‐roughness data.As a result of the geostatistical analysis, characteristics of morphogenetic processes of the winter and summer snow surface are derived. Characteristic parameters are given for suncups (summer) and sastrugi (winter) and their development stages, as well as quantitative discriminators between these forms, which may facilitate automation of snow surface classification. As an application, the interaction of environmentally induced processes and self‐organizational processes is analysed. Copyright © 2003 John Wiley & Sons, Ltd.
Kinetic analysis of the interactions between Troponin C (TnC) and Troponin I (TnI) binding peptides: evidence for separate binding sites for the ‘structural’ N‐terminus and the ‘regulatory’ C‐terminus of TnI on TnC
Authors: Tripet Brian , De Crescenzo Gregory , Grothe Suzanne , O'Connor‐McCourt Maureen , Hodges Robert S. 
Published: January 2003

AbstractThe Ca2+/Mg2+‐dependent interactions between TnC and TnI play a critical role in regulating the ‘on’ and ‘off’ states of muscle contraction as well as maintaining the structural integrity of the troponin complex in the off state. In the present study, we have investigated the binding interactions between the N‐terminus of TnI (residues 1–40 of skeletal TnI) and skeletal TnC in the presence of Ca2+ ions, Mg2+ ions and in the presence of the C‐terminal regulatory region peptides: TnI96–115, TnI96–131 and TnI96–139. Our results show the N‐terminus of TnI can bind to TnC with high affinity in the presence of Ca2+ or Mg2+ ions with apparent equilibrium dissociation constants of K = 48 nM and K = 29 nM. The apparent association and dissociation rate constants for the interactions were, kon = 4.8 × 105 M
−1 s−1, 3.4 × 105 M
−1 s−1 and koff = 2.3 × 10−2 s−1, 1.0 × 10−2 s−1 for TnC(Ca2+) and TnC(Mg2+) states, respectively. Competition studies between each of the TnI regions and TnC showed that both TnI regions can bind simultaneously to TnC while native gel electrophoresis and SEC confirmed the formation of stable ternary complexes between TnI96–139 (or TnI96–131) and TnC–TnI1–40. Further analysis of the binding interactions in the ternary complex showed the binding of the TnI regulatory region to TnC was critically dependent upon the presence of both TnC binding sites (i.e. TnI96–115 and TnI116–131) and the presence of Ca2+. Furthermore, the presence of TnI1–40 slightly weakened the affinity of the regulatory peptides for TnC. Taken together, these results support the model for TnI–TnC interaction where the N‐terminus of TnI remains bound to the C‐domain of TnC in the presence of high and low Ca2+ levels while the TnI regulatory region (residues 96–139) switches in its binding interactions between the actin‐tropomyosin thin filament and its own sites on the N‐ and C‐domain of TnC at high Ca2+ levels, thus regulating muscle contraction. Copyright © 2003 John Wiley & Sons, Ltd.