bluuebunny/crossref_metadata_2025_split huggingface dataset:
RNA amplification and transcriptional profiling for analysis of stem cell populations
Authors: Gallardo Teresa D. , Hammer Robert E. , Garry Daniel J. 
Published: October 2003

AbstractAs stem cells constitute a rare cell pool, a global analysis of gene expression is typically not possible. Here, we use a T7‐based RNA amplification method combined with high‐density oligonucleotide array technology to analyze gene expression. We isolated RNA from ES cells (100–100,000 cells), subjected them to two rounds of amplification, and compared each sample using microarray analysis. RNA isolation and amplification was highly reproducible and sensitive for the analysis of low abundant transcripts. Greater than 93% of the transcripts expressed were changed less than 2‐fold when comparing the results of amplified RNA (100 cells to 100,000 cells) to unamplified RNA (isolated from 1,000,000 cells). This transcriptional analysis resulted in minimal skewing of gene expression. Using this technology, we analyzed the genetic programs of ES cells, STO feeder cells, and adult cardiomyocytes. We conclude that these technologies can be applied to the analysis of the genetic programs of rare cell populations and ultimately this analysis will enhance our understanding of the regulatory mechanisms of stem cell populations. genesis 37:57–63, 2003. © 2003 Wiley‐Liss, Inc.
Maternal inheritance of Cre activity in a Sox2Cre deleter strain
Authors: Hayashi Shigemi , Tenzen Toyoaki , McMahon Andrew P. 
Published: October 2003

AbstractSummary: The Sox2 gene is expressed in several undifferentiated cell types. In an earlier study we described a Sox2Cre transgene that mediates epiblast‐specific Cre‐mediated modification of gene activity in the embryo. Here we report that this transgene is active in the female germline. Consequently, all offspring that arise from female mice heterozygous for the Sox2Cre transgene have demonstrable Cre activity irrespective of whether they inherit the transgene itself. Maternal inheritance of Cre activity allows the efficient modification of gene activity for functional analysis. genesis 37:51–53, 2003. © 2003 Wiley‐Liss, Inc.
Assessing the contributions of gene products to the form‐shaping events of neurulation: A transgenic approach in chick
Authors: Colas Jean‐François , Schoenwolf Gary C. 
Published: October 2003

AbstractSummary: Most of our current knowledge on the tissue and cellular basis of neurulation in amniotes has been gained using the chick embryo as an experimental model system. Gene manipulation during chick neurulation has been difficult, greatly limiting our ability to assess the contribution of gene products to the tissue and cellular behaviors of neurulation. Using electroporation, we have developed a simple and reliable method for expressing transgenes in the ectoderm of the neural folds of chick embryos developing in whole‐embryo culture. Sense‐ or antisense‐expressing plasmids are electroporated, resulting in gain or loss of gene function, respectively. The morphogenesis of transgenic tissues was compared to the morphogenesis of contralateral wildtype tissues as neurulation was taking place. As a proof of principle, we present a functional analysis of the chick gene encoding Cartilage Linking Protein 1 (CRTL1), identified as a candidate neurulation gene using subtractive hybridization. This experimental approach provides a much‐needed innovation for studying the mechanisms by which genes influence neurulation and reveals here important contributions of CRTL1 to the formation of the neural folds. genesis 37:64–75, 2003. © 2003 Wiley‐Liss, Inc.
Microbubble‐enhanced sonoporation: Efficient gene transduction technique for chick embryos
Authors: Ohta Sho , Suzuki Kentaro , Tachibana Katsuro , Yamada Gen 
Published: October 2003

AbstractThe gene transduction technique is a useful method to study gene functions that underlie vertebrate embryogenesis. In this study, a new gene transduction technique is reported using microbubble‐enhanced sonoporation (hereafter referred to as sonoporation) to achieve ectopic and transient gene expression for several embryonic organs including embryonic chick limb bud mesenchymes. The technique proposed in this study has the advantages of 1) relatively simple gene transduction procedures, and 2) efficient exogenous gene transduction and expression with lower damages to embryos. Green fluorescent protein (GFP) or LacZ was misexpressed in limb bud mesenchymes by sonoporation, with the introduced expression transiently detected in the injected sites. Most of the transduced chick embryos survived without showing significant embryonic abnormalities or cell death after sonoporation. To demonstrate its efficacy for assessing the effect of transient gene transduction, the Shh (sonic hedgehog) was transduced into the developing chick limb bud. The transduced limb bud displayed limb malformations including partial digit duplication. Advantages and possible future applications in relation to this method are discussed. genesis 37:91–101, 2003. © 2003 Wiley‐Liss, Inc.
Analysis of a null mutation in the Drosophila splicing regulator Tra2 suggests its function is restricted to sexual differentiation
Authors: Unni Emmanual , Su Shihuang , Mattox William 
Published: October 2003

AbstractTra2 is a regulator of pre‐mRNA splicing and a key component of the Drosophila somatic sex determination pathway. Functional orthologs of this protein are thought to perform nonsex‐specific functions essential for viability in both vertebrates and nematodes. Although Drosophila Tra2 is expressed throughout the soma of both sexes, studies on it have focused only on the sex‐specific phenotypes of known viable alleles. Here we show that that widely used tra2 mutant alleles have residual activity and are not suitable for evaluating its effect on viability. To test whether Tra2 has an essential role in development, we generated a transposon‐induced deletion in critical coding sequences. We find that tra2 deletion adults can survive as well as their heterozygous siblings. Thus, in contrast to other organisms, Tra2 is not required in Drosophila for general viability under laboratory conditions. genesis 37:76–83, 2003. © 2003 Wiley‐Liss, Inc.
Pbx1 is essential for adrenal development and urogenital differentiation
Authors: Schnabel Catherine A. , Selleri Licia , Cleary Michael L. 
Published: October 2003

AbstractPbx1 encodes a TALE (three amino acid loop extension) class homeodomain protein that participates in multimeric transcriptional complexes to regulate developmental gene expression. Previous studies demonstrate a critical role for Pbx1 as a developmental regulator whose absence results in embryonic lethality and multiple tissue and organ system abnormalities. Here we report a requirement for Pbx1 in the differentiation of urogenital organs, where Pbx1 is widely expressed in mesenchymal tissues. The complete lack of adrenal glands and formation of gonads displaying rudimentary sexual differentiation correlated with decreased cellular proliferation in Pbx1‐/‐ genital ridges. Furthermore, expression of steroidogenic factor‐1 (SF‐1), a nuclear receptor essential for adrenal organogenesis, was reduced to minimal levels in Pbx1 mutants, indicating an upstream function for Pbx1 in adrenocortical development. Finally, loss of Pbx1 markedly reduces urogenital ridge outgrowth and results in impaired differentiation of the mesonephros and kidneys and the absence of Müllerian ducts. These findings establish a Pbx1‐dependent pathway that regulates the expansion of SF‐1 positive cells essential for adrenal formation and gonadal differentiation and demonstrate an early requirement for Pbx1 in urogenital development. genesis 37:123–130, 2003. © 2003 Wiley‐Liss, Inc.
Cardiac electrophysiological phenotypes in postnatal expression of Nkx2.5 transgenic mice
Authors: Wakimoto Hiroko , Kasahara Hideko , Maguire Colin T. , Moskowitz Ivan P.G. , Izumo Seigo , Berul Charles I. 
Published: October 2003

AbstractNkx2.5 is a conserved homeodomain (HD) containing a transcription factor essential for early cardiac development. We generated several mutations modeling some patients with congenital heart disease. Transgenic mice (tg) expressing the wildtype Nkx2.5 under β‐myosin heavy chain (MHC) promoter died during the embryonic stage. However, tg mice expressing this mutation under β‐MHC promoter (β‐MHC‐TG(I183P)), the wildtype Nkx2.5 (α‐MHC‐TG(wild)), and a putative transcriptionally active mutant (carboxyl‐terminus deletion, α‐MHC‐TG(ΔC)) under α‐MHC promoter showed postnatal lethal heart failure. Given the profound atrioventricular conduction abnormalities we recently demonstrated in β‐MHC‐TG(I183P) mice, the aim of this study was to determine whether α‐MHC‐TG(wild) and α‐MHC‐TG(ΔC) mutant mice display similar cardiac electrophysiological phenotypes. Surface ECG recordings and in vivo electrophysiology studies were performed in α‐MHC‐TG(wild) mice and controls at 6 weeks of age, and in α‐MHC‐TG(ΔC) mice and controls at 10 weeks of age. Ambulatory ECG recordings in α‐MHC‐TG(wild) and controls were obtained using an implantable radiofrequency telemetry system. PR prolongation and atrioventricular nodal dysfunction were detected in α‐MHC‐TG(wild) and α‐MHC‐TG(ΔC) mice. Bradycardia and prolonged PR interval were seen in ambulatory ECG of α‐MHC‐TG(wild) mice compared to controls. Several α‐MHC‐TG(wild) mice died of bradycardia. Fetal and neonatal mutant Nkx2.5 expression causes severe cardiac conduction failure. Postnatal overexpression of nonmutant (wild) Nkx2.5 also causes conduction abnormalities, although the onset is after the neonatal stage. Bradycardia and AV conduction failure may contribute to the lethal heart failure and early mortality. genesis 37:144–150, 2003. © 2003 Wiley‐Liss, Inc.
Tyrosinase‐Cre mice for tissue‐specific gene ablation in neural crest and neuroepithelial‐derived tissues
Authors: Tonks Ian D. , Nurcombe Victor , Paterson Carol , Zournazi Anna , Prather Catherine , Mould Arne W. , Kay Graham F. 
Published: October 2003

AbstractThis study describes the derivation of two new lines of transgenic mice that express Cre recombinase under the control of tyrosinase transcriptional elements. To determine the suitability of the Tyrosinase‐Cre transgene for tissue‐specific gene ablation studies, a fate map of Cre expression domains was determined using the Z/AP reporter strain. It was shown that Cre‐expressing cells contribute to a wide array of neural crest and neuroepithelial‐derived lineages. The melanocytes of the harderian gland and eye choroid, sympathetic cephalic ganglia, leptomeninges of the telencephalon, as well as cranial nerves (V), (VII), and (IX) are derived either fully or partly from Cre‐expressing cephalic crest. The cells contributing to the cranial nerves were the first to exhibit Cre expression at E10.5 as they were migrating into the branchial arches. The melanocytes, chromaffin cells of the adrenal medulla, and dorsal root ganglia are derived from trunk neural crest that either express Cre or were derived from Cre‐expressing precursors. An array of brain tissue including the basal forebrain, hippocampus, olfactory bulb, and the granule cell layer of the lateral cerebellum, as well as the retinal pigmented epithelium and glia of the optic nerve originate from Cre‐expressing neuroepithelial cells. genesis 37:131–138, 2003. © 2003 Wiley‐Liss, Inc.
Static–dynamic friction transition of FRP esthetic orthodontic wires on various brackets by suspension‐type friction test
Authors: Suwa N. , Watari F. , Yamagata S. , Iida J. , Kobayashi M. 
Published: October 2003

AbstractA new testing apparatus for the measurement of frictional properties was designed and the frictional coefficients were obtained and compared with each other in various combinations of brackets and orthodontic wires, including esthetic fiber‐reinforced plastic (FRP) wire that was especially designed and manufactured. Three kinds of wires (stainless steel, nickel–titanium, and FRP) and four brackets (single‐crystal alumina, polycrystalline alumina, polycarbonate, and stainless steel) were used. The testing was done under dry and wet conditions. The friction testing equipment was designed to attach the bracket to a C‐shaped bar suspended with a variable mass, and sliding along a fixed wire. The transition between static and dynamic friction was measured as a breakaway force, with the use of a universal test machine. In addition to material properties, this testing fixture eliminates geometrical factors, such as the rotational moment at the edge of the bracket slot, deflection of the orthodontic wire, and tension of the ligature wire. Nearly ideal frictional properties between materials are obtained. The frictional properties of FRP wire were similar to those of metal wires on all brackets, except the polycrystalline alumina bracket. The frictional coefficient between the polycrystalline ceramic bracket and FRP wire was larger than that of other combinations. There was little difference in frictional coefficients between dry and wet conditions. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 67B: 765–771, 2003
Control of material stiffness during degradation for constructs made of absorbable polymer fibers
Authors: Dürselen Lutz , Dauner Martin , Hierlemann Helmut , Planck Heinrich , Ignatius Anita , Claes Lutz E. 
Published: October 2003

AbstractAugmentation devices for cruciate ligament surgery should provide gradually decreasing mechanical properties with a half‐time strength of at least 6 months to temporarily protect healing tendon grafts or sutured ligaments against high tensile loads during the postoperative healing period. The absorbable material of choice that shows such slow degradation kinetics is poly(L‐lactide). However, previous studies have shown that poly(L‐lactide) fulfills the requirement of a long half‐time strength, while the corresponding stiffness decreases at a much slower rate. An augmentation stiffness that does not change much versus time cannot provide a gradual increase in graft load, which is important to stimulate the orientation of the collagenous tissue. Therefore a new augmentation device was designed, which should decrease both in strength and stiffness during degradation. The cord was braided out of two fibers made of poly(L‐lactide) and poly(L‐lactide‐co‐glycolide), which degrade at different rates. The cord prototype was degraded in vitro and the rupture force and stiffness was tested at eight different time points up to 60 weeks. The initial rupture force and stiffness was 522.7 ± 2.8 N and 104.1 ± 3.8 N/%, respectively. Both strength and stiffness decreased continuously with a half‐time strength of 18 weeks and a half‐time stiffness of 39 weeks. The gradually decreasing stiffness was achieved by the breakdown of the faster‐degrading fiber component made of poly(L‐lactide‐co‐glycolide). Thus the new augmentation device can provide a continuous increase of forces in a tendon graft or in a healing ligament. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 67B: 697–701, 2003
Electrospun nanofibrous polyurethane membrane as wound dressing
Authors: Khil Myung‐Seob , Cha Dong‐Il , Kim Hak‐Yong , Kim In‐Shik , Bhattarai Narayan 
Published: October 2003

AbstractProduced via electrospinning, polyurethane membrane, which has a unique property, has been of interest in medical fields. Electrospinning is a process by which nanofibers can be produced by an electrostatically driven jet of polymer solution. Electrospun fibers are collected in the form of membranes. The porous structured electrospun membrane is particularly important for its favorable properties: it exudates fluid from the wound, does not build up under the covering, and does not cause wound desiccation. The electrospun nanofibrous membrane shows controlled evaporative water loss, excellent oxygen permeability, and promoted fluid drainage ability, but still it can inhibit exogenous microorganism invasion because its pores are ultra‐fine. Histological examination indicates that the rate of epithelialization is increased and the dermis becomes well organized if wounds are covered with electrospun nanofibrous membrane. This electrospun membrane has potential applications for wound dressing based upon its unique properties. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 67B: 675–679, 2003
Generation of narrowly distributed ultra‐high‐molecular‐weight polyethylene particles by surface texturing techniques
Authors: Fang Hsu‐Wei , Hsu Stephen M. , Sengers Jan V. 
Published: October 2003

AbstractUltra‐high‐molecular‐weight polyethylene (UHMWPE) wear particles have been recognized as the cause of aseptic loosening in total joint replacement. Macrophage phagocytosis of wear particles induces human biological/physiological responses which eventually lead to bone resorption and osteolysis. However, the dependence of these reactions on the size and shape of the particles has not been elucidated and is not understood. This article describes a procedure to generate narrowly distributed UHMWPE particles of controlled size and shape through surface texturing by microfabrication. The textured surface is then used to rub against the polymer pins to produce wear particles in water. The surface texture produces elongated particles or equiaxed particles by design. The distribution of the particles, due to the surface‐texture control, is quite narrow as compared with randomly produced surfaces. With this technique, we are able to generate UHMWPE wear particles of different size and shape within phagocytosable and nonphagocytosable populations for biological response studies. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 67B: 741–749, 2003
Ion release and chromosomal damage from total hip prostheses with metal‐on‐metal articulation
Authors: Massè A. , Bosetti M. , Buratti C. , Visentin O. , Bergadano D. , Cannas M. 
Published: October 2003

AbstractA prospective multicentric study was carried out in patients having metal‐on‐metal METASUL components (Sulzer Medica, Winterthur, Switzerland) in order to check the following null hypotheses: H1: The concentration of Co, Cr, Ni, and Mb in blood and urine is not modified by the implant of a hip prosthesis with METASUL components at 6 months. H2: The incidence of markers of chromosomal damage [sister chromatid exchanges (SCEs) and micronuclei (Mni)] in lymphocytes is not modified by the implant of METASUL components at 6 months. H3: The concentrations of Co, Cr, Ni, and Mb in blood and urine did not correlate with the incidence of the markers of chromosomal damage. The measurements showed a 2‐fold increase of Co in blood, a 10‐fold increase of Co in urine, a 1.5‐fold increase of Cr in the blood, and a 3‐fold increase of Cr in the urine at a follow‐up of 6 months from the operation; there was also a significant increase in the Ni blood concentration at the 7 day checkup. The study cohort did not show any modification in the frequency of markers of chromosomal damage in the peripheral lymphocytes at any of the observation times. The amount of the SCEs and Mni recorded at all the observation times did not correlate with each other or with any of the ion levels measured in the blood and in the urine. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 67B: 750–757, 2003
Heat shock response: hsp70 in environmental monitoring
Authors: Mukhopadhyay Indranil , Nazir Aamir , Saxena D. K. , Chowdhuri D. Kar 
Published: October 2003

AbstractHeat shock proteins (Hsps) are a ubiquitous feature of cells in which these proteins cope with stress‐induced denaturation of other proteins. Among the different families of Hsps, the 70 kDa family (hsp70) is the most highly conserved and has been most extensively studied. Apart from their primary role in cellular defense under stress condition, a number of studies in recent years have shown the immense potential of hsp70 in pollution monitoring using even transgenic approach both in vivo and in vitro. This article reviews the recent developments in the widespread application of hsp70 in environmental risk assessment. © 2003 Wiley Periodicals, Inc. J Biochem Mol Toxicol 17:249–254, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/jbt.10086
Two cinnamate derivatives produce similar alteration in mRNA expression and activity of antioxidant enzymes in rats
Authors: Lee Mi‐Kyung , Park Eun‐Mi , Bok Song‐Hae , Jung Un Ju , Kim Ji‐Young , Park Yong Bok , Huh Tae‐Lin , Kwon Oh‐Shin , Choi Myung‐Sook 
Published: October 2003

AbstractCinnamate is a widespread secondary metabolite of phenolic compound synthesized by plants for defensive purposes. The current study was designed to investigate the effect of two structurally related cinnamate derivatives, 4‐hydroxycinnamate and 3‐(4‐hydroxyphenyl)propionic acid (HPP), on the mRNA expression and activity of antioxidant enzymes in high‐cholesterol‐fed rats. Male rats were fed a 1 g/100 g high‐cholesterol diet with supplements of either 4‐hydroxycinnamate or HPP (0.135 mmol/100 g diet) for 6 weeks. The plasma paraoxonase activity was found to be higher in the cinnamate‐derivative‐supplemented groups than in the control group. The erythrocyte superoxide dismutase (SOD) and catalase (CAT) activities, plus glutathione (GSH) level, were all significantly higher in the 4‐hydroxycinnamate‐ and HPP‐supplemented groups than in the control group. However, both 4‐hydroxycinnamate and HPP supplementation significantly lowered the hepatic activities and mRNA expression of CAT and glutathione peroxidase (GSH‐Px) compared to the control group. The hepatic mRNA expression and activity of SOD did not differ between the groups. The hepatic thiobarbituric acid reactive substances (TBARS) level was significantly lowered by the 4‐hydroxycinnamate and HPP supplementation. Accordingly, these results indicate that supplementation by 4‐hydroxycinnamate and HPP would seem to enhance the antioxidative defense of erythrocyte. Both HPP and 4‐hydroxycinnamate would appear to be beneficial in improving the function of antioxidative enzymes on a molecular level in high‐cholesterol‐fed rats. © 2003 Wiley Periodicals, Inc. J Biochem Mol Toxicol 17:255–262, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/jbt.10087