bluuebunny/crossref_metadata_2025 huggingface dataset:
Sensitive cytologic criteria for the identification of follicular variant of papillary thyroid carcinoma in fine‐needle aspiration biopsy
Authors: Wu Howard Her‐Juing , Jones Jennifer N. , Grzybicki Dana Marie , Elsheikh Tarik M.
Published: October 2003

The cytologic diagnosis of follicular variant of papillary thyroid carcinoma (FVPTC) can be extremely challenging and may be associated with false negative diagnoses. The purpose of this study was to determine the minimal cytologic criteria needed to identify FVPTC. We examined sixty‐nine fine‐needle aspiration (FNA) cases, processed with Diff‐Quik and Papanicolaou stains, that were either diagnostic or suspicious of FVPTC. All cases had histologic confirmation. These cases included 29 FVPTC, 18 classic papillary thyroid carcinoma (PTC), 17 follicular neoplasm (6 adenomas, 10 carcinomas, 1 neoplasm NOS), 2 lymphocytic thyroiditis and 3 nodular goiter. Seven of the most commonly cited cytomorphologic features, including flat syncytial sheets, nuclear enlargement, fine chromatin, nuclear grooves, nuclear pseudoinclusions, and amount of colloid and cytoplasm, were evaluated. A diffuse distribution of fine chromatin, nuclear grooves, and colloid was seen more often in FVPTC than in follicular neoplasm (p<0.01). The combination of flat/syncytial sheets, nuclear enlargement, and fine chromatin was observed in all our cases of FVPTC, and is therefore considered a sensitive marker in detecting FVPTC. Logistic regression analysis revealed colloid to be the only positive predictor in favor of FVPTC over classic PTC. Diagn. Cytopathol. Diagn. Cytopathol. 2003;29:262–266. © 2003 Wiley‐Liss, Inc.
Hybrid LES‐RANS modelling: a one‐equation SGS model combined with a k–ω model for predicting recirculating flows
Authors: Davidson L. , Peng S. H.
Published: October 2003

A hybrid LES‐RANS modelling approach is proposed. RANS is used in the near wall regions (y+≲60), and the turbulence is modelled with a k–ω model. LES is used in the remaining part of the flow, and the SGS turbulence is modelled with a one‐equation ksgs model. The same continuity and momentum equations are solved throughout the domain, the only difference being that the turbulent viscosity is taken from the k–ω model in the RANS region, and from the one‐equation ksgs model in the LES region. The new modelling approach is applied to two incompressible flow test cases. They are fully developed flow in a plane channel and the flow over a 2D‐hill in a channel. Copyright © 2003 John Wiley & Sons, Ltd.
Computation of an unsteady complex geometry flow using novel non‐linear turbulence models
Authors: Tucker Paul G. , Liu Yan , Chung Yongmann M. , Jouvray Alex
Published: October 2003

Non‐linear zonal turbulence models are applied to an unsteady complex geometry flow. These are generally found to marginally improve predicted turbulence intensities. However, relative to linear models, convergence is mostly difficult to achieve. Clipping of some non‐linear Reynolds stress components is required along with velocity field smoothing or alternative measures. Smoothing is naturally achieved through multilevel convergence restriction operators. As a result of convergence difficulties, generally, non‐linear model computational costs detract from accuracy gains. For standard Reynolds stress model results, again computational costs are prohibitive. Also, mean velocity profile data accuracies are found worse than for a simple mixing length model. Of the non‐linear models considered, the explicit algebraic stress showed greatest promise with respect to accuracy and stability. However, even this shows around a 30% error in total (the sum of turbulence and unsteadiness) intensity. In strong contradiction to measurements the non‐linear and Reynolds models predict quasi‐steady flows. This is probably a key reason for the total intensity under‐predictions. Use of LES in a non‐linear model context might help remedy this modelling aspect. Copyright © 2003 John Wiley & Sons, Ltd.
A parallel implementation of the fast multipole method for Maxwell's equations
Authors: Havé Pascal
Published: October 2003

It is well known that the resolution of Maxwell equations may provide large dense matrices, being thus a computer intensive problem. Even small problems require a huge amount of memory to manipulate matrices during the O(N3) involved operations.

The fast multipole method enables to compress and approximate matrices. Coupled with an iterative resolution of the linear system the complexity reduces to O(Niter N log N) operations.

In order to use multiprocessors machine and to reduce computation times, we propose here a parallel implementation of the fast multiple method. This article relates our first results, as well as the difficulties encountered. Copyright © 2003 John Wiley & Sons, Ltd.
Numerical techniques for flow problems with singularities
Authors: Farrell Paul A. , Hegarty Alan F. , Miller John J. H. , O'Riordan Eugene , Shishkin Grigorii I.
Published: October 2003

This paper deals with grid approximations to Prandtl's boundary value problem for boundary layer equations on a flat plate in a region including the boundary layer, but outside a neighbourhood of its leading edge. The perturbation parameter ε= Re‐1 takes any values from the half‐interval (0,1] ; here Re is the Reynolds number. To demonstrate our numerical techniques we consider the case of the self‐similar solution. By using piecewise uniform meshes, which are refined in a neighbourhood of the parabolic boundary layer, we construct a finite difference scheme that converges ε‐uniformly. We present the technique of experimental substantiation of ε‐uniform convergence for both the numerical solution and its normalized (scaled) difference derivatives, outside a neighbourhood of the leading edge of the plate. By numerical experiments we demonstrate the efficiency of numerical techniques based on the fitted mesh method. We discuss also the applicability of fitted operator methods for the numerical approximation of the Prandtl problem. It is shown that the use of meshes refined in the parabolic boundary layer region is necessary for achieving ε‐uniform convergence. Copyright © 2003 John Wiley & Sons, Ltd.
Computing realistic Reynolds‐uniform error bounds for discrete derivatives of flow velocities in the boundary layer for Prandtl's problem
Authors: Farrell Paul A. , Hegarty Alan F. , Miller John J. H. , O'Riordan Eugene , Shishkin Grigorii I.
Published: October 2003

In this paper, we describe an experimental error analysis technique for computing realistic values of the parameter‐uniform order of convergence and error constant in the maximum norm associated with a parameter‐uniform numerical method for solving singularly perturbed problems. We then employ this technique to compute Reynolds‐uniform error bounds in the maximum norm for appropriately scaled discrete derivatives of the numerical solutions generated by a fitted‐mesh upwind finite‐difference method applied to Prandtl's problem arising from laminar flow past a thin flat plate. Here the singular perturbation parameter is the reciprocal of the Reynolds number. This illustrates the efficiency of the technique for finding realistic parameter‐uniform error bounds in the maximum norm for numerical approximations to scaled derivatives of solutions to problems in cases where no theoretical error analysis is available. Copyright © 2003 John Wiley & Sons, Ltd.
A Reynolds‐uniform numerical method for Prandtl's boundary layer problem for flow past a wedge
Authors: Butler J. S. , Miller John J. H. , Shishkin Grigorii I.
Published: October 2003

In this paper, we deal with Prandtl's boundary layer problem for incompressible laminar flow past a wedge. When the Reynolds number is large the solution of this problem has a parabolic boundary layer. We construct a direct numerical method for computing approximations to the solution of this problem using a piecewise uniform fitted mesh technique appropriate to the parabolic boundary layer. We use the numerical method to approximate the self‐similar solution of Prandtl's problem in a finite rectangle excluding the leading edge of the wedge, which is the source of an additional singularity caused by incompatibility of the problem data. We verify that the constructed numerical method is robust, in the sense that the computed errors for the velocity components and their derivatives in the discrete maximum norm are Reynolds uniform. We construct and apply a special numerical method related to the Falkner–Skan technique to compute a reference solution for the error analysis of the velocity components and their derivatives. By means of extensive numerical experiments we show that the constructed direct numerical method is Reynolds uniform. Copyright © 2003 John Wiley & Sons, Ltd.
A Reynolds‐uniform numerical method for the Prandtl solution and its derivatives for stagnation line flow
Authors: Miller John J. H. , Musgrave Alison P. , Shishkin Grigorii I.
Published: October 2003

Farrell et al. (Robust Computational Techniques for Boundary Layers. Chapman & Hall/CRC: Boca Raton, 2000) develop a Reynolds‐uniform numerical method for the solution of the Prandtl equations in the case of flow past a flat plate. In this paper, we examine the applicability of this Prandtl method to the stagnation line flow problem in a domain that includes the stagnation line. Stagnation line flow has been chosen because of its self‐similar nature; reference solutions that approximate the exact solution of the problem to high levels of accuracy can be numerically obtained, allowing the error in the numerical approximations generated by the Prandtl method to be calculated. We present detailed results which verify that the method is Reynolds uniform. Global Reynolds‐uniform error bounds are constructed for the numerical approximations to the velocity components and their scaled first derivatives, and the practical uses of these bounds are discussed. We show that the number of iterations required for convergence of this iterative method is Reynolds uniform. In addition, we test an experimental technique for computing global Reynolds‐uniform error bounds, which can be used when solving flow problems for which no exact or reference solution is available. Experimental error bounds are constructed using this technique and are shown to be realistic upper bounds for the error values obtained with the use of the reference solutions. Copyright © 2003 John Wiley & Sons, Ltd.
RNA amplification and transcriptional profiling for analysis of stem cell populations
Authors: Gallardo Teresa D. , Hammer Robert E. , Garry Daniel J.
Published: October 2003

As 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

Summary: 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

Summary: 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

The 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

Tra2 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

Pbx1 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

Nkx2.5 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

This 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

A 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

Augmentation 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

Produced 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

Ultra‐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

A 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

Heat 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

Cinnamate 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
Altered expression of transcripts for α‐tubulin and an unidentified gene in the spinal cord of phenyl saligenin phosphate treated hens (Gallus gallus)
Authors: Fox Jonathan H. , Jortner Bernard S. , Barber David , Ehrich Marion F.
Published: October 2003

Phenyl saligenin phosphate (PSP) induces a central‐peripheral distal axonopathy in domestic fowl that develops 7–21 days after a single exposure. Neurotoxic esterase (NTE) is the initial molecular target for this neurotoxicity. PSP has to covalently bind to NTE and chemically “age” for induction of axonopathy. It was hypothesized that exposure to PSP results in early changes in spinal cord gene expression that do not occur with phenylmethylsulfonyl fluoride, a non‐neuropathic compound that also inhibits NTE, or DMSO controls. Targeted display was used to screen ∼15,000 gel bands. Three candidate genes were identified, but only the transcript designated P1 showed decreased expression following PSP exposure (2 mg/kg i.m.) in subsequent Northern blot and in situ hybridization experiments in samples taken <48 h after exposure. Additional experiments revealed that a ∼2.5 kb α‐tubulin transcript had decreased expression at 12–48 h after PSP exposure, with maximum change at 48 h (33%, p = 0.0479). A ∼4.5 kb α‐tubulin transcript had increased expression at 12 h (38%, p = 0.0125) and decreased expression at 48 h (28%, p = 0.0576). In situ hybridization on spinal cord revealed neuronal expression of P1 and α‐tubulin transcripts. Decreased expression of transcripts for P1 and α‐tubulin was present at 12 and 48 h, respectively. This decrease occurred in all neurons, not just those whose axons degenerate. Results suggest that (1) in PSP‐induced OPIDN (organophosphorus‐induced delayed neurotoxicity) some gene transcript expression changes are associated with initiation of axonopathy, and (2) PSP modulates spinal cord gene expression in neuronal types that do not undergo axonal degeneration. © 2003 Wiley Periodicals, Inc. J Biochem Mol Toxicol 17:263–271, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/jbt.10088
Effects of endocrine disrupting chemicals on distinct expression patterns of estrogen receptor, cytochrome P450 aromatase and p53 genes in oryzias latipes liver
Authors: Min Jiho , Lee Sung‐Kyu , Gu Man Bock
Published: October 2003

Expression pattern analysis of three genes, i.e., the estrogen receptor (ER), cytochrome P450 aromatase (CYP19), and p53 genes, in Japanese Medaka liver was studied in the presence of 17β‐estradiol, nonylphenol, and bisphenol A. Using the distinct expression patterns of these three genes, the different transcriptional mechanisms by endocrine disrupting chemicals (EDCs), and the stability of the transcripts of each gene, were examined. In tests done with both male and female Medaka over 10 days, it was found that each gene had a specific expression pattern. The expression of the ER gene increased rapidly for the first 2 days and then leveled out and maintained a stable expression level, while the CYP19 gene expression showed a fairly consistent increase in the expression levels after exposure. In contrast to both these genes, the p53 gene expression levels reached a maximum value within 2 days and then gradually decreased for the remainder of the experiment. These findings suggest that different expression mechanisms may exist for these genes in Japanese Medaka in response to the presence of EDCs. © 2003 Wiley Periodicals, Inc. J Biochem Mol Toxicol 17:272–277, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/jbt.10089
Perinatal exposure to low doses of 2,3,7,8‐tetrachlorodibenzo‐p‐dioxin alters sex‐dependent expression of hepatic CYP2C11
Authors: Ishizuka Mayumi , Yonemoto Junzo , Zaha Hiroko , Tohyama Chiharu , Sone Hideko
Published: October 2003

The cytochrome P450 (CYP) isoform CYP2C11 is specifically expressed in the liver of adult male rats, and 5α‐reductase is specifically expressed in the liver of the adult female rats. The sexually dimorphic expressions of these hepatic enzymes are regulated by the sex‐dependent profiles of the circulating growth hormone (GH). However, it is not well known whether hormonal imprinting or activation factors in the neonatal brain influence the sexually dimorphic expression patterns of hepatic enzymes. We therefore examined the effect of perinatal exposure to 2,3,7,8‐tetrachlorodibenzo‐p‐dioxin (TCDD) on sex‐dependent expressions of hepatic enzymes. Pregnant rats were treated with TCDD at a dose of 0, 200, or 800 ng/kg on gestation day 15, exposing the pups to the chemical. Although the expression of CYP2C11 protein in the livers of male pups on postnatal day (PND) 49 was significantly higher than that of the controls, but the 5α‐reductase activities in the livers of female pups were not altered by exposure to TCDD. Focusing on perinatal periods, testosterone and estrogen levels significantly increased in the brain of male pups on PND 2. The results suggest that the alteration of testosterone and estrogen levels affect hormonal imprinting in the neonatal brain of male pups, and thus induces a change in the level of male‐specific hepatic CYP2C11. We conclude that perinatal exposure to TCDD at low doses may change the sexual differentiation of the neonatal brain in male rats. © 2003 Wiley Periodicals, Inc. J Biochem Mol Toxicol 17:278–285, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/jbt.10090
Three‐dimensional transvaginal sonography of interstitial pregnancy
Authors: Izquierdo Luis A. , Nicholas M. Catherine
Published: October 2003

We describe the case of a 33‐year‐old pregnant woman, gravida 1 para 0, who was referred to us with a presumptive diagnosis of an interstitial pregnancy. The patient had had amenorrhea for 7 weeks and had previously undergone myomectomy. Two‐dimensional sonographic examination revealed a gestational sac located outside the uterine cavity but could not define its exact anatomic position. Using transvaginal 3‐dimensional sonography, we were able to correctly depict the sac, which was located where the fallopian tube crossed the uterine horn. We performed a cornual resection, during which the diagnosis of interstitial pregnancy was confirmed. The use of 3‐dimensional sonography in this patient's case thus led to appropriate early treatment and avoidance of possible subsequent morbidity. © 2003 Wiley Periodicals, Inc. J Clin Ultrasound 31:484–487, 2003
Doppler sonographic characteristics of umbilical and uterine arteries during oral glucose tolerance testing in healthy pregnant women
Authors: Yogev Yariv , Ben‐Haroush Avi , Chen Rony , Hod Moshe , Merril Ziela , Meizner Israel
Published: October 2003

Purpose

Studies have shown that maternal hyperglycemia may be associated with increased placental resistance to blood flow and possibly adverse perinatal outcomes. The aim of this study was to determine whether Doppler velocimetric dynamics change in the uterine and umbilical arteries in healthy pregnant women (without gestational diabetes) during acute hyperglycemia induced by oral glucose tolerance testing.

Methods

Flow in the umbilical and right and left uterine arteries was assessed by spectral Doppler sonographic examination of healthy pregnant women at 24–28 weeks' menstrual age. Four Doppler studies were conducted for each woman: 1 before oral administration of 100 g of glucose and 3 more at 1, 2, and 3 hours after glucose administration. The systolic‐to‐diastolic ratio was calculated for the umbilical artery, and the resistance index was calculated separately for the left and right uterine arteries.

Results

All results of oral glucose tolerance testing were normal, and Doppler signals were obtained in all 30 patients enrolled. No abnormal systolic‐to‐diastolic ratios or resistance indices were detected in any of the examinations. No significant differences in waveforms or resistance indices between the right and left uterine arteries were found during the various testing intervals.

Conclusions

Acute hyperglycemia induced in healthy pregnant women does not affect blood flow velocimetric characteristics in the umbilical or uterine arteries at any stage of oral glucose tolerance testing. © 2003 Wiley Periodicals, Inc. J Clin Ultrasound 31:461–464, 2003
Sonographic appearance of a congenital parotid gland hemangiolymphangioma simulating malignancy in an infant
Authors: Zacharia T. Thomas , Ittoop Asha , Perumpillichira James Joseph , Chavhan Govind
Published: October 2003

Congenital hemangiolymphangioma, also called mixed angioma, is a benign tumor that very rarely occurs in the parotid gland. We present a rare case of hemangiolymphangioma of the parotid gland in a 4‐month‐old boy whose clinical and radiologic presentation simulated malignancy. Gray‐scale and color Doppler sonography revealed an enlarged left parotid gland and inhomogeneous hypoechoic and hyperechoic areas scattered throughout the gland. Mild internal vascularity was noted on color Doppler sonographic examination. CT revealed a predominantly fatty mass involving the superficial lobe of the parotid gland. The results of fine‐needle aspiration cytology were inconclusive, and total parotidectomy was performed. Histopathologic examination of surgical specimens confirmed a diagnosis of hemangio lymphangioma. The patient recovered well and was free of recurrence at the 6‐month follow‐up visit. To our knowledge, this case report is the first to describe the findings of congenital hemangiolymphangioma of the parotid gland on sonography and CT. This rare diagnosis should be considered in neonates and infants presenting with a rapidly growing parotid gland tumor suggesting malignancy. Histopathologic examination is necessary to confirm the diagnosis. © 2003 Wiley Periodicals, Inc. J Clin Ultrasound 31:493–496, 2003
Normal growth and development of fetal external genitalia demonstrated by sonography
Authors: Pinette Michael G. , Wax Joseph R. , Blackstone Jacquelyn , Cartin Angelina
Published: October 2003

Purpose

Our aim in this retrospective sonographic study was to describe the normal growth and development of fetal external genitalia.

Methods

We reviewed the sonograms of anatomically normally fetuses, obtained over a 5‐year period, and measured transverse scrotal diameter or penile length in male fetuses and bilabial diameter in female fetuses. Transverse scrotal diameter was measured from the midpoint of the lateral scrotal wall to the midpoint of the opposite lateral wall; penile length, from the base of the shaft to the tip; and bilabial diameter, from the midpoint of the lateral labial margin to the midpoint of the opposite lateral labial margin.

Results

We examined sonograms from 1,182 fetuses and measured transverse scrotal diameter in 304 and penile length in 494 male fetuses and bilabial diameter in 384 female fetuses. The fetuses ranged from 14 to 41 weeks' menstrual age. Transverse scrotal diameter, penile length, and bilabial measurements were highly correlated with menstrual age (r = 0.941, r = 0.860, and r = 0.898, respectively). We found that growth of fetal external genitalia is similar to that for other parameters of fetal growth, such as biparietal diameter and femur length.

Conclusions

The results of this study may be helpful in understanding the natural course of the growth and development of fetal external genitalia. In addition, the data we gathered may be useful in combination with other biometric data for estimating fetal age and may help in detecting abnormalities in the fetal external genitalia. © 2003 Wiley Periodicals, Inc. J Clin Ultrasound 31:465–472, 2003
Idiopathic infantile arterial calcification: Sonographic findings
Authors: Whitehall John , Smith Mark , Altamirano Louis
Published: October 2003

Idiopathic infantile arterial calcification (IIAC) is a rare disease that is characterized by calcification in the media and fibroproliferative changes in the intima of larger arteries, sometimes resulting in reduced vascular elasticity and blood flow. Although the molecular‐genetic basis of the disease is unknown, IIAC is presumed to be acquired by an autosomal recessive mode of inheritance and is associated with a reduction in the levels of enzymes responsible for inorganic phosphate balance, resulting in abnormal deposition of calcium into the vessels. We report the case of a female neonate in whom widespread IIAC was initially diagnosed on postnatal sonographic examination. At birth, the infant experienced cardiac failure and hypertension, and arterial pulsation was absent. Routine prenatal sonographic examinations had not revealed any abnormalities, but postnatal gray‐scale and color Doppler echocardiographic and sonographic examinations revealed findings consistent with severe IIAC. The cardiac function improved with treatment, but the neonate died of progressive hepatic failure due to reduced flow in calcified and narrowed hepatic arteries. The common carotid arteries were also grossly affected, resulting in cerebral atrophy at the time of birth. Postnatal gray‐scale and color Doppler echocardiographic and sonographic examinations allowed noninvasive diagnosis, assessment of severity, and monitoring of progression. © 2003 Wiley Periodicals, Inc. J Clin Ultrasound 31:497–501, 2003
Testicular hamartomas in Cowden disease
Authors: Lindsay Christopher , Boardman Lisa , Farrell Michael
Published: October 2003

We report a case of testicular hamartomas in association with Cowden disease. Clinical examination of the patient, a 39‐year‐old man, revealed a palpable mass in the right side of the scrotum. Sonographic examination showed that the mass was either a spermatocele or an epididymal cyst and that multiple hyperechoic lesions were present in both testes. On subsequent MRI, the appearance of these lesions was consistent with that of fat‐containing hamartomas. Testicular biopsy was not performed, but follow‐up serial sonographic examination was recommended. To our knowledge, this report is the first to describe testicular hamartomas as a probable manifestation of Cowden disease. © 2003 Wiley Periodicals, Inc. J Clin Ultrasound 31:481–483, 2003