bluuebunny/crossref_metadata_2025 huggingface dataset:
Regional variations in the outer retina of atherinomorpha (Beloniformes, Atheriniformes, Cyprinodontiformes: Teleostei): Photoreceptors, cone patterns, and cone densities
Authors: Reckel Frank , Melzer Roland R.
Published: June 2003

The outer retinae of adults of 13 atherinomorph species, representing nine different families, were examined by both light and electron microscopy. The retinae were investigated with respect to photoreceptor types, cone densities, and cone patterns. All data were composed to eye maps. This procedure allows an interspecific comparison of the regional differences within the outer retina among these shallow‐water fish. Furthermore, for a more detailed pattern analysis nitro‐blue tetrazolium chloride‐ (NBT)‐stainings in the retina of Melanotaenia maccullochi are presented. Apart from rods, eight morphologically different cone types could be identified: short, intermediate, and long single cones, double cones (equal and unequal), triple cones (triangular and linear), and in Ameca splendens one quadruple cone. Dimensions and occurrence of photoreceptors vary among the respective species and within the retinal regions. In the light‐adapted state, the cones are arranged in highly ordered mosaics. Five different cone tessellation types were found: row patterns, twisted row patterns, square patterns, pentagonal patterns, and, exclusively in Belone belone, a hexagonal pattern. In Melanotaenia maccullochi the different spectral photoreceptor classes correspond well with the distribution of morphological photoreceptor classes within the mosaic. Double cone density maxima together with a highly ordered cone arrangement usually occur in the nasal and/or ventral to ventrotemporal retina. In most of the species that were examined these high‐density regions are presumed to process visual stimuli from the assumed main directions of vision, which mainly depend on feeding behavior and predator pressure. Our findings are discussed with respect to the variable behavioral and visual ecology and phylogeny of the respective species. J. Morphol. 257:270–288, 2003. © 2003 Wiley‐Liss, Inc.
Placoderm fishes, pharyngeal denticles, and the vertebrate dentition
Authors: Johanson Zerina , Smith Moya M.
Published: June 2003

The correlation of the origin of teeth with jaws in vertebrate history has recently been challenged with an alternative to the canonical view of teeth deriving from separate skin denticles. This alternative proposes that organized denticle whorls on the pharyngeal (gill) arches in the fossil jawless fish Loganellia are precursors to tooth families developing from a dental lamina along the jaw, such as those occurring in sharks, acanthodians, and bony fishes. This not only indicates that homologs of tooth families were present, but also illustrates that they possessed the relevant developmental controls, prior to the evolution of jaws. However, in the Placodermi, a phylogenetically basal group of jawed fishes, the state of pharyngeal denticles is poorly known, tooth whorls are absent, and the presence of teeth homologous to those in extant jawed fishes (Chondrichthyes + Osteichthyes) is controversial. Thus, placoderms would seem to provide little evidence for the early evolution of dentitions, or of denticle whorls, or tooth families, at the base of the clade of jawed fishes. However, organized denticles do occur at the rear of the placoderm gill chamber, but are associated with the postbranchial lamina of the anterior trunkshield, assumed to be part of the dermal cover. Significantly, these denticles have a different organization and morphology relative to the external dermal trunkshield tubercles. We propose that they represent a denticulate part of the visceral skeleton, under the influence of pharyngeal patterning controls comparable to those for pharyngeal denticles in other jawed vertebrates and Loganellia. J. Morphol. 257:289–307, 2003. © 2003 Wiley‐Liss, Inc.
Neuroanatomy of the harbor porpoise (Phocoena phocoena) from magnetic resonance images
Authors: Marino Lori , Sudheimer Keith , Sarko Diana , Sirpenski Gayle , Johnson John I.
Published: June 2003

Cetacean (dolphin, whale, and porpoise) brains are among the least‐studied mammalian brains because of the formidability of collecting and histologically preparing such relatively rare and large specimens. Among cetaceans, there exist relatively few studies of the brain of the harbor porpoise (Phocoena phocoena). Magnetic resonance imaging (MRI) offers a means of observing the internal structure of the brain when traditional histological procedures are not practical. Therefore, MRI has become a critical tool in the study of the brain of cetaceans and other large species. This article represents the first MRI‐based anatomically labeled three‐dimensional description of the harbor porpoise brain. Coronal plane sections of the brain of a young harbor porpoise were originally acquired and used to produce virtual digital scans in the other two orthogonal spatial planes. A sequential set of images in all three planes has been anatomically labeled and displays the proportions and positions of major neuroanatomical features. These images allow for the visualizing of the distinctive features of the harbor porpoise brain from various orientations by preserving the gross morphological structure of the specimen. J. Morphol. 257:308–347, 2003. © 2003 Wiley‐Liss, Inc.
Case of unilateral wing formation in the female of the glowworm Lampyris noctiluca
Authors: Maas Ulrike , Dorn August
Published: June 2003

On July 27, 1999, the first author found a unilaterally winged adult glowworm in a park in the city of Mainz. Except for the wings on the left side, the specimen exhibited female characteristics that extended to external sexual appendages, the lantern and the gonads. The internal organization showed some remarkable differences between right (wingless) and left (winged) side. The right ovary contained three times more mature eggs than the left side and the volume of the corpus allatum of this side was about one‐third larger than that of the left side. This suggests that aptery and egg maturation are affected by corpus allatum activity, i.e., juvenile hormone production. The findings do not support the hypothesis of Naisse ([1966] Arch Biol Liège 77:139–201) that wing formation, as a secondary male characteristic, is controlled by an androgenic hormone from the testes in the glowworm. Thus, the observations on this exceptional specimen have implications for the current hypotheses concerning the control of sexual wing dimorphism in Lampyris noctiluca. J. Morphol. 257:254–258, 2003. © 2003 Wiley‐Liss, Inc.
Ventral neurons in the anterior nerve cord of amphioxus larvae. II. Further data on the pacemaker circuit
Authors: Lacalli Thurston C.
Published: June 2003

Previous serial EM studies of the anterior nerve cord of amphioxus larvae implicate the third pair of large paired neurons (LPN3s) as key components of the pacemaker responsible for oscillatory premotor output in somites 1 and 2. Here the synaptic relationship between the LPN3s and a fourth such pair (LPN4s), located in somite 3, is examined from a second series of sections. Because of limited overlap between the two series, fiber identity can only be inferred in most instances. To act as pacemakers, the LPN3s must inhibit each other; the current data show similar patterns of synaptic contact, presumably also inhibitory, with the LPN4s. The oscillatory signal appears therefore to be relayed from one LPN pair to the next. Despite their evident importance in the anterior cord, the role these cells play more caudally in signal propagation is not clear. J. Morphol. 257:212–218, 2003. © 2003 Wiley‐Liss, Inc.
Direct‐temperature mass spectrometric detection of volatile terpenoids and natural terpenoid polymersin fresh and artificially aged resins
Authors: Scalarone Dominique , van der Horst Jerre , Boon Jaap J. , Chiantore Oscar
Published: June 2003

Electron impact (EI) ionization and ammonia chemical ionization (NH3/CI) direct‐temperature mass spectrometry (DTMS) was used to characterize five natural terpenoid resins: dammar, mastic, colophony, Manila copal and sandarac. Compositional differences were highlighted by the identification of low molecular mass compounds, ranging from di‐ to triterpenoids, and polymeric components, based on polycadinene and polycommunic acid. Photo‐ageing processes occurring under accelerated indoor and outdoor exposure conditions were also investigated. NH3/CI and tetramethylammonium hydroxide EI were applied to increase the sensitivity towards highly oxidized molecules. Oxidation and cross‐linking reactions were found to affect mostly triterpenoid resins and diterpenoid abietane and pimarane molecules. Oxidation proceeds through a radical mechanism, generally starting from conjugated double bonds. Oxygen atoms are incorporated in the terpenoid structures in the form of alcohols, ketones and carboxylic acids. Oxidized cadinene oligomers released by pyrolytic degradation of the polycadinene fraction of dammar were detected even in unaged samples. Evidence is given indicating the occurrence of cleavages in the cross‐linked polycommunic structure of aged sandarac and Manila copal. Bond scissions produce oligomeric fragments based on the communic acid structure and sufficiently volatile to be desorbed at low temperature in DTMS measurements. Copyright © 2003 John Wiley & Sons, Ltd.
Effect of buffer cations and of H3O+ on the charge states of native proteins. Significance to determinations of stability constants of protein complexes
Authors: Verkerk Udo H. , Peschke Michael , Kebarle Paul
Published: June 2003

The progressive reduction of charge in charge states of non‐denatured proteins (lysozyme, ubiquitin, and cytochrome c), observed with nanospray in the positive ion mode, when the buffer salt ammonium acetate is replaced by ethylammonium acetates (EtNH3Ac, Et2NH2Ac and Et3NHAc) is rationalized on the basis of the charge residue model (CRM). The charge states of the multiply protonated protein are shown to be controlled by the increasing gas‐phase basicities, GB(B), of the bases(B) NH3, EtNH2, Et2NH and Et3N. Charge states derived from evaluated apparent gas‐phase basicities GBapp of the basic side‐chains of the protein and the known GB(B) of the above bases are found to be in agreement with the experimentally observed charge states. This is a requirement of the CRM, because in this model the small positive ions (the buffer cations in the present case) at the surface of the electrospray droplets are the excess ions that provide the charge of the final small droplet that contains the protein molecule and on evaporation of the solvent transfer the charge to the protein. The observed charge states in the absence of buffer salts, i.e. pure water, are attributed to excess H3O+ ions produced by the electrolysis process that attends electrospray. A proposed extended mechanism provides predictions of factors that determine the sensitivity for detection of the multiply protonated proteins. Consideration of restraints imposed by the CRM lead to some simple predictions for conditions that should be present to obtain accurate determinations by electrospray and nanospray of stability constants for the protein–complex equilibrium in aqueous solution. Copyright © 2003 John Wiley & Sons, Ltd.
Esterification of borate with NAD+and NADH as studied by electrospray ionization mass spectrometry and11B NMR spectroscopy
Authors: Kim Danny H. , Marbois Beth N. , Faull Kym F. , Eckhert Curtis D.
Published: June 2003

This paper describes for the first time the direct measurement of boric acid (B(OH)3) and borate (B(OH)4−) adduction to NAD+and NADH by electrospray ionization mass spectrometry (ESI‐MS) and11B NMR spectroscopy. The analysis demonstrates that borate binds to bothcis‐2,3‐ribose diols on NAD+forming borate monoesters (1 : 1 addition), borate diesters (1 : 2 addition) and diborate esters (2 : 1 addition), whereas, only borate monoesters were formed with NADH. MS in the negative ion mode showed borate was bound to acis‐2,3‐ribose diol and not to the hydroxyl groups on the phosphate backbone of NAD+, and MS/MS showed that the 1 : 1 addition monoester contained borate bound to the adenosine ribose. Boron shifts of borate monoesters and diesters with NAD+were observed at 7.80 and 12.56 ppm at pH 7.0 to 9.0. The esterifications of borate with NAD+and NADH were pH dependent with maximum formation occurring under alkaline conditions with significant formation occurring at pH 7.0. Using ESI‐MS, the limit of detection was 50 µMfor NAD+and boric acid (1 : 1) to detect NAD+–borate monoester at pH 7.0. These results suggest esterification of borate with nicotinamide nucleotides could be of biological significance. Copyright © 2003 John Wiley & Sons, Ltd.
Assignment of acetyl groups to O‐2 and/or O‐3 of pectic oligogalacturonides using negative electrospray ionization ion trap mass spectrometry
Authors: Quéméner Bernard , Cabrera Pino Juan Carlos , Ralet Marie‐Christine , Bonnin Estelle , Thibault Jean‐François
Published: June 2003

Partially acetylated and methylated oligogalacturonides produced by enzymatic hydrolysis of sugar beet pectin were analysed by negative electrospray ionization ion trap mass spectrometry (ESI‐ITMS). The 18O labelling of the oligomer reducing end allowed the precise assignment of the fragments resulting from glycosidic bond and cross‐ring cleavages. The collisional‐induced dissociation of the Ci and Zj fragment ions through sequential MSn experiments always displayed 0, 2A‐type cross‐ring cleavage ions which were related to C2H4O2 losses. These 0, 2A ions appeared to be highly diagnostic ions allowing the precise location of the acetyl groups to the O‐2 and/or O‐3 of the acetylated galacturonic acid residues. Copyright © 2003 John Wiley & Sons, Ltd.
Development of a liquid chromatographic/tandem mass spectrometric assay for a new endothelin receptor antagonist, and its application to dog plasma samples generated after simultaneous i.v. and p.o. administration of the unlabeled and deuterium‐labeled forms of this antagonist
Authors: Lausecker B. , Fischer G.
Published: June 2003

An assay was developed and applied to determine the bioavailability of a new endothelin receptor antagonist after simultaneous p.o. and i.v. administration of the drug and its stable isotope‐labeled analogue. The drug, its main metabolite and the stable isotope‐labeled analogues of the drug and the main metabolite were quantified in dog plasma samples using a structural analogue as internal standard. In addition to the calculation of the bioavailability, the formation of the metabolite after p.o. and i.v. administration could be followed independently. The assay covered the concentration range 0.25–1000 ng ml−1 using sample aliquots of only 50 µl. Plasma samples were processed after protein precipitation with on‐line solid‐phase extraction, narrow‐bore high‐performance liquid chromatography and subsequent tandem mass spectrometric detection. Detection was accomplished with ionspray in the positive ion selected reaction monitoring mode. The inter‐assay precision and accuracy of the assay were in the range 4.7–14.2% and 90.3–113.3%, respectively, and the intra‐assay precision and accuracy were in the range 1.4–11.5% and 88.4–112.5%, respectively. The fragmentation of the drug was investigated and showed an unexpected shift of a methyl group. Data from MSn, medium‐resolution exact mass tandem mass spectrometry and H–D exchange experiments were employed to clarify the mechanism. Copyright © 2003 John Wiley & Sons, Ltd.
Manipulating internal energy of protonated biomolecules in electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry
Authors: Guo Xinghua , Duursma Marc C. , Kistemaker Piet G. , Nibbering Nico M. M. , Vekey Karoly , Drahos Laszlo , Heeren Ron M. A.
Published: June 2003

The internal energy of protonated leucine enkephalin has been manipulated in electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry with two newly designed pump–probe experiments. Blackbody infrared radiation was applied to pump an ion population into a well‐defined internal energy distribution below the dissociation threshold. Following this pumping stage, the internal energy distribution was probed using on‐resonance collisional activation to dissociate the ions. These pump–probe experiments were carried out in two different ways: (a) using on‐resonance collisional activation with variable kinetic energies to dissociate the ions at a constant initial ion temperature (determining the precursor ion survival percentage as a function of kinetic energy) and (b) using on‐resonance collisional activation with a constant kinetic energy to dissociate the ions at variable initial ion temperatures (to investigate the ion survival yield–initial ion temperature dependence). Using this approach, a detailed study of the effects of the initial ion temperature, the probing kinetic energy and the internal energy loss rate on the effective conversion efficiency of (laboratory‐frame) kinetic energy to internal energy was conducted. This conversion efficiency was found to be dependent on the initial ion temperature. Depending on the experimental conditions the conversion efficiency (for collisions with argon) was estimated to be about 4.0 ± 1.7%, which agrees with that obtained from a theoretical modeling. Finally, the reconstructed curves of the ion survival yield versus the mode of the (final) total internal energy distribution of the activated ion population (after pump and probe events) at different pump–probe conditions reveal the internal energy content of the activated ions. Copyright © 2003 John Wiley & Sons, Ltd.
Collision‐induced dissociation of the negative ions of simvastatin hydroxy acid and related species
Authors: Qin Xue‐Zhi
Published: June 2003

Simvastatin hydroxy acid (1) is a well‐known, potent HMG‐CoA reductase inhibitor for the treatment of hypercholesterolemia. Its lactone, simvastatin (commercial name Zocor) (a prodrug of 1), has been widely prescribed in the USA and throughout the world. In this work, collision‐induced dissociation (CID) of the negative ion of 1 (m/z 435), a carboxylic anion, was analyzed in detail. The major fragmentation pathway of this ion is a novel de‐esterification to form the negative product ions at m/z 319 and 115. The ion at m/z 319 undergoes further collision‐induced rearrangements to form the negative ions at m/z 215, 159 and 85. Possible mechanisms of the de‐esterification are discussed in terms of both charge‐initiated and charge‐remote fragmentations. The de‐esterification of the negative ion of 1 and the rearrangements of the ion at m/z 319 are rationalized by charge transfer and negative‐charge initiated fragmentation. This study deepens our understanding of collision‐induced fragmentations of carboxylic anions with multi‐functional groups. A comparison of the CID data for the negative ions of 1 and 5 (a major oxidation degradate of 1) indicates that the analysis of the CID data for 1 can serve as a basis for identification of oxidation degradation products or metabolites of 1. The analysis of the CID data for the negative ion of 1 also reveals the fundamental characteristics of the CID data for the negative ions of other statin hydroxy acids such as lovastatin (3) and pravastatin (4). Copyright © 2003 John Wiley & Sons, Ltd.
Screening for and validated quantification of amphetamines and of amphetamine‐ and piperazine‐derived designer drugs in human blood plasma by gas chromatography/mass spectrometry
Authors: Peters Frank T. , Schaefer Simone , Staack Roland F. , Kraemer Thomas , Maurer Hans H.
Published: June 2003

The classical stimulants amphetamine, methamphetamine, ethylamphetamine and the amphetamine‐derived designer drugs MDA, MDMA (‘ecstasy’), MDEA, BDB and MBDB have been widely abused for a relatively long time. In recent years, a number of newer designer drugs have entered the illicit drug market. 4‐Methylthioamphetamine (MTA), p‐methoxyamphetamine (PMA) and p‐methoxymethamphetamine (PMMA) are also derived from amphetamine. Other designer drugs are derived from piperazine, such as benzylpiperazine (BZP), methylenedioxybenzylpiperazine (MDBP), trifluoromethylphenylpiperazine (TFMPP), m‐chlorophenylpiperazine (mCPP) and p‐methoxyphenylpiperazine (MeOPP). A number of severe or even fatal intoxications involving these newer substances, especially PMA, have been reported. This paper describes a method for screening for and simultaneous quantification of the above‐mentioned compounds and the metabolites p‐hydroxyamphetamine and p‐hydroxymethamphetamine (pholedrine) in human blood plasma. The analytes were analyzed by gas chromatography/mass spectrometry in the selected‐ion monitoring mode after mixed‐mode solid‐phase extraction (HCX) and derivatization with heptafluorobutyric anhydride. The method was fully validated according to international guidelines. It was linear from 5 to 1000 µg l−1 for all analytes. Data for accuracy and precision were within required limits with the exception of those for MDBP. The limit of quantification was 5 µg l−1 for all analytes. The applicability of the assay was proven by analysis of authentic plasma samples and of a certified reference sample. This procedure should also be suitable for confirmation of immunoassay results positive for amphetamines and/or designer drugs of the ecstasy type. Copyright © 2003 John Wiley & Sons, Ltd.
Approximation by Gegenbauer polynomials in the study of a rectangular ridged waveguide. Application to the analysis of a waveguide septum polarizer
Authors: Boukli‐Hacene Noureddine , Sombrin Jacques , Papiernik Albert
Published: June 2003

Several methods have been used for the study of a ridged waveguide. In this paper, we propose the use of Gegenbauer polynomials in the decomposition of the electromagnetic field near the edges of the septum, for the computation of cut‐off frequencies and electromagnetic TE and TM fields in the ridged waveguide sections. This study is applied to analyse a waveguide septum polarizer that was experimentally studied by M.H. CHEN and G.N. TSANDOULAS en 1972. The useful performances of the polarizer (ellipticity ratio, circular polarization ratio) are computed from the geometrical dimensions of the waveguide and the septum. The method is based on the computation of discontinuities between waveguides with different ridge height by mode matching and the cascading of scattering parameter matrices representing the discontinuities and the waveguide lengths, resulting in the global S matrix of the polarizer. The computed results are compared with those obtained by other methods and shown to be in good agreement which verify the theory. Plots of field distributions prove also the accuracy of the results. Copyright © 2003 John Wiley & Sons, Ltd.
Monte Carlo modelling of abrupt InP/InGaAs HBTs
Authors: Garcias‐Salvá Pau , López‐González Juan M. , Prat Lluis
Published: June 2003

In this paper a Monte Carlo simulator which is focused on the modelling of abrupt heterojunction bipolar transistors (HBTs) is described. In addition, simulation results of an abrupt InP/InGaAs HBT are analysed in order to describe the behaviour of this kind of device, and are compared with experimental data.

A distinctive feature of InP/InGaAs HBTs is their spike‐like discontinuity in the Ec level at the emitter–base heterojunction interface. The transport of electrons through this potential barrier can be described by the Schrödinger's equation. Therefore, in our simulator we have consistently included the numerical solution of this equation in the iterative Monte Carlo procedure.

The simulation results of the transistor include the density of electrons along the device and their velocity, kinetic energy and occupation of the upper conduction sub‐bands. It is shown that the electrons in the base region and in the base–collector depletion region are far from thermal equilibrium, and therefore the drift–diffusion transport model is no longer applicable.

Finally, the experimental and simulated Gummel plots JC(VBE) and JB(VBE) are compared in the bias range of common operation of these transistors, showing a good data agreement. Copyright © 2003 John Wiley & Sons, Ltd.
Numerically distributed circuit parameters model on microstrip transmission line circuits and its application on CAD
Authors: Zhong Xiaolong , Mei Kenneth K. , Liu Yaowu
Published: June 2003

A new numerical model of microstrip transmission line circuits in terms of distributed circuit parameters is here illustrated. Based on full‐wave electromagnetic results, the extraction methods of these distributed circuit parameters on different types of microstrip transmission line circuits are introduced. As a preparatory experiment, an improved CAD method using this model is tested on microstrip low‐pass filter. Copyright © 2003 John Wiley & Sons, Ltd.
A termination structure of 2.5kV IGBT with field plate and semi‐resistive (SIPOS) layer
Authors: Kim Hyoung‐Woo , Moon Jin‐Woo , Chung Sang‐Koo
Published: June 2003

A junction termination with a field plate combined with a semi‐resistive layer deposited on front oxide layer is proposed for the first time as a termination structure of a 2.5 kV IGBT which allows high forward blocking voltage. The voltage handling capability of the proposed structure is compared with that for the conventional multiful floating ring structure and verified by the two‐dimensional device simulator, MEDICI. The numerically calculated breakdown voltages are 2205 and 2471 V for the multiple floating ring and proposed structures, respectively, yielding 11.3% improvement in the breakdown voltage. The breakdown voltage can be enhanced to 2500 V for the proposed structure when a floating ring is located at the edge of the field plate under the oxide. Copyright © 2003 John Wiley & Sons, Ltd.
An efficient algorithm for optimizing the electrical performance of HBTs
Authors: Ahn Hyungkeun , El‐Nokali M. , Han Deuk‐Young
Published: June 2003

A physical model for AlGaAs/GaAs heterojunction bipolar transistor with different emitter and base structures is proposed. The recombination currents in various depletion regions of the device are derived and are used to calculate the collector current in the range of 300–600 K. The theoretical predictions of the model are compared with the numerical and experimental data available in the literature. The model is used to derive an efficient algorithm that optimizes the device structure for a given unity current gain frequency and collector current. Copyright © 2003 John Wiley & Sons, Ltd.
Application of the short‐open calibration technique to vector finite element method for analysis of microwave circuits
Authors: Chen R. S. , Wang D. X. , Yung Edward K. N.
Published: June 2003

A novel numerical de‐embedding scheme called the short‐open calibration (SOC) technique, in conjunction with the vector finite element method (FEM), has been developed to characterize two‐port network of arbitrarily shaped, three‐dimensional discontinuities in microwave circuits. This SOC technique is effectively implemented into the FEM for boundary truncation of the unbounded circuit structures. In such a manner, fast convergence of iterative solver for large‐sparse linear matrix equations from FEM is achieved. The SOC technique is used to remove parasitic effects brought by the approximation of the impressed voltage source and also the problem of resulting consistency between the two‐ and three‐dimensional simulations. Scattering parameters of discontinuous sections are constructed from the definition of port voltages and currents. Numerical solutions are well compared with those published in the available literatures. It is demonstrated that the features of the SOC technique are advantageous when combined with FEM for electromagnetic problems. Copyright © 2002 John Wiley & Sons, Ltd.
An efficient preconditioning technique for numerical simulation of hydrodynamic model semiconductor devices
Authors: Yang Geng , Wang Shaodi , Wang Ruchuan
Published: June 2003

We investigate the application of preconditioned generalized minimal residual (GMRES) algorithm to the equations of hydrodynamic model of semiconductor devices. An introduction to such a model is presented. We use finite‐element method P1‐isoP2 element to discretize the equations. A preconditioning technique is proposed. The CPU times are presented for n+‐n‐n+ diodes and 0.25 μm gate length Si MESFETs by using the preconditioned GMRES algorithm and the GMRES algorithm. The numerical results show that the preconditioning technique accelerates effectively the velocity of convergence. Copyright © 2003 John Wiley & Sons, Ltd.
Effect of radiation and cell implantation on wound healing in a rat model
Authors: Dantzer Dale , Ferguson Peter , Hill Richard P. , Keating Armand , Kandel Rita A. , Wunder Jay S. , O'Sullivan Brian , Sandhu Jas , Waddell Jennifer , Bell Robert S.
Published: June 2003

Background and Objectives

Having shown that intra‐dermal injection of fibroblasts decreases the effect of radiation on healing of superficial wounds, we now test the effect of fibroblasts and syngeneic marrow stromal cells on irradiated deep and superficial wounds.

Methods

Wistar rats received bilateral buttock irradiation followed by partial excision of the gluteus muscle bilaterally. In Protocol 1, one irradiated wound was treated with 1.2 × 107 autologous cells injected intra‐dermally. In Protocol 2, the experimental side was treated with a fibrin and autologous cell implant (1.2 × 107 cells). Twenty‐one days later, wound mechanical characteristics were tested. In Protocol 3, the effect of pooled marrow stromal cells on healing of superficial irradiated wounds in Lewis rats was similarly tested.

Results

The fibrin–fibroblast implant (Protocol 2) had no effect on wound mechanics. Superficial injection of fibroblasts (Protocol 1) significantly improved wound breaking strength when compared to the control group (mean ± SEM, breaking strength: treated 504.6 ± 37.0 g vs. control 353.4 ± 35.2 g, P = 0.005). The dermal injection of marrow stromal cells also resulted in marked increases in breaking strength (mean ± SEM, breaking strength: treated 338.5 ± 39.9 g vs. control 187.1 ± 12.0 g, P < 0.01). In both Protocols 1 and 3, ultimate tensile strength and toughness were increased in the side receiving cell transplantation.

Conclusions

Cell implantation holds promise for decreasing the effect of radiation on healing of irradiated wounds. J. Surg. Oncol. 2003;83:185–190. © 2003 Wiley‐Liss, Inc.
Peritoneal mesothelioma treated by induction chemotherapy, cytoreductive surgery, and intraperitoneal hyperthermic perfusion
Authors: Deraco Marcello , Casali Paolo , Inglese M.G. , Baratti Dario , Pennacchioli Elisabetta , Bertulli Rossella , Kusamura Shigeki
Published: June 2003

Background and Objectives

Peritoneal mesothelioma (PM) is a rare disease, with a poor prognosis. We decided to prospectively evaluate the prognostic impact of aggressive surgery followed by intraperitoneal chemotherapy with local hyperthermia.

Patients and Methods

In this prospective study, 19 patients with PM were treated by cytoreductive surgery (CRS) and intraperitoneal hyperthermic perfusion (IPHP). Mean follow‐up was 27 months (range: 1–65). Fifteen (68%) patients had malignant disease, two had well‐differentiated papillary mesothelioma, and two had multicystic PM. Thirteen (65%) patients received preoperative chemotherapy. Fifteen cases (75%) underwent optimal cytoreduction (residual disease <2.5 mm). One patient underwent the procedure twice due to locoregional progression. IPHP was performed with closed abdomen technique, using a preheated polysaline perfusate (42.5°C) containing cisplatin + mitomycin C or cisplatin + doxorubicin administered through a heart–lung pump for 60 or 90 min.

Results

Three‐year overall and progression‐free survival was 69 and 66%, respectively. The operative morbidity (grade II/III), mortality, and overall toxicity (grade I–IV) rates were 25, 0, and 30%, respectively. Seventeen (94%) out of 18 patients had resolution of ascites.

Conclusions

This therapeutic strategy proved feasible and was well tolerated. Early results seem promising and consistent with a potentially major impact on survival in selected patients with PM. J. Surg. Oncol. 2003;83:147–153. © 2003 Wiley‐Liss, Inc.
Ewing's sarcoma of the pelvis: Combined surgery and radiotherapy treatment
Authors: Rödl Robert W. , Hoffmann Christiane , Gosheger Georg , Leidinger Benedikt , Jürgens Heribert , Winkelmann Winfried
Published: June 2003

Background and Objectives

Local therapy of pelvic Ewing's sarcoma remains a challenge because of the complex anatomy and large tumor volumes. Wide resections often end up contaminated with marginal margins in one part of the specimen. Pelvic tumor surgery causes considerable disability, because of the loss of hip function. This may cause a low quality of life for tumor survivors. The aim of the study was to evaluate the oncologic results of combined surgery and radiotherapy of pelvic Ewing's sarcoma. Functional and psychosocial outcome of the tumor survivors was assessed.

Methods

Thirty‐six pelvic Ewing's sarcoma patients were treated surgically for local tumor control between 1986 and 1996. Chemotherapy was administered according to current European Intergroup/Cooperative Ewing's Sarcoma Study (EI/CESS) protocols. Radiotherapy was also performed on all patients. All patients were intended to get wide tumor excision and a limb salvage procedure. Complications necessitating operative revision were analyzed and functional results were scored according to the criteria of the Musculoskeletal Tumor Society (MSTS). Quality of life and psychosocial functioning was assessed by the QLQ‐C 30 of the European Organization for Research and Treatment of Cancer (EORTC).

Results

The overall 5‐ and 10‐year survival rate was 45%. The prognosis of patients with primary metastases was 33%. There were two local recurrences after marginal resection. Every second patient needed at least one surgical revision. A secondary hindquarter amputation was avoided in all patients. MSTS functional evaluation instruments reached 59% (±21.0%). Global quality of life of the QLQ‐C 30 showed good results (70 ± 16%) compared to the general population (75 ± 24%).

Conclusions

The advantages of surgical local control of pelvic Ewing's sarcoma should be offered to the patient. Quality of life measurement after internal hemipelvectomy shows that the life of these patients is more than worth living and that they are able to compensate the functional impairment. J. Surg. Oncol. 2003;83:154–160. © 2003 Wiley‐Liss, Inc.
Levels of soluble intercellular adhesion molecule‐1 and total sialic acid in serum of patients with colorectal cancer
Authors: Basoglu Mahmut , Yildirgan Mehmet Ilhan , Taysi Seyithan , Yilmaz İsmayil , Kiziltunc Ahmet , Balik Ahmet A. , Celebi Fehmi , Atamanalp Sabri Selcuk
Published: June 2003

Background and Objectives

Serum soluble intercellular adhesion molecule‐1 (sICAM‐1) and total sialic acid (TSA) are related to the metastatic potential of cancer cells. The purpose of the present investigation was to determine sICAM‐1 and TSA levels in colorectal carcinoma and correlate their levels with the cancer stage.

Methods

The sera from 65 patients with colorectal cancer (18 at Dukes' B, 24 at Dukes' C, 23 at Dukes' D) were extracted before treatment. The concentrations of sICAM‐1 and TSA were measured by enzyme‐linked immunoassay and the thiobarbituric acid method, respectively, and compared with those from a healthy control group (n = 42).

Results

Mean serum sICAM‐1 and TSA levels were found to be higher in the total patient group than in the control group (P < 0.0001). The concentrations of sICAM‐1 and TSA were significantly higher in patients with Dukes' C and Dukes' D. The correlations between sICAM‐1 and TSA became more significant as the stage of the disease increased (r = 0.58, P < 0.05 in Dukes' B, r = 0.88, P < 0.01 in Dukes' C and r = 0.81, P < 0.01 in Dukes' D).

Conclusions

The results of this investigation indicate that sICAM‐1 and TSA are the best of the tested markers. These markers should prove useful for monitoring malignant disease stage and for evaluating the effectiveness of various therapeutic approaches for colorectal carcinomas. J. Surg. Oncol. 2003;83:180–184. © 2003 Wiley‐Liss, Inc.
Significance of thymidine phosphorylase in HCC with chronic liver disease for long‐term postoperative recurrence
Authors: Ezaki Takahiro , Ikegami Toru , Ishida Teruyoshi , Aimitsu Shiomi , Mori Masaki , Fujihara Megumu
Published: June 2003

Background and Objectives

Little is known about the significance of thymidine phosphorylase (TP) levels in HCC. The authors investigated the TP activity of HCC and adjacent normal liver tissue in 70 HCC patients, and the prognostic significance of the TP levels.

Methods

We obtained fresh samples (tumors with adjacent normal tissues) from 70 patients with HCC who have undergone curative hepatic resection. The levels of TP activity in unfixed, fresh, frozen HCC tissue, together with adjacent normal liver tissue specimens, were determined by the enzyme‐linked immunosorbent assay (ELISA) method.

Results

The mean TP activity in HCC was approximately 1.5‐fold higher than that in adjacent liver tissues (P = 0.0013). Disease‐free survival rates for patients with low and high TP levels in HCC were not significantly different. Although disease‐free survival rates for low and high TP levels in adjacent normal liver tissue were also not significantly different, disease‐free survival for patients with low and high TP levels in adjacent normal liver tissue, excluding cases of postoperative recurrence within 700 days of hepatectomy, showed a significant difference (P = 0.0494). The group with high TP activity in adjacent liver tissue showed more frequent postoperative recurrence in the long‐term than that with low TP activity.

Conclusions

Measurement of TP activity of adjacent normal liver tissue to HCC may allow us to predict metachronous long‐term postoperative recurrence. J. Surg. Oncol. 2003;83:173–179. © 2003 Wiley‐Liss, Inc.
Randomised clinical trial of adjuvant postoperative RT vs. sequential postoperative RT plus 5‐FU and levamisole in patients with stage II–III resectable rectal cancer: A final report
Authors: Cafiero Ferdinando , Gipponi Marco , Lionetto Rita ,   the P.A.R. Cooperative Study Group
Published: June 2003

Background and Objectives

A randomised clinical trial was performed in patients undergoing radical surgery for rectal cancer to compare the efficacy and toxicity of adjuvant postoperative radiation therapy (RT) to sequential RT and chemotherapy (CT) with 5‐fluorouracil (5‐FU) plus levamisole (LEV). The primary end point was overall survival (OS); secondary end points were disease‐free survival (DFS), the rate of loco‐regional recurrence, and treatment‐related toxicity; the final results of this trial are reported.

Methods

Patients in arm I underwent RT (50 Gy) in daily fractions of 2 Gy, 5 days/week for 5 weeks. Patients in arm II began with 5‐FU (450 mg/sqm/day intravenous (i.v.) bolus, days 1–5) plus LEV (150 mg/day orally, days 1–3); postoperative RT was delivered during week 2 at the same dosage and schedule as in arm I. The other five cycles of CT (5‐FU every 28 days and LEV every 15 days for the length of 5‐FU administration) continued after the end of RT if clinical and hemato‐biochemical parameters were in the normal range.

Results

From May 1992 to December 1998, 218 patients were enrolled into the randomised clinical trial (144 men, 74 women; age range: 28–75, median 64 years). The median follow‐up time was 58.1 months (range: 1–3,271 days). No significant difference was observed between the two arms of treatment as regards OS and DFS (P = 0.18 and P = 0.66, respectively). Cox regression analysis for OS confirmed what was observed by univariate analysis for all variables except age. Older age (>60 years) and pathologic lymph‐node involvement defined the subgroups with the worst prognosis. Cox regression analysis for DFS confirmed what was observed by univariate analysis for all variables: the only independent variable in predicting DFS was pathologic lymph‐node involvement.

Conclusions

Our findings suggest no difference in OS, loco‐regional and distant site progressions of postoperative RT alone compared to sequential postoperative RT and CT; notably, this latter regimen was associated with higher toxicity which seriously impaired the patient's compliance to CT. The low loco‐regional recurrence rate (9.2%) observed in our patients undergoing postoperative RT alone compared to similarly treated patients in previously performed clinical trials (20–25%) underline the role of radical surgery (mesorectal excision) coupled with a complete postoperative RT regimen. On the other hand, the similar efficacy of these two adjuvant modalities of treatment might be conditioned by both the low compliance (59%) to the CT regimen as well as the sequential, instead of concurrent, schedule of administration of RT and CT, which may have decreased further the expected efficacy of the combined regimen. J. Surg. Oncol. 2003;83:140–146 © 2003 Wiley‐Liss, Inc.
Pancreatic resection for metastatic tumors to the pancreas
Authors: Sperti Cosimo , Pasquali Claudio , Liessi Guido , Pinciroli Luca , Decet Giandomenico , Pedrazzoli Sergio
Published: June 2003

Background and Objectives

The incidence of metastases to the pancreas is very low. The benefit of resection of pancreatic metastasis is poorly defined. In this review we evaluated the outcome of patients undergoing pancreatic resection for metastatic tumors to the pancreas.

Methods

Eight patients underwent pancreatic resection for metastatic tumor from December 1980 to June 2001. The primary cancer was colon carcinoma (n = 4), renal cell cancer (n = 2), duodenal leiomyosarcoma (n = 1), and malignant fibrous histiocytoma (n = 1). The median interval between primary treatment and detection of pancreatic metastases was 36 months. In two cases pancreatic metastases were synchronous with the primary tumor.

Results

Four patients underwent pancreatoduodenectomy, two distal pancreatectomy, one total pancreatectomy, and one median pancreatectomy. Associated resection of extrapancreatic lesions was performed in four patients, including two left hepatectomy and two left colectomy. There was no postoperative mortality, but two patients had a pancreatic and a biliary fistula, respectively. Survival averaged 23 months (range 14–42 months): four patients died for metastatic disease from 14 to 42 months after operation, while four patients are alive and well 14 to 31 months after surgery.

Conclusions

Pancreatic resection for metastatic disease to the pancreas should be considered even in selected patients with limited extrapancreatic disease. Long‐term survival or good palliation may be achieved. J. Surg. Oncol. 2003;83:161–166. © 2003 Wiley‐Liss, Inc.
Prognostic factors affecting survival and disease‐free survival in lymph node‐negative breast carcinomas
Authors: Kuru Bekir , Camlibel Mithat , Ali Gulcelik Mehmet , Alagol Haluk
Published: June 2003

Background and Objectives

The objective of this study was to identify the patients who are at low or high‐risk by defining the prognostic factors in node‐negative breast carcinomas.

Methods

Medical records of 384 consecutive breast cancer patients with negative axillary lymph nodes who had been operated on between January 1994 and January 1997 at our hospital were retrospectively reviewed. Several clinical and pathological characteristics of patients were categorized. Univariate analyses of survival and disease‐free survival (DFS) were performed by the Kaplan–Meier method and the log‐rank test. Independent prognostic and predictive factors affecting survival and DFS were assessed by Cox proportional hazard method.

Results

5‐year survival and DFS were 91.4 and 85.7%, respectively. Size, grade, age, and lymphovascular invasion (LVI) were the prognostic factors that independently affected survival and DFS. Tamoxifen improved survival and DFS. While age younger than 35 was an adverse factor for both survival and DFS, age older than 49 was a detrimental factor for DFS.

Conclusions

Patients who have a tumor with size greater than 2 cm, with histologic grade 3, with LVI, and patients with age under 35 or older than 49 have poorer prognosis among node‐negative breast carcinomas, and are candidates for adjuvant therapy. J. Surg. Oncol. 2003;83:167–172. © 2003 Wiley‐Liss, Inc.
Keeping watch: How to monitor and maintain a team
Authors: Kanaga Kim , Browning Henry
Published: June 2003

Between the time a team is launched and the time the team gets results, leaders need to know whether the team
is on course. To do this they need to monitor the effectiveness of the team on an ongoing basis and make course
corrections that prevent small problems from becoming major disasters. Assessing a team's performance,
zeroing in on areas of weakness, and taking the necessary corrective measures help the team deliver peak
performance and the expected results.
Face to Face — Power to change: A conversation with Bernard M. Bass
Authors: Bass Bernard M.
Published: June 2003

Bernard M. Bass, the distinguished professor emeritus of organizational behavior at the State University of New York at Binghamton, is a leading authority on the subject of transformational leadership, a term introduced in 1978 by leadership studies pioneer James McGregor Burns. Bass has researched and written extensively on transformational leadership and has worked closely with business, military, and educational organizations to incorporate transformational leadership principles into real‐world settings.
Tough going: Learning from experience the hard way
Authors: Moxley Russ S. , Pulley Mary Lynn
Published: June 2003

No one would ever choose to experience a hardship, but leaders say that difficult times are often key events
in their development. Hardships can make people more aware of their values, their aspirations, and themselves.
Here's a look at six types of hardship events and the lessons executives can take from these events to make
themselves better leaders.
Reactive Blending of Polyamides with Different Carbonyl Containing Olefin Polymers
Authors: Sémeril David , Passaglia Elisa , Bianchini Claudio , Davies Maxwell , Miller Hamish , Ciardelli Francesco
Published: June 2003

In this paper the blending of polyamides nylon 6 and nylon 12, with a perfectly alternating ethylene/CO copolymer containing 50 mol‐% carbonyl groups (polyketone) is investigated in comparison to blends of the same polyamides with polyolefins containing varying degrees of carbonyl group incorporation. These include a poly[ethylene‐co‐(methyl acrylate)] copolymer containing 1.9 mol‐% methyl ester groups and poly[ethylene‐co‐(ethyl undecylenate)] copolymers with between 0.20 and 1.25 mol‐% ester incorporation. Blends were obtained of polyamides and the polyolefins in compositions between 20/80 and 80/20 in solution and in a Brabender mixer. SEM studies together with TGA, DSC and FTIR measurements show excellent compatibilization for both polyketone and poly[ethylene‐co‐(methyl acrylate)] copolymers with the nylons. The poly[ethylene‐co‐(ethyl undecylenate)] polymers displayed much less compatibilization although they still performed significantly better compared to pure polyethylene. The difference in compatibilization is discussed with respect to the importance of both the number of interactive groups present in the polyolefin and the steric requirements of hydrogen bond formation.

SEM micrograph of the fracture surface of the blend nylon 6/polyethylene 70:30.

magnified image

SEM micrograph of the fracture surface of the blend nylon 6/polyethylene 70:30.