bluuebunny/crossref_metadata_2025 huggingface dataset:
On‐going solutions to environmental issues in plastic packaging
Authors: Katsura Tadahiko , Sasaki Haruo
Published: August 2002

Recently, the consumption of polyvinyl chloride (PVC) and polyvinylidene chloride (PVDC) resins as packaging materials has been declining in the face of various environmental problems they pose. To replace PVC containers, the use of PET bottles and A‐PET containers is on the increase, but PVDC resins are still in wide use as gas‐barrier materials. For gas‐barrier purposes, however, ethylene vinyl alcohol co‐polymer (EVOH) films, polyvinyl alcohol (PVA)‐coated polypropylene films, and MX nylon or silica‐ or alumina‐coated PET films are becoming mainstream. The weight reduction of plastic bottles is considered to play an important role in tackling the waste disposal problem. Recently, a new type of stretch‐blow moulding system has been developed, which is effective in reducing the weight of PET bottles. This system is called COSMOS (complete stretch‐blow moulding system) or the two‐blow system. COSMOS PET bottles are now used to hold carbonated drinks containing fruit juice or lactic acid. Copyright © 2001 John Wiley & Sons, Ltd.
Modulation effects of zinc on the formation of vitamin D receptor and retinoid X receptor α‐DNA transcription complexes: analysis by microelectrospray mass spectrometry
Authors: Craig Theodore A. , Benson Linda M. , Naylor Stephen , Kumar Rajiv
Published: August 2002

The vitamin D receptor (VDR) binds zinc, and the activity of vitamin D dependent genes in cells is influenced by intracellular zinc concentrations. To determine whether zinc influences vitamin D action in cells by modulating the formation of VDR and retinoid x receptor α (RXRα) heterodimer‐DNA complexes, we used microelectrospray ionization mass spectrometry (µESI‐MS) to assess receptor‐DNA interactions in the presence of varying amounts of zinc. In the absence of DNA, VDR and RXRα proteins were primarily monomeric with small amounts of protein homodimers also observed. Zn2+ (up to 300 µM) did not change VDR or RXRα monomer/homodimer ratios. Mass spectra of VDR combined with RXRα were a sum of individual protein spectral data. Zn2+ had no effect on the interactions of receptors. With increasing amounts of Zn2+, additional Zn2+ ions were detected bound to VDR and RXRα. µESI‐MS analyses of RXRα in the presence of an osteopontin vitamin D DNA response element (OP‐VDRE) showed RXRα homodimer/OP‐VDRE complexes. DNA‐protein complex formation increased on addition of Zn2+ up to 200 µM; at 300 µM, Zn2+ dissociation of the RXRα homodimer/OP‐VDRE complexes occurred, coincident with the appearance of RXRα monomeric protein. When µESI‐MS analyses were carried out with VDR and OP‐VDRE, VDR homodimer/OP‐VDRE complexes were not detected. Addition of Zn2+ did not result in VDR/OP‐VDRE complex formation. Heterodimeric VDR/RXRα complexes with OP‐VDRE were detected by µESI‐MS. Addition of 300 µM Zn2+ resulted in dissociation of the heterodimeric VDR/RXRα/OP‐VDRE complex. Addition of Mg2+ in place of Zn2+ did not alter protein/OP‐VDRE complexes. Our results show that zinc modulates steroid hormone receptor‐DNA interactions. Copyright © 2001 John Wiley & Sons, Ltd.
Use of on‐line hydrogen/deuterium exchange to facilitate metabolite identification
Authors: Liu David Q. , Hop Cornelis E.C.A. , Beconi María G. , Mao Ann , Chiu Shuet‐Hing Lee
Published: August 2002

An Erratum for this article has been published in Rapid Communications in Mass Spectrometry 17(3) 2003, 264

Biotransformation studies performed on an investigational compound (I, represented by R1‐CH(NH2)‐CO‐N(R2)‐CH2‐S‐R3) led to the identification of five metabolites (M1–M5). Based on LC/MS (liquid chromatography/mass spectrometry) analysis which included the use of H2O and D2O in the mobile phases, they were identified as the sulfoxide (M1), sulfone (M2), carbamoyl glucuronide (M3), N‐glucuronide (M4), and N‐glucoside (M5) metabolites, respectively. The structure of M3, a less commonly seen carbamoyl glucuronide metabolite, was established using on‐line H/D (hydrogen/deuterium) exchange experiments conducted by LC/MS. H/D exchange experiments were also used to distinguish the S‐oxidation structures of M1 and M2 from hydroxylation. Herein, the application of deuterium oxide as the LC/MS mobile phase for structural elucidation of drug metabolites in biological matrices is demonstrated. Copyright © 2001 John Wiley & Sons, Ltd.
Determination of phenoxyacid herbicides and their phenolic metabolites in surface and drinking water
Authors: Marchese Stefano , Perret Daniela , Gentili Alessandra , D'Ascenzo Guiseppe , Faberi Angelo
Published: August 2002

An evaluation was made of the feasibility of using reversed‐phase liquid chromatography/tandem mass spectrometry with an electrospray interface (LC/ESI‐MS/MS) to measure traces of phenoxyacid herbicides and their metabolites in surface and drinking water samples. The procedure involved passing 0.5 L of river and drinking water samples through a 0.5 g graphitized carbon black (GCB) extraction cartridge. Recovery was higher than 85% irrespective of the aqueous matrix in which the analytes were dissolved. A conventional 4.6‐mm i.d. reversed‐phase LC C‐18 column operating with a mobile phase flow rate of 1 mL/min was used to chromatograph the analytes. A flow of 200 µL/min of the column effluent was diverted to the ESI source. The limits of detection (signal‐to‐noise ratio = 3) of the method for the pesticides considered in drinking and surface water samples are less than 0.1 ng/L for phenoxyacid herbicides, and about 5–10 ng/L for their metabolites (2,4‐dichlorophenol and 4‐chloro‐2‐methylphenol). Copyright © 2001 John Wiley & Sons, Ltd.
Studies of human antiviral CD8+ lymphocytes using class I peptide tetramers
Authors: Lechner Franziska , Vargas Cuero Ana L. , Kantzanou Maria , Klenerman Paul
Published: August 2002

Understanding the interactions between a host and a pathogen relies crucially on quantitative measurements of immune reponses. Until recently, measurements of the levels of cellular immune responses, i.e. those mediated by CD4+ and CD8+ T lymphocytes have depended largely on culture in vitro and subsequent measurement of specific functions (such as cytolysis). More recently, new technologies based around tetrameric class I peptide complexes (tetramers) have allowed immunologists to measure CD8+ T lymphocyte levels directly ex vivo and independently of function. Since CD8+ lymphocytes play a key role in a number of important human viral infections, these tools have yielded useful insights into the dynamics, phenotype and function of human antiviral lymphocyte populations. In this review we describe some of the basic aspects of the biology of virus‐specific CD8+ lymphocytes, and the current methods available to detect them. The use of tetramers has, in just four years, transformed our understanding of the immune responses against HIV, HTLV‐1, HBV, HCV, CMV and EBV, and holds promise in a number of areas where quantative analysis of the antiviral reponse in terms of both number and function is critical. Copyright © 2001 John Wiley & Sons, Ltd.
Robust dynamic ship positioning control system design and applications
Authors: Katebi M. R. , Yamamoto Ikuo , Matsuura Masami , Grimble M. J. , Hirayama Hiroaki , Okamoto Norihiko
Published: August 2002

This paper describes the robust control system design for a ship dynamic positioning system. The control design is based on an approximate linear model derived from the nonlinear hydrodynamic equations governing the horizontal motions of the ship. The nonlinear models of the ship, seawaves, current, wind and thrusters are derived and simulated for control design verification. The H∞ control design technique is employed to design the controller. The control problem is formulated in state‐space form and the design specifications are translated into requirements on the weighting functions of the error signal and the thrusters input. A tuning procedure is proposed based on the wind and wave disturbances. The controller is initially tested on the nonlinear ship model and simulation results are presented to demonstrate the robustness of the H∞ controller. Tank tests results are then presented to assess the controller performance. Copyright © 2001 John Wiley & Sons, Ltd.
QFT application for headphone's active noise cancellation
Authors: Yaniv O. , Fried O. , Furst‐Yust M.
Published: August 2002

A quantitative feedback theory design for attenuation of acoustic noise in earphones and headphones is described. Identification including uncertainty is measured for several ears and device location in the ear neighbourhood. Theoretical limitations are discussed. Copyright © 2002 John Wiley & Sons, Ltd.
Mental, physical, and mathematical models in the teaching and learning of physics
Authors: Greca Ileana María , Moreira Marco Antonio
Published: August 2002

In this paper, we initially discuss the relationships among physical, mathematical, and mental models in the process of constructing and understanding physical theories. We adopt the assumption that comprehension in a particular field of physics is attained when it is possible to predict a physical phenomenon from its physical models without having to previously refer to the mathematical formalism. The physical models constitute the semantic structure of a physical theory and determine the way the classes of phenomena linked to them should be “perceived.” Within this framework, the first step in order to understand a phenomenon or a process in physics is to construct mental models that will allow the individual to understand the statements that compose the semantic structure of the theory, being necessary, at the same time, to modify the way of perceiving the phenomena by constructing mental models that will permit him to evaluate as true or false the descriptions the theory makes of them. When this double process is attained concerning a particular phenomenon, in such a way that the “results” of the constructed mental models (predictions and explanations) match those scientifically accepted, one can say that the individual has constructed an adequate mental model of the physical model of the theory. Then, in the light of this discussion, we attempt to interpret the research findings we have obtained so far with college students, regarding mental models and physics education under the framework of Johnson‐Laird's mental model theory. The difficulties faced by the students to achieve the understanding of physical theories did not seem to be all of the same level: some are linked to the constraints imposed to the construction of mental models by students' previous knowledge and others, linked to the ways individuals perceive the world, seem to be much more problematic. We argue that teaching should focus on them, at least at introductory level, considering the explicit teaching of the modelling process or at least its systematic practice as a tool that might be appropriate to facilitate this process. © 2001 John Wiley & Sons, Inc. Sci Ed 86:106–121, 2001.
Refractory ceramic coatings: processes, systems and wettability/adhesion
Authors: Dahotre Narendra B. , Kadolkar Puja , Shah Swapnil
Published: August 2002

Refractory materials such as ceramics and refractory metals/alloys are widely used for structural applications in severe environments where more efficient use of energy is a prime need. Owing to properties such as high strength and refractoriness, low thermal expansion and electric conductivity these materials may be used as turbocharger rotors, valves, valve seats and turbocharger turbine wheels in gas turbine engines, tubes in industrial heat exchangers, fuel elements in nuclear reactors, fusion reactor wall material, tool materials in machining and casting and as electronic packaging. In these applications, however, these materials often experience extreme mechanical, thermal and chemical loading conditions and are expected to perform effectively beyond existing limits. The existing limits of performance for these materials can be extended only via coating technology, which presently appears to be the most suitable technical and economic approach. Thus there remains a critical need to develop a suitable and reliable refractory coating system and coating technique.

In view of the above requirements, the present paper embarks on a brief review of refractory coatings. The review begins with a set of criteria required for an effective refractory coating. The criteria include general thermophysical and mechanical properties for the refractory coating only and properties of the coating–substrate as a system. The review continues with a section on methods of coating. The classification of methods of coating is based on categories such as gaseous, solution, molten/semi‐molten and solid state processes. Each category is explained with conventional and novel techniques and coatings that can be synthesized using these techniques. These categories are supplemented also with examples of applications. A major emphasis has been put on refractory materials in the following section on coating material systems. The most important materials systems have been grouped as oxides and nitrides, carbides, borides, silicides and aluminides. The general properties that make them useful as refractory coatings, along with specific materials and applications, have been reviewed. Wettability and adhesion between coating and substrate are very important for the coating–substrate system to perform effectively and reliably. The last section discusses the fundamentals of wettability and work of adhesion, based on which wetting in metal–metal, metal oxide, metal–carbon/carbide systems has been discussed. Finally, the review sets the motion of thoughts with a description on future developments. Copyright © 2001 John Wiley & Sons, Ltd.
Demand–control–support among female and male managers in eight Swedish companies
Authors: Bernin Peggy , Theorell Töres
Published: August 2002

This work is part of the Swedish project ‘Managers and Stress’. In the report the Swedish version of the Demand–Decision Latitude model was used, which made it possible to compare data with an earlier population study. A total of 179 male and 56 female managers were included. The demands and decision latitude scores were significantly higher than in the population study. Social support buffers high demands but surprisingly the managers did not report higher support than the participants in the population. Psychological demands and skill discretion differed significantly between companies. The hypotheses that psychological demands and decision latitude differ between female and male managers had to be rejected. The period of extensive changes which has taken place in working‐life, especially in the government sector, probably influenced the results. The results did not indicate higher stress in those managers working in the companies that were the most extensive ‘downsizers’. Copyright © 2001 John Wiley & Sons, Ltd.
Role of computerized tomography in the staging of gastrointestinal neoplasms
Authors: Angelelli Giuseppe , Ianora Amato A. Stabile , Scardapane Arnaldo , Pedote Pasquale , Memeo Maurizio , Rotondo Antonio
Published: August 2002

Gastrointestinal neoplasms are very common diseases, and the first challenge for clinicians is to define the extent of the tumor in order to plan the best treatment. The role of computerized tomography in assessing this kind of patient is well established worldwide. This article reviews the capabilities and the limits of this imaging technique in the staging of the tumors of the digestive tract (liver, gallbladder, biliary tract, pancreas, esophagus, stomach, small bowel, and colon). Semin. Surg. Oncol. 20:109–121, 2001. © 2001 Wiley‐Liss, Inc.
Analyses of [18F]altanserin bolus injection PET data. I: Consideration of radiolabeled metabolites in baboons
Authors: Price Julie C. , Lopresti Brian J. , Mason Neale S. , Holt Daniel P. , Huang Y. , Mathis Chester A.
Published: August 2002

Positron emission tomography (PET) has been used to study serotonin 2A (5‐HT2A) receptor binding in human brain using the 5‐HT2A antagonist, [18F]altanserin. Previous analyses of bolus injection [18F]altanserin data provided 5‐HT2A specific binding measures that were highly correlated with the in vitro distribution of 5‐HT2A receptors and reflected decreased binding after ketanserin (5‐HT2A antagonist) administration. These observations were made in the presence of a nonspecific tissue component that was consistent with blood–brain barrier (BBB) passage of radiolabeled metabolites (radiometabolites). In this work, we evaluated the in vivo kinetics of [18F]altanserin and two major radiometabolites of [18F]altanserin, focusing on the kinetics of free and nonspecifically‐bound radioactivity. PET studies were performed in baboons after the bolus injection of [18F]altanserin or one of its major radiometabolites, either [18F]altanserinol or [18F]4‐(4‐fluorobenzoyl)piperidine, at baseline and after pharmacologic receptor blockade (blocking data). The cerebellar and blocking data were analyzed using either single (parent radiotracer) or dual (parent radiotracer and radiometabolites) input function methods. After bolus injection of either [18F]altanserin metabolite, radioactivity crossed the BBB and localized nonspecifically. The radio‐ metabolites were found to contribute to nonspecific “background” radioactivity that was similar in receptor‐poor and receptor‐rich regions. After bolus injection in baboons, two of the major radiometabolites of [18F]altanserin crossed the BBB and contributed to a fairly uniform background of nonspecific radioactivity. This uniformity suggests that conventional analyses are appropriate for human bolus injection [18F]altanserin PET data, although these methods may overestimate [18F]altanserin nonspecific binding. Synapse 41:1–10, 2001. © 2001 Wiley‐Liss, Inc.
Changes in cannabinoid CB1 receptors in striatal and cortical regions of rats with experimental allergic encephalomyelitis, an animal model of multiple sclerosis
Authors: Berrendero Fernando , Sánchez Antonio , Cabranes Ana , Puerta Carmen , Ramos José A. , García‐Merino Antonio , Fernández‐Ruiz Javier
Published: August 2002

Data, initially anecdotal, but recently supported on more solid experimental evidence, suggest that cannabinoids might be beneficial in the treatment of some of the symptoms of multiple sclerosis (MS). Despite this evidence, there are no data on the possible changes in cannabinoid CB1 or CB2 receptors, the main molecular targets for the action of cannabinoids, either in the postmortem brain of patients with MS or in animal models of this disease. The present study addressed this question using the model of experimental allergic encephalomyelitis (EAE) in Lewis rats generated by inoculation of guinea pig myelin basic protein in Freund's adjuvant. After inoculation, animals were examined daily to detect the appearance of neurological signs. The first signs appeared around day 10 after inoculation, reaching the highest degree by day 13, when animals were sacrificed and their brains removed and used for analysis of CB1 receptor binding, mRNA levels, and activation of GTP‐binding proteins. CB1 receptor binding and mRNA levels were not affected in EAE rats in brain areas such as the hippocampus, limbic structures, and cerebellum. However, there was a marked decrease in both parameters in the caudate‐putamen, both in the lateral and medial parts, although this decrease did not correspond with decreases in binding in the nuclei recipient of striatal output neurons, which suggests that changes in CB1 receptors are exclusively located in the cell bodies of striatal neurons. In addition, CB1 receptor binding, but not mRNA levels, also decreased in the cerebral cortex, both in the deep and the superficial layers. The analysis of [35S]GTPγS binding after activation of CB1 receptors with WIN55,212‐2, a synthetic agonist, revealed that, despite the decrease in the number of CB1 receptors in EAE rats, these were more efficiently coupled to GTP‐binding protein‐mediated signaling mechanisms in both the caudate‐putamen and the cerebral cortex of these animals. In summary, these data suggest that the generation of EAE in Lewis rats would be associated with changes in CB1 receptors in striatal and cortical neurons, which might be related to the alleviation of some motor signs observed after the treatment with cannabinoid receptor agonists in similar models of MS in rodents. Synapse 41:195–202, 2001. © 2001 Wiley‐Liss, Inc.
Binding characteristics of selective serotonin reuptake inhibitors with relation to emission tomography studies
Authors: Elfving Betina , Bjørnholm Berith , Ebert Bjarke , Knudsen Gitte Moos
Published: August 2002

When developing ligands for emission tomography studies, one of the major obstacles lies in the selection of ligand candidates. A previously unattended factor such as the influence of temperature on candidate ligand affinity is likely to play a role. By use of rat brain homogenates, the binding characteristics of [3H]‐(S)‐citalopram and [3H]‐(+)‐McN5652 and the receptor‐ligand interaction at the serotonin transporter of 17 selective serotonin reuptake inhibitors were compared at 21°C and 37°C, respectively. Ligand logP values were also calculated. The ratios for Ki at 37°C vs. 21°C varied between 0.2 and 2.2 for the selective serotonin reuptake inhibitors considered in this study, with most of the ligands displaying an inverse relationship between Ki and temperature. Ten of the 17 selective serotonin reuptake inhibitors were found to have pKi values statistically significantly different at 21°C compared to 37°C (P < 0.05). The logP values ranged between 3.6 and 4.8, except for DASB, 5‐iodo‐6‐nitroquipazine, and paroxetine where logP was 1.9, 2.2, and 5.0, respectively. Kd was 0.71 nM at 37°C and 0.31 nM at 21°C for [3H]‐(S)‐citalopram. For [3H]‐(+)‐McN5652 Kd was 0.11 nM at 37°C and 0.08 nM at 21°C. The association and dissociation was much faster for [3H]‐(S)‐citalopram as compared to [3H]‐(+)‐McN5652. It is concluded that temperature may affect Kd differently and that in vitro dissociation may help to predict whether a given ligand may be useful in PET studies. LogP values do not per se predict the potential of a given ligand as an emission tomography tracer. Synapse 41:203–211, 2001. © 2001 Wiley‐Liss, Inc.
Energy‐based damage assessment on structures during earthquakes
Authors: Wong Kevin K. F. , Wang Yumei
Published: August 2002

Several seismic damage indices have been developed using the energy concept in attempt to compensate for the inadequacy of ductility criteria. However, these indices are either based on implicitly defined energy as a cumulative effect on ductility or are unable to consider energy in a quantitative manner. In this paper, a method of assessing the structural performance during earthquakes based on both explicitly computed plastic rotation and plastic energy at every hinge of a moment‐resisting frame is proposed. This method uses the force analogy method to evaluate the structural response and energy in the inelastic domain. Inelastic deformation is expected to occur during major earthquakes, and active control based on an instantaneous optimal control algorithm is used to improve the structural performance. Comparisons are made between uncontrolled response and instantaneous optimal control response based on a single‐degree‐of‐freedom system to demonstrate the computation of plastic energy. Damage analysis of a six‐storey moment‐resisting steel frame is then presented to evaluate the performance and applicability of the proposed damage measure. Results show that the proposed damage assessment criteria are feasible and that active control can reduce plastic rotation and plastic energy, thereby reducing damage to a certain acceptable limit. Copyright © 2001 John Wiley & Sons, Ltd.
Evaluation of chromosomal aberrations, micronuclei, and sister chromatid exchanges in hospital workers chronically exposed to ionizing radiation
Authors: Cardoso R.S. , Takahashi‐Hyodo S. , Peitl P. , Ghilardi‐Neto T. , Sakamoto‐Hojo E.T.
Published: August 2002

Cytogenetic analysis was performed in peripheral blood lymphocytes from hospital workers chronically exposed to ionizing radiation in comparison to matched non‐exposed individuals. The accumulated absorbed doses calculated for the radiation workers ranged from 9.5 to 209.4 mSv. The endpoints used were chromosomal aberrations (CA), micronuclei (MN), and sister chromatid exchanges (SCE). The frequencies of CA/100 cells observed for the exposed group were significantly (P=0.018) higher than in the control group: 3.2 and 2.6, respectively. Similarly, the mean numbers of SCE per cell were statistically higher (P=0.025) in the exposed group (6.2) in comparison with the control group (5.8). In the case of micronuclei analysis, no significant (P=0,06) difference between both groups was found, but these data should be cautiously interpreted since an increase in the frequencies of MN was found for radiation workers (3.0 MN/100 cells), compared to the control group (2.6 MN/100 cells) and this increase occur in parallel to CA and SCE frequencies. The difference between the results could be explained by the nature of CA and MN generation. The increased frequencies of CA and SCE in radiation workers indicate the cumulative effect of low‐level chronic exposure to ionizing radiation, and the relevance of conducting cytogenetic analysis in parallel to physical dosimetry in the working place. Teratogenesis Carcinog. Mutagen. 21:431–439, 2001. © 2001 Wiley‐Liss, Inc.
Learning and using science ideas when doing investigate‐and‐redesign tasks: A study of naive, novice, and expert designers doing constrained and scaffolded design work
Authors: Crismond David
Published: August 2002

This study reports on what naive, novice, and expert designers do and learn when investigating simple mechanical devices and then planning their redesign. Participating in the study were 32 high school and adult subjects who did two investigate‐and‐redesign (I&R) tasks. Same gender pairs of subjects with similar design experiences explored, analyzed, and evaluated different brands of a device, designed experiments to compare them, and then proposed their redesign. Each two‐hour session was videotaped, and portions were analyzed using methods adapted from protocol analysis techniques. Results suggest that when naive designers do I&R tasks, their learning is highly contextualized and device‐specific. Naive designers made few connections from their work to key science ideas, and instead used mechanical advantage preconceptions that they did not spontaneously redress during the I&R sequence. Experts made connections to concepts and cases, inferred key design decisions, and sought “critical design problems” for the devices studied. All groups used strategies involving analysis more than those involving synthesis or evaluation. Notably, during conceptual design, opportunities for using science, present especially when subjects analyze design ideas, went underutilized by nonexpert designers. Scaffolded questions are needed to focus the learning of science embedded in design‐oriented activities. All findings reported are tentative, given the limited number of cases included in this study. © 2001 John Wiley & Sons, Inc. J Res Sci Teach 38: 791–820, 2001
Aerodynamic analysis of HAWTs operating in unsteady conditions
Authors: Masson Christian , Smaïli Arezki , Leclerc Christophe
Published: August 2002

This article presents a numerical method for predicting unsteady aerodynamics of horizontal axis wind turbines (HAWTs). In this method the flow field is described by the unsteady incompressible Navier–Stokes equations. The rotor and tower are idealized respectively as actuator disc and flat plate permeable surfaces on which external normal surficial forces are balanced by fluid pressure discontinuities. The external forces exerted by the rotor and tower on the flow are prescribed according to blade element theory. Dynamic behaviour of the rotor aerodynamic characteristics is simulated using either the Gormont or the Beddoes–Leishman model. The resulting mathematical formulation is solved using a control volume finite element method. The fully implicit scheme is used for time discretization. In general, the proposed method has demonstrated its capability to adequately represent the field data. It has been demonstrated that the accuracy of the predicted results depends primarily on the dynamic stall model as well as on the turbulence model employed. Copyright © 2001 John Wiley & Sons, Ltd.
Quantitative determination of metals in radish using x‐ray fluorescence spectrometry
Authors: Anjos M. J. , Lopes R. T. , Jesus E. F. O. , Simabuco S. M. , Cesareo R.
Published: August 2002

Using energy‐dispersive X‐ray fluorescence analysis with a Ti‐filtered x‐ray tube it was possible to determine the concentrations of several elements, such as K, Ca, Ti, Mn, Fe, Cu, Zn, Br, Rb, Sr, Zr and Pb, at ppm levels in radish plants (root and foliage) cultivated in soils treated with concentrations of 10, 20 and 30 t ha−1 of organic compost from urban garbage. A significant increase was observed in the concentrations of K, Ca, Mn, Fe, Zn, Rb and Pb in radish plants cultivated in the treated soils in comparison with a control soil. The results suggest that radish plants can be used as bioindicator of contamination of agricultural soils. Copyright © 2002 John Wiley & Sons, Ltd.
Surgical Strategy for Cystic Diseases of the Liver in a Western Hepatobiliary Center
Authors: Ammori Basil J. , Jenkins Benjamin L. , Lim Phillip C.M. , Prasad K. Rajendra , Pollard Stephen G. , Lodge J. Peter A.
Published: August 2002

The aim of this study was to define the indications and evaluate the results of various management options in patients with cystic liver disease. Between 1992 and 1999 we managed 60
consecutive patients with cystic liver disease. Diagnoses included a simple cyst (solitary 12, multiple 10), adult polycystic liver disease
(APLD 17), Caroli’s disease (8), hydatid cysts (4), and neoplastic cysts (9). Half of the patients with simple cysts had mild or no symptoms and required no treatment. Percutaneous drainage in eight patients (simple cyst 4, APLD 4) was followed by symptomatic recurrence in three. Laparoscopic deroofing in three patients (multiple simple cysts 2, APLD 1) was followed by symptomatic enlargement of the remaining cysts that required further intervention (laparoscopic deroofing 2, transplantation 1). Laparoscopic hepatectomy was successful in three patients with solitary simple cysts. Of 18 patients who underwent open hepatic resection (neoplastic 8, Caroli’s 4, simple cysts 3, hydatid cysts 2, APLD 1), 2 patients with Caroli’s disease required liver transplantation for disease progression. Nine patients
(Caroli’s 5, APLD 4) underwent liver transplantation, and three had a concomitant renal transplant. Seven patients developed complications,
and three died (5%). Cholangiocarcinoma developed in three patients with bilateral Caroli’s disease, and all died. Radiologic treatment has a limited role in the management of patients with simple cysts or APLD. Laparoscopic deroofing of simple cysts may have to be repeated,
whereas resection minimizes cyst recurrence. Unilobar Caroli’s disease may be resected, whereas bilateral disease requires early liver transplantation owing to the high risk of malignancy. Transplantation is a reserved option in patients with extensive APLD.
Intraoperative Parathyroid Aspiration and Parathyroid Hormone Assay as an Alternative to Frozen Section for Tissue Identification
Authors: Perrier Nancy D. , Ituarte Philip , Kikuchi Shoichi , Siperstein Allan E. , Duh Quan Yang , Clark Orlo H. , Gielow Robert , Hamill Timothy
Published: August 2002

Most people would agree that successful parathyroidectomy depends on two important variables: the surgeon's recognition and excision of the abnormal parathyroid gland(s) and the pathologist's confirmation that the removed tissue is parathyroid tissue. Frozen section is usually employed to confirm the identity of parathyroid tissue, but occasionally confirmation cannot be made without a permanent section, as with intrathyroidal glands. This study proposes a new method of expeditious and easy confirmation of parathyroid tissue utilizing the immunoassay for quick measurement of intraoperative parathyroid hormone (IOPTH). By directly aspirating the suspected adenoma, the assay becomes a rapid diagnostic tool that can be used as an alternative to frozen section. In cases where the surgeon is already planning to employ the assay, the elimination of frozen section is cost‐effective. Intraoperative aspiration of histologically confirmed parathyroid adenomas was performed on 12 consecutive patients undergoing parathyroid surgery. Parathyroid glands were aspirated with a 22‐gauge syringe after gland excision. Aspirates were placed in 1 to 3 ml of buffered saline. A similar process was performed on 12 thyroid controls. Specimens were centrifuged, aliquotted, and stored at −70°C. The parathyroid hormone value was analyzed electively by rapid assay and the values recorded. For all parathyroid aspirates, the rapid assay value was > 1500 pg/ml, exceeding the uppermost limit of the diagnostic chart. Values for thyroid aspirates ranged from 58 to 85 pg/ml (mean 75.7 pg/ml). In all cases tissue confirmation was achieved with permanent section. Values were 100% sensitive and specific. Measurement of PTH from intraoperative aspiration of suspected parathyroid adenomas is clinically useful in patients for whom frozen section would routinely be employed. Values > 1500 pg/ml secure the tissue diagnosis. There is no additional cost in cases where IOPTH monitoring is already being utilized to confirm cure. The elimination of frozen section could be cost‐effective and, for some institutions, actually decrease the operating time as the IOPTH assay takes only 15 minutes. PTH assay is an accurate diagnostic technique and to date is 100% sensitive and specific for differentiating between parathyroid tumors and thyroid nodules.
Laparoscopic versus Open Appendectomy: Prospective Randomized Trial
Authors: Hansen John Brendan , Smithers Bernard Mark , Schache David , Wall Daryl Robert , Miller Brian John , Menzies Betty Lynette
Published: August 2002

A prospective randomized trial comparing laparoscopic appendectomy with open appendectomy in patients with a diagnosis of acute appendicitis was conducted between October 1992 and April 1994. Of the 158 patients randomized, 7 patients were excluded because of protocol violations (conversion to laparotomy in 4, appendix not removed in 3). The 151 patients randomized to either a laparoscopic (n= 79) or an open appendectomy (n= 72) showed no difference in sex, age, American Society of Anesthesiology (ASA) rating, or previous abdominal surgery. The histologic classification of normal, catarrhal, inflamed, suppurative, and gangrenous appendicitis was not different between the two groups. Conversion from laparoscopic to open appendectomy was necessary in seven patients (9%) who had advanced forms of appendiceal inflammation. When compared to open appendectomy the laparoscopic group had a longer median operating time (63 minutes versus 40 minutes), fewer wound infections (2% versus 11%), less requirement for narcotic analgesia, and an earlier return to normal activity (median 7 days versus 14 days). There was no difference in morbidity, and both groups had a median time to discharge of 3 days. Laparoscopic appendectomy is as safe as open appendectomy; and despite the longer operating time, the advantages such as fewer wound infections and earlier return to normal activity make it a worthwhile alternative for patients with a clinical diagnosis of acute appendicitis.
Laparoscopic Cholecystectomy for Acute Cholecystitis: Is It Really Safe?
Authors: Kum Cheng‐Kiong , Eypasch Ernst , Lefering Rolf , Paul Andreas , Neugebauer Edmund , Troidl Hans
Published: August 2002

The prospectively collected data from 530 cholecystectomies performed in a university clinic from October 1989 to March 1991 were analyzed after 1 to 3 years of follow‐up. The aim of this study was to compare the results of laparoscopic cholecystectomy (LC) for acute cholecystitis with that for routine symptomatic gallbladders. The preoperative, intraoperative, and postoperative parameters of 424 routine (noninflamed) LCs and 54 LCs for acutely inflamed gallbladders were compared under the “intention to treat” principle. Operating time was longer in the inflamed group (median 97 minutes versus 75 minutes; p< 0.0001). Significantly more adhesions (20% versus 8%), more blood loss (48% versus 19%), a higher incidence of bile spillage (28% versus 12%), and lost stones (19% versus 8%) were encountered in patients with acute cholecystitis. Common bile duct (CBD) injuries were also more frequent in that group (5.5% versus 0.2%;p= 0.005). The rate of conversion to open surgery was higher than with routine LCs (13% versus 4%). There were two deaths in the routine LC group and none in the acutely inflamed group. There was no difference in postoperative pain intensity or postoperative fatigue according to visual analog scale measurements. Patients with acute cholecystitis stayed only 1 day longer (median 4 days versus 3 days) in hospital. The quality of life scores indicate return to almost normal values by the 14th postoperative day. Long‐term follow‐up (1–3 years) did not reveal any delayed clinical adverse effects. In summary, LC for inflamed gallbladders has a higher conversion rate than LC for routine symptomatic gallbladders. If successfully performed, it has definite benefit for the patient in terms of better postoperative recovery. The trade‐off is that the risk of CBD injury is significantly higher.
Carcinoid Tumors: Imaging Procedures and Interventional Radiology
Authors: Wallace Sidney , Ajani Jaffer A. , Charnsangavej Chusilp , DuBrow Ronelle , Yang David J. , Chuang Vincent P. , Carrasco C. Humberto , Dodd Gerald D.
Published: August 2002

The hypervascular nature of carcinoid tumors and their metastases allows a more aggressive role by the radiologist in diagnosis and interventional management. Double‐contrast gastrointestinal studies still best define the primary neoplasms. Appendiceal tumors, the most frequent site of carcinoids, frequently escape radiologic detection until large enough to be discovered by computed tomography (CT). Superior mesenteric arteriography of the small bowel and cecum is useful when the scanning procedures are not revealing. The “spokewheel” configuration of the desmoplastic mesenteric masses and lymph node metastases are best seen by CT, whereas hepatic metastases can be demonstrated by CT, CT‐angioportography (CTAP), ultrasonography (US), magnetic resonance imaging (MRI), and octreotide scintigraphy. Percutaneous needle biopsy with radiologic guidance confirms the diagnosis of carcinoid tumors and their metastases. Hepatic arteriography is frequently performed in preparation for hepatic embolization or chemoembolization. Hepatic vascular occlusion therapy, the procedure of choice for the management of inoperable carcinoid liver metastases, results in a partial response in at least 50% of patients and a mortality rate of 5%. Chemoembolization with microencapsulated cytotoxic agents and direct percutaneous ethanol injection should also be considered for the treatment of liver metastases.
Gastric Carcinoids and Neuroendocrine Carcinomas: Pathogenesis, Pathology, and Behavior
Authors: Rindi Guido , Bordi Cesare , Rappel Sigrid , La Rosa Stefano , Stolte Manfred , Solcia Enrico
Published: August 2002

The goal of this study was to provide information of prognostic value for gastric endocrine tumors. A total of 205 gastric endocrine tumors have been studied: 193 well differentiated tumors [2 gastrin cell tumors, 191 enterochromaffin‐like (ECL) cell tumors] and 12 poorly differentiated carcinomas. Subtyping of ECL cell tumors (carcinoids) resulted in 152 associated with chronic atrophic gastritis (CAG) (type 1); 12 associated with hypertrophic gastropathy (HG) due to Zollinger‐Ellison syndrome with multiple endocrine neoplasia type I (type 2), and 27 with no specific association (type 3, sporadic). Type 1 cases occurred most often in female (108 of 152), elderly (mean 63 years) patients, with no tumor‐related death at an overall mean follow‐up of 53 months. The 12 type 2 cases were equally distributed between the sexes (six of each), with a mean age of 45 years; there was one tumor‐related death (49 months after diagnosis) and an overall mean survival of 84 months. Type 3 cases were mostly in men (20 of 27), with a mean age of 55 years; there were seven tumor‐related deaths at a mean follow‐up of 28 months. Poorly differentiated neuroendocrine carcinomas were observed in elderly patients (mean 63 years, range 41–76 years) of both sexes, with nine tumor‐related deaths and a mean survival of 7 months. It was concluded that correct clinicopathologic subtyping may predict the clinical behavior of gastric endocrine tumors.
Pattern of Organ Failure following Severe Trauma
Authors: Regel Gerd , Grotz Martin , Weltner Tobias , Sturm Johannes A. , Tscherne Harald
Published: August 2002

Multiple organ failure (MOF) is considered to be the leading cause of death after severe trauma. Although there is extensive literature on MOF, little is known about the pattern, sequence, and onset of this clinical syndrome. The first goal of this clinical study was to define MOF; the second was to assess the typical onset, sequence, and pattern of MOF; and the third was to define certain risk factors for the development of MOF in 342 multiple trauma patients. Patients with an Injury Severity Score (ISS): > 20 (mean 35.7) were included. Three well established MOF scoring methods were used to give strict definitions of MOF: 11.4% of the total patient population developed MOF, and 88.6% did not. Respiratory failure was most frequent in patients developing MOF (74.4%), and these patients had the highest mortality rate (65.5%) compared to patients with failure of other organ systems (liver, cardiovascular system). Generally, the lung is the first organ to fail after injury (failure after 3.7 ± 2.8 days). Significant renal failure and the need for dialysis decreased to < 5%; other signs of organ dysfunction (gastric, central nervous system) are difficult to verify. Typical risk factors for the development of MOF after severe trauma are the severity, type, and distribution of injury as well as the indicators of prolonged hemorrhagic shock (elevated lactate levels). The main therapeutic efforts, therefore, should be the effective treatment of traumatic hemorrhagic shock during the initial phase, adequate resuscitation, optimal oxygenation, and early surgical treatment.
Progression of Metastases and Symptom Improvement from Laparotomy in Midgut Carcinoid Tumors
Authors: Makridis Charlie , Rastad Jonas , Öberg Kjell , Åkerström Göran
Published: August 2002

A total of 121 consecutive patients with midgut carcinoid tumors underwent regular clinical control and 158 laparotomies for abdominal symptoms with 1 to 11 years (mean 5.2 years) of follow‐up. Metastases were present in 93% of the patients at study inclusion and developed at initially uninvolved sites with an overall probability of 0.38. Patients without initial tumor spread developed mesenteric or liver metastases with the probability of 0.25 (mean delay 12 years), whereas those with mesenteric metastases exhibited a probability 0.56 to develop liver metastases (mean delay 6.1 years). Spread to extraabdominal sites in patients with mesenteric and liver metastases exhibited a probability of 0.22 (mean delay 4.3 years), and this spread was especially frequent (probability 0.60) in patients with only liver metastases at inclusion. Patients without the carcinoid syndrome (52%) mainly suffered from more or less episodic abdominal pain, nausea, and diarrhea. Marked mesenteric fibrosis detected at surgery (n= 59) generally was accompanied by symptoms of abdominal pain and weight loss, and it often required urgent intervention due to intestinal obstruction or ischemia. Complete or partial symptom alleviation was accomplished in 82% of the operated patients, and generally was most auspicious after primary acute or subacute procedures (n= 54). The complete or partial symptom improvements after surgery lasted for mean 5.3 years and tended to be longer after elective (n= 50) than acute operations. The findings substantiate encouraging results of laparotomy in a compromised cohort of patients with midgut carcinoid tumors. Because the patients also displayed a generally slow progression of metastases, liberal indications for laparotomy should prevail in symptomatic and possibly also asymptomatic individuals with midgut carcinoid tumors.
Teaching Effectiveness of the Advanced Trauma Life Support Program as Demonstrated by an Objective Structured Clinical Examination for Practicing Physicians
Authors: Ali Jameel , Cohen Robert , Adam Rasheed , Gana Theophilus J. , Pierre Ian , Bedaysie Henry , Ali Ernest , West Undine , Winn Jennifer
Published: August 2002

Although the Advanced Trauma Life Support (ATLS) course is now taught internationally, its teaching effectiveness still requires confirmation. The Objective Structured Clinical Examination (OSCE) reliably assesses clinical performance by utilizing standardized patients. An OSCE of eight 15 minute trauma patient stations and two 40 item MCQ tests were used to test the teaching effectiveness of the ATLS program in 32 practicing physicians who applied for an ATLS program in Trinidad and Tobago. The physicians were randomly assigned to an ATLS group (n= 16) that completed the ATLS course and a non‐ATLS group (n= 16). Before and after the ATLS course, all physicians completed MCQ tests and trauma OSCE. Mean (± SD) OSCE scores (standardized to 20) ranged from 9.8 ± 1.7 to 10.0 ± 1.7 and 9.5 ± 1.8 to 10.8 ± 1.3 in the ATLS and non‐ATLS groups, respectively, prior to the ATLS course (NS). Post‐ATLS OSCE scores ranged from 15.9 ± 1.7 to 17.6 ± 1.7 in the ATLS group (p< 0.05 compared to pre‐ATLS) and 9.5 ± 1.4 to 10.1 ± 1.3 in the non‐ATLS group, which did not improve their OSCE scores. Adherence to priorities was graded 1 to 7 with the pre‐ATLS grades of 1.7 ± 0.6 (ATLS) and 1.8 ± 0.7 (non‐ATLS) and post‐ATLS grades of 6.4 ± 1.1 (ATLS) and 2.1 ± 0.6 (non‐ATLS). Organized approach to trauma was graded 1 to 5 with pre‐ATLS grades of 1.6 ± 0.5 (ATLS) and 1.7 ± 0.6 (non‐ATLS) and post‐ATLS grades of 4.5 ± 0.6 (ATLS) and 1.9 ± 0.6 (non‐ATLS). Pre‐ATLS MCQ scores (%) were similar: 53.1 ± 8.4 (ATLS) and 57.3 ± 5.4 (non‐ATLS), but post‐ATLS scores were greater in the ATLS group: 85.8 ± 7.1 (ATLS) and 64.2 ± 3.6 (non‐ATLS). Our data support the teaching effectiveness of the ATLS program among practicing physicians as measured by improvement in OSCE scores, adherence to trauma priorities, maintenance of an organized approach to trauma care, and cognitive performance in MCQ examinations.
Cost of open versus laparoscopically assisted right hemicolectomy for cancer
Authors: Philipson Bertil M. , Bokey E. Leslie , Moore James W. E. , Chapuis Pierre H. , Bagge Eva
Published: August 2002

The aim of this study was to estimate and compare the costs of open right hemicolectomy (ORHC) versus laparoscopically assisted right hemicolectomy (LARHC) performed for cancer. A retrospective cost analysis of 61 consecutive patients operated on between January 1992 and August 1994 for right‐sided colonic cancer by either LARHC (n = 28) or ORHC (n = 33) was performed. The analysis focused on the cost (in Australian dollars) incurred from the date of operation to the date of discharge. LARHC was significantly more expensive than ORHC (total cost LARHC $9064, ORHC $7881; p < 0.001). LARHC was associated with a significantly longer operating room utilization time (LARHC 261 minutes, ORHC 203 minutes; p < 0.001) and a greater cost of disposables (LARHC $854, ORHC $189; p < 0.001). This study demonstrates no cost benefit for LARHC compared to ORHC when performed for cancer.