bluuebunny/crossref_metadata_2025 huggingface dataset:
Systems hierarchies and management
Authors: Martinelli Dante P.
Published: August 2002

In this paper, 18 systems taxonomies/hierarchies are presented and commented upon, from Boulding's ‘system of systems’ (1956) to Glasl and Lievegoed's ‘seven essential elements of any organization’ (1993). A 19th is proposed, which aims at displaying a number of clear‐cut levels sufficient to correspond to the succeeding levels of an enterprise problematique, each new type of interactions defining a new level. The 19 schemes are classified into two groups, ‘General’ and ‘Managerial’, mainly according to their immediate applicability to management. Each group was split into two subgroups, respectively stressing complexity, system–milieu interactions, decision levels and, finally, intrasystem and system environment interactions. A comparative analysis of the whole set is summarized, converging towards three hierarchies seen as more adequate: Beer's, Jantsch's and the one proposed in this paper. Copyright © 2001 John Wiley & Sons, Ltd.
Minimal residual disease in soft‐tissue sarcomas
Authors: Willeke Frank , Sturm Joerg W.
Published: August 2002

Soft‐tissue sarcomas are characterized by the development of disease recurrence in a distinct subgroup of patients. Despite intense efforts in applying multimodal treatment, the risk of local recurrence or distant metastases remains a considerable threat to patients with soft‐tissue sarcoma. This review focuses on the efforts aimed at defining local and systemic tumor extent at the level of minimal residual disease (MRD) tumor cell detection. Examination of MRD in soft‐tissue sarcomas has experienced a significant boost from the definition of fusion transcripts resulting from stable chromosomal translocations. The sensitivity and exclusive specificity of the reverse‐transcription polymerase chain reaction (RT‐PCR) protocols have given insights into tumor cell residues in nearly all body compartments. The accumulated data demonstrates that even after oncologic resections most patients will still harbor a significant tumor burden. Clinical concepts arising out of these new data are under way. One of these concepts is the targeting of the fusion transcript for therapy. However, this approach is still restricted to the experimental setting. The development of clinical applications remains a challenging task, requiring the treatment of as many patients as possible in centers specializing in all of the affected disciplines. Semin. Surg. Oncol. 20:294–303, 2001. © 2001 Wiley‐Liss, Inc.
Molecular detection and characterization of circulating tumor cells and micrometastases in prostatic, urothelial, and renal cell carcinomas
Authors: Ghossein Ronald A. , Bhattacharya Satyajit
Published: August 2002

The detection and molecular characterization of circulating tumor cells (CTCs) and micrometastases in urinary tract and prostatic tumors may have important prognostic and therapeutic implications. In the last decade, numerous groups have attempted the detection of occult tumor cells in renal, prostatic, and urothelial carcinomas using the highly sensitive reverse‐transcriptase polymerase chain reaction (RT‐PCR). In prostatic carcinoma (PC), tissue‐specific transcripts were detected with high specificity in the blood of patients with localized and advanced disease. PCR assays for PC detection were shown to be strong predictors of poorer outcome in some reports, while a lack of prognostic significance was found in other studies. There was a vast difference in the PCR positivity rates between various groups studying PC. This discrepancy could be due to variations in PCR methodology. In urothelial and renal cell carcinoma, the amount of research on the subject is still too limited. Currently, these assays for occult tumor cells are promising but are not yet ready to use in PC and urinary tract tumors. Because of the many limitations of PCR (e.g., false positives), many groups are developing new approaches for the detection of occult tumor cells. The most attractive technique involves immunomagnetic isolation of intact CTC and micrometastases prior to downstream analysis. The tumor‐rich magnetic fraction can be subjected to RT‐PCR, immunocytochemistry, and in situ hybridization. This will lead to better quantification and molecular characterization of these tumor cells. Semin. Surg. Oncol. 20:304–311, 2001. © 2001 Wiley‐Liss, Inc.
Preservation of rectal function after low anterior resection with formation of a neorectum
Authors: Brown Steven R. , Seow‐Choen Francis
Published: August 2002

Recent advances in surgery have enabled low rectal cancers to be resected, while at the same time restoring bowel continuity and preserving the anal sphincter. Although a permanent stoma is avoided and the operation is oncologically sound, function may be compromised. Many patients with a straight coloanal anstomosis suffer from urgency, incontinence, and bowel frequency—the so‐called anterior resection syndrome. Over the last 15 years, surgical developments have aimed at improving function after restoration of bowel continuity, essentially by creating a neorectum. The best known and most widely practiced operation involves formation of a colonic J‐pouch. The physiological and functional outcomes of the colonic J‐pouch are discussed, along with controversies surrounding construction. Although a J‐pouch improves some aspects of function, the results are not perfect. Alternatives to the colonic J‐pouch are appraised, indicating future areas of development. Semin. Surg. Oncol. 19:376–385, 2000. © 2000 Wiley‐Liss, Inc.
ATGen: automatic test data generation using constraint logic programming and symbolic execution†
Authors: Meudec Christophe
Published: August 2002

The verification and validation of software through dynamic testing is an area of software engineering where progress towards automation has been slow. In particular the automatic design and generation of test data remains, by and large, a manual activity. This is despite the high promises that the symbolic execution technique engendered when it was first proposed as a method for automatic test data generation. This paper presents an automatic test data generator based on constraint logic programming and symbolic execution. After reviewing the symbolic execution technique, approaches for the resolution of the technical difficulties that have so far prevented symbolic execution from reaching its full potential in the area of automatic test data generation are presented. ATGen, an automatic test data generator, based on symbolic execution and that uses constraint logic programming, is then discussed. Copyright © 2001 John Wiley & Sons, Ltd.
Striatal dopamine output is compromised within +/− BDNF mice
Authors: Dluzen Dean E. , Anderson Linda I. , McDermott Janet L. , Kucera Jan , Walro Jon M.
Published: August 2002

We reported previously that mice lacking one brain‐derived neurotrophic factor (BDNF) allele demonstrate elevated striatal dopamine (DA) concentrations but impaired behavioral responses involving the nigrostriatal dopaminergic (NSDA) system. To test the hypothesis that these elevated striatal DA concentrations are associated with perturbed NSDA functioning, we compared striatal DA output between heterozygous mutant (+/−) and wild‐type littermate control (+/+) BDNF mice under conditions of an intact NSDA system, as well as following methamphetamine (MA)‐induced neurotoxicity. Basal DA output from superfused CS tissue fragments did not differ between +/+ and +/− BDNF mice. Potassium (K+) stimulated DA outputs from intact striatal fragments of +/+ mice were significantly greater than that of +/− BDNF mice. Following MA treatment, K+ stimulated DA output of +/+ mice was statistically equivalent to +/− BDNF mice. Striatal DA concentrations of +/− BDNF mice were elevated, albeit not significantly, in both intact and MA‐treated mice relative to +/+ mice. Following MA treatment, striatal DA concentrations were significantly decreased for both genotypes; however, the degree of DA depletion was significantly greater in +/+ mice. Analyzed collectively, these data show the differential effects exerted by a BDNF mutation upon striatal DA concentrations and output. Notably, lower striatal DA concentrations of +/+ vs. +/− BDNF mice can be contrasted with the significantly greater K+ stimulated DA output from the former. This difference was abolished following MA treatment. These results suggest that processes involved with the dynamics of DA release within the NSDA system may be compromised in +/− BDNF mutant mice. Synapse 43:112–117, 2002. © 2001 Wiley‐Liss, Inc.
Bacterial photosynthesis begins with quantum‐mechanical coherence
Authors: Sumi Hitoshi
Published: August 2002

In the antenna system of photosynthetic bacteria, pigments form circular aggregates whose excitations are excitons with quantum‐mechanical coherence extending over many pigments. These excitons play crucial roles in light harvesting, storage, and excitation‐energy transfer (EET). EET takes place rapidly to and/or from optically forbidden exciton states, without total transition dipole, within the antenna system and to the reaction center. Such EETs cannot be rationalized by Förster’s formula, the traditional theory on EET, because it allows EET only between optically allowed states. The coherence in the excitons seems to prohibit rapid EET on this formula. The bacteria overcome this difficulty by circumventing the coherence, using the effects of the physical size of an aggregate that is larger than the shortest distance between pigments in the donor and pigments in the acceptor. The shortest‐distance pair therein cannot detect whether the aggregate has a nonvanishing total transition dipole or not, since the pair see effectively only the transition dipole on the other pigment in themselves. The transition dipole facilitates rapid EET even to and/or from optically forbidden exciton states. Such EETs have enabled us to develop a general formula for the rate constant of EET. This is a formula in the weak‐interaction limit, and so is Förster’s formula, but it correctly takes into account the above size effect. © 2001 John Wiley & Sons, Inc. and The Japan Chemical Journal Forum Chem Rec 1:480–493, 2001
Erratum: Release of enzyme strain during catalysis reduces the activation energy barrier
Authors: Kagamiyama Hiroyuki , Hayashi Hideyuki
Published: August 2002

In the aforementioned article, the wrong version of the first paragraph in the section entitled “Quantitative Analysis of the Relationship between the Torsion and pKa of the PLP‐Lys258 Aldimine” was printed. Please find the correct version printed below. We apologize to our readership and the authors for this regrettable error.
Lessons on and from the dihybrid cross: An activity–theoretical study of learning in coteaching
Authors: Roth Wolff‐Michael , Tobin Kenneth , Zimmermann Andrea , Bryant Natasia , Davis Charles
Published: August 2002

During their training, future teachers usually learn the subject matter of science. However, they are largely left on their own when it comes to figuring out how to teach this subject matter, that is, how to find appropriate pedagogical forms. In this article we present a model of collective teaching and learning, which we term coteaching/cogenerative dialoguing, as a way to build deep learning of science concepts while learning about alternative ways to teach the same subject matter. As praxis, coteaching brings about a unity between teaching and learning to teach; cogenerative dialoguing brings about a unity between teaching and researching. Both are potential sites for deep learning. We articulate coteaching/cogenerative dialoguing in terms of activity theory and the associated first‐person research methodology that has been developed by critical psychologists as a method of choice for dealing with the theory–praxis gap. Our detailed case study highlights opportunities of learning subject matter and pedagogy by university professors who participate in coteaching/cogenerative dialoguing in an urban high school. © 2002 Wiley Periodicals, Inc. J Res Sci Teach 39: 253–282, 2002
A modeling approach to teaching evolutionary biology in high schools*
Authors: Passmore Cynthia , Stewart Jim
Published: August 2002

There are numerous empirical reports in the science education literature documenting the difficulty students have in understanding evolution, in particular natural selection. Unfortunately, because of the nature of empirical reports, much detail about the instruction that students in these studies received is seldom provided. In this article we describe the commitments and research that went into the design of a 9‐week high school course in evolutionary biology. This course was designed to bring students to an understanding of the practice of evolutionary biology by engaging them in developing, elaborating, and using one of the discipline's most important explanatory models—Darwin's model of natural selection. This article is not an empirical report on student understanding but is instead a description of our view of what constitutes understanding in evolution and of a curriculum designed from this perspective. Examples of student work are used to add richness to the description of the course as well as to illustrate the potential for sophisticated reasoning that exists when students are given the opportunity and conceptual tools to engage in realistic inquiry. © 2002 Wiley Periodicals, Inc. J Res Sci Teach 39: 185–204, 2002
Underprivileged urban mothers' perspectives on science
Authors: Barton Angela Calabrese , Hindin Toby J. , Contento Isobel R. , Trudeau Michelle , Yang Kimberley , Hagiwara Sumi , Koch Pamela D.
Published: August 2002

The purpose of this article is to report our findings from a qualitative study intended to develop our understandings of how inner‐city mothers perceive science. Using qualitative methodologies, our analysis reveals that the mothers' perceptions can be grouped into four categories: perceptions of science as (a) schoolwork/knowledge, (b) fun projects, (c) a tool for maintaining the home and family, and (d) an untouchable domain. After we present these categories we compare our findings across categories to argue that those mothers who had spent time doing science with their children were more likely to have a more personal, dynamic, and inquiry‐based view of science. We also argue that mothers' perceptions of science were more dynamic when they spoke about situations and contexts that were familiar to them, such as food, nutrition, and child care. We conclude the article with a discussion of the implications our findings have for science education reform. © 2001 John Wiley & Sons, Inc. J Res Sci Teach 38: 688–711, 2001
The GDI1 genes from Kluyveromyces lactis and Pichia pastoris: cloning and functional expression in Saccharomyces cerevisiae
Authors: Brummer Mirko H. , Richard Peter , Sundqvist Lena , Väänänen Ritva , Keränen Sirkka
Published: August 2002

The nucleotide sequences of 2.8 kb and 2.9 kb fragments containing the Kluyveromyces lactis and Pichia pastoris GDI1 genes, respectively, were determined. K. lactis GDI1 was found during sequencing of a genomic library clone, whereas the P. pastoris GDI1 was obtained from a genomic library by complementing a Saccharomyces cerevisiae sec19‐1 mutant strain. The sequenced DNA fragments contain open reading frames of 1338 bp (K.lactis) and 1344 bp (P. pastoris), coding for polypeptides of 445 and 447 residues, respectively. Both sequences fully complement the S. cerevisiae sec19‐1 mutation. They have high degrees of homology with known GDP dissociation inhibitors from yeast species and other eukaryotes. The GenBank Accession Nos of the sequences are AF255332 (K.lactis GDI1) and AY007574 (P. pastoris GDI1). Copyright © 2001 John Wiley & Sons, Ltd.
Malo‐ethanolic fermentation in grape must by recombinant strains of Saccharomyces cerevisiae
Authors: Volschenk H. , Viljoen‐Bloom M. , Subden R. E. , van Vuuren H. J. J.
Published: August 2002

Recombinant strains of Saccharomyces cerevisiae with the ability to reduce wine acidity could have a significant influence on the future production of quality wines, especially in cool climate regions. L‐Malic acid and L‐tartaric acid contribute largely to the acid content of grapes and wine. The wine yeast S. cerevisiae is unable to effectively degrade L‐malic acid, whereas the fission yeast Schizosaccharomyces pombe efficiently degrades high concentrations of L‐malic acid by means of a malo‐ethanolic fermentation. However, strains of Sz. pombe are not suitable for vinification due to the production of undesirable off‐flavours. Heterologous expression of the Sz. pombe malate permease (mae1) and malic enzyme (mae2) genes on plasmids in S. cerevisiae resulted in a recombinant strain of S. cerevisiae that efficiently degraded up to 8 g/l L‐malic acid in synthetic grape must and 6.75 g/l L‐malic acid in Chardonnay grape must. Furthermore, a strain of S. cerevisiae containing the mae1 and mae2 genes integrated in the genome efficiently degraded 5 g/l of L‐malic acid in synthetic and Chenin Blanc grape musts. Furthermore, the malo‐alcoholic strains produced higher levels of ethanol during fermentation, which is important for the production of distilled beverages. Copyright © 2001 John Wiley & Sons, Ltd.
Use of a YAP1 overexpression cassette conferring specific resistance to cerulenin and cycloheximide as an efficient selectable marker in the yeast Saccharomyces cerevisiae
Authors: Akada Rinji , Shimizu Yoshirou , Matsushita Yuji , Kawahata Miho , Hoshida Hisashi , Nishizawa Yoshinori
Published: August 2002

Drug‐resistance markers for yeast transformation are useful because they can be applied to strains without auxotrophic mutations. However, they are susceptible to technical difficulties, namely lower transformation efficiency and the appearance of drug‐resistant mutants without the marker. To avoid these problems, we have constructed a phosphoglycerate kinase (PGK) promoter‐driven YAP1 expression cassette, called PGKp–YAP1. Yeast cells containing PGKp–YAP1 were resistant to cycloheximide, a protein synthesis inhibitor, and also to cerulenin, a fatty acid synthesis inhibitor, but not to other drugs tested. The transformation efficiency of PGKp–YAP1 using cerulenin selection was comparable to that using a URA3 auxotrophic marker when low concentrations of cerulenin were used. Non‐transformed drug‐resistant colonies did appear on the low‐concentration cerulenin plates. However, these non‐transformed colonies could easily be identified, based on their cycloheximide sensitivity and/or their resistance to aureobasidin A to which the transformants were sensitive. Therefore, the dual drug resistance of PGKp–YAP1 could be used as an effective selection for PGKp–YAP1 recipient cells. The PGKp–YAP1 marker was used to disrupt the LYS2 gene and to transform an industrial yeast strain, indicating that this marker can be used for efficient and reliable gene manipulations in any Saccharomyces cerevisiae strain. Copyright © 2002 John Wiley & Sons, Ltd.
Molecular characterization of the Hansenula polymorphaFLD1 gene encoding formaldehyde dehydrogenase
Authors: Baerends Richard J. S. , Sulter Grietje J. , Jeffries Thomas W. , Cregg James M. , Veenhuis Marten
Published: August 2002

Glutathione‐dependent formaldehyde dehydrogenase (FLD) is a key enzyme required forthe catabolism of methanol as a carbon source and certain primary amines, such as methylamine as nitrogen sources in methylotrophic yeasts. Here we describe the molecular characterization of the FLD1 gene from the yeast Hansenula polymorpha. Unlike the recently described Pichia pastoris homologue, the H. polymorpha gene does not contain an intron. The predicted FLD1 product (Fld1p) is a protein of 380 amino acids (ca. 41 kDa) with 82% identity to P. pastoris Fld1p, 76% identity to the FLD protein sequence from n‐alkane‐assimilating yeast Candida maltosa and 63–64% identity to dehydrogenase class III enzymes from humans and other higher eukaryotes. The expression of FLD1 is strictly regulated and can be controlled at two expression levels by manipulation of the growth conditions. The gene is strongly induced under methylotrophic growth conditions; moderate expression is obtained under conditions in which a primary amine, e.g. methylamine, is used as nitrogen source. These properties render the FLD1 promoter of high interest for heterologous gene expression. The availability of the H. polymorpha FLD1 promoter provides an attractive alternative for expression of foreign genes besides the commonly used alcohol oxidase promoter. The sequence has been deposited in the GenBank/NCBI data library under Accession No. AF364077. Copyright © 2002 John Wiley & Sons, Ltd.
Marker construction and cloning of a cut1‐like sequence with ARS activity in the fission yeast Schizosaccharomyces japonicus
Authors: Bozsik Aniko , Szilagyi Z. , Benko Z. , Sipiczki M.
Published: August 2002

The dimorphic fission yeast Schizosaccharomyces japonicus has proved to be an excellent experimental model for the investigation of the eukaryotic cell. Here we show that it has a haplontic life cycle, in which the diploid phase is confined to the zygote. To make it amenable to genetic and molecular analysis, we generated genetic markers and cloned a genomic sequence which acts as ars when integrated into a plasmid. Diploids suitable for testing complementation and recombination between markers can be formed by protoplast fusion. The complementation tests and the recombination frequencies determined in octads of spores identified 28 non‐allelic groups (genes) of mutations of the auxotrophic and mycelium‐negative mutants. Two groups of linked markers were also identified. The cloned fragment, which expresses ars activity, encodes a putative amino acid sequence highly similar to a conserved domain of proteins Cut1 (Schizosaccharomyces pombe), BimB (Aspergillus nidulans) and Esp1 (Saccharomyces cerevisiae). Copyright © 2002 John Wiley & Sons, Ltd.
Extensive subcutaneous emphysema following arthroscopy: a case report
Authors: Deshmukh N. , Shah M.
Published: August 2002

We report an unusual presentation of delayed subcutaneous emphysema of the thigh following arthroscopy with a fluid medium, which was managed conservatively. This rare presentation must be recognised by all orthopaedic surgeons practising arthroscopic surgery.
Tightening elongated ACL grafts by application of bipolar electromagnetic energy (ligament shrinkage)
Authors: Spahn G. , Schindler S.
Published: August 2002

In ACL transplants showing elongation with functional deficit but no interruption of structure (Marburg Arthroscopic Score type III) there is the possibility of reinsertion, augmentation, or revision ACL reconstruction to stabilize the joint. Bipolar electromagnetic energy can be used to induce the tightening of elongated ACL transplants. We examined 14 patients with a secondary instability after ACL transplantation (mean 23.6 months). During arthroscopy a type III transplant without signs of nonisometric position was found. The elongated transplants were treated by bipolar application probe. All knees where protected by an unlimited orthosis over a period of 12 weeks. Postoperative follow‐up took 9.4 months. There was a significant improvement in subjective discomforts (35.9 to 88.5 points on the Lysholm score), and the Rollimeter test showed a reduction of the ventral tibial translation (13.1 to 2.6 mm). There was a correlation between the degree of chondral damage and a Lysholm score but not between subjective discomforts and the degree of instability. Our findings confirm that elongated ACL transplants can be tightened by applying bipolar electromagnetic energy during rearthroscopy, thus avoiding revision ACL reconstruction in some cases.
Prevalence of Postcholecystectomy Symptoms: Long‐term Outcome after Open versus Laparoscopic Cholecystectomy
Authors: Peterli Ralph , Schuppisser Jean P. , Herzog Urs , Ackermann Christoph , Tondelli Peter E.
Published: August 2002

After cholecystectomy a certain number of patients continue to suffer from abdominal symptoms or develop such symptoms postoperatively. The aim of this study was to compare the prevalence of postcholecystectomy symptoms with open cholecystectomy during the prelaparoscopic era and those with laparoscopic cholecystectomy 4 years after introduction of the laparoscopic technique. Between July 1988 and June 1989 a total of 163 consecutive patients with elective open cholecystectomy and between September 1994 and August 1995 a total of 234 consecutive patients with elective laparoscopic cholecystectomy were prospectively evaluated using a standard questionnaire about preoperative symptoms, diagnostic modalities, and intraoperative findings. After a minimum of 12 months the patients were interviewed by telephone. Since the introduction of the minimal invasive technique the number of cholecystectomies performed at our institution increased. There was no significant difference in the prevalence of postcholecystectomy symptoms found after the open procedure compared with laparoscopic cholecystectomy: 90% of patients after open and 94% after laparoscopic cholecystectomy had no or only minor symptoms.
Potential Strategies for Inflammatory Mediator Manipulation: Retrospect and Prospect
Authors: Fisher Charles J. , Zheng Yunli
Published: August 2002

Sepsis syndrome and septic shock remain significant causes of morbidity and mortality. To date, clinical trials of novel agents to treat sepsis have failed to demonstrate clinical efficacy despite considerable animal data to suggest a positive therapeutic benefit. This article reviews the recent major clinical trials on sepsis and discusses the hypotheses on which these therapies are based and the critical issues associated with clinical sepsis. Recommendations for future clinical trials on sepsis are made.
The pivotal role of John S. Edkins in the discovery of gastrin
Authors: Modlin Irvin M. , Kidd Mark , Marks I. N. , Tang Laura H.
Published: August 2002

John Sydney Edkins was born in London in 1863. After gaining two open scholarships, he attended Caius College, Cambridge and studied physiology under the tutelage of J.N. Langley and M. Foster. During this period he published on the chemical nature of pepsinogen with Langley. After qualifying as a medical doctor, he worked in Manchester before returning to London, where he succeeded E. Klein as Head of Physiology at St. Bartholomew's. For financial reasons he also worked part time at Bedford College for Women. In 1902 Bayliss and Starling overturned Pavlov's doctrine of the nervous regulation of gastrointestinal function by discovering the pancreatic secretagogue secretin—the first identifiable chemical messenger. Edkins applied a similar rationale to the stomach and in a classic series of experiments noted that injection of a pyloric mucous membrane extract resulted in gastric acid and pepsin secretion in anesthetized cats. In 1905 he named this putative active agent “gastrin.” Although his ideas were initially accepted, the discovery of histamine in 1910 and the identification that extracts from other tissues had a similar physiologic effect raised serious questions regarding the validity of the existence of gastrin. Somewhat discouraged, Edkins pursued the teaching and training of women physiologists at Bedford College, where he later became Chairman of Physiology. Outside of science he successfully pursued other interests and became President of the British Croquet Association. The demonstration that gastrin was a unique antrat stimulant of acid secretion by Komarov in 1938 was followed by the purification and elucidation of its chemical structure by Gregory and Tracy in 1964. Their work allowed final validation of Edkins’ original hypothesis. Edkins died in London in 1940, not only fated to predecease the vindication of his hypothesis but unable to witness the evolution of his discovery into a paradigm for the hormonal regulation of secretory and proliferative cellular activity.
Hepatic Steatosis in Liver Transplant Donors: Common Feature of Donor Population?
Authors: García Ureña Miguel Angel , Ruiz‐Delgado Francisco Colina , González Enrique Moreno , Romero Carlos Jiménez , García Ignacio García , Segurola Carmelo Loinzaz , González‐Pinto Ignacio , Sanz Ramón Gómez
Published: August 2002

Fatty change in donor livers is a risk factor for poor function after orthotopic liver transplantation. Various prevalences of steatosis have been reported in time 0 biopsies. The aim of this research was to determine, in a longitudinal study, the degree (percent of hepatocytes involved) and type (size of vacuoles) of fatty change shown by various histologic techniques. Four staining methods were used on sections from three liver wedge biopsies—at liver procurement, at the back‐table, and after reperfusion—from 83 consecutive donor livers. Results in Sudan III‐stained (SS) sections showed the greatest sensitivity (87.1%), negative predictive value (91.8%), and agreement rate (κ= 0.77) when compared with results in thin (1 μm) plastic‐embedded toluidine blue‐stained (TBS) sections. High‐grade steatosis (>30% steatotic hepatocytes) was identified in 49.4% of SS sections, 46.9% of TBS sections, 38.5% of frozen hematoxylin‐eosin (H&E)‐stained sections, and 20.7% of deparaffinated H&E‐stained sections. Microscopic observations disclosed two types of steatotic pattern: (1) A predominantly small‐droplet lipid vacuolzation (high‐grade microsteatosis), similar to the steatosis associated with Reye syndrome, was seen in 29% of SS sections and 25% of TBS sections—approximately one‐fourth of grafts; and (2) a combined pattern of large and small fat drops (high‐grade macromicrosteatosis) was seen in 20% of SS sections and 22% of TBS sections. We concluded that moderate to severe steatosis is a frequent finding in donor livers. The difficulty in detecting lipidic microvacuoles in H&E‐stained sections may be the reason for underestimating the grade of fatty change or even for diagnosing as normal some biopsies with high‐grade microsteatosis.
Traumatic Rupture of the Aortic Isthmus: Program of Selective Management RID="" ID="" This International Association for the Surgery of Trauma and Surgical Intensive Care (IATSIC) article was presented at the 37th World Congress of Surgery International Surgical Week (ISW97), Acapulco, Mexico, August 24–30, 1997.
Authors: Pate James W. , Gavant Morris L. , Weiman Darryl S. , Fabian Timothy C.
Published: August 2002

Two hypotheses were investigated: (1)
helical computed tomography (CT) of the chest on victims of decelerating trauma can yield a diagnosis of, or “rule out,” a traumatic rupture of the aorta (TRA) without the need for an aortogram;
and (2) selective delay of aortic repair can be safely accomplished through a medical management protocol. Screening helical CT examinations were done on 6169 victims of blunt thoracic trauma; 47 were found to have TRA; in 8, indirect but nondiagnostic findings not clarified by an aortogram led to surgical exploration. The sensitivity of helical CT was higher than that of aortograms, and a “normal”
helical CT scan was never associated with a proved TRA. It is estimated that the use of helical CT has resulted in at least a 40% to 50%
decrease in the need for aortograms, in addition to yielding rapid, noninvasive valuable information about other injuries. Drugs
(β‐blockers ± vasodilators) to decrease the stress in the aortic wall were used in 93 patients when the diagnosis was suspected and were continued as necessary through the evaluation, stabilization, and until the aorta was cross‐clamped at operation. Elective, delayed operation was done between 2 days and 25 months in 15 patients who were deemed to be excessive risks for emergency aortic repair; there were 2 deaths (13.3%). Eleven patients never had aortic repair. No patient maintained on this protocol, whether repaired emergently, electively, or not at all, developed free rupture of the periaortic hematoma and death from TRA.
Ethical Problems in Surgery: Innovation Leading to Unforeseen Complications
Authors: McKneally Martin F.
Published: August 2002

A hypothetical case that involves a surgical innovation is used to illustrate three ethical issues in surgery: the profound trust that vulnerable patients feel toward their surgeons, even when they innovate; the disequilibrating effect of new procedures on traditional safeguards of surgical competence; and the need for a systematic approach to the evaluation of new surgical procedures.
A Fundamental Aspect of Supportive Care Delivery: The Nurse's Opportunity to Shape the Caring Encounter
Authors: Bakke Andrea , King Deborah
Published: August 2002

Recent advances in supportive care therapies have significantly contributed to the likelihood that a child diagnosed with cancer will be cured. Quantitatively recognized supportive care practices, such as central line care management, pain control, nutritional support, and blood transfusions are typically identified as the major contributors to these improved rates of survival. However, just as important are the more qualitative aspects of the nursing care delivery process. As a fundamental part of nursing's caring role, the encounter with patients and families offers unique opportunities for nurses to participate in the creation of a healing environment. Gaining understanding and skill at balancing professional relationships, while also knowing the risks of caring, are critical components of providing excellent supportive care to pediatric oncology patients and their families. The professional caring encounter is a complex and multidimensional process. Strategies for developing optimal communication and healthy profes sional caring relationships within the pediatric oncology setting are discussed.
Use of Pelvic Flexure Biopsies to Predict Survival After Large Colon Torsion in Horses
Authors: Van Hoogmoed Linda , Snyder Jack R. , Pascoe John R. , Olander Harvey
Published: August 2002

Objective—To determine if morphologic evaluation of intraoperative biopsies of the large colon could be used to accurately predict outcome in horses with large colon torsion.

Study Design—Clinical study.

Animals—Fifty‐four horses with large colon torsion.

Methods—A full‐thickness biopsy was collected from the pelvic flexure of the ascending colon after correction of naturally occurring colonic torsion. Morphologic changes were evaluated and graded for interstitial tissue to crypt ratio (I:C ratio), percentage loss of superficial and glandular epithelium, and the degree of hemorrhage and edema. These variables were then used to predict survival.

Results—Morphologic variables could be used to correctly predict survival or death in 51 horses (P < .0001). This corresponded to a sensitivity of 95.1% (82.2%‐99.2%; 95% CI) and a specificity of 92.3% (62.0%‐99.6%; 95% CI). Of 6 horses that had colonic resection, 5 survived; an accurate prediction of outcome based on morphologic criteria was made for each horse.

Conclusions—Interpretation of changes in colonic morphology can be used to accurately predict postoperative survival in horses with large colon torsion.

Clinical Relevance—Use of frozen colonic tissue sections is a rapid, reliable, and relatively inexpensive method for assessing morphologic damage associated with large colon torsion during surgery. Intraoperative evaluation of pelvic flexure biopsies can aid in the prediction of survival and guide surgical judgment as to the need for colonic resection.
Comparison of Bone Healing by Demineralized Bone Matrix and Autogenous Cancellous Bone in Horses
Authors: Kawcak Christopher E. , Trotter Gayle W. , Powers Barbara E. , Park Richard D. , Turner A. Simon
Published: August 2002

Objective—The purpose of this study was to compare bone healing induced by equine demineralized bone matrix (DBM) to autogenous cancellous bone graft (ACB) or no graft (control) in a rib‐defect model in horses.

Study Design—The osteogenic properties of ACB and DBM were evaluated in bilateral 19‐mm circular defects created in the outer cortex of the 6thand 8thribs of each horse.

Animals or Sample Population—Eight mature horses.

Methods—Three rib defects in each horse were randomly treated with each of the 3 treatment groups, and the fourth rib defect received a random treatment. Rib sections, including the defects, were harvested 56 days after implantation and examined for bone mineral density, percent ash and calcium and graded for signs of radiographic and histological healing.

Results—All ribs were fractured at the defect site and were classified as nonunion fractures 56 days after implantation. There were no significant differences among groups in bone mineral density and signs of radiographic or histological healing. There was an increased volume of bone in control and ACB‐treated sites compared with DBM‐treated sites. Rib defects treated with ACB were significantly higher in percent ash and calcium than those treated with DBM. DBM elicited no inflammatory reaction, and remodeling occurred around the periphery and within vascular channels of the decalcified particles.

Conclusion—DBM particles remodel from the periphery, which may explain the significantly lower percent ash, calcium, and bone when compared with ACB, because 2‐ to 4‐μL pieces of DBM may act as space‐occupying masses until completely mineralized. There was no evidence of enhanced healing associated with the use of DBM in this model.

Clinical Relevance—Particles of 2 to 4 mm DBM should not be used as an aid to fracture repair because particles of this size interfere with normal mineralization. However, our model of nonunion fracture healing may be useful in future studies.
In Vitro Evaluation of the Effect of Dimethyl Sulfoxide on Equine Articular Cartilage Matrix Metabolism
Authors: Smith Christine L. , Macdonald Melinda H. , Tesch Anthony M. , Willits Neil H.
Published: August 2002

Objective—To evaluate the effects of dimethyl sulfoxide (DMSO) on equine articular cartilage matrix metabolism.

Study Design—Using a cartilage explant culture system, proteoglycan (PG) synthesis, PG release, lactate metabolism, chondrocyte viability, and metabolism recovery were determined after cartilage exposure to DMSO.

Sample PopulationCartilage harvested from metacarpophalangeal and metatarsophalangeal joints of 12 horses (age range, 1 to 10 years).

Methods—Explants were exposed to concentrations of DMSO (1% to 20%) for variable times (3 to 72 hours). PG synthesis and release were determined by a radiolabel incorporation assay and dimethylmethylene blue (DMMB) dye assay, respectively. Lactate released into culture media was measured, and chondrocyte viability was assessed using the Formizan Conversion Assay and a paravital staining protocol. Metabolism recovery was assessed in explants that were allowed to recover in maintenance media after exposure to DMSO.

Results—PG synthesis and lactate metabolism were inhibited in a dose‐ and time‐dependent manner after exposure to DMSO concentrations > 5%; there was no significant alteration in PG release. No change in chondrocyte viability was detected after incubation with DMSO. PG synthesis and lactate metabolism returned to baseline rates when allowed a recovery period after exposure to DMSO.

Conclusions—DMSO concentrations > 5% suppress equine articular cartilage matrix metabolism. Suppression of PG synthesis and lactate metabolism is reversible and does not appear to be the result of chondrocyte death.

Clinical Relevance—Equine clinicians adding DMSO to intraarticular lavage solutions should be aware that DMSO may have deleterious effects on equine articular cartilage matrix metabolism.
Transarterial Coil Embolization of the Internal and External Carotid and Maxillary Arteries for Prevention of Hemorrhage From Guttural Pouch Mycosis in Horses
Authors: Léveillé Renée , Hardy Joanne , Robertson James T. , Willis A. Michelle , Beard Warren L. , Weisbrode Steven E. , Lepage Olivier M.
Published: August 2002

Objectives—To develop a transarterial coil embolization technique for occlusion of the internal carotid artery (ICA), external carotid artery (ECA), and maxillary arteries (MA) in normal horses and to evaluate this technique for prevention of hemorrhage in horses affected with guttural pouch mycosis.

Animals—Ten adult, normal horses and 4 horses with guttural pouch mycosis.

Methods—All horses had transarterial coil embolization of the rostral and caudal ICA, caudal MA, and rostral ECA. In 1 affected horse, an aberrant actively bleeding branch of the ECA was also occluded. Normal horses had a premortem angiogram, and were killed either at 1 or 2 weeks or 1, 2, or 3 months after the procedure. Specimens from the ICA, ECA and MA were evaluated by light microscopy.

Results—No surgical complications were observed, except 1 horse that developed laryngeal hemiplegia and 1 pilot horse that had embolization of the cerebral arterial circle. In normal horses, premortem angiography confirmed complete occlusion of all vessels, and coils were positioned as intended. All normal horses had partially maturing to mature, continuous thrombi occluding at the coils. In affected horses, no further episodes of epistaxis were observed. By day 60, all mycotic plaques had resolved without further treatment. Ophthalmic complications were not observed.

Conclusion—Transarterial embolization provided a safe, rapid, and effective method for ICA, ECA, and MA occlusion in normal and affected horses. In affected horses, the technique was possible despite active bleeding, allowing adequate identification and occlusion of all sources of hemorrhage.
Fibrous Tissue of Subchondral Cystic Lesions in Horses Produce Local Mediators and Neutral Metalloproteinases and Cause Bone Resorption in Vitro
Authors: Von Rechenberg Brigitte , Guenther Harald , McIlwraith C. Wayne , Leutenegger Christian , Frisbie Dave D. , Akens Margarete K. , Auer Jörg A.
Published: August 2002

Objectives—To define the release of nitric oxide (NO), prostaglandin E2 (PGE2), and the neutral metalloproteinases (NMPs) in horses with subchondral cystic lesions (SCL) and to study bone resorption triggered by conditioned media of fibrous tissue of SCL in vitro.

Study Design—Equine explant cultures of fibrous tissue of SCL, and synovial membrane and articular cartilage of normal horses and horses affected with moderate and severe osteoarthritis were performed. NO, PGE2, and NMP concentrations of media samples were measured, and osteoclast formation and activation was studied in vitro.

Animals—Experiment 1: 32 horses with SCL (n = 8), normal joints (7), and joints with moderate (7) and severe (10) osteoarthritis (OA). Experiment 2: 22 horses with SCL (n = 3), normal joints (7), and chip fractures (12). Experiment 3: Conditioned media of fibrous tissue from 3 horses with SCL of the medial femoral condyle (n = 1), distal metacarpal bone (1), and tarsal bone (1).

Methods—Determinations of local mediator concentrations were made with the Griess assay for NO and an enzyme immunoassay kit for PGE2 concentrations in biological fluids. Enzyme activities were assessed with radiolabeled substrates indicating collagenolytic, gelatinolytic, and caseinolytic activities. The resorption pit assay was used to assess osteoclast recruitment and activity.

Results—Fibrous tissue of SCL produced NO, PGE2, and NMPs. Of all the variables measured, PGE2 concentrations were the highest in cystic tissue of SCL compared with synovial membrane and articular cartilage from normal joints and joints with chip fractures, indicating that this mediator may play an important role in pathological bone resorption associated with SCL. These findings were supported by the observation that conditioned media of SCL tissue were capable of recruiting osteoclasts and increasing their activity.

Conclusion—Fibrous tissue of SCL released NO, PGE2, and NMPs into the culture media. It is suspected that intralesional fibrous tissue may play an active role in the pathological process of bone resorption occurring in SCL in horses and may be partly responsible for the maintenance, slow healing rate, and expansion of these lesions.

Clinical relevance—Understanding the pathogenesis of SCL will help to establish successful therapy in horses affected with SCL.
Comparison of Trochlear Block Recession and Trochlear Wedge Recession for Canine Patellar Luxation Using a Cadaver Model
Authors: Johnson Allen L. , Probst Curtis W. , Decamp Charles E. , Rosenstein Diana S. , Hauptman Joe G. , Weaver Brian T. , Kern Teri L.
Published: August 2002

Objective—To compare trochlear block recession (TBR) to trochlear wedge recession (TWR) with regards to patellar depth (percentage of patellar volume under the trochlear ridges), patellar articular contact, percentage of recessed trochlear surface area, and resistance to patellar luxation.

Study Design—In vitro computed tomography (CT) and biomechanical evaluation using a cadaver model.

Sample Population—Twelve normal, large‐breed canine cadavers.

Methods—Bilateral pelvic limb specimens with intact stifle joints were mounted on a positioning device. The femoral trochlear ridges were reduced to provide a standard shallow trochlea. TBR or TWR was performed to a standard depth randomly on paired specimens. CT and biomechanical evaluations were performed pre‐ and postoperatively in both an extended (148°) and flexed (113°) stifle position. CT images were digitized and measurements made using an image‐analysis software program. Biomechanical testing consisted of applying 40° of internal tibial rotation and documenting patellar luxation.

Results—The change in trochlear depth (depth of recession) was not significantly different between groups. In the extended stifle position (patella in the proximal trochlea), patellar depth and patellar articular contact with the recessed trochlea were significantly greater after TBR compared with TWR. The percentage of recessed trochlear surface area was significantly greater after TBR compared with TWR. In the extended position, a smaller percentage of the patellae luxated within 40° of internal tibial rotation after TBR compared with TWR.

Conclusions—TBR increases proximal patellar depth, increases patellar articular contact with the recessed proximal trochlea, recesses a larger percentage of trochlear surface area, and results in a greater resistance to patellar luxation in an extended position as compared with TWR.

Clinical Relevance—TBR may help limit the development of stifle DJD in dogs treated for canine patellar luxation.
Endogenous Nitric Oxide Production in Canine Osteoarthritis: Detection in Urine, Serum, and Synovial Fluid Specimens
Authors: Spreng David , Sigrist Nadja , Schweighauser Ariane , Busato André , Schawalder Peter
Published: August 2002

Objective—To measure nitric oxide (NO) concentrations in serum, urine, and synovial fluid (SF) of dogs with naturally occurring cranial cruciate ligament (CCL) rupture and normal dogs, and to compare these with clinical and histologic changes of osteoarthritis (OA).

Study Design—Prospective clinical study including 2 groups of animals selected from the hospital population.

Animals—Forty‐three dogs (CCL group) with OA secondary to CCL rupture; 30 healthy dogs (control group) without CCL rupture.

Methods—Serum, urine, and SF were collected before and during surgery in the CCL group or immediately after euthanasia in the control group. Articular cartilage and synovial membrane tissue specimens were prepared for routine histologic examination. The stable end products of NO, total nitrite and nitrate (NOt) activity, were measured in body fluids and compared with macroscopic and histologic degrees of OA. Urinary NOt concentration was compared with urinary creatinine concentration and stated as urinary NOt:creatinine ratio (UNCR).

Results—SF NOt concentrations were not significantly different between the 2 groups. Serum NOt concentrations (45.6 vs 28.9 μmol/L;P= .042) and the UNCR (0.007 vs 0.004;P= .035) were significantly higher in dogs of the CCL group compared with the control population. An association between UNCR and histologic and macroscopical OA grades could be demonstrated.

Conclusion—UNCR might be a useful indicator of nitrite and nitrate production and, therefore, osteoarthritic changes in joints.

Clinical Relevance—UNCR could be used as a tool to evaluate the NOt production by joint tissues over time and might therefore provide a method of evaluating the effects of drugs in the control of osteoarthritis.