bluuebunny/crossref_metadata_2025 huggingface dataset:
Top manager and network effects on the adoption of innovative management practices: a study of TQM in a public hospital system
Authors: Young Gary J. , Charns Martin P. , Shortell Stephen M.
Published: August 2002

This paper reports findings from a study that combined two theoretical perspectives—top manager and network/institutional—to examine the factors influencing organizations to adopt innovative management practices. The study setting was a system of public hospitals and the innovation was Total Quality Management (TQM). Study results indicate that both top manager and network/institutional factors are important determinants of whether and when organizations adopt innovations. However, as predicted, the relative importance of these two sets of factors appears to change as an innovation becomes more widely diffused. Copyright © 2001 John Wiley & Sons, Ltd.
Intelligent organizations: an integrative framework
Authors: Schwaninger Markus
Published: August 2002

The purpose of this paper is to demonstrate how cybernetic theories open new paths towards organizational intelligence. This is illustrated by means of three theoretical models from organizational cybernetics. These models are integrated into a framework for a virtuous design, (self‐)control and (self‐)transformation of organizations. It is proposed that changes in activities, structure and behaviour—three of the dimensions of this framework—have to be synchronized among one another, and aligned with a fourth dimension: fundamental parameters such as organizational identity, ethos and vision. It is also claimed that a continued and integrative application of the models outlined can trace the path towards excelling organizational intelligence more effectively than merely punctual uses of one or more of them. Copyright © 2001 John Wiley & Sons, Ltd.
Low frequency noise and whole‐body vibration cause increased levels of sister chromatid exchange in splenocytes of exposed mice
Authors: Silva M.J. , Dias A. , Barreta A. , Nogueira P.J. , Castelo‐Branco N.A.A. , Boavida M.G.
Published: August 2002

Chronic exposure to low frequency (LF) noise and whole‐body vibration (WBV) induces both physiological and psychological alterations in man. Recently, we have shown that long‐term occupational exposure to LF noise and WBV produces genotoxic effects in man expressed as an increase in sister chromatid exchange (SCE) levels in lymphocytes. The objectives of the present study were to investigate whether the observed effect could be reproduced in a murine model and, if so, which of the agents, LF noise alone or in combination with WBV, would be instrumental in the SCE induction. SCEs were analyzed in spleen lymphocytes of mice exposed to LF noise alone and in combination with WBV for 300 and 600 hr. An effect at the cell cycle kinetics level was also investigated. The results revealed significant increases in the mean SCE number per cell and in the proportion of cells with high frequency of SCEs (HFCs) in lymphocytes of mice submitted to combined noise and WBV over controls. No significant differences were found between single noise‐exposed and control mice. A cell cycle delay was observed exclusively in the noise and WBV exposure groups. In conclusion, we demonstrated that, as in exposed workers, prolonged exposure to the combination of LF noise and WBV determines an increase in SCE level in mice while LF noise alone is not effective in SCE induction. Teratogenesis Carcinog. Mutagen. 22:195–203, 2002. © 2002 Wiley‐Liss, Inc.
Evaluation of relationship between chromosome 22 and p53 gene alterations and the subtype of meningiomas by the interphase‐FISH technique
Authors: Yakut Tahsin , Bekar Ahmet , Doygun Muammer , Acar Hasan , Egeli Unal , Ogul Erhan
Published: August 2002

In this study, we investigated the relationship between genetic alterations such as chromosome 22 aneuploidy and p53 gene deletion, and the pathological types of meningioma of typical and aggressive forms. Thirty‐four meningiomas (23 typical and 11 aggressive) were examined by application of fluorescence in situ hybridization (FISH) with chromosome 22 specific alpha satellite probe and a combination of p53 locus specific and chromosome 17 centromere specific alpha satellite probes, to evaluate the chromosome 22 aneuploidy and gain or loss of p53 gene along with chromosome 17. The results showed that, although chromosome 22 aneuploidy was seen in 7 out of 23 typical (30.4%) and 4 out of 11 aggressive meningiomas (36.3%), no p53 deletion was detected in typical meningiomas, and p53 deletion was detected in 3 out of 11 aggressive meningiomas (1 atypical and 2 malignant), which had recurrence. There were no simultaneous occurrences of p53 gene deletions between typical and aggressive meningiomas. The present findings indicate that the loss of chromosome 22 may be involved with tumorogenesis of typical and aggressive meningiomas, while p53 gene deletions may be involved with malignant progression and recurrence in the aggressive meningiomas. Teratogenesis Carcinog. Mutagen. 22:217–225, 2002. © 2002 Wiley‐Liss, Inc.
“It's the nature of the beast”: The influence of knowledge and intentions on learning and teaching nature of science*
Authors: Schwartz Reneé S. , Lederman Norman G.
Published: August 2002

This study examined the knowledge, intentions, and instructional practices of two beginning secondary science teachers as they learned the subject matter of nature of science (NOS) and attempted to teach NOS during their student teaching experience and during their first year of full‐time teaching. This is a case study comparison of two success stories. However, the reasons for and levels of success are as varied as the factors that influence teaching practice. Details of the participants' progression, along with descriptions of the challenges they faced in the learning and teaching of NOS offer insight into the complexity of the fulfillment of one's instructional intentions. The results of the study suggest that depth of NOS understanding, subject‐matter knowledge, and the perceived relationship between NOS and science subject matter affected the participants' learning and teaching of NOS. The views of NOS as an inherent part of all science content or as “the nature of the beast” facilitated the inclusion of NOS within traditional science content lessons. The participant with the more extensive science background, who also held well‐developed NOS views, was better able to address NOS throughout his teaching. His subject‐matter knowledge enabled him to use a variety of examples to enhance NOS instruction. The other participant's more limited subject‐matter knowledge and compartmentalized view of NOS seemed to inhibit her incorporation of relevant NOS topics within a traditional science content. The importance of subject‐matter knowledge, NOS knowledge, and NOS instruction intentions to the development of pedagogical content knowledge for NOS and the actualization of intentions in the classroom are discussed. © 2002 Wiley Periodicals, Inc. J Res Sci Teach 39: 205–236, 2002
Structural characteristics of university engineering students' conceptions of energy*
Authors: Liu Xiufeng , Ebenezer Jazlin , Fraser Duncan M.
Published: August 2002

This study examined structural characteristics of university engineering students' conceptions of energy elicited through paragraph writing and their relations with categories of their conceptions specific to energy in solution processes identified through interviews. We found that structures of students' conceptions are characterized primarily by characteristic, example‐of/type‐of, and lead‐to types of relations, and these relations correspond with categories of students' conceptions. More specifically, categories of students' conceptions are exclusively related to energy transformation, and students failed to apply the notion of energy conservation demonstrated in structures of their conceptions to explain the temperature change in solution processes. It is concluded that although paragraph writing and interviews solicit different student conceptions, the conceptions identified from the two sources are related and paragraph writing tends to provide a more holistic picture of students' conceptions. This conclusion has clear implications for science curriculum development and instruction. © 2002 Wiley Periodicals, Inc. J Res Sci Teach 39: 423–441, 2002
The unrealized potential of everyday technology as a context for learning
Authors: Benenson Gary
Published: August 2002

This four‐part article argues that technology education should play a far more substantial role in the schools. In the first section the article broadly defines the term technology to include the artifacts of everyday life as well as environments and systems. Second is a description of the City Technology Curriculum Guides project, of which most of the thinking in this article is a product. The third section presents a comprehensive set of goals for elementary technology education, using classroom examples from City Technology. Many of these goals coincide with the goals of other school subjects, including math, science, English language arts and social studies. The concluding section suggests a broad role for technology education in providing a context for learning in these areas. © 2001 John Wiley & Sons, Inc. J Res Sci Teach 38: 730–745, 2001
Sex differences in the prevalence of human birth defects: A population‐based study
Authors: Lary Joseph M. , Paulozzi Leonard J.
Published: August 2002

Background

Sex differences in the prevalence of several human birth defects have often been reported in the literature, but the extent of sex differences for most birth defects is unknown. To determine the full extent of sex differences in birth defects in a population, we examined population‐based data from the Metropolitan Atlanta Congenital Defects Program (MACDP).

Methods

MACDP records were analyzed for 1968 through 1995. We determined the sex‐specific prevalence of all major birth defects, using the total number of live births by sex during these years as the denominator. For each specific defect, we calculated a relative risk with regard to sex on the basis of the ratio of prevalence among males to prevalence among females. Male–female relative risks were also determined for total major birth defects and for several broad categories of defects.

Results

The overall prevalence of major defects at birth was 3.9% among males and 2.8% among females. All but two of the major categories of birth defects (nervous system defects and endocrine system defects) had a higher prevalence among males. Defects of the sex organs were eight and one‐half times more prevalent among males and accounted for about half of the increased risk of birth defects among males relative to females. Urinary tract defects were 62% more prevalent among males, and gastrointestinal tract defects were 55% more prevalent among males. Among specific defect types, twofold or greater differences in prevalence by sex were common.

Conclusions

Our data indicate that sex differences in the prevalence of specific human birth defects are common, and male infants are at greater risk for birth defects than female infants. Several mechanisms have been proposed to account for these differences. Teratology 64:237–251, 2001. Published 2001 Wiley‐Liss, Inc.
Learning That Lasts a Lifetime: Teaching for Long‐Term Retention and Transfer
Authors: Halpern Diane F. , Hakel Milton D.
Published: August 2002

College faculty entrusted with the task of educating the next generation need to think far beyond the end of the semester and teach for a time in the distant future and for a test that they will not be giving.
Detection and quantification of microcystins from cyanobacteria strains isolated from reservoirs and ponds in Morocco
Authors: Oudra B. , Loudiki M. , Vasconcelos V. , Sabour B. , Sbiyyaa B. , Oufdou Kh. , Mezrioui N.
Published: August 2002

In Morocco, the occurrence of toxic cyanobacteria blooms is confirmed in some water bodies used for recreational and/or as drinking water reservoirs. According to WHO recommendations, the establishment of a monitoring program for microcystins is a necessity. This paper presents toxicological studies of 19 toxic cyanobacteria strains of Microcystis, Synechocystis, Pseudanabaena, and Oscillatoria. These strains were isolated from various water bodies including natural lakes, reservoirs, and ponds located in central regions of Morocco. The isolation, culture, and biomass production of these strains was made on Z8 or BG13 media under laboratory controlled conditions. The hepatotoxicity of cyanobacterial lyophilized material was confirmed by mouse bioassays. The amount of microcystins produced by each strain was determined by the enzyme‐linked immunosorbent assay (ELISA). The detection and identification of microcystin variants was performed by high performance liquid chromatography (HPLC) with photodiode array detection. Almost all strains showed medium to high toxicity, the estimated LD50 i.p mice bioassay ranged between 28 to 350 mg/kg body weight. The concentrations of microcystins varied between 2.16 to 944 μg/g and 26.8 to 1884 μg/g dry weight determined by ELISA and HPLC, respectively. The screening of bloom‐forming and microcystin producer cyanobacteria strains in these fresh water bodies leads us to propose the need for the establishment of a survey of cyanobacteria and a cyanotoxin‐monitoring program. © 2002 by Wiley Periodicals, Inc. Environ Toxicol 17: 32–39, 2002
Measurement of detection efficiency and response functions for an Si(Li) x‐ray spectrometer in the range 0.1–5 keV
Authors: Scholze F. , Procop M.
Published: August 2002

Efficiency and response functions were determined for a modern commercial energy‐dispersive x‐ray spectrometer in the photon energy range 0.1–5 keV using dispersed and undispersed synchrotron radiation. The spectrometer was equipped with an Si(Li) detector crystal, a thin‐film window and a digital pulse processor. Monochromatized synchrotron radiation from the PTB VUV radiometry beamline at the electron storage ring BESSY was used for the absolute determination of the detection efficiency with a typical relative uncertainty of 1–2% in the photon energy range 0.1–1.5 keV by direct comparison with calibrated photodiodes. At higher photon energies, the efficiency was found by comparison of the measured and calculated undispersed synchrotron radiation spectrum. The absolute intensity of the synchrotron radiation was known with a relative uncertainty of less than 1%. In the overlapping region, the results from the two independent experiments are in full agreement. The energy dependence of the measured efficiency can be explained only with a detector model assuming that there is no dead layer. A simple model for the effect of incomplete charge collection (ICC) was applied to describe the measured response functions. Consequences of the ICC such as broadening and shift of low‐energy peaks and redistribution of counts around 1.84 keV are explained with the model, in accordance with the experimental results. Copyright © 2001 John Wiley & Sons, Ltd.
Speciation of sub‐parts per billion levels of Cr(III) in waters by solid‐phase adsorption followed by thin‐layer x‐ray fluorescence spectrometry
Authors: Hettipathirana Terrance D.
Published: August 2002

A thin‐layer x‐ray fluorescence spectrometric (XRFS) method is described for the speciation of low‐parts per billion levels of Cr(III) in waters. The method is based on the adsorption of Cr(III) on to solid‐phase hydrous ferric hydroxide (HFO), and the applicability of the method is demonstrated using seawaters, a matrix widely regarded as difficult to analyse for contaminant elements. The Cr(III) fluorescence emission intensity from the solid phase vs its initial concentration in the solution phase, to a first approximation, can be described as a Langmuir isotherm, and is linearly proportional to Cr(III) concentrations up to ∼50 µg l−1. The method detection limit for Cr(III) in seawater, determined by energy‐dispersive (ED)‐XRFS and wavelength‐dispersive (WD)‐XRFS, is 0.10 and 0.88 µg l−1, respectively. The precision of the ED‐XRFS and WD‐XRFS analyses can generally vary between ∼5 and 10%. This relatively low precision can be attributed to the topography of the amorphous HFO impregnation in the solid phase. The error due to the presence of Cr(VI), as CrO42− or Cr2O72−, is within the experimental error, and the method is suitable for the determination of Cr(III) when it is the predominant Cr species present in the sample. Copyright © 2001 John Wiley & Sons, Ltd.
[PSI+] prion generation in yeast: characterization of the ‘strain’ difference
Authors: Kochneva‐Pervukhova Natalia V. , Chechenova Maria B. , Valouev Igor A. , Kushnirov Vitaly V. , Smirnov Vladimir N. , Ter‐Avanesyan Michael D.
Published: August 2002

The yeast cytoplasmically‐inherited nonsense suppressor [PSI+] determinant is presumed to be a manifestation of the aggregated prion‐like state of the Sup35 protein. Overexpression of the Sup35 protein induces generation of [PSI+] determinants with various suppressor efficiency and mitotic stabilities. Here, we demonstrate that the relative frequency of appearance of [PSI+] with different properties depends on the SUP35 allele used to induce their generation. The difference in properties of [PSI+] determinants was preserved after their transmission from one yeast strain to another. This difference correlated with variation in properties of the Sup35 protein. A novel type of prion instability was observed: some [PSI+] with weak suppressor efficiency could convert spontaneously into strong suppressor determinants. Copyright © 2001 John Wiley & Sons, Ltd.
Case Study: Formal Verification of a Computerized Railway Interlocking
Authors: Borälv Arne
Published: August 2002

We describe a case study in system-level verification of a computerized railway interlocking developed by ADtranz Spain, installed and put into test use at a subway station in Madrid. The formal modelling and analysis was carried out by personell at ADtranz Sweden using a tool for automatic formal modelling of the interlocking system and the commerical verification software NP-Tools, which is based on Stålmarck's patented proof procedure.

The case study took about one man week in total, of which most of the time was spent modelling safety requirements. The analysis discovered an error that had passed the traditional verification phase.

The actual analysis time, disproving the safety requirements by supplying a countermodel, was done in a matter of seconds. The corrected software could be proved to fulfil the safety requirements in the same amount of time.

This case study is one of many carried out by ADtranz during 1995-98 in the process in which they have replaced the traditional techniques used for system level verification of safety with formal techniques. We give an overview of the formal methods and tools used which today are integrated in the development environment at ADtranz.
Lymph Node Recovery from Colorectal Tumor Specimens:Recommendation for a Minimum Number of Lymph Nodes to be Examined
Authors: Cianchi Fabio , Palomba Annarita , Boddi Vieri , Messerini Luca , Pucciani Filippo , Perigli Giuliano , Bechi Paolo , Cortesini Camillo
Published: August 2002

Lymph node involvement is the mostimportant prognostic factor for patients who have undergone radicalsurgery for colorectal carcinoma. An accurate examination of thesurgical specimens is mandatory for the correct assessment of the lymphnode status of the tumor. The risk of understaging is particularly highfor patients with tumors classified as Dukes B (TNM stage II). The aimof this study was to determine if a specified minimum number of lymphnodes examined per surgical specimen could have any effect on theprognosis of patients who had undergone radical surgery for Dukes Bcolorectal cancer. Between 1988 and 1995 a total of 140 patientsunderwent radical resection of Dukes B colorectal cancer by the samesurgeon (C.C.). The relation between clinicopathologic variables andsurvival was estimated using the Kaplan‐Meier method. The Coxproportional hazard regression model was used to identify the variablesthat can independently influence survival. A median of 12 lymph nodes(range 3–38) was examined per tumor specimen. The 5‐year survival rateof Dukes B patients who had had eight or fewer lymph nodes examinedafter surgery was 54.9%, whereas the survival rate for those who hadhad nine or more lymph nodes examined was 79.9% (p < 0.001). Cox regression analysis identified the number of lymph nodes asthe only independent prognostic factor (p = 0.01).Seventy patients with one to four metastatic lymph nodes (Dukes Cpatients) who had been operated on during the same period were includedin the survival analysis for comparison. The 5‐year survival rate ofthe Dukes B patients with eight or fewer lymph nodes examined wassimilar to that of the 70 Dukes C patients (54.9% and 51.8%,respectively). Examination of eight or fewer lymph nodes in Dukes Bcolorectal patients may be considered a high risk factor for missingpositive lymph nodes in the surgical specimens. Our results suggestthat harvesting and examining a minimum of nine lymph nodes persurgical specimen may be sufficient for reliable staging of lymphnode‐negative tumors.
Gastrointestinal Anastomosis with the Nickel‐Titanium Double Ring
Authors: Nudelman Israel L. , Fuko Vladimir V. , Morgenstern Sara , Giler Shamai , Lelcuk Shlomo
Published: August 2002

We used a dog model to test the safety and effectiveness of sutureless gastrointestinal anastomoses (n= 23) (end‐to‐end, end‐to‐side, or side‐to‐side) with the nickel‐titanium double ring with temperature‐dependent shape memory. Results were compared to conventional hand‐sutured anastomoses (n= 5). Examination performed after 2 weeks' follow‐up showed no leaks and no difference in return of bowel function between the experimental groups and the control group. Microscopic studies showed a complete epithelial lining and perfectly functioning anastomoses. We conclude that the nickel‐titanium double‐ring device may have an important place in the armamentarium of the gastrointestinal surgeon.
Familial Papillary Thyroid Carcinoma: Genetics, Criteria for Diagnosis, Clinical Features, and Surgical Treatment
Authors: Musholt Thomas J. , Musholt Petra B. , Petrich Thorsten , Oetting Gundula , Knapp Wolfram H. , Klempnauer Juergen
Published: August 2002

Hereditable predisposition to papillary thyroid carcinoma (PTC) and multinodular goiter (MNG) without evidence of an association with other malignancies as a distinct entity was recognized only recently. A meta‐review of the literature on familial PTC (FPTC) was undertaken, and characteristics of families with frequent occurrence of PTC or MNG (or both) were summarized. A database on thyroid cancer patients maintained in our institution was searched for potential FPTC families. Clinical examinations were performed in 6 of 12 Hannover kindreds identified, and blood samples of all family members were collected for genetic analyses. Clinical presentations and histopathologic features of the FPTC cases were compiled. Based on the FPTC meta‐review and own experience, predictive criteria to identify families at risk were developed: Exclusion criteria were previous radiation exposure and coincidence with neoplasia syndromes. Primary criteria for susceptibility to FPTC are (1) PTC in two or more first‐degree relatives and (2) MNG in at least three first‐ or second‐degree relatives of a PTC patient. Secondary criteria are diagnosis in a patient younger than 33 years, multifocal or bilateral PTC, organ‐exceeding tumor growth (T4), metastasis (N1, M1), and familial accumulation of adolescent‐onset thyroid disease. A hereditary predisposition to PTC is considered if both primary criteria or one primary criterion plus three secondary criteria are present. Family history‐taking is recommended for all PTC patients to identify FPTC kindreds at risk. Blood relatives of FPTC index patients who harbor MNG should undergo thorough and regular clinical screening. Suspicious lesions should prompt early surgical intervention.
Determining Which Patients Require Evaluation for Blunt Cardiac Injury following Blunt Chest Trauma
Authors: Nagy Kimberly K. , Krosner Seth M. , Roberts Roxanne R. , Joseph Kimberly T. , Smith Robert F. , Barrett John
Published: August 2002

The objective of this study was to determine prospectively which risk factors require cardiac monitoring for blunt cardiac injury (BCI) following blunt chest trauma. All patients who sustained blunt chest trauma had an electrocardiogram (ECG) on admission to our urban level I trauma center. Those with ST segment changes, dysrhythmias, hemodynamic instability, history of cardiac disease, age >55 years, or a need for general anesthesia within 24 hours (group 1) were admitted to the intensive care unit (ICU) for 24 hours where they were subjected to serial ECGs, creatinine phosphokinase (CPK) assays, and echocardiography (ECHO). Those with only mechanism for BCI, i.e., none of the above risk factors (group 2), were admitted to a nonmonitored bed and had a follow‐up ECG 24 hours later. A series of 315 patients were admitted with blunt chest trauma during a 17‐month period; 144 patients were in group 1 and 171 in group 2. Overall, 22 patients were diagnosed as BCI (+BCI), defined as evolving ST segment changes, dysrhythmias, a CPK‐MB index of >2.5, or hemodynamic instability. Of the 18 +BCI patients in group 1, all were symptomatic (i.e., none was included solely for a cardiac history, age, or need for general anesthesia). Six of these patients required treatment for dysrhythmias, hypotension, or pulmonary edema; one of whom died. Four patients with +BCI were in group 2 and had ECG changes at 24 hours; none of these four had any sequelae from their +BCI. None of the ECHOs demonstrated abnormal wall motion. Patients who sustain blunt chest trauma with a normal ECG, normal blood pressure, and no dysrhythmias on admission require no further intervention for BCI. Patients with ST segment changes, dysrhythmias, or hypotension following blunt chest trauma should be monitored for 24 hours, as this subgroup occasionally requires further treatment for complications of BCI. ECHO adds nothing as a screening test.
Congenital Short Colon
Authors: Wakhlu Avtar Kishan , Wakhlu Ashish , Pandey Ashutosh , Agarwal Rajiv , Tandon R.K. , Kureel S. N.
Published: August 2002

Congenital short colon (CSC) is a condition in which the colon is replaced, wholly or partially, by a dilated pouch together with anorectal malformation and a colourinary fistula. Most of the reported series have been from northern India where this malformation is frequent. This paper details the management of 108 patients with CSC over a period of 23 years. The patients were classified into two types: (1) Partial short colon, where a segment of normal colon is present between the ileum and the sac. These patients could be treated by excision of the pouch and pull‐through of the segment of normal colon during either single‐ or two‐stage surgery. (2) Complete short colon, where the ileum opened directly into the sac, and formation of a tube from this sac (coloplasty) was required in one or more stages to provide a length of normally functioning colon. Review of the results showed staged management to be superior. The follow‐up has ranged between 3 and 7 years, with satisfactory long‐term results in both groups of patients. We have evolved a protocol for the management of CSC that has improved the prognosis and quality of life of these patients.
Medical Treatment of Metastasizing Carcinoid Tumors
Authors: Arnold R.
Published: August 2002

Long‐acting somatostatin analogs, such as octreotide, comprise the therapeutic modality of choice for the symptomatic relief of flush and diarrhea in patients with carcinoid syndrome. The sequelae of gastric acid hypersecretion in patients with gastrin‐producing duodenal carcinoids (gastrinoma) are perfectly controlled by proton pump inhibitors. Antiproliferative medical strategies to control the growth of metastatic carcinoid tumors include long‐acting somatostatin analogs, interferon alpha, and the combination of the two. However, the success rate is less than 50%, and it is questionable whether true tumor regression can be expected. Controlled prospective studies are mandatory to address the question whether interferon or somatostatin analogs or the combination of the two should be used as first‐line medical strategies and if hepatic artery embolization in patients with liver metastases should be performed before beginning medical therapy. Chemotherapy, including etoposide and cisplatin, has been shown to be effective only for purely differentiated neuroendocrine carcinomas and not for slowly growing carcinoids.
Two‐Dimensional Proton Magnetic Resonance Spectroscopy for Tissue Characterization of Thyroid Neoplasms
Authors: Mackinnon Wanda B. , Delbridge Leigh , Russell Peter , Lean Cynthia L. , May George L. , Doran Sinead , Dowd Susan , Mountford Carolyn E.
Published: August 2002

We have previously demonstrated that one dimensional (1D) proton (1H) magnetic resonance spectroscopy (MRS) can distinguish normal thyroid tissue from thyroid carcinoma using a spectral ratio of peak intensity at 1.7 ppm/0.9 ppm. Two dimensional (2D) 1H‐MRS allows identification of specific molecules that have overlapping peaks in the 1D‐MR spectrum. Specimens from 93 consecutive thyroid nodules were examined using 2D 1H‐MRS on a Bruker AM‐360 wide‐bore spectrometer. There was a progressive increase in lipid cross peaks assigned to di‐/triglycerides when comparing colloid/hyperplastic nodules to follicular adenoma, and adenoma to carcinoma. A specific cross peak attributable to cholesterol/cholesteryl esters was commonly seen in carcinomas. In contrast, two unassigned cross peaks unique to the thyroid were more prevalent in benign lesions. There was an overall increase in cross peaks attributable to cell surface fucosylation in carcinoma when compared to benign lesions, although the fucose spectral pattern was not specific for cancer. On this basis, a spectral ratio of peak intensity at 2.05 ppm/0.9 ppm more clearly distinguished benign follicular adenoma from carcinoma. 2D 1H‐MRS thus identifies chemical changes that allow more specific tissue characterization of thyroid neoplasms.
Intraabdominal Pressure and Gastric Intramucosal pH: Is There an Association?
Authors: Sugrue M. , Jones F. , Lee Anna , Buist M.D. , Deane S. , Bauman A. , Hillman K.
Published: August 2002

This study evaluated the potential association between increased intraabdominal pressure (IAP) and abnormally low gastric intramucosal pH (pHi) (≤ 7.32) in postoperative patients and assessed its effect on patient outcome. Altogether 73 patients undergoing major abdominal surgery over a 9‐month period were studied prospectively. All underwent gastric tonometry and intravesical IAP measurements three time daily. An IAP of ≥ 20 mmHg and a pHi of ≤ 7.32 were considered abnormal. The development of the following complications were also documented: hypotension [mean aortic pressure (MAP) < 80 mmHg], abdominal sepsis, renal impairment, and death. The median APACHE II score was 16 (range 5–34). Twenty‐two patients had upper gastrointestinal (GI) surgery, 27 lower GI surgery, and 24 aortic surgery; 44 of these patients underwent emergency surgery. Abnormal pHi (≤ 7.32) occurred in 36 patients while on the intensive care unit. Compared to patients with normal pHi, abnormal pHi patients were 11.3 times (3.2–43.5) [odds ratio ± 95% CI] more likely to have an increased IAP. Abnormal pHi was significantly associated with hypotension (χ2 = 6.8;p= 0.009), sepsis (χ2= 3.7;p= 0.06), renal impairment (χ2= 28.3;p= 0.0000001), relaparotomy (χ2= 4.1;p= 0.04), and death (χ2= 9.7;p= 0.002). This study demonstrated a significant clinical association between increased IAP and abnormal pHi. An abnormally low pHi was associated with poor outcome.
Five Years as a Flying Surgeon in Zimbabwe
Authors: Cotton Michael H.
Published: August 2002

Surgical services in the developing world are often based on a Western model where the patient has to seek out the surgeon. A reverse policy was instituted to overcome severe logistical problems. Funding was obtained for air flights to 10 distant rural hospitals and a program of visits advertised in advance. Patients were selected by the resident doctor and seen either as in‐ or outpatients. A list was drawn up and patients were operated on that day and if necessary the following day when earlier postoperative cases were reviewed. More than 500 operations were performed of varying complexity, and complications were reported in fewer than 10. A scheme where the surgeon visits the rural patient in his or her home area is cost‐effective, popular, and beneficial to the hospital staff. It obviates the need for distant referral where there may be language difficulties and where visits from relatives are precluded. It also reduces the workload of overstretched referral centers. It provides the means to teach the local resident doctor rudiments of surgical practice, and it provides regular contact between the outstation and the referral center.
Hemodilution in Clinical Surgery: State of the Art 1996
Authors: Kreimeier U. , Messmer K.
Published: August 2002

Acute normovolemic hemodilution entails removal of blood from a patient either immediately before or shortly after induction of anesthesia and simultaneous replacement with cell‐free fluid. Nowadays, because of their predictable volume effects, the synthetic colloids (6% dextran 60/70, 6% hydroxyethyl starch 200,000) are preferred as volume substitutes; albumin should be avoided because of its high cost. Hemodilution has experienced a renaissance in recent years, mainly due to the evolving discussion of legal aspects, immunologic changes, viral infections, and a potentially higher cancer recurrence rate associated with the transfusion of homologous blood. Hemodilution should be considered for elective surgical patients free of contraindications and presenting with an initial hemoglobin concentration ≥ 12 g/dl and an anticipated blood loss of ≥ 1500 ml. The efficacy of this method (judged by the need to give homologous blood transfusion) depends on the preoperative (initial) hematocrit, the target hematocrit (to which hemodilution is performed), and the preset intra‐ and postoperative transfusion trigger. In the past, data from clinical trials showed that in healthy subjects a target hematocrit of 20% to 25% (hemoglobin 7.0–8.0 g/dl) is feasible and safe for the patient. The lower the target hematocrit accepted, the more extensive is the monitoring required: Intraoperative target hemoglobin concentrations of 5.0 g/dl and less have been tolerated by surgical patients without adverse effects. The safety and efficacy of acute normovolemic hemodilution in terms of reducing homologous blood transfusion requirements has been demonstrated in various clinical studies. Hemodilution therefore is regarded an integral part of programs aimed at reducing the need for homologous blood and can thus be successfully combined with preoperative autologous blood deposition, intraoperative blood salvage, and carefully adjusted surgical techniques. Hemodilution is feasible and relatively cost‐effective, and it minimizes adverse effects associated with transfusion of homologous blood, particularly transmission of viral diseases, immunosuppression, and infectious complications.
Use of Pentastarch Solution in the Treatment of Patients with Hemorrhagic Hypovolemia: Randomized Phase II Study in the Emergency Room
Authors: Younes Riad N. , Yin Ko C. , Amino Claudio J. , Itinoshe Mario , Rocha e Silva Mauricio , Birolini Dario
Published: August 2002

This study evaluates the hemodynamic effects of the administration of 10% pentastarch solution (PS) during the initial treatment of hypovolemia in trauma patients. This prospective randomized phase II study included trauma patients admitted to the emergency room with hemorrhagic hypovolemia: systolic blood pressure (SBP) < 90 mmHg. Upon admission, the patients were randomized to receive 10% PS (n= 12) or isotonic 0.9% NaCl solution (IS) (n= 11), infused intravenously in 250‐ml boluses, repeated until SBP > 100 mmHg. Blood pressure, infused volumes necessary to maintain SBP, and overall survival rates were determined and compared between groups. SBP increased significantly following either IS (from 64.4 ± 9.2 mmHg to 111.1 ± 6.3 mmHg), or PS (from 63.7 ± 10.6 mmHg to 108.1 ± 9.8 mmHg) when compared to admission values (p < 0.05). Endovenous volumes infused were greater (p= 0.001) in IS patients (1420 ± 298 ml) than in PS patients (356 ± 64 ml). No blood was transfused into PS patients, compared to 370 ± 140 ml of red blood cells transfused into IS patients (p= 0.015). Mortality rates were similar in the two groups (p= 0.725). We concluded that PS is a safe, efficient method for inducing hemodynamic recovery of hypovolemic trauma patients, with a clear reduction in the intravenous volumes required for acute resuscitation.
Antibiotic‐Resistant Gram‐Positive Cocci: Implications for Surgical Practice
Authors: Barie Philip S.
Published: August 2002

Gram‐positive infections are causing more serious infections than ever before in surgical patients, who are increasingly aged, ill, and debilitated. Invasive procedures disrupt natural barriers to bacterial invasion, and indwelling catheters may act as conduits for infection. The use of broad‐spectrum antibiotics selects for the emergence of resistant pathogens. Potential sites of nosocomial gram‐positive infections include the urinary tract, surgical site (including prosthetic devices), intravascular loci, lung and pleural space, facial sinuses, and peritoneal cavity. Responsible organisms include species from the genera Enterococcus andStaphylococcus. Methicillin‐resistant strains ofStaphylococcus aureus (MRSA) and Staphylococcus epidermidis (MRSE) emerged during the 1970s, leading to a marked increase in the use of vancomycin as the treatment of choice. Vancomycin use, in turn, has been implicated (along with widespread cephalosporin use) in the emergence of vancomycin‐resistant enterococci (VRE) during the 1990s. Of great concern is the likely emergence of vancomycin‐resistant staphylococci, which would constitute a public health emergency. Vancomycin remains the treatment of choice for infections caused by MRSA/MRSE, but rampant inappropriate use (e.g., prophylaxis in non‐penicillin‐allergic patients, treatment of methicillin‐sensitive strains) must be curtailed. Chloramphenicol is increasingly the treatment of choice for serious VRE infections. Infection control policy must also minimize the possibility of transmission. All infected or colonized patients should be isolated and all environmental surfaces considered contaminated. Disposable gloves are mandatory for all patient contact, even incidental contact, and must be disposed of after each patient encounter. Hand‐washing (the single most effective infection control measure) is mandatory after glove disposal. Gowns should be worn for direct contact with infected patients and masks used when aerosolization or splashing of secretions is likely.
Outcome after Elective Infrarenal Aortic Aneurysm Surgery
Authors: Cohen Jonathan D. , Singer Pierre , Grunberg Gloria , Grozovski Elad , Sulkes Jaqueline , Zelikovski Avigdor
Published: August 2002

We conducted a prospective case series study to investigate the causes of and factors influencing morbidity and mortality in 102 consecutive patients after elective infrarenal abdominal aneurysm (AAA) surgery between 1992 and 1995. Preoperative factors (demographics, risk factor indexes, electrocardiographic findings, ejection fraction, and stress imaging scans were indicated) and intraoperative factors (duration of surgery, size of aneurysm, complications, units of blood transfused, and additional procedures performed) were recorded. Patients were admitted to the intensive care unit (ICU) for at least 24 hours and followed for 30 days postoperatively. The mortality rate was 4.9%, due in all cases to multiorgan dysfunction syndrome (MODS). Death was preceded by colon ischemia (two patients), intraabdominal bleeding (two patients), or sepsis (one patient). Only the preoperative blood urea nitrogen correlated with mortality (p= 0.042). Complications occurred in 59% of patients in the ICU and involved the cardiovascular system in 83% of them (heart rate > 90 bpm in 49%). On multivariate analysis, only duration of surgery was associated with ICU complications (p= 0.018). No complication resulted in mortality. Ward complications occurred in 13%, and 5% of these patients required readmission to the ICU. Although cardiac complications are considered the major cause of mortality after infrarenal AAA surgery, all five deaths in the present series were due to MODS. Preoperative screening should be more selective, and intraoperative and postoperative care should be stressed.
Pouchitis: Risk Factors, Etiology, and Treatment
Authors: Nicholls R. John , Banerjee Anjan K.
Published: August 2002

A Medline literature review of pouchitis has been conducted, and relevant information from this search and the authors’ own experience has been used to produce an overview on pouchitis at the current time. Particular attention is given to etiology, pathophysiology, and clinical management.
Evaluation of Surgical Treatment of Renal Hyperparathyroidism by Measuring Intact Parathormone Blood Levels on First Postoperative Day
Authors: Kinnaert Paul , Tielemans Christian , Dhaene Michel , Decoster‐Gervy Christine
Published: August 2002

Intact parathormone (inPTH) has a short half‐life. Its blood level on the first day after total parathyroidectomy and subcutaneous parathyroid implantation (PTX + G) should therefore allow an early diagnosis of missed residual parathyroid tissue. We tested this hypothesis in 72 uremic patients who were followed for 6 to 110 months after operation. Nine were reoperated for recurrence of the disease. Graft removal was successful in four patients who had post‐PTX inPTH levels of 16 pg/ml or lower. In five patients, an overlooked parathyroid gland had to be resected. All of them had elevated post‐PTX inPTH blood levels ranging from 72 to 791 pg/ml (upper normal limit 55 pg/ml). Three of these patients had presented with hypocalcemia after PTX. We conclude that the inPTH blood concentration on the first day after PTX allows more precise evaluation of the efficacy of the surgical procedure than the postoperative evolution of blood calcium levels. It is also useful for localizing the source of excessive PTH secretion (graft or overlooked gland) when the disease recurs.
Starvation Injury after Gastric Reduction for Obesity
Authors: Mason Edward E.
Published: August 2002

Gastric reduction operations are designed to control body weight by establishing a small, meal‐size juxtaesophageal, gastric pouch that empties into the jejunum (gastric bypass) or the larger portion of the stomach (gastroplasty). If the outlet of the pouch is too small, a patient may be limited to ingesting clear liquids. Vomiting then occurs if heavier liquids or normal foods are taken. An occasional patient has difficulty eating properly and vomits even though the pouch volume and outlet are of optimum size. For a patient who reports vomiting, a distinction must be made between episodic improper eating and uncontrolled starvation. Three types of starvation injury are described: (1) sudden death from protein malnutrition; (2) refeeding syndrome; and (3) Wernicke‐Korsakoff syndrome. The mechanisms of the development, manifestations, prevention, and treatment of these complications are explained. Surgeons who treat severe obesity should be aware of these complications and be prepared to manage patients who have uncontrolled vomiting so that such complications either do not develop or are recognized and treated as early as possible before serious and irreversible injury occurs.
Pancreatic Solid‐cystic‐papillary Tumor: Clinicopathologic Features in Eight Patients from Hong Kong and Review of the Literature
Authors: Lam King Y. , Lo Chung Y. , Fan Sheung T.
Published: August 2002

Solid‐cystic‐papillary tumors (SCPTs) of the pancreas are rare. The clinicopathologic features and pathogenesis of these tumors have attracted a number of investigations, but the results remain unclear. We investigated the clinicopathologic data, immunohistochemical expression of the pan‐endocrine markers, hormones, steroid receptors, and p53 overexpression in pancreatic SCPTs from eight Chinese patients (seven women, one man) collected over a 24‐year period. They accounted for 2.5% of the primary pancreatic tumors. The tumors were seen in young women (mean age 27 years). They were large (mean size of resected tumor was 8.4 cm), benign, had solid and cystic areas, and were evenly distributed in the pancreas. The main differential diagnosis was pancreatic endocrine tumor. The tumors were negative for pan‐endocrine markers, hormones, estrogen receptor, progesterone receptor, and p53. To date, 452 pancreatic SCPTs have been documented in the English literature. They occurred in patients of different ethnic groups, particularly in non‐Caucasians. The tumors were frequently noted in young females. Uncommon cases of malignant pancreatic SCPTs were often found in older men and had indolent behavior. It was concluded that pancreatic SCPTs have distinct clinicopathologic characteristics. The present observations, together with a review of the literature suggests that overexpression of p53 or estrogen receptor is not important in the pathogenesis of pancreatic SCPTs.
Pulmonary Arteriovenous Fistula: Presentation, Diagnosis, and Treatment
Authors: Pick Adrian , Deschamps Claude , Stanson Anthony W.
Published: August 2002

Pulmonary arteriovenous fistulas (PAVFs) are rare vascular malformations of the lung. There is a strong association with Rendu‐Osler‐Weber disease. Although most patients are asymptomatic, PAVFs can cause dyspnea from a right‐to‐left shunt. They can also bleed and result in hemoptysis and hemothorax. Because of paradoxical emboli, various central nervous system complications have been described including stroke, and brain abscess. Currently, spiral computed tomography offers the most practical method for establishing the presence of PAVFs. Most patients should be treated. Therapeutic options include angiographic embolization with metal coils or balloon occlusion and surgical excision. Angiographic treatment has become the mainstay of therapy for most patients during the last decade. It is less invasive and can be repeated easily. Surgery, which usually consists of a conservative lung resection, is associated with low morbidity and a low recurrence rate. Both therapeutic approaches are discussed. The Mayo Clinic surgical experience of the last 20 years for PAVFs is presented.