bluuebunny/crossref_metadata_2025 huggingface dataset:
Two‐sample scale tests for comparison of metabolic rates for styrene in previously exposed and unexposed groups
Authors: Chen Chu‐Chih , Wu Kuen‐Yuh , Balakrishnan N.
Published: January 2004

Statistical analysis procedure in two‐sample treatment difference, as well as alternative hypothesis, may play a central role in statistical inference, especially in small sample size case. In this paper, simple non‐parametric two‐sample permutation tests for scale difference based on the Hodges–Lehmann estimator are reformulated, and are applied to a study examining whether previous styrene exposure increases (thus a one‐sided alternative hypothesis rather than a two‐sided one) the human liver's metabolic ability to convert styrene into styrene oxide, in which a three‐compartment physiologically based pharmacokinetic (PBPK) model was used to compare the estimated metabolic constant κamong the previously exposed and unexposed groups. Contrary to the previous conclusion, the proposed tests for scale difference identified from a mixed‐effects model showed a significant result. Copyright © 2004 John Wiley & Sons, Ltd.
Electronic monitoring of variation in drug intakes can reduce bias and improve precision in pharmacokinetic/pharmacodynamic population studies
Authors: Vrijens Bernard , Goetghebeur Els
Published: January 2004

Population pharmacokinetic (PK) and pharmacodynamic (PD) studies evaluate drug concentration profiles and pharmacological effects over time when standard drug dosage regimens are assigned. They constitute a scientific basis for the determination of the optimal dosage of a new drug. Population PK/PD analyses can be performed on relatively few measures per patient enabling the study of a sizable sample of patients who take the drug over a possibly long period of time. We expose the problem of bias in PK/PD estimators in the presence of partial compliance with assigned treatment as it occurs in practice. We propose to solve this by recording accurate data on a number of previous dose timings and using timing‐explicit hierarchical non‐linear models for analysis. In practice, we rely on electronic measures of an ambulatory patient's drug dosing histories. Especially for non‐linear PD estimation, we found that not only bias can be reduced, but higher precision can also be retrieved from the same number of data points when irregular drug intake times occur in well‐controlled studies. We apply methods proposed by Mentré et al. to investigate the information matrix for hierarchical non‐linear models. This confirms that a substantial gain in precision can be expected due to irregular drug intakes. Intuitively, this is explained by the fact that regular takers experience a relatively small range of concentrations, which makes it hard to estimate any deviation from linearity in the effect model. We conclude that estimators of PK/PD parameters can benefit greatly from information that enters through greater variation in the drug exposure process. Copyright © 2004 John Wiley & Sons, Ltd.
Binary latent variable modelling and its applicationin the study of air pollution in Hong Kong
Authors: Hu Z. G. , Wong C. M. , Thach T. Q. , Lam T. H. , Hedley A. J.
Published: January 2004

A binary latent variable is constructed to account for the correlation between multiple binary outcomes and is treated as a dependent variable in modelling for covariate effects. This modelling method is similar to the structural equation modelling. Three models are considered: (1) all covariates affecting the binary latent variable directly; (2) some covariates affecting the binary latent variable while other affecting the manifestation of the binary outcomes; and (3) no covariates are included. Gibbs sampling, a special case of the Markov Chain Monte Carlo method, is used to estimate the parameters in the models. Simulation studies show that this method is valid and reliable in estimating covariate effects. But Model (1) fitted the data best with lowest value in the deviance information criteria. The method is illustrated by applying it to the data analysis of an environmental air pollution study. The results show that air pollution (i.e. the most versus the least polluted district) (odds ratio 1.20; 95% confidence interval 0.97–1.49; p=0.102), smoking (relative to not smoking) (2.75; 2.21–3.41; p < 0.001) and mosquito coil use (relative to non‐use) (1.27; 0.99–1.62; p=0.058) had an impact on the respiratory health of male adults in Hong Kong. Copyright © 2004 John Wiley & Sons, Ltd.
The WebDAV property design
Authors: Whitehead E. James , Goland Yaron Y.
Published: January 2004

This paper provides a detailed description of the general design space for metadata storage capabilities. The design space considers issues of metadata identification, typing and representation, dynamic behavior, predefined and user‐defined metadata, schema discovery/update, operations, API packaging/marshalling, searching, and versioning. The design space is used to structure a retrospective analysis of the three major alternative metadata designs considered during the design of the WebDAV distributed authoring protocol. Deployment experience with WebDAV properties is also discussed, with the most successful use occurring in custom client/server pairs and in protocol extensions. Copyright © 2004 John Wiley & Sons, Ltd.
Understanding Web server configuration issues
Authors: Arlitt Martin , Williamson Carey
Published: January 2004

This paper proposes a methodological approach to the evaluation of Web server performance in a simple local area network test environment. The paper examines how different system and application configuration parameters can, over a range of workloads, impact the performance of a Web server. Our approach relies on relatively fine‐grain reporting of performance data for a broad set of system‐level metrics. Graphical visualization of these performance indices helps to identify the primary system bottleneck in each configuration studied.

The Apache Web server is used as a case study to demonstrate the methodology. Our experiments quantify the performance implications of several configuration decisions common to any Web server implementation, and also serve to illustrate several performance anomalies specific to the Apache Web server (if misconfigured). Copyright © 2004 John Wiley & Sons, Ltd.
Exploring students' responses to conceptual questions when engaged with planned writing experiences: A study with year 10 science students
Authors: Hand Brian , Hohenshell Liesl , Prain Vaughan
Published: January 2004

Whereas there has been strong advocacy of the value of writing for learning in science, the role of student planning in this approach and the relationships between planning, writing, and learning have been underresearched. Our mixed method study aimed to address this issue by seeking to identify quantitative differences in learning outcomes between two groups of students exposed to varying degrees of planning activities in writing‐to‐learn experiences. We also identified differences in learning outcomes between a group of students with two writing experiences and a group with one writing experience. Results indicate that students with planned writing activities did not score significantly better on conceptual questions as a group than students who had delayed planning experiences. Students with two writing experiences as opposed to one also scored significantly better as a group on answering conceptual questions both immediately after the writing experience and on a test 8 weeks after the unit. The difference in writing treatment initially significantly affected males compared with females but this effect disappeared with further opportunities to write. Students' comments provide support for using nontraditional writing tasks as a means to assist learning, particularly when the focus is on an audience different from the teacher. In reporting on different learning outcomes for the two groups, we consider various implications including identification of some key conditions for student writing to serve learning. © 2004 Wiley Periodicals, Inc. J Res Sci Teach 41: 186–210, 2004
Role of the microcomputer‐based laboratory display in supporting the construction of new understandings in thermal physics
Authors: Russell David W. , Lucas Keith B. , McRobbie Campbell J.
Published: January 2004

Teachers' failure to use the microcomputer‐based laboratory (MBL) more widely may be a result of not recognizing its capacity to transform laboratory activities. This research aimed to increase understanding of how MBL activities designed to be consistent with a constructivist theory of learning support or constrain student construction of understanding. The first author conducted the research with his Year 11 physics class of 15 students. Dyads addressed 10 tasks in thermal physics using a predict–observe–explain format. Data sources included video and audio recordings of students and teacher during four 70‐minute sessions, students' computer data and written notes, semistructured student interviews, and the teacher's journal. Analysis of students' discourse identified many instances in which students' initial understandings of thermal physics were mediated in multiple ways by the screen display. The findings are presented as eight assertions. Recommendations are made for developing pedagogical strategies incorporating MBL activities that will likely catalyze student construction of understanding. © 2004 Wiley Periodicals, Inc. J Res Sci Teach 41: 165–185, 2004
Fostering radical conceptual change through dual‐situated learning model
Authors: She Hsiao‐Ching
Published: January 2004

This article examines how the Dual‐Situated Learning Model (DSLM) facilitates a radical change of concepts that involve the understanding of matter, process, and hierarchical attributes. The DSLM requires knowledge of students' prior beliefs of science concepts and the nature of these concepts. In addition, DSLM also serves two functions: it creates dissonance with students' prior knowledge by challenging their epistemological and ontological beliefs about science concepts, and it provides essential mental sets for students to reconstruct a more scientific view of the concepts. In this study, the concept “heat transfer: heat conduction and convection,” which requires an understanding of matter, process, and hierarchical attributes, was chosen to examine how DSLM can facilitate radical conceptual change among students. Results show that DSLM has great potential to foster a radical conceptual change process in learning heat transfer. Radical conceptual change can definitely be achieved and does not necessarily involve a slow or gradual process. © 2004 Wiley Periodicals, Inc. J Res Sci Teach 41: 142–164, 2004
Crossing cultural borders into science teaching: Early life experiences, racial and ethnic identities, and beliefs about diversity
Authors: Brand Brenda R. , Glasson George E.
Published: January 2004

The purpose of this ethnographic study was to explore the development of belief systems as related to racial and ethnic identities of preservice teachers as they crossed cultural borders into science teaching. Data were collected throughout a yearlong teacher preparation program to learn how early life experiences and racial and ethnic identities of preservice teachers influenced both their beliefs about diversity in science classrooms and science teaching pedagogy. Case studies of three preservice teachers from diverse racial and ethnic background are presented: Asian American, African American, and Rural Appalachian. Using Bank's ethnicity typology, findings suggest that racial and ethnic identity, developed in early life experiences of preservice teachers, provided clarity on the rigidity of their beliefs about diversity and how they view science teaching. By learning about the border crossing experiences of preservice teachers in relation to their beliefs about diversity as related to racial and ethnic identities, the researchers hoped to provide insight on preparing preservice teachers for the challenges of working in diverse classrooms. © 2004 Wiley Periodicals, Inc. J Res Sci Teach 41: 119–141, 2004
Resection of Hilar Cholangiocarcinomas: Pivotal Prognostic Factors and Impact of Tumor Sclerosis
Authors: Puhalla Harald , Gruenberger Thomas , Pokorny Herwig , Soliman Thomas , Wrba Fritz , Sponer Ulrike , Winkler Thomas , Ploner Meinhard , Raderer Markus , Steininger Rudolf , Mühlbacher Ferdinand , Laengle Friedrich
Published: January 2004

The well‐known poor prognosis of proximal bile duct cancer is due to its unfortunate anatomical location and its late diagnosis. Successful tumor resection, which is considered to be optimal treatment, depends on many factors. Eighty‐eight patients suffering from proximal bile duct cancer underwent surgical exploration at our institution between 1977 and 1998. In 37 patients the tumor was resectable; in the remaining 51 patients exploratory laparotomy or a palliative operation was performed. The median survival after tumor resection was 18.6 months, but median survival after a palliative procedure or an exploratory laparotomy was only 3.4 months (p < 0.001). A curative R0 resection was possible in 11 patients, an R1 resection was performed in 22 patients, and 4 patients had an R2 resection. The median survival rate after R0 resection was 83.6 months, 12.3 months after R1 resection, and 2.7 months after R2 resection (p < 0.001). Survival after resection in patients with negative lymph nodes (n = 30) was significantly longer than in those with positive lymph nodes (n = 7) (p = 0.022). Grade of tumor sclerosis tended to have an influence on resectability rate (p = 0.076). The pattern of tumor growth was without statistical influence. Multivariate analysis revealed resection (p < 0.001) as the only significant prognostic marker for patient survival. Radical resection is the only therapy that provides a chance for long‐term survival, with sclerosis of the cancer tending to have an influence on univariate analysis.
Role of Somatostatin in the Prevention of Pancreatic Stump‐related Morbidity following Elective Pancreaticoduodenectomy in High‐risk Patients and Elimination of Surgeon‐related Factors: Prospective, Randomized, Controlled Trial
Authors: Shan Yan‐Shen , Sy Edgar D. , Lin Pin‐Wen
Published: January 2004

A prospective, randomized, controlled trial was performed to determine the efficacy of somatostatin in the prevention of pancreatic stump‐related complications with elimination of surgeon‐related factors in high‐risk patients undergoing panceaticoduodenectomy. From August 1997 to December 2000, 54 patients, 28 men and 26 women, with age ranged from 32 to 89 years, were randomly assigned to somatostatin group (n = 27) or placebo group (n = 27). Ninety‐four percent of the patients had pancreatic and periampullary lesions; 6% had secondary lesion involving the duodenum such as local recurrent colon carcinoma and renal cell carcinoma. These patients received either standard pancreaticoduodenectomy or pylorus‐preserving pancreaticoduodenectomy. An experienced surgeon performed all operations in same fashion to minimize the surgical factor. A transanastomotic tube was inserted into the pancreatic duct for diversion of pancreatic juice in the pancreaticojejunostomy for a 3‐weeks period postoperatively. Intravenous infusion of somatostatin was given at a dose of 250μg/hr in the somastotatin group and normal saline was given to the control group for 7 days postoperatively. There was one perioperative death in each group, resulting in a 3.7% mortality rate. In the somastotatin group, as compared to the placebo group, the incidence of overall morbidity and pancreatic stump related complications were significantly lower with a mean decrease of 50% pancreatic juice output and a slightly shorter duration of hospital stays. In conclusion, after excluding surgeon related factor, prophylactic use of somatostatin reduces the incidence and severity of pancreatic stump related complications in high‐risk patients having pancreaticoduodenectomy via decreased secretion of pancreatic exocrine.
Laparoscopy‐assisted Repair of Diaphragm Injuries
Authors: Shaw John M. , Navsaria Pradeep H. , Nicol Andrew J.
Published: January 2004

In this study we review our experience with an alternative laparoscopy‐assisted technique for repair of diaphragm injuries. All patients admitted with an isolated diaphragm injury who underwent laparoscopy‐assisted repair between January 1996 and February 2000 were included in the study. The diagnosis of the diaphragm injury was either obvious, with omentum herniating through the chest wall, or occult with confirmation of the injury at laparoscopy. Repair of the diaphragm was performed using standard surgical instruments via a 4‐cm subcostal incision with use of abdominal wall traction and the laparoscope for visualization of the defect. A total of 24 patients underwent successful laparoscopy‐assisted repair; There were twenty men and four women with an average age of 28.8 years (range 23–49 years). The average Revised Trauma score was 12. There were 23 grade II and 2 grade III diaphragm injuries. The mean operative time was 61 minutes (range 25–120 minutes) and the average hospital stay from the time of surgery to the time of discharge was 2.29 days (range 1–4 days). The procedure failed in one patient as a result of gaseous distension of the bowel. One patient developed a tension pneumothorax, and two others developed atelectasis. Laparoscopic‐assisted repair of isolated diaphragm injuries using abdominal wall traction and standard surgical instruments is a feasible option with minimal morbidity and no mortality.
Current Management of Colon Trauma
Authors: Maxwell Robert A. , Fabian Timothy C.
Published: January 2004

This article offers a comprehensive review of colon trauma from World War I to the present. The process of evidence‐based medicine was used to analyze the data from the past 25 years and define standards of care in the field. Where data are less compelling, recommendations and suggestions are provided for future research. Topics highlighted include destructive and nondestructive colon injuries, rectal injuries, on‐table colonic lavage, colonic bypass tubes, risk factors, perioperative antibiotics, and colostomy closure.
Immunohistochemical Evaluation for Intraoperative Rapid Pathological Assessment of the Gastric Margin
Authors: Matsusaka Satoshi , Nagareda Tomohumi , Yamasaki Hajime , Kitayama Yoshihiro , Okada Toshihiro , Maeda Shigeto
Published: January 2004

In patients undergoing surgery for gastric cancer, as the resection area is difficult to define preoperatively, we define the resection area by intraoperative rapid pathological assessment of the resected margin. In some patients, however, the result of postoperative assessment of a permanent section differs from the result obtained intraoperatively. In this study we explored methods of improving the accuracy of intraoperative pathological assessment. Of the patients who underwent surgery for gastric cancer at Takarazuka Municipal Hospital, between April 2000 and July 2001, intraoperative pathological assessment of the resection margin was performed in 34 because it could not be accurately defined preoperatively. The intraoperative assessment consisted of touch smear cytological examination and hematoxylin and eosin (HE) and cytokeratin (CK) histological examination. The time required to perform cytological examination and HE and CK immunohistochemistry by this modified method, which uses an ENVISION Kit/HRP, was approximately 20 minutes for each procedure. Touch smear cytological examination gave false positive results in 3 of 34 patients (8.8%). Of the 14 patients preoperatively diagnosed with signet‐ring cell carcinoma, intraoperative HE histological analysis yielded a false negative result in one (7.1%). The results of CK histological assessment of these patients were all consistent with those of postoperative examination of permanent sections. Of the 20 patients preoperatively diagnosed with non‐signet‐ring cell carcinoma, HE analysis yielded a false negative result in one (5%). The results of CK histological assessment of these patients were all consistent with those of postoperative examination of permanent sections. Our modified CK staining method with the ENVISION Kit/HRP allows intraoperative pathological assessment to be performed accurately and rapidly. This method is more useful than HE immunohistochemistry for the assessment of resected gastric margins.
Risk Factors for Nonhepatic Surgery in Patients with Cirrhosis
Authors: del Olmo Juan A. , Flor‐Lorente Blas , Flor‐Civera Blas , Rodriguez Felicidad , Serra Miguel A. , Escudero Amparo , Lledó Salvador , Rodrigo José M.
Published: January 2004

Cirrhosis of the liver appears to have an unfavorable prognosis in the surgical patient. The aim of this study was to determine risk factors for morbidity and mortality in patients with cirrhosis undergoing nonhepatic surgery. We studied 135 patients with liver cirrhosis undergoing nonhepatic procedures and 86 controls matched by age, sex, and preoperative diagnosis. Preoperative, intraoperative, and postoperative variables associated with 30‐day mortality and morbidity were assessed by univariate and multivariate analyses. Patients with cirrhosis showed higher blood transfusion requirements, longer length of hospital stay, and a higher number of complications than controls. The mortality rate was 16.3% in cirrhotics and 3.5% in controls. By univariate analysis, the need for transfusions, prothrombin time, and Child‐Pugh score were significantly associated with postoperative liver decompensation, whereas duration of surgery, prothrombin time, Child‐Pugh score, cirrhosis‐related complications, and general complications were significantly associated with mortality. In the multivariate analysis, Child‐Pugh score (odds ratio [OR] 24.4; 95% confidence interval [CI] 5.5 to 106); duration of surgery (OR 5; 95% CI 1.2 to 15.6), and postoperative general complications (OR 3.7; 95% CI 3.4 to 6.4) were independent predictors of mortality. Patients with cirrhosis undergoing nonhepatic operations are at significant risk of perioperative complications leading to death. Independent variables associated with perioperative mortality include preoperative Child‐Pugh score, the duration of surgery, and the presence of postoperative general complications.
Itemized Bill: Novel Method to Audit the Process of Laparoscopic Cholecystectomy
Authors: Pal Khawaja Mohammad Inam , Ahmed Mushtaq
Published: January 2004

One of the recurring obstacles to the successful completion of a medical audit cycle is the unavailability of accurate and complete information. This is particularly evident in the review of clinical processes, where the hand‐written medical record is the source of information. We have attempted to bypass this information deficit by using information recorded primarily for financial transactions, using the itemized bill. The study was conducted in two parts. Initially information recorded as an itemized bill for the in‐hospital process of laparoscopic cholecystectomies over a one‐year period was analyzed. Areas for change in practice were identified, and recommendations were developed. These recommendations were presented to a multidisciplinary group consisting of consultants, residents, and nursing staff involved in caring for these patients. A clinical pathway was developed and implemented from these recommendations. One year after introduction, a review of the clinical pathway was undertaken using the same methodology. The in‐hospital process consisted of 23 charge categories according to the itemized bill. Of these, 8 accounted for 95% of the total charge. The surgeon’s fee and the anesthesiologist’s fee accounted for 34% of the total; medical/surgical supplies, 20%; operating theater time, 17%; pharmacy, 7%; radiology, 5%; laboratory, 7%; and ward, 4%. Areas were identified in the latter 6 categories for change. Review of practice 1 year after implementation of the changes showed that a large number of recommendations were in place. We describe a new method for auditing the processes of medical care, using the itemized bill to adapt and use information primarily recorded for financial purposes.
Doxorubicin Activity Is Enhanced by Hyperthermia in a Model of Ex Vivo Vascular Perfusion of Human Colon Carcinoma
Authors: Pilati Pierluigi , Mocellin Simone , Rossi Carlo R. , Scalerta Romano , Alaggio Rita , Giacomelli Luciano , Geroni Cristina , Nitti Donato , Lise Mario
Published: January 2004

There is little information on the pharmacokinetics and pharmacodynamics of doxorubicin (DXR) administered during locoregional treatments of colon carcinoma under hyperthermic conditions. The aim of this study was to evaluate distribution and activity of DXR in healthy tissue and tumor tissues under hyperthermic conditions by using an experimental model of ex vivo isolated vascular perfusion of human colon segments bearing primary carcinoma. The influence of topoisomerase‐IIα (TPI2α) expression on the anti‐cancer activity of DXR combined with heat was evaluated as well. Twenty seven colon segments surgically resected for primary carcinoma were perfused ex vivo under physiological conditions (group A, n = 7), with DXR (group B, n = 6), under hyperthermic conditions (group C, n = 6), and with the combination DXR–hyperthermia (group D, n = 8). Samples of perfusate and tissues (normal and pathologic) were collected during 90 minutes of perfusion. Doxorubicin concentration in perfusate and tissues was assessed with high‐performance liquid chromatography. Protein expression of TPI2α, the main molecular target of DXR, was measured by image analysis in normal mucosa and tumor samples. Drug uptake was increased by heat equally in healthy and diseased tissue. Under hyperthermic conditions, DXR activity was significantly higher in pathologic mucosa than in normal mucosa. Furthermore, the activity of DXR combined with heat correlated with baseline TPI2α levels in tumor tissue. From these findings, it appears that heat sensitizes tumor cells—but not normal mucosa—to DXR activity. Furthermore, protein levels of TPI2α in pretreatment samples could predict tumor sensitivity to DXR.
Persistent Primary Hyperparathyroidism Caused by Adenomas Identified in Pharyngeal or Adjacent Structures
Authors: Chan Teresa J. , Libutti Steven K. , McCart J. Andrea , Chen Clara , Khan Anjum , Skarulis Monica K. , Weinstein Lee S. , Doppman John L. , Marx Stephen J. , Alexander H. Richard
Published: January 2004

Abnormalities in the normal migration of the parathyroid glands during embryological development of the head and neck may result in considerable variability in the location of parathyroid tissue. Ectopic parathyroid adenomas present diagnostic and technical challenges and are frequently the cause of persistent primary hyperparathyroidism (HPT) after unsuccessful initial parathyroid surgery. We report a series of eight patients with persistent primary HPT who had adenomas in rare and unusual locations associated with various pharyngeal structures. Four were located within the epineurium of the vagus nerve at or above the level of the carotid bifurcation, and four were located within the paranasopharyngeal space or oropharynx. Noninvasive and invasive preoperative imaging studies were crucial in localizing the neoplasms in these patients and permitted the use of a direct surgical approach, resulting in cure in all patients and a low complication rate. The location of parathyroid glands in high pharyngeal and cervical structures is a consequence of anomalous or arrested descent through developing pharyngeal structures and illustrates the remarkable spectrum of ectopic parathyroid adenomas that occur secondary to this phenomenon.
Risk and Outcome of Bowel Resection in Patients with Incarcerated Groin Hernias: Retrospective Study
Authors: Kurt Necmi , Oncel Mustafa , Ozkan Zeynep , Bingul Sadik
Published: January 2004

The goal of this retrospective study was to evaluate factors that increase the risk of bowel necrosis and document the outcome of bowel resection in patients with strangulated hernias. We identified 102 patients (60 men, 42 women) who underwent surgical treatment for an incarcerated hernia at the Kartal Education and Research Hospital Emergency Unit between April 1997 and April 2001. Patients in group 1 required intestinal resection (n = 16), and patients in group 2 did not (n = 86). The median age of the patients was 53 years (range 3–96). Demographic and surgical data were obtained from the patients’ charts and compared between the two groups. Women required bowel resections more often than men (p < 0.05). Patients older than 65 years and those with femoral or epigastric hernias required resection more often than patients younger than 65 years and those with inguinal, umbilical, or incisional hernias (p < 0.05 for all). Group 1 patients had a longer hospitalization and experienced more overall complications and wound infections than group 2 (p < 0.05 for all). In conclusion, incarcerated hernias are more common in men, but intestinal resection is required more often in women. The risk of intestinal resection is higher for patients with femoral hernias and those older than 65 years. Patients who undergo intestinal resection have a higher overall complication rate related to wound infections but not an increased risk of other complications or mortality.
Physiologic Studies on Nitric Oxide in Rat Small Bowel Isografts
Authors: Tomita Ryouichi , Fujisaki Shigeru , Park Eichi , Kimizuka Kei
Published: January 2004

The enteric nervous system (ENS), especially the nonadrenergic noncholinergic (NANC) inhibitory nerves, is an important factor in intestinal peristalsis. Recently, it was established that nitric oxide (NO) is released after stimulation of NANC inhibitory nerves. Inhibitory nerves such as NANC inhibitory nerves in the ENS are more easily damaged than excitatory nerves by reperfusion or ischemic injuries during small bowel transplantation (SBT). To evaluate the effects of reperfusion and ischemic injuries to the ENS in the transplanted small bowel, we examined the ENS responses, including the effects of NO in the isografted rat jejunum, using the nontransplanted jejunum as a control. To avoid potentially confounding immune phenomena, we used syngeneic Lewis (LEW) rats. Orthotopic entire SBT with portocaval drainage was performed from LEW rats to LEW rats. Isografted muscle strips were obtained from 8 LEW rats 130 days after SBT (n = 24). As controls, normal muscle strips of the jejunum were obtained from 20 nontransplanted LEW rats (n = 60). A mechanograph was used to evaluate in vitro jejunal responses to electrical field stimulation of the adrenergic and cholinergic nerves before and after treatment with various autonomic nerve blockers, Ng‐nitro‐l‐arginine (L‐NNA), and l‐arginine. The results indicated that excitatory nerves, especially NANC excitatory nerves, were more dominant in the isografted jejunum than in the normal jejunum (p < 0.01). NANC inhibitory nerves were found to act on the normal jejunum and to a lesser extent on the isografted jejunum (p < 0.05). NO mediates the relaxation reaction of NANC inhibitory nerves in the normal jejunum and to a lesser extent in the isografted jejunum. These results indicated that the intrinsic intestinal innervation contains excitatory and inhibitory nerves and that the former, especially NANC excitatory nerves, are more dominant in the isografted jejunum than in the normal jejunum. In addition, reduction of the action of NANC inhibitory nerves such as that by NO may be largely related to impaired motility in the isografted jejunum. Thus over a long period of time (more than 130 days after SBT) transplanted small bowel dysmotility may be influenced by reperfusion or ischemic injury to the ENS (especially NANC inhibitory nerves) via NO in the transplanted jejunum after syngeneic SBT.
Transthoracic versus Transabdominal Surgical Approach for Echinococcal Cysts Located over the Superoposterior Aspect of the Right Lobe of the Liver
Authors: Smyrniotis Vassilios E. , Kostopanagiotou Elias K. , Farantos Charalampos I. , Katis Constantinos I. , Kostopanagiotou Georgia G.
Published: January 2004

A retrospective study of 80 patients operated on for hydatid cysts located on the superoposterior aspect of the right lobe of the liver (segments VI, VII, VIII) is presented. Right thoracotomy was performed in 30 patients, and 50 patients were operated on through bilateral subcostal incisions. The two approaches were compared in terms of radicality and morbidity. The transabdominal approach produced superior results and fewer postoperative complications, resulting in a shorter hospital stay (11 ± 5 vs. 18 ± 8 days). Total cystopericystectomy was feasible in 30% of patients operated on transabdominally and in 6% of those approached transthoracically. The rest of the patients were offered partial pericystectomy, except three in the thoracotomy group who underwent simple drainage of the cavity. We recommend that the transabdominal approach be the first choice for treatment of liver hydatid cysts irrespective of their location and size. We abandoned the transthoracic approach for cysts located on the superoposterior aspect of the right liver lobe in 1996. The transabdominal approach enables the surgeon to treat liver hydatidosis in a more radical, safer manner than does the transthoracic approach.
Chromoendoscopic Evaluation of Gastric Mucosa after Partial Gastrectomy by Use of Modified Endoscopic Congo Red Test
Authors: Tóth Ervin , Sjölund Kristina , Thorlacius Henrik
Published: January 2004

The need for partial gastrectomy has decreased as a result of reduced incidence and improved endoscopic and medical treatment of peptic ulcer disease. Nonetheless, several patients with resected stomach remain in the population, and it is well known that important pathological changes can occur in the gastric remnant. We evaluated the morphological and functional status of the gastric stump by use of modified endoscopic Congo red test (MCRT). For this purpose, 87 partially gastrectomized (Billroth I and II) patients referred for elective gastroscopy were consecutively enrolled. We found a high prevalence of severe chronic atrophic fundal gastritis (CAFG) (67%) in the gastric remnant. We also observed, however, that one‐third of the patients had almost unaffected gastric acid production even as long as 26 years after partial gastrectomy. Moreover, the accuracy, sensitivity, and specificity of routine gastroscopy in diagnosing CAFG in the gastric stump were found to be 55%, 50%, and 84%, respectively. The presence of bile reflux correlated well with the degree of CAFG. Importantly, we observed that more than 71% of the patients receiving acid‐suppressing therapy had no or very little capacity to produce gastric acid. Taken together, our study has demonstrated that MCRT is a simple and well‐tolerated method providing important morphological and functional information about the mucosa of the resected stomach. Furthermore, MCRT was superior to routine gastroscopy in diagnosing CAFG in the gastric stump. Outcome studies should define the clinical benefit of MCRT in the management of patients with resected stomach.
Pathophysiological Studies on the Relationship between Postgastrectomy Syndrome and Gastric Emptying Function at 5 Years after Pylorus‐preserving Distal Gastrectomy for Early Gastric Cancer
Authors: Tomita Ryouichi , Fujisaki Shigeru , Tanjoh Katsuhisa
Published: January 2004

Pylorus‐preserving distal gastrectomy (PPG) has frequently been performed on patients with early gastric cancer in Japan to prevent the postgastrectomy syndrome seen after conventional distal gastrectomy (CDG). The long‐term postoperative quality of life (QOL) and gastric emptying function in patients after PPG has not been assessed in detail. To clarify the usefulness of PPG for treating early gastric cancer we investigated the relation between postgastrectomy syndrome and gastric emptying function 5 years after PPG and then compared the results with those 5 years after CDG. Altogether, 32 patients who underwent curative gastrectomy at our clinic for early gastric cancer (submucosal cancer without lymph node metastasis) were studied. Ten subjects who underwent PPG with D2 lymphadenectomy without preserving the hepatic and pyloric branches of the vagal nerve [group A: eight men, two women; age 33–70 years (mean 60.7 years)] were interviewed and asked about appetite, weight loss, epigastric fullness, reflux esophagitis, and early dumping syndrome. They were compared with patients after CDG [group B: 36–72 years (mean 63.6 years)]. Esophagogastric endoscopy, abdominal ultrasonography, and gastric emptying function were also studied. The gastric emptying time of a semisolid diet was measured with a radioisotope method using 99mTc‐labeled rice gruel; the gastric emptying time of a liquid diet was measured with the acetaminophen method using orange juice. The control subjects (group C) consisted of 18 healthy volunteers (10 men, 8 women) without gastrointestinal symptoms aged 38 to 68 years (mean 60.8 years). The following results were obtained: PPG (group A) alleviated postoperative gastrointestinal symptoms such as appetite loss, reflux esophagitis, early dumping syndrome, lost body weight, endoscopic reflux esophagitis, endoscopic gastritis in the remnant stomach, and postogastrectomy cholecystolithiasis better than did CDG (group B). The only weak point with the PPG procedure was that it produced a feeling of epigastric fullness. The pattern of the gastric emptying curve for the semisolid diet was almost the same among groups A, B, and C, although delayed gastric emptying was clearly more frequent in group A than in group B or C (p < 0.05). Gastric emptying with the liquid diet in group B was significantly faster than that in groups A and C (p < 0.01). Gastric emptying in groups A and C was similar. These results showed that PPG improved the postoperative QOL, but the delayed emptying of semisolid diet after PPG led to a feeling of epigastric fullness after meals due to retention of contents in the residual stomach. Epigastric fullness after meals continued in many patients after PPG. Thus the only disadvantage of the PPG procedure is the sensation of epigastric fullness and gastric stasis due to delayed gastric emptying of a semisolid diet.
Risk Factors and Management of Bile Leakage after Hepatic Resection
Authors: Nagano Yasuhiko , Togo Shinji , Tanaka Kuniya , Masui Hidenori , Endo Itaru , Sekido Hitoshi , Nagahori Kaoru , Shimada Hiroshi
Published: January 2004

The aim of this study was to identify the perioperative risk factors for postoperative bile leakage after hepatic resection and to propose a treatment strategy for such leakage when it does occur. Between 1992 and 2000 a total of 313 hepatic resections without choledocojejunal anastomosis were performed at our institute. Risk factors related to bile leakage were identified with univariate analysis, and strategies were evaluated in relation to the findings of postoperative fistulography. Postoperative bile leakage developed in 17 patients (5.4%). Univariate analysis identified high risk factors as advanced age, a wide surface area of the incision (bile leakage group versus no bile leakage group: 102.1 vs. 66.4 cm2, p < 0.05), and exposure of Glisson’s sheath at the cut surface (e.g., central bisegmentectomy, S4, S8 subsegmentectomy). Groupings of patients by their postoperative fistulography results showed that patients with involvement of the proximal bile duct were slower to heal than those with no demonstrable bile duct involvement. The one patient whose fistulogram demonstrated peripheral bile duct involvement had uncontrollable leakage and required reoperation. Hepatectomies with a wide surface area and those that expose the major Glisson’s sheath present serious risk factors for bile leakage. When the fistulogram shows proximal bile duct involvement, endoscopic nasobiliary tube drainage is necessary; when the fistulogram shows peripheral bile duct involvement, reoperation is needed.
Diagnosis and Treatment of Inferior Vena Caval Invasion by Hepatic Cancer
Authors: Okada Yoshito , Nagino Masato , Kamiya Junichi , Yamamoto Hideo , Hayakawa Naokazu , Nimura Yuji
Published: January 2004

Hepatectomy with concomitant resection of the inferior vena cava (IVC) has become common for hepatic malignancies involving the IVC. However, diagnosing IVC invasion and the procedure of choice have yet to be standardized. Medical records of nine patients with liver cancer (five metastatic tumors from colorectal cancer and four intrahepatic cholangiocarcinomas) believed to have directly invaded the IVC wall were retrospectively abstracted for data on preoperative radiologic studies, surgical procedures, histology of the resected specimen, and treatment outcome. All nine patients underwent hepatectomy: Five did not undergo IVC resection because the IVC could be isolated from the tumor; the remaining four underwent combined IVC resection (wedge and segmental resections in two each). The segmentally resected IVC was reconstructed using an external iliac vein graft. Total hepatic vascular exclusion, venovenous bypass, and the ex vivo technique were not used. Interestingly, the tumor was smaller and the percentage of the IVC circumference in contact with tumor as seen on computed tomography (CT) was less in patients with IVC invasion than in those without it (40 ± 11 vs. 134 ± 61 mm, p < 0.05; 30% ± 8% vs. 60% ± 20%, p < 0.05). The length of the IVC compressed by tumor on cavography was similar in the two patient groups (47 ± 9 vs. 55 ± 8 mm). All patients were discharged from the hospital in good condition: Seven died of cancer recurrence, and the remaining two are currently alive and disease‐free 15 and 73 months after surgery, respectively. In conclusion, imaging modalities demonstrating caval deformation, such as CT and cavography, are unreliable for diagnosing direct invasion of the IVC wall. Even when IVC invasion is strongly suggested by conventional radiologic studies, the surgeon should endeavor to peel the tumor from the IVC. This strategy is important to avoid unnecessary resection of the IVC, use of a prosthetic graft, or ex vivo hepatectomy.
Carl Gussenbauer: Pioneer in Pancreatic Surgery
Authors: Schnelldorfer Thomas , Kitvarametha Yan Y. , Adams David B.
Published: January 2004

Carl Gussenbauer (1842–1903), known for many contributions to surgery, should also be noted prominently in the list of pioneers of pancreatic surgery. His successful performance of external drainage for a pancreatic cyst in 1882 was the first planned pancreatic operation. Although pancreatic surgery had been developed in animal models during the seventeenth century, surgery of the human pancreas was practically nonexistent owing to the dismal results seen with incidental pancreatic operations done early in the nineteenth century. Gussenbauer’s procedure was a significant advance, representing a safe and effective solution to the pancreatic cyst problem. Gussenbauer’s external drainage procedure remained the gold standard for treating pancreatic cysts until the 1920s and was still a widely practiced therapeutic option until the 1950s. With his discipline, insight, and innovative thought, Gussenbauer initiated the modern era of pancreatic surgery.
Change in Mitochondrial Membrane Potential in Peripheral Blood Lymphocytes, Especially in Natural Killer Cells, Is a Possible Marker for Surgical Stress on the Immune System
Authors: Takabayashi Arimichi , Kanai Michiyuki , Kawai Yasuhiro , Iwata Shingo , Sasada Tetsuro , Obama Kazutaka , Taki Yoshiro
Published: January 2004

There is accumulating evidence that surgical stresses cause impairment of systemic immune responses, which may promote susceptibility to infection as well as growth of remnant cancer cells in cancer patients. Although alterations in numbers, populations, and functions of lymphocytes have been extensively studied to assess modulation of the immune system, the precise mechanisms of immunosuppression caused by surgical stresses have not been identified, nor have methods been developed to estimate the magnitude of surgical stresses on the immune system. In the present study, to evaluate the effects of surgical procedures on the immune system, the mitochondrial membrane potential (ΔΨm) of peripheral blood lymphocytes (PBL) from 25 patients who underwent various types of operation was measured by flow cytometry using 3,3′‐dihexiloxacarbocyanine iodide (DiOC6(3)) on the day before operation and on postoperative day (POD) 1, POD 3, and POD 7. The ΔΨm in PBL, especially in natural killer (NK) cell population, was reduced after major surgery. In particular, the reduction of ΨΔm in NK cells appeared to be proportional to the severity of the surgical procedures and reflected the impairment of cellular function. Interestingly, the ΔΨm in NK cells was also negatively correlated with the level of plasma noradrenaline after major surgery, suggesting that the reduction of ΔΨm in NK cells induced by surgical stresses may bemediated, at least in part, by the accompanying increase in plasma noradrenaline. Monitoring of ΔΨm in PBL after operation may be one of the useful markers for estimating the magnitude of surgical stresses on the immune system.
Plastic Iodophor Drape during Liver SurgeryOperative Use of the Iodophor‐impregnated Adhesive Drape to Prevent Wound Infection during High Risk Surgery
Authors: Yoshimura Yasuko , Kubo Shoji , Hirohashi Kazuhiro , Ogawa Masao , Morimoto Ken , Shirata Kumiko , Kinoshita Hiroaki
Published: January 2004

We retrospectively investigated factors associated with wound infection after liver resection for hepatocellular carcinoma (HCC), with special reference to use of a plastic adhesive drape impregnated with iodophor. The subjects were 296 patients undergoing liver resection for HCC. Wound infection was defined as purulent drainage from the superficial incision with or without laboratory confirmation. One or more of the following signs was required: pain or tenderness, localized swelling, or redness or heat. Wound infection developed in 25 patients. Regression analysis indicated that low body mass index (BMI), smoking, long preoperative hospital stay, and nonuse of iodophor drapes were risk factors for wound infection. Wound infection was significantly less likely with the use of iodophor drapes (3.1%) than for surgery without iodophor drapes (12.1%). By multivariate regression analysis, BMI, smoking, and lack of drape use were independent risk factors. Most of the bacteria isolated were skin bacteria, including Staphylococcus aureus and Staphylococcus epidermidis. In conclusion, low BMI, smoking, a long preoperative hospital stay, and the lack of iodophor drape use were risk factors for wound infection after liver resection for HCC. The drapes presumably prevented contamination from the skin during the operation.