bluuebunny/crossref_metadata_2025 huggingface dataset:
Modification of a two‐component system by introducing an epoxy‐reactive diluent: Construction of a time–temperature–transformation (TTT) diagram
Authors: Núñez Lisardo , Villanueva M. , Núñez M. R. , Rial B. , Fraga L.
Published: February 2004

Curing reactions of a three‐component system consisting of an epoxy resin diglycidyl ether of bisphenol A (DGEBA n = 0), 1,2‐diaminecyclohexane as curing agent, and vinylcyclohexene dioxide as a reactive diluent were studied to calculate a time–temperature–transformation isothermal cure diagram for this system. Differential scanning calorimetry (DSC) was used to calculate the vitrification times. DSC data show a one‐to‐one relationship between Tg and fractional conversion α, independent of cure temperature. As a consequence, Tg can be used as a measure of conversion. The activation energy for the polymerization overall reaction was calculated from the gel times obtained using the solubility test (58.5 ± 1.3 kJ/mol). This value was similar to the results obtained for other similar epoxy systems. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 1190–1198, 2004
Influence of an epoxy reactive diluent on the thermal degradation process of the system DGEBA n = 0/1,2 DCH
Authors: Núñez Lisardo , Villanueva M. , Núñez M. R. , Rial B.
Published: February 2004

The thermal degradation of two epoxy systems diglycidyl ether of bisphenol A (DGEBA n = 0)/1,2‐diamine cyclohexane (DCH) containing different concentrations of an epoxy reactive diluent, vinylcyclohexene dioxide (VCHD), was studied by thermogravimetric analysis to determine the reaction mechanism of the degradation process for these two systems. Values of the activation energy, necessary for this study, were calculated by using various integral and differential methods. Values obtained by using the different methods were compared to the value obtained by Kissinger's method, which does not require a knowledge of the reaction mechanism. All the experimental results were compared to master curves in the range of Doyle's approximation (20–35% of conversion). Analysis of the results suggests that the two reaction mechanisms are Rn and Fn deceleratory type in contrast with the sigmoidal A2 type of the system with filler and the sigmoidal A4 type of the system without additives. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 1199–1207, 2004
Mechanical, hygroscopic, and thermal properties of metal particle and metal evaporated tapes and their individual layers
Authors: Bhushan Bharat , Tao Zhenhua
Published: February 2004

Mechanical and thermal properties of magnetic tapes and their individual layers strongly affect the tribology of magnetic head–tape interface and reliability of tape drives. Dynamic mechanical analysis, longitudinal creep, lateral creep, Poisson's ratio, the coefficient of hygroscopic expansion (CHE), and the coefficient of thermal expansion (CTE) tests were performed on magnetic tapes, tapes with front coat or back coat removed, substrates (with front and back coats removed), and never‐coated virgin films of the substrates. Storage modulus and loss tangent values were obtained at a frequency range from 0.016 to 28 Hz, and at a temperature range from −50 to 150 or 210°C. Longitudinal creep tests were performed at 25°C/50% RH, 40°C/25% RH, and 55°C/10% RH for 50 h. The Poisson's ratio and lateral creep were measured at 25°C/50% RH. CHE was measured at 25°C/15–80% RH. CTE values of various samples were measured at a temperature range from 30 to 70°C. The tapes used in this research included two magnetic particle (MP) tapes and two metal evaporated (ME) tapes that were based on poly(ethylene terephthalate) and poly(ethylene naphthalate) substrates. The master curves of storage modulus and creep compliance for these samples were generated for a frequency range from 10−20 to 1015 Hz. The effect of tape manufacturing process on the various mechanical properties of substrates was analyzed by comparing the data for the substrates (with front and back coats removed) and the never‐coated virgin films. A model based on the rule of mixtures was developed to determine the storage modulus, complex modulus, creep compliance, and CTE for the front coat and back coat of MP and ME tapes. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 1319–1345, 2004
Morphology and micromechanical deformation behavior of styrene–butadiene block copolymers. IV. Structure–property correlation in binary block copolymer blends
Authors: Adhikari R. , Michler G. H. , Henning S. , Godehardt R. , Huy T. A. , Goerlitz S. , Knoll K.
Published: February 2004

The structure–property correlation in blends consisting of styrene/butadiene block copolymers forming alternating polystyrene (PS) and polybutadiene (PB) lamellae, and PS domains in rubbery matrix was investigated by different microscopic techniques (transmission electron microscopy, scanning force microscopy, and scanning electron microscopy), uniaxial tensile testing, and dynamic mechanical analysis. Unlike the pure lamellar block copolymer, the blends showed predominantly disordered wormlike morphology formed by the intermolecular mixing. These structures allowed a precise control of stiffness/toughness ratio of the blends over a wide range. The blends showed a gradual transition from predominantly viscoplastic to elastomeric behavior with increasing triblock copolymer content. The results demonstrated that the binary block copolymer blends provide the unique possibility of tailoring mechanical properties on the basis of nanostructured polymeric materials. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 1219–1230, 2004
Effect of working conditions on the morphology of electrosynthesized polyfuran
Authors: del Valle M. A. , Ugalde L. , Díaz F. R. , Bodini M. E. , Bernède J. C.
Published: February 2004

The influence of electrolyte and deposition potential on polyfurane doped/undoped electrogenerated films was analyzed by potentiodynamic profiles and current–time transients. The films were formed on platinum electrodes from the monomer and tetrabutylammonium hexafluorophosphate, tetrabutylammonium tetrafluoroborate, or tetraethylammonium perchlorate in acetonitrile. Results were also discussed with the aid of X‐ray photoelectron spectroscopy (XPS), electron probe microanalysis (EPMA), and primarily by scanning electron microscopy (SEM). It was shown that there is some oxygen contamination not only after ClO4 doping. However, it was shown by XPS and EPMA that COC bonds are present in the films, which confirmed that there was no destruction of the furan ring during electropolymerization. SEM study showed film morphology evolution with monomer concentration, and with the electrolyte or the dopant used. The undoping effect was also visualized, showing that doped polyfuran was more homogeneous than the respective undoped deposits. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 1346–1354, 2004
Water diffusion in a soft contact lens polymer and its tolerance to UV radiation studied by positron lifetime technique
Authors: Thimmegowda M. C. , Ravi Kumar H. B. , Ranganathaiah C.
Published: February 2004

The kinetics of water sorption, the topology or the free‐volume changes due to the presence of sorbed water in a soft contact lens polymer, poly(2‐hydroxyethyl methacrylate), were investigated by using the positron lifetime technique. It was found that the ortho‐positronium lifetime increases in the beginning of sorption because of microstructural swelling of the polymer matrix. After reaching a maximum, the lifetime decreases and becomes constant, maybe because of the filling of the free‐volume holes with water molecules. The diffusion process is found to be non‐Fickian. By using the dual‐mode sorption model, the Fickian‐controlled part and the relaxation‐controlled part of diffusion were separated. Further, the positron results seem to indicate the existence of water clusters in the sorbed lens material. The tolerance or stability of the soft lens material to UV radiation seems to be satisfactory as revealed by positron results. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 1355–1366, 2004
Differential distribution of cubilin and megalin expression in the mouse embryo
Authors: Drake Christopher J. , Fleming Paul A. , Larue Amanda C. , Barth Jeremy L. , Chintalapudi Mastan R. , Argraves W. Scott
Published: February 2004

Cubilin and megalin are cell surface proteins that work cooperatively in many absorptive epithelia to mediate endocytosis of lipoproteins, vitamin carriers, and other proteins. Here we have investigated the coordinate expression of these receptors during mouse development. Our findings indicate that while there are sites where the receptors are co‐expressed, there are other tissues where expression is not overlapping. Apical cubilin expression is pronounced in the extraembryonic visceral endoderm (VE) of 6–9.5 days postcoitum (dpc) embryos. By contrast, little megalin expression is evident in the VE at 6 dpc. However, megalin expression in the VE increases as development progresses (7.5–9.5 dpc), although it is not as uniformly distributed as cubilin. Punctate expression of megalin is also apparent in the region of the ectoplacental cone associated with decidual cells, whereas cubilin expression is not seen in association with the ectoplacenta. Strong expression of megalin is observed in the neural ectoderm, neural plate and neural tube (6–8.5 dpc), but cubilin expression is not apparent in any of these tissues. At 8.5 dpc, megalin is expressed in the developing endothelial cells of blood islands, whereas cubilin is absent from these cells. Finally, cubilin, but not megalin, is expressed by a subpopulation of cells dispersed within the 7.5 dpc embryonic endoderm and having a migratory morphology. In summary, the co‐expression of cubilin and megalin in the VE is consistent with the two proteins functioning jointly in this tissue. However, the differential distribution pattern indicates that the proteins also function independent of one another. Furthermore, the finding of megalin expression in blood island endothelial cells and cubilin expression in embryonic endoderm highlight potential new developmental roles for these proteins. Anat Rec Part A 277A:163–170, 2004. © 2004 Wiley‐Liss, Inc.
Clonogenic analysis reveals reserve stem cells in postnatal mammals. II. Pluripotent epiblastic‐like stem cells
Authors: Young Henry E. , Duplaa Cecile , Yost Michael J. , Henson Nicholas L. , Floyd Julie A. , Detmer Kristina , Thompson Angela J. , Powell Steven W. , Gamblin T. Clark , Kizziah Kirk , Holland Benjamin J. , Boev Angel , Van De Water J.M. , Godbee Dan C. , Jackson Stephanie , Rimando Marylen , Edwards Chad R. , Wu Eveline , Cawley Chris , Edwards Pamela D. , Macgregor Anna , Bozof Ryan , Thompson T. Michele , Petro George J. , Shelton Heather M. , McCampbell Beth L. , Mills Jared C. , Flynt Frederick L. , Steele Timothy A. , Kearney Marianne , Kirincich‐Greathead Amy , Hardy Wade , Young Paul R. , Amin Aman V. , Williams R. Steve , Horton Miranda M. , Mcguinn Shaun , Hawkins Kristina C. , Ericson Kurt , Terracio Louis , Moreau Catherine , Hixson Douglas , Tobin Brian W. , Hudson John , Bowyer Frank P. , Black Asa C.
Published: February 2004

Undifferentiated cells have been identified in the prenatal blastocyst, inner cell mass, and gonadal ridges of rodents and primates, including humans. After isolation these cells express molecular and immunological markers for embryonic cells, capabilities for extended self‐renewal, and telomerase activity. When allowed to differentiate, embryonic stem cells express phenotypic markers for tissues of ectodermal, mesodermal, and endodermal origin. When implanted in vivo, undifferentiated noninduced embryonic stem cells formed teratomas. In this report we describe a cell clone isolated from postnatal rat skeletal muscle and derived by repetitive single‐cell clonogenic analysis. In the undifferentiated state it consists of very small cells having a high ratio of nucleus to cytoplasm. The clone expresses molecular and immunological markers for embryonic stem cells. It exhibits telomerase activity, which is consistent with its extended capability for self‐renewal. When induced to differentiate, it expressed phenotypic markers for tissues of ectodermal, mesodermal, and endodermal origin. The clone was designated as a postnatal pluripotent epiblastic‐like stem cell (PPELSC). The undifferentiated clone was transfected with a genomic marker and assayed for alterations in stem cell characteristics. No alterations were noted. The labeled clone, when implanted into heart after injury, incorporated into myocardial tissues undergoing repair. The labeled clone was subjected to directed lineage induction in vitro, resulting in the formation of islet‐like structures (ILSs) that secreted insulin in response to a glucose challenge. This study suggests that embryonic‐like stem cells are retained within postnatal mammals and have the potential for use in gene therapy and tissue engineering. Anat Rec Part A 277A:178–203, 2004. © 2004 Wiley‐Liss, Inc.
Granule types and their morphological changes in terminal cluster and acinar cells in the late pre‐ and early postnatal rat sublingual gland
Authors: Kikuchi Ken‐Ichiro , Aiyama Shigeo , Ikeda Rie , Matsuoka Takanori , Takada Kiyomi
Published: February 2004

The developmental characteristics of serous cells appearing in the rat sublingual gland from the late prenatal to the early postnatal period were investigated in this study. Particular attention was paid to the morphological changes observed in the secretory granules at the histochemical and ultrastructural level. On prenatal day 18, granules with homogeneous high electron density (Type I granules), and mottled granules (Type II granules) with heterogeneous electron density appeared in the narrow luminar cytoplasm of cells constituting the terminal clusters. On prenatal day 19, these granules decreased in number and were replaced by bipartite granules (Type III granules) composed of a highly electron‐dense core and a more electron‐lucent rim. Pronase treatment almost completely digested the Type I and II granules and the electron‐dense core of the Type III granules, although some of the Type I and II granules in serous demilunes at a later stage were insufficiently digested. On prenatal day 19.5, homogeneous granules of low electron density (Type IV granules) appeared in the terminal clusters and acini, and increased in number daily, making up 92.8% of the total granules on postnatal day 28. The granule morphology on electron microscopy, Alcian blue, and periodic acid‐Schiff staining strongly suggested that Type I and II granules were serous granules, Type IV granules were mucous granules, and Type III granules were transforming‐type granules. None of the secretory cells showed chromatin condensation, which is a characteristic of apoptosis. These findings suggest that the developing rat sublingual gland from the late prenatal to early postnatal period has numerous serous granules in the terminal clusters and acini, and that the majority of granules are replaced by mucous granules through transforming‐type granules. In addition, because apoptotic figures of secretory cells could not be detected, it appears that most of the serous cells in the developing rat sublingual gland might have changed to mucous cells. Anat Rec Part A 277A:209–215, 2004. © 2004 Wiley‐Liss, Inc.
Total number and mean size of alveoli in mammalian lung estimated using fractionator sampling and unbiased estimates of the Euler characteristic of alveolar openings
Authors: Hyde D.M. , Tyler N.K. , Putney L.F. , Singh P. , Gundersen H.J.G.
Published: February 2004

Estimation of alveolar number in the lung has traditionally been done by assuming a geometric shape and counting alveolar profiles in single, independent sections. In this study, we used the unbiased disector principle to estimate the Euler characteristic (and thereby the number) of alveolar openings in rat lungs and rhesus monkey lung lobes and to obtain robust estimates of average alveolar volume. The estimator of total alveolar number was based on systematic, uniformly random sampling using the fractionator sampling design. The number of alveoli in the rat lung ranged from 17.3 · 106 to 24.6 · 106, with a mean of 20.1 · 106. The average number of alveoli in the two left lung lobes in the monkey ranged from 48.8 · 106 to 67.1 · 106 with a mean of 57.7 · 106. The coefficient of error due to stereological sampling was of the order of 0.06 in both rats and monkeys and the biological variation (coefficient of variance between individuals) was 0.15 in rat and 0.13 in monkey (left lobe, only). Between subdivisions (left/right in rat and cranial/caudal in monkey) there was an increase in variation, most markedly in the rat. With age (2−13 years) the alveolar volume increased 3‐fold (as did parenchymal volume) in monkeys, but the alveolar number was unchanged. This study illustrates that use of the Euler characteristic and fractionator sampling is a robust and efficient, unbiased principle for the estimation of total alveolar number in the lung or in well‐defined parts of it. Anat Rec Part A 274A:216–226, 2004. © 2004 Wiley‐Liss, Inc.
Adverse histopathological findings as a guide to patient management after curative resection of node-positive colonic cancer
Authors: Chapuis P H , Dent O F , Bokey E L , Newland R C , Sinclair G
Published: February 2004

Background

The aim of this study was to identify patient and tumour characteristics that might assist in developing an improved approach to patient selection for chemotherapy after resection of clinicopathological stage C colonic cancer.

Methods

Clinical, pathological and follow-up data have been collected prospectively for all patients undergoing resection for colorectal cancer at Concord Hospital since 1971. From an initial 2980 patients, after exclusions 378 remained who had a potentially curative operation for colonic cancer with nodal metastases and did not receive adjuvant chemotherapy. Associations between several pathological features and survival were examined by proportional hazards regression.

Results

In a multivariate model, both overall and colonic cancer-specific survival rates were negatively associated with serosal surface involvement, apical node metastasis, high histological grade and venous invasion. The survival of patients with stage C disease who had none of these adverse features was not significantly different from that of patients with stage B lesions. However, survival diminished significantly when one or more of the adverse features were present.

Conclusion

Patients with a stage C tumour but with none of the identified adverse features experience relatively good survival and are unlikely to benefit from adjuvant chemotherapy. In this series such patients accounted for 40·5 per cent of patients with stage C disease.
Right hemicolectomy does not confer a survival advantage in patients with mucinous carcinoma of the appendix and peritoneal seeding
Authors: González-Moreno S , Sugarbaker P H
Published: February 2004

Background

Traditionally epithelial malignancies of the appendix with or without carcinomatosis have been treated by right hemicolectomy. Recent accumulation of a large number of patients with this disease has enabled a re-evaluation of this surgical judgement.

Methods

Clinical data on 501 patients with epithelial malignancy of the appendix were collected prospectively. All patients had peritoneal seeding at the time of referral and were treated by cytoreductive surgery and perioperative intraperitoneal chemotherapy. The main independent variable for statistical analysis was the surgical procedure used to resect the primary cancer (appendicectomy alone versus right hemicolectomy). Nineteen other clinical and pathological variables were considered as control variables. The endpoint for all analyses was survival.

Results

Median follow-up after the initial diagnosis was 4 years. The rate of regional lymph node positivity was 5·0 per cent. When the incidence of lymph node metastasis was determined by histological type, it was statistically significantly higher in intestinal (66·7 per cent) than in mucinous (4·2 per cent) tumours (P < 0·001). The presence of lymph node metastases had no influence on prognosis (P = 0·155). The surgical procedure (appendicectomy alone versus right hemicolectomy) had an influence on patient survival by univariate analysis (P < 0·001), but not by multivariate analysis (P = 0·258).

Conclusion

Right hemicolectomy does not confer a survival advantage in patients with mucinous appendiceal tumours with peritoneal seeding. These data suggest that right hemicolectomy should be avoided unless metastatic involvement of the appendiceal or distal ileocolic lymph nodes is documented by biopsy, or the resection margin is inadequate.
Routine day-case laparoscopic cholecystectomy
Authors: Leeder P C , Matthews T , Krzeminska K , Dehn T C B
Published: February 2004

Background

A prospective study was carried out to assess the feasibility of performing true day-case laparoscopic surgery in a district general hospital.

Methods

All patients admitted consecutively under the care of one surgeon for laparoscopic cholecystectomy were included in the study. Selection criteria for a day-case procedure included an American Society of Anesthesiologists grade of I or II and the availability of a responsible carer at home. Patients were discharged 4–6 h after surgery with a standard analgesia pack and a contact number for advice. All patients were contacted by telephone on the day after discharge. A postal questionnaire was sent to the first 100 patients to assess satisfaction with the day-case process.

Results

Of 357 patients admitted for laparoscopic cholecystectomy over a 24-month period, 154 (43·1 per cent) were operated on as day cases on a morning theatre list. Twenty-two patients required an overnight stay (14·3 per cent), three because of conversion to an open procedure. One patient was readmitted for neck pain. Eighty-two (92·1 per cent) of 89 patients were either satisfied or very satisfied with the day-case procedure.

Conclusion

This study has demonstrated a low rate of overnight stay (14·3 per cent) and readmission (1·9 per cent), and a high degree of patient satisfaction for day-case laparoscopic cholecystectomy.
Management of blunt liver trauma in a tertiary referral centre
Authors: Coughlin P A , Stringer M D , Lodge J P A , Pollard S G , Prasad K R , Toogood G J
Published: February 2004

Background

In recent years, several reports from North America have highlighted the success of conservative treatment in patients with blunt liver trauma. The aim of this study was to identify trends in the management of blunt liver trauma in a UK tertiary referral centre dealing with both adults and children over a 10-year period.

Methods

A retrospective case note review was performed on 71 consecutive patients (58 male patients) of median age 25 years admitted to the hepatobiliary unit over the 10-year period from 1992 to 2001 with blunt liver trauma. Data relating to referring source, severity of liver injury, initial and subsequent management and outcome were collected using a standard pro forma.

Results

Sixty-two of the 71 patients were referred from other surgical units. Of these, 14 had undergone laparotomy at the referring hospital, with ten having perihepatic packing; the other 48 were managed conservatively. Of the 62 patients transferred to the authors' unit, 12 required surgical intervention for the liver injury. The mean number of patients with blunt liver trauma increased between the first second 5-year periods, from 3·2 to 11·0 patients per year. There was a significant reduction in the proportion of patients requiring surgery for the liver injury in both the authors' unit (from seven of 16 patients in 1992–1996 to seven of 55 in 1997–2001; P = 0·017, χ2 test) and referring hospitals (from six of 12 to eight of 50; P = 0·014, χ2 test). The reduction in the mortality rate, from two (12·5 per cent) of 16 in the first period to four (7·3 per cent) of 55 in the second, was not significant (P = 0·880, χ2 test).

Conclusion

This study demonstrated a marked increase in the number of patients with blunt liver trauma referred to a regional hepatobiliary centre in recent years. It has confirmed that the majority of such patients can be treated successfully without surgery.
Chinese experience with hepatectomy for huge hepatocellular carcinoma
Authors: Chen X P , Qiu F Z , Wu Z D , Zhang B X
Published: February 2004

Background

The risks and outcome of hepatic resection for huge hepatocellular carcinoma (HCC) are controversial.

Methods

The clinical records of 525 patients who underwent resection of HCC greater than 10 cm in diameter were studied retrospectively. Prognostic factors for long-term survival were evaluated by univariate and multivariate analyses.

Results

Postoperative complications were common (26·8 per cent) and five patients (0·9 per cent) required relaparotomy. The 30-day mortality rate was 2·7 per cent. The main causes of postoperative death were liver failure (nine patients) and bleeding (four). The 3-, 5- and 10-year crude survival rates after liver resection were 34·3, 16·8 and 2·9 per cent respectively.

Conclusion

Prognostic factors for long-term survival mainly reflected the biological behaviour of the tumour. They can be used only as a guide in balancing the risks of operation against the potential benefits of resection in a patient in poor general condition or with poor liver function. They cannot be used alone to exclude patients from liver resection with curative intent. Liver resection for huge HCC was safe and efficacious. It should be used to treat patients with acceptable surgical risks and resectable tumours.
Risk-adjusted prediction of operative mortality in oesophagogastric surgery with O-POSSUM
Authors: Tekkis P P , McCulloch P , Poloniecki J D , Prytherch D R , Kessaris N , Steger A C
Published: February 2004

Introduction

The present study was designed to develop a dedicated oesophagogastric model for the prediction of risk-adjusted postoperative mortality in upper gastrointestinal surgery (O-POSSUM).

Methods

Using 1042 patients undergoing oesophageal (n = 538) or gastric (n = 504) surgery between 1994 and 2000 the Portsmouth predictor equation for mortality (P-POSSUM) scoring system was compared with a standard logistic regression O-POSSUM model and a multilevel O-POSSUM model using the following independent factors: age, physiological status, mode of surgery, type of surgery and histological stage.

Results

The overall mortality rate was 12·0 per cent (elective mortality rate 9·4 per cent and emergency mortality rate 26·9 per cent). P-POSSUM overpredicted mortality (14·5 per cent), particularly in the elective group of patients. The multilevel model offered higher discrimination than the single-level O-POSSUM and P-POSSUM models (area under receiver–operator characteristic curve 79·7 versus 74·6 and 74·3 per cent). When observed to expected outcomes were evaluated, the multilevel O-POSSUM model was found to offer better calibration (Hosmer–Lemeshow χ2 statistic 10·15 versus 10·52 and 28·80).

Conclusion

The multilevel O-POSSUM model provided an accurate risk-adjusted prediction of death from oesophageal and gastric surgery for individual patients. In conjunction with a multidisciplinary approach to patient management, the model may be used in everyday practice for perioperative counselling of patients and their carers.
Randomized clinical trial of the use of a prosthetic mesh to prevent parastomal hernia
Authors: Jänes A , Cengiz Y , Israelsson L A
Published: February 2004

Background

Parastomal hernia is a common complication following colostomy, and repair with a prosthetic mesh is associated with the lowest recurrence rate. The aim of this study was to determine the effect on stoma complications of using a mesh at the primary operation.

Methods

Patients undergoing permanent colostomy were randomized to have either a conventional stoma or the addition of a mesh placed in a sublay position. A large-pore lightweight mesh with a reduced polypropylene content and a high proportion of absorbable material was used.

Results

Twenty-seven patients were randomized to have a conventional stoma and 27 to have the mesh. No infection, fistula formation or pain occurred (observation time 2–28 months). At the 12-month follow-up, parastomal hernia was present in eight of 18 patients without a mesh and in none of 16 patients in whom the mesh was used.

Conclusion

A lightweight prosthetic mesh in a sublay position at the stoma site was not associated with infection or other early complications. Preliminary results indicate that the mesh prevented the development of parastomal hernia.
Predictors of extrahepatic recurrence after resection of colorectal liver metastases
Authors: Ueno H , Mochizuki H , Hashiguchi Y , Hatsuse K , Fujimoto H , Hase K
Published: February 2004

Background

It is important to identify patients at high risk of extrahepatic recurrence after surgery for liver metastases, in order to maximize the survival benefit obtained by prophylactic regional chemotherapy.

Methods

Data from 68 patients who underwent resection of colorectal liver metastases but who did not receive hepatic arterial chemotherapy or intravenous systemic chemotherapy were collected. Twenty-two variables were examined by univariate and multivariate analyses to determine which factors were relevant to extrahepatic recurrence. A scoring system was developed that included the most relevant factors.

Results

The extrahepatic recurrence rate at 3 years after hepatectomy was 57·8 per cent. Three variables were independently associated with extrahepatic recurrence including raised serum level of carcinoembryonic antigen after hepatectomy (relative risk (RR) 5·4, P < 0·001), venous invasion of the primary tumour (RR 4·0, P = 0·001) and high-grade budding of the primary tumour (RR 3·1, P = 0·006). Patients with none of these risk factors had a 3-year extrahepatic recurrence rate of 7·1 per cent, compared with 61·6 per cent for those with one risk factor and 100 per cent for those with two or three risk factors.

Conclusion

It was possible to identify patients at high risk of disease relapse at extrahepatic sites. This system might be used on an individual basis to select patients with colorectal liver metastases for regional chemotherapy or systemic chemotherapy after surgical intervention.
Comparison of old and new TNM systems for nodal staging in adenocarcinoma of the gastro-oesophageal junction
Authors: de Manzoni G , Pedrazzani C , Verlato G , Roviello F , Pasini F , Pugliese R , Cordiano C
Published: February 2004

Background

Adenocarcinoma of the gastro-oesophageal junction is considered a distinct clinical entity, although the current pathological tumour node metastasis (pTNM) classification does not consider this tumour specifically. A prospective study was undertaken to determine the prognostic importance of lymph node involvement in adenocarcinoma of the gastro-oesophageal junction, analysing both a number- and site-based classification, in order to develop a clinically useful nodal staging system.

Methods

Two classification systems were analysed in 116 patients who underwent resection for adenocarcinoma of the gastro-oesophageal junction from January 1988 to August 2001. The Cox regression model was used to evaluate the prognostic significance of the site and number of positive nodes.

Results

The number- and site-based staging systems coincided only in 42 (56 per cent) of 75 patients; in particular, the old pN1 classification was upstaged in 13 of 41 patients and the old pN2 was downstaged in 13 of 34 patients. Lymph node involvement was the most important prognostic factor in both classifications (P < 0·001). The risk of death was significantly influenced by the site of nodal metastasis among patients with a similar number of involved nodes (relative risk with respect to pN0: 2·18 for pN1 with one to six nodes; 6·53 for pN2 with one to six nodes; 7·53 for pN1 with more than six nodes; 39·13 for pN2 with more than six nodes).

Conclusion

Adenocarcinoma of the gastro-oesophageal junction requires a specific lymph node classification which should take into account both the number and site of nodal metastases.
Hand-assisted laparoscopic live donor nephrectomy
Authors: Maartense S , Idu M , Bemelman F J , Balm R , Surachno S , Bemelman W A
Published: February 2004

Background

Hand-assisted laparoscopic donor nephrectomy (HLDN) may have advantages over laparoscopic donor nephrectomy, such as shorter learning curve, operation and warm ischaemia times. The aim of this study was to evaluate the feasibility and safety of HLDN.

Methods

Between January 2000 and October 2002, 50 consecutive HLDN procedures were performed through a low transverse abdominal incision, 23 right sided and 27 left sided.

Results

The median age of the donors was 44 years. No HLDN required conversion to an open procedure. The median operating time for HLDN was 153 min. The median warm ischaemia time was 3 (range 1·0–4·5) min and the median blood loss was 50 (range 20–500) ml in both left- and right-sided procedures. Eight patients suffered ten minor complications during their admission. The duration of hospital stay was 5 days for donors. Three recipients developed graft failure owing to acute rejection, renal vein thrombosis and ischaemic necrosis.

Conclusion

Both left- and right-sided HLDN procedures were feasible and safe through a low transverse abdominal incision.
Randomized clinical trial of morbidity after D1 and D3 surgery for gastric cancer
Authors: Wu C W , Hsiung C A , Lo S S , Hsieh M C , Shia L T , Whang-Peng J
Published: February 2004

Background

A randomized comparison of D1 (level 1 lymphadenectomy) and D3 (levels 1, 2 and 3 lymphadenectomy) dissection was performed to evaluate morbidity and effects on survival from gastric cancer.

Methods

A total of 221 patients were studied after resection for gastric cancer, 110 after D1 surgery and 111 after D3 surgery.

Results

The morbidity rate was higher after D3 than after D1 resection (17·1 (95 per cent confidence interval (c.i.) 10·1 to 24·1) versus 7·3 (95 per cent c.i. 2·4 to 12·2) per cent respectively; P = 0·012). The difference was largely related to abdominal abscess (8·1 per cent after D3 versus none after D1 resection; P = 0·003). The D3 group had an anastomotic leak rate of 4·5 per cent whereas there was no leakage in the D1 group (P = 0·060). All anastomotic leaks were minor and were managed non-operatively with nutritional support. Patients who had D3 resection had longer operating times, greater blood loss and postoperative drain outputs, and more patients needed blood transfusion. There was no death in either group. The hospital stay was longer after D3 than D1 surgery (mean(s.d.) 19·6(13·9) (range 10–98) versus 15·0(4·0) (range 10–30) days; P = 0·001).

Conclusion

Extended lymphadenectomy for gastric cancer is associated with more complications than limited lymphadectomy but this does not lead to significant mortality.
Convalescence after inguinal herniorrhaphy
Authors: Bay-Nielsen M , Thomsen H , Andersen F Heidemann , Bendix J H , Sørensen O K , Skovgaard N , Kehlet H
Published: February 2004

Background

Convalescence after inguinal herniorrhaphy is usually 3–4 weeks and is an important outcome parameter of hernia surgery. The aim of this study was to describe in detail the consequences of recommending a short convalescence, including the risk of recurrence.

Methods

This was a multicentre prospective questionnaire study in patients given a recommendation for short convalescence (1 day); information was recorded on expected length of convalescence, employment status, physical workload and limiting factors. The reoperation rate in patients included in the study (group 1, n = 1059) was compared with that for comparable patients treated in participating departments but not part of the study group (group 2, n = 1306) and patients in the Danish Hernia Database (group 3, n = 8297).

Results

The median time off work was 7 days and the time interval before carrying out the most strenuous leisure activity was 14 days. After 30 days, 6·8 per cent of patients had not resumed employment and 17·0 per cent had not yet resumed strenuous leisure activity. Important reasons for not resuming work and leisure activity were pain (approximately 60 per cent of patients) and wound problems (approximately 20 per cent). The reoperation rate in group 1 at the median observation time was 0·7 per cent, which was no different to that in group 2 (1·6 per cent) (P = 0·186) or group 3 (1·4 per cent) (P = 0·092).

Conclusion

Reduced convalescence after inguinal herniorrhaphy may be recommended without incurring a risk of higher reoperation rates. Pain and wound problems remain the most important factors for not resuming work or leisure activity as recommended.
Microvessel density, cyclo-oxygenase 2 expression, K-ras mutation and p53 overexpression in colonic cancer
Authors: Liang J-T , Huang K-C , Jeng Y-M , Lee P-H , Lai H-S , Hsu H-C
Published: February 2004

Background

Tumour angiogenesis, cyclo-oxygenase (COX) 2 expression, K-ras mutation and p53 overexpression are commonly involved in colorectal tumorigenesis, but their interrelationship and clinicopathological effects remain inconclusive.

Methods

Clinicopathological data from 114 consecutive patients with primary stage III colorectal cancer were evaluated prospectively. Microvessel density (MVD) of the tumour was defined by counting the number of microvessels in hotspots, visualized by immunocytochemical staining of endothelial CD34. K-ras mutation was analysed by the restriction enzyme cleavage method. COX-2 expression and p53 overexpression were determined by immunocytochemistry.

Results

Increased MVD in hotspots was significantly associated with COX-2 expression (P < 0·001), K-ras mutation (P = 0·007) and p53 overexpression (P = 0·006). COX-2 expression was not associated with either K-ras mutation or p53 overexpression. Clinicopathologically, greater MVD and COX-2 expression were significantly associated with vascular invasion of cancer cells (MVD, P = 0·027 and COX-2 expression, P = 0·006), but p53 overexpression and K-ras mutation were not. Multivariate analysis indicated that greater MVD (P = 0·002) and p53 overexpression (P = 0·016) were significant independent predictors of tumour recurrence, whereas COX-2 expression (P = 0·634) and K-ras mutation (P = 0·356) were not.

Conclusion

Tumour angiogenesis may be associated with tumour metastasis and is significantly influenced by K-ras mutation, p53 overexpression and COX-2 expression in patients with colonic cancer.
Impact of radiofrequency ablation on the management of patients with hepatocellular carcinoma in a specialized centre
Authors: Lam C-M , Ng K K-C , Poon R T-P , Ai V , Yuen J , Fan S-T
Published: February 2004

Background

Radiofrequency ablation (RFA) has been used increasingly in the treatment of hepatocellular carcinoma (HCC). The aim of this study was to investigate changes in the treatment pattern of primary HCC following the implementation of RFA in a specialized surgical centre.

Methods

This was a retrospective analysis of all 894 patients admitted for treatment of primary HCC over 36 months.

Results

There was no difference in the age, sex ratio, liver function according to Child–Pugh grade, serum α-fetoprotein concentration, hepatitis B surface antigen status and tumour size among patients before and after the introduction of RFA therapy. Fifty-one patients (10·6 per cent) with primary HCC received RFA treatment after its implementation. There was a 6·8 per cent reduction in the number of patients who had supportive treatment (P = 0·041) and a 3·2 per cent reduction in surgical treatment. The hospital mortality rates for RFA and surgery were 2·0 and 4·9 per cent respectively. The overall survival rates at 6, 12 and 18 months for patients treated with RFA were 92·2, 73·4 and 61·2 per cent respectively. The corresponding survival rates for the 213 patients who had surgery were 88·0, 77·0 and 71·5 per cent. These values were no different from those in patients who had RFA (P = 0·718). Patients treated with RFA or surgery survived longer than those who had other treatments.

Conclusion

RFA had a significant impact on the management of primary HCC, increasing the number of patients suitable for liver-directed therapy and leading to survival benefit. RFA may become the treatment of choice for patients with irresectable HCC.
Carcinogenic potential of commonly used hernia repair prostheses in an experimental model
Authors: Witherspoon P , Bryson G , Wright D M , Reid R , O'Dwyer P J
Published: February 2004

Background

The purpose of this study was to assess the carcinogenic potential of commonly used hernia repair prostheses in an animal model.

Methods

Three types of prosthetic material (monofilament polypropylene, multifilament polypropylene and expanded polytetrafluoroethylene) were implanted in CBA/H mice. Flat (1 cm2) and rolled pieces of the same material were placed subcutaneously in either flank, and a further flat piece was placed in the preperitoneal space. Owing to a high incidence of mesh extrusion in the polypropylene groups, the study protocol was modified to allow only preperitoneal placement of the material. A fourth, control, group had the pockets for the prostheses created but no material implanted. After modification of the protocol there were approximately 60 mice in each group. The mice were followed for 2 years, then killed and assessed histologically for tumour development.

Results

No sarcoma developed at the site of mesh implantation in any of the groups.

Conclusion

This study indicates that the risk of sarcoma formation at the site of hernia repair prostheses is very low.
Legislative threat to clinical science–the obfuscation and de-identification of protected health information
Authors: Galandiuk S
Published: February 2004

A salutary tale
Drawbacks of endoscopic thoracic sympathectomy
Authors: Ojimba T A , Cameron A E P
Published: February 2004

Background

Endoscopic thoracic sympathectomy (ETS) has come into widespread use for palmar hyperhidrosis and other complaints of the upper limb and of the head and neck, but there are concerns about its safety. This review highlights the operative complications and long-term side-effects that may occur.

Methods

A Medline search was carried out using the terms ‘thoracoscopic sympathectomy’, ‘endoscopic thoracic sympathectomy’ and ‘complications’. References from identified articles were handsearched for further relevant articles. The senior author's experience and personal communications were also taken into account.

Results and conclusion

No death following ETS has ever been reported in the literature, but nine anecdotal fatalities are known, five resulting from major intrathoracic bleeding and three from anaesthetic mishap. Significant intrathoracic bleeding may occur in up to 5 per cent of patients but only a minority require thoracotomy; pneumothorax occurs in 2 per cent of patients and two instances of brain damage are known. In the longer term compensatory hyperhidrosis is extremely common and 1–2 per cent of patients regret having had surgery because of its severity. Horner's syndrome, on the other hand, is rare. Improvements in instrumentation, adequate training and careful patient selection may help reduce the drawbacks of ETS.
Chronic anal fissure
Authors: Lindsey I , Jones O M , Cunningham C , Mortensen N J McC
Published: February 2004

Background

The treatment of chronic anal fissure has shifted in recent years from surgical to medical.

Methods

A Medline search of studies relevant to modern management of chronic anal fissure was undertaken.

Results

Traditional surgery that permanently weakens the internal sphincter is associated with a risk of incontinence. Medical therapies temporarily relax the internal sphincter and pose no such danger, but their limited efficacy has led to displacement rather than replacement of traditional surgery. Emerging medical therapies promise continued improvement and new sphincter-sparing surgery may render traditional surgery redundant.

Conclusion

First-line use of medical therapy cures most chronic anal fissures cheaply and conveniently. The few non-responders can be targeted for sphincter assessment before traditional surgery. If the initial good results of new sphincter-sparing surgery are confirmed, it may be possible to avoid any risk of incontinence, while achieving high rates of fissure healing.
Uncovering occult operative morbidity and mortality
Authors: Collin J , Murie J
Published: February 2004

Take off the rose tinted spectacles
Letter 1: Preoperative treatment of hepatocellular carcinoma with intra-arterial injection of 131I-labelled lipiodol (Br J Surg 2003; 90: 1379-1383)
Authors: Rai R , Rai S
Published: February 2004

The Editors welcome topical correspondence from readers relating to articles published in the Journal. Responses can be sent electronically via the BJS website (www.bjs.co.uk) or by post. All letters will be reviewed and, if approved, appear on the website. A selection of these will be edited and published in the Journal. Letters must be no more than 250 words in length. Letters submitted by post should be typed on A4-sized paper in double spacing and should be accompanied by a disk.
Morphological studies for retrusive movement of the human adult tongue
Authors: Saigusa Hideto , Yamashita Kazuo , Tanuma Kumiko , Saigusa Makoto , Niimi Seiji
Published: February 2004

This study identified the anatomical and close functional relationship between the transverse lingual and superior pharyngeal constrictor muscle. Two en bloc samples (including the tongue and mid‐pharyngeal wall) and four whole tongues were obtained from adult human cadavers. We found that fibers of the superior pharyngeal constrictor muscle connected with fibers of the transverse lingual muscle, forming a ring of muscle at the base of the tongue. The average diameters of the transverse muscle fibers increased in size gradually as they approached the base of the tongue. Distribution of the muscle spindles in the transverse lingual muscle and the genioglossus muscle also increased as they reached posteriorly near the base of the tongue. These findings suggest that a ring of muscle formed by the postero‐inferior portion of the transverse lingual muscle and the superior pharyngeal constrictor may be largely responsible for the retrusive movement of the tongue and the constrictive movement of the pharyngeal cavity as an antagonist of the genioglossus muscle. Clin. Anat. 17:93–98, 2004. © 2004 Wiley‐Liss, Inc.