bluuebunny/crossref_metadata_2025 huggingface dataset:
Macrokinetic and quantitative microbial investigation on a bench‐scale biofilter treating styrene‐polluted gaseous streams
Authors: Zilli Mario , Converti Attilio , Di Felice Renzo
Published: May 2003

We performed a macrokinetic and quantitative microbial investigation of a continuously operating bench‐scale biofilter treating styrene‐polluted gases. The device was filled with a mixture of peat and glass beads as packing medium and inoculated with the styrene‐oxidizing strain, Rhodococcus rhodochrous AL NCIMB 13259. The experimental data of styrene and microbial concentrations, obtained at different biofilter heights, were used to evaluate the pollutant concentration profiles as well as the influence of styrene loading on biomass distribution along the packing medium. Styrene and biomass concentration profiles permitted detection of a linear relationship between the amount of biomass grown in a given section of the biofilter and that of pollutant removed, regardless of the operating conditions tested. Biomass development in the bed appeared to: depend linearly on pollutant concentration at an inlet styrene concentration of <0.10 g m−3 in the gaseous stream; achieve a maximum value (7 · 107 colony forming units per gram of packing material) within a wide styrene concentration range (0.10 to 1.0 g m−3); and fall sharply beyond this inhibition threshold. The process followed zeroth‐order macrokinetics with respect to styrene concentration, which is consistent with zeroth‐order microkinetics with either fully active or not fully active biofilm. The maximal volumetric styrene removal rate was found to be 63 g mpacking material−3 h−1 for an influent pollutant concentration of 0.80 g m−3 and a superficial gas velocity of 245 m h−1. © 2003 Wiley Periodicals, Inc. Biotechnol Bioeng 83: 29–38, 2003.
Multienzyme catalysis in microfluidic biochips
Authors: Lee Moo‐Yeal , Srinivasan Aravind , Ku Bosung , Dordick Jonathan S.
Published: May 2003

The attachment of enzymes to glass microfluidic channels has been achieved using a highly reactive poly(maleic anhydride‐alt‐α‐olefin) (PMA)‐based coating that is supplied to the microchannel in a toluene solution. The PMA reacts with 3‐aminopropyltriethoxysilane groups linked to the glass surface to form a matrix that enables additional maleic anhydride groups to react with free amino groups on enzymes to give a mixed covalent–noncovalent immobilization support. Using a simple T‐channel microfluidic design, with reaction channel dimensions of 200 μm wide (at the center), 15 μm deep, and 30 mm long giving a reaction volume of 90 nL, soybean peroxidase (SBP) was attached at an amount up to 0.6 μg/channel. SBP‐catalyzed oxidation of p‐cresol was performed in aqueous buffer (with 20% [v/v], dimethylformamide) containing H2O2, with microfluidic transport enabled by electroosmotic flow (EOF). Michaelis–Menten kinetics were obtained with Km and Vmax values of 0.98 mM and 0.21 μmol H2O2 converted/mg SBP per minute, respectively. These values are nearly identical to nonimmobilized SBP kinetics in aqueous–DMF solutions in 20‐μL volumes in 384‐well plates and 5‐mL reaction volumes in 20‐mL scintillation vials. These results indicate that SBP displays intrinsically native activity even in the immobilized form at the microscale, and further attests to the mild immobilization conditions afforded by PMA. Bienzymic and trienzymic reactions were also performed in the microfluidic biochip. Specifically, a combined Candida antarctica lipase B–SBP bienzymic system was used to convert tolyl acetate into poly(p‐cresol), and an invertase–glucose oxidase SBP trienzymic system was used to take sucrose and generate H2O2 for SBP‐catalyzed synthesis of poly(p‐cresol). © 2003 Wiley Periodicals, Inc. Biotechnol Bioeng 83: 20–28, 2003.
A novel biphasic extractive membrane bioreactor for minimization of membrane‐attached biofilms
Authors: Splendiani Antonietta , Nicolella Cristiano , Livingston Andrew G.
Published: May 2003

Extractive membrane bioreactor (EMB) systems offer a means of biologically treating wastewaters, but, like other membrane processes, are constrained by their tendency to be fouled by membrane‐attached biofilms (MABs). This study describes a new approach to eradicate MAB formation and accumulation in EMB systems. To this end, an innovative EMB configuration, the biphasic extractive membrane bioreactor (BEMB), has been developed. In BEMB systems, the two main constituents of the EMB process, membrane and bacteria, are kept separated and interact via a suitable recirculating solvent. Nineteen candidate solvents were tested to assess their suitability for BEMB application. Based on the results of the solvent selection, guidelines are provided to screen solvents for BEMB application. BEMB and EMB runs were carried out to demonstrate the effectiveness of BEMB technology in avoiding MAB accumulation and to compare BEMB and EMB performance. A synthetic wastewater containing monochlorobenzene (MCB) was used as a model system. Abiotic BEMB and EMB runs were carried out and used as comparative references for estimating the effect of MAB accumulation on system performance. MAB thickness in the BEMB systems was controlled at 18 μm during 1 month of operation, whereas, in the EMB systems, MAB thickness reached 1250 μm. Analysis of mass transport in EMB and BEMB systems revealed that the high affinity of the permeating molecules for the solvent may contribute to a reduction in shell‐side mass transfer resistance. This reduction of shell‐side mass transfer resistance and the absence of MAB accumulation led to overall mass transfer coefficients of about sevenfold greater (4.5 × 10−5 m s−1) in the BEMB system than in the EMB system (0.6 × 10−5 m s−1). © 2003 Wiley Periodicals, Inc. Biotechnol Bioeng 83: 8–19, 2003.
Large‐scale propagation of a replication‐defective adenovirus vector in stirred‐tank bioreactor PER.C6™ cell culture under sparging conditions
Authors: Xie Liangzhi , Metallo Christian , Warren James , Pilbrough Warren , Peltier Joseph , Zhong Tanya , Pikus Lana , Yancy Amanda , Leung John , Auniņš John G. , Zhou Weichang
Published: May 2003

Large‐scale propagation of replication‐defective adenovirus vectors has not been well studied to date. One of the challenges for efficient propagation at large scale is to overcome the sensitivity of virus infected cells to gas sparging required for oxygenation and CO2 removal. In our initial experiments, it was observed that productivity of an adenovirus vector was significantly reduced under sparging conditions as compared to nonsparged, i.e., surface‐aerated controls in serum‐free cultures. Investigations led to the identification of a buffer containing surfactant (Polysorbate‐80, PS‐80) that was included in the virus seed stock formulation and introduced through virus infection into the culture at a very low concentration as the cause of the reduced virus productivity. This finding was not obvious and trivial, as neither uninfected sparged nor infected nonsparged PER.C6™ cells in serum‐free cultures were affected by the buffer at such a low PS‐80 concentration of 0.00025% (v/v), which is a common component of serum‐free cell culture media. These results strongly suggest that virus‐infected cells behave very differently from uninfected cells under sparging conditions. To mitigate the deleterious effects of sparging, the virus seed stock was prepared in the absence of the buffer containing PS‐80. At the same time, the concentration of Pluronic‐F68 (PF‐68) in the serum‐free medium was increased to 1 g/L, at which cell growth and metabolism were unaffected, even though this measure alone did not result in virus productivity improvement. Only by implementing the two measures together was virus productivity loss completely eliminated under sparging conditions. After demonstration of the process robustness in 2‐L bioreactors, this adenovirus propagation process was successfully scaled up to 250 L in a 300‐L bioreactor under the worst‐case sparging conditions projected for 10,000‐L scale. © 2003 Wiley Periodicals, Inc. Biotechnol Bioeng 83: 45–52, 2003.
Metabolic load of recombinant protein production: Inhibition of cellular capacities for glucose uptake and respiration after induction of a heterologous gene in Escherichia coli
Authors: Neubauer P. , Lin H. Y. , Mathiszik B.
Published: May 2003

The strong expression of recombinant proteins in bacteria affects the primary carbon and energy metabolism resulting in growth inhibition and acetate formation. By applying glucose pulses to fed‐batch fermentations performed for production of a heterologous (α‐glucosidase in Escherichia coli, we show that the induction of the recombinant gene strongly inhibits the maximum specific uptake capacities for glucose and the respiration capacity. The accumulation of glucose in the fermentation medium promotes the growth of plasmid‐free cells. These inhibition effects are well described by including the kinetics of product formation into a recently published dynamic model (Lin et al. [2001] Biotechnol Bioeng 73:349–357). The new model also includes the population characteristics and gives a good fit to the measured data describing growth, production, substrate consumption, by‐product formation, and respiration. © 2003 Wiley Periodicals, Inc. Biotechnol Bioeng 83: 53–64, 2003.
Construction of biofilms with defined internal architecture using dielectrophoresis and flocculation
Authors: Verduzco‐Luque Cynthia E. , Alp Burçak , Stephens Gillian M. , Markx Gerard H.
Published: May 2003

A novel approach was developed for the construction of biofilms with defined internal architecture using AC electrokinetics and flocculation. Artificial structured microbial consortia (ASMC) consisting of localized layered microcolonies of different cell types were formed by sequentially attracting different cell types to high field regions near microelectrodes using dielectrophoresis. Stabilization of the microbial consortia on the electrode surface was achieved by crosslinking the cells using the flocculant polyethyleneimine (PEI). Consortia of Escherichia coli, Micrococcus luteus, and Saccharomyces cerevisiae were made as model systems. Also, more natural consortia were made of the bacteria Pseudomonas putida, Clavibacter michiganense, and Methylobacterium mesophilum, which are found together in consortia during biodegradation of metal‐cutting waste fluids. © 2003 Wiley Periodicals, Inc. Biotechnol Bioeng 83: 39–44, 2003.
The use of dinoflagellate bioluminescence to characterize cell stimulation in bioreactors
Authors: Chen Antony K. , Latz Michael I. , Frangos John A.
Published: May 2003

Bioluminescent dinoflagellates are flow‐sensitive marine organisms that produce light emission almost instantaneously upon stimulation by fluid shear in a shear stress dose‐dependent manner. In the present study we tested the hypothesis that monitoring bioluminescence by suspended dinoflagellates can be used as a tool to characterize cellular response to hydrodynamic forces in agitated bioreactors. Specific studies were performed to determine: (1) impeller configurations with minimum cell activation, (2) correlations of cellular response and an integrated shear factor, and (3) the effect of rapid acceleration in agitation. Results indicated that (1) at a volumetric mass transfer coefficient of 3 × 10−4 s−1, marine impeller configurations were less stimulatory than Rushton configurations, (2) bioluminescence response and a modified volumetric integrated shear factor had an excellent correlation, and (3) rapid acceleration in agitation was highly stimulatory, suggesting a profound effect of temporal gradients in shear in increasing cell stimulation. By using bioluminescence stimulation as an indicator of agitation‐induced cell stimulation and/or damage in microcarrier cultures, the present study allows for the verification of hypotheses and development of novel mechanisms of cell damage in bioreactors. © 2003 Wiley Periodicals, Inc. Biotechnol Bioeng 83: 93–103, 2003.
Metabolic flux and metabolic network analysis of Penicillium chrysogenum using 2D [13C, 1H] COSY NMR measurements and cumulative bondomer simulation
Authors: van Winden Wouter A. , van Gulik Walter M. , Schipper Dick , Verheijen Peter J.T. , Krabben Preben , Vinke Jacobus L. , Heijnen Joseph J.
Published: May 2003

At present two alternative methods are available for analyzing the fluxes in a metabolic network: (1) combining measurements of net conversion rates with a set of metabolite balances including the cofactor balances, or (2) leaving out the cofactor balances and fitting the resulting free fluxes to measured 13C‐labeling data. In this study these two approaches are applied to the fluxes in the glycolysis and pentose phosphate pathway of Penicillium chrysogenum growing on either ammonia or nitrate as the nitrogen source, which is expected to give different pentose phosphate pathway fluxes. The presented flux analyses are based on extensive sets of 2D [13C, 1H] COSY data. A new concept is applied for simulation of this type of 13C‐labeling data: cumulative bondomer modeling. The outcomes of the 13C‐labeling based flux analysis substantially differ from those of the pure metabolite balancing approach. The fluxes that are determined using 13C‐labeling data are shown to be highly dependent on the chosen metabolic network. Extending the traditional nonoxidative pentose phosphate pathway with additional transketolase and transaldolase reactions, extending the glycolysis with a fructose 6‐phosphate aldolase/dihydroxyacetone kinase reaction sequence or adding a phosphoenolpyruvate carboxykinase reaction to the model considerably improves the fit of the measured and the simulated NMR data. The results obtained using the extended version of the nonoxidative pentose phosphate pathway model show that the transketolase and transaldolase reactions need not be assumed reversible to get a good fit of the 13C‐labeling data. Strict statistical testing of the outcomes of 13C‐labeling based flux analysis using realistic measurement errors is demonstrated to be of prime importance for verifying the assumed metabolic model. © 2003 Wiley Periodicals, Inc. Biotechnol Bioeng 83: 75–92, 2003.
Evaluation of spectrofluorometry as a tool for estimation in fed‐batch fermentations
Authors: Hagedorn Andrea , Legge Raymond L. , Budman Hector
Published: May 2003

Native culture fluorescence was investigated as an additional source of information for predicting biomass and glucose concentrations in a fed‐batch fermentation of Alcaligenes eutrophus. Partial least squares (PLS) regression and a feed forward neural network (FFNN) coupled with principle component analysis (PCA) were each used to model the kinetics of the fermentation. Data from three fermentations was combined to form a training set for model calibration and data from a fourth fermentation was used as the testing set. The fluorescent soft‐sensors were compared with a previously developed feed forward neural network soft‐sensor model which used oxygen uptake rate (OUR), carbon dioxide evolution rate (CER), aeration rate, feed rate, and fermentor volume to estimate biomass and glucose concentrations. The best model performance for predicting both biomass and glucose concentrations was achieved using the native fluorescence‐based models. Real data predictions of the biomass concentration in the testing set were obtained using both the PLS and FFNN PCA modeling utilizing fluorescence measurements plus the rate of change of the fluorescence measurements. Accurate predictions of the glucose concentration in the testing set were obtained using the FFNN PCA modeling technique utilizing the rate of change of the fluorescence measurements. Substrate exhaustion was indicated qualitatively by a first‐order PLS model utilizing the rate of change of fluorescence measurements. These results indicate that native culture fluorescence shows promise for providing additional valuable information to enhance predictive modeling which cannot be extracted from other easily acquired measurements. © 2003 Wiley Periodicals, Inc. Biotechnol Bioeng 83: 104–111, 2003.
Fluid shear contributions to bacteria cell detachment initiated by a monoclonal antibody
Authors: Mascari Lisa , Ymele‐Leki Patrick , Eggleton Charles D. , Speziale Pietro , Ross Julia M.
Published: May 2003

Receptor‐mediated adhesion of bacteria to biological surfaces is a significant step leading to infection. Due to an increase in bacterial antibiotic resistance, novel methods to block and disrupt these specific interactions have gained considerable interest as possible therapeutic strategies. Recently, several monoclonal antibodies specific for the Staphylococcus aureus collagen receptor demonstrated specialized ability to displace attached cells from collagen in static assays. In this study, we experimentally examine the monoclonal antibody detachment functionality under physiological shear conditions to evaluate the role of this parameter in the detachment process. The detachment of staphylococci from collagen was quantified in real‐time using a parallel plate flow chamber, phase contrast video‐microscopy and digital image processing. The results demonstrate a unimodal dependence of detachment on fluid wall shear rate. The observed decrease in effective detachment rate with increasing force at the highest shear levels evaluated is counterintuitive and has not been previously demonstrated. Several possible mechanisms of this result are discussed. © 2003 Wiley Periodicals, Inc. Biotechnol Bioeng 83: 65–74, 2003.
Hydrodynamic stress and lethal events in sparged microalgae cultures
Authors: Barbosa Maria J. , Albrecht Marco , Wijffels René H.
Published: May 2003

The effect of high superficial gas velocities in continuous and batch cultures of the strains Dunaliella tertiolecta, Chlamydomonas reinhardtii wild‐type and cell wall‐lacking mutant was studied in bubble columns. No cell damage was found for D. tertiolecta and C. reinhardtii (wild‐type) up to superficial gas velocities of 0.076 and 0.085 m s−1, respectively, suggesting that high superficial gas velocities alone cannot be responsible for cell death and, consequently, bubble bursting cannot be the sole cause for cell injury. A death rate of 0.46 ± 0.08 h−1 was found for C. reinhardtii (cell wall‐lacking mutant) at a superficial gas velocity of 0.076 m s−1, and increased to 1.01 ± 0.29 h−1 on increasing superficial gas velocity to 0.085 m s−1. Shear sensitivity is thus strain‐dependent and to some extent the cell wall plays a role in the protection against hydrodynamic shear. When studying the effect of bubble formation at the sparger in batch cultures of D. tertiolecta by varying the number of nozzles, a death rate of 0.047 ± 0.016 h−1 was obtained at high gas entrance velocities. D. tertiolecta was cultivated in a pilot‐plant reactor under different superficial gas velocities of up to 0.026 m s−1, with relatively low gas entrance velocities and no cell damage was observed. There is some indication that the main parameter causing cell death and damage was the gas entrance velocity at the sparger. © 2003 Wiley Periodicals, Inc. Biotechnol Bioeng 83: 112–120, 2003.
Optimization of catechol production by membrane‐immobilized polyphenol oxidase: A modeling approach
Authors: Boshoff A. , Burton M. H. , Burton S. G.
Published: May 2003

Although previous research has focused on phenol removal efficiencies using polyphenol oxidase in nonimmobilized and immobilized forms, there has been little consideration of the use of polyphenol oxidase in a biotransformation system for the production of catechols. In this study, polyphenol oxidase was successfully immobilized on various synthetic membranes and used to convert phenolic substrates to catechol products. A neural network model was developed and used to model the rates of substrate utilization and catechol production for both nonimmobilized and immobilized polyphenol oxidase. The results indicate that the biotransformation of the phenols to their corresponding catechols was strongly influenced by the immobilization support, resulting in differing yields of catechols. Hydrophilic membranes were found to be the most suitable immobilization supports for catechol production. The successful biocatalytic production of 3‐methylcatechol, 4‐methylcatechol, catechol, and 4‐chlorocatechol is demonstrated. © 2003 Wiley Periodicals, Inc. Biotechnol Bioeng 83: 1–7, 2003.
Enoxaparin effect depends on body-weight and current doses may be inadequate in obese patients
Authors: Frederiksen S G , Hedenbro J L , Norgren L
Published: May 2003

Potential problem highlighted
111In-labelled octreotide binding by the somatostatin receptor subtype 2 in neuroendocrine tumours
Authors: Hashemi S H , Benjegård S-A , Ahlman H , Wängberg B , Forssell-Aronsson E , Billig H , Nilsson O
Published: May 2003

Background

The aim of this study was to investigate the importance of somatostatin receptor subtype 2 (SSTR2) expression for 111In-labelled diethylenetriamine-pentaacetic acid (DTPA)-d-Phe1-octreotide binding and uptake of 111In in neuroendocrine tumours.

Methods

111In activity concentrations in surgical biopsies from neuroendocrine tumours (midgut carcinoid and medullary thyroid carcinoma), breast carcinoma and blood were determined 1–8 days after intravenous injection of 111In-labelled DTPA-d-Phe1-octreotide (140–350 MBq). The ratio of 111In activity concentrations between tumour tissue and blood (T/B value) was calculated. The expression of SSTR2 messenger RNA (mRNA) in tumour biopsies was quantitated by ribonuclease protection assay and SSTR2 protein was localized by immunocytochemistry.

Results

T/B values were highest for tumour biopsies from midgut carcinoids (mean 160 (range 4–1200); n = 65) followed by medullary thyroid carcinoma (mean 38 (range 2–350); n = 88) and breast carcinoma (mean 18 (range 4–41); n = 4). The expression of SSTR2 mRNA (relative to the NCI-H69 cell line) was highest in tumour biopsies from midgut carcinoids (mean 2·5 (range 0·83–6·0); n = 40) followed by medullary thyroid carcinoma (mean 1·3 (range 0·20–6·0); n = 7) and breast carcinoma (mean 0·66 (range 0·29–1·0); n = 9). In tumour biopsies SSTR2 protein was localized exclusively to tumour cells.

Conclusion

Midgut carcinoid tumours showed a much higher level of SSTR2 expression than medullary thyroid carcinoma in accordance with superior tumour imaging by octreotide scintigraphy. The high SSTR2 mRNA values and T/B values observed in midgut carcinoid tumours were positively correlated.
Extrahepatic disease does not contraindicate hepatectomy for colorectal liver metastases
Authors: Elias D , Ouellet J-F , Bellon N , Pignon J-P , Pocard M , Lasser P
Published: May 2003

Background

Extrahepatic disease has always been considered an absolute contraindication to hepatectomy for liver metastases. The present study reports the long-term outcome and prognostic factors of patients undergoing resection of extrahepatic disease simultaneously with hepatectomy for liver metastases.

Methods

From January 1987 to January 2001, 111 (30 per cent) of 376 patients who had hepatectomy for colorectal liver metastases underwent simultaneous resection of extrahepatic disease with curative intent.

Results

Surgery was considered R0 in 77 patients (69 per cent) and palliative (R1 or R2) in 34 patients (31 per cent). The mortality rate was 4 per cent and the morbidity rate 28 per cent. After a median follow-up of 4·9 years, the overall 3- and 5-year survival rates were 38 and 20 per cent respectively. The 5-year overall survival rate of patients with R0 resection only (n = 75) was 29 per cent. The difference in survival between patients with and without extrahepatic disease discovered incidentally at operation was significant, as was the number of liver metastases.

Conclusion

Extrahepatic disease in patients with colorectal cancer who also have liver metastases should no longer be considered an absolute contraindication to hepatectomy. However, the presence of more than five liver metastases and the incidental intraoperative discovery of extrahepatic disease remain contraindications to hepatic resection.
High recurrence rate after atypical resection for pancreatic metastases from renal cell carcinoma
Authors: Bassi C , Butturini G , Falconi M , Sargenti M , Mantovani W , Pederzoli P
Published: May 2003

Background

Pancreatic metastases from renal cell carcinoma are rare but highly resectable. The aim of this study was to review a series of patients with this condition.

Methods

The study involved 22 consecutive patients with histologically proven pancreatic metastases from renal cell cancer.

Results

Seventeen of the 22 patients had surgery. No patient died but eight of the 17 patients had a postoperative complication. Median follow-up was 33 (range 1–96) months. The 24- and 60-month survival probabilities were 0·84 and 0·53 respectively. Five patients who did not undergo surgery had 24- and 60-month survival probabilities of 0·53 and 0·26 respectively. The difference between the two groups was significant (P = 0·040).

Conclusion

Despite the slow development of these secondaries and their well encapsulated morphology, the high rate of recurrence after limited resection suggests that radical resection should be recommended.
Use of transpelvic rectus abdominis musculocutaneous flap for anal cancer salvage surgery
Authors: Tei T M , Stolzenburg T , Buntzen S , Laurberg S , Kjeldsen H
Published: May 2003

Background

Perineal wounds following abdominoperineal resection (APR), for persistent or locally recurrent anal cancer, are associated with poor healing secondary to irradiation therapy. The results of APR combined with a vertical rectus abdominis musculocutaneous (VRAM) flap transposed transpelvically to cover the perineal defect are presented.

Methods

Between 1994 and 2000, 105 patients were diagnosed and treated for anal cancer. Twenty-two (21 per cent) underwent a salvage operation owing to persistent or locally recurrent disease. In eight patients, before 1996, the perineum was closed primarily with serious wound complications in five. In the final 14 patients, primary perineal reconstruction with a VRAM flap was performed.

Results

Median age was 65·5 (range 45–78) years. Median follow-up was 14·5 (range 3–41) months. There were no flap-related complications and primary healing was achieved in all patients. Median hospital stay was 17 (range 14–72) days. There were two major complications related to the laparotomy and abdominal closure.

Conclusion

Combining the salvage operation with a VRAM flap facilitates primary healing after surgical treatment for persistent or locally recurrent anal cancer. A single-stage primary reconstructive procedure is feasible, with an acceptable complication rate and high level of patient satisfaction.
Comparison of transanal stent with defunctioning stoma in low anterior resection for rectal cancer
Authors: Amin A I , Ramalingam T , Sexton R , Heald R J , Leppington-Clarke A , Moran B J
Published: May 2003

Stent is a potential alternative to a stoma
Evidence of the effect of ‘specialization’ on the management, surgical outcome and survival from colorectal cancer in Wessex
Authors: Smith J A E , King P M , Lane R H S , Thompson M R
Published: May 2003

Background

A prospective audit of the management of colorectal cancer was established to investigate factors associated with variation in survival observed within the former Wessex region (population three million).

Methods

Some 5173 patients (4562 surgically treated) with colorectal cancer diagnosed between 1991 and 1994 were followed for 5 years. Details of referral, diagnosis, surgical treatment, postoperative complications and outcomes were collected. The association between surgical outcomes and survival and both case volume and specialization (defined to include membership of the Association of Coloproctology of Great Britain and Ireland) was explored, accounting for variables with prognostic significance.

Results

There was a statistically significant association between high-volume operators (more than 50 operations per year) and specialization. The greatest benefit was observed with respect to specialists versus non-specialists, in terms of a lower postoperative mortality rate (odds ratio 0·67 (95 per cent confidence interval (c.i. 0·53 to 0·84)), lower anastomotic leak rates (odds ratio 0·46 (c.i. 0·31 to 0·66)), higher local recurrence-free survival (hazard ratio 0·56 (0·44 to 0·71)) and better long-term survival (hazard ratio 0·76 (c.i. 0·71 to 0·83)).

Conclusion

There is a stronger association between surgical specialization in coloproctology and beneficial outcome than with high-volume caseloads. This is not entirely accounted for by case-mix or patient population, and is seen following colonic and rectal surgery and among patients with advanced disease.
Day-case laparoscopic Nissen fundoplication
Authors: Bailey M E , Garrett W V , Nisar A , Boyle N H , Slater G H
Published: May 2003

Background

The aim was to assess the acceptability and safety of day-case laparoscopic fundoplication for gastro-oesophageal reflux disease (GORD).

Methods

This prospective study commenced in December 1999 and lasted for 18 months. All patients had proven symptomatic GORD. Inclusion criteria were American Society of Anesthesiologists grade I or II with adequate home support. A standard anaesthetic, analgesic and antiemetic protocol was used. Patients were contacted by telephone on the night of discharge and arrangements were made for a nurse to visit the following day. Postoperative pain and nausea were assessed using visual analogue scores (scale 0–10) on a self-completion questionnaire.

Results

Twenty patients were included. There were no postoperative complications. All patients were discharged on the day of surgery. Median time to discharge was 6 h 30 min (range 4·5 to 9 h). One patient reattended casualty the following morning but none required readmission. There was no significant difference in median pain or nausea scores the evening after surgery or the next morning. All patients were satisfied with the information given and aftercare provided. All would recommend it to a friend and 19 of 20 would undergo the procedure as a day case again.

Conclusion

This study suggests that day-case laparoscopic fundoplication is feasible. Patients find it acceptable and it appears safe.
Pathophysiology of intra-abdominal adhesion and abscess formation, and the effect of hyaluronan
Authors: Reijnen M M P J , Bleichrodt R P , van Goor H
Published: May 2003

Background

Intra-abdominal adhesions and abscesses cause significant morbidity and mortality. The formation of fibrin in the abdominal cavity is a common pathophysiological pathway for both. The aim of this review was to investigate the pathophysiology of intra-abdominal adhesions and abscesses, and to explore the possible sites of action of hyaluronan.

Methods

Data were reviewed from the literature using the Medline database.

Results

Both surgery and peritonitis disturb the equilibrium between coagulation and fibrinolysis in the abdominal cavity in favour of the coagulation system. Hyaluronan-based agents reduce adhesion formation after surgery. Moreover, hyaluronan solution reduces abscess formation in experimental peritonitis. Possible mechanisms of action include mechanical separation of wound surfaces, improvement of peritoneal healing, modulation of the inflammatory response and enhanced fibrinolysis.

Conclusion

Diminished fibrin degradation is a common pathway for the formation of adhesions and abscesses. The potential of hyaluronan-based agents to reduce intra-abdominal adhesions and abscesses in abdominal surgery and sepsis is a promising new concept. Elucidating the mechanisms involved and the clinical application of hyaluronan in peritonitis are challenges for future research.
Ovarian ablation in the adjuvant treatment of premenopausal and perimenopausal breast cancer
Authors: Sainsbury R
Published: May 2003

Background

Ovarian ablation has been employed in the treatment of breast cancer for many decades and, more recently, its value as an adjuvant treatment for premenopausal women with early-stage disease has been clearly demonstrated. This review examines the different methods of achieving ovarian ablation and assesses the relevance of ovarian suppression as a treatment aim.

Methods

Medline searches were used to identify recent key articles relating to the adenoma–carcinoma sequence. Further relevant articles were obtained by manual scanning of the reference lists of selected papers.

Results and conclusion

Ovarian ablation has historically been achieved by surgical or radiological intervention. Although beneficial in premenopausal disease, these methods produce permanent ablation that results in a premature menopause, which may be associated with long-term adverse events. A series of trials have recently demonstrated the benefits of luteinizing hormone releasing hormone (LHRH) agonists, such as goserelin and leuprorelin, as adjuvant treatment for premenopausal hormone-sensitive disease. LHRH agonists produce a reliable suppression of ovarian oestrogen production of equivalent efficacy to adjuvant chemotherapy in hormone-sensitive disease. Effective ovarian suppression is marked by amenorrhoea, but studies have suggested that permanent amenorrhoea is not necessary to confer benefit in the treatment of early breast cancer. LHRH agonists therefore represent a beneficial therapeutic option for premenopausal patients with hormone-sensitive early disease.
Planning eco‐industrial parks: an analysis of Dutch planning methods
Authors: van Leeuwen Marcus G. , Vermeulen Walter J. V. , Glasbergen Pieter
Published: May 2003

In theory, eco‐industrial parks can make significant improvements in the environment. In that light, this article analyses six planning methods currently in use in the Netherlands. The most salient findings are that these methods lack an explicit vision of sustainability, they do not give due consideration to symbiotic or utility‐sharing options, they do not sufficiently engage the companies involved in the development and their policy instruments have a limited environmental impact. The planning methods prove to have many shortcomings: the definition of sustainability is unclear; there are no quantitative standards; information on symbiosis and utility sharing is inadequate; the economic and organizational implications are largely ignored and the environmental impact is insufficiently monitored. However, eco‐industrial parks can only have greater environmental benefits through symbiosis and utility sharing. Therefore, location‐ and company‐specific factors have to be taken into consideration. Copyright © 2003 John Wiley & Sons, Ltd. and ERP Environment
Dynamic change of corporate environmental strategy: rhetoric and reality
Authors: Rhee Seung‐Kyu , Lee Su‐Yol
Published: May 2003

Although rhetoric involves political and symbolic posture, and does not always accurately represent reality, it plays an important role in the dynamic change process of environmental strategy. We first elaborate on the related concepts and develop frameworks to analyze corporate environmental strategy and its change. We report two case studies of Korean companies using the framework. Longitudinal case studies also provide additional implications for corporate environmental strategy in developing countries such as Korea.

There is a gap between the rhetoric and reality of environmental strategy and it constantly changes over time depending on specific internal and external influences. The strength of external influences is a factor that determines whether the change is real or merely rhetorical. Internal organizational variables most likely affect the reality of environmental strategy. We show that the elaboration of rhetorical and realistic aspects of corporate environmentalism can bring out deeper insights and new theoretical developments. Copyright © 2003 John Wiley & Sons, Ltd. and ERP Environment
Tracing business and environmental effects of environmental management systems—a study of networking small and medium‐sized enterprises using a joint environmental management system
Authors: Ammenberg Jonas , Hjelm Olof
Published: May 2003

In Hackefors Industrial District in Sweden, 26 small and medium‐sized enterprises (SMEs) have formed an environmental network and implemented a joint environmental management system (EMS) according to ISO 14001. Based on interviews with the environmental co‐ordinators at these enterprises, the effects on business and environmental efforts and impacts are analysed.

It can be concluded that the joint EMS has resulted in better relations with important stakeholders, such as existing and potential customers. For example, three‐fifths said that their EMS had made it easier to receive a contract for the sale of products and services. Several environmental improvements have been observed and are presented in the paper, many of which are considered as consequences of the EMSs. Moreover, based on observations during the study, this paper discusses how boundaries and screening affect the connection between EMSs and environmental performance. Copyright © 2003 John Wiley & Sons, Ltd. and ERP Environment
Environmental and social disclosure and data richness in the mining industry
Authors: Peck Philip , Sinding Knud
Published: May 2003

Self‐regulation by firms and industries in relation to the environmental impact they cause is not a full substitute for more traditional regulation of environmental externalities. However, some self‐regulatory efforts do involve very specific actions that serve to reduce externalities for a specific industry and certainly achieve more than the presentation of a responsible image to the world. An example of such efforts that go beyond common claims about ‘sustainable activities’ is seen in the increasing numbers of mining firms that generate and issue environmental reports. While there is as yet no indisputable proof that reporting has a direct effect on environmental performance, this paper shows that within a single industry there are wide variations in reporting practices and that sincerity is apparent in the process. Copyright © 2003 John Wiley & Sons, Ltd. and ERP Environment
Compensation systems for green strategy implementation: parametric and non‐parametric approaches
Authors: Lothe Solveig , Myrtveit Ingunn
Published: May 2003

This paper presents a design for compensation systems for green strategy implementation based on parametric and non‐parametric approaches. The purpose of the analysis is to use formal modeling to explain the issues that arise with the multi‐task problem of implementing an environmental strategy in addition to an already existing profit‐oriented strategy. For the first class of compensation systems (parametric), a multi‐task model is used as a basis. For the second class of compensation systems (non‐parametric), data envelopment analysis is applied.Copyright © 2003 John Wiley & Sons, Ltd. and ERP Environment
Identity narratives of Muslim foreign workers in Japan
Authors: Onishi Akiko , Murphy‐Shigematsu Stephen
Published: May 2003

This article examines the identity and acculturation experience of Muslim foreign workers in Japan. The psychological impact of prolonged stay in a foreign country was studied by eliciting narratives of experiences of 24 male foreign workers from Bangladesh, Pakistan, and Iran who had been in Japan more than 5 years. By analysing the narratives they produced, three different styles of stories emerged which explained their experiences and their attempts to maintain or construct a sense of identity.

Accepting the dominant narrative of Japanese society and describing oneself as ‘almost like Japanese’ was one way. Another strategy stressed the rejection of the dominant narrative as well as attempts to maintain the original narrative of the self as educated and active young men. The third narrative showed how individuals re‐defined themselves as Muslim by incorporating religious identity into a central part of their self‐concepts, and asserting its pervasive effect on all aspects of life.

This study provides a perspective for acculturation research focused on social elements of identity, and derived from experiences in a relatively mono‐cultural society recently opening to immigration and in which there is a prevailing ideology of assimilation. Copyright © 2003 John Wiley & Sons, Ltd.
Effect of dexamethasone on neutrophil metabolism
Authors: Garcia Carolina , de Oliveira Marina Costa Xavier , Verlengia Rozangela , Curi Rui , Pithon‐Curi Tania Cristina
Published: May 2003

The effect of dexamethasone on glucose and glutamine metabolism was investigated. The consumption and oxidation of glucose and glutamine, and the production of glutamate and lactate were determined in neutrophils cultured for 3 h in the presence of dexamethasone. The activities and expression of glucose‐6‐phosphate dehydrogenase (G6PDH) and phosphate‐dependent glutaminase were also determined under the same conditions. Addition of dexamethasone to the culture medium caused a significant increase of glucose consumption at 0.5 μm (123.9%) and 1.0 μm (78.3%) concentrations. In spite of this, however, glucose oxidation remained unchanged. The glucocorticoid did not change glutamine consumption but caused a significant increase of glutamate production and did not alter glutamine oxidation. Dexamethasone‐treated neutrophils had a significant decrease of G6PDH activity and expression in particular at 1.0 μm concentration. Phosphate‐ dependent glutaminase activity was also decreased (about 34%) by dexamethasone treatment. A similar effect was observed on glutaminase expression as indicated by RT‐PCR analysis. Thus, the effect of dexamethasone on neutrophil metabolism was particularly noticeable with respect to G6PDH and glutaminase activities where a decrease in the respective mRNA levels was demonstrated. Copyright © 2002 John Wiley & Sons, Ltd.
Chemotactic activity of oligopeptides containing an EWS motif on Tetrahymena pyriformis: the effect of amidation of the C‐terminal residue
Authors: Köhidai László , Bösze Szilvia , Soós Pál , Illyés Eszter , Láng Orsolya , Mák Marianna , Sebestyen Ferenc , Hudecz Ferenc
Published: May 2003

Chemotactic properties of 3–7‐mer peptides containing an EWS motive and their peptide amides synthesized and characterized by us were investigated in Tetrahymena pyriformis GL model. Analysis of the peptide acids shows that SEWS possesses exceptionally strong (660%±21; 430%±18) chemoattractant ability at 10−12 and 10−11 m respectively. The shorter peptide (EWS) possesses chemorepellent activity, while longer peptides display neutral (WSEWS) or moderate chemoattractant (EWSEWS and GEWSEWS) chemotactic ability. Amidation of the C‐terminus can significantly modify the character of peptides: it points to the conclusion that a free α‐COOH group at this position is required for the high efficiency of SEWS, while in the shorter (EWS) and longer peptides (WSEWS and EWSEWS) amidation can result in chemoattractant ligands. Evaluation of the structure–function relationship of these compounds establishes the significance of Glu (E) with its high surface‐exposed area and negatively‐charged side chain. The high discriminative ability and good chemotactic responsiveness of Tetrahymena support the theory that a chemotactic signalling mechanism working in higher levels of phylogeny is a well conserved and inducible one even in protozoa. Copyright © 2002 John Wiley & Sons, Ltd.
Effects of melatonin on oxidative–antioxidative status of tissues in streptozotocin‐induced diabetic rats
Authors: Aksoy Nurten , Vural Hüseyin , Sabuncu Tevfik , Aksoy Sahin
Published: May 2003

In view of the antioxidant properties of melatonin, the effects of melatonin on the oxidative–antioxidative status of tissues affected by diabetes, e.g. liver, heart and kidneys, were investigated in streptozotocin (STZ)‐induced diabetic rats in the present study. Concentrations of malondialdehyde (MDA) and reduced glutathione (GSH), and activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH‐Px) in the tissues were compared in three groups of 10 rats each (control non‐diabetic rats (group I), untreated diabetic rats (group II) and diabetic rats treated with melatonin (group III)). In the study groups, diabetes developed 3 days after intraperitoneal (i.p.) administration of a single 60 mg kg−1 dose of STZ. Thereafter, while the rats in group II received no treatment, the rats in group III began to receive a 10 mg kg−1 i.p. dose of melatonin per day. After 6 weeks, the rats in groups II and III had significantly lower body weights and higher blood glucose levels than the rats in group I (p < 0.001 and p < 0.001, respectively). MDA levels in the liver, kidney and heart of group II rats were higher than that of the control group (p < 0.01, p < 0.05, p < 0.01, respectively) and diabetic rats treated with melatonin (p < 0.05). The GSH, GSH‐Px and SOD levels increased in diabetic rats. Treatment with melatonin changed them to near control values. Our results confirm that diabetes increases oxidative stress in many organs such as liver, kidney and heart and indicate the role of melatonin in combating the oxidative stress via its free radical‐scavenging and antioxidant properties. Copyright © 2002 John Wiley & Sons, Ltd.
Dantrolene protects erythrocytes against oxidative stress during whole‐body irradiation in rats
Authors: Emin Büyükokuroğlu Mehmet , Taysi Seyithan , Koç Mehmet , Bakan Nuri
Published: May 2003

In our study, we examined the radioprotective effects of dantrolene against γ irradiation‐induced damage of blood cells after total body irradiation of rats. Rats were divided into three groups of eight rats each. The first group was the control group receiving no dantrolene or irradiation, the second group received total body irradiation (RT) with 5 Gy of γ irradiation only, and the third group received dantrolene at a dose of 5 mg kg−1 plus RT. Dantrolene was given intraperitoneally 30 min before RT. All groups were sacrificed 2 h after RT, and blood samples were taken. Leukocyte, and thrombocyte counts and hemoglobin levels were measured. Furthermore, malondialdehyde (MDA) levels in plasma and erythrocytes and superoxide dismutase (SOD) and glutathione peroxidase activities (GSH‐Px) in erythrocytes were determined. It was found that pretreatment with dantrolene at a dose of 5 mg kg−1 significantly reduced the MDA levels and increased the antioxidant SOD and GSH‐Px activities, and prevented the decrease in leukocyte and thrombocyte counts. We conclude that dantrolene has clear antioxidant properties when given prior to radiation exposure and the protective effect of dantrolene against damage inflicted by radiation, depends, at least in part, on the decrease in lipid peroxidation and increase in the activity of antioxidant enzymes SOD and GSH‐Px. Copyright © 2003 John Wiley & Sons, Ltd.
Investigation of antioxidant vitamins (A, E and C) and selenium levels in chickens receiving estrogen or testosterone
Authors: Halifeoglu Ihsan , Karatas Fikret , Canatan Halit , Colak Ramiz , Karadas Erkan
Published: May 2003

In the present study estrogen or testosterone was administered to broiler chickens (6 weeks old) for 5 weeks and levels of antioxidant vitamins (A, E and C) and selenium (Se) were determined. In animals who received estrogen, vitamins A, E, C and Se levels were 0.70 ± 0.19, 11.0 ± 2.45, 20.0 ± 5.17 and 130.0 ± 25.0 μg l−1, respectively. Vitamins A, E, C and Se levels in the testosterone‐administered group were found to be 0.54 ± 0.16, 9.9 ± 1.96, 18.0 ± 5.18 and 100.0 ± 18.0 μg l−1, respectively. Vitamins A, E, C and Se levels were found to be significantly increased in the estrogen‐administered group compared to the controls (p < 0.01, p < 0.01, p < 0.05, p < 0.05, respectively). Although all parameters were increased in testosterone‐treated animals, only increases in vitamins A and E were found to be statistically significant (p < 0.01, p < 0.01, respectively). Based on the present findings, estrogen and testosterone show direct antioxidant effects by increasing the activities of some enzymes and they also cause an increase in antioxidant vitamin levels and hence indirectly also contribute to antioxidant capacity. Copyright © 2002 John Wiley & Sons, Ltd.