bluuebunny/crossref_metadata_2025_split huggingface dataset:
Riboflavin‐ and cobalamin‐mediated biodegradation of chloroform in a methanogenic consortium
Authors: Guerrero‐Barajas Claudia , Field Jim A. 
Published: January 2005

AbstractChloroform (CF) is an important priority pollutant contaminating groundwater. Reductive dechlorination by anaerobic microorganisms is a promising strategy towards the remediation of CF. The objective of this study was to evaluate the use of redox active vitamins as electron shuttles to enhance the anaerobic biodegradation of CF in an unadapted methanogenic consortium not previously exposed to chlorinated compounds. Only negligible degradation of CF was observed in control cultures lacking redox active vitamins. The addition of riboflavin (RF), cyanocobalamin (CNB12), and hydroxycobalamin (HOB12) enabled biodegradation of CF. The reactions were predominantly catalyzed biologically as evidenced by the lack of any CF conversion in heat‐killed controls amended with the cobalamins or minor conversion with RF. In live cultures, significant increases in the rate of CF conversion was observed at substoichiometric molar ratios as low as 0.1 to 0.01 vitamin:CF for RF and CNB12, respectively. At the highest molar vitamin:CF ratios tested of 0.2, the first‐order rate constant of CF degradation was 5.3‐ and 91‐fold higher in RF and CNB12 amended cultures, respectively, compared to the unamended control culture. The distribution of biotransformation products was highly impacted by the type of redox active vitamin utilized. Cultures supplemented with RF provided high yields of dichloromethane (DCM). On the other hand, cobalamins promoted the near complete mineralization of organochlorine in CF to inorganic chloride and lowered the yield of DCM. In cultures where no or little CF bioconversion occurred, prolonged exposure to CF resulted in cell lysis, as evidenced by the release of intracellular chloride. The results taken as a whole suggest that the anaerobic bioremediation of CF‐contaminated sites can greatly be improved with strategies aimed at increasing the concentration of redox active vitamins. © 2005 Wiley Periodicals, Inc.
Effect of oxygen on the Escherichia coli ArcA and FNR regulation systems and metabolic responses
Authors: Shalel Levanon Sagit , San Ka‐Yiu , Bennett George N. 
Published: January 2005

AbstractEscherichia coli has several elaborate sensing mechanisms for response to the availability of oxygen and the presence of other electron acceptors. The adaptive responses are coordinated by a group of global regulators, which include the one‐component Fnr protein, and the two‐component Arc system. To quantitate the contribution of Arc and Fnr‐dependent regulation in catabolism, arcA and fnr mutant strains were constructed using the recently developed lambda derived recombination system. The metabolic activity of wildtype E. coli, an arcA mutant, an fnr mutant, and a double arcA‐fnr mutant, via the fermentative pathways in glucose‐limited cultures and different oxygen concentrations was studied in chemostat cultures at steady state. It was found that the most significant role of ArcA is under microaerobic conditions, while that of FNR is under more strictly anaerobic conditions. The FNR protein is normally inactive during microaerobic conditions. However, our results indicate that in the arcA mutant strain the cells behave as if a higher level of the FNR regulator is in the activated form compared to the wildtype strain during the transition from aerobic to microanaerobic growth. The results show a significant increase in the flux through pyruvate formate lyase (PFL) in the presence of oxygen. The activity of FNR‐regulated pathways in the arcA mutant strain is correlated with the high redox potential obtained under microaerobic growth. © 2005 Wiley Periodicals, Inc.
Use of hepatectomy and splenectomy to treat hepatocellular carcinoma with cirrhotic hypersplenism
Authors: Chen X-P , Wu Z-D , Huang Z-Y , Qiu F-Z 
Published: January 2005

Abstract

Background
The aim of this study was to compare the outcome after simultaneous hepatectomy and splenectomy with that after hepatectomy alone for hepatocellular carcinoma with associated hypersplenism.

Methods
Two hundred and four patients with hepatocellular carcinoma and cirrhotic hypersplenism were divided non-randomly into two groups. Ninety-four underwent simultaneous hepatectomy and splenectomy and 110 underwent hepatectomy alone. White blood cell (WBC) and platelet counts, total serum bilirubin levels, immune function, incidence of complications and 5-year survival rates in the two groups were compared.

Results
WBC and platelet counts, distribution of T cell subsets, and levels of bilirubin, interferon γ and interleukin 2 were different between the two groups after operation. All patients who underwent hepatectomy and splenectomy but only 15·5 per cent of those who had hepatectomy alone completed adjuvant chemotherapy. The 5-year tumour-free survival rate was significantly higher after hepatectomy and splenectomy than after hepatectomy alone (37 versus 27·3 per cent; P = 0·003), although overall survival rates were similar.

Conclusion
Simultaneous hepatectomy and splenectomy was associated with improved 5-year tumour-free survival in patients with hepatocellular carcinoma and hypersplenism.
Sequential cohort study of Dacron® patch closure following carotid endarterectomy
Authors: Ali T , Sabharwal T , Dourado R A , Padayachee T S , Hunt T , Burnand K G 
Published: January 2005

AbstractBackgroundCarotid endarterectomy reduces the risk of stroke and death in patients with severe carotid artery stenosis. This study examined whether the technique used to close the arteriotomy influenced the rate of perioperative transient ischaemic attack (TIA), stroke or death.MethodsA cohort of 236 patients undergoing carotid endarterectomy at a single centre was studied; 117 patients had primary closure of the arteriotomy and 119 patients in a sequential series had closure with a Dacron® patch. A standard endarterectomy with completion intraoperative duplex imaging and digital subtraction angiography was used throughout.ResultsPatch closure was associated with a significant reduction in the 30-day combined death, stroke and TIA rate: 10·3 per cent for primary closure versus 2·5 per cent for patch closure (P = 0·017). The risk of any cerebral event (stroke or TIA) was also significantly reduced (7·7 versus 1·7 per cent; P = 0·033). Residual stenosis on completion angiography was more common after primary closure (24·6 versus 7·4 per cent; P = 0·003).ConclusionDacron® patch closure had a higher technical success rate on completion imaging and was associated with a significant reduction in the risk of perioperative stroke, TIA and death.
Gastrointestinal complications after cardiac surgery
Authors: Andersson B , Nilsson J , Brandt J , Höglund P , Andersson R 
Published: January 2005

AbstractBackgroundGastrointestinal complications after cardiac surgery are often difficult to diagnose, and are associated with high morbidity and mortality rates. The aim of this study was to determine risk factors for these complications.MethodBetween 1996 and 2001 data were collected prospectively from 6119 patients who underwent 6186 cardiac surgical procedures. Data from patients who experienced major gastrointestinal complications were analysed retrospectively by univariate and multivariate analysis.ResultsFifty major gastrointestinal complications were identified in 47 patients (incidence 0·8 per cent). Thirteen of these patients died within 30 days. The most common complication was upper gastrointestinal bleeding (16 patients). Intestinal ischaemia was the most lethal complication (eight of ten patients died). Abdominal surgical operations were performed in 12 patients. Multivariate analysis identified nine variables that independently predicted major gastrointestinal complications: age over 80 years, active smoker, need for preoperative inotropic support, New York Heart Association class III–IV, cardiopulmonary bypass time more than 150 min, postoperative atrial fibrillation, postoperative heart failure, reoperation for bleeding and postoperative vascular complications.ConclusionNine risk factors for the development of major gastrointestinal complications after cardiac surgery were identified. Gastrointestinal complications were often lethal but did not independently predict death within 30 days.
In-contiguity and non-anatomical extension of right hepatic trisectionectomy for liver metastases
Authors: Lodge J P A , Menon K V , Fenwick S W , Prasad K R , Toogood G J 
Published: January 2005

Abstract

Background
In some patients undergoing right hepatic trisectionectomy for metastases, extension of the resection beyond the falciform ligament is necessary to achieve tumour clearance. The aim of the present study was to assess the early and long-term outcomes and hepatic function in patients who underwent extensive liver resection beyond right trisectionectomy.

Methods
Thirty-eight patients who had extension of a right trisectionectomy, either in contiguity (IC) or in a non-anatomical (NA) fashion, for liver metastases were included in the study. In-hospital mortality, hepatic function and other morbidity were recorded. Survival outcomes were analysed for the subgroup of patients with colorectal liver metastases. The clinical risk score described by the Memorial Sloan–Kettering Cancer Center was applied to all patients with colorectal liver metastases.

Results
Sixteen patients had IC resection, 15 NA resection, and seven had both IC and NA procedures. There was one in-hospital death. Hepatic dysfunction was seen in 25 patients and two developed liver failure. Disease-free actuarial 3-year survival was 42 per cent for patients with colorectal liver metastases. Survival was significantly better in patients with a clinical risk score of 3 or less.

Conclusion
Extension of right trisectionectomy for liver metastases was associated with a low risk of death and hepatic failure.
Liver resection for hepatocellular carcinoma in patients with cirrhosis
Authors: Wu C-C , Cheng S-B , Ho W-M , Chen J-T , Liu T-J , P'eng F-K 
Published: January 2005

Abstract

Background
Although liver resection is now a safe procedure, its role for hepatocellular carcinoma (HCC) in patients with cirrhosis remains controversial.

Methods
This study compared the results of liver resection for HCC in patients with cirrhosis over two time intervals. One hundred and sixty-one patients had resection during period 1 (1991–1996) and 265 in period 2 (1997–2002). Early and long-term results after liver resection in the two periods were compared, and clinicopathological characteristics that influenced survival were identified.

Results
Tumour size was smaller, indocyanine green retention rate was higher, patients were older and a greater proportion of patients were asymptomatic in period 2 than period 1. Operative blood loss, need for blood transfusion, operative mortality rate, postoperative hospital stay and total hospital costs were significantly reduced in period 2. The 5-year disease-free survival rates were 28·2 and 33·9 per cent in periods 1 and 2 respectively (P = 0·042), and 5-year overall survival rates were 45·9 and 61·2 per cent (P &lt; 0·001). Multivariate analysis identified serum α-fetoprotein level, need for blood transfusion and Union Internacional Contra la Cancrum tumour node metastasis stage as independent determinants of disease-free and overall survival.

Conclusion
The results of liver resection for HCC in patients with cirrhosis improved over time. Liver resection remains a good treatment option in selected patients with HCC arising from a cirrhotic liver.
Pancreatic trauma in children
Authors: Stringer M D 
Published: January 2005

Abstract

Background
Pancreatic trauma is rare in children, and management strategies are diverse and controversial. The aim of this study was to report the outcome of a consecutive series of children with pancreatic injury seen at a single regional centre over a decade.

Methods
All children under 14 years of age referred with pancreatic injury between January 1995 and June 2004 were reviewed retrospectively.

Results
Nine children (six boys) aged 3–13 years sustained pancreatic injuries: one grade I (minor contusion), two grade II (major contusion without duct injury or tissue loss), five grade III (distal transection and duct injury) and one grade IV (proximal transection). Grade I and II injuries were successfully managed without surgery. The five children with grade III injuries were initially treated without operation, but each developed a large symptomatic pseudocyst that failed to resolve with percutaneous drainage. Four underwent a spleen-sparing distal pancreatectomy and one boy with a transected pancreatic neck was treated by Roux-en-Y jejunostomy drainage. A 6-year-old boy who sustained severe pancreatobiliary trauma (grade IV) was treated by Roux-en-Y drainage. All children made a full recovery.

Conclusion
The management of pancreatic injuries in children should be individualized depending on the site of injury, timing of referral, presence of associated injuries and institutional expertise.
Quality of life after curative or palliative surgical treatment of pancreatic and periampullary carcinoma
Authors: Nieveen van Dijkum E J M , Kuhlmann K F D , Terwee C B , Obertop H , de Haes J C J M , Gouma D J 
Published: January 2005

Abstract

Background
Quality of life (QOL) is an important outcome measure after treatment of pancreatic and periampullary carcinoma. The aim of this prospective longitudinal study was to analyse QOL after surgery for resectable pancreatic or periampullary carcinoma.

Methods
Patients with potentially resectable tumours underwent pancreaticoduodenectomy (n = 72) or a double-bypass procedure (n = 42). They were asked to complete a questionnaire before laparotomy and at 2 weeks, 6 weeks, and 3, 6, 9 and 12 months after surgery. Fifty-nine patients completed a shortened questionnaire on a weekly basis.

Results
There was a temporary decrease in physical and gastrointestinal functioning after pancreaticoduodenectomy. A similar decrease in QOL was observed after double bypass, as well as decreases in mental functioning and overall QOL. Almost all QOL scores returned to preoperative values by about 3 months after surgery, although only briefly so in patients who had a double-bypass procedure. There were no differences between groups in the terminal stages of disease. A rapid decrease on all QOL scales was observed in the last 8 weeks before death.

Conclusion
Surgery for pancreatic and periampullary carcinoma was not associated with irreversible impairment or protracted recovery of QOL. The relatively long plateau phase after recovery supports the argument for surgical treatment, including surgical palliation in selected patients.
Determination of (3S)‐3‐hydroxy quinidine for metabolism screening experiments using direct injection capillary electrophoresis and laser‐induced fluorescence detection
Authors: Bhoopathy S. , Karnes H.T. 
Published: January 2005

AbstractCapillary electrophoresis (CE) has been used with collinear laser‐induced fluorescence detection (LIF) to determine the amount of (3S)‐3‐hydroxy quinidine (3OHQ) formed on direct injection of microsomal incubation mixtures. 3OHQ is the CYP 3A4 metabolite of quinidine sulfate (QS) and is therefore useful for metabolism screening studies. The method was validated analytically and tested for its capability of screening for a weak inhibitor of the CYP 3A4 isozyme. A linear calibration was found to provide the best fit for the standard curve with a correlation of 0.9950 and all concentration residuals less than 15%. The percentage relative standard deviations (RSDs) of two controls, 175 and 2250 ng/mL, were 9.29 and 5.68% and the percentage differences from normal (DFN) were 6.87 and −4.37%, respectively. The concentration limit of detection (LOD) for 3OHQ in the incubation matrix was 52.11 ng/mL and the mass LOD was ∼521.1 fg (injection volume 10 nL). The effectiveness of the method to screen for the weak inhibitor erythromycin has been shown by calculating percentage inhibition when incubating with different concentrations of QS. Sensitive detection coupled with the convenience of the direct injection technique makes this an attractive approach for metabolism screening. The small sample size capability of CE will further reduce the quantities of probe drug, microsomes and other reagents required for incubation studies. Copyright © 2001 John Wiley & Sons, Ltd.
Development of a chromatographic method for the determination of saquinavir in plasma samples of HIV patients
Authors: Campanero M. A. , Escolar M. , Arangoa M. A. , Sádaba B. , Azanza J. R. 
Published: January 2005

AbstractA simple, sensitive and reproducible high‐performance liquid chromatographic method for detecting and quantifying saquinavir in human plasma is described. Verapamil was used as internal standard. The method employes a single liquid–liquid extraction step with tert‐butil methyl ether followed by chromatography on a Lichrospher 60 Select B C8 reversed‐phase column. Ultraviolet detection was used to identify the compounds of interest. The quantitation limit of saquinavir was 1 ng/mL and only 0.5 mL of plasma sample was required for the determination. The average saquinavir recoveries over a concentration range of 2.5–5000 ng/mL ranged from 86 to 95%. Precision and accuracy did not exceed 5%. Copyright © 2001 John Wiley & Sons, Ltd.
The determination of biperiden in plasma using gas chromatography mass spectrometry: pharmacokinetics after intramuscular administration to guinea pigs†
Authors: Capacio B. R. , Caro S. T. , Smith J. R. , Byers C. E. 
Published: January 2005

AbstractA gas chromatographic–mass spectrometric (GC‐MS) method has been developed for the analysis of the biperiden from plasma. The method utilizes 290 µl of plasma and a simple hexane extraction/clean‐up procedure. Standard curves were linear over the range of 1.9–250 ng/mL. The range of correlation coefficients for the individual standard curves was 0.9984–0.9999; the largest coefficient of variation expressed as a percentage (%CV) was 11.5%. Precision and accuracy were examined by assessing between‐day and within‐day variability. For between‐day precision, the %CVs ranged from 2.86 to 5.17%. Accuracy as expressed by percentage error ranging from −2.16 to 5.83%. The study for within‐day precision demonstrated %CVs from 0.95 to 5.55% with accuracy from −3.37 to 2.45%. Applicability of the method was demonstrated by examining the pharmacokinetics of intramuscular (i.m.) biperiden as an anticonvulsant treatment in a guinea pig model for organophosphate (OP)‐induced seizure activity. Mean pharmacokinetic parameter estimates were similar to literature values; selected mean pharmacokinetic parameter estimates were: apparent volume of distribution, 13.9 L/kg; half‐life of elimination, 93 min; time to maximal plasma concentration, 27.4 min; and maximal plasma concentration, 32.22 ηg/mL. The time to maximal plasma concentration was found to be similar to the onset time for terminating OP‐induced seizure activity in guinea pigs receiving biperiden as an anticonvulsant treatment. The studies indicate that the method affords the required precision, accuracy and sensitivity to assay biperiden at the doses utilized for these pharmacokinetic studies after i.m. administration to guinea pigs. Copyright © 2001 John Wiley & Sons, Ltd.
Abbreviations used:

AChE

Acetylcholinesterase

AUC

area under the curve

OP

organophosphate

2‐PAM

pralidoxime chloride

PYR

pyridostigmine
Concentration of chosen oxycholesterols in plasma of pregnant women with pregnancy‐induced hypertension
Authors: Bodzek Piotr , Janoszka Beata , Wielkoszyński Tomasz , Bodzek Danuta , Sieroń Aleksander 
Published: January 2005

AbstractSolid‐phase extraction (SPE) was applied for isolation of oxycholesterols from plasma lipid extract from pregnant women with hypertension and from a control group. Separation of oxycholesterols fraction was performed in an SD II horizontal chamber (Chromdes, Poland) using silica gel and octadecyl RPC18 silica gel TLC plates (Merck and Machery Nagel). Visualization was carried out under UV light after Liebermann–Burchard reaction specific for cholesterol and its derivatives. The oxycholesterols (5‐cholestene‐3β‐ol‐7‐one, sum of 5‐cholestene‐3β, 7β‐diol and 5‐cholestene‐3β, 7α‐diol and sum of 5α,6α‐epoxycholestan‐3β‐ol and 5β,6β‐epoxycholestan‐3β‐ol) were quantified by chromatograms scanning in reflectance and fluorescence mode using a CS 9301 densitometer (Shimadzu). The total concentration of the investigated oxycholesterols in the plasma of pregnant women was up to 5000 ng/mL and was statistically significantly higher in women with pregnancy induced hypertension (PIH). Copyright © 2001 John Wiley & Sons, Ltd.
Investigation of the pharmacokinetics of celecoxib by liquid chromatography–mass spectrometry
Authors: Werner Ulrike , Werner Dierk , Pahl Andreas , Mundkowski Ralf , Gillich Martin , Brune Kay 
Published: January 2005

AbstractA new method for the quantification of celecoxib in human plasma based on reversed‐phase high‐performance liquid chromatography (HPLC) coupled to atmospheric pressure chemical ionization (APCI) mass spectrometry (MS) after liquid–liquid extraction is presented. The method is rapid, sensitive and highly selective. The retention time of celecoxib was 2.3 min. The limit of quantification was 5 µg/L. Rofecoxib was used as internal standard. After validation, the method was used to study the pharmacokinetic profile of celecoxib following administration of a single oral dose (200 mg) in 12 healthy volunteers. Since celecoxib should be metabolized primarily by cytochrome 2C9 (CYP2C9), a poor metabolizer (PM) for this cytochrome P450 enzyme was included in the study. Pharmacokinetic characteristics (mean ± SD) of extensive metabolizers (EM) were tmax 2.9 ± 1.2 h, cmax 842 ± 280 µg/L, AUC∞ 6246 ± 2147 µg h/L and t1/2 7.8 ± 2.7 h. The area under the curve (AUC∞) for the PM was 12561 µg h/L. However, we found no noticeable increase in half life in the PM (11.5 h) after a single dose of celecoxib. Copyright­© 2001 John Wiley & Sons, Ltd.
Evaluation and application of liquid chromatographic columns coated with ‘intelligent’ ligands. II. Phospholipid column
Authors: Kamimori Hiroshi , Konishi Masaharu 
Published: January 2005

AbstractThe stationary phases of octadecylsilica (ODS) coated with phospholipid have been developed as a model of artificial lipid membranes for liquid chromatographic columns. An ODS column coated with phospholipid can be readily prepared by recycling a solution containing L‐α‐dipalmitoyl‐phosphatidylcholine (DPPC) through an ODS column in a closed loop. DPPC becomes absorbed on the ODS surfaces by hydrophobic interaction between the acyl group of DPPC and the octadecyl group of the ODS surfaces. The DPPC column was usable when a mobile phase containing 30% (v/v) acetonitrile was delivered without detachment of the DPPC from the ODS surfaces. The retention behavior of ionic solutes on the DPPC column suggested that the retention was based on both ionic and electrostatic interactions between the solutes and the stationary phase. The retention factors on the DPPC column correlated well with the partition coefficients in liposome systems for α‐adrenoceptor agonists and β‐blockers, indicating that the partition of solutes between the coated phase and buffer was similar to that in the liposome/water system. The DPPC column can be used in screening studies to predict the binding properties of drugs onto lipid membranes. Copyright © 2001 John Wiley & Sons, Ltd.