bluuebunny/crossref_metadata_2025 huggingface dataset:
Preoperative treatment of hepatocellular carcinoma with intra-arterial injection of 131I-labelled lipiodol
Authors: Raoul J-L , Messner M , Boucher E , Bretagne J-F , Campion J-P , Boudjema K
Published: October 2003

Background

Recurrence is common after surgery for hepatocellular carcinoma (HCC).

Methods

The efficacy of, and tolerance to, preoperative intra-arterial injection of 131I-labelled lipiodol was examined in 34 patients with HCC, including 29 with cirrhosis. Twenty-five patients had a single hepatic tumour and the mean(s.d.) tumour size was 5·2(3·7) (range 2–15) cm. The patients received between one and three injections of 131I-labelled lipiodol (60 mCi per injection) before surgery. Operations included 14 liver transplants, 13 minor hepatectomies, six major hepatectomies and one exploratory laparotomy.

Results

There was one complication after lipiodol injection due to acute ischaemia of the small bowel. Three of 34 patients died within 28 days, two after transplantation and one after resection. An objective tumour response (decrease in tumour size) was observed in 19 of 34 patients, and a complete histological response in eight of 34. There was an objective tumour response or major histological necrosis of lesions in 25 of 34 patients. The 5-year survival rate was 48·4(8·0) per cent, 69·0 per cent after transplantation and 36·0 per cent in patients who underwent resection.

Conclusion

This preoperative method appeared to be well tolerated, and provided promising results in terms of macroscopic and microscopic tumour responses.
Population-based study of the surgical workload and economic impact of bowel obstruction caused by postoperative adhesions
Authors: Kössi J , Salminen P , Rantala A , Laato M
Published: October 2003

Background

Intestinal obstruction is the most severe consequence of adhesion formation. This study examined the annual surgical workload and costs of intestinal obstruction caused by postoperative intra-abdominal adhesions.

Methods

The study was a retrospective case-note review of patients hospitalized for intestinal obstruction caused by postoperative adhesions in a well defined geographical area. The surgical workload and direct costs of inpatient care were analysed.

Results

There were 138 admissions for postoperative adhesion-related intestinal obstruction during the study with a total of 1118 inpatient days. The median hospital stay was 4 (range 1–58) days among patients who had non-operative treatment and 11 (range 2–34) days for those who had surgery. Surgery was necessary in 40 patients (29·0 per cent). The mean operating time (time from skin incision to last stitch) and the mean time spent in the operating theatre were 79 and 141 min respectively. The cumulative operating time for the surgical group was 52 h 20 min and the cumulative theatre time was 93 h 44 min. The annual direct hospital cost for postoperative adhesional intestinal obstruction was £181 653 in the district studied and the estimated cost for the whole of Finland was £2 077 796.

Conclusion

This population-based study indicates that the workload and costs associated with bowel obstruction caused by postoperative adhesions are substantial.
Use of a continent colonic conduit for treatment of refractory evacuatory disorder following construction of an electrically stimulated gracilis neoanal sphincter
Authors: Saunders J R , Eccersley A J P , Williams N S
Published: October 2003

Background

This study reports the outcome from the addition of a continent colonic conduit (CCC) to an electrically stimulated gracilis neoanal sphincter in patients with severe evacuatory disorder following formation of a neosphincter for end-stage faecal incontinence.

Methods

One hundred and twenty patients had an electrically stimulated gracilis neoanal sphincter constructed for end-stage faecal incontinence. Seven patients developed severe evacuatory disorders; construction of a CCC was required in six patients and an antegrade continence enema procedure in one.

Results

Median follow-up of the seven patients was 77 (range 6–96) months. Six patients with evacuatory disorders had a successful outcome, defined as continence to solid and liquid stool as well as correction of the evacuatory disorder. A stoma was formed in one patient. Patients who had previously undergone anorectal reconstructive surgery were more likely to develop an evacuatory disorder following construction of an electrically stimulated gracilis neoanal sphincter than patients operated on for other reasons (χ2 = 28·13, 1 d.f., P < 0·001).

Conclusion

Construction of a CCC is a useful technique for the majority of patients with severe evacuatory disorders following the formation of an electrically stimulated gracilis neoanal sphincter, for whom the only alternative would be an end stoma. A CCC may be incorporated with construction of an electrically stimulated gracilis neoanal sphincter in patients at significant risk of postoperative severe evacuatory disorders.
Plasminogen mediates liver regeneration and angiogenesis after experimental partial hepatectomy
Authors: Drixler T A , Vogten J M , Gebbink M F B G , Carmeliet P , Voest E E , Borel Rinkes I H M
Published: October 2003

Background

Plasmin system components are upregulated after partial hepatectomy, but their contribution to surgery-induced hepatic angiogenesis and regeneration is unclear. Liver regeneration and angiogenesis after partial hepatectomy were examined in mice lacking plasminogen or urokinase plasminogen activator (uPA).

Methods

Mice with a single-gene deletion of plasminogen or uPA were subjected to 70 per cent partial hepatectomy. Liver regeneration was measured as relative liver weight and cell proliferation index. Angiogenesis was quantified by determining hepatic microvessel density after staining for sinusoidal endothelial cells.

Results

The liver remnant weight was significantly reduced in mice lacking plasminogen or uPA compared with that in wild-type mice on days 2 and 7 after partial hepatectomy. This correlated with impaired cell proliferation. In wild-type mice, regeneration was accompanied by a significant increase in microvessel density after hepatectomy; this increase was impaired in plasminogen-deficient mice.

Conclusion

Plasminogen and uPA are essential for optimal liver regeneration. In addition, plasminogen appears to be a major determinant in regeneration-associated hepatic angiogenesis.
Prognostic value of preoperative magnetic resonance imaging of the pelvis in rectal cancer
Authors: Martling A , Holm T , Bremmer S , Lindholm J , Cedermark B , Blomqvist L
Published: October 2003

Background

Despite radiotherapy and improved surgical techniques, local recurrence rates after treatment of rectal cancer still vary between 3 and 30 per cent. Tumour involvement of the circumferential resection margin (CRM) predicts a high risk of local recurrence. Magnetic resonance imaging (MRI) allows accurate description of the tumour and its spread within the mesorectum. The aim of this study was to assess the prognostic impact of an involved CRM identified at preoperative MRI in patients with rectal cancer.

Methods

Preoperative MRI was performed in 115 patients with rectal cancer between 1995 and 1999. The images were evaluated retrospectively. The shortest distance from the tumour to the CRM was measured, correlated with patient outcome and compared with histopathological findings.

Results

The risk of any recurrence in patients with or without a tumour-involved margin on MRI was nine of 29 and nine of 57 respectively (P = 0·036). Overall survival at 5 years was 43 and 77 per cent (P = 0·012) respectively. Twenty-four of 30 patients who had an involved CRM on histopathology were correctly identified by MRI.

Conclusion

Patients with a potentially involved CRM identified by MRI had a significantly higher risk of recurrence and cancer-related death. Preoperative MRI may be of prognostic value in rectal cancer and may be used to select patients for neoadjuvant radiochemotherapy and/or more radical surgery.
Removal of two sentinel nodes accurately stages the axilla in breast cancer
Authors: Kennedy R J , Kollias J , Gill P G , Bochner M , Coventry B J , Farshid G
Published: October 2003

Background

Assessment of lymph node status in breast cancer is still necessary for staging. Sentinel lymph node biopsy (SNB) may provide accurate staging with less morbidity than axillary clearance. The aim of this study was to assess the effect of the number of sentinel nodes removed on the false-negative rate.

Methods

Data were collected prospectively from 395 women undergoing SNB for breast cancer, between June 1995 and December 2001. All nodes that were hot and/or blue were removed and analysed.

Results

During this interval 136 patients who had SNB were lymph node positive. The median number of sentinel nodes removed was two (range one to five). The overall false-negative rate of SNB in these women was 7·1 per cent. If only one sentinel node had been removed, the false-negative rate would have been 16·5 per cent. The removal of more than two nodes had no effect on axillary staging in all but two women.

Conclusion

In early breast cancer, when there were multiple sentinel nodes, removal of two sentinel nodes significantly reduced the false-negative rate compared with removal of one node. Removing more than two sentinel nodes did not significantly reduce the false-negative rate further.
Sequential physiology scoring facilitates objective assessment of resuscitation in patients with an intra-abdominal emergency
Authors: O'Dair G N , Leaper D J
Published: October 2003

Background

Patients who present with an intra-abdominal emergency often require urgent surgery. Before surgery a period of resuscitation is undertaken pre-emptively, or to correct any overt physiological derangement. The assessment of response to resuscitation and the decision when to operate is subjective. This study examined the role of sequential physiology scores in assessing the response to resuscitation objectively.

Methods

Sequential physiology scores were recorded in 92 patients with abdominal pathology that subsequently required urgent or emergency surgery. The physiology component of the Physiological and Operative Severity Score for enUmeration of Mortality and morbidity (POSSUM), Acute Physiology And Chronic Health Evaluation (APACHE) II and III, and Simplified Acute Physiology Score (SAPS) II were determined at presentation, during resuscitation and immediately before surgery.

Results

There were 76 survivors;16 patients died. All scoring systems showed an improvement during resuscitation but subsequent deterioration before surgery. The POSSUM, and APACHE II and III physiology scores differentiated more effectively between survivors and patients who died than SAPS II.

Conclusion

Sequential physiology scores may facilitate the assessment of patients' response to resuscitation. Patients who fail to respond to resuscitation when identified may benefit from more expedient surgery.
Abdominal aortic aneurysms in the New Zealand Maori population
Authors: Rossaak J I , Sporle A , Birks C L , van Rij A M
Published: October 2003

Background

Abdominal aortic aneurysm (AAA) is believed to be a rare disease in people of non-European descent. Maori, New Zealand's indigenous people, are thought to originate from South East Asia, so their incidence of AAA might also be expected to be low. The aim was to investigate the incidence and phenotypic factors associated with AAA in the New Zealand Maori population.

Methods

A retrospective study was performed using the audit database of the New Zealand Society of Vascular Surgeons. Age-standardized rates of admission and death were calculated for Maori and non-Maori.

Results

Maori comprised 3·9 per cent of the population who had an AAA repaired, similar to the percentage of the Maori population aged over 65 years. However, the death rate from AAA in Maori was 2·4 times the rate in non-Maori. Maori were younger at diagnosis than non-Maori (65·2 versus 71·8 years; P < 0·001), had more emergency procedures (46·6 versus 30·2 per cent; P = 0·018) and a significantly higher proportion of Maori admissions were for a ruptured aneurysm.

Conclusion

Maori had a higher mortality rate from AAA than non-Maori New Zealanders. Although admission rates between Maori and non-Maori were similar, the earlier age of onset and the increased proportion of ruptured aneurysms may indicate that the disease is more severe in Maori.
Isolated hepatic perfusion with high-dose melphalan for the treatment of colorectal metastasis confined to the liver
Authors: Rothbarth J , Pijl M E J , Vahrmeijer A L , Hartgrink H H , Tijl F G J , Kuppen P J K , Tollenaar R A E M , van de Velde C J H
Published: October 2003

Background

Isolated hepatic perfusion (IHP) involves complete vascular isolation of the liver to allow treatment with doses that would be toxic if delivered systemically. A phase II study of IHP in patients with colorectal metastases confined to the liver was performed.

Methods

Seventy-three patients with irresectable colorectal metastases underwent IHP with high-dose melphalan (200 mg) for 1 h. Toxicity was graded according to the National Cancer Institute Common Toxicity Criteria and tumour response was assessed according to World Health Organization criteria.

Results

Seventy-one patients were perfused according to the protocol. Four patients died within 30 days after IHP, resulting in an operative mortality rate of 5·6 per cent. Sixteen patients (22·5 per cent) experienced grade 3–4 hepatotoxicity 1 week after IHP, which was transient and resolved within 3 months in all patients. The tumour response rate (complete or partial remission) was 59 per cent. Median time to progression was 7·7 (range 2·3–31·4) months. Overall median survival after IHP was 28·8 months with a 3-year survival rate of 37 per cent.

Conclusion

IHP for irresectable colorectal metastases confined to the liver resulted in good response rates and long-term survival in a selected group of patients.
Randomized clinical trial of intermittent pneumatic compression and low molecular weight heparin in trauma
Authors: Ginzburg E , Cohn S M , Lopez J , Jackowski J , Brown M , Hameed S M
Published: October 2003

Background

After trauma, up to 60 per cent of immobilized patients have been reported to develop a silent deep vein thrombosis (DVT). No large, prospective randomized trials have tested the efficacy of intermittent pneumatic compression (IPC) devices in these patients.

Methods

A prospective randomized trial was performed of 442 patients who received thromboprophylaxis using either an IPC device or low molecular weight heparin (LMWH). Duplex imaging was performed on both legs on admission, and was repeated weekly thereafter until discharge, at 30 days or when there was a thrombotic event, whichever occurred first.

Results

There were no significant differences in time spent in intensive care, or the proportion of patients with pelvic fractures, spinal cord or head injuries between the two groups. Six patients (2·7 per cent) developed a DVT in the IPC group and one (0·5 per cent) in the LMWH group (P = 0·122). Pulmonary embolism occurred in one patient in each group. There were 13 minor bleeding episodes (four in the IPC group and nine in the LMWH group) and eight major bleeding episodes (four in each group), none of which required operative intervention.

Conclusion

The low rate of thromboembolic complications and the cost savings suggest that IPC might be used safely and effectively for thromboprophylaxis in trauma patients.
Ileal pouch–vaginal fistula treated by abdominoanal advancement of the ileal pouch
Authors: Zinicola R , Wilkinson K H , Nicholls R J
Published: October 2003

Best approach for high fistulas
Percutaneous transhepatic choledochoscopic removal of intrahepatic stones
Authors: Cheung M-T , Wai S-H , Kwok P C-H
Published: October 2003

Background

Treatment of hepatolithiasis is complex and difficult. With the advent of biliary endoscopy and radiological intervention, percutaneous choledochoscopic removal of intrahepatic stones has become a well established procedure.

Methods

Seventy-nine patients with intrahepatic stones that were removed by percutaneous transhepatic choledochoscopy (PTCS) between 1993 and 2001 were studied retrospectively. The results of the procedure and the long-term outcome of these patients were analysed.

Results

The success rate of choledochoscopic removal of intrahepatic stones was 76·8 per cent. Complications occurred in 17 patients (21·5 per cent). Removal of stones predominantly on the right side was difficult using this method. Cholangitis occurred in about one third of patients within 3–5 years after PTCS. For patients with a stricture, cholangitis recurred gradually over the years of follow-up.

Conclusion

Intrahepatic stricture was the major determinant for the recurrence of stones or symptoms. Hepatic resection should be offered to these patients if the disease is localized in one liver segment or lobe. In other cases, percutaneous choledochoscopy and stricture dilatation is a useful solution, and may reduce further damage to the liver.
Effect of neoadjuvant chemoradiotherapy on angiogenesis in oesophageal cancer
Authors: McDonnell C O , Bouchier-Hayes D J , Toomey D , Foley D , Kay E W , Leen E , Walsh T N
Published: October 2003

Background

Vascular endothelial growth factor (VEGF) levels are raised in the serum of patients with oesophageal carcinoma. The aim of this study was to evaluate the tumour microvasculature and the role of tumour-associated macrophages in VEGF production after neoadjuvant chemoradiotherapy and surgery for oesophageal cancer.

Methods

Sections from 92 consecutively resected oesophageal tumours were stained for VEGF, von Willebrand factor and CD68. Twenty-seven patients received preoperative chemoradiation and 65 underwent surgical excision alone. The cellular source of VEGF was determined by parallel-section staining. Microvessel density and macrophage count were determined for each tumour by means of image analysis software.

Results

There were no significant differences between the two groups in age, sex or tumour type. Local downstaging of disease was evident in most specimens of tumours that had received preoperative chemoradiation. All tumours stained positive for VEGF, including those demonstrating a complete pathological response. Staining of parallel sections confirmed macrophages as the principal source of VEGF. Mean microvessel density was 6·4 per high-power field (h.p.f.) in tumours that received preoperative chemoradiation compared with 5·3 per h.p.f. in those treated by surgery alone (P = 0·130). A significant increase in tumour-associated macrophage infiltration was noted in tumours treated with neoadjuvant chemoradiation (22·1 per h.p.f.) compared with those treated by surgery alone (14·3 per h.p.f.) (P = 0·042).

Conclusion

Preoperative chemoradiation had little effect on the local angiogenic profile of the tumour in patients with oesophageal cancer. Tumour-infiltrating macrophages seem to be the source of persistent VEGF production after chemoradiotherapy and might explain the raised serum levels. Addition of an antiangiogenic agent to this regimen may be worthwhile in patients with oesophageal carcinoma.
Laparoscopic donor nephrectomy
Authors: Handschin A E , Weber M , Demartines N , Clavien P-A
Published: October 2003

Background

Living kidney donation represents an important source of organs for patients with end-stage renal failure. Over the past decade, laparoscopic donor nephrectomy has replaced the conventional open procedure in many transplant centres. Using evidence-based methods, this study examines the current status of laparoscopic donor nephrectomy.

Method

A Medline literature search (PubMed database, 1999–2002) and manual cross-referencing were performed to identify all articles relating to laparoscopic donor nephrectomy. Safety and efficacy criteria were analysed systematically for each study. Studies included were categorized using an evidence-based level grading system.

Results

Of 687 publications, 20 studies with level I–II evidence and 12 with level III evidence were analysed. Only one level I study could be identified. Level I and level II evidence suggests superiority of the laparoscopic approach in regard to postoperative analgesic consumption, hospital stay and return to work. Other safety and efficacy criteria, including donor and recipient outcomes, were similar between the two techniques.

Conclusion

Laparoscopic donor nephrectomy has gained community acceptance by physicians and patients over the past decade. Despite a lack of strong evidence, such as large prospective randomized studies, laparoscopic donor nephrectomy is likely to become the ‘gold standard’ for donor nephrectomy in the near future.
Meta-analysis to determine the incidence of obstetric anal sphincter damage
Authors: Oberwalder M , Connor J , Wexner S D
Published: October 2003

Background

The reported incidence of anal sphincter injury after first (11·5–35·0 per cent) and subsequent (3·4–12·1 per cent) vaginal deliveries varies widely. In addition, the reported incidence of associated faecal incontinence ranges from zero to 68·2 per cent. The aim of this study was to perform a meta-analysis of reported incidences of postpartum anal sphincter defect diagnosed by endoanal ultrasonography (EAUS) and associated incidences of faecal incontinence.

Methods

A Medline search yielded five studies with more than 100 subjects who underwent EAUS after childbirth for evaluation of anal sphincter disruption and who were questioned about symptoms of faecal incontinence, defined as any impairment in flatus and stool control but not including urgency of defaecation. A Bayesian meta-analysis was performed to produce one inference while accounting for potential heterogeneity among the five study populations.

Results

Meta-analysis of 717 vaginal deliveries revealed a 26·9 per cent incidence of anal sphincter defect in primiparous women and an 8·5 per cent incidence of new sphincter defects in multiparous women. Overall, 29·7 per cent of anal sphincter defects were symptomatic. Some 3·4 per cent of women experienced postpartum faecal incontinence without an anal sphincter defect. In a Bayesian calculation, the probability of postpartum faecal incontinence due to a sphincter defect was 76·8–82·8 per cent.

Conclusion

The incidence of occult anal sphincter disruption following vaginal delivery is much higher than commonly estimated. However, at least two-thirds of occult defects are asymptomatic postpartum. The probability of faecal incontinence associated with an anal sphincter defect was 76·8–82·8 per cent.
Determination of the ﬂavone tricin in human plasma by high‐performance liquid chromatography
Authors: Cai Hong , Verschoyle Richard D. , Steward William P. , Gescher Andreas J.
Published: October 2003

Tricin is a ﬂavone constituent of brown rice and rice bran, which interferes potently with the survival of human‐derived breast and colon cancer cells in vitro. A speciﬁc and simple high‐performance liquid chromatographic (HPLC) method was developed for the determination of tricin in human plasma with UV–visible detection. HPLC separation on Hypersil‐BDS C18 (4.6 × 250 mm) was carried out with an isocratic mobile phase of 52% methanol in 0.1 m ammonium acetate, pH 5.10, containing 0.27 mm disodium ethylenediamine tetraacetic acid and detection at 355 nm. The retention times of tricin and quercetin (internal standard) were 14.2 and 7.8 min, respectively. The assay was linear in the range 1–100 µg/mL (r2 ≥ 0.995). Tricin in plasma was efﬁciently extracted with 0.1 m acetic acid in acetone, and the recoveries were in the range 92.6–102.8% (n = 6) with relative standard deviation below 10% for three concentrations of tricin, 5, 10 and 100 µg/mL. The lower limit of quantitation (relative standard deviation <20%) was 1 µg/mL. Copyright © 2003 John Wiley & Sons, Ltd.
An HPLC‐MS method for simultaneous estimation of α,β‐arteether and its metabolite dihydroartemisinin, in rat plasma for application to pharmacokinetic study
Authors: Rajanikanth M. , Madhusudanan K. P. , Gupta R. C.
Published: October 2003

This manuscript reports, the development and validation of a sensitive and selective assay method for simultaneous determination of α,β‐arteether and its metabolite dihydroartemisinin (DHA) in rat plasma by liquid chromatography–mass spectrometry. Chromatographic separations were achieved by gradient elution of the analytes with an initial composition of methanol–potassium acetate buffer (pH 4; 73:27, v/v) to 100% methanol in 3 min and maintained for 5 min on a Spheri‐10, RP18 (100 × 4.6 mm i.d.) column following an RP18 (30 × 4.6 mm i.d.) guard column. The total efﬂuent from the column was split so that one‐tenth was injected into the electrospray LC/MS interface. ESI‐MS analysis was performed using a Micromass Quattro II Triple Quadrupole Mass Spectrometer equipped with an electrospray source. The MS analysis was carried out at cone voltage of 22 V with a scan range of 200–500 Da. The analytes were quantiﬁed from the [M+ K]+ ion chromatograms of α,β‐arteether at m/z 352, DHA at m/z 323, artemisinin at m/z 321 and propyl ether analogue of arteether at m/z 365. Liquid–liquid extractions with a combination of n‐hexane and hexane–ethyl acetate (8:2) were used to isolate α,β‐arteether and DHA from rat plasma. The method was validated and gave good accuracy and precision for the studied domain. Linearity in serum was observed over the range 4.375–70 ng/mL for a‐arteether and 10–160 ng/mL for β‐arteether and DHA. Percentage bias (accuracy) and within‐ and between‐assay precision were well within the acceptable range. This method was applied to study the pharmacokinetics following oral administration of α,β‐arteether (30 mg/kg) in rats. Copyright © 2003 John Wiley & Sons, Ltd.
HPLC investigation of free and bound propofol in human plasma and cerebrospinal ﬂuid
Authors: Dawidowicz Andrzej L. , Kalityński Rafał
Published: October 2003

The paper compares the total propofol concentration in the cerebrospinal ﬂuid (CSF) with the free drug concentration in plasma measured in 35 humans scheduled for elective neurosurgical procedures during propofol anaesthesia. The concentrations of total and free propofol in the blood and CSF samples were measured by means of HPLC using liquid–liquid extraction and ultraﬁltration in the sample preparation procedure. The arterial blood and CSF samples (collected from intraventricular drainage) were taken at the same time. According to the obtained results, the usually expected equality between free drug concentration in plasma and its total concentration in CSF is not valid for propofol: the unbound propofol concentration in plasma is not equal to its total concentration in CSF (p < 0.05). This difference suggests a substantial contribution of active transport in propofol transfer from blood into CSF. Moreover, the paper shows the presence of bound propofol in CSF, which is a novel ﬁnding. Copyright © 2003 John Wiley & Sons, Ltd.
Simple high‐performance liquid chromatographic assay for melphalan in perfusate, rat liver and tumour tissue
Authors: Sparidans Rolf W. , Silvertand Linda , Dost Frits , Rothbarth Joost , Mulder Gerard J. , Schellens Jan H. M. , Beijnen Jos H.
Published: October 2003

A simple, sensitive and selective reversed‐phase liquid chromatographic assay has been developed and validated for the anti‐cancer agent melphalan in perfusate, liver and tumour tissue originating from isolated rat liver perfusion studies. Melphalan was extracted from the matrix using ice‐cold methanol. The drug and the internal standard, propylparaben, were detected using ultraviolet absorbance at 262 nm. The assay has been validated in the 0.05–25 µg/mL range for perfusate; the lower limit of quantiﬁcation (LLQ) is 0.05 µg/mL in perfusate and 0.25 ng/mg in liver and tumour tissues. Accuracies ranged from 89 to 110% and the inter‐assay precisions were all below 15% (20% at the LLQ). Melphalan in a biological matrix has to be processed between 0 and 4°C and is stable under all relevant processing and storage conditions tested. The assay has been exhaustively used in isolated liver perfusion studies with the drug demonstrating its applicability. Copyright © 2003 John Wiley & Sons, Ltd.
Resolution of enantiomers of ketoprofen by HPLC: a review
Authors: Mullangi Ramesh , Yao Ming , Srinivas Nuggehally R.
Published: October 2003

Today, a heightened awareness of the applicability of enantiomers in medicine and clinical practice has been gene‐rated due to the continuous evolvement of the ﬁeld of chirality. In this context, this article provides a review of separation of ketoprofen, an important drug, in a popular class of non‐steroidal anti‐inﬂammatory drugs (i.e. profens). This review highlights various methodologies, logistical considerations for separation and provides an exhaustive list of applications mainly focusing on the pharmacokinetic aspects. Clearly, the application of enantioselective methods for drug racemates paves the way to understand the in vivo behavior of individual enantiomer and hence an opportunity for an alternate and/or better option for treating the disease. Copyright © 2003 John Wiley & Sons, Ltd.
Frameworks for incorporating semantic relationships into object‐oriented database systems
Authors: Halper Michael , Liu Li‐min , Geller James , Perl Yehoshua
Published: October 2003

A semantic relationship is a data modeling construct that connects a pair of classes or categories and has inherent constraints and other functionalities that precisely reflect the characteristics of the specific relationship in an application domain. Examples of semantic relationships include part–whole, ownership, materialization and role‐of. Such relationships are important in the construction of information models for advanced applications, whether one is employing traditional data‐modeling techniques, knowledge‐representation languages or object‐oriented modeling methodologies. This paper focuses on the issue of providing built‐in support for such constructs in the context of object‐oriented database (OODB) systems. Most of the popular object‐oriented modeling approaches include some semantic relationships in their repertoire of data‐modeling primitives. However, commercial OODB systems, which are frequently used as implementation vehicles, tend not to do the same. We will present two frameworks by which a semantic relationship can be incorporated into an existing OODB system. The first only requires that the OODB system support manifest type with respect to its instances. The second assumes that the OODB system has a special kind of metaclass facility. The two frameworks are compared and contrasted. In order to ground our work in existing systems, we show the addition of a part–whole semantic relationship both to the ONTOS DB/Explorer OODB system and the VODAK Model Language. Copyright © 2003 John Wiley & Sons, Ltd.
Performance comparison of checkpoint and recovery protocols
Authors: Paul Himadri Sekhar , Gupta Arobinda , Badrinath R.
Published: October 2003

Checkpoint and rollback recovery is a well‐known technique for providing fault tolerance to long‐running distributed applications. Performance of a checkpoint and recovery protocol depends on the characteristics of the application and the system on which it runs. However, given an application and system environment, there is no easy way to identify which checkpoint and recovery protocol will be most suitable for it. Conventional approaches require implementing the application with all the protocols under consideration, running them on the desired system, and comparing their performances. This process can be very tedious and time consuming. This paper first presents the design and implementation of a simulation environment, distributed process simulation or dPSIM, which enables easy implementation and evaluation of checkpoint and recovery protocols. The tool enables the protocols to be simulated under a wide variety of application, system, and network characteristics. The paper then presents performance evaluation of five checkpoint and recovery protocols. These protocols are implemented and executed in dPSIM under different simulated application, system, and network characteristics. Copyright © 2003 John Wiley & Sons, Ltd.
Modelling three‐dimensional rotating flows in cylindrical‐shaped vessels
Authors: Sujatha K. S. , Webster M. F.
Published: October 2003

This paper reports on a study concerned with the numerical simulation of dough kneading that arises in the food processing industry. The flows considered are in a complex domain setting. Two dough mixers running at various rotation speeds are studied; one with a single stirrer and the other with two stirrers. Stirrers are fixed on the lid of the vessel and the motion is driven by the rotation of the outer vessel. Two different mixer orientations are considered, generating horizontal or vertical‐rotating flow fields. Three‐dimensional numerical simulations are performed on the full flow equations in a cylindrical polar co‐ordinates system, through a finite‐element, semi‐implicit time stepping, Taylor–Galerkin pressure‐correction scheme. The results reflect excellent agreement against the equivalent experimental findings. The motivation for this work is to develop advanced technology to model the kneading of dough. The ultimate target is to predict and adjust the design of dough mixers, so that optimal dough processing may be achieved notably, with reference to local rate‐of‐work input. Copyright © 2003 John Wiley & Sons, Ltd.
URANS computations for an oscillatory non‐isothermal triple‐jet using the k–ε and second moment closure turbulence models
Authors: Nishimura M. , Kimura N.
Published: October 2003

Low Reynolds number turbulence stress and heat flux equation models (LRSFM) have been developed to enhance predictive capabilities. A new method is proposed for providing the wall boundary condition for dissipation rate of turbulent kinetic energy, ε, to improve the model capability upon application of coarse meshes for practical use. The proposed method shows good agreement with accepted correlations and experimental data for flows with various Reynolds and Prandtl numbers including transitional regimes. Also, a mesh width about 5 times or larger than that used in existing models is applicable by using the present boundary condition. The present method thus enhanced computational efficiency in applying the complex turbulence model, LRSFM, to predictions of complicated flows. Unsteady Reynolds averaged Navier–Stokes (URANS) computations are conducted for an oscillatory non‐isothermal quasi‐planar triple‐jet. Comparisons are made between an experiment and predictions with the LRSFM and the standard k–ε model. A water test facility with three vertical jets, the cold in between two hot jets, simulates temperature fluctuations anticipated at the outlet of a liquid metal fast reactor core. The LRSFM shows good agreement with the experiment, with respect to mean profiles and the oscillatory motion of the flow, while the k–ε model under‐predicts the mixing due to the oscillation, such that a transverse mean temperature difference remains far downstream. Copyright © 2003 John Wiley & Sons, Ltd.
Numerical solutions of incompressible Navier–Stokes equations using modified Bernoulli's law
Authors: Shatalov A. , Hafez M.
Published: October 2003

Simulations of incompressible flows are important for many practical applications in aeronautics and beyond, particularly in the high Reynolds number regime. The present formulation is based on Helmholtz velocity decomposition where the velocity is presented as the gradient of a potential plus a rotational component. Substituting in the continuity equation yields a Poisson equation for the potential which is solved with a zero normal derivative at solid surfaces. The momentum equation is used to update the rotational component with no slip/no penetration surface boundary conditions. The pressure is related to the potential function through a special relation which is a generalization of Bernoulli's law, with a viscous term included. Results of calculations for two‐ and three‐dimensional problems prove that the present formulation is a valid approach, with some possible benefits compared to existing methods. Copyright © 2003 John Wiley & Sons, Ltd.
A spatially adaptive linear space‐time finite element solution procedure for incompressible flows with moving domains
Authors: Feng Y. T. , Perić D.
Published: October 2003

A linear solution strategy for the finite element simulation of incompressible fluid flows with moving domains is outlined in the context of a fully Lagrangian space‐time GLS formulation using low‐order elements. This linear solution strategy is achieved by assuming that the incompressibility condition is enforced although it is relaxed in the GLS formulation. The approach has a distinct advantage over the non‐linear Newton–Raphson solution approach in a sense that it can not only significantly reduce the computing costs in terms of computer CPU time and memory requirements but also preserve the solution accuracy if a sufficiently small time‐step size is applied. Its applicability is further demonstrated through a wave propagation and breaking problem. For this type of problems, adaptive re‐meshing techniques are essential to achieve a successful simulation. A mesh adaptive procedure developed earlier for simulation of large deformation solid mechanics problems is appropriately modified and employed in simulation of flows of incompressible fluids with moving domains. Copyright © 2003 John Wiley & Sons, Ltd.
Implicit kinetic schemes for the Euler equations
Authors: Reksoprodjo H. S. R. , Agarwal R. K.
Published: October 2003

Recently, the kinetic schemes, namely the kinetic flux‐vector split (KFVS) scheme and kinetic wave/ particle split (KWPS) scheme, for Euler flows have gained wide recognition for their efficiency and robustness. However, to date, all computations performed with these schemes have employed a time‐explicit formulation. The explicit kinetic schemes severely restrict the time‐step allowed for stability. In this paper, an implicit formulation is derived for both the KFVS and KWPS schemes, and is applied to compute the shock tube and shock structure problems in one‐dimension, and oblique shock reflection from a flat plate and supersonic flow past a blunt‐body in two dimensions. Results are compared with analytical results where available and solutions from explicit formulations. It is shown that implicit formulations retain the efficiency and robustness of their explicit counterparts without the restrictive time step constraints. This results in an increase in computational speed for steady state computations. To the authors' knowledge, this is the first time that the implicit kinetic schemes have been formulated. Copyright © 2003 John Wiley & Sons, Ltd.
A non‐iterative method for boundary‐layer equations—Part II: Two‐dimensional laminar and turbulent flows
Authors: Cebeci Tuncer , Shao Jian Ping
Published: October 2003

A non‐iterative method for non‐linear parabolic partial‐differential equations is described and applied to boundary‐layer equations for two‐dimensional laminar and turbulent flows. Comparison of calculated results indicates that the accuracy of this method is comparable to those obtained with an iterative method. Copyright © 2003 John Wiley & Sons, Ltd.
Eulerian–Lagrangian DNS/LES of particle–turbulence interactions in wall‐bounded flows
Authors: Portela Luís M. , Oliemans René V. A.
Published: October 2003

We developed a code for the direct numerical simulation of particle‐laden turbulent flows, using the Eulerian–Lagrangian point‐particle approach. The code uses a semi‐implicit coupling scheme between the particles and the fluid, and a standard finite‐volume single‐phase solver, which can run either in DNS or LES mode; it can consider either one‐ or two‐way coupling between the particles and the fluid. The code was used to study the dynamics of the particle–turbulence interactions in channel and pipe flows loaded with small, heavy particles. We present some results, from both an instantaneous‐structure perspective (fluid turbulence structures and particle‐concentration patterns), and a statistical perspective (probability distribution functions and correlations). Our results suggest that the near‐wall particle–fluid interaction can be understood in terms of the interaction of the particles with the streamwise vortices. The strong streamwise vortices above the wall are responsible for the elongated streaky patterns that occur both in the deposition and resuspension of the particles. When two‐way coupling is considered, the particles produce a large damping in the intensity of the streamwise vortices, without any significant change in their shape and their size. This damping leads to a weakening of the near‐wall streaky‐pattern, and to a reduction in the accumulation of particles at the wall. Copyright © 2003 John Wiley & Sons, Ltd.
An investigation of liquid film thickness during solutal Marangoni condensation using a laser absorption method: Absorption property and examination of measuring method
Authors: Utaka Yoshio , Nishikawa Tetsuji
Published: November 2003

The objective of the study is to establish a method for measuring the thickness of thin condensates of liquid mixtures using a laser light absorption method during the process of water–ethanol Marangoni dropwise condensation. First, the extinction property of the test material, with unknown properties related to infrared laser light having a wavelength of 3.39µm, was measured. Next, measurements were made of the variations in condensate film thickness after the sweeping of the heat transfer surface by departing drops in the Marangoni dropwise condensation cycle. The precision of this method was investigated on the basis of the extinction coefficient of the test material and the thickness of the liquid film. Results showed that this method provides good precision and is applicable to the measurement of other similar materials. © 2003 Wiley Periodicals, Inc. Heat Trans Asian Res, 32(8): 700–711, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/htj.10124
Evaluation of the fatigue behavior of the resin–dentin bond with the use of different methods
Authors: Frankenberger Roland , Strobel Wolfgang O. , Krämer Norbert , Lohbauer Ulrich , Winterscheidt Jens , Winterscheidt Britta , Petschelt Anselm
Published: October 2003

The clinical performance of directly bonded resin composites is fundamentally dependent on durable adhesion to prevent gap formation over time. The goal of this investigation was to evaluate the effectiveness of various dentin adhesives by means of quasistatic and dynamic dentin bond strengths, and also to determine marginal and internal gap formation after loading in an artificial oral environment. Three hundred thirty human third molars were used within four weeks of extraction. Adhesives used were A.R.T. Bond, OptiBond FL, Scotchbond Multi‐Purpose Plus, Single Bond, Prime & Bond NT, and One Up Bond F for bonding of one resin composite (Z 250). Buccal and lingual aspects of 90 teeth were ground flat to expose dentin, then resin composite cylinders were bonded. Initial bond strengths (n = 10) and adhesive fatigue limits (n = 20) were determined with the use of a shear test apparatus. One hundred eighty conical cavities were prepared into dentin discs and filled with the same materials. After 21 days of storage, initial push‐out bond strengths (n = 10) and adhesive fatigue limits (n = 20) were measured. Sixty molars with MO cavities (n = 10) with margins below the cement–enamel junction were filled. Before and after thermomechanical loading (100,000 × 50 N and 2500 × thermocycling between + 5 and + 55 °C), marginal gap formation and internal adaptation (only after loading) were analyzed under a SEM (× 200). The one‐bottle systems showed higher shear bond strengths when evaluated statically and dynamically. However, cyclic fatigue push‐out bond strengths resulted in higher values for older multistep systems. Marginal and internal gap analysis confirmed the results, in favor of older adhesive systems (p < .05; Mann‐Whitney U test). © 2003 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 67B: 712–721, 2003
Facial nerve regeneration through progesterone‐loaded chitosan prosthesis. A preliminary report
Authors: Chávez‐Delgado M. E. , Mora‐Galindo J. , Gómez‐Pinedo U. , Feria‐Velasco A. , Castro‐Castañeda S. , López‐Dellamary Toral F. A. , Luquin‐De Anda S. , García‐Segura L. M. , García‐Estrada J.
Published: October 2003

Biodegradable nerve guides have represented new treatment alternatives for nerve repairing. They are gradually biodegradable, exert biological effects directly to the injured nerve, and act as drug‐ or cell‐delivery devices. Furthermore, progesterone (PROG) has been demonstrated to promote injured peripheral nerve regeneration. In this study, it was hypothesized that PROG delivered from chitosan prostheses provides better facial nerve regenerative response than chitosan prostheses with no PROG. As there are no reports on the use of the former as nerve‐guide material in the regeneration of injured nerves, this is the main objective of the present work. Chitosan prostheses containing PROG were used to bridge 10‐mm gaps in rabbit facial nerves. The regenerated nerves were evaluated 45 days after implantation in animals with the use of light microscopy and morphometric analysis. Gas chromatography was used in order to quantify PROG content in prosthesis prior to and after implantation in subcutaneous tissue at different periods of up to 60 days. In addition, the prosthesis walls were evaluated with histological techniques in order to assess their integrity and the surrounding tissue reaction. Chitosan prostheses allowed PROG release during the time needed for nerve regeneration. At 45 days myelinated nerve fibers were observed in both the proximal and distal stumps. This parameter and the N ratio were higher in the progesterone‐treated group when compared to that of the vehicle control. Findings indicate that chitosan prostheses were useful in nerve regeneration, acting as a long‐lasting PROG delivery device a faster nerve regeneration. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 67B: 702–711, 2003
Osteoconductive and hemostatic properties of apatite formed on/in agarose gel as a bone‐grafting material
Authors: Tabata Masashi , Shimoda Toru , Sugihara Kazumasa , Ogomi Daisuke , Serizawa Takeshi , Akashi Mitsuru
Published: October 2003

The biologic behavior of hydroxyapatite formed on/in agarose (HA/agarose) gels with the use of a novel alternate soaking process was compared with commercially available Bone Ject (True‐Bone ceramic–collagen combined bone‐graft material, Koken, Japan) as a filler for the tooth‐extraction sockets of six adult monkeys (Macasa fascicularis). After the monkeys' first premolars were extracted, the defects created were replaced with one of the following materials: (a) HA/agarose created by 12 soaking cycles, (b) HA/agarose created by 9 soaking cycles, (c) Bone Ject, and (d) no material implantation (control). The time of hemostasis in each extraction site was estimated, and the samples were then studied histologically. In the controls, the time of hemostasis was about 5 min. The Bone Ject particles were easily washed out by bleeding, and the time of hemostasis was about 15 min. The HA/agarose gel was densely packed into the bony defect. The hemorrhage from the defects stopped within a few seconds after graft placement. This hemostasis was most likely related to the compactibility and adhesiveness of the material. After 12 weeks of implantation, free Bone Ject particles surrounded by inflammatory cells were observed. The bony defect filled with the HA/agarose gels was completely absorbed and replaced by newly formed bone possessing bone marrow. There was no difference in the biologic behavior of HA/agarose gels created by 9 versus 12 soaking cycles. The present study suggests that HA/agarose gels may play an important role as an alternative biodegradable bone‐graft material for autogenous bone in humans. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 67B: 680–688, 2003