bluuebunny/crossref_metadata_2025 huggingface dataset:
Coexistence of a sulphate‐reducing Desulfovibrio species and the dehalorespiring Desulfitobacterium frappieri TCE1 in defined chemostat cultures grown with various combinations of sulphate and tetrachloroethene
Authors: Drzyzga Oliver , Gerritse Jan , Dijk John A. , Elissen Hellen , Gottschal Jan C.
Published: March 2003

A two‐member co‐culture consisting of the dehalorespiring Desulfitobacterium frappieri TCE1 and the sulphate‐reducing Desulfovibrio sp. strain SULF1 was obtained via anaerobic enrichment from soil contaminated with tetrachloroethene (PCE). In this co‐culture, PCE dechlorination to cis‐dichloroethene was due to the activity of the dehalorespiring bacterium only. Chemostat experiments with lactate as the primary electron donor for both strains along with varying sulphate and PCE concentrations showed that the sulphate‐reducing strain outnumbered the dehalogenating strain at relatively high ratios of sulphate/PCE. Stable co‐cultures with both organisms present at similar cell densities were observed when both electron acceptors were supplied in the reservoir medium in nearly equimolar amounts. In the presence of low sulphate/PCE ratios, the Desulfitobacterium sp. became the numerically dominant strain within the chemostat co‐culture. Surprisingly, in the absence of sulphate, strain SULF1 did not disappear completely from the co‐culture despite the fact that there was no electron acceptor provided with the medium to be used by this sulphate reducer. Therefore, we propose a syntrophic association between the sulphate‐reducing and the dehalorespiring bacteria via interspecies hydrogen transfer. The sulphate reducer was able to sustain growth in the chemostat co‐culture by fermenting lactate and using the dehalogenating bacterium as a ‘biological electron acceptor’. This is the first report describing growth of a sulphate‐reducing bacterium in a defined two‐member continuous culture by syntrophically coupling the electron and hydrogen transfer to a dehalorespiring bacterium.
Contrasting bacterioplankton community composition and seasonal dynamics in two neighbouring hypertrophic freshwater lakes
Authors: Van der Gucht K. , Sabbe K. , De Meester L. , Vloemans N. , Zwart G. , Gillis M. , Vyverman W.
Published: March 2003

We characterized the bacterioplankton community and its seasonal dynamics in two neighbouring hypertrophic lakes by denaturing gradient gel electrophoresis (DGGE) analysis of short (193 bp) 16S ribosomal DNA polymerase chain reaction (PCR) products obtained with primers specific for the domain Bacteria. Lake Blankaart is turbid and has a high phytoplankton biomass and episodic cyanobacterial blooms, whereas biomanipulated Lake Visvijver is characterized by clearwater conditions and the establishment of a dense charophyte vegetation. Both lakes were dominated by bacterial groups commonly found in freshwater habitats (e.g. ACK4 cluster of Actinomycetes; ACK stands for clones isolated from the Adirondack mountain lakes). Yet, cluster analysis and principal components analysis (PCA) revealed that taxon composition of the bacterioplankton community of the two lakes differs substantially and consistently throughout the season. During the study year (1998), the bacterioplankton community of both lakes showed a distinct seasonal pattern. Lake Blankaart showed a clear differentiation between winter, spring, summer and autumn. In Lake Visvijver, summer samples differed greatly from spring, autumn and winter samples. We hypothesize that the contrasting bacterioplankton in the two neighbouring shallow lakes is determined largely by the presence or absence of macrophytes.
Deciphering the action of aromatic effectors on the prokaryotic enhancer‐binding protein XylR: a structural model of its N‐terminal domain
Authors: Devos D. , Garmendia J. , Lorenzo V. de , Valencia A
Published: March 2003

The prokaryotic enhancer‐binding protein XylR is the central regulator of the toluene degradation pathway in Pseudomonas species. Copious genetic and biochemical data indicate that the N‐terminal domain of the protein (domain A) interacts directly with m‐xylene, which renders the protein competent as a transcriptional activator. Single‐site and shuffling mutants of XylR or homologues have been reported to change or expand their effector profiles. Here, we follow a fold recognition approach to generate three‐dimensional models of the domain A of XylR and DmpR with the purpose of deciphering the molecular activity of this protein family. The model is based on the crystallographic data of the rat catechol O‐methyltransferase, a typical α/β fold, consisting of eight α‐helices and seven β‐strands. The fold identification is supported by physico‐chemical properties of conserved amino acids, distribution of residues characteristic of the sequence families and confrontation with experimental data. The model not only provides a rationale for understanding published experimental data, but also suggests the molecular mechanism of the activation step and is a potentially useful conceptual tool for designing regulators with predefined inducer specificities.
Substrate‐regulated cyanide hydratase (chy) gene expression in Fusarium solani: the potential of a transcription‐based assay for monitoring the biotransformation of cyanide complexes
Authors: Barclay M. , Day J. C. , Thompson I. P. , Knowles C. J. , Bailey M. J.
Published: March 2003

The fungus Fusarium solani detoxifies cyanide through induction of the cyanide
hydratase gene activity (chy) in the presence of either KCN or the metal‐complexed
cyanides, K2Ni(CN)4 or K4Fe(CN)6, at
pH 7.0 and 4.0 respectively. Sequence analysis of the chy gene identified
primers for reverse transcriptase–polymerase chain reaction (RT–PCR)‐directed
analysis of mRNA transcripts, which demonstrated that activity correlated to the
substrate‐specific induction of gene expression. chy transcription was initiated
30–60 min after exposure of F. solani cultures to cyanide complexes.
Maximum expression was detected within 4.5 h, after which chy mRNA synthesis
declined below the limits of detection within 26 h. A lag period of ≈ 2
h, following initial transcription, was recorded before cyanide complexes were converted
to formamide. mRNA transcripts of chy were not detected in the absence of
cyanide or cyanide complexes. The presence of introns within the gene resulted in
a difference in size of 100 bp for DNA compared with mRNA of the corresponding 5′
region. This size difference facilitated PCR detection of gene and transcript respectively.
Comparisons of the predicted amino acid sequence of the F. solani chy gene
and those of Gloeocerospora sorghi, Fusarium lateritium and Leptosphaeria
maculans demonstrate that cyanide hydratase genes are highly conserved and of
a similar evolutionary origin. These data predict that the functional assay described
here to monitor the induction of chy gene expression and, potentially, cyanide degradation would be applicable to a variety of polluted environments.
Structure–function studies of the recombinant protein bioemulsifier AlnA
Authors: Toren Amir , Segal Gil , Ron Eliora Z. , Rosenberg Eugene
Published: March 2003

Acinetobacter radioresistens KA53 produces an extracellular bioemulsifier,
referred to as alasan. The surface active component of alasan is a 35.77 kDa protein
AlnA. Although AlnA and the Escherichia coli outer membrane protein A (OmpA)
have a high amino acid sequence homology, E. coli OmpA has no emulsifying
activity. Comparison of the amino acid sequences of AlnA and E. coli OmpA
revealed four hydrophobic regions in AlnA that were absent in E. coli OmpA. Deletions and substitutions (with the homologous OmpA sequence) were constructed in each of the four hydrophobic regions of AlnA by site‐directed polymerase chain reaction (PCR) mutagenesis, using the overlap PCR method. Analysis of the emulsifying activities of the mutated AlnA molecules demonstrated that all four hydrophobic regions were necessary for emulsifying activity. However, most of the inactive mutated proteins still adhered avidly to hexadecane. These findings indicate that in addition to binding to hydrocarbons, the protein emulsifier must form a specific structure on the surface of the hydrocarbon that prevents coalescence of oil droplets. This is the first structure–function study of a protein bioemulsifer.
Is bioconvection enhancing bacterial growth in quiescent environments?
Authors: Jánosi Imre M. , Czirók András , Silhavy Dániel , Holczinger András
Published: March 2003

Bioconvection is an intriguing pattern‐forming phenomenon driven by the swimming activity of various aquatic microorganisms. It is generally assumed that bioconvection has a positive effect on the entire microbial population by carrying oxygen into deep layers of non‐aerated suspensions. In order to examine the presence of such a biological benefit, we analysed the correlation between bioconvective pattern formation and population growth of several Bacillus subtilis and Bacillus licheniformis strains under non‐aerated conditions. Bioconvection is a robust phenomenon, we observed its development in numerous cultures of various strains and growth phases. Nevertheless, evaluation of the data has not revealed detectable positive effects on population growth, questioning the potential biological relevance of bioconvection in natural habitats.
Synchronized expression of ftsZ in natural Prochlorococcus populations of the Red Sea
Authors: Holtzendorff Julia , Marie Dominique , Post Anton F. , Partensky Frédéric , Rivlin Assaf , Hess Wolfgang R.
Published: March 2003

The expression of ftsZ, encoding the initiating protein of the prokaryotic cell division was analysed in natural Prochlorococcus populations in the Gulf of Aqaba, northern Red Sea. During the seasonal Prochlorococcus bloom in September 2000, picoplankton was collected from the deep chlorophyll maximum (DCM) at 2–4 h intervals over 3 consecutive days. Flow cytometric measurements as well as DNA sequence analyses showed that Prochlorococcus was the dominant photosynthetic organism. Cell densities peaked as high as 1.4 × 105 cells ml−1. This DCM population mainly consisted of brightly red fluorescing Prochlorococcus cells, corresponding to low light‐adapted ‘ecotypes’ (sensu Moore et al., 1998, Nature 393: 464–467). Prochlorococcus populations grew in a highly synchronized fashion with DNA replication in the afternoon and cell division during the night. The ftsZ mRNA level reached maximum values within the replication phase between 14.00 and 16.00 hours, and minimum values between 02.00 and 06.00 hours. Thus, the transcriptional regulation of ftsZ could be a major factor triggering the synchronized cell division of Prochlorococcus populations. This is the first application of quantitative reverse transcriptase‐coupled real‐time polymerase chain reaction (PCR) to natural populations of an environmentally relevant marine organism.
Streptomycin‐resistant (rpsL) or rifampicin‐resistant (rpoB) mutation in Pseudomonas putida KH146‐2 confers enhanced tolerance to organic chemicals
Authors: Hosokawa Keiichi , Park Nyun‐Ho , Inaoka Takashi , Itoh Yoshifumi , Ochi Kozo
Published: March 2003

We found that certain Str‐, Gen‐ or Rif‐ mutants derived from Pseudomonas putida KH146‐2, which are resistant to streptomycin, gentamicin or rifampicin, respectively, are tolerant to the aromatic compound 4‐hydroxybenzoate (4HBA). The minimum inhibitory concentration (MIC) of 4HBA as the sole carbon source for the wild‐type strain was 1%, whereas the MIC for the mutants was 1.7%. Frequency of 4HBA‐tolerant mutants among spontaneous Str‐, Gen‐ and Rif‐ mutants was 5–15%, 3–5%, and 3% respectively. These 4HBA‐tolerant mutants also tolerated to a variety of organic chemicals such as 3‐hydroxybenzoate, aliphatic and heterocyclic compounds, chlorobenzoates, as well as organic solvents toluene and m‐xylene. The Str mutants had a point mutation in the rpsL gene, which produces the ribosomal protein S12. The Rif mutants were found to have a point mutation in the rpoB gene, which encodes the RNA polymerase β‐subunit. Mutation points in Gen mutants still remain unknown. Str‐, Gen‐ and Rif‐phenotypes occurred in spontaneous 4HBA‐tolerant mutants which had been selected by successively increasing concentrations (from 0.8% to 5%) of 4HBA. Complementation experiments with one of the Str mutants demonstrated a causal relationship between a rpsL mutation (str‐1) and 4HBA tolerance. Uptake experiments using [14C]‐4HBA revealed that apparent ability of 4HBA to be taken up by the membrane transport system was reduced two to threefold in the mutants compared to the wild‐type strain, accounting at least partly for the enhanced tolerance to 4HBA. Our approaches thus could be effective in improvement of tolerance to aromatic compounds of bacteria applicable for bioremediation.
Fluorescence in situ hybridization of 16S rRNA gene clones (Clone‐FISH) for probe validation and screening of clone libraries
Authors: Schramm Andreas , Fuchs Bernhard M. , Nielsen Jeppe L. , Tonolla Mauro , Stahl David A.
Published: March 2003

A method is presented for fluorescence in situ hybridization (FISH) of 16S rRNA gene clones targeting in vivo transcribed plasmid inserts (Clone‐FISH). Several different cloning approaches and treatments to generate target‐rRNA in the clones were compared. Highest signal intensities of Clone‐FISH were obtained using plasmids with a T7 RNA polymerase promoter and host cells with an IPTG‐inducible T7 RNA polymerase. Combined IPTG‐induction and chloramphenicol treatment of those clones resulted in FISH signals up to 2.8‐fold higher than signals of FISH with probe EUB338 to cells of Escherichia coli. Probe dissociation curves for three oligonucleotide probes were compared for reference cells containing native (FISH) or cloned (Clone‐FISH) target sequences. Melting behaviour and calculated Td values were virtually identical for clones and cells, providing a format to use 16S rRNA gene clones instead of pure cultures for probe validation and optimization of hybridization conditions. The optimized Clone‐FISH protocol was also used to screen an environmental clone library for insert sequences of interest. In this application format, 13 out of 82 clones examined were identified to contain sulphate‐reducing bacterial rRNA genes. In summary, Clone‐FISH is a simple and fast technique, compatible with a wide variety of cloning vectors and hosts, that should have general utility for probe validation and screening of clone libraries.
Ecology of mixed biofilms subjected daily to a chlorinated alkaline solution: spatial distribution of bacterial species suggests a protective effect of one species to another
Authors: Leriche V. , Briandet R. , Carpentier B.
Published: March 2003

Three bacterial strains (Kocuria sp. C714.1, Brevibacterium linens B337.1 and Staphylococcus sciuri CCL101) were grown together on stainless steel and were subjected daily to a commercial alkaline chlorine solution (22 mg l−1 of free chlorine, pH 11) over a period of 4 weeks. After the daily chemical shock, culture madia [1:20 dilution of tryptic soy broth (TSB‐YE/20) or diluted whey] was deposited on the biofilms. The chemical shocks led first to a drop in the culturable population, followed by an increase and finally stabilization at around 106−107 CFU cm−2 by day 11 of the experiment. These changes in the microbial population can be attributed to a decreasing susceptibility to the antimicrobial agent with biofilm age, and to the consumption of free chlorine by biofilm exoproteins. The microbial composition appeared to be linked to the free chlorine concentration that depended on exoprotein production. At the end of the experiment, exoprotein production was greater for biofilms grown in TSBYE/20 than in whey. As a consequence, biofilms grown in whey did not neutralize the chlorine and the dominant strain was the one having the highest resistance to chlorine: K. varians. When biofilm were grown in TSBYE/20, chlorine was neutralized and the dominant strain was the one having the highest growth rate: S. sciuri. The presence of chlorine may also explain the distribution of S. sciuri cells as a ring around Kocuria sp. microcolonies. When chlorine was totally consumed by the biofilm during the chemical shock, S. sciuri was no longer grouped around Kocuria sp. microcolonies but was evenly scattered over the substratum as single cells or in small clusters, as it was before any chemical treatment. These findings strongly suggest protection of S. sciuri by Kocuria sp. microcolonies against the chlorinated solution. This phenomenon, added to the low susceptibility phenotype of the biofilm cells, could at least partly explain the survival of microbial cells in an adverse environment.
Molecular diversity among marine picophytoplankton as revealed by psbA analyses
Authors: Zeidner Gil , Preston Christina M. , Delong Edward F. , Massana Ramon , Post Anton F. , Scanlan David J. , Béjà Oded
Published: March 2003

Photosynthetic microorganisms play a crucial role in the marine environment. In vast areas of the oceans, marine primary productivity is performed by cells smaller than 2–3 µm (picoplankton). Here, we report on molecular analyses of the conserved photosynthetic psbA gene (coding for protein D1 of photosystem II reaction centre) as a diversity indicator of naturally occurring marine oxygenic picophytoplankton. The psbA genes proved to be good indicators of the presence of a wide variety of photosynthetic marine microbial groups, including new cyanobacterial groups and eukaryotic algae (prasinophytes). Furthermore, using environmental bacterial artificial chromosome (BAC) libraries, we were able to correlate psbA genes with small subunit rRNAs and, therefore, to confirm their phylogenetic affiliation.
Is there a role for the colorectal team in the management of acute severe third‐degree vaginal tears?
Authors: Cook  , Keane  , Mortensen
Published: March 2003

Objective

The repair of sphincter injuries following vaginal delivery is often inadequate. The purpose of this study was to assess the short‐term impact of involving a colorectal team in the management of patients with complicated acute severe third‐degree tears.

Patients and methods

Over a 1‐year period, four women (age 29–31 years) with acute severe third‐degree tears extending into the anal canal or rectum were referred to the colorectal unit for repair of the injury. The internal anal sphincter (IAS) was identified and imbricated. A nerve stimulator was used to help identify the external anal sphincter (EAS) which was repaired using an overlapping technique. The women were reassessed at 3 months with anal manometry, pudendal nerve latencies and anal ultrasound. Further clinical assessment was performed at 1 year.

Results

Anal ultrasound revealed intact EAS repairs in all four women, although the IAS was thinned anteriorly in two. Resting anal pressures were slightly low (range 40–56 cmH2O) but satisfactory squeeze pressures were obtained in all four women (range 78–100 cmH2O). Pudendal nerve latencies were normal in three and prolonged on one side in the fourth woman. At 1 year, three were continent to solids, liquids and flatus, incontinence score=0, but one had occasional urgency. The fourth experienced occasional liquid seepage and frequent incontinence to flatus likely to represent IAS dysfunction (incontinence score=7).

Conclusion

Satisfactory short‐term results may be achieved following repair of acute severe third‐degree tears and a nerve stimulator is important in identifying viable EAS to be used in repair. An integrated approach involving the experience of the colorectal team and anorectal physiology permits planning of future deliveries and may improve the long‐term outcome.
Rectal cancer recurrence: factors and mechanisms
Authors: Heriot  , Kumar
Published: March 2003

Objective

There have been significant developments in treatment for rectal carcinoma, both in surgical and adjuvant therapy. They may however have associated morbidity and hence individualized therapy for rectal cancer is desirable, to optimize treatment but avoid over‐treatment for cases where the risk of recurrence is low.

Materials and methods

A literature review was undertaken of the reported incidence of recurrence of rectal carcinoma following curative surgery, factors which predispose to recurrence and proposed mechanisms for recurrence, and the evidence for each critically evaluated.

Results

The incidence of local recurrence of rectal carcinoma following curative resection ranges from 2.6% to 32%, with an average of 15%. Tumour stage is the strongest predictor of tumour recurrence. Upstaging using molecular biology may predict increased risk of recurrence but is not yet proven. Histological factors including differentiation and vascular invasion increase recurrence but are imprecise. Tumour microvascular density and vascular endothelial growth factor (VEGF) levels may be predictive but need refinement. Adequate resection margins are important but recurrence may occur despite this. Tumour cell spillage and distant dissemination may be a mechanism for tumour recurrence following curative resection, but further research is required before this could be applied clinically.

Conclusion

Recurrence of rectal cancer remains a significant problem following ‘curative’ surgery. Multiple factors may influence recurrence risk, though currently however only tumour stage and histological resection margins have demonstrated sufficient importance for management decisions to be made upon them.
Comparison of prognosis in cancer of the colon and rectum
Authors: Hall  , Finan  , Brown  , Ai‐Jaberi  , Tsang
Published: March 2003

Objective

To determine whether there is a difference in prognosis between colon and rectal cancer.

Patients and methods

A prospective audit was conducted of a cohort of consecutive patients presenting to a single colorectal surgeon over an 8‐year period, in a teaching hospital colorectal unit. There were 492 patients, 274 with colon cancer and 218 with rectal cancer, followed up to death or for a median of 43 months. Resection of all macroscopic disease was performed where possible by performing, if necessary, en bloc excision of local disease in continuity with adjacent involved structures. There was total mesorectal excision for middle and lower third rectal cancers. The main outcome measures were local recurrence, any recurrence, and survival.

Results

Five year survival excluding non‐colorectal cancer deaths was 80% for colon cancer and 70% for rectal cancer after curative excision when all stages were grouped together (logrank P=0.25). Survival curves for Dukes’ A and B cancers at each site were the same. Dukes’ C rectal cancers recurred locally more frequently than colon cancers, but there was no significant difference in survival.

Conclusion

With appropriate radical surgery, survival after curative resection of rectal cancer can be as favourable as for colon cancer. Patients with Dukes’ C cancers of the rectum are more at risk of local recurrence and this group should be the focus of efforts to improve outcome further.
Emergency admission with colorectal cancer: its relationship to primary health care organization
Authors: Oldale  , McKenna  , Waddecar  , Scott
Published: March 2003

Objective

To determine if associations exist between emergency admission with colorectal cancer and patient demographics and features of primary health care organization.

Patients and methods

Between 1992 and 1997 a prospective study of 485 consecutive colorectal cancer admissions to the Hope Hospital Colorectal Cancer Database (HCCD) was performed. Details of patient gender, age, marital status, postcode and general practitioner (GP) code were recorded at admission. The Jarman (UPA) score was derived from each patient’s postcode. The GP code was used to identify from the local health authority lists for each patient, the number of GPs in the referring practice, the fund‐holding status of practice and the presence or absence of a GP trainer in the practice.

Results

Neither patient gender nor Jarman (UPA) score was associated with emergency admission. Patient age >75 years (P=0.05) and patient (single/divorced/widowed) marital status (P=0.07) were associated with emergency admission. There was no association between the number of GPs, the fund‐holding or training status of the referring practice and patient referral as an emergency with colorectal cancer.

Conclusion

Emergency admission with colorectal cancer is not associated with present aspects of primary health care organization—specifically number of GPs in practice, fund‐holding or training.
Abnormal hepatic perfusion index predicts recurrence of colorectal carcinoma
Authors: Sarela A. I. , Gallagher H. J. , Macadam R. C. A. , O’Riordain D. S. , Parkin A. , Guillou P. J.
Published: March 2003

Objective

The hepatic perfusion index (HPI) is a ratio of the gradient of hepatic arterial to total hepatic blood flow. This study correlated HPI with histopathological indicators of prognosis and disease‐free survival following curative resection of colorectal cancer.

Patients and methods

HPI was measured preoperatively by dynamic hepatic scintigraphy in 37 patients with a primary colorectal cancer and no evidence of distant metastases who underwent a curative resection.

Results

Abnormally elevated HPI were detected in 49% of patients and were significantly more frequent in association with locally advanced tumours (T3 and T4) in comparison with early tumours (T1 and T2; 59% vs 20%, respectively; P=0.04). There was no association between abnormal HPI and presence of lymph node metastases or degree of tumour differentiation. The 18‐month disease‐free survival rate of patients with abnormal HPI was significantly shorter than that of patients with normal HPI (53% vs 100%, respectively; P=0.01), and this was independent of the T category.

Conclusion

HPI predicts the risk of recurrent colorectal carcinoma, and this measurement should be included in the panel of prognostic markers in future clinical trials.
Results of anterior levatorplasty for rectocele
Authors: Lamah M. , Ho J. , Leicester R. J.
Published: March 2003

Objective

Transanal and transvaginal repair of rectocele have been advocated in the treatment of rectocele, with mixed results. The aim of this study was to assess our experience using anterior levatorplasty in the surgical management of rectocele.

Patients and methods

Sixty of 90 women who had undergone anterior levatorplasty for rectocele over a seven year period were traced, and 44 (33 with rectocele only and 11 with rectocele and faecal incontinence) responded to a standardized questionnaire 6 months to 7 years (mean 3.5 years) after anterior levatorplasty. Results were expressed in general and specific improvement of symptoms and were classified as excellent, good, fair, or poor. The effects on social activities, sexual function, and employment were also assessed.

Results

General satisfaction with the operation was rated as good or excellent in 27 of 33 (82%) and 18 of 24 (75%) patients with rectocele only at 2 and 3.2 years follow‐up, respectively, and in 7 of 11 (64%) and 5 of 11 (45%) patients with rectocele and faecal incontinence at 2 and 4 years follow‐up, respectively. 31 (70%) and 34 (77%) of all patients reported an improvement in sensation and the ability to defaecate, respectively. An improvement in social activities, sexual satisfaction and employment was noted in 10 of 21 (48%), 10 of 23 (43%), and 7 of 12 (58%) patients, respectively.

Conclusion

Anterior levatorplasty provides good short and long‐term symptomatic improvement in patients with rectocele and avoids complications associated with rectal or vaginal approaches.
Evaluation of the role of pre‐operative magnetic resonance imaging in the management of rectal cancer
Authors: Botterill I. D. , Blunt D. M. , Quirke P. , Sebag‐Montefiore D. , Sagar P. M. , Finan P. J. , Chalmers A. G.
Published: March 2003

Objectives

This study assesses the ability of body coil magnetic resonance imaging (MRI) to pre‐operatively stage mural penetration, nodal status and circumferential resection margin (CRM) involvement of rectal cancer.

Patients and methods

Between 1995 and 1997, MRI using a body coil was performed in consecutive patients with primary rectal carcinomas. Group A: 67 patients underwent surgery without long course neo‐adjuvant therapy. Predicted tumour stage was compared to the histology of the specimen. Group B: 21 patients with MRI evidence of advanced disease, underwent long course neo‐adjuvant therapy followed by repeat MRI prior to surgery. The second scan assessed response to treatment and likelihood of CRM involvement at subsequent surgery.

Results

Group A: Accuracy of pre‐operative staging was: ‘T’ stage – 54%, ‘N’ stage – 77%, involvement of CRM by tumour – 97%. Group B: After long course neo‐adjuvant therapy the second MRI scan was 95% accurate in predicting CRM involvement by tumour.

Conclusion

In this study pre‐operative rectal cancer staging with MRI and a body coil lacks accuracy in predicting mural penetration and nodal involvement. Body coil MRI can accurately predict the potential for CRM involvement. This technique may help determine which patients require long course neo‐adjuvant therapy.
Minimally invasive surgery for ileo–colic Crohn's disease
Authors: Motson R. W. , Kadirkamanathan S. S. , Gallegos N.
Published: March 2003

Objective

Patients requiring surgery for Crohn's disease are likely to undergo further surgery due to recurrent disease. A prospective study of laparoscopic‐assisted surgery for ileo‐colic Crohn's disease is reported.

Method

Forty‐one patients (26 female; median age 35 years) with ileo‐colic Crohn's disease, without evidence of either fistula or abscess formation underwent laparoscopic‐assisted surgery. All had medical therapy, including steroids, but had failed to respond or relapsed. Sixteen patients (39%) had previous surgery for Crohn's disease and 26 (63.4%) had previous abdominal surgery. Laparoscopic procedures (n=42) included ileocaecal/ileocolic resection (n=39), small bowel resection (n=1) and strictureplasty (n=2).

Results

The median operating time was 90 min (range 60–180). There were 6 conversions (14.6%). Of the 35 patients whose operation was completed laparoscopically, the median postoperative stay was 5 days (3–9) and the median time to full activity was 20 days (7–49). No major complications or death were recorded. The median follow up (34 out of 35) after surgery is 15.3 months (1–55). Twenty‐four patients remain symptom free and 4 have minimal symptoms with no clinical or radiological evidence of recurrence of Crohn's disease. Six have however, developed recurrence requiring medical (n=5) and surgical (n=1) treatment.

Conclusion

Laparoscopic‐assisted surgery for Crohn's disease is feasible. It has the advantage of minimizing hospital stay and promoting early recovery in a group of patients who are likely to have further surgery due to the nature of the disease.
Preperitoneal approach to parastomal hernia with coexistent large incisional hernia
Authors: Egun A. , Hill J. , MacLennan I. , Pearson R. C.
Published: March 2003

Objective

To assess the outcome of preperitoneal mesh repair of complex incisional herniae incorporating a stoma and large parastomal hernia.

Methods

From 1994 to 1998, symptomatic patients who had repair of combined incisional hernia and parastomal hernia were reviewed. Body mass index, co‐morbidity, length of hospital stay, patient satisfaction and outcomes were recorded.

Results

Ten patients (seven females and three males), mean age 62 (range 48–80) years underwent primary repair. All had significant comorbidities (ASA grade 3) and mean body mass index was 31.1 (range 20–49). Median hospital stay was 15 (range 8–150) days. Complications were of varying clinical significance (seroma, superficial infection, major respiratory tract infection and stomal necrosis). There were no recurrences after a mean follow up of 54 (range 22–69) months.

Conclusion

The combination of a parastomal hernia and generalised wound dehiscence is an uncommon but difficult problem. The application of the principles of low‐tension mesh repair can provide a satisfactory outcome and low recurrence rate. This must be tempered by recognition of the potential for significant major postoperative complication.
The outcome of surgery for complex anal fistula
Authors: Joy H. A. , Williams J. G.
Published: March 2003

Objective  The aim of this study was to examine the results of surgery for complex anal fistulas treated by a variety of techniques, in terms of fistula healing, recurrent anal sepsis and effect of surgery on anal continence.

Patients and methods  This study included 63 patients with complex fistulas treated between November 1995 and September 1999. A variety of techniques were employed, including short‐term loose seton drain (12), long‐term loose seton drain (11), cutting seton (17), and rectal advancement flap (19). Outcome was assessed at clinic review and continence was further assessed by detailed questionnaire sent to the patients sometime after surgery.

Results  Healing occurred in 9 (75%) patients treated with a short‐term, loose drainage seton; 16 (94%) patients treated with a cutting seton and 17 (89%) patients in the rectal advancement flap group. Incontinence reported at clinic review seemed to be more frequent in the advancement flap group. However, a detailed continence questionnaire revealed that 50% of patients reported episodes of incontinence to flatus or liquid after all techniques, which had not been detected at routine clinical review. Incontinence to solids was only reported by two of the patients who had been treated with a cutting seton.

Conclusions  Complex fistulas may be successfully treated by a variety of techniques. Disturbed anal continence following surgery is common and worse than clinic assessment would suggest.
Treatment of enterocele by abdominal colporectosacropexy – efficacy on pelvic pressure
Authors: Jean F. , Tanneau Y. , Le Blanc‐Louvry I. , Leroi A. M. , Denis P. , Michot F.
Published: March 2003

Objective  Enterocele induces pelvic pressure, obstructed defaecation, lower abdominal pain and/or false urge to defaecate in patients. The aim of this study was to evaluate the efficacy of abdominal colporectosacropexy in these symptoms, especially on pelvic pressure.

Methods  Sixty‐two consecutive women with enterocele were included. All patients were symptomatic because they had: pelvic pressure (n = 62), obstructed defaecation (n = 40), lower abdominal pain (n = 8) or faecal incontinence (n = 16). Defaecography confirmed enterocele in all patients. The surgical procedure was performed by the same surgeon and was an abdominal colporectosacropexy with a nonabsorbable Prolene® mesh. After surgery, clinical evaluation (62/62 patients) and a telephone questionnaire (56/62 patients) were performed, respectively, 3 months and 27 ± 13 months after surgery.

Results  Defaecography showed rectal abnormalities associated with enterocele in 59/62 patients (rectocele, rectal prolapse). No recurrence of enterocele was observed 3 months after surgery, but 1 patient demonstrated recurrence 10 months after surgery. Pelvic pressure was less frequent after abdominal colporectosacropexy, than before surgery (P < 0.01): pelvic pressure totally disappeared in 41/56 patients, and partially in 10/56 patients. The number of patients with obstructed defaecation, lower abdominal pain, or faecal incontinence was not different before and 27 months after surgery. The number of patients with urinary incontinence was also not different before and after surgery (30 and 27 patients).

Conclusions  This study of a large number of patients with enterocele shows that abdominal colporectosacropexy improves pelvic pressure in most patients and does not modify urinary status.
Intra‐operative injection of Patent Blue V dye to facilitate nodal staging in colorectal cancer
Authors: Gandy C. P. , Biddlestone L. R. , Roe A. M. , O'Leary D. P.
Published: March 2003

Objectives  Routine histopathology may understage colorectal cancer by failing to detect involved lymph nodes. This study examined the feasibility of dye staining those lymph nodes most likely to harbour metastases.

Patients and methods  Patent Blue V dye 2.5% was injected intra‐operatively into left‐sided colorectal carcinomas prior to resection in 19 patients.

Results  Blue‐stained nodes were found in 12/19 patients (63%). Examination of blue‐stained nodes alone correctly identified overall nodal status in 11 (92%) of these 12 patients.

Conclusion  The technique needs to be refined further. Nonetheless, intra‐operative lymph node staining using blue dye offers the prospect of improving the ease and accuracy of nodal staging in colorectal cancer.
Serum leptin levels are not influenced by physical training in type 2 diabetes mellitus patients
Authors: Ligtenberg P. C. , Hoekstra J. B. L. , Frölich M. , Meinders A. E. , Erkelens D. W.
Published: March 2003

Aim: To investigate the effect of physical training on leptin levels in elderly, obese patients with type 2 diabetes mellitus.

Methods: Twenty men and 38 women with type 2 diabetes mellitus with a body mass index (BMI) of > 25 kg/m2 participated in a prospective randomized study. Patients were either on oral glucose lowering drugs (n = 39) or insulin therapy (n = 19). Physical training consisted of a guided, standardized, 6‐week training programme performed in the hospital on a cyclo ergometer followed by a 6‐week period of guided training at home and ended in a 12‐week period of training at home without supervision. Clinical data and laboratory samples including fasting insulin and leptin levels and maximal aerobic capacity were assessed at the start of the study and at 6 and 26 weeks thereafter.

Results: Physical training resulted in significantly positive changes in maximal aerobic capacity (VO2max) and maximum work load. No effects of physical training on serum leptin levels and insulin concentrations were detected. Leptin levels were strongly correlated with body mass index (r = 0.63), body fat content (r = 0.61), and fasting insulin concentrations (r = 0.38). Women had threefold higher leptin levels than men. No differences in leptin levels between patients on insulin therapy and patients on oral glucose lowering drugs were found.

Conclusions: No effect of physical training on leptin levels was detectable in elderly, obese type 2 diabetes mellitus patients.
Effect of acarbose on additional insulin therapy in type 2 diabetic patients with late failure of sulphonylurea therapy
Authors: Standl E. , Baumgartl H. J. , Füchtenbusch M. , Stemplinger J.
Published: March 2003

Aim: The present study investigated the effect of acarbose on insulin requirements and glycaemic control in patients with type 2 diabetes receiving exogenous insulin due to secondary failure of maximum dose sulphonylurea therapy.

Methods: A single‐centre, double‐blind, randomized, placebo‐controlled study was performed in 48 type 2 diabetic patients with late‐term failure following at least 3 years of sulphonylurea therapy requiring additional insulin therapy to determine the impact of acarbose on glycaemic control and insulin requirements. The primary end points were glycaemic response rate (responders being predefined as patients who achieve a decrease in HbA1c to less than 8% or a reduction by at least 15% as compared to the baseline values) and the daily insulin dose at 6 months. Secondary parameters assessed included postprandial changes in blood glucose, serum insulin and C‐peptide during the treatment period.

Results: There were significantly more responders in the acarbose‐treated group compared

with the placebo group (20/24 patients vs. 10/19 patients; p < 0.05). The mean daily insulin dose after 24 weeks of treatment was 16.4 ± 10.1 IU in the acarbose group and 22.4 ± 12.2 IU in the placebo group (mean ± s.d.; p < 0.07). Postprandial increases in blood glucose, insulin and C‐peptide were consistently lower in the acarbose‐treated group than in the placebo group. For example, the mean increase in 2‐h postprandial serum insulin remained almost unchanged in the acarbose group at the end of 24 weeks of treatment compared to an increase to 43 ± 29 μU/ml (mean ± s.d.) at the end of the study period for the placebo group.

Conclusions: The findings of this study suggest that the addition of acarbose to sulphonylurea/insulin combination therapy can improve glycaemic control in type 2 diabetic patients. Acarbose may also reduce insulin resistance and hyperinsulinaemia.
Effect of diabetes on vitamin B6 requirement in experimental animals
Authors: Okada M. , Shibuya M. , Yamamoto E. , Murakami Y.
Published: March 2003

Aim: In the diabetic state, energy must be supplied mainly by amino acids and fat; therefore the metabolic processes are very similar to those of animals fed a high‐protein diet. Vitamin B6‐dependent enzymes, which are highly involved in amino acid metabolism, are important in diabetics. We investigated vitamin B6 content, and aspartate aminotransferase and glycogen phosphorylase activities, in several tissues of streptozotocin‐induced diabetic and control rats.

Methods: The rats were fed a vitamin B6‐free diet and administered an equivalent amount of pyridoxine based on body weight.

Results: Vitamin B6 content in all tisues examined, except for the liver, was lower in the diabetics than in controls. Aspartate aminotransferase activity was higher in the liver of diabetics than in the controls, but not in the other tissues. Glycogen phosphorylase activity in the gastrocnemius muscle of diabetics decreased to two‐thirds of the control level.

Conclusions: These data might indicate that diabetic animals should have a higher intake of vitamin B6 because a diabetic state can lead to a vitamin B6‐deficiency.
Ethnicity and risk factors for coronary heart disease in diabetes mellitus
Authors: Game F. L. , Jones A. F.
Published: March 2003

Introduction: The Framingham equation can be used to predict the risk of coronary heart disease (CHD) and so to target risk factor intervention. Reservations have been applied to its use in south Asian populations since the high CHD mortality in this group may not be accounted for by traditional risk factors.

Methods: We applied the Framingham equation to 1826 patients with diabetes of whom 1215 were of white Caucasian and 611 south Asian origin. Having calculated the 10‐year CHD risks the contribution of risk factors were compared between ethnic groups.

Results: Mean 10‐year CHD risk was the same in the two ethnic groups (20.7 vs. 21.5%, white Caucasian vs. south Asian men and 16.5 vs. 15.9%, white Caucasian vs. south Asian women). However, the risk factor profile was different between the two groups. Mean total cholesterol was lower in south Asians (5.23 vs. 5.41 mmol/l, south Asian vs. white Caucasian men (p = 0.01) and 5.38 vs. 5.68 mmol/l, south Asian vs. white Caucasian women (p < 0.001)). HDL cholesterol levels were also lower (median HDL cholesterol 0.94 vs. 1.11 mmol/l, south Asian vs. white Caucasian men (p < 0.001) and 1.07 vs. 1.3 mmol/l, south Asian vs. white Caucasian women (p < 0.0001)) leading to higher total : HDL cholesterol ratios (5.48 vs. 4.78, south Asian vs. white Caucasian men (p = 0.032) and 4.91 vs. 4.26, south Asian vs. white Caucasian women (p < 0.001).

Conclusion: Calculated 10‐year CHD risks are the same in south Asian and white Caucasian diabetic patients but the factors contributing to this risk differ. Different management of these risk factors may account for the higher mortality from CHD in those of south Asian origin.
Metabolic and haemodynamic effects of metformin in patients with type 2 diabetes mellitus and hypertension
Authors: Uehara M. H. , Kohlmann N. E. B. , Zanella M. T. , Ferreira S. R. G.
Published: March 2003

SUMMARY

Background  Since metformin improves insulin sensitivity, it has been indicated for patients with diabetes and hypertension, which are insulin‐resistant conditions. In contrast to its well‐known effects on carbohydrate metabolism, its potential for reducing blood pressure (BP) and its effect on leptin levels have been investigated less frequently.

Patients and Methods  A double‐blind, randomized, placebo‐controlled trial was carried out with 26 overweight diabetic subjects with mild‐to‐moderate hypertension to assess the effects of metformin‐induced glycaemic control on BP and metabolic parameters. After a 4‐week placebo period, when BP was stabilized by calcium channel blockers, they received either metformin (MG) or placebo (PG) for 12 weeks.

Results  Neither group showed any change in weight throughout the study. Only metformin‐treated patients reduced fasting plasma glucose (8.54 + 1.72 to 7.54 + 1.33 mmol/l, p < 0.05), although HbA1c had decreased in both groups (PG: 6.7±3.0 to 5.9±2.6%; MG: 5.3±1.5 to 4.6±0.9%; p < 0.05). The initial office mean BPs were similar and decreased at the end of the treatment period in both groups, reaching statistical significance only in MG (105.7±8.0 to 99.2±9.3 mmHg, p < 0.05). No difference was observed when comparing baseline and final values obtained by 24‐h ambulatory BP monitoring. Metformin induced a reduction in both insulinaemia (71.0±62.4 to 38.0±23.0 pmol/l, p < 0.05) and the insulin resistance index (3.5±2.7 to 1.8±1.0, p < 0.05). The two groups had similar baseline leptin levels which remained unchanged after treatment (PG: 16.8±7.9 to 21.4±14.6 μg/l; MG: 18.5±10.3 to 18.4±8.9 μg/l). Dopamine levels increased significantly only in metformin‐treated subjects.

Conclusions  Reductions in both the insulin levels and the resistance index reinforced metformin capacity to improve peripheral sensitivity. Moreover, such benefits were not accompanied by any hypotensive effects. Since leptin levels were affected neither by metformin per se nor by the induced insulinaemia reduction, our data support the role of body weight as the major determinant of circulating leptin levels.
Miglitol combined with metformin improves glycaemic control in type 2 diabetes
Authors: Van Gaal L. , Maislos M. , Schernthaner G. , Rybka J. , Segal P.
Published: March 2003

SUMMARY

Aim  To investigate the efficacy and safety of miglitol vs. placebo in type 2 diabetic outpatients insufficiently controlled (HbA1c between 7.5 and 10.5%) with diet and metformin.

Methods  Patients treated with diet and metformin (1500–2250 mg/day) were randomized to receive additional treatment with either miglitol or placebo for 32 weeks. The dosages were force‐titrated: 4 weeks at 25 mg miglitol t.i.d., 12 weeks at 50 mg miglitol t.i.d., and 16 weeks at 100 mg miglitol t.i.d. or matching placebo. If the highest dosage could not be tolerated, patients could be down‐titrated to 50 mg t.i.d. The primary efficacy criterion was the change in glycated haemoglobin (HbA1c). Secondary efficacy parameters included fasting and 1 h postprandial blood glucose, serum insulin, and fasting and 1 h postprandial triglyceride levels. Safety and tolerability were evaluated by the incidence of adverse events and changes in vital signs or routine biochemical and haematological parameters.

Results  One hundred and fifty‐two patients were valid for the intent‐to‐treat (ITT) analysis. There was a significant decrease in HbA1c on adding miglitol to metformin compared to adding placebo (miglitol treatment effect, − 0.21%; placebo treatment effect, + 0.22%; p = 0.011). Postprandial blood glucose declined in both the miglitol/metformin and placebo/metformin groups with a statistically significant difference in favour of miglitol/metformin (end of treatment adjusted means 13.8 mmol/l for miglitol vs. 15.8 mmol/l for placebo, p = 0.0007). Adverse events (AEs) were reported by only 8% more patients in the miglitol/metformin group than placebo/metformin. No cases of hypoglycaemia were reported.

Conclusions  Miglitol can safely and effectively be added to diet and metformin in patients whose type 2 diabetes is insufficiently controlled, and improves glycaemic control by significantly reducing HbA1c and postprandial blood glucose levels.