bluuebunny/crossref_metadata_2025 huggingface dataset:
Different portions of the maize root system host Burkholderia cepacia populations with different degrees of genetic polymorphism
Authors: Chiarini Luigi , Giovannelli Valeria , Bevivino Annamaria , Dalmastri Claudia , Tabacchioni Silvia
Published: March 2003

In order to acquire a better understanding of the spatial and temporal variations of genetic diversity of Burkholderia cepacia populations in the rhizosphere of Zea mays, 161 strains were isolated from three portions of the maize root system at different soil depths and at three distinct plant growth stages. The genetic diversity among B. cepacia isolates was analysed by means of the random amplified polymorphic DNA (RAPD) technique. A number of diversity indices (richness, Shannon diversity, evenness and mean genetic distance) were calculated for each bacterial population isolated from the different root system portions. Moreover, the analysis of molecular variance (
amova) method was applied to estimate the genetic differences among the various bacterial populations. Our results showed that, in young plants, B. cepacia colonized preferentially the upper part of the root system, whereas in mature plants, B. cepacia was mostly recovered from the terminal part of the root system. This uneven distribution of B. cepacia cells among different root system portions partially reflected marked genetic differences among the B. cepacia populations isolated along maize roots on three distinct sampling occasions. In fact, all the diversity indices calculated indicated that genetic diversity increased during plant development and that the highest diversity values were found in mature maize plants, in particular in the middle and terminal portions of the root system. Moreover, the analysis of RAPD patterns by means of the
amova method revealed highly significant divergences in the degree of genetic polymorphism among the various B. cepacia populations.
‘Clay hutches’: a novel interaction between bacteria and clay minerals
Authors: Lünsdorf  , Erb  , Abraham  , Timmis
Published: March 2003

Biofilm formation on a low‐energy substratum floating on the surface of a water column overlying a polychlorinated biphenyl (PCB)‐contaminated sandy clay soil was followed by light and electron microscopy. The biofilms that developed consisted of a dense lawn of clay aggregates, each one of which contained one or more bacteria, phyllosilicates and grains of iron oxide material, all held together by bacterial extracellular polysaccharides (EPS). The clay leaflets were arranged in the form of ‘houses of cards’ and gave the aggregates the appearance of ‘hutches’ housing the bacteria. Interestingly, although the soil is poor in carbon, and the weakly bioavailable PCBs constitute the principal source of carbon in this system, the bacteria contained electron‐transparent structures presumed to be carbon storage granules. These, and the EPS material present in the hutches, indicate that carbon is not limiting in this system and, as PCBs have been found associated with the clay mineral fraction of the floating substratum, the clay particles may serve as carbon shuttles. The interesting possibilities that the ‘clay hutches’ may represent a ‘soil microhabitat’, a ‘minimal nutritional sphere’ and an ‘effective survival unit’ for autochthonous bacteria are noted. The formation of clay hutches by bacteria would seem to merit further investigation, particularly regarding their roles in bacterial processes in soil and in geological processes.
Retrotransfer of DNA in the rhizosphere
Authors: Ronchel M. Carmen , Ramos‐Díaz M. Angeles , Ramos Juan L.
Published: March 2003

Retrotransfer of DNA refers to the phenomenon by which a plasmid travels from a host strain to a recipient one and returns to the original host, bringing with it DNA from the recipient. The resultant host strain with DNA from the recipient is called a retrotransconjugant. The retrotransfer phenomenon mediated by the TOL plasmid pWW0 and other plasmids has been documented on plates under optimal laboratory culture conditions, but never under natural conditions. In this work, we show that retrotransfer mediated by the IncP9 TOL pWW0 plasmid occurs in the rhizosphere, a niche in which the continuous supply of nutrients via root exudates allows cells to reach a high density. This suggests that this unusual sexual fertilization may be of great importance in lateral gene transfer. We also show that retrotransfer of DNA seems to require co‐integration of the plasmid and the host chromosome and subsequent resolution, because a TOL plasmid with a mutation in the tnpR gene, encoding the resolvase of the Tn4653 of the TOL plasmid, was self‐transferred between Pseudomonas strains, but unable to mobilize chromosome.
A novel and sensitive method for the quantification of N‐3‐oxoacyl homoserine lactones using gas chromatography–mass spectrometry: application to a model bacterial biofilm
Authors: Charlton Timothy S. , De Nys Rocky , Netting Andrew , Kumar Naresh , Hentzer Morten , Givskov Michael , Kjelleberg Staffan
Published: March 2003

A method is reported for the quantification of 3‐oxoacyl homoserine lactones (3‐oxo AHLs), a major class of quorum‐sensing signals found in Gram‐negative bacteria. It is based on the conversion of 3‐oxo AHLs to their pentafluorobenzyloxime derivatives followed by gas chromatography–mass spectrometry (electron capture–negative ion). The method used [13C16]‐N‐3‐oxo‐dodecanoyl homoserine lactone ([13C16]‐OdDHL) as the internal standard, and its validity was tested by spiking the supernatant and cell fractions with three levels of 3‐oxo AHLs, i.e. 1, 10 and 100 ng per sample. These showed the method to be both sensitive (S/N ratio > 10:1 for 1 ng) and accurate. The assay was applied to the biofilm and effluent of a green fluorescent protein (GFP)‐expressing strain of Pseudomonas aeruginosa (6294) culture grown in flow cells. Biofilm volume was determined for three replicate flow cells by confocal scanning laser microscopy. OdDHL was detected in the biofilm at 632 ± 381 µM and the effluent at 14 ± 3 nM. The biofilm concentration is the highest level so far reported for an AHL in a wild‐type bacterial system. The next most abundant 3‐oxo AHL in the biofilm and effluent was N‐3‐oxo‐tetradecanoyl homoserine lactone (OtDHL) at 40 ± 15 µM and 1.5 ± 0.7 nM respectively. OtDHL is unreported for P. aeruginosa and has an activity equivalent to OdDHL in a lasR bioassay. Two other 3‐oxo AHLs were detected at lower concentrations: N‐3‐oxo‐decanoyl homoserine lactone (ODHL) in the biofilm (3 ± 2 µM) and effluent (1 ± 0.1 nM); and N‐3‐oxo‐octanoyl homoserine lactone (OOHL) in the effluent (0.1 ± 0.1 nM).
Sulphate reduction and nitrogen fixation rates associated with roots, rhizomes and sediments from Zostera noltii and Spartina maritima meadows
Authors: Nielsen Lise B. , Finster Kai , Welsh David T. , Donelly Andrew , Herbert Rodney A. , De Wit Rutger , Lomstein Bente AA.
Published: March 2003

Sulphate reduction rates (SRR) and nitrogen fixation rates (NFR) associated with isolated roots, rhizomes and sediment from the rhizosphere of the marine macrophytes Zostera noltii and Spartina maritima, and the presence and distribution of Bacteria on the roots and rhizomes, were investigated. Between 1‰ and 3‰ of the surface area of the roots and rhizomes of both macrophytes were colonized by Bacteria. Bacteria on the surfaces of S. maritima roots and rhizomes were evenly distributed, while the distribution of Bacteria on Z. noltii roots and rhizomes was patchy. Root‐ and rhizome‐associated SRR and NFR were always higher than rates in the bulk sediment. In particular, nitrogen fixation associated with the roots and rhizomes was 41–650‐fold higher than in the bulk sediment. Despite the fact that sulphate reduction was elevated on roots and rhizomes compared with bulk sediment, the contribution of plant‐associated sulphate reduction to overall sulphate reduction was small (≤ 11%). In contrast, nitrogen fixation associated with the roots and rhizomes accounted for 31% and 91% of the nitrogen fixed in the rhizosphere of Z. noltii and S. maritima respectively. In addition, plant‐associated nitrogen fixation could supply 37–1613% of the nitrogen needed by the sulphate‐reducing community. Sucrose stimulated nitrogen fixation and sulphate reduction significantly in the root and rhizome compartments of both macrophytes, but not in the bulk sediment.
The chicken, the egg andSalmonella enteritidis
Authors: Guard‐Petter Jean
Published: March 2003

Salmonella entericaserovar Enteritidis is the cause of the food‐borne salmonellosis pandemic in humans, in part because it has the unique ability to contaminate eggs without causing discernible illness in the birds infected. The infection route to humans involves colonization, survival and multiplication of the pathogen in the hen house environment, the bird and, finally, the egg. This review highlights the stages of transmission and discusses evidence that altered bacterial growth patterns and specific cell surface characteristics contribute to the adaptation ofS. enteritidisto these diverse environments.
Genetically engineered Pseudomonas: a factory of new bioplastics with broad applications
Authors: Olivera Elías R. , Carnicero David , Jodra Ruth , Miñambres Baltasar , García Belén , Abraham Gustavo A. , Gallardo Alberto , Román Julio San , García José L. , Naharro Germán , Luengo José M.
Published: March 2003

New bioplastics containing aromatic or mixtures of aliphatic and aromatic monomers have been obtained using genetically engineered strains of Pseudomonas putida. The mutation (–) or deletion (Δ) of some of the genes involved in the β‐oxidation pathway (fadA−, fadB−ΔfadA or Δfad BA mutants) elicits a strong intracellular accumulation of unusual homo‐ or co‐polymers that dramatically alter the morphology of these bacteria, as more than 90% of the cytoplasm is occupied by these macromolecules. The introduction of a blockade in the β‐oxidation pathway, or in other related catabolic routes, has allowed the synthesis of polymers other than those accumulated in the wild type (with regard to both monomer size and relative percentage), the accumulation of certain intermediates that are rapidly catabolized in the wild type and the accumulation in the culture broths of end catabolites that, as in the case of phenylacetic acid, phenylbutyric acid, trans‐cinnamic acid or their derivatives, have important medical or pharmaceutical applications (antitumoral, analgesic, radiopotentiators, chemopreventive or antihelmintic). Furthermore, using one of these polyesters (poly 3‐hydroxy‐6‐phenylhexanoate), we obtained polymeric microspheres that could be used as drug vehicles.
Reduction of Fe(III) oxide by methanogens in the presence and absence of extracellular quinones
Authors: Bond Daniel R. , Lovley Derek R.
Published: March 2003

Five methanogens (Methanosarcina barkeri MS, Methanosphaera cuniculi 1R7, Methanobacterium palustre F, Methanococcus voltaei A3 and Methanolobus vulcani PL‐12/M) were investigated for their ability to reduce Fe(III) oxide and the soluble quinone anthraquinone‐2,6‐disulphonate (AQDS). Two species (M. barkeri and M. voltaei) reduced significant amounts of Fe(III) oxide using hydrogen as the electron donor, and 0.1 mM AQDS greatly accelerated Fe(III) reduction by these organisms. Although Fe(III) appeared to inhibit growth and methanogenesis of some strains, hydrogen partial pressures under donor‐limited conditions were much lower (<0.5 Pa) in the presence of Fe(III) than in normal media (1–10 Pa) for all species except for M. vulcani. These results demonstrate that electrons were transferred to Fe(III) by hydrogen‐utilizing methanogens even when growth and methanogenesis were inhibited. All species except the obligate methylotroph M. vulcani were able to reduce AQDS when their growth substrates were present as electron donors, and rates were highest when organisms used hydrogen as the electron donor. Purified soil humic acids could also be reduced by the AQDS‐reducing methanogens. The ability of methanogens to interact with extracellular quinones, humic acids and Fe(III) oxides raises the possibility that this functional group of organ‐isms contributes to Fe(III) and humic acid reduction under certain conditions in the environment and provides an alternative explanation for the inhibition of methanogenesis in some Fe(III)‐containing ecosystems.
Isolation of small‐subunit rRNA for stable isotopic characterization
Authors: MacGregor Barbara J. , Brüchert Volker , Fleischer Swantje , Amann Rudolf
Published: March 2003

Small‐subunit ribosomal RNA (SSU rRNA) has several characteristics making it a good candidate biomarker compound: it is found in bacteria, archaea and eukaryotes; it is quickly degraded extracellularly, hence SSU rRNA extracted from a sample probably derives from the currently active population; it includes both conserved and variable regions, allowing the design of capture probes at various levels of phylogenetic discrimination; and rRNA sequences from uncultured species can be classified by comparison with the large and growing public database. Here we present a method for isolation of specific classes of rRNAs from mixtures of total RNA, employing biotin‐labelled oligonucleotide probes and streptavidin‐coated paramagnetic beads. We also show that the stable carbon isotope composition of Escherichia coli total RNA and SSU rRNA reflects that of the growth substrate for cells grown on LB, M9 glucose and M9 acetate media. SSU rRNA is therefore a promising biomarker for following the flow of carbon, and potentially nitrogen, in natural microbial populations. Some possible applications are discussed.
Analysis of the microbial community structure and function of a laboratory scale enhanced biological phosphorus removal reactor
Authors: Levantesi Caterina , Serafim Luísa S. , Crocetti Gregory R. , Lemos Paulo C. , Rossetti Simona , Blackall Linda L. , Reis Maria A. M. , Tandoi Valter
Published: March 2003

A laboratory scale sequencing batch reactor (SBR) operating for enhanced biological phosphorus removal (EBPR) and fed with a mixture of volatile fatty acids (VFAs) showed stable and efficient EBPR capacity over a four‐year‐period. Phosphorus (P), poly–β–hydroxyalkanoate (PHA) and glycogen cycling consistent with classical anaerobic/aerobic EBPR were demonstrated with the order of anaerobic VFA uptake being propionate, acetate then butyrate. The SBR was operated without pH control and 63.67 ± 13.86 mg P l−1 was released anaerobically. The P% of the sludge fluctuated between 6% and 10% over the operating period (average of 8.04 ± 1.31%). Four main morphological types of floc‐forming bacteria were observed in the sludge during one year of in‐tensive microscopic observation. Two of them were mainly responsible for anaerobic/aerobic P and PHA transformations. Fluorescence in situ hybridization (FISH) and post‐FISH chemical staining for intracellular polyphosphate and PHA were used to determine that ‘Candidatus Accumulibacter phosphatis’ was the most abundant polyphosphate accumulating organism (PAO), forming large clusters of coccobacilli (1.0–1.5 µm) and comprising 53% of the sludge bacteria. Also by these methods, large coccobacillus‐shaped gammaproteobacteria (2.5–3.5 µm) from a recently described novel cluster were glycogen‐accumulating organisms (GAOs) comprising 13% of the bacteria. Tetrad‐forming organisms (TFOs) consistent with the ‘G bacterium’ morphotype were alphaproteobacteria, but not Amaricoccus spp., and comprised 25% of all bacteria. According to chemical staining, TFOs were occasionally able to store PHA anaerobically and utilize it aerobically.
Metabolic shifts in hypersaline microbial mats upon addition of organic substrates
Authors: Grötzschel Stefan , Abed Raeid M. M. , De Beer Dirk
Published: March 2003

The responses of hypersaline microbial mats to the addition of acetate, glycolate or glucose were investigated using oxygen, pH and sulphide microsensors. Changes in community structure were investigated with molecular techniques. Acetate addition inhibited respiration in the photic zone, stimulated respiration in the aphotic zone and had no effect on gross photosynthesis. Glycolate addition strongly increased both respiration and gross photosynthesis in the photic zone. Thus, glycolate and acetate were probably consumed in those regions of the mat where these substrates are usually formed. Moreover, photosynthesis was only stimulated by increased respiration and concomitant CO2 production in the photic zone which indicates that the photosynthetic and respiratory populations must be present in close proximity to each other. Glucose addition had an unexpected negative effect on the microbial population, strongly inhibiting both respiration and gross photosynthesis within hours. After four days, oxygen profiles in the light were equal to those measured in the dark. After replacing the water phase with unamended water, photosynthesis and respiration recovered within a week. None of the physiological changes were accompanied by detectable shifts in the cyanobacterial or the overall microbial community. The mechanism of inhibition of photosynthesis by glucose requires further investigation.
Non‐invasive determination of plant‐associated bacteria in the phyllosphere of plants
Authors: Gau Achim E. , Dietrich Christof , Kloppstech Klaus
Published: March 2003

Epiphytic living Pseudomonas strains isolated from different Malus domestica cultivars were transformed with two reporter genes [green fluorescent protein (gfp) and luciferase (luxAB)]. The establishment and distribution of these bacteria on sterile, in vitro‐propagated, and thus genetically identical, Malus domestica plants were continuously analysed with a cooled, back‐illuminated, charge‐coupled‐device (CCD) camera system. The combination of the assessment of bioluminescence and the use of a CCD camera offer an intriguing method to study, non‐invasively and in real time, plant–microbe interactions as well as the colonization of the phyllosphere by microorganisms. Here we report on the applicability and sensitivity of the method with the goal to investigate quantitatively the interaction of symbiotic and pathogenic microorganisms with the corresponding host plant. It will be shown that the three bacterial isolates of the genus Pseudomonas studied, differ considerably with respect to their establishment on the host plants. It will also be shown that the chosen host apple variety has an impact on the activity of the bacterial cultivars. Analysis by a laser scanning fluorescence microscope provides the first evidence for the mode by which the epiphytic microorganisms interact with the plant.
Diversity of siderophore‐mediated iron uptake systems in fluorescent pseudomonads: not only pyoverdines
Authors: Cornelis Pierre , Matthijs Sandra
Published: March 2003

Fluorescent pseudomonads are γ‐proteobacteria known for their capacity to colonize various ecological niches. This adaptability is reflected by their sophisticated and diverse iron uptake systems. The majority of fluorescent pseudomonads produce complex peptidic siderophores called pyoverdines or pseudobactins, which are very efficient iron scavengers. A tremendous variety of pyoverdines has been observed, each species producing a different pyoverdine. This variety can be used as an interesting tool to study the diversity and taxonomy of fluorescent pseudomonads. Other siderophores, including newly described ones, are also produced by pseudomonads, sometimes endowed with interesting properties in addition to iron scavenging, such as formation of complexes with other metals or antimicrobial activity. Factors other than iron limitation, and different regulatory proteins also seem to influence the production of siderophores in pseudomonads and are reviewed here as well. Another peculiarity of pseudomonads is their ability to use a large number of heterologous siderophores via different TonB‐dependent receptors. A first genomic analysis of receptors in four different fluorescent pseudomonads suggests that their siderophore ligand repertoire is likely to overlap, and that not all receptors recognize siderophores as ligands.
Monitoring the colonization of monuments by bacteria: cultivation versus molecular methods
Authors: Laiz Leonila , Piñar Guadalupe , Lubitz Werner , Saiz‐Jimenez Cesareo
Published: March 2003

Building materials commonly used in wall paintings and monuments (mortar, limestone and sandstone) were inoculated with an artificial consortium composed of 14 microorganisms and incubated for 6 months at 28°C. The colonization of the different materials by the consortium was investigated. Culture‐independent techniques revealed the presence of a diversity of bacteria, whereas culture‐dependent techniques yielded mainly spore‐forming bacteria. The data suggest that plating leads to an overestimation of the number of spore‐forming bacteria with respect to quiescent vegetative forms; the latter are less easily cultured, but are readily detected by culture‐independent techniques.
Persistence ofSalmonellaEnteritidis Phage Type 4 in the environment and arthropod vectors on an empty free‐range chicken farm
Authors: Davies Robert H. , Breslin Mark
Published: March 2003

The persistence ofS.Enteritidis PT4 was studied on a free‐range breeding chicken farm which had been depopulated following identification of the organism in breeding birds. The site was sampled periodically for 26 months after depopulation and the organism was found to persist in litter, dried faeces and feed, but not in dust within empty poultry houses, for the whole of that period.SalmonellaEnteritidis PT4 was also found in soil samples after 8 months but not 13 months and in faeces from wild mice, foxes and cats but not wild birds or badgers. The organism was also found in adult and larval forms of ground beetles and centipedes. Addition of pullets to a contaminated pen or inclusion of contaminated litter, feed or beetles/larvae to feed did not result in acquisition of infection by birds.
Delays experienced by patients with symptomatic colorectal cancer
Authors: Wheeler  , Wakefield  , Mortensen N. J. McC. , Kettlewell
Published: March 2003

Objective

To measure delays in diagnosis and treatment of colorectal cancer (CRC), assessing changes since a similar study in 1979. To ascertain whether modern diagnostic techniques have improved Dukes' staging at treatment.

Patients and methods

Prospective data collection. All patients diagnosed with CRC at the Oxford Radcliffe Hospital between January 1994 and January 1995 were questioned about their symptoms. Delays between symptom onset and definitive treatment were measured.

Results

On average, patients with colonic carcinoma consulted their general practitioner (GP) 9.6 weeks after symptom onset, whereas those with rectal carcinoma waited 20.8 weeks. GP referral accounted for an average 6.7 and 5.0 week delay for colonic and rectal cancers, respectively. Waiting for out‐patient appointments accounted for an average delay of 4.6 weeks for both. Those with non‐specific referrals waited an average of 9.0 weeks against 2.0 weeks when GPs mentioned CRC. There was an average 7·7 week delay for treatment of colonic cancer, and 6·3 weeks for rectal cancer. Pre‐hospital delays compared favourably with 1979, but post‐referral delays were longer. Total delay was unchanged in 15 years, and there was no improvement in Dukes' staging.

Conclusion

Despite prompt GP consultation and out‐patient referral, delays in the treatment of CRC now occur after referral to hospital. Patients referred without mention of CRC wait longest. Colonoscopy and double contrast barium enema have not improved tumour staging at treatment.
A comparison of function and patient satisfaction after restorative proctocolectomy for ulcerative colitis (UC) and familial adenomatous polyposis (FAP)
Authors: Körsgen  , Keighley
Published: March 2003

Obective

Function after restorative proctocolectomy for UC and FAP varies. We assessed function, satisfaction and social activity in patients with ileal pouch‐anal anastomosis and explored possible factors associated with poor function.

Patients and methods

We reviewed all case notes and sent postal questionnaires to 145 patients (121 UC, 24 FAP).

Results

One hundred and twenty questionnaires were returned (98 UC and 22 FAP). The complication rate, particularly pouch failure, was higher in the UC group (UC 18·8%, FAP 8%). Functional outcome was similar: 74% of UC patients and 68% of FAP patients had an acceptable result. Although social activity was similar in the UC and FAP groups, satisfaction with the outcome was much less in the FAP group.

Conclusion

Patients, particularly with FAP, who are asymptomatic need to be told about the functional outcome they can expect, particularly bowel frequency and soiling. Restorative proctocolectomy may not be the best option for all FAP patients.
A multivariate analysis of the factors associated with wound infection after colorectal surgery
Authors: Platell  , Hall  , Hall
Published: March 2003

Objectives

Wound infection has been proposed as a key indicator of clinical outcome after colorectal surgery. The aim of this study was to identify risk factors that were associated with wound infections in patients undergoing either emergency or elective colonic resections.

Patients and methods

We prospectively evaluated 251 patients admitted to Royal Perth Hospital over a 12‐month period. All patients received prophylactic peri‐operative antibiotics and were reviewed for 6 weeks post‐operatively. Wound infection was defined as either the presence of pus or a serous discharge containing pathogenic bacteria. We evaluated the relationship between 40 independent variables and the incidence of wound infection.

Results

There were 124 males and 127 females, of median age 68 years (range 14–90 years). The overall incidence of wound infection was 12%. Multiple logistic regression identified the presence of shock (odds ratio (OR) 14.6, P=0.05), atelectasis (OR 3.9, P=0.02), and number of days on antibiotics before surgery (OR 1.2, P=0.02) as significant independent variables.

Conclusion

These results suggest that the factors which were most often associated with wound infection were those that are indicative of either extensive disease or poor general health. The presence of a stoma and colonic perforation were not strong independent associations with wound infection.
Complacency or ignorance about rectal bleeding?
Authors: Kocher  , Saunders
Published: March 2003

Objective

The aim is to assess the importance that patients attach to their symptoms of rectal bleeding and their perception of its possible causes.

Patients and methods

Patients referred by their general practitioner (GP) to the Surgical Out‐patients Clinic with a history of rectal bleeding were asked to fill in a questionnaire about the symptoms and their perceptions of the complaint. Data on 104 (61 female, 43 male) consecutive patients between the ages of 17 and 88 years are presented.

Results

Fifty‐eight (55.8%) patients had experienced rectal bleeding on at least one previous and unrelated occasion, many (n=32) patients experienced it multiple times. However, only two‐thirds (n=36) of patients immediately sought advice. Embarrassment, non‐importance or ‘that the bleeding stopped too quickly’ were the most cited reasons for delay. Increasing personal concern (66.3%), the development of accompanying symptoms (16.3%), persistent bleeding (9.6%), or the bleeding becoming a nuisance (3.8%), prompted medical advice. Seventy‐five percent of patients were immediately referred on by their GP. Only 46 (44.2%) patients associated rectal bleeding with cancer of the large bowel. Haemorrhoids (piles) was most frequently acknowledged (92 patients or 88.5%). Anal fissure, polyps, colitis, and diverticulosis were also recognized causes.

Conclusion

Improved health information relating to colorectal cancer, perhaps in a more direct symptom format reflecting the importance of rectal bleeding, is necessary to reduce patient complacency.
Reporting colonic mucosal biopsies in inflammatory conditions: a new approach
Authors: Haboubi  , Schofield
Published: March 2003

There may be considerable difficulty in making a definitive diagnosis in colitis from histopathology alone. This study is based on a well‐tried system which has been used for 15 years in the University Hospital of South Manchester for the reporting of colonic biopsies. The varieties of histopathological pattern seen in colitis are described and the study shows how they can be used to refine diagnosis when good communication is maintained between the clinician and the histopathologist. The histopathology report is based on describing histological patterns rather than diagnoses but includes a differential diagnosis. The pathology report will allow the clinician together with the known clinical information to make an appropriate management decision. Ideally the final diagnosis is reached at a clinico–pathological conference.
Thrombospondin in colorectal disease
Authors: Behzad  , Abdalla  , Gardy  , Battrick  , Kumar  , Haboubi
Published: March 2003

Objective

To assess the presence of thrombospondin (TSP) in normal and colonic disease and correlate its presence to survival in colorectal cancers.

Materials and methods

A specific antibody was used to stain paraffin‐embedded sections of human colorectal disease (103 carcinomas, 10 inflammatory bowel disease (IBD), 10 diverticulosis and 10 normal). The stained sections were viewed by light microscopy and the degree of staining was quantified using computer‐assisted image analysis system.

Results

Seventy‐three percent of carcinomas, 30% of IBD and 80% of the diverticulosis specimens stained for TSP. None of the ‘normal’ specimens examined showed any staining. No significant correlation could be detected between TSP expression and survival in colorectal cancer patients.

Conclusion

The presence of TSP in the colon is not specific and merely indicates the presence of a disease process.
Should air contrast computed tomography become the first investigation of the colon of frail or elderly patients?
Authors: Murray D. , Hellawell G. , Oakley R. , Rosenfeld K. , Al‐Mufti R. A. M. , Lewis A. A. M. , Berger L. A.
Published: March 2003

Objective

Air contrast computed tomography (ACCT) is an alternative test to barium enema or colonoscopy. We review our experience of this test as the first investigation of frail, elderly patients with lower gastrointestinal symptoms, and record the subsequent clinical course of these patients to evaluate the efficacy of the technique.

Patients and methods

We performed 109 ACCT studies on frail patients aged 70 years or over with lower gastrointestinal symptoms. The findings were correlated with subsequent investigations and surgical findings. Patients with normal scans were followed up in out‐patients or by their GP. Average follow up was 17 months.

Results

A good quality complete examination of the colon was achieved in 97% of patients. Of 109 examinations 34 (31%) were reported as normal, 65 (60%) as diverticular disease, nine (8%) as demonstrating a colonic malignancy and one (1%) showed a benign polyp. One sigmoid tumour was missed initially but diagnosed on a repeat ACCT study.

Conclusion

ACCT is a reliable, well‐tolerated technique in elderly frail patients.
Identifying rectal carcinoma with distal submucosal spread
Authors: Kraemer  , Seow‐Choen  , Ho  , Eu  , Ho
Published: March 2003

Objective

This study was designed to find features that would preoperatively identify a high risk of distal submucosal spread in patients with rectal carcinoma.

Patients and methods

The resected specimens of 124 patients with rectal carcinoma were prospectively examined for submucosal spread. The results were correlated with patho‐anatomical, histological, and operative findings.

Results

There were 64 male and 60 female patients with a mean age of 62 years. Distal submucosal spread was detected in four (3%) patients, all with Dukes’ C or disseminated carcinoma and macroscopic and microscopic signs of advanced and aggressive tumour growth. In particular, all cases had advanced lymph node involvement (N3, P=0.0005) and all tumours were classified as poorly differentiated (P=0.0002). The presence of both features gave a 31% chance of distal submucosal spread in our series.

Conclusion

Distal submucosal tumour spread is associated with poorly or undifferentiated tumours and advanced lymph node involvement. Preoperative identification of patients at risk of distal submucosal spread requiring more extensive distal clearance is possible.
Comparison of micronutrients in patients having had panproctocolectomy and either ileal pouch anal anastomosis or Brooke ileostomy for chronic ulcerative colitis (UC)
Authors: Whineray E. , Inder W. J. , Roche D. , Dobbs B. R. , Frizelle F. A.
Published: March 2003

Objective

Patients having panproctocolectomy undergo major metabolic changes. A recent study suggested that patients who have had a panproctocolectomy and ileal pouch‐anal anastomosis (IPAA) may be trace element‐deficient, while other recent evidence has suggested a gradual decrease in vitamin B12. This study was undertaken to compare patients who had a panproctocolectomy for UC in combination with either an IPAA or a Brooke ileostomy (BI), and to determine whether the type of surgery post‐proctocolectomy influences the absorption of trace elements, as well as comparing the levels after both operations with the normal population values.

Patients and methods

One hundred randomly selected patients who had had a panproctocolectomy for UC (50 IPAA, 50 BI) were invited to take part in the study by letter. The patients who consented had blood taken for haemoglobin, serum iron, ferritin, serum folate, red cell folate, vitamin B12, insulin‐like growth factor‐1 (IGF‐1), albumin, and the trace elements copper, magnesium, manganese, selenium, and zinc.

Results

Of the 100 patients, 46 consented to participate in the study (23 IPAA, 23 BI). The age of the BI group was significantly higher than those of the IPAA group (mean age IPAA 44 years, BI 52 years, P < 0.05). There was no significant difference between the two groups with respect to time since operation, mean levels of haemoglobin, iron indices, albumin, serum and red cell folate, vitamin B12, or any of the trace elements examined. Plasma IGF‐1 was higher in the IPAA group, but this was no longer significant when adjusted for age.

Conclusion

No difference was found in trace element status in patients who had had a panproctocolectomy for UC with either an IPAA or BI. Furthermore, no difference existed between these two groups.
Patient quality of life after successful restorative proctocolectomy is normal
Authors: Richards D. M. , Hughes S. A. , Irving M. H. , Scott N. A.
Published: March 2003

Objective

To measure quality of life (QoL), using validated health status instruments, of patients with functioning IPAA for CUC.

Patients and methods

Between 1986 and 1997, a total of 77 patients had an IPAA. Thirteen patients were excluded [6 excised, 3 awaiting ileostomy closure, 2 lost to follow up, 2 serious unrelated illnesses]. Postal survey using SF36 and EuroQol questionnaires. Age, sex, year of pouch construction and stool frequency were documented.

Results

Fifty‐six patients (87.5%) replied. Male:female ratio; 3:2. Median age; 34 years (range 13–64). Median time since pouch construction; 4 years (range 1–10 years). Median SF36 scores (range); physical function 86.6 (0–100), physical role 81.6 (0–100), body pain 78.4 (22–100), general health 61.6 (5–100), vitality 57.6 (5–100), social function 75.4 (25–100), emotional role 83.5 (0–100), mental health 70.7 (16–100). All the SF36 scores were within the normal range, as were the EuroQol scores. Median EuroQol score (range); 0.85 (−0.07–1.0). Median EuroQol thermometer score (range); 83.3 (20–100). There was no correlation between objective QoL score and age, gender, stool frequency and year of pouch construction.

Conclusion

The QoL for patients with a functioning IPAA for CUC measured using validated health status instruments is normal. Age, gender, stool frequency and year of construction do not affect QoL outcome after the IPAA for ulcerative colitis.
Is routine histological reporting of doughnuts justified after anterior resection for colorectal cancer?
Authors: Pullyblank A. M. , Kirwan C. , Rigby H. S. , Dixon A. R.
Published: March 2003

Objective

‘Doughnuts’ of colonic tissue which remain on a circular stapler after firing are routinely examined histologically. However, Royal College of Pathologists’ guidelines state that this is not necessary. The aim of this study was to examine current practice among pathologists in one region in the UK and to determine the incidence of clinically significant pathology within colonic doughnuts.

Methods

Current practice in all pathology Departments within the South‐west Region was examined and 100 doughnuts from anterior resection specimens were reviewed for the presence of abnormal pathology.

Results

Practice varied between hospitals with only 15% following guidelines for examination of doughnuts and 38% following guidelines for reporting of resection margins. Review of pathology specimens demonstrated no incidence of colonic adenocarcinoma in a doughnut. Benign pathology was present in 9% and dysplasia in 3% but in no case was patient management altered as a result of the pathology report.

Conclusion

Application of recommended guidelines is inconsistent. We have demonstrated a low incidence of clinically significant pathology in doughnuts and more economical guidelines could therefore be safely applied without detriment to patient care.
Colorectal subspecialization in a DGH. The way forward!
Authors: Shankar P. J. , Achuthan R. , Haray P. N.
Published: March 2003

Aims

To audit all aspects of the diagnosis and management of colorectal cancers by a specialist unit within a District General Hospital (DGH). To compare the clinical effectiveness of the specialist service with the service prior to specialization and attempt to assess the feasibility of setting up such a service within the constraints imposed by a DGH.

Materials and methods

Data for this study was collected prospectively over a 3‐year period from July 1997 to June 2000 since the establishment of a specialist colorectal service. The results so obtained have been compared with the Trent and Wales audit of 1993 as well as with the guidelines issued by the Royal College of Surgeons of England and the Association of Colo‐proctologists of Great Britain and Ireland. We have attempted to evaluate whether specialization has altered the outcome for patients with colorectal cancer.

Results

A total of 2181 patients were seen at the specialist colorectal clinic and 42% underwent immediate flexible sigmoidoscopy. A total of 241 colorectal cancers were diagnosed during this period by the specialist unit, of which the rapid access clinic had picked up 191 (a pick‐up rate of 8.75%). The mean age of patients with colorectal cancer was 69.23 years and the median waiting time from referral to clinic and from referral to treatment was 9 days and 24 days, respectively. These compare favourably with the waiting times prior to specialization. 117 rectal cancers were diagnosed of whom 32 (32%) underwent APER. A selective approach to short course preoperative radiotherapy resulted in 24% of rectal cancer patients receiving this treatment. The CRM was positive in 14% of resected rectal cancers, all of whom had received preoperative radiotherapy. The percentage of patients with Dukes’ stage A disease has risen from 11% in 1993 to 23% and the percentage of patients undergoing emergency surgery have fallen from 29% in 1993 to 8.2%. The rate of permanent stoma formation has also decreased from 52% to 32%. This audit has also confirmed that the guidelines for the management of colorectal cancers were all being met or exceeded.

Conclusion

The study demonstrates that, even within the constraints of a DGH, a specialist service can result in earlier diagnosis, shorter waiting periods and judicious use of adjuvant treatment leading to improved clinical effectiveness. It is possible to deliver a high quality service, which meets, and in some areas, surpasses the minimum guidelines, provided there is an integrated multidisciplinary approach.
The role of anal ultrasound in the management of anal fistulas
Authors: Lindsey I. , Humphreys M. M. , George B. D. , Mortensen N. J. M. C.
Published: March 2003

Objective

To assess the accuracy of anal ultrasound (AUS) for anal fistulas, and the impact of routine pre‐operative AUS on their surgical management.

Methods

Pre‐operative AUS was performed in 38 consecutive patients with an anal fistula using a 10‐MHz Brüel & Kjaer probe. All patients underwent subsequent examination under anaesthetic (EUA) with documentation of the anatomy of the fistula before the surgeon was shown the AUS results. Agreement between AUS and EUA findings and any modification to the surgical treatment was recorded.

Results

There was 84% agreement between AUS and EUA findings regarding presence and site of fistulas. One fistula not seen at AUS was found at EUA, and 5 fistulas seen on AUS were not demonstrated at EUA. AUS influenced the surgery undertaken in 9/24 (38%) patients; demonstrating occult sphincter defects (2 patients), reclassifying fistulas from low to higher fistulas (3 patients), deciding a surgical treatment open to doubt (2 patients) and helping identify an obscure fistula not initially found at EUA (2 patients).

Conclusions

Accuracy of AUS in the assessment of anal fistulas is confirmed. Operative management is influenced in 38% of cases, usually towards more conservative treatment. We recommend the use of pre‐operative AUS in the assessment of anal fistulas.
Screening sigmoidoscopy in persons aged 60 years
Authors: Santavirta J.
Published: March 2003

Objective

To reduce mortality associated with colorectal cancer, an increased interest has focused in recent years on screening of colorectal cancer. No studies of colorectal cancer screening in Finland has been reported. A pilot study of screening sigmoidoscopy was started in 1994 and the results are presented in this paper.

Subjects and methods

Between March 1994 and May 2000 all 1224 persons aged 60 years from four communities (population 15 400) were invited to screening sigmoidoscopy; 896 (73%) took part in this study. The screening procedure was flexible sigmoidoscopy to 60 centimetres. All the patients who had adenomas or cancers, were invited to have a double contrast barium enema (DCBE) or colonoscopy to investigate the proximal colon. To study the experience of persons undergoing screening sigmoidoscopy, a questionnaire was sent to 81 consecutive persons after the examination. Sixty persons (74%) returned the filled‐in questionnaire.

Results

Hyperplastic polyps were found in 136 people (15.2% of the whole material). Hyperplastic polyps were more common in males than females (19.3% and 11.4%, respectively, P=0.0015). People with hyperplastic polyps had the same rate of neoplasia as people without. Neoplastic lesions were found in 65 people. Adenomas were found in 62 patients (6.9%). Twenty‐five people (2.8%) had at least one advanced adenoma (>10 mm or villous component). The rate of advanced adenomas in males was 4.9% and in females 0.9% (P=0.0006). Three patients (0.3%) were found to have colorectal cancer. Of 43 diabetic patients, 7 (16.3%) had adenomas whereas 6.5% of the non‐diabetic persons had adenomas (P=0.03). The proximal colon was investigated in 34 patients by DCBE and/or colonoscopy and the rate of proximal adenomas in patients with neoplastic findings in screening sigmoidoscopy was 5/34 (14.7%). Concerning the experience of screening sigmoidoscopy, 56 persons (93%) found bowel preparation easy and 4 unpleasant, 55 (92%) experienced either no or mild discomfort during the endoscopy whereas 5 found the examination painful; 59 people (98%) said that they would participate again in screening sigmoidoscopy.

Conclusions

In this study of screening sigmoidosopy, the first published in Finland, adenoma rate was 6.9%, advanced adenoma rate was 2.8% and cancer rate was 0.3%. Males had more hyperplastic polyps and advanced adenomas than females. Diabetic people had more adenomas than non‐diabetics. Experiences of the people screened were positive and nearly all said that they would participate again in screening sigmoidoscopy.
Outcome of argon beam and LASER ablation of large rectal adenomas
Authors: Adedeji O. A. , Allison S. I. , Varma J. S.
Published: March 2003

Objective

Endoscopic ablation of large rectal adenomas is being increasingly used as primary treatment. Despite the avoidance of general anaesthesia and the prevention of more major procedures, patients undergoing endoscopic ablation have the disadvantage of multiple treatment sessions and the lack of adequate tissue sample for complete histological study. The aim of this study was to analyse the outcome of all patients with large rectal polyps treated with endoscopic ablation.

Patients and methods

Between 1993 and 1998, 29 patients who underwent endoscopic ablation of large rectal adenoma were identified. All their case notes were analysed and information was collected on recurrence, treatment episodes, complications, the incidence of carcinoma and the necessity for further procedures.

Results

At a median 40 (range 4–67) months follow‐up, 41% of patients had recurrence of their adenoma and 14% had been diagnosed with adenocarcinoma. Only 24% of patients had been discharged while 21% were clear but were still under surveillance. Seven (24%) patients had complications, 6 stenosis and one severe bleeding. All stenosis occurred in patients who had more than 10 treatment sessions. In all, 31% of patients needed further endoanal or abdominal surgery and the median time to making this decision was 28 (range 4–66) months. There were no deaths.

Conclusion

Laser and argon ablation of large rectal adenomas has proved very disappointing. It should be reserved for patients who are unfit to undergo general anaesthesia.
Spotlight on a distant mirror – colorectal cancer surgery in a 20‐year period at a general hospital
Authors: Grabham J. A. , Britton D. C. , Umpleby H. , Tate J. J. T. , Chester J. F. , Holbrook A. G.
Published: March 2003

Background  A published audit of the management of colorectal cancer at a general hospital in the 1970s was available for comparison with a later audit at the same hospital in the 1990s.

Methods  Case note analysis.

Results  In the later audit, more cases were treated annually by an unchanged surgical team. The incidence of synchronous combined excision of the rectum, for rectal cancers suitable for resection, was halved, and that of anterior resection of the rectum (sphincter sparing, without a permanent stoma) increased almost threefold. The incidence of local recurrence in cases suitable for rectal surgery dropped from 17% to 9%, in spite of the change in the principal operation undertaken for this population. Outcomes associated with critical care improved as resources in this discipline became available. Overall survival figures were only improved by 6% in the20‐year period, reflecting a diagnosis of Dukes C tumours or worse in at least 45% of the stable population studied in both audits.

Conclusion  More resources are necessary in Great Britain to increase survival figures in this common cancer. Earlier diagnosis and more specialist management of the disease may allow us to emulate American and Swedish survival figures.