bluuebunny/crossref_metadata_2025 huggingface dataset:
Increased adherence and actin pedestal formation by dam‐deficient enterohaemorrhagic Escherichia coli O157:H7
Authors: Campellone Kenneth G. , Roe Andrew J. , Løbner‐Olesen Anders , Murphy Kenan C. , Magoun Loranne , Brady Michael J. , Donohue‐Rolfe Arthur , Tzipori Saul , Gally David L. , Leong John M. , Marinus M. G.
Published: February 2007

Enterohaemorrhagic Escherichia coli (EHEC) are highly infectious pathogens capable of causing severe diarrhoeal illnesses. As a critical step during their colonization, EHEC adhere intimately to intestinal epithelial cells and generate F‐actin ‘pedestal’ structures that elevate them above surrounding cell surfaces. Intimate adhesion and pedestal formation result from delivery of the EHEC type III secretion system (TTSS) effector proteins Tir and EspFU into the host cell and expression of the bacterial outer membrane adhesin, intimin. To investigate a role for DNA methylation during the regulation of adhesion and pedestal formation in EHEC, we deleted the dam (DNA adenine methyltransferase) gene from EHEC O157:H7 and demonstrate that this mutation results in increased interactions with cultured host cells. EHECΔdam exhibits dramatically elevated levels of adherence and pedestal formation when compared with wild‐type EHEC, and expresses significantly higher protein levels of intimin, Tir and EspFU. Analyses of GFP fusions, Northern blotting, reverse transcription polymerase chain reaction, and microarray experiments indicate that the abundance of Tir in the dam mutant is not due to increased transcription levels, raising the possibility that Dam methylation can indirectly control protein expression by a post‐transcriptional mechanism. In contrast to other dam‐deficient pathogens, EHECΔdam is capable of robust intestinal colonization of experimentally infected animals.
Identification of the lipooligosaccharide biosynthetic gene cluster from Mycobacterium marinum
Authors: Ren Huiping , Dover Lynn G. , Islam Salim T. , Alexander David C. , Chen Jeffrey M. , Besra Gurdyal S. , Liu Jun
Published: February 2007

Lipooligosaccharides (LOSs) are antigenic glycolipids that are present in some species of Mycobacterium including the Canetti strain of M. tuberculosis. The core LOS structures from several mycobacterial organisms have been established, but the biosynthetic pathways of LOSs remain unknown. In this study, we describe two transposon insertion mutants of M. marinum that exhibit altered colony morphology. Cell wall analysis reveals that the MRS1271 mutant is defective in the synthesis of LOS‐II, whereas the MRS1178 mutant accumulates an intermediate between LOS‐I and ‐II. The genetic lesions were localized to two genes, MM2309 and MM2332. MM2309 encodes a UDP‐glucose dehydrogenase that is involved in the synthesis of d‐xylose. MM2332 is predicted to encode a decarboxylase. These two genes and a previously identified losA gene are localized in a gene cluster likely to be involved in the biosynthesis of LOSs. Our results also show that LOSs play an important role in sliding motility, biofilm formation, and infection of host macrophages. Taken together, our studies have identified, for the first time, a LOS biosynthetic locus. This is an important step in assessing the differential distribution of LOSs among Mycobacterium species and understanding the role of LOSs in mycobacterial virulence.
The response regulator PmrA is a major regulator of the icm/dot type IV secretion system in Legionella pneumophila and Coxiella burnetii
Authors: Zusman Tal , Aloni Gali , Halperin Einat , Kotzer Hani , Degtyar Elena , Feldman Michal , Segal Gil
Published: February 2007

Legionella pneumophila and Coxiella burnetii have been shown to utilize the icm/dot type IV secretion system for pathogenesis and recently a large number of icm/dot‐translocated substrates were identified in L. pneumophila. Bioinformatic analysis has revealed that 13 of the genes encoding for L. pneumophila‐translocated substrates and five of the C. burnetii icm/dot genes, contain a conserved regulatory element that resembles the target sequence of the PmrA response regulator. Experimental analysis which included the construction of a L. pneumophila pmrA deletion mutant, intracellular growth analysis, comparison of gene expression between L. pneumophila wild type and the pmrA mutant, construction of mutations in the PmrA conserved regulatory element, controlled expression studies as well as mobility shift assays, demonstrated the direct relation between the PmrA regulator and the expression of L. pneumophila icm/dot‐translocated substrates and several C. burnetii icm/dot genes. Furthermore, genomic analysis identified 35 L. pneumophila and 68 C. burnetii unique genes that contain the PmrA regulatory element and few of these genes from L. pneumophila were found to be new icm/dot‐translocated substrates. Our results establish the PmrA regulator as a fundamental regulator of the icm/dot type IV secretion system in these two bacteria.
Limited tolerance towards folded elements during secretion of the autotransporter Hbp
Authors: Jong Wouter S. P. , Ten Hagen‐Jongman Corinne M. , Den Blaauwen Tanneke , Jan Slotboom Dirk , Tame Jeremy R. H. , Wickström David , De Gier Jan‐Willem , Otto Ben R. , Luirink Joen
Published: February 2007

Many virulence factors secreted by pathogenic Gram‐negative bacteria belong to the autotransporter (AT) family. ATs consist of a passenger domain, which is the actual secreted moiety, and a β‐domain that facilitates the transfer of the passenger domain across the outer membrane. Here, we analysed folding and translocation of the AT passenger, using Escherichia coli haemoglobin protease (Hbp) as a model protein. Dual cysteine mutagenesis, instigated by the unique crystal structure of the Hbp passenger, resulted in intramolecular disulphide bond formation dependent on the periplasmic enzyme DsbA. A small loop tied off by a disulphide bond did not interfere with secretion of Hbp. In contrast, a bond between different domains of the Hbp passenger completely blocked secretion resulting in degradation by the periplasmic protease DegP. In the absence of DegP, a translocation intermediate accumulated in the outer membrane. A similar jammed intermediate was formed upon insertion of a calmodulin folding moiety into Hbp. The data suggest that Hbp can fold in the periplasm but must retain a certain degree of flexibility and/or modest width to allow translocation across the outer membrane.
An experimentalist's guide to computational modelling of the Min system
Authors: Kruse Karsten , Howard Martin , Margolin William
Published: February 2007

Spatio‐temporal oscillations of the Min proteins are essential for selecting the cell division site in Escherichia coli. These oscillations are a key example of a biological phenomenon that can only be understood on a systems level rather than on the level of its individual components. Here, we review the key concepts that mathematical modelling has added to our understanding of the Min system. While several different mechanisms have been proposed, in all cases the oscillations emerge from a dynamic instability of a uniform protein distribution. To generate this instability, however, the various mechanisms rely on different features of Min protein interactions and transport. We critically evaluate these mechanisms in light of recent experimental evidence. We also review the effects of fluctuations caused by low cellular concentration of Min proteins, and describe how stochastic effects may potentially influence Min protein dynamics.
MerR family transcription activators: similar designs, different specificities
Authors: Hobman Jon L.
Published: February 2007

Living organisms use metals for a variety of essential functions, and face the problems of how to acquire and regulate the intracellular levels of those metals they need, differentiate between essential and toxic metals, and remove from the cell or detoxify metals that are toxic. In bacteria, cytoplasmic metal ion responsive transcriptional regulators are important in regulating the expression of genes involved in metal ion homeostasis and efflux systems. The MerR family of transcriptional activators are metal sensing regulators that are found in different bacteria and have a common design, but have evolved to recognize and respond to different metals. In this issue of Molecular Microbiology, work by Checa and colleagues describes for the first time a gold‐specific MerR family regulator named GolS from Salmonella enterica serovar Typhimurium that controls the production of an efflux pump and a metal chaperone protein that confer resistance to Au salts.
Specificity determinants of conjugative DNA processing in the Enterococcus faecalis plasmid pCF10 and the Lactococcus lactis plasmid pRS01
Authors: Chen Yuqing , Staddon Jack H. , Dunny Gary M.
Published: February 2007

The DNA‐processing region of the Enterococcus faecalis pheromone‐responsive plasmid pCF10 is highly similar to that of the otherwise unrelated plasmid pRS01 from Lactococcus lactis. A transfer‐proficient pRS01 derivative was unable to mobilize plasmids containing the pCF10 origin of transfer, oriT. In contrast, pRS01 oriT‐containing plasmids could be mobilized by pCF10 at a low frequency. Relaxases PcfG and LtrB were both capable of binding to single‐stranded oriT DNAs; LtrB was highly specific for its cognate oriT, whereas PcfG could recognize both pCF10 and pRS01 oriT. However, pcfG was unable to complement an ltrB insertion mutation. Genetic analysis showed that pcfF of pCF10 and ltrF of pRS01 are also essential for plasmid transfer. Purified PcfF and LtrF possess double‐stranded DNA binding activities for the inverted repeat within either oriT sequence. PcfG and LtrB were recruited into their cognate F–oriT DNA complex through direct interactions with their cognate accessory protein. PcfG also could interact with LtrF when pCF10 oriT was present. In vivo cross‐complementation analysis showed that ltrF partially restored the pCF10ΔpcfF mutant transfer ability when provided in trans, whereas pcfF failed to complement an ltrF mutation. Specificity of conjugative DNA processing in these plasmids involves both DNA–protein and protein–protein interactions.
Crystal structure of a novel prokaryotic Ser/Thr kinase and its implication in the Cpx stress response pathway
Authors: Zheng Jimin , He Chunhua , Singh Vinay Kumar , Martin Nancy L. , Jia Zongchao
Published: February 2007

The Cpx signalling system of Escherichia coli and Salmonella enterica senses extracytoplasmic stress and controls expression of factors that allow the bacterium to adapt to these stressors and thereby enhance survival. Many of the Cpx‐responsive genes products are of unknown function. We determined the crystal structure of one of these gene products, called YihE in E. coli, which exhibits a eukaryotic kinase fold. Functional assays established that both YihE and the S. enterica YihE homologue, RdoA, undergo autophosphorylation and phosphorylate protein substrates at Ser/Thr residues in vitro, demonstrating that YihE/RdoA is a novel Ser/Thr protein kinase in prokaryotic cells. Phenotypic analysis of yihE/rdoA null strains indicates that this kinase is most abundant in stationary phase, and is important for long‐term cell survival and for expression of surface appendages in both a Cpx‐independent and ‐dependent manner. YihE/RdoA is therefore a previously unknown kinase component of a new type of bacterial phosphorelay mechanism, adding kinase activity as another response to the Cpx sensing system that functions to maintain cellular homeostasis.
Long‐term functional outcome of macular hole surgery correlated to optical coherence tomography measurements
Authors: Haritoglou Christos , Neubauer Aljoscha S , Reiniger Ingrid W , Priglinger Siegfried G , Gass Carolin A , Kampik Anselm
Published: February 2007

Abstract

Objective:  Evaluation of long‐term functional outcome after macular hole surgery and its correlation with postoperative optical coherence tomography (OCT).

Methods:  Before and after surgery a complete clinical examination and OCT were performed in 38 patients. Best corrected postoperative visual acuity (VA) was correlated to the following OCT parameters: preoperative base and minimum diameter of the hole, hole height, hole form factor, retinal thickness and nerve‐fibre layer measurements postoperatively, postoperative foveal contour, appearance of retinal pigment epithelium layer and photoreceptor layer.

Results:  Over a mean follow up of 67 months, VA improved significantly (P = 0.01). Retinal thickness and retinal thickness and nerve‐fibre layer measurements of the operated eye did not differ from fellow eye. A negative correlation was seen between final VA and preoperative base diameter of the hole (r = −0.41, P = 0.02) and hole height (r = −0.45, P = 0.01). The correlation between hole form factor values and final VA (r = 0.36, P = 0.04) was weak. Appearance of the photoreceptor band was the only OCT parameter significantly correlating with final VA (r = −0.42, P = 0.01) and explaining the observed increase (r = −0.32, P = 0.05) in VA.

Conclusion:  Appearance of the photoreceptor layer on postoperative OCT correlates to functional outcome and may help to explain cases of unsatisfactory postoperative VA despite successful hole closure.
Alterations of retinal pigment epithelium in central serous chorioretinopathy
Authors: Hirami Yasuhiko , Tsujikawa Akitaka , Sasahara Manabu , Gotoh Norimoto , Tamura Hiroshi , Otani Atsushi , Mandai Michiko , Yoshimura Nagahisa
Published: February 2007

Abstract

Background:  To examine with en face optical coherence tomography (OCT) the alterations of retinal pigment epithelium (RPE) in central serous chorioretinopathy (CSC) and their role in the pathophysiology of CSC.

Methods:  We examined retrospectively 30 consecutive eyes of 30 patients with various phases of CSC. All patients underwent fluorescein angiography, indocyanine green angiography, and en face and longitudinal OCT examinations.

Results:  Of 25 eyes with acute CSC, en face OCT showed RPE abnormalities in 22 eyes (88%) with pigment epithelial detachment (PED) in nine eyes (36%) and a small bulge of RPE in the posterior pole in 15 eyes (60%). Of four eyes with chronic CSC, OCT showed PED in one eye (25%) and a small bulge of RPE in other three eyes (75%). Of 29 eyes with acute or chronic CSC, fluorescein angiography showed characteristic pinpoint leakage in 20 eyes (69%). Of these 20 eyes, a leaking point was located within PEDs in five eyes (25%) and was consistent with the bulge of RPE in nine eyes (45%). With indocyanine green angiography, 28 (97%) eyes showed choroidal vascular hyperpermeability. Ten of the 11 eyes with PED (91%) showed PED within the areas of choroidal vascular hyperpermeability. Sixteen of the 18 eyes with a bulge of RPE (89%) showed the bulge within areas of choroidal vascular hyperpermeability. The one eye in the quiescent CSC exhibited multiple small PEDs within the areas of choroidal vascular hyperpermeability by en face OCT.

Conclusions:  En face OCT enables us to detect alterations of RPE in eyes with CSC. Most alterations of RPE were associated with choroidal abnormalities.
Blepharophimosis–ptosis–epicanthus inversus syndrome: objective analysis of surgical outcome in patients from a single unit
Authors: Taylor Alexandra , Strike Paul W , Tyers Anthony G
Published: February 2007

Abstract

Background:  The aim was to objectively assess surgical outcome in blepharophimosis–ptosis–epicanthus inversus syndrome (BPES).

Method:  Retrospective review of 14 consecutive patients with BPES. Mustardé double z plasty (at about age 4) and autogenous fascia lata Crawford brow suspension (9–12 months later) were used in all. One consultant performed all operations. Patient photographs were scanned and magnified for analysis. Preoperative and postoperative intercanthal distance, vertical palpebral aperture and cosmetic outcome were measured. Values were converted into ratios.

Results:  Bilateral (mildly asymmetrical) ptosis and symmetrical epicanthic folds were found in all preoperatively. Seventy‐one per cent had severe folds. Preoperative intercanthal distance ratio range was 1.26–1.60 (non‐BPES = 1.0). Median reduction post surgery was 26% (P = 0.001, Wilcoxon’s signed ranks test). Patients with largest preoperative ratio displayed greatest correction (P = 0.029). Mustardé technique completely abolished all epicanthic folds and unmasked prominent caruncles in all. Fifty per cent had mild scarring postoperatively in the medial canthal region. Median change in marginal reflex distance ratio (right) = 22.2% (P = 0.012), left = 18.2% (P = 0.008), Wilcoxon’s signed ranks tests. Postoperatively all had formed eyelid creases with improved upper lid position symmetry.

Conclusions:  This is the first known study objectively assessing surgical outcome in BPES. Mustardé double z plasty and Crawford autogenous fascia lata brow suspension are an effective surgical combination in the treatment of this syndrome, with overall cosmetic benefit.
Traumatic intralenticular abscess: a case series
Authors: Salman Amjad , Parmar Pragya , Philip Vinitha R , Thomas Philip A , Jesudasan Christdas AN
Published: February 2007

Abstract

Purpose:  To report the clinical presentation, management and outcome of eyes with traumatic intralenticular abscess.

Methods:  In this interventional case series, records of eight patients (eight eyes) with intralenticular abscess developing following trauma were reviewed. All patients underwent extracapsular cataract extraction with intracameral antibiotics with or without pars plana vitrectomy. Main outcome measures studied were resolution of infection and final visual outcome.

Results:  Lens abscess developed in six eyes following penetrating injury and in two eyes following intraocular penetration of caterpillar hair. Gram positive cocci were cultured from the lens aspirate in five eyes and Staphylococcus epidermidis was the most common organism isolated. Cataract extraction resulted in control of the infection in all eyes and seven eyes (87.5%) had a favourable visual outcome.

Conclusion:  Early lens extraction with intracameral antibiotics in eyes with intralenticular abscess allows control of infection with good visual outcome.
SKIN GRAFT FAILURE IS PREDICTED BY WAIST–HIP RATIO: A MARKER FOR METABOLIC SYNDROME
Authors: Penington Anthony J. , Morrison Wayne A.
Published: February 2007

Background:  Obesity is recognized as a risk factor for wound healing problems in surgery, but the reason for this increased risk is unclear. It is now recognized that truncal obesity, as measured by either the waist circumference or the waist–hip ratio (WHR), is a strong risk factor for an array of metabolic problems termed ‘metabolic syndrome’. It was suggested that increased WHR would be a sensitive marker of obesity‐related wound healing impairment and therefore would predict skin graft failure.

Method:  Consecutive patients undergoing full‐thickness skin graft of the head and neck region in a private practice setting were enrolled prospectively. The body mass index and WHR were recorded at the time of surgery and skin graft take was assessed at 1–2 weeks.

Results:  There was a strong correlation between increased WHR and graft failure; all four patients in the study having a WHR greater than 1 showed partial or total graft loss compared with only one patient having a 10% loss in the remainder (r = −0.76, P = 0.002).

Conclusion:  There is a strong correlation between truncal obesity as measured by the WHR and skin graft failure. WHR or waist circumference should be considered as a preoperative assessment tool in identifying patients at risk of surgical complications.
CHANGES IN THE ABDOMINAL FAT DISTRIBUTION AFTER GASTRECTOMY: COMPUTED TOMOGRAPHY ASSESSMENT
Authors: Yoon Dae Young , Kim Hyeon Kyu , Kim Ju Ae , Choi Chul Soon , Yun Eun Joo , Chang Suk Ki , Lee Yu‐Jin , Park Chan Heun
Published: February 2007

Background:  We investigated the postoperative changes in visceral fat, as compared with subcutaneous fat in patients who underwent total gastrectomy (TG) or subtotal gastrectomy (STG).

Methods:  Thirty‐eight patients of gastric cancer who underwent abdominal and pelvic computed tomography scans before and after STG (n = 28) or TG (n = 10) were examined. The volumes of the total, visceral and subcutaneous adipose tissues (TAT, VAT and SAT, respectively) were calculated in each scan using the multislice method. Changes between the preoperative data and results obtained at 6 and 12 months after surgery were evaluated.

Results:  In the first 6 months, there were significant decreases in TAT, VAT and SAT values in the TG (−2424 ± 1309, −1535 ± 1056 and −889 ± 613 cm3, respectively) and STG (−1590 ± 1309, −1024 ± 645, and −578 ± 659 cm3, respectively) groups. From 6 to 12 months after surgery, a further significant reduction in VAT (−351 ± 196 cm3) in the TG group and significant regains in TAT and SAT (850 ± 1205 and 757 ± 1032 cm3, respectively) in the STG group were observed. The ratio of VAT to SAT calculated in both groups decreased continuously in all periods of observation.

Conclusion:  Patients who underwent gastrectomy lost TAT, VAT and SAT during the postoperative period up to 6 months and the decrease in VAT was greater and more persistent than the decrease in SAT, particularly in the TG group.
MEDULLARY THYROID CARCINOMA: A 20‐YEAR EXPERIENCE FROM A CENTRE IN SOUTH INDIA
Authors: Finny Philip , Jacob Jubbin J , Thomas Nihal , Philip Jim , Rajarathnam Simon , Oommen Regi , Nair Aravindan , Seshadri Mandalam S
Published: February 2007

Background:  Management of medullary thyroid carcinoma (MTC) remains controversial despite many advances over the past five decades. We attempt to review the presentation, management and prognosis of MTC at our institution over the last two decades.

Methods:  We conducted a retrospective review of the records of 40 patients with MTC over a period of 20 years.

Results:  Ten patients had hereditary MTC and 30 had sporadic MTC. The mean age of presentation was 41 years. Sixty‐five per cent of the patients had a definite thyroid swelling and 43% had lymphadenopathy at the time of presentation. Total thyroidectomy with a central neck dissection was carried out in 82.5% of patients. Adjuvant therapy was given in 75% of patients because of extensive/residual disease. Postoperative hypercalcitoninaemia was seen 73% of patients. 131I metaiodobenzylguanidine scanning was carried out in 16 patients with persistent hypercalcitoninaemia; the uptake was positive in 10 and negative in 6, indicating a positivity of 62%.

Conclusion:  Medullary thyroid carcinoma accounts for 2.5% of thyroid carcinomas. There is a small male preponderance. In our series 131I metaiodobenzylguanidine scan had a better positivity than what has been reported in the published work. Persistent postoperative hypercalcitoninaemia was associated with a poorer prognosis that did not reach statistical significant.
RISK FACTORS FOR POSTOPERATIVE PULMONARY COMPLICATIONS IN UPPER ABDOMINAL SURGERY
Authors: Kanat Fikret , Golcuk Ayse , Teke Turgut , Golcuk Murat
Published: February 2007

Background:  Pulmonary complications are the most frequent cause of postoperative morbidity and mortality in upper abdominal surgery (UAS). We aimed to examine the influence of possible preoperative, operative and postoperative risk factors on the development of early postoperative pulmonary complications (POPC) after UAS.

Methods:  A prospective study of 60 consecutive patients was conducted who underwent elective UAS in general surgical unit. Each patient’s preoperative respiratory status was assessed by an experienced chest physician using clinical examination, chest radiographs, spirometry and blood gas analysis . Anaesthetical risks, surgical indications, operation time, incision type, duration of nasogastric catheter and mobilization time were noted. Forty‐eight hours after the operation, pulmonary examinations of the patients were repeated.

Results:  Postoperative pulmonary complications were observed in 35 patients (58.3%). The most common complication was pneumonia, followed by pneumonitis, atelectasis, bronchitis, pulmonary emboli and acute respiratory failure. The presence of preoperative respiratory symptoms and the spirometric parameter of forced expiratory volume in 1 s/forced vital capacity were the most valuable risk factors for early prediction of POPC. The sensitivity, specificity and diagnostic efficiency of the presence of preoperative respiratory symptoms in the POPC prediction were 70, 61 and 66%, respectively.

Conclusion:  We recommend a detailed pulmonary examination and spirometry in patients who will undergo UAS by chest physicians to identify the patients at high risk for POPC, to manage respiratory problems of the patients before surgery and also to help surgeons to take early measures in such patients before a most likely POPC occurrence. Improvement of lung function in those patients at risk for POPC before operation may decrease morbidity in surgical patients.
EMERGENCY THORACIC SURGERY FOR PENETRATING, NON‐MEDIASTINAL TRAUMA
Authors: Loogna Peter , Bonanno Fabrizio , Bowley Douglas M. , Doll Dietrich , Girgensohn Roland , Smith Martin D. , Glapa Miriam , Degiannis Elias
Published: February 2007

Background:  Penetrating thoracic injury is commonly found in South Africa. A review of our recent experience was undertaken to assess the effectiveness of our protocols for this type of injury.

Methods:  A retrospective study of 61 consecutive patients with penetrating, non‐mediastinal trauma to the chest was conducted over 32 months at a single trauma unit. Patient details, mechanism of injury, operative procedure and in‐hospital mortality and morbidity rates were recorded.

Results:  Two thousand and nineteen patients presented with penetrating chest injury of which 61 patients (3%) underwent thoracic surgery for non‐mediastinal injury. Twenty‐six patients had stab wounds and 35 had gunshot wounds. Overall mortality was 17/61 (28%). Gunshot wounds were more likely to result in death than stab wounds (relative risk = 11.9; 95% confidence interval 1.7–84.0) and thoracoabdominal injury resulted in death more commonly than chest injury (relative risk = 4.8; 95% confidence interval 2.2–10.3) resulted in death.

Conclusion:  Penetrating chest injury is common and most patients can be managed without formal thoracic surgical intervention. However, the patients who do merit surgical intervention have a relatively high mortality and a rapid and practised operative approach is required to achieve acceptable results.
RISK FACTORS FOR MICROVASCULAR TUMOUR THROMBI IN HEPATOCELLULAR CARCINOMA: A UNIVARIATE AND MULTIVARIATE ANALYSIS
Authors: Ibrahim Salleh , Roychowdhury Anupama , Khoon Hean Tay
Published: February 2007

Background:  Microvascular tumour thrombi in hepatocellular carcinoma (HCC) predict poor outcome and are a risk factor for intrahepatic and extrahepatic metastases. Survival after liver transplantation is also affected. Our aim was to predict the risk factors for the presence of microvascular tumour thrombi.

Methods:  Seventy‐six patients who had undergone hepatectomy for HCC in our hospital were included in a retrospective analysis from a prospective database.

Results:  Thirty‐one patients (40.8%; mean age 50.7 ± 12.2 years, P < 0.021) had microvascular tumour thrombi (group T) and 54 patients (group NT; mean age 58.6 ± 15.4 years) did not. Using logistic regression analysis, we found that more than one HCC nodule, a large tumour, chronic hepatitis C infection and high serum aspartate aminotransferaselevels were significant risk factors for microvascular tumour thrombi. Age, preoperative serum bilirubin level and sex were not significant risk factors.

Conclusion:  Patients with chronic hepatitis C infection having multiple HCC nodules, large tumour size and high preoperative aspartate aminotransferase levels are at high risk for microvascular tumour thrombi.
TWO‐STAGE BRACHIOBASILIC ARTERIOVENOUS FISTULA FOR CHRONIC HAEMODIALYSIS ACCESS
Authors: Francis David M. A. , Lu Yufan , Robertson Amanda J. , Millar Robert J. , Amy Jayne
Published: February 2007

Background: Many haemodialysis patients are unable to have or maintain distal upper limb arteriovenous (AV) fistulas because of inadequate veins or arteries and therefore require more proximal access. We have reviewed our experience with a two‐stage brachiobasilic AV haemodialysis fistula fashioned in the arm.

Methods: Ninety‐one brachiobasilic AV fistulas were fashioned in 87 patients between August 1999 and October 2004. Four AV fistulas failed because of early thrombosis. The second stage ‘superficialization’ was carried out at a median (range) of 73 days (32–1827 days) after fistula formation and involved mobilizing the arterialized basilic vein through a curved longitudinal incision on the anteromedial aspect of the arm and transposing it beneath the skin incision.

Results: Primary and secondary patency rates were 87 and 89%, respectively, at 1 year and 78 and 84%, respectively, at 2 years. Early complications included infection (3%) and haemorrhage (4%) and late complications included thrombosis (15%) and stenosis (14%).

Conclusion: The two‐stage superficialized brachiobasilic AV fistula described in this article has good patency. The operative techniques are straightforward, have relatively low complication rates and result in a large‐diameter fistula on the anteromedial aspect of the arm allowing easy and painless cannulation for haemodialysis.
COMPUTED TOMOGRAPHY IN THE ASSESSMENT OF SUSPECTED LARGE BOWEL OBSTRUCTION
Authors: Beattie Garth C. , Peters Robert T. , Guy Susanne , Mendelson Richard M.
Published: February 2007

Background:  The aim of this study was to assess the efficacy of computed tomography (CT) scanning in the diagnosis of acute large bowel obstruction.

Methods:  Forty‐four patients (22 men; 22 women, ages 39–94 years, mean 71 years) with clinical features and abdominal radiographic findings suggesting acute large bowel obstruction (LBO) or pseudo‐obstruction were examined with CT. Supine scans were obtained with i.v. contrast medium (unless contraindicated), but (in the majority) without oral contrast. Additional prone and/or decubitus scans were obtained in 33 patients when clarification of a possible transition point on the supine scan was required. CT diagnosis of LBO was made by finding a transition point ± mass. Final diagnosis was confirmed by surgery, further imaging and/or clinical course.

Results:  Twenty‐two patients had proven mechanical acute LBO of whom 18 had an obstructing carcinoma; 22 patients had no mechanical obstruction. Sensitivity, specificity, Positive Predictive Value, Negative Predictive Value of CT for diagnosis of mechanical LBO were each 91%. Positive and negative likelihood ratios were 10.1 and 0.1, respectively. There were two false‐negative CT scans, although one of these was reported as showing segmental mural thickening. A mass was identified on 14 of 17 patients with true‐positive CT, subsequently found to have carcinoma.

Conclusion:  Computed tomography with additional selective prone and/or decubitus scanning is highly effective in the diagnosis of mechanical LBO. It is suggested that it replace contrast enema as the initial imaging method.
ROLE OF ENDOSCOPIC ULTRASOUND IN STAGING UPPER GASTROINTESTINAL CANCERS
Authors: Jones D. Brian
Published: February 2007

The key clinical management points in this article are that (i) endoscopic ultrasound is the most accurate imaging method for local staging of oesophageal, gastric and pancreatic neoplasms; (ii) addition of fine‐needle aspiration biopsy to the technique is safe and well tolerated and increases diagnostic accuracy for nodal staging purposes; and (iii) endoscopic ultrasound ± fine‐needle aspiration has the capacity to influence significantly, the management of patients with malignancies of the upper gastrointestinal tract, particularly with respect to selection for surgery. The learning objectives were that at the end of this paper the reader should be able to (i) understand the usefulness and limitations of various imaging methods in the staging of upper gastrointestinal cancers; and (ii) incorporate the various imaging methods, particularly endoscopic ultrasound, into management algorithms for oesophageal cancer, gastric cancer, mucosa‐associated lymphoid tissue lymphomas, gastrointestinal stromal tumours, pancreatic cystic lesions and pancreatic cancer.
N‐ACETYLCYSTEINE IMPROVES INTESTINAL BARRIER IN PARTIALLY HEPATECTOMIZED RATS
Authors: Oz Sarpkaya , Okay Erdem , Karadenizli Aynur , Cekmen Mustafa B. , Ozdogan Haci K.
Published: February 2007

Background:  Translocating enteric bacteria play an important role in the development of infections following partial hepatectomy. The intestine itself is the first line of defence against bacterial translocation (BT). We investigated the effect of N‐acetylcysteine (NAC) on BT and the intestinal wall.

Methods:  We compared four groups of Sprague–Dawley male rats (eight in each group): sham, sham plus preoperative single dose of NAC, partial hepatectomy and partial hepatectomy plus preoperative single dose of NAC. Microorganism count in the tissues and the glutathione and malondialdehyte contents of the intestinal wall were studied at the end of the 24th hour.

Results:  Bacterial growth was observed in the spleen and mesenteric lymph nodes in the sham group. There was bacterial growth in all the samples of the partial hepatectomy group. Differences were significant except in atrial and portal blood counts. In the partial hepatectomy plus NAC treatment group, counts were significantly low in all, except atrial and portal blood samples. The malondialdehyte level in the intestinal wall was 35.38 ± 10.27 in the sham group, increasing significantly in the partial hepatectomy group (69.50 ± 21.48), and decreasing in the partial hepatectomy plus NAC treatment group (35.63 ± 14.12). Glutathione levels decreased significantly in the partial hepatectomy group and increased with preoperative single‐dose NAC.

Conclusion:  Partial hepatectomy resulted in oxidative disturbances in intestinal wall, which in turn gave rise to BT. Parenteral NAC protects the intestinal wall from oxidative injury and attenuates BT.
SACROCOCCYGEAL PILONIDAL DISEASE: SINOTOMY VERSUS EXCISIONAL SURGERY, A RETROSPECTIVE STUDY
Authors: Rabie M. Ezzedien , Al Refeidi Abdullah A. , Al Haizaee Abdullah , Hilal Saleh , Al Ajmi Hassan , Al Amri Abdul Aziz
Published: February 2007

Pilonidal disease is a disease of relatively young people, the exact aetiology of which is unknown. Treatment options vary from simple incision to complex flap procedures. Each method has its advocates and they all have a variable recurrence rate. The multiplicity of procedures testifies to the lack of an optimal treatment method. The objective of this study is to compare sinotomy, that is, simply laying the sinus open with the more popular radical surgery, where the sinus‐bearing tissues are excised. Patients who were admitted to Aseer Central Hospital, Saudi Arabia with a pilonidal sinus or abscess, in the period from April 1999 to January 2005, were identified. The medical records were reviewed and data related to the patient characteristics, disease process and the procedures carried out were noted. Identified patients were contacted by phone to check recurrence of the disease and their abidance to instructions regarding regular hair removal from the area. Eighty‐one patients were included in the study. The median age was 24.2 years (range 16–60 years). There were 9 women and 72 men. All procedures were carried out under general anaesthesia except sinotomy, which was carried out under general or local anaesthesia. The surgical procedure was incision and drainage of abscess in 16 cases (19.8%), excision with primary closure in 29 cases (35.8%), excision by the open method in 15 cases (18.5%), sinotomy in 14 cases (17.3%) and rhomboid flap construction in 8 cases (9.9%). The overall recurrence rate was 26.9%, and the mean hospital stay was 4.1 days. Sinotomy had a low recurrence rate (12.5%) and a short hospital stay (2.8 days). Sinotomy has the advantages of simplicity, the possibility of operating under local anaesthesia, with an acceptable recurrence rate. We recommend sinotomy for pilonidal sinus and abscess alike, both in primary and recurrent cases.
COMPLETE TRACHEAL STENOSIS FOLLOWING PERCUTANEOUS TRACHEOSTOMY
Authors: Lim Hou‐Kiat , Tykocinski Michael , Tudge Steven , Thomson Peter
Published: February 2007

Percutaneous tracheostomy is an effective method of airway management in the critically ill patient, avoiding an open exposure of the trachea. This method is time and cost‐efficient and is used in many intensive care units. However, we would like to draw attention to one serious potential complication of this technique. This case report describes a case of complete tracheal stenosis above the level of tracheostoma as a direct result of the procedure. The aetiology of the stenosis as well as the surgical and postoperative managements is discussed.
ISOLATED FRACTURE OF THE CORACOID PROCESS ASSOCIATED WITH UNSTABLE SHOULDER
Authors: Subramanian Ashok Sridhara , Khalik Mohammed A. , Shah Mian M.
Published: February 2007

We report on an unusual case where a seemingly trivial injury in a patient on immunosupressant therapy led to fracture of the coracoid and an unstable shoulder with a subscapularis tear. This was managed with open reduction and internal fixation. One year postoperatively, the patient had regained full function and range of motion.
The wealth of species: ecological communities, complex systems and the legacy of Frank Preston
Authors: Nekola Jeffrey C. , Brown James H.
Published: February 2007

General statistical patterns in community ecology have attracted considerable recent debate. Difficulties in discriminating among mathematical models and the ecological mechanisms underlying them are likely related to a phenomenon first described by Frank Preston. He noted that the frequency distribution of abundances among species was uncannily similar to the Boltzmann distribution of kinetic energies among gas molecules and the Pareto distribution of incomes among wage earners. We provide additional examples to show that four different ‘distributions of wealth’ (species abundance distributions, species–area and species–time relations, and distance decay of compositional similarity) are not unique to ecology, but have analogues in other physical, geological, economic and cultural systems. Because these appear to be general statistical patterns characteristic of many complex dynamical systems they are likely not generated by uniquely ecological mechanistic processes.
Eating yourself sick: transmission of disease as a function of foraging ecology
Authors: Hall Spencer R. , Sivars‐Becker Lena , Becker Claes , Duffy Meghan A. , Tessier Alan J. , Cáceres Carla E.
Published: February 2007

Species interactions may profoundly influence disease outbreaks. However, disease ecology has only begun to integrate interactions between hosts and their food resources (foraging ecology) despite that hosts often encounter their parasites while feeding. A zooplankton–fungal system illustrated this central connection between foraging and transmission. Using experiments that varied food density forDaphniahosts, density of fungal spores and body size ofDaphnia, we produced mechanistic yet general models for disease transmission rate based on broadly applicable components of feeding biology. Best performing models could explain why prevalence of infection declined at high food density and rose sharply as host size increased (a pattern echoed in nature). In comparison, the classic mass‐action model for transmission performed quite poorly. These foraging‐based models should broadly apply to systems in which hosts encounter parasites while eating, and they will catalyse future integration of the roles ofDaphniaas grazer and host.
A reply to Baldwin: critique does not weaken major conclusions
Authors: Adler Lynn S. , Wink Michael , Distl Melanie , Lentz Amanda J.
Published: February 2007

Baldwin's critique raises some valid points. However, none invalidates our main findings of correlations between leaf and floral defences, and induction of nectar alkaloids. We believe our study successfully demonstrated linkages between leaf and floral traits, and we hope it inspires further research in multiple systems and settings.
Technical comment on Adler et al. (2006): experimental design compromises conclusions
Authors: Baldwin Ian T.
Published: February 2007

The conclusion that herbivory induces ‘alkaloids’ in nectar but not in leaves, is likely an artefact of using pot‐bound plants and analytical procedures that only measure anabasine, a minor alkaloid representing 0.3% of the total alkaloids produced by Nicotiana tabacum.
A 10‐year retrospective analysis of pregnancy outcome in pregestational Type 2 diabetes: comparison of insulin and oral glucose‐lowering agents
Authors: Ekpebegh C. O. , Coetzee E. J. , Van Der Merwe L. , Levitt N. S.
Published: February 2007

Aims  To review the use of oral glucose‐lowering agents (OGLA) in pregnant women with Type 2 diabetes mellitus.

Methods  Retrospective analysis of outcomes and their predictors in singleton pregnancies ≥ 24 weeks managed at Groote Schuur hospital, Cape Town, South Africa from 1991 to 2000. There were 379 pregnancies, subdivided into three groups according to therapy: OGLA alone, converted from OGLA to insulin, insulin alone or converted from diet alone to insulin. The OGLA used were metformin and glibenclamide.

Results  Mean glycated haemoglobin (HbA1c) was similar at booking and throughout pregnancy in all groups. In the OGLA alone, converted from OGLA to insulin and insulin alone/converted from diet alone to insulin groups, fetal anomaly rates were comparable: 5.7%, 2.0% and 0.0%, P = 0.2, respectively; whereas perinatal mortality rates (per 1000 births) were: 125, 28, 33, P = 0.003, respectively. Booking HbA1c was independently associated with fetal anomaly [odds ratio (OR) 1.48; 95% confidence interval (CI) 1.11, 1.97; P = 0.006]. The specific OGLA used in the first trimester was not associated with the occurrence of fetal anomaly. Last HbA1c (OR 1.65; 95% CI 1.16, 2.42; P = 0.005) and fetal anomaly (OR 15.18; 95% CI 2.43, 93.37; P = 0.005) were independently associated with perinatal mortality. Conversion from OGLA to insulin was protective for perinatal mortality compared with OGLA alone treatment (OR 0.220; 95% CI 0.061, 0.756; P = 0.024). No perinatal mortality was observed in women on metformin alone.

Conclusions  These data suggest that metformin and glibenclamide are not teratogenic but that it is advisable to replace OGLA, in particular glibenclamide, with insulin when women book for pregnancy care to reduce perinatal mortality rates.
Decreased high‐molecular‐weight adiponectin in gestational diabetes: implications for the pathophysiology of Type 2 diabetes
Authors: Retnakaran R. , Connelly P. W. , Maguire G. , Sermer M. , Zinman B. , Hanley A. J. G.
Published: February 2007

Aims  Low serum concentrations of the insulin‐sensitizing protein adiponectin predict the development of incident Type 2 diabetes (T2DM). It has recently emerged that the anti‐diabetic activity of adiponectin may be mediated by its high‐molecular‐weight (HMW) isoform, circulating levels of which are decreased in T2DM. The relevance of decreased HMW adiponectin to incident T2DM, however, has not been assessed. Since gestational diabetes (GDM) identifies a population of young women at high risk of future T2DM (i.e. representing an early stage in the natural history of the disease), we sought to determine if decreased HMW adiponectin is a feature of GDM.

Methods  HMW and total adiponectin were measured in 121 women at the time of oral glucose tolerance testing (OGTT) in late pregnancy, following an abnormal glucose challenge test. Based on the OGTT, there were 41 women with and 80 without GDM.

Results  Median HMW adiponectin concentration was lower in women with GDM (3.5 µg/ml) than in those without GDM (5.5 µg/ml) (P < 0.0001). After full adjustment for covariates, mean HMW adiponectin remained significantly lower in women with GDM compared with their peers (3.6 vs. 5.3 µg/ml, P = 0.0035). HMW adiponectin was positively associated with insulin sensitivity (ISOGTT) (r = 0.38, P < 0.0001) and pancreatic B‐cell function [insulin secretion‐sensitivity index (ISSI)] (r = 0.33, P = 0.0002) and inversely related to blood glucose levels, including area‐under‐the‐glucose‐curve during the OGTT (AUCglucose) (r = −0.31, P = 0.0007). On separate multiple linear regression analyses, HMW adiponectin emerged as an independent determinant of AUCglucose, ISOGTT and ISSI, respectively, mirroring the relationships of total adiponectin.

Conclusions  HMW adiponectin is significantly decreased in women with GDM. Deficiency of HMW adiponectin may be an early event in the natural history of T2DM.
Secular trends, disease maps and ecological analyses of the incidence of childhood onset Type 1 diabetes in Northern Ireland, 1989–2003
Authors: Cardwell C. R. , Carson D. J. , Patterson C. C.
Published: February 2007

Aims  To investigate secular trends in the incidence of Type 1 diabetes in Northern Ireland over the period 1989–2003. To highlight geographical variations in the incidence of Type 1 diabetes by producing disease maps and to compare incidence rates by relevant area characteristics.

Methods  New cases of Type 1 diabetes in children aged 0–14 years in Northern Ireland were prospectively registered from 1989 to 2003. Standardized incidence rates were calculated and secular trends investigated. Bayesian methodology was used to produce maps of disease incidence using small geographical areas (582 electoral wards). Ecological analyses were conducted using Poisson regression to investigate incidence rates by area characteristics at a finer geographical subdivision (5022 census output areas).

Results  In Northern Ireland during 1989–2003, there were 1433 new cases, giving a directly standardized incidence rate of 24.7 per 100 000 person‐years. This incidence rate increased by a mean of 4.2% per annum. Disease maps highlighted higher incidence rates in the predominately rural north‐east of the province and lower incidence rates in the urban areas around Belfast in the east and Derry in the north‐west of the province. Ecological analysis identified higher incidence in rural areas (P < 0.001), areas with low migration rates (P = 0.002), affluent areas (P < 0.0001), sparsely populated areas (P = 0.0001) and remote areas (P = 0.005).

Conclusions  In Northern Ireland the incidence of Type 1 diabetes is increasing. The observed higher incidence in rural, affluent, sparsely populated and remote areas may reflect a reduced or delayed exposure to infections in these areas.