Switch-on luminescent sensing of unlabelled bacterial lectin by terbium(III) glycoconjugate systems

Interactions of lectins with glycoconjugate-terbium(III) self-assembly complexes lead to sensing through enhanced lanthanide luminescence. This glycan-directed sensing paradigm detects an unlabelled lectin (LecA) associated with pathogen P. aeruginosa in solution, without any bactericidal activity. Further development of these probes could have potential as a diagnostic tool.

Formation of lanthanide luminescent di-metallic helicates in solution using a bis-tridentate (1,2,3-triazol-4-yl)-picolinamide (tzpa) ligand

The chiral bis-tridentate (1,2,3-triazol-4-yl)-picolinamide (tzpa) ligand 1 was used in the formation of lanthanide di- and triple stranded di-metallic helicates in acetonitrile solution, where the changes in the ground and the Tb(III) excited state properties were used to monitor the formation of these supramolecular structures in situ under kinetic control.

Carbohydrate‐functionalized triazolylidene iridium complexes: hydrogenation catalysis in water with asymmetric induction

Two sets of carbohydrate‐NHC hybrid iridium complexes were synthesised in order to combine properties of carbohydrates and triazolylidene (trz) ligands in organometallic catalysis. One set features a direct trz linkage to the anomeric carbohydrate carbon, while the second set is comprised of an ethyl linker between the two functional units. Deprotection of the carbohydrate afforded hybrid complexes that efficiently catalyse the direct hydrogenation of ketones in water. The catalytic activity of the hybrid complexes was influenced by the pH of the aqueous medium and surpassed the activity of carbohydrate‐free or acetyl‐protected analogues (>90 % vs 13 % yield). While no enantiomeric induction was observed for the ethyl‐linked hybrids, a moderate enantiomeric excess (ee) was induced by the directly linked systems. Moreover, these carbohydrate‐trz hybrid complexes displayed mixed inhibitory activity towards a glycosidase from H. orenii that contain a glucose binding site.

Ruthenium-centred btp glycoclusters as inhibitors for Pseudomonas aeruginosa biofilm formation

Carbohydrate-decorated clusters (glycoclusters) centred on a Ru(ii) ion were synthesised and tested for their activity against Pseudomonas aeruginosa biofilm formation. These clusters were designed by conjugating a range of carbohydrate motifs (galactose, glucose, mannose and lactose, as well as galactose with a triethylene glycol spacer) to a btp (2,6-bis(1,2,3-triazol-4-yl)pyridine) scaffold. This scaffold, which possesses a C₂ symmetry, is an excellent ligand for d-metal ions, and thus the formation of the Ru(ii)-centred glycoclusters 7 and 8Gal was achieved from 5 and 6Gal; each possessing four deprotected carbohydrates. Glycocluster 8Gal, which has a flexible spacer between the btp and galactose moieties, showed significant inhibition of P. aeruginosa bacterial biofilm formation. By contrast, glycocluster 7, which lacked the flexible linker, didn't show significant antimicrobial effects and neither does the ligand 6Gal alone. These results are proposed to arise from carbohydrate–lectin interactions with LecA, which are possible for the flexible metal-centred multivalent glycocluster. Metal-centred glycoclusters present a structurally versatile class of antimicrobial agent for P. aeruginosa, of which this is, to the best of our knowledge, the first example.

Ruthenium-centred glycoclusters based on carbohydrate-functionalised bis(triazolyl)pyridine ligands show Pseudomonas aeruginosa biofilm inhibition, with activity that is dependent on ligand structure.

O7: APPARENT PATHOLOGICAL COMPLETE RESPONSE TO NEOADJUVANT THERAPY LEADS TO SELECTION OF TREATMENT RESISTANT CANCER STEM CELLS IN OESOPHAGEAL ADENOCARCINOMA

Introduction

In oesophageal adenocarcinoma with an apparent pathological complete response (pCR) to neoadjuvant therapy (NAT) there remains debate as to whether oesophagectomy is required. Single Cell RNA sequencing (scRNAseq) enables identification and characterisation of cell populations at higher resolution than diagnostic techniques.

Method

ScRNAseq was used to determine transcriptomic profiles of cell populations in 24 OAC tumours and 13 matched normal samples. Five were also analysed using bulk RNA sequencing and high-precision mass spectrometry proteomics. Immunohistochemistry (IHC) was used to validate pCR. Paired scRNAseq analysis of pre-and post-treatment specimens from three further patients was used to compare transcriptomic profiles before and after NAT. Cancer cells (CCs) were assigned a cancer stem cell (CSC) score curated from published gene sets.

Result

We analysed a total of 22,738 single cells forming 29 different cell phenotypes. In two samples with apparent pCR, IHC staining, bulk RNA sequencing and proteomics of post-treatment samples failed to identify CCs. ScRNAseq, conversely, revealed persistent CCs (12/978 and 45/774). Transcriptomic analysis identified upregulation of stem cell markers and high CSC scores in these cells.

Conclusion

We have shown that CCs persist beneath the lower detection limit of standard approaches in apparent pCR. These cells express marker genes and expression programs consistent with CSCs. CSCs are a critical subpopulation that drive tumour initiation, growth, invasion, metastasis and resistance to therapy. These gene expression programs are not enriched in non-responders and straight to surgery samples. Oesophagus sparing treatment algorithms in pCR may subject patients to unnecessary risk of progression.

Take-home message

Cancer cells remain within tumours after apparent complete pathological response. These cells express stem cell markers associated with resistance to therapy and cancer progression.

Anion-cation synergistic metal-free catalytic oxidative homocoupling of benzylamines by triazolium iodide salts

Triazolium iodide salts are excellent catalysts for the selective oxidative coupling of benzylamines to yield imines. This metal-free reaction proceeds in quantitative spectroscopic yields when run in refluxing 1,2-dichlorobenzene and open to the air. No catalytic activity was observed with related triazolium tetrafluoroborate salts. Variation of catalyst and reaction atmosphere provides mechanistic insights, and revealed dioxygen as the terminal oxidant and the iodine/iodide couple as key redox component in the catalytic dehydrogenation pathway. While molecular iodine is competent as a catalyst in its own right, the triazolium cation triples the reaction rate and reaches turnover frequencies up to 30 h-1, presumably through beneficial interactions of the electron-poor azolium π system and I2, which facilitate the electron transfer from the substrate to iodine and concomitant formation of I-. This acceleration is specific for triazolium cations and represents a hybrid anion/cation catalytic process as a simple and straightforward route towards imine products, with economic advantages over previously reported metal-based catalytic systems.

Carbohydrate-functionalized N-heterocyclic carbene Ru(ii) complexes: synthesis, characterization and catalytic transfer hydrogenation activity

Triazolylidene NHCs decorated with a carbohydrate wingtip group were complexed to a ruthenium(ii) center. Deprotection of the carbohydrate in the metal complex affords a carbohydrate–NHC hybrid system for use as a transfer hydrogenation catalyst.

A folded [2 × 2] metallo-supramolecular grid from a bis-tridentate (1,2,3-triazol-4-yl)-picolinamide (tzpa) ligand

A flexible ditopic ligand 1 containing two N,N,O-tridentate (1,2,3-triazol-4-yl)-picolinamide chelating pockets is reported and the formation of multimetallic architectures is explored in the solid and the solution phase. The self-assembled Zn^II complex [Zn₄(1)₄](ClO₄)₈ exhibited a folded [2 × 2] square grid supramolecular architecture that selectively assembled in MeCN solution as shown using various spectroscopic techniques. The closely related Fe^II complex shows equivalent behaviour in the solid state, while a discrete dinuclear species [Cu₂(NO₃)₄1]·5MeCN was the sole product observed in the solid state from the reaction between 1 and Cu^II under similar conditions.

Population-based cohort study of variation in the use of emergency cholecystectomy for benign gallbladder diseases

Background

The aims of this prospective population-based cohort study were to identify the patient and hospital characteristics associated with emergency cholecystectomy, and the influences of these in determining variations between hospitals.

Methods

Data were collected for consecutive patients undergoing cholecystectomy in acute UK and Irish hospitals between 1 March and 1 May 2014. Potential explanatory variables influencing the performance of emergency cholecystectomy were analysed by means of multilevel, multivariable logistic regression modelling using a two-level hierarchical structure with patients (level 1) nested within hospitals (level 2).

Results

Data were collected on 4744 cholecystectomies from 165 hospitals. Increasing age, lower ASA fitness grade, biliary colic, the need for further imaging (magnetic retrograde cholangiopancreatography), endoscopic interventions (endoscopic retrograde cholangiopancreatography) and admission to a non-biliary centre significantly reduced the likelihood of an emergency cholecystectomy being performed. The multilevel model was used to calculate the probability of receiving an emergency cholecystectomy for a woman aged 40 years or over with an ASA grade of I or II and a BMI of at least 25·0 kg/m2, who presented with acute cholecystitis with an ultrasound scan showing a thick-walled gallbladder and a normal common bile duct. The mean predicted probability of receiving an emergency cholecystectomy was 0·52 (95 per cent c.i. 0·45 to 0·57). The predicted probabilities ranged from 0·02 to 0·95 across the 165 hospitals, demonstrating significant variation between hospitals.

Conclusion

Patients with similar characteristics presenting to different hospitals with acute gallbladder pathology do not receive comparable care.

The btp [2,6-bis(1,2,3-triazol-4-yl)pyridine] binding motif: a new versatile terdentate ligand for supramolecular and coordination chemistry

Ligands containing the btp [2,6-bis(1,2,3-triazol-4-yl)pyridine] motif have appeared with increasing regularity over the last decade. This class of ligands, formed in a one pot ‘click’ reaction, has been studied for various purposes, such as for generating d and f metal coordination complexes and supramolecular self-assemblies, and in the formation of dendritic and polymeric networks, etc. This review article introduces btp as a novel and highly versatile terdentate building block with huge potential in inorganic supramolecular chemistry. We will focus on the coordination chemistry of btp ligands with a wide range of metals, and how it compares with other classical pyridyl and polypyridyl based ligands, and then present a selection of applications including use in catalysis, enzyme inhibition, photochemistry, molecular logic and materials, e.g. polymers, dendrimers and gels. The photovoltaic potential of triazolium derivatives of btp and its interactions with anions will also be discussed.

Self-assembly formation of a healable lanthanide luminescent supramolecular metallogel from 2,6-bis(1,2,3-triazol-4-yl)pyridine (btp) ligands

The self-assembly and rheological studies of self-healing Eu(iii) luminescent metallogels from a btp (2,6-bis(1,2,3-triazol-4-yl)pyridine) ligand is described.

Outcome reporting in bariatric surgery: an in-depth analysis to inform the development of a core outcome set, the BARIACT Study

Outcome reporting in bariatric surgery needs a core outcome set (COS), an agreed minimum set of outcomes reported in all studies of a particular condition. The aim of this study was to summarize outcome reporting in bariatric surgery to inform the development of a COS. Outcomes reported in randomized controlled trials (RCTs) and large non-randomized studies identified by a systematic review were listed verbatim and categorized into domains, scrutinizing the frequency of outcome reporting and uniformity of definitions. Ninety studies (39 RCTs) identified 1,088 separate outcomes, grouped into nine domains with most (n = 920, 85%) reported only once. The largest outcome domain was 'surgical complications', and overall, 42% of outcomes corresponded to a theme of 'adverse events'. Only a quarter of outcomes were defined, and where provided definitions, which were often contradictory. Percentage of excess weight loss was the main study outcome in 49 studies, but nearly 40% of weight loss outcomes were heterogeneous, thus not comparable. Outcomes of diverse bariatric operations focus largely on adverse events. Reporting is inconsistent and ill-defined, limiting interpretation and comparison of published studies. Thus, we propose and are developing a COS for the surgical treatment of severe and complex obesity.

Lanthanide luminescent logic gate mimics in soft matter: [H+] and [F−] dual-input device in a polymer gel with potential for selective component release

Non-covalent incorporation of responsive luminescent lanthanide into a polymer gel produces three-output logic circuit with significant naked-eye colour changes.

A prospective comparison of totally minimally invasive versus open Ivor Lewis esophagectomy

The majority of esophagectomies in Western parts of the world are performed by a transthoracic approach reflecting the prevalence of adenocarcinoma of the lower esophagus or esophagogastric junction. Minimally invasive esophagectomy (MIE) has been reported in a variety of formats, but there are no series that directly compare totally minimally invasive thoracolaparoscopic 2 stage esophagectomy (MIE-2) with open Ivor Lewis (IVL). A prospective single-center cohort study of patients undergoing elective MIE-2 or IVL between January 2005 and November 2010 was performed. Short-term clinicopathologic outcomes were recorded using validated systems. One hundred and six patients (median age 66, range 36-85, 88 M : 18 F) underwent two-stage esophagectomy (53 MIE-2 and 53 IVL). Patient demographics (age, sex, body mass index, American Society of Anesthesiologists grade, tumor characteristics, neoadjuvant chemotherapy, and TNM stage) were comparable between the two groups. Outcomes for MIE-2 and IVL were comparable for anastomotic leak rates (5 [9%] vs. 2 [4%], P= 0.241), resection margin clearance (R0) (43 [81%] vs. 38 [72%], P= 0.253), median lymph node yield (19 vs. 18, P= 0.584), and median length of stay (12 [range 7-91] vs. 12 [range 7-101] days), respectively. Blood loss was significantly less for MIE-2 compared with IVL (median 300 [range 0-1250] mL vs. 400 [range 0-3000] mL, respectively, P= 0.021). MIE-2 in this series of selected patients supports its efficacy, when performed by an experienced minimally invasive surgical team. A well-designed multicenter trial addressing clinical effectiveness is now required.

Impact of integrated PET/CT in the staging of oesophageal cancer: a UK population-based cohort study

AIM

To document the impact of integrated positron-emission tomography and computed tomography (PET/CT) on the management of a cohort of UK patients undergoing PET/CT as part of their staging investigations for potentially curable oesophageal cancer.

MATERIALS AND METHODS

A multicentre, prospective study of newly diagnosed patients with oesophageal cancer undergoing PET/CT was set up across five cancer networks covering a total population of 6.6 million. Data were prospectively collected for cases diagnosed between 1 November 2006 and 31 October 2007.

RESULTS

One hundred and ninety-one patients underwent PET/CT, with 31 (16%) positive for possible metastatic disease. Amongst the 31 positive examinations, 18 (9.4%) were confirmed to have metastatic disease, and 13 (6.5%) patients had no subsequent evidence of metastatic disease, although in three (1.6%) of these a second previously unsuspected pathology was diagnosed. Two patients had false-negative PET/CT and were found to have metastatic disease. The results of the PET/CT examination down-staged 10 (5%) patients thought to have coeliac/M1a node involvement on CT. Fifteen of 110 (13%) patients with stage 3 or 4 disease at CT and endoscopic ultrasound (EUS) had confirmed metastatic disease at PET/CT, compared with none of 18 with stage 2b, three of 52 (6%) with stage 2a, and none of 10 with stage 1 disease.

CONCLUSION

This study confirms the role of PET/CT in a multicentre UK setting in the management of patients with potentially curable carcinoma of the oesophagus, improving the accuracy of pre-treatment staging compared with CT and EUS alone. Early tumours infrequently show evidence of metastasis on PET/CT, although further data are required to confidently determine the stage of tumours where PET/CT has no additional value.

A Two-Consultant Approach is a Safe and Efficient Strategy to Adopt during the Learning Curve for Laparoscopic Roux-en-Y Gastric Bypass: Our Results in the First 100 Procedures

BACKGROUND

Laparoscopic Roux-en-Y gastric bypass (LRYGBP) can be technically challenging. It is imperative that patient morbidity and mortality are minimized while teams are on the learning curve for this procedure.

METHODS

This retrospective study evaluated the peri-operative risk of LRYGBP utilizing a two-consultant surgeon approach in a newly established bariatric service. 100 consecutive patients undergoing LRYGBP were included. Two consultants participated in each procedure.

RESULTS

Median operative duration was 113 minutes (range 80-240) and fell with increasing experience [127 minutes (range 90-240) in cases 1-50 and 105 minutes (range 80-210) in cases 51-100; P=0.009]. Multivariate analysis found operation time correlated only with number of procedures performed (P<0.001). There were no conversions to laparotomy. Intra-operatively, 2 patients had hand-assisted completion of the jejuno-jejunostomy, and 2 underwent laparoscopic revision of the reconstruction. Postoperative complications were observed in 8 patients on the operative admission. Median stay was 4 days (range 3-7). 4 patients required readmission. There was no mortality. Percentage of excess BMI loss was 47%, 53% and 70% at 3, 6 and 12 months respectively.

CONCLUSION

A learning curve for LRYGBP is evidenced in this series by reduction in operative time with increasing experience. Complication rates in line with large published series can be achieved by adopting a two-surgeon approach, which we propose as a safe method to adopt in the development of new bariatric services.

Symptomatic and functional outcome after laparoscopic reoperation for failed antireflux surgery

BACKGROUND

The aim was to determine symptomatic and functional outcome after reoperative antireflux surgery for recurrent reflux, persistent dysphagia and severe gas bloat, using a primarily laparoscopic surgical approach.

METHODS

This was a retrospective analysis of prospectively collected data from 118 patients, of whom 70 had reoperative surgery for recurrent reflux, 35 for dysphagia and 13 for gas bloat. DeMeester scores before and 1 year after surgery, functional symptoms after surgery and overall patient satisfaction were analysed.

RESULTS

Reoperation was completed laparoscopically in 101 patients (85.6 per cent), in 28 after previous open hiatal surgery. The operation was converted from an initial laparoscopic approach to open surgery in 17 patients. One-year follow-up data were available for 104 patients (88.1 per cent). After reoperation for recurrent reflux, 84 per cent had a DeMeester heartburn score of zero or one, and 87 per cent had a regurgitation score of zero or one. After reoperation for dysphagia, 21 of 32 patients had a dysphagia score of zero or one, with improvement observed in 25. All patients undergoing reoperation for severe gas bloat were satisfied with the outcome 1 year after operation.

CONCLUSION

Revisional surgery for recurrent reflux using a laparoscopic approach offered high rates of success and patient satisfaction. Swallowing returned to normal in two-thirds of patients after reoperation.

Site distribution of oesophagogastric cancer

AIMS

It has been suggested that adenocarcinomas of the lower oesophagus and gastric cardia should be reclassified as oesophagogastric junction (OGJ) cancers. This study aimed to define the frequency of OGJ cancers in a geographically defined population of 4.3 million people.

METHODS

All cases of oesophageal and gastric cancer occurring in 1993 were identified by the North Western Regional Cancer Registry. A total of 1192 hospital case notes were reviewed and a study group of 1067 patients was defined. Tumour involvement was documented at individual subsites in the oesophagus and stomach, allowing for tumour presence in more than one oesophageal/gastric subsite.

RESULTS

There were 627 tumours in men and 440 in women. The tumour was confined to the oesophagus in 281 (26.3%) cases and to the stomach in 454 (42.6%) cases. The tumour encroached upon or crossed the OGJ in 332 (31.1%) cases. Overall, tumours involved the cardia, OGJ, or lower oesophagus in 633 (59.3%) cases; in 179 (18.5%) cases the tumour involved the lower oesophagus but not the OGJ, and in another 122 (11.4%) cases the cardia was involved but not the OGJ.

CONCLUSIONS

Oesophagogastric cancers in this population predominantly involve the OGJ, lower oesophagus, and/or cardia.

Prevention of the neoplastic progression of Barrett's oesophagus by endoscopic argon beam plasma ablation

BACKGROUND

Patients with Barrett's oesophagus have a risk of approximately 1 per 100 patient-years for the development of oesophageal adenocarcinoma. Endoscopic ablation of Barrett's oesophagus has been shown to lead to the regrowth of a 'neo' squamous epithelium if gastro-oesophageal reflux is controlled, but the incidence of subsequent tumour formation is unknown.

METHODS

The follow-up of 55 patients who underwent endoscopic ablation of Barrett's oesophagus by argon beam plasma coagulation (ABPC) is reported. Of the 55 patients, nine had low-grade dysplasia, nine had high-grade dysplasia and the remainder had non-dysplastic Barrett's metaplasia. Twelve patients had reflux control by antireflux surgery and the remainder received proton pump inhibitor therapy. Barrett's metaplasia was ablated by ABPC to within 2 cm of the gastro-oesophageal junction.

RESULTS

To date, one patient has died and one patient was unable to complete treatment. The remaining patients were followed by regular endoscopic surveillance for a mean of 38.5 months to give a total follow-up of 173.5 patient-years. No malignancy has developed in any patient during follow-up.

CONCLUSION

The absence of malignant complications in this study of prophylactic ablation of long-segment Barrett's oesophagus strengthens the argument for endoscopic ablation in the prevention of oesophageal adenocarcinoma.

Telementoring as an adjunct to training and competence-based assessment in laparoscopic cholecystectomy

BACKGROUND

We set out to assess telementoring as a training adjunct and an objective means of assessing competence in laparoscopic cholecystectomy (LC).

METHODS

Consecutive patients underwent LC performed by a higher surgical trainee (HST). The laparoscopic image was relayed to an adjoining theater, where the trainer observed as he operated during a parallel operating list. Interaction occurred between trainer and trainee as appropriate; and interaction, procedure difficulty, and duration were recorded.

RESULTS

LC was accomplished in 33 of 34 patients, with one (2.9%) open conversion and one (2.9%) postoperative bile collection. In 21 cases (69%), there was no interaction; in 11 cases (32.4%), there was verbal interaction; and in two cases (5.9%), the trainer scrubbed. Interaction rates for difficulty grades 1, 2, and 3 were 15% (2/13), 41.2% (7/17), and 50% (2/4), with median operating times of 35, 45, and 92 min, respectively.

CONCLUSIONS

Telementoring in LC is feasible, appears to be safe, and may generate objective assessment of a trainee's performance and progress. Evaluation of this technique in a cohort of trainees at different stages is now required.

Argon beam plasma coagulation in the management of cancers of the esophagus and stomach

BACKGROUND

Esophagogastric cancer often presents at an advanced stage, or in patients unfit for resection. These patients may benefit from local ablation to provide both symptom and disease control.

METHODS

A series of 48 consecutive patients with esophagogastric cancer were treated with endoscopic argon beam plasma coagulation (ABPC) at a specialist unit.

RESULTS

Of 16 unfit patients who presented with early cancers, four are disease-free and all are asymptomatic at a median of 21 months after treatment. In 13 of 14 patients with occluded esophageal stents, the esophageal lumen was restored. In 18 patients with advanced cancers, ABPC was employed to debulk two gastric outlet and eight esophageal tumors. Argon was employed successfully to control bleeding in three of five patients. In advanced disease, dysphagia was relieved in only one of three patients.

CONCLUSIONS

Endoscopic ABPC controls symptoms and may control early esophageal and gastric cancers in unfit patients. ABPC allows restoration of the lumen in stent overgrowth and control of bleeding from advanced gastric neoplasms; however, its role in debulking large tumors is less clear.

A randomised controlled trial comparing birthing centre care with delivery suite care in Adelaide, Australia

Birthing centre care offers women with a low risk of complication in pregnancy an alternative to conventional care for the birthing of their baby. It is important these two forms of care are appropriately assessed. A randomised controlled trial comparing the newly opened birthing centre with the established conventional delivery suite was conducted at the then Queen Victoria Hospital, Adelaide, South Australia. The outcomes measured included maternal satisfaction, costs and clinical outcomes both for mother and baby which related to the need for Caesarean section, episiotomy or tear rate and method of feeding. Two hundred and one women attending the hospital's antenatal clinic were randomly allocated to either birthing centre or delivery suite care. One hundred women were allocated to the birthing centre. No differences were found in either group related to clinical outcomes or costs. The only difference in maternal satisfaction was the choice women made for their next birth. More women in the birthing centre group felt they were encouraged to breastfeed immediately after birth. While the numbers in this study were too small to detect any but large differences in outcome, birthing centre care should remain an option for women and further studies undertaken with larger numbers.

The South Australian Nurse Practitioner Project: a midwife's perspective on a new initiative

Midwifery education in Australia is currently the focus of intense debate both within and outside the field of midwifery. Proposed changes arsing from these debates centre principally around the issue of midwifery as a separate profession from nursing. This paper describes a case in point as to how changes in attitude and practice are occurring. As a midwife representing the Australian College of Midwives Inc.- SA Branch (ACMI-SA) on the Advisory Committee of the South Australian Nurse Practitioner Project, I provide an insight into some of the debates around midwifery and its relationship with this project. ACMI was a member of the Ministerial Advisory Committee established following the initiative of the Executive of the Department of Human Services (DHS) (formerly the South Australian Health Commission) in forming the Nurse Practitioner Project. The Terms of Reference for this committee included the development of an operational framework for the development and implementation of the Nurse Practitioner role in South Australia. A collaborative approach was seen as essential to enable nurses to best serve their communities by functioning at an advanced level of practice. The ACMI and midwives generally fully support the Nurse Practitioner Project for nurses. By Jennifer Pauline Byrne.

Telementoring in laparoscopic cholecystectomy: a useful adjunct in training and assessment of higher surgical trainees

AIMS: This study assessed the feasibility, safety and utility of telementoring as a training tool in laparoscopic cholecystectomy (LC) for higher surgical trainees (HST). Telementoring in LC was developed as a technique for objective assessment of performance and progress in order to help decide when an HST is competent to perform LC unsupervised. METHODS: This was a prospective study of patients attending for LC, with surgery performed by an HST, in which the laparoscopic image was relayed live to an adjoining room where a supervising consultant observed the procedure. The trainee or supervisor sought or proffered advice/assistance as appropriate, and safety, complication rates, operating time, difficulty of procedure, intervention rate and type were recorded. RESULTS: LC was accomplished in 33 of 34 patients enrolled; there was one conversion to an open procedure. Interaction between the HST and trainer occurred in 11 cases, by way of advice being sought or offered, and in two of these the supervisor scrubbed up and took over the operation. The rate of interaction and duration of the procedure increased with procedure difficulty, with rates of interaction for difficulty grades 1, 2 and 3 of 15 per cent (two of 13), 41 per cent (seven of 17) and 50 per cent (two of four), and overall median operating times of 35 (23-50), 45 (28-75) and 92 (45-110) min respectively. CONCLUSIONS: Telementoring for trainees capable of performing LC is feasible and appears to be safe with a supervising surgeon situated in the immediate vicinity. Telementoring in LC is a promising tool that may provide objective assessment of a trainee's insight, skill and progress in operative performance.

Urine is a saturated equilibrium and not a metastable supersaturated solution: evidence from crystalluria and the general composition of calcium salt and uric acid calculi

A computer algorithm is described which allows urine to be modelled as a saturated equilibrium solution with respect to any combination of the solids calcium oxalate, calcium hydrogen phosphate (brushite), amorphous calcium phosphate, uric acid, sodium hydrogen urate and ammonium hydrogen urate. It is demonstrated that this model of urine, unlike the widely accepted metastable supersaturated solution model, explains the long-known calcium salt crystalluria versus pH curves of both non-stone-forming and stone-forming urine. Further, the saturation model accounts for why most "infection" stones do not contain calcium oxalate and why most "urate" stones are composed solely of uric acid and not admixed with alkali metal hydrogen urate salts. The supersaturation model of urine cannot explain satisfactorily these well-known phenomena. For example, the supersaturation model predicts that virtually all "infection" stones should contain calcium oxalate along with calcium phosphate and, perhaps, struvite.

Duodenogastric reflux of bile in health: the normal range

Duodenogastric reflux (DGR) is suspected to be an aetiological factor in the pathogenesis of foregut disease. The 'Bilitec' bile probe allows continuous detection of bilirubin, based on spectrophotochemical properties. We aimed to describe duodenogastric bile reflux in healthy, normal volunteers in a Western European population, as a basis for the future study of DGR in disease. An international multicentre study was established. DGR was measured using 24 h ambulatory bile and pH monitoring in the proximal stomach, in 43 normal volunteers from the third to the seventh decades. Subjects adhered to a standard protocol. The total test period, supine and upright components, were analysed. The 90th percentile values for absorbance thresholds of 0.14, 0.25, 0.3, 0.4 and 0.5 were 40.5%, 20.9%, 19.6%, 11.6% and 4.6% of the total time respectively. There was a wide range of absorbance within each threshold. Supine DGR was greater than upright, and associated with an alkaline tide. The upright phase was further subdivided into upright fasting, prandial and post prandial phases, and ranges for these periods are also described. No relationship between age, weight, or body mass index and duodenogastric reflux was seen. The results of this study form a range which allows further investigation into the contribution of duodenogastric bile reflux in the pathogenesis of foregut disease.

Comparative study of intestinal metaplasia and mucin staining at the cardia and esophagogastric junction in 225 symptomatic patients presenting for diagnostic open-access gastroscopy

OBJECTIVE

Adenocarcinoma around the esophagogastric junction (EGJ) is increasing in incidence, and is frequently associated with areas of macroscopic or microscopic intestinal metaplasia (IM). The aim of this study was to define the incidence and type of metaplastic changes in the cardia and at the EGJ in symptomatic patients in whom there was no endoscopic columnar segment.

METHODS

Patients attending for open-access gastroscopy had three sets of endoscopic biopsies taken at 3-cm intervals, from cardia, EGJ, and distal esophagus. Hematoxylin and eosin, Alcian blue/PAS (AB/PAS), and high-iron diamine/Alcian blue (AB/HID) were used to define and characterize IM.

RESULTS

Of 225 patients, eight (4%) had carcinoma, eight (4%) had conventional long-segment Barrett's esophagus, 15 (7%) showed endoscopic short-segment Barrett's change, with no endoscopic Barrett's in 194 (86.2%). Of the latter, 34 (17.5%) had IM at the EGJ, and nine (4.6%) had IM at the cardia on hematoxylin and eosin. Acid mucin stains were positive at the EGJ in 135 (69.6%) and at the cardia in 75 (38.7%). Metaplasia at the EGJ was associated with sulphomucins (p < 0.0001) and involved the surface glandular epithelium (p < 0.0001) more frequently than the cardia. Metaplasia was not related to reflux symptoms, hiatus hernia, or endoscopic esophageal inflammation. Ninety percent of those with IM detectable by hematoxylin and eosin were taking acid suppression, compared with 72.8% overall.

CONCLUSIONS

Intestinal metaplasia is very common at the esophagogastric junction and gastric cardia, with marked differences in incidence and characteristics of mucin staining between the two sites. The relationship of intestinal metaplasia to the development of carcinoma is yet to be determined.

Restoration of the normal squamous lining in Barrett's esophagus by argon beam plasma coagulation

OBJECTIVE

Barrett's esophagus is associated with significantly increased risk of development of esophageal adenocarcinoma. Replacing columnar epithelium with the normal squamous lining in this condition offers the possibility of decreasing the risk of degeneration to invasive adenocarcinoma. This study aimed to establish the feasibility of argon beam plasma coagulation (ABPC), in conjunction with control of gastroesophageal reflux, to restore the squamous lining.

METHODS

Thirty patients with Barrett's esophagus (four low-grade dysplasia, three high-grade) were recruited from our surveillance program, and underwent endoscopic ABPC.

RESULTS

Twenty-seven patients completed treatment, with macroscopic replacement of their columnar lining by squamous epithelium, histologically confirmed in all 27, and followed up for a median of 9 months (range, 6-18 months). Two patterns of squamous replacement were identified: 70% of patients showed squamous epithelium with no persistent intestinal metaplasia, and in 30% the new squamous epithelium covered areas of underlying intestinal metaplasia. One patient has withdrawn from the study. Two esophageal perforations, with one death, occurred early in the study.

CONCLUSION

ABPC, in conjunction with control of gastroesophageal reflux, allows squamous regrowth in both benign and dysplastic Barrett's esophagus. Despite the theoretical safety advantages of ABPC over techniques such as laser, esophageal perforation may occur with this technique. It is too soon to recommend ABPC for dysplastic or nondysplastic Barrett's because follow-up is too short to show a decreased incidence of and mortality from adenocarcinoma.

The aortic homograft: evolution of indications, techniques, and results in 107 patients

BACKGROUND

Homograft aortic valve replacement has been performed in 107 patients during the past 7 years. Two primary methods of implantation were used (intraaortic and root replacement). Results of both methods are presented.

METHODS

Intraaortic implantation (subcoronary or cylinder technique) was performed in 36 patients (mean age, 54 years) for aortic stenosis or regurgitation (31 patients) and endocarditis (5 patients). Aortic root replacement was performed in 71 patients (mean age, 62 years). The majority (58 patients) had complex root pathologies such as ascending aneurysm, dissection, or prosthetic endocarditis with annular destruction. Early results were assessed with intraoperative or predischarge echocardiography; annual echocardiograms provided long-term follow-up. Left ventricular mass was calculated in patients with long-standing pathology for whom preoperative and postoperative data were available.

RESULTS

Early valvular insufficiency was documented in 16 of the 36 intraaortic implants (44%); 9 of these have had progression of the insufficiency. Of the 20 patients who had trivial or no early insufficiency, significant insufficiency has developed in 7 and mild insufficiency has developed in 5. Calculation of left ventricular mass revealed a mean reduction of 11% at 1 year. There has been no mortality, endocarditis, or homograft-related reoperation in the intraaortic group with a mean follow-up of 50 months. The root replacement group had a hospital mortality of 17%. The cardiac pathology was limited to the aortic valve in 12 patients; mortality in this subset was zero. There has been no significant early or late postoperative valvular insufficiency in the 59 surviving patients. More rapid left ventricular mass reduction was seen in this group with a 26% mean reduction within 1 year. A mean follow-up of 32 months in the root replacement group has seen no homograft-related reoperations.

CONCLUSIONS

Although the lack of early mortality in the intraaortic group makes this technique appealing, the high incidence of early insufficiency with the realistic expectation of progression has led to our abandonment of the intraaortic technique. Homograft aortic root replacement confers a higher mortality based on the severity of aortic pathology, but offers excellent long-term hemodynamics in any patient. We have expanded our indication for homograft root replacement to include patients with isolated valvular disease rather than reserving it for those patients with extensive root pathology.

Neutrophilic dermatoses: pyoderma gangrenosum and Sweet's syndrome

Pyoderma gangrenosum and Sweet's syndrome are classified as neutrophilic dermatoses as they exhibit intense dermal inflammatory infiltrates composed of neutrophils with little evidence of a primary vasculitis. They share several characteristics and respond to immunosuppressives. Aetiology is felt to represent a manifestation of altered immunologic reactivity. Patients with both conditions concurrently have been described. Diagnosis is based on clinical and histopathological findings. However, clinically the typical forms of the two conditions are quite distinct: pyoderma showing cutaneous ulceration with a purple undermined border and Sweet's syndrome having tender, erythematous, nonulcerated plaques and nodules. Approximately 50% of cases of pyoderma are associated with a specific systemic disorder. These include inflammatory bowel disease, rheumatoid arthritis, non-Hodgkin's lymphoma and myeloproliferative disorders. Many associations with Sweet's syndrome have been described, including acute myeloid leukaemia, myeloma and adenocarcinomas, and haematological malignancy. There is overlap between the two conditions with lesions categorised as Sweet's syndrome being clinically more characteristic of atypical pyoderma and vice versa. We believe that pyoderma and Sweet's syndrome represent a continuum of spectrum of disease. The reason for the clinical differences between the conditions is unclear and merits further investigation but may be explained by varying levels of intensity and extent of the inflammatory process. This review will describe the pathogenesis, clinical features, diagnosis, associations and treatment of the two conditions.

Red tattoo reactions: X-ray microanalysis and patch-test studies

Eighteen patients who developed cutaneous reactions to red tattoos were studied to identify the chemicals responsible for the reactions to modern red tattoo pigments. Biopsies from the tattoos were examined histologically and the chemical composition of the red pigments was analysed by X-ray microanalysis. A variety of metallic elements including aluminium, iron, calcium, titanium, silicon, mercury and cadmium were detected. Patch tests were performed to the relevant chemicals in nine cases, and only one patient reacted to mercury. This study demonstrates that although reactions to mercury still occur, other red dyes containing a variety of inorganic pigments may provoke a cutaneous inflammatory response.

Necrolytic migratory erythema: association with neuroendocrine tumour with predominant insulin secretion

We report a case of necrolytic migratory erythema in association with a neuroendocrine tumour producing predominantly insulin. As far as we know this has not been observed before.

Lymphomatoid granulomatosis mimicking bronchial carcinoma

This report concerns a patient with lymphomatoid granulomatosis who presented with multiple ulcerated skin nodules, a solitary pulmonary mass and a cerebral mass. Biopsies taken from the skin and lung lesion showed necrotic tissue only. This combination of physical signs and the initial non-specific histological changes suggested a diagnosis of primary bronchial carcinoma with secondary spread. However, the subsequent temporary improvement and a further histological examination enabled a diagnosis of lymphomatoid granulomatosis to be made and this was confirmed at post-mortem. This report emphasizes the difficulty in obtaining diagnostic material in lymphomatoid granulomatosis and highlights the need to consider this diagnosis in a patient with suspected carcinoma when biopsy material shows necrotic tissue only.