Biomarker endpoints in cancer cachexia clinical trials: Systematic Review 5 of the cachexia endpoint series

Regulatory agencies require evidence that endpoints correlate with clinical benefit before they can be used to approve drugs. Biomarkers are often considered surrogate endpoints. In cancer cachexia trials, the measurement of biomarkers features frequently. The aim of this systematic review was to assess the frequency and diversity of biomarker endpoints in cancer cachexia trials. A comprehensive electronic literature search of MEDLINE, Embase and Cochrane (1990-2023) was completed. Eligible trials met the following criteria: adults (≥18 years), prospective design, more than 40 participants, use of a cachexia intervention for more than 14 days and use of a biomarker(s) as an endpoint. Biomarkers were defined as any objective measure that was assayed from a body fluid, including scoring systems based on these assays. Routine haematology and biochemistry to monitor intervention toxicity were not considered. Data extraction was performed using Covidence, and reporting followed PRISMA guidance (PROSPERO: CRD42022276710). A total of 5975 studies were assessed, of which 52 trials (total participants = 6522) included biomarkers as endpoints. Most studies (n = 29, 55.7%) included a variety of cancer types. Pharmacological interventions (n = 27, 51.9%) were most evaluated, followed by nutritional interventions (n = 20, 38.4%). Ninety-nine different biomarkers were used across the trials, and of these, 96 were assayed from blood. Albumin (n = 29, 55.8%) was assessed most often, followed by C-reactive protein (n = 22, 42.3%), interleukin-6 (n = 16, 30.8%) and tumour necrosis factor-α (n = 14, 26.9%), the latter being the only biomarker that was used to guide sample size calculations. Biomarkers were explicitly listed as a primary outcome in six trials. In total, 12 biomarkers (12.1% of 99) were used in six trials or more. Insulin-like growth factor binding protein 3 (IGFBP-3) and insulin-like growth factor 1 (IGF-1) levels both increased significantly in all three trials in which they were both used. This corresponded with a primary outcome, lean body mass, and was related to the pharmacological mechanism. Biomarkers were predominately used as exploratory rather than primary endpoints. The most commonly used biomarker, albumin, was limited by its lack of responsiveness to nutritional intervention. For a biomarker to be responsive to change, it must be related to the mechanism of action of the intervention and/or the underlying cachexia process that is modified by the intervention, as seen with IGFBP-3, IGF-1 and anamorelin. To reach regulatory approval as an endpoint, the relationship between the biomarker and clinical benefit must be clarified.

Body weight and composition endpoints in cancer cachexia clinical trials: Systematic Review 4 of the cachexia endpoints series

Significant variation exists in the outcomes used in cancer cachexia trials, including measures of body composition, which are often selected as primary or secondary endpoints. To date, there has been no review of the most commonly selected measures or their potential sensitivity to detect changes resulting from the interventions being examined. The aim of this systematic review is to assess the frequency and diversity of body composition measures that have been used in cancer cachexia trials. MEDLINE, Embase and Cochrane Library databases were systematically searched between January 1990 and June 2021. Eligible trials examined adults (≥18 years) who had received an intervention aiming to treat or attenuate the effects of cancer cachexia for >14 days. Trials were also of a prospective controlled design and included body weight or at least one anthropometric, bioelectrical or radiological endpoint pertaining to body composition, irrespective of the modality of intervention (e.g., pharmacological, nutritional, physical exercise and behavioural) or comparator. Trials with a sample size of <40 patients were excluded. Data extraction used Covidence software, and reporting followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidance. This review was prospectively registered (PROSPERO: CRD42022276710). A total of 84 clinical trials, comprising 13 016 patients, were eligible for inclusion. Non-small-cell lung cancer and pancreatic cancer were studied most frequently. The majority of trial interventions were pharmacological (52%) or nutritional (34%) in nature. The most frequently reported endpoints were assessments of body weight (68 trials, n = 11 561) followed by bioimpedance analysis (BIA)-based estimates (23 trials, n = 3140). Sixteen trials (n = 3052) included dual-energy X-ray absorptiometry (DEXA)-based endpoints, and computed tomography (CT) body composition was included in eight trials (n = 841). Discrepancies were evident when comparing the efficacy of interventions using BIA-based estimates of lean tissue mass against radiological assessment modalities. Body weight, BIA and DEXA-based endpoints have been most frequently used in cancer cachexia trials. Although the optimal endpoints cannot be determined from this review, body weight, alongside measurements from radiological body composition analysis, would seem appropriate. The choice of radiological modality is likely to be dependent on the trial setting, population and intervention in question. CT and magnetic resonance imaging, which have the ability to accurately discriminate tissue types, are likely to be more sensitive and provide greater detail. Endpoints are of particular importance when aligned with the intervention's mechanism of action and/or intended patient benefit.

Upper gastrointestinal training in the UK and Ireland: a Roux Group Study

INTRODUCTION

Surgical training programmes in the United Kingdom and Ireland (UK&I) are in a state of flux. This study aims to report the contemporary opinions of trainee and consultant surgeons on the current upper gastrointestinal (UGI) training model in the UK&I.

METHODS

A questionnaire was developed and distributed via national UGI societies. Questions pertained to demographics, current training evaluation, perceived requirements and availability.

RESULTS

A total of 241 responses were received with representation from all UK&I postgraduate training regions. The biggest discrepancies between rotation demand and national availability related to advanced/therapeutic endoscopy and robotic surgery, with 91.7% of respondents stating they would welcome greater geographical flexibility in training. The median suggested academic targets were 3-5 publications (trainee vs consultant <3 vs 3-5, p<0.001); <3 presentations (<3 vs 3-5, p=0.002); and 3-5 audits/quality improvement projects (<3 vs 3-5, p<0.001). Current operative requirements were considered achievable (87.6%) but inadequate for day one consultant practice (74.7%). Reassuringly, 76.3% deemed there was role for on-the-job operative training following consultant appointment. Proficiency in diagnostic endoscopy was considered a minimum requirement for Certificate of Completion of Training (CCT) yet the majority regarded therapeutic endoscopy competency as non-essential. The median numbers of index UGI operations suggested were comparable with the current curriculum requirements. Post-CCT fellowships were not considered necessary; however, the majority (73.6%) recognised their advantage.

CONCLUSIONS

Current CCT requirements are largely consistent with the opinions of the UGI community. Areas for improvement include flexibility in geographical working and increasing national provisions for high-quality endoscopy training.

Prognostic Biomarkers of Systemic Inflammation in Non-Small Cell Lung Cancer: A Narrative Review of Challenges and Opportunities

Non-small cell lung cancer (NSCLC) is a common malignancy and is associated with poor survival outcomes. Biomarkers of systemic inflammation derived from blood tests collected as part of routine clinical care offer prognostic information for patients with NSCLC that may assist clinical decision making. They are an attractive tool, as they are inexpensive, easily measured, and reproducible in a variety of healthcare settings. Despite the wealth of evidence available to support them, these inflammatory biomarkers are not yet routinely used in clinical practice. In this narrative review, the key inflammatory indices reported in the literature and their prognostic significance in NSCLC are described. Key challenges limiting their clinical application are highlighted, including the need to define the optimal biomarker of systemic inflammation, a lack of understanding of the systemic inflammatory landscape of NSCLC as a heterogenous disease, and the lack of clinical relevance in reported outcomes. These challenges may be overcome with standardised recording and reporting of inflammatory biomarkers, clinicopathological factors, and survival outcomes. This will require a collaborative approach, to which this field of research lends itself. This work may be aided by the rise of data-driven research, including the potential to utilise modern electronic patient records and advanced data-analysis techniques.

Cachexia index for prognostication in surgical patients with locally advanced oesophageal or gastric cancer: multicentre cohort study

BACKGROUND

Features of cancer cachexia adversely influence patient outcomes, yet few currently inform clinical decision-making. This study assessed the value of the cachexia index (CXI), a novel prognostic marker, in patients for whom neoadjuvant chemotherapy and surgery for oesophagogastric cancer is planned.

METHODS

Consecutive patients newly diagnosed with locally advanced (T3-4 or at least N1) oesophagogastric cancer between 1 January 2010 and 31 December 2015 were identified through the West of Scotland and South-East Scotland Cancer Networks. CXI was calculated as (L3 skeletal muscle index) × (serum albumin)/(neutrophil lymphocyte ratio). Sex-stratified cut-off values were determined based on the area under the curve (AUC), and patients were divided into groups with low or normal CXI. Primary outcomes were disease progression during neoadjuvant chemotherapy and overall survival (at least 5 years of follow-up).

RESULTS

Overall, 385 patients (72% men, median age 66 years) were treated with neoadjuvant chemotherapy for oesophageal (274) or gastric (111) cancer across the study interval. Although patients with a low CXI (men: CXI below 52 (AUC 0.707); women: CXI below 41 (AUC 0.759)) were older with more co-morbidity, disease characteristics were comparable to those in patients with a normal CXI. Rates of disease progression during neoadjuvant chemotherapy, leading to inoperability, were higher in patients with a low CXI (28 versus 12%; adjusted OR 3.07, 95% c.i. 1.67 to 5.64; P < 0.001). Low CXI was associated with worsened postoperative mortality (P = 0.019) and decreased overall survival (median 14.9 versus 56.9 months; adjusted HR 1.85, 1.42 to 2.42; P < 0.001).

CONCLUSION

CXI is associated with disease progression, worse postoperative mortality, and overall survival, and could improve prognostication and decision-making in patients with locally advanced oesophagogastric cancer.

Appetite and dietary intake endpoints in cancer cachexia clinical trials: Systematic Review 2 of the cachexia endpoints series

There is no consensus on the optimal endpoint(s) in cancer cachexia trials. Endpoint variation is an obstacle when comparing interventions and their clinical value. The aim of this systematic review was to summarize and evaluate endpoints used to assess appetite and dietary intake in cancer cachexia clinical trials. A search for studies published from 1 January 1990 until 2 June 2021 was conducted using MEDLINE, Embase and Cochrane Central Register of Controlled Trials. Eligible studies examined cancer cachexia treatment versus a comparator in adults with assessments of appetite and/or dietary intake as study endpoints, a sample size ≥40 and an intervention lasting ≥14 days. Reporting was in line with PRISMA guidance, and a protocol was published in PROSPERO (2022 CRD42022276710). This review is part of a series of systematic reviews examining cachexia endpoints. Of the 5975 articles identified, 116 were eligible for the wider review series and 80 specifically examined endpoints of appetite (65 studies) and/or dietary intake (21 studies). Six trials assessed both appetite and dietary intake. Appetite was the primary outcome in 15 trials and dietary intake in 7 trials. Median sample size was 101 patients (range 40-628). Forty-nine studies included multiple primary tumour sites, while 31 studies involved single primary tumour sites (15 gastrointestinal, 7 lung, 7 head and neck and 2 female reproductive organs). The most frequently reported appetite endpoints were visual analogue scale (VAS) and numerical rating scale (NRS) (40%). The appetite item from the European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire (EORTC QLQ) C30/C15 PAL (38%) and the appetite question from North Central Cancer Treatment Group anorexia questionnaire (17%) were also frequently applied. Of the studies that assessed dietary intake, 13 (62%) used food records (prospective registrations) and 10 (48%) used retrospective methods (24-h recall or dietary history). For VAS/NRS, a mean change of 1.3 corresponded to Hedge's g of 0.5 and can be considered a moderate change. For food records, a mean change of 231 kcal/day or 11 g of protein/day corresponded to a moderate change. Choice of endpoint in cachexia trials will depend on factors pertinent to the trial to be conducted. Nevertheless, from trials assessed and available literature, NRS or EORTC QLQ C30/C15 PAL seems suitable for appetite assessments. Appetite and dietary intake endpoints are rarely used as primary outcomes in cancer cachexia. Dietary intake assessments were used mainly to monitor compliance and are not validated in cachexia populations. Given the importance to cachexia studies, dietary intake endpoints must be validated before they are used as endpoints in clinical trials.

The prognostic impact of pre-treatment cachexia in resectional surgery for oesophagogastric cancer: a meta-analysis and meta-regression

BACKGROUND

Cancer cachexia is not purely an end-stage phenomenon and can influence the outcomes of patients with potentially curable disease. This review examines the effect of pre-treatment cachexia on overall survival, in patients undergoing surgical resection of oesophagogastric cancer.

METHODS

A systematic literature search of MEDLINE, EMBASE and Cochrane Library databases was conducted, from January 2000 to May 2022, to identify studies reporting the influence of cachexia on patients undergoing an oesophagogastric resection for cancer with curative intent. Meta-analyses of the primary (overall survival) and secondary (disease-free survival and postoperative mortality) outcomes were performed using random-effects modelling. Meta-regression was used to examine disease stage as a potential confounder.

RESULTS

Ten non-randomized studies, comprising 7186 patients, were eligible for inclusion. The prevalence of pre-treatment cachexia was 35 per cent (95 per cent c.i.: 24-47 per cent). Pooled adjusted hazard ratios showed that cachexia was adversely associated with overall survival (HR 1.46, 95 per cent c.i.: 1.31-1.60, P < 0.001). Meta-analysis of proportions identified decreased overall survival at 1-, 3- and 5-years in cachectic cohorts. Pre-treatment cachexia was not a predictor of disease-free survival and further data are required to establish its influence on postoperative mortality. The proportion of patients with stage III/IV disease was a significant moderator of between-study heterogeneity. Cachexia may have a greater influence on overall survival in studies where more patients have a locally advanced malignancy.

CONCLUSION

Pre-treatment cachexia adversely influences overall survival following resection of an oesophagogastric malignancy.

Biocompatibility of Antifogging SiO-doped Diamond-Like Carbon Laparoscope Coatings

Laparoscopes can suffer from fogging and contamination difficulties, resulting in a reduced field of view during surgery. A series of diamond-like carbon films, doped with SiO, were produced by pulsed laser deposition for evaluation as biocompatible, antifogging coatings. DLC films doped with SiO demonstrated hydrophilic properties with water contact angles under 40°. Samples subjected to plasma cleaning had improved contact angle results, with values under 5°. Doping the DLC films with SiO led to an average 40% decrease in modulus and 60% decrease in hardness. Hardness of the doped films, 12.0 - 13.2 GPa, was greater than that of the uncoated fused silica substrate, 9.2 GPa. The biocompatibility was assessed through CellTiter-Glo assays, with the films demonstrating statistically similar levels of cell viability when compared to the control media. The absence of ATP released by blood platelets in contact with the DLC coatings suggests in vivo hemocompatibility. The SiO doped films displayed improved transparency levels in comparison to undoped films, achieving up to an average of 80% transmission over the visible spectrum and an attenuation coefficient of 1.1 × 10⁴ cm^-1 at the 450 nm wavelength. The SiO doped DLC films show promise as a method of fog prevention for laparoscopes.

Demographics, diagnostics, treatment, and outcomes of patients presenting with acute groin hernia: 15-year multicentre retrospective cohort study

BACKGROUND

Groin hernias commonly present acutely in high-risk populations and can be challenging to manage. This retrospective, observational study aimed to report on patient demographics and outcomes, following acute admissions with a groin hernia, in relation to contemporary investigative and management practices.

METHODS

Adult (≥18 years old) patients who presented acutely with a groin hernia to nine National Health Service trusts in the north of England between 2002 and 2016 were included. Data were collected regarding patient demographics, radiological investigations, and operative intervention. The primary outcome of interest was 30-day inpatient mortality rate.

RESULTS

Overall, 6165 patients with acute groin hernia were included (4698 inguinal and 1467 femoral hernias). There was a male preponderance (72.5 per cent) with median age of 73 years (interquartile range (i.q.r.) 58-82). The burden of patient co-morbidity increased over the study period (P < 0.001). Operative repair was performed in 2258 (55.1 per cent) of patients with an inguinal and 1321 (90.1 per cent) of patients with a femoral hernia. Bowel resection was more commonly required for femoral hernias (14.7 per cent) than inguinal hernias (3.5 per cent, P < 0.001) and in obstructed (14.6 versus 0.2 per cent, P < 0.001) or strangulated (58.4 versus 4.5 per cent, P < 0.001) hernias. The 30-day mortality rate was 3.1 per cent for the overall cohort and 3.9 per cent for those who underwent surgery. Bowel resection was associated with increased duration of hospital stay (P < 0.001) and 30-day inpatient mortality rate (P < 0.001). Following adjustment for confounding variables, advanced age, co-morbidity, obstruction, and strangulation were all associated with an increased 30-day mortality rate (all P < 0.001).

CONCLUSION

Emergency hernia repair has high mortality rates. Advanced age and co-morbidity increase both duration of hospital stay and 30-day mortality rate.

Longitudinal characterisation of cachexia in patients undergoing surgical resection for cancer

PURPOSE OF REVIEW

The complexity of the cancer cachexia phenotype has undoubtedly hindered researchers' understanding of this devastating syndrome. The presence and magnitude of host-tumour interactions are rarely considered during clinical decision-making within the current staging paradigm. Furthermore, treatment options for those patients who are identified as suffering from cancer cachexia remain extremely limited.

RECENT FINDINGS

Previous attempts to characterise cachexia have largely focussed on individual surrogate disease markers, often studied across a limited timeframe. While the adverse prognostic value of clinical and biochemical features is evident, the relationships between these are less clear. Investigation of patients with earlier-stage disease could allow researchers to identify markers of cachexia that precede the refractory stage of the wasting process. Appreciation of the cachectic phenotype within 'curative' populations may aid our understanding of the syndrome's genesis and provide potential routes for prevention, rather than treatment.

SUMMARY

Holistic, longitudinal characterisation of cancer cachexia, across all at-risk and affected populations, is of vital importance for future research in the field. This paper presents the protocol for an observational study aiming to create a robust and holistic characterisation of surgical patients with, or at risk of, cancer cachexia.

Evaluation of remote digital postoperative wound monitoring in routine surgical practice

Remote digital postoperative wound monitoring provides an opportunity to strengthen postoperative community care and minimise the burden of surgical-site infection (SSI). This study aimed to pilot a remote digital postoperative wound monitoring service and evaluate the readiness for implementation in routine clinical practice. This was a single-arm pilot implementational study of remote digital postoperative wound monitoring across two tertiary care hospitals in the UK (IDEAL stage 2b, clinicaltrials.gov: NCT05069103). Adults undergoing abdominal surgery were recruited and received a smartphone-delivered wound assessment tool for 30-days postoperatively. Patients received 30-day postoperative follow-up, including the Telehealth Usability Questionnaire (TUQ). A thematic mixed-methods approach was used, according to the WHO framework for monitoring and evaluating digital health interventions. 200 patients were enroled, of whom 115 (57.5%) underwent emergency surgical procedures. Overall, the 30-day SSI rate was 16.5% (n = 33/200), with 72.7% (n = 24) diagnosed post-discharge. Usage of the intervention was 83.0% (n = 166/200), with subsequently 74.1% (n = 123/166) TUQ completion. There were no issues reported with feasibility of the technology, with the reliability (3.87, 95% CI: 3.73-4.00) and quality of the interface rated highly (4.18, 95%: 4.06-4.30). Patient acceptance was similarly high with regards to ease of use (4.51, 95% CI: 4.41-4.62), satisfaction (4.27, 95% CI: 4.13-4.41), and usefulness (4.07, 95% CI: 3.92-4.23). Despite the desire for more frequent and personalised interactions, the majority viewed the intervention as providing meaningful benefit over routine postoperative care. Remote digital postoperative wound monitoring successfully demonstrated readiness for implementation with regards to the technology, usability, and healthcare process improvement.

The Impact of Acute Systemic Inflammation Secondary to Oesophagectomy and Anastomotic Leak on Computed Tomography Body Composition Analyses

This study aimed to longitudinally assess CT body composition analyses in patients who experienced anastomotic leak post-oesophagectomy. Consecutive patients, between 1 January 2012 and 1 January 2022 were identified from a prospectively maintained database. Changes in computed tomography (CT) body composition at the third lumbar vertebral level (remote from the site of complication) were assessed across four time points where available: staging, pre-operative/post-neoadjuvant treatment, post-leak, and late follow-up. A total of 20 patients (median 65 years, 90% male) were included, with a total of 66 computed tomography (CT) scans analysed. Of these, 16 underwent neoadjuvant chemo(radio)therapy prior to oesophagectomy. Skeletal muscle index (SMI) was significantly reduced following neoadjuvant treatment (p < 0.001). Following the inflammatory response associated with surgery and anastomotic leak, a decrease in SMI (mean difference: -4.23 cm²/m², p < 0.001) was noted. Estimates of intramuscular and subcutaneous adipose tissue quantity conversely increased (both p < 0.001). Skeletal muscle density fell (mean difference: -5.42 HU, p = 0.049) while visceral and subcutaneous fat density were higher following anastomotic leak. Thus, all tissues trended towards the radiodensity of water. Although tissue radiodensity and subcutaneous fat area normalised on late follow-up scans, skeletal muscle index remained below pre-treatment levels.

The impact of age on long-term survival following gastrectomy for gastric cancer

INTRODUCTION

Gastrectomy remains the primary curative treatment modality for patients with gastric cancer. Concerns exist about offering surgery with a high associated morbidity and mortality to elderly patients. The study aimed to evaluate the long-term survival of patients with gastric cancer who underwent gastrectomy comparing patients aged <70 years with patients aged ≥70 years.

METHODS

Consecutive patients who underwent gastrectomy for adenocarcinoma with curative intent between January 2000 and December 2017 at a single centre were included. Patients were stratified by age with a cut-off of 70 years used to create two cohorts. Log rank test was used to compare overall survival and Cox multivariable regression used to identify predictors of long-term survival.

RESULTS

During the study period, 959 patients underwent gastrectomy, 520 of whom (54%) were aged ≥70 years. Those aged <70 years had significantly lower American Society of Anesthesiologists grades (p<0.001) and were more likely to receive neoadjuvant chemotherapy (39% vs 21%; p<0.001). Overall complication rate (p=0.001) and 30-day postoperative mortality (p=0.007) were lower in those aged <70 years. Long-term survival (median 54 vs 73 months; p<0.001) was also favourable in the younger cohort. Following adjustment for confounding variables, age ≥70 years remained a predictor of poorer long-term survival following gastrectomy (hazard ratio 1.35, 95% confidence interval 1.09, 1.67; p=0.006).

CONCLUSIONS

Low postoperative mortality and good long-term survival were demonstrated for both age groups following gastrectomy. Age ≥70 years was, however, associated with poorer outcomes. This should be regarded as important factor when counselling patients regarding treatment options.

Evaluating temporal trends and the impact of surgical subspecialisation on patient outcomes following adhesional small bowel obstruction: a multicentre cohort study

PURPOSE

Small bowel obstruction (SBO) is the most common indication for laparotomy in the UK. While general surgeons have become increasingly subspecialised in their elective practice, emergency admissions commonly remain undifferentiated. This study aimed to assess temporal trends in the management of adhesional SBO and explore the influence of subspecialisation on patient outcomes.

METHODS

Data was collected for patients admitted acutely with adhesional SBO across acute NHS trusts in Northern England between 01/01/02 and 31/12/16, including demographics, co-morbidities and procedures performed. Patients were excluded if a potentially non-adhesional cause was identified and were grouped by the responsible consultant's subspecialty. The primary outcome of interest was 30-day inpatient mortality.

RESULTS

Overall, 2818 patients were admitted with adhesional SBO during a 15-year period. There was a consistent female preponderance, but age and comorbidity increased significantly over time (both p < 0.001). In recent years, more patients were managed operatively with a trend away from delayed surgery also evident (2002-2006: 65.7% vs. 2012-2016: 42.7%, p < 0.001). Delayed surgery was associated with an increased mortality risk on multivariable regression analysis (OR: 2.46 (1.46-4.23, p = 0.001)). CT scanning was not associated with management strategy or timing of surgery (p = 0.369). There was an increased propensity for patients to be managed by gastrointestinal (colorectal and upper gastrointestinal) subspecialists over time. Length of stay (p < 0.001) and 30-day mortality (p < 0.001) both improved in recent years, with the best outcomes seen in colorectal (2.6%) and vascular subspecialists (2.4%). However, following adjustment for confounding variables, consultant subspecialty was not a predictor of mortality.

CONCLUSION

Outcomes for patients presenting with adhesional SBO have improved despite the increasing burden of age and co-morbidity. While gastrointestinal subspecialists are increasingly responsible for their care, mortality is not influenced by consultant subspecialty.

Temporal Trends in the Investigation, Management and Outcomes of Acute Appendicitis over 15 Years in the North of England: A Retrospective Cohort Study

BACKGROUND

Acute appendicitis is a common surgical emergency with an estimated lifetime prevalence of 8.6% for males and 6.7% for females. Despite the frequency of presentation, considerable variation in clinical practice exists. Our study aimed to explore temporal trends in the investigation, treatment and outcomes for patients with appendicitis between 2002 and 2016.

METHODS

Data collected included all patients aged ≥16 years across the NHS trusts in Northern England between 01/01/2002 and 31/12/2016 diagnosed with appendicitis. Patient demographics, co-morbidity and management strategies were included. Outcomes of interest were length of stay and inpatient mortality.

RESULTS

Over a 15 years period, 22,137 patients were admitted with acute appendicitis. A consistent male preponderance (n = 11,952, 54%) was observed, and median age increased over time (2002-2006: 36.4 vs. 2012-2016: 39.5, p < 0.001). Comorbidity of patients also increased (p < 0.001) in recent years. Computed tomography (CT) use increased from 0.8 to 21.9% (p < 0.001) over the study period. Following CT scanning, there was a longer time to theatre (1.22 vs. 0.70 days, p < 0.001), and patients were more frequently managed non-operatively (23.8% vs. 5.7%, p < 0.001). The utilisation of laparoscopic approaches significantly increased from 4.1 to 70.4% (p < 0.001). Laparoscopic patients had a shorter median length of stay (2.97 days) when compared with open surgery (4.44 days) or non-operative (6.19 days) patients. The 30-day mortality rate was 0.33% overall and decreased with time (p = 0.004).

CONCLUSIONS

CT and laparoscopic surgery are increasingly utilised in the management of appendicitis. Along with other advances in clinical practice, they have led to reduced lengths of stay and mortality.

Understanding Cancer Cachexia and Its Implications in Upper Gastrointestinal Cancers

OPINION STATEMENT

Considerable advances in the investigation and management of oesophagogastric cancer have occurred over the last few decades. While the historically dismal prognosis associated with these diseases has improved, outcomes remain very poor. Cancer cachexia is an often neglected, yet critical, factor for this patient group. There is a persuasive argument that a lack of assessment and treatment of cachexia has limited progress in oesophagogastric cancer care. In the curative setting, the stage of the host (based on factors such as body composition, function, and inflammatory status), alongside tumour stage, has the potential to influence treatment efficacy. Phenotypical features of cachexia may decrease the survival benefit of (peri-operative) chemoradiotherapy, immunotherapy, or surgical resection in patients with potentially curative malignancy. Most patients with oesophagogastric cancer unfortunately present with disease which is not amenable, or is unlikely to respond, to these treatments. In the palliative setting, host factors can similarly impair results from systemic anti-cancer therapies, cause adverse symptoms, and reduce quality of life. To optimise treatment pathways and enhance patient outcomes, we must utilise this information during clinical decision-making. As our understanding of the genesis of cancer cachexia improves and more therapeutic options, ranging from basic (e.g. exercise and nutrition) to targeted (e.g. anti-IL1 α and anti-GDF-15), become available, there can be grounds for optimism. Cachexia can change from a hitherto neglected condition to an integral part of the oesophagogastric cancer treatment pathway.

The junior doctor changeover effect: does it exist in general surgery?

INTRODUCTION

Junior doctor changeover has been perceived as a period of increased risk to patients. However, there is a paucity of contemporary evidence of this 'changeover effect'. The aim of this study was to evaluate the presence of an adverse patient effect during periods of junior doctor changeover.

METHODS

Data were requested on all patients aged 18 years or older admitted acutely under General Surgery in the North of England between 2005 and 2016. This included patient characteristics, diagnoses, comorbidities, procedure codes, mortality and length of stay. Patients were included in the study if they were admitted during the 'changeover week'; defined as the first day of the changeover followed by the six subsequent days. For junior trainees (FY1-CT2), this is the first Wednesday of August, December and April each year. For higher surgical trainees (ST3-ST8), it is the first Wednesday in October. Another week, four weeks prior, was chosen as a historical comparator.

RESULTS

In total, 61,714 patients were included in this study. Patient characteristics did not vary between the cohorts. There was no difference in 30-day mortality between changeover and non-changeover groups (2.5% vs 2.6%, p = 0.280) or length of stay (5.3 vs 5.2, p = 0.613). Changeover week was not a predictor of increased mortality (OR 1.06, p = 0.302) following multivariable adjustment. Further analysis of the first junior and higher specialty trainee periods, August and October, respectively, showed no significant difference for measured outcomes.

CONCLUSIONS

This retrospective cohort study provides contemporary evidence that the 'changeover effect' does not exist in acute general surgical admissions in the UK.

Patient Outcomes Following Emergency Bowel Resection for Inflammatory Bowel Disease and the Impact of Surgical Subspecialisation in the North of England: A Retrospective Cohort Study

BACKGROUND

Management of inflammatory bowel disease (IBD) has changed considerably over recent years, which has coincided with increased subspecialisation amongst general surgeons. This study evaluated the demographics and outcomes of patients with IBD undergoing bowel resection and assessed for the potential impact of surgical subspecialisation.

METHODS

Patient demographic, operative and outcome data were collected for patients undergoing a bowel resection secondary to IBD, admitted acutely to NHS trusts in the North of England between 2002 and 2016. The primary outcome of interest was 30-day post-operative mortality, with secondary outcomes: length of stay, stoma and anastomosis rates.

RESULTS

A total of 913 patients were included in the study cohort. A reduction in the number of resections was noted over time (2002-2006: 361 vs. 2012-2016: 262). No change was observed for 30-day mortality over the study period (3.9%, p = 0.233). Length of stay was also unchanged (p = 0.949). Laparoscopic surgery was increasingly utilised (0.6% vs. 17.2%, p < 0.001) in recent years, and by colorectal subspecialists (p = 0.003). More patients were managed by a colorectal consultant latterly (2002-2006: 45.4% vs. 2012-2016: 63.7%, p < 0.001). There was no difference between colorectal and other subspecialists in mortality (p = 0.156), length of stay (p = 0.201), stoma (p = 0.629) or anastomosis (p = 0.659) rates, including following multivariable adjustment.

CONCLUSION

The study demonstrated a significant reduction in the number of resections over time, increased utilisation of a laparoscopic approach and a shift towards the care of IBD surgical patients being by a colorectal subspecialist. However, these changes do not correspond with improved surgical outcomes.

The impact of surgical subspecialization on patient outcomes following emergency colorectal resections in the north of England: a retrospective cohort study

AIM

Emergency colorectal surgery is associated with significant morbidity and mortality. Most general surgeons have a subspecialty, which forms the focus of their elective work, allowing development of specialist skill sets. The aim of this study was to assess the impact of consultant subspecialization on patient outcomes following emergency colorectal resections.

METHODS

Data were requested for all emergency admissions under a general surgeon between 1 January 2002 and 31 December 2016 within the north of England. These were acquired from individual Trusts following Caldicott approval. Data included demographics, diagnoses and any procedures undertaken. Patients were assigned to cohorts based on the subspecialist interest of the consultant they were under the care of. The primary outcome of interest was 30-day postoperative mortality. Categorical data were compared with the chi-squared test, and continuous data with the t test or ANOVA. A logistic regression model determined factors associated with 30-day in-hospital mortality.

RESULTS

Overall, 7648 emergency colorectal resections were performed with a 30-day postoperative mortality of 13.8%. This was significantly lower if the responsible consultant was a colorectal surgeon compared with other general surgery subspecialties (11.8% vs. 15.2%, P < 0.001). This was significant on univariate analysis (OR 0.75, P < 0.001); however, following multivariable adjustment, this was not statistically significant (P = 0.380). The colorectal specialists had a higher laparoscopy rate than their colleagues-9.8% versus 6.8% (P < 0.001). Stoma rates were also lower (46.9% vs. 51.0%, P = 0.001) and anastomosis rates higher (55.9% vs. 49.3%, P < 0.001) amongst colorectal surgeons.

CONCLUSION

These findings add to the growing body of evidence that patient outcomes may be improved by involving subspecialists in colorectal emergencies.

Decision analysis of minimally invasive management options for cholecysto-choledocholithiasis

BACKGROUND

The management of cholecysto-choledocholithiasis is controversial with the risks and benefits of one versus two-stage approaches debated. This study aims to perform decision analysis of minimally invasive laparo-endoscopic approaches.

METHODS

An advanced decision tree was constructed to compare pre, intra and post-operative ERCP and laparoscopic common bile duct exploration in terms of primary ductal clearance and significant complications for patients intended to undergo laparoscopic cholecystectomy. Transition probabilities were calculated from randomised controlled trials following a comprehensive literature search. Model uncertainties were extensively tested through deterministic and probabilistic Monte Carlo sensitivity analysis. Utility outcomes were 1 and 0.5 for successful primary clearance without and with complications, respectively, and 0 for failure of primary clearance of the duct.

RESULTS

Twenty-one studies (n = 2697) were included in the analysis. At base case analysis, a laparo-endoscopic rendezvous approach had the highest utility output (0.90; no complication probability: 0.87/complication probability 0.06). Laparoscopic common bile duct exploration was ranked second with a utility output 0.87 (no complication probability: 0.82/complication probability 0.10). Pre-operative ERCP utility score was 0.84 (no complication probability: 0.78/ complication probability 0.11) and post-operative ERCP utility score was 0.78 (no complication probability: 0.71/complication probability 0.13). Monte Carlo analysis showed that laparo-endoscopic rendezvous and laparoscopic common bile duct exploration had an equal mean utility output of 0.57 (standard deviation 0.36; variance 0.13; 95% confidence interval 0.00-0.99 versus standard deviation 0.34; variance 0.12; 95% confidence interval 0.01-0.98). Laparo-endoscopic rendezvous had a superior treatment selection frequency of 39.93% followed by laparoscopic bile duct exploration (36.11%), pre-operative ERCP (20.67%) and post-operative ERCP (2.99%).

CONCLUSION

One-stage approach to the management of cholecysto-choledocholithiasis is superior to two-stage, in terms of primary clearance of the duct and risk of operative morbidity. Laparo-endoscopic rendezvous approach could offer marginal additional benefit but more high-quality randomised controlled trials are needed.

The prospects of sitting 'end of year' open book exams in the light of COVID-19: A medical student's perspective

Medical schools in the UK have been forced to dramatically restructure teaching and assessment amidst the Coronavirus (COVID-19) pandemic. As part of this, some have opted to assess progression through open book examinations (OBE). I aim to share my thoughts as an unsettled 4th year medical student about to embark on my first set of clinical exams conducted in this format. The difficulties associated with preparing for examinations under such unique and challenging circumstances cannot be underestimated. Working from home, during social distancing, surrounds students with the extra family stresses that we are all facing during this pandemic. This combined with a new, unfamiliar examination format will inevitably lead to students feeling daunted. While some would argue that an OBE may reward good problem solvers, students still require a strong foundation of knowledge. The luxury of reference will not be afforded in all clinical settings thus leading to concerns regarding students skimming over essential learning points. Furthermore, we cannot ignore the increased opportunity for academic misconduct resulting from an open book assessment format. Why are medical schools placing undue stress on students who could instead focus their attention on living compassionately for others during this difficult time?

Perioperative intravenous contrast administration and the incidence of acute kidney injury after major gastrointestinal surgery: prospective, multicentre cohort study

BACKGROUND

This study aimed to determine the impact of preoperative exposure to intravenous contrast for CT and the risk of developing postoperative acute kidney injury (AKI) in patients undergoing major gastrointestinal surgery.

METHODS

This prospective, multicentre cohort study included adults undergoing gastrointestinal resection, stoma reversal or liver resection. Both elective and emergency procedures were included. Preoperative exposure to intravenous contrast was defined as exposure to contrast administered for the purposes of CT up to 7 days before surgery. The primary endpoint was the rate of AKI within 7 days. Propensity score-matched models were adjusted for patient, disease and operative variables. In a sensitivity analysis, a propensity score-matched model explored the association between preoperative exposure to contrast and AKI in the first 48 h after surgery.

RESULTS

A total of 5378 patients were included across 173 centres. Overall, 1249 patients (23·2 per cent) received intravenous contrast. The overall rate of AKI within 7 days of surgery was 13·4 per cent (718 of 5378). In the propensity score-matched model, preoperative exposure to contrast was not associated with AKI within 7 days (odds ratio (OR) 0·95, 95 per cent c.i. 0·73 to 1·21; P = 0·669). The sensitivity analysis showed no association between preoperative contrast administration and AKI within 48 h after operation (OR 1·09, 0·84 to 1·41; P = 0·498).

CONCLUSION

There was no association between preoperative intravenous contrast administered for CT up to 7 days before surgery and postoperative AKI. Risk of contrast-induced nephropathy should not be used as a reason to avoid contrast-enhanced CT.

Evaluating outcomes following emergency laparotomy in the North of England and the impact of the National Emergency Laparotomy Audit - A retrospective cohort study

BACKGROUND

Emergency laparotomy is associated with high morbidity and mortality. Current trends suggest improvements have been made in recent years, with increased survival and shorter lengths of stay in hospital. The National Emergency Laparotomy Audit (NELA) has evaluated participating hospitals in England and Wales and their individual outcomes since 2013. This study aims to establish temporal trends for patients undergoing emergency laparotomy and evaluate the influence of NELA.

METHODS

Data for emergency laparotomies admitted to NHS hospitals in the Northern Deanery between 2001 and 2016 were collected, including demographics, co-morbidities, diagnoses, operations undertaken and outcomes. The primary outcome of interest was in-hospital death within 30 days of admission. Cox-regression analysis was undertaken with adjustment for covariates.

RESULTS

There were 2828 in-hospital deaths from 24,291 laparotomies within 30 days of admission (11.6%). Overall 30-day mortality significantly reduced during the 15-year period studied from 16.3% (2001-04), to 8.1% during 2013-16 (p < 0.001). After multivariate adjustment, laparotomies undertaken in more recent years were associated with a lower mortality risk compared to earlier years (2013-16: HR 0.73, p < 0.001). There was a significant improvement in 30-day postoperative mortality year-on-year during the NELA period (from 9.1 to 7.1%, p = 0.039). However, there was no difference in postoperative mortality for patients who underwent laparotomy during NELA (2013-16) compared with the preceding three years (both 8.1%, p = 0.526).

DISCUSSION

30 day postoperative mortality for emergency laparotomy has improved over the past 15-years, with significantly reduced mortality risk in recent years. However, it is unclear if NELA has yet had a measurable effect on 30-day post-operative mortality.

Perforated diverticulitis in the North of England: trends in patient outcomes, management approach and the influence of subspecialisation

INTRODUCTION

In recent years, several management options have been used in the management of perforated diverticulitis, ranging from conservative treatment to laparotomy. General surgery has also become increasingly specialised over time. This retrospective cohort study investigated changes in patient outcomes following perforated diverticulitis, management approach and the influence of consultant subspecialisation over time.

MATERIALS AND METHODS

Data was collected on patients admitted with perforated diverticulitis in the North of England between 2002 and 2016. Subspecialisation was categorised as colorectal or other general subspecialties. The primary outcome of interest was overall 30-day mortality; secondary outcomes included surgical approach, stoma and anastomosis rate.

RESULTS

A total of 3394 cases of perforated diverticulitis were analysed (colorectal, n = 1290 and other subspecialists, n = 2104) with a 30-day mortality of 11.6%. There was a significant reduction in mortality over time (2002-2006: 18.6% to 2012-2016: 6.8, P < 0.001).There was a significant reduction in open surgery (60% to 25.3%, P < 0.001) with increased conservative management (37.4% to 63.5%, P < 0.001), laparoscopic resection (0.1% to 4.9%, P < 0.001) and laparoscopic washout (0.1% to 5.7%, P < 0.001).Patients admitted under colorectal surgeons had lower mortality than other subspecialists (9.9% vs 12.4%, P = 0.027), which remained significant following multivariate adjustment (hazard ratio 1.44, P = 0.039). These patients had fewer stomas (13.9% vs. 21.0%, P = 0.001) and higher anastomosis rates (22.1% vs 15.8%, P = 0.004).

CONCLUSION

This study demonstrated considerable improvements in the management of perforated diverticulitis alongside the positive impact of subspecialisation on patient outcomes.

Evaluating the effects of surgical subspecialisation on patient outcomes following emergency laparotomy: A retrospective cohort study

BACKGROUND

General surgeons have become increasingly subspecialised in their elective practice. Emergency laparotomies, however, are performed by a range of subspecialists who may or may not have an interest in the affected area of gastrointestinal tract. This retrospective cohort study evaluates the impact of surgical subspecialisation on patient outcomes following emergency laparotomy.

METHODS

Data was collected for patients who underwent an emergency abdominal procedure on the gastrointestinal tract in the North of England from 2001 to 2016. This included demographics, co-morbidities, diagnoses and procedures undertaken. Patients were grouped according to consultants' subspecialist interest. The primary outcome of interest was 30-day postoperative mortality.

RESULTS

24,291 emergency laparotomies were performed with an associated 30-day postoperative mortality of 11.7%. Laparotomies undertaken by upper gastrointestinal (UGI) or colorectal surgeons have significantly lower mortality (10.1%) when compared with other subspecialities (13.5%). More specifically, mortality was decreased for UGI (7.9% vs. 12.9%) and colorectal procedures (10.9% vs. 14.2%) when performed by surgeons with a specialist interest in the relevant area of the gastrointestinal tract (both p < 0.001). The utilisation of laparoscopic surgery is higher, in both UGI (21.8% vs. 9.0%) and colorectal procedures (7.2% vs. 3.5%), when the causative pathology is relevant to the surgeon's subspeciality (both p < 0.001).

CONCLUSION

Mortality following emergency laparotomy is improved when performed under the care of gastrointestinal surgeons. Both UGI and colorectal emergency procedures have improved outcomes, with lower mortality and higher rates of laparoscopy, when under the care of a surgeon with a subspecialist interest in the affected area of the gastrointestinal tract.

The survivorship of the link endo-rotational hinge total knee arthroplasty: 5-12-year follow-up of 100 patients

INTRODUCTION

There is a paucity of survival data reporting the medium to long-term outcome of the LINK® Endo-Model^® rotational hinge total knee arthroplasty (ERH-TKA). Such information is essential when counselling patients and predictors of survival would help inform patients of their likely outcome.

MATERIALS AND METHODS

A series of patients, who received an ERH-TKA, with a minimum follow-up of 5 years, were retrospectively identified from an established arthroplasty database. Data were collected from paper and electronic patient records. This included patient demographics, indication for surgery, complication rates and revision status. Our primary outcome of interest was joint implant survival.

RESULTS

One hundred patients underwent an ERH-TKA over an 11-year period. There were 66 females and 34 males, with a mean age of 73.8 years and 67.6 years, respectively. Indications were classified into primary (n = 41), aseptic revision (n = 47) and two-stage infective revision (n = 12). The median follow-up was 8.2 (range 5-12) years. One-year implant survival amongst the cohort was 99%, falling to 95% at 5 years. Overall, there were eight revisions during the follow-up period. Considering only cases of aseptic failure, survival was 97% at 5 years and all failures occurred amongst revision cases. Implant failure was greater following revision arthroplasty but this was not statistically significant (p = 0.97). Cox regression analysis identified male sex to be the only independent predictor of failure (hazard ratio 1.75, 95% CI 1.04-31.82, p = 0.04) after adjusting for confounding variables.

CONCLUSIONS

The ERH-TKA has a good medium- to long-term survival rate but male patients are nearly twice as likely to undergo revision, compared to females, and should be made aware of this preoperatively.

Soil color indicates carbon and wetlands: developing a color-proxy for soil organic carbon and wetland boundaries on sandy coastal plains in South Africa

A relationship between soil organic carbon and soil color is acknowledged-albeit not a direct one. Since heightened carbon contents can be an indicator of wetlands, a quantifiable relationship between color and carbon might assist in determining wetland boundaries by rapid, field-based appraisal. The overarching aim of this initial study was to determine the potential of top soil color to indicate soil organic carbon, and by extension wetland boundaries, on a sandy coastal plain in South Africa. Data were collected from four wetland types in northern KwaZulu-Natal in South Africa. Soil samples were taken to a depth of 300 mm in three transects in each wetland type and analyzed for soil organic carbon. The matrix color was described using a Munsell soil color chart. Various color indices were correlated with soil organic carbon. The relationship between color and carbon were further elucidated using segmented quantile regression. This showed that potentially maximal carbon contents will occur at values of low color indices, and predictably minimal carbon contents will occur at values of low or high color indices. Threshold values can thus be used to make deductions such as "when the sum of dry and wet Value and Chroma values is 9 or more, carbon content will be 4.79% and less." These threshold values can then be used to differentiate between wetland and non-wetland sites with a 70 to 100% certainty. This study successfully developed a quantifiable correlation between color and carbon and showed that wetland boundaries can be determined based thereon.

Toxicity of four sulfonamide antibiotics to the freshwater amphipod Hyalella azteca

Sulfonamides are a widely used class of antibiotics; however, there are few toxicological data available with which to conduct environmental risk assessments for these compounds. Therefore, the toxicity of four sulfonamides (sulfaguanidine, sulfathiazole, sulfamerazine, and sulfasalazine) to Hyalella azteca was assessed in chronic (four-week), water-only exposures. Survival was evaluated weekly, and growth was measured at the end of the test. Four-week lethal concentrations associated with 50% mortality (LC50s) for sulfaguanidine, sulfathiazole, and sulfamerazine were 0.90, 1.6, and 3.9 µM, respectively. Sulfaguanidine caused effects on survival more quickly and at lower concentrations than sulfathiazole or sulfamerazine. These differences were more pronounced at week 1 than week 4, when sulfaguanidine LC50s were 8 to 20 times lower and 2 to 4 times lower, respectively. Growth was affected by sulfathiazole but was a less sensitive end point than survival, with an effective concentration associated with 50% reduction in growth (EC50) of 13 µM, whereas sulfaguanidine and sulfamerazine caused negligible effects on growth. Sulfasalazine had no effect on survival or growth at any concentration tested, up to 13 µM. The effects observed in the present study occurred at concentrations exceeding those typically found in environmental waters. However, given that LC50s decreased with exposure duration (except for sulfasalazine), the present study demonstrates the importance of conducting longer-term tests to adequately assess the environmental toxicity of sulfonamides.

Causes of toxicity to Hyalella azteca in a stormwater management facility receiving highway runoff and snowmelt. Part I: polycyclic aromatic hydrocarbons and metals

The Terraview-Willowfield Stormwater Management Facility (TWSMF) receives inputs of multiple contaminants, including metals, polycyclic aromatic hydrocarbons (PAHs), road salt, and nutrients, via highway and residential runoff. Contaminant concentrations in runoff are seasonally dependent, and are typically high in early spring, coinciding with the snowmelt. In order to investigate the seasonal fluctuations of contaminant loading and related changes in toxicity to benthic invertebrates, overlying water and sediment samples were collected in the fall and spring, reflecting low and high contaminant loading, respectively, and four-week sediment toxicity tests were conducted with Hyalella azteca. The effects of metals and PAHs are discussed here; the effects of salts, nutrients, and water quality are discussed in a companion paper. Survival and growth of Hyalella after exposure to fall samples were variable: survival was significantly reduced (64-74% of controls) at three out of four sites, but there were no significant growth effects. More dramatic effects were observed after Hyalella were exposed to spring samples: survival was significantly reduced at the two sites furthest downstream (0-75% of controls), and growth was significantly lower in four out of five sites when comparing Hyalella exposed to site sediment with overlying site water versus site sediment with overlying control water. These seasonal changes in toxicity were not related to metals or PAHs: 1. levels of bioavailable metals were below those expected to cause toxicity, and 2. levels of PAHs in sediment were lowest at sites with the greatest toxicity and highest in water and sediment at sites with no toxicity. Although not associated with toxicity, some metals and PAHs exceeded probable and severe effect levels, and could be a cause for concern if contaminant bioavailability changes. Toxicity in the TWSMF appeared to be primarily associated with water-borne contaminants. The cause(s) of these effects are discussed in our companion manuscript.

Causes of toxicity to Hyalella azteca in a stormwater management facility receiving highway runoff and snowmelt. Part II: salts, nutrients, and water quality

The Terraview-Willowfield Stormwater Management Facility (TWSMF) features a tandem of stormwater management ponds, which receive inputs of multiple contaminants from highway and residential runoff. Previous research determined that benthic communities in the ponds were impacted by poor habitat quality, due to elevated sediment concentrations of metals and polycyclic aromatic hydrocarbons (PAHS), and salinity in the overlying water, but did not address seasonal changes, including those caused by the influx of contaminants with the snowmelt. In order to address this issue, water and sediment samples were collected from the TWSMF during the fall and spring, and four-week sediment toxicity tests were conducted with Hyalella azteca. The effects of metals and PAHs are discussed in a companion paper; the effects of road salt, nutrients, and water quality are discussed here. After exposure to fall samples, survival of Hyalella was reduced (64-74% of controls) at three out of four sites, but growth was not negatively affected. After exposure to spring samples, survival was 0-75% of controls at the two sites furthest downstream, and growth was significantly lower in four out of five sites when comparing Hyalella exposed to site water overlying site sediment versus control water overlying site sediment. Toxicity appeared to be related to chloride concentrations: little or no toxicity occurred in fall samples (200 mg Cl(-)/L), and significant effects on survival and growth occurred in spring samples above 1550 mg Cl(-)/L and 380 mg Cl(-)/L, respectively. Sodium chloride toxicity tests showed similar results: four-week LC50s and EC25s (growth) were 1200 and 420 mg Cl(-)/L, respectively. Although water quality and nutrients were associated with effects observed in the TWSMF, chloride from road salt was the primary cause of toxicity in this study. Chloride persists during much of the year at concentrations representing a significant threat to benthic communities in the TWSMF.

Maternal influences on thiamine status of walleye Sander vitreus ova

Concentrations of the various forms of thiamine (vitamin B(1) ) were determined in walleye Sander vitreus ova from three central North American lakes. Total thiamine concentrations in ova from Lake Winnipeg S. vitreus were approximately three times greater (mean 12 nmol g(-1) ) than in those from Lakes Erie or Ontario. The percentage of thiamine in the active form (thiamine pyrophosphate, TPP) was highest in Lake Ontario ova (mean 88%) and lowest in those from Lake Winnipeg (mean 70%). Neither ova total thiamine concentration nor per cent ova thiamine as TPP showed any consistent relationships with maternal age, size, morphometric condition, somatic lipid concentrations or liver lipid concentrations. Ova total thiamine concentration, however, was negatively related to ovum size in some populations, as well as among populations, and was positively related to liver total thiamine concentration. Maternal transfer of thiamine to ova appears to be independent of female ontogenetic or conditional state in S. vitreus.

Vaccination--knowledge and attitudes of school children

Low vaccine up-take in Ireland resulted in the measles epidemic of 2000-2001, and more recent outbreaks of mumps in many schools and colleges. Forty-five schools were selected from a list of secondary schools in Ireland using a table of random numbers, and teachers were requested to distribute self-administered questionnaires to their 4th year students. The questionnaires were analysed using Epi-Info and chi-square test. 86% (n=675) of students considered themselves inadequately informed about vaccines and vaccine-preventable diseases. 67.9% (n=532) wanted the topic added to the science syllabus. 88.3% (n=692) agreed that they would vaccinate their own children against all childhood diseases. It is recommended that the topic of vaccination be covered more completely by the Junior Certificate Science syllabus. It is concluded that the vaccination up-take rates in the Ireland should rise with the next generation.

Radiographic measurements of cardiac size as predictors of outcome in patients with dilated cardiomyopathy

BACKGROUND

Cardiac dilatation is a predictor of poor outcome in patients with dilated cardiomyopathy. Whereas cardiac chamber dimensions or volumes can be assessed by various noninvasive and invasive techniques, simple chest radiography also may provide a valuable assessment of cardiac size.

METHODS AND RESULTS

To determine the relative power of radiographic heart measurements for predicting outcome in dilated cardiomyopathy, we retrospectively studied 88 adult patients with chest radiographs obtained within 35 days of echocardiography. Standard radiographic variables were measured for each patient, and the cardiothoracic (CT) ratio, frontal cardiac area, and volume were calculated. During a mean 4.1-year follow-up, 62 of the 88 (71%) patients died. CT ratio was the best predictor of mortality among the radiographic cardiac measurements. By multivariate analysis, a model including echocardiographic ejection fraction, New York Heart Association (NYHA) functional class, and history of heart failure was highly predictive of survival. When added to this model, CT ratio also was independently associated with mortality, but not radiographic cardiac area or volume. When radiographic variables were each added to CT ratio, they did not add incremental predictive value to the model that included CT ratio alone. Echocardiographic measurement of left ventricular (LV) size, especially when indexed for body size, was independently predictive of outcome, but it did not supersede the predictive power of CT ratio.

CONCLUSION

The simply derived radiographic CT ratio is a useful predictor of outcome in patients with dilated cardiomyopathy and compares favorably with other clinical and selected echocardiographic variables.

How water scarcity will shape the new century

Water resources are increasingly being overexploited, such that current food production, which relies heavily on irrigation schemes, is unsustainable. Many steps, including improved irrigation techniques, more water-efficient crops and animal protein production, etc., will be needed to raise water productivity across the board. Water must in future be recognised as a scarce resource and not taken for granted.

Line Positions and Intensities in the 2nu(2)/nu(4) Vibrational System of (14)NH(3) near 5-7 µm

Line positions and intensities belonging to the vibrational system 2nu(2)/nu(4) of ammonia (14)NH(3) are measured and analyzed between 1200 and 2200 cm(-1) in order to improve the molecular database. For this, laboratory spectra are obtained at 0.006 and 0.011 cm(-1) unapodized resolution and with 4% precisions for the intensities using Fourier transform spectrometers located at the Kitt Peak National Observatory and the Jet Propulsion Laboratory. The observed data contain transitions of the nu(4) fundamental band near 1626.276(1) and 1627.375(2) cm(-1) (for s and a inversion upper states, respectively) and the 2nu(2) overtone band near 1597.470(3) and 1882.179(5) cm(-1) (for s and a inversion states, respectively). A total of 2345 lines with J' </= 15 is assigned from which 2114 line positions with J' </= 15 are fitted using an effective rotation-inversion-rotation Hamiltonian to achieve an rms of 0.003 cm(-1) with 57 molecular parameters. Over 1200 intensity measurements are modeled to +/-4.7% using 16 terms of the dipole moment expansion. A dyad model is used in order to model all the interactions expected within the 2nu(2)/nu(4) system. The bandstrengths of 2nu(2) (s <-- a), 2nu(2) (a <-- s), and nu(4) (s <-- s and a <-- a) are estimated to be 6.68(24), 0.201(5), and 116(3) cm(-2) atm(-1), respectively, at 296 K. The prediction generated by this study is available for planetary studies. Copyright 2000 Academic Press.

The Intensities of Methane in the 3-5 µm Region Revisited

The analysis of the linestrengths of the infrared spectrum of methane (12 and 13) in the 3-5 µm region has been revisited on the basis of new measurements from Fourier transform spectra recorded at Kitt Peak under various optical densities. A simultaneous fit of these new data with previously reported tunable difference-frequency laser data has been done. An effective transition moment model in tensorial form up to the third order of approximation within the Pentad scheme has been used. The standard deviations achieved are very close to the experimental precision: 3 and 1.5%, respectively, for the two sets of data for the (12)CH(4) molecule, representing a substantial improvement with respect to earlier studies. The integrated bandstrengths obtained in the present work differ from previously reported values by factors ranging from -5 to +6%. The correction for the nu(3) band, the strongest band of the Pentad system, is +2% with respect to the study of Hilico et al. [J. C. Hilico, J. P. Champion, S. Toumi, V. G. Tyuterev, and S. A. Tashkun, J. Mol. Spectrosc. 168, 455-476 (1994)]. Copyright 2000 Academic Press.

The NMR solution structure of the ion channel peptaibol chrysospermin C bound to dodecylphosphocholine micelles

Chrysospermin C is a 19-residue peptaibol capable of forming transmembrane ion channels in phospholipid bilayers. The conformation of chrysospermin C bound to dodecylphosphocholine micelles has been solved using heteronuclear NMR spectroscopy. Selective 15N-labeling and 13C-labeling of specific alpha-aminoisobutyric acid residues was used to obtain complete stereospecific assignments for all eight alpha-aminoisobutyric acid residues. Structures were calculated using 339 distance constraints and 40 angle constraints obtained from NMR data. The NMR structures superimpose with mean global rmsd values to the mean structure of 0. 27 A (backbone heavy atoms) and 0.42 A (all heavy atoms). Chrysospermin C bound to decylphosphocholine micelles displays two well-defined helices at the N-terminus (residues Phe1-Aib9) and C-terminus (Aib13-Trp-ol19). A slight bend preceding Pro14, i.e. encompassing residues 10-12, results in an angle of approximately 38 degrees between the mean axes of the two helical regions. The bend structure observed for chrysospermin C is compatible with the sequences of all 18 long peptaibols and may represent a common 'active' conformation. The structure of chrysospermin C shows clear hydrophobic and hydrophilic surfaces which would be appropriate for the formation of oligomeric ion channels.

Dominant sensitization variants of human O(6)-methylguanine-DNA-methyltransferase obtained by a mutational screen of surface residues

A scanning mutagenesis experiment was performed on human O(6)-methylguanine methyltransferase (hMGMT), directed largely at non-conserved surface residues that have not previously been studied. Variants typically contained two or more substitutions. Two of the 16 variants characterized in detail are inactive for methyltransfer, but increase the cytotoxicity and mutagenic effects of methylating agents. This phenotype is reminiscent of a variant (C145A) that has a mutation in the methyl-accepting cysteine. C145A is inactive, but reportedly binds methylated DNA and confers sensitivity to methylating agents. The sensitization phenotype of the two new variants is more striking in strains that are wild-type for DNA repair than in strains that are deficient for repair, suggesting that these proteins inhibit functional DNA repair proteins by competitively binding to methylated DNA. Both variants have multiple substitutions in the last helix of the protein. These results suggest that the C-terminal helix is necessary for methyltransfer activity, but not for methylguanine-specific binding.

Experimental Line Parameters of the Oxygen A Band at 760 nm

To support atmospheric remote sensing applications, line positions, intensities, self- and nitrogen-broadened linewidths and their temperature dependences and pressure-induced shifts in line positions at room temperature were measured up to J' and N' = 22 for the oxygen A band at 13 122 cm(-1). Line intensities were obtained with 1% precisions and 2% absolute accuracies using absorption spectra recorded at Doppler-limited (0.02 cm(-1)) resolution with the McMath Fourier transform spectrometer (FTS) located at Kitt Peak National Observatory/National Solar Observatory in Arizona. The oxygen line positions were calibrated using near-infrared transitions of the 2-0 and 3-0 bands of CO as secondary standards. The intensities and positions of seven H(2)O lines near 13 900 cm(-1) were also remeasured to validate the FTS performance. The O(2) intensities fell within 1% of the values currently assumed for the molecular databases, but it was found that broadening coefficients and line positions should be revised for the A band of molecular oxygen. Copyright 2000 Academic Press.

Use of sublimation to prepare solid microbial media with water-insoluble substrates

A method was developed to deposit a visible layer of water-insoluble compounds via sublimation onto the surface of solid media. The compound is sublimed from a heated aluminum dish containing the compound onto the surface of an inverted, ice-cooled, inoculated agar petri dish. The method results in the deposition of a thin, even layer on the agar surface without the use of solvent. After incubation, clearing zones around colonies indicate the presence of compound-degrading microorganisms.

The NMR structure of the 5S rRNA E-domain-protein L25 complex shows preformed and induced recognition

The structure of the complex between ribosomal protein L25 and a 37 nucleotide RNA molecule, which contains the E-loop and helix IV regions of the E-domain of Escherichia coli 5S rRNA, has been determined to an overall r.m.s. displacement of 1.08 A (backbone heavy atoms) by heteronuclear NMR spectroscopy (Protein Databank code 1d6k). The interacting molecular surfaces are bipartite for both the RNA and the protein. One side of the six-stranded beta-barrel of L25 recognizes the minor groove of the E-loop with very little change in the conformations of either the protein or the RNA and with the RNA-protein interactions occurring mainly along one strand of the E-loop duplex. This minor groove recognition module includes two parallel beta-strands of L25, a hitherto unknown RNA binding topology. Binding of the RNA also induces conversion of a flexible loop to an alpha-helix in L25, the N-terminal tip of which interacts with the widened major groove at the E-loop/helix IV junction of the RNA. The structure of the complex reveals that the E-domain RNA serves as a preformed docking partner, while the L25 protein has one preformed and one induced recognition module.