Use of severity classification systems in the surgical decision-making process in emergency laparotomy for perforated diverticulitis

Purpose: Hartman's procedure (HP) or primary anastomosis (PA) are the two surgical techniques used in patients undergoing emergency colectomy for perforated diverticulitis. There are no objective criteria to guide the surgeon's choice of procedure. This study assesses whether classification and scoring systems can be used in the decision-making process. Methods: One hundred eleven patients undergoing emergency laparotomy for perforated diverticulitis were analyzed. Logistic regression and interaction models were used to determine the predictive value in the two settings. Results: Sixty five patients underwent HP and 46 patients underwent PA. Patients with HP had significantly higher scores, median age, and were more often on immunosuppressive medication. Mortality and surgical morbidity did not differ between the groups. The clinical anastomotic leak rate was 28.3% in the PA group. In the univariate logistic regression for in-hospital death, all scores showed a significant influence. The multivariate logistic regression analysis showed that only Charlson comorbidity index (CCI) and American Society of Anesthesiologists score had a significant influence on mortality. Each score was analyzed for its predictive value regarding mortality and morbidity with respect to type of operative procedure. Only CCI revealed a trend towards statistical significance. The risk of death increases with increasing CCI when PA is performed compared to HP. Conclusion: None of the tested scores can be used to help the surgeon decide whether a PA or HP is appropriate in a specific patient. Comorbidity, represented as CCI in this study, might be more important than the locoregional situatio

Identification of a rhythmic firing pattern in the enteric nervous system that generates rhythmic electrical activity in smooth muscle

The enteric nervous system (ENS) contains millions of neurons essential for organization of motor behavior of the intestine. It is well established that the large intestine requires ENS activity to drive propulsive motor behaviors. However, the firing pattern of the ENS underlying propagating neurogenic contractions of the large intestine remains unknown. To identify this, we used high-resolution neuronal imaging with electrophysiology from neighboring smooth muscle. Myoelectric activity underlying propagating neurogenic contractions along murine large intestine [also referred to as colonic migrating motor complexes, (CMMCs)] consisted of prolonged bursts of rhythmic depolarizations at a frequency of ∼2 Hz. Temporal coordination of this activity in the smooth muscle over large spatial fields (∼7 mm, longitudinally) was dependent on the ENS. During quiescent periods between neurogenic contractions, recordings from large populations of enteric neurons, in mice of either sex, revealed ongoing activity. The onset of neurogenic contractions was characterized by the emergence of temporally synchronized activity across large populations of excitatory and inhibitory neurons. This neuronal firing pattern was rhythmic and temporally synchronized across large numbers of ganglia at ∼2 Hz. ENS activation preceded smooth muscle depolarization, indicating rhythmic depolarizations in smooth muscle were controlled by firing of enteric neurons. The cyclical emergence of temporally coordinated firing of large populations of enteric neurons represents a unique neural motor pattern outside the CNS. This is the first direct observation of rhythmic firing in the ENS underlying rhythmic electrical depolarizations in smooth muscle. The pattern of neuronal activity we identified underlies the generation of CMMCs

Ascending excitatory neural pathways modulate slow phasic myogenic contractions in the isolated human colon

This is the accepted version of the following article: [Carbone, S. E., Dinning, P. G., Costa, M., Spencer, N. J., Brookes, S. J. H. and Wattchow, D. A. (2013), Ascending excitatory neural pathways modulate slow phasic myogenic contractions in the isolated human colon. Neurogastroenterology & Motility, 25: 670–e510.], which has been published in final form at [http://dx.doi.org/10.1111/nmo.12129]. In addition, authors may also transmit, print and share copies with colleagues, provided that there is no systematic distribution of the submitted version, e.g. posting on a listserve, network or automated delivery.Background In animal models, enteric reflex pathways have potent effects on motor activity; their roles have been much less extensively studied in human gut. The aim of this study was to determine if ascending excitatory interneuronal pathways can modulate spontaneous phasic contractions in isolated preparations of human colonic circular muscle. Methods Human colonic preparations were cut into T shapes, with vertical bar of the ‘T’ pharmacologically isolated. Electrical stimulation and the nicotinic agonist, 1,1-dimethyl-4-phenylpiperazinium iodide (DMPP), were applied to the isolated region and circular muscle contractile activity was measured from the cross-bar of the T, more than 10 mm orally from the region of stimulation. Key Results The predominant form of spontaneous muscle activity consisted of tetrodotoxin-resistant, large amplitude, slow phasic contractions (SPCs), occurring at average intervals of 124 ± 68 s. Addition of a high concentration of hexamethonium (1 mmol L-1) to the superfusing solution significantly increased the interval between SPCs to 278.1 ± 138.3 s (P < 0.005). Focal electrical stimulation more than 10 mm aboral to the muscle recording site advanced the onset of the next SPC, and this effect persisted in hexamethonium. However, the effect of electrical stimulation was blocked by tetrodotoxin (TTX, 1 µmol L-1). Application of the nicotinic agonist DMPP (1 mmol L-1) to the aboral chamber often stimulated a premature SPC (n = 4). Conclusions & Inferences The major form of spontaneous contractility in preparations of human colonic circular muscle is SPCs, which are myogenic in origin. Activation of ascending excitatory neural pathways, which involve nicotinic receptors, can modulate the timing of SPCs and thus influence human colonic motility.Australian National Health & Medical Research Counci

‘Through the unknown, remembered gate’: the Brian Nettleton lecture – Outdoors Victoria conference, 2022

This paper is an adapted version of the Brian Nettleton Lecture given at the Outdoors Victoria Conference, 2022. It explores how the last two decades have seen an ever-accelerating Digital Revolution which has impacted on almost every aspect of human experience to the point that it is now omnipresent. Life is now mediated through the screen. As a result, children and young people have become hyper-vigilant, overly anxious, experience a sense of climate trauma, and have decreasing access to, and time spent in, the outdoors. In addition, children have just experienced two years of isolation as a result of the Covid-19 pandemic and evidence suggests that they are already experiencing significant mental health issues as a result. This paper considers the implications of this for Outdoors Victoria and Outdoor Education. © The Author(s) 2023

Sociodemographic disparities in survival from colorectal cancer in South Australia: a population-wide data linkage study

Copyright © Beckmann et al. 2016 Open AccessThis article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.Background: Inequalities in survival from colorectal cancer (CRC) across socioeconomic groups and by area of residence have been described in various health care settings. Few population-wide datasets which include clinical and treatment information are available in Australia to investigate disparities. This study examines socio-demographic differences in survival for CRC patients in South Australia (SA), using a population-wide database derived via linkage of administrative and surveillance datasets. Methods: The study population comprised all cases of CRC diagnosed in 2003-2008 among SA residents aged 50-79 yrs in the SA Central Cancer Registry. Measures of socioeconomic status (area level), geographical remoteness, clinical characteristics, comorbid conditions, treatments and outcomes were derived through record linkage of central cancer registry, hospital-based clinical registries, hospital separations, and radiotherapy services data sources. Socio-demographic disparities in CRC survival were examined using competing risk regression analysis. Results: Four thousand six hundred and forty one eligible cases were followed for an average of 4.7 yrs, during which time 1525 died from CRC and 416 died from other causes. Results of competing risk regression indicated higher risk of CRC death with higher grade (HR high v low =2.25, 95 % CI 1.32-3.84), later stage (HR C v A = 7.74, 95 % CI 5.75-10.4), severe comorbidity (HR severe v none =1.21, 95 % CI 1.02-1.44) and receiving radiotherapy (HR = 1.41, 95 % CI 1.18-1.68). Patients from the most socioeconomically advantaged areas had significantly better outcomes than those from the least advantaged areas (HR =0.75, 95 % 0.62-0.91). Patients residing in remote locations had significantly worse outcomes than metropolitan residents, though this was only evident for stages A-C (HR = 1.35, 95 % CI 1.01-1.80). These disparities were not explained by differences in stage at diagnosis between socioeconomic groups or area of residence. Nor were they explained by differences in patient factors, other tumour characteristics, comorbidity, or treatment modalities. Conclusions: Socio-economic and regional disparities in survival following CRC are evident in SA, despite having a universal health care system. Of particular concern is the poorer survival for patients from remote areas with potentially curable CRC. Reasons for thes

Discovery and validation of molecular biomarkers for colorectal adenomas and cancer with application to blood testing

Results: Genome-wide analysis uncovered reproducible gene expression signatures for both adenomas and cancers compared to controls. 386/489 (79%) of the adenoma and 439/529 (83%) of the adenocarcinoma biomarkers were validated in independent tissues. We also identified genes differentially expressed in adenomas compared to cancer. KIAA1199 was selected for further analysis based on consistent up-regulation in neoplasia, previous studies and its interest as an uncharacterized gene. Plasma KIAA1199 RNA levels were significantly higher in patients with either cancer or adenoma (31/ 40) compared to neoplasia-free controls (6/20).This work was co-funded by Flinders University of South Australia and the Commonwealth Scientific and Industrial Research Organisation (CSIRO) of Australia. Drs. Dunne, Molloy and Brown are employed by CSIRO. These funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. Funding was also provided by Clinical Genomics Pty Ltd., a company involved in the discovery and commercialization of biomarkers for colorectal cancer. Drs. LaPointe, Pedersen, Gaur, McEvoy and Thomas are employed by Clinical Genomics Pty Ltd and Prof. Young is a paid consultant of Clinical Genomics Pty Ltd. The funder thus played roles in study design, data collection and analysis, decision to publish, and preparation of the manuscript. Mrs. Pimlott and Dr. Wattchow have nothing to disclose. This work was co-funded by Clinical Genomics Pty Ltd, a company involved in the discovery and commercialization of biomarkers for colorectal cancer. Drs. LaPointe, Pedersen, Gaur, McEvoy and Thomas are employed by Clinical Genomics Pty Ltd. Prof. Young is a paid consultant of Clinical Genomics Pty Ltd. This does not alter the authors’ adherence to all the PLoS ONE policies on sharing data and materials

Identification of unique release kinetics of serotonin from guinea-pig and human enterochromaffin cells

This is the accepted version of the following article: [Raghupathi, R., Duffield, M. D., Zelkas, L., Meedeniya, A., Brookes, S. J. H., Sia, T. C., Wattchow, D. A., Spencer, N. J. and Keating, D. J. (2013), Identification of unique release kinetics of serotonin from guinea-pig and human enterochromaffin cells. The Journal of Physiology, 591: 5959–5975. doi: 10.1113/jphysiol.2013.259796], which has been published in final form at [http://dx.doi.org/10.1113/jphysiol.2013.259796]. In addition, authors may also transmit, print and share copies with colleagues, provided that there is no systematic distribution of the submitted version, e.g. posting on a listserve, network or automated delivery

“Immersed within the rock itself” : student experiences rock climbing in outdoor education

Outdoor education has a long tradition of using adventurous activities like rock climbing to achieve learning outcomes. Concepts like adventure, perceived risk, and flow have been used to justify the inclusion of these activities. However, the arguments for their inclusion have been eroded in recent decades, leading the authors of this paper to ask: How do students actually experience an activity like rockclimbing? In addition, outdoor activities/sports have often been grouped together, as if they were one activity, rather than distinct activities, that may require specific pedagogic considerations. This paper presents the findings of research into one group of secondary school students and their experiences rock climbing while on an OE camp at Mt Arapiles/ Dyurrite in Victoria, Australia. It re-tells their stories about two climbing contexts - top rope and multi pitch climbing. Data collected through interviews were used to retell the student’s stories about their climbing experiences and inform our analysis of how rockclimbing practices may be modified to better suit evolving ideas within outdoor education. The study highlights the impact that guides have on student’s experiences and the need for program design to be guided by intended learning outcomes. Finally, we recommend more research into students’ lived experiences across the OE curriculum to develop more nuanced outdoor education programs. © 2022, The Author(s)

Contesting authentic practice and ethical authority in adventure tourism

This paper examines the discourses of authenticity and ethics used among adventure tourists regarding the use of the natural environment. In one case, full-time traveling rock climbers use their dedication to the sport and annual visits to the Red River Gorge as evidence for their authoritative voice on ethical climbing practice. While they identify the growing numbers of leisure climbers as a problem for sustainability, many also take up temporary employment as guides and are directly involved in the introduction of new climbers to the area. In another case, two groups of wilderness enthusiasts – “ADK 46ers” and “Summit Stewards” – lament the environmental and social impacts of other recreational users in the Adirondack Park. Despite being visitors themselves, Summit Stewards and 46ers use their sense of place and knowledge of Adirondack history and ecology to substantiate their authority as purveyors of ethical practice. In both cases, senses of responsibility are inspired by senses of place, but are articulated through notions of authenticity and used as justification for ethical authority. While validating their presence in these outdoor spaces, the use of such rhetoric also minimizes their own impacts yielding further tensions among user groups