David Astill
Flinders Medical Centre
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Featured researches published by David Astill.
Hpb | 2010
John W. Chen; Mayank Bhandari; David Astill; Thomas G. Wilson; Lilian Kow; Mark Brooke-Smith; James Toouli; Robert Padbury
BACKGROUND Accurate and simple prognostic criteria based on histopathology following pancreaticoduodenectomy would be helpful in assessing prognosis and considering and evaluating adjuvant therapy. This study analysed the histological parameters influencing outcome following pancreaticoduodenectomy for periampullary malignancy. METHODS A total of 110 pancreaticoduodenectomies were performed from 1998 to 2008. The median age of patients was 69 years (range 20-89 years). The median follow-up was 4.9 years. Of the procedures, 87% (96) were performed for malignancies and the remainder (n= 14) for benign aetiologies. Of the 96 malignancies, 60 were pancreatic adenocarcinoma and the rest were ampullary (14), cholangio (9), duodenal (9) carcinomas and others. Statistical analysis was performed using log-rank and Cox regression multivariate analyses. RESULTS Patients who underwent resection had 1-, 3- and 5-year survival rates of 70%, 46% and 41%, respectively. The 1-, 3- and 5-year survival rates for periampullary cancers other than pancreatic adenocarcinoma were 83%, 69% and 61%, respectively; those for pancreatic adenocarcinoma were 62%, 31% and 27%, respectively (P < 0.003). Poor tumour differentiation (P < 0.02), tumour size >3 cm (P < 0.04), margin <or=2 mm (P < 0.02), nodal involvement (P < 0.003), perineural infiltration (P < 0.0001) and lymphovascular invasion (P < 0.002) were associated with poorer prognosis. In a multivariate analysis, histologically identified perineural infiltration (P < 0.03) and lymphovascular invasion (P= 0.05) were significant factors influencing outcome. Five-year survival was 77% in patients negative for both factors and 15% in patients positive for both (P < 0.0001). In the pancreatic adenocarcinoma subgroup, patients who were negative for both factors had a 5-year survival of 71%, whereas those who were positive for both had a 5-year survival of 16% (P < 0.02). CONCLUSIONS The presence of perineural infiltration and lymphovascular invasion on histopathology is highly significant in predicting 5-year outcomes after pancreaticoduodenectomy for periampullary and pancreatic malignancies.
Annals of Surgery | 2007
Tim Bright; David I. Watson; William Tam; Philip A. Game; David Astill; Roger Ackroyd; Bas P. L. Wijnhoven; Peter G. Devitt; Mark Schoeman
Objective:To determine the efficacy of endoscopic argon plasma coagulation (APC) for ablation of Barrett esophagus. Summary Background Data:APC has been used to ablate Barrett esophagus. However, the long-term outcome of this treatment is unknown. This study reports 5-year results from a randomized trial of APC versus surveillance for Barrett esophagus in patients who had undergone a fundoplication for the treatment of gastroesophageal reflux. Methods:Fifty-eight patients with Barrett esophagus were randomized to undergo either ablation using APC or ongoing surveillance. At a mean 68 months after treatment, 40 patients underwent endoscopy follow-up. The efficacy of treatment, durability of the neosquamous re-epithelialization, and safety of the procedure were determined. Results:Initially, at least 95% ablation of the metaplastic mucosa was achieved in all treated patients. At the 5-year follow-up, 14 of 20 APC patients continued to have at least 95% of their previous Barrett esophagus replaced by neosquamous mucosa, and 8 of these had complete microscopic regression of the Barrett esophagus. Five of the 20 surveillance patients had more than 95% regression of their Barrett esophagus, and 4 of these had complete microscopic regression (1 after subsequent APC treatment). The length of Barrett esophagus shortened significantly in both study groups, although the extent of regression was greater after APC treatment (mean 5.9–0.8 cm vs. 4.6–2.2 cm). Two patients who had undergone APC treatment developed a late esophageal stricture, which required endoscopic dilation, and 2 patients in the surveillance group developed high-grade dysplasia during follow-up. Conclusions:Regression of Barrett esophagus after fundoplication is more likely, and greater in extent, in patients who undergo ablation with APC. In most patients treated with APC the neosquamous mucosa remains stable at up to 5-year follow-up. The development of high-grade dysplasia only occurred in patients who were not treated with APC.
Journal of Gastrointestinal Surgery | 2009
Willem A. Dijckmeester; Bas P. L. Wijnhoven; David I. Watson; Mary P. Leong; Michael Michael; George C. Mayne; Tim Bright; David Astill; Damian J. Hussey
IntroductionAblation of Barrett’s esophagus using Argon plasma coagulation (APC) is usually followed by the formation of a neosquamous epithelium. Investigating simple columnar or stratified squamous epithelium associated cytokeratin and microRNA (miRNA) expression in neo-squamous epithelium could help determine the identity and stability of the neosquamous epithelium.MethodsNine patients underwent ablation of Barrett’s esophagus with APC. Biopsies were collected from Barrett’s esophagus mucosa and proximal normal squamous epithelium before ablation, and from neosquamous and normal squamous epithelium after ablation. Additional esophageal mucosal biopsies from ten nonrefluxing subjects were used as a reference. RNA was extracted and real-time polymerase chain reaction was used to measure the expression of the cytokeratins CK-8 and CK-14 and the microRNAs miR-143 and miR-205.ResultsCK-8 and miR-143 expression were significantly higher in Barrett’s esophagus mucosa, compared to neosquamous and normal squamous epithelium before and after APC, whereas miRNA-205 and CK-14 expression was significantly lower in Barrett’s esophagus mucosa compared to all categories of squamous mucosa. The expression of CK-8, CK-14, miR-205, and miR-143 was similar between neosquamous epithelium compared to normal squamous epithelium in patients with Barrett’s esophagus. Only miR-143 expression was significantly higher in neosquamous and normal squamous epithelium before and after APC compared to normal squamous epithelium from control subjects (p < 0.004).ConclusionsThe expression levels of cytokeratins and miRNAs studied in post-ablation neosquamous epithelium and normal squamous epithelium in patients with Barrett’s esophagus are similar. In patients with Barrett’s esophagus, miR-143 expression is still elevated in both neosquamous mucosa, and the squamous mucosa above the metaplastic segment, suggesting that this mucosa may not be normal; i.e., it is different to that seen in subjects without Barrett’s esophagus. miR-143 could promote a Barrett’s epithelium gene expression pattern, and this could have a role in development of Barrett’s esophagus.
Australasian Journal of Dermatology | 2012
Emma Ryan; Gillian Marshman; David Astill
Toxic epidermal necrolysis (TEN)‐like presentations have been described in non–drug‐induced settings. We describe a case of subacute cutaneous lupus erythematosus (SCLE) in a 53‐year old woman, which evolved into a TEN‐like presentation over the course of 4 weeks. The patient responded rapidly to treatment with intravenous methylprednisolone. This article draws attention to features that may be used to differentiate classical TEN from TEN‐like SCLE.
BMC Research Notes | 2011
Sebastien Haiart; David I. Watson; Mary P. Leong; David Astill; Tim Bright; Damian J. Hussey
BackgroundProton pump inhibitor (PPI) medication and surgical fundoplication are used for the control of gastro-oesophageal reflux in patients with Barretts oesophagus, but differ in their effectiveness for both acid and bile reflux. This might impact on the inflammatory processes that are associated with progression of Barretts oesophagus to cancer, and this may be evident in the gene expression profile and microRNA expression pattern in Barretts oesophagus mucosa. We hypothesised that two miRNAs with inflammatory and oncogenic roles, miR-101 and miR-196a, are differentially expressed in Barretts oesophagus epithelium in patients with reflux treated medically vs. surgically.FindingsMucosal tissue was obtained at endoscopy from patients with Barretts oesophagus whose reflux was controlled by proton pump inhibitor (PPI) therapy (n = 20) or by fundoplication (n = 19). RNA was extracted and the expression of miR-101 and miR-196a was measured using real-time reverse transcription - polymerase chain reaction. There were no significant differences in miR-101 and miR-196a expression in Barretts oesophagus epithelium in patients treated by PPI vs. fundoplication (p = 0.768 and 0.211 respectively). Secondary analysis showed a correlation between miR-196a expression and Barretts oesophagus segment length (p = 0.014).ConclusionThe method of reflux treatment did not influence the expression of miR-101 and miR-196a in Barretts oesophagus. This data does not provide support to the hypothesis that surgical treatment of reflux better prevents cancer development in Barretts oesophagus. The association between miR-196a expression and Barretts oesophagus length is consistent with a tumour promoting role for miR-196a in Barretts oesophagus.
World Journal of Gastroenterology | 2017
Loveena Sreedharan; George C. Mayne; David I. Watson; Timothy Bright; Reginald V. Lord; Alfiya Ansar; Tingting Wang; Jakob Kist; David Astill; Damian J. Hussey
AIM To investigate the microRNA expression profile in esophageal neosquamous epithelium from patients who had undergone ablation of Barrett’s esophagus. METHODS High throughput screening using TaqMan® Array Human MicroRNA quantitative PCR was used to determine expression levels of 754 microRNAs in distal esophageal mucosa (1 cm above the gastro-esophageal junction) from 16 patients who had undergone ablation of non-dysplastic Barrett’s esophagus using argon plasma coagulation vs pretreatment mucosa, post-treatment proximal normal non-treated esophageal mucosa, and esophageal mucosal biopsies from 10 controls without Barrett’s esophagus. Biopsies of squamous mucosa were also taken from 5 cm above the pre-ablation squamo-columnar junction. Predicted mRNA target pathway analysis was used to investigate the functional involvement of differentially expressed microRNAs. RESULTS Forty-four microRNAs were differentially expressed between control squamous mucosa vs post-ablation neosquamous mucosa. Nineteen microRNAs were differentially expressed between post-ablation neosquamous and post-ablation squamous mucosa obtained from the more proximal non-treated esophageal segment. Twelve microRNAs were differentially expressed in both neosquamous vs matched proximal squamous mucosa and neosquamous vs squamous mucosa from healthy patients. Nine microRNAs (miR-424-5p, miR-127-3p, miR-98-5p, miR-187-3p, miR-495-3p, miR-34c-5p, miR-223-5p, miR-539-5p, miR-376a-3p, miR-409-3p) were expressed at higher levels in post-ablation neosquamous mucosa than in matched proximal squamous and healthy squamous mucosa. These microRNAs were also more highly expressed in Barrett’s esophagus mucosa than matched proximal squamous and squamous mucosa from controls. Target prediction and pathway analysis suggests that these microRNAs may be involved in the regulation of cell survival signalling pathways. Three microRNAs (miR-187-3p, miR-135b-5p and miR-31-5p) were expressed at higher levels in post-ablation neosquamous mucosa than in matched proximal squamous and healthy squamous mucosa. These miRNAs were expressed at similar levels in pre-ablation Barrett’s esophagus mucosa, matched proximal squamous and squamous mucosa from controls. Target prediction and pathway analysis suggests that these microRNAs may be involved in regulating the expression of proteins that contribute to barrier function. CONCLUSION Neosquamous mucosa arising after ablation of Barrett’s esophagus expresses microRNAs that may contribute to decreased barrier function and microRNAs that may be involved in the regulation of survival signaling pathways.
Clinical and Experimental Gastroenterology | 2009
Plauto E. Beck; George C. Mayne; David Astill; Tanya S Irvine; David I. Watson; Willem A. Dijckmeester; Bas P. L. Wijnhoven; Damian J. Hussey
Objectives: To determine if histopathologic assessment of esophageal biopsies harvested for research study is justified due to the heterogeneity of tissues in the esophagus, and the consequent histopathologic mis-matches with the clinical histopathology of biopsies taken at the same level. Methods: Since 2004, patients undergoing upper endoscopy for a variety of clinical conditions were invited to provide additional esophageal biopsies; those were collected for research purpose at the same level as biopsies collected for clinical histopathology. Research biopsies were cut in two parts: one part was submitted to research histopathology and the other stored for molecular analysis. Results of clinical histopathology for each patient were summarized per biopsy level and compared to results obtained from research biopsies at the corresponding level. Results: A total of 377 level summaries were obtained from 137 patients. Clinical histopathology summaries classified 123 levels (32.6%) as squamous epithelium, 84 levels (22.3%) as metaplastic columnar-lined epithelium, 135 levels (35.8%) as columnar-lined epithelium with intestinal metaplasia, 30 levels (8%) as dysplasia, and 5 levels (1.3%) as adenocarcinoma. Research histopathology matched to clinical summaries on 120 of 123 (97.5%) levels for squamous epithelium, 52 of 84 (61.9%) for metaplastic columnar-lined epithelium, and 94 of 135 (69.5%) for columnar-lined epithelium with intestinal metaplasia. There were no matches for dysplasia between the groups; however, they agreed on all five cases of AC. On 59 (70.2%) metaplastic columnar-lined epithelium levels and on 62 (46%) columnar-lined epithelium with intestinal metaplasia levels, tissue heterogeneity was observed in clinical histopathology, with portions of squamous epithelium within the samples. Matches with pure tissue samples in both clinical and research histopathology levels were observed on 22 (26.2%) levels of metaplastic columnar-lined epithelium and in 55 (40.7%) levels of columnar-lined epithelium with intestinal metaplasia. Conclusions: The high proportion of mismatches and tissue heterogeneity observed, especially among columnar-lined epithelium with intestinal metaplasia and dysplasia, points to the necessity of determining the histopathology of the research samples to avoid sampling errors during molecular studies.
Annals of Surgical Oncology | 2018
Karen Chiam; George C. Mayne; David I. Watson; Richard J. Woodman; Tim Bright; Michael Michael; Christos Stelios Karapetis; Tanya S Irvine; Wayne A. Phillips; Richard Hummel; Tingting Wang; Letitia Pimlott; Shashikanth Marri; David Astill; Andrew Ruszkiewicz; Sarah K. Thompson; Damian J. Hussey
BackgroundClinical trials report improved overall survival following neoadjuvant chemoradiotherapy in patients undergoing surgery for esophageal adenocarcinoma, with a 10–15% survival improvement. MicroRNAs (miRNAs) are small noncoding RNAs that are known to direct the behavior of cancers, including response to treatment. We investigated the ability of miRNAs to predict outcomes after neoadjuvant chemoradiotherapy.MethodsEndoscopic biopsies from esophageal adenocarcinomas were obtained before neoadjuvant chemoradiotherapy and esophagectomy. miRNA levels were measured in the biopsies using next generation sequencing and compared with pathological response in the surgical resection, and subsequent survival. miRNA ratios that predicted pathological response were identified by Lasso regression and leave-one-out cross-validation. Association between miRNA ratio candidates and relapse-free survival was assessed using Kaplan–Meier analysis. Cox regression and Harrell’s C analyses were performed to assess the predictive performance of the miRNAs.ResultsTwo miRNA ratios (miR-4521/miR-340-5p and miR-101-3p/miR-451a) that predicted the pathological response to neoadjuvant chemoradiotherapy were found to be associated with relapse-free survival. Pretreatment expression of these two miRNA ratios, pretreatment tumor differentiation, posttreatment AJCC histopathological tumor regression grading, and posttreatment tumor clearance/margins were significant factors associated with survival in Cox regression analysis. Multivariate analysis of the two ratios together with pretherapy factors resulted in a risk prediction accuracy of 85% (Harrell’s C), which was comparable with the prediction accuracy of the AJCC treatment response grading (77%).ConclusionsmiRNA-ratio biomarkers identified using next generation sequencing can be used to predict disease free survival following neoadjuvant chemoradiotherapy and esophagectomy in patients with esophageal adenocarcinoma.
Hpb | 2015
Manju D. Chandrasegaram; Ali Shah; John W. Chen; Andrew Ruszkiewicz; David Astill; Georgina England; Ravish S. Raju; Eu Ling Neo; Paul M. Dolan; Chuan Ping Tan; Mark Brooke‐Smith; Thomas G. Wilson; Robert Padbury; Christopher S. Worthley
BACKGROUND The role of hormones in focal nodular hyperplasia (FNH) has been investigated with conflicting results. OBJECTIVE The aim of this study was to evaluate oestrogen and progesterone receptor immunohistochemical expression in FNH and surrounding normal liver (control material). METHODS Biopsy materials from FNH and control tissue were investigated using an immunostainer. Receptor expression was graded as the proportion score (percentage of nuclear staining) and oestrogen receptor intensity score. RESULTS Study material included tissue from 11 resected FNH lesions and two core biopsies in 13 patients (two male). Twelve samples showed oestrogen receptor expression. The percentage of nuclear oestrogen receptor staining was <33% in eight FNH biopsies, 34-66% in two FNH biopsies, and >67% in both core biopsies. The better staining in core biopsies relates to limitations of the staining technique imposed by the fibrous nature of larger resected FNH. Control samples from surrounding tissue were available for nine of the resected specimens and all showed oestrogen receptor expression. Progesterone receptor expression was negligible in FNH and control samples. CONCLUSIONS By contrast with previous studies, the majority of FNH and surrounding liver in this cohort demonstrated oestrogen receptor nuclear staining. The implications of this for continued oral contraceptive use in women of reproductive age with FNH remain uncertain given the lack of consistent reported growth response to oestrogen stimulation or withdrawal.
Australasian Journal of Dermatology | 2015
Christopher Ross; Nicholas De Rosa; Gillian Marshman; David Astill
A 52‐year old woman with chronic renal failure presented with tender buttock nodules, bilateral non‐tender periocular papules and yellow scleral plaques. The patient then developed sclerodermoid changes of the hands, as well as woody induration, oedema and hyperpigmentation of lower limbs. There was no previous exposure to gadolinium contrast. Her histology and clinical features were consistent with nephrogenic systemic fibrosis. Treatment with oral sirolimus resulted in a marked reduction of induration and oedema, and an improvement in distal upper limb and lower limb joint mobility.