Publications by authors named "Simon J Harper"

Background: Acute abdominal pain is a common surgical presentation. We previously found that over the last decade, more patients were admitted to hospital with non-surgical diagnoses (e.g.

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Background: Acute abdominal pain is a common surgical presentation with a wide range of causes. Differentiating urgent patients from non-urgent patients is important to optimise patient outcomes and the use of hospital resources. The aim of this study was to determine how accurately urgent and non-urgent patients presenting with abdominal pain can be identified.

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Background: Delays to surgery for patients requiring an acute operation are associated with increased morbidity and mortality. A recent study from our institution observed long waiting times for patients booked for an acute operation. The aim of this study was to evaluate the patient's progress from presentation to arrival in the operating theatre and to identify where delays occurred.

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Article Synopsis
  • The study aimed to identify factors that predict survival after pancreaticoduodenectomy for ampullary cancer and to create a survival prediction model.
  • It analyzed data from 110 patients treated between 2002 and 2013, categorizing them into three nodal subgroups based on the extent of cancer spread to lymph nodes.
  • The results showed varying survival rates depending on the cancer staging, with vascular invasion and lymph node ratio identified as key independent predictors of survival, leading to the development of a prognostic model for clinical use.
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Exocrine drainage following pancreas transplantation can be achieved by drainage into the bladder or bowel, the latter typically by direct duodeno-jejunostomy; the use of Roux-en-Y enteric drainage is uncommon. We report a retrospective analysis of a single-centre experience of Roux-en-Y enteric drainage following pancreas transplantation. Over a 14-year period (2001-2015), 204 consecutive adult pancreas transplants were performed (96.

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Chronic rejection of solid organ allografts remains the major cause of transplant failure. Donor-derived tissue-resident lymphocytes are transferred to the recipient during transplantation, but their impact on alloimmunity is unknown. Using mouse cardiac transplant models, we show that graft-versus-host recognition by passenger donor CD4 T cells markedly augments recipient cellular and humoral alloimmunity, resulting in more severe allograft vasculopathy and early graft failure.

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Adaptive CD8 T-cell immunity is the principal arm of the cellular alloimmune response, but its development requires help. This can be provided by CD4 T cells that recognize alloantigen "indirectly," as self-restricted allopeptide, but this process remains unexplained, because the target epitopes for CD4 and CD8 T-cell recognition are "unlinked" on different cells (recipient and donor antigen presenting cells (APCs), respectively). Here, we test the hypothesis that the presentation of intact and processed MHC class I alloantigen by recipient dendritic cells (DCs) (the "semidirect" pathway) allows linked help to be delivered by indirect-pathway CD4 T cells for generating destructive cytotoxic CD8 T-cell alloresponses.

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Background: Post-operative pancreatic fistula (POPF) is the major source of morbidity following pancreaticoduodenectomy. A predictive indicator would be highly advantageous. One potential marker is drain amylase concentration (DAC).

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Background: Equestrian sports are common outdoor activities that may carry a risk of liver injury. Due to the relative infrequency of equestrian accidents the injury patterns and outcomes associated with liver trauma in these patients have not been well characterized.

Methods: We examined our experience of the management of equestrian liver trauma in our regional hepatopancreaticobiliary unit at a tertiary referral center.

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Background And Objectives: Actual long-term survival of patients with colorectal liver metastases staged by PET CT has not been reported. Objectives were to investigate whether PET CT staging results in actual improved long-term survival, to examine outcome in patients with 'equivocal' PET CT scans, and those excluded from hepatectomy by PET CT.

Methods: A retrospective analysis of patients undergoing hepatectomy for colorectal liver metastases between March 1998 and September 2008.

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It is essential to minimize the unnecessary discard of procured deceased donor kidneys, but information on discard rates and the extent to which discard can be avoided are limited. Analysis of the UK Transplant Registry revealed that the discard rate of procured deceased donor kidneys has increased from 5% in 2002-3 to 12% in 2011-12. A national offering system for hard-to-place kidneys was introduced in the UK in 2006 (the Declined Kidney Scheme), but just 13% of kidneys that were subsequently discarded until 2012 were offered through the scheme.

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In transplantation, direct-pathway CD8 T cells that recognize alloantigen on donor cells require CD4 help for activation and cytolytic function. The ability of indirect-pathway CD4 T cells to provide this help remains unexplained, because a fundamental requirement for epitope linkage is seemingly broken. The simultaneous presentation, by host dendritic cells (DCs), of both intact MHC class I alloantigen and processed alloantigen would deliver linked help, but has not been demonstrated definitively.

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Prolonged warm ischemia (WI) occurring in marginal kidney donors together with reperfusion injury determines allograft survival, in which apoptosis and inflammation play crucial roles. There is no single valid biomarker, so far, to assess the degree of kidney donor injury. To define new biomarkers for detecting initial donor ischemic injury, caspase-3, caspase-7, apoptosis, inflammation, HSP70 and renal histological changes were examined in porcine kidneys subjected to 7- 15- 25- or 40-min WI, two-hour cold storage and six-hour hemoreperfusion.

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Background: Sirolimus is unlicensed for use in liver transplantation because of concerns over safety, particularly in regard to hepatic artery thrombosis and excess mortality. However, sirolimus offers potential advantages over calcineurin inhibitor-based immunosuppression, relating to its renal sparing and antiproliferative properties.

Methods: A review was undertaken of 148 liver transplant patients converted to sirolimus over 10 years at a single center.

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Aim: 8-12% of colorectal cancers are associated with genetic syndromes. The most common of these is Lynch syndrome (also known as Hereditary Non-Polyposis Colorectal Cancer). Clinical criteria (Besthesda criteria) exist that can be used to identify colorectal cancer patients who may benefit from immunohistochemical screening of their tumour for Lynch syndrome.

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Acute pancreatitis (AP) is an important cause of morbidity and mortality worldwide and the annual incidence appears to be increasing. It presents as a mild self-limiting illness in 80% of patients. However, one-fifth of these develop a severe complicated life-threatening disease requiring intensive and prolonged therapeutic intervention.

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Background: Leucocytes play crucial roles in ischemia reperfusion injury that is inevitable in kidney transplantation. Leucocyte-depleted hemoreperfusion improved post-ischemic renal function was demonstrated in our previous study and its underlying mechanisms were further investigated in this study.

Methods: Porcine kidneys were subjected to 7 min warm ischemia and 2 h cold storage, and preserved by hemoreperfusion with or without leucocyte depletion for 6 h on an isolated organ perfusion system.

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Background: The initial flush of an organ is important to remove any cellular components from the microcirculation before storage. The aim of this study was to assess graft function after an ex vivo warm flush with a novel non-phosphate buffered preservation solution AQIX RS-I (AQIX) compared with a traditional cold flush.

Methods: Porcine kidneys were either warm-flushed with AQIX RS-I at 30°C, or cold-flushed at 4°C with University of Wisconsin solution (UW) or hyperosmolar citrate (HOC) preservation solution at a pressure of 100 cmH2O (n = 6).

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Background: The precise effect of warm ischemia on renal allograft function remains unclear and leads to variable warm ischemic time (WIT) limits advocated by transplant programs. This study aims to investigate the relationship between WIT, renal ischemia reperfusion injury, and graft function using a hemoperfused kidney model.

Methods: Porcine kidneys were perfused with normothermic blood on an isolated organ perfusion system.

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The optimal kidney preservation system and methods to ameliorate reperfusion injury are major factors in accomplishing successful graft function following transplantation. Ischaemia and reperfusion lead to cellular stress and the adaptive response may include the activation of genes involved in cellular protection and/or cell death by apoptosis. We investigated the expression of cytoprotective heme oxygenase-1 (HO-1), anti-apoptotic Bcl-2 and pro-apoptotic Bax after 6 h isolated organ perfusion in porcine kidneys that had been given 10 and 40 min warm ischaemic time.

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The aim of this study was to assess the viability and function of renal allografts under normothermic conditions using a novel nonphosphate buffered preservation solution AQIXRS-I. Porcine kidneys were flushed at 30 degrees C with AQIXRS-I at 100 mmHg pressure after 5-10 min warm ischaemic time and stored statically at either 4 degrees C or 30 degrees C for 2 h (n = 6 per group). Assessment of renal function by physiological and biochemical parameters was performed by perfusing the organs with autologous blood at 37 degrees C, with an initial circulating serum creatinine concentration of 1000 mumol/l on an isolated organ perfusion system for 6 h.

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Ischaemia-reperfusion (IR) injury is known to be a risk factor influencing both short and long-term graft function following transplantation. The pathophysiology of IR injury is suggested to involve elevated reactive oxygen species production resulting in oxidative damaged cellular macromolecules. The objective of this study was to evaluate oxidative damage following IR using an isolated organ perfusion model of the transplanted kidney, in order to determine a simple, preferably non-invasive biomarker for IR injury.

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Objective: To compare the anatomy and function of right and left kidneys retrieved by laparoscopic live donor nephrectomy (LDN).

Patients And Methods: In all, 84 transperitoneal LDNs were performed, 66 left and 18 right. Two different right-sided LDN techniques were used: initially, the inferior vena cava (IVC) was controlled with a Satinsky clamp introduced through a 6-8 cm right upper quadrant incision, through which the kidney was also removed (six patients).

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