Real-time analysis of living animals and rapid screening of human fluid samples using remote sampling electrospray ionization mass spectrometry.

Real-time and in-situ mass-spectrometry analyses of living animal and biological sample were performed using a novel remote sampling electrospray ionization (RS-ESI) probe. Unlike conventional ESI, in which injection or syringe loading is required for sample introduction, the RS-ESI probe ionizes the samples when the sampling capillary is in contact with the sample. As the sampling capillary is electrically held at ground potential, the safety of the animal and operator is assured. The liquid sample is aspirated to the ESI emitter at the other end of the capillary by the Venturi effect. Subsequently, the electrospray is generated when a high voltage is applied to the counter electrode placed inside the ion source chamber. The probe unit is attached to the mass spectrometer with a long flexible tube and its position can be freely manipulated during the analysis. In this report, we demonstrate a real-time analysis of a living mouse liver and an automatic analysis of 138 serum samples using this new technique.

Ex vivo normothermic porcine pancreas: A physiological model for preservation and transplant study.

INTRODUCTION: An ex vivo normothermic porcine pancreas perfusion (ENPPP) model was established to investigate effects of machine perfusion pressures on graft preservation. METHODOLOGY: Nine porcine pancreata were perfused with autologous blood at 50 mmHg (control) pressure. Graft viability was compared against four ex-vivo porcine pancreata perfused at 20 mmHg ('low') pressure. Arterio-venous oxygen gas differentials, biochemistry, and graft insulin responses to glucose stimulation were compared. Immunohistochemistry stains compared the cellular viability. RESULTS: Control pancreata were perfused for a median of 3 h (range 2-4 h) with a mean pressure 50 mmHg and graft flow 141 mL min-1. In comparison, all of the 'low' pressure models were perfused for 4 h, with mean perfusion pressure 20 mmHg and graft flow 40 mL.min-1. All pancreata demonstrated cellular viability with evidence of oxygen consumption with preserved endocrine and exocrine function. However, following statistical analysis, the 'low' pressure perfusion of porcine pancreata compared favourably in important biochemical and immunohistochemistry cellular profiles; potentially arguing for an improved method for graft preservation. CONCLUSION: ENPPP will facilitate whole organ preservation to be studied in further detail and avoids use of expensive live animals. ENPPP is reproducible and mimics a "donation after circulatory death" scenario.

Ex Vivo Porcine Organ Perfusion Models as a Suitable Platform for Translational Transplant Research.

In transplantation surgery, extending the criteria for organ donation to include organs that may have otherwise been previously discarded has provided the impetus to improve organ preservation. The traditional method of cold static storage (CS) has been tried and tested and is suitable for organs meeting standard criteria donation. Ex vivo machine perfusion is, however, associated with evidence suggesting that it may be better than CS alone and may allow for organ donation criteria to be extended. Much of our knowledge of organ preservation is derived from animal studies. We review ex vivo porcine organ perfusion models and discuss the relevance to the field of transplantation surgery. Following a systematic literature search, only articles that reported on experimental studies with focus on any aspect(s) of ex vivo and porcine perfusion of organs yet limited to the context of organ transplantation surgery were included. The database search and inclusion/exclusion criteria identified 22 journal articles. All 22 articles discussed ex vivo porcine organ perfusion within the context of transplant preservation surgery: 8 liver, 3 kidney, 3 lung, 2 pancreas/islet, 4 discussed a combined liver-kidney multiorgan model, 1 small bowel, and 1 cardiac perfusion model systems. The ex vivo porcine perfusion model is a suitable, reliable, and safe translational research model. It has advantages to investigate organ preservation techniques in a reproducible fashion in order to improve our understanding and has implications to extend the criteria for organ donation.

Current principles and practice in autologous intraportal islet transplantation: a meta-analysis of the technical considerations.

OBJECTIVES: Autologous islet transplantation (IAT) following pancreatectomy is now a recognized, albeit highly specialized procedure carried out in a small number of centers worldwide. Current clinical principles and best practice with emphasis on examining the technical aspects of surgery in centers with significant IAT experience are reviewed. METHODS: Literature search for studies discussing any technical aspect of pancreatectomy with intraportal IAT was included. RESULTS: Thirty-five papers were included; all were single-center case series. The indications, surgical approach to pancreatectomy with IAT, islet yield, static pancreas preservation prior to islet digestion, portal vein access, absolute islet infusion volumes, and portal venous pressure changes during transfusion evaluated. CONCLUSIONS: IAT is considered a "last resort" when alternative approaches have been exhausted. Pre-morbid histology and prior surgical drainage adversely influence islet yields and may influence the clinical decision to perform pancreatectomy and IAT. Following pancreas digestion, absolute numbers of islets recovered and smaller islet size predict rates of insulin independence following IAT. Islet volumes and portal venous pressure changes are important factors for the development of complications. Surgical access for IAT includes intra-operative, immediate or delayed infusion via an "exteriorized" vein, and radiological percutaneous approaches. Delayed infusion can be combined with pancreas preservation techniques prior to islet isolation.