Publications by authors named "Peaston R"

Introduction: 10% of corticotrophin (ACTH)-dependent Cushing's syndrome arises from secretion by extrapituitary tumours, with phaeochromocytoma implicated in a few cases. Ectopic secretion by phaeochromocytoma of corticotropin-releasing hormone (CRF), with secondary corticotroph hyperplasia, is even rarer, with only five cases in the literature hitherto. However, such cases may be classified as 'ectopic ACTH' due to incomplete verification.

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High altitude exposure normally leads to a marked natriuresis and diuresis. Acute mountain sickness is often associated with fluid retention, to which an elevated cortisol may contribute. Most investigators report a rise in resting cortisol with ascent, but little data exist regarding the cortisol response to a day trekking.

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Objectives: A number of associations have been shown between early growth and later sex hormone levels in women, but less is known about this relationship in men. This study investigated life-course predictors of sex hormones in men in the Newcastle Thousand Families birth cohort.

Methods: The Newcastle Thousand Families Study is a prospective study initiated in 1947.

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The aim of the study was to evaluate the effects of steroid administration under standardised conditions in a range of patients both normal and with adrenal pathologies and to review the impact on plasma catecholamines and metanephrines. Corticosteroid administration has been linked to the development of hypertensive crises in patients with phaeochromocytoma, however a mechanism for this is not fully understood. We aimed to add useful information about the effect of steroids on levels of these hormones under usual circumstances.

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Aims: To determine which factors predict outcomes in a group of patients with advanced heart failure, and in particular if NT-proBNP provides additional clinical and prognostic information to other haemodynamic and biochemical data.

Methods And Results: Ninety-one patients were studied who were being evaluated for heart transplantation, with 166 assessments. The patients had advanced heart failure as determined by median cardiac index of 2.

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Background: Plasma free metanephrines have proved a highly sensitive biochemical test for the diagnosis of pheochromocytoma. We have developed and validated a simple, LC-MS/MS method to determine plasma metanephrines and compared the diagnostic efficacy of the method with an enzyme immunoassay procedure in 151 patients, 38 with histologically confirmed pheochromocytoma.

Methods: Off-line solid phase extraction in a 96-well plate format was used to isolate metanephrines from 100-microL of plasma, followed by rapid separation with hydrophilic interaction chromatography.

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It has been suggested that bone health in adulthood is programmed by development in utero. Most previous investigations addressing this topic have focussed on bone mineral density or content, rather than other indicators of bone health, such as biochemical markers of bone turnover. This study investigated whether potential predictors, from different stages of life, influence bone resorption in men aged 49-51years in the Newcastle Thousand Families birth cohort.

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Background: the presence of osteoporosis in patients with hip and knee osteoarthritis (OA) has important implications for understanding disease progression and providing optimal surgical and medical management.

Objective: to determine the prevalence of osteoporosis among patients with osteoarthritis awaiting total knee arthroplasty or total hip arthroplasty aged between 65 and 80 years.

Design: cross-sectional observational study.

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Although smoking cessation is a prerequisite prior to listing for cardiac transplantation, some patients return to smoking after recovery. We have covertly assessed the smoking habits of our cardiac transplant recipients (with ethical approval) since 1993 by measuring urinary cotinine: a level of >500 ng/mL signifying continued tobacco use. We retrospectively analyzed survival, causes of death and the development of graft coronary artery disease (GCAD) with respect to the number of positive and negative cotinine levels.

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Phaeochromocytomas are rare tumours that require consideration among large numbers of patients with hypertension. If not diagnosed, the excessive secretion of catecholamines by these tumours can cause considerable morbidity and mortality. With a wide clinical variability in presentation, diagnosis can be difficult and invariably requires the biochemical confirmation of excessive catecholamine production by the tumour.

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Objective: Supra-renal fixation in endovascular aneurysm repair (SR-EVR) is used to improve the proximal seal of aortic stent grafts and appears to have minimal effect on serum creatinine. Serum cystatin C (CC) is a more sensitive marker of renal injury and, unlike creatinine, is unaffected by non-renal influence. The aim of this study was to assess the true renal effect of SR-EVR using this superior renal index.

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Intraarterial cooling (IAC) of non-heart-beating donors (NHBD) for renal donation requires a cheap, low-viscosity solution. HTK contains a high hydrogen ion buffer level that theoretically should reduce the observable acidosis associated with ongoing anaerobic metabolism. A retrospective comparison of all retrieved NHBD kidneys as well as of viability on the Organ Recovery Systems Lifeporter machine perfusion circuit was performed with respect to the preservation solution HTK or Marshall's HOC.

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Pheochromocytomas can have a highly variable presentation, making diagnosis challenging. To think of the tumor represents the crucial initial step, but establishing the diagnosis requires biochemical evidence of excessive catecholamine production and imaging studies to localize the source. Currently, however, there exist no generally agreed upon guidelines based on which tests and testing algorithms should be used to confirm and locate or exclude a suspected pheochromocytoma.

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Aim: To determine the prevalence of osteoporosis in a cohort of patients with Crohn's disease (CD) and to identify the relative significance of risk factors for osteoporosis.

Methods: Two hundred and fifty-eight unselected patients (92 M, 166 F) with CD were studied. Bone mineral density (BMD) was measured at the lumbar spine and hip by dual X-ray absorptiometry.

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Objective: Phaeochromocytoma crisis is a life-threatening emergency that may be undiagnosed because of its numerous, nonspecific manifestations. We analysed, retrospectively, the presentation, management and outcome of patients who were admitted to our institution with phaeochromocytoma crises over a 5-year period.

Results: Five patients (two males, three females; mean age 34.

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Purpose: Ischemia-reperfusion injury is gaining importance in transplantation as being responsible for allograft dysfunction. Ischemia occurs during kidney procurement, which is shortest in LDs, and prolonged in cadaveric HBDs and NHBDs.

Materials And Methods: Renal transplants from 17 LDs, 15 HBDs and 19 NHBDs were assessed during reperfusion for biochemical markers of ischemia-reperfusion injury and assessed clinically.

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Comparison of reperfusion injury in kidneys transplanted from LD, HBD or NHBD donors is presented in the paper. Central venous blood samples (taken during perioperative period) was assessed for free radicals, total antioxidant activity and various markers of tissue injury. There was demonstrable ischemia reperfusion injury occurring at the time of revascularization, which was particularly notable in kidneys transplanted from NHBD donors.

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Analysis of the low levels of catecholamines and metabolites in tissue and biological fluids has necessitated the use of highly sensitive analytical techniques. Earlier procedures utilizing radioenzymatic and immunological assays, gas chromatography or fluorimetry have generally been superseded by highly sensitive and selective chromatographic methods utilizing electrochemical or fluorimetric detection. The development of high-performance liquid chromatography (HPLC) methods for the measurement of plasma metadrenalines and the combination of HPLC with tandem mass spectrometry provides additional procedures with minimum interference from drugs and drug metabolites.

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Background: The growth in the prevalence of end-stage renal failure has been accompanied with a rise in the waiting list for renal transplantation, which has not been matched by an increase in the kidney donor pool. Non-heart-beating donors (NHBD) offer a potential source of kidneys that are not currently being significantly used. Cardiac arrest for a protracted period of time leads to in situ thrombosis, and, as a consequence, the discard rates for harvested kidneys is higher than brain-stem-dead donors.

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Background: Osteoporosis is a common complication of Crohn's disease.

Aim: To study the effect on the bone mineral density of a bisphosphonate (pamidronate) given intravenously, in combination with oral calcium and vitamin D supplements, compared with oral calcium and vitamin D supplements alone.

Methods: Seventy-four patients with Crohn's disease and low bone mineral density at the lumbar spine and/or hip were randomized to receive either a daily dose of 500 mg of calcium with 400 IU of vitamin D alone or in combination with four three-monthly infusions of 30 mg of intravenous pamidronate over the course of 12 months.

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Background: Renal transplantation in many units is limited by the availability of donor organs. Kidneys obtained from non-heart-beating donors (NHBD) represent an important resource, with the potential to substantially increase the available donor organ pool. Such kidneys are associated with increased warm ischaemic tissue injury which may be assessed by hypothermic machine perfusion.

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Background: With a universal shortage of donor organs, screening and selection of marginal kidneys from non-heart-beating donors (NHBDs) provides a valuable source for transplantation. Pre-transplant viability assessment is based on a combination of flow characteristics and assessment of ischaemic tissue injury during NHBD kidney machine perfusion by measurement of total glutathione S-transferase (GST) activity. Successful viability screening has facilitated 69 renal transplants from 60 NHBDs within our transplant centre since 1998, with a first-year graft survival of 90.

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We report what we believe to be the first case of a patient with multiple endocrine neoplasia type 2A (MEN 2A) and renal dysplasia associated with an RET 634 mutation. The proband presented at the age of 29 with medullary thyroid carcinoma (MTC), bilateral pheochromocytomas, and primary hyperparathyroidism. Screening of family members identified the syndrome in his father.

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