Publications by authors named "Gurnell M"

Background: Arginine infusion stimulates copeptin secretion, a surrogate marker of arginine vasopressin (AVP), thereby serving as a diagnostic test in the differential diagnosis of suspected AVP deficiency (AVP-D). Yet, the precise mechanism underlying the stimulatory effect of arginine on the vasopressinergic system remains elusive. Arginine plays a significant role in the urea cycle and increases the production of urea.

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Objectives: Standardisation of medical examinations involves minimising assessor stereotyping and bias for a fair process. This study aimed to determine whether being a non-white candidate affected scoring by simulated patients, compared with a white candidate, at three different performance grades in the same history-taking station.

Design: Single-blinded, video-based, randomised study.

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Investigation and management of hypotonic polyuria is a common challenge in clinical endocrinology. The 3 main causes, recently renamed to arginine vasopressin deficiency (AVP-D, formerly central diabetes insipidus), arginine vasopressin resistance (AVP-R, formerly nephrogenic diabetes insipidus), and primary polydipsia (PP) require accurate diagnosis, as management differs for each. This new nomenclature more accurately reflects pathophysiology and has now been adopted by the Systemized Nomenclature of Medicine (SNOMED).

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Impaired sensitivity to thyroid hormones encompasses disorders with defective transport of hormones into cells, reduced hormone metabolism, and resistance to hormone action. Mediated by heritable single-gene defects, these rare conditions exhibit different patterns of discordant thyroid function associated with multisystem phenotypes. In this context, challenges include ruling out other causes of biochemical discordance, making a diagnosis using clinical features together with the identification of pathogenic variants in causal genes, and managing these rare disorders with a limited evidence base.

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Objective: To report our experience with F-fluoro-ethyl-tyrosine (FET) positron emission tomography-computed tomography (PET-CT) co-registered with magnetic resonance imaging (MRI) (FET-PET/MRI) in the care trajectory for persistent acromegaly.

Design: Prospective case series.

Patients: Ten patients with insufficiently controlled acromegaly referred to our team to evaluate surgical options.

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Purpose: Delivering fair and reliable summative assessments in medical education assumes examiner decision making is devoid of bias. We investigated whether candidate racial appearances influenced examiner ratings in undergraduate clinical exams.

Methods: We used an internet-based design.

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Background: [C]metomidate, a methyl ester analogue of etomidate, is used for positron emission tomography of adrenocortical cancer, and has been tested in recent clinical trials for lateralization in primary aldosteronism (PA). However, in PA, visualization as well as uptake quantification are hampered by the tracer's rather high non-specific liver uptake, and its overall clinical usefulness is also limited by the short 20-minute half-life of carbon-11. Therefore, we evaluated para-chloro-2-[F]fluoroethyl-etomidate, [F]CETO, a fluorine-18 (T=109.

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Background: L-[methyl-11C]-methionine-positron emission tomography (Met-PET) is a potentially important imaging adjunct in the diagnostic workup of pituitary adenomas, including somatotroph tumors. Met-PET can identify residual or occult disease and make definitive therapies accessible to a subgroup of patients who would otherwise require lifelong medical therapy. However, existing data on its use are still limited to small case series.

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Purpose: Dupilumab significantly reduced the requirement for systemic corticosteroids (SCS) in patients with severe chronic rhinosinusitis with nasal polyps (CRSwNP). Patients with CRSwNP and coexisting asthma typically have a higher disease burden and have more difficulty in managing disease. Here, we report an analysis of asthma outcomes and SCS use in patients with CRSwNP and coexisting asthma.

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Introduction: Regular cocaine use has been associated with hormonal dysfunction including hypogonadism, which can lead to fatigue, reduced stamina, sexual dysfunction, and impaired quality of life. However, cocaine's endocrine effects are largely under-reported in the scientific addiction literature and, in many cases, are not addressed within treatment services. The low profile of these adverse effects might be attributable to a lack of awareness and linkage with cocaine use, such that they are recognized only when an acute/emergency problem arises.

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Context: Although sleep disordered breathing (SDB) is well-recognised in acromegaly, most studies have reported heterogeneous, often heavily treated, groups and few have performed detailed sleep phenotyping at presentation.

Objective: To study SDB using the gold standard of polysomnography, in the largest group of newly-diagnosed, treatment-naïve patients with acromegaly.

Setting And Patients: 40 patients [22 males, 18 females; mean age 54 years (range 23-78)], were studied to: (i) establish the prevalence and severity of SDB (ii) assess the reliability of commonly employed screening tools [Epworth Sleepiness Scale (ESS) and overnight oxygen desaturation index (DI)] to detect SDB (iii) determine the extent to which sleep architecture is disrupted.

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Primary aldosteronism (PA) is the leading secondary cause of hypertension. Determining whether one (unilateral) or both (bilateral) adrenal glands are the source of PA in a patient remains challenging, and yet it is a critical step in the decision whether to recommend potentially curative surgery (adrenalectomy) or lifelong medical therapy (typically requiring multiple drugs). Recently, we have developed a fluorine-18 radiopharmaceutical [ F]CETO to permit greater access to PA molecular imaging.

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Measurement of free thyroid hormones (THs) and thyrotropin (TSH) using automated immunoassays is central to the diagnosis of thyroid dysfunction. Using illustrative cases, we describe a diagnostic approach to discordant thyroid function tests, focusing on entities causing elevated free thyroxine and/or free triiodothyronine measurements with nonsuppressed TSH levels. Different types of analytical interference (eg, abnormal thyroid hormone binding proteins, antibodies to iodothyronines or TSH, heterophile antibodies, biotin) or disorders (eg, resistance to thyroid hormone β or α, monocarboxylate transporter 8 or selenoprotein deficiency, TSH-secreting pituitary tumor) that can cause this biochemical pattern will be considered.

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Background: Distinguishing between arginine vasopressin (AVP) deficiency and primary polydipsia is challenging. Hypertonic saline-stimulated copeptin has been used to diagnose AVP deficiency with high accuracy but requires close sodium monitoring. Arginine-stimulated copeptin has shown similar diagnostic accuracy but with a simpler test protocol.

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Purpose: Heterogeneous reporting in baseline variables in patients undergoing transsphenoidal resection of pituitary adenoma precludes meaningful meta-analysis. We therefore examined trends in reported baseline variables, and degree of heterogeneity of reported variables in 30 years of literature.

Methods: A systematic review of PubMed and Embase was conducted on studies that reported outcomes for transsphenoidal surgery for pituitary adenoma 1990-2021.

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Background: Automated Item Generation (AIG) uses computer software to create multiple items from a single question model. There is currently a lack of data looking at whether item variants to a single question result in differences in student performance or human-derived standard setting. The purpose of this study was to use 50 Multiple Choice Questions (MCQs) as models to create four distinct tests which would be standard set and given to final year UK medical students, and then to compare the performance and standard setting data for each.

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This Consensus Statement from an international, multidisciplinary workshop sponsored by the Pituitary Society offers evidence-based graded consensus recommendations and key summary points for clinical practice on the diagnosis and management of prolactinomas. Epidemiology and pathogenesis, clinical presentation of disordered pituitary hormone secretion, assessment of hyperprolactinaemia and biochemical evaluation, optimal use of imaging strategies and disease-related complications are addressed. In-depth discussions present the latest evidence on treatment of prolactinoma, including efficacy, adverse effects and options for withdrawal of dopamine agonist therapy, as well as indications for surgery, preoperative medical therapy and radiation therapy.

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Primary aldosteronism (PA) is the most common cause of secondary hypertension and is associated with increased morbidity and mortality when compared with blood pressure-matched cases of primary hypertension. Current limitations in patient care stem from delayed recognition of the condition, limited access to key diagnostic procedures, and lack of a definitive therapy option for nonsurgical candidates. However, several recent advances have the potential to address these barriers to optimal care.

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Article Synopsis
  • The study aims to improve the understanding of non-functioning pituitary microadenomas (micro-NFPAs) and their natural progression to inform patient care.
  • Conducted across 23 endocrine departments in the UK, it analyzed clinical data from 459 patients over a median of 3.5 years, assessing tumor growth and hormonal changes.
  • Results indicate a low probability of tumor growth (7.8% at 3 years) and rare development of hypopituitarism, suggesting that follow-up MRIs every 3 years and less frequent hormonal checks are adequate for managing micro-NFPAs.
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Aldosterone-producing adenomas (APAs) are the commonest curable cause of hypertension. Most have gain-of-function somatic mutations of ion channels or transporters. Herein we report the discovery, replication and phenotype of mutations in the neuronal cell adhesion gene CADM1.

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Objective: Primary hyperparathyroidism is a common endocrine disorder, with 80% of all cases usually caused by one single hyperfunctioning parathyroid adenoma. Conventional imaging modalities for the diagnostic work-up of primary hyperparathyroidism (PHPT) include ultrasound of the neck, 99mTc-sestamibi scintigraphy, and four-dimensional computed tomography (4D-CT). However, the role of other imaging modalities, such as 11C-methionine PET/CT, in the care pathway for PHPT is currently unclear.

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