Publications by authors named "Stan H M Van Uum"

The characterization of sellar and suprasellar lesions is reliant on patient presentation, medical imaging, and hormone profiling. Prolactinomas are the most common type of functional pituitary adenomas, accounting for up to 57%. Importantly, prolactinomas can present without clear symptoms and with doubtful or even normal imaging.

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Background: To determine whether acromegaly is associated with increased extraocular muscle (EOM) size at time of presentation.

Methods: Patients with a new diagnosis of acromegaly in a single tertiary care clinic with a CT scan that adequately delineated the EOMs were included. Control subjects were age- and sex-matched patients with a new diagnosis of nonfunctioning pituitary adenoma.

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Background: Hair cortisol analysis is increasingly being appreciated and applied in both research and medicine, aiding endocrinologists with diagnosis.

Content: We provide an overview of hair cortisol research in general and an update on methodological considerations including the incorporation of cortisol into hair, hair growth rates, and sampling procedures, mincing vs. grinding of samples during preparation for extraction, various extraction protocols, and quantification techniques.

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Hypertension is one of the most common problems encountered in the primary care setting. Numerous secondary causes of hypertension exist and are potentially reversible. The ability to screen for such causes and manage them effectively may spare patients from prolonged medical therapy and hypertensive complications.

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We tested the hypothesis that sympathetic responses to baroreceptor unloading may be affected by circulating sex hormones. During lower body negative pressure at -30, -60, and -80 mmHg, muscle sympathetic nerve activity (MSNA), heart rate, and blood pressure were recorded in women who were taking (n = 8) or not taking (n = 9) hormonal contraceptives. All women were tested twice, once during the low-hormone phase (i.

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Introduction. Recombinant human thyroid stimulating hormone (rhTSH) is approved for preparation of thyroid remnant ablation with radioactive iodine (RAI) in low risk patients with well differentiated thyroid cancer (DTC). We studied the safety and efficacy of rhTSH preparation for RAI treatment of thyroid cancer patients with nodal metastatic disease.

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Background: Glucocorticoids as diagnostic or therapeutic agents have been reported to carry an increased risk of catecholaminergic crisis (CC) in patients with pheochromocytoma or paraganglioma (PPGL).

Methods: We searched literature databases using the following terms: pheochromocytoma, paraganglioma, adrenal incidentaloma, steroids, glucocorticoids, dexamethasone suppression test (DST), hypertensive crisis, cosyntropin and CRH. From all published case reports (1962-2013), we reviewed medical history, presenting symptoms, dose and route of steroid administration, location and size of adrenal mass, biochemical phenotype and outcome.

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This study aimed to examine the effects of sex (males vs. females) and sex hormones (menstrual cycle phases in women) on sympathetic responsiveness to severe chemoreflex activation in young, healthy individuals. Muscle sympathetic nerve activity (MSNA) was measured at baseline and during rebreathing followed by a maximal end-inspiratory apnea.

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Background: Hair cortisol analysis has been shown to be an effective measure of chronic stress. Cortisol is assumed to incorporate into hair via serum, sebum, and sweat sources; however, the extent to which sweat contributes to hair cortisol content is unknown.

Methods: Sweat and saliva samples were collected from 17 subjects after a period of intensive exercise and analyzed by salivary enzyme-linked immunosorbent assay (ELISA).

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Hormone fluctuations in women may influence muscle sympathetic nerve activity (MSNA) in a manner dependent on the severity of the sympathoexcitatory stimulus. This study examined MSNA patterns at rest and during chemoreflex stimulation in low- (LH) vs. high-hormone (HH) phases of contraceptive use in healthy young women (n = 7).

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Background: Levothyroxine (L-T4) absorption varies between individuals, and can be affected by various concomitantly administered drugs. Case reports have indicated an association between cotreatment with ciprofloxacin or rifampin and hypothyroidism in patients on a stable L-T4 dose.

Methods: The effects of two antibiotics on T4 absorption were prospectively assessed in a double-blind, randomized, crossover fashion.

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Context: Chromogranin A (CgA) is used as a generic tumor marker for neuroendocrine tumors. Proton pump inhibitors (PPI) are known to increase CgA, but it is not clear to what extent, and there is little information on how long PPI need to be discontinued before the effect of PPI has disappeared. Furthermore, is it not known whether this PPI effect is dependent on the CgA assay used.

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Opioid abuse has increased in the last decade, primarily as a result of increased access to prescription opioids. Physicians are also increasingly administering opioid analgesics for noncancer chronic pain. Thus, knowledge of the long-term consequences of opioid use/abuse has important implications for fully evaluating the clinical usefulness of opioid medications.

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Background: The measurement of testosterone (T) is essential for the diagnosis of male hypogonadism and for monitoring treatment. Samples need to be obtained at specific times in relation to the diurnal rhythm and therapeutic T injections. In this study, we explored the measurement of T in hair as an alternative method to assess gonadal status and long-term T exposure in men.

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What Is Already Known About This Subject: Insufficient drug adherence is an important reason for inadequate blood pressure control. Currently, methods that measure drug adherence objectively are lacking. Objective methods are needed to help improve blood pressure control and outcome in hypertensive patients.

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Purpose: Current methods for measuring long-term endogenous production of cortisol can be challenging due to the need to take multiple urine, saliva or serum samples. Hair grows approximately 1 centimeter per month, and hair analysis accurately reflects exposure to drug abuse and environmental toxins. Here we describe a new assay for measurement of cortisol in hair, and determined a reference range for non-obese subjects.

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Objective: Several methods have been described to measure adherence to prescribed drug therapy. However, most of these have been shown to be inaccurate. Bromide is an anion that is readily absorbed in the gut and has an elimination half-life of about 12 days.

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Hypersecretion of cortisol is associated with hypertension. In addition, an abnormal cortisol metabolism may play a role in the pathogenesis of hypertension. The 11beta-hydroxysteroid dehydrogenase (11beta-HSD) isozymes catalyze interconversion of cortisol and cortisone and play an important role in the regulation of the effects of cortisol.

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Background: Cortisol is known to increase blood pressure. One possible mechanism is the reported increase in renal vascular resistance (RVR). It is unknown whether this is due to a direct effect of cortisol on the kidneys.

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Objective: Deep vein thrombosis (DVT) is a multifactorial disease. Recently, inflammation has been suggested as a risk factor for DVT. The question is whether inflammation is a cause of venous thrombosis or rather a result of the thrombotic process.

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The 11 beta-hydroxysteroid dehydrogenase (11 beta-HSD) isoenzymes catalyse the interconversion of cortisol and cortisone. Type 1 11 beta-HSD mainly converts cortisone into active cortisol. Type 2 11 beta-HSD inactivates cortisol in mineralocorticoid target tissues, and its activity can be inhibited by glycyrrhetinic acid (GA).

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