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Zhang X, Xu W, Huang T, Huang J, Zhang C, Zhang Y, Xie X, Xu M. The value of clinical-ultrasonographic feature model to predict the severity of secondary hyperparathyroidism. Ren Fail 2022; 44:146-154. [PMID: 35164637 PMCID: PMC8856024 DOI: 10.1080/0886022x.2022.2027784] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Objectives To analyze conventional ultrasound (CUS) and contrast-enhanced ultrasound (CEUS) features in patients with secondary hyperparathyroidism (SHPT) and to evaluate the clinical-ultrasonographic feature based model for predicting the severity of SHPT. Methods From February 2016 to March 2021, a total of 59 patients (age 51.3 ± 11.7 years, seCr 797.8 ± 431.7 μmol/L, iPTH 1535.1 ± 1063.9 ng/L) with SHPT (including 181 parathyroid glands (PTGs)) without the history of intact parathyroid hormone (iPTH)-reducing drugs using were enrolled. The patients were divided into the mild SHPT group (mSHPT, iPTH <800 ng/L) and the severe SHPT group (sSHPT, iPTH ≥ 800 ng/L) according to the serum iPTH level. The clinical test data of patients were collected and CUS and CEUS examinations were performed for every patient. Multivariable logistic regression model according to clinical-ultrasonographic features was adopted to establish a nomogram. We performed K-fold cross-validation on this nomogram model and nomogram performance was determined by its discrimination, calibration, and clinical usefulness. Results There were 19 patients in the mSHPT group and 40 patients in the sSHPT group. Multivariable logistic regression indicated serum calcium, serum phosphorus and total volume of PTGs were independent predictors related with serum iPTH level. Even though CEUS score of wash-in and wash-out were showed related to severity of SHPT in univariate logistic regression analysis, they were not predictors of SHPT severity (p = 0.539, 0.474 respectively). The nomogram developed by clinical and ultrasonographic features showed good calibration and discrimination. The accuracy and the area under the curve (AUC), positive predictive value (PPV), negative predictive value (NPV) and accuracy of this model were 0.888, 92.5%, 63.2% and 83.1%, respectively. When applied to internal validation, the score revealed good discrimination with stratified fivefold cross-validation in the cohort (mean AUC = 0.833). Conclusions The clinical-ultrasonographic features model has good performance for predicting the severity of SHPT.
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Affiliation(s)
- Xiaoer Zhang
- Department of Medical Ultrasonics, The First Affiliated Hospital, Institute of Diagnostic and Interventional Ultrasound, Sun Yat-Sen University, Guangzhou, China
| | - Wenxin Xu
- Department of Medical Ultrasonics, The First Affiliated Hospital, Institute of Diagnostic and Interventional Ultrasound, Sun Yat-Sen University, Guangzhou, China
| | - Tongyi Huang
- Department of Medical Ultrasonics, The First Affiliated Hospital, Institute of Diagnostic and Interventional Ultrasound, Sun Yat-Sen University, Guangzhou, China
| | - Jingzhi Huang
- Department of Medical Ultrasonics, The First Affiliated Hospital, Institute of Diagnostic and Interventional Ultrasound, Sun Yat-Sen University, Guangzhou, China
| | - Chunyang Zhang
- Department of Medical Ultrasonics, The First Affiliated Hospital, Institute of Diagnostic and Interventional Ultrasound, Sun Yat-Sen University, Guangzhou, China
| | - Yutong Zhang
- Department of Medical Ultrasonics, The First Affiliated Hospital, Institute of Diagnostic and Interventional Ultrasound, Sun Yat-Sen University, Guangzhou, China
| | - Xiaoyan Xie
- Department of Medical Ultrasonics, The First Affiliated Hospital, Institute of Diagnostic and Interventional Ultrasound, Sun Yat-Sen University, Guangzhou, China
| | - Ming Xu
- Department of Medical Ultrasonics, The First Affiliated Hospital, Institute of Diagnostic and Interventional Ultrasound, Sun Yat-Sen University, Guangzhou, China
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Papadopoulou A, Bountouvi E, Karachaliou FE. The Molecular Basis of Calcium and Phosphorus Inherited Metabolic Disorders. Genes (Basel) 2021; 12:genes12050734. [PMID: 34068220 PMCID: PMC8153134 DOI: 10.3390/genes12050734] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Revised: 04/30/2021] [Accepted: 05/05/2021] [Indexed: 02/07/2023] Open
Abstract
Calcium (Ca) and Phosphorus (P) hold a leading part in many skeletal and extra-skeletal biological processes. Their tight normal range in serum mirrors their critical role in human well-being. The signalling “voyage” starts at Calcium Sensing Receptor (CaSR) localized on the surface of the parathyroid glands, which captures the “oscillations” of extracellular ionized Ca and transfers the signal downstream. Parathyroid hormone (PTH), Vitamin D, Fibroblast Growth Factor (FGF23) and other receptors or ion-transporters, work synergistically and establish a highly regulated signalling circuit between the bone, kidneys, and intestine to ensure the maintenance of Ca and P homeostasis. Any deviation from this well-orchestrated scheme may result in mild or severe pathologies expressed by biochemical and/or clinical features. Inherited disorders of Ca and P metabolism are rare. However, delayed diagnosis or misdiagnosis may cost patient’s quality of life or even life expectancy. Unravelling the thread of the molecular pathways involving Ca and P signaling, we can better understand the link between genetic alterations and biochemical and/or clinical phenotypes and help in diagnosis and early therapeutic intervention.
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Kohrt WM, Wolfe P, Sherk VD, Wherry SJ, Wellington T, Melanson EL, Swanson CM, Weaver CM, Boxer RS. Dermal Calcium Loss Is Not the Primary Determinant of Parathyroid Hormone Secretion during Exercise. Med Sci Sports Exerc 2020; 51:2117-2124. [PMID: 31009423 DOI: 10.1249/mss.0000000000002017] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
INTRODUCTION Exercise can cause a decrease in serum ionized calcium (iCa) concentration, which stimulates parathyroid hormone (PTH) secretion and activates bone resorption. We postulated that dermal Ca loss during cycling exercise is the major determinant of the serum iCa, PTH, and bone resorption (C-terminal telopeptide of type 1 collagen [CTX]) responses. METHODS To investigate this, women (n = 13) and men (n = 12) age 18 to 45 yr performed the same exercise bout under cool (18°C) and warm (26°C) conditions. Exercise was 60 min of cycling at ~75% of peak aerobic power. Sweat samples were obtained during exercise using a skin patch method, and blood samples were obtained before and during exercise and during 60 min of recovery. RESULTS Sweat volume and estimated sweat Ca loss were 50% higher for the warm condition than the cool condition. Despite this, there were no differences between thermal conditions in the changes (mean, 95% confidence interval [95% CI]) in iCa (cool, -0.07 mg·dL; 95% CI, -0.16 to 0.03); warm, -0.07 mg·dL; 95% CI, -0.20 to 0.05), PTH (cool, 34.4 pg·mL; 95% CI, 23.6-45.2; warm: 35.8 pg·mL; 95% CI, 22.4-49.1), or CTX (cool, 0.11 ng·mL; 95% CI, 0.08-0.13; warm, 0.15 ng·mL; 95% CI, 0.11-0.18). Adjusting for exercise-related shifts in plasma volume revealed a marked decline in vascular iCa content in the first 15 min of exercise (cool, -0.85 mg·dL; 95% CI, -1.01 to -0.68; warm, -0.85 mg·dL; 95% CI, -1.05 to -0.66), before substantial sweat Ca loss had occurred. CONCLUSIONS This indicates that dermal Ca loss was not the primary trigger for the increases in PTH and CTX during exercise. Further research is necessary to understand the causes and consequences of the disruption in Ca homeostasis during exercise and specifically the extravascular shift in iCa.
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Affiliation(s)
- Wendy M Kohrt
- Division of Geriatric Medicine, Department of Medicine, University of Colorado Denver, Aurora, CO.,Eastern Colorado VA Geriatric Research, Education, and Clinical Center, Aurora, CO
| | - Pamela Wolfe
- Department of Preventive Medicine and Biometrics, University of Colorado Denver, Aurora, CO
| | - Vanessa D Sherk
- Division of Endocrinology, Metabolism and Diabetes, Department of Medicine, University of Colorado Denver, Aurora, CO
| | - Sarah J Wherry
- Division of Geriatric Medicine, Department of Medicine, University of Colorado Denver, Aurora, CO.,Eastern Colorado VA Geriatric Research, Education, and Clinical Center, Aurora, CO
| | - Toby Wellington
- Division of Geriatric Medicine, Department of Medicine, University of Colorado Denver, Aurora, CO
| | - Edward L Melanson
- Division of Geriatric Medicine, Department of Medicine, University of Colorado Denver, Aurora, CO.,Eastern Colorado VA Geriatric Research, Education, and Clinical Center, Aurora, CO.,Division of Endocrinology, Metabolism and Diabetes, Department of Medicine, University of Colorado Denver, Aurora, CO
| | - Christine M Swanson
- Division of Endocrinology, Metabolism and Diabetes, Department of Medicine, University of Colorado Denver, Aurora, CO
| | - Connie M Weaver
- Department of Nutrition Science, Purdue University, West Lafayette, IN
| | - Rebecca S Boxer
- Division of Geriatric Medicine, Department of Medicine, University of Colorado Denver, Aurora, CO.,Eastern Colorado VA Geriatric Research, Education, and Clinical Center, Aurora, CO
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Schappacher-Tilp G, Cherif A, Fuertinger DH, Bushinsky D, Kotanko P. A mathematical model of parathyroid gland biology. Physiol Rep 2020; 7:e14045. [PMID: 30927339 PMCID: PMC6440916 DOI: 10.14814/phy2.14045] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2018] [Revised: 03/07/2019] [Accepted: 03/08/2019] [Indexed: 11/24/2022] Open
Abstract
Altered parathyroid gland biology in patients with chronic kidney disease (CKD) is a major contributor to chronic kidney disease-mineral bone disorder (CKD-MBD). This disorder is associated with an increased risk of bone disorders, vascular calcification, and cardiovascular events. Parathyroid hormone (PTH) secretion is primarily regulated by the ionized calcium concentration as well as the phosphate concentration in the extracellular fluid and vitamin D. The metabolic disturbances in patients with CKD lead to alterations in the parathyroid gland biology. A hallmark of CKD is secondary hyperparathyroidism, characterized by an increased production and release of PTH, reduced expression of calcium-sensing and vitamin D receptors on the surface of parathyroid cells, and hyperplasia and hypertrophy of these cells. These alterations happen on different timescales and influence each other, thereby triggering a cascade of negative and positive feedback loops in a highly complex manner. Due to this complexity, mathematical models are a useful tool to break down the patterns of the multidimensional cascade of processes enabling the detailed study of subsystems. Here, we introduce a comprehensive mathematical model that includes the major adaptive mechanisms governing the production, secretion, and degradation of PTH in patients with CKD on hemodialysis. Combined with models for medications targeting the parathyroid gland, it provides a ready-to-use tool to explore treatment strategies. While the model is of particular interest for use in hemodialysis patients with secondary hyperparathyroidism, it has the potential to be applicable to other clinical scenarios such as primary hyperparathyroidism or hypo- and hypercalcemia.
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Affiliation(s)
| | - Alhaji Cherif
- Renal Research Institute, New York City, New York.,School of Mathematical and Statistical Sciences, Arizona State University, Tempe, Arizona
| | - Doris H Fuertinger
- Global Research and Development, Fresenius Medical Care Germany, Bad Homburg, Germany
| | - David Bushinsky
- Division of Nephrology, Department of Medicine, University of Rochester School of Medicine, Rochester, New York
| | - Peter Kotanko
- Renal Research Institute, New York City, New York.,Icahn School of Medicine at Mount Sinai, New York City, New York
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Chen P, Olsson Gisleskog P, Perez-Ruixo JJ, Xiao J, Wilkins J, Narayanan A, Gibbs JP, Melhem M. Population Pharmacokinetics and Pharmacodynamics of the Calcimimetic Etelcalcetide in Chronic Kidney Disease and Secondary Hyperparathyroidism Receiving Hemodialysis. CPT-PHARMACOMETRICS & SYSTEMS PHARMACOLOGY 2016; 5:484-94. [PMID: 27639083 PMCID: PMC5036423 DOI: 10.1002/psp4.12106] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/25/2016] [Revised: 07/19/2016] [Accepted: 07/20/2016] [Indexed: 02/03/2023]
Abstract
Etelcalcetide is a novel calcimimetic in development for the treatment of secondary hyperparathyroidism (SHPT). A population pharmacokinetic/pharmacodynamic (PK/PD) model was developed relating etelcalcetide exposures to markers of efficacy (parathyroid hormone [PTH]) and safety (calcium) using data from three clinical studies. The semimechanistic model was developed that included allosteric activation pharmacology and understanding of calcium homeostasis. The temporal profiles for all biomarkers were well described by the model. The cooperativity constant was 4.94, confirming allosteric activation mechanism. Subjects with more severe disease (higher PTH baseline) were predicted to experience less pronounced reduction in PTH (percentage change from baseline), but more reduction in calcium (Ca; percentage change from baseline). There was no evidence that dose adjustment by any covariate was needed. Model‐based simulations provided quantitative support to several elements of dosing, such as starting dose, monitoring, and titration timing for registration trials.
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Affiliation(s)
- P Chen
- Department of Clinical Pharmacology, Modeling, and Simulation, Amgen Inc., Thousand Oaks, California, USA
| | | | - J J Perez-Ruixo
- Department of Clinical Pharmacology, Modeling, and Simulation, Amgen Inc., Thousand Oaks, California, USA.,Current address: Janssen Research & Development, Beerse, Belgium
| | - J Xiao
- Department of Clinical Pharmacology, Modeling, and Simulation, Amgen Inc., Thousand Oaks, California, USA.,Clovis Oncology Inc., San Francisco, California, USA
| | | | - A Narayanan
- Department of Clinical Pharmacology, Modeling, and Simulation, Amgen Inc., Thousand Oaks, California, USA
| | - J P Gibbs
- Department of Clinical Pharmacology, Modeling, and Simulation, Amgen Inc., Thousand Oaks, California, USA
| | - M Melhem
- Department of Clinical Pharmacology, Modeling, and Simulation, Amgen Inc., Thousand Oaks, California, USA.
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Veldhuis JD, Keenan DM, Pincus SM. Motivations and methods for analyzing pulsatile hormone secretion. Endocr Rev 2008; 29:823-64. [PMID: 18940916 PMCID: PMC2647703 DOI: 10.1210/er.2008-0005] [Citation(s) in RCA: 156] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/20/2008] [Accepted: 09/16/2008] [Indexed: 01/05/2023]
Abstract
Endocrine glands communicate with remote target cells via a mixture of continuous and intermittent signal exchange. Continuous signaling allows slowly varying control, whereas intermittency permits large rapid adjustments. The control systems that mediate such homeostatic corrections operate in a species-, gender-, age-, and context-selective fashion. Significant progress has been made in understanding mechanisms of adaptive interglandular signaling in vivo. Principal goals are to understand the physiological origins, significance, and mechanisms of pulsatile hormone secretion. Key analytical issues are: 1) to quantify the number, size, shape, and uniformity of pulses, nonpulsatile (basal) secretion, and elimination kinetics; 2) to evaluate regulation of the axis as a whole; and 3) to reconstruct dose-response interactions without disrupting hormone connections. This review will focus on the motivations driving and the methodologies used for such analyses.
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Affiliation(s)
- Johannes D Veldhuis
- Endocrine Research Unit, Department of Internal Medicine, Mayo Medical School, Mayo School of Graduate Medical Education, Center for Translational Science Activities, Mayo Clinic, Rochester, Minnesota 55905, USA.
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Rodriguez M, Nemeth E, Martin D. The calcium-sensing receptor: a key factor in the pathogenesis of secondary hyperparathyroidism. Am J Physiol Renal Physiol 2004; 288:F253-64. [PMID: 15507543 DOI: 10.1152/ajprenal.00302.2004] [Citation(s) in RCA: 113] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Serum calcium levels are regulated by the action of parathyroid hormone (PTH). Major drivers of PTH hypersecretion and parathyroid cell proliferation are the hypocalcemia and hyperphosphatemia that develop in chronic kidney disease patients with secondary hyperparathyroidism (SHPT) as a result of low calcitriol levels and decreased kidney function. Increased PTH production in response to systemic hypocalcemia is mediated by the calcium-sensing receptor (CaR). Furthermore, as SHPT progresses, reduced expression of CaRs and vitamin D receptors (VDRs) in hyperplastic parathyroid glands may limit the ability of calcium and calcitriol to regulate PTH secretion. Current treatment for SHPT includes the administration of vitamin D sterols and phosphate binders. Treatment with vitamin D is initially effective, but efficacy often wanes with further disease progression. The actions of vitamin D sterols are undermined by reduced expression of VDRs in the parathyroid gland. Furthermore, the calcemic and phosphatemic actions of vitamin D mean that it has the potential to exacerbate abnormal mineral metabolism, resulting in the formation of vascular calcifications. Effective new treatments for SHPT that have a positive impact on mineral metabolism are clearly needed. Recent research shows that drugs that selectively target the CaR, calcimimetics, have the potential to meet these requirements.
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Affiliation(s)
- Mariano Rodriguez
- Unidad de Investigación, Servicio de Nefrologia, Hospital Universitario Reina Sofía, Avd Menendez Pidal s/n, 14004 Cordoba, Spain.
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Chen RA, Goodman WG. Role of the calcium-sensing receptor in parathyroid gland physiology. Am J Physiol Renal Physiol 2004; 286:F1005-11. [PMID: 15130894 DOI: 10.1152/ajprenal.00013.2004] [Citation(s) in RCA: 94] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The calcium-sensing receptor (CaSR) represents the molecular mechanism by which parathyroid cells detect changes in blood ionized calcium concentration and modulate parathyroid hormone (PTH) secretion to maintain serum calcium levels within a narrow physiological range. Much has been learned in recent years about the diversity of signal transduction through the CaSR and the various factors that affect receptor expression. Beyond its classic role as a determinant of calcium-regulated PTH secretion, signaling through the CaSR also influences both gene transcription and cell proliferation in parathyroid cells. The CaSR thus serves a broad physiological role by integrating several distinct aspects of parathyroid gland function. The current review summarizes recent developments that enhance our understanding of the CaSR and its fundamental importance in parathyroid gland physiology.
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Affiliation(s)
- Randolph A Chen
- Div. of Nephrology, 7-155 Factor Bldg., UCLA Medical Ctr., 10833 Le Conte Ave., Los Angles, CA 90095, USA
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Olaizola I, Zingraff J, Heuguerot C, Fajardo L, Léger A, Lopez J, Acuña G, Petraglia A, Alvarez A, Caorsi H, Drüeke T, Ambrosoni P. [(99m)Tc]-sestamibi parathyroid scintigraphy in chronic haemodialysis patients: static and dynamic explorations. Nephrol Dial Transplant 2000; 15:1201-6. [PMID: 10910445 DOI: 10.1093/ndt/15.8.1201] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND The place of parathyroid gland imaging by [(99m)Tc](technetium)-sestamibi scintigraphy in uraemic patients with secondary hyperparathyroidism remains a matter of debate. The purpose of the present study was (i) to assess its value with respect to plasma intact parathyroid hormone (iPTH) levels and to surgical parathyroidectomy (PTx), and (ii) to explore the possibility of suppressing parathyroid [(99m)Tc]-sestamibi uptake by calcitriol. METHODS In a first cross-sectional, static study 52 chronic haemodialysis (HD) patients with plasma iPTH levels between 14 and 2791 pg/ml (normal, 10-65 pg/ml) had a [(99m)Tc]-sestamibi scan, and 21 of them underwent surgical PTx. In a second longitudinal, dynamic study 14 chronic HD patients with advanced secondary hyperparathyroidism received short-term calcitriol treatment in an attempt to suppress [(99m)Tc]-sestamibi imaging of parathyroid glands. Calcitriol was given intravenously for 2 weeks, 2 microg after each haemodialysis session. Scintigraphy was carried out before and at the end of this inhibition test. RESULTS [(99m)Tc]-Sestamibi scan led to imaging of one or more (maximum three) parathyroid glands in most, but not all, HD patients with plasma iPTH values >600 pg/ml. Based on surgical findings, overall sensitivity of [(99m)Tc]-sestamibi scan in correctly locating parathyroid glands was only 50%, whereas specificity was 100%. In contrast, its sensitivity was 100% in locating single glands in the subgroup of five patients with recurrent hyperparathyroidism. The calcitriol inhibition test showed suppression of [(99m)Tc]-sestamibi uptake by at least one parathyroid gland in eight patients (57%), with complete suppression in five of them (36%). Basal plasma iPTH or decrease of plasma iPTH in response to calcitriol was not predictive of suppressible [(99m)Tc]-sestamibi uptake in the individual case, although mean iPTH was markedly higher in patients with non-suppressible parathyroid glands. CONCLUSION Because of its relatively low sensitivity the [(99m)Tc]-sestamibi scan is of limited help in the exploration of uraemic patients with severe secondary hyperparathyroidism before a first surgical PTx. However, it is very useful in locating the remaining parathyroid gland(s) in case of reoperation. The novel calcitriol inhibition test of [(99m)Tc]-sestamibi uptake could help to better distinguish parathyroid glands with non-suppressible, autonomous activity from glands whose activity might be amenable to long-term suppression.
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Affiliation(s)
- I Olaizola
- Servicio de Nefrologia and Servicio de Medicina Nuclear, Hospital de Clinicas Manuel Quintela, Montevideo, Uruguay
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