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Desrosiers M, Diamant Z, Castelnuovo P, Hellings P, Han J, Silver J, Gevaert P, Peters A. SUSTAINED CLINICAL BENEFITS IN PATIENTS WITH CHRONIC RHINOSINUSITIS WITH NASAL POLYPS 24 WEEKS POST-MEPOLIZUMAB TREATMENT. Ann Allergy Asthma Immunol 2022. [DOI: 10.1016/j.anai.2022.08.707] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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2
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Gianacopoulos E, Shu M, Silver J, Kadakia D, Eddib A. 8772 The Impact of Acute Urinary Retention Volume on Postoperative Urinary Dysfunction Following Robotic Sacrocolpopexy. J Minim Invasive Gynecol 2022. [DOI: 10.1016/j.jmig.2022.09.478] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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3
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Silver J, Strobel M, Gratie D, Guisinger A, Schmitt C, Ahmed W, Deb A. PATIENTS’ PERSPECTIVE ON THE BURDEN OF HYPEREOSINOPHILIC SYNDROME. Ann Allergy Asthma Immunol 2022. [DOI: 10.1016/j.anai.2022.08.998] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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4
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Silver J, Shu M, Gianacopoulos E, Olafuyi T, Eddib A. 8776 Perioperative Outcomes of Robotic Versus Open Midline Specimen Extraction Fascial Site Closure. J Minim Invasive Gynecol 2022. [DOI: 10.1016/j.jmig.2022.09.479] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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5
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Silver J, Steffens A, Chastek B, Deb A. REAL WORLD EFFECTIVENESS OF MEPOLIZUMAB IN PATIENTS WITH ALLERGIC AND NON-ALLERGIC ASTHMA. Ann Allergy Asthma Immunol 2022. [DOI: 10.1016/j.anai.2022.08.624] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Muhl EK, Armitage D, Silver J, Swerdfager T, Thorpe H. Indicators are Relational: Navigating Knowledge and Power in the Development and Implementation of Coastal-Marine Indicators. Environ Manage 2022; 70:448-463. [PMID: 35616655 DOI: 10.1007/s00267-022-01670-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Accepted: 05/15/2022] [Indexed: 06/15/2023]
Abstract
In many environment and resource management contexts (e.g., integrated coastal management, ecosystem-based fisheries management), indicator selection and development are perceived as a largely technical, bureaucratic, and scientific challenge. As such, choices about indicators and their application are often treated as external from everyday politics and dynamics of social power. Our aim here is to highlight the value of a relational perspective that weaves power and knowledge together in the context of indicator development and implementation. We highlight four critical dimensions of this relational perspective that may lead to better indicator process outcomes: 1) centering identity and positionality to reflect power differentials; 2) emphasizing the importance of indicator 'fit' and the politics of scale; 3) engaging rather than erasing social-ecological complexity; and 4) reflecting on social norms and relationships to foster adaptation and learning. These four dimensions are rarely considered in most indicator initiatives, including those that are more participatory in design and implementation. The dimensions we outline here emerge from the grounded experience of managers and practitioners, including indicator processes in which we are currently engaged, as well as a scoping review of the literature on indicators for coastal and marine governance and conservation specifically. However, the four dimensions and relational focus are relevant to a wide range of resource and environmental management contexts and provide a pathway to catalyze more effective indicator processes for decision-making and governance more generally.
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Affiliation(s)
- E K Muhl
- School of Environment, Resources and Sustainability, University of Waterloo, Waterloo, ON, Canada.
| | - D Armitage
- School of Environment, Resources and Sustainability, University of Waterloo, Waterloo, ON, Canada
| | - J Silver
- Department of Geography, Environment & Geomatics, University of Guelph, Guelph, ON, Canada
| | - T Swerdfager
- School of Environment, Resources and Sustainability, University of Waterloo, Waterloo, ON, Canada
| | - H Thorpe
- Parks Canada, Revelstoke, BC, Canada
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7
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Hassan A, Pollak YE, Kilav-Levin R, Silver J, London N, Nechama M, Ben-Dov IZ, Naveh-Many T. Kidney Failure Alters Parathyroid Pin1 Phosphorylation and Parathyroid Hormone mRNA-Binding Proteins, Leading to Secondary Hyperparathyroidism. J Am Soc Nephrol 2022; 33:1677-1693. [PMID: 35961788 PMCID: PMC9529182 DOI: 10.1681/asn.2022020197] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Accepted: 06/01/2022] [Indexed: 01/14/2023] Open
Abstract
BACKGROUND Secondary hyperparathyroidism (SHP) is a common complication of CKD that increases morbidity and mortality. In experimental SHP, increased parathyroid hormone (PTH) expression is due to enhanced PTH mRNA stability, mediated by changes in its interaction with stabilizing AUF1 and destabilizing KSRP. The isomerase Pin1 leads to KSRP dephosphorylation, but in SHP parathyroid Pin1 activity is decreased and hence phosphorylated KSRP fails to bind PTH mRNA, resulting in high PTH mRNA stability and levels. The up- and downstream mechanisms by which CKD stimulates the parathyroid glands remain elusive. METHODS Adenine-rich high-phosphate diets induced CKD in rats and mice. Parathyroid organ cultures and transfected cells were incubated with Pin1 inhibitors for their effect on PTH expression. Mass spectrometry was performed on both parathyroid and PTH mRNA pulled-down proteins. RESULTS CKD led to changes in rat parathyroid proteome and phosphoproteome profiles, including KSRP phosphorylation at Pin1 target sites. Furthermore, both acute and chronic kidney failure led to parathyroid-specific Pin1 Ser16 and Ser71 phosphorylation, which disrupts Pin1 activity. Pharmacologic Pin1 inhibition, which mimics the decreased Pin1 activity in SHP, increased PTH expression ex vivo in parathyroid glands in culture and in transfected cells through the PTH mRNA-protein interaction element and KSRP phosphorylation. CONCLUSIONS Kidney failure leads to loss of parathyroid Pin1 activity by inducing Pin1 phosphorylation. This predisposes parathyroids to increase PTH production through impaired PTH mRNA decay that is dependent on KSRP phosphorylation at Pin1-target motifs. Pin1 and KSRP phosphorylation and the Pin1-KSRP-PTH mRNA axis thus drive SHP.
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Affiliation(s)
- Alia Hassan
- Minerva Center for Bone and Mineral Research, Nephrology Services, Hadassah Hebrew University Medical Center and Faculty of Medicine, Jerusalem, Israel
| | - Yael E. Pollak
- Minerva Center for Bone and Mineral Research, Nephrology Services, Hadassah Hebrew University Medical Center and Faculty of Medicine, Jerusalem, Israel
| | - Rachel Kilav-Levin
- Minerva Center for Bone and Mineral Research, Nephrology Services, Hadassah Hebrew University Medical Center and Faculty of Medicine, Jerusalem, Israel
- School of Nursing, Jerusalem College of Technology, Faculty of Life and Health Sciences, Jerusalem, Israel
| | - Justin Silver
- Minerva Center for Bone and Mineral Research, Nephrology Services, Hadassah Hebrew University Medical Center and Faculty of Medicine, Jerusalem, Israel
| | - Nir London
- Department of Chemical and Structural Biology, Weizmann Institute of Science, Rehovot, Israel
| | - Morris Nechama
- Department of Pediatric Nephrology, Hadassah Hebrew University Medical Center and Faculty of Medicine, Jerusalem, Israel
- Wohl Institute for Translational Medicine, Hadassah Hebrew University Medical Center, Jerusalem, Israel
| | - Iddo Z. Ben-Dov
- Laboratory of Medical Transcriptomics, Nephrology Services, Hadassah Hebrew University Medical Center and Faculty of Medicine, Jerusalem, Israel
| | - Tally Naveh-Many
- Minerva Center for Bone and Mineral Research, Nephrology Services, Hadassah Hebrew University Medical Center and Faculty of Medicine, Jerusalem, Israel
- Wohl Institute for Translational Medicine, Hadassah Hebrew University Medical Center, Jerusalem, Israel
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8
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Hassen J, Silver J. Chemisorption Role of Clay Surfaces in the Synthesis of Porphyrins from its Raw Materials via Room Temperature Reactions. CHEM BIOCHEM ENG Q 2022. [DOI: 10.15255/cabeq.2021.2001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Affiliation(s)
| | - J. Silver
- Wolfson Centre for Material Processing, Brunel University
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9
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Hassan A, Khalaily N, Kilav-Levin R, Nechama M, Volovelsky O, Silver J, Naveh-Many T. Molecular Mechanisms of Parathyroid Disorders in Chronic Kidney Disease. Metabolites 2022; 12:metabo12020111. [PMID: 35208186 PMCID: PMC8878033 DOI: 10.3390/metabo12020111] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2021] [Revised: 01/17/2022] [Accepted: 01/20/2022] [Indexed: 01/27/2023] Open
Abstract
Secondary hyperparathyroidism (SHP) is a common complication of chronic kidney disease (CKD) that induces morbidity and mortality in patients. How CKD stimulates the parathyroid to increase parathyroid hormone (PTH) secretion, gene expression and cell proliferation remains an open question. In experimental SHP, the increased PTH gene expression is post-transcriptional and mediated by PTH mRNA–protein interactions that promote PTH mRNA stability. These interactions are orchestrated by the isomerase Pin1. Pin1 participates in conformational change-based regulation of target proteins, including mRNA-binding proteins. In SHP, Pin1 isomerase activity is decreased, and thus, the Pin1 target and PTH mRNA destabilizing protein KSRP fails to bind PTH mRNA, increasing PTH mRNA stability and levels. An additional level of post-transcriptional regulation is mediated by microRNA (miRNA). Mice with parathyroid-specific knockout of Dicer, which facilitates the final step in miRNA maturation, lack parathyroid miRNAs but have normal PTH and calcium levels. Surprisingly, these mice fail to increase serum PTH in response to hypocalcemia or uremia, indicating a role for miRNAs in parathyroid stimulation. SHP often leads to parathyroid hyperplasia. Reduced expressions of parathyroid regulating receptors, activation of transforming growth factor α-epidermal growth factor receptor, cyclooxygenase 2-prostaglandin E2 and mTOR signaling all contribute to the enhanced parathyroid cell proliferation. Inhibition of mTOR by rapamycin prevents and corrects the increased parathyroid cell proliferation of SHP. This review summarizes the current knowledge on the mechanisms that stimulate the parathyroid cell at multiple levels in SHP.
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Affiliation(s)
- Alia Hassan
- Minerva Center for Bone and Mineral Research, Nephrology Services, Hadassah—Hebrew University Medical Center, Jerusalem 91120, Israel; (A.H.); (N.K.); (R.K.-L.); (J.S.)
| | - Nareman Khalaily
- Minerva Center for Bone and Mineral Research, Nephrology Services, Hadassah—Hebrew University Medical Center, Jerusalem 91120, Israel; (A.H.); (N.K.); (R.K.-L.); (J.S.)
| | - Rachel Kilav-Levin
- Minerva Center for Bone and Mineral Research, Nephrology Services, Hadassah—Hebrew University Medical Center, Jerusalem 91120, Israel; (A.H.); (N.K.); (R.K.-L.); (J.S.)
- Nursing, Jerusalem College of Technology, Jerusalem 91160, Israel
| | - Morris Nechama
- Pediatric Nephrology, Hadassah—Hebrew University Medical Center, Jerusalem 91120, Israel; (M.N.); (O.V.)
- The Wohl Institute for Translational Medicine, Hadassah—Hebrew University Medical Center, Jerusalem 91120, Israel
| | - Oded Volovelsky
- Pediatric Nephrology, Hadassah—Hebrew University Medical Center, Jerusalem 91120, Israel; (M.N.); (O.V.)
- The Wohl Institute for Translational Medicine, Hadassah—Hebrew University Medical Center, Jerusalem 91120, Israel
| | - Justin Silver
- Minerva Center for Bone and Mineral Research, Nephrology Services, Hadassah—Hebrew University Medical Center, Jerusalem 91120, Israel; (A.H.); (N.K.); (R.K.-L.); (J.S.)
| | - Tally Naveh-Many
- Minerva Center for Bone and Mineral Research, Nephrology Services, Hadassah—Hebrew University Medical Center, Jerusalem 91120, Israel; (A.H.); (N.K.); (R.K.-L.); (J.S.)
- The Wohl Institute for Translational Medicine, Hadassah—Hebrew University Medical Center, Jerusalem 91120, Israel
- Correspondence:
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10
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Wellington IJ, Stelzer JW, Silver J, Solovyova O. Operative efficiency: comparison of methods to optimize the use of chlorhexidine gluconate applicators. J Hosp Infect 2021; 118:59-62. [PMID: 34637851 DOI: 10.1016/j.jhin.2021.10.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Revised: 10/04/2021] [Accepted: 10/05/2021] [Indexed: 11/27/2022]
Abstract
BACKGROUND With the high costs of operating room time, minimizing potential causes of time waste is financially beneficial to surgeons and hospitals. The time needed to activate a chlorhexidine gluconate surgical solution applicator presents an opportunity for optimization. Many techniques are employed to expedite the process, but there have been no studies comparing these techniques. AIM To determine the most efficient method for utilizing a chlorhexidine gluconate surgical prep applicator. METHODS Six techniques were tested to determine which caused the sponge of a Chloraprep™ applicator to become saturated quickest. These were a single squeeze (control), up-and-down shaking, side-to-side shaking, pressing the sponge on a surface (dab), pressing with cotton swabs (poke), and continuously squeezing the lever of the applicator. The time between the internal glass breaking in the applicator to the time of sponge saturation with solution was measured for each technique. Times were then compared to determine which technique best expedited the process. FINDINGS The side-to-side shake, up-and-down shake, and 'dab' techniques were each significantly faster than the control group. Side-to-side shaking had the fastest time to sponge saturation on average. The average difference in time to saturation between the side-to-side shake technique and the 'poke' technique may be as much as 27.5 s. CONCLUSIONS Utilization of the side-to-side shake technique, as well as the up-and-down shake and 'dab' techniques, significantly expedite the time it takes to use a chlorhexidine gluconate applicator. The time savings from employing these techniques could result in significant financial benefits.
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Affiliation(s)
- I J Wellington
- University of Connecticut Department of Orthopaedics, University of Connecticut Health Center, Farmington, CT, USA.
| | - J W Stelzer
- University of Connecticut Department of Orthopaedics, University of Connecticut Health Center, Farmington, CT, USA
| | - J Silver
- University of Connecticut Department of Orthopaedics, University of Connecticut Health Center, Farmington, CT, USA
| | - O Solovyova
- University of Connecticut Department of Orthopaedics, University of Connecticut Health Center, Farmington, CT, USA
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11
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Naveh-Many T, Silver J. Transcription factors that determine parathyroid development power PTH expression. Kidney Int 2020; 93:7-9. [PMID: 29291826 DOI: 10.1016/j.kint.2017.08.026] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2017] [Revised: 08/08/2017] [Accepted: 08/09/2017] [Indexed: 01/08/2023]
Abstract
Studies in patients with hypoparathyroidism and knockout mouse models have revealed key transcriptional cascades central for parathyroid organogenesis. Among the transcription factors essential for parathyroid development, Gata3, GCM2, and MafB, are expressed in the developing parathyroids as well as postnatally, implying that they also regulate parathyroid-specific gene expression and function in the adult. PTH gene expression is determined by transcriptional and posttranscriptional mechanisms. The study by Morito et al. demonstrates that MafB contributes to the stimulation of the parathyroid by hypocalcemia and uremia.
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Affiliation(s)
- Tally Naveh-Many
- Hadassah Hebrew University Medical Center, Jerusalem, Ein Karem, Israel.
| | - Justin Silver
- Hadassah Hebrew University Medical Center, Jerusalem, Ein Karem, Israel
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12
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Kilav-Levin R, Hassan A, Nechama M, Shilo V, Silver J, Ben-Dov IZ, Naveh-Many T. Post-transcriptional mechanisms regulating parathyroid hormone gene expression in secondary hyperparathyroidism. FEBS J 2020; 287:2903-2913. [PMID: 32191397 DOI: 10.1111/febs.15300] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2019] [Revised: 12/10/2019] [Accepted: 03/17/2020] [Indexed: 12/11/2022]
Abstract
Parathyroid hormone (PTH) regulates serum calcium levels and bone strength. Secondary hyperparathyroidism (SHP) is a common complication of chronic kidney disease (CKD) that correlates with morbidity and mortality. In experimental SHP, the increased PTH gene expression is due to increased PTH mRNA stability and is mediated by protein-PTH mRNA interactions. Adenosine-uridine-rich binding factor 1 (AUF1) stabilizes and K-homology splicing regulatory protein (KSRP) destabilizes PTH mRNA. The peptidyl-prolyl cis/trans isomerase Pin1 acts on target proteins, including mRNA-binding proteins. Pin1 leads to KSRP dephosphorylation, but in SHP, parathyroid Pin1 activity is decreased and phosphorylated KSRP fails to bind PTH mRNA, leading to increased PTH mRNA stability and levels. A further level of post-transcriptional regulation occurs through microRNA (miRNA). Dicer mediates the final step of miRNA maturation. Parathyroid-specific Dicer knockout mice that lack miRNAs in the parathyroid develop normally. Surprisingly, these mice fail to increase serum PTH in response to both hypocalcemia and CKD, indicating that parathyroid Dicer and miRNAs are essential for stimulation of the parathyroid. Human and rodent parathyroids share similar miRNA profiles that are altered in hyperparathyroidism. The evolutionary conservation of abundant miRNAs and their regulation in hyperparathyroidism indicate their significance in parathyroid physiology and pathophysiology. let-7 and miR-148 antagonism modifies PTH secretion in vivo and in vitro, suggesting roles for specific miRNAs in parathyroid function. This review summarizes the current knowledge on the post-transcriptional mechanisms of PTH gene expression in SHP and the central contribution of miRNAs to the high serum PTH levels of both primary hyperparathyroidism and SHP.
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Affiliation(s)
- Rachel Kilav-Levin
- Minerva Center for Bone and Mineral Research, Nephrology Services, Hadassah - Hebrew University Medical Center, Jerusalem, Israel.,Nursing, Jerusalem College of Technology, Israel
| | - Alia Hassan
- Minerva Center for Bone and Mineral Research, Nephrology Services, Hadassah - Hebrew University Medical Center, Jerusalem, Israel
| | - Morris Nechama
- Minerva Center for Bone and Mineral Research, Nephrology Services, Hadassah - Hebrew University Medical Center, Jerusalem, Israel.,Pediatric Nephrology, Hadassah - Hebrew University Medical Center, Jerusalem, Israel.,The Wohl Institute for Translational Medicine, Hadassah - Hebrew University Medical Center, Jerusalem, Israel
| | - Vitali Shilo
- Minerva Center for Bone and Mineral Research, Nephrology Services, Hadassah - Hebrew University Medical Center, Jerusalem, Israel
| | - Justin Silver
- Minerva Center for Bone and Mineral Research, Nephrology Services, Hadassah - Hebrew University Medical Center, Jerusalem, Israel
| | - Iddo Z Ben-Dov
- Laboratory of Medical Transcriptomics, Nephrology Services, Hadassah - Hebrew University Medical Center, Jerusalem, Israel
| | - Tally Naveh-Many
- Minerva Center for Bone and Mineral Research, Nephrology Services, Hadassah - Hebrew University Medical Center, Jerusalem, Israel.,The Wohl Institute for Translational Medicine, Hadassah - Hebrew University Medical Center, Jerusalem, Israel
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Silver J, Llanos J, Mayer B, Prazma C, Albers F. P218 GREATER EFFICACY OF MEPOLIZUMAB IN SEVERE EOSINOPHILIC ASTHMA WITH HIGH BASELINE BLOOD EOSINOPHIL COUNTS. Ann Allergy Asthma Immunol 2019. [DOI: 10.1016/j.anai.2019.08.284] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Hoss S, Habib M, Silver J, Chan R, Rakowski H, Adler A. YIELD OF GENETIC TESTING FOR HYPERTROPHIC CARDIOMYOPATHY ACCORDING TO CONTEMPORARY VARIANT INTERPRETATION GUIDELINES: RESULTS FROM A LARGE CANADIAN REFERRAL CENTRE. Can J Cardiol 2019. [DOI: 10.1016/j.cjca.2019.07.432] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
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den Engelsen D, Fern GR, Ireland TG, Hudry D, Abeykoon AMM, Nykypanchuk D, Dickerson JH, Silver J. Ultrathin Y 2O 3:Eu 3+nanodiscs: spectroscopic investigations and evidence for reduced concentration quenching. Nanotechnology 2018; 29:455703. [PMID: 30136652 DOI: 10.1088/1361-6528/aadc83] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Here, we report the synthesis and spectral properties of ultrathin nanodiscs (NDs) of Y2O3:Eu3+. It was found that the NDs of Y2O3:Eu3+ with a thickness of about 1 nm can be fabricated in a reproducible, facile and self-assembling process, which does not depend on the Eu3+ concentration. The thickness and morphology of these NDs were determined with small angle x-ray scattering and transmission electron microscopy. We found that the crystal field in these nanoparticles deviates from both the cubic and monoclinic characteristics, albeit the shape of the 5D0 → 7F J (J = 0, 1, 2) transitions shows some similarity with the transitions in the monoclinic material. The Raman spectra of the non-annealed NDs manifest various vibration modes of the oleic acid molecules, which are used to stabilise the NDs. The annealed NDs show two very weak Raman lines, which may be assigned to vibrational modes of Y2O3 NDs. The concentration quenching of the Eu3+ luminescence of the NDs before annealing is largely suppressed and might be explained in terms of a reduction of the phonon density of states.
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Affiliation(s)
- D den Engelsen
- Centre for Phosphor and Display Materials, Wolfson Centre for Materials Processing, Brunel University London, Uxbridge, Middlesex, UB8 3PH, United Kingdom
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Edwards RL, Silver J, Rickles FR. Human Tumor Procoagulants: Registry of the Subcommittee on Haemostasis and Malignancy of the Scientific and Standardization Committee, International Society on Thrombosis and Haemostasis. Thromb Haemost 2018. [DOI: 10.1055/s-0038-1651580] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Affiliation(s)
- R L Edwards
- The University of Connecticut School of Medicine and the American Red Cross Connecticut Region Blood Services, Farmington, CT, USA, and the Department of Veterans Affairs Medical Center, Newington, CT, USA
| | - J Silver
- The University of Connecticut School of Medicine and the American Red Cross Connecticut Region Blood Services, Farmington, CT, USA, and the Department of Veterans Affairs Medical Center, Newington, CT, USA
| | - F R Rickles
- The University of Connecticut School of Medicine and the American Red Cross Connecticut Region Blood Services, Farmington, CT, USA, and the Department of Veterans Affairs Medical Center, Newington, CT, USA
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17
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Durlacher-Betzer K, Hassan A, Levi R, Axelrod J, Silver J, Naveh-Many T. Interleukin-6 contributes to the increase in fibroblast growth factor 23 expression in acute and chronic kidney disease. Kidney Int 2018; 94:315-325. [PMID: 29861060 DOI: 10.1016/j.kint.2018.02.026] [Citation(s) in RCA: 99] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2017] [Revised: 02/18/2018] [Accepted: 02/22/2018] [Indexed: 12/13/2022]
Abstract
The high serum fibroblast growth factor 23 (FGF23) levels in patients with acute kidney injury (AKI) and chronic kidney disease (CKD) are associated with increased morbidity and mortality. Mice with folic acid-induced AKI had an increase in bone FGF23 mRNA expression together with an increase in serum FGF23 and several circulating cytokines including interleukin-6 (IL-6). Dexamethasone partially prevented the increase in IL-6 and FGF23 in the AKI mice. IL-6 knock-out mice fed an adenine diet to induce CKD failed to increase bone FGF23 mRNA and had a muted increase in serum FGF23 levels, compared with the increases in wild-type mice with CKD. Therefore, IL-6 contributes to the increase in FGF23 observed in CKD. Hydrodynamic tail injection of IL-6/soluble IL-6 receptor (sIL-6R) fusion protein hyper IL-6 (HIL-6) plasmid increased serum FGF23 levels. Circulating sIL-6R levels were increased in both CKD and AKI mice, suggesting that IL-6 increases FGF23 through sIL-6R-mediated trans-signaling. Renal IL-6 mRNA expression was increased in mice with either AKI or CKD, suggesting the kidney is the source for the increased serum IL-6 levels in the uremic state. HIL-6 also increased FGF23 mRNA in calvaria organ cultures and osteoblast-like UMR106 cells in culture, demonstrating a direct effect of IL-6 on FGF23 expression. HIL-6 increased FGF23 promoter activity through STAT3 phosphorylation and its evolutionarily conserved element in the FGF23 promoter. Thus, IL-6 increases FGF23 transcription and contributes to the high levels of serum FGF23 in both acute and chronic kidney disease.
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MESH Headings
- Acute Kidney Injury/blood
- Acute Kidney Injury/chemically induced
- Acute Kidney Injury/drug therapy
- Acute Kidney Injury/immunology
- Adenine/toxicity
- Animals
- Bone and Bones/pathology
- Dexamethasone/therapeutic use
- Disease Models, Animal
- Fibroblast Growth Factor-23
- Fibroblast Growth Factors/blood
- Fibroblast Growth Factors/genetics
- Fibroblast Growth Factors/immunology
- Fibroblast Growth Factors/metabolism
- Folic Acid/toxicity
- Glucocorticoids/therapeutic use
- Humans
- Interleukin-6/blood
- Interleukin-6/genetics
- Interleukin-6/immunology
- Interleukin-6/metabolism
- Kidney/immunology
- Kidney/pathology
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Phosphorylation/immunology
- Promoter Regions, Genetic/genetics
- RNA, Messenger/metabolism
- Receptors, Interleukin-6/genetics
- Recombinant Fusion Proteins/administration & dosage
- Recombinant Fusion Proteins/genetics
- Renal Insufficiency, Chronic/blood
- Renal Insufficiency, Chronic/chemically induced
- Renal Insufficiency, Chronic/drug therapy
- Renal Insufficiency, Chronic/immunology
- STAT3 Transcription Factor/metabolism
- Transcription, Genetic/immunology
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Affiliation(s)
- Karina Durlacher-Betzer
- Minerva Center for Calcium and Bone Metabolism, Nephrology Services, Hadassah Hebrew University Medical Center, Jerusalem, Israel
| | - Alia Hassan
- Minerva Center for Calcium and Bone Metabolism, Nephrology Services, Hadassah Hebrew University Medical Center, Jerusalem, Israel
| | - Ronen Levi
- Minerva Center for Calcium and Bone Metabolism, Nephrology Services, Hadassah Hebrew University Medical Center, Jerusalem, Israel
| | - Jonathan Axelrod
- Goldyn Savad Institute of Gene Therapy, Hadassah Hebrew University Medical Center, Jerusalem, Israel
| | - Justin Silver
- Minerva Center for Calcium and Bone Metabolism, Nephrology Services, Hadassah Hebrew University Medical Center, Jerusalem, Israel
| | - Tally Naveh-Many
- Minerva Center for Calcium and Bone Metabolism, Nephrology Services, Hadassah Hebrew University Medical Center, Jerusalem, Israel.
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Behbehani S, Polesello S, Hasson J, Silver J, Son WY, Dahan M. The Effect of Intramural Myomas Without an Intracavity Component on In Vitro Fertilization Outcomes in Single Fresh Blastocyst Transfer Cycles. J Minim Invasive Gynecol 2018. [PMID: 29530836 DOI: 10.1016/j.jmig.2018.03.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
STUDY OBJECTIVE To assess clinical pregnancy rate (CPR) and live birth rate (LBR) in the presence of non-cavity-deforming intramural myomas in single fresh blastocyst transfer cycles. DESIGN Retrospective cohort study (Canadian Task Force classification II-2). SETTING Academic fertility center. PATIENTS A total of 929 fresh single blastocyst transfer cycles were included, 94 with only non-cavity-distorting intramural myomas and 764 without myomas. Cleavage embryo transfers were excluded to reduce bias based on embryo quality. INTERVENTIONS None. MEASUREMENTS AND MAIN RESULTS CPR and LBR were assessed. There were no differences noted in gravidity, parity, or body mass index between patients with myomas and those without myomas. Women with myomas required higher doses of gonadotropins (mean, 2653 ± 404 IU vs 2350 ± 1368 IU; p = .04) than women without myomas. However, the total number of mature oocytes collected and the total number of blastocysts created were similar. CPR (47% vs 32%; p = .005) and LBR (37.8% vs 25.5%; p = .02) were lower in patients who had intramural myomas compared with those without myomas. CPR and LBR were significantly reduced in the presence of even 1 myoma (odds ratio [OR], 0.53; 95% confidence interval [CI], 0.33-0.83 and OR, 0.56; 95% CI, 0.35-0.92, respectively). In patients with myomas >1.5 cm, LBR was also significantly reduced, even after adjusting for age, smoking, quality of embryo transferred, antral follicle count, and dose of gonadotropins (OR, 0.53; 95% CI, 0.29-0.97). This LBR finding was not significant if all myomas were included (including those <1.5 cm in diameter), but CPR was still significantly reduced. CONCLUSION Relatively small (>1.5 cm) non-cavity-distorting intramural myomas negatively affect CPR and LBR in in vitro fertilization cycles, even in the presence of only 1 myoma.
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Affiliation(s)
| | | | - Joseph Hasson
- McGill University Health Center, Montreal, Quebec, Canada
| | - Justin Silver
- McGill University Health Center, Montreal, Quebec, Canada
| | - Weon-Young Son
- McGill University Health Center, Montreal, Quebec, Canada
| | - Michael Dahan
- McGill University Health Center, Montreal, Quebec, Canada
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Kelly C, Melville L, Silver J, Guo U, Briggs W. 245 No Pain, No Gain? Parental Valuation of Watchful Waiting Versus Catheterization in the Diagnosis of Urinary Tract Infection in Very Young Children. Ann Emerg Med 2017. [DOI: 10.1016/j.annemergmed.2017.07.467] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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20
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Weiner MF, Silver J. St Hugh's Military Hospital (Head Injuries), Oxford 1940-1945. J R Coll Physicians Edinb 2017; 47:183-189. [PMID: 28675196 DOI: 10.4997/jrcpe.2017.219] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Despite being open for only five years, St Hugh's Military Hospital (Head Injuries) has a seminal place in the history of neurology, neurosurgery and rehabilitation medicine. At its peak, during the Normandy campaign of 1944, it provided 430 beds for the treatment of service personnel. Between 1940 and 1945, 13,000 patients were referred to St Hugh's providing a unique opportunity for ground-breaking research into the management of head injuries. The doctors at St Hugh's collaborated with research scientists at Oxford University in many areas of fundamental research including the treatment of infection, the mechanics of brain injury, brain surgery, neuropsychiatry and rehabilitation, and the use of electroencephalograms. This paper documents these scientific advances and considers their influence on the practice of neurology and neurosurgery in the UK.
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Affiliation(s)
- M F Weiner
- JR Silver, Akeman Business Park, 81-82 Akeman Street, Tring HP23 6AF, UK.
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21
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Abstract
Dental disease in the form of caries and abscesses has been known since antiquity. Before the advent of anaesthesia, operations upon the mouth were painful. The introduction of general anaesthesia in the form of ether and chloroform seemed to provide a solution, but there was an unacceptable level of mortality. James Arnott introduced local anaesthesia by means of freezing with ice, which he considered safer. He waged a long campaign and his method received recognition and was used in France and the USA. His method stimulated the development of pharmacological anaesthesia.
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Affiliation(s)
- K Silver
- Cavendish House Dental practice, 240 East End Road London, N2 8AX
| | - J Silver
- Spinal Injuries, Fellow of Institute of Sports Medicine, Akeman Business Park, 81-82 Akeman Street, Tring, Hertfordshire, HP23 6AF
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Block GA, Bushinsky DA, Cunningham J, Drueke TB, Ketteler M, Kewalramani R, Martin KJ, Mix TC, Moe SM, Patel UD, Silver J, Spiegel DM, Sterling L, Walsh L, Chertow GM. Effect of Etelcalcetide vs Placebo on Serum Parathyroid Hormone in Patients Receiving Hemodialysis With Secondary Hyperparathyroidism: Two Randomized Clinical Trials. JAMA 2017; 317:146-155. [PMID: 28097355 DOI: 10.1001/jama.2016.19456] [Citation(s) in RCA: 91] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
IMPORTANCE Secondary hyperparathyroidism contributes to extraskeletal complications in chronic kidney disease. OBJECTIVE To evaluate the effect of the intravenous calcimimetic etelcalcetide on serum parathyroid hormone (PTH) concentrations in patients receiving hemodialysis. DESIGN, SETTING, AND PARTICIPANTS Two parallel, phase 3, randomized, placebo-controlled treatment trials were conducted in 1023 patients receiving hemodialysis with moderate to severe secondary hyperparathyroidism. Trial A was conducted in 508 patients at 111 sites in the United States, Canada, Europe, Israel, Russia, and Australia from March 12, 2013, to June 12, 2014; trial B was conducted in 515 patients at 97 sites in the same countries from March 12, 2013, to May 12, 2014. INTERVENTIONS Intravenous administration of etelcalcetide (n = 503) or placebo (n = 513) after each hemodialysis session for 26 weeks. MAIN OUTCOMES AND MEASURES The primary efficacy end point was the proportion of patients achieving greater than 30% reduction from baseline in mean PTH during weeks 20-27. A secondary efficacy end point was the proportion of patients achieving mean PTH of 300 pg/mL or lower. RESULTS The mean age of the 1023 patients was 58.2 (SD, 14.4) years and 60.4% were men. Mean PTH concentrations at baseline and during weeks 20-27 were 849 and 384 pg/mL vs 820 and 897 pg/mL in the etelcalcetide and placebo groups, respectively, in trial A; corresponding values were 845 and 363 pg/mL vs 852 and 960 pg/mL in trial B. Patients randomized to etelcalcetide were significantly more likely to achieve the primary efficacy end point: in trial A, 188 of 254 (74.0%) vs 21 of 254 (8.3%; P < .001), for a difference in proportions of 65.7% (95% CI, 59.4%-72.1%) and in trial B, 192 of 255 (75.3%) vs 25 of 260 (9.6%; P < .001), for a difference in proportions of 65.7% (95% CI, 59.3%-72.1%). Patients randomized to etelcalcetide were significantly more likely to achieve a PTH level of 300 pg/mL or lower: in trial A, 126 of 254 (49.6%) vs 13 of 254 (5.1%; P < .001), for a difference in proportions of 44.5% (95% CI, 37.8%-51.2%) and in trial B, 136 of 255 (53.3%) vs 12 of 260 (4.6%; P < .001), for a difference in proportions of 48.7% (95% CI, 42.1%-55.4%). In trials A and B, respectively, patients receiving etelcalcetide had more muscle spasms (12.0% and 11.1% vs 7.1% and 6.2% with placebo), nausea (12.4% and 9.1% vs 5.1% and 7.3%), and vomiting (10.4% and 7.5% vs 7.1% and 3.1%). CONCLUSIONS AND RELEVANCE Among patients receiving hemodialysis with moderate to severe secondary hyperparathyroidism, use of etelcalcetide compared with placebo resulted in greater reduction in serum PTH over 26 weeks. Further studies are needed to assess clinical outcomes as well as longer-term efficacy and safety. TRIAL REGISTRATION clinicaltrials.gov Identifiers: NCT01788046.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | - Justin Silver
- Hadassah Hebrew University Medical Center, Jerusalem, Israel
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Block GA, Bushinsky DA, Cheng S, Cunningham J, Dehmel B, Drueke TB, Ketteler M, Kewalramani R, Martin KJ, Moe SM, Patel UD, Silver J, Sun Y, Wang H, Chertow GM. Effect of Etelcalcetide vs Cinacalcet on Serum Parathyroid Hormone in Patients Receiving Hemodialysis With Secondary Hyperparathyroidism: A Randomized Clinical Trial. JAMA 2017; 317:156-164. [PMID: 28097356 DOI: 10.1001/jama.2016.19468] [Citation(s) in RCA: 138] [Impact Index Per Article: 19.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
IMPORTANCE Secondary hyperparathyroidism contributes to extraskeletal calcification and is associated with all-cause and cardiovascular mortality. Control is suboptimal in the majority of patients receiving hemodialysis. An intravenously (IV) administered calcimimetic could improve adherence and reduce adverse gastrointestinal effects. OBJECTIVE To evaluate the relative efficacy and safety of the IV calcimimetic etelcalcetide and the oral calcimimetic cinacalcet. DESIGN, SETTING, AND PARTICIPANTS A randomized, double-blind, double-dummy active clinical trial was conducted comparing IV etelcalcetide vs oral placebo and oral cinacalcet vs IV placebo in 683 patients receiving hemodialysis with serum parathyroid hormone (PTH) concentrations higher than 500 pg/mL on active therapy at 164 sites in the United States, Canada, Europe, Russia, and New Zealand. Patients were enrolled from August 2013 to May 2014, with end of follow-up in January 2015. INTERVENTIONS Etelcalcetide intravenously and oral placebo (n = 340) or oral cinacalcet and IV placebo (n = 343) for 26 weeks. The IV study drug was administered 3 times weekly with hemodialysis; the oral study drug was administered daily. MAIN OUTCOMES AND MEASURES The primary efficacy end point was noninferiority of etelcalcetide at achieving more than a 30% reduction from baseline in mean predialysis PTH concentrations during weeks 20-27 (noninferiority margin, 12.0%). Secondary end points included superiority in achieving biochemical end points (>50% and >30% reduction in PTH) and self-reported nausea or vomiting. RESULTS The mean (SD) age of the trial participants was 54.7 (14.1) years and 56.2% were men. Etelcalcetide was noninferior to cinacalcet on the primary end point. The estimated difference in proportions of patients achieving reduction in PTH concentrations of more than 30% between the 198 of 343 patients (57.7%) randomized to receive cinacalcet and the 232 of 340 patients (68.2%) randomized to receive etelcalcetide was -10.5% (95% CI, -17.5% to -3.5%, P for noninferiority, <.001; P for superiority, .004). One hundred seventy-eight patients (52.4%) randomized to etelcalcetide achieved more than 50% reduction in PTH concentrations compared with 138 patients (40.2%) randomized to cinacalcet (P = .001; difference in proportions, 12.2%; 95% CI, 4.7% to 19.5%). The most common adverse effect was decreased blood calcium (68.9% vs 59.8%). CONCLUSIONS AND RELEVANCE Among patients receiving hemodialysis with moderate to severe secondary hyperparathyroidism, the use of etelcalcetide was not inferior to cinacalcet in reducing serum PTH concentrations over 26 weeks; it also met superiority criteria. Further studies are needed to assess clinical outcomes as well as longer-term efficacy and safety. TRIAL REGISTRATION clinicaltrials.gov Identifier: NCT1896232.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | | | - Justin Silver
- Hadassah Hebrew University Medical Center, Jerusalem, Israel
| | - Yan Sun
- Amgen Inc, Thousand Oaks, California
| | - Hao Wang
- Amgen Inc, Thousand Oaks, California
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Affiliation(s)
- Tally Naveh-Many
- Minerva Center for Calcium and Bone Metabolism, Nephrology Services, Hadassah Hebrew University Medical Center, Jerusalem, Israel
| | - Justin Silver
- Minerva Center for Calcium and Bone Metabolism, Nephrology Services, Hadassah Hebrew University Medical Center, Jerusalem, Israel
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Affiliation(s)
- J Silver
- Departments of Medicine and Surgery, Royal Postgraduate Medical School, Ducane Road, London W12
| | - D Thomas
- Departments of Medicine and Surgery, Royal Postgraduate Medical School, Ducane Road, London W12
| | - R Young
- Departments of Medicine and Surgery, Royal Postgraduate Medical School, Ducane Road, London W12
| | - R Hermon Dowling
- Departments of Medicine and Surgery, Royal Postgraduate Medical School, Ducane Road, London W12
| | - R B Welbourn
- Departments of Medicine and Surgery, Royal Postgraduate Medical School, Ducane Road, London W12
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26
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Hassan A, Durlacher K, Silver J, Naveh-Many T, Levi R. The fibroblast growth factor receptor mediates the increased FGF23 expression in acute and chronic uremia. Am J Physiol Renal Physiol 2016; 310:F217-21. [DOI: 10.1152/ajprenal.00332.2015] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2015] [Accepted: 08/20/2015] [Indexed: 11/22/2022] Open
Abstract
Serum FGF23 is markedly elevated in chronic kidney disease and has been associated with poor long-term outcomes. FGF23 expression is increased by activation of the FGF receptor 1 (FGFR1) in rats with normal renal function and in vitro in bone-derived osteoblast-like cells. We studied the regulation of FGF23 by FGFR1 in vivo in acute and chronic uremia in mice and rats. Folic acid-induced acute kidney injury increased calvaria FGF23 mRNA and serum FGF23 and parathyroid hormone (PTH) levels at 6 h. The FGFR1 receptor inhibitor PD173074 prevented the folic acid-induced increase in both FGF23 mRNA and serum levels but had no effect on serum PTH levels. A more prolonged uremia due to an adenine high-phosphorus diet for 14 days resulted in high levels of FGF23 mRNA and serum FGF23 and PTH. PD173074 decreased serum FGF23 and mRNA levels with no effect on PTH in the adenine high phosphorus-induced uremic rats. Therefore, a derangement in FGF23 regulation starts early in the course of acute kidney injury, is in part independent of the increase in serum PTH, and involves activation of FGFR1. It is possible that FGFR1 in the osteocyte is activated by locally produced canonical FGFs, which are increased in uremia. This is the first demonstration that activation of FGFR1 is essential for the high levels of FGF23 in acute and chronic experimental uremia.
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Affiliation(s)
- Alia Hassan
- Minerva Center for Calcium and Bone Metabolism, Nephrology Services, Hadassah Hebrew University Medical Center, Jerusalem, Israel
| | - Karina Durlacher
- Minerva Center for Calcium and Bone Metabolism, Nephrology Services, Hadassah Hebrew University Medical Center, Jerusalem, Israel
| | - Justin Silver
- Minerva Center for Calcium and Bone Metabolism, Nephrology Services, Hadassah Hebrew University Medical Center, Jerusalem, Israel
| | - Tally Naveh-Many
- Minerva Center for Calcium and Bone Metabolism, Nephrology Services, Hadassah Hebrew University Medical Center, Jerusalem, Israel
| | - Ronen Levi
- Minerva Center for Calcium and Bone Metabolism, Nephrology Services, Hadassah Hebrew University Medical Center, Jerusalem, Israel
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27
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Volovelsky O, Cohen G, Kenig A, Wasserman G, Dreazen A, Meyuhas O, Silver J, Naveh-Many T. Phosphorylation of Ribosomal Protein S6 Mediates Mammalian Target of Rapamycin Complex 1-Induced Parathyroid Cell Proliferation in Secondary Hyperparathyroidism. J Am Soc Nephrol 2015; 27:1091-101. [PMID: 26283674 DOI: 10.1681/asn.2015040339] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2015] [Accepted: 06/30/2015] [Indexed: 01/03/2023] Open
Abstract
Secondary hyperparathyroidism is characterized by increased serum parathyroid hormone (PTH) level and parathyroid cell proliferation. However, the molecular pathways mediating the increased parathyroid cell proliferation remain undefined. Here, we found that the mTOR pathway was activated in the parathyroid of rats with secondary hyperparathyroidism induced by either chronic hypocalcemia or uremia, which was measured by increased phosphorylation of ribosomal protein S6 (rpS6), a downstream target of the mTOR pathway. This activation correlated with increased parathyroid cell proliferation. Inhibition of mTOR complex 1 by rapamycin decreased or prevented parathyroid cell proliferation in secondary hyperparathyroidism rats and in vitro in uremic rat parathyroid glands in organ culture. Knockin rpS6(p-/-) mice, in which rpS6 cannot be phosphorylated because of substitution of all five phosphorylatable serines with alanines, had impaired PTH secretion after experimental uremia- or folic acid-induced AKI. Uremic rpS6(p-/-) mice had no increase in parathyroid cell proliferation compared with a marked increase in uremic wild-type mice. These results underscore the importance of mTOR activation and rpS6 phosphorylation for the pathogenesis of secondary hyperparathyroidism and indicate that mTORC1 is a significant regulator of parathyroid cell proliferation through rpS6.
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Affiliation(s)
- Oded Volovelsky
- Department of Nephrology, Hadassah-Hebrew University Medical Center, and
| | - Gili Cohen
- Department of Nephrology, Hadassah-Hebrew University Medical Center, and
| | - Ariel Kenig
- Department of Nephrology, Hadassah-Hebrew University Medical Center, and
| | - Gilad Wasserman
- Department of Nephrology, Hadassah-Hebrew University Medical Center, and
| | - Avigail Dreazen
- Department of Biochemistry and Molecular Biology, Institute for Medical Research Israel-Canada, Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | - Oded Meyuhas
- Department of Biochemistry and Molecular Biology, Institute for Medical Research Israel-Canada, Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | - Justin Silver
- Department of Nephrology, Hadassah-Hebrew University Medical Center, and
| | - Tally Naveh-Many
- Department of Nephrology, Hadassah-Hebrew University Medical Center, and
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28
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Shilo V, Ben-Dov IZ, Nechama M, Silver J, Naveh-Many T. Parathyroid-specific deletion of dicer-dependent microRNAs abrogates the response of the parathyroid to acute and chronic hypocalcemia and uremia. FASEB J 2015; 29:3964-76. [PMID: 26054367 DOI: 10.1096/fj.15-274191] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2015] [Accepted: 05/26/2015] [Indexed: 11/11/2022]
Abstract
MicroRNAs (miRNAs) down-regulate gene expression and have vital roles in biology but their functions in the parathyroid are unexplored. To study this, we generated parathyroid-specific Dicer1 knockout (PT-Dicer(-/-) ) mice where parathyroid miRNA maturation is blocked. Remarkably, the PT-Dicer(-/-) mice did not increase serum parathyroid hormone (PTH) in response to acute hypocalcemia compared with the >5-fold increase in controls. PT-Dicer(-/-) glands cultured in low-calcium medium secreted 5-fold less PTH at 1.5 h than controls. Chronic hypocalcemia increased serum PTH >4-fold less in PT-Dicer(-/-) mice compared with control mice with no increase in PTH mRNA levels and parathyroid cell proliferation compared with the 2- to 3-fold increase in hypocalcemic controls. Moreover, uremic PT-Dicer(-/-) mice increased serum PTH and FGF23 significantly less than uremic controls. Therefore, stimulation of the parathyroid by both hypocalcemia and uremia is dependent upon intact dicer function and miRNAs. In contrast, the PT-Dicer(-/-) mice responded normally to activation of the parathyroid calcium-sensing receptor (Casr) by both hypercalcemia and a calcimimetic that decreases PTH secretion, demonstrating that they are dicer-independent. Therefore, miRNAs are essential for the response of the parathyroid to both acute and chronic hypocalcemia and uremia, the major stimuli for PTH secretion.
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Affiliation(s)
- Vitali Shilo
- *Minerva Center for Calcium and Bone Metabolism, Nephrology Services, Hadassah Hebrew University Medical Center, Jerusalem, Israel; and Department of Medicine, Beth Israel Deaconess Medical Center, Boston, Massachusetts, USA
| | - Iddo Z Ben-Dov
- *Minerva Center for Calcium and Bone Metabolism, Nephrology Services, Hadassah Hebrew University Medical Center, Jerusalem, Israel; and Department of Medicine, Beth Israel Deaconess Medical Center, Boston, Massachusetts, USA
| | - Morris Nechama
- *Minerva Center for Calcium and Bone Metabolism, Nephrology Services, Hadassah Hebrew University Medical Center, Jerusalem, Israel; and Department of Medicine, Beth Israel Deaconess Medical Center, Boston, Massachusetts, USA
| | - Justin Silver
- *Minerva Center for Calcium and Bone Metabolism, Nephrology Services, Hadassah Hebrew University Medical Center, Jerusalem, Israel; and Department of Medicine, Beth Israel Deaconess Medical Center, Boston, Massachusetts, USA
| | - Tally Naveh-Many
- *Minerva Center for Calcium and Bone Metabolism, Nephrology Services, Hadassah Hebrew University Medical Center, Jerusalem, Israel; and Department of Medicine, Beth Israel Deaconess Medical Center, Boston, Massachusetts, USA
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29
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Gardner RT, Wang L, Lang BT, Cregg JM, Dunbar CL, Woodward WR, Silver J, Ripplinger CM, Habecker BA. Targeting protein tyrosine phosphatase σ after myocardial infarction restores cardiac sympathetic innervation and prevents arrhythmias. Nat Commun 2015; 6:6235. [PMID: 25639594 PMCID: PMC4315356 DOI: 10.1038/ncomms7235] [Citation(s) in RCA: 72] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2014] [Accepted: 01/07/2015] [Indexed: 11/24/2022] Open
Abstract
Millions of people suffer a myocardial infarction (MI) every year, and those who survive have increased risk of arrhythmias and sudden cardiac death. Recent clinical studies have identified sympathetic denervation as a predictor of increased arrhythmia susceptibility. Chondroitin sulfate proteoglycans present in the cardiac scar after MI prevent sympathetic reinnervation by binding the neuronal protein tyrosine phosphatase receptor σ (PTPσ). Here we show that the absence of PTPσ, or pharmacologic modulation of PTPσ by the novel intracellular sigma peptide (ISP) beginning 3 days after injury, restores sympathetic innervation to the scar and markedly reduces arrhythmia susceptibility. Using optical mapping we observe increased dispersion of action potential duration, supersensitivity to β-adrenergic receptor stimulation and Ca(2+) mishandling following MI. Sympathetic reinnervation prevents these changes and renders hearts remarkably resistant to induced arrhythmias.
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Affiliation(s)
- R. T. Gardner
- Department of Physiology and Pharmacology, Neuroscience Graduate Program, Oregon Health and Science University, Portland, Oregon 97239, USA
| | - L. Wang
- Department of Pharmacology, University of California, Davis, California 95616, USA
| | - B. T. Lang
- Department of Neurosciences, Case Western Reserve University, Cleveland, Ohio 44106, USA
| | - J. M. Cregg
- Department of Neurosciences, Case Western Reserve University, Cleveland, Ohio 44106, USA
| | - C. L. Dunbar
- Department of Physiology and Pharmacology, Neuroscience Graduate Program, Oregon Health and Science University, Portland, Oregon 97239, USA
| | - W. R. Woodward
- Department of Neurology, Oregon Health and Science University, Portland, Oregon 97239, USA
| | - J. Silver
- Department of Neurosciences, Case Western Reserve University, Cleveland, Ohio 44106, USA
| | - C. M. Ripplinger
- Department of Pharmacology, University of California, Davis, California 95616, USA
| | - B. A. Habecker
- Department of Physiology and Pharmacology, Neuroscience Graduate Program, Oregon Health and Science University, Portland, Oregon 97239, USA
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30
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Darby I, Sanelli M, Shan S, Silver J, Singh A, Soedjono M, Ngo L. Comparison of clinical and cone beam computed tomography measurements to diagnose furcation involvement. Int J Dent Hyg 2014; 13:241-5. [PMID: 25511014 DOI: 10.1111/idh.12116] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/23/2014] [Indexed: 11/28/2022]
Abstract
AIM This study aimed to determine the degree of discrepancy between clinical measurement of furcation involvement (FI) and cone beam computed tomography image analysis of multirooted teeth. METHODS FI measurements obtained from clinical records were compared to CBCT images of the same teeth to determine the degree of discrepancy between CBCT FI grading and clinical FI grading. RESULTS Of the hundred and fifty-four sites analysed, 22% of FI measurements from probing and CBCT were in agreement. Fifty-eight percent of clinical FI recordings were overestimated, and 20% were underestimated when compared to CBCT analysis. CONCLUSION Clinical recording of FI is both over and underestimated compared to CBCT analysis. This was highest for probing recording grade I furcation involvement where it was highly overestimated. The occurrence of over and under estimation of FI will affect the assignment of prognosis to multirooted teeth, which can influence treatment planning for periodontal therapy and may result in inappropriate treatment.
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Affiliation(s)
- I Darby
- Periodontics, Melbourne Dental School, Carlton, Vic., Australia
| | - M Sanelli
- Periodontics, Melbourne Dental School, Carlton, Vic., Australia
| | - S Shan
- Periodontics, Melbourne Dental School, Carlton, Vic., Australia
| | - J Silver
- Periodontics, Melbourne Dental School, Carlton, Vic., Australia
| | - A Singh
- Periodontics, Melbourne Dental School, Carlton, Vic., Australia
| | - M Soedjono
- Periodontics, Melbourne Dental School, Carlton, Vic., Australia
| | - L Ngo
- Periodontics, Melbourne Dental School, Carlton, Vic., Australia
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Abstract
The metabolic changes that occur in patients with chronic kidney disease (CKD) have a profound influence on mineral and bone metabolism. CKD results in altered levels of serum phosphate, vitamin D, calcium, parathyroid hormone (PTH) and fibroblast growth factor 23 (FGF-23); the increased levels of serum phosphate, PTH and FGF-23 contribute to the increased cardiovascular mortality in affected patients. FGF-23 is produced by osteocytes and osteoblasts and acts physiologically in the kidney to induce phosphaturia and inhibit the synthesis of 1,25-dihydroxyvitamin D3. PTH acts directly on osteocytes to increase FGF-23 expression. In addition, the high levels of PTH associated with CKD contribute to changes in bone remodelling that result in decreased levels of dentin matrix protein 1 and the release of low-molecular-weight fibroblast growth factors from the bone matrix, which stimulate FGF-23 transcription. A prolonged oral phosphorus load increases FGF-23 expression by a mechanism that includes local changes in the ratio of inorganic phosphate to pyrophosphate in bone. Other factors such as dietary vitamin D compounds, calcium, and metabolic acidosis all increase FGF-23 levels. This Review discusses the mechanisms by which secondary hyperparathyroidism associated with CKD stimulates bone cells to overexpress FGF-23 levels.
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Affiliation(s)
- Justin Silver
- Hadassah Hebrew University Medical Center, Minerva Center for Calcium and Bone Metabolism, Nephrology, Ein Karem, Jerusalem 91120, Israel
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Abstract
DR ANTIGENS are polymorphic cell surface molecules whose expression is controlled by a locus closely linked or identical to the D locus of the major histocompatibility complex (MHC) of man (for reviews see refs 1, 2). They are functionally and structurally homologous to the murine la antigens determined by the I-E subregion of the MHC, a region which has been implicated in the genetic control of immune responses(3,4). Both sets of antigens are mainly expressed on cells associated with immune function (for reviews see refs 1, 2, 5), and are involved in mediating T-cell, B-cell and macrophage interactions required for the generation of immune responses(6-9). In addition, both consist of two non-covalently associated polypeptides, designated alpha and beta, with molecular weights of 34,000 and 28,000, respectively(10). The association of some DR antigens with increased susceptibility to certain diseases (for review see ref. 1) and the genetic restrictions imposed on cellular interactions by the HLA-D region(9,11) may represent the effects of structural variability among DR antigens. The aim of the studies reported here was to examine the nature and degree of structural variation among DR antigens isolated from cultured lymphoid B cells with different DR phenotypes. Such information may provide an understanding of the molecular mechanisms by which DR antigens mediate their function.
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Silver J, Russell WA. Structural polymorphism of I-E subregion antigens determined by a gene in the H-2K to I-B genetic interval. Nature 2012; 279:437-9. [PMID: 16068185 DOI: 10.1038/279437a0] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/06/1979] [Indexed: 11/09/2022]
Abstract
THE generation of immune responses in mice is influenced by Ir genes located in the I region of the major histocompatibility complex (MHC)(1). In some instances maximum responses require complementation by two genes, one in the I-A or I-B and the other in the I-E or I-C subregion(2,3). The effects of these genes are thought to be mediated by Ia alloantigens, which are cell surface molecules whose expression is controlled by the I region(4). This is based on the observations that anti-Ia sera inhibit in vitro immune responses(5,6), and soluble factors that enhance in vitro immune responses express Ia alloantigenic determinants(7,9). Jones et al.(10), using two-dimensional gel electrophoresis, observed that the expression of I-E subregion antigens is controlled by two genes, one in the I-A subregion, the other in the I-E subregion, and that the polymorphism of these antigens is influenced by an I-A subregion gene. As an explanation, the authors proposed that only one of the two polypeptide chains present in I-E immunoprecipitates is an I-E subregion product, the second being a product of the I-A subregion. Antisera obtained by cross-immunisation of I-E subregion-disparate strains of mice immunoprecipitates a molecular complex consisting of two chains, designated alpha and beta, with molecular weights of 32,000 and 29,000 respectively(11-14). Previous studies suggested that I-E antigens isolated from B10.A(5R) and B10.D2 mice had identical alpha-chains but different (beta)-chains(15). However, as these mice differed at multiple genetic regions, it was not possible to show which I subregion(s) determined the polymorphism of the E(beta) chain. Therefore, we investigated the effects of the I-A subregion on the polymorphism of I-E subregion antigens. We have now shown by peptide mapping that the I-E subregion polymorphism which Jones et al. found to be controlled by the I-A subregion probably reflects structural polymorphism of beta-chains controlled by an I-A subregion gene.
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Brinkworth JF, Pechenkina EA, Silver J, Goyert SM. Innate immune responses to TLR2 and TLR4 agonists differ between baboons, chimpanzees and humans. J Med Primatol 2012; 41:388-93. [PMID: 22978822 DOI: 10.1111/jmp.12002] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/14/2012] [Indexed: 12/17/2022]
Abstract
BACKGROUND African catarrhine primates differ in bacterial disease susceptibility. METHODS Human, chimpanzee, and baboon blood were stimulated with TLR-detected bacterial agonists and cytokine/chemokine induction assessed by real-time PCR. RESULTS Humans and chimpanzees shared similar cytokine/chemokine responses, while baboon cytokine/chemokine induction differed. Generally, responses were agonist independent. CONCLUSIONS These primates tend to generate species rather than agonist-specific responses to bacterial agonists.
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Affiliation(s)
- J F Brinkworth
- Department of Anthropology, Graduate Center, City University of New York, New York, NY, USA.
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Affiliation(s)
- Justin Silver
- Department of Nephrology, Hadassah Hebrew University Medical Center, Jerusalem, Israel.
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Abstract
Klotho and fibroblast growth factor 1 (FGFR1) are expressed not only in FGF23's classical target organ, the kidney, but also in other organs such as the parathyroid. FGF23 acts on the parathyroid to decrease PTH mRNA and serum PTH levels. It does this by activating the MAPK pathway. In chronic kidney disease there are very high levels of serum FGF23 together with increased serum PTH levels, implying resistance of the parathyroid to the action of FGF23. This has been shown in parathyroid tissue surgically removed from dialysis patients as well as in experimental models of uremia to be due to down-regulation of klotho-FGFR1 expression in the parathyroid. Moreover, the parathyroids of rats with advanced uremia do not respond to administered FGF23 by activation of the MAPK pathway or inhibition of PTH secretion. Therefore, there is down-regulation of parathyroid klotho-FGFR1 in CKD which correlates with the resistance of the parathyroid to FGF23. A further subject of great interest in this field is the effect of PTH to directly increase FGF23 expression by osteoblast like cells in culture and the observations that parathyroidectomy prevents and corrects the increased serum FGF23 level of experimental CKD as well as decreases FGF23 in patients with CKD. There is therefore a negative feedback loop between bone and the parathyroid.
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Affiliation(s)
- Justin Silver
- Hadassah Hebrew University Medical Center, Jerusalem, Israel.
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Silver J. Removing the paperwork from physical therapy. Healthc Inform 2011; 28:18-20. [PMID: 21560717] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
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Lavi-Moshayoff V, Wasserman G, Meir T, Silver J, Naveh-Many T. PTH increases FGF23 gene expression and mediates the high-FGF23 levels of experimental kidney failure: a bone parathyroid feedback loop. Am J Physiol Renal Physiol 2010; 299:F882-9. [PMID: 20685823 DOI: 10.1152/ajprenal.00360.2010] [Citation(s) in RCA: 310] [Impact Index Per Article: 22.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Parathyroid hormone (PTH) and fibroblast growth factor 23 (FGF23) target the kidney to cause a phosphaturia. FGF23 also acts on the parathyroid to decrease PTH expression, but in chronic kidney disease (CKD) there are high-serum PTH and FGF23 levels and resistance of the parathyroid to FGF23. We now report that PTH acts on bone to increase FGF23 expression and characterize the signal transduction pathway whereby PTH increases FGF23 expression. Remarkably, we show that PTH is necessary for the high-FGF23 levels of early kidney failure due to an adenine high-phosphorus diet. Parathyroidectomy before the diet totally prevented the fivefold increase in FGF23 levels in kidney failure rats. Moreover, parathyroidectomy of early kidney failure rats corrected their high-FGF23 levels. Therefore, in early kidney failure, the high-FGF23 levels are dependent on the high-PTH levels. PTH infusion for 3 days to mice with normal renal function increased serum FGF23 and calvaria FGF23 mRNA levels. To demonstrate a direct effect of PTH on FGF23, we added PTH to rat osteoblast-like UMR106 cells. PTH increased FGF23 mRNA levels (4-fold) and this effect was mimicked by a PKA activator, forskolin. PTH also decreased SOST mRNA levels (3-fold). SOST codes for sclerostin, a Wnt pathway inhibitor, which is a PTH receptor (PTH1R) target. The effect of PTH was prevented by added sclerostin. Therefore, PTH increases FGF23 expression which involves the PKA and Wnt pathways. The effect of PTH on FGF23 completes a bone-parathyroid endocrine feedback loop. Importantly, secondary hyperparathyroidism is essential for the high-FGF23 levels in early CKD.
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Affiliation(s)
- Vardit Lavi-Moshayoff
- Minerva Center for Calcium and Bone Metabolism, Nephrology Services, Hadassah Hebrew Univ. Medical Center, PO Box 12000, Jerusalem, Israel 91120
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Galitzer H, Ben-Dov IZ, Silver J, Naveh-Many T. Parathyroid cell resistance to fibroblast growth factor 23 in secondary hyperparathyroidism of chronic kidney disease. Kidney Int 2009; 77:211-8. [PMID: 20016468 DOI: 10.1038/ki.2009.464] [Citation(s) in RCA: 188] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Although fibroblast growth factor 23 (FGF23) acting through its receptor Klotho-FGFR1c decreases parathyroid hormone expression, this hormone is increased in chronic kidney disease despite an elevated serum FGF23. We measured possible factors that might contribute to the resistance of parathyroid glands to FGF23 in rats with the dietary adenine-induced model of chronic kidney disease. Quantitative immunohistochemical and reverse transcription-PCR analysis using laser capture microscopy showed that both Klotho and FGFR1 protein and mRNA levels were decreased in histological sections of the parathyroid glands. Recombinant FGF23 failed to decrease serum parathyroid hormone levels or activate the mitogen-activated protein kinase signaling pathway in the glands of rats with advanced experimental chronic kidney disease. In parathyroid gland organ culture, the addition of FGF23 decreased parathyroid hormone secretion and mRNA levels in control animals or rats with early but not advanced chronic kidney disease. Our results show that because of a downregulation of the Klotho-FGFR1c receptor complex, an increase of circulating FGF23 does not decrease parathyroid hormone levels in established chronic kidney disease. This in vivo resistance is sustained in parathyroid organ culture in vitro.
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Affiliation(s)
- H Galitzer
- Department of Nephrology, Hadassah Hebrew University Medical Center, Jerusalem, Israel
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Meir T, Levi R, Lieben L, Libutti S, Carmeliet G, Bouillon R, Silver J, Naveh-Many T. Deletion of the vitamin D receptor specifically in the parathyroid demonstrates a limited role for the receptor in parathyroid physiology. Am J Physiol Renal Physiol 2009; 297:F1192-8. [DOI: 10.1152/ajprenal.00360.2009] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
1,25(OH)2D3 decreases parathyroid hormone (PTH) gene transcription through the vitamin D receptor (VDR). Total body VDR−/− mice have high PTH levels, hypocalcemia, hypophosphatemia, and bone malformations. To investigate PTH regulation by the VDR specifically in the parathyroid, we generated parathyroid-specific VDR knockout mice ( PT-VDR−/−). In both strains, there was a decrease in parathyroid calcium receptor (CaR) levels. The number of proliferating parathyroid cells was increased in the VDR−/− mice but not in the PT-VDR−/− mice. Serum PTH levels were moderately but significantly increased in the PT-VDR−/− mice with normal serum calcium levels. The sensitivity of the parathyroid glands of the PT-VDR−/− mice to calcium was intact as measured by serum PTH levels after changes in serum calcium. This indicates that the reduced CaR in the PT-VDR−/− mice enables a physiologic response to serum calcium. Serum C-terminal collagen crosslinks, a marker of bone resorption, were increased in the PT-VDR−/− mice with no change in the bone formation marker, serum osteocalcin, consistent with a resorptive effect due to the increased serum PTH levels in the PT-VDR−/− mice. Therefore, deletion of the VDR specifically in the parathyroid decreases parathyroid CaR expression and only moderately increases basal PTH levels, suggesting that the VDR has a limited role in parathyroid physiology.
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Affiliation(s)
- Tomer Meir
- Minerva Center for Calcium and Bone Metabolism, Nephrology Services, Hadassah Hospital, Jerusalem, Israel
| | - Ronen Levi
- Minerva Center for Calcium and Bone Metabolism, Nephrology Services, Hadassah Hospital, Jerusalem, Israel
| | - Liesbet Lieben
- Laboratory of Experimental Medicine and Endocrinology, Katholieke Universiteit Leuven, Leuven, Belgium
| | | | - Geert Carmeliet
- Laboratory of Experimental Medicine and Endocrinology, Katholieke Universiteit Leuven, Leuven, Belgium
| | - Roger Bouillon
- Laboratory of Experimental Medicine and Endocrinology, Katholieke Universiteit Leuven, Leuven, Belgium
| | - Justin Silver
- Minerva Center for Calcium and Bone Metabolism, Nephrology Services, Hadassah Hospital, Jerusalem, Israel
| | - Tally Naveh-Many
- Minerva Center for Calcium and Bone Metabolism, Nephrology Services, Hadassah Hospital, Jerusalem, Israel
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Nechama M, Uchida T, Mor Yosef-Levi I, Silver J, Naveh-Many T. The peptidyl-prolyl isomerase Pin1 determines parathyroid hormone mRNA levels and stability in rat models of secondary hyperparathyroidism. J Clin Invest 2009; 119:3102-14. [PMID: 19770516 DOI: 10.1172/jci39522] [Citation(s) in RCA: 78] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2009] [Accepted: 07/15/2009] [Indexed: 11/17/2022] Open
Abstract
Secondary hyperparathyroidism is a major complication of chronic kidney disease (CKD). In experimental models of secondary hyperparathyroidism induced by hypocalcemia or CKD, parathyroid hormone (PTH) mRNA levels increase due to increased PTH mRNA stability. K-homology splicing regulator protein (KSRP) decreases the stability of PTH mRNA upon binding a cis-acting element in the PTH mRNA 3' UTR region. As the peptidyl-prolyl isomerase (PPIase) Pin1 has recently been shown to regulate the turnover of multiple cytokine mRNAs, we investigated the role of Pin1 in regulating PTH mRNA stability in rat parathyroids and transfected cells. The data generated were consistent with Pin1 being a PTH mRNA destabilizing protein. Initial analysis indicated that Pin1 activity was decreased in parathyroid protein extracts from both hypocalcemic and CKD rats and that pharmacologic inhibition of Pin1 increased PTH mRNA levels posttranscriptionally in rat parathyroid and in transfected cells. Pin1 mediated its effects via interaction with KSRP, which led to KSRP dephosphorylation and activation. In the rat parathyroid, Pin1 inhibition decreased KSRP-PTH mRNA interactions, increasing PTH mRNA levels. Furthermore, Pin1-/- mice displayed increased serum PTH and PTH mRNA levels, suggesting that Pin1 determines basal PTH expression in vivo. These results demonstrate that Pin1 is a key mediator of PTH mRNA stability and indicate a role for Pin1 in the pathogenesis of secondary hyperparathyroidism in individuals with CKD.
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Affiliation(s)
- Morris Nechama
- Minerva Center for Calcium and Bone Metabolism, Nephrology Services, Hadassah Hebrew University Medical Center, Jerusalem, Israel
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Silver J. Re: Case report: a fatal metastasis of Klebsiella pneumonia to the lungs. Spinal Cord 2009; 47:901-2. [PMID: 19636330 DOI: 10.1038/sc.2009.96] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Abstract
To study the regulation of the human PTH (hPTH) gene in vivo, we generated transgenic mice with the hPTH gene expressed in the mouse parathyroid using a bacterial artificial chromosome (BAC) containing the hPTH gene within its 144-kb chromosomal region. The BAC construct maintains the native hPTH gene surrounding sequences and isolates it from positional effects. The transgenic mice had normal levels of serum mouse PTH (mPTH) in addition to both intact and bioactive hPTH. Despite the presence of both mPTH and hPTH, serum calcium and 1,25(OH)(2) vitamin D levels were normal. The lack of response to hPTH may be due to tachyphylaxis of the mPTH receptor (PTH1R) and/or impaired recognition of the mPTH1R. In contrast, the regulation of hPTH levels in the mouse was intact. A calcium-depleted diet increased serum mPTH and both intact and bioactive hPTH. mPTH and hPTH mRNA levels were also markedly increased. The calcimimetic R-568 dramatically decreased mPTH and hPTH serum levels. Administered recombinant fibroblast growth factor (FGF)23 decreased hPTH. Therefore, the regulation of hPTH gene expression and serum hPTH levels is intact in the transgenic mice, indicating preservation of the signal transduction of the parathyroid calcium receptor and the Klotho-FGF receptor between mouse and man.
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Affiliation(s)
- Vardit Lavi-Moshayoff
- Nephrology Services, Hadassah Hebrew University Medical Center, P. O. Box 12000, Jerusalem, Israel 91120
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Galitzer H, Lavi-Moshayoff V, Nechama M, Meir T, Silver J, Naveh-Many T. The calcium-sensing receptor regulates parathyroid hormone gene expression in transfected HEK293 cells. BMC Biol 2009; 7:17. [PMID: 19397786 PMCID: PMC2681451 DOI: 10.1186/1741-7007-7-17] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2008] [Accepted: 04/27/2009] [Indexed: 11/10/2022] Open
Abstract
Background The parathyroid calcium receptor determines parathyroid hormone secretion and the response of parathyroid hormone gene expression to serum Ca2+ in the parathyroid gland. Serum Ca2+ regulates parathyroid hormone gene expression in vivo post-transcriptionally affecting parathyroid hormone mRNA stability through the interaction of trans-acting proteins to a defined cis element in the parathyroid hormone mRNA 3'-untranslated region. These parathyroid hormone mRNA binding proteins include AUF1 which stabilizes and KSRP which destabilizes the parathyroid hormone mRNA. There is no parathyroid cell line; therefore, we developed a parathyroid engineered cell using expression vectors for the full-length human parathyroid hormone gene and the human calcium receptor. Results Co-transfection of the human calcium receptor and the human parathyroid hormone plasmid into HEK293 cells decreased parathyroid hormone mRNA levels and secreted parathyroid hormone compared with cells that do not express the calcium receptor. The decreased parathyroid hormone mRNA correlated with decreased parathyroid hormone mRNA stability in vitro, which was dependent upon the 3'-UTR cis element. Moreover, parathyroid hormone gene expression was regulated by Ca2+ and the calcimimetic R568, in cells co-transfected with the calcium receptor but not in cells without the calcium receptor. RNA immunoprecipitation analysis in calcium receptor-transfected cells showed increased KSRP-parathyroid hormone mRNA binding and decreased binding to AUF1. The calcium receptor led to post-translational modifications in AUF1 as occurs in the parathyroid in vivo after activation of the calcium receptor. Conclusion The expression of the calcium receptor is sufficient to confer the regulation of parathyroid hormone gene expression to these heterologous cells. The calcium receptor decreases parathyroid hormone gene expression in these engineered cells through the parathyroid hormone mRNA 3'-UTR cis element and the balanced interactions of the trans-acting factors KSRP and AUF1 with parathyroid hormone mRNA, as in vivo in the parathyroid. This is the first demonstration that the calcium receptor can regulate parathyroid hormone gene expression in heterologous cells.
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Affiliation(s)
- Hillel Galitzer
- Minerva Center for Calcium and Bone Metabolism, Nephrology Services, Hadassah-Hebrew University Medical Center, Jerusalem, Israel.
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Nechama M, Ben-Dov IZ, Silver J, Naveh-Many T. Regulation of PTH mRNA stability by the calcimimetic R568 and the phosphorus binder lanthanum carbonate in CKD. Am J Physiol Renal Physiol 2009; 296:F795-800. [DOI: 10.1152/ajprenal.90625.2008] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Secondary hyperparathyroidism is characterized by increased parathyroid hormone (PTH) mRNA stability that leads to increased PTH mRNA and serum PTH levels. PTH gene expression is reduced by the calcimimetic R568 and the oral phosphorus binder lanthanum carbonate (La). Changes in PTH mRNA stability are regulated by the binding of trans-acting stabilizing and destabilizing factors to a defined cis element in the PTH mRNA 3′-untranslated region (UTR). Adenosine-uridine (AU)-binding factor 1 (AUF1) is a PTH mRNA-stabilizing protein, and K-homology splicing regulatory protein (KSRP) is a destabilizing protein that targets mRNAs, including PTH mRNA, to degradation by the ribonuclease complex exosome. We now show that KSRP-PTH mRNA binding is decreased in parathyroids from rats with adenine-induced chronic kidney disease (CKD) where PTH mRNA is more stable. KSRP-PTH mRNA binding is increased by treatment with both R568 and La, correlating with decreased PTH gene expression. In vitro degradation assays using transcripts for PTH mRNA and rat parathyroid extracts reproduce the differences in mRNA stability in vivo. Accordingly, PTH mRNA is destabilized in vitro by parathyroid extracts from CKD rats treated with R568 or La compared with parathyroid extracts from untreated CKD rats. This destabilizing effect of R568 and La is dependent on KSRP and the PTH mRNA 3′-UTR. Therefore, the calcimimetic R568 and correction of serum phosphorus by La determine PTH mRNA stability through KSRP-mediated recruitment of a degradation complex to the PTH mRNA, thereby decreasing PTH expression.
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Abstract
The phosphate (Pi) retention in patients with chronic kidney disease leads to secondary hyperparathyroidism (2HPT). 2HPT is the physiological response of the parathyroid not only to Pi retention but also to decreased synthesis of 1,25(OH)(2) vitamin D, and the attendant hypocalcemia. 2HPT is characterized by increased PTH synthesis, secretion, and parathyroid cell proliferation. Extracellular fluid (ECF) Ca(2+) is recognized by the parathyroid calcium receptor and a small decrease in the ECF Ca(2+) results in relaxation of the calcium receptor and allows the unrestrained secretion and synthesis of PTH and in the longer term, parathyroid cell proliferation. Both 1,25(OH)(2) vitamin D and fibroblast growth factor 23 inhibit PTH gene expression and secretion. Secondary hyperparathyroidism can initially be controlled by a single therapeutic intervention, such as a Pi-restricted diet, a calcimimetic, or an active vitamin D analog. In this review we discuss the mechanisms whereby Pi regulates the parathyroid. Pi has a direct effect on the parathyroid which requires intact parathyroid tissue architecture. The effect of Pi, as of Ca(2+), on PTH gene expression is post-transcriptional and involves the regulated interaction of parathyroid cytosolic proteins to a defined cis acting sequence in the PTH mRNA. Changes in serum Ca(2+) or Pi regulate the activity of trans acting interacting proteins in the parathyroid, which alters their binding to a defined 26 nucleotide cis acting instability sequence in the PTH mRNA 3'-untranslated region. The trans factors are either stabilizing or destabilizing factors and their regulated binding to the PTH cis acting element determines the PTH mRNA half-life. The responses of the parathyroid to changes in serum Pi are now being revealed but the sensing mechanisms remain a mystery.
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Affiliation(s)
- Justin Silver
- Minerva Center for Calcium and Bone Metabolism, Nephrology Services, Hadassah Hebrew University Medical Center, Jerusalem, Israel.
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Silver J, Withnall R, Ireland TG, Fern GR, Zhang S. Light-emitting nanocasts formed from bio-templates: FESEM and cathodoluminescent imaging studies of butterfly scale replicas. Nanotechnology 2008; 19:095302. [PMID: 21817666 DOI: 10.1088/0957-4484/19/9/095302] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Nanocasts comprising of red-light-emitting cubic Y(2)O(3):Eu phosphors were made from butterfly wing scale bio-templates. We report herein the first cathodoluminescent images made from such nanocasts and show that valuable insights into the nature of the internal structure of the casts can be gained by the use of this technique. The casts faithfully reproduced the fine sub-micrometre size detail of the scales, as was made evident by both FESEM and cathodoluminescent images that were collected from the same sample areas using a hyphenated FESEM-CL instrument. There was excellent agreement between the FESEM and cathodoluminescent images, the image quality of the latter indicating that the Eu(3+) activator ions were evenly dispersed in the Y(2)O(3):Eu phosphor on a sub-micrometre scale. The casts were made by infilling the natural moulds with a Y(2)O(3):Eu precursor solution that was subsequently dried and fired to convert it into the phosphor material. This method provides a simple, low cost route for fabricating nanostructures having feature dimensions as small as 20 nm in size, and it has the potential to be applied to other metal oxide systems for producing nano-and micro-components for electronic, magnetic or photonic integrated systems.
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Ben-Dov IZ, Galitzer H, Lavi-Moshayoff V, Goetz R, Kuro-o M, Mohammadi M, Sirkis R, Naveh-Many T, Silver J. The parathyroid is a target organ for FGF23 in rats. J Clin Invest 2008; 117:4003-8. [PMID: 17992255 DOI: 10.1172/jci32409] [Citation(s) in RCA: 395] [Impact Index Per Article: 24.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2007] [Accepted: 09/05/2007] [Indexed: 12/11/2022] Open
Abstract
Phosphate homeostasis is maintained by a counterbalance between efflux from the kidney and influx from intestine and bone. FGF23 is a bone-derived phosphaturic hormone that acts on the kidney to increase phosphate excretion and suppress biosynthesis of vitamin D. FGF23 signals with highest efficacy through several FGF receptors (FGFRs) bound by the transmembrane protein Klotho as a coreceptor. Since most tissues express FGFR, expression of Klotho determines FGF23 target organs. Here we identify the parathyroid as a target organ for FGF23 in rats. We show that the parathyroid gland expressed Klotho and 2 FGFRs. The administration of recombinant FGF23 led to an increase in parathyroid Klotho levels. In addition, FGF23 activated the MAPK pathway in the parathyroid through ERK1/2 phosphorylation and increased early growth response 1 mRNA levels. Using both rats and in vitro rat parathyroid cultures, we show that FGF23 suppressed both parathyroid hormone (PTH) secretion and PTH gene expression. The FGF23-induced decrease in PTH secretion was prevented by a MAPK inhibitor. These data indicate that FGF23 acts directly on the parathyroid through the MAPK pathway to decrease serum PTH. This bone-parathyroid endocrine axis adds a new dimension to the understanding of mineral homeostasis.
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Affiliation(s)
- Iddo Z Ben-Dov
- Minerva Center for Calcium and Bone Metabolism, Nephrology Services, Hadassah Hebrew University Medical Center, Jerusalem, Israel
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