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David K, Devos G, Narinx N, Antonio L, Devlies W, Deboel L, Schollaert D, Eisenhauer A, Cavalier E, Vanderschueren D, Claessens F, Joniau S, Decallonne B. Changes in bone and mineral homeostasis after short-term androgen deprivation therapy with or without androgen receptor signalling inhibitor - substudy of a single-centre, double blind, randomised, placebo-controlled phase 2 trial. EBioMedicine 2023; 97:104817. [PMID: 37804569 PMCID: PMC10570709 DOI: 10.1016/j.ebiom.2023.104817] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2023] [Revised: 09/16/2023] [Accepted: 09/17/2023] [Indexed: 10/09/2023] Open
Abstract
BACKGROUND Prostate cancer (PCa) patients treated with androgen deprivation therapy (ADT) have an increased fracture risk. Exploring biomarkers for early bone loss detection is of great interest. METHODS Pre-planned substudy of the ARNEO-trial (NCT03080116): a double blind, randomised, placebo-controlled phase 2 trial performed in high-risk PCa patients without bone metastases between March 2019 and April 2021. Patients were 1:1 randomised to treatment with gonadotropin-releasing hormone antagonist (degarelix) + androgen receptor signalling inhibitor (ARSI; apalutamide) versus degarelix + matching placebo for 12 weeks prior to prostatectomy. Before and following ADT, serum and 24-h urinary samples were collected. Primary endpoints were changes in calcium-phosphate homeostasis and bone biomarkers. FINDINGS Of the 89 randomised patients, 43 in the degarelix + apalutamide and 44 patients in the degarelix + placebo group were included in this substudy. Serum corrected calcium levels increased similarly in both treatment arms (mean difference +0.04 mmol/L, 95% confidence interval, 0.02; 0.06), and parathyroid hormone and 1,25-dihydroxyvitamin D3 levels decreased. Bone resorption markers increased, and stable calcium isotope ratios reflecting net bone mineral balance decreased in serum and urine similarly in both groups. INTERPRETATION This exploratory substudy suggests that 12 weeks of ADT in non-metastatic PCa patients results in early bone loss. Additional treatment with ARSI does not seem to more negatively influence bone loss in the early phase. Future studies should address if these early biomarkers are able to predict fracture risk, and can be implemented in clinical practice for follow-up of bone health in PCa patients under ADT. FUNDING Research Foundation Flanders; KU Leuven; University-Hospitals-Leuven.
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Affiliation(s)
- Karel David
- Clinical and Experimental Endocrinology, Department of Chronic Diseases and Metabolism, KU Leuven, Leuven, Belgium; Department of Endocrinology, University Hospitals Leuven, Leuven, Belgium
| | - Gaëtan Devos
- Department of Urology, University Hospitals Leuven, Leuven, Belgium; Urogenital, Abdominal and Plastic Surgery, Department of Development and Regeneration, KU Leuven, Leuven, Belgium
| | - Nick Narinx
- Clinical and Experimental Endocrinology, Department of Chronic Diseases and Metabolism, KU Leuven, Leuven, Belgium; Department of Laboratory Medicine, University Hospitals Leuven, Leuven, Belgium
| | - Leen Antonio
- Clinical and Experimental Endocrinology, Department of Chronic Diseases and Metabolism, KU Leuven, Leuven, Belgium; Department of Endocrinology, University Hospitals Leuven, Leuven, Belgium
| | - Wout Devlies
- Department of Urology, University Hospitals Leuven, Leuven, Belgium; Urogenital, Abdominal and Plastic Surgery, Department of Development and Regeneration, KU Leuven, Leuven, Belgium; Molecular Endocrinology, Department of Cellular and Molecular Medicine, KU Leuven, Leuven, Belgium
| | - Ludo Deboel
- Clinical and Experimental Endocrinology, Department of Chronic Diseases and Metabolism, KU Leuven, Leuven, Belgium
| | - Dieter Schollaert
- Clinical and Experimental Endocrinology, Department of Chronic Diseases and Metabolism, KU Leuven, Leuven, Belgium
| | - Anton Eisenhauer
- Geomar Helmholtz Centre for Ocean Research Kiel, Kiel, Germany; Osteolabs GmbH, Kiel, Germany
| | - Etienne Cavalier
- Department of Clinical Chemistry, University of Liège, Liège, Belgium
| | - Dirk Vanderschueren
- Clinical and Experimental Endocrinology, Department of Chronic Diseases and Metabolism, KU Leuven, Leuven, Belgium; Department of Endocrinology, University Hospitals Leuven, Leuven, Belgium
| | - Frank Claessens
- Molecular Endocrinology, Department of Cellular and Molecular Medicine, KU Leuven, Leuven, Belgium
| | - Steven Joniau
- Department of Urology, University Hospitals Leuven, Leuven, Belgium; Urogenital, Abdominal and Plastic Surgery, Department of Development and Regeneration, KU Leuven, Leuven, Belgium
| | - Brigitte Decallonne
- Clinical and Experimental Endocrinology, Department of Chronic Diseases and Metabolism, KU Leuven, Leuven, Belgium; Department of Endocrinology, University Hospitals Leuven, Leuven, Belgium.
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Rott J, Töpfer ET, Bartosova M, Damgov I, Kolevica A, Heuser A, Shroff R, Zarogiannis SG, Eisenhauer A, Schmitt CP. Calcimimetic AMG-416 induced short-term changes in calcium concentrations and calcium isotope ratios in rats. Biochem Biophys Res Commun 2023; 677:88-92. [PMID: 37562340 DOI: 10.1016/j.bbrc.2023.07.060] [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: 07/11/2023] [Revised: 07/19/2023] [Accepted: 07/31/2023] [Indexed: 08/12/2023]
Abstract
Calcium (Ca) isotopes (δ44/42Ca) in serum and urine have been suggested as novel sensitive markers of bone calcification. The response of δ44/42Ca to acute changes in Ca homeostasis, has not yet been demonstrated. We measured serum Ca and δ44/42Ca in rats maintained on a standard and a 50% Ca reduced diet for 4 weeks, and after injection of 1 mg/kg of the calcimimetic AMG-416, 24 h prior to sacrifice. AMG-416 decreased serum Ca by a maximum of 0.38 ± 0.10 and 0.53 ± 0.35 mmol/l after 12 and 6 h, respectively, in the standard and low-Ca diet groups (p = 0.0006/0.02), while serum δ44/42Ca did not change over 24 h in both groups. Urinary Ca concentrations were higher 24 h after AMG-416 injection in both groups (p = 0.03/0.06), urine δ44/42Ca was not different compared to the untreated control groups. Our data does not show acute changes in δ44/42Ca in response to a single dose of AMG-416 within 24 h after injection, possibly due to a lack of bone calcification.
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Affiliation(s)
- Jeremy Rott
- Center for Pediatric and Adolescent Medicine, University of Heidelberg, Im Neuenheimer Feld 430, 69120, Heidelberg, Germany
| | - Eva Teresa Töpfer
- Center for Pediatric and Adolescent Medicine, University of Heidelberg, Im Neuenheimer Feld 430, 69120, Heidelberg, Germany
| | - Maria Bartosova
- Center for Pediatric and Adolescent Medicine, University of Heidelberg, Im Neuenheimer Feld 430, 69120, Heidelberg, Germany
| | - Ivan Damgov
- Center for Pediatric and Adolescent Medicine, University of Heidelberg, Im Neuenheimer Feld 430, 69120, Heidelberg, Germany
| | - Ana Kolevica
- GEOMAR Helmholtz Centre for Ocean Research Kiel, 24148, Kiel, Germany
| | - Alexander Heuser
- GEOMAR Helmholtz Centre for Ocean Research Kiel, 24148, Kiel, Germany
| | - Rukshana Shroff
- Renal Unit, University College London Great Ormond Street Hospital and Institute of Child Health, London, UK
| | - Sotirios G Zarogiannis
- Center for Pediatric and Adolescent Medicine, University of Heidelberg, Im Neuenheimer Feld 430, 69120, Heidelberg, Germany
| | - Anton Eisenhauer
- GEOMAR Helmholtz Centre for Ocean Research Kiel, 24148, Kiel, Germany
| | - Claus Peter Schmitt
- Center for Pediatric and Adolescent Medicine, University of Heidelberg, Im Neuenheimer Feld 430, 69120, Heidelberg, Germany.
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Gischler E, Hudson JH, Eisenhauer A, Parang S, Deveaux M. 9000 years of change in coral community structure and accretion in Belize reefs, western Atlantic. Sci Rep 2023; 13:11349. [PMID: 37443199 PMCID: PMC10345111 DOI: 10.1038/s41598-023-38118-5] [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: 12/16/2022] [Accepted: 07/03/2023] [Indexed: 07/15/2023] Open
Abstract
Tropical coral reefs, as prominent marine diversity hotspots, are in decline, and long-term studies help to improve understanding of the effects of global warming, sea-level rise, ocean acidification, deterioration of water quality, and disease. Here, we evaluated relative coral abundance and reef accretion rates over the past 9000 years in Belize barrier and atoll reefs, the largest reef system in the Atlantic Ocean. Acropora palmata and Orbicella spp. have been the most common corals. The abundance of competitive, fast-growing acroporids was constant over multi-millennial timescales. A decline in A. cervicornis abundance, however, and three centennial-scale gaps in A. palmata occurrence, suggest that the modern decline in acroporids was not unprecedented. Stress-tolerant corals predominate at the beginning of Holocene successions. Following the improvement of environmental conditions after inundation of the reef pedestal, their abundance has decreased. The abundance of weedy corals has increased during the Holocene underlining the importance of fecundity for the coral community. Reef-accretion rate, as calculated based on 76 new U-series age dates, has decreased over the Holocene and the mean value of 3.36 m kyr-1 is at the lower end of global reef growth compilations and predicted future rates of rise in sea level.
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Affiliation(s)
- Eberhard Gischler
- Institute of Geosciences, Goethe-University, 60438, Frankfurt am Main, Germany.
| | | | | | - Soran Parang
- Department of Earth and Environmental Sciences, University of Ottawa, Ottawa, ON, K1N 6N5, Canada
| | - Michael Deveaux
- GSI Helmholtz Center of Heavy Ion Research, 64291, Darmstadt, Germany
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Coombs CV, Wardle SL, Shroff R, Eisenhauer A, Tang JCY, Fraser WD, Greeves JP, O'Leary TJ. The effect of calcium supplementation on calcium and bone metabolism during load carriage in women: protocol for a randomised controlled crossover trial. BMC Musculoskelet Disord 2023; 24:496. [PMID: 37328859 DOI: 10.1186/s12891-023-06600-w] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/17/2023] [Accepted: 06/02/2023] [Indexed: 06/18/2023] Open
Abstract
BACKGROUND Military field exercises are characterised by high volumes of exercise and prolonged periods of load carriage. Exercise can decrease circulating serum calcium and increase parathyroid hormone and bone resorption. These disturbances to calcium and bone metabolism can be attenuated with calcium supplementation immediately before exercise. This randomised crossover trial will investigate the effect of calcium supplementation on calcium and bone metabolism, and bone mineral balance, during load carriage exercise in women. METHODS Thirty women (eumenorrheic or using the combined oral contraceptive pill, intrauterine system, or intrauterine device) will complete two experimental testing sessions either with, or without, a calcium supplement (1000 mg). Each experimental testing session will involve one 120 min session of load carriage exercise carrying 20 kg. Venous blood samples will be taken and analysed for biochemical markers of bone resorption and formation, calcium metabolism, and endocrine function. Urine will be collected pre- and post-load carriage to measure calcium isotopes for the calculation of bone calcium balance. DISCUSSION The results from this study will help identify whether supplementing women with calcium during load carriage is protective of bone and calcium homeostasis. TRIAL REGISTRATION NCT04823156 (clinicaltrials.gov).
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Affiliation(s)
- Charlotte V Coombs
- Army Health and Performance Research, Army Headquarters, Andover, SP11 8HT, UK
| | - Sophie L Wardle
- Army Health and Performance Research, Army Headquarters, Andover, SP11 8HT, UK
| | - Rukshana Shroff
- Renal Unit, UCL Great Ormond Street Hospital for Children NHS Foundation Trust and Institute of Child Health, London, UK
| | | | | | | | - Julie P Greeves
- Army Health and Performance Research, Army Headquarters, Andover, SP11 8HT, UK
| | - Thomas J O'Leary
- Army Health and Performance Research, Army Headquarters, Andover, SP11 8HT, UK.
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Shroff R, Lalayiannis AD, Fewtrell M, Schmitt CP, Bayazit A, Askiti V, Jankauskiene A, Bacchetta J, Silva S, Goodman N, McAlister L, Biassoni L, Crabtree N, Rahn A, Fischer DC, Heuser A, Kolevica A, Eisenhauer A. Naturally occurring stable calcium isotope ratios are a novel biomarker of bone calcium balance in chronic kidney disease. Kidney Int 2022; 102:613-623. [DOI: 10.1016/j.kint.2022.04.024] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2022] [Revised: 04/10/2022] [Accepted: 04/18/2022] [Indexed: 11/28/2022]
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Raddatz J, Liebetrau V, Rüggeberg A, Foubert A, Flögel S, Nürnberg D, Hissmann K, Musiol J, Goepfert TJ, Eisenhauer A, Dullo WC. Living on the edge: environmental variability of a shallow late Holocene cold-water coral mound. Coral Reefs 2022; 41:1255-1271. [PMID: 35912336 PMCID: PMC9325858 DOI: 10.1007/s00338-022-02249-4] [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] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2021] [Accepted: 03/19/2022] [Indexed: 06/01/2023]
Abstract
UNLABELLED Similar to their tropical counterparts, cold-water corals (CWCs) are able to build large three-dimensional reef structures. These unique ecosystems are at risk due to ongoing climate change. In particular, ocean warming, ocean acidification and changes in the hydrological cycle may jeopardize the existence of CWCs. In order to predict how CWCs and their reefs or mounds will develop in the near future one important strategy is to study past fossil CWC mounds and especially shallow CWC ecosystems as they experience a greater environmental variability compared to other deep-water CWC ecosystems. We present results from a CWC mound off southern Norway. A sediment core drilled from this relatively shallow (~ 100 m) CWC mound exposes in full detail hydrographical changes during the late Holocene, which were crucial for mound build-up. We applied computed tomography, 230Th/U dating, and foraminiferal geochemical proxy reconstructions of bottom-water-temperature (Mg/Ca-based BWT), δ18O for seawater density, and the combination of both to infer salinity changes. Our results demonstrate that the CWC mound formed in the late Holocene between 4 kiloannum (ka) and 1.5 ka with an average aggradation rate of 104 cm/kiloyears (kyr), which is significantly lower than other Holocene Norwegian mounds. The reconstructed BWTMg/Ca and seawater density exhibit large variations throughout the entire period of mound formation, but are strikingly similar to modern in situ observations in the nearby Tisler Reef. We argue that BWT does not exert a primary control on CWC mound formation. Instead, strong salinity and seawater density variation throughout the entire mound sequence appears to be controlled by the interplay between the Atlantic Water (AW) inflow and the overlying, outflowing Baltic-Sea water. CWC growth and mound formation in the NE Skagerrak was supported by strong current flow, oxygen replenishment, the presence of a strong boundary layer and larval dispersal through the AW, but possibly inhibited by the influence of fresh Baltic Water during the late Holocene. Our study therefore highlights that modern shallow Norwegian CWC reefs may be particularly endangered due to changes in water-column stratification associated with increasing net precipitation caused by climate change. SUPPLEMENTARY INFORMATION The online version contains supplementary material available at 10.1007/s00338-022-02249-4.
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Affiliation(s)
- Jacek Raddatz
- Institute of Geosciences, Goethe University Frankfurt, Altenhöferallee 1, 60438 Frankfurt, Germany
| | - Volker Liebetrau
- GEOMAR Helmholtz Centre for Ocean Research Kiel, Wischhofstr. 1-3, 24148 Kiel, Germany
| | - Andres Rüggeberg
- Department of Geosciences, University of Fribourg, Chemin du Musée 6, 1700 Fribourg, Switzerland
| | - Anneleen Foubert
- Department of Geosciences, University of Fribourg, Chemin du Musée 6, 1700 Fribourg, Switzerland
| | - Sascha Flögel
- GEOMAR Helmholtz Centre for Ocean Research Kiel, Wischhofstr. 1-3, 24148 Kiel, Germany
| | - Dirk Nürnberg
- GEOMAR Helmholtz Centre for Ocean Research Kiel, Wischhofstr. 1-3, 24148 Kiel, Germany
| | - Karen Hissmann
- GEOMAR Helmholtz Centre for Ocean Research Kiel, Wischhofstr. 1-3, 24148 Kiel, Germany
| | - Johannes Musiol
- GEOMAR Helmholtz Centre for Ocean Research Kiel, Wischhofstr. 1-3, 24148 Kiel, Germany
| | - Tyler Jay Goepfert
- GEOMAR Helmholtz Centre for Ocean Research Kiel, Wischhofstr. 1-3, 24148 Kiel, Germany
- Present Address: School of Earth & Space Exploration, Arizona State University, Tempe, AZ 85287-1404 USA
| | - Anton Eisenhauer
- GEOMAR Helmholtz Centre for Ocean Research Kiel, Wischhofstr. 1-3, 24148 Kiel, Germany
| | - Wolf-Christian Dullo
- GEOMAR Helmholtz Centre for Ocean Research Kiel, Wischhofstr. 1-3, 24148 Kiel, Germany
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Spielhagen RF, Scholten JC, Bauch HA, Eisenhauer A. No freshwater-filled glacial Arctic Ocean. Nature 2022; 602:E1-E3. [PMID: 35110751 DOI: 10.1038/s41586-021-04089-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Accepted: 10/01/2021] [Indexed: 11/09/2022]
Affiliation(s)
| | - Jan C Scholten
- Institute for Geosciences, Kiel University, Kiel, Germany
| | - Henning A Bauch
- GEOMAR Helmholtz Centre for Ocean Research, Kiel, Germany.,Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, Bremerhaven, Germany
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Fischer DC, Sckell A, Garkisch A, Dresing K, Eisenhauer A, Valentini L, Mittlmeier T. Treatment of perioperative swelling by rest, ice, compression, and elevation (RICE) without and with additional application of negative pressure (RICE +) in patients with a unilateral ankle fracture: study protocol for a monocentric, evaluator-blinded randomized controlled pilot trial. Pilot Feasibility Stud 2021; 7:203. [PMID: 34772457 PMCID: PMC8588602 DOI: 10.1186/s40814-021-00944-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2021] [Accepted: 11/01/2021] [Indexed: 11/28/2022] Open
Abstract
Background Edema is commonly seen after surgical fixation of ankle fractures. Rest, ice, compression, and elevation (RICE) is an established combination to prevent swelling but hardly able to stimulate lymphatic resorption. Recently, an epicutaneously applied negative pressure suction apparatus (LymphaTouch®) has been introduced to stimulate lymphatic flow. While postoperative recovery, soft tissue, and osseous healing as well as functional outcome are probably linked to the amount of postoperative swelling, estimates on this relative to prevention (RICE) or prevention + stimulated resorption (RICE+) of fluid are scarce. Methods and analysis This is a single-center, evaluator-blinded randomized pilot trial to investigate postoperative swelling in adults requiring surgical fixation of a closed unilateral ankle fracture. A total of 50 patients will be recruited and randomly assigned to RICE or RICE+ prior to surgery. All patients will undergo evaluator-blinded measurements of the ankle volume the day before surgery and subsequently from the evening of the 2nd postoperative day every 24 h until discharge. RICE will be initiated right after surgery and continued until discharge from the hospital in all patients. Additional application of negative pressure therapy (RICE+) will be initiated on the morning of the 2nd postoperative day and repeated every 24 h until the time of discharge from the hospital. Outcome measures are (i) the relative amount and the time course of the postoperative swelling, (ii) the demand for analgesic therapy (type and amount) together with the perception of pain, (iii) the rate of complications, and (iv) mobility of the ankle joint and the recovery of walking abilities during a 12-weeks follow-up period. Serum and urine samples taken prior to sugery and during postoperative recovery will allow to evaluate the ratio of naturally occurring stable calcium isotopes (δ44/42Ca) as a marker of skeletal calcium accrual. Ethics and dissemination The protocol was approved by the institutional Ethics Committee (Rostock University Medical Center, Rostock, Germany) in accordance with the Declaration of Helsinki (approval number: A 2020-0092). The results of this study will be actively disseminated through scientific publications and conference presentations. Trial registration DRKS, DRKS00023739. Registered on 14 December 2020
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Affiliation(s)
- Dagmar-C Fischer
- Department of Pediatrics, Rostock University Medical Center, Ernst-Heydemann-Str. 8, 18057, Rostock, Germany.
| | - Axel Sckell
- Department of Traumatology, Hand and Reconstructive Surgery, Rostock University Medical Center, Rostock, Germany
| | - Angelina Garkisch
- Department of Traumatology, Hand and Reconstructive Surgery, Rostock University Medical Center, Rostock, Germany
| | - Klaus Dresing
- Department of Trauma Surgery, Orthopaedics and Plastic Surgery, University Medicine Göttingen, Georg-August-University, Göttingen, Germany
| | | | - Luzia Valentini
- Department of Agriculture and Food Sciences, Neubrandenburg Institute for Evidence-Based Dietetics (NIED), University of Applied Sciences Neubrandenburg, Neubrandenburg, Germany
| | - Thomas Mittlmeier
- Department of Traumatology, Hand and Reconstructive Surgery, Rostock University Medical Center, Rostock, Germany
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Toepfer ET, Rott J, Bartosova M, Kolevica A, Machuca-Gayet I, Heuser A, Rabe M, Shroff R, Bacchetta J, Zarogiannis SG, Eisenhauer A, Schmitt CP. Calcium isotope fractionation by osteoblasts and osteoclasts, across endothelial and epithelial cell barriers, and with binding to proteins. Am J Physiol Regul Integr Comp Physiol 2021; 321:R29-R40. [PMID: 33978493 DOI: 10.1152/ajpregu.00334.2020] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [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: 11/22/2022]
Abstract
Timely and accurate diagnosis of osteoporosis is essential for adequate therapy. Calcium isotope ratio (δ44/42Ca) determination has been suggested as a sensitive, noninvasive, and radiation-free biomarker for the diagnosis of osteoporosis, reflecting bone calcium balance. The quantitative diagnostic is based on the calculation of the δ44/42Ca difference between blood, urine, and bone. The underlying cellular processes, however, have not been studied systematically. We quantified calcium transport and δ44/42Ca fractionation during in vitro bone formation and resorption by osteoblasts and osteoclasts and across renal proximal tubular epithelial cells (HK-2), human vein umbilical endothelial cells (HUVECs), and enterocytes (Caco-2) in transwell systems and determined transepithelial electrical resistance characteristics. δ44/42Ca fractionation was furthermore quantified with calcium binding to albumin and collagen. Calcified matrix formed by osteoblasts was isotopically lighter than culture medium by -0.27 ± 0.03‰ within 5 days, while a consistent effect of activated osteoclasts on δ44/42Ca could not be demonstrated. A transient increase in δ44/42Ca in the apical compartment by 0.26‰ occured across HK-2 cells, while δ44/42Ca fractionation was small across the HUVEC barrier and absent with Caco-2 enterocytes, and with binding of calcium to albumin and collagen. In conclusion, δ44/42Ca fractionation follows similar universal principles as during inorganic mineral precipitation; osteoblast activity results in δ44/42Ca fractionation. δ44/42Ca fractionation also occurs across the proximal tubular cell barrier and needs to be considered for in vivo bone mineralization modeling. In contrast, the effect of calcium transport across endothelial and enterocyte barriers on blood δ44/42Ca should be low and is absent with physiochemical binding of calcium to proteins.
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Affiliation(s)
- Eva Teresa Toepfer
- Center for Pediatric and Adolescent Medicine, University Hospital Heidelberg, Heidelberg, Germany
| | - Jeremy Rott
- Center for Pediatric and Adolescent Medicine, University Hospital Heidelberg, Heidelberg, Germany
| | - Maria Bartosova
- Center for Pediatric and Adolescent Medicine, University Hospital Heidelberg, Heidelberg, Germany
| | - Ana Kolevica
- GEOMAR, Helmholtz Center for Ocean Research Kiel, Kiel, Germany
| | | | | | - Michael Rabe
- Center for Pediatric and Adolescent Medicine, University Hospital Heidelberg, Heidelberg, Germany
| | - Rukshana Shroff
- Renal Unit, University College of London Great Ormond Street Hospital for Children National Health Service Foundation Trust and Institute of Child Health, London, United Kingdom
| | | | - Sotirios G Zarogiannis
- Center for Pediatric and Adolescent Medicine, University Hospital Heidelberg, Heidelberg, Germany
| | | | - Claus Peter Schmitt
- Center for Pediatric and Adolescent Medicine, University Hospital Heidelberg, Heidelberg, Germany
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Paytan A, Griffith EM, Eisenhauer A, Hain MP, Wallmann K, Ridgwell A. A 35-million-year record of seawater stable Sr isotopes reveals a fluctuating global carbon cycle. Science 2021; 371:1346-1350. [PMID: 33766882 DOI: 10.1126/science.aaz9266] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2019] [Accepted: 02/17/2021] [Indexed: 11/02/2022]
Abstract
Changes in the concentration and isotopic composition of the major constituents in seawater reflect changes in their sources and sinks. Because many of the processes controlling these sources and sinks are tied to the cycling of carbon, such records can provide insights into what drives past changes in atmospheric carbon dioxide and climate. Here, we present a stable strontium (Sr) isotope record derived from pelagic marine barite. Our δ88/86Sr record exhibits a complex pattern, first declining between 35 and 15 million years ago (Ma), then increasing from 15 to 5 Ma, before declining again from ~5 Ma to the present. Numerical modeling reveals that the associated fluctuations in seawater Sr concentrations are about ±25% relative to present-day seawater. We interpret the δ88/86Sr data as reflecting changes in the mineralogy and burial location of biogenic carbonates.
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Affiliation(s)
- Adina Paytan
- Institute of Marine Science, University of California Santa Cruz, Santa Cruz, CA 95064, USA.
| | | | - Anton Eisenhauer
- GEOMAR Helmholtz Centre for Ocean Research Kiel, 24148 Kiel, Germany
| | - Mathis P Hain
- Institute of Marine Science, University of California Santa Cruz, Santa Cruz, CA 95064, USA
| | - Klaus Wallmann
- GEOMAR Helmholtz Centre for Ocean Research Kiel, 24148 Kiel, Germany
| | - Andrew Ridgwell
- Department of Earth Sciences and Planetary Sciences, University of California Riverside, Riverside, CA 92521, USA
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11
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Shroff R, Fewtrell M, Heuser A, Kolevica A, Lalayiannis A, McAlister L, Silva S, Goodman N, Schmitt CP, Biassoni L, Rahn A, Fischer DC, Eisenhauer A. Naturally Occurring Stable Calcium Isotope Ratios in Body Compartments Provide a Novel Biomarker of Bone Mineral Balance in Children and Young Adults. J Bone Miner Res 2021; 36:133-142. [PMID: 32786145 DOI: 10.1002/jbmr.4158] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/14/2020] [Revised: 07/29/2020] [Accepted: 08/02/2020] [Indexed: 12/16/2022]
Abstract
Serum calcium (Ca), bone biomarkers, and radiological imaging do not allow accurate evaluation of bone mineral balance (BMB), a key determinant of bone mineral density (BMD) and fracture risk. We studied naturally occurring stable (non-radioactive) Ca isotopes in different body pools as a potential biomarker of BMB. 42 Ca and 44 Ca are absorbed from our diet and sequestered into different body compartments following kinetic principles of isotope fractionation; isotopically light 42 Ca is preferentially incorporated into bone, whereas heavier 44 Ca preferentially remains in blood and is excreted in urine and feces. Their ratio (δ44/42 Ca) in serum and urine increases during bone formation and decreases with bone resorption. In 117 healthy participants, we measured Ca isotopes, biomarkers, and BMD by dual-energy X-ray absorptiometry (DXA) and tibial peripheral quantitative CT (pQCT). 44 Ca and 42 Ca were measured by multi-collector ionization-coupled plasma mass-spectrometry in serum, urine, and feces. The relationship between bone Ca gain and loss was calculated using a compartment model. δ44/42 Caserum and δ44/42 Caurine were higher in children (n = 66, median age 13 years) compared with adults (n = 51, median age 28 years; p < 0.0001 and p = 0.008, respectively). δ44/42 Caserum increased with height in boys (p < 0.001, R2 = 0.65) and was greatest at Tanner stage 4. δ44/42 Caserum correlated positively with biomarkers of bone formation (25-hydroxyvitaminD [p < 0.0001, R2 = 0.37] and alkaline phosphatase [p = 0.009, R2 = 0.18]) and negatively with bone resorption marker parathyroid hormone (PTH; p = 0.03, R2 = 0.13). δ44/42 Caserum strongly positively correlated with tibial cortical BMD Z-score (n = 62; p < 0.001, R2 = 0.39) but not DXA. Independent predictors of tibial cortical BMD Z-score were δ44/42 Caserum (p = 0.004, β = 0.37), 25-hydroxyvitaminD (p = 0.04, β = 0.19) and PTH (p = 0.03, β = -0.13), together predicting 76% of variability. In conclusion, naturally occurring Ca isotope ratios in different body compartments may provide a novel, non-invasive method of assessing bone mineralization. Defining an accurate biomarker of BMB could form the basis of future studies investigating Ca dynamics in disease states and the impact of treatments that affect bone homeostasis. © 2020 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).
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Affiliation(s)
- Rukshana Shroff
- Renal Unit, UCL Great Ormond Street Hospital for Children NHS Foundation Trust and Institute of Child Health, London, UK
| | - Mary Fewtrell
- Radiology Department, UCL Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK.,Childhood Nutrition Research Centre, UCL Great Ormond Street Institute of Child Health, London, UK
| | | | - Ana Kolevica
- GEOMAR Helmholtz Centre for Ocean Research Kiel, Kiel, Germany
| | - Alexander Lalayiannis
- Renal Unit, UCL Great Ormond Street Hospital for Children NHS Foundation Trust and Institute of Child Health, London, UK
| | - Louise McAlister
- Dietetics Department, UCL Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK
| | - Selmy Silva
- Renal Unit, UCL Great Ormond Street Hospital for Children NHS Foundation Trust and Institute of Child Health, London, UK
| | - Nadine Goodman
- Renal Unit, UCL Great Ormond Street Hospital for Children NHS Foundation Trust and Institute of Child Health, London, UK
| | - Claus P Schmitt
- Center for Pediatric and Adolescent Medicine, University of Heidelberg, Heidelberg, Germany
| | - Lorenzo Biassoni
- Radiology Department, UCL Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK
| | - Anja Rahn
- Department of Pediatrics, Rostock University Medical Centre, Rostock, Germany
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12
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Khalil R, Antonio L, Laurent MR, David K, Kim NR, Evenepoel P, Eisenhauer A, Heuser A, Cavalier E, Khosla S, Claessens F, Vanderschueren D, Decallonne B. Early effects of androgen deprivation on bone and mineral homeostasis in adult men: a prospective cohort study. Eur J Endocrinol 2020; 183:181-189. [PMID: 32454455 DOI: 10.1530/eje-20-0348] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [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] [Received: 04/10/2020] [Accepted: 05/26/2020] [Indexed: 11/08/2022]
Abstract
OBJECTIVE Long-term androgen deprivation therapy (ADT) negatively influences bone. The short-term effects on bone and mineral homeostasis are less known. Therefore, we aimed to investigate the early effects of ADT on calcium/phosphate homeostasis and bone turnover. DESIGN Prospective cohort study. METHODS Eugonadal adult, male sex offenders, who were referred for ADT to the endocrine outpatient clinic, received cyproterone acetate. Changes in blood markers of calcium/phosphate homeostasis and bone turnover between baseline and first follow-up visit were studied. RESULTS Of 26 screened patients, 17 were included. The median age was 44 (range 20-75) years. The median time interval between baseline and first follow-up was 13 (6-27) weeks. Compared to baseline, an 81% decrease was observed for median total testosterone (to 3.4 nmol/L (0.4-12.2); P < 0.0001) and free testosterone (to 0.06 nmol/L (0.01-0.18); P < 0.0001). Median total estradiol decreased by 71% (to 17.6 pmol/L (4.7-35.6); P < 0.0001). Increased serum calcium (P < 0.0001) and phosphate (P = 0.0016) was observed, paralleled by decreased PTH (P = 0.0156) and 1,25-dihydroxyvitamin D3 (P = 0.0134). The stable calcium isotope ratio (δ44/42Ca) decreased (P = 0.0458), indicating net calcium loss from bone. Bone-specific alkaline phosphatase and osteocalcin decreased (P < 0.0001 and P = 0.0056, respectively), periostin tended to decrease (P = 0.0500), whereas sclerostin increased (P < 0.0001), indicating suppressed bone formation. Serum bone resorption markers (TRAP, CTX) were unaltered. CONCLUSIONS In adult men, calcium release from the skeleton occurs early following sex steroid deprivation, reflecting early bone resorption. The increase of sclerostin and reduction of bone formation markers, without changes in resorption markers, suggests a dominant negative effect on bone formation in the acute phase.
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Affiliation(s)
- Rougin Khalil
- Clinical and Experimental Endocrinology, Department of Chronic Diseases, Metabolism and Aging, KU Leuven, Leuven, Belgium
| | - Leen Antonio
- Clinical and Experimental Endocrinology, Department of Chronic Diseases, Metabolism and Aging, KU Leuven, Leuven, Belgium
| | - Michaël R Laurent
- Center for Metabolic Bone Diseases, Geriatrics Department, University Hospitals Leuven, Leuven, Belgium
| | - Karel David
- Clinical and Experimental Endocrinology, Department of Chronic Diseases, Metabolism and Aging, KU Leuven, Leuven, Belgium
| | - Na Ri Kim
- Clinical and Experimental Endocrinology, Department of Chronic Diseases, Metabolism and Aging, KU Leuven, Leuven, Belgium
| | - Pieter Evenepoel
- Nephrology and Renal Transplantation Research Group, Department of Microbiology, Immunology and Transplantation, KU Leuven, Leuven, Belgium
| | | | | | - Etienne Cavalier
- Department of Clinical Chemistry, University of Liège (ULg CHU), Liège, Belgium
| | - Sundeep Khosla
- Kogod Center on Aging and Division of Endocrinology and Metabolism, Mayo Clinic College of Medicine and Science, Rochester, Minnesota, USA
| | - Frank Claessens
- Molecular Endocrinology Laboratory, Department of Cellular and Molecular Medicine, KU Leuven, Leuven, Belgium
| | - Dirk Vanderschueren
- Clinical and Experimental Endocrinology, Department of Chronic Diseases, Metabolism and Aging, KU Leuven, Leuven, Belgium
| | - Brigitte Decallonne
- Clinical and Experimental Endocrinology, Department of Chronic Diseases, Metabolism and Aging, KU Leuven, Leuven, Belgium
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13
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Shroff R, Heuser A, Lalayiannis A, Karabay Bayazit A, Jankauskiene A, BACCHETTA JUSTINE, Askiti V, Schmitt C, Mitsioni A, Crabtree N, Fewtrell M, Biassoni L, Fischer DC, Eisenhauer A. MO055STABLE CALCIUM ISOTOPES: A NOVEL BIOMARKER OF BONE MINERAL CONTENT IN PATIENTS WITH CHRONIC KIDNEY DISEASE. Nephrol Dial Transplant 2020. [DOI: 10.1093/ndt/gfaa140.mo055] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Abstract
Background and Aims
In CKD dysregulated calcium (Ca) homeostasis is common and causally associated with reduced bone mineral density (BMD) and vascular calcification. Currently available radiological measures and biomarkers do not allow accurate evaluation of BMD.
The aim of our study was to determine the sensitivity and specificity of stable Ca isotopes in determining bone mineral content.
Method
We measured stable Ca isotopes 44Ca and 42Ca by plasma-ionization mass-spectrometry in blood and urine. The relationship between bone Ca gain and loss is calculated using a compartment model based on Ca kinetics, and expressed as δ44/42Ca. Ca absorption from bones increases δ44/42CaBlood and δ44/42CaUrine, and resorption decreases these fractions.
104 children in CKD4-5 and on dialysis (CKD4-5D), 40 matched controls and 100 adults underwent Ca isotope measurement, bone biomarkers, dual energy x-ray absorptiometry (DXA) and tibial peripheral quantitative CT scan (pQCT), an accurate measure of cortical BMD.
Results
In healthy children the δ44/42CaBlood and δ44/42CaUrine were higher than in adults (p<0.0001), reflecting avid Ca uptake during bone formation. Since urinary Ca excretion is impaired in CKD, δ44/42CaBlood was higher and δ44/42CaUrine lower in children with CKD4-5D compared to controls (p<0.001 for both); Figure 1.
In CKD2-5D δ44/42CaBlood positively correlated with cholecalciferol (p=0.01) and alfacalcidol (p=0.002) doses, implying increased bone Ca uptake when Ca bioavailability is increased. δ44/42CaBlood positively correlated with biomarkers of bone formation (alkaline phosphatase, p=0.05) and negatively with bone resorption markers (PTH, p=0.013; TRAP5b, p<0.001 and CTX, p=0.006). δ44/42CaBlood positively correlated with tibial cortical BMD-Z-score (p=0.006, R2=0.39), and DXA hip BMD-Z-score (p=0.02). On multivariable linear regression analysis significant and independent predictors of tibial cortical BMD-Z-score were δ44/42CaBlood (β=0.68, p=0.006) and PTH (β-0.39, p=0.04), together predicting 67% of the variability in BMD.
Conclusion
Ca isotope ratios provide a novel, non-invasive method of assessing bone mineralization. Further studies are in progress to define optimal levels of δ44/42CaBlood that can guide safe and effective treatment to prevent Ca deficiency or overload.
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Affiliation(s)
- Rukshana Shroff
- Great Ormond Street Hospital for Children and UCL Institute for Child Health, London, United Kingdom
| | - Alex Heuser
- Geomar Helmholtz Centre for Ocean Research Kiel, Kiel, Germany
| | - Alex Lalayiannis
- Great Ormond Street Hospital for Children and UCL Institute for Child Health, London, United Kingdom
| | | | | | - JUSTINE BACCHETTA
- Hôpital Femme Mère Enfant, Hospices Civils de Lyon, Bron, Lyon, France
| | | | - Claus Schmitt
- Center for Pediatrics and Adolescent Medicine, Heidelberg, Germany
| | | | - Nicola Crabtree
- Birmingham Women’s and Children’s NHS Foundation Trust, Birmingham, United Kingdom
| | - Mary Fewtrell
- Great Ormond Street Hospital for Children and UCL Institute for Child Health, London, United Kingdom
| | - Lorenzo Biassoni
- Great Ormond Street Hospital for Children and UCL Institute for Child Health, London, United Kingdom
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14
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Huang H, Gutjahr M, Eisenhauer A, Kuhn G. No detectable Weddell Sea Antarctic Bottom Water export during the Last and Penultimate Glacial Maximum. Nat Commun 2020; 11:424. [PMID: 31969564 PMCID: PMC6976697 DOI: 10.1038/s41467-020-14302-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [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: 04/15/2019] [Accepted: 12/18/2019] [Indexed: 11/30/2022] Open
Abstract
Weddell Sea-derived Antarctic Bottom Water (AABW) is one of the most important deep water masses in the Southern Hemisphere occupying large portions of the deep Southern Ocean (SO) today. While substantial changes in SO-overturning circulation were previously suggested, the state of Weddell Sea AABW export during glacial climates remains poorly understood. Here we report seawater-derived Nd and Pb isotope records that provide evidence for the absence of Weddell Sea-derived AABW in the Atlantic sector of the SO during the last two glacial maxima. Increasing delivery of Antarctic Pb to regions outside the Weddell Sea traced SO frontal displacements during both glacial terminations. The export of Weddell Sea-derived AABW resumed late during glacial terminations, coinciding with the last major atmospheric CO2 rise in the transition to the Holocene and the Eemian. Our new records lend strong support for a previously inferred AABW overturning stagnation event during the peak Eemian interglacial. The Southern Ocean plays a key role in glacial-interglacial transitions and today, Weddell Sea derived Antarctic Bottom Water is one of the most important deep water masses. New records show that in contrast to today, no Weddell Sea water was exported during the last two glacial maxima, providing new insights towards the condition of Antarctic Bottom Water formation in extreme climate states.
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Affiliation(s)
- Huang Huang
- GEOMAR Helmholtz Centre for Ocean Research Kiel, Wischhofstraße 1-3, 24148, Kiel, Germany.
| | - Marcus Gutjahr
- GEOMAR Helmholtz Centre for Ocean Research Kiel, Wischhofstraße 1-3, 24148, Kiel, Germany
| | - Anton Eisenhauer
- GEOMAR Helmholtz Centre for Ocean Research Kiel, Wischhofstraße 1-3, 24148, Kiel, Germany
| | - Gerhard Kuhn
- Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung, Am Alten Hafen 26, 27568, Bremerhaven, Germany
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15
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Simonet Roda M, Ziegler A, Griesshaber E, Yin X, Rupp U, Greiner M, Henkel D, Häussermann V, Eisenhauer A, Laudien J, Schmahl WW. Terebratulide brachiopod shell biomineralization by mantle epithelial cells. J Struct Biol 2019; 207:136-157. [PMID: 31071428 DOI: 10.1016/j.jsb.2019.05.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [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: 12/20/2018] [Revised: 05/02/2019] [Accepted: 05/04/2019] [Indexed: 11/16/2022]
Abstract
To understand mineral transport pathways for shell secretion and to assess differences in cellular activity during mineralization, we imaged with TEM and FE-SEM ultrastructural characteristics of outer mantle epithelium (OME) cells. Imaging was carried out on Magellania venosa shells embedded/etched, chemically fixed/decalcified and high-pressure frozen/freeze-substituted samples from the commissure, central shell portions and from puncta. Imaging results are complemented with morphometric evaluations of volume fractions of membrane-bound organelles. At the commissure the OME consists of several layers of cells. These cells form oblique extensions that, in cross-section, are round below the primary layer and flat underneath fibres. At the commissure the OME is multi-cell layered, in central shell regions it is single-cell layered. When actively secreting shell carbonate extrapallial space is lacking, because OME cells are in direct contact with the calcite of the forming fibres. Upon termination of secretion, OME cells attach via apical hemidesmosomes to extracellular matrix membranes that line the proximal surface of fibres. At the commissure volume fractions for vesicles, mitochondria and lysosomes are higher relative to single-cell layered regions, whereas for endoplasmic-reticulum and Golgi apparatus there is no difference. FE-SEM, TEM imaging reveals the lack of extrapallial space between OME cells and developing fibres. In addition, there is no indication for an amorphous precursor within fibres when these are in active secretion mode. Accordingly, our results do not support transport of minerals by vesicles from cells to sites of mineralization, rather by transfer of carbonate ions via transport mechanisms associated with OME cell membranes.
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Affiliation(s)
- M Simonet Roda
- Department of Earth and Environmental Sciences, LMU, 80333 München, Germany.
| | - A Ziegler
- Central Facility for Electron Microscopy, University of Ulm, 89069 Ulm, Germany
| | - E Griesshaber
- Department of Earth and Environmental Sciences, LMU, 80333 München, Germany
| | - X Yin
- Department of Earth and Environmental Sciences, LMU, 80333 München, Germany
| | - U Rupp
- Central Facility for Electron Microscopy, University of Ulm, 89069 Ulm, Germany
| | - M Greiner
- Department of Earth and Environmental Sciences, LMU, 80333 München, Germany
| | - D Henkel
- Marine Biogeochemistry/Marine Systems, GEOMAR Helmholtz Centre for Ocean Research, 24148 Kiel, Germany
| | - V Häussermann
- Pontificia Universidad Católica de Valparaíso, Facultad de Recursos Naturales, Escuela de Ciencias del Mar, Avda. Brasil, 2950 Valparaíso, Chile; Huinay Scientific Field Station, Puerto Montt, Chile
| | - A Eisenhauer
- Marine Biogeochemistry/Marine Systems, GEOMAR Helmholtz Centre for Ocean Research, 24148 Kiel, Germany
| | - J Laudien
- Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung, 27568 Bremerhaven, Germany
| | - W W Schmahl
- Department of Earth and Environmental Sciences, LMU, 80333 München, Germany
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16
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Eisenhauer A, Müller M, Heuser A, Kolevica A, Glüer CC, Both M, Laue C, Hehn UV, Kloth S, Shroff R, Schrezenmeir J. Calcium isotope ratios in blood and urine: A new biomarker for the diagnosis of osteoporosis. Bone Rep 2019; 10:100200. [PMID: 30997369 PMCID: PMC6453776 DOI: 10.1016/j.bonr.2019.100200] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/02/2019] [Accepted: 03/10/2019] [Indexed: 11/30/2022] Open
Abstract
We assessed the potential of Calcium (Ca) isotope fractionation measurements in blood (δ44/42CaBlood) and urine (δ44/42CaUrine) as a new biomarker for the diagnosis of osteoporosis. One hundred post-menopausal women aged 50 to 75 years underwent dual-energy X-ray absorptiometry (DXA), the gold standard for determination of bone mineral density. After exclusion of women with kidney failure and vitamin D deficiency (<25 nmol/l) 80 women remained in the study. Of these women 14 fulfilled the standard diagnostic criteria for osteoporosis based on DXA. Both the δ44/42CaBlood (p < 0.001) and δ44/42CaUrine (p = 0.004) values were significantly different in women with osteoporosis (δ44/42CaBlood: −0.99 ± 0.10‰, δ 44/42CaUrine: +0.10 ± 0.21‰, (Mean ± one standard deviation (SD), n = 14)) from those without osteoporosis (δ44/42CaBlood: −0.84 ± 0.14‰, δ44/42CaUrine: +0.35 ± 0.33‰, (SD), n = 66). This corresponded to the average Ca concentrations in morning spot urine samples ([Ca]Urine) which were higher (p = 0.041) in those women suffering from osteoporosis ([Ca]Urine-Osteoporosis: 2.58 ± 1.26 mmol/l, (SD), n = 14) than in the control group ([Ca]Urine-Control: 1.96 ± 1.39 mmol/l, (SD), n = 66). However, blood Ca concentrations ([Ca]Blood) were statistically indistinguishable between groups ([Ca]Blood, control: 2.39 ± 0.10 mmol/l (SD), n = 66); osteoporosis group: 2.43 ± 0.10 mmol/l (SD, n = 14) and were also not correlated to their corresponding Ca isotope compositions. The δ44/42CaBlood and δ44/42CaUrine values correlated significantly (p = 0.004 to p = 0.031) with their corresponding DXA data indicating that both Ca isotope ratios are biomarkers for osteoporosis. Furthermore, Ca isotope ratios were significantly correlated to other clinical parameters ([Ca]Urine, ([Ca]Urine/Creatinine)) and biomarkers (CRP, CTX/P1NP) associated with bone mineralization and demineralization. From regression analysis it can be shown that the δ44/42CaBlood values are the best biomarker for osteoporosis and that no other clinical parameters need to be taken into account in order to improve diagnosis. Cut-off values for discrimination of subjects suffering from osteoporosis were − 0.85‰ and 0.16‰ for δ44/42CaBlood and δ44/42CaUrine, respectively. Corresponding sensitivities were 100% for δ44/42CaBlood and ~79% for δ44/42CaUrine. Apparent specificities were ~55% for δ44/42CaBlood and ~71%. The apparent discrepancy in the number of diagnosed cases is reconciled by the different methodological approaches to diagnose osteoporosis. DXA reflects the bone mass density (BMD) of selected bones only (femur and spine) whereas the Ca isotope biomarker reflects bone Ca loss of the whole skeleton. In addition, the close correlation between Ca isotopes and biomarkers of bone demineralization suggest that early changes in bone demineralization are detected by Ca isotope values, long before radiological changes in BMD can manifest on DXA. Further studies are required to independently confirm that Ca isotope measurement provide a sensitive, non-invasive and radiation-free method for the diagnosis of osteoporosis.
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Affiliation(s)
- A Eisenhauer
- GEOMAR Helmholtz Centre for Ocean Research Kiel, 24148 Kiel, Wischhofstr.1-3, Germany.,OSTEOLABS GmbH, c/o GEOMAR Helmholtz Centre for Ocean Research Kiel, 24148 Kiel, Wischhofstr.1-3, Germany
| | - M Müller
- University Medical Center Schleswig-Holstein (UKSH), Arnold-Heller-Str. 3, 24105 Kiel, Germany.,OSTEOLABS GmbH, c/o GEOMAR Helmholtz Centre for Ocean Research Kiel, 24148 Kiel, Wischhofstr.1-3, Germany
| | - A Heuser
- GEOMAR Helmholtz Centre for Ocean Research Kiel, 24148 Kiel, Wischhofstr.1-3, Germany.,OSTEOLABS GmbH, c/o GEOMAR Helmholtz Centre for Ocean Research Kiel, 24148 Kiel, Wischhofstr.1-3, Germany
| | - A Kolevica
- GEOMAR Helmholtz Centre for Ocean Research Kiel, 24148 Kiel, Wischhofstr.1-3, Germany.,OSTEOLABS GmbH, c/o GEOMAR Helmholtz Centre for Ocean Research Kiel, 24148 Kiel, Wischhofstr.1-3, Germany
| | - C-C Glüer
- Sektion Biomedizinische Bildgebung, Klinik für Radiologie und Neuroradiologie, Am Botanischen Garten 14, 24118 Kiel, Germany
| | - M Both
- Klinik für Neuroradiologie und Radiologie, (UKSH), Arnold-Heller-Str. 3, 24105 Kiel, Germany
| | - C Laue
- Clinical Research Center Kiel GmbH, Schauenburgerstraße 116, 24118 Kiel, Germany
| | - U V Hehn
- Medistat, GmbH, Kieler Straße 15, 24119 Kronshagen, Germany
| | - S Kloth
- OSTEOLABS GmbH, c/o GEOMAR Helmholtz Centre for Ocean Research Kiel, 24148 Kiel, Wischhofstr.1-3, Germany
| | - R Shroff
- Great Ormond Street Hospital for Children NHS Foundation Trust, London WC1N 3JH, United Kingdom of Great Britain and Northern Ireland
| | - J Schrezenmeir
- Clinical Research Center Kiel GmbH, Schauenburgerstraße 116, 24118 Kiel, Germany
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17
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Taubner I, Hu MY, Eisenhauer A, Bleich M. Electrophysiological evidence for light-activated cation transport in calcifying corals. Proc Biol Sci 2019; 286:20182444. [PMID: 30963934 PMCID: PMC6408601 DOI: 10.1098/rspb.2018.2444] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [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: 10/30/2018] [Accepted: 01/23/2019] [Indexed: 12/17/2022] Open
Abstract
Light has been demonstrated to enhance calcification rates in hermatypic coral species. To date, it remains unresolved whether calcifying epithelia change their ion transport activity during illumination, and whether such a process is mediated by the endosymbiotic algae or can be controlled by the coral host itself. Using a modified Ussing chamber in combination with H+ sensitive microelectrode measurements, the present work demonstrates that light triggers the generation of a skeleton positive potential of up to 0.9 mV in the hermatypic coral Stylophora pistillata. This potential is generated by a net flux of cations towards the skeleton and reaches its maximum at blue (450 nm) light. The effects of pharmacological inhibitors targeting photosynthesis 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU) and anion transport 4,4'-diisothiocyano-2,2'-stilbenedisulfonic acid (DIDS) were investigated by pH microelectrode measurements in coral tissues demonstrating a rapid decrease in tissue pH under illumination. However, these inhibitors showed no effect on the electrophysiological light response of the coral host. By contrast, metabolic inhibition by cyanide and deoxyglucose reversibly inhibited the light-induced cation flux towards the skeleton. These results suggest that ion transport across coral epithelia is directly triggered by blue light, independent of photosynthetic activity of algal endosymbionts. Measurements of this very specific and quantifiable physiological response can provide parameters to identify photoreception mechanisms and will help to broaden our understanding of the mechanistic link between light stimulation and epithelial ion transport, potentially relevant for calcification in hermatypic corals.
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Affiliation(s)
- Isabelle Taubner
- Christian-Albrechts-Universität, Institute of Physiology, Kiel, Germany
- GEOMAR Helmholtz Centre for Ocean Research Kiel, Kiel, Germany
| | - Marian Y. Hu
- Christian-Albrechts-Universität, Institute of Physiology, Kiel, Germany
| | | | - Markus Bleich
- Christian-Albrechts-Universität, Institute of Physiology, Kiel, Germany
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18
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Simonet Roda M, Griesshaber E, Ziegler A, Rupp U, Yin X, Henkel D, Häussermann V, Laudien J, Brand U, Eisenhauer A, Checa AG, Schmahl WW. Calcite fibre formation in modern brachiopod shells. Sci Rep 2019; 9:598. [PMID: 30679565 PMCID: PMC6345923 DOI: 10.1038/s41598-018-36959-z] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [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: 10/12/2018] [Accepted: 11/19/2018] [Indexed: 11/09/2022] Open
Abstract
The fibrous calcite layer of modern brachiopod shells is a hybrid composite material and forms a substantial part of the hard tissue. We investigated how cells of the outer mantle epithelium (OME) secrete calcite material and generate the characteristic fibre morphology and composite microstructure of the shell. We employed AFM, FE-SEM, and TEM imaging of embedded/etched, chemically fixed/decalcified and high-pressure frozen/freeze substituted samples. Calcite fibres are secreted by outer mantle epithelium (OME) cells. Biometric analysis of TEM micrographs indicates that about 50% of these cells are attached via hemidesmosomes to an extracellular organic membrane present at the proximal, convex surface of the fibres. At these sites, mineral secretion is not active. Instead, ion transport from OME cells to developing fibres occurs at regions of closest contact between cells and fibres, however only at sites where the extracellular membrane at the proximal fibre surface is not developed yet. Fibre formation requires the cooperation of several adjacent OME cells. It is a spatially and temporally changing process comprising of detachment of OME cells from the extracellular organic membrane, mineral secretion at detachment sites, termination of secretion with formation of the extracellular organic membrane, and attachment of cells via hemidesmosomes to this membrane.
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Affiliation(s)
- Maria Simonet Roda
- Department of Earth and Environmental Sciences, LMU, 80333, München, Germany.
| | - Erika Griesshaber
- Department of Earth and Environmental Sciences, LMU, 80333, München, Germany
| | - Andreas Ziegler
- Central Facility for Electron Microscopy, University of Ulm, 89069, Ulm, Germany
| | - Ulrich Rupp
- Central Facility for Electron Microscopy, University of Ulm, 89069, Ulm, Germany
| | - Xiaofei Yin
- Department of Earth and Environmental Sciences, LMU, 80333, München, Germany
| | - Daniela Henkel
- Marine Biogeochemistry/Marine Systems, GEOMAR Helmholtz Centre for Ocean Research, 24148, Kiel, Germany
| | - Vreni Häussermann
- Pontificia Universidad Católica de Valparaíso, Facultad de Recursos Naturales, Escuela de Ciencias del Mar, Avda. Brasil, 2950, Valparaíso, Chile
- Huinay Scientific Field Station, Puerto Montt, Chile
| | - Jürgen Laudien
- Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung, 27568, Bremerhaven, Germany
| | - Uwe Brand
- Department of Earth Sciences, Brock University, 1812 Sir Isaac Brock Way, St. Catharines, Ontario, L2S 3A1, Canada
| | - Anton Eisenhauer
- Marine Biogeochemistry/Marine Systems, GEOMAR Helmholtz Centre for Ocean Research, 24148, Kiel, Germany
| | - Antonio G Checa
- Departamento de Estratigrafía y Paleontología, Facultad de Ciencias Universidad de Granada, 18071, Granada, Spain
- Instituto Andaluz de Ciencias de la Tierra, CSIC-Universidad de Granada, 18100, Armilla, Spain
| | - Wolfgang W Schmahl
- Department of Earth and Environmental Sciences, LMU, 80333, München, Germany
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Müller MN, Krabbenhöft A, Vollstaedt H, Brandini FP, Eisenhauer A. Stable isotope fractionation of strontium in coccolithophore calcite: Influence of temperature and carbonate chemistry. Geobiology 2018; 16:297-306. [PMID: 29431278 DOI: 10.1111/gbi.12276] [Citation(s) in RCA: 3] [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: 08/05/2017] [Accepted: 01/17/2018] [Indexed: 06/08/2023]
Abstract
Marine calcifying eukaryotic phytoplankton (coccolithophores) is a major contributor to the pelagic production of CaCO3 and plays an important role in the biogeochemical cycles of C, Ca and other divalent cations present in the crystal structure of calcite. The geochemical signature of coccolithophore calcite is used as palaeoproxy to reconstruct past environmental conditions and to understand the underlying physiological mechanisms (vital effects) and precipitation kinetics. Here, we present the stable Sr isotope fractionation between seawater and calcite (Δ88/86 Sr) of laboratory cultured coccolithophores in individual dependence of temperature and seawater carbonate chemistry. Coccolithophores were cultured within a temperature and a pCO2 range from 10 to 25°C and from 175 to 1,240 μatm, respectively. Both environmental drivers induced a significant linear increase in coccolith stable Sr isotope fractionation. The temperature correlation at constant pCO2 for Emiliania huxleyi and Coccolithus braarudii is expressed as Δ88/86 Sr = -7.611 × 10-3 T + 0.0061. The relation of Δ88/86 Sr to pCO2 was tested in Emiliania huxleyi at 10 and 20°C and resulted in Δ88/86 Sr = -5.394 × 10-5 pCO2 - 0.0920 and Δ88/86 Sr = -5.742 × 10-5 pCO2 - 0.1351, respectively. No consistent relationship was found between coccolith Δ88/86 Sr and cellular physiology impeding a direct application of fossil coccolith Δ88/86 Sr as coccolithophore productivity proxy. An overall significant correlation was detected between the elemental distribution coefficient (DSr ) and Δ88/86 Sr similar to inorganic calcite with a physiologically induced offset. Our observations indicate (i) that temperature and pCO2 induce specific effects on coccolith Δ88/86 Sr values and (ii) that strontium elemental ratios and stable isotope fractionation are mainly controlled by precipitation kinetics when embedded into the crystal lattice and subject to vital effects during the transmembrane transport from seawater to the site of calcification. These results provide an important step to develop a coccolith Δ88/86 Sr palaeoproxy complementing the existing toolbox of palaeoceanography.
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Affiliation(s)
- M N Müller
- Department of Oceanography, Federal University of Recife, Cidade Universitária, Recife, PE, Brazil
- Oceanographic Institute at the University of São Paulo, São Paulo, SP, Brazil
| | - A Krabbenhöft
- GEOMAR Helmholtz Centre for Ocean Research Kiel, Kiel, Germany
| | - H Vollstaedt
- Institute of Geological Science, University of Bern, Bern, Switzerland
| | - F P Brandini
- Oceanographic Institute at the University of São Paulo, São Paulo, SP, Brazil
| | - A Eisenhauer
- GEOMAR Helmholtz Centre for Ocean Research Kiel, Kiel, Germany
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20
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Heuser A, Eisenhauer A, Scholz-Ahrens KE, Schrezenmeir J. Biological fractionation of stable Ca isotopes in Göttingen minipigs as a physiological model for Ca homeostasis in humans. Isotopes Environ Health Stud 2016; 52:633-648. [PMID: 26999569 DOI: 10.1080/10256016.2016.1151017] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [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: 07/22/2015] [Accepted: 12/19/2015] [Indexed: 06/05/2023]
Abstract
In order to investigate fractionation of calcium (Ca) isotopes in vertebrates as a diagnostic tool to detect Ca metabolism dysfunction we analyzed the Ca isotopic composition (δ(44/40)Ca = [((44)Ca/(40)Ca)sample/((44)Ca/(40)Ca)reference]-1) of diet, faeces, blood, bones and urine from Göttingen minipigs, an animal model for human physiology. Samples of three groups were investigated: 1. control group (Con), 2. group with glucocorticosteroid induced osteoporosis (GIO) and 3. group with Ca and vitamin D deficiency induced osteomalacia (-CaD). In contrast to Con and GIO whose average δ(44/40)Cafaeces values (0.39 ± 0.13‰ and 0.28 ± 0.08‰, respectively) tend to be lower than their diet (0.47 ± 0.02‰), δ(44/40)Cafaeces of -CaD (-0.27 ± 0.21‰) was significantly lower than their δ(44/40)Cadiet (0.37 ± 0.03‰), but also lower than δ(44/40)Cafaeces of Con and GIO. We suggest that the low δ(44/40)Cafaeces of -CaD might be due to the contribution of isotopically light Ca from gastrointestinal fluids during gut passage. Assuming that this endogenous Ca source is a common physiologic feature, a fractionation during Ca absorption is also required for explaining δ(44/40)Cafaeces of Con and GIO. The δ(44/40)Caurine of all groups are high (>2.0‰) reflecting preferential renal reabsorption of light Ca isotopes. In Göttingen minipigs we found a Ca isotope fractionation between blood and bones (Δ(44/40)Cablood-bone) of 0.68 ± 0.15‰.
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Affiliation(s)
- Alexander Heuser
- a GEOMAR Helmholtz Centre of Ocean Research Kiel , Kiel , Germany
| | - Anton Eisenhauer
- a GEOMAR Helmholtz Centre of Ocean Research Kiel , Kiel , Germany
| | - Katharina E Scholz-Ahrens
- b Department of Physiology and Biochemistry of Nutrition, Max Rubner-Institut, Federal Research Institute of Nutrition and Food , Kiel , Germany
- c Department of Safety and Quality of Milk and Fish Products , Max Rubner-Institut, Federal Research Institute of Nutrition and Food , Kiel , Germany
| | - Jürgen Schrezenmeir
- b Department of Physiology and Biochemistry of Nutrition, Max Rubner-Institut, Federal Research Institute of Nutrition and Food , Kiel , Germany
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21
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Suess E, Torres M, Bohrmann G, Collier R, Rickert D, Goldfinger C, Linke P, Heuser A, Sahling H, Heeschen K, Jung C, Nakamura K, Greinert J, Pfannkuche O, Trehu A, Klinkhammer G, Whiticar M, Eisenhauer A, Teichert B, Elver M. Sea Floor Methane Hydrates at Hydrate Ridge, Cascadia Margin. ACTA ACUST UNITED AC 2013. [DOI: 10.1029/gm124p0087] [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: 03/14/2023]
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22
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Saccon P, Leis A, Marca A, Kaiser J, Campisi L, Böttcher ME, Savarino J, Escher P, Eisenhauer A, Erbland J. Determination of Nitrate Pollution Sources in the Marano Lagoon (Italy) by using a Combined Approach of Hydrochemical and Isotopic Techniques. ACTA ACUST UNITED AC 2013. [DOI: 10.1016/j.proeps.2013.03.019] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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23
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Tang J, Niedermayr A, Köhler SJ, Böhm F, Kısakürek B, Eisenhauer A, Dietzel M. Sr 2+/Ca 2+ and 44Ca/ 40Ca fractionation during inorganic calcite formation: III. Impact of salinity/ionic strength. Geochim Cosmochim Acta 2012; 77:432-443. [PMID: 22347722 PMCID: PMC3280721 DOI: 10.1016/j.gca.2011.10.039] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/12/2011] [Accepted: 10/27/2011] [Indexed: 05/31/2023]
Abstract
In order to apply Sr/Ca and (44)Ca/(40)Ca fractionation during calcium carbonate (CaCO(3)) formation as a proxy to reconstruct paleo-environments, it is essential to evaluate the impact of various environmental factors. In this study, a CO(2) diffusion technique was used to crystallize inorganic calcite from aqueous solutions at different ionic strength/salinity by the addition of NaCl at 25 °C. Results show that the discrimination of Sr(2+) versus Ca(2+) during calcite formation is mainly controlled by precipitation rate (R in μmol/m(2)/h) and is weakly influenced by ionic strength/salinity. In analogy to Sr incorporation, (44)Ca/(40)Ca fractionation during precipitation of calcite is weakly influenced by ionic strength/salinity too. At 25 °C the calcium isotope fractionation between calcite and aqueous calcium ions (Δ(44/40)Ca(calcite-aq) = δ(44/40)Ca(calcite) - δ(44/40)Ca(aq)) correlates inversely to log R values for all experiments. In addition, an inverse relationship between Δ(44/40)Ca(calcite-aq) and log D(Sr), which is independent of temperature, precipitation rate, and aqueous (Sr/Ca)(aq) ratio, is not affected by ionic strength/salinity either. Considering the log D(Sr) and Δ(44/40)Ca(calcite-aq) relationship, Sr/Ca and δ(44/40)Ca(calcite) values of precipitated calcite can be used as an excellent multi-proxy approach to reconstruct environmental conditions (e.g., temperature, precipitation rate) of calcite growth and diagenetic alteration.
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Affiliation(s)
- Jianwu Tang
- Institute of Applied Geosciences, Graz University of Technology, Rechbauerstrasse 12, A-8010 Graz, Austria
| | - Andrea Niedermayr
- Institute of Applied Geosciences, Graz University of Technology, Rechbauerstrasse 12, A-8010 Graz, Austria
| | - Stephan J. Köhler
- Department of Aquatic Sciences and Assessment, P.O. Box 7050, SE-75007 Uppsala, Sweden
| | - Florian Böhm
- Leibniz-Institut für Meereswissenschaften, IFM-GEOMAR, Wischhofstr. 1-3, D-24148 Kiel, Germany
| | - Basak Kısakürek
- Leibniz-Institut für Meereswissenschaften, IFM-GEOMAR, Wischhofstr. 1-3, D-24148 Kiel, Germany
| | - Anton Eisenhauer
- Leibniz-Institut für Meereswissenschaften, IFM-GEOMAR, Wischhofstr. 1-3, D-24148 Kiel, Germany
| | - Martin Dietzel
- Institute of Applied Geosciences, Graz University of Technology, Rechbauerstrasse 12, A-8010 Graz, Austria
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Heuser A, Eisenhauer A. A pilot study on the use of natural calcium isotope (44Ca/40Ca) fractionation in urine as a proxy for the human body calcium balance. Bone 2010; 46:889-96. [PMID: 20004263 DOI: 10.1016/j.bone.2009.11.037] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.1] [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] [Received: 10/14/2009] [Accepted: 11/30/2009] [Indexed: 10/20/2022]
Abstract
We explored the possibility of using natural calcium (Ca) isotope variations in the urine (delta(44/40)Ca(urine)) as a proxy for the Ca balance in the human body. We chose two test persons extremely different in their health status, gender and age (4-year-old healthy boy and a 60-year-old woman known to suffer from osteoporosis). During a 5 day interval the Ca isotope composition of the individual diet (delta(44/40)Ca(diet)) was monitored for both test persons to be in general agreement to the Ca isotope composition of the normal western European diet ( approximately -1.02+/-0.1 per thousand). However, measurements showed that (1) delta(44/40)Ca(urine) of both test persons are approximately 1.37 and approximately 2.49 per thousand, respectively, heavier than delta(44/40)Ca(diet) and that (2) the delta(44/40)Ca(urine-boy) is approximately 1.1 per thousand heavier when compared to the value of the woman. The individual offset between diet and test persons is interpreted to reflect individual Ca reabsorption rates in the kidneys being the result of Rayleigh type Ca isotope fractionation related to the partitioning of Ca between the glomerular filtrate and filtered residue. The relative difference between delta(44/40)Ca(urine-boy) and delta(44/40)Ca(urine-woman) of approximately 1.1 per thousand may reflect individual differences in the balance of bone mineralization and demineralization processes related to age, gender and health status. By arbitrarily defining an equilibrium value for Delta(44/40)Ca(diet-urine) of -1.93 per thousand being the arithmetic mean of delta(44/40)Ca(urine) for both test persons the measured delta(44/40)Ca(urine) values may be applied to model the individual bone mineralization and demineralization processes in a qualitative way. Note, second order influences of intestinal Ca absorption during sequestration of Ca between intestine and blood have to be subject of further studies.
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Affiliation(s)
- Alexander Heuser
- Leibniz-Institut für Meereswissenschaften, IFM-GEOMAR, Wischhofstr. 1-3, 24148 Kiel, Germany.
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25
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MacDonald IR, Bohrmann G, Escobar E, Abegg F, Blanchon P, Blinova V, Brückmann W, Drews M, Eisenhauer A, Han X, Heeschen K, Meier F, Mortera C, Naehr T, Orcutt B, Bernard B, Brooks J, de Faragó M. Asphalt volcanism and chemosynthetic life in the Campeche Knolls, Gulf of Mexico. Science 2004; 304:999-1002. [PMID: 15143278 DOI: 10.1126/science.1097154] [Citation(s) in RCA: 117] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
In the Campeche Knolls, in the southern Gulf of Mexico, lava-like flows of solidified asphalt cover more than 1 square kilometer of the rim of a dissected salt dome at a depth of 3000 meters below sea level. Chemosynthetic tubeworms and bivalves colonize the sea floor near the asphalt, which chilled and contracted after discharge. The site also includes oil seeps, gas hydrate deposits, locally anoxic sediments, and slabs of authigenic carbonate. Asphalt volcanism creates a habitat for chemosynthetic life that may be widespread at great depth in the Gulf of Mexico.
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Affiliation(s)
- I R MacDonald
- Physical and Life Sciences Department, Texas A & M University-Corpus Christi, 6300 Ocean Drive, Corpus Christi, TX 78412, USA.
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26
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Abstract
An alpha-spectrometric method for the rapid determination of radium isotopes (223Ra, 224Ra and 226Ra) in environmental samples is presented. Using Empore Radium Rad Disks complete separation of the target radionuclides is achieved. The high selectivity of these Rad Disks allows the straightforward use of 225Ra as yield tracer. Chemical yield is up to 92 +/- 9%. The chemical procedure can be accomplished within 5h. Alpha-sources show energy resolution in the range of typically 26-40 keV (FWHM). Despite minimal thickness of the sources no significant radon (Rn) losses can be observed.
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Affiliation(s)
- Stefan Purkl
- Geomar, Research Center for Marine Geosciences, Wischhofstr 1-3, Kiel D-24148, Germany.
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Abstract
OBJECTIVES To compare stenting of aortic arch vessel obstruction with surgical therapy and to establish recommendations for treatment. BACKGROUND Though surgery has been considered to be the procedure of choice for subclavian and brachiocephalic obstruction, little work has been done to compare it with stenting. METHODS Eighteen patients with symptomatic aortic arch vessel stenosis or occlusion were treated with stenting, followed by periodic clinical follow-up and noninvasive arterial Doppler studies. Data were compared with the results as shown in a systematic review of a published series of surgery and stenting procedures which included comparison of technical success, complications, mortality and patency. RESULTS Primary success in our series was 100% with improvement in mean stenosis from 84+/-11% to 1+/-5% and mean arm systolic blood pressure difference from 44+/-16 mm Hg to 3+/-3 mm Hg. There were no major complications (death, stroke, TIA, stent thrombosis or myocardial infarction). At follow-up (mean 17 months), all patients were asymptomatic with 100% primary patency. Literature review demonstrates equivalent patency and complications in the other published series of stenting. In contrast, there was a similar patency but overall incidence of stroke of 3+/-4% and death of 2+/-2% in the published surgical series. CONCLUSIONS Subclavian or brachiocephalic artery obstruction can be effectively treated by primary stenting or surgery. Comparison of stenting and the surgical experience demonstrates equal effectiveness but fewer complications and suggests that stenting should be considered as first line therapy for subclavian or brachiocephalic obstruction.
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Affiliation(s)
- P Hadjipetrou
- Interventional Cardiovascular Medicine, Lahey Clinic, Medical Center, Burlington, Massachusetts 01805, USA
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Rachold V, Eisenhauer A, Hubberten HW, Hansen B, Meyer H. Sr Isotopic Composition of Suspended Particulate Material (SPM) of East Siberian Rivers: Sediment Transport to the Arctic Ocean. ACTA ACUST UNITED AC 1997. [DOI: 10.2307/1551990] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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30
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Kloner RA, Eisenhauer A. Recombinant tissue-type plasminogen activator: an infarct-sparing effect beyond thrombolysis? J Am Coll Cardiol 1992; 20:226-7. [PMID: 1607529 DOI: 10.1016/0735-1097(92)90163-h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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31
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Matthews R, Clugston R, Eisenhauer A, Dake M, Schatz R, Feinstein E. Balloon expandable stents to treat central venous stenoses in hemodialysis patients. Am J Nephrol 1992; 12:451-6. [PMID: 1292345 DOI: 10.1159/000168497] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Vascular access failure in hemodialysis patients remains a significant problem. The use of thrombolytic agents and balloon angioplasty instead of or in conjunction with surgical revision, has been helpful in increasing the life span of vascular access in these patients. The application of newer endovascular therapies, such as vascular stents, may further improve the salvage rate of hemodialysis access sites. These stents may be particularly valuable in treating stenoses in large central veins. We present 2 cases in which a balloon-expandable Palmaz stent was used to treat a central venous stenosis causing signs of vascular access failure.
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Affiliation(s)
- R Matthews
- Cardiac Catherization and Interventional Laboratory, Hospital of the Good Samaritan, Los Angeles, Calif 90017
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32
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Kloner RA, Alker K, Campbell C, Figures G, Eisenhauer A, Hale S. Does tissue-type plasminogen activator have direct beneficial effects on the myocardium independent of its ability to lyse intracoronary thrombi? Circulation 1989; 79:1125-36. [PMID: 2496937 DOI: 10.1161/01.cir.79.5.1125] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.1] [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: 01/01/2023]
Abstract
Tissue-type plasminogen activator (t-PA) is a widely used thrombolytic agent for treating acute myocardial infarction. Some previous studies suggest that t-PA benefits the heart independently of lysing coronary artery thrombi. The purpose of this study was to determine whether t-PA directly affects infarct size independently of lysing coronary thrombi, affects the no-reflow phenomenon, and exacerbates intramyocardial hemorrhage. We used a canine model of 2 hours of occlusion of the left anterior descending coronary artery followed by 4 hours of reperfusion. t-PA was administered 30 minutes after occlusion and was continued for 2 hours. Myocardial infarct size as a percentage of the risk zone was similar between saline (28 +/- 8%) and t-PA (35 +/- 9%) groups in a low-dose study and between saline (46 +/- 12%) and t-PA (44 +/- 12%) groups in a high-dose study. t-PA did not improve no-reflow. Intramyocardial hemoglobin level within the infarct was similar between saline (16 micrograms/mg) and high-dose t-PA (12 micrograms/mg) groups. The extent of hemorrhage assessed by intramyocardial hemoglobin correlated with infarct size. Histologic evaluation revealed that microscopic hemorrhage was confined to zones of contraction band necrosis. Neutrophil infiltration during early reperfusion was prominent. In conclusion, t-PA did not directly benefit the myocardium or no-reflow. Its effects in patients are likely due to its ability to lyse thrombi. t-PA did not cause infiltration of hemorrhage into noninfarcted tissue. Reperfusion accelerates the inflammatory response after myocardial infarction and results in early, intense neutrophil infiltration.
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Affiliation(s)
- R A Kloner
- Division of Cardiology, Wayne State University, Detroit, Michigan
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Hauser RG, Wimer EA, Timmis GC, Gordon S, Staller B, Klodnycky M, Eisenhauer A, Goren C, Moran JF, Davis AA. Twelve years of clinical experience with lithium pulse generators. Pacing Clin Electrophysiol 1986; 9:1277-81. [PMID: 2432547 DOI: 10.1111/j.1540-8159.1986.tb06708.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The clinical performance of 9,651 lithium pulse generators, which were implanted at our registry hospitals since 1973, was assessed by analysis of actuarial survival data and information obtained at the time of pacemaker failure. Cumulative survival estimates for all units were: 5 years, 94 percent, 7 years, 81 percent, 10 years, 62 percent. Discriminant actuarial analysis revealed no differences between lithium iodine and lithium cupric sulfide longevity. Battery depletion was found in 49.1 percent of 277 units subjected to detailed explant analysis, while 31 percent and 8.7 percent had component and hermetic seal defects, respectively. Of the pulse generators with battery depletion, all but two units exhibited normal end-of-battery life behavior. We conclude that the lithium iodine and lithium cupric sulfide batteries are safe, long-term energy sources; however, the impact of reduced battery size and dual chamber pacing on these performance parameters is unknown.
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