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Kucharczyk P, Albano G, Deisl C, Ho TM, Bargagli M, Anderegg M, Wueest S, Konrad D, Fuster DG. Thiazides Attenuate Insulin Secretion Through Inhibition of Mitochondrial Carbonic Anhydrase 5b in β -Islet Cells in Mice. J Am Soc Nephrol 2023; 34:1179-1190. [PMID: 36927842 PMCID: PMC10356162 DOI: 10.1681/asn.0000000000000122] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [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: 07/28/2022] [Accepted: 02/26/2023] [Indexed: 03/18/2023] Open
Abstract
SIGNIFICANCE STATEMENT Thiazide diuretics (thiazides) are among the most widely prescribed drugs worldwide, but their use is associated with glucose intolerance and new-onset diabetes mellitus. The molecular mechanisms remain elusive. Our study reveals that thiazides attenuate insulin secretion through inhibition of the mitochondrial carbonic anhydrase isoform 5b (CA5b) in pancreatic β cells. We furthermore discovered that pancreatic β cells express only one functional carbonic anhydrase isoform, CA5b, which is critical in replenishing oxaloacetate in the mitochondrial tricarboxylic acid (TCA) cycle (anaplerosis). These findings explain the mechanism for thiazide-induced glucose intolerance and reveal a fundamental role of CA5b in TCA cycle anaplerosis and insulin secretion in β cells. BACKGROUND Thiazide diuretics are associated with glucose intolerance and new-onset diabetes mellitus. Previous studies demonstrated that thiazides attenuate insulin secretion, but the molecular mechanisms remain elusive. We hypothesized that thiazides attenuate insulin secretion via one of the known molecular thiazide targets in β cells. METHODS We performed static insulin secretion experiments with islets of wild-type, Sodium/chloride co-transporter (NCC) (SLC12A3), and sodium-driven chloride/bicarbonate exchanger (NDCBE) (SLC4A8) knock-out (KO) mice and with murine Min6 cells with individual knockdown of carbonic anhydrase (CA) isoforms to identify the molecular target of thiazides in β cells. CA isoform 5b (CA5b) KO mice were then used to assess the role of the putative thiazide target CA5b in β -cell function and in mediating thiazide sensitivity in vitro and in vivo . RESULTS Thiazides inhibited glucose- and sulfonylurea-stimulated insulin secretion in islets and Min6 cells at pharmacologically relevant concentrations. Inhibition of insulin secretion by thiazides was CO 2 /HCO 3- -dependent, not additive to unselective CA inhibition with acetazolamide, and independent of extracellular potassium. By contrast, insulin secretion was unaltered in islets of mice lacking the known molecular thiazide targets NCC or NDCBE. CA expression profiling with subsequent knockdown of individual CA isoforms suggested mitochondrial CA5b as a molecular target. In support of these findings, thiazides significantly attenuated Krebs cycle anaplerosis through reduction of mitochondrial oxaloacetate synthesis. CA5b KO mice were resistant to thiazide-induced glucose intolerance, and thiazides did not alter insulin secretion in CA5b KO islets. CONCLUSIONS Thiazides attenuate insulin secretion via inhibition of the mitochondrial CA5b isoform in β cells of mice.
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Affiliation(s)
- Patrycja Kucharczyk
- Department of Nephrology and Hypertension, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
- National Centre of Competence in Research (NCCR) TransCure, University of Bern, Bern, Switzerland
- Department for BioMedical Research (DBMR), University of Bern, Bern, Switzerland
| | - Giuseppe Albano
- Department of Nephrology and Hypertension, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
- National Centre of Competence in Research (NCCR) TransCure, University of Bern, Bern, Switzerland
- Department for BioMedical Research (DBMR), University of Bern, Bern, Switzerland
| | - Christine Deisl
- Department of Nephrology and Hypertension, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
- National Centre of Competence in Research (NCCR) TransCure, University of Bern, Bern, Switzerland
- Department for BioMedical Research (DBMR), University of Bern, Bern, Switzerland
| | - Tin Manh Ho
- Department of Nephrology and Hypertension, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
- National Centre of Competence in Research (NCCR) TransCure, University of Bern, Bern, Switzerland
- Department for BioMedical Research (DBMR), University of Bern, Bern, Switzerland
| | - Matteo Bargagli
- Department of Nephrology and Hypertension, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
- National Centre of Competence in Research (NCCR) TransCure, University of Bern, Bern, Switzerland
- Department for BioMedical Research (DBMR), University of Bern, Bern, Switzerland
| | - Manuel Anderegg
- Department of Nephrology and Hypertension, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
- National Centre of Competence in Research (NCCR) TransCure, University of Bern, Bern, Switzerland
- Department for BioMedical Research (DBMR), University of Bern, Bern, Switzerland
| | - Stephan Wueest
- Division of Pediatric Endocrinology and Diabetology, University Children's Hospital, University of Zürich, Zürich, Switzerland
- Children's Research Center, University Children's Hospital, University of Zürich, Zürich, Switzerland
| | - Daniel Konrad
- Division of Pediatric Endocrinology and Diabetology, University Children's Hospital, University of Zürich, Zürich, Switzerland
- Children's Research Center, University Children's Hospital, University of Zürich, Zürich, Switzerland
| | - Daniel G. Fuster
- Department of Nephrology and Hypertension, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
- National Centre of Competence in Research (NCCR) TransCure, University of Bern, Bern, Switzerland
- Department for BioMedical Research (DBMR), University of Bern, Bern, Switzerland
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Schietzel S, Anderegg M, Limacher A, Born A, Horn MP, Maurer B, Hirzel C, Sidler D, Moor MB. Humoral and cellular immune responses on SARS-CoV-2 vaccines in patients with anti-CD20 therapies: a systematic review and meta-analysis of 1342 patients. RMD Open 2022; 8:rmdopen-2021-002036. [PMID: 35115385 PMCID: PMC8814433 DOI: 10.1136/rmdopen-2021-002036] [Citation(s) in RCA: 41] [Impact Index Per Article: 20.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2021] [Accepted: 01/03/2022] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND Immune responses on SARS-CoV-2 vaccination in patients receiving anti-CD20 therapies are impaired but vary considerably. We conducted a systematic review and meta-analysis of the literature on SARS-CoV-2 vaccine induced humoral and cell-mediated immune response in patients previously treated with anti-CD20 antibodies. METHODS We searched PubMed, Embase, Medrxiv and SSRN using variations of search terms 'anti-CD20', 'vaccine' and 'COVID' and included original studies up to 21 August 2021. We excluded studies with missing data on humoral or cell-mediated immune response, unspecified methodology of response testing, unspecified timeframes between vaccination and blood sampling or low number of participants (≤3). We excluded individual patients with prior COVID-19 or incomplete vaccine courses. Primary endpoints were humoral and cell-mediated immune response rates. Subgroup analyses included time since anti-CD20 therapy, B cell depletion and indication for anti-CD20 therapy. We used random-effects models of proportions. FINDINGS Ninety studies were assessed. Inclusion criteria were met by 23 studies comprising 1342 patients. Overall rate of humoral response was 0.40 (95% CI 0.35 to 0.47). Overall rate of cell-mediated immune responses was 0.71 (95% CI 0.57 to 0.87). A time interval >6 months since last anti-CD20 therapy was associated with higher humoral response rates with 0.63 (95% CI 0.53 to 0.72) versus <6 months 0.2 (95% CI 0.03 to 0.43); p=0<01. Similarly, patients with circulating B cells more frequently showed humoral responses. Anti-CD20-treated kidney transplant recipients showed lower humoral response rates than patients with haematological malignancies or autoimmune disease. INTERPRETATION Patients on anti-CD20 therapies can develop humoral and cell-mediated immune responses after SARS-CoV-2 vaccination, but subgroups such as kidney transplant recipients or those with very recent therapy and depleted B cell are at high risk for non-seroconversion and should be individually assessed for personalised SARS-CoV-2 vaccination strategies. Potential limitations are small patient numbers and heterogeneity of studies included. FUNDING This study was funded by Bern University Hospital.
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Affiliation(s)
- Simeon Schietzel
- Department of Nephrology and Hypertension, Inselspital University Hospital Bern, Bern, Switzerland
| | - Manuel Anderegg
- Department of Nephrology and Hypertension, Inselspital University Hospital Bern, Bern, Switzerland
- Division of Nephrology, Department of Internal Medicine, Neuchâtel Hospital Network, Neuchâtel, Switzerland
| | | | - Alexander Born
- Department of Nephrology and Hypertension, Inselspital University Hospital Bern, Bern, Switzerland
| | - Michael P Horn
- Department of Clinical Chemistry, Inselspital, Bern University Hospital, Bern, Switzerland
| | - Britta Maurer
- Department of Rheumatology and Immunology, Inselspital, Bern University Hospital, Bern, Switzerland
| | - Cedric Hirzel
- Department of Infectious Diseases, Inselspital, Bern University Hospital, Bern, Switzerland
| | - Daniel Sidler
- Department of Nephrology and Hypertension, Inselspital University Hospital Bern, Bern, Switzerland
| | - Matthias B Moor
- Department of Nephrology and Hypertension, Inselspital University Hospital Bern, Bern, Switzerland
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Schnyder D, Albano G, Kucharczyk P, Dolder S, Siegrist M, Anderegg M, Pathare G, Hofstetter W, Baron R, Fuster DG. Deletion of the sodium/hydrogen exchanger 6 causes low bone volume in adult mice. Bone 2021; 153:116178. [PMID: 34508879 DOI: 10.1016/j.bone.2021.116178] [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] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Revised: 09/04/2021] [Accepted: 09/05/2021] [Indexed: 11/18/2022]
Abstract
The sodium/hydrogen exchanger 6 (NHE6) localizes to recycling endosomes, where it mediates endosomal alkalinization through K+/H+ exchange. Mutations in the SLC9A6 gene encoding NHE6 cause severe X-linked mental retardation, epilepsy, autism and corticobasal degeneration in humans. Patients with SLC9A6 mutations exhibit skeletal malformations, and a previous study suggested a key role of NHE6 in osteoblast-mediated mineralization. The goal of this study was to explore the role of NHE6 in bone homeostasis. To this end, we studied the bone phenotype of NHE6 knock-out mice by microcomputed tomography, quantitative histomorphometry and complementary ex vivo and in vitro studies. We detected NHE6 transcript and protein in both differentiated osteoclasts and mineralizing osteoblasts. In vitro studies with osteoclasts and osteoblasts derived from NHE6 knock-out mice demonstrated normal osteoclast differentiation and osteoblast proliferation without an impairment in mineralization capacity. Microcomputed tomography and bone histomorphometry studies showed a significantly reduced bone volume and trabecular number as well as an increased trabecular space at lumbar vertebrae of 6 months old NHE6 knock-out mice. The bone degradation marker c-terminal telopeptides of type I collagen was unaltered in NHE6 knock-out mice. However, we observed a reduction of the bone formation marker procollagen type 1 N-terminal propeptide, and increased circulating sclerostin levels in NHE6 knock-out mice. Subsequent studies revealed a significant upregulation of sclerostin transcript expression in both primary calvarial cultures and femora derived from NHE6 knock-out mice. Thus, loss of NHE6 in mice causes an increase of sclerostin expression associated with reduced bone formation and low bone volume.
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Affiliation(s)
- Daniela Schnyder
- Department of Nephrology and Hypertension, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland; National Centre of Competence in Research (NCCR) TransCure, University of Bern, Bern, Switzerland; Department for BioMedical Research (DBMR), University of Bern, Bern, Switzerland
| | - Giuseppe Albano
- Department of Nephrology and Hypertension, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland; National Centre of Competence in Research (NCCR) TransCure, University of Bern, Bern, Switzerland; Department for BioMedical Research (DBMR), University of Bern, Bern, Switzerland
| | - Patrycja Kucharczyk
- Department of Nephrology and Hypertension, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland; National Centre of Competence in Research (NCCR) TransCure, University of Bern, Bern, Switzerland; Department for BioMedical Research (DBMR), University of Bern, Bern, Switzerland
| | - Silvia Dolder
- National Centre of Competence in Research (NCCR) TransCure, University of Bern, Bern, Switzerland; Department for BioMedical Research (DBMR), University of Bern, Bern, Switzerland
| | - Mark Siegrist
- National Centre of Competence in Research (NCCR) TransCure, University of Bern, Bern, Switzerland; Department for BioMedical Research (DBMR), University of Bern, Bern, Switzerland
| | - Manuel Anderegg
- Department of Nephrology and Hypertension, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland; National Centre of Competence in Research (NCCR) TransCure, University of Bern, Bern, Switzerland; Department for BioMedical Research (DBMR), University of Bern, Bern, Switzerland
| | - Ganesh Pathare
- Department of Nephrology and Hypertension, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland; National Centre of Competence in Research (NCCR) TransCure, University of Bern, Bern, Switzerland; Department for BioMedical Research (DBMR), University of Bern, Bern, Switzerland
| | - Willy Hofstetter
- National Centre of Competence in Research (NCCR) TransCure, University of Bern, Bern, Switzerland; Department for BioMedical Research (DBMR), University of Bern, Bern, Switzerland
| | - Roland Baron
- Division of Bone and Mineral Research, Harvard Medical School and Harvard School of Dental Medicine, Boston, MA, USA; Department of Oral Medicine, Infection and Immunity, Harvard Medical School and Harvard School of Dental Medicine, Boston, MA, USA
| | - Daniel G Fuster
- Department of Nephrology and Hypertension, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland; National Centre of Competence in Research (NCCR) TransCure, University of Bern, Bern, Switzerland; Department for BioMedical Research (DBMR), University of Bern, Bern, Switzerland.
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Bargagli M, Dhayat NA, Anderegg M, Semmo M, Huynh-Do U, Vogt B, Ferraro PM, Fuster DG. Urinary Lithogenic Risk Profile in ADPKD Patients Treated with Tolvaptan. Clin J Am Soc Nephrol 2020; 15:1007-1014. [PMID: 32527945 PMCID: PMC7341771 DOI: 10.2215/cjn.13861119] [Citation(s) in RCA: 12] [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: 11/14/2019] [Accepted: 04/24/2020] [Indexed: 12/13/2022]
Abstract
BACKGROUND AND OBJECTIVES Nephrolithiasis is a common health problem in autosomal dominant polycystic kidney disease (ADPKD) and significantly contributes to patient morbidity. Recently, Tolvaptan has been introduced for the treatment of ADPKD, but whether it is associated with alterations of the urinary lithogenic risk profile remains unknown. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS We conducted an analysis of participants enrolled in the Bern ADPKD registry, a prospective observational cohort study. Twenty-four-hour urine analyses were performed at baseline and then at yearly follow-ups. Relative supersaturation ratios for calcium oxalate, brushite, and uric acid were calculated with the program EQUIL2. Unadjusted and multivariable mixed-effects linear regression models, adjusted for age, sex, body mass index, eGFR, net acid excretion, and height-adjusted total kidney volume, were used to assess the association of Tolvaptan with urinary parameters relevant for kidney stone formation. The maximum individual follow-up time was 3 years, median follow-up time 1.9 years, and cumulative follow-up time 169 years. RESULTS In total, 125 participants (38 with and 87 without Tolvaptan treatment) were included in the analysis. In multivariable analysis, Tolvaptan treatment was associated [adjusted estimate of the difference between Tolvaptan and no Tolvaptan; 95% confidence interval (CI)] with lower urine relative supersaturation ratios for calcium oxalate (-0.56; 95% CI, -0.82 to -0.3; P<0.001), brushite (-0.33; 95% CI, -0.54 to -0.11; P=0.004), and uric acid (-0.62; 95% CI, -0.88 to -0.37; P<0.001), and with higher urine citrate in mmol/mmol creatinine per day (0.25; 95% CI, 0.05 to 0.46; P=0.02) and calcium in mmol/mmol creatinine per day (0.31; 95% CI, 0.09 to 0.53; P=0.006) excretion. In addition, Tolvaptan treatment was associated with lower net acid excretion in mEq/mmol creatinine per day (-0.54; 95% CI, -0.90 to -0.17; P=0.004) and higher net gastrointestinal alkali absorption in mEq/mmol creatinine per day (0.57; 95% CI, 0.26 to 0.88; P<0.001). CONCLUSIONS Tolvaptan treatment is associated with a significantly improved urinary lithogenic risk profile in patients with ADPKD.
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Affiliation(s)
- Matteo Bargagli
- U.O.C. Nefrologia, Fondazione Policlinico Universitario A. Gemelli IRCCS, Rome, Italy.,Università Cattolica del Sacro Cuore, Rome, Italy
| | - Nasser A Dhayat
- Department of Nephrology and Hypertension, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
| | - Manuel Anderegg
- Department of Nephrology and Hypertension, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
| | - Mariam Semmo
- Department of Nephrology and Hypertension, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
| | - Uyen Huynh-Do
- Department of Nephrology and Hypertension, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
| | - Bruno Vogt
- Department of Nephrology and Hypertension, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
| | - Pietro Manuel Ferraro
- U.O.C. Nefrologia, Fondazione Policlinico Universitario A. Gemelli IRCCS, Rome, Italy.,Università Cattolica del Sacro Cuore, Rome, Italy
| | - Daniel G Fuster
- Department of Nephrology and Hypertension, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
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Bargagli M, Dhayat NA, Anderegg M, Semmo M, Huynh-Do U, Vogt B, Ferraro PM, Fuster DG. SO010URINARY LITHOGENIC RISK PROFILE IN ADPKD PATIENTS TREATED WITH TOLVAPTAN. Nephrol Dial Transplant 2020. [DOI: 10.1093/ndt/gfaa139.so010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Abstract
Background and Aims
Nephrolithiasis is a common health problem in autosomal dominant polycystic kidney disease (ADPKD) and significantly contributes to patient morbidity. In observational studies, prevalence rates of up to 36% have been reported. Kidney stones of ADPKD patients are typically composed of uric acid (UA) or calcium oxalate (CaOx), and hypocitraturia and low urinary pH have been reported as the main prolithogenic abnormalities. Recently, Tolvaptan has been introduced for the treatment of ADPKD, but its impact on the lithogenic risk profile in ADPKD patients remains unknown.
Method
We conducted a retrospective analysis of patients enrolled in the Bern ADPKD registry, an observational cohort study. Inclusion criteria were age ≥ 18 years, clinical diagnosis of ADPKD, and informed consent. The main exclusion criterion was need for renal replacement therapy. 24-h urine analyses were performed at baseline and then at yearly follow-ups. Relative supersaturation ratios (RSS) for CaOx, calcium phoshate (CaP) and UA were calculated with EQUIL2. Univariate and multivariate mixed-effects linear regression models, adjusted for age, sex, BMI, eGFR and endogenous acid production, estimated by net acid excretion, were used to assess the impact of Tolvaptan treatment on urinary composition.
Results
38 patients received Tolvaptan treatment (39.5% females) and were included in the analysis. Six patients (15.8%) had a history of symptomatic stone events. In multivariate analysis, Tolvaptan treatment was significantly associated with reductions of CaOx, CaP and UA RSS (p < 0.01) and increased urinary citrate (p = 0.015) and calcium (p < 0.01) excretion. In contrast, Tolvaptan treatment was not associated with alterations in urinary oxalate excretion or urinary pH.
Conclusion
Tolvaptan significantly reduces RSS for CaOx, CaP and UA. Future studies are needed to assess the impact of Tolvaptan treatment on stone recurrence in ADPKD patients.
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Affiliation(s)
| | - Nasser A Dhayat
- Inselspital, Bern University Hospital, University of Bern, Department of Nephrology and Hypertension, Bern, Switzerland
| | - Manuel Anderegg
- Inselspital, Bern University Hospital, University of Bern, Department of Nephrology and Hypertension, Bern, Switzerland
| | - Mariam Semmo
- Inselspital, Bern University Hospital, University of Bern, Department of Nephrology and Hypertension, Bern, Switzerland
| | - Uyen Huynh-Do
- Inselspital, Bern University Hospital, University of Bern, Department of Nephrology and Hypertension, Bern, Switzerland
| | - Bruno Vogt
- Inselspital, Bern University Hospital, University of Bern, Department of Nephrology and Hypertension, Bern, Switzerland
| | - Pietro Manuel Ferraro
- Università Cattolica del Sacro Cuore, Roma, Italy
- Fondazione Policlinico Universitario A. Gemelli IRCCS, U.O.C. Nefrologia, Roma, Italy
| | - Daniel Guido Fuster
- Inselspital, Bern University Hospital, University of Bern, Department of Nephrology and Hypertension, Bern, Switzerland
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Beljaars PR, Dijk RV, Brands A, Anderegg M, Arnold M, Bodegraven PJ, Bosman I, Burgers L, Gend HW, van der Horst GM, Hoven K, Kaman R, Leeuwen WV, Lukkenaer J, Nijboer L, Roukema J, Scholten J, Sens J, van Veldhuizen CJ, Visschedijk MBC, Wijma E. Continuous Flow and Liquid Chromatographic Determination of p-Toluenesulfonamide in Ice Cream: Interlaboratory Study. J AOAC Int 2020. [DOI: 10.1093/jaoac/76.3.570] [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: 11/15/2022]
Abstract
Abstract
A collaborative study of the continuous flow (CF) and liquid chromatographic determination of p-toluenesulfonamide (p-TSA) in ice cream was conducted by the Project Group on Collaborative Studies (PCS) of the Inspectorate for Health Protection, Food Inspection Service, The Netherlands. The procedure involves extraction of samples with water followed by cleanup of the extracts by dialysis in the CF system. Dialysates are injected by using a loop injector (500 μL) on a reversed-phase octadecylsilane bonded-phase (C18) column, chromatographed with methanol-water (25 + 75, v/v) as mobile phase, and quantitated by fluorescence detection at 230 nm (excitation) and 295 nm (emission). Seven ice-cream samples containing 0-6.35 mg/kg p-TSA at 4 different levels (1 blank and 3 pairs of split-level samples) were singularly analyzed according to the proposed procedure by 11 laboratories. The data were analyzed by the International Union of Pure and Applied Chemistry/ International Organization for Standardization/ AOAC protocol for statistics. No Cochran and Grubbs outliers were found among the participants. For all samples analyzed, repeatability relative standard deviations (RSDr) varied from 2.08 to 3.67%, whereas the reproducibility relative standard deviations (RSDR) ranged from 7.79 to 11.68%. The average p-TSA values for the split levels 1,2, and 3 were 0.55, 1.02, and 4.44 mg p-TSA/kg, respectively, with mean recoveries ranging from 76 to 79% (overall recovery range for all levels, 63-101%). No false-positive results were reported for the blank sample, and no interference was encountered by the presence of vanilla in samples.
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Affiliation(s)
- Paul R Beljaars
- Inspectorate for Health Protection, Food Inspection Service, PO Box 2516, 6201 CA Maastricht, The Netherlands
| | - Remmelt Van Dijk
- Inspectorate for Health Protection, Food Inspection Service, PO Box 465, 9700 AL Groningen, The Netherlands
| | - Arie Brands
- Inspectorate for Health Protection, Food Inspection Service, Hoogte Kadijk 401, 1018 BK Amsterdam, The Netherlands
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Dhayat NA, Gradwell MW, Pathare G, Anderegg M, Schneider L, Luethi D, Mattmann C, Moe OW, Vogt B, Fuster DG. Furosemide/Fludrocortisone Test and Clinical Parameters to Diagnose Incomplete Distal Renal Tubular Acidosis in Kidney Stone Formers. Clin J Am Soc Nephrol 2017; 12:1507-1517. [PMID: 28775126 PMCID: PMC5586565 DOI: 10.2215/cjn.01320217] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [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: 02/04/2017] [Accepted: 05/12/2017] [Indexed: 11/23/2022]
Abstract
BACKGROUND AND OBJECTIVES Incomplete distal renal tubular acidosis is a well known cause of calcareous nephrolithiasis but the prevalence is unknown, mostly due to lack of accepted diagnostic tests and criteria. The ammonium chloride test is considered as gold standard for the diagnosis of incomplete distal renal tubular acidosis, but the furosemide/fludrocortisone test was recently proposed as an alternative. Because of the lack of rigorous comparative studies, the validity of the furosemide/fludrocortisone test in stone formers remains unknown. In addition, the performance of conventional, nonprovocative parameters in predicting incomplete distal renal tubular acidosis has not been studied. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS We conducted a prospective study in an unselected cohort of 170 stone formers that underwent sequential ammonium chloride and furosemide/fludrocortisone testing. RESULTS Using the ammonium chloride test as gold standard, the prevalence of incomplete distal renal tubular acidosis was 8%. Sensitivity and specificity of the furosemide/fludrocortisone test were 77% and 85%, respectively, yielding a positive predictive value of 30% and a negative predictive value of 98%. Testing of several nonprovocative clinical parameters in the prediction of incomplete distal renal tubular acidosis revealed fasting morning urinary pH and plasma potassium as the most discriminative parameters. The combination of a fasting morning urinary threshold pH <5.3 with a plasma potassium threshold >3.8 mEq/L yielded a negative predictive value of 98% with a sensitivity of 85% and a specificity of 77% for the diagnosis of incomplete distal renal tubular acidosis. CONCLUSIONS The furosemide/fludrocortisone test can be used for incomplete distal renal tubular acidosis screening in stone formers, but an abnormal furosemide/fludrocortisone test result needs confirmation by ammonium chloride testing. Our data furthermore indicate that incomplete distal renal tubular acidosis can reliably be excluded in stone formers by use of nonprovocative clinical parameters.
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Affiliation(s)
- Nasser A. Dhayat
- Division of Nephrology and Hypertension, Bern University Hospital, Bern, Switzerland
| | - Michael W. Gradwell
- Division of Nephrology and Hypertension, Bern University Hospital, Bern, Switzerland
| | - Ganesh Pathare
- Division of Nephrology and Hypertension, Bern University Hospital, Bern, Switzerland
- Swiss National Centre of Competence in Research TransCure, University of Bern, Bern, Switzerland
| | - Manuel Anderegg
- Division of Nephrology and Hypertension, Bern University Hospital, Bern, Switzerland
- Swiss National Centre of Competence in Research TransCure, University of Bern, Bern, Switzerland
| | - Lisa Schneider
- Division of Nephrology and Hypertension, Bern University Hospital, Bern, Switzerland
| | - David Luethi
- Division of Nephrology and Hypertension, Bern University Hospital, Bern, Switzerland
| | - Cedric Mattmann
- Division of Nephrology and Hypertension, Bern University Hospital, Bern, Switzerland
| | - Orson W. Moe
- Departments of Internal Medicine and Physiology, and the Charles and Jane Pak Center of Mineral Metabolism and Clinical Research, University of Texas Southwestern Medical Center, Dallas, Texas; and
| | - Bruno Vogt
- Division of Nephrology and Hypertension, Bern University Hospital, Bern, Switzerland
| | - Daniel G. Fuster
- Division of Nephrology and Hypertension, Bern University Hospital, Bern, Switzerland
- Swiss National Centre of Competence in Research TransCure, University of Bern, Bern, Switzerland
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Deisl C, Anderegg M, Albano G, Lüscher BP, Cerny D, Soria R, Bouillet E, Rimoldi S, Scherrer U, Fuster DG. Loss of Sodium/Hydrogen Exchanger NHA2 Exacerbates Obesity- and Aging-Induced Glucose Intolerance in Mice. PLoS One 2016; 11:e0163568. [PMID: 27685945 PMCID: PMC5042380 DOI: 10.1371/journal.pone.0163568] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2016] [Accepted: 09/11/2016] [Indexed: 11/21/2022] Open
Abstract
We previously demonstrated that the sodium/hydrogen exchanger NHA2, also known as NHEDC2 or SLC9B2, is critical for insulin secretion by β–cells. To gain more insights into the role of NHA2 on systemic glucose homeostasis, we studied the impact of loss of NHA2 during the physiological aging process and in the setting of diet-induced obesity. While glucose tolerance was normal at 2 months of age, NHA2 KO mice displayed a significant glucose intolerance at 5 and 12 months of age, respectively. An obesogenic high fat diet further exacerbated the glucose intolerance of NHA2 KO mice. Insulin levels remained similar in NHA2 KO and WT mice during aging and high fat diet, but fasting insulin/glucose ratios were significantly lower in NHA2 KO mice. Peripheral insulin sensitivity, measured by insulin tolerance tests and hyperinsulinemic euglycemic clamps, was unaffected by loss of NHA2 during aging and high fat diet. High fat diet diminished insulin secretion capacity in both WT and NHA2 KO islets and reduced expression of NHA2 in WT islets. In contrast, aging was characterized by a gradual increase of NHA2 expression in islets, paralleled by an increasing difference in insulin secretion between WT and NHA2 KO islets. In summary, our results demonstrate that loss of the sodium/hydrogen exchanger NHA2 exacerbates obesity- and aging-induced glucose intolerance in mice. Furthermore, our data reveal a close link between NHA2 expression and insulin secretion capacity in islets.
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Affiliation(s)
- Christine Deisl
- Division of Nephrology, Hypertension and Clinical Pharmacology, Bern University Hospital, University of Bern, Bern, Switzerland
- Institute of Biochemistry and Molecular Medicine and Swiss National Centre of Competence in Research (NCCR) TransCure, University of Bern, Bern, Switzerland
- Department of Clinical Research, Bern University Hospital, University of Bern, Bern Switzerland
| | - Manuel Anderegg
- Division of Nephrology, Hypertension and Clinical Pharmacology, Bern University Hospital, University of Bern, Bern, Switzerland
- Institute of Biochemistry and Molecular Medicine and Swiss National Centre of Competence in Research (NCCR) TransCure, University of Bern, Bern, Switzerland
- Department of Clinical Research, Bern University Hospital, University of Bern, Bern Switzerland
| | - Giuseppe Albano
- Division of Nephrology, Hypertension and Clinical Pharmacology, Bern University Hospital, University of Bern, Bern, Switzerland
- Institute of Biochemistry and Molecular Medicine and Swiss National Centre of Competence in Research (NCCR) TransCure, University of Bern, Bern, Switzerland
- Department of Clinical Research, Bern University Hospital, University of Bern, Bern Switzerland
| | - Benjamin P. Lüscher
- Institute of Biochemistry and Molecular Medicine and Swiss National Centre of Competence in Research (NCCR) TransCure, University of Bern, Bern, Switzerland
- Department of Clinical Research, Bern University Hospital, University of Bern, Bern Switzerland
| | - David Cerny
- Department of Clinical Research, Bern University Hospital, University of Bern, Bern Switzerland
- Division of Cardiology, Bern University Hospital, University of Bern, Bern, Switzerland
| | - Rodrigo Soria
- Department of Clinical Research, Bern University Hospital, University of Bern, Bern Switzerland
- Division of Cardiology, Bern University Hospital, University of Bern, Bern, Switzerland
| | - Elisa Bouillet
- Department of Clinical Research, Bern University Hospital, University of Bern, Bern Switzerland
- Division of Cardiology, Bern University Hospital, University of Bern, Bern, Switzerland
| | - Stefano Rimoldi
- Department of Clinical Research, Bern University Hospital, University of Bern, Bern Switzerland
- Division of Cardiology, Bern University Hospital, University of Bern, Bern, Switzerland
| | - Urs Scherrer
- Department of Clinical Research, Bern University Hospital, University of Bern, Bern Switzerland
- Division of Cardiology, Bern University Hospital, University of Bern, Bern, Switzerland
- Facultad de Ciencias, Departamento de Biologia, Universidad de Tarapaca, Arica, Chile
| | - Daniel G. Fuster
- Division of Nephrology, Hypertension and Clinical Pharmacology, Bern University Hospital, University of Bern, Bern, Switzerland
- Institute of Biochemistry and Molecular Medicine and Swiss National Centre of Competence in Research (NCCR) TransCure, University of Bern, Bern, Switzerland
- Department of Clinical Research, Bern University Hospital, University of Bern, Bern Switzerland
- * E-mail:
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9
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Dhayat N, Simonin A, Anderegg M, Pathare G, Lüscher BP, Deisl C, Albano G, Mordasini D, Hediger MA, Surbek DV, Vogt B, Sass JO, Kloeckener-Gruissem B, Fuster DG. Mutation in the Monocarboxylate Transporter 12 Gene Affects Guanidinoacetate Excretion but Does Not Cause Glucosuria. J Am Soc Nephrol 2015; 27:1426-36. [PMID: 26376857 DOI: 10.1681/asn.2015040411] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [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: 04/16/2015] [Accepted: 08/05/2015] [Indexed: 01/08/2023] Open
Abstract
A heterozygous mutation (c.643C>A; p.Q215X) in the monocarboxylate transporter 12-encoding gene MCT12 (also known as SLC16A12) that mediates creatine transport was recently identified as the cause of a syndrome with juvenile cataracts, microcornea, and glucosuria in a single family. Whereas the MCT12 mutation cosegregated with the eye phenotype, poor correlation with the glucosuria phenotype did not support a pathogenic role of the mutation in the kidney. Here, we examined MCT12 in the kidney and found that it resides on basolateral membranes of proximal tubules. Patients with MCT12 mutation exhibited reduced plasma levels and increased fractional excretion of guanidinoacetate, but normal creatine levels, suggesting that MCT12 may function as a guanidinoacetate transporter in vivo However, functional studies in Xenopus oocytes revealed that MCT12 transports creatine but not its precursor, guanidinoacetate. Genetic analysis revealed a separate, undescribed heterozygous mutation (c.265G>A; p.A89T) in the sodium/glucose cotransporter 2-encoding gene SGLT2 (also known as SLC5A2) in the family that segregated with the renal glucosuria phenotype. When overexpressed in HEK293 cells, the mutant SGLT2 transporter did not efficiently translocate to the plasma membrane, and displayed greatly reduced transport activity. In summary, our data indicate that MCT12 functions as a basolateral exit pathway for creatine in the proximal tubule. Heterozygous mutation of MCT12 affects systemic levels and renal handling of guanidinoacetate, possibly through an indirect mechanism. Furthermore, our data reveal a digenic syndrome in the index family, with simultaneous MCT12 and SGLT2 mutation. Thus, glucosuria is not part of the MCT12 mutation syndrome.
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Affiliation(s)
- Nasser Dhayat
- Division of Nephrology, Hypertension and Clinical Pharmacology, and Department of Clinical Research, University of Bern, Switzerland
| | - Alexandre Simonin
- Institute of Biochemistry and Molecular Medicine, Swiss National Centre of Competence in Research Transcure, and
| | - Manuel Anderegg
- Division of Nephrology, Hypertension and Clinical Pharmacology, and Department of Clinical Research, University of Bern, Switzerland; Institute of Biochemistry and Molecular Medicine, Swiss National Centre of Competence in Research Transcure, and
| | - Ganesh Pathare
- Division of Nephrology, Hypertension and Clinical Pharmacology, and Department of Clinical Research, University of Bern, Switzerland; Institute of Biochemistry and Molecular Medicine, Swiss National Centre of Competence in Research Transcure, and
| | - Benjamin P Lüscher
- Department of Clinical Research, University of Bern, Switzerland; Swiss National Centre of Competence in Research Transcure, and Department of Obstetrics and Gynecology, University Hospital of Bern, Switzerland
| | - Christine Deisl
- Division of Nephrology, Hypertension and Clinical Pharmacology, and Department of Clinical Research, University of Bern, Switzerland; Institute of Biochemistry and Molecular Medicine, Swiss National Centre of Competence in Research Transcure, and
| | - Giuseppe Albano
- Division of Nephrology, Hypertension and Clinical Pharmacology, and Department of Clinical Research, University of Bern, Switzerland; Institute of Biochemistry and Molecular Medicine, Swiss National Centre of Competence in Research Transcure, and
| | - David Mordasini
- Division of Nephrology, Hypertension and Clinical Pharmacology, and Department of Clinical Research, University of Bern, Switzerland
| | - Matthias A Hediger
- Institute of Biochemistry and Molecular Medicine, Swiss National Centre of Competence in Research Transcure, and Department of Obstetrics and Gynecology, University Hospital of Bern, Switzerland
| | - Daniel V Surbek
- Department of Clinical Research, University of Bern, Switzerland; Swiss National Centre of Competence in Research Transcure, and Department of Obstetrics and Gynecology, University Hospital of Bern, Switzerland
| | - Bruno Vogt
- Division of Nephrology, Hypertension and Clinical Pharmacology, and Department of Clinical Research, University of Bern, Switzerland
| | - Jörn Oliver Sass
- Division of Clinical Chemistry and Biochemistry, Children's Research Center, University Children's Hospital, Zürich, Switzerland; Department of Natural Sciences, Bonn-Rhein-Sieg University of Applied Sciences, Rheinbach, Germany
| | - Barbara Kloeckener-Gruissem
- Institute of Medical Molecular Genetics, University of Zürich, Zürich, Switzerland; and Department of Biology, Swiss Federal Institute of Technology in Zürich, Zürich, Switzerland
| | - Daniel G Fuster
- Division of Nephrology, Hypertension and Clinical Pharmacology, and Department of Clinical Research, University of Bern, Switzerland; Institute of Biochemistry and Molecular Medicine, Swiss National Centre of Competence in Research Transcure, and
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10
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Rexhaj E, Paoloni-Giacobino A, Rimoldi SF, Fuster DG, Anderegg M, Somm E, Bouillet E, Allemann Y, Sartori C, Scherrer U. Mice generated by in vitro fertilization exhibit vascular dysfunction and shortened life span. J Clin Invest 2013; 123:5052-60. [PMID: 24270419 PMCID: PMC3859389 DOI: 10.1172/jci68943] [Citation(s) in RCA: 134] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2013] [Accepted: 09/04/2013] [Indexed: 12/11/2022] Open
Abstract
Children conceived by assisted reproductive technologies (ART) display a level of vascular dysfunction similar to that seen in children of mothers with preeclamspia. The long-term consequences of ART-associated vascular disorders are unknown and difficult to investigate in healthy children. Here, we found that vasculature from mice generated by ART display endothelial dysfunction and increased stiffness, which translated into arterial hypertension in vivo. Progeny of male ART mice also exhibited vascular dysfunction, suggesting underlying epigenetic modifications. ART mice had altered methylation at the promoter of the gene encoding eNOS in the aorta, which correlated with decreased vascular eNOS expression and NO synthesis. Administration of a deacetylase inhibitor to ART mice normalized vascular gene methylation and function and resulted in progeny without vascular dysfunction. The induction of ART-associated vascular and epigenetic alterations appeared to be related to the embryo environment; these alterations were possibly facilitated by the hormonally stimulated ovulation accompanying ART. Finally, ART mice challenged with a high-fat diet had roughly a 25% shorter life span compared with control animals. This study highlights the potential of ART to induce vascular dysfunction and shorten life span and suggests that epigenetic alterations contribute to these problems.
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Affiliation(s)
- Emrush Rexhaj
- Swiss Cardiovascular Center Bern and Department of Clinical Research, University Hospital, Bern, Switzerland.
Department of Genetic and Laboratory Medicine and Swiss Center for Applied Human Toxicology, Geneva University Hospital, Geneva, Switzerland.
Division of Nephrology, Hypertension and Clinical Pharmacology, University Hospital, Bern, Switzerland.
Division of Development and Growth, Department of Paediatrics, University of Geneva Medical School, Geneva, Switzerland.
Department of Internal Medicine, CHUV, Lausanne, Switzerland.
Facultad de Ciencias, Departamento de Biología, Universidad de Tarapacá, Arica, Chile
| | - Ariane Paoloni-Giacobino
- Swiss Cardiovascular Center Bern and Department of Clinical Research, University Hospital, Bern, Switzerland.
Department of Genetic and Laboratory Medicine and Swiss Center for Applied Human Toxicology, Geneva University Hospital, Geneva, Switzerland.
Division of Nephrology, Hypertension and Clinical Pharmacology, University Hospital, Bern, Switzerland.
Division of Development and Growth, Department of Paediatrics, University of Geneva Medical School, Geneva, Switzerland.
Department of Internal Medicine, CHUV, Lausanne, Switzerland.
Facultad de Ciencias, Departamento de Biología, Universidad de Tarapacá, Arica, Chile
| | - Stefano F. Rimoldi
- Swiss Cardiovascular Center Bern and Department of Clinical Research, University Hospital, Bern, Switzerland.
Department of Genetic and Laboratory Medicine and Swiss Center for Applied Human Toxicology, Geneva University Hospital, Geneva, Switzerland.
Division of Nephrology, Hypertension and Clinical Pharmacology, University Hospital, Bern, Switzerland.
Division of Development and Growth, Department of Paediatrics, University of Geneva Medical School, Geneva, Switzerland.
Department of Internal Medicine, CHUV, Lausanne, Switzerland.
Facultad de Ciencias, Departamento de Biología, Universidad de Tarapacá, Arica, Chile
| | - Daniel G. Fuster
- Swiss Cardiovascular Center Bern and Department of Clinical Research, University Hospital, Bern, Switzerland.
Department of Genetic and Laboratory Medicine and Swiss Center for Applied Human Toxicology, Geneva University Hospital, Geneva, Switzerland.
Division of Nephrology, Hypertension and Clinical Pharmacology, University Hospital, Bern, Switzerland.
Division of Development and Growth, Department of Paediatrics, University of Geneva Medical School, Geneva, Switzerland.
Department of Internal Medicine, CHUV, Lausanne, Switzerland.
Facultad de Ciencias, Departamento de Biología, Universidad de Tarapacá, Arica, Chile
| | - Manuel Anderegg
- Swiss Cardiovascular Center Bern and Department of Clinical Research, University Hospital, Bern, Switzerland.
Department of Genetic and Laboratory Medicine and Swiss Center for Applied Human Toxicology, Geneva University Hospital, Geneva, Switzerland.
Division of Nephrology, Hypertension and Clinical Pharmacology, University Hospital, Bern, Switzerland.
Division of Development and Growth, Department of Paediatrics, University of Geneva Medical School, Geneva, Switzerland.
Department of Internal Medicine, CHUV, Lausanne, Switzerland.
Facultad de Ciencias, Departamento de Biología, Universidad de Tarapacá, Arica, Chile
| | - Emmanuel Somm
- Swiss Cardiovascular Center Bern and Department of Clinical Research, University Hospital, Bern, Switzerland.
Department of Genetic and Laboratory Medicine and Swiss Center for Applied Human Toxicology, Geneva University Hospital, Geneva, Switzerland.
Division of Nephrology, Hypertension and Clinical Pharmacology, University Hospital, Bern, Switzerland.
Division of Development and Growth, Department of Paediatrics, University of Geneva Medical School, Geneva, Switzerland.
Department of Internal Medicine, CHUV, Lausanne, Switzerland.
Facultad de Ciencias, Departamento de Biología, Universidad de Tarapacá, Arica, Chile
| | - Elisa Bouillet
- Swiss Cardiovascular Center Bern and Department of Clinical Research, University Hospital, Bern, Switzerland.
Department of Genetic and Laboratory Medicine and Swiss Center for Applied Human Toxicology, Geneva University Hospital, Geneva, Switzerland.
Division of Nephrology, Hypertension and Clinical Pharmacology, University Hospital, Bern, Switzerland.
Division of Development and Growth, Department of Paediatrics, University of Geneva Medical School, Geneva, Switzerland.
Department of Internal Medicine, CHUV, Lausanne, Switzerland.
Facultad de Ciencias, Departamento de Biología, Universidad de Tarapacá, Arica, Chile
| | - Yves Allemann
- Swiss Cardiovascular Center Bern and Department of Clinical Research, University Hospital, Bern, Switzerland.
Department of Genetic and Laboratory Medicine and Swiss Center for Applied Human Toxicology, Geneva University Hospital, Geneva, Switzerland.
Division of Nephrology, Hypertension and Clinical Pharmacology, University Hospital, Bern, Switzerland.
Division of Development and Growth, Department of Paediatrics, University of Geneva Medical School, Geneva, Switzerland.
Department of Internal Medicine, CHUV, Lausanne, Switzerland.
Facultad de Ciencias, Departamento de Biología, Universidad de Tarapacá, Arica, Chile
| | - Claudio Sartori
- Swiss Cardiovascular Center Bern and Department of Clinical Research, University Hospital, Bern, Switzerland.
Department of Genetic and Laboratory Medicine and Swiss Center for Applied Human Toxicology, Geneva University Hospital, Geneva, Switzerland.
Division of Nephrology, Hypertension and Clinical Pharmacology, University Hospital, Bern, Switzerland.
Division of Development and Growth, Department of Paediatrics, University of Geneva Medical School, Geneva, Switzerland.
Department of Internal Medicine, CHUV, Lausanne, Switzerland.
Facultad de Ciencias, Departamento de Biología, Universidad de Tarapacá, Arica, Chile
| | - Urs Scherrer
- Swiss Cardiovascular Center Bern and Department of Clinical Research, University Hospital, Bern, Switzerland.
Department of Genetic and Laboratory Medicine and Swiss Center for Applied Human Toxicology, Geneva University Hospital, Geneva, Switzerland.
Division of Nephrology, Hypertension and Clinical Pharmacology, University Hospital, Bern, Switzerland.
Division of Development and Growth, Department of Paediatrics, University of Geneva Medical School, Geneva, Switzerland.
Department of Internal Medicine, CHUV, Lausanne, Switzerland.
Facultad de Ciencias, Departamento de Biología, Universidad de Tarapacá, Arica, Chile
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11
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Anderegg M, Schwick N, Schmid JP. [Suddenly occurring exercise intolerance]. Praxis (Bern 1994) 2007; 96:1435-1438. [PMID: 17933287 DOI: 10.1024/1661-8157.96.38.1435] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
In this case report, the differencial diagnosis of exercise intolerance associated with dyspnea and the diagnostic approach with cardio-pulmonary exercise testing with detection of an exercise induced second-degree atrio-ventricular block as a cause of chronotropic incompetence is described.
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Affiliation(s)
- M Anderegg
- Klinik und Poliklinik für Kardiologie, Schweizer Herz- und Gefässzentrum, Universitïtsklinik Inselspital Bern
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12
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Grafanaki S, Pearson D, Cini F, Godula D, Mckenzie B, Nason S, Anderegg M. Sources of renewal: A qualitative study on the experience and role of leisure in the life of counsellors and psychologists. Counselling Psychology Quarterly 2005. [DOI: 10.1080/09515070500099660] [Citation(s) in RCA: 10] [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: 10/23/2022]
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13
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Bruengger A, Heilbronner R, Anderegg M, Hubler M, Rohr HP. Human skin grafts on nude athymic mice: a light microscopic stereological study. Arch Dermatol Res 1984; 276:78-81. [PMID: 6372709 DOI: 10.1007/bf00511059] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
A morphometric procedure is presented, which allows quantitative information to be obtained from the epidermis at the light microscope level. The application of this procedure to human skin grafted to the nude mouse revealed acanthosis of the grafted epidermis compared to the original donor skin. All epidermal layers were thicker, but the increase in the granular layer was especially marked. The ratio of the basement membrane surface to the epithelial surface showed no significant change. A possible explanation for the acanthosis of the graft might be the higher mechanical stress on the nude mouse compared to the original site on the abdomen. This adaptation of the grafted epidermis does not limit the usefulness of this animal model for dermatological research, when it is assessed by objective methods, allowing statistical comparison as described here.
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14
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Baluteau JP, Anderegg M, Moorwood AF, Coron N, Beckman JE, Bussoletti E, Hippelein HH. High resolution Michelson interferometer for airborne infrared astronomical observations. 1: Concept and performance. Appl Opt 1977; 16:1834-1840. [PMID: 20168819 DOI: 10.1364/ao.16.001834] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
A Michelson interferometer has been built for use with the 91-cm telescope on NASA's Gerard P. Kuiper Airborne Observatory primarily to measure ir line emission from H 11 regions. Operation is in the rapid scan mode, and the achievable resolution is 0.02 cm(-1) in the wavelength range from 10 micro to around 300 micro. A minicomputer is used to provide on-line spectrum displays and to control and monitor the instrument performance. The design and use of the instrument is discussed, and a comparison is made between the theoretical performance and that actually achieved on the first flights when measurements of line emission from the Orion nebula and from the atmosphere were made.
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15
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Baluteau J, Marten A, Bussoletti E, Anderegg M, Beckman J, Moorwood A, Coron N. High resolution infrared spectra of the earth's atmosphere—II. Ground-based observations in the 500–570 cm−1 range. ACTA ACUST UNITED AC 1977. [DOI: 10.1016/0020-0891(77)90014-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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