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Mainali K, Evans M, Saavedra D, Mills E, Madsen B, Minnemeyer S. Convolutional neural network for high-resolution wetland mapping with open data: Variable selection and the challenges of a generalizable model. Sci Total Environ 2023; 861:160622. [PMID: 36462655 DOI: 10.1016/j.scitotenv.2022.160622] [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] [Subscribe] [Scholar Register] [Received: 06/14/2022] [Revised: 11/24/2022] [Accepted: 11/27/2022] [Indexed: 06/17/2023]
Abstract
Landscape scale wetland conservation requires accurate, up-to-date wetland maps. The most useful approaches to creating such maps are automated, spatially generalizable, temporally repeatable, and can be applied at large spatial scales. However, mapping wetlands with predictive models is challenging due to the highly variable characteristics of wetlands in both space and time. Currently, most approaches are limited by coarse resolution, commercial data, and geographic specificity. Here, we trained a deep learning model and evaluated its ability to automatically map wetlands at landscape scale in a variety of geographies. We trained a U-Net architecture to map wetlands at 1-meter spatial resolution with the following remotely sensed covariates: multispectral data from the National Agriculture Imagery Program and the Sentinel-2 satellite system, and two LiDAR-derived datasets, intensity and geomorphons. The full model mapped wetlands accurately (94 % accuracy, 96.5 % precision, 95.2 % AUC) at 1-meter resolution. Post hoc model evaluation showed that the model correctly predicted wetlands even in areas that had incorrect label/training data, which penalized the recall rate (90.2 %). Applying the model in a new geography resulted in poor performance (precision = ~80 %, recall = 48 %). However, limited retraining in this geography improved model performance substantially, demonstrating an effective means to create a spatially generalizable model. We demonstrate wetlands can be mapped at high-resolution (1 m) using free data and efficient deep-learning models that do not require manual feature engineering. Including LiDAR and geomorphons as input data improved model accuracy by 2 %, and where these data are unavailable a simpler model can efficiently map wetlands. Given the dynamic nature of wetlands and the important ecosystem services they provide, high-resolution mapping can be a game changer in terms of informing restoration and development decisions.
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Affiliation(s)
- Kumar Mainali
- Chesapeake Conservancy, Conservation Innovation Center, 716 Giddings Avenue, Suite 42, Annapolis, MD 21401, United States of America; Department of Biology, University of Maryland, College Park, MD, United States of America.
| | - Michael Evans
- Chesapeake Conservancy, Conservation Innovation Center, 716 Giddings Avenue, Suite 42, Annapolis, MD 21401, United States of America; Environmental Science and Policy Department, George Mason University, Fairfax, VA, United States of America.
| | - David Saavedra
- Chesapeake Conservancy, Conservation Innovation Center, 716 Giddings Avenue, Suite 42, Annapolis, MD 21401, United States of America
| | - Emily Mills
- Chesapeake Conservancy, Conservation Innovation Center, 716 Giddings Avenue, Suite 42, Annapolis, MD 21401, United States of America; World Wildlife Fund, 1250 24(th) Street NW, Washington, DC 20037, United States of America
| | - Becca Madsen
- Electric Power Research Institute, Palo Alto, CA 94304, United States of America
| | - Susan Minnemeyer
- Chesapeake Conservancy, Conservation Innovation Center, 716 Giddings Avenue, Suite 42, Annapolis, MD 21401, United States of America
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Surrey KC, Iacona G, Madsen B, Newman C, Gerber LR. Habitat Conservation Plans provide limited insight into the cost of complying with the Endangered Species Act. Conservat Sci and Prac 2022. [DOI: 10.1111/csp2.12673] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Affiliation(s)
- Katie C. Surrey
- Center for Biodiversity Outcomes, School of Life Sciences, Arizona State University Tempe Arizona USA
| | - Gwenllian Iacona
- Center for Biodiversity Outcomes, School of Life Sciences, Arizona State University Tempe Arizona USA
| | - Becca Madsen
- Electric Power Research Institute Palo Alto California USA
| | | | - Leah R. Gerber
- Center for Biodiversity Outcomes, School of Life Sciences, Arizona State University Tempe Arizona USA
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Järleblad H, Stagner L, Salewski M, Eriksson J, Benjamin S, Madsen B, Nocente M, Rasmussen J, Schmidt BS. Fast-ion orbit sensitivity of neutron emission spectroscopy diagnostics. Rev Sci Instrum 2021; 92:043526. [PMID: 34243421 DOI: 10.1063/5.0040696] [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] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Accepted: 03/23/2021] [Indexed: 06/13/2023]
Abstract
Fast ions in fusion plasmas often leave characteristic signatures in the plasma neutron emission. Measurements of this emission are subject to the phase-space sensitivity of the diagnostic, which can be mapped using weight functions. In this paper, we present orbit weight functions for the TOFOR and NE213 neutron diagnostics at the Joint European Torus, mapping their phase-space sensitivity in 3D orbit space. Both diagnostics are highly sensitive to fast ions that spend a relatively large fraction of their orbit transit times inside the viewing cone of the diagnostic. For most neutron energies, TOFOR is found to be relatively sensitive to potato orbits and heavily localized counter-passing orbits, as well as trapped orbits whose "banana tips" are inside the viewing cone of TOFOR. For the NE213-scintillator, the sensitivity is found to be relatively high for stagnation orbits.
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Affiliation(s)
- H Järleblad
- Department of Physics, Technical University of Denmark, DK-2800 Kgs. Lyngby, Denmark
| | - L Stagner
- General Atomics, P.O. Box 85608, San Diego, California 92186-5608, USA
| | - M Salewski
- Department of Physics, Technical University of Denmark, DK-2800 Kgs. Lyngby, Denmark
| | - J Eriksson
- Department of Physics and Astronomy, Uppsala University, 751 20 Uppsala, Sweden
| | - S Benjamin
- Mathematical Sciences Institute, Australian National University, Canberra ACT 2601, Australia
| | - B Madsen
- Department of Physics, Technical University of Denmark, DK-2800 Kgs. Lyngby, Denmark
| | - M Nocente
- Department of Physics, University of Milano-Bicocca, 20126 Milano, Italy
| | - J Rasmussen
- Department of Physics, Technical University of Denmark, DK-2800 Kgs. Lyngby, Denmark
| | - B S Schmidt
- Department of Physics, Technical University of Denmark, DK-2800 Kgs. Lyngby, Denmark
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Zhang J, Huang J, Chang JF, Wu CR, Heidbrink WW, Salewski M, Madsen B, Zhu YB, von Hellermann MG, Gao W, Xu Z, Wan B. Fast ion D-alpha measurements using a bandpass-filtered system on EAST. Rev Sci Instrum 2018; 89:10D121. [PMID: 30399922 DOI: 10.1063/1.5038828] [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] [Subscribe] [Scholar Register] [Received: 05/06/2018] [Accepted: 06/15/2018] [Indexed: 06/08/2023]
Abstract
Based on the charge exchange reaction between fast ions and a neutral beam, fast ion features can be inferred from the spectrum of Doppler-shifted Balmer-alpha light from energetic hydrogenic atoms. In order to study the interaction between instabilities and fast-ion transport, recently we extended the fast ion D-alpha (FIDA) measurements by using a combination of a bandpass filter and a photomultiplier tube (PMT) (f-FIDA). A bandpass filter selects the desired spectral band from 651 nm to 654 nm before detection by the PMT. Preliminary data from the EAST tokamak show that the active signals have been detected from reneutralized beam ions along the vertical and tangential viewing geometries. The details will be presented in this paper to primarily address the specifications and performance of f-FIDA hardware components and preliminary FIDA measurements.
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Affiliation(s)
- J Zhang
- Institute of Plasma Physics, Chinese Academy of Sciences, P.O. Box 1126, 230031 Hefei, Anhui, China
| | - J Huang
- Institute of Plasma Physics, Chinese Academy of Sciences, P.O. Box 1126, 230031 Hefei, Anhui, China
| | - J F Chang
- Institute of Plasma Physics, Chinese Academy of Sciences, P.O. Box 1126, 230031 Hefei, Anhui, China
| | - C R Wu
- Institute of Plasma Physics, Chinese Academy of Sciences, P.O. Box 1126, 230031 Hefei, Anhui, China
| | - W W Heidbrink
- Department of Physics and Astronomy, University of California, Irvine, California 92697, USA
| | - M Salewski
- Department of Physics, Technical University of Denmark, Kongens Lyngby, Denmark
| | - B Madsen
- Department of Physics, Technical University of Denmark, Kongens Lyngby, Denmark
| | - Y B Zhu
- Department of Physics and Astronomy, University of California, Irvine, California 92697, USA
| | | | - W Gao
- Institute of Plasma Physics, Chinese Academy of Sciences, P.O. Box 1126, 230031 Hefei, Anhui, China
| | - Z Xu
- Advanced Energy Research Center, Shenzhen University, Shenzhen 518060, People's Republic of China
| | - B Wan
- Institute of Plasma Physics, Chinese Academy of Sciences, P.O. Box 1126, 230031 Hefei, Anhui, China
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Madsen B, Salewski M, Huang J, Jacobsen AS, Jones O, McClements KG. Velocity-space tomography using prior information at MAST. Rev Sci Instrum 2018; 89:10D125. [PMID: 30399877 DOI: 10.1063/1.5035498] [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] [Subscribe] [Scholar Register] [Received: 04/16/2018] [Accepted: 06/18/2018] [Indexed: 06/08/2023]
Abstract
Velocity-space tomography provides a way of diagnosing fast ions in a fusion plasma by combining measurements from multiple instruments. We use a toroidally viewing and a vertically viewing fast-ion D-alpha diagnostic installed on the mega-amp spherical tokamak (before the upgrade) to perform velocity-space tomography of the fast-ion distribution function. To make up for the scarce amount of data, prior information is included in the inversions. We impose a non-negativity constraint, suppress the distribution in the velocity-space region associated with null-measurements, and encode the belief that the distribution function does not extend to energies significantly higher than those expected neoclassically. This allows us to study the fast-ion velocity distributions and the derived fast-ion densities before and after a sawtooth crash.
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Affiliation(s)
- B Madsen
- Department of Physics, Technical University of Denmark, Kgs. Lyngby, Denmark
| | - M Salewski
- Department of Physics, Technical University of Denmark, Kgs. Lyngby, Denmark
| | - J Huang
- Institute of Plasma Physics, Chinese Academy of Sciences, P.O. 1126, 230031 Hefei, Anhui, China
| | - A S Jacobsen
- Max-Planck-Institut für Plasmaphysik, Garching, Germany
| | - O Jones
- CCFE, Culham Science Centre, Abingdon, Oxfordshire OX14 3DB, United Kingdom
| | - K G McClements
- CCFE, Culham Science Centre, Abingdon, Oxfordshire OX14 3DB, United Kingdom
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Madsen B, Biel A, Kusano Y, Lilholt H, Mikkelsen L, Mishnaevsky Jr. L, Sørensen B. 37th Risø International Symposium on Materials Science. ACTA ACUST UNITED AC 2016. [DOI: 10.1088/1757-899x/139/1/011001] [Citation(s) in RCA: 1] [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: 11/11/2022]
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Skov J, Pedersen M, Holst JJ, Madsen B, Goetze JP, Rittig S, Jonassen T, Frøkiaer J, Dejgaard A, Christiansen JS. Short-term effects of liraglutide on kidney function and vasoactive hormones in type 2 diabetes: a randomized clinical trial. Diabetes Obes Metab 2016; 18:581-9. [PMID: 26910107 DOI: 10.1111/dom.12651] [Citation(s) in RCA: 92] [Impact Index Per Article: 11.5] [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: 10/25/2015] [Revised: 11/17/2015] [Accepted: 02/18/2016] [Indexed: 02/06/2023]
Abstract
AIMS To investigate the effects of a single dose of 1.2 mg liraglutide, a once-daily glucagon-like peptide-1 (GLP-1) receptor agonist, on key renal variables in patients with type 2 diabetes. METHODS The study was a placebo-controlled, double-blind, crossover trial in 11 male patients with type 2 diabetes. Measurements included (51) Cr-EDTA plasma clearance estimated glomerular filtration rate (GFR) and MRI-based renal blood flow (RBF), tissue perfusion and oxygenation. RESULTS Liraglutide had no effect on GFR [95% confidence interval (CI) -6.8 to 3.6 ml/min/1.73 m(2) ] or on RBF (95% CI -39 to 30 ml/min) and did not change local renal blood perfusion or oxygenation. The fractional excretion of lithium increased by 14% (p = 0.01) and sodium clearance tended to increase (p = 0.06). Liraglutide increased diastolic and systolic blood pressure (3 and 6 mm Hg) and heart rate (2 beats per min; all p < 0.05). Angiotensin II (ANG II) concentration decreased by 21% (p = 0.02), but there were no effects on other renin-angiotensin system components, atrial natriuretic peptides (ANPs), methanephrines or excretion of catecholamines. CONCLUSIONS Short-term liraglutide treatment did not affect renal haemodynamics but decreased the proximal tubular sodium reabsorption. Blood pressure increased with short-term as opposed to long-term treatment. Catecholamine levels were unchanged and the results did not support a GLP-1-ANP axis. ANG II levels decreased, which may contribute to renal protection by GLP-1 receptor agonists.
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Affiliation(s)
- J Skov
- Department of Endocrinology and Internal Medicine, Aarhus University Hospital, Aarhus, Denmark
- Novo Nordisk A/S, Bagsvaerd, Denmark
| | - M Pedersen
- Comparative Medicine Laboratory, Aarhus University Hospital, Aarhus, Denmark
- Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - J J Holst
- Department of Biomedical Sciences, NNF Center for Basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark
- Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - B Madsen
- Department of Nephrology, Aarhus University Hospital, Aarhus, Denmark
| | - J P Goetze
- Department of Clinical Biochemistry, University of Copenhagen, Rigshospitalet, Copenhagen, Denmark
| | - S Rittig
- Department of Pediatrics, Aarhus University Hospital, Aarhus, Denmark
| | - T Jonassen
- Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - J Frøkiaer
- Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
- Department of Clinical Physiology and Molecular Imaging, Aarhus University Hospital, Aarhus, Denmark
| | | | - J S Christiansen
- Department of Endocrinology and Internal Medicine, Aarhus University Hospital, Aarhus, Denmark
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Pham H, Song G, Badiozamani K, Yao M, Corman J, Hsi R, Madsen B. Five-year Outcome of Stereotactic Hypofractionated Accurate Radiotherapy of the Prostate (SHARP) for Patients with Low-risk Prostate Cancer. Int J Radiat Oncol Biol Phys 2010. [DOI: 10.1016/j.ijrobp.2010.07.168] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
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Pedersen EB, Madsen B, Danielsen H, Jespersen B. Experience with percutaneous transluminal renal angioplasty in renovascular hypertension. Acta Med Scand Suppl 2009; 714:23-7. [PMID: 2953176 DOI: 10.1111/j.0954-6820.1986.tb08963.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Percutaneous transluminal renal angioplasty (PTRA) was attempted in 17 patients with a diastolic blood pressure greater than or equal to 95 mmHg in spite of treatment with two or three antihypertensive drugs in combination and unilateral or bilateral renal artery stenosis with a reduction of vessel diameter to less than 25%. PTRA resulted in a dilatation of the stenosis in 12 patients. After an observation period of at least 6 months 2 patients were cured, 7 improved and 3 unchanged. Renal vein renin ratio (RVRR) was determined in the last 9 of these patients but was unknown when PTRA was done. RVRR was higher than 1.5 in 5 patients of whom one was cured and 4 improved and less than 1.5 in 4 of whom one was improved and 3 unchanged. No persistent complications were observed after PTRA. It can be concluded that PTRA is an effective antihypertensive treatment in several patients with renovascular hypertension, and a RVRR greater than 1.5 suggests a favourable outcome with regard to blood pressure regulation.
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Hsi R, Vali F, Parsai H, Garver E, Madsen B, Pham H, Song G, Badiozamani K, Cho P. Evaluation of Interfraction and Intrafraction Prostate Motion during the Treatment of Prostate Cancer using the Calypso 4D Localization System. Int J Radiat Oncol Biol Phys 2008. [DOI: 10.1016/j.ijrobp.2008.06.1055] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Pham H, Presser J, Esagui L, Lawrence T, Hsi R, Madsen B, Song G, Hunter M, Badiozamani K, Taylor E. Intrafractional stability of frameless fractionated stereotactic radiation therapy or IMRT using implanted cranial fiducials. Int J Radiat Oncol Biol Phys 2004. [DOI: 10.1016/j.ijrobp.2004.07.628] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Sennels HP, Sand JC, Madsen B, Lauritzen JB, Fenger M, Jørgensen HL. Association between polymorphisms of apolipoprotein E, bone mineral density of the lower forearm, quantitative ultrasound of the calcaneus and osteoporotic fractures in postmenopausal women with hip or lower forearm fracture. Scand J Clin Lab Invest 2004; 63:247-58. [PMID: 12940632 DOI: 10.1080/00365510310001177] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [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: 10/26/2022]
Abstract
A genetic contribution to the development of osteoporosis is well documented. Although the association between the common allelic variation of apolipoprotein E (APOE), fracture risk, bone loss and bone mineral density (BMD) has been examined in several studies, the results of these investigations are contradictory. The aim of this study was to examine the association between polymorphisms of APOE, BMD of the lower forearm, quantitative ultrasound of the calcaneus and osteoporotic fractures in a population of postmenopausal women with hip or lower forearm fractures admitted to a department of orthopaedic surgery and age-matched controls from the population register. The APOE genotypes of 327 women were studied: 73 with lower forearm fractures, 43 with hip fractures and 211 age-matched controls. The participants were not receiving antiosteoporotic treatment. Polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) was used to detect the APOE genotypes. Quantitative ultrasound was measured at the calcaneus. Bone mineral density (BMD) of the lower forearm was measured with dual-energy X-ray absorptiometry. The distributions of genotype frequencies in this study were: E2/E2: 0.3%; E2/E3: 16.5%; E2/E4: 2.5%; E3/E3: 54.7%; E3/E4: 24.2%; E4/E4: 1.8%. All subpopulations were in Hardy-Weinburg equilibrium. There was no association between bone mass parameters and the APOE allele groups. Logistic regression analysis did not show any association between fractures and APOE allele groups. In conclusion, this study showed no association between bone mass parameters (BMD, speed of sound (SOS), broadband ultrasound attenuation (BUA)), hip or lower forearm fracture and APOE genotypes in a population of postmenopausal women and age-matched controls.
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Affiliation(s)
- H P Sennels
- Department of Clinical Biochemistry, Hvidovre University Hospital, Denmark.
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Pham H, Myers L, Presser J, Madsen B, Esagui L, Hsi R. Intrafraction prostate stability in stereotactic radiotherapy of the prostate. Int J Radiat Oncol Biol Phys 2003. [DOI: 10.1016/s0360-3016(03)01217-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Esbensen B, Andersen C, Hoestrup H, Joergensen L, Lambaek K, Madsen B, Moeller T, Taps E. 1291 The study registration project — Danish studies of people with cancer from a nursing perspective. EJC Suppl 2003. [DOI: 10.1016/s1359-6349(03)91317-6] [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: 10/26/2022] Open
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Jørgensen HL, Madsen JS, Madsen B, Saleh MMA, Abrahamsen B, Fenger M, Lauritzen JB. Association of a common allelic polymorphism (C677T) in the methylene tetrahydrofolate reductase gene with a reduced risk of osteoporotic fractures. A case control study in Danish postmenopausal women. Calcif Tissue Int 2002; 71:386-92. [PMID: 12232679 DOI: 10.1007/s00223-001-2126-3] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.2] [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: 11/19/2001] [Accepted: 03/29/2002] [Indexed: 11/26/2022]
Abstract
Twin studies indicate a substantial genetic component in the development of osteoporosis. One of the latest studied candidate genes is the one coding for methylene tetrahydrofolate reductase (MTHFR) (C677T) in which a point mutation gives rise to a thermolabile variant of MTHFR. The aim of this study was to investigate the influence of this mutation on peripheral measures of bone density and on the odds ratios (OR) for hip and lower forearm fracture in a case control study of Danish postmenopausal women. A total of 74 women with lower forearm fracture, 41 women with hip fracture, and 207 age-matched controls were included. All had broadband ultrasound attenuation (BUA) and speed of sound (SOS) measured at the heel as well as bone mineral density (BMD) measured by dual X-ray absorptiometry at the distal forearm. The MTHFR (C677T) genotypes were determined using polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP). Only 2 of 21 individuals with the TT genotype had sustained a fracture as opposed to 46 of 142 with the CT genotype and 67 of 159 with the CC genotype (P = 0.007). Using logistic regression, the following odds ratios were found when comparing the individuals homozygotic for the C-allele with those homozygotic for the T-allele: lower forearm fracture OR = 3.93 (1.25; 12.40, P = 0.02), hip fracture OR = 6.99 (l.35; 36.92, P = 0.02) and the fractures combined OR = 4.33 (1.73; 10.81, P = 0.002). In this study, the MTHFR (C677T) genotypes were not significantly associated with BMD at the lower forearm or with ultrasound parameters measured at the calcaneus. However, a significant increase in the odds ratio of fracture was found for the wild-type C-allele.
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Affiliation(s)
- H L Jørgensen
- Department of Clinical Biochemistry, Hvidovre University Hospital, Kettegaard Allé 30, 2650 Hvidovre, Denmark.
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Riekel C, Madsen B, Knight D, Vollrath F. X-ray diffraction on spider silk during controlled extrusion under a synchrotron radiation X-ray beam. Biomacromolecules 2002; 1:622-6. [PMID: 11710191 DOI: 10.1021/bm000047c] [Citation(s) in RCA: 86] [Impact Index Per Article: 3.9] [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: 11/28/2022]
Abstract
The structure of a single thread of Nephila edulis silk has been studied by in situ X-ray diffraction from a living spider. A systematic increase of orientational order with increasing silking speed up to 40 mm s-1 was observed. Within a few mm from the spinnerets exit, crystalline domains with a beta-poly(L-alanine) structure were observed. The data also suggest an increase in crystalline fraction in the immediate vicinity of the spigot exit.
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Affiliation(s)
- C Riekel
- European Synchrotron Radiation Facility, B.P. 220, F-38043 Grenoble, France
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Abstract
We studied the mechanical properties of dragline threads of the edible golden silk spider Nephila edulis that are produced under spinning speeds ranging from 0.1 to 400 mm s(-1) and temperatures ranging from 5 to 40 degrees C. These conditions affected the silk in all of the mechanical traits we tested (strain at breaking, breaking energy, initial Young's modulus and point of yielding). We argue that both trade-offs (between mechanical properties) and constraints (in the manufacturing process) have a large role in defining spider silk fibres.
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Affiliation(s)
- F Vollrath
- Department of Zoology, Universitetsparken B135, 8000 Aarhus C, Denmark.
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Abstract
The breast carcinoma cell line T47D was tested for 17 beta-estradiol (E2) mediated regulation of vasoactive intestinal polypeptide receptor type-1 (VPAC1) expression. E2 was found to downregulate the mRNA level. The number of VIP binding sites was reduced 66% on treatment with E2 for 72 h. Experiments with cycloheximide suggested that the effect was independent (at least partly so) of protein synthesis. Experiments with the transcriptional inhibitor, actinomycin D, showed that E2 did not influence the VPAC1 mRNA halflife. Both of two antiestrogens, ICI 182,780 and 4-hydroxy-tamoxifen, mediated a concentration dependent inhibition of the effect of E2 on the mRNA level. Transient transfection with reporter-gene constructs containing various portions of the VPAC1 5'-flanking sequence revealed the most proximal 100 bp to be essential for the basal transcriptional activity. However, E2 did not influence the expression of the reporter gene using up to 3,250 bp of the VPAC1 5'-flanking region.
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Affiliation(s)
- B Madsen
- Department of Clinical Biochemistry, Bispebjerg University Hospital, DK-2400 Copenhagen, NV, Denmark
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Madsen B, Georg B, Madsen MW, Fahrenkrug J. Estradiol down regulates expression of vasoactive intestinal polypeptide receptor type-1 in breast cancer cell lines. Mol Cell Endocrinol 2001; 172:203-11. [PMID: 11165054 DOI: 10.1016/s0303-7207(00)00341-5] [Citation(s) in RCA: 8] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Three breast carcinoma cell lines were tested for 17beta-estradiol (E(2)) mediated regulation of vasoactive intestinal polypeptide receptor type-1 (VPAC(1)) expression. In all three, E(2) was found to down-regulate the mRNA level. We studied T47D cells in more details and found a 25 and 70% decrease in the VPAC(1) mRNA level upon 7 and 48 h of E(2) treatment, respectively. The number of vasoactive intestinal polypeptide (VIP) binding sites was reduced 66% upon treatment with E(2) for 72 h. After cycloheximide pretreatment, the E(2) mediated mRNA reduction was attenuated from 50% to 25% after 24 h suggesting the effect to be at least partly independent of protein synthesis. Experiments with the transcriptional inhibitor actinomycin D showed that E(2) did not influence the VPAC(1) mRNA half-life while nuclear run-on experiments indicated that E(2) decreased the VPAC(1) transcription rate. Two antiestrogens: ICI 182780 (ICI) and 4-hydroxy-tamoxifen (4-OHT) mediated a concentration dependent inhibition of E(2)'s effect on the mRNA level. Transient transfection with reporter-gene constructs containing various portions of the VPAC(1) 5'-flanking sequence revealed the most proximal 100 bp to be essential for the basal transcriptional activity. However, E(2) did not influence the expression of the reporter gene using up to 3250 bp of the VPAC(1) 5'-flariking region.
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Affiliation(s)
- B Madsen
- Department of Clinical Biochemistry, Bispebjerg Hospital, University of Copenhagen NV, Bispebjerg Bakke 23, Dk-2400, Copenhagen, Denmark
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Jones D, Madsen B. Regarding Nay and Gupta, IJROBP 2000;46:507-513. Int J Radiat Oncol Biol Phys 2000; 48:907-8. [PMID: 11183737 DOI: 10.1016/s0360-3016(00)00680-5] [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] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Abstract
CO2 and N2 anesthetized Nephila spiders produced dragline silk with mechanical properties that differed from control silk as a function of time under anesthesia. Silk from CO2 spiders had a significantly lower breaking strain and breaking energy, significantly higher initial modulus, and marginally lower breaking stress. At the onset of anesthesia the silk diameter became highly variable. During deep anesthesia silk either became thinner or retained cross-section but fibrillated.
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Affiliation(s)
- B Madsen
- Department of Zoology, Universitetsparken B135, Aarhus C, Denmark
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23
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Bo J, Schrøder H, Kristinsson J, Madsen B, Szumlanski C, Weinshilboum R, Andersen JB, Schmiegelow K. Possible carcinogenic effect of 6-mercaptopurine on bone marrow stem cells: relation to thiopurine metabolism. Cancer 1999. [PMID: 10491537 DOI: 10.1002/(sici)1097-0142(19990915)86] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
BACKGROUND 6-Mercaptopurine (6MP) has been regarded as nonleukemogenic, even though the cytotoxicity of 6MP depends on the incorporation of 6-thioguanine nucleotides (6TGN) into DNA. In hematopoietic cells this pathway competes with S-methylation catalyzed by thiopurine methyltransferase (TPMT). However, methylated 6MP metabolites inhibit purine de novo synthesis and thus may enhance incorporation of 6TGN into DNA. Approximately 10% of white individuals have low TPMT activity as a result of polymorphisms in the TPMT gene. The authors attempted to test the hypothesis that the degree of DNA damage during 6MP therapy might reflect variations in 6MP metabolism and pharmacokinetics. METHODS The authors measured TPMT activity as well as erythrocyte levels of 6TGN (E-6TGN) and methylated 6MP metabolites (E-MeMP) during 6MP therapy in 439 children with acute lymphoblastic leukemia, 5 of whom later developed secondary myelodysplasia or acute myeloid leukemia (sMDS/AML). RESULTS The patients who developed sMDS/AML had significantly lower TPMT activity compared with the remaining patients (P = 0.03). The 55 patients with TPMT activity <14 U/mL red blood cells (RBC) (antimode of the bimodal distribution) had a 5-year risk of sMDS/AML of 9 +/- 6% versus 1 +/- 1% for the remaining patients (P = 0.002). Cox regression analysis identified TPMT activity and E-MeMP level as the strongest predictors of risk for sMDS/AML (global P value = 0.02). Patients with low TPMT activity and high E-MeMP levels had the highest risk. All 5 patients with sMDS/AML had E-6TGN and/or E-MeMP levels > the 90% percentiles or had TPMT activity < 14 U/mL RBC. CONCLUSIONS These data demonstrate an increased leukemogenic risk when 6MP is administered with other cytotoxic agents in patients with low TPMT activity, and indicate that not only high 6TGN levels but also high levels of methylated metabolites may lead to DNA damage.
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Affiliation(s)
- J Bo
- The Laboratory for Pediatric Oncology, The Pediatric Clinic II, The National University Hospital, Copenhagen, Denmark
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24
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Bo J, Schrøder H, Kristinsson J, Madsen B, Szumlanski C, Weinshilboum R, Andersen JB, Schmiegelow K. Possible carcinogenic effect of 6-mercaptopurine on bone marrow stem cells: relation to thiopurine metabolism. Cancer 1999. [PMID: 10491537 DOI: 10.1002/(sici)1097-0142(19990915)86: 6<1080: : aid-cncr26>3.0.co; 2-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
BACKGROUND 6-Mercaptopurine (6MP) has been regarded as nonleukemogenic, even though the cytotoxicity of 6MP depends on the incorporation of 6-thioguanine nucleotides (6TGN) into DNA. In hematopoietic cells this pathway competes with S-methylation catalyzed by thiopurine methyltransferase (TPMT). However, methylated 6MP metabolites inhibit purine de novo synthesis and thus may enhance incorporation of 6TGN into DNA. Approximately 10% of white individuals have low TPMT activity as a result of polymorphisms in the TPMT gene. The authors attempted to test the hypothesis that the degree of DNA damage during 6MP therapy might reflect variations in 6MP metabolism and pharmacokinetics. METHODS The authors measured TPMT activity as well as erythrocyte levels of 6TGN (E-6TGN) and methylated 6MP metabolites (E-MeMP) during 6MP therapy in 439 children with acute lymphoblastic leukemia, 5 of whom later developed secondary myelodysplasia or acute myeloid leukemia (sMDS/AML). RESULTS The patients who developed sMDS/AML had significantly lower TPMT activity compared with the remaining patients (P = 0.03). The 55 patients with TPMT activity <14 U/mL red blood cells (RBC) (antimode of the bimodal distribution) had a 5-year risk of sMDS/AML of 9 +/- 6% versus 1 +/- 1% for the remaining patients (P = 0.002). Cox regression analysis identified TPMT activity and E-MeMP level as the strongest predictors of risk for sMDS/AML (global P value = 0.02). Patients with low TPMT activity and high E-MeMP levels had the highest risk. All 5 patients with sMDS/AML had E-6TGN and/or E-MeMP levels > the 90% percentiles or had TPMT activity < 14 U/mL RBC. CONCLUSIONS These data demonstrate an increased leukemogenic risk when 6MP is administered with other cytotoxic agents in patients with low TPMT activity, and indicate that not only high 6TGN levels but also high levels of methylated metabolites may lead to DNA damage.
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Affiliation(s)
- J Bo
- The Laboratory for Pediatric Oncology, The Pediatric Clinic II, The National University Hospital, Copenhagen, Denmark
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25
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Bo J, Schrøder H, Kristinsson J, Madsen B, Szumlanski C, Weinshilboum R, Andersen JB, Schmiegelow K. Possible carcinogenic effect of 6-mercaptopurine on bone marrow stem cells: relation to thiopurine metabolism. Cancer 1999; 86:1080-6. [PMID: 10491537 DOI: 10.1002/(sici)1097-0142(19990915)86:6<1080::aid-cncr26>3.0.co;2-5] [Citation(s) in RCA: 110] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
BACKGROUND 6-Mercaptopurine (6MP) has been regarded as nonleukemogenic, even though the cytotoxicity of 6MP depends on the incorporation of 6-thioguanine nucleotides (6TGN) into DNA. In hematopoietic cells this pathway competes with S-methylation catalyzed by thiopurine methyltransferase (TPMT). However, methylated 6MP metabolites inhibit purine de novo synthesis and thus may enhance incorporation of 6TGN into DNA. Approximately 10% of white individuals have low TPMT activity as a result of polymorphisms in the TPMT gene. The authors attempted to test the hypothesis that the degree of DNA damage during 6MP therapy might reflect variations in 6MP metabolism and pharmacokinetics. METHODS The authors measured TPMT activity as well as erythrocyte levels of 6TGN (E-6TGN) and methylated 6MP metabolites (E-MeMP) during 6MP therapy in 439 children with acute lymphoblastic leukemia, 5 of whom later developed secondary myelodysplasia or acute myeloid leukemia (sMDS/AML). RESULTS The patients who developed sMDS/AML had significantly lower TPMT activity compared with the remaining patients (P = 0.03). The 55 patients with TPMT activity <14 U/mL red blood cells (RBC) (antimode of the bimodal distribution) had a 5-year risk of sMDS/AML of 9 +/- 6% versus 1 +/- 1% for the remaining patients (P = 0.002). Cox regression analysis identified TPMT activity and E-MeMP level as the strongest predictors of risk for sMDS/AML (global P value = 0.02). Patients with low TPMT activity and high E-MeMP levels had the highest risk. All 5 patients with sMDS/AML had E-6TGN and/or E-MeMP levels > the 90% percentiles or had TPMT activity < 14 U/mL RBC. CONCLUSIONS These data demonstrate an increased leukemogenic risk when 6MP is administered with other cytotoxic agents in patients with low TPMT activity, and indicate that not only high 6TGN levels but also high levels of methylated metabolites may lead to DNA damage.
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Affiliation(s)
- J Bo
- The Laboratory for Pediatric Oncology, The Pediatric Clinic II, The National University Hospital, Copenhagen, Denmark
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26
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Nørgaard BL, Wachtell K, Christensen PD, Madsen B, Johansen JB, Christiansen EH, Graff O, Simonsen EH. Efficacy and safety of intravenously administered dofetilide in acute termination of atrial fibrillation and flutter: a multicenter, randomized, double-blind, placebo-controlled trial. Danish Dofetilide in Atrial Fibrillation and Flutter Study Group. Am Heart J 1999; 137:1062-9. [PMID: 10347332 DOI: 10.1016/s0002-8703(99)70363-7] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
BACKGROUND This study was designed to assess the efficacy and safety of intravenous dofetilide in acute termination of atrial fibrillation (AF) and flutter (AFL). Dofetilide, an investigational class III antiarrhythmic agent, selectively inhibits the rapid component of the delayed rectifier potassium current, thus prolonging the effective refractory period and duration of the action potential. Dofetilide can be administered intravenously and has a rapid onset of electrophysiologic action. METHODS AND RESULTS Ninety-six patients with AF (n = 79) or AFL (n = 17) with a median arrhythmia duration of 62 days (range 1 to 180) were randomized to placebo (n = 30) or 8 micrograms/kg IV dofetilide (n = 66) over 30 minutes. Conversion was defined as termination of the atrial arrhythmia within 3 hours from the start of infusion. The conversion rate was 30.3% after dofetilide and 3.3% after placebo (P <.006). Conversion rate was higher in AFL than in AF: 64% versus 24% (P =. 012). In nonconverters, there was no statistically significant difference between the change in heart rate among the dofetilide-treated compared with the placebo-treated patients (P =. 42). Torsade de pointes ventricular tachycardia developed in 2 patients (3%). In both patients, drug infusion was discontinued before the event because of prolongation of the QT interval. CONCLUSIONS Intravenous dofetilide is effective in acute termination of AF and AFL of medium duration, with a particularly high efficacy rate in AFL. A small but serious risk of proarrhythmia must be anticipated.
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Pehrson S, Wedekind T, Madsen B, Holm M, Res JC, Olsson SB. The optimal oesophageal pacing technique--the importance of body position, interelectrode spacing, electrode surface area, pacing waveform and intra-oesophageal local anaesthesia. Scand Cardiovasc J Suppl 1999; 33:103-9. [PMID: 10225312 DOI: 10.1080/14017439950141911] [Citation(s) in RCA: 8] [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: 10/16/2022]
Abstract
In order to improve the technique of transoesophageal atrial stimulation (TAS), the effects of body position, interelectrode spacing and electrode surface area on pacing threshold were assessed in two substudies. The effects of intra-oesophageal local anaesthesia and of two different pacing wave configurations on pacing threshold and discomfort were also assessed. Substudy I comprised 16 subjects (3 patients with a history of paroxysmal supraventricular tachycardia and 13 healthy volunteers) and substudy II comprised 16 healthy volunteers. TAS was performed using a hexapolar luminal prototype oesophageal electrode catheter. In substudy I bipolar pacing was performed in the semi-supine and left decubitus body positions for different pulse durations (20, 10, 6 and 2 ms), interelectrode pole distances (10 to 24 mm) and electrode pole surface areas (0.22 to 0.66 cm2). In substudy II TAS was performed with square wave and triangular waveform pulses after intra-oesophageal saline and lidocaine 20 mg/ml. These solutions were given in random order. Neither the interelectrode distance nor electrode surface areas had any significant influence on pacing thresholds. Stimulation thresholds were not affected by body position. Intraoesophageal lidocaine did not affect the discomfort experienced. Peak pacing thresholds using a triangular waveform were significantly higher than thresholds using a square waveformn (p < 0.001). The optimal pacing technique for TAS remains to be defined. The TAS-induced pain is probably not generated from the oesophageal mucous membrane. There is a significant difference in pacing thresholds between triangular and square waveforms.
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Affiliation(s)
- S Pehrson
- Department of Cardiology, University Hospital, Lund, Sweeden
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28
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Madsen B, Shao ZZ, Vollrath F. Variability in the mechanical properties of spider silks on three levels: interspecific, intraspecific and intraindividual. Int J Biol Macromol 1999; 24:301-6. [PMID: 10342779 DOI: 10.1016/s0141-8130(98)00094-4] [Citation(s) in RCA: 165] [Impact Index Per Article: 6.6] [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: 11/24/2022]
Abstract
The mechanical characteristics of dragline silks collected from a range of spiders drawn from the Argiopidae, Tetragnathidae, Theridiidae and Pisauridae displayed significant inter- and intraspecific differences. Dragline silks of the same species could show considerable variability probably dependent upon spider condition: starvation, for example, lead to decreased breaking elongation in Nephila edulis. Environmental conditions such as reeling speed affected silk properties such that (i) breaking elongation decreased, (ii) breaking stress increased and (iii) Young's modulus increased with increasing reeling speed. However, N. edulis and Araneus diadematus responded differently to the reeling speed treatments suggesting differences in basic silk properties.
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Affiliation(s)
- B Madsen
- Department of Zoology, Aarhus C, Denmark
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29
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Moe PJ, Holen A, Glomstein A, Madsen B, Hellebostad M, Stokland T, Nygaard R, Wefring KW, Steen-Johnsen J, Nielsen B, Hapnes C, Børsting S. [Adults treated as children for acute lymphocytic leukemia--methotrexate, late effects and quality of life]. Tidsskr Nor Laegeforen 1999; 119:499-503. [PMID: 10081372] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/11/2023] Open
Abstract
From 1975 to 1980, 153 Norwegian children were diagnosed with acute lymphocytic leukaemia. In 1995, all 98 survivors were studied and compared to matched family controls. 132 children were treated with the national protocol. Of these, 93 (70.5%) were survivors at the time of the study. The remaining five survivors were treated with different treatment schemes. The national protocol included methotrexate infusions combined with intrathecal methotrexate as prophylactics against neuroleukaemia, instead of the irradiation. Neither doxorubicin nor cyclophosphamide were included. In this study, a questionnaire was used that covered demographic data, quality of life, and medical information the response rates were 96% (94 persons) for survivors and 92% (90 persons) for family controls. Information was also obtained for the remaining four survivors. No significant differences were found between survivors and controls with regard to quality of life and demographics, with one exception, Somatisation on the GHQ-28. Hospital records of all patients were checked for possible late effects. One case of serious sequela (hemiparesis during therapy) was found, probably related to methotrexate therapy. Seven other serious, possible sequelae were recorded, but probably not related to methotrexate. There were no cases of secondary malignant neoplasm.
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Affiliation(s)
- P J Moe
- Barneklinikken Regionsykehuset i Trondheim
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Madsen B, Georg B, Vissing H, Fahrenkrug J. Retinoic acid down-regulates the expression of the vasoactive intestinal polypeptide receptor type-1 in human breast carcinoma cell lines. Cancer Res 1998; 58:4845-50. [PMID: 9809989] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
Four breast carcinoma cell lines (T47D, ZR-75-1, MDA-MB-231, and MCF-7) were tested for regulation of the expression of vasoactive intestinal polypeptide receptor type-1 (VIP-R1). In all four cell lines, retinoic acid (RA) treatment caused a fast and marked decrease in VIP-R1 mRNA level as examined by Northern blots. Cycloheximide pretreatment attenuated the effect from 3- to 2-fold, indicating that existing proteins can mediate the decreasing effect of RA, but to attain the maximal effect new protein synthesis might be needed. Transcriptional inhibition with Actinomyocin D showed that RA did not influence the VIP-R1 mRNA half-life, indicating that the decreasing effect of RA on the mRNA level is due to transcriptional inhibition. In agreement with the observations on mRNA level, we found that the VIP receptor number was reduced 3-fold from 88 to 32 fmol/10(6) cells in T47D cells and from 222 to 73 fmol/10(6) cells in MDA-MB-231 cells upon RA treatment for 72 h. The promoter and 5'-flanking region of the VIP-R1 gene were cloned from a human placental cosmid library, and 2.5 kb were sequenced to search for regulatory elements. Our results, therefore, imply that the regulation of VIP-R1 gene expression by RA could have a role in human mammary tumor biology.
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Affiliation(s)
- B Madsen
- Department of Clinical Biochemistry, Bispebjerg University Hospital, Copenhagen, Denmark.
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Hansen LH, Madsen B, Teisner B, Nielsen JH, Billestrup N. Characterization of the inhibitory effect of growth hormone on primary preadipocyte differentiation. Mol Endocrinol 1998; 12:1140-9. [PMID: 9717840 DOI: 10.1210/mend.12.8.0154] [Citation(s) in RCA: 68] [Impact Index Per Article: 2.6] [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: 11/19/2022] Open
Abstract
GH exerts adipogenic activity in several preadipocyte cell lines, whereas in primary rat preadipocytes, GH has an antiadipogenic activity. To better understand the molecular mechanism involved in adipocyte differentiation, the expression of adipocyte-specific genes was analyzed in differentiating preadipocytes in response to GH. We found that the expression of both adipocyte determination and differentiation factor 1 (ADD1) and peroxisome proliferator activated receptor gamma(PPARgamma) was induced in preadipocytes during differentiation. In the presence of GH, which markedly inhibited triglyceride accumulation, no reduction in the expression level of ADD1 was observed in response to GH, whereas there was a 50% reduction in the expression of PPARgamma. The DNA binding activity of the PPARgamma/retinoid X receptor-alpha(RXRalpha) to the ARE7 element from the aP2 gene was also reduced by approximately 50% in response to GH. GH inhibited the expression of late markers of adipocyte differentiation, fatty acid synthase, aP2, and hormone-sensitive lipase by 70-80%. The antiadipogenic effect of GH was not affected by the mitogen-activated protein (MAP) kinase/ extracellular-regulated protein (ERK) kinase inhibitor PD 98059, indicating that the mitogen-activated protein kinase pathway was not involved in GH inhibition of preadipocyte differentiation. The expression of preadipocyte factor-1/fetal antigen 1 was decreased during differentiation, and GH treatment prevented this down-regulation of Pref1/FA1. A possible role for Pref-1/FA1 in mediating the antiadipogenic effect of GH was indicated by the observation that FA1 inhibited differentiation as effectively as GH. These data suggest that GH exerts its inhibitory activity in adipocyte differentiation at a step after the induction of ADD1 but before the induction of genes required for terminal differentiation.
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Affiliation(s)
- L H Hansen
- Hagedorn Research Institute, Gentofte, Denmark
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Jahnukainen K, Salmi TT, Kristinsson J, Müller J, Madsen B, Gustafsson G. The clinical indications for identical pathogenesis of isolated and non-isolated testicular relapses in acute lymphoblastic leukaemia. Acta Paediatr 1998; 87:638-43. [PMID: 9686656 DOI: 10.1080/080352598750014049] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
In the present population-based study, we compared the clinical data of testicular relapses with and without concurrent bone marrow relapse and clinical data of the relapses in other locations among boys with acute lymphoblastic leukaemia (ALL), in order to study the possible evidence of early sequestration and local regulation of leukaemic lymphoblast in the testis of humans. The results suggest that the pathogenesis of isolated testicular relapse (T) and testicular relapse with a concurrent bone marrow relapse (T + BM) is likely to be similar. Isolated and non-isolated testicular relapses appeared late after the achievement of remission (T 34 +/- 16 months, T + BM 32 +/- 15 months) in ALL compared to relapses in other locations (CNS 23 +/- 11 months, BM 25 +/- 19 months). The better prognosis after testicular relapses (estimated second event free survival probability, 2-EFS: T 0.63, T + BM 0.32) compared to bone marrow relapse (2-EFS: BM 0.13) further suggests that testicular relapse with a concurrent bone marrow relapse possibly originates from the isolated testicular relapse, and that the isolated testicular relapse is a separate entity and not a manifestation of systemic recurrence. Higher frequencies of isolated and non-isolated testicular relapses (T 9%, T + BM 5%) were observed among boys with onset of ALL in early puberty (10-12 y) compared to those among younger (T 4%, T + BM 2%) and older (T 0%, T + BM 0%) boys. The late occurrence, the possible association with hormonal maturation and the good prognosis after testicular relapses suggest a possible local regulation of the residual leukaemic lymphoblast in human testis.
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Affiliation(s)
- K Jahnukainen
- Nordic Society of Paediatric Haematology and Oncology, Finland
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Boguszewski M, Albertsson-Wikland K, Aronsson S, Gustafsson J, Hagenäs L, Westgren U, Westphal O, Lipsanen-Nyman M, Sipilä I, Gellert P, Müller J, Madsen B. Growth hormone treatment of short children born small-for-gestational-age: the Nordic Multicentre Trial. Acta Paediatr 1998; 87:257-63. [PMID: 9560030 DOI: 10.1080/08035259850157282] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The aims of this study were to evaluate the efficacy and safety of different doses of growth hormone (GH) treatment in prepubertal short children born small-for-gestational-age (SGA). Forty-eight children born SGA from Sweden, Finland, Denmark and Norway were randomly allocated to three groups: a control group of 12 children received no treatment for 2 y, one group was treated with GH at 0.1 IU/kg/d (n=16), and one group was treated with GH at 0.2 IU/kg/d (n=20). In total 42 children completed 2 y of follow-up, and 24 children from the treated groups completed 3 y of treatment. Their mean (SD) age at the start of the study was 4.69 (1.61) y and their mean (SD) height was -3.16 (0.70) standard deviation scores (SDS). The children remained prepubertal during the course of the study. No catch-up growth was observed in the untreated group, but a clear dose-dependent growth response was found in the treated children. After the third year of treatment, the group receiving the higher dose of GH, achieved their target height. The major determinants of the growth response were the dose of GH used, the age at the start of treatment (the younger the child, the better the growth response) and the family-corrected individual height deficit (the higher the deficit, the better the growth response). Concentration of insulin-like growth factor-I (IGF-I) and IGF-binding protein-3 increased during treatment. An increase in insulin levels was found without negative effects on fasting glucose levels or glycosylated haemoglobin levels. GH treatment was well tolerated. In conclusion, short prepubertal children born SGA show a dose-dependent growth response to GH therapy, and their target height SDS can be achieved within 3 y of treatment given GH at 0.2 IU/kg/d. However, the long-term benefit of different regimens of GH treatment in children born SGA remains to be established.
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Affiliation(s)
- M Boguszewski
- Department of Paediatrics at the University of Göteborg, Sweden
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Moe PJ, Holen A, Glomstein A, Madsen B, Hellebostad M, Stokland T, Wefring KW, Steen-Johnsen J, Nielsen B, Howlid H, Børsting S, Hapnes C. Long-term survival and quality of life in patients treated with a national all protocol 15-20 years earlier: IDM/HDM and late effects? Pediatr Hematol Oncol 1997; 14:513-24. [PMID: 9383804 DOI: 10.3109/08880019709030908] [Citation(s) in RCA: 30] [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: 02/05/2023]
Abstract
In a follow-up matched control study the 93 (70.5%) survivors of 132 children treated with a national protocol for acute lymphoblastic leukemia (ALL) and 5 survivors of the other 21 cases of ALL in childhood diagnosed in the same period were evaluated. Thus it was also a population-based study. The national treatment protocol was used in the period 1975-1980. Methotrexate (MTX) infusions combined with intrathecal MTX were used as prophylaxis against neuroleukemia instead of irradiation. Neither doxorubicin (Adriamycin) nor cyclophosphamide was used in the protocol. A questionnaire covering demographic data, number of offspring, learning problems, level of athletic performance, education, and work status as well as medical information was used. Forms were received from 94 (96%) of the 98 adult surviving cases and corresponding controls in the family. Interviews were performed in the remaining four cases (4%). There were no statistical differences between the two groups with respect to physical and mental health and quality of life. Hospital records of all patients were also checked for possible late effects. There was no definite case of secondary malignant neoplasm; however, there was one case of prolactinoma and only one case of serious sequelae (hemiparesis during therapy), probably due to intrathecal and intravenous MTX.
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Affiliation(s)
- P J Moe
- Department of Pediatrics, Regionsykehuset i Trondheim, Norway
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35
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Hansen O, Pfeiffer P, Madsen B, Andersen I, Hansen B, Mathiesen B. Sustained-release metoclopramide plus methylprednisolone versus placebo plus methylprednisolone as antiemetic prophylaxis during non-cisplatin chemotherapy. A randomized double-blind cross-over trial. Acta Oncol 1996; 35:57-61. [PMID: 8619941 DOI: 10.3109/02841869609098480] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
In a randomized double-blind cross-over trial, sustained-release metoclopramide (S) plus methylprednisolone (M) was compared with placebo (P) plus methylprednisolone as antiemetic prophylaxis during two cycles of non-cisplatin chemotherapy. S was administered as 60 mg every 12 h commencing on the evening before chemotherapy up to total of 300 mg metoclopramide in 2.5 days. Evaluation of nausea and vomiting was done by self-assessment schemes and visual analog scales. Fifty patients were included and 36 fulfilled both cycles. Mild nausea and vomiting were experienced by 81% and 83% in the S + M and P + M groups, respectively, while 42% and 39% showed complete control of nausea and vomiting during the first day of treatment. Moderate-dose S did not add to the antiemetic efficacy of M in non-cisplatin chemotherapeutic regimens.
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Affiliation(s)
- O Hansen
- Department of Oncology, Odense University Hospital, Odense, Denmark
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36
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Heegaard CW, Simonsen AC, Oka K, Kjøller L, Christensen A, Madsen B, Ellgaard L, Chan L, Andreasen PA. Very low density lipoprotein receptor binds and mediates endocytosis of urokinase-type plasminogen activator-type-1 plasminogen activator inhibitor complex. J Biol Chem 1995; 270:20855-61. [PMID: 7657671 DOI: 10.1074/jbc.270.35.20855] [Citation(s) in RCA: 91] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Very low density lipoprotein receptor (VLDL-R) was found to be expressed in bovine mammary gland and the human breast carcinoma cell line MCF-7 as an M(r) 105,000 variant, and in Chinese hamster ovary (CHO) cells transfected with human VLDL-R cDNA as an M(r) 130,000 variant. The receptor was purified by ligand affinity chromatography with immobilized M(r) 40,000 receptor-associated protein (RAP). The purified receptor was found to bind urokinase-type plasminogen activator-type-1 plasminogen activator inhibitor complex (u-PA.PAI-1), while there was no or very weak binding of active site blocked u-PA (DFP-u-PA), PAI-1 or u-PA-type-2 plasminogen activator inhibitor complex. The binding of u-PA.PAI-1 was blocked by RAP. The transfected CHO cells had an efficient, RAP-sensitive endocytosis of u-PA.PAI-1, severalfold higher than non-transfected parental CHO cells. u-PA.PAI-1 endocytosis was partially inhibited by DFP-u-PA, which blocks binding of the complex to the u-PA receptor. RAP and DFP-u-PA sensitive u-PA.PAI-1 endocytosis was also observed in MCF-7 cells, which were without detectable levels of other RAP-binding endocytosis receptors. These results show that VLDL-R represents a novel endocytosis mechanism for u-PA receptor-bound u-PA.PAI-1.
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Affiliation(s)
- C W Heegaard
- Department of Molecular Biology, University of Aarhus, Denmark
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37
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Jensen AB, Madsen B, Andersen P, Rose C. [Information to cancer patients prior to participation in clinical trials. Evaluation of a structured information program]. Ugeskr Laeger 1995; 157:1016-1020. [PMID: 7879298] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Informing patients before starting of antineoplastic treatment is important due to the legal aspects of clinical trials and the anxiety and uncertainty felt by the patients. This study evaluates a structured information programme used in a clinical trial. Thirty-four women were interviewed three months after receiving information about trial, using a tape-recorded structured interview. Results showed that the information was well remembered. The patients were glad to have brought a relative to the two consultations, and the time for deliberation in between was well received. The patients viewed written information as an important source of reinformation. The information provided was positively evaluated. Open and detailed information did not undermine the doctor-patient relationship. Instead it allowed patients to understand and participate in treatment decision and helped to reduce their pre-therapy anxiety and uncertainty. The results support expanding structured information programmes to include not only those patients asked to participate in the clinical trial, but all patients beginning longlasting cancer therapy.
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Affiliation(s)
- A B Jensen
- Onkologisk afdeling R, Odense Universitetshospital
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38
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Abstract
Brain noradrenaline takes part in the regulation of several brain functions. The formation of brain noradrenaline depends on brain tyrosine (Tyr) levels, which associates with the ratio in plasma of Tyr to other large, neutral amino acids (LNAA). Tyr metabolism has been studied in users of the new generation combined oral contraceptives (OC) and comparable controls at the follicular, mid-cycle, and luteal phases of the menstrual cycle. OC users showed significantly increased plasma Tyr transaminase activity, and significantly decreased plasma Tyr and Tyr/LNAA levels at mid-cycle and luteal phase, whereas plasma total 3-methoxy-4-hydroxyphenylglycol (MHPG) was not affected. Following an oral protein load, the area under the curve in plasma of Tyr and Tyr/LNAA in OC users at the luteal phase were 43% and 29%, respectively, of control levels. The results suggest that the decreased Tyr availability to the brain in OC users may result in a substrate-limited reduction of brain noradrenaline formation, which, secondarily, may contribute to disturbances of mood, coping mechanisms, and appetite in susceptible subjects.
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Affiliation(s)
- S E Møller
- Department of Clinical Pharmacology, St. Hans Psychiatric Hospital, Roskilde, Denmark
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39
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Abstract
Immunoreactive endothelin (ir-ET) was measured in peripheral venous plasma in 12 patients with renovascular hypertension (RVH) due to unilateral renal arterial stenosis, in 12 patients with essential hypertension (EH), and in 12 control subjects (C). In the patients with RVH, ir-ET was also measured in the aorta and in both renal veins before and 1 h after 25 mg of captopril was given orally. In peripheral venous plasma, ir-ET was the same in RVH (median 1.02 pmol/l (range 0.53-1.65)) as in EH (0.96 pmol/l (0.76-1.32)) and in C (1.00 pmol/l (0.77-1.16)). In RVH, the concentrations of ir-ET decrease from the aorta to the renal vein of both the affected (0.88 pmol/l (0.54-1.28) vs 0.68 (0.51-1.24), p < 0.01) and in the unaffected kidney (0.85 pmol/l (0.62-1.38) vs 0.78 pmol/l (0.36-1.25), p < 0.01). Renal extraction of ir-ET was the same on the affected side (15.1% (-3.7-33.2)) and on the unaffected side (11.2% (0.5-46.4)). In the aorta, ir-ET was significantly lower than in peripheral venous plasma (p < 0.05). The renal handling of ir-ET did not change in response to captopril in either the affected or unaffected kidney. It is concluded that circulating levels of ir-ET are normal in renovascular hypertension associated with unilateral renal artery stenosis and in essential hypertension. There is significant renal extraction of ir-ET which is unaffected by renal artery stenosis and captopril.
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Affiliation(s)
- S S Sørensen
- Department of Nephrology and Medicine C, Skejby Hospital, Aarhus, Denmark
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40
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Kjølseth D, Madsen B, Knudsen LM, Nørgaard JP, Djurhuus JC. Biofeedback treatment of children and adults with idiopathic detrusor instability. Scand J Urol Nephrol 1994; 28:243-7. [PMID: 7817166] [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] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
In adults and children suffering from urge, urge incontinence, frequent voidings, and nocturia, urodynamic examination often confirms the diagnosis of detrusor instability. We assessed the outcome of biofeedback therapy in 15 children aged 6-12 years and 7 adults aged 20-52 years, all with cystometrically proven detrusor instability. The detrusor pressure was visually conveyed to the patient during repeated bladder fillings. The patient was instructed to interrupt detrusor pressure increments by tensing the pelvic floor musculature. None of the children were found completely cured; however, 9 showed a marked decrease in either the number of the extent of symptoms. Two children showed moderate improvement, while 4 remained unaffected by the treatment. One adult was completely cured, 2 improved moderately, and 4 showed no improvement. None of these patients were converted to stable cystometry. Upon termination of the BF treatment a follow-up study was conducted for patients exhibiting pronounced or moderate improvement. The beneficial effect was maintained except in one case.
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Affiliation(s)
- D Kjølseth
- Urological Department K, Aarhus Municipal Hospital, Denmark
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41
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Jensen JD, Eiskjaer H, Madsen B, Egeblad M, Nielsen CB, Pedersen EB. Effect of captopril on the renal veno-arterial gradient of erythropoietin and oxygen in unilateral renal artery disease. Scand J Clin Lab Invest 1993; 53:859-65. [PMID: 8140397 DOI: 10.3109/00365519309086499] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [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: 01/29/2023]
Abstract
Twenty-nine patients with unilateral renal artery stenosis or occlusion were investigated. The veno-arterial gradient (VA-gradient) of erythropoietin (EPO), haemoglobin oxygen saturation and plasma renin activity (PRA) was determined separately in each kidney before and 1 h after angiotensin converting enzyme inhibition (ACE-inhibition). The VA-gradient of EPO and of hemoglobin oxygen saturation were the same in the affected and unaffected kidney during basal conditions. During ACE-inhibition the VA-gradient of EPO disappeared on the affected side but not on the unaffected side. A fall in s-EPO after ACE inhibition was demonstrated in the renal vein on the affected side (-1.4 U l-1, p < 0.01), in the contralateral vein (-0.8 U l-1, p < 0.01) and in the aorta (-0.6 U l-1, p < 0.01). The O2-gradients were reduced on both sides after captopril, from 10.8-7.5% (p < 0.04) on the affected side and from 10.8-9.0% (p < 0.04) on the contralateral. It is suggested that the stimulated renin-angiotensin system may be important for EPO production in the affected kidney in unilateral renal disease.
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Affiliation(s)
- J D Jensen
- Department of Medicine and Nephrology C, Skejby Hospital, Denmark
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42
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Madsen B, Glasdam S. [Is it realistic to do nursing research in a busy department?]. Vard Nord Utveckl Forsk 1993; 13:11-4. [PMID: 8122336 DOI: 10.1177/010740839301300404] [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] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
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43
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Kjølseth D, Knudsen LM, Madsen B, Nørgaard JP, Djurhuus JC. Urodynamic biofeedback training for children with bladder-sphincter dyscoordination during voiding. Neurourol Urodyn 1993; 12:211-21. [PMID: 8330044 DOI: 10.1002/nau.1930120303] [Citation(s) in RCA: 32] [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] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Neurologically normal children with recurrent urinary tract infections (UTIs), night- and daytime wetting, and urge and painful voiding may have staccato voiding due to pelvic floor contractions. The immediate effect of non-invasive urodynamic biofeedback (BF) therapy was assessed using a historical follow-up study in 31 children aged 5-15 years suffering from urodynamically proven overactive urethra during voiding. A long-term follow-up study was performed to investigate whether improvement was maintained. Twenty-four children (77.5%) benefited from the treatment. Of these 16 (51.5%) were cured, while 8 (26%) had a pronounced reduction in their symptoms. Although the flow was normalized in 17 (55%) and nearly normalized in 7 (22.5%), there was no significant correlation between subjective and objective criteria of improvement. Similarly, no relationship was found between the initial urodynamic characteristics and the treatment outcome. During a mean follow-up time of 4 years (range: 1-7.5 years) two of the initially cured patients relapsed. They were recurred with a refresher course. Three had had a single or a few episodes of cystitis in the course of several years. Of the patients with pronounced reduction in their symptoms, three relapsed. A refresher course was attempted in two patients; one was successful. It can thus be concluded that BF is an effective way of treating this disturbance and the beneficial effect is to a wide degree maintained.
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Affiliation(s)
- D Kjølseth
- Urological Department K, Aarhus Municipal Hospital, Denmark
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44
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Abstract
Informing patients before the start of antineoplastic treatment is important due to the anxiety and uncertainty felt by the patients and the legal aspects of trials. 34 women were interviewed 3 months after receiving information. Results show that the information was well remembered, patients were glad to bring a relative, two consultations with time for deliberation were well-received and that patients viewed written information as an important reinforcement. Overall, information provided was positively evaluated. Detailed information allowed patients to understand and participate in treatment decisions, thereby reducing their pretherapy anxiety. These results support expansion of the structured information programme to include all patients about to begin long-term cancer therapy.
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Affiliation(s)
- A B Jensen
- Department of Oncology, Odense University Hospital, Denmark
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45
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Madsen B. [Who wants to have an undergraduate?]. Sygeplejersken 1992; 92:19. [PMID: 1412016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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46
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Pedersen EB, Jensen FT, Madsen B, Eiskjaer H, Nielsen JT, Rehling M. Angiotensin-converting enzyme inhibitor renography in the diagnosis of renovascular hypertension. Studies before and after angioplasty. Nephrol Dial Transplant 1992; 7:1178-84. [PMID: 1337156 DOI: 10.1093/ndt/7.12.1178] [Citation(s) in RCA: 9] [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] Open
Abstract
Renography with [99mTc] diethylenetriaminepenta-acetate (DTPA) was performed in 26 patients with renal artery stenosis (RAS), unilateral in 15 and bilateral in 11, and in 16 patients with essential hypertension with a normal renal angiogram. Nine of the patients with unilateral RAS were restudied after a successful percutaneous transluminal renal angioplasty (PTRA), i.e. complete removal of the stenosis and a normalization of the blood pressure without antihypertensive treatment. Single-kidney [99mTc]-DTPA clearance and parenchymal mean transit time (MTT) were determined at each examination. All patients were studied on two different days using the same procedure except that captopril 25 mg was given orally before renography at the second examination. In unilateral RAS captopril reduced single-kidney [99mTc]-DTPA clearance significantly on the affected side (-42.7%, median) but not on the unaffected side (-3.2%). In bilateral RAS single-kidney [99mTc]-DTPA clearance was reduced to the greatest extent on the most affected side (-43.0%) compared with the least affected side (-17.2%). In essential hypertension no significant changes were recorded on any side (-1.5% for both). After PTRA, single-kidney [99mTc]-DTPA clearance was not significantly changed by captopril either on the previously affected side (4.3%) or on the unaffected side. MTT was significantly prolonged after captopril on the affected side in unilateral RAS and on the most affected side in bilateral RAS, whereas no significant changes were found on the unaffected side in unilateral RAS, on the least affected side in bilateral RAS, or on any side in essential hypertension.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- E B Pedersen
- Department of Medicine and Nephrology C, Skejby Hospital, Aarhus, Denmark
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47
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Baekgaard N, Andresen JH, Madsen B. [Percutaneous embolization of vascular abnormalities]. Ugeskr Laeger 1990; 152:2857-8. [PMID: 2219519] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
In six male patients, percutaneous embolisation of symptom-producing vascular anomalies was performed with spirals or small particles. After a total of ten treatments, symptom-free states were obtained in half of the patients and definite improvement in the remainder. The results are so promising that this method of treatment will be continued.
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Affiliation(s)
- N Baekgaard
- Hjerte-lunge-karkirurgisk afdeling T, Skejby Sygehus, Aarhus
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48
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Pedersen EB, Jensen FT, Eiskjaer H, Hansen HH, Jensen JD, Jespersen B, Madsen B, Nielsen HK, Sørensen SS. Differentiation between renovascular and essential hypertension by means of changes in single kidney 99mTc-DTPA clearance induced by angiotensin-converting enzyme inhibition. Am J Hypertens 1989; 2:323-34. [PMID: 2655658 DOI: 10.1093/ajh/2.5.323] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Blood pressure (BP), plasma renin concentration (PRC), and 99mTc-labeled diethylenetriaminepenta acetate (DTPA) renography with determination of single kidney 99mTc-DTPA clearance and parenchymal mean transit time (MTT) were measured in exactly the same way on two consecutive days in 14 patients with renovascular hypertension (RVH), unilateral renal artery stenosis in nine and bilateral stenosis in five, and ten patients with essential hypertension (EH). The examination on day 1 served as a control for day 2 during which captopril (25 mg) was given orally one hour before measurements of PRC and DTPA clearance. Blood pressure was reduced by captopril in both groups, but the maximum decrease in systolic BP was slightly more pronounced (P less than .01) in RVH (22%, median) than EH (13%). Plasma renin concentration increased to a much greater extent (P less than .01) after captopril in RVH (366%) than in EH (46%), Single kidney 99mTc-DTPA clearance was significantly (P less than .01) reduced (-39.5%) and MTT considerably prolonged (170%) on the affected/most affected side in RVH, but both parameters were only slightly changed or unchanged on the unaffected/least affected side (-6.5%, -2% respectively) and were not significantly changed in any of the sides in EH. The degree of renal artery stenosis was significantly correlated to the increase in PRC (rho = -0.786, n = 14 patients, P less than .01), to the reduction in single kidney 99mTc-DTPA clearance (rho = 0.729, n = 19 kidneys, P less than .01) and to the prolongation in MTT (rho = -0.785, n = 16 kidneys, P less than .01). By analysis of the captopril-induced changes in 99mTc-DTPA clearance and MTT, it was possible to predict the existence of a moderate to several renal artery stenosis in arterial hypertension with a very high degree of probability, and the use of changes in 99mTc-DTPA clearance and MTT after angiotensin-converting enzyme (ACE) inhibition may become a valuable tool in differentiation between RVH and EH.
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Affiliation(s)
- E B Pedersen
- Department of Medicine C, Aarhus Kommunehospital, Denmark
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49
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Pedersen EB, Sørensen SS, Amdisen A, Danielsen H, Eiskjaer H, Hansen HH, Jensen FT, Jespersen B, Madsen B, Nielsen HK. Abnormal glomerular and tubular function during angiotensin converting enzyme inhibition in renovascular hypertension evaluated by the lithium clearance method. Eur J Clin Invest 1989; 19:135-41. [PMID: 2499471 DOI: 10.1111/j.1365-2362.1989.tb00207.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Glomerular filtration rate (GFR) and tubular function were measured by means of the lithium clearance technique in 14 patients with renovascular hypertension (RVH) and eight patients with essential hypertension (EH) before and after oral administration of captopril 25 mg. In RVH captopril reduced 51-Cr-EDTA clearance (67.3 (median) to 47.5 ml min-1, P less than 0.01), proximal absolute reabsorption of fluid (53.9 to 41.5 ml min-1, P less than 0.01) and distal absolute reabsorption of sodium (2195 to 1402 mumol min-1, P less than 0.01), whereas proximal fractional reabsorption increased slightly (77.5 to 80.2%, P less than 0.02). In EH, however, these parameters were practically unaffected by captopril. In both RVH and EH plasma concentrations of angiotensin II and aldosterone were reduced after captopril, but atrial natriuretic peptide in plasma and urinary excretion rate of prostaglandin E2 were unchanged. Blood pressure decreased after captopril in both groups, but the maximum fall in systolic BP was more pronounced in RVH (22%) than EH (13%). It is concluded that angiotensin converting enzyme inhibition markedly reduced absolute reabsorption in both the proximal and distal tubules in RVH, in contrast to EH, predominantly due to fall in the GFR, and that the slight increase in proximal fractional reabsorption may be attributed to a reduction in the hydrostatic pressure in the peritubular vessels.
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Affiliation(s)
- E B Pedersen
- Department of Medicine C, Aarhus Kommunehospital, Denmark
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50
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Abstract
Four modified atrial natriuretic factor (ANF) analogs were designed and synthesized by the solid-phase method. Using human ANF-(99-126) as the reference compound the receptor binding affinity and biological activity of these analogs were examined by radioreceptor assay and in vivo experiments. PLO68, a 21 amino peptide with structural modifications des-Ser103,104-[Mpr105,D-Ala107,114]APII-amide exhibited 2.5 and 2.2 fold more activity than human ANF-(99-126) in lowering blood pressure and causing natriuresis in urethane anesthetized rats. Receptor binding assays using rat lung membranes showed that PLO68 had a Kd of 200 +/- 12 pM compared to a Kd of 620 +/- 12 pM for human ANF-(99-126). Similar chemical modifications, except for substitution of glycine and alanine at the positions 115 and 118, and 120 by D-alanine resulted in three analogs PLO63 and PLO64, PLO67 respectively. PLO63, PLO64 and PLO69 had similar affinities and in vivo potency as human ANF-(99-126). These data suggest that the structural modifications made in PLO68 can cause an increase in the receptor binding ability and an enhancement of biological activities.
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Affiliation(s)
- D L Song
- Department of Medicine, Stanford University School of Medicine, CA
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