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Wind M, Dekker L, van den Akker-van Marle ME, Ballieux BEPB, Cobbaert CM, Rabelink TJ, van Lith JMM, Teng YKO, Sueters M. The addition of the sFlt-1/PlGF ratio to the protein/creatinine ratio in multiple pregnancy: Post-hoc analysis of the PREPARE cohort study. Pregnancy Hypertens 2024; 36:101111. [PMID: 38387424 DOI: 10.1016/j.preghy.2024.101111] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Revised: 01/14/2024] [Accepted: 02/11/2024] [Indexed: 02/24/2024]
Abstract
OBJECTIVE To assess the predictive accuracy of the sFlt-1/PlGF ratio cut-off 38 in addition to the standard-of-care spot urine protein/creatinine ratio (PCr) for multiple pregnancies in women with suspected pre-eclampsia. STUDY DESIGN Post-hoc analysis of a prospective cohort study. MAIN OUTCOME MEASURES Primary outcome was the occurrence of pre-eclampsia in one and four weeks after presentation with suspected pre-eclampsia. Test characteristics with 95% confidence intervals (CI) were calculated on pre-eclampsia development in one and four weeks. RESULTS Twenty-three multiple pregnancies with suspected pre-eclampsia between 20 and 37 weeks gestation were included for analysis. Women who eventually developed pre-eclampsia had a significantly higher PCr (34.0 vs. 16.5, p = 0.015), sFlt-1 (17033 vs. 5270 pg/ml, p = 0.047) and sFlt-1/PlGF ratio (99 vs. 25, p = 0.033) at baseline. Furthermore, PCr ≥ 30 and sFlt-1/PlGF ratio > 38 was respectively seen in 1/16 (6.3 %) and 3/16 (18.8 %) of the women who did not develop pre-eclampsia. For predicting pre-eclampsia within one week the sFlt-1/PlGF ratio sensitivity was 75.0 % [95 % CI 19.4-99.4] and the negative predictive value 93.8 % [73.0-98.8], while no pre-eclampsia developed when PCr was < 30. Consequently, the combination of these tests did not lead to an improvement in test characteristics, with non-significant differences in positive predictive value (50.0 % [29.5-70.5] versus 80.0 % [37.3-96.4]) compared to PCr alone for pre-eclampsia development in one week. CONCLUSIONS In addition to standard-of-care spot urine PCr measurements, this study has not been able to demonstrate that the sFlt-1/PlGF ratio cut-off 38 is of added value in the prediction of pre-eclampsia in multiple pregnancy. TRIAL REGISTRATION Netherlands Trial Register (NL8308).
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Affiliation(s)
- M Wind
- Department of Obstetrics, Leiden University Medical Centre, Leiden, the Netherlands.
| | - L Dekker
- Department of Obstetrics, Leiden University Medical Centre, Leiden, the Netherlands
| | | | - B E P B Ballieux
- Department of Clinical Chemistry, Leiden University Medical Centre, Leiden, the Netherlands
| | - C M Cobbaert
- Department of Clinical Chemistry, Leiden University Medical Centre, Leiden, the Netherlands
| | - T J Rabelink
- Department of Nephrology, Leiden University Medical Centre, Leiden, the Netherlands
| | - J M M van Lith
- Department of Obstetrics, Leiden University Medical Centre, Leiden, the Netherlands
| | - Y K O Teng
- Department of Nephrology, Leiden University Medical Centre, Leiden, the Netherlands
| | - M Sueters
- Department of Obstetrics, Leiden University Medical Centre, Leiden, the Netherlands
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Wind M, Gaasbeek AGA, Oosten LEM, Rabelink TJ, van Lith JMM, Sueters M, Teng YKO. Therapeutic plasma exchange in pregnancy: A literature review. Eur J Obstet Gynecol Reprod Biol 2021; 260:29-36. [PMID: 33713886 DOI: 10.1016/j.ejogrb.2021.02.027] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [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: 10/26/2020] [Revised: 01/24/2021] [Accepted: 02/25/2021] [Indexed: 01/13/2023]
Abstract
Therapeutic plasma exchange (TPE) is indicated as a treatment for a wide array of diseases, extensively addressed in the Guidelines of the American Society for Apheresis. In pregnancy, TPE is an uncommon event and application is largely based on extrapolation of efficacy and safety in a non-pregnant population. This review intends to describe the currently available experience of TPE in pregnancy to help clinicians recognise indications during pregnancy and to support current guideline recommendations with literature-based experiences. In order to identify the clinical indications for which TPE is applied in pregnant women, we performed a literature search including studies till November 2019, without a start date restriction. Data extraction included medical indication for TPE and safety of TPE in pregnant women. 279 studies were included for analysis. Nowadays, TPE is predominantly applied for thrombotic microangiopathies, lipid disorders and a variety of autoimmune diseases. The application of TPE during pregnancy remains largely empiric and relies on individual case reports in the absence of high-quality studies and definitive evidence-based guidelines. Safety profile of TPE during pregnancy appears to be comparable to application of TPE in non-pregnant patients. In conclusion, based on the limited evidence that we found in literature with a high risk of publication bias, TPE procedures can be used safely during pregnancy with the appropriate preparation and experience of a multidisciplinary team.
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Affiliation(s)
- M Wind
- Department of Obstetrics, Leiden University Medical Center, Leiden, the Netherlands.
| | - A G A Gaasbeek
- Department of Nephrology, Leiden University Medical Center, Leiden, the Netherlands
| | - L E M Oosten
- Department of Immunohematology and Blood Transfusion, Leiden University Medical Center, Leiden, the Netherlands
| | - T J Rabelink
- Department of Nephrology, Leiden University Medical Center, Leiden, the Netherlands
| | - J M M van Lith
- Department of Obstetrics, Leiden University Medical Center, Leiden, the Netherlands
| | - M Sueters
- Department of Obstetrics, Leiden University Medical Center, Leiden, the Netherlands
| | - Y K O Teng
- Department of Nephrology, Leiden University Medical Center, Leiden, the Netherlands
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Visser R, Wind M, de Graaf B, de Jongh FHC, van der Palen J, Thio BJ. Protective effect of a low single dose inhaled steroid against exercise induced bronchoconstriction. Pediatr Pulmonol 2015; 50:1178-83. [PMID: 25418114 DOI: 10.1002/ppul.23144] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/22/2014] [Revised: 10/02/2014] [Accepted: 10/19/2014] [Indexed: 11/08/2022]
Abstract
OBJECTIVE Daily use of inhaled corticosteroids (ICS) reduces exercise induced bronchoconstriction (EIB) in asthmatic children. A high single dose of ICS also provided acute protection against EIB. Objective of this study is to investigate whether a low single dose of ICS offers protection against EIB in asthmatic children. METHODS 31 Mild asthmatic children not currently treated with inhaled corticosteroids, 5-16 years, with EIB (fall in FEV0.5/1 ≥ 13%) were included in a prospective intervention study. They performed two ECT's within 2 weeks. Four hours before the second test children inhaled 200 μg beclomethasone-dipropionate (BDP) with a breath-actuated inhaler (BAI). RESULTS The median fall in FEV0.5/1 after 200 μg BDP was significantly reduced from 30.9% at baseline to 16.0% (P < 0.001). Twenty children (64.5%) showed a good response to 200 μg BDP (≥ 50% decrease in fall of FEV0.5/1), while 8 children showed a moderate response (25-50%), and three children showed no response at all (< 25%). CONCLUSION A low single dose ICS offers acute protection against EIB in the majority of asthmatic children not currently treated with inhaled corticosteroids.
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Affiliation(s)
- R Visser
- Department of Pediatrics, Medisch Spectrum Twente, KA Enschede, The Netherlands
| | - M Wind
- Department of Emergency, Röpcke-Zweers Hospital, Hardenberg, The Netherlands
| | - B de Graaf
- Department of Pediatrics, Medisch Spectrum Twente, KA Enschede, The Netherlands
| | - F H C de Jongh
- Department of Pulmonary Function, Medisch Spectrum Twente, Enschede, The Netherlands
| | - J van der Palen
- Medical School Twente, Medisch Spectrum Twente, Enschede, The Netherlands.,Department of Research Methodology, Measurement and Data Analysis, University of Twente, Enschede, The Netherlands
| | - B J Thio
- Department of Pediatrics, Medisch Spectrum Twente, KA Enschede, The Netherlands
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Rollet S, Colautti P, Grosswendt B, Herault J, Wind M, Gargioni E, Beck P, Latocha M, Moro D. Microdosimetric assessment of the radiation quality of a therapeutic proton beam: comparison between numerical simulation and experimental measurements. Radiat Prot Dosimetry 2011; 143:445-449. [PMID: 21159743 DOI: 10.1093/rpd/ncq483] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Using protons for the treatment of ocular melanoma (especially of posterior pole tumours), the radiation quality of the beam must be precisely assessed to preserve the vision and to minimise the damage to healthy tissue. The radiation quality of a therapeutic proton beam at the Centre Antoine Lacassagne in Nice (France) was measured using microdosimetric techniques, i.e. a miniaturised version of a tissue-equivalent proportional counter. Measurements were performed in a 1-µm site at different depths in a Lucite phantom. Experimental data showed a significant increase in the beam quality at the distal edge of the spread-out Bragg peak (SOBP). In this paper, the numerical simulation of the experimental setup is done with the FLUKA Monte Carlo radiation transport code. The calculated microdosimetric spectra are compared with the measured ones at different depths in tissue for a monoenergetic proton beam (E=62 MeV) and for a modulated SOBP. Numerically and experimentally predicted relative biological effectiveness values are in good agreement. The calculated frequency-averaged and dose-averaged lineal energy mean values are consistent with measured data.
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Affiliation(s)
- S Rollet
- Department Health and Environment, Austrian Institute of Technology, A-1220 Vienna, Austria.
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Rollet S, Beck P, Latocha M, Wind M, Zechner A, Taylor GC. TEPC Measurements and Monte Carlo Calculations for Evaluating Ambient Dose Equivalent Response in Mixed Radiation Fields around the Shielded Area of a Carbon Ion Accelerator. NUCL TECHNOL 2009. [DOI: 10.13182/nt09-a9110] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- S. Rollet
- Austrian Institute of Technology GmbH, A-2444 Seibersdorf, Austria
| | - P. Beck
- Austrian Institute of Technology GmbH, A-2444 Seibersdorf, Austria
| | - M. Latocha
- Austrian Institute of Technology GmbH, A-2444 Seibersdorf, Austria
| | - M. Wind
- Austrian Institute of Technology GmbH, A-2444 Seibersdorf, Austria
| | - A. Zechner
- Austrian Institute of Technology GmbH, A-2444 Seibersdorf, Austria
| | - G. C. Taylor
- National Physical Laboratory, Teddington TW11 0LW, United Kingdom
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Wind M, Bjelland M, Pérez-Rodrigo C, Te Velde SJ, Hildonen C, Bere E, Klepp KI, Brug J. Appreciation and implementation of a school-based intervention are associated with changes in fruit and vegetable intake in 10- to 13-year old schoolchildren--the Pro Children study. Health Educ Res 2008; 23:997-1007. [PMID: 18156147 DOI: 10.1093/her/cym078] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.9] [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
The purpose was to investigate the degree of implementation and appreciation of a comprehensive school-randomized fruit and vegetable intervention program and to what extent these factors were associated with changes in reported fruit and vegetable intake. The study was conducted among 10- to 13-year old children exposed to the intervention during the school year 2003-04 in Norway, Spain and the Netherlands. Children, parents and teachers completed questionnaires regarding (i) the implementation of the school curriculum, (ii) parental involvement, (iii) distribution of fruit and vegetables at school, (iv) children's appreciation of the project and (v) children's intake levels. Univariate analyses of covariance and multilevel multivariate regression analyses indicated that teacher-reported level of implementation of the school curriculum and schoolchildren's appreciation of the project were important determinants of changes in intake. The results point to the importance of optimal implementation of an attractive school curriculum.
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Affiliation(s)
- M Wind
- Department of Nutrition, Faculty of Medicine, University of Oslo, Blindern, 0316 Oslo, Norway.
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7
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Wind M, Schindler C. Simulation und Messung der Strahlintensitätsverteilung von Flachstrahldüsen. CHEM-ING-TECH 2008. [DOI: 10.1002/cite.200750661] [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: 11/06/2022]
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De Bourdeaudhuij I, te Velde S, Brug J, Due P, Wind M, Sandvik C, Maes L, Wolf A, Perez Rodrigo C, Yngve A, Thorsdottir I, Rasmussen M, Elmadfa I, Franchini B, Klepp KI. Personal, social and environmental predictors of daily fruit and vegetable intake in 11-year-old children in nine European countries. Eur J Clin Nutr 2007; 62:834-41. [PMID: 17522608 DOI: 10.1038/sj.ejcn.1602794] [Citation(s) in RCA: 75] [Impact Index Per Article: 4.4] [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: 11/09/2022]
Abstract
OBJECTIVE To investigate potential personal, social and physical environmental predictors of daily fruit intake and daily vegetable intake in 11-year-old boys and girls in nine European countries. SUBJECTS The total sample size was 13 305 (90.4% participation rate). RESULTS Overall, 43.2% of the children reported to eat fruit every day, 46.1% reported to eat vegetables every day. Daily fruit intake and daily vegetable intake was mainly associated with knowledge of the national recommendations, positive self-efficacy, positive liking and preference, parental modeling and demand and bringing fruit to school (odds ratio between 1.40 and 2.42, P<0.02). These factors were associated fairly consistently with daily fruit intake across all nine European countries, implying that a rather uniform intervention strategy to promote fruit can be used across Europe. For vegetables, the pattern was, however, less consistent. Differences between countries in cooking and preparing vegetables might be responsible for this larger diversity. CONCLUSIONS This study showed that especially a combination of personal and social factors is related to daily fruit and vegetable intake in schoolchildren. This shows that a comprehensive multilevel intervention strategy based upon a series of individual and social correlates will be most promising in the promotion of daily fruit and vegetable intake in children.
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Affiliation(s)
- I De Bourdeaudhuij
- Department of Movement and Sport Sciences, Ghent University, Watersportlaan 2, Ghent, Belgium.
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De Bourdeaudhuij I, Klepp KI, Due P, Rodrigo CP, de Almeida M, Wind M, Krølner R, Sandvik C, Brug J. Reliability and validity of a questionnaire to measure personal, social and environmental correlates of fruit and vegetable intake in 10–11-year-old children in five European countries. Public Health Nutr 2007; 8:189-200. [PMID: 15877912 DOI: 10.1079/phn2004673] [Citation(s) in RCA: 137] [Impact Index Per Article: 8.1] [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: 02/02/2023]
Abstract
AbstractObjectivesTo investigate the internal consistency of the scales and the test–retest reliability and predictive validity of behaviour theory-based constructs measuring personal, social and environmental correlates of fruit and vegetable intake in 10–11-year-old children.DesignTest–retest with one-week interval.SettingFive European countries: Norway, Spain, Denmark, Portugal, Belgium.SubjectsThree hundred and twenty-six children completed the questionnaire during class hours.ResultsFor the total sample across all countries, the test–retest reliability was good to very good (intra-class correlation coefficient (ICC) >0.60) for 12 out of the 15 fruit constructs and also for 12 out of the 15 vegetable constructs. Acceptable ICCs, ranging between 0.50 and 0.59, were found for the remaining constructs. Test–retest reliability was comparable across countries. Only in Portugal were some significantly lower ICCs found for some constructs (knowledge and barriers related to fruit, general self-efficacy related to fruit and vegetables) compared with the other countries. Cronbach'sαvalues were moderate to high (range 0.52 to 0.89) with the exception of the general self-efficacy scale, which had a value below 0.50 for both fruit (α= 0.42) and vegetables (α= 0.49). Spearman correlations with intake ranged between -0.16 and 0.54 for personal determinants and between 0.05 and 0.38 for environmental determinants. Compared with other studies, predictive validity can be considered moderate to good.ConclusionsThe questionnaire provides a reliable, valid and easy-to-administer tool for assessing personal, social and environmental factors of potential influence on fruit and vegetable intake in 10–11-year-olds.
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Affiliation(s)
- I De Bourdeaudhuij
- Department of Movement and Sport Sciences, Ghent University, Ghent, Belgium.
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Wind M, Graf R, Renker S, Spiess HW, Steffen W. Structure of amorphous poly-(ethylmethacrylate): A wide-angle x-ray scattering study. J Chem Phys 2005; 122:14906. [PMID: 15638699 DOI: 10.1063/1.1826031] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.1] [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
The local, temperature dependent structure of poly-(ethylmethacrylate) was studied with wide-angle x-ray scattering. The results were set into context to recent wide-angle neutron scattering results as well as to the results from a multitude of studies of the dynamics of this polymer. The temperature dependence of the wide angle x-ray results point to the development of local order which is backed by the neutron scattering results and which is connected to characteristic temperatures of the relaxation dynamic T(g) and T(c). The poly-(ethylmethacrylate) was studied in its predominantly syndiotactic as well as predominantly isotactic state displaying vastly different local structures as manifested in the x-ray results.
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Affiliation(s)
- M Wind
- Max Planck Institute for Polymer Research, Ackermannweg 10, D-55128 Mainz, Germany
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Pérez Rodrigo C, Aranceta J, Brug H, Wind M, Hildonen C, Klepp KI. [School-based education strategies to promote fruit and vegetable consumption: the Pro Children Project]. Arch Latinoam Nutr 2004; 54:14-9. [PMID: 15584467] [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: 05/01/2023]
Abstract
Available population data suggest that a high proportion of European children and young people eat less fruit and vegetables than desirable. School based health promotion strategies fostering healthy eating practices and regular physical activity has the potential for a major impact on health and wellbeing during childhood and later stages in life. The aim of Pro-Children project is to estimate the consumption of fruit and vegetables as well as its main determinants among 11 year old European children and their families. It also aims to develop and assess the effectiveness of a school-based intervention program to promote adequate consumption levels of fruit and vegetables among school children. In the first phase of the project, cross-sectional studies were carried out on random population samples in nine European countries. The study protocol included assessment of fruit and vegetable consumption and a questionnaire to ascertain key determinants. A school-based intervention program was designed based on the Attitude, Social Influence and Self-Efficacy model (ASE). Theoretically similar but culturally relevant interventions were designed to be tested in Norway, The Netherlands and Spain during two school years. Each intervention site follows-up 10 intervention schools implementing the program and 10 control schools. Intervention planning and design followed an intervention mapping procedure. Key behaviours and determinants to be addressed through the intervention were identified in order to develop a matrix of educational objectives. The provision of fruit and vegetables in the school is an outstanding element. Program activities include guided classroom activities, computer tailored messages for children, activities to be completed at home with the family and family targeted specific actions. Additionally, optional components for community reinforcement include mass media, school health services participation and implication of grocery stores in the project. Despite cultural and social diversity, common school-based strategies to increase fruit and vegetable consumption among children are feasible across Europe. Understanding specific situations will enhance implementation and gain support.
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Wind M, Saalwächter K, Wiesler UM, Müllen K, Spiess HW. Solid-State NMR Investigations of Molecular Dynamics in Polyphenylene Dendrimers: Evidence of Dense-Shell Packing. Macromolecules 2002. [DOI: 10.1021/ma021283d] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- M. Wind
- Max-Planck-Institute for Polymer Research, Postfach 3148, D-55021 Mainz, Germany, and Institut für Makromolekulare Chemie, Universität Freiburg, Stefan-Meier-Str. 31, D-79104 Freiburg, Germany
| | - K. Saalwächter
- Max-Planck-Institute for Polymer Research, Postfach 3148, D-55021 Mainz, Germany, and Institut für Makromolekulare Chemie, Universität Freiburg, Stefan-Meier-Str. 31, D-79104 Freiburg, Germany
| | - U.-M. Wiesler
- Max-Planck-Institute for Polymer Research, Postfach 3148, D-55021 Mainz, Germany, and Institut für Makromolekulare Chemie, Universität Freiburg, Stefan-Meier-Str. 31, D-79104 Freiburg, Germany
| | - K. Müllen
- Max-Planck-Institute for Polymer Research, Postfach 3148, D-55021 Mainz, Germany, and Institut für Makromolekulare Chemie, Universität Freiburg, Stefan-Meier-Str. 31, D-79104 Freiburg, Germany
| | - H. W. Spiess
- Max-Planck-Institute for Polymer Research, Postfach 3148, D-55021 Mainz, Germany, and Institut für Makromolekulare Chemie, Universität Freiburg, Stefan-Meier-Str. 31, D-79104 Freiburg, Germany
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Thormann W, Theurillat R, Wind M, Kuldvee R. Therapeutic drug monitoring of antiepileptics by capillary electrophoresis. Characterization of assays via analysis of quality control sera containing 14 analytes. J Chromatogr A 2001; 924:429-37. [PMID: 11521893 DOI: 10.1016/s0021-9673(01)00854-8] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.4] [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]
Abstract
Quality assurance is an important aspect in therapeutic drug monitoring (TDM). Capillary electrophoresis (CE) assays for determination of (i) ethosuximide via direct injection of serum or plasma, (ii) lamotrigine after protein precipitation by acetonitrile and analysis of an aliquot of the acidified supernatant, and (iii) carbamazepine and carbamazepine-10,11-epoxide after solute extraction followed by analysis of the reconstituted extract are characterized via analysis of a large number of commercial quality control sera containing up to 14 analytes (9 of them are anticonvulsants) in sub-therapeutic, therapeutic and toxicologic concentration levels. CE data obtained in single determinations are shown to compare well with the spike values and the mean of data determined in other laboratories using immunoassays and/or high-performance liquid chromatography, values that are reported by the external quality control scheme. Carbamazepine and ethosuximide drug levels are also shown to agree well with those determined in our departmental drug assay laboratory using automated immunoassays. The presented data reveal the effectiveness of assay assessment via analysis of quality control sera and confirm the robustness of the assays for TDM in a routine setting.
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Affiliation(s)
- W Thormann
- Department of Clinical Pharmacology, University of Berne, Switzerland.
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Wind M, Wesch H, Lehmann WD. Protein phosphorylation degree: determination by capillary liquid chromatography and inductively coupled plasma mass spectrometry. Anal Chem 2001; 73:3006-10. [PMID: 11467547 DOI: 10.1021/ac010066s] [Citation(s) in RCA: 89] [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: 11/29/2022]
Abstract
Capillary liquid chromatography (muLC) interfaced to inductively coupled plasma mass spectrometry (ICPMS) is introduced as a new micromethod to determine the phosphorylation degree in phosphoproteins and phosphopeptides containing cysteine and/or methionine residues. The stoichiometric phosphorus to sulfur (31P to 32S) ratio is experimentally determined by muLC-ICPMS and converted into the degree of phosphorylation using protein/ peptide sequence information. The method is applied to the phosphoproteins beta-casein, beta-casein, and recombinant protein kinase A catalytic subunit and to synthetic phosphopeptides. The accurate data obtained by muLC-ICPMS allow quantitative assessment of the compound-specific discrimination of the electrospray ionization process between nonphosphorylated and phosphorylated proteins and peptides.
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Affiliation(s)
- M Wind
- Central Spectroscopy and Department of Biophysics, German Cancer Research Center (DKFZ), Heidelberg
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15
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Wind M, Edler M, Jakubowski N, Linscheid M, Wesch H, Lehmann WD. Analysis of protein phosphorylation by capillary liquid chromatography coupled to element mass spectrometry with 31P detection and to electrospray mass spectrometry. Anal Chem 2001; 73:29-35. [PMID: 11195505 DOI: 10.1021/ac0009595] [Citation(s) in RCA: 124] [Impact Index Per Article: 5.4] [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
A method for phosphopeptide identification by capillary liquid chromatography (muLC) interfaced alternatively to element mass spectrometry (inductively coupled plasma mass spectrometry, ICPMS) and to electrospray ionization mass spectrometry (ESI-MS) is described. ICPMS is used for 31P detection and ESI-MS provides the corresponding molecular weight information. Alignment of the two separate muLC runs is performed using the baseline distortion at the elution front, which shows up in both muLC-ICPMS and muLC-ESI-MS. Both a quadrupole and a magnetic sector field mass analyzer were used in combination with ICP. The detection limit achieved for the muLC-ICP-HRMS runs is approximately 0.1 pmol of phosphopeptide injected. Without any further precautions, contamination by phosphate-containing compounds at this level was found to be uncritical. The method is demonstrated for the analysis of a complex mixture of synthetic phosphopeptides and a set of tryptic digests of three phosphoproteins. These include beta-casein, activated human MAP kinase ERK1, and protein kinase A catalytic subunit. The tryptic phosphopeptides of these proteins could all be detected and identified by our new strategy. Analysis of three fractions of protein kinase A catalytic subunit with different phosphorylation status gives direct access to the order in which the phosphorylation of the four phosphorylation sites occurs. The two most important aspects of using muLC-ICPMS with 31P detection for phosphopeptide identification are (i) that a high selectivity is achieved and (ii) that the signal intensity is independent of the chemical form of phosphorus and directly proportional to the molar amount of 31P in the muLC eluate. Thus, muLC-ICPMS with 31P detection is introduced as a new, robust, and specific method in phosphoproteomics.
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Affiliation(s)
- M Wind
- German Cancer Research Center,Heidelberg
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16
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Wind M, Hoffmann P, Wagner H, Thormann W. Chiral capillary electrophoresis as predictor for separation of drug enantiomers in continuous flow zone electrophoresis. J Chromatogr A 2000; 895:51-65. [PMID: 11105848 DOI: 10.1016/s0021-9673(00)00410-6] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [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: 10/17/2022]
Abstract
Separation of the enantiomers of chlorpheniramine and methadone in acidic buffers containing carboxymethyl-betacyclodextrin (CMCD) as chiral selector was investigated by capillary zone electrophoresis. For a range of pH and CMCD concentrations, the mobility difference and resolution of the enantiomers were determined. Then, conditions known to provide well resolved enantiomers and optimized chiral separation were applied to chiral continuous flow electrophoresis. In that approach, a thin film of fluid flowing between two parallel plates is employed as carrier for electrophoresis. The electrolytes and the sample are continuously admitted at one end of the electrophoresis chamber and are fractionated by an array of outlet tubes at the other. The number of pure enantiomeric fractions obtained by chiral continuous flow electrophoresis was found to be directly dependent on the enantiomeric mobility difference. For racemic chlorpheniramine separated in a betaine-acetic acid buffer at a total throughput of 5 mg/h, complete enantiomeric separation is shown to require a mobility difference of about 3 x 10(-9) m2/V s. Furthermore, compared to the previous investigations with hydroxypropyl-beta-cyclodextrin, CMCD was found to permit improved fractionation of methadone enantiomers. With a total racemic drug throughput of about 15 mg/h, continuous flow zone electrophoresis processing with CMCD as chiral selector is shown to have the potential of providing pure enantiomers on a mg/h scale. The results indicate that chiral capillary zone electrophoresis data can be employed as predictor for preparative scale chiral separations based upon continuous flow zone electrophoresis.
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Affiliation(s)
- M Wind
- lnstitut für Anorganische und Analytische Chemie und Radiochemie, Fachrichtung 11.4 der Universität des Saarlandes, Saarbrücken, Germany
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Abstract
OBJECTIVES To identify and assess dangers associated with placing children younger than 2 years to sleep in adult beds. This article focuses on overlying, wedging, and strangulation hazards and the relationship of these hazards to children's sleeping environments. DESIGN A retrospective review and analysis of data collected by the US Consumer Product Safety Commission on deaths of children younger than 2 years in standard adult beds, daybeds, and waterbeds. The review included incident data from January 1990 through December 1997. RESULTS The 8-year records showed a total of 515 deaths of children younger than 2 years who were placed to sleep on adult beds. Of these deaths, 121 were reported to be due to overlying of the child by a parent, other adult, or sibling sleeping in bed with the child and 394 were due to entrapment in the bed structure. Most of these deaths seem to have resulted from suffocation or strangulation caused by entrapment of the child's head in various structures of the bed. CONCLUSIONS Placing children younger than 2 years to sleep in adult beds exposes them to potentially fatal hazards that are generally not recognized by the parent or caregiver. These hazards include overlying by a parent, sibling, or other adult sharing the bed; entrapment or wedging of the child between the mattress and another object; head entrapment in bed railings; and suffocation on waterbeds. Parents and caregivers should be alerted to these avoidable hazards.
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Affiliation(s)
- S Nakamura
- US Consumer Product Safety Commission, Bethesda, MD 20814-4408, USA.
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Lennon JC, Wind M, Saunders L, Hock MB, Reines D. Mutations in RNA polymerase II and elongation factor SII severely reduce mRNA levels in Saccharomyces cerevisiae. Mol Cell Biol 1998; 18:5771-9. [PMID: 9742094 PMCID: PMC109163 DOI: 10.1128/mcb.18.10.5771] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.7] [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] [Received: 04/06/1998] [Accepted: 07/02/1998] [Indexed: 11/20/2022] Open
Abstract
Elongation factor SII interacts with RNA polymerase II and enables it to transcribe through arrest sites in vitro. The set of genes dependent upon SII function in vivo and the effects on RNA levels of mutations in different components of the elongation machinery are poorly understood. Using yeast lacking SII and bearing a conditional allele of RPB2, the gene encoding the second largest subunit of RNA polymerase II, we describe a genetic interaction between SII and RPB2. An SII gene disruption or the rpb2-10 mutation, which yields an arrest-prone enzyme in vitro, confers sensitivity to 6-azauracil (6AU), a drug that depresses cellular nucleoside triphosphates. Cells with both mutations had reduced levels of total poly(A)+ RNA and specific mRNAs and displayed a synergistic level of drug hypersensitivity. In cells in which the SII gene was inactivated, rpb2-10 became dominant, as if template-associated mutant RNA polymerase II hindered the ability of wild-type polymerase to transcribe. Interestingly, while 6AU depressed RNA levels in both wild-type and mutant cells, wild-type cells reestablished normal RNA levels, whereas double-mutant cells could not. This work shows the importance of an optimally functioning elongation machinery for in vivo RNA synthesis and identifies an initial set of candidate genes with which SII-dependent transcription can be studied.
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Affiliation(s)
- J C Lennon
- Graduate Program in Genetics and Molecular Biology and Department of Biochemistry, Emory University School of Medicine, Atlanta, Georgia 30322, USA
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19
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Abstract
RNA polymerases encounter specific DNA sites at which RNA chain elongation takes place in the absence of enzyme translocation in a process called discontinuous elongation. For RNA polymerase II, at least some of these sequences also provoke transcriptional arrest where renewed RNA polymerization requires elongation factor SII. Recent elongation models suggest the occupancy of a site within RNA polymerase that accommodates nascent RNA during discontinuous elongation. Here we have probed the extent of nascent RNA extruded from RNA polymerase II as it approaches, encounters, and departs an arrest site. Just upstream of an arrest site, 17-19 nucleotides of the RNA 3'-end are protected from exhaustive digestion by exogenous ribonuclease probes. As RNA is elongated to the arrest site, the enzyme does not translocate and the protected RNA becomes correspondingly larger, up to 27 nucleotides in length. After the enzyme passes the arrest site, the protected RNA is again the 18-nucleotide species typical of an elongation-competent complex. These findings identify an extended RNA product groove in arrested RNA polymerase II that is probably identical to that emptied during SII-activated RNA cleavage, a process required for the resumption of elongation. Unlike Escherichia coli RNA polymerase at a terminator, arrested RNA polymerase II does not release its RNA but can reestablish the normal elongation mode downstream of an arrest site. Discontinuous elongation probably represents a structural change that precedes, but may not be sufficient for, arrest by RNA polymerase II.
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Affiliation(s)
- W Gu
- Graduate Division of Biological and Biomedical Sciences, Emory University School of Medicine, Atlanta, GA 30322, USA
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Austin WL, Wind M, Brown KS. Differences in the toxicity and teratogenicity of cytochalasins D and E in various mouse strains. Teratology 1982; 25:11-8. [PMID: 7064108 DOI: 10.1002/tera.1420250103] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Adult toxicity, embryo lethality, and teratogenicity of cytochalasins D and E (CD and CE) were determined for A/J, C57BL/6JH, aeae, and OELN mouse strains. The adult LD50 for CD (1.9-2.6 mg/kg) and CE (3.1-3.3) were similar for the strains. Although adult LD50s were similar, the embryo lethality and teratogenicity of CD and CE vary from strain to strain when all were treated with intraperitoneal injections on days 7-9 of gestation. CD was more teratogenic than CE and frequently produced exencephaly while CE did not. CD was more teratogenic in OELN and aeae (ED50 +/- 0.7 mg/kg) than in A/J or C57BL/6J (ED50 greater than 1.2 mg/kg). OELN fetuses were more resistant to lethal effects of CD than the other strains which had fetal LD50s +/- 1.2 mg/kg maternal weight. The F1 fetuses of a cross of sensitive aeae and resistant C57BL/6J showed intermediate sensitivity to exencephaly. The results suggest a genetic contribution to the response and differences in action of CD and CE as teratogens.
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Abstract
Human fetal hemoglobin was more susceptible to methemoglobin formation in the presence of aminophenols than was adult hemoglobin. This was due to the intrinsic properties of the proteins rather than the presence of methemoglobin reductases.
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Abstract
The pH dependence of several functional properties of human fetal and adult hemoglobins have been studied to determine the relative stabilities of the high and low affinity (R and T) quaternary conformations of the two proteins under different conditions. Fetal aqumethemoglobin undergoes changes in sulfhydryl reactivity, absorption spectrum, and circular dichroism in the presence of insitol hexaphospahte which are consistent with a transition from the R to T quaternary state, but only at pH values below 6.8. In adult hemoglobin this transition can be induced pH values below 7.2. Even in the absence of phosphates, the ultraviolet (uv) circular dichroism spectrum of fetal aquomethemoglobin at low pH indicates the presence of some T conformation. The initial value for the second-order rate constant for combination of fetal deoxyhemoglobin with carbon monoxide is comparable to that for adult hemoglobin in the absence of organic phosphates and is not reduced by organic phosphates as much as that for the adult protein. The apparent first-order rate constant for dissociation of CO from fully liganded fetal hemoglobin, measured by replacement with NO, increases threefold in the absence of organic phosphates, and fourfold in the presence of organic phosphates, with decreasing pH; the midpoint of the pH dependent transition occurs around 6.8. A similar increase in the apparent first-order rate constant for O2 dissociation as measured by replacement with CO, can also be seen with decreasing pH. NO-hemoglobin F can be converted to the T state even when fully liganded simply by lowering the pH, as judged by uv circular dichroism, visible difference spectrum in the region of the alpha and beta bands, and a dramatic increase in the rate of NO dissociation, measured by replacement with CO in the presence of dithionite. These results are all consistent with a model for fetal hemoglobin in which the organic phosphate site may be functionally weakened by replacement of a residue involved in ionic interactions with the negatively charged phosphate groups, but in which the low affinity T conformation is intrinsically more stable than that of adllt hemoglobin. According to this model,the differences between fetal and adult hemoglobin can be accounted for primarily in terms of the relative stabilities of R and T conformations in each of the proteins with differences in the intrinsic properties of the individual conformations contributing effects of only secondary importance.
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Wind M, Berliner A, Stella AS, Guttman C. The binding of phenothiazines to oxyhemoglobin A and S. Res Commun Chem Pathol Pharmacol 1973; 5:759-66. [PMID: 4144819] [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: 01/09/2023]
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