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Tazifor Tchantcho M, Zimmermann E, Huisman JA, Dick M, Mester A, van Waasen S. Low-Pass Filters for a Temperature Drift Correction Method for Electromagnetic Induction Systems. Sensors (Basel) 2023; 23:7322. [PMID: 37687782 PMCID: PMC10489996 DOI: 10.3390/s23177322] [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] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2023] [Revised: 08/07/2023] [Accepted: 08/19/2023] [Indexed: 09/10/2023]
Abstract
Electromagnetic induction (EMI) systems are used for mapping the soil's electrical conductivity in near-surface applications. EMI measurements are commonly affected by time-varying external environmental factors, with temperature fluctuations being a big contributing factor. This makes it challenging to obtain stable and reliable data from EMI measurements. To mitigate these temperature drift effects, it is customary to perform a temperature drift calibration of the instrument in a temperature-controlled environment. This involves recording the apparent electrical conductivity (ECa) values at specific temperatures to obtain a look-up table that can subsequently be used for static ECa drift correction. However, static drift correction does not account for the delayed thermal variations of the system components, which affects the accuracy of drift correction. Here, a drift correction approach is presented that accounts for delayed thermal variations of EMI system components using two low-pass filters (LPF). Scenarios with uniform and non-uniform temperature distributions in the measurement device are both considered. The approach is developed using a total of 15 measurements with a custom-made EMI device in a wide range of temperature conditions ranging from 10 °C to 50 °C. The EMI device is equipped with eight temperature sensors spread across the device that simultaneously measure the internal ambient temperature during measurements. To parameterize the proposed correction approach, a global optimization algorithm called Shuffled Complex Evolution (SCE-UA) was used for efficient estimation of the calibration parameters. Using the presented drift model to perform corrections for each individual measurement resulted in a root mean square error (RMSE) of <1 mSm-1 for all 15 measurements. This shows that the drift model can properly describe the drift of the measurement device. Performing a drift correction simultaneously for all datasets resulted in a RMSE <1.2 mSm-1, which is considerably lower than the RMSE values of up to 4.5 mSm-1 obtained when using only a single LPF to perform drift corrections. This shows that the presented drift correction method based on two LPFs is more appropriate and effective for mitigating temperature drift effects.
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Affiliation(s)
- Martial Tazifor Tchantcho
- Central Institute of Engineering, Electronics and Analytics (ZEA-2), Forschungszentrum Juelich GmbH, 52428 Juelich, Germany
| | - Egon Zimmermann
- Central Institute of Engineering, Electronics and Analytics (ZEA-2), Forschungszentrum Juelich GmbH, 52428 Juelich, Germany
| | - Johan Alexander Huisman
- Institute of Bio- and Geosciences Agrosphere (IBG-3), Forschungszentrum Juelich GmbH, 52428 Juelich, Germany
| | - Markus Dick
- Central Institute of Engineering, Electronics and Analytics (ZEA-2), Forschungszentrum Juelich GmbH, 52428 Juelich, Germany
| | - Achim Mester
- Central Institute of Engineering, Electronics and Analytics (ZEA-2), Forschungszentrum Juelich GmbH, 52428 Juelich, Germany
| | - Stefan van Waasen
- Central Institute of Engineering, Electronics and Analytics (ZEA-2), Forschungszentrum Juelich GmbH, 52428 Juelich, Germany
- Faculty of Engineering, Communication Systems, University of Duisburg-Essen, 47057 Duisburg, Germany
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2
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McMichan L, Dick M, Skelton DA, Chastin SFM, Owen N, Dunstan DW, Fraser WD, Tang JCY, Greig CA, Agyapong-Badu S, Mavroeidi A. Sedentary behaviour and bone health in older adults: a systematic review. Osteoporos Int 2021; 32:1487-1497. [PMID: 33768342 DOI: 10.1007/s00198-021-05918-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Accepted: 03/09/2021] [Indexed: 10/21/2022]
Abstract
Older adults spend more than 8 h/day in sedentary behaviours. Detrimental effects of sedentary behaviour (SB) on health are established, yet little is known about SB and bone health (bone mineral density; BMD) in older adults. The purpose of this review is to examine associations of SB with BMD in older adults. Five electronic databases were searched: Web of Science (Core Collection); PubMed; EMBASE; Sports Medicine and Education and PsycInfo. Inclusion criteria were healthy older adults mean age ≥ 65 years; measured SB and measured BMD using dual-energy X-ray absorptiometry. Quality was assessed using National Institute of Health Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies. After excluding duplicates 17813 papers were assessed; 17757 were excluded on title/abstract, 49 at full text, resulting in two prospective and five cross-sectional observational studies reviewed. Four were rated 'good' and three were rated 'fair' using the quality assessment criteria. Findings varied across the studies and differed by gender. In women, four studies reported significant positive associations of SB with BMD at different sites, and two found significant negative associations. Five studies which examined both men and women, men reported negative or no associations of SB with femoral neck, pelvic, whole body, spine or leg BMD. Whilst these findings suggest differences between men and women in the associations of SB with BMD, they may be due to the varying anatomical sections examined for BMD, the different methods used to measure SB, the varied quality of the studies included and the limited number of published findings.
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Affiliation(s)
- L McMichan
- Department of Physical Activity for Health, School of Psychological Sciences and Health, University of Strathclyde, Glasgow, UK.
| | - M Dick
- Department of Physical Activity for Health, School of Psychological Sciences and Health, University of Strathclyde, Glasgow, UK
| | - D A Skelton
- Centre for Living, Department of Physiotherapy and Paramedicine, School of Health and Life Sciences, Glasgow Caledonian University, Glasgow, UK
| | - S F M Chastin
- Centre for Living, Department of Physiotherapy and Paramedicine, School of Health and Life Sciences, Glasgow Caledonian University, Glasgow, UK
- Department of Movement and Sports Science, Ghent University, Ghent, Belgium
| | - N Owen
- Baker Heart and Diabetes Institute, Melbourne, Australia
- Centre for Urban Transitions, Swinburne University, Melbourne, Australia
| | - D W Dunstan
- Baker Heart and Diabetes Institute, Melbourne, Australia
- Mary MacKillop Institute for Health Research, Australian Catholic University, Melbourne, Australia
| | - W D Fraser
- Norwich Medical School, University of East Anglia, Norwich, UK
| | - J C Y Tang
- Norwich Medical School, University of East Anglia, Norwich, UK
| | - C A Greig
- School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham, Birmingham, UK
- MRC-Versus Arthritis Centre for Musculoskeletal Ageing Research, University of Birmingham, Birmingham, UK
| | - S Agyapong-Badu
- School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham, Birmingham, UK
| | - A Mavroeidi
- Department of Physical Activity for Health, School of Psychological Sciences and Health, University of Strathclyde, Glasgow, UK
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Abstract
We previously engineered the β-subunit of tryptophan synthase (TrpB), which catalyzes the condensation of l-serine and indole to l-tryptophan, to synthesize a range of noncanonical amino acids from l-serine and indole derivatives or other nucleophiles. Here we employ directed evolution to engineer TrpB to accept 3-substituted oxindoles and form C-C bonds leading to new quaternary stereocenters. Initially, the variants that could use 3-substituted oxindoles preferentially formed N-C bonds on N1 of the substrate. Protecting N1 encouraged evolution toward C-alkylation, which persisted when protection was removed. Six generations of directed evolution resulted in TrpB Pfquat with a 400-fold improvement in activity for alkylation of 3-substituted oxindoles and the ability to selectively form a new, all-carbon quaternary stereocenter at the γ-position of the amino acid products. The enzyme can also alkylate and form all-carbon quaternary stereocenters on structurally similar lactones and ketones, where it exhibits excellent regioselectivity for the tertiary carbon. The configurations of the γ-stereocenters of two of the products were determined via microcrystal electron diffraction (MicroED), and we report the MicroED structure of a small molecule obtained using the Falcon III direct electron detector. Highly thermostable and expressed at >500 mg/L E. coli culture, TrpB Pfquat offers an efficient, sustainable, and selective platform for the construction of diverse noncanonical amino acids bearing all-carbon quaternary stereocenters.
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Affiliation(s)
- Markus Dick
- Division of Chemistry and Chemical Engineering 210-41, California Institute of Technology, 1200 East California Boulevard, Pasadena, California 91125, United States
| | - Nicholas S. Sarai
- Division of Chemistry and Chemical Engineering 210-41, California Institute of Technology, 1200 East California Boulevard, Pasadena, California 91125, United States
| | - Michael W. Martynowycz
- Howard Hughes Medical Institute, David Geffen School of Medicine, Departments of Biological Chemistry and Physiology, University of California, Los Angeles, Los Angeles, California 90095, United States
| | - Tamir Gonen
- Howard Hughes Medical Institute, David Geffen School of Medicine, Departments of Biological Chemistry and Physiology, University of California, Los Angeles, Los Angeles, California 90095, United States
| | - Frances H. Arnold
- Division of Chemistry and Chemical Engineering 210-41, California Institute of Technology, 1200 East California Boulevard, Pasadena, California 91125, United States
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Milić D, Dick M, Mulnaes D, Pfleger C, Kinnen A, Gohlke H, Groth G. Recognition motif and mechanism of ripening inhibitory peptides in plant hormone receptor ETR1. Sci Rep 2018; 8:3890. [PMID: 29497085 PMCID: PMC5832771 DOI: 10.1038/s41598-018-21952-3] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2017] [Accepted: 02/13/2018] [Indexed: 12/21/2022] Open
Abstract
Synthetic peptides derived from ethylene-insensitive protein 2 (EIN2), a central regulator of ethylene signalling, were recently shown to delay fruit ripening by interrupting protein-protein interactions in the ethylene signalling pathway. Here, we show that the inhibitory peptide NOP-1 binds to the GAF domain of ETR1 - the prototype of the plant ethylene receptor family. Site-directed mutagenesis and computational studies reveal the peptide interaction site and a plausible molecular mechanism for the ripening inhibition.
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Affiliation(s)
- Dalibor Milić
- Institute of Biochemical Plant Physiology and Bioeconomy Science Center (BioSC), Heinrich Heine University Düsseldorf, Düsseldorf, Germany
- Department of Structural and Computational Biology, Max F. Perutz Laboratories, University of Vienna, Vienna Biocenter, Vienna, Austria
| | - Markus Dick
- Institute of Pharmaceutical and Medicinal Chemistry and Bioeconomy Science Center (BioSC), Heinrich Heine University Düsseldorf, Düsseldorf, Germany
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California, USA
| | - Daniel Mulnaes
- Institute of Pharmaceutical and Medicinal Chemistry and Bioeconomy Science Center (BioSC), Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - Christopher Pfleger
- Institute of Pharmaceutical and Medicinal Chemistry and Bioeconomy Science Center (BioSC), Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - Anna Kinnen
- Institute of Biochemical Plant Physiology and Bioeconomy Science Center (BioSC), Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - Holger Gohlke
- Institute of Pharmaceutical and Medicinal Chemistry and Bioeconomy Science Center (BioSC), Heinrich Heine University Düsseldorf, Düsseldorf, Germany.
- John von Neumann Institute for Computing (NIC), Jülich Supercomputing Centre (JSC) & Institute for Complex Systems - Structural Biochemistry (ICS 6), Forschungszentrum Jülich GmbH, Jülich, Germany.
| | - Georg Groth
- Institute of Biochemical Plant Physiology and Bioeconomy Science Center (BioSC), Heinrich Heine University Düsseldorf, Düsseldorf, Germany.
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Dick M, Erlenkamp G, Nguyen GTT, Förster K, Groth G, Gohlke H. Pyrazolidine-3,5-dione-based inhibitors of phosphoenolpyruvate carboxylase as a new class of potential C 4 plant herbicides. FEBS Lett 2017; 591:3369-3377. [PMID: 28889573 DOI: 10.1002/1873-3468.12842] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2017] [Revised: 09/01/2017] [Accepted: 09/05/2017] [Indexed: 11/10/2022]
Abstract
Phosphoenolpyruvate carboxylase (PEPC) is a key enzyme in the C4 photosynthetic pathway of many of the world's worst weeds and a valuable target to develop C4 plant-selective herbicides. By virtual screening, analog synthesis, and in vitro validation, we identified pyrazolidine-3,5-diones as a new class of small molecules with inhibitory potential down to the submicromolar range against C4 PEPC and a selectivity factor of up to 16 over C3 PEPC. No other biological activity has yet been reported for the best compound, (3-bromophenyl)-4-(3-hydroxybenzylidene)-pyrazolidine-3,5-dione. A systematic variation in the substituents allowed the derivation of a qualitative structure-activity relationship. These findings make this compound class highly interesting for further investigations toward generating potent, C4 plant-selective herbicides with a low potential for unwanted effects.
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Affiliation(s)
- Markus Dick
- Institute of Pharmaceutical and Medicinal Chemistry and Bioeconomy Science Center (BioSC), Heinrich-Heine-Universität Düsseldorf, Germany
| | - German Erlenkamp
- Institute of Pharmaceutical and Medicinal Chemistry and Bioeconomy Science Center (BioSC), Heinrich-Heine-Universität Düsseldorf, Germany
| | - Giang T T Nguyen
- Institute of Biochemical Plant Physiology and Bioeconomy Science Center (BioSC), Heinrich-Heine-Universität Düsseldorf, Germany
| | - Kerstin Förster
- Institute of Biochemical Plant Physiology and Bioeconomy Science Center (BioSC), Heinrich-Heine-Universität Düsseldorf, Germany
| | - Georg Groth
- Institute of Biochemical Plant Physiology and Bioeconomy Science Center (BioSC), Heinrich-Heine-Universität Düsseldorf, Germany
| | - Holger Gohlke
- Institute of Pharmaceutical and Medicinal Chemistry and Bioeconomy Science Center (BioSC), Heinrich-Heine-Universität Düsseldorf, Germany
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6
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Bramski J, Dick M, Pietruszka J, Classen T. Probing the acetaldehyde-sensitivity of 2-deoxy-ribose-5-phosphate aldolase (DERA) leads to resistant variants. J Biotechnol 2017; 258:56-58. [DOI: 10.1016/j.jbiotec.2017.03.024] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2016] [Revised: 03/19/2017] [Accepted: 03/22/2017] [Indexed: 10/19/2022]
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Reinicke S, Rees HC, Espeel P, Vanparijs N, Bisterfeld C, Dick M, Rosencrantz RR, Brezesinski G, de Geest BG, Du Prez FE, Pietruszka J, Böker A. Immobilization of 2-Deoxy-d-ribose-5-phosphate Aldolase in Polymeric Thin Films via the Langmuir-Schaefer Technique. ACS Appl Mater Interfaces 2017; 9:8317-8326. [PMID: 28186396 DOI: 10.1021/acsami.6b13632] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
A synthetic protocol for the fabrication of ultrathin polymeric films containing the enzyme 2-deoxy-d-ribose-5-phosphate aldolase from Escherichia coli (DERAEC) is presented. Ultrathin enzymatically active films are useful for applications in which only small quantities of active material are needed and at the same time quick response and contact times without diffusion limitation are wanted. We show how DERA as an exemplary enzyme can be immobilized in a thin polymer layer at the air-water interface and transferred to a suitable support by the Langmuir-Schaefer technique under full conservation of enzymatic activity. The polymer in use is a poly(N-isopropylacrylamide-co-N-2-thiolactone acrylamide) (P(NIPAAm-co-TlaAm)) statistical copolymer in which the thiolactone units serve a multitude of purposes including hydrophobization of the polymer, covalent binding of the enzyme and the support and finally cross-linking of the polymer matrix. The application of this type of polymer keeps the whole approach simple as additional cocomponents such as cross-linkers are avoided.
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Affiliation(s)
- Stefan Reinicke
- Department of Functional Protein Systems and Biotechnology, Fraunhofer Institute of Applied Polymer Research (IAP) , Geiselbergstraße 69, 14476, Potsdam-Golm, Germany
| | - Huw C Rees
- Department of Chemistry, University of Chicago , Chicago, Illinois 60637, United States
| | - Pieter Espeel
- Department of Organic and Macromolecular Chemistry, Polymer Chemistry Research Group, Ghent University , Krijgslaan 281 S4-bis, 9000 Ghent, Belgium
| | - Nane Vanparijs
- Department of Pharmaceutics, Ghent University , Ottergemsesteenweg 460, 9000 Ghent, Belgium
| | - Carolin Bisterfeld
- Institut of Bioorganic Chemistry, Heinrich Heine University of Düsseldorf at Forschungszentrum Jülich , Stetternicher Forst, D-52426 Jülich, Germany
| | - Markus Dick
- Institut of Bioorganic Chemistry, Heinrich Heine University of Düsseldorf at Forschungszentrum Jülich , Stetternicher Forst, D-52426 Jülich, Germany
| | - Ruben R Rosencrantz
- Department of Functional Protein Systems and Biotechnology, Fraunhofer Institute of Applied Polymer Research (IAP) , Geiselbergstraße 69, 14476, Potsdam-Golm, Germany
- Polymer Materials and Polymer Technologies, University of Potsdam , 14476, Potsdam-Golm, Germany
| | - Gerald Brezesinski
- Max Planck Institute of Colloids and Interfaces , Science Park Potsdam-Golm, Am Mühlenberg 1, 14476 Potsdam, Germany
| | - Bruno G de Geest
- Department of Pharmaceutics, Ghent University , Ottergemsesteenweg 460, 9000 Ghent, Belgium
| | - Filip E Du Prez
- Department of Organic and Macromolecular Chemistry, Polymer Chemistry Research Group, Ghent University , Krijgslaan 281 S4-bis, 9000 Ghent, Belgium
| | - Jörg Pietruszka
- Institut of Bioorganic Chemistry, Heinrich Heine University of Düsseldorf at Forschungszentrum Jülich , Stetternicher Forst, D-52426 Jülich, Germany
- IBG-1: Biotechnology, Forschungszentrum Jülich GmbH , 52425 Jülich, Germany
| | - Alexander Böker
- Department of Functional Protein Systems and Biotechnology, Fraunhofer Institute of Applied Polymer Research (IAP) , Geiselbergstraße 69, 14476, Potsdam-Golm, Germany
- Polymer Materials and Polymer Technologies, University of Potsdam , 14476, Potsdam-Golm, Germany
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Pernsteiner H, Dick M, Mitter C, Feldbauer Durstmüller B. The impact of finance and governance on the internationalisation modes of family firms. EJIM 2017. [DOI: 10.1504/ejim.2017.10001684] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Brauer HU, Walther W, Dick M. [Professionalization of Legal Dental Experts in Germany: Results of Studies on Structured Focus Groups]. Gesundheitswesen 2016; 80:342-345. [PMID: 27780279 DOI: 10.1055/s-0042-116588] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
BACKGROUND Legal expert opinions are a crucial instrument of professional self-control in medicine. To give impulses for further development, focus groups were initiated to reflect upon the perspective of legal dental experts. METHODS 5 focus group discussions on the topic "Professionalization of legal dental experts" were conducted. A total of 32 experienced legal dental experts participated in the discussions. The results were evaluated by qualitative content analysis. RESULTS A catalogue of 68 ideas was generated for improvement and divided into 15 categories. Among these were periodic quality circles, interprofessional exchange, supervision of novices and periodic feedback for legal dental experts and dentists. CONCLUSION Self-reflection can be included as an instrument for quality improvement of legal dental expert opinions.
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Affiliation(s)
- H U Brauer
- Dorow Clinic Lörrach, Abteilung für Zahnmedizin/Kieferchirurgie, Lörrach
| | - W Walther
- Akademie für Zahnärztliche Fortbildung, Continuing Professional Development, Karlsruhe
| | - M Dick
- Institut für Berufs- und Betriebspädagogik, Otto-von-Guericke-Universität Magdeburg, Magdeburg
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11
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Affiliation(s)
- M. Dick
- University College Hospital, London
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12
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Dick M, Hartmann R, Weiergräber OH, Bisterfeld C, Classen T, Schwarten M, Neudecker P, Willbold D, Pietruszka J. Mechanism-based inhibition of an aldolase at high concentrations of its natural substrate acetaldehyde: structural insights and protective strategies. Chem Sci 2016; 7:4492-4502. [PMID: 30155096 PMCID: PMC6016325 DOI: 10.1039/c5sc04574f] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2015] [Accepted: 03/29/2016] [Indexed: 11/21/2022] Open
Abstract
2-Deoxy-d-ribose-5-phosphate aldolase (DERA) is used in organic synthesis for the enantioselective reaction between acetaldehyde and a broad range of other aldehydes as acceptor molecules. Nevertheless, its application is hampered by a poor tolerance towards high concentrations of acetaldehyde, its natural substrate. While numerous studies have been performed searching for new, more acetaldehyde-resistant DERAs, the mechanism underlying this deactivation process has remained elusive. By using NMR spectroscopy on both the protein and the small-molecule scale, we could show that a reaction product binds to the inner part of the enzyme, and that this effect can be partly reversed via heating. The crystal structure of DERA before and after acetaldehyde incubation was determined at high resolution, revealing a covalently bound reaction product bridging the catalytically active lysine (K167) to a nearby cysteine (C47) in the deactivated enzyme. A reaction mechanism is proposed where crotonaldehyde as the aldol product of two acetaldehyde molecules after water elimination forms a Schiff base with the lysine side chain, followed by Michael addition of the cysteine thiol group to the Cβ atom of the inhibitor. In support of this mechanism, direct incubation of DERA with crotonaldehyde results in a more than 100-fold stronger inhibition, compared to acetaldehyde, whereas mutation of C47 gives rise to a fully acetaldehyde-resistant DERA. Thus this variant appears perfectly suited for synthetic applications. A similar diagnostic and preventive strategy should be applicable to other biocatalysts suffering from mechanism-based inhibition by a reactive substrate, a condition that may be more common than currently appreciated in biotechnology.
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Affiliation(s)
- Markus Dick
- Institute of Bioorganic Chemistry , Heinrich-Heine-Universität Düsseldorf im Forschungszentrum Jülich , 52426 Jülich , Germany .
| | - Rudolf Hartmann
- Institute of Complex Systems , ICS-6: Structural Biochemistry , Forschungszentrum Jülich GmbH , 52425 Jülich , Germany
| | - Oliver H Weiergräber
- Institute of Complex Systems , ICS-6: Structural Biochemistry , Forschungszentrum Jülich GmbH , 52425 Jülich , Germany
| | - Carolin Bisterfeld
- Institute of Bioorganic Chemistry , Heinrich-Heine-Universität Düsseldorf im Forschungszentrum Jülich , 52426 Jülich , Germany .
| | - Thomas Classen
- Institute of Bio- and Geosciences , IBG-1: Biotechnology , Forschungszentrum Jülich GmbH , 52425 Jülich , Germany
| | - Melanie Schwarten
- Institute of Complex Systems , ICS-6: Structural Biochemistry , Forschungszentrum Jülich GmbH , 52425 Jülich , Germany
| | - Philipp Neudecker
- Institute of Complex Systems , ICS-6: Structural Biochemistry , Forschungszentrum Jülich GmbH , 52425 Jülich , Germany
- Institut für Physikalische Biologie , Heinrich-Heine-Universität Düsseldorf , 40225 Düsseldorf , Germany
| | - Dieter Willbold
- Institute of Complex Systems , ICS-6: Structural Biochemistry , Forschungszentrum Jülich GmbH , 52425 Jülich , Germany
- Institut für Physikalische Biologie , Heinrich-Heine-Universität Düsseldorf , 40225 Düsseldorf , Germany
| | - Jörg Pietruszka
- Institute of Bioorganic Chemistry , Heinrich-Heine-Universität Düsseldorf im Forschungszentrum Jülich , 52426 Jülich , Germany .
- Institute of Bio- and Geosciences , IBG-1: Biotechnology , Forschungszentrum Jülich GmbH , 52425 Jülich , Germany
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Pietruszka J, Bisterfeld C, Küberl I, Dick M. A Fluorogenic Screening for Enantio- and Diastereoselectivity of 2-Deoxy-d-ribose-5-phosphate Aldolases. Synlett 2015. [DOI: 10.1055/s-0035-1560723] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Affiliation(s)
- Jörg Pietruszka
- Institute of Bioorganic Chemistry, Heinrich-Heine-University at Forschungszentrum Jülich, and Bioeconomy Science Center (BioSC)
| | - Carolin Bisterfeld
- Institute of Bioorganic Chemistry, Heinrich-Heine-University at Forschungszentrum Jülich, and Bioeconomy Science Center (BioSC)
| | - Irene Küberl
- Institute of Bioorganic Chemistry, Heinrich-Heine-University at Forschungszentrum Jülich, and Bioeconomy Science Center (BioSC)
| | - Markus Dick
- Institute of Bioorganic Chemistry, Heinrich-Heine-University at Forschungszentrum Jülich, and Bioeconomy Science Center (BioSC)
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Chapman J, Algera D, Dick M, Hawkins E, Lawrence M, Lennox R, Rous A, Souliere C, Stemberger H, Struthers D, Vu M, Ward T, Zolderdo A, Cooke S. Being relevant: Practical guidance for early career researchers interested in solving conservation problems. Glob Ecol Conserv 2015. [DOI: 10.1016/j.gecco.2015.07.013] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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Walle J, Claus S, Snauwaert E, Rudder J, Raes A, Dick M, Prytula A, Biesen W, Eloot S. Prometheus® liver therapy in children with acute liver failure. Crit Care 2015. [PMCID: PMC4470693 DOI: 10.1186/cc14461] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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Wedderburn CJ, Rees D, Height S, Dick M, Rafferty GF, Lunt A, Greenough A. Airways obstruction and pulmonary capillary blood volume in children with sickle cell disease. Pediatr Pulmonol 2014; 49:724. [PMID: 24347555 DOI: 10.1002/ppul.22952] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/08/2013] [Accepted: 10/22/2013] [Indexed: 11/11/2022]
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Reiß W, Dick M, Walther W, Brauer H. Wie erleben Zahnärzte eine gerichtliche Auseinandersetzung mit Patienten? Eine qualitative Untersuchung. Gesundheitswesen 2013; 75:296-300. [DOI: 10.1055/s-0033-1334934] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Affiliation(s)
- W. Reiß
- Akademie für Zahnärztliche Fortbildung Karlsruhe
| | - M. Dick
- Institut für Berufs- und Betriebspädagogik, Otto-von-Guericke-Universität Magdeburg
| | - W. Walther
- Akademie für Zahnärztliche Fortbildung Karlsruhe
| | - H. Brauer
- Akademie für Zahnärztliche Fortbildung Karlsruhe
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Dick M, Lee A, Bright M, Turner K, Edwards R, Dawson J, Miller J. Evaluation of implementation of a healthy food and drink supply strategy throughout the whole school environment in Queensland state schools, Australia. Eur J Clin Nutr 2012; 66:1124-9. [DOI: 10.1038/ejcn.2012.108] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Brauer HU, Riesen C, Walther W, Dick M. [Attitudes of dental legal expert witnesses on their present status in Germany and approaches to the development of the profession]. Gesundheitswesen 2011; 74:42-4. [PMID: 21755493 DOI: 10.1055/s-0031-1280755] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
BACKGROUND Dental litigation has a key role for the autonomy of the dental profession. We conducted a study among legal dental expert witnesses in order to reflect the present situation and reveal the potential for professional development. METHODS A questionnaire was distributed among 161 participants of the Karlsruhe training for legal dental experts between 2004 and 2009. They were asked to describe and to reflect on the present situation of dental litigation in Germany. RESULTS 83 questionnaires were returned (51.6%). The main reason to become a legal dental expert was to "support the profession". 68 participants (85.0%) think that civil action resulting from dental treatment will become more frequent. The quality of dental expert opinions is considered to be in need of improvement. Strategies to optimise dental expert opinions and to deal with the potential growing number of claims are developed. CONCLUSION Basic and advanced training for dental expert witnesses assures the quality of dental expert opinions and also provides a chance for the further development of the dental profession.
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Affiliation(s)
- H U Brauer
- Akademie für Zahnärztliche Fortbildung Karlsruhe
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20
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Abstract
The influence of osmotic conditions on the gradient of capillary permeability disclosed by the distribution into mammalian muscle of vital dyes has been tested experimentally. The percentage of circulating blood proteins was increased in rabbits by the injection of compatible plasma, or of compatible serum concentrate obtained by means of a new method of ultrafiltration which has proved both rapid and effective. It was found that when this had been done and the circulatory conditions had stabilized themselves, the gradient of capillary permeability still existed, though its effective extent was less than under normal circumstances. When the percentage of circulating blood proteins was reduced, on the other hand, by repeated bleedings with return of the cells, either as such or suspended in the protein-free fluid obtained by dialysis of serum, the extent of the gradient of capillary permeability was broadened and dye passed out into the tissue more readily than usual from the capillary as a whole. In contrast to these findings injection of a very hypertonic dextrose solution during the period when dye was escaping had no perceptible effect on the gradient of capillary permeability. The observed phenomena cannot be explained by a flow of dye-stained fluid into or out of the blood vessels. The gradient of capillary permeability exists independently of osmotic conditions, though its extent can be markedly influenced by altering the amount of circulating blood proteins. A considerable proportion of the dye used to study the gradient is adsorbed upon these proteins, as subsidiary experiments have shown. This happening provides a sufficient cause for the differences observed in the extent of the gradient when the percentage of proteins is increased or diminished. The evidence like that of previous papers indicates that the cause for the gradient is to be found in a structural differentiation along the capillary, such that the barrier offered by its wall progressively diminishes on the way to the venule. Most current estimates of the effective osmotic pressure of the blood proteins fail to take into account the existence of local differences in permeability along the capillary.
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Affiliation(s)
- F Smith
- Laboratories of The Rockefeller Institute for Medical Research
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21
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Eckert K, Schrader G, Wilkinson D, Askew D, Dick M, Wade T, Marwick T, Scuffham P, Jackson C, Schluter P, Stewart S. Detection and Management of Depression in Patients with Chronic Heart Disease: The Take Heart in Primary Care Cluster Randomised Controlled Trial. Heart Lung Circ 2010. [DOI: 10.1016/j.hlc.2010.06.584] [Citation(s) in RCA: 2] [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: 11/17/2022]
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22
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Dick M, Bettencourt E, Abreu R. P1000 Serous borderline tumor of the fallopian tube presented as adnexal mass: case report. Int J Gynaecol Obstet 2009. [DOI: 10.1016/s0020-7292(09)62486-3] [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: 11/15/2022]
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23
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Robra B, Dick M, Marotzki W, Walther W. Worüber berichten Zahnärzte, wenn sie nach Dilemma-Situationen in der Praxis gefragt werden? Ein Beitrag zur qualitativen Versorgungsforschung. Gesundheitswesen 2009. [DOI: 10.1055/s-0029-1239078] [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: 10/20/2022]
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24
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Bollert G, Dick M, Geuter G, Klemme B, Schmidt W, Walkenhorst U. Bezugswissenschaften der Physiotherapie: Pädagogik und Psychologie. physioscience 2009. [DOI: 10.1055/s-0028-1109656] [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: 10/20/2022]
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25
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Nennstiel M, Blum M, Dick M, Kunert KS. Dynamische akkommodative Aberrometrie mithilfe einer binokularen Stimulation. Klin Monbl Augenheilkd 2008. [DOI: 10.1055/s-2008-1058041] [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: 10/19/2022]
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26
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Blum M, Kunert KS, Riehemann S, Nolte S, Dick M. Presbyopietherapie mit Femtosekundenlaser. Klin Monbl Augenheilkd 2008. [DOI: 10.1055/s-2008-1057985] [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: 10/21/2022]
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Nennstiel M, Kunert K, Dick M, Vogelsang H, Blum M. Dynamische Aberrometrie der Akkommodation mit binokularer Stimulation. Klin Monbl Augenheilkd 2007. [DOI: 10.1055/s-2007-984626] [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: 10/21/2022]
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Abstract
Presbyopia is by far the most common refractive error worldwide, with no permanent therapeutic option available. All efforts to restore accommodation by the use of surgery have not led to a generally accepted therapy. However, there is evidence from an animal model that the use of a femtosecond (fs) laser might influence the modulus of elasticity in the lens. Fs-laser impulses can create intralenticular disruption in animal eyes as well as human cadaver lenses and improve elasticity. The concept of treating presbyopia with fs-laser requires a new, complex theory combining the optical and the mechanical aspects of accommodation in the eye. Diagnostic tools for measuring optical change in power and geometrical modification as the eye views from far to near are needed to obtain objective clinical data. A non-invasive treatment of presbyopia to restore accommodation might be possible in the future.
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Affiliation(s)
- M Blum
- Klinik für Augenheilkunde, Helios-Klinikum Erfurt, Nordhäusser-Strasse 74, 99089 Erfurt.
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Henderson A, Dick M. Response to Verri et al. ( Journal of Intellectual Disability Research 48, 679-686): is there room for hope when considering the problem of late diagnosis in intellectual disability? J Intellect Disabil Res 2005; 49:690-1. [PMID: 16108986 DOI: 10.1111/j.1365-2788.2005.00712.x] [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: 05/04/2023]
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Aiyagari R, Saarel EV, Etheridge SP, Bradley DJ, Dick M, Fischbach PS. Radiofrequency ablation for supraventricular tachycardia in children < or =15 kg is safe and effective. Pediatr Cardiol 2005; 26:622-6. [PMID: 16132307 DOI: 10.1007/s00246-004-0849-4] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.1] [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: 10/25/2022]
Abstract
Risks associated with radiofrequency ablation (RFA) have been reported to be increased in children < or =15 kg. We sought to compare the safety and efficacy of RFA in children <15 kg with those between 15.1 and 20 kg. Clinical, electrophysiologic, and RFA data for all patients < or =20 kg who underwent RFA for supraventricular tachycardia between January 1994 and January 2003 were reviewed. Patients were divided into those < or =15 kg (group 1, n = 25) and those between 15.1 and 20 kg (group 2, n = 44). The two groups differed significantly in age and weight by design (group 1: mean weight, 11.9 +/- 3.0 kg; age, 2.8 +/- 1.9 years; group 2: weight, 18.0 +/- 1.5 kg; age, 5.1 +/- 1.1 years). There were no significant differences in other baseline characteristics except for incidence of structural heart disease (28% group 1 vs 7% group 2, p < 0.01). No significant differences in mechanism of tachycardia, arrhythmia cycle length, number of total and brief RFA applications, total RFA time, average and maximum RFA temperatures, total procedure duration, short-term success rate (96% group 1 vs 86% group 2, p = 0.17), long-term success rate (91% group 1 vs 89% group 2, p = 0.76), or major complications (8.0% group 1 vs 2.3% group 2, p = 0.39) were found. There were no procedure-related deaths in either group. These data suggest that, in two large volume electrophysiology centers, the procedural risks and outcomes of RFA are similar between patients weighing less than 15 kg and those between 15.1 and 20 kg.
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Affiliation(s)
- R Aiyagari
- C.S. Mott Children's Hospital, University of Michigan Medical Center, 1500 E. Medical Center Drive, L1242 Women's 0204, Ann Arbor, MI 48109-0204, USA
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33
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Sylvester KP, Patey RA, Milligan P, Dick M, Rafferty GF, Rees D, Thein SL, Greenough A. Pulmonary function abnormalities in children with sickle cell disease. Thorax 2004; 59:67-70. [PMID: 14694252 PMCID: PMC1758855] [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: 04/27/2023]
Abstract
BACKGROUND Adults with sickle cell disease (SCD) have restrictive lung function abnormalities which are thought to result from repeated lung damage caused by episodes of pulmonary vaso-occlusion; such episodes start in childhood. A study was therefore undertaken to determine whether children with SCD have restrictive lung function abnormalities and whether the severity of such abnormalities increases with age. METHODS Sixty four children with SCD aged 5-16 years and 64 ethnic matched controls were recruited. Weight and sitting and standing height were measured, and lung function was assessed by measurement of lung volumes and forced expiratory volume in 1 second (FEV1), forced vital capacity (FVC), and peak expiratory flow (PEF) before and after bronchodilator. RESULTS Compared with the control subjects, the children with SCD had lower mean (SD) sitting height (69 (6.3) cm v 73 (7.7) cm; p=0.004), sitting:standing height ratio (0.50 (0.02) v 0.51 (0.01); p<0.0001), weight (33 (10.9) kg v 41 (14.9) kg; p=0.001), functional residual capacity measured by a helium gas dilution technique (1.2 (0.3) l v 1.3 (0.4) l; p=0.04), FEV1 (1.5 (0.5) l v 1.9 (0.7) l; p=0.0008), FVC (1.7 (0.6) l v 2.1 (0.8) l; p=0.001), and PEF (3.9 (1.3) l/s v 4.8 (1.5) l/s; p=0.0004). The effect of age on lung function differed significantly between the children with SCD and the controls for total lung capacity and vital capacity measured by plethysmography and functional residual capacity measured by helium gas dilution. CONCLUSION Lung function differs significantly in children with SCD compared with ethnic matched controls of a similar age. Our results suggest that restrictive abnormalities may become more prominent with increasing age.
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Affiliation(s)
- K P Sylvester
- Department of Child Health, Guy's, King's & St Thomas' School of Medicine, King's College, London, UK
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34
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Horenstein MS, Saarel E, Dick M, Karpawich PP. Reversible symptomatic dilated cardiomyopathy in older children and young adolescents due to primary non-sinus supraventricular tachyarrhythmias. Pediatr Cardiol 2003; 24:274-9. [PMID: 12545317 DOI: 10.1007/s00246-002-0274-5] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Dilated cardiomyopathy (DCM) due to a primary supraventricular tachycardia not originating from the sinus node is not frequently seen in older children or adolescents. However, it is important to recognize this entity as a reversible cause of DCM to avoid costly and inappropriate treatments for these patients. We describe 7 patients who presented with DCM. Five were misdiagnosed as having "sinus" tachycardia secondary to an idiopathic DCM, and 2 were correctly diagnosed as having DCM secondary to an atrial tachycardia. All underwent electrophysiologic treatment of the tachycardia with remission of the DCM.
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Affiliation(s)
- M S Horenstein
- Division of Cardiology, Department of Pediatrics, Children's Hospital of Michigan, Wayne State University, Detroit, MI, USA
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35
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Abstract
OBJECTIVE To assess the use of a 'near patient' test for rapid antigen detection to obtain the more timely acquisition of data for the surveillance of influenza epidemics. METHODS To the classical cell culture system used for the surveillance of influenza, a 'near patient' test was added. The cell culture method was applied for the detection of influenza virus in specimens sent to our laboratory. In contrast, the 'near patient' test was used directly by practitioners in their practices to screen patients for the presence of influenza virus antigen. RESULTS The results for two seasons are presented. The 'near patient' test was able to detect a developing influenza epidemic with the same reliability as clinical consultation reports for influenza-like illness or the conventional culture method. However, the results obtained were available 9 days earlier on average, compared with cell culture. Because of this, results concerning the epidemics could be announced via the internet more rapidly. Although the 'near patient' test demonstrated a lower sensitivity than detection by conventional cell culture, the sensitivity was still sufficiently high to reveal the characteristics of the epidemics in the community. CONCLUSIONS Rapid influenza testing is a reliable tool for influenza surveillance and, compared with traditional methods (virus detection on cell culture and monitoring of influenza-like illness), provides faster results. Although the 'near patient' test has limited sensitivity compared with cell culture, results were consistent over two seasons, and suggest that rapid testing should be part of a surveillance program.
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Affiliation(s)
- W Wunderli
- Central Laboratory of Virology, University Hospital of Geneva, Geneva, Switzerland.
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36
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Patey RA, Sylvester KP, Rafferty GF, Dick M, Greenough A. The importance of using ethnically appropriate reference ranges for growth assessment in sickle cell disease. Arch Dis Child 2002; 87:352-3. [PMID: 12244019 PMCID: PMC1763031 DOI: 10.1136/adc.87.4.352] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [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: 11/03/2022]
Abstract
Height and weight were measured and body mass index (BMI) calculated in 56 sickle cell disease (SCD), 57 Caucasian (CC), and 63 African/Caribbean (AC) 3-9 year old children. The SCD children were taller, but had similar weight and BMI to the CC controls. The SCD group had lower weight and BMI than the AC controls. The AC controls were of greater height, weight, and BMI than CC controls. These data highlight the importance of using ethnically appropriate reference ranges.
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Affiliation(s)
- R A Patey
- Paediatric Respiratory Laboratory, Department of Child Health, Guy's, King's and St Thomas' School of Medicine, King's College Hospital, London, UK
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37
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Abstract
AIMS To assess sickle cell pain and coping in children and to examine the relation between these factors and the utilisation of health services. METHODS Cross sectional study involving 67 children with sickle cell disease attending three London hospitals. Interviews and questionnaires involved measures of pain, health service utilisation, and coping responses (measured with the Coping Strategies Questionnaire (CSQ), revised for children with sickle cell disease). Medical data on complications, haemoglobin (Hb) levels, and foetal haemoglobin (HbF) percentage were also collected. RESULTS Pain accounted for about 24% of hospital service use, independent of age, sex, number of with sickle cell disease complications, and Hb levels. However, 42% of patients had not utilised hospital services in the past 12 months. Three higher order factors emerged from analysis of the CSQ (active coping, affective coping, passive adherence coping). Pain severity was predicted by passive adherence coping, while utilisation of hospital services was predicted by active coping. CONCLUSIONS Sickle cell disease in children involves severe recurrent pain leading to hospitalisation in some cases. Psychological coping patterns are relevant to both pain experience, and the use of acute hospital services. It is likely that children would benefit from community based interventions that incorporate both medical and psychological assessments.
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Affiliation(s)
- K A Anie
- Brent Sickle Cell and Thalassaemia Centre, Department of Haematology, Central Middlesex Hospital, London, UK.
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Kusiak A, Law IH, Dick M. The G-algorithm for extraction of robust decision rules--children's postoperative intra-atrial arrhythmia case study. IEEE Trans Inf Technol Biomed 2001; 5:225-35. [PMID: 11550844 DOI: 10.1109/4233.945293] [Citation(s) in RCA: 7] [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] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Clinical medicine is facing a challenge of knowledge discovery from the growing volume of data. In this paper, a data mining algorithm (G-algorithm) is proposed for extraction of robust rules that can be used in clinical practice for better understanding and prevention of unwanted medical events. The G-algorithm is applied to the data set obtained for children born with a malformation of the heart (univentricular heart). As the result of the Fontan surgical procedure, designed to palliate the children, 10%-35% of patients postoperatively develop an arrhythmia known as the intra-atrial reentrant tachycardia. There is an obvious need to identify the children that may develop the tachycardia before the surgery is performed. Prior attempts to identify such children with statistical techniques have been unrewarding. The G-algorithm discussed in this paper shows that there exists an unambiguous relationship between measurable features and the tachycardia. The data set used in this study shows that, for 78.08% of infants, the occurrence of tachycardia can be accurately predicted. The authors' prior computational experience with diverse medical data sets indicates that the percentage of accurate predictions may become even higher if data on additional features is collected for a larger data set.
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Affiliation(s)
- A Kusiak
- Intelligent Systems Laboratory, The University of Iowa, Iowa City 52242-1527, USA
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Abstract
OBJECTIVES This study outlines the clinical course, treatment and the late outcome of infants and children with multifocal atrial tachycardia (MAT). BACKGROUND Multifocal atrial tachycardia is defined by three distinct P-waveforms, irregular P-P intervals, isoelectric baseline between P-waves and rapid rate on an electrocardiogram. Several smaller prior reports have described pediatric patients with MAT, but their long-term outcome has not been fully assessed. METHODS The clinical records, echocardiograms and long-term follow-up of patients with MAT were reviewed and compared to previous reports of MAT. RESULTS Fourteen boys and seven girls (median age 1.8 months) presented with MAT. At diagnosis, six patients had respiratory illness, of whom two were critical. Ten were asymptomatic. Seven patients had structural heart disease (SHD), one of whom died. Four of 15 patients (27%) with echocardiograms had diminished ventricular function. Ventricular rates were 111 to 253 beats/min (mean 181 beats/min). Median duration of the arrhythmia was 4.9 months (mean 6.7 months). Electrical cardioversion was attempted in 4 patients without success and 15 patients received antiarrhythmic medication. Seventeen patients were followed for a mean of 60 months. Four patients were lost to follow-up. There were no late arrhythmias. CONCLUSIONS The majority of children with MAT are healthy infants under one year of age; a few may exhibit mild to life-threatening cardiorespiratory disease. Less often, MAT accompanies SHD. Mild ventricular dysfunction may be observed in the presence of MAT, but symptoms are few and resolution is generally complete. Response to antiarrhythmic agents is mixed, and cardioversion is of no avail. Finally, long-term cardiovascular and developmental outcome depends principally on underlying condition; for otherwise healthy children, it is excellent.
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Affiliation(s)
- D J Bradley
- University of Michigan Congenital Heart Center, and Department of Pediatrics, University of Michigan, Ann Arbor, USA.
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Vogel T, Kaltenbach G, Martin-Hunyadi C, Heitz D, Dick M, Kiesmann M, Berthel M, Kuntzmann F. Prévalence des interactions médicamenteuses à l'admission en médecine interne gériatrie. Rev Med Interne 2001. [DOI: 10.1016/s0248-8663(01)83527-x] [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: 10/27/2022]
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Law IH, Fischbach PS, LeRoy S, Lloyd TR, Rocchini AP, Dick M. Access to the left atrium for delivery of radiofrequency ablation in young patients: retrograde aortic vs transseptal approach. Pediatr Cardiol 2001; 22:204-9. [PMID: 11343143 DOI: 10.1007/s002460010204] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [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: 11/28/2022]
Abstract
Reported experience with the transseptal approach to the left atrium for delivery of radiofrequency energy in the young patient is limited. To compare two approaches for radiofrequency ablation (RFA) in the left atrium we reviewed our experience from January 1, 1991, through February 1, 1999, in 154 procedures performed on 136 patients (mean age 12.2 years). The patients were grouped by either the retrograde aortic route (R, n = 30) or the transseptal atrial route (T, n = 106). No significant differences were found in age, weight, height, supraventricular tachycardia cycle length, or electrocardiograph characteristics (manifest vs concealed accessory pathway) between the two approaches. Comparison of the transseptal group to the retrograde aortic group revealed a significant difference in the number of catheters (mean = 4 R vs 3 T, p < 0.0001), total fluoroscopic time (71.3 min R vs 43.0 min T, p = 0.0007), diagnostic fluoroscopic time (40.2 min R vs 16.6 min T, p < 0.0001), ablation fluoroscopic time (44.7 min R vs 25.3 min T, p = 0.019), and procedure time (5.0 hours R vs 4.1 hours T, p < 0.0001). No significant difference was found in success rate, number of radiofrequency applications, or major complication rate. These data suggest that although outcomes and major complication rates are similar for the two groups, the use of fewer catheters and shorter fluoroscopic times warrant consideration of the transseptal atrial approach in young patients.
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Affiliation(s)
- I H Law
- University of Michigan Congenital Heart Center, C. S. Mott Children's Hospital and the Department of Pediatrics, University of Michigan Health Systems, Ann Arbor, MI 48109, USA
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Abstract
Comprehensive electrophysiologic study with radiofrequency ablation requires a number of intracardiac catheters. To reduce the number of catheters placed in children, the authors evaluated a series of customized catheters that combined the functions of two catheters. The customized 6F catheter contains eight electrodes placed in pairs at 4, 5, 6, 7, or 8 cm from the tip for recording the His electrogram and at the tip for right ventricular pacing. The amplitude of the bundle of His potential recorded through the His right ventricular apex (RVA) catheter (n = 63) and the ventricular pacing threshold (in mA) (n = 48) were measured and compared to the maximal bundle of His potential recorded with a 6F hexapolar catheter in 24 and 13 other patients, respectively. The relationship between the distance from the distal electrode pair at the tip and the third electrode from the tip (the His/RVA distance) and patient size was analyzed in 42 patients. Following the initial study in the 90 patients, the selection of the optimal His/RVA catheter for 19 patients was determined by examining the regression plots derived from the first group of 90 patients. The measured His/RVA distance was then determined by noting the His/RVA distance of the catheter used. Regression analysis was then used to evaluate the fit between the predicted His/RVA distance based on weight, height, or body surface area (BSA) and the observed His/RVA distance. The maximal bundle of His electrogram measured in the two groups using the His/RVA catheter was compared. To evaluate catheter stability during the study, the amplitude of the maximal His potential was measured in the 19 patients at the onset, midpoint, and end of the study. The maximal His potential recorded through the octapolar catheter (0.21 mV) was significantly (P < .04) greater than that recorded through the hexapolar catheter (0.10 mV). The mean ventricular threshold measured through the octapolar catheter (0.44 mA) was significantly (P < .001) less than that measured through the hexapolar catheter (1.13 mA). There was a significant (P < .0001) correlation between BSA, weight, and height and the His/RVA distance. There was no significant difference in the mean maximal amplitude of the His potential (0.21 +/- 0.31 mV vs 0.15 +/- 0.12 mV) recorded through the His/RVA catheter between the two groups. The His/RVA distance estimated by weight, when plotted against the measured distance, demonstrated a good correlation (r = .84) between the expected His/RVA distance based on the subject's weight and that actually observed. In 18 of 19 subjects, the first catheter based on the patient's weight (in kilograms) predicted the appropriate and only catheter used. There was no significant difference in the mean maximal bundle of His electrogram recorded at the beginning of the study (0.15 +/- 0.12 mV), midway into the study (0.15 +/- 0.11 mV), and at the end (0.13 +/- 0.13 mV); however, there was extensive variation within individuals and over time. These data support the recording of a stable, high-quality bundle of His electrogram and RVA pacing through a single catheter system and, hence, have important, practical implications for invasive electrophysiologic studies in children.
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Affiliation(s)
- M Dick
- Division of Pediatric Cardiology, C.S. Mott Children's Hospital, Ann Arbor, Michigan, USA
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Law IH, Fischbach PS, Goldberg C, Mosca RS, Bove EL, Lloyd TR, Rocchini AP, Dick M. Inducibility of intra-atrial reentrant tachycardia after the first two stages of the Fontan sequence. J Am Coll Cardiol 2001; 37:231-7. [PMID: 11153744 DOI: 10.1016/s0735-1097(00)01090-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
OBJECTIVES We sought to examine the incidence and possible factors for inducible intra-atrial reentrant tachycardia (IART) in a group of patients after two stages of the Fontan sequence but before the operation. BACKGROUND Intra-atrial reentrant tachycardia occurs in 10% to 40% of patients after the Fontan operation. No data are available regarding the potential for IART after the first two stages of the Fontan sequence but before the operation. METHODS The IART induction protocol included programmed extrastimulation and rapid atrial pacing, with and without isoproterenol. RESULTS The median age of the study group (n = 44, 27 males) was 1.7 years (range 1.2 to 5.2). Forty patients were in sinus rhythm. Twelve patients (27%) had inducible, sustained (>1 min) IART. Three patients (8%) had inducible, nonsustained IART. Bivariate analysis revealed that patients with sustained IART were significantly older at their second operation (median 0.54 vs. 0.40 years, p = 0.05). Multivariate logistic modeling revealed that older age (> or =0.55 years) at the second palliative operation (p = 0.04), older age (> or =1.95 years) at evaluation before the Fontan sequence (p = 0.04) and female gender (p = 0.03) were independently associated with sustained IART. A trend toward a greater frequency of sustained IART was seen in those patients with moderate or severe atrioventricular valve regurgitation (p = 0.07) and in those with resection of the atrial septum (p = 0.06). CONCLUSIONS The rate of inducible, sustained IART in a group of patients before the Fontan operation is 27% and is associated with older age at the time of second-stage palliation, older age at pre-Fontan evaluation and female gender.
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Affiliation(s)
- I H Law
- University of Michigan Congenital Heart Center and Department of Pediatrics, University of Michigan Health Systems, Ann Arbor 48109-0204, USA
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Fischbach PS, Law IH, Dick M, Leroy S, Mosca RS, Serwer GA. Use of a single coil transvenous electrode with an abdominally placed implantable cardioverter defibrillator in children. Pacing Clin Electrophysiol 2000; 23:884-7. [PMID: 10833710 DOI: 10.1111/j.1540-8159.2000.tb00859.x] [Citation(s) in RCA: 14] [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] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
While transvenous defibrillator electrode placement avoiding a thoracotomy is preferable, electrode size, a large intercoil spacing, and the need for subclavicular device placement preclude this approach in most children. We investigated a single RV coil to an abdominally placed active can ICD device. Five children ages 8-16 years (weight 21-50 kg, mean 35 kg) underwent ICD placement. Placement of a single coil Medtronic model 6932 or 6943 electrode was performed via the left subclavian vein approach and the electrode positioned in the RV apex with the coil lying along the RV diaphragmatic surface. The ICD (Medtronic Micro Jewel II model 7223 Cx) was implanted in a left abdominal pocket with the lead tunneled from the infraclavicular region to the pocket. Implant DFTs were < or = 15 J using a biphasic waveform. DFTs rechecked within 3-month postimplant were unchanged. Lead impedance at implant ranged from 38 to 56 omega, mean 51 omega. Follow-up was 3-21 months (total 82 months) with no electrode dislodgment, lead fractures, or inappropriate discharges. Two of the five patients have had successful appropriate ICD discharges. Transvenous ICD electrode placement can be performed in children as small as 20 kg with the device implanted in a cosmetically acceptable abdominal pocket that is well tolerated. Excellent DFTs can be achieved. This approach avoids a thoracotomy in all but the smallest child, does not require subclavicular placement of the device, and avoids use of a second intravascular coil.
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Affiliation(s)
- P S Fischbach
- University of Michigan Congenital Heart Center, University of Michigan Health System, Ann Arbor, USA.
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45
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Abstract
OBJECTIVE The purpose of this study is to review the clinical course of persistent junctional reciprocating tachycardia (PJRT) in 21 patients spanning a wide age range to examine the electrophysiologic characteristics of the conduction system in these patients with PJRT, particularly in regards to its incessant nature and to evaluate the long-term response to radiofrequency ablation. BACKGROUND Persistent junctional reciprocating tachycardia is uncommon, occurring in 1% of patients with supraventricular tachycardia. Its presentation, course and treatment are incompletely characterized. METHODS The clinical, electrocardiographic, electrophysiologic and echocardiographic data of 21 patients with PJRT were reviewed. RESULTS In 9 of these 21 patients, the mean tachycardia cycle length increased significantly (p < 0.0001) as the patients grew, from a mean tachycardia cycle length of 308+/-64 ms in the patients less than 2 years, 414+/-57 ms in the patients between 2 years and 5 years, to 445+/-57 ms in the patients greater than 5 years, primarily due to slowing of retrograde conduction in the accessory pathway. Persistent junctional reciprocating tachycardia was associated with impaired ventricular function in 11, improving spontaneously in 4 and, after successful ablation of the accessory pathway, in 7. All patients except one were uncontrolled on one or more medications. Ablation of the accessory pathway was successful in 19 of 21 patients. CONCLUSIONS We conclude that PJRT is characterized by an onset in early childhood and by an age-related prolongation of the tachycardia cycle length mediated primarily through conduction delay in the concealed, retrogradely conducting accessory pathway. Ablation of the accessory pathway provides definitive treatment for PJRT.
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MESH Headings
- Adolescent
- Adult
- Aged
- Aged, 80 and over
- Anti-Arrhythmia Agents/therapeutic use
- Catheter Ablation
- Child
- Child, Preschool
- Electrocardiography, Ambulatory
- Follow-Up Studies
- Humans
- Infant
- Male
- Middle Aged
- Remission, Spontaneous
- Retrospective Studies
- Tachycardia, Paroxysmal/complications
- Tachycardia, Paroxysmal/physiopathology
- Tachycardia, Paroxysmal/therapy
- Tachycardia, Supraventricular/complications
- Tachycardia, Supraventricular/physiopathology
- Tachycardia, Supraventricular/therapy
- Ventricular Dysfunction/complications
- Ventricular Dysfunction/physiopathology
- Ventricular Dysfunction/therapy
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Affiliation(s)
- P C Dorostkar
- Department of Pediatrics, University of Michigan Health System, Ann Arbor, USA
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46
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Abstract
We measured the dimensions of Koch's triangle in children with normal intracardiac anatomy to determine the relation between the size of the triangle of Koch and patient age, weight, height, and body surface area. We found that the dimensions of Koch's triangle varies significantly and directly with patient age and body habitus in this pediatric population.
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Affiliation(s)
- C S Goldberg
- Michigan Congenital Heart Center, C.S. Mott Children's Hospital, Department of Pediatrics, University of Michigan, Ann Arbor 48109-0204, USA.
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Taussig IM, Dick M, Teng E, Davis DS, Kempler D. Screening for depression in four ethnic groups: Comparisons between the Geriatric Depression Scale (GDS) and the Center for Epidemiological Studies Scale (CES-D). Arch Clin Neuropsychol 1999. [DOI: 10.1093/arclin/14.1.66a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Abstract
A group of 317 healthy participants between 54 and 99 years of age performed a verbal fluency task. The participants included Chinese, Hispanic, and Vietnamese immigrants, as well as White and African American English speakers. They were given 1 min to name as many animals as possible in their native language. The results showed that more animal names were produced by younger people and those with more education. Language background was also an important factor: The Vietnamese produced the most animal names and the Spanish speakers produced the fewest. The exaggerated difference between these two groups is attributed to the fact that Vietnamese animal names are short (predominantly 1 syllable) while the Spanish animal names are longer than any other language in this study (2 and 3 syllables per word). Finally, although the ethnic groups named different animals, and appeared to vary in the variety of animal names they used, these factors did not affect overall verbal fluency performance.
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Affiliation(s)
- D Kempler
- Department of Otolaryngology, School of Medicine, School of Gerontology, University of Southern California, USA.
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Flancbaum L, Dick M, Choban PS, Dasta JP. Effects of low-dose dopamine on urine output in oliguric, critically ill, renal transplant patients. Clin Transplant 1998; 12:256-9. [PMID: 9642519] [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: 02/07/2023]
Abstract
UNLABELLED Low-dose dopamine (LD-DA) has been used extensively to increase urine output (UO) in critically ill patients. These effects have recently been documented in patients with normal and mildly abnormal renal function. The purpose of this study was to quantitate the effects of LD-DA on UO and urineNa (UNa) excretion in renal transplant (RT) patients, and thereby evaluate the effects of LD-DA on the denervated kidney. METHODS Five RT patients and 7 non-transplant controls, hospitalized in the surgical intensive care unit (SICU), with serum creatinine (serum Cr) < 2 mg/dL who were oliguric (UO < 0.5 mL/kg/h), received LD-DA (2.5 micrograms/kg/min). None received other diuretics within 12 h, and all had pulmonary artery occlusion pressure (PAOP) > 10 mmHg and CI > 3.0 L/min/m2. UO was measured hourly and averaged for 2 h pre and 6 h during LD-DA. All data are mean +/- SD. RESULTS APACHE II (14 +/- 4), CI (4.1 +/- 1.2 L/min/m2), PAOP (15 +/- 4 mmHg), HR (98 +/- 16/min), and MAP (83 +/- 10 mmHg) were similar between groups and did not change during LD-DA therapy. Initial serum Cr in the RT group (1.6 +/- 0.4 mg/dL) was greater than that in controls (0.9 +/- 0.24 mg/dL), p < 0.05. Initial UO [0.26 +/- 0.10 mL/kg/h (RT) and 0.31 +/- 0.12 mL/kg/h (controls)] and initial UNa [8 +/- 62 meq/L (RT) and 54 +/- 28 meq/L (controls)] were not different. Urine output increased significantly compared with baseline in both groups [final UO 0.55 +/- 0.14 mL/kg/h (RT) and 0.96 +/- 0.41 mL/kg/h (controls)]. Final UNa [72 +/- 37 meq/L (RT) and 99 +/- 56 meq/L (controls)] were not different from each other or from baseline. CONCLUSIONS LD-DA increases UO, but not UNa excretion, in RT patients with oliguria, comparably to controls. These data suggest that this effect is predominantly mediated by dopaminergic receptors, since the transplanted kidney is denervated and there were no significant associated changes in hemodynamic parameters during the study.
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Affiliation(s)
- L Flancbaum
- Department of Surgery, Ohio State University, Columbus 43210, USA.
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Zeng D, Dick M, Cheng L, Amano M, Dejbakhsh-Jones S, Huie P, Sibley R, Strober S. Subsets of transgenic T cells that recognize CD1 induce or prevent murine lupus: role of cytokines. J Exp Med 1998; 187:525-36. [PMID: 9463403 PMCID: PMC2212154 DOI: 10.1084/jem.187.4.525] [Citation(s) in RCA: 67] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/1997] [Revised: 11/24/1997] [Indexed: 02/06/2023] Open
Abstract
T cells with T cell receptor (TCR) transgenes that recognized CD1 on syngeneic B cells stimulated B cells to secrete immunoglobulins in vitro. The CD4+, CD8+, or CD4-CD8- T cells from the spleen of the TCR transgenic BALB/c donors induced lupus with anti-double stranded DNA antibodies, proteinuria, and immune complex glomerulonephritis in irradiated BALB/c nude mice reconstituted with nude bone marrow. Injection of purified CD4-CD8- T cells from the marrow of transgenic donors prevented the induction of lupus by the transgenic T cells. Transgenic T cells that induced lupus secreted large amounts of interferon (IFN)-gamma and little interleukin (IL)-4, and those that prevented lupus secreted large amounts of IL-4 and little IFN-gamma or IL-10.
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MESH Headings
- Animals
- Antigens, CD1/immunology
- Bone Marrow Cells/immunology
- CD4-Positive T-Lymphocytes/immunology
- CD8-Positive T-Lymphocytes/immunology
- Cytokines/metabolism
- Cytokines/physiology
- Disease Models, Animal
- Interferon-gamma/metabolism
- Interleukin-4/metabolism
- Lupus Erythematosus, Systemic/etiology
- Lupus Erythematosus, Systemic/immunology
- Mice
- Mice, Inbred BALB C
- Mice, Nude
- Mice, Transgenic
- Receptors, Antigen, T-Cell, alpha-beta/biosynthesis
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Affiliation(s)
- D Zeng
- Division of Immunology and Rheumatology, Stanford University School of Medicine, Stanford, California 94305-5111, USA
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