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Nikkonen S, Somaskandhan P, Korkalainen H, Kainulainen S, Terrill PI, Gretarsdottir H, Sigurdardottir S, Olafsdottir KA, Islind AS, Óskarsdóttir M, Arnardóttir ES, Leppänen T. Multicentre sleep-stage scoring agreement in the Sleep Revolution project. J Sleep Res 2024; 33:e13956. [PMID: 37309714 PMCID: PMC10909532 DOI: 10.1111/jsr.13956] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Revised: 05/04/2023] [Accepted: 05/11/2023] [Indexed: 06/14/2023]
Abstract
Determining sleep stages accurately is an important part of the diagnostic process for numerous sleep disorders. However, as the sleep stage scoring is done manually following visual scoring rules there can be considerable variation in the sleep staging between different scorers. Thus, this study aimed to comprehensively evaluate the inter-rater agreement in sleep staging. A total of 50 polysomnography recordings were manually scored by 10 independent scorers from seven different sleep centres. We used the 10 scorings to calculate a majority score by taking the sleep stage that was the most scored stage for each epoch. The overall agreement for sleep staging was κ = 0.71 and the mean agreement with the majority score was 0.86. The scorers were in perfect agreement in 48% of all scored epochs. The agreement was highest in rapid eye movement sleep (κ = 0.86) and lowest in N1 sleep (κ = 0.41). The agreement with the majority scoring varied between the scorers from 81% to 91%, with large variations between the scorers in sleep stage-specific agreements. Scorers from the same sleep centres had the highest pairwise agreements at κ = 0.79, κ = 0.85, and κ = 0.78, while the lowest pairwise agreement between the scorers was κ = 0.58. We also found a moderate negative correlation between sleep staging agreement and the apnea-hypopnea index, as well as the rate of sleep stage transitions. In conclusion, although the overall agreement was high, several areas of low agreement were also found, mainly between non-rapid eye movement stages.
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Affiliation(s)
- Sami Nikkonen
- Department of Technical PhysicsUniversity of Eastern FinlandKuopioFinland
- Diagnostic Imaging CenterKuopio University HospitalKuopioFinland
| | - Pranavan Somaskandhan
- School of Information Technology and Electrical EngineeringThe University of QueenslandBrisbaneQueenslandAustralia
| | - Henri Korkalainen
- Department of Technical PhysicsUniversity of Eastern FinlandKuopioFinland
- Diagnostic Imaging CenterKuopio University HospitalKuopioFinland
| | - Samu Kainulainen
- Department of Technical PhysicsUniversity of Eastern FinlandKuopioFinland
- Diagnostic Imaging CenterKuopio University HospitalKuopioFinland
| | - Philip I. Terrill
- School of Information Technology and Electrical EngineeringThe University of QueenslandBrisbaneQueenslandAustralia
| | - Heidur Gretarsdottir
- Reykjavik University Sleep Institute, School of TechnologyReykjavik UniversityReykjavikIceland
| | - Sigridur Sigurdardottir
- Reykjavik University Sleep Institute, School of TechnologyReykjavik UniversityReykjavikIceland
| | | | - Anna Sigridur Islind
- Reykjavik University Sleep Institute, School of TechnologyReykjavik UniversityReykjavikIceland
- Department of Computer ScienceReykjavík UniversityReykajvíkIceland
| | - María Óskarsdóttir
- Reykjavik University Sleep Institute, School of TechnologyReykjavik UniversityReykjavikIceland
- Department of Computer ScienceReykjavík UniversityReykajvíkIceland
| | - Erna Sif Arnardóttir
- Reykjavik University Sleep Institute, School of TechnologyReykjavik UniversityReykjavikIceland
| | - Timo Leppänen
- Department of Technical PhysicsUniversity of Eastern FinlandKuopioFinland
- Diagnostic Imaging CenterKuopio University HospitalKuopioFinland
- School of Information Technology and Electrical EngineeringThe University of QueenslandBrisbaneQueenslandAustralia
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Somaskandhan P, Leppänen T, Terrill PI, Sigurdardottir S, Arnardottir ES, Ólafsdóttir KA, Serwatko M, Sigurðardóttir SÞ, Clausen M, Töyräs J, Korkalainen H. Deep learning-based algorithm accurately classifies sleep stages in preadolescent children with sleep-disordered breathing symptoms and age-matched controls. Front Neurol 2023; 14:1162998. [PMID: 37122306 PMCID: PMC10140398 DOI: 10.3389/fneur.2023.1162998] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2023] [Accepted: 03/23/2023] [Indexed: 05/02/2023] Open
Abstract
Introduction Visual sleep scoring has several shortcomings, including inter-scorer inconsistency, which may adversely affect diagnostic decision-making. Although automatic sleep staging in adults has been extensively studied, it is uncertain whether such sophisticated algorithms generalize well to different pediatric age groups due to distinctive EEG characteristics. The preadolescent age group (10-13-year-olds) is relatively understudied, and thus, we aimed to develop an automatic deep learning-based sleep stage classifier specifically targeting this cohort. Methods A dataset (n = 115) containing polysomnographic recordings of Icelandic preadolescent children with sleep-disordered breathing (SDB) symptoms, and age and sex-matched controls was utilized. We developed a combined convolutional and long short-term memory neural network architecture relying on electroencephalography (F4-M1), electrooculography (E1-M2), and chin electromyography signals. Performance relative to human scoring was further evaluated by analyzing intra- and inter-rater agreements in a subset (n = 10) of data with repeat scoring from two manual scorers. Results The deep learning-based model achieved an overall cross-validated accuracy of 84.1% (Cohen's kappa κ = 0.78). There was no meaningful performance difference between SDB-symptomatic (n = 53) and control subgroups (n = 52) [83.9% (κ = 0.78) vs. 84.2% (κ = 0.78)]. The inter-rater reliability between manual scorers was 84.6% (κ = 0.78), and the automatic method reached similar agreements with scorers, 83.4% (κ = 0.76) and 82.7% (κ = 0.75). Conclusion The developed algorithm achieved high classification accuracy and substantial agreements with two manual scorers; the performance metrics compared favorably with typical inter-rater reliability between manual scorers and performance reported in previous studies. These suggest that our algorithm may facilitate less labor-intensive and reliable automatic sleep scoring in preadolescent children.
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Affiliation(s)
- Pranavan Somaskandhan
- School of Information Technology and Electrical Engineering, The University of Queensland, Brisbane, QLD, Australia
- *Correspondence: Pranavan Somaskandhan,
| | - Timo Leppänen
- School of Information Technology and Electrical Engineering, The University of Queensland, Brisbane, QLD, Australia
- Department of Technical Physics, University of Eastern Finland, Kuopio, Finland
- Diagnostic Imaging Center, Kuopio University Hospital, Kuopio, Finland
| | - Philip I. Terrill
- School of Information Technology and Electrical Engineering, The University of Queensland, Brisbane, QLD, Australia
| | - Sigridur Sigurdardottir
- Reykjavik University Sleep Institute, School of Technology, Reykjavik University, Reykjavik, Iceland
| | - Erna Sif Arnardottir
- Reykjavik University Sleep Institute, School of Technology, Reykjavik University, Reykjavik, Iceland
- Internal Medicine Services, Landspitali–The National University Hospital of Iceland, Reykjavik, Iceland
| | - Kristín A. Ólafsdóttir
- Reykjavik University Sleep Institute, School of Technology, Reykjavik University, Reykjavik, Iceland
| | - Marta Serwatko
- Department of Clinical Engineering, Landspitali University Hospital, Reykjavik, Iceland
| | - Sigurveig Þ. Sigurðardóttir
- Department of Immunology, Landspitali University Hospital, Reykjavik, Iceland
- Faculty of Medicine, University of Iceland, Reykjavik, Iceland
| | - Michael Clausen
- Department of Allergy, Landspitali University Hospital, Reykjavik, Iceland
- Children's Hospital Reykjavik, Reykjavik, Iceland
| | - Juha Töyräs
- School of Information Technology and Electrical Engineering, The University of Queensland, Brisbane, QLD, Australia
- Department of Technical Physics, University of Eastern Finland, Kuopio, Finland
- Science Service Center, Kuopio University Hospital, Kuopio, Finland
| | - Henri Korkalainen
- Department of Technical Physics, University of Eastern Finland, Kuopio, Finland
- Diagnostic Imaging Center, Kuopio University Hospital, Kuopio, Finland
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Rusanen M, Huttunen R, Korkalainen H, Myllymaa S, Toyras J, Myllymaa K, Sigurdardottir S, Olafsdottir KA, Leppanen T, Arnardottir ES, Kainulainen S. Generalizable Deep Learning-based Sleep Staging Approach for Ambulatory Textile Electrode Headband Recordings. IEEE J Biomed Health Inform 2023; PP. [PMID: 37022272 DOI: 10.1109/jbhi.2023.3240437] [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: 02/01/2023]
Abstract
Reliable, automated, and user-friendly solutions for the identification of sleep stages in home environment are needed in various clinical and scientific research settings. Previously we have shown that signals recorded with an easily applicable textile electrode headband (FocusBand, T 2 Green Pty Ltd) contain characteristics similar to the standard electrooculography (EOG, E1-M2). We hypothesize that the electroencephalographic (EEG) signals recorded using the textile electrode headband are similar enough with standard EOG in order to develop an automatic neural network-based sleep staging method that generalizes from diagnostic polysomnographic (PSG) data to ambulatory sleep recordings of textile electrode-based forehead EEG. Standard EOG signals together with manually annotated sleep stages from clinical PSG dataset (n = 876) were used to train, validate, and test a fully convolutional neural network (CNN). Furthermore, ambulatory sleep recordings including a standard set of gel-based electrodes and the textile electrode headband were conducted for 10 healthy volunteers at their homes to test the generalizability of the model. In the test set (n = 88) of the clinical dataset, the model's accuracy for 5-stage sleep stage classification was 80% (κ = 0.73) using only the single-channel EOG. The model generalized well for the headband-data, reaching 82% (κ = 0.75) overall sleep staging accuracy. In comparison, accuracy of the model was 87% (κ = 0.82) in home recordings using the standard EOG. In conclusion, the CNN model shows potential on automatic sleep staging of healthy individuals using a reusable electrode headband in a home environment.
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Affiliation(s)
- M. Rusanen
- Department of Technical Physics, University of Eastern Finland, Kuopio, Finland
| | - R. Huttunen
- Department of Technical Physics, University of Eastern Finland, Kuopio, Finland
| | - H. Korkalainen
- Department of Technical Physics, University of Eastern Finland, Kuopio, Finland
| | - S. Myllymaa
- Department of Technical Physics, University of Eastern Finland, Kuopio, Finland
| | - J. Toyras
- Department of Technical Physics, University of Eastern Finland and Science Service Center, Kuopio University Hospital, Kuopio, Finland
| | - K. Myllymaa
- Diagnostic Imaging Center, Kuopio University Hospital, Kuopio, Finland
| | - S. Sigurdardottir
- Reykjavik University Sleep Institute, School of Technology, Reykjavik University, Reykjavik, Iceland
| | - K. A. Olafsdottir
- Reykjavik University Sleep Institute, School of Technology, Reykjavik University, Reykjavik, Iceland
| | - T. Leppanen
- Department of Technical Physics, University of Eastern Finland, Kuopio, Finland
| | - E. S. Arnardottir
- Landspitali–The National University Hospital of Iceland, Reykjavik, Iceland
| | - S. Kainulainen
- Department of Technical Physics, University of Eastern Finland, Kuopio, Finland
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Rusanen M, Huttunen R, Korkalainen H, Töyräs J, Myllymaa S, Leppänen T, Sigurdardottir S, Arnardottir E, Kainulainen S. Deep Learning Enables Automatic Sleep Staging from Textile Electrode-Based Home Sleep Recordings. Sleep Med 2022. [DOI: 10.1016/j.sleep.2022.05.795] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Dolberg P, Sigurdardottir S, Trummer U. AGEISM IN IMMIGRATION POLICIES. Innov Aging 2017. [DOI: 10.1093/geroni/igx004.3926] [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: 11/13/2022] Open
Affiliation(s)
- P. Dolberg
- Ben-Gurion University of the Negev, Beer-Sheva, Israel,
| | | | - U. Trummer
- Center for Health and Migration, Vienna, Austria
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Hellstrøm T, Westlye LT, Sigurdardottir S, Brunborg C, Soberg HL, Holthe Ø, Server A, Lund MJ, Andreassen OA, Andelic N. Longitudinal changes in brain morphology from 4 weeks to 12 months after mild traumatic brain injury: Associations with cognitive functions and clinical variables. Brain Inj 2017; 31:674-685. [DOI: 10.1080/02699052.2017.1283537] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
- T. Hellstrøm
- Department of Physical Medicine and Rehabilitation, Oslo University Hospital, Oslo, Norway
| | - L. T. Westlye
- KG Jebsen Centre for Psychosis Research/Norwegian Centre for Mental Disorder Research (NORMENT), Division of Mental Health and Addiction, Oslo University Hospital, Oslo, Norway
- Department of Psychology, University of Oslo, Oslo, Norway
| | - S. Sigurdardottir
- Department of Research, Sunnaas Rehabilitation Hospital, Nesoddtangen, Norwa
- CHARM Resarch Centre for Habilitation and Rehabilitation Models & Services, Oslo, Norway
| | - C. Brunborg
- Oslo Centre for Biostatistics and Epidemiology, Research Support Services, Oslo University Hospital, Oslo, Norway
| | - H. L. Soberg
- Department of Physical Medicine and Rehabilitation, Oslo University Hospital, Oslo, Norway
| | - Ø. Holthe
- Department of Physical Medicine and Rehabilitation, Oslo University Hospital, Oslo, Norway
| | - A. Server
- Department of Radiology and Nuclear Medicine, Oslo University Hospital, Oslo, Norway
| | - M. J. Lund
- KG Jebsen Centre for Psychosis Research/Norwegian Centre for Mental Disorder Research (NORMENT), Division of Mental Health and Addiction, Oslo University Hospital, Oslo, Norway
| | - O. A. Andreassen
- KG Jebsen Centre for Psychosis Research/Norwegian Centre for Mental Disorder Research (NORMENT), Division of Mental Health and Addiction, Oslo University Hospital, Oslo, Norway
| | - N. Andelic
- Department of Physical Medicine and Rehabilitation, Oslo University Hospital, Oslo, Norway
- CHARM Resarch Centre for Habilitation and Rehabilitation Models & Services, Oslo, Norway
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Norup A, Egeland J, Løvstad M, Nybo T, Persson BA, Rivera D, Schanke AK, Sigurdardottir S, Arango-Lasprilla JC. Education, training, and practice among nordic neuropsychologists. Results from a professional practices survey. Clin Neuropsychol 2017; 31:20-41. [PMID: 28361565 DOI: 10.1080/13854046.2017.1291857] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
OBJECTIVE To investigate sociodemographic characteristics, clinical and academic training, work setting and salary, clinical activities, and salary and job satisfaction among practicing neuropsychologists in four Nordic countries. METHODS 890 neuropsychologists from Denmark, Finland, Norway, and Sweden participated in an internet-based survey between December 2013 and June 2015. RESULTS Three-fourths (76%) of the participants were women, with a mean age of 47 years (range 24-79). In the total sample, 11% earned a PhD and 42% were approved as specialists in neuropsychology (equivalent to board certification in the U.S.). Approximately 72% worked full-time, and only 1% were unemployed. Of the participants, 66% worked in a hospital setting, and 93% had conducted neuropsychological assessments during the last year. Attention deficit hyperactivity disorder, learning disability, and intellectual disability were the most common conditions seen by neuropsychologists. A mean income of 53,277 Euros was found. Neuropsychologists expressed greater job satisfaction than income satisfaction. Significant differences were found between the Nordic countries. Finnish neuropsychologists were younger and worked more hours every week. Fewer Swedish neuropsychologists had obtained specialist approval and fewer worked full-time in neuropsychology positions. Danish and Norwegian neuropsychologists earned more money than their Nordic colleagues. CONCLUSION This is the first professional practice survey of Nordic neuropsychologists to provide information about sociodemographic characteristics and work setting factors. Despite the well-established guidelines for academic and clinical education, there are relevant differences between the Nordic countries. The results of the study offer guidance for refining the development of organized and highly functioning neuropsychological specialty practices in Nordic countries.
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Affiliation(s)
- A Norup
- a Department of Neurology , National Study of Young Brain Injury Survivors, Rigshospitalet, Copenhagen University Hospital , Copenhagen , Denmark
| | - J Egeland
- b Division of Mental Health & Addiction , Vestfold Hospital Trust , Tønsberg , Norway.,c Department of Psychology , University of Oslo , Oslo , Norway
| | - M Løvstad
- c Department of Psychology , University of Oslo , Oslo , Norway.,d Research Department , Sunnaas Rehabilitation Hospital , Nesoddtangen , Norway
| | - T Nybo
- e Clinical Neurosciences, Unit of Neuropsychology' , University of Helsinki and Helsinki University Hospital , Helsinki , Finland
| | - B A Persson
- f Department of Psychology , Linnaeus University , Växjö , Sweden
| | - D Rivera
- g BioCruces Health Research Institute, Cruces University Hospital , Barakaldo , Spain
| | - A-K Schanke
- c Department of Psychology , University of Oslo , Oslo , Norway.,d Research Department , Sunnaas Rehabilitation Hospital , Nesoddtangen , Norway
| | - S Sigurdardottir
- d Research Department , Sunnaas Rehabilitation Hospital , Nesoddtangen , Norway.,h Faculty of Medicine , Institute of Health and Society, Research Centre for Habilitation and Rehabilitation Models and Services (CHARM), University of Oslo , Oslo , Norway
| | - J C Arango-Lasprilla
- g BioCruces Health Research Institute, Cruces University Hospital , Barakaldo , Spain.,i IKERBASQUE , Basque Foundation for Science , Bilbao , Spain
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Grabenhenrich LB, Reich A, Bellach J, Trendelenburg V, Sprikkelman AB, Roberts G, Grimshaw KEC, Sigurdardottir S, Kowalski ML, Papadopoulos NG, Quirce S, Dubakiene R, Niggemann B, Fernández-Rivas M, Ballmer-Weber B, van Ree R, Schnadt S, Mills ENC, Keil T, Beyer K. A new framework for the documentation and interpretation of oral food challenges in population-based and clinical research. Allergy 2017; 72:453-461. [PMID: 27670637 PMCID: PMC5324701 DOI: 10.1111/all.13049] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/15/2016] [Indexed: 01/18/2023]
Abstract
BACKGROUND The conduct of oral food challenges as the preferred diagnostic standard for food allergy (FA) was harmonized over the last years. However, documentation and interpretation of challenge results, particularly in research settings, are not sufficiently standardized to allow valid comparisons between studies. Our aim was to develop a diagnostic toolbox to capture and report clinical observations in double-blind placebo-controlled food challenges (DBPCFC). METHODS A group of experienced allergists, paediatricians, dieticians, epidemiologists and data managers developed generic case report forms and standard operating procedures for DBPCFCs and piloted them in three clinical centres. The follow-up of the EuroPrevall/iFAAM birth cohort and other iFAAM work packages applied these methods. RECOMMENDATIONS A set of newly developed questionnaire or interview items capture the history of FA. Together with sensitization status, this forms the basis for the decision to perform a DBPCFC, following a standardized decision algorithm. A generic form including details about severity and timing captures signs and symptoms observed during or after the procedures. In contrast to the commonly used dichotomous outcome FA vs no FA, the allergy status is interpreted in multiple categories to reflect the complexity of clinical decision-making. CONCLUSION The proposed toolbox sets a standard for improved documentation and harmonized interpretation of DBPCFCs. By a detailed documentation and common terminology for communicating outcomes, these tools hope to reduce the influence of subjective judgment of supervising physicians. All forms are publicly available for further evolution and free use in clinical and research settings.
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Affiliation(s)
- L. B. Grabenhenrich
- Institute for Social Medicine, Epidemiology and Health Economics; Charité - Universitätsmedizin Berlin; Berlin Germany
| | - A. Reich
- Institute for Social Medicine, Epidemiology and Health Economics; Charité - Universitätsmedizin Berlin; Berlin Germany
| | - J. Bellach
- Department of Paediatric Pneumology and Immunology; Charité - Universitätsmedizin Berlin; Berlin Germany
| | - V. Trendelenburg
- Department of Paediatric Pneumology and Immunology; Charité - Universitätsmedizin Berlin; Berlin Germany
| | - A. B. Sprikkelman
- Department of Pediatric Pulmonology & Pediatric Allergology; University Medical Center Groningen; Groningen The Netherlands
| | - G. Roberts
- Clinical and Experimental Sciences Academic Units; Faculty of Medicine; University of Southampton; Southampton UK
| | - K. E. C. Grimshaw
- Clinical and Experimental Sciences Academic Units; Faculty of Medicine; University of Southampton; Southampton UK
- Department of Nutrition and Dietetics; Southampton Children's Hospital; Southampton UK
| | - S. Sigurdardottir
- Department of Immunology; Landspitali - The National University Hospital of Iceland; Reykjavik Iceland
| | - M. L. Kowalski
- Department of Clinical Immunology and Allergy; University of Łódź; Łódź Poland
| | - N. G. Papadopoulos
- Institute of Human Development; University of Manchester; Manchester UK
- Allergy Department; 2nd Paediatric Clinic; University of Athens; Athens Greece
| | - S. Quirce
- Department of Allergy; Hospital La Paz Institute for Health Research; Madrid Spain
| | - R. Dubakiene
- Faculty of Medicine; Vilnius University; Vilnius Lithuania
| | - B. Niggemann
- Department of Paediatric Pneumology and Immunology; Charité - Universitätsmedizin Berlin; Berlin Germany
| | | | - B. Ballmer-Weber
- Allergy Unit; Department of Dermatology; University Hospital; Zürich Switzerland
| | - R. van Ree
- Departments of Experimental Immunology and of Otorhinolaryngology; Academic Medical Center; Amsterdam The Netherlands
| | - S. Schnadt
- German Allergy and Asthma Association; Mönchengladbach Germany
| | - E. N. C. Mills
- Institute of Inflammation and Repair; University of Manchester; Manchester UK
| | - T. Keil
- Institute for Social Medicine, Epidemiology and Health Economics; Charité - Universitätsmedizin Berlin; Berlin Germany
| | - K. Beyer
- Department of Paediatric Pneumology and Immunology; Charité - Universitätsmedizin Berlin; Berlin Germany
- Icahn School of Medicine at Mount Sinai; New York NY USA
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Brockow K, Aberer W, Atanaskovic-Markovic M, Bavbek S, Bircher A, Bilo B, Blanca M, Bonadonna P, Burbach G, Calogiuri G, Caruso C, Celik G, Cernadas J, Chiriac A, Demoly P, Oude Elberink JNG, Fernandez J, Gomes E, Garvey LH, Gooi J, Gotua M, Grosber M, Kauppi P, Kvedariene V, Laguna JJ, Makowska J, Mosbech H, Nakonechna A, Papadopolous NG, Ring J, Romano A, Rockmann H, Sargur R, Sedlackova L, Sigurdardottir S, Schnyder B, Storaas T, Torres M, Zidarn M, Terreehorst I. Drug allergy passport and other documentation for patients with drug hypersensitivity - An ENDA/EAACI Drug Allergy Interest Group Position Paper. Allergy 2016; 71:1533-1539. [PMID: 27145347 DOI: 10.1111/all.12929] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/02/2016] [Indexed: 12/27/2022]
Abstract
The strongest and best-documented risk factor for drug hypersensitivity (DH) is the history of a previous reaction. Accidental exposures to drugs may lead to severe or even fatal reactions in sensitized patients. Preventable prescription errors are common. They are often due to inadequate medical history or poor risk assessment of recurrence of drug reaction. Proper documentation is essential information for the doctor to make sound therapeutic decision. The European Network on Drug Allergy and Drug Allergy Interest Group of the European Academy of Allergy and Clinical Immunology have formed a task force and developed a drug allergy passport as well as general guidelines of drug allergy documentation. A drug allergy passport, a drug allergy alert card, a certificate, and a discharge letter after medical evaluation are adequate means to document DH in a patient. They are to be handed to the patient who is advised to carry the documentation at all times especially when away from home. A drug allergy passport should at least contain information on the culprit drug(s) including international nonproprietary name, clinical manifestations including severity, diagnostic measures, potential cross-reactivity, alternative drugs to prescribe, and where more detailed information can be obtained from the issuer. It should be given to patients only after full allergy workup. In the future, electronic prescription systems with alert functions will become more common and should include the same information as in paper-based documentation.
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10
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Xepapadaki P, Fiocchi A, Grabenhenrich L, Roberts G, Grimshaw KEC, Fiandor A, Larco JI, Sigurdardottir S, Clausen M, Papadopoulos NG, Dahdah L, Mackie A, Sprikkelman AB, Schoemaker AA, Dubakiene R, Butiene I, Kowalski ML, Zeman K, Gavrili S, Keil T, Beyer K. Incidence and natural history of hen's egg allergy in the first 2 years of life-the EuroPrevall birth cohort study. Allergy 2016; 71:350-7. [PMID: 26514330 DOI: 10.1111/all.12801] [Citation(s) in RCA: 117] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/25/2015] [Indexed: 01/08/2023]
Abstract
BACKGROUND Parents and health staff perceive hen's egg allergy (HEA) as a common food allergy in early childhood, but the true incidence is unclear because population-based studies with gold-standard diagnostic criteria are lacking. OBJECTIVE To establish the incidence and course of challenge-confirmed HEA in children, from birth until the age of 24 months, in different European regions. METHODS In the EuroPrevall birth cohort study, children with a suspected HEA and their age-matched controls were evaluated in 9 countries, using a standardized protocol including measurement of HE-specific immunoglobulin E-antibodies in serum, skin prick tests, and double-blind, placebo-controlled food challenges (DBPCFC). RESULTS Across Europe, 12 049 newborns were enrolled, and 9336 (77.5%) were followed up to 2 years of age. In 298 children, HEA was suspected and DBPCFC was offered. HEA by age two was confirmed in 86 of 172 challenged children (mean raw incidence 0.84%, 95% confidence interval (95% CI) 0.67-1.03). Adjusted mean incidence of HEA was 1.23% (95% CI 0.98-1.51) considering possible cases among eligible children who were not challenged. Centre-specific incidence ranged from United Kingdom (2.18%, 95% CI 1.27-3.47) to Greece (0.07%). Half of the HE-allergic children became tolerant to HE within 1 year after the initial diagnosis. CONCLUSIONS The largest multinational European birth cohort study on food allergy with gold-standard diagnostic methods showed that the mean adjusted incidence of HEA was considerably lower than previously documented, although differences in incidence rates among countries were noted. Half of the children with documented HEA gained tolerance within 1 year postdiagnosis.
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Affiliation(s)
- P. Xepapadaki
- Allergy Unit; 2nd Pediatric Clinic; University of Athens; Athens Greece
| | - A. Fiocchi
- Division of Allergy; Pediatric Hospital Bambino Gesù; Rome Italy
| | - L. Grabenhenrich
- Institute of Social Medicine, Epidemiology and Health Economics; Charité - Universitätsmedizin Berlin; Berlin Germany
| | - G. Roberts
- Clinical and Experimental Sciences Academic Units; Faculty of Medicine; University of Southampton; Southampton UK
| | - K. E. C. Grimshaw
- Clinical and Experimental Sciences Academic Units; Faculty of Medicine; University of Southampton; Southampton UK
| | - A. Fiandor
- Department of Allergy; Hospital La Paz Institute for Health Research; Madrid Spain
| | - J. I. Larco
- Department of Allergy; Hospital La Paz Institute for Health Research; Madrid Spain
| | - S. Sigurdardottir
- Department of Immunology; Landspitali - The National University Hospital of Iceland; Reykjavik Iceland
| | - M. Clausen
- Children's Hospital; Landspitali - The National University Hospital of Iceland; Reykjavik Iceland
| | - N. G. Papadopoulos
- Allergy Unit; 2nd Pediatric Clinic; University of Athens; Athens Greece
- Centre for Paediatrics and Child Health; Institute of Human Development; University of Manchester; Manchester UK
| | - L. Dahdah
- Division of Allergy; Pediatric Hospital Bambino Gesù; Rome Italy
| | - A. Mackie
- Institute of Food Research; Norwich Research Park; Colney Norwich UK
| | - A. B. Sprikkelman
- Department of Pediatric Respiratory Medicine and Allergy; Emma Children's Hospital; Academic Medical Center; Amsterdam The Netherlands
| | - A. A. Schoemaker
- Department of Pediatric Respiratory Medicine and Allergy; Emma Children's Hospital; Academic Medical Center; Amsterdam The Netherlands
| | - R. Dubakiene
- Vilnius University Faculty of Medicine; Vilnius Lithuania
| | - I. Butiene
- Faculty of Health Sciences; Klaipeda University; Klaipeda Lithuania
| | - M. L. Kowalski
- Department of Immunology, Rheumatology and Allergy; Medical University of Lodz; Lodz Poland
| | - K. Zeman
- Department of Pediatrics, Immunology and Nephrology; Polish Mother's Health Centre Research Institute Łódź; Lodz Poland
| | - S. Gavrili
- Neonatal Intensive Care Unit; Alexandra University Hospital; Athens Greece
| | - T. Keil
- Institute of Social Medicine, Epidemiology and Health Economics; Charité - Universitätsmedizin Berlin; Berlin Germany
- Institute for Clinical Epidemiology and Biometry; University of Würzburg; Würzburg Germany
| | - K. Beyer
- Department of Paediatric Pneumonology and Immunology; Charité - Universitätsmedizin Berlin; Berlin Germany
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11
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Sigurdardottir S, Andelic N, Roe C, Schanke AK. Identifying longitudinal trajectories of emotional distress symptoms 5 years after traumatic brain injury. Brain Inj 2014; 28:1542-50. [DOI: 10.3109/02699052.2014.934285] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Affiliation(s)
- S. Sigurdardottir
- Department of Research, Sunnaas Rehabilitation Hospital
NesoddtangenNorway
- Institute of Health and Society, Research Centre for Habilitation and Rehabilitation Models and Services (CHARM), Faculty of Medicine, University of Oslo
OsloNorway
- Department of Physical Medicine and Rehabilitation, Oslo University Hospital
Ulleval, OsloNorway
| | - N. Andelic
- Institute of Health and Society, Research Centre for Habilitation and Rehabilitation Models and Services (CHARM), Faculty of Medicine, University of Oslo
OsloNorway
- Department of Physical Medicine and Rehabilitation, Oslo University Hospital
Ulleval, OsloNorway
| | - C. Roe
- Department of Physical Medicine and Rehabilitation, Oslo University Hospital
Ulleval, OsloNorway
- Institute of Clinical Medicine, Faculty of Medicine, University of Oslo
OsloNorway
| | - A. K. Schanke
- Department of Research, Sunnaas Rehabilitation Hospital
NesoddtangenNorway
- Department of Psychology, Faculty of Social Sciences, University of Oslo
OsloNorway
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12
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Olafsdottir K, Sigurdardottir S, Gislason T, Johannesdottir O, Hilmarsson O, Arnardottir E. Difference between automatic and manual analysis of respiratory events in sleep studies. Sleep Med 2013. [DOI: 10.1016/j.sleep.2013.11.534] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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13
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Forslund MV, Roe C, Sigurdardottir S, Andelic N. Predicting health-related quality of life 2 years after moderate-to-severe traumatic brain injury. Acta Neurol Scand 2013; 128:220-7. [PMID: 23621298 DOI: 10.1111/ane.12130] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/05/2013] [Indexed: 11/30/2022]
Abstract
AIMS To describe health-related quality of life (HRQL) 2 years after moderate-to-severe traumatic brain injury (TBI) and to assess predictors of HRQL. MATERIALS AND METHODS A prospective cohort study of 91 patients, aged 16-55 years, admitted with moderate-to-severe TBI to a trauma referral centre between 2005 and 2007, with follow-up at 1 and 2 years. Mean age was 31.1 (SD = 11.3) years, and 77% were men. Injury severity was evaluated by the Glasgow Coma Scale (GCS), head CT scan (using a modified Marshall Classification), Injury Severity Score (ISS) and post-traumatic amnesia (PTA). The Functional Independence Measure (FIM), Community Integration Questionnaire (CIQ), Beck Depression Inventory (BDI) and Medical Outcomes 36-item Short Form Health Survey (SF-36) were administered at follow-up visits. The main outcome measures were the Physical Component Summary (PCS) and Mental Component Summary (MCS) of the SF-36. RESULTS HRQL appears to be relatively stable between 1 and 2 years after injury. In the multivariate linear regression, younger age (β = -0.20, P = 0.032), more severe TBI (β = 0.28, P = 0.016), more severe overall trauma (β = 0.22, P = 0.026), higher levels of community integration (β = 0.36, P = 0.019) and higher positive change in PCS scores from 1 to 2 years (β = 0.41, P < 0.001) predicted better self-reported physical health 2 years post-TBI. Lower scores for depression (β = -0.70, P < 0.001) and a higher positive change in MCS scores (β = 0.62, P < 0.001) predicted better self-reported mental health. CONCLUSIONS Future interventions should focus on aspects related to HRQL that are more easily modified, such as physical functioning, home and social integration, productivity, and mental and emotional status.
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Affiliation(s)
| | | | | | - N. Andelic
- Department of Physical Medicine and Rehabilitation; Oslo University Hospital; Oslo; Norway
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14
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Forslund M, Roe C, Arango-Lasprilla J, Sigurdardottir S, Andelic N. Impact of personal and environmental factors on employment outcome two years after moderate-to-severe traumatic brain injury. J Rehabil Med 2013; 45:801-7. [DOI: 10.2340/16501977-1168] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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15
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Sigurdardottir S, Andelic N, Roe C, Schanke A. Depressive symptoms and psychological distress during the first five years after traumatic brain injury: Relationship with psychosocial stressors, fatigue and pain. J Rehabil Med 2013; 45:808-14. [DOI: 10.2340/16501977-1156] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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16
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McBride D, Keil T, Grabenhenrich L, Dubakiene R, Drasutiene G, Fiocchi A, Dahdah L, Sprikkelman AB, Schoemaker AA, Roberts G, Grimshaw K, Kowalski ML, Stanczyk-Przyluska A, Sigurdardottir S, Clausen M, Papadopoulos NG, Mitsias D, Rosenfeld L, Reche M, Pascual C, Reich A, Hourihane J, Wahn U, Mills ENC, Mackie A, Beyer K. The EuroPrevall birth cohort study on food allergy: baseline characteristics of 12,000 newborns and their families from nine European countries. Pediatr Allergy Immunol 2012; 23:230-9. [PMID: 22192443 DOI: 10.1111/j.1399-3038.2011.01254.x] [Citation(s) in RCA: 106] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
It is unclear why some children develop food allergy. The EuroPrevall birth cohort was established to examine regional differences in the prevalence and risk factors of food allergy in European children using gold-standard diagnostic criteria. The aim of this report was to describe pre-, post-natal and environmental characteristics among the participating countries. In nine countries across four major European climatic regions, mothers and their newborns were enrolled from October 2005 through February 2010. Using standardized questionnaires, we assessed allergic diseases and self-reported food hypersensitivity of parents and siblings, nutrition during pregnancy, nutritional supplements, medications, mode of delivery, socio-demographic data and home environmental exposures. A total of 12,049 babies and their families were recruited. Self-reported adverse reactions to food ever were considerably more common in mothers from Germany (30%), Iceland, United Kingdom, and the Netherlands (all 20-22%) compared with those from Italy (11%), Lithuania, Greece, Poland, and Spain (all 5-8%). Prevalence estimates of parental asthma, allergic rhinitis and eczema were highest in north-west (Iceland, UK), followed by west (Germany, the Netherlands), south (Greece, Italy, Spain) and lowest in central and east Europe (Poland, Lithuania). Over 17% of Spanish and Greek children were exposed to tobacco smoke in utero compared with only 8-11% in other countries. Caesarean section rate was highest in Greece (44%) and lowest in Spain (<3%). We found country-specific differences in antibiotic use, pet ownership, type of flooring and baby's mattress. In the EuroPrevall birth cohort study, the largest study using gold-standard diagnostic criteria for food allergy in children worldwide, we found considerable country-specific baseline differences regarding a wide range of factors that are hypothesized to play a role in the development of food allergy including allergic family history, obstetrical practices, pre- and post-natal environmental exposures.
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Affiliation(s)
- D McBride
- Institute of Social Medicine, Epidemiology and Health Economics, Charité University Medical Center, Berlin, Germany
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17
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Andelic N, Anke A, Skandsen T, Sigurdardottir S, Sandhaug M, Ader T, Roe C. Incidence of Hospital-Admitted Severe Traumatic Brain Injury and In-Hospital Fatality in Norway: A National Cohort Study. Neuroepidemiology 2012; 38:259-67. [DOI: 10.1159/000338032] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2011] [Accepted: 03/11/2012] [Indexed: 11/19/2022] Open
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18
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Turesson I, Bernefors R, Book M, Flogegård M, Hermansson I, Johansson KA, Lindh A, Sigurdardottir S, Thunberg U, Nyman J. Normal tissue response to low doses of radiotherapy assessed by molecular markers--a study of skin in patients treated for prostate cancer. Acta Oncol 2002; 40:941-51. [PMID: 11845959 DOI: 10.1080/02841860152708224] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
The aim of this study was to evaluate normal tissue response by molecular markers to multifraction low doses of ionizing radiation, with the focus on changes in repopulation, estimated using Ki-67 as the proliferation marker, and on expressions of the p53 and p21 proteins, identified as key proteins in the DNA damage checkpoint. Repeated skin biopsies were taken from patients treated for prostate cancer with radiotherapy. The expressions of Ki-67, p53 and p21 of the keratinocytes in the basal cell layer of the epidermis were quantified immunohistochemically. The dose to the basal layer was 1.1 Gy per fraction, given five times per week for seven weeks. The indices of the three markers were determined over the whole period. A significant suppression of the Ki-67 index was observed during the first weeks, followed by a significant gradual increase in the Ki-67 index over the last weeks. The p53 and p21 protein levels were almost zero in the unirradiated skin. Upon irradiation, both the p53 and p21 index increased in a pattern very congruent to the Ki-67 index. In conclusion, daily fractions of about 1 Gy to the skin resulted in, for the keratinocytes in the basal layer, a cell growth arrest for a couple of weeks and a subsequent acceleration in repopulation during the following weeks of irradiation. The present findings also provided novel insights into the role of the p53/p21 pathway in the response of a normal epithelium to ionizing radiation as it is applied in radiotherapy.
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Affiliation(s)
- I Turesson
- Department of Oncology, Radiology and Clinical Immunology, Uppsala University Hospital, Sweden
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Abstract
Schimke immunoosseous dysplasia (SID) is a rare, pleiotropic disorder compromising spondyloepiphyseal dysplasia, nephrotic syndrome, defective T-cell-mediated immunity, and vascular changes which can lead to cerebral infarcts. The cause is unknown but an autosomal recessive inheritance pattern has been suggested. Understanding of the clinical phenotype is evolving; however, the neurologic spectrum is not well known. We report on a 17-year-old woman who presented with behavior changes, developmental regression, and partial complex seizures in early childhood. Computed tomographic scan of the brain was normal at that time. Short stature and cognitive deficits became evident several months later. At 4 1/2 years, she developed nephrotic syndrome and later malignant hypertension. Recent magnetic resonance imaging of the brain showed focal encephalomalacia in the parietal regions and a magnetic resonance angiography documented narrowing of the middle cerebral arteries. A skeletal survey showed evidence of spondyloepiphyseal dysplasia. We have not been able to identify an immune defect. To our knowledge this is the first reported patient with SID, profound mental retardation, and a seizure disorder. This case supports the theory that an intrinsic vascular defect may be more important in the pathogenesis of SID than a T-cell-mediated immune deficit.
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Affiliation(s)
- S Sigurdardottir
- Kennedy Krieger Institute, Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205-1888, USA
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Sigurdardottir S, Goodman BK, Rutberg J, Thomas GH, Jabs EW, Geraghty MT. Clinical, cytogenetic, and fluorescence in situ hybridization findings in two cases of "complete ring" syndrome. Am J Med Genet 1999; 87:384-90. [PMID: 10594875 DOI: 10.1002/(sici)1096-8628(19991222)87:5<384::aid-ajmg3>3.0.co;2-r] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The term "ring syndrome" was proposed to describe a phenotype of growth failure without major malformations due to a ring autosome. The growth failure is thought to be caused by instability of the ring chromosome leading to aneusomy and cell death. Most previous studies of ring chromosomes were based on standard cytogenetic banding techniques and were limited to microscopically detectable deletions in the ring chromosomes. We report on two patients with complete ring (4) and ring (9) chromosomes, respectively. The first was a 15-month-old girl and the second was a 16-month-old boy. They both presented with severe, symmetrical growth failure and normal psychomotor development in the absence of malformations. Their parents had a normal phenotype. The first case had a whorled pattern of hyperpigmentation and hypopigmentation on part of the face and chest, and the second case had a patchy hyperpigmented rash on the trunk. Peripheral blood karyotype of the first patient was 46,XX, r(4)(p16.3q35.2) and of the second 45,XY,-9/46,XY,r(9)(p24q34.3). G-band analysis suggested no loss of material in the ring chromosomes. These findings were confirmed by fluorescence in situ hybridization (FISH) analysis using chromosome-specific subtelomeric probes. The common human telomeric sequences were intact in the first patient but absent in the second patient. The cytogenetic and FISH data in our two cases provide further evidence for the existence of a "complete ring" phenotype independent of the autosome involved. Pigmentary skin changes are a useful clinical sign of mosaicism caused by the ring instability.
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Affiliation(s)
- S Sigurdardottir
- Kennedy Krieger Institute, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21287-4922, USA
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21
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Gunnarsson T, Sigurdardottir S, Hoffmann P, Skarphedinsson JO. The effects of selective opioid antagonists on somatosensory evoked potentials during relative cerebral ischemia in rats. Life Sci 1994; 55:1365-74. [PMID: 7934643 DOI: 10.1016/0024-3205(94)00769-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Hemorrhagic hypotension in spontaneously hypertensive rats induces attenuation of somatosensory evoked potentials. In this model of relatively mild cerebral ischemia, our previous studies have shown that naloxone stereospecifically enhances the evoked potentials, without changes in cortical blood flow. The high dose of naloxone needed to enhance the evoked potentials suggests that the attenuation is mediated by low affinity opioid receptors (delta or kappa). In the present study, we used this model to study the effects of naloxone-methobromide (5 mg kg-1, a quaternary derivative of naloxone with selective peripheral action when injected intravenously), MR 2266 (1 mg kg-1, a kappa receptor antagonist), and naloxone (5 mg kg-1) as well as saline injection (as control) in four different groups of rats. Following injection, we examined the changes in somatosensory evoked potentials, cortical blood flow and heart rate for 15 min while mean arterial pressure was held constant by a pressure-regulating reservoir. Only naloxone changed the somatosensory evoked potential amplitude significantly compared with the saline group in which no effect was seen. However, there was a tendency for a delayed effect of naloxone-methobromide on the evoked potentials, possibly indicating that the substance slowly passes the blood-brain barrier. Naloxone and MR 2266 caused a transient decrease in heart rate, while following naloxone-methobromide injection there was a slight increase in heart rate. Our results thus indicate that the beneficial effects of naloxone on somatosensory evoked potentials during relative cerebral ischemia may be centrally mediated by a non-kappa mechanism.
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Affiliation(s)
- T Gunnarsson
- Department of Physiology, University of Iceland, Reykjavik
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22
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Andersson L, Lundén A, Sigurdardottir S, Davies CJ, Rask L. Linkage relationships in the bovine MHC region. High recombination frequency between class II subregions. Immunogenetics 1988; 27:273-80. [PMID: 2894354 DOI: 10.1007/bf00376122] [Citation(s) in RCA: 92] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Class II genes of the bovine major histocompatibility complex (MHC) have been investigated by Southern blot analysis using human DNA probes. Previous studies revealed the presence of bovine DO beta, DQ alpha, DQ beta, DR alpha, and DR beta genes, and restriction fragment length polymorphisms for each of these genes were documented. In the present study, the presence of three additional class II genes, designated DZ alpha, DY alpha, and DY beta, are reported. DZ alpha was assumed to correspond to the human DZ alpha gene while the other two were designated DY because their relationship to human class II genes could not be firmly established. The linkage relationships among bovine class II genes and two additional loci, TCP1B and C4, were investigated by family segregation analysis and analysis of linkage disequilibrium. The results clearly indicated that all these loci belong to the same linkage group. This linkage group is divided into two subregions separated by a fairly high recombination frequency. One region includes the C4, DQ alpha, DQ beta, DR alpha, and DR beta loci and the other one is composed of the DO beta, DY alpha, DY beta, and TCP1B loci. No recombinant was observed within any of these subregions and there was a strong or fairly strong linkage disequilibrium between loci within groups. In contrast, as many as five recombinants among three different families were detected in the interval between these subregions giving a recombination frequency estimate of 0.17 +/- 0.07. The fairly high recombination frequency observed between class II genes in cattle is strikingly different from the corresponding recombination estimates in man and mouse. The finding implies either a much larger molecular distance between some of the bovine class II genes or alternatively the presence of a recombinational "hot spot" in the bovine class II region.
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Affiliation(s)
- L Andersson
- Department of Animal Breeding and Genetics, Swedish University of Agricultural Sciences, Uppsala
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