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Öhman, Lena
Publications (10 of 16) Show all publications
Wilsson, A., Lind, S., Öhman, L., Nilsdotter-Augustinsson, Å. & Lundqvist-Setterud, H. (2008). Apoptotic neutrophils containing Staphylococcus epidermidis stimulate macrophages to release the proinflammatory cytokines tumor necrosis factor-a and interleukin-6. FEMS Immunology and Medical Microbiology, 53(1), 126-135
Open this publication in new window or tab >>Apoptotic neutrophils containing Staphylococcus epidermidis stimulate macrophages to release the proinflammatory cytokines tumor necrosis factor-a and interleukin-6
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2008 (English)In: FEMS Immunology and Medical Microbiology, ISSN 0928-8244, E-ISSN 1574-695X, Vol. 53, no 1, p. 126-135Article in journal (Refereed) Published
Abstract [en]

Staphylococcus epidermidis infections are usually nosocomial and involve colonization of biomaterials. The immune defense system cannot efficiently control the bacteria during these infections, which often results in protracted chronic inflammation, in which a key event is disturbed removal of neutrophils by tissue macrophages. While ingesting uninfected apoptotic neutrophils, macrophages release anti-inflammatory cytokines that lead to resolution of inflammation. In clinical studies, we have previously found elevated levels of the proinflammatory cytokines tumor necrosis factor-alpha (TNF-a) and interleukin-6 in synovial fluid from prostheses infected with coagulase negative staphylococci. We show that macrophages phagocytosing apoptotic neutrophils containing S. epidermidis released TNF-a and interleukin-6, whereas macrophages phagocytosing spontaneously apoptotic neutrophils did not. This difference was not due to dissimilar phagocytic capacities, because macrophages ingested both types of neutrophils to the same extent. The activation was induced mainly by the apoptotic neutrophils themselves, not by the few remaining extracellular bacteria. Macrophages were not activated by apoptotic neutrophils that contained paraformaldehyde-killed S. epidermidis. Proinflammatory reactions induced by clearance of apoptotic neutrophils containing S. epidermidis might represent an important mechanism to combat the infective agent. This activation of macrophages may contribute to the development of chronic inflammation instead of inflammation resolution. © 2008 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

Keywords
Chronic inflammation, Macrophage, Neutrophil, Phagocytosis, Staphylococcus epidermidis infection, TNF-a
National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:liu:diva-45989 (URN)10.1111/j.1574-695X.2008.00412.x (DOI)
Available from: 2009-10-11 Created: 2009-10-11 Last updated: 2017-12-13
Nilsdotter-Augustinsson, Å., Koskela, A., Öhman, L. & Söderquist, B. (2007). Characterization of coagulase-negative staphylococci isolated from patients with infected hip prostheses: use of phenotypic and genotypic analyses, including tests for the presence of the ica operon. European Journal of Clinical Microbiology and Infectious Diseases, 26(4), 255-265
Open this publication in new window or tab >>Characterization of coagulase-negative staphylococci isolated from patients with infected hip prostheses: use of phenotypic and genotypic analyses, including tests for the presence of the ica operon
2007 (English)In: European Journal of Clinical Microbiology and Infectious Diseases, ISSN 0934-9723, E-ISSN 1435-4373, Vol. 26, no 4, p. 255-265Article in journal (Refereed) Published
Abstract [en]

The aim of this study was to investigate phenotypic and/or genotypic heterogeneity in coagulase-negative staphylococci (CoNS) obtained from multiple tissue samples taken perioperatively during exchange surgery from each of 19 patients with clinically and/or microbiologically proven hip prosthesis infections. CoNS are important pathogens in prosthetic hip joint infections. Several virulence factors have been suggested for CoNS, such as phenotypic variation, yet the pathogenic processes that are involved remain unclear. The PhenePlate system (PhPlate AB, Stockholm Sweden) was used for phenotyping and pulsed-field gel electrophoresis for genotyping of polymorphisms in isolates of CoNS. Furthermore, polymerase chain reaction was used to determine the presence of the icaADB gene complex in the isolates. Some patients were infected with CoNS and other species, some were infected with multiple CoNS species, although infections with Staphylococcus epidermidis alone were most common, and some were infected with different S. epidermidis clones. Phenotypic variation was found among isolates both from the same tissue sample and from different samples from the same patient, and in some cases such variation represented the presence of different clones. One-third of the patients infected with S. epidermidis carried the icaADB genes. CoNS isolates showing phenotypic and/or genotypic heterogeneity were identified in tissue samples from half of the patients. The presence of the intercellular adhesion (ica) operon does not seem to be a prerequisite for establishing infection with CoNS.

National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:liu:diva-81976 (URN)10.1007/s10096-007-0281-9 (DOI)
Note

On the day of the defence day the status of this article was

Manuscript

Available from: 2012-09-27 Created: 2012-09-27 Last updated: 2017-12-07Bibliographically approved
Nilsdotter-Augustinsson, Å., Briheim, G., Herder, A., Ljunghusen, O., Wahlström, O. & Öhman, L. (2007). Inflammatory response in 85 patients with loosened hip prostheses: A prospective study comparing inflammatory markers in patients with aseptic and septic prosthetic loosening. Acta Orthopaedica, 78(5), 629-639
Open this publication in new window or tab >>Inflammatory response in 85 patients with loosened hip prostheses: A prospective study comparing inflammatory markers in patients with aseptic and septic prosthetic loosening
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2007 (English)In: Acta Orthopaedica, ISSN 1745-3674, E-ISSN 1745-3682, Vol. 78, no 5, p. 629-639Article in journal (Refereed) Published
Abstract [en]

Over the past decades, prosthetic hip joints have improved the quality oflife for many patients. The most common complications are aseptic biornechanical failures and prosthetic joint infections. For prosthetic hip joints, delayed low-grade infections are seen most often and they are also most difficult to distinguish from aseptic mechanical failures. A prospective study was conducted to campare inilammatory markers in patients diagnosed with aseptic or septic prosthetic loosenffig. The diagnostic criteria were based on the decisions of experienced orthoperlic surgeons and microbiological analys is of periprosthetic tissue samplestaken perioperatively. Coagulase-negative staphylococci were the most common pathogens in the infected patients. Pre- or perioperative results for C-reactive protein and erytlu-ocyte sedimentation rate were valuable tools for diagnosing most, hut not all, low virulence infections. White blood cell count in synavial fluid was an important marker of infection, which was not the case for lactate. Levels of the cytokines turnor necrosis factor-α, interleukin-1 ß. and interleukin-6 in synavial fluid were significantly higher in the infected group. Patterus of inilammatory cell infiltration in periprosthetic tissue differed significantly between the groups, and infiltration of polymorphonuclear cells proved to be the best marker of distinguish between septic and aseptic loosenffig. Treatment and outcome are described for the infected patients.

National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:liu:diva-81959 (URN)10.1080/17453670710014329 (DOI)
Available from: 2012-09-26 Created: 2012-09-26 Last updated: 2017-12-07Bibliographically approved
Hammar, M., Bergdahl, B. & Öhman, L. (2006). Celebrating the Past by Expanding the Future: The Faculty of Health Science, Linköping University 1986–2006. Linköping: Linköping University Electronic Press
Open this publication in new window or tab >>Celebrating the Past by Expanding the Future: The Faculty of Health Science, Linköping University 1986–2006
2006 (English)Report (Other academic)
Abstract [en]

During the fall of 2006, the Faculty of Health Sciences (FHS) celebrates its 20th birthday. Linköping has a long tradition of health education; our nursing programme started already in 1895 and occupational therapy began in 1965. From the late 1960’s, medical students from Uppsala spent their last seven semesters in Linköping, mainly for clinical studies. After some years, academic and teachers from the young faculty, together with the county council, realized the enormous potential benefits of a complete undergraduate medical programme at Linköping University. Inspired by apparent innovations from McMaster University in Canada, Maastricht in Holland, Ben Gurion in Israel and Tromsø in Norway, these ideas and ideals were gradually turned into reality. In a complicated process, concerning the life or death of the medical faculty, a close co-operation between the University and the County Council of Östergötland was extremely fruitful. A proposal regarding a complete medical programme, and study periods integrated between the other health education programmes, was forwarded to the Swedish government in December 1982 and approved in 1984.

The new FHS at Linköping University was launched in 1986, and by the end of August the first students began their studies. Already at the start, FHS included several programmes for health professionals: nursing, occupational therapy, physiotherapy, medicine, social welfare and laboratory technology. Speech and language pathology was added in 2003 and the education curriculum for laboratory technicians was developed into a master’s programme in medical biology. A number of important concepts were included in the new programmes. Problem based learning (PBL) was chosen as the fundamental basis for organising studies; using small tutorial groups with supervisors as “coaches” and real patient histories as triggers for learning. Since 2001, realistic cases/scenarios are made available on the Intranet.

PBL is highly appreciated by the majority of students and teachers. This method of learning focused in contexts, according to pedagogic research, leads to a higher retention of knowledge than in traditional teacher-centered approaches toward learning. Important PBL spin-off effects are in educating students to cooperate in groups, to communicate and argue, to listen to other students’ opinions, to evaluate their own efforts and to identify learning needs. Furthermore, the method implies that students’ learn to independently find and evaluate scientific information, thereby realizing that the truth is somewhat “relative,” since what they find may differ depending on the sources used. Perhaps the most important characteristic of PBL is that it moves the main responsibility for obtaining goals and new knowledge from the teacher to the student.

Other important elements of the various curricula at the FHS are vertical and horizontal integration. In vertical integration, e.g. between clinical and basic science, different sections are interwoven with clear progressive shifts over phases and semesters. This has shown to stimulate profound rather than superficial learning, and probably stimulates better understanding. Horizontal integration focuses on the simultaneous learning of several subjects needed to understand and explain the scenarios used.

In PBL, teachers are expected to cooperate over departmental borders, a process that often produces positive spin-off effects extending further to research. They take on many different roles as e.g. planners, semester coordinators, tutors, lecturers and clinical supervisors. As such, newcomers may encounter certain frustration. Continuous staff development is critical to assure pedagogical selection and excellence, and thereby the quality of the programmes.

In PBL, teachers are expected to cooperate over departmental borders, a process that often produces positive spin-off effects extending further to research. They take on many different roles as e.g. planners, semester coordinators, tutors, lecturers and clinical supervisors. As such, newcomers may encounter certain frustration. Continuous staff development is critical to assure pedagogical selection and excellence, and thereby the quality of the programmes.

The aim to be a medical faculty with a standing among the most progressive worldwide implies continuous evaluation and development. Our mission is to foster the very best in health care; health care extending consideration toward educating competent professionals and conducting quality research with a focus on societal needs and welfare. To fulfil this mission, we need to advance teaching models based on evidence, and continuously improve and develop our educational methods. This process requires cooperation between departments, teachers and students within the university and indeed, throughout the world. Such contacts and collaborations are as important in education as they are in research, and extend an endless source of inspiration. Communication between the different undergraduate programmes at FHS has been extremely fruitful and should further be stimulated. At the faculty level, it is important to provide teachers with credit for efforts and development toward education. To keep integration and innovation at a high level, it is very important to balance the decision power and the distribution of money between departments and programmes.

The aim of this book is to provide a general overview, in glimpses, of some of the important developments in FHS education; to describe new ideas in progress or those already turned to reality and also, to extend some consideration of publications regarding our educational innovations. We hope these examples provide the essence of inspiration for future work, contributing to improved education and better health for all.

Place, publisher, year, edition, pages
Linköping: Linköping University Electronic Press, 2006. p. 106
Series
Medical Faculty report, ISSN 1652-3598, E-ISSN 1652-3601 ; 3
National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:liu:diva-62223 (URN)91-85643-07-6 (ISBN)
Note

Produced by the Department of External Relations, Linköping university Coordinator: Åke Hjelm. Editorial translation: Bohdan Sklepkovych. Design: Peter Modin. Photographers: Göran Billeson. Ida Lagstam, Jan Christer Persson

Available from: 2007-02-05 Created: 2010-11-23 Last updated: 2018-01-25Bibliographically approved
Nilsdotter-Augustinsson, Å., Claesson, C., Lindgren, P.-E., Lundqvist Gustafsson, H. & Öhman, L. (2005). Adherence of Staphylococcus epidermidis to extracellular matrix proteins and effects of fibrinogen-bound bacteria on oxidase activity and apoptosis in neutrophils. Acta Pathologica, Microbiologica et Immunologica Scandinavica (APMIS), 113(5), 361-373
Open this publication in new window or tab >>Adherence of Staphylococcus epidermidis to extracellular matrix proteins and effects of fibrinogen-bound bacteria on oxidase activity and apoptosis in neutrophils
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2005 (English)In: Acta Pathologica, Microbiologica et Immunologica Scandinavica (APMIS), ISSN 0903-4641, E-ISSN 1600-0463, Vol. 113, no 5, p. 361-373Article in journal (Refereed) Published
Abstract [en]

Staphylococcus epidermidis often causes foreign-body infections such as those associated with hip prostheses, but the underlying pathogenic mechanisms are not fully understood. We performed spectrophotometry to study the ability of S. epidermidis to bind to immobilised fibrinogen, fibronectin, vitronectin, and collagen. The strains were isolated from infected hip prostheses or from normal flora and the well-known protein-binding strain Staphylococcus aureus Cowan was used as positive control. We also analysed the interaction between neutrophils and a fibrinogen-bound prosthesis-derived strain of S. epidermidisby measuring chemiluminescence to determine the neutrophil oxidative response and binding of annexin V to indicate neutrophil apoptosis. We found that binding of S. epidermidis to extracellular matrix proteins varied under different growth conditions, and that prosthesis isolates adhered better to vitronectin than did strains from normal flora. The oxidative response caused by fibrinogen-bound S. epidermidis was not above the background level, which was in marked contrast to the distinct response induced by fibrinogen-associated S. aureus Cowan. Furthermore, fibrinogen-adhering S. epidermidis retarded neutrophil apoptosis. We conclude that surface-bound S. epidermidis induces only a weak inflammatory response, which in combination with the ability of the adherent bacteria to retard neutrophil apoptosis may contribute to low-grade inflammation and loosening of prostheses.

National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:liu:diva-28719 (URN)10.1111/j.1600-0463.2005.apm_113508.x (DOI)13888 (Local ID)13888 (Archive number)13888 (OAI)
Available from: 2009-10-09 Created: 2009-10-09 Last updated: 2017-12-13Bibliographically approved
Christensson, B., Dahlin, L.-G., Hogevik, H., Tegnell, A. & Öhman, L. (2004). Infektioner hos reservdelsmänniskan - en epidemiologisk och klinisk översikt.. Läkartidningen, 101(11), 982-988
Open this publication in new window or tab >>Infektioner hos reservdelsmänniskan - en epidemiologisk och klinisk översikt.
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2004 (English)In: Läkartidningen, ISSN 0023-7205, E-ISSN 1652-7518, Vol. 101, no 11, p. 982-988Article in journal (Other academic) Published
Keywords
Reservdelsmänniskan
National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:liu:diva-22009 (URN)1022 (Local ID)1022 (Archive number)1022 (OAI)
Available from: 2009-10-07 Created: 2009-10-07 Last updated: 2017-12-13
Nilsdotter-Augustinsson, Å., Wilsson, Å., Larsson, J., Stendahl, O., Öhman, L. & Lundqvist Gustafsson, H. (2004). Staphylococcus aureus, but not Staphylococcus epidermidis, modulates the oxidative response and induces apoptosis in human neutrophils. Acta Pathologica, Microbiologica et Immunologica Scandinavica (APMIS), 112(2), 109-118
Open this publication in new window or tab >>Staphylococcus aureus, but not Staphylococcus epidermidis, modulates the oxidative response and induces apoptosis in human neutrophils
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2004 (English)In: Acta Pathologica, Microbiologica et Immunologica Scandinavica (APMIS), ISSN 0903-4641, E-ISSN 1600-0463, Vol. 112, no 2, p. 109-118Article in journal (Refereed) Published
Abstract [en]

S. epidermidis is the most common isolate in foreign body infections. The aim of this study was to understand why S. epidermidis causes silent biomaterial infections. In view of the divergent inflammatory responses S. epidermidis and S. aureus cause in patients, we analyzed how they differ when interacting with human neutrophils. Neutrophils interacting with S. epidermidis strains isolated either from granulation tissue covering infected hip prostheses or from normal skin flora were tested by measuring the oxidative response as chemiluminescence and apoptosis as annexin V binding. Different S. aureus strains were tested in parallel. All S. epidermidis tested were unable to modulate the oxidative reaction in response to formyl-methionyl-leucyl-phenylalanine (fMLP) and did not provoke, but rather inhibited, apoptosis. In contrast, some S. aureus strains enhanced the oxidative reaction, and this priming capacity was linked to p38-mitogen-activated-protein-kinase (p38-MAPK) activation and induction of apoptosis. Our results may explain why S. epidermidis is a weak inducer of inflammation compared to S. aureus, and therefore responsible for the indolent and chronic course of S. epidermidis biomaterial infections.

National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:liu:diva-23732 (URN)10.1111/j.1600-0463.2004.apm1120205.x (DOI)3239 (Local ID)3239 (Archive number)3239 (OAI)
Available from: 2009-10-07 Created: 2009-10-07 Last updated: 2017-12-13Bibliographically approved
Nimeri, G., Majeed, M., Elwing, H., Öhman, L., Wetterö, J. & Bengtsson, T. (2003). Oxygen radical production in neutrophils interacting with platelets and surface-immobilized plasma proteins: role of tyrosine phosphorylation. Journal of Biomedical Materials Research, 67A(2), 439-447
Open this publication in new window or tab >>Oxygen radical production in neutrophils interacting with platelets and surface-immobilized plasma proteins: role of tyrosine phosphorylation
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2003 (English)In: Journal of Biomedical Materials Research, ISSN 0021-9304, E-ISSN 1097-4636, Vol. 67A, no 2, p. 439-447Article in journal (Refereed) Published
Abstract [en]

The interaction between neutrophil granulocytes and platelets is considered to play an important role in the inflammatory process induced by an implanted foreign material. However, the cellular mechanisms involved remain incompletely understood. We used a luminol-dependent chemiluminescence (CL) technique to analyze the generation of reactive oxygen species (ROS) in human neutrophils interacting with different plasma protein-coated surfaces in the presence or absence of unstimulated or stimulated platelets. The role of tyrosine phosphorylation in the regulation of NADPH oxidase activity was evaluated with quantitative fluorescence microscopy and the specific tyrosine kinase inhibitor genistein. We found that the ROS-production is 2 to 3 times higher in neutrophils on immunoglobulin G (IgG)coated surfaces than in cells interacting with albumin- or fibrinogen-coated surfaces. Incubation with superoxide dismutase and catalase revealed that about 45% of the ROS was released extracellularly on IgG surfaces whereas corresponding values were 90% and 85% in neutrophils interacting with albumin and fibrinogen, respectively. The presence of platelets markedly increased the extracellular generation of ROS, mainly in neutrophils. interacting with IgG- or fibrinogen-coated surfaces whereas the intracellular production was only modestly affected. Quantitative fluorescence microscopy of neutrophils stained with FITC-conjugated anti-phosphotyrosine antibodies showed a correlation between tyrosine phosphorylation, cell spreading, and ROS production. Platelets markedly amplified the anti-phosphotyrosine staining on both fibrinogen- and IgG-coated surfaces whereas the low level of tyrosine phosphorylation in neutrophils on albumin-coated surfaces was not further elevated by platelets. Furthermore, the tyrosine kinase inhibitor genistein inhibited both extra- and intracellular ROS production in neutrophils regardless of the presence of platelets. We demonstrate that plasma protein coating and the presence of platelets are crucial for the inflammatory response of adhering neutrophils and that the oxidative response correlates with the extent of tyrosine phosphorylation of proteins in focal contacts. (C) 2003 Wiley Periodicals, Inc.

Keywords
plasma protein, neutrophil, platelet, reactive oxygen species, tyrosine phosphorylation
National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:liu:diva-47746 (URN)10.1002/jbm.a.10081 (DOI)
Available from: 2009-10-11 Created: 2009-10-11 Last updated: 2017-12-13
Tegnell, A., Grabowska, K., Jacobsson, A., Andersson, M., Giesecke, J. & Öhman, L. (2003). Study of developed resistance due to antibiotic treatment of coagulase-negative staphylococci. Microbial Drug Resistance, 9(1), 1-6
Open this publication in new window or tab >>Study of developed resistance due to antibiotic treatment of coagulase-negative staphylococci
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2003 (English)In: Microbial Drug Resistance, ISSN 1076-6294, E-ISSN 1931-8448, Vol. 9, no 1, p. 1-6Article in journal (Refereed) Published
Abstract [en]

Coagulase-negative Staphylococci (CoNS) are a major cause of postoperative infections. These infections are often associated with foreign material implants and/or a compromised immune system in the patient. Multiresistant strains are increasingly common in the hospital environment and there is concern that the infections will become difficult or impossible to treat. This report is based on a study of 75 patients, with postoperative infections caused by CoNS after thoracic surgery. All patients were treated with surgical revision and antibiotic therapy. One or more bacterial cultures were made in each case, and the resistance pattern of the CoNS found was determined. The goal of the study was to evaluate possible relationships between antibiotic therapy and the appearance of resistance to antibiotics in CoNS found. To describe this relationship, three models were constructed and analyzed by multiple logistic regression. The results indicate an increased resistance to β-lactam antibiotics and clindamycin after the use of cephalosporins. Also, the use of vancomycin or vancomycin combination with rifampicin or fusidic acid increases the risk for development of resistance to β-lactam antibiotics, ciprofloxacin, fusidic acid, clindamycin, netilmycin, and rifampicin. The hypothesis that a combination of antibiotics will curtail the development of resistance was not supported in this study.

National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:liu:diva-48659 (URN)10.1089/107662903764736283 (DOI)
Available from: 2009-10-11 Created: 2009-10-11 Last updated: 2017-12-12Bibliographically approved
Tegnell, A., Saeedi, B., Isaksson, B., Granfeldt, H. & Öhman, L. (2002). A clone of coagulase-negative staphylococci among patients with post-cardiac surgery infections. Journal of Hospital Infection, 52(1), 37-42
Open this publication in new window or tab >>A clone of coagulase-negative staphylococci among patients with post-cardiac surgery infections
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2002 (English)In: Journal of Hospital Infection, ISSN 0195-6701, E-ISSN 1532-2939, Vol. 52, no 1, p. 37-42Article in journal (Refereed) Published
Abstract [en]

Coagulase-negative staphylococci (CoNS) are important causes of hospital-acquired infections such as infections after cardiac surgery. Efforts to reduce these infections are hampered by the lack of knowledge concerning the epidemiology of CoNS in this setting. Forty strains of CoNS collected during the surgical revision of 27 patients operated on between 1997 and 2000 were analysed. Strains were also collected from the ambient air in the operating suite. Their pulsed-field gel electrophoresis (PFGE) characteristics and antibiotic resistance were analysed. Using PFGE 19 of 40 strains from 15 of 27 patients were shown to belong to one clone, and strains from this clone were also isolated from the ambient air. This clone had caused infections throughout the period. Antibiotic resistance did not correlate with PFGE patterns. Using PFGE one clone could be identified that caused 56% of the CoNS infections during this period. A strain from this clone was also found in the air of the operating suite suggesting the origin of the CoNS causing infections was the hospital environment.

National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:liu:diva-26496 (URN)10.1053/jhin.2002.1267 (DOI)11052 (Local ID)11052 (Archive number)11052 (OAI)
Available from: 2009-10-08 Created: 2009-10-08 Last updated: 2017-12-13Bibliographically approved
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