80 results on '"Larsen JL"'
Search Results
2. Field testing of a vaccine against eel diseases caused by Vibrio vulnificus
- Author
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Fouz, B, primary, Esteve-Gassent, MD, additional, Barrera, R, additional, Larsen, JL, additional, Nielsen, ME, additional, and Amaro, C, additional
- Published
- 2001
- Full Text
- View/download PDF
3. Is Aeromonas hydrophila the dominant motile Aeromonas species that causes disease outbreaks in aquaculture production in the Zhejiang Province of China?
- Author
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Nielsen, ME, primary, Høi, L, additional, Schmidt, AS, additional, Qian, D, additional, Shimada, T, additional, Shen, JY, additional, and Larsen, JL, additional
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- 2001
- Full Text
- View/download PDF
4. Isolation of oxidase-negative Aeromonas salmonicida from diseased turbot Scophthalmus maximus
- Author
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Pedersen, K, primary, Kofod, H, additional, Dalsgaard, I, additional, and Larsen, JL, additional
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- 1994
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5. Ribotyping of Aeromonas salmonicida subsp. salmonicida
- Author
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Nielsen, B, primary, Olsen, JE, primary, and Larsen, JL, additional
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- 1994
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6. An indovirus-like agent associated with systemic infection in cultured turbot Scophlhalmus maximus fry in Denmark
- Author
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Bloch, B, primary and Larsen, JL, additional
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- 1993
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7. rRNA gene restriction patterns of Vibrio anguillarum serogroup O1
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Pedersen, K, primary and Larsen, JL, additional
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- 1993
- Full Text
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8. Plasmid profiling as an epidemiological marker within Aeromonas salmonicida
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Nielsen, 8, primary, Olsen, JE, additional, and Larsen, JL, additional
- Published
- 1993
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- View/download PDF
9. Characterization of Vibrio damsela strains isolated from turbot Scophthalmus maximus in Spain
- Author
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Fouz, B, primary, Larsen, JL, additional, Nielsen, B, additional, Barja, JL, additional, and Toranzo, AE, additional
- Published
- 1992
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10. Encephalomyelitis among turbot associated with a picornavirus-like agent
- Author
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Bloch, B, primary, Gravningen, K, additional, and Larsen, JL, additional
- Published
- 1991
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11. ' A new sense of my former self' - transforming the self through vocational rehabilitation for people with acquired brain injury.
- Author
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Kold P, Peoples H, Kristensen HK, and Maersk JL
- Subjects
- Humans, Male, Female, Adult, Middle Aged, Interviews as Topic, Qualitative Research, Self Concept, Occupational Therapy methods, Social Support, Rehabilitation, Vocational methods, Brain Injuries rehabilitation, Brain Injuries psychology, Return to Work psychology
- Abstract
Background: Acquired Brain injury (ABI) causes ripples throughout the occupational and social fabric. It enters people's lives at a significant personal cost, encroaching on people's sense of self. Vocational rehabilitation is a viable venue to regain control of their life and support them in forming a new sense of self. From an occupational perspective, little is known about how vocational rehabilitation can support people through transforming their sense of self., Aim: This study aims to explore how vocational rehabilitation may influence the relationship between sense of self and occupational engagement for persons with ABI. Material and Methods: Six persons with ABI were purposely sampled. Data were collected using semi-structured individual interviews and analysed using a hermeneutic approach., Results: The analysis resulted in three themes: a new sense of my former self, engaging in occupations as transformation, and the significance of support., Conclusions: Participating in vocational rehabilitation can enable persons with ABI to form a new sense of self. Engaging in occupations and professional support is significant in the transformation process., Significance: From an occupational perspective, the knowledge gained in this study stresses the essential role occupational engagement and proper targeted support have for people struggling to return to work after ABI.
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- 2024
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12. Zero Self-Harm app: a mobile phone application to reduce non-suicidal self-injury-study protocol for a randomized controlled trial.
- Author
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Guerrero E, Andreasson K, Larsen L, Buus N, Skovgaard Larsen JL, Krogh J, Thastum R, Lindberg L, Lindblad K, Erlangsen A, and Nordentoft M
- Subjects
- Humans, Suicidal Ideation, Surveys and Questionnaires, Randomized Controlled Trials as Topic, Multicenter Studies as Topic, Mobile Applications, Cell Phone, Mental Disorders
- Abstract
Background: Non-suicidal self-injury (NSSI) is a growing healthcare problem. Individuals with NSSI have an increased risk of suicidality. Due to stigma, they may self-injure in secret, which means they might not seek help until events have escalated to include suicidal ideation or a mental disorder. Interventions delivered via mobile phone applications (apps) have been linked to reductions in self-injury. This protocol outlines a trial, which examines whether the Zero Self-Harm intervention, consisting of an app for people with NSSI, can reduce the number of NSSI episodes, suicide ideation, and depressive symptoms., Methods: The trial will be conducted as a 6-month 2-arm, parallel-group, multicentre, pragmatic, randomized clinical superiority trial. The intervention group will receive the app and instructions on how to use it, while the control group will be allocated to a waitlist and allowed to download the app after 6 months. After inclusion, participants will be asked to complete questionnaires at baseline, 3 months, and 6 months. The primary outcome is the number of NSSI episodes during the preceding month, as measured at the 6 months follow-up with the Deliberate Self-Harm Inventory. A total of 280 participants, 140 in each arm, will be included., Discussion: This trial will assess the effectiveness of the Zero Self-Harm intervention to reduce the number of NSSI episodes. If effective, the app will have the potential to support a large group of people with NSSI. Considering the stigma related to NSSI, the fact that the app may be used in private and anonymously might make it an appealing and acceptable option for support. The app was developed in collaboration with people with lived experiences related to current and/or previous NSSI. As a result of this, the app focuses on minimizing harm, rather than stopping NSSI. This might enhance its utilization., Trial Registration: ClinicalTrials.gov NCT04463654 . Registered on 7 June 2020., (© 2024. The Author(s).)
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- 2024
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13. What kind of science for dual diagnosis? A pragmatic examination of the enactive approach to psychiatry.
- Author
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Larsen JL, Johansen KS, and Mehlsen MY
- Abstract
The recommended treatment for dual diagnosis - the co-occurrence of substance use and another mental disorder - requires seamless integration of the involved disciplines and services. However, no integrative framework exists for communicating about dual diagnosis cases across disciplinary or sectoral boundaries. We examine if Enactive Psychiatry may bridge this theoretical gap. We evaluate the enactive approach through a two-step pragmatic lens: Firstly, by taking a historical perspective to describe more accurately how the theoretical gap within the field of dual diagnosis initially developed. Secondly, by applying the Enactive Psychiatry approach to data from a longitudinal study on the trajectory of cannabis use in psychosis disorders. By applying the theory rather than simply presenting it, we position ourselves better to evaluate whether it may assist the purpose of achieving a more expedient pragmatic "grip" on the field of dual diagnosis. In our discussion, we suggest that this may very well be the case. Finally, we consider the enactive approach as one of a small handful of new theories of mental disorders that draw on systems thinking and ecological psychology, and discuss whether they have the potential for a wider progressive problemshift within psychiatry. The case in favor of such potential, we argue, is less strong unless the role of complexity, similar to that seen within the dual diagnosis field, may be demonstrated for other fields of clinical practice., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Larsen, Johansen and Mehlsen.)
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- 2022
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14. Qualitative factors shaping MS patients' experiences of infusible disease-modifying drugs: a critical incident technique analysis.
- Author
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Larsen JL, Schäfer J, Nielsen HH, and Vestergaard Rasmussen P
- Subjects
- Humans, Natalizumab, Task Performance and Analysis, Multiple Sclerosis drug therapy, Multiple Sclerosis, Relapsing-Remitting drug therapy, Pharmaceutical Preparations
- Abstract
Objective: To explore factors shaping the experiences of patients with relapsing-remitting multiple sclerosis with infusible disease-modifying drugs in a hospital setting., Design and Settings: The critical incident technique served as a framework for collecting and analysing patients' qualitative account practices involving infusible disease-modifying drugs. Data were collected through semistructured interviews and one single-case study. Participants were recruited from all five regions in Denmark. Inductive thematic analysis was used to identify and interpret factors shaping patients' infusion journey over time., Participants: Twenty-two patients with relapsing-remitting multiple sclerosis receiving infusion with disease-modifying drugs (natalizumab, alemtuzumab and ocrelizumab)., Results: Four time scenarios-preinfusion, day of infusion, long-term infusion and switch of infusion-associated with the infusion of disease-modifying drugs were analysed to reveal how different factors could both positively and negatively affect patient experience. Time taken to make the treatment decision was affected by participants' subjective perceptions of their disease activity; this may have set off a treatment dilemma in the event of a pressing need for treatment. Planning and routine made infusion practices manageable, but external and internal surroundings, including infusion room ambience and the quality of relationships with healthcare professionals and fellow patients, affected patients' cognitive state and well-being irrespective of the infusion regimen. Switching the infusion regimen can reactivate worries akin to the preinfusion scenario., Conclusion: This study provides novel insight into the positive and negative factors that shape patients' experience of infusion care practices. From a patient's perspective, an infusion practice is not a solitary event in time but includes planning and routine which become an integral part of their multiple sclerosis management. The quality of space and the ambience of the infusion room, combined with the relationship with healthcare professionals and fellow patients, can be a significant source of knowledge and support people with relapsing-remitting multiple sclerosis in their experience of agency in life., Competing Interests: Competing interests: Outside this work, JS has received travel reimbursements from Teva, Biogen Idec, Roche, Sanofi Genzyme and Merck. PVR has previously received travel reimbursements from Sanofi, Roche and Teva, speaking fees from Teva, Biogen, Novartis and Roche, and a research grant from Novartis. HHN has previously received financial compensation and travel reimbursements from Teva, Biogen Idec, Roche, Sanofi Genzyme and Novartis., (© Author(s) (or their employer(s)) 2020. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)
- Published
- 2020
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15. EBNA1 IgM-Based Discrimination Between Rheumatoid Arthritis Patients, Systemic Lupus Erythematosus Patients and Healthy Controls.
- Author
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Trier NH, Draborg AH, Sternbæk L, Troelsen L, Larsen JL, Jacobsen S, and Houen G
- Abstract
Epstein-Barr Virus (EBV) has been associated with development of rheumatic connective tissue diseases like rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE) in genetically susceptible individuals. Diagnosis of RA and SLE relies on clinical criteria in combination with the presence of characteristic autoantibodies. In addition, antibodies to several EBV antigens have been shown to be elevated in patients with these diseases compared to healthy controls (HC). Here, we elaborated improved enzyme-linked immunosorbent assays for antibodies (IgM, IgA, IgG) to the EBV proteins Epstein-Barr Virus nuclear antigen (EBNA)1 and early antigen diffuse (EAD) in order to determine their potential diagnostic role. We showed that especially EBNA1 IgM distinguished RA from SLE and HCs and also distinguished SLE from HCs. EBNA1 IgA was almost as effective in differentiating RA from SLE and HC, while EAD IgG and IgA were able to discern SLE patients from RA patients and HCs. Collectively, these findings illustrate the potential diagnostic use of antibodies to EBV proteins to diagnose RA and to differentiate SLE from RA.
- Published
- 2019
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16. Immune responses to an early lytic cytomegalovirus antigen in systemic lupus erythematosus patients: T-cell responses, cytokine secretions and antibody status.
- Author
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Draborg AH, Rasmussen NS, Larsen JL, Jørgensen CS, Sandhu N, Skogstrand K, Jacobsen S, and Houen G
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- Adult, Aged, Aged, 80 and over, Antibodies, Viral immunology, Antigens, CD metabolism, Antigens, Differentiation, T-Lymphocyte metabolism, Case-Control Studies, Cytokines analysis, DNA-Binding Proteins immunology, Enzyme-Linked Immunosorbent Assay, Female, Herpesvirus 6, Human metabolism, Humans, Lectins, C-Type metabolism, Lupus Erythematosus, Systemic pathology, Male, Middle Aged, T-Lymphocytes cytology, T-Lymphocytes metabolism, Viral Proteins immunology, Young Adult, Antibodies, Viral blood, Antigens, Viral immunology, Cytokines metabolism, Cytomegalovirus metabolism, Immediate-Early Proteins immunology, Lupus Erythematosus, Systemic immunology, T-Lymphocytes immunology
- Abstract
We investigated immune responses to a lytic cytomegalovirus antigen (CMVpp52), and to a lytic human herpes virus (HHV) 6 antigen (HHV6p41), in systemic lupus erythematosus (SLE) patients and healthy controls (HCs), in order to clarify if the previously established impaired responses to Epstein-Barr virus (EBV) in SLE patients is a general defect in their responses against (all) HHVs. Multiplex Luminex technology results showed a normal induction of five quantified cytokines (interferon γ, interleukin(IL)12, IL17, IL10, and tumor necrosis factor α) in SLE patients compared to HCs upon stimulation with CMVpp52 and HHV6p41. However, flow cytometric results showed a reduced upregulation of the activation marker CD69 on T-cells from SLE patients (n = 17) compared to HCs (n = 17) upon stimulation with CMVpp52, indicating limited or defective CMVpp52-specific T-cells and/or poor antigen-presentation in SLE patients, and thereby possibly decreased control of the CMV infection. In conclusion, the dysfunctional immune response against EBV previously established in SLE patients does not seem to apply to the same degree regarding the immune responses against CMV or HHV6. Results designate that the main contributing HHV agent in development or exacerbation of SLE (in genetically predisposed individuals) is the previously determined uncontrolled EBV infection, and to a lesser extent CMV infection, and probably with no involvement of HHV6 infection.
- Published
- 2018
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17. En unødvendig debatt.
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Larsen JL
- Published
- 2017
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18. Genetic counselors save costs across the genetic testing spectrum.
- Author
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Haidle JL, Sternen DL, Dickerson JA, Mroch A, Needham DF, Riordan CM, and Kieke MC
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- Humans, Cost Savings economics, Cost Savings methods, Genetic Counseling economics, Genetic Testing economics
- Published
- 2017
19. The current state of cancer genetic counseling access and availability.
- Author
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Knapke S, Haidle JL, Nagy R, and Pirzadeh-Miller S
- Subjects
- Delivery of Health Care, Genetic Predisposition to Disease, Genetic Testing, Humans, Neoplasms diagnosis, Neoplasms epidemiology, Risk Assessment, Surveys and Questionnaires, Time Factors, Genetic Counseling methods, Health Services Accessibility, Neoplasms genetics
- Abstract
Purpose: Genetic risk assessment and counseling by a qualified genetics professional are recommended to ensure high-quality care for individuals at risk of hereditary cancer. Timely access to genetic services provided by a genetic counselor (GC) is essential, especially in cases where genetic testing results may affect impending surgical decisions., Methods: A survey of GCs who specialize in cancer genetics was performed to assess service delivery models and ability to accommodate urgent cases., Results: Over half of all respondents indicated that urgent patients can be seen for consultation the same day or within 1-2 business days, and almost all respondents indicated that urgent cases can be seen within 1 week. Most respondents indicated that urgent cases are seen by a GC only with no physician involved., Conclusions: The results of this survey of GCs demonstrate that timely access to cancer genetic counseling by GCs in an urgent setting is available.Genet Med 18 4, 410-412.
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- 2016
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20. Changing of the Guard.
- Author
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Wierman ME, Chin WW, Clemmons DR, Gagel RF, and Larsen JL
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- Endocrinology organization & administration, Periodicals as Topic
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- 2016
- Full Text
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21. Changing of the Guard.
- Author
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Wierman ME, Chin WW, Clemmons DR, Gagel RF, and Larsen JL
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- Endocrinology, Periodicals as Topic, Publishing organization & administration
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- 2015
- Full Text
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22. Trauma symptoms for men and women in substance abuse treatment: a latent transition analysis.
- Author
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Cosden M, Larsen JL, Donahue MT, and Nylund-Gibson K
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- Adolescent, Adult, Female, Humans, Male, Middle Aged, Psychiatric Status Rating Scales, Severity of Illness Index, Symptom Assessment, Young Adult, Sex Characteristics, Stress Disorders, Post-Traumatic diagnosis, Substance-Related Disorders rehabilitation
- Abstract
Differences in trauma symptoms among men and women in two court-involved substance abuse treatment programs were examined using latent transition analysis (LTA). It was hypothesized that women would be more likely to report clinical-level trauma symptoms than would men, but that both groups would show reductions in symptoms over time. Symptom classifications were determined by the LTA. Scores on the Trauma Symptom Inventory (TSI) were obtained on 381 program participants, 112 men and 269 women, at intake and after 6 months in treatment. Three ordered classes were obtained for men and women at each time point: non-clinical (no TSI scales elevated), moderate symptoms (1 or 2 scales elevated) and severe symptoms (all scales elevated). Men were more likely to be represented in the non-clinical class at intake, while women had higher representation in the severe symptoms classification. There was a reduction of trauma symptoms for most men and women, but some groupings had symptoms that remained the same or became worse over time. Using gender and trauma-symptoms to help determine interventions is discussed., (Copyright © 2015 Elsevier Inc. All rights reserved.)
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- 2015
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23. Proceedings from an international consensus meeting on posttransplantation diabetes mellitus: recommendations and future directions.
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Sharif A, Hecking M, de Vries AP, Porrini E, Hornum M, Rasoul-Rockenschaub S, Berlakovich G, Krebs M, Kautzky-Willer A, Schernthaner G, Marchetti P, Pacini G, Ojo A, Takahara S, Larsen JL, Budde K, Eller K, Pascual J, Jardine A, Bakker SJ, Valderhaug TG, Jenssen TG, Cohney S, and Säemann MD
- Subjects
- Humans, Consensus, Diabetes Mellitus etiology, Transplantation adverse effects
- Abstract
A consensus meeting was held in Vienna on September 8-9, 2013, to discuss diagnostic and therapeutic challenges surrounding development of diabetes mellitus after transplantation. The International Expert Panel comprised 24 transplant nephrologists, surgeons, diabetologists and clinical scientists, which met with the aim to review previous guidelines in light of emerging clinical data and research. Recommendations from the consensus discussions are provided in this article. Although the meeting was kidney-centric, reflecting the expertise present, these recommendations are likely to be relevant to other solid organ transplant recipients. Our recommendations include: terminology revision from new-onset diabetes after transplantation to posttransplantation diabetes mellitus (PTDM), exclusion of transient posttransplant hyperglycemia from PTDM diagnosis, expansion of screening strategies (incorporating postprandial glucose and HbA1c) and opinion-based guidance regarding pharmacological therapy in light of recent clinical evidence. Future research in the field was discussed with the aim of establishing collaborative working groups to address unresolved questions. These recommendations are opinion-based and intended to serve as a template for planned guidelines update, based on systematic and graded literature review, on the diagnosis and management of PTDM., (© Copyright 2014 The American Society of Transplantation and the American Society of Transplant Surgeons.)
- Published
- 2014
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24. Reduced response to Epstein-Barr virus antigens by T-cells in systemic lupus erythematosus patients.
- Author
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Draborg AH, Jacobsen S, Westergaard M, Mortensen S, Larsen JL, Houen G, and Duus K
- Abstract
Objective: Epstein-Barr virus (EBV) has for long been associated with systemic lupus erythematosus (SLE). In this study, we investigated the levels of latent and lytic antigen EBV-specific T-cells and antibodies in SLE patients., Methods: T cells were analyzed by flow cytometry and antibodies were analyzed by enzyme-linked immunosorbent assay., Results: SLE patients showed a significantly reduced number of activated (CD69) T-cells upon ex vivo stimulation with EBV nuclear antigen (EBNA) 1 or EBV early antigen diffuse (EBV-EA/D) in whole blood samples compared with healthy controls. Also, a reduced number of T-cells from SLE patients were found to produce interferon-γ upon stimulation with these antigens. Importantly, responses to a superantigen were normal in SLE patients. Compared with healthy controls, SLE patients had fewer EBV-specific T-cells but higher titres of antibodies against EBV. Furthermore, an inverse correlation was revealed between the number of lytic antigen EBV-specific T-cells and disease activity of the SLE patients, with high-activity SLE patients having fewer T-cells than low-activity SLE patients., Conclusions: These results indicate a limited or a defective EBV-specific T-cell response in SLE patients, which may suggest poor control of EBV infection in SLE with an immune reaction shift towards a humoral response in an attempt to control viral reactivation. A role for decreased control of EBV as a contributing agent in the development or exacerbation of SLE is proposed.
- Published
- 2014
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25. Diabetes, pre-diabetes and insulin resistance screening in Native American children and youth.
- Author
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Nsiah-Kumi PA, Lasley S, Whiting M, Brushbreaker C, Erickson JM, Qiu F, Yu F, and Larsen JL
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- Adolescent, Body Mass Index, Child, Child, Preschool, Cross-Sectional Studies, Diabetes Mellitus, Type 2 epidemiology, Diabetes Mellitus, Type 2 prevention & control, Early Diagnosis, Fasting blood, Female, Glucose Tolerance Test, Homeostasis, Humans, Male, Mass Screening, Nebraska epidemiology, Prevalence, Prospective Studies, Blood Glucose metabolism, C-Reactive Protein metabolism, Diabetes Mellitus, Type 2 blood, Indians, North American statistics & numerical data, Insulin blood, Insulin Resistance, Lipids blood, Prediabetic State blood
- Abstract
Objectives: Early identification of pre-diabetes and insulin resistance (IR) provides an important window of opportunity for diabetes prevention. Little is known about the prevalence of pre-diabetes and IR in Native American (NA) youth. We designed a cross-sectional, community-based study of NA children to estimate the prevalence of diabetes, pre-diabetes and IR and their association with other diabetes risk factors., Study Design: NA children (5-18 years) were screened with body mass index (BMI), blood pressure, oral glucose tolerance test (OGTT), lipids, insulin and highly sensitive C-reactive protein (hsCRP), and calculated homeostatic model assessment of IR (HOMA-IR)., Results: Mean age of the cohort (n=201) was 10.8 ± 3.8 years (± s.d.; 94/107 M/F). BMI percentile for age and sex (BMI%) was elevated (≥ 85 th percentile) in 58.6% of 5-11 years and 51.1% of 12-18 years, and positively correlated with HOMA-IR, blood pressure, triglycerides and hsCRP (P<0.05). The prevalence rate for pre-diabetes and diabetes were 6.5% (3.5-10.8%) and 1.0% (0.1-3.6%), respectively. Mean HOMA-IR was greater in the older than younger age group while prevalence of pre-diabetes was the same. Those with pre-diabetes and diabetes had a greater HOMA-IR, abdominal circumference and BMI% than normal youth., Conclusion: In the first prospective, community-based screening for pre-diabetes, IR and diabetes in United States NA youth using OGTT, while the number of diabetes cases was low, pre-diabetes was found in a significant number of youth, particularly in those with BMI ≥ 95 th%. As proportions of pre-diabetes were similar in 5-11 and 12-18 year olds, diabetes risk begins early in NA youth.
- Published
- 2013
- Full Text
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26. Potential risks of metformin in transplant patients.
- Author
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Larsen JL
- Subjects
- Humans, Hypoglycemic Agents therapeutic use, Metformin therapeutic use, Organ Transplantation adverse effects
- Published
- 2012
- Full Text
- View/download PDF
27. Vibrio vulnificus produces quorum sensing signals of the AHL-class.
- Author
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Valiente E, Bruhn JB, Nielsen KF, Larsen JL, Roig FJ, Gram L, and Amaro C
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- Animals, Bacterial Proteins genetics, Carbon-Sulfur Lyases genetics, Chromatography, High Pressure Liquid, DNA, Bacterial genetics, Eels microbiology, Gene Expression Regulation, Bacterial, Genes, Bacterial, Homoserine analogs & derivatives, Homoserine metabolism, Humans, Lactones metabolism, Mass Spectrometry, Vibrio Infections microbiology, Vibrio vulnificus genetics, Acyl-Butyrolactones metabolism, Bacterial Proteins metabolism, Carbon-Sulfur Lyases metabolism, Quorum Sensing, Vibrio vulnificus metabolism
- Abstract
Vibrio vulnificus is an aquatic pathogenic bacterium that can cause vibriosis in humans and fish. The species is subdivided into three biotypes with the fish-virulent strains belonging to biotype 2. The quorum sensing (QS) phenomenon mediated by furanosyl borate diester or autoinducer 2 (AI-2) has been described in human strains of biotype 1, and here we show that the luxS gene which encodes AI-2 is present in all strains of V. vulnificus regardless of origin, biotype or serovar. In this study, we also demonstrate that V. vulnificus produces QS signals of the acylated homoserine lactone (AHL) class (AI-1). AHLs were detected in strains of biotype 1 and 2 from water, fish and human wound infections but not in strains isolated from human septicaemic cases. The AHL compound was identified as N-butanoyl-homoserine-lactone (C(4)-HL) by both reporter strains and by HPLC-high-resolution MS. C(4)-HL was detected when AHL-positive strains were grown in low-nutrient medium [modified sea water yeast extract (MSWYE)] but not in rich media (tryptic soy broth or brain-heart infusion) and its production was enhanced when blood factors were added to MSWYE. C(4)-HL was detected in vivo, in eels infected with AHL-positive biotype 2 strains. No known AHL-related gene was detected by PCR or Southern blot suggesting that AHL-related genes in V. vulnificus are different from those found in other Gram-negative bacteria.
- Published
- 2009
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28. Hepatitis-C prevalence in an urban native-American clinic: a prospective screening study.
- Author
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Neumeister AS, Pilcher LE, Erickson JM, Langley LL, Murphy MM, Haukaas NM, Mailliard ME, and Larsen JL
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- Adult, Female, Hepatitis C Antibodies, Hepatitis C, Chronic etiology, Hepatitis C, Chronic prevention & control, Humans, Male, Middle Aged, Nebraska epidemiology, Prevalence, Prospective Studies, Risk Factors, Substance Abuse, Intravenous complications, Tattooing, United States epidemiology, United States Indian Health Service, Hepatitis C, Chronic ethnology, Hospitals, Urban statistics & numerical data, Indians, North American statistics & numerical data, Mass Screening, Urban Health statistics & numerical data
- Abstract
Background: Native-American populations are disproportionately burdened by chronic liver disease, and the prevalence of hepatitis C (HCV) in native Americans is unknown., Purpose: To determine the prevalence of hepatitis C in a local native-American population via a prospective screening study., Procedures: Two-hundred-forty-three native Americans (161 females/82 males) using an urban clinic and representing > 30 tribes from across the United States were screened. Mean age was 41 +/- 1 years. Hepatitis-C screening was by anti-HCV with confirmation by HCV RNA. A questionnaire assessed potential risk factors for HCV., Findings: Anti-HCV antibodies were found in 11.5% (95% CI: 7.5-15.5%). HCV RNA was present by polymerase chain reaction (PCR) in 8.6% (95% CI: 5.1-12.1%) and was more common in males [13.4% (95% CI: 6.0-20.8%)] than females [6.2% (95% CI: 2.5-9.9%)]. The most common potential risk factors for chronic HCV infection were intravenous (IV) drug or cocaine use (p < 0.0001), tattoos > 5 years old (p < 0.0001) and having a sexual partner with HCV (p = 0.0063)., Conclusion: HCV prevalence is higher in an urban native-American clinic population than reported in the general U.S. population. Use of IV drugs is the most prevalent risk factor, but tattoos and sexual transmission may also be important.
- Published
- 2007
29. Pancreas transplantation: indications and consequences.
- Author
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Larsen JL
- Subjects
- Diabetes Mellitus surgery, Diabetic Angiopathies, Diabetic Nephropathies, Diabetic Neuropathies, Diabetic Retinopathy, Female, Humans, Hypoglycemia, Immunosuppression Therapy, Islets of Langerhans, Kidney Transplantation, Male, Patient Selection, Pregnancy, Quality of Life, Survival Rate, Pancreas Transplantation adverse effects, Pancreas Transplantation methods
- Abstract
Pancreas transplantation continues to evolve as a strategy in the management of diabetes mellitus. The first combined pancreas-kidney transplant was reported in 1967, but pancreas transplant now represents a number of procedures, each with different indications, risks, benefits, and outcomes. This review will summarize these procedures, including their risks and outcomes in comparison to kidney transplantation alone, and how or if they affect the consequences of diabetes: hyperglycemia, hypoglycemia, and microvascular and macrovascular complications. In addition, the new risks introduced by immunosuppression will be reviewed, including infections, cancer, osteoporosis, reproductive function, and the impact of immunosuppression medications on blood pressure, lipids, and glucose tolerance. It is imperative that an endocrinologist remain involved in the care of the pancreas transplant recipient, even when glucose is normal, because of the myriad of issues encountered post transplant, including ongoing management of diabetic complications, prevention of bone loss, and screening for failure of the pancreas graft with reinstitution of treatment when indicated. Although long-term patient and graft survival have improved greatly after pancreas transplant, a multidisciplinary team is needed to maximize long-term quality, as well as quantity, of life for the pancreas transplant recipient.
- Published
- 2004
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30. Pancreas transplantation improves vascular disease in patients with type 1 diabetes.
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Larsen JL, Colling CW, Ratanasuwan T, Burkman TW, Lynch TG, Erickson JM, Lyden ER, Lane JT, and Mack-Shipman LR
- Subjects
- Adult, Blood Pressure, Carotid Arteries diagnostic imaging, Carotid Arteries pathology, Diabetes Mellitus, Type 1 blood, Diabetes Mellitus, Type 1 pathology, Diabetic Angiopathies blood, Follow-Up Studies, Humans, Lipids blood, Middle Aged, Treatment Outcome, Tunica Intima pathology, Tunica Media pathology, Ultrasonography, Diabetes Mellitus, Type 1 surgery, Diabetic Angiopathies surgery, Pancreas Transplantation physiology
- Abstract
Objective: Pancreas transplantation (PTX) normalizes glucose and improves microvascular complications, but its impact on macrovascular disease is still debated., Research Design and Methods: Carotid intima-media thickness (IMT), shown to correlate with cardiovascular disease (CVD) risk and events, was determined prospectively by ultrasonography in successful pancreas transplant recipients to evaluate the effect of PTX on CVD risk. Carotid IMT and CVD risk factors of pancreas transplant recipients (n = 25) were compared with three groups: individuals with type 1 diabetes without significant nephropathy (n = 20), nondiabetic kidney transplant recipients (n = 16), and normal control subjects (n = 32). Mean age of pancreas transplant recipients at the time of transplantation was 42.4 +/- 1.2 years (mean +/- SE) and duration of diabetes was 25.9 +/- 1.4 years., Results: After PTX, HbA(1c) level (P < 0.0001) decreased to normal and, whereas creatinine level (P = 0.0002) decreased, it remained elevated compared with normal control subjects (P < 0.05). Blood pressure, BMI, fasting lipid levels, smoking frequency, and use of hypolipidemic agents were unchanged. Mean carotid IMT was increased in pancreas transplant candidates but decreased by 1.8 +/- 0.1 year after PTX (P = 0.0068), no longer different from that in normal control subjects or patients with type 1 diabetes., Conclusions: Carotid IMT improves after successful PTX within 2 years of the procedure, with normalization of HbA(1c) and improved renal function, independent of changes in lipid levels, BMI, blood pressure, smoking, or use of hypolipidemic agents. This study suggests that CVD risk, future events, and mortality should improve after PTX in the absence of other significant, untreated CVD risk factors.
- Published
- 2004
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31. Influences of temperature, salinity and starvation on the motility and chemotactic response of Vibrio anguillarum.
- Author
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Larsen MH, Blackburn N, Larsen JL, and Olsen JE
- Subjects
- Animals, Colony Count, Microbial, Culture Media, Fish Diseases microbiology, Gene Expression Regulation, Bacterial, Movement, Serine, Vibrio drug effects, Vibrio Infections microbiology, Chemotaxis, Oncorhynchus mykiss microbiology, Sodium Chloride pharmacology, Temperature, Vibrio pathogenicity, Vibrio physiology
- Abstract
The role of growth factors for the motility and chemotaxis of the fish pathogen Vibrio anguillarum was determined. Cells of V. anguillarum were chemotactic to serine in the temperature range 5-25 degrees C and in 0.8-2.7 % NaCl. The chemotactic response was significantly higher at 25 degrees C than at 5 or 15 degrees C. Growth in medium with 1.5 % NaCl gave a higher response than growth with 3 % NaCl; when the salinity of the chemotaxis buffer was raised, the chemotactic response was reduced. The role of starvation was also studied; V. anguillarum showed a high chemotactic response after starvation for 2 and 8 days. Motility and chemotaxis are important virulence factors for this bacterium. Not only was the ability to perform chemotactic motility maintained after starvation, but also it was shown that starvation does not interfere with the ability of the organism to cause infection in rainbow trout after a bath challenge. The swimming speed was reduced at lower temperatures. Within the range of salinity and starvation studied, the motile cells swam with the same velocity, indicating that V. anguillarum under all the examined conditions has a functional flagellum and rotates it with constant speed. Phenamil, a specific inhibitor of Na(+)-driven flagella, reduced the motility of both starved and non-starved cells of V. anguillarum indicating that, in both cases, a Na(+) motive force drives the flagellum.
- Published
- 2004
- Full Text
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32. Evaluation of clinical and laboratory variables as prognostic indicators in hospitalised gastrointestinal colic horses.
- Author
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Ihler CF, Venger JL, and Skjerve E
- Subjects
- Animals, Blood Cell Count veterinary, Colic diagnosis, Colic epidemiology, Female, Horse Diseases etiology, Horse Diseases mortality, Horse Diseases therapy, Horses, Hospitalization, Logistic Models, Male, Norway epidemiology, Predictive Value of Tests, Prognosis, Prospective Studies, ROC Curve, Sensitivity and Specificity, Colic veterinary, Horse Diseases diagnosis, Horse Diseases epidemiology
- Abstract
The present prospective study included 106 horses referred to the Department of Large Animal Sciences, The Norwegian School of Veterinary Science, as non-responders to the initial colic treatment in general practise. In 14 of these cases a required surgical treatment was not performed due to economical or other reasons and were excluded from the study. Clinical and laboratory data were obtained at the arrival in the hospital. The outcome for all analyses was survival/ non-survival. A multivariable logistic regression was performed. The analyses were used in medically (46 horses) and surgically treated cases (46 horses) separately. The same analyses were also run for all 92 horses in a simulated "field" situation, where only clinical variables and D-dimer values were included. The fraction of survivors was 78% in the medical and 48% in the surgical cases. In total 63% of the horses survived. In the final multivariable logistic regression model packed cell volume (PCV) was the only important predictor for medically treated cases, and heart rate and presence of hyperaemic or cyanotic mucous membranes were the predictors in the surgically treated cases as well as in the simulated "field" situation. In conclusion, traditional variables as heart rate, mucous membranes and PCV were the important predictors for the outcome in hospitalised colic cases.
- Published
- 2004
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33. Involvement of a sialic acid-binding lectin with hemagglutination and hydrophobicity of Flavobacterium psychrophilum.
- Author
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Møller JD, Larsen JL, Madsen L, and Dalsgaard I
- Subjects
- Animals, Cattle, Cell Adhesion, Cell Membrane physiology, Erythrocytes microbiology, Flavobacterium classification, Flavobacterium isolation & purification, Humans, Oncorhynchus mykiss microbiology, Serotyping, Virulence, Flavobacterium physiology, Hemagglutination, Lectins physiology, N-Acetylneuraminic Acid metabolism
- Abstract
Strains of Flavobacterium psychrophilum were studied for their ability to adhere and cause agglutination of erythrocytes and yeast cells. Strains of the serotype Th showed low or no hemagglutinating (HA) properties toward human, avian, bovine, and rainbow trout erythrocytes, whereas strains of serotype Fd and Fp(T) exhibited distinct HA properties. None of the strains was able to cause agglutination of yeast cells. Greater adherence specificity toward rainbow trout blood cells was seen for the HA-positive strains. Growth at 5 degrees C, compared to that at 15 degrees C, induced an increase in the hemagglutination of some strains. HA activities of F. psychrophilum were inhibited only by sialic acid (N-acetyl-neuraminic acid), heat treatment at 65 degrees C, and proteinase K treatment and not by any of seven other carbohydrates, periodate oxidation, or treatment with trypsin. The supernatant from washed bacterial cells also showed some HA properties. All strains were shown to be highly hydrophobic by the hydrophobic interaction chromatography test, although some contradictions to the results of the salt aggregation test (showing some strains as less hydrophobic) were seen. These results indicate that the aggregation of F. psychrophilum and erythrocytes depend on a lectin present on the surface of HA-positive F. psychrophilum strains and absent on HA-negative strains. This lectin reacts specifically with sialic acid. The adhesion differences observed for F. psychrophilum strains do not appear to correlate with the virulence but still provide insights into the interaction of F. psychrophilum and rainbow trout.
- Published
- 2003
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34. Comparison of two DNA extractions and nested PCR, real-time PCR, a new commercial PCR assay, and bacterial culture for detection of Mycobacterium avium subsp. paratuberculosis in bovine feces.
- Author
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Christopher-Hennings J, Dammen MA, Weeks SR, Epperson WB, Singh SN, Steinlicht GL, Fang Y, Skaare JL, Larsen JL, Payeur JB, and Nelson EA
- Subjects
- Animals, Bacteriological Techniques methods, Cattle, DNA, Bacterial genetics, Paratuberculosis microbiology, Sensitivity and Specificity, Cattle Diseases diagnosis, Cattle Diseases microbiology, DNA, Bacterial isolation & purification, Feces microbiology, Mycobacterium avium subsp. paratuberculosis isolation & purification, Paratuberculosis diagnosis, Polymerase Chain Reaction methods
- Abstract
In this study, 5 combinations of 2 DNA extractions and 3 polymerase chain reaction (PCR) techniques were compared with culture for the detection of Mycobacterium paratuberculosis directly from bovine feces. These combinations included a new commercial extraction technique combined with a commercial PCR/Southern blot technique, nested PCR (nPCR), or real-time PCR, and a university-developed extraction combined with nPCR or real-time PCR. Four of the 5 combinations had statistically similar sensitivities between 93% and 100% and specificity between 95% and 100%, when compared with culture results from 63 bovine fecal samples. These results indicated that using a commercial extraction with a commercial PCR/Southern blot, nPCR, or real-time PCR, or a university-developed extraction with real-time PCR would result in similar sensitivities to culture for the identification of M. paratuberculosis from bovine feces and are valid alternatives to culture.
- Published
- 2003
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35. [Treatment of acoustic neuroma].
- Author
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Møller P, Myrseth E, Pedersen PH, Kråkenes J, Larsen JL, and Moen G
- Subjects
- Adult, Aged, Facial Paralysis diagnosis, Facial Paralysis etiology, Female, Follow-Up Studies, Hearing Loss diagnosis, Hearing Loss etiology, Humans, Magnetic Resonance Imaging, Male, Middle Aged, Neuroma, Acoustic diagnosis, Postoperative Complications diagnosis, Postoperative Complications physiopathology, Neuroma, Acoustic surgery
- Abstract
Background: Acoustic neuroma is the most common tumour in the cerebello-pontine angle., Material and Methods: We present the results after surgery in 99 cases, and the natural course of the disease in 82 patients followed for up to 20 years (mean 3 years)., Results: During the observation period, 43% of the tumours increased in size. 36% of patients suffered increasing hearing loss. Total removal was accomplished in 92 cases. In 12 cases hearing preservation was attempted; successfully in five cases. 72 patients had normal or near normal postoperative facial nerve function, whereas 19 patients got a facial nerve paralysis. Two patients died, one because of haemorrhagic infarction and cerebellar swelling, and one because of ventricular fibrillation. Five patients had to be reoperated for CSF leakage., Interpretation: Acoustic neuroma treatment is still a challenge. We favour a team approach to treat this condition.
- Published
- 2002
36. [Stereotactic radiosurgery of cerebral arteriovenous malformations].
- Author
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Pedersen PH, Baardsen R, Larsen JL, Thorsen F, and Wester K
- Subjects
- Adolescent, Adult, Aged, Child, Child, Preschool, Female, Follow-Up Studies, Humans, Intracranial Arteriovenous Malformations diagnostic imaging, Male, Middle Aged, Radiation Dosage, Radiography, Treatment Outcome, Intracranial Arteriovenous Malformations surgery, Radiosurgery methods
- Abstract
Background: Different treatment modalities are being used for cerebral arteriovenous malformations., Material and Methods: We have evaluated the results of stereotactic radiosurgery on 85 patients (48 females) with median age 34.5 years (range 4-70 years) treated at Haukeland University Hospital in Norway in 1989-96. Median follow-up time was 7 years 3 months (range 51-144 months). Data were obtained retrospectively from patient files., Results: Haemorrhage was the initial symptom in 72 patients. The majority of lesions were located deep within the brain parenchyma or near critical structures. The minimum dose to the periphery of the malformation was 15 to 33.3 Gy in 30-70% isodose line according to the volume and location of the malformation. Complete obliteration was obtained in 65 of 85 malformations (77%) and in two of five patients who were retreated. 85% of the malformations smaller than 4 cm3; 50% of those larger than 4 cm3 were obliterated after the treatment. The majority of the malformations were obliterated between two and three years after radiation. Radiation-related side effects were observed in six patients. Five patients experienced new bleeding during follow-up., Interpretation: Small and medium-sized arteriovenous malformations are successfully treated with stereotactic radiosurgery with an acceptable rate of radiation-related side effects and latency bleeding.
- Published
- 2002
37. Comparison of real-time, quantitative PCR with molecular beacons to nested PCR and culture methods for detection of Mycobacterium avium subsp. paratuberculosis in bovine fecal samples.
- Author
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Fang Y, Wu WH, Pepper JL, Larsen JL, Marras SA, Nelson EA, Epperson WB, and Christopher-Hennings J
- Subjects
- Animals, Cattle, Cattle Diseases microbiology, Culture Media, Molecular Probes, Mycobacterium avium subsp. paratuberculosis genetics, Paratuberculosis microbiology, Sensitivity and Specificity, Cattle Diseases diagnosis, Feces microbiology, Mycobacterium avium subsp. paratuberculosis isolation & purification, Paratuberculosis diagnosis, Polymerase Chain Reaction methods
- Abstract
An automated PCR with fluorescent probes (molecular beacons) detected Mycobacterium avium subsp. paratuberculosis in bovine feces. When the PCR was compared with culture in testing 41 fecal samples, kappa scores of 0.94 to 0.96, a sensitivity of 93 to 96%, and a specificity of 92% were obtained. Results were quantitated by using a standard curve derived from a plasmid containing IS900. A minimum quantity of 1.7 x 10(-4) pg of DNA, correlating to 1 to 8 CFU, was detected.
- Published
- 2002
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38. Incidence, distribution, and spread of tetracycline resistance determinants and integron-associated antibiotic resistance genes among motile aeromonads from a fish farming environment.
- Author
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Schmidt AS, Bruun MS, Dalsgaard I, and Larsen JL
- Subjects
- Aeromonas isolation & purification, Aeromonas physiology, Animals, Anti-Bacterial Agents pharmacology, Aquaculture, Drug Combinations, Drug Resistance, Bacterial genetics, Incidence, Oxytetracycline pharmacology, Plasmids, Sulfadiazine pharmacology, Trimethoprim pharmacology, Aeromonas drug effects, Conjugation, Genetic, Integrases genetics, Oncorhynchus mykiss microbiology, Tetracycline Resistance genetics, Water Microbiology
- Abstract
A collection of 313 motile aeromonads isolated at Danish rainbow trout farms was analyzed to identify some of the genes involved in high levels of antimicrobial resistance found in a previous field trial (A. S. Schmidt, M. S. Bruun, I. Dalsgaard, K. Pedersen, and J. L. Larsen, Appl. Environ. Microbiol. 66:4908-4915, 2000), the predominant resistance phenotype (37%) being a combined oxytetracycline (OTC) and sulphadiazine/trimethoprim resistance. Combined sulphonamide/trimethoprim resistance (135 isolates) appeared closely related to the presence of a class 1 integron (141 strains). Among the isolates containing integrons, four different combinations of integrated resistance gene cassettes occurred, in all cases including a dihydrofolate reductase gene and a downstream aminoglycoside resistance insert (87 isolates) and occasionally an additional chloramphenicol resistance gene cassette (31 isolates). In addition, 23 isolates had "empty" integrons without inserted gene cassettes. As far as OTC resistance was concerned, only 66 (30%) out of 216 resistant aeromonads could be assigned to resistance determinant class A (19 isolates), D (n = 6), or E (n = 39); three isolates contained two tetracycline resistance determinants (AD, AE, and DE). Forty OTC-resistant isolates containing large plasmids were selected as donors in a conjugation assay, 27 of which also contained a class 1 integron. Out of 17 successful R-plasmid transfers to Escherichia coli recipients, the respective integrons were cotransferred along with the tetracycline resistance determinants in 15 matings. Transconjugants were predominantly tetA positive (10 of 17) and contained class 1 integrons with two or more inserted antibiotic resistance genes. While there appeared to be a positive correlation between conjugative R-plasmids and tetA among the OTC-resistant aeromonads, tetE and the unclassified OTC resistance genes as well as class 1 integrons were equally distributed among isolates with and without plasmids. These findings indicate the implication of other mechanisms of gene transfer besides plasmid transfer in the dissemination of antibiotic resistance among environmental motile aeromonads.
- Published
- 2001
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39. [Neuroradiological methods in ophthalmology].
- Author
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Larsen JL
- Subjects
- Eye Diseases diagnosis, Eye Diseases pathology, Humans, Magnetic Resonance Imaging, Ophthalmic Nerve pathology, Tomography, X-Ray Computed, Eye Diseases diagnostic imaging, Ophthalmic Nerve diagnostic imaging
- Published
- 2001
40. [How are radiographic examinations documented in medical records?].
- Author
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Haldorsen IS and Larsen JL
- Subjects
- Humans, Norway, Prospective Studies, Quality Assurance, Health Care, Registries, Diagnostic Imaging, Medical Records, Radiology Department, Hospital standards, Radiology Information Systems standards
- Abstract
Background: In order to improve the quality of our activity at the Department of Radiology, Haukeland University Hospital, we investigated how the referring clinical departments registered the results from diagnostic imaging., Material and Methods: We made a prospective registration of all hospitalized patients who received one or more diagnostic imaging or interventional procedures during a 24-hour period. Starting three months later, we performed a survey of how the radiological reports had been recorded by the referring departments., Results: Results from 11 of a total of 177 examinations (6%) could not be found in the medical records. Altogether 67 examinations (38%) were not mentioned even as a note in the patient files, and 57 examinations (32%) were not mentioned in the final report at discharge., Interpretation: In our opinion this study demonstrates a considerable potential for improvement in making important information more available to doctors, in the hospital and in general practice.
- Published
- 2000
41. [Patients' knowledge of the effects of X-rays].
- Author
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Fartum AR, Gjertsen JE, and Larsen JL
- Subjects
- Adult, Aged, Electromagnetic Fields adverse effects, Female, Humans, Male, Middle Aged, Patient Education as Topic, Risk Factors, Surveys and Questionnaires, Knowledge, Radiation Effects, Radiation Injuries
- Abstract
Background: Exposure to radiation from different non-medical sources in the community is given more attention in the media. The effects of radiologic examination, however, seldom receive the same amount of interest., Material and Methods: 295 patients were interviewed immediately after an X-ray examination at Haukeland Hospital to investigate what they knew about the effects of X-rays on the human body. In addition we wanted to find out whether referring doctors had informed their patients about possible unwanted effects of the radiological examination., Results: The patients were more aware of possible effects of radiation from high-voltage cables than of the effects from X-raying. Only three patients had been informed by their referring doctors that X-ray examination could have unwanted effects., Interpretation: Information to patients about diagnostic radiation should be improved.
- Published
- 2000
42. Occurrence of antimicrobial resistance in fish-pathogenic and environmental bacteria associated with four danish rainbow trout farms.
- Author
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Schmidt AS, Bruun MS, Dalsgaard I, Pedersen K, and Larsen JL
- Subjects
- Aeromonas drug effects, Aeromonas isolation & purification, Animals, Drug Resistance, Microbial, Flavobacterium drug effects, Flavobacterium isolation & purification, Gram-Negative Bacterial Infections microbiology, Gram-Negative Bacterial Infections veterinary, Microbial Sensitivity Tests, Yersinia drug effects, Yersinia isolation & purification, Anti-Bacterial Agents pharmacology, Environmental Microbiology, Fish Diseases microbiology, Fisheries, Gram-Negative Bacteria drug effects, Oncorhynchus mykiss microbiology
- Abstract
Surveillance of bacterial susceptibility to five antimicrobial agents was performed during a 1-year period in and around four freshwater fish farms situated along a stream in western Denmark. Besides assessing the levels of antibiotic resistance among the culturable fraction of microorganisms in fish, water, and sediment samples, two major fish pathogens (88 Flavobacterium psychrophilum isolates and 134 Yersinia ruckeri isolates) and 313 motile Aeromonas isolates, representing a group of ubiquitous aquatic bacteria, were isolated from the same samples. MICs were obtained applying a standardized agar dilution method. A markedly decreased susceptibility of F. psychrophilum isolates to most antimicrobial agents presently available for use in Danish aquaculture was detected, while the collected Y. ruckeri isolates remained largely sensitive to all therapeutic substances. Comparing the inlet and outlet samples, the increase of the antibiotic-resistant proportions observed among the culturable microflora was more pronounced and statistically significant among the motile aeromonads. High levels of individual and multiple antimicrobial resistances were demonstrated within the collected flavobacteria and aeromonads, thus indicating a substantial impact of fish farming on several groups of bacteria associated with aquacultural environments.
- Published
- 2000
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43. Vibrio anguillarum resistance to rainbow trout (Oncorhynchus mykiss) serum: role of O-antigen structure of lipopolysaccharide.
- Author
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Boesen HT, Pedersen K, Larsen JL, Koch C, and Ellis AE
- Subjects
- Animals, Antibodies, Bacterial metabolism, Blood Bactericidal Activity immunology, Complement Activation, Complement System Proteins metabolism, Hemolysis, Immunity, Innate, Lipopolysaccharides chemistry, Lipopolysaccharides immunology, O Antigens immunology, Oncorhynchus mykiss blood, Serotyping veterinary, Structure-Activity Relationship, Vibrio chemistry, Vibrio classification, Vibrio growth & development, O Antigens chemistry, Oncorhynchus mykiss immunology, Vibrio immunology
- Abstract
The sensitivity of Vibrio anguillarum to the bactericidal effect of rainbow trout serum was investigated with different strains of serogroups O1 and O2a, which are the most frequently found serogroups in clinical outbreaks of vibriosis. All of the V. anguillarum strains were able to activate complement in rainbow trout serum, but smooth strains of V. anguillarum serogroup O1 were resistant to complement-mediated killing in the absence of specific antibodies. In the case of V. anguillarum serogroup O2a strains, 80% of the analyzed strains were resistant to rainbow trout serum even when specific antibodies were present. Analysis of the lipopolysaccharide structures of the tested V. anguillarum strains showed a positive correlation between the O-antigen size of the lipopolysaccharide and resistance to serum killing. The classical complement pathway was responsible for the antibody-dependent serum killing of susceptible V. anguillarum strains. When serum-resistant V. anguillarum serogroup O2a strains were grown in glucose-enriched Lennox L broth, they produced lipopolysaccharide molecules with fewer high-molecular-weight O-antigen units than did strains grown in broth without the addition of glucose. Strains grown in glucose-enriched medium became sensitive to rainbow trout serum killing, indicating that the high-molecular-weight O-antigen side chains prevented the activated complement from damaging the bacterium.
- Published
- 1999
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44. Vibrios associated with mortality in cultured plaice Pleuronectes platessa fry.
- Author
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Pedersen K, Austin B, Austin DA, and Larsen JL
- Subjects
- Animals, Denmark, Fish Diseases mortality, Serotyping, Aquaculture, Fish Diseases microbiology, Flatfishes microbiology, Vibrio classification, Vibrio isolation & purification, Vibrio Infections veterinary
- Abstract
Fifty two bacterial strains, identified as Vibrio spp., were isolated from diseased plaice fry. The most numerous group comprised V. anguillarum (26/52), of which 3 isolates belonged to serogroup O2a, 16 corresponded to serogroup O18, and 7 isolates were non-typeable. All serogroup O18 isolates had identical ribotype patterns. Fourteen isolates were identified as V. splendidus biotype I (n = 11) or V. splendidus-like (n = 3). Seven isolates were V. fluvialis, representing the first isolation of this species in Denmark and the first description of V. fluvialis associated with diseased fish. All V. fluvialis isolates had identical ribotype patterns, indicating the presence of a single clone. The last 5 isolates belonged to 2 different, unidentified Vibrio species (n = 2 and 3, respectively). Although all isolates were recovered from diseased plaice fry, their exact role as pathogens for the fry is as yet uncertain. Selected isolates were tested for virulence to salmon and turbot. When injected into juvenile salmonid fish, the recorded LD50 values were higher than 10(6), indicating that their virulence was relatively low. However, virulence seemed to deteriorate upon subculturing, and therefore, the strains may have been more virulent upon primary isolation from the plaice fry.
- Published
- 1999
45. Occurrence of Vibrio vulnificus biotypes in Danish marine environments.
- Author
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Høi L, Larsen JL, Dalsgaard I, and Dalsgaard A
- Subjects
- Animals, Bacterial Typing Techniques, Cellobiose metabolism, Culture Media metabolism, DNA Probes genetics, DNA, Bacterial genetics, Denmark, Eels microbiology, Fishes microbiology, Geologic Sediments microbiology, Nucleic Acid Hybridization, Oceans and Seas, Polymyxin B pharmacology, Seasons, Shellfish microbiology, Temperature, Vibrio growth & development, Vibrio metabolism, Vibrio isolation & purification, Water Microbiology
- Abstract
During the unusually warm summer in Denmark in 1994, 11 clinical cases of Vibrio vulnificus infection were reported. These reports initiated an investigation of the occurrence of V. vulnificus biotypes in Danish marine environments. Samples of coastal water, sediment, shellfish, and wild fish were analyzed by preenrichment in alkaline peptone water amended with polymyxin B (2.0 x 10(4) U/liter) followed by streaking onto modified cellobiose-polymyxin B-colistin agar. V. vulnificus-like colonies were tested with a V. vulnificus-specific DNA probe. Low densities of V. vulnificus were detected in water (0.8 to 19 CFU/liter) from June until mid-September and in sediment (0.04 to > 11 CFU/g) from July until mid-November. The presence of V. vulnificus was strongly correlated with water temperature. However, we isolated V. vulnificus from water from a mussel farm at a lower temperature than previously reported (7 degrees C). In 1 of the 13 locations studied, V. vulnificus was found in mussels in 7 of 17 samples analyzed; this is the first report of V. vulnificus in European shellfish. V. vulnificus was also isolated from gills, intestinal contents, and mucus from wild fish. Although biotyping of 706 V. vulnificus strains isolated during our investigations revealed that the majority of the strains (99.6%) belonged to biotype 1, biotype 2 was detected in seawater at a low frequency (0.4%). Our findings provide further evidence that seawater can serve as a reservoir and might facilitate spread of V. vulnificus biotype 2 to eels, with subsequent spread to persons handling eels. In conclusion, our data demonstrate that V. vulnificus is ubiquitous in a temperature marine environment and that V. vulnificus biotype 2 is not strictly confined to eels.
- Published
- 1998
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46. Application of Lime ( Citrus aurantifolia ) Juice to Drinking Water and Food as a Cholera-Preventive Measure.
- Author
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Dalsgaard A, Reichert P, Mortensen HF, Sandström A, Kofoed PE, Larsen JL, and Mølbak K
- Abstract
The protective activity of lime juice against cholera was suggested in a recent case-control study from Guinea-Bissau, On the basis of these findings, we investigated the vibriocidal properties of juice from lime ( Citrus aurantifolia ) fruits added to well water, tap water, and food samples. Well-water samples showed initial pH values from 3.5 to 4,9 whereas water samples from municipal or private taps showed initial pH values between 7.5 and 8.3, A 5-log reduction in Vibrio cholerae O1 counts to <100 CFU/ml of well water was shown for two test strains after exposure to 0.5% lime juice (pH 3.3) for 12 min. In tap water, no significant reduction in CFU of V. cholerae was found after exposure to 0% (pH 8.3) and 0.5% (pH 5.6) lime juice whereas exposure to 1.0% lime juice (pH 4.4) for 120 min caused a 5-log reduction to <100 CFU/ml of tap water for the test strains. A 3-log reduction of V. cholerae was found in food samples containing 3.5% and 5.0% lime juice after 120 min exposure. Our results show that during epidemics of cholera in areas without safe sources of drinking water, juice from citrus fruits added to water and food in palatable concentrations may be appropriate measures in reducing the transmission of cholera. However, local characteristics of the water, in particular its alkalinity, should be considered before applying this measure.
- Published
- 1997
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47. Vibrio damsela associated with diseased fish in Denmark.
- Author
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Pedersen K, Dalsgaard I, and Larsen JL
- Subjects
- Animals, Aquaculture, Bacterial Typing Techniques, Denmark, Oncorhynchus mykiss, Plasmids genetics, Sharks, Skates, Fish, Vibrio classification, Water Microbiology, Zoonoses microbiology, Fish Diseases microbiology, Vibrio isolation & purification, Vibrio pathogenicity
- Abstract
A total of 26 Vibrio damsela strains were isolated in Denmark. Fifteen strains were isolated from the head kidney of rainbow trout (Oncorhynchus mykiss) in aquaculture, eight were from organs of two stingrays (Dasyatis pastinaca) held in captivity, two were from organs and pathological material of a nurse shark (Orectolobus ornatus) held in captivity, and one was from the water in the aquarium where the rays and shark were kept. This is the first report on the isolation of V. damsela in Denmark and the first report on this organism associated with diseased farmed rainbow trout. Ecological and epizootiological aspects of the observation are discussed on the basis of phenotypic and genotypic properties of the isolated strains.
- Published
- 1997
- Full Text
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48. Comparison of ribotyping and randomly amplified polymorphic DNA PCR for characterization of Vibrio vulnificus.
- Author
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Høi L, Dalsgaard A, Larsen JL, Warner JM, and Oliver JD
- Subjects
- Animals, Bacterial Typing Techniques, DNA Probes genetics, Eels microbiology, Electronic Data Processing, Escherichia coli genetics, Humans, Vibrio Infections microbiology, RNA, Ribosomal, 16S genetics, RNA, Ribosomal, 23S genetics, Random Amplified Polymorphic DNA Technique, Vibrio classification, Vibrio genetics
- Abstract
A total of 85 isolates of Vibrio vulnificus were characterized by ribotyping with a probe complementary to 16S and 23S rRNA of Escherichia coli and by randomly amplified polymorphic DNA-PCR (RAPD-PCR) with a 10-mer oligonucleotide primer. The RAPD-PCR results were scanned, and the images were analyzed with a computer program. Ribotype membranes were evaluated visually. Both the ribotyping and the RAPD-PCR results showed that the collection of strains was genetically very heterogeneous. Ribotyping enabled us to differentiate U.S. and Danish strains and V. vulnificus biotypes 1 and 2, while the RAPD-PCR technique was not able to correlate isolates with sources or to differentiate the two biotypes, suggesting that ribotyping is useful for typing V. vulnificus strains whereas RAPD-PCR profiles may subdivide ribotypes. Two Danish clinical biotype 2 strains isolated from fishermen who contracted the infection cleaning eels belonged to the same ribotype as three eel strains (biotype 2), providing further evidence that V. vulnificus biotype 2 is an opportunistic pathogen for humans. One isolate (biotype 2) from Danish coastal waters also showed the same ribotype as the eel strains. This is, to our knowledge, the first time the isolation of V. vulnificus biotype 2 from coastal waters has been described.
- Published
- 1997
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49. Phenotypic and genotypic characterization of Vibrio vulnificus: proposal for the substitution of the subspecific taxon biotype for serovar.
- Author
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Biosca EG, Amaro C, Larsen JL, and Pedersen K
- Subjects
- Bacterial Typing Techniques, Humans, Vibrio genetics, Vibrio classification
- Abstract
The classification of Vibrio vulnificus strains into two biotypes has been maintained on the basis of phenotypic properties and eel virulence. Biotype 2 is virulent for eels, negative for the indole reaction, and serologically homogeneous (serogroup E), whereas strains of biotype 1 are avirulent, indole positive, and serologically heterogeneous. In the present study, we phenotypically and genotypically characterized 21 V. vulnificus isolates, recovered mainly from northern Europe, by comparing them with reference strains of both biotypes to look for new isolates of biotype 2. The results of this work revealed that the majority of isolates virulent for eels presented phenotypic traits previously considered characteristics of biotype 2 and specific ribotypes with HindIII. However, among the new isolates we found (i) a serogroup E strain virulent for eels but indole positive and (ii) one isolate not belonging to serogroup E but pathogenic for eels. Since no biochemical test for specific serogroup can with certainty be associated with eel virulence, we propose to classify V. vulnificus strains into serovars instead of biotypes. Thus, we suggest serovar E as the denomination of those strains previously classified as biotype 2. Finally, the occurrence of serogroup E in eels cultured in Norway and Sweden, as well as from human infections and shrimp, has been demonstrated.
- Published
- 1997
- Full Text
- View/download PDF
50. Plasmid profiles, restriction fragment length polymorphisms and O-serotypes among Vibrio anguillarum isolates.
- Author
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Pedersen K, Tiainen T, and Larsen JL
- Subjects
- Polymorphism, Restriction Fragment Length, Serotyping, Plasmids classification, Vibrio genetics, Vibrio isolation & purification
- Abstract
A total of 279 Vibrio anguillarum strains were serotyped and examined for plasmid content. Plasmids were subjected to digestion with restriction enzymes. Most strains belonged to serogroup O1 (39%) and O2 (16%). In total 164 strains (53%) carried plasmids. Of the O1 and O2 isolates, 92% and 30%, respectively, carried one or more plasmids. Restriction fragment length polymorphism (RFLP) analysis of plasmid DNA indicated that plasmids belonged to several groups. Each group seemed to be restricted to a single O-serovar. The largest group was the pJM1-like plasmids among most serovar O1 strains. Most of these plasmids were about 67 kb like the pJM1 plasmid, but various derivatives ranged from 26-77 kb. RFLP studies of the 67 kb plasmids revealed 17 different restriction patterns. Some patterns were dominant among European strains whereas others were dominant among North American strains. The results confirmed the applicability of O-serotyping together with plasmid profile and restriction analysis of plasmids for typing of V. anguillarum. They also indicated that plasmids among strains which belonged to the traditional fish pathogenic serogroups, O1 and O2, showed more homology than did strains from most other serogroups, that were usually non-pathogenic, environmental bacteria.
- Published
- 1996
- Full Text
- View/download PDF
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