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J L Larsen

Publications and source records attributed to J L Larsen.

At least 19 recordsLinked to original sources
PubMed2006

Vibrio vulnificus serovar A: an emerging pathogen in European anguilliculture.

The spread of the emerging pathogen Vibrio vulnificus biotype 2 serovar A in Danish anguilliculture is reported. Serovar A was originally isolated in a Spanish eel farm in 2000 and occurred in Denmark in the summer of 2004, affecting eels of 5-10 g body weight cultured in fresh water. The Danish eels showed clinical signs different from those reported for Spanish eels, such as severe haemorrhages in the head and gill region with necrosis of the soft tissues. Danish isolates were biochemically and serologically identical to Spanish serovar A strains and also highly virulent for eels by both intraperitoneal injection and immersion challenges. Vaccination with Vulnivaccine, a vaccine against V. vulnificus serovar E, cross-protected eels against serovar A. The LD(50) for experimentally infected vaccinated animals was significantly higher than for non-vaccinated animals.

Animals↗
PubMed2003

Recombinant mannan-binding lectin (MBL) for therapy.

Mannan-binding lectin (MBL) is a plasma protein involved in the innate immune response. It binds to a number of micro-organisms and promotes killing of these through complement activation either directly or through opsonization. Clinical evidence indicates that in a variety of situations genetically determined low MBL levels are associated with increased susceptibility to infections. Infusions of plasma-derived MBL into MBL-deficient individuals was found to be safe in preliminary trials, but we considered that sufficient production and product safety could only be achieved through synthesis of recombinant MBL. A transfected human cell line produces MBL showing the same biological activity as plasma-derived MBL, and an essentially identical profile on MS. The production has been scaled up and clinical trials will start this year.

Animals↗
PubMed2003

Characterization of Vibrio strains isolated from turbot (Scophthalmus maximus) culture by phenotypic analysis, ribotyping and 16S rRNA gene sequence comparison.

AIM: The aim of the present study was to clarify the taxonomic status of Vibrio strains isolated from an aquaculture system and to compare the results of the identifications made by phenotypic and molecular methods. METHODS AND RESULTS: Fifty-one Vibrio strains isolated from a turbot (Scophthalmus maximus) aquaculture system were characterized by ribotyping and 16S rRNA gene sequencing. The strains had been identified phenotypically in a previous numerical taxonomy analysis as Vibrio anguillarum, V. mediterranei, V. splendidus, V. aestuarianus, V. ordalii, V. fischeri and V. scophthalmi. Cluster analysis of ribotype patterns showed that the strains were separated into two main groups: V. splendidus-V. lentus and V. scophthalmi groups. The use of 16S rRNA gene sequence allowed differentiation among V. splendidus biovar I and V. lentus strains. CONCLUSIONS: The molecular methods identified strains of V. splendidus biovar I, V. lentus and V. scophthalmi, showing discrepancies with phenotypic characterization. SIGNIFICANCE AND IMPACT OF THE STUDY: The molecular methods, as 16S rRNA gene sequence analysis, are necessary for the identification of phenotypically close species to avoid mis-identifications. Interestingly, this is the first report of V. lentus strains associated to turbot culture.

Animals↗
PubMed2001

Is Aeromonas hydrophila the dominant motile Aeromonas species that causes disease outbreaks in aquaculture production in the Zhejiang Province of China?

The significance of Aeromonas hydrophila in association with disease outbreaks in aquaculture production in the Zhejiang province of China was investigated. Bacteriological examination of moribund fish and crabs resulted in 95 bacterial isolates: 88 bacterial isolates from fish and 7 isolates from crabs. PCR and traditional biochemical methods were used for identification of A. hydrophila. Out of 69 motile aeromonads, 35 isolates were identified as A. hydrophila by biochemical tests. However, 6 of those were not identified as A. hydrophila by a species specific PCR method. Serotyping revealed 2 dominant serotypes (O9 and O97) among A. hydrophila isolates. The data presented show that approximately 42% of the motile aeromonads isolated from disease outbreaks among various fish species were A. hydrophila. It is noteworthy that A. hydrophila accounted for more than 50% of the isolated aeromonands isolated from crucian carp Carassius carassius and Wuchang bream Megalobrama amblycephala with haemorrhagic septicaemia. Although this species was the most frequently isolated organism from internal organs of diseased fish and crabs in the present study, other motile Aeromonas spp. were also found. The PCR assay was useful in preventing misidentification of A. hydrophila, which may occur when only phenotypic tests are employed.

Aeromonas hydrophila↗
PubMed2001

Field testing of a vaccine against eel diseases caused by Vibrio vulnificus.

The field results of a vaccination programme against Vibrio vulnificus serovar E (biotype 2) in a Spanish eel farm are reported. A total of 9.5 million glass eels were vaccinated from January 1998 to March 2000 by prolonged immersion followed by 2 subsequent reimmunisations after 12 to 14 and 24 to 28 d, respectively. The acquired protection and the immune response against serovar E were estimated over a period of 6 mo after vaccination. A similar vaccination schedule was conducted with elvers in a Danish eel farm. In this case, the acquired protection and the immune response against serovar E and the new eel-pathogenic serovars, recently described in Denmark, were evaluated over a short term. The overall results show that the vaccine against V. vulnificus serovar E induces a satisfactory protective immunity during the main growth period of eels (around 6 mo) with a relative percentage survival of 62 to 86% and protects them against the new eel-pathogenic serovars. Vaccination of eels by immersion seems to be the best strategy to prevent diseases caused by V. vulnificus.

Animals↗
PubMed2001

Patients' views on importance and usefulness of plain radiography for low back pain.

STUDY DESIGN: Quantitative and qualitative cross-sectional interview study. OBJECTIVES: To investigate how patients who are referred for plain radiography because of low back pain perceive the importance and usefulness of the examination. SUMMARY OF BACKGROUND DATA: Up to 50% of plain radiography examinations for low back pain may be unnecessary based on clinical criteria. However, many patients have great confidence in these examinations. A further exploration of the patients' views may indicate how their needs can be met without unnecessary use of radiography. METHODS: Ninety-nine patients (65 women, 34 men) 14-91 years of age who were referred from Norwegian general practitioners for plain radiography of the lumbosacral spine were asked to rate the examination as slightly/fairly or very important (93 responded). Chi-squared tests were used to evaluate differences in rating according to age, gender, clinical history, and clinical appropriateness of the examination, as determined by comparing information in the referral form with Norwegian (NR) and British (BR) recommendations for use of radiography. Each of the 99 patients also underwent a semistructured interview that was based on questions about importance, usefulness, and reasons for the radiography referral. Answers were categorized and described using a qualitative method (template analysis). RESULTS: Seventy-two percent (68 of 93) of patients rated radiography as very important. The proportion was higher for men than women (85% vs. 65%, P = 0.04), higher for those with worsening than those with improving/unchanged symptoms (86% vs. 65%, P = 0.03), and higher for inappropriately than appropriately referred patients (NR: 76% vs. 61%, P = 0.17; BR: 81% vs. 56%, P = 0.01). The qualitative analysis showed that the patients related their views on the importance and usefulness of receiving radiography to seven different issues: symptoms and clinical history, information and advice (especially from health care providers), need for emotional support from the physician, need for certainty and reassurance, need for symptom explanation and diagnosis, reliability of radiography compared with clinical evaluation, and expected practical consequences of the radiologic examination. CONCLUSIONS: The finding that inappropriately referred patients tended to rate their radiography referral as more important than appropriately referred patients indicates that the patient's view may be a substantial barrier to appropriate use of radiography. The study identified seven issues underlying the patients' views on importance and usefulness of receiving radiography. Strategies to prevent unnecessary use of plain radiography for low back pain that address these issues are suggested.

Adolescent↗
PubMed2001

Lipoatrophic diabetes and end-stage liver disease secondary to nonalcoholic steatohepatitis with recurrence after liver transplantation.

BACKGROUND: Lipoatrophic diabetes is an insulin resistance syndrome characterized by the complete or partial lack of adipose tissue and disturbances in lipid and glucose metabolism. Nonalcoholic steatohepatitis (NASH) is a well-described change in liver pathology consisting of steatosis, hepatitis, and fibrosis that can be associated with lipoatrophic diabetes. RESULTS: This article describes the first reported case of lipoatrophic diabetes with NASH leading to liver failure and liver transplantation. Before transplantation, the patient required 600-700 U of insulin/day. After transplantation, a dramatic decline in her insulin requirements was observed, despite corticosteroids. Eighteen months after transplantation, her glycemic control worsened, and she developed recurrent NASH on serial liver biopsies. CONCLUSIONS: NASH associated with lipoatrophic diabetes can recur after liver transplantation, and in this case, was accompanied by increased insulin requirements. These results suggest that the development of NASH itself may contribute to the insulin resistance observed in lipoatrophic diabetes.

Adult↗
PubMed2001

In vitro interactions between rainbow trout (Oncorhynchus mykiss) macrophages and Vibrio anguillarum serogroup O2a.

The sensitivity of Vibrio anguillarum serogroup O2a to killing by rainbow trout macrophages in the presence or absence of specific antibodies and complement components was evaluated using an in vitro assay. Fluorescence microscopy revealed that V. anguillarum serogroup O2a was phagocytosed by rainbow trout macrophages. In the absence of specific antibodies and complement components the bacteria were killed to a limited extent by the macrophages and there was no increased killing if the bacteria were opsonised with either antibodies or antibodies and complement. Furthermore, activated macrophages did not show enhanced ability to kill the bacteria. Vibrio anguillarum serogroup O2a were susceptible to both cell-free superoxide anion (O2-) and hydrogen peroxide (H2O2), which might be generated during the macrophage respiratory burst and the bacteria did not quench cell-free O2-. However, the production of O2- by macrophages was undetectable during the first 30 min following infection and no respiratory burst was inducible by phorbol myristate acetate (PMA) 4 h after infection with V. anguillarum. This suggests that the bacteria were able to inhibit the production of O2- by the infected macrophages. Naive fish were protected when passively immunised with anti-V. anguillarum serogroup O2a antiserum. However, previous results suggest that antibodies are unlikely to provide the fish with protective immunity directly through activation of the complement system and lysis of the bacterial cells. The present in vitro findings suggest that the protective mechanisms of antibody against V. anguillarum serogroup O2a may not involve the opsonising effect of antibodies for enhanced killing by macrophages. However, the possibility exists that such antibodies may prevent the attachment of the pathogen to the host's tissues.

Animals↗
PubMed2001

Cyclosporine challenge test revisited: does it predict outcome after solitary pancreas transplantation?

BACKGROUND: The selection of patients for solitary pancreas transplantation (PTA) requires identification of individuals who will not develop acute renal dysfunction in response to immunosuppressants. A cyclosporine challenge test (CCT) was developed to predict post-PTA kidney dysfunction secondary to calcineurin inhibitor immunosuppressants. We now report on the long-term follow-up of patients who received a PTA after undergoing a CCT. METHODS: Twelve potential PTA recipients were administered cyclosporine A (CsA) for 6 wk. Creatinine clearance (CrCl) was measured at 2, 4, and 6 wk. Those who did not fail the CCT received PTA. Baseline and post-transplant CrCl were retrospectively evaluated in the original cohort and in a group of matched patients who received PTA without a CCT. RESULTS: Of the original 12 recipients evaluated with the CCT, 6 received PTA. CrCl was followed for a mean of 45.8 months. Of the 4 who remained alive, 2 went on to develop renal failure (CrCl < 30 mL/min) at 18 and 65 months post-transplant. The baseline CrCl was higher in PTA recipients who had not been selected to be studied with CCT than those that were (117 +/- 32 vs 78 +/- 13 mL/min). By 12 months post-PTA, the CrCl was no longer different between the groups selected to be screened with CCT and those that were not. CONCLUSIONS: CCT may help predict risk for short-term changes in renal function (< 18 months) in response to CsA. CCT may be most helpful in candidates for PTA with borderline renal insufficiency (60-80 mL/min).

Adult↗
PubMed2001

Comparison of selective media for the detection of Vibrio vulnificus in environmental samples.

AIMS: To compare two selective agars, cellobiose-colistin (CC) agar and a modification of the Vibrio vulnificus medium (VVMc agar), for the isolation of Vibrio vulnificus from environmental samples. METHODS AND RESULTS: The efficiencies of recovery of V. vulnificus collection strains on CC, VVM, VVMc and on thiosulphate-citrate-bile salts-sucrose (TCBS) agar were compared and similar efficiencies were obtained. A slightly higher recovery was observed on VVMc agar. The detection of V. vulnificus in environmental samples (eels and water) was performed by combining culture-based methods (CC and VVMc agars) with DNA-based methods using species-specific probes based on the cytolysin-haemolysin and the 16S rDNA genes. A lower accompanying microbiota was found on CC agar than on VVMc agar. CONCLUSION: The comparison between CC and VVMc agars confirms that both are useful for the detection of V. vulnificus in environmental samples. However, the use of any of these media should be combined with a species-specific probe. SIGNIFICANCE AND IMPACT OF THE STUDY: The combined use of a selective medium and a specific probe provides a feasible method for the detection of V. vulnificus for epidemiological and ecological studies.

Cell Culture Techniques↗
PubMed2001

Characterization of class 1 integrons associated with R-plasmids in clinical Aeromonas salmonicida isolates from various geographical areas.

Class 1 integrons were found in 26 of 40 antibiotic-resistant isolates of the fish pathogen Aeromonas salmonicida from Northern Europe and North America. Three different dhfr genes, conferring trimethoprim resistance, and one ant(3")1a aminoglycoside resistance gene were identified as gene inserts. The gene cassettes tended to be conserved among isolates from a particular geographical area. Nineteen isolates transferred R-plasmids carrying different tet determinants to Escherichia coli in filter mating assays, and in 15 cases, the class 1 integrons were co-transferred. Transferable sulphadiazine, trimethoprim and streptomycin resistances were invariably encoded by integrons. It thus appears that integron-encoded antibiotic resistance genes contribute substantially to the horizontal spread of antimicrobial resistance within this species, being associated with conjugative plasmids.

Aeromonas↗
PubMed2001

Incidence, distribution, and spread of tetracycline resistance determinants and integron-associated antibiotic resistance genes among motile aeromonads from a fish farming environment.

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.

Aeromonas↗
PubMed2000

[How are radiographic examinations documented in medical records?].

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.

Diagnostic Imaging↗
PubMed2000

[Patients' knowledge of the effects of X-rays].

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.

Adult↗
PubMed2000

Reproductive hormones after pancreas transplantation.

BACKGROUND: Reproductive hormone function after pancreas transplantation (PTX) is unknown as it has not been studied. METHODS: We prospectively studied PTX recipients to determine changes in reproductive hormones after PTX. Testosterone or estradiol, leutinizing hormone, follicle stimulating hormone, and prolactin were determined before and 1 year after PTX in 23 patients (10 women, 13 men) followed for more than 1 year after PTX. Of these, 11 received simultaneous kidney-PTX; 8 PTX only; and 4, PTX after kidney. Average age was 38.4+/-1.6 years and average duration of diabetes was 24.5+/-1.3 years. Nine (four women, five men) patients had been on dialysis pre-PTX. Sixteen of 23 patients were treated with cyclosporine and seven with FK-506 along with prednisone and azathioprine post-PTX. RESULTS: Mean testosterone in men was normal pre- and post-PTX. Two men had secondary hypogonadism pre-PTX with resolution in one and persistence in the other post-PTX. Five of the ten women had evidence of hypogonadism pre-PTX: three had primary hypogonadism and two had secondary hypogonadism. Post-PTX, 7 of 10 women had abnormal reproductive hormones: 4 had primary hypogonadism, 2 had secondary hypogonadism, and 1 developed hyperestrogenemia with elevated estradiol (482 pg/ml) and leutinizing hormone (41 IU/liter). Mean prednisone dose and cyclosporine trough level were higher in the women than the men (P<0.05). No cases of secondary hypogonadism that developed or resolved post-PTX were related to changes in prolactin, renal function, or hyperglycemia. CONCLUSIONS: Women are more likely than men to have reproductive hormone abnormalities pre- and post-PTX and the causes may be multiple.

Adult↗
PubMed2000

Pulsed-field gel electrophoriesis analyis of Aeromonas salmonicida ssp. salmonicida.

A total of 133 strains of Aeromonas salmonicida ssp. salmonicida, isolated from a wide variety of sources, were characterized by pulsed-field gel electrophoresis patterns. Sixteen profiles were demonstrated, with one profile being predominant in samples from all the countries and species of fish. Our results suggest a clonal distribution of this subspecies, with a predominant clone being responsible for most of the outbreaks worldwide.

Aeromonas↗