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M E Nielsen

Publications and source records attributed to M E Nielsen.

15 recordsLinked to original sources
PubMed2006

The eel immune system: present knowledge and the need for research.

The European eel, Anguilla anguilla, is one of the most important warm water fish species cultured in southern Europe and the Mediterranean as well as in northern countries including Germany, the Netherlands and Denmark. The Japanese eel, A. japonica, is an important cultured fish in several Asiatic countries including Japan, China and Taiwan. During recent decades, research has been performed to elucidate the immune response of these species against different pathogens (viruses, bacteria or parasites). Nevertheless, there is very limited information in terms of both cellular and humoral immune responses. This review summarizes the present knowledge relating to the eel immune system and includes new data.

Anguilla↗
PubMed2003

The kinetics of antibody production in mucus and serum of European eel (Anguilla anguilla L.) after vaccination against Vibrio vulnificus: development of a new method for antibody quantification in skin mucus.

Vibrio vulnificus serovar E, a bacterial pathogen for eels cultured in intensive systems, is transmitted through water and enters into new hosts mainly via gills. The main objective of this work was to study the kinetics of antibody production to V. vulnificus in serum and mucus and their relationship with protection after vaccination. To quantify local mucus antibodies, a new "in situ" dot blot immunoassay using image analysis has been developed. This assay was applied to measure antibody production in the skin zone next to the gills. We found that (i) the immune response in mucus was faster (peak at days 3-4) and shorter in duration (titres significantly elevated up to day 5 and 11 for skin zone next to the gills and for general cutaneous mucus, respectively) than in serum (peak at day 7; titres significantly elevated for more than 25 days); (ii) the exposure of vaccinated eels with basal levels of local antibodies to sub-lethal dose of the pathogen stimulated a more lasting secreted antibody production (for more than 14 days); (iii) protection and antibody levels in serum were clearly correlated, and (iv) immunised eels with basal levels of serum antibodies and maximal levels of local antibodies were partially protected.

Anguilla↗
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

Gibberellin response mutants identified by luciferase imaging.

The gibberellin (GA) 20-oxidase encoded by Arabidopsis GA5 catalyzes the synthesis of active GAs. GA5 is a regulatory step in GA biosynthesis as GA5 mRNA levels are negatively regulated by its bioactive GA products. A fusion between the GA5 promoter and the firefly luciferase reporter (GA5-LUC) was shown to be similarly regulated, indicating GA feedback of GA5 occurs at the transcriptional level. The fidelity of the GA5-LUC reporter permitted a fusion genetic screen to identify mutants altered in transgene expression. This bioimaging screen identified two types of recessive mutants with increased LUC activity and apparent GA-related growth phenotypes, a dwarf (lue1) and two late flowering mutants (fpa1-3 and fpa1-4). Mutant progeny exhibited altered levels of LUC and of endogenous GA5 and other GA-regulated mRNAs. SSLP-based mapping localized lue1 to chromosome I near the ga2 locus, although complementation analyzes showed that lue1 is not allelic to ga2. Mapping and complementation analyzes showed that the late flowering mutants are allelic to fpa1. This provides genetic evidence for crosstalk between the autonomous and gibberellin-dependent flowering pathways.

Arabidopsis↗
PubMed2001

Control of specific gene expression by gibberellin and brassinosteroid.

We identified a recessive, brassinolide-insensitive mutant caused by a deletion allele (bri1-201) of the brassinosteroid (BR) receptor BRI1. The bri1-201 mutant displayed altered expression levels of genes differentially regulated by gibberellin (GA). RNA-blot analysis revealed that BR and GA antagonistically regulate the accumulation of mRNAs of the GA-responsive GASA1 gene, as well as the GA-repressible GA5 gene. Expression studies with cycloheximide indicated that the antagonistic effects of GA and BR on GA5 require de novo protein synthesis. Reporter transgene analyses and RNA-blot analysis showed that BR and GA modulate GA5 expression, at least in part, at the transcriptional level, and that the signals are independent and subtractive.

Arabidopsis↗
PubMed2000

Descriptions of religious experience using trait and affect adjectives.

66 adults rated the relevance of adjectives representing dimensions of affect and personality for describing how they felt during religious experiences. Adjectives, representing positive affect (enthusiastic, at ease), low neuroticism (calm, relaxed), and high agreeableness (soft-hearted, sympathetic), conscientiousness (conscientious, reliable), and extraversion (sociable, talkative), were rated to be descriptive of religious experiences. The failure of openness to discriminate religious experiences is consistent with Block's criticism (1995) of the five-factor model of personality.

Adult↗
PubMed2000

Physiological and endocrinological responses during prolonged exercise in hatchery-reared rainbow trout (Oncorhynchus mykiss).

Rainbow trout (Oncorhynchus mykiss) were subjected to vigorous exercise (1.5 body length s-1), low exercise (0.5 body length s-1) or still-water (0.0 body length s-1). Hematocrit, glucose, growth hormone (GH), cortisol and triiodo-L-thyronine (T3) were monitored at the start of exercise, after 24 h, and after 2, 4, 8, 16 and 32 days of continuous swimming. Morphological indices and food intake were also monitored. At the end of the experiment, trout subjected to low exercise had gained significantly (p < 0.05) more weight than both the control (still-water) and vigorously exercised fish. This low exercised group of fish also consumed more food than the 2 other groups. Hematocrit increased significantly in both exercised groups at the onset of swimming but returned to pre-exercise levels within 8 hrs. Plasma glucose appeared to be generally unaffected by exercise. Likewise, plasma concentrations of both GH and T3 were not influenced by exercise. Plasma cortisol levels increased in an exercise dependent fashion at the onset of swimming, but returned to pre-swimming levels within 24 h and there was no apparent effect of sustained swimming. The results suggest: (i) the onset of exercise elicits transient changes in plasma components, (ii) the observed weight gain in low exercising salmonids occur without increases in circulating levels of GH or T3.

Animals↗
PubMed1999

Chemoattraction of Ichthyophthirius multifiliis (Ciliophora) theronts to host molecules.

Mechanisms in the host-finding process of Ichthyophthirius multifiliis were studied in vitro by a novel bioassay using 24-well multidishes supplied with bottom layers of agar with chemoattractants. It was shown that low molecular weight molecules (carbohydrates, amino acids, fatty acids, urea) did not attract theronts. In contrast, sera and mucus from a range of teleosts (including marine fish) were effective attractants. Fractionation by gel filtration of fish serum allowed determination of the molecular size of the attracting proteins. Further biochemical studies suggested the chemoattractants to be present in fractions with host immunoglobulin and some still undetermined proteins. No clear association between enzyme activity and chemotactic potential was seen. The high chemoattractive effect of serum from various unrelated teleosts corresponds to the low host specificity of I. multifiliis and suggests that serum factors in mucus could be involved in host finding of the parasite. Society for Parasitology Inc.

Animals↗
PubMed1999

An enhanced humoral immune response against the swimbladder nematode, Anguillicola crassus, in the Japanese eel, Anguilla japonica, compared with the European eel, A. anguilla.

The humoral immune response in the two eel species, Anguilla japonica and Anguilla anguilla against two fractions of antigens in Anguillicola crassus were studied. Within species, both eel species showed significantly elevated titres compared with controls when immunized with antigens from Anguillicola crassus. In interspecific comparison, Anguilla japonica showed significantly elevated titres in comparison with Anguilla anguilla. Immunization of Anguilla anguilla caused a significantly decrease in the plasma levels of protein in comparison with control fish and all groups of Anguilla japonica. In contrast, Anguilla japonica showed significantly lower plasma levels of Ig in all groups compared with Anguilla anguilla. The different susceptibilities to Anguillicola crassus between the natural host, Anguilla japonica, and the naive, Anguilla anguilla, is partly due to differences in the ability of the two eel species to mount a humoral immune response.

Anguilla↗
PubMed1983

Reproducibility of mammographic classifications.

Wolfe's mammographic classification and a percentage classification are statistically evaluated for inter- and intraobserver bias and agreement by seven mammographers with a set of 200 xeromammograms. The results demonstrate significant bias and disagreement with both methods, raising questions about the clinical limitations of these or other mammographic classifications. However, about 90% of the percentage classifications of pairs of readers are within adjacent categories. This suggests that (1) more experience with precisely defined classifications and protocols, (2) the development and application of readily available instructional materials, and (3) studies to identify and evaluate sources of variation in such classifications may eventually lead to acceptable levels of reproducibility.

Breast Neoplasms↗
PubMed1982

Preoperative CT evaluation of adrenal glands in non-small cell bronchogenic carcinoma.

Preoperative chest computed tomographic (CT) scans in 84 patients with biopsy-proved non-small cell bronchogenic carcinoma were reviewed. At least one adrenal gland was visualized in 70 of these. Evidence of a solid adrenal mass was present in 18 (14.5%) glands in 15 (21.4%) patients. Percutaneous needle aspiration under CT guidance confirmed metastatic malignancy in the four patients who were biopsied. Because the documented presence of adrenal metastases in non-small cell lung cancer makes surgical resection or local irradiation inappropriate, it is recommended that both adrenal glands in their entirety be specifically included whenever a staging chest CT examination is performed in patients with such tumors. Percutaneous needle biopsy for pathologic confirmation of the nature of solid adrenal masses discovered in this process is also useful.

Adrenal Gland Neoplasms↗