Biomedical subjects

J L Larsen

Publications and source records attributed to J L Larsen.

201 records · Page 12Linked to original sources

PubMedDate not supplied

The ulcus-syndrome in cod (Gadus morhua). V. Prevalence in selected Danish marine recipients and a control site in the period 1976--1979.

The ulcus-syndrome in cod occurred in marine recipients receiving effluents from sugar and cellulose factories. The mean percentages in the years 1976--77 were for Køge, Assens and Nykøbing F. 10.8%, 31.5%, and 7.4%, respectively, while two among 4,211 were affected at the control site, Hundested (Fig. 2). The disease was most prevalent in autumn (Fig. 3) and the primary stages 1 and 2 with papules and erosions were dominating (Fig. 4). One to two year old cod were most frequently attacked by the diseases, but without any significant decrease in condition factor. On the contrary fish with traumatic injuries had a significant lower condition factor than controls (Table II and III). During autumn's 1976-79, 19,238 cod were examined. The mean values for the prevalence of the ulcus-syndrome in Køge, Assens and Nykøbing F. were 12.5%, 41%, and 8%, respectively, while the variations were from 4-20%, 20-48%, and 0-17%, respectively. The problem was negligible at the control site (Table IV). The discussion concerns some aspects that might be of importance for evaluating this pathobiological parameter for use in biological effects monitoring.

Animals↗

PubMedDate not supplied

Effect of pectin on secretion in pig jejunal loops challenged to enteropathogenic E. coli or enterotoxin (LT). A preliminary report.

Perorally administered pectin in pigs could reduce the fluid accumulation in intestinal loops challenged to different dilutions of enteropathogenic E. coli strains, no effect was observed to enterotoxin (LT) preparations. Pectin seems to interact with the bacterial colonization. The neutralizing effect was most pronounced with low inoculation doses in the loops (10(3) and 10(5)), while high doses (10(9)) permitted the strains to exert their enteropathogenic effect (Table I). Different batches gave different effects (Table II) and some preparations were extraordinarily effective (Table III). Thus standardisation and testing is important in developing pectin preparations for diarrhoea prophylaxis.

Animals↗

PubMedDate not supplied

The ulcus-syndrome in cod (Gadus morhua). IV. Transmission experiments with two viruses isolated from cod and Vibrio anguillarum.

Vibrio anguillarum is a serious fish pathogenic bacterium, but it was not found capable of producing the ulcus-syndrome by different inoculation methods in cod. It was possible to transmit the ulcus-syndrome from cod with the papulo-vesicular stage to apparently healthy cod, when they were kept in the same aquarium. Scarification and inoculation with ground papule material lead to development of the ulcus-syndrome. Inoculation of rhabdovirus failed to produce the ulcus-syndrome. Intracardial inoculation of an icosahedral virus suspension could produce the initial papulo-vesicular stage of the ulcus-syndrome in 13 out of 57 inoculated cod (23%). In another experiment 8 out of 36 (22%) inoculated cod developed the ulcus-syndrome and 1 out of 24 (4%) in the control group developed the ulcus-syndrome. In a third experiment 20 inoculated cod failed to develop the ulcus-syndrome. In a number of other cases where the icosahedral virus probably was present in the inoculation material the ulcus-syndrome was also produced, but with a lower frequency. It is indicated, that the isolated icosahedral virus plays a role in the pathogenesis of the ulcus-syndrome in cod, and that Vibrio anguillarum is important for the further progress of the disease.

Animals↗