Biomedical subjects

S Lapatra

Publications and source records attributed to S Lapatra.

3 recordsLinked to original sources

PubMed2006

Ichthyophonus-induced cardiac damage: a mechanism for reduced swimming stamina in salmonids.

Swimming stamina, measured as time-to-fatigue, was reduced by approximately two-thirds in rainbow trout experimentally infected with Ichthyophonus. Intensity of Ichthyophonus infection was most severe in cardiac muscle but multiple organs were infected to a lesser extent. The mean heart weight of infected fish was 40% greater than that of uninfected fish, the result of parasite biomass, infiltration of immune cells and fibrotic (granuloma) tissue surrounding the parasite. Diminished swimming stamina is hypothesized to be due to cardiac failure resulting from the combination of parasite-damaged heart muscle and low myocardial oxygen supply during sustained aerobic exercise. Loss of stamina in Ichthyophonus-infected salmonids could explain the poor performance previously reported for wild Chinook and sockeye salmon stocks during their spawning migration.

Administration, Oral↗

PubMed2004

Anaphylatoxin-like molecules generated during complement activation induce a dramatic enhancement of particle uptake in rainbow trout phagocytes.

Here we have identified a serum fraction containing approximately 8-kDa molecules with an unexpected capacity to greatly enhance particle uptake in trout head kidney leukocytes (HKLs). This approximately 8-kDa particle-uptake enhancing fraction (PUEF-8) was purified from complement-activated serum by gel filtration chromatography. Mass spectrometric analysis and reactivity of anti-trout C3-1 and C4 antibodies, indicated the presence of C3a, C4a and C5a molecules in PUEF-8. Using a newly developed flow cytometric assay that measures the capacity of cells to ingest fluorescent beads, we showed that PUEF-8 induced a striking enhancement (344+/-50% higher than the PBS control value) in the number of HKLs ingesting three or more beads. In contrast, the effect of PUEF-8 on peripheral blood leukocytes (PBLs) was almost negligible. Interestingly, PUEF-8 acted as a strong chemoattractant for both HKLs and PBLs. These findings suggest a novel role for the anaphylatoxins generated during complement activation in teleost fish.

Anaphylatoxins↗

PubMed2002

The acute phase response of rainbow trout (Oncorhynchus mykiss) plasma proteins to viral, bacterial and fungal inflammatory agents.

The innate arm of the immune system responds to inflammatory stimuli by the activation of phagocytes, and by altered levels of several plasma proteins. These changes in plasma proteins comprise a major component of the acute phase response, which is thought to be an adaptive response that contributes to regaining homeostasis after tissue injury or infection. In this study, rainbow trout (Oncorhynchus mykiss) were injected with a variety of potential inflammatory agents, and changes in the concentrations of plasma proteins were sought in polyacrylamide gels in which plasma proteins had been electrophoresed. Bacteria, viruses and yeast all induced changes in plasma protein profiles. Increases were first evident 2 days after injections, and most were evident within 1 week. The greatest number of changes occurred after injection with a Vibrio bacterin emulsified in Freund's incomplete adjuvant. While some proteins increased and others decreased following several treatments, other proteins changed only in response to injections of viruses or viral proteins, and others changed in response to bacterial components. Some proteins that increased after yeast injection decreased after injection of viral components. The partial amino acid sequence of one increased protein identified it as haptoglobin.

Acute-Phase Proteins↗