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Haemagglutination Activity (haemagglutination + activity)

Distribution by Scientific Domains

Earth and Environmental Science	50%

Selected Abstracts

Prebiotics in aquaculture: a review

AQUACULTURE NUTRITION, Issue 2 2010
E. RINGØ
Abstract A prebiotic is a non-digestible food ingredient that beneficially affects the host by selectively stimulating the growth and/or the activity of one or a limited number of bacteria in the colon. Despite the potential benefits to health and performance as noted in various terrestrial animals, the use of prebiotics in the farming of fish and shellfish has been less investigated. The studies of prebiotics in fish and shellfish have investigated the following parameters: effect on growth, feed conversion, gut microbiota, cell damage/morphology, resistance against pathogenic bacteria and innate immune parameters such as alternative complement activity (ACH50), lysozyme activity, natural haemagglutination activity, respiratory burst, superoxide dismutase activity and phagocytic activity. This review discusses the results from these studies and the methods used. If the use of prebiotics leads to health responses becoming more clearly manifested in fish and shellfish, then prebiotics might have the potential to increase the efficiency and sustainability of aquaculture production. However, large gaps of knowledge exist. To fully conclude on the effects of adding prebiotics in fish diets, more research efforts are needed to provide the aquaculture industry, the scientific community, the regulatory bodies and the general public with the necessary information and tools. [source]

Effect of immunostimulants on the haemolymph haemagglutinins of tiger shrimp Penaeus monodon

AQUACULTURE RESEARCH, Issue 12 2008
Roshan Pais
Abstract The levels of haemagglutinins in Penaeus monodon, following administration of immunostimulants, ,-glucans and/or vibrio bacterin either orally or by immersion, were studied. The freshly drawn haemolymph was incubated with microbial materials like ,-glucans/vibrio bacterin and serum obtained after coagulation was administered to naïve animals. The immunostimulant treatments either via immersion, feeding or injection were found to cause an increase (P<0.006) in haemagglutination activity (HA) of the haemolymph against mouse erythrocytes. Injection of saline or heterologous haemolymph caused an increase in the HA, but injection of haemolymph serum obtained by clotting haemolymph in the presence of vibrio bacterin or glucan did not bring about an increase in HA. There was no change in the haemolymph protein profile of the groups receiving immunostimulants through immersion or feed. Two protein bands (27 and 30 kDa), which were present in the uninjected group, were found to be overexpressed in the haemolymph-injected groups. Three bands of 17, 21 and 23 kDa, which were absent in control or saline-injected groups, were present in all the haemolymph serum-injected groups. The study indicates that modulation of HA may partly account for the immunomodulatory activity of immunostimulants like ,-glucan or vibrio bacterins. [source]

Sugar-complex structures of the C-half domain of the galactose-binding lectin EW29 from the earthworm Lumbricus terrestris

ACTA CRYSTALLOGRAPHICA SECTION D, Issue 1 2009
Ryuichiro Suzuki
R-type lectins are one of the most prominent types of lectin; they exist ubiquitously in nature and mainly bind to the galactose unit of sugar chains. The galactose-binding lectin EW29 from the earthworm Lumbricus terrestris belongs to the R-type lectin family as represented by the plant lectin ricin. It shows haemagglutination activity and is composed of a single peptide chain that includes two homologous domains: N-terminal and C-terminal domains. A truncated mutant of EW29 comprising the C-terminal domain (rC-half) has haemagglutination activity by itself. In order to clarify how rC-half recognizes ligands and shows haemagglutination activity, X-ray crystal structures of rC-half in complex with d -lactose and N -acetyl- d -galactosamine have been determined. The structure of rC-half is similar to that of the ricin B chain and consists of a ,-trefoil fold; the fold is further divided into three similar subdomains referred to as subdomains ,, , and ,, which are gathered around the pseudo-threefold axis. The structures of sugar complexes demonstrated that subdomains , and , of rC-half bind terminal galactosyl and N -acetylgalactosaminyl glycans. The sugar-binding properties are common to both ligands in both subdomains and are quite similar to those of ricin B chain,lactose complexes. These results indicate that the C-terminal domain of EW29 uses these two galactose-binding sites for its function as a single-domain-type haemagglutinin. [source]