Rachycentron canadum (cobia) lectin promoted mitogenic response in mice BALB/c splenocytes.

The mitogenic lectins are invaluable tools to study the biochemical changes associated with lymphocyte activation and proliferation of various immune cells. Rachycentron canadum lectin (RcaL) was detected and purified from serum of cobia fish. The aim of this study was to evaluate the proliferative response and cytokine production in splenocytes of mice in vitro stimulated with RcaL lectin; Canavalia ensiformis lectin (Con A) was used as positive control. A high proliferation index was induced by RcaL in relation to control cells. Furthermore, RcaL induced higher IL-2 and IL-6 production in relation to control. The cell viability was 90% in splenocytes treated with RcaL lectin, but RcaL promoted significant late apoptosis after 24 and 48 h in relation to control. RcaL induced proliferative responses suggesting that this lectin can be used as a mitogenic agent in immunostimulatory assays.

Radiological characterisation of disposed phosphogypsum in Brazil: evaluation of the occupational exposure and environmental impact.

Phosphogypsum, a waste by-product derived from the wet process production of phosphoric acid, represents a serious problem facing the phosphate industry in Brazil. This by-product (mainly calcium sulphate dihydrate) precipitates during the reaction of sulphuric acid with phosphate rock and is stored at a rate of about 4x10(6) kg per day on several piles in Cubatão, Brazil. Contents of natural radionuclides from thorium and uranium series were measured in Brazilian phosphogypsum samples from disposal piles, using high-resolution gamma ray spectrometry and instrumental neutron activation analysis (NAA). These phosphogypsum piles present a potential threat to the surrounding environment and to the individual occupationally exposed. The results obtained in this study show that radionuclides, although present in relatively high concentrations in phosphogypsum, do not imply in significant doses for individuals occupationally exposed. The results obtained for the water activity in the monitor wells showed that the run-off of the piles is influenced by the activity present in the piles, giving indication of a possible groundwater contamination. Sediments from rivers in the area of influence of the pile presented higher concentrations of 238U and 232Th when compared with reference values.