Growth-phase dependent variation in photosynthetic activity and cellular protein expression profile in the harmful raphidophyte Chattonella antiqua.

This study investigated temporal variations in the potential maximum quantum yield of photosystem II (F(v)/F(m) ratio) and growth-phase dependent cellular protein expressions of Chattonella antiqua under laboratory conditions. Despite the culture conditions, significant positive correlations between the F(v)/F(m) ratio and daily growth rate were observed. Threshold F(v)/F(m) ratios associated with positive cell growth were calculated to be >0.44, >0.44, and >0.37, and those associated with active cell growth (growth rate >0.5 div. d(-1)) were >0.58, >0.60, and >0.49 under control culture, low nutrient and intense light conditions, respectively. Proteome profiles obtained by two-dimensional gel electrophoresis (2-DE) indicated that 42 protein spots were differentially expressed at various growth phases of C. antiqua, which indicates changes in cellular physiological status throughout the growth cycle, and suggests that oxygen evolving enhancer 1 and 2-cysteine peroxiredoxin play roles in maintaining the positive growth of C. antiqua.

Spatio-temporal variations in bloom of the red-tide dinoflagellate Karenia mikimotoi in Imari Bay, Japan, in 2014: Factors controlling horizontal and vertical distribution.

A massive bloom of the dinoflagellate Karenia mikimotoi appeared in 2014 in Imari Bay, Japan. Bloom dynamics and hydrographical conditions were examined by field survey. The bloom initially developed in the eastern area of Imari Bay, subsequently after rainfall during the neap tides, cell density exceeded over 10,000cellsml. Vertical distribution of K. mikimotoi was primarily controlled by the light intensity and secondarily by the water quality during the daytime. Almost all cell-density maxima occurred in depths with weak daytime light intensities of <300µmolm-2s-1. In some cases of weak light intensity, cell-density maxima occurred in depths with favorable hydrodynamic conditions for the growth. Spatially classified areas were identified by cluster analysis using the growth rate calculated from seawater temperature and salinity. This study quantitatively evaluated the environmental factors of the eastern area, where the bloom initially occurred, during the development of the bloom.

[Effects of pesticides on cytokines production by human peripheral blood mononuclear cells--fenitrothion and glyphosate].

In patients with pesticides poisoning, human immune system seems to be damaged. However, the effects of pesticides on human immune system, especially on cytokines production, have not been understood well. We investigated the effects of fenitrothion (MEP), an organophosphorus insecticide, and glyphosate (GLP), a phosphorus containing amino acid-type herbicide, on cytokines production by human peripheral blood mononuclear cells (PBMC). MEP inhibited the proliferative activity of PBMC at ranging from 1 to 500 microM in a concentration-dependent manner, whereas GLP had a slight inhibitory effect even at 1000 microM. The production of IFN-gamma and IL-2 was inhibited by MEP in a concentration-dependent manner, but GLP slightly inhibited their production only at 1000 microM. The production of TNF-alpha and IL-1 beta was not affected by MEP and GLP at the concentrations which significantly inhibited the proliferative activity and T cell-derived cytokine production. MEP inhibited the production of T cell-derived cytokine (IFN-gamma and IL-2), which indicates that MEP might have the potential of immunosuppressive action. On the other hand, GLP might be a pesticide with only a little damage to the immune system, according to the results in cytokines production. These results suggest that pesticides inhibit the immune system differently, and the grasp of immune condition might be useful for the prognostic presumption and the infectious danger of degree in patients with pesticides poisoning.

Increased in vitro release of interferon-gamma from ampicillin-stimulated peripheral blood mononuclear cells in Stevens-Johnson syndrome.

Stevens-Johnson syndrome (SJS) was diagnosed in a 39-year-old woman, treated with ampicillin (4000-8000 mg daily), phenytoin (250 mg daily), and furosemide (20-40 mg daily) for 25, 21, and 20 d, respectively, before the appearance of the eruption. The lymphocyte stimulation test with the MTT [3-(4,5-dimethyl thiazol-2-yl)-2,5-diphenyl tetrazolium bromide] assay on ampicillin, phenytoin, and furosemide showed a low value of stimulation index, which indicated negative reactivity. An in vitro IFN-gamma release test was conducted on the patient with SJS and on two healthy controls. IFN-gamma release increased by 52% following the in vitro challenge of the patient's peripheral blood mononuclear cells (PBMCs) with 15 microg/ml of ampicillin, but not with phenytoin or furosemide. Neither of the controls experienced increased IFN-gamma release. In the present case, increased in vitro IFN-gamma release was observed on ampicillin-stimulated PBMCs, which may indicate the role of ampicillin as the drug responsible for the induction of SJS, and may imply the role of IFN-gamma in the pathogenesis of SJS.