Cellular Mycosporine-like amino acids protect photosystem II of the Dinoflagellate Scrippsiella sweeneyae from ultraviolet radiation damage.

Photo-damage to photosystem II (PSII) from ultraviolet radiation (UVR) was determined using chlorophyll fluorescence in relation to sunscreen factors on the dinoflagellate Scrippsiella sweeneyae based on the cellular mycosporine-like amino acid contents (CMAAs, cell) and cell diameter (=light path, d). Three different CMAAs, cell were prepared by acclimating cells to three levels (30.8, 15.2, and 7.7Wm-2) of photosynthetically active radiation (PAR). PAR-acclimated cells were exposed to PAR (0.64Wm-2)+UVR (3.94W m-2=2.51Wm-2 UVB+1.43Wm-2 UVA) for 12min. High PAR (HL) and medium PAR (NDF1) treatments acclimated cells to induce shinorine and porphyra-334 (longer λmax at 333 and 334nm); whereas, the low PAR (NDF2) treatment acclimated cells to induce mycosporine-glycine and palythine (shorter λmax at 310 and 320nm). Absorption spectra for the individual MAAs were reconstructed using the λmax and CMAAs, cell and were summed to reconstruct the absorption of the total CMAAs, cell (m2cell-1) to estimate the sunscreen factor (S[λ]) at λmax. The highest S(λmax) was obtained for cells that acclimated to the highest PAR (highest CMAAs, cell and longest d); whereas, the lowest S(λmax) was obtained for cells acclimated to the lowest PAR (the lowest CMAAs, cell and the shortest d). CMAAs, cell contributed approximately 94%, whereas d contributed <6%, of the sunscreen factor (Sλmax). UVR-induced damage was indexed with a temporal decrease in the optimum quantum yield (Fv/Fm) in the Photosystem II. The highest damage was observed for cells acclimated to the lowest Sλmax (lowest CMAAs, cell and shortest d); whereas, the lowest damage was observed for cells acclimated to the highest Sλmax (highest CMAAs, cell and longest d). The CMAAs, cell mitigated most of the UVR-induced damage in photosystem II of the dinoflagellate S. sweeneyae.

[Improved care of foot ulcer using foot pressure measurement and foot care method sheet].

At this sanatorium, the number of foot bottom ulcer patients was 13 and the tenure of the foot bottom ulcer was average 11 years. According to the treatment that was not unified, we thought about the cause of the prolongation. Therefore, we made evaluation and care method sheet ("foot care sheet") of the ulcer for the unification. We used the foot pressure measurement system (F-scan) to 4 patients for the pressure dispersion of the ulcer. We devised the protection law of the ulcer, and an ulcer did not require pressure more than 5 kilos/cm2. We recorded the size of the ulcer, weight of the liquid from ulcer, a photograph to care sheet once a week. I performed ulcer protection law and management with the foot care sheet to 4 patients for average 4 months. As a result, the ulcers of 3 patients out of 4 patients became small.

Daily variation in cellular content of UV-absorbing compounds mycosporine-like amino acids in the marine dinoflagellate Scrippsiella sweeneyae.

Sudden exposure experiments to high PAR (photosynthetically available radiation) or high PAR+UVR (ultraviolet radiation) were conducted for the marine dinoflagellate Scrippsiella sweeneyae acclimated to either low PAR or high PAR to determine the induction of cellular mycosporine-like amino acid (MAA) in relation to photosynthesis status. When the exposure to high PAR (30.8 Wm(-2)) was provided at different time in the light period for S. sweeneyae acclimated to low PAR (7.7 Wm(-2)) which suppressed photosynthesis, S. sweeneyae could enhance the induction of MAA but it only occurred in the first half of the light period. When UVR exposure was provided for the culture acclimated to high PAR which enhanced photosynthesis, cellular MAA content did not increase during the entire light period, but displayed daily variation similar to the control for two and half days. Daily variation of cellular MAA content did not synchronized with that of cell volume and cellular chlorophyll a content. The individual MAAs also revealed similar daily variations with different phase, which increased for a few hours in the beginning of the light period, except for cellular palythine content. Thus the total cellular MAA content revealed daily variation with changing the relative composition within a few hours. As one of the biological protective strategies against harmful UVR in sunlight, the daily vertical migration in the bloom forming dinoflagellates might be accompanied by the daily variation of cellular MAA content for a photosynthesis at daytime.