Difference of high-light stress sensitivity in the two firs, Abies mariesii and Abies veitchii, in early spring

Abies veitchii and Abies mariesii are dominant species at the tree-line in Central Japan. Recently, we observed needle death, probably due to photodamage of the photosynthetic apparatus at the tree-limit during March-April. A. veitchii survives winter without any needle death due to photodamage at the tree-line. However, there is no conspicuous damage between the two species because this phenomenon is only observed at the tree-limit. In this study, we examined the difference in winter down-regulation of PS II between A. veitchii and A. mariesii and observed the following results: In March, (1) Fv/Fm of both species was about 0.1, showing the photochemical efficiency being severely inhibited. (2) The de-epoxidation state, expressed as [(A+Z)/(V+A+Z)], was about 0.35 for both species. (3) Chlorophyll (Chl) content of A. veitchii was much less than that of A. mariesii and Pchlide was found only in A. veitchii. In April, (1) Fv/Fm increased and [(A+Z)/(V+A+Z)] decreased for both species. (2) Chl content of A. veitchii increased by four-fold while Pchlide nearly dissappeared. These results indicate the following: During cold periods, most of Chl of A. veitchii may have been converted to Pchlide which is easily re-converted to Chl in spring, an intermediate of Chl biosynthesis. Winter conversion from Chl to Pchlide in A. veitchii may provide effective protection from photodamage of the photosynthetic apparatus. Furthermore, this may explain the higher ability of A. veitchii to prevent photodamage compared to A. mariesii

clinically amyopathic dermatomyositis の有用な予後予測因子としての血清 IL-6 値

Objectives Clinically amyopathic dermatomyositis (CADM) is considered as the subtype of dermatomyositis with amyopathy or hypomyopathy. Rapidly progressive interstitial lung disease (RP-ILD) is treatment-resistant and life-threatening in patients with CADM. Since useful markers for early diagnosis are necessary for early treatment in CADM patients with RP-IPD, this study aimed to investigate the differences of clinical and laboratory characteristics between alive patients (group A) and patients who died (group D).Methods Eleven patients with CADM complicating with RP-ILD were enrolled. Clinical manifestations and laboratory data before treatment were compared between group A and group D.Results Among them, six were alive and five died after treatment for RP-ILD. Serum IL-6 levels in group D were significantly higher than those in group A (median 19.7 vs 7.15 pg/ml; P=0.008). The stepwise regression analysis showed that IL-6 was the only prognostic factor significantly (p=0.035). Kaplan-Meier estimates showed that patient survivals were better in patients with IL-6 9pg/ml (p=0.039). Other laboratory data were not different statistically between two groups.Conclusions Serum IL-6 may predict the prognosis of patients with CADM having RP-ILD. Patients with IL-6 >9pg/ml should be treated by the more aggressive immunosuppressive therapy