Time-resolved IR spectra indicated fast electron transfer from the reduced photosensitizer to the catalyst.

SUMMARYIn Arabidopsis, three receptors exist for the phytohormone gibberellin. Of the three, only a double loss-offunction mutant (atgid1a atgid1c) shows a dwarf phenotype, while other double and all single mutants show no abnormality in height. In this study we show that the expression of AtGID1b-GUS mRNA, driven by the AtGID1b promoter, is low in inflorescence stems, but may be 10% of AtGID1a-GUS mRNA, driven by the AtGID1a promoter. However, AtGID1b-GUS enzymatic activity does not exist in them. This factor strongly suggests that atgid1a atgid1c lacks sufficient AtGID1b protein for normal stem growth. In the stamens of pAtGID1c::AtGID1c-GUS transformants, we detected clear AtGID1c-GUS activity, while another atgid1a atgid1b, which has short stamens in its flowers, causes the adhesion of little pollen to stigmas thus leading to its low fertility. We then evaluated the affinity of the AtGID1-DELLA interaction by a competitive yeast threehybrid system and also by QCM apparatus. AtGID1c showed a quite lower affinity to RGL2, the major DELLA protein in floral buds, than AtGID1a or AtGID1b. The low affinity of the AtGID1c-RGL2 interaction is likely to be responsible for the failure of AtGID1c to hold RGL2, which is required for normal stamen development. Taken together with expressional information of DELLA genes, we propose that in a double loss-of-function mutant of gibberellin receptors, the emergence of any phenotype(s) depends on the abundance of the remaining receptor and its preference to DELLA proteins existing at a target site.

The abnormal aggregation of amyloid β-protein (Aβ) is considered central in the pathogenesis of Alzheimer’s disease. We focused on membrane-mediated amyloidogenesis and found that amyloid fibrils formed on monosialoganglioside GM1 clusters were more toxic than those formed in aqueous solution. In this study, we investigated the structure of the toxic fibrils by Aβ-(1–40) in detail in comparison with less-toxic fibrils formed in aqueous solution. The less-toxic fibrils contain in-resister parallel β-sheets, whereas the structure of the toxic fibrils is unknown. Atomic force microscopy revealed that the toxic fibrils had a flat, tape-like morphology composed of a single β-sheet layer. Isotope-edited infrared spectroscopy indicated that almost the entire sequence of Aβ is included in the β-sheet. Chemical cross-linking experiments using Cys-substituted Aβs suggested that the fibrils mainly contained both in-resister parallel and two-residue-shifted antiparallel β-sheet structures. Solid-state NMR experiments also supported this conclusion. Thus, the toxic fibrils were found to possess a novel unique structure.

No clinical evidence on the efficacy and safety of eribulin monotherapy has been obtained by a prospective clinical study in patients with metastatic breast cancer (MBC) who had well-defined taxane resistance. The present Phase II, multicenter, single-arm, open-label study aimed to obtain the evidence. Japanese female patients, aged 33–74 years who had the metastasis of taxane-resistant and histopathologically confirmed breast cancer, received eribulin mesylate 1.4 mg/m2 (equivalent to eribulin 1.23 mg/m2 [expressed as free base]) as a 2- to 5-min intravenous infusion on days 1 and 8 of each 21-day cycle. The primary endpoint was the clinical benefit rate (CBR) [complete response (CR), partial response (PR), and long-term stable disease (LSD) ≥24 weeks]. A total of 51 patients underwent chemotherapy cycles (median 4; range 1–42 cycles). The CBR was 39.2 % (CR 2.0 %; PR 23.5 %; and LSD 13.7 %), and the rate of progressive disease was 49.0 %. The median progression-free survival and the median overall survival were 3.6 months [95 % confidence interval (CI) 2.6–4.6 months] and 11.7 months (95 % CI 9.2–14.2 months), respectively. Grade 3 or greater adverse events were leukopenia (23.5 %), neutropenia (35.3 %), anemia (5.9 %), and febrile neutropenia (7.8 %). The incidences of grade 3 and 4 peripheral sensory neuropathy were 2.0 and 0 %, respectively. Eribulin showed a clinically manageable tolerability profile by dose adjustments or symptomatic treatment. Eribulin was effective and well tolerated in heavily pretreated patients with MBC who had well-defined taxane resistance, thus providing a potential therapeutic option in the clinical settings.