Protonation structure of the photosynthetic water oxidizing complex in the S0 state as revealed by normal mode analysis using quantum mechanics/molecular mechanics calculations.

Photosynthetic water oxidation takes place through the light-driven cycle of five intermediates (S0-S4) of the water oxidizing complex (WOC), which consists of the Mn4CaO5 cluster and surrounding amino acid residues in photosystem II. Clarifying the protonation structures of the Mn4CaO5 cluster and its water ligands (W1-W4) is essential for understanding the molecular mechanism of water oxidation. Here, we performed normal mode analysis of WOC in the S0 and S1 states using quantum mechanics/molecular mechanics calculations and simulated an S1-minus-S0 infrared difference spectrum focusing on the symmetric COO- stretching (νsCOO-) region. The calculated spectrum by an S0 model, in which O4 of the Mn4CaO5 cluster is protonated and W2 is H2O, and a corresponding S1 state with deprotonated O4 best reproduced the νsCOO- features of the experimental spectrum, whereas models with protonated O5 showed poor agreement. In addition, comparison of the calculated coordination distances of the water ligands with the experimental data by X-ray diffraction analysis indicates that W2 is most probably not OH- but H2O both in the S0 and S1 states. The present calculations thus strongly suggest that the S0 state has a protonation structure of O4-H and W2 = H2O. The O4-H structure in the S0 state supports the view that this proton is released through the O4-water chain immediately after electron transfer during the S0→ S1 transition.

Monthly oral ibandronate 100 mg is as effective as monthly intravenous ibandronate 1 mg in patients with various pathologies in the MOVEST study.

The non-inferiority of oral ibandronate 100 mg to intravenous (i.v.) ibandronate 1 mg in increasing lumbar spine (LS) bone mineral density (BMD) after 12 months of treatment was demonstrated in the randomized, phase III MOVEST study. We conducted subgroup analyses in the per-protocol set of the study (n = 183 oral ibandronate; n = 189 i.v. ibandronate). In patients with LS BMD T score ≥ -3.0 or < -3.0 at screening, LS BMD gains from baseline were 4.42 and 5.79%, respectively, with oral ibandronate, and 4.60 and 5.83%, respectively, with i.v. ibandronate. LS BMD gains in patients with or without prevalent vertebral fractures were 5.21 and 5.23%, respectively, with oral ibandronate, and 5.01 and 5.49%, respectively, with i.v. ibandronate. In patients aged <75 or ≥75 years, LS BMD gains were 5.46 and 4.51%, respectively, with oral ibandronate, and 5.25 and 5.77%, respectively, with i.v. ibandronate. LS BMD gains in patients with baseline 25-hydroxyvitamin D levels ≥20 or <20 ng/mL were 5.35 and 4.76%, respectively, with oral ibandronate, and 5.05 and 6.57%, respectively, with i.v. ibandronate. Similar results were obtained in patients with or without prior bisphosphonate (BP) treatment, and in those receiving osteoporosis drug treatment other than BPs. In conclusion, oral ibandronate 100 mg demonstrated comparable BMD gains with monthly i.v. ibandronate, and thus shows high utility in the lifestyle and disease conditions associated with osteoporosis in Japanese patients.

Higher response with bone mineral density increase with monthly injectable ibandronate 1 mg compared with oral risedronate in the MOVER study.

We examined response to bone mineral density (BMD) gains in the MOVER study following treatment with intravenous (IV) ibandronate 1 mg/month, and investigated the characteristics of a non-responder group. At 1 year, responder rates for patients with BMD increases >0 % were similar with IV ibandronate 0.5 or 1 mg/month and oral risedronate 2.5 mg/day. However, after 3 years, responder rates with BMD increases ≥3 % were highest with ibandronate 1 mg at all bone sites (>80 % at the lumbar spine [L2-L4] and >50 % at all femur sites, which was significantly higher than with risedronate). Non-responders were defined by BMD increases ≤3 % at L2-L4 or ≤0 % at total hip, and ≤50 % reduction in creatinine-corrected urinary collagen type 1 cross-linked C-telopeptide (uCTX) from baseline to 1 year. There were a small number of non-responders in the ibandronate 1 mg group: 3.3 % (10/299) with ≤0 % total hip BMD increase and ≤50 % uCTX reduction from baseline. These non-responders had lower 25-hydroxyvitamin D (25[OH]D) levels than responders, but no differences in kidney function, L2-L4 BMD or bone turnover marker baseline values. Throughout the study, non-responders failed to show any increases in BMD. Our analysis demonstrates significantly higher responder rates with IV ibandronate 1 mg/month than with risedronate at 3 years. A small number of non-responders in the ibandronate group had lower 25(OH)D baseline levels than responders, suggesting that 25(OH)D levels could be a useful indicator of BMD response to therapy.

Difficulty for consumers in choosing commercial bilberry supplements by relying only on product label information.

BACKGROUND: Various kinds of bilberry supplements have recently become available on the market. However, it is doubtful whether consumers receive accurate information to be able to compare different supplements. OBJECTIVE: We aimed to investigate whether consumers can obtain the expected benefits by relying only on the information printed on the product labels of commercial bilberry supplements. MATERIALS AND METHODS: The quality of 20 supplements was investigated by the spectrophotometric method and ultra high performance liquid chromatography (UHPLC). Each peak was identified by liquid chromatography-mass spectrometry and quantified using an external standard. The percentage of the actual measured value relative to the indicated value on the product label was determined using the spectrophotometric method. The daily dosage was calculated from the total amount of anthocyanins quantified by UHPLC and information on the product label. RESULTS: In 14 of 20 supplements, the total anthocyanin content expressed as delphinidin equivalents was within 20% of the labeled value. However, the extent of degradation could not be determined by the spectrophotometric method. In fresh bilberry fruit, anthocyanidins were barely detected. In 8 of 20 supplements, the anthocyanidin content was >1.0%. The daily dosage of anthocyanins varied by about 66-fold among supplements, and the dosage of 6 supplements was less than the recommended level in Japan. CONCLUSIONS: Consumers cannot always obtain the expected benefits by relying only on product label information. Therefore, new rules concerning product label information are required to make it possible for consumers to take the equivalent amounts of anthocyanins for whichever bilberry supplement they choose.

Degradation Index for quality evaluation of commercial dietary supplements of bilberry extract.

In recent years, many anthocyanin-containing dietary supplements of various dosages and formulations have been sold through advertising their large number of beneficial effects. On the other hand, there is an increased risk of distributing deteriorated supplements to consumers due to lax regulations, because in Japan these supplements are classified as food. Spectrophotometric methods are commonly used to control the quality of supplements. However, these methods have limitations with regard to assessing deterioration. In this study, we evaluated a new index for detection of deteriorated products. The stability of 3 formulations and the quality of 20 supplements were investigated by ultra-high performance liquid chromatography, which is superior to spectrophotometry for identifying and quantifying individual anthocyanins. The stability was not only affected by storage temperature but also by formulation. We defined "Degradation Index" (DI) as an indicator of the deterioration of supplements. Of 20 supplements investigated, the DI of 5 supplements was more than 3-fold the value of Bilberon-25, and the worst one was 12.7-fold. These results suggest that DI could be a useful quality control index for detecting deteriorated supplements.

Anthocyanins, but not anthocyanidins, from bilberry (Vaccinium myrtillus L.) alleviate pruritus via inhibition of mast cell degranulation.

We have previously reported that bilberry anthocyanins exhibit an anti-pruritic effect in a mouse model of allergic contact dermatitis. It has been reported that anthocyanins are particularly sensitive to thermal treatment and are easily hydrolyzed to anthocyanidins when exposed to high temperatures. The objective of this study was to compare the anti-pruritic effect of anthocyanin-rich quality-controlled bilberry extract and anthocyanidin-rich degraded extract using a mouse model of allergic contact dermatitis. BALB/c mice with allergic contact dermatitis induced by 4 weeks of repeated application of 2,4,6-trinitro-1-chlorobenzene (TNCB) were administered Bilberon-25 orally for 4 weeks after sensitization with TNCB. The effect of Bilberon-25 on pruritus was evaluated by measurement of scratching behavior. RBL-2H3 mast cells were used to investigate the effect of Bilberon-25 on degranulation in 48/80-stimulated mast cells. Compared with nonheated Bilberon-25, the proportion of anthocyanins in heated Bilberon-25 decreased, and the proportion of anthocyanidins was increased in heated-time dependent manner. Treatment with non-heated Bilberon-25 significantly attenuated the TNCB-induced increase in scratching behavior, whereas treatment with 2 h-heated Bilberon-25 did not. Moreover, 300 µg/mL nonheated Bilberon-25 showed significant inhibition of degranulation in RBL-2H3 mast cells, whereas 2 h-heated Bilberon-25 had no effect at any concentration studied. It is assumed that the inhibitory effect of bilberry anthocyanins on pruritus might be mediated, at least in part, by its inhibitory effect on mast cell degranulation. In conclusion, the anthocyanin-rich but not anthocyanidin-rich bilberry extract may be a useful dietary supplement for skin diseases involving pruritic symptoms, such as chronic allergic contact dermatitis, atopic dermatitis, and rhinitis.

Preservation of functional architecture in visual cortex of cats with experimentally induced hydrocephalus.

We investigated how neural function is preserved or matured in the visual cortex of cats, following the induction of hydrocephalus by kaolin injection. In vivo optical imaging of intrinsic signals in 11-17-week-old hydrocephalic cats revealed orientation maps showing the orderly arrangement of preferred orientations when stimulated by grating stimuli at a low spatial frequency, whereas stimulus-evoked intrinsic signals in response to gratings at a high spatial frequency were often too weak to construct orientation maps. Furthermore, in two of the three hydrocephalic cats, initially deteriorated orientation maps became almost regular maps in the second imaging experiments conducted 8 and 11 weeks, respectively, after the first imaging. This indicates that, despite large structural deformation of the hydrocephalic brain, orientation maps are elaborated sufficiently after the age of 5-6 months, by which time the orientation map formation is usually completed in normal cats. Single unit recording from the decompressed visual cortex revealed that many neurons showed normal orientation selectivity, whereas the binocularity of these neurons was found to be reduced. These results suggested that the deformed visual cortex of hydrocephalic cats exhibits a high plasticity, retaining its functional organization.

Xanthocillins as thrombopoietin mimetic small molecules.

Four xanthocillins (1-4), including a new compound 4, were isolated from cultured marine fungus Basipetospora sp. as thrombopoietin (TPO) mimics. Compounds 1-4 promoted the proliferation of a TPO-sensitive human leukemia cell line, UT-7/TPO, and UT-7/EPO-mpl, genetically engineered to express c-Mpl, a receptor for TPO in dose-dependent manners. However, the proliferation of UT-7/EPO, a parental cell line of UT-7/EPO-mpl that was devoid of TPO receptor, was not affected by them. Thrombopoietic action of compound 1 was nearly as potent as that of TPO, inducing cell proliferation at a concentration ranging from 1 to 100nM. Compound 1 also induced the phosphorylation of several proteins, including Janus kinase 2 (Jak2), signal transducers, and activators of transcription-3 (STAT3) and STAT5 in the UT-7/EPO-mpl cell line, but not in the UT-7/EPO cell line. These data indicated that xanthocillins are putative agonists for c-Mpl, as their cellular actions were analogous to those of TPO.

Effect of glucose on intercellular junctions of cultured human peritoneal mesothelial cells.

During continuous ambulatory peritoneal dialysis, the peritoneum is directly and continuously exposed to unphysiologic peritoneal dialysis fluid; the resulting mesothelial damage has been suggested to cause loss of ultrafiltration and dialysis efficacy. The present study investigated the effect of a high glucose concentration on cultured human peritoneal mesothelial cells to clarify the cause of decreased dialysis efficacy during prolonged peritoneal dialysis. High glucose caused a concentration-dependent decrease in cell proliferation, damage to the intercellular junctions, and excess production of transforming growth factor-beta (TGF-beta). The levels of intercellular junctional proteins (ZO-1, E-cadherin, and beta-catenin) were decreased, and immuno-staining by anti-ZO-1 and anti- beta-catenin antibodies became weaker and often discontinuous along the cell contour. Mannitol had similar but weaker effects at the same osmolality, and an anti-TGF-beta neutralizing antibody reduced the effects of high glucose. Therefore, these effects were induced not only by glucose itself but also by hyperosmolality and by a glucose-induced increase of TGF-beta. These findings suggest that the peritoneal mesothelium is damaged by prolonged peritoneal dialysis using high glucose dialysate and that impairment of the intercellular junctions of peritoneal mesothelial cells by high glucose dialysate induces peritoneal hyperpermeability and a progressive reduction in dialysis efficacy.