Reaction of α-Tocopherol with 2,2′-Azobis(2,4-dimethyIvaleronitrile) in Benzene

α-Tocopherol was reacted with an alkylperoxyl radical at 37°C in benzene. 2,2′-Azobis(2,4- dimethylvaleronitrile) was used to generate the alkylperoxyl radicals. The reaction products of α- tocopherol were isolated by reverse-phase and normal-phase high performance liquid chromatography, and their structures were characterized. They were four stereoisomers of 8a-(l-cyano-l,3- dimethyl)butylperoxy-α-tocopherone, spirodiene dimer and two geometrical isomers of the trimer. When α-tocopherol at a low concentration was reacted with AMVN, the major products were 8a- alkylperoxy-α-tocopherones. On the other hand, the products of the alkylperoxyl radical with α- tocopherol at a high concentration were spirodiene dimer and trimer in addition to the 8a-alkylperoxy- α-tocopherones.     

Overexpression of Catalase Diminishes Oxidative Cysteine Modifications of Cardiac Proteins

Reactive protein cysteine thiolates are instrumental in redox regulation. Oxidants, such as hydrogen peroxide (H₂O₂), react with thiolates to form oxidative post-translational modifications, enabling physiological redox signaling. Cardiac disease and aging are associated with oxidative stress which can impair redox signaling by altering essential cysteine thiolates. We previously found that cardiac-specific overexpression of catalase (Cat), an enzyme that detoxifies excess H₂O₂, protected from oxidative stress and delayed cardiac aging in mice. Using redox proteomics and systems biology, we sought to identify the cysteines that could play a key role in cardiac disease and aging. With a ‘Tandem Mass Tag’ (TMT) labeling strategy and mass spectrometry, we investigated differential reversible cysteine oxidation in the cardiac proteome of wild type and Cat transgenic (Tg) mice. Reversible cysteine oxidation was measured as thiol occupancy, the ratio of total available versus reversibly oxidized cysteine thiols. Catalase overexpression globally decreased thiol occupancy by ≥1.3 fold in 82 proteins, including numerous mitochondrial and contractile proteins. Systems biology analysis assigned the majority of proteins with differentially modified thiols in Cat Tg mice to pathways of aging and cardiac disease, including cellular stress response, proteostasis, and apoptosis. In addition, Cat Tg mice exhibited diminished protein glutathione adducts and decreased H₂O₂ production from mitochondrial complex I and II, suggesting improved function of cardiac mitochondria. In conclusion, our data suggest that catalase may alleviate cardiac disease and aging by moderating global protein cysteine thiol oxidation.     

New Species of Boletellus Section Boletellus (Boletaceae,Boletales) from Japan,B. aurocontextus sp. nov. and B. areolatus sp. nov.

We describe and illustrate two new species of Boletellus section Boletellus, B. aurocontextus sp. nov. and B. areolatus sp. nov., which are generally assumed to be B. emodensis. In this study, we reconstructed separate molecular phylogenetic trees of section Boletellus using the nucleotide sequences of the internal transcribed spacer (ITS) region of nuclear ribosomal DNA, the largest subunit (RPB1) and the second-largest subunit (RPB2) of nuclear RNA polymerase II gene and mitochondrial cytochrome oxidase subunit 3 (cox3) gene. We also examined the morphologies of B. emodensis sensu lato (s.l.) and other related species for comparison. The molecular phylogenetic tree inferred from the sequences of nuclear DNA (ITS, and combined dataset of RPB1 and RPB2) indicated that three genetically and phylogenetically well-separated lineages were present within B. emodensis s.l. These three lineages were also distinguished on the basis of the molecular phylogenetic tree constructed using the sequences of mitochondrial DNA (cox3), suggesting distinct cytonuclear disequilibria (i.e., evidence of reproductive isolation) among these lineages. Therefore, these three lineages can be treated as independent species: B. aurocontextus, B. areolatus, and B. emodensis. Boletellus aurocontextus and B. areolatus are also distinct from B. emodensis by the macro- and microscopic morphologies. Boletellus aurocontextus is characterized by a pileus with bright yellow to lemon yellow context, which can be observed through a gap in the scales, and basidiospores with relatively large length (mean spore length, 21.4 μm; quotient of spore length and width, 2.51). In contrast, B. areolatus is characterized by a pileus with floccose to appressed thin scaly patches, a stipe with pallid or pale cream color at the upper half, and basidiospores with relatively small length (mean spore length, 16.5 μm; quotient of spore length and width, 1.80).     

Spatial Segregation and Aggregation of Ectomycorrhizal and Root-Endophytic Fungi in the Seedlings of Two Quercus Species

Diverse clades of mycorrhizal and endophytic fungi are potentially involved in competitive or facilitative interactions within host-plant roots. We investigated the potential consequences of these ecological interactions on the assembly process of root-associated fungi by examining the co-occurrence of pairs of fungi in host-plant individuals. Based on massively-parallel pyrosequencing, we analyzed the root-associated fungal community composition for each of the 249 Quercus serrata and 188 Quercus glauca seedlings sampled in a warm-temperate secondary forest in Japan. Pairs of fungi that co-occurred more or less often than expected by chance were identified based on randomization tests. The pyrosequencing analysis revealed that not only ectomycorrhizal fungi but also endophytic fungi were common in the root-associated fungal community. Intriguingly, specific pairs of these ectomycorrhizal and endophytic fungi showed spatially aggregated patterns, suggesting the existence of facilitative interactions between fungi in different functional groups. Due to the large number of fungal pairs examined, many of the observed aggregated/segregated patterns with very low P values (e.g., < 0.005) turned non-significant after the application of a multiple comparison method. However, our overall results imply that the community structures of ectomycorrhizal and endophytic fungi could influence each other through interspecific competitive/facilitative interactions in root. To test the potential of host-plants'' control of fungus–fungus ecological interactions in roots, we further examined whether the aggregated/segregated patterns could vary depending on the identity of host plant species. Potentially due to the physiological properties shared between the congeneric host plant species, the sign of hosts'' control was not detected in the present study. The pyrosequencing-based randomization analyses shown in this study provide a platform of the high-throughput investigation of fungus–fungus interactions in plant root systems.     

A Prospective Stratified Case-Cohort Study on Statins and Multiple Adverse Events in Japan

Purpose

To assess the association between statins and diverse adverse events in Japanese population.

Methods

New users of statin who started statin after 6-month period of non-use were identified in 68 hospitals between January 2008 and July 2010. In addition to the random sample subcohort, we selected additional subcohort members to make the stratified sample subcohort have at least one patient in all subgroups stratified by each combination of statin and hospital. By abstraction from medical records, detailed information was obtained for all potential cases and pre-selected subcohort members. The event review committee consisting of 3 specialists judged whether possible cases met the definition of one of the adverse events of interest, and for adjudicated cases the committee further judged whether statin was a certain, probable or possible cause of the occurrence of the event. Adjusted for covariates including age, gender, status of “switcher”, use of high daily dose and comorbidities at baseline, hazard ratio (HR) was estimated by the Cox proportional hazards model with Barlow’s weighting method. Data were also analyzed by the method proposed by Breslow in 2009.

Results

A total of 6,877 new users of a statin were identified (median age: 66 years; males: 52%). The hazard ratios of increase in serum creatinine for atorvastatin and fluvastatin have wide confidence intervals, but both of the point estimates were around 2.5. Estimates of hazard ratios by the method of Barlow (1999) were similar to those by the method of Breslow (2009).

Conclusions

Use of statin was not associated with a significant increased risk for renal, liver and muscle events. However, the hazard ratio of increase in serum creatinine tended to be high with atorvastatin and fluvastatin to require further studies.