Sleep-related factors associated with industrial accidents among factory workers and sleep hygiene education intervention

Sleep and Biological Rhythms - This study was conducted to investigate the association between industrial accidents and sleep-related parameters in factory workers, and to examine the effectiveness...     

Consequences of Sphaeropsis tip blight disease for the phytohormone profile and antioxidative metabolism of its pine host

Phytopathogenic fungi infections induce plant defence responses that mediate changes in metabolic and signalling processes with severe consequences for plant growth and development. Sphaeropsis tip blight, induced by the endophytic fungus Sphaeropsis sapinea that spreads from stem tissues to the needles, is the most widespread disease of conifer forests causing dramatic economic losses. However, metabolic consequences of this disease on bark and wood tissues of its host are largely unexplored. Here, we show that diseased host pines experience tissue dehydration in both bark and wood. Increased cytokinin and declined indole‐3‐acetic acid levels were observed in both tissues and increased jasmonic acid and abscisic acid levels exclusively in the wood. Increased lignin contents at the expense of holo‐cellulose with declined structural biomass of the wood reflect cell wall fortification by S. sapinea infection. These changes are consistent with H₂O₂ accumulation in the wood, required for lignin polymerization. Accumulation of H₂O₂ was associated with more oxidized redox states of glutathione and ascorbate pools. These findings indicate that S. sapinea affects both phytohormone signalling and the antioxidative defence system in stem tissues of its pine host during the infection process.     

Enhanced Protection Against Peroxidation-Induced Mortality of Aortic Endothelial Cells by Ascorbic Acid-2-O-Phosphate Abundantly Accumulated in the Cell as the Dephosphorylated Form

Bovine aortic endothelial BAE-2 cells exposed to the peroxidizing agent, tert-butylhydroperoxide (t-BuOOH) or 2,4-nonadienal (NDE), suffered from disruption of cell membrane integrity and from reduction of mitochondrial dehydrogenase activity as assessed by fluorometry using ethidium homodimer and photometry using WST-1, respectively. The cells were protected from t-BuOOH-induced injury more markedly by L-ascorbic acid-2-O-phosphate (Asc2P) stably masked at the 2,3-enediol moiety, which is responsible for the antioxidant ability of L-ascorbic acid (Asc), than by Asc itself. In contrast, NDE-induced membrane disruption but not mitochondrial dysfunction was prevented by Asc2P, whereas Asc exhibited no prevention against both types of injury. The amount of intracellular Asc was 7.2- to 9.0-fold larger in Asc2P-administered BAE-2 cells, where the intact form Asc2P was not detected, than in Asc-administered cells as assessed by HPLC of cell extract with detection by coulometric ECD and W. During transmembrane influx into the cell, Asc2P was concentrated as highly as 70- to 90-fold relative to the extracellular Asc2P concentration, whereas Asc was 8-to 13-fold concentrated as estimated based on an intracellular water content of 0.59 pL/cell determined by [¹⁴C]PEG/gas chromatography. Thus, Asc2P but not Asc is highly concentrated in the aqueous phase of the cell after prompt dephosphorylation, and may thereby render the cell more resistant to t-BuOOH-peroxidation assumedly via scavenging of intracellular reactive oxygen species than to peroxidation with the less hydroplulic agent NDE.     

Genetic diversity of Couratari multiflora and Couratari guianensis (Lecythidaceae): consequences of two types of rarity in central Amazonia

We quantified the within-population genetic variation of Couratari multiflora and C. guianensis, two tree species found in terra firme forests of central Amazonia. Both species have some ecological features in common, but they differ in population abundance across their geographic ranges. While C. multiflora has been found only in low-density populations in all sites studied to date, C. guianensis is relatively common in some sites and very scarce in others. In a 400-ha plot, we found 41 and 29 adults of C. multiflora and C. guianensis, respectively. Twenty-two saplings of C. guianensis and 103 seedlings of C. multiflora were also examined. The mean expected heterozygosities (H_em) of seedlings and adults of C. multiflora were 0.431 and 0.436, and the mean fixation indices (F_m), 0.114 and 0.176, respectively. For C. guianensis, saplings and adults presented H_em equal to 0.425 and 0.429, and the F_m were 0.393 and 0.527, respectively. These low-density populations of two congeneric species did not differ in terms of genetic diversity, but rather they differed in terms of mean observed heterozygosity (H_om), and therefore F_m. The species with variable population density had lower H_om and greater F_m relative to the species that is always found in low-density.     

Crystal structural characterization reveals novel oligomeric interactions of human voltage‐dependent anion channel 1

Voltage‐dependent anion channel 1 (VDAC1), which is located in the outer mitochondrial membrane, plays important roles in various cellular processes. For example, oligomerization of VDAC1 is involved in the release of cytochrome c to the cytoplasm, leading to apoptosis. However, it is unknown how VDAC1 oligomerization occurs in the membrane. In the present study, we determined high‐resolution crystal structures of oligomeric human VDAC1 (hVDAC1) prepared by using an Escherichia coli cell‐free protein synthesis system, which avoided the need for denaturation and refolding of the protein. Broad‐range screening using a bicelle crystallization method produced crystals in space groups C222 and P22₁2₁, which diffracted to a resolution of 3.10 and 3.15 Å, respectively. Each crystal contained two hVDAC1 protomers in the asymmetric unit. Dimer within the asymmetrical unit of the crystal in space group C222 were oriented parallel, whereas those of the crystal in space group P22₁2₁ were oriented anti‐parallel. From a model of the crystal in space group C222, which we constructed by using crystal symmetry operators, a heptameric structure with eight patterns of interaction between protomers, including hydrophobic interactions with β‐strands, hydrophilic interactions with loop regions, and protein–lipid interactions, was observed. It is possible that by having multiple patterns of interaction, VDAC1 can form homo‐ or hetero‐oligomers not only with other VDAC1 protomers but also with other proteins such as VDAC2, VDAC3 and apoptosis‐regulating proteins in the Bcl‐2 family.     

A Round-bottom 96-well Polystyrene Plate Coated with 2-methacryloyloxyethyl Phosphorylcholine as an Effective Tool for Embryoid Body Formation

In this study, we proposed a culture method for forming embryoid bodies (EBs) from mouse embryonic stem (ES) cells using a round-bottom 96-well polystyrene plate coated with 2-methacryloyloxyethyl phosphorylcholine (MPC plate). MPC is a phospholipid biocompatible polymer and prevents cells from adhering to the culture surface. The ES cells were seeded at 1000 cells per well in the MPC plate with 200 μl of medium. After 5 days of static incubation, a spherical cell aggregate termed EB was formed in a well. The size (diameter) of resulting EB was approximately 550 μm and it contained approx. 22,000 cells. It seems that the non-adhesiveness and the roundness of the well are important factors to form a good EB. Transferring the EBs to the attached differentiation culture, the EBs spread out and flattened, and the beating cells (cardiomyocytes) were effectively generated in the outgrowth of EBs. The round-bottom 96-well polystyrene plate coated with MPC is an effective tool for EB formation.     

Soybean Seed Extracts Preferentially Express Genomic Loci of Bradyrhizobium japonicum in the Initial Interaction with Soybean, Glycine max (L.) Merr

Initial interaction between rhizobia and legumes actually starts via encounters of both partners in the rhizosphere. In this study, the global expression profiles of Bradyrhizobium japonicum USDA 110 in response to soybean (Glycine max) seed extracts (SSE) and genistein, a major soybean-released isoflavone for nod genes induction of B. japonicum, were compared. SSE induced many genomic loci as compared with genistein (5.0 µM), nevertheless SSE-supplemented medium contained 4.7 µM genistein. SSE markedly induced four predominant genomic regions within a large symbiosis island (681 kb), which include tts genes (type III secretion system) and various nod genes. In addition, SSE-treated cells expressed many genomic loci containing genes for polygalacturonase (cell-wall degradation), exopolysaccharide synthesis, 1-aminocyclopropane-1-carboxylate deaminase, ribosome proteins family and energy metabolism even outside symbiosis island. On the other hand, genistein-treated cells exclusively showed one expression cluster including common nod gene operon within symbiosis island and six expression loci including multidrug resistance, which were shared with SSE-treated cells. Twelve putatively regulated genes were indeed validated by quantitative RT-PCR. Several SSE-induced genomic loci likely participate in the initial interaction with legumes. Thus, these results can provide a basic knowledge for screening novel genes relevant to the B. japonicum- soybean symbiosis.Key words: soybean seed extracts, Bradyrhizobium japonicum, expression clusters, genistein, symbiosis