Intervention for regulating sleep–wake rhythms to prevent sleepiness in Japanese train drivers

Sleep and Biological Rhythms - The nocturnal sleep of train drivers is apt to be short and their lifestyle become irregular because they drive at midnight and early in the morning. As a result,...     

Advances in soil microbial ecology and the biodiversity

Recent studies on the colony formation of soil bacteria opened the way to categorize soil bacteria into colony forming curve (CFC) groups of different growth rates. A bacterial culture collection comprising organisms from every CFC group is called an ecocollection. Outlines of ECs of paddy soil 1992 and grassland soil 1987 and 1992 were described. Phylogenetic studies by 16S rDNA sequencing showed a great diversity of culture strains of the ecocollections (EC). A set of alternative concepts was proposed; the active and the quiescent forms of bacterial cells in soil. The former is able to be cultivated and thus counted by the plate method, while the latter is not unless it transforms into the former. Based on the results several points required for extensive cataloguing of soil bacteria were noted.     

Norepinephrine, but not epinephrine, enhances platelet reactivity and coagulation after exercise in humans

The effects of exercise and catecholamineson platelet reactivity or coagulation and fibrinolysis appear to beinconsistent. This may be partly due to the methods employed inprevious studies. In the present study, we investigated the effects ofacute aerobic exercise and catecholamines on the thrombotic status by anovel in vitro method, shear-induced hemostatic plug formation(hemostatometry), using nonanticoagulated (native) blood. Aerobicexercise (60% maximal O₂consumption) was performed by healthy male volunteers for 20 min, andthe effect on platelet reactivity and coagulation was assessed byperforming hemostatometry before and immediately after exercise.Exercise significantly increased shear-induced platelet reactivity,coagulation, and catecholamine levels. The effect of catecholamines onplatelet reactivity and coagulation was assessed in vitro by addingcatecholamines to blood collected in the resting state. The mainfindings of the present study are that elevation of circulatingnorepinephrine at levels that are attained during exercise causesplatelet hyperreactivity and a platelet-mediated enhanced coagulation.This may be a mechanism of an association of aerobic exercise withthrombotic risk.

     

Effects of chronic administration of bilobalide on amino acid levels in mouse brain.

We have previously demonstrated that 4-day-treatment of mice with bilobalide, a sesquiterpene of Ginkgo biloba L., increases GABA levels in mouse brain, but, effects of chronic treatment with it are not clear. To study effects of chronic treatment of mice with bilobalide on amino acid levels in the brain, we determined the levels of aspartate, glutamate, serine, glutamine, glycine, taurine and GABA in the hippocampus, striatum and cortex. Bilobalide (3 mg/kg/day) was administered orally to 4-week-old mice for 40 days. Bilobalide treatment resulted in a significant increase in the levels of glutamate, aspartate, gamma-aminobutyric acid (GABA), and glycine in the hippocampus of mice compared with the control. An increased level of glycine after bilobalide treatment was also detected in the striatum. In the cortex, bilobalide increased the GABA level, whereas it decreased the level of aspartate. These changes in the levels of various amino acids may be involved in the broad spectrum of pharmacological activities of the extract of Ginkgo biloba on the central nervous system.     

Nucleoid Condensation and Cell Division in Escherichia coli MX74T2 ts52 After Inhibition of Protein Synthesis

The reorganization of the bacterial nucleoid of an Escherichia coli mutant, MX74T2 ts52, was studied by electron microscopy after protein synthesis inhibition by using whole mounts of cell ghosts, ultrathin-sectioning, and freeze-etching. The bacterial nucleoid showed two morphological changes after chloramphenicol addition: deoxyribonucleic acid (DNA) localization and DNA condensation. DNA localization was observed 10 min after chloramphenicol addition; the DNA appeared as a compact, solid mass. DNA condensation was observed at 25 min; the nucleoid appeared as a cytoplasm-filled sphere, often opened at one end. Ribosomes were observed in the center. Giant nucleoids present in some mutant filaments showed fused, spherical nucleoids arranged linearly, suggesting that the tertiary structure of the nucleoid reflects the number of replicated genomes. Inhibitors which directly or indirectly blocked protein synthesis and caused DNA condensation were chloramphenicol, puromycin, amino acid starvation, rifampicin, or carbonyl cyanide m-chlorophenyl hydrazone. All inhibitors that caused cell division in the mutant also caused condensation, although some inhibitors caused condensation without cell division. Nucleoid condensation appears to be related to chromosome structure rather than to DNA segregation upon cell division.     

Characterization of the carboxyl terminal-truncated endothelin B receptor coexpressed with G protein-coupled receptor kinase 2.

The role of phosphorylation of the C-terminal tail of endothelin B receptor (ETBR) in agonist-induced desensitization was investigated, using a mutant lacking C-terminal 40 amino acids (delta 40 ETBR). In cells expressing the wild type or delta 40 ETBR, ET-1 caused rapid desensitization of calcium responses. The wild type ETBR was phosphorylated by biotinylated ET-1, and the phosphorylation was markedly enhanced by coexpression with G protein-coupled receptor kinase 2 (GRK2). However, delta 40 ETBR was not phosphorylated regardless of coexpression with GRK2. On the other hand, ET-1-induced IP3 formation in these cells was decreased by coexpression with GRK2 or catalytically inactive Lys220Arg GRK2 to the similar extent. The present study demonstrates the presence of phosphorylation-independent desensitization mechanism in delta 40 ETBR and suggests that GRK2 might play a role other than that as a kinase.     

Crosstalk between oral squamous cell carcinoma cells and cancer-associated fibroblasts via the TGF-β/SOX9 axis in cancer progression

Cancer-associated fibroblasts (CAFs) have important roles in promoting cancer development and progression. We previously reported that high expression of sex-determining region Y (SRY)-box9 (SOX9) in oral squamous cell carcinoma (OSCC) cells was positively correlated with poor prognosis. This study developed three-dimensional (3D) in vitro models co-cultured with OSCC cells and CAFs to examine CAF-mediated cancer migration and invasion in vitro and in vivo. Moreover, we performed an immunohistochemical analysis of alpha-smooth muscle actin and SOX9 expression in surgical specimens from 65 OSCC patients. The results indicated that CAFs promote cancer migration and invasion in migration assays and 3D in vitro models. The invading OSCC cells exhibited significant SOX9 expression and changes in the expression of epithelial–mesenchymal transition (EMT) markers, suggesting that SOX9 promotes EMT. TGF-β1 signalling inhibition reduced SOX9 expression and cancer invasion in vitro and in vivo, indicating that TGF-β1-mediated invasion is dependent on SOX9. In surgical specimens, the presence of CAFs was correlated with SOX9 expression in the invasive cancer nests and had a significant impact on regional recurrence. These findings demonstrate that CAFs promote cancer migration and invasion via the TGF-β/SOX9 axis.