Kyoto University

About: Kyoto University is a education organization based out in Kyoto, Japan. It is known for research contribution in the topics: Population & Catalysis. The organization has 85837 authors who have published 217215 publications receiving 6526826 citations. The organization is also known as: Kyōto University & Kyōto daigaku.

Constitutive activation of the 41-/43-kDa mitogen-activated protein kinase signaling pathway in human tumors

Abstract: The 41-kDa and 43-kDa mitogen-activated protein (MAP) kinases play a pivotal role in the mitogenic signal transduction pathway and are essential components of the MAP kinase cascade, which includes MAP kinase kinase (MEK) and Raf-1. As aberrant activation of signal transducing molecules such as Ras and Raf-1 has been linked with cancer, we examined whether constitutive activation of the 41-/43-kDa MAP kinases is associated with the neoplastic phenotype of 138 tumor cell lines and 102 primary tumors derived from various human organs. Constitutive activation of the MAP kinases was observed in 50 tumor cell lines (36.2%) in a rather tissue-specific manner: cell lines derived from pancreas, colon, lung, ovary and kidney showed especially high frequencies with a high degree of MAP kinase activation, while those derived from brain, esophagus, stomach, liver and of hematopoietic origin showed low frequencies with a limited degree of MAP kinase activation. We also detected constitutive activation of the 41-/43-kDa MAP kinases in a relatively large number of primary human tumors derived from kidney, colon and lung tissues but not from liver tissue. Many tumor cells, in which point mutations of ras genes were detected, showed constitutive activation of MAP kinases, however, there were also many exceptions to this observation. In contrast, the activation of the 41-/43-kDa MAP kinases was accompanied by the activation of Raf-1 in the majority of tumor cells and was completely associated with the activation of MEK and p90rsk in all the tumor cells examined. These results suggest that the constitutive activation of 41-/43-kDa MAP kinases in tumor cells is not due to the disorder of MAP kinases themselves, but is due to the disorder of Raf-1, Ras, or some other signaling molecules upstream of Ras.

Cloudiness Fluctuations Associated with the Northern Hemisphere Summer Monsoon

Abstract: The broad-scale fluctuations of cloudiness over the Eastern Hemisphere during the northern summer monsoon were investigated by using daily satellite mosaic pictures taken from June 1 to September 30, 1973. Spectral analysis revealed two dominant periodicities, of around 40 days and around 15 days. Cross-spectral, time-sectional, time-lag correlation and phase-lag vector analysis were applied to reveal the characteristics of these two modes in the time-space field. The fluctuation of 40-day period shows marked northward movement of cloudiness from the equatorial zone to the mid-latitudes (around 30 * E) over the whole Asian monsoon area, and southward movement over Africa and the central Pacific. The northward movement is most apparent over the India-Indian Ocean sector. The fluctuation of this mode is associated with the major "active"-"break" cycle of the monsoon over the whole Asian monsoon area. The fluctuation of 15-day period shows similar features to that of 40-day period, but includes two clockwise rotations, one over India and Southeast Asia and the other over the western Pacific. A southward movement from the equatorial zone to the Southern Hemisphere middle latitudes is also prominent to the east and west of Australia. The fluctuation of this mode seems to correspond with the movements of equatorial, monsoon (or tropical), and westerly disturbances. It is also suggested that the fluctuation of 40-day period may be closely connected with the global-scale zonal oscillation in the equatorial zone and that of 15-day period may exist as a result of meridional wave interactions.

Prostaglandin D2 as a Mediator of Allergic Asthma

Abstract: Allergic asthma is caused by the aberrant expansion in the lung of T helper cells that produce type 2 (TH2) cytokines and is characterized by infiltration of eosinophils and bronchial hyperreactivity. This disease is often triggered by mast cells activated by immunoglobulin E (IgE)-mediated allergic challenge. Activated mast cells release various chemical mediators, including prostaglandin D2 (PGD2), whose role in allergic asthma has now been investigated by the generation of mice deficient in the PGD receptor (DP). Sensitization and aerosol challenge of the homozygous mutant (DP-/-) mice with ovalbumin (OVA) induced increases in the serum concentration of IgE similar to those in wild-type mice subjected to this model of asthma. However, the concentrations of TH2 cytokines and the extent of lymphocyte accumulation in the lung of OVA-challenged DP-/- mice were greatly reduced compared with those in wild-type animals. Moreover, DP-/- mice showed only marginal infiltration of eosinophils and failed to develop airway hyperreactivity. Thus, PGD2 functions as a mast cell-derived mediator to trigger asthmatic responses.

Bose-Einstein Condensation with Internal Degrees of Freedom in Alkali Atom Gases

Abstract: The Bogoliubov theory is extended to a Bose-Einstein condensation with internal degrees of freedom, realized recently in 23 Na gases where several hyperfine states are simultaneously cooled optically. Starting with a Hamiltonian constructed from general gauge and spin rotation symmetry principles, fundamental equations for condensate are derived. The ground state where time reversal symmetry is broken in some cases and low-lying collective modes, e.g. spin and density wave modes, are discussed. Novel vortex as a topological defect can be created experimentally.

Benefit of Adjuvant Chemotherapy for Resectable Gastric Cancer A Meta-analysis

Abstract: CONTEXT Despite potentially curative resection of stomach cancer, 50% to 90% of patients die of disease relapse. Numerous randomized clinical trials (RCTs) have compared surgery alone with adjuvant chemotherapy, but definitive evidence is lacking. OBJECTIVES To perform an individual patient-level meta-analysis of all RCTs to quantify the potential benefit of chemotherapy after complete resection over surgery alone in terms of overall survival and disease-free survival, and to further study the role of regimens, including monochemotherapy; combined chemotherapy with fluorouracil derivatives, mitomycin C, and other therapies but no anthracyclines; combined chemotherapy with fluorouracil derivatives, mitomycin C, and anthracyclines; and other treatments. DATA SOURCES Data from all RCTs comparing adjuvant chemotherapy with surgery alone in patients with resectable gastric cancer. We searched MEDLINE (up to 2009), the Cochrane Central Register of Controlled Trials, the National Institutes of Health trial registry, and published proceedings from major oncologic and gastrointestinal cancer meetings. STUDY SELECTION All RCTs closed to patient recruitment before 2004 were eligible. Trials testing radiotherapy; neoadjuvant, perioperative, or intraperitoneal chemotherapy; or immunotherapy were excluded. Thirty-one eligible trials (6390 patients) were identified. DATA EXTRACTION As of 2010, individual patient data were available from 17 trials (3838 patients representing 60% of the targeted data) with a median follow-up exceeding 7 years. RESULTS There were 1000 deaths among 1924 patients assigned to chemotherapy groups and 1067 deaths among 1857 patients assigned to surgery-only groups. Adjuvant chemotherapy was associated with a statistically significant benefit in terms of overall survival (hazard ratio [HR], 0.82; 95% confidence interval [CI], 0.76-0.90; P < .001) and disease-free survival (HR, 0.82; 95% CI, 0.75-0.90; P < .001). There was no significant heterogeneity for overall survival across RCTs (P = .52) or the 4 regimen groups (P = .13). Five-year overall survival increased from 49.6% to 55.3% with chemotherapy. CONCLUSION Among the RCTs included, postoperative adjuvant chemotherapy based on fluorouracil regimens was associated with reduced risk of death in gastric cancer compared with surgery alone.