Hiroshima University

About: Hiroshima University is a education organization based out in Hiroshima, Japan. It is known for research contribution in the topics: Population & Cancer. The organization has 33602 authors who have published 69290 publications receiving 1495648 citations. The organization is also known as: Hiroshima Daigaku.

Performance Study of Aqueous Polyaniline Batteries

Abstract: The characteristics of electrochemically produced polyaniline as the active material of secondary batteries were studied in aqueous electrolytes. The cell of the type, , has the maximum capacity of 108 Ah/kg and the energy density of 111 Wh/kg. The coulombic efficiency was close to 100% over at least 2000 complete cycles when cycled between 1.35V and 0.75V at a constant current of 1 mA cm−2. The cell, where polyaniline was used as the anode, also showed excellent recyclability. The effect of oxygen and of the exposure to high anodic potential to the characteristics of polyaniline electrodes was also studied.

Downregulation of Bim, a Proapoptotic Relative of Bcl-2, Is a Pivotal Step in Cytokine-Initiated Survival Signaling in Murine Hematopoietic Progenitors

Abstract: Two distinct signaling pathways regulate the survival of interleukin-3 (IL-3)-dependent hematopoietic progenitors. One originates from the membrane-proximal portion of the cytoplasmic domain of the IL-3 receptor (betac chain), which is shared by IL-3 and granulocyte-macrophage colony-stimulating factor and is involved in the regulation of Bcl-x(L) through activation of STAT5. The other pathway emanates from the distal region of the betac chain and overlaps with downstream signals from constitutively active Ras proteins. Although the latter pathway is indispensable for cell survival, its downstream targets remain largely undefined. Here we show that the expression of Bim, a member of the BH3-only subfamily of cell death activators, is downregulated by IL-3 signaling through either of two major Ras pathways: Raf/mitogen-activated protein kinase and the phosphatidylinositol 3-kinase/mammalian target of rapamycin. Akt/phosphokinase B does not appear to play a significant role in this regulatory cascade. Bim downregulation has important implications for cell survival, since enforced expression of this death activator at levels equivalent to those induced by cytokine withdrawal led to apoptosis even in the presence of IL-3. We conclude that Bim is a pivotal molecule in cytokine regulation of hematopoietic cell survival.

Rad51 Accumulation at Sites of DNA Damage and in Postreplicative Chromatin

Abstract: Rad51, a eukaryotic RecA homologue, plays a central role in homologous recombinational repair of DNA double-strand breaks (DSBs) in yeast and is conserved from yeast to human. Rad51 shows punctuate nuclear localization in human cells, called Rad51 foci, typically during the S phase (Tashiro, S., N. Kotomura, A. Shinohara, K. Tanaka, K. Ueda, and N. Kamada. 1996. Oncogene. 12:2165–2170). However, the topological relationships that exist in human S phase nuclei between Rad51 foci and damaged chromatin have not been studied thus far. Here, we report on ultraviolet microirradiation experiments of small nuclear areas and on whole cell ultraviolet C (UVC) irradiation experiments performed with a human fibroblast cell line. Before UV irradiation, nuclear DNA was sensitized by the incorporation of halogenated thymidine analogues. These experiments demonstrate the redistribution of Rad51 to the selectively damaged, labeled chromatin. Rad51 recruitment takes place from Rad51 foci scattered throughout the nucleus of nonirradiated cells in S phase. We also demonstrate the preferential association of Rad51 foci with postreplicative chromatin in contrast to replicating chromatin using a double labeling procedure with halogenated thymidine analogues. This finding supports a role of Rad51 in recombinational repair processes of DNA damage present in postreplicative chromatin.

Wnt5a signaling is involved in the aggressiveness of prostate cancer and expression of metalloproteinase.

Abstract: Wnt5a is a representative ligand that activates the beta-catenin-independent pathway in Wnt signaling. Although it has been reported that abnormal activation of the Wnt/beta-catenin-dependent pathway is often observed in human prostate cancer, the involvement of the beta-catenin-independent pathway in this cancer is unclear. Abnormal expression of Wnt5a and beta-catenin was observed in 27 (28%) and 49 (50%) of 98 prostate cancer cases, respectively, by immunohistochemical analyses. Simultaneous expression of Wnt5a and beta-catenin was observed in only five cases, suggesting their exclusive expression. The positive detection of Wnt5a was correlated with high Gleason scores and biochemical relapse of prostate cancer, but that of beta-catenin was not. Knockdown and overexpression of Wnt5a in human prostate cancer cell lines reduced and stimulated, respectively, their invasion activities, and the invasion activity required Frizzled2 and Ror2 as Wnt receptors. Wnt5a activated Jun-N-terminal kinase through protein kinase D (PKD) and the inhibition of PKD suppressed Wnt5a-dependent cell migration and invasion. In addition, Wnt5a induced the expression of metalloproteinase-1 through the recruitment of JunD to its promoter region. These results suggest that Wnt5a promotes the aggressiveness of prostate cancer and that its expression is involved in relapse after prostatectomy.

Telomerase activity is detected in pancreatic cancer but not in benign tumors

Abstract: Activation of telomerase and stabilization of telomeres are considered to be necessary for immortalization of human tumor cells. In the present study, telomerase activity was detected in 41 (95%) of 43 pancreatic cancer specimens but was detectable in none of 11 benign pancreatic tumors and only one of 3 pancreatitis samples. Low levels of telomerase activity were detected in 5 (14%) of 36 adjacent "normal" pancreatic tissues. These five telomerase-positive "normal" specimens were obtained from patients that also had pancreatic cancer and may reflect occult microinvasion. Telomerase activity was examined in 12 ex vivo brushing samples of the pancreatic duct, and 8 of 8 with pancreatic cancer had detectable telomerase activity, whereas 0 of 4 of benign lesions (cystadenoma and pancreatitis) did. These findings suggest that telomerase activity in cells derived from pancreatic ducts may be useful in the diagnosis of cancer and that telomerase activity may be a critical or rate-limiting step in pancreatic carcinogenesis.