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Miyoshi, Japan

Utsumi F.,Nagoya University | Kajiyama H.,Nagoya University | Nakamura K.,Nagoya University | Tanaka H.,Nagoya University | And 6 more authors.

Purpose: Nonequilibrium atmospheric pressure plasma (NEAPP) therapy has recently been focused on as a novel medical practice. Using cells with acquired paclitaxel/cisplatin resistance, we elucidated effects of indirect NEAPP-activated medium (NEAPP-AM) exposure on cell viability and tumor growth in vitro and in vivo. Methods: Using chronic paclitaxel/cisplatin-resistant ovarian cancer cells, we applied indirect NEAPP-exposed medium to cells and xenografted tumors in a mouse model. Furthermore, we examined the role of reactive oxygen species (ROS) or their scavengers in the above-mentioned EOC cells. Results: We assessed the viability of NOS2 and NOS3 cells exposed to NEAPP-AM, which was prepared beforehand by irradiation with NEAPP for the indicated time. In NOS2 cells, viability decreased by approximately 30% after NEAPP-AM 120-sec treatment (P<0.01). The growth-inhibitory effects of NEAPP-AM were completely inhibited by N-acetyl cysteine treatment, while L-buthionine-[S, R]-sulfoximine, an inhibitor of the ROS scavenger used with NEAPP-AM, decreased cell viability by 85% after NEAPP-AM 60-sec treatment(P<0.05) and by 52% after 120 sec, compared to the control (P<0.01). In the murine subcutaneous tumor-formation model, NEAPP-AM injection resulted in an average inhibition of the NOS2 cell-inoculated tumor by 66% (P<0.05) and NOS2TR cell-inoculated tumor by 52% (P<0.05), as compared with the control. Conclusion: We demonstrated that plasma-activated medium also had an anti-tumor effect on chemo-resistant cells in vitro and in vivo. Indirect plasma therapy is a promising treatment option for EOC and may contribute to a better patient prognosis in the future. © 2013 Utsumi et al. Source

Hagino T.,Nagoya University | Kondo H.,Nagoya University | Ishikawa K.,Nagoya University | Kano H.,NU eco Engineering Co. | And 2 more authors.
Applied Physics Express

Ultrahigh-speed synthesis of high-crystallinity nanographene was realized using an alcohol in-liquid plasma, which was generated from a nonequilibrium microhollow atmospheric-pressure plasma with an ultrahigh electron density. The synthesis rates of carbon materials were 0.61 and 1.72 mg/min using ethanol and butanol, respectively. Multilayer nanographene structures obtained using ethanol had an interlayer spacing of 0.33 nm, corresponding to that of (002) planes in graphite. The G-, D-, D'-, and 2D-band peaks in the Raman spectrum also confirmed the formation of nanographene. The mechanism of gradual growth of six-membered ring structures was clarified by gas chromatography of the filtrate. © 2012 The Japan Society of Applied Physics. Source

Hiramatsu M.,Meijo University | Mitsuguchi S.,Meijo University | Horibe T.,Nagoya University | Kondo H.,Nagoya University | And 2 more authors.
Japanese Journal of Applied Physics

Carbon nanowalls (CNWs) can be described as self-assembled, vertically standing, few-layered graphene sheet nanostructures. In order to demonstrate the usefulness of CNWs in fuel cell application, CNWs were directly grown on carbon fiber paper (CFP) using the inductively coupled plasma-enhanced chemical vapor deposition (ICP-CVD) method. Subsequently, highly dispersed platinum (Pt) nanoparticles were formed on the surface of CNWs using metal-organic chemical fluid deposition (MOCFD) employing a supercritical fluid (SCF). Moreover, a single proton exchange membrane (PEM) fuel cell unit using a Pt-supported CNW/CFP electrode was constructed, and its voltage-current characteristics were measured. This configuration ensures that all the supported Pt nanoparticles are in electrical contact with the external electrical circuit. Such a design would improve Pt utilization and potentially decrease Pt usage. Pt-supported CNWs grown on CFP will be well suited to the application in electrodes of fuel cells. © 2013 The Japan Society of Applied Physics. Source

Iseki S.,Nagoya University | Nakamura K.,Nagoya University | Hayashi M.,Nagoya University | Tanaka H.,Nagoya University | And 5 more authors.
Applied Physics Letters

Two independent ovarian cancer cell lines and fibroblast controls were treated with nonequilibrium atmospheric pressure plasma (NEAPP). Most ovarian cancer cells were detached from the culture dish by continuous plasma treatment to a single spot on the dish. Next, the plasma source was applied over the whole dish using a robot arm. In vitro cell proliferation assays showed that plasma treatments significantly decreased proliferation rates of ovarian cancer cells compared to fibroblast cells. Flow cytometry and western blot analysis showed that plasma treatment of ovarian cancer cells induced apoptosis. NEAPP could be a promising tool for therapy for ovarian cancers. © 2012 American Institute of Physics. Source

Tanaka H.,Nagoya University | Mizuno M.,Nagoya University | Ishikawa K.,Nagoya University | Nakamura K.,Nagoya University | And 4 more authors.
Plasma Medicine

Glioblastoma brain tumor cells and normal astrocytes were treated with plasma-activated medium (PAM). Cell proliferation assays showed that glioblastoma cells were selectively killed by PAM. PAM induced morphological changes consistent with apoptosis in glioblastoma cells and the cells decreased in size. We confirmed that those cells induced apoptosis using an apoptotic molecular marker, cleaved Caspase3/7. To elucidate the molecular mechanisms of PAM-mediated apoptosis in glioblastoma cells, we investigated the effects of survival signal transduction pathways. We found that PAM downregulated the expression of AKT kinase, a marker molecule in a survival signal transduction pathway. These results suggest that PAM may be a promising tool for therapy of glioblastoma brain tumors by downregulating the survival signals in cancers. © 2011 by Begell House, Inc. Source

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