ω-Carboxyl variants of 7-ketocholesteryl esters are ligands for β2-glycoprotein I and mediate antibody-dependent uptake of oxidized LDL by macrophages

beta(2)-Glycoprotein I (beta(2)-GPI) is a major antigen for anticardiolipin antibodies (aCL, Abs) present in patients with antiphospholipid syndrome. We recently reported that beta(2)-GPI specifically binds to oxidized LDL (oxLDL) and that the beta(2)-GPI's major ligand, oxLig-1 is 7-ketocholesteryl-9-carboxynonanoate (Kobayashi, K, E. Matsuura, Q. P. Liu, J. Furukawa, K. Kaihara, J. Inagaki, T. Atsumi, N. Sakairi, T. Yasuda, D. R. Welker, and T. Koike. 2001. A specific ligand for beta(2)-glycoprotein I mediates autoantibody-dependent uptake of oxidized low density lipoprotein by macrophages. J Lipid Res. 42: 697-709). In the present study, we demonstrate that omega-carboxylated 7-ketocholesteryl esters are critical for beta(2)-GPI binding. A positive ion mass spectrum of a novel ligand, designated oxLig-2, showed fragmented ions at m/z 383 and 441 in the presence of acetone, which share features of oxLig-1 and 7-ketocholesterol. In the negative ion mode, ions at m/z 627, 625, and 243 were observed. oxLig-2 was most likely 7-ketocholesteryl-12-carboxy (keto) dodecanoate. These ligands were recognized by beta(2)-GPI. Liposome binding to macrophages was significantly increased depending on the ligand's concentration, in the presence of beta(2)-GPI and an anti-beta(2)-GPI Ab. Synthesized variant, 7-ketocholesteryl-13-carboxytxidecanoate (13-COOH-7KC), also showed a significant interaction with beta(2)-GPI and a similar binding profile with macrophages. Methylation of the carboxyl function diminished all of the specific ligand interactions with beta(2)-GPI. Thus, omega-carboxyl variants of 7-ketocholesteryl esters can mediate anti-beta(2)-GPI Ab-dependent uptake of oxLDL by macrophages, and autoimmune atherogenesis linked to beta(2)-GPI interaction with oxLDL

Current trends in intraoperative neurophysiological monitoring among Asia–Pacific countries: an Asia–Pacific Spine Society survey

Study Design A prospective web-based survey. Purpose Although intraoperative neurophysiological monitoring (IONM) is critical in spine surgery, its usage is largely based on the surgeon’s discretion, and studies on its usage trends in Asia–Pacific countries are lacking. This study aimed to examine current trends in IONM usage in Asia–Pacific countries. Overview of Literature IONM is an important tool for minimizing neurological complications and detecting spinal cord injuries after spine surgery. IONM can be performed using several modalities, such as transcranial electrical stimulation-muscle evoked potentials (Tc-MEP) and somatosensory evoked potentials (SEP). Methods Spine surgeons of the Asia–Pacific Spine Society were asked to respond to a web-based survey on IONM. The questionnaire covered various aspects of IONM, including its common modality, Tc-MEP details, necessities for consistent use, and recommended modalities in major spine surgeries and representative surgical procedures. Results Responses were received from 193 of 626 spine surgeons. Among these respondents, 177 used IONM routinely. Among these 177 respondents, 17 mainly used SEP, whereas the majority favored Tc-MEPs. Although a >50% decrease is the commonly used alarm point in Tc-MEP, half of the Tc-MEP users had no protocols planned for such scenarios. Moreover, half of the Tc-MEP users experienced complications, with bite injuries being the most common. Most respondents strongly recommended IONM in deformity surgery for pediatric and adult populations and tumor resection surgery for intramedullary spinal cord tumors. Conversely, IONM was the least recommended in lumbar spinal canal stenosis surgery. Conclusions Spine surgeons in Asia–Pacific countries favored IONM use, indicating widespread routine utilization. Tc-MEP was the predominant modality for IONM, followed by SEPs

Schwann-Spheres Derived from Injured Peripheral Nerves in Adult Mice - Their In Vitro Characterization and Therapeutic Potential

Multipotent somatic stem cells have been identified in various adult tissues. However, the stem/progenitor cells of the peripheral nerves have been isolated only from fetal tissues. Here, we isolated Schwann-cell precursors/immature Schwann cells from the injured peripheral nerves of adult mice using a floating culture technique that we call “Schwann-spheres." The Schwann-spheres were derived from de-differentiated mature Schwann cells harvested 24 hours to 6 weeks after peripheral nerve injury. They had extensive self-renewal and differentiation capabilities. They strongly expressed the immature-Schwann-cell marker p75, and differentiated only into the Schwann-cell lineage. The spheres showed enhanced myelin formation and neurite growth compared to mature Schwann cells in vitro. Mature Schwann cells have been considered a promising candidate for cell-transplantation therapies to repair the damaged nervous system, whereas these “Schwann-spheres" would provide a more potential autologous cell source for such transplantation

Measurement of Oxygen Gas Transport Resistance in Cathode Catalyst Layers of PEFC

Introduction Polymer electrolyte fuel cells (PEFCs) are a promising power sources for automotive use. For the commercialization, cost reduction is one of the most important issues. In order to reduce cost, the Pt-loading of a membrane electrode assembly (MAE) should be reduced. Many studies for this purpose have been done. As a part of such studies, in-situ analytical methods for evaluating oxygen transport properties have been developed using limiting current measurements1)2). It is said that oxygen gas transport resistance in catalyst layers CLs (RCL) is mainly consisted of two parts, diffusion resistance in micro pore (Rpore) and diffusion resistance around Pt particles (RPt). And it has been found that the diffusion resistance RCL was significantly increased when Pt loading in CLs was reduced2). In this study, the oxygen diffusion resistances in CLs of two types of Pt/carbon catalysts with different kind of carbon support are measured by changing the ionomer carbon ratio (I/C) and the relation between I/C and RPt, Rporewas investigated. Experimental Table 1 shows the specifications of the MEAs used in this study. The MEA samples with an active area of 1cm2 were fabricated by coating CLs consisting of catalysis powders (Pt/C) and NafionR ionomer onto the perfluorosulfonated polymer membrane (NafionR NR212). Pt-loadings of the samples for the working electrode were 0.05 -0.6 mg cm-2 respectively. In order to evaluate the oxygen gas transport resistance in the CLs, limiting currents were measured in nitrogen balance gases. RCL was measured by the method of Mashio et al1). Rpore and RPt were determined by the method we described before3). Results and discussions In order to estimate Rpore and RPt, an Equation (1) was introduced with the analogy of porous electrode model and value was determined from RCL with different I/C. A imaginary limiting current inversely proportional to RCL was also introduced (eq.(2)). In Fig.1, each dot shows measured RCL, full line shows the calculation curves of RCL with eq.(1) and dotted line shows imaginary limiting current calculated by the eq.(2) with using the obtained values of Rpt and Rpore. Table2 shows Rpt and Rporevalues obtained. Rpore increased very much at I/C was 1.3 for both catalysts.Thisseems to because oftheclosure or isoration of pore by ionomer.RPtshows minimum values at some I/C whichdepend on catalyst types.From this result,RPt seems to be affected with the state of three-phase interface4)and oxygen gas permeability through ionomer. Acknowledgement This research was performed under a grant from the Cell Evaluation Project of the New Energy and Industrial Technology Development Organization (NEDO). References T.Mashio, A.Ohma, S.Yamamoto and K.Shinohara, ECS Transactions, 11(1) 529 (2007). K.Sakai, K.Sato, T.Mashio, A.Ohma, K.Yamaguchi and K.Shinohara, ECS Transactions, 25(1) 1193 (2009). H.Yasuda, K.Kobayashi, A.Daimaru and M.Hori., ECS Transactions, 50(2) 261 (2012) M. Lee, M. Uchida, H. Yano, D.A. Tryk, H. Uchida and M.Watanabe, Elecrochim. Acta 55 8504 (2010) Table 1 MEA specification Counter Electrode Working Electrode Catalyst Pt/C (CB) (TEC10E50E, TKK)Pt/C (GCB) (TEC10EA50E, TKK) Ionomer NafionR (D2020, Dupont) Pt loading /mgcm-2 0.05 – 0.6 Ionomer Carbon Ratio (I/C) 0.4 – 1.3 Active Area /cm2 1.0 Membrane NafionR (NR212, Dupont) GDL TGP H060, Toray (without MPL) Table 2 RPt and Rpore with different I/C I/C TEC10E50E TEC10EA50E RPt Rpore RPt Rpore 0.4 4.3 19 4.3 10 0.5 - - 2.8 29 0.7 3.5 13 4.0 12 1.0 2.8 46 4.8 7.8 1.3 3.5 88 5.2 69 </jats:p

Study on Protocols for Evaluating Reactant Gas Transport in Cathode Catalyst Layers of PEFC

Some in-situ techniques measuring limiting current in order to analyze the reactant gas transport structure have been proposed. By these methods, it has been found that the reactant gas transport resistance (Rother) in catalyst layers (CLs) was separated into two parts, Knudsen diffusion resistance (Rk) and the local transport resistance around Pt surface (RPt). And it was also found that RPt became significantly large when Pt load on CLs was reduced. However, the causes and contents of RPt is not clear enough today. And also some measurement methods of RPt are proposed. In order to better understanding and measurement of RPt, we tried to evaluate it by mean of these methods.</jats:p

Study on Protocols for Evaluating Reactant Gas Transport in Cathode Catalyst Layers of PEFC

Abstract not Available.</jats:p