Genetic alterations in gliosarcoma and giant cell glioblastoma

The majority of glioblastomas develop rapidly with a short clinical history (primary glioblastoma IDH wild-type), whereas secondary glioblastomas progress from diffuse astrocytoma or anaplastic astrocytoma. IDH mutations are the genetic hallmark of secondary glioblastomas. Gliosarcomas and giant cell glioblastomas are rare histological glioblastoma variants, which usually develop rapidly. We determined the genetic patterns of 36 gliosarcomas and 19 giant cell glioblastomas. IDH1 and IDH2 mutations were absent in all 36 gliosarcomas and in 18 of 19 giant cell glioblastomas analyzed, indicating that they are histological variants of primary glioblastoma. Furthermore, LOH 10q (88%) and TERT promoter mutations (83%) were frequent in gliosarcomas. Copy number profiling using the 450k methylome array in 5 gliosarcomas revealed CDKN2A homozygous deletion (3 cases), trisomy chromosome 7 (2 cases), and monosomy chromosome 10 (2 cases). Giant cell glioblastomas had LOH 10q in 50% and LOH 19q in 42% of cases. ATRX loss was detected immunohistochemically in 19% of giant cell glioblastomas, but absent in 17 gliosarcomas. These and previous results suggest that gliosarcomas are a variant of, and genetically similar to, primary glioblastomas, except for a lack of EGFR amplification, while giant cell glioblastoma occupies a hybrid position between primary and secondary glioblastomas. This article is protected by copyright. All rights reserved

Localization of cyclophilin A and cyclophilin C mRNA in murine kidney using RT-PCR

Localization of cyclophilin A and cyclophilin C mRNA in murine kidney using RT-PCR. Cyclosporin A (CsA), which is widely used as an immunosuppressant, has a nephrotoxic side effect. The mechanism of this nephrotoxicity is not well understood; however, recent studies suggest that cyclophilin (cyp) is responsible for mediating the immunosuppressive action of CsA through the interaction with the Ca2+ - and calmodulin-dependent phosphatase, calcineurin. While cyp A mRNA is expressed ubiquitously, cyp C mRNA has been shown to be topically expressed, including in the kidney. We examined: (1) distribution of cyp A and cyp C mRNA in microdissected murine nephron segments, using a combination of reverse transcription and polymerase chain reaction (RT-PCR) techniques, and (2) the effect of CsA administration on cyp C mRNA expression in proximal convoluted tubule. Among the nephron segments examined, large signals for cyp C PCR product were detected in proximal convoluted tubule and proximal straight tubule. Our data showed that the distribution of cyp C mRNA was uneven, and it mainly existed in segments that are relatively sensitive to CsA toxicity. In contrast, cyp A mRNA was found to be distributed almost equally along the nephron segments examined. By CsA administration, the signal for cyp C mRNA PCR product was increased. These results suggest that cyp C may play some role in the renal tubular disorder observed in CsA nephrotoxicity

Key Role of Human ABC Transporter ABCG2 in Photodynamic Therapy and Photodynamic Diagnosis

Accumulating evidence indicates that ATP-binding cassette (ABC) transporter ABCG2 plays a key role in regulating the cellular accumulation of porphyrin derivatives in cancer cells and thereby affects the efficacy of photodynamic therapy and photodynamic diagnosis. The activity of porphyrin efflux can be affected by genetic polymorphisms in the ABCG2 gene. On the other hand, Nrf2, an NF-E2-related transcription factor, has been shown to be involved in oxidative stress-mediated induction of the ABCG2 gene. Since patients have demonstrated individual differences in their response to photodynamic therapy, transcriptional activation and/or genetic polymorphisms of the ABCG2 gene in cancer cells may affect patients' responses to photodynamic therapy. Protein kinase inhibitors, including imatinib mesylate and gefitinib, are suggested to potentially enhance the efficacy of photodynamic therapy by blocking ABCG2-mediated porphyrin efflux from cancer cells. This review article provides an overview on the role of human ABC transporter ABCG2 in photodynamic therapy and photodynamic diagnosis

Laboratory-based X-ray phase-imaging scanner using Talbot-Lau interferometer for non-destructive testing

An X-ray Talbot-Lau interferometer scanning setup consisting of three transmission gratings, a laboratory-based X-ray source that emits X-rays vertically, and an image detector on the top has been developed for the application of X-ray phase imaging to moving objects that cannot be tested clearly with conventional absorption contrast. The grating-based X-ray phase imaging method usually employs a phase-stepping (or fringe-scanning) technique by displacing one of the gratings step-by-step while the object stays still. Since this approach is not compatible with a scanner-type application for moving objects, we have developed a new algorithm for achieving the function of phase-stepping without grating displacement. By analyzing the movie of the moiré pattern as the object moves across the field of view, we obtain the absorption, differential phase, and visibility images. The feasibility of the X-ray phase imaging scanner has been successfully demonstrated for a long sample moving at 5 mm/s. This achievement is a breakthrough for the practical industrial application of X-ray phase imaging for screening objects carried on belt-conveyers such as those in factories

Empirical Calculation Method of Bypass Leakage in Scroll Compressors

This study presents an empirical method to calculate the bypass leakage mass flow rate along the tip seal in a scroll compressor. The leakage flows through small axial and radial clearances between the orbiting and fixed scrolls of scroll compressor were previously studied by Ishii et al. In these earlier studies, the pressure decay in the pressurized vessel due to leakage through the axial and radial clearances was measured using a maximum pressure of 3 MPa for CO2 and 0.6 MPa for R22. The Darcy-Weisbach equation for incompressible, viscous fluid flow through the thin rectangular cross-section was applied to calculate the leakage mass flow rate that matched the pressure decay characteristics. The empirical friction factors were determined and plotted on a Moody diagram. As a result, the empirical friction factors for both axial and radial clearance leakage flows have been determined and shown to take on essentially the same value for both CO2 and R22, despite the significantly different working pressures. In contrast, the flow patterns in bypass leakage along the tip seal are so complicated that not even the leakage characteristics are known definitively. No method exists for calculating the bypass leakage mass flow rate. In the present study, a bypass leakage model was constructed, compatible with a production-type scroll compressor with a large cooling capacity. A similar test of the pressure decay in the pressurized vessel due to bypass leakages were conducted with the refrigerant gas R410A. The measured pressure decay characteristics were then simulated by the Darcy-Weisbach equation with the empirical friction factors from our previous study for the leakage flow through the axial clearance. In the present simulations of the measured pressure decay, the complicated flow patterns through bypass clearances were classified into two representative rectangular thin cross-section leakage passes, one with an equivalent width and the other with an equivalent length. Empirical friction factor values for the equivalent pass width and length were determined to match the measured pressure decays. As a result, the calculation of the bypass leakage flow rate along the tip seal in scroll compressors can be accomplished using a simple scheme in terms of the equivalent pass width and equivalent pass length for two representative leakage passes forming a thin rectangular cross-section and applying empirically determined friction factors,

Lubrication Tests to Support Optimal Performance Design Guidelines for Thrust Slide-Bearings in Scroll Compressors

This study focuses on the role of lubrication in the optimal performance design guidelines for the thrust slide-bearings in scroll compressors. The theoretical analysis of Ishii et al. showed that the minimum friction power loss in the thrust slide-bearing occurs at a certain outer radius of the friction surface. In the theoretical development, the physical thrust slide-bearing was modeled as a cylindrical thrust plate, representing the orbiting scroll, and the flat plate, representing the fixed scroll, with the same friction area as the physical bearing. The outer radius of the friction surface was varied for a fixed inner radius, where the fluid wedge angle between the sliding surfaces, due to axial loading on the thrust plate, was assumed to be constant at a small value. The average Reynolds equation by Patier & Cheng and the solid contact theory by Greenwood & Williamson were applied to calculate the resultant lubrication performance and finally the friction power loss at the sliding surface. The model showed that the friction power loss drastically decreases and then gradually increases, with increasing outer radius of the sliding surface.  The minimum value of friction power loss was about 80% lower than that of the conventional design thrust slide-bering. In order to confirm experimentally this predicted optimal lubrication performance, a thrust slide-bearing cylindrical-model submerged in a refrigerant oil SUNISO-RB68A was operated under pressurized conditions using R410A as the pressurizing gas. The pressure difference across the friction surface of the thrust bearing was fixed at 0.6 MPa, corresponding to the rated operation condition of a small cooling capacity scroll compressor. In the experiments, a special device was fabricated to maintain a constant fluid wedge angle between the friction surfaces due to the net pressure-induced elastic deformation of the thrust plate. The friction power loss at the friction surface was measured over a wide range of orbiting speeds from 1200 rpm up to 6000 rpm for a fixed orbiting radius of 3.0 mm. The resulting measured data exhibited showed the predicted tendency that the lubrication of the thrust slide-bearing is substabtially by increasing the outer radius. The friction power loss decreased with increasing outer-to-inner radii ratio of friction surface. The minimum loss occurred at an outer-to-inner radii ratio of about 2.1 for an operating speed of 3600 rpm, a significant 80% reduction relative to the usual conventional design ratio

Downregulation of organic anion transporters in rat kidney under ischemia/reperfusion-induced qacute renal failure

The effect of acute renal failure (ARF) induced by ischemia/reperfusion (I/R) of rat kidney on the expression of organic anion transporters (OATs) was examined. The level of serum indoxyl sulfate (IS), a uremic toxin and substrate of OATs in renal tubules, shows a marked increase with the progression of ARF. However, this increase was significantly attenuated by ingestion of cobalt. The level of mRNA and protein of both rOAT1 and rOAT3 were markedly depressed in the ischemic kidney. The uptake of p-aminohippuric acid (PAH) and estrone sulfate (ES) by renal slices of ischemic rats was significantly reduced compared to control rats. Renal slices taken from ischemic rats treated with cobalt displayed significantly elevated levels of ES uptake. Cobalt intake did not affect PAH uptake, indicating the functional restoration of rOAT3 but not rOAT1. The expression of Na+/K+-ATPase was markedly depressed in the ischemic kidney, suggesting that the inward Na+ gradient in renal tubular cells had collapsed, thereby reducing the outward gradient of α-ketoglutarate, a driving force of both rOATs. The decreased expression of Na+/K+-ATPase was significantly restored by cobalt treatment. Our results suggest that the downregulation of renal rOAT1 and rOAT3 could be responsible for the increase in serum IS level of ischemic rats. Cobalt treatment has a significant protective effect on ischemia-induced ARF, being accompanied by the restoration of rOAT3 and/or Na+/K+-ATPase function

実習体験で教師イメージがどのように変わるか : PAC分析による日本語非母語話者実習生の事例研究

お茶の水女子大学お茶の水女子大学お茶の水女子大学地域日本語教育を中心に外国人と日本人が共に学ぶ日本語教室づくりが広がりを見せている。こうした双方向的な学び合いをコンセプトとする教育実習に実習生として参加したとき,日本語非母語話者実習生はこの新規学習体験をどのように受け止めるのだろうか。本稿は,個人別態度構造分析(PAC分析)の手法を用いて,ある中国語母語話者実習生の受け止め方を探ったものである。具体的には,この実習生の日本語教師に関するイメージ構造を実習参加の前後で分析し,教師イメージとそれまでの経験の交差を見た。その結果,《実用的な日本語を授ける教師》から《多様な学習者ニーズに応える教師》へと教師イメージの質的な変容が見られ,実習後には,共生社会における日本語教師の役割や,学習者との学び合いに関する気づきが観察された。For co-existence in Japanese society, native Japanese speakers and non-native speakers must learn from each other\u27s dialogue. Recently, Japanese classrooms in which native Japanese speakers learn with foreigners have become more ubiquitous. But how does a non-native speaking, Japanese language teaching intern, who has never experienced the concept of such language classes in his/her own country, internalize meaning from this type of situation? In this paper, we use the Personal Attitude Construct (PAC) to analyze one Chinese teaching intern in order to report how her image of being a Japanese language teacher changed. In particular, we looked at the changes before and after her experience teaching a Japanese class in which multilingual and multicultural people dialogue in "problem-posing learning" so as to better promote their co-existence in Japan. We found her impressions changed qualitatively. She had thought the teacher who merely gives lessons in practical Japanese adequate, but with practice she progressed to one who can appropriately react to many more of the students\u27 needs. After her teaching practice, she became aware of both the more holistic role of being a non-native teacher in a society driving for native and non-native speakers\u27 co-existence, and the benefits of learning from her students