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Articles by T Ishikawa
Total Records ( 14 ) for T Ishikawa
  Y Ichikawa , A Goto , S Hirokawa , M Kijima , T Ishikawa , T Chishima , H Suwa , H Yamamoto , S Yamagishi , S Osada , M Ota and S. Fujii
 

Allergic reactions to oxaliplatin can be severe and are an important cause of discontinuation of treatment. A retrospective review was performed for 105 patients who received FOLFOX regimens between May 2005 and June 2007. Twenty-five cases (23.8%) of allergic reactions were identified, including 9 late onset reactions (8.6%) and 16 immediate reactions (15.2%). Severe allergy (Grades 3 and 4) occurred in seven patients (6.7%). Re-introduction of FOLFOX was attempted for seven immediate onset patients with a severity grade of 1 or 2, and three of these patients (42.9%) showed relapse of allergy. In ~10% of the patients, FOLFOX had to be discontinued due to allergy before the disease became refractory to the regimen. Our experience indicates that allergy to oxaliplatin may be a significant concern and that methods are required for suppression of this allergy.

  T Ishikawa , D Shimizu , T Sasaki , S Morita , M Tanabe , I Ota , K Kawachi , A Nozawa , T Chishima , Y Ichikawa , I Endo and H. Shimada
  Objective

We investigated the pathological effects of neoadjuvant chemotherapy based on the human epidermal growth factor receptor 2 in operable breast cancer.

Methods

This prospective clinical study was a pilot involving 63 female patients. Before surgery, patients with tumors overexpressing human epidermal growth factor receptor 2 received four cycles of 60 mg/m2 anthracycline and 600 mg/m2 cyclophosphamide every 3 weeks, whereas those whose tumors did not overexpress human epidermal growth factor receptor 2 received four cycles of 75 mg/m2 docetaxel and 600 mg/m2 cyclophosphamide every 3 weeks. A quasi-pathological complete response (i.e. absence of invasive tumor or only focal residual tumor cells) was the primary endpoint, with compliance and predictors for each regimen as secondary endpoints. If a quasi-pathological complete response was not achieved, then crossover to the alternative treatment was recommended.

Results

The quasi-pathological complete response rate was 36.5% (23 of 63) overall, 27.8% (5 of 18) for the anthracycline and cyclophosphamide regimen and 40.0% (18 of 45) for the docetaxel and cyclophosphamide regimen. Docetaxel and cyclophosphamide treatment induced a quasi-pathological complete response in most patients with triple-negative tumors (15 of 19). The relative dose intensity was 97.3% for the anthracycline and cyclophosphamide regimen and 96.6% for the docetaxel and cyclophosphamide regimen. Quasi-pathological complete response to the docetaxel and cyclophosphamide regimen was associated with low estrogen receptor and progesterone receptor expression and high MIB-1 and topoisomerase II expression, in univariate analyses, but only with low estrogen receptor expression in multivariate analysis.

Conclusions

Selecting neoadjuvant chemotherapy regimens on the basis of individual human epidermal growth factor receptor 2 status improved efficacy, with docetaxel and cyclophosphamide treatment showing particular promise in tumors with the potential to be highly malignant.

  Z. S Zunic , I Celikovic , S Tokonami , T Ishikawa , P Ujic , A Onischenko , M Zhukovsky , G Milic , B Jakupi , O Cuknic , N Veselinovic , K Fujimoto , S. K Sahoo and I. Yarmoshenko
 

This paper deals with the results of the first-field use in the Balkans, i.e. Serbia and Republic of Srpska (Bosnia and Hercegovina), of a passive polycarbonate Mark II type and poliallyldiglycol carbonate (Cr-39) alpha track detectors sensitive to thoron as well as to radon. Both types of solid state nuclear track detectors were designed and supplied by National Institute of Radiological Sciences (NIRS), Chiba, Japan. The commercial names for these detectors which all have been field tested in Balkan rural communities are known as: UFO and RADUET passive discriminative radon/thoron detectors. No database of thoron and thoron progeny concentrations in dwellings in Serbia or Balkans region exist, and as a result, the level of exposure of the Serbian population to thoron and its progeny is unknown so far.

  A Sorimachi , T Ishikawa , M Janik and S. Tokonami
 

The National Institute of Radiological Sciences (NIRS) has developed passive radon (222Rn)–thoron (220Rn) discriminative detectors for a large-scale survey and has established a thoron chamber to calibrate such detectors. In order to establish quality assurance and quality control for the 220Rn measurement at NIRS, intercomparison studies have been carried out. The intercomparisons using a scintillation cell method, which has been used as a standard for 220Rn measurement at NIRS, were conducted at New York University (NYU, USA) and Physikalisch-Technische Bundesanstalt (PTB, Germany). As a result, it was found that the result from the NIRS was in good agreement with that from the NYU. On the other hand, it was observed that the relative discrepancy between the 220Rn concentrations from the NIRS and PTB monitors was, on average, >50 %. Using the NIRS 220Rn chamber, the international intercomparison experiment for passive 220Rn detectors started in 2008.

  Y Yasuoka , A Sorimachi , T Ishikawa , M Hosoda , S Tokonami , N Fukuhori and M. Janik
 

It was shown that radon and thoron concentrations exhaled from soil were separately measured using the AlphaGUARD and liquid scintillation counter (LSC) methods. The thoron concentrations from the RAD 7 were used to create the conversion equation to calculate thoron levels with the AlphaGUARD. However, the conversion factor was found to depend on the air flow rate. When air containing thoron of ~60 kBq m–3 was fed to the scintillation cocktail, thoron and thoron progeny could not be measured with the LSC method. The radon concentration of about 10 kBq m–3 was measured with three methods, first with the LSC method and then with two AlphaGUARDs (one in the diffusion mode and the other in the flow mode (0.5 l min–1)). There were no significant differences between these results. Finally, it was shown that the radon and thoron concentrations in air could be measured with the AlphaGUARD and LSC methods.

  S. K Sahoo , T Ishikawa , S Tokonami , A Sorimachi , C Kranrod , M Janik , M Hosoda , N. M Hassan , S Chanyotha , V. K Parami , H Yonehara and R. C. Ramola
 

Several industrial processes are known to enrich naturally occurring radioactive materials (NORM). To assess such processes with respect to their radiological relevance, characteristic parameters describing this enrichment will lead to interesting information useful to UNSCEAR. In case of mineral treatment plants, the high temperatures used in smelting and refining processes lead to high concentrations of 238U and 232Th. Also due to thermal power combustion, concentration of U and Th in the fly ash increases manifold. NORM samples were collected from a Thailand mineral treatment plant and Philippine coal-fired thermal power plants for investigation. Some studies are initiated from a high background radiation area near Gopalpur of Orissa state in India. These NORM samples were analysed by gamma-ray spectrometry as well as inductively coupled plasma mass spectrometry. The radioactivity in case of Orissa soil samples is found to be mainly contributed from thorium. This study attempts to evaluate levels of thorium activity in NORM samples.

  M Hosoda , S Tokonami , A Sorimachi , T Ishikawa , S. K Sahoo , M Furukawa , Y Shiroma , Y Yasuoka , M Janik , N Kavasi , S Uchida and M. Shimo
 

Field measurements of thoron exhalation rates have been carried out using a ZnS(Ag) scintillation detector with an accumulation chamber. The influence of soil surface temperature and moisture saturation on the thoron exhalation rate was observed. When the variation of moisture saturation was small, the soil surface temperature appeared to induce a strong effect on the thoron exhalation rate. On the other hand, when the variation of moisture saturation was large, the influence of moisture saturation appeared to be larger than the soil surface temperature. The number of data ranged over 405, and the median was estimated to be 0.79 Bq m–2 s–1. Dependence of geology on the thoron exhalation rate from the soil surface was obviously found, and a nationwide distribution map of the thoron exhalation rate from the soil surface was drawn by using these data. It was generally high in the southwest region than in the northeast region.

  C Kranrod , T Ishikawa , S Tokonami , A Sorimachi , S Chanyotha and N. Chankow
 

There is a well-known discrepancy between dosimetrically derived dose conversion factor (DCF) and epidemiologically derived DCF for radon. As the latter DCFs, International Commission on Radiological Protection (ICRP) recommends a value of ~6.4 nSv (Bq h m–3)–1 and 7.9 nSv (Bq h m–3)–1 for radon decay products (RnDP) in dwellings and workplaces, respectively. On the other hand, the dosimetric calculations based on the ICRP-66 respiratory tract model derived a DCF of 13 nSv (Bq h m–3)–1 and 17 nSv (Bq h m–3)–1 for RnDP in dwellings and workplaces, respectively, and 83 nSv (Bq h m–3)–1 for thoron decay products (TnDP) in dwellings. In addition, the DCFs derived from both approaches and UNSCEAR were applied to comparative dosimetry for two thoron-enhanced areas (cave dwellings in China and dwellings at a spa town in Japan), where the equilibrium equivalent concentration of radon and equilibrium equivalent concentration of thoron have been measured. In the case of the spa town dwellings, the dose from TnDP was larger than the dose from RnDP.

  N Kavasi , T Vigh , A Sorimachi , T Ishikawa , S Tokonami and M. Hosoda
 

In this study, short-term radon (RnDP) and thoron (TnDP) progeny measurements and dose estimation were carried out in winter and summer in a manganese mine, Hungary. Gamma-ray dose rate originating from external sources and 222Rn and 226Ra contents of spring-water from a mine was also measured. During working hours RnDP and TnDP concentration values changed between 12.1–175 and 0.14–0.42 Bq m–3, respectively. The 222Rn and 226Ra concentration values in the karst spring-water were ~6 Bq dm–3 and 16 mBq dm–3, respectively. The radiation dose resulting from the consumption of karst spring-water was negligible. The doses from the inhalation of TnDP and external gamma radiation were of the same magnitude, ~0.1 mSv y–1, which was rather negligible related to the estimated radiation dose of 5 mSv y–1 from RnDP.

  M Janik , S Tokonami , C Kranrod , A Sorimachi , T Ishikawa and N. M. Hassan
 

Intercomparisons of radon/thoron detectors play an important role not only for domestic radon/thoron survey but also for international or interregional discussion about radon/thoron mapping in dwellings as well as that in the soil. For these purposes, it is necessary to improve and standardise technical methods of measurement and to verify quality assurance by intercomparisons between laboratories. Therefore, the first thoron international intercomparison was provided at the NIRS (National Institute of Radiological Sciences, Japan) thoron chamber with a 150 dm3 inner volume. In addition, a second intercomparison of radon detectors was conducted at NIRS with a 24.4 m3 inner volume walk-in radon chamber. Only etched-track detectors were used during thoron intercomparison as well as three types for the radon intercomparison: etched-track, charcoal and electret. In general, 45 % results for thoron experiment do not differ more than 20 % from the reference value of thoron concentration and 69 % for radon.

  Y Shiroma , N Isa , M Hosoda , A Sorimachi , T Ishikawa , S Tokonami and M. Furukawa
 

Thoron exhalation rates from the ground surface were measured at 57 sites on Okinawa Island, Japan, using a ZnS(Ag) scintillation detector equipped with photomultiplier. The arithmetic means ± SD, median ± SD, minimum and maximum of the rates (unit: Bq m–2 s–1) were estimated to be 1.9 ± 1.4, 1.6 ± 0.3, 0.04 and 6.2, respectively. The soils distributed on the island are generally classified into dark red soils, residual regosols, as well as red and yellow soils. While it was assumed that the soils were originated from the bedrock, recent studies suggested that the main material of dark red soils is the East Asian eolian dust. In the dark red soils area, the exhalation rate is relatively higher than that in the other areas. This suggested that the eolian dust was an enhancer for the environmental thoron concentration on Okinawa Island.

  E Ishikawa , T Ishikawa , Y. S Morita , K Toyonaga , H Yamada , O Takeuchi , T Kinoshita , S Akira , Y Yoshikai and S. Yamasaki
 

Tuberculosis remains a fatal disease caused by Mycobacterium tuberculosis, which contains various unique components that affect the host immune system. Trehalose-6,6'-dimycolate (TDM; also called cord factor) is a mycobacterial cell wall glycolipid that is the most studied immunostimulatory component of M. tuberculosis. Despite five decades of research on TDM, its host receptor has not been clearly identified. Here, we demonstrate that macrophage inducible C-type lectin (Mincle) is an essential receptor for TDM. Heat-killed mycobacteria activated Mincle-expressing cells, but the activity was lost upon delipidation of the bacteria; analysis of the lipid extracts identified TDM as a Mincle ligand. TDM activated macrophages to produce inflammatory cytokines and nitric oxide, which are completely suppressed in Mincle-deficient macrophages. In vivo TDM administration induced a robust elevation of inflammatory cytokines in sera and characteristic lung inflammation, such as granuloma formation. However, no TDM-induced lung granuloma was formed in Mincle-deficient mice. Whole mycobacteria were able to activate macrophages even in MyD88-deficient background, but the activation was significantly diminished in Mincle/MyD88 double-deficient macrophages. These results demonstrate that Mincle is an essential receptor for the mycobacterial glycolipid, TDM.

  K Gotoh , Y Tanaka , A Nishikimi , R Nakamura , H Yamada , N Maeda , T Ishikawa , K Hoshino , T Uruno , Q Cao , S Higashi , Y Kawaguchi , M Enjoji , R Takayanagi , T Kaisho , Y Yoshikai and Y. Fukui
 

Plasmacytoid dendritic cells (pDCs) play a key role in antiviral immunity, but also contribute to the pathogenesis of certain autoimmune diseases, by producing large amounts of type I IFNs. Although activation of pDCs is triggered by engagement of nucleotide-sensing toll-like receptors (TLR) 7 and 9, type I IFN induction additionally requires IB kinase (IKK) –dependent activation of IFN regulatory factor (IRF) 7. However, the signaling pathway mediating IKK- activation is poorly defined. We show that DOCK2, an atypical Rac activator, is essential for TLR7- and TLR9-mediated IFN- induction in pDCs. We found that the exposure of pDCs to nucleic acid ligands induces Rac activation through a TLR-independent and DOCK2-dependent mechanism. Although this Rac activation was dispensable for induction of inflammatory cytokines, phosphorylation of IKK- and nuclear translocation of IRF-7 were impaired in Dock2-deficient pDCs, resulting in selective loss of IFN- induction. Similar results were obtained when a dominant-negative Rac mutant was expressed in wild-type pDCs. Thus, the DOCK2–Rac signaling pathway acts in parallel with TLR engagement to control IKK- activation for type I IFN induction. Owing to its hematopoietic cell-specific expression, DOCK2 may serve as a therapeutic target for type I IFN–related autoimmune diseases.

 
 
 
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