218 research outputs found

    Electrochemical surface plasmon resonance as a probe of redox reactions at the ionic liquid|gold interface

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    Electrochemical surface plasmon resonance (ESPR) has been employed as a probe of redox reactions at the interface between gold (Au) and ionic liquid (IL). Two redox couples, ferrocene (Fc)/Fc⁺ and (ferrocenylmethyl)trimethylammonium (FTA⁺)/FTA²⁺, and two ILs, trioctylmethylammonium bis(trifluoromethanesulfonyl)amide ([TOMA⁺][C₁C₁N⁻]) have been studied. In the ESPR measurements, the shift of the SPR angle has been recorded simultaneously with cyclic voltammogram (CV). It has been revealed that the SPR angle shift reproduces CV when the former is semi-differentiated or the latter is semi-integrated, and, therefore, that the ESPR response probes the surface concentration of redox couples at the IL|Au interface. Among the four combination of the two redox couples and the two ILs, the case for Fc/Fc⁺ in [TOMA⁺][C₁C₁N⁻] shows significantly greater ESPR response than the other three cases. A model has been established for the relationship between the SPR angle shift and the surface concentration of redox species. The model predicts that the SPR angle shift becomes pronounced with increasing DR/DO, the diffusion coefficient ratio of the reduced (R) and oxidized (O) species when the reduced species is initially dissolved in the IL as is the case for the present study. Significantly greater DR/DO for Fc/Fc⁺ in [TOMA⁺][C₁C₁N⁻] than the three other cases has been confirmed from the DR and DO measurements by CV with a microdisk electrode. The trend of the measured DR and DO values agrees with recent findings by researchers that small neutral solutes in ILs composed of large ions diffuse fast beyond the prediction of the Stokes-Einstein relation

    Structure and function of tegmentum vasculosum in avian cochlea

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    In spite of the importance of endocochlear DC potential (EP) and the K+-rich endolymph for the avian cochlea, the structure and function of the tegmentum vasculosum (TV) has not yet been fully elucidated, compared with those of the stria vascularis in the mammalian cochlea. In this study, we examined structural analysis of the epithelial cells, gene expressions of Na+-K+-ATPase (Atp1A1) and Kir4.1 (Kcnj10), and protein localizations of Na+-K+-ATPase and Kir4.1, in the TV. Tight junctional structures were observed between epithelial dark cells and light cells in the TV. Both Atp1a1 and Kcnj10 genes were detected in the TV. In addition, immunopositive signals for both Na+-K+-ATPase and Kir4.1 were recognized in the TV. These results indicate that Na+-K+-ATPase and Kir4.1 play roles in maintaining the EP and high K+ concentration of the endolymph. Further studies are needed to clarify the physiological functions of the TV. This is the first report which demonstrates that gene and protein expression data contribute to the avian inner ear homeostasis

    Risk Evaluation for Coronary Artery Disease in Patients With Impaired Glucose Tolerance After a Successful Coronary Intervention

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    信州大学博士(医学)・学位論文・平成23年3月31日授与(甲第880号)・堀込充章This is a non-final version of an article published in final form in CLINICAL NUCLEAR MEDICINE. 36(7):546-552 (2011)Purpose: Patients with coronary artery disease (CAD) often have risk factors that may influence endothelial function. The purpose of this study was to evaluate the endothelial function and its association with coronary risk factors after percutaneous coronary intervention (PCI). Materials and Methods: A total of 14 patients with impaired glucose tolerance and CAD underwent positron emission tomography with N-13 ammonia to measure myocardial blood flow (MBF) at rest and during a cold pressor test (CPT), to estimate endothelial function as a percent increase (%increase) of MBF. The results were compared among normal segments (normal), reperfused segments with PCI (PCI), and nonculprit CAD segments without PCI (non-PCI). Correlations between the %increase and major risk factors were also investigated. Results: CPT induced significant increase in MBF in all groups. The %increase of normal, non-PCI, and PCI groups were 33% +/- 22%, 21% +/- 23%, and 26% +/- 23%, respectively. Comparison with risk factors demonstrated significant correlations only in the non-PCI group. Specifically, there were negative correlations between %increase and fasting blood sugar (r = -0.64, P < 0.05), hemoglobin A1c (r = -0.74, P < 0.05), total cholesterol (r = -0.87, P < 0.05), triglyceride (r = -0.71, P < 0.05), and low-density lipoprotein cholesterol (r = -0.92, P < 0.005), respectively. Conclusions: Although impaired glucose tolerance patients with a PCI-treated coronary stenosis showed preserved response to CPT, the %increase negatively correlated with risk factors in the non-PCI segments. Therefore, coronary risk factors may affect CAD lesions in PCI-treated patients.ArticleCLINICAL NUCLEAR MEDICINE. 36(7):546-552 (2011)journal articl

    Comparative study on the major element chemical compositions of Antarctic chondrites to those of non-Antarctic falls with reference to terrestrial weathering

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    Antarctic ordinary chondrites contain variable amounts of Fe_2O_3 and water as terrestrial weathering products. The Fe_2O_3 contents have a positive correlation with water contents, and a negative correlation with metallic Fe. Therefore, oxygen and water were added to Antarctic chondrites during weathering to form limonitic alteration from metallic iron. Other major elements and total Fe slightly decrease with increasing Fe_2O_3. This decrease is caused by the "dilution" effect due to additional water and oxygen, suggesting that most of the Antarctic chondrites seem to have undergone terrestrial weathering in a quasi-closed system insofar as major elements are concerned. Weathering index has minimal or no relation with the Fe_2O_3 contents of chondrites. Extensive weathering obscures petrographic features of some chondrites, leading to the misclassification, and they are revised on the basis of UC diagram. The major element compositions of Antarctic ordinary chondrites are the same as those of non-Antarctic falls, and they show slight difference in Mg and Na contents among H, L, and LL chondrites; H chondrites have the highest Mg/Si ratio and the lowest Na/Si ratio on average. Some LL chondrite breccias have higher K contents than non-brecciated LL chondrites

    The Protective Effects of Ultraviolet A1 Irradiation on Spontaneous Lupus Erythematosus-Like Skin Lesions in MRL/lpr Mice

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    We investigated the effects of ultraviolet A1 (UVA1) irradiation on spontaneous lupus erythematosus- (LE-) like skin lesions of MRL/lpr mice, using a disease prevention model. UVA1 irradiation significantly inhibited the development of LE-like skin lesions, without obvious changes of the disease including renal disease and serum antinuclear antibody levels. Besides the massive infiltration of mast cells in the LE-like skin lesions, in the nonlesional skins, more mast cells infiltrated in the UVA1-irradiated group compared with the nonirradiated group. Although apoptotic cells were remarkably seen in the dermis of UVA1-irradiated mice, those cells were hardly detectable in the dermis of the nonirradiated mice without skin lesions. Further analysis showed that some of those apoptotic cells were mast cells. Thus, UVA1 might exert its effects, at least in part, through the induction of the apoptosis of pathogenic mast cells. Our results supported the clinical efficacy of UVA1 irradiation for skin lesions of lupus patients

    乳癌術前化学療法において腋窩リンパ節転移が陰性化するための効果予測因子の検討

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    Purpose: We investigated the role of tumor-infiltrating lymphocytes (TILs) in pretreatment primary breast cancer to predict pathological response to neoadjuvant chemotherapy (NAC) in patients with clinical node-positive disease (cN +). Methods: The subjects of this study were 60 patients with cN + , who received NAC followed by breast surgery with axillary lymph node dissection (ALND). We conducted a semi-quantitative assessment of TILs in pretreatment primary tumors and their association with clinicopathological factors and axillary lymph node metastasis. Results: We observed a higher number of TILs in tumors with negative hormone receptors, positive human epidermal growth factor receptor 2, or high Ki67. TILs were associated with a favorable response to NAC in primary tumors. The rate of axillary pathologic complete response (Ax-pCR) was significantly higher in patients with a high number of TILs than in patients with a low number of TILs (72.0% versus 17.1%, p < 0.001). In multivariable analysis, a high number of TILs was a significant predictor of Ax-pCR as well as of pCR of the primary tumor after NAC. Importantly, all patients with HER2-positive tumors in the high TILs group showed Ax-pCR on ALND. Conclusion: TILs in pretreatment primary breast cancer had the potential to predict therapeutic efficacy of NAC in patients with clinical node-positive disease.博士(医学)・乙第1498号・令和3年3月15日© Springer Nature Singapore Pte Ltd. 2020This is a post-peer-review, pre-copyedit version of an article published in Surgery today. The final authenticated version is available online at: https://doi.org/10.1007/s00595-020-02157-6

    無症候性腎機能障害が結腸癌術後の臨床経過に及ぼす影響

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    Purpose: To evaluate the effect of mild renal dysfunction on the clinical course after colectomy in patients with colon cancer. Methods: The subjects of this retrospective study were 263 patients who underwent surgical resection for colon cancer at our hospital between 2011 and 2015. Renal function was assessed based on preoperative estimated glomerular filtration rate (eGFR) values. Patients were divided into groups based on their eGFR value of 55 ml/min/1.73 m2. The Mann-Whitney U test, chi-square or Fisher exact test, and log-rank test were used in the data analysis. Results: There were 59 patients (22.4%) in the low eGFR group and 204 patients in the normal eGFR group. There were differences between the groups in age, comorbidities, and the levels of hemoglobin, albumin, and serum creatinine. The overall postoperative complication rate, frequency of severe complications, and length of stay were significantly higher in the low eGFR group than in the normal eGFR group. Multivariate analysis revealed that low eGFR was the only independent risk factor for severe complications (Clavien-Dindo classification III/IV). There were no differences in survival between the groups. Conclusion: Preoperative asymptomatic renal dysfunction may be correlated with the development of postoperative complications and a possible significant risk factor for severe complications after colon cancer surgery.博士(医学)・甲第804号・令和3年12月21日© 2021. Springer Nature Singapore Pte Ltd.The version of record of this article, first published in Surgery Today, is available online at Publisher’s website: http://dx.doi.org/10.1007/s00595-021-02363-w.発行元が定める登録猶予期間終了の後、本文を登録予定(2021.01

    Nodal Merkel Cell Carcinoma in Head and Neck Lesions with an Unknown Primary: A Case Report in Light of the Literature

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    Merkel cell carcinoma (MCC) is a rare but aggressive neuroendocrine skin cancer. To diagnose nodal MCC with an unknown primary disease is challenging, and it has to be separated from other nodal metastatic neoplasms. We report a unique case of nodal MCC in head and neck lesions with an unknown primary. A 70-year-old woman was admitted to our department with a right submandibular mass. Fine needle aspiration biopsy was performed and indicated malignancy. F-18-fluorodeoxyglucose positron emission tomography (PET) demonstrated abnormal accumulation in the right submandibular lymph node, right palatine tonsil, and right thyroid gland. For diagnostics and treatment, bilateral selective neck lymph node dissection, right tonsillectomy, and right thyroidectomy were performed. Histopathological examination revealed that most parts of the submandibular lymph node were occupied by diffuse sheets of tumor cells. Contrary to our expectation, malignant cells were not detected in the right palatine tonsil and right thyroid. Immunohistochemistry demonstrated a marked positive reaction for AE1/AE3, chromogranin A, synaptophysin, cytokeratin 20 (CK20) and CD56 and a negative reaction for vimentin, leucocyte common antigen (LCA), thyroid transcription factor-1 (TTF1) and cytokeratin 7 (CK7) in the tumor cells. Immunostaining of Merkel cell polyomavirus-large T antigen (MCPyV-LT) showed a positive reaction and MCPyV-positive MCCs were assessed by PCR analysis, demonstrating that viral copy number was 12.8 copies per cell. These histological findings confirmed the diagnosis of Merkel cell carcinoma of the lymph node. In cases of tumors in the lymph node with a neuroendocrine appearance in head and neck lesions, it is necessary to eliminate the possibility of metastasis from MCC
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