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Doi A, Oketani R, Nawa Y, Fujita K. High-resolution imaging in two-photon excitation microscopy using in situ estimations of the point spread function. BIOMEDICAL OPTICS EXPRESS 2018; 9:202-213. [PMID: 29359097 PMCID: PMC5772575 DOI: 10.1364/boe.9.000202] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2017] [Revised: 12/06/2017] [Accepted: 12/10/2017] [Indexed: 05/06/2023]
Abstract
We present a technique for improving the spatial resolution of two-photon excitation microscopy; our technique combines annular illumination with an in situ estimation of the point spread function (PSF) used for deconvolution. For the in situ estimation of the PSF, we developed a technique called autocorrelation scanning, in which a sample is imaged by the scanning of two excitation foci that are overlapped over various distances. The image series obtained with the variation of the distance between the two foci provides the autocorrelation function of the PSF, which can be used to estimate the PSF at specific positions within a sample. We proved the principle and the effectiveness of this technique through observations of a fluorescent biological sample, and we confirmed that the improvement in the spatial resolution was ~1.7 times that of typical two-photon excitation microscopy by observing a mouse brain phantom at a depth of 200 µm.
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Hayashi Y, Takagi M, Kakihara J, Sakamoto S, Tatsumi H, Doi A, Iwata S, Sugioka K, Yoshiyama M. Impact of simple electrocardiographic markers as predictors for deterioration of left ventricular function in patients with frequent right ventricular apical pacing. Heart Vessels 2017; 33:299-308. [PMID: 28952029 DOI: 10.1007/s00380-017-1052-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/18/2017] [Accepted: 09/22/2017] [Indexed: 11/28/2022]
Abstract
Several trials demonstrated that frequent right ventricular apical pacing (RVAP) was associated with cardiac dysfunction and an increased rate of heart failure hospitalization. However, there are few reports about the 12-lead electrocardiogram (12-ECG) parameters at the time of device implantation to predict deterioration of LVEF in patients with frequent RVAP. We retrospectively studied 115 consecutive patients undergoing pacemaker or implantable cardioverter-defibrillator implantation with RVAP, with rate of ventricular pacing ≥ 40% and LVEF ≥ 50% at the time of implantation. We compared the 12-ECG characteristics at the time of device implantation between patients with deterioration of LVEF (≥ 10% reduction) and those without. Twenty-nine patients (25%) had deteriorated LVEF with a decrease in mean LVEF from 59 to 40% during a median follow-up period of 8.9 [4.6-13.7] years. Multivariate logistic regression analysis showed that cumulative % of ventricular pacing [odds ratio (OR) 1.04 per 1% increase, 95% confidence interval (CI) 1.01-1.09, p = 0.04], notching of baseline paced QRS in limb leads (OR 5.04, 95% CI 1.59-19.6, p = 0.005) and the QS pattern in all precordial leads (OR 3.56, 95% CI 1.21-10.8, p = 0.02) were independently associated with deterioration of LVEF. The QS pattern of baseline paced QRS in all precordial leads had 58% sensitivity, 93% specificity for the RV lead position at the tip of RV apex. In conclusion, considering OR by multivariate analysis, notching of baseline paced QRS in limb leads and the QS pattern in all precordial leads at device implantation may be simple and useful predictors to identify patients who are at risk for deterioration of cardiac function during long-term RVAP. 12-ECG monitoring at device implantation and avoidance of the RVAP site showing a QS pattern may be important to prevent deterioration of cardiac function in patients with frequent RVAP.
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Doi A, Takagi M, Kakihara J, Hayashi Y, Tatsumi H, Fujimoto K, Yoshiyama M. P474Diagnostic value of electrocardiographic P-wave characteristics in tachycardia-induced cardiomyopathy. Europace 2017. [DOI: 10.1093/ehjci/eux141.197] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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Doi A, Takagi M, Kakihara J, Hayashi Y, Tatsumi H, Fujimoto K, Sugioka K, Yoshiyama M. Incidence and predictors of silent cerebral thromboembolic lesions after catheter ablation for atrial fibrillation in patients treated with direct oral anticoagulants. Heart Vessels 2017; 32:1227-1235. [PMID: 28466408 DOI: 10.1007/s00380-017-0985-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/08/2016] [Accepted: 04/28/2017] [Indexed: 11/28/2022]
Abstract
There are few reports about the incidence and predictors of silent cerebral thromboembolic lesions (SCLs) after atrial fibrillation (AF) ablation in patients treated with direct oral anticoagulants (DOACs). The purpose of this study is to evaluate the incidence and predictors of SCLs after AF ablation with cerebral magnetic resonance imaging (C-MRI) in patients treated with DOACs. We enrolled 117 consecutive patients who underwent first AF ablation and received DOACs, including apixaban, dabigatran, edoxaban, and rivaroxaban. DOACs were discontinued after administration 24 h before the procedure, and restarted 6 h after the procedure. During the procedure, activated clotting time (ACT) was measured every 15 min, and intravenous heparin infusion was performed to maintain ACT at 300-350 s. All patients underwent C-MRI the day after the procedure. SCLs were detected in 28 patients (24%) after AF ablation. Age, female sex, the presence of persistent AF, left atrial volume, procedure time, radiofrequency energy, electrical cardioversion, and mean ACT showed no correlations with the incidence of SCLs. Multivariate analysis revealed independent predictors of SCLs were CHA2DS2VASc scores ≥3, left atrial appendage (LAA) emptying velocity ≤39 cm/s, and minimum ACT ≤260 s. Patients with both CHA2DS2VASc scores ≥3 and LAA flow velocity ≤39 cm/s had the highest incidence of SCLs 15 of 26 patients (58%). In patients treated with DOACs, CHA2DS2VASc score ≥3, minimum ACT ≤260 s, and LAA emptying velocity ≤39 cm/s were independent risk factors for the SCLs after AF ablation.
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Miyamoto K, Doi A, Amaya N, Morita Y, Noda T, Asakura M, Hamasaki T, Tada H, Takagi M, Yasuda S, Kusano K. A multicenter study of the need of additional freezing for cryoballoon ablation in patients with atrial fibrillation: The AD-Balloon study. J Arrhythm 2017; 33:81-85. [PMID: 28416971 PMCID: PMC5388036 DOI: 10.1016/j.joa.2016.06.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2016] [Revised: 06/14/2016] [Accepted: 06/27/2016] [Indexed: 11/14/2022] Open
Abstract
Background Pulmonary vein isolation (PVI) is a cornerstone of catheter ablation in patients with paroxysmal atrial fibrillation (PAF), and balloon-based ablation has been recently performed worldwide. Ablation using the second-generation cryoballoon (CB2) (Arctic Front AdvanceTM, Medtronic, MN, USA) is useful for PVI; however, there is some debate concerning the optimal freezing time and number of cycles after PVI is achieved. Methods The AD-Balloon study was designed as a prospective, multicenter, randomized clinical trial to evaluate the optimal strategy (freezing cycles) of CB2 ablation (UMIN Clinical Trials Registry UMIN000020130). The main objective of this study is to investigate the need for an additional freezing cycle after PVI in patients treated with CB2 ablation. Patients will be randomly assigned in a 1:1 ratio to treatment with additional freezing (AD group) or without additional freezing (non-AD group). In the AD group, 3 min of additional freezing time will be applied in all pulmonary veins after PVI is confirmed at the previous freezing cycle. In the non-AD group, no additional freezing will be applied in all pulmonary veins after PVI is confirmed. The primary endpoint of this study is the occurrence of atrial tachyarrhythmias within a 1-year follow-up period. We will enroll 110 consecutive patients with PAF. We will also investigate the usefulness of delayed-enhancement magnetic resonance imaging to assess the ablation lesions caused by CB2 ablation. Results The results of this study are currently under investigation. Conclusion The AD-Balloon study would assess the need for an additional freezing cycle after PVI is achieved. Our findings may contribute to further improvement of the CB2 ablation procedure.
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Kakihara J, Takagi M, Hayashi Y, Tatsumi H, Doi A, Yoshiyama M. Utility of 12-lead and signal-averaged Holter electrocardiograms after pilsicainide provocation for risk stratification in Brugada syndrome. Heart Vessels 2017; 32:1151-1159. [DOI: 10.1007/s00380-017-0973-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/10/2016] [Accepted: 03/24/2017] [Indexed: 11/27/2022]
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Yamagata K, Doi A, Kawata H, Makimoto H, Yokoyama T, Inoue Y, Okamura H, Noda T, Shimizu W, Aihara N, Maki T, Kamakura S, Kusano K, Satomi K. Persistent tachycardia within isolated pulmonary veins during atrial fibrillation ablation. Heart Vessels 2017; 32:1006-1012. [PMID: 28283739 DOI: 10.1007/s00380-017-0963-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/06/2016] [Accepted: 02/24/2017] [Indexed: 10/20/2022]
Abstract
During circumferential pulmonary vein (PV) isolation for ongoing atrial fibrillation (AF), distinguishing passive conduction to the pulmonary vein (PV) from rapid PV arrhythmia in the isolated PV is difficult. Hence, the purpose of this study is to investigate both the feasibility of distinguishing the PV tachycardia after circumferential PV isolation and the electrophysiological characteristics of these tachycardia. Among 178 consecutive patients who underwent circumferential PV isolation during ongoing AF, fibrillatory PV converted to a regular cycle length PV tachycardia independent of the atrial rhythm (=independent PV tachycardia) in 13 PVs among 12 (7%) patients. We classified independent PV tachycardia according to 3 different atrial rhythms: sinus rhythm (type 1, n = 2), atrial tachycardia (type 2, n = 4), and AF (type 3, n = 6). independent PV tachycardia was observed in 3 right PV and 10 left PV (P = 0.0864). There were 10 mappable independent PV tachycardia, in which 8 were focal and 2 were macroreentrant tachycardia. i-PVT can be diagnosed in a small number of patients who underwent circumferential PV isolation during AF. The main mechanism or independent PV tachycardia was focal tachycardia mainly in the left PV.
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Oketani R, Doi A, Smith NI, Nawa Y, Kawata S, Fujita K. Saturated two-photon excitation fluorescence microscopy with core-ring illumination. OPTICS LETTERS 2017; 42:571-574. [PMID: 28146530 DOI: 10.1364/ol.42.000571] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
We demonstrated resolution improvement in two-photon excitation microscopy by combining saturated excitation (SAX) of fluorescence and pupil manipulation. We theoretically estimated the resolution improvement and the sidelobe effect in the point spread function with various pupil designs and found that the combination of SAX and core-ring illumination can effectively enhance the spatial resolution in 3D and suppress sidelobe artifacts. The experimental demonstration shows that the proposed technique is effective for observation with a depth of 100 μm in a tissue phantom and can be applied to 3D observations of tissue samples with higher spatial resolution than conventional two-photon excitation microscopy.
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Sugiyama D, Joshi A, Kulkeaw K, Tan KS, Yokoo-Inoue T, Mizuochi-Yanagi C, Yasuda K, Doi A, Iino T, Itoh M, Nagao-Sato S, Tani K, Akashi K, Hayashizaki Y, Suzuki H, Kawaji H, Carninci P, Forrest ARR. A Transcriptional Switch Point During Hematopoietic Stem and Progenitor Cell Ontogeny. Stem Cells Dev 2017; 26:314-327. [PMID: 27848279 DOI: 10.1089/scd.2016.0194] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
During mammalian embryogenesis, hematopoietic stem and progenitor cells (HSPCs) originate from mesoderm-derived endothelial cells in the aorta-gonad-mesonephros (AGM) region and placenta (PL). Later, HSPCs expand in fetal liver (FL) and migrate to bone marrow (BM) shortly before birth. Understanding global transcriptional regulation governing HSPC emergence from embryonic stem/induced pluripotent stem cells is necessary to devise clinical applications, such as novel transplantation approaches. In this study, to assess transcriptional dynamics during development, we performed cap analysis of gene expression on 10 developmental murine HSPC populations isolated from the AGM region, PL, FL, and BM and identified 15,681 transcripts across HSPC ontogeny. We performed microarray analysis of AGM-derived HSPCs at 9.5 and 10.5 days postcoitum (dpc) and identified 40 differentially expressed genes, 23 confirmed as significantly changed by real-time polymerase chain reaction. We conclude that a transcriptional switch point occurs in HSPC ontogeny between 9.5 and 10.5 dpc in the AGM region.
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Doi A, Bando H, Kawazoe A, Fukuoka S, Kuboki Y, Shitara K, Okamoto W, Kojima T, Doi T, Ohtsu A, Yoshino T. 180P Clinical outcome of anal squamous cell carcinoma treated with chemoradiotherapy with 5-fluorouracil plus mitomycin C. Ann Oncol 2016. [DOI: 10.1016/s0923-7534(21)00338-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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Doi A, Bando H, Kawazoe A, Fukuoka S, Kuboki Y, Shitara K, Okamoto W, Kojima T, Doi T, Ohtsu A, Yoshino T. 180P Clinical outcome of anal squamous cell carcinoma treated with chemoradiotherapy with 5-fluorouracil plus mitomycin C. Ann Oncol 2016. [DOI: 10.1093/annonc/mdw581.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Matsunaga N, Ikeda E, Kakimoto K, Watanabe M, Shindo N, Tsuruta A, Ikeyama H, Hamamura K, Higashi K, Yamashita T, Kondo H, Yoshida Y, Matsuda M, Ogino T, Tokushige K, Itcho K, Furuichi Y, Nakao T, Yasuda K, Doi A, Amamoto T, Aramaki H, Tsuda M, Inoue K, Ojida A, Koyanagi S, Ohdo S. Inhibition of G0/G1 Switch 2 Ameliorates Renal Inflammation in Chronic Kidney Disease. EBioMedicine 2016; 13:262-273. [PMID: 27745900 PMCID: PMC5264248 DOI: 10.1016/j.ebiom.2016.10.008] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2015] [Revised: 10/05/2016] [Accepted: 10/05/2016] [Indexed: 12/20/2022] Open
Abstract
Chronic kidney disease (CKD) is a global health problem, and novel therapies to treat CKD are urgently needed. Here, we show that inhibition of G0/G1 switch 2 (G0s2) ameliorates renal inflammation in a mouse model of CKD. Renal expression of chemokine (C-C motif) ligand 2 (Ccl2) was increased in response to p65 activation in the kidneys of wild-type 5/6 nephrectomy (5/6Nx) mice. Moreover, 5/6Nx Clk/Clk mice, which carry homozygous mutations in the gene encoding circadian locomotor output cycles kaput (CLOCK), did not exhibit aggravation of apoptosis or induction of F4/80-positive cells. The renal expression of G0s2 in wild-type 5/6Nx mice was important for the transactivation of Ccl2 by p65. These pathologies were ameliorated by G0s2 knockdown. Furthermore, a novel small-molecule inhibitor of G0s2 expression was identified by high-throughput chemical screening, and the inhibitor suppressed renal inflammation in 5/6Nx mice. These findings indicated that G0s2 inhibitors may have applications in the treatment of CKD.
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Sakamoto S, Takagi M, Kakihara J, Hayashi Y, Doi A, Sugioka K, Yoshiyama M. The utility of T-wave alternans during the morning in the summer for the risk stratification of patients with Brugada syndrome. Heart Vessels 2016; 32:341-351. [PMID: 27480879 DOI: 10.1007/s00380-016-0882-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/24/2016] [Accepted: 07/22/2016] [Indexed: 02/06/2023]
Abstract
The prognostic value of the seasonal variations of T-wave alternans (TWA) and heart rate variability (HRV), and the seasonal distribution of ventricular fibrillation (VF) in Brugada syndrome (Br-S) is unknown. We assessed the utility of seasonal variations in TWA and HRV for risk stratification in Br-S using a 24-h multichannel Holter electrocardiogram (24-M-ECG). We enrolled 81 patients with Br-S (grouped according to their history of VF, n = 12; syncope, n = 8; no symptoms, n = 61) who underwent 24-M-ECG in all four seasons. Precordial electrodes were attached to the third (3L-V2) and fourth (4L-V2, 4L-V5) intercostal spaces. We determined the maximum TWA (max-TWA) values and calculated HRV during night and morning time periods for all seasons. During a follow-up period of 5.8 ± 2.8 years, 11 patients experienced new VF episodes and there was a peak in new VF episodes in the summer. The VF group had the greatest 3L-V2 max-TWA value during morning time in the summer among the three groups and showed higher 3L-V2 max-TWA value than in the other seasons. The cutoff value for the 3L-V2 max-TWA during morning time in the summer was determined to be 42 µV using ROC analysis (82 % sensitivity, 74 % specificity; p = 0.0006). Multivariate analysis revealed that a 3L-V2 max-TWA value ≥42 µV during morning time in the summer and previous VF episodes were predictors of future VF episodes. The 3L-V2 max-TWA value during morning time in the summer may be a useful predictor of future VF episodes in Br-S.
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Doi A, Takagi M, Fujimoto K, Kakihara J, Hayashi Y, Tatsumi H, Yoshiyama M. Long RP' Tachycardia With Unusual Entrainment Responses: What Is the Mechanism? J Cardiovasc Electrophysiol 2016; 27:1242-1244. [PMID: 27090609 DOI: 10.1111/jce.12987] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/07/2016] [Accepted: 04/13/2016] [Indexed: 11/29/2022]
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Kakihara J, Takagi M, Hayashi Y, Tatsumi H, Doi A, Yoshiyama M. Radiofrequency catheter ablation for treatment of premature ventricular contractions triggering ventricular fibrillation from the right ventricular outflow tract in a patient with early repolarization syndrome. HeartRhythm Case Rep 2016; 2:342-346. [PMID: 28491706 PMCID: PMC5419889 DOI: 10.1016/j.hrcr.2016.04.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
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Iwata K, Doi A, Nakamura T, Yoshida H. The validity of three sputum smears taken in one day for discontinuing isolation of tuberculosis patients. Int J Tuberc Lung Dis 2016; 19:918-20. [PMID: 26162357 DOI: 10.5588/ijtld.15.0159] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
We conducted a retrospective comparative study of acid-fast bacilli (AFB) smear sensitivity according to time of specimen collection to assess whether three consecutive AFB smears collected in 1 day are useful when deciding to discontinue respiratory isolation of patients with pulmonary tuberculosis (TB). A total of 236 sputum specimens from 119 patients with pulmonary TB were used for the analysis. There was no statistical difference in AFB smear sensitivity of early-morning sputum and those collected later (P = 0.186). This may allow us to collect all specimens in a single day and discontinue respiratory isolation of TB patients earlier.
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Hamamura K, Matsunaga N, Ikeda E, Kondo H, Ikeyama H, Tokushige K, Itcho K, Furuichi Y, Yoshida Y, Matsuda M, Yasuda K, Doi A, Yokota Y, Amamoto T, Aramaki H, Irino Y, Koyanagi S, Ohdo S. Alterations of Hepatic Metabolism in Chronic Kidney Disease via D-box-binding Protein Aggravate the Renal Dysfunction. J Biol Chem 2016; 291:4913-27. [PMID: 26728457 DOI: 10.1074/jbc.m115.696930] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2015] [Indexed: 11/06/2022] Open
Abstract
Chronic kidney disease (CKD) is associated with an increase in serum retinol; however, the underlying mechanisms of this disorder are poorly characterized. Here, we found that the alteration of hepatic metabolism induced the accumulation of serum retinol in 5/6 nephrectomy (5/6Nx) mice. The liver is the major organ responsible for retinol metabolism; accordingly, microarray analysis revealed that the hepatic expression of most CYP genes was changed in 5/6Nx mice. In addition, D-box-binding protein (DBP), which controls the expression of several CYP genes, was significantly decreased in these mice. Cyp3a11 and Cyp26a1, encoding key proteins in retinol metabolism, showed the greatest decrease in expression in 5/6Nx mice, a process mediated by the decreased expression of DBP. Furthermore, an increase of plasma transforming growth factor-β1 (TGF-β1) in 5/6Nx mice led to the decreased expression of the Dbp gene. Consistent with these findings, the alterations of retinol metabolism and renal dysfunction in 5/6Nx mice were ameliorated by administration of an anti-TGF-β1 antibody. We also show that the accumulation of serum retinol induced renal apoptosis in 5/6Nx mice fed a normal diet, whereas renal dysfunction was reduced in mice fed a retinol-free diet. These findings indicate that constitutive Dbp expression plays an important role in mediating hepatic dysfunction under CKD. Thus, the aggravation of renal dysfunction in patients with CKD might be prevented by a recovery of hepatic function, potentially through therapies targeting DBP and retinol.
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Fujioka J, Doi A, Okuyama D, Morikawa D, Arima T, Okada KN, Kaneko Y, Fukuda T, Uchiyama H, Ishikawa D, Baron AQR, Kato K, Takata M, Tokura Y. Ferroelectric-like metallic state in electron doped BaTiO3. Sci Rep 2015; 5:13207. [PMID: 26289749 PMCID: PMC4542543 DOI: 10.1038/srep13207] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2015] [Accepted: 07/16/2015] [Indexed: 12/05/2022] Open
Abstract
We report that a ferroelectric-like metallic state with reduced anisotropy of polarization is created by the doping of conduction electrons into BaTiO3, on the bases of x-ray/electron diffraction and infrared spectroscopic experiments. The crystal structure is heterogeneous in nanometer-scale, as enabled by the reduced polarization anisotropy. The enhanced infrared intensity of soft phonon along with the resistivity reduction suggests the presence of unusual electron-phonon coupling, which may be responsible for the emergent ferroelectric structure compatible with metallic state.
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Sugioka K, Takagi M, Sakamoto S, Fujita S, Ito A, Iwata S, Matsumura Y, Nakagawa M, Doi A, Miki Y, Yoshiyama M, Ueda M. Predictors of silent brain infarction on magnetic resonance imaging in patients with nonvalvular atrial fibrillation: A transesophageal echocardiographic study. Am Heart J 2015; 169:783-90. [PMID: 26027615 DOI: 10.1016/j.ahj.2015.03.016] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/11/2014] [Accepted: 03/18/2015] [Indexed: 11/27/2022]
Abstract
BACKGROUND Silent brain infarction (SBI) is often found in patients with atrial fibrillation (AF) and may be related to cognitive decline. We investigated the predictors of SBI on brain magnetic resonance imaging (MRI) using transesophageal echocardiography (TEE) in patients with nonvalvular AF. METHODS The study population consisted of 103 neurologically asymptomatic patients with nonvalvular AF who underwent TEE before transcatheter AF ablation (76 men; mean age 63 ± 10 years). Left atrial (LA) abnormalities such as LA thrombus, spontaneous echo contrast, or abnormal LA appendage emptying velocity (<20 cm/s) and complex plaques in the aortic arch defined as large plaques ≥4 mm thickness, ulcerated plaques, or mobile plaques were evaluated by TEE. All patients were screened for SBI by brain MRI. RESULTS Of 103 patients, 31 (30%) showed SBI on brain MRI. Most lesions were multiple (61%) and small (<15 mm) in diameter (84%). Patients with SBI had a higher prevalence of LA abnormalities (45% vs 14%; P < .001) and complex arch plaques (45% vs 7%; P < .001) compared with those without SBI. In a multivariate logistic regression analysis including age and CHADS2 score ≥2, LA abnormalities (odds ratio 4.13; 95% CI 1.34-12.72; P = .014) and complex arch plaques (odds ratio 4.82; 95% CI 1.23-18.92; P = .024) were independent predictors of SBI. CONCLUSIONS Left atrial abnormalities and complex arch plaques detected by TEE were closely associated with the presence of SBI on brain MRI, suggesting that microembolization of small thrombi derived from the fibrillating LA or advanced aortic atherosclerotic lesions may be important causes of SBI in patients with nonvalvular AF.
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Sakamoto S, Takagi M, Tatsumi H, Doi A, Sugioka K, Hanatani A, Yoshiyama M. Utility of T-wave alternans during night time as a predictor for ventricular fibrillation in patients with Brugada syndrome. Heart Vessels 2015; 31:947-56. [PMID: 25989739 DOI: 10.1007/s00380-015-0692-y] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/06/2015] [Accepted: 05/08/2015] [Indexed: 10/23/2022]
Abstract
The prognostic value of T-wave alternans (TWA) during the night time in patients with Brugada syndrome (Br-S) remains unknown. We assessed TWA for risk stratification using 24-h multichannel Holter electrocardiogram (24-M-ECG) in Br-S. We enrolled 129 patients with Br-S [grouped according to histories of ventricular fibrillation (VF), n = 16; syncope, n = 10; or no symptoms (asymptomatic), n = 103] and 11 controls. Precordial electrodes were attached to the third (3L-V1, 3L-V2) and fourth (4L-V1, 4L-V2 and 4L-V5) intercostal spaces. We measured the values of maximum TWA (max-TWA) during the night time (12 a.m.-6 a.m.) and the day time (12 p.m.-6 p.m.) and calculated parameters of heart rate variability. Compared to the asymptomatic and control groups, the VF and syncope groups showed significantly greater 3L-V2 max-TWA during the night time. The cutoff value for the 3L-V2 max-TWA during the night time was determined as 20 µV (sensitivity 94 % and specificity 48 %; p = 0.01). Multivariate analysis revealed that 3L-V2 max-TWA during the night time ≥20 µV and previous VF episodes were independent predictors of future VF episodes. During a mean follow-up period of 68 ± 37 months, 16 patients experienced VF episodes. The incidence of VF episodes was the highest during the night time (p < 0.001). The 3L-V2 max-TWA during the night time may be a useful predictor for VF episodes in patients with Br-S.
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Kinjyo I, Qin J, Tan SY, Wellard CJ, Mrass P, Ritchie W, Doi A, Cavanagh LL, Tomura M, Sakaue-Sawano A, Kanagawa O, Miyawaki A, Hodgkin PD, Weninger W. Real-time tracking of cell cycle progression during CD8+ effector and memory T-cell differentiation. Nat Commun 2015; 6:6301. [PMID: 25709008 PMCID: PMC4346633 DOI: 10.1038/ncomms7301] [Citation(s) in RCA: 108] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2014] [Accepted: 01/15/2015] [Indexed: 01/08/2023] Open
Abstract
The precise pathways of memory T-cell differentiation are incompletely understood. Here we exploit transgenic mice expressing fluorescent cell cycle indicators to longitudinally track the division dynamics of individual CD8+ T cells. During influenza virus infection in vivo, naive T cells enter a CD62Lintermediate state of fast proliferation, which continues for at least nine generations. At the peak of the anti-viral immune response, a subpopulation of these cells markedly reduces their cycling speed and acquires a CD62Lhi central memory cell phenotype. Construction of T-cell family division trees in vitro reveals two patterns of proliferation dynamics. While cells initially divide rapidly with moderate stochastic variations of cycling times after each generation, a slow-cycling subpopulation displaying a CD62Lhi memory phenotype appears after eight divisions. Phenotype and cell cycle duration are inherited by the progeny of slow cyclers. We propose that memory precursors cell-intrinsically modulate their proliferative activity to diversify differentiation pathways. CD8+ memory T cells appear during infection via a process of selection and differentiation that remains poorly understood. Using a fluorescent indicator of cell cycle progression, Kinjyo et al. show that slow-cycling memory precursors are derived from fast-cycling-activated T cells in influenza-infected mice.
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Doi A, Lee G, Snell G, Bloch M, Summerhayes R, Marasco S. Lung transplantation as rescue therapy in patients too sick to be discharged from acute care. Transplant Proc 2015; 46:256-9. [PMID: 24507062 DOI: 10.1016/j.transproceed.2013.08.107] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2013] [Accepted: 08/19/2013] [Indexed: 11/16/2022]
Abstract
BACKGROUND There is an increasing demand for lung transplantation in patients in advanced respiratory failure. Although many of these patients do not require mechanical ventilation or extracorporeal membrane oxygenation, an increasing number are critically ill. In this single-center study, we have analyzed our experience with lung transplantation in subjects who were inpatients at the time of their transplant and not expected to survive to discharge. METHODS Between July 2006 and March 2012, we performed 274 bilateral sequential lung transplants and 34 single-lung transplants. Twenty-six patients who were inpatients at the time of their transplant, and were not expected to survive to hospital discharge, formed the inpatient group in this retrospective review. The remaining 281 outpatient lung transplant patients formed the comparison group. RESULTS The inpatient group spent significantly fewer days on the waiting list compared to the outpatient group. Postoperative survival was significantly poorer in the inpatient group compared to the outpatient group (P = .001), and this was most noticeable in the first 90 days. There was no significant difference in survival between the inpatient transplant cohort and a historically comparable wait list cohort (P = .614). CONCLUSION Lung transplantation in critically ill inpatients, although associated with a survival advantage compared to not transplanting them, does give poorer survival results compared to postoperative survival in outpatient patients.
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Koch H, Caughie C, Elsen FP, Doi A, Garcia AJ, Zanella S, Ramirez JM. Prostaglandin E2 differentially modulates the central control of eupnoea, sighs and gasping in mice. J Physiol 2014; 593:305-19. [PMID: 25556802 DOI: 10.1113/jphysiol.2014.279794] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2014] [Accepted: 09/24/2014] [Indexed: 01/10/2023] Open
Abstract
Prostaglandin E2 (PGE2) augments distinct inspiratory motor patterns, generated within the preBötzinger complex (preBötC), in a dose-dependent way. The frequency of sighs and gasping are stimulated at low concentrations, while the frequency of eupnoea increases only at high concentrations. We used in vivo microinjections into the preBötC and in vitro isolated brainstem slice preparations to investigate the dose-dependent effects of PGE2 on the preBötC activity. Synaptic measurements in whole cell voltage clamp recordings of inspiratory neurons revealed no changes in inhibitory or excitatory synaptic transmission in response to PGE2 exposure. In current clamp recordings obtained from inspiratory neurons of the preBötC, we found an increase in the frequency and amplitude of bursting activity in neurons with intrinsic bursting properties after exposure to PGE2. Riluzole, a blocker of the persistent sodium current, abolished the effect of PGE2 on sigh activity, while flufenamic acid, a blocker of the calcium-activated non-selective cation conductance, abolished the effect on eupnoeic activity caused by PGE2. Prostaglandins are important regulators of autonomic functions in the mammalian organism. Here we demonstrate in vivo that prostaglandin E2 (PGE2) can differentially increase the frequency of eupnoea (normal breathing) and sighs (augmented breaths) when injected into the preBötzinger complex (preBötC), a medullary area that is critical for breathing. Low concentrations of PGE2 (100-300 nm) increased the sigh frequency, while higher concentrations (1-2 μm) were required to increase the eupnoeic frequency. The concentration-dependent effects were similarly observed in the isolated preBötC. This in vitro preparation also revealed that riluzole, a blocker of the persistent sodium current (INap), abolished the modulatory effect on sighs, while flufenamic acid, an antagonist for the calcium-activated non-selective cation conductance (ICAN ) abolished the effect of PGE2 on fictive eupnoea at higher concentrations. At the cellular level PGE2 significantly increased the amplitude and frequency of intrinsic bursting in inspiratory neurons. By contrast PGE2 affected neither excitatory nor inhibitory synaptic transmission. We conclude that PGE2 differentially modulates sigh, gasping and eupnoeic activity by differentially increasing INap and ICAN currents in preBötC neurons.
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74
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Sugioka K, Fujita S, Iwata S, Ito A, Matsumura Y, Hanatani A, Doi A, Takagi M, Naruko T, Ueda M, Yoshiyama M. Relationship between CHADS2 score and complex aortic plaques by transesophageal echocardiography in patients with nonvalvular atrial fibrillation. ULTRASOUND IN MEDICINE & BIOLOGY 2014; 40:2358-2364. [PMID: 25023106 DOI: 10.1016/j.ultrasmedbio.2014.05.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/04/2014] [Revised: 04/16/2014] [Accepted: 05/07/2014] [Indexed: 06/03/2023]
Abstract
The CHADS2 score is widely used for risk stratification of thromboembolism in patients with non-valvular atrial fibrillation (NVAF). Although the correlation of CHADS2 score with left atrial (LA) abnormality as detected by transesophageal echocardiography (TEE) has been reported in previous studies, the relationship between CHADS2 score and complex aortic plaque, which is also a significant risk factor for thromboembolism, has not been fully investigated. We assessed aortic plaques by TEE in 150 patients age ≥ 55 y with NVAF. The prevalence of complex aortic plaques increased along with increases in CHADS2 score (p = 0.001). In a multivariate analysis that included atherosclerotic risk factors and LA abnormality, a CHADS2 score ≥2 was independently associated with the presence of complex aortic plaques (odds ratio [OR] 3.39; 95% confidence interval [CI], 1.29-8.90). A high CHADS2 score is closely associated with the presence of complex aortic plaques, which explains, in part, the increased risk of thromboembolism in NVAF patients with high CHADS2 score.
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Kogawa T, Doi A, Shimokawa M, Fouad TM, Osuga T, Tamura F, Mizushima T, Kimura T, Abe S, Ihara H, Kukitsu T, Sumiyoshi T, Yoshizaki N, Hirayama M, Sasaki T, Kawarada Y, Kitashiro S, Okushiba S, Kondo H, Tsuji Y. Early skin toxicity predicts better outcomes, and early tumor shrinkage predicts better response after cetuximab treatment in advanced colorectal cancer. Target Oncol 2014; 10:125-33. [PMID: 24859798 DOI: 10.1007/s11523-014-0322-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2014] [Accepted: 05/09/2014] [Indexed: 12/11/2022]
Abstract
Cetuximab-containing treatments for metastatic colorectal cancer have been shown to have higher overall response rates and longer progression-free and overall survival than other systemic therapies. Cetuximab-related manifestations, including severe skin toxicity and early tumor shrinkage, have been shown to be predictors of response to cetuximab. We hypothesized that early skin toxicity is a predictor of response and better outcomes in patients with advanced colorectal carcinoma. We retrospectively evaluated 62 patients with colorectal adenocarcinoma who had unresectable tumors and were treated with cetuximab in our institution. Skin toxicity grade was evaluated on each treatment day. Tumor size was evaluated using computed tomography prior to treatment and 4-8 weeks after the start of treatment with cetuximab.Patients with early tumor shrinkage after starting treatment with cetuximab had a significantly higher overall response rate (P = 0.0001). Patients with early skin toxicity showed significantly longer overall survival (P = 0.0305), and patients with higher skin toxicity grades had longer progression-free survival (P = 0.0168).We have shown that early tumor shrinkage, early onset of skin toxicity, and high skin toxicity grade are predictors of treatment efficacy and/or outcome in patients with advanced colorectal carcinoma treated with cetuximab.
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76
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Blanchard F, Sumida K, Wolpert C, Tsotsalas M, Tanaka T, Doi A, Kitagawa S, Cooke DG, Furukawa S, Tanaka K. Terahertz phase contrast imaging of sorption kinetics in porous coordination polymer nanocrystals using differential optical resonator. OPTICS EXPRESS 2014; 22:11061-11069. [PMID: 24921804 DOI: 10.1364/oe.22.011061] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The enhancement of light-matter coupling when light is confined to wavelength scale volumes is useful both for studying small sample volumes and increasing the overall sensing ability. At these length scales, nonradiative interactions are of key interest to which near-field optical techniques may reveal new phenomena facilitating next-generation material functionalities and applications. Efforts to develop novel chemical or biological sensors using metamaterials have yielded innovative ideas in the optical and terahertz frequency range whereby the spatially integrated response over a resonator structure is monitored via the re-radiated or leaked light. But although terahertz waves generally exhibit distinctive response in chemical molecules or biological tissue, there is little absorption for subwavelength size sample and therefore poor image contrast. Here, we introduce a method that spatially resolves the differential near-field phase response of the entire resonator as a spectral fingerprint. By simultaneously probing two metallic ring resonators, where one loaded with the sample of interest, the differential phase response is able to resolve the presence of guest molecules (e.g. methanol) as they are adsorbed or released within the pores of a prototypical porous coordination polymer.
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Iwata K, Doi A, Fukuchi T. Actual status and future prospects of Infectious Diseases Fellowship in Japan: a qualitative study. Int J Infect Dis 2014. [DOI: 10.1016/j.ijid.2014.03.739] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
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Ramirez JM, Doi A, Garcia AJ, Elsen FP, Koch H, Wei AD. The cellular building blocks of breathing. Compr Physiol 2013; 2:2683-731. [PMID: 23720262 DOI: 10.1002/cphy.c110033] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Respiratory brainstem neurons fulfill critical roles in controlling breathing: they generate the activity patterns for breathing and contribute to various sensory responses including changes in O2 and CO2. These complex sensorimotor tasks depend on the dynamic interplay between numerous cellular building blocks that consist of voltage-, calcium-, and ATP-dependent ionic conductances, various ionotropic and metabotropic synaptic mechanisms, as well as neuromodulators acting on G-protein coupled receptors and second messenger systems. As described in this review, the sensorimotor responses of the respiratory network emerge through the state-dependent integration of all these building blocks. There is no known respiratory function that involves only a small number of intrinsic, synaptic, or modulatory properties. Because of the complex integration of numerous intrinsic, synaptic, and modulatory mechanisms, the respiratory network is capable of continuously adapting to changes in the external and internal environment, which makes breathing one of the most integrated behaviors. Not surprisingly, inspiration is critical not only in the control of ventilation, but also in the context of "inspiring behaviors" such as arousal of the mind and even creativity. Far-reaching implications apply also to the underlying network mechanisms, as lessons learned from the respiratory network apply to network functions in general.
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Viemari JC, Garcia AJ, Doi A, Elsen G, Ramirez JM. β-Noradrenergic receptor activation specifically modulates the generation of sighs in vivo and in vitro. Front Neural Circuits 2013; 7:179. [PMID: 24273495 PMCID: PMC3824105 DOI: 10.3389/fncir.2013.00179] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2013] [Accepted: 10/23/2013] [Indexed: 11/13/2022] Open
Abstract
The pre-Bötzinger complex (preBötC), an area that is critical for generating breathing (eupnea), gasps and sighs is continuously modulated by catecholamines. These amines and the generation of sighs have also been implicated in the regulation of arousal. Here we studied the catecholaminergic modulation of sighs not only in anesthetized freely breathing mice (in vivo), but also in medullary slice preparations that contain the preBötC and that generate fictive eupneic and sigh rhythms in vitro. We demonstrate that activating β-noradrenergic receptors (β-NR) specifically increases the frequency of sighs, while eupnea remains unaffected both in vitro and in vivo. β-NR activation specifically increased the frequency of intrinsically bursting pacemaker neurons that rely on persistent sodium current (I(Nap)). By contrast, all parameters of bursting pacemakers that rely on the non-specific cation current (I(CAN)) remained unaffected. Moreover, riluzole, which blocks bursting in I(Nap) pacemakers abolished sighs altogether, while flufenamic acid (FFA) which blocks the I(CAN) current did not alter the sigh-increasing effect caused by β-NR. Our results suggest that the selective β-NR action of sighs may result from the modulation of I(Nap) pacemaker activity and that disturbances in noradrenergic system may contribute to abnormal arousal response. The β-NR action on the preBötC may be an important mechanism in modulating behaviors that are specifically associated with sighs, such as the regulation of the early events leading to the arousal response.
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Ogasawara M, Yuda S, Hoshi Y, Nozawa Y, Sato M, Kouzu H, Nishihara M, Doi A, Nishimiya T, Miura T. Atrial electromechanical interval may predict cardioembolic stroke in apparently low risk patients with paroxysmal atrial fibrillation. Eur Heart J 2013. [DOI: 10.1093/eurheartj/eht308.2023] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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81
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Hoshi Y, Nozawa Y, Ogasawara M, Yuda S, Sato S, Sakasai T, Oka M, Katayama H, Sato M, Kouzu H, Nishihara M, Doi A, Nishimiya T, Miura T. Atrial electromechanical interval may predict cardioembolic stroke in apparently low risk elderly patients with paroxysmal atrial fibrillation. Echocardiography 2013; 31:140-8. [PMID: 23906195 DOI: 10.1111/echo.12329] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
BACKGROUND A considerable number of patients with atrial fibrillation (AF) develop cardioembolic stroke (CE) despite low CHADS2 score. We examined the possibility that use of the atrial electromechanical interval (AEMI) improves prediction of CE in patients with paroxysmal AF (PAF), particularly those with low CHADS2 score. METHODS We consecutively enrolled 108 patients with nonvalvular PAF and 52 healthy subjects as controls. The PAF patients were divided into 2 groups depending on presence (n = 36) or absence (n = 72) of the history of CE. Left atrial (LA) volume index (LAVI), peak myocardial velocity during late diastole (a'), and AEMI as time from onset of P-wave to onset of lateral a' were measured. RESULTS Patients with PAF had significantly larger LAVI, longer AEMI, and lower lateral a' than those in controls. Area under the curves for LAVI, lateral a', and AEMI for identifying patients with PAF were 0.70, 0.69, and 0.88, respectively. Multivariate logistic regression analysis indicated that age, use of antiarrhythmic drugs, and AEMI, but not LAVI or a', were independently associated with history of CE in patients with PAF. PAF patients were categorized into low risk by CHADS2 score (i.e. CHADS2 score = 0 or 1, n = 60), those with prolonged AEMI (>82 msec) had significantly higher rates of CE than those with ≤ 82 msec (48% vs. 15%, P < 0.05). CONCLUSION As compared with echocardiographic parameters of LA size and LA function, AEMI appears to be more useful for identifying PAF patients. AEMI may enable to detect high risk PAF patients, especially those categorized into low risk by CHADS2 score.
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Haga S, Tsuchiya H, Hara K, Doi A, Mimori A, Ishizaka Y. THU0056 A Small Chemical Compound Identified as an ACE2 Activator Prevented Pulmonary Arterial Hypertension Induced by Monocrotaline. Ann Rheum Dis 2013. [DOI: 10.1136/annrheumdis-2013-eular.584] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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83
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Doi A, Satomi K, Makimoto H, Yokoyama T, Yamada Y, Okamura H, Noda T, Aiba T, Aihara N, Yasuda S, Ogawa H, Kamakura S, Shimizu W. Efficacy of additional radiofrequency applications for spontaneous dissociated pulmonary vein activity after pulmonary vein isolation in patients with paroxysmal atrial fibrillation. J Cardiovasc Electrophysiol 2013; 24:894-901. [PMID: 23601079 DOI: 10.1111/jce.12153] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/05/2013] [Revised: 03/07/2013] [Accepted: 03/08/2013] [Indexed: 11/28/2022]
Abstract
BACKGROUND The aim is to evaluate the efficacy of additional radiofrequency ablation (RFCA) for spontaneous dissociated pulmonary vein activity (DPV-spike) after PV isolation (PVI) in patients with paroxysmal atrial fibrillation (AF). METHODS One hundred fifty-two consecutive patients with paroxysmal AF referred for RFCA were enrolled. When DPV-spike was documented after PVI, we randomly assigned these patients to receive additional RFCA for DPV-spike or only PVI. We divided them into 4 groups: 87 patients without DPV-spike after PVI (No-spike group), 31 without DPV-spike after additional RFCA (Successful group), 8 with remaining DPV-spike after additional RFCA (Unsuccessful group), and 26 with DPV-spike after only PVI (Spike group). AF recurrence was evaluated among the 4 groups. RESULTS After PVI, DPV-spike was documented in 87 PVs (14%) from 65 patients. During 16 ± 9 months of follow-up, the incidence of the freedom from AF was significantly higher in the No-spike group than that in the Spike group and Unsuccessful group (P < 0.05), and tended to be higher in the Successful group than that in the Spike group and Unsuccessful group (P = 0.08 and 0.11, respectively). In a multivariate analysis, the remaining PV-spike after ablation was an independent predictor of AF recurrence (HR 2.44; CI 1.10-5.43, P < 0.05). No major complications including PV stenosis were observed during the follow-up. CONCLUSIONS DPV-spike after PVI may be associated with higher electrical activity within the PVs and may be one of the risk factors for AF recurrence. Additional RFCA for DPV-spike was effective to reduce the AF recurrence after PVI.
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Dashevskiy T, Doi A, Ramirez J. The role of ATP and glia in modulating the generation of sighs. FASEB J 2013. [DOI: 10.1096/fasebj.27.1_supplement.931.7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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85
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Sotomi Y, Inoue K, Ito N, Kimura R, Toyoshima Y, Masuda M, Doi A, Iwakura K, Okamura A, Koyama Y, Date M, Fujii K. Cause of very late recurrence of atrial fibrillation or flutter after catheter ablation for atrial fibrillation. Am J Cardiol 2013; 111:552-6. [PMID: 23211357 DOI: 10.1016/j.amjcard.2012.10.040] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/01/2012] [Revised: 10/17/2012] [Accepted: 10/17/2012] [Indexed: 11/25/2022]
Abstract
The major mechanism underlying the early recurrence of atrial fibrillation (AF) after ablation is mainly reconnection of the isolated pulmonary vein (PV); however, the mechanism responsible for very late recurrence (VLR) has not been fully elucidated. The purpose of the present study was to investigate the mechanism underlying VLR. The study population included 150 consecutive patients with AF who underwent a second session of catheter ablation because of recurrence. We divided them into 2 groups according to the point of initial AF recurrence: the late recurrence group (LR group, initial recurrence 3 to 12 months after ablation, n = 124) and the VLR group (initial recurrence >12 months after ablation, n = 26). We identified PVs with ectopic foci (trigger PVs) in the first procedure and checked their electrical reconnection in the second procedure. The prevalence of PV reconnection and trigger PV reconnection were significantly lower in the VLR group than in LR group (LR vs VLR, 90% vs 69% and 48% vs 27%, p = 0.007 and p = 0.045, respectively). In the VLR group, left ventricular systolic and diastolic function were significantly worse than in the LR group, and more patients in the VLR group required non-PV trigger ablation in the second session than did those in the LR group (30% vs 54%, p = 0.034). In conclusion, electrical PV reconnection contributed less to VLR than to LR. Progression of the AF substrate might be an important mechanism responsible for VLR.
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Kino M, Takahara F, Hada K, Doi A. Energy densities of magnetic field and relativistic electrons at the innermost region of the M87 jet. EPJ WEB OF CONFERENCES 2013. [DOI: 10.1051/epjconf/20136101009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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87
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Blanchard F, Ooi K, Tanaka T, Doi A, Tanaka K. Near-field terahertz imaging of a discontinuity in split ring resonator array. EPJ WEB OF CONFERENCES 2013. [DOI: 10.1051/epjconf/20134109006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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88
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Masuda M, Inoue K, Iwakura K, Okamura A, Toyoshima Y, Doi A, Sotomi Y, Komuro I, Fujii K. Impact of pulmonary vein isolation on atrial late potentials: association with the recurrence of atrial fibrillation. ACTA ACUST UNITED AC 2012; 15:501-7. [DOI: 10.1093/europace/eus326] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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89
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Hirotani Y, Doi A, Ikeda K, Kato R, Ijiri Y, Tanaka K, Myotoku M. Effects of Gosha-jinki-gan (Chinese herbal medicine: Niu-Che-Sen-Qi-Wan) on hyperinsulinemia induced in rats fed a sucrose-rich diet. Drug Discov Ther 2012; 5:181-4. [PMID: 22466298 DOI: 10.5582/ddt.2011.v5.4.181] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
We investigated the effects of a Chinese herbal medicine, Gosha-jinki-gan (GJG), on the regulation of insulin levels in rats fed a sucrose-rich diet (SRD). Normal Wistar rats in the SRD group were fed an SRD for 4 weeks. Increased dietary sucrose did not alter plasma glucose levels but it increased plasma insulin levels at 2 and 4 weeks in the SRD-fed rats relative to control rats that were fed standard chow. GJG treatment significantly suppressed the SRD-induced elevation in plasma insulin levels. These results suggest that GJG improves hyperinsulinemia caused by an SRD.
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Toyoshima Y, Inoue K, Kimura R, Doi A, Masuda M, Sotomi Y, Iwakura K, Fujii K. A case of repetitive nonreentrant ventriculoatrial synchrony exacerbating heart failure in dilated cardiomyopathy. J Arrhythm 2012. [DOI: 10.1016/j.joa.2012.07.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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91
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Blanchard F, Ooi K, Tanaka T, Doi A, Tanaka K. Terahertz spectroscopy of the reactive and radiative near-field zones of split ring resonator. OPTICS EXPRESS 2012; 20:19395-19403. [PMID: 23038582 DOI: 10.1364/oe.20.019395] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
A terahertz microscope has been used to excite and observe the resonant modes of a single split ring resonator in the reactive and radiative near-field zones. The two lowest resonant modes of an isolated split ring resonator with their corresponding radiation patterns are reported; they showed good agreement to simulations. The passage from the reactive to radiative near-field zone is also discussed. Further, our result introduced a novel technique to perform terahertz time-domain spectroscopy of samples a few tens of micrometers in size by measuring the in-plane radiative near-field zone.
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Masuda M, Inoue K, Iwakura K, Okamura A, Koyama Y, Kimura R, Toyoshima Y, Doi A, Sotomi Y, Komuro I, Fujii K. Preprocedural ventricular rate predicts subsequent sick sinus syndrome after ablation for long-standing persistent atrial fibrillation. PACING AND CLINICAL ELECTROPHYSIOLOGY: PACE 2012; 35:1074-80. [PMID: 22817381 DOI: 10.1111/j.1540-8159.2012.03477.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND Concealed sick sinus syndrome may become manifest after restoration of sinus rhythm by ablation in patients with long-standing persistent atrial fibrillation (AF). The purpose of this study was to investigate the association between the preprocedural ventricular rate during AF and sinus node function in patients with long-standing persistent AF. METHODS Consecutive patients (n = 102) who underwent ablation for long-standing persistent AF were enrolled. We measured the ventricular rate during AF before ablation in the absence of antiarrhythmic drugs. Sinus node function was assessed by electrophysiological study and serial Holter recordings after ablation. RESULTS Patients in the lowest quartile of ventricular rate during AF had longer corrected sinus node recovery time (1.06 ± 1.39 seconds) than those in the other quartiles (0.54 ± 0.31 seconds; P = 0.006) and lower mean heart rate on 24-hour Holter recording 3 months after ablation (68 ± 9 beats/min vs 75 ± 10 beats/min, P = 0.01). During a mean follow-up of 23 ± 10 months, sick sinus syndrome necessitating permanent pacemaker implantation developed in five (5%) patients, and multivariate analysis revealed that a low ventricular rate during AF rate was an independent risk factor for sick sinus syndrome (odds ratio = 0.90 for a 1 beat/min increase in AF rate, P = 0.04). CONCLUSIONS A low preprocedural ventricular rate during AF indicates the existence of sinus node dysfunction after restoration of sinus rhythm by ablation in patients with long-standing persistent AF.
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Miyata S, Kawabata S, Hiramatsu R, Doi A, Ikeda N, Yamashita T, Kuroiwa T, Kasaoka S, Maruyama K, Miyatake SI. Computed tomography imaging of transferrin targeting liposomes encapsulating both boron and iodine contrast agents by convection-enhanced delivery to F98 rat glioma for boron neutron capture therapy. Neurosurgery 2012; 68:1380-7; discussion 1387. [PMID: 21273928 DOI: 10.1227/neu.0b013e31820b52aa] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND To achieve potent tumor-selective antitumor efficacy by boron neutron capture therapy (BNCT), it is important to have a significant differential uptake of 10B between tumor cells and normal cells. This should enable BNCT to reduce damage to normal tissues compared with other radiation therapies. OBJECTIVE To augment the therapeutic efficacy of BNCT, we used transferrin-conjugated polyethylene glycol (PEG) (TF-PEG) liposome encapsulating sodium borocaptate and Iomeprol, an iodine contrast agent, with intratumoral convection-enhanced delivery (CED) in a rat glioma tumor model. METHODS The in vitro (10)B concentration of F98 rat glioma cells was determined by inductively coupled plasma atomic emission spectrometry after incubation with either TF-PEG or PEG liposomes. For in vivo biodistribution studies, (10)B concentrations within blood, normal brain tissue, and intracerebrally transplanted F98 cells were measured with inductively coupled plasma-atomic emission spectrometry after CED of the compounds, and computed tomography was performed at selected time intervals. RESULTS (10)B concentrations of F98 cultured glioma cells in vitro 6 hours after exposure to PEG and TF-PEG liposome were 16.1 and 51.9 ng (10)B/10(6) cells, respectively. (10)B concentrations in F98 glioma tissue 24 hours after CED were 22.5 and 82.2 μg/g, by PEG and TF-PEG liposome, respectively, with lower (10)B concentrations in blood and normal brain. Iomeprol provided vivid and stable enhanced computed tomography imaging of the transplanted tumor even 72 hours after CED by TF-PEG liposome. Conversely, tissue enhancement had already washed out at 24 hours after CED of the PEG liposomes. CONCLUSION The combination of TF-PEG liposome encapsulating sodium borocaptate and Iomeprol and intratumoral CED enables not only a precise and potent targeting of boron delivery to the tumor tissue, but also the ability to follow the trace of boron delivery administered intratumorally by real-time computed tomography.
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Garcia AJ, Doi A, Malashchenko T, Wei A, Kumar G, Prabhakar N, Ramirez JM. Chronic Intermittent Hypoxia (CIH) alters respiratory rhythmogenesis within the preBötzinger Complex. FASEB J 2012. [DOI: 10.1096/fasebj.26.1_supplement.899.2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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95
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Toyoshima Y, Inoue K, Kimura R, Doi A, Masuda M, Sotomi Y, Iwakura K, Okamura A, Koyama Y, Date M, Higuchi Y, Ozawa M, Takagi T, Omiya S, Morisawa D, Nakatani S, Sumiyoshi A, Nozato Y, Fujii K. IMPROVEMENT OF MITRAL REGURGITATION AFTER CATHETER ABLATION FOR ATRIAL FIBRILLATION. J Am Coll Cardiol 2012. [DOI: 10.1016/s0735-1097(12)60612-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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96
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Masuda M, Iwakura K, Inoue K, Okamura A, Koyama Y, Kimura R, Doi A, Toyoshima Y, Komuro I, Fujii K. Estimation of Left Atrial Pump Function by Mitral Annular Velocity. Circ J 2012; 76:1430-5. [DOI: 10.1253/circj.cj-12-0010] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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97
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Komatsu N, Matsueda S, Tashiro K, Ioji T, Shichijo S, Noguchi M, Yamada A, Doi A, Suekane S, Moriya F, Matsuoka K, Kuhara S, Itoh K, Sasada T. Gene expression profiles in peripheral blood as a biomarker in cancer patients receiving peptide vaccination. Cancer 2011; 118:3208-21. [PMID: 22071976 DOI: 10.1002/cncr.26636] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2011] [Revised: 08/26/2011] [Accepted: 09/16/2011] [Indexed: 12/12/2022]
Abstract
BACKGROUND Because only a subset of patients show clinical responses to peptide-based cancer vaccination, it is critical to identify biomarkers for selecting patients who would most likely benefit from this treatment. METHODS The authors characterized the gene expression profiles in peripheral blood of vaccinated patients to identify biomarkers to predict patient prognosis. Peripheral blood was obtained from advanced castration-resistant prostate cancer patients, who survived for >900 days (long-term survivors, n = 20) or died within 300 days (short-term survivors, n = 20) after treatment with personalized peptide vaccination. Gene expression profiles in prevaccination and postvaccination peripheral blood mononuclear cells (PBMCs) were assessed by DNA microarray. RESULTS There were no statistically significant differences in the clinical or pathological features between the 2 groups. Microarray analysis of prevaccination PBMCs identified 19 genes that were differentially expressed between the short-term and long-term survivors. Among the 15 up-regulated genes in the short-term survivors, 13 genes, which were also differentially expressed in postvaccination PBMCs, were associated with gene signatures of granulocytes. When a set of 4 differentially expressed genes were selected as the best combination to determine patient survival, prognosis was correctly predicted in 12 of 13 patients in a validation set (accuracy, 92%). CONCLUSIONS These results suggested that abnormal granulocytes present in the PBMC faction may contribute to poor prognosis in advanced prostate cancer patients receiving personalized peptide vaccination. Gene expression profiling in peripheral blood might thus be informative for devising better therapeutic strategies by predicting patient prognosis after cancer vaccines.
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Doi A, Satomi K, Okamura H, Noda T, Aiba T, Shimizu W, Aihara N, Kamakura S, Baez-Escudero JL, Dave AS, Sasaridis CM, Valderrabano M, Nitsche B, Braunschweig F, Gaspar T, Doering M, Richter S, Eitel C, Hindricks G, Piorkowski C, Kelemen K, Lugenbiel P, Bikou O, Becker R, Katus HA, Thomas D, Askar SFA, Ramkisoensing AA, Schalij MJ, Bingen BO, Van Der Laarse A, Atsma DE, Ypey DL, Pijnappels DA, Jeevaratnam K, Rewbury R, Zhang Y, Guzadhur L, Grace AA, Lei M, Huang CLH. Young Investigator Awards Session. Europace 2011. [DOI: 10.1093/europace/eur226] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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99
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Viemari JC, Garcia AJ, Doi A, Ramirez JM. Activation of alpha-2 noradrenergic receptors is critical for the generation of fictive eupnea and fictive gasping inspiratory activities in mammals in vitro. Eur J Neurosci 2011; 33:2228-37. [PMID: 21615559 DOI: 10.1111/j.1460-9568.2011.07706.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Biogenic amines are not just 'modulators', they are often essential for the execution of behaviors. Here, we explored the role of biogenic amines acting on the pre-Bötzinger complex (pre-BötC), an area located in the ventrolateral medulla which is critical for the generation of different forms of breathing. Isolated in transverse slices from mice, this region continues to spontaneously generate rhythmic activities that resemble normal (eupneic) inspiratory activity in normoxia and gasping in hypoxia. We refer to these as 'fictive eupneic' and 'fictive gasping' activity. When exposed to hypoxia, the pre-BötC transitions from a network state relying on calcium-activated nonspecific cation currents (I(CAN)) and persistent sodium currents (I(Nap)) to one that primarily depends on the I(Nap) current. Here we show that in inspiratory neurons I(Nap)-dependent bursting, blocked by riluzole, but not I(CAN) -dependent bursting, required endogenously released norepinephrine acting on alpha2-noradrenergic receptors (α2-NR). At the network level, fictive eupneic activity persisted while fictive gasping ceased following the blockade of α2-NR. Blockade of α2-NR eliminated fictive gasping even in slice preparations as well as in inspiratory island preparations. Blockade of fictive gasping by α2-NR antagonists was prevented by activation of 5-hydroxytryptamine type 2A receptors (5-HT2A). Our data suggest that gasping depends on the converging aminergic activation of 5-HT2AR and α2-NR acting on riluzole-sensitive mechanisms that have been shown to be crucial for gasping.
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100
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Blanchard F, Doi A, Tanaka T, Hirori H, Tanaka H, Kadoya Y, Tanaka K. Real-time terahertz near-field microscope. OPTICS EXPRESS 2011; 19:8277-8284. [PMID: 21643077 DOI: 10.1364/oe.19.008277] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
We report a terahertz near-field microscope with a high dynamic range that can capture images of a 370 x 740 μm2 area at 35 frames per second. We achieve high spatial resolution (14 μm corresponding to λ/30 for a center frequency at 0.7 THz) on a large area by combining two novel techniques: terahertz generation by tilted-pulse-front excitation and electro-optic balanced imaging detection using a thin crystal. To demonstrate the microscope capability, we reveal the field enhancement at the gap position of a dipole antenna after the irradiation of a terahertz pulse.
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