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Dive into the research topics where Sanae Kaga is active.

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Featured researches published by Sanae Kaga.


Coronary Artery Disease | 2006

Increased plasma concentrations of N-terminal pro-brain natriuretic peptide reflect the presence of mildly reduced left ventricular diastolic function in hypertension.

Tomoo Furumoto; Satoshi Fujii; Taisei Mikami; Mamiko Inoue; Keiko Nishihara; Sanae Kaga; Shogo Imagawa; Kazutomo Goto; Kaoru Komuro; Satoshi Yamada; Hisao Onozuka; Akira Kitabatake; Burton E. Sobel

BackgroundThe potential use of assays of N-terminal pro-brain natriuretic peptide for detection of diastolic abnormalities associated with alterations in blood pressure has not been elucidated. This study was designed to determine whether increased plasma concentrations of N-terminal pro-brain natriuretic peptide sensitively reflect abnormal diastolic function associated with hypertension. MethodsConcentrations of N-terminal pro-brain natriuretic peptide in plasma were assayed in 40 previously untreated hypertensive patients without overt congestive heart failure and in 20 age and sex-matched controls. Hypertensive patients were studied with the use of pulsed Doppler and color M-mode Doppler echocardiography for the evaluation of left ventricular diastolic function. ResultsConcentrations of N-terminal pro-brain natriuretic peptide were elevated in hypertensive patients [75.1±75.2 (SD) pg/ml compared with 37.9±38.5 in controls, P<0.05]. In hypertensive patients, concentrations of N-terminal pro-brain natriuretic peptide were negatively correlated with the ratio of color M-mode flow propagation velocity to transmitral E velocity consistent with the view that increased concentrations of N-terminal pro-brain natriuretic peptide are indicative of alterations in diastolic function. Hypertensive patients with N-terminal pro-brain natriuretic peptide values above the mean value in the control group exhibited significantly increased brachial intimal–medial thickness and reduced wall stress, consistent with the view that increased N-terminal pro-brain natriuretic peptide was associated with favorable peripheral arterial remodeling. ConclusionsElevated concentrations of N-terminal pro-brain natriuretic peptide in plasma reflect the presence of left ventricular diastolic abnormalities and peripheral arterial remodeling in asymptomatic patients with hypertension.


Circulation | 2015

Myocardial Shortening in 3 Orthogonal Directions and Its Transmural Variation in Patients With Nonobstructive Hypertrophic Cardiomyopathy

Kazunori Okada; Satoshi Yamada; Hiroyuki Iwano; Hisao Nishino; Masahiro Nakabachi; Shinobu Yokoyama; Ayumu Abe; Ayako Ichikawa; Sanae Kaga; Mutsumi Nishida; Taichi Hayashi; Daisuke Murai; Taisei Mikami; Hiroyuki Tsutsui

BACKGROUND Although longitudinal strain (LS) is known to be reduced in patients with hypertrophic cardiomyopathy (HCM), it has not been elucidated whether or not circumferential strain (CS) is reduced. We aimed to determine whether multidirectional and layer-specific myocardial strain is reduced in patients with nonobstructive HCM. METHODSANDRESULTS Speckle-tracking echocardiography was performed in 41 HCM patients and 27 control subjects. Segmental and global LS and CS were measured in the inner, mid, and outer layers. Global LS was significantly lower in the HCM group than in controls in the inner (-10.3±2.9 vs. -14.8±2.0%, P<0.001), mid (-8.7±2.6 vs. -13.8±1.9%, P<0.001), and outer (-7.2±2.6 vs. -11.9±1.9%, P<0.001) layers. Global CS was preserved in the inner layer (-23.8±4.7 vs. -24.3±3.3%, P=0.69) but reduced in the mid (-10.3±3.1 vs. -13.3±2.5%, P<0.001) and outer layers (-6.7±2.3 vs. -8.6±2.3%, P=0.002). Differences in CS between the inner and outer layers correlated with segmental relative wall thickness (r=-0.20, P=0.002). Furthermore, only the absolute value of global CS in the inner layer positively correlated with left ventricular ejection fraction (r=0.32, P<0.01) among these multidirectional and layer-specific strains. CONCLUSIONS In patients with HCM, not only the LS in all layers but also CS in the mid and outer layers was reduced, presumably reflecting impaired myocardial function. In contrast, CS in the inner layer was preserved, being associated with maintenance of chamber function.


Journal of Clinical Laboratory Analysis | 2018

Quantitative distinction of the morphological characteristic of erythrocyte precursor cells with texture analysis using gray level co-occurrence matrix

Keigo Kono; Ruka Hayata; Satoru Murakami; Mai Yamamoto; Maiko Kuroki; Kana Nanato; Kazuto Takahashi; Keiko Miwa; Yutaka Tsutsumi; Kazunori Okada; Sanae Kaga; Taisei Mikami; Nobuo Masauzi

Morphological characteristics of blood cells are still qualitatively defined. So a texture analysis (Tx) method using gray level co‐occurrence matrices (GLCMs; CM‐Tx method) was applied to images of erythrocyte precursor cells (EPCs) for quantitatively distinguishing four types of EPC stages: proerythroblast, basophilic erythroblast, polychromatic erythroblast, and orthochromatic erythroblast.


European Journal of Echocardiography | 2018

Novel echocardiographic method to assess left ventricular chamber stiffness and elevated end-diastolic pressure based on time–velocity integral measurements of pulmonary venous and transmitral flows

Kazunori Okada; Sanae Kaga; Rika Abiko; Michito Murayama; Takuma Hioka; Masahiro Nakabachi; Shinobu Yokoyama; Hisao Nishino; Ayako Ichikawa; Ayumu Abe; Mutsumi Nishida; Naoya Asakawa; Shingo Tsujinaga; Taichi Hayashi; Hiroyuki Iwano; Satoshi Yamada; Nobuo Masauzi; Taisei Mikami

Aims The detection of increased left ventricular (LV) chamber stiffness may play an important role in assessing cardiac patients with potential but not overt heart failure. A non-invasive method to estimate it is not established. We investigated whether the echocardiographic backward/forward flow volume ratio from the left atrium (LA) during atrial contraction reflects the LV chamber stiffness. Methods and results We studied 62 patients who underwent cardiac catheterization and measured their left ventricular end-diastolic pressure (LVEDP) and pressure increase during atrial contraction (ΔPa) from the LV pressure waveform. Using the echocardiographic biplane method of disks, we measured the LV volume change during atrial contraction indexed to the body surface area (ΔVa), and ΔPa/ΔVa was calculated as a standard for the LV operating chamber stiffness. Using pulsed Doppler echocardiography, we measured the time-velocity integral (TVI) of the backward pulmonary venous (PV) flow during atrial contraction (IPVA) and the ratio of IPVA to the PV flow TVI throughout a cardiac cycle (FPVA). We also measured the TVI of the atrial systolic forward transmitral flow (IA) and the ratio of the IA to the transmitral TVI during a cardiac cycle (FA) and calculated IPVA/IA and FPVA/FA. IPVA/IA and FPVA/FA were well correlated with ΔPa/ΔVa (r = 0.79 and r = 0.81) and LVEDP (r = 0.73 and r = 0.77). The areas under the ROC curve to discriminate LVEDP >18 mmHg were 0.90 for IPVA/IA and 0.93 for FPVA/FA. Conclusion The FPVA/FA, the backward/forward flow volume ratio from the LA during atrial contraction, is useful for non-invasive assessments of LV chamber stiffness and elevated LVEDP.


Journal of Clinical Laboratory Analysis | 2017

Semi‐Automatic Rating Method for Neutrophil Alkaline Phosphatase Activity

Kanae Sugano; Kotomi Hashi; Misaki Goto; Kiyotaka Nishi; Rie Maeda; Keigo Kono; Mai Yamamoto; Kazunori Okada; Sanae Kaga; Keiko Miwa; Taisei Mikami; Nobuo Masauzi

The neutrophil alkaline phosphatase (NAP) score is a valuable test for the diagnosis of myeloproliferative neoplasms, but it has still manually rated. Therefore, we developed a semi‐automatic rating method using Photoshop® and Image‐J, called NAP‐PS‐IJ.


Journal of Clinical Laboratory Analysis | 2016

Semiautomated Segmentation and Measurement of Cytoplasmic Vacuoles in a Neutrophil With General‐Purpose Image Analysis Software

Maki Mizukami; Misaki Yamada; Sayaka Fukui; Nao Fujimoto; Shigeru Yoshida; Sanae Kaga; Keiko Obata; Shigeki Jin; Keiko Miwa; Nobuo Masauzi

Morphological observation of blood or marrow film is still described nonquantitatively. We developed a semiautomatic method for segmenting vacuoles from the cytoplasm using Photoshop (PS) and Image‐J (IJ), called PS‐IJ, and measured the relative entire cell area (rECA) and relative areas of vacuoles (rAV) in the cytoplasm of neutrophil with PS‐IJ.


Journal of Medical Ultrasonics | 2017

Altered oscillation of Doppler-derived renal and renal interlobar venous flow velocities in hypertensive and diabetic patients

Yusuke Kudo; Taisei Mikami; Mutsumi Nishida; Kazunori Okada; Sanae Kaga; Nobuo Masauzi; Satomi Omotehara; Hitoshi Shibuya; Kaoru Kahata; Chikara Shimizu

Background and purposeFlow velocity oscillation rate (FVOR) of the renal interlobar vein has been reported to be decreased in patients with urinary obstruction or diabetic nephropathy, and increased in those with hypertension during pregnancy. To clarify the clinical role of the renal interlobar venous FVOR, we investigated the flow velocity patterns of the renal vessels in patients with hypertension (HT) and/or diabetes (DM).Methods and resultsPulsed-wave Doppler sonography was performed in 34 patients: 15 with HT, 10 with DM, and nine with both HT and DM (HT-DM). Each FVOR of the right and left interlobar veins was closely and positively correlated with the ipsilateral interlobar arterial resistive index (RI), especially in the HT group, but not with the estimated glomerular filtration rate. The right interlobar venous FVOR was decreased in the DM and HT-DM groups compared to the HT group.ConclusionThe renal interlobar venous FVOR is strongly influenced by the arterial RI in HT patients, and is reduced in DM patients without an obvious relationship with diabetic nephropathy. These findings should be noted for the clinical application of renal interlobar venous flow analysis.


Clinical Laboratory | 2017

Quantitative Distinction of Morphological Characteristics of White Blood Cells in Peripheral Blood Through Texture Analysis Using Gray Level Co-Occurrence Matrix

Mai Yamamoto; Keigo Kono; Maiko Kuroki; Satoru Murakami; Ruka Hayata; Kana Nanato; Minrong Shao; Keiko Miwa; Yutaka Tsutsumi; Kazunori Okada; Sanae Kaga; Nobuo Masauzi

BACKGROUND Texture features are valuable clues for skilled technicians to differentiate peripheral blood (PB) white blood cells (WBCs). Some studies have tried to distinguish WBCs automatically by using texture analysis. However, no study so far has applied a gray level co-occurrence matrix (GLCM) to images of PB WBCs. Here, we developed a new GLCM method, called the CM-Tx method, for automatically distinguishing PB WBCs. METHODS We used a total of 199 images of six different types of PB WBCs, taken from PB smears of 12 healthy volunteers, as objective standard images for the analysis. The six types were band form neutrophil, segmented form neutrophil, eosinophil, basophil, lymphocyte, and monocyte. Using in-house FORTRAN programs, three types of GLCM (R: distance (d) = 1, direction (θ) = 0°), (U: d = 1, θ = 270°) and (AE: d = 1, θ = 15° x q: q = 0, ..., 23), the mean intensity (MI) of each image and nine different texture distinction indexes (TDIs) for each GLCM were calculated. Then, a threshold value (TV) for distinguishing the type of PB WBC was selected from the dot plots of all TDIs and the MI. RESULTS In total, we made 1,194 GLCMs. Using the selected TVs of the TDI, four sequential binary divisions could distinguish five types of PB WBCs. First, monocytes were distinguished (sensitivity 100%, specificity 100%, p < 0.0001) with the TV of the inverse difference moment of the GLCM (U). Then, segmented and band form neutrophils were distinguished from the remaining (100%, 99%, p < 0.0001) with the TV of the contrast of the GLCM (AE). Next, lymphocytes were distinguished (100%, 98%, p < 0.0001) with the TV of the entropy of the GLCM (AE). Finally, basophils were distinguished (82.4%, 100%, p < 0.0001) from eosinophils with the TV of the summed entropy of the GLCM (R). Band form neutrophils could not be distinguished from segmented form neutrophils. The average sensitivity of the CM-Tx method for the five types was 95.6%, and its average specificity was 99.3%. CONCLUSIONS The CM-Tx method can distinguish five types of PB WBCs by using numerical differences only in texture futures quantified with GLCM. However, some other method was needed to distinguish the band and segmented form neutrophils from each other.


Journal of Clinical Ultrasound | 2014

Decreased aorto-septal angle may contribute to left ventricular diastolic dysfunction in healthy subjects

Kazunori Okada; Taisei Mikami; Sanae Kaga; Masahiro Nakabachi; Ayumu Abe; Shinobu Yokoyama; Hisao Nishino; Mutsumi Nishida; Chikara Shimizu; Hiroyuki Iwano; Satoshi Yamada; Hiroyuki Tsutsui

Left ventricular (LV) diastolic dysfunction is often observed in healthy older subjects without structural heart disease, although its exact mechanisms have not been established. A decrease in the aorto‐septal angle (ASA), an alteration of LV shape due to aortic elongation, is also frequently seen in elderly subjects. The objective of this study was to evaluate whether it can contribute to LV diastolic dysfunction in healthy subjects.


European Journal of Echocardiography | 2011

Early diastolic mitral annular velocity at the interventricular septal annulus correctly reflects left ventricular longitudinal myocardial relaxation

Kazunori Okada; Taisei Mikami; Sanae Kaga; Hisao Onozuka; Mamiko Inoue; Shinobu Yokoyama; Hisao Nishino; Mutsumi Nishida; Kazuhiko Matsuno; Hiroyuki Iwano; Satoshi Yamada; Hiroyuki Tsutsui

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