Danfu Ma

Dr. Danfu Ma

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Research Focus & Metrics

Academic Career Length

7Years (2020-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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9 February 2021 in Animals
Verified
Journal Article
Open access
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Hanan HendawyHanan Hendawy
Hanan Hendawy
AUAkiko Uemura
Akiko Uemura
DMDanfu Ma
Danfu Ma
RNRyosuke Namiki
Ryosuke Namiki
Haney SamirHaney Samir
Haney Samir
Ryou TanakaRyou Tanaka
Ryou Tanaka
Mesenchymal stem cells (MSCs) constitute a great promise for regenerative therapy, but these cells are difficultly recovered in large amounts. A potent alternative is the stromal vascular fraction (SVF), non-cultured MSCs, separated from adipose tissue (AT). We aim to evaluate AT harvesting site effect on the SVF cells’ quantity and quality in dogs. Subcutaneous abdominal fat, falciform ligament and peri-ovarian fat were sampled. After SVF isolation, the trypan blue exclusion test and a hemocytometer were used to assess the cell viability and cellular yield. SVF cells were labeled for four surface antigenic markers, clusters of differentiation CD90, CD44, CD29, and CD45, and then examined by flow cytometry. Semi-quantitative RT-PCR was used to evaluate the gene expression of the former markers in addition to OCT-4 and CD34. SVF cells in the peri-ovarian AT recorded the highest viability% (99.63 ± 0.2%), as well as a significantly higher cellular yield (36.87 ± 19.6 × 106 viable cells/gm fat, p < 0.001) and a higher expression of adipose-derived mesenchymal stem cells AD-MSCs surface markers than that of other sites. SVF cells from the peri-ovarian site revealed a higher expression of MSC markers (CD90, CD44, and CD29) and OCT-4 compared to the other sites, with weak CD45 and CD34 expressions. The positive OCT-4 expression demonstrated the pluripotency of SVF cells isolated from different sites. To conclude, the harvesting site is a strong determinant of SVF cells’ quantity and quality, and the peri-ovarian site could be the best AT sampling site in dogs.

3 August 2021 in Diagnostics
Verified
Journal Article
Open access
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AYAkira Yairo
Akira Yairo
Ahmed S. MandourAhmed S. Mandour
Ahmed S. Mandour
KMKatsuhiro Matsuura
Katsuhiro Matsuura
TYtomohiko yoshida
tomohiko yoshida
DMDanfu Ma
Danfu Ma
Ryou TanakaRyou Tanaka
Ryou Tanaka
Evaluation of diastolic function is a pivotal challenge due to limitations of the conventional echocardiography, especially when the heart rate is rapid as in rats. Currently, by using color M-mode echocardiography (CMME), intraventricular pressure difference (IVPD) and intraventricular pressure gradient (IVPG) in early diastole can be generated and are available as echocardiographic indices. These indices are expected to be useful for the early diagnosis of heart failure (HF), especially diastolic dysfunction. There have not been any studies demonstrating changes in IVPD and IVPG in response to changes in loading conditions in rats. Therefore, the present study aims to evaluate CMME-derived IVPD and IVPG changes in rats under various loading conditions. Twenty rats were included, divided into two groups for two different experiments, and underwent jugular vein catheterization under inhalational anesthetics. Conventional echocardiography, CMME, and 2D speckle tracking echocardiography were measured at the baseline (BL), after intravenous infusion of milrinone (MIL, n = 10), and after the infusion of hydroxyethyl starch (HES, n = 10). Left ventricular IVPD and IVPG were calculated from color M-mode images and categorized into total, basal, mid-to-apical, mid, and apical parts, and the percentage of the corresponding part was calculated. In comparison to the BL, the ejection fraction, mid-to-apical IVPG, mid IVPG, and apical IVPD were significantly increased after MIL administration (p < 0.05); meanwhile, the end-diastolic volume, E-wave velocity, total IVPD, and basal IVPD were significantly increased with the administration of HES (p < 0.05). The increase in mid-to-apical IVPD, mid IVPD, and apical IVPD indicated increased relaxation. A significant increase in basal IVPD reflected volume overloading by HES. CMME-derived IVPD and IVPG are useful tools for the evaluation of various loading conditions in rats. The approach used in this study provides a model for continuous data acquisition in chronic cardiac disease models without drug testing.

7 December 2020 in Animals
Verified
Journal Article
Open access
PDF file
Ahmed S. MandourAhmed S. Mandour
Ahmed S. Mandour
Haney SamirHaney Samir
Haney Samir
TYtomohiko yoshida
tomohiko yoshida
KMKatsuhiro Matsuura
Katsuhiro Matsuura
HAHend Abdelmageed
Hend Abdelmageed
Ryou TanakaRyou Tanaka
Ryou Tanaka
The present study aimed to provide a complete conventional echocardiographic protocol in adult male Shiba goats by using two-dimensional, M-mode, Pulsed Wave Doppler, and tissue Doppler imaging (TDI) echocardiography, and to study concomitantly xylazine-induced alteration of cardiac functions in a highly sensitive species. For this purpose, 12 male Shiba goats were included and complete conventional echocardiography from the standard right and left parasternal views was carried to report the echocardiographic data in male Shiba goats, and also before and after xylazine (Pre-Xyl and Post-Xyl) administration (0.05 mg/IM/kg). Results revealed that the full echocardiographic protocol was feasible in all goats through different cardiac windows and good Doppler alignment was achieved with non-significant variability for assessment of the left ventricular dimensions, trans-pulmonary, trans-aortic, and trans-mitral blood flow. The TDI, which was not reported previously in goats, was successfully assessed from the standard left apical view and showed distinct systolic and diastolic patterns. Xylazine administration was found to significantly reduce heart rate, fractional shortening, and cardiac output as well as the Doppler hemodynamic parameters of the pulmonary artery, aortic and mitral inflows (p < 0.05). For TDI, the Post-Xyl group revealed a significant decrease in the myocardial velocities of the septal and lateral wall of the left ventricle. The present study provides, for the first time, complete data of conventional echocardiography in male goats using the full protocol, which is routinely used in pet’s practice. Further, we illustrate in-depth the adverse effect of short-term sedative, xylazine, as used under field conditions and emphasize a simultaneous reduction in both systolic and diastolic cardiac function in goats based on full echocardiography assessment of the heart.

28 December 2021 in Animals
Verified
Journal Article
Open access
PDF file
KSKenta Sasaki
Kenta Sasaki
DMDanfu Ma
Danfu Ma
Ahmed S. MandourAhmed S. Mandour
Ahmed S. Mandour
YOYusuke Ozai
Yusuke Ozai
TYtomohiko yoshida
tomohiko yoshida
Ryou TanakaRyou Tanaka
Ryou Tanaka
Mitral valve regurgitation is a common canine heart disease. Transcatheter Edge-to-Edge Repair (TEER) is a transcatheter, edge-to-edge mitral repair device that uses a hybrid approach. No detailed information has been published on the hemodynamic effect of TEER on cardiac function. The aim of this report is to provide a longitudinal observation of the cardiac functional changes observed after TEER implantation in normal dogs using traditional, two-dimensional speckle tracking, and color M-mode echocardiographic methods. In the current report, TEER was implanted into two healthy dogs under general anesthesia. An echocardiographic examination was performed at baseline and weekly postoperative follow-ups were conducted until the fourth week. Successful TEER implantation was achieved with a short operation time (98 and 63 min) in the two dogs. Functional mitral valve regurgitation, elevated E/e’ ratio, elevated radial strain, and stable intraventricular pressure gradients (IVPG) were observed after the operation in the dogs. Mild non progressive mitral valve stenosis was observed in both dogs. TEER is a minimally invasive method for mitral valve surgery that necessitates more clinical trials. With longitudinal observation of heart function using novel approaches, better outcomes will be expected.

4 February 2021 in Ultrasound
Verified
Journal Article
Closed access
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DMDanfu Ma
Danfu Ma
Ahmed S. MandourAhmed S. Mandour
Ahmed S. Mandour
TYtomohiko yoshida
tomohiko yoshida
KMKatsuhiro Matsuura
Katsuhiro Matsuura
KSKazumi Shimada
Kazumi Shimada
Ryou TanakaRyou Tanaka
Ryou Tanaka
Intraventricular pressure gradient is regarded as a non-invasive indicator of diastolic function. Salvianolic acid B (Sal-B), a traditional Asian medicine, revealed its usefulness in myocardial infarction models; however, the hemodynamic effect of salvianolic acid B is still unknown. The present study aimed to investigate the intraventricular pressure gradient changes during the development of left ventricular hypertrophy with or without salvianolic acid B and a beta-blocker. In total, 48 rats were divided into four groups; Sham, Non-treatment, salvianolic acid B, and Carvedilol. Aortic coarctation-induced left ventricular hypertrophy was done in three groups and the treatment was started from the third to the sixth week. Blood pressure, conventional echocardiography, and color M-mode echocardiography for measurement of intraventricular pressure gradient were carried out for six consecutive weeks. At 4.5 weeks, the LV mass was elevated in the coarctation groups but the blood pressure was significantly lower in salvianolic acid B and Carvedilol groups (P < 0.05). In the Non-treatment group, the total intraventricular pressure gradient was increased at 4.5 and 6 weeks (2.60 and 2.65, respectively). Meanwhile, the basal intraventricular pressure gradient was elevated at 3 and 6 weeks (1.67 and 1.75) compared with the Sham group. Salvianolic acid B and Carvedilol significantly reduced the basal intraventricular pressure gradient at six weeks compared with the Non-treatment group (1.52 and 1.51 vs 1.75, respectively). Salvianolic acid B and Carvedilol promote cardiac function by decreasing the elevated basal intraventricular pressure gradient. The current preclinical results revealed the efficacy of salvianolic acid B as a potential therapy for left ventricular hypertrophy because of the non-blood pressure lowering effect.

18 April 2020 in Journal of Medical Ultrasonics
Verified
Journal Article
Closed access
PDF file
PKPitipat Kitpipatkun
Pitipat Kitpipatkun
KMKatsuhiro Matsuura
Katsuhiro Matsuura
KSKazumi Shimada
Kazumi Shimada
AUAkiko Uemura
Akiko Uemura
SGSeijirow Goya
Seijirow Goya
Ryou TanakaRyou Tanaka
Ryou Tanaka