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Biomedical subjects

Satoshi Saito

Publications and source records attributed to Satoshi Saito.

At least 19 recordsLinked to original sources

Multiple papillary fibroelastomas of the aortic valve: case report.

Papillary fibroelastoma is the third most common primary tumor of the heart and most commonly involve the cardiac valves. Most papillary fibroelastomas do not cause symptoms and they are usually incidental findings by routine echocardiography or at autopsy. However, multiple papillary fibroelastomas are extremely rare. We report a case with papillary fibroelastoma which was incidentally found on echocardiography. Upon surgery, a tumor was found on each aortic cusp. Pathological findings of these tumors were consistent with those of papillary fibroelastoma.

Aortic Valve↗

Identification of a novel non-coding RNA, MIAT, that confers risk of myocardial infarction.

Through a large-scale case-control association study using 52,608 haplotype-based single nucleotide polymorphism (SNP) markers, we identified a susceptible locus for myocardial infarction (MI) on chromosome 22q12.1. Following linkage disequilibrium (LD) mapping, haplotype analyses revealed that six SNPs in this locus, all of which were in complete LD, showed markedly significant association with MI (chi2=25.27, P=0.0000005; comparison of allele frequency, 3,435 affected individuals versus 3,774 controls, in the case of intron 1 5,338 C>T; rs2331291). Within this locus, we isolated a complete cDNA of a novel gene, designated myocardial infarction associated transcript (MIAT). MIAT has five exons, and in vitro translation assay showed that MIAT did not encode any translational product, indicating that this is likely to be a functional RNA. In vitro functional analyses revealed that the minor variant of one SNP in exon 5 increased transcriptional level of the novel gene. Moreover, unidentified nuclear protein(s) bound more intensely to risk allele than non-risk allele. These results indicate that the altered expression of MIAT by the SNP may play some role in the pathogenesis of MI.

Alleles↗

Generalized spasm of the right coronary artery after successful stent implantation provoked by intracoronary administration of ergonovine.

Coronary spasm may be one of the reasons for the appearance of chest pain after successful percutaneous coronary interventions, and is potentially hazardous when myocardial ischemia occurs. Coronary spasm can be diagnosed by intracoronary administration of ergonovine as a selective spasm provocative test. We report here the case of a patient who had chest pain and ST segment elevation 10 days after successful right coronary artery stent implantation. Repeat angiography was performed, with results of no in-stent stenosis and no stenosis in other segments. Since coronary artery spasm was considered as a possible reason, a spasm provocative test was attempted. Following ergonovine administration (total dose, 50 mug) into the right coronary artery, severe spasm with 99% stenosis developed over the whole artery except the stented segment. Isosorbide dinitrate was injected immediately, and the provoked spasm was soon relieved. Intravascular ultrasound revealed no neointima at the stented segment and diffuse and mild low-echogenic concentric plaque at the distal as well as proximal segment of the stent. Most reports regarding coronary artery spasm provocative tests have focused on focal lesions before interventional therapy, or during interventional procedures. Although it is quite rare, potential coronary spasm should be considered when chest symptoms recur after percutaneous coronary interventions without angiographic representation.

Coronary Angiography↗

Lipomatous hypertrophy of the interatrial septum presenting as sick sinus syndrome.

Lipomatous hypertrophy of the interatrial septum is a benign cardiac mass characterized by fat accumulation in the interatrial septum. Cardiac arrhythmias including atrial fibrillation, atrial premature contractions and atrioventricular block may occur as a consequence of involvement of the atrial wall and atrioventricular conduction pathways. We describe a patient with lipomatous hypertrophy of the interatrial septum associated with sick sinus syndrome.

Aged↗

Successful treatment of primary cardiac B-cell lymphoma: depiction at multislice computed tomography and magnetic resonance imaging.

Primary cardiac malignant lymphomas are extremely rare and the majority of lymphomas are aggressive B-cell lymphomas. We describe a patient with primary cardiac B-cell lymphoma presenting with superior vena caval syndrome and dyspnea. The tumors manifested as hypoechoic immobile masses on echocardiography, poorly enhancing masses on contrast-enhanced multislice computed tomography and iso-intense masses on T1-weighted and hyper-intense masses on T2-weighted magnetic resonance images. Pathologic examination revealed that the mass was consistent with B-cell malignant lymphoma. Systemic chemotherapy together with monoclonal CD 20 antibody treatment was initiated. There was marked regression of the tumor 4 days after the treatment and complete disappearance of the tumor after 8 days after the treatment without episodes of systemic or pulmonary embolism.

Aged↗

Multislice computed tomographic findings of the anomalous origins of the right coronary artery: evaluation of possible causes of myocardial ischemia.

BACKGROUND: Anomalous right coronary arteries (RCA) arising from the left sinus of Valsalva may cause myocardial ischemia. OBJECTIVE: We evaluated morphological features of anomalous RCA by using multislice computed tomography (MSCT) in relation to myocardial ischemia provoked by myocardial perfusion single-photon emission computed tomography. METHODS: MSCT was performed in a total of 3, 212 patients by using an Aquillion 16 and a Light Speed Ultra. Retrospective ECG-gated image reconstruction was performed. Volume rendering, axial and curved multiplanar reformatted images were analyzed for the determination of the origin and course of the RCA, the take-off angle of the RCA from the aorta, and size of the RCA orifice. Furthermore, virtual angioscopic images were also used for the evaluation of the RCA orifice structure. RESULTS: Anomalous origins of the RCA were found in 15 patients. In 13 patients, the RCA arose from the left sinus of Valsalva, and in 2 patients it arose from the left main coronary artery as a single coronary artery. The RCA coursed anteriorly between the ascending aorta and pulmonary artery in 14 patients, whereas it had a retroaortic course in 1 patient. Acute angle take-off (<30 degrees ) of the RCA from the aorta and the left main coronary artery was observed in 8 patients, intramural course of the RCA within the aortic wall was observed in 6 patients and a small RCA orifice was observed in 4 patients. Exercise-induced myocardial ischemia was present in 5 patients. CONCLUSION: Coursing between the aorta and pulmonary artery, acute angle take-off and intramural course were thought to be major causes of exercise-induced ischemia in patients with anomalous origins of the RCA.

Aged↗

Effects of G-CSF on cardiac remodeling and arterial hyperplasia in rats.

Although granulocyte colony-stimulating factor (G-CSF) has been shown to prevent cardiac remodeling after acute myocardial infarction, the mechanism and safety of G-CSF treatment acute myocardial infarction remain controversial. The purpose of the present study was to investigate in a rat model the mechanisms underlying the beneficial effect of G-CSF in acute myocardial infarction and to determine whether G-CSF treatment aggravates vascular remodeling of injured artery after acute myocardial infarction. Sprague-Dawley rats received transplanted bone marrow cells from green fluorescent protein (GFP) transgenic rats. Acute myocardial infarction was induced by ligation of the left coronary artery. After 24 h, the right carotid artery was injured with a balloon catheter. G-CSF (100 microg/kg/day) or saline was injected subcutaneously for 5 consecutive days after induction of acute myocardial infarction. G-CSF treatment significantly improved left ventricle function and reduced infarct size in rats with acute myocardial infarction. Expression of mRNA for the angiogenic cytokines was significantly higher in the infarction border area in the G-CSF group than in the control group. The surviving cardiomyocytes in infarction area were more in the G-CSF group. GFP-positive cells were gathered in the infarction border area in both groups; G-CSF did not increase cardiac homing of GFP-positive bone marrow cells in contrast to control group. Most GFP-positive cells were CD68-positive (macrophages). It was difficult to find bone marrow-derived cardiomyocytes in the infarcted area. G-CSF treatment inhibited neointima formation and increased reendothelialization of the injured artery. GFP-positive cells were identified most in the adventitia of the injured artery. A few cells in the neointima and reendothelialization were GFP positive. In conclusion, administration of G-CSF appears to be effective for treatment of left ventricular remodeling after acute myocardial infarction and does not aggravate vascular remodeling. The effect of G-CSF on cardiac and vascular remodeling may occur mainly through a direct action on the heart and arteries.

Actins↗

Coronary artery dissection after blunt chest trauma: depiction at multidetector-row computed tomography.

Coronary artery dissection after blunt chest trauma has rarely been reported in traumatic cardiac injuries, but it may cause fatal or nonfatal myocardial infarction. We report a case of dissection of the left main coronary artery, which resulted in acute myocardial infarction 5 weeks after blunt chest trauma. Multidetector-row computed tomography performed prior to the onset of infarction depicted intimal flap and dissected cavities.

Accidents, Traffic↗

Coronary artery abnormalities after Kawasaki disease in an adult: depiction at whole heart coronary magnetic resonance angiography.

Whole heart coronary magnetic resonance angiography (MRA) was performed in a 57-year-old man with a provisional diagnosis coronary artery aneurysm due to Kawasaki disease. MRA revealed aneurysms in the left anterior descending artery and the left circumflex artery. It also revealed stenosis in the left anterior descending artery and occlusion in the right coronary artery with a collateral vessel connecting between the proximal and distal sites of the occlusion.

Coronary Aneurysm↗

Isolated subvalvular pulmonary stenosis: depiction at whole heart magnetic resonance imaging.

Isolated subvalvular pulmonary stenosis is a rare condition and its morphological evaluation is obscure. Whole heart magnetic resonance imaging (MRI) is a new, totally non-invasive technique which allows three-dimensional comprehension of the cardiac structure. We describe a patient with isolated subvalvular pulmonary stenosis, in whom whole heart MRI was useful to detect and evaluate the right ventricular outflow obstruction.

Humans↗

MDCT detection of double right coronary artery arising from a single ostium in the right sinus of Valsalva: report of 2 cases.

Double right coronary artery arising from a single ostium in the right sinus of Valsalva is an extremely rare coronary artery variation. Differentiating this variation from high take off of a large right ventricular branch is often difficult in conventional coronary angiography. In two cases, multidetector-row computed tomography (MDCT) identified double right coronary artery. MDCT allows three-dimensional comprehension of the coronary artery anatomy and it is thought to be useful to distinguish this variation from a large right ventricular branch.

Abnormalities, Multiple↗

Whole heart coronary magnetic resonance angiography for the detection of coronary artery stenosis and atherosclerotic coronary artery plaque in a patient with unstable angina.

Whole heart coronary magnetic resonance angiography (MRA) has been established as a totally noninvasive diagnostic modality for the assessment of coronary artery disease. We report a case with unstable angina, in whom coronary artery stenosis with an atherosclerotic plaque was detected by whole heart coronary MRA. Intravascular ultrasound in the stenotic lesion revealed a soft plaque containing focal calcification, corresponding to a low-signal mass containing a no-signal mass on MRA. Whole heart coronary MRA can become a useful diagnostic tool for the diagnosis of acute coronary syndrome.

Aged↗

Tumor-derived TGFbeta-1 induces dendritic cell apoptosis in the sentinel lymph node.

Lymphatic flux from a primary tumor initially flows into a tumor-draining lymph node (LN), the so-called sentinel LN (SLN). Carried by the lymph fluid are a variety of mediators produced by the tumor that can influence immune responses within the SLN, making it a good model with which to investigate tumor-related immunology. For instance, dendritic cell (DC) numbers are reduced in SLNs from melanoma and breast cancer patients. In the present study, we investigated the mechanism by which DC numbers were reduced within SLNs from patients with non-small cell lung cancer. We found that the incidence of apoptosis among DCs was higher in SLNs than in non-SLNs, as were levels of TGFbeta-1. In contrast, levels of TGFbeta-1 mRNA did not differ between SLNs and non-SLNs, but were 30 times higher in tumors than in either LN type. In vitro, incubation for 2 days with TGFbeta-1 induced apoptosis among both cultured DCs and DCs acutely isolated from normal thoracic LNs, effects that were blocked by the TGFbeta-1 inhibitor DAN/Fc chimera. Taken together, these results suggest that tumor-derived TGFbeta-1 induces immunosuppression within SLNs before the movement of tumor cells into the SLNs, thereby facilitating metastasis within those nodes.

Apoptosis↗

Left ventricular aneurysm associated with isolated noncompaction of the ventricular myocardium.

A 66-year-old woman was admitted to our hospital because of left ventricular failure and nonsustained ventricular tachycardia. Two-dimensional echocardiography demonstrated prominent trabeculations and deep intertrabecular recesses, findings consistent with noncompaction of the ventricular myocardium. Myocardial perfusion scintigraphy demonstrated a defect in the anterobasal left ventricular segment. Coronary angiogram was normal, but the left ventriculogram showed an aneurysm in the anterior myocardial segments. This is the first reported case with isolated noncompaction of the ventricular myocardium associated with left ventricular aneurysm.

Aged↗