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Biomedical subjects

Takeshi Kimura

Publications and source records attributed to Takeshi Kimura.

At least 19 recordsLinked to original sources

Unexpected sudden death resulting from anomalous origin of the right coronary artery from the left sinus of Valsalva: a case report involving identical twins.

An anomalous origin of the coronary arteries had been implicated as a cause of sudden cardiac death in a case involving a 16-year-old student who suddenly collapsed while running track at school. An autopsy revealed that the right coronary artery arose from the aorta in the left sinus of Valsalva. In order to determine whether the same anomaly was inherent in his brother--an identical twin--a complete cardiac medical examination was conducted. Multi-detector-row computed tomography (MDCT) coronary angiography showed no anomaly at the sinus of Valsalva, which indicates that the anomaly, in this case, was not hereditary. This case exemplifies instances where forensic medicine may intervene to prevent sudden deaths in surviving family members.

Adolescent↗

Measurements of baseline and follow-up concentrations of cardiac troponin-T and brain natriuretic peptide in patients with heart failure from various etiologies.

Since chronic heart failure (CHF) is a complex clinical syndrome, a single biomarker may not reflect all of its characteristics. In this study, the clinical significance of combination and serial measurement of biochemical markers of myocyte injury and myocardial load in patients with CHF from various etiologies was examined. Serum concentrations of cardiac troponin-T (cTnT) and plasma concentrations of brain natriuretic peptide (BNP) were measured simultaneously in 190 patients with CHF, including dilated cardiomyopathy (DCM) (n = 41), ischemic heart disease (n = 40), valvular or congenital disease (n = 53), hypertensive heart disease (n = 16), and hypertrophic cardiomyopathy (HCM) (n = 22). Serum cTnT concentrations >or=0.01 ng/ml were found in 46/190 patients (24%) at baseline (20% in DCM, 42% in ischemic heart disease, 21% in valvular or congenital disease, 43% in hypertensive heart disease, and 9% in HCM). Follow-up samples were obtained in 137 patients after a mean treatment period of 31.8 days. Although BNP decreased significantly in each disease category (P < 0.0001: DCM; P < 0.005: ischemic heart disease; P < 0.05: valvular or congenital disease; P < 0.005: hypertensive heart disease; P < 0.05: HCM), cTnT remained high in 36/137 patients (26%) (19% in DCM, 39% in ischemic heart disease, 25% in valvular or congenital disease, 38% in hypertensive heart disease, and 19% in HCM). The rate of adverse cardiac events was significantly higher in patients with high cTnT than in patients with low cTnT concentrations (P < 0.0001) (P < 0.05: DCM; P < 0.05: ischemic heart disease; P < 0.01: valvular or congenital disease). Multivariate analysis showed that both cTnT and BNP are independent prognostic factors, and patients with elevations of both cTnT and BNP had the poorest prognosis (P < 0.0001). In patients with CHF, the evolution and prognostic value of cTnT and BNP are different. The combined measurements of these markers should refine our understanding of the state and evolution of CHF.

Aged↗

Structural and functional assessment of arrhythmogenic right ventricular dysplasia/cardiomyopathy by multi-slice computed tomography: comparison with cardiovascular magnetic resonance.

Arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C) is an uncommon inheritable cardiomyopathy involving predominant right ventricle with progressive fibrofatty tissue replacement. An integrated assessment of electrical, functional and anatomic abnormalities, in addition to personal and family history would be used to diagnose this disease entity. We present the case of a 69-year-old man with a history of sustained ventricular tachycardia. Fatty infiltration and regional wall motion abnormalities over biventricular myocardium were clearly demonstrated by cardiac 64-slice computed tomography (CT), as consistent with magnetic resonance imaging. Thus, multi-slice CT may have a significant role in the assessment and follow-up of patients with ARVD/C by providing excellent structural, functional assessment and tissue characterization.

Aged↗

Identification of lipomatous metaplasia in old infarcted myocardium by cardiovascular magnetic resonance and computed tomography.

Lipomatous metaplasia of myocardium after myocardial infarction (MI) is less reported, and the exact prevalence and clinical implications of this phenomenon are unclear. A case of lipomatous metaplasia after MI evaluated with cardiovascular magnetic resonance (CMR) and computed tomography (CT) is presented. The presence of lipomatous metaplasia could not be easily differentiated from scar simply by the delayed-enhanced images. Loss of signal on TrueFISP cine MRI can be a hint. A pre-contrast T1-weighted image with or without frequency-selective fat suppression is useful in order to verify the existence of lipomatous metaplasia on CMR.

Humans↗

Complementary appearance of glucose and lipid metabolism in cardiac sarcoidosis.

Sarcoidosis is a non-caseating granulomatous systemic disease of unknown pathogenesis, and cardiac involvement is the most important prognostic factor. We have evaluated the value of the combined study of F-18 fluoro-2-deoxyglucose positron emission tomography and iodine-123 labeled 15-(p-iodophenyl)-3R,S-methylpentadecanoic acid single-photon emission tomography for the assessment of cardiac involvement of sarcoidosis, by comparing the findings with gadolinium magnetic resonance in a patient with histologically-proven cardiac sarcoidosis.

Aged↗

Endovascular repair of a thoracoabdominal aortic aneurysm involving the celiac artery and the superior mesenteric artery.

We present a successful endovascular repair of a thoracoabdominal aortic aneurysm (TAAA) involving the celiac artery and the superior mesenteric artery. After the intentional occlusion of the celiac artery, an Inoue stent graft with a side arm to the superior mesenteric artery was implanted. Management of the visceral arteries in the endovascular repair of TAAA was highlighted.

Aged↗

Plasma amino acid profiles applied for diagnosis of advanced liver fibrosis in patients with chronic hepatitis C infection.

UNLABELLED: Although biopsy has been considered mandatory in diagnosing liver fibrosis, there is a high demand for alternative effective and noninvasive methods. In this study we aimed to develop a noninvasive and effective method using the plasma amino acid profiles for the diagnosis of liver fibrosis. MATERIALS AND METHODS: Fifty-three patients with chronic hepatitis C infection were included in the study. Plasma amino acid concentration was analyzed and severity of fibrosis was staged based on biopsy. We employed a previously published amino acid-based approach to develop a discriminator (designated as an "amino-index") for the diagnosis of patients with advanced liver fibrosis. The area under the receiver operating characteristic curve (AUC) was used for evaluation of the diagnosis. RESULTS: (Phe)/(Val)+(Thr+Met+Orn)/(Pro+Gly) was derived as the optimal amino index. The AUCs were 0.92+/-0.04 (SE) and 0.99+/-0.01 for discriminating advanced fibrosis (fibrosis stages F3 and F4) and for discriminating cirrhosis, respectively. By use of the optimal cut-off values, both the sensitivity and specificity achieved a score over 0.88. CONCLUSION: Fibrosis index based on amino acid concentration could be applied to diagnose liver fibrosis as a convenient noninvasive approach.

Journal Article↗

Cardiac functional analysis by free-breath real-time cine CMR with a spatiotemporal filtering method, TSENSE: comparison with breath-hold cine CMR.

The aim of this study was to assess the accuracy of cardiac functional values obtained from free-breathing real-time cine CMR with the temporal sensitivity encoding (TSENSE) technique by comparing them with values obtained from conventional cine CMR. For the real-time cine CMR, two protocols were employed, one with good temporal resolution and one with good spatial resolution. The functional values obtained from the high temporal resolution real-time cine CMR agreed and correlated well with those of cine CMR. On the other hand, statistically significant but clinically slight overestimation of ESV (p < .05) and underestimation of EF (p < .01) were observed with the other protocol. Real-time cine CMR with TSENSE can provide acceptable cardiac functional values.

Aged↗

Network analysis of plasma and tissue amino acids and the generation of an amino index for potential diagnostic use.

BACKGROUND: Few studies exist on the use of metabolic profiling of amino acids to examine underlying physiologic and disease states. OBJECTIVE: We aimed to introduce a new method for studying relations among amino acids and to generate a diagnostic index, or amino index, based on amino acid concentrations. DESIGN: For network analysis, 35 Fischer-344 rats were randomly divided into 7 groups and fed diets containing 5%, 10%, 15%, 20%, 30%, 50%, or 70% protein. Amino acid concentrations in plasma and various organs were used to derive correlation coefficients that were then used to construct correlation networks. To build a diagnostic index for diabetic rats, the plasma amino acid concentrations of diabetic and normal rats were analyzed by using a novel algorithm developed to generate amino acid-based indexes. Plasma amino acid concentrations from human growth hormone transgenic rats and insulin-treated diabetic rats were used to evaluate the index obtained for diabetes. Dimethylnitrosamine-treated Sprague-Dawley rats were used to generate an index for hepatic fibrosis. RESULTS: The scatter plots of plasma amino acid concentrations showed distinct patterns in different organs that were due to the different protein contents of the diets. Network analysis showed that data-driven networks for blood and tissue could be obtained. We derived a diagnostic index for the discrimination of diabetic rats with both sensitivity and specificity >97% and another surrogate index for liver hydroxyproline with a correlation of r2= 0.85. CONCLUSIONS: Correlation-based network analysis may help to uncover specific physiologic conditions or states. A novel approach using amino acid molar ratios was shown to generate indexes that can be used to separate animal disease models and monitor the progression of a disease parameter. Some of the methods described here may be applicable to the clinical setting.

Algorithms↗

Screening of toxicity biomarkers for methionine excess in rats.

Although many animal studies have reported that dietary excess of methionine causes toxic changes including growth suppression and hemolytic anemia, the biochemical mechanism and biomarkers for methionine toxicity have not been well elucidated. The present study aimed to identify toxicity biomarkers from plasma metabolites in rats fed excessive methionine. Young growing rats were fed graded doses of additional methionine for 2 wk. Cluster analysis of multivariate correlations was performed on the physiological and toxicity variables with plasma metabolites detected by GC/MS, amino acid analyzer, and thiol-specific analysis. Indicative variables for hemolysis such as splenic nonheme iron content and plasma bilirubin were grouped in the same cluster as many methionine metabolites. Homocysteine and some undefined metabolites in this cluster were found to be strong discriminators between nontoxic and toxic levels of methionine intake. Product-to-precursor ratios of each methionine metabolite demonstrated that excessive methionine intake caused a marked decrease only in the ratio of cystathionine to homocysteine, suggesting that metabolism from homocysteine to cystathionine would be rate limiting in the disposal of excessive methionine. Collectively from these results, homocysteine appeared to be the most plausible biomarker to assess methionine excess as a surrogate marker both for toxicity and for setting a metabolic upper limit.

Amino Acids↗

Japan assessment of pitavastatin and atorvastatin in acute coronary syndrome (JAPAN-ACS): rationale and design.

BACKGROUND: Many trials have shown that 3-hydroxy-3-methyl-glutaryl coenzyme A (HMG-CoA) reductase inhibitors reduce the incidence of cardiovascular events and mortality. One method of decreasing the incidence of cardiovascular events could be to reduce the progression of coronary atherosclerosis, and a recent study found that atorvastatin can cause coronary plaque to regress. To generalize this finding, using conventional HMG-CoA reductase inhibitors at many Japanese centers, randomized trials of pitavastatin and atorvastatin will be conducted with patients with acute coronary syndrome (ACS). METHODS AND RESULTS: Patients with ACS who have undergone successful percutaneous coronary intervention under intravascular ultrasound guidance will be studied. They will be randomly allocated to pitavastatin or atorvastatin groups and followed up for 8-12 months. The primary endpoint will be the percent change in coronary plaque volume, and secondary endpoints will include absolute changes in coronary plaque volume, serum lipid levels and inflammatory markers. The safety profile will also be evaluated. CONCLUSIONS: This study will examine the ability of HMG-CoA reductase inhibitors to regress coronary plaque in Japanese patients with ACS and the findings should help to improve the prognosis of such patients and clarify the involved mechanisms.

Atorvastatin↗

Acute pleuropericarditis after coronary stenting: a case report.

A case of acute pleuropericarditis, which occurred after apparently successful percutaneous coronary intervention (PCI) for chronic total occlusion of the right coronary artery, is reported. The patient underwent coronary stenting without any immediate signs of complications. However, he had an acute onset of chest pain with fever which happened 4 h after PCI. He was diagnosed with acute pleuropericarditis by blood tests, electrocardiogram, chest X-ray, and echocardiogram. He rapidly recovered by intravenous hydrocortisone followed by oral prednisone administrations and percutaneous catheter pericardial drainage. Acute pleuropericarditis relevant to post-cardiac injury syndrome with an atypically early onset might have occurred in this case as a rare complication of PCI.

Acute Disease↗

Thoracoabdominal-aortoiliac MDCT angiography using reduced dose of contrast material.

OBJECTIVE: The objective of our study was to compare the image quality of MDCT angiography studies obtained by injection of low doses of contrast medium with saline flush versus conventional doses of contrast medium. MATERIALS AND METHODS: Seventy-one patients with pre- or postoperative aortic aneurysms underwent MDCT angiography throughout the thoracoabdominal-aortoiliac system using an 8-MDCT scanner. In 37 patients, 100 mL of contrast medium was injected at a flow rate of 3.0 mL/s (hereafter referred to as the 100-mL group). In 34 patients, 50 mL of contrast medium followed by a 20-mL saline flush was injected at a flow rate of 2.5 mL/s (the 50-mL group). For each group, quantitative analysis involved calculating the mean aortoiliac enhancement, plateau deviation, and contrast enhancement in the pulmonary trunk and superior vena cava (SVC). Qualitative analysis involved assessing the 3D postprocessing images. RESULTS: Significant differences between the groups in mean aortoiliac enhancement (100-mL group vs 50-mL group, 337 +/- 6 H vs 319 +/- 5 H, p < 0.0001) and mean plateau deviation (51 +/- 4 H vs 58 +/- 4 H, p < 0.0001) were found. However, adequate arterial enhancement (>or= 200 H) was observed in 31 of 34 patients in the 50-mL group and uniform aortoiliac enhancement (< 50 H) was seen in 26 patients. Visual analysis showed no difference in contrast material magnitude and homogeneity between the groups. Furthermore, in the 50-mL group, the thoracic aorta was more clearly visualized because of a reduction in the opacity of the main pulmonary artery and SVC. CONCLUSION: In our experience, administration of 50 mL of contrast medium followed by a 20-mL saline flush produces thoracoabdominal-aortoiliac MDCT angiographic examinations of effective quality in most cases.

Adult↗

Serum soluble lectin-like oxidized low-density lipoprotein receptor-1 levels are elevated in acute coronary syndrome: a novel marker for early diagnosis.

BACKGROUND: Markers of cardiac injury, including troponin-T (TnT), are used to diagnose acute coronary syndrome (ACS); however, markers for plaque instability may be more useful for diagnosing ACS at the earliest stage. Lectin-like oxidized LDL receptor-1 (LOX-1) appears to play crucial roles in the pathogenesis of atherosclerotic plaque rupture and ACS onset. LOX-1 is released in part as soluble LOX-1 (sLOX-1) by proteolytic cleavage. METHODS AND RESULTS: We examined serum sLOX-1 levels in 521 patients, consisting of 427 consecutive patients undergoing coronary angiography, including 80 ACS patients, 173 symptomatic coronary heart disease patients, 122 patients with significant coronary stenosis without ischemia, and 52 patients without apparent coronary atherosclerosis plus 34 patients with noncardiac acute illness and 60 patients with noncardiac chronic illness. Time-dependent changes in sLOX-1 and TnT levels were analyzed in an additional 40 ACS patients. Serum sLOX-1 levels were significantly higher in ACS than the other groups and were associated with ACS as shown by multivariable logistic regression analyses. Given a cutoff value of 1.0 ng/mL, sLOX-1 can discriminate ACS from other groups with 81% and 75% of sensitivity and specificity, respectively. sLOX-1 can also discriminate ACS without ST elevation or abnormal Q waves and ACS without TnT elevation from non-ACS with 91% and 83% of sensitivity, respectively. Peak values of sLOX-1 in ACS were observed earlier than those of TnT. CONCLUSIONS: sLOX-1 appears to be a useful marker for early diagnosis of ACS.

Acute Disease↗