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Biomedical subjects

T Yoshimura

Publications and source records attributed to T Yoshimura.

At least 793 records · Page 44Linked to original sources
PubMed1981

[Assessment of hypertrophic cardiomyopathy by ECG gated cardiac computed tomography (author's transl)].

The applicability of ECG gated cardiac computed tomography (CT) in 12 patients with hypertrophic cardiomyopathy was examined. Six of the 12 patients had hypertrophic obstructive cardiomyopathy, including one patient with mid-ventricular obstruction. Three of the 12 patients had hypertrophic non-obstructive cardiomyopathy, and three had apical hypertrophic cardiomyopathy. The diagnosis of hypertrophic cardiomyopathy was confirmed by the angiocardiogram in all patients. Cardiac CT was performed after intravenous administration of contrast media usually given as a bolus injection. The gantry was set with positive 20 degree tilt angle. In all patients with hypertrophic obstructive cardiomyopathy except for mid-ventricular obstruction, the hypertrophied interventricular septum in the basal and mid portions was observed, and the left ventricular cavity was narrowed in systole. In a patient with mid-ventricular obstruction, the marked hypertrophied interventricular septum and antero-lateral papillary muscle were observed. In diastole, the left ventricular cavity was narrow and divided into two parts. The apical cavity was completely disappeared in systole. In all patients with hypertrophic non-obstructive cardiomyopathy, the diffuse hypertrophied interventricular septum was observed in diastole. In systole, the apical portion of the left ventricular cavity was markedly narrow and anterio-lateral papillary muscle was hypertrophic. In all patients with apical hypertrophic cardiomyopathy, the marked apical hypertrophy of the left ventricular wall was observed in diastole. It is concluded that ECG gated cardiac CT could estimate myocardial wall motion and thickness and differentiate the types of hypertrophic cardiomyopathy each other.

Adult↗
PubMed1981

[Clinical usefulness of RI angiography using amplitude image and phase image by Fourier analysis for the detection of anteroseptal myocardial infarction (author's transl)].

In 19 patients with anteroseptal myocardial infarction, the wall motion of interventricular septum was analyzed by RI angiography using the amplitude image and the phase image. Both images were obtained from ECG gated blood pool data by Fourier analysis. Namely, from the first harmonic in the Fourier series, the heart motion was detected as the amplitude and phase of time-activity curve in each pixel. The distribution of the amplitudes and phases were displayed in color scale, and then both the amplitude and phase images were acquired. Those images allowed us visualization of the ischemic area, even if the scar was parallel to the detector. Moreover, we were able to assess the wall motion of the entire interventricular septum and to distinguish hypokinetic region and dyskinetic region from the hypokinetic region with shift of phase estimated by conventional method. Abnormal region detected by those images closely corresponded with the region of decreased radioisotope concentration in thallium-201 myocardial scintigram.

Adult↗
PubMed1981

[Evaluation of myocardial infarction by ECG gated cardiac computed tomography (author's transl)].

ECG gated cardiac computed tomography (cardiac (T) was performed in 9 cases with old myocardial infarction. Seven of these had anterio-septal infarction, one had inferior wall infarction and the remaining one had posterior wall infarction. All were investigated by left ventriculography and coronary arteriography. Cardiac CT was performed after intravenous administration of contrast medium usually given as a bolus injection. The infarcted myocardium was thin and showed abnormal wall motion in cardiac CT, but the motion did not always coincide with left ventricular cineangiographic findings. In 3 cases, mural thrombi at the left ventricular apex were observed by cardiac CT, and in 2 of which the thrombi were confirmed by left ventriculography. In 2 cases, cardiac CT showed stasis of contrast medium and aneurysmal formation in the left ventricular cavity and the aneurysms were confirmed by left ventriculography. Sequential 8 mm thick non-ECG gated cardiac CT scans from the cardiac apex to the base were performed in 7 cases with anterio-septal infarction, and the infarcted area were observed in the anterior interventricular septum in 6 cases. We concluded that cardiac CT was a useful noninvasive method to detect abnormal wall motion, abnormally thin wall, mural thrombus and left ventricular aneurysm in old myocardial infarction.

Adult↗
PubMed1980

Rhodamine 6G, inhibitor of both H+-ejections from mitochondria energized with ATP and with respiratory substrates.

Rhodamine 6G inhibited ATP hydrolysis by oligomycin-sensitive ATPase, purified from rat liver mitochondria, in good accord with the dose-response curve for its inhibition of energy transduction of ATP synthesis in mitochondria, but it did not inhibit ATP hydrolysis by purified F1. Rhodamine 6G also inhibited both H+-ejections from mitochondria energized with respiratory substrates and with ATP. The present findings show that the inhibitory effect of rhodamine 6G on energy transduction is not due to a modification of the transport system for adenine nucleotides, Pi, and respiratory substrates, and that the inhibition sites of rhodamine 6G are on components related with H+-ejection by redox components and also on F0.

Adenosine Triphosphate↗
PubMed1980

Relation of the structure and function of ferricytochrome c bound to the phosphoprotein phosvitin.

The relationship between the structure and function of ferricytochrome c bound to the phosphoprotein phosvitin was investigated. The rates of reduction of phosvitin-bound ferricytochrome c by cytochrome b2, ascorbate and the superoxide radical generated by xanthine oxidase wer repressed where the binding ratio was less than half the maximum, but at higher ratios they were restored gradually with increase in the ratio. The affinity of cytochrome b2 for cytochrome c was not affected by binding of cytochrome c to phosvitin. The redox potential of the bond form was lower than that of the free form and only decreased with decrease in the ratio. The conformatin around the heme moiety and the electronic structure of the heme group of bound ferricytochrome c were similar to those of free ferricytochrome c, but the conformational stability in the vicinity of the prosthetic group was related to the binding ratio as ratios above half the maximum and was well correlated with the reduction rate. Since the binding of cytochrome c to phosvitin is much stronger at binding ratios below half the maximum, these results suggest that this binding strength exclusively affects the conformational flexibility of the heme crevice in the cytochrome molecule, thus altering the reduction rate.

1-Propanol↗
PubMed1980

Stereochemical course of enoyl reduction catalyzed by fatty acid synthetase. Stereochemistry of hydrogen incorporation from reduced pyridine nucleotide.

The stereochemical course of the enoyl reduction catalyzed by fatty acid synthetase was investigated using the enzymes from rat liver and Brevibacterium ammoniagenes. Deuterium-labeled fatty acids were synthesized by incubating the synthetases with either 4R-[4-2H1]- or 4S-[4-2H1]NADPH. The deuterium-labeled fatty acids thus produced were subjected to the action of a stereospecific enzyme, acyl-CoA oxidase. The deuterium-labeled fatty acids and 2,3-dehydroacyl thioesters, the products of acyl-CoA oxidase, were methylated and analyed for deuterium content by gas chromatography-mass spectrometry. These experiments provided information to determine the configuration at the C-3 position of fatty acids formed by fatty acid synthetases. The results suggested that the stereochemistry of hydrogen (as hydride) incorporation from reduced pyridine nucleotides during enoyl reduction was different between rat liver and B. ammoniagenes synthetases: the enoyl reduction of rat liver enzyme involved the re-attack of hydride and that of B. ammoniagenes enzyme involved the si-attack of hydride.

Acyl Coenzyme A↗
PubMed1979

Interaction of cytochrome c with the phosphorprotein phosvitin.

Candida krusei cytochrome c forms a molecular complex with phosphorprotein phosvitin in weakly alkaline solution of low ionic strength. At most, about 22 molecules of cytochrome c bind to a phosvitin molecule. The complex at the binding ratio below about 11 (half of the maximum ratio) as a much higher binding strength. Several lines of evidence indicate that the marked difference in the binding strength is due to the difference in negative charges on phosvitin molecule concerned in the binding of a cytochrome c molecule. The phosvitin-bound cytochrome c seems to have a preferred orientation with the front surface of the molecule containing the exposed heme edge in contact with the phosvitin molecule.

Animals↗
PubMed1979

Evidence for dissociation of ferrihemoglobin by poly-L-lysine.

Circular dichroism and absorption spectra of ferrihemoglobin were shown to be altered upon binding with poly-L-lysine at alkaline pH. When ferrihemoglobin immobilized to Sepharose gel was treated with poly-L-lysine, hemoglobin subunits were released from the gel. These results suggest that ferrihemoglobin was dissociated into subunits by poly-L-lysine.

Circular Dichroism↗
PubMed1978

Idiopathic Parkinsonism with Lewy-type inclusions in cerebral cortex. A case report.

A case of idiopathic parkinsonism showed specific neuropathological findings, namely, the diffuse appearances of intracytoplasmic inclusions of Lewy type in the cerebral cortex in addition to many Lewy bodies in the pigmented brain stem nuclei. The staining properties and the ultrastructure of the inclusions in the cerebral cortex had a strong resemblance to those of the Lewy bodies in the substantia nigra, though a few electron microscopical differences were observed. Almost all of these 'cortical inclusions' were homogeneous or had an obscure core in their center, and they gave the impression of immature Lewy bodies.

Adult↗