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Biomedical subjects

H Matsuo

Publications and source records attributed to H Matsuo.

At least 19 recordsLinked to original sources
PubMed1979

A new modulation method with range resolution for ultrasonic Doppler flow sensing.

This paper proposes a new pair of sequences whose cross-correlation values are zero except for the peak value and presents a new modulation method for an ultrasonic Doppler flowmeter with high sensitivity utilizing these sequences. In this method, transmitted and received waves are modulated and demodulated, respectively, by the specified new sequences. Since ulfavourable reflected waves can be almost completely eliminated by this proposed modulation method, a high signal-to-noise ratio is easily achieved. Elementary experimental results are also given.

Doppler Effect↗
PubMed1979

Hydrogen-tritium exchange titration of the histidine residues in bovine heart cytochrome c and analysis of their microenvironment.

Microenvironments of the three histidine residues located at the positions 18, 26, and 33 from the amino terminus in bovine heart cytochrome c were analysed in solution by the hydrogen-tritium exchange titration method, which has been developed in this laboratory. Histidine-18, which is liganded to the heme iron, and histidine-26 did not incorporate tritium in native state, indicating that the two are located in solvent inaccessible hydrophobic regions. Histidine-33 was labeled with tritium to an appreciable extent and seemed to be partially buried in the molecule. The pKa value estimated for histidine-33 was 6.1 at 37 degrees by the tritium exchange titration, suggesting that the residue interacts very weakly with a neighboring cationic group. These results seem to be compatible with the tertiary structure of the protein deduced from the X-ray crystallographic analysis.

Amino Acid Sequence↗
PubMed1979

Rotational excursion of heart in massive pericardial effusion studied by phased-array echocardiography.

We have observed rotational excursion, comprising anteroposterior and right to left movement of the heart, and cardiac twist around the long axis in 2 patients with massive pericardial effusion, using a phased-array echocardiograph recently developed in this country. Sagittal real-time cross-sections showed only the anteroposterior swing motion, but horizontal cross-sections revealed a counterclockwise rotational excursion and cardiac twist during this rotational excursion. The rotational excursion consisted of a rapid and almost straight movement right and posteriorly in systole, and a slow arcing excursion left and anteriorly in diastole. The speed of this movement was not uniform. The heart disclosed dominant counterclockwise twisting motions in mid to late systole and in late diastole, synchronous with atrial contraction. These movements were described relative to an external system of co-ordinates. Controls, consisting of a normal healthy subject, and cases with mitral stenosis, mitral regurgitation, and hypertrophic cardiomyopathy, did not show any rotational excursion. In the latter 2 diseases, cardiac twists were observed, but they were less dominant than in cases with massive pericardial effusion.

Aged↗
PubMed1979

Electrophysiologic study and prognosis of chronic bifascicular block.

Thirty patients (22 males and 8 females, aged 64 to 89 years) with chronic bifascicular block were studied electrophysiologically and prognosis was assessed. Three had RBBB with LPH, 17 had RBBB with LAH, and 10 had LBBB. AH interval was prolonged in 12 (43%) of 28 patients and HV interval was prolonged in 11 (37%) of 30 patients. Of 16 patients with first or second degree AV block, 11 (69%) had prolonged AH interval and 8 (50%) had prolonged HV interval. Effective refractory period of the right atrium was prolonged in 8 (50%) of 16 patients and that of atrioventricular node was prolonged in 9 (64%) of 14 patients. Second degree AV block was observed at lower rates of atrial pacing (130 beats/min or less) in 14 (74%) of 19 patients. Sinus node dysfunction was present in 16 (62%) of 26 patients. During the follow-up period (37.1 +/- 6.1 months), advanced or complete AV block developed in 2 of 27 patients (2.4% per year) and a patient died of acute myocardial infarction (1.1% per year). The present study showed that prolongation of AH interval was observed more frequently than that of HV interval, and the presence of widespread lesions in the conduction system was suggested in chronic bifascicular block, and in spite of these facts prognosis was not so unfavorable as reported previously.

Aged↗
PubMed1979

Apparent suppression of ventricular parasystole by cardiac pacing.

Complete disappearance of ventricular parasystolic beats by cardiac pacing with the rates of near multiples of the parasystolic rate was observed in 2 patients with ventricular parasystole. This finding represents a clinical counterpart of recently demonstrated experimental and mathematical models of electrotonic modulation of the parasystolic discharge.

Adolescent↗
PubMed1979

Mitogenic effect of a novel animal lectin on human lymphocytes.

The mitogenic effect of the novel lectin prepared from an animal source on human lymphocytes was examined in comparison with that of phytohemagglutinin-p (PHA-p) by the uptake of 3H-thymidine. The uptake of 3H-thymidine by lymphoblasts was enhanced by the treatment with the lectin as well as with PHA-p, though the effect of the lectin was difficult to compare exactly with that of PHA-p.

Dose-Response Relationship, Drug↗