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Biomedical subjects

Y Fukuhara

Publications and source records attributed to Y Fukuhara.

At least 91 records · Page 5Linked to original sources

[Clinical estimation of the relation between coronary artery disease and regional myocardial blood flow by continuous thermodilution with the multithermistor catheter].

To evaluate coronary hemodynamics more precisely in ischemic heart disease, great cardiac vein flow ( GCVF ) and coronary sinus flow (CSF) were simultaneously measured before and during atrial pacing by a continuous thermodilution technique with the multithermistor catheter in 10 patients with significant coronary stenosis (narrowing of the left anterior descending artery of 75% or more) (Group 1: CAD) and 12 cases with the normal coronary artery (narrowing of 25% or less) (Group 2: NonCAD ). GCVF reflects the anterior regional flow of the left ventricle and CSF reflects total left ventricular flow. Between the two groups, no significant differences were noticed in either resting GCVF or resting CSF. However, atrial pacing induced a reduction of coronary resistance (CR) and increasing regional myocardial blood flow in both groups in the same way, and the maximal pacing provoked anginal episode in CAD group in which both the percent decrease of coronary resistance (CR) (% delta CRant 25.3% and % delta CRt 23.3%) and the percent increase of regional myocardial blood flow (% delta GCVF 49.6% and % delta CSF 40.6%) were lower than those in NonCAD group (% delta CRant 42.3%, % delta CRt 37.6%, % delta GCVF 80.6%, and % delta CSF 68.3%, respectively). These data imply that resting coronary blood flow may be maintained as normal in patients with angiographically significant coronary stenosis, though coronary reserve probably decreased in these patients. In this respect, the continuous thermodilution technique using the multithermistor catheter may be useful for the clinical estimation of coronary hemodynamics induced by various interventions. This technique can be performed repeatedly for a short time and permits simultaneous assessment of venous blood flow draining from the anterior wall and of total left ventricular flow.

Cardiac Pacing, Artificial↗

Effect of arginine or creatinine administration on the urinary excretion of methylguanidine.

The metabolic pathway of methylguanidine (MG) is mainly speculated from the change in urinary excretion of MG in the arginine (Arg)-injected normal rat, the creatinine (Cr)-injected normal rat, and the Arg-injected uremic rat. 15N-Arg was ingested to 2 uremic patients. Arg administration resulted in marked increase in urinary MG excretion both in the uremic rat and patient, but not in the normal rat. In the first phase of the 15N-Arg ingestion experiment, a rapid rise of 15N atom percent excess of urinary MG was observed in the uremic patient. In the second phase of this study, after 24 h of 15N-Arg ingestion, the 15N atom percent excess of urinary Cr and that of MG closely paralleled. These findings imply that there might be two metabolic origins of MG: one is a formation of MG from Arg itself or an Arg metabolite other than Cr, the other a pathway producing MG via Cr. The former is compatible with the hypothesis by Cohen.

Animals↗

Relation between chemical constituents of tobacco and mutagenic activity of cigarette smoke condensate.

Mutagenic activities of cigarette smoke condensate were assayed in the presence of S-9 Mix using Salmonella typhimurium TA 98. The results were examined in relation to chemical data of tobacco leaves. Among the nitrogenous constituents examined, the contents of total nitrogen and protein nitrogen and the soluble nitrogenous fraction were positively and significantly related to an increase in mutagenic activity of the smoke condensate, whereas nicotine and nitrate were not important in contributing to mutagenic potency of such condensates. The age of tobacco leaves influenced the mutagenic potency of the condensate, which was lowest in leaves from the lower stalk position and increased with ascending leaf position on the stalk. Smoke condensate from tobacco with higher sugar content resulted in lower mutagenic activity. The present results, together with the previous study on the mutagenicity of the amino acid pyrolyzates, suggest that potent mutagens in cigarette smoke condensate are nitrogen-containing compounds, which may be formed from proteins and amino acids during the burning of a cigarette.

Amino Acids↗

Prognosis of chronic glomerulonephritis in adult patients estimated on the basis of the Markov process.

The prognosis of chronic glomerulonephritis based on renal function was assessed using a statistical technique of the Markov process, where the absorbing state was assumed to be an uremic state, 194 adult patients with different types of disease were subjected to study. The 15 min value obtained in the intravenous PSP excretion test was divided into five states; SI (greater than 34%, normal), SII(25-34), SIII(15-24), SIV(5-14) and SV (greater than 5, uremic). The rates of SV with time were calculated with respect to several clinical characteristics. The prognosis of the patients with hypertension, distinct proteinuria and hematuria, or cellular cylindruria appeared to be relatively poor. The estimated number of years from each state to SV were also calculated. The results were similar to those already reported and gave us more exact information about the prognosis.

Adult↗