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Biomedical subjects

M Yasuno

Publications and source records attributed to M Yasuno.

At least 19 recordsLinked to original sources
PubMed1992

Takayasu's arteritis with collateral circulation from the right coronary artery to intracranial vessels--a case report.

A forty-four-year-old woman with Takayasu's arteritis and involvement of the aortic arch and its main branches complained of precordial pain on effort. Exercise electrocardiograms revealed significant ST segment depression in leads II, III, aVF, and V. Coronary arteriograms demonstrated no stenosis. However, the right coronary arteriogram revealed collateral circulation arising from the sinus node artery to the bilateral vertebral arteries and the left internal carotid artery. The collateral circulation was considered to be an important route of blood flow supply to the brain and, at the same time, a cause of coronary steal syndrome and, consequently, of angina pectoris.

Adult↗
PubMed1991

[A case of aortitis syndrome with coronary steal syndrome due to collateral circulation from the right coronary artery to intracranial vessels].

A 44-year old female with aortitis syndrome complained of precordial pain on effort. Exercise electrocardiograms revealed significant ST segment depression in leads II, III, aVF and V. Coronary arteriograms demonstrated no stenosis. However, the right coronary arteriogram revealed collateral circulation arising from the sinus node artery to the bilateral vertebral arteries and the left internal carotid artery. Collateral vessels in aortitis.syndrome arising from the coronary artery to the lung have been reported sporadically. However, to our knowledge, the collateral circulation from the coronary artery to intracranial vessels as seen in the present case has never been reported. In the present case, the left ventricular hypertrophy was observed on electrocardiograms and echocardiograms. It can not be denied that it was a cause of the angina pectoris. However, exercise myocardial scintigraphy showed transient myocardial ischemia at stress on the inferoposterior wall corresponding to leads II, III, aVF and V on electrocardiograms. Therefore, coronary steal syndrome due to the collateral pathway from the coronary artery may be considered a likely cause of the angina pectoris. The collateral circulation was considered to be an important route of blood flow supply to the brain and, at the same time, a cause of coronary steal syndrome and consequently angina pectoris.

Adult↗
PubMed1990

[A case of primary coronary artery dissection].

Primary coronary artery dissection occurring as a spontaneous event and not associated with trauma due to catheter manipulation is rare. We recently experienced (a case of) a 52-year-old man with primary artery dissection. He was admitted to our hospital with severe chest pain as his chief complaint on September 6, 1988. Electrocardiography and laboratory data showed acute inferior myocardial infarction. He was treated with medication and underwent coronary angiograms on October 3, 1988. Right coronary angiogram revealed an intimal flap and false lumen. But right coronary angiograms 6 months after the onset of myocardial infarction revealed progression of stenosis but no intimal flap, and coronary spasm was not evoked after acetylcholine administration. Primary coronary artery dissection has been reported since Pretty's first description of it in 1931. The majority of earlier cases were diagnosed at autopsy, but recently reports of survivors have been increasing due to the progress in and popularization of coronary angiographic technics. This case is the 46th case of primary coronary dissection found by coronary angiography. So it is not extremely rare. In our case the involved artery was the right coronary artery. In survivors, right coronary artery dissection is more frequent than left, because the area supplied by the right coronary artery is smaller than the area supplied by the left one. Although in our case coronary artery stenosis progressed, after a long term resolution of dissection may occur. There are a few cases in which resolution of dissection occurred naturally.(ABSTRACT TRUNCATED AT 250 WORDS)

Aortic Dissection↗
PubMed1987

Chronic effects of Cd on the reproduction of the guppy (Poecilia reticulata) through Cd-accumulated midge larvae (Chironomus yoshimatsui).

Chronic effects of Cd on the growth and reproduction of the guppy (Poecilia reticulata) were studied using a food chain model, midge larvae as prey and guppy as predator. The transfer rate of Cd from the midge to the guppy was between 0.5 and 1% during the 30-day experiment. Growth rate of the guppy fed Cd-accumulated midge larvae (270 micrograms/g dry wt) for 30 days was not impaired. Cumulative numbers of fry produced by the guppy fed Cd-accumulated midge larvae (210 micrograms/g) for 2 months decreased to ca. 80% of the control. Guppies had been fed the Cd-accumulated midges from 30 days old for 7 months. Cumulative numbers of fry produced by the guppy fed midge larvae-accumulated 500, 800, and 1,300 micrograms Cd/g for 6 months decreased to 79, 65, and 55% of the control, respectively. Similar effects of Cd on the reproduction of guppy were shown between the guppies fed the Cd-accumulated midge larvae (500 micrograms Cd/g) and exposed to 10 or 20 micrograms Cd/liter for the 6 months. The Cd concentrations of the digestive tract, liver, and kidney increased strongly, indicating that such Cd accumulation was brought on mainly through the Cd-accumulated midges. Mortality of the female guppies fed larvae-accumulated 1,300 micrograms Cd/g increased abruptly from the 6 months of the experiment, whereas no male guppy died during the experiment.

Administration, Oral↗
PubMed1986

Myocardial infarction after acute carbon monoxide poisoning: case report.

A 28-year-old man with acute myocardial infarction after carbon monoxide poisoning is reported. He had chest pain after the exposure to carbon monoxide. The electrocardiogram, serum enzymes, and technetium-99m pyrophosphate scintigrams showed anterior myocardial infarction. The coronary angiogram, which was performed one month after the onset, showed no visible atherosclerotic lesion. As to the cause of myocardial infarction, it is assumed that carbon monoxide reduced the oxygen supply to the myocardium and might induce coronary artery spasm with or without accompanying coronary thrombosis.

Adult↗
PubMed1986

Clinical experience with a new rate-responsive TX pacemaker.

In this report, we describe our initial experience with a new rate-responsive TX pacemaker in 10 patients. This pacemaker system uses a conventional transvenous ventricular electrode, which senses the evoked QT interval after a ventricular paced beat, as an indicator of physiological metabolic demand. Implantation of the TX pacemaker does not differ from that of conventional VVI units, and two special modes are available after implantation: TX and VVI mode. Bicycle ergometer tests showed that significantly higher rate response and exercise ability were achieved during the TX mode compared with the VVI mode (mean maximal heart rate: 115 +/- 13 bpm vs 96 +/- 21 bpm, p less than 0.01, and mean maximal exercise time; 10.7 +/- 3.9 min vs 8.0 +/- 3.8 min, p less than 0.01, respectively). In one patient, cardiac index was measured by a thermodilution method during the bicycle ergometer test, which confirmed that an adequate increase in cardiac index (rest: 3.38 liters/min/m2, vs exercise; 7.34 liters/min/m2) was obtained by an increase of the pacing rate (rest: 72 bpm vs exercise: 128 bpm). Our results show that physiological rate-responsive pacing using the QT interval provides a simple means of increasing the heart rate and cardiac index.

Aged↗
PubMed1985

Importance of coronary collaterals for restoration of left ventricular function after intracoronary thrombolysis.

In an evaluation of the role of coronary collaterals in the early period of acute myocardial infarction (AMI), 30 patients with acute total coronary occlusion treated with intracoronary thrombolysis 2 to 8 hours after the onset of symptoms were studied. Only 13 patients with well-developed collaterals in the early period of AMI and successful thrombolysis showed improvement of global and regional ejection fraction (EF) from the acute phase to the chronic phase (global EF from 50% to 71%, p less than 0.001; regional EF from 25.4% to 49.2%, p less than 0.001). In patients with no or less well-developed collaterals and successful thrombolysis, global and regional EF were similar to those in patients in whom thrombolysis was unsuccessful. Among the 19 patients with successful thrombolysis, there was no significant correlation between the duration of ischemia and the improvement of regional EF (r = -0.03, difference not significant). These data suggest that the extent of coronary collateral vessels in the early period of AMI is an important determinant of restoration of left ventricular function after intracoronary thrombolysis.

Acute Disease↗
PubMed1973

Influence of seasonal changes in climate on dispersal of released Culex pipiens fatigans: a study in villages in Delhi Union Territory, India.

Studies on Culex pipiens fatigans dispersal were conducted during the hot, cold, rainy, and post-rainy seasons in 2 villages in the Delhi area in order to improve techniques and to determine the optimum time of release. Releases from one central point and from a number of points were evaluated. No directional effect on dispersal was observed. Dispersal was most rapid and extensive in the hot season and slowest and most limited during the cold season, when the released mosquitos tended to remain near the release sites. No significant difference was noticed between male and female dispersal, and both sexes showed a uniform dispersal pattern 2 days after release.

Animals↗
PubMed1973

Dispersal and survival in the field of chemosterilized, irradiated, and cytoplasmically incompatible male Culex pipiens fatigans.

Comparative field studies were made on the dispersal and survival of chemosterilized, irradiated, and cytoplasmically incompatible (D3 strain) male Culex pipiens fatigans. There was no significant difference in dispersal patterns and daily survival rates between laboratory colony males and wild males, and between chemosterilized or irradiated males and untreated males. Although there was no difference in dispersal between adults of the D3 strain and the laboratory colony of the Delhi strain, the former had a lower daily survival rate.

Animals↗