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Biomedical subjects

T Yanaga

Publications and source records attributed to T Yanaga.

70 records · Page 4Linked to original sources
PubMed1977

Echocardiogram before and after subtotal thyroidectomy for hyperthyroidism.

Myocardial contractility was estimated in 27 patients with hyperthyroidism (10 men and 17 women, aged from 16 to 38) by echocardiography. Echocardiographic examination was performed before and on the 7th day after the subtotal thyroidectomy. Thyroid functions (PBI, T3, and T4) decreased significantly after the operation (p less than 0.01). Heart rate and systolic blood pressure showed a slight decrease (N.S.), while diastolic blood pressure showed a slight increase (N.S.), while diastolic blood pressure showed a slight increase (N.S.). Mean AWVs decreased from 35.8 +/- 7.0 mm/sec to 27.6 +/- 5.7 mm/sec and correlated wtih T3 (r=0.4008, p less than 0.05). Mean PWV's also decreased from 53.2 +/- 12.2 mm/sec to 45.2 +/- 11.4 mm/aec and correlated with T3 (r=0.5237, p less than 0.02). DDR decreased from 108.0 +/- 36.8 mm/sec to 85.7 +/- 31.7 mm/sec and correlated wtih T3 (r=0.4008, p less than 0.05). Above results suggest that enhanced myocardial contractility and elevated rate of ventricular filling in hyperthyroidism are suppressed after the operation, and that echocardiography is useful for the evaluation of the clinical course after the operation.

Adolescent↗
PubMed1977

Recording of the fourth heart sound by the signal averaging method. Preliminary report.

The fourth heart sound was clearly recorded by using the signal averaging method. Furthermore, the simultaneous recording of the Doppler signal with the fourth heart sound was performed. Thus, it was demonstrated that the Doppler signal started after the P wave and followed by the fourth heart sound. In 2 cases, the effect of the double Master's test and taking a bath was studied on the computer averaged phonocardiogram. After the exercise, the amplitude of the fourth heart sound was increased, whereas after taking a bath it was almost unchanged. The above results show that the simultaneous recordings of a computer averaged phonocardiogram and Doppler signal that is associated with cardiac activity can greatly facilitate the interpretation of small vibrations such as the fourth heart sound.

Activities of Daily Living↗
PubMedDate not supplied

Chronic low-dose treatment with enalapril induced cardiac regression of left ventricular hypertrophy.

Numerous studies suggest that the renin angiotensin system (RAS) is involved in the development of cardiac hypertrophy. In the present study we produced cardiac hypertrophy in rats subjected to abdominal aortic banding and also induced cardiac regression by the administration of an angiotensin converting enzyme (ACE) inhibitor, enalapril, at 3, 10 and 30 mg/kg/day. Each drug was administered to the rats for 6 weeks from 6 weeks after aortic banding. The left ventricular weight significantly decreased at 10 and 30 mg/kg/day of enalapril as well as the systolic blood pressure. Using the reverse transcriptase polymerase chain reaction, the increased levels of ACE and AT1 mRNA were significantly inhibited in the aortic banding rats treated with the above concentrations of enalapril. The ACE activity in both the plasma and heart tissue preparations was significantly inhibited by enalapril. Similar observations were also seen after the administration of angiotensin type 1 receptor blockade, E-4177, into the aortic banding rats. The treatment with enalapril at 3 mg/kg/day did not reduce the left ventricular weight or the systolic blood pressure in the aortic banding rats. However, this low-dose treatment did significantly decrease the left ventricle to body weight ratio in the aortic banding rats without a reduction of the systolic blood pressure. Therefore, using the low-dose enalapril, the ACE activity in plasma was in part inhibited and the levels of ACE mRNA also decreased in the heart tissue of aortic banding rats, while the level of AT1 mRNA showed no such decrease. These results thus indicate that chronic ACE inhibitor at low doses has a beneficial effect on the regression in the pressure-induced cardiac hypertrophy. It is thus assumed that this effect may also contribute to the presence of an alternate pathway for the conversion of angiotensin I to angiotensin II which might also act as a possible mechanism for cardiac regression.

Angiotensin Receptor Antagonists↗