Search PubMed⌕ Search

Biomedical subjects

Y Hirota

Publications and source records attributed to Y Hirota.

656 records · Page 37Linked to original sources

The effects of epinephrine and norepinephrine administered during local anesthesia on left ventricular diastolic function.

To evaluate the effects of epinephrine (E) and norepinephrine (NE) administered during local anesthesia on left ventricular diastolic function, we examined transmitral inflow patterns with pulsed Doppler echocardiography. Arterial blood pressure, heart rate, and transmitral inflow patterns were measured in 10 healthy volunteers when 3.6 mL of 2% lidocaine containing 1:80,000 E or 1:25,000 NE was injected supraperiosteally in the maxilla. The dosage of drug administered was 45 micrograms for E and 144 micrograms for NE. After the administration of E, heart rate was increased, but blood pressure was unchanged. Peak early velocity (R), peak atrial velocity (A), the ratio of A to R (A/R), and the deceleration rate (Dc) were increased, whereas the isovolumic relaxation time (IVRT) was shortened. The increase of R and Dc and the shortening of IVRT indicated an activation of left ventricular relaxation. After the administration of NE, blood pressure was increased and heart rate was decreased. A decrease in Dc, shortening of the acceleration half-time (AcT), and prolongation of IVRT were observed. These changes reflect impeded myocardial relaxation. We conclude that E activates left ventricular diastolic function and that NE, in contrast, impairs it.

Adult↗

Coronary-subclavian steal corrected with percutaneous transluminal angioplasty.

We describe a case of coronary-subclavian steal syndrome treated with percutaneous transluminal angioplasty. A 58-year-old female who had her first coronary bypass operation 6 years previously and a second operation 3 years previously involving the left internal mammary artery and right gastroepiploic artery, developed unusual angina on effort characterized by left precordial pain, pain in the left shoulder and arm, tinnitus and dizziness. Angiography revealed retrograde flow to the left subclavian artery via the left vertebral artery and left internal mammary artery. Severe stenosis of the left subclavian artery was demonstrated at its ostium. Restoration of antegrade flow to the vertebral artery and left internal mammary artery by transluminal angioplasty resulted in complete resolution of these symptoms.

Angina Pectoris↗

Use of gastroepiploic and internal mammary arteries for myocardial revascularization.

Triple coronary artery bypass grafting utilizing the right gastroepiploic artery and both internal mammary arteries was performed successfully in a 37-year-old male, achieving primary myocardial revascularization. All grafts were in situ. The right gastroepiploic artery was anastomosed to the posterior descending artery. The right and left internal mammary arteries were anastomosed to the left anterior descending artery and the posterolateral branch, respectively. The postoperative angiogram showed good patency of all grafts. The patient recovered uneventfully with resolution of his angina pectoris.

Adult↗

Evaluation of prototype equipment for digital subtraction angiography in diagnosing intracranial lesions.

Two prototype units for digital subtraction angiography have been developed by Japanese manufacturers. Their performance in demonstrating various intracranial lesions in 121 patients was evaluated. Comparison with conventional selective catheter angiography was possible in 77 patients. Digital subtraction angiography proved useful in preoperative evaluation of pituitary tumors when transsphenoidal surgery was being considered; demonstration of faint tumor stains which might be missed on conventional angiography; demonstration of larger aneurysms, arteriovenous malformations, and tumors as a screening technique; demonstration of abnormalities involving the dural sinuses; and follow-up of patients after surgery or embolization.

Brain Diseases↗

Susceptibility to Eimeria tenella of chickens and chicken embryos of partly inbred lines possessing homozygous major histocompatibility complex haplotypes.

Susceptibility to Eimeria tenella infection of chicken embryos and chickens of partly inbred lines possessing different major histocompatibility complex haplotypes was investigated. Chicken embryos of line H-B2 possessing B2 homozygous haplotype showed lower mortality and higher oocyst production than embryos of line H-B15 possessing B15 homozygous haplotype. Embryos of line H-B2 chickens were considered more resistant to E. tenella infection than those of line H-B15. Seven days after 10-day-old chickens were infected with E. tenella, the two lines showed no significant differences in percent bodyweight gain, cecal lesion score, and oocyst production; they differed significantly only in cecal shrinkage. Results suggest that the B system affects chicken embryos and chickens differently in susceptibility to E. tenella infection.

Animals↗