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S Sano

Publications and source records attributed to S Sano.

At least 109 records · Page 6Linked to original sources
PubMed1996

A 120-MHz ultrasound probe for tissue imaging.

Ultrasound transducers with center frequency above 100 MHz are expected to be used for future diagnostic tissue characterization because of their high lateral resolution. We have fabricated a 120-MHz transducer that consists of a ZnO piezoelectric film on a sapphire substrate that has a concave acoustic lens. The lateral resolution was calculated as 13 microns. The insertion loss of the transducer, defined as the difference between the received voltage and the transmitted one, was -45 dB. The 6-dB handwidth of the received signal was approximately 40 MHz. The transducer was mounted in a rod-shaped probe to ensure contact with in vivo tissue, because of the low penetration of ultrasound in the high frequency region. While the probe is rotated and moved along its axis mechanically, the transducer receives backscattered ultrasound from the surrounding tissue on a cylindrical plane that is kept a constant distance from the probe surface. The feasibility of this high-frequency tissue imaging probe has been demonstrated by obtaining preliminary images of an in vitro bovine kidney.

Acoustics↗
PubMed1996

Transplantation of the cadaver heart harvested one hour after hypoxic cardiac arrest using the core-cooling technique in dogs.

A shortage of donor organs in clinical transplantation prompted us to study whether resuscitated dead hearts could be utilized for successful orthotopic heart transplantation. After 60 min of hypoxic cardiac arrest, one group of canine hearts was resuscitated (Res group, n = 6). The other group was harvested directly (Non-Res group, n = 6). In the Res group, cardiopulmonary bypass was utilized for resuscitation at 37 degrees C and the animals were then core-cooled to 15 degrees C. The hearts then were preserved in University of Wisconsin solution and orthotopically transplanted. Stable prostacyclin analogue (OP2507) and verapamil, a calcium antagonist, were added to the cardioplegia, and substrate-enriched warm blood cardioplegia and a hydroxy radical scavenger (EPC) were administered at the time of reperfusion of the transplanted heart. All animals in each group were successfully weaned from cardiopulmonary bypass with dopamine (5 micrograms/kg/min). Cardiac function without dopamine was better preserved in the Res group than the Non-Res group (Emax: 130.6 +/- 41.5% vs. 47.1 +/- 24.7%; mean +/- SD, as percent of postbrain death values, P < 0.01 by unpaired t-test). Cadaver hearts 60 min after anoxic arrest can be successfully re-animated and orthotopically engrafted. In addition, the core-cooling technique is useful. We believe this study serves as the key step in the clinical application of dead hearts to successful cardiac transplantation.

Animals↗
PubMed1996

[Evaluation of pulmonary perfusion in a patient with agenesis of the left pulmonary artery: usefulness of radionuclide angiography].

We reported a case with agenesis of the left pulmonary artery, in which radionuclide angiography with 99mTc-HSA and time activity curve (TAC) were useful in evaluating pulmonary perfusion in the effected lung. The case involved a 32-year-old male, who underwent nuclear medicine examination including 99mTc-MAA scanning, 81mKr scanning and 99mTc-HSA angiography. 99mTc-MAA and 81mKr scanning showed the perfusion defect and decreased ventilation in the effected lung, respectively. On the other hand, the delayed images of 99mTc-HSA angiography showed the existence of perfusion in the effected lung, although the early images showed the perfusion defect in the same lung. The TAC whose region of interest was placed on the hilus showed that the effected lung was gradually filled with the blood flow through the collateral pathways. In addition, the ratio of area under the TAC on the contralateral lung versus the effected lung was 4.6, while the volume ratio of the contralateral lung versus the effected lung obtained from X-ray CT images was 2.7. Therefore, it was suggested that the perfusion per volume in the effected lung was decreased, compared with that in the contralateral lung. It was concluded that 99mTc-HSA angiography was useful in evaluating the perfusion of the effected lung in a patient with agenesis of the left pulmonary artery.

Adult↗
PubMed1996

Successful transplantation of cadaver hearts harvested one hour after hypoxic cardiac arrest.

BACKGROUND: A shortage of donor organs in clinical transplantation prompted us to study whether resuscitated "dead" hearts could be used for successful orthotopic heart transplantation. METHODS: Donor hearts were resuscitated with cardiopulmonary bypass after 3 minutes (the control group; n = 8) or 60 minutes (the experimental group; n = 6) of hypoxic cardiac arrest after induction of brain death. RESULTS: All the animals of each group were successfully weaned from cardiopulmonary bypass with 5 micrograms/kg/min of dopamine 1 hour after transplantation, and cardiac function with or without dopamine was better preserved in the experimental group than the control group (with maximum slope of pressure-volume relationship with dopamine: 198.0% +/- 36.8% versus 121.2% +/- 47.2%; maximum slope of pressure-volume relationship without dopamine: 130.6% +/- 41.5% versus 70.8% +/- 21.5% [mean +/- standard deviation] as percentage of values after brain death, respectively; p < 0.01 by unpaired t test). CONCLUSIONS: These results indicate that cadaver hearts 60 minutes after anoxic arrest can be successfully reanimated and orthotopically engrafted with various methods and drugs.

Animals↗
PubMed1996

[Subaortic stenosis].

Explore the source record for details and available documents.

Aortic Stenosis, Subvalvular↗
PubMed1995

A direct demonstration of the catalytic action of monodehydroascorbate reductase by pulse radiolysis.

To elucidate the catalytic mechanism of monodehydroascorbate (MDA) reductase from cucumber, its interaction with MDA radical was investigated by the use of pulse radiolysis. When approximately equimolar MDA radical to the fully reduced MDA reductase was generated, the fully reduced enzyme reacted first with MDA radical to form the red semiquinone, and the semiquinone further reacted with MDA radical to form the oxidized enzyme. At a low ratio (< 20) of MDA radical to enzyme concentration, the fully reduced enzyme reacted quantitatively with MDA radical to form the semiquinone with a second-order rate constant of 2.6 x 10(8) M-1 s-1 at pH 7.4. At excess MDA radical to enzyme concentration, a similar rate constant was obtained from the decay of MDA radical. These results suggest that the reaction of the semiquinone with MDA radical occurs at the same rate or rate-limiting step of the oxidation of the fully reduced enzyme by MDA radical. The rate constants decreased with an increase in NaCl concentration, suggesting that the localization of cationic groups of amino acid residue near the active site may provide electrostatic guidance to the anionic substrate of MDA radical.

Catalysis↗
PubMed1995

Molecular characterization of monodehydroascorbate radical reductase from cucumber highly expressed in Escherichia coli.

Monodehydroascorbate radical (MDA) reductase, an FAD-enzyme, is the first enzyme to be identified whose substrate is an organic radical and catalyzes the reduction of MDA to ascorbate by NAD(P)H. Its cDNA has been cloned from cucumber seedlings (Sano, S., and Asada, K. (1994) Plant Cell Physiol. 35, 425-437), and a plasmid was constructed in the present study that allowed a high level expression in Escherichia coli of the cDNA-encoding MDA reductase using the T7 RNA polymerase expression system. The recombinant MDA reductase was purified to a crystalline state, with a yield of over 20 mg/liter of culture, and it exhibited spectroscopic properties of the FAD similar to those of the enzyme purified from cucumber fruits during redox reactions with NADH and MDA. The red semiquinone of the FAD of MDA reductase was generated by photoreduction. p-Chloromercuribenzoate inhibited the reduction of the enzyme-FAD by NADH, and dicumarol suppressed electron transfer from the reduced enzyme to MDA. The specificity of electron acceptors of the recombinant enzyme appeared to be similar to that of MDA reductase, even though the amino acid sequence encoded by the cDNA was somewhat different from that of the enzyme purified from cucumber fruits. The Km values for NADH and NADPH of the recombinant enzyme indicated a high affinity of the enzyme for NADH. The reaction catalyzed by the enzyme did not exhibit saturation kinetics with MDA up to 3 microM. A second order rate constant for the reduction of the enzyme-FAD with NADH was 1.25 x 10(8) M-1 s-1, as determined by a stopped-flow method, and its value decreased with increases in ionic strength, an indication of the enhanced electrostatic guidance of NADH to the enzyme-FAD.

Cloning, Molecular↗
PubMed1995

Effects of bidisomide (SC-40230), a new class I antiarrhythmic agent, on ventricular arrhythmias induced by coronary artery occlusion and reperfusion in anesthetized rats; comparison with mexiletine and disopyramide.

We investigated the antiarrhythmic effects of bidisomide (SC-40230), a new class I antiarrhythmic drug, in early-phase ventricular arrhythmias induced by coronary artery occlusion and reperfusion in anesthetized rats. The effects of bidisomide were compared with those of mexiletine (MXT) and disopyramide (DSP), established class I antiarrhythmic drugs. Drugs were administered intravenously, 5 min before induction of coronary occlusion. Bidisomide (5 mg/kg) reduced the number of premature ventricular complexes and the incidence of ventricular tachycardia and ventricular fibrillation similarly to MXT and DSP in rats with ventricular arrhythmias induced by coronary artery occlusion. In rats with ventricular arrhythmias induced by coronary artery reperfusion following a 5-min coronary occlusion, the antiarrhythmic effects of 5 mg/kg of bidisomide were similar to those of the same doses of MXT and DSP. All three drugs significantly slowed the heart rate. Our results suggest that bidisomide may effectively reduce the severity of life-threatening ventricular arrhythmias that occur during acute coronary syndrome.

Animals↗
PubMed1995

Detection of "pathologic" prosthetic valve stenosis via exercise Doppler echocardiography.

To detect borderline mitral valve dysfunction in asymptomatic patients, with Björk-Shiley valves, we studied the patients' hemodynamics at rest and during exercise by Doppler echocardiography. Supine bicycle exercise was performed by 65 patients. The patients were divided into two groups according to the measurements of the exercise Doppler echocardiography: a normally functioning group (n = 45) and a borderline group (n = 20). The valve area at rest was 2.0 +/- 0.6, 2.1 +/- 0.7, and 2.3 +/- 0.5 cm2 with valve sizes of 25, 27, and 29 mm, respectively, in the normal group and 1.9 +/- 0.5, 1.9 +/- 0.4, and 2.1 +/- 0.3 cm2 in the borderline group. The mitral valve area did not significantly change with exercise in either group. In the normal group, peak gradients increased from 9.9 +/- 3.5, 9.7 +/- 1.1, and 9.5 +/- 1.6 mmHg with valve sizes of 25, 27, and 29 mm, respectively, at rest to 15.1 +/- 3.1, 14.0 +/- 3.3, and 14.8 +/- 2.6 mmHg with exercise. Mean gradients increased from 5.2 +/- 1.2, 5.9 +/- 1.3, and 5.8 +/- 1.8 mmHg with valve sizes of 25, 27, and 29 mm, respectively, at rest to 8.0 +/- 2.5, 9.1 +/- 2.0, and 8.8 +/- 1.6 mmHg with exercise. In the borderline group, peak gradients increased from 10.5 +/- 3.1, 10.1 +/- 2.1, and 10.8 +/- 1.7 mmHg with valve sizes of 25, 27, and 29 mm, respectively, at rest to 24.5 +/- 4.2, 23.6 +/- 4.4, and 22.4 +/- 3.2 mmHg with exercise.(ABSTRACT TRUNCATED AT 250 WORDS)

Echocardiography, Doppler↗
PubMed1995

Enhancement in gastric mucosal EGF and PDGF receptor expression with ulcer healing by sulglycotide.

1. The effect of an antiulcer agent, sulglycotide, on mucosal expression of EGF and PDGF receptors with chronic ulcer healing was investigated. 2. Rats with experimentally-induced gastric ulcers were treated twice daily for 14 consecutive days, either with sulglycotide at 200 mg/kg or vehicle, and at different stages of treatment used for quantitation of gastric mucosal EGF and PDGF receptors. 3. The ulcer healing was accompanied by an increase in mucosal expression of both types of receptors. A 1.8-fold increase in EGF and 3.1-fold increase in PDGF receptors occurred by the 4th day following the development of ulcer and reached a maximum of 2.4-3.9-fold increase by the 10-14th day. 4. Treatment with sulglycotide caused accelerated ulcer healing accompanied by a significant enhancement in the receptors expression. A 2.3- and 3.6-fold increase in EGF and PDGF receptor expression occurred by the 4th day of sulglycotide treatment, reaching a 5.5- and 5.6-fold respective increase by the 10th day when the ulcer essentially healed. 5. The results attest to the ability of sulglycotide to stimulate the gastric mucosal proliferative activities associated with ulcer healing.

Acetates↗
PubMed1995

Quality of peptic ulcer healing induced by lansoprazole and roxatidine.

This study reports preliminary results of a controlled, multicenter trial on the quality of ulcer healing induced by lansoprazole (LPZ) or roxatidine (R) in gastric ulcer (GU) or duodenal ulcer (DU) patients. Group A received LPZ 30 mg q.d. and group B received R 75 mg b.i.d. All drugs were given for 8 weeks in GU and for 6 weeks in DU. Endoscopy and gastric biopsy were performed to detect Helicobacter pylori before and on completion of treatment. The healing rates of groups A and B were 100 and 69.2%, respectively, in GU and 100 and 70.0%, respectively, in DU. This difference (p < 0.01) was significant between the two groups in GU. There was no significant difference between the two groups in the S2 stage shift rate in GU and DU. The H. pylori clearance rates of groups A and B were 33.3 and 20.0%, respectively, in GU and 62.5 and 33.3%, respectively, in DU. The differences in treatment response (healing rates and S2 shift rates) between the LPZ group and the R group may be related to the differences in suppression of acid secretion and in bactericidal effects on H. pylori.

2-Pyridinylmethylsulfinylbenzimidazoles↗
PubMed1995

Evaluation of St. Jude Medical mitral valve function by exercise Doppler echocardiography.

The aim of this study was to detect borderline mitral valve dysfunction in 100 asymptomatic patients with a St. Jude Medical valve. We studied rest and exercise hemodynamics by Doppler echocardiography. Study patients were divided into two groups according to the time since surgery: group A had valves implanted less than 5 years ago (44 patients), group B had valves implanted more than 5 years ago (56 patients). Although patients had no clinical signs of valve dysfunction, group B was found to have significant reduction of mitral valve area (p < 0.05). In the group A patients, mean gradients at rest increased from 4 +/- 2, 4 +/- 2, and 3 +/- 1 mmHg in valve sizes of 25, 27, and 29 mm, respectively, to 7 +/- 2, 7 +/- 3, and 5 +/- 2 mmHg with exercise. In the group B patients, mean gradients at rest increased from 7 +/- 1, 6 +/- 2, and 5 +/- 1 mmHg to 14 +/- 3, 13 +/- 3, and 10 +/- 4 mmHg, respectively, after exercise. The percent increase (mean) in peak pressure gradient with exercise was significantly higher in group B (more than 100%) than in group A (less than 80%) (p < 0.01). The percent increase in mean gradient with exercise was also significantly higher in group B (more than 100%) than in group A (less than 75%). In conclusion, patients with reduced valve area and more than a 100% increase of peak and mean gradients should be followed up carefully. If any signs or symptoms of heart failure develop, they must be considered as candidates for surgery.

Adult↗
PubMed1995

[Fontan-type procedure for an adult case of double-outlet right ventricle (S, D, L)].

The double-outlet right ventricle with L-malposition (DORV (S, D, L)) is one of the rare congenital heart diseases. Intracardiac rerouting with a internal conduit has been indicated in principle to it as the radical operation. DORV (S, D, L) is often combined with the pulmonic stenosis (PS), and Rastelli's operation is indicated to the case in which release of PS is difficult. We report a case of DORV (S, D, L) combined with PS and the hypoplastic right ventricle which is treated by the Fontan-type procedure. The patient was a 35-year-old female who had undergone Glenn's operation at 10 years of age under the diagnosis of transposition of the great arteries. Recently she complained of aggravation of the cyanosis and dyspnea on exertion. After thorough examinations, the disease was diagnosed as DORV (S, D, L) with doubly committed VSD which was combined with severe PS, hypoplastic right ventricle (29% of normal) and left-sided juxtaposition of atrial appendages. The development of her distal pulmonary arteries was estimated well enough (PA-index 448 mm2/m2). We judged that intracardiac rerouting with an internal conduit could not be applied due to her severe pulmonic stenosis, and that Rastelli's operation as the biventricular repair was also impossible because of her hypoplastic right ventricle. Thus we adopted the Fontan-type procedure with a new septation in the right atrium, namely oblique partition, and attained a good result. To our knowledge, this case is the fourth case report in Japan of DORV (S, D, L) treated with the Fontan-type procedure.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

[Complete resection of superior mediastinal seminoma, following reconstruction of superior vena cava--a case report].

The patient was a 37-year-old man with superior mediastinal seminoma, which invaded the bilateral brachiocephalic vein, superior vena cava, pericardium and left lung. These invaded organs were resected with the tumor and a vascular reconstruction was performed with EPTFE graft and pericardial patch. EPTFE graft was interposed between the left brachiocephalic vein and right atrium. Superior vena cava was reconstructed by means of pericardial patch. Histologically, the tumor was diagnosed as pure seminoma. He received the prophylactic irradiation (45 Gy). Although venography two years after operation demonstrated the obstruction of the EPTFE graft and marked stenosis of the pericardial patch, the patient remains free from the symptom and is doing well without recurrence 45 months after operation.

Adult↗
PubMed1995

Clinical application of the Diapason hook system: a preliminary case report.

A preliminary case report of the clinical application of the Diapason hook system is discussed. The hooks were implanted in six patients for the fixation of the thoracic region (n = 3), the prevention of backout of pedicular screws (n = 3), and repair of the pars interarticularis (n = 1); the patients were followed for more than 6 months after the surgery. Results indicate that in all of the cases the initial purpose of the Diapason hook system was served. The advantages of the Diapason screw and hook system are its titanium alloy material and simplicity in implanting. Although there have been no instrument failures or any other complications, the cases need longer follow-up. In addition, the size of some hooks needs to be improved because they were too large to apply to the short segments.

Adolescent↗
PubMed1995

[A surgical repair of partial anomalous pulmonary venous drainage to the high superior vena cava].

A 7-year-old boy with partial anomalous pulmonary venous drainage to the high superior vena cava (SVC) underwent surgical repair by Williams procedure. Right upper pulmonary vein was drained to the left atrium via the SVC and the surgically enlarged sinus venosus type ASD. SVC was ligated and divided. SVC was then anastomosed to RA appendage pedicle directly. Autologous pericardium was patched anteriorly to create a new SVC pathway. The postoperative course was uneventful without arrhythmia and cardiac catheterization 1 month postoperation revealed no stenosis of the SVC and right upper pulmonary venous return.

Anastomosis, Surgical↗