Biomedical subjects

S Teramoto

Publications and source records attributed to S Teramoto.

At least 19 recordsLinked to original sources

PubMed1992

Novel positive inotropic agents: synthesis and biological activities of 6-(3-amino-2-hydroxypropoxy)-2(1H)-quinolinone derivatives.

A series of 6-(3-amino-2-hydroxypropoxy)-2(1H)-quinolinones has been synthesized and evaluated for positive inotropic activity on the canine heart. Some of these derivatives have a potent activity with none or negative chronotropic effect in isolated, blood-perfused dog heart preparations. They also display a high selectivity for positive inotropic effect over chronotropic and vasodilatory effects in anesthetized dogs. (+/-)-6-[2-Hydroxy-3-[(3-methoxybenzyl)amino]propoxy]-2(1H)-quinolinone (39) and (+/-)-6-[3-(3,4-dimethoxybenzyl)amino]-2-hydroxypropoxy]-2 (1H)-quinolinone (40) were further investigated in conscious dogs. After iv administration, they did not affect heart rate or mean blood pressure at the dose producing a 50% increase in the peak of the first derivative of the left ventricular pressure. The compounds (39, OPC-18750, and 40, OPC-18790) are the most promising agents with desirable biological activities, and now are currently undergoing clinical evaluation.

Animals↗

PubMed1992

Outcome of patients with lung cancer detected via mass screening as compared to those presenting with symptoms.

We performed lung cancer resection in 721 patients between 1980 and 1989. Cancers were detected via mass screening programs by annual chest X-ray examination in the majority of cases. We evaluated the surgical results in patients with tumors detected by mass screening and compared them to those in whom the malignancy was detected by symptoms. Lesions in the mass screened group were T1 to T2 tumors in 90% of the cases, and NO in 73%. Stage I disease accounted for 65.3% in the mass screened group. The overall 5-year survival rate was 56.2% in the mass screened group, which was significantly better than the 25.3% for the symptom group (P less than 0.001). The surgical results in the lung cancer cases detected by the mass screening program had better results than the cases who presented with symptoms.

Aged↗

PubMed1992

Transsternal thoracotomy for bilateral pulmonary metastasis.

Advances in the surgical treatment of primary malignancies and the recent chemotherapy have led to an expansion of the surgical treatment of metastatic lung tumors. However, multiple pulmonary metastases are often found and may affect both lungs. It is difficult to reach tumors in the posterior parts of the lung when using a common midsternal approach, especially lesions located in the left lower lobe. We performed transsternal simultaneous bilateral thoracotomy on 10 patients with bilateral lung tumors (9 bilateral metastatic pulmonary tumors and 1 bilateral primary lung cancer). This procedure provides a wide operative field and is an effective method of thoracotomy for patients with bilateral lung tumors. In future, this method should be more actively performed for patients in whom it is indicated.

Adolescent↗

PubMed1992

The use of a biventricular assist device for postcardiotomy profound biventricular failure.

A 58-year-old woman who could not be weaned from cardiopulmonary bypass was treated with a biventricular assist device (BVAD) using a centrifugal pump for the left side and a pneumatic pulsatile pump for the right side. At the initiation of the BVAD support, predominant right ventricular failure was recognized and therefore weaning was begun from the left side. The left ventricular assist device was discontinued after 87 h and the patient was finally weaned from the right ventricular assist device after 205 h. Despite the complete recovery of cardiac function, the patient developed renal failure followed by an intractable infection and died of multiple organ failure on the 59th postoperative day (POD).

Aortic Valve↗

PubMed1992

Multivessel coronary revascularization with bilateral internal thoracic artery grafts.

Sixteen patients underwent coronary revascularization with bilateral internal thoracic artery (ITA) grafts between 1988 and 1989 at the Okayama University Hospital. A total 39 coronary grafts were performed, being an average of 2.4 grafts per patient. Each patient received bilateral ITA grafts, and in 5 patients an additional 7 grafts were constructed with 5 autologous veins and 2 gastroepiploic arteries. The right ITA was grafted as a free graft in 4 patients. The ITA graft patency rate was 96.8 per cent (31/32) at the time of hospital discharge. The postoperative morbidity included one reoperation for bleeding and one myocardial infarction. Coronary artery bypass grafting with bilateral ITA grafts can be safely performed and its application facilitates complete revascularization with arterial grafts.

Aged↗

PubMed1992

Inhibition of mouse alveolar macrophage production of tumor necrosis factor alpha by acute in vivo and in vitro exposure to tobacco smoke.

We investigated the effects of tobacco smoke exposure on the production of tumor necrosis factor alpha (TNF alpha) by alveolar macrophages (AM) in mice (C57BL/6). The results obtained are as follows: (1) In vivo tobacco smoke exposure caused a significant decrease in the production of TNF alpha by AM with the stimulation of lipopolysaccharide (LPS; control group: 19.32 +/- 5.52 U/ml, smoked group: 4.28 +/- 0.98 U/ml; p less than 0.05). (2) In vitro exposure of AM to tobacco smoke extracts (water-soluble extracts) also caused a decrease in the production of TNF alpha up to 93% of control with stimulation of LPS (p less than 0.05) without any decrease in cellular viability. We concluded that the production of TNF alpha by AM was impaired by smoking via direct action of the factors present in tobacco smoke.

Animals↗

PubMed1992

Quantitative assessment of dyspnea during exercise before and after bullectomy for giant bulla.

Incremental exercise testing using a cycle ergometer was performed in eight patients with giant bulla before and after bullectomy to assess dyspnea. There was a significant positive linear relationship between dyspnea expressed in the Borg scale (BS) and oxygen consumption (VO2) during exercise in all subjects. From these correlations, we introduced the following three new parameters for quantitative assessment of dyspnea: the Borg scale slope (BSS); the threshold load of dyspnea (TLD); and the breakpoint load of dyspnea (BLD), representing the slope of the regression line, onset of dyspnea on the regression line, and the maximum oxygen consumption before the subjects interrupted exercise, respectively. After surgery, the BSS showed marked decrease, and the TLD and BLD showed significant increase. Therefore, the reduction in the dyspnea with peak exercise after surgery was thought to be, at least in part, based on the delay of dyspnea onset, the decrease in dyspnea sensitivity, and the improvement in exercise capacity. The improvement in dyspnea during exercise in patients with giant bulla after surgery was extensively evaluated by newly introduced parameters based on BS-VO2 regression line.

Blister↗

PubMed1992

The effects of radical scavengers and leukocyte-depleted blood on reperfusion injury of extirpated rabbit lung.

Oxygen radicals produced by polymorphonuclear leukocytes were considered primarily responsible for reperfusion injury in lung transplantation. Using the extirpated rabbit lungs as a transplant model, we measured lung water volume, the oxygen radicals of lung tissue using a direct method (electron spin resonance) and an indirect method (measurement of peroxide lipids). The effects of free radical scavengers, human superoxide dismutase (h-SOD) and catalase (CAT), and leukocyte-depleted blood on reperfusion injury were evaluated in three experimental groups. Group I (n = 8, control): Lung reperfusion was performed with blood from other rabbits. Group II (n = 7): Immediately before reperfusion, h-SOD (1,500 u/ml) and CAT (3,000 u/ml) were added to the blood. Group III (n = 7): Reperfusion was performed with the leukocyte-depleted blood. Severe pulmonary edema and an elevation of malondialdehyde (MDA) occurred in Group I. In Group II, addition of radical scavengers to the reperfusion blood produced only mild pulmonary edema, but an elevation of MDA occurred as in Group I. In Group III, pulmonary edema and MDA elevation were almost completely suppressed.

Animals↗

PubMed1992

Experimental tracheal allotransplantation using omentopexy: histological process of rejection reaction without immunosuppression.

A large defect in the thoracic trachea was produced by resecting 10 rings of tracheal cartilage in each of 11 adult mongrel dogs. An allograft of the five tracheal rings was interposed in this site via end-to-end anastomosis and then wrapped with the pedicled omental flap. These animals received no immunosuppressive therapy. The pseudostratified tracheal epithelia were remained and the graft revascularization through the omental pedicle proved to be established within about one week after surgery without immunosuppression. Marked mononuclear cell infiltration was observed beneath the epithelia and around the capillaries in the subepithelial layer over one week after surgery, which was followed by phagocytosis of the tracheal cartilages by macrophages. After the completion of rejection reaction, inflammation finally induced scarring or necrosis of the tracheal allograft, resulting in asphyxia or perforation. Only one animal survived 71 days after surgery without graft trouble. However, even in this animal, weak rejection reaction was observed microscopically and the structure of the graft was not that of the normal trachea. We think these results suggest that allotransplantation of trachea induces rejection, and therefore, that the use of immunosuppressants is necessary.

Animals↗

PubMed1992

Indications and timing of surgery for cholelithiasis associated with valvular heart disease.

Twenty patients with cholelithiasis associated with valvular heart disease were studied to assess the need and the optimal time for cholecystectomy. Twelve patients (11 symptomatic and 1 asymptomatic patients) underwent cholecystectomy. The remaining patients were asymptomatic. The levels of the total bilirubin in 9 patients, and of LDH in 15, were higher than normal. In most of the patients, the serum transaminase levels were higher than normal, but in few cases, the levels were higher than 200 IU/l. These abnormal values, however, were not consistently observed in these patients. No clear association between the type and form of valvular heart disease was demonstrated. The type of prostheses used for valve replacement in these patients were ball, tilting disc and leaflet. No significant differences in efficacy were observed among different types of prostheses. The incidence of silent stones is high in patients with valvular heart disease and heart surgery often causes deterioration in patients with cholelithiasis. The recovery of the patients who underwent cholecystectomy before valve replacement were better than those who underwent cholecystectomy after heart surgery. In conclusion, therefore, patients showing any abnormal results in liver function tests should be assessed in detail by abdominal echography and should receive surgical treatment of biliary tract before heart surgery if necessary.

Cholelithiasis↗

PubMed1992

Long-term results of surgery for mitral regurgitation due to mitral valve prolapse: a comparison of valve replacement and annuloplasty.

Patients with mitral regurgitation (MR) due to mitral valve prolapse operated at the Second Department of Surgery, Okayama University Medical School, between 1976 and 1986 were divided into two groups. The first consisted of 20 patients who had mitral valve replacement (MVR) and the second 15 patients who had mitral annuloplasty (MAP). Long-term results of surgery, cardiac function, hemodynamic status, and surgical findings were compared between the two groups. Before surgery, there were no significant differences in patient's clinical status and cardiac function between the two groups. However, after surgery statistically significant differences emerged between the two groups in ejection fraction (EF), cardiac index (CI) and mean circumferential fiber shortening velocity (mVcf). Left ventricular pumping function and myocardial contractile force tended to decrease after surgery in the MVR group and to remain unchanged or even increase in the MAP group indicating that valve preservation procedures should be selected as often as possible for the patients involved in mitral valve prolapse.

Adolescent↗

PubMed1992

Mechanical circulatory support with a centrifugal pump after open heart surgery.

Since December 1988, a centrifugal ventricular assist device (VAD) was used to support the circulation in 5 patients who could not be weaned from cardiopulmonary bypass (CPB) or developed cardiogenic shock after removal from CPB. Three patients required a left VAD, one needed a right VAD. One patient had biventricular support using a centrifugal left VAD and a diaphragm type right VAD. The duration of the centrifugal VAD support ranged from 6 to 136 (mean 72)h. All patients were weaned from the VAD, but only 2 patients were discharged from the hospital. Two patients died of multiple organ failure, and one died of cardiogenic shock caused by intractable arrhythmia. Infection occurred in all non-survivors, and 2 of them developed renal failure. We conclude that the centrifugal VAD is effective to recover a failing ventricle. The factors related to the unsuccessful recovery were delayed start of the VAD support and major complications such as infection as infection and renal failure.

Adult↗

PubMed1992

Factors influencing the efficacy of DeVega's annuloplasty for secondary tricuspid regurgitation.

DeVega's annuloplasty was performed on 41 patients with tricuspid regurgitation (TR) associated with combined valvular disease and results were assessed based on Doppler echocardiographic findings in an attempt to examine the applicability of this surgical technique. TR was quantitatively evaluated via Doppler echocardiography before and after surgery. Clinical symptoms, cardiac function, and surgical results were assessed, and the severity of left ventricular myocardial degeneration was determined using electron microscopy. There were no differences in the following factors between the TR recurrence and TR improvement groups: previous heart surgery, number of involved valves, presence or absence of a giant left atrium, preoperative New York Heart Association (NYHA) functional class, and type of prosthetic valve (Björk-Shiley vs. St. Jude Medical). We found no differences between these two groups in TR severity and tricuspid annulus diameter measured during surgery. Severity of myocardial degeneration was closely associated with the recurrence of TR. Clinically, most had diminished cardiac function before surgery. DeVega's technique appears to be remarkably effective in patients with well-preserved myocardium because no TR recurrence was detected even in examinations with the most accurate Doppler echocardiography. However, such long-term effectiveness of DeVega's technique cannot be expected in patients with degenerated myocardium.

Adult↗

PubMed1992

A case of trans-sternal bilateral thoracotomy for bilateral lung cancer.

Trans-sternal bilateral thoracotomy was performed to resect the right upper lobe and the left S1 + 2 + S3, and to complete lymphadenectomy in a 35-year-old female case of lung cancer in whom multiple lesions were suspected. Trans-sternal bilateral thoracotomy was considered to be useful for one-stage surgery in patients in whom bilateral lung cancer is suspected or confirmed, because it provides a sufficient surgical field enabling the resection of lung and lymph nodes. This may be the first case report of trans-sternal bilateral thoracotomy to treat multiple primary lung cancer.

Adenocarcinoma↗

PubMed1992

Hemodynamic performance of the biventricular bypass system operated in an independent variable rate mode.

The present study was undertaken to determine whether a biventricular bypass system operated in an independent variable rate (VR) mode can maintain the entire circulation. Two pusher-plate pumps which incorporated the Hall effect position sensors were used to bypass the right and left ventricles in 10 sheep under fibrillation. The flow distributions of the pump output to the carotid and renal arteries were investigated every 6 h using ultrasonic blood flow meters for 24 h in 5 animals, and the controllability of the VR mode was evaluated in 5 long-term experiments. The carotid artery flow ratio to the pump output decreased significantly from 4.7 +/- 0.8% before the bypass to 2.7 +/- 0.9% after 24 h. However, the renal artery flow ratio did not change throughout the experiments. In the long-term experiments, the animals were kept alive from 3 to 48 days (mean 15.6 days). The mean pump output had been maintained at more than 90 ml/min/kg for the first 7 days. After the surgery, the pump driving conditions were not readjusted in any experiment. The results indicate that the biventricular bypass system operated in the independent VR mode automatically maintains the entire circulation at a satisfactory level.

Animals↗

PubMed1992

Influences of ventricular pacing on hemodynamics, myocardial metabolism, and cardiac work efficiency: potential risks of rate-responsive ventricular pacing.

The influences of ventricular pacing at a rate of 70 beats/min (bpm) on the systemic and coronary hemodynamics, myocardial metabolism, and cardiac work efficiency were evaluated in five patients with bradycardia. The results were compared to those obtained in six normal subjects at rest. In order to elucidate the effects of a relatively high rate of ventricular pacing, cardiovascular and metabolic variables were also obtained at 120 bpm in the normal subjects. It was observed that the patients eventually benefited from ventricular pacing at a rate of 70 bpm and improved in systemic hemodynamics. Although coronary hemodynamics and myocardial metabolism were accelerated, the cardiac work efficiency was not improved. A pacing rate of 120 bpm in the normal subjects did not appear to accelerate systemic hemodynamics, but adverse accelerations of coronary hemodynamics and myocardial metabolism were observed, and the cardiac work efficiency was remarkably reduced as a result. Our observations indicated that the coronary reserve capacity was very important for ventricular pacing, and suggested that an undue increment of the pacing rate not only might be meaningless but also might induce ischemic angina. Therefore, we should be cautious in using a rate-responsive pacing mode, particularly in determination of the upper limit of pacing rates, although many benefits with this pacing mode have recently been advocated.

Adult↗

PubMed1992

Effect of left atrial plication for the giant left atrium on left ventricular function.

Left atrial plication (LAP) following Kawazoe's method was performed on eight patients with mitral valve stenosis associated with a giant left atrium. To investigate the effect of LAP particularly on left ventricular function, the preoperative and postoperative left ventricular function in these patients were compared. The data were also compared to that of the non-left atrial plication (non-LAP) group with left atrial dimension of 60 mm or over. In the LAP group, there were significant differences between preoperative and postoperative data in the following parameters; New York Heart Association (NYHA) class, cardiothoracic ratio, mean pulmonary arterial pressure (PAP), left ventricular end-diastolic pressure (LVEDP), left atrial dimension, stroke volume index, ejection fraction and cardiac index. On the contrary, in the non-LAP group, there were significant differences between preoperative and post-operative data in the following two factors; NYHA class and PAP. The size of the left atrium in the non-LAP group remained unchanged over the course of long-term follow-up. Despite severe clinical symptoms and severely reduced cardiac function of the patients in the LAP group, cardiac function in all patients improved satisfactorily. This suggests that left atrial plication has a considerably beneficial effect on left ventricular function, and therefore, may be recommended for patients with a giant left atrium.

Adult↗

PubMed1992

Experimental study on veno-venous extracorporeal membrane oxygenation for respiratory failure after lung transplantation.

Extracorporeal Membrane Oxygenation (ECMO) has been adopted as a means of strong respiratory support. In lung transplantation, reimplantation response is still a serious problem. It causes severe respiratory failure which is refractory to mechanical ventilation in some cases. The purpose of this study was to evaluate the effects of veno-venous ECMO after lung transplantation using a canine autotransplantation model. The autotransplantation model was created by keeping the left lung in a warm ischemic state for 2 h. After reperfusion, the right pulmonary artery was ligated. The following two groups were studied: Group 1, Control group, (no ECMO group) (n = 6). After reperfusion, both lungs were ventilated without ECMO. Group 2, ECMO group (n = 7). After reperfusion, veno-venous ECMO support was introduced with reduction of mechanical ventilation. In the no ECMO group, four of the animals died within 210 min after reperfusion. In the ECMO group, two of the animals died of severe pulmonary edema. Data of blood gas analyses (PaO2, PaCO2, and SvO2) after reperfusion were significantly better in the ECMO group, whereas there were no significant differences in both shunt fraction and pulmonary vascular resistance index. In this model with severe pulmonary edema induced by warm ischemia, veno-venous ECMO contributed to the improvement of hypoxemia and hypercapnia, but did not improve pulmonary hemodynamics.

Animals↗