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Biomedical subjects

K Sakata

Publications and source records attributed to K Sakata.

At least 361 records · Page 20Linked to original sources
PubMed1991

[Assessment of therapeutic effects of cisplatin-phosphatidyl-choline-lipiodol (CPL) suspension for hepatocellular carcinoma].

Sixty-three patients with unresectable hepatocellular carcinoma (HCC) were treated with cisplatin-phosphatidyl-choline-Lipiodol (CPL) suspension. Partial response (PR) and minor response (MR) were obtained in 3 of 14 cases (21.4%) by one shot therapy, and in 13 of 43 cases (30.2%) by TAE therapy. AFP decreased in 11 of 15 patients (73.3%) by one shot therapy, and in 32 of 33 patients (97%) by TAE therapy. PIVKA II also decreased. The one-year survival rate was 74% in TAE therapy, and 52% in one shot therapy. The two-year survival rate was 53% in TAE therapy, and 28% in one shot therapy. Nausea, vomiting and fever were noted in most cases as adverse effects, but they were slight. The concentration of free-CDDP in the peripheral venous blood was lower and continued longer than that of CDDP on the market. These results suggest that CPL was useful as an anticancer agent for arterial chemotherapy or TAE therapy for unresectable HCC.

Carcinoma, Hepatocellular↗
PubMed1991

Cell shedding from x-irradiated multicellular spheroids of human lung carcinomas.

We studied the effect of radiation on cell shedding from the surface of multicellular spheroids. Spheroids were produced from two human lung cell lines, one adenocarcinoma (LCT1) and the other small cell carcinoma (LCT2), by using a liquid overlay culture technique. The number of cells shed from both kinds of spheroids did not change significantly when they were irradiated. The number of clonogenic cells shed from both kinds of irradiated spheroids decreased sharply as the dose of irradiation increases. There were no significant differences in clonogenic cell shedding per spheroid between LCT1 and LCT2 spheroids. 400 microns spheroids were more radioresistant to inhibition of clonogenic cell shedding than 250 microns spheroids. Shed cells were more radiosensitive than spheroid cells. In these experiments, we did not obtain any results indicating that radiation enhances metastasis.

Adenocarcinoma↗
PubMed1991

[Successful complete repair of interrupted aortic arch and associated with DiGeorge syndrome in neonate].

We report a rare case of interrupted aortic arch and a right aortic arch associated with DiGeorge syndrome, in neonate. Through a median sternotomy bypass was established placing an arterial perfusion cannula both in the ascending aorta, and in the main pulmonary artery. The right and left pulmonary arteries were temporarily occluded, while this pulmonary cannula perfused the lower part of the body. The arch reconstruction was performed during profound hypothermic total circulatory arrest. The right descending aorta had an adequate length and direct anastomosis was carried out without any tension. The VSD was repaired through a right atrial approach. The patient had hypocalcemia and thymic abnormalities which was consistent with the DiGeorge syndrome. He was treated with calcium gluconate and alfacalcidol, but no serious infection due to immunodeficiency was seen after operation. Post operative catheterization revealed no pressure gradient at the site anastomosis of the aortic arch and satisfactory results.

Aorta, Thoracic↗
PubMed1991

[Exercise and dipyridamole-loading in evaluation of ischemic coronary lesion and coronary reserve in children with Kawasaki disease].

In order to compare the clinical effects of exercise-loading and intravenous dipyridamole-loading tests in evaluating ischemic coronary lesion and coronary reserve, we evaluated changes in ECG, 201-Tl scintigraphy, coronary flow and myocardial metabolism in 10 patients with Kawasaki disease (age range: 7-16 years). Although both loading tests affect coronary hemodynamics and myocardial metabolism by different mechanisms, both were equally effective in detecting ischemic coronary lesion and reduced coronary reserve. On the other hand, when considered on the basis of clinical examination methods used, the dipyridamole-loading test was more effective for evaluating clinical symptoms and ECG, while exercise-loading was more effective for evaluating 201Tl scintigraphy and supply-demand balance. These results suggest that, in the evaluation of ischemic coronary lesion, assessment of clinical effects by a combination of several examination methods is required.

Adolescent↗
PubMed1991

[Scintigraphic quantification of myocardial necrosis using "hot spot" imaging agents in acute myocardial infarction].

Both technetium-99m pyrophosphate/thallium-201 dual nuclide SPECT and indium-111 antimyosin antibody/thallium-201 dual nuclide SPECT were performed in identical 11 patients with acute myocardial infarction. Infarct size was calculated by both hot spot imaging agents on dual nuclide SPECT. Antimyosin accurately accumulated in the infarcted area in all 11 patients on SPECT images corresponding with the electrocardiography, but pyrophosphate accumulated at the site of infarct in 10 of 11 patients. The mean volume obtained from pyrophosphate was 32.5 ml and that from antimyosin was 21.9 ml. The relationship between infarct volume calculated by pyrophosphate and that by antimyosin was linear and correlated well (r = 0.98, p less than 0.001). However the volume of infarction determined with pyrophosphate exceeded that with antimyosin SPECT by 1.64 (p less than 0.001). The reason for this difference is not yet known, but may relate to pyrophosphate uptake in border zones that may or may not be irreversibly injured.

Adult↗
PubMed1991

[Establishment of double grafted tumor model in mice and role of "tumor necrosis factor" (TNF)].

A double grafted tumor model (colon 26 and Meth-A) was established in BALB/c mice. The primary colon 26 tumor growth was inhibited by the secondary transplantation of Meth-A tumor cells into the same host, and the prolongation of mean survival time was also observed. To investigate the mechanism of the prolongation of survival, the role of tumor necrosis factor (TNF) was examined. The intraperitoneal inoculation of human TNF-alpha (1 x 10(4) units) for 5 days, as well as the secondary Meth-A tumor cell transplantation, resulted in the prolongation of survival. Moreover, the prolongation of survival disappeared by the inoculation of rabbit anti-TNF-alpha antibodies. These results suggest that TNF-alpha play an important role in the mechanism of a prolongation of survival by the secondary transplantation of the tumor cells.

Animals↗
PubMed1991

[Evaluation of coronary hemodynamics and coronary reserve in children with coronary sequelae of Kawasaki disease].

We measured coronary blood flow by the continuous thermodilution method during coronary sinus catheterization via the femoral vein, and evaluated coronary reserve based on the findings of coronary hemodynamics and myocardial metabolism during atrial pacing. The study subjects consisted of 31 pediatric cases with a history of Kawasaki disease. Among them, 19 had normal coronary angiograms (Group A), 8 had dilated coronary lesions (Group B), and 4 had stenotic coronary lesions (Group C) on selective left coronary angiograms. 1. Coronary blood flow at rest: There were no significant differences between Groups A and B. In Group C, slightly low values were obtained in 2 patients with obstruction or recanalization in the left anterior descending artery. 2. Rate of an increase in coronary blood flow during atrial pacing: It was significantly lower in 5 of 19 patients in Group A, in 2 of 8 in Group B, and in one of 4 in Group C. However, in 2 patients with lower coronary blood flow at rest, the rate of an increase in coronary blood flow during atrial pacing was higher. 3. Following atrial pacing, enhanced anaerobic metabolism was observed in 6 of 17 patients (Group A, 2 of 5; Group B, 2 of 8; Group C, 2 of 4) who showed a poor increase in coronary blood flow during atrial pacing. These results indicate that coronary reserve may decrease even in patients without any coronary sequelae of Kawasaki disease on selective coronary angiograms possibly because of inadequate imaging of the microcirculation, i.e., the problem of the pathologic process at the level of small intramyocardial arterioles. To investigate the coronary sequelae of Kawasaki disease, the evaluation of coronary hemodynamics and myocardial metabolism by coronary sinus catheterization before and after atrial pacing is highly recommended.

Adolescent↗
PubMed1991

[Effects of isosorbide dinitrate on coronary and systemic circulation in children].

The effects of isosorbide dinitrate (ISDN) on the coronary and systemic circulation were evaluated in 8 children with angiographically normal coronary arteries. ISDN, 100 micrograms/kg, was given as a intracoronary injection. The pulmonary artery pressure, pulmonary capillary wedge pressure and left ventricular end diastolic pressure which are related to the pre-load were significantly reduced 1 min after the ISDN injection. The systolic blood pressure was reduced, and heart rate increased. The cardiac output, pressure-rate product and systemic vascular resistance showed no significant change. The systolic work index, however, was significantly reduced. ISDN induced a significant dilatation, ranging from 4.0% to 12.9%, in the diameter of the coronary vessels. There was, however, no change in the coronary blood flow, coronary perfusion pressure and coronary vascular resistance. The grade of the dilatation of the coronary vessels by ISDN in children was lower as compared with that in adult.

Adolescent↗
PubMed1991

[Evaluation of nitroglycerin and prostaglandin E1 administration during cardiac surgery].

Twenty patients, subjected to open heart surgery using standard moderate hypothermic and nonpulsatile extracorporeal circulation (ECC), were divided into two groups. In the control group only nitroglycerin was administered for the control of peripheral arterial blood pressure during ECC. In the PGE1 group, prostaglandin E1 (10 ng/kg/min) and nitroglycerin were used simultaneously. Plasma renin activity (PRA), angiotensin I (A I) and II (A II), aldosterone (Ald), epinephrine (E) and norepinephrine (NE) were increased to equal levels in both groups. PRA, A I, A II, and Ald increased five-fold from the initial value during ECC, while E and NE increased twenty-fold. Total peripheral vascular resistance was high in both groups, but the deviation from the normal level was significantly lower in the PGE1 group. Oxygen consumption during ECC revealed similar patterns of change in both groups. Peripheral arterial blood pressure was more easily controlled at acceptable levels in the PGE1 group. We concluded that the administration of both nitroglycerin and prostaglandin E1 may sustain satisfactory peripheral circulation during ECC.

Adolescent↗
PubMed1991

[Clinical results of free (aorta-coronary) internal thoracic artery grafting].

In the two year period from 1989 to 1990, 22 patients (18 men, 4 women; age range from 40 to 59 years) underwent coronary artery bypass grafting (CABG) using in situ and free internal thoracic arteries (ITAs). 23 of total 38 ITA grafts were free grafts in the aorta-coronary position, mainly to provide sufficient graft length. All of 34 ITA grafts were patent in 20 patients with coronary arteriography about one month after operation. There were no early and late death, and all patients were free from angina after a 9.4 month mean follow-up. Perioperative complications included reoperation for the bleeding in one case and the elevation of left diaphragm in one case, but there was no other major complication such as perioperative myocardial infarction, cerebral infarction or mediastinitis. These results indicated that the free ITA could be applied as well as the in situ ITA in multiple CABG of the Japanese with good patency rate and low operative risk.

Adult↗
PubMed1991

Lung thallium-201 uptake during exercise emission computed tomography.

To test whether the analysis of lung uptake is worth adding to the interpretation of exercise thallium-201 (201TI) emission computed tomography (ECT), a lung/heart ratio of 201TI uptake was measured from an anterior image during ECT in 25 clinically normal (Group 1), 91 angiographically normal (Group 2), and 265 subjects with coronary artery disease (Group 3). The mean +2 s.d. of ratios in Groups 1 and 2 were the same (0.37). In Group 3, 80 subjects (30%) with increased ratios (greater than 0.37) had higher frequencies of prior infarction and multi-vessel disease, more severe left ventricular dysfunction, and 201TI defects than 185 subjects with normal ratios. Subjects with markedly increased ratios (greater than 0.45) had three-vessel disease more frequently than those with slightly or moderately increased ratios (67% versus 14% or 35%). Thus the measurement of lung/heart ratios may provide information regarding the severity of coronary artery disease and should be added to the routine interpretation of exercise ECT.

Aged↗
PubMed1990

Phorbol ester-induced release of endothelium-derived relaxing factor.

The effects of a phorbol ester, 12-deoxyphorbol 13-isobutyrate (DPB), on contraction of isolated vascular smooth muscle of rat aorta were examined. DPB (100 nM-1 microM) induced a concentration-dependent contraction in resting aorta. DPB (3-100 nM) also induced a concentration-dependent relaxation of the norepinephrine-induced contraction. The contractile effect of DPB was potentiated whereas the relaxant effect was inhibited by endothelium removal or by methylene blue, suggesting that lower concentrations of DPB release endothelium-derived relaxing factor to inhibit contraction in rat aorta.

Animals↗
PubMed1990

Neurogenic stress ulceration caused by laparotomy under anesthesia plus restraint. The device of a new rat model.

We report herein, a new method devised of producing neurogenic stress ulceration in rats. An experimental subarachnoid hemorrhage (SAH) was produced in rats by injecting 0.2 ml of arterial blood from other rats into the cisterna magna. Three days later, the rats were laparotomized for 1 hour under ether anesthesia, followed by restraint for 3 hours in wakefulness. The SAH rats were found to develop stress ulcers (UL-I) in the glandular stomach, which were significantly (p less than 0.001) more marked than those in non-SAH rats. Measurements were performed on gastric acid secretion, an important aggressive factor. It was found that the SAH rats undergoing the laparotomy-restraint stress showed a more marked increase in gastric acid secretion and a more marked reduction in MBF, than the non-SAH rats. The effects of bilateral vagotomy, upper abdominal sympathectomy and bilateral adrenalectomy were examined, and it was revealed that the SAH rats were under the condition of hyperreactivity both in the sympathetic and parasympathetic systems and, on this basis, the laparotomy-restraint stress caused the stress gastric ulceration. In this rat model, the laparotomy stress was applied under anesthesia and any exposure to low temperatures which may have interfered with blood circulation was avoided.

Anesthesia, General↗
PubMed1990

Clinical significance of plasminogen activator inhibitor activity in patients with exercise-induced ischemia.

To assess the fibrinolytic system in patients with exercise-induced ischemia and its relation to ischemia and severity of coronary artery disease (CAD), 47 patients with CAD confirmed by results of coronary angiography underwent symptom-limited multistage exercise thallium-201 emission computed tomography. All patients with CAD had exercise-induced ischemia as assessed from thallium-201 images. Pre- and peak exercise blood samples from each patient and preexercise blood samples from control subjects were assayed for several fibrinolytic components and were also assayed for plasma adrenaline. The extent of ischemia was defined as delta visual uptake score (total visual uptake score in delayed images minus total visual uptake score in initial images) and the severity of CAD as the number of diseased vessels. In the basal condition, plasminogen activator inhibitor (PAI) activity was significantly higher in patients with exercise-induced ischemia as compared to control subjects (p less than 0.01), although there were no significant differences in other fibrinolytic variables between the two groups. Moreover, PAI activity in the basal condition displayed a significantly positive correlation with the extent of ischemia (r = 0.47, p less than 0.01). Patients with exercise-induced ischemia were divided into two groups (24 with single-vessel disease and 23 with multivessel disease). There were no significant differences in coronary risk factors, hemodynamics, or plasma adrenaline levels during exercise between single-vessel and multivessel disease except that delta visual uptake score was significantly higher in multivessel disease (p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

Multiple free (aorta-coronary) gastroepiploic artery grafting.

The use of in situ gastroepiploic artery grafts has been reported recently. In the present case, the in situ gastroepiploic artery was too short to graft both the diagonal and the obtuse marginal branches of the coronary arteries in a patient with diffuse coronary artery disease. The free (aorta-coronary) gastroepiploic artery graft was anastomosed to both arteries to form a Y graft.

Anastomosis, Surgical↗
PubMed1990

Exercise-induced silent myocardial ischemia: evaluation by thallium-201 emission computed tomography.

Factors associated with silent myocardial ischemia (SMI) during exercise testing were studied by means of thallium-201 emission computed tomography (ECT) in 471 patients. Coronary angiography was done in 290, of whom 167 were found to have significant coronary artery disease (CAD). Exercise-induced ischemia and its severity were defined with ECT. During exercise 108 (62%) of 173 patients with ischemia and 57 (50%) of 115 with ischemia and angiographically documented CAD had no chest pain. One third of the patients showed an inconsistency between scintigraphic ischemia and ischemia ST depression. Age, sex, prior myocardial infarction, and diabetes mellitus were not related to SMI. Patients with SMI had less severe ischemia despite a higher peak double product compared to those with painful ischemia. Among 91 with prior myocardial infarction and exercise-induced ischemia, 51 with periinfarction ischemia had a higher frequency of SMI than did 14 with ischemia remote from the prior infarct zone despite similarities in the severity of ischemia. In conclusion, factors localized within ischemic myocardium such as less severe ischemia or adjacency to a prior infarct made SMI more prevalent.

Angina Pectoris↗