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Biomedical subjects

K Ueyama

Publications and source records attributed to K Ueyama.

90 records · Page 5Linked to original sources
PubMed1993

Physiologic characteristics of coronary artery bypass grafts.

To investigate the hemodynamic characteristics of arterial grafts for coronary artery bypass grafting, we measured phasic pressure and flow patterns in three types of grafts in a canine model (n = 18). A graft from the ascending aorta (AAG), a graft from the descending aorta at the first lumbar level (DAG), analogous to a right gastroepiploic artery, and an internal thoracic artery (ITA) were anastomosed to each other. The composite graft was anastomosed to the left anterior descending coronary artery, and then the left anterior descending coronary artery was ligated. Before grafting, the AAG showed high sustained diastolic pressure, but the ITA and DAG showed rapid fall of diastolic pressures. Mean diastolic pressures were 83 +/- 2, 72 +/- 3, and 57 +/- 2 mm Hg in the AAG, ITA, and DAG (p < 0.05). Free flow in the AAG was markedly greater than in the ITA or the DAG. After grafting to the left anterior descending coronary artery, no changes were observed in diastolic pressures compared with the pregrafting values. Total blood flows were 72 +/- 6, 80 +/- 7, 57 +/- 7, and 44 +/- 6 mL/min in the left anterior descending coronary artery, AAG, ITA, and DAG, respectively. There were no differences in systolic graft flow between the three types of grafts. Diastolic blood flow in the ITA (29 +/- 4 mL/min) and DAG (18 +/- 3 mL/min) was smaller than in the AAG (48 +/- 4 mL/min) (p < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1993

Intracranial self-stimulation and locomotor traces as indicators for evaluating the homopantothenic acid.

Our paper compares the effect of homopantothenic acid (HOPA) and haloperidol (HAL), i.e., representative neuroleptics, on intracranial self-stimulation (ICSS) and locomotor activity. These experiments showed that HOPA inhibited abnormal hyperactivity induced by methamphetamine (MAP) but did not inhibit ICSS which is considered with respect to physiological motivations. On the other hand, haloperidol (HAL) markedly inhibited both ICSS and abnormal hyperactivity induced by MAP. We propose that combined ICSS and locomotor traces can be chosen as indicators for evaluation and developing the new neuroleptics.

Animals↗
PubMed1993

Brain atrophy and intellectual impairment in tardive dyskinesia.

Fourteen chronic schizophrenic patients with tardive dyskinesia (TD) and 13 without TD were given psychological tests and CT scans. The low density rate (LDR), i.e., the ratio of the X-ray absorption (corresponding nearly to that of cerebrospinal fluid) of a brain lesion to the X-ray absorption of the whole brain, was used as an index of brain atrophy (HN-method). The LDR of the left hemisphere of the TD patients was significantly higher than that of non-TD patients in the basal nucleus and lateral ventricle, and the LDR of the right hemisphere for the TD patients was significantly higher than that of non-TD patients in the basal nucleus. The Hasegawa Dementia Rating Scale (HDRS) and Bender-Gestalt Test (BGT) for the TD patients were significantly lower than those for the non-TD patients. Our study revealed that brain atrophy was greater in TD than in non-TD patients and tended to be more pronounced in the left hemisphere, and that the degree of intellectual impairment was greater in the TD patients than in the non-TD group. The results suggest that schizophrenic brains with TD tend to be more easily damaged than those without TD, that this tendency predominates on the left side, and that intellectual impairment in TD is related to brain atrophy.

Adult↗
PubMed1993

[Effect of aprotinin on blood loss reduction after extracorporeal circulation].

High-dose aprotinin has been reported to reduce blood loss after extracorporeal circulation (ECC). However, the hemostatic mechanism of aprotinin remains unknown. We administered aprotinin to 25 patients during coronary artery bypass surgery and examined the blood loss in comparison with that in a control group of 25 patients. On the basis of an experimental study on the effects of aprotinin, 30,000 KIU/kg of aprotinin was infused as the initial ECC dose and 7,500 KIU/kg/h was continuously administered as the maintenance dose from the beginning to the end of ECC. Aprotinin was not used before ECC. Serial blood samples were collected during and after the operation in both groups to examine various coagulation and fibrinolysis system parameters. Blood loss during and 6 hours after the operation and the total blood requirement were significantly lower in the aprotinin group than in the control. There was no difference between the two groups in terms of hemoglobin, platelet count, ACT, and thrombin-antithrombin III complex level. The aprotinin group showed a significantly higher level of alpha 2 (total) plasmin inhibitor and a significantly lower level of plasmin-alpha 2 plasmin inhibitor complex and D-dimer during ECC. These findings indicated that although the coagulation system function was accelerated during ECC, the fibrinolysis function system was suppressed by the administration of aprotinin, which resulted in a reduction of blood loss.

Adult↗
PubMed1993

[A case of left ventricular aneurysm associated with acromegaly].

We performed a left ventricular aneurysmectomy for a left ventricular aneurysm associated with acromegaly in a 62-year-old man. Bromocriptine mesilate was administered to suppress high growth hormone (GH) levels, and there were no complications during or after the operation. The majority of patients with acromegaly die of cardiovascular diseases such as cardiomegaly, hypertension, arteriosclerosis of the coronary arteries, congestive heart failure, valvular disease, and arrhythmia. Ventricular aneurysm is a rare complication of acromegaly. In order to safely operate, it is important to control serum GH levels and pay special attention to the well-known complications of acromegaly such as diabetes mellitus and hypertension.

Acromegaly↗
PubMed1993

[Strategy for cerebral protection during aortic arch replacement].

We analyzed cerebral protection of twenty-five patients, 11 of whom underwent ascending-arch aortic replacement and 14 underwent aortic arch replacement, supported with cardiopulmonary bypass. Twenty of patients underwent selective cerebral perfusion (SCP) with moderate hypothermic circulatory support; 12 of single SCP, 8 of double SCPs. Major arch branch reconstruction were performed with 11 patients; 3 of triple branches, 2 of double branches and 6 of single branch reconstruction. Cerebral impairment was found in 7 patients (25%) with SCP; 3 of them died of low output syndrome and major bleeding during perioperative period. Four of 17 patients, who survived more than one month, showed cerebral infarction in 2 patients and temporary neurological deficit in 2 patients. Our strategies for cerebral protection are (1) careful cerebral four vessels study, (2) SCP with perfusion pressure more than 40 mmHg and flow rate of 7-10 ml/kg/min under moderate hypothermia, (3) bilaterally double branches perfusion minimally for arch replacement, (4) intensive cerebral monitoring from multiple aspect, (5) pharmacological support with barbiturate or aprotinin, (6) gentle maneuver and reliable major branch cannulation to prevent debris embolism.

Aortic Dissection↗
PubMed1992

[Coarctation of aorta with right aortic arch and anomalous left subclavian artery].

The occurrence of coarctation in patients with right aortic arch is extremely rare. We have encountered a 21-year-old man with anomalous left subclavian artery. He was diagnosed when he was 13. On angiography he exhibited a right aortic arch. The left common carotid artery, right common carotid artery and the right subclavian artery diverged from the proximal side of the coarctation. The left subclavian artery diverged from the distal side. The right brachial arterial pressures measured 158-72 mmHg, while the left brachial arterial pressures measured 98-80 mmHg. Clinical studies revealed no vascular ring and no other anomalies were found in this patient. An attempt at treatment was made with extra anatomical bypass grafting from the ascending aorta to the descending aorta. No pressure difference due to coarctation remained after operation.

Adult↗
PubMed1992

[Physiological characteristics of arterial graft for coronary artery bypass surgery].

Arterial grafts have been used widely for coronary artery bypass grafting (CABG) because of their excellent long patency. However, some clinical reports suggest that blood flow in arterial grafts may not be adequate compared with aorto-coronary bypass grafting. Pressure in arterial grafts was measured in patients undergoing CABG. The pressure tracing in the ascending aorta (AA) was maintained during diastole. The systolic pressure wave in ITA and GEA was narrow, while the diastolic pressures fell rapidly: the diastolic pressure in GEA was lower than in ITA. The area under the pressure wave was measured in diastole and in systole. Although there was no significant difference in systolic areas, the diastolic area were lower in ITA than in AA, and lower in GEA than in AA and in ITA. These results clarified that arterial grafts which belong to the systolic-dominant systemic circulation have disadvantages over aorto-coronary bypass grafts, in terms of physiological suitabilities to the diastolic-dominant coronary circulation.

Adult↗
PubMed1992

[Diabetes mellitus and coronary artery bypass surgery].

To determine the influence of diabetes mellitus on the results of coronary artery bypass surgery, a review of 163 diabetic patients operated on during 8 years, of whom 146 were receiving no drugs or receiving oral hypoglycemic agents, and 17 were receiving insulin. They were compared with 337 nondiabetic patients operated on over the same period. Higher incidences of hypertension and cerebrovascular disease for the diabetic group were found. The extent of coronary artery disease as judged angiographically was significantly greater in the diabetic group than in the nondiabetic group. Perioperative mortality was similar in the two groups. The incidence of perioperative myocardial infarction, sternotomy complication, neurological complication, and renal insufficiency was equal in the two groups. Early graft patency was comparable in the two groups. Overall 8-year actuarial angina free ratios were 88.5% for the diabetic group, 93.2% for the nondiabetic group. Overall 8-year survival rates were 95.6% for the diabetic group, 98.6% for the nondiabetic group. Results indicate that diabetic patients have quantitatively more coronary artery disease than the non-diabetic patients but have no higher perioperative morbidity and mortality than nondiabetic patients. Long-term results revealed a lower angina free rate in diabetic patients than in nondiabetic patients.

Coronary Artery Bypass↗
PubMed1992

[Coronary artery bypass surgery in patients with familial hypercholesterolemia].

Coronary artery bypass grafting (CABG) was performed in 48 patients with heterozygous familial hypercholesterolemia (FH). Seventy-nine percent of these patients had three-vessel disease or left main trunk disease. The internal thoracic artery was used for grafting in 26 patients and the right gastroepiploic artery was used in 4 patients. Although no patient died during surgery, one died subsequently from graft-versus-host disease. Graft patency at one month after CABG was 95% in vein grafts, 100% in arterial grafts, and 97% overall. Histological study revealed that arterial grafts in patients with FH had similar structures to those in non-FH patients, without evidence of atherosclerosis. All patients were prescribed anti-cholesterol drugs to control serum cholesterol levels, and 4 patients underwent LDL-apheresis because of poor control. Survival rate at 11 years after CABG was 83% without cardiac death. Cardiac event-free rate in 47 surviving patients was 53% at 10 years after CABG in vein bypass group, 93% at 5 years in the arterial graft group, and 58% at 10 years overall. Results of CABG were as good in FH as in non-FH patients, using arterial grafts and anticholesterol therapy.

Adult↗
PubMed1991

[Effect of surgery for combined abdominal aortic and internal iliac artery aneurysm on postoperative intestinal ischemia and sexual dysfunction].

The effect of surgery for combined abdominal aortic aneurysm (AAA) and internal iliac artery aneurysm (IIAA) on postoperative intestinal ischemia and sexual dysfunction was studied. Nineteen men and three women, aged 51 to 79 years, were included in this study. The IIAA was unilateral in 13 cases and bilateral in 9. The maximum diameter of the IIAAs ranged from 3.0 to 7.5 cm. Seven cases underwent emergent surgery for aneurysmal rupture. A bifurcated graft was implanted in all cases. Among cases with unilateral IIAA, aneurysmectomy and IIA reconstruction was performed in 2 cases, and ligation of the IIA was performed in the remaining 11. Among cases with bilateral IIAAs, IIA reconstruction was performed on one side and IIA ligation on the another side in 1 case. Bilateral ligation was performed in 4 and exclusion of the AAA and both IIAAs were performed in 4. The inferior mesenteric artery was reconstructed in 10 cases. The average postoperative follow-up period was 6.2 years. Postoperatively 2 cases experienced bowel necrosis and 4 had diarrhea and/or mucous stool. An erectile disturbance occurred postoperatively in 33.3% of cases which had undergone unilateral and 50% of cases which had undergone bilateral IIA ligation.

Adult↗
PubMed1990

Three cases of chronic subdural hematoma with depressive state.

The authors described 3 cases of chronic subdural hematoma (CSDH) with a depressive state. There were no abnormal findings from general and neurological examinations. Computed tomographic (CT) brain scans revealed sickle-shaped low density areas in the bilateral frontal lobes. Two of the 3 cases had not had episodes of head contusion, and it was not until the CT brain scanning that they were found to have CSDH. Evacuation of the hematomas was not considered suitable and the depressive state of these 2 cases was improved by antidepressants. The remaining case seemed to have become depressive because of failure in business. After the head contusion, his depressive state gradually became more severe. A neurosurgical operation was carried out to evacuate the hematoma. CSDH seemed to aggravate his depressive state. These 3 cases show that CSDH located in the bilateral frontal lobes may cause and/or influence affective disorder.

Aged↗
PubMed1981

Role of inducer exclusion in preferential utilization of glucose over melibiose in diauxic growth of Escherichia coli.

The role of inducer exclusion in diauxic growth of Escherichia coli on glucose and melibiose was investigated. The amounts of glucose and melibiose in the culture medium were determined during the diauxie. Glucose was consumed during the first growth cycle of the diauxie, and melibiose was consumed during the second cycle. The addition of adenosine 3',5'-cyclic monophosphate to the culture medium released both transient and catabolite repressions on the melibiose operon by glucose. Biphasic growth without a transient lag phase was observed in the presence of adenosine 3',5'-cyclic monophosphate. Preferential utilization of glucose over melibiose was observed even under such conditions. Thus, it is clear that inducer exclusion alone is sufficient to ensure the preferential utilization of glucose over melibiose. Similar results were obtained from a glucose-lactose diauxie. Inducer exclusion itself was not affected by adenosine 3',5'-cyclic monophosphate.

Biological Transport↗
PubMedDate not supplied

PMEA coating of pump circuit and oxygenator may attenuate the early systemic inflammatory response in cardiopulmonary bypass surgery.

We investigated the effects of coating a cardiopulmonary bypass (CPB) circuit and oxygenator with poly-2-methoxy-ethyl acrylate (PMEA) on the systemic inflammatory response during and after CPB. Thirty patients undergoing elective cardiac surgery were randomized into three groups (each group n = 10): noncoated (group N), heparin coated (group H), and PMEA coated circuit and oxygenator (group X). Bradykinin (BK), complement 3 activation (C3a) and interleukin-6 (IL-6) levels were measured as early phase indicators of inflammatory response, as were maximum C reactive proteins (CRP) and white blood cell (WBC) levels. The alveolar-arterial oxygen gradient (A-a DO2) was measured as a parameter of respiratory function. IL-6 levels after CPB were significantly higher in group N than in groups H and X (p < 0.05). Serum BK and C3a levels showed similar patterns in all groups. A-a DO2 was lower at the end of and 3 hours after CPB in groups H and X than in group N (p < 0.05). Maximum CRP levels were lower in group X than in groups N (p < 0.05). This prospective study suggests that PMEA coated CPB may improve respiratory function and decrease systemic inflammatory response after cardiac surgery, possibly because this circuit is as biocompatible as heparin coated CPB circuit.

Acrylates↗
PubMedDate not supplied

A dual approach to self-stimulation and locomotor trace affected by chronic methamphetamine treatment for an animal model of schizophrenia.

The effect of long-term methamphetamine (MAP) treatment on intracranial self-stimulation of the lateral hypotholamus and locomotor traces was assessed. An attempt was made to provide a useful animal model for understanding anhedonia, stereotypy, and reoccurrence of liability, which are analogous to symptoms of schizophrenia. The frequency of intracranial self-stimulation (ICSS) as used as a measure of the animals' "hedonic-anhedonic" state. Following long-term MAP treatment (3 mg/kg), rats gradually showed stereotyped behavior, and became inactive and unresponsive to ICSS. These behavioral changes and decreased ICSS lasted several weeks after cessation of chronic MAP treatment and seemed to suggest post-MAP chronic psychosis and (or) anhedonia, two of the negative symptoms of schizophrenia. The traces of rat behavior affected by chronic MAP treatment were classified into three types, peripheral, mixed, and fixed, occurring in a dose-dependent manner. Reverse tolerance, similar to the reoccurrence of schizophrenic symptoms, was observed as a fixed stereotypy associated with loss of ICSS. These abnormal phenomena were suppressed by pretreatment with haloperidol. In the present study, the combination of ICSS and locomotor trace affected by chronic MAP treatment was proposed as an animal model of schizophrenia and as a useful technique for gauging the effect of neuroleptics.

Animals↗