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H Yasui

Publications and source records attributed to H Yasui.

At least 163 records · Page 9Linked to original sources
PubMed1997

Immunological study of unresponsive state in rat hepatic transplant model. 1. Phenotypic and functional analyses of infiltrating cells.

In order to elucidate the immunological characteristics of rat liver transplantation, graft-infiltrating cells (GIC) isolated from rat hepatic allografts were analyzed phenotypically and functionally. GIC from long-surviving recipients (Brown Norway livers into Lewis hosts) and acutely rejecting recipients (DA livers into Lewis hosts) were compared. The relative proportions of all T cells and activated T cells determined by flow cytometry were significantly higher in acutely rejecting Lewis recipients than in long-surviving recipients on day 6 after grafting. Phenotypic kinesis of GIC on days 6, 14, and 45 after transplantation from long-surviving Lewis hosts was analyzed. Each proportion of all T cells, OX8-positive cells (cytotoxic T and natural killer cells), and OX39-positive cells (IL-2 receptor), was greatest on day 6 and decreased by day 45. Cytotoxic activity of GIC toward donor lymphocytes on day 6 was greater in acutely rejecting versus long-surviving recipients. These results demonstrate that an immunosuppressive mechanism is already present on day 6 posttransplantation, and that infiltration or activation of cytotoxic T cells is inhibited in the long-surviving rat hepatic allografts.

Animals↗
PubMed1997

The effect of low-dose inhalation of nitric oxide in patients with pulmonary fibrosis.

The aim of this study was to determine whether low-dose inhalation of nitric oxide (NO) improves pulmonary haemodynamics and gas exchange in patients with stable idiopathic pulmonary fibrosis (IPF). The investigation included 10 IPF patients breathing spontaneously. Haemodynamic and blood gas parameters were measured under the following conditions: 1) breathing room air; 2) during inhalation of 2 parts per million (ppm) NO with room air; 3) whilst breathing O2 alone (1 L.min-1); and 4) during combined inhalation of 2 ppm NO and O2 (1 L.min-1). During inhalation of 2 ppm NO with room air the mean pulmonary arterial pressure (Ppa 25 +/- 3 vs 30 +/- 4 mmHg) and the pulmonary vascular resistance (PVR 529 +/- 80 vs 699 +/- 110 dyn.s.cm-5) were significantly (p < 0.01) lower than levels measured whilst breathing room air alone. However the arterial oxygen tension (Pa,O2) did not improve. The combined inhalation of NO and O2 produced not only a significant (p < 0.01) decrease of Ppa (23 +/- 2 vs 28 +/- 3 mmHg) but also, a remarkable improvement (p < 0.05) in Pa,O2 (14.2 +/- 1.2 vs 11.7 +/- 1.0 kPa) (107 +/- 9 vs 88 +/- 7 mmHg)) as compared with the values observed during the inhalation of O2 alone. These findings suggest that the combined use of nitric oxide and oxygen might constitute an alternative therapeutic approach for treating idiopathic pulmonary fibrosis patients with pulmonary hypertension. However, further studies must first be carried out to demonstrate the beneficial effect of oxygen therapy on pulmonary haemodynamics and prognosis in patients with idiopathic pulmonary fibrosis and to rule out the potential toxicity of inhaled nitric oxide, particularly when used in combination with oxygen.

Administration, Inhalation↗
PubMed1997

Arterial endothelin-1 level in pulmonary emphysema and interstitial lung disease. Relation with pulmonary hypertension during exercise.

This study was undertaken to assess the arterial plasma levels of endothelin-1 (ET-1) and their relationship with pulmonary haemodynamic and gas exchange variables during exercise in patients with emphysema and interstitial lung disease (ILD). Incremental cycle ergometry was performed in all patients up to maximal capacity. At rest, arterial ET-1 levels were higher in emphysema (1.86 +/- 0.35 pg.mL-1; p < 0.02) and ILD (1.75 +/- 0.25 pg.mL-1; p < 0.03) patients than in controls (1.35 +/- 0.18 pg.mL-1). Emphysema (2.08 +/- 0.26 versus 1.70 +/- 0.40 pg.mL-1) and ILD (1.98 +/- 0.21 versus 1.67 +/- 0.02 pg.mL-1) patients with pulmonary hypertension (PH) presented significantly (p < 0.05) higher arterial ET-1 levels than those without. At rest, arterial ET-1 levels were significantly correlated with mean pulmonary arterial pressure (Ppa) in both ILD (r = 0.8, p = 0.01) and emphysema (r = 0.5, p = 0.03) patients. During exercise, the arterial ET-1 levels were significantly correlated with arterial oxygen (Pa,O2) (r = -0.6, p = 0.04), alveolar-arterial oxygen difference (r = 0.8, p = 0.01), and Ppa (r = 0.6, p = 0.04) in ILD patients, but not in those with emphysema. In brief, the results of this study suggest that arterial endothelin-1 is markedly increased in interstitial lung disease and emphysema patients, and that, it is related to the exercise-induced exacerbation of pulmonary hypertension in patients with interstitial lung disease, but not in those with emphysema.

Aged↗
PubMed1997

Circulating intercellular adhesion molecule-1 in patients with lung cancer.

Recently, abnormal expression of a great variety of adhesion molecules has been reported in malignancy. Of these adhesion molecules, intercellular adhesion molecule-1 (ICAM-1) has been suggested to play an important role in the process of tumor invasion and distant metastasis. The purpose of this investigation was to assess the peripheral blood levels of soluble ICAM-1 and the effect of cytotoxic therapy upon these circulating molecules in a cohort of patients with lung cancer. This study comprised 19 lung cancer patients hospitalized in our institution (males 16 and females 3, mean age 60 years old). Serum concentration of soluble ICAM-1 was measured using a commercially available enzyme immunoassay test kit. These measurements were done before the initiation of any therapy and on day 5 of chemotherapy. Samples taken from healthy volunteers were available for comparison. Soluble ICAM-1 serum concentration was significantly higher (p < 0.0001) in the cancer patients as compared to that of the control group. Serum levels of ICAM-1 were more significantly (p < 0.02) elevated in patients with advanced stages of disease. This study suggests the presence of an increased expression of circulating adhesion molecules in lung cancer. The concentration of this adhesion molecule was correlated with the clinical stage of the malignant disease, but did not change significantly after multidrug cytotoxic therapy.

Adenocarcinoma↗
PubMed1997

[Low dose inhalation of nitric oxide in chronic obstructive pulmonary diseases].

We studied the effect of inhalation of various concentrations of nitric oxide (NO)(2 ppm, 5 ppm, and 10 ppm) on the pulmonary circulation and on arterial oxygenation in 11 patients with stable chronic obstructive pulmonary disease. Inhalation of 2 ppm of NO resulted in values of mean pulmonary arterial pressure significantly lower than those measured while breathing room air only (24.1 +/- 1.7 vs 20.7 +/- 1.7 mmHg, p < 0.00001). The decrease in pulmonary artery pressure associated with inhalation of 2 ppm NO was only slightly less than the decrease associated with 10 ppm; the difference between the two was not considered to be clinically relevant. The pulmonary vascular resistance was significantly lower during inhalation of 2 ppm NO than during inhalation of room air only (495 +/- 40 vs 382 +/- 34 dyne.sec/cm5, p < 0.00001); the effects of inhaling 2 ppm and 10 ppm did not differ significantly. the partial pressure of oxygen in arterial blood was significantly lower after inhalation of 2 ppm NO than of baseline (61.1 +/- 2.3 vs 57.6 +/- 2.2 mmHg, p < 0.01). These results show that inhalation of NO worsens arterial oxygenation in patients with chronic obstructive pulmonary disease.

Administration, Inhalation↗
PubMed1997

[Serotypes and drug susceptibility of Pseudomonas aeruginosa isolated from clinical specimens].

Between January, 1982 and December, 1994, 236 Pseudomonas aeruginosa strains were isolated from clinical specimens at our division, and were tested for serotypes and drug-susceptibilities to 15 antibiotics. Serotype G strains were isolated at the highest frequency (32.6%), and followed by strains of serotype B (15.7%), A (11.9%), E (9.3%), I (7.2%), F and M (5.5%), non-typable (5.1%), D (3.4%), H (2.1%), C and K (0.8%). We examined the changes of isolation frequencies of different serotypes annually. Isolation frequencies of serotypes E and F showed tendency to decrease, whereas serotype I has been isolated increasingly year by year. MIC90's of the 15 antibiotics were as follows, tosufloxacin: 0.78 microgram/ml, biapenem (BIPM) and ofloxacin (OFLX): 3.13 micrograms/ml, imipenem (IPM), ceftazidime, cefozopran, cefsulodin and gentamicin: 6.25 micrograms/ml, aztreonam and amikacin: 12.5 micrograms/ml, piperacillin, cefoperazone and minocycline (MINO): 25 micrograms/ml, fosfomycin: > 100 micrograms/ml and chloramphenicol: > 200 micrograms/ml. MIC90'S of IPM, BIPM, MINO and OFLX increased 4-fold from stage I (1982-1987) through stage III (1992-1994) and the isolation frequency of drug-resistant strains increased year by year. In other words, antibiotic resistant strains appeared increasing with time. No relationship between serotypes and drug-resistance were observed.

Anti-Bacterial Agents↗
PubMed1997

The effect of calcium gluconate and other calcium supplements as a dietary calcium source on magnesium absorption in rats.

The effects of commercially available calcium supplements (calcium carbonate, calcium gluconate, oyster shell preparation and bovine bone preparation) and gluconic acid on the absorption of calcium and magnesium were evaluated for 30 days in male Wistar rats. There were no differences in the apparent absorption ratio of calcium among rats fed each calcium supplement; however, the rats fed the calcium gluconate diet had a higher apparent absorption ratio of magnesium than the rats fed the other calcium supplements. Dietary gluconic acid also more markedly stimulated magnesium absorption than the calcium carbonate diet, and the bone (femur and tibia) magnesium contents of rats fed the gluconic acid diet were significantly higher than those of the rats fed the calcium carbonate diet. Furthermore, the weight of cecal tissue and the concentrations of acetic acid and butyric acid in cecal digesta of rats fed the calcium gluconate diet or the gluconic acid diet were significantly increased. We speculate that the stimulation of magnesium absorption in rats fed the calcium gluconate diet is a result of the gluconic acid component and the effect of gluconic acid on magnesium absorption probably results from cecal hypertrophy, magnesium solubility in the large intestine and the effects of volatile fatty acids on magnesium absorption.

Absorption↗
PubMed1997

[A case of amyloidosis of the tracheobronchial tree and inferior nasal concha].

A 50-year-old man resented at a local medical clinic with nasal obstruction. He was treated but did not improve. He then consulted our institution. Chest X-ray disclosed infiltrative shadows in the basal region of the left lung. A computed tomography scan of the lung showed marked thickening of the airway walls extending from the trachea to both bronchial trees and obstructive changes in the left lower lobe of the lung. On bronchoscopic examination the bronchial mucosa was reddened and edematous with a pinhole bronchial obstruction in one region. Congo red staining of biopsy samples taken from the bronchial mucosa showed deposition of an amorphous substance. Tracheobronchial amyloidosis was diagnosed. The amyloid material was resistant to potassium permanganate and tested positive for lambda-chain of L immunoglobulin. Otorrhinolaryngological examination disclosed a tumor in the inferior nasal concha as the cause of his nasal obstruction. The nasal tumor was resected and AL lambda-type amyloidosis was diagnosed pathologically. Tracheobronchial and inferior nasal concha amyloidosis is an extremely rare pathological condition. The patient was followed for one year and remain asymptomatic without treatment.

Amyloidosis↗
PubMed1996

Lazaroid (U74500A) prevents vascular and myocardial dysfunction after 24-hour heart preservation. A study based on cross-circulated blood-perfused rabbit hearts.

BACKGROUND: The prevention of ventricular and vascular dysfunction has been recognized as an important factor in heart preservation. Because lipid peroxidation may cause cell membrane injury after ischemia and reperfusion, we hypothesized that the administration of a lipid peroxidation inhibitor lazaroid (U74500A) would result in an improvement of functional recovery after the 24-hour preservation period. METHODS AND RESULTS: An isolated rabbit heart preparation perfused with support rabbit blood was used. Before preservation, 4 mg/kg of either lazaroid or solvent was given to donor rabbits. The hearts were preserved with University of Wisconsin solution for 24 hours at 0 degree C. The working model preparation (n = 7 in each group) showed a better cardiac output (74.6 +/- 25.7 versus 192.7 +/- 19.6 mL/min, P < .0001) and a lower lipid peroxide level (2.1 +/- 1.3 versus 0.6 +/- 0.3 nmol/mL. P < .05) of the coronary effluent in the heart treated with lazaroid. With a Langendorff preparation (n = 7 in each group), we evaluated the vascular dilatory function. The endothelial function assessed by the percentage increase of coronary flow in response to acetylcholine in the solvent group was significantly lower than that of the lazaroid group (69 +/- 24% versus 140 +/- 67%, P < .05), whereas no significant difference was observed between the groups regarding endothelium-independent vasodilatation as assessed by the responses to nitroglycerin and nitroprusside. CONCLUSIONS: These results demonstrated an improved ventricular and endothelial function in the rabbit pretreated with lazaroid before preservation accompanied by a reduction of lipid peroxidation, indicating the potential benefits for long-term heart preservation.

Animals↗
PubMed1996

The effect of lazaroid (U74500A), a novel inhibitor of lipid peroxidation, on 24-hour heart preservation. A study based on a working model using cross-circulated blood-perfused rabbit hearts.

Lazaroid, an inhibitor of iron-mediated lipid peroxidation, has been shown to reduce free radical-mediated injury after ischemia and reperfusion. We thus examined the efficacy of pretreatment with lazaroid (U74500A) in enhancing functional recovery after 24-hr heart preservation. An isolated rabbit heart model perfused with the blood from a support rabbit was used. Before preservation, either U74500A (4 mg/kg, group L; n = 6) or solvent (group S; n = 7) was given to the donor rabbit. After 24-hr preservation with UW solution at 0 degrees C, all hearts were perfused with cross-circulated blood for 60 min with the Langendorff mode followed by 40 min of the working mode. In group S, ventricular fibrillation (Vf) after reperfusion was observed in all hearts, whereas no Vf was observed in the U74500A-pretreated group. In group L, the serum creatine phosphokinase; its isozyme, troponin-T; and serum lipid peroxide levels after 10 min of reperfusion were all significantly (P < 0.05) lower than those in group S. The Frank-Starling curve (indicating the left atrial pressure-aortic flow relationship) showed a significant left and upward shift in group L compared with that in group S (P < 0.0001). The heart pretreated with U74500A showed less ischemia-reperfusion injury, better ventricular function, and a lower lipid peroxide level. We thus conclude that the inhibition of lipid peroxidation with lazaroid appears to offer some potential benefits for long-term heart preservation.

Animals↗
PubMed1996

Influence of genetic and maternal diabetes in the pathogenesis of visceroatrial heterotaxy in mice.

The NOD mouse is known as a spontaneous model of insulin-dependent diabetes mellitus. Fetuses in this strain present anomalies of the viscera, and the incidence increases in fetuses from dams with clinically manifested diabetes. To examine the role of maternal diabetes and the genetical influence in inducing heterotaxy, NOD dams were mated with males of the ICR strain (the original strain of the NOD) and with C57BL/6J sires (not genetically related to the NOD). The frequency of visceroatrial heterotaxy in fetuses from diabetic dams varied with the fetal genotype, being 65% (33/51) in NODxNOD (dam X sire, respectively), 24% (12/50) in NODxICR, and 7% (4/57) in NODxC57BL/6J. The cases with heterotaxy showed a tendency toward right isomerism of the viscera and had severe cardiac defects, such as endocardial cushion defect and double-outlet right ventricle or transposition of the great arteries. The fetal body weight from diabetic dams in each mating was lower than that from non-diabetic dams (P < 0.05), suggesting that maternal diabetes, rather than abnormal situs, is the main determinant for decreased fetal growth. These findings demonstrate that the liability to heterotaxy induced by maternal diabetes is influenced by the fetal genotype.

Abnormalities, Multiple↗
PubMed1996

Postoperative cardiac rhythms with superior-septal approach and lateral approach to the mitral valve.

BACKGROUND: The superior-septal approach provides an excellent view of the mitral valve and therefore has received considerable interest. However, the safety of this approach is controversial because it requires division of the sinus node artery in most cases. METHODS: Postoperative cardiac rhythms were analyzed in 152 consecutive patients who underwent mitral valve procedures between January 1992 and February 1995 with a conventional right lateral left atriotomy (group 1, n = 69) or the superior-septal approach (group 2, n = 83). Follow-up ranged from 2 to 38 months, and the mean follow-up was 16.1 months in group 1 and 13.8 months in group 2. RESULTS: The mortality rate was similar in the two groups (1.4% in group 1 and 1.2% in group 2), and the causes of death were not related to the left atriotomy. At discharge, 96% of the patients in group 1 who were in sinus rhythm preoperatively and 78% of those in group 2 remained in sinus rhythm. At the last follow-up, 88% of these patients in group 1 and 83% in group 2 remained in sinus rhythm. Among the patients in atrial fibrillation or junctional rhythm before operation, 12% in group 1 and 11% in group 2 had regained sinus rhythm at the last follow-up. There were no significant differences in these values. CONCLUSIONS: Although the incidence of dysrhythmias was higher with the superior-septal approach in the early postoperative period, this approach provides an excellent operative view of the mitral valve and similar results in terms of late postoperative cardiac rhythms as the right lateral left atriotomy.

Arrhythmias, Cardiac↗
PubMed1996

Selective cerebral perfusion technique during aortic arch repair in neonates.

We describe selective cerebral perfusion techniques for repair of the aortic arch in neonates. These techniques may help protect the brain from ischemic injury caused by a cessation of cerebral perfusion for aortic arch reconstruction in patients with hypoplastic left heart syndrome or interrupted aortic arch.

Aorta, Thoracic↗
PubMed1996

Effects of hypothermia during cardiopulmonary bypass and circulatory arrest on sympathetic nerve activity in rabbits.

OBJECTIVES: Little is known about the effect of hypothermia on neural regulation. We investigated the effects of hypothermia during cardiopulmonary bypass (CPB) on control of renal (RSNA) and lumbar sympathetic nerve activity (LSNA), and plasma catecholamine levels. METHODS: We directly measured RSNA (n = 14) and LSNA (n = 6) during CPB in anesthetized rabbits. CPB was performed via cannulae in the aortic root for arterial perfusion and the right atrium for venous drainage. Systemic hypothermia was induced by core cooling. RSNA and LSNA were recorded at the nasopharyngeal temperature of 37, 30, 24, and 18 degrees C and after rewarming up to 37 degrees C while keeping mean arterial pressure at 70 mmHg by altering perfusion flow. Other variables such as blood gases or electrolytes were kept constant. RESULTS: RSNA at the temperature of 30, 24, and 18 degrees C significantly decreased by 91, 97, and 95% from control (37 degrees C), respectively. LSNA decreased by 18, 57, and 89% from control as well. The decreases in RSNA at 30 and 24 degrees C were greater than those in LSNA (P < 0.05). At 18 degrees C both RSNA and LSNA nearly disappeared. Circulatory arrest for 20 min during hypothermia at 18 degrees C caused no increase in RSNA while it increased LSNA. Plasma catecholamine levels at 18 degrees C were not different from those at 37 degrees C. Rewarming to 37 degrees C increased RSNA and LSNA by 321 and 92% from control (37 degrees C before cooling), respectively (P < 0.01). CONCLUSIONS: Hypothermia progressively decreased and rewarming markedly increased sympathetic nerve activity, but the effects of hypothermia on RSNA and LSNA were not uniform.

Animals↗
PubMed1996

The relationship between functional class, pulmonary artery pressure and size in left atrial myxoma.

To examine the correlation between the size of left atrial myxoma, the degree of pulmonary hypertension and the patient's New York Heart Association (NYHA) functional class, the records of 29 surgically treated patients with left atrial myxoma were reviewed. Of 29 patients, 23 were catheterized before surgery. As the preoperative NYHA functional class advanced, the preoperative mean pulmonary artery pressure (mmHg) was seen to increase. Moreover, the weight of the excised myxoma also correlated well with the preoperative pulmonary artery pressure value. In five patients inserted with a Swan-Ganz catheter, the mean pulmonary artery pressure decreased immediately after tumour excision. Postoperatively, the average NYHA class of the 29 patients significantly improved. These results confirmed the positive correlation between the size of the tumour, the pulmonary artery pressure, and NYHA class in patients with left atrial myxoma.

Adult↗
PubMed1996

Subaortic stenosis caused by anomalous papillary muscle of the mitral valve.

We report on a rare case of subaortic stenosis caused by an anomalous posteromedial papillary muscle inserting directly into the anterior mitral leaflet, which had muscular extension to the subaortic region. Resection of the muscular extension alone was ineffective. A second operation including entire resection of the anomalous papillary muscle and mitral valve replacement resulted in successful relief of the obstruction. Microscopic findings of the resected tissue were compatible with those of hypertrophic cardiomyopathy.

Aortic Valve Stenosis↗
PubMed1996

Inhibition of lipid peroxidation with the lazaroid U74500A attenuates ischemia-reperfusion injury in a canine orthotopic heart transplantation model.

BACKGROUND: The lazaroid U74500A is a 21-aminosteroid that inhibits lipid peroxidation and attenuates ischemia-reperfusion injury. We examined the effect of U74500A on heart preservation with the use of a clinically relevant canine orthotopic heart transplantation model. METHODS AND RESULTS: Six donor dogs (group L) were pretreated intravenously with U74500A (10 mg/kg), and the dogs without pretreatment served as a control (group C, n = 6). The donor heart was preserved in cold University of Wisconsin solution for 24 hours. The heart was then transplanted orthotopically. Myocardial biopsy was performed to measure the adenosine triphosphate level at the end of ischemia. Before reperfusion, recipients in group L received another dose of U74500A (10 mg/kg) intravenously. After 3 hours of reperfusion, left ventricular function was evaluated by left ventricular pressure-volume relations with the use of a Millar catheter and conductance catheter, thereby deriving the slope of the end-systolic pressure-volume relation, the slope of the stroke work-- end-diastolic volume relation, and the slope of the maximum dP/dt--end-diastolic volume relation. At the same time, serum creatine kinase MB isoenzyme and lipid peroxide levels were measured. The slopes of the end-systolic pressure-volume relation, the stroke work--end-diastolic volume relation, and the maximum dP/dt--end-diastolic volume relation for group L were significantly higher than those for group C. The adenosine triphosphate levels for group L were significantly higher than those for group C. Serum creatine kinase MB isoenzyme and lipid peroxide levels for group L were significantly lower than those for group C. CONCLUSIONS: Inhibition of lipid peroxidation by the administration of U74500A was effective for 24-hour canine cardiac preservation. These results indicate that U74500A is a promising agent for heart allograft preservation.

Adenosine Triphosphate↗