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Biomedical subjects

H Yasui

Publications and source records attributed to H Yasui.

At least 127 records · Page 7Linked to original sources
PubMed1998

Cardioprotective effect of succinate against ischemia/reperfusion injury.

We investigated the protective effects of succinate, which is a respiratory substrate and a potential antioxidant, on myocardial ischemia/reperfusion injury with the whole heart. Isolated rat hearts were loaded with 25-min normothermic global ischemia followed by 30-min reperfusion in a working heart model. Succinate administered either before reperfusion or added to the cardioplegic solution improved the postischemic cardiac function significantly. The hearts arrested with succinate-supplemented cardioplegic solution replenished high-energy phosphates and maintained the total adenine nucleotides during the reperfusion period, whereas those arrested with succinate-nonsupplemented cardioplegic solution replenished the high-energy phosphates less, and also lost total adenine nucleotides during that period. We thus conclude that succinate administered before reperfusion may decrease the degree of mitochondrial damage during reperfusion and thereby reduce the amount of myocardial ischemia/reperfusion injury.

Animals↗
PubMed1998

Prostaglandin E1 from the tip of an intraaortic balloon catheter for lower limb ischemia.

A method to treat lower limb ischemia associated with the insertion of an intraaortic balloon catheter is herein reported. A low dose of prostaglandin E1 was administered into the descending aorta continuously from the tip of the intraaortic balloon catheter. Immediately after the administration of prostaglandin E1 in patients whose lower limbs were ischemic due to obstruction with the catheter, the peripheral circulation of the ischemic limbs recovered with minimal changes in the systemic arterial blood pressure. This method is simple and noninvasive and was found to induce a satisfactory effect.

Alprostadil↗
PubMed1998

Clinical results of the staged Fontan procedure in high-risk patients.

BACKGROUND: For high-risk Fontan candidates, the introduction of a bidirectional Glenn shunt before total cavopulmonary connection (a two-staged strategy) may extend the indications for the Fontan procedure. The clinical results of the two-staged and one-staged Fontan procedure were thus reviewed and compared. METHODS: Between November 1991 and July 1996, the two-staged strategy was performed in 40 high-risk Fontan candidates with a mean interval of 17.2 months after introducing the bidirectional Glenn shunt (staged group). We considered a young age (<2 years), high mean pulmonary arterial pressure (> or =20 mm Hg), high pulmonary vascular resistance (> or =3 Wood units), small pulmonary artery (Nakata index <200 mm2/m2), atrioventricular valve incompetence (> or = moderate), distortion of pulmonary artery, anomalous pulmonary venous return, and poor ventricular function as risk factors for the successful completion of Fontan circulation. During the same period, 68 patients underwent the modified Fontan procedure in a one-step fashion (primary group). RESULTS: In the staged group after the bidirectional Glenn shunt, the mean pulmonary arterial pressure and ventricular end-diastolic pressure were both found to have decreased significantly to the same level as those in the primary group, whereas the pulmonary artery demonstrated a significantly smaller size than that in the primary group. Operative morbidity was similar in both groups. Operative mortality was also similar and low in both groups (1.5% in the primary group and 0% in the staged group). CONCLUSIONS: A bidirectional Glenn shunt was found to be a useful interim palliation in high-risk Fontan candidates. This two-staged strategy may extend the operative indications for the Fontan procedure.

Adolescent↗
PubMed1998

Mixed type of total anomalous pulmonary venous connection.

BACKGROUND: The mixed type of total anomalous pulmonary venous connection is a rare condition in which some diagnostic and surgical problems still remain to be solved. METHODS: In 9 patients a single pulmonary vein was connected to the systemic vein at a site different from the drainage site of the confluence of three other pulmonary veins. In 2 other patients, four pulmonary veins made a confluence which had two drainage sites. Correct diagnosis was made in all 7 patients who received cardiac catheterization but only in 5 of the 9 patients by color Doppler echocardiography. Total correction was performed in 3 patients and the single anomalous pulmonary vein was left uncorrected in 8 other patients. RESULTS: There were two in-hospital deaths. Seven patients with a single residual anomalous pulmonary vein have been in good condition without clinical symptoms of congestive heart failure or pulmonary hypertension. CONCLUSIONS: Diagnosis of mixed type of total anomalous pulmonary venous correction by echocardiography is sometimes difficult. When a mixed type is suspected, cardiac catheterization is recommended if the condition of the patient permits it. A single anomalous pulmonary vein may be left uncorrected without serious complications, but close observation is needed to prevent congestive heart failure and pulmonary vascular obstructive disease.

Cardiac Catheterization↗
PubMed1998

Lazaroid U74500A is superior to U74006F in preserving rabbit heart for 24 hours.

BACKGROUND: Lazaroid, a series of 21-aminosteroids, has been shown to reduce free-radical-mediated injury after ischemia and reperfusion. Recent in vitro studies have demonstrated that, among the various compounds studied, the most efficient agent was U74500A. The question is whether these findings apply to the whole heart experiencing ischemia-reperfusion injury. In this study we compared the myocardial protective effects of U74006F, the only clinical candidate, and U74500A. METHODS: An isolated rabbit heart preparation perfused with the blood from a support rabbit was used. All hearts were divided into three groups according to the administration of U74500A (4 mg/kg, group A; n = 7), U74006F (4 mg/kg, group F; n = 7), or solvent (group S; n = 7) to the donor rabbit before preservation. After 24 hours of preservation with University of Wisconsin solution at 0 degrees C, all hearts were perfused with cross-circulated blood for 60 minutes with the Langendorff mode followed by 40 minutes in the working mode. RESULTS: After 10 minutes of reperfusion the serum lipid peroxide levels were significantly (p < 0.05) lower in group A (0.62+/-0.31 nmol/mL) than those in group S (2.1+/-1.3 nmol/mL) and group F (1.0+/-0.6 nmol/mL). The aortic flow rate at 10 mm Hg of left atrial pressure was significantly higher in group A (164+/-37 mL/min) than that of other groups (71+/-28 mL/min in group S and 97+/-28 mL/min in group F). There were no significant differences in high-energy phosphate levels after reperfusion among the three groups. CONCLUSION: These data imply that U74500A inhibits lipid peroxidation and prevents ischemia-reperfusion injury more efficiently than U74006F.

Animals↗
PubMed1998

Effects of amrinone, a phosphodiesterase inhibitor, on right ventricular/arterial coupling immediately after cardiac operations.

OBJECTIVE: Amrinone, a selective phosphodiesterase III inhibitor, is reported to have a potent inotropic effect on the left ventricle, but the effects of this drug on right ventricular contractility in the clinical setting are unknown. The concept of ventricular/arterial coupling was applied to investigate the effects of amrinone on right ventricular contractility and afterload with transesophageal echocardiography. METHODS AND RESULTS: The study was performed in the intensive care unit with 11 patients who had undergone cardiac operations. Right ventricular cross-sectional area was measured with transesophageal echocardiography equipped with a capability of automated border detection as a surrogate for right ventricular volume. Multiple pressure-area loops were obtained by reducing preload to measure end-systolic elastance and effective arterial elastance. External work and pressure-volume area were also measured to calculate the efficiency of energy transfer from pressure-volume area to external work. Nitroprusside (0.3 to 0.5 microg x kg(-1) x min(-1)) and amrinone (1 mg x kg(-1) intravenously followed by 10 microg x kg(-1) x min(-1)) were administered. With nitroprusside infusion, end-systolic elastance and effective arterial elastance remained unchanged (end-systolic elastance, 4.73 +/- 2.18 mm Hg/cm2 to 4.65 +/- 2.09 mm Hg/cm2; effective arterial elastance, 8.05 +/- 3.84 mm Hg/cm2 to 7.70 +/- 3.64 mm Hg/cm2). In contrast, amrinone reduced afterload (effective arterial elastance, 8.82 +/- 3.99 mm Hg/cm2 to 7.05 +/- 4.01 mm Hg/cm2, p = 0.004) and enhanced contractility (end-systolic elastance, 4.47 +/- 1.79 mm Hg/cm2 to 6.56 +/- 2.22 mm Hg/cm2, p = 0.007). Consequently, amrinone decreased the ventricular/arterial coupling ratio (effective arterial elastance/end-systolic elastance, 2.40 +/- 1.45 to 1.16 +/- 0.63, p = 0.009) and improved the efficiency of energy transfer (external work/pressure-volume area, 0.44 +/- 0.15 to 0.54 +/- 0.15, p = 0.013). CONCLUSIONS: Right ventricular pressure-area relations obtained with transesophageal echocardiography could successfully separate the simultaneous change in right ventricular systolic mechanics and afterload caused by amrinone. Amrinone caused enhancement of right ventricular contractility and afterload reduction.

Adult↗
PubMed1998

Increase in the peripheral lymphocyte populations expressing CD54 (ICAM-1) after hyperthermic isolated limb perfusion in patients with malignant melanoma: an analysis of four cases.

The lymphocytes isolated from perfused or non-perfused circulations before, during, and after hyperthermic isolated limb perfusion (HILP) in the four patients with malignant melanoma were analysed for the expression of CD54 (ICAM-1), CD58 (LFA-3), CD4, CD8, HLA class I and class II in order to investigate the mechanism(s) of the activation of such immunocompetent cells as natural killer (NK)-cells or T-lymphocytes by HILP. It was thus found that the lymphocyte populations expressing CD54 increased significantly 1 day after HILP in the four patients examined. The lymphocyte populations expressing CD58 apparently increased. It was also found that the NK-cell and T-lymphocyte activities increased during or after HILP in the present four cases as observed previously in the other melanoma patients. These results indicate that our HILP system may augment the immunological activities through the mechanisms of the induction of CD54 or CD58 expression in the peripheral lymphocytes of the melanoma patients who receive HILP.

Adult↗
PubMed1998

Arresting donor hearts with extracellular-type cardioplegia prevents vasoconstriction induced by UW solution.

The effects of arresting donor hearts with University of Wisconsin solution was investigated. Donor dogs were divided into two groups according to the technique used for arresting the heart. In group I (n = 6) the heart was arrested with University of Wisconsin solution, whereas in group II (n = 6) extracellular-type cardioplegia (K+ = 20 mmol/liter) was used to induce cardioplegic arrest. Aortic root pressure was measured during the infusion of solution at constant flow. In both groups, the hearts were then flushed and stored in cold University of Wisconsin solution for 6 h. The hearts were transplanted orthotopically and disconnected from cardiopulmonary bypass. Left ventricular function was evaluated by pressure-volume relations using a conductance catheter. Peak aortic root pressure during the infusion was significantly higher in group I than in group II, although post-transplant left ventricular function was similar in both groups. Although there was no difference in cardiac function after implantation, donor hearts should be arrested by extracellular-type cardioplegia to prevent coronary vasoconstriction associated with preservation in University of Wisconsin solution.

Adenosine↗
PubMed1998

Temperature dependency of thermodynamic parameters in interactions between hen egg-white lysozyme (HEL) and anti-HEL antibodies.

We examined temperature dependency of thermodynamic parameters in the interactions between hen egg-white lysozyme (HEL) and anti-HEL antibody, D1.3, and two mutant antibodies. The DeltaH degrees values appeared to decrease biphasically in the temperature range from 10 to 45 degrees C with the apparent inflection point around 30 degrees C. The DeltaG degrees calculated from the KA values showed only small differences because of entropy and enthalpy compensation. It has been argued that large negative values of heat capacity change (DeltaCp degrees), if observed, are mainly derived from hydrophobic interactions. However, the observed DeltaCp degrees values were too high to be ascribed only to hydrophobic interactions. Moreover, addition of methanol did not cause a decrease in the absolute value of DeltaCp degrees.

Amino Acid Substitution↗
PubMed1998

Protein C anticoagulant system in patients with interstitial lung disease.

Excessive procoagulant activity in the alveolar space may play a relevant role in the pathogenesis of pulmonary fibrosis. Hypercoagulability results from the disruption of the balance between the procoagulant and anticoagulant factors. The aim of this study was to assess the levels of molecular markers of the anticoagulant protein C (PC) pathway in the bronchoalveolar lavage fluid (BALF) and plasma of 11 patients with idiopathic pulmonary fibrosis (IPF), 14 with sarcoidosis and 16 with collagen vascular disease (CVD)-associated interstitial lung disease (CVD-ILD). Six healthy nonsmoking volunteers served as control subjects. BALF concentrations of the marker of clotting activation, thrombin- antithrombin III complex (TAT), in patients with sarcoidosis and CVD-ILD were significantly greater than those in control subjects. PC levels in BALF were markedly higher in patients with IPF (610 +/- 150 ng/ml), sarcoidosis (680 +/- 170 ng/ml), and CVD-ILD (1,580 +/- 600 ng/ml) than in control subjects (230 +/- 140 ng/ml). BALF concentrations of activated PC-PC inhibitor (APC-PCI) complex were significantly decreased in IPF (0.46 +/- 0.16 ng/ml), sarcoidosis (0. 43 +/- 0.11 ng/ml), and CVD-ILD (0.50 +/- 0.15 ng/ml) patients as compared with control subjects (1.08 +/- 0.23 ng/ml). APC-PCI/PC ratios were significantly lower in patients with IPF (2.70 +/- 1.74 ng/microg), sarcoidosis (1.94 +/- 0.82 ng/microg), and CVD-ILD (1.89 +/- 0.68 ng/microg) than in control subjects (15.91 +/- 8.45 ng/microg). Plasma levels of APC- PCI and the APC-PCI/PC ratio were also significantly decreased in patients with CVD-ILD as compared with control subjects. Overall, these findings suggest that decreased PC activation with increased procoagulant activity occurs in patients with ILD.

Antithrombin III↗
PubMed1998

Effect of L-lactic acid on calcium absorption in rats fed omeprazole.

We examined the effect of L-lactic acid on calcium absorption in male Wistar rats made achlorhydric by dietary omeprazole, a proton pump inhibitor. The dietary omeprazole intake (0.03 g/100 g of diet) increased the gastric pH and decreased the apparent calcium absorption ratio. Dietary famotidine (0.03 g/100 g of diet), an H2-receptor antagonist, and lower doses of omeprazole (0.005 or 0.01 g/100 g of diet) did not affect the gastric pH or the calcium absorption. In a second experiment, dietary lactic acid (0.5, 1.0, or 2.5 g/100 g of diet) increased the intestinal calcium absorption dose dependently in rats fed omeprazole (0.03 g/100 g of diet). The gastric pH was significantly decreased only in the rats fed higher doses of lactic acid (1.0, or 2.5 g/100 g of diet). In a third experiment, a dietary sour milk beverage containing lactic acid (0.5 g/100 g of diet) increased the intestinal calcium absorption, but did not affect the gastric pH in rats fed omeprazole (0.03 g/100 g of diet). Although the significance of gastric acid in terms of overall calcium absorption is not known, under the present experimental conditions, the inhibition of gastric acid secretion by dietary omeprazole decreased the apparent calcium absorption, and the dietary lactic acid prevented the calcium absorption in rats fed omeprazole.

Animals↗
PubMed1998

Effect of L-lactic acid on the absorption of calcium in gastrectomized rats.

The effect of dietary L-lactic acid (LA), (0.5, 1.0, or 2.5 g/100 g of diet) on the absorption of calcium in gastrectomized rats was evaluated for 28 d. Calcium phosphate was used as a source of calcium. The apparent calcium absorption ratio and the calcium contents of the femur and tibia in gastrectomized rats fed the control diet were significantly less than those in sham-operated rats. In the gastrectomized rats, the apparent calcium absorption ratio and the calcium contents of bone in the rats fed the lower doses of LA diets (LA 0.5 or 1.0 g/100 g of diet) were not affected; however, the apparent calcium absorption ratio and the calcium contents of bone in the rats fed the highest doses of LA diet (LA 2.5 g/100 g of diet) were greater than those in gastrectomized rats fed the control diet. Dietary LA (2.5 g/100 g of diet) also enhanced the phosphorus absorption and bone phosphorus content in the gastrectomized rats. We speculated that the highest dose of dietary LA might be associated with the dissolving of a water-insoluble form of calcium salt in the diet, thereby facilitating the calcium absorption and resulting in increased bone calcium content in gastrectomized rats.

Animals↗
PubMed1998

[Relapsing pneumothorax secondary to thin-walled cavitary pulmonary metastasis from angiosarcoma of the scalp].

A 79-year-old woman was given a diagnosis of scalp angiosarcoma. Treatment with interleukin-2 and radiotherapy aclieved a complete response. However, a few months later, the patient presented with multiple thin-walled cavitary metastases in the right lung and pneumothorax. The pneumothorax was successfully treated but soon relapsed. The patient died of respiratory failure at home. Lung metastasis of malignant tumors should be considered one cause of relapsing pneumothorax.

Aged↗
PubMed1998

[Reoperation after repair of complete transposition of the great arteries].

Atrial switch operation (Mustard operation, Senning operation). Rastelli operation, and arterial switch operation (Jatene operation) have been performed as definitive methods for the repair of complete transportation of the great arteries (TGA). Obstruction of the superior vena cavae and the pulmonary venous tract are common reasons for reoperation after the atrial switch operation. Stenosis of the extracardiac conduit is inevitable after the Rastelli operation is performed. Reconstruction of the right ventricular outflow tract using Danielson's procedures may eliminate the need for reoperation. The REV procedure at the time of initial operation may decrease the incidence of reoperation after the repair of TGA with a ventricular septal defect and left ventricular outflow tract obstruction. Pulmonary stenosis is the most common reason for reoperation after the arterial switch operation. Reconstruction of the pulmonary artery using pacifico's method or the single pantaloon patch technique with autologous pericardium is expected to reduce the occurrence rate of postoperative pulmonary stenosis. Postoperative aortic regurgitation is uncommon and is usually mild in grade. However, because the pulmonary sinus is shallow and fragile compared with the aortic sinus of Valsalva, the durability of neoaortic valves remains to be elucidated during long-term follow-up.

Aortic Valve Insufficiency↗
PubMed1998

[An autopsied case of purulent meningitis associated with ocular flutter].

We report a 72-year-old autopsied case of purulent meningitis associated with ocular flutter. She was admitted to our hospital because of disturbances of consciousness and fever. Physical examination revealed fever, tachycardia, and tachypnea. Neurological examination showed disturbance of consciousness (Japan Coma Scale 30), agitated state, anisocoria, sluggish and fixed reaction of pupils to light, and nuchal stiffness. Routine blood examination showed leukocytosis, thrombocytopenia, positive CRP, and elevated myocardial enzymes. Cerebrospinal fluid revealed pleocytosis with predominant leukocytes, elevated protein, and decreased glucose (22% of blood glucose), and Streptococcus pneumoniae was proved in culture. Brain CT scan revealed no abnormal findings. Electrocardiography showed tachycardia, left axis deviation, and elevated ST segment in aVF, and V3-V6. Ultrasonic echocardiography revealed slight hypokinesis of the left anterior wall, septum, and apex. She was diagnosed as having purulent meningitis, myocarditis, probable encephalitis. Thus, antibiotics, acycrovir, glycerol, and aspirin were administrated. But her respiration deteriorated and ocular flutter was observed for 15 minutes. After that, She required artificial ventilation and eventually died after 29 hours the admission to our hospital. Pathological examination revealed leukocyte accumulation in the arachnoid space of the derebral surface, especially frontal and parietal lobes. Uncal herniation was not observed. The brainstem and cerebellum were histologically within normal limits. These findings suggest that ocular flutter observed in this patient was caused by functional damage of the brainstem.

Aged↗