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Biomedical subjects

S Bando

Publications and source records attributed to S Bando.

At least 19 recordsLinked to original sources
PubMed1996

Effects of verapamil and magnesium sulfate on electrophysiologic changes during acute myocardial ischemia and following reperfusion in dogs: comparative effects of administration by intravenous and coronary sinus retroperfusion routes.

The authors evaluated the effects of verapamil (Ve) and magnesium sulfate (Mg) on the electrophysiologic changes induced in dogs during acute myocardial ischemia and following reperfusion. The effects of their intravenous (i.v.) administration and administration by coronary sinus retroperfusion (CSR) were also compared. Sixty-five dogs were divided into five groups: Ve-i.v.: 9 dogs, 0.1 mg/kg; Ve-CS: 9 dogs, 0.05 mg/kg; Mg-i.v.: 12 dogs, 20 mg/kg; Mg-CS: 11 dogs, 10 mg/kg, control: 24 dogs. The left anterior descending coronary artery was ligated for ten minutes, then quickly reopened. The changes in ventricular effective refractory period (ERP) and intramyocardial conduction time (ICT) were determined during ischemia and following reperfusion. The authors observed a shortening of the ERP and a prolongation of the ICT in the control group versus an attenuation of those effects in all other groups. The ERP was shortened to a lesser extent in the Mg-i.v. group than in the Ve-i.v. group. Drug administration by CSR inhibited the changes in ERP and ICT to a greater extent than i.v. administration, even though the dose given by CSR was one-half the i.v. dose. Ventricular fibrillation (Vf) occurred in 12 of 24 dogs (50%) in the control group during ischemia, and in 5 of 12 dogs (41.7%) following reperfusion. Vf occurred during ischemia and following reperfusion, respectively, in 22.2% and 0% in the Ve-i.v. and Ve-CS groups, in 25% and 22.2% in the Mg-i.v. group, and in 9.1% and 10% in the Mg-CS group. Thus, verapamil and magnesium sulfate inhibited the electrophysiologic changes and prevented ventricular arrhythmias during myocardial ischemia and following reperfusion. Administering the antiarrhythmic agent by coronary sinus retroperfusion may be useful for treating patients with acute myocardial infarction with intractable arrhythmias, according to these experimental results.

Animals↗
PubMed1995

Compositions of very low density lipoprotein subfractions from patients with polydisperse low density lipoproteins.

In some hyperlipidemic patients, low density lipoprotein (LDL) shows several peaks (polydisperse) on polyacrylamide gel disc electrophoreses, though LDL usually shows a single peak (monodisperse). In order to clarify the relationship between the LDL polydispersion and VLDL heterogeneity, LDL and VLDL were prepared from hyperlipidemic patients sera with mono- and polydisperse LDL by sequential ultracentrifugation and fractionated by gradient ultracentrifugation and their compositions were analyzed. Polydisperse LDL was rich in triacylglycerol (TG) and poor in esterified cholesterol (CE) as compared with monodisperse LDL and consisted of the lowest and the medium density subfractions when the LDL was separated into six subfractions. The monodisperse LDL was composed of a single major subfraction of a medium density. VLDL from the patients with polydisperse LDL was relatively rich in the dense and poor in the buoyant subfractions as compared with that from the patients with monodisperse LDL. The subfractions in the former contained more CE and less TG than the corresponding subfractions in the latter. There were no significant differences in the apolipoprotein compositions between those VLDLs. The results suggest that polydisperse LDL might be originated from VLDL that differs in particle sizes, densities and compositions from ordinary VLDL.

Adult↗
PubMed1995

Binding and functional characterization of alpha-2 adrenoceptors in isolated swine myometrium.

1. Alpha-adrenoceptors in the uterus of cyclic mature pigs were investigated for their binding characteristics as shown by a radioligand study employing [3H]-prazosin and [3H]-rauwolscine, and the alpha-adrenoceptors were studied for their functional roles on motility as shown mechanically in vitro. 2. Noradrenaline (10 nM-1 microM) caused a tetrodotoxin-resistant contraction in the cornual longitudinal muscle. The response was decreased by yohimbine (10 nM-1 microM) but not by prazosin (1 microM). 3. Clonidine, xylazine, phenylephrine and methoxamine also elicited a concentration-dependent contraction of the cornual longitudinal muscle. The ranking according to the potency was clonidine > xylazine >> phenylephrine > or = methoxamine. On the other hand, these alpha-adrenoceptor agonists did not elicit contraction of the cornual circular muscle even at 100 microM. 4. Noradrenergic contraction induced by transmural stimulation was significantly decreased by yohimbine (10-100 nM) but not by prazosin (1 microM). 5. The swine myometrium contained both alpha-1 (13%) and alpha-2 (87%) adrenoceptors. The distribution of alpha-adrenoceptors was muscle layer-specific, i.e. the number of both types of adrenoceptors in the longitudinal muscle was four times higher than that in the circular muscle. 6. These results show that although swine myometrium contains both alpha-1 and alpha-2 adrenoceptors, the alpha-2 type is predominant and largely responsible for mediating the excitatory response to both exogenous and endogenous noradrenaline in the cornual longitudinal muscle.

Adrenergic alpha-1 Receptor Agonists↗
PubMed1995

[An advanced invasive thymoma that responded remarkably to neoadjuvant chemotherapy with carboplatin, adriamycin, and etoposide].

A 23-year-old man was admitted to the hospital with hoarseness caused by recurrent nerve palsy. The chest X-ray film and CT scan on admission showed a large mass in the antero-superior part of the mediastinum and a small round mediastinal mass adjacent to right inferior pericardium. Examination of a specimen aspirated from the mediastinal mass revealed thymoma. The tumor was considered to be inoperable because of the pericardial dissemination, and the patient was treated with carboplatin, Adriamycin, and etoposide. After 4 courses of chemotherapy, remarkable regression of both tumors was observed on a chest X-ray film. The patient underwent surgery, and no remaining tumor was found. A combination of carboplatin, Adriamycin, and etoposide may be useful as neoadjuvant chemotherapy for advanced invasive thymoma.

Adult↗
PubMed1994

Noninvasive localization of accessory pathways by magnetocardiographic imaging.

The magnetocardiogram (MCG) is a newly developed method that helps localize a cardiac current source. To test the clinical accuracy of a 7-channel biomagnetic system in the localization of early ventricular depolarization sites, the MCGs of 14 patients with Wolff-Parkinson-White (WPW) syndrome were recorded in a radiofrequency-shielded room. The locations of early ventricular depolarization sites were classified by standard 12-lead electrocardiograms (ECGs) and body surface isopotential mapping. The accessory pathways of 3 patients with WPW syndrome were located in the right free wall and in 11 patients in the left free wall. The three-dimensional (3-D) dipole location was computed every 2 ms from the onset of the QRS complex by the least-square method. These 3-D dipole locations were projected onto a gated magnetic resonance image in order to visualize the propagation of the calculated ventricular source. The results were compared with those obtained by body surface isopotential mapping, and electrocardiographic and electrophysiologic studies. The location of the deduced current dipole at 20 ms correlated well with the location of the accessory pathway by the body surface mappings in 12 of the 14 patients with WPW syndrome. The MCG is capable of precisely determining the 3-D location of a current source in a noninvasive manner and may be of potential benefit in the treatment of WPW syndrome by catheter ablation.

Adolescent↗
PubMed1994

Muscle layer and regional differences in autonomic innervation and responsiveness to transmitter agents in swine myometrium.

1. To clarify possible regional and muscle layer differences in adrenergic innervation of swine myometrium, functional, biochemical and histochemical experiments were performed on longitudinal (LM) and circular (CM) muscle isolated from non-pregnant uteri of 84 gilts. 2. Transmural stimulation (TMS) in the presence of propranolol evoked tetrodotoxin-sensitive contractions in a frequency-dependent manner (2-20 Hz) in LM and CM. The cornual LM contractions were attenuated by phentolamine (1 microM) and by guanethidine (10 microM) though unaffected by atropine (1 microM). Contractions in cervical LM were diminished by atropine but not by phentolamine, and the corpus LM contractions were reduced incrementally by atropine and phentolamine when added sequentially. In CM, the TMS-induced contractions were abolished by tetrodotoxin and atropine in all three regions. 3. In response to noradrenaline (NA) and acetylcholine (ACh), LM contractile intensity was the most potent in cornua, slightly weaker in the corpus and weakest in the cervix. CM was insensitive to NA, and contractile responses elicited by ACh indicated no regional variation. 4. NA content, significantly greater in LM than in CM, was most highly concentrated in cornual LM. Nerves exhibiting glyoxylic acid-induced histofluorescence occurred in both LM and CM, though more abundantly in LM and with notable density in the cornual LM. Cholinesterase activity, distributed evenly throughout the three myometrial regions studied, was more intense in LM than in CM. 5. These results show that, in swine myometrium, innervation in cornual LM is predominantly noradrenergic, cervical LM is mostly cholinergic, and throughout the myometrium the CM layers are principally cholinergic.

Acetylcholine↗
PubMed1993

Unbalanced translocation (1;7) and inversion 16 in a patient with acute myelocytic leukemia.

Pericentric inversion of chromosome 16 has been delineated as a characteristic chromosome abnormality of acute myelomonocytic leukemia with abnormal eosinophils and a favorable prognosis. By contrast, unbalanced translocation (1;7) has been reported as frequently associated with therapy-related leukemia, and patients with this karyotypic abnormality are susceptible to severe infections which lead to a poor prognosis. Here we report the first case of acute myelocytic leukemia in which the complexed chromosomal aberrations of der(7)t(1;7)(cen;cen) and inv(16) were found simultaneously in the patient's leukemia cells. Eosinocytosis has not been observed so far, but life-threatening pneumonia developed during the remission induction therapy.

Bone Marrow↗
PubMed1993

Emergence of acute interstitial pneumonia following high dose interferon delta treatment in a case of chronic myelogenous leukemia.

Here we report a 58-year-old man with chronic myelogenous leukemia in the chronic phase, who developed acute respiratory failure following administration of high dose natural interferon delta (6,300 x 10(4) units/week). Radiological and histological findings were consistent with acute interstitial pneumonia (AIP). Although the pathogenesis remains unclear, it is important to watch for the possible development of AIP when employing interferon delta therapy, especially at high doses.

Acute Disease↗
PubMed1993

Catheter ablation therapy in a case with WPW syndrome complicated by multiple tachyarrhythmias.

WPW syndrome is of importance because of the frequent association of tachyarrhythmias. However, its complication by 3 or more different tachyarrhythmias simultaneously is rare. This paper reports a case of WPW syndrome complicated by paroxysmal atrial fibrillation, atrial flutter, and 2 types of atrioventricular reentrant tachycardia. The tachyarrhythmias could be cured by cauterizing the accessory pathway using catheter ablation with radiofrequency electric current. A 30-year-old man visited to a local physician with an episode of tachycardia which failed to resolve, and a diagnosis of WPW syndrome associated with paroxysmal atrial fibrillation was made. The patient was referred to our hospital for further examination and treatment, and electrophysiological study was performed. During the examination, 2 types of atrioventricular reentrant tachycardia with different heart rates were induced, as well as atrial fibrillation and 2:1 atrial flutter. The presence of a left-sided accessory atrioventricular pathway was confirmed by coronary sinus mapping, and the following day catheter ablation was performed and the accessory pathway was cauterized. Subsequently, the delta wave disappeared from the ECG and no additional episodes of tachycardia occurred. Catheter ablation is still undergoing research as a therapeutic modality. However, because the ablation technique entails little invasion or risk, and is economical, it may well become a mainstream treatment for tachycardia in patients with WPW syndrome in the future.

Adult↗
PubMed1992

Single moving dipole obtained from magnetic field of the heart in patients with left ventricular hypertrophy.

Magnetocardiograms (MCGs) were recorded by means of a second-derivative SQUID (superconducting quantum interference device) magnetometer in 20 normal subjects and 28 patients with left ventricular overload to analyze the activation sequence of the heart and amplitude of estimated current source. In the normal subjects, the dipole was directed to the left and gradually superiorly 40 ms after the beginning of the QRS wave mainly due to the activation of the left ventricle. In the patients with hypertension, the direction and location of the dipoles were similar to those of the normal subjects, but their dipole moments were increased. In the patients with mitral regurgitation, the dipoles of late QRS were directed more inferiorly than in the normal subjects and their amplitude was increased. In the patients with aortic valve disease, the amplitude of the dipoles was increased markedly and their location was deviated more to the left than the dipoles of the normal subjects. We established the criterion for diagnosis of LVO from the dipole moment of 50 ms of 3.13 x 10(-3) A or more. The sensitivity of this criterion is significantly higher in the diagnosis of left ventricular overload than the electrocardiogram (ECG). The present study shows that the moving dipole method is useful to determine the increased electromotive force in patients with left ventricular overload and that sensitivity in diagnosis of left ventricular overload is increased.

Aortic Valve Insufficiency↗
PubMed1992

Two sudden death cases of idiopathic ventricular tachycardia.

It is said that the prognosis of idiopathic ventricular tachycardia (IVT) without organic heart disease is good in general. In this paper, two sudden death cases of IVT are reported. The first case was a 44-year-old male, who was referred to our hospital for further examination and treatment of ventricular tachycardia. Echocardiography did not show obvious organic heart disease. After the patient was diagnosed with IVT, he was given drug therapy at the outpatient clinic. However, about six months later, he died suddenly while playing mahjong late at night. The second case was a 17-year-old male. He was also referred to our hospital by another hospital after being diagnosed with ventricular tachycardia. A diagnosis of IVT was made, for which he was given drug therapy at outpatient clinic. However, the patient discontinued receiving the drug therapy. The patient died suddenly about 3 months after discontinuation of the therapy. Some idiopathic ventricular tachycardia cases have poor prognosis like the present ones. It was considered necessary to thoroughly control and guide patients with their daily life and monitor them carefully about the ingestion of anti-arrhythmic agents.

Adolescent↗
PubMed1992

A case of concealed WPW syndrome with three different reciprocal tachycardias due to triple AV nodal pathways.

Triple atrioventricular nodal pathways (TAVNP) occur occasionally, but it is rare for them to produce more than two different tachycardias. Here we report a case of concealed WPW syndrome with three different tachycardias. During electrophysiologic studies, three different reciprocal tachycardias were induced. Tachycardia #1 was characterized by a cycle length of 230 msec and an A'-H interval of 70 msec. For tachycardia #2, these parameters were 300 msec and 140 msec, while they were 370 msec and 200 msec for tachycardia #3. During all three tachycardias, the earliest atrial activity was observed in the left atrium. Ventriculoatrial conduction occurred following ventricular stimulation, and the earliest atrial activity was observed in the left atrium, indicating the existence of left-sided accessory pathway. Persistence of tachycardia for 15-30 min caused marked pulmonary congestion. The heart rate was very high (260 beats/min) during tachycardia #1, and the pulmonary arterial pressure rose to 40/30 mmHg, with the pulmonary arterial diastolic pressure remaining at about 30 mmHg throughout the tachycardia. It seems that the pulmonary venous pressure rises abnormally during paroxysmal supraventricular tachycardia with a very high heart rate and that pulmonary congestion can easily occur during a short period of tachycardia.

Electrocardiography↗
PubMed1991

Right atrial myxoma with hypervascularity demonstrated by selective coronary angiography.

Cardiac myxoma is the commonest primary cardiac tumor, however, the incidence of right atrial myxoma is very rare. We reported a 71-year-old man with a right atrial myxoma, whose main complaint was fever of unknown origin. Definite diagnosis was confirmed by echocardiography and cineangiocardiography. Venacavogram revealed huge mass which occupied greater part of right atrial cavity. Coronary angiogram revealed the feeding artery arising from left coronary circumflex artery and the sign of hypervascularity. Open heart surgery was performed, and a 4.9 x 4.0 x 3.8 cm tumor was found in the right atrial cavity. Pathological examination showed the findings of myxoma. Postoperative clinical course was uneventful.

Aged↗
PubMed1991

The efficacy of isoproterenol on quinidine induced torsade de pointes.

The efficacy of isoproterenol for torsade de pointes (TdP) was evaluated in 60 dogs. TdP was induced in 34 of 60 dogs (56.7%) after the administration of quinidine sulfate (30 mg/kg). The electrophysiologic effect of isoproterenol (0.5 micrograms/min) was studied in 9 dogs with quinidine induced TdP. Isoproterenol significantly shortened basic cycle length, corrected QT interval, effective refractory period (ERP) and dispersion of ERP and increased ERP/QT. Isoproterenol prevented the occurrence of TdP in all dogs. These findings suggest that isoproterenol decreases the dispersion of ventricular refractoriness and may be useful in the treatment of drug induced TdP.

Animals↗
PubMed1991

[Efficacy of isoproterenol, magnesium sulfate and verapamil for torsade de pointes].

The efficacy of isoproterenol, MgSO4 and verapamil for torsade de pointes was evaluated in 60 dogs. Torsade de pointes was induced in 28 out of 60 dogs (46.7%) by ventricular stimulation after administration of quinidine sulfate (30 mg/kg). The electrophysiologic effect of isoproterenol (0.5 micrograms/min drip infusion) was studied in 9 dogs with torsade de pointes, in 9 dogs with MgSO4 (30 mg/kg), and in 10 dogs with verapamil (0.1 mg/kg bolus injection followed by 0.01 mg/kg/min drip infusion). If the first dose of these drugs was ineffective, ventricular stimulation was performed after the additional administration of the same dose. Isoproterenol significantly decreased QTc, ERP and dispersion of ERP but increased ERP/QT. MgSO4 significantly increased ERP and ERP/QT, however dispersion of ERP did not change. Verapamil induced no electrophysiologic changes in ventricular refractions . Isoproterenol prevented the occurrence of torsade de pointes in all dogs (100%), MgSO4 in 7 of 9 dogs (77.8%, 30 mg/kg in three and 60 mg/kg in four) and verapamil in 4 of 10 dogs (40%, 0.1 mg/kg in two and 0.2 mg/kg in two). These findings suggest that isoproterenol and MgSO4 increased ERP/QT, showing one of their antiarrhythmic effects. It also shows that isoproterenol and MgSO4 may be useful in the treatment of torsade de pointes.

Animals↗
PubMed1990

Structure of (R)-tetrahydro-2-furancarboxylic acid monohydrate.

C5H10O4, Mr = 134.31, monoclinic, P2(1), a = 11.670 (2), b = 6.177 (3), c = 10.704 (2) A, beta = 115.11 (2) degrees, V = 698.7 (4) A3, Z = 4, Dm = 1.26, Dx = 1.28 g cm-3, Cu K alpha, lambda = 1.54178 A, mu = 9.69 cm-1, F(000) = 288, room temperature, R = 0.046 for 1047 reflections with [Fo[ greater than 3 sigma(F). There are two independent molecules of the title compound in the crystal. No twofold symmetry is observed in the tetrahydrofuran rings. Hydrogen bonds between water molecules and carboxylic acid groups stabilize the crystal structure.

Furans↗
PubMed1990

Vector U loop in patients with idiopathic cardiomyopathy.

The U loops of vectorcardiograms were recorded in 50 normal subjects, 10 patients with dilated cardiomyopathy (DCM group), and 83 patients with hypertrophic cardiomyopathy (HCM group). The HCM group was divided into three subgroups: those with obstructive hypertrophic cardiomyopathy (HOCM), nonobstructive hypertrophic cardiomyopathy (HNCM), and apical hypertrophy (APH). The spatial characteristics of the U loop were examined qualitatively and quantitatively and were correlated with echocardiographic findings. The magnitude of the U loop was significantly larger in the HCM group, especially in the APH subgroup, than in the normal subjects, but it was not larger in the DCM group. The maximum U vector was significantly displaced anteriorly and to the right in the DCM and HCM groups, especially the APH and HNCM subgroups. In the HNCM and APH subgroups, the magnitude of the U loop correlated significantly with the thickness of the posterior wall of the left ventricle, but not with that of the interventricular septum. These findings suggest that the U loop is related to hypertrophy of the apex and the posterior wall of the left ventricle.

Adult↗