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Biomedical subjects

E Tanaka

Publications and source records attributed to E Tanaka.

At least 487 records · Page 27Linked to original sources

Mechanism and prediction of sudden cardiac death in arrhythmia patients using electrophysiological studies.

Thirty nine cases, in which sudden cardiac death (SCD) was suspected, were studied to evaluate the mechanism and the prediction of SCD in arrhythmia-patients using electrophysiological studies (EPS). The 39 cases (28 male and 11 female) were located by surveying 2098 patients who underwent EPS for the evaluation of arrhythmias. Age at time of EPS ranged from 4 to 86 years, average 50.5 years. Time from EPS to death was 2 to 163 months, average 27.9 months. Underlying heart disease was: dilated cardiomyopathy in 11, old myocardial infarction in 5, ischemic heart disease in 5, hypertensive heart disease in 5, valvular heart disease in 3, hypertrophic cardiomyopathy in 2, arrhythmogenic right ventricular dysplasia in 1, myocarditis in 1, sarcoidosis in 1, cor pulmonale in 1, and no obvious heart disease in 4. Fifteen had a permanent pacemaker implanted. SCD in cases without a permanent pacemaker (24 cases): 2 had chronic complete A-V block (one BH block, one HV block), 1 had advanced A-V block (HV block), 3 had bundle branch block with first degree HV block, 9 had ventricular tachycardia (VT), 3 had sick sinus syndrome (SSS), 3 had paroxysmal atrial flutter, 1 had WPW syndrome and paroxysmal atrial fibrillation, 1 had paroxysmal atrial tachycardia, and 3 had premature ventricular beats and first degree HV block. SCD in cases with permanent pacemaker (15 cases): 5 had SSS, and 10 had A-V block. In 3 of the 5 with SSS and 7 of the 10 with A-V block, VT was found before pacemaker implantation. In our study, brady and tachyarrhythmias coexisted in 25 cases (64%).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

Antipyrine metabolism in female Lewis and Dark Agouti strains of rats, which are extensive and poor metabolizers of debrisoquine, respectively.

The metabolism of antipyrine (AP) was investigated in female rats of the Dark Agouti (DA) and Lewis (L) strains, which have been proposed as models for human poor and extensive metabolizers of debrisoquine (DB), respectively. Following i.p. injection of 50 mg/kg of AP, the rate of production of 4-hydroxy-antipyrine in 24-hr urine was increased significantly in the L strain. The results suggested that different cytochrome P-450 isozymes were responsible for hydroxylation of AP and DB and showed interphenotype differences between the two strains.

Animals↗

[Infection by non-A, non-B acute viral hepatitis in hospital employees].

The aim of this study is to evaluate the risk of infection of non-A, non-B acute hepatitis (NANB-AH) in hospital employees. Among 593 patients with acute viral hepatitis (AVH), hospital employees were 3/147 (2%) in type A, 19/174 (11%) in type B and 21/272 (8%) in non-A, non-B (NANB). All 43 patients were medical staffs such as doctors, nurses and laboratory technicians. Out of 21 patients with NANB hepatitis of hospital employees, 7 were doctors, 14 nurses and 6 laboratory technicians. Eight of them had preceding accidental needlestick exposures. Out of 17,290 employees of our hospital during 18 years, 27 medical persons developed AVH. They were 2 hepatitis A, 10 hepatitis B and 15 hepatitis NANB. No non-medical staff developed AVH. Out of 15 NANB hepatitis patients, 7 had needlestick accidents 4 to 6 weeks before development of the illness, and all donor patients showed liver diseases. During 3 years (1985 to 1987), there were 116 needlestick accidents in our hospital which happened in medical staffs alone, and 50 of them were NANB hepatitis-related accidents. Three ml of human immune serum globulin (ISG) was administered intramuscurally just after accidents to 23 persons but not to 27 persons. NANB hepatitis were developed in 2 doctors who were not treated with ISG. In conclusion, NANB hepatitis occurred in hospital employees especially in medical staffs.

Accidents, Occupational↗

[Limitation of RI imaging in evaluating lung function test--development of new methods].

We developed two methods for determining the regional distribution of (1) RV/TLC and air trapping during forced expiration and (2) the ratio or pulmonary blood volume to blood flow. 1) The regional distributions of RV/TLC and air trapping ratio: A.T.R. (air trapping caused by forced expiration) were measured in respiratory disease cases and normal subjects using Xe-133 gas. In normal subjects, RV/TLC gradually decreased from the apex to the base of the lung. A.T.R. was very low in all lung fields. In chronic emphysema (CPE), both RV/TLC and A.T.R. were much higher than the value in normal subjects at the highly diseased areas. In contrast, in case of diffuse panbronchiolitis (DPB), RV/TLC remained within the normal range and A.T.R. was increased considerably in the diseased regions. These results suggest that airway obstruction occurs only during the forced expiration in DPB. 2) The regional distribution of the ratio of pulmonary blood volume to blood flow (tau p) were measured in a normal subject and a case of mitral regurgitation. In both subjects, the distribution of 1/tau p consisted of three zones: upper, middle and lower. The distribution of 1/tau p was constant in the middle zone, but, in the upper and lower zones, it decreased in proportion to the distance from the middle zone. In the case of mitral regurgitation, the middle zone shifted to the apex. Applying the results to the lung perfusion model proposed by West, it was suggested that these phenomena might reflect the increase of the pulmonary venous pressure and the perfusion disorder in the lower lung.

Blood Volume↗

[Impedance analysis using the random noise oscillation method and a body box].

The frequency characteristics (at 10-40 Hz) of airway (Za) and tissue (Zt) impedances in patients with chronic bronchitis (CB), chronic pulmonary emphysema (CPE) and interstitial pneumonitis (IP) were examined using the random noise oscillation method and a body box. Compared with normal subjects, Zar (r:real part) was elevated in cases of CB, but not in those with CPE. Zai (i:imaginary part) was decreased in cases of CB and CPE. Applying an electromechanical analogy to these results, it was inferred that CB increases both central and peripheral airway resistance, while CPE only increases peripheral resistance. In CPE, but not in CB, Ztr fell; only Zti decreased in IP, which suggests a decrease in mass per unit of lung tissue in CPE and a loss of pulmonary compliance in IP. We also measured the impedance of a dog with acute pulmonary edema induced by oleic acid. Zar an Ztr were increased but Zti was decreased, which corresponded with the increase of airway resistance due to hypersecretion and the decrease of lung compliance. We conclude that this method is useful in differentiating interstitial disorders from COLD, and also CB from CPE, because it can detect lung stiffness and can identify sites of airway narrowing.

Adult↗

[Direct arrhythmia surgery in ventricular tachycardia: an experience with 18 consecutive patients].

18 patients with ventricular tachycardia (VT) underwent direct arrhythmia surgery between 1984 and 1988. There were 8 patients with ischemic VT, and 10 with nonischemic VT. Operative technique consisted of ablative procedures of the arrhythmogenic area determined by pre- and intraoperative mapping. Induced VT was usually unstable and transient during operation, so that instantaneous multi-point mapping was necessary in almost cases. For VT originated in the left ventricle or interventricular septum, the earliest excitation point determined by the epicardial mapping did not always predict the endocardial arrhythmogenic focus. Pre- and/or intraoperative endocardial mapping was important in this regard. Cryocoagulation (-150 degrees C, 120 sec) was mainly used as an ablative procedure; for ischemic VT, endocardial resection was added, and in nonischemic VT originated in the right ventricular outflow tract, transmural resection was combined with the cryoablation. In performing surgery for nonischemic VT, care must have been taken to make transmural cryocoagulation because the arrhythmogenic focus could exist intramurally. There were no operative deaths. In one patient with nonischemic VT, reoperation was required. After a mean follow-up of 17 month, all the patients are free from sustained VT.

Adolescent↗

Electromyography of the pharyngeal musculature: technical considerations.

Thirty-one EMG studies of the pharyngeal musculature using three types of electrodes were performed. Electrode characteristics are compared according to criteria developed specifically for the pharynx; techniques for electrode positioning are described in detail; and technical difficulties encountered in performing these studies are discussed. Needle electrodes were best for analyzing individual potentials. For analyzing the timing of myoelectric activity, we preferred the hooked wire electrode (for palatopharyngeus or cricopharyngeus) or bipolar suction electrode (for pharyngeal constrictors). Pharyngeal electromyography is technically feasible and has a role in studying normal and pathologic processes.

Deglutition↗

Effects of H2-receptor antagonists on ethanol metabolism in Japanese volunteers.

The effects of H2-receptor antagonists (cimetidine, ranitidine, and famotidine) on ethanol metabolism were investigated. Neither in aldehyde dehydrogenase (ALDH)-1 deficient subjects nor in those with normal ALDH-1, did the three H2-receptor antagonists and placebo differ in their effects on the pharmacokinetic parameters of ethanol (i.e. peak time (tmax), metabolic rate (k0), peak serum concentration (Cmax), volume of distribution (V) and area under the concentration-time curve (AUC). The AUC of acetaldehyde was slightly but significantly (P less than 0.05) larger only after treatment with cimetidine. Cmax and tmax of acetaldehyde were unchanged.

Acetaldehyde↗

Age changes in secretory function of male and female rat parotid glands in response to methoxamine and pilocarpine.

Saliva secreted in response to methoxamine and pilocarpine was collected from the cannulated ducts of both parotid glands of male and female rats at weekly age intervals from three to 10 weeks, and at 3.5, 8, and 15 months of age. It was analyzed for the concentrations of protein, potassium, calcium, inorganic phosphate, and for amylase activity. The type of protein were determined electrophoretically, and an amino acid analysis of the total protein was also carried out. The wet weights of the glands increased substantially up to eight weeks of age, then reached almost plateau values, and finally tended to decrease at 15 months of age in both sexes. The salivary volumes secreted in response to methoxamine and pilocarpine were positively correlated with the parotid gland weights in both sexes. The concentrations of protein, potassium, and inorganic phosphate were inversely related to the salivary flow rates only at relatively low rates of flow. The amylase activity was positively correlated with the concentration of protein, independent of the nature of the stimulus, age, and sex. With methoxamine as a stimulus, the amylase activity was positively correlated with the concentration of calcium, independent of age and sex. The types of protein and amino acid concentrations were independent of the nature of the stimulus, age, and sex up to 15 months of age. However, in parotid saliva of several rats at 8 and 15 months of age, unusual proteins were observed electrophoretically, independent of the nature of the stimulus and sex.

Aging↗

Sex-related differences in hepatic drug-oxidizing capacity of streptozotocin-induced diabetic rats.

Male and female animal models of diabetes were prepared by treating rats with streptozotocin (STZ). Trimethadione (TMO) metabolism was depressed in male but increased in female diabetic rats. The insulin treatment normalized rats of both sexes. Serum dimethadione/TMO ratios at 2 h correlated with the elevated blood glucose levels in male and female control, the STZ-induced diabetic and the insulin-treated diabetic rats. Treatment with STZ in male rats affected the metabolism of antipyrine, decreasing urinary excretion of norantipyrine (NORA) urine but increasing elimination of 4-hydroxyantipyrine (OHA). In female diabetic rats, the amounts of the three major metabolites, NORA, OHA and 3-hydroxymethyl-3-norantipyrine and the total (conjugate + free) were increased compared to the control. In the insulin-treated groups, these changes were normalized. In conclusion, our study showed that the effect of STZ-induced diabetes on drug metabolism varies with the sex and the drugs used. Insulin normalized all these diabetic changes.

Animals↗

Clinical significance of Vanghan Williams classification for treatment of ventricular tachycardia: study of class IA and IB antiarrhythmic agents.

UNLABELLED: Ninety-eight cases of ventricular tachycardia (VT) were studied using clinical electrophysiological (EP)-pharmacological assessment to compare the efficacy of class IA (disopyramide-DP, procainamide-PA) and class IB (mexiletine-Mex, Lidocaine-Lid, aprindine-AP) agents available in Japan, and to evaluate the clinical significance of class subdivisions for the treatment of VT. In assessing the efficacy of drugs, we evaluated their ability to prevent and terminate induced sustained VT as well as their ability to suppress spontaneous premature ventricular beats (VPB). I. EP properties: DP significantly extended QTc, ERPRV, and the coupling interval by which VT or repetitive ventricular response (RVR) was induced. On the other hand, Mex and AP had no effect. Although no significant extension of QRS width was found, the significant extension of the interval from extrastimulus to the first induced VT or RVR complex by the three drugs indicates that all have suppressive effects on conduction velocity within the reentry circuit. II. CLINICAL SIGNIFICANCE: Correspondence of preventive effects was 67% for DP and PA (class IA), 54% for Mex and Lid (class IB), 55% for DP and Mex, 27% for AP and Mex, and 25% for AP and DP. Correspondence of terminating effect was 85% for DP and PA, 80% for DP and AP, 77% for DP and Mex, 75% for Mex and Lid, and 63% for Mex and AP. For suppression of spontaneous VPB's, correspondence rate was 100% for DP and PA, 39% for DP and Mex, 64% for Mex and Lid, 61% for Mex and AP, and 69% for DP and AP.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

The effect of H2-receptor antagonists on antipyrine and pentobarbital metabolism in male and female rats.

Pretreatment of male and female rats with cimetidine decreased the amount of 3-hydroxymethylantipyrine in the 24-hr urine, but urinary antipyrine and 4-hydroxyantipyrine were increased compared to that of the corresponding control rats. On the other hand, the amount of norantipyrine and the total amount of antipyrine and its metabolites were not changed by cimetidine, ranitidine and famotidine. These data suggest that ranitidine and famotidine have little effect on the microsomal mixed function oxidase system in male and female rats.

Animals↗

Motions of the posterior pharyngeal wall in swallowing.

The motions of the posterior pharyngeal wall during swallowing were studied in four asymptomatic males using a new method for videoradiography. Radiopaque markers of 4 mm diameter were affixed to the pharyngeal wall by suction. Ventrodorsal and axial components of motion were measured frame by frame. Large axial motions occurred during the pharyngeal stage of swallowing. Cephalad displacement of each marker occurred early and was followed by caudad motion. Within the pharyngoesophageal segment, there were cephalocaudal motions measuring as much as 25 mm. A late caudad motion beyond the reference position was observed in this segment in two participants. This late motion may play a role in passing the bolus through the pharyngoesophageal segment. The findings support the concept of an "engulfment" mechanism in pharyngeal kinesiology.

Adult↗

Relationship between hepatitis B virus deoxyribonucleic acid, HBeAg/anti-HBe status in serum and HBcAg in liver: its clinical significance in chronic HBsAg carriers.

Sera and biopsied liver specimens from 45 hepatitis B surface antigen (HBsAg) carriers both with or without overt liver diseases and negative for anti-delta antibody, were examined for markers of hepatitis B virus (HBV) infection: hepatitis B e antigen (HBeAg), hepatitis B virus deoxyribonucleic acid (HBV-DNA) in serum and hepatitis B core antigen (HBcAg) in liver. HBV-DNA in serum was assayed by the spot hybridization technique, and HBcAg in the liver was investigated by the peroxidase anti-peroxidase method. Among the parameters showing active replication of HBV, serum HBeAg, serum HBV-DNA and intrahepatic HBcAg were found in 27 (60%), 27 (60%) and in 22 (48.9%) of 45 HBsAg carriers, respectively. The presence of serum HBV-DNA and of intrahepatic HBcAg in HBeAg positive cases and the absence of serum HBV-DNA and of intrahepatic HBcAg in anti-HBe positive cases was the rule with few disparate cases among those with chronic liver disease. These parameters were not useful in predicting the histology on liver biopsy. The activity of hepatic inflammation in the HBsAg chronic carriers assessed by serum alanine aminotransferase level closely paralleled HBV-DNA in serum but not HBeAg in serum, HBcAg in liver or histologic picture on biopsy. HBV-DNA may be the most sensitive parameter of replication of hepatitis B virus and of the activity of inflammation in the liver.

Adolescent↗