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Biomedical subjects

A Shibata

Publications and source records attributed to A Shibata.

At least 361 records · Page 20Linked to original sources
PubMed1990

Fibrinolysis and fibrinogenolysis in liver disease.

Patients with liver disease frequently have hemostatic abnormalities which include accelerated fibrinolysis. In order to assess the fibrinolytic state in liver disease, plasma levels of fibrinogenolysis products (FgDP), fibrinolysis products (FbDP), and fibrinogenolysis plus fibrinolysis products (TDP) were measured with newly developed enzyme-linked immunosorbent assays based on monoclonal antibodies in 36 patients with liver disease (six patients with acute hepatitis, seven with chronic hepatitis, ten with liver cirrhosis, 11 with hepatocellular carcinoma, and two with intrahepatic cholestasis). As compared with healthy subjects, mean plasma levels of FbDP (1,083 +/- SD 1,254 vs. 236 +/- 100 ng/ml, P = 0.005) and TDP (1,773 +/- 1,814 vs. 669 +/- 212 ng/ml, P = 0.001) were significantly elevated in patients with liver disease, whereas FgDP was normal (389 +/- 202 vs. 396 +/- 132 ng/ml, P = 0.87). Plasma FbDP correlated very well with TDP (r = 0.986, P less than 0.00001) in liver disease. In addition, FbDP and TDP but not FgDP correlated with plasma concentrations of thrombin-antithrombin III complex. When plotted by the disease categories, the magnitude of elevations of FbDP and TDP was the most prominent in acute hepatitis followed by hepatocellular carcinoma. These findings indicate that activation of fibrinolysis occurs following thrombin generation, but increased primary fibrinogenolysis is rare in liver disease.

Antithrombin III↗
PubMed1990

Exposure-response relationships between woodworking, smoking or passive smoking, and squamous cell neoplasms of the maxillary sinus.

A case-control study of squamous cell neoplasms of the maxillary sinus was performed in Hokkaido during 1982-86, with 169 cases and 338 controls matched for sex, age, and residence. The data were analyzed by a stepwise forward-selection method based on a conditional logistic-regression model without interaction terms, log-likelihood ratio tests, and chi-square tests for trend. Statistically significant linear trends were observed for associations between the risk of squamous-cell maxillary-sinus neoplasms and the duration of woodworking among men, the daily or lifetime amount of smoking among men, and the number of smokers in the household as an index of domestic exposure to cigarette smoke among women.

Adult↗
PubMed1990

A novel experimental model of giant cell myocarditis induced in rats by immunization with cardiac myosin fraction.

It is suspected that autoimmune disease processes are involved in the pathogenesis of a part of giant cell myocarditis. However, evidence for autoimmunity has rarely been demonstrated in clinical investigations. In this study, we have demonstrated a new animal model of autoimmune myocarditis characterized by the appearance of multinucleated giant cells. Lewis rats were immunized twice with human cardiac myosin fraction in complete Freund's adjuvant. Cardiac myosin fraction was prepared from the ventricular muscle of human hearts. Three weeks after the first immunization, acute and severe myocarditis was elicited in all rats. This myocarditis was characterized by massive pericardial effusion, enlargement of the heart, and gray discoloration of the cardiac muscle. Microscopically, there was marked cellular infiltration consisting of mononuclear cells, neutrophils, fibroblasts, and a considerable number of multinucleated giant cells. Extensive myocardial necrosis was also present. The heart weights increased from the third week to the fourth week and then gradually decreased. The titer of anti-myosin antibodies began to elevate from the second week and remained high until the sixth week. In the sixth week, inflammation became smoldering and the multinucleated giant cells disappeared. These findings indicate that the cardiac myosin fraction contains myocarditogenic antigen and that giant cell myocarditis can be induced by autoimmune involvement. To our knowledge, this is the first report of experimental giant cell myocarditis, which is closely similar to human giant cell myocarditis in its histology and clinical course.

Animals↗
PubMed1990

Changes in serum concentrations of beta-carotene and changes in the dietary intake frequency of green-yellow vegetables among healthy male inhabitants of Japan.

Serum levels of beta-carotene among 147 healthy male inhabitants were measured twice with an interval of one year in order to determine the relationship between changes in serum beta-carotene levels and changes in the dietary intake of green-yellow vegetables. A positive association was found to exist between changes in the intake frequency of green-yellow vegetables and changes in serum beta-carotene levels, whereas changes in alcohol intake and smoking were discovered to be negatively associated with changes in serum beta-carotene levels. The positive association between changes in the intake frequency of green-yellow vegetables and changes in serum beta-carotene levels was preserved after adjustment for these negative factors.

Adult↗
PubMed1990

Combined 17 alpha-hydroxylase/17,20-lyase deficiency due to a 7-basepair duplication in the N-terminal region of the cytochrome P45017 alpha (CYP17) gene.

17 alpha-Hydroxylase deficiency is characterized by defects in either or both of the 17 alpha-hydroxylase/17,20-lyase activities. We have elucidated the molecular basis of the combined deficiency of these activities in a Japanese female who is genotypically male and the child of a consanguineous marriage. The complete exonic sequence of the patient's CYP17 (P45017 alpha) gene revealed a seven-basepair duplication (GCGCACA) in exon 2 which leads to a frame shift and, subsequently, a premature stop codon. Because this stop codon occurs N-terminal to the heme-binding sequence, the presence of this mutation leads to the absence of a functional P45017 alpha-protein in adrenal cortex and testis. This, in turn, leads to an absence of sex steroids and excessive secretion of steroids with mineralocorticoid activity and, consequently, female external genitalia and hypertension in this 46XY patient.

Adolescent↗
PubMed1990

Requirements of non-pharmacologic interventions in the treatment of recurrent sustained ventricular tachycardia.

Sixty-five patients (pts) with sustained ventricular tachycardia (VT) and 1 patient with symptomatic nonsustained VT were included in this study. Of these, 5 had died before electrophysiologic study (EPS) or determination of effective antiarrhythmic drugs. Inducibility of VT by our protocol varied from 69 to 100% according to underlying diseases. Drug efficacy was evaluated by using conventional drugs in all and using flecainide and amiodarone in some. However, more than 50% of pts with inducible VT were found to be resistant to pharmacological therapy. Fourteen of 26 pts with drug-refractory VT, underwent surgical therapy. In all pts, the site of VT origin was determined and VT was either eradicated or clinically controlled in 86% of the patients. Catheter ablation was tried in 9 pts at the earliest activation site of VT or at the site where pace-mapping produced the best result in configuration in the QRS complex as the clinical VT. Prophylactic effect was confirmed in 60% but VT recurred in 3 pts. These VT became responsive to anti-arrhythmic drugs in 2 pts. In thirteen pts who died suddenly during the follow up period, none had adequate antiarrhythmic drugs. One patient died after operation because of residual VT among four different QRS morphologies found preoperatively. In conclusion, the success rate antiarrhythmic drug prophylaxis against VT induction or recurrence did not exceed 50%, therefore non-pharmacological interventions such as surgery or catheter ablation may be required.

Adolescent↗
PubMed1990

Conduction through the reentrant circuit in recurrent sustained ventricular tachycardia evaluated by use of transient entrainment.

Using transient entrainment, the effect of the paced cycle length on the conduction through the reentrant circuit was assessed in recurrent sustained ventricular tachycardia (VT). Fourteen patients were included in the present study and their VTs were paced at multiple cycle lengths while the criteria of entrainment were confirmed at each paced cycle length. Then, the effect of the paced cycle length upon the conduction time, which was evaluated by the measurement of the time interval from stimulus to the entrained electrogram, was analyzed. In the overdrive pacings of VT, 3 response patterns in conduction time were observed: an increasing pattern (n = 8), a flat pattern (n = 5) and a decreasing pattern (n = 1) while the local conduction time outside the reentrant circuit remained unchanged at comparable paced cycle lengths. A decremental property is the likely mechanism responsible for the paced cycle length-dependent prolongation. As for the flat pattern, the existence of a fully excitable gap may be responsible. A paced cycle length related change in the reentrant circuit may account for the decreasing pattern. By using transient entrainment, the electrophysiological characteristics of the reentrant circuit can be evaluated and the information so gathered may be valuable in analyzing the action of antiarrhythmic drugs on the slow pathway.

Adolescent↗
PubMed1990

Clinical characteristics and possible role of coronary artery spasm in syncope and/or aborted sudden death.

We investigated the clinical and pathophysiologic characteristics in patients with vasospastic angina who developed syncope and/or experienced aborted sudden death (SD). Vasospastic angina was diagnosed using the methylergonovine test. Syncope was found in 32 (10.4%) patients among 309 who were admitted to our institute in a one-year period. The most frequent cause of syncope was ventricular tachycardia which was found in 10 (31.2%) of the 32 patients. The next important cause of syncope was vasospastic angina which was found in 7 patients (21.8%). Among the 7 patients with vasospastic angina who experienced one or more syncopal episodes, there were 3 patients with aborted SD, 3 with syncope and one with shock. Cardiovascular collapse was observed in 4. Interior wall ischemia was found in 5 and anterior wall ischemia in 2 during the methylergonovine test. None of the 7 patients had significant coronary stenosis. Two patients had no prodromal symptom such as chest pain. Our results suggest that coronary artery spasm may be one of the most frequent cardiovascular diseases that causes syncope which is not always accompanied by a prodromal symptom. Therefore, coronary spasm should be distinguished in patients with unexplained syncope or aborted SD.

Coronary Angiography↗
PubMed1990

Electrical catheter ablation for drug-refractory sustained ventricular tachycardia with old myocardial infarction--a case report.

We performed electrical catheter ablation (ECA) in a patient who had old myocardial infarction and drug-refractory sustained ventricular tachycardia (VT). ECA using 100J to the earliest activation site and the pace-mapping site failed to prevent the VT. ECA using the same energy to the site at which mid-diastolic potential was recorded during tachycardia could successfully ablate the VT. Therefore the site of energy delivery was important in VT with old myocardial infarction.

Aged↗
PubMed1990

Ventricular tachycardia with two possible exits from one re-entrant circuit.

A case of sustained ventricular tachycardia (VT) with two possible exits from one re-entrant circuit is described in this paper. The patient was a 27-year-old female who had undergone corrective surgery for tetralogy of Fallot at the age of 8, and developed VT of distinctly different QRS configurations. The exit of one VT was at the right ventricular (RV) outflow tract and the other at the RV apex as determined by endocardial and pace-mapping. Continuous and split activities were observed at the RV outflow tract during both types of VT. One VT was entrained by rapid pacings, and the causal mechanism was thought to be re-entry and common re-entrant circuit was established for two QRS configurations of VTs. A discrepancy was observed between the site of the earliest activation and the site of the pace-mapping which resulted in QRS configuration of VT of the RV apex origin. The findings in this paper should be considered when contemplating aggressive therapy such as electrical ablation.

Adult↗
PubMed1990

Family history of cancer and mortality among patients gastrectomized because of benign gastric diseases.

A preliminary result from a cohort study on the association of a family history of cancer with mortality is discussed in this paper. Among 2200 patients (1912 males and 288 females) gastrectomized because of benign gastric diseases, 274 male patients, and 40 female patients had a family history of cancer. During 2750 person-years of observation, 22 patients with the family history of cancer were found to be dead and 111 patients without the family history died during 17,527 person-years, giving a relative risk of 1.26 (not significant). We focused on the male subjects that were followed up for more than 10 years; however, the observed/expected ratio of cancer deaths for subjects with a family history of cancer was about four times higher than that for those without family history. Since case-control studies on family history are vulnerable to biased recall and interchangeability of cases, more cohort studies like the present study should be conducted to assess the association of the family history of cancer.

Case-Control Studies↗
PubMed1990

Glomerular filtration response to acute loading with protein from different sources in healthy volunteers and diabetic patients.

To evaluate the effects of acute protein loading on the glomerular filtration rate, albumin excretion rate and concentration of plasma amino acids, ten healthy volunteers and six type 2 diabetic patients with normoalbuminuria were studied before and after eating 0.7 g/kg body weight of tuna fish, boiled egg white, cheese or tofu (bean curd) on separate days. Furthermore, to study the possible role of glucagon, growth hormone, atrial natriuretic peptide and kallikrein in the responses of glomerular filtration rate to protein, these substances were measured before and after ingestion of tuna fish or egg white in six healthy volunteers. In healthy subjects, glomerular filtration rate increased significantly (p less than 0.01) from 98.1 +/- 4.2 ml/min during the baseline period to 129.9 +/- 6.6 ml/min after ingestion of tuna fish. No significant differences were seen between glomerular filtration rate before and after ingestion of egg white, cheese or bean curd. No significant differences were observed between the baseline albumin excretion rate and that after loading with any of the four kinds of protein. Plasma concentrations of alanine, glycine and arginine (amino acids known to induce glomerular hyperfiltration) increased to a greater degree after ingestion of tuna fish than after administration of the other meals. Diabetic subjects and healthy volunteers had similar responses. Plasma glucagon and growth hormone concentrations increased after ingestion of the tuna fish meal or egg white. Plasma atrial natriuretic peptide concentration and urinary kallikrein excretion were unaffected by ingestion of these two kinds of protein. These findings suggest that responses of glomerular filtration rate to acute protein loading may differ depending on the protein ingested, and that these responses may not be directly induced by glucagon, growth hormone, atrial natriuretic peptide or kallikrein.

Adult↗
PubMed1990

Smoking habits among senior high school students and related factors.

The present study was conducted to provide baseline data for an anti-smoking educational program. Nineteen public senior high schools in a prefecture in Kyushu, Japan, participated in the study. In July 1982, unsigned self-administered questionnaires on smoking habits were answered by 4689 students--3088 males and 1601 females--during a homeroom under the supervision of their class teacher. The proportions of students who admitted that they had smoked cigarettes were 45.9% for males and 18.2% for females at the ordinary schools, and 78.1% for males at vocational schools. Eleven to twenty percent of male students had already smoked cigarettes in primary school. More male students in vocational schools had smoked than either male or female students in ordinary schools. Over 40% of vocational school students were regular smokers, in contrast to 11.8% for males and 3.4% for females at ordinary schools. It was also noted that the younger the students, the earlier the age at which they had smoked their first cigarette. The incidence of smoking at the primary school age appeared to be correlated with the incidence of smoking by a family member and at high school age with the incidence of smoking by a friend. Spending money and a friend who smoked were strongly associated with current smoking status of high school students, while parental smoking had a weak association. These results suggest the need for anti-smoking education beginning in a lower grade in primary school.

Adolescent↗
PubMed1990

In vitro sensitivity of human hematopoietic progenitor cells to hyperthermia: critical temperature for cells to survive and its application to in vitro purging.

Normal tissue toxicity is a major concern in cancer therapy. Since the hyperthermic killing of normal human hematopoietic progenitor cells including multilineage progenitor cells (CFU-mix) other than committed granulocyte-macrophage progenitor cells (CFU-GM) is not known, we have studied the thermal sensitivity of various types of human hematopoietic progenitor cells: early and late erythroid progenitors (CFU-E and BFU-E), CFU-GM and CFU-mix using semisolid clonogenic assays. When these progenitor cells were exposed at 42-44 degrees C for 2 h, their thermal sensitivity always appeared to be in the order of CFU-E greater than BFU-E greater than CFU-GM greater than CFU-mix; the CFU-mix was the most tolerant to heat damage. In addition, the survival of human hematopoietic progenitor cells decreased exponentially in exposure time- and temperature-dependent manner. At 44 degrees C human hematopoietic progenitor cells including CFU-mix dropped dramatically in number and therefore were unable to form colonies in vitro after exposure for 2 h. This suggests that 44 degrees C may be the critical temperature for the CFU-mix to survive in vitro. Thus temperatures selected for hyperthermia used to purge residual leukemic cells in remission marrow grafts should be 43 degrees C or lower.

Cell Survival↗
PubMed1990

An ultrastructural study on arrhythmogenic right ventricular dysplasia with special reference to lipid droplets.

Myocardial tissues in arrhythmogenic-right ventricular dysplasia (ARVD), which were surgically resected from the site of origin of ventricular tachycardia (VT), were investigated optically and electron-microscopically. The site of origin was found to be occupied by an abundance of adipose cells. In the marginal zone, lipid droplets were obviously increased in count in the cytoplasm of both myocytes and blood capillary-endothelium, rather more than in distant areas. Lipid droplets in the endothelial cells also occurred at a higher frequency in the ARVD group than in any other myocardial disease showing VT. A mechanism which increases lipid droplets in the cytoplasm of cardiomyocytes and endothelial cells operates at the VT origin site in ARVD. Intraendothelial lipids may be an important diagnostic finding in the histology of ARVD.

Adult↗
PubMed1990

[An echocardiographic study of alcoholic cardiomyopathy after total abstinence].

Left ventricular function of alcoholic cardiomyopathy with congestive heart failure was investigated by echocardiography during total abstinence for six months. In five of 13 cases, left ventricular ejection fraction (LVEF) was normalized to 55% or more and left ventricular end-diastolic dimension (LVEDd) was reduced to 5.7 cm or less during the study. In the remaining eight patients, no improvement was observed. In the responsive group, two patients showed an increase of LVEF and a reduction of LVEDd simultaneously, but three showed an earlier change in LVEDd. This normalization of LVEF and LVEDd was recognized from three to 12 weeks after abstinence. No significant differences were detected between the responsive and non-responsive groups concerning their age, daily intake of alcohol and period of drinking, NYHA cardiac functional class, the period of experiencing cardiac symptoms and the cardiothoracic ratio by chest radiography. The ratio of left ventricular radius to wall thickness (R/Th) remained 2.9 or less in all of the responsive group, but seven of eight in the non-responsive group showed 2.9 or more. Left atrial dimension was reduced to the normal range except in one, but its normalization did not correlate with the change of left ventricular function. Consequently, after total abstinence from alcohol intake, both left ventricular end-diastolic dimension and ejection fraction improved rapidly, and their normalization could be highly expected. Echocardiography is very helpful in predicting the effect of total abstinence on left ventricular function in alcoholic cardiomyopathy.

Adult↗