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Biomedical subjects

H Ezaki

Publications and source records attributed to H Ezaki.

At least 37 records · Page 2Linked to original sources
PubMed1989

Calcium-activated neutral protease inhibitor (E-64c) and reperfusion for experimental myocardial infarction.

We examined the efficacy of the combination of coronary reperfusion and calcium-activated neutral protease (CANP) inhibitor (E-64c) for the treatment of acute myocardial infarction in dogs. In 34 dogs, the left anterior descending artery (LAD) was occluded and reperfused after 1 hour (Groups A and B). In the remaining 49 dogs, the LAD was ligated (Groups C and D). E-64c (100 mg/kg, Groups A and C) or vehicle (Groups B and D) was injected intravenously before and after the coronary occlusion or ligation. After 24 hours the hearts were removed. The proportion of the infarct size in the LAD perfusing area (risk zone) in Group A was 47.3 +/- 9.7%, significantly lower than in Group C (54.8 +/- 8.2%, p less than 0.05) or Group D (58.7 +/- 10.0%, p less than 0.01). There was a significant difference between Group B (52.9 +/- 8.6%) and Group D as well (p less than 0.05). The effects of reperfusion (p = 0.0016) and E-64c (p = 0.0226) per se on infarct size were significant, but the combination of reperfusion and E-64c was not additive. The decrease in CPK activity in the risk zone was significantly lower in the reperfused group (p = 0.0001). The mCANP activity was higher in the border zone and lower in the infarct zone. The trend in the mu CANP activity was similar to that of mCANP. Thus, treatment with a CANP inhibitor in the early phase of acute myocardial infarction may be marginally beneficial in combination with reperfusion.

Animals↗
PubMed1989

[Clinical evaluation of the prehospital phase of acute myocardial infarction in the elderly].

In order to clarify the clinical characteristics of the prehospital phase of acute myocardial infarction (AMI) in the elderly, we studied 92 elderly (65 years old or more) and 41 younger patients with first AMI. Fifty eight elderly (63.1%) and 30 younger (72.7%) patients had typical symptoms such as chest pain at onset. There were 5 elderly cases who had no symptom, although all of the younger had some symptoms at onset. More than 70% of the younger cases developed their symptoms either between 6 am and noon or between 6 pm and midnight, whereas the elderly showed no such tendency. Intervals between the onset of symptoms and hospital admission (admission time) averaged 6.8 hours (hr) in the younger and 7.7 hr in the elderly. Approximately one half of the elderly and a quarter of the younger showed admission time more than 6 hr, respectively. Elderly cases with atypical symptoms tended to have a longer admission time than younger cases (7.2 vs 3.1 hr), although there was no significant difference between the elderly and the younger with typical symptoms (8.0 vs 7.9 hr). Younger patients with heart failure had significantly shorter admission time than those without heart failure (3.6 vs 8.6 hr). However, the elderly with heart failure showed a prolonged admission time (6.1 hr). Although there was no difference on admission time between survivors and non-survivors within 28 days after admission in the elderly (7.5 vs 8.4 hr), the elderly non-survivors with atypical symptoms had the longest admission time (13.0 hr).(ABSTRACT TRUNCATED AT 250 WORDS)

Age Factors↗
PubMed1988

Clinical evaluation of the plasma levels of immunoreactive atrial natriuretic peptide in elderly patients with heart diseases.

Plasma levels of immunoreactive atrial natriuretic peptide (ANP) were estimated in 69 elderly patients over 60 years of age (mean 76.4 years) with or without heart diseases and in ten young, healthy volunteers (mean 33.0 years) to evaluate the clinical significance of ANP in the elderly. Plasma ANP levels in nine patients without heart diseases were significantly (P less than .01) higher than in the ten young, healthy subjects (mean +/- SD, 46.0 +/- 22.0 vs 22.1 +/- 6.3 pg/mL) and a significant positive correlation was observed between ANP level and age in these subjects (r = 0.60, P less than 0.01). Plasma ANP levels in 60 patients with heart diseases (158.4 +/- 158.5 pg/mL) were significantly (P less than 0.05) greater than in nine patients without heart diseases. Plasma ANP levels in patients with congestive heart failure or atrial fibrillation were 285.8 +/- 185.2 or 223.0 +/- 185.9 pg/mL, respectively; each of these values was significantly (P less than 0.01) higher than in patients without heart diseases. In three patients with paroxysmal atrial fibrillation, plasma ANP levels during atrial fibrillation were three times greater than when atrial fibrillation returned to normal sinus rhythm (377.3 +/- 78.5 vs 101.1 +/- 68.5 pg/mL). These results indicate that plasma ANP levels increase with advancing age, and that increased ANP levels are associated with various heart diseases in elderly subjects, possibly through stretch of the atrial wall.

Adult↗
PubMed1987

Comparison of enzymatic, anatomic and electrocardiographic estimates of myocardial infarct size in man.

Myocardial infarct size is definitely related to cardiac function and prognosis. For a critical evaluation of infarct size estimation methods, we weighed infarcted myocardium from 44 autopsy cases (24 men and 20 women, mean age of 76.8 yr.), and compared the weight with the peak value of serum CPK activity (peak-CPK), the peak value of serum CPKMB isoenzyme activity (peak-CPKMB), the total CPK release (sigma CPK), and the QRS scoring system in the standard 12-lead electrocardiogram (ECG) modified by Wagner et al.. The mean infarcted myocardial weight (MI weight) of the 44 cases was 38.4 g. The mean value of the peak-CPK, peak-CPKMB, and sigma CPK were 2487, 221, and 4597 IU/ml, respectively, and the mean QRS point score was 7.2. The interval between serial CPK determination and ECG recording or autopsy averaged 130.1 or 52.4 days, respectively. There were significant (p less than 0.01) correlations between the MI weight and peak-CPK (r = 0.63, n = 17), peak-CPKMB (r = 0.79, n = 17), sigma CPK (r = 0.72, n = 11), and the QRS scoring system (r = 0.64, n = 39), respectively. Especially in cases of non-transmural myocardial infarction, the QRS scoring system showed a high correlation with MI weight (r = 0.82, n = 11, p less than 0.01). We conclude that the peak-CPK, peak-CPKMB, sigma CPK, and the QRS scoring system are useful for the estimation of myocardial infarct size.

Adult↗
PubMed1987

A histopathologic study of the conduction system in an elderly patient with partial atrial standstill.

Electrophysiologic and histopathologic studies were performed on an 83-year-old man with partial atrial standstill. In the electrophysiologic study, no atrial electrical activity was recorded in the right atrium, but f waves were seen in the coronary sinus electrogram. Although the high right atrium and the atrial septum could not be activated by electrical stimuli of up to 10 V, the low atrium could be stimulated. The pathologic examination showed that there was extensive fatty infiltration into the sinus node and fibrosis in the atrial muscle. In the low right atrium, the musculature was partially preserved.

Aged↗
PubMed1987

Incidence of female breast cancer among atomic bomb survivors, Hiroshima and Nagasaki, 1950-1980.

Ascertainment of breast cancer incidence among the cohort of the RERF Life Span Study extended sample identified 574 breast cancers among 564 cases diagnosed during 1950-1980 of which 412 cancers were reviewed microscopically. There were no dose-dependent differences with respect to diagnostic certainty or histological type. As in previous studies, the dose response appeared to be roughly linear and did not differ between the two cities. The most remarkable new finding was the emergence of a radiation-related excess among women under 10 years of age at exposure. The risk of radiogenic breast cancer appears to decrease with increasing age at exposure, whether expressed in relative or absolute terms. These results suggest that exposure of female breast tissue to ionizing radiation at any time during the first four decades of life, even during the premature stage, can cause breast cancer later in life, and that the length of time that tumor promoters such as endogenous hormones operate following exposure has an important influence on the development of radiation-induced breast cancer. An unresolved question is whether breast cancer risk is increased by radiation exposure at ages older than 40.

Age Factors↗
PubMed1986

Comparison of radiosensitivities of human autologous normal and neoplastic thyroid epithelial cells.

Studies were conducted to examine differences between the radiosensitivities of normal and neoplastic epithelial cells of the human thyroid. Freshly excised thyroid tissues from the tumours of eight patients with papillary carcinoma (PC) and five with follicular adenoma (FA) were cultured in vitro separately from normal thyroid tissue obtained from the surgical margins of the same patients. Plating efficiency of unirradiated control tissue was lower, on average for tumour tissue compared with normal tissue. Radiosensitivity, measured by the 37% inactivation dose D0, was greater for carcinoma tissue than for normal tissue in seven out of eight PC cases. Adenomatous tissue was less radiosensitive than normal tissue in four out of five FA cases. This is the first report comparing the radiosensitivity of autologous normal and abnormal epithelial tissue from the human thyroid.

Cell Survival↗
PubMed1985

Survival of human normal thyroid cells after X-ray irradiation.

Normal thyroid cells from 25 individuals treated surgically for malignant or benign thyroid tumour were cultured in vitro and radiation induced cytotoxicity was studied. The mean lethal dose (Do), quasi-threshold (Dq), and extrapolation number (n) of survival curves of actively dividing thyroid cells assayed by colony formation were estimated to be 92.9 +/- 2.8 cGy (rad), 58.1 +/- 6.9 cGy and 2.0 +/- 0.1, respectively (average for 25 individuals +/- standard error). These results suggest that proliferating human thyroid cells are more sensitive to X-rays than most other nonhaematologic mammalian cells in similar assays. Cell survival was not significantly affected by sex, age, disease or exposure to atomic bomb radiation of the cell donor. However, the number of samples currently available is too small for definite conclusions in this regard.

Adolescent↗
PubMed1985

A case of ruptured hepatoma followed by elastase-induced disseminated intravascular coagulation.

In the present study, the first case of ruptured hepatoma followed by disseminated intravascular coagulation is reported. An elastase-like enzyme which possessed elastolytic and caseinolytic activities was confirmed from patient plasma. On the other hand, no elastase activity was detected in the plasma of patients with hepatitis, liver cirrhosis or hepatoma without disseminated intravascular coagulation. The patient plasma did not possess H-D-Val-Leu-Lys-p-nitroanilide hydrochloride, succinyl-L-alanyl-L-alanyl-p-nitroanilide, and pyro-Glu-Pro-Val-p-nitroanilide amidolytic activities. However, when chromatographed on Sephadex G-200, the presence of low-molecular weight plasminogen was confirmed. Its molecular weight was approximately 52,000. A slight decrease of alpha 2-plasmin inhibitor was noted, but no decrease of alpha 2-macroglobulin was detected.

Aged↗
PubMed1985

[Interaction of proteases and their inhibitors in the pathogenesis of pancreatitis].

It was confirmed that esterolytic activity was significantly elevated in plasma of patients with acute pancreatitis, which correlated better with the stage of the disease than serum amylase level. Using the several column chromatography procedures, pancreatic kallikrein, trypsin and pancreatic elastase were separated and purified from alpha 2-macroglobulin (alpha 2-M) fractions of patients plasma with acute pancreatitis. From this this result, it was confirmed that kallikrein was liberated into the blood stream from the pancreas during attacks of acute pancreatitis and the liberated kallikrein combined with alpha 2-M. Furthermore, the coexistence of trypsin is required for the complex formation of alpha 2-M and pancreatic kallikrein. It was speculated that alpha 2-M might be decomposed by the excessive amount of elastase, and consequently, might release all of its combining enzymes into the blood stream. In the present study, the activation mechanism of fibrinolytic enzyme system in plasma by human pancreatic elastase was investigated. Elastase not only converted the co-existing plasminogen to low molecular weight plasminogen which could be easily activated by the activators, but also inhibited alpha 2-M and alpha 2-plasmin inhibitor, and consequently, induced the activation of the fibrinolytic enzyme system in plasma. Furthermore, it was also confirmed that elastase could activate plasma kallikreinogen to kallikrein.

Acute Disease↗