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Biomedical subjects

Y Abe

Publications and source records attributed to Y Abe.

At least 1,063 records · Page 59Linked to original sources
PubMed1983

Effects of thyrotropin on thyroid chromatin. Enhanced sensitivity to micrococcal nuclease and increased nuclear protein phosphorylation.

Thyroid slices were incubated with or without TSH for 2 or 5 h. Nuclei were then prepared, subjected to mild digestion with micrococcal nuclease, and centrifuged at 1200 X g. The amount of DNA in 1200 X g supernatants was increased by TSH at 5 h, but not at 2 h. In parallel studies, thyroid slices were incubated with 32Pi and labeling of acid-soluble nuclear proteins was examined. TSH-dependent increases in labeling of histones H1 and H3, and of the high mobility group protein HMG 14, were observed at 2 h; however, there were no apparent changes in TSH-dependent labeling between 2 and 5 h, in nuclease-sensitive or in bulk chromatin. These results suggest that the observed TSH-dependent changes in the micrococcal nuclease-sensitivity of thyroid nuclear chromatin were not induced directly by changes in the phosphorylation of the histones or HMG 14.

Animals↗
PubMed1983

Two distinct types of non-A, non-B hepatitis in a cardiovascular surgical unit.

The incidence of non-A, non-B hepatitis in a cardiovascular surgical unit was examined among the 204 patients who received blood transfusion and extracorporeal circulation while undergoing open heart surgery during April 1979 to December 1981. Among 115 adult patients (20 to 69 years old) 46 (43%) developed non-A, non-B hepatitis, whereas the incidence in younger patients (1 to 19 years old) was much lower (21.8%, 19 out of 89). When monthly incidence was examined during the study period, two nosocomial epidemics, the first during September 1979 to February 1980 and second during October 1980 to January 1981, were found. When clinical features such as maximum ALT level and the proportion of icterus were examined, the features of the above two epidemics were taken to be different from those consistently observed through the study period. The epidemic type hepatitis not only resulted in more severe clinical features than the nonepidemic type, but the sera of the former contained immune complexes at a higher rate (80%) than did the latter (7.6%).

Adolescent↗
PubMed1983

A risk index for the prediction of the incidence of non-A, non-B posttransfusion hepatitis in open-heart surgery patients.

Risk factors related to the occurrence of non-A, non-B posttransfusion hepatitis (PTH) were statistically analyzed in 204 patients (115 adults and 89 children) who received blood transfusion and extracorporeal circulation during open-heart surgery. The PTH incidence, irrespective of age or body weight, was affected by both transfusion volume and circulation time, ie, the incidence increased cumulatively with the increment of these two variables. Based upon such statistical analysis, a "PTH-risk index," from which one can objectively predict the probability of PTH, was devised by the summation of standardized transfusion volumes (Vs) and circulation time (Ts). As a result, a high correlation between the obtained PTH-risk index and actual incidence was found. The obtained straight regression line between PTH-risk index and the actual incidence rate enabled us to predict the incidence of PTH in open-heart surgery patients.

Adolescent↗
PubMed1983

An antigen/antibody system specific for an epidemic non-A, non-B hepatitis in patients of a cardiovascular surgical unit.

The antigen/antibody systems specific for non-A, non-B hepatitis (NANB) were studied using urine samples as the antigen source and sera for the antibody source. Two immunologically distinct systems, SO-antigen/anti-SO and MI-antigen/anti-MI were discovered. This paper deals chiefly with the characterization of the SO-antigen, which was associated with an epidemic-type non-A, non-B hepatitis found during September 1979 to February 1980 (first outbreak) and October 1980 to January 1981 (second outbreak) in the Cardiovascular Surgical Unit of Tohoku University Hospital. All patients who developed non-A, non-B hepatitis during the first and second epidemic periods had SO-antigen in their urine (24 out of 24). After the epidemic, however, the detection rate of SO-antigen gradually decreased among patients in the same unit, although posttransfusion non-A, non-B hepatitis continued to be found. The final detection of SO-antigen occurred at or just after the elevation of alanine aminotransferase (ALT) levels during the episode of hepatitis and persisted in most cases throughout the elevated period. Anti-SO antibody was detected relatively late (eight months after blood transfusion, in most cases) and apparently persisted longer than five years. The immunological and physicochemical properties of SO-antigen were also studied. It appeared to be neither a plasma protein nor a liver tissue component when the cross-reactivity of SO-antigen was examined by the immunodiffusion method. Absorption with insolubilized human serum and liver tissues failed to affect the anti-SO antibody activity. The molecular weight of SO-antigen was estimated to be 250,000, the sedimentation coefficient to be 11.0 S, and the buoyant density in CsCl to be 1.215 g/cm3. Electron microscopy showed that the SO-antigen corresponded with uniform particles with a mean diameter of 11 nm. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis of SO-antigen revealed only a single protein band corresponding to molecular weight 38,000.

Antibodies, Viral↗
PubMed1983

Experimental pancreas imaging study with 13N-glutamate using positron computer tomography.

Accumulation of 13N-L-glutamate in the pancreas was experimentally evaluated by tissue distribution studies and by positron computer tomography imaging studies. The pancreas and salivary gland of Donryu rats exhibited a high rate of 13N-glutamate uptake. The percent administered dose/g of pancreas was 3.8 at 20 min, 4.4 at 30 min after injection, and the pancreas to liver ratio was 1.9 and 2.5, respectively. The same results were obtained with Golden hamsters. The role of the feeding protocols was studied to optimize the technique. The fasting group showed a significantly higher uptake in the pancreas than in the free feeding group. The uptake in the fasting followed by a high protein meal group was higher than fasting only group, but the difference was not significant. Positron emission tomography of a miniature-pig with 13N-glutamate showed a clear image of the pancreas with the highest activity. It was concluded that 13N-glutamate was quite useful in positron imaging of the pancreas.

Animals↗
PubMed1983

Studies on 18F-labeled pyrimidines. Tumor uptakes of 18F-5-fluorouracil, 18F-5-fluorouridine, and 18F-5-fluorodeoxyuridine in animals.

Three 18F-labeled pyrimidines, 18F-5-fluorouridine (18F-5-FUR), 18F-5-fluorouracil (18F-5-FU), and 18F-5-fluorodeoxyuridine (18F-5-FdUR), were examined regarding tissue distribution and tumor uptake in ascitic hepatoma AH109A-bearing rats. The differential absorption ratios of tumors of 18F-5-FUR, 18F-5-FU, and 18F-5-FdUR were 0.75 +/- 0.21, 0.92 +/- 0.15, and 0.96 +/- 0.24 at 30 min, and 0.37 +/- 0.09, 0.64 +/- 0.34, and 0.60 +/- 0.17 at 120 min, respectively. The tumor-to-organ ratios obtained with three radiopharmaceuticals, especially with blood, heart, lung, muscle, and brain were high and these ratios increased with time. The tumor-to-organ ratios obtained with 18F-5-FdUR were always 1.3-4 times higher than 18F-5-FU and 18F-5-FUR. We concluded that 18F-5-FdUR was a suitable radiopharmaceutical for tumor imaging. Positron emission tomography of a rabbit tumor located on the chest with 18F-5-FdUR clearly showed the tumor within 1 h.

Animals↗
PubMed1983

Combination chemotherapy enhances survival of patients with unresectable gastric cancer.

Of 177 Japanese patients with a gastric cancer which could not be resected and seen at our institution during the period from 1964 to 1979, 153 were investigated with regard to the efficacy of anticancer agents, in terms of prolongation of life. The average survival time was 23 weeks in the combination chemotherapy group (57 cases), 17 weeks in the single drug chemotherapy group (42 cases) and 13 weeks in no chemotherapy group (54 cases). Three and 6 month survival rates in the overall patients were 57.1 per cent and 16.7 per cent for single drug chemotherapy group, and 37.0 per cent and 11.1 per cent for no chemotherapy group, while in the combination chemotherapy group, the rates were higher at 64.9 per cent and 29.8 per cent, respectively (combination chemotherapy vs. no chemotherapy group, p less than 0.05). In patients with peritoneal dissemination, hepatic metastasis and carcinomatous ascites, there was a significant difference in survival rates between those prescribed combination chemotherapy and those given no chemotherapy (p less than 0.05). Of 57 in the combination chemotherapy group, 6 and 9 month survival rates were 45.5 per cent and 22.7 per cent in the postoperative long-term cancer chemotherapy (PLCC) group (22 cases), such being higher than other combination chemotherapy group (35 cases), 22.9 per cent and 11.4 per cent, respectively. There was a significant difference in the survival rates between the two groups (p less than 0.05).

Adult↗
PubMed1983

Correlations between regional cerebral blood flow and age-related brain atrophy: a quantitative study with computed tomography and the xenon-133 inhalation method.

One hundred and two subjects (40 men and 62 women) neither having a history of neurologic deficits nor showing organic lesions on computed tomographic examination of the brain were studied. Ages of the subjects ranged from 26 to 81 years. Regional cerebral blood flow was measured by the xenon-133 inhalation method, and the volume percentage of brain with respect to the cranial cavity (craniocerebral index) was calculated by means of computer programs. Regional cerebral blood flow was computed as the fast component of two-compartmental analysis and as the initial slope index value. The percentage of each subject's craniocerebral index in relation to the standard for subjects with non-atrophied brains (brain volume index) was calculated as the indicator of brain atrophy. Both the mean brain fast component values and the mean brain initial slope index values correlated closely with the brain volume index in the elderly (r = 0.60, r = 0.62; P less than 0.0001 in each correlation coefficient). Low cerebral blood flow values coincided with loss of brain substance in the final stage of age-related brain atrophy, but not in the intermediate stage.

Adult↗
PubMed1983

Role of type 1 fimbriae in the pathogenesis of ascending urinary tract infection induced by escherichia coli in mice.

Escherichia coli mutants defective in the ability to agglutinate guinea pig erythrocytes (HA-) were isolated from a nalidixic acid-resistant derivative, 31-B, of E. coli TN 675 that produces type 1 fimbriae and induces urinary tract infection in mice fed a 5% glucose solution. All nine HA- mutants were defective not only in their ability to agglutinate Candida albicans cells and erythrocytes from various species, but also in their capacity to adhere to mouse bladder epithelial cells. None of the mutants were agglutinated by anti-type 1 fimbriae antiserum. Although most of the mutants were fimbriated when examined by electron microscopy, their fimbriae differed serologically from type 1 fimbriae. All of the mutants showed 100 to 1,000 times lower bacterial recovery from the bladder walls of mice 3 h after inoculation into the bladder and lacked urinary tract infectivity in mice. These results suggest that all of the HA- mutants are defective in type 1 fimbriae production and that type 1 fimbriae facilitate the development of urinary tract infection in mice, probably by mediating bacterial adherence to the bladder epithelial cells.

Adhesiveness↗
PubMed1983

Dynamics of cardiac output and systolic time intervals in supine and upright exercise.

Transient and steady-state responses of stroke volume (SV), heart rate (HR), cardiac output (Q), left ventricular ejection time (LVET), preejection period (PEP), and the ratio of LVET to PEP during bicycle exercises of 50 and 100 W were studied in four healthy male subjects in supine and upright postures. A computer-based system in which impedance cardiography was incorporated served to determine the above parameters on a 10-s interval basis. SV remained almost unchanged in response to exercises in a supine posture, whereas it increased significantly in an upright posture, although the individual differences among subjects were found to be large. The half-response times of variables to a step work load were determined. An approximate accordance was observed among the response times for HR, Q, and LVET/PEP. There was an inverse relationship between LVET and HR, the slope of which was found to be steeper in the supine posture than in the upright posture, reflecting the difference between the SV responses in both postures. LVET fell shortly after the cessation of exercise despite the decreasing HR. Inasmuch as the paradoxical reduction of LVET was also found in the case where SV remained unchanged in response to exercise, no changes in SV can be the cause thereof. Thus, a transient increase in ejection rate, which is due to either the increased myocardial contractility or decreased peripheral vascular resistance, may be responsible for the phenomenon.

Adult↗
PubMed1983

Effects of EDTA and verapamil on renin release in dogs.

EDTA or verapamil was infused into the renal artery of the anesthetized dog, and the effects on renin release and renal function were examined in an attempt to elucidate the role and action site of calcium ion in the renin secretory system. Both EDTA (25 mg/min) and verapamil (50 micrograms/min) increased RSR and RBF with a concomitant increase of urine flow, although there was no change in systemic arterial pressure. An infusion of verapamil in combination with ouabain produced a significant increase in RBF which was similar to that seen with verapamil alone. Urine flow and urinary excretion of electrolytes were also increased, but these changes did not differ from those seen with ouabain infusion alone. Ouabain alone did not affect RSR, but its infusion combined with verapamil resulted in a significant increase in RSR. Therefore, the effects of EDTA and verapamil on renin release may reflect the action of both drugs on the vascular component of the juxtaglomerular apparatus. If a change in calcium movement similar to the one in vascular smooth muscle occurs in the juxtaglomerular cells, the altered concentration of calcium may be considered to induce, in part, the stimulation of renin release by EDTA or verapamil.

Animals↗
PubMed1983

Effects of radiotherapy and chemotherapy on sister chromatid exchanges in peripheral lymphocytes of the patients with gynecologic cancer.

Studies were done on the influence of radiotherapy or chemotherapy on peripheral lymphocyte SCE (sister chromatid exchange) frequency in patients with gynecologic cancer. The average value of spontaneous SCE frequency in 10 patients who had received radiotherapy was 6.94 +/- 2.57 (mean +/- S.D.), which was significantly lower than the control value of 8.59 +/- 2.99 ( p less than 0.001). The rate of decline of these frequency values was negatively correlated with the irradiation dosage. In contrast, the average spontaneous SCE frequency in the patients who had received combination chemotherapy was 12.48 +/- 4.02, which was significantly higher than the control value ( p less than 0.001). The average value of MMC-induced SCE frequency in patients under chemotherapy was much the same as the control value of 26.16 +/- 5.77. That is patients under radiotherapy was 23.88 +/- 5.65, which was slightly lower than the control value. There was, however, no significant difference in the MMC-induced SCE frequency value among these 3 groups.

Choriocarcinoma↗
PubMed1983

Changes in stenosis resistance and myocardial blood flow after a brief coronary occlusion in the dog.

Stress-induced changes in the resistance due to coronary arterial stenosis of a fixed diameter and in the myocardial blood flow distal to the stenosis were investigated in the open-chest dog. Myocardial blood flow in the inner and outer third of the left ventricular wall was continuously measured with heated cross-thermocouples. The circumflex coronary artery was constricted with a thick string so that myocardial reactive hyperemia was nearly eliminated. Without constriction, a 15-second occlusion of the artery produced no significant changes in the resistance of large coronary arteries. On the contrary, in the presence of coronary constriction, a brief coronary occlusion caused a sustained decrease in distal coronary pressure and subendocardial myocardial flow during reactive hyperemia, while coronary flow returned quickly to the pre-occlusion level with significant reactive hyperemia of subepicardial flow. This change resulted in a long-lasting increase in the stenosis resistance. These results suggest that stenosis resistance changes dynamically, resulting in additional myocardial ischemia especially in the subendocardial myocardial layers.

Animals↗
PubMed1983

Increase in the resistance of stenotic coronary segment by intravenous infusion of isoproterenol.

The effects of intravenous infusion of isoproterenol on stenosis resistance were studied in the anesthetized open-chest dog. The circumflex coronary artery (LCx) was isolated near its origin and an electromagnetic flow transducer was placed around the vessel for measuring coronary flow. A polyethylene catheter was inserted into the small branch of LCx for monitoring distal coronary pressure. LCx was constricted with a thick cotton string to a degree of obstruction that eliminated reactive hyperemia following a 20-second coronary occlusion. The coronary resistance across the stenotic segment (RL) was calculated as the pressure gradient across the stenosis divided by coronary flow. Isoproterenol was infused intravenously in a dose to keep the heart rate at a level 25-30% above the control with and without coronary constriction. For maintaining the ascending aortic pressure at the pre-isoproterenol level, the descending thoracic aorta was constricted with a tape. In the absence of coronary constriction, the vascular resistance of large coronary arteries was not affected by isoproterenol with a significant increase in coronary flow. In the presence of coronary stenosis, isoproterenol markedly increased RI regardless of additional aortic constriction. The magnitude of the increase in RL during aortic constriction varied directly with the percent increase in the pressure gradient across the coronary stenosis. Pacing-tachycardia essentially did not affect RL. These results suggest that isoproterenol increased the vascular resistance of the stenotic segment with fixed caliber.

Animals↗
PubMed1983

Cardiorespiratory dynamics during sinusoidal and impulse exercise in man.

Dynamic characteristics of ventilation, cardiac output, and gas exchange during sinusoidally varying work rates for the periods from 1 to 12 min and impulse work rate with a duration of 10 sec were studied on five healthy men in an upright position. Changes in work rate were given by controlling externally the electromagnetic braking system of a bicycle ergometer. Stroke volume, heart rate, and cardiac output during exercise were determined continuously by using an automated impedance cardiograph. Breath by breath determination in minute ventilation, respiratory frequency, tidal volume, oxygen consumption, carbon dioxide output, end-tidal pressures of oxygen and carbon dioxide, and gas exchange ratio were conducted. From these and steady-state response data amplitude and phase relations between each variable and the input work loads were obtained utilizing the frequency analysis techniques. The response characteristics to sinusoidal stimuli were well represented by first-order models with time constants for VE, VCO2, VO2, and Q averaging 75, 67, 52, and 36 sec, respectively. The kinetics of HR closely resembled that of Q. There was a close link between both the dynamics of VE and VCO2. On the other hand, the responses to impulse stimuli were better described by second-order models in which fast and slow response components were connected in parallel. However, the contribution of the fast component to total response was small. Although this response may support in its form the neuro-humoral concept to explain exercise hyperpnea, a tight linkage was observed between VE and VCO2 responses to impulse stimuli. Thus, hyperpnea during the unsteady-state of exercise may be explained by the cardiodynamic hypothesis.

Adult↗