Eimatsu Takakuwa

γ-Glutamyltransferase from AZO dye induced hepatoma and fetal rat liver. Similarities in their kinetic and immunological properties

Some properties of gamma-glutamyltransferase ((gamma-glutamyl)-peptide: amino-acid gamma-glutamyltransferase EC 2.3.2.2) from azo dye induced hepatoma and fetal rat liver were studied using kinetic and immunological criteria. There was no significant difference between the hepatoma enzyme and fetal rat liver enzyme in some of their catalytic properties. Antisera against the purified hepatoma enzyme also reacted to the fetal rat liver enzyme in the inhibition test and the precipitin reaction. A structural similarity between the hepatoma enzyme and fetal rat liver enzyme was observed and the acquirement of fetal characteristics in hepatoma was discussed.

A solid-phase radioimmunoassay for human carbonic anhydrase B.

A sensitive and specific radioimmunoassay method for human erythrocyte carbonic anhydrase B was developed using a solid-phase technique. The assay was found to be sensitive for the detection of nanogram amounts of the enzyme in incubation mixtures. Iodination of it gave rise to a loss of antigenicity and a solid-phase assay technique using antibody-coated paper discs was employed in order to exclude the chemical modification or conformational changes of the enzyme. The levels of carbonic anhydrase B in the erythrocytes of newborn infants and in some biological fluids were determined.

Effects of food dyes on Paramecium caudatum: Toxicity and inhibitory effects on leucine aminopeptidase and acid phosphatase activity

Abstract The toxic effect of 14 food dyes was studied in Paramecium caudatum . It was found that xanthene dyes containing halogen atoms in their molecules were more toxic than other groups of food dyes. Phloxin and rose bengal containing chlorine were especially toxic. The effect of food dyes on leucine aminopeptidase, acid phosphatase, and γ-glutamyl transpeptidase activity in P. caudatum was studied in order to investigate the mechanism of toxicity. Phloxin and rose bengal inhibited leucine aminopeptidase remarkably. The inhibitory effect of food dyes on leucine aminopeptidase in vitro is consistent with the toxic effect of the dyes on the survival time of P. caudatum . A possible correlation between toxicity and inhibition of the activity of enzymes involved in the digestive process is discussed.

A solid-phase radioimmunoassay for human β3-microglobulin

A simple and relatively rapid as well as highly reproducible determination of beta2-microglobulin is described for general laboratory use. The method is based on a solid-phase radioimmunoassay paper discs as a solid-phase material. The assayable range is approximately in the range of 2 ng to 20 mug of beta2-microglobulin with a precision of approx. 5 percent. This assay requiring only 0.05 ml of urine can be completed within 20 h. Urine in cadmium-exposed workers and residents in cadmium-polluted districts including patients with itai-itai disease were examined and considerable amounts of beta2-microglobulin were observed in these urines.

Studies on the function of concentration maintenance (TAF) Part 4

In the previous paper the authors reported that a muscular work load resulted in the lowering of the function of concentration maintenance (TAF), the grade of which significantly correlated with the volume of oxygen consumed for the work.The present experiment has been carried out to discuss about the lowering of TAF due to muscular work from the viewpoint of excitability level of spinal motoneurone, the final common path of motor nerve system, in relation to the physiological function as one of the factors of the change of TAF.Eighteen healthy male students were loaded with bicycle ergometric work of oxygen consumption of 710ml/min. for 90 minutes. Before and after the work load, they were administered the TAF test, measurement of eye-hand reaction time and recording of H-wave recovery curve from the right lower extremity.The results obtained were as follows:1. The function of concentration maintenance tended to lower with muscular work.2. Comparing the reflexes appeared in H-wave at time intervals of 50 to 900 msec between the conditioning shock and the test shock, the suppression in H-wave recovery curve with ergometric work was noticeable at both 100 and 400 msec against the pre-work values.3. Lowering of the excitability of spinal motoneurone corresponding to muscular fatigue was revealed by a significant correlation between the inhibition rate in H-wave (post-to-pre value) at 400 msec of shock interval and the time of appearance of irregular Pipers rhythm as myographical fatigue.It is reasonable that the excitability of spinal motoneurone lowers at 100 msec in the process of after-hyper-polarization, while the fact that even beyond the rage of the process, at 400 msec, a significant suppression in H-wave recovery curve was observed may suggest also a lowering of its excitability without regard to the relative refractory period of after-hyper-polarization.These results lead us to recognize that the lowering of TAF due to a physical load may be caused by the central depressive action in relation to muscular fatigue.

STUDIES ON THE ABSENTEEISM DUE TO SICKNESS IN INDUSTRIES OF HOKKAIDO (PART 2)

Investigations on sick absence, the summer data (1964) of which had been reported in part one of the studies, was continued for one year. The winter data thus obtained are compared in this report with those of the summer. Observations in Hokkaido were analysed from the viewpoint of frequent absence, classification of diseases, and the difference of occupations, in comparison with those of all Japan. The following results were obtained. 1) Incidence rates per 100 persons per year in the factory (scale 1) and mine (scale 2) were almost the same as those of all Japan in both scales (scale 1: less 500 employees, scale 2: 500-1, 000 employees), while in the transportation industry (scale 3: more than 1, 000 employees) showed a very low rate of about one third of that of all Japan. (Fig. 5) 2) Incidence rate per month was higher in winter than that in summer in all Japan, while in Hokkaido there was no difference in the factory (scale 1) and it was lower in winter than in summer in mines (scale 2) and transportation (scale 3). Considering the severe winters of Hokkaido, this observation is very interesting. (Fig. 6) 3) According to the distribution (%) of diseases as a cause of absence, VIIIa (common cold) and XIb (gastro-intestinal diseases) were the most frequent, approximately one third of all diseases were common colds. These tendencies were almost the same as those of all Japan. (Fig. 7) 4) Attention shold be put on the fact that XVII (occupational accident) especially XIII (diseases of the bones and organs of movement) was high in incidence in the mine. Health and safety management must be promoted further. (Fig. 7) 5) In the distribution of absentees by number of absence per year, those of six times or more were as high as 10% in the factory. When the incidence and severity rates are taken into consideration, it is recognized that there were many persons of frequent absence of short duration in the factory. The highest was absence of once a year, being 55% in the mine and 70% in the transportation. The rate decreased in inverse proportion with the increase of absence frequency. (Fig. 8)