Utilizing the action potential as the indicator of excitation, the changes of the irritability in the nerve caused by subliminal current were detected. For the test shock, brief shock from induction coil was employed. A rectangular current of subliminal strength evokes rapid increase of the irritability in the nerve. The irritability curve ascends at first rapidly and reaches its maximum after 5 msec., then descends gradually to a final equilibrated state. An exponentially increasing current causes, also, the increase in the irritability in the nerve. In this case, the irritability curve has its crest. The final balanced states of irritability curves are similar, notwithstanding the CR-variances of increasing currents, if their final voltages are the same. The smaller the CR becomes, the shorter the ascending part of the irritability curve and the higher the maximum point of the curve becomes. The final equilibriated state of irritability depends only upon the final voltage of the current. If a large CR is chosen, the irritability reaches gradually the final balanced state ; and there appears no maximal point. When the CR is kept constant, the irritability curves reaches their maximal points simultaneously regardless of the final voltage, but the height of the final state is subjected to the final voltage. When a discharge current of subliminal strength is used for conditioning, the irritability at anodal region decreases rapidly to the minimal point, and returns slowly to the normal level thereafter. An algebraic summation of the irritability curves of rectangular current and reverse discharge current is approximately equal to that of the increasing currents of the same CR.
The values of accommodation constant, λ, of the toad nerve were measured by exponentially increasing current method and anodal break excitation method. When the nerve is intact, the value of λ measured by the increasing current method was as follows : 276.295±219.464 msec... To stimulate the nerve by anodal breaking shock, one must crush the interpolar region of it, to eliminate the cathodal making effect. Under such condition the value of λ obtained was : 14.05±6.46 msec... This value is strikingly smaller than that obtained by the increasing current method in the intact nerve. But the value of λ measured by the increasing current method was also small, if the nerve was crushed as above mentioned. If the nerves are under the same condition the values of λ obtained by the two different methods coincide well each other. This fact favours Hill's theory. The value of A decreases when the nerve is blocked by crushing the portion between anode and cathode. Up to the present, the abovementioned phenomenon can not be explained.
The author systematically investigated the absorption of sulfonamide preparations in the large intestine, thereby he attempted to make a contribution to the elucidation of the mechanisms of the absorption of various substances in the large intestine. Aiming at the survey of the absorption promoting substances, magnesium sulfate, urethane, chloral hydrate, cattle bile and urea were administered in combination. Urethane, chloral hydrate and cattle bile were employed for the experiments by the reason that these substances often acted promotingly in the absorption of penicillin, PAS and streptomycin in the large intestine. Magnesium sulfate was adopted as the control substance to the r above substances. Urea was also adopted because of the fact that urea is heretofore believed to act promotingly in the absorption of sulfonamide preparations when combined with sulfonamide preparations. The following was the conclusions obtained : The absorption of sulfonamide preparations in the large intestine is promoted by urea, chloral hydrate, cattle bile and urethane administered as combined substances. Furthermore, the absorption promoting action of these substances is stronger in the order as described in the above. On the other hand, magnesium sulfate, administered in combination does not act promotingly, but occasionally acts inhibitorily on the contrary.
Aiming at detailed investigations of the influences exercised by various substances on the absorption of histamine in the large intestine, the author selected bile components (cholic acid, taurocholic acid, cholesterin), rabbit bile, urea, thiourea, vitamin B1 hydro-ciloride, thiamine-propyl-disulfide and various surface active agents (Hyren, Emulgen 106, Tween 20, Span 20) as combined substances. In the case with surface active agents, duodenal infusions were also conducted in order to make comparative studies with the influences exer-cised on the absorption in the small intestine. Furthermore, in the cases when calcium preparations were administered in combination, the calcium content of the serum and peritoneal fluid was estimated in order to investigate the correlationships with the absorption of calcium, which had already been elucidated by Hitomoto and Kato. Pathological and histological investigations on the liver were also made, thereby the influences of histamine and other substances given in combination on the liver were observed. As the result of the present experiment, the following conclusions were drawn. The absorption of histamine in the large intestine is promoted by rabbit bile, taurochglic acid and cholic acid when they are given in combination with histamine, but the absorption promoting action of cholesterin is found to be slight. The absorption promoting effect of urea and thiourea, especially of the former, is also remarkably evident. Among the surface active agents, the absorption promoting action exercised by Hyren and Emulgen is especially remarkable. When histamine alone is administered, the pathological histologicgal findings of the liver is mild, but when administered in combination with rabbit bile, taurocholic acid, urea or with thiourea, the findings in the liver become evident. When calcium chloride is further combined in this case, the disturbances in the liver is alleviated.
Over a period of one week from October 7, 1953, the authors investigated the actual labor status of the workers in a machine factory situated in Tokyo. Simultaneously, we conducted various examinations on the fatigue sustained by 60 representative workers among those engaged in various kinds of jobs. The results obtained were as follows: (1) In most cases in the factory under the present survey, the intensity of the principal work allotted to various jobs was below 1.5 in terms of R. M. R., indicating that the work belongs to the category of light labor. However, the actual working time was remarkably long, and the actual working rate was around 100% both in the case of regular working time and on the cases of over-time work. Consequently, the amount of labor was almost reaching the maximum amount of labor reported by Shirai even in the case of regular working time, and it usually exceeded the maximum in the case of over-time work. (2) The flicker value, the number of circulating eosinophiles, the phagocytic actions of leucocy tes etc. showed the tendency of declining with the lapse of days, but they recovered the original values after one off-day (for example, after one Sunday) . (3) In the case of over-time work, the efficiencies in various jobs were found generally showing a tendency of declining compared with those in the case of regular working time. Specifically, the flicker value was found remarkably declined, demonstrating a highly significant difference. Consequently, the accumulated fatigue is readily presumed when such over-time work is forced to continue. (4) In view of the results of the survey on the actual status of the works in the factory under survey and the results of various examinations for fatigue, the weariness claimed by the workers is considered to be due to the nervous fatigue caused by the continuous working over a long time.