From a series of experiments on nine human volunteers carrying different loads on the head up a flight of stairs at a fixed rate of ascent, it has been shown that the energy cost (E) is linearly related (r=0.97) to the gross weight carried, namely the sum of the weight of the individual (W) and the external load (L), according to E (kcal/min) =0.0737(W+L) (kg) +0.0413. The peak heart rate (PHR) attained by the subject also showed a linear correlation (r=0.88) with the gross weight PHR(no/min) =1.33(W+L) (kg) +53.69. These regressions are highly significant statistically. It has been demonstrated that, it is possible to predict from these regressions with consider-able accuracy the energy cost and peak heart rate for such muscular work for a similar group of human subjects carrying similar loads by independent tests on six subjects. The mechanical efficiency of this physical task has been computed in each case. The gross efficiency and the net efficiency i.e., the external work performed as percent-ages of the gross and net energy costs (gross energy cost minus energy cost at rest) are remarkably consistent for the different subjects, with mean value and net efficien-cies respectively. A concept termed "Work Pulse", being the external work performed in kilogram meters per heart beat, has been proposed as a practical measure of efficien-cy. The value of this simple index for studying the work stress-strain relationship has been discussed.
The oxidation mechanism of human haemoglobin by p-quinone was investigated in aerobic and anaerobic states. In anaerobic state, in which all haemoglobin molecules were in reduced form, the oxidation took place according to the following reaction formula, Hb+2 p-quinone+4H2O → Hb(OH)4+2 hydroquinone In aerobic state, at the initial stage of the reaction the same reaction as that in anaerobic state may occur, but in the later stage many reactions, of which a further investigation is awaited, are supposed to occur simultaneously.
To examine pituitary-adrenocortical functions of workers exposed to nitroglycol some investigations were made. 1. Evaluating by the reaction to 25 units of ACTH-Z (ACTH-Gel), the decrease of the adrenocortical functions of dynamite workers were noted, in spite of rather healthful environmental conditions of the investigated shops. The decrease of eosinophil counts induced by ACTH injection was remarkably small. 2. In case of 0.25 mg synthetic ACTH administration similar data were obtained con- cerning the decrease of circulating eosinophil counts. 3. The increase of the circulating concentration of free plasma 11-hydroxycorticosteroids, which was induced by 0.25 mg synthetic ACTH administration, was obviously small in case of workers who had been exposed to nitroglycol so far. 4. No significant correlation was acquired, however, between ACTH-induced eosinopenia and increment of the steroids. The general conclusions drawn from the above data are that the pituitary-adreno- cortical functions which were evaluated by Thorn's test and rapid ACTH test decreassed in the workers exposed to nitroglycol, and that the dysfunctions are connected with the outcome of sudden death in case of the serious nitroglycol poisoning.
This study was carried out to make clear the chronic effect of toluene on the peripheral blood and adrenal gland. In this experiment, twenty four rats in growing period were used and divided into four groups. Rats of three groups were exposed to 200, 1000 and 2000 ppm toluene vapour for eight hours a day during 32 weeks respec-tively, and then exposed to 250 ppm benzene vapour for 39 days. Rats of the other one group were used as control and exposed to only 250 ppm benzene. During the exposure to toluene and benzene vapour, these rats were examined on body weight, erythrocyte counts, hemoglobin contents, hematocrit values, plasma total protein, leucocyte counts, eosinophiles and appearance-ratio of Mommsen's toxic granules. When the exposure to benzene finished, all rats were killed by decapitation, and the internal organs were weighed and examined patho-histologically. The results obtained were as follows. 1. The hematopoietic system showed no remarkable change in this experiment. From this experiment, it seems inappropriate to estimate the toxicity of toluene by the results of blood examination. 2. The values of eosinophile counts in the exposed groups decreased rapidly in the first three weeks, and then showed a gradual increase till the previous values, though the process differed by the concentration of toluene. The weight of adrenal gland per body weight were significantly lighter in the exposed groups than in the control. The patho-histological examination showed the build of the secondary hypofunction of the adrenal cortex. This fact may suggest that the function of diencephalon-hypophysis-adrenal cortex system are suppressed by the chronic toluene exposure. 3. From these results, the author thinks that the present value of MAC of toluene (200 ppm) should be reconsidered in the near future.
Some disturbance in the conversion of delta-aminolevulinic acid to coproporphy-rin in the kidney of lead poisoned rabbits was examined. The supernatant of homogenate of the liver and the kidney and of hemolysates of red blood and bone marrow cells from lead poisoned rabbits were incubated with delta-aminolevulinic acid to estimate porphobilinogen and porphyrins synthesized. Coproporphyrin isomers were also analysed. Porphyrins were found to be produced in larger amount by the kidney from poisoned animals than from control ones, and to the greatest degree by the hemolysates. Coproporphyrin was produced about two times as much in the kidney of poisoned animals as in that of control. Coproporphyrin produced was identified to be largely of type I in the liver and of type III in red blood and bone marrow cells. It seems that while the kidney plays a certain role in increased urinary excretion of type I coproporphyrin, urinary coproporphyrin is mostly of erythropoietic origin in lead poisoning.
Five strains of mice (ICR, ddN, CF#1, CFW and C3H) were divided into 4 groups respectively, which received benzene subcutaneously on the back at doses of 0, 0.2, 0.5 or 1.0 ml/kg for 5 days. On the sixth day of the experiment, body weight, hemoglo-bin, erythrocyte, leucocyte, thrombocyte, thymus weight and spleen weight were measur-ed to evaluate benzene intoxication. 1. Among five strains, ddN was the most susceptible and ICR was the least susceptible to benzene. 2. Male mice were found more susceptible to benzene than female in most strains of mice. 3. Useful criteria for benzene intoxication in mice might be leucocyte count, thymus weight and spleen weight. 4. ICR and ddN might be good strains for the experiment of benzene poisoning because of small coefficients of variance.
Heat treatment of the serpentine minerals changed their biological effects in original state, and all serpentine specimens showed a remarkable cytotoxic and hemolytic action after treatment around 650°C. The mice injected intraperitoneally with minerals treated in this temperature range mostly died within 48 hours after injection, while with original mineral or the minerals heated in the other heat ranges did not. To clarify this reason mineralogical study was carried out by means of X-ray, thermal differential and infrared analyses and it was found that materials treated in this temperature range showed a highly disorganized structure. It was assumed that the change of biological effects by heat treatment may be related to the disordered state of serpentine in the process of their transformation into forsterite.