Dynamics of the killing of Ehrlich's murine ascites tumor cells by methylmercuric chloride, MMC, were investigated. Thresholds in the killing action of MMC were observed in the MMC treatment concentration, but not in the MMC treatment time. Inactivated bovine serum protected the E-cells from killing by MMC in vitro. The apparent MMC toxicity was reduced as the serum concentration increased, but remaining partially at high concentrations. Thus the serum increases the threshold for MMC toxicity. It was confirmed that the mode of action, observed as the kinetics of the acute lethality by suspicious substances, could be examined promptly on the mammalian cell level by the present experimental system.

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The authors have measured the power and endurable grip strength by five times repetition at five second intervals on post-office clerks (indoor service and outdoor service) and the personnel of harbor construction office (office workers and crew of dredger).
The results are as follows :
1) Grip strength (power : higher value either at the first or the second grip) has negative correlation with age.
2) Endurable grip strength (endurance : subtract lower value either at the fourth or fifth grip from the grip strength) of the indoor mail clerks and office workers has no correlation with age, but that of the others (the outdoor service and crew of dredger) has negative correlation with age.

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1. The urinary protein concentration was determined in 147 normal adult males by the membrane filter method. The geometric mean was 4.71 mg/dl and the range of m±2 S.D. was 1.71-12.97 mg/dl. They agreed reasonably well with reported “normal values” by other methods.
2. Concentrations measured by the membrane filter method also agreed with results semiquantitatively estimated by a routinely used test paper.
3. The variance of the urinary protein concentration for each category (-, ±, +, ++, +++) of qualitative test results was so large as to suggest a limitation of the paper test.
4. Significant decreases in renal functions were observed in carbon disulphide workers whose urinary protein concentration exceeded 13.0 mg/dl. Similar results were obtained even in workers whose urinary protein only mildly increased to 13.0-25.0 mg/dl.
5. Renal functions of workers whose urines were judged as (±) by the paper test did not reveal any decrease as compared with those whose urine were (-). However, when the two groups were combined and divided into two new groups by individual urinary protein concentrations, the group whose protein were 13.0 mg/dl and over showed significantly decreased renal functions as compared to the group with lesser urinary protein.
6. It is concluded that the quantitative determination of urinary protein is useful for earlier detection of renal injury in workers occupationally exposed to kidney poisons.

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The motor, sensory and mixed nerve conduction velocities of median and posterior tibial nerves were measured in seventeen forest workers engaged in chain-saw operation for 2 to 16 yr (mean 12 yr). The conduction velocities were significantly diminished in the distal part of the upper limb. The sensory nerve conduction velocities (SCV) of the median nerve at the part of the palm were slow in 12 workers; longer residual latency, in 6; and the mixed nerve conduction velocities slowed at the part of the forearm, in 6.
From the relationships of the nerve conduction velocities to white finger attacks and electromyograms, it was assumed that vibration directly affected the distal part of the sensory and motor nerve fibers in the upper limbs, ¹⁾ and that the diminished SCV in the palm was one of the most sensitive indices of vibration effects.²⁾

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3, 4-DCA (3, 4-dichloroaniline), an intermediate of carbamate- and amide-herbicides such as swep and propanil, is a substance which is hard to decompose thermally. That has been detected in metabolites or decomposed products of selective herbicides in plants and soil. These herbicides or 3, 4-DCA, once ingested into the human body, are excreted mainly in urine.
This study was one which attempted to establish the method of quantitative analysis of 3, 4- DCA in urine by using gas chromatograph with an electron capture detector.
1) The determination procedure : One to two ml of concentrated hydrochloric acid was added to 50 ml of urine for adjusting the sample to pH 1. After being hydrolysed at 60°C for 20 min, the sample was adjusted to pH 8 by addition of ammonium hydroxide. And then, 10 ml of benzene was added to it and the mixture was shaken well for 5 min and centrifuged at 3, 000rpm for 5 min. After separation of solvent, an aliquot portion of the benzene phase was directly injected for the determination of 3, 4-DCA into a Shimadzu GC-4 BPE gas chromatograph. The packings of the columns (1.0 m×3 mm i.d.) were 2% OV-17, 5% DC-11 and 20% Apiezon L treated with 10% potassium hydroxide on Chromosorb W, AW, DMCS.
2) When the concentration of 3, 4-DCA in urine was 5 μg/ml, the average recovery rate was 91% with the coefficient of variation of 1.7%. The detection limit of the method was 0.1 μg 3, 4-DCA per 1 ml of urine
3) The gas chromatographic method (GC-method) for 3, 4-DCA determination from urine was compared with the ultraviolet absorption spectroscopic method (UV-method). The analytical results of the GC-method were nearly the same as that of the UV-method.
The method is simple and accurate, since the concentration and clean up of the sample were not necessary in this method. It was supposed that the UV-method is to be used for routine work in a factory laboratory and the GC-method for cross check of analytical results and investigation of metabolism of 3, 4-DCA.

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