Hen egg white Iysozyme was azo-coupled with benzene sulfonic acid diazonium salt-S35. The coupling reaction introduced azo groups mainly to lysyl residues and partly to tyrosyl residues. It caused the change of the biological activity of lysozyme. The lytic activity was effected with the azo-coupling, but the hydrolytic activity was not.
A white leghorn hen was injected with tryptophan-3-C14. The labelled lysozyme was prepared by the DEAE-cellulose chromatography from the radioactive egg white obtained during 24-48 hours after the injection. It was elucidated that the tryptophan-3-C14 was incorporated into only tryptophan residues of lysozyme molecule.
Human milk and leucocytes lysozymes had prepared from human milk and leucocytes by a simple method. They were biochemically compared with hen egg white lysozyme. Human lysozymes were different from hen egg white lysozyme in regard to the biochemical properties. Both of human lysozymes were recognized to be similar about enzymic activity, chemical composition and physical proper-ties.
Donryu, Wistar and Sprague-Dawley strains of rat were studied on their responses to the subcutaneously administered benzene at dose levels of 0, 0.2, 0.5 and 1.0 ml/ kg/day for 5 days. Criteria were body weight, hemoglobin, eryth rocyte, leucocyte, thrombocyte, thymus weight, and spleen weight. Among 3 strains of rat, Sprugue-Dawley was found most sensitive to benzene and to respond at a 0.5 ml/kg dose level. Female showed higher susceptibility to benzene than male. Useful criteria for benzene intoxication in rat might be the decrease of body weight, leucocyte count, thymus weight and spleen weight, and the increase of thrombocyte count. The Sprague-Dawley rat is found to be the best animal strain in the benzene intoxication experiment because of having many critical organs, the high-est suseptibility to benzene, and the smallest variation of the measurement. And the standardization of benzene poisoning experiment was shown from the viewpoint of animal species, dose and critical organs in relation to minimum effectivedose.
Three problems, i. e., the distribution of mercury in the blood after the exposureto mercury vapour, the relationship between the mercury contents in urine, red cells, plasma and hair, and the evaulation of extents of occupational mercury exposure and non-occupational one, were examined on workers exposed to mercury vapour. To es-timate the mercury of inorganic mercury form, Magos and Cernik's method was used for the undigested urine, red cells and plasma. The hair was extracted by a solution of 1 N HCl. The extract was applied to the mercury vapour photometry. By oxidation and application of oxidized materials to the photometry, the total content ofmercury was estimated. A larger amount of inorganic mercury was found in the plasma than in the redcell, but the portion of mercury measurable by oxidation, namely mercury in Hg-C bond or organic mercury, was distributed to the red cell in a much higher content to the plasma. A significant correlation was found between the contents of mercury of inorganic one in the plasma and in the urine, and between the contents of mercury of organic one in the red cell and the hair. Because of the fact that the non-occupational exposure to mercury was mainly due to methylmercury in Japan, the total content of mercury in the red cell or the hair was markedly changed from a hypothetical levelconsidered for the workers exposed solely to mercury vapour.
Haemolysis of rabbit erythrocytes caused by alkylmercuric compounds in vitro and their interaction with a phospholipid monolayer were investigated. Intensity of their haemolytic action was in the following order : n-buty1- > n-propy1- > ethy1-> methyl-mercuric chloride. The interaction of these alkylmercuric chlorides with the phospho-lipid monolayer was the most intensive with n-butyl derivative being followed by other derivatives with the same order as seen in the haemolytic action. In the case of ethylmercuric phosphates, intensity of their interaction with thephospholipid monolayer was also found to be in the same order which has been obtain-ed for intensity of their haemolytic action, namely the order was as follows : tri-> di- > monoethylmercuric phosphate. From these results, a role of the alkyl groups of these compounds to their penetra-tion into erythrocyte membrane was discussed.
The toxicity of a chemosterilant, metepa, tris [1-(2-methyl) aziridinyl] phosphine oxide, to rats and mice was studied. 1) The acute oral LD50 value of metepa was 277 mg/kg for rats, compared with 292 mg/kg for mice. The dermal toxicity was 375 mg/kg for mice. 2) In the subacute toxicity test on male rats, given orally metepa totalling 480 mg/kg in 8 days, metepa showed the typical properties as an alkylating agent. It caus-ed the profound effects against the proliferating tissues such as the testes and the bone marrow. The spleen was also affected. Further, the growth suppression and the reduction of blood cell counts were noticed. 3) Daily oral administration (2.5-20 mg/kg/day) of metepa to rats for 84 days caused the growth suppression, the reduction of white blood cell counts and the testi-cular atrophy at higher levels. Severe degeneration of spermatogenic cells and occasio-nally multinucleated giant cells were observed microscopically. Although female rats appeared in general less sensitive to metepa than males, the histopathologic examination revealed the lesions in the ovaries even at a level of 5 mg/kg/day. No-effect level for three-month test appeared to be 2.5 mg/kg/day for male rats and was not fixed for females by the present experiment.
A combined use of X-ray fluorescent analysis and X-ray powder diffraction analysis is proposed for collecting precise and systematical information about the fundamental characteristics of fume from very small amount. This method, completely non-destruc-tive in most cases, can analyze directly the samples collected on filter paper and is able to determine rapidly their chemical compositions and crystal phases at the same time.