It seemed likely that a mechanism similar to that of Zymosan would be involved in the antitumor action of the Crepidotus polysaccharide, since it was shown in a previous paper that both agents had several characteristics in common in their antitumor action. Although the polysaccharide exerted direct cytotoxic action in vitro at high concentraiton (500μg/ml), an additional treatment with immunosuppresser such as corticosteroid and actinomycin D resulted in complete reversion of its antitumor action. Furthermore, it was found that the treatment with the polysaccharide brought about increase in the phagocytic function of RES. These evidences were suggestive of the host-mediated action mechanism of the polysaccharide.
1. The bile-tolerant (BT) strain of Lactobacillus was proved almost identical with its parent strain in many properties such as growth, acid production, many physiological properties, and serological aspect. 2. However, BT strain differed from the parent strain in several points: It had a tendency of poor coagulation of litmus milk. The increasing order of tolerance to acidity was as follows: BT (2) strain=parent strain>BT (1) strain; to NaCl was as follows: BT (2) strain>parent strain>BT (1) strain; to heat at 65°C in saline was as follows: BT (1) strain=parent strain>BT (2) strain. The increasing order of stability on exposure of freeze-dried cells to 37°C was as follows: BT (1) strain>BT (2) strain>parent strain. 3. Drop of tolerance to bile salts did not appear during a year storage of BT (1) strain in cell powder subjected to freeze-drying, or during serial transfer of it to bile free medium even after 10th passage, and its tendency of poor coagulation of litmus milk had been kept. However, the tolerance dropped during a year storage of BT (1) strain in cooked meat medium and its coagulation of litmus milk became positive. Thus, it was considered that both the tolerance to bile salts and the tendency of the poor coagulation of litmus milk were the properties possessed of BT strain and not of its sensitive parent strain. 4. The mutation rates seemed to be increased with the raise of bile concentration in the medium for transferring cultures. 5. The bile-tolerant (BT) strain of Streptococcus was proved almost identical with its parent strain in many physiological properties, except a tendency of poor coagulation of litmus milk.
Normal human serum contains an inhibitor which prevents the growth of non-pathogenic staphylococci. The inhibitor was named delta-factor. Properties of the factor were examined and the following results were obtained. Nutritional requirement of the bacteria was independent of the factor. The activity of the factor was not interfered with coagulase. The abilities of bacteria to produce coagulase and DNase were not related to the action of the inhibition phenomenon. The activity of the factor was stable and most active at pH 7.5-8.5 in ionic strength 0.05-0.25.
Stability of mycoplasmas against ultraviolet, urea, SDOC, NaCl solution, organic solvent and enzymic treatments was examined. The mycoplasma strains used were M. pneumoniae CL. FH, M. orale N-1, M. salivarium-C Hup 127, M. fermentans-C and M. hominis Type 1-C. M. orale N-1 was kindly supplied by Dr. Hayflick. These mycoplasma suspensions were tested in the resting states. The results obtained were as follows; 1) Four strains were generally stable to UV-irradiation; but M. orale was slightly less resistant than others. This strain was inactivated by the irradiation for 7 minutes. On the contrary, M. pneumoniae still survived after the irradiation for 10min. 2) The strains of mycoplasma were fairly sensitive to urea. All strains were not destroyed in 0.1M urea, but M. pneumoniae and M. salivarium were inactivated by the treatment of 1.0M urea for 120min. All strains were completely inactivated by the treatment of 3.0M urea for 60min. 3) In the case of SDOC, all strains except M. orale were not inactivated in 0.01% SDOC solution. However, all strains were inactivated in 0.1% SDOC solution. 4) Two strains tested, except M. pneumoniae, survived for 7 days in 1% NaCl solution, but all strains were inactivated in 3% NaCl solution for 24 hours. 5) In stability test of the strains to various organic solvents, it was interesting that M. orale and M. salivarium still survived against petroleum ether treatment for 24 hours at 4°C. Other two strains were completely inactivated by the treatment of organic solvents, such as chloroform, ethyl ether, toluene, n-butanol and benzen, for 24 hours at 4°C. 6) Treatments of various enzymes, such as α-amylase, lipase, pepsin, trypsin and papain, could not inactivate mycoplasmas, but only pronase which was derived from bacteria could effect to the activities of mycoplasma, and especially, M. pneumoniae was destroyed by digestion of this enzyme for 3 hours at 37°C.
Exposure of Habu-snake venom solution to heat at 56°C for 30 minutes causes protein precipitation, which is almost non-toxic. The toxicity of centrifuged supernatant is slightly weakened. When 70% alcohol is added to this supernatants, minute substances which are insoluble in water are precipitated, and the toxicity of the precipitate is remarkably attenuated. By the addition of 0.1%-1% formalin (or Aluminum Potassium Sulfate) to the precipitate, the attenuation of the toxicity tends to increase, and the amount of its protein content is less than 1/2 of that in the non-heated solution. Immunizing effect of formalin-added, alcohol-treated antigen proves effective enough to act as a satisfactory immunogen against the toxicity of Habu-venom-hemorrhagic necrotic damagea t the site. In order to produce antibody in man throng preventive injection against Habu bite, the formalin added, alcohol-treated antigen might be applicable without accompanying any serious by-effects.
In the course of experiments on bacteria in milk, a strain of Bacillus cereus which produced a protease was isolated. Some experiments have been performed to isolate and purify the protease. The enzyme activity was measured by Casein-Folin calorimetric method. The results were obtained as follows; 1) The bacillus is gram-positive, spore-forming and motile with peritrichous flagella. The organism is aerobic and grows well at 30°C, but does not at 55°C. The size of a cell is about 1.5×6μ. No acid or gas formed in medium containing xylose or arabinose, and acetylmethylcarbinol is produced. From these properties, the organism is regarded as a strain of B. cereus. 2) The bacillus was cultured on agar slant containing glucose and skim milk for 24 hours. When the culture grown on this medium was inoculated in a synthetic medium (pH 7.0) containing 1% glucose, it excreted the protease in the medium after 7 day-incubation, and then the culture showed the highest degree of enzyme production. 3) Concentrated cell-free culture was fractionated by means of methanol-fractionation. About 80% of the total enzyme activity was contained in 66-90% methanol fraction. This fraction was further purified through Sephadex G-50 equilibrated with 0.02M calcium acetate, and a fraction which showed simple peak by ultracentrifugation and single spot by electrophoresis was obtained. The sedimentation coefficient of purified enzyme was 20, ws=2.34S. 4) Digestive ability against casein of the purified fraction was several times higher than some other commercial protease. 5) The optimum temperature of this enzyme was 40°C and the optimum pH was 8.0. 6) Loss of the enzyme activity by heat treatment and by stock at 5°C was remarkably protected in the presence of 0.02M calcium acetate.