The author investigated the toxicity and the biological changes occurred when linear alkylbenzene sulfonate (LAS) was orally administered. In the acute toxictiy using mouse, LAS has an LD50 was 2.30g/kg and a 95% reliable range was 1.52 to 3.55g/kg. Body weights of rats increased normally in the LAS conditioned group as same as in the control group. In the LAS administerd group, pathologic changes were not remarkable.
The decomposition effect on hydrogen peroxide (H2O2) in Japanese noodle by the addition of some materials (ascorbic acid, ferrous or ferric chloride, sodium bisulfite) was studied in the previous papers. In this papers, the decomposition effect on H2O2 was studied on about 30 kinds of natural materials. The remarkable effect was found in foxtail millet flour, rye flour, milo flour, Japanese barnyard millet flour, pectin, and some amino acids. The element reactive with H2O2 was present in the protein fractions of some cereal flours.
Residue measurements were studied for polychlorinated biphenyls (PCB) and organoch-lorine pesticides in corbiculae (Corbicula sandai Reinhardt) from Lake Biwa in an attempt to estimate when PCB contamination had occurred in our environment. The corbiculae samples taken from 15 places in 1963 were preserved in formalin and the samples from 9 places in 1971 were frozen while awating analysis. Corbiculae tissues were blended with anhydrous sodium sulfate and n-hexane in a Waring blender. The fat extract was cleaned up by the twin-dry column method described by Holden et al. Electron capture Gas chromatograph with electron capture detector was used for qualitative and quantitative analysis of the residues. Quantitative analysis of PCB was accomplished by comparison of the area under the curve of two major eluters with a Kanechlor-500. DDE was determined by difference of the area on gas chromatogram before and after oxidation according to the modified method of Westoo et al. PCB, BHC, DDT and dieldrin were detected for all samples in both 1963 and 1971. Residue levels in 1963 were as followed; PCB 0.04-2.4, total BHC 0.013-0.075, total DDT 0.031-0.14, dieldrin 0.001-0.004 (ppm on fresh tissue basis). Levels in 1971 were as follows; PCB 0.06-1.1, total BHC 0.087-0.25, total DDT 0.038-0.093, dieldrin 0.002-0.004, PCB detected in all samples was similar to Kanechlor-500 in individual gas chroma-togram.
The effect of 60Co γ-rays on the dormant buds of potatoes was examined with two kinds of stocks, “Danshaku” and “Nôrin No. 1” on the market. Exposure doses of 7, 000, 15, 000 and 30, 000rad were used. After the resting period, normal buds developed on the control (not irradiated), whose growing points were covered by young scaly leaves, and the stem grew with lateral root. (Fig. 1) On the other hand, abnormal buds developed on the irradiated samples, whose growing points were not covered but were surrounded by young swollen and deformed leaves, and the stem and lateral root never developed on them. (Fig. 2) Whether potatoes have been irradiated or not can be detected by observation of bud shape, but the detection is very difficult during the resting period. Abbreviations used in text-figures are as follows: -bu: bud, gp: growing point, rol: lateral root, ylf: young leaf.
The effects of gibberellin and kinetin on the dormant buds of irradiated potatoes and the control were examined with two kinds of stocks, “Danshaku” and “Norin No. 1” on the market. (1) In the case of control (not irradiated), seven days after treated with gibberellin in darkness, the bud developed into a white stem of about 20mm in length, by elongation of the internode from the sixth to eighth node. (Fig. 1) Seven days after treated with kinetin in light, the control buds developed into a crimson rosette of about 2mm in diameter, by its young leaves becoming scaly and eliptic. (Fig. 2) (2) In the case of irradiated samples, when treated with these reagents, the bud showed no visual change even in fourteen days. The apparent difference was observed on the treated buds between the irradiated samples and the control. Whether potatoes have been irradiated or not can be detected by observation of the treated bud shape. Abbreviations used in text-figures are as follows: -axb: axillary bud, bu: bud, gp: growing point, h: hair, ylf: young leaf.
An outbreak of food poisoning occurring in the Shizuoka Prefecture on June, 1969, was inferred to be caused by heat-sensitive Clostridium perfringens on the basis of epidemio-logical studies and bacteriological examinations. The results obtained are summarized as follows. 1) Patients were employees of plants and offices in and around Numazu and Mishima Cities. Disease occurred in 313 persons out of 1816 who ingested the suspected food. Incubation period averaged about 11 hours (2-42 hours). Main symptoms consisted of diarrhea and abdominal pain with some chills, headache and nausea. Pyrexia and vomiting were rare. These symptoms were similar to those observed in infections with heat-resistant C. perfringens. 2) Epidemiological studies indicated the source of food poisoning as the catered lunch. Since no food remnants were obtainable, bacteriological examinations were carried out only on faeces of the patients. As a result, heat-sensitive C. perfringens Hobbs' type 4 was isolated from 16 out of 34 patients (47.1%), and suspected to be mainly responsible for the present food poisoning. The organisms were not isolated from heat treated faeces (100°C, 60min), but from non heat treated faeces. 3) While the causative organism was identified as the Hobbs' type 4, based upon its serological properties, the spore did ont withstand heating at 100°C for ten minutes in the medium of Kim et al. used for spore formation. The value ofα-toxin was 0.3-0.6.
Isolates of Staphylococcus aureus from 34 food poisoning incidents in Tokyo during 1969-1970 were examined for their ability to produce enterotoxins A, B, C and D. Enterotoxins were produced in NZ-Amine medium with shaking and the culture supernatants were concentrated to 1/25-1/30 volume by dialysis against equal volume of solution of 50% polyethylene glycol 20, 000. Each enterotoxin in the concentrated culture supernatants was detected serologically by slide gel diffusion test. Enterotoxins A, B, C and D were demonstrated on isolates from 33 out of 34 incidents (97%), and in some instances two enterotoxins were produced by one strain; isolates from 8 incidents produced enterotoxin A, 1 produced enterotoxin B, 7 produced enterotoxin C, 3 produced enterotoxin D and 14 produced enterotoxins A and D. In a result of the survey, enterotoxin A, and enterotoxins A and D were predominant types in the food poisoning. All of 34 strains of Staphylococcus aureus from food poisoning incidents could be typed by means of coagulase typing, viz., 10 as type II, 9 as type III, 7 as type VI and 8 as type VII, respectively. In addition, a total of 400 strains of Staphylococcus aureus isolated from fingers, noses and feces of healthy subjects, and commercial foods without the association to food poisoning incident, which consisted of each 100 strains per a source, were examined for enterotoxin production and coagulase typing. Three hundred and sixty-two strains out of them produced enterotoxins A, B, C or D, and some strains had productivity of two, three or four enterotoxins. Out of enterotoxin producing strains, 99 produced enterotoxin D, 90 produced enterotoxins C and D, 48 produced enterotoxins A and C, 39 produced enterotoxins A, C and D, 30 produced enterotoxin C and 16 produced enterotoxin A (see table 2). Four hundred strains of Staphylococcus aureus from the materials not associated with food poisoning incident were also typed by coagulase typing, viz., 10 as type I, 35 as type respectively. From the results mentioned above, it was indicated that there was no correlation between enterotoxin types and coagulase in the strains used, while the most number of the strains producing enterotoxin B were typed as coagulase type IV or V.
Each component in 110 groups of two-component mixtures consisting of 11 kinds of food color was analyzed directly by dual-wavelength spectrophotometric method (Model 356 Hitachi dual-wavelength recording spectrophotometer) without chromatographic technique. The most suitable reference wavelength (λ1) and measurement wavelength (λ2) chosen were shown in Table 2. The calibration curves obtained by using mixed solutions containing the analyte and diverse component of food colors were linear in the ratio 0-2.5: 1 between the analyte and interfering component, and correlation coeficient was 0.993-1.000 (Table 3). This method was applied for the determination of each component in artificial and commercial preparations of food color mixtures. Recoveries of mixed solutions were 93-101.18per cent (Table 4) and dye content of commercial samples analyzed by this procedure ranged from 69.20 to 140.48per cent of labelled amount (Table 5). This method may be useful for quantitative analysis of food color mixtures.
Imported and domestic natural bulk talc and commercial talc packaged in Japan were fumigated with ethylene oxide or propylene oxide on suspicion of bacterial contamination by the environment. Bacterial and mold counts on samples were decreased extremely after fumigation. The sterilizing effect of ethylene oxide upon organisms was greater than that of propylene oxide. Residual gases and ethylene chlorohydrin or propylene chlorohydrin in fumigated samples were not detected by gas chromatography. Fumigation of natural bulk talc and packaged talc with ethylene oxide or propylene oxide was effective to control viable organisms.