Readily available polysaccharides, amylopectin, amylose, dextrin, and yeast mannan. were chemically phosphorylated using polyphosphoric acid in the presence of a tertiary amine, and the resultant phosphates were examined for their interferon-inducing activity in rabbits employing an assay system consisting of a primary culture of rabbit kidney cells and vesicular stomatitis virus. All the phosphates were shown to be active as interferon inducer, and, especially, the activity of those containing more than 2% phosphorus were quite strong. Interfnons evoked by the above phosphates resembled those induced by bacterial endotoxin, e. g., the viral inhibiting activity was susceptible to heat treatment, low pH and tryptic digestion. Since all the parent polysaccharides showed no interferon-inducing activity. it is reasonable to assume that the activc center of these inducers might reside or be due to the anionic phosphate groups.

抄録全体を表示

Applying the observation by Yokota et al (1969) that a cell doubly harboring an R factor (R100) and a temperature senditive R factor (Rts1) produces segregant R factors with various resistance patterns, a total of 271 segregant R factors were obtained. There were 163 resistant to (sul, str, kan), 39 resistant to (sul, str, cml, kan), 62 resistant to (sul, str, tet, kan) and finally 7 resistant to (tet, kan). More than 90% of the former 3 segregants were fi⁺ and the remainder, including all of the (tet, kan) segregants, were fi^-. Some fi^- segregants with the former 3 resistance patterns and all of the (tet, kan) segregants were nontransmissible. All of these segregants were still temperature sensitive. Based upon the results of three experiments; (a) the growth at 43C to observe linked loss of the kan gene and the genes derived from R100, (b) a conjugal analysis of the relevant resistant markers, and (c) a transduteional analysis of these same markers, several conclusions were made. The 2R factors both consisting of a circle were supposed to have recombined to form a larger circle which then further resulted in the final formation of smaller circles. The possible bearing of these observations and conelusions on the genetic structure of R100 was discussed.

抄録全体を表示

The distribution of the dihydrostreptomycin (DHSM)-phosphorylating enzyme was investigated using DHSM-resistant strains of Pseudomonas aeruginosa, indicating that this enzyme was demonstrated from all of 7 DHSM-resistant strains examined but not from a DHSM-sensitive one. The DHSM-phosphorylating enzyme was isolated from P. aeruginosa TI-13 and purified about 205-fold using Sephadex G-75 and DEAE-Sephadex A-50 column chromatography. The optimal pH for the DHSM-inactivation was around 10.0. and both adenosinetriphosphate (ATP) and Mg⁺⁺ were required for the inactivating reaction. It was found that this cnzyme inactivated only DHSM but not other aminoglycosidic antibioties such as kanamycin, aminodeoxykanamycin, neomycin, paromomycin, lividomycin and gentamicin.

抄録全体を表示

In vivo induction of resistance to macrolide (Mac) antibiotics was investigated using mice infected with Staphylococcus aureus MS537 followed by treatment with either erythromycin (EM) or josamycin (JM). An EM-inducible strain MS537, in which only EM was an active inducer for Mac resistance, acquired in vivo resistance to both Mac antibioties and lincomycin (LCM) 2hr after an EM injection but the resistance of the induced cells was lost 2 days thereafter. Consequently, EM was found to have no therapeutic effect on MS537 infection and the number of resistant hacteria recovered from the kidney increased even after 6 intraperitoneal injections of 0.2mg each of EM; the number of bacteria recovered from the kidney showing the same level as the controls without treatment. JM, one of the non-inducers for Mac resistance, by contrast, showed a therapeutic effect on MS537 infection and the number of organisms recovered from the kidney decreased to one-thousandth of that obtained with EM treatment, resulting

抄録全体を表示

Germ-free chickens were monocontaminated or dicontaminatcd with microoganisms isolated from the cecal contents and feces of chickens. In the case of monocontamination, the viablc number of oganisms in the alimentary tract considerably varied depending on the species or genus. Staphylococcus epidermidis, slreptococcus faecalis var. liquefaciens and Escherichia coli became established in much larger numbers in germ-free chickens than in ordinary birds. While Bifidobacterium thermophilum and Catenabacterium sp. were unable to become established, other anaerobic organisms and a strain of yeast became established almost at the same level as in the ordinary microflora. Anaerobic non-sporeforming gram-positive rods (AR), which were occasionally found in the ordinary chickens. were always well established throughout the gut of monocontaminated birds. In the case of dicontamination, the numbers of S. epidermidis, Catena-bacterium sp. and B. thermophilum were comparable to those in the ordinary microflora. Growth of S. epidermidis was suppressed by E. coli. Calenabacterium sp. and B. thremophilum became well established when giycn in combination with other bacteria, except that the establishment of B. theimophilum in combination with catenabaclerium sp. was irregular. Growth of AR was prevented when administered together with. E coli On the other hand, the numbers of E. coli and S. faecalis var. liquefaciens were continuously large even in the presence of any other bacterium.

抄録全体を表示

Primary and secondary antigenic stimuli were given in the presence of antibody in order to study the role of antibody in the induction of the subsequent immune response. Primed cells immunized with crystalline bacterial α-amalase (BαA) and crystalline Taka-amylase A (TAA) were more effectively stimulated by antigen bearing cells which had been previously prepared by exposure to the two antigens in the presence of anti-BαA or anti-TAA than in the absence of the antibodies. The augmcnting effect of the antibody was specific in relation to the antihody added. The primary antibody responses to BαA and TAA were also specifically augmented by the presence of the corresponding antibody, when two antigens were mixed with the antibody and injected intravenously into normal mice. When dinitrophenyl (DNP) residues were introduced to BαA, the immune response stimulated by DNP-BαA was also augmented by anti-DNP anti-body. Although specificity of the response augmented by anti-hapten or anti-carrier antibody may be determined on a cellular level, the specificity of response augmented by either of these antibodies extended to the hapten as well as the carrier-determinants. Thus, the Presence of antibody directed against any of determinants on an antigen, might result in widening the spectrum of responsiveness of the animal to other antigenic determinants.

抄録全体を表示

Antibody response against hamster red blood cells (H-RBC) was cxamined in inbred strains of C57BL/6, AKR, C3H/He, DDD and SL mice, and outbred CF1 mice. 1) There were strain differences in antibody response after a primary intravenous injection of H-RBC. DDD, SL and CF1 mice belonged to high-responder strains, while C57BL/6, AKR and C3H/He to low-responder strains. In the spleens of immunized CFl and SL, 40 to 70 times as many plaque-forming cells (PFC) as those in C57BL/6 mice were detected. The magnitudes of the response were: CF1≠SL>DDD>>C3H/He≠AKR>C57BL/6. 2) 2-mercaptoethanol resistant (MER) anti-body was detected in neither low-nor high-responders after a primary intravenous antigen-injection. 3) After a secondary intravenous antigen-injection, MER antibody was detected in all the SL mice, but oniy in 30 to 50% of AKR and C57BL/6 mice. 4) A subcutaneous in-jection of H-RBC in Freund's complete adjuvant (FCA) did not elicit antibody production within 10 days. When mice pre-sensitized 7 days in advance with H-RBC in FCA were intra-venously injected with H-RBC. enhanced antibody production of the primary type was observed in all the mouse strains. 5) In pie-sensitized mice, the extent of the enhancement of antibody production was the highest in low-responder C57BL/6 mice and the lowest in high-responder SL and CF1 strains. Thus, there was no strain difference in antibody titers or the numbers of PFC after the booster.

抄録全体を表示

The mechanism of enhancement of growth of partially ultraviolet (UV)-inactivated Newcastle disease virus (NDV) in HeLa cells persistently infected with hemagglutinating virus of Japan (HVJ) (HeLaHVJ) was investigated. HelaHVJ cells and normal HeLa cells were inoculated with UV-irradiated NDV under similar experimental conditions, and numbers of both infective centers and NDV-antigen producing cells in each culture were counted. It was found that the percen-tage of HeLaHVJ cells which produced infectious NDV or NDV-antigen during the first cycle of infection was approximately 1.5 times higher than that of normal HeLa cells. Survival rurvs of UV-irradiated NDV showed that NDV appeared more resistant to UV when titrated in HeLaHVJ cells than in assay in normal HeLa cells. Possible explanations for this phenomenon were discussed

抄録全体を表示

A derivative of thiosemicarbazone γ-thiochromanone-1-thiosemicarbazone (SN-13), which differed from N-methylisatin-β-thiosemicatbazone (marboran) in that the carbonyl group in the C₂ position of N-methylisatin was lacking, has been found to possess an anti-vaccinia ellect as determined by the pulp disc method of plaque inhibition and by inhibition of cytopathic effcet in tube cultures of chick embryo cells as well as by prevention of mouse tail lesions by the vaccinia virus. In tube culturs, SN-13 was shown to be ellective even when the treatment was started as late as 8hr after virus infection, whereas no activity was observed with marboran when started from the 8th hr SN-13 was as effective as marboran on cross treatments of vaccinia virus, with the two compounds in tube cultures, either by treatment at an early or a late stage of the virus growth, Moreover, the inhibitory effect of SN-13 on vaccinia virus growth was completely reversed by actinomycin D similar to that observed with marboran in tube cultures. No additivc ellect of the two compounds was obseived in animal tests.

抄録全体を表示