Studies on the process of lysogenization was performed with the specified system of temperate phage β and KA cell (Shigella flexnerii type 5) on which concentrated researches have been made by other workers in this laboratory.
In this system some of the survivals of infected cells usually form colonies with irregularly bitten edge. Replating these unentire colonies and assaying for the phage-producing ability and phage-sensitivity, it was found that these colonies consisted of both lysogenic cells and mostly sensitive cells, being partially lysed by phage liberated from their lysogenic members.
The growth of infected survivals was followed to elucidate the manner with which sensitive cells originate. Thus, the decrease in the fraction of lysogenic centers to total population accompanying with the division of infected survivals was definitely shown. This result cannot be interpreted but the segregation of sensitive cells occurs in the progeny of infected survival. In other words, it is most conceivable from the characters (multiplicity and slope) of these curves that lysogenic response may be supported by each phage material infected and that the germ supporting lysogenic response may be randomly distributed into the progeny of initially infected cell, during which it does hardly any multiplication themselves. Therofore, it was pointed out that the germ to produce lysogenic state, were different from prophage in character, and pertinent to be referred to as potential prophage.
The author laid emphasis on that prophage is to be established only after the period of potential prophage to be elapsed.

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It has been found that the chloramphenicol is a drug to inhibit protein synthesis selectively. The effect of this drug on various response types of infected bacteria was examined. As a result, it was proved that lysogenic response was largely increased after the exposure for a certain period while lytic response was inhibited strikingly.
Attempt was made to determine at what stage of eclipse addition of this drug was effective to shift to lysogenic response. Consequently, it was shown to be able to intensify the proportion of lysogenic response by the time a little before the end of eclipse period.
The author concluded that the decision of lysogenic response was possible throughout the period of vegetative growth, and that from the standpoint of the kinetics of lysogenization two mechanisms, i.e., decision and establishment, should be regarded separately.

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A strain which is sensitive to the antibodies and insensitive to the non-specific inhibitor in human serum.
16 strains of influenza virus were isolated in Kyushu district 1959 and classified into P, Q phase virus.
There was one strain among them which was sensitive to the antibody of human convalescent serum and insensitive to the non-specific inhibitor in human and horse serum and it was studied principally.
The results were as follows.
1) 16 strains isolated from the outbreak in Kyushu district 1959 were identified as Asian type influenza virus, and 15 isolated strains were P-phase and 1 strain was X-phase.
2) The distribution of P-Q phase virus isolated in Kyushu district from 1957 to 1959 was irregular at each epidemic, but increase of P-phase virus and decrease of Q and X-phase virus were recognized.
3) Haemagglutination of Kumamoto KB-4-59 (X-phase) was inhibited by normal horse serum and HAT titres were irregular at each generation and dilution of inocula but when we subcultured this strain mixing with diluted horse serum (1:100), it became to be not inhibited by normal human and horse serum, and its character was stable until E-13 (13 egg passages).
4) The change of antigenic structure of KB-4 (subcultured with horse serum) was not observed.
5) As KB-4 was not inhibited by inhibitor in human serum, HAT antibody in human serum could be investigated without treatment of the serum with IRE and Sodium periodate.
6) P-Q phase virus were not closely related with cow red cell agglutination.
7) The sensitivity to specific antibodies and inhibitores was not related with CF antigen titre.
8) P-phase virus had the highest immunogenicity of the 3 phase viruses and X-phase virus had higher one than Q-phase virus, when mice were immunized with 3 viruses.

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During the period from February 1957 to July 1958 in Osaka, the author collected 447 fecal specimens (2.4per person) from 190 healthey infants and children under 4 years and 11 months of age who were inoculated with Salk's vaccine; attempted the isolation and typing of enteroviruses on these specimens by using human-embryonic tissue cultures.
The sera were collected from those individuals and tested neutralizing antibodies against entero viruses, particulary ECHO-7 and ECHO-12.
The results are as follows:
1) Sixty-seven strains of enteroviruses were isolated from the feces: fifteen percent of the specimens or 28.9 percent of the individuals examined yielded cytopathogenic agents.
2) The typing of the isolated agents revealed as follows: 13 strains of Echovirus 12 (E-12), 11 strains of E-7, 7 strains of E-6, 5 strains of E-11, 2 strains of poliovirus type II, 5 strains of polio-virus type III and 24 untypable strains (other than poliovirus types I, II, III, E-1, E-2, E-3, E-5, E-6, E-7, E-9, E-11 and E-12) were identified.
3) 62 of 67 strains (92per cent) were isolated from the specimens taken on September and October 1957. Therefore, it is considered that the isolation rates are higher in summer and early fall and lower in winter.
4) As far as the author examined, significant difference of the virus isolation rate was not found among various age groups. The reasoning may be that the age of the examinees was generally young to show such difference.
5) The residences of the virus carriers were located in three provincial districts around Osaka, and the local prevalence was not found in these three areas.
6) Twelve individuals excreted the virus in two specimens taken over a month apart. There-fore, the period of excretion was over 37 days in one instance of E-7 infection, three instances of E-12 infection, and over 51 days in one instance of poliovirus type III infection.
7) The homotypic antibody rise was found in all the carriers of E-12 and 9 of 10 carriers of E-7 viruses. Since the first serum specimens of those individuals showed no antibody to the infected agents, they were considered as primarily infected with such enteroviruses. Three of 45 carriers who excreted the virus other than E-7 and E-12 showed antibody rise against E-12, and one of 42 carriers belonging to the same categorie above showed antibody rise against E-7. The neutralization tests of the sera pooled by age and date of bleeding revealed the prevalence of E-7 and E-12 viruses in September and October 1957 in Osaka area. However, none of the virus carriers and serologically positive cases manifested notable clinical illness, and no epidemic reminded enterovirus infections was found during that period in Osaka.
8) The antibody titers against E-7 virus was compared with those against poliovirus type I on the age specifically pooled sera taken from 602 healthy individuals in Osaka 1955 and 1956. The age which showed higher antibody titers against E-7 was older than that against poliovirus type I, and that the antibody titers of E-7 virus were lower than those of poliovirus type I. Therefore, prevalence of E-7 was considered lower than that of poliovirus type I in the community.
9) The author confirmed from the above experiments that there was widespread inapparent infections of enteroviruses among healthy infants and children in the Japanese urban community, particularly during the summer and early fall.

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Adenovirus was first recovered from tissue cultures of healthy human adenoidal tissue in 1953. The etiological roles of Adenovirus have been elucidated in many human diseases thereafter. On the way of these studies, characteristical features of this virus had attracted a great deal of attention of many investigators. Although many data on these characteristics have been accumulated, many problems still remain to be solved in the future.
This paper reports the results of our experiment which tried to detect the localization of growth site of Adenovirus in HeLa cells by fractionation of the cells into nucleic and cytoplasmic ones. Three fractions obtained, nucleic, cytoplasmic and culture fluid, were titrated their infectivity and complement fixing-antigen successively in time. At the sane time, morphological changes of the infected cells were observed.
Almost the same experiment was independently reported by Ginsberg, but he did not show growth curve of three cellular fractions timmsequentially.
Experimental materials and method: Adenovirus types 1 (Ad, 71) and 3 (G, B) and HeLa cells were used as experimental materials. HeLa cells infected with Adenovirus type 1 or 3 were sequentially fractionated into nucleic and cytoplasmic fractions with treatment of 2.5% citric acid and centrifugation; of these fractions the infectivity and complement-fixing antigenicity were titrated. Paralleled to these procedures, infected HeLa cells, cultured on cover slips, were stained with hematoxylin and eosin after fixation with 95% methanol and observed the morphological changes under a light microscope.
Summary:
1) At the first time, influences of fractionating procedures upon infectivity, complement-fixing antigenicity of Adenovirus and upon HeLa cells themselves were tested. It was revealed that there was no influence of the procedures upon infectlvlty and complement-fixing antigenicity and that loss of number of HeLa cells by such procedures were under 10% of the starting number.
2) Infectivity and comlement-fixing antigenicity in HeLa cells infected with Adenovirus type, 1 or 3 were always higher in cytoplasmic than in nucleic fractions. In all cases, infectivity appeared earlier than complement-fixing antigenicity in both cytoplasmic and nucleic fractions. In fluid phase, infectivity and complement-fixing antigenicity were detected later than intracellular ones, and increased after the time when intracellular antigenicities began to decrease.
3) Morphological changes of HeLa cells infected with Adenovirus type 1 were mostly predominent in the nucleus. According to the sequential features of nucleus, they were classified into first, middle and late stages.

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Salmonella selandia (antigens 3, 15:e, h:1, 7……) and Salmonella Kinshasa (antigens 3, 15:l.z₁₃:1.5……) of group E₂, and Escherichia freundii 4598-53 (antigens 3, 15:z₃₆:-) (Edwards et al., J. Bacteriol. 68, 756, 1954) adsorbed phage ε³⁴, of which genetic materials were injected, but neither cell killing, lysis nor lysogenization was demonstrated. Even after 10 serial passage cultures, no phage multiplication was observed. Temporary appearance of antigen 34 on freshly phage-infected cells indicates that the phage genetic materials are injected into the cells.

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