A nonconjugative R plasmid, rMS3, whose molecular weight was 2.4 × 10⁷ daltons, possessed a kanamycin resistance gene and was thermosensitive in its maintenance in Escherichia coli strains. We mobilized rMS3 with a conjugative R plasmid, R100 or T-tet, and obtained cointegrates carrying all the parental resistance markers. Various markers of the cointegrates were frequently deleted by P1 transduction and the deletion patterns among the different cointegrates were differed from each other. The cointegrates were thermoresistant, but the thermosensitive replicon could be segregated from the thermoresistant cointegrate by deletion. Some cointegrates between rMS3 and T-tet showed a derepressed state of transferability because of the integration of rMS3 into the regulator gene of the transfer loci. The genome size of the cointegrate so far tested was the sum of the sizes of the parental plasmids, indicating that the whole genome of rMS3 could integrate into various sites of the conjugative plasmids R100 and T-tet.

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We have investigated the mechanism of the expression of resistance to high levels of viomycin and coresistance to streptomycin in a mutant strain of Mycobacterium smegmatis ATCC 14468 (AC-13) which was obtained by serial transfers of parental cells to media containing increasing concentrations of viomycin. It was shown previously that resistance to viomycin by strain AC-13 was due to an alteration in the 50 S ribosomal subunit (20). However, genetic analysis has shown that mutation in 50 S subunits alone gave only low level resistance to viomycin. When a streptomycin resistant mutation (caused by an alteration in the 30 S subunit) was introduced into the low level viomycin resistant recombinant strains, most of them were highly resistant to viomycin. Some recombinants were resistant to intermediate levels of viomycin, and the remainder were not affected by the introduction of the str^r allele.
Studies with in vitro cell-free systems have shown that streptomycin resistant 30 S ribosomal subunits obtained from a high level viomycin resistant recombinant were able to modify the levels of resistance to viomycin expressed by the 50 S ribosomal subunit. These findings provide additional evidence concerning the functional relationship between 30 S and 50 S ribosomal components in ribosomes.

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A high level viomycin resistant mutant of Mycobacterium smegmatis ATCC 14468 (AC16) was analyzed genetically and biochemically in an attempt to understand the mechanisms of expression of high level viomycin resistance and co-resistance to kanamycin and streptomycin. Genetic analysis has shown that at least three different genes (vicC, str, and kan) were involved in the phenotypic expression of drug resistance in AC16, and high level resistance to viomycin was due to interactions between the products of these genes.

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Carbohydrate metabolic disorders were investigated by means of enzyme activities in mice (ddYS) injected intraperitoneally with endotoxin from Salmonella typhimurium. The mice exhibited hyperglycemia 2 hr after administration of endotoxin and hypoglycemia at 18 hr. Activity of hepatic phosphorylase in the endotoxin-poisoned mice at 2 hr was slightly higher than that in the control mice, whereas the level of this activity was not significantly different from that in the controls after 18 hr. Glucose-6-phosphatase activity in the poisoned mice increased by 2 hr after injection, but decreased by 18 hr.
The blood lactate level in the poisoned mice transiently decreased until 3 hr after injection, but the mice exhibited a marked lactacidemia by 8-24 hr. The time course of lactate dehydrogenase (LDH) activity in various tissues was examined in mice injected with endotoxin. The activity of hepatic LDH declined to about two-thirds of that of the control mice after 16 hr, and was restored to the normal level by 48 hr. LDH in the cardiac muscle was markedly activated (by about 37 %) in the early period (3-6 hr) after administration of endotoxin, and this activity gradually declined. However, the activity of LDH in the skeletal muscle showed a tendency similar to the rise and fall of the levels of blood lactate, and was restored to the normal value at 72 hr after injection. On the other hand, the serum LDH activity in the poisoned mice increased about 1.75-fold by 16 hr after injection. Mice injected with endotoxin exhibited a leakage of the isozymes LDH 3 and 5, but the origin of the leakage is uncertain. Similar elevation in the activities of transaminases (GPT and GOT) and malate dehydrogenase was found in the mouse serum at 16 hr after injection of endotoxin.

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Bovine parainfluenza virus type 3 (PIV-3) has a buoyant density of 1.197. The RNA of PIV-3, like that of Sendai virus, is a single continuous chain which lacks polyadenylic acid sequences and tends to self-anneal to a marked extent. It has a sedimentation coefficient of 42S and a molecular weight of 4.5 × 10⁶, being slightly smaller than Sendai virus RNA (47S, 5.3 ×10⁶).
PIV-3 has 5 main structural proteins, of which 2 are glycoproteins. The molecular weights of protein₁, protein₂, protein₃, glycoprotein₁, and glycoprotein₂ were estimated to be 79, 000, 68, 000, 35, 000, 69, 000, and 55, 000, respectively. Protein₂ was suggested to be nucleocapsid protein.

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A method for the isolation of mRNA from a c-type virus-positive cell (JLS-V6) has been developed. This method consisted of (i) specific immunochemical precipitation of polyribosomes synthesizing viral proteins, (ii) extraction of the mRNA from the polyribosome/antigen/antibody complex, and (iii) separation of poly-A containing RNA by affinity chromatography on oligo-d (T) -cellulose. Three size classes of virus specific poly-A containing mRNA are identified and they are 35S, 20S-25S, and 10S-15S.

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A hemagglutinating agent was isolated from the respiratory organs of budgerigars suffering from diarrhea and malnutrition. This agent, possessing neuraminidase activity, was identified as influenza A virus by the double immunodiffusion test.
The results of hemagglutination and neuraminidase-inhibition tests with monospecific antisera to the isolated surface antigens showed that the isolates possessed Hav4 hemagglutinin and Nav 1 neuraminidase subunits both of which were closely related to the corresponding antigens of A/duck/Czech/56 (Hav4 Nav 1).

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Effect of nucleosides both on induction of antiviral state in chick embryo cells (CEC) or rabbit kidney cells (RK13) and on interferon production in RK13 or mouse fibroblast cells (L cells) by polyriboinosinic-polyribocytidylic acid (poly I · poly C) was studied. Addition of inosine or a fifty-fifty mixture of inosine and uridine at a final concentration of 0.1 mM to 10 mM to a growth medium enhanced development of antiviral state in CEC. The nucleoside effect was also observed in RK13 at 0.1 mm but not at a concentration higher than 1 mM. Interferon production in RK13 by superinduction (sequential treatment with metabolic inhibitors after exposure to poly I · poly C) was enhanced 1.5- to 4.0-fold by addition of the nucleoside mixture to the growth medium. When RK13 was pretreated with 10 units per ml of interferon and then superinduced by inhibitors, the enhancing effect of nucleosides on interferon production was not observed. Interferon production in L cells was potentiated a little by addition of 1 mM of the nucleoside mixture to the growth medium. The effect of nucleoside was not observed when the nucleosides were added after exposure to poly I ·poly C. The nucleoside effect may be applicable for production of high titered interferon.

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In order to elucidate the antigenic structure of poliovirus, the reactivity of antibody produced with H antigenic particles of Mahoney strain (polio type 1) was investigated.
Injection of H particles of Mahoney strain into rabbits yielded neutralizing antibody as well as CF-N and CF-H antibodies. This result coincided with the report by Hinuma and coworkers. Neutralization tests with inhibitor resistant Mahoney mutants revealed that the neutralizing antibody produced with H particles was of HN31 type, one of the five different kinds of polio neutralizing antibodies reported previously (14). Absorption experiments with H particles on different neutralizing antibodies and analysis of antibody eluted by acid dissociation from antiserum-treated H particles also showed that the HN31 type antibody specifically combined with H particles ofMahoney strain.
Since the H particle of poliovirus is known to be deficient in VP4, these results seems to indicate that the HN31 type antibody reacts with a structural part (s) of poliovirus other than VP4.

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The present report describes not only the effects of tannic acid (TA; belonging to hydrolyzable tannins) and its related compounds upon the infectivity of Chikungunya virus (CHIKV) but also the mechanism involved in this phenomenon. Our data show that TA inactivates CHIKV in vitro. Since the inactivating effect turned out to be pH-dependent and was suppressed by bovine serum albumin, it is most probable that the virus-inactivating capacity of TA is attributable to its preferential binding to proteins of virus particles. Examination on the virus-inactivating capacities of some TA-related compounds and comparison of their structures indicated that the active site of TA and its analogues might be the phenolic hydroxyl groups in their molecules. It seems that the active groups interact with the proteins of virus particles, resulting in a reduction or loss of viral infectivity. Discussion is made on the specificity of the actions of tannins and the possibility of application thereof to chemicals which are useful to investigate the nature and properties of viral proteins.

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A factor that decreases rosette formation between guinea pig T-cells and rabbit red blood cells (RRBC) was extracted from the thymus of the guinea pig.
The active factor could be extracted from the spleen as well as the thymus, but not from the liver or kidney. The active factor of the thymic extract was found in the precipitates produced by 80% saturated ammonium sulfate and it was separated from the water-soluble fraction of the precipitates. The molecular weight of the partially purified substance was estimated to range between 10, 000 and 30, 000 by filtration through a diaflow membrane.
From the studies on physicochemical characterization, it might be a heat-resistant basic peptide probably bound to a ribonucleotide moiety. This factor reduced rosette formation between RRBC and guinea pig T-cells, but did not reduce erythrocyte-antibody-complement rosette formation.
This factor also inhibited mitogen (concanavalin A, phytohemagglutinin-P) -induced DNA synthesis of guinea pig lymphocytes and antigen-induced DNA synthesis of sensitized guinea pig lymphocytes.

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