An extract of Candida albicans isolated from a patient with typical mucocutaneous lymph node syndrome (MCLS) can produce coronary arteritis in a mouse when injected intraperitoneally. An unusual feature of this arteritis is that it is granulomatous, shows no fibrinoid change and is confined to the coronary arteries. These characteristics are quite similar to those found in patients with MCLS.

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'Tween egg medium, ' in which Tween 80 was used as a carbon source, showed a higher rate of positive cultures than Ogawa egg medium in isolation of mycobacteria from sputum specimens.

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In vitro cholic acid (CA) transformation by mixed fecal culture was investigated. Concentrations of glucose, peptone, and yeast extract in the medium and the initial pH of the medium markedly affected the CA transformation. Yeast extract enhanced the transformation, whereas high concentrations of glucose and peptone inhibited it. When the initial pH of the medium was below 6.5, CA was converted to 7-keto-deoxycholic acid (7KD), and formation of deoxycholic acid (DC) was not observed. In contrast, with an initial pH of 7.0, about 60% of the CA was converted to 7KD after 3 days of incubation, and then DC gradually formed after 4 days of incubation, following the disappearance of 7KD. The formation of DC in the cultured samples was paralleled in each case by disappearance of 7KD. In pure culture systems, Escherichia coli and some strains of Bacteroides formed 7KD from CA. No DC formation was observed in pure cultures of any of the strains examined.

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Plaque-forming ability and cariogenic virulence of Streptococcus mutans AHT mutants having varying in vitro adherence abilities were studied in hamsters reared on a high sucrose diet over a period of 64 days. The parent wild-type strain produced heavy plaque and extensive carious lesions on molars. However, mutants M1, M2, and M13, which have lost the ability to form adhesive deposits on glass when grown in sucrose broth, and mutant M9, which adheres firmly to glass but in an extremely small amount, could not be recovered from the mouths of animals even after repeated inoculations at weekly intervals throughout the experimental period. Mutant M35, which produces a large amount of loosely adhering deposits in vitro, became established and persisted on molars, but its recovery was extremely low. None of the mutants, including M35, significantly produced plaque and caries in hamsters. Possible causes of this inability to form plaque and the avirulence of mutants are discussed.

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The antigenic characteristics of enterovirus type 70 (EV 70) were investigated by means of cross and kinetic neutralization tests (NT). Twelve strains of EV 70 isolated in a period from 1971 to 1976 were analyzed using seven rabbit and one monkey hyper-immune sera. All the strains investigated were found to possess a common and prime variant antigens in varying proportions.
Accordingly, EV 70 isolates were divided intratypically into three antigenic subgroups; (1) prototype-like (four strain from 1971 to 1972), (2) intermediate, G-10/72-like (two strains from 1972 to 1973), and (3) prime variant, G-2/74-like (six strains from 1974 to 1976) groups.
Thus it was considered that EV 70 might represent a virus type with antigenic heterogeneity, and that antigenic drift from the prototype to the prime type may have occurred successively after 1971.

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In order to demonstrate the stability and continuity of RNA coliphages (phages) in their natural habitats, we investigated the amount and group types of RNA phages in sewage samples collected continuously from domestic drainage in Japan proper and islands in the seas adjacent to Japan (abbreviated simply as islands, hereafter) over a 5-yr period from 1973 to 1977. It was found that the frequencies of isolation of RNA phages were fairly high and constant. The group types of RNA phages isolated were also stable in the three cities, Choshi, Niigata, and Toyama in Japan proper. The average for the three cities was group II : III= 3 : 1. The investigation in islands revealed that the frequencies of isolation of RNA phages were fairly high as in the case of the above three cities in Japan proper and the group types of RNA phages isolated were also stable. That is to say, group II phages were predominant on Rishiri Island, Rebun I., Iki I., and Tsushima I., which are located relatively near to mainland Japan, while group III phages were predominant on Amamiohshima I., mainland Okinawa, Ishigakijim I., and Iriomotejima I., which are located south of Kyushu. It can thus be said that the RNA phages in the domestic drainage of Japan proper and islands remained more or less stable over at least the 5-yr period, and an apparent difference in the geographical distribution of RNA phages in Japan exists between Kyushu and Amamiohshima I.

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By the aid of freezing and thawing, cell-free infectious virions were detected from an apparently nonproductive Vero cell line infected with Niigata- 1 strain of subacute sclerosing panencephalitis virus. The production of infectious virions was limited in amount and such virions were detectable only during a limited period after cell subculture. The infectious virions were filtrable through a 0.65μ membrane filter and neutralized completely by an antiserum against measles virus. The virions were banded at the density of 1.132, while Edmonston strain of measles virus banded at 1.164 in potassium tartrate density gradients. Infectious virions were also released from infected Vero cells by treatment of the cells in a hypotonic solution to an amount comparable to that obtained by freezing and thawing. Infection of normal culture of Vero cells with the infectious virions readily established a virus-cell interaction identical to that in the original infected culture from which the virions were recovered.

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The antigenic differences among human cytomegalovirus (CMV), two laboratory strains (Davis, AD 169), isolates from pregnant women's cervical secretions, mother's milk, infants' throat swabs and urine were analyzed by means of the plaque reduction assay using human sera which were assumed to contain monotypic antibodies by primary infection and boosted antibodies by reinfection or reactivation of the latent virus. In the cross-neutralization tests, there were no remarkable differences among the CMV strains examined. Moreover, in the neutralization kinetics, normalized k values among the strains constantly exceeded 80. Therefore, it is suggested that the human CMV strains examined in the study were serologically identical or very closely related.

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The function of thymus-dependent lymphocytes (T lymphocytes) was studied in women during pregnancy and labor and postpartum by evaluating the blastogenesis of peripheral lymphocytes, which were stimulated with phytohemagglutinin-P (PHA-P) in both whole-blood semimicroculture and purified lymphocyte culture. Data from 353 random samples (203 women) and 50 serial specimens from 10 women revealed that PHA-P induced-lymphocyte blastogenesis was significantly (p<0.005) reduced during pregnancy and labor but rapidly returned to normal several days after artificial termination in the early stage of pregnancy as well as after full-term delivery. These results indicate that the T-lymphocyte function in maternal peripheral blood is depressed by causes related to pregnancy. It seems very likely that depressed T-lymphocyte function during pregnancy is caused by inhibitory factors in the blood plasma derived from the feto-placental unit. Questions relating to the inhibitory factors in maternal plasma are discussed.

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