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Volume 25, Issue 4
Displaying 1-9 of 9 articles from this issue
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Shozo URASAWA1975 Volume 25 Issue 4 Pages 213-219
Published: December 30, 1975
Released on J-STAGE: March 16, 2010
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Kozaburo HAYASHI1975 Volume 25 Issue 4 Pages 220-236
Published: December 30, 1975
Released on J-STAGE: March 16, 2010
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I. ISOLATION OF AHC VIRUS FROM CONJUNCTIVAL SCRAPINGS, THROAT SWABS AND FECES OF PATIENTSNakao SAKURAI, Hakaru NISHIOKA, Hideshige YOSHIKAWA, Toshiro SHIOMI, S ...1975 Volume 25 Issue 4 Pages 237-241
Published: December 30, 1975
Released on J-STAGE: March 16, 2010
JOURNAL FREE ACCESSOver a period of four months from September to December in 1972, acute hemorrhagic conjunctivitis (AHC) was prevalent in the Kuwana area of Mie Prefecture. An attempt was made to isolate AHC virus from 111 patients in the monkey kidney cell culture. The isolation rates from conjunctival scrapings, throat swabs, and feces were 25.2%, 5.1%, and 3.8%, respectively. An optimal temperature was 33°C for the propagation of AHC virus. Some strains were grown well at 37°C, as well as at 33°C. On the basis of these results, it is quite probable that the infection of AHC virus is generally transmitted from feces to mouth in nature, as well as that of common enterovirus.View full abstractDownload PDF (756K) -
Kenkichi SHINKAI, Takuzo NISHIMURA1975 Volume 25 Issue 4 Pages 242-246
Published: December 30, 1975
Released on J-STAGE: March 16, 2010
JOURNAL FREE ACCESSThe efficiency of filtration of various viruses was compared between cellulose acetate membrane (CAM) and cellulose nitrate membrane (CNM). In addition, studies were made on the effects of virus diluents and pretreatment of these membrane filters on the filtration of various viruses. The results obtained are summarized as follows.
(1) Herpes simplex virus (HSV), vesicular stomatitis virus (VSV), and influenza virus diluted in phosphate-buffered saline (PBS) or Eagle's minimum essential medium (MEM) were adsorbed completely to untreated CNM. Therefore, no infectivity was detected in the filtrate of any virus. When HSV, VSV and influenza virus diluted in the above-mentioned diluents were filtered through untreated 0.45μ CAM, the viral infectivity recovered in the resulting filtrate was about 45, 75, and 75%, respectively.
(2) When HSV, VSV and influenza virus were diluted in PBS containing 0.1% egg-yolk or in MEM supplemented with 2% calf serum and filtered through untreated CAM or CNM, there was an increase in the amount of recovery of these viruses.
(3) When CAM and CNM were pretreated with 1.3 to 5% calf serum or 0.25 to 1% polyvinylpyrrolidon (PVP), they were prevented from adsorbing HSV, VSV and influenza virus, and the recovery of viral infectivity was increased in the filtrate through each membrane.View full abstractDownload PDF (741K) -
Koichi TAKEHARA, Tadao MITSUI, Kanematsu FUKUSHO, Junji NAKAMURA1975 Volume 25 Issue 4 Pages 247-252
Published: December 30, 1975
Released on J-STAGE: March 16, 2010
JOURNAL FREE ACCESSThe peripheral susceptibility of hamsters was compared with the peripheral and intracerebral susceptibility of mice by using the AT31 strain of Japanese encephalitis virus, which has a strong peripheral infectivity. The results obtained are summarized as follows.
1) In hamsters inoculated intracardiacally with 300 ic LD50 for mice of the virus, the virus appeared in the blood 12 hours after inoculation (a. i.), reached the highest level (102.68PFU/ml) 2 days a. i. Then it decreased to a certain level where it remained up to 4 days a. i. In mice inoculated intravenously, the virus reached the highest level (101.91PFU/ml) 1 day a. i. and decreased after that to disappear from the blood 4 days a. i. Neutralizing antibody appeared in the blood of both hamsters and mice 3 days a. i.
2) Hamsters showed a very high peripheral susceptibility. In them, infection was established by inoculation even with a dose less than 1 LD50 for mice, and hemagglutination-inhibition antibody of high titer was produced. Almost all the hamsters inoculated were involved in latent infection, presenting a good contrast to the inoculated mice which exhibited a high fatality rate.
3) The typical histological changes of encephalitis in the brains were observed in almost all the hamsters infected.View full abstractDownload PDF (847K) -
I. OCCURRENCE OF STILLBIRTH AND ABORTIONKoichi TAKEHARA, Tadao MITSUI, Kanematsu FUKUSHO, Masafumi ITABASHI, H ...1975 Volume 25 Issue 4 Pages 253-260
Published: December 30, 1975
Released on J-STAGE: March 16, 2010
JOURNAL FREE ACCESSStillbirth and abortion caused by Japanese encephalitis virus in swine inflict a great damage upon animal husbandry. The present experiment was carried out to induce disorders similar to them in small laboratory animals. Pregnant mice and hamsters were inoculated with the AT31 strain of the virus, which has a strong peripheral infectivity. The following results were obtained.
1) Stillbirth and abortion were induced in hamsters at a high frequency, but not in any mouse, at all.
2) The rate of occurrence of these disorders was the highest in animals inoculated at 5 days of pregnancy. The later the virus was inoculated into animals, for example, at 7 or 10 days of pregnancy, the lower became this rate.
3) Abnormal infants were classified into stillborn ones, week ones, and infants which became ill soon after birth.
4) Fetal infection was clearly recognized when animals were subjected to laparotomy immediately before parturition and examined for the numbers of dead embryos and dead fetuses in relation to the total number of implanted eggs.
5) The virus was demonstrated in those abnormal infants at a high frequency. It showed a high titer. It was detected not only from the brain but also from the rest of the body. The virus titer of the brain was at the same level as that of the rest of the body.
6) The typical histological changes of encephalitis were observed in the brains of infected fetuses and newborn infants.
These results indicate that a pregnant hamster can be used as a model system for studies on stillbirth and abortion caused by Japanese encephalitis virus in swine. Accordingly, they paved the way to evaluation of the preventive effect of vaccine.View full abstractDownload PDF (4368K) -
II. PREVENTION OF STILLBIRTH AND ABORTION BY IMMUNIZATIONKoichi TAKEHARA, Tadao MITSUI, Junji NAKAMURA1975 Volume 25 Issue 4 Pages 261-268
Published: December 30, 1975
Released on J-STAGE: March 16, 2010
JOURNAL FREE ACCESSStillbirth and abortion can be induced in hamsters at a high frequency by peripheral intracardiac inoculation with Japanese encephalitis virus. In the present experiment hamsters were conferred with immunity of varying degrees beforehand to examine the relationship between the degree of immunity and the frequency of occurrence of stillbirth and abortion. The results obtained are summarized as follows.
1. Hamsters immunized with live virus. (1) When inoculated with live virus, all the animals produced such a high titer of hemagglutination-inhibition antibody as 1:160-1:320. (2) In the immunized group, no animals (0/9) were involved in stillbirth or abortion when challenged by virus inoculation. The average number of young per litter was 8.6 In the unimmunized control group, stillborn and aborted young were seen in all the animals (9/9). The average number of young, including stillborn and aborted ones, per litter was 2.8.
2. Hamsters immunized with inactivated virus. (1) When three different concentrations of vaccine, high, moderate, and low, were used for immunization, antibody was produced positively in 12/12, 11/16, and 1/14 animals of the three groups, respectively. (2) The rate of occurrence of fetal infection by challenge inoculation was 0% (0/8), 55.6 (5/9), 100% (6/6), and 100% (6/6) in these three immunized groups and the control group, respectively.
3. Relationship between antibody titer and obstetrical disorders. Throughout the present experiment the rate of occurrence of stillbirth and abortion or fetal infection was 0% (0/11) in animals in which the neutralizing antibody titer (the rate of reduction of plaques formed in 1:20 dilution of serum) before challenge inoculation was more than 77, 50% (1/2) in animals in which the titer was 55, and 100% (10/10) in animals in which the titer was less than 47.
These results made it clear that no fetal infection could be established in an animal which had antibody in the blood to some extent.View full abstractDownload PDF (1111K) -
1975 Volume 25 Issue 4 Pages 269-273
Published: December 30, 1975
Released on J-STAGE: March 16, 2010
JOURNAL FREE ACCESSDownload PDF (636K) -
1975 Volume 25 Issue 4 Pages 274-281
Published: December 30, 1975
Released on J-STAGE: March 16, 2010
JOURNAL FREE ACCESSDownload PDF (1298K)
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