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Biomedical subjects

R Kono

Publications and source records attributed to R Kono.

At least 73 records · Page 4Linked to original sources
PubMed1978

Growth characteristics of acute hemorrhagic conjunctivitis virus in monkey kidney cells. III. Viral RNA synthesis at permissive and nonpermissive temperatures.

Monkey kidney cells infected with the J 670/71 strain of acute hemorrhagic conjunctivitis (AHC) virus in the presence of actinomycin D synthesized two species of viral RNA. One species had properties similar to the virion RNA, sedimented in a sucrose gradient with a sedimentation coefficient of 34S, and was sensitive to RNase. The other species sedimented at 18S and was resistant to RNase. The inability of AHC virus to replicate at 39 degrees was attributed to a lack of virus-specific RNA synthesis in infected cells.

Animals↗
PubMed1978

Optimal conditions for plaque assay of echoviruses in human embryonic lung fibroblast cells.

The present paper gives optimal conditions for plaque assays tn human embryonic lung fibroblast cells with 45 echoviruses including 11 fresh isolates, covering 31 serotypes. All the viruses tested except echovirus type 23 produced plaques at a high titer in the same cells by the methods described in this communication. Plaque formations by a number of strains were markedly enhanced in size or number or both by the addition of polycation.

Cell Line↗
PubMed1977

Microcephaly with peculiar demyelination mimicking Pelizaeus-Merzbacher disease.

The neuropathological studies of a 4-year old idiot with microcephaly revealed a striking demyelinating disease compatible with Pelizaeus-Merzbacher disease. The case seemed to be best classified as the patchy demyelination type, but the most unusual finding was a prominent vasculature in some demyelinated areas. Intrauterine hypoxia was proposed as a causative factor of this type of demyelinative lesions.

Autopsy↗
PubMed1977

Virological and serological studies of neurological complications of acute hemorrhagic conjunctivitis in Thailand.

An extensive outbreak of acute hemorrhagic conjunctivitis (AHC) occurred from September to December 1974 in Thailand. At least 29 patients with polio-like motor paralysis that complicated AHC were hospitalized in Bangkok. Paired or triplicate samples of serum from 16 patients were tested for neutralizing antibody to enterovirus type 70 (EV70). A significant rise in titer of antibody was found for two patients, and the other 14 had neutralizing antibody titers ranging from 1:8 to 1:512 without an increasf larger than or equal to 1:16, a level which is considered to be diagnostically significant. Neutralizing antibody to EV70 was detected in 19S fractions of nine sera examined, but neutralizing antibody to three types of poliovirus was confined to 7S fractions. EV70 was isolated from one of seven stool specimens collected on day 37 after the onset of AHC and none of 10 samples of cerebrospinal fluid. These results and additional clinical and epidemiologic findings gave further support to the hypothesis that EV70 infection can cause polio-like motor paralysis as a complication of AHC.

Antibodies, Viral↗
PubMed1977

Replication of enterovirus 70 in non-primate cell cultures.

Replication of the strain J 670/71 of enterovirus 70 (EV70) in non-primate cell cultures at 33 degrees C was studied using strain L (mouse), BHK21 (hamster), RK13 (rabbit), RK17 (rabbit), PK15 (porcine), IB-RS-2 (porcine), ESK (porcine), MDBK (bovine), and BK1 (primary bovine) together with that of the LSc, 2ab strain of poliovrus type 1 (PV1) as a control. All the cells tested adsorbed from 54 to 90% of EV70. The replication with complete c.p.e. was evident in RK13, RK17 and BK1 cells; replication without c.p.e. was shown in L, BHK21, IB-RS-2 and ESK; but PK15 and MDBK were non-permissive despite a high virus adsorption rate. On the contrary, none of these non-primate cells allowed the adsorption and growth of PV1. One-step growth of EV70 in RK13 was almost identical with that in the primate cells. Two other strains of EV70 were found having similar host range in vitro. Therefore, it is concluded that EV70 has a wider host range in vitro than ordinary human enteroviruses, and its implication is discussed.

Adsorption↗
PubMed1977

Morphological observation of idiopathic cardiomyopathy consisting of 9 cases encountered in sudden and unexpected death.

The present study consists of 9 cases of idiopathic cardiomyopathy which were divided into two types, i.e. 6 cases of the hypertrophic type and 3 cases of the dilated type. The former type was found in school-children and relatively younger adults, and the latter in various ages. In both types the hearts showed marked enlargement. The characteristic gross changes of the hypertrophic type were hypertrophy of the anterior wall of left ventricle and of the ventricular septum. Microscopically, the hypertrophied myocardium demonstrated a bizarre arrangement showing different size and shape of muscle fibers. In addition, the wall of small arteries and arterioles revealed circumscribed elastosis here and there. In the dilated type, the hearts showed marked dilatation of both ventricles, and microscopy revealed coagulation necrosis of the myocardial fibers and marked scar formation with slight inflammatory cell infiltration. The gross and microscopic changes in both types of idiopathic cardiomyopathy differed from one another in several respects, and the authors assumed that the differences indicate an independent etiology of both types in man.

Adolescent↗
PubMed1977

Antigenic relationship between human and bovine rotaviruses as determined by neutralization, immune adherence hemagglutination, and complement fixation tests.

Guinea pig antiserum to bovine rotavirus does not neutralize human rotavirus. Bovine and human rotaviruses were, however, extensively cross-reactive when examined by complement fixation and immune adherence hemagglutination tests with antiserum to either virus. The immune adherence hemagglutination test was 16- to 32-fold more sensitive than the complement fixation test in detecting rotavirus.

Animals↗
PubMed1977

Plaque assay of neonatal calf diarrhea virus and the neutralizing antibody in human sera.

Neonatal calf diarrhea virus (a bovine rotavirus) formed distinct plaques in monolayers of MA-104 cells, an established macacus rhesus monkey kidney cell line, when diethylaminoethyl dextran and trypsin were included in the overlay medium. By using this plaque assay method, titration of neutralizing antibody to neonatal calf diarrhea virus was made feasible. It was demonstrated that some human sera contained neutralizing antibody to this agent.

Animals↗
PubMed1977

Establishement of a rabbit lung cell line (RL-33) and its viral susceptibility.

A new cell line (RL-33) was established from a rabbit lung tissue. The cells maintained a fibroblastic appearance and a contract-inhibited growth through 180 passages. No latent infectious agent has so far been demonstrated. The cells supported the growth of a variety of viruses, enabling plaque assays for Shope fibroma, rabbit myxoma and types 1 and 2 herpes simplex viruses. They were as sensitive to rabbit interferon as RK-13 (a line from rabbit kidney) cells.

Animals↗
PubMed1976

Growth characteristics of acute hemorrhagic conjunctivitis (AHC) virus in monkey kidney cells. II. Temperature sensitivity of the isolates obtained at various epidemic areas.

Acute hemorrhagic conjunctivitis (AHC) virus strains isolated in eight different areas during epidemics of AHC were tested for the reproductive capacity at 33, 37 and 39 degrees. All of the 25 strains tested grew better at 33 degrees but restrictively at 39 degrees. The degree of temperature sensitivity varied slightly from one strain to the other, but generally exceeded that of attenuated poliovirus type 1, strain LSc2ab. Temperature-resistant clones were selected by repeated passages of originally temperature-sensitive prototype strains at supraoptimal temperature. The importance of using a low temperature (32-34 degrees) for isolation of virus from external tissues of the body and for subsequent passages has been emphasized. It was suggested that the relatively low temperature of the conjunctiva has played a role in perpetuating temperature sensitivity of this virus.

Animals↗
PubMed1976

Rubella vaccination.

Various attenuated live rubella vaccines now in use are considered generally safe and immunogenic, but to date the longest that vaccinal immunity has been shown to endure is seven years. Subclinical reinfection is not uncommon among vaccines, but its effect on pregnancy and fetal development is not yet fully known. At present two mass immunization strategies are used: vaccination of all children under 12 years of age or protection only of females 10-14 years of age. In either case susceptible women of childbearing age who have no detectable rubella HI antibody are immunized as well. Such women may receive the vaccine during the postpartum period or at any other time when they are not pregnant, but strict precautions must always be taken to make sure they do not conceive for at least two months thereafter.

Adolescent↗
PubMed1976

Enteroviruses other than poliovirus.

The role of enteroviruses in certain specific disease--cardiac disease, nephritis, diabetes, and hemorrhagic conjunctivitis--is examined. It has now been well documented that Coxsackievirus B (types CB1 through CB5 but not CB6) is the main pathogen involved in various clinical forms of viral heart disease. Coxsackievirus A (CA4 and CA16) and echovirus (types 9 and 22) may also be associated with viral heart disease. In regard to the etiologic role of enteroviruses in nephritis, pancreatitis, and diabetes, again CBV, especially CB3 and CB4, has been suspected, but the data are controversial and further studies are needed. Hemorrhagic conjunctivitis, a newly observed clinical entity, is caused by enterovirus 70. It has spread to four continents (not including the Americas) in a pandemic fashion since 1969 and is now one of the common eye infections in these areas. The virus has some neurovirulence, and motor paralysis is known to occur as a complication; hence it should be carefully watched in the future.

Animals↗
PubMed1975

Serologic characterization and sero-epidemiologic studies on acute hemorrhagic conjunctivitis (AHC) virus.

Serologic and sero-epidemiologic characteristics of AHC virus infection were studied by neutralization test (NT). Four-fold or greater virus neutralizing (VN) antibody response was demonstrated to the Japanese isolate of AHC virus (the J 670/71 strain) in 77.3% and 66.7% of paired sera from clinical AHC patients in Japan (1971-1973) and Tunisia (1973). The four patients from Indonesia studied in 1972 showed similar antibody response. Cross-neutralization tests of AHC virus isolated in Japan (1971), Taiwan (1971), Hong Kong (1971), Thailand (1972), Indonesia (1972), Singapore (1972), Morocco (1971) and England (1971) with three kinds of antisera prepared against Japanese, Hong Kong and Moroccan AHC virus isolates indicated their antigenic identity. However, isolates from Sinapore in 1970 (Singapore 70 virus) were not neutralized with the AHC virus antisera mentioned above: Singapore 70 virus constitutes another antigenic type, to which, however, no VN antibody rise was found in paired patients' sera from Japan, Tunisia and Indonesia. Thus, no serologic evidence supporting an etiologic role of this virus group in the development of AHC was found. Although cross-tests using monospecific antisera suggested some cross-relation between AHC and both echovirus type 4 (E4) and coxsackie A (CA), type 19, no serologic relationship between AHC and these viruses was found. Sera from healthy individuals collected before and after AHC outbreaks were tested for VN antibody against AHC virus in Japan and two epidemic foci, Ghana and Indonesia. Before the epidemic, 80 to 90% of the people lacked antibody in the three countries, but 39.7% and 45.2% of inhabitants posessed VN antibody of 1:8 or over in Ghana and Indonesia after the outbreak. In Japan, however, only a slight increase was found in VN antibody prevalence afterwards. Serologic study showed that 41.5% of horse sera were VN positive at dilutions of 1:8 or more; many cattle sera also had a low VN titer but few cynomologus monkey sera had VN activity.

Acute Disease↗