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Biomedical subjects

R Kono

Publications and source records attributed to R Kono.

At least 19 recordsLinked to original sources

Prevalence of antibody to hepatitis A virus in Sri Lanka.

Antibody to hepatitis A virus was studied by immune adherence hemagglutination using 287 serum specimens collected in 1975 by random sampling from healthy individuals living in Colomobo, Sri Lanka. The overall prevalence of antibody to the virus was 76.9% and the prevalence between males and females was approximately the same. The age-specific prevalence of the antibody indicated that hepatitis A in the area is mainly an infection during the early childhood.

Adolescent

Differential inhibitory effects of 5-bromodeoxyuridine on vaccinia and monkeypox viruses.

Replication of vaccinia and monkeypox viruses was impeded in the presence of 5-bromodeoxyuridine (BUdR) in RL-33 cells derived from rabbit lung tissue. The different degree of inhibition was found among strains of those viruses, in which it was evident that five strains (CV-1, Lister, IHD, Dairen-I and Ikeda) of vaccinia viruses resulted in more reduced yields of infectious virus than four strains (Sen-19, Orang Utan, Copenhagen and Sierra Leone) of monkeypox viruses. There was also strain variation in BUdR sensitivity within vaccinia viruses but not in the case of monkeypox viruses.

Bromodeoxyuridine

Four autopsy cases of neonatal giant cell hepatitis died suddenly and unexpectedly from intracranial hemorrhage.

The authors present four cases of neonatal giant cell hepatitis who died suddenly and unexpectedly from intracranial hemorrhage, autopsied recently at the Tokyo-to Medical Examiner Office. This series consisted of one male and 3 female infants ranging from 37 to 52 days of age. The cause of death of all cases was thought to be massive intracranial hemorrhage. Referring to the connection between intracranial hemorrhage and neonatal giant cell hepatitis, it was assumed that the former must have occurred due to the hemorrhagic tendencies of the latter, superimposing to the hemorrhage at birth trauma of the head. As to the formation of multinucleated giant cell, it is considered to be of degenerative nature of hepatocytes, i.e. the giant cell is formed by fusion of hepatocytes as a result of the disappearance of bile canaliculi, although the etiology of this hepatitis is still unknown.

Brain

Oligomeric immunoglobulin A antibody response to rubella virus infection.

Pooled sera from rubella patients in the early convalescent stage, containing a high titer of hemagglutination-inhibiting (HI) antibody, were treated with protein A-conjugated gel to reduce immunoglobulin G (IgG) antibody and then centrifuged in sucrose gradients. This treatment resulted in the detection of an HI activity peak sedimenting at a rate intermediate between 7S and 19S. In contrast to the 19S antibody, the HI activity of this peak was not abolished by 2-mercaptoethanol, but sedimented at 7S after this treatment. The activity was considered to consist of IgA oligomers, since it was removed by anti-IgA immunosorbent. The appearance of the oligomeric IgA antibody after the infection was then studied using serum samples collected sequentially from five rubella patients. Shortly after the onset of the disease, the HI activity appeared at high titer and thereafter gradually decreased in titer until it could no longer be detected in the sera. The time of its disappearance varied with each patient.

Antibodies, Viral

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

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

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

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

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

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

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

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

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

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