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Biomedical subjects

R Mori

Publications and source records attributed to R Mori.

At least 181 records · Page 10Linked to original sources
PubMed1981

Experimental transmission of Creutzfeldt-Jakob disease.

Tissues taken from 10 patients with Creutzfeldt-Jakob disease (CJD) were inoculated to many species of small rodents and primates. Successful transmission was done from 9 patients with a varied incidence after different incubation periods. After the second passage, the incidence became high and incubation periods were reduced approximately to four months in mice. Squirrel monkeys needed the longest incubation period in our experiments. Intracerebral inoculation was the fastest route of transmission followed by other parenteral and oral routes. Spongiform change and gliosis in the CNS were common pathological changes, though their distribution was peculiar to each animal species. The distribution in mice differed with each inoculated material taken from the patients, suggesting the multiplicity of CJD agents. Unconventional properties of the causative agent disclosed through this animal model were discussed.

Administration, Oral↗
PubMed1980

Infantile digital fibromatosis. Ultrastructural, histochemical, and tissue culture observations.

Three cases of infantile digital fibromatosis were studied by electron microscopy, enzyme histochemistry, and tissue culture. The tumors were made up equally of myofibroblasts containing electron-dense inclusions which were composed chiefly of microfilaments measuring about 5 to 7 nm. Dense bodies usually observable in the smooth muscle cells were found in the bundles of these microfilaments and in the process of the inclusions, suggesting that these inclusions may represent an abnormal accumulation of contractile protein in the cytoplasm of tumor cells. Two cell lines were established from culture of the tumor cells, and the cultured cells also contained inclusion bodies showing the same morphologic characteristics as those of the original tumor cells. Lysosomal enzymes were abundant in the cultured cells, but they were scant in the cells of the fresh tissue specimens. Cocultivation of the cultured cells with human embryonic lung cells yielded no cytopathic effect.

Acid Phosphatase↗
PubMed1980

Tubular structures in the cervix of mice experimentally infected with herpes simplex virus type 2.

Experimental infection of the C3H/N mouse genital tract was demonstrated after intravaginal inoculation with herpes simplex virus type 2 (HSV-2). About 75% of the infected animals died by Day 7, and 75% of the surviving animals had severe vaginitis or neurological signs on Day 7. Titers of the virus recovered from vaginal secretions of infected animals reached a maximum on Day 2 and gradually decreased until Day 7. On the other hand, under the electron microscope, virus particles and tubular structures could be found in the nuclei of infected cells of the cervix in the 1st, 2nd and 4th days after infection. All cases in which virus particles could be found in the nuclei of infected cells were also positive for tubular structures and vice versa. These observations indicate that in situ diagnosis of HSV-2 infection can be made in the mouse model. The same method would be applicable for the diagnosis of human HSV-2 infection.

Animals↗
PubMed1980

Cell culture of infantile digital fibromatosis.

Two cell cultures were obtained from excised tumors of two cases of infantile digital fibromatosis (IDF). The cells had eosinophilic cytoplasmic inclusion bodies characteristic of IDF. Although the rate of cells bearing the inclusion bodies was high at the earlier passage levels, it was reduced to zero by the 15th passage of one of the cultures, but the cells of the other culture continued to produce the inclusion bodies even at the 30th passage. Chromosome analysis revealed both cultures to have tetraploid cells in approximately 8 to 12% in late passage levels. No viruslike particles were found in electron microscopy. No tumors developed when the cells were inoculated into athymic, nude mice subcutaneously. These cell cultures will be valuable for characterizing the eosinophilic inclusion bodies and determining the origin of the tumors.

Animals↗
PubMed1980

Macrophage activation by muramyl dipeptide as measured by macrophage spreading and attachment.

A synthetic bacterial cell wall constituent, muramyl dipeptide (MDP), was found to induce the enhancement of macrophge spreading and attachment on glass or plastic surfaces. Macrophages exposed to bacterial lipopolysaccharide or lymphokine-containing cell supernatants showed similar enhancement. This finding supports the view that MDP activates macrophages. MDP was also found to enhance the viability of macrophages but to inhibit 3H-thymidine incorporation by macrophages.

Acetylmuramyl-Alanyl-Isoglutamine↗
PubMed1980

Concanavalin A inhibits the development of experimental allergic encephalomyelitis in guinea pigs.

The effect of concanavalin A (Con A) on experimental allergic encephalomyelitis (EAE) was assessed in guinea pigs with a various time, dose and route schedule. EAE was significantly suppressed when 5 mg of Con A was injected in the sensitizing injection sites within 3 days before or after sensitization with bovine spinal cord in complete Freund's adjuvant. The EAE-suppressive activity of Con A was shown by significant reductions in incidence and severity of EAE, a delayed onset of EAE and low mortality. The proliferative response of draining lymph node cells (LNC) to myelin basic protein (BP), the growth of the draining lymph nodes (LN) and the proliferation of active rosette-forming T cells in the draining LN were all significantly suppressed in Con A-treated animals than those of unsuppressed animals. The depressed LNC reactivity to BP in Con A-treated animals was not increased when nylon wool adherent cells were removed, whereas there was a significant increase in unsuppressed animals. These results suggest that Con A suppressed EAE by inhibiting the proliferation of BP-sensitized T cells in the draining LN and that the interaction between T cell subsets could exert an inhibitory effect on EAE.

Animals↗
PubMed1979

Effects of antimetabolites on the production of tubular structures in Vero cells infected with herpes simplex virus type 2.

Treatment of Vero cells infected with herpes simplex virus type 2 with the proper concentrations of hydroxyurea (HU) reduced the production of infectious virus and markedly increased the accumulation of tubular structures in the nuclei when the drug was added within 6 hours after infection. Similar accumulation of tubular structures in the infected nuclei was also observed when infected cells were treated with phosphonoacetic acid at proper concentrations. The release of HU-treated, herpes simplex virus type 2-infected cells from the drug-induced blocking of synthesis of infectious virus resulted in the marked decrease of tubular structures coincidentally with the beginning of production of infectious virus. The data suggest the possibility that the disappearance of tubular structures may be related to the active production of infectious virus.

Animals↗
PubMed1979

Correlation between the capacity of bacterial lipopolysaccharide to supress experimental allergic encephalomyelitis and its mitogenic activity for lymph node cells in guinea pigs.

Protection of guinea pigs from experimental allergic encephalomyelitis (EAE) was attempted using bacterial lipopolysaccharide (LPS) from 4 sources. The ability of these LPS to induce DNA synthesis in guinea pig lymph node (LN) cells in vitro was also investigated. It was found that there existed a good correlation between the capacity of LPS to suppress EAE and their degree of mitogenic activities for LN cells. LPS from Escherichia coli 0111:B4 (Ec-LPS), which was most effective in suppressing EAE and also best inducer of DNA synthesis in LN cells, enhanced the proliferation of cells forming antibody to myelin basic protein (BP) in the regional LN. These results, in addition to the previous report, suggested that at the inductive phase the proliferation of B lymphocytes or their products, antibodies to BP, could inhibit formation of T lymphocytes sensitized to BP, resulting in suppression of EAE. Lipid A but not PS fraction of Ec-LPS showed a protective activity against EAE and a mitogenic activity for LN cells although less so than whole LPS. In addition, Lipid A appeared to exert its mitogenic effect mainly on B rather than on T lymphocytes.

Animals↗
PubMed1979

Production of tubular structures in Vero cells infected with herpes simplex virus type 2; effects of ultraviolet light irradiation and antimetabolites.

In order to investigate the nature of tubular structures specifically found in herpes simplex virus type 2 (HSV-2)-infected cells, the multiplication of HSV-2 was studied in Vero cells cultured in the presence of varying concentrations of cytosine arabinoside (Ara-C) and cycloheximide (CH), inhibitors of DNA synthesis and protein synthesis respectively. Ara-C, at a concentration of 60 micrograms/ml, inhibited the multiplication of HSV-2 by more than 99% and also prevented the appearance of tubular structures and virus particles in the nuclei of infected cells. Nevertheless, the synthesis of virus specific surface antigens of HSV-2-infected Vero cells was not reduced, as revealed by the fluorescent antibody technique. On the other hand, 10 micrograms/ml of CH inhibited both the appearance of tubular structures and virus particles and the synthesis of virus specific surface antigens by more than 99%. These observations strongly suggest that the appearance of tubular structures is one of the late events in the process of virus multiplication. To measure the comparative genome size needed to produce membrane antigens, tubular structures and infectious centres, the effect of u.v.-inactivation of HSV-2 on these processes was studied. After u.v.-irradiation, the capacity to induce tubular structures was inactivated at a slower rate than the capacity to form infectious centres, but at a faster rate than the induction of surface antigens. Furthermore, more tubular structures could be induced by u.v.-inactivated virus than by the non-irradiated virus which was diluted to the same infectivity as the u.v.-irradiated virus. These results indicate that expression of the entire genome is not required for the production of tubular structures.

Animals↗