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Biomedical subjects

T Inada

Publications and source records attributed to T Inada.

At least 235 records · Page 13Linked to original sources
PubMed1985

Pattern of infection and selective loss of Ia positive cells in suckling and adult mice inoculated with lactic dehydrogenase virus.

Lactic dehydrogenase virus (LDV) infected cells were localised in cryostat sections of infected adult and suckling mice by fluorescent antibody staining. In almost every organ except brain and spinal cord, LDV infected cells were present in interstitial connective tissue, including dermis and submucosa of gastrointestinal and urinogenital tracts. They were also present in liver sinusoids and red pulp of spleen. The tissue distribution, shape, and fluorescence staining pattern of infected cells were similar in adult and suckling mice. The reactivity with monoclonal antibody to mouse macrophages (F4/80) and to Ia antigens indicated that infected cells were Ia antigen positive macrophages, and this was confirmed in double labelling experiments. Peak numbers of LDV infected cells were seen in every organ 12-18 hours post infection (p.i.), disappearing rapidly thereafter until at 48 hours p.i. they could no longer be detected. At the same time Ia positive cells fell to undetectable levels, although macrophages were still present in reduced numbers. At 7 days p.i. the total number of macrophages in sections had returned to normal, but the number of Ia positive cells remained at low levels. Macrophages recovered from peritoneal cavity and spleen of intraperitoneally infected mice were also studied. Ia positive cells had virtually disappeared from peritoneal cavity at 24-48 hours, and from spleen at 24-72 hours. Three weeks after infection the proportion of Ia positive cells was still low when compared with that of normal mice suggesting selective loss of these cells.

Animals↗
PubMed1985

Enhancing antibodies, macrophages and virulence in mouse cytomegalovirus infection.

The infectivity of tissue culture-passed mouse cytomegalovirus (MCMV) for resident mouse peritoneal macrophages in the presence of serial dilutions of antiviral antibody was studied by fluorescent antibody staining and virus yields. Although MCMV was neutralized by high concentrations of antiserum, there was a twofold enhancement of infectivity by subneutralizing antibody concentrations. On further dilution of antiserum, significant neutralization appeared again. When F(ab')2 fragments of anti-MCMV IgG were used or when macrophages were pretreated with monoclonal antibody to Fc receptor, there was no enhancement, and no neutralization at high dilutions of antiserum. This suggests that both enhancement and high dilution neutralization are mediated via the Fc portion of IgG and Fc receptors of macrophages. Tissue culture-passed virus whose infectivity for macrophages was reduced by high dilutions of antibody was converted to a more infectious state by addition of anti-mouse immunoglobulin. Similar results were obtained with salivary gland virus, which is less infectious for macrophages and is coated with non-neutralizing antibody. Tissue culture-passed virus is known to be less virulent for suckling mice and more infectious for macrophages than salivary gland-passed virus. When tissue culture-passed virus was coated with appropriately diluted antiviral antibody, not only was its infectivity for macrophages reduced, but it also became more virulent than control virus treated with normal mouse serum. These results are interpreted in terms of the optimal density of Fc on the virus-immunoglobulin complex in relation to the density of Fc receptors on macrophages.

Animals↗
PubMed1985

Association of virulence of murine cytomegalovirus with macrophage susceptibility and with virion-bound non-neutralizing antibody.

A comparison was made of the virulence in vivo and the infectivity in vitro for macrophages of (i) tissue culture-passed mouse cytomegalovirus (MCMV), (ii) salivary gland virus taken 3 weeks after infection (SGV 3w), and (iii) salivary gland virus taken 1 week after infection (SGV 1w). Salivary gland virus (3w) is known to be coated with non-neutralizing antibody, and is more virulent for newborn suckling mice and less infectious for macrophages than tissue culture-passed virus (TCV). Properties of SGV 1w were similar to those of TCV. Infectivity of SGV 3w for macrophages was significantly enhanced by treatment with trypsin (10 micrograms/ml) and at the same time virulence was lost. When SGV 1w or TCV were treated with trypsin the infectivity for macrophages was unaltered as long as the inoculum was adjusted to contain the same number of p.f.u. as assayed in MEF. Trypsin-treated SGV 3w was neutralized not by rabbit anti-mouse IgG Fc, but by anti-Fab, whereas untreated virus was neutralized by both of these anti-mouse immunoglobulins. These results are discussed in terms of the association of virulence with virion-bound antibody and Fc receptors on macrophages.

Animals↗
PubMed1985

Ia antigens and Fc receptors of mouse peritoneal macrophages as determinants of susceptibility to lactic dehydrogenase virus.

The relationship between susceptibility of mouse peritoneal macrophages to lactic dehydrogenase-elevating virus (LDV) infection and expression of I region-coded antigens (Ia) on these cells was investigated. The proportion of Ia-positive cells in resident peritoneal macrophages from adult and suckling mice were 4 to 10% and 50 to 70% respectively. Approximately the same percentage of the cells were susceptible to LDV, as detected by fluorescent antibody staining. In adult mice, double-labelling experiments showed that most of the Ia-positive cells were LDV-infected. When the cells were cultured for more than 24 h in vitro, Ia-positive cells rapidly disappeared and the culture became resistant to LDV. Removal of Ia-positive cells by treatment with anti-Ia plus complement or enrichment using an anti-Ia-coated Petri dish simultaneously removed or enriched for LDV-susceptible cells. Treatment of cells with trypsin (1 mg/ml) removed their I-A and I-E antigens and simultaneously abolished susceptibility for LDV. When LDV was preincubated with subneutralizing amounts of antibody, infectivity for macrophages was enhanced and the proportion of LDV-infected cells was higher than that of Ia-positive cells. This suggests that Fc receptors on macrophages can act as receptors for LDV coated with antiviral IgG.

Animals↗
PubMed1985

[Cell kinetics of human lung small cell carcinomas transplanted into nude mice].

Three human lung small cell carcinoma (SCC) xenografts serially transplanted into BALB/c nude mice were used for cell kinetic analysis. SCC strains, Lu-24, Lu-130 and Lu-134, were inoculated into the backs of nude mice, and when each tumor reached more than 300 mg, 50 microCi of 3H-thymidine per mouse was administered ip. The percentage labeled mitosis curve was obtained from the autoradiographic specimens which were labeled by the pulse-chase method. Cell cycle phase, growth fraction (GF) and cell loss factor (CL) were assessed by the methods of Quastler, Fujita and Steel, respectively. These cell kinetic parameters were compared with those of six control human gastrocolic and breast carcinoma xenografts which were previously reported by us. It was noticed that the cell cycle times (Tc) of SCC were statistically shorter than those of controls and this short Tc was found to be dependent on their short post-mitotic resting phases. GFs and labeling indices of SCC were observed to be statistically lower than those of controls, suggesting an incomplete adaptation of SCC xenografts to the host nude mice. Whereas some modifications by the host mice on the cell kinetics were supposed, the characteristics of SCC cell kinetics were thought to be essentially preserved in nude mice and these kinetic parameters were observed to be stable throughout the serial transfers. Accordingly, the SCC xenograft-nude mouse system was considered to be useful as an experimental therapeutic model of human lung small cell carcinomas.

Animals↗
PubMed1985

Proton therapy in Japan.

There are two facilities for clinical trials with protons in Japan: the National Institute of Radiological Sciences (NIRS), Chiba, and the Particle Radiation Medical Science Center (PARMS), University of Tsukuba. At the National Institute of Radiological Sciences, patient treatment with the 70 MeV proton beam began in November 1979, and 29 patients were treated through December 1984. Of 11 patients who received protons only, 9 have had local control of the tumor. Two of the 9 patients, suffering from recurrent tumor after radical photon beam irradiation, developed complications after proton treatment. In the patients treated with photons or neutrons followed by proton boost, tumors were controlled in 12 of 18 patients (66.6%), and no complications were observed in this series. Malignant melanoma could not be controlled with the proton beam. A spot-beam-scanning system for protons has been effectively used in the clinical trials to minimize the dose to the normal tissues and to concentrate the dose in the target volume. At the Particle Radiation Medical Science Center, University of Tsukuba, treatment with a vertical 250 MeV proton beam was begun in April 1983, and 22 patients were treated through February 1984. Local control of the tumor was observed in 14 of 22 patients (63.6%), whereas there was no local control in the treatment of glioblastoma multiforme. There have been no severe complications in patients treated at PARMS. The results suggest that local control of tumors will be better with proton beams than with photon beams, whereas additional modalities are required to manage radioresistant tumors.

Adult↗
PubMed1984

Quantitative measurements of an intrastrain cross-reactive idiotype in IgE antibodies.

This paper describes the development of methods for quantitation of an intrastrain cross-reactive idiotype (CRIA) in IgE antibodies directed to the p-azophenylarsonate (Ar) group and their application to normally immunized and idiotypically suppressed mice. The data were validated by the use of monoclonal and serum anti-Ar antibodies known to possess or lack CRIA. The idiotype was absent in the IgE as well as the total anti-Ar population of idiotypically suppressed mice. A good correlation was noted between the CRIA content of total and IgE anti-Ar with a trend toward a somewhat lower content in the IgE population. Irradiated mice that received immune cells prior to further immunization expressed relatively low concentrations of the idiotype (per weight unit of anti-Ar). The method will be useful in studies of the regulation of the switch to IgE synthesis.

Animals↗
PubMed1984

[Growth of human tumor transplanted into nude mice with various genetic backgrounds].

Nude mice with different genetic backgrounds were used for the experiment to evaluate the growth of human and murine tumors in the different hosts. Twelve human tumors including 5 gastric carcinomas (St-4, St-10, St-15, St-40, KS-1), 2 colon carcinomas (Co-3, Exp-42), 1 breast carcinoma (MX-1), 1 bile duct carcinoma (Ch-1), 1 hepatocellular hepatoma (Li-4) and 2 hemangiosarcomas (LC-27-R, LC-27-UR), and one murine tumor spontaneously arisen from C3H/HeN nu/+ mouse were transplanted into the subcutaneous tissue of nude mice with genetic backgrounds of BALB/cA, DDD and ICR (CD-1). BALB/cA-nu was originated from the Central Institute for Experimental Animals, DDD-nu was supplied from the Institute of Medical Science, University of Tokyo and ICR (CD-1)-nu was supplied from Charles River Co., Ltd. Tumors were measured by the width (W) and length (L) three times a week by the same person. The tumor volume (V) was estimated by the formula V = W2 X L/2. Tumor doubling time (Td) during the exponential growth phase was compared between the nude mice with different genetic backgrounds. It was found that Td of MX-1 in DDD-nu mice and Td of St-40 and Exp-42 in BALB/cA-nu mice were shortened in comparison with those of tumors transplanted into nude mice with the other strains. However, no statistically significant differences were observed when t-test of matched pairs and coefficients of correlation were applied to compare Td in the other kinds of nude mice. Nude mice with genetic backgrounds of DDD and ICR (CD-1) were thought to be also useful for various kinds of therapeutic experiments in human tumor xenografts/nude mice system.

Adenocarcinoma↗
PubMed1983

Three dimensional spot beam scanning method for proton conformation radiation therapy.

In order to fully utilize the excellent dose distribution of heavy charged particles for radiation therapy a 3-D spot beam scanning method for proton conformation therapy has been developed. It is effective in reducing the dose to normal tissues compared with the ordinary beam scattering method or the 2-D spot beam scanning method. Hopefully, it will also be useful for heavy charged particle therapy in the future.

Humans↗