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Biomedical subjects

T O Yoshida

Publications and source records attributed to T O Yoshida.

At least 55 records · Page 3Linked to original sources
PubMed1987

[Anticancer drug sensitivity test using the short-term microplate culture and MTT dye reduction assay].

We have applied the MTT dye reduction assay to the anticancer drugs sensitivity test using short-term microplate cultures. The tumor cells were cultured with the anticancer drugs for 2 and 4 days. After culture, MTT dye was placed in each microwell and culture was carried out again for 4 more hours. The formazans generated by living cells were dissolved in acidified isopropyl alcohol and the absorbances of each well were measured at a wavelength of 540 nm. When tables of cytotoxicity indices classified into anticancer drugs, concentrations and durations of culture for each type of leukemic cell were made, it became possible to compare each drug and to select the effective ones. This assay is simple, precise, rapid, has no washing steps and is convenient for handling a large volume of material. We apply this assay in clinical practice.

Antineoplastic Agents↗
PubMed1986

[Serodiagnosis of microbiosis in mice with a quantitative assay of immunoglobulins by a microcomputer-introduced ELISA system. 1. Anti-Sendai virus antibodies in naturally infected mouse sera].

An enzyme-linked immunosorbent assay system combined with microcomputer data analysis was established as a quantitative assay method of immunoglobulins. The assay system was applied to measure IgG and IgM levels of anti-microbe antibodies in animals, especially mouse and rat. And now the measurement of IgG and IgM levels (ng/ml) of anti-Sendai virus (HVJ) antibodies in naturally infected mice is available. The assay system could improve serodiagnosis in the specificity and sensitivity and in the rapid treatment of many serum samples. The operation of this system was performed by a microcomputer, FM 8 connected Titertek Multiskan MC. The limited sensitivity of this assay for IgG and IgM was 10 ng/ml and 30 ng/ml, respectively. Ninety-one of serum samples were positive for IgG and/or IgM (45 samples for IgG and IgM, 44 samples for IgG, 2 samples for IgM) to Sendai virus in the tested 279 mouse sera, and serum titers were ranged from 1: 10 to 1: 12,800 in the IgG, and from 1: 20 to 1: 160 in the IgM. In these titers, serum IgG and IgM amounts were estimated to be 0.1 to 154 micrograms/ml and 0.5 to 4.8 micrograms/ml, respectively. Relationships of serum titers and antibody amounts were almost consisted, being judged like that approximately 10 micrograms/ml is 1: 400, 30 micrograms/ml is 1: 1,600 in IgG, and 2.4 micrograms/ml is 1: 80, 4 micrograms/ml is 1: 160 in IgM.

Animals↗
PubMed1986

[A new anticancer drug sensitivity test using the microplate culture and surviving tumor cell staining method].

We have developed a new anticancer drug sensitivity test using the short-term microplate culture and viable cell staining method, and the details of this method are reported. The tumor cells are cultured with the anticancer drugs for 2 days and 4 days. After culture, the microplate is centrifuged. The surviving tumor cells are fixed with ethanol and stained with crystal violet. After washing out the remaining crystal violet, 200 microliters of sodium lauryl sulfate is put into each microwell and the absorbance of each is measured. When we examined this method using leukemic cell lines, we found that the numbers of cells were in proportion to the absorbance, and that the surviving cells could be counted by the absorbance within the range of 0.4 to 1.7. On the assumption that the effective range is more than 60% of the cytotoxicity index (CI), tables of CI classified into drugs, concentrations and duration of culture for each leukemic cell line were made. With these tables, comparison of the anticancer drugs and subsequent selection of the effective ones became easier. This method is simple, rapid and convenient for handling a large volume of material. Its application to further clinical practice is therefore expected.

Antineoplastic Agents↗
PubMed1986

[Studies on the antitumor activity of human recombinant interferon alpha-2b in vitro].

Correlation between antiproliferative and binding activities of interferon (IFN) alpha-2b to various human cell lines was examined using human recombinant IFN alpha-2b. Burkitt's lymphoma Daudi cells and human renal cell carcinoma OS-RC-2 cells were sensitive to IFN alpha-2b, whereas two EB-virus-transformed B cell lines, FS and L-KT3, and human A375 melanoma cells showed low or no sensitivity. 125I-IFN alpha-2b binding assay revealed that the difference in IFN alpha-2b sensitivity was related to the number and the affinity of IFN alpha-2b receptors per cell. Experiments were then performed to investigate the influence of recombinant IFN alpha-2b on the cytostatic activity of monocytes against A375 cells in vitro. IFN alpha-2b enhanced the cytostatic activity of monocytes against A375 cells which showed low sensitivity to the direct growth inhibitory effect of IFN alpha-2b. Depletion of NK cells from the monocyte preparations by anti-Leu-11b monoclonal antibody and complement did not affect the monocyte activation by IFN alpha-2b, indicating that NK cells were not involved in this system.

Burkitt Lymphoma↗
PubMed1985

HLA antigens in patients with unexplained hepatitis following halothane anesthesia.

We examined HLA-A,B,C and DR locus antigens in 38 Japanese patients who had recovered from halothane hepatitis. The patients were divided into two subgroups, i.e. jaundice and non-jaundice groups, because the clinical features were quite different in each. DR2 was positive in 14 (58.3%) of 24 patients with jaundice, compared with 281 (33.6%) of the 837 Japanese healthy controls (chi-square with Yates' correction = 5.30, relative risk = 2.77, P less than 0.025). Conversely, Bw44 was increased in non-jaundice patients (50.0%), compared with 157 (12.7%) of the 1234 Japanese healthy controls (chi-square with Yates' correction = 13.75, relative risk = 6.86, P less than 0.001). The haplotype frequency (Hf) of Aw24-Bw52-DR2 was high in the patients with jaundice (Hf = 0.2362), while it was zero in the patients without jaundice (P less than 0.0042). These data suggest that the two groups of halothane hepatitis have different genetic backgrounds.

Adolescent↗
PubMed1985

Strain differences in the antitumor activity of an immunopotentiator, Nocardia rubra cell-wall skeleton, in B10 congenic and recombinant mice.

An immunogenetic evaluation of the antitumor activity of the immunopotentiator Nocardia rubra cell-wall skeleton (N. rubra-CWS) has been performed using non-virus-producing tumors induced by the Schmidt-Ruppin strain of Rous sarcoma virus (RSV) in B10 congenic and recombinant mice. Live tumor cells mixed with either N. rubra-CWS or a placebo control were inoculated intradermally into the right flank of syngeneic mice. With N. rubra-CWS, the development and growth of B10 mouse tumors, S1018(B10) and B10SA2F, in B10(H-2b) mice were completely inhibited in all test mice. B10.A(5R) mouse tumor, S322(5R), was completely suppressed in 23 of 25 B10.A(5R)(H-2i5) mice, and B10.BR mouse tumor, S623(BR), was completely suppressed in 7 of 14 B10.BR(H-2k) mice. However, B10.D2 mouse tumor, S908(D2), in B10.D2(H-2d) mice and B10.A mouse tumors, S826(BA) and B10ABr1F, in B10.A(H-2a) mice were not suppressed at all by N. rubra-CWS. N. rubra-CWS showed a remarkable antitumor effect in B10 mice, not only in mixed inoculation with the tumor cells but also with intratumoral administration. These effects were not seen in B10.A mice. Peritoneal exudate cells (PEC) from B10 and B10.A strains previously treated intraperitoneally with N. rubra-CWS and/or MMC-treated tumor cells showed cytolytic and cytostatic activities on tumor cells derived from both strains. These results did not reflect the strain difference seen in the in vivo studies. Mitogenic activity of N. rubra-CWS on spleen cells, however, was significantly different among B10 congenic mice; N. rubra-CWS induced greater blastogenesis of spleen cells from B10 mice than of those from B10.A mice, corresponding to the in vivo results showing strain difference. These results suggest that the host's immunogenetic background may play an important role in cancer therapy with immunopotentiators.

Adjuvants, Immunologic↗
PubMed1985

Characterization of stable Epstein-Barr (EB) virus transformed cell lines and mouse-human hybridomas producing a large quantity of anti-tetanus toxoid (TT) monoclonal antibody.

Antigen-specific human monoclonal antibodies (hMoAb) were investigated with particular emphasis on the stability and scale-up of production. Peripheral blood lymphocytes from a healthy donor previously vaccinated with tetanus toxoid (TT) were resensitized in vitro with the antigen in the presence of pokeweed mitogen (PWM). Three days after the stimulation, lymphocytes were infected with Epstein-Barr (EB) virus. Among EB virus transformants, several lymphoblastoid cell clones producing anti-TT hMoAb were established. One of these clones, 3G6, produced about 10 micrograms/ml of IgM (K) in the culture supernatant. Furthermore, 3G6 cells were fused with murine myeloma cells (X63-Ag8 X 653) and three heterogeneous hybridoma clones (HE719, HE810 and HE811) were obtained after careful hybrid selection in hypoxanthine-aminopterin-thymidine-ouabain containing medium and cloning by limiting dilution technique. These hybrid clones contained human HLA and mouse H-2d antigens together with mouse-human mixed karyotype. When these mouse-human hybridomas were injected i.p. into pristane-treated nude mice of BALB/c origin, ascites were found and a large amount of anti-TT hMoAb up to 0.5 mg/ml were produced there. These hybridomas have retained their anti-TT antibody-producing capabilities over 10 months. The approach described here has a potential application for the production of other antigen-specific hMoAb.

Animals↗
PubMed1984

Restriction molecules involved in the interaction of human T cell clones with antigen-presenting cells.

Two of three distinct human Ia molecules detected by murine monoclonal antibodies (MoAb) have been suggested to be involved in antigen presentation for T cell responses to purified protein derivatives (PPD) and herpes simplex virus (HSV). This observation was first suggested from studies on the inhibition of proliferative responses of whole T cell populations with MoAb against human Ia molecules. To determine whether a single T cell recognizes the antigen in the context of both Ia molecules or in the context of each one of two Ia molecules, we isolated and propagated PPD-reactive T cell clones from an HLA-DR heterozygous individual. They showed four different restriction patterns: type I and type II clones each appeared to be restricted to one of two HLA-DR antigens, type III clone gave anomalous patterns of response and seemed to be restricted to non-DR antigens, and type IV clone recognized antigen when both DR antigens were presented on the same antigen-presenting cells (APC) surface. Blocking study with monoclonal anti-Ia antibodies suggested that type I, II and IV clones are restricted to DR molecules and type III clones are restricted to 1B4 molecules distinct from DR or MB1 molecules. These data imply that human T cell clones recognizing PPD in the context of each one of two Ia molecules are clonally distributed.

Antibodies, Monoclonal↗
PubMed1984

Clonal distribution of human T cells recognizing PPD in the context of each of two distinct Ia molecules.

Participation of two of three distinct human Ia molecules, HLA-DR and the Ia molecule detected by monoclonal antibody (MoAb) 1B4 (1B4 molecules), in antigen presentation for T cell responses to purified protein derivative (PPD) and herpes simplex virus (HSV) was first suggested from studies on the inhibition of proliferative responses of whole T cell populations with MoAb against human Ia molecules. To determine whether a single T cell recognizes the antigen in the context of both Ia molecules or in the context of each one of two Ia molecules, we isolated and propagated PPD-reactive T cell clones from an HLA-DR heterozygous individual. The clones showed four different restriction patterns: type I and type II clones appeared to be restricted to one of two HLA-DR antigens, type III clones gave anomalous patterns of response and seemed to be restricted to non-DR antigens, and type IV clone recognized antigen when both DR antigens were presented on the same APC surface. Blocking study with MoAb to Ia molecules suggested that type I and type II clones are restricted to DR molecules and type III clones are restricted to 1B4 molecules distinct from DR or MB1 molecules. Furthermore, it is most likely that type IV clone was restricted to the interaction molecule associated with DR antigens. These data imply that human T cell clones recognizing PPD in the context of each one of two Ia molecules are clonally distinct.

Antibodies, Monoclonal↗
PubMed1984

The capacity of antigen-presenting cells is fully preserved in childhood cancer patients.

T cells from 19 out of 25 childhood cancer patients showed impaired proliferative responses to purified protein derivatives (PPD)-pulsed antigen-presenting cells (APC) although all of the patients had been immunized with BCG. To test whether such low responsiveness of T cells results from the dysfunction of T cells or from that of APC, the experiment was designed to assess the proliferative response of T cells from patients or their parents to PPD-pulsed APC from patients or parents. These combinations seem to be suitable to assess the activity of T cells or APC since at least partial identity of HLA-D/DR antigens is required for T cell-APC interactions. Although T cells from patients who showed low responsiveness to PPD failed to respond even to PPD-pulsed APC from parents, T cells from parents were able to respond to PPD-pulsed APC from patients as well as to autologous APC. These observations strongly suggest that the low responsiveness to PPD in childhood cancer patients results from the dysfunction of T cells, and the capacity of APC is fully preserved. In other words, it appears that the capacity of APC is not impaired by chemotherapy, neoplastic cells, or other factors. Suppressor T cells appeared not to be involved in such dysfunction of T cells.

Adolescent↗
PubMed1983

Correlation between tumor-specific surface antigens and src gene expression in Rous sarcoma virus-induced rat tumors.

Immunization with Rous sarcoma virus (RSV)-induced mouse tumors or with SR-3Y1 or NY8-3Y1 rat fibroblasts transformed by a wild type RSV or an env gene deletion mutant of RSV induced complete transplantation resistance against an RSV-induced mouse tumor (CSA1M) in syngeneic hosts. On the other hand, 10 of 19 mice immunized with ts68-3Y1 rat fibroblasts transformed by an src gene temperature-sensitive mutant of RSV (permissive temperature: 33-35 degrees C) could not reject the CSA1M. SR-3Y1, NY8-3Y1 and RSV-induced mouse tumors expressed a common tumor-specific cell-surface antigen (TSSA) detected by a syngeneic rat antiserum against NY8-3Y1. In ts68-3Y1, expression of the TSSA was temperature-sensitive, TSSA being detected only when ts68-3Y1 was cultivated at the permissive temperature. Immunoprecipitation showed that serum from a rabbit bearing an RSV-induced tumor detected a 60-kdalton protein in cell extracts from SR-3Y1 and NY8-3Y1. Antiserum to NY8-3Y1 failed to detect this protein. These results suggest that the tumor-specific surface antigen(s) on RSV-induced mammalian tumors was coded for by an RSV src gene that was not identical with the simple form of the 60-kdalton protein identified.

Animals↗
PubMed1982

The role of three distinct Ia-like antigen molecules in human T cell proliferative responses: effect of monoclonal anti-Ia-like antibodies.

Murine monoclonal antibodies (MoAb) to three distinct Ia-like molecules were studied for their inhibitory effects on antigen- and alloantigen-induced T cell proliferations. The MoAb were classified into three groups according to the molecules they recognized. Both the group I MoAb reacting with DR molecules and the group III MoAb were capable of inhibiting T cell proliferative responses to PPD- and HSV-Ag-pulsed APC, autologous B-LCL, and alloantigens. On th other hand, the group II MoAb, which reacted with a determinant on the molecule carrying MB1 determinants, was only capable of inhibiting T cell responses to alloantigens. These results suggest that the structure of the molecules correlates with the functional repertoire of the human Ia-like antigens.

Antibodies, Monoclonal↗
PubMed1982

Individually distinct tumor-specific cell surface antigen identified by monoclonal antibody on a Rous sarcoma virus-induced mouse tumor.

Hybrid cell lines were prepared by the fusion of BALB/c myeloma P3U-1 cells with the lymphocytes of BALB/c mice that were immunized with syngeneic Rous sarcoma virus (RSV)-induced tumor CSA1M cells. Three clones of the hybrid progeny (3.4B2, 3.4C6, and 3.5C11) produced cytotoxic IgM antibodies against CSA1M cells. One of the clones, 3.5C11, was chosen for analysis of the detailed specificity. Both direct cytotoxicity assays and absorption tests revealed that monoclonal antibody from 3.5C11 was positive only with CSA1M cells and that it failed to react with other tumors, including 20 RSV-induced mouse tumors, and normal cells. The 3.5C11 monoclonal antibody alone, with or without exogenous complement, was suppressive in the therapy of ip injected CSA1M tumor in syngeneic hosts, and significant prolongation in survival was seen in the treated mice. These results clearly showed presence of an individually distinct tumor-specific cell surface antigen on an RSV-induced mouse tumor.

Animals↗
PubMed1981

Both HLA-DR restricted and nonrestricted functions of adherent cells are required for induction of T lymphocyte proliferative responses.

There appeared to be two distinct functions of adherent cells in human T lymphocyte proliferative responses to purified protein derivative (PPD). The first is antigen-presenting ability which is mediated by antigen-presenting cells (APC) among adherent cells. By employing antiserum blocking pretreatment of APC, it was revealed that HLA-DR antigens are involved in this function and that identity or partial identity of HLA-DR antigens between APC and T lymphocytes is required for T lymphocyte antigen recognition. The second function is mediated by the soluble factor produced by adherent cells and is HLA-DR nonrestricted. Although it remains unclear whether APC and adherent cells producing the soluble factor belong to the same cell population, this second function might lead T lymphocytes to proliferative as long as T lymphocytes recognize antigen (PPD) via APC.

Animals↗
PubMed1981

Human antigen-presenting cells: characterization of the cells in the T-lymphocytes proliferative response.

Human antigen-presenting cells (APC) which present the antigen to T lymphocytes resulting in a T-lymphocyte proliferative response were found among peripheral mononuclear cells (MNC), by employing purified protein derivative (PPD) as soluble antigen. To assess the adherence capacity of human antigen-presenting cells, MNC were separated by plastic Petri dishes or nylon wool columns. Plastic nonadherent cells were almost equivalent to unseparated cells in antigen-presenting ability. Plastic adherent cells, however, showed better antigen-presenting ability than unseparated cells. On the other hand, cells passed over nylon wool columns showed essentially no ability to present PPD to T lymphocytes. Removal of phagocytic cells by carbonyl iron resulted in about 50-70% reduction in antigen-presenting ability. Carrageenan, which is known to be toxic to macrophages, had no effect on APC. By using both rabbit anti-human Ia-like antiserum and alloantiserum specific for HLA-DR phenotype and complement, it was shown that APC possessed Ia-like antigens, whereas they did not bear surface immunoglobulins. These results indicate that the human APC is probably a cell in the monocyte-macrophage lineage. Allogeneic MNC were used as APC in order to determine whether any genetic restriction exists between MNC as APC and responding T lymphocytes. Optimal stimulation was shown to require identity of mixed leukocyte reaction (MLR)- activating determinants between APC and T lymphocytes. It is however, obscure whether an HLA-D region restriction exists in these combinations because PPD-pulsed allogeneic MNC lost their ability to elicit even MLR. It is possible that this failure to elicit MLR was caused by T lymphocytes among the MNC used as APC.

Antigens↗
PubMed1980

Persistent infection of mouse tumor cells with mumps virus.

A mouse tumor cell line (MCT) persistently infected with mumps virus (strain Urabe) was obtained. No antibody or chemicals were required for establishment or maintenance of the infected cell line (M-MCT). No difference was observed by light microscopy between MCT and M-MCT cells, except for cytoplasmic inclusion bodies in 10--20% of the M-MCT cells. Hemadsorption of chicken erythrocytes, which did not necessarily coincide with inclusion positive cells was shown by 10--20% of the M-MCT cells. Immunofluorescence staining revealed that almost all M-MCT cells contained mumps virus antigens, which were seen mainly in the cytoplasm as fine granules, dots, or large clumps. Infectious mumps virus was consistently detected in the culture fluid and the released virus showed some temperature sensitivity when assayed at 34 degrees C and 40 degrees C. M-MCT was resistant to superinfection with homologous virus and showed some resistance to heterologous viruses. Thirty one clones of M-MCT were isolated by the soft agar method. Some, but not all, clones had viral antigen and all those with antigen released virus into the culture medium. The growth rates of MCT and M-MCT cells as monolayer cultures in vitro were similar, but the transplantability of M-MCT cells in syngeneic C57BL/6 mice was lower than that of MCT cells.

Animals↗