PubMed Health⌕ Search

Biomedical subjects

T Natori

Publications and source records attributed to T Natori.

At least 19 recordsLinked to original sources
PubMed1979

[Experimental yolk sac tumors in the rat (author's transl)].

A study on the experimentally induced yolk sac tumor in the rat was made in special regard to the characteristics and origin of tumor cells. Pregnant rats which fetuses were removed on the 12th day of gestation, developed tumors derived from the fetal membranes left outside the uterus, which were composed of differentiated teratomas and yolk sac tumors. Serial observation of the oncogenesis revealed that an early lesion of the yolk sac tumor appeared in a nodule found as early as 3 weeks after the fetectomy and production of alpha-phetoprotein (AFP) was observed histochemically in the tumor cells 5 weeks after the fetectomy. A cultured cell line established after cloning from the transplantable yolk sac tumor which had been induced similarly and converted into ascitic form was also investigated. Light and electron microscopic studies on both induced tumors and the cultured cells indicated a similarity of AFP producing tumor cells with parietal yolk sac cells and of PAS-positive hyaline-like substance with the Reichert membrane. It is reasonable to conclude that the yolk sac tumor observed is regarded as a parietal yolk sac carcinoma described by Pierce. Histogenesis of the tumor is also discussed.

Animals↗
PubMed1978

Immunochemical evidence of a tumor-specific surface antigen obtained by detergent solubilization of the membranes of a chemically induced sarcoma, meth-A.

We reported previously the partial purification of detergent-solubilized specific tumor rejection antigen of a chemically induced sarcoma, Meth-A. During the course of the study, rabbit antiserum against a partially purified specific tumor rejection antigen preparation was raised and rendered specific by in vivo absorption. In this report we show that an antigenic molecule defined by in vivo-absorbed rabbit antiserum, which we tentatively refer to as tumor-specific surface antigen, was solublized by detergent Nonidet P40, and extensive attempts at purification were carried out by a sequence of procedures including gel filtration, isotachophoresis, and polyacrylamide gel electrophoresis. The most highly purified tumor-specific surface antigen retained some specific tumor rejection antigen activity, suggesting an association of the two activities. Both antigens were shown to have a molecular weight of about 60,000 and an electrophoretic mobility of alpha-globulin.

Animals↗
PubMed1978

Cellular immunity to solubilized tumor antigens of a methylcholanthrene-induced sarcoma with a migration inhibition assay.

BALB/c mice immunized with Nonidet P-40 (NP-40) crude solubilized (CS) extracts of a syngenetic methylcholanthrene-induced BALB/c sarcoma (Meth A) were challenged with viable Meth A cells to determine the ability of the solubilized preparations to induce transplantation rejection. Animals resisting such challenge were then used in agarose microdroplet macrophage migration inhibition (MMI) and tumor cell neutralization (Winn) assays to evaluate the antigenic specificity of these CS extracts. Spleen cells from those animals that rejected Meth A after immunization with the NP-40-solubilized preparations effectively neutralized the tumor-producing capacity of Meth A tumor cells as determined in Winn assays. MMI assays were quite sensitive and detected migration inhibition of peritoneal exudate (PE) cells from immunized mice with extract concentrations as low as picogram quantities. Specificity studies demonstrated that Meth A expressed no antigenic cross-reactivity with similarly prepared extracts of an unrelated SV40-induced sarcoma (mKSA), nor with a mineral oil-induced plasmacytoma (ADJ-PC5) of BALB/c mice. Inhibition of PE cell migration was mediated by culture supernatants (presumably migration inhibition factor [MIF]) generated from a mixture of immune spleen cells and mitomycin C (MMC)-treated Meth A cells as assayed in an indirect MMI test.

Animals↗
PubMed1977

Cell-mediated immunity against particulate and solubilized tumor-associated antigens of murine plasmacytomas detected by macrophage migration inhibition assays.

Cell-mediated immunity (CMI), as detected by the agarose microdroplet macrophage migration inhibition (MMI) assay, was investigated using peritoneal exudate cells (PEC) of BALB/c mice and several crude membrane (CM) and solubilized preparations of murine plasmacytomas. The MMI assay was quite sensitive and detected inhibition of macrophage migration as low as picogram quantities of CM, NP40 detergent- and papainsolubilized preparations (CS) of ADJ-PC5 and LPC-1 plasmacytomas. The data were highly reproducible from one experiment to the next with the same or different lots of the CM or solubilized extracts. Specificity studies demonstrated that ADJ-PC5 and LPC-1 plasmacytomas expressed cross-reactive tumor-associated antigens (TAA) as detected by MMI and confirmed by tumor challenge and Winn neutralization experiments. No cross-reactivity was observed with similar extracts prepared from an unrelated syngeneic simian virus 40 (SV40)-induced sarcoma. The inhibition of macrophage migration observed was mediated by culture supernatants generated from the mixture of plasmacytoma-immune spleen cells with antigens and then assayed in an indirect MMI assay on normal PEC. The agarose microdroplet MMI assay appeared to be a rapid and sensitive method to measure TAA recognition and to monitor TAA isolation and solubilization with minimum numbers of immune cells.

Animals↗
PubMed1977

Reverse transcriptase of foamy virus. Purification of the enzymes and immunological identification.

Reverse transcriptase from foamy virus, strain H4188 was estimated and purified. The enzyme has the following characteristics: 1. The reaction utilized preferentially oligo (dT) poly (rA) as a primer-template; however, the synthetic primer-template oligo (dT) poly (dA) could also be used to some extent. 2. The reaction utilized oligo (dG) poly (rC) as a primer-template with very low efficiency. 3. The crude virus preparation had a detectable endogenous reaction using the four deoxyribonucleotides for DNA polymerization. 4. The cation requirement for the enzyme reaction was much more biased for Mn++ than for Mg++ ions. 5. The molecular weight of the partially-purified enzyme was estimated to be about 80,000. Aggregates of 240,000 daltons were also seen. The activity of this enzyme was not inhibited by antisera against the reverse transcriptases of various type C RNA viruses, namely, feline endogenous leukemia virus, RD 114, Woolly simian sarcoma virus (SSV-1) and avian myeloblastosis virus (AMV). Antiserum against Rauscher leukemia virus (RLV) enzyme was marginally active against foamy virus enzyme, perhaps indicating a slight cross-reaction. The biochemical characteristics of foamy virus reverse transcriptase seemed to be very close to those of the type C RNA viruses, but the immunological reaction proved that the foamy virus reverse transcriptase was distinct from the others.

Epitopes↗
PubMed1977

Biologic and biochemical properties of detergent-solubilized tumor-specific transplantation antigen from a simian virus 40-induced neoplasm: brief communication.

The detergent Nonidet P40 was used to solubilize tumor-specific transplantation antigens (TSTA) from crude membranes obtained from dissociated cells of simian virus 40-induced sarcoma of BALB/c mice. A good recovery of specific tumor rejection activity was observed. One fraction, fraction V, was obtained following polyacrylamide-agarose filtration of the solubilized material, and this fraction contained most of the activity. An increased specific activity followed gel filtration. Preliminary data from lectin column chromatography of the active fraction V indicated a separation of TSTA activity from H-2 activity.

Animals↗
PubMed1977

Migration inhibition by an agarose microdroplet assay: monitoring of tumor-associated antigens on a simian virus 40-induced sarcoma.

Macrophage migration inhibition assays, with a direct agarose microdroplet method, were used to monitor TAA activity of preparations of SV-40-induced mKSA cells. These preparations included cell-free crude membranes, papain-solubilized and NP40 detergent-solubilized membrane extracts from mKSA tumor cells. The assay was extremely sensitive and could detect migration inhibition reactivity with all three types of antigenic preparations with concentrations as low at 250 ng protein/ml. The reactivities were quite reproducible from experiment to experiment using the same or different lots of these antigen preparations, and the reactivities were specific in that peritoneal exudate cells from BALB/c mice, immunized with antigenically unrelated but syngeneic plasmacytomas, were not inhibited by these antigens. The results demonstrated the usefulness of this assay in rapidly detecting small concentrations of partially purified TAA preparations by using small number of immune cells.

Animals↗
PubMed1977

Biological and biochemical properties of Nonidet P40-solubilized and partially purified tumor-specific antigens of the transplantation type from plasma membranes of a methylcholanthrene-induced sarcoma.

Tumor-specific transplantation antigen (TSTA) was solubilized from cell membranes of sarcoma Meth-A with non-ionic detergent Nonidet P40. Soluble TSTA was partially characterized by chromatographic separation and electrophoresis. The antigen responsible for tumor rejection activity had a molecular weight of approximately 70,000 daltons in the presence of detergent and an electrophoretic mobility of alpha-globulin. TSTA was well separated from mouse histocompatibility antigen H-2 by a sequence of procedures, including gel filtration, lectin affinity chromatography, column electrophoresis, and rechromatography on agarose, showed only three major bands on polyacrylamide gel electrophoresis. TSTA was specific for sarcoma Meth-A.

Animals↗
PubMed1976

The component fragments obtained by acid dissociation of papain-solubilized H-2 molecules.

H-2Kk and H-2Dd molecules were specificially purified from a radioiodinated H-2a preparation obtained by papain digestion of spleen cell membranes of A/J strain mice. The molecules were isolated by binding to H-2 alloantisera of the corresponding private specificity followed by precipitation with rabbit anti-mouse IgG antiserum. The specifically precipitated radioiodinated H-2Kk and H-2Dd molecules were dissociated by acid treatment into large and small components of about 37,000 and 11,000 respectively. These were separated by gel filtration at acid pH or by gel isoelectric focusing in the presence of 6 M urea. Each component separated by gel filtration of the acid-dissociated H-2 molecules showed a high degree of size homogeneity as determined by sodium dodecyl sulphate-acrylamide gel electrophoresis. Upon gel isoelectric focusing, however, the small components showed two peaks of radioactivity closely located together at pH 7-8, both of which had a restricted pH range, while the large components gave one peak of a relatively wide pH range of pH 5-6. The H-2Kk and H-2Dd molecules gave essentially the same pattern in terms of the numbers and the positions of the radioactivity bands. Under the iodination conditions used the large components of H-2Kk molecules contained more radioactivity than the small components, while the reverse was true in case of H-2Dd molecules. Such a difference was also found with H-2Kk and H-2Dd molecules isolated by use of alloantisera of the respective public specificity. The assay of binding of the isolated components with H-2 alloantisera of defined specificity revealed that the large components retain most of the allospecificities of the parental H-2 molecules. No H-2 allospecificities were found on the small components. The small components showed extensive binding with rabbit antiserum against mouse beta2-microglobulin. The same antiserum did not show any binding with the large components. On the other hand, both of the components did bind with rabbit antiserum against papain-solubilized H-2 molecules.

Animals↗
PubMed1976

A mouse plasma substance carrying beta2-microglobulin activity and lacking in H-2 alloantigenic activity.

A mouse plasma substance carrying beta-2-microglobulin activity and lacking in H-2 alloantigenic activity was separated from the blood plasma of A/J strain female mice. The plasma substance had a molecular size of about 300,000-400,000 daltons and an electrophoretic mobility of alpha-globulin. The plasma substance was split by papain digestion to a fragment of about 50,000-60,000 daltons that still carried beta2-microglobulin activity. The papain-split plasma substance was devoid of H-2 alloantigenic activities and Thy-1 and TL alloantigenic activities as well, but yet had a two-component structure that was similar to papain-solubilized H-2 molecules. It contained a 37,000-dalton component linked non-covalently to an 11,00-dalton component, i.e. mouse beta2-microglobulin. This plasma substance appears to be different from Ss protein or Slp protein, both found in mouse serum.

Animals↗