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Biomedical subjects

T Masuda

Publications and source records attributed to T Masuda.

At least 631 records · Page 35Linked to original sources
PubMed1986

Induction of antitumor resistance to mouse leukemia L1210 by spergualins.

Spergualin and its analog, 15-deoxyspergualin showed a marked antitumor effect against L1210 by intraperitoneal and oral administrations. After treatment with these substances 40- or 60-day survivors (cured mice of L1210) were resistant to reinoculation of L1210 cells. They were resistant only to L1210. The antitumor effector cells in these mice were determined to be T cells. NK activity of spleen cells was also enhanced by spergualins. The antitumor activity of 15-deoxyspergualin was markedly reduced in immuno-deficient mice. IL (interleukin)-2 production, but not IL-1, was enhanced in supernatant of mixed lymphocyte cultures by treatment with 15-deoxyspergualin. The mechanism of action of 15-deoxyspergualin on the immune system was discussed.

Animals↗
PubMed1986

Isolation and properties of valanimycin, a new azoxy antibiotic.

Valanimycin, a new azoxy antibiotic, was isolated from culture broths of a streptomycete. Valanimycin is an unstable oil at room temperature and active against some Gram-positive and Gram-negative bacteria, mouse leukemia L1210 cells in cultures, and prolongs the life span of mice inoculated with Ehrlich carcinoma or L1210.

Animals↗
PubMed1986

[Dietary factors to induce and suppress colon cancer development].

It has been clear that the promoting stimulus from bile acids and other colonic constituents play an important role in colon cancer induction in man and in animal models, although essential for the initiation of this cancer probably is relatively week. The level and concentration of bile acids in the colon largely depend on the amount of dietary fat and fiber. High fat diet increases fecal bile acids, and fiber increases the fecal volume and may have a protecting effect through dilution of the bile acids in presenting to the colonic mucosa. It is suggested in animal models that changes of the enterohepatic circulation of bile acids following surgery such as cholecystectomy and right-sided hemicolectomy could provide another cocarcinogenic stimulus or anticarcinogenic mechanism in the development of this cancer.

Animals↗
PubMed1986

[Anti-cancer treatment with prostaglandin synthetase inhibitor in animal models].

Carcinomas produce elevated quantities of prostaglandins (PGs), particularly the E series, which can play an important role in the suppression of the cellular immune reaction in tumor-bearing individuals. These findings have raised the possibility that PG synthetase inhibitor can restore the immune activity against tumors. The anti-tumor activity of indomethacin, a potent PG synthetase inhibitor, was investigated in mice implanted with colon carcinoma 38, colon carcinoma 26 and Lewis lung carcinoma in a series of model studies for cancer treatment in man. Treatment with indomethacin substantially reduced the levels of PGs, particularly PGE2 in tumor tissue, inhibited the tumor growth, particularly the early stage of cell proliferation, prolonged the survival time, eliminated tumors in the abdominal cavity, and inhibited metastatic tumor recurrence after surgery. Also, the treatment reduced the growth of human gastric and colon carcinomas transplanted into nude mice. Thus, indomethacin might also be effective against human carcinomas. It is postulated that PG synthetase inhibitor may prove to be a good therapeutic tool effective against human cancer when used in combination with chemotherapeutic and other immunotherapeutic drugs as well as with low-dose radiation therapy.

Animals↗
PubMed1986

Coexistence of hydroa vacciniforme and malignant lymphoma.

Ten years after the onset of hydroa vacciniforme (HV), a 16-year-old boy developed edema and red induration of the face, ears, and dorsa of the hands. Aggravation of cutaneous manifestations was associated with general malaise, headache, fever, lymphadenopathy, hepatosplenomegaly, and an increase of several serum enzymes. The vesicle was situated intraepidermally with thrombosis and hemorrhage underneath. This confirmed the diagnosis of HV. In addition, dense cell infiltrate was seen in deep dermis and subcutaneous tissue. Histologic and immunohistochemical studies of the dermal cell infiltrate and lymph node showed an infiltrate of helper T lymphocytes with an atypia and histiocytic cells (S100[-], alpha-subunit[+]). Hence, we concluded HV and malignant lymphoma coexisted in this patient.

Adolescent↗
PubMed1986

Recognition of serum alkaline phosphatase by murine monoclonal antibodies against human osteosarcoma cells.

Using OST6 and OST7 monoclonal antibodies against human osteosarcoma cells, a solid-phase radioimmunosandwich assay was developed to quantitate a human osterosarcoma-associated antigen in a total of 242 sera from healthy adults and patients with various diseases. The levels of the antigen in sera were high in patients with osteosarcoma and in children without tumorous diseases compared with healthy adults; however, the highest level of the antigen was found in patients with obstructive jaundice. The quantity of the antigen correlated with serum alkaline phosphatase (EC 3.1.3.1.) activity, and showed a strong correlation (correlation coefficient, 0.94) in 50 sera. Immunolocalization of enzyme activity assay using monoclonal antibodies was performed to ascertain whether the antigen had alkaline phosphatase activity. This assay proved that OST6, OST7, and OST15 monoclonal antibodies recognized serum alkaline phosphatase; furthermore, these monoclonal antibodies seemed to react with not only the bone isoenzyme but also the liver isoenzyme.

Alkaline Phosphatase↗
PubMed1986

Steroid-induced osteonecrosis of the femoral condyle--a clinical study of eighteen knees in ten patients.

Clinical feature of rarely occurring steroid-induced osteonecrosis of the femoral condyle was analyzed in 10 patients. Patients' ages at onset ranged from 19 years to 43 years. The patients consisted of 2 cases affected unilaterally and 8 cases affected bilaterally. In two knees lesion developed in the medial condyle, but it involved the lateral condyle of 11 knees or both the medial and lateral condyles of 5 knees. Mean period from the start of steroid therapy to manifestation of lesion was 79 months and mean total dose was 29.0 g. Subjectively, knee pain was not so severe and ADL was not so limited in most cases. Radiographically, lesions which were located solely in anterior area or posterior condyle belonged to the initial or moderate stage. However, the majority of those lesions which were located mainly in the central area was medium or large in size belonged to the advanced stages.

Adult↗
PubMed1986

Clinical significance of statistical discrimination employing serum TA-4, TPA, and CEA levels in uterine cervical cancer.

The serum levels of TA-4, TPA, and CEA were measured simultaneously in 52 patients with uterine cervical cancer and 99 healthy females. The findings were examined statistically by discriminant analysis method. The diagnostic usefulness of discriminant analysis employing the serum values for these three tumor markers was studied for uterine cervical cancer and compared with the diagnostic efficacy using each tumor marker alone. The following results were obtained: In the uterine cervical cancer patients, the frequencies of cases with the elevated serum levels were 55.8% for TA-4, 46.2% for TPA, and 36.5% for CEA. The functional formula, Z = 1.8395 log TA-4 + 3.5314 log TPA + 1.0130 log CEA-7.7352, was obtained by the stepwise discriminant analysis method. With the values obtained from this formula, 71.2% of patients with uterine cervical cancer were correctly classified in the uterine cervical cancer group. In the uterine cervical cancer patients, the values obtained from this formula increased according to the progression of the clinical stage and reflected the disappearance or persistence of tumor lesions after several therapies. From the above results, it was concluded that the discriminant analysis employing the serum values for three tumor markers was extremely useful in determining complete remission of uterine cervical cancers after several therapies, as well as for early diagnosis of the recurrences in uterine cervical cancer which were not detected by the cytologic smear examinations, compared with the measurement for each tumor marker alone. This discriminant analysis, however, was less effective for early diagnosis of uterine cervical cancer than the cervical cytologic smear test.

Analysis of Variance↗
PubMed1986

Scanning electron microscopic features of spleen in the rat and human: a comparative study.

The marginal zone, white pulp and red pulp of rat and human spleen were studied by scanning electron microscopy and were compared. The marginal zone was observed in both species. The arterial termination in the marginal zone was quite different between both species. The follicular arteries terminated at the boundary of the white pulp and formed a vascular net regarded as the marginal sinus in rat. On the other hand, numerous arterial termini of the follicular and sheathed arteries were scatteringly found in the marginal zone in man. The central artery was surrounded with flat reticular cells in rat and human spleen. In the red pulp of rat, the arterial termini were funnel-shaped or tubular. The sheath of the sheathed arteries of man revealed a circumferential lamellar structure consisting of flat reticular cells, and most free cells of the sheath were washed away by perfusion.

Aging↗
PubMed1985

Synergistic interaction of a cytokine produced by embryonic fibroblasts and a lymphokine contained in Con A-stimulated spleen cell culture for murine macrophage differentiation: a model experiment using cell line cells, M1.

The modulating activity of the culture supernatant of Con A-stimulated murine spleen cells for macrophages was investigated by using M-1 cells, which could differentiate into macrophage-like cells (referred to as M+1 hereafter), cocultured in a conditioned medium (CM) containing a differentiation factor (DF) obtained from the secondary culture of murine embryonic fibroblasts. DF induced Ia antigens on M-1 cells at a high rate in parallel with the appearance of Fc-receptor (FcR)-dependent phagocytic activity for erythrocytes coated with an antibody (EA). In contrast, Con A-sup alone had no modulating effect on M-1 cells. However, the Con A-sup stimulates synergistically M-1 cells with DF. Thus, coculture of M-1 cells with Con A-sup and DF generates M++1 cells which possess higher phagocytic activity than M+1 cells. These cells also exhibited stronger accessory cell activity than M+1 cells when tested for their promoting effect on IL-2 production by Sephadex G-10-passed spleen cells. The accessory cell activity of M++1 cells was further enhanced by culture with lymphocytes in the presence of indomethacin while that of M+1 cells did not change. These findings suggest that M-1 cells probably acquire potentiating, as well as inhibitory activity at the same time when cultured with DF and Con A-sup. The functional maturation caused by Con A-sup seemed to be associated with the expression of a receptor for a lymphokine, termed phagocytosis-augmenting factor (PAF) which is present in the Con A-sup. Such a receptor appeared to be common to macrophage lineage, since PAF in Con A-sup was absorbed out with splenic adherent cells and peritoneal exudate cells (PEC) in addition to M+1 cells, but not with nonadherent splenic lymphocytes or lymphoid cell line cells, such as EL-4 and L-1210. This fact suggests that PAF is different from interferon-gamma (IFN) which is known to modulate the function of lymphocytes. Inability of PAF to bind Cibacron Blue-Sepharose, unlike IFN, supports this notion. The molecular weight of PAF is approximately 2-3 X 10(4). Thus, the present studies suggest the requirement of at least two signals for the full maturation of macrophages, a cytokine represented by DF and a lymphokine, by PAF.

Animals↗
PubMed1985

Organ-specific autoimmune diseases induced in mice by elimination of T cell subset. I. Evidence for the active participation of T cells in natural self-tolerance; deficit of a T cell subset as a possible cause of autoimmune disease.

Organ-specific autoimmune diseases such as oophoritis, gastritis, thyroiditis, and orchitis were induced in female or male nude (nu/nu) mice by the transfer of nu/+spleen cells from which particular Lyt T cell subset(s) had been removed: nu/+spleen cells treated with anti-Lyt-1 plus complement (C) caused disease in recipient nude mice; anti-Lyt-2 plus C-treated spleen cells, in contrast, did not. The cells responsible for disease induction are believed to be Thy-1+, Lyt-1-, 2,3- (Thy-1, Lyt-1, 2,3), since spleen cells treated with mixed antisera, including anti-Lyt-1 and anti-Lyt-2, plus C, could induce the disease with almost the same incidence as anti-Lyt-1 plus C-treated cells (oophoritis 50%, gastritis 25%, thyroiditis 10-20%, and orchitis 40%). Cells treated with mixed antisera of anti-Thy-1, anti-Lyt-1, and anti-Lyt-2, plus C, could not induce autoimmune disease. Each induced autoimmune disease could be adoptively transferred to other nude mice via spleen cells, with resulting histological lesion of corresponding organs and development of specific circulating autoantibodies. Since anti-Thy-1 plus C treatment of donor spleen cells abrogated the capacity to transfer the disease, we conclude that T cells are required as effector cells, and that these may develop from Lyt-1-, 2,3- cells. Lyt-1+, 2,3- cells were demonstrated to have suppressive activity upon the development of the diseases; induction of autoimmunity was completely inhibited by the cotransfer of Lyt-1+, 2,3- cells with Lyt-1-, 2,3- cells. When anti-Lyt-2 plus C-treated cells (i.e., Lyt-1+, 2,3- and Lyt-1-, 2,3- cells) were mixed with anti-Lyt-1 and anti-Lyt-2 plus C-treated cells (i.e., Lyt-1-, 2,3- cells) in various ratios, then transferred to nude mice, the development of each autoimmune disease was clearly inhibited, even by small doses of Lyt-1+, 2,3- cells. The autoimmune disease we were able to induce was quite similar to human organ-specific autoimmune disease in terms of the spectrum of organs involved, histopathological features, and the development of autoantibodies to corresponding organ components (oocytes, parietal cells, thyroid colloid, including thyroglobulin, and sperm).(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1985

A lectinlike receptor on murine macrophage cell line cells, Mm1: involvement of sialic acid-binding sites in opsonin-independent phagocytosis for xenogeneic red cells.

The recognition mechanism of xenogenic red cells by mouse macrophages was studied by using established cell lines. Approximately 30% of cell line cells Mm1 which lack la antigen, as well as of thioglycollate-induced peritoneal macrophages from SL/Am mice (TGC-M phi) could ingest unopsonized quail red cells (QRC). In contrast, an undifferentiated type of cell line, M1-, and another type of macrophage cell line, Mk1-C, possessing accessory cell activity in association with the expression of la antigen, had no phagocytic activity for QRC. Approximately 80% of Mm1 cells, as well as TGC-M phi formed rosettes with QRC, whereas M1- and Mk1-C cells did not; indicating that specific binding sites for QRC are expressed on a large portion of Mm1 and TGC-M phi but not on M1- and Mk1-C cells. No requirement of divalent cation (Mg++, Ca++) and metabolic energy was observed for rosette formation between Mm1 cells and QRC. Protease treatment of Mm1 cells eliminated the rosetting activity, whereas periodate oxidation of glycosidase treatment slightly enhanced this activity, suggesting the involvement of surface protein in binding sites of Mm1 cells. In contrast to these findings on Mm1 cells, binding components of QRC were sensitive to periodate oxidation or neuraminidase treatment but resistant to protease, suggesting that the terminal sialic acid residues of carbohydrate of QRC are recognized by Mm1 cells. Furthermore, N-acetylneuraminic acid (NeuNAc) inhibited the rosette formation and promoted the dissociation of rosettes already formed. N-Acetylneuramin lactose (Neu-NAc-Lact) was more efficient in rosette inhibition than NeuNAc. These sugars also blocked the phagocytosis of QRC by Mm1 cells but had no effect on either Fc-mediated phagocytosis or latex ingestion. These results suggest that phagocytosis of QRC by murine macrophages is mediated by protease-sensitive binding sites recognizing terminal sialic acid residues of QRC in conjunction with additional carbohydrates.

Animals↗