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Biomedical subjects

T Yumoto

Publications and source records attributed to T Yumoto.

At least 55 records · Page 3Linked to original sources
PubMed1980

Experimental approach to fibrous histiocytoma.

A transplantable tumor was produced in syngeneic mice inoculated with transformed bone marrow macrophages (28-12- and L-18 cell lines). The tumor composed of proliferative spindle cells was arranged in a storiform pattern, and was similar to that of human fibrous histiocytoma. Electron microscopically, the tumorous spindle cells had fibroblastic characteristics, while functionally, the tumor cells had histiocytic characteristics, and consisted of a transitional form between histiocytes and fibroblasts. We consider the spindle cells to be facultative fibroblasts. This finding is compatible with the hypothesis that fibrous histiocytoma is derived from histiocytes.

Animals↗
PubMed1980

Prelymphomatous and lymphomatous changes in splenomegaly of new zealand black mice.

The incidence of splenomegaly was 39.6% in the nontreated group and 41.0% in the treated group, not significantly different between both groups. Thymic lymphoma group shared 27.6%, while the nonthymic lymphoma group 67.9%, significantly different between both. Histological findings of splenomegaly of the nonlymphoma groups were divided into the following 5 types. 1) follicular form, 2) periarterial lymphatic sheath form, 3) red pulp hematopoietic form, 4) marginal zone form, and 5) red pulp reticulosis form. Histology of the spleen in the lymphoma group resembled each form of cases of splenomegaly in the nonlymphoma group. Lymphoma based upon immune abnormality and specific to this kind of mouse in nonthymic lymphoma continuously takes place from prelymphomatous changes in the nonlymphoma group. Splenic origin and role of mariginal zone of nonthymic lymphoma in murine lymphoma is discussed.

Animals↗
PubMed1980

Transplantable murine plasma cell leukemia with polyclonal gammopathy.

A transplantable plasma cell leukemia cell line, designated as S27, was established from a 12-month-old female New Zealand Black mouse (NZB); serum showed polyclonal elevation of gamma globulin with agarose-agar gel electrophoresis. Immunoelectrophoretic analysis of the serum showed precipitation lines in the IgG1, IgG2a, IgG2b and IgM regions. The amount of serum immunoglobulin increased rapidly with tumor growth. S27 cells proliferating in the spleen contained simultaneously IgG1, IgG2a, IgG2b in the cytoplasm as revealed by indirect immunofluorescence. Membrane immunofluorescence revealed IgG1 on the tumor cell surface. S27 cells were transplantable to syngeneic NZB mice with inoculation of spleen cell suspension, and showed the same histological and immunological findings as those of the original mouse. These findings imply that a single clone of plasma cells has the capacity to produce more than one class of immunoglobulin.

Animals↗
PubMed1980

Chromosome analysis of a brain malignant lymphoma cell line.

Chromosome studies of a malignant lymphoma cell line derived from the brain were made by Q- and G-banding techniques. The modal number of chromosomes was 45. Complex structural rearrangements were present, but the 14q+ marker chromosome frequently seen in malignant lymphomas was not identified in the cell line. The main karyotype in cells analyzed was 45, X, -Y, del (2) (q21q23), t (3;?) (p25;?), t (p12;?), -8, 11q+, 18q+, +mar. Absence of the 14q+ may be explained by: firstly, clones which possessed 14q+ marker chromosome in brain tumor cells may have been selected out with increasing culture time and repeated passages; or secondly, the presence of the 14q+ marker chromosome depends on the type of lymphoma.

Adult↗
PubMed1978

Naturally occurring angiosarcoma of the tibia in an NZB mouse.

An osteolytic bone tumor was found in a 12-month-old male NZB mouse. Macroscopically and histologically this tumor was angiosarcoma originating in bone with distant metastasis present in the spleen. The primary tumor was successfully transplanted in the back subcutaneous tissue of syngeneic mice, and the characteristics of the transplants, were found to be similar to those of the primary tumor. The ultrastructure of tumor is described.

Animals↗
PubMed1977

Transplantable lymphoma producing type K Bence-Jones protein in NZB mouse.

Spontaneous lymphoma occurring in the retroperitoneum in a 13-month-old New Zealand Black female mouse, as transplantable to the same strain mice, was subjected to immunological studies by serial transplantation as subcutaneous solid tumor (66A) and bloody ascites tumor (66B). The transplanted tumor-bearing mice showed M component in the plasma, urine and ascites. It was confirmed as type K Bence-Jones protein. Speculations were made on the relation between abnormal immunity in NZB mice and lymphoma.

Animals↗
PubMed1977

Primary intracranial malignant lymphomas with particular reference to their pathogenesis.

During the past 6 years we have experienced a total of 6 cases of malignant lymphomas, which originated primarily in the central nervous system. The most reliable diagnostic criteria will be a "perivascular cuffing" by silver impregnation with further spreading of tumor cells to the periphery, a "starry-sky" appearance consisting of numerous histiocytes with foamy cytoplasm intermingled with tumor cells, and cytological features of the imprint preparation. Since there is a close histologic similarity to extracerebral malignant lymphomas, we would like to propose that these tumors should be regarded as primary malignant lymphomas of the central nervous system instead of mere reticulum cell sarcoma-microglioma, and also would like to regard the brain to be not an exceptional site other than visceral lymphomas for occurrences of malignant lymphomas. For the pathogenesis of primary intracranial malignant lymphomas, the hypothesis, proposed by FEIGIN, of the possible existence of multipotential stem cells in the brain was discussed.

Adult↗
PubMed1976

Ultrastructural features of malignant fibrous histiocytoma of bone.

Five cases of malignant fibrous histiocytoma originating in the femur and tibia, sometimes with local recurrences, are reported. Histological and clinical characteristics of this lesion were similar to those in soft tissues with the same disease. The present histiocytomas were observed by electron microscopy and shown to consist of 5 types of neoplastic cells which were regarded as undifferentiated cells, histiocyte-like cells, which were predominating, fibroblast-like cells, multinucleated giant cells and xanthomatous cells. These findings led us to confirm the existence of malignant fibrous histiocytoma originating in bone as well as in soft tissues.

Adult↗
PubMed1976

Malignant fibrous histiocytoma of bone.

Existence of an entity called malignant fibrous histiocytoma of bone was emphasized, based on two of our own cases experienced recently and on previous reports related to this tumor. Histologically the tumor resembles markedly the malignant fibrous histiocytoma originating in the soft part. In addition, an attempt was made to clarify its biological behavior, histological subclassification and criteria to be malignant and differential diagnoses from several other bone diseases which sometimes mimic this malignant bone tumor.

Adult↗