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Biomedical subjects

Y Ubayama

Publications and source records attributed to Y Ubayama.

26 records · Page 2Linked to original sources
PubMed1984

[Chemotherapy of advanced bone and soft tissue sarcoma].

The primary site of metastasis of bone and soft tissue sarcoma is the lung. Control of these sarcomas depends upon the prevention and treatment of their pulmonary metastasis. The introduction of a chemotherapy consisting mainly of Adriamycin and high-dose methotrexate dramatically improved the prognosis of osteosarcoma. However the effectiveness of chemotherapy has not yet been duplicated in soft tissue sarcomas except some childhood sarcomas. We analyzed the clinical data for pulmonary metastasis of osteosarcomas and soft tissue sarcomas. Based on these analyses, we tried to clarify the nature of pulmonary metastasis of these sarcomas and to evaluate its response to treatment, that this would yield clues to future treatment of these sarcomas.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1984

[A histological study on osteosarcoma. Part I: Relationship between modes of osteoid formation and differentiation of tumor cells].

This study was undertaken to clarify whether the osteoid forming activity seen in osteosarcoma can be used as an index to show the degree of differentiation of the tumor. Twenty six human osteosarcomas which had been amputated in our clinics were used in this study. The whole slice of the primary tumor was stained by HE and Masson stain. The following observations were microscopically made in the peripheral, transitional and central part of the tumor; 1) the content and maturity of osteoid, 2) the degree of polymorphism and mitotic activity of the tumor cells. In 13 out of 26 cases, the amount and maturity of osteoid gradually increased toward the center of the tumor. On the other hand, the degree of polymorphism and mitotic activity of tumor cells in these cases gradually decreased toward the center. Mitotic activity in the center of the tumor decreased to about half of the peripheral part. The clinical courses of these 13 cases were milder than those in which the gradual increase of the amount and maturity of osteoid toward the center of the tumor were not observed. These results showed that zone formation of osteoid maturity in osteosarcoma can be used as an index to show the degree of differentiation of the tumor.

Adolescent↗
PubMed1983

Characteristics of human soft tissue sarcomas in xenografts and in vitro.

Two permanent, transplantable strains of rhabdomyosarcoma (SAS) and synovial sarcoma (KUSHI) were established by transplanting them serially into nude mice. The original SAS tumor and its transplant were histologically identical and gave an appearance of so-called embryonal rhabdomyosarcoma. The KUSHI tumor changed after the second passage, showing the biphasic pattern of synovial sarcoma, while undifferentiated myoblast-like cells were observed throughout the original tumor. Three in vitro cell lines from the SAS and one from the KUSHI tumor were successfully established. The human origin of the SAS and KUSHI transplanted tumors could be verified by the presence of human chromosomes. The cells cultured from the SAS tumor were more sensitive to anticancer drugs than those of the KUSHI tumor. However, as the number of serial passages on nude mice increased, the sensitivities of the SAS cells decreased, while those of the KUSHI cells increased. The modal chromosome number of the SAS tumor changed from 51 to 49 to 46 during serial passages on nude mice. These observations suggest that the sensitivities to anticancer drugs not only differ among soft tissue sarcomas of different histologic types, but also change continuously during the growth of the tumor itself.

Animals↗
PubMed1982

Analysis of osteoid-forming activity of human osteosarcoma implanted into nude mice.

Thirty cases of human osteosarcoma were transplanted subcutaneously in BALB/c nude mice. Twenty-four tumours survived in animals and showed the histopathology of the original tumours. Growth of transplantable tumours was closely related to the amount of osteoid tissue and tumours with predominant osteoid tissue showed slow growth. Tumours whose osteoid-forming activity tended to diminish or disappear were likely to fail early during serial transplantation. Two osteosarcoma (SU and ISHI) were established into permanent transplantable strains and were maintained in nude mice for more than three years. These two strains showed striking differences in their growth capacity; SU grew rapidly and frequently formed pulmonary tumours after tail vein injection of tumour cells. Histologically, ISHI osteosarcoma cells continue to form osteoid tissue, whereas SU cells showed anaplastic changes and lost osteoid-forming activity. Alkaline phosphatase and Lactate Dehydrogenase (LDH) activities of tumour tissue were lower in ISHI than SU, and significant elevation of the relative value of Fraction III of LDH isozyme has been demonstrated in SU, and Fraction IV in ISHI. On this basis, the authors discuss the relation between the amount of osteoid formation or LDH isozyme patterns and the malignant potential of human osteosarcoma.

Alkaline Phosphatase↗
PubMed1982

[A study on the treatment of pulmonary metastatic osteosarcoma].

The primary site of metastasis of osteosarcoma is the lung. Even if a primary lesion was completely removed by radical surgery, more than 90% of the patients died of pulmonary metastasis in one to two years in the past. A control of osteosarcoma depends upon the prevention and treatment of its pulmonary metastasis. An introduction of chemotherapy consisting mainly of adriamycin and high-dose methotrexate dramatically improved the prognosis of osteosarcoma. We analyzed the clinical data, and gross as well as histopathologic post mortem findings, in 161 cases without chemotherapy and 42 cases with systemic adjuvant chemotherapy. Based on these analysis, we tried to clarify the nature of pulmonary metastasis of osteosarcoma and to evaluate its response to treatment from a standpoint of clinical pathology, hoping that this would yield a clue to future treatment of osteosarcoma.

Antineoplastic Agents↗
PubMed1980

A light and electron microscopic study with comments on their relation to malignant fibrous histiocytoma and angiosarcoma.

Analysis of 365 cases of malignant soft tissue tumors revealed 83 cases of liposarcoma. The ages of the patients were distributed between 18 and 86 years with a mean average of 54.3 years. Approximately 50% of the cases were located in the lower extremity. Histologically, they consisted of 5 types; well differentiated (17 cases), myxoid (49 cases), round cell (3 cases), pleomorphic (11 cases), and mixed (3 cases). The appearance of lipoblasts of either the signet-ring type or mulberry (multivacuolated) type with displaced nuclei was the common characteristic feature for all types. Electron microscopically, lipid droplets were found inside of endoplasmic reticulum in lipoblasts, and abundant glycogen granules were seen in the cells containing only few lipid droplets. The lipoblasts were usually located close to the vascular wall in the interstitium, and findings suggesting an intimate relation between pericytes and lipoblasts were encountered. Although the differential diagnosis of malignant fibrous histiocytoma and liposarcoma was made possible by the appearance of lipoblasts in the latter, storiform pattern and histiocyte-like cells sometimes appeared in poorly differentiated liposarcoma. This tendency was also found in angiosarcoma. A close follow-up of recurrent cases revealed that there are actually cases of liposarcoma with malignant fibrous histiocytoma-like pattern and angiosarcoma with malignant fibrous histiocytoma-like pattern. It was considered that malignant fibrous histiocytoma-like figures can appear in various poorly differentiated sarcomas.

Adult↗
PubMedDate not supplied

An in vitro method for testing the sensitivities to drugs of human osteosarcomas grafted onto nude mice.

Sensitivities to anticancer drugs were tested with cultured cells from six osteosarcomas transplanted onto nude mice and those of six human osteosarcomas cultured in vitro directly from the original tumor. The suppression by the anticancer drugs of 3H-TdR incorporation into the cultured cells was examined. The cells that had been grafted onto nude mice were highly sensitive to ADM and MMC and less sensitive to BLM and MTX in all of the tumors tested. Similar results were obtained with cells cultured directly in vitro from the original tumor. These results were somewhat comparable with those achieved by measuring cell survival and the success of back transplants onto nude mice after treatment with drugs. If further information on appropriate labeled precursors can be developed, testing the sensitivity of tumors to drugs by measuring the suppression of nucleic acid synthesis should prove useful in clinical applications.

Animals↗