Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0027651 (tumor)
 685,946 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A RNA-dependent DNA polymerase (RTase) was purified from human osteosarcoma tissue by successive column chromatography of the microsomal fraction on DEAE-cellulose (DE-23 and DE-52) and phosphocellulose. The purified enzyme has a molecular weight of about 68,000, a pH optimum of 8.1, a Mg2+ optimum of 0.8 mM, Mn2+ optimum of 1.0 mM and a KCl optimum of 60 mM. The enzyme transcribes (rA)n . (dT)12, (rC)n . (dG)12-18 and (2-O-methyl C)n . (dG)18, but is unable to transcribe (dA)n . (dT)10. The enzyme has no catalytic activity in the presence of oligodeoxynucleotide initiators alone, indicating the absence of terminal deoxynucleotidyl transferase. The purified enzyme is able to transcribe the heteropolymeric regions of a 70S RNA from R(Mu)LV. The presented data support the presence of a RNA-dependent DNA polymerase in human osteosarcoma tissue with biochemical properties, resembling those of C-type RNA tumor viruses.
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PMID:Purification and biochemical characterization of a virus-specific reverse transcriptase from human osteosarcoma tissue. 9 60

Tw osteosarcomas of jaw bones have been studied by electron microscopy. The objectives were to examine the specific cell types in relation to functions and ultrastructural features, and to examine matrices produced by tumor cells. The osteosarcoma cells were subdivided into four cell types: anaplastic, chondroblastic, osteoblastic, and osteocytic--giant cells were not considered in the present investigation. Compared to normal bone cells, no specific sign of malignancy was found. However, tumor cells seem to lose functional abilities, i.e. a modification of matrix. Consequently, tumor matrix has altered organic and inorganic components with impairment of collagen maturation and matrix mineralization. The alteration in both processes may be related to a diminished production of proteoglycans. The cytogenic hypothesis of a tumor stem cell may be supported by the identification of anaplastic osteosarcoma cells resembling immature reticulum cells. One may speculate on transformation of this cell type as a genetically predetermined osteoprogenitor cell of malignant potential.
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PMID:Ultrastructural study of tumor cell differentiation in osteosarcoma of jaw bones. 9 36

A single intramedullary administration of each dose (15 approximately 20 mg) of 4-nitroquinoline 1-oxide, 3-methylcholanthrene, or 7,12-dimethylbenz[alpha]anthracene was applied to the mandible, diaphysis, or distal metaphysis of the femur of rabbits. The highest incidence in production of osteosarcoma was obtained from the group in which 4-nitroquinoline 1-oxide was applied to the distal metaphysis (75%, including one case of chondrosarcoma). Tumors hardly appeared in any of the groups when given 3-methylcholanthrene or 7,12-dimethylbenz[alpha]anthracene. Histologically, three kinds of entities were recognized from the quantitative difference of the reactive tissues which appeared around carcinogens. It is estimated that the condition of entity III induces the highest incidence of osteosarcoma if chemical carcinogens are given into the bone marrow of experimental animals.
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PMID:Difference in the induction of osteosarcoma in rabbit bone with single administration of three kinds of chemical carcinogens. 10 16

Experience with computed tomography (CT) in 25 patients with histologically proven osteosarcoma is presented. CT was as accurate as conventional radiographic methods in determining the presence of a lesion, but it was definitely superior in defining the extent of disease, particularly intramedullary extension and soft tissue extraosseous tumor component. CT was capable of demonstrating skip metastases in one patient. CT plays a key role in the preoperative evaluation of osteosarcoma patients, particularly when less than radical surgery is planned as primary treatment and when postoperative recurrence is suspected. CT is also useful in assessing the response to therapy in nonsurgical cases. The technique involved in the performance of this examination is discussed.
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PMID:Computed tomography in the evaluation of osteosarcoma: experience with 25 cases. 10 81

Development of osteogenic sarcoma after retinoblastoma radiotherapy in three patients, two of whom were siblings, is reported. Pluridirectional tomography and plain skull radiography demonstrated soft tissue masses, sinus opacification, and bone destruction and sclerosis in all three patients. Computed tomography reliably indicated the presence or absence of intracranial tumor extension in the two patients in whom it was performed. Radionuclide bone scanning was a useful adjunct for osteosarcomatous detection.
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PMID:Osteogenic sarcoma after retinoblastoma radiotherapy. 11 16

For many years, research into human cancer has concentrated on human patients and on artificially induced neoplasms in inbred murine hosts. Cancer, however, affects a great variety of mammals, particularly those that have been domesticated. Suchf naturally occurring neoplasms are common in dogs, cats, cattle, horses, etc., and offer fertile ground for studies relating to epidemiologyf, etiology, immunobiology, and therapy. Canine osteosarcoma is described in detail. The clinicopathologic features of this canine tumor closely approximate that of human osteosarcoma and thus make canine osteosarcoma an invaluable comparative model. Canine osteosarcoma and other naturally occurring tumors lie intermediate between the mouse models and human cancer. The use of these veterinary models in the future fabric of cancer research will broaden its base and will influence our conceptual approach to research and clinical options.
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PMID:The use of naturally occurring cancer in domestic animals for research into human cancer: general considerations and a review of canine skeletal osteosarcoma. 11 62

The carcinogenicity of aflatoxin B1 (AFB1) has been under evaluation in nonhuman primates for the past 13 years. A total of 47 Old World monkeys, chiefly rhesus and cynomolgus, have received AFB1 i.p. (0.125 to 0.25 mg/kg) and/or p.o. (0.1 to 0.8 mg/kg) for 2 months or longer, and 12 are currently alive and without evidence of tumor. Thirteen of the 35 monkeys necropsied to date (37%) developed one or more malignant neoplasms, yielding an overall tumor incidence of 28%. Five of the neoplasms were primary liver tumors (2 hepatocellular carcinomas and 3 hemangioendothelial sarcomas), and 2 cases of osteogenic sarcoma were found. Other tumors diagnosed were 6 carcinomas of the gall bladder or bile duct, 3 tumors of the pancreas or its ducts, and one papillary Grade I carcinoma of the urinary bladder. The tumors developed in animals receiving an average total AFB1 dose of 709 mg (range, 99 to 1354 mg) for an average of 114 months (range, 47 to 147 months). Fifteen of the 22 necropsied monkeys (68%) without tumor showed histological evidence of liver damage, including toxic hepatitis, cirrhosis, and hyperplastic liver nodules. These animals had received an average total AFB1 dose of 363 mg (range, 0.35 to 1368 mg) for an average of 55 months (range, 2 to 141 months). Our results indicate that AFB1 is a potent hepatotoxin and carcinogen in nonhuman primates and further support the hypothesis that humans exposed to this substance may be at risk of developing cancer.
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PMID:Induction of osteogenic sarcomas and tumors of the hepatobiliary system in nonhuman primates with aflatoxin B1. 11 76

Sixty-one patients with osteosarcoma were treated. Twenty-four of these patients were managed with our systematic multi-modal treatment. Overall survival rate was markedly improved chiefly by intensive systemic chemotherapy with multiple drugs, especially adriamycin and high dose methotrexate. Preoperative regional intra-arterial infusion of anti-tumor drugs and fast neutron radiotherapy were employed and it was suggested that fast neutron had a higher relative biological effectiveness and a greater therapeutic gain factor as compared with X-rays. Fast neutron radiotherapy can play a significant role in the very systematic treatment of osteosarcoma and is specifically useful for preservation of the affected limbs.
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PMID:Systematic multi-modal treatment of osteosarcoma, with special reference to the role of fast neutron radiotherapy. 11 50

The 5-year cumulative survival rate was measured in 28 cases of osteosarcoma treated with high dose radiation since 1969 is 48.8% in our clinic. It can be said that high dose radiotherapy has a significant survival effect compared to early amputation therapy for the patient with osteosarcoma. The difference of the prognosis between both therapies may be related to immunological reactions. In order to obtain further information on this possibility, experimental studies on mice suffering from tumors have been performed. Results revealed that spleen cell migration inhibition reaction, as a specific immunity, became negative and anti-tumor properties were eliminated as a results of the amputation of the limb bearing the tumor. Also, when BCG as well as irradiated tumor cells were administered to tumor-afflicted mice, an improved rate of survival among the mice was observed. As a result of the study of patients with osteosarcoma that has been treated with high dose radiation related to changes in their immunity, it was disclosed that there was a marked tendency to diminution in peripheral blood lymphocytes or T cells in cases with poorer prognoses. In cases of long survival, both showed high values. Lymphoblastgenesis by PHA and PWM showed higher values in cases with better prognoses than in those with poor prognoses. Furthermore, in many of the cases in which the tuberculin skin reaction became negative, a short survival period was noted.
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PMID:[Immunologic studies concerned with high dose radiotherapy for osteosarcoma (author's transl)]. 11 20

A case of endobronchial carcinosarcoma is reported in which a small area of epidermoid carcinoma at the base of the partly necrotic, polypoid part of the tumor was found, and where the pulmonary invasive part consisted of osteosarcoma. To our knowledge such a case has not been published before. In the literature 23 cases of endobronchial carcinosarcoma were found. All but one of those alive at the time of diagnosis were considered operable. The first year survival rate of the reviewed and the reported cases was 36% of all or 42% of the resected cases. The figures for bronchial carcinoma are 33% or 62% of the resected cases. The pre- and post-operative mortality for endobronchial carcinosarcoma was 23%. Because follow-up was too short, the 5 year survival rate cannot be estimated. Features common to pulmonary sarcoma and pseudosarcoma of the upper respiratory tract are also discussed.
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PMID:Endobronchial carcinosarcoma. A case with osteosarcoma of pulmonary invasive part, and a review with respect to prognosis. 14 May 9


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