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)

Cysteine had been reported to increase survival time in thymoma-bearing mice and the interpretation suggested was that this was due to inhibition of a collagenase activity associated with some tumor cells by a chelating action of cysteine. In the present work it was shown that cysteine was a particularly potent inhibitor of amino acid transport into S37 ascites tumor cells, raising another possible interpretation of the earlier data. Sarcomas have previously been reported to lack collagenase activity; a survival study using S37 cells was therefore undertaken in an attempt to distinguish between possible interpretations of the earlier data involving thymomas. A null result was obtained with either cysteine or EDTA, reinforcing the earlier interpretation that survival enhancement with thymoma-bearing mice was due to an effect on collagenase. Other sulfhydryl analogs were found to inhibit transport also, and the effect was more pronounced with system L than system A. The reason for cysteine's particularly potent action on amino acid transport may be associated either with chelation of a metal ion involved in transport, or the involvement of the gamma-glutamyl cycle in the support of amino acid transport.
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PMID:Effects of cysteine upon tumor cells. 2 29

The expression of endogenous ecotropic viruses in radiation-induced thymomas of C57BL/6 mice was examined. Competition radioimmunoassays for AKR MuLV gp71, p30, and p12 were used for viral antigen expression. 3 of 40 lymphomas had readily detectable ecotropic gp71 at levels of 95-689 ng/mg protein; the remainder of the tumors had no detectable gp71 (less than 1.0 ng/mg protein). 30 thymomas were characterized by the presence of MuLV p30 at levels of 1-10 ng/mg protein, levels that were comparable to those found in thymus extracts from age-matched, nonirradiated control. 10 tumors were characterized by having p30 levels of 10-30 ng/mg protein. In one tumor significant levels of AKR MuLV p12 were detectable. Since B-tropic and N-tropic viruses from C57BL/6 mice have glycoproteins (gp71) indistinguishable from AKR MuLV gp71 and the N-tropic virus had a p12 serologically identical to AKR MuLV p12, these results demonstrate that overt endogenous B-tropic virus was detectable in 2 of 40 thymomas and endogenous N-tropic virus was detectable in 1 of 40 thymomas. The lack of overt expression of gp71 or p12 was also confirmed by cytotoxicity assays using monospecific antisera to these viral proteins. Radiation-induced lymphomas were also examined for the presence of reverse transcriptase after chromatography of tissue extracts on poly G-Sepharose. One tumor, which was characterized by the lack of gp71, also had no detectable reverse transcriptase; whereas one tumor with gp71 was characterized by readily detectable levels of reverse transcriptase in cellular extracts. The presence of viral RNA was examined using AKR cDNA. Low levels of RNA capable of hybridizing with AKR cDNA were found in age-matched, nonirradiated mice; these hybrids had Tm's of 72 degrees C, while hybrids with AKR MuLV 70S RNA had Tm's of 80 degrees C. In 1 of 12 thymomas the concentration of hybridizable RNA and the Tm of the hybrids were identical to control values. In 9 of 12 thymomas the concentration of hybridizable sequences increased approximately three-to fivefold and the Tm of these hybrids varied from 73 to 75 degrees C. In 1 of 12 thymomas the concentration of hybridizable sequences increased over 100-fold, hybridized completely with AKR MuLV cDNA, and the hybrids had Tm's of 79 degrees C. This thymoma was also characterized by the presence of the AKR MuLV type of gp71 and p12. One tumor was characterized by a 10-to 100-fold increase in hybridizable sequences, which only partially hybridized with AKR MuLV cDNA, and hybrids had a Tm of 73 degrees C. This tumor was characterized by the presence of AKR MuLV gp71 but not AKR MuLV p12. The results taken together demonstrate that overt endogenous ecotropic virus expression is only rarely detectable in radiation-induced thymomas of C57BL/6 mice.
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PMID:Radiation leukemia in C57BL/6 mice. II. Lack of ecotropic virus expression in the majority of lymphomas. 6 29

Young female AKR mice made leukemic by iv inoculation of 10(3) spontaneous AKR thymoma cells were treated with repeated injections of irradiated cells from the same tumor. Treatment began 1 day after injection of the viable cells. The cytotoxicity of sera and lymphoid cells from healthy mice immunized with lymphoma cells from either treated or nontreated mice with leukemia grafts revealed that the tumor cells could be subdivided into four distinct antigenic types. One type (clone A) accounted for about 97% of the lymphoma cells in each mouse with spontaneous leukemia, whereas the remaining 3% were subdivided into three other distinct antigenic types (clones B, C, and D). Lymphoma cells from treated mice with grafted leukemia were never clone A type but either clone B, C, or D type. Repeated sc injections of 10(7) irradiated cells from spontaneous AKR thymomas induced from 15 to 34% cure in mice with grafts of leukemia cells. Treatment with only clone A induced about 32% cure, whereas treatment with clone B, C, or D had no beneficial effect. Treatment with 10(7) cells each of clone A plus clone B gave 33% cure; clone A plus clone B plus clone C, 45%; and all four clones cured 92% of the mice with leukemia grafts. The efficiency of immunotherapy may be influenced by the natural clonality of the tumor to be treated.
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PMID:Natural polyclonality of spontaneous AKR leukemia and its consequences for so-called specific immunotherapy. 8 93

A case is presented of a 60-year-old woman with fatigue, dyspnea, and chest pain. A chest x-ray film revealed an abnormal cardiac silhouette. Echocardiography revealed a large, echo-free area with well-demarcated, discrete borders adjacent to the right heart border. This structure decreased in size with inspiration and did not show pulsatile cardiac motion. Cardiac catheterization confirmed the extracardiac nature of the lesion and also showed a "constrictive" pattern with equalization of diastolic pressures. Surgical exploration revealed a large cystic thymoma. With removal of the tumor, intracardiac pressures returned to normal.
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PMID:Cystic thymoma simulating contrictive pericarditis. The role of echocardiography in the differential diagnosis. 12 66

Fifty-seven thymomas, defined as neoplasms of the epithelial-reticular framework cells of the thymus, were assessed in respect to histologic type, inclusive of there ultrastructural aspects. The median age of the 57 patients was 40.4 years, with a range of 2 1/2--72 years. All neoplasms were located in the anterior mediastinum. The tumours in 40 cases were encapsulated and without invasion of adjacent tissue or implants (equal to non-invasive thymomas). The tumors in 17 cases were invasive of adjacent tissue, particularly mediastinal pleura, pericard and trachea. Six of 57 patients (equal to 10.5%) with thymomas have had a thoracic and supraclavicular lymph node metastasis, and osteolytic metastases in the vertebrae and sternum. Thirty-seven (equal to 64.9%) were so-called lympho-epithelial, 7 (equal to 12.3%) pure epithelial, 4 (equal to 7.0%) atypical (or anaplastic) with granulomatous focuses, 3 (equal to 5.3%) carcinoid and one (equal to 1.8%) seminomatous tumors. One patient have had a thymic cyst as a tumor-like conditions of the thymus, and four patients (equal to 7.0%) have had a thymo-lipoma. The histologic type of thymoma had no proof value in predicting prognosis with the exception of the so-called atypical or anaplastic thymoma. The fine structural aspects of thymomas and the fine structural differential diagnosis of anterior mediastinal tumors are discussed.
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PMID:[A comparative clinical and pathological study on the classification and prognostic features of 57 thymomas. I. Microscopy and ultrastructural pathology (author's transl)]. 14 45

Mice have been immunosuppressed with cyclophosphamide, cortisone-acetate, irradiation, or Ehrlich ascitic fluid (EAF) and then grafted with Ehrlich tumor or with one of the following strain-specific tumors: thymoma, methylcholanthrene-induced fibrosarcoma, B-16 melanoma, lymphatic leukaemia, and myeloid leukaemia. Immunosuppression of the host influenced very differently the growth of transplanted malignancies. The growth of thymoma and of Ehrlich tumor was regularly enhanced. The growth of fibrosarcoma and of melanoma, on the other hand, was retarded in mice pretreated with EAF and X-rays, or remained unchanged in mice pretreated with drugs. Leukaemia growth was not influenced by any immunosuppressive treatment; the only exception was enhanced growth of lymphoid leukaemia in animals pretreated with EAF. Thus different tumors grew differently in animals immunosuppressed by the same immunosuppressive agent, while different immunosuppressive treatment changed the growth of one particular tumor always in the same way. From this we concluded: (1) there is no rule as to how immunosuppression of the host will influence tumor growth; and (2) the way in which the malignant growth will be changed depends mainly upon the type of the tumor and probably not very much upon the type of immunosuppressive treatment.
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PMID:Effect of immunosuppression on the growth of six murine tumors. 15 96

Radiologic findings in the thymoma-hypogammaglobulinemia syndrome are encountered in three stages reflecting the natural history of the syndrome. Initially, a mediastinal mass is apparent on chest x-ray in an asymptomataic patient. At this stage a failing immune system has apparently induced compensatory thymic hyperplasia which progresses to frank neoplasia. In 55% of the cases this thymic tumor is paracardiac in location. With progressive failure of immunoglobulin production, acute and chronic pulmonary infiltrates occur secondary to infection. Markedly, decreased IgA in the bowel may eventually be manifested by radiologic changes of exudative enteropathy.
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PMID:Radiologic changes in the thymoma-hypogammaglobulinemia syndrome. 17 84

A 69-year-old man with a mediastinal mass was found to have atypical lymphoid cells in peripheral blood and bone marrow. Light and electron microscopic studies showed that the mediastinal mass was a thymoma. B- and T-cell differentiation and PHA responsiveness in the tumor and peripheral blood were consistent with T-cells. After excision of the tumor and a course of radiotherapy the B/T ratio and PHA responsiveness in peripheral blood returned to normal while the atypical lymphocytes disappeared from circulation.
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PMID:Thymoma immunological and ultrastructural characterization. 30 Jun 47

6 years after resection and postirradiation of an "asymptomatic" thymoma, myasthenia gravis developed in a 46 year old man which improved within 6 months following initiation of immunosuppressive therapy with azathioprine. In a 28 year old man with incomplete operative removal of a metastasizing malignant thymoma, a myasthenia gravis appeared 8 weeks after surgery, i.e. before irradiation of the tumor relics. Myasthenia improved upon irradiation of the tumor relics and was no longer demonstrable one year after onset of its clinical signs. During the whole period of manifestation of the myasthenia, antibodies to skeletal muscle were deomonstrated in the first case, while, in the second case, in which antinuclear factors were present in the serum throughout the course of the myasthenia, muscular antibodies were detected only prefinally, i.e. in a stage without clinical symptoms of myasthenia. A review of the literature indicates that myasthenia gravis is a particularly frequent event in postthymectomy-syndromes (e.g. polymyositis, thyreoiditis, lupus erythematosus, hematological and dermatological syndromes). In postthymectomy-myasthenia, latency of manifestation, clinical distribution and its course may be rather variable. The problems of diagnosis, immunology and therapy of postthymectomy-myasthenia are discussed and general conclusions concerning postthymectomy-syndromes are drawn.
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PMID:[Problems of postthymectomy-syndromes, e.g. myasthenia gravis (author's transl)]. 30 37

Cell-to-cell interaction was investigated in various malignant tumor cells (human ovarial tumor, lung cancer, carcinoma of larynx and hamster melanoma cell) and in human lymphoblastoid cells (T-cell (MOLT-4 cell), thymoma cells and B-cells (Burkitt lymphoma cell)). Live lymphoblastoid cells did not adhere to the cell surfaces of tumor cells nor the lymphoblastoid cells were ingested by tumor cells without immunologic and specific treatment. Tumor cells as well as T-cells and B-cells had receptors to concanavalin A on their surfaces, and they showed marked cell binding of tumor cells and lymphoblastoid cells. Moreover, tumor cells that phagocytized lymphoblasts underwent marked cell destruction within 4 hours of cell binding. The cytolytic mechanism of the target tumor cell was probably related to contact with the lymphoblastoid cells and was increased by ingestive activity, and metabolic disturbance by lymphotoxin in tumor cells.
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PMID:Tumor cell phagocytosis and cytotoxicity of lymphoblastoid cells following concanavalin A treatment. 30 16


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