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)

The S49 cell lines are a unique series of tumor sublines isolated from a single BALB/c thymoma. Several different sublines were previously isolated from non-mutagenized cells using pharmacologic agents that would select for different stages of thymic development. In this report we show that all seven of the sublines studied express TL class I Ag confirming their derivation from immature thymocytes. This uniform TL expression is in contrast to the previously characterized locus-specific shut off of Kd,Dd, and/or LdAg by various S49 sublines. Furthermore, S49 sublines were found to display disparate CD4/CD8 expression. Whereas the unselected subline is a CD4+/CD8+ double positive, each of the selected sublines is singly positive for either CD4 or CD8. All seven sublines were found to be CD3+ and express alpha beta TCR heterodimers. To establish whether the S49 sublines have a monoclonal or polyclonal origin, their TCR rearrangements were compared. Based on the detection of identical but unusual TCR gamma rearrangements and similarity of the alpha and beta rearrangements, we propose that the S49 sublines probably had a monoclonal origin. However, significant differences between the TCR alpha and beta gene rearrangement were observed, suggesting that these sublines have undergone further differentiation at TCR loci in addition to CD4/CD8 and MHC loci. Evidence is presented that much of this phenotypic diversity preceded their in vitro selection.
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PMID:T cell receptor rearrangements in various S49 lymphoma sublines. 132 77

Thymomas are cytologically benign epithelial neoplasms of the thymus gland. They compose 10% of mediastinal tumors, and are most common in the anterosuperior compartment. Seven to 36% of thymomas are malignant, as determined by tissue invasion, yet they metastasize in less than 3% of cases. Distinguishing lymphoma from lymphocyte-predominant thymoma is imprecise due to their histologic similarities. We present a 45-year-old man with intracranial metastatic thymoma. The lesion was interpreted radiographically as meningioma, and as possible lymphoma by frozen section. Flow cytometry proved this neoplasma to be a metastatic thymoma. Sixteen monoclonal antibodies were used to immunophenotype the CD45+ component of this tumor. Coexpression of CD4 and CD8 along with CD1 demonstrated lymphocytes of late cortical thymocyte origin; a second component was cytokeratin positive. This is the first reported case of extrathoracic metastases of thymoma diagnosed using flow cytometry. We propose this method as an invaluable technique to diagnose these histologically difficult neoplasms.
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PMID:Diagnosis of metastatic thymoma using flow cytometry. 137 81

The coincidence of autoantibodies against the acetylcholine receptor (AChR) and muscle striational antigens (SA) is a characteristic finding in thymoma-associated myasthenia gravis (MG), but their origins are still unresolved. Some common muscle antigens that were shown to be targets of anti-SA autoantibodies in thymoma-associated MG have also been detected in normal or neoplastic thymic epithelial cells, suggesting that the release of (eventually altered) antigens from the thymic tumors could elicit SA autoimmunity. In contrast to this model, we report here that titin, which is a recently reported target of SA autoimmunity, is not expressed in thymomas. In addition, we show that skeletal muscle type-II fibers exhibit a striational immunoreactivity with monoclonal antibody mAb155, which was previously identified to label a very immunogenic cytoplasmic epitope of the AChR and neoplastic epithelial cells of MG-associated thymomas. We conclude from these findings that titin autoimmunity in thymoma-associated MG is either due to a molecular mimicry mechanism involving tumor antigens (other than titin) or is a secondary phenomenon following release of titin from muscle. Based on the common immunoreactivity of the AChR, a striational antigen and thymoma, we suggest as the pathogenetic mechanism of thymoma-associated MGa "circulus vitiosus" in which SA autoimmunity could help maintain the AChR autoimmunity that is primarily elicited by the thymomas.
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PMID:A striational muscle antigen and myasthenia gravis-associated thymomas share an acetylcholine-receptor epitope. 137 3

EG7-OVA cells are mouse thymoma EL4 cells stably transfected with the complementary DNA of chicken ovalbumin (OVA) and thus express OVA epitopes as a unique antigen. Cytotoxic T lymphocytes specific to OVA can be elicited by immunization of mice with OVA osmotically loaded into syngeneic splenocytes or entrapped in liposomes. Cytotoxic T lymphocytes thus induced can specifically cytolyse the EG7-OVA cells in vitro in an antigen-specific and major histocompatibility complex-restricted manner. In the present study, we have examined in this model system whether immunization with liposomal OVA can protect mice against tumors induced by EG7-OVA cells. Vaccination with OVA either entrapped in liposomes or osmotically loaded in the syngeneic splenocytes prolonged the survival of mice which had been challenged with EG7-OVA cells, but not those mice challenged with the parent EL4 cells. The antitumor effect was attributed to the induced OVA-specific cytotoxic T lymphocyte activity, since other forms of acquired immunity such as interaction of tumor cells with specific antibody could not be detected. Our results demonstrate that immunization with antigen incorporated in liposomes could be a useful means of inducing a protective antitumor response.
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PMID:Prolonged survival of thymoma-bearing mice after vaccination with a soluble protein antigen entrapped in liposomes: a model study. 138 58

Thymoma is associated with a wide variety of syndromes. However, an association with peroxidase-negative acute myeloid leukemia and pinealoma, although feasible due to the marked influence of this tumor on the lymphoid system, has not been described previously. A patient with thymic carcinoma and pinealoma who developed peroxidase-negative acute myeloid leukemia as a late event is presented in this report.
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PMID:Thymic carcinoma associated with pinealoma and terminating with peroxidase-negative acute myeloid leukemia. 139 88

Thymic carcinomas arising within a thymoma have been reported, but the relationship between thymoma and thymic carcinoma is poorly understood. Epithelial membrane antigen (EMA) is known to be an effective marker for establishing the epithelial nature of neoplastic cells, and it is reported that staining of tumors is clearly related to the degree of tumor differentiation. Eighty-one thymomas (59 noninvasive, 22 invasive) and 14 thymic carcinomas were studied immunohistologically using antiepithelial membrane antigen (anti-EMA) monoclonal antibody. Thymic carcinomas tended to express much larger quantities of EMA than thymomas, and instances of EMA-positive thymoma were seen significantly more often in invasive thymomas than in noninvasive ones (P < 0.05). However, EMA positivity was also associated with gland-like structures, which were not necessarily associated with malignant disease. Nevertheless, in view of the concept that thymoma and thymic carcinoma show a similar cellular differentiation, EMA-positive epithelial cells in thymoma with no relation to gland-like configurations might represent a pool of cells having a latent potential for malignant disease and might be transformed into thymic carcinoma cells under certain conditions. Immunolabeling for EMA appears to be a useful tool for determining the degree of malignant disease among thymic epithelial neoplasms.
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PMID:The distribution of epithelial membrane antigen in thymic epithelial neoplasms. 139 38

Radiation osteomyelitis of the sternum is rare and usually difficult to cure. A 75-year-old man, who had undergone an exploratory sternotomy for a mediastinal tumor, not resected after all, 9 years earlier and received radiation therapy successively for the histological diagnosis of malignant thymoma, was admitted to our hospital with the chief complaint of fever and pus discharge of the anterior chest wall. He also suffered from diabetes mellitus. The skin around the fistula was dark-red and atrophic due to irradiation dermatitis and the manubrium was fissured in the midline. Open drainage and two-stage operation of direct closure was tried in vain. This case was treated successfully by resection of necrosed portion of sternum and pectoral muscle flap closure.
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PMID:[A case report of radiation osteomyelitis 9 years after irradiation for thymoma]. 140 66

The first patient was a 37-year-old man with an invasive and lymphoid cell dominant thymoma (stage III). He underwent extended total thymectomy and partial resection of the upper lobe of the left lung. Four years after the operation, he had ptosis and diplopia and was diagnosed as having myasthenia gravis (positive Tensilon test and raised antiacetylcholine receptor antibody titer). His symptoms improved with the steroid therapy. The second patient was a 37-year-old woman with an invasive and mixed type thymoma (stage III). Extended total thymectomy with combined resection of the mediastinal pleura and right phrenic nerve was performed, but the tumor recurred in the right thorax 2 years postoperatively. Subtotal resection of the parietal pleura and recurrent tumors was performed by right thoracotomy, and steroid therapy was given. She developed malaise, ptosis and diplopia three months later, and was diagnosed as having myasthenia gravis. Her symptoms disappeared after the steroid therapy was stopped. A review of the Japanese literature is presented and problems regarding the pathogenesis of this disease are discussed.
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PMID:[Two cases of post-thymectomy myasthenia gravis]. 140

Twenty-six patients with thymoma, who had magnetic resonance (MR) imaging and computed tomography (CT) before surgery, were studied. Twenty-six thymomas were classified into 11 non-invasive thymomas (Masaoka's clinical stage I) and 15 invasive thymomas (stage II, III, and IV). On MR imaging compared with histological findings, low signal intensity rim of the tumor was corresponded to fibrous capsule of the tumor, and linear and/or reticular low signal intensity lines in the tumor were corresponded to the fibrous septae dividing thymoma into lobules. The detectability of these findings by MR imaging was superior to that by CT. Margin of the tumor was smooth in non-invasive thymoma rather than invasive thymoma. The diagnostic accuracy of invasion to vessel, and pleura or lung on MR imaging and CT was compared with operative and histological findings. MR imaging was same as CT in its ability to detect tumoral invasion to vessel, and slightly superior to pleura or lung. In conclusion MR images clearly show the findings corresponding to pathologic specimens, and MR imaging combining with CT is useful to differentiate non-invasive thymoma to invasive thymoma.
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PMID:[MR imaging of thymoma--comparison with CT, operative, and pathological findings]. 140 84

EL-4 ascites thymoma cells are shown to have high aerobic glycolysis and decreased Pasteur effect. At the same time, glucose produces a much smaller inhibitory effect on cell respiration (Crabtree effect) than in Ehrlich ascites carcinoma (EAC) cells. In intact EL-4 cells, the respiratory control ratio (RCR) was found to be 6.2 with endogenous substrates and 8.0 with glutamine. Glucose decreased the RCR to 3.2, by stimulating the state 4 respiration. In rat thymocytes and EAC cells, such an effect of glucose was absent (RCR of 7.0 and 7.2, respectively). It is suggested that in EL-4 tumor cells, the high aerobic glycolysis and small Crabtree effect may be due to glucose-induced 'uncoupling' of oxidation and phosphorylation.
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PMID:Glucose decreases respiratory control ratio in EL-4 tumor cells. 142 78


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