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Query: UMLS:C0027651 (tumor)
 685,946 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

RNA was extracted from the Burkitt lymphoma-derived cell line Raji and from Burkitt lymphoma tumor biopsies, isotope labeled in vitro by iodination with 125I, and hybridized to electrophoretically separated restriction endonuclease fragments of Epstein-Barr virus DNA on nitrocellulose membranes. The results indicated that only certain parts of the Epstein-Barr virus genome are represented as polyribosomal RNA in Raji cells, with a pronounced dominance of RNA sequences complementary to a 2.0 x 10(6)-dalton segment of Epstein-Barr virus DNA located close to the left end of the viral genome. A map of virus-specific polyribosomal RNA sequences was constructed, which indicated that a minimum of three regions of the Epstein-Barr virus genome are expressed in Raji cells. Total-cell RNA preparations from five Burkitt lymphoma biopsies contained RNA sequences homologous to the same regions of Epstein-Barr virus DNA as polyribosomal RNA from Raji cells, albeit at different relative proportions.
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PMID:Identification of transcribed regions of Epstein-Barr virus DNA in Burkitt lymphoma-derived cells. 23 90

Spontaneous sister chromatid exchanges and banded karyotypes were studied in blood lymphocytes from 96 individuals: seven patients with chronic myelogenous leukemia, 15 normal controls, and five "cancer families" comprising 12 cancer patients, 40 tumor-free blood relatives and 22 spouses. The families had: malignant melanoma; Epstein-Barr virus-associated malignancies and a birth defect syndrome; non-Hodgkin lymphoma and diverse carcinomas; Hodgkin's lymphoma and adenocarcinomas; and acute myelogenous leukemia. In addition to the Philadelphia chromosome in chronic myelogenous leukemia patients, karyotypic abnormalities, especially breaks and fragments, were found in 29% of cancer family members, but were inconsistent and usually attributable to radiotherapy. Mean sister chromatid exchange values were normal in chronic myelogenous leukemia, but low (by t-test) in tumor patients and their blood relatives in cancer-prone families. In tumor patients, mean sister chromatid exchange levels fell as age increased. After adjusting for this age effect, no significant differences remained among groups. In patients at high risk of cancer (because they have chronic myelogenous leukemia or a strong family history of cancer), spontaneous sister chromatid exchange rates were not a marker of cancer risk.
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PMID:Sister chromatid exchanges and chromosomes in chronic myelogenous leukemia and cancer families. 28 71

Thirteen cases of nasopharyngeal carcinoma (NPC) and 16 cases of non-NPC tumors in the nasopharynx or in adjacent locations were investigated clinically, immunologically, and pathologically. All tumors were classified according to the TNM classification, and the stage and course of the disease was correlated with the histological tumor type, the T- and B-cell distribution in tumor tissue and in the peripheral blood, as well as with antibody titers against Epstein-Barr virus (EBV). The results showed a positive correlation of decreased T- and B-cells in tumor tissue and of decreased T-cells in the peripheral blood with the extend of the tumor in both NPC and non-NPC cases, with some exceptions of lymphocyte rich neoplasms (lymphoepithelial carcinoma and malignant lymphoma). Antibodies against EBV (early antigen and capsid antigen) became progressively elevated with increasing tumor stage in NPC-cases but not in non-NPC cases. The latter, however, was observed only in two histological types of NPC's: anaplastic carcinoma and lymphoepithelial carcinoma; titers in the remaining tumor types stayed insignificant.
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PMID:Nasopharyngeal and adjacent neoplasms: a clinico-pathologic and immunologic study. 30 42

In five cases of endemic ethmoidal carcinoma in cattle from the Dominican Republic three tumor types could be classified: undifferentiated carcinoma (3), adenocarcinoma (1), and squamous cell carcinoma (1). Electron microscopy showed that the tumor cells in undifferentiated carcinomas closely resembled the cells of the normal olfactory mucosa. This was especially true for the dark cells of Bowman's gland. Ultrastructurally, the lymphoid cells of the undifferentiated bovine carcinoma resembled the lymphoid cells of human nasopharyngeal carcinoma being closely associated with Epstein-Barr Virus. This and epidemiological observations suggested a viral cause of endemic ethmoidal carcinoma.
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PMID:Histological and electron microscopic studies of endemic ethmoidal carcinomas in cattle. 44 48

We have described a 51-year-old patient with unresectable mesenteric giant lymph node hyperplasia of the plasma cell type, severe systemic manifestations, and profound anemia. Supression of erythropoiesis may have been related to the presence of a circulating erythropoietic inhibitor produced by the lymphoid tumor. Markedly elevated titers to Epstein-Barr virus capsid antigen suggest that this virus may be important in the etiology of the abnormal lymphoid proliferation. The marked clinical response and decrease in the size of the tumor following irradiation suggests that radiation therapy may be an alternative form of treatment for similar patients with unresectable lesions.
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PMID:Remission of giant lymph node hyperplasia with anemia after radiotherapy. 47 62

A viral inhibitor(s) is released in the supernate of mixed cultures containing human or mouse lymphocytes and cells from certain lines. The inhibitor is active against a variety of unrelated viruses and is a protein that is not toxic for cells. It does not inactivate viruses directly, but inhibits viral replication through an intracellular mechanism that involves synthesis by the cells of both RNA and protein. These characteristics identify the inhibitor as an interferon. The anti-viral activity is contained in at least two molecular species, of approximately 25,000 and 45,000 daltons, respectively. In addition to the anti-viral activity, the supernates of the mixed cultures display an anti-cellular activity, the inhibition of DNA synthesis and of cell multiplication. The anti-viral and the anti-cellular activities are positively correlated in supernates from various cultures and in partially purified preparations. The human cell population responsible for interferon production is composed mainly of Fc-receptor positive, surface immunoglobulin negative, non-T-cell lymphocytes. The ability of certain cell lines to induce interferon seems to be preferentially associated with tumor origin or with in vitro transformation by certain viruses (Epstein-Barr virus, murine sarcoma virus).
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PMID:Anti-viral activity induced by culturing lymphocytes with tumor-derived or virus-transformed cells. Identification of the anti-viral activity as interferon and characterization of the human effector lymphocyte subpopulation. 65 Jan 55

Two established North American Burkitt lymphoma cell lines were studied by chromosomal banding techniques. The SU-AmB-1 line previously shown to be negative for the Epstein-Barr virus (EBV) was found to have, among other changes, a translocation from the long arm (q) of chromosome 8 onto 14q. The SU-AmB-2 line, which contains the EBV genome, also displayed the same 8/14 translocation. These results were compared with data from three EBV-positive tumor cell lines derived from patients with African Burkitt's lymphoma. Our findings indicate that a translocation from 8q onto 14q occurs in both African and North American Burkitt lymphomas, and that this abnormality apparently is not related directly to EBV. This chromosome translocation therefore may be an important event in the development of human lymphocytic malignancy, analogous to the occurrence of the Philadelphia chromosome rearrangement in chronic myelogenous leukemia.
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PMID:Chromosome 14 translocation in African and North American Burkitt's lymphoma;. 84 16

Delayed cutaneous hypersensitivity reactions to standard recall antigens (candidin, mumps and PPD), to crude membrane extracts of a cell line derived from Burkitt's lymphoma (Raji) and to cell line derived from normal lymphocytes (F265) were sequentially evaluated in 44 patients with Burkitt's lymphoma. Sixteen patients (36%) manifested delayed hypersensitivity responses to the standard antigens and seven (16%) to the Raji membrane extract at presentation. Following successful chemotherapy, there was prompt and significant improvement of reactivity to both the standard and Raji antigens (p greater than 0.001), suggesting that the initial impairment of delayed hypersensitivity was most likely related to tumor burden. By 9 months after treatment, all patients in sustained remission expressed reactivity to Raji and 21 of 22 to the standard antigens. None of the patients skin-tested with the F265 extract at presentation gave a positive response and only one subsequently expressed reactivity after remission was induced. On relapse, reactivity to the standard antigens was more readily lost (4 of 11) then reactivity to the Raji extract (1 of 7). Pretreatment delayed hypersensitivity to the standard antigens also correlated better with long-term survival than to pretreatment responses to Raji. It remains to be determined whether the antigens expressed in the Raji extract are indeed tumor-specific or related to Epstein-Barr virus.
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PMID:Sequential evaluation of cutaneous delayed hypersensitivity responses to recall and to lymphoid cell line antigens in Burkitt's lymphoma. 90 83

The general cell-mediated immunological reactivity of patients with acute leukemia has been found to be intact, although it may be depressed by extensive disease or by chemotherapy. Patients with acute leukemia also have cellular immune reactivity against tumor associated antigens, as measured by skin tests for delayed hypersensitivity, lymphocyte stimulation, and 51Cr release cytotoxicity. Skin reactions to autologous and allogeneic crude membrane extracts of blast cells correlated with disease state, positive in many patients in remission and negative in most patients in relapse. Extracts of human lymphoid tissue culture cell lines derived from lymphomas or leukemia also gave positive reactions in patients with acute leukemia, and also in patients with lymphoma and nasopharyngeal carcinoma. The antigens detected in the skin tests with the lymphoid cell lines appear to be different from those associated with Epstein-Barr virus (EBV) and from those detected in the 51Cr release assay. Evidence is presented which suggests a complex variety of antigens on blast cells and on the cell lines. Although leukemia associated antigens were also detected by lymphocyte stimulation and by cytotoxicity assays, the results did not correlate with the skin tests nor with each other. The possible use of these assays for monitoring the chemotherapy and immunotherapy of acute leukemia patients is discussed.
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PMID:Cell-mediated immunity in human acute leukemia. 116 4

While rare in most parts of the world, cancer of the nasopharynx is shown to be very common in Southern Chinese whether living in South China or elsewhere, is of intermediate level in a variety of Mongoloid populations such as Malays, Thais, Javanese and Vietnamese and the indigeneous peoples of Borneo, yet uncommon in North China and very rare in Japan. Moderate frequencies are seen in parts of the Maghreb, Malta, the Sudan and possibly East Africa. Occupational risk has not been demonstrated and case-control studies have generally been negative. Studies of migrants, notably Chinese of the US, have shown a diminution of mortality for the second and third generation, yet their risk still remains much higher than for white Americans. There is no convincing evidence of elevated risk among low-risk Caucasian populations living in South East Asia. The above findings, which have been held to indicate a genetic predisposition to an unknown environmental agent, are reviewed in the light of the recent discoveries of a characteristic HL-A profile in the high risk Cantonese. Several investigations of the HL-A profiles of groups of contrasting incidence are suggested as these may be of significance in relation to the postulated causal role of the Epstein-Barr virus for this neoplasm.
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PMID:[Epidemiology of cancer of the cavum]. 119 85


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