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

Tumor cell lines have been established in continuous culture from two North American Burkitt's lymphomas. The SU-AmB-1 line, derived from a patient with low serum antibody titers to Epstein-Barr virus (EBV), was devoid of EBV genomes by the reaction for EBV-associated nuclear antigen (EBNA), could not be induced to express EBV antigens, and was highly refractory to EBV superinfection. Conversely, the SU-AmB-2 cell line, derived from a patient with "African type" serology, yielded a positive EBNA reaction and was readily inducible and superinfectable. Although both cell lines possessed B (bone-marrow-derived) cell characteristics, they had different surface marker patterns. It is postulated that two different classes of undifferentiated B cell lymphomas exist, one of which is positive for the presence of EBV genomes and occurs endemically in Africa and New Guinea and sporadically in other parts of the world, the other of which is EBV-negative and occurs sporadically throughout the world, including the endemic areas.
 ...
PMID:Surface marker characteristics and Epstein-Barr virus studies of two established North American Burkitt's lymphoma cell lines. 17 98

Aggregates of tubular arrays associated with cysternae of endoplasmic reticulum were observed in untreated primary American form Burkitt's lymphoma. The tumor occurred in a white female child who died with severe central nervous system (CNS) involvement. Although the significance of the tubular structures and the mechanism by which they are formed remains unknown, the predilection of these structures for lymphoid and reticuloendothelial cells and their frequent association with either viral or suspected viral conditions cannot be overlooked. However, it is possible that the tubular structures may reflect an increased production of antibody protein in response to a viral antigen.
 ...
PMID:Cytoplasmic tubular arrays in cells of American Burkitt's type lymphoma. 17 97

Stimulated by a report on elevated IgA levels in nasopharyngeal carcinoma (NPC), we tested a total of 372 sera from patients with NPC, other carcinomas of head and neck or elsewhere, Burkitt's lymphoma (BL), infectious mononucleosis (IM) or healthy controls. The sera were titrated in indirect immunofluorescence tests for IgA antibodies to Epstein-Barr virus (EBV) capsid antigen (VCA) and to the diffuse (D) or restricted (R) components of the EBV-induced early antigen (EA) complex. The results proved NPC to be outstanding in that prior to therapy 93% of the patients tested revealed IgA antibodies to VCA and 73% to D, often at high titers which occasionally matched the corresponding IgG antibody levels. The EBV-specific IgA titers increased from stages I or II to stages III or IV; i.e. with the total tumor burden. Conversely, many of the NPC patients examined 2-6 years after initial therapy had only low levels of EBV-specific IgA or none at all, and the majority of those with high titers were known to have residual or recurrent disease. In contrast to untreated NPC patients, less than 5% of 73 patients with other carcinomas or of 76 healthy donors revealed VCA-specific IgA and even fewer EA-specific IgA; only 28% and 4% of 54 BL patients tested at admission had IgA antibodies to VCA and R, respectively, and 38% and 3% of 37 IM patients showed transient VCA- or D-specific IgA responses, all at generally low titers. While sera from untreated NPC patients often contained IgA antibodies also to herpes simplex type 1 virus, their incidence and range of low titers were similar to those obtained with sera from patients with other carcinomas or from healthy donors. It thus appears that the elevated IgA levels in NPC might be due to EBV-specific antibodies. Possible reasons for this unique response in NPC have been discussed.
 ...
PMID:Epstein-Barr virus-specific IgA serum antibodies as an outstanding feature of nasopharyngeal carcinoma. 17 20

Various biopsies from different European malignant lymphomas, two biopsies from nasopharyngeal carcinomas, and material from non-neoplastic lymph nodes were assayed for the presence of Epstein-Barr virus (EBV) DNA by nucleic acid hybridization. Reassociation kinetics of in vitro-labelled EBV DNA were studied in the presence of tumor DNA. The lymphomas tested included among others follicular lymphomas, germinocytomas, immunoblastic lymphomas and lymphoplasmacytoid immunocytomas. Epstein-Barr viral DNA was demonstrated within the two nasopharyngeal carcinoma biopsies as expected. A histologically typical Burkitt lymphoma as well as an immunoblastic lymphadenopathy with excessive plasmacytosis also contained EBV-DNA. The Burkitt biopsy revealed about 15 EBV genome equivalents per cell. Antibodies against EBV-specific antigens were highly elevated in the serum of this patient. The material of the patient with immunoblastic lymphadenopathy contained 2-3 EBV genome equivalents per cell.
 ...
PMID:Attempts to demonstrate virus-specific sequences in human tumors. IV. EB viral DNA in European Burkitt lymphoma and immunoblastic lymphadenopathy with excessive plasmacytosis. 17 27

Burkitt's lymphoma occurs mainly in parts of tropical Africa and has attracted the attention of experimental workers due to its epidemiological and clinical features, which indicate a viral etiology and a host immune response to the tumor. As a result of virological studies, Epstein-Barr virus (EBV) DNA has been demonstrated in almost all tested biopsies of African BL. This contrasts to the absence of EBV in all, or almost all, of the non-African Burkitt's lymphoma-like tumors, even though the number of tested tumors in this group is small, and to the lack of EBV in all other types of lymphoma or leukemia. Immunological studies have revealed the presence of antibodies to different EBV-associated antigens in all African patients with Burkitt's lymphoma. However the antibodies are not specific for Burkitt's lymphoma but are found in most adults all over the world, although at lower levels. They cannot therefore serve diagnostic purposes, but they can give prognostic information and occasionally give clues to the mechanisms behind late tumor recurrences, and possibly guide so-called immunotherapy. Burkitt's lymphoma patients contrast to appropriate control groups where some of the persons are anti-EBV seronegative, and this, together with the presence of EBV in Burkitt's lymphoma biopsies and the absence of EBV in other lymphomas, even though the cell type involved may be infectable by EBV in vitro and the tumor may arise in an EBV-carrying person, favors an etiological role in EBV in Burkitt's lymphoma and speaks against the "passenger" hypothesis, according to which EBV is picked up by the Burkitt's lymphoma cell which happens to be particularly suitable for EBV persistence. To explain the geographical distribution, a cofactor, such as certain forms of malaria, has been implied.
 ...
PMID:Burkitt's lymphoma - a human tumor model system for immunological studies. 17 35

The application of biochemical studies for the detection of Epstein-Barr virus (EBV)-DNA in human tumor cells is discussed. These studies resulted in the consistent demonstration of viral nucleic acid in African Burkitt's lymphoma biopsies and in epithelial tumor cells of nasopharyngeal carcinomas. The viral DNA resides within those cells regularly in multiple copies per cell. Besides these tumors our group detected significant concentrations of EBV-DNA in a German lymphoma patient revealing histological characteristics of Burkitt's lymphoma. Moreover, virus DNA was also found in a patient suffering from immunoblastic lymphadenopathy. More than 50 additional B-cell lymphomas and more than 40 biopsies from patients with Hodgkin's disease did not contain detectable amounts of EBV-DNA when tested by nucleic acid hybridization. A tentative scheme of EBV-induced pathogenesis is discussed.
 ...
PMID:Biochemical approaches to detection of Epstein-Barr virus in human tumors. 17 25

Epstein-Barr virus (EBV) DNA (17.7 genome equivalents/cell) was found in tumor tissue from an American patient with Burkitt's lymphoma who had never traveled outside the United States. A lymphoid cell line (NAB) containing the EBV genome was established from tumor tissue from this patient; characteristics of this cell line were described. Previous Burkitt's tumors found in Americans and examined by molecular hybridization were negative for EBV DNA. Our results suggested that EBV is associated with at least some American Burkitt's tumors.
 ...
PMID:Epstein-Barr virus in an American patient with Burkitt's lymphoma: detection of viral genome in tumor tissue and establishment of a tumor-derived cell line (NAB). 17 7

Tumour biopsies from Burkitt lymphoma patients, as well as human nasopharyngeal carcinoma cells growing in athymic mice, contain Epstein-Barr virus DNA as covalently closed circular DNA. In addition integrated viral DNA sequences seem to be present.
 ...
PMID:Intracellular forms of Epstein-Barr virus DNA in human tumour cells in vivo. 17 97

A case of intracranial Burkitt's lymphoma is reported in a child whose symptoms began at 3 months of age with a definite histologic diagnosis established at 18 months. Serologic studies demonstrated high antibody titers to Epstein-Barr virus (EBV) in the patient and in four out of five members of the immediate family. The patient also demonstrated immunity to antigens derived from African Burkitt's lymphoma cell lines. The autopsy findings strongly support the case for the primary intracranial origin of the neoplasm and a perinatal infection with EBV is probable in this case.
 ...
PMID:Primary intracranial Burkitt's lymphoma in an infant. 17 69

A human hematopoietic cell line (U-937) with exceptional characteristics was derived from a patient with generalized histiocytic lymphoma. The morphology of the cell line was identical to that of the tumor cells in the pleural effusion from which the line was derived. Since Epstein-Barr virus (EBV) carrying diploid lymphoblastoid cell lines unrelated to the tumor population often become established in vitro from non-Burkitt lymphoma explants, several parameters were studied to discriminate the U-937 from such lines: morphology in vitro, growth characteristics, cytochemistry, surface receptor pattern, Ig production, lysozyme production, beta2-microglobulin production, presence of EBV genome and karyotype. In all these respects U-937 differed from prototype lymphoblastoid cell lines. The histiocytic origin of the cell line was shown by its capacity for lysozyme production and the strong esterase activity (naphtol AS-D acetate esterase inhibited by NaF) of the cells. It is therefore concluded that the U-937 is a neoplastic, histiocytic cell line.
 ...
PMID:Establishment and characterization of a human histiocytic lymphoma cell line (U-937). 17 11


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>