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Query: UMLS:C0023418 (leukemia)
 93,477 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

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

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

Murine leukemia viruses capable of malignant transformation of mink tissue culture cells have been isolated from an AKR thymoma cell line and from a spontaneous reticulum cell sarcoma in an NIH Swiss mouse partially congenic for the AKR ecotropic virus-inducing locus Akv-2. In contrast to the recently described mink cell focus-inducing strains of murine leukemia virus, at least one of the two transforming strains is replication defective. Nonproducer mink cells carrying the genome of the transforming virus of AKR origin have been isolated, and pseudotype transforming viruses generated.
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PMID:Isolation of transforming murine leukemia viruses from mice with a high incidence of spontaneous lymphoma. 19 31

Although the term thymic hyperplasia is used most commonly to indicate the occurrence of germinal centers in the thymus, cognizance must be taken of the fact that such centers may occur in apparently normal thymuses in both children and adults. A concept of thymic compartmentalization is proposed with origin of germinal centers in the perivascular space (extraparenchymal compartment) of the thymus. These germinal centers contain a high percentage of B lymphocytes in contrast to the true thymic parenchyma. Although the significance of germinal centers in the thymus parenchyma. Although the significance of germinal centers in the thymus in myasthenia gravis remains controversial, removal of nonneoplastic thymus in this condition is of proven therapeutic value. A variety of neoplasms originating in the thymus have previously been lumped together under the single term "thymoma." It is apparent, however, that thymoma, thymic carcinoid, various lymphomas, and germ cell tumors that arise in the thymus differ not only pathologically but also in their clinical behavior. Thymoma is regarded as an epithelial neoplasm and ultrastucturally is characterized by many desmosomes and tonofilaments. The lymphocytes do not behave in a malignant manner, and lymphomas of the thymus should be sharply separated from true thymoma. Poorly differentiated thymic carcinoma and histiocytic lymphoma may be distinguishable only by the electron microscopic demonstration of desmosomes and filaments in the thymic carcinoma. The evidence that Hodgkin's disease of the thymus ("granulomatous thymoma") is not a variant of thymoma appears overwhelming. Lymphoblastic lymphoma of the thymus is a distinctive neoplasm that is especially prevalent in teenage males. High levels of terminal transferase characterize the lymphoblasts and there is a striking tendency for leukemia to occur. Thymic carcinoid is usually nonfunctional, although one-third of the reported cases are associated with Cushing's syndrome. On light microscopy a ribbon pattern and punctate necroses are characteristic of thymic carcinoids. Electron microscopic demonstration of many dense core granules is invaluable in establishing this diagnosis. An important clue to the diagnosis of thymic seminoma (a neoplasm that shows the same radiosensitivity as its testicular counterpart) is the frequent presence of epithelioid and giant cell granulomas and germinal centers. Separation of the various thymic neoplasms described not only is justifiable on pathologic grounds but is often essential for appropriate patient investigation and treatment.
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PMID:Thymic hyperplasia and neoplasia: a review of current concepts. 36 41

Young AKR mice grafted i.v. with 10(1) or 10(3) cells from spontaneous AKR thymomas were treated with repeated i.v. injections of BCG or subcutaneous injections of irradiated AKR thymoma cells. BCG often cured mice from graft leukemia, whereas the effect of irradiated thymoma cells was less effective. Mice that did not develop graft-leukemia after graft of 10(1) leukemia cells and BCG treatment showed a spontaneous leukemia in 30% of the cases later. Ninety percent of nongrafted mice developed spontaneous leukemia whether BCG-treated or not. General immune reactivity as assessed in individual mice by T and B lymphocyte mitogen tests as well as the hemolytic plaque-forming cell assay had no clear correlation to the effects of immune adjuvants in respect to survival. In contrast, occurrence of self-directed immune reactions were clearly correlated to survival and cure of grafted and BCG-treated mice as revealed by assays both in vitro and in vivo. However, 13 to 25% of the mice apparently cured of leukemia developed a wasting-like syndrome that sometimes terminated in death. The immplications of self-directed immune reactions as mediators of the anti-neoplastic effects of immunoadjuvants.
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PMID:Immunoadjuvant treatment of primary grafted and spontaneous AKR-leukemia. I. Treatment efficiency correlated to autoimmune reactivity. 37 5

The genome of a recombinant murine leukemia virus capable of inducing focal areas of morphological alteration in mink lung fibroblasts was studied by heteroduplex analysis. The dual-tropic recombinant virus was isolated from a thymoma cell line (Th16.3) and is referred to as BALB/Moloney mink cell focus-inducing virus (BALB/Mo-MCF virus). The nucleic acid sequences of RNA from virions obtained from either a thymoma cell line (Th16.3) or a clonal isolate (BALB/Mo-MCF81) were compared with the genomes of ecotropic and xenotropic viruses. The following inferences were drawn (i) A single nonhomologous region (substitution loop alpha) of about 0.7 kilobase was observed in a heteroduplex formed between Moloney murine leukemia virus complementary DNA (cDNA) and BALB/MoMCF81 RNA. This nonhomology region was mapped between 1.71 and 2.40 kilobases from the 3' end of the genome. (ii) The predominant class of heteroduplexes formed between virion RNA obtained from the thymoma cell line (Th16.3) and Moloney murine leukemia virus cDNA showed a substitution loop similar to that observed with the RNA obtained from a cloned isolate, BALB/Mo-MCF81. However, there were other molecules with additional regions of nonhomology. (iii) Heteroduplexes formed between NZB xenotropic RNA and ecotropic Moloney murine leukemia virus cDNA exhibited four major nonhomology regions extending 0.75 to 1.46, 2.0 to 2.8, 3.6 to 4.3, and 7.4 to 7.9 kilobases from the 3' end of the genome. (iv) The MCF-specific substitution loop alpha (1.71 to 2.40 kilobases) appeared as a duplex region when NZB xenotropic RNA was hybridized to cDNA transcripts synthesized by virions obtained from thymoma cell line Th16.3. The position of the other substitution loops observed in a heteroduplex formed between NZB xenotropic RNA and Moloney murine leukemia virus cDNA was not affected. (v) Heteroduplexes formed between xenotropic BALB virus 2 cDNA and NZB xenotropic RNA demonstrated a large degree of nucleic acid sequence homology. Of the 29 heteroduplexes examined, 24 appeared to be homoduplexes, and in the remaining 5 heteroduplexes only one region of nonhomology located between 3.2 and 3.8 kilobases from the 3' end of the genome could be identified. Hybridization of BALB virus 2 xenotropic RNA to NZB xenotropic cDNA followed by digestion with single-strand-specific nuclease S1 showed an 80% sequence homology.
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PMID:Genome organization of retroviruses. VI. Heteroduplex analysis of ecotropic and xenotropic sequences of moloney mink cell focus-inducing viral RNA obtained from either a cloned isolate or a thymoma cell line. 51 8

Leukaemia cells of C12/0 line, derived from Gross virus-induced W/Fu rat thymoma, have been successfully maintained in a completely synthetic, serum-free RPMI 1640 medium. The cells propagated as good as in serum-supplemented medium, though they could not grow from a low cell density. Cells adhered to the substratum and did not survive. This problem was overcome by use of silicone-coated substratum, or of microexudate from C12/0 cells adsorbed on the substratum. The cells underwent degeneration soon after they reached their maximum density. C12/0 cells released macromolecules might possibly have both growth-promoting and toxic effect on the cell itself.
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PMID:Rat leukaemia cell line grown on a chemically defined medium. 100 38

A case of epithelial thymoma occurring synchronously with Philadelphia chromosome-positive chronic myelogenous leukemia and urinary bladder carcinoma in a 76-year-old man is described. Thymomas have been associated with numberous hematologic, collagen-vascular and autoimmune disease states, as well as with an increased incidence of nonthymic malignancy. Human thymoma-associated leukemia is, however, extremely unusual, despite the well-documented role of the thymus in leukemogenesis in experimental animals. No previous literature reports of thymoma associated with chronic myelogeneous leukemia were found. A review of long-term followup data of surviving thymoma patients is necessary to determine if an increased propensity to develop leukemia is present in present in patients with thymoma.
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PMID:Thymoma and chronic myelogenous leukemia: a case report. 106 82

Rosette formation with mouse erythrocytes and other cell-surface markers were examined on lymphocytes from patients with a variety of primary immunodeficiency and lymphoproliferative disorders. Mouse erythrocyte rosette-forming cells and lymphocytes with surface immunoglobulins were regularly absent in patients with Bruton type agammaglobulinaemia, immunodeficiency and thymoma syndrome and severe combined immunodeficiency disease. However, they were present in normal or low numbers in patients with common variable immunodeficiency, selective IgA deficiency and ataxis telangiectasia. Lymphocytes from patients with acute lymphoblastic leukaemia Sezary syndrome and mycosis fungoides made no or few rosettes with mouse erythrocytes. Increased numbers of mouse erythrocyte rosette-forming cells were present in patients with chronic lymphocytic leukaemia and Waldenstrom's macroglobulinaemia. The significance of the mouse erythrocyte rosette as a B-cell marker in the analysis of primary immunodeficiency and lymphoproliferative disorders is discussed.
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PMID:Rosette formation with mouse erythrocytes. III. Studies in patients with primary immunodeficiency and lymphoproliferative disorders. 106 59

The nature of the immunological defect in patients with hypogammaglobulinemia associated with a thymoma was investigated using a technique established to study the differentiation of lymphocytes into immunoglobulin synthesizing and secreting cells. Exhaustively washed peripheral blood lymphocytes were cultured for 7 days in RPMI-1640 medium supplemented with fetal calf serum in the presence of the lectin, pokeweed mitogen. The IgG, IgA, and IgM synthesized and secreted into the medium were measured by competitive double antibody radio-immunoassays. Twenty-two normal individuals synthesized 1625 ng of IgG, 1270 ng of IgA, and 4910 ng of IgM per 2 million lymphocytes in culture. In contrast, the three patients with hypogammaglobulinemia and a thymoma synthesized less than 100 ng of each class of immunoglobulin. When lymphocytes from 2 of the 3 patients studied were cocultured with normal lymphocytes and pokeweed mitogen, the synthesis of immunoglobulin by normal lymphocytes was depressed by a factor of 66 to 97%. Co-cultue of purified T cells from the hypogammaglobulinemic patients with normal lymphocytes resulted in an 87% suppression of immunoglobulin synthesis by the normal cells. However, no suppression of immunoglobulin synthesis was observed when preparations of B cells and macrophages depleted of T cells from the hypogammaglobulinemic patients were co-cultured with normal lymphocytes. In addition, in control studies no such suppression of immunoglobulin synthesis was seen when normal cells were co-cultured with lymphocytes from unrelated normals, patients with isolated IgA deficiency, patients with chronic lymphocytic leukemia or patients with the Sezary syndrome, a T cell leukemia nor were they inhibited when incubated with T cells from unrelated normals. These observations suggest that in some patients the hypogammaglobulinemia associated with a thymoma may be caused or perpetuated by an abnormality of regulatory T cells which suppress the maturation of lymphocytes into antibody producing cells.
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PMID:Suppressor T cells in the pathogenesis of hypogammaglobulinemia associated with a thymoma. 108 79


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