Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0023418 (leukemia)
 93,477 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Activity of the enzyme terminal transferase (TdT) has been localised in normal human bone-marrow lymphocytes. These cells may represent a prothymocyte population, which, on malignant transformation, may give rise to acute lymphoblastic leukaemia, and to some cases of chronic granulocytic leukaemia in the blastic phase.
 ...
PMID:Terminal transferase in human bone-marrow lymphocytes. 5 82

On the basis of membrane marker analysis with an antiserum made against acute lymphoblastic leukaemia and other immunological markers it is suggested that some chronic myeloid leukaemias (C.M.L.) and some acute lymphoblastic leukaemias (A.L.L.) originate in a common target cell or precursor. This is possibly a pluripotential stem cell or a closely related derivative. These leukaemic cells retain their undifferentiated membrane characteristics C.M.L. patients in blast crisis who are A.L.L.-antigen-positive and have terminal transferase enzyme activity might benefit from therapy usually given in typical Philadelphia-chromosome-negative A.L.L.
 ...
PMID:Target cell in chronic myeloid leukaemia and its relationship to acute lymphoid leukaemia. 6 4

A child presented with "acute leukemia" in which the blast cells resembled lymphoblasts and had negative cytochemical staining (PAS, Sudan black, and myeloperoxidase). Remission was induced and typical adult-type chronic myelogenous leukemia (CML) followed. Cytogenetic studies initially and during remission and subsequent "acute leukemia" relapses revealed the presence of the Philadelphia chromosome abnormality. Terminal transferase assay performed on peripheral blood blast cells was markedly elevated and soft agar culture growth parameters were typical of acute lymphoblastic leukemia T and B cell marker studies revealed no markers. This case report with supportive laboratory studies suggests that a cell line with lymphoid characteristics may predominate during acute leukemic transformation. This type of subclassification of leukemia may be of importance in therapeutic planning.
 ...
PMID:Lymphoblastic conversion in chronic myelogenous leukemia. 7 81

In the present study, terminal deoxynucleotidyltransferase was examined in the peripheral blood and (or) bone marrow of 115 children with a variety of neoplastic, hematologic, and other unrelated disorders. Terminal deoxynucleotidyltransferase activity was present at 4.08+/-0.74 U/108 cells in 23 morphologicall normal bone marrow samples from childhood controls. Terminal transferase was present at greater than 23 U/108 nucleated cells and at greater than31 U/108 blasts in the bone marrow of all children with acute lymphoblastic leukemia studied at initial diagnosis and at disease relapse. Terminal deoxynucleotidyltransferase was detectable at low levels, less than 7.5 U/108 cells, in all remission marrow smaples. Bone marrow terminal transferase activity was markedly elevated in all untreated acute lymphoblastic leukemia patients, whereas low levels which were difficult to interpret were present in the peripheral blood samples of two patients at diagnosis and six patients at relapse who had low absolute lymphoblast counts. Because of greater variation in the lymphoblast content of peripheral blood, bone marrow assays are more reliable in detecting disease activity. Marrow terminal deoxynucleotidyltransferase values obtained during the active phase of acute lymphoblastic leukemia were significantly greater than those found in other types of leukemia, bone marrow malignancies, and hematologic disorders. Terminal transferase determinations in blast cells of two patients with leukemic conversion of non-Hodgkin's lymphoma and in tumor cells from one patient with Burkitt's lymphoma were within the control range. These dat further define the usefulness of terminal deoxynucleotidyltrnasferase assay in the differentiation and classication of hematologic malignancies.
 ...
PMID:Terminal deoxynucleotidyltransferase distribution in neoplastic and hematopoietic cells. 26 45

Induction of leukemia in nude mice (BALB/c nu/nu) was attempted by inoculation with a human acute lymphocytic leukemia cell line (Ichikawa strain, maintained in an ascitic form in our institute). Inoculation of the cells i.v. in normal nude mice failed to produce leukemia. However, conditioning with whole-body irradiation (500 rads) resulted in induction of leukemia after i.v. inoculation, especially when such inocluation was performed 3 days after irradiation. The correlation of survival to inoculum size (10(5) to 10(5)) was inversely exponential. Leukemic infiltration was noted in the spleen, lymph nodes, bone marrow, meninges, liver, kidneys, etc., as seen in human leukemia. These cells retained their original cytological characteristics, ultrastructural features, and surface markers and revealed high terminal deoxynucleotidyltransferase activity as T-derived cells. Chromosome analysis revealed aneuploidy in a hypotetraploid range with a mode of 88 chromosomes.
 ...
PMID:Leukemic distribution of a human acute lymphocytic leukemia cell line (Ichikawa strain) in nude mice conditioned with whole-body irradiation. 27 39

The blast cells of 19 patients with Ph1-positive chronic granulocytic leukaemia (CGL) in blast crisis (BC) were studied by means of several techniques: morphology, cytochemistry, ultrastructure, surface markers and the enzyme terminal transferase. Cells of BC were, in most case, extremely undifferentiated by morphology and cytochemistry. Our data showed that in 80% of cases the cells in BC were myeloid and in 20% they were "lymphoblastic". The M1, M2 and M3 forms (FAB classification) were rare in CGL BC compared with acute myeloid leukaemia (AML). A megakaryoblastic type was seen in 15% of BC cases; the existence of this form could only be demonstrated by electron microscopy. The limphoblastic BC cells were, as in acute lymphoblastic leukaemia (ALL), positive with Greaves' anti-ALL serum and had elevated levels of terminal transferase. A case of a 17-year old boy presenting as ALL, reverting to chronic-phase CGL after complete remission and developing terminally a myeloid BC is described in detail. This case helps to illustrate a new form of natural history of CGL unveiled by the present study.
 ...
PMID:Ultrastructural, cytochemical and surface marker analysis of cells during blast crisis of chronic granulocytic leukaemia. 28 4

Membrane markers (anti-ALL and anti-Ia antisera) and an enzyme marker (terminal transferase) have been used to define an L-type or "lymphoid" type of acute transformation in chronic myeloid leukaemia and Ph1 positive acute leukaemia. Patients with L-type ("lymphoid") blasts responded to regimens including vincristine and prednisolone (VP). The markers showed better correlation with survival than did the morphology of blasts. The clinical course of patients was variable; elimination Ph1 positive clone (and hypoplasia), return to the chronic phase and relapses (including meningeal leukaemia) were observed. In contrast, patients with myeloid blasts ("M" type of blast crisis) failed to respond to vincristine and prednisolone.
 ...
PMID:Lymphoid blast crisis in chronic myeloid leukaemia and Philadelphia positive acute lymphoid leukaemia. 28 5

Forty-four patients with Ph positive leukemia (36 developing blast crisis after chronic phase and eight presenting in acute leukemia) were classified into subgroups on the basis of reactivity of blasts with an anti-serum made against non-T,non-B acute lymphoid leukemia (ALL+), levels of terminal transferase enzyme (TdT+) and morphology. Positivity with anti-ALL serum was the most sensitive and reliable marker, and TdT was an important aid. The presence of "lymphoid" blasts in blast crisis of CML was related to the response to chemotherapy incorporating Vincristine and Prednisolone (VP). Patients with ALL+ blasts frequently (14 of 15 cases) responded to therapy while 21 of 25 patients who had no ALL+ blasts failed to respond. The clinical course of the ALL+ patients was variable: eight patients remitted with return to the appearances of the chronic phase; four patients demonstrated elimination of the Ph1 positive clone with hypoplasia and this was followed by normal (Ph1 negative) marrow regeneration in two. Subsequent relapse was of either the ALL+ "lymphoid" or the ALL-myeloid type. A regimen incorporating VP should be the treatment of choice in "lymphoid" blast crisis of CML.
 ...
PMID:Relation of "lymphoid" phenotype and response to chemotherapy incorporating vincristine-prednisolone in the acute phase of Ph1 positive leukemia. 28 75

Two children who presented initially with a lymphoid malignancy were noted to develop recurrences with myeloid features late in the course of their disease. In both cases, evidence of lymphoid differentiation was present in the myelogenous cells that were Ph1 chromosome negative. The first patient had acute myelogenous leukemia and developed a recurrence with morphologic features of acute myelogenous leukemia. Terminal transferase was present in the myelogenous blasts. The second patient initially had a diffuse lymphoblastic non-Hodgkin lymphoma. During the course of her illness she developed a myeloproliferative disorder characterized by basophilic meningitis, splenomegaly, and hypereosinophilia. Lymphocyte T-cell (E-rosette) markers were present on the eosinophils. These observations lend further support to the hypothesis of varying lymphoid and myeloid differentiation in certain cases of leukemia.
 ...
PMID:Myelogenous leukemia evolving during the course of lymphoid malignancy in children. 29 24

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.
 ...
PMID:Thymic hyperplasia and neoplasia: a review of current concepts. 36 41


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