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

Adenosine deaminase (ADA) activity has been measured in the lymphoblasts of 23 untreated patients with acute lymphoblastic leukemia and related to the presence or absence of immunologic cell surface markers. The mean ADA activity in the acute lymphoblastic leukemia population as a whole was increased fourfold over that in normal lymphocytes. 9 of the 23 patients were classified as thymus-derived (T-) cell acute lymphoblastic leukemia on the basis of erythrocyte rosette positivity; the remaining 14 patients had null-cell leukemia. The mean ADA activity (ADA U/mg protein) of T-cell lymphoblasts (102 U) was 3 times higher than the mean of null lymphoblasts (30 U). This difference is statistically significant (P less than 0.02). Measurement of ADA activity offers a biochemical method of distinguishing between immunological subtypes of lymphoblasts which may be of prognostic and therapeutic value.
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PMID:Correlation of adenosine deaminase activity with cell surface markers in acute lymphoblastic leukemia. 30 13

Adenosine deaminase (ADA) activity has been assessed in lymphoid cells of 23 patients with acute lymphoblastic leukaemia (ALL) in order to attempt a further characterization of ALL cells in addition to the well known cytochemical and immunological T and B lymphoid cell markers. ADA activity did not show any correlation with the immunological characterization of the patients investigated; in fact a wide range of ADA activity was observed with levels ranging from 0 to 32 U in T-ALL patients and nearly similar values (from 1.8 to 36 U) in the group of non T--non B ALL cases. Normal values ranged from 2 to 5 U (mean 2.9 U; s.d. +/- 0.8). Some cytochemical patterns (acid phosphatase and PAS) appeared well correlated with T markers of lymphoid cells, whereas they showed no significant relationship with ADA activity.
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PMID:Adenosine deaminase activity in acute lymphoblastic leukaemia: cytochemical, immunological and clinical correlations. 35 73

Adenosine deaminase (adenosine aminophydrolase, ADA) activity was found to be low in lymphocytes of chronic lymphatic leukaemia (CLL) patients compared to normal lymphocytes. This was determined on 42 controls and 49 CLL patients. The mean activity in normal lymphocytes was found to be 4.35 +/- 3.34 mumol/h/10(8) cells while in CLL cells it was 2.45 +/- 2.54 mumol/h/10(8) cells.
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PMID:Adenosine deaminase (ADA) activity in lymphocytes of normal individuals and patients with chronic lymphatic leukaemia. 87 26

Adenosine deaminase (EC 3.5.4.4., ADA) has been measured in the blast cells of 36 patients with acute lymphoblastic, acute myeloid, chronic myeloid and chronic myeloid blast crisis leukaemia. Particularly high levels were found in acute lymphoblastic and chronic myeloid blast crisis patients. The measurement of ADA may be useful diagnostically in the undifferentiated acute leukaemias and in detecting the early onset of blast crisis in chronic myeloid leukaemia. Possible reasons for the elevation of ADA in malignant cells are discussed.
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PMID:Adenosine deaminase activity in leukaemia. 105 44

Adenosine deaminase (ADA) deficiency is associated with a fatal severe combined immunodeficiency. Because most patients do not have a suitable marrow donor, the introduction of a normal ADA gene into the patient's marrow cells is a potentially useful alternative therapy. To identify vectors that provide optimal gene expression in human hematopoietic cells, we investigated retroviral vectors containing the ADA gene under the transcriptional control of the promoter/enhancers of Moloney murine leukemia virus, the simian virus 40 early region, the cytomegalovirus immediate-early gene, the lymphotropic papovavirus, and the human beta-globin gene. ADA expression from these vectors was monitored in the ADA- human histiocytic lymphoma cell line DHL-9, and in the multipotential chronic myeloid leukemia cell line K562. ADA expression in infected K562 cells was also measured after induction of megakaryoblastic differentiation by phorbol ester, and after induction of erythroid differentiation by sodium n-butyrate or hemin. In these hematopoietic cell lines, the vectors that contained ADA controlled by either the Moloney murine leukemia virus promoter (LASN) or the cytomegalovirus promoter (LNCA) expressed ADA at much higher levels than the other vectors tested. Furthermore, in K562 cells infected with LASN and LNCA vectors, induction of terminal differentiation resulted in the same or higher level expression of ADA. These cell lines have permitted the evaluation of transduced gene expression in proliferating and differentiating hematopoietic cells that provide a model for bone marrow-targeted gene therapy.
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PMID:Expression of human adenosine deaminase from various strong promoters after gene transfer into human hematopoietic cell lines. 275 48

Adenosine deaminase (ADA) was assayed in plasma from 14 patients with adult T-cell leukemia (ATL) (eight with acute ATL and six with smoldering or chronic ATL), 20 male family members (ten were anti-ATLA antibody positive and the other ten negative), and 25 normal individuals. ADA activity was uniformly higher in plasma from patients with ATL than normal controls. This enzyme activity significantly increased in acute ATL in comparison to smoldering or chronic ATL. In families of ATL patients, no statistical difference in ADA activity between the anti-ATLA antibody-positive group and -negative group could be discerned. The enzyme activity in a patient with acute ATL, after a bone-marrow transplant, rapidly increased as leukemic cells increased in peripheral blood. These findings indicate that the levels of ADA activities in plasma from ATL patients reflect the condition of this disease. Thus, measurement of this enzyme activity offers a further parameter to distinguish subtypes of ATL, and is of prognostic and therapeutic value.
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PMID:Adenosine deaminase in plasma of patients with adult T-cell leukemia (ATL): correlation between enzyme activity and the ATL subtypes. 299 23

This report discusses a case of T cell chronic lymphocytic leukemia (T-CLL) in an elderly white man whose lymphocytes expressed a post-thymic phenotype except for the coexpression of T4 and T8 on 80% to 95% of the cells. Because of the uncommon phenotype, in vitro functional assays were performed that showed decreased mitogenic responses but normal helper activity for B cell immunoglobulin secretion and normal suppressor activity of lectin-induced mitogenesis. Morphologic evaluation by both light and electron microscopy and cytochemical staining were consistent with the "knobby" type T-CLL. Adenosine deaminase and terminal deoxynucleotidyl transferase (TdT) levels were low, but the acetylcholinesterase level was normal, which is consistent with the peripheral T cell phenotype. The patient underwent splenectomy, and the spleen cells showed very low levels of T3 and T4 by immunoperoxidase and undetectable levels by immunofluorescence. The morphology of the splenic infiltrate was not significantly different from that in the initial bone marrow. Human T cell leukemia virus (HTLV) antigen and antibody tests were negative. The cells in this leukemia apparently are derived from a transitional stage of maturation between the cortical and medullary thymocyte. A small subset of lymphocytes of identical phenotype to this leukemia has been identified in normal individuals.
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PMID:T cell chronic lymphocytic leukemia with lymphocytes of unusual immunologic phenotype and function. 387 Nov 60

Activity of terminal deoxynucleotidyl transferase (TdT), adenosine deaminase, and 5'nucleotidase and the cellular concentration of glucocorticoid (dexamethasone) receptor were determined in 25 patients with acute non-lymphocytic leukaemia. All patients were treated according to a common protocol. Increased activity of TdT (greater than 0.1 unit/microgram DNA) was found in 11 patients. This group of patients was shown to have higher remission and survival rates (p = 0.06) compared with patients with low activity of TdT. The glucocorticoid receptor concentration of the leukaemic blast cells ranged from 0 to 0.94 fmol/microgram DNA. Thirteen patients had blast cells with a glucocorticoid receptor concentration over 0.22 fmol/microgram DNA. These patients had significantly increased remission and survival rates (p = 0.006) compared with those with a low receptor concentration. This finding cannot be explained by a difference in sensitivity to glucocorticoids since these were not used as therapeutic agents. Adenosine deaminase and 5'nucleotidase activities both varied within two orders of magnitude. No correlation could be found between activities of these enzymes and remission or survival rate. These results show that measurements of TdT activity and the glucocorticoid receptor concentration yield valuable prognostic information in acute non-lymphocytic leukaemia.
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PMID:Glucocorticoid receptor concentrations and terminal transferase activity as indicators of prognosis in acute non-lymphocytic leukaemia. 626 1

Adenosine deaminase (ADA) and ecto-5'-nucleotidase (5'-N) activities were examined in peripheral leukocytes from patients with leukemias, including nine patients with chronic myeloid leukemia (CML) in blast crisis. Four of none cases of CML in blast crisis were myeloid and the remaining lymphoid morphologically. The diagnosis of CML in lymphoid blast crisis was further contributed by the measurement of terminal deoxynucleotidyl transferase (TdT) activity. In all four cases of lymphoid blast crisis and one of myeloid blast crisis, leukemia cells had high 5'-N activity, while there was a little or no detectable activity in those from four cases of myeloid blast crisis and all of CML in chronic phase. ADA activity was high in seven of nine patients with blast crisis. Taken together, leukemia cells from two cases of lymphoid blast crisis had high ADA and 5'-N activities comparable to those in acute lymphocytic leukemia (ALL) cells. In contrast, the enzyme activities of leukemia cells from all but one patient in myeloid blast crisis were in a range similar to acute myeloid leukemia cells. The implications of these findings are as follows: (1) 5'-N may be used as a new biochemical marker of CML in lymphoid blast crisis. (2) Some lymphoid cells of CML in blast crisis have high ADA, 5'-N, and TdT activities and thus are very similar to ALL cells.
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PMID:Adenosine deaminase and ecto-5'-nucleotidase activities in various leukemias with special reference to blast crisis: significance of ecto-5'-nucleotidase in lymphoid blast crisis of chronic myeloid leukemia. 627 2

Adenosine deaminase (ADA), ecto 5' nucleotidase (5'NT), purine nucleoside phosphorylase (PNP) and terminal deoxynucleotidyl transferase (TdT) were measured in the cells of patients with acute or chronic T cell leukaemia and compared with normal putative prothymocytes (large, blast-like cortical thymocytes), cortical and medullary thymocytes and peripheral blood T lymphocytes. Distinct patterns of enzyme activities were found in the individual types of T cell leukaemia. Mean ADA, TdT and 5'NT activities in thymic acute lymphoblastic leukaemia (Thy-ALL) were 41.9 u/10(8) cells, 31.1 u/10(8) cells and 4.7 u/10(6) cells respectively; in chronic T cell leukaemia they were 7.1 u/10(8) cells, 0.6 u/10(8) cells and 18.1 u/10(6) cells respectively. Mean PNP activity was similar between these two groups of leukaemia (68.6 u/10(6)cells in Thy-ALL and 77.9 u/10(6) cells in chronic T cell leukaemia). The activities of these four enzymes in OKT4+ chronic T cell leukaemia did not differ significantly from those in the OKT8+ chronic T cell leukaemia cases. The activities of TdT, ADA, PNP and 5'NT in Thy-ALL closely resembled those in normal immature thymocytes, and in the chronic T cell leukaemias showed a similar pattern of enzyme activities to that of mature T lymphocytes. These findings are consistent with surface phenotypic studies of T cell malignancies which suggest that different T cell leukaemias represent malignant proliferation of T cell clones arrested at different stages of T cell differentiation. They also demonstrate the value of biochemical markers in defining the different subtypes of acute and chronic leukaemia.
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PMID:Comparison of purine degradative enzymes and terminal deoxynucleotidyl transferase in T cell leukaemias and in normal thymic and post-thymic T cells. 630 93


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