Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.5.4.4 (adenosine deaminase)
 5,136 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The adenosine deaminase, 5'-nucleotidase, AMP-aminohydrolase and adenylate kinase activities and thymostimulin influence on these indices in vivo were studied in rat thymus and spleen lymphocytes in the latent period of DMBA-induced mammary carcinogenesis. The adenosine deaminase activity was established to increase while 5'-nucleotidase and AMF-aminohydrolase activity to decrease in the thymocytes of intact animals treated with thymostimulin; the adenylae kinase activity of spleen lymphocytes decreased as compared with that in the rats not treated with the preparation. The dynamics of changes in the investigated enzymes in activities in lymphocytes was of wave-like pattern in the latent period. The treatment of animals with thymostimulin in this period normalized adenosine deaminase activity and decreased the activity of the other enzymes in these cells.
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PMID:[Influence of thymostimulin on the activity of certain enzymes of adenosine and AMP metabolism in lymphocytes of rats with mammary cancer]. 628 53

Studies were undertaken on the activity of adenosine deaminase (ADA) and metabolic enzymes of AMP in the spleen and thymus cells of rats with DMBA-induced carcinogenesis of the mammary glands and on the effect of thymostimulin (TS) on this activity. In addition, we investigated the activity of ADA in the peripheral blood lymphocytes of the patients with premalignant diseases and cancer of the mammary glands (Stages I-IV) as well as the possibility of its enhancement by TS. The disturbances of these enzyme activities characterized by a decrease in ADA activity and an increase in activity of the AMP metabolism enzymes, predisposed for adenosine accumulation in lymphoid cells. Injection of TS normalized the ADA activity and decreased the activity of the AMP metabolic enzymes. Analogous results were obtained in the studies of ADA activity in the human materials. With the human tumor growth the in vitro effect of TS on the lymphocyte ADA activity decreased. We may suggest that measurement of the ADA activity in the lymphocytes may serve as a reliable tool to control the state of immune system and the effectiveness of immunotherapy with the thymic humoral factors.
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PMID:The lymphocyte activity of adenosine deaminase and enzymes of AMP metabolism in mammary carcinogenesis: the effect of thymostimulin. 632 26

Lymphocyte populations of BALB/c mice were obtained from bone marrow, thymus, spleen, peripheral blood and lymphoid nodes. Subpopulations of thymocytes and bone marrow T-lymphocyte precursors were separated by density gradient centrifugation. The activity of adenosine deaminase (ADA) undergoes a marked increase during the evolution of bone marrow T-cell precursors to immature thymocytes, and a decrease with thymocytes maturation. The peripheral blood lymphocytes (PBL) present the lower activity of the enzyme, and lymphocytes from spleen (SL) and lymphoid nodes (LNL) show activity in the order of that in mature thymocytes. The activity of purine nucleotide phosphorylase (PNP) in the different lymphocytes populations experiments a very little variation with the T-lymphocyte differentiation. With the evolution of T-lymphocyte precursors to immature thymocytes the 5'-nucleotidase (5'-NT) activity experiment a 2-fold decrease. The thymocytes maturation is correlated with an increase in the activity of 5'-NT. The PBL present the maximal activity of the enzyme, whereas in spleen and LNL its levels of activity are in the range of that in mature thymocytes and bone marrow T-cell precursors respectively.
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PMID:The distribution of adenosine deaminase, purine nucleotide phosphorylase and 5'-nucleotidase in subpopulations of thymocytes, bone marrow cells and other lymphoid organs in mice. 632 33

The activities of adenosine deaminase, purine nucleoside phosphorylase, membrane 5'-nucleotidase and DNA content in thymus and spleen lymphocytes as well as the immune function of T and B lymphocytes of the spleen of C3HA mice with o-AAT-induced hepatomas were studied 1, 3 weeks and 3, 8, 12 months after o-AAT treatment was instituted. In the early stages of the hepatocarcinogenesis (up to 3 months), the elevation of the activity of all the enzymes and DNA content in thymocytes and T and B lymphocytes was observed. These changes coincided with the enhancement of the immune responses that manifested in the increased content of PFC, EA-RFC and high response to PHA and Con A. In the late stages, the decreased activities of purine nucleosides and nucleotide metabolizing enzymes correlated with disturbances of lymphocyte differentiation and lowering of the host immune response.
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PMID:[Changes in purine metabolism and in the immune response in the thymic and splenic lymphocytes of C3HA mice during chemical hepatocarcinogenesis]. 633 63

A human thymus-leukemia-like antigen has been identified that is antigenically distinct from T6/HTA-1. This was accomplished with a rabbit antiserum (513) which was prepared against lymphoblasts that were E rosette negative (E-), human thymus antigen positive (HuTA+), cALLA-, DR-, SmIg- from a patient who presented with a mediastinal mass and a WBC count of 130 X 10(9) cells/1. Following absorption with B cell and "null" cell lines, 513 exhibited prominent reactivity with a membrane antigen that was present on normal thymocytes and lymphoblasts from 11 of 13 patients with T cell ALL and 1 of 16 patients with common ALL, but was not detected on normal peripheral blood lymphocytes, normal bone marrow cells and leukemic lymphoblasts with an undifferentiated phenotype. SDS-PAGE analysis of this antigen indicated that it was composed of two subunits, 43-kDa and 12-kDa. Sequential absorption experiments revealed that: (1) the 12-kDa subunit was antigenically similar to beta 2 microglobulin; (2) the intact molecule did not exhibit HLA-A, B or C "framework" determinants; (3) the molecule was antigenically distinct from a human thymus-leukemia antigen HTA-1 (recognized by monoclonal antibodies NA1/34 and OKT6); and (4) the molecule was antigenically distinct from adenosine deaminase. It is concluded that 513 reacts with a membrane protein (designated 513TL) which exhibits properties characteristic of a histocompatibility-like antigen whose expression is restricted to thymocytes and some leukemias (TL antigen). Its antigenic distinction from another recently characterized human TL antigen, HTA-1, suggests polymorphism among this family of alloantigens.
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PMID:Identification and characterization of a human thymus-leukemia antigen (43-kDa/513TL) bearing a structural relationship to HLA. 633 39

Expression of the enzyme terminal deoxynucleotidyl transferase (TdT) was studied in human thymus during ontogeny and development. In five fetal thymus samples, the enzyme activity was barely detectable. At birth, the terminal transferase activity remained low. Maximum expression of the enzyme activity occurred between 10 and 40 mo of age. Analysis of six other enzyme activities, adenosine kinase, deoxyadenosine kinase, AMP deaminase, dAMP deaminase, 5' nucleotidase, and adenosine deaminase confirmed the normal status of the thymic tissue. A careful analysis of thymic architecture revealed that involution did not occur as a result of the disease process that necessitated cardiac surgery. By immunofluorescence, the TdT antigen was localized exclusively in the nucleus of cortical thymocytes. Protein immunoblotting studies indicated that human thymic terminal transferase exists as a single high m.w. species in individuals under 30 mo of age. Thereafter, a variant m.w. species is detectable. The increase in expression of this enzyme coincides with the increase observed in serum immunoglobulin levels during maturation and precedes the maximum development of the human thymus.
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PMID:Expression of terminal deoxynucleotidyl transferase in human thymus during ontogeny and development. 640 69

In ACI/N rats pretreated with cyclophosphamide (CY) growth of the bladder cancer, BC-47, and adenosine deaminase (ADA) and purine nucleoside phosphorylase (PNP) activities in lymphocytes were investigated to clarify the possible antitumor effect via the immune system of the chemotherapeutic agent. A single dose of 50 mg/kg of CY with the tumor implantation 3 days later gave rise to tumor regression following temporary progression around day 15 and significant increase of peripheral lymphocytes with higher PNP activity on days 7 to 10 of the tumor implantation. In the thymus such lymphocytes increased 3 days earlier. The antitumor effect was not demonstrated in athymic nude mice. In the light of the results and elimination of suppressor T precursors by CY, it was postulated that T lymphocytes with higher PNP activity act as effector cells in the antitumor immunity whereas suppressor T precursors belong to the cell population with lower PNP activity.
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PMID:Host-mediated inhibition of rat bladder cancer growth by cyclophosphamide and purine salvage pathway-related enzyme activity of lymphocytes. 644 29

Pokeweed mitogen-induced B lymphocyte differentiation in vitro into antibody secreting plaque-forming cells (PFC) was investigated in nine patients with severe combined immunodeficiency having variable proportions of circulating B lymphocytes. When cultured by themselves, the peripheral blood mononuclear cells did not respond to stimulation with pokeweed mitogen in any patient. In the presence of irradiated allogeneic T cells as helpers, however, PFC responses were elicited in lymphocyte cultures from peripheral blood and/or bone marrow in some patients. In one of these patients, results of allogeneic co-culture experiments were suggestive of genetically restricted suppressor cells. In a single patient with deficiency of the enzyme adenosine deaminase, PFC were generated in bone marrow lymphocyte cultures only when they were supplemented with exogenous adenosine deaminase and allogeneic helper cells. A parallel study of T lymphocyte differentiation in vitro performed in fractionated bone marrow cells was suggestive of arrested differentiation at different steps along the differentiation pathway. In two patients with evidence of functional B cell precursors, deficiencies of helper T cell function could be attributed to differentiation defects at the level of the stem cells in one and the thymus in the other. The findings reported here further substantiate the heterogeneity of the severe combined immunodeficiency disease syndromes.
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PMID:Heterogeneity of b lymphocyte differentiation in severe combined immunodeficiency disease. 644 66

Deficiency of adenosine deaminase (ADA) in lymphocytes seems to be responsible for severe combined immunodeficiency (SCID), a syndrome in early infancy untreated resulting in death. The highest amounts of ADA activity are found in lymphoid tissues. Considerable enzyme deficiency is associated with an inhibition of proliferation and differentiation, especially of the T lymphocytes, and gives rise primarily to disordered cellular immunity. The molecular mechanisms of the relationship between enzyme deficiency and immune dysfunction are widely unknown. Several possibilities are discussed. Deoxyadenosine and its nucleotides seem to be the toxic agents. The enzyme deficiency is thought to result from a mutation at the structural locus of ADA inherited in an autosomal recessive mode. In addition to transplantation of bone marrow, fetal liver, or thymus the "enzyme replacement" has been suggested for therapy of SCID in ADA deficiency, i.e. transfusion of irradiated erythrocytes with normal ADA activity.
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PMID:[Adenosine deaminase activity and immune dysfunction (author's transl)]. 645 54

Thymic function in myasthenic patients was examined using two biochemical markers which specifically define a population of cortisone-sensitive cortical thymocytes. The enzymatic activities of terminal deoxynucleotidyl transferase (TdT) and adenosine deaminase (ADA) were determined in 13 samples. High contents of both enzymes were found in young patients. The enzymatic activities were easily detectable also in the oldest patients, despite the morphological involution and the decrease in TdT which are known to occur with age in the normal thymus. TdT and ADA-containing cells were almost completely depleted in all the 3 treated patients by the corticosteroid treatment which provides a non-surgical alternative to the elimination of this lymphoid population by thymectomy. The persistence of TdT and ADA activity in old age, and their inhibition by the corticosteroid treatment.
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PMID:Studies on terminal deoxynucleotidyl transferase and adenosine deaminase in myasthenic thymus. 648 Aug 20


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