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J J Hutton

Publications and source records attributed to J J Hutton.

At least 55 records · Page 3Linked to original sources
PubMed1982

Prognostic significance of terminal transferase activity in childhood acute lymphoblastic leukemia: a prospective analysis of 164 patients.

Whether the level of terminal deoxynucleotidyl transferase (TdT) activity in mononuclear cells from bone marrow and peripheral blood has prognostic significance has been analyzed prospectively in 164 children with T and non-T, non-B marked acute lymphoblastic leukemia (ALL). TdT was measured at diagnosis to assess its value as a predictor of duration of remission and length of survival. It was measured repeatedly during remission to assess whether it could predict relapse. Ninety-seven percent of the children achieved a complete remission of their disease, and 40% relapsed during the study. The level of TdT activity in blasts at diagnosis varied 1000-fold from patient to patient. There was no statistically significant relationship between TdT activity in cells at diagnosis and the achievement of complete remission, the duration of remission, or length of survival. TdT activity was significantly increased in the bone marrow of 65% of patients at the time of marrow morphological relapse, but was rarely increased in marrow from patients with isolated testicular or central nervous system relapse. Wide fluctuations in TdT activity were characteristically seen in mononuclear cells from the marrow and peripheral blood of patients with ALL at all stages of their disease. An isolated high value of TdT activity in the bone marrow or peripheral blood cannot be taken as evidence of impending relapse. Quantitative measurements of TdT activity alone on mononuclear cells from bone marrow and peripheral blood are helpful in differential diagnosis, but cannot guide therapy of children with ALL.

Adolescent↗
PubMed1981

Purification, characterization and radioimmunoassay of adenosine deaminase from human leukaemic granulocytes.

Adenosine deaminase was purified 3038-fold to apparent homogeneity from human leukaemic granulocytes by adenosine affinity chromatography. The purified enzyme has a specific activity of 486 mumol/min per mg of protein at 35 degrees C. It exhibits a single band when subjected to sodium dodecyl sulphate/polyacrylamide-gel electrophoresis, non-denaturing polyacrylamide-gel electrophoresis and isoelectric focusing. The pI is 4.4. The enzyme is a monomeric protein of molecular weight 44000. Both electrophoretic behaviour and molecular weight differ from those of the low-molecular-weight adenosine deaminase purified from human erythrocytes. Its amino acid composition is reported. Tests with periodic acid-Schiff reagent for associated carbohydrate are negative. Of the large group of physiological compounds tested as potential effectors, none has a significant effect. The enzyme is specific for adenosine and deoxyadenosine, with Km values of 48 microM and 34 microM respectively. There are no significant differences in enzyme function on the two substrates. erythro-9-(2-Hydroxy non-3-yl) adenine is a competitive inhibitor, with Ki 15 nM. Deoxycoformycin inhibits deamination of both adenosine and deoxyadenosine, with an apparent Ki of 60-90 pM. A specific antibody was developed against the purified enzyme, and a sensitive radioimmunoassay for adenosine deaminase protein is described.

Adenosine Deaminase↗
PubMed1981

Genetic regulation of aryl hydrocarbon hydroxylase activity in cultures of mouse fetal liver cells.

Primary cultures of fetal liver cells were established from six inbred strains of mice to determine whether the genes regulating the induction of aryl hydrocarbon hydroxylase (AHH) in adult livers in vivo also function in fetal liver cells maintained in culture. Fetuses were 19 days old and were derived from three inbred mouse strains (A/J, C3H/HeJ, C57BL/6J) which are classified genetically as aromatic hydrocarbon responsive and three strains (AKR/J, DBA/2J, SWR/J) which are classified as aromatic hydrocarbon non-responsive. Cells were induced with 3-methylcholanthrene (3-MC) and harvested for measurement of AHH activity, DNA content and amount of [3H]thymidine incorporated. The time course of induction of AHH activity by 3-MC was followed from around 60 h after cells were plated until 190 h when cells were at the end of exponential and at the start of stationary growth phase. Both basal and induced AHH activities generally rise to a peak value during exponential growth and then decline as cells reach stationary phase. During late exponential growth to early stationary growth phase, cells derived from responsive strains have higher induced enzyme activity than cells derived from non-responsive strains. Cells from aromatic hydrocarbon responsive mice attained maximal AHH activity with inducer concentrations of 0.05--0.10 micrograms 3-MC/ml. Cells from aromatic hydrocarbon non-responsive strains were maximally induced at 0.50 micrograms 3-MC/ml. The 5--10-fold difference between cells from responsive and non-responsive mice in concentration of 3-MC needed to induce AHH maximally is taken to indicate that genes controlling aromatic hydrocarbon responsiveness in adult mouse livers in vivo also function in fetal mouse liver cells maintained in culture.

Animals↗
PubMed1981

Unusual immunofluorescence patterns for terminal deoxynucleotidyl transferase in blast crisis chronic myelogenous leukemia.

An unusual cytoplasmic distribution of terminal deoxynucleotidyl transferase (TdT) antigen in leukemic cells from two patients who had chronic myelogenous leukemia in blastic phase is described. In most leukemic cells that contain TdT, the intracellular location has been reported to be exclusively nuclear. The cells from these two patients demonstrated TdT staining in both the nucleus and the cytoplasm. The pattern is remarkably similar to that observed in thymocytes, in which bright cytoplasmic staining may also be seen. In the immunofluorescence procedures for detection of TdT in blasts from patients who have chronic myelogenous leukemia, significant cytoplasmic staining should not be mistaken for nonspecific absorption of immunoglobulins or specimen deterioration.

Adult↗
PubMed1981

Biochemical and immunological properties of human terminal deoxynucleotidyl transferase purified from blasts of acute lymphoblastic and chronic myelogenous leukemia.

Terminal deoxynucleotidyl transferase was purified to homogeneity from the blasts of eight patients with leukemia and compared with purified transferase from normal human and calf thymus. In two cases phenylmethanesulfonylfluoride was added during purification to reduce proteolysis. Comparative kinetic analyses of the purified enzymes indicated no differences in catalytic properties. There was substantial variation in the molecular structure of terminal transferase on denaturing polyacrylamide gels: (a) a protein that migrated as a single polypeptide with M(r) = 62,000 was isolated from two patients with acute lymphoblastic leukemia and from MOLT-4 cells; (b) a protein that migrated as a single polypeptide with M(r) = 42,500 was isolated from two patients with acute lymphoblastic leukemia; (c) a protein that migrated as a single polypeptide with M(r) = 42,500 was isolated from two patients with chronic myelogenous leukemia in blast crisis; (d) a protein that migrated as two non-identical subunits of M(r) = 27,000 and 10,000, respectively, was isolated from two additional patients with chronic myelogenous leukemia in blast crisis. The subunit structure of d is characteristic of the homogeneous enzymes purified from human and calf thymus. Neutralizing and precipitating antibodies to terminal transferase from human lymphoblasts and calf thymus have been produced in rabbits and goats. Antisera directed against either human or calf antigens neutralize enzymatic activity and precipitate all forms of human terminal transferase. The multiple human forms give reactions of antigenic identity by immunodiffusion, but differ antigenically from the calf enzyme. The multiple forms of terminal transferase could represent physiological processing, artifactual degradation, or isozymes coded by several genes.

Animals↗
PubMed1981

Biochemical and functional abnormalities in lymphocytes from an adenosine deaminase-deficient patient during enzyme replacement therapy.

Biochemical and immunological properties of lymphocytes were measured repetitively over a period of 40 mo during enzyme replacement by transfusion in a child with adenosine deaminase (ADA) deficiency and severe combined immunodeficiency disease. Catalytically defective ADA protein is present in the child's cells. ADA activity in his lymphocytes is 7 nmol/min per 10(8) cells with 51 ng of ADA protein/10(8) cells by radioimmunoassay. ADA activities in normal cord and adult lymphocytes average 193 and 92 nmol/min per 10(8) cells, respectively, with 429 and 223 ng of ADA protein/10(8) cells. Deoxy(d)ATP accumulates in the patient's erythrocytes and lymphocytes. Transfusion of irradiated packed erythrocytes partially corrects the metabolic defects. Frank metabolic relapse occurs if transfusions are discontinued for several months. The amounts of dATP in erythrocytes and lymphocytes averaged 13 and 2 times normal, respectively, during periods when transfusions were administered every 2-4 wk. Deoxyguanosine triphosphate and deoxycytidine triphosphate in lymphocytes were normal on 11 occasions, but deoxyribosylthymine triphosphate was ninefold increased. On 11 occasions dATP was measured in lymphocytes and erythrocytes isolated simultaneously. There was a positive, but statistically insignificant, correlation between amounts of dATP in the two types of cells (r = 0.25,P > 0.1). The absolute peripheral lymphocyte count was correlated with the activity of ADA in circulating erythrocytes and with the response of lymphocytes to phytohemagglutinin (r = 0.64, P < 0.01; r = 0.49, P < 0.05). Response of lymphocytes to stimulation by phytohemagglutinin in vitro and absolute peripheral lymphocyte counts were not significantly correlated with levels of dATP in the erythrocyte or lymphocyte during periods of intensive therapy. Although there was objective improvement during enzyme replacement, the child remained immunodeficient and biochemically abnormal.

Adenosine Deaminase↗
PubMed1981

The biochemical and clinical consequences of 2'-deoxycoformycin in refractory lymphoproliferative malignancy.

A deficiency of adenosine deaminase, an enzyme important in purine nucleoside catabolism, is associated with a severe combined immunodeficiency disease in children. Inhibition of this enzyme in vitro and in vivo results in an impairment in lymphoblast proliferation. We have investigated the pharmacologic inhibition of this enzyme by 2'-deoxycoformycin in 15 patients with hematologic malignancies. Biochemical consequences of the administration of this agent were closely monitored in erythrocytes, nucleated peripheral blood and bone marrow cells, serum, and urine. A marked rise in erythrocyte dATP was accompanied by a depletion of ATP in those patients exhibiting toxicity. Most patients excreted large amounts of deoxyadenosine but not adenosine in the urine. Serum deoxyadenosine rose in patients demonstrating a marked decrease in cell mass. The biochemical disturbances and clinical toxicity, including hepatic, renal, and conjunctival abnormalities, were usually reversible. Central nervous system toxicity, which potentially was the most serious consequence, was associated with high erythrocyte dATP/ATP ratios and high levels of cerebrospinal fluid deoxyadenosine. In patients with lymphoma and leukemia, objective responses were observed but were short-lived. Patients with chronic lymphocytic leukemia receiving weekly low doses of the drug demonstrated minimal toxicity and some efficacy. The chemotherapeutic potential o 2'-deoxycoformycin, as either a single agent or in combination with Ara-A, merits further exploration.

Adenosine Deaminase↗
PubMed1980

Characterization of purine nucleoside phosphorylase from human granulocytes and its metabolism of deoxyribonucleosides.

Purine nucleoside phosphorylase (EC 2.4.2.1) has been purified 715-fold from human granulocytes by formycin B affinity chromatography. The purified enzyme has a subunit molecular weight of 32,800 +/- 1,300 and an estimated native molecular weight of 102,000, which indicates a trimeric subunit structure. The purified enzyme migrates as a single band upon denaturing and nondenaturing polyacrylamide gel electrophoresis. Its amino acid composition has been determined. Isoelectric focusing of the purified enzyme produces three protein bands with isoelectric pH values of 5.8 to 6.1. The purified enzyme catalyzes the phosphorolysis of inosine, deoxyinosine, guanosine, and deoxyguanosine with apparent Km values of 0.21 mM, 0.32 mM, 0.21 mM, and 0.24 mM, respectively. The ribonucleosides and deoxyribonucleosides of adenine and the pyrimidines are not substrates. There are no major differences in metabolism of ribonucleosides and deoxyribonucleosides. Purine nucleoside phosphorylase activity is inhibited by formycin B in a competitive manner and by adenine in a mixed noncompetitive manner. Antiserum to the purified protein has been prepared and is useful in the immunochemical assay of phosphorylase over the range 10 to 100 ng of protein.

Amino Acids↗
PubMed1980

ATP depletion as a consequence of adenosine deaminase inhibition in man.

Hereditary deficiency of the enzyme adenosie deaminase (adenosine aminohydrolase, EC 3.5.4.4) results in an immunodeficiency syndrome characterized by a marked reduction in circulating lymphocytes. We have administered 2'-deoxycoformycin, a potent inhibitor of adenosine deaminase, to a patient with a lymphoproliferative malignancy. The clinical consequences of pharmacologic inhibition of adenosine deaminase activity included an abrupt decrease in the lymphocyte count, abnormalities of renal and hepatic function, and hemolytic anemia. The plasma concentrations of adenosine and deoxyadenosine rose to peak values of 13 microM and 5 microM, respectively, and erythrocyte dATP levels increased to 110 pmol/10(6) cells over 9 days. There was a corresponding decrease in erythrocyte ATP levels from 128 to < 6 pmol/10(6) cells. A similar profound reductin in ATP occurred in the erythrocytes of a second patient. The rapid and unexpected depletion of ATP associated with dATP accumulation may account, at least in part, for the toxicity associated with 2'-deoxycoformycin administration. The inverse relationship of ATP and dATP raises major questions about the control of energy metabolism in erythrocytes.

Adenosine↗
PubMed1979

Mutagenicity and metabolism of dimethylnitrosamine and benzo[alpha]pyrene in tissue homogenates from inbred Syrian hamsters treated with phenobarbital, 3-methylcholanthrene or polychlorinated biphenyls.

There are significant differences between mice and hamsters in polycyclic hydrocarbon and nitrosamine metabolism. Homogenates of liver, lung and intestinal mucosa from 6 strains of Syrian golden hamster were compared for their ability to metabolize benzo[alpha]pyrene (BP) and dimethylnitrosamine (DMN) to mutagens. Females of strains MHA/SSLak, LSH/SlLak, CB/SsLak, PD4/Lak LHC/Lak and Lak:LVG (SYR) were either untreated or received phenobarbital (PB), 3-methylcholanthrene (MC) or polychlorinated biphenyls (AR) to induce drug-metabolizing enzymes. Salmonella typhimurium TA92 and TA98 were used as indicators of the formation of mutagans. Dimethylnitrosamine demethylase (DMND) was assayed using 1 mM DMN as substrate. Aryl hydrocarbon hydroxylase (AHH) was measured using benzo[alpha]pyrene as substrate. MC does not induced AHH activity in hamster liver, but is an excellent inducer of enzymes converting BP to mutagens. This lack of correlation between increased AHH activity and increased metabolism of BP to mutagen in liver is in marked contrast to correlations seen in mice. MC induces AHH in hamster lung and intestinal mucosa. AR induces AHH in liver, lung and intestinal mucosa. Activity of DMND in liver is not affected by treatment of hamsters with BP or AR, but is repressed approx. 30% by treatment with MC. Activity of DMND and conversion of DMN to mutagen are correlated (r = 0.59) in hamster liver. Microsomes of hamster liver are more effective than those from mouse in converting DMN to mutagen, despite similar DMND activities in livers from the two species.

Animals↗
PubMed1979

Comparison of the in vitro mutagenicity and metabolism of dimethylnitrosamine and benzo[a]pyrene in tissues from inbred mice treated with phenobarbital, 3-methylcholanthrene or polychlorinated biphenyls.

Homogenates of liver, lung, kidney, stomach, small intestine and colon from 8 strains of mice were compared for their ability to metabolize benzo[a]pyrene (BP) and dimethylnitrosamine (DMN) to mutagens. Females of strains CF1, AKR/J, AU/SsJ, DBA/2J, SWR/J, A/J, C3H/HeJ, and C57BL/6J were either untreated or received phenobarbital (PB), 3-methylcholanthrene (MC) or polychlorinated biphenyls (AR) to induce drug-metabolizing enzymes. The effects of these drugs on organ weight and on the amounts of DNA, S-10 protein, and microsomal protein per unit weight of tissue are reported. Salmonella typhimurium TA92 and TA98 were used as indicators of the formation of mutagens. For each organ there was an optimal balance between amount of tissue homogenate and concentration of test compound for maximal yield of revertants. A sensitive radiometric assay of DMN demethylase (DMND) is described which permits measurement of the enzyme in liver, lung and kidney. DMN at 1 mM is used as substrate. Aryl hydrocarbon hydroxylase (AHH) was measured in all tissue using BP as substrate. AR and MC are very good inducers of AHH activity in livers of mice classified as aromatic hydrocarbon responsive, but not in those classified as hydrocarbon nonresponsive. Responsiveness is strain-specific and genetically regulated. Metabolism of BP to mutagens by liver homogenates was correlated with extent of AHH induction. This dimorphism of response of AHH to inducers was present, but less pronounced, in non-hepatic tissues. Basal activities of AHH and DMND were correlated in livers and lungs from untreated mice. DMND activities were increased less than 2-fold by PB, MC or AR treatments. Metabolism of DMN to mutagens was not closely correlated with DMND activities. Strain of mouse, type of tissue and test substance are important variables in assessing the potential effect of microsomal enzyme-inducing agents on the metabolism of mutagenic substances.

Animals↗
PubMed1978

Overproduction of adenine deoxynucleosides and deoxynucletides in adenosine deaminase deficiency with severe combined immunodeficiency disease.

The deoxynucleotide, dATP, is elevated 50- to 1,000-fold above normal in erythrocytes, lymphocytes, and bone marrow from a child with adenosine deaminase deficiency and severe combined immunodeficiency disease. The child, when 17 mo of age, was also excreting approximately 30 mg of deoxyadenosine per day in urine (normal is less than 0.1 mg/day). Urinary excretion of uric acid was decreased. Elevated dATP levels in lymphocytes and bone marrow, and increased urinary excretion of deoxyadenosine, persisted despite hypertransfusion of the child with irradiated erythrocytes from a donor with normal adenosine deaminase. Overproduction of deoxynucleotides by increased salvage of adenosine appears to be the primary metabolic abnormality in patients with adenosine de aminase deficiency.

Adenosine↗