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)

Bone marrow transplantation is a new concept in the treatment of leukemia and aplastic anemia. The problems seen in the transplanted patient are abundant and often life-threatening. Caring for these patients offers one of the most exciting challenges of nursing. The nurse not only acquires skill in caring for a patient with leukemia and aplastic anemia, but also becomes knowledgeable in infectious diseases, immunology, fluid and electrolyte balance, and cardiac, respiratory, and renal diseases. The complexity of these patients allows the nurse more direct, comsistent contact with them. As she becomes involved, she is given excellent opportunities for supporting the patient and family through this stressful time. Althoug bone marrow transplantation is an experimental procedure with problems still to be solved, results indicate its value in the treatment of refractory leukemia and aplastic anemia.
Nurs Clin North Am 1976 Mar
PMID:Bone marrow transplantation in children. 0 69

Thin-layer radiochromatographic methods for the measurement of histaminase and histidine decarboxylase activities have been developed. The assays are specific for the respective enzymes, are sensitive and reproducible, and can be performed using commercially available substrates. The histaminase assay permits determination of enzyme activity from 2.5 mul of pregnancy sera, 1-2 X 10(6) human granulocytes, and microgram quantities of partially purified human placenta histaminase with an error of less than 5 per cent. The histidine decarboxylase assay permits measurement of nanogram quantities of newly formed histamine from as few as 2 X 10(4) rat peritoneal mast cells or rat basophilic leukemia cells with an error of less than 5 per cent.
J Lab Clin Med 1976 Jun
PMID:Histamine metabolism. I. Thin-layer radiochromatographic assays for histaminase and histidine decarboxylase enzyme activities. 0

A carboxylic-ester hydrolase was isolated from the leukocytes of a patient with myelomonocytic leukemia. Its relative molecular mass as estimated by sucrose density-gradient sedimentation is about 70 000. The purified enzyme is specific for acetyl esters of aromatic alcohols. It is inhibited by fluoride, but insensitive to eserine or p-chloromercuriphenylsulfonate. Hydrolysis of 1-naphthyl acetate was optimal above pH 6.0; of o-nitrophenyl acetate, above 8.0. The common catalytic site for the two types of substrates on the enzyme was confirmed by competitive inhibition data.
Clin Chem 1978 Jul
PMID:Biochemical characterization of an aryl acetic ester hydrolase isolated from human monocytes. 2 83

1 A simple, specific assay for 6-mercaptopurine (6-MP) in human plasma with a sensitivity of 10 ng/ml (66 nmol/1) has been developed. 2 6-MP was extracted directly from plasma into toluene using a novel extraction procedure. This involves conversion of 6-MP into a phenyl mercury derivative by its reaction with phenyl mercuric acetate in alkaline plasma and extracting into toluene. Back-extraction of the toluene layer with 0.1N HCl regenerates 6-MP, which is then oxidised to purine-6-sulphonate and assayed fluorimetrically. 3 This assay has been modified to measure azathioprine and a new thiopurine metabolite in plasma. 4 In a kidney transplant patient given azathioprine, 50 mg i.v., conversion to 6-MP was rapid and the plasma half-life of 6-MP was 36 min. 5 These assays are suitable for studying the pharmacokinetics of azathioprine in patients with kidney transplants. The 6-MP assay should also prove useful for studying the pharmacokinetics of the drug in patients with leukaemia.
Br J Clin Pharmacol 1979 Sep
PMID:Assay of azathioprine, 6-mercaptopurine and a novel thiopurine metabolite in human plasma. 4 May 85

The ultrastructure and adenine nucleotide metabolism of platelets from patients with acute leukemia were studied to elucidate possible mechanisms for the platelet dysfunction observed in this clinical setting. Nonstimulated (resting) platelets from leukemic patients varied greatly in size; exhibited marked variation in the number of alpha granules present per cell; had poorly delineated circumferential bands of microtubules; and often grossly dilated open channel systems or cytoplasmic vacuolization. The intracellular concentrations of ATP and ADP were significantly below normal, and the specific radioactivity of ATP and ADP of nonstimulated platelets in leukemia was equivalent to or exceeded that seen in stimulated normal platelets. Addition of ADP or collagen to platelets from leukemic patients was followed by retarded and incomplete shape change, delayed and incomplete centripetal migration of subcellular organelles, impaired degranulation, and the formation of loose aggregates composed of relatively few platelets. Stimulation of "leukemic" platelets with collagen led to the release of significantly subnormal amounts of ATP and ADP and no significant change in the specific radioactivity of the intracellular nucleotides. In contrast to the results in normal platelets, the conversion of ATP to inosine monophosphate and hypoxanthine in platelets in leukemia failed to increase significantly with collagen stimulation. The results indicate that abnormalities exist in the storage pool of adenine nucleotides and the release mechanism of platelets in acute leukemia. These defects appear to contribute to an impairment in the release reaction in these platelets. Many of the ultrastructural and metabolic defects seen in acute leukemia occur in platelets in preleukemia.
J Clin Invest 1975 Jul
PMID:The platelet defect in leukemia. Platelet ultrastructure, adenine nucleotide metabolism, and the release reaction. 4 18

Inhibition of DNA polymerase from oncorna viruses by a new class of macromolecular inhibitors is reported. The macromolecule, designated as mercaptopolycytidylic acid (MPC), is a chemically modified polycytidylic acid containing 5-SH cytidylic bases in the polymerase. Partially thiolated polycytidylic acids (MPC I-III, containing 1.7%, 3.5%, and 8.6% 5-mercaptocytidylate units, respectively) inhibited the DNA-polymerase of Friend leukemia virus (FVL) in the endogenic reaction as well as in the presence of poly rA-(dT)14 or poly (dA-dT) templates; the inhibitory activities were directly related to the percent of tholation. In a bacterial DNA polymerase (E coli-K12 with denatured calf thymus DNA as template) MPCI-III showed no activity. Biological experiments showed that MPC III inhibits the leukemogenic potential of cell-free spleen extracts from FVL-infected mice to about 60%, measured on the basis of spleen weight. The enzymatic and animal experiments have led us to carry out preliminary clinical trials in some cases of Children leukemia. These cases, resistent to the known therapeutic regimes (combination chemotherapy), responded well when treated with MPC along, or in combination with poly I. The experiments indicate that the development of modified polynucleotids with structural similarities to functional templates may be of potential use in the future chemotherapy of leukemia.
Z Krebsforsch Klin Onkol Cancer Res Clin Oncol 1975
PMID:[Inhibition of viral reverse transcriptase and leukemogenesis by modified nucleic acids (author's transl)]. 4 86

Surface antigenic specificities of human thymus-derived (T) lymphocytes were studied by cytotoxicity tests using a heterologous rabbit anti-human thymus serum. This serum showed higher cytotoxic titres on thymocytes by comparison with peripheral lymphocytes. After proper absorption the antiserum was non-toxic for chronic lymphatic leukaemia cells, but lysed the majority of thymocytes. It also lysed some of peripheral lymphocytes, corresponding to those lymphocytes which bound sheep erythrocytes (E) but not erythrocyte-antibody-complement complexes (EAC). Pretreatment of lymphocytes with the absorbed antiserum and complement completely abrogated rosette formation with E but spared EAC-binding lymphocytes. It also eliminated their reactivity to phytohaemagglutinin and concanavalin A. These findings indicate that the absorbed serum causes selective lysis of T cells. The results obtained from quantitative absorption studies suggest that a certain loss of T-cell antigens is brought about during the differentiation of thymocytes into peripheral T cells.
Clin Exp Immunol 1975 Jan
PMID:Surface antigenic specificities of human thymus-derived lymphocytes. 5 32

Somatic cells of vertebrates contain gene sequences which are an integral part of chromosomal DNA and which code for the production of complete type C RNA viruses. These virogenes are genetically transmitted from parent to progeny along with other cellular genes (virogene-oncogene hypothesis). Activation of this endogenous virogene information from a normally repressed state, rather than infection by exogenous oncogenic viruses, has been proposed as the most common mechanism of cancer causation in animals, including man. Recent isolates of baboon type C RNA viruses, while related morphologically and biochemically to other mammalian type C RNA viruses, can be distinguished by nucleic acid hybridization and immunologic criteria. Within primates, type C virogenes have evolved as the species have evolved; virogenes from closely related genera and families have the closest gene sequence homology. Endogenous viruses from one species may infect animals of a distantly related species and become incorporated into their germ line. Genomes of exogenous viruses, such as the murine leukemia viruses, which are infectious from animal to animal within the same species, evolve more rapidly than the endogenous virogenes which replicate solely as cellular genes. A major viral structural protein of baboon type C RNA viruses, p30 was detected by radioimmunoassay in normal primate tissues. Radioimmunoassays have also detected p30 antigen in human tissues which appear to be immunologically related to primate viral p30. Hybridization experiments have confirmed that type C viral sequences are also present in the human genome.
Ric Clin Lab
PMID:Type C virogenes: genetic transfer and interspecies transfer. 5 81

Specific and nonspecific esterase reactions of bone marrow cells from 14 patients with untreated acute myelomonocytic leukemia and six patients with acute histiomonocytic leukemia were examined. The technic for esterase determination permitted simultaneous visualization of both esterases on the same glass coverslip containing the marrow cells. In cases of acute histiomonocytic leukemia, monocytes, monocytoid hemohistioblasts and undifferentiated blasts stained intensely positive for nonspecific esterase, using alpha-naphthyl acetate as the substrate. No evidence of specific esterase activity using naphthol ASD-chloroacetate as the substrate and fast blue BBN as the dye coupler was apparent in these cells. In all of the cases of acute myelomonocytic leukemia, both specific and nonspecific esterases were visualized within monocytes, monocytoid cells, and granulocytic cells that had monocytoid-type nuclei. Nonspecific esterase activity was not observed in polymorphonuclear leukocytes in cases of myelomonocytic leukemia. The results support a current viewpoint that acute myelomonocytic leukemia may be a variant of acute myeloblastic leukemia, and that cytochemically, many of the leukemic cells in myelomonocytic leukemia share properties of both granulocytes and monocytes.
Am J Clin Pathol 1977 May
PMID:Esterase reactions in acute myelomonocytic leukemia. 6 4

Specific and nonspecific esterases were extracted from various typical cytologic types of leukemic blasts and subjected to electrophoresis in polyacrylamide gel. Preparations rich in normal granulocytes and normal monocytes were analyzed in a similar manner. The results indicated the presence of specific esterase activity in normal monocytes and in myelomonocytic and histiomonocytic leukemia, and a lack of consistent differences in the electrophoretic patterns of both specific and nonspecific esterases in these leukemias. The results support the viewpoint that distinctions between myelomonocytic and histiomonocytic leukemias cannot be made with certainty, and that they may represent variants within a broad spectrum of monocytic leukemias rather than separate and distinct entities.
Am J Clin Pathol 1978 Jan
PMID:Esterases in acute leukemias: a cytochemical and electrophoretic study. 7 7


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