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Query: UMLS:C0023418 (leukemia)
 93,477 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Numerical and structural chromosome aberrations are frequently found in neoplastic cells. As demonstrated by the new chromosome banding techniques these aberrations are not random, but tend to show a specific occurrence. A model example is the leukemias where many cytogenetical investigations have been done to date. In leukemia chromosome analysis serves the following purposes: to identify a neoplastic process, to confirm and strengthen the hematological diagnosis, for the early diagnosis of transformation from a chronic leukemia into its blastic phase and for following up the clonal evolution of a leukemic cell line. In the discussion of chromosomes and neoplasms it must be mentioned that individuals demonstrating chromosomal instability and some trisomic patients show a greater tendency toward the development of a malignancy. Malignancy is primarily a cellular phenomenon caused by a disturbance in cellular regulation, whose fine events are not known. Therefore the exact role of the chromosomes in neoplastic processes cannot be stated. From experimental investigations it appears that the affected chromosomes carry cell growth regulating factors and also that a specific aberration is the result of the action of a specific agent.
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PMID:Editorial: Chromosomes and human neoplasms. Achievements using new staining techniques. 6 Feb 37

The purpose of this investigation was to search for oncornavirus in primary cell cultures obtained from leukemic cattle organs and lymphocytes and to study their molecular-biological properties and role in the etiology of cattle leukemia. The investigation was carried out on 25 primary trypsinized cell culutres of lymph nodes, spleens, kidneys and lymphocytes from cattle with acute and chronic leukemia. It was demonstrated that all cell cultures from leukemic cattle (in contrast to cell cultures from healthy cattle) released oncornavirus into the culture medium. The virus possesses the main properties of oncornaviruses: it has a virion of C-type structure with a density of 1.16--1.18g/ml in a 20--60 per cent sucrose gradient, which may be induced by 5-bromodeoxyuridine, inhibited by Actino-mycin D, has reverse transcriptase activity, contains 60S RNA, that is annealed in the reaction of molecular hybridization with DNA of lymph nodes of cattle with leukemia. The propagation of the isolated oncornavirus in continuous cell lines of calf kidney culture was demonstrated. Experimental inoculation of purified oncornavirus was carried out on 60 baby calves and 15 lambs from leukosis free herds or flocks. Several of the calves later showed evidence of virus infection.
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PMID:Isolation and characterisation of oncornavirus from primary cultures of tissues from cattle with leukemia. 6 13

The interaction of peanut agglutinin (PNA) with human thymocytes, peripheral blood lymphocytes, and peripheral blood cells of various types of leukemia was investigated by using fluorescein isothiocyanate-conjugated PNA. The majority of human thymocytes (60-80%) bind the lectin. The major subpopulation of thymocytes that is PNA-positive was separated from the PNA-negative cells by differential agglutination with the lectin. The two thymocyte subpopulations were tested in the mixed lymphocyte reaction and with the phytohemagglutinin of Phaseolus vulgaris. The poor response of the PNA-positive thymocytes to these stimuli indicates that these thymocytes are functionally immature. The fluorescein isothiocyanate-PNA-binding test with peripheral blood lymphocytes of leukemic patients revealed that in most acute leukemias the PNA receptor is exposed on the blastic cells, whereas in most cases of chronic leukemia the peripheral blood lymphocytes are PNA-negative. The validity of PNA as a marker of immature blood cells and its potential clinical application are discussed.
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PMID:Interaction of peanut agglutinin with normal human lymphocytes and with leukemic cells. 31 73

A number of disease states are considered "preleukemic" because they carry a significantly increased risk for the subsequent development of frank leukemia. These include a variety of cytopenias, myeloproliferative disorders, and childhood syndromes. Cytogenetic data suggest that these preleukemic disorders may not be qualitatively different from leukemia but simply represent quantitative differences in the degree of selective growth advantage enjoyed by a proliferating abnormal hemic population. Recent chromosome studies have indicated that a) this proliferation is characteristically clonal in both preleukemia and leukemia, apparently resulting from a heritable change in a marrow stem cell that allows it to escape to some degree from normal growth regulation; b) genetic instability in the clone, with additional genetic change, may often underlie clinical progression from the relative indolence of preleukemia or chronic leukemia to an aggressive stage comparable to acute leukemia; and c) certain specific chromosome segments carry genes important in the acquisition of growth advantage by hematopoietic stem cells, and many of these are common to both preleukemia and leukemia. Expansion of hemic clones may also be influenced significantly by alterations in the growth control mechanisms themselves. For instance, in various preleukemic states, preexisting marrow hypoplasia may permit clones with only minimal selective advantage to reach demonstrable size. Chromosome findings may help to establish the diagnosis and prognosis in preleukemic disorders, but additional long-term data are needed.
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PMID:Preleukemia. Cytogenetic clues in some confusing disorders. 33 94

Daunorubicin reductase activity was estimated in peripheral leukocytes drawn from 23 patients with acute or chronic leukemia. Since the enzyme converts daunorubicin to daunorubicinol, a derivative exposing higher cytotoxic action than daunorubicin, it is important for leukemia treatment to know its leukocyte level. Calculations of reductase levels were based on the presumption that one enzyme unit equals an activity which is producing 1 nanomol daunorubicinol per 1 mg homogenate protein during 30 minutes of incubation. It was found, that blasts of different patients with the same leukemia type displayed different reductase levels, ranging between 11.0 and 74.8 U.
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PMID:Daunorubicin reductase activity in leukemia leukocyte homogenates. 39 88

High titer, monospecific antibodies to human granulocyte myeloperoxidase, cathepsin G, elastase, lysozyme, and lactoferrin were conjugated with fluorescein and rhodamine and used for immunofluorescent staining of mature neutrophils obtained from 25 patients with acute and chronic leukemia. In 11 (44%) of the patients, two populations of mature neutrophils were detected. The abnormal cells were identified by complete deficiency of one or more markers and constituted 10%-100% of the total number of neutrophils. This immunocytochemical approach may permit recognition of mature cells derived from leukemic clones, and serial determinations of the ratio of normal to abnormal cells may be useful in the management of patients with leukemia.
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PMID:Immunocytochemical identification of abnormal polymorphonuclear neutrophils in patients with leukemia. 40 Aug 91

The data reviewed in this paper indicate that immunotherapy is effective in prolonging remission and survival in acute and chronic leukemia. The acute lymphocytic leukemias may or may not respond to immunotherapy and further work is needed in this area. No studies of immunotherapy in chronic lymphocytic leukemia have been done, but this will be an important area for investigation, since there is often profound immunodeficiency in this disease. The malignant lymphomas are another fertile area for this type of research, since they have a high response rate, tumor-associated immunodeficiency, and at least differentiation antigens if not tumor-specific antigens. The scientific basis for the use of immunotherapy in leukemia includes the demonstration of a relationship of rate and duration of remission and survival to immunocompetence, the demonstration of unique tumor-associated antigens on leukemia cells, and the demonstration of immune responses to these antigens which can be boosted by immunization. At the present time, active nonspecific immunotherapy with BCG and MER and active specific immunotherapy have been proved effective in acute myelogenous leukemia. Careful attention should be given to dose, schedule, route, and so forth. Other types of immunotherapy remain to be explored.
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PMID:Immunotherapy of leukemia. 78 12

Specific Activities of DNA-dependent RNA polymerases A and B have been determined in nuclei from leukocytes in acute and chronic leukemia. Enzyme activities, dependent on exogenous DNA template, were determined in homogenates of nuclei from isolated mononuclear cells or from isolated granulocytes. Activities of polymerases A and B have been found significantly elevated in homogenates of nuclei from mononuclear cells in acute myelocytic leukemia, while they were found subnormal in corresponding cell fractions from chronic myelocytic leukemia and chronic lymphatic leukemia. During cytostatic treatment polymerase activities were approaching normal values. The prognostic relevance of these data for the course of human leukemia is discussed.
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PMID:[DNA-dependent RNA polymerases in human leukocytes. II different specific activities of the polymerases A and B in acute and chronic leukemia and their prognostic relevance (author's transl)]. 105 88

Of 25 patients with chronic leukemia, there was clinical evidence of peripheral retinal microaneurysm formation in two of eight patients with chronic lymphocytic leukemia and six of 17 patients with chronic myelogenous leukemia. There was no proliferative retinopathy in any of the 25 patients. An elevated leukocyte count seemed necessary for microaneurysm formation in leukemia, although some patients with elevated counts had no microaneurysms. The prolonged leukocytosis of chronic leukemia can produce peripheral capillary dropout, vascular stagnation, microaneurysm formation, and, rarely, peripheral proliferative retinopathy similar to sickle cell disease.
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PMID:Peripheral retinal microaneurysms in chronic leukemia. 105 77

Occurrence of immune complexes in leukemia has been investigated by the 125I-Clq-binding test. A highly significant serum Clq-binding activity (Clq-BA) was demonstrated in 37% of patients with acute myelocytic leukemia, in 23% of patients with acute lymphocyte leukemia,and in 32% of those in blastic crisis of chronic myelocytic leukemia. Such a high Clq-BA is found only in 13% of cases with chronic leukemia. Incidence of increased serum Clq-BA is significantly higher during the blastic stage of leukemia than in complete remission. There is no correlation between the elevated Clq-BA and infections complicating acute leukemia, or with the chemotherapy given to the patients. The Clq-binding material exhibits properties similar to those of immune complexes.
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PMID:[Circulating immune complexes in human leukemias]. 107 Jan 56


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