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

To evaluate the potential carcinogenic effects of formaldehyde, we examined the proportionate mortality experience of embalmers licensed to practice in California. Mortality was significantly elevated for total cancer, arteriosclerotic heart disease, and suicide, whereas significant deficits were noted in mortality from diseases of the respiratory and genitourinary systems. Deaths from cancers of the brain, colon, and prostate and leukemia were significantly higher than expected. No increased mortality was seen for cancers of the respiratory tract, including the nasal passages, where an effect might be expected based on animal studies. A parallel mortality survey of embalmers from New York State showed similar findings, with excesses of brain tumors, leukemia, colon cancer, arteriosclerotic heart disease, and cirrhosis. Further investigation is needed to determine whether any of these outcomes is related to formaldehyde exposure.
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PMID:Cancer and other causes of death among embalmers. 646 19

Routine morphologic and cytochemical study of the leukemic cells of a 13-month-old child did not permit definitive determination of either a lymphoid or a myeloid cell origin. However, ultrastructural cytochemical analysis revealed platelet peroxidase (PPO) reactivity. The malignant cells expressed PPO in both unfixed and fixed preparations. PPO was observed in the perinuclear space and reticulum but not in the Golgi saccules. In a 1% glutaraldehyde, 1% formaldehyde solution known to inhibit PPO but not myeloperoxidase, no reaction product was observed. The demonstration of PPO activity in these undifferentiated cells established their megakaryoblastic lineage. Further studies including DNA flow cytometry confirmed that these cells were megakaryoblasts. This study demonstrates that megakaryoblastic malignancy may occur as an acute leukemia of childhood and emphasizes the value of ultrastructural cytochemistry in cases of acute leukemia which defy routine classification. Abnormalities of chromosome 21 were present in our patient as in four previous cases of megakaryoblastic leukemia in childhood. The nonrandomness of chromosome 21 involvement in this disease should therefore be considered.
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PMID:Acute megakaryoblastic leukemia in childhood. 654 Jun 20

Hexamethylmelamine (HMM) and a number of its derivatives are toxic to PC6 plasmacytoma cells in vitro. However, there is no correlation between in vitro cytotoxicity and activity against this tumour in vivo. N-Methylolmelamines are significantly more toxic than HMM itself. These compounds break down to release formaldehyde which is itself a highly cytotoxic agent. Pentamethylmonomethylolmelamine rapidly inhibits the growth of PC6 cells in culture, whereas HMM and pentamethylmelamine (PMM) require prolonged contact with the cells in order to exert a cytotoxic effect. HMM and its metabolites are also toxic to a number of other cell lines. The toxicity of the N-methylols to cultured L1210 leukaemia and Walker 256 ascites cells appears to be due entirely to formaldehyde release, whereas in PC6 cells the methylols appear to be acting more selectively.
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PMID:In vitro cytotoxicity of the methylmelamines. 676 59

The induction of immune resistance to L1210 murine leukemia by 3 types of L1210 vaccines was compared under conditions in which in vitro cell proliferation and transplantability to mice were completely suppressed. L1210 cells treated with glutaraldehyde plus concanavalin A (ConA) were more potent in inducing antitumor immunity than those treated with Vibrio cholerae neuraminidase or mitomycin C (MMC). This and the finding that cell-bound ConA enhanced the immunogenic potency of MMC- or formaldehyde-treated L1210 vaccines indicate that ConA endowed the cells with additional potency in inducing antitumor immunity. ConA-free and ConA-bound vaccine cells took up the same amount of anti-L1210 antibody, suggesting that cell-bound ConA did not increase tumor-associated antigen molecules on the tumor cell surface. However, adoptively transferred spleen cells of mice sensitized with ConA-bound, but not ConA-free, vaccine amplified the vaccine-induced antitumor immunity in the recipients. These donor spleen cells suppressed the in vitro proliferation of live L1210 cells no more than non-primed spleen cells, nor was their amplifying activity abrogated by treatment with anti-Lyt-2.1 antibody and rabbit sera as a source of complement. This indicated that cytotoxic T cells and/or their precursors were not involved in the observed amplification. This as well as the finding that their amplifying activity was completely abrogated by treatment with rabbit anti-mouse brain-associated T cell antigen antisera and rabbit sera as a source of complement, led us to conclude that amplifier T cell production, associated with vaccine-bound ConA, was responsible for the enhanced immunogenic potency of ConA-bound vaccines.
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PMID:Immunogenicity and amplifier cell production by tumor vaccines enhanced by concanavalin A. 681 60

The effect of vinblastine on the distribution of murine leukemia virus-derived membrane-associated antigens was examined by using the indirect immunofluorescence of 3.7% formaldehyde-fixed MJD-54 (Moloney murine leukemia virus-infected) cells. On fixed, non-drug-treated cells, p30 antigen was distributed homogeneously and diffusely over the cell membrane. When cells were incubated with 10 microM vinblastine for 1 hr before fixation, the distribution of p30 antigen was greatly changed, fluorescence now being collected into poles (cap-like formation). In contrast to this distribution pattern for p30 antigen, gp70 antigen was distributed in a micropunctate pattern on the cell surface, with or without vinblastine pretreatment. These observations indicate that the distribution patterns of p30 and gp70 membrane antigens are completely different and that they are differently controlled by cytoplasmic microtubules. In addition, because the p30 membrane antigen visualized in these studies most likely represents viral Pr65gag precursor molecules which are localized directly under and associated with the plasma membrane, these results suggest that, under special conditions of fixation, it is possible to obtain a cap-like phenomenon for cytoplasmic (internal) membrane-oriented proteins.
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PMID:Effect of vinblastine on distribution of murine leukemia virus-derived membrane-associated antigens. 703 45

The cytotoxicity of the antitumour nitrosoureas BCNU and CCNU and the isocyanates which they liberate (chloroethylisocyanate and cyclohexylisocyanate respectively) has been measured utilising an in vitro-in vivo bioassay. Lines of the TLX5 lymphoma and L1210 leukaemia were used which were either sensitive or resistant to nitrosoureas in vivo. An estimated logarithmic cell kill produced by each compound in vitro (before injecting the cells into animals) was calculated by reference to assays of the survival time of animals given from 2 X 10(5) to 2 X 10(0) cells of each line. Resistance to both BCNU and CCNU was observed in vitro in the cell lines of the TLX5 lymphoma made resistant to either BCNU or a dimethyltriazene in vivo. The latter tumour was cross-resistant in vivo to nitrosoureas. Resistance in vitro to nitrosoureas was also observed in a line of L1210 leukaemia which had had resistance to BCNU induced in vivo. The nitrosourea resistant TLX5 lymphomas were cross-resistant in vitro to both cyclohexylisocyanate and chloroethylisocyanate whereas the nitrosourea resistant L1210 line showed no cross-resistance to cyclohexylisocyanate and marginal cross-resistance to chloroethylisocyanate. The results suggest that the TLX5 lymphoma, which is naturally resistant to alkylating agents of the 2-chloroethylamine type, may be sensitive to in vivo to nitrosoureas as a consequence of the intracellular release of isocyanates. This hypothesis was supported by the finding that the resistant TLX5 lymphoma showed no cross-resistance to other electrophilic agents, for example formaldehyde, monomethyltriazene or HN2. The transport of nitrosoureas into the sensitive and resistant cell lines was similar in profile and there was no difference in the concentration of non-protein thiols.
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PMID:The role of isocyanates in the toxicity of antitumour haloalkylnitrosoureas. 713 75

Tartrate-resistant acid phosphatase activity may be demonstrated in paraffin-embedded liver and spleen specimens as well as in decalcified bone marrow biopsies after fixation in a mixed glutaraldehyde-formaldehyde-calcium acetate solution. This technique may routinely be applied to haematologically relevant material and aids in the differential diagnosis of hairy-cell leukaemia.
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PMID:Diagnosis of hairy-cell leukaemia by tartrate-resistant acid phosphatase activity in paraffin-embedded tissue sections. 740 Mar 58

Mortality through 1988 was studied for 5,932 male employees who worked between January 1, 1946 and December 31, 1967 at a New Jersey plastics manufacturing and research and development facility. The cohort was followed for an average of 32 years and included 1,859 deaths. Potential exposures included asbestos, formaldehyde, and polyvinyl chloride (PVC). Mortality rates for the cohort were compared to both U.S. and state mortality rates, and analyses were also performed by lagging duration of employment. Based on U.S. rates, mortality among hourly males (n = 3,853) from all cancers was similar to expected [standardized mortality ratio (SMR), 102; 95% confidence interval (CI), 92-114]. Excess mortality among hourly workers was seen for pancreatic cancer (SMR, 146; 95% CI, 95-216) and "malignancies of other parts of the respiratory system" (SMR, 373; 95% CI, 121-870). The latter excess was due entirely to five deaths from pleural mesothelioma. There were no deaths identified due to nasal cavity or nasopharyngeal cancers, or angiosarcoma of the liver. Mortality from leukemia among research and development workers (n = 1,421) was significantly elevated (SMR, 265; 95% CI, 115-524) and related to assignment to process development. This study verifies the excess of pancreatic cancer among workers at the facility seen in earlier studies and observes excesses of mesothelioma due to asbestos exposure and leukemia in process development workers.
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PMID:Mortality among workers at a plastics manufacturing and research and development facility: 1946-1988. 748 91

Jobs and exposures in woodwork may entail an elevated risk of lymphomas and leukemias. Exposures occurring in woodwork were scrutinized in a small industry-based case-referent study of four cases of Hodgkin's disease, eight cases of non-Hodgkin's lymphoma, 12 cases of leukemia, and 152 matched referents, all from the Finnish wood industry. Past exposures to wood dust, chlorophenols, terpenes, and engine exhaust, individually reconstructed through plant- and period-specific job exposure matrices, were unrelated to lymphoma/leukemia risk. Exposures to various solvents were associated with an odds ratio (OR) of 5.6 (95% confidence interval 1.0-32.0). The OR for formaldehyde was 2.5 (nonsignificant). The results are interpreted as providing limited evidence of the role of exposure to some as yet unidentified organic solvents in increasing the risk of malignant lymphomas. Formaldehyde may be another woodwork-related risk factor for some lymphomas, but the power of the study was too low for empirical confirmation of this possibility. Leukemias did not seem to be associated with any of the exposures studied.
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PMID:Malignant lymphomas and leukemias, and exposures in the wood industry: an industry-based case-referent study. 831 19

Double immunofluorescence studies using both surface and cytoplasmic antigens were performed on cells of some human hematopoietic lines. We tested several permeabilization protocols in order to optimize, improve and simplify flow cytometric assay to detect the combinations of two markers present in one cell which could be regarded as leukemia-related markers. It was found, that buffered formaldehyde-acetone (BFA) fixation renders the cell membrane permeable without destroying surface antigens so that intracellular and cell surface markers could be measured simultaneously by flow cytometry. Cell lines used for the experiments reported here included MOLT4 T cell line, mature B cell lines DAUDI and U-266, and early B cell line REH-6. Results from our studies demonstrated, that in the absence of CD3 antigen on the surface membrane of viable MOLT4 blast cells, double labeling of fixed, permeabilized cells revealed 97% mCD7+, cCD3+ double positive cells. Two color staining with anti-CD19 and anti-CD22 monoclonal antibodies (MoAbs) in DAUDI cells showed, that larger part of cCD22+ cells expressed mCD19 antigen. CD22 antigen was absent on DAUDI cell membrane. Of great interest was the finding, that the marker detected by anti-CD19 MoAb which was absent on the membrane of U-266 cells was detected in their cytoplasm. Double staining of these cells revealed, that the number of mCD22+, cCD19+ double positive cells was 80%. Cytoplasmic CD22 antigen along with surface membrane CD19 was used to define early B cell line REH-6 as well. Our results demonstrate majority of double positive cells among tested population (mCD19+, cCD22+). To our knowledge the presence of cytoplasmic IgM detectable by flow cytometry in REH-6 cells, which could be so regarded as a precise and adequate counterpart to pre-B acute leukemia cell phenotype in children, is an original finding. Immunological typing plays an important part in the multiple marker analysis of hematopoietic malignancies. Through these surface and cytoplasmic marker combinations minor neoplastic cell populations could be detected. Human hematopoietic cell lines could serve as a reliable model system for monitoring minimal residual disease in acute leukemia patients.
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PMID:Human hematopoietic cell lines: a model system for study of minimal residual disease detection technique in acute leukemia. 855


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