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

1.25 (OH)2D3 is a potent inducer of differentiation of leukaemic cells into a monocytic direction. However, therapeutic application is difficult because of the development of hypercalcaemia. We examined a novel vitamin D analogue, MC 903, which is at least 100 times less effective on calcium metabolism in rats than 1.25 (OH)2D3. Using the HL-60 cell line, differentiation was measured with a comprehensive panel of qualitative and quantitative parameters. Development of monocytic cells was shown morphologically, immunophenotypically and functionally by increased capability of reducing NBT (vs cultures without MC 903, p less than 0.0001) and by qualitatively and quantitatively increased non-specific esterase activity. Furthermore, a concomitant decreased activity of myeloperoxidase and lactate dehydrogenase was noticed. In conclusion, MC 903 is a potent inducer of monocytic differentiation, comparable with 1.25 (OH)2D3 and will therefore be an interesting and potential therapeutic agent for studies in human acute leukaemia.
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PMID:Monocytic differentiation induction of HL-60 cells by MC 903, a novel vitamin D analogue. 162 69

Although the majority of mouse strains infected with lactate dehydrogenase-elevating virus (LDV) do not show any particular symptoms, the virus is able to induce acute poliomyelitis in C58 or AKR mice. Murine leukaemia virus (MuLV) has been detected at a high titre in the spinal cord of affected mice. In this study, we have analysed the possible role of MuLV in the induction of neurological disease by LDV. Immunofluorescent staining, autoradiography and an infectivity assay of virus yield have shown that LDV replicated in continuous mouse and rat cell lines that had been infected with an ecotropic MuLV isolated from C58 mice, but did not replicate in cells not infected with MuLV. No significant differences in infection were observed among the various ecotropic MuLVs employed, except for Friend leukaemia virus which rendered the cells susceptible to LDV least efficiently. The infectivity of the neurovirulent strain, LDV-C, to MuLV-infected cells was 50- to 100-fold greater than that of the avirulent strains (LDV-N, -Nu, -R and -P). The infectivity to macrophages was almost the same for virulent and avirulent strains. Adsorption studies using a radiolabelled virus revealed that LDV-C was adsorbed to MuLV-infected cells more efficiently than the avirulent strain, LDV-N. The difference in infectivity to these cells, therefore, may be due in part to the difference in adsorption rate. This may suggest differences in the interaction of the viral proteins with MuLV-infected cells from those with macrophages at the initiation of virus infection. These results may be relevant to the mechanisms of paralytic disease caused by LDV infection in C58 mice.
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PMID:Replication of lactate dehydrogenase-elevating virus in cells infected with murine leukaemia viruses in vitro. 165 56

gamma-Glutamyl hydrolase (also known as conjugase) is a ubiquitous enzyme that has the capacity to cleave folyl- and antifolylpolyglutamates. This study has revealed that the enzyme is secreted by primary cultures of rat hepatocytes and by H35 hepatoma cells. H35 cells have lower cellular levels of gamma-glutamyl hydrolase than do hepatocytes but secrete a greater proportion of gamma-glutamyl hydrolase. More than 99% of the total enzyme from H35 cells accumulated in the medium after 48 h. The cells were shown to remain intact during the secretion period since lactate dehydrogenase, dihydrofolate reductase, and lysosomal hydrolases other than gamma-glutamyl hydrolase were retained within the cell. Using the substrate 4-amino-10-methyl-pteroyldiglutamate (4-NH2-10-CH3-Pte-Glu2), the intracellular and secreted enzyme form(s) from H35 cells were found to have the following properties (a) Km values of 24.3 +/- 3.7 microM and 34.8 +/- 8.6 microM, respectively, and (b) maximal activity at pH 5 to 7 and apparent molecular weights of 120,000 by gel filtration. Both the cellular and secreted enzymes convert 4-NH2-10-CH3-PteGlu4 and pteroylpentaglutamate acid, to the corresponding monoglutamates with little or no appearance of intermediate chain length polyglutamates. This suggests that both act primarily as endopeptidases. Thus far, the cellular and secreted enzymes cannot be differentiated although the current studies do not establish this point unequivocally. Alterations in the cellular and secreted H35 cell gamma-glutamyl hydrolase levels in response to changes in culture conditions revealed that glutamine enhances activity while insulin diminishes it. Other transformed cells found to secrete this protein are Hep-G2 human hepatoma, JAR human choriocarcinoma, HeLa, and rat glioma. gamma-Glutamyl hydrolase could not be detected in medium conditioned by human MCF-7 breast cancer cells, and relatively low activities were found in the medium from CCRF-CEM or K562 leukemia cells. These studies directly establish for the first time the secretion of gamma-glutamyl hydrolase in vitro.
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PMID:Secretion of gamma-glutamyl hydrolase in vitro. 171 22

The following diagnostic criteria are proposed to classify four clinical subtypes of HTLV-1 associated adult T-cell leukaemia-lymphoma (ATL): (1) Smouldering type, 5% or more abnormal lymphocytes of T-cell nature in PB, normal lymphocyte level (less than 4 x 10(9)/l), no hypercalcaemia (corrected calcium level less than 2.74 mmol/l), lactate dehydrogenase (LDH) value of up to 1.5 x the normal upper limit, no lymphadenopathy, no involvement of liver, spleen, central nervous system (CNS), bone and gastrointestinal tract, and neither ascites nor pleural effusion. Skin and pulmonary lesion(s) may be present. In case of less than 5% abnormal T-lymphocytes in PB, at least one of histologically-proven skin and pulmonary lesions should be present. (2) Chronic type, absolute lymphocytosis (4 x 10(9)/l or more) with T-lymphocytosis more than 3.5 x 10(9)/l, LDH value up to twice the normal upper limit, no hypercalcaemia, no involvement of CNS, bone and gastrointestinal tract, and neither ascites nor pleural effusion. Lymphadenopathy and involvement of liver, spleen, skin, and lung may be present, and 5% or more abnormal T-lymphocytes are seen in PB in most cases . (3) Lymphoma type, no lymphocytosis, 1% or less abnormal T-lymphocytes, and histologically-proven lymphadenopathy with or without extranodal lesions. (4) Acute type, remaining ATL patients who have usually leukaemic manifestation and tumour lesions, but are not classified as any of the three other types. A total of 818 ATL patients with a mean age of 57 years, newly diagnosed from 1983 to 1987, were analysed by this criteria. There were 448 males and 370 females, and 253 were still alive with a median follow-up time of 13.3 months from diagnosis, while 565 were dead with a median survival time (MST) of 5.4 months. MST was 6.2 months for acute type, 10.2 months for lymphoma type, 24.3 months for chronic type, and not yet reached for smouldering type. Projected 2- and 4-year survival rates were 16.7% and 5.0% for acute type, 21.3% and 5.7% for lymphoma type, 52.4% and 26.9% for chronic type, 77.7% and 62.8% for smouldering type, respectively. Distinct clinical features and laboratory findings of each clinical subtype are described.
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PMID:Diagnostic criteria and classification of clinical subtypes of adult T-cell leukaemia-lymphoma. A report from the Lymphoma Study Group (1984-87). 175 70

Twenty-four healthy cats underwent bronchoscopy and bronchoalveolar lavage to determine the normal cytologic environment of the lower respiratory tract of cats. Initial screening to ensure the health of the study population included complete histories, physical examinations, thoracic radiography, CBC, serologic tests for feline leukemia virus, feline immunodeficiency virus, and occult heartworm, and sugar and Baermann fecal flotation. In 18 cats, protected catheter brush samples of airway secretions from the lavaged lung segment were taken for culture of aerobic and anaerobic bacteria and mycoplasma. Bronchial lavage fluid (5 sequential 10-ml aliquots of normal saline solution) was pooled and filtered with cotton gauze. The unspun sample was used for determination of a total nucleated cell count. Lavage fluid was cytocentrifuged and 500 cells/slide were scored for determination of the cellular differential. Activity of lactate dehydrogenase and concentrations of total protein and IgG within the supernatant were measured, and assays were performed to detect the presence of IgA and IgM. Complete histologic evaluation of the lavaged lung of each of 6 random-source cats was performed after differential cell counting revealed 18% eosinophils within bronchoalveolar lavage fluid recovered from this group. Alveolar macrophages were the predominant cells encountered; however, a quarter of all cells recovered were eosinophils. A significant relationship was not found between the abundance of eosinophils in the lavage fluid, and either isolation of aerobic bacteria, high total nucleated cell counts, total protein concentrations, or activity of lactate dehydrogenase. Histologic evaluation of the lungs of 5 of 6 random-source cats revealed normal lungs in 2 cats, and minimal abnormal change in 3 others. Evaluation of the lungs from 1 random source cat revealed acute, mild eosinophilic bronchiolitis. We conclude that large numbers of eosinophils may be retrieved from the bronchoalveolar lavage fluid of healthy cats.
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PMID:Cytologic, microbiologic, and biochemical analysis of bronchoalveolar lavage fluid obtained from 24 healthy cats. 192 12

Thirty-seven patients with adult T-cell leukemia had serum beta 2-microglobulin (beta 2M) estimated at presentation. A significant association was found between beta 2M and the subtypes of the disease: beta 2M in the acute type is significantly higher than in the chronic and smoldering types (p less than 0.01), and beta 2M in the lymphoma type is apparently higher than in the chronic and smoldering types, although the difference between the lymphoma and chronic types was not statistically significant. An apparent reduction in beta 2M levels after chemotherapy was observed in 7 patients who reached partial or complete remission. One patient who was resistant to chemotherapy showed elevated beta 2M values even after intensive chemotherapy. In another patient, who attained partial remission with a concordant reduction in beta 2M, renewed elevation of beta 2M was observed in parallel with exacerbation of other parameters such as lactate dehydrogenase (LDH), WBC, calcium and clinical manifestations. Correlation analysis was carried out between beta 2M, LDH, calcium, lymphoid cell count and the grade of clinical severity. The beta 2M level was moderately correlated with LDH, calcium, the grade of clinical severity but not with the lymphoid cell count. The clinical severity also correlated with LDH and calcium but to a lesser extent than with beta 2M. These data support the use of the beta 2M in the evaluation of adult T-cell leukemia.
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PMID:Serum beta 2-microglobulin in patients with adult T-cell leukemia. 195 Mar 59

Clinical and biological features were assessed in 114 consecutive previously untreated adult acute myeloid leukaemia (AML) patients whose diagnosis was based on FAB criteria and detailed immunophenotyping. All patients received standard intensive chemotherapy. The main purpose of this study was to establish the prognostic value, if any, of terminal transferase (TdT) expression in myeloid leukaemia. TdT positive cells (7-80% of total blast cells) were detected in 40% of the cases. Among clinical characteristics, a low lactate dehydrogenase (LDH) (less than 250 I.U.) (P = 0.003), a low initial white blood cell count (less than 10 x 10(9)/l) (P = 0.002), and an absolute neutrophil count (less than 5 x 10(9)/l) (P = 0.02) were associated with TdT-positivity. FAB classification was not predictive of TdT expression, and there was no difference in the distribution of FAB subtypes between the groups. Multivariate analysis combining clinical and laboratory data indicated that a low expression of the monocytic antigen CD14 was predictive of TdT positivity in AML (P = 0.01). Karyotyping showed no difference in the pattern of occurrence of specific abnormalities between the TdT+ and the TdT- group. When clinical and immunophenotype data were included in a prognostic model, the patient's age was highly predictive of response (P less than 0.001), and only the CDw65 antigen contributed to the response model (P = 0.07). TdT+ patients with a low expression of CD11b achieved a higher frequency of response at a borderline level of significance (P = 0.06). Frequency of response to chemotherapy, the response duration or overall survival were not influenced by TdT expression.
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PMID:Terminal transferase expression in acute myeloid leukaemia: biology and prognosis. 204 81

A total of 161 cases of pediatric de novo acute myeloblastic leukemia (AML) have been reviewed, for which complete karyotyping was available and three cases (2%) were identified with t(10;11)(p14;q21). Two of the three children were infants with monoblastic (FAB M5) leukemia and the third was an adolescent with undifferentiated myeloid (FAB M1) leukemia. Both infants presented with increased levels of lactate dehydrogenase. None of these cases had increased eosinophils. One of the infants is in remission 18+ months after diagnosis and intensive chemotherapy; the two other children attained brief initial remissions but succumbed to their disease within 11 months of diagnosis. The prognosis of such children appears to be similar to that of cases of AML lacking this translocation.
Leukemia 1991 Jul
PMID:The t(10;11)(p14;q21) translocation in three children with acute myeloblastic leukemia. 207 41

Merocyanine 540 (MC 540) is a photosensitizing dye that is used clinically for the purging of autologous bone marrow grafts and preclinically for the inactivation of enveloped viruses in blood products. Its mechanism of action is not yet well understood. This paper investigates the sites of MC 540-mediated photodamages in L1210 leukemia cells by examining the effects of MC 540-sensitized photoirradiation on several soluble and membrane-bound marker enzymes. When exposed to MC 540 and white light under a standard set of conditions, the activities of Na+/K(+)-ATPase, Mg2(+)-ATPase, and 5'-nucleotidase (three plasma membrane-bound enzymes) were reduced by 54, 49, and 55%, respectively. None of the intracellular enzymes included in this survey was affected by MC 540-sensitized photoirradiation as long as the plasma membrane remained intact. The two soluble enzymes, lactate dehydrogenase and malate dehydrogenase, remained refractory to MC 540-sensitized photoirradiation even after the plasma membrane had been disrupted. By contrast, the activities of the membrane-bound enzymes, NADPH-cytochrome c reductase and succinate dehydrogenase, were reduced in cell lysates by 55 and 81%, respectively. Purified NADPH-cytochrome c reductase was about 3 times less sensitive than the microsomal enzyme, suggesting that the membrane environment facilitated photoinactivation. The MC 540-sensitized photoinactivation of enzymes was accelerated in the presence of deuterium oxide and inhibited if oxygen in the medium was displaced by nitrogen or azide was added to the medium. Taken together, these data support the view that the plasma membrane is a major target of MC 540-mediated photodamages, that the inactivation of membrane-bound enzymes is an oxidative process, and that at least some photodynamic damages are mediated by type II chemistry.
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PMID:Merocyanine 540-sensitized photoinactivation of soluble and membrane-bound enzymes in L1210 leukemia cells. 217 31

Fifty-three Japanese patients with the lymphoma-type adult T-cell leukemia (ATL) were analyzed to study the prognostic value of various clinical findings recorded at the time of diagnosis. All patients were positive for human T-cell leukemia virus type I (HTLV-I) antibody and demonstrated monoclonal integration of HTLV-I proviral DNA in their malignant cells. The important individual variables detected in a previous univariate analysis were placed in a multiple regression model to identify the major prognostic factors for survival. This analysis showed that serum lactate dehydrogenase (LDH), calcium, and total protein levels had a strong predictive relationship with the length of survival (in descending order of importance). Among the 53 patients, 46 were dead at the time of analysis. The cause of death in relation to the duration of survival is also reviewed in this article.
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PMID:Major prognostic factors of Japanese patients with lymphoma-type adult T-cell leukemia. 223 17


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