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)

Adult height in 20 patients, successfully treated for childhood leukemia, led to reduced height less than 2 standard deviations (S.D.). The loss in projected final height of 0.8 S.D. was mainly due to intensity of maintenance therapy of protocol LSA2L2 (14). In contrast, less intensive maintenance therapy (6-MP and MTX) of protocol BFM 81 (13) showed a transient growth spurt. Final height equals projected target height. Neither 18-Gy nor gold-198 intrathecally compromised final height.
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PMID:[The effect of different ALL therapeutic protocols on body height and the growth rate]. 235 55

Dihydrofolate reductase from L1210 leukemia cells which are sensitive and resistant to methotrexate has the same physical and kinetic properties and immunoreactivity with a guinea pig antiserum raised to the enzyme purified from the methotrexate resistant strain. However, a chicken antiserum to dihydrofolate reductase from methotrexate sensitive L1210 cells has greater affinity for the homologous enzyme than for the enzyme from the MTX resistant cells indicating that there is some antigenic difference in these molecules.
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PMID:Immunologic heterogeneity of dihydrofolate reductase from methotrexate sensitive and resistant L1210 leukemia cells. 241 35

This paper describes studies that further explore the pharmacologic activity of the 7-hydroxy catabolite of methotrexate (7-OH-MTX). A 3-hr exposure of L1210 leukemia cells to 100 microM 7-OH-MTX produced negligible suppression of cell growth despite the build-up of intracellular polyglutamyl congeners to levels 2.7 times greater than the dihydrofolate reductase (DHFR) binding capacity. There was no evidence for direct inhibition of DHFR under these conditions based upon measurements of cellular tetrahydrofolate cofactor and dihydrofolate levels, nor was there suppression of [3H]deoxyuridine incorporation into DNA or [14C]formate incorporation into purines. When the interval of exposure to 100 microM 7-OH-MTX was increased to 6 hr, cell growth was inhibited by 60% and there was mild (approximately 50%) inhibition of purine and thymidylate biosynthesis associated with a small increase in cellular dihydrofolate and a small decline in cellular tetrahydrofolates. Consistent with weak inhibition of DHFR was the absence of significant binding of 7-OH-MTX polyglutamates to DHFR as assessed by gel filtration of cell extracts. Mild direct inhibition of purine biosynthetics by 7-OH-MTX- or MTX-polyglutamyl congeners was demonstrated based upon inhibition of [14C]formate incorporation into purines in cells pretreated with fluorodeoxyuridine so as to prevent tetrahydrofolate cofactor depletion or dihydrofolate polyglutamate build-up. Effects of a 6-hr exposure of cells to 100 microM 7-OH MTX on cell growth were reversed completely by 10 microM leucovorin; effects on cells containing comparable levels of MTX polyglutamyl congeners were unaffected by leucovorin. These studies demonstrate very weak inhibition of L1210 leukemia cell growth and purine, pyrimidine and tetrahydrofolate synthesis by the polyglutamyl congeners of 7-OH-MTX. The data suggest that effects of 7-OH-MTX polyglutamates on folate-requiring enzymes are not likely to play an important role in moderate-dose MTX regimens. However, pharmacologic activity may be expressed in high-dose MTX protocols when high blood levels of 7-OH-MTX are sustained over long intervals to the extent to which polyglutamate congeners accumulate in tumor cells and add to the much more potent inhibitory effects of MTX polyglutamates already present. Pharmacologic activity, however, would be diminished, if not completely reversed, by the concurrent administration of leucovorin.
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PMID:Further studies on the pharmacologic effects of the 7-hydroxy catabolite of methotrexate in the L1210 murine leukemia cell. 246 76

We previously reported (J. Galivan et al., Proc. Natl. Acad. Sci. USA, 82: 2598-2602, 1985) the synthesis and characterization of DL-erythro,threo-gamma-fluoromethotrexate (FMTX). The individual diastereomers, DL-erythro-FMTX (eFMTX) and DL-threo-FMTX (tFMTX), and their radiolabeled counterparts have now been prepared and characterized. Transport of eFMTX (Km = 9.3 microM; Vmax = 7.5 pmol/min/10(7) cells) was similar to that of methotrexate (MTX: Km = 6.6-9.9 microM; Vmax = 11.4-14.2 pmol/min/10(7) cells), while tFMTX (Km = 65.1 microM; Vmax = 8.4 pmol/min/10(7) cells) was transported less efficiently. Both isomers were able to saturate intracellular dihydrofolate reductase and accumulate further as unbound intracellular drug. Based on competition experiments and studies with MTX transport-defective cell lines, both isomers utilized the reduced folate/MTX transport system. Efflux half-times for the isomers were similar to those of MTX. Each isomer was equivalent to MTX in its ability to inhibit dihydrofolate reductase activity and bind to intracellular dihydrofolate reductase when the intracellular drug concentration was limiting. Both isomers had drastically diminished capacity to be metabolized to poly(gamma-glutamyl) metabolites by isolated folylpolyglutamate synthetase and in whole cells; tFMTX was metabolized to a slightly lesser extent than eFMTX. Using the CCRF-CEM human leukemia and H35 rat hepatoma cell lines, the growth-inhibitory effects of eFMTX were almost the same as those of MTX during continuous exposure, while tFMTX was slightly less potent. This difference in growth-inhibitory potency of the two isomers correlated with their ability to inhibit de novo thymidylate synthesis in the H35 cell line. These results indicate that both diastereomers of FMTX are similar in their properties to MTX, except that both are incapable of being readily converted to polyglutamate derivatives. As a result of these properties, both isomers could be used under appropriate conditions in comparative studies with MTX to define the roles of MTX polyglutamates.
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PMID:Biochemical and growth inhibitory effects of the erythro and threo isomers of gamma-fluoromethotrexate, a methotrexate analogue defective in polyglutamylation. 247 80

Neurological disorders, such as seizures, are not infrequently associated with anti-leukemic therapy. It has been hypothesized that a disrupted peptidergic transmission between neurons could be the cellular basis of the neurological dysfunction. Since endogenous opioids have been recently found to alter neuronal function and possess anticonvulsant properties, the cerebrospinal fluid (CSF) immunoreactive beta-endorphin levels in children with Acute Lymphoblastic Leukemia (ALL) during chemotherapy and cranial irradiation have been studied. Twenty-seven children, 2 at low, 20 at medium and 5 with high risk ALL, undergoing prophylactic treatment for meningeal leukemia, entered the study. Sequential lumbar punctures with introduction of MTX combined with oral prednisone therapy were performed; each lumbar puncture sample was collected and assayed for immunoreactive beta-endorphin. All the patients studied showed a biphasic profile of the peptide with the minimum levels reached during the induction (days 14-28) and the maximum levels detected at the end of the intensification chemotherapy (days 49-55). In the 3 groups the beta-endorphin decrease corresponded to the period of prednisone therapy; the increase was concomitant with the suspension of oral glucocorticoids. 3 patients showed tonic-clonic seizures which coincided with the lowest cerebrospinal fluid beta-endorphin levels and, in the follow-up, 13 out of 27 patients displayed EEG abnormalities. From these findings a relationship between cerebrospinal fluid beta-endorphin concentrations and neuronal excitability in patients with ALL can be suggested. It is also evidenced that oral glucocorticoid therapy has profound inhibitory effects on central beta-endorphin levels.
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PMID:Immunoreactive beta-endorphin levels in cerebrospinal fluid of children with acute lymphoblastic leukemia: relationship with glucocorticoid therapy and neurological complications. 253 Nov 80

A group of 43 pediatric patients with standard-risk ALL were studied. Thirty-seven per cent of them presented with malnutrition at diagnosis. Malnourished children had a significantly worse outcome than well-nourished children. Five-year DFS was 83% for well-nourished children (WNC) and 26% for under-nourished children (UNC) (p less than 0.001). Relapses presented more frequently in the bone marrow in UNC than in WNC (56% vs 7%, p less than 0.0001). The doses of maintenance chemotherapy had to be reduced in 68% of UNC and 11% of WNC (p less than 0.005); the doses of maintenance myelosuppressive chemotherapy (6-MP, oral MTX and hydroxyldaunorubicin) received by UNC were approximately 50% of those received by WNC (p less than 0.01). The correlation between malnutrition and compromised treatment was 0.92. Malnutrition might be included as an adverse prognostic factor in acute lymphoblastic leukaemia (ALL).
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PMID:Leukaemia and nutrition. I: Malnutrition is an adverse prognostic factor in the outcome of treatment of patients with standard-risk acute lymphoblastic leukaemia. 258 44

We report a single center experience of 222 patients (pts) less than 18 years old transplanted from 1973 to 1987. The median age was 11 years (1-18). The donor was a monozygotic twin (9 pts), an HLA-id sibling (193 pts), an HLA-id, parent (9 pts), a mismatched related donor (9 pts) and a matched unrelated donor (1 pt). Ninety-six pts were transplanted for SAA. Conditioning varied with time but the majority (59 pts) received CY 150 mg/kg and 6 Gy TAI. The long term actuarial survival is 66% with a median follow-up of 3 years. The group who received CY 200 mg/kg and MTX had a 33% long term survival (LTS). GVH was the main complication with 40% acute and 37% chronic GVHD. Chronic GVHD tended to improve with time after 2 to 4 years of evolution. Ninety pts were transplanted for leukemia (35 AML, 45 ALL and 11 CGL), 20 pts were in relapse. Pts in CR had a LTS of 40%, in pts in relapse, it was 12%. The main causes of death were: interstitial pneumonitis (30%), relapse (27%), GVH (15%). Thirty-five pts were transplanted for constitutional disease: Fanconi anemia (FA) (26 pts), Dyskeratosis congenita (2 pts), Blackfan-Diamond erythroblastopenia (2 pts), Glanzmann thrombasthenia (1 pt), osteopetrosis (1 pt) and Gaucher's disease (1 pt). In FA, the LTS is 70% with a CY 20 mg/kg, 5 Gy TAI regimen. In all disease categories, we did not find any influence of donor's sex on GVH and survival.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Pediatric bone marrow transplantation for leukemia and aplastic anemia. Report of 222 cases transplanted in a single center. 267 24

The combined effect of cisplatin (CDDP) with various types of antitumor drugs was examined in P 388 leukemia in vivo. Three representative drugs were chosen from every group of alkylating agents, antitumor antibiotics, antimetabolites, and plant originated drugs. According to their dependency on administration schedules, the dose-dependent and time-dependent drugs were administered once, and daily 5 times, respectively, before and after the single administration of CDDP. In addition to these sequential combinations, simultaneous treatment with CDDP was examined for the drugs which were singly administered. The combined effect was assessed by comparing ILS (increase in life span) in a combined group with the sum of ILS's of each of the 2 single-treatment groups. Synergistic effect was observed in the combination of CDDP with all drugs except MMC. Among them CYC, CQ, ACNU, ADR, PEP, ET, VCR, and VDS produced synergistic effect in any treatment schedules, irrespective of the combination sequences. In the cases of the combination with antimetabolites, the combined effect was depended on the treatment sequences; prior treatment of 5-FU, and posterior treatment of Ara-C and MTX to CDDP administration exhibited a synergistic effect, but the combination in reverse sequence remained almost additive.
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PMID:[Combined effect of CDDP with various types of antitumor drugs against P 388 leukemia]. 273 70

In the first part of this study the availability of folinic acid (FA) and its main active circulating metabolite, 5-methyltetrahydrofolate (5-MTHF), were studied in plasma and cerebrospinal fluid (CSF) from normal subjects after i.v. administration of 100 and 250 mg of FA. 5-MTHF rapidly appeared in plasma, the maximum value being reached at the first observation time point (1 h). FA was eliminated in plasma more slowly than 5-MTHF. Between the two doses, there was no evidence of modification in pharmacokinetic parameters (terminal half-life, clearance) for either FA or 5-MTHF in plasma and CSF; 5-MTHF was the only product detectable in CSF. Considering FA plus 5-MTHF together, the AUC (area under the curve) ratios between CSF and plasma were close to 1%. 5-MTHF was cleared very slowly from CSF (t 1/2 = 85 h). This finding suggested possible accumulation of 5-MTHF in CSF during repeated administration of FA combined with medium or high dose MTX. In the second part of the study, dealing with a group of eight children treated by such protocols, an increase in CSF 5-MTHF was detected from cycle to cycle in five (r = 0.91, P less than 0.01) with a maximum at 5 x 10(-8) M. This progressive accumulation of 5-MTHF in CSF may have a negative effect on the local action of MTX and should be taken into account for therapeutic strategies designed for the management of meningeal leukaemia.
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PMID:Evidence for CSF accumulation of 5-methyltetrahydrofolate during repeated courses of methotrexate plus folinic acid rescue. 280 57

The membrane impermeant protein cross-linker 3,3'-dithiobissulfosuccinimidyl propionate (DTSSP) is a well-known inhibitor of human erythrocyte band 3-mediated inorganic anion transport. We observed that DTSSP is also a potent inhibitor of reduced folate/methotrexate transport in human CCRF-CEM leukemia cells. An interaction of DTSSP with the reduced folate/MTX is substantiated by findings that: (a) like MTX transport itself, the concentration of DTSSP required for half-maximal inhibition of [3H]methotrexate transport varied substantially with the anionic composition of the external medium. In a saline buffer and an anion-deficient buffer the I50 values were 7 and 1 microM, respectively; (b) saturation of the carrier with 1-5 microM methotrexate completely protected the transport system from interaction by DTSSP; (c) methotrexate transport activity in DTSSP-treated cells could be restored after cleavage of the disulfide bond in DTSSP under mild reducing conditions; and (d) pretreatment of cells with DTSSP reduced the incorporation of [3H]methotrexate after labeling with an N-hydroxysuccinimide ester of [3H]methotrexate (NHS-MTX), another potent inhibitor of methotrexate transport. Comparison of DTSSP- and NHS-MTX-induced inhibition of methotrexate transport showed that DTSSP inhibition, in contrast to NHS-MTX inhibition, was (a) less potent, (b) dependent on buffer conditions, (c) reversible by reducing agents, and (d) required only a very low molar ratio of methotrexate over DTSSP to afford maximal protection.
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PMID:Interaction of N-hydroxy(sulfo) succinimide active esters with the reduced folate/methotrexate transport system from human leukemic CCRF-CEM cells. 280 8


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