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)

The increasing insights into the pharmacokinetics and the metabolism of cytosine arabinoside (AraC) have improved the rationale for its application in leukemia therapy and have led to a pharmacologically directed design of antileukemic treatment. The current study aims at adding to this approach by detecting differences in the intracellular metabolism of AraC 5'-triphosphate (AraCTP) between leukemic and normal mononuclear blood cells. Measurements of intracellular AraCTP levels were complemented by determinations of plasma AraC and AraU concentrations and were performed in 32 patients with acute myeloid leukemia undergoing combination therapy including either conventional (100 mg/m2 daily) or high-dose (1.0 or 3.0 g/m2 twice daily) AraC. Plasma AraC concentration showed a linear relationship to the applied AraC dose but did not correlate with intracellular AraCTP levels. During conventional-dose AraC therapy little interpatient variation was observed in AraCTP retention times in leukemic blasts from 5 patients with t1/2 values ranging from 1.70 to 2.50 h (median 2.14 h). In all cases AraCTP levels declined rapidly after the end of the AraC infusion. Substantial differences in AraCTP retention times were revealed, however, during 3 h infusions of either 1.0 or 3.0 g/m2 AraC in leukemic blasts from 10 patients with t1/2 values between 1.60 to 7.63 h (median 2.42 h). In addition, AraCTP levels declined in only one patient by > 10% within the first hour after the end of therapy and remained constant or even increased up to 1.5-fold in a post-treatment period of 1 to 2.5 h in the other nine cases. In contrast, AraCTP retention times were relatively uniform in normal mononuclear blood cells from 11 patients with t1/2 values of 3.34 to 5.29 h (median 3.85 h). More importantly, AraCTP levels dropped by > 10% within the first hour after the end of the high-dose AraC infusion in eight of 11 cases. A post-therapeutic increase > 10% was not observed in any patient. Similar findings emerged after in vitro exposure of normal bone marrow cells from six healthy volunteers to 20 mumol/l AraC for 3 h revealing a > 10% decrease of intracellular AraCTP within the first post-treatment hour in all cases with AraCTP retention times of 2.29 to 8.63 h (median 3.20 h). These differences in AraCTP pharmacokinetics between leukemic and normal blood cells may provide the basis for a modified timing of AraC administration with the aim of selectively maintaining cytotoxic AraCTP levels in leukemic blasts while allowing an intermittent drop of AraCTP levels in normal cells.(ABSTRACT TRUNCATED AT 400 WORDS)
Leukemia 1992 Dec
PMID:Differences in the intracellular pharmacokinetics of cytosine arabinoside (AraC) between circulating leukemic blasts and normal mononuclear blood cells. 145 72

The prognosis and long-term results of a group of 57 acute megakaryoblastic leukaemia (M7-AML) patients was analysed from a multicentre perspective. Ages ranged from 4 to 83 years, median 49 years; 30 were males and 27 were females. The median follow-up time was 7 months, range 1-24 months. Early exits occurred in 12 cases, their median age being 71 years. Forty-five patients were treated with combined aggressive chemotherapy (CT) (n = 26) or low-dose cytarabine (LD-AraC) (n = 19). The following results were obtained with combined CT or AraC, respectively. Complete remission (CR) rates were 73% and 84%, 12-month survival (SV) were 37% and 26%, 24-month SV were 12% and 11%, median SV 10 and 4 months, and relapse rates (RR) were 68% and 94%. These differences were not statistically significant. Irrespective of the treatment modality, the results were better for children (n = 10) than for adults (n = 35): RR rates were 90% and 74%, median SV: 7 and 5 months, 12-month SV: 40% and 22%, 24-month SV; 30% and 9%, and RR: 78% and 81%, respectively; these differences also were not statistically significant. In addition, a literature review of 42 patients from 18 previous reports is presented, including seven cases treated with allogeneic bone marrow transplantation (BMT). The best results were obtained with BMT: 12 and 24 month SV was 86% and the RR was 0%. On the above-mentioned basis, we feel that children and young adults with M7-AML should be offered BMT. In patients over 60 years old or not eligible for aggressive chemotherapy or BMT, an interesting possibility would be the use of LD-AraC which allows a high CR rate, followed by a classical consolidation regimen in order to prevent early relapses.
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PMID:Long-term treatment results for acute megakaryoblastic leukaemia patients: a multicentre study. 148 53

Symptomatic patients with myelodysplastic syndromes (MDS) and 10-30% blasts in the bone marrow were treated with low-dose AraC (2 x 10 mg/m2 subcutaneously (sc) days 1-14) and GM-CSF (fully glycosylated, Sandoz/Schering-Plough, 2 x 150 micrograms protein/day sc) given either subsequently (days 15-21) or simultaneously (days 8-14 and one week rest). Evaluations were carried out after three courses (nine weeks); responding patients could be continued for two further cycles. Eighty-two patients with refractory anaemia and excess of blasts (RAEB), with (RAEBt) or without transformation, were evaluable: 45 RAEB and 37 RAEBt, mean age 64 years (range 17-80 years). A complete remission was achieved in 14 cases (17%), 11 had a good response (13%), and 12 a partial response (15%). Stable disease was found in 21 cases (26%). There were 12 cases of toxic death (15%), progression was noted in eight patients (10%), and death due to disease in three (4%). No difference existed between the two treatment arms with respect to response. Major adverse events during treatment were haemorrhage (25%), infections (23%), and fever with GM-CSF (21%). GM-CSF did not induce leukaemia nor contribute to haemorrhage induced by AraC, but gave rise to an overall response rate of 46% which is high and relatively durable as compared to other treatments in this disease.
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PMID:Treatment of myelodysplastic syndromes (MDS) and high leukaemic risk with low-dose cytosine arabinoside (LD-AraC) plus granulocyte-macrophage colony-stimulating factor (rh GM-CSF). The EORTC Leukaemia Group. 149 35

The use of new drugs in the treatment of AML could dramatically increase the cost of induction chemotherapy. To evaluate the cost-effectiveness of such new drugs, the overall cost to achieve complete remission (CR) with treatments including these drugs has to be compared to the cost of the daunorubicin-cytosine arabinoside (DNR-AraC) association, considered as the reference treatment. A retrospective analysis of charts from 15 patients treated with DNR-AraC was used to identify 228 items of cost, including general cost, diagnostic, supportive care, and chemotherapy. Eleven patients underwent CR after one course of chemotherapy for a cost of US$16,701 +/- 4451, and four patients achieved CR after two courses for a cost of US$37,130 +/- 4923. The chemotherapy represented only 1.4% of the total cost, supportive care 25% and general cost 56%. According to these data, the projective cost of a treatment with mitoxantrone instead of DNR was simulated in 40 untreated patients with AML. The better rate of CR obtained after one course of chemotherapy leads to a saving of 9% (US$1261) per patient, despite the higher cost of chemotherapy. Cost-effectiveness evaluation should be included in the clinical study of trials with new drugs.
Leukemia 1992 Jul
PMID:Cost of complete remission induction in acute myeloblastic leukemia: evaluation of the cost-effectiveness of a new drug. 162 92

1. Cytotoxic synergism of drugs cis-diamminedichloroplatinum(II) (cis-DDP) and arabinosylcytosine (araC) was studied both on the level of interaction with DNA in chemically determined conditions and on leukemia L1210 bearing mice. 2. AraC and its structural natural precursor cytidine were tested for the modulation of kinetics of bifunctional adducts production induced by cis-DDP in DNA. 3. This process plays the basic role in cytotoxic mechanism and antitumor activity of cis-DDP. 4. No interaction was seen between cis-DDP and araC. Further, presence of araC in reaction mixture had no effect on cis-DDP-DNA interaction. 5. Therefore, cytotoxic synergism does not arise in the araC-cis-DDP-DNA interaction and its origin is different. 6. Finding that cytidine has no synergistic effect on life span of leukemia L1210 bearing mice when administered together with cis-DDP it shows the difference between cytidine and araC. 7. The small structural difference between cytidine and araC is very important for synergism of cytotoxicity.
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PMID:Evaluation of synergism of drugs cis-diamminedichloroplatinum (II) and arabinosylcytosine on the level of chemical interaction with DNA and on the growth of mouse leukemia. 176 Nov 84

The present study provides evidence that green tea extract (GTE), consisting of polyphenol components, is a highly active nucleoside transport inhibitor. GTE markedly inhibited radiolabeled thymidine and uridine transport in mouse leukemia L1210 cells, with IC50 values of 3.2 and 8.0 mumol/L, respectively. GTE blocked the rescue effect of exogenous nucleosides and enhanced the cytotoxicity of AraC and MTX to L1210 cells and human hepatoma BEL-7402 cells. GTE markedly potentiated the inhibitory effect of AraC on leukemia L1210 and P388 in mice. These results indicate that GTE is potentially useful when combined with antimetabolites in cancer chemotherapy.
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PMID:Green tea extract inhibits nucleoside transport and potentiates the antitumor effect of antimetabolites. 178 98

Eighteen acute nonlymphoblastic leukemia patients greater than 60 yr., 12 at diagnosis and 6 in first relapse, were treated with the association of oral Idarubicin and subcutaneous Aracytin. One patient was not evaluable. Eight out of 17 patients achieved complete remission (47%), 4 patients died in induction and 5 proved resistant to treatments. Mucocutaneous and gastrointestinal toxicity was mild. The most frequent extra-hematological complications were infections. We observed an important hepatic toxicity in 1 case.
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PMID:Oral idarubicin plus cytosine arabinoside in the treatment of acute non lymphoblastic leukemia in elderly patients. 182 Sep 91

Pharmacologic and immunologic methods of ex-vivo bone marrow (BM) purging for acute nonlymphocytic leukemia (ANLL) were combined to augment the effect of either method alone. Etoposide (VP16; 20 to 30 micrograms/mL) with or without cytosine arabinoside (Ara C; 10 mg/mL) was used in tandem with the anti-CD33 monoclonal antibody (MoAb), MY9, chosen because CD33 is found on the stem cell pool in the majority of patients with ANLL. The agents were tested singly or sequentially, with a 1-hour incubation of the drugs preceding complement-mediated lysis using MY9. VP16 combined with Ara C killed up to 3.9 +/- 0.3 and 5.11 +/- 0.4 logs of the human ANLL cell lines HL60 and K562 at drug concentrations that killed only 1.2 +/- 0.1 logs of normal committed granulocyte/macrophage stem cells (CFU-GM). Adding a single exposure of the MY9 and complement (C') to the drug-treated cells, greater than 5.4 logs of HL60 were killed. Similar to other pharmacologic agents, no differential kill for clonagenic leukemic cells (colony-forming unit-leukemia; CFU-L) from patients with ANLL was seen for drug only treated blasts versus normal CFU-granulocyte-macrophage (CFU-GM), with less than 1 log CFU-L kill at drug concentrations that spared 1 log of CFU-GM. Similarly, only 1.1 +/- 0.3 logs of ANLL CFU-L were eliminated using MY9 and C'. However, with the sequential VP16/Ara C----MY9 + C' treatment, synergy was demonstrated and 2.6 +/- 0.3 logs of CFU-L were eliminated. Because CD33 is also found on the normal CFU-GM pool, two-stage long-term BM cultures were performed to determine pluripotent stem cell elimination by the drug/MoAb purging combination. No difference of CFU-GM or BFU-E production at 4 to 6 weeks of culture for VP16/Ara C, MY9 + C', or VP16/AraC----My9 + C' treated cells was seen compared with untreated controls indicating sparing of early progenitor cells. Sequential ex vivo treatment of human ANLL CFU-L with VP16/Ara C followed by complement-mediated lysis using MY9 synergistically kills CFU-L while sparing early normal hematopoietic progenitor cells, and thus may be a more effective way to purge BM than either alone.
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PMID:Anti-CD33 monoclonal antibody and etoposide/cytosine arabinoside combinations for the ex vivo purification of bone marrow in acute nonlymphocytic leukemia. 198

In 1977, Frindel et al. reported the presence in fetal calf bone marrow of a low molecular factor, the tetrapeptide Ac-N-Ser-Asp-Lys-Pro (AcSDKP), capable of inhibiting in vivo the hematopoietic pluripotent stem cell (CFU-S) recruitment into DNA synthesis and to increase the survival of mice which had received lethal doses of cytosine arabinoside (AraC), a phase-specific drug. Considering the potential clinical importance of CFU-S proliferation inhibitor during anticancer chemotherapy and the importance of monitoring the inhibitor by immunological methods, we tried to determine if a similar inhibitor is present in humans. Preliminary results indicate the presence in human placenta of an inhibitor coeluted with AcSDKP and which is effective in inhibiting murine CFU-S.
Leukemia 1991 Mar
PMID:Human placental low molecular weight factors inhibit the entry into cell cycle of murine pluripotent stem cells. 201 83

We treated 47 adult patients with de novo myelodysplastic syndrome (MDS) by an anthracycline-AraC regimen. Median age was 54, and M/F 1.3. At diagnosis, 26 patients had refractory anaemia with an excess of blasts in transformation (RAEB-T) three had refractory anaemia (RA), 11 had refractory anaemia with excessive blasts (RAEB) and seven had chronic myelomonocytic leukaemia (CMML). Treatment was started within 3 months of diagnosis in 30 patients, and after more than 3 months in the 17 remaining patients. At the onset of treatment, 16 patients had progressed to acute myeloid leukaemia (AML). Twenty-two patients (47%) reached complete remission (CR), 10 (21%) had hypoplastic death and 15 (32%) had resistant disease. Median actuarial disease-free interval was 11 months. Median actuarial survival was 14 months from diagnosis and 10 months from the onset of treatment. A significantly higher CR rate was found in patients with RAEB-T at diagnosis (69% v 19% in patients with other FAB subtypes: P = 0.008), and in patients treated within 3 months of diagnosis. Using multivariate analysis, RAEB-T at diagnosis emerged as the most powerful prognostic factor of CR achievement. Karyotype was the only significant prognostic factor of disease-free interval, with a median of 16.5 months in patients with normal karyotype versus 4 months in patients with normal findings (P = 0.018). A subgroup of 15 patients with RAEB-T at diagnosis and normal karyotype, who had a CR rate of 80% and a median actuarial disease-free interval of 18 months, could be identified. Our results confirm that, overall, intensive chemotherapy has limited efficacy in MDS, especially when compared with allogeneic bone marrow transplantation (BMT). Relatively favourable results were obtained in our patients with RAEB-T at diagnosis, however, particularly those with normal karyotype. In that subgroup, intensive chemotherapy may be recommended, especially before BMT, as a high risk of relapse after BMT in patients with RAEB-T allografted as first line therapy has been reported.
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PMID:Prognostic factors in adult de novo myelodysplastic syndromes treated by intensive chemotherapy. 202 75


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