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Biomedical subjects

E Estey

Publications and source records attributed to E Estey.

At least 163 records · Page 9Linked to original sources

AML-associated cytogenetic abnormalities (inv (16), del (16), t(8;21)) in patients with myelodysplastic syndromes.

Evidence suggests that prognosis in patients with myelodysplastic syndromes (MDS) or acute myelogenous leukemia (AML) depends more on karyotype than on formal classification as either MDS or AML according to the French-American-British (FAB) system. We provide further evidence of overlap between these two entities, reporting 4 patients who presented with either inv(16) (p13q22), del(16) (q22), or t(8;21) despite an FAB diagnosis of MDS rather than the diagnosis of AML with which these abnormalities are generally associated. In 3 patients, disease was relatively long-standing (3-10 months) prior to diagnosis, suggesting that the association between MDS and these cytogenetic abnormalities may not merely reflect a transient phenomenon. Two patients with inv(16) and the MDS subtype refractory anemia with excess blasts in transformation (RAEB-t) received AML-type chemotherapy as did a patient with t(8;21) and RAEB-t. All entered CR paralleling the high CR rate seen in patients with AML and these abnormalities. Our data support the concept that MDS and AML may be different manifestations of the same disease.

Adolescent↗

Altered conformation of the p53 protein in myeloid leukemia cells and mitogen-stimulated normal blood cells.

Expression of the normal p53 gene promotes cell differentiation, maturation and apoptosis. The mutant p53 gene, which does not function normally, is frequently expressed at elevated levels in tumor cells [for review see Lane, D.P. & Benchimol, S. (1990). Genes Dev., 4, 1-8]. We have analysed the expression of and mutational change in the p53 gene in the peripheral blood cells of 49 primary acute myeloid leukemia (AML) patients. The p53 protein levels were elevated in 37 patients (75%) when measured by immunoprecipitation with antibodies PAb1801 and PAb421, which recognize both normal and mutant forms of the protein. The p53 protein from 32 of these 37 patients was immunoprecipitated by PAb240, which recognizes a conformation of p53 protein associated with point mutations. However, point mutations were detected by single-stranded conformation polymorphism (SSCP) assay and direct sequencing in only three patients at codons 178, 245, 273 and 290. Growth stimulation of normal lymphocytes also generated p53 which was immunoprecipitable by PAb240. Thus, alteration of p53 conformation, rather than acquisition of point mutations, could be the mechanism underlying the increased proliferation of myeloid cells in most AML patients.

Acute Disease↗

Significance of the P210 versus P190 molecular abnormalities in adults with Philadelphia chromosome-positive acute leukemia.

We investigated the significance of p210 and p190 molecular abnormalities in 32 adults with Philadelphia chromosome (Ph)-positive acute leukemia. p210 was detected in 15 patients (47%), p190 in 16 (50%), and both in one (3%). p210 was noted in 11 of 24 patients (46%) with acute lymphocytic leukemia, and in four of eight patients (50%) with acute myelogenous or undifferentiated leukemia. Among 29 patients with untreated disease (p210, 14 patients; p190, 15 patients), no significant differences in the two molecularly distinct groups were observed by pretreatment characteristics including age, degree of organomegaly, anemia, leukocytosis, thrombocytopenia, occurrence of karyotypic abnormalities in addition to Ph, or residual diploid metaphases. Complete response (CR) rates were also similar. Although the remission duration tended to be longer with p190 (P = .08), the differences were minor (median duration 29 v 20 weeks) and not paralleled by differences in survival rate. In 10 patients studied by karyotypic analysis in remission, two of four patients with p190 and two of six patients with p210 showed 100% normal metaphases. One of the seven patients (14%) with p210 who achieved CR manifested a morphologic picture of second chronic-phase chronic myelogenous leukemia lasting for 1 month. We conclude that the molecular studies in Ph-positive acute leukemia are not associated with significantly different clinico-laboratory, karyotypic, or prognostic implications.

Adult↗

Mitoxantrone and high-dose etoposide for patients with relapsed or refractory acute leukemia.

Among 35 patients with relapsed or refractory acute myelogenous leukemia (AML) who received salvage chemotherapy, 28 were treated with mitoxantrone (7.5 mg/m2/d intravenously [IV] over 1 hour for 5 days) and etoposide (VP-16) (2 g/m2 over 4 days either as a daily infusion or as two daily doses). Seven patients received mitoxantrone (6 mg/m2/d for 5 days) and VP-16 (1500 mg/m2 over 3 days). The median duration of the initial complete remission (CR) was 6 months and 83% of the patients had initial CR that lasted 12 months or less. Forty-six percent of the patients were undergoing a second or subsequent salvage attempt. Eight patients (23%) achieved CR; seven of these CR were obtained after one course of therapy. Twelve patients (33%) died and 15 patients (42%) had disease that was resistant to treatment. Patients undergoing a first salvage attempt had a higher incidence rate of CR than those undergoing a second or subsequent salvage attempt (37% versus 6%; P = 0.03). CR rates were also higher in patients with a favorable (translocation 8;21 or 15;17) or diploid karyotype compared with other patients (32% versus 8%; P = 0.10). The median survival time was 2 months for all patients and 8 months for patients achieving CR. Mucositis occurred in 74% of the patients and was severe in 32%. Diarrhea and rash occurred in less than 33% of the patients. Fever was noticed in all but 1 of the patients and documented infections occurred in 65% of the patients. Six patients had pancytopenia or thrombocytopenia that lasted more than 42 days from the initiation of treatment. Although mitoxantrone and high-dose VP-16 is an effective antileukemic regimen, it is associated with a high incidence of mucositis. Strategies that are used to limit mucosal damage may improve the tolerance of this combination.

Adult↗

Phase I clinical investigation of benzisoquinolinedione (amonafide) in adults with refractory or relapsed acute leukemia.

After Phase I studies of benzisoquinolinedione (amonafide) in solid tumors identified myelosuppression as the dose-limiting toxicity, we conducted a Phase I study in patients with relapsed or refractory acute leukemia to define the optimal dose. Amonafide was given i.v. over 2-4 h daily for 5 days. The starting dose was 600 mg/m2/day with subsequent escalation to 750, 900, 1100, 1400, and 1800 mg/m2/day. Thirty-eight courses were administered to 24 patients, of whom 12 participated in concomitant pharmacological studies. Nausea and vomiting, transient orange discoloration of the skin, and tinnitus occurred at all dose levels. The latter symptom, along with lightheadedness and flushing, was related to infusion duration; this was increased to 4 h with doses greater than or equal to 900 mg/m2. The dose-limiting toxicities were mucositis and painful skin erythema which occurred in all 4 patients treated with 1800 mg/m2. No remissions occurred. Clearing of peripheral blood blasts occurred in 67% of patients treated with 1100 mg/m2 and in all patients treated with greater than or equal to 1100 mg/m2/day. A decrease in marrow leukemic infiltrate (% blasts x % cellularity) to less than 10% occurred in 15 and 50% of patients treated at these levels, respectively. There were 10 deaths (42%), which were unrelated to dosage. The harmonic mean terminal plasma half-life was 4.6 h (range, 2.5-35.5 h). Three patients had long drug half-lives of 9.7, 16.4, and 35.5 h and each had initial bilirubin levels greater than 1.0 mg/dl. The average urinary excretion of amonafide over 5 days was 3.5% of the total dose. This establishes 1100-1400 mg/m2/day for 5 days as the maximally tolerated dose of amonafide for studies in acute leukemia.

Acute Disease↗

Erythropoietin treatment in patients with myelodysplastic syndrome and anemia.

Hematological disorders are commonly complicated by anemia, and the symptoms of red cell deficiency adversely affect the quality of life. Erythropoietin is a glycoprotein which controls red blood cell production. Recombinant human erythropoietin, 50 U/kg/day, was given subcutaneously to 16 patients with myelodysplastic syndrome and anemia. All but one patient was transfusion dependent. Diverse pretreatment endogenous serum erythropoietin levels were noted and ranged from 17 to 3616 IU/l. Two patients (12.5%) demonstrated an improvement in hemoglobin levels obviating the need for transfusions. Their responses lasted 5+ and 7 months with maintenance erythropoietin treatment. The responders had endogenous serum erythropoietin levels of 44 and 170, respectively. Treatment was generally tolerated without constitutional side-effects. However, three patients developed thrombocytopenia and one developed joint pain and leukocytosis on treatment. Overall, six patients showed changes in non-erythroid cells: two patients had an increase in platelet counts; three patients, a decrease in platelet counts; and one patient, an increase in white blood cell counts. Most of these changes reversed rapidly once erythropoietin was stopped. It is concluded that (a) serum erythropoietin levels are extremely variable in anemia patients with myelodysplastic syndrome, (b) only a minority of patients benefit from treatment with recombinant human erythropoietin, and (c) erythropoietin can affect cells of the myeloid and megakaryocytic lineage in a small proportion of patients.

Aged↗

High-dose chemotherapy and unpurged autologous bone marrow transplantation for acute leukemia in second or subsequent remission.

The authors administered high-dose chemotherapy with cyclophosphamide, BCNU (carmustine) and VP-16 (etoposide) plus autologous bone marrow transplantation (ABMT) to 22 adult patients with relapsed acute leukemia in second or subsequent remission. The marrow was not treated ex vivo. The long-term, disease-free survival rate was 14%. Comparison of results with other treatments can be difficult because of patient selection biases. The concept of inversion (achievement of a longer remission with salvage therapy than with prior treatments) is proposed to compare treatment results. Three patients remain in complete remission beyond 4 years, with inversions. More intensive cytoreductive regimens will be needed to improve results.

Adult↗

Pharmacologically directed design of leukemia therapy.

The ability to accumulate and retain the active metabolite of Ara-C varies widely among patients. Our studies demonstrate a significant correlation between clinical response and the pharmacokinetics of Ara-CTP in leukemia cells during therapy. Knowledge of the cellular pharmacology of Ara-CTP has been used to optimize dose rates and to design combination treatment schedules. An understanding of the cellular pharmacodynamics of other drugs is likely to be a useful parameter for planning treatment protocols.

Antineoplastic Combined Chemotherapy Protocols↗

Effects of granulocyte-macrophage colony-stimulating factor in iatrogenic myelosuppression, bone marrow failure, and regulation of host defense.

In early studies, recombinant human granulocyte-macrophage colony-stimulating factor (GM-CSF) has been found to reduce the depth and duration of granulocytopenia in the settings of cancer chemotherapy and autologous bone marrow transplantation. In patients with myelodysplastic syndrome or aplastic anemia. GM-CSF has produced increased marrow cellularity and marked leukocyte responses, and multilineage effects have been observed in some patients. The available data suggest that the use of GM-CSF in these settings is associated with a decreased incidence of infection as compared with that in historical controls or pretreatment periods and that it may enhance the ability to deliver optimal doses of cancer chemotherapy. Other findings suggest that GM-CSF may be useful in regulating host response to infection when used in combination with antimicrobial therapy in neutropenic patients. However, a precise determination of the ability of this agent to significantly affect patient morbidity or mortality in these various contexts awaits the results of larger, longer-term, randomized, controlled trials.

Bone Marrow Diseases↗

Patient-specific dose rate for continuous infusion high-dose cytarabine in relapsed acute myelogenous leukemia.

We hypothesized that the steady-state concentration of intracellular cytarabine 5'-triphosphate (ara-CTPss) in leukemia cells is proportional to the dose rate of cytarabine (ara-C) during continuous infusion. To evaluate this possibility, patients with acute myelogenous leukemia in relapse were treated with two sequential schedules of serially increasing ara-C dose rates over a total of 36 hours. Schedule I consisted of serial infusions of 250, 500, and 750 mg/m2 each over 12 hours. Subsequently, patients entered on schedule II received 500, 1,000, and 1,500 mg/m2 serially, each over 12 hours. Steady-state levels of ara-CTP were achieved within four hours after beginning ara-C infusion and, in separate studies of a single ara-C dose rate, were shown to be maintained beyond 36 hours. Four patients treated with schedule I and two patients treated with schedule II showed a linear dose rate-dependent increase-of ara-CTPss at all three dose rates. The cells of one patient on schedule I and two patients on schedule II had a dose rate-dependent ara-CTPss increase only over the first two dose levels, while no increase or lower ara-CTPss was observed at the third dose rate. The ara-CTPss of one patient on schedule II did not change. These results suggest that there is a proportionality between the continuous infusion dose rate of ara-C and the ara-CTPss in circulating leukemia cells within the dose range of 250 to 1,000 mg/m2 over 12 hours. This opens the possibility that pharmacologic determinations may be used to redirect the ara-C dose rate to achieve a desired ara-CTPss level in leukemia blasts during therapy.

Adult↗

Response to salvage therapy and survival after relapse in acute myelogenous leukemia.

The response to and survival following first salvage therapy regimens for 243 patients with acute myelogenous leukemia (AML) treated between 1974 and 1985 were evaluated. Eighty (33%) patients obtained a complete remission (CR), 24% died prior to achieving a response, and 43% were resistant on their first salvage regimen. The median survival was 18 weeks. Five percent overall and 16% of the CR patients are predicted to survive for more than 5 years. The factor most strongly associated with response and survival was the duration of the initial remission with 49 of 82 (60%) patients whose initial CR duration was at least 1 year in duration obtaining a second CR v 31 of 161 (19%) for patients with a shorter remission (P less than .01). Age, liver function, serum lactic dehydrogenase (LDH), karyotype, and the proportion of blasts plus promyelocytes present at the time of starting salvage therapy were strongly associated with probability of response and survival. Multivariate analysis was used to develop logistic regression and proportional hazard models to predict probability of response and survival, respectively. The major regimens used were conventional-dose cytarabine (ara-C) (combined with anthracyclines or amsacrine), high-dose ara-C, rubidazone, amsacrine (AMSA), other anthracyclines, and autologous or allogeneic transplant programs. After allowing for the prognostic factors in the models, specific treatment regimens were not strongly associated with prognosis.

Adult↗

Prediction of survival during induction therapy in patients with newly diagnosed acute myeloblastic leukemia.

Among 569 patients with newly diagnosed AML, 16% died in the 4 weeks following initiation of remission induction therapy. Eight pretreatment characteristics were found to be independently associated with 4-week survival: performance status, bilirubin, age, neutrophil count, fibrinogen, albumin, hemoglobin, and creatinine. A model incorporating these characteristics prospectively stratified a separate group of 198 patients into two comparably sized groups differing substantially in both 4-week survival rates (71% (95% confidence limits, 61-80%) vs. 91% (95% confidence limits, 83-96%] and in survival rates throughout remission induction. Characteristics associated with failure to survive 4 weeks were unassociated with resistance to therapy. This suggests that patients who fail to survive induction are qualitatively different than patients who survive induction but exhibit resistance to treatment. Different therapeutic strategies might be appropriate in the two groups. The model presented here can be used to identify patients at increased risk of death during remission induction.

Adult↗

Effect of 1-beta-D-arabinofuranosylcytosine (ara-C) on nuclear topoisomerase II activity and on the DNA cleavage and cytotoxicity produced by 4'-(9-acridinylamino)methanesulfon-m-anisidide (m-AMSA) and etoposide in m-AMSA-sensitive and -resistant human leukemia cells.

The ability of a noncytotoxic dose of ara-C to modulate the amount of 4'-(9-acridinylamino)-methanesulfon-m-anisidide (m-AMSA)- or etoposide-induced topoisomerase II-mediated DNA cleavage and cytotoxicity was examined in m-AMSA-sensitive and -resistant HL-60 human leukemia cells. Ara-C pretreatment (0.1 microM x 48 hr) sensitized m-AMSA-sensitive cells to the cytotoxicity and DNA cleavage produced by both m-AMSA and etoposide. The actions of m-AMSA in the m-AMSA-resistant cells were affected minimally by ara-C. By contrast, ara-C enhanced etoposide-induced DNA cleavage and, to an even greater extent, etoposide-induced cytotoxicity in m-AMSA-resistant cells. These cells were only minimally cross-resistant to etoposide. Ara-C did not affect the cellular uptake of m-AMSA or etoposide, the amount of 0.35 M NaCl-extractable nuclear topoisomerase II activity from either cell line, or the ability of this enzyme activity to covalently bind to DNA in the presence of the drugs, m-AMSA- and etoposide-induced DNA cleavage is thought to result from drug-induced stabilization of a topoisomerase II-DNA complex. The ability of ara-C to modulate this effect and associated cytotoxicity appears to be mediated by the effects of ara-C on cellular targets other than topoisomerase II but which are important to topoisomerase II-mediated events, such as protein-associated DNA cleavage. A good candidate for such a target may be cellular chromatin.

Amsacrine↗

Cell cycle stage dependent variations in drug-induced topoisomerase II mediated DNA cleavage and cytotoxicity.

The DNA cleavage produced by 4'-(9-acridinylamino)methanesulfon-m-anisidide (m-AMSA) in mammalian cells is putatively mediated by topoisomerase II. We found that in synchronized HeLa cells the frequency of such cleavage was 4-15-fold greater in mitosis than in S while the DNA of G1 and G2 cells exhibited an intermediate susceptibility to cleavage. The hypersensitivity of mitotic DNA to m-AMSA-induced cleavage was acquired relatively abruptly in late G2 and was lost similarly abruptly in early G1. The susceptibility of mitotic cells to m-AMSA-induced DNA cleavage was not clearly paralleled by an increase in topoisomerase II activity (decatenation of kinetoplast DNA) in 350 mM NaCl extracts from mitotic cells compared to similar extracts from cells in G1, S, or G2. Furthermore, equal amounts of decatenating activity from cells in mitosis and S produced equal amounts of m-AMSA-induced cleavage of simian virus 40 (SV40) DNA; i.e., the interaction between m-AMSA and extractable enzyme was similar in mitosis and S. The DNA of mitotic cells was also hypersensitive to cleavage by 4'-demethylepipodophyllotoxin 4-(4,6-O-ethylidene-beta-D-glucopyranoside) (etoposide), a drug that produces topoisomerase II mediated DNA cleavage without binding to DNA. Thus, alterations in the drug-chromatin interaction during the cell cycle seem an unlikely explanation for results in whole cells. Cell cycle stage dependent fluctuations in m-AMSA-induced DNA cleavage may result from fluctuations in the structure of chromatin per se that occur during the cell cycle.(ABSTRACT TRUNCATED AT 250 WORDS)

Amsacrine↗

Saturation of 1-beta-D-arabinofuranosylcytosine 5'-triphosphate accumulation in leukemia cells during high-dose 1-beta-D-arabinofuranosylcytosine therapy.

Twenty-seven patients with refractory leukemia were treated with 1-beta-D-arabinofuranosylcytosine (ara-C), 0.3 to 3.0 g/m2 as i.v. infusions over 1, 2, 4, or 24 h. The pharmacokinetics of ara-C in plasma and its 5'-triphosphate (ara-CTP) in leukemic cells from peripheral blood were studied after a single infusion of 3 g/m2 over 2 h in 13 patients. Accumulation of ara-CTP in leukemic cells remained linear until 1 to 2 h after the infusion. At the time when the rate of ara-CTP accumulation deviated from linearity, the plasma concentration of ara-C was 5- to 20-fold lower [8.1 +/- 4.4 (SD) microM] than the steady-state level during the infusion. Plasma ara-C and cellular ara-CTP pharmacokinetics were studied after two serial infusions in 14 additional patients. Varying the duration of infusion of an ara-C dose between 1, 2, and 4 h (corresponding to infusion rates of 3000, 1500, and 750 mg/m2/h) did not substantially change the rate of ara-CTP accumulation by leukemic cells. The peak ara-CTP concentration and the area under the concentration times time curve (AUC) of ara-CTP in leukemic cells increased with prolongation of the infusion. Although steady-state concentration of ara-C and AUC of ara-C in plasma were proportionally reduced by 1.0 or 0.5 g/m2 infusion over 2 h, ara-CTP accumulation rate and AUC in leukemic cells did not change compared with administration of 3 g/m2 over 2 h. However, when the infusion rate was further reduced to 0.4 or 0.3 g/m2 over 2 h, resulting in steady-state plasma ara-C concentrations of less than 7 microM, the accumulation rate of ara-CTP was substantially reduced as was the ara-CTP intracellular AUC. The cellular elimination rate of ara-CTP remained constant under all infusion conditions. These findings support the conclusion that high-dose ara-C therapy, as currently administered, results in plasma ara-C concentrations that saturate the accumulation of ara-CTP by circulating leukemic cells. We recommend that intermediate dose rates, 200 to 250 mg/m2/h, be evaluated in future studies as an alternative to the substantially higher ara-C dose rates currently in use.

Arabinofuranosylcytosine Triphosphate↗