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Biomedical subjects

M J Keating

Publications and source records attributed to M J Keating.

At least 289 records · Page 16Linked to original sources
PubMed1987

Effect of amsacrine on ara-CTP cellular pharmacology in human leukemia cells during high-dose cytarabine therapy.

The combination of high-dose cytarabine (ara-C) and amsacrine (m-AMSA) is effective treatment for relapsed adult acute leukemia. Studies were performed to determine if m-AMSA affected the pharmacokinetics of the active triphosphate ara-CTP in HL-60 and K562 cells in culture. No significant differences were observed in accumulation, rate of elimination, or total intracellular exposure to ara-CTP in cultures treated with 100 microM ara-C alone or in combination with 1 microM m-AMSA. In clinical investigations, the accumulation and retention of ara-CTP in circulating leukemic cells were studied in five patients after two serial doses of ara-C (3 g/m2 infused over 2 hours) and in six additional patients in whom the second dose of ara-C was accompanied by an infusion of m-AMSA (30 mg/m2 infused over 1 hour). While substantial differences were observed in the cellular pharmacokinetics of ara-CTP among patients, the rate of ara-CTP elimination and the total intracellular exposure to ara-CTP in individuals were remarkably similar after each ara-C infusion. Infusion of m-AMSA with the second dose of ara-C did not significantly affect the cellular pharmacokinetics of ara-CTP. These studies demonstrate the feasibility and utility of conducting investigations of the cellular pharmacology of drug-drug interactions in human leukemic cells during therapy.

Acute Disease↗
PubMed1987

Prognosis of chronic lymphocytic leukemia: a multivariate regression analysis of 325 untreated patients.

Three hundred twenty-five previously untreated patients with chronic lymphocytic leukemia were analyzed to identify significant prognostic factors for survival. Univariate analysis identified the following characteristics associated with survival: (1) clinical characteristics: age, race, sex, performance status, lymphadenopathy, and hepatosplenomegaly; (2) hematologic parameters: WBC count, absolute lymphocyte and granulocyte counts, hemoglobin level, and platelet count; and (3) biochemical parameters: serum albumin, calcium, uric acid, lactate dehydrogenase, alkaline phosphatase, BUN, and creatinine. Multivariate regression analysis in a randomly selected training subset of 217 patients demonstrated that the combination of uric acid, alkaline phosphatase, lactate dehydrogenase, external lymphadenopathy, and age had the strongest predictive relation to survival time. The resulting model was validated in the remaining independent subset of 108 patients and led to classification of patients into low, intermediate, and high-risk groups with five-year survival rates of 75%, 59%, and 14%, respectively, and with distinctively different annual mortality rates (P less than .01). Both the regression model and Rai staging were highly effective in identifying risk groups among the entire patient population (P less than 0.001). Overall the regression model was superior to Rai staging in defining prognostic risk groups. In addition, it was able to separate patients into significantly different risk categories within each Rai stage, thus improving on the prognostic prediction of individual patients with chronic lymphocytic leukemia.

Adult↗
PubMed1986

Clinical and prognostic features of Philadelphia chromosome-negative chronic myelogenous leukemia.

Between 1965 and 1982, 105 patients with a diagnosis of Philadelphia chromosome-negative chronic myelogenous leukemia were referred to our institution with minimal or no prior therapy. The median age was 63 years and 64% were males. The overall median survival from time of referral was 14 months; 53% of patients survived 1 year and only 10% survived beyond 5 years. At the time of analysis, 92 patients (88%) were dead, 56% of deaths being preceded by a blastic crisis. Compared with Philadelphia chromosome-positive disease, patients with Philadelphia chromosome-negative chronic myelogenous leukemia were older and had a significantly higher incidence of anemia, thrombocytopenia, monocytosis, marrow blasts, decreased marrow megakaryocytes and a lower incidence of basophilia and thrombocytosis. Chromosomal abnormalities occurred in 33% of patients and consisted most frequently of trisomy 8, or an additional chromosome C, loss of the Y chromosome, or abnormalities in chromosomes #5 and #7. Of nine pretreatment characteristics significantly associated with poor survival, a multivariate analysis identified four to have independent additive prognostic significance: severe thrombocytopenia, hemoglobin levels less than 10 g/dl, increasing peripheral blasts and promyelocytes, and age 60 years or older. Monocytosis was not of prognostic significance. The derived prognostic model divided patients into three risk groups, low, intermediate, and high, with median survivals of 36, 16, and 3 months, respectively. The authors conclude that Philadelphia chromosome-negative chronic myelogenous leukemia is a distinct entity among the myeloproliferative syndromes with characteristic clinical and laboratory features and a poor prognosis. Prognostic factors and related risk categories were demonstrated within this disease entity.

Adolescent↗
PubMed1986

Early intensification and short-term maintenance chemotherapy does not prolong survival in acute myelogenous leukemia.

Forty-one previously untreated patients with a diagnosis of acute myelogenous leukemia (AML) were entered on a study using early intensification followed by a short-term maintenance chemotherapy. Induction and early intensification consisted of three to four cycles of doxorubicin, vincristine, cytosine arabinoside (Ara-C) and prednisone (ADOAP) in escalating dosages. Maintenance therapy used three cycles of Ara-C thioguanine (AT), followed by three cycles of cyclophosphamide and rubidazone with vincristine and prednisone (CROP). Median total duration of therapy was 9 months. The overall complete remission (CR) rate was 73%. Tolerance to chemotherapy and dose escalation were better for patients who received their induction and early intensification in the protected environment. The overall median survival was 75 weeks. Compared to a historical control group treated with long-term maintenance chemotherapy, patients achieving CR on the current study had similar median remission (52 versus 65 weeks; P = 0.3) and survival durations (94 versus 98 weeks). This regimen using early intensification and short-term maintenance chemotherapy did not improve the overall prognosis of this AML population.

Adolescent↗
PubMed1986

The association of specific "favorable" cytogenetic abnormalities with secondary leukemia.

Eight patients with secondary leukemia and specific cytogenetic abnormalities involving inversion of chromosome 16, or translocations between chromosomes 15 and 17, or 8 and 21, are presented. Seven of them (87%) achieved complete remission with chemotherapy. The occurrence of these karyotypes, which is unusual in secondary leukemia, and the favorable response to chemotherapy are discussed in relation to the pathogenesis of the disease.

Adult↗
PubMed1986

Hematologic remission and cytogenetic improvement induced by recombinant human interferon alpha A in chronic myelogenous leukemia.

We treated 17 patients who had Philadelphia-chromosome-positive chronic myelogenous leukemia (4 of whom had not received therapy and 13 of whom had been treated with hydroxyurea or busulfan for less than six months) with recombinant human interferon alpha A (Roferon-A). The interferon was given as 5 X 10(6) units per square meter of body-surface area per day intramuscularly during induction therapy. Fourteen patients responded to the treatment, of whom 13 had a hematologic remission and 1 had a partial hematologic remission. The median number of white cells in those patients declined from 60.9 X 10(3) to 3.4 X 10(3) per microliter, and the median number of platelets decreased from 476 X 10(3) to 231 X 10(3) per microliter. Among the five responding patients who had splenomegaly before treatment, the spleen size returned to normal in four and decreased by 75 percent in one, although it remained enlarged. Bone marrow cellularity declined from a median of 92.5 percent to a median of 57.5 percent. In six of the patients with hematologic remission, complete suppression of Philadelphia cells was observed on at least one examination. Of the 14 patients who responded, 11 have received the interferon therapy for 9 to 15 months. One patient relapsed during the treatment, and the treatment has been temporarily interrupted in two patients because of toxicity. These data are preliminary and will need further confirmation, but they suggest that recombinant human interferon alpha A is effective in inducing hematologic remission in most patients with benign-phase chronic myelogenous leukemia and in suppressing the Philadelphia chromosome in some of these patients.

Adolescent↗
PubMed1986

Phase I-II clinical and pharmacologic studies of high-dose cytosine arabinoside in refractory leukemia.

Sixty-four patients with refractory acute leukemia were treated with high-dose cytosine arabinoside given at a dosage of 3 g/m2 intravenously over two hours every 12 hours for four to 12 doses, repeated at two- to three-week intervals. Complete remissions were observed in 16 patients (25 percent), and the median duration of remission was three months (range, one to 10 months). Remission rates were similar for patients with acute myelogenous and acute lymphocytic leukemia (24 and 27 percent, respectively). Response rates were significantly higher in patients with initial remission durations of more than six months than in those with shorter remissions or those in whom there was no response to front-line therapy (41 and 9 percent; p less than 0.01). Similarly, patients with disease sensitive to conventional cytosine arabinoside had higher response rates than did those with resistant disease (54 and 17 percent; p = 0.03). Serial in vivo measurements of intracellular concentrations of the active metabolite of cytosine arabinoside in peripheral blasts following the initial dose demonstrated considerable individual variation. Favorable intracellular pharmacology of this active metabolite, manifested by its higher intracellular concentrations 12 hours after the first dose, by longer half-lives of active metabolite levels, and by higher values of the measured area under the curve of its accumulation and retention, was associated with higher response rates. Central nervous system toxicity occurred in 24 percent of patients, and pulmonary toxicity occurred in 22 percent; both were dose-limiting and dose-related. Other toxicities included nausea, vomiting, diarrhea, conjunctivitis, photophobia, cytosine arabinoside fever, skin rashes, and hepatic dysfunction. Response rates were similar for schedules utilizing four to six doses at two-week intervals or nine doses at three-week intervals (27 percent versus 25 percent). The schedule of 12 doses had a more rapid antileukemic effect but resulted in significantly higher toxicity and mortality rates during therapy with a similar overall response rate (21 percent). Thus, high-dose cytosine arabinoside is an effective regimen with substantial toxicity in patients with acute leukemia.

Adolescent↗
PubMed1986

Acute promyelocytic leukemia. M.D. Anderson Hospital experience.

Sixty patients with acute promyelocytic leukemia were treated between 1973 and 1984. The overall median survival was 16 months with a five-year survival rate of 31 percent. The complete remission rate was 53 percent and was similar whether they received amsacrine- or anthracycline-based regimens (60 percent versus 51 percent). The median remission duration was 29 months. At five years, 43 percent of patients with responses to treatment had continuous remission and 57 percent were alive. Salvage therapy produced remissions in 53 percent of patients during first relapse, with two long-term survivors after further consolidation with bone marrow transplantation. Early fatal hemorrhage associated with disseminated intravascular coagulopathy during induction therapy occurred in 16 patients (26 percent). Multivariate analysis of the pretreatment patient characteristics significantly associated with an increased risk of fatal hemorrhage identified four that have primary prognostic importance: thrombocytopenia, elevated absolute blast and promyelocyte counts, old age, and anemia. Patients having up to two unfavorable features had a low risk of fatal hemorrhage compared with those who had more than two (5 percent versus 58 percent; p less than 0.0001). Overall, patients who received heparin had a lower incidence of fatal hemorrhage than those who did not (19 percent versus 32 percent). Heparin therapy was not beneficial to those at low risk but was associated with a trend towards decreased hemorrhagic deaths among high-risk patients (45 percent versus 67 percent). Cytogenetic studies demonstrated the characteristic 15;17 translocation in 73 percent of patients with analyzable metaphases, whereas 12 percent had other karyotypic abnormalities. Remission induction was often associated with a gradual atypical morphologic evolution into remission without intermediate hypoplasia with the interim marrows showing a high proportion of blasts. It is concluded that acute promyelocytic leukemia is a unique disease with a high potential for cure. Knowledge of its prognosis using present frontline and salvage therapy, of the factors related to fatal hemorrhage, and of the unusual patient marrow profiles during remission induction may improve the therapeutic approach.

Aminoacridines↗
PubMed1986

Quantitative analysis of the oral complications of antileukemia chemotherapy.

Almost half of 1500 patients (46.9%) treated for acute leukemia developed chemotherapy-related oral infections, oral mucositis, and/or oral hemorrhages at some time during their hospitalization. The frequencies of 34.2% for infections, 16.3% for mucositis, and 13.6% for hemorrhages were each within 1.3% to 3.1% of those previously reported from this institution for smaller groups of patients. The stomatologic disruptions reflected the cytotoxic, myelosuppressive, and immunosuppressive properties of the antileukemia drugs. Because there are as yet no alternatives to the use of potent stomatotoxic drugs for the treatment of acute leukemia, it is essential that their side effects be kept to a minimum by early recognition and appropriate treatment.

Acute Disease↗
PubMed1986

Prognostic factors for survival of 194 patients with low infiltrate leukemia.

Prognostic factors were identified from the histories of 194 patients diagnosed as having low infiltrate leukemia (LIL) between 1973 and 1981, when the policy was to delay treatment until there was evidence of progressive disease or life-threatening morbidity. Their median age was 59 yr; 63% were male; 30 had had a malignant disease previously. Presenting symptoms included anemia, 82%; infections, 15%; and hemorrhage, 16%. The group's median survival was 42 weeks, with high marrow cellularity and percentage of blasts, impairment of bone marrow, liver or renal function, age over 65 yr and performance status less than 80% associated with poorer survival. Cytogenetic changes associated with poor survival included loss of chromosome 5 or 7, additional chromosome 8, karyotypic instability, and presence of 100% abnormal metaphases. A regression model including terms for blood and bone marrow features, and age at hospital admission was able to stratify patients into prognostic groups in the same population and in an independent population admitted prior to 1973. Further prospective testing of the model is required. Twenty-six of the 78 patients who were eventually treated with combination chemotherapy achieved complete remission. The presence of Auer rods, diagnosis of acute leukemia or refractory anemia with excess blasts, rapid increase in marrow infiltrate and favorable cytogenetic karyotype were associated with response. Delaying treatment in all patients was found to have improved only modestly the survival of patients with LIL.

Adolescent↗
PubMed1986

Therapy-related leukemia and myelodysplastic syndrome: clinical, cytogenetic, and prognostic features.

One hundred twelve patients who developed acute leukemia or a myelodysplastic syndrome (MDS) after chemotherapy or irradiation for another malignancy were reviewed. The median time from initial therapy to development of secondary leukemia or MDS was 71 months (range, 7 to 331 months). The initial malignancy was hematologic in 43%. An MDS presentation occurred in 57 patients (51%), 55% of whom subsequently transformed to acute leukemia. Chromosomal abnormalities were documented in marrow specimens from 70 of 89 patients with analyzable metaphases (79%; 69% of the total group). Compared with 34 patients with metachronous secondary leukemia without prior chemotherapy or irradiation, those with therapy-related leukemia exhibited a significantly higher frequency of abnormalities of chromosomes 5 and/or 7 (43% v 18%), and lower incidence of diploid karyotypes (18% v 50%). Chromosome 5 and/or 7 abnormalities were also significantly higher in patients previously treated with alkylating agents, procarbazine, and nitrosoureas (72% to 83%), compared with those who had received cyclophosphamide-based regimens (29%), other chemotherapies (14%), or irradiation alone (29%). The median overall survival from diagnosis of the secondary leukemia or MDS was 30 weeks. Survival was significantly shorter for patients with acute leukemia compared with MDS presentation (21 v 45 weeks); in the latter category, it was similar whether evolution to acute leukemia occurred or not. Of 72 patients treated with antileukemia therapy, 29% achieved complete remission (CR). A multivariate analysis of prognostic factors demonstrated the cytogenetic pattern to be the most important characteristic determining remission rate and survival. Other important prognostic features were the morphologic presentation (MDS v acute leukemia) for probability of achieving remission, and patient age and marrow blasts percentage for survival.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1986

High-dose cytosine arabinoside: treatment and cellular pharmacology of chronic myelogenous leukemia blast crisis.

Twenty-one patients with chronic myelogenous leukemia (CML) in blastic transformation underwent 22 remission induction attempts with high-dose cytosine arabinoside (ara-C), administered as a two-hour infusion of 3 g/m2 for six to 12 doses. Ara-C doses were administered every 12 hours in 15 patients and every six to ten hours in six patients. Median patient age was 35 years (range, 20 to 62). The median duration of benign phase was 25 months (range, 0 to 167). Morphology of blast crisis blast cells was myeloid in 15 patients and lymphoid in six. Five patients achieved complete remission (CR), three had partial remission (PR), and one had hematologic improvement, for an overall response rate of 41%. Median remission duration was 2.5 months (range, 0.5 to 6 months). Survival duration was 6 months for responding patients and 1.5 months for those with resistant disease. The response rate was similar for patients with myeloid and lymphoid blast crisis (31% v 50%, respectively). The response rate was significantly higher for patients whose benign phase was less than 1 year (75% v 21%, P = .05) and who had prolonged marrow aplasia after ara-C (86% v 27%, P = .05). Myelosuppression was the major dose-limiting toxicity, and cerebellar toxicity occurred in two patients. Intracellular ara-C 5'-triphosphate (ara-CTP) levels were similar in blood and bone marrow leukemic cells and were slightly greater in the cells of responding patients compared to those with resistant disease. We conclude that high-dose ara-C is an effective regimen for CML blast crisis, resulting in a substantial response rate but modest remission duration. Its combination with other agents may further improve the prognosis of patients with this resistant disease.

Adult↗