Characteristics of engraftment after repeated autologous bone marrow transplantation.

The rate of engraftment after autologous bone marrow transplantation (ABMT) is extremely variable and largely unpredictable. To identify factors influencing engraftment, we studied 35 patients with refractory germ cell tumors undergoing high-dose chemotherapy with carboplatin (900-2000 mg/m2) and etoposide (1200 mg/m2) with bone marrow rescue. Prior to the initiation of chemotherapy, bone marrow sufficient for two marrow infusions was harvested (range 0.86-4.82 x 10(8) nucleated cells per kg). All 35 patients received half of the collected bone marrow 3 days after the last dose of chemotherapy; 23 responders received a second round of the same chemotherapy followed by infusion of the second half of the bone marrow. Eighteen patients could be compared for the two transplant episodes. The "rate of engraftment" was defined as the unweighted mean of four parameters: 1) the number of days until the absolute granulocyte count surpassed 0.2 x 10(9)/liter, 2) the number of days until the absolute granulocyte count surpassed 0.5 x 10(9)/liter, 3) the number of days until the last platelet transfusion, and 4) the number of days until the reticulocyte count surpassed 25 x 10(9)/liter. No significant correlation was found between rate of engraftment and such factors as the number of nucleated cells per kg infused, the dose of chemotherapy, extent of prior chemotherapy, tumor response to the high-dose chemotherapy, age of the patient, or the days of granulocytopenic fever (all p greater than 0.20). In contrast, a close correlation was found for the number of units of platelets (p = 0.005) and red blood cells (p = 0.006) transfused following each of the two transplants. There was no significant difference between rate of engraftment after first and second transplantation. Comparison of these data with the results obtained in reported ABMT with separate harvests suggests that the characteristics of the infused marrow determine the rate of engraftment after ABMT. This model of repeated transplantation could provide an important tool for assessing the therapeutic efficacy of hematopoietic growth factors.

The effect of 17beta-estradiol-DNA adducts on the replication of exon # 5 of the human suppressor gene p53.

Using a PCR technique, exon # 5 of the human tumor suppressor gene p53 was amplified and ligated into the pCRII vector and transformed into Escherichia coli INV alphaF' competent cells. The cloned exon # 5 was 184 bp long. Evidence is presented to show that after dimethyldioxirane epoxidation, 17beta-estradiol was able to form 17beta-estradiol-DNA adducts and to strongly inhibit the replication of the cloned exon # 5 producing smaller sizes of DNA fragments and introducing errors of incorporation at the 3'-end of the terminating DNAs. The errors occurred mainly at the clusters of the complementary 'G' and 'A' bases on the template strand DNA, presumably, the major sites where the 17beta-estradiol-DNA adducts were formed.

Treatment of refractory lymphoma with high dose cytarabine, cyclophosphamide and either TBI or VP-16 followed by autologous bone marrow transplantation.

This study was designed to test the efficacy and toxicity of combining high-dose cytarabine (3 g/m2 every 12 h x 8 doses day -7 to day -4, total dose 24 g/m2), methyl prednisolone (0.5 mg/kg every 4 h day -7 to day -1), and cyclophosphamide (CY) (60 mg/kg day -3 and day -2) with either total body irradiation (TBI) (900 cGy in a single fraction on day -1) or VP-16 (600 mg/m2/days -7, -5, and -3) in patients not eligible for TBI secondary to prior radiotherapy. We treated 14 patients (eight male, six female) with either non-Hodgkin's lymphoma (n = 5) or Hodgkin's disease (n = 9). All patients had failed prior conventional chemotherapy (median two regimens range 1-5). Five patients were treated with TBI and nine with VP-16. There were eight complete remissions, two partial remissions, four were inevaluable for response due to early death. Overall survival is 21% (3/14) and relapse-free survival is 7% (1/14) with the sole disease-free survivor now 40 months from transplant. Very significantly, among patients receiving TBI, there were no survivors (median survival 24 days, range 17-330 days) and 4/5 had pulmonary complications. Median DLCO in these four patients was 61% (range 50-67) prior to transplant and none had an infectious etiology established by bronchoalveolar lavage. Median time to an absolute granulocyte count of 500 x 10(6)/l was 16 days (range 10-37 days) and to a platelet count of 20 x 10(9)/l was 12 days (range 7-22 days). In conclusion, the addition of high-dose cytarabine (24 g/m2) to CY and single-dose TBI or VP-16, while being very active, produced excessive pulmonary toxicity in this group of patients with lymphoma.

A new nonrandom chromosomal abnormality, t(2;16)(p11.2;p11.2), possibly associated with poor outcome in childhood acute lymphoblastic leukemia.

We report a new, nonrandom t(2;16)(p11.2;p11.2) in childhood acute lymphoblastic leukemia (ALL). Three of 292 patients with childhood ALL studied at Indiana University Medical Center had this translocation. All three had additional chromosomal abnormalities at diagnosis and were classified as having low hyperdiploidy (47-49 chromosomes) with structural abnormalities. The patients, two boys and one girl, ranged in age from 3 to 13 years. Peripheral white blood cells (WBC) counts ranged from 1.8 to 107.4 x 10(9)/L, all were classified as French-American-British (FAB) type L1, and all had B-lineage ALL. Because all three patients have relapsed after first remissions of 2 years 8 months to 6 years, the t(2;16) may indicate a poor prognosis and more aggressive treatment may be indicated for such patients. Because this translocation was the sole abnormality in one clone of patient 2 at relapse, it may be considered the primary abnormality. Therefore, it may also be the primary abnormality in the other two patients, and the genes involved in the breakpoints may be important in leukemogenesis.