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Biomedical subjects

W I Bensinger

Publications and source records attributed to W I Bensinger.

At least 19 recordsLinked to original sources
PubMed1992

The ligand for c-kit, stem cell factor, stimulates the circulation of cells that engraft lethally irradiated baboons.

Recombinant human stem cell factor (SCF), the ligand for c-kit, has been shown to stimulate increased numbers of hematopoietic progenitor cells of multiple types to circulate in the blood of baboons, but it was not known if the cells stimulated to circulate by SCF contained cells capable of engrafting and rescuing lethally irradiated baboons. Peripheral blood mononuclear cells (PBMNC) were collected by leukapheresis from four untreated control baboons and from three baboons on the 10th or 11th day of treatment with SCF (200 micrograms/kg/d). All animals were transplanted with 1.00 to 1.04 x 10(8)/kg of cryopreserved autologous PBMNC after treatment with a single dose of 1,020 cGy total body irradiation (TBI). Three animals were transplanted with PBMNC that had been collected during SCF treatment, 24 to 38 days after the last dose of SCF. Rapid trilineage engraftment was documented by bone marrow biopsy in all three. The mean time to a total white blood cell count (WBC) > or = 500/microL, WBC > or = 1,000/microL, and an absolute neutrophil count (ANC) > or = 500/microL was 15 +/- 3 (mean +/- SD), 19 +/- 1, and 19 +/- 2 days, respectively. Two animals remain alive with stable engraftment more than 180 and 245 days posttransplant. The third died of sepsis 32 days posttransplant with a hypercellular marrow showing trilineage engraftment. The surviving animals were transfusion independent by 10 and 59 days posttransplant. Four control animals were transplanted with PBMNC collected in the absence of SCF stimulation. One was treated for 11 days with SCF (200 micrograms/kg/d) after PBMNC were collected. This animal was transplanted 25 days after the last dose of SCF. None of the four control animals engrafted and they died 13, 16, 28, and 38 days posttransplant with marrow aplasia. Treatment with SCF stimulates the circulation of cells that engraft and rescue lethally irradiated baboons. The characteristics of the transplantable cells present in the circulation are now amenable to direct study.

Animals↗
PubMed1992

Marrow transplantation following escalating doses of fractionated total body irradiation and cyclophosphamide--a phase I trial.

Thirty-six patients with advanced hematologic malignancy were entered into a Phase I study designed to define the maximum tolerated dose of unshielded total body irradiation delivered from dual 60 Cobalt sources at an exposure rate of 8 cGy/min and given in fractions twice daily for total doses ranging from 12 Gy to 17 Gy. All patients received cyclophosphamide, 120 mg/kg administered over 2 days before total body irradiation. Allogeneic marrow was infused from HLA-identical siblings (n = 29) or one locus HLA incompatible family members (n = 3); three patients received cryopreserved autologous marrow and one patient received syngeneic marrow. The maximum tolerated dose of total body irradiation given as 2 Gy fractions twice a day was 16 Gy. One of eight patients receiving 12 Gy, none of four receiving 14 Gy, three of 20 receiving 16 Gy, and two of four receiving 17 Gy developed severe (Grade 3-4) regimen-related toxicity. The primary dose limiting toxicity was pneumonitis, followed by veno-occlusive disease of the liver, renal impairment, and mucositis. Five patients (14%) are alive, four disease-free 798-1522 days posttransplant. Twenty (56%) relapsed posttransplant. Further investigation of regimens containing 16 Gy of hyperfractionated total body irradiation is warranted to assess anti-tumor efficacy.

Adolescent↗
PubMed1992

Supportive care in marrow transplantation.

Marrow transplantation is now an accepted form of therapy for patients with aplastic anemia, genetic diseases, and a variety of malignant diseases. Intensive chemotherapy and radiotherapy regimens are necessary to eradicate cancer cells and allow engraftment of the transplanted marrow. Patients undergoing such treatment suffer prolonged marrow aplasia and immunosuppression and experience significant nonmarrow toxicities. This requires maximum supportive care including hyperalimentation, fluid and blood transfusions, antibacterial and antiviral prophylaxis, and measures to reduce organ toxicities and accelerate engraftment. The use of drugs to suppress the production of antitumor necrosis factor-alpha has shown promise in reducing the nonmarrow toxicities of the conditioning regimen. Prophylactic antibiotics that reduce gastrointestinal colonization with aerobic bacteria yet preserve anaerobic flora may more effectively reduce not only systemic bacteria but fungal infections as well. The impact of infections due to cytomegalovirus has been reduced by more effective prevention in patients who are cytomegalovirus negative and reactivation in patients who are cytomegalovirus positive. The use of recombinant growth factors will significantly reduce morbidity after transplantation by reducing the period of marrow aplasia.

Adult↗
PubMed1992

Allogeneic marrow transplantation during untreated first relapse of acute myeloid leukemia.

PURPOSE: The purpose of this report was to review the Seattle experience in bone marrow transplantation (BMT) for acute myeloid leukemia (AML) during untreated first relapse. PATIENTS AND METHODS: Through 1990, 126 patients were transplanted during untreated first relapse of AML. Several preparative regimens were used, two of which involved more than 20 patients. Regimen 1 (29 patients) consisted of cyclophosphamide (CY) 120 mg/kg and 15.75 Gy of fractionated total-body irradiation (TBI) with methotrexate (MTX) given intermittently during a 102-day period to prevent graft-versus-host disease (GVHD). Regimen 2 (22 patients) consisted of the same CY and TBI treatment and a combination of MTX and cyclosporine (CSP) for GVHD prophylaxis. The remaining 75 patients were treated with 17 other transplant regimens. Outcome was compared for patients who were treated with regimen 1, regimen 2, and any other regimen. RESULTS: The 5-year probabilities of relapse-free survival (RFS), relapse, and nonrelapse mortality for 126 patients were .23, .57, and .44, respectively. With regimen 1, relapse (.26) was significantly less than for regimen 2 (.70; P = .004) or any other regimen (.76; P = .004). Regimen 1 patients developed more acute GVHD (.67) than regimen 2 patients (.26; P = .02) or patients on other regimens (.41; P = .02), and had increased nonrelapse mortality. Nevertheless, regimen 1 patients had a significantly higher 3-year RFS (.38) than those treated with regimen 2 (.18; P = .04) or any other regimen (.20; P = .05). CONCLUSIONS: For patients who received 120 mg/kg CY and 15.75 Gy TBI, relapse incidence was less and survival was better after GVHD prophylaxis with MTX alone than after a combination of MTX and CSP, despite a significantly higher incidence of acute GVHD. The results of treatment with regimen 1 justify future studies of the optimal timing of allogeneic BMT in the treatment of patients with AML.

Acute Disease↗
PubMed1992

Phase I study of busulfan and cyclophosphamide in preparation for allogeneic marrow transplant for patients with multiple myeloma.

PURPOSE: To study the toxicity and potential efficacy of busulfan (BU) and cyclophosphamide (CY) as a conditioning regimen before allogeneic bone marrow transplantation (ABMT) in patients with multiple myeloma (MM). PATIENTS AND METHODS: Twenty patients with MM underwent conditioning, which was followed by ABMT from 16 HLA-identical donors, three one-antigen-mismatched donors, and one HLA A, B, D-identical unrelated donor. Four levels of BU plus CY were evaluated. RESULTS: Severe regimen-related toxicity occurred in two of five patients who received BU 16 mg/kg and CY 120 mg/kg, in none of the four patients who received BU 14 mg/kg and CY 120 mg/kg, in one of eight patients who received BU 14 mg/kg and CY 147 mg/kg, and in two of three patients who received BU 14 mg/kg and CY 174 mg/kg. Twelve of 15 (80%) assessable patients achieved a complete remission with the disappearance of M-protein and the return of normal marrow morphology. Ten patients died of complications related to the ABMT, and two patients died of progressive or relapsed MM. Overall, eight of 20 patients were alive; seven (35%) were in complete remission 190 to 1,271 days after ABMT. CONCLUSIONS: The maximum-tolerable dose given in this setting was BU 14 mg/kg and CY 147 kg/mg. These results suggest that this regimen may have significant antimyeloma activity. Further phase II studies are warranted.

Adult↗
PubMed1992

Etoposide, cyclophosphamide and fractionated total body irradiation as a preparative regimen for marrow transplantation in patients with advanced hematological malignancies: a phase I study.

Thirty-seven patients with advanced hematologic malignancy were entered into a phase I study designed to define a maximum tolerable dose (MTD) of etoposide (VP-16) and cyclophosphamide (CY) combined with 12 Gy fractionated total body irradiation (TBI) as preparation for marrow transplantation from an HLA-identical sibling (n = 13) or with cryopreserved autologous marrow (n = 24). Dose levels ranged from 36 mg/kg of VP-16 combined with 67 mg/kg of CY to 52 mg/kg of VP-16 combined with 103 mg/kg of CY followed by 12 Gy TBI. The MTD for allogeneic marrow recipients was 36 mg/kg of VP-16 + 52 mg/kg of CY followed by 12 Gy TBI and for autologous marrow recipients 44 mg/kg of VP-16 + 103 mg/kg CY followed by 12 Gy TBI. Pulmonary and liver toxicities were dose limiting. All of 31 evaluable patients transplanted in relapse achieved a complete remission. However, in all but three of these patients the disease relapsed 28-899 (median 110) days post-transplant. Currently, six of 24 autologous marrow recipients are surviving, three in remission 256, 340 and 764 days post-transplant. None of 12 allogeneic marrow recipients have survived. In conclusion, a preparative regimen combining 44 mg/kg of VP-16 + 103 mg/kg CY followed by 12 Gy TBI is well tolerated by autologous marrow recipients and 36 mg/kg VP-16 + 67 mg/kg CY followed by 12 Gy TBI is well tolerated by allogeneic marrow recipients.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1992

Differential effect of the combination methotrexate/(dl)-5-methyltetrahydrofolate on lymphoid malignant and normal bone marrow cells.

It has been reported that high doses of (dl)-5-methyltetrahydrofolate (mTHF) inhibit the growth of leukemic cell lines. We studied the effect of methotrexate (MTX) and mTHF in combination on the lymphoid cell lines BALM 3, CEM, MOLT 4 and P3HR1 by evaluating the clonogenic cell reduction in a limiting dilution assay. Cells were treated with 0.1 mM MTX for 4 h and 1 mM mTHF for 48 h. The growth of the cell lines was inhibited by 1 mM mTHF, with a clonogenic cell reduction of 3.5 log. MTX, following by mTHF after a delay of 8-24 h, caused a substantial killing of lymphoid leukemia cells, greater than the effect of either drug alone. The clonogenic cell reduction caused by the combination MTX-mTHF ranged from about 3.5 to 4.5 log, depending on the cell line studied. Normal hemopoiesis, as evaluated by primitive hematopoietic precursor colonies and granulocyte-macrophage colony-forming units (CFU-GM) was only slightly affected by the MTX-mTHF treatment at a dose and schedule which caused up to 4.5 log reduction of the leukemic cell lines. mTHF-MTX treatment could be useful in vitro for purging bone marrow cells in autologous bone marrow transplantation for acute leukemia.

Bone Marrow↗
PubMed1991

Identification of alloimmunized patients: use of radiolabeled allogeneic platelet kinetic measurements and platelet antibody tests.

In a group of stable, nonthrombocytopenic leukemia patients awaiting bone marrow transplantation, results of paired allogeneic radiolabeled platelet kinetic measurements were correlated with the results of several different platelet and lymphocytotoxic antibody tests to determine which parameters could be used to identify patients who were alloimmunized to platelets. Seven patients with acute leukemia who had been transfused during induction therapy were used as the test group, and, as a control group, five untransfused patients with chronic myelogenous leukemia were also studied. Concurrent fibrinogen survival measurements were performed in all patients to assess whether hemostatic factor consumption (ie, disseminated intravascular coagulation) was present. Allogeneic platelet survival measurements were reduced from normal in all 12 study patients. In 8 of 12 patients, fibrinogen and platelet survival measurements were comparably reduced, suggesting disease-related platelet consumption. In four heavily transfused patients with acute leukemia, allogeneic platelet survivals were markedly reduced to less than or equal to 2.1 days, compared with the 3.5- to 7.4-day platelet survival measurements found in the other eight patients. The disproportionately short platelet survivals compared with fibrinogen survival measurements in these four patients, combined with documented positive antibody tests to their donors' platelets in the three patients with evaluable tests, suggested that these patients had become alloimmunized to platelets because of their prior transfusions. There was substantial concordance between the two radiolabeled allogeneic donor platelet survival measurements performed in each of these patients, suggesting that host rather than donor factors have a major influence on transfusion outcome (r = .93, P less than .001). The platelet cross-match tests, using the radiolabeled protein Staph A assay combined with the IgG enzyme-linked immunosorbent assay test, had the best correlation with the posttransfusion recovery and survival of the donors' platelets.

ABO Blood-Group System↗
PubMed1991

Engraftment after infusion of CD34+ marrow cells in patients with breast cancer or neuroblastoma.

The CD34 antigen is expressed by 1% to 4% of human and baboon marrow cells, including virtually all hematopoietic progenitors detectable by in vitro assays. Previous work from our laboratory has shown that CD34+ marrow cells can engraft lethally irradiated baboons. Because the CD34 antigen has not been detected on most solid tumors, positive selection of CD34+ cells may be used to provide marrow cells capable of engraftment, but depleted of tumor cells. In seven patients with stage IV breast cancer and two patients with stage IV neuroblastoma, 2.5 to 17.5 x 10(9) marrow cells were separated by immunoadsorption with the anti-CD34 antibody 12-8 and 50 to 260 x 10(6) positively selected cells were recovered that were 64 +/- 16% (range 35% to 92%) CD34+. The patients received 1.0 to 5.2 x 10(6) CD34-enriched cells/kg after marrow ablative therapy. Six patients engrafted, achieving granulocyte counts of greater than 500/mm3 at 34 +/- 10 (range 21 to 47) days and platelets counts of greater than 20,000/mm3 at 46 +/- 14 (range 28 to 66) days posttransplant. Five of these patients showed durable engraftment until the time of death 82 to 386 days posttransplant. One patient failed to sustain engraftment associated with metastatic marrow disease. Three patients died at days 14, 14, and 17 posttransplant, two of whom had evidence of early engraftment. These studies suggest that CD34+ marrow cells are capable of reconstituting hematopoiesis in humans.

Antigens, CD↗
PubMed1991

Allogeneic marrow transplantation in patients with chronic myeloid leukemia in the chronic phase: a randomized trial of two irradiation regimens.

A randomized trial was performed to compare two regimens of total body irradiation in patients with chronic myeloid leukemia treated by allogeneic marrow transplantation while in the chronic phase. All patients received cyclophosphamide 120 mg/kg followed by total body irradiation and marrow from HLA-identical siblings. Cyclosporine and methotrexate were used for prophylaxis against acute graft-versus-host disease. Fifty-seven patients were randomized to receive 2.0 Gy fractions of irradiation daily for 6 days and 59 were randomized to receive 2.25 Gy fractions daily for 7 days. The probabilities of relapse at 4 years were 0.25 for the 12.0 Gy group and 0.00 for the 15.75 Gy group (P = .008). The actuarial probabilities of survival and relapse-free survival at 4 years were 0.60 and 0.58 among the patients who received 12.0 Gy compared with 0.66 and 0.66 for those who received 15.75 Gy. The 4-year probabilities of transplant-related mortality were 0.24 and 0.34 respectively (P = .13) while the probability of moderate to severe acute graft-versus-host disease was 0.33 for the 12.0 Gy group and 0.44 for the 15.75 Gy group (P = .15). The lower relapse probability in the patients receiving the higher dose of total body irradiation did not result in improved survival because mortality from causes other than relapse was increased.

Adult↗
PubMed1991

Effect of (dl)-5-methyltetrahydrofolate on lymphoid leukemia cell lines.

We studied the effect of (dl)-5-methyltetrahydrofolate (mTHF) on the lymphoid cell lines BALM 3, CCRF-SB, CEM, Daudi, MOLT 4 and P3HR1, employing doses in the mM range. The growth of all the lines studied was inhibited by mTHF in a dose-dependent fashion. mTHF demonstrated a substantial cytocidal effect on leukemic lymphoid cells of up to 3 log, as measured by limiting dilution analysis, at a concentration of 10(-3) M. At this dose normal human lymphocyte viability was not affected, and their mitogen-induced proliferation was only slightly impaired. We tested the effect of high doses of mTHF on a clone of CEM cells (CEM-MTXr) infected with the pSDHT retrovirus able to transduce a dominant-acting gene encoding a mutant, less efficient, dihydrofolate reductase. CEM-MTXr cells were inhibited by high doses of mTHF to the same degree as the parental line, thus suggesting that the enzymatic reactions leading to folate reduction are not involved in the cytocidal effect of mTHF.

Cell Cycle↗
PubMed1990

Allogeneic marrow transplantation in patients with acute myeloid leukemia in first remission: a randomized trial of two irradiation regimens.

A randomized trial of 12.0 Gy versus 15.75 Gy of total body irradiation (TBI) was performed in patients with acute myeloid leukemia undergoing allogeneic marrow transplantation while in first complete remission. All patients received 120 mg/kg cyclophosphamide followed by TBI and marrow from HLA-identical siblings. Cyclosporine and methotrexate were used for prophylaxis against acute graft-versus-host disease (GVHD). Thirty-four patients received 2.0-Gy fractions of irradiation daily for 6 days and 37 received 2.25-Gy fractions daily for 7 days. The 3-year actuarial probabilities for relapse-free survival were 0.58 for the patients who received 12.0 Gy and 0.59 for those who received 15.75 Gy. The 3-year probabilities of relapse were 0.35 for the 12.0 Gy group and 0.12 for the 15.75 Gy group (P = .06). The 3-year probabilities of transplant-related mortality were 0.12 and 0.32, respectively (P = .04). The probability of moderate to severe acute GVHD was 0.21 for the 12.0 Gy group and 0.48 for the 15.75 Gy group (P = .02). Patients exposed to the higher irradiation dose received less immunoprophylaxis against, and had a higher incidence of, acute GVHD. The increased dose of TBI significantly reduced the probability of relapse but did not improve survival because of increased mortality from causes other than relapse.

Adolescent↗
PubMed1990

Autologous marrow transplantation for malignant lymphoma: a report of 101 cases from Seattle.

Between October 1979 and January 1988, 101 patients with malignant lymphoma who failed initial induction treatment or relapsed received high-dose combination chemotherapy or chemoradiotherapy followed by infusion of autologous bone marrow. Twenty-eight of the 101 patients survive, 18 of whom are disease-free for a median of 26 (range, 12 to 66) months. The 5-year actuarial probabilities of survival, event-free survival (EFS), and relapse from transplantation were 20%, 11%, and 84%, respectively. Multivariate analysis showed that the likelihood of EFS was decreased among patients transplanted with a Karnofsky score of less than 80%. Recurrent lymphoma after transplant was the most important cause of treatment failure with 36 of 62 relapses occurring within 100 days from marrow infusion. Early, but not late relapse, was more frequent in patients transplanted for advanced lymphoma, and both early and late relapses were increased among patients with impaired pretransplant clinical performance or high-grade histology of lymphoma. Ten patients who relapsed post-transplant are alive, seven in remission. Further improvement of these results will require earlier transplantation, improved preparative regimens, or early posttransplant therapy.

Adolescent↗
PubMed1990

Stem cell selection--clinical experience.

The ability to isolate large numbers of hematopoietic progenitors will facilitate an understanding of the growth and differentiation of bone marrow. Furthermore, isolating hematopoietic progenitors will have widespread clinical applications to autologous marrow transplantation, allogeneic marrow transplantation, gene therapy, and in vitro marrow expansion. With the development of avidin-biotin immunoadsorption, it is now feasible to isolate large numbers of these progenitor cells for clinical purposes. Successful hematopoietic reconstitution has been demonstrated in lethally irradiated baboons transplanted with CD34+ cells isolated by immunoadsorption with the anti-CD34 antibody 12-8. Recent studies have shown that CD34+ cells enriched from the marrow of patients with metastatic breast cancer can be used for autologous marrow transplantation.

Animals↗
PubMed1990

Positive selection of hematopoietic progenitors from marrow and peripheral blood for transplantation.

The ability to obtain large numbers of purified hematopoietic progenitors (HPC) will facilitate the understanding of elements that influence the growth and differentiation of bone marrow. Furthermore, HPC isolation will have direct application to autologous marrow transplantation (AMT) for malignancies as well as facilitate the transfer of genes in marrow cells for the correction of genetic disorders. The transplantation of HPC will help delineate the cells or factors responsible for graft rejection and graft-versus-host-disease. Or several techniques that have been utilized for the separation of HPC, only the avidin-biotin immunoadsorption (ABIA) method has been shown capable of separating the number of cells required for large animals and man. The application of this technique to AMT in man requires the identification of an antigen found predominantly on HPC in peripheral blood or marrow but not on malignant cells that could potentially contaminate bone marrow. Studies have demonstrated that the CD34 antigen is expressed by the majority of human marrow HPC measured in long-term marrow culture and is expressed on cells capable of autologous engraftment in lethally irradiated baboons. Although the CD34 antigen is not detectable by FACS analysis on peripheral blood cells, ABIA can enrich for such cells. The CD34 antigen is not detected on cells from patients with breast cancer or neuroblastoma thus allowing clinical studies to proceed. Preliminary results suggest that CD34(+)-enriched cells are depleted of tumor cells and are capable of autologous reconstitution in man.

Antigens, CD↗
PubMed1989

Marrow transplantation for malignant plasma cell disorders: summary of the Seattle experience.

28 patients with plasma cell malignancies received marrow transplants from identical twins (N = 8), HLA-identical family members (N = 15), HLA partially-matched relatives (N = 3) or cryopreserved autologous marrow (N = 2). Treatment regimens included cyclophosphamide (CY) and total body irradiation (TBI) for 15 patients and busulphan (BU) and CY for 13 patients. 3 of 8 twins are alive, 2 without disease at 24 and 34 months, and 1 is alive and well at 116 months without evidence of disease except for at small residual monoclonal protein spike. 12 of the 18 allografted patients died of transplant-related causes and 2 died of progressive disease. 4 of 18 allograft recipients are alive; 2 are free of disease at 16 and 15 months, 1 is alive at 6 months without disease except for persistent monoclonal Kappa protein. 1 patient is alive with residual marrow involvement and a persistent IGA lambda monoclonal protein at 7 months. 1 of the 2 autograft recipients is alive 2 months after transplant and is not yet evaluable for tumor response and the other patient died early of transplant-related complications. Both CY + TBI and BU + CY resulted in remissions in patients with advanced plasma cell malignancies. However, the optimal treatment regimen and timing of transplantation remain to be determined.

Antineoplastic Combined Chemotherapy Protocols↗