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Biomedical subjects

M A Cheever

Publications and source records attributed to M A Cheever.

107 records · Page 6Linked to original sources
PubMed1981

Treatment of non-Hodgkin's lymphoma with marrow transplantation in identical twins.

Eight patients with disseminated non-Hodgkin's lymphoma who failed conventional combination chemotherapy were treated with high-dose chemotherapy, a supralethal dose of total-body irradiation, and a bone marrow transplant from a normal identical twin. Seven patients experienced complete remission. Four of the seven patients (two with diffuse poorly differentiated lymphocytic lymphoma, one with composite lymphoma, and one with diffuse moderately well differentiated lymphocytic lymphoma) remain in complete unmaintained remission 12-126 mo from transplantation. One patient relapsed after 10 mo but was retreated and is alive in unmaintained complete remission 73 mo from transplantation. One patient died of Pseudomonas pneumonia while in complete remission and one patient relapsed and died of progressive lymphoma. These results demonstrate that intensive chemoradiotherapy and twin marrow transplantation can induce frequent and enduring remissions in patients with disseminated non-Hodgkin's lymphoma who have failed conventional therapy.

Adolescent↗
PubMed1980

Specificity of adoptive chemoimmunotherapy of established syngeneic tumors.

To examine the specificity of adoptive chemoimmunotherapy (ACIT) of established syngeneic tumors, two noncross-reactive C57BL/6 tumors were studied: a Friend virus-induced tumor (FBL-3) and a chemically induced virus-negative tumor EL-4(G-). In vitro studies confirmed that these tumors are antigenically distinct by demonstrating that the cytotoxic responses of spleen cells from mice immunized in vivo and reexposed to tumor in vitro are immunologically specific. Studies of ACIT with cells from mice immunized in vivo demonstrated similar specificity. Mice receiving 5 x 10(6) FBL-3 on day 0 all died by day 13. Treatment on day 5 with cyclophosphamide (CY), 180 mg/kg, prolonged the median survival time (MST) to day 23. Treatment on day 5 with CY plus 2 x 10(7) normal nonimmune C57BL/6 cells or CY plus cells sensitized to EL-4(G-) had no additional effect on survival whereas 2 x 10(7) C57BL/6 cells sensitized to FBL-3 in vivo prolonged MST to day 64 and cured 13 of 32 mice. Similarly, mice given 2 x 10(5) EL-4(G-) on day 0 all died by day 16, and CY on day 5 prolonged the MST to day 22. As an adjunct to CY, 2 X 10(7) normal cells or cells sensitized to FBL-3 had a modest effect, prolonging the MST to days 37 and 36, respectively. However, treatment with CY plus 2 x 10(7) cells immune to EL-4(G-) cured 22 of 32 mice. The results demonstrate the immunologic specificity of ACIT of syngeneic tumors treated with immune syngeneic cells.

Animals↗
PubMed1980

Therapy of leukemia by nonimmune syngeneic spleen cells.

In previous studies mice bearing an established transplanted syngeneic leukemia were cured by the adoptive transfer of immune lymphoid cells inoculated as an adjunct to chemotherapy, whereas nonimmune cells had no effect. By employing a smaller initial tumor inoculum to enhance the sensitivity of the chemoimmunotherapy model, the current study demonstrated that cells from normal nonimmune donors can also eradicate tumor. Thus, adult BALB/c mice given a lethal dose (1 x 10(4)) of LSTRA on day 0 were treated on day 5 with cyclophosphamide (CY) alone or CY plus nonimmune cells. Untreated mice all died by day 10. Cy alone prolonged median survival time (MST) to day 20, but all mice died. Treatment with CY plus 1 x 10(7) nonimmune cells prolonged the MST to day 26 and cured 16 of 48 mice. The effector cells, present in the spleens of normal and nude mice, were nonadherent lymphocytes resistant to anti Thy + C. These results are consistent with this effector cell in adoptive chemoimmunotherapy being an NK cell. However, they are distinct from classical NK cells since they are not directly cytotoxic in vitro in a short term CRA and do not neutralize tumor in vivo in a Winn assay.

Animals↗
PubMed1980

Detection of early and delayed antitumor effects following curative adoptive chemoimmunotherapy of established leukemia.

Advanced disseminated leukemia can be successfully eradicated by treatment with a combination of noncurative nonlethal chemotherapy plus adoptively transferred immune cells. The time course of tumor elimination following such therapy was examined by bioassay for tumor of peripheral blood and spleen cells from treated mice. Curative treatment with adoptive chemoimmunotherapy did not immediately eliminate all leukemia. Bioassay of cells from treated mice, rather, demonstrated that, following the initial tumor lysis mediated by the chemotherapy and immune cells, a period of tumor regrowth lasting several weeks preceded ultimate tumor eradication. This transient tumor regrowth detectable by bioassay never became clinically evident in the treated mice. However, immunosuppression of mice two weeks after treatment with adoptive chemoimmunotherapy resulted in recurrence of lethal tumor. The results suggest that tumor elimination following curative adoptive chemoimmunotherapy is biphasic and that the efficacy of therapy may be subject to positive and/or negative influences over a prolonged time period.

Animals↗
PubMed1979

Disappearance of Ph1-positive cells in four patients with chronic granulocytic leukemia after chemotherapy, irradiation and marrow transplantation from an identical twin.

Four patients (21, 41, 13 and 38 years of age) with a history of chronic granulocytic leukemia for 12, 10, 11, and 106 months, respectively, were treated with dimethyl busulfan, cyclophosphamide, 920 rads of total-body irradiation and intravenous marrow infusion from normal, genetically identical twins. Serial chromosome analyses were performed on marrow aspirates cultured without mitotic stimulants. No Ph1-positive cells were detected in the marrows from the normal twins, whereas just before therapy, all 100 metaphases examined from each patient were Ph1-positive. Chromosome analyses were performed three to five times per patient after transplantation, and not a single Ph1-positive cell was detected. The patients remain hematologically normal 22, 23, 26 and 31 months after transplantation. The results show that the Ph1-positive clone can be eradicated by vigorous therapy and that the marrow in chronic granulocytic leukemia can be repopulated by stem cells from normal twins.

Adult↗
PubMed1977

Reduction of fatal graft-versus-host disease by 3H-thymidine suicide of donor cells cultured with host cells.

The effect of the tritiated thymidine (3H-TdR) suicide technique on the ability of donor cells to induce fatal graft-versus-host disease (GVHD) was studied. C57BL/6 (H-2b) spleen cells were stimulated in vitro with irradiated BALB/c (H-2d) Moloney lymphoma cells in mixed culture and 3H-TdR of high-specific activity added to eliminate proliferating cells. The ability of such cells to induce fatal GVHD was assayed by injecting them i.v. into adult BALB/c mice immunosuppressed with cyclophosphamide (180 mg/kg). These cells induced fatal GVHD in fewer mice (52 per cent) than did C57BL/6 cells cultures with BALB/C lymphoma cells but without 3H-TdR (87%) and C57BL/L cells cultured with irradiated C57BL/6 cells with (95 per cent) or without 3H-TdR (86 per cent). Thus, the 3H-TdR suicide technique greatly diminished the ability of cells to induce lethal GVHD.

Animals↗
PubMed1976

Use of dimethylmyleran in adoptive chemoimmunotherapy of two murine leukemias.

Dimethylmyleran (DMM) is an antitumor agent that has minimal effects on immunity. In a study of its usefulness in adoptive chemoimmunotherapy, C57BL/6 mice inoculated on day 0 with C57BL/6 Friend virus-induced leukemia (FBL-3) were treated on day 5 with 12 mg DMM/kg [less than LD10 (lethal dose for 10% of mice)] plus C5BL/6 spleen cells. All untreated mice died, with a median survival time (MST) of 17 days. DMM alone or with nonimmune cells prolonged survival to day 20, and 3/53 mice survived beyond day 60. By contrast, 12/25 mice treated with DMM plus cells immune to FBL-3 were cured. Similar results were obtained in C57BL/6 mice with syngeneic Rauscher virus-induced leukemia (RBL-5). Untreated mice died, with an MST of 14 days. DMM alone or with nonimmune cells prolonged the MST to 21 and 26 days, respectively, and 3/26 and 6/28 mice were long-term survivors. However, 13/28 mice were cured by DMM plus cells immune to antigenically related FBL-3. Lethal irradiation of cells immune to FBL-3 abolished their efficacy. Finally, in contrast to the efficacy of sublethal DMM plus immune cells, an LD100 of DMM (20 mg/kg) plus hematopoietic reconstitution with nonimmune syngeneic cells was not effective against FBL-3 OR RBL-5. The results emphasized the critical role of immune cells in chemoimmunotherapy even when the drug used is nonimmunosuppressive.

Animals↗
PubMed1976

Induction of increased graft-versus-host disease by mouse spleen cells sensitized in vitro to allogeneic tumor.

The aim of our study was to sensitize cells in vitro, follow their proliferative and cytotoxic responses, and determine their ability to cause lethal graft-versus-host disease (GVHD). C57BL/6 (H2b) spleen cells were incubated with irradiated BALB/C (H2d) Moloney lymphoma cells (LSTRA) in mixed leukocyte culture conditions for 2, 4, or 6 days and then tested. The maximal proliferative response occurred after 4 days. In vitro cytotoxic reactivity against 51Cr-labeled LSTRA was generated by 4 days (76.3+/-3.1% 51Cr released) and 6 days (133.0+/-4.8%) of sensitization but not by 2 days (-0.2+/-1.1%). Induction of fatal GVHD was assayed by injecting graded doses of the C57BL/6 spleen cells i.v. into adult BALB/c mice pretreated with cyclophosphamide, 180 mg/kg. Cells sensitized for 2 days were effective but no more so than were (control) cells cultured with irradiated C57BL/6 spleen cells. However, cells sensitized longer were far more active than the control cells. Cells sensitized for 4 days killed 70 of 88 mice (80%), and those sensitized for 6 days killed 37 of 48 mice (77%), whereas control cells killed only 42 of 90 mice (47%) (P less than 0.005). Thus, cells sensitized in vitro exhibited an increased ability to induce GVHD in vivo, which was temporally associated with the development of cytotoxicity in vitro.

Animals↗
PubMedDate not supplied

Combination chemotherapy for acute nonlymphoblastic leukemia in adults.

Between January 1973 and February 1975, 77 adults with acute nonlymphoblastic leukemia were treated with a combination of daunorubicin, cytosine arabinoside, 6-thioguanine, prednisone, and vincristine in university-affiliated and private institutions. After 31 patients were treated (regimen 1) the doses of all drugs were significantly increased (regimen 2). Regimes 1 and 2 yielded CR rates of 59% (17 of 29 patients) and 70% (32 of 46 patients) respectively. With regimens 2 the mean number of courses and the median number of days to CR decreased from 3 to 1.4 and from 46 to 29 respectively. Failure to achieve CR was due to persistent leukemia during regimen 1 and fatal infections during regimen 2. With regimen 2 ten of 20 patients (50%) greater than 50 years had CR compared to 22 of 26 patients (85%) less than 50 years. CR rates were similar in community and university institutions.

Adolescent↗