The antitumor effect of combinations of the toxic proteins ricin and abrin with other drugs was studied in mice with systemic L1210 leukemia. Ricin was tested in combination with daunorubicin, c/s-dichlorodiammineplatinum(ll), or vincristine, and abrin was tested in combination with Adriamycin. The antileukemic effect of the regimens was gauged by assaying the life span of tumor-bearing animals...

Stimulation of unfractionated or nonadherent human marrow cells in agar culture by pokeweed-mitogen-stimulated BALB/c mouse spleen cell conditioned medium (SCM) led, in most cultures, to the exclusive formation of eosinophil colonies. The culture system exhibited linearity of eosinophil colony formation with varying numbers of cells cultured, and the absolute numbers and size of SCM-stimulated ...

Injection of testosterone, nortestosterone, or oxymetholone markedly enhanced granulopoietic recovery in mice made neutropenic by l,3-bis(2-chloroethyl)-l-nitrosourea, vinblastine, or cyclophosphamide. Blood neutrophils rose to six times normal counts, and the bone marrow showed sequential increases first in dividing granulocytic elements and later in the nondividing reserve. The steroid-induce...

Injection of testosterone, nortestosterone, or oxymetholone markedly enhanced granulopoietic recovery in mice made neutropenic by l,3-bis(2-chloroethyl)-l-nitrosourea, vinblastine, or cyclophosphamide. Blood neutrophils rose to six times normal counts, and the bone marrow showed sequential increases first in dividing granulocytic elements and later in the nondividing reserve. The steroid-induce...

Hematopoietin-1 (H-1) was purified from the human cell line 5637 and two amino acid sequences were observed in the preparation. One sequence was identical to that of interleukin 1 alpha (IL 1 alpha) and the other to that of IL 1 beta. The action of recombinant IL 1 alpha and other hematopoietic growth factors was studied using (a) a high proliferative potential colony-forming cell assay that us...

Intravenous (IV) administration of 5-fluorouracil (5-FU) caused severe hematopoietic injury in mice. Daily administration of purified human recombinant granulocyte colony-stimulating factor (rG-CSF) accelerated recovery from neutropenia in these injured mice. Granulocyte-macrophage progenitors (CFU-GM) in spleen were markedly increased by rG-CSF, while rG-CSF was less effective on the regenerat...

Innate response activator (IRA) B cells are a subset of B-1a derived B cells that produce the growth factors granulocyte macrophage colony stimulating factor and IL-3. In mouse models of sepsis and pneumonia, B-1a B cells residing in serosal sites recognize bacteria, migrate to the spleen or lung, and differentiate to IRA B cells that then contribute to the host response by amplifying inflammat...

We show that adrenergic agents modulate hematopoietic reconstitution after syngeneic bone marrow transplantation (BMT) in mice. Chemical sympathectomy by 6-hydroxydopamine (6-OHDA) significantly increased the number of peripheral blood leukocytes after syngeneic BMT. The alpha 1-adrenergic antagonist prazosin mimicked and extended the effect of 6-OHDA, with an additional rapid and significant i...

The graft versus host reactivity (GVHR) and hematopoietic stem cells of spleen cell inocula were assayed 3 days after pretreatment of donor mice with heated or unheated pertussis vaccine. Unheated vaccine reduced GVHR to 17 percent of control reactivity, measured by the Simonsen spleen weight assay, and increased 2. 2-fold the proportion of hematopoietic stem cells, assayed as colony forming un...