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Biomedical subjects

A B Einstein

Publications and source records attributed to A B Einstein.

35 records · Page 2Linked to original sources
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↗
PubMed1975

Effect of dimethylmyleran on cell-mediated immunity to a tumor allograft.

C57BL/6 mice (H-2b) were inoculated on day 0 with killed Moloney lymphoma cells (LSTRA) of BALB/c origin (H-2d), and their spleen cells were tested for reactivity against LSTRA by the 51Cr-release cytotoxicity assay. Cytotoxic reactivity of cells from ice not treated with drug was maximal by day 6 and disappeared by day 10. Cells from mice given dimethylmyleran (DDM) (12 or 16 mg/kg) on day -1 showed higher levels of cytotoxicity, whereas DMM administered on day +1 had little effect. The effect of DMM on the secondary response was tested and compared with that of cyclophosphamide (CY), 180 mg/kg. Cytotoxicity of cells from mice immunized on days 0 and 10 was maximal on day 15 and then declined. CY administered on day 11 prevented the development of any cytotoxicity and, when given on day 14 in the presence of a detectably strong secondary cytotoxic response, abolished the established response. In contrast, DMM given on day 11 delayed the onset and moderately decreased the peaks of secondary reactivity but had no effect when administered on day 14. These results showed that DMM enhanced a primary response, interfered somewhat with the development of a secondary response, and had no effect on an established secondary cell-mediated response to a tumor allograft. DMM thus was one of the rare agents with antitumor activity and little immunosuppressive action.

Animals↗
PubMed1975

Suppression of secondary cellular immunity to a tumor allograft by cyclophosphamide and 1,3-bis(2-chloroethyl)-1-nitrosourea.

C57BL/6 mice (H-2b) were immunized with lethally x-irradiated Moloney virus-induced lymphoma cells of BALB/c origin (H-2d) on Days 0 and 10 and received rug on Days 11 and 14. Their spleen cells were then tested for reactivity against Moloney virus-induced lymphoma of BALB/c origin by the 51Cr-release cytotoxicity assay. In non-drug-treated mice the secondary cytotoxic response was maximal on Days 14 to 15, declined rapidley, and recurred after Day 21. The cytotoxic effector cells were shown to be theta-bearing T-lymphocytes. Cyclophosphamide (CY), 180 mg/kg, given on Day 11, totally prevented the development of a cytotoxic response and when given on Day 14 abolished the response already established. CY, 48 mg/kg, as well as 1,3-bis(2-chloroethyl)-1-nitrosourea 33 mg/kg, were almost as suppressive. Immune mice given CY on Day 14 and reimmunized on Day 36 exhibited a normal tertiary response. Mice similarly immunized on Days 1 and 10 and given drugs on Day 14 were challenged on Day 15 with up to 3.5 x 10-8 viable Moloney virus-induced lymphoma cells of BALB/c origin. Despite H-2 incompatibility, all nonimmune control mice developed ascites and died, whereas all mice immunized but not given drug failed to develop ascites. By contrast, 17 of 34 immunized mice given CY, 180 mg/kg, and 7 of 34 given 1,3-bis(2-chloroethyl)-1-nitrosourea developed ascites. The ascites eventually regressed. THE RESULTS SHOW THAT CY and 1,3-bis(2-chloroethyl)-1-nitrosourea can suppress a secondary cellular immune response as measured by the T-cell-mediated 51Cr-release cytotoxicity assay in vitro and by viable tumor challenge in vivo.

Animals↗
PubMed1975

Syngeneic adoptive immunotherapy and chemoimmunotherapy of a Friend leukemia: requirement for T cells.

The aim of the study was to determine which cell mediates adoptive immunotherapy and chemoimmunotherapy of a syngeneic transplantable Friend virus-induced leukemia (FBL-3). An adoptive immunotherapy model was developed in which adult C57BL/6 mice given a lethal dose (10(4)) of FBL-3 on day 0 were saved by treatment on day 1 with C57BL/6 spleen cells or peritoneal exudate cells (PEC) immune to FBL-3. Cells passed through a nylon wool column to remove B cells and macrophages or treated with carbonyl iron to remove phagocytic cells remained effective, whereas cells treated with anti-theta serum and complement were far less effective. For adoptive chemoimmunotherapy, mice inoculated with 10(7) FBL-3 were treated 5 days later with cyclophosphamide (CY) plus immune spleen cells. CY, with or without non-immune cells, prolonged survival but all mice died with leukemia, whereas mice given CY plus immune cells survived tumor-free. As an adjunct to CY, immune cells passed through nylon wool or treated with carbonyl iron remained quite effective whereas cells treated with anti-theta serum and complement were far less effective. Thus, immune thymus-derived lymphocytes were required for the adoptive immunotherapy of an early leukemia or chemoimmunotherapy of a disseminated leukemia.

Animals↗
PubMed1975

Peroxidase-H2O2-halide system: Cytotoxic effect on mammalian tumor cells.

Myeloperoxidase, H2O2, and a halide constitute a potent antimicrobial system. A cytotoxic effect of this system on a line of mouse ascitic lymphoma cells (LSTRA) is demonstrated here using four different assay systems: 51Cr release, trypan blue exclusion, inhibition of glucose C-1 oxidation, and loss of oncogenicity for mice. Deletion of each component of the system, preheating the peroxidase, or addition of azide, cyanide, or catalase abolished the cytotoxicity. Myeloperoxidase was effective with either chloride or iodide as the halide, while lastoperoxidase was effective with iodide but not chloride. The iodinated thyroid hormones, triiodothyronine and thyroxine, could substitute for the halide, and H2O2 could be replaced by a peroxide-generating enzyme system such as glucose and glucose oxidase or by H2O2 producing bacteria such as pneumococci or streptococci. The possibility is raised that the peroxidases of inflammatory cells and certain biologic fluids may affect tumor initiation or growth in vivo.

Animals↗
PubMed1972

Sialic acids on the plasma membrane of cultured human lymphoid cells. Chemical aspects and biosynthesis.

From 61 to 92% of the total sialic acid of a variety of human lymphoid cell lines maintained in tissue culture is present on the cell surface as measured by its susceptibility to cleavage by Clostridium perfringens neuraminidase. These cells contain from 1.22 x 10(8) to 6.99 x 10(8) molecules of surface sialic acid per cell. In synchronized cultures synthesis of surface sialic acid occurs only during a limited time in the late G(2) phase of the cell cycle. The amount and density of surface sialic acid vary considerably throughout the cell cycle.

Burkitt Lymphoma↗
PubMedDate not supplied

Autologous red blood cell and platelet engulfment in hairy cell leukemia.

Seven cases of hairy cell leukemia (leukemic reticulo-endotheliosis) are presented in which peripheral blood or splenic hairy cells or both were identified engulfing autologous red blood cells or platelets. In 3 patients, approximately 5-15% of their peripheral blood hairy cells were engulfing red cells and platelets. In 2 patients, intercellular junctions were present between processes of hairy cells and were similar to processes occasionally seen connecting Langerhans cells to each other. Also, parallel tubular arrays were identified in the cytoplasm of hairy cells from 2 other patients. We conclude that autologous red blood cell and platelet engulfment is a common finding in hairy cell leukemia.

Aged↗
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↗