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Biomedical subjects

V Chudomel

Publications and source records attributed to V Chudomel.

At least 37 records · Page 2Linked to original sources

Derivatives of benzo(c)fluorene. X. Inhibitory effect of Benfluron on cellular immunity.

The effect of a cytostatic drug Benfluron-- 5(2-N,N-dimethyl-amino-ethoxy)-7-oxo-7H-benzo(c)fluorene hydrochloride was tested in mice on skin graft survival, graft-versus-host reaction (GVHR) and for mitogenic stimulation of human lymphocytes. Application of Benfluron resulted in a prolonged skin graft survival. The regional and systemic GVHR was potentially inhibited by p. o. administration of Benfluron at a dose of 100 mg/kg of body weight. Allogeneic spleen cells incubated with Benfluron at concentration of 5-20 micrograms/ml showed reduced capability to induce GVHR. PHA or PWM stimulation of lymphocytes was completely inhibited in the presence of 2 micrograms/ml Benfluron. Benfluron as a potent immunosuppressive agent can be considered useful for the prevention of GVHR.

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Derivatives of benzo(c)fluorene. XI. Effect of Benfluron on hemopoietic stem cells.

The effect of Benfluron-- 5-(2-N,N-dimethylamino-ethoxy)-7-oxo-7H-benzo(c)fluorene hydrochloride--on hemopoietic stem cells was tested by the production of spleen cell colonies (CFU-S) in irradiated mice following application of bone marrow cells and by the production of hemopoietic colonies (CFU-C) in semisolid agar. The reduced numbers of CFU-S were found in mice applied Benfluron or Benfluron-treated bone marrow cells. The increased numbers of CFU-S, however, were found in mice receiving bone marrow cells from Benfluron-treated donors. The production of CFU-C was decreased after 2 h incubation of bone marrow cells with 0.5-5 micrograms/ml of Benfluron, and fully inhibited at higher concentrations.

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Effect of vaccine prepared from Corynebacterium parvum on the growth of Gardner lymphosarcoma in C3H strain mice.

The present paper discusses the effect of a vaccine prepared with formol-killed Corynebacterium parvum (alias Propionibacterium acnes) on the growth of solid Gardner lymphosarcoma transplanted on C3H (H-2k) mice. The vaccine was injected at various time intervals prior to, simultaneously with, or following transplantation of the tumor to intact mice or mice immunized with 60Co-irradiated Gardner tumor cells. The effectivity was evaluated in terms of numbers of mice surviving without tumor 60-day observation period or prolongation of survival time. Reliable effectivity showed vaccine (0.8 mg dry weight of C.p.) in the mixture with tumor transplant or when introduced 6 days earlier into the site of tumor transplantation. The preventive action of the vaccine was more pronounced in the mice immunized with inactivated tumor. The vaccine applied to mice with a transplanted tumor was ineffective and failed to significantly prolong the survival time even in mice which had previously been immunized with an inactivated tumor.

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Treatment of C3H mice bearing solid Gardner lymphosarcoma with vaccine prepared from Corynebacterium parvum combined with methotrexate and Alexan.

C3H mice after transplantation of solid Gardner lymphosarcoma were injected with Methotrexate (MTX) or Alexan. The prolonged survival time of mice treated with antimetabolites was in some cases evidently reduced after an additional injection of Corynebacterium parvum (C.p.). This reduction did not depend on the sequence of corynebacterial vaccine or MTX injections. Significantly better effect of combined treatment with MTX injection and C.p. was found only once in mice preimmunized with the tumor irradiated from 60Co gamma source.

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Differentiation of human myeloid leukemia cell lines induced by tumor-promoting phorbol ester (TPA). I. Changes of the morphology, cytochemistry and the surface differentiation antigens analyzed with monoclonal antibodies.

Human myeloid leukemia cell lines ML-1, ML-2, ML-3, promyelocytic leukemia cell line HL-60 and histiocytic lymphoma cell line U-937 were induced to differentiate by 0.5-10 ng/ml (0.8-16 nM) 12-O-tetradecanoylphorbol-13-acetate (TPA). After 48-72 h of induction, changes of the morphology, cytochemistry and of the antigenic phenotype of induced and control cells were studied using a panel of monoclonal antibodies against granulocytic, monocytic, HLA-ABC and HLA-DR antigens in indirect immunofluorescence. Cells of the TPA-treated cultures acquired morphological, cytochemical and antigenic markers of monocytes/macrophages, as surface adherence, alpha-naphthyl acetate esterase (alpha-NE) and acid phosphatase activity and the expression of monocytic antigens detected with monoclonal antibodies 63D3, FMC 17, B 44.1, B 52.1 and anti-Mol. During differentiation in vitro induced by TPA, also loss of HLA-DR antigens and diminution of antigen of cell activation were detected with antibodies L 243 and 4F2. The expression of granulocytic antigens was only slightly diminished and the expression of HLA-ABC antigens was not changed by TPA-treatment. There were differences in the percentage of cells induced to differentiate among the lines of different origin and even among the lines ML-1, ML-2 and ML-3, established from a single patient with acute myeloid leukemia. After treatment of cultures with 5 ng/ml TPA for 72 h DNA synthesis was inhibited to 60-80%.

Acid Phosphatase↗

Immunosuppressive effects of bovine seminal fluid fractions with ribonuclease activity.

Using different isolation procedures (after acidification and saturation with 3 M ammonium sulphate) three fractions were isolated from bull seminal vesicle fluid and assayed for their effects on cell immunity in vitro and in vivo. Two of these preparations (ZS RNase and AS RNase) possessing a high level of ribonuclease activity at concentrations of 50 micrograms/ml showed inhibitory effects (up to 80%) on 3H-thymidine incorporation into the DNA of mitogen-or antigen-stimulated human lymphocytes. The third preparation (3M-P) possessing low ribonuclease activity showed lesser inhibitory effects. The potency of mouse spleen cells to cause regional GVH reaction was significantly decreased after preincubation of spleen cells to cause of 1 mg per AS RNase or ZS RNase whereas 3M-P was ineffective in this test. A single dose of 1 mg per mouse of ZS RNase or 3M-P administered i.p. on day 4 after skin transplantation significantly prolonged graft rejection. Both preparations at this dose potentiated the effect of cyclophosphamide on skin graft survival. All tested preparations preincubated with mouse bone marrow cells had no adverse effects on their colony-forming activity (in the spleens of irradiated mice). The possibility of utilizing the preparations with ribonuclease activity isolated from vesicle fluid in clinical bone marrow transplantation is discussed.

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Culture of macrophage cell lines from normal mouse bone marrow.

The use of semisolid medium for the culture and cloning of haematopoietic cells has helped our understanding of their proliferation and differentiation. It has been shown that mixed colonies of granulocytes and macrophages developed, in the presence of colony-stimulating factor (CSF), from their common precursor, granulocyte-macrophage colony-forming cells (GM-CFC). Attempts at recloning these colonies in semisolid medium suggested that granulocytes and macrophages were differentiated cells incapable of further proliferation. However, our studies on cultures of larger numbers of cells demonstrate that while this may be the case for granulocytes, macrophages seem to be capable of long-term proliferation.

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Inhibitory effects of 5-azapyrimidine nucleosides on cellular immunity.

The effect of 5-azacytidine (5-AzCR) and 5-aza-deoxycytidine (5-AzCdR) on the survival of skin grafts in mice and rats, the action of these drugs on regional GVH reaction, as well as the formation of haemopoietic colonies (CFU-5) in the spleen were studied. Both drugs prolonged the life span of skin grafts when administered 24 hr before transplantation, or on the 4th post-transplantation day. However, they were little effective when injected 24 hr after skin grafting, or after induction of the regional GVHR. Following intraperitoneal administration, they inhibited CFU-5 formation. Two-hour incubation in vitro of cells with 5-AzCR significantly reduced their GVH reactivity and capacity to form CFU-5; 5-AzCdR under the same conditions was ineffective.

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Inhibitory effect of bovine seminal ribonuclease on activated lymphocyte and lymphoblastoid cell lines in vitro.

The native dimer bovine seminal ribonuclease, AS RNase, and its four modified derivatives (carboxymethylated, succinylated, oxidated and reduced) were examined for their effects on PHA- or PWM-stimulated human lymphocytes, mixed lymphocyte cultures and lymphoblastoid cell line line (Molt-3, RAJI, UHKT-2 and UHKT-5). Among all substances tested the native AS RNase exerted the strongest suppressive effect on PHA-, PWM-, and MLR- stimulated lymphocytes. At concentrations of 5 and 100 microgram/ml AS RNase inhibited lymphocyte stimulation in MLR by 40 and 95%. The carboxymethylated and reduced derivatives possessed inhibitory effect one order lower, while the succinylated derivative showed a negligible effect, and the oxidated derivative was ineffective. The inhibitory effect on PHA-stimulated lymphocytes was not reduced when AS RNase was added to lymphocyte culture 24 or 48 h later. Likewise, the 20-fold increase in PHA concentration did not cause any decrease in inhibitory effect of AS RNase. AS RNase added to transformed lymphocytes simultaneously with 3H-TdR did not affect the thymidine uptake. As RNase also had the strongest inhibitory effect on growth, viability and the DNA synthesis in all lymphoblastoid cell lines tested. After 72 h cultivation with AS RNase at a concentration of 100 microgram/ml, the DNA synthesis decreased by more than 90% in Molt-3 and UHKT-2 cells. Simultaneously reduction in cell count and increased numbers of dead cells compared to control cultures were found. Carboxymethylated derivative at the same concentration inhibited thymidine incorporation into the DNA by 70% but did not cause any cytotoxic effect. Other derivatives showed negligible or null effects. These results are in agreement with some data published earlier, that the dimer of seminal ribonuclease exerts a significant antitumour effect. The immunosuppressive effects of AS RNase observed in the present paper suggest that this compound is one of the components of seminal plasma which may take part in suppression of immune responses of the female reproductive tract to spermatozoa.

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Human placental conditioned medium (from different phase of pregnancy) as a source of colony-stimulating activity for cultures of human and mouse. granulocyte-macrophage colony-forming cells in semisolid agar.

We have investigated the effect of conditioned medium derived from cultures of human placental tissue from different phases of pregnancy on in vitro growth of human and mouse granulocyte-macrophage colony forming cells in semisolid agar. We have confirmed that the colony-stimulating activity of human placental conditioned (normal delivery) medium was equivalent to the activity of peripheral blood leucocyte underlayers when medium was added at a 5%-20% concentration to the semisolid agar. Placentas from the 12th amd 10th week of gestation were found not convenient for preparation of medium with high CSA; the activity of media prepared from their cultures was not significantly higher than the autostimulating activity of bone marrow alone. Human placental conditioned medium proved inconvenient for cultures of mouse GM-CFC in semisolid agar containing foetal calf serum.

Agar↗

The effect of Damvar on the formation of hemopoietic splenic colonies in mice, and on the peripheral blood picture in rats and dogs.

The present paper deals with the effect of Damvar on hemopoiesis. The test of formation of hemopoietic splenic colonies (CFU-S) was used in mice, the peripheral blood picture and bone marrow differential after long-term administration of Damvar was tested in rats and dogs. The bone marrow cells from mice after a single dose of Damvar or cells incubated with Damvar in vitro showed no reduction of colony-forming activity. A single dose or repeated variable doses of Damvar, or combined administration of Damvar and Cyclophosphamide in some cases influenced the number of CFU-S in irradiated mice following transplantation of normal murine bone marrow cells. A number of CFU-S lower than 75% of the control count was never found. The application of Damvar to rats and dogs caused no significant changes in their blood pictures and bone marrows.

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