Effect of infection of mice with Friend leukemia complex viruses on background antibody-forming cell production in vitro

Friend leukemia complex (FLC), and Rowson-Parr virus (RPV) infections of donor mice depress the production of background antibody-forming cells by splenocytes cultured in the absence of specific antigenic stimulation.     

Effect of infection of mice with Friend leukemia complex viruses on background antibody-forming cell production in vitro

Summary Friend leukemia complex (FLC) and Rowson-Parr virus (RPV) infections of donor mice depress the production of background antibody-forming cells by splenocytes cultured in the absence of specific antigenic stimulation.Supported in part by a grant from the Italian Research Council (Progetto finalizzato virus, CT 77.00248.84).     

Scanning electron microscopy of antibody-dependent cell-mediated cytotoxicity of Friend leukemia virus-infected spleen cells

Summary Friend leukemia virus (FLV) infected splenocytes treated with rabbit anti-FLV serum and subsequently incubated with splenic lymphocytes from non-immune Balb/c mice were examined by scanning electron microscopy. Villous-covered lymphocytes adherred to the tumor cells and induced surface blebs, numerous membrane pores and eventual tumor cell lysis.     

Heterogeneity of molecular markers in chronic myelomonocytic leukemia: a disease associated with several gene alterations

The relatively homogenous clinical features and poor prognosis of chronic myelomonocytic leukemia (CMML) are associated with a molecular heterogeneity, with various mutations impacting several convergent pathways. Due to the restricted understanding of the mechanism involved in leukemogenesis, CMML still appears as a diagnostic and therapeutic undertaking, and poor prognosis of leukemia. Contrary to chronic myelogenous leukemia, BCR-ABL1-positive, cytogenetic, and molecular abnormalities of CMML are not specific and not pathognomonic, confirming the different levels of heterogeneity of this disease. Various mutations can be associated with a common phenotype not distinct at the clinical level, further demonstrating that molecular probings are needed for choosing individual targeted therapies.     

Ropalocytosis in acute leukemia

Summary Unusual club-shaped processes have been seen in the lymphoblasts in the peripheral blood of case of untreated acute leukemia. These arose from a single area of the cell surface and appeared identical to the morphologic change seen in ropalocytosis in red cells. Red cells in the peripheral blood were also affected.     

Scanning electron microscopy of antibody-dependent cell-mediated cytotoxicity of Friend leukemia virus-infected spleen cells.

Friend leukemia virus (FLV) infected splenocytes treated with rabbit anti-FLV serum and subsequently incubated with splenic lymphocytes from non-immune Balb/c mice were examined by scanning electron microscopy. Villous-covered lymphocytes adherred to the tumor cells and induced surface blebs, numerous membrane pores and eventual tumor cell lysis.     

In vitro transmission of mouse leukemia virus to restrictive mouse cells: necessity for mixed infection by two different leukemia viruses]

The plaque formation of murine leukemia virus (MuLV) in non permissive mouse cells (N-tropic MuLV in B-type cells, or B-tropic MuLV in N-type cells) was increased by murine sarcoma virus whose plaque-forming activity was extremely low (MuSV XC-). The infection of N-tropic MuLV in B-type cells was increased by MuSV XC- propagated only in N-type cells but not in B-type cells, and the infection of B-tropic MuLV in N-type cells by MuSV XC- propagated only in B-type cells but not in N-type cells.     

Clonogenic growth of acute non-lymphocytic leukemia cells in serum-free medium

We devised a serum-free medium for growth of leukemic colony-forming units (CFU-L), enriched with albumin, transferrin, lipids, insulin, hydrocortisone and oligoelements. Blast cells from 15 patients affected by acute non-lymphocytic leukemia were grown in this medium in the presence of human placental conditioned medium obtained under serum-free conditions (sfHPCM). Their clonogenic growth was comparable with that obtained in a serum-containing system. Furthermore, when serum-free cultures were carried out in absence of sfHPCM, either CFU-L growth was prevented or, if clones were obtained, the cultures showed a marked decrease in clonogenicity, indicating their strict dependence on growth factors.     

Clonogenic growth of acute non-lymphocytic leukemia cells in serum-free medium

Summary We devised a serum-free medium for growth of leukemic colony-forming units (CFU-L), enriched with albumin, transferrin, lipids, insulin, hydrocortisone and oligoelements. Blast cells from 15 patients affected by acute non-lymphocytic leukemia were grown in this medium in the presence of human placental conditioned medium obtained under serum-free conditions (sfHPCM). Their clonogenic growth was comparable with that obtained in a serum-containing system. Furthermore, when serum-free cultures were carried out in absence of sfHPCM, either CFU-L growth was prevented or, if clones were obtained, the cultures showed a marked decrease in clonogenicity, indicating their strict dependence on growth factors.     

Effect of colicin E3 on leukemia cells P388 in vitro.

Proliferation of murine leukemia cells P388 is stimulated by less than 1.0 mg/ml colicin E3, while being inhibited by higher concentrations. By 1.6 mg/ml colicin E3, uptake of thymidine into cold TCA-precipitable fraction is decreased by 59% during 24 h, uptake of uridine by 29%.     

Effect of colicin E3 on leukemia cells P 388 in vitro

Summary Proliferation of murine leukemia cells P388 is stimulated by less than 1.0 mg/ml colicin E3, while being inhibited by higher concentrations. By 1.6 mg/ml colicin E3, uptake of thymidine into cold TCA-precipitable fraction is decreased by 59% during 24 h, uptake of uridine by 29%.     

Antiinflammatory reaction associated with murine L1210 leukemia

Summary Mice bearing L1210 leukemia did not show impaired humoral or cellular immune response to antigenic stimulation during the early stage of the tumor, and a depressed response was noted only in the terminal stage. L1210 cells were shown to suppress inflammatory reaction in vivo.Supported in part by USPHS research grant No.5-01-RR05-352-12, and by theIndependent Order of Foresters, San Bernardino District 3208. We acknowledge the valuable assistance ofJudith Johnson andJames Tan in this project. Histopathological examination byDick H. Koobs is appreciated.     

The presence of an endogenous peroxidase activity in hairy cell leukemia cells]

Mononuclear cells from hairy cell leukemia have been studied in three cases by ultrastructural immunocytochemistry. Cells have fairly detectable surface immunoglobulins, without monoclonal distribution however. In addition these cells have a peroxidatic activity which is revealed in the perinuclear space and strands of endoplasmic reticulum.     

T-cell leukemia induced by 1-propyl-1-nitrosourea in Fischer rats

Summary T-cell leukemia was induced at a high rate in female Fischer rats by continuous oral administration of 1-propyl-1-nitrosourea. No association of oncorna viruses were found in the leukemogenesis.The authors are greatly indebted to Professor K. Yokoro of the Department of Pathology, Research Institute for Nuclear Medicine & Biology, for his valuable suggestions. This work was supported in part by a Grant-in-Aid for Cancer Research from the Ministry of Education, Science and Culture, Japan.     

Effect of lithium on normal and chronic granulocytic leukemia colony forming cells (CFU-GM)

Summary The effect of lithium on normal and chronic granulocytic leukemia (CGL) granulo-monocytic precursors (CFU-GM) has been studied. Lithium slightly increases normal CFU-GM growth whereas it is without effect or moderately inhibitory for CGL CFU-GM. It is suggested that it is unlikely that lithium therapy enhances the proliferation of a silent leukemic clone.Acknowledgments. The authors wish to thank Prof. F. Gavosto for his suggestions. This work was supported by CNR, PFCCN, grant No.80.0155796.     

Reappearance in vivo of neuraminidase-sensitive sialic acid in L 5222 rat leukemia cells

Summary Cell electrophoretic data and quantitative sialic acid determination show that, 16 to 20h after i.p. implantation of neuraminidase-treated L 5222 rat leukemia cells, the original sialic acid content at the cell periphery is reconstituted.This investigation was performed within the EORTIC Cell Surface Project Group and supported by the Swiss National Science Foundation, Grant No. 3.901.72, and by the Zürich Cancer League.     

Antiproliferative effects of 4',5'-unsaturated adenine nucleosides on leukemia L1210 cells in vitro

Several 4',5'-unsaturated adenine nucleosides were shown to have antiproliferative activity against L1210 leukemia cells in vitro. The active nucleosides were cytotoxic to the L1210 cells as demonstrated by Trypan Blue uptake. The cytotoxicity was not induced by alterations in the ribonucleoside and deoxyribonucleoside triphosphate levels of the L1210 cells.     

A new variety of acute non-promyelocytic leukemia with t(15;17)]

Three cases of a new variety of acute leukemia have been reported. The main features were: hyperleukocytosis made of large-sized blasts with a double shaped nucleus, few or no granulations in the cytoplasm, and in a few cell faggots or unique Auer rods; mycloperoxydase reaction was positive. This feature was associated with disseminated intravascular coagulation syndrome and t(15;17)(q22;q21) translocation in the majority of mitoses.     

Effect of lithium on normal and chronic granulocytic leukemia colony forming cells (CFU-GM)

The effect of lithium on normal and chronic granulocytic leukemia (CGL) granulo-monocytic precursors (CFU-GM) has been studied. Lithium slightly increases normal CFU-GM growth whereas it is without effect or moderately inhibitory for CGL CFU-GM. It is suggested that it is unlikely that lithium therapy enhances the proliferation of a silent leukemic clone.