Action of Daunomycin on Nucleic Acid Synthesis in Hepatoma Ascites Cells Incubated « in vitro »

The action of Dannomycin, an antibiotic of Rhodomycin group, was studied following the incorporation of Adenine-8-14C into nucleic acid of hepatoma ascites cells incubated « in vitro ». Doses of 20 μg/ml of the antibiotic were able to inhibit the uptake of the precursor by RNA; the activity of the drug appeared to be dependent on the density of the cell population. As it was noted that, under our experimental conditions, a partial inhibition of the incorporation was caused by these doses of Daunomycin, some RNA fractions were isolated from cells and tested for their sensitivity to the antibiotic. A high-activity RNA extracted from nuclei appeared to be the most sensitive to the Daunomycin action. At higher doses of Daunomycin the incorporation into DNA was also lowered. </jats:p

Effect on the Sensitivity of Lymphoid Cells to Acriflavine after « in vivo » Treatment with Heterologous Albumin Coupled with Diazotized Acriflavin

The possibility that the «in vivo» treatment with heterologous albumin coupled with diazotized acriflavine may affect the sensitivity of lymphoid cells to the action of acriflavine was studied. Albino mice CFW strain were treated subcutanceusly with the coupled albumin in the presence of complete Freund adjuvant. Lymph nodes from control and immunized animals, fifteen days after the treament, were cultured «in vitro» in the presence of different doses of acriflavine (from 0.5 to 4 μg/ml). The action of acriflavine was evaluated as the growth of cultures, the percent of lymphoid cells in the different phases of differentiation and the percent of proliferating cells after incubation for 24 hours in the presence of 3H thymidine. Results show that lymphoid cells of immunized mice are less sensitive to the citotoxic activity of acriflavine than those of the controls. Acriflavine, at low doses, reduces the growth of normal cultures and the proliferative activity of immature elements. At the highest doses the proliferation area is almost completely absent and the elements still present are strongly degenerated. Acriflavine, at the concentration able to reduce or to inhibit the growth of control cultures, is ineffective in altering the ratio of immature elements in cultures of immunized animals. The ability of these elements to incorporate 3H thymidine is also unchanged. </jats:p

Synergistic Effect of Daunomycin and Immunization on the Growth of Transplantable Tumors

By immunization with antigenic fractions obtained from the tumor, injected in the presence of Freund complete adjuvant, it is possible to obtain an immunological reaction against the implantation of Sarcoma 180 in albino Swiss mice. The treatment with the antibiotic Daunomycin, some days after the implantation of the tumor in immunized mice, produces an inhibiting effect on the tumor growth significantly higher than that due to the immunization or to the drug alone. The synergistic effect is more relevant with the low dosage of the antibiotic than with the higher one. This behavior may be related to the depressing activity of the drug towards lymphopoietic tissues. </jats:p

Clinical and Immunological Study in Disproliferative Disorders of Plasmacells

Immunological investigations in 4 multiple myelomas with bone lesions, in 1 extraosseus myeloma, and in 1 reticulum-cell sarcoma with areas of plasma cellular transformation are described. Serum proteins were studied with immunodiffusion, immunoelectrophoresis and sedimentation constant. All identified serum paraproteins in the myeloma patients appeared to be of the IgG type, but with different electrophoretic mobility. Three cases were classified as «slow», one as «fast» and one as «intermediate» type. In the patient with reticulum-cell sarcoma alterations of the antigenic properties of the IgG immunoglobulins were present and they were compatible with the presence of a paraprotein. The immunoelectrophoretic pattern as well as the quantitative determination with immunoplates of the immunoglobulins yielded results almost directly proportional to the percentage of plasmacells detected through bone marrow aspiration and to the extent of the disease. </jats:p