High salt effect on RNA synthesis in Krebs ascites tumor cells

The incubation of Krebs ascites tumor cells in medium with a high salt concentration resulted in a partial inhibition of nuclear RNA synthesis. The residual RNA polymerase activity in such nuclei was only slightly inhibited by low concentrations (50 nM) of alpha-amanitin. This finding suggested an inhibition of RNA polymerase II activity under conditions of medium hypertonicity. Indeed, RNA polymerase II, isolated from the nuclei of cells exposed to hypertonicity, revealed only half of the control activity. On the other hand, RNA polymerase I was not affected by hypertonicity. Moreover, chromatin fractions isolated from cells incubated in hypertonic or isotonic medium were equally template-active in RNA synthesis.     

Stimulation of hemin synthesis in Ehrlich ascites tumor cells by mouse liver RNA

Résumé Les cellules ascites de la tumeur Ehrlich couvaient in vitro avec le précurseur radioactif de l'hémine-aminolévulinic acid-4-C¹⁴. Les préparations de ARN du foie de la souris stimulaient le niveau de synthèse de l'hémine.     

The effect of pyruvate on cyanide-inhibited respiration in intact ascites tumor cells

Riassunto È stato osservato che l'aggiunta di piruvato a cellule ascite di Ehrlich del topo è capace di rimuovere rapidamente l'inibizione della respirazione indotta da cianuro, restaurando l'integrità della fosforilazione ossidativa.     

Effect of dimethyl sulfoxide on RNA synthesis in S-180 tumor cells

Zusammenfassung Es hat sich gezeigt, dass Dimethyl-Sulfoxid (DMSO) die RNA-Synthese in Sarkom 180 Tumorzellen in vitro hemmt. In 15% DMSO betrug die Syntheserate nur 7% der Kontrolle. Diese Hemmung war leicht reversibel durch einfaches Entfernen des Wirkstoffes durch Auswaschen der Zellen mit Tyrodes-Lösung. Nach Entfernung des DMSO wurde eine leicht erhöhte Aktivität der Synthese beobachtet. Die Angaben wurden mit der Kinetik der Hemmung von DNA-Synthese verglichen und ihre möglichen Beziehungen zu anderen Wirkungen von DMSO beschrieben.     

Heterophile antigens in Ehrlich ascites tumor cells

Riassunto Gli autori hanno osservato che i sieri di animali immunizzati con cellule del tumore cancro ascite di Ehrlich sono emolitici per gli eritrociti di topo, ratto e montone e presumono che le cellule del tumore di Ehrlich possano contenere frazioni antigene di tipo eterogenetico.     

Incorporation of phospholipids in Ehrlich ascites tumor cells

Ehrlich ascites tumor cells (EATC) were incubated with unilamellar vesicles (UV) or multilamellar vesicles (MV). UV and MV were incorporated differently into EATC. The increase in 32P-phospholipid in EATC in the presence of UV was 12% in 300 min. Absorption of phospholipid from MV could account for only 3%. About 50% of the UV incorporation of 32P was by endocytosis and/or fusion.     

Incorporation of phospholipids in Ehrlich ascites tumor cells

Summary Ehrlich ascites tumor cells (EATC) were incubated with unilamellar vesicles (UV) or multilamellar vesicles (MV). UV and MV were incorporated differently into EATC. The increase in³²P-phospholipid in EATC in the presence of UV was 12% in 300 min. Absorption of phospholipid from MV could account for only 3%. About 50% of the UV incorporation of³²P was by endocytosis and/or fusion.This work was supported by a grant from the Consejo Nacional de Investigaciones Científicas y Técnicas, Argentina. J. L. Corchs is an investigator from the Consejo Nacional de Investigaciones Científicas y Técnicas.     

Effect of tannic acid on the Ehrlich ascites tumor cells

Summary Tannic acid was used to fix and stain Ehrlich ascites tumor cells in suspension. An increase in surface microvilli and cytoplasmic blebs in the tumor cells was observed. The mechanism of tannic acid induced surface morphological changes in tumor cells and the formation of a precipitate of protein-tannic acid-heavy metal complex are discussed.Acknowledgment. The author is grateful to Professor F. P. Lisowski for his advice and helpful criticism and to Mr Y. S. Tong for his expert technical assistance. This project was supported by a grant from the Hong Kong University Research Grants Committee.     

Interaction between mycoplasmas and Ehrlich ascites tumor cells

Zusammenfassung Es wurde gezeigt, dass die Adsorption von Mycoplasmen an Ehrlich Ascites-Tumorzellen an das Vorhandensein von neuraminidase-empfindlichen Zellrezeptoren gebunden ist.     

Effect of tannic acid on the Ehrlich ascites tumor cells.

Tannic acid was used to fix and stain Ehrlich ascites tumor cells in suspension. An increase in surface microvilli and cytoplasmic blebs in the tumor cells was observed. The mechanism of tannic acid induced surface morphological changes in tumor cells and the formation of a precipitate of protein-tannic acid-heavy metal complex are discussed.     

Glycerin prevents the 'heat-death' of Ehrlich ascites tumor cells

When heated to 45 degrees C for 20 min Ehrlich ascites tumor and NK-lymphoma cells are irreversibly damaged, so that they lose transplantability. The presence of 7-8% glycerol during heat treatment protects EAT cells completely and NK-lymphoma cells partly against this injury.     

The effect of acridities on the synthesis of RNA in isolated nuclei and intact HeLa cells

Zusammenfassung Eine Reihe von Acridinen wurde auf ihre Hemmung der RNS-Synthese intakter Zellen und isolierter Kerne untersucht. In Kernen wurden ähnliche Hemmungsverhältnisse gefunden wie in Bakterien, während in intakten Zellen die Reihenfolge der Stärke der Hemmwirkungen sehr verschieden ist.     

Relationship between A-type and C-type particles in Ehrlich ascites tumor cells

Summary Intracisternal and intracytoplasmic A-type particles were discovered in Ehrlich ascites tumor cells. In addition, mature and immature C-type particles were also seen in the intercellular space. It is believed that A particles may represent a precursor or a formative stage of the C particles.Acknowledgment. The author is grateful to Professor F. P. Lisowski for his advice and helpful criticisms and to Mr Y. S. Tong for his expert technical assistance. This project was supported by a grant from the Hong Kong University Research Grants Committee.     

The effect of RNA synthesis inhibitors on prenucleolar bodies

Summary Inhibition of RNA synthesis prevents the fusion of prenucleolar bodies in the NOR region during nucleologenesis. However, their physical coalescence between themselves is increased, as shown inAllium cepa L. meristems.This work has been partially supported by the Comisión Asesora para la Investigación Científica y Técnica (Spain). We greatly acknowledge M.L. Martínez and O. Partearroyo for their skilfull technical and secretarial work.     

Degranulating activity in hybrid cells derived from rat peritoneal mast cells and ehrlich ascites tumor cells

Summary Fusion of rat mast cells and Ehrlich ascites tumor cells was mediated by HVJ. Compound 48/80-induced degranulation occurred in the fused cells formed from two mast cells and one tumor cell, but not in the fused cells from one mast cell and two or more tumor cells.I am grateful to DrK. Utsumi for valuable discussions and for the donation of HVJ.