Stable and transmissible dicentric chromosome with terminal centromeres in ascites cell of mouse sarcoma 180

The occurrence of a stable and transmissible dicentric chromosome with 2 terminal centromers has been reported in the ascites form of mouse sarcoma 180 cells which is chromosomally hypotetraploid. The number of such dicentrics is 2 in all endoreduplicated cells. The probable mode of anaphase separation of the dicentric has been discussed.     

Stable and transmissible dicentric chromosome with terminal centromeres in ascites cells of mouse sarcoma 180

Summary The occurrence of a stable and transmissible dicentric chromosome with 2 terminal centromeres has been reported in the ascites form of mouse sarcoma 180 cells which is chromosomally hypotetraploid. The number of such dicentrics is 2 in all endoreduplicated cells. The probable mode of anaphase separation of the dicentric has been discussed.Grateful acknowledgment is made to Dr N. Chatterji, CNCRC, Calcutta, for supplying the cell-line to the first author. Sincere thanks are due to Prof. Prasanta Ghosh, Hooghly Mohsin College and to Dr A.K. roy, Department of Zoology of the same college for constant encouragement.     

Methylation of canine cardiac myosin in culture

Summary N, N, N, trimethyllysine and an unidentified methylated amino acid which co-electrophoresed and cochromatographed with the hydrolysis product of S-adenosyl-L-methionine, occur in fetal canine cardiac myosin and are isotopically labeled in vitro with S-adenosyl-L-(methyl³H) methionine between the 10th and the 12th day of culture.     

Tumor specific surface antigen in the culture medium of a rat cell line transformed by Rous sarcoma virus]

TSSA is detected on transformed cells by a mixed hemadsorption reaction. The medium of cultures of Rat cells transformed by Rous sarcoma virus (Prague strain, sub-group C) contains a soluble factor which specifically inhibits this reaction. This factor thus possesses the antigenic activity of TSSA which is associated with the presence of a component of molecular weight 42,000 by polyacrylamide gel electrophoresis.     

A cell culture substrate obtained from heat-fused collagen.

Coverslips coated with rat-tail collagen dried at 37 degrees C were placed in a hot-air sterilizing oven at 160 degrees C for 2 h. The resulting transparent sterile film was found to be a useful multipurpose substrate for cell culture and for subsequent histological sectioning.     

Microdialysis study of ischemia-induced hydroxyl radicals in the canine heart

A new experimental approach for spin-trapping of oxygen radicals in a selected region of the heart in situ is described. This approach is based on microdialysis, and it permits the detection of oxygen radicals in conditions of local ischemia and restoration of normal blood flow. Increased hydroxyl radical generation in an ischemic area of canine myocardium, as a result of 40 min local occlusion, has been studied.     

Proliferation and cell loss of human leukemic cell subpopulations in liquid culture

A kinetic study was performed on leukemic blasts from patients with acute myeloid leukemia, separated into 2 subpopulations by a specific density gradient. The growth curve and the [3H]-thymidine uptake were simultaneously analyzed. While cumulative nucleotide uptake fitted with the growth kinetics in the low-density fraction, such a concordance was not found in the high-density subpopulation. That indicated the occurrence of simultaneous growth and loss in the high density fraction, which could not be evaluated by a simple numerical determination.     

A comparative study of the differentiation of dissociated nerve cells under different culture conditions

Summary In vitro differentiation of chick embryo brain cells was compared under several culture conditions. Morphological observations and acetylcholinesterase histochemical staining revealed that the development was similar in all conditions tested if cells have been derived from 7 days embryos. Considering the cultures from 11 days embryos, the cell dissociation by trypsin and the plastic surface proved to be the most favourable conditions in contrast to mechanical dissection and collagen surface.M. Sensenbrenner is Maitre de Recherche au CNRS.     

Proliferation and cell loss of human leukemic cell subpopulations in liquid culture

Summary A kinetic study was performed on leukemic blasts from patients with acute myeloid leukemia, separated into 2 subpopulations by a specific density gradient. The growth curve and the [³H]-thymidine uptake were simultaneously analyzed. While cumulative nucleotide uptake fitted with the growth kinetics in the low-density fraction, such a concordance was not found in the high-density subpopulation. That indicated the occurrence of simultaneous growth and loss in the high density fraction, which could not be evaluated by a simple numerical determination.     

Contribution to the primary tissue culture technique. A new method for mechanical cell dispersion

Summary A new technique for preparing primary tissue cultures by mechanical cell dispersion was idealized. The time required to prepare a culture by this procedure was greatly reduced and the cultures obtained are morphologically and physiologically of better quality than that obtained by the classical methods of enzymatic cell dispersion.This work was supported by the Conselho Nacional de Pesquisas, Fundo Especial de Despesas do Instituto Butantan and DivisãoNacional do Cancer. The authors wish to thank Mrs.Sibylle Heller for the translation.     

A comparative study of the differentiation of dissociated nerve cells under different culture conditions.

In vitro differentiation of chick embryo brain cells was compared under several culture conditions. Morphological observations and acetylcholinesterase histochemical staining revealed that the development was similar in all conditions tested if cells have been derived from 7 days embryos. Considering the cultures from 11 days embryos, the cell dissociation by trypsin and the plastic surface proved to be the most favourable conditions in contrast to mechanical dissection and collagen surface.