The diploid deoxyribonucleic acid (DNA) content of basal cell carcinomas in man

Zusammenfassung Der Desoxyribonukleinsäuregehalt ist bei Basalzellkarzinomen diploid im Tumor selbst, weicht jedoch bei invadierenden Stellen nach Diploidie ab.     

Karyotypes and nuclear DNA contents of Polypteridae (Osteichthyes)

Summary Calamoichthys calabaricus, Polypterus palmas, P. weeksii, P. delhezi andP. ornatipinnis have the same amount of DNA per erythrocyte nucleus. The karyotype ofP. weeksii has 38 chromosomes and differs from the karyotypes of the other species, all with 36 chromosomes, by a Robertsonian chromosomal rearrangement. The karyotype condition is regarded as derived for vertebrates.Research supported by the Division of Human Genetics, K.U. Leuven, Belgium and the UNAZA, campus Kinshasa, Zaire. The Department of Human Genetics, University of Amsterdam, Netherlands, provided facilities for cytophotometry.     

Induction of deoxyribonucleic acid degradation inEscherichia coli by ozone

Summary Cell survival and deoxyribonucleic acid (DNA) degradation were measured for wild-typeEscherichia coli B251 cells after exposure to different concentrations of ozone. The results show that extensive breakdown of DNA occurs after ozonation and that the extent of ozone-induced DNA degradation generally correlates with the colony-forming ability of the cells.We thank Dr M.J. d'Aoust for supplying laboratory facilities. This work was jointly sponsored by the National Research Council of Canada, the Ministère de l'Education du Québec, and funds from the Université de Montréal. One of us (C.H.) acknowledges a postgraduate scholarship from the NRC of Canada.     

The effect of 7,12-dimethylbenz(a)anthracene on the incorporation of thymidine-H3 into deoxyribonucleic acid in normal and regenerating liver

Riassunto L'idrocarburo cancerogeno 7,12-dimetilbenz(a)antracene somministrato con iniezione endoperitoneale inibisce l'incorporazione della timidina nel DNA del fegato normale e del fegato rigenerante di ratto.     

Induction of deoxyribonucleic acid degradation in Escherichia coli by ozone.

Cell survival and deoxyribonucleic acid (DNA) degradation wave measured for wild-type Escherichia coli B251 cells after exposure to different concentrations of ozone. The results show that extensive breakdown of DNA occurs after ozonation and that the extent of ozone-induced DNA degradation generally correlates with the colony-forming ability of the cells.