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Biomedical subjects

A Levan

Publications and source records attributed to A Levan.

At least 37 records · Page 2Linked to original sources
PubMed1978

A new chromosome type replacing the double minutes in a mouse tumor.

For several years the SEWA mouse ascites tumor has been a carrier of double minute chromosomes (DMs), some 90% of its cells containing from one to several hundred DMs. In one specific subline of this tumor, the cells with DMs had decreased in frequency to less than 5% of the cells. At the same time, the stemline chromosome number had increased from 43 to around 50. This was due to the presence, in addition to the ordinary telocentric chromosomes, of a varying number of medium-sized metacentrics. The fact that these chromosomes deviated from ordinary mouse chromosomes in special features, such as median centromeric position, early DNA replication, and complete lack of centromeric heterochromatin, indicates that they represent a new type of chromosome. Their striking agreement with the DMs in many properties makes it tempting to associate their origin with the disappearance of the DMs.

Animals↗
PubMed1972

Tumor etiology and chromosome pattern.

Fibrosarcomas induced in Chinese hamsters and rats by Rous sarcomla virus and 7,12-dimethylbenz(a)anthracene are associated with nonrandom chromosome variation. Although histologically indistinguishable, the tumors induced by the virus or chemical in each host species are characterized by completely different karyotypic patterns.

Animals↗