Induction of megakaryocytic characteristics in human leukemic cell line K562: polyploidy, inducers, and secretion of mitogenic activity

Because of the rarity of megakaryocytes in the bone marrow, a cell line inducible for megakaryocytic characteristics provides a valuable model for study. When cultured with phorbol esters, the human multipotent hematopoietic leukemic cell line K562 can be induced to develop many megakaryocytic characteristics, viz. increased cell size, reduced growth rate, megakaryocytic antigens, and expression of the sis proto-oncogene, the structural gene for the B-chain of platelet-derived growth factor. Further aspects of this process are here presented. First, it induces the release of mitogenic activity into the medium. Second, phorbol dibutyrate induces polyploidy, a feature of normal megakaryocyte development. Third, mezerein and teleocidin, nonphorbol ester tumor promotors, also induce development of multinuclearity and polyploidy.     

Quirks of dye nomenclature. 10. Eosin Y and its close relatives

The long history of eosin Y, eosin B and the methyl and ethyl eosins is recounted as well as their synthesis, the variety of their molecular species and some of the myriad applications of these dyes. Chromatographic techniques are described that reveal the purity or lack of it in commercial samples. Toxicological studies are discussed that suggest that the eosins are virtually non toxic, but efforts to remove them from the environment imply that there may be some risk.     

Transfer and integration of chromosomal genes from Pseudomonas glycinea into Pseudomonas aeruginosa.

The plasmids FP2 and R68.45 were shown to function as chromosome-mobilizing plasmids in a series of interspecific crosses between the phytopathogen Pseudomonas glycinea and the human pathogen Pseudomonas aeruginosa. At least four of seven loci tested were transferred from P. glycinea donors to P. aeruginosa auxotrophic recipients. Transductional analysis indicates that a leu+ locus of the P. glycinea chromosome transferred is stably integrated into the P. aeruginosa chromosome.     

Communication of Genetic Information within Families: The Case for Familial Comity

Advances in genetic technologies raise a multitude of ethical issues, some of which give rise to novel dilemmas for medical practice. One of the most controversial problems arising in clinical genetics is that of confidentiality and who may disclose genetic health information. This paper considers the question of when it is appropriate for health professionals to disclose clinically significant genetic information without patient consent. Existing ethical principles offer little guidance in relation to this issue. We build on suggestions that genetic information may be viewed as collective or shared information, and we introduce the concept of ‘familial comity’ as a fresh way to consider the issues.Competing Interests: None declared. Funding: No special funding was secured for this research.