13 research outputs found
Localization of genes on human chromosomes
The genetic machinery of cells controls the biological functions such as
food uptake, biosynthesis and reproduction. External characteristics and
complex patterns of behaviour at the level of the organism are also
programmed in the genetic material. The mechanisms of expression of
the genes and the regulation of expression have been studied extensively
in micro-organisms. These studies have revealed information about the
position of genes on the chromosomes of these cells and about their
function in cell metabolism. The techniques available for the formation
of new combinations of genetic information such as fusion of cells
(conjugation), transfer of genes by isolated DNA (DNA-transformation)
and transfer by viruses (transduction) have facilitated the genetic studies.
The investigation of gene expression in multicellular organisms
including man has been hampered by the absence of techniques which
could provide genetic recombination. New recombinations are produced
in nature by sexual reproduction. Therefore, for many years, the formation
of gametes and the recombinations between chromosomes, which
occur during meiosis, have provided the basis for the study of the
genome of higher organisms including man
Relating mulltidrug resistance phenotypes in the kinetic properties of their drug efflux pumps.
The simplest model for pump-mediated multidrug resistance is elaborated quantitatively. The way in which toxicity data should be evaluated to characterize most effectively the drug-efflux pump is then examined. The isotoxic drug dose (