1,720,985 research outputs found
The peculiar binding properties of 4'-deoxy,4'-iododoxorubicin to isolated DNA and 175 bp nucleosomes
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Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Anthracycline antibiotics supported on water-soluble polysaccharides: Synthesis and physicochemical characterization
No full textDaunomycin and adriamycin, two potent anthracycline antibiotics, have been covalently bound to the biocompatible polysaccharides sodium hyaluronate and carboxymethylcellulose. The water-soluble conjugates have been investigated by means of spectroscopic and hydrodynamic techniques. The conformation properties of the polysaccharide chains are not dramatically affected upon derivatization. The acidic dissociation constants of the polymer-supported anthracyclines are decreased as a result of polyelectrolyte effects from the negatively charged backbone. The polymeric drugs are able to bind efficiently biologically relevant metal ions, in particular Cu++. The binding stoichiometry, with reference to the parent anthracyclines, is somewhat changed under similar experimental conditions. The equilibrium constants for Cu++ binding show on the other hand characteristics well related to the corresponding properties of the original compounds. In addition, the redox potentials of the drugs remain pr..
Interaction of nucleosomes with anthracycline antibiotics: relevance to anticancer activity.
No full textInteraction between second generation anthracyclines and DNA in the nucleosomal structure
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Water-soluble polysaccharide-anthracycline conjugates: biological activity
No full textThe anticancer agents doxorubicin and daunorubicin were covalently linked to the water-soluble anionic polysaccharides hyaluronic acid and carboxy-methylcellulose. The drug-polymer conjugates are in principle prevented from entering cells, can efficiently bind to cell surfaces and allow precise dose-response determinations. In addition, they are not able to bind DNA because of their negative charge. Cell growth and DNA synthesis inhibition studies indicated decreased cell toxicity for the polymer conjugates. The mol. wt of the carrier was shown to affect the biological activity of the anthracycline to a moderate extent. Partial drug incorporation into cells was observed as a function of time, probably due to endocytosis phenomena followed by biochemical cleavage of the conjugate. The conclusion was drawn that membrane binding appears to contribute to total toxicity only to a minor extent
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