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J Sadowski

Publications and source records attributed to J Sadowski.

138 records · Page 8Linked to original sources
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Locating biologically active compounds in medium-sized heterogeneous datasets by topological autocorrelation vectors: dopamine and benzodiazepine agonists.

Electronic properties located on the atoms of a molecule such as partial atomic charges as well as electronegativity and polarizability values are encoded by an autocorrelation vector accounting for the constitution of a molecule. This encoding procedure is able to distinguish between compounds being dopamine agonists and those being benzodiazepine receptor agonists even after projection into a two-dimensional self-organizing network. The two types of compounds can still be distinguished if they are buried in a dataset of 8323 compounds of a chemical supplier catalog comprising a wide structural variety. The maps obtained by this sequence of events, calculation of empirical physicochemical effects, encoding in a topological autocorrelation vector, and projection by a self-organizing neural network, can thus be used for searching for structural similarity, and, in particular, for finding new lead structures with biological activity.

Databases, Factual↗
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Estimation of changes in renal tissue electrolytes from measurements of electrical admittance: application in the rat.

Alterations of cortico-papillary electrolyte gradient of the kidney can now be evaluated by continuous recording of tissue electrical admittance (a reciprocal of impedance), a variable changing directly with tissue concentration of free ions. Measurements are performed with needle electrodes placed in different zones of the in situ kidney, and it is then possible to follow the dynamics of changes in medullary electrolyte concentration. This approach, described recently from our laboratory, has so far been used in large animal species (dogs and rabbits). The present work describes an adaptation of the method for its use in the rat, accomplished by reducing the number and size of electrodes and a modification of their geometry. This satisfactorily minimized kidney damage secondary to insertion of electrodes. The information derived from admittance studies in the rat can be readily compared with numerous data on tubular transport of electrolytes obtained in this animal species.

Animals↗