High-content assay to study protein prenylation.

The mevalonate pathway leads to synthesis of cholesterol and isoprenoid lipids. Prenyltransferases attach the isoprenoid lipids to the C-terminus of several small guanosine triphosphate-binding proteins. The prenyl groups are essential for the biological activity of these proteins.

Identification of inhibitors of ribozyme self-cleavage in mammalian cells via high-throughput screening of chemical libraries.

We have recently described an RNA-only gene regulation system for mammalian cells in which inhibition of self-cleavage of an mRNA carrying ribozyme sequences provides the basis for control of gene expression. An important proof of principle for that system was provided by demonstrating the ability of one specific small molecule inhibitor of RNA self-cleavage, toyocamycin, to control gene expression in vitro and vivo. Here, we describe the development of the high-throughput screening (HTS) assay that led to the identification of toyocamycin and other molecules capable of inhibiting RNA self-cleavage in mammalian cells.

Exogenous control of mammalian gene expression through modulation of RNA self-cleavage.

Recent studies on the control of specific metabolic pathways in bacteria have documented the existence of entirely RNA-based mechanisms for controlling gene expression. These mechanisms involve the modulation of translation, transcription termination or RNA self-cleavage through the direct interaction of specific intracellular metabolites and RNA sequences. Here we show that an analogous RNA-based gene regulation system can effectively be designed for mammalian cells via the incorporation of sequences encoding self-cleaving RNA motifs into the transcriptional unit of a gene or vector.

[In vitro test of piezoelectric lithotripsy with ultrasound detection using an EDAP LT 01 lithotripser].

200 in vitro shots were performed with an EDAP LT 01 system in order to test the sensitivity of the various urinary stones to lithotrity and to study the action of the various shot parameters. All calculi do not have an equally favorable reaction to lithotrity. The deciding factor is neither their hardness, nor their chemical composition, nor their crystallizing shape, but rather the architecture ruling the arrangement of the crystallins forms in the calculus.

[Extracorporeal lithotripsy of biliary lithiasis. 160 patients treated with an EDAP apparatus].

Since February 1987, we have been using extracorporeal lithotripsy for certain cases of chronic biliary lithiasis, using an EDAP lithotripter. The technique is reserved for patients with less than four radiotransparent, or partially calcified calculi, less than 25 mm in size, within the context of a functioning gall bladder with no evidence of lithiasis in the C.B.