An inventory of 1152 expressed sequence tags obtained by partial sequencing of cDNAs from Arabidopsis thaliana.

As part of the goal to generate a detailed transcript map for Arabidopsis thaliana, 1152 single run sequences (expressed sequence tags or ESTs) have been determined from cDNA clones taken at random in libraries prepared from different sources of plant material: developing siliques, etiolated seedlings, flower buds, and cultured cells. Eight hundred and ninety-five different genes could be identified, 32% of which showed significant similarity to existing sequences in Arabidopsis and an array of other organisms. These sequences in combination with their positioning on the Arabidopsis genetic map will not only constitute a new set of molecular markers for genome analysis in Arabidopsis but also provide a direct route for the in vivo analysis of their gene products. The sequences have been made available to the public databases.

Contribution of pharmacokinetic computerized simulations in toxicological approach of ochratoxin A.

An open two-compartment model described the fate of ochratoxin A in the rat. Curves of toxin quantities contained in the two compartments and predicted plasma concentrations following 1-, 2-, or 3-daily administrations were simulated by use of mathematical expressions programmed for a digital computer. These studies clearly showed residues of ochratoxin A in deep compartment tissues such as muscle, fat, and skin. The pharmacokinetic profiles of ochratoxin A in pigs and broilers were also investigated and discussed.

The pharmacokinetic profile of ochratoxin A in the rat after oral and intravenous administration.

A single oral or iv dose (2.5 mg/kg) of ochratoxin A was administered to healthy adult rats. A spectrofluorimetric method was used to determine the toxin level in plasma. The results suggest that the toxin is distributed in two kinetically distinct body compartments. By use of computer techniques, values were assigned to the pharmacokinetic parameters for ochratoxin A in the rat. The half-life of the drug was around 55 hr for either oral or iv administration. Digital computer-simulated curves of the toxin levels in the central and peripheral compartments as well as a total elimination curve were generated. When 14C-ochratoxin A was administered to rats, there were peaks of radioactivity 1 and 6 hr after injection. Ochratoxin alpha was the only metabolite recovered from the cecum and large intestine. Ochratoxin A was excreted via urine and feces, both as the free drug and hydroylzed to ochratoxin alpha; in urine there were five unidentified labeled metabolites. Some of the water-soluble radioactivity was not recovered in the acidic ether extract of the excreta. A hierarchical clustering technique was used to classify the organs in central and peripheral compartments. Muscle, fat, and skin were found to belong to the deep compartment. The residue problem is discussed.