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J Dupuy

Publications and source records attributed to J Dupuy.

26 records · Page 2Linked to original sources
PubMed1993

Thermostability of Fumonisin B(1), a Mycotoxin from Fusarium moniliforme, in Corn.

Fumonisin B(1) (FB(1)) is a mycotoxin from Fusarium moniliforme that is frequently associated with corn. Thermal treatments are used in many processes concerning this cereal and its derivatives. The thermostability of this toxin in dry contaminated corn, resulting from F. moniliforme culture, was studied in different time-temperature combinations. FB(1) was quantified by instrumentalized thin-layer chromatography after a two-step sequential development and postchromatographic derivatization by p-anisaldehyde. The identity of FB(1) in extracts, before and after heat treatments, was confirmed by high-pressure liquid chromatography. For each temperature, the natural logarithm of the ratio of resulting FB(1) on initial content (In C/C(0)) is linearly correlated to exposure time. The calculated half-lives (L(50)), corresponding to the 50% value, were 10 min, 38 min, 175 min, and 8 h at 150, 125, 100, and 75 degrees C, respectively. There is a linear relationship between calculated L(50)s on a logarithmic scale and temperature. Therefore FB(1) is not significantly destroyed by the main drying processes of corn or thermal treatments used for its derivatives. Other associated means are required for detoxification.

Journal Article↗
PubMed1993

The mycotoxin, deoxynivalenol, delays gastric emptying through serotonin-3 receptors in rodents.

The effects of the trichotecene mycotoxin, deoxynivalenol, on gastric emptying and intestinal propulsion in mice and rats and gastrointestinal myoelectrical activity in rats were investigated. Gastric emptying and intestinal transit were evaluated after gavage with a milk meal containing a marker (51CrO4Na2) and radio-activity was counted in the stomach and 10 segments of the small intestine. The myoelectrical activity of the antrum, duodenum and jejunum was assessed by implanting electrodes for long-term electromyographic recordings. Deoxynivalenol given orally (50-1000 micrograms/kg) but not i.c.v. (5 micrograms/kg) 10 min before the test meal inhibited gastric emptying in a dose-related manner. Intestinal propulsion was reduced for the highest dose (1000 micrograms/kg) only. The inhibition of gastric emptying induced by deoxynivalenol was antagonized by ondansetron and granisetron given s.c. (50 micrograms/kg) but not by ondansetron i.c.v. (10 micrograms/kg). Metoclopramide, domperidone (1 mg/kg s.c.), methysergide, ritanserin and cisapride (2 mg/kg s.c.) did not modify the deoxynivalenol-induced inhibition of gastric emptying. In rats, gavage with a 2.5-ml milk meal increased the frequency of antral spike bursts from 1.9 +/- 0.9/min in the fasted state to 4.7 +/- 0.4/min and disrupted intestinal migrating motor complexes for 84.9 +/- 10.8 min. Oral administration of deoxynivalenol (50-100 micrograms/kg) 10 min before the meal did not modify the frequency of antral spike bursts but induced migrating motor complexes on the small intestine after the meal. This effect was reversed by ondansetron (10 micrograms/kg s.c.). It was concluded that, in rodents, deoxynivalenol inhibits gastric emptying by inducing intestinal migrating motor complexes through a peripheral action at the serotonin-3 receptors.

Animals↗
PubMed1988

Radiation port dermatophytosis.

We report two cases in which dermatophytic infection developed almost entirely within a radiation field mimicking an acute radiation effect. Radiotherapists and dermatologists should be aware of this possibility and be able to differentiate it from radiation dermatitis. Topical antifungal agents are the recommended treatment after diagnosis is established.

Adult↗
PubMed1987

Persistence of retinal dopamine cells in the degenerated eye of the cave salamander, Proteus anguinus L.

The Proteus anguinus L. is a blind cave perennibranch amphibian whose visual system undergoes an important morphogenetic degeneration in adulthood. The eyeball becomes atrophied and disappears under the fat tissue of the head. However, a retina can still be identified and a photophobic behavior of the animal indicates a remaining photosensitivity. In the oldest animal observed, some photoreceptor cells are still present as well as other types of retinal neurons. Characteristic synapses are observed in both the inner and outer plexiform layers. Dopaminergic amacrine cells, with processes in the inner plexiform layer, can be identified by their tyrosine-hydroxylase immunoreactivity. Taken together, these results indicate a possible functional role of the remaining retina. Since dopamine is especially involved in light adaptation from darkness, the residual retina could act in triggering the turning behavior of Proteus in response to lightening.

Animals↗
PubMedDate not supplied

Determination of selamectin in dog plasma by high performance liquid chromatography with automated solid phase extraction and fluorescence detection.

A method is described for the determination of selamectin in dog plasma, using High-Performance Liquid Chromatography (HPLC) with fluorescence detection (excitation and emission wavelengths fixed at 355 and 465 nm, respectively). The fluorescent derivative was obtained by condensation reaction with trifluoroacetic anhydride and N-methylimidazole. The method employs 1 mL plasma samples and gives linear calibration graphs (r = 0.999) over the concentration range studied (0.5-50 ng mL(-1)). Automatic solid phase extraction using the benchmate procedure was used for sample preparation. This method permits the determination of selamectin at levels as low as 0.1 ng mL(-1) and its suitability was demonstrated by a pharmacokinetic study on a dog receiving the therapeutic dose (Spot-on administration).

Animals↗