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Biomedical subjects

C Dupont

Publications and source records attributed to C Dupont.

At least 343 records · Page 19Linked to original sources
PubMedDate not supplied

Pharmacokinetics of a prodrug thymoxamine: dose-dependence of the metabolite ratio in healthy subjects.

Thymoxamine, a prodrug, is rapidly deacetylated in the plasma to give two phase I metabolites, DMAT and DAT, which are further sulpho- and glucuro-conjugated and then excreted mainly in the urine. In a cross-over study, the dose-dependence of the metabolite ratio was evaluated in nine healthy volunteers after three doses (120, 240, 480 mg) of thymoxamine-HCl. Regardless of the dose, DMAT and its glucuronide were not detected, while the amount of DMAT-sulphate was found to be proportional to the dose administered. Plasma levels of DAT were measurable in only four of the nine subjects after the 480 mg dose and showed great intersubject variability. The pharmacokinetics of both DAT-sulphate and DAT-glucuronide were dose-dependent. As the dose increased, the proportion of DAT undergoing sulphatation decreased; this saturation was compensated by glucuronidation.

Adult↗
PubMedDate not supplied

Rectosigmoidoscopic findings during isolated rectal bleeding in the neonate.

This study describes a group of 34 infants under 1 1/2 months of age presenting with isolated rectal bleeding not related to hemorrhagic disease of the newborn or to campylobacter infection and with spontaneously favorable evolution. Systematic rectosigmoidoscopy showed the presence of mucosal alterations in the form of either longitudinally stretched ecchymoses lying on a normal mucosa or diffuse ecchymotic patches dispersed on a congestive and friable mucosa, rarely associated to visible micro-ulcerations. Biopsies showed mucosal hemorrhage, capillary vessel congestion, and epithelial erosions, as well as various grades of inflammation. Clinical data indicate that this hemorrhagic colitis is a heterogeneous group where dietary protein intolerance may account for some cases.

Enterocolitis, Pseudomembranous↗
PubMedDate not supplied

Dual-probe pH monitoring for the assessment of gastroesophageal reflux in the course of chronic hoarseness in children.

The purpose of our study was to assess gastroesophageal reflux (GER) by dual-probe pH monitoring in children suffering from chronic hoarseness for more than six months. Seventeen children (aged between 2 and 12 years, 10 boys and 7 girls) were enrolled. All children underwent a laryngoscopy and a 24-hour dual-probe pH monitoring. At both sensor, distal and proximal esophageal, a pathological GER was defined as the presence of episodes of acid reflux with pH < 4 during a fraction of the total recording time greater than 5.2 percent. The computer considered the child was supine when asleep and upright when awake. Laryngoscopy revealed interarytenoid erythema and/or edema with vocal cord nodules or granulomas in 13 cases (76.4%), isolated vocal nodules or granulomas in three cases (17.6%) and a normal appearance in one case (5.8%). At both sensors, the majority of refluxes occurred when the child was upright, as analyzed by the percentage of time the intra-esophageal pH was below four (% time pH < 4), number of refluxes, reflux episodes/hour and longest reflux episode, p < 0.05 between upright and supine for each parameter. The median total % time pH < 4 on the proximal and distal probes was respectively 1.62 percent (95% CI 1.50-3.79) and 11.49 percent (95% CI 8.81-27.17), p < 0.0003. Among the 17 hoarse children, a pathological GER was observed in 12 (70.5%) at the distal sensor and in three (17.5%) at both sensors. Among the 16 hoarse children with abnormal findings on laryngoscopy, two (12.5%) had diagnosed pathological GER at the proximal and 11 (68.7%) at the distal sensor. The only child with normal findings on laryngoscopy exhibited a pathological GER at both sensors. Our results suggest that chronic hoarseness is associated with a pathological GER. The majority of these documented refluxes occurred when the child was awake.

Child↗
PubMedDate not supplied

[Vip in human neonates and infants. As measured by radioimmunoassay and radioreceptorassay (author's transl)].

The Vasoactive Intestinal Peptide (VIP) was assayed in the gut of human neonates and premature infants immediately after death or surgery. In these conditions, values ranged between 150 and 740 ng/g of bioled tissue. The implication of VIP in Vermer-Morrison syndrome is further assessed by the correlation between clinical symptomatology and plasma VIP levels. The immunoassayable VIP (IA-VIP) extracted from normal gut or tumor is shown to fully interact with specific receptor for VIP in liver. This fact suggests the biological potency of IA-VIP.

Biological Assay↗
PubMedDate not supplied

[Skin permeability modifications in vivo in men after application of surfactants. Importance of experimental conditions in the determination of transepidermal insensible water loss].

Trans Epidermal Water Loss (TEWL) was used to evaluate the skin permeability modifications in vivo in man with an evaporimeter Servo Med. Measurements were performed on the forearms of healthy volunteers. At first, influence of the stabilization of the subjects and reproducibility of measurements between morning and evening, and from day to day were determined. The effect on the stratum corneum of 3 surfactants (Tween 60, sodium dodecyl sulfate and cetyl trimethyl ammonium bromide) was studied. The results showed a variability of TEWL during the first 30 minutes, but there were no significant chronobiologic variations. After treatment by surfactants, TEWL increase was in relation with the importance of the aggression and the time after the end of the treatment. 3 hours were necessary to be sure that TEWL increase was only due to surfactants.

Adult↗
PubMedDate not supplied

[Pseudo-Hirschsprung's disease (author's transl)].

Eight children with pseudo-Hirschsprung's disease are reported. They can be divided into three groups: alimentary ganglioneuromatosis, schwann cell hyperplasia and those with normal appearance by stantard histology. In view of the heterogeneity, histology cannot predict the extent or the prognosis of the disease. Several biopsies at various levels of the alimentary tract and the use of advanced techniques are necessary to assess fully the extent and the type of the lesion and whether it is congenital or acquired. The majority of pseudo-Hirschsprung's disease tend to affect most of alimentary tract, which may lead to the formation of stagnant loops with all their risks. Treatment includes ileostomy, continuous hypoallergenic oral feeding, and manual expression several times a day.

Child↗