PubMed Health⌕ Search

Biomedical subjects

E Perrier

Publications and source records attributed to E Perrier.

27 records · Page 2Linked to original sources
PubMed1997

A skin equivalent model for cosmetological trials: an in vitro efficacy study of a new biopeptide.

The European Community directive, imposing that effects claimed for cosmetic actives must be validated using non-animal procedures, has stimulated the use of in vitro models for pharmacotoxicological trials. In this paper, an efficacy study of a new biopeptide, a hydrolysate obtained by fermentation of milk proteins, was performed using an in vitro skin equivalent (SE). This SE is obtained by seeding normal human keratinocytes onto a dermal equivalent comprising a collagen-glycosaminoglycan(GAG)-chitosan porous matrix populated by normal human fibroblasts, which neosynthesize their own extracellular matrix (ECM). A gel containing 2% milk biopeptide was applied topically (10 microliters) every 2 days during 15 days. Subsequent investigations of the biopeptide effects were based on morphological criteria after histological analysis and on synthesis of ECM components. Collagen and GAG synthesis were measured by tritiated proline, glucosamine and Na2(35)SO4 incorporation. Qualitatively, the histological features of the biopeptide-treated SEs showed a thicker epidermis than the untreated control SEs, where only a few layers of stratum corneum were observed. The dermal porous matrix seems to be more filled by neosynthesized ECM than the control. Quantitatively, milk biopeptide treatment induced a significant activation of hyaluronic acid (+46%) and sulfated GAG (+53%) synthesis, whereas only non-significant increases of total protein and collagen synthesis were observed (Student's test, p < 0.001).

Animal Testing Alternatives↗
PubMed1991

Utilisation of the method of Kalman filtering for performing the on-line computation of background metabolism in the free-moving, free-feeding rat.

Since 1984, we have utilized a metabolic device in which activity and food intake are measured at 10-second intervals, in relation to the respiratory exchanges in the rat (indirect calorimetry). To solve the problem of quantifying precisely the metabolic cost of activity, we have developed models of the diffusion of the cells' respiratory exchanges in the rat and in the metabolic chamber until they reached the gas analyzers. The predictions of these models have been used to feed a process of numerical filtering that computed an estimation of the energy cost of activity, and an estimation of the value of the part of the total metabolism that was not due to the cost of the muscular contractions. This later component of metabolism has been named background metabolism to be clearly distinguished from the true resting metabolism measured during resting periods. In this paper, two models of diffusion of the cell's respiratory exchanges are described, and examples of the computation of the background metabolism by the process of Kalman filtering are shown.

Algorithms↗
PubMedDate not supplied

An in vitro, ex vivo, and in vivo demonstration of the lipolytic effect of slimming liposomes: An unexpected alpha(2)-adrenergic antagonism.

Most of the slimming products already developed for cosmetic applications did not result from strategies that integrate whole lipolysis-regulating mechanisms. We thus focused our attention on a more complete integration of these mechanisms and we developed slimming liposomes (SLC) containing two micro-circulation activators, i.e., esculoside and Centella asiatica extracts, one phosphodiesterase inhibitor, i.e., caffeine, and one fatty acid-beta oxidation activator, i.e., L-carnitine. The validity of our approach was assessed through (a) in vitro tests demonstrating that SLC induced a dramatic increase in the cyclic adenosine monophosphate (cAMP) content in human adipocytes, with a subsequent rise in the nonesterified fatty acids (NEFA) content of human adipocyte incubation medium, and (b) in vivo studies showing that SLC could provide an actual potent slimming effect on human volunteers. Moreover, we give here, through binding experiments, the unambiguous demonstration that SLC is able to antagonize the alpha(2)-adrenergic receptor that is known to reduce intracellular AMPc content and, subsequently, to down-regulate lipolysis. This alpha(2)-adrenergic antagonism has never been reported for any component of SLC, and this work is the first demonstration of the alpha(2)-adrenergic antagonism of such a combination of active liposome compounds.

Adipocytes↗
PubMedDate not supplied

[Noradrenergic hypothesis in anorexia nervosa: prospective study using beta-stimulant therapy].

We assumed for this study that beta-stimulants could efficient for the treatment of anorexia nervosa not with direct action upon the center of hunger or upon the secretion of insulin but by stimulating the norepinephrine way which is characterized by a function hypotrophy as it is the case in some affective disorder. This experiment was homogenously performed with seven patients. It then presents an encouraging prospective value.

Adolescent↗