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Biomedical subjects

P Hennebert

Publications and source records attributed to P Hennebert.

At least 19 recordsLinked to original sources
PubMed1990

Polyorchidism: report of three cases and further embryological considerations.

We report 3 new cases of polyorchidism. Review of the literature allows two groups of anatomical variations to be identified: (1) where the Wolffian duct is duplicated longitudinally or absent, and (2) where the two testes are drained by the same epididymis and vas deferens. We postulate that the first group results from a primary anteroposterior division of the genital ridge, whereas the second group is the result of a transverse duplication.

Adolescent↗
PubMed1988

Solubility and diffusion coefficients of gaseous formaldehyde in polymers.

The solubility and diffusion (desorption) coefficients of gaseous formaldehyde in 14 materials have been measured at different temperatures. Cellulose, paper, polyamide (Nylon 6), polyester and natural rubber (latex) show very high values of formaldehyde solubility and very low diffusion coefficients, with a weak or inversed influence of the temperature, leading to the conclusion that a chemical reaction occurs with the formaldehyde. The behaviour of the other polymers follows the classical laws of solubility and diffusion of gases except for silicone rubber which shows two-phase desorption curves.

Biocompatible Materials↗
PubMed1988

Effect of sterilization on osteoinduction. Comparison of five methods in demineralized rat bone.

The aim of this study was to find a safe, effective sterilization method that does not destroy the bone-inductive capacity of demineralized bone implants. Five sterilizing agents were tested in rats. Implants procured and processed under sterile conditions served as controls. New bone formation was evaluated by determining dry weight, calcium content, and Sr-85 incorporation of the induced ossicles. Glutaraldehyde solution, formaldehyde gas, and ethylene oxide destroyed almost all the bone-inductive capacity. Irradiation by 2.5 Mrads Co-60 resulted in a loss of about half of the inductive capacity. Merthiolate (0.18 per cent) was the only sterilizing agent that did not reduce the bone-inductive capacity of the demineralized implants. Because merthiolate is not sporicidal, gamma irradiation appears to be the most appropriate sterilizing agent for demineralized bone in clinical use.

Animals↗
PubMed1987

General solution of the diffusion equation: application to formaldehyde sterilization and desorption of polymers.

A general solution of the diffusion equation for gas in polymers is developed by a numerical method. This solution allows diffusion to be calculated in all cases, by gas desorption after an incomplete adsorption, which is not the case for analytical solutions. When the analytical solutions are valid, both types of solution give identical results. The effect of equivalent sterilization treatment at different temperatures and gas concentrations on formaldehyde residuals in 9 polymers is calculated. High temperature gives lower residual content. Short sterilization times at high gas concentration produce a higher residual content at the end of the adsorption and a lower residual content during desorption than longer sterilization times with lower gas concentration. This is due to sharper gradients of diffusant in the polymer.

Chemical Phenomena↗