Preparation of an oakmoss absolute with reduced allergenic potential.

Synopsis Oakmoss absolute, an extract of the lichen Evernia prunastri, is known to cause allergenic skin reactions due to the presence of certain aromatic aldehydes such as atranorin, chloratranorin, ethyl hematommate and ethyl chlorohematommate. In this paper it is shown that treatment of Oakmoss absolute with amino acids such as lysine and/or leucine, lowers considerably the content of these allergenic constituents including atranol and chloratranol. The resulting Oakmoss absolute, which exhibits an excellent olfactive quality, was tested extensively in comparative studies on guinea pigs and on man. The results of the Guinea Pig Maximization Test (GPMT) and Human Repeated Insult Patch Test (HRIPT) indicate that, in comparison with the commercial test sample, the allergenicity of this new quality of Oakmoss absolute was considerably reduced, and consequently better skin tolerance of this fragrance for man was achieved.

Experimental study of biliary endoprosthesis efficiency.

Insertion of biliary prosthesis permits palliative drainage; unfortunately, cholangitis and clotting induced a large amount of side effects. We set up an experimental model with a view to testing in vitro efficiency of available stents, then we designed a new prosthesis with improved mechanical performance.

Determination of water-insoluble cell walls in feeds: interlaboratory study.

A collaborative study was conducted to test a new rapid procedure for determination of water-insoluble cell wall (WICW) content in feeds. In the method, starch is solubilized near boiling temperature with Termamyl, a heat-stable alpha-amylase, and proteins are solubilized at 40 degrees C with sodium dodecylsulfate and Pronase. Then, the organic matter of the residue is determined by incineration. Three hours were required to treat 12 different samples, including solubilization treatments, filtrations, and rinses. Eleven unknown products including 9 common feedstuffs of various origin and 2 mixed diets for poultry were analyzed by 7 analysts in France. Coefficients of variation ranged from 2.3 to 6.1%. The results were compared to those for water-insoluble dietary fiber (WIDF), total dietary fiber, and neutral detergent fiber. Agreement was best with the water-insoluble dietary fiber procedure. For most samples, the ratios of WIDF/WICW ranged from 0.981 to 0.842. The differences between WICW and WIDF values correspond to cell wall protein which is accounted for in WICW, but not in WIDF.