Represented by 137 populations in 1978, A. pallipes is now almost completely restricted to only one department, with 45 populations recorded, representing a decrease of 68% of the population number in 25 years, with a loss of 40% of populations in the last 6 years. Most of the disappearances of crayfish are unexplained. For the 22 others, the main reasons of the disappearance of indigenous crayfish populations were due to (1) habitat destruction by channelisation, (2) decrease of water quality by use of agricultural chemicals, (3) the construction of ponds or lakes changing the physical and chemical parameters of brooks inhabited by indigenous crayfish, (4) the introduction of non-indigenous species, mainly P. leniusculus and recently (5) crayfish plague implicated and characterized in the disappearance of two populations, two additional ones being suspected.Introduced in 1978 in Vienne department, P. leniusculus has now been found in 28 locations. First record of P. clarkii was in 1988 in Charente-Maritime department; since it has spread in most of the hydrographic basin of this department. La plupart des disparitions de populations sont inexpliquées. Pour les disparitions dont les causes peuvent être présumées ou observées, on trouve par ordre décroissant d'importance : (1) la destruction de l'habitat (recalibrage), (2) la diminution de la qualité de l'eau par utilisation de produits chimiques pour l'agriculture, (3) la construction de mares ou d'étangs qui changent les paramètres physico-chimiques des cours d'eau (4) l'introduction d'écrevisses non indigènes, principalement P. leniusculus et récemment (5) la peste de l'écrevisse qui a été caractérisée dans la disparition de 2 populations, et suspectée dans 2 autres cas.Introduite en 1978 dans le département de la Vienne, P. leniusculus est présente dans 28 sites (de ce département). Les premières observations de P. clarkii datent de 1988 en Charente-Maritime, depuis elle s'est étendue à la plupart des bassins hydrographiques de ce département.

Restenosis remains the major limitation of coronary angioplasty. The objective of this study was to develop microspheres able to be delivered at the angioplasty site for long-term drug release and to test their effects in a model of balloon angioplasty. Polylactic-co-glycolide acid microspheres (5-10 microm in diameter) were prepared by using an oil-in-water emulsion-solvent evaporation method. In vitro experiments with hydrocortisone-loaded microspheres revealed a hydrocortisone release for 4 weeks. We studied the in vivo effect of injection of microspheres into the arterial wall of New Zealand White rabbits by using a perforated balloon. Deep penetration of microspheres in the arterial wall was documented immediately after angioplasty. Intimal hyperplasia was assessed in iliac arteries 4 weeks after angioplasty. The morphometric analysis was performed in four groups of animals; the first group was subjected only to conventional angioplasty (control, n = 10), whereas the other three groups after conventional angioplasty were received perforated balloon angioplasty with saline (n = 10), microspheres (n = 10), or hydrocortisone-loaded microspheres (n = 7). Intramural injection of saline did not induce greater intimal hyperplasia compared with control (0.17 +/- 0.03 vs. 0.18 +/- 0.03 mm2, respectively). Microspheres injection was associated with a trend toward a greater degree of intimal hyperplasia that did not reach statistical significance. Hydrocortisone-loaded microspheres were associated with a significant reduction in intimal hyperplasia compared with unloaded microspheres (0.16 +/- 0.02 vs. 0.26 +/- 0.03 mm2, respectively). The polylactic-co-glycolide acid microspheres are well tolerated, easily injected into the arterial wall, and the increase of intimal hyperplasia is easily inhibited by release of hydrocortisone for 4 weeks after initial injury.

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