Salicylsalicylic acid causes less gastroduodenal mucosal damage than enteric-coated aspirin

The gastroduodenal mucosal damage caused by aspirin and nonsteroidal antiinflammatory drugs is a common clinical problem. We compared two medications designed to diminish mucosal damage: enteric-coated aspirin and salicylsalicylic acid (salsalate). Ten healthy volunteers were randomized to receive either 1.5 g salsalate twice a day or 650 mg enteric-coated aspirin four times a day for six days and were then crossed over to the other drug after a one-week medication-free period. Endoscopic inspection of gastroduodenal mucosa was performed at entry and again after six days of drug therapy for each medicine. Mean serum salicylate concentrations taken before the morning drug dose were 11.2 mg/dl for enteric-coated aspirin and 18.1 mg/dl for salsalate. Only one of 10 subjects receiving salsalate developed mild (grade 1) mucosal damage while six of 10 receiving enteric-coated aspirin developed moderate to severe damage (grade 2–3) (P= 0.01 ). Symptoms were mild in both groups. We conclude that salsalate causes less gastroduodenal mucosal damage than enteric-coated aspirin .Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/44409/1/10620_2005_Article_BF01536056.pd

Adaptive Traits Are Maintained on Steep Selective Gradients despite Gene Flow and Hybridization in the Intertidal Zone

Gene flow among hybridizing species with incomplete reproductive barriers blurs species boundaries, while selection under heterogeneous local ecological conditions or along strong gradients may counteract this tendency. Congeneric, externally-fertilizing fucoid brown algae occur as distinct morphotypes along intertidal exposure gradients despite gene flow. Combining analyses of genetic and phenotypic traits, we investigate the potential for physiological resilience to emersion stressors to act as an isolating mechanism in the face of gene flow. Along vertical exposure gradients in the intertidal zone of Northern Portugal and Northwest France, the mid-low shore species Fucus vesiculosus, the upper shore species Fucus spiralis, and an intermediate distinctive morphotype of F. spiralis var. platycarpus were morphologically characterized. Two diagnostic microsatellite loci recovered 3 genetic clusters consistent with prior morphological assignment. Phylogenetic analysis based on single nucleotide polymorphisms in 14 protein coding regions unambiguously resolved 3 clades; sympatric F. vesiculosus, F. spiralis, and the allopatric (in southern Iberia) population of F. spiralis var. platycarpus. In contrast, the sympatric F. spiralis var. platycarpus (from Northern Portugal) was distributed across the 3 clades, strongly suggesting hybridization/introgression with both other entities. Common garden experiments showed that physiological resilience following exposure to desiccation/heat stress differed significantly between the 3 sympatric genetic taxa; consistent with their respective vertical distribution on steep environmental clines in exposure time. Phylogenetic analyses indicate that F. spiralis var. platycarpus is a distinct entity in allopatry, but that extensive gene flow occurs with both higher and lower shore species in sympatry. Experimental results suggest that strong selection on physiological traits across steep intertidal exposure gradients acts to maintain the 3 distinct genetic and morphological taxa within their preferred vertical distribution ranges. On the strength of distributional, genetic, physiological and morphological differences, we propose elevation of F. spiralis var. platycarpus from variety to species level, as F. guiryi