Metatranscriptomics reveal differences in in situ energy and nitrogen metabolism among hydrothermal vent snail symbionts

Despite the ubiquity of chemoautotrophic symbioses at hydrothermal vents, our understanding of the influence of environmental chemistry on symbiont metabolism is limited. Transcriptomic analyses are useful for linking physiological poise to environmental conditions, but recovering samples from the deep sea is challenging, as the long recovery times can change expression profiles before preservation. Here, we present a novel, in situ RNA sampling and preservation device, which we used to compare the symbiont metatranscriptomes associated with Alviniconcha, a genus of vent snail, in which specific host–symbiont combinations are predictably distributed across a regional geochemical gradient. Metatranscriptomes of these symbionts reveal key differences in energy and nitrogen metabolism relating to both environmental chemistry (that is, the relative expression of genes) and symbiont phylogeny (that is, the specific pathways employed). Unexpectedly, dramatic differences in expression of transposases and flagellar genes suggest that different symbiont types may also have distinct life histories. These data further our understanding of these symbionts' metabolic capabilities and their expression in situ, and suggest an important role for symbionts in mediating their hosts' interaction with regional-scale differences in geochemistry

Jones fracture. Surgical versus nonsurgical treatment

Sixty-three patients with 66 transverse and short oblique fractures of the proximal shaft of the fifth metatarsal bone (Jones fracture) were evaluated an average of five years (range, one to ten years) after the injury. There were 27 acute fractures and 39 chronic, or stress, fractures. The primary treatment was surgical for one third of the injuries and nonsurgical for the others. Surgical treatment consisted of the insertion of medullary screws. Nonsurgical treatment consisted of the application of either a plaster cast or an elastic bandage. Almost one fourth of the fractures treated nonsurgically later had to be treated surgically because of delayed unions or refractures. Late surgery was required in 12% of acute fractures and in 50% of chronic fractures with sclerosis narrowing the medullary canal. Irrespective of the primary treatment, all the patients had full function at the time of the follow-up evaluation, and no nonunions were diagnosed