Characterization of the cluster MabR prophages of Mycobacterium abscessus and Mycobacterium chelonae.

Mycobacterium abscessus is an emerging pathogen of concern in cystic fibrosis and immunocompromised patients and is considered one of the most drug-resistant mycobacteria. The majority of clinical Mycobacterium abscessus isolates carry 1 or more prophages that are hypothesized to contribute to virulence and bacterial fitness. The prophage McProf was identified in the genome of the Bergey strain of Mycobacterium chelonae and is distinct from previously described prophages of Mycobacterium abscessus. The McProf genome increases intrinsic antibiotic resistance of Mycobacterium chelonae and drives expression of the intrinsic antibiotic resistance gene, whiB7, when superinfected by a second phage. The prevalence of McProf-like genomes was determined in sequenced mycobacterial genomes. Related prophage genomes were identified in the genomes of 25 clinical isolates of Mycobacterium abscessus and assigned to the novel cluster, MabR. They share less than 10% gene content with previously described prophages; however, they share features typical of prophages, including polymorphic toxin-immunity systems.

Development of the CAVEMAN Human Body Model: Validation of Lower Extremity Sub-Injurious Response to Vertical Accelerative Loading.

Improving injury prediction accuracy and fidelity for mounted Warfighters has become an area of focus for the U.S. military in response to improvised explosive device (IED) use in both Iraq and Afghanistan. Although the Hybrid III anthropomorphic test device (ATD) has historically been used for crew injury analysis, it is only capable of predicting a few select skeletal injuries. The Computational Anthropomorphic Virtual Experiment Man (CAVEMAN) human body model is being developed to expand the injury analysis capability to both skeletal and soft tissues. The CAVEMAN model is built upon the Zygote 50th percentile male human CAD model and uses a finite element modeling approach developed for high performance computing (HPC). The lower extremity subset of the CAVEMAN human body model presented herein includes: 28 bones, 26 muscles, 40 ligaments, fascia, cartilage and skin. Sensitivity studies have been conducted with the CAVEMAN lower extremity model to determine the structures critical for load transmission through the leg in the underbody blast (UBB) environment. An evaluation of the CAVEMAN lower extremity biofidelity was also carried out using 14 unique data sets derived by the Warrior Injury Assessment Manikin (WIAMan) program cadaveric lower leg testing. Extension of the CAVEMAN lower extremity model into anatomical tissue failure will provide additional injury prediction capabilities, beyond what is currently achievable using ATDs, to improve occupant survivability analyses within military vehicles.

Thin film processing using S-layer proteins: biotemplated assembly of colloidal gold etch masks for fabrication of silicon nanopillar arrays.

We explored the bionanofabrication of silicon nanopillar structures using ordered gold nanoparticle arrays generated from microbial surface layer (S-layer) protein templates. The S-layer template used for these thin film processing experiments was isolated from the Gram-positive bacterium Deinococcus radiodurans. In this preliminary work, S-layers preimmobilized onto chemically modified silicon substrates were initially used to template the fabrication of a nanolithographic hard mask pattern comprised of a hexagonally ordered array of 5-nm gold nanoparticles (lattice constant=18 nm). Significantly, the use of the biotemplated gold nanoparticle mask patterns in an inductively coupled plasma (ICP) etching process successfully yielded silicon nanopillar structures. However, it was found that the resultant nanopillars (8-13 nm wide at the tip, 15-20 nm wide at half-height, 20-30 nm wide at the base, and 60-90 nm tall) appeared to lack any significant degree of translational ordering. The results suggest that further studies are needed in order to elucidate the optimal plasma processing parameters that will lead to the generation of long-range ordered arrays of silicon-based nanostructures using S-layer protein templates.

Midterm follow-up of a single-center experience of endovascular repair of abdominal aortic aneurysms with use of the Talent stent-graft.

PURPOSE: To review the midterm results of endovascular aneurysm repair (EVAR) of abdominal aortic aneurysms (AAAs) with the Talent stent-graft. MATERIALS AND METHODS: All patients who underwent EVAR of AAAs with Talent stent-grafts from February 1998 to April 2002 at a single institution were monitored for a minimum of 2 years or until an endpoint of death or rupture was reached. RESULTS: There were 68 eligible patients, who were monitored for a mean period of 39 months (range, 24-72 months). Forty-nine (72.9%) were alive at 2 years; among the 19 deaths, two resulted from aneurysm rupture and the other 17 were unrelated to EVAR. There was one immediate conversion to open repair and five primary proximal endoleaks; the remaining 62 patients (91.2%) all had a technically successful procedure. There were 33 endoleaks during follow-up: 23 (69.7%) were treated conservatively and 10 (30.3%) underwent secondary intervention in the form of embolization (n=2), attempted embolization (n=2), endovascular stent-graft placement (n=3), combined stent-graft placement and embolization (n=1), or surgical conversion (n=2). Overall, there were five persistent endoleaks, and the remaining patients were free of endoleak at their last review or endpoint. Three stent-grafts migrated and required further endovascular intervention. Wire fracture was seen in two stents but presented no clinical sequelae. There was one case of graft limb thrombosis that required surgical thrombectomy. CONCLUSIONS: EVAR of AAAs with use of the Talent stent-graft is a promising and acceptable alternative to open surgery. Our 30-day mortality rate of zero compares extremely well with historical data from open surgery and the findings of more recently published trials. The risk of endoleak and uncertainty over durability require long-term surveillance.