The impact of nitric oxide toxicity on the evolution of the glutathione transferase superfamily: A proposal for an evolutionary driving force

Background: Why do ancestral GSTs utilize cysteine/serine as catalytic residues, whereas more recently evolved GSTs utilize tyrosine? Results: Only the more recently evolved GSTs display enough affinity to bind and make harmless the toxic DNDGIC (a natur

The Roman Bridge: a "double pulley – suture bridges" technique for rotator cuff repair

<p>Abstract</p> <p>Background</p> <p>With advances in arthroscopic surgery, many techniques have been developed to increase the tendon-bone contact area, reconstituting a more anatomic configuration of the rotator cuff footprint and providing a better environment for tendon healing.</p> <p>Methods</p> <p>We present an arthroscopic rotator cuff repair technique which uses suture bridges to optimize rotator cuff tendon-footprint contact area and mean pressure.</p> <p>Results</p> <p>Two medial row 5.5-mm Bio-Corkscrew suture anchors (Arthrex, Naples, FL), which are double-loaded with No. 2 FiberWire sutures (Arthrex, Naples, FL), are placed in the medial aspect of the footprint. Two suture limbs from a single suture are both passed through a single point in the rotator cuff. This is performed for both anchors. The medial row sutures are tied using the double pulley technique. A suture limb is retrieved from each of the medial anchors through the lateral portal, and manually tied as a six-throw surgeon's knot over a metal rod. The two free suture limbs are pulled to transport the knot over the top of the tendon bridge. Then the two free suture limbs that were used to pull the knot down are tied. The end of the sutures are cut. The same double pulley technique is repeated for the other two suture limbs from the two medial anchors, but the two free suture limbs are used to produce suture bridges over the tendon, by means of a Pushlock (Arthrex, Naples, FL), placed 1 cm distal to the lateral edge of the footprint.</p> <p>Conclusion</p> <p>This technique maximizes the advantages of two techniques. On the one hand, the double pulley technique provides an extremely secure fixation in the medial aspect of the footprint. On the other hand, the suture bridges allow to improve pressurized contact area and mean footprint pressure. In this way, the bony footprint in not compromised by the distal-lateral fixation, and it is thus possible to share the load between fixation points. This maximizes the strength of the repair and provides a barrier preventing penetration of synovial fluid into the healing area of tendon and bone.</p

Stem cells and tendinopathy: state of the art from the basic science to clinic application

Management of tendinopathies and tendon rupture is challenging. In the last few decades, several emerging strategies including tissue engineering with mesenchymal stem cells have been proposed to enhance tendon healing. They hold the promise to yield more successful outcomes for the management of patients with tendon pathology. Current in vitro studies support the application of these cell-based therapies for the regeneration of tendon tissues. However, these cell-based strategies have been investigated only in pre-clinical studies and the role of stem cells needs to be confirmed. We performed a review of the literature to focus on actual knowledge and the future perspectives of stem cells for tendon regeneration and tendon engineerin

Intramedullary nailing for lower limb polyostotic fibrous dysplasia in children: a Long-term follow-up study

Background: In children, intramedullary nailing (IN) has been proposed as the best treatment when the femur and tibia are totally affected by fibrous dysplasia (FD). However, in younger children IN must be repeated to maintain stabilization of the affected skeletal segment during growth. We report the long-term results in a cohort of patients in whom more than two-thirds of cases had IN repeated during growth. Methods: Twenty-nine femurs and 14 tibias totally affected by FD were treated by IN in 21 patients with polyostotic FD and McCune-Albright syndrome. Thirteen patients with 35 femoral and tibial deformities had a painful limp whereas 8 presented fractures. The patients had their first IN at a mean age of 9.26±2.68 years (range: 4 to 14 y). IN was repeated during growth in the younger patients, and all the patients underwent a mean of 2.13 femoral and 1.50 tibial IN per limb. The last IN was performed at a mean age of 16.42±1.95 years (range: 11 to 19 y). Titanium elastic nails and adult humeral nails were used in younger children, whereas adult femoral cervicodiaphyseal and interlocking tibial nails were used in older children and adolescents. At the latest follow-up, the patients were evaluated with a clinicoradiographic scale. All the data were statistically analyzed. Results: The mean length of follow-up from the last IN was 6.47±3.10 years (range: 3 to 14 y), and the mean age of the patients at follow-up was 22.85±3.53 years (range: 14 to 29 y) when lower limbs were fully grown in all but 1 patient. Satisfactory long-term results were obtained in about 81% of our patients, while complications occurred in 32.5% of the 43 cases. Conclusion: Lower limb IN-that was repeated in younger children during growth-provided satisfactory long-term results in most of our patients, with fracture and deformity prevention and pain control, regardless of the high rate of complications that mainly affected the femoral cases. Missing scheduled follow-ups was the main predictor of a poor result. Level of evidence: Level IV-case series

Soft tissue tenodesis of the long head of the biceps tendon associated to the Roman Bridge repair

Abstract Background Rotator cuff tears are frequently associated with pathologies of the long head of the biceps tendon (LHBT). Tenotomy and tenodesis of the LHBT are commonly used to manage disorders of the LHBT. Methods We present an arthroscopic soft tissue LHBT tenodesis associated with a Roman Bridge (double pulley – suture bridges) repair Results Two medial row 5.5-mm Bio-Corkscrew suture anchors (Arthrex, Naples, FL), double-loaded with No. 2 FiberWire sutures (Arthrex, Naples, FL), are placed in the medial aspect of the footprint. A shuttle is passed through an anterior point of the rotator cuff and through the LHBT by means of a Penetrator or a BirdBeak suture passer (Arthrex, Naples, FL). A tenotomy of the LHBT is performed. All the sutures from the anteromedial anchor are passed through a single anterior point in the rotator cuff using a shuttle technique. All the sutures from the posteromedial anchor are passed through a single posterior point in the rotator cuff. The sutures in the medial row are tied using the double pulley technique. A suture limb is retrieved from each of the medial anchors and manually tied as a six-throw surgeon's knot over a metal rod. The two free suture limbs are pulled to transport the knot over the top of the tendon bridge. The two free suture limbs are then used to produce suture bridges over the tendon, using a Pushlock (Arthrex, Naples, FL), placed 1 cm distal to the lateral edge of the footprint. The same double pulley – suture bridges technique is repeated for the other two suture limbs from the two medial anchors. Conclusion This technique allows to perform a double pulley – suture bridges repair for a rotator cuff tear, associated with a soft tissue tenodesis for the management of LHBT pathology. The tenodesis of the LHBT is performed just with the passage of a shuttle inside the LHBT, after passing it through the anterior portion of the rotator cuff, with successive detachment of the LHBT from the glenoid. It is a technically easy procedure which can be performed relatively quickly, and does not require additional fixation.</p

Clinical results and complication rates of lower limb lengthening in paediatric patients using the PRECICE 2 intramedullary magnetic nail: a multicentre study

Implantable intramedullary nail lengthening devices (e.g., PRECICE 2 system) have been proposed as alternative method to external fixation for lower limb lengthening surgery. The aim of this study was to analyse our outcomes and complications using the PRECICE 2 (P2) nail system and review them in light of the existing literature. A retrospective multicentre study was conducted on patients &lt;18 years, who were treated for limb lengthening using the P2 system. The inclusion criteria were a limb length discrepancy &gt;= 30 mm and a follow-up &gt;= 6 months after the end of treatment. A total of 26 (15 males) patients were included, average age was 14.7 +/- 2.3 years; 26 nails (21 femur, 5 tibia) were implanted. The average goal lengthening was 49.4 +/- 12.4 mm, while average achieved lengthening was 44.4 +/- 11.6 mm. Average distraction and consolidation indexes were 11.9 +/- 2.1 days/cm and 25.1 +/- 8.1 days/cm, respectively. Nail accuracy and reliability were 91.1% and 88.5%, respectively. A total of five problems (joint contractures), one obstacle (femur fracture) and three complications (hip joint subluxation, deep infection and nail running back) were encountered. The P2 nail system is a valid alternative to external fixator for limb lengthening in young patients with no significant angular or rotation deformities. Our study confirms a favourable complication rate and available evidence from literature suggests a lower complication rate than external fixator systems. Nevertheless, surgeons should keep a watchful eye on risk of joint subluxation and mechanical complications with intramedullary lengthening

Tryptorubin A: A Polycyclic Peptide from a Fungus-Derived Streptomycete

Fungus-growing ants engage in complex symbiotic relationships with their fungal crop, specialized fungal pathogens, and bacteria that provide chemical defenses. In an effort to understand the evolutionary origins of this multilateral system, we investigated bacteria isolated from fungi. One bacterial strain (Streptomyces sp. CLI2509) from the bracket fungus Hymenochaete rubiginosa, produced an unusual peptide, tryptorubin A, which contains heteroaromatic links between side chains that give it a rigid polycyclic globular structure. The three-dimensional structure was determined by NMR and MS, including a 13C-13C COSY of isotopically enriched material, degradation, derivatives, and computer modeling. Whole genome sequencing identified a likely pair of biosynthetic genes responsible for tryptorubin A’s linear hexapeptide backbone. The genome also revealed the close relationship between CLI2509 and Streptomyces sp. SPB78, which was previously implicated in an insect–bacterium symbiosis