Necrotizing enterocolitis (NEC) is an inflammatory bowel necrosis of premature infants. In tissue samples of NEC, we identified numerous macrophages and a few neutrophils but not many lymphocytes. We hypothesized that these pathoanatomic characteristics of NEC represent a common tissue injury response of the gastrointestinal tract to a variety of insults at a specific stage of gut development. To evaluate developmental changes in mucosal inflammatory response, we used trinitrobenzene sulfonic acid (TNBS)-induced inflammation as a nonspecific insult and compared mucosal injury in newborn vs. adult mice. Enterocolitis was induced in 10-day-old pups and adult mice (n = 25 animals per group) by administering TNBS by gavage and enema. Leukocyte populations were enumerated in human NEC and in murine TNBS-enterocolitis using quantitative immunofluorescence. Chemokine expression was measured using quantitative polymerase chain reaction, immunoblots, and immunohistochemistry. Macrophage recruitment was investigated ex vivo using intestinal tissue-conditioned media and bone marrow-derived macrophages in a microchemotaxis assay. Similar to human NEC, TNBS enterocolitis in pups was marked by a macrophage-rich leukocyte infiltrate in affected tissue. In contrast, TNBS-enterocolitis in adult mice was associated with pleomorphic leukocyte infiltrates. Macrophage precursors were recruited to murine neonatal gastrointestinal tract by the chemokine CXCL5, a known chemoattractant for myeloid cells. We also demonstrated increased expression of CXCL5 in surgically resected tissue samples of human NEC, indicating that a similar pathway was active in NEC. We concluded that gut mucosal injury in the murine neonate is marked by a macrophage-rich leukocyte infiltrate, which contrasts with the pleomorphic leukocyte infiltrates in adult mice. In murine neonatal enterocolitis, macrophages were recruited to the inflamed gut mucosa by the chemokine CXCL5, indicating that CXCL5 and its cognate receptor CXCR2 merit further investigation as potential therapeutic targets in NEC.

Plate motion, crustal deformation, and earthquake occurrence processes in the northwest Sunda Arc, which includes the Indo-Burmese wedge (IBW) in the forearc and the Sagaing fault in the backarc, are very poorly constrained. Plate reconstruction models and geological structures in the region suggest that subduction in the IBW occurred in the geological past, but whether it is still active and how the plate motion between the India and Sunda plates is partitioned between motion in the IBW and Sagaing fault is largely unknown. Recent GPS measurements of crustal deformation and available long-term rates of motion across the Sagaing fault suggest that ~20 ± 3 mm/yr of the relative plate motion of ~36 mm/yr between the India and Sunda plates is accommodated at the Sagaing fault through dextral strike-slip motion. We report results from a dense GPS network in the IBW that has operated since 2004. Our analysis of these measurements and the seismicity of the IBW suggest that the steeply dipping Churachandpur-Mao fault in the IBW accommodates the remaining motion of ~18 ± 2 mm/yr between the India and Sunda plates through dextral strike-slip motion, and this motion occurs predominantly through velocity strengthening frictional behavior, i.e., aseismic slip. The aseismic motion on this plate boundary fault signifi cantly lowers the seismic hazard due to major and great interplate earthquakes along this plate boundary.

Although the overall infection rate after ACL reconstruction is relatively low, the significantly higher rate of infections with hamstring autografts compared with BPTB autografts should be a consideration when discussing graft choices for ACL reconstruction.

Purpose The purpose of this study was to evaluate the efficacy of hook of the hamate excision for fracture in a large cohort of patients to better understand recovery time and complications. Methods We retrospectively reviewed the medical records of patients treated with surgical excision for hook of the hamate fractures at 2 different centers. We collected information on demographics, clinical presentation, and postoperative complications. Continuous outcome variables included time-to-surgery, return-to-play and return to activity. Results Our cohort of 81 patients had a median age of 22 years and was composed of 74 athletes including 57 baseball players, and 8 golfers. The median time to return to play was 6 weeks (range 1 – 36 weeks) after surgery; 11 patients (14%) had a return at 12 weeks or longer. Seventy-eight patients returned to pre-injury activity levels. Twelve patients with a full-recovery continued to experience some level of intermittent, non-specific pain in the affected hand, although this was not severe enough to require additional treatment. We observed a 25% incidence of postoperative complications with the majority consisting of transient ulnar nerve dysfunction. Complications were more common among non-athletes, those presenting with nonunions, and those experiencing longer intervals between injury and surgery. Conclusion In most cases, surgical excision as treatment for hook of the hamate fractures is safe and allows a relatively rapid return to play. However, we found a higher incidence of complications, including transient ulnar nerve dysfunction, than has been previously reported. Additionally, there is a group of patients with delayed return to play and continued discomfort after surgery. These findings should inform the discussion with surgical candidates.