Precise editing of genomic DNA can be achieved upon repair of CRISPR-induced DNA double-stranded breaks (DSBs) by homology-directed repair (HDR). However, the efficiency of this process is limited by DSB repair pathways competing with HDR, such as non-homologous end joining (NHEJ). Here we individually express in human cells 204 open reading frames involved in the DNA damage response (DDR) and determine their impact on CRISPR-mediated HDR. From these studies, we identify RAD18 as a stimulator of CRISPR-mediated HDR. By defining the RAD18 domains required to promote HDR, we derive an enhanced RAD18 variant (e18) that stimulates CRISPR-mediated HDR in multiple human cell types, including embryonic stem cells. Mechanistically, e18 induces HDR by suppressing the localization of the NHEJ-promoting factor 53BP1 to DSBs. Altogether, this study identifies e18 as an enhancer of CRISPR-mediated HDR and highlights the promise of engineering DDR factors to augment the efficiency of precision genome editing.

In 32 consecutive intra-articular calcaneal fractures (28 patients, 4 bilateral), open treatment was done using the modified Palmer lateral approach and the reduction was assessed with postoperative radiography and computed tomography (CT) (coronal and axial images, 1-2 days after surgery). Retrospective analysis of the available radiographs and CT scans was done in 27 fractures (25 patients, 2 bilateral) to assess accuracy of reduction achieved; in five fractures the studies were not available. Sanders classification was type I in 2 (7%), type II in 20 (74%), and type III in 5 (19%) fractures; the calcaneocuboid joint was involved in 9 (33%) fractures. Reduction included elevation of the depressed lateral side of the posterior facet, reduction of the neck (anterior third of calcaneus) to the body (middle third of calcaneus), realignment of the posterior tuberosity, and reduction of lateral wall blowout; internal fixation was done with cannulated screws. Mean (+/-SD) values of the following displacement parameters were significantly improved after surgery: Böhler's angle, posterior facet angle, lateral posterior facet articular depression, heel width (coronal CT), and calcaneal height. There was no significant difference between preoperative and postoperative values of mean angle of Gissane, posterior tuberosity position, and body width and length on axial CT. One (3%) of the 32 fractures was associated with preoperative (traumatic) full-thickness skin necrosis at the sinus tarsi that required free muscle flap coverage. One (3%) postoperative wound healing complication occurred, consisting of wound dehiscence and drainage at the central portion of the surgical wound in a smoker, which resolved with dressing changes and antibiotics. In conclusion, the modified Palmer lateral approach enabled open reduction of major features of calcaneal fractures with less soft-tissue risk than more extensile approaches.

Introduction:The morphometry of distal end radius (DER) comprises the four necessary parameters: radial inclination, palmer tilt, radial height, and ulnar variance. The unblemished intellect about the morphometry is urged for the management of fracture of DER. The goal of our study was to determine the values of morphometric parameters of the DER from the adult Indian.Materials and Methods:It was a single hospital- based observational cross-sectional, prospective study. Radial inclination, radial height, and ulnar variance were measured on posteroanterior view, and the measurement of palmer tilt was accomplished on the lateral view. All the statistical analysis was done by Microsoft XL 2007 (data add in function were installed for data analysis). T-test was used for comparing the means of the parameters.Results:Two hundred and forty two (n = 242) X-rays were included in this study to analyze. The mean value (n = 242) of radial inclination was 23.27°± (standard deviation [SD]) 7.42° (range: 11.3–42.1°), palmer tilt 10.07° ± (SD) 5.28° (range: 1–16.9°), radial height 11.31 mm ± (SD) 4.9 mm (range: 7.1–30.4 mm), and ulnar variance 0.66 mm ± (SD) 2.46 mm (range: −2.4 to +4.1).Conclusion:This study may provide an inauguratory plinth to prosecute the further analytical research in the Indian population. Moreover, the data may also be used as a reference data for the anatomical alignment while treating the injuries of the DER in the Indian population.

Prosthetic joint infection (PJI) occurs with significant morbidity and health care expenditure. Transplant recipients on immunosuppressive medications are at increased risk for infections caused by less common organisms at unusual sites. Here we report a case of isolated PJI with Mycobacterium avium complex (MAC) in an immunosuppressed failed kidney transplant recipient and review the literature on this unique infection. We discuss the likely pathogenesis of PJI with MAC including the role of biofilm formation by non-tuberculous mycobacteria. The possible role of cytokine milieu alteration by immunosuppressive therapy, particularly the reduction in interferon-gamma levels, as a predisposing factor for non-tuberculous mycobacterial infections in transplant recipients is explored. Lastly, we review the role of immune cell function assay in predicting the susceptibility to infection in our patient specifically and in solid organ transplant recipients in general.

In many heart diseases, exercise treadmill testing(ETT) has useful functional correlates and/or prognostic value. However, its predictive value in mitral regurgitation(MR) is undefined. To determine whether ETT descriptors predict death or indications for mitral valve surgery among patients with MR, we prospectively followed, for 7±3 endpoint-free years, a cohort of 38 patients with chronic severe nonischemic MR who underwent modified Bruce ETT; all lacked surgical indications at study entry. Their baseline exercise descriptors also were compared with those from 46 patients with severe MR who, at entry, already had reached surgical indications. Endpoints during follow-up among the cohort included sudden death(n=1), heart failure symptoms(n=2), atrial fibrillation(n=4), LVEF<60%(n=2), LV systolic dimensions(IDs)≥45 mm(n=12) and LVIDs>40mm(n=11), LVEF<60%+LVIDs 45 mm(n=3), and heart failure+LVIDs 45mm +LVEF<60%(n=1). In univariate analysis, exercise duration(p=.004), chronotropic response(p=. 007), percent predicted peak heart rate(p=.01) and heart rate recovery(p<.02) predicted events; in multivariate analysis, only exercise duration was predictive(p<.02). Average annual event risk was 5-fold lower(4.62%) with exercise duration≥15 minutes vs. <15 minutes(average annual risk=23.48%, p=.004). Relative risks among patients with and without exercise-inducible ST segment depression were comparable(≤1.3 [NS]) whether defined at entry and/or during follow-up. Exercise duration, but not prevalence of exercise-inducible ST segment depression, was lower(p<. 001) among patients with surgical indications at entry vs. initially endpoint-free patients. In conclusion, among asymptomatic patients with chronic severe nonischemic MR and no objective criteria for operation, progression to surgical indications generally is rapid. However, those with excellent exercise tolerance have a relatively benign course. Exercise-inducible ST segment depression has no prognostic value in this population.We followed, for 7±3 endpoint-free years, 38 patients with chronic severe nonischemic mitral regurgitation (MR) who underwent modified Bruce exercise treadmill testing (ETT) to determine whether ETT descriptors predict death or indications for mitral valve surgery. At study entry, all lacked surgical indications. Exercise duration independently predicted subsequent events; event risks among patients with and without exercise-inducible ST segment depression were comparable. We conclude that among asymptomatic patients with chronic severe nonischemic MR Address for Correspondence: Jeffrey S. Borer, M.D., New York-Presbyterian Hospital New York Weill Cornell Center, 525 East 68 th Street, New York, N.Y. 10021, 212-746-4646=phone, 212-746-8448=fax, canadaD45@aol.com=email Publisher's Disclaimer: This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulti...