Update in laparoscopic approach to acute mesenteric ischemia

AMI is an uncommon but serious disease often associated with a bad prognosis, associated with occlusion of Superior Mesenteric Artery (SMA) for embolism or thrombosis (67.2%), mesenteric venous thrombosis (15.7%), and non-occlusive mesenteric ischemia (15.4%). Clinical markers are often aspecific and symptoms low suggestive. The gold standard for the diagnosis is multidetector CT Angiography (CTA) with sensibility of 93.3% and specificity of 95.9%. Abdominal exploration could be useful to confirm cases of AMI without signs of SMA occlusion at CTA. Few reports have been found on the diagnostic role of Exploratory Laparoscopy. To increase the sensibility of laparoscopy in the diagnosis of AMI in the last ten years, some studies had shown the possibility of using fluorescein to underline the bowel areas of interest by ischemia. The best of laparoscopy in AMI diagnosis remains the second look and bedside use (directly in ICU when possible) overall in patients with Aortic dissection type B (preferable chronic type). In a limited number of cases, it is possible to evaluate bowel perfusion laparoscopically and at the same time perform a laparoscopical bowel resection of residual ischemic segments. However, laparoscopic primary access overall in AoD is an important tool for leading therapeutic decision and timing. Finally, laparoscopy may be a feasible alternative to CTA in patients with kidney failure that contraindicates injection of iodate CT contrast medium

openWAR: An Open Source System for Evaluating Overall Player Performance in Major League Baseball

Within baseball analytics, there is substantial interest in comprehensive statistics intended to capture overall player performance. One such measure is Wins Above Replacement (WAR), which aggregates the contributions of a player in each facet of the game: hitting, pitching, baserunning, and fielding. However, current versions of WAR depend upon proprietary data, ad hoc methodology, and opaque calculations. We propose a competitive aggregate measure, openWAR, that is based upon public data and methodology with greater rigor and transparency. We discuss a principled standard for the nebulous concept of a "replacement" player. Finally, we use simulation-based techniques to provide interval estimates for our openWAR measure.Comment: 27 pages including supplemen

Prosthetic graft infections involving the femoral artery

BackgroundProsthetic graft infection is a major complication of peripheral vascular surgery. We investigated the experience of a single institution over 10 years with bypass grafts involving the femoral artery to determine the incidence and risk factors for prosthetic graft infection.MethodsA retrospective cohort single-institution review of prosthetic bypass grafts involving the femoral artery from 2001 to 2010 evaluated patient demographics, body mass index, comorbidities, indications, location of bypass, type of prosthetic material, case urgency, and previous ipsilateral bypass or percutaneous interventions and evaluated the incidence of graft infections, amputations, and mortality.ResultsThere were 496 prosthetic grafts identified with a graft infection rate of 3.8% (n = 19) at a mean follow-up of 27 months. Multivariable analysis showed that redo bypass (hazard ratio [HR], 5.8; 95% confidence interval [CI], 2.2-15.0), active infection at the time of bypass (HR, 5.2; 95% CI, 1.9-14.2), female gender (HR, 4.5; 95% CI, 1.6-12.7), and diabetes mellitus (HR, 4.6; 95% CI, 1.5-14.3) were significant predictors of graft infection. Graft infection was predictive of major lower extremity amputation (HR, 9.8; 95% CI, 3.5-27.1), as was preoperative tissue loss (HR, 4.7; 95% CI, 1.8-11.9). Graft infection did not predict long-term mortality; however, chronic renal insufficiency (HR, 2.3; 95% CI, 1.6-3.4), tissue loss (HR, 1.4; 95% CI, 1.0-1.9), and active infection (HR, 2.3; 95% CI, 1.6-3.4) did. Infected grafts were removed 79% of the time. Staphylococcus epidermidis (37%) and methicillin-sensitive Staphylococcus aureus (26%) were the most common pathogens isolated.ConclusionsRedo bypass, female gender, diabetes, and active infection at the time of bypass are associated with a higher risk for prosthetic graft infection and major extremity amputation but do not confer an increased risk of mortality. Autologous vein for lower extremity bypass and endovascular interventions should be considered when feasible in high-risk patient

BMD-based assessment of local porosity in human femoral cortical bone

Cortical pores are determinants of the elastic properties and of the ultimate strength of bone tissue. An increase of the overall cortical porosity (Ct.Po) as well as the local coalescence of large pores cause an impairment of the mechanical competence of bone Therefore, Ct Po represents a relevant target for identifying patients with high fracture risk. However, given their small size, the in vivo imaging of cortical pores remains challenging. The advent of modern high-resolution peripheral quantitative computed tomography (HR-pQCT) triggered new methods for the clinical assessment of Ct Po at the peripheral skeleton, either by pore segmentation or by exploiting local bone mineral density (BMD) In this work, we compared BMD-based Ct.Po estimates with highresolution reference values measured by scanning acoustic microscopy. A calibration rule to estimate local Ct.Po from BMD as assessed by HR-pQCT was derived experimentally. Within areas of interest smaller than 0.5 mm(2), our model was able to estimate the local Ct.Po with an error of 3.4%. The incorporation of the BMD mhomogeneity and of one parameter from the BMD distribution of the entire scan volume led to a relative reduction of the estimate error of 30%, if compared to an estimate based on the average BMD. When applied to the assessment of Ct.Po within entire cortical bone cross-sections, the proposed BMD-based method had better accuracy than measurements performed with a conventional threshold-based approach.</p

Correction: Large cortical bone pores in the tibia are associated with proximal femur strength

[This corrects the article DOI: 10.1371/journal.pone.0215405.

The Feasibility of High-Resolution Peripheral Quantitative Computed Tomography (HR-pQCT) in Patients with Suspected Scaphoid Fractures

Introduction: Diagnosing scaphoid fractures remains challenging. High-resolution peripheral quantitative computed tomography (HR-pQCT) might be a potential imaging technique, but no data are available on its feasibility to scan the scaphoid bone in vivo. Methodology: Patients (≥18 years) with a clinically suspected scaphoid fracture received an HR-pQCT scan of the scaphoid bone (three 10.2-mm stacks, 61-μm voxel size) with their wrist immobilized with a cast. Scan quality assessment and bone contouring were performed using methods originally developed for HR-pQCT scans of radius and tibia. The contouring algorithm was applied on coarse hand-drawn pre-contours of the scaphoid bone, and the resulting contours (AUTO) were manually corrected (sAUTO) when visually deviating from bone margins. Standard morphologic analyses were performed on the AUTO- and sAUTO-contoured bones. Results: Ninety-one patients were scanned. Two out of the first five scans were repeated due to poor scan quality (40%) based on standard quality assessment during scanning, which decreased to three out of the next 86 scans (3.5%) when using an additional thumb cast. Nevertheless, after excluding one scan with an incompletely scanned scaphoid bone, post hoc grading revealed a poor quality in 14.9% of the stacks and 32.9% of the scans in the remaining 85 patients. After excluding two scans with contouring problems due to scan quality, bone indices obtained by AUTO- and sAUTO-contouring were compared in 83 scans. All AUTO-contours were manually corrected, resulting in significant but small differences in densitometric and trabecular indices (<1.0%). Conclusions: In vivo HR-pQCT scanning of the scaphoid bone is feasible in patients with a clinically suspected scaphoid fracture when using a cast with thumb part. The proportion of poor-quality stacks is similar to radius scans, and AUTO-contouring appears appropriate in good- and poor-quality scans. Thus, HR-pQCT may be promising for diagnosis of and microarchitectural evaluations in suspected scaphoid fractures

Experimental tests of a seasonally changing visual preference for habitat in a long-distance migratory shorebird

Migratory shorebirds show highly organized seasonal cycles in physiological and morphological traits (body mass and composition, plumage, hormone levels, etc.), which in captivity is accompanied by restless behaviour at times when free-living birds would start migration. We introduce the idea that seasonally changing preference for habitat could motivate migrants to embark on migration and that this cognitive process could also guide them to seasonally appropriate places. We explored this by testing whether red knots (Calidris canutus), which also in captivity maintain marked circannual phenotypic rhythms, show evidence of seasonal change in preference for pictures of seasonally appropriate habitats. We first developed a method to verify whether red knots are able to memorize and discriminate contrasting pictures projected by LCD projectors. This was followed by two different experiments in which we tested for a seasonally changing preference for breeding or non-breeding habitat. When carried out during the pre-breeding season, the red knots are expected to prefer pictures of mudflats, their non-breeding habitat. At the start of the breeding season, they should prefer pictures of the tundra breeding habitat. We established that knots are able to distinguish and memorize projected images. We failed to demonstrate the predicted change in vision-based habitat preference, but for reasons of test design we do not interpret this as a strong rejection of the hypothesis. Instead, we suggest that experiments with greater numbers of individuals tested once, perhaps in combination with the provision of additional cues such as smells and sounds, will help the development of these ideas further