Measuring Apparent Trabecular Structure With pQCT: A Comparison With HR-pQCT

We evaluated how comparable peripheral quantitative computed tomography (pQCT) measurements of cortical thickness, density, and apparent trabecular structure at the ultradistal tibia were with those measured with high-resolution pQCT (HR-pQCT). We also examined whether the accuracy of the pQCT-based trabecular and cortical measurements improved with reductions in slice thickness from the standard 2.2 mm to 1.1 and 0.6 mm. We immersed 15 dry tibia specimens in saline in a sealed cylinder and scanned 22.5 mm from the distal tibia plateau using pQCT and HR-pQCT. pQCT underestimated cortical thickness by Stratec (CTh_Stratec) and trabecular spacing (Tb.Sp) by 21.4% and 72.9%, whereas bone volume to total volume (BV/TV) and cortical density (CDen) were overestimated by 265.8% and 13.1%, respectively. Measurements of trabecular volumetric bone mineral density, trabecular area, total area, cortical thickness by custom software were comparable, but for CTh_Stratec, Tb.Sp, BV/TV, and CDen, the differences between imaging devices varied with magnitude of the estimate. We recommend that researchers or clinicians interested in using pQCT to measure apparent trabecular structure or cortical thickness at the epiphyses, or in comparing findings from different devices, be aware of the differences between HR-pQCT and pQCT.     

Systemic Nickel Allergy after Internal Fixation of a Bunionectomy

Allergic reactions to implanted metals have been estimated to occur in 1% to 5% of orthopedic cases. Stainless steel screws, which contain 14% nickel, are commonly used for internal fixation in an array of podiatric procedures. We present a rare case of a systemic allergic reaction to nickel secondary to stainless steel screw fixation in a bunionectomy procedure.     

Traitements de rattrapage après irradiation prostatique : place de l’urologue

The management of recurrent prostate cancer after radiotherapy or brachytherapy is non-standardized and rapidly evolving. Local recurrence is observed on average in 30% of cases several years following irradiation. A key challenge is to determine the site of recurrence and imaging (MRI and PET choline) coupled to prostate biopsies are important to confirm the local character. Salvage therapy performed by the urologist can then control the situation. Radical prostatectomy subject to strict technical conditions is one of the most efficient local treatments, however it comes at the cost of significant urinary morbidity; minimally invasive therapies (focused ultrasound and cryotherapy) have also their place in specific indications. Each clinical situation should be discussed in pluridisciplinary meetings integrating the oncologic and functional status at recurrence, the risk/benefit ratio of each treatment, the patient's wishes and probability of survival.     

The genetic structure of native Americans in North America based on the Globalfiler® STRs

Current forensic STR databases, such as CODIS, lack population genetic data on Native American populations. Information from a geographically diverse array of tribes is necessary to provide improved statistical estimates of the strength of associations with DNA evidence. The Globalfiler® STR markers were used to characterize the genetic structure of ten tribal populations from seven geographic regions in North America, including those not presently represented in forensic databases. Samples from the Arctic region, Baja California, California/Great Basin, the Southeast, Mexico, the Midwest, and the Southwest were analyzed for allele frequencies, observed and expected heterozygosities, and F-statistics. The tribal samples exhibited an F_ST or θ value above the conservative 0.03 estimate recommended by the National Research Council (NRC) for calculating random match probabilities among Native Americans. The greater differentiation among tribal populations computed here (θ = 0.04) warrants the inclusion of additional regional Native American samples into STR databases.     

Public transit generates new physical activity: Evidence from individual GPS and accelerometer data before and after light rail construction in a neighborhood of Salt Lake City,Utah, USA

Poor health outcomes from insufficient physical activity (PA) are a persistent public health issue. Public transit is often promoted for positive influence on PA. Although there is cross-sectional evidence that transit users have higher PA levels, this may be coincidental or shifted from activities such as recreational walking. We use a quasi-experimental design to test if light rail transit (LRT) generated new PA in a neighborhood of Salt Lake City, Utah, USA. Participants (n=536) wore Global Positioning System (GPS) receivers and accelerometers before (2012) and after (2013) LRT construction. We test within-person differences in individuals’ PA time based on changes in transit usage pre- versus post-intervention. We map transit-related PA to detect spatial clustering of PA around the new transit stops. We analyze within-person differences in PA time based on daily transit use and estimate the effect of daily transit use on PA time controlling for socio-demographic variables. Results suggest that transit use directly generates new PA that is not shifted from other PA. This supports the public health benefits from new high quality public transit such as LRT.     

Average treatment effect of facility hepatopancreatobiliary cancer volume on survival of non-resected pancreatic adenocarcinoma

BackgroundTo examine the average treatment effect of hepato-pancreato-biliary (HPB) cancer volume on survival outcomes of patients with non-resected pancreatic adenocarcinoma (PDAC).MethodsWe queried the National Cancer Database (2004–2018) for patients with HPB malignancies (PDAC, pancreatic neuroendocrine neoplasms, hepatocellular carcinoma, biliary tract cancers). We determined the 25th, 50th, and 75th percentiles based on the total annual HPB volume. We then identified patients with non-resected PDAC. We utilized inverse probability (IP)-weighted Cox regression to estimate the effect of facility volume on overall survival (OS).ResultsWe identified 710,988 patients with HPB malignancies. The 25th, 50th, and 75th percentiles of total annual HPB volume were 32, 71, and 177 cases/year, respectively. We included a total of 196,150 patients with non-resected PDAC.Patients treated at ≥25th, ≥50th, and ≥75th percentile facilities had improved median OS compared to those treated at facilities below these thresholds (5.8 vs. 4.2months, 6.5 vs. 4.5months, 7.5 vs. 4.8months, respectively; p < 0.001 for all). Treatment at facilities ≥25th, ≥50th, and ≥75th percentile resulted in lower hazards of death than treatment at lower-percentile facilities (HR: 0.87, 95% CI: 0.84–0.90; HR: 0.87, 95% CI: 0.83–0.91; HR: 0.85, 95% CI: 0.79–0.91, respectively).ConclusionOur data suggest that consolidation of care of patients with PDAC to high-volume centers may be beneficial even in the nonoperative setting.