Treatment Outcomes in Gram Negative Periprosthetic Joint Infection

Introduction: Outcomes associated with periprosthetic joint infection (PJI) involving Gram negative (GN) organisms are poorly understood. While prevailing beliefs indicate that GN PJI cases have poorer prognoses than Gram positive (GP) cases, the current literature is sparse and inconsistent. Objective: The purpose of this study is to systematically compare the treatment outcomes for GN PJI versus GP PJI. Methods: A retrospective review of 1189 PJI cases between 2007 and 2017 was performed using an institutional PJI database. Treatment failure defined by the Delphi criteria was compared between cases with only GN organisms (n=45) and only GP organisms (n=663). Cox multivariate regression was used to predict time to failure. Results: GN status did not have significantly higher rates of treatment failure compared to GP PJI (OR=1.021, p=.375) in the multivariate analysis. After sub-analysis of only two-stage exchange procedures, GN cases were significantly less likely to reach reimplantation than GP cases (OR=.182, p\u3c.0001). Patients with GN infections were older (p=.041) and had more comorbidities (p\u3c.0001) than GP patients. Conclusions: While there was no observed difference in the overall Delphi failure rates between GN and GP PJI cases, GN patients were significantly less likely to reach reimplantation. We hypothesize this is largely a result of the GN patients being older and more comorbid hosts. This data increases insight into the risk factors and outcomes of GN PJI. Further research is needed to investigate the utility of alternate procedures to the two-stage exchange in older or immunocompromised patients

A retinal code for motion along the gravitational and body axes

Self-motion triggers complementary visual and vestibular reflexes supporting image-stabilization and balance. Translation through space produces one global pattern of retinal image motion (optic flow), rotation another. We examined the direction preferences of direction-sensitive ganglion cells (DSGCs) in flattened mouse retinas in vitro. Here we show that for each subtype of DSGC, direction preference varies topographically so as to align with specific translatory optic flow fields, creating a neural ensemble tuned for a specific direction of motion through space. Four cardinal translatory directions are represented, aligned with two axes of high adaptive relevance: the body and gravitational axes. One subtype maximizes its output when the mouse advances, others when it retreats, rises or falls. Two classes of DSGCs, namely, ON-DSGCs and ON-OFF-DSGCs, share the same spatial geometry but weight the four channels differently. Each subtype ensemble is also tuned for rotation. The relative activation of DSGC channels uniquely encodes every translation and rotation. Although retinal and vestibular systems both encode translatory and rotatory self-motion, their coordinate systems differ

Identifying and prioritizing strategies for comprehensive liver cancer control in Asia

<p>Abstract</p> <p>Background</p> <p>Liver cancer is both common and burdensome in Asia. Effective liver cancer control, however, is hindered by a complex etiology and a lack of coordination across clinical disciplines. We sought to identify strategies for inclusion in a comprehensive liver cancer control for Asia and to compare qualitative and quantitative methods for prioritization.</p> <p>Methods</p> <p>Qualitative interviews (N = 20) with international liver cancer experts were used to identify strategies using Interpretative Phenomenological Analysis and to formulate an initial prioritization through frequency analysis. Conjoint analysis, a quantitative stated-preference method, was then applied among Asian liver cancer experts (N = 20) who completed 12 choice tasks that divided these strategies into two mutually exclusive and exhaustive subsets. Respondents' preferred plan was the primary outcome in a choice model, estimated using ordinary least squares (OLS) and logistic regression. Priorities were then compared using Spearman's Rho.</p> <p>Results</p> <p>Eleven strategies were identified: <it>Access to treatments; Centers of excellence; Clinical education; Measuring social burden; Monitoring of at-risk populations; Multidisciplinary management; National guidelines; Public awareness; Research infrastructure; Risk-assessment and referral</it>; and <it>Transplantation infrastructure</it>. Qualitative frequency analysis indicated that <it>Risk-assessment and referral </it>(85%), <it>National guidelines </it>(80%) and <it>Monitoring of at-risk populations </it>(80%) received the highest priority, while conjoint analysis pointed to <it>Monitoring of at-risk populations </it>(p < 0.001), <it>Centers of excellence </it>(p = 0.002), and <it>Access to treatments </it>(p = 0.004) as priorities, while <it>Risk-assessment and referral </it>was the lowest priority (p = 0.645). We find moderate concordance between the qualitative and quantitative methods (rho = 0.20), albeit insignificant (p = 0.554), and a strong concordance between the OLS and logistic regressions (rho = 0.979; p < 0.0001).</p> <p>Conclusions</p> <p>Identified strategies can be conceptualized as the ABCs of comprehensive liver cancer control as they focus on <it>Antecedents</it>, <it>Better care </it>and <it>Connections </it>within a national strategy. Some concordance was found between the qualitative and quantitative methods (e.g. <it>Monitoring of at-risk populations</it>), but substantial differences were also identified (e.g. qualitative methods gave highest priority to risk-assessment and referral, but it was the lowest for the quantitative methods), which may be attributed to differences between the methods and study populations, and potential framing effects in choice tasks. Continued research will provide more generalizable estimates of priorities and account for variation across stakeholders and countries.</p

The Emergence of Emotions

Emotion is conscious experience. It is the affective aspect of consciousness. Emotion arises from sensory stimulation and is typically accompanied by physiological and behavioral changes in the body. Hence an emotion is a complex reaction pattern consisting of three components: a physiological component, a behavioral component, and an experiential (conscious) component. The reactions making up an emotion determine what the emotion will be recognized as. Three processes are involved in generating an emotion: (1) identification of the emotional significance of a sensory stimulus, (2) production of an affective state (emotion), and (3) regulation of the affective state. Two opposing systems in the brain (the reward and punishment systems) establish an affective value or valence (stimulus-reinforcement association) for sensory stimulation. This is process (1), the first step in the generation of an emotion. Development of stimulus-reinforcement associations (affective valence) serves as the basis for emotion expression (process 2), conditioned emotion learning acquisition and expression, memory consolidation, reinforcement-expectations, decision-making, coping responses, and social behavior. The amygdala is critical for the representation of stimulus-reinforcement associations (both reward and punishment-based) for these functions. Three distinct and separate architectural and functional areas of the prefrontal cortex (dorsolateral prefrontal cortex, orbitofrontal cortex, anterior cingulate cortex) are involved in the regulation of emotion (process 3). The regulation of emotion by the prefrontal cortex consists of a positive feedback interaction between the prefrontal cortex and the inferior parietal cortex resulting in the nonlinear emergence of emotion. This positive feedback and nonlinear emergence represents a type of working memory (focal attention) by which perception is reorganized and rerepresented, becoming explicit, functional, and conscious. The explicit emotion states arising may be involved in the production of voluntary new or novel intentional (adaptive) behavior, especially social behavior

Patient reported disability of ankle, hindfoot, midfoot and hallux metatarsophalangeal arthritis

Category: Ankle, Ankle Arthritis, Hindfoot, Midfoot/Forefoot Introduction/Purpose: There has been in increased interest in foot and ankle arthritis in the literature in recent years. A significant focus of the literature has been which operative techniques are best for managing these problems. Some work has been done analogizing disability due to ankle arthritis to more familiar joints such as the hip. There is little data explaining how much patient reported disability is associated with each type of isolated foot and ankle arthritis. Various clinical rating scales have proven how debilitating foot and ankle arthritides can be to patients. The purpose of our study was to use Functional Foot Index (FFI) and Short Form-12 (SF-12) rating scales to compare the patient reported disability associated with ankle, hindfoot, midfoot, and hallux metatarsalphalangeal (MTP) arthritides. Methods: We retrospectively reviewed the FFI and SF-12 (both Physical Component Scores (PCS) and Mental Component Scores (MCS)) of patients who presented to a high volume orthopaedic foot and ankle practice between 2010 and 2016 with either ankle, hindfoot, midfoot or hallux MTP arthritis. We included patients between 18-65 years of age who underwent a surgical procedure for arthritis within 6 months of their initial presentation. We excluded patients with any medical or surgical co-morbidities known to affect disability scores. A total of 214 FFI and 195 SF-12 data sets were included. Results: Study population SF-12 PCS scores for all patients with ankle or foot arthritis were significantly lower than US age-based norms. Patients with ankle arthritis had the highest disability (FFI score 46.5, SF-12 PCS 32.3). Patients with midfoot and hindfoot arthritis had intermediate disability (Midfoot FFI score 34.9, SF-12 PCS 34.5; Hindfoot FFI score 44.3, SF-12 PCS 34.5). Patients with hallux MTP arthritis had the lowest disability (FFI score 32.9, SF-12 PCS 40.7). All FFI and SF-12 PCS scores were statistically significant. SF 12 MCS were not statistically significant. Conclusion: All patients with foot and ankle arthritis had increased disability compared to US age-based norms. Patients with ankle arthritis experience the most self-reported disability and patients with hallux MTP arthritis experience the least self- reported disability of the isolated types of arthritis in orthopaedic foot and ankle

SBRT to adrenal metastases provides high local control with minimal toxicity

Purpose: The adrenal glands are a common site of metastases because of their rich blood supply. Previously, adrenal metastases were treated with systemic chemotherapy or, more rarely, with surgical resection or palliative radiation therapy. Stereotactic body radiation therapy (SBRT) has recently emerged as an attractive noninvasive approach to definitively treat these lesions. We present our experience in treating adrenal metastases using SBRT and review the current literature. Methods and materials: This is a single-institution retrospective review of patients who received SBRT to adrenal metastases originating from various primary malignancies. Patients who were eligible for SBRT included those with limited metastatic disease (≤5 sites) with otherwise controlled metastatic disease and uncontrolled adrenal metastases. Results: Ten patients met the study's inclusion criteria and received SBRT doses of 30 to 48 Gy in 3 to 5 fractions. Acute sequelae of SBRT treatment included 4 patients with grades 1 or 2 nausea, 3 patients with grade 1 fatigue, and 1 with grade 1 diarrhea. The median follow-up was 6 months with a median overall survival of 9.9 months. One patient demonstrated progressive adrenal gland disease 18.8 months after SBRT treatment. Seven patients developed new distant metastases after treatment, with a median progression-free survival of 3.4 months. Three months after SBRT to the adrenal gland, 1 patient developed a gastrointestinal bleed. Conclusions: These results complement the limited existing body of literature by demonstrating that SBRT provides good control of treated adrenal gland metastasis; however, high-grade late toxicities may occur. More stringent dose constraint limits may prevent associated serious adverse events