What Are the Indications and Contraindications for Irrigation and Debridement and Retention of Prosthesis (DAIR) in Patients With Infected Total Ankle Arthroplasty (TAA)?

RECOMMENDATION

Debridement, antibiotics, and implant retention (DAIR) with polyethylene exchange may be indicated in early postoperative infection (<4 weeks) or acute hematogenous infection (<4 weeks of symptoms) in patients with infected total ankle arthroplasty (TAA), although recurrent infection has been seen. Suffcient clinical evidence is lacking.

LEVEL OF EVIDENCE

Consensus.

DELEGATE VOTE

Agree: 100%, Disagree: 0%, Abstain: 0% (Unanimous, Strongest Consensus).

Health Outcomes of Youth in Clinical Pediatric Weight Management Programs in POWER

OBJECTIVE

To describe treatment outcomes of children and adolescents enrolled in the Pediatric Obesity Weight Evaluation Registry, a consortium of multicomponent pediatric weight management programs in the US.

STUDY DESIGN

This multicenter prospective observational cohort study, established in 2013, includes youth (2-18 years of age) with obesity enrolled from 31 Pediatric Obesity Weight Evaluation Registry (POWER) sites over a 2-year period and followed up to 12 months. Weight status was evaluated by the percentage of the 95th percentile for body mass index (%BMIp95). Associations of weight status outcomes with patient characteristics and program exposure were analyzed with multivariable mixed effects modeling.

RESULTS

We included 6454 children and adolescents (median age, 11 years; IQR, 9-14 years; 53% white, 32% Hispanic; 73% with severe obesity) who were enrolled in POWER. Median changes in %BMIp95 for this cohort were -1.88 (IQR, -5.8 to 1.4), -2.50 (IQR, -7.4 to 1.8), -2.86 (IQR, -8.7 to 1.9), at 4-6, 7-9, and 10-12 of months follow-up, respectively (all P < .05). Older age (≥12 years), greater severity of obesity, and Hispanic race/ethnicity were associated with better improvement in %BMIp95. A 5-percentage point decrease in %BMIp95 was associated with improvement in cardiometabolic risk factors.

CONCLUSIONS

Overall, treatment in pediatric weight management programs is associated with a modest median decrease in BMI as measured by change in %BMIp95. Further studies are needed to confirm these findings, as well as to identify additional strategies to enhance the effectiveness of these multicomponent interventions for youth with severe obesity.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT02121132.

The approach to an isolated close anterior margin in breast conserving surgery

INTRODUCTION

Although close radial margins after breast-conserving surgery routinely undergo re-excision, appropriate management of patients with close anterior margins remains a topic of controversy. An increasing body of literature suggests that re-excision of close anterior margins yields low rates of residual malignancy and may only be necessary in selected patients. The aim of this study was to examine the management of close anterior margins after breast conserving surgery in a single institution and to analyse the rate of residual disease in re-excised anterior margins.

METHODS

All patients having breast conserving surgery at St Vincent's University Hospital from January 2008 to December 2012 were reviewed retrospectively. Data collected included patient demographics, tumour characteristics, margin positivity, re-excision rates and definitive histology of the re-excision specimens. A close margin was defined as les than 2 mm.

RESULTS

A total of 930 patients were included with an average age of 65 years (range 29-94 years). Of these, 121 (13%) had a close anterior margin. Further re-excison of the anterior margin was carried out in 37 patients (30.6%) and a further 16 (13.2%) proceeded to mastectomy. Residual disease was found in 18.5% (7/36) of those who underwent re-excision and 7/16 (43.75%) of those who underwent mastectomy. Overall, 11.57% (14/121) of patients with close anterior margins were subsequently found to have residual disease.

CONCLUSION

The low yield of residual disease in re-excised anterior margins specimens supports the concept that routine re-excision of close anterior margins is not necessary. Further research is required to definitively assess its influence on the risk of local recurrence.

Constraining the p-Mode-g-Mode Tidal Instability with GW170817

We analyze the impact of a proposed tidal instability coupling p modes and g modes within neutron stars on GW170817. This nonresonant instability transfers energy from the orbit of the binary to internal modes of the stars, accelerating the gravitational-wave driven inspiral. We model the impact of this instability on the phasing of the gravitational wave signal using three parameters per star: an overall amplitude, a saturation frequency, and a spectral index. Incorporating these additional parameters, we compute the Bayes factor (lnB_{!pg}^{pg}) comparing our p-g model to a standard one. We find that the observed signal is consistent with waveform models that neglect p-g effects, with lnB_{!pg}^{pg}=0.03_{-0.58}^{+0.70} (maximum a posteriori and 90% credible region). By injecting simulated signals that do not include p-g effects and recovering them with the p-g model, we show that there is a ≃50% probability of obtaining similar lnB_{!pg}^{pg} even when p-g effects are absent. We find that the p-g amplitude for 1.4  M_{⊙} neutron stars is constrained to less than a few tenths of the theoretical maximum, with maxima a posteriori near one-tenth this maximum and p-g saturation frequency ∼70  Hz. This suggests that there are less than a few hundred excited modes, assuming they all saturate by wave breaking. For comparison, theoretical upper bounds suggest ≲10^{3} modes saturate by wave breaking. Thus, the measured constraints only rule out extreme values of the p-g parameters. They also imply that the instability dissipates ≲10^{51}  erg over the entire inspiral, i.e., less than a few percent of the energy radiated as gravitational waves.

57 Non-targeted metabolomic profiles within the uterine milieu of porcine pregnancies containing populations of uniform or diverse spherical, ovoid, or tubular conceptuses during initiation of embryo elongation

Alterations in the signalling of critical molecular factors within the uterine milieu result in deficiencies in embryo elongation, leading directly to embryonic loss as well as delayed elongation. The objective of this study was to identify metabolites within the uterine environment from populations of uniform and diverse porcine conceptuses as they transition between spherical, ovoid, and tubular conceptuses during the initiation of embryo elongation. White crossbred gilts (n=38) were bred at standing oestrus (designated Day 0) and again 24h later and randomly assigned to collection group. At Day 9, 10, or 11 of gestation, reproductive tracts were collected immediately following harvest and flushed with 40mL of RPMI-1640 media. Conceptus morphologies were assessed from each pregnancy to assign to 1 of 5 treatment groups based on these morphologies: (1) uniform spherical (n=8); (2) diverse spherical and ovoid (n=8); (3) uniform ovoid (n=8); (4) diverse ovoid and tubular (n=8); and (5) uniform tubular (n=6). Subsequently uterine flushings from these pregnancies were submitted for non-targeted profiling by gas chromatography-mass spectrometry (GC-MS) and ultra-performance liquid chromatography-mass spectrometry (UPLC-MS) techniques. Raw spectral data were processed using the XCMS package in R (R Foundation for Statistical Computing, Vienna, Austria) and features were clustered using RAMclustR. Unsupervised multivariate principal component analysis was performed in R using pcamethods package, and univariate ANOVA was performed in R with a Benjamini-Hochberg false discovery rate adjustment. Principal component analysis of the GC-MS and UPLC-MS data identified 153 and 104 metabolites, respectively. Of the identified metabolites, 51 and 71 metabolites from the GC-MS and UPLC-MS analysis, respectively, corresponded to known compounds. After false discovery rate adjustment of the GC-MS and UPLC-MS data, 38 and 59 metabolites from the GC-MS and UPLC-MS analysis, respectively, differed (P&lt;0.05) in uterine flushings from pregnancies for the 5 conceptus stages. Some metabolites were greater (P&lt;0.05) in abundance for uterine flushings containing earlier stage conceptuses (i.e. spherical) such as uric acid, tryptophan, 5-hydroxy-L-tryptophan, and L-tryosine. In contrast, some metabolites were greater (P&lt;0.05) in abundance for uterine flushings containing later stage conceptuses (i.e. tubular) such as creatinine, serine, isovaleryl-I-carnitine, and lauric diethaolamide. These data illustrate several putative metabolites that change within the uterine milieu as porcine embryos transition between spherical, ovoid, and tubular conceptuses. Funding was provided by USDA-NIFA-AFRI Grant no. 2017-67015-26456.

Search for Subsolar-Mass Ultracompact Binaries in Advanced LIGO's First Observing Run

We present the first Advanced LIGO and Advanced Virgo search for ultracompact binary systems with component masses between 0.2  M_{⊙}-1.0  M_{⊙} using data taken between September 12, 2015 and January 19, 2016. We find no viable gravitational wave candidates. Our null result constrains the coalescence rate of monochromatic (delta function) distributions of nonspinning (0.2  M_{⊙}, 0.2  M_{⊙}) ultracompact binaries to be less than 1.0×10^{6}  Gpc^{-3}  yr^{-1} and the coalescence rate of a similar distribution of (1.0  M_{⊙}, 1.0  M_{⊙}) ultracompact binaries to be less than 1.9×10^{4}  Gpc^{-3}  yr^{-1} (at 90% confidence). Neither black holes nor neutron stars are expected to form below ∼1  M_{⊙} through conventional stellar evolution, though it has been proposed that similarly low mass black holes could be formed primordially through density fluctuations in the early Universe and contribute to the dark matter density. The interpretation of our constraints in the primordial black hole dark matter paradigm is highly model dependent; however, under a particular primordial black hole binary formation scenario we constrain monochromatic primordial black hole populations of 0.2  M_{⊙} to be less than 33% of the total dark matter density and monochromatic populations of 1.0  M_{⊙} to be less than 5% of the dark matter density. The latter strengthens the presently placed bounds from microlensing surveys of massive compact halo objects (MACHOs) provided by the MACHO and EROS Collaborations.

GW170817: Measurements of Neutron Star Radii and Equation of State

On 17 August 2017, the LIGO and Virgo observatories made the first direct detection of gravitational waves from the coalescence of a neutron star binary system. The detection of this gravitational-wave signal, GW170817, offers a novel opportunity to directly probe the properties of matter at the extreme conditions found in the interior of these stars. The initial, minimal-assumption analysis of the LIGO and Virgo data placed constraints on the tidal effects of the coalescing bodies, which were then translated to constraints on neutron star radii. Here, we expand upon previous analyses by working under the hypothesis that both bodies were neutron stars that are described by the same equation of state and have spins within the range observed in Galactic binary neutron stars. Our analysis employs two methods: the use of equation-of-state-insensitive relations between various macroscopic properties of the neutron stars and the use of an efficient parametrization of the defining function p(ρ) of the equation of state itself. From the LIGO and Virgo data alone and the first method, we measure the two neutron star radii as R_{1}=10.8_{-1.7}^{+2.0}  km for the heavier star and R_{2}=10.7_{-1.5}^{+2.1}  km for the lighter star at the 90% credible level. If we additionally require that the equation of state supports neutron stars with masses larger than 1.97  M_{⊙} as required from electromagnetic observations and employ the equation-of-state parametrization, we further constrain R_{1}=11.9_{-1.4}^{+1.4}  km and R_{2}=11.9_{-1.4}^{+1.4}  km at the 90% credible level. Finally, we obtain constraints on p(ρ) at supranuclear densities, with pressure at twice nuclear saturation density measured at 3.5_{-1.7}^{+2.7}×10^{34}  dyn cm^{-2} at the 90% level.

Decreased activation and subsyndromal manic symptoms predict lower remission rates in bipolar depression

OBJECTIVE

Activation encompasses energy and activity and is a central feature of bipolar disorder. However, the impact of activation on treatment response of bipolar depression requires further exploration. The aims of this study were to assess the association of decreased activation and sustained remission in bipolar depression and test for factors that could affect this association.

METHODS

We assessed participants with Diagnostic and Statistical Manual of Mental Disorders (4th ed) bipolar depression ( n = 303) included in a comparative effectiveness study of lithium- and quetiapine-based treatments (the Bipolar CHOICE study). Activation was evaluated using items from the Bipolar Inventory of Symptoms Scale. The selection of these items was based on a dimension of energy and interest symptoms associated with poorer treatment response in major depression.

RESULTS

Decreased activation was associated with lower remission rates in the raw analyses and in a logistic regression model adjusted for baseline severity and subsyndromal manic symptoms (odds ratio = 0.899; p = 0.015). The manic features also predicted lower remission (odds ratio = 0.934; p < 0.001). Remission rates were similar in the two treatment groups.

CONCLUSION

Decreased activation and subsyndromal manic symptoms predict lower remission rates in bipolar depression. Patients with these features may require specific treatment approaches, but new studies are necessary to identify treatments that could improve outcomes in this population.

Search for Tensor, Vector, and Scalar Polarizations in the Stochastic Gravitational-Wave Background

The detection of gravitational waves with Advanced LIGO and Advanced Virgo has enabled novel tests of general relativity, including direct study of the polarization of gravitational waves. While general relativity allows for only two tensor gravitational-wave polarizations, general metric theories can additionally predict two vector and two scalar polarizations. The polarization of gravitational waves is encoded in the spectral shape of the stochastic gravitational-wave background, formed by the superposition of cosmological and individually unresolved astrophysical sources. Using data recorded by Advanced LIGO during its first observing run, we search for a stochastic background of generically polarized gravitational waves. We find no evidence for a background of any polarization, and place the first direct bounds on the contributions of vector and scalar polarizations to the stochastic background. Under log-uniform priors for the energy in each polarization, we limit the energy densities of tensor, vector, and scalar modes at 95% credibility to Ω_{0}^{T}<5.58×10^{-8}, Ω_{0}^{V}<6.35×10^{-8}, and Ω_{0}^{S}<1.08×10^{-7} at a reference frequency f_{0}=25  Hz.

Treatment outcomes of acute bipolar depressive episode with psychosis

BACKGROUND

The impact of psychosis on the treatment of bipolar depression is remarkably understudied. The primary aim of this study was to compare treatment outcomes of bipolar depressed individuals with and without psychosis. The secondary aim was to compare the effect of lithium and quetiapine, each with adjunctive personalized treatments (APTs), in the psychotic subgroup.

METHODS

We assessed participants with DSM-IV bipolar depression included in a comparative effectiveness study of lithium and quetiapine with APTs (the Bipolar CHOICE study). Severity was assessed by the Bipolar Inventory of Symptoms Scale (BISS) and by the Clinical Global Impression Scale-Severity-Bipolar Version (CGI-S-BP). Mixed models were used to assess the course of symptom change, and Cox regression survival analysis was used to assess the time to remission.

RESULTS

Psychotic features were present in 10.6% (n = 32) of the depressed participants (n = 303). Those with psychotic features had higher scores on the BISS before (75.2 ± 17.6 vs. 54.9 ± 16.3; P < .001) and after (37.2 ± 19.7 vs. 26.3 ± 18.0; P = .003) 6-month treatment. The CGI-S-BP yielded similar results. Participants with and without psychosis had similar course of symptom improvement and similar time to remission. There was no significant difference in the treatment outcomes of lithium (n = 11) and quetiapine (n = 21) among the psychotic subgroup.

CONCLUSION

Bipolar depressive episodes with psychotic features are more severe, and compared to nonpsychotic depressions, present a similar course of improvement. Given the small number of participants presenting psychosis, the lack of statistically significant difference between lithium- and quetiapine-based treatment of psychotic bipolar depressive episodes needs replication in a larger sample.

Introducing an E-learning Solution for Medical Education in Liberia

Background:

The Ebola virus epidemic and civil war in Liberia left the country in need of strengthening the health workforce. E-learning in medical education provides relevant learning opportunities for students, develops faculty competencies, and assists with the retention of healthcare workers. The Stellenbosch University Rural Medical Education Partnership Initiative (SURMEPI), the College of Health and Life Sciences (COHLS) at the University of Liberia (UL), and the Health Resources and Services Administration (HRSA) formed a partnership to create an e-learning solution for the COHLS.

Objective:

This article outlines the implementation of an e-learning solution for the COHLS in Monrovia, and describes the challenges met, the key successes achieved, and the lessons learnt.

Methods:

An initial scoping visit to Liberia was followed by three further on-site visits. Problems identified were: very limited or no network and computer resources, no internet connection, intermittent power, and lack of IT skills. We followed an evolutionary approach to infrastructure implementation by trying various solutions before settling on an offsite-hosted solution using Software as a Service (SaaS). Local staff were upskilled to administer this while remote support from Stellenbosch IT was provided. A stable internet connection was established. Staff and students can access the Learning Management System (LMS) 24/7 using mobile devices and laptops. Workshops were held where staff were taught how to produce online teaching material. Each class has at least one teaching assistant to assist lecturers with uploading and indexing material on the LMS.

A benchmarking visit by COHLS faculty to Stellenbosch University took place, during which an e-learning strategic plan was drawn up. Further online workshops were conducted, and teaching materials were placed on the new LMS.

Outcomes:

The intranet that was established consisted of internet connection and software as a service in the form of Office 365, providing access to several products and services. The e-learning model attended to technology and human resources simultaneously. The e-learning strategy aimed to improve teaching and learning at the COHLS, boost the number of qualified doctors, reduce the workload on lecturers, and be scalable in the future.

Conclusion:

It is challenging to implement e-learning in medical education. Inadequate infrastructure, limited bandwidth, lack of skilled IT staff, unreliable power supply, time commitment, and ongoing maintenance all need to be overcome. The creation of an e-learning solution for the COHLS over a period of 15 months was enabled by the common vision and close collaboration of the three partners. This model can potentially be replicated across other faculties in the University of Liberia and other educational institutions in Liberia.