LoRaD: Marginal likelihood estimation with haste (but no waste).

The Lowest Radial Distance (LoRaD) method is a modification of the recently introduced Partition-Weighted Kernel method for estimating the marginal likelihood of a model, a quantity important for Bayesian model selection. For analyses involving a fixed tree topology, LoRaD improves upon the Steppingstone or Thermodynamic Integration (Path Sampling) approaches now in common use in phylogenetics because it requires sampling only from the posterior distribution, avoiding the need to sample from a series of ad hoc power posterior distributions, and yet is more accurate than other fast methods such as the Generalized Harmonic Mean (GHM) method. We show that the method performs well in comparison to the Generalized Steppingstone method on an empirical fixed-topology example from molecular phylogenetics involving 180 parameters. The LoRaD method can also be used to obtain the marginal likelihood in the variable-topology case if at least one tree topology occurs with sufficient frequency in the posterior sample to allow accurate estimation of the marginal likelihood conditional on that topology. [Bayesian; marginal likelihood; phylogenetics.].

Evaluation of a Suspected Overdose Form for Timely Surveillance of Fatal Drug Overdoses, Multnomah County, OR, 2020-2021.

OBJECTIVES: There is a significant delay in finalization of drug overdose deaths, and a need to more quickly identify suspected overdoses to improve public health response. The objective of our study was to describe creation of a suspect overdose form and evaluate its use. DESIGN: Evaluation of a suspected overdose form used to record information related to death investigation with matching to state vital records. We calculated the toxicology turnaround time for matched records, and also calculated sensitivity, specificity, positive predictive value, and negative predictive value of the form compared to vital records as the gold standard. SETTING: Multnomah County, Oregon, deaths investigated by the County Medical Examiner between January 2020 and December 2021. MAIN OUTCOME MEASURE: Sensitivity of the suspected overdose form. RESULTS: We analyzed 2818 matched death records in total during the study period. The average turnaround time for the 1673 records with toxicology results was 101 days. In 2020, sensitivity of the form was 74%, but this increased to nearly 95% in 2021. CONCLUSIONS: Multnomah County's suspected evaluation form provides a timelier indicator of deaths suspected to be from drug overdose, has good sensitivity to detect true overdoses, and can help guide more rapid public health and public safety response activities.

Challenges, Barriers, and Successes of Standardized Report Templates: Results of a Society of Interventional Radiology Survey.

Registry data are being increasingly used to establish treatment guidelines, set benchmarks, allocate resources, and make payment decisions. Although many registries rely on manual data entry, the Society of Interventional Radiology (SIR) is using automated data extraction for its VIRTEX registry. This process relies on participants using consistent terminology with highly structured data in physician-developed standardized reports (SR). To better understand barriers to adoption, a survey was sent to 3,178 SIR members. Responses were obtained from 451 interventional radiology practitioners (14.2%) from 92 unique academic and 151 unique private practices. Of these, 75% used structured reports and 32% used the SIR SR. The most common barriers to the use of these reports include SR length (35% of respondents), lack of awareness about the SR (31%), and lack of agreement on adoption within practices (27%). The results demonstrated insights regarding barriers in the use and/or adoption of SR and potential solutions.

A History and Modern Framework for Quality Improvement in Interventional Radiology.

Quality improvement (QI) initiatives have benefited patients as well as the broader practice of medicine. Large-scale QI has been facilitated by multi-institutional data registries, many of which were formed out of national or international medical society initiatives. With broad participation, QI registries have provided benefits that include but are not limited to establishing treatment guidelines, facilitating research related to uncommon procedures and conditions, and demonstrating the fiscal and clinical value of procedures for both medical providers and health systems. Because of the benefits offered by these databases, Society of Interventional Radiology (SIR) and SIR Foundation have committed to the development of an interventional radiology (IR) clinical data registry known as VIRTEX. A large IR database with participation from a multitude of practice environments has the potential to have a significant positive impact on the specialty through data-driven advances in patient safety and outcomes, clinical research, and reimbursement. This article reviews the current landscape of societal QI programs, presents a vision for a large-scale IR clinical data registry supported by SIR, and discusses the anticipated results that such a framework can produce.

Characterization of the Immune Microenvironment in Inflammatory Breast Cancer Using Multiplex Immunofluorescence.

INTRODUCTION: Inflammatory breast cancer (IBC) is an aggressive form of breast cancer with a poorly characterized immune microenvironment. METHODS: We used a five-colour multiplex immunofluorescence panel, including CD68, CD4, CD8, CD20, and FOXP3 for immune microenvironment profiling in 93 treatment-naïve IBC samples. RESULTS: Lower grade tumours were characterized by decreased CD4+ cells but increased accumulation of FOXP3+ cells. Increased CD20+ cells correlated with better response to neoadjuvant chemotherapy and increased CD4+ cells infiltration correlated with better overall survival. Pairwise analysis revealed that both ER+ and triple-negative breast cancer were characterized by co-infiltration of CD20 + cells with CD68+ and CD4+ cells, whereas co-infiltration of CD8+ and CD68+ cells was only observed in HER2+ IBC. Co-infiltration of CD20+, CD8+, CD4+, and FOXP3+ cells, and co-existence of CD68+ with FOXP3+ cells correlated with better therapeutic responses, while resistant tumours were characterized by co-accumulation of CD4+, CD8+, FOXP3+, and CD68+ cells and co-expression of CD68+ and CD20+ cells. In a Cox regression model, response to therapy was the most significant factor associated with improved patient survival. CONCLUSION: Those results reveal a complex unique pattern of distribution of immune cell subtypes in IBC and provide an important basis for detailed characterization of molecular pathways that govern the formation of IBC immune landscape and potential for immunotherapy.

Perceptions surrounding the possible interaction between physical activity, pollution and asthma in children and adolescents with and without asthma.

A cornerstone of asthma management is maintaining physical activity (PA), but this may lead to increased exposure to, and deeper inhalation of, pollutants. Furthermore, children and adolescents may be more susceptible to the deleterious impacts of such exposures. Despite the recent air quality campaigns and media coverage surrounding the dangers of air pollution to respiratory health, few target children and their understanding of such issues.Using semi structured interviews, understanding of PA, air pollution and their interaction was explored with 25 youth aged 7-17 years. Utilising NVIVO 12 software, an atheoretical, inductive thematic analysis was conducted to identify key themes which were subsequently presented as pen profiles with the number of common responses within a theme indicative of its strength.The majority (88%) of youth's indicated traffic-related air pollution and global manufacturing as key sources of air pollution. Whilst all youths were aware of outdoor pollution, only 52% were aware of indoor air pollutants, of which 62% had asthma. Despite some uncertainty, all youths described pollution in a negative fashion, with 52% linking air pollution to undesirable effects on health, specifically respiratory health. PA in a polluted area was thought to be more dangerous than beneficial by 44%, although 24% suggested the benefits of PA would outweigh any detriment from pollution.Youth are aware of, and potentially compensate for, the interaction between air pollution and PA. Strategies are needed to allow youth to make more informed decisions regarding how to promote PA whilst minimising exposure to air pollution.

An experimental test of Lanchester's models of combat in the neotropical termite Nasutitermes corniger (Blattodea: Termitidae).

Lanchester's models of combat have been invoked to explain the mechanics of group fighting in social animals. Specifically, Lanchester's square law posits that the fighting ability of the group is proportional to the square of the number of combatants. Although used to explain a variety of ecological phenomena, the models have not been thoroughly tested. We tested the Lanchester models using group battles between colonies of the termite Nasutitermes corniger. Our main goals were to determine if mortality rates fit the Lanchester models, and if so, whether the behavioural mechanisms underlying a group's success match those used in deriving the model. We initiated battles between pairs of colonies with different ratios of fighters and recorded deaths over time. We found that the numerically larger army has an advantage, but that the advantage is not as pronounced as predicted by Lanchester's square law. We also video-recorded battles to analyse individual behaviour, which did not support the mechanisms invoked by Lanchester. Instead, the killing power of an individual is increased by the presence of nest-mates, giving the larger group a disproportionate advantage. Although the behavioural mechanisms leading to the advantage may differ, our results still support some of the proposed ecological phenomena.

The WISDOM self-management intervention: A cost-effectiveness analysis to support the transformation of type 2 diabetes care in England.

OBJECTIVES: To assess the cost-effectiveness of the WISDOM self-management intervention for type 2 diabetes compared with care as usual. DESIGN: We performed a difference-in-differences analysis to estimate differences in risk factors for diabetes complications between people in the WISDOM group (n = 25, 276) and a control group (n = 15, 272) using GP records. A decision analytic model was then used to extrapolate differences in risk factors into costs and outcomes in the long term. SETTING: Participating GP practices in West Hampshire and Southampton, UK. PARTICIPANTS: All people diagnosed with type 2 diabetes between January 1990 and March 2020 (n = 40,548). OUTCOMES: Diabetes-related complications, quality-adjusted life years (QALYs) and costs to the English National Health Service at 5 years and lifetime. INTERVENTIONS: The WISDOM intervention included risk stratification, self-management education programme to professionals and people with type 2 diabetes, and monitoring of key treatment targets. RESULTS: WISDOM was associated with less atrial fibrillation [p = 0.001], albuminuria [p = 0.002] and blood pressure [p = 0.098]. Among all people in the intervention group, WISDOM led to 51 [95%CI: 25; 76] QALYs gained and saved £278,036 [95%CI: -631,900; 176,392] in the first 5 years after its implementation compared with care as usual. During those people' lifetime, WISDOM led to 253 [95%CI: 75; 404] QALYs gained and cost saving of £126,380 [95%CI: -1,466,008; 1,339,628]. The gains in QALYs were a result of reduced diabetes-related complications through improved management of the associated risk factors. CONCLUSIONS: The WISDOM risk-stratification and education intervention for type 2 diabetes appear to be cost-effective compared to usual care by reducing diabetes complications.

Risk of myopericarditis following COVID-19 mRNA vaccination in a large integrated health system: A comparison of completeness and timeliness of two methods.

PURPOSE: How completely do hospital discharge diagnoses identify cases of myopericarditis after an mRNA vaccine? METHODS: We assembled a cohort 12-39 year-old patients, insured by Kaiser Permanente Northwest, who received at least one dose of an mRNA vaccine (Pfizer-BioNTech or Moderna) between December 2020 and October 2021. We followed them for up to 30 days after their second dose of an mRNA vaccine to identify encounters for myocarditis, pericarditis or myopericarditis. We compared two identification methods: A method that searched all encounter diagnoses using a brief text description (e.g., ICD-10-CM code I40.9 is defined as 'acute myocarditis, unspecified'). We searched the text description of all inpatient or outpatient encounter diagnoses (in any position) for "myocarditis" or "pericarditis." The other method was developed by the Centers for Disease Control and Prevention's Vaccine Safety Datalink (VSD), which searched for emergency department visits or hospitalizations with a select set of discharge ICD-10-CM diagnosis codes. For both methods, two physicians independently reviewed the identified patient records and classified them as confirmed, probable or not cases using the CDC's case definition. RESULTS: The encounter methodology identified 14 distinct patients who met the confirmed or probable CDC case definition for acute myocarditis or pericarditis with an onset within 21 days of receipt of COVID-19 vaccination. When we extended the search for relevant diagnoses to 30 days since vaccination, we identified two additional patients (for a total of 16 patients) who met the case definition for acute myocarditis or pericarditis, but those patients had been misdiagnosed at the time of their original presentation. Three of these patients had an ICD-10-CM code of I51.4 "Myocarditis, Unspecified;" that code was omitted by the VSD algorithm (in the late fall of 2021). The VSD methodology identified 11 patients who met the CDC case definition for acute myocarditis or pericarditis. Seven (64%) of the 11 patients had initial care for myopericarditis outside of a KPNW facility and their diagnosis could not be ascertained by the VSD methodology until claims were submitted (median delay of 33 days; range of 12-195 days). Among those who received a second dose of vaccine (n = 146 785), we estimated a risk as 95.4 cases of myopericarditis per million second doses administered (95% CI, 52.1-160.0). CONCLUSION: We identified additional valid cases of myopericarditis following an mRNA vaccination that would be missed by the VSD's search algorithm, which depends on select hospital discharge diagnosis codes. The true incidence of myopericarditis is markedly higher than the incidence reported to US advisory committees in the fall of 2021. The VSD should validate its search algorithm to improve its sensitivity for myopericarditis.

Routine in-person post-operative follow-up for uncomplicated laparoscopic appendectomy does not change management.

INTRODUCTION: Eliminating points in the continuum of care that do not change management is a safe strategy for cost containment and workflow efficiency in health systems. As a process improvement initiative, we sought to identify whether routine, outpatient follow-up changes management in laparoscopic appendectomy in a military hospital. METHODS: We performed a retrospective chart review of adult patients undergoing laparoscopic appendectomy during a one-year period. The primary outcome was identification of a change in management during routine in person follow-up. Secondary outcomes included location of patient presentation with a post-operative event (clinic, emergency department, primary care provider), and if those visits changed management. Events were defined as any deviation from the typical post-operative course within 6 weeks of surgery, including abnormal specimen pathology. RESULTS: One-hundred and seventy-six appendectomies were performed over one year, and 148 patients met inclusion criteria (median age = 27, 66.9% male). Perforation was identified in 10.1% of patients. Seventeen-point-five percent of patients had a post-operative event, of which persistent pain was the most common. Only 2.0% of all patients saw a change in management at their routine in person follow-up appointment. Eighty percent of patients with any post-operative events sought care outside of their routine in person follow up appointments. No variable was independently associated with a change in management. CONCLUSION: Routine in-person clinical follow-up for laparoscopic appendectomy almost never changes management. Perforated appendicitis may be an indication for in-person follow-up. Considering a telemedicine model for post-operative follow-up of laparoscopic appendectomy patients will provide a safe and effective alternative to in-person clinic visits, while saving patients time and allowing providers the clinic freedom to prioritize more urgent and new patients.

Dysphagia after Stroke: An Unmet Antibiotic Stewardship Opportunity.

The goal of antibiotic stewardship is to improve antibiotic use, often by reducing unnecessary treatment. Bedside dysphagia screening tools help identify patients at high risk of aspiration following stroke. Presence of dysphagia does not indicate a need for antibiotic treatment. Therefore, this retrospective, cohort study was developed to evaluate the association of dysphagia and antibiotic prescribing following stroke. There were 117 patients included. Patients were placed into 2 cohorts based on the results of the dysphagia screening, with 55 patients positive for dysphagia and 62 patients negative for dysphagia. Patients with dysphagia tended to be older, had higher National Institutes of Health stroke scores, and lower renal function. Patients with dysphagia were prescribed more empiric antibiotics than those without dysphagia (18.2% vs. 3.2%, p = 0.01). This resulted in 53 antibiotic days of therapy in the dysphagia cohort compared to 19 antibiotic days of therapy in the no dysphagia cohort (p = 0.1). No patients later developed pneumonia and only one patient was started antibiotics after 48 h. Two cases of Clostridioides difficile were reported. Both patients were in the dysphagia cohort and received antibiotics. Multivariable logistic regression demonstrated that positive chest x-ray findings and failed dysphagia screen were independent conditions associated with initiating antibiotics. These findings indicate that antibiotic use was higher in patients following stroke with a positive dysphagia screen. Close monitoring of stroke patients, particularly when positive for dysphagia, might be an under-recognized antibiotic stewardship opportunity.

Does Early Secondary Alveolar Bone Grafting Influence Need for Additional Maxillary Advancement Procedures in Cleft Lip and Palate?

OBJECTIVE: To determine if secondary alveolar bone grafting (SABG) timing in patients with cleft lip and palate (CLP) influences the future need for additional maxillary advancement procedures, particularly Le Fort I osteotomy with rigid external distraction (RED). DESIGN: Retrospective cohort study. Groups were separated by SABG timing: early mixed dentition (ages 68 years) or late mixed dentition (ages 9-11 years). The criterion for RED was negative overjet ≥8 mm, and sufficient dental development for RED. SETTING: Single tertiary care institution. PATIENTS: Patients with CLP that underwent SABG from 2010 to 2015. Exclusion criteria included syndromic conditions, SABG surgery at age >12 years, current age <12 years, and <2 years follow-up. 104 patients were included. MAIN OUTCOME MEASURES: The number of RED candidates and treated patients. RESULTS: There was no statistical difference in the number of RED candidates (P = .0718) nor treated patients (P = .2716) based on SABG timing; stratification by laterality was also insignificant. Early SABG is associated with higher odds of being a RED candidate (pooled, unilateral, bilateral) and treated patient (pooled and unilateral); however, there were no statistically significant associations between SABG timing and the number of RED candidates and treated patients as determined by logistic regression models. CONCLUSION: There is no statistically significant association between SABG timing and the odds of being a RED candidate or treated patient. Future prospective studies are recommended to assess the relationship between SABG timing and maxillary growth in patients with CLP.

New partition based measures for data compatibility and information gain.

It is of great practical importance to compare and combine data from different studies in order to carry out appropriate and more powerful statistical inference. We propose a partition based measure to quantify the compatibility of two datasets using their respective posterior distributions. We further propose an information gain measure to quantify the information increase (or decrease) in combining two datasets. These measures are well calibrated and efficient computational algorithms are provided for their calculations. We use examples in a benchmark dose toxicology study, a six cities pollution data and a melanoma clinical trial to illustrate how these two measures are useful in combining current data with historical data and missing data.

Risk Factor Evaluation for Methicillin-Resistant Staphylococcus aureus and Pseudomonas aeruginosa in Community-Acquired Pneumonia.

BACKGROUND: The 2019 community-acquired pneumonia guidelines recommend using recent respiratory cultures and locally validated epidemiology plus risk factor assessment to determine empirical coverage of methicillin-resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa. OBJECTIVE: To develop a methodology for evaluating local epidemiology and validating local risk factors for P aeruginosa and MRSA. METHODS: This multicenter, retrospective cohort evaluated adult patients admitted for pneumonia. Risk factors for MRSA and P aeruginosa were evaluated using multivariable logistic regression and reported as adjusted odds ratios (aORs). RESULTS: There were 10 723 cases evaluated. Lung abscess/empyema had the highest odds associated with MRSA (aOR = 4.24; P < 0.0001), followed by influenza (aOR = 2.34; P = 0.01), end-stage renal disease (ESRD; aOR = 2.09; P = 0.006), illicit substance use (aOR = 1.7; P = 0.007), and chronic obstructive pulmonary disease (COPD; aOR = 1.26; P = 0.04). For P aeruginosa, the highest odds were in bronchiectasis (aOR = 6.13; P < 0.0001), lung abscess/empyema (aOR = 3.36; P = 0.005), and COPD (aOR = 1.84; P < 0.0001). Isolated COPD without other risk factors did not pose an increased risk of either organism. CONCLUSION AND RELEVANCE: Influenza, ESRD, lung abscess/empyema, and illicit substance use were local risk factors for MRSA. Bronchiectasis and lung abscess/empyema were risk factors for Pseudomonas. COPD was associated with MRSA and Pseudomonas. However, isolated COPD had similar rates of MRSA and Pseudomonas pneumonia compared with the total population. This study established a feasible methodology for evaluating local risk factors.

Breakthrough venous thromboembolic events in five patients with COVID-19 on direct oral anticoagulants.

WHAT IS KNOWN AND OBJECTIVE: Coronavirus disease 2019 (COVID-19) is associated with increased risk of venous thromboembolism (VTE). Guidance for VTE prophylaxis continues to evolve, including addressing direct oral anticoagulants (DOACs) continued upon hospitalization. CASE SUMMARIES: We present 5 patients hospitalized for COVID-19 while on DOACs. Four patients had atrial fibrillation and had a previous VTE. Four patients developed acute VTE and one developed stroke-like symptoms. Monitoring D-dimer assisted with the detection of VTE. Three patients died, and two were discharged alive. WHAT IS NEW AND CONCLUSION: Therapeutic failure with DOACs appears to be commonplace in COVID-19. Further research is needed to determine whether there is an underlying cause to this association.

Utility of the respiratory viral panel as an antimicrobial stewardship tool.

WHAT IS KNOWN AND OBJECTIVE: The development of rapid diagnostics has revolutionized antimicrobial stewardship with efforts targeting earlier de-escalation or discontinuation of antibiotics. The respiratory viral panel (RVP) is one tool quickly able to detect common viral and bacterial pathogens using polymerase chain reaction technology. Utility may be further enhanced in conjunction with procalcitonin (PCT). However, the optimal use of the RVP to the clinical pharmacist in the treatment of community-acquired respiratory infections remains unclear. METHODS: The purpose of this guide is to review the available literature regarding the impact of the RVP with and without procalcitonin on antimicrobial stewardship efforts and to provide guidance on how to use each of these tools. RESULTS AND DISCUSSION: In total, 13 studies were included, 5 of which utilized PCT in conjunction with RVP and 8 of which did not use PCT. The majority of studies were retrospective in nature, and the most common outcomes evaluated were antibiotic days of therapy (DOT) and time to antibiotic discontinuation. WHAT IS NEW AND CONCLUSION: After review, RVP alone has limited value to antimicrobial stewardship; however, when used in conjunction with procalcitonin, RVP has the potential to reduce antibiotic use and duration.

Pediatric interventional radiology workforce in North America: a descriptive analysis of demographics, educational backgrounds and scholarly activities.

BACKGROUND: Pediatric interventional radiology has grown as an advanced subspecialty with increased demand, number and complexity of cases, and number of pediatric institutions offering a pediatric interventional radiology service. Despite the overall increase in the number of pediatric interventionalists over the past two decades, there is a heterogeneity in their academic backgrounds and a lack of uniform training pathways. OBJECTIVE: To analyze the demographics, academic backgrounds and scholarly activities of pediatric interventionalists across the United States (U.S.) and Canada. MATERIALS AND METHODS: A list of all members of the Society for Pediatric Interventional Radiology was obtained and pediatric interventionalists at academic and private practice institutions in the U.S. and Canada were included. Publicly available online sources were used to gather demographic and educational information about each pediatric interventionalist, which included the online curriculum vitae, the HealthGrades.com and Doximity.com websites, and Elsevier's Scopus database. Demographic and educational data including age, gender, educational background, additional degrees, academic rank, previous leadership positions, and metrics of scholarly activities were recorded. Fellowships in diagnostic pediatric radiology, adult interventional radiology and/or pediatric interventional radiology were recorded. Mann-Whitney U tests and Kruskal-Wallis tests were used to compare differences between groups. RESULTS: One hundred and twenty-five pediatric interventionalists were included, of whom 24 (19.2%) were female. The mean age was 48.6 years (standard deviation [SD]: 10.6, median: 45 years, range: 36-82 years). There was no statistical difference between median age for male versus female pediatric interventionalists (44.5 years vs. 45 years, P=0.89). A majority of pediatric interventionalists were American medical school graduates (96, 76.8%), while 29 (23.2%) were international medical graduates. Eighty-three percent (104) of the pediatric interventionalists completed diagnostic radiology residency training in the U.S., most commonly at the University of Cincinnati in Ohio (6.4%) and Washington University in St. Louis, MO (5.6%). Among fellowship training, pediatric interventionalists completed a pediatric radiology fellowship (61.6%), adult interventional radiology fellowship (40%) and/or a dedicated pediatric interventional radiology fellowship (57.6%). The mean±SD (median) publications, citations and Hirsch index (h-index) for pediatric interventionalists were 32±45 (12), 68±1,317 (120) and 9±10 (5), respectively. There was a statistically higher number of publications, citations and h-index with increasing academic rank at the assistant, associate and professor levels (P<0.001 for all groups). International medical graduate pediatric interventionalists had a higher, but not statistically significant, median publication count (26 vs. 11, P=0.0.25), citation count (236 vs. 93, P=0.36) and h-index (9.0 vs. 5, P=0.24) compared to pediatric interventional radiologists from American medical schools. CONCLUSION: Pediatric interventionalists in North America are predominantly male, with about a quarter having graduated from international medical schools. Pediatric radiology fellowship, followed by pediatric interventional radiology fellowship, was the most frequently pursued training pathway.

Mitigation of radiation exposure during surgical hepatectomy after yttrium-90 radioembolization.

Yttrium-90 (Y-90) radioembolization for the treatment of hepatocellular carcinoma can present safety challenges when transplanting recently treated Y-90 patients. To reduce surgeons' contact with radioactive tissue and remain within occupational dose limits, current guidelines recommend delaying transplants at least 14 days, if possible. We wanted to determine the level of radiation exposure to the transplant surgeon when explanting an irradiated liver before the recommended decay period. Anex-vivoradiation exposure analysis was conducted on the explanted liver of a patient who received Y-90 therapy 46 h prior to orthotopic liver transplant. To estimate exposure to the surgeon's hands, radiation dosimeter rings were placed inside three different surgical glove configurations and exposed to the explanted liver. Estimated radiation doses corrected for Y-90 decay were calculated. Radiation safety gloves performed best, with an average radiation exposure rate of 5.36 mSV h-1in the static hand position, an 83% reduction in exposure over controls with no glove (31.31 mSv h-1). Interestingly, non-radiation safety gloves also demonstrated reduced exposure rates, well below occupational regulation limits. Handling of Y-90 radiated organs within the immediate post-treatment period can be done safely and does not exceed federal occupational dose limits if appropriate gloves and necessary precautions are exercised.

Stability of Ampicillin in Normal Saline Following Refrigerated Storage and 24-Hour Pump Recirculation.

OBJECTIVE: Use of ampicillin in outpatient parenteral antimicrobial therapy (OPAT) has historically been complicated by frequent dosing and limited stability. The purpose of this study was to evaluate stability of ampicillin using high-pressure liquid chromatography (HPLC) in an OPAT dosing model using continuous infusion at room temperature over 24 hours immediately following preparation compared with batches stored under refrigeration for 24 hours, 72 hours, and 7 days. METHODS: An HPLC method was developed and validated as stability indicating using guidance in USP general Chapter <1225>. Four ampicillin batches were prepared for each experimental condition (immediate use and refrigerated storage for 24 hours, 72 hours, and 7 days). A pump was used to recirculate the solutions through medical-grade tubing for 24 hours. Triplicate 1-mL aliquots were removed from each batch at time 0, 4, 8, 12, and 24 hours and analyzed for ampicillin concentration. RESULTS: Each batch was assayed for initial concentration (20.34-21.50 mg/mL), and percent recovery compared with that concentration thereafter. For the duration of infusion, the average recoveries were 96.4%, 95.8%, 94.6%, and 90.3% for immediate use, 24-hour storage, 72-hour storage, and 7-day storage, respectively. The recovery remained above 90% for all batches and time points, except for 7-day storage, which fell below 90% after 4 hours of circulation. CONCLUSION: Ampicillin can be prepared and stored in a refrigerator for up to 72 hours prior to continuously infusing at room temperature over 24 hours with less than a 10% loss of potency over the dosing period. This model supports twice weekly OPAT delivery of ampicillin.

Assessing Combinability of Phylogenomic Data Using Bayes Factors.

With the rapid reduction in sequencing costs of high-throughput genomic data, it has become commonplace to use hundreds of genes to infer phylogeny of any study system. While sampling a large number of genes has given us a tremendous opportunity to uncover previously unknown relationships and improve phylogenetic resolution, it also presents us with new challenges when the phylogenetic signal is confused by differences in the evolutionary histories of sampled genes. Given the incorporation of accurate marginal likelihood estimation methods into popular Bayesian software programs, it is natural to consider using the Bayes Factor (BF) to compare different partition models in which genes within any given partition subset share both tree topology and edge lengths. We explore using marginal likelihood to assess data subset combinability when data subsets have varying levels of phylogenetic discordance due to deep coalescence events among genes (simulated within a species tree), and compare the results with our recently described phylogenetic informational dissonance index (D) estimated for each data set. BF effectively detects phylogenetic incongruence and provides a way to assess the statistical significance of D values. We use BFs to assess data combinability using an empirical data set comprising 56 plastid genes from the green algal order Volvocales. We also discuss the potential need for calibrating BFs and demonstrate that BFs used in this study are correctly calibrated.