Search

In situations featuring uncertainty about action-reward contingencies, mammals exhibit a high degree of flexibility in adopting strategies for decision-making that are tuned in response to the conditions that they encounter. Although the cortico-basal ganglia thalamic (CBGT) network is implicated in information processing during decisions, it features a complex synaptic architecture, comprised of multiple feed-forward, reciprocal, and feedback pathways, that complicate efforts to elucidate the roles of specific CBGT populations in the process of evidence accumulation. In this paper we apply a strategic sampling approach, based on Latin hypercube sampling, to explore how variations in CBGT network properties, including subpopulation firing rates and synaptic weights, map to variability of parameters in a normative drift diffusion model (DDM), representing algorithmic aspects of information processing during decision-making. Through the application of canonical correlation analysis, we find that this relationship can be characterized in terms of three low-dimensional control ensembles within the CBGT network that impact specific qualities of the emergent decision policy: responsiveness (associated with overall activity in corticothalamic and direct pathways), pliancy (associated largely with overall activity in components of the indirect pathway of the basal ganglia), and choice (associated with differences in direct and indirect pathways across action channels). These analyses provide key mechanistic predictions about the roles of specific CBGT network elements in tuning information processing dynamics during decisions.Author summaryMammals are continuously subjected to uncertain situations in which they have to choose among behavioral options. The cortico-basal ganglia-thalamic (CBGT) circuit is a complicated collection of interconnected nuclei believed to strongly influence the ability to adapt to environmental changes. The roles of specific CBGT components in controlling information during decisions remains unclear. At a more phenomenological, algorithmic level, drift-diffusion models have been shown to be able to reproduce behavioral data (action selection probabilities and the time needed to make a decision) obtained experimentally from mammals and to provide an abstract representation of a decision policy. In this work, we use simulated decision-making to establish a mapping from neural activity in the CBGT circuit to behavioral outcomes. This mapping illuminates the importance of three core sets of CBGT subnetworks in the action selection process and how they are involved in adapting decision policies across exploitative and exploratory situations.

The global poultry industry has grown to the extent that the number of chickens now well exceeds the number of humans on Earth.

Humans and other mammals flexibly select actions under noisy and unstable conditions. To shed light on the mechanism driving this flexibility, we evaluated how the underlying decision policy evolves when humans change their minds about the most rewarding action. Participants performed a dynamic variant of the two-armed bandit task that manipulated the certainty in relative reward probabilities (conflict) and the reliability of action-outcome contingencies (volatility). We found that conflict and volatility contributed to shifts in exploratory states by changing both the rate of evidence accumulation (drift rate) and the amount of evidence needed to make a decision (boundary height). Following a switch in the optimal choice, the drift rate and the boundary height reduce, allowing variability in the accumulation process to predominate action selection, leading to a fast exploratory state. These changes facilitate the discovery of the new optimal choice, with a quick recovery of the boundary height to baseline. In parallel, the drift rate gradually returns to its asymptotic value as the belief in the value of the optimal choice stabilizes. Together, these decision dynamics suggest that, in the context of volatile two-choice decisions, humans adopt a combined information-threshold and drift rate mechanism in response to environmental changes. Unlike previous observations, we found no evidence that fluctuations in norepinephrine, as measured by pupillometry, associated with this adaptive shift toward an exploratory policy. We conclude that the multifaceted processes underlying a decision can rapidly reconfigure to adapt action selection policy under multiple forms of environmental uncertainty.

Patients with classic hemophilia can develop joint hemarthroses, degenerative changes, and eventually require total hip arthroplasty (THA). Little data exist concerning THA outcomes in this population, and evidence-based guidelines specifically addressing venous thromboembolism (VTE) prophylaxis in this population are lacking.A retrospective study was conducted using the 2010-2020 PearlDiver MHip database. Patients undergoing primary THA were identified, and those with classic hemophilia were matched 1:10 with non-hemophilia patients based on age, gender, and Elixhauser Comorbidity Index. Ninety-day serious adverse events, minor adverse events, and any adverse events were compared with multivariate analysis. Reoperation at 5 years was assessed using Kaplan-Meier analysis.Five hundred eighteen classic hemophilia THA patients were matched 1:10 with 5,193 non-hemophilia patients. On multivariate analysis, those with classic hemophilia had greater odds of aggregated any adverse events (odds ratio [OR] 1.76), serious adverse events (OR 2.30), and minor adverse events (OR 1.52) (P.001 for each). Patients with classic hemophilia had greater odds of bleeding issues (transfusion, OR 1.98; hematoma, OR 4.23; P.001 for both), VTE (deep vein thrombosis, OR 2.67; pulmonary embolism, OR 4.01; P.001 for both), and acute kidney injury (OR 1.63; P = .03). Five-year implant survival was lower in hemophilia patients (91.9%) relative to matched controls (95.3%; P = .009).Hemophilia patients undergoing THA had elevated risks of both 90-day bleeding complications (transfusion and hematoma) and VTE (deep vein thrombosis and pulmonary embolism) relative to matched controls. These findings emphasize the need to balance factor replacement and VTE prophylaxis. Although the 5-year implant survival was lower in hemophilia patients, this represented a difference of 3.4% at 5 years, suggesting that THA remains effective in this cohort.

Inspiratory breathing rhythms arise from synchronized neuronal activity in a bilaterally distributed brainstem structure known as the preBötzinger complex (preBötC). In in vitro slice preparations containing the preBötC, extracellular potassium must be elevated above physiological levels (to 7 − 9 mM) to observe regular rhythmic respiratory motor output in the hypoglossal nerve to which the preBötC projects. Reexamination of how extracellular K+ affects preBötC neuronal activity has revealed that low amplitude oscillations persist at physiological levels. These oscillatory events are sub-threshold from the standpoint of transmission to motor output and are dubbed burstlets. Burstlets arise from synchronized neural activity in a rhythmogenic neuronal subpopulation within the preBötC that in some instances may fail to recruit the larger network events, or bursts, required to generate motor output. The fraction of subthreshold preBötC oscillatory events (burstlet fraction) decreases sigmoidally with increasing extracellular potassium. These observations underlie the burstlet theory of respiratory rhythm generation. Experimental and computational studies have suggested that recruitment of the non-rhythmogenic component of the preBötC population requires intracellular Ca2+ dynamics and activation of a calcium-activated non-selective cationic current. In this computational study, we show how intracellular calcium dynamics driven by synaptically triggered Ca2+ influx as well as Ca2+ release/uptake by the endoplasmic reticulum in conjunction with a calcium-activated non-selective cationic current can explain all of the key observations underlying the burstlet theory of respiratory rhythm generation. Thus, we provide a mechanistic basis to unify the experimental findings on rhythm generation and motor output recruitment in the preBötC.

ObjectivesThe use of external control arms to study treatment effects is growing in interest among drug sponsors and regulators. However, experience with performing these kinds of studies for complex, immune-mediated diseases is limited. We sought to analyze a retrospective cohort of Crohn’s patients to predict the outcome of a prospective cohort.MethodsWe queried electronic health records databases and screened records at the University of California, San Francisco to identify patients meeting the eligibility criteria of TRIDENT, a concurrent trial involving ustekinumab as a reference arm. Timepoints were defined to balance the tradeoff between missing disease activity and bias. We compared two imputation models by their impacts on cohort membership and outcomes. We compared the results of ascertaining disease activity using structured data algorithms against manual review. We used these data to estimate ustekinumab’s real-world effectiveness.ResultsScreening identified 183 patients. 30% of the cohort had missing baseline data. Two imputation models were tested and had similar effects on cohort definition and outcomes. Algorithms for ascertaining non-symptom-based elements of disease activity were similar in accuracy to manual review. The final cohort consisted of 56 patients. 34% of the cohort was in steroid-free clinical remission by week 24.ConclusionsWe predict that a third of the ustekinumab-treated cohort in TRIDENT will be in steroid-free remission by week 24. However, our prediction is limited by substantial missing data. Efforts to improve real-world data capture and align trial design with clinical practice may enable more robust future studies and improve trial efficiency.STUDY HIGHLIGHTSWHAT IS KNOWNExternal control arm studies are receiving growing interest from drug sponsors and regulators as a potential source of real-world evidenceHowever, the feasibility and robustness of this approach is currently limitedUstekinumab is an FDA-approved treatment of moderately to severely active Crohn’s diseaseWHAT IS NEW HEREWe derived a retrospective cohort of patients designed to resemble the participants of TRIDENT, a concurrent phase 2b trial using ustekinumab as a reference armWe predict that about 34% of the ustekinumab-assigned participants in TRIDENT will be in steroid-free clinical remission by week 24.EHR structured data algorithms may be an accurate and less laborious alternative to manual abstraction of non-symptom-based components of the Crohn’s Disease Activity IndexReal-world practice differs from controlled studies in important ways, including the treatment goals and the timing of encountersThese differences can pose challenges to the feasibility of external control arm studies, and must be addressed to enable this novel study designThe methods, data, and code used in this pilot study are shared here for reproducibility and enhancement by others

Unicompartmental knee arthroplasty (UKA) may be considered for select patients to relieve pain and restore function of the knee joint. Little research to date has explored the complication profile of UKA in an older population. The current study uses a large national surgical database to examine the 30-day postoperative adverse events in octogenarians compared with those in nonoctogenarians.The 2012-2018 National Surgical Quality Improvement Program database was queried for all patients undergoing UKA for osteoarthritis. Those patients aged 80 years or older composed the octogenarian age group. Demographics and medical comorbidities were cataloged, in addition to 30-day adverse events. Multivariate regression analysis controlled for differences in demographics and comorbidities. Significance was set atA total of 10,103 patients undergoing UKA were identified, of which 728 (7.2%) were octogenarians. The octogenarian cohort had significantly higher comorbidity burden than nonoctogenarians. After controlling for demographics other than age, American Society of Anesthesiologists score, and medical comorbidities, octogenarians had higher 30-day odds of death (odds ratio [OR] = 6.12,The present study found a statistically significant increase in several adverse events within 30 days of surgery for patients aged ≥80 years when compared with patients younger than 80 years. Namely, UKA in octogenarians was associated with significantly increased odds of short-term mortality, urinary tract infection, transfusion, prolonged hospital stay, and readmission.

IntroductionStructural and functional brain connectomes built using macroscale data collected through magnetic resonance imaging (MRI) may contain noise that contributes to false-positive edges, which can obscure structure-function relationships with implications for data interpretation. Thresholding procedures are routinely applied in practice to optimize network density by removing low-signal edges, but there is limited consensus regarding the appropriate selection of thresholds. We compare existing methods and propose a novel alternative objective function thresholding (OFT) method.MethodsThe performance of thresholding approaches, including a percolation-based approach and an objective function-based approach, is assessed by (a) computing the normalized mutual information (NMI) of community structure between a known network and a simulated, perturbed networks to which various forms of thresholding have been applied, and (b) comparing the density and the clustering coefficient (CC) between the baseline and thresholded networks.ResultsIn our analysis, the proposed objective function-based threshold exhibits the best performance in terms of high similarity between the underlying networks and their perturbed, thresholded counterparts, as quantified by NMI and CC analysis on the simulated functional networks.DiscussionExisting network thresholding methods yield widely different results when graph metrics are computed. Thresholding based on the objective function appears to maintain a set of edges such that the resulting network shares the community structure and clustering features present in the original network. This outcome provides proof-of-principle evidence that thresholding based on the objective function could offer a useful approach to reducing the network density of functional connectivity data.Impact StatementNetwork thresholding refers to removing edges between node pairs in a functional network that have weak edge-weights that may arise from unwanted variability or noise. Since edge-weight cutoffs used to generate a binary network can be sensitive to thresholding, we introduce a novel thresholding algorithm. We find that when applied to networks derived via perturbations, namely through simulated functional connectivity of a known network, this approach yields a binary network that is more similar to the known network compared to using existing thresholding approaches. Thus, our algorithm is a competitive candidate for use in thresholding of brain connectome.

Knowledge of microbial gene functions comes from manipulating the DNA of individual strains in isolation from their natural communities. While this approach to microbial genetics has been foundational, its requirement for culturable microorganisms has left the majority of microbes and their interactions genetically unexplored. Here, we describe a generalizable strategy for editing the genomes of specific organisms within microbial communities. We identified genetically tractable bacteria within a community using Environmental Transformation Sequencing (ET-Seq), an approach in which non-targeted transposon integrations are mapped and quantified following community delivery. We next developed and used DNA-editing All-in-one RNA-guided CRISPR-Cas Transposase (DART) systems for targeted DNA insertion into organisms identified as tractable by ET-Seq, enabling organism- and locus-specific genetic manipulation within the community context. To illustrate the utility of our approach, we selectively edited closely related strains, measured gene fitness, and enriched targeted members within soil and infant gut microbiota. These results establish a new paradigm for targeted community editing relevant to research and applications on medical, agricultural, and industrial microbiomes.

INTRODUCTION: The coronavirus 2019 (COVID-19) pandemic disease has imposed an unprecedented degree of stress on healthcare systems. This study aimed to understand whether COVID-19 positivity is associated with an increased risk of adverse outcomes after geriatric hip fracture surgery. METHODS: From a national administrative claims data set, patients who underwent hip fracture surgery from April 1, 2020, to December 1, 2020 were selected for analysis. COVID-19-positive status was assessed by the emergency International Classification of Diagnoses, 10th Revision, COVID-19 code within 2 weeks before the surgery. Demographic, comorbidity, and 30-day postoperative adverse event information were extracted. Logistic regression before and after 10:1 propensity matching was performed to identify patient risk factors associated with the occurrence of postoperative adverse events. RESULTS: Of 42,002 patients who underwent hip fracture surgery, 678 (1.61%) were identified to be positive for COVID-19 infection. No significant differences in age, sex, and procedure type were found between COVID-19-positive and COVID-19-negative groups, but the COVID-19-positive patients demonstrated a higher incidence of several comorbidities. These differences were no longer significant after matching. After matching, the COVID-19-positive group had a higher incidence of any, serious, and minor adverse events (P < 0.001 for all). Controlling for preoperative variables, COVID-19 positivity was associated with an increased risk of experiencing any adverse events (odds ratio [OR] = 1.62, 95% confidence interval [95% CI] = [1.37 to 1.92], P < 0.001), serious adverse events (OR = 1.66, 95% CI = [1.31 to 2.07], P < 0.001), and minor adverse events (OR = 1.59, 95% CI = [1.34 to 1.89], P < 0.001). DISCUSSION: After matching and controlling for confounding variables, COVID-19-positive hip fracture patients had increased odds of multiple postoperative events. Clinicians caring for this vulnerable geriatric population should be mindful of this risk to improve the care for these patients during the ongoing global pandemic.

Staphylococcus pseudintermedius colonizes and is a pathogen of dogs and is being increasingly recognized from specimens from humans with various infections. We describe a case of S. pseudintermediu...

Staphylococcus pseudintermedius is a well known commensal organism of dogs but also a canine opportunistic pathogen. Reports of this organism being recovered from specimens from humans might suggest an increase prevalence in human infections and/or improved diagnostic leading to more accurate identification. Here we report a case of persistent S. pseudintermedius infection in an adult female oncology patient including colonization of the tip of an indwelling catheter. Diligence by laboratories in correctly isolating and identifying this pathogen (including susceptibility testing) is essential for optimal patient care.

Purpose There is a need to improve delivery of family planning services, including preconception and contraception services, in primary care. We assessed whether a clinician-facing clinical decision support implemented in a family medicine staffed primary care network improved provision of family planning services for reproductive-aged female patients, and differed in effect for certain patients or clinical settings. Methods We conducted a pragmatic study with difference-in-differences design to estimate, at the visit-level, the clinical decision support’s effect on documenting the provision of family planning services 52 weeks prior to and after implementation. We also used logistic regression with a sample subset to evaluate intervention effect on the patient-level. Results 27,817 eligible patients made 91,185 visits during the study period. Overall, unadjusted documentation of family planning services increased by 2.7 percentage points (55.7% pre-intervention to 58.4% intervention). In the adjusted analysis, documentation increased by 3.4 percentage points (95% CI: 2.24, 4.63). The intervention effect varied across sites at the visit-level, ranging from a −1.2 to +6.5 percentage point change. Modification of effect by race, insurance, and site were substantial, but not by age group nor ethnicity. Additionally, patient-level subset analysis showed that those exposed to the intervention had 1.26 times the odds of having family planning services documented after implementation compared to controls (95% CI: 1.17, 1.36). Conclusions This clinical decision support modestly improved documentation of family planning services in our primary care network; effect varied across sites. Implications Integrating a family planning services clinical decision support into the electronic medical record at primary care sites may increase the provision of preconception and/or contraception services for women of reproductive age. Further study should explore intervention effect at sites with lower initial provision of family planning services.

Articular cartilage injury, as a hallmark of arthritic diseases, is difficult to repair and causes joint pain, stiffness, and loss of mobility. Over the years, the most significant problems for the drug-based treatment of arthritis have been related to drug administration and delivery. In recent years, much research has been devoted to developing new strategies for repairing or regenerating the damaged osteoarticular tissue. The RNA interference (RNAi) has been suggested to have the potential for implementation in targeted therapy in which the faulty gene can be edited by delivering its complementary Short Interfering RNA (siRNA) at the post-transcriptional stage. The successful editing of a specific gene by the delivered siRNA might slow or halt osteoarthritic diseases without side effects caused by chemical inhibitors. However, cartilage siRNA delivery remains a challenging objective because cartilage is an avascular and very dense tissue with very low permeability. Furthermore, RNA is prone to degradation by serum nucleases (such as RNase H and RNase A) due to an extra hydroxyl group in its phosphodiester backbone. Therefore, successful delivery is the first and most crucial requirement for efficient RNAi therapy. Nanomaterials have emerged as highly advantage tools for these studies, as they can be engineered to protect siRNA from degrading, address barriers in siRNA delivery to joints, and target specific cells. This review will discuss recent breakthroughs of different siRNA delivery technologies for cartilage diseases.

We recently derived a method, local orthogonal rectification (LOR), that provides a natural and useful geometric frame for analyzing dynamics relative to a base curve in the phase plane for two-dimensional systems of ODEs (Letson and Rubin, SIAM J. Appl. Dyn. Syst., 2018). This work extends LOR to apply to any embedded base manifold in a system of ODEs of arbitrary dimension and establishes a corresponding system of LOR equations for analyzing dynamics within the LOR frame, which maps naturally back to the original phase space. The LOR equations encode geometric properties of the underlying flow and remain valid, in general, beyond a local neighborhood of the embedded manifold. In addition to developing a general theory for LOR that makes use of a given normal frame, we show how to construct a normal frame that conveniently simplifies the computations involved in LOR. Finally, we illustrate the utility of LOR by showing that a blow-up transformation on the LOR equations provides a useful decomposition for studying trajectories' behavior relative to the embedded base manifold and by using LOR to identify canard behavior near a fold of a critical manifold in a two-timescale system.

STUDY DESIGN Retrospective cohort study OBJECTIVE.: The aim of this study was to investigate how elective spine surgery patient preoperative opioid use (as determined by admission NarxCare narcotics use scores) correlated with 30-day perioperative outcomes and postoperative patient satisfaction. SUMMARY OF BACKGROUND DATA The effect of preoperative narcotics usage on postoperative outcomes and patient satisfaction following spine surgery has been of question. The NarxCare platform analyzes the patients' state Physician Drug Monitoring Program (PDMP) records to assign numerical scores that approximate a patient's overall opioid drug usage. METHODS Elective spine surgery cases performed at a single institution between October 2017 and March 2018 were evaluated. NarxCare narcotics use scores at the time of admission were assessed. Patient characteristics, as well as 30-day adverse events, readmissions, reoperations, and mortality, were abstracted from the medical record. Hospital Consumer Assessment of Healthcare Providers and Systems (HCAHPS) survey data were also abstracted when available.Cases were binned based on the following ranges of admission NarxCare scores: 0, 1 to 99, 100 to 299, 300 to 499, and 500+. Multivariate logistic regressions were performed to compare the odds of having an adverse events, readmission, reoperation, and mortality between the different narcotics groups. One-way analysis of variance analyses were performed to compare HCAHPS survey response rates and HCAHPS survey results between the different narcotics score groups. RESULTS In total, 346 patients met criteria for inclusion in the study (NarxScore 0: n = 74, 1-99: n = 58, 300-499: n = 117, and 500+: n = 21). Multivariate logistic regressions did not detect statistically significant differential odds of experiencing adverse events, readmission, reoperation, or mortality between the different groups of admissions narcotics scores. Analyses of variance did not detect statistically significant differences in HCAHPS survey response rates, total HCAHPS scores, or HCAHP subgroup scores between the different narcotics score groups. CONCLUSION Although there are many reasons to address preoperative patient narcotic utilization, the present study did not detect perioperative outcome differences or patient satisfaction based on the narcotic use scores as stratified here. LEVEL OF EVIDENCE 3.

Previous studies have demonstrated varying rates of heterotopic ossification (HO) after total hip arthroplasty (THA) depending on which anatomical approach is utilized. The direct anterior approach (DAA) is considered to be a muscle-sparing approach to the hip, which may lead to decreased rates of HO formation. This study evaluated the incidence of HO formation after DAA THA. The current work is a retrospective review of patients who underwent DAA THA. Six-month postoperative radiographs were evaluated and HO grade was classified using the Brooker classification system. Baseline characteristic differences between the Brooker classification groups were analyzed, specifically looking at: age, sex, type of deep venous thrombosis prophylaxis utilized, and preoperative Bombelli arthritis type. The overall incidence of HO in this DAA group was 179/485 patients (36.9%). There were 14 patients (2.9%) with Brooker Type 3 HO and 1 patient (0.21%) with Brooker Type 4 HO. No surgical excision of HO was performed. Patients were significantly more likely to develop HO if they had Bombelli hypertrophic arthritis (p

The ability of chemotherapeutic agents to affect the growth of common bacterial pathogens and the relationship between the effects of chemotherapeutics and antimicrobials is largely unknown. The purpose of this study was to describe the susceptibility of canine bacterial isolates to chemotherapeutic agents and to compare these results to their antimicrobial susceptibility. The effects of bleomycin, doxorubicin, cytarabine, cyclophosphamide, methotrexate, 5-fluorouracil and gemcitabine on the growth of 33 Staphylococcus pseudintermedius isolates and 32 Escherichia coli isolates from dogs was determined by agar dilution. In addition to MICs, the lowest drug concentration associated with a decreased colony size was recorded. Results were compared to the MICs of a panel of antimicrobial agents. Bleomycin consistently inhibited bacterial growth of S. pseudintermedius and E. coli. Doxorubicin inhibited S. pseudintermedius but not E. coli while the opposite was seen for gemcitabine. Reduction in colony size on exposure to 5-fluorouracil for both organisms, and methotrexate for S. pseudintermedius was seen. No observable effect of cyclophosphamide or cytarabine was observed. Associations between elevated MICs to chemotherapeutic drugs and antimicrobial resistance were not found. These results indicate that chemotherapeutic agents affect the growth of bacteria, but do not support a role in the selection of antimicrobial resistance. SIGNIFICANCE AND IMPACT OF THE STUDY: This study shows that chemotherapy drugs commonly used in veterinary oncology have an effect of the growth of canine isolates of Escherichia coli and Staphylococcus pseudintermedius. No associations between susceptibility to chemotherapeutic drugs and antibiotics were found, which does not support selection of antimicrobial resistance by chemotherapy drugs.

To summarize the safety and feasibility of outpatient total joint arthroplasty (TJA) from the perspectives of short-term complications, long-term functional outcomes, patient satisfaction and financial impact, and to provide evidence-based guidance on how to establish an outpatient TJA programme.TJA has been recently transitioned from an exclusively inpatient procedure for all Medicare and Medicaid patients to an outpatient surgery in properly selected total knee arthroplasty patients. This change may decrease costs while maintaining comparable rates of readmission, adverse events, positive surgical outcomes and patient satisfaction.With a standardized clinical pathway, outpatient TJA can be safe and effective in a subset of patients. Essential components of a successful outpatient TJA programme include proper patient selection, preoperative patient/family education, perioperative multidisciplinary coordination and opioid-sparing analgesia, and early and effective postdischarge planning. More studies are needed to further assess and optimize this new care paradigm.

We study the interaction of two bacterial pulses in a one-dimensional nutrient gradient. Simulations of the Keller–Segel chemotaxis model reveal two qualitatively distinct behaviors. As the two pulses approach one another, they either combine and move as a single pulse or, surprisingly, change direction and begin moving away from each other in the direction from which they originated. To study this phenomenon, we introduce a heuristic approximation to the spatial profiles of the pulses in the Keller–Segel model and derive a system of ordinary differential equations approximating the dynamics of the pulse centers of mass and widths. This approximation simplifies analysis of the global dynamics of the bacterial system and allows us to efficiently explore qualitative behavior changes under a range of parameter variations. We end by presenting experimental data showing that populations of E. coli display behavior that qualitatively agrees with our theoretical results.

Increased complication rate has been reported in Parkinson's disease (PD) patients following total knee arthroplasty (TKA). However, this has not previously been studied on a national scale. The purpose of this study was to determine whether PD patients had increased cost, complication, mortality, and length of stay following TKA using a national database.The HCUP Nationwide Inpatient Sample was evaluated for the years 2000 to 2012. PD patients were matched 1:10 with non-PD control patients for age, sex, Charlson Comorbidity Index (CCI), and year of admission utilizing a propensity score matching procedure. Univariable and multivariable logistic regression were used to determine the relationship between PD and surgical outcomes in the matched cohort.Before matching, TKA patients with PD were significantly older (p 0.0001), more frequently male (p 0.0001), and had a greater CCI (p = 0.3058). In the matched cohort, PD was associated with significantly increased length of stay (3.92 vs 3.71 days, p 0.0001) and total hospital charges ($41,523.52 vs $40,657.00, p = 0.0037). There was no significant difference in in-hospital complication rate (8.28% vs 8.04%, p = 0.4297) or in-hospital mortality (0.164% vs 0.150%, p = 0.8465) between PD patients and matched non-PD patients.Matched cohort analysis demonstrated statistically significant but clinically minor increases in length and cost of hospitalization for TKA in PD patients. Complication rate and in-hospital mortality rate was not higher in PD patients, suggesting that this group may be safely considered for TKA.Prognostic - Level III.

Background The demand for total hip and total knee arthroplasty in the USA is projected to increase significantly. Traditionally, face-to-face physical therapy has been an essential component of recovery in patients after total joint arthroplasty. Emerging technology allows telerehabilitation, or virtual physical therapy, which may reduce costs and increase standardization, but its effects on outcomes are not known. Questions/Purpose We sought to review our initial experience using a telerehabilitation protocol for patients after primary total hip or total knee arthroplasty. Methods In this pilot study, we retrospectively compared our first 40 telerehabilitation patients after a primary total hip or knee arthroplasty with a historical cohort or literature referenced values and evaluated (1) readmission rates at 90 days, (2) emergency department visits, (3) patient-reported outcome scores, (4) incidence of closed knee manipulation within 90 days of primary total knee arthroplasty, and (5) patient satisfaction surveys. Results We observed no increase in the telerehabilitation group at 90 days in readmissions, emergency department visits, or closed knee manipulations. Accuracy of telerehabilitation exercises performed was 92%. Patient-reported outcome scores showed improvements comparable with traditional therapy. Extremely high patient satisfaction scores were reported with the telerehabilitation protocol. Conclusion Our early experience demonstrates the feasibility of implementing a telerehabilitation program following primary total hip or knee arthroplasty without compromising clinical quality and with high patient satisfaction. Electronic supplementary material The online version of this article (10.1007/s11420-019-09715-w) contains supplementary material, which is available to authorized users.

BACKGROUND Increased complication rate has been reported in Parkinson's disease (PD) patients following total hip arthroplasty (THA). However, this has not previously been studied on a national scale. The purpose of this study was to determine whether PD patients had increased cost, complication, mortality, and length of stay following THA using a national database. METHODS The Healthcare Cost and Utilization Project Nationwide Inpatient Sample was evaluated for the years 2000-2014. PD patients were matched 1:3 with non-PD control patients for age, gender, Charlson Comorbidity Index, and year of admission using a propensity score matching procedure. Univariable and multivariable logistic regression were used to determine the relationship between PD and surgical outcomes in the matched cohort. RESULTS 794,689 THAs were performed from 2000-2014. 4003 patients (0.50%) had comorbid Parkinson's disease. Before matching, arthroplasty patients with PD were significantly older (P < .001), more frequently male (P < .001), and had greater Charlson Comorbidity Index (P < .001). In the matched cohort, PD was associated with increased length of stay (3.1 vs 2.7 days, P < .001), total hospital charges ($49,061 vs $45,571, P < .001), and in-hospital complication rate (14.6% vs 11.7%, P < .001). There was no difference in-hospital mortality (0.50% vs 0.47%, P = .781). CONCLUSIONS Matched cohort analysis demonstrated increases in complication rate, length, and cost of hospitalization for THA in patients with PD. However, in-hospital mortality rate in PD patients was not increased. Of note, the elevation in per-episode cost ($3490) may be of concern when considering PD patients for surgery within the evolving "bundled payment" model of care. LEVEL OF EVIDENCE Prognostic- Level III.

Antimicrobial resistance is one of the most serious threats to medical science. Food supply is recognized as a potential source of resistant bacteria, leading to the development of surveillance programs targeting primarily poultry, pork, and beef. These programs are limited in scope, not only in the commodities tested, but also in the organisms targeted (Escherichia coli, Salmonella, and Campylobacter); consequently, neither the breadth of food products available nor the organisms that may harbour clinically relevant and (or) mobile resistance genes are identified. Furthermore, there is an inadequate understanding of how international trade in food products contributes to the global dissemination of resistance. This is despite the recognized role of international travel in disseminating antimicrobial-resistant organisms, notably New Delhi metallo-beta-lactamase. An increasing number of studies describing antimicrobial-resistant organisms in a variety of imported foods are summarized in this review.

Patients with hip and knee arthritis often undergo bilateral total hip arthroplasty (THA) and total knee arthroplasty (TKA) in a staged or simultaneous fashion. However, when staged, the incidence and factors associated with having both procedures performed by the same surgeon or different surgeon are not well studied.All patients undergoing nonsimultaneous bilateral THA or TKA for osteoarthritis were abstracted from the 2010 to 2020 PearlDiver Mariner administrative database. The National Provider Identifier number was used to determine whether the same surgeon performed both surgeries. Demographics, comorbidities, and 90-day complications after the first joint replacement were assessed as possible independent predictors of utilizing a different surgeon for the contralateral joint.Of 87,593 staged bilateral THAs, the same surgeon performed 40,707 (46.5%) arthroplasties. Of 147,938 staged bilateral TKAs, the same surgeon performed 77,072 (52.1%) arthroplasties. Notably, older cohorts of patients had independent, stepwise, and significantly greater odds of changing surgeons for the contralateral THA and TKA. Those patients who were insured by Medicare and Medicaid had significantly lower odds of changing surgeons. For both THA and TKA, surgical and implant-related adverse events (surgical site infection/periprosthetic joint infection, periprosthetic fracture, dislocation, manipulation) carried the greatest odds of undergoing the contralateral replacement with a different surgeon.Patients covered by Medicaid and sicker patients were significancy less likely to switch surgeons for their contralateral THA or TKA. Additionally, patients experiencing a surgery-related adverse event within 90 days of their first THA or TKA had significantly, increased odds of switching surgeons for their subsequent TJA.

INTRODUCTION As rates of primary total joint arthroplasty continue to rise, so do rates of revision. Revision total hip arthroplasty (THA) and total knee arthroplasty (TKA) are more frequently done at larger centers, are associated with higher morbidity, and may have different patient satisfaction outcomes. This study compares the survey results of Hospital Consumer Assessment of Healthcare Providers and Systems (HCAHPS) between patients who underwent primary versus revision THA or TKA. METHODS All adult patients who underwent inpatient, elective, primary, and revision THA or TKA at a single institution were selected for retrospective analysis. Patient demographics, comorbidities, functional status, surgical variables, 30-day outcomes, and HCAHPS scores were assessed. Univariate and multivariate analyses were done to determine correlations between the aforementioned variables and top-box HCAHPS survey scores for primary versus revision THA and TKA. RESULTS Of 2,707 patients who met the inclusion criteria and had returned the HCAHPS survey, primary THA was documented in 1,075 patients (39.71%), revision THA in 75 (2.77%), primary TKA in 1,497 (55.30%), and revision TKA in 60 (2.22%). Revision THA patients were more functionally dependent, and TKA patients had higher American Society of Anesthesiologists score than their primary comparators. Revisions had longer hospital length of stay for both procedures. For THA, revision THA patients demonstrated lower total top-box rates compared withprimary THA patients (71.64% versus 75.67% top-box, P < 0.001) and lower scores on the care from doctors subsection (76.26% versus 85.34%, P < 0.001) of the HCAHPS survey. Similarly, for TKA, revision TKA patients demonstrated lower total top-box rates (76.13% versus 79.22%, P < 0.013) and lower scores on the care from doctors subsection (66.28% versus 83.65%, P < 0.001) of the HCAHPS survey. DISCUSSION For both THA and TKA, revision procedures were associated with lower total HCAHPS scores and rated care from doctors. This suggests that HCAHPS scores may be biased by factors outside the surgeon's control, such as the complexity associated with revision procedures. LEVEL OF EVIDENCE Level III.

Antimicrobial resistance surveillance targeting agricultural animals is practiced in many countries but does not often include media selective for cephalosporin resistance. Here, we compared the frequency of recovery of resistant Escherichia coli using selective and non-selective media from the cecal contents of 116 chickens collected by the Canadian Integrated Program for Antimicrobial Resistance Surveillance (CIPARS). Third generation cephalosporin resistance was detected in 24 samples including 12, 10, and 2 on selective, non-selective, and both media, respectively. Isolates producing the CTX-M-1 ESBL were grown from 11 samples, 10 on selective medium only. Our results suggest that current surveillance approaches underestimate the true prevalence of resistance to critically important antimicrobials.

No abstract available.