What's important in a contract beyond the salary? A primer for pain physicians and trainees.

This manuscript is designed to complement the previously published primer on salary structures for new pain physicians. The previous manuscript "Employment Contract Financial Models for the Pain Physician: A Primer" had a goal of increasing understanding of financial models by pain fellows when preparing for contract negotiations. This manuscript illustrates the many equally important considerations of "non-monetary" values that are a significant part of contract negotiation outside of salary. It contributes to the overall education for trainees and pain physicians on benefits and job responsibilities.

Single-use Duodenoscope: The Cleaner Standard.

Endoscopic retrograde cholangiopancreatography (ERCP) is the gold standard in the endoscopic management of biliary disease. An average of 700,000 ERCPs are performed every year, and most are performed using a reusable flexible duodenoscope. The innovation of disposable duodenoscopes has changed the dynamic in the advanced endoscopy field of study to primarily reduce or eliminate the risk of cross-contamination between patients. Many factors affect whether institutions can convert from standard reusable duodenoscopes to single-use duodenoscopes including the cost of the devices, reimbursement from insurance companies for the new devices, and the overall environmental impact. However, the reduction of cross-contamination leading to active infection in patients, environmental waste produced with high-level disinfection procedures, staff and equipment required for reprocessing, and the inability to frequently upgrade duodenoscopes for optimal performance are all factors that favor transitioning to single-use duodenoscopes. As these devices are new to the field of gastroenterology, the purpose of this review is to analyze the advantages and disadvantages of transitioning to single-use devices and a brief mention of alternative options for institutions unable to make this change.

Identification and Characterization of Synthetic Nicotine Product Promotion and Sales on Instagram Using Natural Language Processing.

INTRODUCTION: There has been a rapid proliferation of synthetic nicotine products in recent years, despite newly established regulatory authority and limited research into its health risks. Previous research has implicated social media platforms as an avenue for nicotine product unregulated sales. Yet, little is known about synthetic nicotine product content on social media. We utilized natural language processing to characterize the sales of synthetic nicotine products on Instagram. METHODS: We collected Instagram posts by querying Instagram hashtags (e.g., "#tobaccofreenicotine) related to synthetic nicotine. Using BERT, collected posts were categorized into thematically related topic clusters. Posts within topic clusters relevant to study aims were then manually annotated for variables related to promotion and selling (e.g., cost discussion, contact information for offline sales). RESULTS: A total of 7,425 unique posts were collected with 2,219 posts identified as related to promotion and selling of synthetic nicotine products. Nicotine pouches (52.9%, n=1174), ENDS (30.6%, n=679), and flavored e-liquids (14.1%, n=313) were most commonly promoted. 16.1% (n=345) of posts contained embedded hyperlinks and 5.8% (n=129) provided contact information for purported offline transactions. Only 17.6% (n=391) of posts contained synthetic nicotine specific health warnings. CONCLUSIONS: In the United States, synthetic nicotine products can only be legally marketed if they have received premarket authorization from the FDA. Despite these prohibitions, Instagram appears to be a hub for potentially unregulated sales of synthetic and "tobacco-free" products. Efforts are needed by platforms and regulators to enhance content moderation and prevent unregulated online sales of existing and emerging synthetic nicotine products. IMPLICATIONS: There is limited clinical understanding of synthetic nicotine's unique health risks and how these novel products are changing over time due to regulatory oversight. Despite synthetic nicotine specific regulatory measures, such as the requirement for premarket authorization and FDA warning letters issued to unauthorized sellers, access to and promotion of synthetic nicotine is widely occurring on Instagram, a platform with over 2 billion users and one that is popular among youth and young adults. Activities include direct-to-consumer sales from questionable sources, inadequate health warning disclosure, and exposure with limited age restrictions, all conditions necessary for the sale of various tobacco products. Notably, the number of these Instagram posts increased in response to the announcement of new FDA regulations. In response, more robust online monitoring, content moderation, and proactive enforcement is needed from platforms who should work collaboratively with regulators to identify, report, and remove content in clear violation of platform policies and federal laws. Regulatory implementation and enforcement should prioritize digital platforms as conduits for unregulated access to synthetic nicotine products and other future novel and emerging tobacco products.

Predictive Partition Dosimetry and Outcomes after Yttrium-90 Resin Microsphere Radioembolization of Colorectal Cancer Metastatic to the Liver: A Retrospective Analysis.

PURPOSE: To characterize estimated absorbed tumor dose (ADT), objective response (OR), and estimated target dose of liver metastatic colorectal cancer (mCRC) after resin microsphere yttrium-90 (90Y) radioembolization using partition dosimetry. MATERIALS AND METHODS: In this retrospective, single-center study, multicompartment dosimetry of index tumors undergoing 90Y radioembolization from October 2013 to July 2022 was performed using MIM SurePlan and pretreatment technetium-99m macroaggregated albumin infusion data. Thirty-eight patients with mCRC underwent treatments for 59 index tumors. Patients were imaged every 2-3 months after treatment and then every 3-6 months after disease control to determine the best response per Response Evaluation Criteria in Solid Tumors 1.1. Responses were categorized as OR or nonresponse (NR). A Cox proportional hazards model evaluated the probability of tumor OR and local progression-free survival (LPFS) based on ADT. RESULTS: Patients had a median follow-up of 116 days (interquartile range [IQR], 69-231 days). The ADT was higher for OR patients than for NR patients (median, 130.8 [IQR, 85.6-239.0] vs 40.6 [IQR, 26.0-66.3] Gy; P < .001). A greater percentage of OR than NR patients were treated with activities calculated by partition modeling (54% vs 12%; P = .005). Only ADT predicted response (P = .032). At 6 months, an ADT of 120 Gy predicted a 55% (95% CI, 0.0%-89%) probability of OR. Only ADT (P = .010) and female sex (P = .014) predicted LPFS. At 1 year, an ADT of 120 Gy predicted a 70% (95% CI, 35%-100%) probability of LPFS. CONCLUSIONS: Tumor dose was the strongest predictor of OR for mCRC. Administration of an estimated 120 Gy to mCRC predicted 55% OR with 90Y resin microspheres at 6 months.

Spontaneous Coronary Artery Dissection (SCAD) in an Atypical Patient Without Risk Factors and Prior Asymptomatic COVID-19 Infection.

Spontaneous coronary artery dissection (SCAD) is a condition primarily seen in young women and is characterized by non-atherosclerotic arterial damage. It can occur with or without conventional risk factors for coronary heart disease and is often associated with chronic inflammatory conditions. Here, we present a unique instance of a 67-year-old woman without known risk factors who developed sudden onset chest pain in the setting of an asymptomatic coronavirus 2019 (COVID-19) infection three weeks earlier. Subsequent evaluation revealed SCAD in the distal left anterior descending (LAD) artery.

Prevalence and outcomes of heparin-induced thrombocytopenia in hospitalized patients with venous thromboembolic disease: Insight from national inpatient sample.

OBJECTIVE: The mainstay of therapy for patients with venous thromboembolic disease (VTE) is anticoagulation. In the inpatient setting, majority of these patients are treated with heparin or low molecular weight heparin. The prevalence and outcomes of heparin-induced thrombocytopenia (HIT) in hospitalized patients with venous thromboembolic disease (VTE) is unknown. METHODS: This nationwide study identified patients with VTE from the National Inpatient Sample database between January 2009 and December 2013. Among these patients, we compared in-hospital outcomes of patients with and without HIT using a propensity score-matching algorithm. The primary outcome was in-hospital mortality. Secondary outcomes included rates of blood transfusions, intracranial hemorrhage, gastrointestinal bleed, length of hospital stay, and total hospital charges. RESULTS: Among 791,932 hospitalized patients with VTE, 4948 patients (0.6%) were noted to have HIT (mean age, 62.9 ±16.2 years; 50.1% female). Propensity-matched comparison showed higher rates of in-hospital mortality (11.01% vs 8.97%; P < .001) and blood transfusions (27.20% vs 20.23%; P < .001) in patients with HIT compared with those without HIT. No significant differences were noted in intracranial hemorrhage rates (0.71% vs 0.51%; P > .05), gastrointestinal bleed (2.00% vs 2.22%; P > .05), length of hospital stay (median, 6.0 days; interquartile range [IQR], 3.0-11.0 vs median, 6.0 days; IQR, 3.0-10.0 days; P > .05), and total hospital charges (median, $36,325; IQR, $17,798-$80,907 vs median, $34,808; IQR, $17,654-$75,624; P > .05). CONCLUSIONS: This nationwide observational study showed that 0.6% of hospitalized patients with VTE in the United States have HIT. The presence of HIT was associated with higher in-hospital mortality and blood transfusion rates compared with those without HIT.

Donor HLA mismatch promotes full donor T-cell chimerism in the allogeneic stem cell transplant with reduced-intensity conditioning and post-transplant cyclophosphamide GVHD prophylaxis.

Full donor T-cell chimerism (FDTCC) after allogeneic stem cell transplant (allo-SCT) has been associated with improved outcomes in hematologic malignancy. We studied if donor human leukocyte antigen (HLA) mismatch improves achievement of FDTCC because mismatched HLA promotes donor T-cell proliferation where recipient T-cells had been impaired by previous treatment. Patients (N = 138) received allo-SCT with reduced-intensity conditioning (RIC) from 39 HLA mismatched donors (16 unrelated; 23 haploidentical) with post-transplant cyclophosphamide (PTCy) or 99 matched donors (21 siblings; 78 unrelated) with PTCy (N = 18) or non-PTCy (N = 81). Achievement of FDTCC by day 100 was higher with HLA mismatched donors than matched donors (82.1% vs. 27.3%, p < 00,001), which was further improved with 200 cGy total body irradiation (87.9%) or lymphoid (versus myeloid) malignancy (93.8%). Since all mismatched transplants used PTCy, FDTCC was higher with PTCy than non-PTCy (68.4% vs. 25.7%, p < 0.00001), but not in the matched transplant with PTCy (38.9%), negating PTCy as the primary driver. Lymphocyte recovery was delayed with PTCy than without (median on day + 30: 100 vs. 630/µL, p < 0.0001). The benefit of FDTCC was not translated into survival outcomes, especially in myeloid malignancies, possibly due to the insufficient graft-versus-tumor effects from the delayed lymphocyte recovery. Further studies are necessary to improve lymphocyte count recovery in PTCy transplants.

A Glass Ceiling in Orthopedic Surgery: Publication Trends by Gender.

Women are underrepresented across the field of orthopedic surgery and may face barriers to academic advancement. Research presentation at national meetings and publication record are important drivers of advancement in academic orthopedic surgery. However, little is known regarding potential gender differences in publication after orthopedic conference research presentation. This investigation analyzed research presentations at the Annual Meeting of the American Academy of Orthopaedic Surgeons in 2016 and 2017. Author gender was determined through a search of institutional and professional networking websites for gender-specific pronouns. Resulting publications were identified using a systematic search of PubMed and Google Scholar databases. A total of 1696 of 1803 (94.1%) abstracts from 2016 to 2017 had identifiable gender for both the first and last authors, with 1213 (71.5%) abstracts ultimately being published. There were no differences in average sample size or level of evidence between genders. Abstracts authored by women were significantly less likely to lead to publication compared with those by men (67.1% vs 72.1%, P=.023), with articles authored by women having a longer median time to publication (median, 20 months [interquartile range, 19] vs 17 months [interquartile range, 15]; P=.003). This discrepancy was most apparent in adult reconstruction, with women having a 15.5% lower rate of publication (55.1% [27/49] vs 70.6% [307/435]; P=.026) and lower publication journal impact factor (2.7±1.4 vs 3.4±3.4, P=.040) than men. Potential reasons for these discrepancies, including disproportionate domestic obligations, inadequate mentorship, and bias against female researchers, should be addressed. [Orthopedics. 2023;46(2):e118-e124.].

Applying topic modelling and qualitative content analysis to identify and characterise ENDS product promotion and sales on Instagram.

BACKGROUND: Increased public health and regulatory scrutiny concerning the youth vaping epidemic has led to greater attention to promotion and sales of vaping products on social media platforms. OBJECTIVES: We used unsupervised machine learning to identify and characterise sale offers of electronic nicotine delivery systems (ENDS) and associated products on Instagram. We examined types of sellers, geographic ENDS location and use of age verification. METHODS: Our methodology was composed of three phases: data collection, topic modelling and content analysis. We used data mining approaches to query hashtags related to ENDS product use among young adults to collect Instagram posts. For topic modelling, we applied an unsupervised machine learning approach to thematically categorise and identify topic clusters associated with selling activity. Content analysis was then used to characterise offers for sale of ENDS products. RESULTS: From 70 725 posts, we identified 3331 engaged in sale of ENDS products. Posts originated from 20 different countries and were roughly split between individual (46.3%) and retail sellers (43.4%), with linked online sellers (8.8%) representing a smaller volume. ENDS products most frequently offered for sale were flavoured e-liquids (53.0%) and vaping devices (20.5%). Online sellers offering flavoured e-liquids were less likely to use age verification at point of purchase (29% vs 64%) compared with other products. CONCLUSIONS: Instagram is a global venue for unregulated ENDS sales, including flavoured products, and access to websites lacking age verification. Such posts may violate Instagram's policies and US federal and state law, necessitating more robust review and enforcement to prevent ENDS uptake and access.

Intestinal Microbiota in Experimental Acute Kidney Injury.

Recent studies have demonstrated an important role played by gut microbiota in maintaining intestinal homeostasis and host immune system function. Gut microbiota have been studied in experimental acute kidney injury (AKI) using different mice and rat models exposed to either ischemia or cisplatin-mediated tubular injury. Differences in inflammatory markers and severity of AKI have been observed between germ-free mice, wild-type mice, and mice treated with antibiotics or specific bacteria. Interventions modifying the gut microbiota after experimental AKI have had either beneficial or harmful effects on kidney tubular injury and recovery. These findings provide strong evidence for a modulatory role of gut microbiota during AKI. Ischemic and cis-platin-induced AKI have distinct stool microbial signatures based on 16s sequencing. Future in-depth studies exploring the mechanisms of how the microbiota influence AKI and development of feasible therapeutic options have the potential to improve outcomes in clinical AKI.

Technical Report: Protocol for Characterizing Phenotype Variants Using Phenome-Wide Association Study (PheWAS) Utilizing the Nationwide Inpatient Sample 2020 in Individuals With Pancreatic Cysts and Lung Cancer.

This technical report serves as a comprehensive guide for conducting a phenome-wide association study (PheWAS) utilizing data extracted from the Nationwide Inpatient Sample 2020. Specifically tailored to individuals diagnosed with pancreatic cysts and lung cancer, the report establishes a step-by-step workflow designed to assist researchers in uncovering potential associations within this specific cohort. The methodology outlined in the report ensures clarity and reproducibility by employing a curated cohort sourced from the GitHub repository and executed using R for robust data analysis. The code encompasses pivotal steps, including the utilization of a QQ plot as a crucial diagnostic tool aimed at identifying systematic biases or associations. Additionally, the report incorporates the creation of a Manhattan plot, delving into essential mathematical considerations to enhance the interpretability of the results. Notably, the report elucidates the handling of the International Classification of Disease version 10 (ICD-10) codes, providing a sample approach for their segmentation to analyze associations by diagnostic categories. The segmentation aligns with the guidelines outlined in the American Medical Association's ICD-10-CM 2022, the Complete Official Codebook with Guidelines (American Medical Association Press, 2021), ensuring a standardized and rigorous analytical process. This comprehensive guide equips researchers with the tools and insights needed to navigate the complexities of PheWAS within the context of pancreatic cysts and lung cancer, fostering transparency, reproducibility, and meaningful scientific exploration.

Publication Rates Vary Across Orthopaedic Subspecialties: A Longitudinal Analysis of AAOS Abstracts.

Background: Presentation of research at national orthopaedic meetings and subsequent publication are important for both information exchange among surgeons and individual academic advancement. However, the academic landscape and pressures that researchers face may differ greatly across different subspecialties. This study attempts to explore and quantify differences in research presented at national conferences and its implication on ultimate likelihood of publication in peer-reviewed journals. Methods: All abstracts from the Annual Meetings of the American Academy of Orthopaedic Surgeons (AAOS) from 2016 and 2017 were reviewed and categorized based on subspecialty focus. Resulting publications were identified using a systematic search of PubMed and Google Scholar databases. Multivariate binary logistic regression modelling was used to assess the predictive value of abstract characteristics on eventual publication. Results: A total of 1805 abstracts from the 2016 and 2017 AAOS conferences were reviewed. The overall publication rate of abstracts following the AAOS meetings was 71.6%, with an average time to publication from abstract submission deadline and impact factor of 19.8 months and 2.878, respectively. Statistical differences were observed across subspecialties with respect to publication rate (p<0.001), time to publication (p<0.001), and impact factor (p<0.001). The subspecialty with the highest publication rate, largest impact factor, and shortest average time to publication was Sports Medicine with 83.2%, 3.98, and 17.6 months, respectively; despite lower average sample size (p<0.001) and frequency of multicenter design (p<0.001) compared with other subspecialties. The subspecialty with the lowest publication rate and impact factor was Hand and Wrist with 53.3% and 1.41, respectively. Multivariate logistic regression analysis demonstrates a lower likelihood for internationally authored abstracts (OR: 0.75, p=0.021) and higher likelihood for basic science abstracts (OR: 1.52, p-value=0.023) to reach publication. Conclusion: Differences in publication rate across orthopaedic subspecialties were observed with articles in sports medicine more likely to be published, published quickly, and featured in a higher impact factor journals. Understanding these differences, and how they relate to the publication and promotion of novel research, is important for orthopaedic researchers. Level of Evidence: IV.

How Much Will My Child's ACL Reconstruction Cost? Availability and Variability of Price Estimates for Anterior Cruciate Ligament Reconstruction in the United States.

BACKGROUND: Despite recent policy efforts to increase price transparency, obtaining estimated prices for surgery remains difficult for most patients and families. PURPOSE: Assess availability and variability of cost and self-pay discounts for pediatric anterior cruciate ligament (ACL) reconstruction in the United States. METHODS: This was a prospective study using scripted telephone calls to obtain price estimates and self-pay discounts for pediatric ACL reconstruction. From July to August 2020, investigators called 102 hospitals, 51 "top-ranked" pediatric orthopaedic hospitals and 51 "non-top ranked" hospitals randomly selected, to impersonate the parent of an uninsured child with a torn ACL. Hospital, surgeon, and anesthesia price estimates, availability of a self-pay discount, and number of calls and days required to obtain price estimates were recorded for each hospital. Hospitals were compared on the basis of ranking, teaching status, and region. RESULTS: Only 31/102 (30.3%) hospitals provided a complete price estimate. Overall, 52.9% of top-ranked hospitals were unable to provide any price information versus 31.4% of non-top-ranked hospitals ( P =0.027). There was a 6.1-fold difference between the lowest and highest complete price estimates (mean estimate $29,590, SD $14,975). The mean complete price estimate for top-ranked hospitals was higher than for non-top-ranked hospitals ($34,901 vs. $25,207; P =0.07). The mean complete price estimate varied significantly across US region ( P =0.014), with the greatest mean complete price in the Northeast ($41,812). Altogether, 38.2% hospitals specified a self-pay discount, but only a fraction disclosed exact dollar or percentage discounts. The mean self-pay discount from top-ranked hospitals was larger than that of non-top-ranked hospitals ($18,305 vs. $9902; P =0.011). An average of 3.1 calls (range 1.0 to 12.0) over 5 days (range 1 to 23) were needed to obtain price estimates. CONCLUSION: Price estimates for pediatric sports medicine procedures can be challenging to obtain, even for the educated consumer. Top-ranked hospitals and hospitals in the Northeast region may charge more than their counterparts. In all areas, self-pay discounts can be substantial if they can be identified but they potentially create an information disadvantage for unaware patients needing to pay out-of-pocket. STUDY DESIGN: Economic; Level of Evidence II. WHAT IS KNOWN ABOUT THE SUBJECT: Previous studies have highlighted the importance of value-based health care decisions and deficits of price transparency in various fields including pediatric and orthopaedics procedures. WHAT THIS STUDY ADDS TO EXISTING KNOWLEDGE: This study is the first to examine availability and variability of health care cost in pediatric sports medicine and the first to assess availability and magnitude of self-pay discounts, setting expectations for the uninsured patient incurring large out-of-pocket expenses.

Trends in 10-Year Predicted Risk of Cardiovascular Disease Associated With Food Insecurity, 2007-2016.

Introduction: Consumption of a healthy diet improves cardiovascular (CV) risk factors and reduces the development of cardiovascular disease (CVD). Food insecure (FIS) adults often consume an unhealthy diet, which can promote obesity, type 2 diabetes mellitus (T2DM), hypertension (HTN), and hyperlipidemia (HLD). The Supplemental Nutrition Assistance Program (SNAP) is designed to combat food insecurity by increasing access to healthy foods. However, there is a paucity of data on the association of SNAP participation among FIS adults and these CVD risk factors. Methods: The National Health and Nutrition Examination Survey (NHANES) is a publicly available, ongoing survey administered by the Centers for Disease Control and Prevention and the National Center for Health Statistics. We analyzed five survey cycles (2007-2016) of adult participants who responded to the CVD risk profile questionnaire data. We estimated the burden of select CVD risk factors among the FIS population and the association with participation in SNAP. Results: Among 10,449 adult participants of the survey, 3,485 (33.3%) identified themselves as FIS. Food insecurity was more common among those who were younger, female, Hispanic, and Black. Among the FIS, SNAP recipients, when compared to non-SNAP recipients, had a lower prevalence of HLD (36.3 vs. 40.1% p = 0.02), whereas rates of T2DM, HTN, and obesity were similar. Over the 10-year survey period, FIS SNAP recipients demonstrated a reduction in the prevalence of HTN (p < 0.001) and HLD (p < 0.001) which was not evident among those not receiving SNAP. However, obesity decreased only among those not receiving SNAP. The prevalence of T2DM did not change over the study period in either group. Conclusion: Over a 10-year period, FIS adults who received SNAP demonstrated a reduction in the prevalence of HTN and HLD, which was not seen among those not receiving SNAP. However, the prevalence of obesity and T2DM did not decline among SNAP recipients, suggesting that additional approaches are required to impact these important CVD risk factors.

Post-transplant cyclophosphamide alters immune signatures and leads to impaired T cell reconstitution in allogeneic hematopoietic stem cell transplant.

Despite the increased usage of post-transplant cyclophosphamide (PTCy) in allogeneic hematopoietic stem cell transplantation (allo-HSCT), our knowledge of immune reconstitution post-allo-HSCT in the setting of PTCy is limited. Adequate immune reconstitution is the key to a successful transplant. In this study, we aim to investigate the effect of PTCy on the reconstitution of each immune component; more focus was placed on the immunophenotype and functions of T cells. Using blood samples from patients who underwent allo-HSCT under regimens containing PTCy (n = 23) versus those who received no PTCy (n = 14), we examined the impact of PTCy on the post-transplant immune response. We demonstrated a distinct T cell immune signature between PTCy versus non-PTCy group. PTCy significantly delayed T cell reconstitution and affected the T cell subsets by increasing regulatory T cells (Treg) while reducing naïve T cells. In addition, we observed remarkable enhancement of multiple inhibitory receptors (TIGIT, PD-1, TIM-3, CD38, CD39) on both CD4+ and CD8+ T cells on day 30 post-transplantation in patients who received PTCy. Importantly, upregulation of PD-1 on CD8 T cells was persistent through day 180 and these T cells were less functional, manifested by reduced cytokine production upon anti-CD3/CD28 stimulation. Furthermore, we found a significant correlation of T cell immune phenotypes to clinical outcome (disease relapse and GVHD) in patients who received PTCy. Our novel findings provide critical information to understand the mechanism of how PTCy impacts immune reconstitution in allo-HSCT and may subsequently lead to optimization of our clinical practice using this treatment.

Toxic and metabolic leukoencephalopathies in emergency department patients: a primer for the radiologist.

One of the most common chief complaints in the emergency department (ED) is altered mental status (AMS). Imaging plays a critical role in triaging patients and identifying the etiology of AMS. Toxic and metabolic etiologies are one of the primary differential categories for AMS, leading to toxic leukoencephalopathies. Toxic leukoencephalopathies are white matter disorders that result from either exogenous or endogenous sources. Common exogeneous causes of toxic leukoencephalopathy include drugs of abuse (heroin and cocaine), alcohol, inhaled gases (carbon monoxide), industrial agents (pesticides, toluene, ethylene glycol), and neurotoxic medications (methotrexate, metronidazole, vigabatrine, etc.); endogenous causes include hyper- and hypoglycemia, hyperammonemia, hyponatremia, and uremia. The imaging findings of toxic leukoencephalopathies manifest through a combination of vasogenic and cytotoxic edema, resulting in white matter patterns. These white matter patterns have been found to be pathognomonic. In the ED setting, it is imperative to develop a diagnosis based off of the imaging due to the lack of history and context that is typically provided with a chief complaint of altered mental status (AMS). To offer expeditious and accurate diagnosis, we present the classic imaging features of toxic leukoencephalopathies and correlate these imaging findings with pathophysiology.

An unsupervised machine learning approach for the detection and characterization of illicit drug-dealing comments and interactions on Instagram.

Background: Growing use of social media has led to the emergence of virtual controlled substance and illicit drug marketplaces, prompting calls for action by government and law enforcement. Previous studies have analyzed Instagram drug selling via posts. However, comments made by users involving potential drug selling have not been analyzed. In this study, we use unsupervised machine learning to detect and classify prescription and illicit drug-related buying and selling interactions on Instagram. Methods: We used over 1,000 drug-related hashtags on Instagram to collect a total of 43,607 Instagram comments between February 1st, 2019 and May 31st, 2019 using data mining approaches in the Python programming language. We then used an unsupervised machine learning approach, the Biterm Topic Model (BTM), to thematically summarize Instagram comments into distinct topic groupings, which were then extracted and manually annotated to detect buying and selling comments. Results: We detected 5,589 comments from sellers, prospective buyers, and online pharmacies from 531 unique posts. The vast majority (99.7%) of comments originated from drug sellers and online pharmacies. Key themes from comments included providing contact information through encrypted third-party messaging platforms, drug availability, and price inquiry. Commonly offered drugs for sale included scheduled controlled substances such as Adderall and Xanax, as well as illicit hallucinogens and stimulants. Comments from prospective buyers of drugs most commonly included inquiries about price and availability. Conclusions: We detected prescription controlled substances and other illicit drug selling interactions via Instagram comments to posts. We observed that comments were primarily used by sellers offering drugs, and typically not by prospective buyers interacting with sellers. Further research is needed to characterize these "social" drug marketplace interactions on this and other popular social media platforms.