GatewayNet: a form of sequential rule mining

Abstract Background The gateway hypothesis (and particularly the prediction of developmental stages in drug abuse) has been a subject of protracted debate since the 1970s. Extensive research has gone into this subject, but has yielded contradictory findings. We propose an algorithm for detecting both association and causation relationships given a discrete sequence of events, which we believe will be useful in addressing the validity of the gateway hypothesis. To assess the gateway hypothesis, we developed the GatewayNet algorithm, a refinement of sequential rule mining called initiation rule mining. After a brief mathematical definition, we describe how to perform initiation rule mining and how to infer causal relationships from its rules (“gateway rules”). We tested GatewayNet against data for which relationships were known. After constructing a transaction database using a first-order Markov chain, we mined it to produce a gateway network. We then discuss various incarnations of the gateway network. We then evaluated the performance of GatewayNet on urine drug screening data collected from the emergency department at LSU Health Sciences Center in Shreveport. A de-identified database of urine drug screenings ordered by the department between August 1998 and June 2011 was collected and then restricted to patients having at least one screening succeeding their first positive drug screening result. Results In the synthetic data, a chain of gateway rules was found in the network which demonstrated causation. We did not find any evidence of gateway rules in the empirical data, but we were able to isolate two documented transitions into benzodiazepine use. Conclusions We conclude that GatewayNet may show promise not only for substance use data, but other data involving sequences of events. We also express future goals for GatewayNet, including optimizing it for speed

Improved Healthcare Access Reduces Requirements for Surgery in Indigent IBD Patients Using Biologic Therapy: A ‘Safety-Net’ Hospital Experience

Low socioeconomic status (SES) is associated with greater morbidity and increased healthcare resource utilization (HRU) in IBD. We examined whether a financial assistance program (FAP) to improve healthcare access affected outcomes and HRU in a cohort of indigent IBD patients requiring biologics. IBD patients (>18 years) receiving care at a ‘safety-net’ hospital who initiated biologics as outpatients between 1 January 2010 and 1 January 2019 were included. Patients were divided by FAP status. Patients without FAP had Medicare, Medicaid, or commercial insurance. Primary outcomes were steroid-free clinical remission at 6 and 12 months. Secondary outcomes were surgery, hospitalization, and ED utilization. Multivariate logistic regression was used to calculate odds ratio (OR) and 95% confidence interval (CI). Decision tree analysis (DTA) was also performed. We included 204 patients with 258 new biologic prescriptions. FAP patients had less complex Crohn’s disease (50.7% vs. 70%, p = 0.033) than non-FAP patients. FAP records indicated fewer prior surgeries (19.6% vs. 38.4% p = 0.003). There were no statistically significant differences in remission rates, disease duration, or days between prescription and receipt of biologics. In multivariable logistic regression, adjusting for baseline demographics and disease severity variables, FAP patients were less likely to undergo surgery (OR: 0.28, 95% CI [0.08–0.91], p = 0.034). DTA suggests that imaging utilization may shed light on surgical differences. We found FAP enrollment was associated with fewer surgeries in a cohort of indigent IBD patients requiring biologics. Further studies are needed to identify interventions to address healthcare disparities in IBD

Trends in drug use among young adult females: a 22-year retrospective analysis

AbstractLouisiana State University Health Sciences Center at Shreveport (LSUHSC-S) serves a largely minority-based, urban population. This study aims to identify trends in urine drug screen (UDS) results among females aged 18–35 visiting State University during 1998–2011 and 2012–2019. Using two databases extracted from the electronic medical record system, we performed statistical analysis of demographics and UDS results. Young females aged 18–35 mostly tested positive for cannabinoids and opiates during both periods, 1998–2011 and 2012–2019. African-American females had a higher percentage of positive UDS for illicit drugs, such as cannabinoids and cocaine, while Caucasian females had a higher rate for prescription drugs such as opiates, benzodiazepines, and amphetamine. Between 1998–2011 and 2012–2019, trends in drug screen results changed in both populations, with Caucasian females showing a drastic increase in amphetamines and African-American females showing increase in opiates and cannabinoids during 2012–2019. GatewayNet analysis (sequential-rule mining for inducing causation) for 2012–2019 indicated that a positive screen for amphetamines is likely preceded by a positive screen for cannabinoids, and benzodiazepines may be preceded by opiates. Our results emphasize the importance of drug use monitoring among young females of childbearing age. GatewayNet analysis implies a sequential nature to drug positivity on urine drug screening in this population

Trends in Drug Tests among Children: A 22-Year Retrospective Analysis

There are several pathophysiological outcomes associated with substance abuse including metabolic disbalance, neurodegeneration, and disordered redox. Drug use in pregnant women is a topic of great concern due to developmental harm which may occur during gestation and the associated complications in the neonate after delivery. We sought to determine what the trajectory of drug use is like in children aged 0–4 years and mothers of neonates. Urine drug screen (UDS) results were obtained of our target demographic during 1998–2011 and 2012–2019 from LSU Health Sciences Center in Shreveport (LSUHSC-S). Statistical analysis was performed using R software. We observed an increase in cannabinoid-positive UDS results in both Caucasian (CC) and African American (AA) groups between 1998–2011 and 2012–2019 periods. Cocaine-positive UDS results decreased in both cohorts. CC children had higher UDS positive results for opiates, benzodiazepines, and amphetamines, while AA children had a higher percentage for illicit drugs such as cannabinoids and cocaine. Neonate’s mothers had similar UDS trends to that in children during 2012–2019. Overall, while percentage of positive UDS results for both AA and CC 0–4 year old children started to decline for opiate, benzodiazepine, and cocaine during 2012–2019, cannabinoid- and amphetamine (CC)-positive UDS steadily increased. These results suggest a shift in the type of drug use by mothers from opiates, benzodiazepines, and cocaine to cannabinoids and/or amphetamines. We also observed that 18-year-old females who tested positive for opiates, benzodiazepine, or cocaine had higher than average chances of testing positive for cannabinoids later in life

The United States through the Prism of American and British Popular Music

For over a century and in modes ranging from hagiography to protest, popular music has been a prime theatre of observation and representation of the United States on record, in concert and more generally in the performing arts. Studying this field, with its senders — artists and their productions — and its receivers — gatekeepers and audiences — enables us to cast a different light on the USA as a source of inspiration, rejection and attraction for musicians on both sides of the Atlantic in order to explore certain visions of that country, or at least to examine some of the forces that shape and/or distort it. This issue of La Revue LISA/LISA e-journal gives a diversified insight into a field which has not been extensively explored yet, but which does arouse the interest of an increasing number of talented — and mostly young — researchers, as these articles show. As usual, this selection of articles is followed by an essay, under the heading of VARIA, this time about the self-representations of Ireland through stamps and coinage

Risk Stratification in Post-ERCP Pancreatitis: How Do Procedures, Patient Characteristics and Clinical Indicators Influence Outcomes?

Background. Post-endoscopic retrograde cholangiopancreatography (ERCP) pancreatitis (PEP) remains common, and severe complications are associated with ERCP. There is no previous study detailing the effect of race and gender in a US-based population on risk of PEP. Methods. Data were collected on 269 “first-performed” consecutive ERCPs followed by division by race (White vs. African-American) and sex (Female vs. Male). A total of 53 probable risk factors were evaluated by uni- and multivariate analysis followed by outcomes expressed as an odds ratio (OR) (with a 95% confidence interval, 95% CI). Finally, a principal component analysis was performed to construct a risk prediction model for PEP, which can be used by clinicians at bedside. Results. After analyzing the risk factors based on race and gender-based groups, Caucasian males with PEP are more likely to have prior history of pancreatitis (p = 0.009), lower hemoglobin (p = 0.02)/blood urea nitrogen (BUN) (p = 0.01)/creatinine before ERCP (p = 0.07) and lower BUN (p = 0.01)/creatinine after ERCP (p = 0.07), while Caucasian females with PEP are more likely to have higher white blood cell (WBC) count before ERCP (p = 0.08) and lower amylase (p = 0.10)/bilirubin (p = 0.09)/aspartate aminotransferase (AST) after ERCP (p = 0.08). African-American males with PEP are more likely to have lower weight (p = 0.001)/smaller height (p = 0.0005)/lower alkaline phosphatase (p = 0.002)/AST (p = 0.04)/alanine transaminase (ALT) (p = 0.03) before ERCP and lower alkaline phosphatase (p = 0.002)/AST (p = 0.01)/ALT (p = 0.004) after ERCP, while African-American females with PEP are more likely to have prior history of pancreatitis (p = 0.004)/higher lipase before (p = 0.0001) and after (p = 0.05) ERCP along with increased risk with pancreatic duct cannulation (p = 0.0001) and injection (p = 0.0001)/biliary sphincterotomy (p = 0.0001). Importantly, prior history of ERCP, elevated AST after ERCP, and BUN prior to ERCP were found to be important clinical features predicting post-ERCP pancreatitis. To our knowledge, this is a first known attempt at developing a risk scoring system for PEP in a US population with decision tree learning. Conclusions. It is very evident that both patient and procedure-related risk factors vary by race and gender in the US population, leading to the development of a new risk assessment tool for PEP that can be used in clinical practice. We need to follow up with a larger prospective study to validate this novel race and gender-based risk scoring system for PEP

Nickel N-Heterocyclic Carbene Catalysts for Ester Carbonylation

Millions of tons of “acetyls” such as acetic acid and acetic anhydride are produced each year. These basic building blocks of chemical industry are elaborated into esters, amides, and eventually polymer materials, pharmaceuticals, and other consumer products. The vast majority of acetyls are produced industrially using homogeneous catalysis, but exclusively using scarce and expensive precious metal catalysts (principally rhodium and iridium complexes). We report here that nickel catalysts supported by N-heterocyclic carbene ligands mediate the carbonylation of methyl esters, selectively producing anhydrides with high activity at low catalyst loading. Carbene supporting ligands with aryl substituents, which can be added as air-stable imidazolium salts, dramatically improve carbonylation performance relative to prior nickel catalysts supported by tertiary phosphine ligands, raising hopes for industrial application of base metal carbonylation catalysts

Nickel-catalyzed ester carbonylation promoted by imidazole-derived carbenes and salts

Millions of tons of acetyl derivatives such as acetic acid and acetic anhydride are produced each year. These building blocks of chemical industry are elaborated into esters, amides, and eventually polymer materials, pharmaceuticals, and other consumer products. Most acetyls are produced industrially using homogeneous precious metal catalysts, principally rhodium and iridium complexes. We report here that abundant nickel can be paired with imidazole-derived carbenes or the corresponding salts to catalyze methyl ester carbonylation with turnover frequency (TOF) exceeding 150 hour???1 and turnover number (TON) exceeding 1600, benchmarks that invite comparisons to state-of-the-art rhodium-based systems and considerably surpass known triphenylphosphine-based nickel catalysts, which operate with TOF ~7 hour???1 and TON ~100 under the same conditions