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"Powell, Gregory"
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Social Media Listening for Routine Post-Marketing Safety Surveillance
by
Burstein, Phil J.
,
Reblin, Tjark
,
Powell, Gregory E.
in
Collaboration
,
Drug Safety and Pharmacovigilance
,
Drug use
2016
Introduction
Post-marketing safety surveillance primarily relies on data from spontaneous adverse event reports, medical literature, and observational databases. Limitations of these data sources include potential under-reporting, lack of geographic diversity, and time lag between event occurrence and discovery. There is growing interest in exploring the use of social media (‘social listening’) to supplement established approaches for pharmacovigilance. Although social listening is commonly used for commercial purposes, there are only anecdotal reports of its use in pharmacovigilance. Health information posted online by patients is often publicly available, representing an untapped source of post-marketing safety data that could supplement data from existing sources.
Objectives
The objective of this paper is to describe one methodology that could help unlock the potential of social media for safety surveillance.
Methods
A third-party vendor acquired 24 months of publicly available Facebook and Twitter data, then processed the data by standardizing drug names and vernacular symptoms, removing duplicates and noise, masking personally identifiable information, and adding supplemental data to facilitate the review process. The resulting dataset was analyzed for safety and benefit information.
Results
In Twitter, a total of 6,441,679 Medical Dictionary for Regulatory Activities (MedDRA
®
) Preferred Terms (PTs) representing 702 individual PTs were discussed in the same post as a drug compared with 15,650,108 total PTs representing 946 individual PTs in Facebook. Further analysis revealed that 26 % of posts also contained benefit information.
Conclusion
Social media listening is an important tool to augment post-marketing safety surveillance. Much work remains to determine best practices for using this rapidly evolving data source.
Journal Article
Environmental enrichment during forced abstinence from cocaine self-administration opposes gene network expression changes associated with the incubation effect
by
Powell, Gregory L.
,
Perrone-Bizzozero, Nora I.
,
Bastle, Ryan M.
in
631/378/1595/1396
,
631/378/1689/5
,
631/378/1788
2020
Environmental enrichment (EE) is a robust intervention for reducing cocaine-seeking behaviors in animals when given during forced abstinence. However, the mechanisms that underlie these effects are not well-established. We investigated the adult male rat transcriptome using RNA-sequencing (RNA-seq) following differential housing during forced abstinence from cocaine self-administration for either 1 or 21 days. Enriched, 21-day forced abstinence rats displayed a significant reduction in cocaine-seeking behavior compared to rats housed in isolation. RNA-seq of the nucleus accumbens shell revealed hundreds of differentially regulated transcripts between rats of different forced abstinence length and housing environment, as well as within specific contrasts such as enrichment (isolated 21 days vs. enriched 21 days) or incubation (isolated 1 day vs. isolated 21 days). Ingenuity Pathway Analysis affirmed several pathways as differentially enriched based on housing condition and forced abstinence length including
RELN
, the
Eif2
signaling pathway, synaptogenesis and neurogenesis pathways. Numerous pathways showed upregulation with incubation, but downregulation with EE, suggesting that EE may prevent or reverse changes in gene expression associated with protracted forced abstinence. The findings reveal novel candidate mechanisms involved in the protective effects of EE against cocaine seeking, which may inform efforts to develop pharmacological and gene therapies for treating cocaine use disorders. Furthermore, the finding that EE opposes multiple pathway changes associated with incubation of cocaine seeking strongly supports EE as a therapeutic intervention and suggests EE is capable of preventing or reversing the widespread dysregulation of signaling pathways that occurs during cocaine forced abstinence.
Journal Article
Effects of nicotine self-administration on incentive salience in male Sprague Dawley rats
by
Powell, Gregory L.
,
Daniels, Carter W.
,
Overby, Paula F.
in
Addiction
,
Animals
,
Biomedical and Life Sciences
2018
Rationale
Prolonged use of nicotine appears to enhance incentive salience, a motivational-cognitive process that transforms an otherwise neutral stimulus into a “wanted” stimulus. It has been suggested that nicotinic enhancement of incentive salience contributes to the potential of relapse in individuals with tobacco addiction. However, there are two main limitations of prior research that caution this claim: (a) the use of passive experimentally delivered nicotine and (b) the use of sign-tracking as an index of incentive salience, without acknowledging the competing nature of goal- and sign-tracking responses.
Objectives
To determine whether nicotinic enhancement of incentive salience attributed to non-nicotinic stimuli occurs when rats self-administer nicotine, and whether it is facilitated by a prior history of nicotine self-administration.
Methods
Twenty-three male rats were trained daily, for 24 days, on a nicotine self-administration (SA) paradigm in the morning, and on a four-conditioned-stimuli Pavlovian conditioned approach (4-CS PCA) task in the afternoon. Self-administration was followed by extinction and cue reinstatement. A subcutaneous nicotine challenge was performed during the last 7 days of the study.
Results
Nicotine self-administration selectively enhanced sign-tracking in the 4-CS PCA. Upon extinction, sign-tracking quickly declined to control levels. Experimenter-administered nicotine enhanced sign-tracking similarly regardless of nicotine history.
Conclusions
The results suggest that nicotinic enhancement of incentive salience is transient, and a previous history of nicotine use does not cause further sensitization. Taken together, these results suggest that nicotine enhances incentive salience, particularly—and perhaps exclusively—while onboard.
Journal Article
The Long-Acting D3 Partial Agonist MC-25-41 Attenuates Motivation for Cocaine in Sprague-Dawley Rats
2020
The dopamine D3 receptor is a prime target for developing treatments for cocaine use disorders (CUDs). In this study, we conducted a pre-clinical investigation of the therapeutic potential of a long-acting, D3 receptor partial agonist, MC-25-41. Male rats were pre-treated with MC-25-41 (vehicle, 1.0, 3.0, 5.6, or 10 mg/kg, intraperitoneal (IP)) five minutes prior to tests of cocaine or sucrose intake on either a progressive ratio schedule of reinforcement or a variable interval 60 s multiple schedule consisting of 4, 15-min components with sucrose or cocaine available in alternating components. A separate cohort of rats was tested on a within-session, dose-reduction procedure to determine the effects of MC-25-41 on demand for cocaine using a behavioral economics analysis. Finally, rats were tested for effects of MC-25-41 on spontaneous and cocaine-induced locomotion. MC-25-41 failed to alter locomotion, but reduced reinforcement rates for both cocaine and sucrose on the low-effort, multiple schedule. However, on the higher-effort, progressive ratio schedule of cocaine reinforcement, MC-25-41 reduced infusions, and active lever presses at doses that did not alter sucrose intake. The behavioral economics analysis showed that MC-25-41 also increased cocaine demand elasticity compared to vehicle, indicating a reduction in consumption as price increases. Together, these results suggest that similar to other D3-selective antagonists and partial agonists, MC-25-41 reduces motivation for cocaine under conditions of high cost but has the added advantage of a long half-life (>10 h). These findings suggest that MC-25-41 may be a suitable pre-clinical lead compound for development of medications to treat CUDs.
Journal Article
HuD Regulates mRNA-circRNA-miRNA Networks in the Mouse Striatum Linked to Neuronal Development and Drug Addiction
by
Elyaderani, Amir
,
Perrone-Bizzozero, Nora I.
,
Liang, Winnie S.
in
Addictions
,
Arrays
,
Binding sites
2021
The RNA-binding protein HuD (a.k.a., ELAVL4) is involved in neuronal development and synaptic plasticity mechanisms, including addiction-related processes such as cocaine conditioned-place preference (CPP) and food reward. The most studied function of this protein is mRNA stabilization; however, we have recently shown that HuD also regulates the levels of circular RNAs (circRNAs) in neurons. To examine the role of HuD in the control of coding and non-coding RNA networks associated with substance use, we identified sets of differentially expressed mRNAs, circRNAs and miRNAs in the striatum of HuD knockout (KO) mice. Our findings indicate that significantly downregulated mRNAs are enriched in biological pathways related to cell morphology and behavior. Furthermore, deletion of HuD altered the levels of 15 miRNAs associated with drug seeking. Using these sets of data, we predicted that a large number of upregulated miRNAs form competing endogenous RNA (ceRNA) networks with circRNAs and mRNAs associated with the neuronal development and synaptic plasticity proteins LSAMP and MARK3. Additionally, several downregulated miRNAs form ceRNA networks with mRNAs and circRNAs from MEF2D, PIK3R3, PTRPM and other neuronal proteins. Together, our results indicate that HuD regulates ceRNA networks controlling the levels of mRNAs associated with neuronal differentiation and synaptic physiology.
Journal Article
Identifying Barriers to Enrollment in Patient Pregnancy Registries: Building Evidence Through Crowdsourcing
by
Pimenta, Jeanne M
,
Meizlik, Paige
,
Powell, Marcy
in
Crowdsourcing
,
Demographics
,
Family physicians
2022
Enrollment in pregnancy registries is challenging despite substantial awareness-raising activities, generally resulting in low recruitment owing to limited safety data. Understanding patient and physician awareness of and attitudes toward pregnancy registries is needed to facilitate enrollment. Crowdsourcing, in which services, ideas, or content are obtained by soliciting contributions from a large group of people using web-based platforms, has shown promise for improving patient engagement and obtaining patient insights.
This study aimed to use web-based crowdsourcing platforms to evaluate Belimumab Pregnancy Registry (BPR) awareness among patients and physicians and to identify potential barriers to pregnancy registry enrollment with the BPR as a case study.
We conducted 2 surveys using separate web-based crowdsourcing platforms: Amazon Mechanical Turk (a 14-question patient survey) and Sermo RealTime (a 11-question rheumatologist survey). Eligible patients were women, aged 18-55 years; diagnosed with systemic lupus erythematosus (SLE); and pregnant, recently pregnant (within 2 years), or planning pregnancy. Eligible rheumatologists had prescribed belimumab and treated pregnant women. Responses were descriptively analyzed.
Of 151 patient respondents over a 3-month period (n=88, 58.3% aged 26-35 years; n=149, 98.7% with mild or moderate SLE; and n=148, 98% from the United States), 51% (77/151) were currently or recently pregnant. Overall, 169 rheumatologists completed the survey within 48 hours, and 59.2% (100/169) were based in the United States. Belimumab exposure was reported by 41.7% (63/151) patients, whereas 51.7% (75/145) rheumatologists had prescribed belimumab to <5 patients, 25.5% (37/145) had prescribed to 5-10 patients, and 22.8% (33/145) had prescribed to >10 patients who were pregnant or trying to conceive. Of the patients exposed to belimumab, 51% (32/63) were BPR-aware, and 45.5% (77/169) of the rheumatologists were BPR-aware. Overall, 60% (38/63) of patients reported belimumab discontinuation because of pregnancy or planned pregnancy. Among the 77 BPR-aware rheumatologists, 70 (91%) referred patients to the registry. Concerns among rheumatologists who did not prescribe belimumab during pregnancy included unknown pregnancy safety profile (119/169, 70.4%), and 61.5% (104/169) reported their patients' concerns about the unknown pregnancy safety profile. Belimumab exposure during or recently after pregnancy or while trying to conceive was reported in patients with mild (6/64, 9%), moderate (22/85, 26%), or severe (1/2, 50%) SLE. Rheumatologists more commonly recommended belimumab for moderate (84/169, 49.7%) and severe (123/169, 72.8%) SLE than for mild SLE (36/169, 21.3%) for patients trying to conceive recently or currently pregnant. Overall, 81.6% (138/169) of the rheumatologists suggested a belimumab washout period before pregnancy of 0-30 days (44/138, 31.9%), 30-60 days (64/138, 46.4%), or >60 days (30/138, 21.7%).
In this case, crowdsourcing efficiently obtained patient and rheumatologist input, with some patients with SLE continuing to use belimumab during or while planning a pregnancy. There was moderate awareness of the BPR among patients and physicians.
Journal Article
Enabling social listening for cardiac safety monitoring: Proceedings from a drug information association–cardiac safety research consortium cosponsored think tank
by
Terkowitz, Jeffrey
,
Seifert, Harry A.
,
Okun, Sally
in
Biomedical Research
,
Cardiovascular Agents - therapeutic use
,
Cardiovascular Diseases - drug therapy
2017
This white paper provides a summary of the presentations and discussions from a think tank on “Enabling Social Listening for Cardiac Safety Monitoring” trials that was cosponsored by the Drug Information Association and the Cardiac Safety Research Consortium, and held at the White Oak headquarters of the US Food and Drug Administration on June 3, 2016. The meeting's goals were to explore current methods of collecting and evaluating social listening data and to consider their applicability to cardiac safety surveillance. Social listening is defined as the act of monitoring public postings on the Internet. It has several theoretical advantages for drug and device safety. First, these include the ability to detect adverse events that are “missed” by traditional sources and the ability to detect adverse events sooner than would be allowed by traditional sources, both by affording near–real-time access to data from culturally and geographically diverse sources. Social listening can also potentially introduce a novel patient voice into the conversation about drug safety, which could uniquely augment understanding of real-world medication use obtained from more traditional methodologies. Finally, it can allow for access to information about drug misuse and diversion. To date, the latter 2 of these have been realized.
Although regulators from the Food and Drug Administration and the United Kingdom's Medicines and Healthcare Products Regulatory Agency participated in the think tank along with representatives from industry, academia, and patient groups, this article should not be construed to constitute regulatory guidance.
Journal Article
Chronic treatment with N‐acetylcysteine decreases extinction responding and reduces cue‐induced nicotine‐seeking
by
Schwartz, Danielle
,
Del Franco, Armani P.
,
Spencer, Sade
in
Acetylcysteine
,
Acetylcysteine - pharmacology
,
Addictions
2019
N‐acetylcysteine (NAC), a promising glutamatergic therapeutic agent, has shown some clinical efficacy in reducing nicotine use in humans and has been shown to reverse drug‐induced changes in glutamatergic neurophysiology. In rats, nicotine‐seeking behavior is associated with alterations in glutamatergic plasticity within the nucleus accumbens core (NAcore). Specifically, cue‐induced nicotine‐seeking is associated with rapid, transient synaptic plasticity (t‐SP) in glutamatergic synapses on NAcore medium spiny neurons. The goal of the present study was to determine if NAC reduces nicotine‐seeking behavior and reverses reinstatement‐associated NAcore glutamatergic alterations. Rats were extinguished from nicotine self‐administration, followed by subchronic NAC administration (0 or 100 mg/kg/d) for 4 days prior to cue‐induced reinstatement. NAcore synaptic potentiation was measured via dendritic spine morphology and mRNA and protein of relevant glutamatergic genes were quantified. Nicotine‐seeking behavior was not reduced by subchronic NAC treatment. Also, NAcore transcript and protein expression of multiple glutamatergic genes, as well as spine morphological measures, were unaffected by subchronic NAC. Finally, chronic NAC treatment (15 days total) during extinction and prior to reinstatement significantly decreased extinction responding and reduced reinstatement of nicotine‐seeking compared to vehicle. Together, these results suggest that chronic NAC treatment is necessary for its therapeutic efficacy as a treatment strategy for nicotine addiction and relapse.
N‐acetylcysteine (NAC), a clinically approved antioxidant with some success in the treatment of substance use disorders (SUDs), decreased nicotine‐seeking when administered chronically. Subchronic NAC treatment did not reverse nicotine‐associated glutamatergic alterations in the nucleus accumbens core (NAcore) and was ineffective at reducing nicotine‐seeking. Specifically, NAC was unable to alter dendritic spine morphology during reinstated nicotine‐seeking and did not rescue other neurobiological alterations. These results suggest that subchronic NAC may not reverse all glutamatergic changes associated with nicotine relapse vulnerability.
Journal Article
Comparison of breeding values estimated between single-tree and multiple-tree plots for a slash pine population
by
Powell, Gregory L.
,
Peter, Gary F.
,
Zhang, Jianxing
in
Biomedical and Life Sciences
,
Biotechnology
,
Breeding
2015
Forest tree breeders often use single-tree plots, rather than multiple-tree plots, to maximize the number of genotypes tested, increase precision of genetic predictions, and achieve greater genetic gains per unit of time. However, genetically improved individuals are deployed operationally on large tracts of land, as stands, more like multiple-tree plots. This raises the concern that breeding values estimated from single-tree tests are not well correlated with those from large multiple-tree (i.e., block) plots. Comparisons of breeding values from single-tree and multiple-tree plots are largely missing, due to the cost and time associated with establishing and measuring block plots. To address this need, breeding values were evaluated from a second breeding cycle of slash pine that established two polymix single-tree plot trial series and one trial series of full-sib block plots (FSBP). The first polymix series (PMX I) evaluated 140 families, and the second series (PMX II) evaluated 201 polymix families and 43 elite full-sib crosses. Each polymix series had eight sites established in Florida and Georgia, USA. The FSBP series was established at 11 locations in Florida and Georgia with an average of 63 trees per unreplicated block plot for a total of 1141 full-sib families. Breeding values were estimated for each of the families based on fitting a global linear mixed model that included all series. Heritabilities for survival, volume, and rust were 0.15, 0.35, and 0.22, respectively, in PMX I, and 0.11, 0.18, and 0.11, respectively, in PMX II. Correlations between PMX and FSBP series parental breeding value estimates were higher than 0.84, 0.61, and 0.95 for survival, volume, and rust, respectively. Hence, moderate to strong agreement exists for the genetic rankings between single- and multiple-tree plots.
Journal Article
The PAX8/PPARγ fusion oncoprotein transforms immortalized human thyrocytes through a mechanism probably involving wild-type PPARγ inhibition
by
Kroll, Todd G
,
Deshpande, Seema S
,
Eberhardt, Norman L
in
Apoptosis
,
Biological and medical sciences
,
Cell Biology
2004
Follicular thyroid carcinoma (FTC) frequently harbors the
PAX8/PPARγ
fusion gene (
PPFP
); however, its oncogenic role and mechanism(s) of action remain undefined. We investigated PPFP's effects on cell growth, apoptosis, cell–cell, and cell–matrix interactions in immortalized human thyroid cells (Nthy-ori 3-1) and NIH 3T3 cells. PPFP expression increased the growth of transient and stable Nthy-ori transfectants (∼threefold by 72 h). There was an 8.4% increase of cells in the S+G2/M phase, a 7.8% decrease in cells in the G0+G1 phase and a 66% decline in apoptosis at 72 h. Stable Nthy-ori PPFP transfectants grew in soft agar, and
PPFP
-transfected NIH 3T3 cells exhibited efficient focus formation, suggesting loss of anchorage-dependent growth and contact inhibition, respectively. Overexpression of
PPARγ
in Nthy-ori cells did not recapitulate PPFP's growth effects. Treatment of Nthy-ori cells with an irreversible PPAR
γ
inhibitor mimicked the growth-promoting effects of PPFP and co-expression of PPFP and PPAR
γ
blocked PPAR
γ
transactivation activity. Our data provide functional evidence that
PPFP
acts as an oncoprotein, whose transforming properties depend in part on inhibition of PPAR
γ
. Our data suggest that PPFP contributes to malignant transformation during FTC oncogenesis by acting on several cellular pathways, at least some of which are normally regulated by PPAR
γ
.
Journal Article