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    Repeated closed-head mild traumatic brain injury-induced inflammation is associated with nociceptive sensitization
    (BMC, 2023-08-27) Nguyen, Tyler; Nguyen, Natalie; Cochran, Ashlyn G.; Smith, Jared A.; Al‑Juboori, Mohammed; Brumett, Andrew; Saxena, Saahil; Talley, Sarah; Campbell, Edward M.; Obukhov, Alexander G.; White, Fletcher A.; Anesthesia, School of Medicine
    Background: Individuals who have experienced mild traumatic brain injuries (mTBIs) suffer from several comorbidities, including chronic pain. Despite extensive studies investigating the underlying mechanisms of mTBI-associated chronic pain, the role of inflammation in long-term pain after mTBIs is not fully elucidated. Given the shifting dynamics of inflammation, it is important to understand the spatial-longitudinal changes in inflammatory processes following mTBIs and their effects on TBI-related pain. Methods: We utilized a recently developed transgenic caspase-1 luciferase reporter mouse model to monitor caspase-1 activation through a thinned skull window in the in vivo setting following three closed-head mTBI events. Organotypic coronal brain slice cultures and acutely dissociated dorsal root ganglion (DRG) cells provided tissue-relevant context of inflammation signal. Mechanical allodynia was assessed by mechanical withdrawal threshold to von Frey and thermal hyperalgesia withdrawal latency to radiant heat. Mouse grimace scale (MGS) was used to detect spontaneous or non-evoked pain. In some experiments, mice were prophylactically treated with MCC950, a potent small molecule inhibitor of NLRP3 inflammasome assembly to inhibit injury-induced inflammatory signaling. Bioluminescence spatiotemporal dynamics were quantified in the head and hind paws, and caspase-1 activation was confirmed by immunoblot. Immunofluorescence staining was used to monitor the progression of astrogliosis and microglial activation in ex vivo brain tissue following repetitive closed-head mTBIs. Results: Mice with repetitive closed-head mTBIs exhibited significant increases of the bioluminescence signals within the brain and paws in vivo for at least one week after each injury. Consistently, immunoblotting and immunofluorescence experiments confirmed that mTBIs led to caspase-1 activation, astrogliosis, and microgliosis. Persistent changes in MGS and hind paw withdrawal thresholds, indicative of pain states, were observed post-injury in the same mTBI animals in vivo. We also observed enhanced inflammatory responses in ex vivo brain slice preparations and DRG for at least 3 days following mTBIs. In vivo treatment with MCC950 significantly reduced caspase-1 activation-associated bioluminescent signals in vivo and decreased stimulus-evoked and non-stimulus evoked nociception. Conclusions: Our findings suggest that the inflammatory states in the brain and peripheral nervous system following repeated mTBIs are coincidental with the development of nociceptive sensitization, and that these events can be significantly reduced by inhibition of NLRP3 inflammasome activation.
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    Experimental pain and auditory sensitivity in overactive bladder syndrome: a Symptoms of the Lower Urinary Tract Dysfunction Research Network (LURN) Study
    (Wolters Kluwer, 2022) Harte, Steven E.; Wiseman, Jon; Wang, Ying; Smith, Abigail R.; Yang, Claire C.; Helmuth, Margaret; Kreder, Karl; Kruger, Grant H.; Gillespie, Brenda W.; Amundsen, Cindy; Kirkali, Ziya; Lai, H. Henry; LURN Study Group; Anesthesia, School of Medicine
    Purpose: The objective of this study was to investigate the presence of nonbladder sensory abnormalities in participants with overactive bladder syndrome (OAB). Materials and methods: Symptoms of Lower Urinary Tract Dysfunction Research Network (LURN) study participants with OAB symptoms and controls were recruited from 6 U.S. tertiary referral centers. Quantitative sensory testing (QST) was performed to determine pressure pain sensitivity at the thumbnail bed and auditory sensitivity. Fixed and mixed effect multivariable linear regressions and Weibull models were used to compare QST responses between groups. Pearson correlations were used to assess the relationship between QST measures. Associations between QST and self-reported symptoms were explored with linear regression. Results: A total of 297 participants were analyzed (191 OAB, 106 controls; 76% white, 51% male). OAB cases were older than controls (57.4 vs 52.2 years, p=0.015). No significant differences in experimental thumbnail (nonbladder) pain or auditory sensitivity were detected between OAB cases and controls. Correlations between pressure and auditory derived metrics were weak to moderate overall for both groups, with some significantly stronger correlations for cases. Exploratory analyses indicated increased pressure pain and auditory sensitivity were modestly associated with greater self-reported bladder pain and pain interference with physical function. Conclusions: As a group, no significant differences between OAB cases and controls were observed in experimental nonbladder pain or auditory sensitivity during QST. Associations between QST outcomes and clinical pain raise the possibility of centrally mediated sensory amplification in some individuals with OAB.
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    Repeated Mild Traumatic Brain Injury in Mice Elicits Long Term Innate Immune Cell Alterations in Blood, Spleen, and Brain
    (Elsevier, 2023) Smith, Jared A.; Nguyen, Tyler; Karnik, Sonali; Davis, Brittany C.; Al-Juboori, Mohammed H.; Kacena, Melissa A.; Obukhov, Alexander G.; White, Fletcher A.; Anesthesia, School of Medicine
    Mild traumatic brain injury is an insidious event whereby the initial injury leads to ongoing secondary neuro- and systemic inflammation through various cellular pathways lasting days to months after injury. Here, we investigated the impact of repeated mild traumatic brain injury (rmTBI) and the resultant systemic immune response in male C57B6 mice using flow cytometric methodology on white blood cells (WBCs) derived from the blood and spleen. Isolated mRNA derived from spleens and brains of rmTBI mice was assayed for changes in gene expression at one day, one week, and one month following the injury paradigm. We observed increases in Ly6C+, Ly6C-, and total monocyte percentages in both blood and spleen at one month after rmTBI. Differential gene expression analysis for the brain and spleen tissues uncovered significant changes in many genes, including csf1r, itgam, cd99, jak1,cd3ε, tnfaip6, and nfil3. Additional analysis revealed alterations in several immune signaling pathways over the course of one month in the brain and spleen of rmTBI mice. Together, these results indicate that rmTBI produces pronounced gene expression changes in the brain and spleen. Furthermore, our data suggest that monocyte populations may reprogram towards the proinflammatory phenotype over extended periods of time after rmTBI.
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    Liposomal bupivacaine reduces opioid requirements following Ravitch repair for pectus excavatum
    (Wolters Kluwer, 2023) Abbasi, Rania K.; Cossu, Anne E.; Tanner, Brandon; Castelluccio, Peter; Hamilton, Matthew; Brown, John; Herrmann, Jeremy; Anesthesia, School of Medicine
    Background and aims: The management of post-operative pain after surgical repair of pectus excavatum with the Ravitch procedure is challenging. Although previous studies have compared various methods of pain control in these patients, few have compared different local anesthetics. This retrospective analysis compares the use of bupivacaine to its longer-acting form, liposomal bupivacaine, in patients who had undergone pectus excavatum repair with the Ravitch method. Material and methods: Eleven patients who received local infiltration with liposomal bupivacaine were matched to 11 patients who received local infiltration utilizing bupivacaine with epinephrine. The primary outcome was total morphine milligram equivalents per kilogram body weight (MME/kg) over the complete length of hospital stay. Secondary outcomes included total cumulative diazepam, acetaminophen, ondansetron, and NSAID dose per kilogram body weight (mg/kg) over the course of the hospital stay, chest tube drainage (ml/kg body weight), number of post-operative hours until the first bowel movement, Haller Index, patient request for magnesium hydroxide, average pain scores from post-operative day 1 to post-operative day 5, and length of hospital stay. Continuous variables were reported as medians with inter-quartile ranges, and categorical values were reported as percentages and frequencies. Results: The total MME/kg [1.7 (1.2-2.4) vs 2.9 (2.0-3.9), P = 0.007] and hydromorphone (mg/kg) [0.1 (0.0-0.2) vs 0.3 (0.1-0.4), P = 0.006] use in the liposomal bupivacaine group versus bupivacaine with epinephrine was significantly reduced over total length of hospital stay. Similarly, there was a reduction in diazepam use in the liposomal bupivacaine group versus the bupivacaine group [0.4 (0.1-0.8) vs 0.6 (0.4-0.7), P = 0.249], but this did not reach statistical significance. The total dose of ondansetron (mg/kg) was not statistically different when comparing the liposomal bupivacaine group to the bupivacaine group [0.3 (0.0-0.5) vs 0.3 (0.2-0.6), P = 0.332]. Interestingly, the total dose of acetaminophen (mg/kg) was statistically increased in the liposomal bupivacaine group compared to the bupivacaine with epinephrine group [172 (138-183) vs 74 (55-111), P = 0.007]. Additionally, the total chest tube drainage (ml/kg) was significantly reduced in the liposomal bupivacaine group [9.3 (7.5-10.6) vs 12.8 (11.3-18.5), P = 0.027]. Finally, the percentage of patients without requests for magnesium hydroxide to promote laxation was significantly higher in the liposomal bupivacaine group than in the bupivacaine group (63.6% vs 18.2%, P = 0.027). Conclusion: The use of liposomal bupivacaine for local infiltration in patients who undergo the Ravitch procedure for pectus repair offers advantages over plain bupivacaine, including reduced opioid consumption and opioid-related side effects. However, more data are needed to understand the significance of these findings.
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    Long-COVID: Spotlight on National Institutes of Health Funding and Registered Trials
    (Mary Ann Liebert, 2022) Stone, Jennifer A. M.; Anesthesia, School of Medicine
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    Research objectives and general considerations for pragmatic clinical trials of pain treatments: IMMPACT statement
    (Wolters Kluwer, 2023) Hohenschurz-Schmidt, David J.; Cherkin, Dan; Rice, Andrew S. C.; Dworkin, Robert H.; Turk, Dennis C.; McDermott, Michael P.; Bair, Matthew J.; DeBar, Lynn L.; Edwards, Robert R.; Farrar, John T.; Kerns, Robert D.; Markman, John D.; Rowbotham, Michael C.; Sherman, Karen J.; Wasan, Ajay D.; Cowan, Penney; Desjardins, Paul; Ferguson, McKenzie; Freeman, Roy; Gewandter, Jennifer S.; Gilron, Ian; Grol-Prokopczyk, Hanna; Hertz, Sharon H.; Iyengar, Smriti; Kamp, Cornelia; Karp, Barbara I.; Kleykamp, Bethea A.; Loeser, John D.; Mackey, Sean; Malamut, Richard; McNicol, Ewan; Patel, Kushang V.; Sandbrink, Friedhelm; Schmader, Kenneth; Simon, Lee; Steiner, Deborah J.; Veasley, Christin; Vollert, Jan; Anesthesia, School of Medicine
    Many questions regarding the clinical management of people experiencing pain and related health policy decision-making may best be answered by pragmatic controlled trials. To generate clinically relevant and widely applicable findings, such trials aim to reproduce elements of routine clinical care or are embedded within clinical workflows. In contrast with traditional efficacy trials, pragmatic trials are intended to address a broader set of external validity questions critical for stakeholders (clinicians, healthcare leaders, policymakers, insurers, and patients) in considering the adoption and use of evidence-based treatments in daily clinical care. This article summarizes methodological considerations for pragmatic trials, mainly concerning methods of fundamental importance to the internal validity of trials. The relationship between these methods and common pragmatic trials methods and goals is considered, recognizing that the resulting trial designs are highly dependent on the specific research question under investigation. The basis of this statement was an Initiative on Methods, Measurement, and Pain Assessment in Clinical Trials (IMMPACT) systematic review of methods and a consensus meeting. The meeting was organized by the Analgesic, Anesthetic, and Addiction Clinical Trial Translations, Innovations, Opportunities, and Networks (ACTTION) public-private partnership. The consensus process was informed by expert presentations, panel and consensus discussions, and a preparatory systematic review. In the context of pragmatic trials of pain treatments, we present fundamental considerations for the planning phase of pragmatic trials, including the specification of trial objectives, the selection of adequate designs, and methods to enhance internal validity while maintaining the ability to answer pragmatic research questions.
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    Misreport of burns as a result of ‘coining’, Gua sha; inherent harms from publication and ongoing citation of false facts
    (Elsevier, 2023) Nielsen, Arya; Handel, Marsha; Stone, Jennifer A. M.; Lee, Myeong Soo; Anesthesia, School of Medicine
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    Long-Term Treatment with Gadopentetic Acid or Gadodiamide Increases TRPC5 Expression and Decreases Adriamycin Nuclear Accumulation in Breast Cancer Cells
    (MDPI, 2023-05-03) Zhang, Weiheng; Wang, Mengyuan; Lv, Weizhen; White, Fletcher A.; Chen, Xingjuan; Obukhov, Alexander G.; Anesthesia, School of Medicine
    Gadopentetic acid and gadodiamide are paramagnetic gadolinium-based contrast agents (GBCAs) that are routinely used for dynamic contrast-enhanced magnetic resonance imaging (MRI) to monitor disease progression in cancer patients. However, growing evidence indicates that repeated administration of GBCAs may lead to gadolinium (III) cation accumulation in the cortical bone tissue, skin, basal ganglia, and cerebellum, potentially leading to a subsequent slow long-term discharge of Gd3+. Gd3+ is a known activator of the TRPC5 channel that is implicated in breast cancer's resistance to chemotherapy. Herein, we found that gadopentetic acid (Gd-DTPA, 1 mM) potentiated the inward and outward currents through TRPC5 channels, which were exogenously expressed in HEK293 cells. Gd-DTPA (1 mM) also activated the Gd3+-sensitive R593A mutant of TRPC5, which exhibits a reduced sensitivity to GPCR-Gq/11-PLC dependent gating. Conversely, Gd-DTPA had no effect on TRPC5-E543Q, a Gd3+ insensitive TRPC5 mutant. Long-term treatment (28 days) of human breast cancer cells (MCF-7 and SK-BR-3) and adriamycin-resistant MCF-7 cells (MCF-7/ADM) with Gd-DTPA (1 mM) or gadodiamide (GDD, 1 mM) did not affect the IC50 values of ADM. However, treatment with Gd-DTPA or GDD significantly increased TRPC5 expression and decreased the accumulation of ADM in the nuclei of MCF-7 and SK-BR-3 cells, promoting the survival of these two breast cancer cells in the presence of ADM. The antagonist of TRPC5, AC1903 (1 μM), increased ADM nuclear accumulation induced by Gd-DTPA-treatment. These data indicate that prolonged GBCA treatment may lead to increased breast cancer cell survival owing to the upregulation of TRPC5 expression and the increased ADM resistance. We propose that while focusing on providing medical care of the best personalized quality in the clinic, excessive administration of GBCAs should be avoided in patients with metastatic breast cancer to reduce the risk of promoting breast cancer cell drug resistance.
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    459 Caspase-1 mediated inflammatory response - a critical player in concussive mild traumatic brain injury (mTBI) associated long term pain
    (Cambridge University Press, 2023-04-24) Nguyen, Tyler; Talley, Sarah; Nguyen, Natalie; Cochran, Ashlyn G.; Al-Juboori, Mohammed; Smith, Jared A.; Saxena, Saahil; Campbell, Edward M.; Obukhov, Alexander G.; White, Fletcher A.; Anesthesia, School of Medicine
    OBJECTIVES/GOALS: Patients who have experienced conjunctive mild traumatic brain injuries (mTBIs) suffer from a number of comorbidities, including chronic pain. Despite extensive studies investigating the underlying mechanisms of mTBI-associated chronic pain, the role of inflammation after mTBI and its contribution to long-term pain are still poorly understood. METHODS/STUDY POPULATION: Given the shifting dynamics of inflammation, it is important to understand the spatial-longitudinal changes and their effects on TBI-related pain. Utilizing a recently developed transgenic caspase-1 luciferase reporter mouse, we characterized the bioluminescence signal evident in both in vivo and ex vivo tissues following repetitive closed head mTBIs. This allowed us to reveal the spatiotemporal dynamics of caspase-1 activation in individual animals over time. Furthermore, we utilize various proteomic and behavioral assays to evaluate the role of caspase-1 mediated inflammation in the development and progression of injury-associated chronic pain. Lastly, by blocking inflammasome caspase-1 activation with a specific inhibitor, we assess its clinical potential as the next therapeutic approach to pain. RESULTS/ANTICIPATED RESULTS: We established that there were significant increases in bioluminescent signals upon protease cleavage in the brain, thorax, abdomen, and paws in vivo, which lasted for at least one week after each injury. Enhanced inflammation was also observed in ex vivo brain slice preparations following injury events that lasted for at least 3 days. Concurrent with the in vivo detection of the bioluminescent signal were persistent decreases in mouse hind paw withdrawal thresholds that lasted for more than two months postinjury. Using MCC950, a potent small molecule inhibitor of NLRP3 inflammasome-caspase 1 activity, we observed reductions in both caspase-1 bioluminescent signals in vivo and caspase-1 p45 expression by immunoblotting and an increase in hind paw withdrawal thresholds. DISCUSSION/SIGNIFICANCE: Overall, these findings suggest that neuroinflammation in the brain following repeated mTBIs is coincidental with a chronic nociplastic pain state, and repeated mTBI-associated events can be ameliorated by a highly specific small molecule inhibitor of NLRP3 inflammasome activation.