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Zhang D, Tu H, Wang C, Cao L, Hu W, Hackfort BT, Muelleman RL, Wadman MC, Li YL. Inhibition of N-type calcium channels in cardiac sympathetic neurons attenuates ventricular arrhythmogenesis in heart failure. Cardiovasc Res 2021; 117:137-148. [PMID: 31995173 PMCID: PMC7797209 DOI: 10.1093/cvr/cvaa018] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/13/2019] [Revised: 11/13/2019] [Accepted: 01/21/2020] [Indexed: 02/07/2023] Open
Abstract
AIMS Cardiac sympathetic overactivation is an important trigger of ventricular arrhythmias in patients with chronic heart failure (CHF). Our previous study demonstrated that N-type calcium (Cav2.2) currents in cardiac sympathetic post-ganglionic (CSP) neurons were increased in CHF. This study investigated the contribution of Cav2.2 channels in cardiac sympathetic overactivation and ventricular arrhythmogenesis in CHF. METHODS AND RESULTS Rat CHF was induced by surgical ligation of the left coronary artery. Lentiviral Cav2.2-α shRNA or scrambled shRNA was transfected in vivo into stellate ganglia (SG) in CHF rats. Final experiments were performed at 14 weeks after coronary artery ligation. Real-time polymerase chain reaction and western blot data showed that in vivo transfection of Cav2.2-α shRNA reduced the expression of Cav2.2-α mRNA and protein in the SG in CHF rats. Cav2.2-α shRNA also reduced Cav2.2 currents and cell excitability of CSP neurons and attenuated cardiac sympathetic nerve activities (CSNA) in CHF rats. The power spectral analysis of heart rate variability (HRV) further revealed that transfection of Cav2.2-α shRNA in the SG normalized CHF-caused cardiac sympathetic overactivation in conscious rats. Twenty-four-hour continuous telemetry electrocardiogram recording revealed that this Cav2.2-α shRNA not only decreased incidence and duration of ventricular tachycardia/ventricular fibrillation but also improved CHF-induced heterogeneity of ventricular electrical activity in conscious CHF rats. Cav2.2-α shRNA also decreased susceptibility to ventricular arrhythmias in anaesthetized CHF rats. However, Cav2.2-α shRNA failed to improve CHF-induced cardiac contractile dysfunction. Scrambled shRNA did not affect Cav2.2 currents and cell excitability of CSP neurons, CSNA, HRV, and ventricular arrhythmogenesis in CHF rats. CONCLUSIONS Overactivation of Cav2.2 channels in CSP neurons contributes to cardiac sympathetic hyperactivation and ventricular arrhythmogenesis in CHF. This suggests that discovering purely selective and potent small-molecule Cav2.2 channel blockers could be a potential therapeutic strategy to decrease fatal ventricular arrhythmias in CHF.
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MESH Headings
- Action Potentials
- Animals
- Calcium/metabolism
- Calcium Channels, N-Type/genetics
- Calcium Channels, N-Type/metabolism
- Calcium Signaling
- Cells, Cultured
- Disease Models, Animal
- Heart/innervation
- Heart Failure/genetics
- Heart Failure/metabolism
- Heart Failure/physiopathology
- Heart Rate
- Male
- RNA Interference
- RNA, Small Interfering/genetics
- RNA, Small Interfering/metabolism
- Rats, Sprague-Dawley
- Stellate Ganglion/metabolism
- Stellate Ganglion/physiopathology
- Sympathetic Fibers, Postganglionic/metabolism
- Sympathetic Fibers, Postganglionic/physiopathology
- Tachycardia, Ventricular/genetics
- Tachycardia, Ventricular/metabolism
- Tachycardia, Ventricular/physiopathology
- Tachycardia, Ventricular/prevention & control
- Ventricular Fibrillation/genetics
- Ventricular Fibrillation/metabolism
- Ventricular Fibrillation/physiopathology
- Ventricular Fibrillation/prevention & control
- Rats
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Affiliation(s)
- Dongze Zhang
- Department of Emergency Medicine, University of Nebraska Medical Center, 985850 Nebraska Medical Center, Omaha, NE 68198-5850, USA
| | - Huiyin Tu
- Department of Emergency Medicine, University of Nebraska Medical Center, 985850 Nebraska Medical Center, Omaha, NE 68198-5850, USA
| | - Chaojun Wang
- Department of Emergency Medicine, University of Nebraska Medical Center, 985850 Nebraska Medical Center, Omaha, NE 68198-5850, USA
- Department of Cardiovascular Disease, the First Affiliated Hospital of Xi’an Jiaotong University, Xi’an, Shaanxi, 710061, China
| | - Liang Cao
- Department of Emergency Medicine, University of Nebraska Medical Center, 985850 Nebraska Medical Center, Omaha, NE 68198-5850, USA
- Department of Cardiac Surgery, Second Xiangya Hospital, Central South University, Changsha 410011, China
| | - Wenfeng Hu
- Department of Emergency Medicine, University of Nebraska Medical Center, 985850 Nebraska Medical Center, Omaha, NE 68198-5850, USA
| | - Bryan T Hackfort
- Department of Cellular & Integrative Physiology, University of Nebraska Medical Center, Omaha, NE 68198, USA
| | - Robert L Muelleman
- Department of Emergency Medicine, University of Nebraska Medical Center, 985850 Nebraska Medical Center, Omaha, NE 68198-5850, USA
| | - Michael C Wadman
- Department of Emergency Medicine, University of Nebraska Medical Center, 985850 Nebraska Medical Center, Omaha, NE 68198-5850, USA
| | - Yu-Long Li
- Department of Emergency Medicine, University of Nebraska Medical Center, 985850 Nebraska Medical Center, Omaha, NE 68198-5850, USA
- Department of Cellular & Integrative Physiology, University of Nebraska Medical Center, Omaha, NE 68198, USA
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Tu H, Zhang D, Barksdale AN, Wadman MC, Muelleman RL, Li YL. Dexamethasone Improves Wound Healing by Decreased Inflammation and Increased Vasculogenesis in Mouse Skin Frostbite Model. Wilderness Environ Med 2020; 31:407-417. [PMID: 33077334 DOI: 10.1016/j.wem.2020.07.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2019] [Revised: 06/22/2020] [Accepted: 07/17/2020] [Indexed: 01/16/2023]
Abstract
INTRODUCTION Frostbite is thought to result from initial vasoconstriction, ischemia, intracellular ice crystal formation, and inflammation caused by reperfusion injury. Corticosteroids have demonstrated beneficial anti-inflammatory effects in the treatment of other ischemia/reperfusion clinical conditions. The objective of this study was to determine the effect of dexamethasone (dex) on wound healing, inflammatory response, and vasculogenesis in a mouse skin frostbite model. METHODS Treatment and control groups of C57/BL6 mice were subjected to frostbite using a previously described model. Treatment with intraperitoneal dex (1 mg·kg-1·d-1) began on the day of frostbite induction and lasted for 7 d. Over 4 wk, we compared wound diameter; morphology by visual inspection, hematoxylin-eosin staining, and Masson's trichrome staining; density of inflammatory cytokines IL-1β and TNFα using Western blot analysis; and formation of microvasculature using immunofluorescence staining. Data were analyzed using 1-way or 1-way repeated-measures analysis of variance. RESULTS After frostbite injury, morphological images demonstrated epidermal necrosis and loss in the frostbitten skin as well as infiltration of inflammation-related leukocytes. Increased production of inflammatory cytokines and disappearance of the microvasculature also occurred in the frostbitten skin. In comparison to the control group, treatment with dex promoted wound healing as demonstrated by decreased wound diameter; decreased levels of inflammatory cytokines, and accelerated formation of mature microvasculature. CONCLUSIONS In this animal model, dex improved wound healing in frostbitten skin and demonstrated both anti-inflammatory effects and stimulation of vasculogenesis. This study suggests that the use of potent anti-inflammatory agents may be an effective strategy for mitigating frostbite injury.
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Affiliation(s)
- Huiyin Tu
- Department of Emergency Medicine, University of Nebraska Medical Center, Omaha, NE
| | - Dongze Zhang
- Department of Emergency Medicine, University of Nebraska Medical Center, Omaha, NE
| | - Aaron N Barksdale
- Department of Emergency Medicine, University of Nebraska Medical Center, Omaha, NE
| | - Michael C Wadman
- Department of Emergency Medicine, University of Nebraska Medical Center, Omaha, NE
| | - Robert L Muelleman
- Department of Emergency Medicine, University of Nebraska Medical Center, Omaha, NE.
| | - Yu-Long Li
- Department of Emergency Medicine, University of Nebraska Medical Center, Omaha, NE
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Tu H, Zhang D, Wadman MC, Muelleman RL, Li YL. Anti‐inflammation Ameliorates Repairment of Frostbite‐induced Skin Injuries. FASEB J 2020. [DOI: 10.1096/fasebj.2020.34.s1.02488] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Huiyin Tu
- University of Nebraska Medical Center
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Nelson LS, Keim SM, Beeson MS, Chudnofsky CR, Gausche-Hill M, Gorgas DL, Goyal DG, Kowalenko T, Muelleman RL, Joldersma KB, Johnston MM. American Board of Emergency Medicine Report on Residency and Fellowship Training Information (2018-2019). Ann Emerg Med 2019; 73:524-541. [DOI: 10.1016/j.annemergmed.2019.03.024] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Nelson LS, Keim SM, Baren JM, Beeson MS, Carius ML, Chudnofsky CR, Gausche-Hill M, Goyal DG, Kowalenko T, Marco CA, Muelleman RL, Johnston MM, Joldersma KB. American Board of Emergency Medicine Report on Residency and Fellowship Training Information (2017-2018). Ann Emerg Med 2018; 71:636-648. [PMID: 29681310 DOI: 10.1016/j.annemergmed.2018.03.037] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
The American Board of Emergency Medicine (ABEM) gathers extensive background information on emergency medicine-sponsored residency and fellowship programs, as well as the residents and fellows training in those programs. We present the 2018 annual report on the status of US emergency medicine training programs.
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Corrick RM, Tu H, Zhang D, Barksdale AN, Muelleman RL, Wadman MC, Li YL. Dexamethasone Protects Against Tourniquet-Induced Acute Ischemia-Reperfusion Injury in Mouse Hindlimb. Front Physiol 2018; 9:244. [PMID: 29615933 PMCID: PMC5870039 DOI: 10.3389/fphys.2018.00244] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2018] [Accepted: 03/06/2018] [Indexed: 01/21/2023] Open
Abstract
Extremity injuries with hemorrhage have been a significant cause of death in civilian medicine and on the battlefield. The use of a tourniquet as an intervention is necessary for treatment to an injured limb; however, the tourniquet and subsequent release results in serious acute ischemia-reperfusion (IR) injury in the skeletal muscle and neuromuscular junction (NMJ). Much evidence demonstrates that inflammation is an important factor to cause acute IR injury. To find effective therapeutic interventions for tourniquet-induced acute IR injuries, our current study investigated effect of dexamethasone, an anti-inflammatory drug, on tourniquet-induced acute IR injury in mouse hindlimb. In C57/BL6 mice, a tourniquet was placed on unilateral hindlimb (left hindlimb) at the hip joint for 3 h, and then released for 24 h to induce IR. Three hours of tourniquet and 24 h of release (24-h IR) caused gastrocnemius muscle injuries including rupture of the muscle sarcolemma and necrosis (42.8 ± 2.3% for infarct size of the gastrocnemius muscle). In the NMJ, motor nerve terminals disappeared, and endplate potentials were undetectable in 24-h IR mice. There was no gastrocnemius muscle contraction in 24-h IR mice. Western blot data showed that inflammatory cytokines (TNFα and IL-1β) were increased in the gastrocnemius muscle after 24-h IR. Treatment with dexamethasone at the beginning of reperfusion (1 mg/kg, i.p.) significantly inhibited expression of TNFα and IL-1β, reduced rupture of the muscle sarcolemma and infarct size (24.8 ± 2.0%), and improved direct muscle stimulation-induced gastrocnemius muscle contraction in 24-h IR mice. However, this anti-inflammatory drug did not improve NMJ morphology and function, and sciatic nerve-stimulated skeletal muscle contraction in 24-h IR mice. The data suggest that one-time treatment with dexamethasone at the beginning of reperfusion only reduced structural and functional impairments of the skeletal muscle but not the NMJ through inhibiting inflammatory cytokines.
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Affiliation(s)
- Ryan M Corrick
- Department of Emergency Medicine, University of Nebraska Medical Center, Omaha, NE, United States
| | - Huiyin Tu
- Department of Emergency Medicine, University of Nebraska Medical Center, Omaha, NE, United States
| | - Dongze Zhang
- Department of Emergency Medicine, University of Nebraska Medical Center, Omaha, NE, United States
| | - Aaron N Barksdale
- Department of Emergency Medicine, University of Nebraska Medical Center, Omaha, NE, United States
| | - Robert L Muelleman
- Department of Emergency Medicine, University of Nebraska Medical Center, Omaha, NE, United States
| | - Michael C Wadman
- Department of Emergency Medicine, University of Nebraska Medical Center, Omaha, NE, United States
| | - Yu-Long Li
- Department of Emergency Medicine, University of Nebraska Medical Center, Omaha, NE, United States
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Zhang D, Tu H, Cao L, Zheng H, Muelleman RL, Wadman MC, Li YL. Reduced N-Type Ca 2+ Channels in Atrioventricular Ganglion Neurons Are Involved in Ventricular Arrhythmogenesis. J Am Heart Assoc 2018; 7:JAHA.117.007457. [PMID: 29335317 PMCID: PMC5850164 DOI: 10.1161/jaha.117.007457] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Background Attenuated cardiac vagal activity is associated with ventricular arrhythmogenesis and related mortality in patients with chronic heart failure. Our recent study has shown that expression of N‐type Ca2+ channel α‐subunits (Cav2.2‐α) and N‐type Ca2+ currents are reduced in intracardiac ganglion neurons from rats with chronic heart failure. Rat intracardiac ganglia are divided into the atrioventricular ganglion (AVG) and sinoatrial ganglion. Ventricular myocardium receives projection of neuronal terminals only from the AVG. In this study we tested whether a decrease in N‐type Ca2+ channels in AVG neurons contributes to ventricular arrhythmogenesis. Methods and Results Lentiviral Cav2.2‐α shRNA (2 μL, 2×107 pfu/mL) or scrambled shRNA was in vivo transfected into rat AVG neurons. Nontransfected sham rats served as controls. Using real‐time single‐cell polymerase chain reaction and reverse‐phase protein array, we found that in vivo transfection of Cav2.2‐α shRNA decreased expression of Cav2.2‐α mRNA and protein in rat AVG neurons. Whole‐cell patch‐clamp data showed that Cav2.2‐α shRNA reduced N‐type Ca2+ currents and cell excitability in AVG neurons. The data from telemetry electrocardiographic recording demonstrated that 83% (5 out of 6) of conscious rats with Cav2.2‐α shRNA transfection had premature ventricular contractions (P<0.05 versus 0% of nontransfected sham rats or scrambled shRNA‐transfected rats). Additionally, an index of susceptibility to ventricular arrhythmias, inducibility of ventricular arrhythmias evoked by programmed electrical stimulation, was higher in rats with Cav2.2‐α shRNA transfection compared with nontransfected sham rats and scrambled shRNA‐transfected rats. Conclusions A decrease in N‐type Ca2+ channels in AVG neurons attenuates vagal control of ventricular myocardium, thereby initiating ventricular arrhythmias.
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Affiliation(s)
- Dongze Zhang
- Department of Emergency Medicine, University of Nebraska Medical Center, Omaha, NE
| | - Huiyin Tu
- Department of Emergency Medicine, University of Nebraska Medical Center, Omaha, NE
| | - Liang Cao
- Department of Emergency Medicine, University of Nebraska Medical Center, Omaha, NE.,Department of Cardiac surgery, Second Xiangya Hospital, Central South University, Changsha, China
| | - Hong Zheng
- Department of Cellular & Integrative Physiology, University of Nebraska Medical Center, Omaha, NE
| | - Robert L Muelleman
- Department of Emergency Medicine, University of Nebraska Medical Center, Omaha, NE
| | - Michael C Wadman
- Department of Emergency Medicine, University of Nebraska Medical Center, Omaha, NE
| | - Yu-Long Li
- Department of Emergency Medicine, University of Nebraska Medical Center, Omaha, NE .,Department of Cellular & Integrative Physiology, University of Nebraska Medical Center, Omaha, NE
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Beeson MS, Hamstra SJ, Barton MA, Yamazaki K, Counselman FL, Shayne PH, Holmboe ES, Muelleman RL, Reisdorff EJ. Straight Line Scoring by Clinical Competency Committees Using Emergency Medicine Milestones. J Grad Med Educ 2017; 9:716-720. [PMID: 29270260 PMCID: PMC5734325 DOI: 10.4300/jgme-d-17-00304.1] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/25/2017] [Revised: 07/25/2017] [Accepted: 08/07/2017] [Indexed: 11/06/2022] Open
Abstract
BACKGROUND In 2013, milestone ratings became a reporting requirement for emergency medicine (EM) residency programs. Programs rate each resident in the fall and spring on 23 milestone subcompetencies. OBJECTIVE This study examined the incidence of straight line scoring (SLS) for EM Milestone ratings, defined as a resident being assessed the same score across the milestone subcompetencies. METHODS This descriptive analysis measured the frequencies of SLS for all Accreditation Council for Graduate Medical Education (ACGME)-accredited EM programs during the 2015-2016 academic year. Outcomes were the frequency of SLS in the fall and spring milestone assessments, changes in the number of SLS reports, and reporting trends. Chi-square analysis compared nominal variables. RESULTS There were 6257 residents in the fall and 6588 in the spring. Milestone scores were reported for 6173 EM residents in the fall (99% of 6257) and spring (94% of 6588). In the fall, 93% (5753 residents) did not receive SLS ratings and 420 (7%) did, with no significant difference compared with the spring (5776 [94%] versus 397 [6%]). Subgroup analysis showed higher SLS results for residents' first ratings (183 of 2136 versus 237 of 4220, P < .0001) and for their final ratings (200 of 2019 versus 197 of 4354, P < .0001). Twenty percent of programs submitted 10% or more SLS ratings, and a small percentage submitted more than 50% of ratings as SLS. CONCLUSIONS Most programs did not submit SLS ratings. Because of the statistical improbability of SLS, any SLS ratings reduce the validity assertions of the milestone assessments.
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Marco CA, Nelson LS, Baren JM, Beeson MS, Carius ML, Chudnofsky CR, Gausche-Hill M, Goyal DG, Keim SM, Kowalenko T, Muelleman RL, Joldersma KB. American Board of Emergency Medicine Report on Residency and Fellowship Training Information (2016-2017). Ann Emerg Med 2017; 69:640-652. [PMID: 28442084 DOI: 10.1016/j.annemergmed.2017.03.025] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
The American Board of Emergency Medicine (ABEM) gathers extensive background information on emergency medicine residency programs and the residents training in those programs. We present the 2017 annual report on the status of US emergency medicine training programs.
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Zhang D, Tu H, Wang C, Cao L, Muelleman RL, Wadman MC, Li YL. Correlation of Ventricular Arrhythmogenesis with Neuronal Remodeling of Cardiac Postganglionic Parasympathetic Neurons in the Late Stage of Heart Failure after Myocardial Infarction. Front Neurosci 2017; 11:252. [PMID: 28533740 PMCID: PMC5420597 DOI: 10.3389/fnins.2017.00252] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2017] [Accepted: 04/20/2017] [Indexed: 01/06/2023] Open
Abstract
Introduction: Ventricular arrhythmia is a major cause of sudden cardiac death in patients with chronic heart failure (CHF). Our recent study demonstrates that N-type Ca2+ currents in intracardiac ganglionic neurons are reduced in the late stage of CHF rats. Rat intracardiac ganglia are divided into the atrioventricular ganglion (AVG) and sinoatrial ganglion. Only AVG nerve terminals innervate the ventricular myocardium. In this study, we tested the correlation of electrical remodeling in AVG neurons with ventricular arrhythmogenesis in CHF rats. Methods and Results: CHF was induced in male Sprague-Dawley rats by surgical ligation of the left coronary artery. The data from 24-h continuous radiotelemetry ECG recording in conscious rats showed that ventricular tachycardia/fibrillation (VT/VF) occurred in 3 and 14-week CHF rats but not 8-week CHF rats. Additionally, as an index for vagal control of ventricular function, changes of left ventricular systolic pressure (LVSP) and the maximum rate of left ventricular pressure rise (LV dP/dtmax) in response to vagal efferent nerve stimulation were blunted in 14-week CHF rats but not 3 or 8-week CHF rats. Results from whole-cell patch clamp recording demonstrated that N-type Ca2+ currents in AVG neurons began to decrease in 8-week CHF rats, and that there was also a significant decrease in 14-week CHF rats. Correlation analysis revealed that N-type Ca2+ currents in AVG neurons negatively correlated with the cumulative duration of VT/VF in 14-week CHF rats, whereas there was no correlation between N-type Ca2+ currents in AVG neurons and the cumulative duration of VT/VF in 3-week CHF. Conclusion: Malignant ventricular arrhythmias mainly occur in the early and late stages of CHF. Electrical remodeling of AVG neurons highly correlates with the occurrence of ventricular arrhythmias in the late stage of CHF.
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Affiliation(s)
- Dongze Zhang
- Department of Emergency Medicine, University of Nebraska Medical CenterOmaha, NE, USA
| | - Huiyin Tu
- Department of Emergency Medicine, University of Nebraska Medical CenterOmaha, NE, USA
| | - Chaojun Wang
- Department of Emergency Medicine, University of Nebraska Medical CenterOmaha, NE, USA.,Department of Cardiovascular Disease, The First Affiliated Hospital of Xi'an Jiaotong UniversityXi'an, China
| | - Liang Cao
- Department of Emergency Medicine, University of Nebraska Medical CenterOmaha, NE, USA.,Department of Cardiac Surgery, Second Xiangya Hospital, Central South UniversityChangsha, China
| | - Robert L Muelleman
- Department of Emergency Medicine, University of Nebraska Medical CenterOmaha, NE, USA
| | - Michael C Wadman
- Department of Emergency Medicine, University of Nebraska Medical CenterOmaha, NE, USA
| | - Yu-Long Li
- Department of Emergency Medicine, University of Nebraska Medical CenterOmaha, NE, USA.,Department of Cellular & Integrative Physiology, University of Nebraska Medical CenterOmaha, NE, USA
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Tu H, Zhang D, Corrick RM, Muelleman RL, Wadman MC, Li YL. Morphological Regeneration and Functional Recovery of Neuromuscular Junctions after Tourniquet-Induced Injuries in Mouse Hindlimb. Front Physiol 2017; 8:207. [PMID: 28428759 PMCID: PMC5382216 DOI: 10.3389/fphys.2017.00207] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2016] [Accepted: 03/21/2017] [Indexed: 02/04/2023] Open
Abstract
Tourniquet application and its subsequent release cause serious injuries to the skeletal muscle, nerve, and neuromuscular junction (NMJ) due to mechanical compression and ischemia-reperfusion (IR). Monitoring structural and functional repair of the NMJ, nerve, and skeletal muscle after tourniquet-induced injuries is beneficial in exploring potential cellular and molecular mechanisms responsible for tourniquet-induced injuries, and for establishing effective therapeutic interventions. Here, we observed long-term morphological and functional changes of the NMJ in a murine model of tourniquet-induced hindlimb injuries. Unilateral hindlimbs of C57/BL6 mice were subjected to 3 h of tourniquet by placing an orthodontic rubber band, followed by varied periods of tourniquet release (1 day, 3 days, 1 week, 2 weeks, 4 weeks, and 6 weeks). NMJ morphology in the gastrocnemius muscle was imaged, and the endplate potential (EPP) was recorded to evaluate NMJ function. In NMJs, nicotinic acetylcholine receptor (nAChR) clusters normally displayed an intact, pretzel-like shape, and all nAChR clusters were innervated (100%) by motor nerve terminals. During 3 h of tourniquet application and varied periods of tourniquet release, NMJs in the gastrocnemius muscle were characterized by morphological and functional changes. At 1 day and 3 days of tourniquet release, nAChR clusters retained normal, pretzel-like shapes, whereas motor nerve terminals were completely destroyed and no EPPs recorded. From 1 to 6 weeks of tourniquet release, motor nerve terminals gradually regenerated, even reaching that seen in sham mice, whereas nAChR clusters were gradually fragmented with prolongation of tourniquet release. Additionally, the amplitude of EPPs gradually increased with prolongation of tourniquet release. However, even at 6 weeks after tourniquet release, the amplitude of EPPs did not restore to the level seen in sham mice (13.9 ± 1.1 mV, p < 0.05 vs. sham mice, 29.8 ± 1.0 mV). The data suggest that tourniquet application and subsequent release impair the structure and function of NMJs. Morphological change in motor nerve terminals is faster than in nAChR clusters in NMJs. Slow restoration of fragmented nAChR clusters possibly dampens neuromuscular transmission during the long phase following tourniquet release.
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Affiliation(s)
- Huiyin Tu
- Department of Emergency Medicine, University of Nebraska Medical CenterOmaha, NE, USA
| | - Dongze Zhang
- Department of Emergency Medicine, University of Nebraska Medical CenterOmaha, NE, USA
| | - Ryan M Corrick
- Department of Emergency Medicine, University of Nebraska Medical CenterOmaha, NE, USA
| | - Robert L Muelleman
- Department of Emergency Medicine, University of Nebraska Medical CenterOmaha, NE, USA
| | - Michael C Wadman
- Department of Emergency Medicine, University of Nebraska Medical CenterOmaha, NE, USA
| | - Yu-Long Li
- Department of Emergency Medicine, University of Nebraska Medical CenterOmaha, NE, USA.,Department of Cellular and Integrative Physiology, Nebraska Medical CenterOmaha, NE, USA
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Li YL, Zhang D, Tu H, Muelleman RL. Altered ENaC is Associated With Aortic Baroreceptor Dysfunction in Chronic Heart Failure. Am J Hypertens 2016; 29:582-9. [PMID: 26297031 DOI: 10.1093/ajh/hpv141] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2015] [Accepted: 07/28/2015] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Abnormal baroreceptor function contributes to attenuated arterial baroreflex sensitivity in chronic heart failure (CHF). As a mechanosensor in mammalian nonepithelium, the epithelial sodium channel (ENaC) is an amiloride-sensitive and voltage-independent ion channel. The ENaC is thought to be a component of baroreceptor mechanosensitive ion channels in aortic baroreceptor cell bodies and nerve terminals. In this study, therefore, we measured the expression and activation of the ENaC in nodose neuronal cell bodies and aortic baroreceptor nerve terminals in sham and CHF rats. METHODS AND RESULTS CHF was induced by surgical ligation of left coronary artery. The development of CHF was confirmed by hemodynamic and morphological characteristics. The aortic baroreceptor sensitivity was blunted in anesthetized CHF rats, compared with that in sham rats. The data from immunostaining and western blot analysis showed that the protein of β- and γ-ENaC subunits was expressed in nodose neuronal cell bodies and aortic baroreceptor nerve terminals, whereas the protein of α-ENaC subunit was undetectable. CHF reduced protein expression of β- and γ-ENaC subunits in nodose neuronal cell bodies and aortic baroreceptor nerve terminals. Additionally, the data recorded by the whole cell patch-clamp technique demonstrated that ENaC currents in aortic baroreceptor neurons were lower in CHF rats than that in sham rats. CONCLUSION These results suggest that reduced protein expression of the ENaC decreases the ENaC activation, which could be involved in attenuation of the aortic baroreceptor sensitivity in the CHF state. Baroreceptors should be a potential therapeutic target for reducing mortality in CHF.
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Affiliation(s)
- Yu-Long Li
- Department of Emergency Medicine, University of Nebraska Medical Center, Omaha, Nebraska, USA; Department of Cellular and integrative Physiology, University of Nebraska Medical Center, Omaha, Nebraska, USA.
| | - Dongze Zhang
- Department of Emergency Medicine, University of Nebraska Medical Center, Omaha, Nebraska, USA
| | - Huiyin Tu
- Department of Emergency Medicine, University of Nebraska Medical Center, Omaha, Nebraska, USA
| | - Robert L Muelleman
- Department of Emergency Medicine, University of Nebraska Medical Center, Omaha, Nebraska, USA
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Marco CA, Baren JM, Beeson MS, Carius ML, Counselman FL, Gausche-Hill M, Goyal DG, Kowalenko T, Muelleman RL, Nelson LS, Wahl RP, Joldersma KB. American Board of Emergency Medicine Report on Residency Training Information (2015-2016). Ann Emerg Med 2016; 67:654-66. [PMID: 27106370 DOI: 10.1016/j.annemergmed.2016.03.031] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The American Board of Emergency Medicine (ABEM) gathers extensive background information on emergency medicine residency programs and the residents training in those programs. We present the 2016 annual report on the status of US emergency medicine training programs.
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Zhang D, Muelleman RL, Li YL. Angiotensin II-superoxide-NFκB signaling and aortic baroreceptor dysfunction in chronic heart failure. Front Neurosci 2015; 9:382. [PMID: 26528122 PMCID: PMC4607814 DOI: 10.3389/fnins.2015.00382] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2015] [Accepted: 10/02/2015] [Indexed: 11/13/2022] Open
Abstract
Chronic heart failure (CHF) affects approximately 5.7 million people in the United States. Increasing evidence from both clinical and experimental studies indicates that the sensitivity of arterial baroreflex is blunted in the CHF state, which is a predictive risk factor for sudden cardiac death. Normally, the arterial baroreflex regulates blood pressure and heart rate through sensing mechanical alteration of arterial vascular walls by baroreceptor terminals in the aortic arch and carotid sinus. There are aortic baroreceptor neurons in the nodose ganglion (NG), which serve as the main afferent component of the arterial baroreflex. Functional changes of baroreceptor neurons are involved in the arterial baroreflex dysfunction in CHF. In the CHF state, circulating angiotensin II (Ang II) and local Ang II concentration in the NG are elevated, and AT1R mRNA and protein are overexpressed in the NG. Additionally, Ang II-superoxide-NFκB signaling pathway regulates the neuronal excitability of aortic baroreceptors through influencing the expression and activation of Nav channels in aortic baroreceptors, and subsequently causes the impairment of the arterial baroreflex in CHF. These new findings provide a basis for potential pharmacological interventions for the improvement of the arterial baroreflex sensitivity in the CHF state. This review summarizes the mechanisms responsible for the arterial baroreflex dysfunction in CHF.
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Affiliation(s)
- Dongze Zhang
- Department of Emergency Medicine, University of Nebraska Medical Center Omaha, NE, USA
| | - Robert L Muelleman
- Department of Emergency Medicine, University of Nebraska Medical Center Omaha, NE, USA
| | - Yu-Long Li
- Department of Emergency Medicine, University of Nebraska Medical Center Omaha, NE, USA
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15
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Wadman MC, Schwedhelm SS, Watson S, Swanhorst J, Gibbs SG, Lowe JJ, Iwen PC, Hayes AK, Needham S, Johnson DW, Kalin DJ, Zeger WG, Muelleman RL. Emergency Department Processes for the Evaluation and Management of Persons Under Investigation for Ebola Virus Disease. Ann Emerg Med 2015; 66:306-14. [PMID: 26003001 DOI: 10.1016/j.annemergmed.2015.04.020] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2015] [Revised: 04/03/2015] [Accepted: 04/14/2015] [Indexed: 11/28/2022]
Abstract
INTRODUCTION Due to the recent Ebola virus outbreak in West Africa, patients with epidemiologic risk for Ebola virus disease and symptoms consistent with Ebola virus disease are presenting to emergency departments (EDs) and clinics in the United States. These individuals, identified as a person under investigation for Ebola virus disease, are initially screened using a molecular assay for Ebola virus. If this initial test is negative and the person under investigation has been symptomatic for < 3 days, a repeat test is required after 3 days of symptoms to verify the negative result. In the time interval before the second test result is available, manifestations of the underlying disease process for the person under investigation, whether due to Ebola virus disease or some other etiology, may require further investigation to direct appropriate therapy. MATERIALS AND METHODS ED administrators, physicians, and nurses proposed processes to provide care that is consistent with other ED patients. Biocontainment unit administrators, industrial hygienists, laboratory directors, physicians, and other medical personnel examined the ED processes and offered biocontainment unit personal protective equipment and process strategies designed to ensure safety for providers and patients. CONCLUSION ED processes for the safe and timely evaluation and management of the person under investigation for Ebola virus disease are presented with the ultimate goals of protecting providers and ensuring a consistent level of care while confirmatory testing is pending.
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Affiliation(s)
- Michael C Wadman
- Department of Emergency Medicine, University of Nebraska Medical Center, Omaha, NE.
| | - Shelly S Schwedhelm
- Emergency Department, Trauma, Emergency Preparedness Services, Nebraska Medicine, Omaha, NE; Nebraska Biocontainment Unit, Nebraska Medicine, Omaha, NE
| | | | - John Swanhorst
- Nebraska Biocontainment Unit, Nebraska Medicine, Omaha, NE; Emergency Services, Nebraska Medicine, Omaha, NE
| | - Shawn G Gibbs
- Department of Environmental, Agricultural, and Occupational Health, College of Public Health, University of Nebraska Medical Center, Omaha, NE; Nebraska Biocontainment Unit, Nebraska Medicine, Omaha, NE
| | - John J Lowe
- Department of Environmental, Agricultural, and Occupational Health, College of Public Health, University of Nebraska Medical Center, Omaha, NE; Nebraska Biocontainment Unit, Nebraska Medicine, Omaha, NE
| | - Peter C Iwen
- Department of Pathology and Microbiology, Nebraska Public Health Laboratory, University of Nebraska Medical Center, Omaha, NE
| | - A Kim Hayes
- Division of Infection Control and Epidemiology, Nebraska Medicine, Omaha, NE
| | | | - Daniel W Johnson
- Department of Anesthesiology, Division of Critical Care, University of Nebraska Medical Center, Omaha, NE
| | - Daniel J Kalin
- Department of Emergency Medicine, University of Nebraska Medical Center, Omaha, NE
| | - Wesley G Zeger
- Department of Emergency Medicine, University of Nebraska Medical Center, Omaha, NE; Nebraska Biocontainment Unit, Nebraska Medicine, Omaha, NE
| | - Robert L Muelleman
- Department of Emergency Medicine, University of Nebraska Medical Center, Omaha, NE
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Smith-Coggins R, Marco CA, Baren JM, Beeson MS, Carius ML, Counselman FL, Heller BN, Kowalenko T, Muelleman RL, Nelson LS, Wahl RP, Korte RC, Joldersma KB. American Board of Emergency Medicine report on residency training information (2014-2015). Ann Emerg Med 2015; 65:584-94. [PMID: 25910762 DOI: 10.1016/j.annemergmed.2015.03.014] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The American Board of Emergency Medicine (ABEM) gathers extensive background information on emergency medicine residency programs and the residents in those programs. We present the 2015 annual report on the status of US emergency medicine training programs.
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Araz OM, Bentley D, Muelleman RL. Using Google Flu Trends data in forecasting influenza-like–illness related ED visits in Omaha, Nebraska. Am J Emerg Med 2014; 32:1016-23. [DOI: 10.1016/j.ajem.2014.05.052] [Citation(s) in RCA: 76] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2014] [Revised: 04/30/2014] [Accepted: 05/31/2014] [Indexed: 11/27/2022] Open
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Smith-Coggins R, Baren JM, Beeson MS, Counselman FL, Kowalenko T, Marco CA, Muelleman RL, Nelson LS, Wahl RP, Korte RC. American Board of Emergency Medicine Report on Residency Training Information (2013-2014), American Board of Emergency Medicine. Ann Emerg Med 2014; 63:637-45. [DOI: 10.1016/j.annemergmed.2014.03.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Stimpson JP, Wilson FA, Muelleman RL. Fatalities of pedestrians, bicycle riders, and motorists due to distracted driving motor vehicle crashes in the U.S., 2005-2010. Public Health Rep 2013; 128:436-42. [PMID: 24179255 PMCID: PMC3804087 DOI: 10.1177/003335491312800603] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
OBJECTIVE Distracted driving is an increasingly deadly threat to road safety. This study documents trends in and characteristics of pedestrian, bicycle rider, and other victim deaths caused by distracted drivers on U.S. public roads. METHODS We obtained data from the Fatality Analysis Reporting System database from 2005 to 2010 on every crash that resulted in at least one fatality within 30 days occurring on public roads in the U.S. Following the definition used by the National Highway Traffic Safety Administration, we identified distracted driving based on whether police investigators determined that a driver had been using a technological device, including a cell phone, onboard navigation system, computer, fax machine, two-way radio, or head-up display, or had been engaged in inattentive or careless activities. RESULTS The rate of fatalities per 10 billion vehicle miles traveled increased from 116.1 in 2005 to 168.6 in 2010 for pedestrians and from 18.7 in 2005 to 24.6 in 2010 for bicyclists. Pedestrian victims of distracted driving crashes were disproportionately male, 25-64 years of age, and non-Hispanic white. They were also more likely to die at nighttime, be struck by a distracted driver outside of a marked crosswalk, and be in a metro location. Bicycling victims of distracted crashes were disproportionately male, non-Hispanic white, and struck by a distracted driver outside of a crosswalk. Compared with pedestrians, bicyclists were less likely to be hit in early morning. CONCLUSIONS Distracted drivers are the cause of an increasing share of fatalities found among pedestrians and bicycle riders. Policies are needed to protect pedestrians and bicycle riders as they cross intersections or travel on roadways.
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Affiliation(s)
- Jim P. Stimpson
- University of Nebraska Medical Center, Department of Health Services Research and Administration, Omaha, NE
| | - Fernando A. Wilson
- University of Nebraska Medical Center, Department of Health Services Research and Administration, Omaha, NE
| | - Robert L. Muelleman
- University of Nebraska Medical Center, Department of Health Services Research and Administration, Omaha, NE
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Zhang D, Liu J, Tu H, Muelleman RL, Cornish KG, Li YL. In vivo transfection of manganese superoxide dismutase gene or nuclear factor κB shRNA in nodose ganglia improves aortic baroreceptor function in heart failure rats. Hypertension 2013; 63:88-95. [PMID: 24101667 DOI: 10.1161/hypertensionaha.113.02057] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Arterial baroreflex sensitivity is attenuated in chronic heart failure (CHF) state, which is associated with cardiac arrhythmias and sudden cardiac death in patients with CHF. Our previous study showed that CHF-induced sodium channel dysfunction in the baroreceptor neurons was involved in the blunted baroreflex sensitivity in CHF rats. Mitochondria-derived superoxide overproduction decreased expression and activation of the sodium channels in the baroreceptor neurons from CHF rats. However, the molecular mechanisms responsible for the sodium channel dysfunction in the baroreceptor neurons from CHF rats remain unknown. We tested the involvement of nuclear factor κB (NFκB) in the sodium channel dysfunction and evaluated the effects of in vivo transfection of manganese superoxide dismutase gene and NFκB shRNA on the baroreflex function in CHF rats. CHF was developed at 6 to 8 weeks after left coronary artery ligation in adult rats. Western blot and chromatin immunoprecipitation data showed that phosphorylated NFκB p65 and ability of NFκB p65 binding to the sodium channel promoter were increased in the nodose ganglia from CHF rats. In vivo transfection of adenoviral manganese superoxide dismutase gene or lentiviral NFκB p65 shRNA into the nodose ganglia partially reversed CHF-reduced sodium channel expression and cell excitability in the baroreceptor neurons and improved CHF-blunted arterial baroreflex sensitivity. Additionally, transfection of adenoviral manganese superoxide dismutase also inhibited the augmentation of phosphorylated NFκB p65 in the nodose neurons from CHF rats. The present study suggests that superoxide-NFκB signaling contributes to CHF-induced baroreceptor dysfunction and resultant impairment of baroreflex function.
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Affiliation(s)
- Dongze Zhang
- Department of Emergency Medicine, University of Nebraska Medical Center, 985850 Nebraska Medical Center, Omaha, NE 68198-5850.
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Tu H, Liu J, Zhang D, Zheng H, Patel KP, Cornish KG, Wang WZ, Muelleman RL, Li YL. Heart failure-induced changes of voltage-gated Ca2+ channels and cell excitability in rat cardiac postganglionic neurons. Am J Physiol Cell Physiol 2013; 306:C132-42. [PMID: 24025863 DOI: 10.1152/ajpcell.00223.2013] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Chronic heart failure (CHF) is characterized by decreased cardiac parasympathetic and increased cardiac sympathetic nerve activity. This autonomic imbalance increases the risk of arrhythmias and sudden death in patients with CHF. We hypothesized that the molecular and cellular alterations of cardiac postganglionic parasympathetic (CPP) neurons located in the intracardiac ganglia and sympathetic (CPS) neurons located in the stellate ganglia (SG) possibly link to the cardiac autonomic imbalance in CHF. Rat CHF was induced by left coronary artery ligation. Single-cell real-time PCR and immunofluorescent data showed that L (Ca(v)1.2 and Ca(v)1.3), P/Q (Ca(v)2.1), N (Ca(v)2.2), and R (Ca(v)2.3) types of Ca2+ channels were expressed in CPP and CPS neurons, but CHF decreased the mRNA and protein expression of only the N-type Ca2+ channels in CPP neurons, and it did not affect mRNA and protein expression of all Ca2+ channel subtypes in the CPS neurons. Patch-clamp recording confirmed that CHF reduced N-type Ca2+ currents and cell excitability in the CPP neurons and enhanced N-type Ca2+ currents and cell excitability in the CPS neurons. N-type Ca2+ channel blocker (1 μM ω-conotoxin GVIA) lowered Ca2+ currents and cell excitability in the CPP and CPS neurons from sham-operated and CHF rats. These results suggest that CHF reduces the N-type Ca2+ channel currents and cell excitability in the CPP neurons and enhances the N-type Ca2+ currents and cell excitability in the CPS neurons, which may contribute to the cardiac autonomic imbalance in CHF.
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Affiliation(s)
- Huiyin Tu
- Department of Emergency Medicine, University of Nebraska Medical Center, Omaha, Nebraska
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Smith-Coggins R, Baren JM, Counselman FL, Kowalenko T, Marco CA, Muelleman RL, Wahl RP, Korte RC. American Board of Emergency Medicine Report on Residency Training Information (2012-2013), American Board of Emergency Medicine. Ann Emerg Med 2013; 61:584-92. [DOI: 10.1016/j.annemergmed.2013.03.019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Zhang D, Tu H, Liu J, Muelleman RL, Yu‐Long L. In‐vivo transfection of manganese SOD gene and NFkB shRNA into nodose ganglia improve blunted baroreflex sensitivity in chronic heart failure rats. FASEB J 2013. [DOI: 10.1096/fasebj.27.1_supplement.699.3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Dongze Zhang
- Department of Emergency MedicineUniversity of Nebraska Medical CenterOmahaNE
| | - Huiyin Tu
- Department of Emergency MedicineUniversity of Nebraska Medical CenterOmahaNE
| | - Jinxu Liu
- Department of Emergency MedicineUniversity of Nebraska Medical CenterOmahaNE
| | - Robert L. Muelleman
- Department of Emergency MedicineUniversity of Nebraska Medical CenterOmahaNE
| | - Li Yu‐Long
- Department of Emergency MedicineUniversity of Nebraska Medical CenterOmahaNE
- Department of cellular and integrative physiologyUniversity of Nebraska Medical CenterOmahaNE
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Wadman MC, Clark TR, Kupas DF, Macht M, McLaughlin S, Mize T, Casaletto J, Muelleman RL. Rural clinical experiences for emergency medicine residents: a curriculum template. Acad Emerg Med 2012; 19:1287-93. [PMID: 23167861 DOI: 10.1111/acem.12007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2012] [Revised: 06/09/2012] [Accepted: 07/11/2012] [Indexed: 11/30/2022]
Abstract
Rural emergency departments (EDs) in the United States are less likely to be staffed with emergency medicine (EM) residency-trained and American Board of Emergency Medicine (ABEM)-certified physicians than urban EDs. Rural EM clinical experiences during residency training have been suggested as a strategy to encourage future rural practice, but past Accreditation Council for Graduate Medical Education (ACGME) Residency Review Committee for Emergency Medicine program requirements and a lack of familiarity with rural rotations in the EM graduate medical education (GME) community have limited their availability. To provide a template for the development and implementation of a rural EM clinical experience, Kern's six-step approach was followed.
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Affiliation(s)
- Michael C. Wadman
- Department of Emergency Medicine; University of Nebraska College of Medicine; Omaha NE
| | - Ted R. Clark
- The Division of Emergency Medicine; Southern Illinois University School of Medicine; Springfield IL
| | - Douglas F. Kupas
- The Department of Emergency Medicine; Geisinger Health System; Danville PA
| | - Marlow Macht
- The Department of Emergency Medicine; University of Colorado School of Medicine; Denver CO
| | - Steve McLaughlin
- The Department of Emergency Medicine; University of New Mexico; School of Medicine; Albuquerque NM
| | - Terry Mize
- The Physician Assistant Program; Emory University School of Medicine; Atlanta GA
| | - Jennifer Casaletto
- The Department of Emergency Medicine; Virginia Tech University-Carilion Clinic; Roanoke VA
| | - Robert L. Muelleman
- Department of Emergency Medicine; University of Nebraska College of Medicine; Omaha NE
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Wadman MC, Lyons WL, Hoffman LH, Muelleman RL. Assessment of a chief complaint-based curriculum for resident education in geriatric emergency medicine. West J Emerg Med 2012; 12:484-8. [PMID: 22224144 PMCID: PMC3236144 DOI: 10.5811/westjem.2010.10.1722] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2009] [Revised: 05/07/2010] [Accepted: 10/18/2010] [Indexed: 11/11/2022] Open
Abstract
INTRODUCTION We hypothesized that a geriatric chief complaint-based didactic curriculum would improve resident documentation of elderly patient care in the emergency department (ED). METHODS A geriatric chief complaint curriculum addressing the 3 most common chief complaints-abdominal pain, weakness, and falls-was developed and presented. A pre- and postcurriculum implementation chart review assessed resident documentation of the 5 components of geriatric ED care: 1) differential diagnosis/patient evaluation considering atypical presentations, 2) determination of baseline function, 3) chronic care facility/caregiver communication, 4) cognitive assessment, and 5) assessment of polypharmacy. A single reviewer assessed 5 pre- and 5 postimplementation charts for each of 18 residents included in the study. We calculated 95% confidence and determined that statistical significance was determined by a 2-tailed z test for 2 proportions, with statistical significance at 0.003 by Bonferroni correction. RESULTS For falls, resident documentation improved significantly for 1 of 5 measures. For abdominal pain, 2 of 5 components improved. For weakness, 3 of 5 components improved. CONCLUSION A geriatric chief complaint-based curriculum improved emergency medicine resident documentation for the care of elderly patients in the ED compared with a non-age-specific chief complaint-based curriculum.
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Affiliation(s)
- Michael C Wadman
- University of Nebraska Medical Center, Department of Emergency Medicine, Omaha, Nebraska
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26
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Tran TP, Tu H, Liu J, Muelleman RL, Li YL. Mitochondria-derived superoxide links to tourniquet-induced apoptosis in mouse skeletal muscle. PLoS One 2012; 7:e43410. [PMID: 22912870 PMCID: PMC3422247 DOI: 10.1371/journal.pone.0043410] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2012] [Accepted: 07/23/2012] [Indexed: 12/12/2022] Open
Abstract
Our previous study has reported that superoxide mediates ischemia-reperfusion (IR)-induced necrosis in mouse skeletal muscle. However, it remains poorly understood whether IR induces apoptosis and what factors are involved in IR-induced apoptosis in skeletal muscle. Using a murine model of tourniquet-induced hindlimb IR, we investigated the relationship between mitochondrial dysfunction and apoptosis in skeletal muscle. Hindlimbs of C57/BL6 mice were subjected to 3 h ischemia and 4 h reperfusion via placement and release of a rubber tourniquet at the greater trochanter. Compared to sham treatment, tourniquet-induced IR significantly elevated mitochondria-derived superoxide production, activated opening of mitochondrial permeability transition pore (mPTP), and caused apoptosis in the gastrocnemius muscles. Pretreatment with a superoxide dismutase mimetic (tempol, 50 mg/kg) or a mitochondrial antioxidant (co-enzyme Q10, 50 mg/kg) not only decreased mitochondria-derived superoxide production, but also inhibited mPTP opening and apoptosis in the IR gastrocnemius muscles. Additionally, an inhibitor of mPTP (cyclosporine A, 50 mg/kg) also inhibited both mPTP opening and apoptosis in the IR gastrocnemius muscles. These results suggest that mitochondria-derived superoxide overproduction triggers the mPTP opening and subsequently causes apoptosis in tourniquet-induced hindlimb IR.
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Affiliation(s)
- Thai P. Tran
- Department of Emergency Medicine, University of Nebraska Medical Center, Omaha, Nebraska, United States
| | - Huiyin Tu
- Department of Emergency Medicine, University of Nebraska Medical Center, Omaha, Nebraska, United States
| | - Jinxu Liu
- Department of Emergency Medicine, University of Nebraska Medical Center, Omaha, Nebraska, United States
| | - Robert L. Muelleman
- Department of Emergency Medicine, University of Nebraska Medical Center, Omaha, Nebraska, United States
| | - Yu-Long Li
- Department of Emergency Medicine, University of Nebraska Medical Center, Omaha, Nebraska, United States
- Department of Cellular and Integrative Physiology, University of Nebraska Medical Center, Omaha, Nebraska, United States
- * E-mail:
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Liu J, Tu H, Zheng H, Zhang L, Tran TP, Muelleman RL, Li YL. Alterations of calcium channels and cell excitability in intracardiac ganglion neurons from type 2 diabetic rats. Am J Physiol Cell Physiol 2011; 302:C1119-27. [PMID: 22189553 DOI: 10.1152/ajpcell.00315.2011] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Clinical study has demonstrated that patients with type 2 diabetes with attenuated arterial baroreflex have higher mortality rate compared with those without arterial baroreflex dysfunction. As a final pathway for the neural control of the cardiac function, functional changes of intracardiac ganglion (ICG) neurons might be involved in the attenuated arterial baroreflex in the type 2 diabetes mellitus (T2DM). Therefore, we measured the ICG neuron excitability and Ca(2+) channels in the sham and T2DM rats. T2DM was induced by a combination of both high-fat diet and low-dose streptozotocin (STZ, 30 mg/kg ip) injection. After 12-14 wk of the above treatment, the T2DM rats presented hyperglycemia, hyperlipidemia, and insulin resistance but no hyperinsulinemia, which closely mimicked the clinical features of the patients with T2DM. Data from immunofluorescence staining showed that L, N, P/Q, and R types of Ca(2+) channels were expressed in the ICG neurons, but only protein expression of N-type Ca(2+) channels was decreased in the ICG neurons from T2DM rats. Using whole cell patch-clamp technique, we found that T2DM significantly reduced the Ca(2+) currents and cell excitability in the ICG neurons. ω-Conotoxin GVIA (a specific N-type Ca(2+) channel blocker, 1 μM) lowered the Ca(2+) currents and cell excitability toward the same level in sham and T2DM rats. These results indicate that the decreased N-type Ca(2+) channels contribute to the suppressed ICG neuron excitability in T2DM rats. From this study, we think high-fat diet/STZ injection-induced T2DM might be an appropriate animal model to test the cellular and molecular mechanisms of cardiovascular autonomic dysfunction.
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Affiliation(s)
- Jinxu Liu
- Department of Emergency Medicine, University of Nebraska Medical Center, Omaha, 68198-5850, USA
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Tu H, Zhang L, Tran TP, Muelleman RL, Li YL. Reduced expression and activation of voltage-gated sodium channels contributes to blunted baroreflex sensitivity in heart failure rats. J Neurosci Res 2011; 88:3337-49. [PMID: 20857502 DOI: 10.1002/jnr.22483] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Voltage-gated sodium (Na(v)) channels are responsible for initiation and propagation of action potential in the neurons. To explore the mechanisms of chronic heart failure (CHF)-induced baroreflex dysfunction, we measured the expression and current density of Na(v) channel subunits (Na(v)1.7, Na(v)1.8, and Na(v)1.9) in the aortic baroreceptor neurons and investigated the role of Na(v) channels in aortic baroreceptor neuron excitability and baroreflex sensitivity in sham and CHF rats. CHF was induced by left coronary artery ligation. The development of CHF (6-8 weeks after the coronary ligation) was confirmed by hemodynamic and morphological characteristics. Immunofluorescent data indicated that Na(v)1.7 was expressed in A-type (myelinated) and C-type (unmyelinated) nodose neurons, but Na(v)1.8 and Na(v)1.9 were expressed only in C-type nodose neurons. Real-time RT-PCR and Western blot data showed that CHF reduced mRNA and protein expression levels of Na(v) channels in nodose neurons. In addition, using the whole-cell patch-clamp technique, we found that Na(v) current density and cell excitability of the aortic baroreceptor neurons were lower in CHF rats than that in sham rats. Aortic baroreflex sensitivity was blunted in anesthetized CHF rats, compared with that in sham rats. Furthermore, Na(v) channel activator (rATX II, 100 nM) significantly enhanced Na(v) current density and cell excitability of aortic baroreceptor neurons and improved aortic baroreflex sensitivity in CHF rats. These results suggest that reduced expression and activation of the Na(v) channels are involved in the attenuation of baroreceptor neuron excitability, which subsequently contributes to the impairment of baroreflex in CHF state.
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Affiliation(s)
- Huiyin Tu
- Department of Emergency Medicine, University of Nebraska Medical Center, Omaha, Nebraska 68198-5850, USA
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Muelleman RL, Sullivan AF, Espinola JA, Ginde AA, Wadman MC, Camargo CA. Distribution of emergency departments according to annual visit volume and urban-rural status: implications for access and staffing. Acad Emerg Med 2010; 17:1390-7. [PMID: 21122024 DOI: 10.1111/j.1553-2712.2010.00924.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
OBJECTIVES ongoing efforts to improve access to emergency care and emergency department (ED) staffing would benefit from a better understanding of the distribution of EDs in the United States by size and location. This article describes the distribution of U.S. ED visit volumes according to ED urban versus rural status. METHODS the authors used the 2007 National Emergency Department Inventories (NEDI)-USA database to identify all nonfederal U.S. hospitals with EDs and their annual ED visit volumes. One of twelve 2003 Urban Influence Codes was applied to each ED location based on its county. These categories were collapsed into urban counties and three types of rural counties: adjacent to urban, large nonadjacent, and small nonadjacent. The number of emergency physicians (EPs) needed to staff the higher-volume rural EDs was estimated. RESULTS of the 4,874 U.S. EDs in 2007, 58% were in urban counties and 42% in rural counties. Among the 2,038 rural EDs, 56% were adjacent to urban, 15% were large nonadjacent, and 29% were small nonadjacent. Of the 1,503 lower-volume (< 10,000 visit) EDs, 21% were in urban counties. Of the 3,371 higher-volume (≥ 10,000 visit) EDs, 25% were in rural counties. Of the 857 higher-volume rural EDs, 66% were adjacent to urban, 22% were large nonadjacent, and 12% were small nonadjacent. The authors estimate that approximately 5,600 EPs are needed to staff these higher-volume rural EDs. CONCLUSIONS there are many lower-volume EDs in urban areas and higher-volume EDs in rural areas. Most higher-volume rural EDs are in rural areas adjacent to urban counties. These data challenge popular assumptions regarding ED visit volumes, locations, and staffing needs.
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Affiliation(s)
- Robert L Muelleman
- Departments of Emergency Medicine at University of Nebraska Medical Center, Omaha, NE, USA.
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Schneider SM, Gardner AF, Weiss LD, Wood JP, Ybarra M, Beck DM, Stauffer AR, Wilkerson D, Brabson T, Jennings A, Mitchell M, McGrath RB, Christopher TA, King B, Muelleman RL, Wagner MJ, Char DM, McGee DL, Pilgrim RL, Moskovitz JB, Zinkel AR, Byers M, Briggs WT, Hobgood CD, Kupas DF, Kruger J, Stratford CJ, Jouriles N. The future of emergency medicine. Acad Emerg Med 2010; 17:998-1003. [PMID: 20836784 DOI: 10.1111/j.1553-2712.2010.00854.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Schneider SM, Gardner AF, Weiss LD, Wood JP, Ybarra M, Beck DM, Stauffer AR, Wilkerson D, Brabson T, Jennings A, Mitchell M, McGrath RB, Christopher TA, King B, Muelleman RL, Wagner MJ, Char DM, McGee DL, Pilgrim RL, Moskovitz JB, Zinkel AR, Byers M, Briggs WT, Hobgood CD, Kupas DF, Kruger J, Stratford CJ, Jouriles N. The Future of Emergency Medicine. Ann Emerg Med 2010; 56:178-83. [DOI: 10.1016/j.annemergmed.2010.04.011] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2010] [Revised: 04/14/2010] [Accepted: 03/30/2010] [Indexed: 11/28/2022]
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Schneider SM, Gardner AF, Weiss LD, Wood JP, Ybarra M, Beck DM, Stauffer AR, Wilkerson D, Brabson T, Jennings A, Mitchell M, McGrath RB, Christopher TA, King B, Muelleman RL, Wagner MJ, Char DM, McGee DL, Pilgrim RL, Moskovitz JB, Zinkel AR, Byers M, Briggs WT, Hobgood CD, Kupas DF, Kruger J, Stratford CJ, Jouriles N. The Future of Emergency Medicine. J Emerg Nurs 2010; 36:330-5. [DOI: 10.1016/j.jen.2010.06.013] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Wadman MC, Fago B, Hoffman LH, Tran TP, Muelleman RL. A comparison of emergency medicine resident clinical experience in a rural versus urban emergency department. Rural Remote Health 2010; 10:1442. [PMID: 20509723] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/29/2023] Open
Abstract
INTRODUCTION Strategies for increasing the numbers of American Board of Emergency Medicine certified/emergency medicine (EM) residency trained physicians practicing in rural emergency departments (EDs) include providing rural EM experiences during residency training. However, no studies to date describe the clinical work of EM residents rotating in a rural ED. The objective of the study was to compare the clinical experience of EM residents participating in a rural ED rotation with that on an urban university-based ED rotation. METHODS Second-year EM residents completing both urban and rural clinical ED rotations self-reported the number of patients evaluated, number of patients admitted and admitting bed type, and the number and type of procedures performed over a 6 month period. Total admission rates, telemetry admission rates, and intensive care unit (ICU) admission rates were calculated and compared by z-test for two proportions. Total numbers for central venous access, conscious sedation, dislocation or fracture relocation/reduction endotracheal intubation, laceration repair, lumbar puncture, tube thoracostomy adult medical resuscitation, adult trauma resuscitation, pediatric medical resuscitation, pediatric trauma resuscitation, and the total number of ED hours completed at each clinical site were collected and procedure/resuscitation numbers calculated per 100 resident-hours in the ED. RESULTS Five of six residents completed the patient data forms requested. Patients evaluated per hour in the rural versus urban EDs were 1.22 and 1.21, respectively. Rural versus urban ED total admission rates were 21.74% (95% CI, 28.19.01-24.47) versus 33.35% (31.50-35.20), telemetry admission rates were 3.40% (2.28-4.52) versus 14.24% (12.87-15.61), and ICU admission rates were 0.9% (0.31-1.49) versus 4.38% (3.58-5.18), with the differences in all admission rates determined to be statistically significant. Rural versus urban procedures/100 resident-hours in the ED were 0 versus 0.6 for central venous access (p = 0.087), 0.8 versus 0.3 for conscious sedation (p = 0.170), 1.3 versus 0.2 for dislocation or fracture relocation/reduction (p = 0.001), 0 versus 0.9 for endotracheal intubation (p = 0.026), 6.1 versus 2.7 for laceration repair (p < 0.001), 1.0 versus 1.0 for lumbar puncture (p = 0.845), 0.4 versus 0.2 for tube thoracostomy (p = 0.720), 2.4 versus 3.6 for adult medical resuscitation (p = 0.135), 0.7 versus 2.1 for adult trauma resuscitation (p = 0.023), 0.6 versus 0.3 for pediatric medical resuscitation (p = 0.642), and 0.8 versus 0.2 for pediatric trauma resuscitation (p = 0.034). The higher frequency of endotracheal intubations and adult trauma resuscitations per 100 resident-hours in the urban versus rural EDs was statistically significant by z-test, while laceration repair, dislocation/fracture relocation/reduction, and pediatric trauma resuscitations occurred more frequently in the rural ED by statistically significant margins. No other procedure or resuscitation type differed significantly. CONCLUSION A rural ED rotation provides an active clinical experience, with patients per hour and most procedure frequencies being similar to those at urban sites, but with lower patient acuity as determined by admission rates.
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Affiliation(s)
- Michael C Wadman
- Department of Emergency Medicine, University of Nebraska College of Medicine, Nebraska Medical Center, Omaha, Nebraska 68198-1150, USA.
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Tu H, Zhang L, Tran TP, Muelleman RL, Li Y. Lowered activation of voltage‐gated sodium channels contributes to blunted baroreflex sensitivity in heart failure rats. FASEB J 2010. [DOI: 10.1096/fasebj.24.1_supplement.1051.4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
| | | | | | | | - Yu‐Long Li
- Department of Emergency Medicine
- Cellular & Integrative PhysiologyUniversity of Nebraska Medical CenterOmahaNE
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Zhang L, Zheng H, Tu H, Tran TP, Muelleman RL, Zimmerman MC, Li Y. Elevated angiotensin II attenuates activation of voltage‐gated sodium channels in heart failure rats: involvement of mitochondria‐derived superoxide. FASEB J 2010. [DOI: 10.1096/fasebj.24.1_supplement.1018.5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
| | - Hong Zheng
- Department of Cellular & integrative PhysiologyUniversity of Nebraska Medical CenterOmahaNE
| | | | | | | | - Matthew C. Zimmerman
- Department of Cellular & integrative PhysiologyUniversity of Nebraska Medical CenterOmahaNE
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Tu H, Zhang L, Tran TP, Muelleman RL, Li YL. Diabetes alters protein expression of hyperpolarization-activated cyclic nucleotide-gated channel subunits in rat nodose ganglion cells. Neuroscience 2009; 165:39-52. [PMID: 19815055 DOI: 10.1016/j.neuroscience.2009.10.002] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2009] [Revised: 10/01/2009] [Accepted: 10/02/2009] [Indexed: 10/20/2022]
Abstract
Vagal afferent neurons, serving as the primary afferent limb of the parasympathetic reflex, could be involved in diabetic autonomic neuropathy. Hyperpolarization-activated cyclic nucleotide-gated (HCN) channels are expressed in the vagal afferent neurons and play an important role in determining cell membrane excitation. In the present study, the protein expression and the electrophysiological characteristics of HCN channels were investigated in nodose ganglion (NG) afferent neurons (A-fiber and C-fiber neurons) from sham and streptozotocin (STZ)-induced diabetic rats. In the sham NG, HCN1, HCN3, and HCN4 were expressed in the A-fiber neurons; and HCN2, HCN3, and HCN4 were expressed in the C-fiber neurons. Compared to the sham NG neurons, diabetes induced the expression of HCN2 in the A-fiber neurons besides overexpression of HCN1 and HCN3; and enhanced the expression of HCN2 and HCN3 in C-fiber neurons. In addition, whole-cell patch-clamp data revealed diabetes also increased HCN currents in A-fiber and C-fiber neurons. However, we found that diabetes did not alter the total nodose afferent neuron number and the ratio of A-fiber/C-fiber neurons. These results indicate that diabetes induces the overexpression of HCN channels and the electrophysiological changes of HCN currents in the A- and C-fiber nodose neurons, which might contribute to the diabetes-induced alteration of cell excitability in the vagal afferent neurons.
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Affiliation(s)
- H Tu
- Department of Emergency Medicine, University of Nebraska Medical Center, Omaha, 68198, USA
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Zhang L, Tran TP, Muelleman RL, Li Y. Involvement of NADPH oxidase‐derived superoxide anion in diabetes‐blunted aortic baroreceptor neuron excitability. FASEB J 2009. [DOI: 10.1096/fasebj.23.1_supplement.785.2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Libin Zhang
- Department of Emergency MedicineUniversity of Nebraska Medical CenterOmahaNE
| | - Thai P Tran
- Department of Emergency MedicineUniversity of Nebraska Medical CenterOmahaNE
| | - Robert L Muelleman
- Department of Emergency MedicineUniversity of Nebraska Medical CenterOmahaNE
| | - Yu‐Long Li
- Department of Emergency MedicineUniversity of Nebraska Medical CenterOmahaNE
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Wadman MC, Hoffman LH, Erickson T, Tran TP, Muelleman RL. The impact of a rural emergency department rotation on applicant ranking of a US emergency medicine residency program. Rural Remote Health 2007; 7:686. [PMID: 18047392] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/25/2023] Open
Abstract
INTRODUCTION Few US emergency medicine (EM) residency programs have been located in rural states due to program requirements for emergency department (ED) patient volume. Recent revision to the program requirements now permits 'educationally justifiable exceptions' to the patient population requirement, 'such as clinical sites in a rural setting', and some EM residency programs now plan to offer rural ED clinical experiences as a required curricular component. The impact of a required rural EM rotation on the ranking decisions of applicants is important to residency programs seeking to attract the most desirable applicants. OBJECTIVE To assess the impact of a required rural ED rotation on applicant ranking of an EM residency program in the US National Resident Matching Program (NMRP). METHODS All applicants to the study's EM residency program completing the interview portion of the application process received a mailed and emailed survey following the release of the 2004 NMRP results. The survey included questions addressing the rural/non-rural classification of the location of the applicants' childhood home, medical school, and anticipated future practice. RESULTS Of 46 eligible subjects, 32 (69.6%) completed the survey. Of subjects with a rural childhood, 73.3% reported a positive impact on rank order (95% CI 50.9-95.7%) and 26.7% reported no impact (CI 4.3-49.1%); 81.3% of subjects with non-rural backgrounds reported no impact (CI 62.2-100%), 12.5% higher rank (CI 0-28.7%), and 6.3% lower (CI 0-18.2%). If planning a future practice in a rural community, 83.3% reported positive impact (CI 62.2-100%) and 16.7% no impact (CI 0-37.8%); 78.9% of subjects anticipating future practice in non-rural communities reported no impact (CI 60.6-97.3%), 15.8% higher rank (CI 0-32.2%), and 5.3% lower (CI 0-15.4). Of the subjects attending medical school in rural states, 52.2% reported a positive impact (CI 31.8-72.6%) and 47.8% no impact (CI 27.4-68.2%), while 75% of graduates of medical schools in non-rural states reported no impact (CI 32.6-100%) and 25% (CI 0-67.4%) a negative impact. CONCLUSION The presence of a rural ED rotation did not adversely impact EM residency applicants' ranking of the program.
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Affiliation(s)
- M C Wadman
- Section of Emergency Medicine, University of Nebraska College of Medicine, Nebraska Medical Center, Omaha, Nebraska, USA.
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Muelleman RL, Wadman MC, Tran TP, Ullrich F, Anderson JR. Rural Motor Vehicle Crash Risk of Death is Higher After Controlling for Injury Severity. ACTA ACUST UNITED AC 2007; 62:221-5; discussion 225-6. [PMID: 17215759 DOI: 10.1097/01.ta.0000231696.65548.06] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND Motor vehicle crash (MVC) mortality rates are inversely related to population density. The purpose of this study was to analyze if there is a regional variation in the risk of MVC death after controlling for injury severity. METHODS The study utilized the Crash Outcome Data Evaluation System (CODES) data set in Nebraska. All fatal or injury-related crashes during a 4-year period (1996 through 1999) were analyzed. Injury Severity Scores (ISSs) were calculated from the CODES listed International Classification of Diseases diagnoses. Logistic regression analysis was performed to analyze the odds ratio for death in three rural county groupings compared with urban locations. RESULTS During the 4-year period, 56,727 people were injured and 1,237 were killed in 38,493 MVCs. Of these, 45,222 (78%) records had complete information on variables of interest. In addition, 28,859 (50%) records had enough information to calculate an ISS. A total of 22,181 (39%) records had complete information on the variables of interest and ISSs. After adjusting for the effects of speed limit, age, and alcohol involvement (but not ISS), the odds of death were 1.24 (1.01-1.53) higher in the large, non-adjacent and 1.38 (1.14-1.66) small, non-adjacent rural counties. After adjusting for the effect of ISS, the odds of death were 1.98 (1.18-3.31) higher in the small, non-adjacent rural counties. CONCLUSION After controlling for ISS, the risk of MVC death is nearly twice as high in the most rural counties in Nebraska. This finding suggests that variation in medical care may contribute to this regional variation.
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Wadman MC, Muelleman RL, Hall D, Tran TP, Walker RA. Qualification discrepancies between urban and rural emergency department physicians. J Emerg Med 2005; 28:273-276. [PMID: 15769567 DOI: 10.1016/j.jemermed.2004.11.020] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2003] [Revised: 10/01/2004] [Accepted: 11/23/2004] [Indexed: 11/20/2022]
Abstract
The purpose of this study was to describe and compare the residency training and board certification credentials of physicians staffing rural and urban emergency departments (EDs) in the predominately rural states of the upper Midwest. EDs in Nebraska, North Dakota, and South Dakota with annual patient volumes greater than 10,000 met inclusion criteria for the study. ED administrators responded to surveys via mail, addressing physician training and board certification status and ED descriptive statistics. Thirty-four EDs met the inclusion criteria for the study with 26 responding (76%). ED physicians reported 50.6% American Board of Emergency Medicine (ABEM) certification and 33.1% residency training in Emergency Medicine (EM). Physicians staffing urban (metropolitan statistical area, MSA) EDs reported ABEM certification and residency training more frequently than those working in rural (non-MSA) EDs (65.2% vs. 30.8% and 48.3% vs. 12.3%, respectively). The results of this study reveal significant discrepancies between urban and rural EDs in physician board certification and residency training.
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Affiliation(s)
- Michael C Wadman
- Section of Emergency Medicine, Department of Surgery, University of Nebraska Medical Center, Omaha, Nebraska
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Abstract
The objective of this study was to determine if a neural network model can identify victims of intimate partner violence (IPV). A custom neural network model was constructed and trained using the 1995 ED databases at Truman Medical Center of all female visits. The input vector developed was an array of 100 binary elements containing, in coded form, the patient's age, day of week, primary diagnosis (excluding 995.81), disposition, race, time, and E-code. The trained network was then presented with a series of 19,830 female patients from the 1996 ED database to determine if it could discriminate cases from control subjects. The neural network identified 231 of 297 known IPV victims (sensitivity 78%) in the 1996 database. It also categorized 2234 false-positive patients out of 19,533 IPV-negative patients (specificity 89%). A computer-based neural network model, when supplied with information commonly available in the ED medical record, can identify victims of IPV.
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Affiliation(s)
- Armand G Sprecher
- Section of Emergency Medicine,University of Nebraska Medical Center, Omaha 68198-1150, USA
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Abstract
STUDY OBJECTIVE Although much is known about injury-related deaths from the use of external cause of injury codes (ecodes) on death certificates, the contribution of nonfatal injury is unknown, with most information based on estimates from national surveys. Some states mandate ecoding of charts for hospitalized patients, but few require ecode assignment for emergency department (ED) records. Missouri and Nebraska mandated ecoding of ED records in 1993 and 1994, respectively, allowing for a more complete description of injuries in those states. We describe fatal and nonfatal injury frequencies in Missouri and Nebraska by using ecodes, with graphic representation in the form of injury pyramids. METHODS Ecode frequencies for 1996 to 1998 for all injury causes in Missouri and Nebraska were reported directly from their respective health departments. The ecode frequencies were grouped according to the Centers for Disease Control and Prevention's ecode matrix for presenting injury and mortality data. RESULTS During the study period, 13,052 deaths, 131,210 hospitalizations, and 1,914,140 ED visits occurred as the result of injury. The most frequent lethal injuries were unintentional motor vehicle crashes (32.3% of total deaths), self-inflicted gunshot wound (13.2%), unintentional falls (11.3%), gunshot wound from an assault (7.7%), and unintentional poisoning (4.3%). The leading causes of injury-related hospitalization were unintentional falls (47.8% of total hospitalizations), unintentional motor vehicle crashes (15.5%), self-inflicted poisoning (6.5%), and overexertion or strenuous movements (2.4%). Of 1.9 million ED injury visits, unintentional falls accounted for 24.3%, unintentionally being struck by an object or person for 14.6%, unintentional motor vehicle crashes for 11.4%, unintentionally being cut or pierced for 10.7%, and overexertion or strenuous movements for 8.5%. CONCLUSION Ecoding in Missouri and Nebraska provides a comprehensive data retrieval system that allows for a graphic depiction of the burden of injury derived from real patient encounters within specific geographic regions.
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Affiliation(s)
- Michael C Wadman
- Department of Surgery, Section of Emergency Medicine, 981150 University of Nebraska Medical Center, Omaha, NE 681198-1150, USA.
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Muelleman RL, DenOtter T, Wadman MC, Tran TP, Anderson J. Problem gambling in the partner of the emergency department patient as a risk factor for intimate partner violence. J Emerg Med 2002; 23:307-12. [PMID: 12426027 DOI: 10.1016/s0736-4679(02)00543-7] [Citation(s) in RCA: 77] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
It has been suggested that the increase in gambling activity nationally has resulted in an increase in intimate partner violence (IPV). There are apparently no studies that have assessed problem gambling as a risk factor for IPV. To determine if problem gambling in the partner is a risk factor for IPV, a cross-sectional study was conducted at a university-based Emergency Department (ED). All women aged 19 to 65 years who presented to the ED for treatment and were not decisionally incapacitated or acutely ill were eligible. Data were collected by a research assistant during 4 or 8-h blocks covering each day of the week over a 10-week period during the months of June through August 1999. There were 300 consecutive women approached, and 286 (95%) agreed to participate. Of the women who agreed to participate, 237 (83%) reported having an intimate partner in the last year, and 61 (25.7%) of these women were categorized as experiencing IPV. The odds ratio (OR) of experiencing IPV was the main outcome measure, estimated using standard logistic regression, given the presence of various personal and partner characteristics, including problem gambling in the partner. The results revealed that the relative odds were elevated for women whose partners were problem gamblers (adjusted OR: 10.5; 95% CI: 1.3-82) or problem drinkers (adjusted OR: 6.1; 95% CI: 2.5-14). The presence of both problem gambling and problem drinking in the partner was associated with an even higher OR (adjusted OR: 50; 95% CI: 9-280). Our study shows that problem gambling in the partner is associated with IPV. The causes of IPV are not fully known, but the association of problem gambling in the partner with IPV could lead to new intervention strategies and Emergency Medicine research in the future.
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Affiliation(s)
- Robert L Muelleman
- Section of Emergency Medicine, University of Nebraska Medical Center, Omaha, Nebraska 68198-1150, USA
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Tran TP, Schutte WP, Muelleman RL, Wadman MC. Provision of clinically based information improves patients' perceived length of stay and satisfaction with EP. Am J Emerg Med 2002; 20:506-9. [PMID: 12369021 DOI: 10.1053/ajem.2002.32652] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
We conducted a focused, prospective, randomized study to evaluate whether periodic personal provision of clinically based information to patients during an Emergency Department (ED) visit improves patients' perceptions of physician's excellence and efficiency of patient care. Six hundred nineteen consecutive adult patients or proxy informants, who were evaluated in the ED and subsequently discharged, were randomized into the standard of care (n = 307) and intervention group (n = 312). Under supervision by ED attending physicians, a single research assistant periodically provided patients with process and medical information at 15-minute intervals, starting at arrival and continuing through until discharged from the ED. At discharge, patients were handed a previously validated questionnaire to fill out and drop off at the ED exit. Outcome measures included actual and patients' estimate of the wait time (WT) and length of stay (LOS), ratings of registration personnel, and ratings of bedside and technical skills of nurses and Emergency Physicians (EPs), by using a 5-point Likert scale (5 = excellent, 4 = very good, 3 = good, 2 = fair, 1 = poor). There were no statistically significant differences in age, sex, insurance data, intensity of service, actual WT, actual LOS, and patients' perceived WT to see a physician between the 2 groups. The perceived LOS was, however, significantly shorter (92.6 vs. 105.5 min, P =.027) and the proportion of patients who rated the Emergency Staff Physician as "excellent" or "very good" was significantly higher in the intervention group (Bedside: 87.1% vs. 80.5%, P =.033; Technical skill: 86.8% vs. 80.1%, P =.032). Patients' perception of nursing skills were, however, statistically similar in the 2 groups (Bedside: 83.1% vs. 83.0%, P =.942; Technical skill: 84.5% vs. 82.7%, P =.613). Given the sample size and observed proportions, the chi(2) analysis of perception of nursing skill had a power of 4.8% (registered nurse [RN] bedside) and 7.5% (RN technical skill). Periodic personal interaction and provision of clinically based information in the ED is thought to improve patients' perceived LOS, efficiency, and clinical skills of EP after an ED visit.
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Affiliation(s)
- T Paul Tran
- Section of Emergency Medicine, Department of Surgery, University of Nebraska School of Medicine, Omaha, NE, USA.
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Abstract
The purpose of this study was to document prior emergency department (ED) use and injuries presented by victims of domestic violence (DV) homicides. We identified all female DV homicide cases investigated by Kansas City, Missouri, Police Department (KCPD) officials over 5 years. Medical Records from 12 hospitals were searched to determine how many homicide victims were in the ED within the 2 years preceding their homicide. The records were reviewed and classified according to the Flitcraft Criteria. KCPD documented 139 female homicides victims, with 34 (24.5%) of these ruled DV-related. Of these 34 victims, 15 (44%) presented to an ED within 2 years of homicide. The 15 subjects made 48 total visits, which included 20 (42%) injury-related visits. Fourteen (93%) of the victims seen in the ED presented with injuries on at least 1 encounter. Eight patients had head injuries (53.3%), 2 had perineal lacerations (13.3%), 2 had rapes (13.3%), and 1 had a suicide attempt (6.7%). The medical records of 8 (53.3%) of the 15 victims yielded at least suggestive evidence of battering. There was documented domestic violence in 2 cases and intervention in none. Because nearly half of all women who were victims of a DV-related homicide had been in the ED within 2 years before their deaths, the ED could play an important role in prevention. Approximately one half had documentation at least suggestive of battering. These results suggest the potential for universal screening, and documented safety assessments.
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Affiliation(s)
- M C Wadman
- Department of Surgery, University of Nebraska Medical Center, Omaha 68198-1150, USA
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Abstract
OBJECTIVE To determine the prevalence and risk factors associated with motor vehicle collisions (MVCs) and near-crashes as reported by emergency medicine (EM) residents following various ED shifts. METHODS A survey was sent to all allopathic EM-2-EM-4 residents in May 1996 asking whether they had ever been involved in an MVC or near-crash while driving home after an ED shift. The residents' night shift schedules, self-reported tolerance of night work, ability to overcome drowsiness, sleep flexibility, and morningness/eveningness tendencies also were collected. RESULTS Seventy-eight programs participated and 62% of 1,554 eligible residents returned usable surveys. Seventy-six (8%, 95% CI = 6% to 10%) residents reported having 96 crashes and 553 (58%, 95% CI = 55% to 61%) residents reported being involved in 1,446 near-crashes. Nearly three fourths of the MVCs and 80% of the near-crashes followed the night shift. Stepwise logistic regression of all variables demonstrated a cumulative association (R = 0.19, p = 0.0004) that accounted for 4% of the observed variability in MVCs and near-crashes. Univariate analysis showed that MVCs and near-crashes were inversely related to residents' shiftwork tolerance (p = 0.019) and positively related to the number of night shifts worked per month (p = 0.035). CONCLUSIONS Residents reported being involved in a higher number of MVCs and near-crashes while driving home after a night shift compared with other shifts. Driving home after a night shift appears to be a significant occupational risk for EM residents.
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Affiliation(s)
- M T Steele
- Department of Emergency Medicine, Truman Medical Center, University of Missouri, Kansas City School of Medicine, 64108, USA.
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47
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Feighny KM, Muelleman RL. The effect of a community-based intimate-partner violence advocacy program in the emergency department on identification rate of intimate-partner violence. Mo Med 1999; 96:242-4. [PMID: 10409835] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/13/2023]
Abstract
A retrospective medical record review assessed identification rate of women acutely injured by intimate-partner violence before and after implementation of an Emergency Department (ED) intimate-partner violence advocacy program. After program implementation, the identification rate of intimate-partner violence increased over 40%. Of the 19 physicians in the ED during both time periods, 17 (89%) identified more cases after the program began (p < 0.003). Implementation of a community-based intimate-partner violence advocacy program in the ED resulted in an increased identification rate of intimate violence.
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48
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Pakieser RA, Lenaghan PA, Muelleman RL. Reflections on written comments by women on their abuse. Nurs Health Sci 1999; 1:139-46. [PMID: 10894662 DOI: 10.1046/j.1442-2018.1999.00018.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
In a study to differentiate injuries of physical abuse from non-physical abuse, 103 women wrote uninvited comments that were analyzed in two ways: Q-sort and phenomenology analyses. Q-sort identified two categories: helplessness and assertiveness. Comparisons with subject responses about current or previous violence indicated that women who wrote assertive comments were less likely to be in a violent relationship than women who wrote helpless comments. Phenomenological analysis indicated that women who were categorized as silent, received or subjective were in abusive relationships; some had been abused on the day of admission. Two women wrote comments considered subjective procedural; both were living with their abuser and stated that the abuse no longer occurred. Health-care professionals must question the appropriate goal to counsel abused women. Whether these two continua reflect a readiness to leave the relationship or result from having left, the comments by two women who say they are no longer being abused are more assertive and appear to show higher levels of knowing.
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Affiliation(s)
- R A Pakieser
- School of Nursing, University of Texas Health Science Center, San Antonio 78284-7963, USA.
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Abstract
STUDY OBJECTIVE The emergency department is often accessed by battered women. Although it is recommended that information about community resources be given to women, there is little information regarding how often women use these resources. The objective of this study was to determine whether an ED-based advocacy program resulted in increased community resource utilization by battered women. METHODS The study used a before-after trial design at an urban county hospital ED. Before the program, a consecutive sample of 117 women was identified in the ED as having sustained injuries by domestic violence. After the program, a consecutive sample of 105 (57% of the 183 asked) who agreed to meet with an advocate in the ED was identified. Participants in both groups lived in Kansas City, Missouri, and were 18 years of age or older. The outcome measures were the proportion of women with shelter use, shelter-based counseling, police calls, full orders of protection, and repeat ED visits for domestic violence after the index ED visit. RESULTS After the initiation of the program, shelter use increased from 11% to 28% (P =.003) and shelter-based counseling increased from 1% to 15% (P <.001). There was no change in repeat police calls (25% versus 35%, P =.14), full orders of protection (9% versus 6%, P =. 58), or repeat ED visits for domestic violence (11% versus 8%, P =. 63). CONCLUSION ED-based advocacy for domestic violence resulted in increased use of shelters and shelter-based counseling.
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Affiliation(s)
- R L Muelleman
- Emergency Medicine Department, University of Missouri-Kansas City School of Medicine, USA.
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Steele MT, Tran LV, Watson WA, Muelleman RL. Retained glass foreign bodies in wounds: predictive value of wound characteristics, patient perception, and wound exploration. Am J Emerg Med 1998; 16:627-30. [PMID: 9827733 DOI: 10.1016/s0735-6757(98)90161-9] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
A convenience sample of 164 adult patients with 185 glass-caused wounds who presented to an emergency department (ED) and consented to a radiograph was prospectively studied. The purpose was to determine the characteristics of wounds at high risk for foreign body (FB) and the predictive value of patient FB sensation and probing wound exploration for FB retention. Retained glass was located in 28 (15%) wounds. Motor vehicle as a mechanism of injury (P=.003), head as a location (P=.035), and puncture as wound type (P=.002) were more likely to be associated with retained FBs (chi2 analysis). Patients with wounds with glass were more likely to have a positive perception of a foreign body (41%) than those with no glass (17%) (P=.005). The positive predictive value of patient perception was 31%; negative predictive value was 89%. In five cases, wound exploration was negative and subsequent radiograph was positive for FB. In one of these cases, a 4-mm glass FB was removed; in the other four, no FB was found. In conclusion, head wounds resulting from motor vehicle accidents or puncture wounds are more likely to harbor retained glass FBs. Patients with glass FB in wounds are more likely to have a positive perception of FB; however, a positive perception has a low predictive value of glass FB. In this series, a negative wound exploration made the presence of retained FB greater than 2 mm less likely but did not rule out the presence of retained glass.
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Affiliation(s)
- M T Steele
- Department of Emergency Medicine, Truman Medical Center, University of Missouri-Kansas City School of Medicine, 64108, USA
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