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1.
BMC Bioinformatics ; 22(1): 170, 2021 Mar 31.
Article in English | MEDLINE | ID: mdl-33789571

ABSTRACT

BACKGROUND: The most common measure of association between two continuous variables is the Pearson correlation (Maronna et al. in Safari an OMC. Robust statistics, 2019. https://login.proxy.bib.uottawa.ca/login?url=https://learning.oreilly.com/library/view/-/9781119214687/?ar&orpq&email=^u). When outliers are present, Pearson does not accurately measure association and robust measures are needed. This article introduces three new robust measures of correlation: Taba (T), TabWil (TW), and TabWil rank (TWR). The correlation estimators T and TW measure a linear association between two continuous or ordinal variables; whereas TWR measures a monotonic association. The robustness of these proposed measures in comparison with Pearson (P), Spearman (S), Quadrant (Q), Median (M), and Minimum Covariance Determinant (MCD) are examined through simulation. Taba distance is used to analyze genes, and statistical tests were used to identify those genes most significantly associated with Williams Syndrome (WS). RESULTS: Based on the root mean square error (RMSE) and bias, the three proposed correlation measures are highly competitive when compared to classical measures such as P and S as well as robust measures such as Q, M, and MCD. Our findings indicate TBL2 was the most significant gene among patients diagnosed with WS and had the most significant reduction in gene expression level when compared with control (P value = 6.37E-05). CONCLUSIONS: Overall, when the distribution is bivariate Log-Normal or bivariate Weibull, TWR performs best in terms of bias and T performs best with respect to RMSE. Under the Normal distribution, MCD performs well with respect to bias and RMSE; but TW, TWR, T, S, and P correlations were in close proximity. The identification of TBL2 may serve as a diagnostic tool for WS patients. A Taba R package has been developed and is available for use to perform all necessary computations for the proposed methods.


Subject(s)
Correlation of Data , Computer Simulation , Humans
2.
Arch Phys Med Rehabil ; 99(2): 289-298, 2018 02.
Article in English | MEDLINE | ID: mdl-28899825

ABSTRACT

OBJECTIVE: To quantify the long-term (>2y) effects of lower extremity (LE) neuroprostheses (NPs) for standing, transfers, stepping, and seated stability after spinal cord injury. DESIGN: Single-subject design case series with participants acting as their own concurrent controls, including retrospective data review. SETTING: Hospital-based clinical biomechanics laboratory with experienced (>20y in the field) research biomedical engineers, a physical therapist, and medical monitoring review. PARTICIPANTS: Long-term (6.2±2.7y) at-home users (N=22; 19 men, 3 women) of implanted NPs for trunk and LE function with chronic (14.4±7.1y) spinal cord injury resulting in full or partial paralysis. INTERVENTIONS: Technical and clinical performance measurements, along with user satisfaction surveys. MAIN OUTCOME MEASURES: Knee extension moment, maximum standing time, body weight supported by lower extremities, 3 functional standing tasks, 2 satisfaction surveys, NP usage, and stability of implanted components. RESULTS: Stimulated knee extension strength and functional capabilities were maintained, with 94% of implant recipients reporting being very or moderately satisfied with their system. More than half (60%) of the participants were still using their implanted NPs for exercise and function for >10min/d on nearly half or more of the days monitored; however, maximum standing times and percentage body weight through LEs decreased slightly over the follow-up interval. Stimulus thresholds were uniformly stable. Six-year survival rates for the first-generation implanted pulse generator (IPG) and epimysial electrodes were close to 90%, whereas those for the second-generation IPG along with the intramuscular and nerve cuff electrodes were >98%. CONCLUSIONS: Objective and subjective measures of the technical and clinical performances of implanted LE NPs generally remained consistent for 22 participants after an average of 6 years of unsupervised use at home. These findings suggest that implanted LE NPs can provide lasting benefits that recipients value.


Subject(s)
Lower Extremity/physiopathology , Neural Prostheses , Paraplegia/physiopathology , Paraplegia/rehabilitation , Patient Satisfaction , Posture/physiology , Spinal Cord Injuries/physiopathology , Activities of Daily Living , Adult , Biomechanical Phenomena , Female , Follow-Up Studies , Humans , Male , Middle Aged , Retrospective Studies , Surveys and Questionnaires , Treatment Outcome
4.
Pediatr Emerg Care ; 31(9): 670-3, 2015 Sep.
Article in English | MEDLINE | ID: mdl-26335234

ABSTRACT

Skin and soft tissue infections are common disease presentations to the pediatric emergency department, and rapid and accurate identification of potentially serious skin and soft tissue infections is critical. In cases of atraumatic musculoskeletal pain with systemic complaints, a bacterial etiology must be ruled out. Point-of-care ultrasonography is increasingly common in the pediatric emergency department and assists in rapid and accurate identification of a variety of disease processes. We present a case of a 14-year-old adolescent boy with atraumatic right knee pain to illustrate the benefits of point-of-care ultrasonography in the timely diagnosis of musculoskeletal and soft tissue pathology. Moreover, we describe the use of ultrasound in procedural guidance of deep-space fluid aspiration, with an eventual diagnosis of femoral osteomyelitis. Ultrasonographic techniques and the emergent work-up and management of osteomyelitis are reviewed.


Subject(s)
Abscess/diagnostic imaging , Osteomyelitis/diagnostic imaging , Abscess/microbiology , Adolescent , Humans , Magnetic Resonance Imaging/methods , Male , Osteomyelitis/pathology , Osteomyelitis/surgery , Point-of-Care Systems , Staphylococcus aureus/isolation & purification , Ultrasonography, Interventional/methods
5.
J Community Health ; 39(5): 943-50, 2014 Oct.
Article in English | MEDLINE | ID: mdl-24554393

ABSTRACT

This study examined demographic and lifestyle factors that influenced decisions and obstacles to being screened for breast cancer in low-income African Americans in three urban Tennessee cities. As part of the Meharry Community Networks Program (CNP) needs assessment, a 123-item community survey was administered to assess demographic characteristics, health care access and utilization, and screening practices for various cancers in low-income African Americans. For this study, only African American women 40 years and older (n = 334) were selected from the Meharry CNP community survey database. There were several predictors of breast cancer screening such as marital status and having health insurance (P < .05). Additionally, there were associations between obstacles to screening and geographic region such as transportation and not having enough information about screenings (P < .05). Educational interventions aimed at improving breast cancer knowledge and screening rates should incorporate information about obstacles and predictors to screening.


Subject(s)
Black or African American/statistics & numerical data , Breast Neoplasms/diagnosis , Early Detection of Cancer/statistics & numerical data , Mammography/statistics & numerical data , Poverty/statistics & numerical data , Adult , Age Factors , Aged , Female , Humans , Middle Aged , Socioeconomic Factors , Tennessee/epidemiology
6.
Pediatr Emerg Care ; 30(11): 839-44, 2014 Nov.
Article in English | MEDLINE | ID: mdl-25373574

ABSTRACT

Although pulmonary embolism in children is rare, it is important for the pediatric emergency medicine provider to be aware of its presentation and emergent management. We present a case of bilateral pulmonary embolisms in an adolescent patient to illustrate the benefits from the timely diagnosis of right ventricular dysfunction by point-of-care echocardiography performed by emergency medicine physicians. Ultrasonographic techniques and the emergent management of pulmonary embolism are reviewed.


Subject(s)
Echocardiography , Point-of-Care Systems , Pulmonary Embolism/diagnostic imaging , Adolescent , Emergencies , Emergency Service, Hospital , Female , Humans
8.
Arch Phys Med Rehabil ; 94(9): 1766-75, 2013 Sep.
Article in English | MEDLINE | ID: mdl-23500182

ABSTRACT

OBJECTIVE: To determine the stimulated strength of the paralyzed gluteal and paraspinal muscles and their effects on the seated function of individuals with paralysis. DESIGN: Case series with subjects acting as their own concurrent controls. SETTING: Hospital-based clinical biomechanics laboratory. PARTICIPANTS: Users (N=8) of implanted neuroprostheses for lower extremity function with low-cervical or thoracic level injuries. INTERVENTIONS: Dynamometry and digital motion capture both with and without stimulation to the hip and trunk muscles. MAIN OUTCOME MEASURES: Isometric trunk extension moment at 0°, 15°, and 30° of flexion; seated stability in terms of simulated isokinetic rowing; pelvic tilt, shoulder height, loaded and unloaded bimanual reaching to different heights, and subjective ratings of difficulty during unsupported sitting. RESULTS: Stimulation produced significant increases in mean trunk extension moment (9.2±9.5Nm, P<.001) and rowing force (27.4±23.1N, P<.012) over baseline volitional values. Similarly, stimulation induced positive changes in average pelvic tilt (16.7±15.7°) and shoulder height (2.2±2.5cm) during quiet sitting and bimanual reaching, and increased mean reach distance (5.5±6.6cm) over all subjects, target heights, and loading conditions. Subjects consistently rated tasks with stimulation easier than voluntary effort alone. CONCLUSIONS: In spite of considerable intersubject variability, stabilizing the paralyzed trunk with electrical stimulation can positively impact seated posture, extend forward reach, and allow exertion of larger forces on objects in the environment.


Subject(s)
Electric Stimulation Therapy/methods , Hip , Muscle, Skeletal/physiopathology , Spinal Cord Injuries/rehabilitation , Torso , Biomechanical Phenomena , Female , Humans , Male , Muscle Strength Dynamometer , Posture
9.
Arch Phys Med Rehabil ; 94(10): 1997-2005, 2013 Oct.
Article in English | MEDLINE | ID: mdl-23628377

ABSTRACT

OBJECTIVE: To quantify the effects of stabilizing the paralyzed trunk and pelvis with electrical stimulation on manual wheelchair propulsion. DESIGN: Single-subject design case series with subjects acting as their own concurrent controls. SETTING: Hospital-based clinical biomechanics laboratory. PARTICIPANTS: Individuals (N=6; 4 men, 2 women; mean age ± SD, 46 ± 10.8y) who were long-time users (6.1 ± 3.9y) of implanted neuroprostheses for lower extremity function and had chronic (8.6 ± 2.8y) midcervical- or thoracic-level injuries (C6-T10). INTERVENTIONS: Continuous low-level stimulation to the hip (gluteus maximus, posterior adductor, or hamstrings) and trunk extensor (lumbar erector spinae and/or quadratus lumborum) muscles with implanted intramuscular electrodes. MAIN OUTCOME MEASURES: Pushrim kinetics (peak resultant force, fraction effective force), kinematics (cadence, stroke length, maximum forward lean), and peak shoulder moment at preferred speed over 10-m level surface; speed, pushrim kinetics, and subjective ratings of effort for level 100-m sprints and up a 30.5-m ramp of approximately 5% grade. RESULTS: Three of 5 subjects demonstrated reduced peak resultant pushrim forces (P≤.014) and improved efficiency (P≤.048) with stimulation during self-paced level propulsion. Peak sagittal shoulder moment remained unchanged in 3 subjects and increased in 2 others (P<.001). Maximal forward trunk lean also increased by 19% to 26% (P<.001) with stimulation in these 3 subjects. Stroke lengths were unchanged by stimulation in all subjects, and 2 showed extremely small (5%) but statistically significant increases in cadence (P≤.021). Performance measures for sprints and inclines were generally unchanged with stimulation; however, subjects consistently rated propulsion with stimulation to be easier for both surfaces. CONCLUSIONS: Stabilizing the pelvis and trunk with low levels of continuous electrical stimulation to the lumbar trunk and hip extensors can positively impact the mechanics of manual wheelchair propulsion and reduce both perceived and physical measures of effort.


Subject(s)
Electric Stimulation Therapy/methods , Spinal Cord Injuries/rehabilitation , Wheelchairs , Adult , Biomechanical Phenomena , Female , Hip/physiopathology , Humans , Lumbosacral Region/physiopathology , Male , Middle Aged , Shoulder/physiopathology , Torso/physiopathology
10.
Gerontologist ; 63(7): 1211-1227, 2023 08 24.
Article in English | MEDLINE | ID: mdl-35793531

ABSTRACT

BACKGROUND AND OBJECTIVES: Older adults (≥65 years) are living longer with complex health needs and wish to remain at home as their care needs change. We aimed to determine which factors influence older persons' transitions from home living to facility-based care (FBC) settings such as long-term care facilities or assisted living. RESEARCH DESIGN AND METHODS: Through a scoping review of 7 databases, we considered all academic literature examining factors influencing transitions from home living to FBC. Only English articles were reviewed. Based on the Meleis' Health Transition (MHT) model, we categorized findings into: (a) transition conditions; (b) patterns of response; and (c) health services and interventions. RESULTS: We included 204 unique studies. Age, cognitive/functional impairments, and caregiver burden were the most consistent risk factors for older persons' transitions to FBC. Caregiver burden was the only consistent risk factor in both quantitative and qualitative literature. Other factors around health service use or nonmedical factors were examined in a small number of studies, or demonstrated mixed or nonsignificant results. Key research gaps relate to transitions to intermediate levels of FBC, research in public health systems, and research employing qualitative and interventional methods. DISCUSSION AND IMPLICATIONS: We expanded the MHT model to capture informal caregivers and their critical role in transitions from home to FBC settings. More research is needed to address practical needs of clients and caregivers while at home, and self-directed care funding models could be expanded. Theory-driven interventional research focusing on caregivers and successful hospital discharge is critically needed.


Subject(s)
Caregivers , Patient Discharge , Humans , Aged , Aged, 80 and over , Skilled Nursing Facilities , Self Care
11.
Pract Radiat Oncol ; 13(2): 97-111, 2023.
Article in English | MEDLINE | ID: mdl-36585312

ABSTRACT

PURPOSE: This updated report on image guided radiation therapy (IGRT) is part of a series of consensus-based white papers previously published by the American Society for Radiation Oncology addressing patient safety. Since the first white papers were published, IGRT technology and procedures have progressed significantly such that these procedures are now more commonly used. The use of IGRT has now extended beyond high-precision treatments, such as stereotactic radiosurgery and stereotactic body radiation therapy, and into routine clinical practice for many treatment techniques and anatomic sites. Therefore, quality and patient safety considerations for these techniques remain an important area of focus. METHODS AND MATERIALS: The American Society for Radiation Oncology convened an interdisciplinary task force to assess the original IGRT white paper and update content where appropriate. Recommendations were created using a consensus-building methodology, and task force members indicated their level of agreement based on a 5-point Likert scale from "strongly agree" to "strongly disagree." A prespecified threshold of ≥75% of raters who selected "strongly agree" or "agree" indicated consensus. SUMMARY: This IGRT white paper builds on the previous version and uses other guidance documents to primarily focus on processes related to quality and safety. IGRT requires an interdisciplinary team-based approach, staffed by appropriately trained specialists, as well as significant personnel resources, specialized technology, and implementation time. A thorough feasibility analysis of resources is required to achieve the clinical and technical goals and should be discussed with all personnel before undertaking new imaging techniques. A comprehensive quality-assurance program must be developed, using established guidance, to ensure IGRT is performed in a safe and effective manner. As IGRT technologies continue to improve or emerge, existing practice guidelines should be reviewed or updated regularly according to the latest American Association of Physicists in Medicine Task Group reports or guidelines. Patient safety in the application of IGRT is everyone's responsibility, and professional organizations, regulators, vendors, and end-users must demonstrate a clear commitment to working together to ensure the highest levels of safety.


Subject(s)
Radiosurgery , Radiotherapy, Image-Guided , Humans , Radiotherapy, Image-Guided/methods , Patient Safety
12.
Arch Phys Med Rehabil ; 93(5): 896-904, 2012 May.
Article in English | MEDLINE | ID: mdl-22541312

ABSTRACT

OBJECTIVE: To investigate the longitudinal performance of a surgically implanted neuroprosthesis for lower-extremity exercise, standing, and transfers after spinal cord injury. DESIGN: Case series. SETTING: Research or outpatient physical therapy departments of 4 academic hospitals. PARTICIPANTS: Subjects (N=15) with thoracic or low cervical level spinal cord injuries who had received the 8-channel neuroprosthesis for exercise and standing. INTERVENTION: After completing rehabilitation with the device, the subjects were discharged to unrestricted home use of the system. A series of assessments were performed before discharge and at a follow-up appointment approximately 1 year later. MAIN OUTCOME MEASURES: Neuroprosthesis usage, maximum standing time, body weight support, knee strength, knee fatigue index, electrode stability, and component survivability. RESULTS: Levels of maximum standing time, body weight support, knee strength, and knee fatigue index were not statistically different from discharge to follow-up (P>.05). Additionally, neuroprosthesis usage was consistent with subjects choosing to use the system on approximately half of the days during each monitoring period. Although the number of hours using the neuroprosthesis remained constant, subjects shifted their usage to more functional standing versus more maintenance exercise, suggesting that the subjects incorporated the neuroprosthesis into their lives. Safety and reliability of the system were demonstrated by electrode stability and a high component survivability rate (>90%). CONCLUSIONS: This group of 15 subjects is the largest cohort of implanted lower-extremity neuroprosthetic exercise and standing system users. The safety and efficiency data from this group, and acceptance of the neuroprosthesis as demonstrated by continued usage, indicate that future efforts toward commercialization of a similar device may be warranted.


Subject(s)
Knee/physiology , Neural Prostheses , Patient Acceptance of Health Care , Spinal Cord Injuries/physiopathology , Cervical Vertebrae , Female , Humans , Kaplan-Meier Estimate , Longitudinal Studies , Lower Extremity/physiopathology , Male , Muscle Fatigue , Muscle Strength , Neural Prostheses/adverse effects , Prosthesis Failure , Prosthesis Implantation , Spinal Cord Injuries/rehabilitation , Spinal Cord Injuries/surgery , Thoracic Vertebrae , Time Factors , Weight-Bearing/physiology
13.
Mil Med ; 177(8): 911-6, 2012 Aug.
Article in English | MEDLINE | ID: mdl-22934369

ABSTRACT

Hemorrhagic shock is a primary injury amongst combat casualties. Aeromedical evacuation (AE) of casualties exposes patients to a hypobaric, hypoxic environment. The effect of this environment on the host response to hemorrhagic shock is unknown. In the present study, we sought to determine the effect of simulated AE on systemic inflammation and organ injury using a murine model of hemorrhagic shock. Mice underwent femoral artery cannulation and were hemorrhaged for 60 minutes. Mice were then resuscitated with a 1:1 ratio of plasma:packed red blood cells. At 1 or 24 hours after resuscitation, mice were exposed to a 5-hour simulated AE or remained at ground level (control). Serum was analyzed for cytokine concentrations and organs were assessed for neutrophil accumulation and vascular permeability. Mice in the simulated AE groups demonstrated reduced arterial oxygen saturation compared to ground controls. Serum cytokine concentrations, neutrophil recruitment, and vascular permeability in the lung, ileum, and colon in the simulated AE groups were not different from the ground controls. Our results demonstrate that mice exposed to simulated AE following hemorrhagic shock do not exhibit worsened systemic inflammation or organ injury compared to controls. The data suggest that AE has no adverse effect on isolated hemorrhagic shock.


Subject(s)
Air Ambulances , Shock, Hemorrhagic , Animals , Capillary Permeability , Colon/metabolism , Cytokines/blood , Disease Models, Animal , Ileum/metabolism , Lung/metabolism , Mice , Mice, Inbred C57BL , Neutrophils/metabolism , Shock, Hemorrhagic/blood , Shock, Hemorrhagic/metabolism
14.
Adm Policy Ment Health ; 39(6): 466-77, 2012 Nov.
Article in English | MEDLINE | ID: mdl-21861204

ABSTRACT

The objective was to demonstrate decision-analytic modeling in support of Child Welfare policymakers considering implementing evidence-based interventions. Outcomes included permanency (e.g., adoptions) and stability (e.g., foster placement changes). Analyses of a randomized trial of KEEP-a foster parenting intervention-and NSCAW-1 estimated placement change rates and KEEP's effects. A microsimulation model generalized these findings to other Child Welfare systems. The model projected that KEEP could increase permanency and stability, identifying strategies targeting higher-risk children and geographical regions that achieve benefits efficiently. Decision-analytic models enable planners to gauge the value of potential implementations.


Subject(s)
Child Welfare/statistics & numerical data , Decision Support Techniques , Foster Home Care/statistics & numerical data , Public Policy , Adolescent , Adoption , California , Child , Child, Preschool , Computer Simulation , Evidence-Based Practice/statistics & numerical data , Humans , Infant , Randomized Controlled Trials as Topic
15.
J Am Med Dir Assoc ; 23(1): 133-140.e3, 2022 01.
Article in English | MEDLINE | ID: mdl-34293327

ABSTRACT

OBJECTIVES: People are living longer with complex health needs and wish to remain in their homes as their care needs change. We examined which client factors (sociodemographic, health service use, health, and function) influenced older persons' (≥65 years) time to transition from home living to assisted living (AL) or long-term care (LTC) facilities. DESIGN: Retrospective cohort study. SETTING AND PARTICIPANTS: Long-term services and supports in Alberta, Canada. Long-stay home care clients (≥65 years) who received a Resident Assessment Instrument-Home Care (RAI-HC) assessment between 2014 and 2018. MEASURES: We assessed time from initial receipt of long-term home care to AL and LTC facility transitions, using Cox proportional hazard regressions, and a provincial continuing care data repository (Alberta Continuing Care Information System). We adjusted for client sociodemographic, health, function, and health service use variables. The outcome was time from initial long-term home care receipt to transition to facility living. RESULTS: We included 33,432 home care clients. Clients who were visited by care aides once in the last 7 days transitioned to AL later than those with no care aide visits [hazard ratio (HR) 0.976, 95% confidence interval (CI) 0.852, 0.964]. Clients receiving physical therapy services once or more a week transitioned to LTC later than those who did not receive these services (HR 0.767, CI 0.672, 0.875). Institutionalizations happened sooner if the client's caregiver was unable to continue (AL: HR 1.335, CI 1.306, 1.365; LTC: HR 1.339, CI 1.245, 1.441) and if clients socialized less (AL: HR 1.149, CI 1.079, 1.223; LTC: HR 1.087, CI 1.018, 1.61). CONCLUSIONS AND IMPLICATIONS: The diverse role of care aides needs to be explored to determine which specific services help to delay AL transitions. Physical therapy exercises that require minimal supervision should be integrated early into care plans to delay LTC transitions. Social/recreational programs to improve older adults' socialization and informal caregiver support could delay transitions.


Subject(s)
Home Care Services , Aged , Aged, 80 and over , Caregivers , Humans , Long-Term Care , Nursing Homes , Retrospective Studies
16.
J Med Eng Technol ; 46(5): 393-401, 2022 Jul.
Article in English | MEDLINE | ID: mdl-35674709

ABSTRACT

Vibration, a potent mechanical stimulus for activating muscle spindle primary afferents, may improve gait performance in persons with multiple sclerosis (MS), but has yet to be developed and deployed for multiple leg muscles with application during walking training. This study explored the development of a cyclic focal muscle vibration (FMV) system, and the deployment feasibility to correct MS walking swing phase deficits in order to determine whether this intervention warrants comprehensive study. The system was deployed during twelve, two-hour sessions of walking with cyclic FMV over six weeks. Participants served as their own control. Blood pressure, heart rate, walking speed, kinematics (peak hip, knee and ankle angles during swing), toe clearance, and step length were measured before and after deployment with blood pressure and heart rate monitored during deployment. During system deployment, there were no untoward sensations and physiological changes in blood pressure and heart rate, and volitional improvements were found in walking speed, improved swing phase kinematics, toe clearance and step length. This FMV training system was developed and deployed to improve joint flexion during walking in those with MS, and it demonstrated feasibility and benefits. Further study will determine the most effective vibration frequency and dose, carryover effects, and those most likely to benefit from this intervention.


Subject(s)
Multiple Sclerosis , Vibration , Biomechanical Phenomena , Gait/physiology , Humans , Muscle, Skeletal/physiology , Walking/physiology
17.
J Surg Res ; 170(2): 272-9, 2011 Oct.
Article in English | MEDLINE | ID: mdl-21529836

ABSTRACT

BACKGROUND: Intestinal injury is a consequence of hemorrhagic shock and resuscitation. The intestinal mucosa has been shown to respond to ischemia/reperfusion injury with production of inflammatory mediators. Previous work in our laboratory indicates that intestinal epithelial cells secrete proinflammatory cytokines in the direction of both the lamina propria and intestinal lumen. The ability of the intestinal mucosa to transmit inflammatory signals into the gut lumen after hemorrhagic shock is unknown. We hypothesized that hemorrhagic shock results in secretion of proinflammatory cytokines into the gut lumen. METHODS: Male C57/Bl6 mice underwent femoral artery cannulation and hemorrhage to a systolic blood pressure of 20 mmHg for 1 h, then resuscitation with lactated Ringer's (LR) solution. Sham animals were cannulated only. Mice were decannulated and sacrificed at intervals. Stool and succus were removed from intestinal segments, weighed, and placed into buffer solution. Specimens were analyzed via enzyme-linked immunosorbent assay (ELISA). RESULTS: Compared with sham-injured mice, hemorrhagic shock resulted in increased intestinal luminal cytokines. At 3 h after injury, elevated levels of IL-6 were found in the cecal stool. At 6 h after injury, TNFα, IL-6, and MIP-2 were significantly elevated in the cecal stool, and IL-6 and MIP-2 were significantly elevated in the distal colonic stool. CONCLUSIONS: Hemorrhagic shock results in secretion of proinflammatory cytokines into the intestinal lumen. These findings suggest that the intestinal mucosa may transmit and receive signals in a paracrine fashion via the gut lumen.


Subject(s)
Cytokines/metabolism , Enteritis/immunology , Intestinal Mucosa/immunology , Shock, Hemorrhagic/immunology , Animals , Blood Pressure/immunology , Blood Volume/immunology , Chemokine CXCL2/metabolism , Feces , Interleukin-6/metabolism , Intestinal Mucosa/metabolism , Male , Mice , Mice, Inbred C57BL , Paracrine Communication/immunology , Resuscitation , Tumor Necrosis Factor-alpha/metabolism
18.
J Surg Res ; 165(1): 30-7, 2011 Jan.
Article in English | MEDLINE | ID: mdl-20850781

ABSTRACT

OBJECTIVE: To determine the inflammatory effects of time-dependent exposure to the hypobaric environment of simulated aeromedical evacuation following traumatic brain injury (TBI). METHODS: Mice were subjected to a blunt TBI or sham injury. Righting reflex response (RRR) time was assessed as an indicator of neurologic recovery. Three or 24 h (Early and Delayed groups, respectively) after TBI, mice were exposed to hypobaric flight conditions (Fly) or ground-level control (No Fly) for 5 h. Arterial blood gas samples were obtained from all groups during simulated flight. Serum and cortical brain samples were analyzed for inflammatory cytokines after flight. Neuron specific enolase (NSE) was measured as a serum biomarker of TBI severity. RESULTS: TBI resulted in prolonged RRR time compared with sham injury. After TBI alone, serum levels of interleukin-6 (IL-6) and keratinocyte-derived chemokine (KC) were increased by 6 h post-injury. Simulated flight significantly reduced arterial oxygen saturation levels in the Fly group. Post-injury altitude exposure increased cerebral levels of IL-6 and macrophage inflammatory protein-1α (MIP-1α), as well as serum NSE in the Early but not Delayed Flight group compared to ground-level controls. CONCLUSIONS: The hypobaric environment of aeromedical evacuation results in significant hypoxia. Early, but not delayed, exposure to a hypobaric environment following TBI increases the neuroinflammatory response to injury and the severity of secondary brain injury. Optimization of the post-injury time to fly using serum cytokine and biomarker levels may reduce the potential secondary cerebral injury induced by aeromedical evacuation.


Subject(s)
Brain Injuries/immunology , Hypoxia/complications , Inflammation/etiology , Animals , Chemokine CCL3/blood , Interleukin-6/blood , Male , Mice , Mice, Inbred C57BL , Phosphopyruvate Hydratase/blood , Reflex, Righting
19.
Am J Phys Med Rehabil ; 100(10): 983-989, 2021 10 01.
Article in English | MEDLINE | ID: mdl-33443856

ABSTRACT

OBJECTIVE: The aims of the study were to reliably determine the two main phases of manual wheelchair propulsion via a simple wearable sensor and to evaluate the effects of modulated trunk and hip stimulation on manual wheelchair propulsion during the challenging tasks of ramp assent and level sprint. DESIGN: An offline tool was created to identify common features between wrist acceleration signals for all subjects who corresponded to the transitions between the contact and recovery phases of manual wheelchair propulsion. For one individual, the acceleration rules and thresholds were implemented for real-time phase-change event detection and modulation of stimulation. RESULTS: When pushing with phase-dependent modulated stimulation, there was a significant (P < 0.05) increase in the primary speed variable (5%-6%) and the subject rated pushing as "moderately or very easy." In the offline analysis, the average phase-change event detection success rate was 79% at the end of contact and 71% at the end of recovery across the group. CONCLUSIONS: Signals from simple, wrist-mounted accelerometers can detect the phase transitions during manual wheelchair propulsion instead of elaborate and expensive, instrumented systems. Appropriately timing changes in muscle activation with the propulsion cycle can result in a significant increase in speed, and the system was consistently perceived to be significantly easier to use.


Subject(s)
Disabled Persons/rehabilitation , Muscle, Skeletal/physiology , Torso/physiology , Wheelchairs , Accelerometry , Biomechanical Phenomena , Female , Humans , Male , Wearable Electronic Devices
20.
J Surg Res ; 160(2): 190-5, 2010 May 15.
Article in English | MEDLINE | ID: mdl-20031163

ABSTRACT

BACKGROUND: Patients suffering from burn injury are at high risk for subsequent infection. Thermal injury followed by endotoxemia may result in a "second hit," causing an exaggerated inflammatory response with increased morbidity and mortality. The role of the intestine in this "second hit" response is unknown. We hypothesized that remote thermal injury increases the inflammatory response of intestinal mucosa to subsequent treatment with lipopolysaccharide (LPS). METHODS: Mice underwent sham or scald injury. Seven days after injury, mice were treated with LPS. Blood and bowel specimens were obtained. Serum and intestinal inflammatory cytokines were measured by enzyme-linked immunosorbent assay (ELISA). Changes in TLR-4 pathway components in intestine were measured by reverse transcription-polymerase chain reaction (RT-PCR), Western blot, and electrophoretic mobility shift assay (EMSA). Intestinal leukocyte infiltration was analyzed by myeloperoxidase assay. RESULTS: A "second hit" of injected LPS resulted in increased IL-6 in intestine of burned mice compared with sham. Similarly, jejunal IL-6 mRNA levels increased in mice with prior thermal injury, suggesting a transcriptional mechanism. Of transcription factors known to drive IL-6 expression, only AP-1 activation was significantly elevated by a "second hit" of LPS. CONCLUSION: Prior thermal injury potentiates LPS-induced IL-6 cytokine production in intestine. These results indicate a heightened inflammatory response to a second hit by intestine after burn injury.


Subject(s)
Burns/immunology , Inflammation/immunology , Interleukin-6/genetics , Interleukin-6/metabolism , Intestinal Mucosa/immunology , Intestinal Mucosa/metabolism , Lipopolysaccharides/pharmacology , Animals , Burns/physiopathology , CCAAT-Enhancer-Binding Proteins/metabolism , Colon/drug effects , Colon/immunology , Inflammation/physiopathology , Intestinal Mucosa/drug effects , Jejunum/drug effects , Jejunum/immunology , Male , Mice , Mice, Inbred C57BL , NF-kappa B/metabolism , RNA, Messenger/metabolism , Signal Transduction/drug effects , Signal Transduction/immunology , Toll-Like Receptor 4/metabolism , Transcription Factor AP-1/metabolism , Transcriptional Activation/physiology
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