Accelerometer-based prediction of running injury in National Collegiate Athletic Association track athletes

Running-related injuries (RRI) may result from accumulated microtrauma caused by combinations of high load magnitudes (vertical ground reaction forces; vGRFs) and numbers (strides). Yet relationships between vGRF and RRI remain unclear - potentially because previous research has largely been constrained to collecting vGRFs in laboratory settings and ignoring relationships between RRI and stride number. In this preliminary proof-of-concept study, we addressed these constraints: Over a 60-day period, each time collegiate athletes (n = 9) ran they wore a hip-mounted activity monitor that collected accelerations throughout the entire run. Accelerations were used to estimate peak vGRF, number of strides, and weighted cumulative loading (sum of peak vGRFs weighted to the 9th power) across the entirety of each run. Runners also reported their post-training pain/fatigue and any RRI that prevented training. Across 419 runs and >2.1 million strides, injured (n = 3) and uninjured (n = 6) participants did not report significantly different pain/fatigue (p = 0.56) or mean number of strides per run (p = 0.91). Injured participants did, however, have significantly greater peak vGRFs (p = 0.01) and weighted cumulative loading per run (p < 0.01). Results from this small but extensively studied sample of elite runners demonstrate that loading profiles (load magnitude-number combinations) quantified with activity monitors can provide valuable information that may prove essential for: (1) testing hypotheses regarding overuse injury mechanisms, (2) developing injury-prediction models, and (3) designing and adjusting athlete- and loading-specific training programs and feedback.

Transdermal Delivery of Functional Collagen Via Polyvinylpyrrolidone Microneedles

Collagen makes up a large proportion of the human body, particularly the skin. As the body ages, collagen content decreases, resulting in wrinkled skin and decreased wound healing capabilities. This paper presents a method of delivering type I collagen into porcine and human skin utilizing a polyvinylpyrrolidone microneedle delivery system. The microneedle patches were made with concentrations of 1, 2, 4, and 8% type I collagen (w/w). Microneedle structures and the distribution of collagen were characterized using scanning electron microscopy and confocal microscopy. Patches were then applied on the porcine and human skin, and their effectiveness was examined using fluorescence microscopy. The results illustrate that this microneedle delivery system is effective in delivering collagen I into the epidermis and dermis of porcine and human skin. Since the technique presented in this paper is quick, safe, effective and easy, it can be considered as a new collagen delivery method for cosmetic and therapeutic applications.

Self-assembly and sequence length dependence on nanofibrils of polyglutamine peptides

Huntington's disease (HD) is recognized as a currently incurable, inherited neurodegenerative disorder caused by the accumulation of misfolded polyglutamine (polyQ) peptide aggregates in neuronal cells. Yet, the mechanism by which newly formed polyQ chains interact and assemble into toxic oligomeric structures remains a critical, unresolved issue. In order to shed further light on the matter, our group elected to investigate the folding of polyQ peptides - examining glutamine repeat lengths ranging from 3 to 44 residues. To characterize these aggregates we employed a diverse array of technologies, including: nuclear magnetic resonance; circular dichroism; Fourier transform infrared spectroscopy; fluorescence resonance energy transfer (FRET), and atomic force microscopy. The data we obtained suggest that an increase in the number of glutamine repeats above 14 residues results in disordered loop structures, with different repeat lengths demonstrating unique folding characteristics. This differential folding manifests in the formation of distinct nano-sized fibrils, and on this basis, we postulate the idea of 14 polyQ repeats representing a critical loop length for neurotoxicity - a property that we hope may prove amenable to future therapeutic intervention. Furthermore, FRET measurements on aged assemblages indicate an increase in the end-to-end distance of the peptide with time, most probably due to the intermixing of individual peptide strands within the nanofibril. Further insight into this apparent time-dependent reorganization of aggregated polyQ peptides may influence future disease modeling of polyQ-related proteinopathies, in addition to directing novel clinical innovations.

Recent Developments in Diffusion Tensor Imaging of Brain

Magnetic resonance imaging (MRI) has come to be known as a unique radiological imaging modality because of its ability to perform tomographic imaging of body without the use of any harmful ionizing radiation. The radiologists use MRI to gain insight into the anatomy of organs, including the brain, while biomedical researchers explore the modality to gain better understanding of the brain structure and function. However, due to limited resolution and contrast, the conventional MRI fails to show the brain microstructure. Diffusion tensor imaging (DTI) harnesses the power of conventional MRI to deduce the diffusion dynamics of water molecules within the tissue and indirectly create a three-dimensional sketch of the brain anatomy. DTI enables visualization of brain tissue microstructure, which is extremely helpful in understanding various neuropathologies and neurodegenerative disorders. In this review, we briefly discuss the background and operating principles of DTI, followed by current trends in DTI applications for biomedical and clinical investigation of various brain diseases and disorders.

Polymeric Nanoparticles to Combat Squamous Cell Carcinomas in Patients with Dystrophic Epidermolysis Bullosa

Skin cancer is the leading cause of malignancy in the United States, with Basal Cell Carcinoma, Squamous Cell Carcinoma , and Melanoma being the three most common diagnoses, respectively. Squamous Cell Carcinoma (SCC) is a particular concern for patients suffering from Dystrophic Epidermolysis Bullosa (DEB), a disease that affects the production and function of collagen VII, a protein that forms the anchoring fibrils which bind the epidermis to the dermis. Patients with DEB suffer from chronic blistering and wounds that have impaired healing capabilities, often leading to the development of SCC and eventual mortality. Nanomedicine is playing an increasing role in the delivery of effective therapeutics to combat a wide range of diseases, including the imaging and treatment of SCC. In this review, we discuss the role of nanoparticles in the treatment of SCC with an emphasis on PLGA nanoparticles and SCCs found in patients suffering from DEB, and address recent patents that are pertinent to the development of novel nanomedical therapeutics.

Effect of age on the efficacy of tranexamic acid: An analysis of heterogeneity of treatment effect within the CRASH-2 dataset

BACKGROUND

Trauma is a major cause of morbidity and mortality in older adults and will become more common as the population ages. Tranexamic acid (TXA) is a lysine analogue frequently used in the setting of significant trauma with hemorrhage. The aim of this study is to investigate the heterogeneity of treatment effect of TXA as it relates to patient age during trauma care.

METHODS

We included patients from the CRASH-2 trial who were randomized within 3 h of injury. Patients were stratified into age groups <26 years, 26 to 35 years, 36 to 45 years, 46 to 55 years, and >55 years. Multiple logistic regression models were utilized to evaluate adjusted odds ratios (OR) with 95% confidence intervals (CI) for mortality. Heterogeneity of treatment effect was evaluated using Akaike and Bayesian information criteria to determine the optimum logistic regression model after which a Wald Chi-square test was utilized to evaluate statistical significance.

RESULTS

On univariate analysis, TXA administration decreased mortality within the <26 years cohort (decrease of 2.1%, 95% CI 0.2 to 4.0), 46 to 55 years cohort (decrease 6.7%, 95% CI 2.7 to 10.7), and >55 years cohort (decrease of 5.3%, 95% CI 0.4 to 10.3). On adjusted analysis, when compared to the 36 to 45 years cohort, the <26 year cohort experienced a decreased mortality (OR 0.72, 95% CI 0.62 to 0.85) whereas the >55 year cohort experienced increased mortality (OR 1.8, 95% CI 1.5 to 2.2). Assessment for heterogeneity of treatment effect of TXA administration between groups approached but did not reach statistical significance (p = 0.11).

CONCLUSIONS

Mortality related to trauma increases with age, however, there does not appear to be heterogeneity of treatment effect for TXA administration among different age groups.

Mortality and Complication Rates in Adult Trauma Patients Receiving Tranexamic Acid: A Single-center Experience in the Post-CRASH-2 Era

OBJECTIVES

The CRASH-2 trial demonstrated that tranexamic acid (TXA) in adults with significant traumatic hemorrhage safely reduces mortality. Given that the CRASH-2 trial did not include U.S. sites, our objective was to evaluate patient characteristics, TXA dosing strategies, and the incidence of mortality and adverse events in adult trauma patients receiving TXA at a U.S. Level I trauma center in the post-CRASH-2 era.

METHODS

We conducted a retrospective study that included patients aged 18 years or older who received TXA after an acute injury from July 2014 to June 2017. We excluded patients who received TXA orally, patients who received TXA for elective surgical procedures or nontrauma indications, patients who received it 8 hours or longer after the time of injury, and patients with cardiac arrest at time of emergency department arrival. Trained abstractors collected data from the trauma registry and hospital electronic medical records. Our primary outcome measures were in-hospital death and acute thromboembolic events within 28 days from injury.

RESULTS

We included 273 patients with a mean (±SD) age of 43.8 (±18.7)  years. The mean (±SD) time of administration of TXA from time of injury was 1.55 (±1.2)  hours with 229 patients (83.9%) receiving TXA within 3 hours. The overall mortality within 28 days from injury was 12.8% (95% confidence interval [CI] = 8.9% to 16.7%), which was similar compared to that in the CRASH-2 trial (14.5%, 95% CI = 13.9% to 15.2%). The incidence of acute thromboembolic events was 6.6% (95% CI = 3.7% to 9.5%), which was higher than that in the CRASH-2 trial (2.0%, 95% CI = 1.73% to 2.27%). Patients in our cohort also received surgery (64.8% vs. 47.9%) and blood transfusions (74.0% vs. 50.4%) more frequently than those in the CRASH-2 cohort.

CONCLUSIONS

Adult trauma patients receiving TXA had similar incidences of death but higher incidences of thromboembolic events compared to the CRASH-2 trial. Variation in patient characteristics, injury severity, TXA dosing, and surgery and transfusion rates could explain these observed differences. Further research is necessary to provide additional insight into the incidence and risk factors of thromboembolic events in TXA use.

Development of a model to measure the effect of off-balancing vectors on the delivery of high-quality CPR in a moving vehicle

AIM

We sought to develop a model to measure the acceleration and jerk vectors affecting the performance of High-Quality Cardiopulmonary Resuscitation (HQ-CPR) during patient transport.

METHODS

Three participants completed a total of eighteen rounds of compression only HQ-CPR in a moving vehicle. The vehicle was driven in a manner that either minimized or increased linear and angular vectors. The HQ-CPR variables measured were compression fraction (CF%), and percentages of compressions with correct depth > 5 cm (D%), rate 100-120 (R%), full recoil (FR%), and hand position (HP%). A composite HQ-CPR score was calculated: ((D% + R% + FR% + HP%)/4) * CF%). Linear and gyroscopic data were measured in the X, Y, and Z axes. The perceived difficulty in performing HQ-CPR was measured with the Borg Rating of Perceived Exertion Scale.

RESULTS

HQ-CPR data, linear vector data, and gyroscopic data were successfully recorded in all trial evolutions. Univariate regression analysis demonstrated that HQ-CPR was negatively affected by increasing magnitudes of linear acceleration (B = -0.093%/m/s², 95% CI [-0.17 - -0.02), p = 0.02], linear jerk (B = -0.134%/m/s³, 95% CI [-0.26 - -0.01], p = 0.04), angular velocity (B = -0.543%/radian/s, 95% CI [-0.98 - -0.11], p = 0.02), and angular acceleration (B = 0.863%/radian/s², 95% CI [-1.69 - -0.03], p = 0.04). Increasing vectors were negatively associated with FR% and R%. No difference was seen in D%, HP%, or CF%. Borg Rating of Perceived Exertion was greater in dynamic driving evolutions (8 ± 1 vs 3.5 ± 1.53, p = 0.02).

CONCLUSION

This model reliably measured linear and angular off-balancing vectors experienced during the delivery of HQ-CPR in a moving vehicle. In this preliminary report, compression rate and full recoil appear to be HQ-CPR variables most affected in a moving vehicle.

Headache and changes in artwork as a presentation of central venous sinus thrombosis in a child with acute lymphoblastic leukemia

Acute lymphocytic leukemia (ALL) is a common pediatric cancer diagnosis with excellent survival outcomes but significant morbidity, particularly during the induction phase of chemotherapy. Central venous sinus thrombosis (CVST) is a known potential complication of induction therapy; however, it occurs rarely and may be difficult to diagnose, particularly in young children who have limited verbal skills. Herein, we report a case of CVST in a child with B-cell ALL undergoing induction chemotherapy whose main symptoms were headache and a change in the appearance of his artwork noticed by his parents. This astute observation by the child's parents played a critical role in his diagnosis, allowing prompt treatment and eventual recovery.

A 70-Year-Old Woman With Refractory Hypoxemia

CASE PRESENTATION

A 70-year-old woman was transferred to our ED from an outside ED for hypoxemia. Three weeks earlier, an inpatient evaluation for syncope revealed a right intraventricular filling defect, multiple pulmonary nodules, pulmonary emboli, and a left breast mass. She underwent breast biopsy, was started on rivaroxaban, and was discharged with outpatient follow-up. She experienced progressively worsening dyspnea, prompting a return to the outside ED, where she was found to be severely hypoxemic and was intubated. Her medical history included diabetes, hypertension, hyperlipidemia, COPD, hypothyroidism, diastolic heart failure, and a 40+ pack-year smoking history.

Patient Characteristics and Procedural Volume at an Overseas Military Treatment Facility Emergency Department: Effects of the COVID-19 Pandemic and Implications on Clinical Skill Sustainment

INTRODUCTION

Future conflicts against near-peer competitors require proficient physicians to mitigate operational morbidity and mortality. Recent literature suggests that current patient demographics and staffing models may not sustain the combat care skills of military physicians. However, skill sustainment at overseas military treatment facilities located within foreign countries has not been examined. This article investigates patient characteristics and procedural performance rates within the U.S. Naval Hospital Okinawa Emergency Department (USNHO-ED), providing novel insight into the skill sustainment provided to U.S. Military physicians stationed in a foreign country.

MATERIALS AND METHODS

An automated retrospective chart review of patients triaged within the USNHO-ED from January 2018 to June 2022 was performed. Patient census, emergency severity index (ESI) triage scores, patient disposition, and procedures of interest were recorded. Procedures of interest included: "endotracheal intubation," "arterial line placement," "central line placement," "dislocation reduction," "procedural sedation," "cardioversion," "thoracostomy," "blood product transfusion," "lumbar puncture," "paracentesis," "arthrocentesis," and "joint injection." Monthly procedure rates and procedure rates per 1,000 patients were calculated. Procedure rates for individual physicians with greater than 500 patient encounters were calculated. Variation in patient characteristics and procedural rates during the COVID-19 pandemic was investigated.

RESULTS

The USNHO-ED triaged 128,696 patients and performed 865 procedures of interest during the study period. In total, 5,020 patients were triaged as ESI 1/2, 34,179 patients were triaged as ESI 3, and 89,499 patients were triaged as ESI 4/5. A total of 122,881 patients were discharged from the emergency department. The procedures performed most often were procedural sedation (4.02 per month, 2.06 per 1,000 patients), dislocation reduction (3.41 per month, 1.75 per 1,000 patients), lumbar puncture (1.94 per month, 0.99 per 1,000 patients), and endotracheal intubation (1.21 per month, 0.62 per 1,000 patients). All other procedures were performed less than once per month and 0.5 instances per 1,000 patients. Over half of physicians with at least 500 encounters did not perform a blood product transfusion, thoracostomy, central line placement, arterial line placement, cardioversion, or paracentesis. Rates for many procedures were lower than those seen at civilian institutions. During the COVID-19 pandemic, the daily census was lower, patients were more often triaged to higher ESI 1-3, and the admission rate was higher. Procedural sedations per month, as well as procedural sedations, dislocation reductions, and blood product transfusions per 1,000 patients, increased during the COVID-19 pandemic. No other temporal procedural variation occurred. Pediatric patients were more often triaged to ESI 4/5, more likely to be discharged, more likely to undergo procedural sedation, and less likely to undergo endotracheal intubation, blood product transfusion, thoracostomy, central line placement, cardioversion, or joint invasive procedures.

CONCLUSIONS

This study demonstrates a low patient volume, patient acuity, and procedural performance rate for physicians at USNHO-ED. The inability of military physicians stationed in foreign locations to leverage the local civilian market further reduces their ability to maintain operational readiness. In combination, these hindrances degrade physician readiness, creating significant risk in the ability to support warfighters engaged in combat operations. Unique staffing models and partnerships must be developed to maintain the proficiency of overseas military physicians.

Measuring the Effect of Off-Balancing Vectors on the Delivery of High-Quality CPR during Ambulance Transport: A Proof of Concept Study

AIM

This study aims to demonstrate the feasibility of quantifying the off-balancing vectors experienced during ambulance transport and comparing them to high-quality cardiopulmonary resuscitation (HQ-CPR) metrics.

METHODS

Ten participants completed a total of 20 evolutions of compression-only HQ-CPR in an ambulance driven in a manner that minimized or increased linear and angular off-balancing vectors. Linear and angular velocity, linear and angular acceleration, and linear jerk were recorded. HQ-CPR variables measured were compression fraction and proportion of compressions with depth >5 cm (depth%), rate 100-120 (rate%), full chest recoil (recoil%), and hand position (hand%). A composite score was calculated: [(depth% + rate% + recoil% + hand%)/4) * compression fraction]. Difficulty of HQ-CPR performance was measured with the Borg rating of perceived exertion (RPE) Scale. A series of mixed effects models were fitted regressing each HQ-CPR metric on each off-balancing vector.

RESULTS

HQ-CPR data and vector quantity data were successfully recorded in all evolutions. Rate% was negatively associated with increasing linear velocity (slope = -3.82, standard error [SE] 1.12, p = 0.005), linear acceleration (slope = -5.52, SE 1.93, p = 0.013), linear jerk (slope = -17.60, SE 5.78, p = 0.007), angular velocity (slope = -75.74, SE 22.72, p = 0.004), and angular acceleration (slope = -152.53, SE 59.60, p = 0.022). Compression fraction was negatively associated with increasing linear velocity (slope = -1.35, SE 0.37, p = 0.004), linear acceleration (slope = -1.67, SE 0.48, p = 0.003), linear jerk (slope = -4.90, SE 1.86, p = 0.018), angular velocity (slope = -25.66, SE 6.49, p = 0.001), and angular acceleration (slope = -45.35, SE 18.91, p = 0.031). Recoil% was negatively associated with increasing linear velocity (slope = -5.80, SE 2.21, p = 0.023) and angular velocity (slope = -116.96, SE 44.24, p = 0.019)). Composite score was negatively associated with increasing linear velocity (slope = -4.49, SE 1.45, p = 0.009) and angular velocity (slope = -86.13, SE 31.24, p = 0.014) and approached a negative association with increasing magnitudes of linear acceleration (slope -5.54, SE 2.93, p = 0.075), linear jerk (slope = -17.43, SE 8.80, p = 0.064), and angular acceleration (slope = -170.43, SE 80.73, p = 0.051). Borg RPE scale was positively associated with all off-balancing vectors. Depth%, hand%, mean compression depth, and mean compression rate were not correlated with any off-balancing vector.

CONCLUSION

Off-balancing vector data can be successfully quantified during ambulance transport and compared with HQ-CPR performance parameters. Increasing off-balancing vectors experienced during ambulance transport are associated with worse HQ-CPR metrics and increased perceived physical exertion. These data may help guide future drive styles, ambulance design, or use of mechanical CPR devices to improve HQ-CPR delivery during selected patient transport scenarios.

Tension Pneumomediastinum and Coronary Artery Thrombosis Following a Motorcycle Accident: A Case Report

INTRODUCTION

Tension pneumomediastinum and coronary artery thrombosis (CAT) secondary to blunt polytrauma are, rare yet have the potential for serious complication.

CASE REPORT

A 40-year-old man presented to the emergency department following a motorcycle accident. He was found to have multiple orthopedic injuries, pneumothorax, and pneumomediastinum. An electrocardiogram showed myocardial infarction. He developed obstructive shock physiology that resolved with mediastinal percutaneous needle drainage. Subsequent coronary angiography revealed acute thrombosis of the left circumflex artery.

CONCLUSION

This is a rare case of traumatic tension pneumomediastinum associated with coronary artery thrombosis requiring coronary stenting. Emergency physicians should be mindful of CAT in the setting of blunt chest injury.