bluuebunny/crossref_metadata_2025 huggingface dataset:
Prevalence of Underlying Medical Conditions Associated With Severe COVID-19 Illness in Adult Cancer Survivors in the United States
Authors: Jiang Changchuan , Yabroff K Robin , Deng Lei , Perimbeti Stuthi , Han Xuesong
Published: January 2021

Cancer, and other underlying medical conditions including chronic obstructive pulmonary disease, heart diseases, diabetes, chronic kidney disease, and obesity, are associated with increased risk of severe coronavirus disease 2019 (COVID-19) illness. We identified 6411 cancer survivors and 77 748 adults without a cancer history from the 2016-2018 National Health Interview Survey and examined the prevalence and sociodemographic factors associated with these conditions in the United States. Most survivors reported having 1 or more of the conditions (56.4%, 95% confidence interval [CI] = 54.8% to 57.9%, vs 41.6%, 95% CI = 40.9% to 42.2%, in adults without a cancer history), and nearly one-quarter (22.9%, 95% CI = 21.6% to 24.3%) reported 2 or more, representing 8.7 million and 3.5 million cancer survivors, respectively. These conditions were more prevalent in survivors of kidney, liver, and uterine cancers as well as Black survivors and those with low socioeconomic status and public insurance. Findings highlight the need to protect survivors against COVID-19 transmission in health-care facilities and to prioritize cancer patients, survivors, caregivers, and their health-care providers in vaccine allocation.
Adaptive responses to drought of twoRetama raetamsubspecies from Tunisia
Authors: Gil Ricardo , Zayoud Dhikra , Ouerghi Zeineb , Boscaiu Monica , Vicente Oscar , Neffati Mohamed
Published: January 2021

Aims

The survival and ecological distribution of plants in arid habitats are mainly conditioned by water availability and physiological adaptations to withstand drought. In the present study, we have compared the physiological responses to drought of two Retama raetam (retama) subspecies from Tunisia, one of them living under the desert climate (subsp. raetam) and the other one growing on the coast (subsp. bovei).

Methods

To physiologically characterize the two R. raetam subspecies, and to elucidate their main mechanisms underlying their tolerance to drought stress, parameters related to seed germination, growth, photosynthesis (net photosynthetic rate, intracellular CO2 concentration, transpiration rate, stomatal conductance and water-use efficiency) and accumulation of osmolytes (proline, glycine betaine [GB] and soluble sugars) were determined in 4-month-old plants subjected to stress for up to 1 month.

Important Findings

Drought significantly inhibited germination, growth and all the evaluated photosynthetic parameters. Plants of R. raetam subsp. bovei were severely affected by drought after 3 weeks of treatment when photosynthesis rates were up to 7-fold lower than in the controls. At the same time, proline and GB significantly accumulated compared with the irrigated controls, but much less than in R. raetam subsp. raetam; in the latter subspecies, proline and GB increased to levels 24- and 6-fold higher, respectively, than in the corresponding controls. In summary, the population living in the desert region exhibited stronger tolerance to drought stress than that adapted to the semiarid littoral climate, suggesting that tolerance in R. raetam is dependent on accumulation of osmolytes.
Above- and belowground trait linkages of dominant species shape responses of alpine steppe composition to precipitation changes in the Tibetan Plateau
Authors: Zheng Zhi , Zhang Yue , Zhang Shihu , Ma Qun , Gong Dajie , Zhou Guoying
Published: January 2021

Aims

Human activities and global changes have led to alterations in global and regional precipitation regimes. Despite extensive studies on the effects of changes in precipitation regimes on plant community composition across different types of grassland worldwide, few studies have specifically focused on the effects of precipitation changes on high-altitude alpine steppe at community and plant species levels in the Tibetan Plateau.

Methods

We investigated the effects of growing-season precipitation changes (reduced precipitation by 50%, ambient precipitation, enhanced precipitation by 50%) for 6 years on plant community composition in an alpine steppe of the Tibetan Plateau by linking above- to belowground traits of dominant species.

Important Findings

We found that reduced precipitation shifted community composition from dominance by bunchgrass (primarily Stipa purpurea) to dominance by rhizomatous grass (primarily Leymus secalinus). Roots and leaf traits of L. secalinus and S. purpurea differed in their responses to reduced precipitation. Reduced precipitation enhanced root vertical length and carbon (C) allocation to deep soil layers, and decreased the leaf width in L. secalinus, but it did not change the traits in S. purpurea. Moreover, reduced precipitation significantly enhanced rhizome biomass, length, diameter and adventitious root at the rhizome nodes in L. secalinus. These changes in traits may render rhizomatous grass greater competitive during drought stress. Therefore, our findings highlight important roles of above- and belowground traits of dominant species in plant community composition of alpine steppe under precipitation change.
Development of intravaginal rod insert bearing liposomal raloxifene hydrochloride and Leuprolide acetate as a potential carrier for uterine targeting
Authors: Patel Arpita , Dhande Rahul , Thakkar Hetal
Published: January 2021

Objectives

This project aimed at the formulation of dual drug entrapped liposomes held as freeze-dried intravaginal rod insert (IVR), to be administered by vaginal route for uterine targeting.

Methods

Liposomes were formulated by dehydration–rehydration method using 3 : 1 molar ratio of1,2-distearoyl-sn-glycero-3-phosphocholine : Cholesterol. Characterization was done for vesicle size, zeta potential, entrapment efficiency, surface morphology and % loading.

Key findings

Spherical and discrete vesicles of size 354 nm were observed in transmission electron microscopy (TEM) image. The entrapment efficiency of 90.91% and 74.3% w/w was obtained for Raloxifene Hydrochloride (RLX) and Leuprolide acetate (LA) respectively. Drug release was sustained for 6 days. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay results showed that dual drug entrapped liposomal formulation show significant cytotoxicity, as also confirmed by higher apoptosis in cell cycle analysis and apoptosis studies (FACS) analysis. Pharmacodynamic studies in New Zealand white female rabbits revealed that intravaginal administration of RLX-LA entrapped liposomal formulation shows considerable fibroid regression.

Conclusions

Uterine targeting of liposomal RLX-LA suggests its potential to solve the limitations of the presently available therapeutic options.
Syrians in Sweden: Constructing Difference Regarding Gender and Family
Authors: Rabo Annika , Estrada Tun Paula , Jörum Emma
Published: January 2021

In this article, we look at the discourse used by the Swedish state in describing non-European migrants, among them Syrians, and how this has constructed cultural divisions between ‘native’ Swedes and Syrian migrants. We reveal how non-European immigrants are depicted and treated by the state as coming from ‘patriarchal’ and ‘collectivist’ cultures and are therefore in need of development. We then connect this framing of migrant culture to how honour-related violence is constructed by the state and public institutions and explain how such a framing of violence is problematic. We also look at how some Syrian migrants have in turn employed stereotypical language in their depiction of Swedish culture and the Swedish state. Engaging with existing work on ethnic groups and boundaries, we find that this boundary-making process by both migrants and the state produces a perception of difference among groups.
The value of a combined radiological–surgical approach in allowing curative resection of a locally advanced type IIIa Klatskin tumor
Authors: Fronda Marco , Patrono Damiano , Doriguzzi Breatta Andrea , Osella Giulia , Gazzera Carlo , Paraluppi Gianluca , Fonio Paolo , Righi Dorico , Romagnoli Renato
Published: January 2021

We report the case of a 53-year-old patient subjected to percutaneous embolization of right and middle hepatic veins to induce liver segments 2–3 hypertrophy before extended right hepatic resection for a locally advanced type IIIa perihilar cholangiocarcinoma.

Hepatic vein embolization (HVE) was performed 3 weeks after surgical recanalization of left portal vein (severely narrowed at its origin due to tumor infiltration) interposing an internal jugular vein graft between main and distal left portal vein.

Nine days after HVE, future liver remnant volume increased from 395 to 501 cc, i.e. 25.1% of standardized total liver volume, allowing to perform a radical right hepatic trisectionectomy plus caudatectomy. He was discharged home on postoperative day 15th after an uneventful postoperative course, with no sign of posthepatectomy liver failure.
Sky High or Undetectable? A Patient with Discordant Hemoglobin A1c
Authors: Lee Patricia , Chambliss Allison B , Marin Maximo J
Published: January 2021

A female patient aged 47 years presented with a hemoglobin A1c (HbA1c) level of 54.6%, as measured by ion-exchange high-performance liquid chromatography (HPLC), and a glucose level of 106 mg/dL. The HbA1c was re-evaluated using a turbidimetric inhibition immunoassay and found below the level of detection. Hemoglobinopathy testing led to the identification of a hemoglobin variant consistent with Hb Raleigh, in which a valine → alanine substitution on the beta chain effects a charge difference, resulting in coelution with HbA1c on HPLC and a spuriously high reading. Many Hb variants may interfere with HbA1c measurement and generate misleading results. The unique properties of Hb Raleigh may give rise to analytical errors when evaluating HbA1c using 2 different methods—molecular charge–based (eg, HPLC) and molecular structure–based (eg, immunoassay)—yielding diametrically opposed results. Consequently, recognition and diagnosis of this entity are essential in patients with Hb Raleigh, especially when monitoring long-term glucose control.
A Biomimetic Adapter for Passive Self-alignment of Prosthetic Feet
Authors: Rajula Vamsidhar Reddy , Springgate Logan , Haque Aman , Kamrunnahar Mst , Piazza Stephen J , Kaluf Brian
Published: January 2021

Introduction

Dynamic alignment of lower limb prostheses is subjective and time-consuming. Compensatory gait strategies caused by prosthesis misalignment can negatively affect lower limb amputees who cannot access a certified prosthetist for alignment adjustments. The objective of this study is to evaluate a novel six-degrees-of-freedom passive transtibial prosthetic adapter that self-aligns during various phases of gait. This self-aligning adapter may benefit service members and veterans stationed or living far from a clinical facility.

Methods

Four transtibial amputee subjects, aged 47 to 62 (mean: 55.75) years with mean weight of 163.6 lbs and mean K-level of 3.25, walked at self-selected speeds on a 10-m level walkway. Subjects walked with the self-aligning and a size- or weight-matched control adapter, assembled to a commercially available energy-storing-and-returning foot and their own socket, with 22-mm alignment perturbations in the anterior, posterior, medial, or lateral directions. Subjects were blinded to both adapter type and misalignment. Socket moments, spatiotemporal gait parameters, and subjective socket comfort were recorded.

Results

Preliminary results showed improvements in mean peak socket moments and step length differential with the self-aligning adapter across all alignments. Walking speed and prosthesis-side base of support showed little change in all configurations. Prosthesis-side stance duration and Functional Ambulation Profile Score increased with the self-aligning adapter in some alignments. Patient-reported socket comfort increased slightly with the self-aligning adapter across all misalignments.

Conclusion

Subjects maintained similar walking speeds and experienced greater gait symmetry and reduced sagittal plane peak moments with the self-aligning adapter when exposed to misalignments. These trends suggest a benefit to transtibial amputees from a reduction in secondary gait effects from prosthesis misalignments. Additionally, a wider range of acceptable prosthesis alignments may be possible with the self-aligning adapter. Subsequent trials are underway to evaluate the self-aligning adapter in real-world environments like walking on uneven terrains, stairs, ramps, and abrupt turns.
Local Respiratory Viral Surveillance Can Focus Public Health Interventions to Decrease Influenza Disease Burden
Authors: Crouch Elena , Gonzalez Jonathan , Jacobs Erin , Schaecher Kurt , Kehl Margaret , Ottolini Martin , Malloy Allison
Published: January 2021

Background

Respiratory viruses are an important cause of nonbattle injury disease and contribute to the top seven reasons for medical encounters. In the absence of vaccines that provide complete protection against these viruses, viral surveillance can identify disease burden and target virus-specific preventative measures. Influenza infection, in particular, has significant adverse effects on force readiness.

Methods

We tracked the frequency of 16 respiratory viruses at Walter Reed National Military Medical Center tested for during routine patient care using multiplex polymerase chain reaction and rapid antigen testing. We collected data on the date and location of the testing, as well as the age of the individual tested from two consecutive respiratory viral seasons.

Results

During the first year of data compilation (2017-2018), 2556 tests were performed; 342 (13.4%) were positive for influenza A and 119 (4.7%) were positive for influenza B. After influenza, the most common families of viruses identified were rhino/enterovirus (490 [19.2%]). During the second year (2018-2019), 4,458 tests were run; 564 (12.7%) were positive for influenza A and 35 (0.79%) were positive for influenza B, while rhino/enterovirus was identified in 690 (15.4%). Influenza peaked early during the 2017-2018 season and later during the 2018-2019 season. Importantly, during the 2017-2018 season, the vaccine was less effective for the H3N2 strain circulating that year and viral surveillance quickly identified a hospital-specific outbreak and a larger disease burden. This was in contrast to the 2018-2019 vaccine which exhibited higher effectiveness for circulating strains.

Conclusion

Our data highlight the seasonality of respiratory viruses with a focus on influenza. By tracking respiratory viruses in Department of Defense communities, we may be able to predict when influenza may cause the greatest burden for distinct organizational regions and prescribe with greater precision preventative protocols by location, as well as rapidly determine vaccine efficacy. Our current data suggest that when vaccine strains are mismatched, rapid upfront targeting of antivirals may be warranted, but when the vaccine strains are better matched, late season peaks of disease may indicate waning immunity and should be monitored.
Model to Predict Probability of Significant Skin Burn Injury From a Directed-Energy Source
Authors: Iyoho Anthony , Ng Laurel J
Published: January 2021

Introduction

Millimeter wave directed energy in the frequency regime of 94-95 GHz has potential for use in numerous military applications including crowd control and area denial. Although proven to be very safe, millimeter wave energy has the potential, because of accidental over exposure, to produce significant injuries. Currently, the Dynamic Thermal Model (DTM), developed by Beason and colleagues, is used to calculate the temperature profile in skin undergoing (millimeter wave) heating, using an all-or-nothing threshold of injury. Risk of significant injury (RSI) is determined by product of the probability of an injury outcome on a region of the body times the probability of that the injury will occur. Thus, a threshold injury determination may over predict burn probability and fail safety requirements. This work augments the DTM, replacing the current threshold value of injury with a probabilistic risk of injury to better quantify the risk of significant injury.

Materials and Methods

In this study, continuous probabilistic dose–response models using logistic regression analysis have been developed to account for mild second-degree, deep second-degree, and third-degree burn injuries based on a historic experimental burn dataset. Statistical analysis methods such as Hosmer–Lemeshow statistics, McFadden’s pseudo R2 and receiver operator characteristic were used to validate the models against an independent experimental burn dataset.

Results

Comparison of logistic models fit using damage coefficients from the literature showed that Mehta and Wong provided the best fits historic burn data, which was corroborated by the McFadden pseudo R2 statistic for mild second-degree, deep second-degree, and third-degree severity.

Conclusion

The dose–response models developed in this study are shown to be an excellent predictor of burn injury for each severity. The DTM was repackaged with the probabilistic burn models to more accurately determine the risk of significant burn injury.
Mental Health Symptoms Among Veteran VA Users by Tinnitus Severity:A Population-based Survey
Authors: Prewitt Austin , Harker Graham , Gilbert Tess A , Hooker Elizabeth , O’Neil Maya E , Reavis Kelly M , Henry James A , Carlson Kathleen F
Published: January 2021

Introduction

Tinnitus is prevalent among Service members and Veterans and is often comorbid with mental health disorders. Associations between the severity of individuals’ tinnitus and mental health symptoms are not well described.

Materials and Methods

We conducted a population-based survey of a stratified random sample of 1,800 Veterans diagnosed with tinnitus. We used the Tinnitus Functional Index to measure tinnitus severity and the Primary Care-Posttraumatic Stress Disorder (PTSD) screen and the Hospital Anxiety and Depression Scale to assess PTSD, depression, and anxiety. Descriptive statistics and bivariable and multivariable regression models were used to estimate associations between Veterans’ tinnitus severity and mental health symptoms. Inverse probability weights were used to account for sample stratification and survey non-response. Multivariable odds ratios (ORs) and 95% confidence intervals (CIs) controlled for Veterans’ demographics, military history, and health diagnoses.

Results

A total of 891 Veterans completed surveys (adjusted response rate = 53%). Large proportions rated their tinnitus as severe (29.4%; 95% CI: 27.2-31.6) or very severe (18.7%; 95% CI: 16.8-20.5). In multivariable regression models, and compared with Veterans with none/mild tinnitus, the likelihood of screening positive for PTSD was increased for those who reported moderate (OR = 4.0; 95% CI: 1.6-10.3), severe (OR = 7.5; 95% CI: 3.1-18.5), or very severe (OR = 17.5; 95% CI: 4.4-70.0) tinnitus. Similarly, Veterans’ likelihood of positive depression screens were elevated for those with moderate (OR = 2.6; 95% CI: 1.1-5.9), severe (OR = 3.0; 95% CI: 1.4-6.5), or very severe (OR = 15.5; 95% CI: 4.3-55.5) tinnitus, as was the likelihood of positive anxiety screens for those with severe (OR = 2.6; 95% CI: 1.1-6.3) or very severe (OR = 13.4; 95% CI: 4.0-44.3) tinnitus.

Conclusions

Mental health symptoms are strongly associated with Veterans’ tinnitus severity. A better understanding of the interplay between these conditions may help improve the provision of interdisciplinary (Audiology and Mental Health) care for Service members and Veterans.
Optimal Initial Positioning of Chest Tubes to Prevent Retained Hemothorax Using a Novel Steerable Chest Tube With Extendable Infusion Cannula
Authors: Fortune John B , Murphy Serena , Tiller Kimberley
Published: January 2021

Introduction

With blunt and penetrating trauma to the chest, warfighters and civilians frequently suffer from punctured lung (pneumothorax) and/or bleeding into the pleural space (hemothorax). Optimal management of this condition requires the rapid placement of a chest tube to evacuate as much of the blood and air as possible. Incomplete drainage of blood leading to retained hemothorax may be the result of the final tube tip position not being in contact with the blood collections. To address this problem, we sought to develop a “steerable” chest tube that could be accurately placed or repositioned into a specific desired position in the pleural space to assure optimal drainage. An integrated infusion cannula was added for the instillation of anticoagulants to maintain tube patency, thrombolytics for clot lysis, and analgesics for pain control if required.

Materials and Methods

A triple-lumen tube was designed to provide a channel for a pull-wire which was wound around an axle integrated into a small proximal handle and controlled by a ratcheted thumbwheel. Tension on the wire creates an arc on the tube that allows for positioning. In vitro testing focused on the relationship between the tension on the pull-wire and the resultant arc. Two adult cadavers and two anesthetized pigs were used to study the feasibility of accurate tube placement. After a brief training session, providers were asked to place tubes inferiorly along the diaphragm where blood was anticipated to accumulate or at the apex of the lung for pneumothorax. Success was determined with fluoroscopic images and was judged as a tube tip lying in the targeted position.

Results

The design was prototyped with an extruded polyvinyl chloride multilumen tube and a 3D printed tensioning handle. In vitro studies showed that one turn of the thumbwheel created 70° to 90° of arc of the tube. Cadaver and animal studies showed consistent success in the desired placement of the tube at or near the lateral diaphragm or in the apex. Attempts were also successful by surgical residents with minimal training.

Conclusions

Initial preliminary studies on a novel steerable chest tube have demonstrated the ability to appropriately position the tube in a desired location. The addition of an extendable cannula will allow for safe clot lysis or maintained tube patency. Additional studies are planned to confirm the benefit of this device in preventing retained hemothorax.
Potential Concussive Event Narratives of Post-9/11 Combat Veterans: Chronic Effects of Neurotrauma Consortium Study
Authors: Yee Jonathan , Marchany Katelyn , Greenan Mary Alexis , Walker William C , Pogoda Terri K
Published: January 2021

Introduction

Deployment-related mild traumatic brain injury (mTBI) affects a significant proportion of those who served in Post-9/11 combat operations. The prevalence of head injuries, including those that lead to mTBI, is often reported quantitatively. However, service member (SM) and Veteran firsthand accounts of their potential concussive events (PCEs) and mTBIs can serve as a rich resource for better understanding the nuances and context of these exposures.

Materials and Methods

Post-9/11 SMs and Veterans with a history of combat deployment were recruited through the Chronic Effects of Neurotrauma Consortium’s observational study of deployment-related mTBI. During a comprehensive assessment, participants completed the Virginia Commonwealth University retrospective Concussion Diagnostic Interview, a specialized validated interview measure which obtains detailed narratives of deployment-incurred blast and non-blast-related PCEs. Qualitative thematic analysis was used to identify and code recurring themes within the narratives.

Results

Among the sample of 106 SMs and Veterans, deployment-related mTBI was highly prevalent (67.0%). Over half (50.9%) of the participants identified a blast as the cause of their worst PCE, frequently with accompanying themes of self-reported acute neurological symptoms, intense physical blast forces, and tertiary head impact. Exposure to blast at close range, such as driving directly over an improvised explosive device, occurred in 24.7% of all blast-related narratives and in 59.3% of narratives where blast was identified as causing the worst PCE. Themes of potentially preventable head impacts experienced during noncombat circumstances were also frequent, accounting for 35% of all non-blast-related head injuries in the sample.

Conclusions

Prevalence of deployment-related close-range blast exposure, non-blast impact PCEs, and mTBIs among this Post-9/11 combatant sample was substantial, and in many cases potentially preventable. The use of detailed semi-structured interviews may help health care providers and policymakers to better understand the context and circumstances of deployment-related PCEs and mTBIs.
Enteral Nutrition in the Deployed Critical Care Ground and Air Transport Environment: A Narrative Review
Authors: Woody Sarah , Brown Kayla N , Bevington Daniel , Huffman Sarah
Published: January 2021

Introduction

Early and adequate administration of enteral nutrition (EN) improves outcomes in critical care patients. However, the environment where Critical Care Air Transport teams provide patient care poses particular challenges to achieving the same standard of nutritional support readily administered in civilian intensive care units. Providing the highest standard of nutritional care in austere military environments remains the goal for all patients despite inherent challenges. Enteral nutrition, specifically, is not currently a standard of practice in-flight because of concerns for microaspiration and the associated risk of developing ventilator-associated pneumonia. Clinical concern for aspiration combines with the lack of an EN pump approved for use through Safe-to-Fly testing to further decrease the likelihood of initiating EN in trauma patients. Early EN significantly reduces morbidity and mortality risks; therefore, the lack of nutritional support is contrary to established standards of care in civilian intensive care units. Hence, this literature review proposes to provide a clearer understanding of current EN practices as well as any associated risks within the En Route Care system.

Method

A narrative review of literature related to EN in military and civilian flight settings using the PRISMA methodology.

Results

A search using the key terms of critical care, air ambulance, EN, nutritional status, and aspiration returned a total of 51,990 articles. A title review followed by a more targeted abstract analysis by the research team generated 39 articles for full-text review. The full-text review then yielded a total of 10 relevant articles for inclusion in the final synthesis table.

Conclusions

Overall, the consensus of the literature supports that early evaluation and initiation of standard EN feeding protocols on the ground and during transport improves patient outcomes and enhances injury recovery. However, additional research will determine the current number of patients fed in-flight along with the actual risks and benefits of EN in this population.
4-Aminopyridine: A Single-Dose Diagnostic Agent to Differentiate Axonal Continuity in Nerve Injuries
Authors: Gurjar Anagha A , Manto Kristen M , Estrada Juan A , Kaufman Marc , Sun Dongxiao , Talukder M A Hassan , Elfar John C
Published: January 2021

Introduction

Traumatic peripheral nerve injuries (TPNIs) are increasingly prevalent in battlefield trauma, and the functional recovery with TPNIs depends on axonal continuity. Although the physical examination is the main tool for clinical diagnosis with diagnostic work up, there is no diagnostic tool available to differentiate nerve injuries based on axonal continuity. Therefore, treatment often relies on “watchful waiting,” and this leads to muscle weakness and further reduces the chances of functional recovery. 4-aminopyridine (4-AP) is clinically used in multiple sclerosis patients for walking performance improvement. Preliminary results in conscious mice suggested a diagnostic role of 4-AP in distinguishing axonal continuity. In this study, we thought to evaluate the diagnostic potential of 4-AP on the axonal continuity in unawake/sedated animals.

Materials and Methods

Rat sciatic nerve crush and transection injuries were used in this study. Briefly, rats were anesthetized with isoflurane and mechanically ventilated with oxygen-balanced vaporized isoflurane. Sciatic nerve and triceps surae muscles were exposed by blunt dissection, and a stimulating electrode was placed under a sciatic nerve proximal to the crush injury. A force transducer measured muscle tension response to electrical stimulation of sciatic nerve. Muscle response was measured before crush, after crush, and 30 minutes after systemic 4-AP (150 µg/kg) or local (4-AP)-poly(lactide-co-glycolide)-b-poly(ethylene glycol)-b-poly(lactide-co-glycolide) (PLGA-PEG) treatment.

Results

We found that both crush and transection injuries in sciatic nerve completely abolished muscle response to electrical stimulation. Single dose of systemic 4-AP and local (4-AP)-PLGA-PEG treatment with crush injury significantly restored muscle responses to electrical stimulation after 30 minutes of administration. However, systemic 4-AP treatment had no effect on muscle response after nerve transection. These results clearly demonstrate that 4-AP can restore nerve conduction and produce muscle response within minutes of administration only when there is a nerve continuity, even in the sedated animal.

Conclusions

We conclude that 4-AP could be a promising diagnostic agent in differentiating TPNI based on axonal continuity.
Vertebral Level-dependent Kinematics of Female and Male Necks Under G+x Loading
Authors: Yoganandan Narayan , Baisden Jamie L , John Jobin , Saravana Kumar Gurunathan , Banerjee Anjishnu , Choi Hoon
Published: January 2021

Introduction

Size-matched volunteer studies report gender-dependent variations in spine morphology, and head mass and inertia properties. The objective of this study was to determine the influence of these properties on upper and lower cervical spine temporal kinematics during G+x loading.

Methods

Parametrized three-dimensional head-neck finite element models were used, and impacts were applied at 1.8 and 2.6 m/s at the distal end. Details are given in the article. Contributions of population-based variations in morphological and mass-related variables on temporal kinematics were evaluated using sensitivity analysis. Influence of variations on time to maximum nonphysiological curve formation, and flexion of upper and extension of the lower spines were analyzed for male-like and female-like spines.

Results

Upper and lower spines responded with initial flexion and extension, resulting in a nonphysiological curve. Time to maximum nonphysiological curve and range of motions (ROMs) of the cervical column ranged from 45 to 66 ms, and 30 to 42 deg. Vertebral depth and location of the head center of gravity (cg) along anteroposterior axis were most influential variables for the upper spine flexion. Location of head cg along anteroposterior axis had the greatest influence on the time of the curve. Both anteroposterior and vertical locations of head cg, disc height, vertebral depth, head mass, and size were influential for the lower spine extension kinematics.

Conclusions

Models with lesser vertebral depth, that is, female-like spines, experienced greater range of motions and pronounced nonphysiological curves. This results in greater distraction/stretch of the posterior upper spine complex, a phenomenon attributed to suboccipital headaches. Forward location of head cg along anteroposterior axis had the greatest influence on upper and lower spine motions and time of formation of the curve. Any increased anteroposterior location of cg attributable to head supported mass may induce greater risk of injuries/neck pain in women during G+x loading.
Comparison of the Effects of Motion and Environment Conditions on Accuracy of Handheld and Finger-Based Pulse Oximeters
Authors: Mark Noy , Lyubin Anat , Gerasi Refael , Ofir Dror , Tsur Avishai M , Chen Jacob , Bader Tarif
Published: January 2021

Introduction

The most common cause of preventable death on the battlefield is significant blood loss, eventually causing decrease in tissue oxygen delivery. Pulse oximeters (POs) are widely used by the Israeli Defense Forces to obtain fast and noninvasive information about peripheral oxygen saturation (SpO2). However, POs are produced by different manufacturers and therefore include different sensors and are based on distinctive algorithms. This makes them susceptible to different errors caused by factors varying from environmental conditions to the severity of injury. The objectives of this study were to compare the reliability of different devices and their accuracy under various conditions.

Material and Methods

Six POs underwent performance analysis. The finger-based category included: MightySat by Masimo, Onyx II by Nonin, and CMS50D by Contec. The handheld category comprised: RAD5 by Masimo, 9847 model by Nonin, and 3301 model by BCI. Several environmental and physiological parameters were altered using the ProSim8 simulator by Fluke biomedical, forming unique test cases under which the devices were tested in stationary and motion conditions.

Results

All finger-based POs showed higher error rates of PO SpO2 and heart rate measurements in motion conditions, regardless of the manufacturer. However, newer devices in the handheld category were not affected. Results presented in Phase II showed that the SpO2 measurement error in all the devices was affected by pigmentation. However, the CMS50D, considered a low-cost device, had a significantly higher error size than other devices. In the devices that were influenced both by pigmentation and the finger cleanliness factors, the combined detected error size was clinically significant. The pigmentation, ambient light, and finger cleanliness also had a significant effect on the heart rate measurement in the CMS50D model, unlike the handheld devices, which were not affected. During Phase II, neither the Nonin nor the Masimo devices were deemed to have a significant advantage.

Conclusion

Considering measurement limitations of POs used is extremely important. Use of handheld devices should be favored for use in motion conditions. Technologically advanced and/or recently developed devices should be preferred because of evolving algorithms, which decrease or eliminate the error factors. The “dirty finger” effect on the measurement error cannot be neglected and therefore the action of finger cleaning should be considered part of the treatment protocol.
Particle Analysis by Scanning Electron Microscopy With Energy Dispersive X-Ray Analysis in Pulmonary Pathology Specimens From U.S. Military Service Members Deployed During the Global War on Terror 2002 to 2015
Authors: Strausborger Stacy L , Jenkins H Marie , Franks Teri J , Lewin-Smith Michael R
Published: January 2021

Introduction

Between 2001 and 2015, 2.77 million U.S. military service members completed over 5 million deployments to Southwest Asia. There are concerns that deployment-related environmental exposures may be associated with adverse pulmonary health outcomes. Accurate pulmonary diagnosis often requires histopathological biopsy. These lung biopsies are amenable to chemical analysis of retained particulates using scanning electron microscopy with energy dispersive X-ray analysis (SEM/EDXA).

Method

A retrospective review of SEM/EDXA data collected in conjunction with pathologic diagnostic consultations at the Joint Pathology Center from 2011 to 2016 was conducted. Sections adjacent to those obtained for pathologic diagnosis were prepared for SEM/EDXA particle analysis, which provides qualitative identification of elements present in each particle and semiquantitative estimations of elemental weight percent. The review includes comparison of the particle analysis data and diagnostic findings, the particle count for the standard field analyzed, and types of particles identified.

Results

Nonneoplastic lung biopsy specimens from 25 deployed and 7 nondeployed U.S. service members were analyzed as part of the Joint Pathology Center pathologic consultations. The major exogenous particle types identified in both groups include aluminum silicates, other silicates, silica, and titanium dioxide. Endogenous particle types identified include calcium salts and iron-containing particles consistent with hemosiderin. These particles are present in deployed and nondeployed service members and are particle types commonly identified in lung biopsy specimens from urban dwelling adults. Rare particles containing other elements such as cerium and iron alloys were identified in some cases. Possible sources of these materials include diesel fuel and occupational and other environmental exposures.

Conclusion

Scanning electron microscopy with energy dispersive X-ray particle analysis of inhaled particulates retained in lung tissue from deployed service members identifies particles commonly present in inhaled dust. In this small case series, we were not able to detect particle profiles that were common and unique to deployed patients only.
Early Detection of Hypotension Using a Multivariate Machine Learning Approach
Authors: Rashedi Navid , Sun Yifei , Vaze Vikrant , Shah Parikshit , Halter Ryan , Elliott Jonathan T , Paradis Norman A
Published: January 2021

Introduction

The ability to accurately detect hypotension in trauma patients at the earliest possible time is important in improving trauma outcomes. The earlier an accurate detection can be made, the more time is available to take corrective action. Currently, there is limited research on combining multiple physiological signals for an early detection of hemorrhagic shock. We studied the viability of early detection of hypotension based on multiple physiologic signals and machine learning methods. We explored proof of concept with a small (5 minutes) prediction window for application of machine learning tools and multiple physiologic signals to detecting hypotension.

Materials and Methods

Multivariate physiological signals from a preexisting dataset generated by an experimental hemorrhage model were employed. These experiments were conducted previously by another research group and the data made available publicly through a web portal. This dataset is among the few publicly available which incorporate measurement of multiple physiological signals from large animals during experimental hemorrhage. The data included two hemorrhage studies involving eight sheep. Supervised machine learning experiments were conducted in order to develop deep learning (viz., long short-term memory or LSTM), ensemble learning (viz., random forest), and classical learning (viz., support vector machine or SVM) models for the identification of physiological signals that can detect whether or not overall blood loss exceeds a predefined threshold 5 minutes ahead of time. To evaluate the performance of the machine learning technologies, 3-fold cross-validation was conducted and precision (also called positive predictive value) and recall (also called sensitivity) values were compared. As a first step in this development process, 5 minutes prediction windows were utilized.

Results

The results showed that SVM and random forest outperform LSTM neural networks, likely because LSTM tends to overfit the data on small sized datasets. Random forest has the highest recall (84%) with 56% precision while SVM has 62% recall with 82% precision. Upon analyzing the feature importance, it was observed that electrocardiogram has the highest significance while arterial blood pressure has the least importance among all other signals.

Conclusion

In this research, we explored the viability of early detection of hypotension based on multiple signals in a preexisting animal hemorrhage dataset. The results show that a multivariate approach might be more effective than univariate approaches for this detection task.
Previous Military Medical Exposure as a Motivator for a Medical Career
Authors: Manor Uri , Allon Raviv , Gan-Or Hadar , Yahal Orr , Benov Avi , Chen Jacob
Published: January 2021

Introduction

A variety of factors influence the motivation to choose a medical career; however, the influence of premedical experiences on health professional trainees’ choices is a neglected one. We hypothesize that medical exposure during service in the Israeli Air Force special operations forces (SOFs) has an impact on motivation for medical studies. The Israeli scenario, in which career choice is anteceded by substantial military experience, allows us to examine this hypothesis.

Materials and Methods

We conducted a retrospective cohort study among physicians and medical students who served as operators in the Israeli Air Force SOF; Unit 669 (an airborne combat search and rescue unit), and Shaldag (an airborne SOF unit). All medical students and physicians enlisted between January 2001 and December 2010 were eligible for enrollment.

Results

Of over 700 operators screened, 3.7% of Shaldag veterans and 11.1% of Unit 669 veterans had started or finished medical school (P-value < 0.001). Overall, 49 veterans answered the questionnaire and enrolled in the study, of whom 17 (34.7%) were Shaldag veterans and 32 (65.3%) were Unit 669 veterans. Subjective questions implied a significant effect of the service in Unit 669 on career choice. Paramedics had a relative risk of becoming physicians of 7.37 when compared to nonparamedic operators, irrespective of their original unit.

Conclusions

Medical exposure of Unit 669 operators during military service significantly contributed to their motivation for becoming physicians. Thus, military service in this setting acts de facto as an effective medical immersion program. This adds another factor to the myriad of factors that motivate young adults in their choice of a medical career.
Point-of-Care Tomosynthesis Imaging of the Wrist
Authors: Inscoe Christina R , Lee Yueh , Billingsley Alex J , Puett Connor , Nissman Daniel , Lu Jianping , Zhou Otto
Published: January 2021

Introduction

Musculoskeletal injury to extremities is a common issue for both stateside and deployed military personnel, as well as the general public. Superposition of anatomy can make diagnosis difficult using standard clinical techniques. There is a need for increased diagnostic accuracy at the point-of-care for military personnel in both training and operational environments, as well as assessment during follow-up treatment to optimize care and expedite return to service. Orthopedic tomosynthesis is rapidly emerging as an alternative to digital radiography (DR), exhibiting an increase in sensitivity for some clinical tasks, including diagnosis and follow-up of fracture and arthritis. Commercially available digital tomosynthesis systems are large complex devices. A compact device for extremity tomosynthesis (TomoE) was previously demonstrated using carbon nanotube X-ray source array technology. The purpose of this study was to prepare and evaluate the prototype device for an Institutional Review Board-approved patient wrist imaging study and provide initial patient imaging results.

Materials and Methods

A benchtop device was constructed using a carbon nanotube X-ray source array and a flat panel digital detector. Twenty-one X-ray projection images of cadaveric specimens and human subjects were acquired at incident angles from −20 to +20 degrees in various clinical orientations, with entrance dose calibrated to commercial digital tomosynthesis wrist scans. The projection images were processed with an iterative reconstruction algorithm in 1 mm slices. Reconstruction slice images were evaluated by a radiologist for feature conspicuity and diagnostic accuracy.

Results

The TomoE image quality was found to provide more diagnostic information than DR, with reconstruction slices exhibiting delineation of joint space, visual conspicuity of trabecular bone, bone erosions, fractures, and clear depiction of normal anatomical features. The scan time was 15 seconds and the skin entrance dose was verified to be 0.2 mGy.

Conclusions

The TomoE device image quality has been evaluated using cadaveric specimens. Dose was calibrated for a patient imaging study. Initial patient images depict a high level of anatomical detail and an increase in diagnostic value compared to DR.
Purposeful Misalignment of Severed Nerve Stumps in a Standardized Transection Model Reveals Persistent Functional Deficit With Aberrant Neurofilament Distribution
Authors: Lee Jung Il , Gurjar Anagha A , Talukder M A Hassan , Rodenhouse Andrew , Manto Kristen , O’Brien Mary , Karuman Zara , Govindappa Prem Kumar , Elfar John C
Published: January 2021

Background

Functional recovery following primary nerve repair of a transected nerve is often poor even with advanced microsurgical techniques. Recently, we developed a novel sciatic nerve transection method where end-to-end apposition of the nerve endings with minimal gap was performed with fibrin glue. We demonstrated that transected nerve repair with gluing results in optimal functional recovery with improved axonal neurofilament distribution profile compared to the end-to-end micro-suture repair. However, the impact of axonal misdirection and misalignment of nerve fascicles remains largely unknown in nerve-injury recovery. We addressed this issue using a novel nerve repair model with gluing.

Methods

In our complete “Flip and Transection with Glue” model, the nerve was “first” transected to 40% of its width from each side and distal stump was transversely flipped, then 20 µL of fibrin glue was applied around the transection site and the central 20% nerve was completely transected before fibrin glue clotting. Mice were followed for 28 days with weekly assessment of sciatic function. Immunohistochemistry analysis of both sciatic nerves was performed for neurofilament distribution and angiogenesis. Tibialis anterior muscles were analyzed for atrophy and histomorphometry.

Results

Functional recovery following misaligned repair remained persistently low throughout the postsurgical period. Immunohistochemistry of nerve sections revealed significantly increased aberrant axonal neurofilaments in injured and distal nerve segments compared to proximal segments. Increased aberrant neurofilament profiles in the injured and distal nerve segments were associated with significantly increased nerve blood-vessel density and branching index than in the proximal segment. Injured limbs had significant muscle atrophy, and muscle fiber distribution showed significantly increased numbers of smaller muscle fibers and decreased numbers of larger muscle fibers.

Conclusions

These findings in a novel nerve transection mouse model with misaligned repair suggest that aberrant neurofilament distributions and axonal misdirections play an important role in functional recovery and muscle atrophy.