Headache Disorders: Differentiating Primary and Secondary Etiologies.

In the initial assessment of a headache patient, several dangerous secondary etiologies must be considered. A thorough history and physical examination, along with a comprehensive differential diagnosis may alert a physician to the diagnosis of a secondary headache particularly when it is accompanied by certain clinical features. Evaluation and workup include a complete neurological examination, consideration of neuroimaging, and serum/spinal fluid analysis if indicated. Careful attention to the patients' history and physical examination will guide the diagnostic work-up and management. In this review, we summarize the diagnostic workup of various primary and secondary headache etiologies. Although most headaches are primary in nature, it is essential to screen for headache "red flags", as they can suggest life threatening secondary etiologies. When secondary causes are suspected, appropriate neuroimaging can further differentiate the underlying cause. The appropriate imaging is dependent on the most likely secondary etiology, which is deduced from history and physical examination. When no red flags are present, primary headaches are more likely. These can be differentiated by frequency, location, duration, triggers, and presence of aura. The different clinical presentations for secondary headaches, as well as the distinguishing features for primary headaches are outlined in this review.

Twelve tips for providing academic remediation to widening access learners in medical education.

As medical schools expand access and diversity through widening access initiatives, there is an increasing need to provide academic remediation for learners during their first year in medical school. The previous educational experiences of widening access learners are often mismatched for continuing success in medical school. This article offers 12 tips for providing academic remediation to widening access learners and draws on insights from the learning sciences and research in psychosocial education to support academic development within a holistic framework.

Open-Label Placebo for the Treatment of Cancer-Related Fatigue in Patients with Advanced Cancer: A Randomized Controlled Trial.

BACKGROUND: The purpose of this study was to determine the effects of an open-labeled placebo (OLP) compared to a waitlist control (WL) in reducing cancer-related fatigue (CRF) in patients with advanced cancer using Functional Assessment of Chronic Illness Therapy-Fatigue (FACIT-F). MATERIALS AND METHODS: In this randomized controlled trial, patients with fatigue ≥4/10 on Edmonton Symptom Assessment Scale (ESAS) were randomized to OLP one tablet twice a day or WL for 7 days. On day 8, patients of both arms received a placebo for 3 weeks. Changes in FACIT-F from baseline to day 8 (primary outcome) and at day 29, were assessed. Secondary outcomes included FACT-G, Multidimensional Fatigue Symptom Inventory-SF, Fatigue cluster (defined as a composite of ESAS fatigue, pain, and depression), Center for epidemiologic studies-depression, Godin leisure-time physical activity questionnaire, and global symptom evaluation. RESULTS: A total of 84/90 (93%) patients were evaluable. The mean (SD) FACIT-F change at day 8 was 6.6 (7.6) after OLP, vs. 2.1 (9.4) after WL (P = .016). On days 15 and 29, when all patients received OLP, there was a significant improvement in CRF and no difference between arms. There was also a significant improvement in ESAS fatigue, and fatigue cluster score in the OLP arm on day 8 of the study (0.029, and 0.044, respectively). There were no significant differences in other secondary outcomes and adverse events between groups. CONCLUSIONS: Open-labeled placebo was efficacious in reducing CRF and fatigue clusters in fatigued advanced cancer patients at the end of 1 week. The improvement in fatigue was maintained for 4 weeks. Further studies are needed.

Biomechanical Parameters of Mesh Reinforcement and Analysis of a Novel Device for Incisional Hernia Prevention.

BACKGROUND: Prophylactic mesh augmentation (PMA) is an effective technique utilized to reduce the risk of incisional hernia. This study analyzes the biomechanical characteristics of a mesh-reinforced closure and evaluates a novel prophylactic mesh implantation device (SafeClose Roller System; SRS). MATERIALS AND METHODS: A total of eight senior-level general surgery trainees (≥4 years of training) from the University of Pennsylvania Health System participated in the study. Biomechanical strength, mesh stiffness, mesh uniformity, and time efficiency for fixation were compared among hand-sewn mesh fixation, SRS mesh fixation and a no-mesh fixation control. Porcine abdominal wall specimens served as simulated laparotomy models. RESULTS: Biomechanical load strength was significantly higher for mesh reinforced repairs (P = 0.009). The SRS resulted in a stronger biomechanical force than hand-sewn mesh (21.2 N stronger, P = 0.317), with more uniform mesh placement (P < 0.01), faster time of fixation (P < 0.001) and with less discrete hand-movements (P < 0.001). CONCLUSIONS: Mesh reinforcement for incisional reinforcement has a significant impact on the strength of the closure. The utilization of a mesh-application system has the potential to amplify the advantages of mesh reinforcement by providing efficiency and consistency to fixation methods, with similar biomechanical strength to hand-sewn mesh. Additional in vivo analysis and randomized controlled trials are needed to further assess clinical efficacy.

Determinants of Long-Term Neurological Recovery Patterns Relative to Hospital Discharge Among Cardiac Arrest Survivors.

OBJECTIVE: To explore factors associated with neurological recovery at 1 year relative to hospital discharge after cardiac arrest. DESIGN: Observational, retrospective review of a prospectively collected cohort. SETTING: Medical or surgical ICUs in a single tertiary care center. PATIENTS: Older than 18 years, resuscitated following either in-hospital or out-of-hospital cardiac arrest and considered for targeted temperature management between 2007 and 2013. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Logistic regressions to determine factors associated with a poor recovery pattern after 1 year, defined as persistent Cerebral Performance Category Score 3-4 or any worsening of Cerebral Performance Category Score relative to discharge status. In total, 30% (117/385) of patients survived to hospital discharge; among those discharged with Cerebral Performance Category Score 1, 2, 3, and 4, good recovery pattern was seen in 54.5%, 48.4%, 39.5%, and 0%, respectively. Significant variables showing trends in associations with a poor recovery pattern (62.5%) in a multivariate model were age more than 70 years (odds ratio, 4; 95% CIs, 1.1-15; p = 0.04), Hispanic ethnicity (odds ratio, 4; CI, 1.2-13; p = 0.02), and discharge disposition (home needing out-patient services (odds ratio, 1), home requiring no additional services (odds ratio, 0.15; CI, 0.03-0.8; p = 0.02), acute rehabilitation (odds ratio, 0.23; CI, 0.06-0.9; p = 0.04). CONCLUSIONS: Patients discharged with mild or moderate cerebral dysfunction sustained their risk of neurological worsening within 1 year of cardiac arrest. Old age, Hispanic ethnicity, and discharge disposition of home with out-patient services may be associated with a poor 1 year neurological recovery pattern after hospital discharge from cardiac arrest.

Effects of inhaled aerosolized carfentanil on real-time physiological responses in mice: a preliminary evaluation of naloxone.

This study examined the real-time exposure-response effects of aerosolized carfentanil (CRF) on opioid-induced toxicity, respiratory dynamics and cardiac function in mice. Unrestrained, conscious male CD-1 mice (25-30 g) were exposed to 0.4 or 4.0 mg/m3 of aerosolized CRF for 15 min (Ct = 6 or 60 mg min/m3) in a whole-body plethysmograph chamber. Minute volume (MV), core body temperature (Tc), mean arterial blood pressure (MAP) and heart rate (HR) were evaluated in animals exposed to CRF or sterile H2O. Loss of consciousness and Straub tail were observed in before 1 min following initiation of exposure to 6 or 60 mg min/m3 of CRF. Clinical signs of opioid-induced toxicity were observed in a dose-dependent manner. Exposure to 6 or 60 mg min/m3 of CRF resulted in significant decrease in MV as compared to the controls. MAP, HR and Tc decreased 24 h in animals exposed to either 6 or 60 mg min/m3 of CRF as compared to the controls. Post-exposure administration of naloxone (NX, 0.05 mg/kg, i.m.) did not increase the MV of animals exposed to CRF to control levels within 24 h, but decreased clinical signs of opioid-induced toxicity and the duration of respiratory depression. This is the first study to evaluate real-time respiratory dynamics and cardiac function during exposure and up to 24 h post-exposure to CRF. The evaluation of toxicological signs and respiratory dynamics following exposure to CRF will be useful in the development of therapeutic strategies to counteract the ongoing threat of abuse and overuse of opioids and their synthetic variants.

Adverse respiratory effects in rats following inhalation exposure to ammonia: respiratory dynamics and histopathology.

Acute respiratory dynamics and histopathology of the lungs and trachea following inhaled exposure to ammonia were investigated. Respiratory dynamic parameters were collected from male Sprague-Dawley rats (300-350 g) during (20 min) and 24 h (10 min) after inhalation exposure for 20 min to 9000, 20,000, and 23,000 ppm of ammonia in a head-only exposure system. Body weight loss, analysis of blood cells, and lungs and trachea histopathology were assessed 1, 3, and 24 h following inhalation exposure to 20,000 ppm of ammonia. Prominent decreases in minute volume (MV) and tidal volume (TV) were observed during and 24 h post-exposure in all ammonia-exposed animals. Inspiratory time (IT) and expiratory time (ET) followed similar patterns and decreased significantly during the exposure and then increased at 24 h post-exposure in all ammonia-exposed animals in comparison to air-exposed controls. Peak inspiratory (PIF) and expiratory flow (PEF) significantly decreased during the exposure to all ammonia doses, while at 24 h post-exposure they remained significantly decreased following exposure to 20,000 and 23,000 ppm. Exposure to 20,000 ppm of ammonia resulted in body weight loss at 1 and 3 h post-exposure; weight loss was significant at 24 h compared to controls. Exposure to 20,000 ppm of ammonia for 20 min resulted in increases in the total blood cell counts of white blood cells, neutrophils, and platelets at 1, 3, and 24 h post-exposure. Histopathologic evaluation of the lungs and trachea tissue of animals exposed to 20,000 ppm of ammonia at 1, 3, and 24 h post-exposure revealed various morphological changes, including alveolar, bronchial, and tracheal edema, epithelial necrosis, and exudate consisting of fibrin, hemorrhage, and inflammatory cells. The various alterations in respiratory dynamics and damage to the respiratory system observed in this study further emphasize ammonia-induced respiratory toxicity and the relevance of efficacious medical countermeasure strategies.

Assessment of inhaled acute ammonia-induced lung injury in rats.

This study examined acute toxicity and lung injury following inhalation exposure to ammonia. Male Sprague-Dawley rats (300-350 g) were exposed to 9000, 20,000, 23,000, 26,000, 30,000 or 35,000 ppm of ammonia for 20 min in a custom head-out exposure system. The exposure atmosphere, which attained steady state within 3 min for all ammonia concentrations, was monitored and verified using a Fourier transform infrared spectroscopy (FTIR) gas analyzer. Animals exposed to ammonia resulted in dose-dependent increases in observed signs of intoxication, including increased chewing and licking, ocular irritation, salivation, lacrimation, oronasal secretion and labored breathing. The LCt50 of ammonia within this head-out inhalation exposure model was determined by probit analysis to be 23,672 ppm (16,489 mg/m(3)) for the 20 min exposure in male rats. Exposure to 20,000 or 23,000 ppm of ammonia resulted in significant body weight loss 24-h post-exposure. Lung edema increased in all ammonia-exposed animal groups and was significant following exposure to 9000 ppm. Bronchoalveolar fluid (BALF) protein concentrations significantly increased following exposure to 20,000 or 23,000 ppm of ammonia in comparison to controls. BAL cell (BALC) death and total cell counts increased in animals exposed to 20,000 or 23,000 ppm of ammonia in comparison to controls. Differential cell counts of white blood cells, neutrophils and platelets from blood and BALF were significantly increased following exposure to 23,000 ppm of ammonia. The following studies describe the validation of a head-out inhalation exposure model for the determination of acute ammonia-induced toxicity; this model will be used for the development and evaluation of potential therapies that provide protection against respiratory and systemic toxicological effects.

Vapor inhalation exposure to soman in conscious untreated rats: preliminary assessment of neurotoxicity.

Neurological toxicity and brain injury following vapor inhalation exposure to the chemical warfare nerve agent (CWNA) soman (GD) were examined in untreated non-anesthetized rats. In this study, male Sprague-Dawley rats (300-350 g) were exposed to 600 mg × min/m(3) of soman or vehicle in a customized head-out inhalation system for 7 min. Convulsant animals were observed for clinical signs and various regions of the brain (dorsolateral thalamus, basolateral amygdala, piriform cortex, and lateral cortex) were collected for pathological observations 24 h post-exposure. Signs of CWNA-induced cholinergic crises including salivation, lacrimation, increased urination and defecation, and tremors were observed in all soman-exposed animals. Soman-exposed animals at 24 h post-exposure lost 11% of their body weight in comparison to 2% in vehicle-exposed animals. Whole blood acetylcholinesterase (AChE) activity was significantly inhibited in all soman-exposed groups in comparison to controls. Brain injury was confirmed by the neurological assessment of hematoxylin-eosin (H&E) staining and microscopy in the piriform cortex, dorsolateral thalamus, basolateral amygdala, and lateral cortex. Severe damage including prominent lesions, edematous, congested, and/or hemorrhagic tissues was observed in the piriform cortex, dorsolateral thalamus, and lateral cortex in soman-exposed animals 24 h post-exposure, while only minimal damage was observed in the basolateral amygdala. These results indicate that inhalation exposure to soman vapor causes neurological toxicity and brain injury in untreated unanesthetized rats. This study demonstrates the ability of the described soman vapor inhalation exposure model to cause neurological damage 24 h post-exposure in rats.

Measurement of various respiratory dynamics parameters following acute inhalational exposure to soman vapor in conscious rats.

Respiratory dynamics were investigated in head-out plethysmography chambers following inhalational exposure to soman in untreated, non-anesthetized rats. A multipass saturator cell was used to generate 520, 560 and 600 mg × min/m(3) of soman vapor in a customized inhalational exposure system. Various respiratory dynamic parameters were collected from male Sprague-Dawley rats (300--350 g) during (20 min) and 24 h (10 min) after inhalational exposure. Signs of CWNA-induced cholinergic crisis were observed in all soman-exposed animals. Percentage body weight loss and lung edema were observed in all soman-exposed animals, with significant increases in both at 24 h following exposure to 600 mg × min/m(3). Exposure to soman resulted in increases in respiratory frequency (RF) in animals exposed to 560 and 600 mg × min/m(3) with significant increases following exposure to 560 mg × min/m(3) at 24 h. No significant alterations in inspiratory time (IT) or expiratory time (ET) were observed in soman-exposed animals 24 h post-exposure. Prominent increases in tidal volume (TV) and minute volume (MV) were observed at 24 h post-exposure in animals exposed to 600 mg × min/m(3). Peak inspiratory (PIF) and expiratory flow (PEF) followed similar patterns and increased 24 h post-exposure to 600 mg × min/m(3) of soman. Results demonstrate that inhalational exposure to 600 mg × min/m(3) soman produces notable alterations in various respiratory dynamic parameters at 24 h. The following multitude of physiological changes in respiratory dynamics highlights the need to develop countermeasures that protect against respiratory toxicity and lung injury.

Analysis of differential gene expression profiles in Caenorhabditis elegans knockouts for the v-SNARE master protein 1.

At chemical synapses, neurons communicate information to other cells by secreting neurotransmitters or neuropeptides into the synaptic cleft, which then bind to receptors on the target cell. Preliminary work performed in our laboratory has shown that mutant nematodes lacking a protein called VSM-1 have increased synaptic density compared with the wild type. Consequently, we hypothesized that genes expressed in vsm-1 mutants mediate enhanced synaptogenesis. To identify these genes of interest, we utilized microarray technology and quantitative PCR. To this end, first we isolated the total RNA from young-adult wild-type and vsm-1 mutant Caenorhabditis elegans. Next, we synthesized cDNA from reverse transcription of the isolated RNA. Hybridization of the cDNA to a microarray was performed to facilitate gene expression profiling. Finally, fluorescently labeled microarrays were analyzed, and the identities of induced and repressed genes were uncovered in the open-source software Magic Tool. Analyses of microarray experiments performed using three independent biological samples per strain and three technical replicas and dye swaps showed induction of genes coding for major sperm proteins and repression of SPP-2 in vsm-1 mutants. Microarray results were also validated and quantified by using quantitative PCR.

Acute pulmonary toxicity following inhalation exposure to aerosolized VX in anesthetized rats.

This study evaluated acute toxicity and pulmonary injury in rats at 3, 6 and 24 h after an inhalation exposure to aerosolized O-ethyl S-[2-(diisopropylamino)ethyl] methylphosphonothioate (VX). Anesthetized male Sprague-Dawley rats (250-300 g) were incubated with a glass endotracheal tube and exposed to saline or VX (171, 343 and 514 mg×min/m³ or 0.2, 0.5 and 0.8 LCt50, respectively) for 10 min. VX was delivered by a small animal ventilator at a volume of 2.5 ml × 70 breaths/minute. All VX-exposed animals experienced a significant loss in percentage body weight at 3, 6, and 24 h post-exposure. In comparison to controls, animals exposed to 514 mg×min/m³ of VX had significant increases in bronchoalveolar lavage (BAL) protein concentrations at 6 and 24 h post-exposure. Blood acetylcholinesterase (AChE) activity was inhibited dose dependently at each of the times points for all VX-exposed groups. AChE activity in lung homogenates was significantly inhibited in all VX-exposed groups at each time point. All VX-exposed animals assessed at 20 min and 3, 6 and 24 h post-exposure showed increases in lung resistance, which was prominent at 20 min and 3 h post-exposure. Histopathologic evaluation of lung tissue of the 514 mg×min/m³ VX-exposed animals at 3, 6 and 24 h indicated morphological changes, including perivascular inflammation, alveolar exudate and histiocytosis, alveolar septal inflammation and edema, alveolar epithelial necrosis, and bronchiolar inflammatory infiltrates, in comparison to controls. These results suggest that aerosolization of the highly toxic, persistent chemical warfare nerve agent VX results in acute pulmonary toxicity and lung injury in rats.

Telehealth Preferences Among Patients With Advanced Cancer in the Post COVID-19 Vaccine Era.

BACKGROUND: Few studies have examined patient preferences for telehealth in palliative care after the availability of COVID-19 vaccines. We examined patient preferences for video versus in-person visits and factors contributing to preferences in the postvaccine era. METHODS: This is a cross-sectional survey of patients who were seen at our palliative care clinic between April 2021 and March 2022. Patients were surveyed directly their preference for either video or in-person visits for outpatient palliative care (primary outcome). We also surveyed preferences including convenience, cost, wait time, and perceptions of COVID-19 safety regarding their palliative virtual-video visit. We examined clinical factors associated with preferences with multivariate logistic regression. RESULTS: About 200 patients completed the survey. 132 (67%, 95% confidence interval [CI]: 60%, 74%) preferred virtual-video, while 16 (8%) preferred in-person visits during the COVID-19 pandemic. About 120 (61%, 95%CI: 54%, 68%) preferred virtual-video after the pandemic. Patients perceived virtual-video favorably regarding travel and related costs (179 [91%]), convenience (175 [88%]), and wait time (136 [69%]). Multivariable analysis showed concerns for catching COVID-19 from healthcare providers (odds ratio [OR]: 4.20; 95%CI: 1.24-14.25; P = 0.02) and feeling comfortable with computers or mobile devices (OR: 4.59; 95%CI: 1.02, 20.60; P = 0.047) were significantly associated with preferring virtual-video. Patients who were of Hispanic or Latino ethnicity (OR: 0.25; 95%CI: 0.09, 0.71) and had increased dypsnea (OR: 0.74; 95%CI: 0.59, 0.93) were less likely to prefer video over in-person. CONCLUSION: Patients expressed strong preference for video over in-person visits in the outpatient palliative care setting.

Development of a model for nerve agent inhalation in conscious rats.

This study characterizes the development of a head-out inhalation exposure system for assessing respiratory toxicity of vaporized chemical agents in untreated, non-anesthetized rats. The organophosphate diisopropyl fluorophosphate (DFP) induces classical cholinergic toxicity following inhalation exposure and was utilized to validate the effectiveness of this newly designed inhalation exposure system. A saturator cell apparatus was used to generate DFP vapor at 9750, 10,950, 12,200, 14,625 and 19,500 mg × min/m³ which was carried by filtered nitrogen into a glass mixing tube, where it combined with ambient air before being introduced to the custom-made glass exposure chamber. Male Sprague-Dawley rats (250-300 g) were restrained in individual head-out plethysmography chambers, which acquired respiratory parameters before, during and after agent exposure. All animals were acclimated to the exposure system prior to exposure to reduce novel environment-induced stress. The LCt50, as determined by probit analysis, was 12,014 mg × min/m³. Weight loss in exposed animals was dose-dependent and ranged from 8 to 28% of their body weight 24 h after exposure. Increased salivation, lacrimation, urination, defecation (SLUD) and mild muscular fasciculation were observed in all DFP-exposed animals during and immediately following exposure. In all exposed animals, DFP vapor produced significant inhibition of acetylcholinesterase (AChE) activity in cardiac blood, bronchoalveolar lavage fluid (BALF), whole brain and lung tissue as well as alterations in tidal volume and minute volume. These studies have provided valuable information leading to the initiation of studies evaluating inhalational toxicity and treatments following exposure to the more lethal and potent chemical warfare nerve agents.

"Community health workers bring value and deserve to be valued too:" Key considerations in improving CHW career advancement opportunities.

Introduction: Community health workers (CHWs) are critical members of the public health workforce, who connect the individuals they serve with resources, advocate for communities facing health and racial inequities, and improve the quality of healthcare. However, there are typically limited professional and career building pathways for CHWs, which contribute to low wages and lack of career advancement, further resulting in turnover, attrition, and workforce instability. Methods: The Center for Community Health Alignment (CCHA), within the Arnold School of Public Health at the University of South Carolina, utilized a mixed-method data collection strategy to provide a more in-depth understanding of this issue and ways that employers, advocates, and CHWs can address it. Results: Themes across data sources emphasized the importance of retaining skilled and experienced CHWs and educating other health professions about CHWs' critical roles, and reported that doing so will result in decreased attrition professional growth, and improved program quality. CHWs and allies concluded that higher wages, valuing lived experience over formal education, and participation in additional training opportunities should be the primary factors considered for career advancement. Discussion: Utilizing input from experienced CHWs and CHW allies nationally, this article describes the importance of supporting CHW career advancement, shares best practices, and suggestions for designing strategies that organizations/employers can use to improve CHW career pathways to better support the CHW workforce and reduce attrition.

Postvaccine Era COVID-19 Pandemic-Related Distress in Palliative Care Patients With Advanced Cancer.

CONTEXT: The COVID-19 pandemic represents a source of distress in patients with advanced cancer; however, few studies have examined the extent of pandemic-related distress in the postvaccine era. OBJECTIVES: We conducted a cross-sectional survey to examine pandemic-related distress among patients seen by palliative care after vaccine availability. METHODS: Patients at our palliative care clinic were surveyed from April 2021 to March 2022 regarding 1) pandemic-related distress level, 2) potential contributors to pandemic-related distress, 3) coping strategies, 4) demographic factors and symptom burden. Univariate and multivariate analyses identified factors associated with pandemic-related distress. RESULTS: A total of 200 patients completed the survey. Of 79 (40%, 95% confidence interval [CI]: 33%, 46%) reported worse pandemic-related distress. Patients who reported greater distress were more likely to report worse social isolation (67 [86%] vs. 52 [43%]), staying home more often (75 [95%] vs. 95 [79%]), more negative experience staying at home (26 [33%] vs. 11 [9%]), worse stress with child-care duties (14 [19%] vs. 4 [3%]), less seeing family/friends (63 [81%] vs. 72 [60%]), and more difficulty traveling to medical appointments (27 [35%] vs. 20 [17%]). Thirty-seven patients (19%) reported more difficulty getting medical appointments. In multivariable analysis, younger age (odds ratio [OR], 0.97; 95% CI, 0.92-0.99; P = 0.01), worse isolation status (OR, 6.87; 95% CI, 2.76-17.12; P < 0.001), and more negative attitude towards staying home (OR, 4.49; 95% CI, 1.6-12.57; P = 0.004) were associated with pandemic-related distress. CONCLUSIONS: Patients with advanced cancer continued to experience pandemic-related distress in the postvaccine era. Our findings highlight potential opportunities to support patients.

Increasing Vascular Response to Injury Improves Tendon Early Healing Outcome in Aged Rats.

Tendon injuries positively correlate with patient age, as aging has significant effects on tendon homeostatic maintenance and healing potential after injury. Vascularity is also influenced by age, with both clinical and animal studies demonstrating reduced blood flow in aged tissues. However, it is unknown how aging effects vascularity following tendon injury, and if this vascular response can be modulated through the delivery of angiogenic factors. Therefore, the objective of this study is to evaluate the vascular response following Achilles tendon injury in adult and aged rats, and to define the alterations to tendon healing in an aged model following injection of angiogenic factors. It was determined that aged rat Achilles tendons have a reduced angiogenesis following injury. Further, the delivery of vascular endothelial growth factor, VEGF, caused an increase in vascular response to tendon injury and improved mechanical outcome in this aged population. This work suggests that reduced angiogenic potential with aging may be contributing to impaired tendon healing response and that the delivery of angiogenic factors can rescue this impaired response. This study was also the first to relate changes in vascular response in an aged model using in vivo measures of blood perfusion to alterations in healing properties.

Decorin knockdown is beneficial for aged tendons in the presence of biglycan expression.

Decorin and biglycan are two major small leucine-rich proteoglycans (SLRPs) present in the tendon extracellular matrix that facilitate collagen fibrillogenesis, tissue turnover, and cell signal transduction. Previously, we demonstrated that knockout of decorin prevented the decline of tendon mechanical properties that are associated with aging. The objective of this study was to determine the effects of decorin and biglycan knockdown on tendon structure and mechanics in aged tendons using tamoxifen-inducible knockdown models. We hypothesized that the knockdown of decorin and compound knockdown of decorin and biglycan would prevent age-related declines in tendon mechanics and structure compared to biglycan knockdown and wild-type controls, and that these changes would be exacerbated as the tendons progress towards geriatric ages. To achieve this objective, we created tamoxifen-inducible mouse knockdown models to target decorin and biglycan gene inactivation without the abnormal tendon development associated with traditional knockout models. Knockdown of decorin led to increased midsubstance modulus and decreased stress relaxation in aged tendons. However, these changes were not sustained in the geriatric tendons. Knockdown in biglycan led to no changes in mechanics in the aged or geriatric tendons. Contrary to our hypothesis, the compound decorin/biglycan knockdown tendons did not resemble the decorin knockdown tendons, but resulted in increased viscoelastic properties in the aged and geriatric tendons. Structurally, knockdown of SLRPs, except for the 570d I-Dcn -/- /Bgn -/- group, resulted in alterations to the collagen fibril diameter relative to wild-type controls. Overall, this study identified the differential roles of decorin and biglycan throughout tendon aging in the maintenance of tendon structural and mechanical properties and revealed that the compound decorin and biglycan knockdown phenotype did not resemble the single gene decorin or biglycan models and was detrimental to tendon properties throughout aging.

Biglycan has a major role in maintenance of mature tendon mechanics.

Decorin and biglycan are two small leucine-rich proteoglycans (SLRPs) that regulate collagen fibrillogenesis and extracellular matrix assembly in tendon. The objective of this study was to determine the individual roles of these molecules in maintaining the structural and mechanical properties of tendon during homeostasis in mature mice. We hypothesized that knockdown of decorin in mature tendons would result in detrimental changes to tendon structure and mechanics while knockdown of biglycan would have a minor effect on these parameters. To achieve this objective, we created tamoxifen-inducible mouse knockdown models targeting decorin or biglycan inactivation. This enables the evaluation of the roles of these SLRPs in mature tendon without the abnormal tendon development caused by conventional knockout models. Contrary to our hypothesis, knockdown of decorin resulted in minor alterations to tendon structure and no changes to mechanics while knockdown of biglycan resulted in broad changes to tendon structure and mechanics. Specifically, knockdown of biglycan resulted in reduced insertion modulus, maximum stress, dynamic modulus, stress relaxation, and increased collagen fiber realignment during loading. Knockdown of decorin and biglycan produced similar changes to tendon microstructure by increasing the collagen fibril diameter relative to wild-type controls. Biglycan knockdown also decreased the cell nuclear aspect ratio, indicating a more spindle-like nuclear shape. Overall, the extensive changes to tendon structure and mechanics after knockdown of biglycan, but not decorin, provides evidence that biglycan plays a major role in the maintenance of tendon structure and mechanics in mature mice during homeostasis.

Understanding unidentified human remains investigations through the United States census data.

Each year, thousands of unidentified human remains (UHR) cases are reported in the U.S. Technological advances have greatly enhanced the forensic community's capacity and capability to solve UHR cases, but little is known about the extent to which these resources are used by medical examiners and coroners (MECs). Using public datasets, the study purpose is to describe the current state MEC system with respect to UHR cases, the resources used to investigate these cases, and the evidence retention polices in place. There was an overall decline in UHR cases reported between 2004 and 2018. Less than half of MECs in both study years reported having established written final disposition and evidence retention policies for UHR cases. National missing persons databases were underused. This study provides an important window into the present state of UHRs being handled by our Nation's MEC offices and the resources available to solve these difficult cases.