Trauma surgical skill sustainment at the University of Chicago AMEDD Military-Civilian Trauma Team Training Site: an observation report.

Background: The Army Medical Department (AMEDD) Military-Civilian Trauma Team Training (AMCT3) Program was developed to enhance the trauma competency and capability of the medical force by embedding providers at busy civilian trauma centers. Few reports have been published on the outcomes of this program since its implementation. Methods: The medical and billing records for the two AMCT3 embedded trauma surgeons at the single medical center were retrospectively reviewed for care provided during August 2021 through July 2022. Abstracted data included tasks met under the Army's Individual Critical Task List (ICTL) for general surgeons. The Knowledge, Skills, and Abilities (KSA) score was estimated based on previously reported point values for procedures. To assess for successful integration of the embedded surgeons, data were also abstracted for two newly hired civilian trauma surgeons. Results: The annual clinical activity for the first AMCT3 surgeon included 444 trauma evaluations and 185 operative cases. The operative cases included 80 laparotomies, 15 thoracotomies, and 15 vascular exposures. The operative volume resulted in a KSA score of 21 998 points. The annual clinical activity for the second AMCT3 surgeon included 424 trauma evaluations and 194 operative cases. The operative cases included 92 laparotomies, 8 thoracotomies, and 25 vascular exposures. The operative volume resulted in a KSA score of 22 799 points. The first civilian surgeon's annual clinical activity included 453 trauma evaluations and 151 operative cases, resulting in a KSA score of 16 738 points. The second civilian surgeon's annual clinical activity included 206 trauma evaluations and 96 operative cases, resulting in a KSA score of 11 156 points. Conclusion: The AMCT3 partnership at this single center greatly exceeds the minimum deployment readiness metrics established in the ICTLs and KSAs for deploying general surgeons. The AMEDD experience provided a deployment-relevant case mix with an emphasis on complex vascular injury repairs.

Proteomic profiling of interferon-responsive reactive astrocytes in rodent and human.

Astrocytes are a heterogeneous population of central nervous system glial cells that respond to pathological insults and injury by undergoing a transformation called "reactivity." Reactive astrocytes exhibit distinct and context-dependent cellular, molecular, and functional state changes that can either support or disturb tissue homeostasis. We recently identified a reactive astrocyte sub-state defined by interferon-responsive genes like Igtp, Ifit3, Mx1, and others, called interferon-responsive reactive astrocytes (IRRAs). To further this transcriptomic definition of IRRAs, we wanted to define the proteomic changes that occur in this reactive sub-state. We induced IRRAs in immunopanned rodent astrocytes and human iPSC-differentiated astrocytes using TNF, IL1α, C1Q, and IFNß and characterized their proteomic profile (both cellular and secreted) using unbiased quantitative proteomics. We identified 2335 unique cellular proteins, including IFIT2/3, IFITM3, OASL1/2, MX1/2/3, and STAT1. We also report that rodent and human IRRAs secrete PAI1, a serine protease inhibitor which may influence reactive states and functions of nearby cells. Finally, we evaluated how IRRAs are distinct from neurotoxic reactive astrocytes (NRAs). While NRAs are described by expression of the complement protein C3, it was not upregulated in IRRAs. Instead, we found ~90 proteins unique to IRRAs not identified in NRAs, including OAS1A, IFIT3, and MX1. Interferon signaling in astrocytes is critical for the antiviral immune response and for regulating synaptic plasticity and glutamate transport mechanisms. How IRRAs contribute to these functions is unknown. This study provides the basis for future experiments to define the functional roles of IRRAs in the context of neurodegenerative disorders.

Transarterial interventions in civilian gunshot wound injury: experience from a level-1 trauma center.

PURPOSE: To assess the effectiveness of trans-arterial vascular interventions in treatment of civilian gunshot wounds (GSW). MATERIALS AND METHODS: A retrospective review was performed at a level-1 trauma center to include 46 consecutive adults admitted due to GSW related hemorrhage and treated with endovascular interventions from July 2018 to July 2022. Patient demographics and procedural metrics were retrieved. Primary outcomes of interest include technical success and in-hospital mortality. Factors of mortality were assessed using a logistic regression model. RESULTS: Twenty-one patients were brought to the endovascular suite directly (endovascular group) from the trauma bay and 25 patients after treatment in the operating room (OR group). The OR group had higher hemodynamic instability (48.0% vs 19.0%, p = 0.040), lower hemoglobin (12.9 vs 10.1, p = 0.001) and platelet counts (235.2 vs 155.1, p = 0.003), and worse Acute Physiology and Chronic Health Evaluation (APACHE) score (4.1 vs 10.2, p < 0.0001) at the time of initial presentation. Technical success was achieved in all 40 cases in which targeted embolization was attempted (100%). Empiric embolization was performed in 6/46 (13.0%) patients based on computed tomographic angiogram (CTA) and operative findings. Stent-grafts were placed in 3 patients for subclavian artery injuries. Availability of pre-intervention CTA was associated with shorter fluoroscopy time (19.8 ± 12.1 vs 30.7 ± 18.6 min, p = 0.030). A total of 41 patients were discharged in stable condition (89.1%). Hollow organ injury was associated with mortality (p = 0.039). CONCLUSION: Endovascular embolization and stenting were effective in managing hemorrhage due to GSW in a carefully selected population. Hollow organ injury was a statistically significant predictor of mortality. Pre-intervention CTA enabled targeted, shorter and equally effective procedures.

Amyloid ß Induces Lipid Droplet-Mediated Microglial Dysfunction in Alzheimer's Disease.

Several microglia-expressed genes have emerged as top risk variants for Alzheimer's disease (AD). Impaired microglial phagocytosis is one of the main proposed outcomes by which these AD-risk genes may contribute to neurodegeneration, but the mechanisms translating genetic association to cellular dysfunction remain unknown. Here we show that microglia form lipid droplets (LDs) upon exposure to amyloid-beta (Aß), and that their LD load increases with proximity to amyloid plaques in brains from human patients and the AD mouse model 5xFAD. LD formation is dependent upon age and disease progression and is more prominent in the hippocampus in mice and humans. Despite variability in LD load between microglia from male versus female animals and between cells from different brain regions, LD-laden microglia exhibited a deficit in Aß phagocytosis. Unbiased lipidomic analysis identified a substantial decrease in free fatty acids (FFAs) and a parallel increase in triacylglycerols (TAGs) as the key metabolic transition underlying LD formation. We demonstrate that DGAT2, a key enzyme for the conversion of FFAs to TAGs, promotes microglial LD formation, is increased in microglia from 5xFAD and human AD brains, and that inhibiting DGAT2 improved microglial uptake of Aß. These findings identify a new lipid-mediated mechanism underlying microglial dysfunction that could become a novel therapeutic target for AD.

Proteomic Alterations and Novel Markers of Neurotoxic Reactive Astrocytes in Human Induced Pluripotent Stem Cell Models.

Astrocytes respond to injury, infection, and inflammation in the central nervous system by acquiring reactive states in which they may become dysfunctional and contribute to disease pathology. A sub-state of reactive astrocytes induced by proinflammatory factors TNF, IL-1α, and C1q ("TIC") has been implicated in many neurodegenerative diseases as a source of neurotoxicity. Here, we used an established human induced pluripotent stem cell (hiPSC) model to investigate the surface marker profile and proteome of TIC-induced reactive astrocytes. We propose VCAM1, BST2, ICOSL, HLA-E, PD-L1, and PDPN as putative, novel markers of this reactive sub-state. We found that several of these markers colocalize with GFAP+ cells in post-mortem samples from people with Alzheimer's disease. Moreover, our whole-cells proteomic analysis of TIC-induced reactive astrocytes identified proteins and related pathways primarily linked to potential engagement with peripheral immune cells. Taken together, our findings will serve as new tools to purify reactive astrocyte subtypes and to further explore their involvement in immune responses associated with injury and disease.

One Scaffold, Different Organelle Sensors: pH-Activable Fluorescent Probes for Targeting Live Microglial Cell Organelles.

Targeting live cell organelles is essential for imaging, understanding, and controlling specific biochemical processes. Typically, fluorescent probes with distinct structural scaffolds are used to target specific cell organelles. Here, we have designed a modular one-step synthetic strategy using a common reaction intermediate to develop new lysosomal, mitochondrial, and nucleus-targeting pH-activable fluorescent probes that are all based on a single boron dipyrromethane scaffold. The divergent cell organelle targeting was achieved by synthesizing probes with specific functional group changes to the central scaffold resulting in differential fluorescence and pKa . Specifically, we show that the functional group transformation of the same scaffold influences cellular localization and specificity of pH-activable fluorescent probes in live primary microglial cells with pKa values ranging from ∼3.2-6.0. We introduce a structure-organelle-relationship (SOR) framework to target nuclei (NucShine), lysosomes (LysoShine), and mitochondria (MitoShine) in live microglia. This work will result in future applications of SOR beyond imaging to target and control organelle-specific biochemical processes in disease-specific models.

Neurotoxic reactive astrocytes induce cell death via saturated lipids.

Astrocytes regulate the response of the central nervous system to disease and injury and have been hypothesized to actively kill neurons in neurodegenerative disease1-6. Here we report an approach to isolate one component of the long-sought astrocyte-derived toxic factor5,6. Notably, instead of a protein, saturated lipids contained in APOE and APOJ lipoparticles mediate astrocyte-induced toxicity. Eliminating the formation of long-chain saturated lipids by astrocyte-specific knockout of the saturated lipid synthesis enzyme ELOVL1 mitigates astrocyte-mediated toxicity in vitro as well as in a model of acute axonal injury in vivo. These results suggest a mechanism by which astrocytes kill cells in the central nervous system.

Monitoring phagocytic uptake of amyloid ß into glial cell lysosomes in real time.

Phagocytosis by glial cells is essential to regulate brain function during health and disease. Therapies for Alzheimer's disease (AD) have primarily focused on targeting antibodies to amyloid ß (Aß) or inhibitng enzymes that make it, and while removal of Aß by phagocytosis is protective early in AD it remains poorly understood. Impaired phagocytic function of glial cells during later stages of AD likely contributes to worsened disease outcome, but the underlying mechanisms of how this occurs remain unknown. We have developed a human Aß1-42 analogue (AßpH) that exhibits green fluorescence upon internalization into the acidic organelles of cells but is non-fluorescent at physiological pH. This allowed us to image, for the first time, glial uptake of AßpH in real time in live animals. We find that microglia phagocytose more AßpH than astrocytes in culture, in brain slices and in vivo. AßpH can be used to investigate the phagocytic mechanisms responsible for removing Aß from the extracellular space, and thus could become a useful tool to study Aß clearance at different stages of AD.

Prevalence and phenotype associations of complement factor I mutations in geographic atrophy.

Rare variants in the complement factor I (CFI) gene, associated with low serum factor I (FI) levels, are strong risk factors for developing the advanced stages of age-related macular degeneration (AMD). No studies have been undertaken on the prevalence of disease-causing CFI mutations in patients with geographic atrophy (GA) secondary to AMD. A multicenter, cross-sectional, noninterventional study was undertaken to identify the prevalence of pathogenic rare CFI gene variants in an unselected cohort of patients with GA and low FI levels. A genotype-phenotype study was performed. Four hundred and sixty-eight patients with GA secondary to AMD were recruited to the study, and 19.4% (n = 91) demonstrated a low serum FI concentration (below 15.6 µg/ml). CFI gene sequencing on these patients resulted in the detection of rare CFI variants in 4.7% (n = 22) of recruited patients. The prevalence of CFI variants in patients with low serum FI levels and GA was 25%. Of the total patients recruited, 3.2% (n = 15) expressed a CFI variant classified as pathogenic or likely pathogenic. The presence of reticular pseudodrusen was detected in all patients with pathogenic CFI gene variants. Patients with pathogenic CFI gene variants and low serum FI levels might be suitable for FI supplementation in therapeutic trials.

The Ethics and Politics of Gun Violence Research.

Gun violence is an epidemic that affects hundreds of thousands of Americans each year. Despite gun violence being disproportionately more lethal than other leading causes of trauma, there is a dearth of research being carried out on its root causes and prevention strategies. For the past 20 years, lobbying and politics have interfered with the forward progress of gun violence research. Physicians have a history of producing actionable public-health change and have an ethical obligation to fight for the research that will benefit their patients.

The Effect of Inorganic and Organic Zinc Supplementation on Growth Performance, Mineral Profile and Gene Expression Pattern of GLUT1 in Malabari Kids.

The objective of this experiment was to study and compare the effects of dietary supplementation of organic and inorganic zinc (Zn) on growth performance, nutrient utilisation and gene expression pattern of glucose transporter protein in peripheral blood mononuclear cells (PBMC) in Malabari kids. Fifteen, 3-4-month-old goat kids were divided into three groups uniformly by using completely randomised design (CRD). Group G1 was fed on basal diet as per NRC requirement, and G2 and G3 were fed on basal diet + 40 ppm Zn as inorganic zinc sulphate (ZnSO4) and 40 ppm Zn as organic Zn methionine, respectively, for a period of 91 days. Supplementation of inorganic and organic Zn had no significant effect on dry matter (DM) intake. The digestibility of crude protein (CP), ether extract (EE), neutral detergent fibre (NDF), hemicellulose and cellulose was significantly more in the organic Zn-supplemented group. The average daily gain and feed:gain ratio were significantly (p < 0.05) better in group G3 in comparison to G1 and G2, while the nitrogen retention was found to be (p < 0.01) higher in group G3 than in group G1. Zinc balance was found to be significantly (p < 0.01) increased in both supplemented groups with respect to unsupplemented group G1. The blood glucose level was (p < 0.01) lower in group G3 compared to group G1 suggesting the insulin-like activity of Zn. Serum Zn concentration was significantly (p < 0.01) increased in both Zn-supplemented groups. There was a significant (p < 0.05) rise in glucose transporter GLUT1 expression in groups G2 and G3 when compared to control group G1. Moreover, GLUT1 expression was found to be higher (p < 0.05) in group G3 as against the animals of group G2. Lowered blood glucose level might have stimulated more glucose transporter GLUT1 expression in PBMC. Organic Zn supplemented at 40 ppm level resulted in better growth performance, nutrient digestibility and nitrogen as well as Zn retention in goat kids. There was better absorption, and hence, less amount of Zn got excreted in the organic Zn-supplemented group.

Predictors of retained hemothorax in trauma: Results of an Eastern Association for the Surgery of Trauma multi-institutional trial.

BACKGROUND: The natural history of traumatic hemothorax (HTX) remains unclear. We aimed to describe outcomes of HTX following tube thoracostomy drainage and to delineate factors that predict progression to a retained hemothorax (RH). We hypothesized that initial large-volume HTX predicts the development of an RH. METHODS: We conducted a prospective, observational, multi-institutional study of adult trauma patients diagnosed with an HTX identified on computed tomography (CT) scan with volumes calculated at time of diagnosis. All patients were managed with tube thoracostomy drainage within 24 hours of presentation. Retained hemothorax was defined as blood-density fluid identified on follow-up CT scan or need for additional intervention after initial tube thoracostomy placement for HTX. RESULTS: A total of 369 patients who presented with an HTX initially managed with tube thoracostomy drainage were enrolled from 17 trauma centers. Retained hemothorax was identified in 106 patients (28.7%). Patients with RH had a larger median (interquartile range) HTX volume on initial CT compared with no RH (191 [48-431] mL vs. 88 [35-245] mL, p = 0.013) and were more likely to be older with a higher burden of thoracic injury. After controlling for significant differences between groups, RH was independently associated with a larger HTX on presentation, with a 15% increase in risk of RH for each additional 100 mL of HTX on initial CT imaging (odds ratio, 1.15; 95% confidence interval, 1.08-1.21; p < 0.001). Patients with an RH also had higher rates of pneumonia and longer hospital length of stay than those with successful initial management. Retained hemothorax was also associated with worse functional outcomes at discharge and first outpatient follow-up. CONCLUSION: Larger initial HTX volumes are independently associated with RH, and unsuccessful initial management with tube thoracostomy is associated with worse patient outcomes. Future studies should use this experience to assess a range of options for reducing the risk of unsuccessful initial management. LEVEL OF EVIDENCE: Therapeutic/care management study, level III.

Anatomical and functional outcomes following switching from aflibercept to ranibizumab in neovascular age-related macular degeneration in Europe: SAFARI study.

BACKGROUND/AIMS: Prospective data on switching anti-vascular endothelial growth factors in patients with neovascular age-related macular degeneration (nAMD) who have previously shown no/partial response are limited. This prospective study assessed the effect of switching from aflibercept to ranibizumab on anatomical and functional outcomes in patients with persistent/recurrent disease activity. METHODS: SAFARI (NCT02161575) was a 6-month, prospective, single-arm study conducted in the UK and Germany. Patients, meeting strict eligibility criteria for one of two subgroups (primary treatment failure or suboptimal treatment response), received 3 monthly intravitreal ranibizumab injections (0.5 mg). Thereafter, ranibizumab was administered pro re nata at monthly visits. The primary endpoint was change from baseline (CfB) to day 90 in central subfield retinal thickness (CSRT). Best-corrected visual acuity (BCVA) and retinal morphology parameters were assessed. RESULTS: One hundred patients were enrolled (primary treatment failure, 1; suboptimal treatment response, 99). In the overall population, there was a significant CfB in median CSRT of -30.75 µm (95% CI -59.50,-20.50; p<0.0001) to day 90. Improvements were also observed in other quantitative and qualitative optical coherence tomography parameters. In Early Treatment Diabetic Retinopathy Study letters assessed by category, 55% and 59% of patients gained 0-≥15 letters versus baseline at day 90 and day 180, respectively. However, mean improvements in BCVA (CfB) to each time point were small (≤2 letters). No new safety signals were identified. CONCLUSION: Switching from aflibercept to ranibizumab led to a significant improvement in CSRT, with ~60% experiencing stabilised/improved BCVA. Therefore, patients with nAMD who have shown a suboptimal response to aflibercept may benefit from switching to ranibizumab.

Rapid, Refined, and Robust Method for Expression, Purification, and Characterization of Recombinant Human Amyloid beta 1-42.

Amyloid plaques found in the brains of Alzheimer's disease patients primarily consists of amyloid beta 1-42 (Aß42). Commercially, Aß42 is synthesized using high-throughput peptide synthesizers resulting in the presence of impurities and the racemization of amino acids that affects its aggregation properties. Furthermore, the repeated purchase of even a small quantity (~1 mg) of commercial Aß42 can be expensive for academic researchers. Here, we describe a detailed methodology for robust expression of recombinant human Aß(M1-42) in Rosetta(DE3)pLysS and BL21(DE3)pLysS competent E. coli using standard molecular biology techniques with refined and rapid one-step analytical purification techniques. The peptide is isolated and purified from transformed cells using an optimized reverse-phase high-performance liquid chromatography (HPLC) protocol with commonly available C18 columns, yielding high amounts of peptide (~15-20 mg per 1 L culture) within a short period of time. The recombinant human Aß(M1-42) forms characteristic aggregates similar to synthetic Aß42 aggregates as verified by western blotting and atomic force microscopy to warrant future biological use. Our rapid, refined, and robust technique produces pure recombinant human Aß(M1-42) that may be used to synthesize chemical probes and in several downstream in vitro and in vivo assays to facilitate Alzheimer's disease research.

Occupational exposure during emergency department thoracotomy: A prospective, multi-institution study.

BACKGROUND: Occupational exposure is an important consideration during emergency department thoracotomy (EDT). While human immunodeficiency virus/hepatitis prevalence in trauma patients (0-16.8%) and occupational exposure rates during operative trauma procedures (1.9-18.0%) have been reported, exposure risk during EDT is unknown. We hypothesized that occupational exposure risk during EDT would be greater than other operative trauma procedures. METHODS: A prospective, observational study at 16 US trauma centers was performed (2015-2016). All bedside EDT resuscitation providers were surveyed with a standardized data collection tool and risk factors analyzed with respect to the primary end point, EDT occupational exposure (percutaneous injury, mucous membrane, open wound, or eye splash). Provider and patient variables and outcomes were evaluated with single and multivariable logistic regression analyses. RESULTS: One thousand three hundred sixty participants (23% attending, 59% trainee, 11% nurse, 7% other) were surveyed after 305 EDTs (gunshot wound, 68%; prehospital cardiopulmonary resuscitation, 57%; emergency department signs of life, 37%), of which 15 patients survived (13 neurologically intact) their hospitalization. Overall, 22 occupational exposures were documented, resulting in an exposure rate of 7.2% (95% confidence interval [CI], 4.7-10.5%) per EDT and 1.6% (95% CI, 1.0-2.4%) per participant. No differences in trauma center level, number of participants, or hours worked were identified. Providers with exposures were primarily trainees (68%) with percutaneous injuries (86%) during the thoracotomy (73%). Full precautions were utilized in only 46% of exposed providers, while multiple variable logistic regression determined that each personal protective equipment item utilized during EDT correlated with a 34% decreased risk of occupational exposure (odds ratio, 0.66; 95% CI, 0.48-0.91; p = 0.010). CONCLUSIONS: Our results suggest that the risk of occupational exposure should not deter providers from performing EDT. Despite the small risk of viral transmission, our data revealed practices that may place health care providers at unnecessary risk of occupational exposure. Regardless of the lifesaving nature of the procedure, improved universal precaution compliance with personal protective equipment is paramount and would further minimize occupational exposure risks during EDT. LEVEL OF EVIDENCE: Therapeutic/care management study, level III.

Management of Destructive Colon Injuries after Damage Control Surgery.

After the World War II, fecal diversion became the standard of care for colon injuries, although medical, logistic, and technical advancements have challenged this approach. Damage control surgery serves to temporize immediately life-threatening conditions, and definitive management of destructive colon injuries is delayed until after appropriate resuscitation. The bowel can be left in discontinuity for up to 3 days before edema ensues, but the optimal repair window remains within 12 to 48 hours. Delayed anastomosis performed at the take-back operation or stoma formation has been reported with variable results. Studies have revealed good outcomes in those undergoing anastomosis after damage control surgery; however, they point to a subgroup of trauma patients considered to be "high risk" that may benefit from fecal diversion. Risk factors influencing morbidity and mortality rates include hypotension, massive transfusion, the degree of intra-abdominal contamination, associated organ injuries, shock, left-sided colon injury, and multiple comorbid conditions. Patients who are not suitable for anastomosis by 36 hours after damage control may be best managed with a diverting stoma. Failures are more likely related to ongoing instability, and the management strategy of colorectal injury should be based mainly on the patient's overall condition.