Nonfatal Injuries Sustained in Mass Shootings in the US, 2012-2019: Injury Diagnosis Matrix, Incident Context, and Public Health Considerations.

INTRODUCTION: The epidemic of gun violence in the United States (US) is exacerbated by frequent mass shootings. In 2021, there were 698 mass shootings in the US, resulting in 705 deaths and 2,830 injuries. This is a companion paper to a publication in JAMA Network Open, in which the nonfatal outcomes of victims of mass shootings have been only partially described. METHODS: We gathered clinical and logistic information from 31 hospitals in the US about 403 survivors of 13 mass shootings, each event involving greater than 10 injuries, from 2012-19. Local champions in emergency medicine and trauma surgery provided clinical data from electronic health records within 24 hours of a mass shooting. We organized descriptive statistics of individual-level diagnoses recorded in medical records using International Classification of Diseases codes, according to the Barell Injury Diagnosis Matrix (BIDM), a standardized tool that classifies 12 types of injuries within 36 body regions. RESULTS: Of the 403 patients who were evaluated at a hospital, 364 sustained physical injuries-252 by gunshot wound (GSW) and 112 by non-ballistic trauma-and 39 were uninjured. Fifty patients had 75 psychiatric diagnoses. Nearly 10% of victims came to the hospital for symptoms triggered by, but not directly related to, the shooting, or for exacerbations of underlying conditions. There were 362 gunshot wounds recorded in the Barell Matrix (1.44 per patient). The Emergency Severity Index (ESI) distribution was skewed toward higher acuity than typical for an emergency department (ED), with 15.1% ESI 1 and 17.6% ESI 2 patients. Semi-automatic firearms were used in 100% of these civilian public mass shootings, with 50 total weapons for 13 shootings (Route 91 Harvest Festival, Las Vegas. 24). Assailant motivations were reported to be associated with hate crimes in 23.1%. CONCLUSION: Survivors of mass shootings have substantial morbidity and characteristic injury distribution, but 37% of victims had no GSW. Law enforcement, emergency medical systems, and hospital and ED disaster planners can use this information for injury mitigation and public policy planning. The BIDM is useful to organize data regarding gun violence injuries. We call for additional research funding to prevent and mitigate interpersonal firearm injuries, and for the National Violent Death Reporting System to expand tracking of injuries, their sequelae, complications, and societal costs.

Injury Characteristics, Outcomes, and Health Care Services Use Associated With Nonfatal Injuries Sustained in Mass Shootings in the US, 2012-2019.

Importance: Civilian public mass shootings (CPMSs) in the US result in substantial injuries. However, the types and consequences of these injuries have not been systematically described. Objective: To describe the injury characteristics, outcomes, and health care burden associated with nonfatal injuries sustained during CPMSs and to better understand the consequences to patients, hospitals, and society at large. Design, Setting, and Participants: This retrospective case series of nonfatal injuries from 13 consecutive CPMSs (defined as ≥10 injured individuals) from 31 hospitals in the US from July 20, 2012, to August 31, 2019, used data from trauma logs and medical records to capture injuries, procedures, lengths of stay, functional impairment, disposition, and charges. A total of 403 individuals treated in hospitals within 24 hours of the CPMSs were included in the analysis. Data were analyzed from October 27 to December 5, 2021. Exposures: Nonfatal injuries sustained during CPMSs. Main Outcomes and Measures: Injuries and diagnoses, treating services, procedures, hospital care, and monetary charges. Results: Among the 403 individuals included in the study, the median age was 33.0 (IQR, 24.5-48.0 [range, 1 to >89]) years, and 209 (51.9%) were women. Among the 386 patients with race and ethnicity data available, 13 (3.4%) were Asian; 44 (11.4%), Black or African American; 59 (15.3), Hispanic/Latinx; and 270 (69.9%), White. Injuries included 252 gunshot wounds (62.5%) and 112 other injuries (27.8%), and 39 patients (9.7%) had no physical injuries. One hundred seventy-eight individuals (53.1%) arrived by ambulance. Of 494 body regions injured (mean [SD], 1.35 [0.68] per patient), most common included an extremity (282 [57.1%]), abdomen and/or pelvis (66 [13.4%]), head and/or neck (65 [13.2%]), and chest (50 [10.1%]). Overall, 147 individuals (36.5%) were admitted to a hospital, 95 (23.6%) underwent 1 surgical procedure, and 42 (10.4%) underwent multiple procedures (1.82 per patient). Among the 252 patients with gunshot wounds, the most common initial procedures were general and trauma surgery (41 [16.3%]) and orthopedic surgery (36 [14.3%]). In the emergency department, 148 of 364 injured individuals (40.7%) had 199 procedures (1.34 per patient). Median hospital length of stay was 4.0 (IQR, 2.0-7.5) days; for 50 patients in the intensive care unit, 3.0 (IQR, 2.0-8.0) days (13.7% of injuries and 34.0% of admissions). Among 364 injured patients, 160 (44.0%) had functional disability at discharge, with 19 (13.3%) sent to long-term care. The mean (SD) charges per patient were $64 976 ($160 083). Conclusions and Relevance: Civilian public mass shootings cause substantial morbidity. For every death, 5.8 individuals are injured. These results suggest that including nonfatal injuries in the overall burden of CPMSs may help inform public policy to prevent and mitigate the harm caused by such events.

Expression of junctional proteins in choroid plexus epithelial cell lines: a comparative study.

BACKGROUND: There is an increasing interest in using choroid plexus (CP) epithelial cell lines to study the properties of the blood-cerebrospinal fluid barrier (BCSFB). Currently, there are three major CP-derived cell lines available. Z310 and TR-CSFB3, two immortalized cell lines carrying the simian virus 40 large T-antigen gene, were derived from rat CP epithelium, whereas the CPC-2 cell line was derived from human CP carcinoma. Although these cell lines have previously been used in various functional studies, the expression of adherens junction (AJ) and tight junction (TJ) proteins in these epithelial cells has not been systematically studied. Accordingly, in the present study, we sought to characterize the expression of these junctional proteins in these three cell lines. METHODS: The cells were grown in six-well cell culture plates. Reverse-transcriptase polymerase chain reaction, Western blotting, and immunocytochemistry were used to characterize the expression of AJ and TJ proteins in the CP cell lines. RESULTS: Z310 and TR-CSFB3 cells expressed a TJ protein, occludin, and its cytosolic binding partner, zonula occludens 1, as well as an AJ protein, E-cadherin, and beta-catenin, a cytoplasmic protein that interacts with E-cadherin. However, the expression of occludin and E-cadherin in TR-CSFB3 cells at both the mRNA and protein level was weaker than that found in Z301 cells. The immunocytochemical analysis also demonstrated that the staining pattern for these junctional proteins in TR-CSFB3 cells was discontinuous and the staining intensity was weaker than that observed in Z310 cells. The message for claudin 1 and claudin 2 was expressed at low levels in TR-CSFB3 cells and these cells were weakly immunopositive for claudin 1. In comparison, the message for these TJ proteins could not be detected in Z310 cells. CPC-2 cells expressed occludin, which was localized to areas of cell-cell contact, but the staining pattern for this TJ protein was found to be variable and irregular. Although CPC-2 cells expressed mRNA for claudin 1, claudin 2, and claudin 11, only claudin 1 was expressed at the protein level and it was localized to the nuclei rather than to areas of cell-cell contact. An AJ protein, E-cadherin, was also found to be mislocalized in CPC-2 cells, even though its cytosolic binding partner, beta-catenin, was restricted to areas of cell-cell contact, as in normal CP. CONCLUSION: The three CP cell lines analyzed in this study vary considerably with regard to the expression of AJ and TJ proteins, which is likely reflected by different barrier properties of these in vitro models of BCSFB.