The Role of Interpersonal Conflict as a Determinant of Firearm-Related Homicide-Suicides at Different Ages.

Although firearm-related homicide-suicides and firearm-related suicides are tragic and catastrophic events, there is increasing evidence that the two events have different precipitants and that understanding these precipitants may help prevention efforts. We aimed to assess the role of interpersonal conflict (IPC) and recent crises in firearm-related homicide-suicides as compared with firearm-related suicides alone. We also assessed whether these differences were consistent across young and old perpetrators. Using an unmatched case-control study, we compared firearm-related homicide-suicides andsuicides alone from 2003 to 2011 in the National Violent Death Registry data to assess the risk associated with IPC and crisis. Survival analysis was performed to compare time-to-incident of homicide-suicide versus suicide only. We derived odds ratios (ORs) and 95% confidence intervals (95%CI) due to IPC and recent crisis from mixed logistic regression models. Stratified analysis by age on the effect of IPC and recent crisis, and type of incident was also performed. After adjusting for relevant covariates, homicide-suicides were more likely than suicide alone following IPC (OR = 20.6, 95%CI = [16.6, 25.7]) and recent crisis (OR = 14.5, 95%CI = [12.4, 16.9]). The risk of firearm homicide-suicide compared with suicide associated with IPC was twice greater among those >30 years compared with those ≤30 years ( p-interaction = .033), and no differential by age associated with recent crisis ( p-interaction = .64). IPC and recent crisis are risk factors for committing homicide-suicides compared with suicides alone, with the risk doubly greater among older than younger perpetrators.

Firearm legislation and firearm mortality in the USA: a cross-sectional, state-level study.

BACKGROUND: In an effort to reduce firearm mortality rates in the USA, US states have enacted a range of firearm laws to either strengthen or deregulate the existing main federal gun control law, the Brady Law. We set out to determine the independent association of different firearm laws with overall firearm mortality, homicide firearm mortality, and suicide firearm mortality across all US states. We also projected the potential reduction of firearm mortality if the three most strongly associated firearm laws were enacted at the federal level. METHODS: We constructed a cross-sectional, state-level dataset from Nov 1, 2014, to May 15, 2015, using counts of firearm-related deaths in each US state for the years 2008-10 (stratified by intent [homicide and suicide]) from the US Centers for Disease Control and Prevention's Web-based Injury Statistics Query and Reporting System, data about 25 firearm state laws implemented in 2009, and state-specific characteristics such as firearm ownership for 2013, firearm export rates, and non-firearm homicide rates for 2009, and unemployment rates for 2010. Our primary outcome measure was overall firearm-related mortality per 100,000 people in the USA in 2010. We used Poisson regression with robust variances to derive incidence rate ratios (IRRs) and 95% CIs. FINDINGS: 31,672 firearm-related deaths occurred in 2010 in the USA (10·1 per 100,000 people; mean state-specific count 631·5 [SD 629·1]). Of 25 firearm laws, nine were associated with reduced firearm mortality, nine were associated with increased firearm mortality, and seven had an inconclusive association. After adjustment for relevant covariates, the three state laws most strongly associated with reduced overall firearm mortality were universal background checks for firearm purchase (multivariable IRR 0·39 [95% CI 0·23-0·67]; p=0·001), ammunition background checks (0·18 [0·09-0·36]; p<0·0001), and identification requirement for firearms (0·16 [0·09-0·29]; p<0·0001). Projected federal-level implementation of universal background checks for firearm purchase could reduce national firearm mortality from 10·35 to 4·46 deaths per 100,000 people, background checks for ammunition purchase could reduce it to 1·99 per 100,000, and firearm identification to 1·81 per 100,000. INTERPRETATION: Very few of the existing state-specific firearm laws are associated with reduced firearm mortality, and this evidence underscores the importance of focusing on relevant and effective firearms legislation. Implementation of universal background checks for the purchase of firearms or ammunition, and firearm identification nationally could substantially reduce firearm mortality in the USA. FUNDING: None.

State-specific, racial and ethnic heterogeneity in trends of firearm-related fatality rates in the USA from 2000 to 2010.

OBJECTIVES: To document overall, racial, ethnic and intent-specific spatiotemporal trends of firearm-related fatality rates (FRF rates) in the USA. DESIGN: Cross-sectional study per year from 2000 to 2010. SETTING USA PARTICIPANTS: Aggregate count of all people in the USA from 2000 to 2010. OUTCOME MEASURES: Data from the Web-based Injury Statistics Query and Reporting System from 2000 to 2010 was used to determine annual FRF rates per 100,000 and by states, race, ethnicity and intent. RESULTS: The average national 11-year FRF rate was 10.21/100,000, from 3.02 in Hawaii to 18.62 in Louisiana: 60% of states had higher than national rates and 41 states showed no temporal change. The average national FRF rates among African-Americans and Caucasians were 18.51 and 9.05/100,000 and among Hispanics and non-Hispanics were 7.13 and 10.13/100,000; Hispanics had a decreasing change of -0.18, p trend<0.0001. In states with increasing trends (Florida and Massachusetts), Caucasians and non-Hispanics drove the rise; while in states with decreasing trends (California, North Carolina, Arizona, Nevada, New York, Illinois, Maryland), Hispanics and African-Americans drove the fall. The average national FRF rates due to homicides (4.1/100,000) and suicides (5.8/100,000) remained constant, but varied between states. CONCLUSIONS: Endemic national FRF rates mask a wide variation in time trends between states. FRF rates were twice as high in African-Americans than Caucasians but decreased among Hispanics. Efforts to identify state-specific best practices can contribute to changes in national FRF rates that remain high.

Isoform-specific regulation and localization of the coxsackie and adenovirus receptor in human airway epithelia.

Adenovirus is an important respiratory pathogen. Adenovirus fiber from most serotypes co-opts the Coxsackie-Adenovirus Receptor (CAR) to bind and enter cells. However, CAR is a cell adhesion molecule localized on the basolateral membrane of polarized epithelia. Separation from the lumen of the airways by tight junctions renders airway epithelia resistant to inhaled adenovirus infection. Although a role for CAR in viral spread and egress has been established, the mechanism of initial respiratory infection remains controversial. CAR exists in several protein isoforms including two transmembrane isoforms that differ only at the carboxy-terminus (CAR(Ex7) and CAR(Ex8)). We found low-level expression of the CAR(Ex8) isoform in well-differentiated human airway epithelia. Surprisingly, in contrast to CAR(Ex7), CAR(Ex8) localizes to the apical membrane of epithelia where it augments adenovirus infection. Interestingly, despite sharing a similar class of PDZ-binding domain with CAR(Ex7), CAR(Ex8) differentially interacts with PICK1, PSD-95, and MAGI-1b. MAGI-1b appears to stoichiometrically regulate the degradation of CAR(Ex8) providing a potential mechanism for the apical localization of CAR(Ex8) in airway epithelial. In summary, apical localization of CAR(Ex8) may be responsible for initiation of respiratory adenoviral infections and this localization appears to be regulated by interactions with PDZ-domain containing proteins.