GM-CSF receptor expression determines opposing innate memory phenotypes at different stages of myelopoiesis.

Inflammatory responses must be tightly coordinated with the activation of emergency myelopoiesis to produce potent myeloid cells that fight infection without causing excessive host damage. Here, we show that GM-CSF programs myeloid committed progenitors to produce trained macrophages (increased cytokine response), but programs the upstream non-committed LKS+ progenitors to produce tolerized macrophages (decreased cytokine response). In myeloid progenitors, GM-CSF strongly activates STAT5, ERK and Akt-mTOR signaling pathways, which are essential to establish a training program, whereas in LKS+ progenitors GM-CSF induces NF-κB translocation to the nucleus to establish a tolerization program. These differences arise from higher GM-CSF receptor expression in myeloid progenitors compared to LKS+ cells. We demonstrate that ß-catenin regulation of NF-κB nuclear translocation is central in this process. Glycogen synthase kinase 3 (GSK3) inactivation by strong ERK and PI3K-Akt signaling increases cytoplasmic ß-catenin levels to block NF-κB nuclear translocation in myeloid progenitors. In contrast, when ERK and PI3K-Akt signaling are weak, active GSK3 causes a decrease in ß-catenin, allowing NF-κB nuclear translocation in LKS+ progenitors. Finally, GM-CSF-induced LKS+ tolerization takes place in several murine models of trained immunity and in human CD34+ CD38- progenitors. Our study reveals that in addition to activating myelopoiesis, GM-CSF also programs early and immediate myeloid progenitors to produce opposing immune memory phenotypes. We propose that the inflammatory response from immediate myeloid progenitors may be balanced by the tolerized phenotype of early progenitors, thus providing a mechanism for appropriate resolution of inflammation and protection against a prolonged cytokine storm.

Direct TLR2 Signaling Through mTOR and TBK1 Induces C/EBPß and IRF7-Dependent Macrophage Differentiation in Hematopoietic Stem and Progenitor Cells.

During an infection, hematopoiesis is altered to increase the output of mature myeloid cells to fight off the pathogen. Despite convincing evidence that hematopoietic stem and progenitor cells (HSPCs) can sense pathogens directly, more mechanistic studies are needed to reveal whether pattern recognition receptor (PRR) signaling initiates myeloid development directly, or indirectly through the production of cytokines by HSPCs that can act in an autocrine/paracrine manner, or by a combination of both direct and indirect mechanisms. In this study, we have used an in vitro model of murine HSPCs to study myeloid differentiation in response to the TLR2 ligand Pam3CSK4 and showed that, besides indirect mechanisms, TLR2 stimulation of HSPCs promotes myelopoiesis directly by initiating a MyD88-dependent signaling. This direct differentiation program involves a combined activation of the transcription factors PU.1, C/EBPß, and IRF7 driven by TBK1 and PI3K/mTOR. Notably, downstream of MyD88, the activated TBK1 kinase can activate mTOR directly and IRF7 induction is mediated by both TBK1 and mTOR. TLR2 signaling also induces NF-κB dependent IL-6 production that may further induce indirect myeloid differentiation. Our results have identified the direct signaling pathways and the transcription factors involved in macrophage development from HSPCs in response to TLR2 engagement, a critical process to trigger a rapid immune response during infection.

Genome-wide CRISPR screen reveals CLPTM1L as a lipid scramblase required for efficient glycosylphosphatidylinositol biosynthesis.

SignificanceScramblases translocate lipids across the lipid bilayer without consumption of ATP, thereby regulating lipid distributions in cellular membranes. Cytosol-to-lumen translocation across the endoplasmic reticulum (ER) membrane is a common process among lipid glycoconjugates involved in posttranslational protein modifications in eukaryotes. These translocations are thought to be mediated by specific ER-resident scramblases, but the identity of these proteins and the underlying molecular mechanisms have been elusive. Here, we show that CLPTM1L, an integral membrane protein with eight putative transmembrane domains, is the major lipid scramblase involved in efficient glycosylphosphatidylinositol biosynthesis in the ER membrane. Our results validate the long-standing hypothesis that lipid scramblases ensure the efficient translocations of lipid glycoconjugates across the ER membrane for protein glycosylation pathways.

Rescue of Glycosylphosphatidylinositol-Anchored Protein Biosynthesis Using Synthetic Glycosylphosphatidylinositol Oligosaccharides.

The attachment of proteins to the cell membrane using a glycosylphosphatidylinositol (GPI) anchor is a ubiquitous process in eukaryotic cells. Deficiencies in the biosynthesis of GPIs and the concomitant production of GPI-anchored proteins lead to a series of rare and complicated disorders associated with inherited GPI deficiencies (IGDs) in humans. Currently, there is no treatment for patients suffering from IGDs. Here, we report the design, synthesis, and use of GPI fragments to rescue the biosynthesis of GPI-anchored proteins (GPI-APs) caused by mutation in genes involved in the assembly of GPI-glycolipids in cells. We demonstrated that the synthetic fragments GlcNAc-PI (1), Man-GlcN-PI (5), and GlcN-PI with two (3) and three lipid chains (4) rescue the deletion of the GPI biosynthesis in cells devoid of the PIGA, PIGL, and PIGW genes in vitro. The compounds allowed for concentration-dependent recovery of GPI biosynthesis and were highly active on the cytoplasmic face of the endoplasmic reticulum membrane. These synthetic molecules are leads for the development of treatments for IGDs and tools to study GPI-AP biosynthesis.

GM-CSF Programs Hematopoietic Stem and Progenitor Cells During Candida albicans Vaccination for Protection Against Reinfection.

More mechanistic studies are needed to reveal the hidden details of in vivo-induced trained immunity. Here, using a Candida albicans live vaccine mouse model we show that vaccination protects mice against a secondary infection and increases the number of bone marrow, and especially, splenic trained monocytes. Moreover, vaccination expands and reprograms hematopoietic stem and progenitor cells (HSPCs) early during infection and mobilize them transiently to the spleen to produce trained macrophages. Trained HSPCs are not only primed for myeloid cell production but also reprogramed to produce a greater amount of proinflammatory cytokines in response to a second challenge. Additionally, their adoptive transfer is sufficient to protect mice against reinfection. Mechanistically, autocrine GM-CSF activation of HSPCs is responsible for the trained phenotype and essential for the vaccine-induced protection. Our findings reveal a fundamental role for HSPCs in the trained immune protective response, opening new avenues for disease prevention and treatment.

An Animal Model of Acute and Chronic Chagas Disease With the Reticulotropic Y Strain of Trypanosoma cruzi That Depicts the Multifunctionality and Dysfunctionality of T Cells.

Chagas disease (ChD), a complex and persistent parasitosis caused by Trypanosoma cruzi, represents a natural model of chronic infection, in which some people exhibit cardiac or digestive complications that can result in death 20-40 years after the initial infection. Nonetheless, due to unknown mechanisms, some T. cruzi-infected individuals remain asymptomatic throughout their lives. Actually, no vaccine is available to prevent ChD, and treatments for chronic ChD patients are controversial. Chronically T. cruzi-infected individuals exhibit a deterioration of T cell function, an exhaustion state characterized by poor cytokine production and increased inhibitory receptor co-expression, suggesting that these changes are potentially related to ChD progression. Moreover, an effective anti-parasitic treatment appears to reverse this state and improve the T cell response. Taking into account these findings, the functionality state of T cells might provide a potential correlate of protection to detect individuals who will or will not develop the severe forms of ChD. Consequently, we investigated the T cell response, analyzed by flow cytometry with two multicolor immunofluorescence panels, to assess cytokines/cytotoxic molecules and the expression of inhibitory receptors, in a murine model of acute (10 and 30 days) and chronic (100 and 260 days) ChD, characterized by parasite persistence for up to 260 days post-infection and moderate inflammation of the colon and liver of T. cruzi-infected mice. Acute ChD induced a high antigen-specific multifunctional T cell response by producing IFN-γ, TNF-α, IL-2, granzyme B, and perforin; and a high frequency of T cells co-expressed 2B4, CD160, CTLA-4, and PD-1. In contrast, chronically infected mice with moderate inflammatory infiltrate in liver tissue exhibited monofunctional antigen-specific cells, high cytotoxic activity (granzyme B and perforin), and elevated levels of inhibitory receptors (predominantly CTLA-4 and PD-1) co-expressed on T cells. Taken together, these data support our previous results showing that similar to humans, the T. cruzi persistence in mice promotes the dysfunctionality of T cells, and these changes might correlate with ChD progression. Thus, these results constitute a model that will facilitate an in-depth search for immune markers and correlates of protection, as well as long-term studies of new immunotherapy strategies for ChD.

Drug overdose and child maltreatment across the United States' rural-urban continuum.

This national study of US counties (n = 2963) investigated whether county-level drug overdose mortality is associated with maltreatment report rates, and whether the relationship between overdose mortality and maltreatment reports is moderated by a county's rural, non-metro or metro status. Data included county-level 2015 maltreatment reports from the National Child Abuse and Neglect Data System, modeled drug-overdose mortality from the Centers for Disease Control, United States Department of Agriculture Rural-Urban Continuum Codes, US Census demographic data and crime reports from the Federal Bureau of Investigation. All data were linked across counties. Zero-inflated negative binomial (ZINB) regression was used for county-level analysis. As hypothesized, results from the ZINB model showed a significant and positive relationship between drug overdose mortality and child maltreatment report rates (χ = 101.26, p < .0001). This relationship was moderated by position on the rural-urban continuum (χ=8.76, p = .01). For metro counties, there was a 1.9% increase in maltreatment report rate for each additional increment of overdose deaths (IRR=1.019, CI=[1.010, 1.028]). For non-metro counties, the rate of increase was 1.8% higher than for metro counties (IRR=1.018, CI=[1.006, 1.030]); for rural counties, the rate of increase was 1.2% higher than for metro counties (IRR=1.012, CI=[0.999, 1.026]). Additional research is needed to determine why the relationship between drug overdose mortality and maltreatment reports is stronger in non-metro and rural communities. One potential driver requiring additional inquiry is that access to mental and physical health care and substance use treatment may be more limited outside of metropolitan counties.

A systematic review of socioeconomic status measurement in 13 years of U.S. injury research.

OBJECTIVE: The purpose of this review was to assess the impact of socioeconomic status (SES) on injury and to evaluate how U.S. injury researchers have measured SES over the past 13years in observational research studies. DESIGN & METHODS: This systematic review included 119 US injury studies indexed in PubMed between January 1, 2002 and August 31, 2015 that used one or more individual and/or area-level measures of SES as independent variables. Study findings were compared to the results of a previous review published in 2002. RESULTS: Findings indicate SES remains an important predictor of injury. SES was inversely related to injury in 78 (66%) of the studies; inverse relationships were more consistently found in studies of fatal injury (77.4%) than in studies of non-fatal injury (58%). Approximately two-thirds of the studies (n=73, 61%) measured SES along a gradient and 59% used more than one measure of SES (n=70). Studies that used a gradient measure of SES and/or more than one measure of SES identified significant relationships more often. These findings were essentially equivalent to those of a similar 2002 review (Cubbin & Smith, 2002). CONCLUSIONS: There remains a need to improve measurement of SES in injury research. Public health training programs should include best practices for measurement of SES, which include: measuring SES along a gradient, selecting SES indicators based on the injury mechanism, using the smallest geographic region possible for area-level measures, using multiple indicators when possible, and using both individual and area-level measures as both contribute independently to injury risk. Area-level indicators of SES are not accurate estimates of individual-level SES. PRACTICAL APPLICATIONS: Injury researchers should measure SES along a gradient and incorporate individual and area-level SES measures that are appropriate to the injury outcome under study.

Neighborhood Social Cohesion as a Mediator of Neighborhood Conditions on Mothers' Engagement in Physical Activity: Results From the Geographic Research on Wellbeing Study.

OBJECTIVES: The purpose of this study was to determine if social cohesion mediates the effects of neighborhood and household-level socioeconomic status (SES), perceptions of neighborhood safety, and access to parks on mothers' engagement in physical activity (PA). METHOD: Secondary analyses were conducted on cross-sectional data from The Geographic Research on Wellbeing (GROW) study. GROW includes survey data from a diverse sample of 2,750 California mothers. Structural equation modeling was used to test a conceptual multilevel mediation model, proposing social cohesion as a mediator of known predictors of PA. RESULTS: Social cohesion fully mediated the pathway from perceived neighborhood safety to mothers' PA. Social cohesion also mediated the significant relationship between neighborhood SES and PA; however, this mediation finding was not practically significant when considered in the context of the full model. Household SES was significantly positively related to both social cohesion and PA. Park access contributed significantly to social cohesion but not directly to PA Social cohesion did not significantly mediate relationships between park access or household SES and PA. CONCLUSIONS: There is a need for public health interventions to improve engagement in PA among individuals and neighborhoods with lower levels of socioeconomic resources. Interventions that create social cohesion within neighborhoods may have positive effects on mothers' PA, particularly in neighborhoods perceived as unsafe.

Supporting Community Health Workers After a Disaster: Findings From a Mixed-Methods Pilot Evaluation Study of a Psychoeducational Intervention.

OBJECTIVE: Community health workers (CHWs) in disaster-affected areas are at risk for emotional distress, as they support others while they may be in the process of rebuilding their own lives. The Resilience and Coping for the Healthcare Community (RCHC) intervention was developed in response to the stress CHWs faced after Hurricane Sandy. The intervention uses psychoeducation to help participants identify common stress responses, recognize signs of job burnout, and utilize healthy coping strategies. METHODS: A mixed-methods pilot of the RCHC intervention was conducted in 2013 with a convenience sample of staff from 6 federally qualified health centers (n=69). Validated measures of stress, coping, compassion fatigue and satisfaction, burnout, stress, and social provisions and a measure of perceived knowledge were administered at baseline, after the workshop, and at a 3-week follow-up. Semi-structured interviews were conducted with 10 randomly selected participants and were analyzed by using content analysis. RESULTS: From baseline to the post-workshop assessment, perceived knowledge scores increased from 24.59 to 30.34, t(62)=5.16 (P<0.001), and acute stress scores decreased significantly from 10.53 to 6.78, t(64)=4.74 (P<0.001). Significant increases from baseline to the 3-week follow-up (n=45) were found for perceived knowledge (24.05 to 27.24; t(40)=5.37; P<0.001), and social provisions (27.34 to 28.39; t(44)=2.15; P<0.05). CONCLUSIONS: Our qualitative findings indicated that the respondents valued learning about common stress responses and incorporating coping as part of a daily routine. Team building and normalization of emotions were seen as ancillary benefits that would reduce stress levels in the workplace. In conclusion, the RCHC intervention shows promise and should be investigated further in experimental studies. (Disaster Med Public Health Preparedness. 2016;page 1 of 8).

Sleep behaviors of infants and young children: associated demographic and acculturation characteristics among Hispanic teen mothers.

Accidental suffocation and strangulation in bed is a leading cause of preventable infant death. Bed sharing, teen motherhood, and Hispanic ethnicity have been associated with infant sleep suffocation death. Fifty-five Hispanic teen mothers were surveyed regarding acculturation/demographic characteristics and their infants' sleep behaviors. Most participants had 2 foreign-born parents from Latin America. Participants with 2 US-born parents were less likely to bed share than their less-acculturated peers. Many participants reported not always placing their infant in a supine sleep position. There is a significant need to reach out to Hispanic teen mothers, particularly from newer immigrant families, with culturally and linguistically appropriate multigenerational clinical messaging on the risks of infant bed sharing and nonsupine sleep positioning.

Risky drinking among parents of pediatric trauma patients.

BACKGROUND: Unintentional injury is the leading cause of death for children in the United States. An association between parental alcohol use and the frequency and severity of childhood injuries has been found; however, research is limited. The purpose of this study was to (1) describe demographics, child safety behaviors, and parental risky behaviors for a pediatric trauma patient population and (2) assess the relationship between positive screen results for risky drinking in parents and demographic and child safety behaviors. METHODS: Data were collected from a sample of parents of a child younger than 15 years who was admitted to an urban children's hospital for treatment for an unintentional injury. Data were analyzed using descriptive statistics, bivariate analyses, and logistic regression. RESULTS: A total of 926 parents of 693 patients were included in this study. Of the families who completed the survey, 37.1% (n = 257) had at least one parent screening positive for risky alcohol use. When looking at patients who ride bicycles, a little more than half (55.1%) were reported as consistently using a helmet. Results showed that inconsistent helmet use was associated with a higher likelihood of at least one parent screening positive for risky drinking (odds ratio, 1.58; 95% confidence interval, 1.06-2.36; p ≤ 0.05). CONCLUSION: Helmet use is a known prevention method of head injuries resulting from bicycle crashes. However, improvements need to be made on how to disseminate this information to parents and how to locate and intervene with the parents who have children that are at an increased risk of injury and injury recidivism. Using screening and brief intervention programs may assist in locating and reducing the potential of recurring visits by at-risk patients such as those in this sample who had at least one parent screening positive for risky drinking. LEVEL OF EVIDENCE: Prognostic study, level III.

Perceptions of injury and prevention practices among pregnant and parenting teenagers.

Injury is a leading cause of death for young children, and the children of teenaged parents may be at increased risk. This qualitative study explored pregnant and parenting teenagers' child safety beliefs and practices related to 4 topics: preventing accidental suffocation via safe sleeping practices, motor vehicle collision safety, prevention of inflicted head trauma, and drowning prevention. Twenty-four focus groups were held with 93 pregnant and/or parenting teenagers. Participants reported variation in their sleeping arrangements, transportation methods, caregivers, and childcare settings. Confusion over safety information was common. Child safety practices were influenced by boyfriends/husbands, parents, grandparents, and teachers.

Screening, brief intervention, and referral for alcohol use in adolescents: a systematic review.

BACKGROUND AND OBJECTIVE: Alcohol use by adolescents is widespread and is connected to a number of negative health and social outcomes. Adolescents receiving emergent care for injuries are often linked with risky use of alcohol. The trauma system has widely adopted the use of screening, brief intervention, and referral to treatment (SBIRT) for preventing alcohol-related injury recidivism and other negative outcomes. The purpose of this article is to review the evidence around SBIRT with adolescent patients in acute care settings. METHODS: This article reviews 7 randomized controlled trials evaluating risky drinking interventions among adolescent patients in acute care settings. All studies took place in the emergency departments of level I trauma centers. RESULTS: Four of the 7 studies reviewed demonstrated a significant intervention effect; however, no one intervention reduced both alcohol consumption and alcohol-related consequences. Two of these 4 studies only included patients ages 18 and older. Subgroup analyses with adolescents engaged in risky alcohol-related behaviors, conducted in 2 of the studies, showed significant intervention effects. Five studies showed positive consumption and/or consequences for all study participants regardless of condition, suggesting that an emergent injury and/or the screening process may have a protective effect. CONCLUSIONS: Based on existing evidence, it is not clear whether SBIRT is an effective approach to risky alcohol use among adolescent patients in acute care. Additional research is needed around interventions and implementation.

Teaching safety at a summer camp: evaluation of a water safety curriculum in an urban community setting.

OBJECTIVES: The purpose of this project was to evaluate a water safety curriculum in a low-income, minority-focused, urban youth summer camp. The curriculum is available to Safe Kids Coalitions across the country; however, it has not previously been evaluated. METHODS: Participants were pre-K to third-grade students (n = 166). Children watched a video and received the curriculum in a classroom setting. Each child was given a pre-, post-, and 3-week retention exam to assess knowledge change. Mean test scores and number of safety rules participants could list were analyzed using paired Student's t tests. Parents were given a baseline survey at the beginning (n = 140) and end of the weeklong curriculum (n = 118). RESULTS: The participants were 50% male, 27.5% Hispanic, 68.7% African American, and 3.8% biracial. Children were divided into three groups: pre-K/kindergarten, first and second grade, and third grade. Children in each of the groups received higher knowledge scores at the posttest (p = .0097, p < .0001, and p < .0001, respectively), with little decline in scores at the 3-week retention exam. Similar results were seen for the ability to list safety rules, though the number fell slightly between the posttest and retention test. CONCLUSION: The study demonstrates that children possessed more knowledge of water safety after receiving this curriculum. This knowledge increase was maintained through the 3-week retention exam. Further evaluation of the curriculum's content and its impact on water safety beliefs, attitudes, and behaviors are needed, as well as evaluation of additional settings, risk areas, and the role of parental involvement.

Under the influence with a child in the car: implications for child safety and caregiver intervention.

BACKGROUND: Injury is the leading cause of death for those aged 1 year to 44 years in the United States, with motor vehicle collisions (MVCs) the leading cause of injury-related deaths. Little data exist on the relationship between caregiver alcohol and drug use at the time of MVC and child passenger outcomes. We examined the relationship between caregiver substance use in MVCs and a number of demographic, crash severity, and medical outcomes for caregivers and children. METHODS: We identified family groups treated in the emergency department of a regional Level II trauma center after an MVC in a 1-year period from July 1, 2005, to June 30, 2006. The distribution and means of characteristics for substance and nonsubstance users were compared using χ analysis and Student's t tests, respectively. RESULTS: One in 10 vehicles contained an intoxicated caregiver at the time of MVC. In 363 identified caregivers, intoxication was associated with being male (p < 0.001), lack of safety device use (p = 0.003), rollover (p = 0.008), and ejection (p = 0.016). In the 278 family groups, intoxicated caregivers were related to child ejection (p = 0.009), the need for child hospital admission (p < 0.001), and driver intoxication was related to child lack of restraint (p = 0.045). CONCLUSION: These findings suggest a substantial number of child MVC victims arrive at the emergency room after riding with an intoxicated caregiver. Findings support the need for prevention programs focusing on substance use and driving for male caregivers, and further investigation on the need for screening and intervention for caregivers' risky alcohol and drug use after a child's MVC.

Pediatric injuries in Central Texas.

In Texas, more children aged from 1 through 14 years die from injury-related causes than from the next 9 causes of death combined. Injuries to children hospitalized in Central Texas during 2003 and 2004 were caused predominantly by falls and motor vehicle collisions (MVCs) and resulted in a large number of fractures and open wounds. Fifty-six Central Texas children died in 2003 and 2004 after reaching the hospital, out of a total of 175 children killed in injury-related events during this period. Most injury-related deaths were due to a traumatic brain injury. Most of the children suffering injury in MVCs were not restrained at the time of the accident. Injury data are invaluable to injury prevention efforts. These data were gathered from the Public Use Data File maintained by the Injury and EMS/Trauma Registry Group at the Department of State Health Services; limitations of the data set are discussed, and implications for injury prevention are highlighted.

Screening for risky alcohol use among caregivers of pediatric trauma patients: a pilot study.

BACKGROUND: Injury is the leading cause of death for children and has been linked to caregiver drinking. Screening and brief intervention for risky drinking has been successful in adult trauma centers but has not been evaluated in caregivers of pediatric trauma patients. The purpose of this study was to investigate a pilot screening process for risky drinking caregivers, to determine rates of risky alcohol use, and to assess potential relationships between risky drinking and child safety behaviors. METHODS: Caregivers of pediatric trauma patients were screened by trained injury prevention educators. The screening assessed risky drinking, tobacco and illicit drug use, and child safety behaviors. Data were analyzed using descriptive analysis, frequency comparisons, and univariate logistic regression. RESULTS: Over 7 months, 295 caregivers were screened; 32.5% (n = 96) screened positive for risky alcohol use. For 173 injured children, one caregiver was screened, and for 61 children, two caregivers were screened. In the one-caregiver group, 29% (n = 50) screened positive for risky drinking. For the two-caregiver group, in 18% (n = 11) of the cases, both caregivers screened positive, whereas in 39% (n = 24) only one caregiver screened positive. Males were more likely to screen positive (p < 0.01). Relationships between reported child safety behaviors and risky drinking were of interest, but not statistically significant. CONCLUSIONS: The results of our study demonstrate that a substantial number of caregivers of pediatric trauma patients will self-report risky drinking behaviors, and therefore, an opportunity exists for these families to receive the benefits of screening and brief intervention programs in pediatric trauma care settings.

Screening for attention-deficit/hyperactivity disorder in a select sample of injured and uninjured pediatric patients.

PURPOSE: Injury is the leading cause of morbidity and mortality to children. The purpose of this study is to compare attention-deficit/hyperactivity disorder (ADHD) screening results in a select group of injured pediatric patients to noninjured patients. METHODS: Parents of patients 6 to 12 years of age were enrolled in the study. Patients were either admitted for specific injury mechanisms (n = 133) or appendicitis (n = 157). Demographic and medical data were collected, and an ADHD screening tool was administered. Logistic regression models were used to compare screening results between groups. RESULTS: The injured patient group was 3.25 times more likely to screen positive for ADHD (odds ratio, 3.25; 95% confidence interval, 1.57-6.72; P = .002) than the appendicitis group. Among the injured patients who screened positive for ADHD, only 34.0% reported currently receiving treatment. CONCLUSIONS: Our results suggest that pediatric patients with certain injury mechanisms may warrant screening and referral for ADHD. Appropriate identification and treatment of undiagnosed ADHD may reduce the burden of injury recidivism. Screening and referral for ADHD within a trauma service should be evaluated for effectiveness as an injury prevention initiative.

Perturbation of DNA repair gene expression due to interspecies hybridization.

The effect of interspecies hybridization on gene regulation was examined using real-time polymerase chain reaction (RT-PCR) to measure the expression of five base-excision repair genes in brain, eye, gill, liver, and tailfin tissues from Xiphophorus parental species and F(1) hybrids. Relative mRNA levels of uracil N-glycosylase (Ung), Apurinic/apyrimidinic endonuclease (Ape1), polymerase-beta (Polb), flap endonuclease (Fen1), and DNA ligase (Lig1) were measured in three parental Xiphophorus species (X. maculatus Jp 163 B, X. helleri Sarabia, and X. andersi andC) and in two interspecies F(1) hybrids, the Sp-helleri hybrid (X. maculatus Jp 163 BxX. helleri Sarabia) and the Sp-andersi hybrid (X. maculatus Jp 163 BxX. andersi) to identify genes that undergo changes in expression levels upon interspecies hybridization. Significant differences in gene expression were observed between parental animals and their respective F(1) hybrids in both interspecies crosses. Generally, marked increases in DNA repair gene mRNA levels were observed across all tissues in F(1) hybrid animals from the Sp-helleri cross compared to either X. maculatus or X. helleri parents. In contrast, the Sp-andersi F(1) hybrid animals generally exhibited decreased base-excision repair gene expression, although this trend was more specific to individual tissues than observed for Sp-helleri hybrids.