Prevalence of Low-Acuity Pediatric Emergency Medical Services Transports to a Pediatric Emergency Department in an Urban Area

OBJECTIVES

Many patients transported by Emergency Medical Services (EMS) do not have emergent resource needs. Estimates for the proportion of pediatric EMS calls for low-acuity complaints, and thus potential candidates for alternative dispositions, vary widely and are often based on physician judgment. A more accurate reference standard should include patient assessments, interventions, and dispositions. The objective of this study was to describe the prevalence and characteristics of low-acuity pediatric EMS calls in an urban area.

METHODS

This is a prospective observational study of children transported by EMS to a tertiary care pediatric emergency department. Patient acuity was defined using a novel composite measure that included physiologic assessments, resources used, and disposition. Bivariable and multivariable logistic regression were conducted to assess for factors associated with low-acuity status.

RESULTS

A total of 996 patients were enrolled, of whom 32.9% (95% confidence interval, 30.0-36.0) were low acuity. Most of the sample was Black, non-Hispanic with a mean age of 7 years. When compared with adolescents, children younger than 1 year were more likely to be low acuity (adjusted odds ratio, 3.1 [1.9-5.1]). Patients in a motor vehicle crash were also more likely to be low acuity (adjusted odds ratio, 2.4 [1.2-4.6]). All other variables, including race, insurance status, chief complaint, and dispatch time, were not associated with low-acuity status.

CONCLUSIONS

One third of pediatric patients transported to the pediatric emergency department by EMS in this urban area are for low-acuity complaints. Further research is needed to determine low-acuity rates in other jurisdictions and whether EMS providers can accurately identify low-acuity patients to develop alternative EMS disposition programs for children.

Rehydration Rates and Outcomes in Overweight Children With Diabetic Ketoacidosis

BACKGROUND AND OBJECTIVES

The Pediatric Emergency Care Applied Research Network Fluid Therapies Under Investigation in Diabetic Ketoacidosis (DKA) (FLUID) Trial found that rapid fluid infusion does not increase the risk of cerebral injury. Concern persists, however, whether fluid rates should be adjusted for overweight or obese patients. We used the FLUID Trial database to evaluate associations between fluid infusion rate and outcomes in these patients.

METHODS

We compared children and youth who were overweight, obese, or normal weight, in regard to protocol adherence, mental status changes, time to DKA resolution, and electrolyte abnormalities. We investigated associations between outcomes and the amount of fluid received in these groups.

RESULTS

Obese children and youth were more likely to receive fluids at rates slower than dictated by protocol. Overweight and obese children and youth in the fast fluid arms, who received fluids per the study protocol based on their measured weight, had similar rates of mental status changes or clinically apparent cerebral injury as those with normal weights. Risk of hypophosphatemia was increased in those receiving larger initial bolus volumes and reduced in those receiving higher rehydration rates. No other metabolic outcomes were associated with rehydration.

CONCLUSIONS

Protocol adherence data in the FLUID Trial suggest that physicians are uncomfortable using weight-based fluid calculations for overweight or obese children. However, higher rates of fluid infusion were not associated with increased risk of mental status changes or cerebral injury, suggesting that physicians should not limit fluid resuscitation in obese children and youth with DKA.

Clinical and Laboratory Predictors of Dehydration Severity in Children With Diabetic Ketoacidosis

STUDY OBJECTIVE

Our primary objective was to characterize the degree of dehydration in children with diabetic ketoacidosis (DKA) and identify physical examination and biochemical factors associated with dehydration severity. Secondary objectives included describing relationships between dehydration severity and other clinical outcomes.

METHODS

In this cohort study, we analyzed data from 753 children with 811 episodes of DKA in the Pediatric Emergency Care Applied Research Network Fluid Therapies Under Investigation Study, a randomized clinical trial of fluid resuscitation protocols for children with DKA. We used multivariable regression analyses to identify physical examination and biochemical factors associated with dehydration severity, and we described associations between dehydration severity and DKA outcomes.

RESULTS

Mean dehydration was 5.7% (SD 3.6%). Mild (0 to <5%), moderate (5 to <10%), and severe (≥10%) dehydration were observed in 47% (N=379), 42% (N=343), and 11% (N=89) of episodes, respectively. In multivariable analyses, more severe dehydration was associated with new onset of diabetes, higher blood urea nitrogen, lower pH, higher anion gap, and diastolic hypertension. However, there was substantial overlap in these variables between dehydration groups. The mean length of hospital stay was longer for patients with moderate and severe dehydration, both in new onset and established diabetes.

CONCLUSION

Most children with DKA have mild-to-moderate dehydration. Although biochemical measures were more closely associated with the severity of dehydration than clinical assessments, neither were sufficiently predictive to inform rehydration practice.

Intranasal fentanyl and discharge from the emergency department among children with sickle cell disease and vaso-occlusive pain: A multicenter pediatric emergency medicine perspective

Children with sickle cell disease (SCD) commonly experience vaso-occlusive pain episodes (VOE) due to sickling of erythrocytes, which often requires care in the emergency department. Our objective was to assess the use and impact of intranasal fentanyl for the treatment of children with SCD-VOE on discharge from the emergency department in a multicenter study. We conducted a cross-sectional study at 20 academic pediatric emergency departments in the United States and Canada. We used logistic regression to test bivariable and multivariable associations between the outcome of discharge from the emergency department and candidate variables theoretically associated with discharge. The study included 400 patients; 215 (54%) were female. The median age was 14.6 (interquartile range 9.8, 17.6) years. Nineteen percent (n = 75) received intranasal fentanyl in the emergency department. Children who received intranasal fentanyl had nearly nine-fold greater adjusted odds of discharge from the emergency department compared to those who did not (adjusted odds ratio 8.99, 95% CI 2.81-30.56, p < .001). The rapid onset of action and ease of delivery without intravenous access offered by intranasal fentanyl make it a feasible initial parenteral analgesic in the treatment of children with SCD presenting with VOE in the acute-care setting. Further study is needed to determine potential causality of the association between intranasal fentanyl and discharge from the emergency department observed in this multicenter study.

Relationships among biochemical measures in children with diabetic ketoacidosis

OBJECTIVES

Investigating empirical relationships among laboratory measures in children with diabetic ketoacidosis (DKA) can provide insights into physiological alterations occurring during DKA. We determined whether alterations in laboratory measures during DKA conform to theoretical predictions.

METHODS

We used Pearson correlation statistics and linear regression to investigate correlations between blood glucose, electrolytes, pH and PCO₂ at emergency department presentation in 1,681 pediatric DKA episodes. Among children with repeat DKA episodes, we also assessed correlations between laboratory measures at the first vs. second episode.

RESULTS

pH and bicarbonate levels were strongly correlated (r=0.64), however, pH and PCO₂ were only loosely correlated (r=0.17). Glucose levels were correlated with indicators of dehydration and kidney function (blood urea nitrogen (BUN), r=0.44; creatinine, r=0.42; glucose-corrected sodium, r=0.32). Among children with repeat DKA episodes, PCO₂ levels tended to be similar at the first vs. second episode (r=0.34), although pH levels were only loosely correlated (r=0.19).

CONCLUSIONS

Elevated glucose levels at DKA presentation largely reflect alterations in glomerular filtration rate. pH and PCO₂ are weakly correlated suggesting that respiratory responses to acidosis vary among individuals and may be influenced by pulmonary and central nervous system effects of DKA.

Clinician and Caregiver Determinations of Acuity for Children Transported by Emergency Medical Services: A Prospective Observational Study

STUDY OBJECTIVE

Many Emergency Medical Services (EMS) agencies have developed alternative disposition processes for patients with nonemergency problems, but there is a lack of evidence demonstrating EMS clinicians can accurately determine acuity in pediatric patients. Our study objective was to determine EMS and other stakeholders' ability to identify low acuity pediatric EMS patients.

METHODS

We conducted a prospective, observational study of children transported to a pediatric emergency department (ED) by EMS. Acuity was defined using a composite measure that included data from the patient's vital signs and examination, resources used (laboratory results, radiographs, etc), and disposition. For each patient, an EMS clinician, patient caregiver, ED nurse, and ED provider completed a survey as soon as possible after the patient's arrival at the ED. The survey asked respondents 2 questions: to state their level of agreement that a patient was low acuity and could the patient have been managed by various alternative dispositions. For each respondent group, we calculated the sensitivity, specificity, and positive and negative predictive values for low acuity versus the composite measure.

RESULTS

From August 2020 through September 2021, we approached 1,015 caregivers, of whom 996 (99.8%) agreed to participate and completed the survey. Survey completion varied between 78.7% and 84.1% for EMS and ED nurses and providers. The mean patient age was 7 years, 62.6% were non-Hispanic Black, and 60% were enrolled in public insurance programs. Of the 996 patient encounters, 33% were determined to be low acuity by the composite measure. The positive predictive value for EMS clinicians when identifying low acuity children was 0.60 (95% confidence intervals [CI], 0.58 to 0.67). The positive predictive value for ED nurses and providers was 0.67 (95% CI, 0.61 to 0.72) and 0.68 (95% CI, 0.63 to 0.74) respectively. The negative predictive value for EMS clinicians when identifying not low acuity children was 0.62 (95% CI, 0.58 to 0.67). The negative predictive value for ED nurses and providers was 0.72 (95% CI, 0.68 to 0.76) and 0.73 (95% CI, 0.70 to 0.77) respectively. Caregivers had the lowest positive predictive value 0.34 (95% CI, 0.30 to 0.40) but the highest negative predictive value 0.82 (95% CI, 0.79 to 0.85). The EMS clinicians, ED nurses and providers were more likely than caregivers to think that a child with a low acuity complaint could have been safely managed by alternative disposition.

CONCLUSION

All 4 groups studied had a limited ability to identify which children transported by EMS would have no emergency resource needs, and support for alternative disposition was limited. For children to be included in alternative disposition processes, novel triage tools, training, and oversight will be required to prevent undertriage.

2022 Systematic Review of Evidence-Based Guidelines for Prehospital Care

INTRODUCTION

Multiple national organizations and federal agencies have promoted the development, implementation, and evaluation of evidence-based guidelines (EBGs) for prehospital care. Previous efforts have identified opportunities to improve the quality of prehospital guidelines and highlighted the value of high-quality EBGs to inform initial certification and continued competency activities for EMS personnel.

OBJECTIVES

We aimed to perform a systematic review of prehospital guidelines published from January 2018 to April 2021, evaluate guideline quality, and identify top-scoring guidelines to facilitate dissemination and educational activities for EMS personnel.

METHODS

We searched the literature in Ovid Medline and EMBASE from January 2018 to April 2021, excluding guidelines identified in a prior systematic review. Publications were retained if they were relevant to prehospital care, based on organized reviews of the literature, and focused on providing recommendations for clinical care or operations. Included guidelines were appraised to identify if they met the National Academy of Medicine (NAM) criteria for high-quality guidelines and scored across the six domains of the Appraisal of Guidelines for Research and Evaluation (AGREE) II tool.

RESULTS

We identified 75 guidelines addressing a variety of clinical and operational aspects of EMS medicine. About half (n = 39, 52%) addressed time/life-critical conditions and 33 (44%) contained recommendations relevant to non-clinical/operational topics. Fewer than half (n = 35, 47%) were based on systematic reviews of the literature. Nearly one-third (n = 24, 32%) met all NAM criteria for clinical practice guidelines. Only 27 (38%) guidelines scored an average of >75% across AGREE II domains, with content relevant to guideline implementation most commonly missing.

CONCLUSIONS

This interval systematic review of prehospital EBGs identified many new guidelines relevant to prehospital care; more than all guidelines reported in a prior systematic review. Our review reveals important gaps in the quality of guideline development and the content in their publications, evidenced by the low proportion of guidelines meeting NAM criteria and the scores across AGREE II domains. Efforts to increase guideline dissemination, implementation, and related education may be best focused around the highest quality guidelines identified in this review.

Recommendations for Improving the Quality of Prehospital Evidence-Based Guidelines

Evidence-based guidelines that provide recommendations for clinical care or operations are increasingly being published to inform the EMS community. The quality of evidence evaluation and methodological rigor undertaken to develop and publish these recommendations vary. This can negatively affect dissemination, education, and implementation efforts. Guideline developers and end users could be better informed by efforts across medical specialties to improve the quality of guidelines, including the use of specific criteria that have been identified within the highest quality guidelines. In this special contribution, we aim to describe the current state of published guidelines available to the EMS community informed by two recent systematic reviews of existing prehospital evidenced based guidelines (EBGs). We further aim to provide a description of key elements of EBGs, methods that can be used to assess their quality, and concrete recommendations for guideline developers to improve the quality of evidence evaluation, guideline development, and reporting. Finally, we outline six key recommendations for improving prehospital EBGs, informed by systematic reviews of prehospital guidelines performed by the Prehospital Guidelines Consortium.

Cognitive function following diabetic ketoacidosis in young children with type 1 diabetes

INTRODUCTION

Young children with type 1 diabetes (T1D) may be at particularly high risk of cognitive decline following diabetic ketoacidosis (DKA). However, studies of cognitive functioning in T1D typically examine school-age children. The goal of this study was to examine whether a single experience of DKA is associated with lower cognitive functioning in young children. We found that recently diagnosed 3- to 5-year-olds who experienced one DKA episode, regardless of its severity, exhibited lower IQ scores than those with no DKA exposure.

METHODS

We prospectively enrolled 46 3- to 5-year-old children, who presented with DKA at the onset of T1D, in a randomized multi-site clinical trial evaluating intravenous fluid protocols for DKA treatment. DKA was moderate/severe in 22 children and mild in 24 children. Neurocognitive function was assessed once 2-6 months after the DKA episode. A comparison group of 27 children with T1D, but no DKA exposure, was also assessed. Patient groups were matched for age and T1D duration at the time of neurocognitive testing.

RESULTS

Children who experienced DKA, regardless of its severity, exhibited significantly lower IQ scores than children who did not experience DKA, F(2, 70) = 6.26, p = .003, partial η²  = .15. This effect persisted after accounting for socioeconomic status and ethnicity.

CONCLUSIONS

A single DKA episode is associated with lower IQ scores soon after exposure to DKA in young children.

Genome wide association analysis of root hair traits in rice reveals novel genomic regions controlling epidermal cell differentiation

BACKGROUND

Genome wide association (GWA) studies demonstrate linkages between genetic variants and traits of interest. Here, we tested associations between single nucleotide polymorphisms (SNPs) in rice (Oryza sativa) and two root hair traits, root hair length (RHL) and root hair density (RHD). Root hairs are outgrowths of single cells on the root epidermis that aid in nutrient and water acquisition and have also served as a model system to study cell differentiation and tip growth. Using lines from the Rice Diversity Panel-1, we explored the diversity of root hair length and density across four subpopulations of rice (aus, indica, temperate japonica, and tropical japonica). GWA analysis was completed using the high-density rice array (HDRA) and the rice reference panel (RICE-RP) SNP sets.

RESULTS

We identified 18 genomic regions related to root hair traits, 14 of which related to RHD and four to RHL. No genomic regions were significantly associated with both traits. Two regions overlapped with previously identified quantitative trait loci (QTL) associated with root hair density in rice. We identified candidate genes in these regions and present those with previously published expression data relevant to root hair development. We re-phenotyped a subset of lines with extreme RHD phenotypes and found that the variation in RHD was due to differences in cell differentiation, not cell size, indicating genes in an associated genomic region may influence root hair cell fate. The candidate genes that we identified showed little overlap with previously characterized genes in rice and Arabidopsis.

CONCLUSIONS

Root hair length and density are quantitative traits with complex and independent genetic control in rice. The genomic regions described here could be used as the basis for QTL development and further analysis of the genetic control of root hair length and density. We present a list of candidate genes involved in root hair formation and growth in rice, many of which have not been previously identified as having a relation to root hair growth. Since little is known about root hair growth in grasses, these provide a guide for further research and crop improvement.

Pyuria in Children with Diabetic Ketoacidosis

Acute kidney injury occurs frequently during pediatric diabetic ketoacidosis (DKA). We reviewed urinalyses from 561 children with DKA; pyuria was detected in 19% overall and in 40% of children with more comprehensive urine testing (≥3 urinalyses) during DKA.

Clinical Characteristics of Children with Cerebral Injury preceding Treatment of Diabetic Ketoacidosis

Previous studies have identified more severe acidosis and higher blood urea nitrogen (BUN) as risk factors for cerebral injury during treatment of diabetic ketoacidosis (DKA) in children; however, cerebral injury also can occur before DKA treatment. We found that lower pH and higher BUN levels also were associated with cerebral injury at presentation.

Response of Southeast Asian rice root architecture and anatomy phenotypes to drought stress

Drought stress in Southeast Asia greatly affects rice production, and the rice root system plays a substantial role in avoiding drought stress. In this study, we examined the phenotypic and genetic correlations among root anatomical, morphological, and agronomic phenotypes over multiple field seasons. A set of >200 rice accessions from Southeast Asia (a subset of the 3000 Rice Genomes Project) was characterized with the aim to identify root morphological and anatomical phenotypes related to productivity under drought stress. Drought stress resulted in slight increases in the basal metaxylem and stele diameter of nodal roots. Although few direct correlations between root phenotypes and grain yield were identified, biomass was consistently positively correlated with crown root number and negatively correlated with stele diameter. The accessions with highest grain yield were characterized by higher crown root numbers and median metaxylem diameter and smaller stele diameter. Genome-wide association study (GWAS) revealed 162 and 210 significant SNPs associated with root phenotypes in the two seasons which resulted in identification of 59 candidate genes related to root development. The gene OsRSL3 was found in a QTL region for median metaxylem diameter. Four SNPs in OsRSL3 were found that caused amino acid changes and significantly associated with the root phenotype. Based on the haplotype analysis for median metaxylem diameter, the rice accessions studied were classified into five allele combinations in order to identify the most favorable haplotypes. The candidate genes and favorable haplotypes provide information useful for the genetic improvement of root phenotypes under drought stress.

Emergency Medical Services Clinicians' Perspectives on Pediatric Non-Transport

OBJECTIVES

Emergency medical services clinicians do not transport one-third of all children assessed, even without official pediatric non-transport protocols. Little is known about how EMS clinicians and caregivers decide not to transport a child. Our objectives were to describe how EMS clinicians currently decide whether or not to transport a child and identify barriers to and enablers of successfully implementing an EMS clinician-initiated pediatric non-transport protocol.

METHODS

We conducted six virtual focus groups with EMS clinicians from the mid-Atlantic. A PhD trained facilitator moderated all groups using a semi-structured moderator guide. Multiple investigators independently coded a deidentified sample transcript. One team member then completed axial coding of the remaining transcripts. Thematic saturation was achieved. Clusters of similar codes were grouped into themes by consensus.

RESULTS

We recruited 50 participants, of whom 70% were paramedics and 28% emergency medical technicians. There was agreement that caregivers often use 9-1-1 for low acuity complaints. Participants stated that non-transport usually occurs after shared decision-making between EMS clinicians and caregivers; EMS clinicians advise whether transport is necessary, but caregivers are responsible for making the final decision and signing refusal documentation. Subthemes for how non-transport decisions were made included the presence of agency protocols, caregiver preferences, absence of a guardian on the scene, EMS clinician variability, and distance to the nearest ED. Participants identified the following features that would enable successful implementation of an EMS clinician-initiated non-transport process: a user-friendly interface, clear protocol endpoints, the inclusion of vital sign parameters, resources to leave with caregivers, and optional direct medical oversight.

CONCLUSIONS

EMS clinicians in our study agreed that non-transport is currently a caregiver decision, but noted a collaborative process of shared decision-making where EMS clinicians advise caregivers whether transport is indicated. Further research is needed to understand the safety of this practice. This study suggests there may be a need for EMS-initiated alternative disposition/non-transport protocols.

Root angle in maize influences nitrogen capture and is regulated by calcineurin B-like protein (CBL)-interacting serine/threonine-protein kinase 15 (ZmCIPK15)

Crops with reduced nutrient and water requirements are urgently needed in global agriculture. Root growth angle plays an important role in nutrient and water acquisition. A maize diversity panel of 481 genotypes was screened for variation in root angle employing a high-throughput field phenotyping platform. Genome-wide association mapping identified several single nucleotide polymorphisms (SNPs) associated with root angle, including one located in the root expressed CBL-interacting serine/threonine-protein kinase 15 (ZmCIPK15) gene (LOC100285495). Reverse genetic studies validated the functional importance of ZmCIPK15, causing a approximately 10° change in root angle in specific nodal positions. A steeper root growth angle improved nitrogen capture in silico and in the field. OpenSimRoot simulations predicted at 40 days of growth that this change in angle would improve nitrogen uptake by 11% and plant biomass by 4% in low nitrogen conditions. In field studies under suboptimal N availability, the cipk15 mutant with steeper growth angles had 18% greater shoot biomass and 29% greater shoot nitrogen accumulation compared to the wild type after 70 days of growth. We propose that a steeper root growth angle modulated by ZmCIPK15 will facilitate efforts to develop new crop varieties with optimal root architecture for improved performance under edaphic stress.

Soil penetration by maize roots is negatively related to ethylene-induced thickening

Radial expansion is a classic response of roots to a mechanical impedance that has generally been assumed to aid penetration. We analysed the response of maize nodal roots to impedance to test the hypothesis that radial expansion is not related to the ability of roots to cross a compacted soil layer. Genotypes varied in their ability to cross the compacted layer, and those with a steeper approach to the compacted layer or less radial expansion in the compacted layer were more likely to cross the layer and achieve greater depth. Root radial expansion was due to cortical cell size expansion, while cortical cell file number remained constant. Genotypes and nodal root classes that exhibited radial expansion in the compacted soil layer generally also thickened in response to exogenous ethylene in hydroponic culture, that is, radial expansion in response to ethylene was correlated with the thickening response to impedance in soil. We propose that ethylene insensitive roots, that is, those that do not thicken and can overcome impedance, have a competitive advantage under mechanically impeded conditions as they can maintain their elongation rates. We suggest that prolonged exposure to ethylene could function as a stop signal for axial root growth.

Adolescent alcohol use predicts cannabis use over a three year follow-up period

Background: Alcohol and cannabis use frequently co-occur, which can result in problems from social and academic impairment to dependence (i.e., alcohol use disorder [AUD] and/or cannabis use disorder [CUD]). The Emergency Department (ED) is an excellent site to identify adolescents with alcohol misuse, conduct a brief intervention, and refer to treatment; however, given time constraints, alcohol use may be the only substance assessed due to its common role in unintentional injury. The current study, a secondary data analysis, assessed the relationship between adolescent alcohol and cannabis use by examining the National Institute of Alcohol Abuse and Alcoholism (NIAAA) two question screen's (2QS) ability to predict future CUD at one, two, and three years post-ED visit. Methods: At baseline, data was collected via tablet self-report surveys from medically and behaviorally stable adolescents 12-17 years old (n = 1,689) treated in 16 pediatric EDs for non-life-threatening injury, illness, or mental health condition. Follow-up surveys were completed via telephone or web-based survey. Logistic regression compared CUD diagnosis odds at one, two, or three-year follow-up between levels constituting a single-level change in baseline risk categorization on the NIAAA 2QS (nondrinker versus low-risk, low- versus moderate-risk, moderate- versus high-risk). Receiver operating characteristic curve methods examined the predictive ability of the baseline NIAAA 2QS cut points for CUD at one, two, or three-year follow-up. Results: Adolescents with low alcohol risk had significantly higher rates of CUD versus nondrinkers (OR range: 1.94-2.76, p < .0001). For low and moderate alcohol risk, there was no difference in CUD rates (OR range: 1.00-1.08). CUD rates were higher in adolescents with high alcohol risk versus moderate risk (OR range: 2.39-4.81, p < .05). Conclusions: Even low levels of baseline alcohol use are associated with risk for a later CUD. The NIAAA 2QS is an appropriate assessment measure to gauge risk for future cannabis use.

Many paths to one goal: Identifying integrated rice root phenotypes for diverse drought environments

Drought is a major source of yield loss in the production of rice (Oryza sativa L.), and cultivars that maintain yield under drought across environments and drought stress scenarios are urgently needed. Root phenotypes directly affect water interception and uptake, so plants with root systems optimized for water uptake under drought would likely exhibit reduced yield loss. Deeper nodal roots that have a low metabolic cost per length (i.e., cheaper roots) via smaller root diameter and/or more aerenchyma and that transport water efficiently through smaller diameter metaxylem vessels may be beneficial during drought. Subsets of the Rice Diversity Panel 1 and Azucena × IR64 recombinant inbred lines were grown in two greenhouse and two rainout shelter experiments under drought stress to assess their shoot, root anatomical, and root architectural phenotypes. Root traits and root trait plasticity in response to drought varied with genotype and environment. The best-performing groups in the rainout shelter experiments had less plasticity of living tissue area in nodal roots than the worst performing groups. Root traits under drought were partitioned into similar groups or clusters via the partitioning-around-medoids algorithm, and this revealed two favorable integrated root phenotypes common within and across environments. One favorable integrated phenotype exhibited many, deep nodal roots with larger root cross-sectional area and more aerenchyma, while the other favorable phenotype exhibited many, deep nodal roots with small root cross-sectional area and small metaxylem vessels. Deeper roots with high theoretical axial hydraulic conductance combined with reduced root metabolic cost contributed to greater shoot biomass under drought. These results reflect how some root anatomical and architectural phenes work in concert as integrated phenotypes to influence the performance of plant under drought stress. Multiple integrated root phenotypes are therefore recommended to be selected in breeding programs for improving rice yield across diverse environments and drought scenarios.

Identifying pediatric patients with multisystem inflammatory syndrome in children presenting to a pediatric emergency department

OBJECTIVE

To compare clinical and laboratory features of children with Multisystem Inflammatory Syndrome in Children (MIS-C) to those evaluated for MIS-C in the Emergency Department (ED).

METHODS

We conducted a retrospective review of the medical record of encounters with testing for inflammatory markers in an urban, tertiary care Pediatric ED from March 1, 2020 to July 31, 2020. We abstracted demographic information, laboratory values, selected medications and diagnoses. We reviewed the record for clinical presentation for the subset of patients admitted to the hospital for suspected MIS-C. We then used receiver operating curves and logistic regression to evaluate the utility of candidate laboratory values to predict MIS-C status.

RESULTS

We identified 32 patients with confirmed MIS-C and 15 admitted and evaluated for MIS-C but without confirmation of SARS CoV-2 infection. We compared these patients to 267 encounters with screening laboratories for MIS-C. Confirmed MIS-C patients had an older median age, higher median fever on presentation and were predominantly of Hispanic and non-Hispanic Black race/ethnicity. All children with MIS-C had a C-reactive protein (CRP) >4.5 mg/dL, were more likely to have Brain Natriuretic Peptide >400 pg/mL (OR 10.50, 95%CI 4.40-25.04), D-Dimer >3 μg/mL (7.51, [3.18-17.73]), and absolute lymphocyte count (ALC) <1.5 K/mcL (21.42, [7.19-63.76]). We found CRP >4.5 mg/dL and ALC <1.5 K/mcL to be 86% sensitive and 91% specific to identify MIS-C among patients screened in our population.

CONCLUSIONS

We identified that elevated CRP and lymphopenia was 86% sensitive and 91% specific for identification of children with MIS-C.

Serum Sodium Concentration and Mental Status in Children With Diabetic Ketoacidosis

OBJECTIVES

Diabetic ketoacidosis (DKA) is typically characterized by low or low-normal serum sodium concentrations, which rise as hyperglycemia resolves. In retrospective studies, researchers found associations between declines in sodium concentrations during DKA and cerebral injury. We prospectively investigated determinants of sodium concentration changes and associations with mental status alterations during DKA.

METHODS

Using data from the Pediatric Emergency Care Applied Research Network Fluid Therapies Under Investigation in Diabetic Ketoacidosis Trial, we compared children who had declines in glucose-corrected sodium concentrations with those who had rising or stable concentrations. Children were randomly assigned to 1 of 4 intravenous fluid protocols that differed in infusion rate and sodium content. Data from the first 4, 8, and 12 hours of treatment were analyzed for 1251, 1086, and 877 episodes, respectively.

RESULTS

In multivariable analyses, declines in glucose-corrected sodium concentrations were associated with higher sodium and chloride concentrations at presentation and with previously diagnosed diabetes. Treatment with 0.45% (vs 0.9%) sodium chloride fluids was also associated with declines in sodium concentration; however, higher rates of fluid infusion were associated with declines in sodium concentration only at 12 hours. Frequencies of abnormal Glasgow Coma Scale scores and clinical diagnoses of cerebral injury were similar in patients with and without declines in glucose-corrected sodium concentrations.

CONCLUSIONS

Changes in glucose-corrected sodium concentrations during DKA treatment are influenced by the balance of free-water loss versus sodium loss at presentation and the sodium content of intravenous fluids. Declines in glucose-corrected sodium concentrations are not associated with mental status changes during treatment.

Effects of Fluid Rehydration Strategy on Correction of Acidosis and Electrolyte Abnormalities in Children With Diabetic Ketoacidosis

OBJECTIVE

Fluid replacement to correct dehydration, acidosis, and electrolyte abnormalities is the cornerstone of treatment for diabetic ketoacidosis (DKA), but little is known about optimal fluid infusion rates and electrolyte content. The objective of this study was to evaluate whether different fluid protocols affect the rate of normalization of biochemical derangements during DKA treatment.

RESEARCH DESIGN AND METHODS

The current analysis involved moderate or severe DKA episodes (n = 714) in children age <18 years enrolled in the Fluid Therapies Under Investigation in DKA (FLUID) Trial. Children were assigned to one of four treatment groups using a 2 × 2 factorial design (0.90% or 0.45% saline and fast or slow rate of administration).

RESULTS

The rate of change of pH did not differ by treatment arm, but Pco₂ increased more rapidly in the fast versus slow fluid infusion arms during the initial 4 h of treatment. The anion gap also decreased more rapidly in the fast versus slow infusion arms during the initial 4 and 8 h. Glucose-corrected sodium levels remained stable in patients assigned to 0.90% saline but decreased in those assigned to 0.45% saline at 4 and 8 h. Potassium levels decreased, while chloride levels increased more rapidly with 0.90% versus 0.45% saline. Hyperchloremic acidosis occurred more frequently in patients in the fast arms (46.1%) versus the slow arms (35.2%).

CONCLUSIONS

In children treated for DKA, faster fluid administration rates led to a more rapid normalization of anion gap and Pco₂ than slower fluid infusion rates but were associated with an increased frequency of hyperchloremic acidosis.

A Novel Use of NEMSIS to Create a PECARN-Specific EMS Patient Registry

Background: Research networks need access to EMS data to conduct pilot studies and determine feasibility of prospective studies. Combining data across EMS agencies is complicated and costly. Leveraging the National EMS Information System (NEMSIS) to extract select agencies' data may be an efficient and cost-effective method of providing network-level data. Objective: Describe the process of creating a Pediatric Emergency Care Applied Research Network (PECARN) specific NEMSIS data set and determine if these data were nationally representative. Methods: We established data use agreements (DUAs) with EMS agencies participating in PECARN to allow for agency identification through NEMSIS. Using 2019 NEMSIS version 3.4.0 data for EMS events with patients 18 years old and younger, we compared PECARN NEMSIS data to national NEMSIS data. Analyzed variables were selected for their ability to characterize events. No statistical analyses were utilized due to the large sample, instead, differences of ±5% were deemed clinically meaningful. Results: DUAs were established for 19 EMS agencies, creating a PECARN data set with 305,188 EMS activations of which 17,478 (5.7%) were pediatric. Of the pediatric activations, 17,140 (98.1%) were initiated through 9-1-1 and 9,487 (55.4%) resulted in transport by the documenting agency. The national data included 36,288,405 EMS activations of which 2,152,849 (5.9%) were pediatric. Of the pediatric activations 1,704,141 (79.2%) were initiated through 9-1-1 and 1,055,504 (61.9%) were transported by the documenting agency. Age and gender distributions were similar between the two groups, but the PECARN-specific data under-represents Black and Latinx patients. Comparison of EMS provider primary impressions revealed that three of the five most common were similar with injury being the most prevalent for both data sets along with mental/behavioral health and seizure. Conclusion: We demonstrated that NEMSIS can be leveraged to create network specific data sets. PECARN's EMS data were similar to the national data, though racial/ethnic minorities and some primary impressions may be under-represented. Additionally, more EMS activations in PECARN study areas originated through 9-1-1 but fewer were transported by the documenting agency. This is likely related to the type of participating agencies, their ALS response level, and the diversity of the communities they serve.

Targeted mutation of transcription factor genes alters metaxylem vessel size and number in rice roots

Root metaxylem vessels are responsible for axial water transport and contribute to hydraulic architecture. Variation in metaxylem vessel size and number can impact drought tolerance in crop plants, including rice, a crop that is particularly sensitive to drought. Identifying and validating candidate genes for metaxylem development would aid breeding efforts for improved varieties for drought tolerance. We identified three transcription factor candidate genes that potentially regulate metaxylem vessel size and number in rice based on orthologous annotations, published expression data, and available root and drought-related QTL data. Single gene knockout mutants were generated for each candidate using CRISPR-Cas9 genome editing. Root metaxylem vessel area and number were analyzed in 6-week-old knockout mutants and wild-type plants under well-watered and drought conditions in the greenhouse. Compared with wild type, LONESOME HIGHWAY (OsLHW) mutants had fewer, smaller metaxylem vessels in shallow roots and more, larger vessels in deep roots in drought conditions, indicating that OsLHW may be a repressor of drought-induced metaxylem plasticity. The AUXIN RESPONSE FACTOR 15 mutants showed fewer but larger metaxylem vessel area in well-watered conditions, but phenotypes were inconsistent under drought treatment. ORYZA SATIVA HOMEBOX 6 (OSH6) mutants had fewer, smaller metaxylem vessels in well-watered conditions with greater effects on xylem number than size. OSH6 mutants had larger shoots and more, deeper roots than the wild type in well-watered conditions, but there were no differences in performance under drought between mutants and wild type. Though these candidate gene mutants did not exhibit large phenotypic effects, the identification and investigation of candidate genes related to metaxylem traits in rice deepen our understanding of metaxylem development and are needed to facilitate incorporation of favorable alleles into breeding populations to improve drought stress tolerance.

Access to Optimal Emergency Care for Children

Every year, millions of pediatric patients seek emergency care. Significant barriers limit access to optimal emergency services for large numbers of children. The American Academy of Pediatrics, American College of Emergency Physicians, and Emergency Nurses Association have a strong commitment to identifying these barriers, working to overcome them, and encouraging, through education and system changes, improved access to emergency care for all children.

Priorities for Prehospital Evidence-Based Guideline Development: A Modified Delphi Analysis

Objective: Few areas of prehospital care are supported by evidence-based guidelines (EBGs). We aimed to identify gaps in clinical and operational prehospital EBGs to prioritize future EBG development and research funding. Methods: Using modified Delphi methodology, we sought consensus among experts in prehospital care and EBG development. Five rounds of surveys were administered between October 2019 and February 2020. Round 1 asked participants to list the top three gaps in prehospital clinical guidelines and top three gaps in operational guidelines that should be prioritized for guideline development and research funding. Based on responses, 3 reviewers performed thematic analysis to develop a list of prehospital EBG gaps, with participant feedback in Round 2. In Round 3, participants rated each gap's importance using a 5-point Likert scale, and participants' responses were averaged. In Round 4, participants rank-ordered 10 gaps with the highest mean scores identified in Round 3. In Round 5, participants indicated their agreement with sets of the highest ranked gaps. Results: Of 23 invited participants, 14 completed all 5 rounds. In Rounds 1 and 2, participants submitted 65 clinical and 58 operational gaps, and thematic analysis identified 23 unique clinical gaps and 28 unique operational gaps. The final prioritized list of clinical EBG gaps was: 1) airway management in adult and pediatric patients, 2) care of the pediatric patient, and 3) management of prehospital behavioral health emergencies, with 79% of participants agreeing. The final prioritized list of operational EBG gaps was: 1) define and measure the impact of EMS care on patient outcomes, 2) practitioner wellness, and 3) practitioner safety in the out-of-hospital environment, with 86% of participants agreeing. Conclusions: This modified Delphi study identifies gaps in prehospital EBGs that, if prioritized for development and research funding, would be expected to have the greatest impact on prehospital clinical care and operations.

Nodal root diameter and node number in maize (Zea mays L.) interact to influence plant growth under nitrogen stress

Under nitrogen limitation, plants increase resource allocation to root growth relative to shoot growth. The utility of various root architectural and anatomical phenotypes for nitrogen acquisition are not well understood. Nodal root number and root cross-sectional area were evaluated in maize in field and greenhouse environments. Nodal root number and root cross-sectional area were inversely correlated under both high and low nitrogen conditions. Attenuated emergence of root nodes, as opposed to differences in the number of axial roots per node, was associated with substantially reduced root number. Greater root cross-sectional area was associated with a greater stele area and number of cortical cell files. Genotypes that produced few, thick nodal roots rather than many, thin nodal roots had deeper rooting and better shoot growth in low nitrogen environments. Fewer nodal roots offset the respiratory and nitrogen costs of thicker diameter roots, since total nodal root respiration and nitrogen content was similar for genotypes with many, thin and few, thick nodal roots. We propose that few, thick nodal roots may enable greater capture of deep soil nitrogen and improve plant performance under nitrogen stress. Synergistic interactions between an architectural and anatomical trait may be an important strategy for nitrogen acquisition. Understanding trait interactions among different root nodes has important implications in for improving crop nutrient uptake and stress tolerance.

Multiseriate cortical sclerenchyma enhance root penetration in compacted soils

Mechanical impedance limits soil exploration and resource capture by plant roots. We examine the role of root anatomy in regulating plant adaptation to mechanical impedance and identify a root anatomical phene in maize (Zea mays) and wheat (Triticum aestivum) associated with penetration of hard soil: Multiseriate cortical sclerenchyma (MCS). We characterize this trait and evaluate the utility of MCS for root penetration in compacted soils. Roots with MCS had a greater cell wall-to-lumen ratio and a distinct UV emission spectrum in outer cortical cells. Genome-wide association mapping revealed that MCS is heritable and genetically controlled. We identified a candidate gene associated with MCS. Across all root classes and nodal positions, maize genotypes with MCS had 13% greater root lignin concentration compared to genotypes without MCS. Genotypes without MCS formed MCS upon exogenous ethylene exposure. Genotypes with MCS had greater lignin concentration and bending strength at the root tip. In controlled environments, MCS in maize and wheat was associated improved root tensile strength and increased penetration ability in compacted soils. Maize genotypes with MCS had root systems with 22% greater depth and 49% greater shoot biomass in compacted soils in the field compared to lines without MCS. Of the lines we assessed, MCS was present in 30 to 50% of modern maize, wheat, and barley cultivars but was absent in teosinte and wild and landrace accessions of wheat and barley. MCS merits investigation as a trait for improving plant performance in maize, wheat, and other grasses under edaphic stress.

Plant roots sense soil compaction through restricted ethylene diffusion

Soil compaction represents a major challenge for modern agriculture. Compaction is intuitively thought to reduce root growth by limiting the ability of roots to penetrate harder soils. We report that root growth in compacted soil is instead actively suppressed by the volatile hormone ethylene. We found that mutant Arabidopsis and rice roots that were insensitive to ethylene penetrated compacted soil more effectively than did wild-type roots. Our results indicate that soil compaction lowers gas diffusion through a reduction in air-filled pores, thereby causing ethylene to accumulate in root tissues and trigger hormone responses that restrict growth. We propose that ethylene acts as an early warning signal for roots to avoid compacted soils, which would be relevant to research into the breeding of crops resilient to soil compaction.

Root metaxylem and architecture phenotypes integrate to regulate water use under drought stress

At the genus and species level, variation in root anatomy and architecture may interact to affect strategies of drought avoidance. To investigate this idea, root anatomy and architecture of the drought-sensitive common bean (Phaseolus vulgaris) and drought-adapted tepary bean (Phaseolus acutifolius) were analyzed in relation to water use under terminal drought. Intraspecific variation for metaxylem anatomy and axial conductance was found in the roots of both species. Genotypes with high-conductance root metaxylem phenotypes acquired and transpired more water per unit leaf area, shoot mass, and root mass than genotypes with low-conductance metaxylem phenotypes. Interspecific variation in root architecture and root depth was observed where P. acutifolius has a deeper distribution of root length than P. vulgaris. In the deeper-rooted P. acutifolius, genotypes with high root conductance were better able to exploit deep soil water than genotypes with low root axial conductance. Contrastingly, in the shallower-rooted P. vulgaris, genotypes with low root axial conductance had improved water status through conservation of soil moisture for sustained water capture later in the season. These results indicate that metaxylem morphology interacts with root system depth to determine a strategy of drought avoidance and illustrate synergism among architectural and anatomical phenotypes for root function.

Frequency and Risk Factors of Acute Kidney Injury During Diabetic Ketoacidosis in Children and Association With Neurocognitive Outcomes

IMPORTANCE

Acute kidney injury (AKI) occurs commonly during diabetic ketoacidosis (DKA) in children, but the underlying mechanisms and associations are unclear.

OBJECTIVE

To investigate risk factors for AKI and its association with neurocognitive outcomes in pediatric DKA.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study was a secondary analysis of data from the Pediatric Emergency Care Applied Research Network Fluid Therapies Under Investigation in DKA Study, a prospective, multicenter, randomized clinical trial comparing fluid protocols for pediatric DKA in 13 US hospitals. Included DKA episodes occurred among children age younger than 18 years with blood glucose 300 mg/dL or greater and venous pH less than 7.25 or serum bicarbonate level less than 15 mEq/L.

EXPOSURES

DKA requiring intravenous insulin therapy.

MAIN OUTCOMES AND MEASURES

AKI occurrence and stage were assessed using serum creatinine measurements using Kidney Disease: Improving Global Outcomes criteria. DKA episodes with and without AKI were compared using univariable and multivariable methods, exploring associated factors.

RESULTS

Among 1359 DKA episodes (mean [SD] patient age, 11.6 [4.1] years; 727 [53.5%] girls; 651 patients [47.9%] with new-onset diabetes), AKI occurred in 584 episodes (43%; 95% CI, 40%-46%). A total of 252 AKI events (43%; 95% CI, 39%-47%) were stage 2 or 3. Multivariable analyses identified older age (adjusted odds ratio [AOR] per 1 year, 1.05; 95% CI, 1.00-1.09; P = .03), higher initial serum urea nitrogen (AOR per 1 mg/dL increase, 1.14; 95% CI, 1.11-1.18; P < .001), higher heart rate (AOR for 1-SD increase in z-score, 1.20; 95% CI, 1.09-1.32; P < .001), higher glucose-corrected sodium (AOR per 1 mEq/L increase, 1.03; 95% CI, 1.00-1.06; P = .001) and glucose concentrations (AOR per 100 mg/dL increase, 1.19; 95% CI, 1.07-1.32; P = .001), and lower pH (AOR per 0.1 increase, 0.63; 95% CI, 0.51-0.78; P < .001) as variables associated with AKI. Children with AKI, compared with those without, had lower scores on tests of short-term memory during DKA (mean [SD] digit span recall: 6.8 [2.4] vs 7.6 [2.2]; P = .02) and lower mean (SD) IQ scores 3 to 6 months after recovery from DKA (100.0 [12.2] vs 103.5 [13.2]; P = .005). Differences persisted after adjusting for DKA severity and demographic factors, including socioeconomic status.

CONCLUSIONS AND RELEVANCE

These findings suggest that AKI may occur more frequently in children with greater acidosis and circulatory volume depletion during DKA and may be part of a pattern of multiple organ injury involving the kidneys and brain.

Cognitive Function Following Diabetic Ketoacidosis in Children With New-Onset or Previously Diagnosed Type 1 Diabetes

OBJECTIVE

This study assessed whether a single diabetic ketoacidosis (DKA) episode is associated with cognitive declines in children with newly diagnosed type 1 diabetes and whether the same is true in children who had previously been diagnosed after accounting for variations in glycemic control and other relevant factors.

RESEARCH DESIGN AND METHODS

We prospectively enrolled 758 children, 6-18 years old, who presented with DKA in a randomized multisite clinical trial evaluating intravenous fluid protocols for DKA treatment. DKA was moderate/severe in 430 children and mild in 328 children. A total of 392 children with DKA had new onset of type 1 diabetes, and the rest were previously diagnosed. Neurocognitive assessment occurred 2-6 months after the DKA episode. A comparison group of 376 children with type 1 diabetes, but no DKA exposure, was also enrolled.

RESULTS

Among all patients, moderate/severe DKA was associated with lower intelligence quotient (IQ) (β = -0.12, P < 0.001), item-color recall (β = -0.08, P = 0.010), and forward digit span (β = -0.06, P = 0.04). Among newly diagnosed patients, moderate/severe DKA was associated with lower item-color recall (β = -0.08, P = 0.04). Among previously diagnosed patients, repeated DKA exposure and higher HbA_1c were independently associated with lower IQ (β = -0.10 and β = -0.09, respectively, P < 0.01) and higher HbA_1c was associated with lower item-color recall (β = -0.10, P = 0.007) after hypoglycemia, diabetes duration, and socioeconomic status were accounted for.

CONCLUSIONS

A single DKA episode is associated with subtle memory declines soon after type 1 diabetes diagnosis. Sizable IQ declines are detectable in children with known diabetes, suggesting that DKA effects may be exacerbated in children with chronic exposure to hyperglycemia.

Multiple Integrated Root Phenotypes Are Associated with Improved Drought Tolerance

To test the hypothesis that multiple integrated root phenotypes would co-optimize drought tolerance, we phenotyped the root anatomy and architecture of 400 mature maize (Zea mays) genotypes under well-watered and water-stressed conditions in the field. We found substantial variation in all 23 root phenes measured. A phenotypic bulked segregant analysis revealed that bulks representing the best and worst performers in the field displayed distinct root phenotypes. In contrast to the worst bulk, the root phenotype of the best bulk under drought consisted of greater cortical aerenchyma formation, more numerous and narrower metaxylem vessels, and thicker nodal roots. Partition-against-medians clustering revealed several clusters of unique root phenotypes related to plant performance under water stress. Clusters associated with improved drought tolerance consisted of phene states that likely enable greater soil exploration by reallocating internal resources to greater root construction (increased aerenchyma content, larger cortical cells, fewer cortical cell files), restrict uptake of water to conserve soil moisture (reduced hydraulic conductance, narrow metaxylem vessels), and improve penetrability of hard, dry soils (thick roots with a larger proportion of stele, and smaller distal cortical cells). We propose that the most drought-tolerant-integrated phenotypes merit consideration as breeding ideotypes.

Genetic control of root architectural plasticity in maize

Root phenotypes regulate soil resource acquisition; however, their genetic control and phenotypic plasticity are poorly understood. We hypothesized that the responses of root architectural phenes to water deficit (stress plasticity) and different environments (environmental plasticity) are under genetic control and that these loci are distinct. Root architectural phenes were phenotyped in the field using a large maize association panel with and without water deficit stress for three seasons in Arizona and without water deficit stress for four seasons in South Africa. All root phenes were plastic and varied in their plastic response. We identified candidate genes associated with stress and environmental plasticity and candidate genes associated with phenes in well-watered conditions in South Africa and in well-watered and water-stress conditions in Arizona. Few candidate genes for plasticity overlapped with those for phenes expressed under each condition. Our results suggest that phenotypic plasticity is highly quantitative, and plasticity loci are distinct from loci that control phene expression in stress and non-stress, which poses a challenge for breeding programs. To make these loci more accessible to the wider research community, we developed a public online resource that will allow for further experimental validation towards understanding the genetic control underlying phenotypic plasticity.

Statewide Pediatric Facility Recognition Programs and Their Association with Pediatric Readiness in Emergency Departments in the United States

OBJECTIVE

To describe the relationship between statewide pediatric facility recognition (PFR) programs and pediatric readiness in emergency departments (EDs) in the US.

STUDY DESIGN

Data were extracted from the 2013 National Pediatric Readiness Project assessment (4083 EDs). Pediatric readiness was assessed using the weighted pediatric readiness score (WPRS) based on a 100-point scale. Descriptive statistics were used to compare WPRS between recognized and nonrecognized EDs and between states with or without a PFR program. A linear mixed model with WPRS was used to evaluate state PFR programs on pediatric readiness.

RESULTS

Eight states were identified with a PFR program. EDs in states with a PFR program had a higher WPRS compared with states without a PFR program (overall a 9.1-point higher median WPRS; P < .001); EDs recognized in a PFR program had a 21.7-point higher median WPRS compared with nonrecognized EDs (P < .001); and between states with a statewide PFR program, there was high variability of participation within the states. We found state-level PFR programs predicted a higher WPRS compared with states without a PFR program (β = 5.49; 95% CI 2.76-8.23).

CONCLUSIONS

Statewide PFR programs are based on national guidelines and identify those EDs that adhere to a standard level of readiness for children. These statewide PFR initiatives are associated with higher pediatric readiness. As scalable strategies are needed to improve emergency care for children, our study suggests that statewide PFR programs may be one way to improve pediatric readiness and underscores the need for further implementation and evaluation.

Genetic control of root anatomical plasticity in maize

Root anatomical phenes have important roles in soil resource capture and plant performance; however, their phenotypic plasticity and genetic architecture is poorly understood. We hypothesized that (a) the responses of root anatomical phenes to water deficit (stress plasticity) and different environmental conditions (environmental plasticity) are genetically controlled and (b) stress and environmental plasticity are associated with different genetic loci than those controlling the expression of phenes under water-stress and well-watered conditions. Root anatomy was phenotyped in a large maize (Zea mays L.) association panel in the field with and without water deficit stress in Arizona and without water deficit stress in South Africa. Anatomical phenes displayed stress and environmental plasticity; many phenotypic responses to water deficit were adaptive, and the magnitude of response varied by genotype. We identified 57 candidate genes associated with stress and environmental plasticity and 64 candidate genes associated with phenes under well-watered and water-stress conditions in Arizona and under well-watered conditions in South Africa. Four candidate genes co-localized between plasticity groups or for phenes expressed under each condition. The genetic architecture of phenotypic plasticity is highly quantitative, and many distinct genes control plasticity in response to water deficit and different environments, which poses a challenge for breeding programs.

Root cortical anatomy is associated with differential pathogenic and symbiotic fungal colonization in maize

Root anatomical phenotypes vary among maize (Zea mays) cultivars and may have adaptive value by modifying the metabolic cost of soil exploration. However, the microbial trade-offs of these phenotypes are unknown. We hypothesized that nodal roots of maize with contrasting cortical anatomy have different patterns of mutualistic and pathogenic fungal colonization. Arbuscular mycorrhizal colonization in the field and mesocosms, root rots in the field, and Fusarium verticillioides colonization in mesocosms were evaluated in maize genotypes with contrasting root cortical anatomy. Increased aerenchyma and decreased living cortical area were associated with decreased mycorrhizal colonization in mesocosm and field experiments with inbred genotypes. In contrast, mycorrhizal colonization of hybrids increased with larger aerenchyma lacunae; this increase coincided with larger root diameters of hybrid roots. F. verticillioides colonization was inversely correlated with living cortical area in mesocosm-grown inbreds, and no relation was found between root rots and living cortical area or aerenchyma in field-grown hybrids. Root rots were positively correlated with cortical cell file number and inversely correlated with cortical cell size. Mycorrhizae and root rots were inversely correlated in field-grown hybrids. We conclude that root anatomy is associated with differential effects on pathogens and mycorrhizal colonization of nodal roots in maize.

Genotypic variation and nitrogen stress effects on root anatomy in maize are node specific

Root phenotypes that improve nitrogen acquisition are avenues for crop improvement. Root anatomy affects resource capture, metabolic cost, hydraulic conductance, anchorage, and soil penetration. Cereal root phenotyping has centered on primary, seminal, and early nodal roots, yet critical nitrogen uptake occurs when the nodal root system is well developed. This study examined root anatomy across nodes in field-grown maize (Zea mays L.) hybrid and inbred lines under high and low nitrogen regimes. Genotypes with high nitrogen use efficiency (NUE) had larger root diameter and less cortical aerenchyma across nodes under stress than genotypes with lower NUE. Anatomical phenes displayed slightly hyperallometric relationships to shoot biomass. Anatomical plasticity varied across genotypes; most genotypes decreased root diameter under stress when averaged across nodes. Cortex, stele, total metaxylem vessel areas, and cortical cell file and metaxylem vessel numbers scaled strongly with root diameter across nodes. Within nodes, metaxylem vessel size and cortical cell size were correlated, and root anatomical phenotypes in the first and second nodes were not representative of subsequent nodes. Node, genotype, and nitrogen treatment affect root anatomy. Understanding nodal variation in root phenes will enable the development of plants that are adapted to low nitrogen conditions.

Propensity score analysis of non-anatomical versus anatomical resection of colorectal liver metastases

Background

There are concerns that non‐anatomical resection (NAR) worsens perioperative and oncological outcomes compared with those following anatomical resection (AR) for colorectal liver metastases (CRLM). Most previous studies have been biased by the effect of tumour size. The aim of this study was to compare oncological outcomes after NAR versus AR.

Methods

This was a retrospective study of consecutive patients who underwent CRLM resection with curative intent from 1999 to 2016. Data were retrieved from a prospectively developed database. Survival and perioperative outcomes for NAR and AR were compared using propensity score analyses.

Results

Some 358 patients were included in the study. Median follow‐up was 34 (i.q.r. 16–68) months. NAR was associated with significantly less morbidity compared with AR (31·1 versus 44·4 per cent respectively; P = 0·037). Larger (hazard ratio (HR) for lesions 5 cm or greater 1·81, 95 per cent c.i. 1·13 to 2·90; P = 0·035) or multiple (HR 1·48, 1·03 to 2·12; P = 0·035) metastases were associated with poor overall survival (OS). Synchronous (HR 1·33, 1·01 to 1·77; P = 0·045) and multiple (HR 1·51, 1·14 to 2·00; P = 0·004) liver metastases, major complications after liver resection (HR 1·49, 1·05 to 2·11; P = 0·026) or complications after resection of the primary colorectal tumour (HR 1·51, 1·01 to 2·26; P = 0·045) were associated with poor disease‐free survival (DFS). AR was prognostic for poor OS only in tumours smaller than 30 mm, and R1 margin status was not prognostic for either OS or DFS. NAR was associated with a higher rate of salvage resection than AR following intrahepatic recurrence.

Conclusions

NAR has at least equivalent oncological outcomes to AR while proving to be safer. NAR should therefore be the primary surgical approach to CRLM, especially for lesions smaller than 30 mm.

Are the Fitzpatrick Skin Phototypes Valid for Cancer Risk Assessment in a Racially and Ethnically Diverse Sample of Women?

The Fitzpatrick Skin Phototypes (FSP) were developed to classify skin color and response to ultraviolet radiation. FSP are used clinically to assess risk for sunburn and skin cancer. Our aim was to determine the criterion-related validity of self-reported FSP when compared with skin color and sunburn history, controlling for age, race/ethnicity, and seasonality/geography. We performed a secondary analysis of data (N=466) from an observational study. The racial/ethnic composition of the sample was 45% White/White Hispanic (WWH), 40% Black/Black Hispanic (BBH), and 15% Other Identities. Outcome measures were self-reported FSP and sunburn history, as well as physiological measures of skin color (L* lightness/darkness, a* redness/greenness, b* yellowness/blueness). Correlation between FSP and L* was -.77 (95% CI -.81, -.73; P<.001). Although 60% of the variance in FSP was accounted for by L* values for the entire sample, only 5% of the variance was accounted for among BBH participants (r=-.23), and up to 30% for WWH/Other Identity participants (r=-.48 and -.52). Multiple regression analysis indicated L* and b* values, sunburn history, and race/ethnicity, but not geography/seasonality or a* values significantly and collectively accounted for 72% of the variance in FSP. While the criterion validity of FSP was established by the strong relationship between L* values and FSP for the entire sample, when examined at the level of individual racial/ethnic subgroups, criterion validity of FSP was not demonstrated. When self-reported FSP are used for clinical skin assessment and sun cancer screening, they provide a restricted range of options for people with darker skin that does not capture variations in their skin color. Inaccuracy of clinical data may lead to unequal treatment or inadequate cancer risk assessment.

Predictive Validity of a 2-Question Alcohol Screen at 1-, 2-, and 3-Year Follow-up

BACKGROUND

The National Institute on Alcohol Abuse and Alcoholism (NIAAA) 2-question screen is a valid adolescent alcohol screening tool. No studies have examined if this tool predicts future alcohol problems. We conducted a study at 16 pediatric emergency departments to determine the tool's predictive validity for alcohol misuse and alcohol use disorders (AUDs).

METHODS

Participants (N = 4834) completed a baseline assessment battery. A subsample of participants completed the battery at 1, 2, and 3 years follow up.

RESULTS

Of the 2209 participants assigned to follow-up, 1611 (73%) completed a 1-year follow-up, 1591 (72%) completed a 2-year follow-up, and 1377 (62%) completed a 3-year follow-up. The differences in AUDs between baseline NIAAA screen nondrinkers and lower-risk drinkers were statistically significant at 1 year (P = .0002), 2 years (P <.0001), and 3 years (P = .0005), as were the differences between moderate- and highest-risk drinkers at 1 and 2 years (P < .0001 and P = .0088, respectively) but not at 3 years (P = .0758). The best combined score for sensitivity (86.2% at 1 year, 75.6% at 2 years, and 60.0% at 3 years) and specificity (78.1% at 1 year, 79.2% at 2 years, and 80.0% at 3 years) was achieved by using "lower risk" and higher as a cutoff for the prediction of a Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition diagnosis.

CONCLUSIONS

The NIAAA 2-question screen can accurately characterize adolescent risk for future AUDs. Future studies are needed to determine optimaluse of the screen.

Teacher Retention Issues: How Some Principals are Supporting and Keeping New Teachers

Beginning teachers continue to exit the classroom in alarming numbers, despite numerous recruitment and retention strategies. High teacher turnover rates result in a deficit of quality teachers and instruction; a loss of continuity and commitment; and time, attention, and funds devoted to recruitment versus support. The purpose of this empirical inquiry of teacher retention issues is to better understand the leadership styles of principals who lead schools that have low attrition and transfer rates. Through the use of semistructured interviews with 12 principals, as well as focus group interviews with 4 to 6 new teachers (i.e. teachers with 1 to 3 years of experience) at each of the 12 schools (n = 61), data were triangulated, and some common characteristics and successful strategies that principals use to support and retain teachers were identified and analyzed through the lens of professional learning communities. Findings indicate that the following principals are retaining teachers at a rate higher than that of their peers: principals with a keen awareness of issues affecting new teachers; principals with a proactive versus reactive approach in supporting new teachers; and principals with a commitment to professional growth and excellence for themselves their students, and their teachers (new and veteran alike).

Screening for Adolescent Alcohol Use in the Emergency Department: What Does It Tell Us About Cannabis, Tobacco, and Other Drug Use?

BACKGROUND

The pediatric emergency department (PED) represents an opportune time for alcohol and drug screening. The National Institute of Alcohol Abuse and Alcoholism (NIAAA) recommends a two-question alcohol screen for adolescents as a predictor of alcohol and drug misuse.

OBJECTIVE

A multi-site PED study was conducted to determine the association between the NIAAA two-question alcohol screen and adolescent cannabis use disorders (CUD), cigarette smoking, and lifetime use of other drugs.

METHODS

Participants included 12-17-year olds (n = 4834) treated in one of 16 participating PEDs. An assessment battery, including the NIAAA two-question screen and other measures of alcohol, tobacco and drug use, was self-administered on a tablet computer.

RESULTS

A diagnosis of CUD, lifetime tobacco use or lifetime drug use was predicted by any self-reported alcohol use in the past year, which indicates a classification of moderate risk for middle school ages and low risk for high school ages on the NIAAA two-question screen. Drinking was most strongly predictive of a CUD, somewhat weaker for lifetime tobacco use, and weakest for lifetime drug use. This same pattern held for high school and middle school students and was stronger for high school students over middle school students for all three categories. This association was also found across gender, ethnicity and race. The association was strongest for CUD for high school students, sensitivity 81.7% (95% CI, 77.0, 86.5) and specificity 70.4% (95% CI, 68.6, 72.1). Conclusions/Importance: A single question about past year alcohol use can provide valuable information about other substance use, particularly marijuana.

Progressive drought alters architectural and anatomical traits of rice roots

BACKGROUND

Root architectural and anatomical phenotypes are important for adaptation to drought. Many rice-growing regions face increasing water scarcity. This study describes drought responses of 11 Egyptian rice cultivars with emphasis on plastic root responses that may enhance drought adaptation.

RESULTS

Eleven Egyptian rice cultivars were phenotyped for root architectural and anatomical traits after 6 weeks growth in soil mesocosms under well-watered conditions. Four of these cultivars were more intensively phenotyped under progressive drought stress in mesocosms, using a system where more moisture was available at depth than near the surface. In response to drought stress, all cultivars significantly reduced nodal root number while increasing large lateral root branching density and total lateral root length in the deepest portions of the mesocosm, where moisture was available. Nodal root cross-sectional area, but not stele area, was reduced by drought stress, especially in the basal segments of the root, and the number of late metaxylem vessels was reduced in only one cultivar. Alterations in deposition of lignin were detected by UV illumination from laser ablation tomography, enhanced by digital staining, and confirmed with standard histochemical methods. In well-watered plants, the sclerenchyma and endodermis were heavily lignified, and lignin was also visible throughout the epidermis and cortex. Under drought stress, very little lignin was detected in the outer cell layers and none in the cortex of nodal roots, but lignin deposition was enhanced in the stele. Root anatomical phenes, including cross-section area and metaxylem vessel number and lignin deposition varied dramatically along large lateral root axes under drought stress, with increasing diameter and less lignification of the stele in successive samples taken from the base to the root apex.

CONCLUSIONS

Root architectural and anatomical traits varied significantly among a set of Egyptian cultivars. Most traits were plastic, i.e. changed significantly with drought treatment, and, in many cases, plasticity was cultivar-dependent. These phenotypic alterations may function to enhance water uptake efficiency. Increased large lateral root branching in the deep soil should maintain water acquisition, while water transport during drought should be secured with a more extensively lignified stele.

Reduced root cortical burden improves growth and grain yield under low phosphorus availability in maize

Root phenes and phene states that reduce the metabolic cost of soil exploration may improve plant growth under low phosphorus availability. We tested the hypothesis that under low phosphorus, reduced living cortical area (LCA) would increase soil exploration, phosphorus capture, biomass, and grain yield. Maize genotypes contrasting in LCA were grown in the field and in greenhouse mesocosms under optimal and suboptimal phosphorus regimes. Percent LCA in nodal roots ranged from 25% to 67%. Plants with 0.2 mm² less LCA under low phosphorus had 75% less root segment respiration, 54% less root phosphorus content, rooted 20 cm deeper, allocated up to four times more roots between 60 and 120 cm depth, had between 20% and 150% more biomass, 35-40% greater leaf phosphorus content, and 60% greater grain yield compared with plants with high LCA. Low-LCA plants had up to 55% less arbuscular mycorrhizal colonization in axial roots, but this decrease was not correlated with biomass or phosphorus content. The LCA components cortical cell file number and cortical cell size were important for biomass and phosphorus content under low phosphorus. These results are consistent with the hypothesis that root phenes that decrease the metabolic cost of soil exploration are adaptive under phosphorus stress.

Ethylene modulates root cortical senescence in barley

Background and Aims

Root cortical senescence (RCS) is a poorly understood phenomenon with implications for adaptation to edaphic stress. It was hypothesized that RCS in barley (Hordeum vulgare L.) is (1) accelerated by exogenous ethylene exposure; (2) accompanied by differential expression of ethylene synthesis and signalling genes; and (3) associated with differential expression of programmed cell death (PCD) genes.

Methods

Gene expression of root segments from four barley genotypes with and without RCS was evaluated using quantitative real-time PCR (qRT-PCR). The progression of RCS was manipulated with root zone ethylene and ethylene inhibitor applications.

Key Results

The results demonstrate that ethylene modulates RCS. Four genes related to ethylene synthesis and signalling were upregulated during RCS in optimal, low nitrogen and low phosphorus nutrient regimes. RCS was accelerated by root zone ethylene treatment, and this effect was reversed by an ethylene action inhibitor. Roots treated with exogenous ethylene had 35 and 46 % more cortical senescence compared with the control aeration treatment in seminal and nodal roots, respectively. RCS was correlated with expression of two genes related to programmed cell death (PCD).

Conclusions

The development of RCS is similar to root cortical aerenchyma formation with respect to ethylene modulation of the PCD process.