Predictors of Substance Use Initiation by Early Adolescence

OBJECTIVE

Substance use initiation during early adolescence is associated with later development of substance use and mental health disorders. This study used various domains to predict substance use initiation, defined as trying any nonprescribed substance (e.g., alcohol, tobacco, cannabis), by age 12, using a large longitudinal data set.

METHODS

Substance-naive youths from the Adolescent Brain Cognitive Development Study (ages 9-10; N=6,829) were followed for 3 years. A total of 420 variables were examined as predictors of substance use initiation, using a penalized logistic regression with elastic net; domains spanned demographic characteristics, self and peer involvement with substance use, parenting behaviors, mental and physical health, culture and environment, hormones, neurocognitive functioning, and structural neuroimaging.

RESULTS

By age 12, 982 (14.4%) children reported substance initiation, with alcohol being the most common. Models with only self-report predictors had similar prediction performance to models adding hormones, neurocognitive factors, and neuroimaging predictors (AUCtest=0.66). Sociodemographic factors were the most robust predictors, followed by cultural and environmental factors, physical health factors, and parenting behaviors. The top predictor was a religious preference of Mormon (coefficient=-0.87), followed by a religious preference for Jewish (coefficient=0.32), and by Black youths (coefficient=-0.32).

CONCLUSIONS

Sociodemographic variables were the most robust predictors of substance use initiation. Adding resource-intensive measures, including hormones, neurocognitive assessment, and structural neuroimaging, did not improve prediction of substance use initiation. The application of these large-scale findings in clinical settings could help to streamline and tailor prevention and early intervention efforts.

Adolescent alcohol use is associated with differences in the diversity and composition of the oral microbiome

BACKGROUND

Adolescence is a sensitive stage of oral microbial development that often coincides with the initiation and escalation of alcohol use. Thus, adolescents may be particularly susceptible to alcohol-induced alterations in the oral microbiome, though minimal research has been done in this area. Understanding the connection between the oral microbiome and alcohol use during adolescence is important to understand fully the biological consequences of alcohol use to mitigate potential adverse outcomes.

METHODS

Saliva samples were collected from adolescents aged 17-19 who used alcohol heavily (n = 21, 52.4% female) and those who did not use alcohol or any other substances (n = 18, 44.4% female). We utilized 16S rRNA sequencing to examine differences in microbial diversity and composition between the groups.

RESULTS

For alpha diversity, evenness was significantly lower in the drinking group than the control group as indicated by Pielou's evenness, Shannon, and Simpson indices. There were no statistically significant findings for beta diversity. Differential abundance analyses revealed higher abundances of Rothia and Corynebacterium in the alcohol-using group using both centered-log-ratio and relative abundance normalization. These genera are known for their high capacity to convert alcohol into acetaldehyde, a toxic metabolite reported to play a role in the neurobiological effects of alcohol. An unclassified Clostridia UCG-014, Streptobacillus, Comamonas, unclassified Lachnospiraceae, and Parvimonas were also identified as significantly different between groups when using only one of the normalization techniques.

CONCLUSIONS

This is the first study designed specifically to compare the oral microbiome of adolescents who use alcohol with that of control participants. Our findings reveal distinct alcohol-related differences in microbial composition and taxon abundance, emphasizing the importance of understanding the impact on the oral microbiome of alcohol use during adolescence. Because the oral microbiome is malleable, this study provides foundational work for future prevention and intervention studies.

Multi-modal neuroimaging reveals differences in alcohol-cue reactivity but not neurometabolite concentrations in adolescents who drink alcohol

BACKGROUND

The objective of this multi-modal neuroimaging study was to identify neuroscience-informed treatment targets for adolescent alcohol use disorder (AUD) by examining potential neural alterations associated with adolescent alcohol use.

METHODS

Adolescents (ages 17-19) who heavily used (n=49) or did not use alcohol (n=22) were recruited for a multi-modal neuroimaging protocol, including proton magnetic resonance spectroscopy within the dorsal anterior cingulate cortex (dACC) and an fMRI alcohol cue-reactivity task. The alcohol cue-reactivity task was analyzed across 11 a priori regions-of-interest (ROI), including the dACC, and in an exploratory whole-brain approach. Correlations were run between neurometabolite levels and alcohol cue-reactivity in the dACC.

RESULTS

There were no significant group differences in absolute neurometabolite concentrations. Compared to the control group, the alcohol-using group exhibited heightened alcohol cue reactivity in the left amygdala ROI (p=0.04). The whole-brain approach identified higher alcohol cue reactivity in the alcohol-using group compared to controls in the amygdala and occipital regions, and lower reactivity in the parietal lobe. Whole-brain sex effects were noted, with females displaying higher reactivity regardless of group. No significant correlations were found between neurometabolite levels and alcohol cue-reactivity in the dACC.

CONCLUSIONS

The null neurometabolic findings may be due to age, relatively low severity of alcohol use, and non-treatment-seeking status of the participants. Females showed overall higher reactivity to alcohol cues, indicating a sex effect regardless of alcohol use history. Higher amygdala reactivity in alcohol-using adolescents suggests that emotional processing related to alcohol cues may be a useful target for future adolescent AUD interventions.

Pairwise comparisons of three medication adherence outcomes in adolescents who use alcohol

BACKGROUND

Accurate assessment of medication adherence is important for understanding pharmacotherapy outcomes across all phases of adolescent substance use disorder (SUD) clinical trials. The objective of this study was to describe and assess the pairwise concordance between three commonly used non-biological medication adherence assessment methods in adolescents who use alcohol to inform the selection of medication adherence measures for use in future youth SUD trials.

METHODS

Participants (N = 32, 17-19-years-old) took N-acetylcysteine and placebo, in a randomized cross-over design, for 10 days each. Medication adherence was assessed (20 days total) via pill count, medication videos submitted twice daily, and the Medication Event Monitoring System (MEMS®). Lin's Concordance Correlation Coefficient (CCC) assessed concordance and Bland-Altman plots are reported. Linear mixed-effects models with main effects of medication, treatment block (first medication, second medication), and sequence were also run.

RESULTS

Medication videos yielded the lowest (64%) and pill count yielded the highest (89%) adherence estimates. CCC values indicated poor correspondence, except between pill count and MEMS. The Bland-Altman plots showed good pairwise agreement between all methods. Linear mixed-effects models indicated a difference between the first and second cross-over medication, with adherence estimates being lower for the second medication, regardless of whether it was N-acetylcysteine or placebo.

CONCLUSIONS

The study yielded important and practical information. First, incorporating more than one method of adherence assessment may capture estimated floor and ceiling adherence in the absence of a biological marker. This is particularly relevant for remote or hybrid studies where bio-marker collection is challenging. Selection of the assessment methods will depend on study goals. Second, the continuation of medication adherence research can benefit each phase of clinical trials and inform rigorous pharmacotherapy evaluation.

N-acetylcysteine does not alter neurometabolite levels in non-treatment seeking adolescents who use alcohol heavily: A preliminary randomized clinical trial

Current treatments for adolescent alcohol use disorder (AUD) are mainly psychosocial and limited in their efficacy. As such, pharmacotherapies are being investigated as potential adjunctive treatments to bolster treatment outcomes. N-acetylcysteine is a promising candidate pharmacotherapy for adolescent AUD because of its tolerability and demonstrated ability to modulate glutamatergic, GABAergic, and glutathione systems. The primary objective of this double-blind, placebo-controlled, within-subjects crossover preliminary investigation was to measure potential changes within glutamate + glutamine (Glx), GABA, and glutathione levels in the dorsal anterior cingulate cortex (dACC) using proton magnetic resonance spectroscopy during 10-days of N-acetylcysteine (1200 mg twice daily) compared to 10-days of placebo in non-treatment seeking adolescents who use alcohol heavily (N = 31; 55% female). Medication adherence was confirmed via video. Effects on alcohol use were measured using Timeline Follow-Back as an exploratory aim. Linear mixed effects models controlling for baseline metabolite levels, brain tissue composition, alcohol use, cannabis use, and medication adherence found no significant differences in Glx, GABA, or glutathione levels in the dACC after N-acetylcysteine compared to placebo. There were also no measurable effects on alcohol use; however, this finding was underpowered. Findings were consistent in the subsample of participants who met criteria for AUD (n = 19). The preliminary null findings in brain metabolite levels may be due to the young age of participants, relatively low severity of alcohol use, and non-treatment seeking status of the population investigated. Future studies can use these findings to conduct larger, well-powered studies within adolescents with AUD.

ADHD symptoms and smoking outcomes in a randomized controlled trial of varenicline for adolescent and young adult tobacco cessation

BACKGROUND

Most adult daily smokers try their first cigarette during adolescence. Attention-Deficit Hyperactivity Disorder (ADHD) in adolescents is associated with increased risk for cigarette smoking. The impact of ADHD symptoms on smoking cessation among adolescents has been less well-studied. The present secondary data analysis from a clinical trial of varenicline examined ADHD symptoms as a moderator of smoking cessation in adolescents and young adults.

METHODS

The double-blind, placebo-controlled trial included treatment-seeking daily cigarette smokers ages 14 - 21 (N = 157) randomized to receive a 12-week course of varenicline or placebo, added to weekly smoking cessation counseling. At pre-treatment assessment, participants were administered a self-report measure of ADHD symptoms, the ADHD - Rating Scale (ADHD-RS). High (≥5) versus low (<5) and continuous ADHD-RS symptom counts in both hyperactive/impulsive (HI) and inattention (IA) domains were examined as predictors of smoking outcomes.

RESULTS

Participants with high IA symptoms at baseline were less likely to achieve 7-day point prevalence abstinence (PPA) at weekly visits (p = .001) during active treatment and end-of-treatment (p = .002) compared to those with low IA symptoms. In contrast, high HI symptoms did not predict differences in 7-day PPA or end-of-treatment abstinence versus low symptoms (p's ≥ .07). These findings were not modified by varenicline versus placebo treatment assignment.

CONCLUSIONS

ADHD IA symptoms were associated with poorer cessation outcomes among adolescent smokers. These findings warrant additional investigation into how ADHD symptoms may be accounted for in smoking cessation interventions for adolescents and young adults.

Associations of Maternal Prenatal Stress and Depressive Symptoms With Childhood Neurobehavioral Outcomes in the ECHO Cohort of the NICHD Fetal Growth Studies: Fetal Growth Velocity as a Potential Mediator

OBJECTIVE

Maternal prenatal stress and mood symptoms are associated with risk for child psychopathology. Within the Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD) Fetal Growth Studies (ECHO-FGS), a racially and ethnically diverse cohort, we studied associations between prenatal stress and depressive symptoms with child neurobehavior, and potential mediation by fetal growth velocity (FGV) in low-risk pregnancies.

METHOD

For 730 mother-child pairs, we had serial ultrasound measurements, self-reports of prenatal stress and depression, observations of child executive functions and motor skills from 4 to 8 years, and maternal reports of child psychiatric problems. We tested associations between prenatal stress and depressive symptoms with child neurobehavior in regression analyses, and associations with FGV in mixed effect models. Post hoc we tested severity of prenatal symptoms; FGV at 25th, 50th, and 75th percentiles; and moderation by biological sex and by race and ethnicity.

RESULTS

Prenatal stress and depressive symptoms were associated with child psychiatric problems, and prenatal depressive symptoms with decrements in executive functions and motor skills, especially in biological male children. Neither prenatal stress nor depressive symptoms were associated with FGV.

CONCLUSION

In one of the largest cohorts with observed child outcomes, and the first with broad representation of race and ethnicity in the United States, we found that prenatal stress and depressive symptoms were associated with greater reports of child psychiatric symptoms. Only prenatal depressive symptoms were associated with observed decrements in cognitive abilities, most significantly in biological male children. Stress during low-risk pregnancies may be less detrimental than theorized. There was no mediation by FGV. These findings support the need to attend to even small changes in prenatal distress, as these may have long-lasting implications.

The association between maternal pre-pregnancy BMI, gestational weight gain and child adiposity: A racial-ethnically diverse cohort of children

BACKGROUND

The prevalence of obesity in US children has more than tripled in the past 40 years; hence, it is critical to identify potentially modifiable factors that may mitigate the risk.

OBJECTIVES

To examine the association between maternal pre-pregnancy body mass index (BMI), gestational weight gain (GWG) and child adiposity as measured by BMI, waist circumference and percent body fat in a racial-ethnically diverse cohort.

METHODS

In a prospective cohort study of healthy women without chronic disease, we examined the association between pre-pregnancy BMI, GWG and child adiposity. Children ages 4-8 years (n = 816) in the Environmental Influences on Child Health Outcomes-NICHD Fetal Growth Studies were assessed. Trained study staff ascertained maternal pre-pregnancy BMI, GWG and child adiposity.

RESULTS

The odds of child obesity (≥95th BMI percentile) increased independently for each unit increase in maternal pre-pregnancy BMI [OR = 1.12 (95% CI: 1.08, 1.17)] and for each 5-kg increase in GWG [OR = 1.25 (95% CI: 1.07, 1.47)]. The odds of child waist circumference (≥85th percentile) also increased independently for pre-pregnancy BMI [OR = 1.09 (95% CI: 1.05, 1.12)] and GWG [OR = 1.18 (95% CI: 1.04, 1.34)].

CONCLUSIONS

Maternal pre-pregnancy BMI and GWG were each independently and positively associated with child obesity and high child waist circumference.

Per- and polyfluoroalkyl substances (PFAS) in river discharge: Modeling loads upstream and downstream of a PFAS manufacturing plant in the Cape Fear watershed, North Carolina

The Cape Fear River is an important source of drinking water in North Carolina, and many drinking water intakes in the watershed are affected by per- and polyfluoroalkyl substances (PFAS). We quantified PFAS concentrations and loads in river water upstream and downstream of a PFAS manufacturing plant that has been producing PFAS since 1980. River samples collected from September 2018 to February 2021 were analyzed for 13 PFAS at the upstream station and 43-57 PFAS downstream near Wilmington. Frequent PFAS sampling (daily to weekly) was conducted close to gauging stations (critical to load estimation), and near major drinking water intakes (relevant to human exposure). Perfluoroalkyl acids dominated upstream while fluoroethers associated with the plant made up about 47% on average of the detected PFAS downstream. Near Wilmington, Σ₄₃PFAS concentration averaged 143 ng/L (range 40-377) and Σ₄₃PFAS load averaged 3440 g/day (range 459-17,300), with 17-88% originating from the PFAS plant. LOADEST was a useful tool in quantifying individual and total quantified PFAS loads downstream, however, its use was limited at the upstream station where PFAS levels in the river were affected by variable inputs from a wastewater treatment plant. Long-term monitoring of PFAS concentrations is warranted, especially at the downstream station. Results suggest a slight downward trend in PFAS levels downstream, as indicated by a decrease in flow-weighted mean concentrations and the best-fitting LOADEST model. However, despite the cessation of PFAS process wastewater discharge from the plant in November 2017, and the phase-out of perfluorooctane sulfonic acid (PFOS) and perfluorooctanoic acid (PFOA) in North America, both fluoroethers and legacy PFAS continue to reach the river in significant quantities, reflecting groundwater discharge to the river and other continuing inputs. Persistence of PFAS in surface water and drinking water supplies suggests that up to 1.5 million people in the Cape Fear watershed might be exposed.

Breastfeeding Associations with Childhood Obesity and Body Composition: Findings from a Racially Diverse Maternal-Child Cohort

Background: Studies suggest breastfeeding lowers obesity risk in childhood, but generalizability of existing evidence is limited. We examined associations of breastfeeding with childhood overweight, obesity, and percentage body fat, in a racially diverse maternal-child cohort. Methods: This cross-sectional study included 823 children, ages 4-8 years, enrolled in the Environmental Exposures and Child Health Outcomes (ECHO) cohort, a subset of the National Institute of Child Health and Human Development Fetal Growth Studies cohort. Logistic regression was used to estimate odds ratios and 95% confidence intervals (CIs) for overweight [BMI (kg/m²) 85th to <95th percentile] and obesity (BMI ≥95th percentile) in relation to breastfeeding including duration of exclusive and total breastfeeding. Linear regression was used to evaluate association between breastfeeding and percentage body fat measured by bioelectrical impedance analysis. Results: Fifty-two percent of children were male, 32% non-Hispanic Black, 29% Hispanic, 27% non-Hispanic White, and 13% Asian; 16% were overweight and 13% obese. Six months of exclusive breastfeeding, compared with no breastfeeding, was associated with 60% lower odds of obesity (95% CI 0.18-0.91) adjusting for age, gender, race, socioeconomic status, maternal BMI, and child's activity. Percentage body fat was inversely associated with breastfeeding duration. For none, <6, and ≥6 months of exclusive breastfeeding, adjusted mean percentage body fat was 16.8, 14.5, and 13.4, respectively. Results did not differ by gender, race/ethnicity, or maternal BMI status. Conclusions: Exclusive breastfeeding for the first 6 months of life is inversely and significantly associated with obesity and percentage body fat at ages 4-8 years. These findings support current breastfeeding guidelines.

The Association of Traumatic Brain Injury, post-traumatic stress disorder, and criminal recidivism

BACKGROUND

The purpose of the study was to assess the prevalence of traumatic brain injury (TBI) and post-traumatic stress disorder (PTSD) and to determine whether TBI or PTSD is associated with an increase in general or violent criminal recidivism among a representative sample of released prisoners. In-person interviews were conducted with a stratified random sample of individuals incarcerated with the South Carolina Department of Corrections approximately 90 days prior to the prisoners' releases. In addition to a variety of items and scales, respondents were screened for TBI and were asked whether they had received a current diagnosis of PTSD. Data were merged with arrest data that provided measures of past criminal involvement and indicators of post-release recidivism (arrest). Arrests were coded as "general" for any arrest charge and "violent" for any violent offense charge.

RESULTS

Survival analyses indicate that neither TBI nor PTSD predicts time to general recidivism. PTSD (p < 0.01) and age at first arrest (p < 0.01) are significant predictors for violent recidivism and TBI is non-significant at p = 0.09. Results from the negative binomial models indicate that TBI (p < 0.05) and PTSD (p < 0.05) are significantly associated with more post-release violent arrests, but not general arrests.

CONCLUSIONS

TBI and PTSD were found to predict violent offending but not general criminal behavior. These findings demonstrate the need for prison officials to identify individuals with a history of TBI and PTSD and to develop appropriate interventions that could be provided during incarceration to reduce the post-release likelihood of violence.

Association between gestational PFAS exposure and Children's adiposity in a diverse population

Perfluoroalkyl substances (PFAS) are widely distributed suspected obesogens that cross the placenta. However, few data are available to assess potential fetal effects of PFAS exposure on children's adiposity in diverse populations. To address the data gap, we estimated associations between gestational PFAS concentrations and childhood adiposity in a diverse mother-child cohort. We considered 6 PFAS in first trimester blood plasma, measured using ultra-high-performance liquid chromatography with tandem mass spectrometry, collected from non-smoking women with low-risk singleton pregnancies (n = 803). Body mass index (BMI), waist circumference (WC), fat mass, fat-free mass, and % body fat were ascertained in 4-8 year old children as measures of adiposity. We estimated associations of individual gestational PFAS with children's adiposity and overweight/obesity, adjusted for confounders. There were more non-Hispanic Black (31.7 %) and Hispanic (42.6 %) children with overweight/obesity, than non-Hispanic white (18.2 %) and Asian/Pacific Islander (16.4 %) children (p < 0.0001). Perfluorooctane sulfonate (PFOS; 5.3 ng/mL) and perfluorooctanoic acid (2.0 ng/mL) had the highest median concentrations in maternal blood. Among women without obesity (n = 667), greater perfluoroundecanoic acid (PFUnDA) was associated with their children having higher WC z-score (β = 0.08, 95%CI: 0.01, 0.14; p = 0.02), fat mass (β = 0.55 kg, 95%CI: 0.21, 0.90; p = 0.002), and % body fat (β = 0.01 %; 95%CI: 0.003, 0.01; p = 0.004), although the association of PFUnDA with fat mass attenuated at the highest concentrations. Among women without obesity, the associations of PFAS and their children's adiposity varied significantly by self-reported race-ethnicity, although the direction of the associations was inconsistent. In contrast, among the children of women with obesity, greater, PFOS, perfluorononanoic acid, and perfluorodecanoic acid concentrations were associated with less adiposity (n = 136). Our results suggest that specific PFAS may be developmental obesogens, and that maternal race-ethnicity may be an important modifier of the associations among women without obesity.

Early Exposure to Animals and Childhood Body Mass Index Percentile and Percentage Fat Mass

INTRODUCTION

A few studies have identified childhood animal exposure as associated with adiposity, but results are inconsistent and differ in timing.

METHODS

We conducted an observational cohort study of children ages 4-8 in the Environmental Influences on Child Health Outcomes [ECHO] study. The main exposure was having a dog in the home and/or regular contact with farm animals during the first year of life. Outcomes of interest were child BMI percentile (adjusted for gender and age) categorized as normal/underweight (<85^th percentile), overweight (85^th to <95^th), and obese (≥95^th), and percent fat mass (continuous). Associations were analyzed using multinomial logistic regression and multivariable linear regression, respectively, with and without multiple imputation.

RESULTS

First year animal exposure occurred in 245 of 770 (31.8%) children. Children with early animal exposure had 0.53 (95% CI: 0.28, 0.997) times the odds of being in the obese BMI category compared to those exposed to animals after controlling for covariates: maternal pre-pregnancy BMI, race/ethnicity, reported child activity level, receiving food assistance, age child began daycare (<1 year vs 1+), exclusively breastfed x6 months, and NICU admission (n=721). Children with early animal exposure had, on average, 1.5% (95% CI: -3.0, -0.1) less fat mass than exposed children after adjustment for maternal BMI, race/ethnicity, activity, food assistance, breastfeeding, and maternal education (n=548). Multiple imputation did not alter either result.

CONCLUSION

These results provide evidence that exposure to dogs or farm animals in the first year of life is associated with lower odds of obesity and lower percent fat mass in childhood.

Reported Neighborhood Traffic and the Odds of Asthma/Asthma-Like Symptoms: A Cross-Sectional Analysis of a Multi-Racial Cohort of Children

Asthma in children poses a significant clinical and public health burden. We examined the association between reported neighborhood traffic (a proxy for traffic-related air pollution) and asthma among 855 multi-racial children aged 4-8 years old who participated in the Environmental Influences on Child Health Outcomes (ECHO) cohort. We hypothesized that high neighborhood traffic density would be associated with the prevalence of asthma. Asthma/asthma-like symptoms (defined as current and/or past physician diagnosed asthma, past wheezing, or nighttime cough or wheezing in the past 12 months) was assessed by parental report. The relationship between neighborhood traffic and asthma/asthma-like symptoms was assessed using logistic regression. The prevalence of asthma/asthma-like symptoms among study participants was 23%, and 15% had high neighborhood traffic. Children with significant neighborhood traffic had a higher odds of having asthma/asthma-like symptoms than children without neighborhood traffic [adjusted OR = 2.01 (95% CI: 1.12, 3.62)] after controlling for child's race-ethnicity, age, sex, maternal education, family history of asthma, play equipment in the home environment, public parks, obesity and prescribed asthma medication. Further characterization of neighborhood traffic is needed since many children live near high traffic zones and significant racial/ethnic disparities exist.

"That Can't Be!": Perceptions of HIV and Hepatitis C Screening during Admission to an Acute Care Surgery Service

Background:

A large number of patients live with undiagnosed HIV and/or hepatitis C despite broadened national screening guidelines. European studies, however, suggest many patients falsely believe they have been screened during a prior hospitalization. This study aims to define current perceptions among trauma and emergency general surgery (EGS) patients regarding HIV and hepatitis C screening practices.

Methods:

Prospective survey administered to adult (>18 years old) acute care surgery service (trauma and EGS) patients at a Level 1 academic trauma center. The survey consisted of 13 multiple choice questions: demographics, whether admission tests included HIV and hepatitis C at index and prior hospital visits and whether receiving no result indicated a negative result, prior primary care screening. Response percentages calculated in standard fashion.

Results:

One hundred and twenty-five patients were surveyed: 80 trauma and 45 EGS patients. Overall, 32% and 29.6% of patients believed they were screened for HIV and hepatitis C at admission. There was no significant difference in beliefs between trauma and EGS. Sixty-eight percent of patients had a hospital visit within 10 years of these, 49.3% and 44.1% believe they had been screened for HIV and hepatitis C. More EGS patients believed they had a prior screen for both conditions. Among patients who believed they had a prior screen and did not receive any results, 75.9% (HIV) and 80.8% (hepatitis C) believed a lack of results meant they were negative. Only 28.9% and 23.6% of patients had ever been offered outpatient HIV and hepatitis C screening.

Conclusions:

A large portion of patients believe they received admission or prior hospitalization HIV and/or hepatitis C screening and the majority interpreted a lack of results as a negative diagnosis. Due to these factors, routine screening of trauma/EGS patients should be considered to conform to patient expectations and national guidelines, increase diagnosis and referral for medical management, and decrease disease transmission.

Identifying chronic heavy alcohol use in emergency general surgery patients: a pilot study

Background

Chronic heavy alcohol (CHA) use has been associated with perioperative complications. Emergency general surgery (EGS) patients are not routinely screened for CHA. If screened, it is usually for hazardous use of alcohol, using a survey such as the Alcohol Use Disorders Identification Test (AUDIT). This study screened EGS patients for CHA use using serum carbohydrate-deficient transferrin (%dCDT) level, a biomarker that has been validated as an indicator for CHA use, as well as the AUDIT. The purpose of this study was to determine the percent of EGS patients with CHA (as indicated by elevated %dCDT), and the relationship between %dCDT and AUDIT. Secondary aims included comparing the characteristics of EGS patients with and without CHA use, and evaluating the association of CHA use with negative clinical outcomes.

Methods

EGS patients aged 21 and older admitted to the general surgery inpatient service of a tertiary hospital from July 2014 to June 2016 were invited to participate in this study. %dCDT levels above 1.7% were considered positive for CHA use, as were AUDIT scores ≥8.

Results

195 EGS patients were screened for inclusion and 91 (46.7%) agreed to participate. 14 (15.4%) were positive for hazardous alcohol use on AUDIT and 5 (5.5%) were positive for CHA by %dCDT. Positive predictive value of AUDIT for CHA was 21.4%. There was no correlation between positive scores on AUDIT and %dCDT.

Discussion

Identifying at risk patients early on in their hospital course may allow clinicians to institute treatments to mitigate and/or circumvent complications in such patients. This pilot study determined that 17.6% of participating EGS patients were positive for some type of alcohol misuse, but only 5.5% had CHA. Further research is needed to determine whether routine use of %dCDT would be beneficial in reducing perioperative complications in this patient population.

Level of evidence

III (diagnostic test).

Continuing Trauma: The Unmet Needs of Trauma Patients in the Postacute Care Setting

Trauma care has traditionally focused on prehospital and hospital settings, yet many injured patients report emotional distress in the postacute care setting, which is known to impair recovery. The objective of this study was to assess postdischarge emotional recovery and communication preferences. An observational cohort of 100 adult patients from our Level 1 Trauma Center was surveyed one to two months postdischarge. Among those employed preinjury, 44 per cent had not returned to work. Nearly half screened positive for emotional issues (posttraumatic stress disorder, depression, and/or psychological distress); of these, only 35 per cent considered getting professional help and only 10 per cent received help. The barrier most cited (58%) was cost; 42 per cent did not know how or where to get help. Most participants responded “no” or “I don't know” when asked if they had received information about coping with negative emotions after injury and how to seek help from a doctor to address these emotions. Two-thirds preferred to receive such information via phone call from a health care provider or by text. Eighty-nine per cent owned a cellphone. Our trauma systems are failing to provide comprehensive care or look at the ultimate outcomes of our patients, yet modern technology could provide needed resources to patients in novel ways.

Continuing Trauma: The Unmet Needs of Trauma Patients in the Postacute Care Setting

Trauma care has traditionally focused on prehospital and hospital settings, yet many injured patients report emotional distress in the postacute care setting, which is known to impair recovery. The objective of this study was to assess postdischarge emotional recovery and communication preferences. An observational cohort of 100 adult patients from our Level 1 Trauma Center was surveyed one to two months postdischarge. Among those employed preinjury, 44 per cent had not returned to work. Nearly half screened positive for emotional issues (posttraumatic stress disorder, depression, and/or psychological distress); of these, only 35 per cent considered getting professional help and only 10 per cent received help. The barrier most cited (58%) was cost; 42 per cent did not know how or where to get help. Most participants responded "no" or "I don't know" when asked if they had received information about coping with negative emotions after injury and how to seek help from a doctor to address these emotions. Two-thirds preferred to receive such information via phone call from a health care provider or by text. Eighty-nine per cent owned a cellphone. Our trauma systems are failing to provide comprehensive care or look at the ultimate outcomes of our patients, yet modern technology could provide needed resources to patients in novel ways.

Hospitalization in low-level trauma centres after severe traumatic brain injury: review of a population-based emergency department data base

OBJECTIVE

To achieve the best possible recovery, individuals with severe TBI should be treated at Level I/II trauma centres (I/II TC). Increased morbidity and mortality can result when injured patients are admitted to facilities that may not have the appropriate resources or expertise to treat the injury. The purpose of this study was to estimate the proportion of severe TBI visits resulting in hospitalization in lower-level trauma centres (OTH) and evaluate the characteristics associated with such hospitalizations.

METHODS

The 2012 National Emergency Department Sample (NEDS) data set was analysed. Weighted descriptive analysis and multivariable logistic regression were used to describe the association of hospitalization in OTH with demographic, clinical and hospital characteristics.

RESULTS

Of visits for severe TBI, 112 208 were admitted to I/II TC and 43 294 admitted to OTH. The adjusted odds of hospitalization in OTH were higher for isolated TBI, falls, women, in those with ≥3 chronic conditions and increasing age.

CONCLUSIONS

An estimated 19.5% of visits for severe TBI resulted in hospitalization in OTH. These findings show the need to further evaluate the relationship between sex, age and mechanism of injury to inform efforts to appropriately triage individuals with TBI to ensure the best possible recovery.

Pharmacologic Stress Gastropathy Prophylaxis May Not Be Necessary in At-Risk Surgical Trauma ICU Patients Tolerating Enteral Nutrition

OBJECTIVE

Stress gastropathy is a rare complication of the intensive care unit stay with high morbidity and mortality. There are data that support the concept that patients tolerating enteral nutrition have sufficient gut blood flow to obviate the need for prophylaxis; however, no robust studies exist. This study assesses the incidence of clinically significant gastrointestinal bleeding in surgical trauma intensive care unit (STICU) patients at risk of stress gastropathy secondary to mechanical ventilation receiving enteral nutrition without pharmacologic prophylaxis.

DESIGN

A retrospective cohort study of records from 2008 to 2013.

SETTING

Adult patients in a single-center STICU were included.

PATIENTS

Patients were included if they received full enteral nutrition while on mechanical ventilation. Exclusion criteria were coagulopathy, glucocorticoid use, prior-to-admission acid-suppressive therapy use, direct trauma or surgery to the stomach, failure to tolerate goal enteral nutrition, orders to allow natural death, and deviation from the intervention.

INTERVENTION

Pharmacologic stress ulcer prophylaxis was discontinued once enteral nutrition was providing full caloric requirements for patients requiring mechanical ventilation.

MEASUREMENTS AND MAIN RESULTS

A total of 200 patients were included. The median age was 42 years, 83.0% were male, and 96.0% were trauma patients. The incidence of clinically significant gastrointestinal bleeding was 0.50%, with a subset analysis of traumatic brain injury patients yielding an incidence of 0.68%. Rates of ventilator-associated pneumonia and Clostridium difficile infection were low at 1.0 case/1000 ventilator days and 0.2 events/1000 patient days, respectively. Hospital all-cause mortality was 2.0%. Cost savings of US$121/patient stay were realized.

CONCLUSION

Stress gastropathy is rare in this population. Surgical and trauma patients at risk for stress gastropathy did not benefit from continued pharmacologic prophylaxis once they tolerated enteral nutrition. Pharmacologic prophylaxis may safely be discontinued in this patient population. Further investigation is warranted to determine whether continued prophylaxis after attaining enteral feeding goals is detrimental.

Behavioral health referrals in pediatric epilepsy

The purpose of this study was to examine the feasibility of a behavioral health referral protocol and barriers to behavioral health care in a pediatric epilepsy clinic. A sample of 93 youth with epilepsy ages 10-17 and caregivers completed behavioral health and seizure severity measures during a routine epilepsy clinic visit. Key findings are that 47 (50.5%) of the youth screened positive for a behavioral health referral, and 35 of these youth were referred for behavioral health services. However, only 20% made and presented for the behavioral health appointment. The most commonly cited barrier for accessing and utilizing behavioral health care was stigma related- a mental health label for the child. The significance of this study lies in the revelation that solely screening for and educating caregivers about behavioral health symptoms and providing behavioral health referral information is not an ideal model. Instead, stigma related barriers point to the necessity of continued integrated physical and behavioral health care within the pediatric epilepsy visit.

Relationships Between Traumatic Brain Injury and Illicit Drug Use and Their Association With Aggression in Inmates

Extensive interviews of correctional inmates in South Carolina (2009-2010) were conducted under a Center for Disease Control and Prevention (CDC) grant. We evaluated the extent to which early traumatic brain injury (TBI) and subsequent illicit drug abuse may conjointly influence development of aggression, controlling for alcohol use, and whether cognitive or emotional dysregulation mediated this relationship. Early TBI predicted greater severity and earlier onset of drug use, and an earlier age at first use predicted greater aggression regardless of the age of TBI. Emotional dysregulation mediated effects of TBI on aggression. The potential to design more targeted treatments for this susceptible population are discussed.

A New Perspective on Sustainable Soil Remediation-Case Study Suggests Novel Fungal Genera Could Facilitate in situ Biodegradation of Hazardous Contaminants

Deciding upon a cost effective and sustainable method to address soil pollution is a challenge for many remedial project managers. High pressure to quickly achieve cleanup goals pushes for energy-intensive remedies that rapidly address the contaminants of concern with established technologies, often leaving little room for research and development especially for slower treatment technologies, such as bioremediation, for the more heavily polluted sites. In the present case study, new genomic approaches have been leveraged to assess fungal biostimulation potential in soils polluted with particularly persistent hydrophobic contaminants. This new approach provides insights into the genetic functions available at a given site in a way never before possible. In particular, this article presents a case study where next generation sequencing (NGS) has been used to categorize fungi in soils from the Atlantic Wood Industries Superfund site in Portsmouth, Virginia. Data suggest that original attempts to harness fungi for bioremediation may have focused on fungal genera poorly suited to survive under heavily polluted site conditions, and that more targeted approaches relying on native indigenous fungi which are better equipped to survive under site specific conditions may be more appropriate.

A feasibility pilot study on the use of text messages to track PTSD symptoms after a traumatic injury

OBJECTIVE

Monitoring posttraumatic stress disorder (PTSD) symptoms after a traumatic injury is beneficial for patients and providers. Text messages can be used to automatically monitor symptoms and impose minimal burden to patients and providers. The present study piloted such a strategy with traumatic injury patients.

METHOD

An automated daily text message was piloted to evaluate PTSD symptoms after discharge from the hospital. Twenty-nine patients who experienced a traumatic injury received 15 daily texts and were then followed up at 1-month and 3-months after discharge.

RESULTS

82.8% of the sample responded at least once and the average response rate per participant was 63.1%. Response rates were correlated with PTSD symptoms at baseline but not at any other time. Patient satisfaction with this approach was high.

CONCLUSION

Text messages are a viable method to monitor PTSD symptoms after a traumatic injury. Such an approach should be evaluated on a larger scale as part of a more comprehensive early intervention for traumatic stress.

Preliminary Psychometrics of the Neurological Disorders Depression Inventory for Epilepsy-Youth

The authors examined the preliminary psychometrics of a depression screening tool for youth with epilepsy. Development involved content analysis, cognitive interviewing, and qualitative analysis. Ninety-three youths with epilepsy aged 10 to 17 years completed the Neurological Disorders Depression Inventory for Epilepsy-Youth and the depression module of a standardized clinical interview. Caregivers rated seizure severity and completed the Pediatric Symptom Checklist. Results indicated strong reliability indices, including test-retest, κ value, and internal consistency for the Neurological Disorders Depression Inventory for Epilepsy-Youth. It was significantly associated with the other measures of depression and psychosocial functioning. Factor analyses revealed a 1-factor solution for 9 items, with 35.7% of the variance explained. An optimal cutoff score of 27 resulted in a sensitivity index of 0.80 and a specificity index of 0.71. The Neurological Disorders Depression Inventory for Epilepsy-Youth is a screening tool that can be utilized in routine epilepsy care, but further evaluation is necessary.

Proportional costs in trauma and acute care surgery patients: dominant role of intensive care unit costs

BACKGROUND

Controlling inpatient costs is increasingly important. Identifying proportionately larger cost categories may help focus cost control efforts. The purpose of this study was to identify proportionate patient cost categories in trauma and acute care surgery (TACS) patients and determine subgroups in which the largest opportunities for cost savings might exist.

STUDY DESIGN

Administrative data from our academic, urban, level I trauma center were used to identify all adult TACS patients from FY07 through FY11. We determined, on average, what proportion of the whole each cost category contributed to patients' total costs and examined the same proportions for subgroups of patients.

RESULTS

We identified 6,008 TACS patients. Trauma patients (n = 3,904) made up 65% of the cohort (mean Injury Severity Score 13.2). Payers were: 22% government (Medicare, Medicaid, Champus), 27% private, 43% self-pay/indigent, 3% other, and 5% workers compensation. Nontrauma (general surgery) patients (n = 2,104) made up 35% of the cohort. Payers were: 44% government, 24% private, 29% self-pay/indigent, 2% other, and 1% workers compensation. Total inpatient costs were $141,304,993. Per patient costs rose from $17,245 in FY07 to $26,468 in FY11. In the aggregate, supplies, ICU stays, and ward stays represented the largest proportionate cost categories. On a per patient basis, however, ICU stays were by far the largest cost. Patients with ICU stay greater than 10 days were only 7% of all patients but accounted for 41% of total costs.

CONCLUSIONS

Trauma and acute care surgery patients represent a significant and increasing institutional cost. Per patient ICU costs were the largest single category, suggesting that cost control efforts should focus heavily on critically ill patients. Nontrauma patients who require critical care have the highest per patient ICU costs and may represent a previously underappreciated opportunity for cost control.

The relationship of coping behaviors to depressive symptoms in youth with epilepsy: an examination of caregiver and youth proxy report

Study aims were to explore evaluation and comparison of measures of coping and the relationship of epilepsy-specific coping responses to depressive symptoms in youth with epilepsy (YWE). Seventy-six YWE ages 9-17 completed the Children's Depression Inventory (CDI) and the Kidcope. Sixty-six caregivers reported on youth coping (CHIC) and seizure activity. Epilepsy variables were abstracted from electronic medical records. There were no significant correlations between the CHIC coping factors and individual Kidcope scores. Only one CHIC factor, "competence/optimism," was significantly negatively correlated with CDI. Regression analyses revealed a significant association between CDI and negative coping (Kidcope) after adjusting for sex, number of AEDs, and seizure severity. On the CDI, 27% of YWE endorsed suicidal ideation. Findings provide preliminary support for use of the Kidcope as a measure of negative epilepsy-specific coping. These results imply that youth coping and suicidal ideation are important to assess in relation to depressive symptoms and that youth report of these symptoms is particularly salient to the evaluation of youth functioning.

Association of medically attended traumatic brain injury and in-prison behavioral infractions: a statewide longitudinal study

This study examined the association between medically attended traumatic brain injury (TBI) and in-prison behavioral infractions in a statewide population by comparing rate ratios of infractions in inmates with and without TBI over an 11.5-year period (16,299 males and 1,270 females). The in-prison behavioral infraction rate was significantly increased in males with TBI compared with no TBI for all infractions (RR = 1.32, 95% CI: 1.12, 1.55), violent infractions (RR = 1.86, 95% CI: 1.54, 2.24), and nonviolent infractions (RR = 1.19, 95% CI: 1.00, 1.41). The violent behavioral infraction rate was significantly increased in females with TBI compared with no TBI (RR = 2.44, 95% CI: 1.45, 4.12). A clearer understanding of inmates with a history of TBI and further examination of the association of TBI and behavioral infractions are needed.

Psychosocial factors associated with stigma in adults with epilepsy

Living Well with Epilepsy II called for further attention to stigma and its impact on people with epilepsy. In response, the South Carolina Health Outcomes Project on Epilepsy (SC HOPE) is examining the relationship between socioeconomic status, epilepsy severity, health care utilization, and quality of life in persons diagnosed with epilepsy. The current analysis quantifies perceived stigma reported by adults with epilepsy in relation to demographic, seizure-related, health, and psychosocial factors. It was found that reported levels of stigma were associated with interactions of seizure worry and employment status, self-efficacy and social support, and quality care and age at seizure onset. This information may be used to target and develop evidence-based interventions for adults with epilepsy at high risk for perceived stigma, as well as to inform epilepsy research in self-management.

A population-based study of risk of epilepsy after hospitalization for traumatic brain injury

PURPOSE

This study was undertaken to determine the risk of developing posttraumatic epilepsy (PTE) within 3 years after discharge among a population-based sample of older adolescents and adults hospitalized with traumatic brain injury (TBI) in South Carolina. It also identifies characteristics related to development of PTE within this population.

METHODS

A stratified random sample of persons aged 15 and older with TBI was selected from the South Carolina nonfederal hospital discharge dataset for four consecutive years. Medical records of recruits were reviewed, and they participated in up to three yearly follow-up telephone interviews.

RESULTS

The cumulative incidence of PTE in the first 3 years after discharge, after adjusting for loss to follow-up, was 4.4 per 100 persons over 3 years for hospitalized mild TBI, 7.6 for moderate, and 13.6 for severe. Those with severe TBI, posttraumatic seizures prior to discharge, and a history of depression were most at risk for PTE. This higher risk group also included persons with three or more chronic medical conditions at discharge.

DISCUSSION

These results raise the possibility that although some of the characteristics related to development of PTE are nonmodifiable, other factors, such as depression, might be altered with intervention. Further research into factors associated with developing PTE could lead to risk-reducing treatments.

Impact of pediatric epilepsy: voices from a focus group and implications for public policy change

Epilepsy affects approximately 0.5-1% of youth, and challenges for them and their families reach far beyond seizures. Quantitative studies have shown that in addition to increased risk for psychosocial difficulties, many experience stigma and barriers to services and resources. As a complement to quantitative analyses, qualitative research further provides unique insight into understanding the impact of epilepsy on youth and families. In the present study, focus groups were held to discuss families' experiences with epilepsy and access to related services. Qualitative analysis revealed three themes highlighting medical, educational, and social challenges of youth with epilepsy. Implications include recommendations for improvements in public awareness and public policy change.

A hopelessness model of depressive symptoms in youth with epilepsy

OBJECTIVE

To test the cognitive diathesis-stress and mediational components of the theory of learned hopelessness in youth with epilepsy.

METHODS

Seventy-seven participants ages 9-17 (35 girls, 42 boys) completed measures of depressive symptoms, hopelessness, self-efficacy for seizure management, and attitude toward epilepsy. Caregivers provided information on seizure activity. Diagnostic and treatment information was obtained via medical record review.

RESULTS

Regression analyses revealed that hopelessness mediated the attitude towards epilepsy-depressive symptom relationship. While attitude toward epilepsy and self-efficacy were independent predictors of depressive symptoms, the relationship of attitudes toward epilepsy and depressive symptoms was not enhanced with low self-efficacy for seizure management.

CONCLUSIONS

Findings support the mediation component of the learned hopelessness theory in youth with epilepsy, suggesting the importance of interventions that assist youth in identifying epilepsy-related aspects of functioning over which they can realistically exercise control and challenging negative thoughts about situations they cannot control.

Experiences of persons with epilepsy and their families as they look for medical and community care: a focus group study from South Carolina

Epilepsy affects a larger number of individuals than previously thought-up to 2% of the population-and its effects reach further. Yet epilepsy, with its associated lingering stigma and fear, has remained in the background in terms of services and research. Traditional quantitative research often falls short when trying to describe the impact of epilepsy on the lives of individuals and their families. In the present study, focus groups were held throughout South Carolina to discuss individuals' experiences with accessing epilepsy-related services and health care, and what life with epilepsy is like. Following qualitative data analysis, findings included two themes. One theme focuses on the ongoing search for services and help. The second theme concerns the experiences of living life with epilepsy. Also highlighted are recommendations for potential improvements in public awareness and professional training, and helpful interventions.

Why pulmonary tuberculosis recurs: a population-based epidemiological study

PURPOSE

To evaluate the factors associated with recurrent pulmonary tuberculosis using a well-defined, population-based tuberculosis registry system.

METHODS

A case-control study of persons with recurrent pulmonary tuberculosis cases (n=437) and systematically sampled nonrecurrent controls (n=442) matched by year of initial diagnosis in South Carolina. Data were acquired from the tuberculosis registry and medical chart reviews. Conditional logistic regression was used to model the relationship between recurrent disease and clinical and demographic characteristics in a multivariable analysis.

RESULTS

From 1970 through 2002, there were 15,464 pulmonary tuberculosis patients, of which 2.9% were recurrent disease. After adjusting for the covariates, odds ratios (OR) and 95% confidence intervals (95% CI) for suboptimal therapy was 6.4 (3.9-10.5), alcoholism 3.9 (2.5-6.1), interaction between treatment duration exceeding 24 months and poor compliance 3.8 (2.4-4.3), and age older than 65 years 1.9 (1.2-2.9). Our study noted an interaction between poor patient compliance and duration of treatment.

CONCLUSION

Treatment regimen, duration of treatment, compliance, alcoholism, and older age are strong predictors of recurrent disease. Reinforcing the tuberculosis treatment guideline and applications of directly observed therapy have to remain integral components of tuberculosis control and elimination program.

Low birth weight as a risk factor for hypertension

While the geographic and demographic disparities in the prevalence of hypertension have been recognized for decades, the reasons for these differences in disease risks remain unknown. The demographic and geographic patterns of hypertension are similar to those of low birth weight, giving support to the "Barker Hypothesis" which proposes a fetal origin of adult-onset disease. In fact, ecologic and observational studies throughout the world have detected significant associations of low birth weight and increased risks of hypertension. Nonetheless, the mechanisms for the association have not been fully described and documented. With some supportive evidence, proposed mechanisms include reduced nephrogenesis with a higher threshold for pressure natriuresis and greater susceptibility to progressive renal disease, impaired development of the endothelium, and increased sensitivity to glucocorticoids. Still, considerable work needs to be done to explain the birth weight/blood pressure relationship. The findings to date and the clinical significance warrant continued research in this intriguing area of study.

Effects of sewage-impacted sediment on reproduction in the benthic crustacean Leptocheirus plumulosus

Several organic contaminants in sewage effluent have been shown to elicit an estrogenic response in juvenile fish. Comparatively little emphasis has been placed on assessing these effects in marine invertebrates, particularly benthic organisms inhabiting sediment where lipophilic contaminants tend to persist. The present study examined reproductive effects in the benthic crustacean Leptocheirus plumulosus exposed to sewage-impacted sediment from Jamaica Bay, New York. Data from chronic 28-day tests showed a 50% reduction in the average number of young (juveniles + embryos) produced per surviving female in exposures to sediment from Jamaica Bay (JB). Nonylphenol ethoxylate ('NPEO) concentrations at this site were measured at 44.2 microg/g dw, concentrations two orders of magnitude higher than reference site concentrations in central Long Island Sound (CLIS). Dose-response studies with nonylphenol (NP) amended reference sediment, however, did not significantly affect reproduction suggesting that other contaminants may have contributed to the effects observed.

Analysis of nonylphenol and nonylphenol ethoxylates in environmental samples by mixed-mode high-performance liquid chromatography-electrospray mass spectrometry

A new method is described based on mixed-mode high-performance liquid chromatography with electrospray mass spectrometry detection for comprehensive quantitative analysis of nonylphenol (NP) and nonylphenol ethoxylates (NPEOs) in wastewater and sediment. Efficient separation, reduced band broadening, and high sensitivity were achieved by employing a methanol-water gradient on a mixed-solvent gel filtration column designed for MS interfacing. Quantitative accuracy and precision of the method were improved by the use of custom-synthesized [13C6]NPEO analogs as isotope-dilution surrogate standards. Method detection limits for NP and individual NPEOs ranged from I to 55 pg injected on column.

Determination of steroid estrogens in wastewater by immunoaffinity extraction coupled with HPLC-electrospray-MS

A new method, based on immunoaffinity extraction coupled with liquid chromatography/electrospray mass spectrometry (LC/ESI-MS) is described for the determination of the steroid estrogens beta-estradiol (E2), estrone (E1), and alpha-ethynylestradiol (E2) in wastewater. The use of highly selective immunosorbents in sample preparation prior to analysis allows the removal of interfering sample matrix compounds present in the wastewater extracts that would otherwise cause severe ionization suppression of the estrogens during the electrospray process. In addition, immunoextraction removes much of the isobaric noise from the selected ion monitoring chromatograms, increasing the signal-to-noise ratios for analytes, and contributing to the low detection limits (0.18 and 0.07 ng/L for E2 and E1, respectively) achieved by the current method. The method was applied to analysis of estrogens in two wastewater effluents. Recoveries of E2 and E1 were excellent (>90%), while the nonimmunogen (but structurally related) analyte EE2 was not retained (recovery <2%) from effluent extracts by the immunosorbent. This illustrates the extreme selectivity of the immunoextraction purification step. Precision of the method was high, with relative standard deviations below 5%. Concentrations of E2 in wastewater varied from 0.77 to 6.4 ng/L, while concentrations of E1 were greater (1.6-18 ng/L).

Distribution and fate of neutral alkylphenol ethoxylate metabolites in a sewage-impacted urban estuary

The distribution and fate of neutral metabolites of the alkylphenol ethoxylate (APEO) surfactants in an urbanized estuarine environment were examined utilizing a recently developed, highly sensitive LC-MS method. Results indicated that short ethoxyl-chain APEOs and alkylphenols (APs) were present in surficial sediments throughout the estuary at concentrations roughly correlated to the organic carbon content of the sediment and that the APEO mixture was dominated by nonylphenol ethoxylate (NPEOs) metabolites (0.05-30 microg/g), with lesser amounts of octylphenol ethoxylate metabolites (OPEOs)(<0.005-0.09 microg/ g) and halogenated nonylphenols (<0.001-0.03 microg/g). NPEO metabolites in surface water (0.22-1.05 microg/L) were also present at higher concentrations than OPEO metabolites (0.007-0.040 microg/L). APEO metabolite concentrations in both sediment and water showed a strong correlation with conventional sewage tracers, affirming a wastewater source of these contaminants. APEO distributions in surface waters within the estuary could be explained by a combination of post-discharge degradation and mixing with a seawater end-member enriched in OPEO metabolites. Measured in situ Koc values of APEO metabolites were comparable to previously reported values derived from field experiments but higher than Kow and Koc values derived from laboratory experiments. Results from the present work indicate that the fate of APEO metabolites entering the estuarine environment through discharge of wastewater is directed primarily by scavenging onto particles and subsequent burial in sediments, degradation during residence in the water column, and transport out of the estuary through advective and dispersive processes.

Analysis of alkylphenol ethoxylate metabolites in the aquatic environment using liquid chromatography-electrospray mass spectrometry

A quantitative method is described for the analysis of the metabolites of alkylphenol ethoxylate (APEO) surfactants in estuarine water and sediment samples using reversed-phase high-performance liquid chromatography with electrospray mass spectrometry detection. Nonyl- and octylphenols, nonyl- and octylphenol mono-, di-, and triethoxylates, halogenated nonylphenols, and nonylphenol ethoxycarboxylates were concentrated from water samples using a C18 solid-phase extraction procedure. A novel, continuous-flow, high-temperature, sonicated extraction system was developed to isolate APEO metabolites from sediment samples. Quantitative LC-MS was performed in the negative ion mode for nonylphenols, octylphenols, and halogenated nonylphenols and in the positive ion mode for nonyl- and octylphenol ethoxylates using selected ion monitoring with isotopically labeled surrogate standards. Recoveries for sediment and water analyses ranged between 78 and 94%, and detection limits for APEO metabolites were between 1 and 20 pg injected on column. This is a significant improvement over previously reported methods. Suppression of analyte response was encountered in the presence of matrix components in sediment samples, but this effect was eliminated by careful selection of surrogate and internal standards. Individual APEO metabolite concentrations of 1-320 ng/L and 5-2000 ng/g are reported for water and sediment samples, respectively, from Jamaica Bay, NY.

Pulse-chase analysis of the in vivo assembly of the bacteriophage T4 tail

The in vivo assembly pathway of the complex tail of bacteriophage T4 virus was determined using pulse-chase analysis as a non-invasive alternative to the in vitro experiments previously used to map assembly. Bacteriophage T4 mutants defective in head assembly were used to infect cultures of Escherichia coli in order to study tail assembly in isolation. Beginning with the onset of late protein synthesis, the cultures were labeled continuously with [(3)H]leucine to normalize against subsequent sample losses. After completed tails had begun to accumulate at a constant rate, the cultures were pulsed with [(35)S]methionine, and then chased. Completed tails were purified at one minute intervals for the next 30 minutes and their proteins separated electrophoretically and counted by liquid scintillation. Total (35)S incorporation into each protein rose and then leveled off as the chase of unlabeled methionine flushed the label through the pools of soluble proteins and assembly intermediates and into completed tails. The inflection point in the sigmoidal (35)S-incorporation curve of each protein marks the maximal uptake of (35)S within that pool just before the effect of the chase becomes apparent and the curve begins to level off. The length of the delay in the apparent chase time reflects the position of that protein in the pathway. The closer the assembly point to the end of the pathway, the sooner the chase appears, revealing the relative order of assembly. As predicted, tail completion proteins such as gp18 (tail sheath) and 19 (tail tube) show the earliest inflection, while those earlier in the pathway take longer to chase. Of the 17 tail proteins analyzed, 14 are in agreement with the established in vitro pathway. The other three, gp15, gp10 and gp53, have helped us to develop a model that offers a plausible explanation for their altered chase times.

Topological and functional analysis of the human reduced folate carrier by hemagglutinin epitope insertion

The membrane topology of the human reduced folate carrier protein (591 amino acids) was assessed by single insertions of the hemagglutinin epitope into nine sites of the protein. Reduced folate carrier-deficient Chinese hamster ovary cells expressing each of these constructs were probed with anti-hemagglutinin epitope monoclonal antibodies to assess whether the insertion was exposed to the external environment or to the cytoplasm. The results are consistent with the 12-transmembrane topology predicted for this protein. The hemagglutinin epitope insertion mutants were also tested for their effects on the function of the reduced folate carrier. For these studies, each of the constructs had a carboxyl-terminal fusion of the enhanced green fluorescent protein to monitor and quantitate expression. Insertions into the external loop between transmembrane regions 7 and 8 (Pro-297), the cytoplasmic loop between transmembrane regions 6 and 7 (Ser-225), and near the cytoplasmic amino and carboxyl termini (Pro-20 and Gly-492, respectively) had minor effects on methotrexate binding and uptake. The insertion into the cytoplasmic loop between transmembrane regions 10 and 11 (Gln-385) greatly reduced both binding and uptake of methotrexate, whereas the insertion into the external loop between transmembrane regions 11 and 12 (Pro-427) selectively interfered with uptake but not binding.

Capillary electrophoresis/laser-induced fluorescence detection of fluorescein as a groundwater migration tracer

Capillary electrophoresis (CE) has been applied to the determination of the groundwater migration tracer dye fluorescein based on laser-induced fluorescence (LIF) detection and compared to determinations obtained with traditional spectrofluorimetry. Detection limits of injected dye in the low parts per trillion (ppt) ranges have been accomplished with both CE/LIF based on the Ar ion laser and with a spectrofluorimeter. This approach was used for a real-world problem in determining groundwater migration between adjacent Resource Conservation and Recovery Act (RCRA) and Superfund sites by the Environmental Sciences Division in response to regional needs and as application of new analytical tools under development. Fluorescent dye was injected into source wells and then was determined in monitoring wells by extracting pads that adsorbed the dye or by directly determining the dye in the water using solid-phase extraction (SPE), a preconcentration technique. The approaches based on CE/LIF exhibits increased specificity over existing approaches due to the separation and unique migration time of the dye. Additional studies were aimed at achieving sub-ppt levels in the water using solid-phase extraction and field-amplified injection techniques.

Development of separation systems for polynuclear aromatic hydrocarbon environmental contaminants using micellar electrokinetic chromatography with molecular micelles and free zone electrophoresis

Of four systems available from the literature, based on cyclodextrins, dioctylsulfosuccinate, bile salts, and molecular micelles consisting of oligomers of undecylenic acid, the most successful separation system in our hands is based on the molecular micelles, oligomers of sodium undecylenic acid (OSUA). We have employed organic additives of acetonitrile, acetone, and tetrahydrofuran in achieving separations of polyaromatic hydrocarbons (PNAs) using molecular micelles. Generally, successful separations are achieved with 20-40% composition as the organic additive in an 8 mM borate buffer. We separated 16 PNAs with 20% tetrahydrofuran in a system of 8 mM borate and 0.125 g/10 mL (ca. 6.25 mM) of OSUA. Typical extracts of environmental samples contain additional analytes besides the typical 16 target compounds. Among these are the nitrogen-containing aromatics that can act as cations under conditions of low pH and additional compounds that can act as anions under basic conditions in free-zone electrophoresis. These additional classes of analytes are separated by capillary zone electrophoresis/laser-induced fluorescence detection using a frequency-doubled laser operated at 257 nm.

Identification of bacteriophage T4 virion proteins by transverse pore-gradient sodium dodecyl sulfate-polyacrylamide gel electrophoresis and dual amino acid labeling

We have developed a horizontal N,N'-methylenebisacrylamide (Bis) acrylamide gradient sodium dodecyl sulfate (SDS) gel system that permits the evaluation of the purity of individual protein bands in complex mixtures. A Bis gradient gel is poured vertically and, after polymerization, reoriented horizontally. A single large sample spanning the top of the gel is then run down at right angles to the gradient. The relative mobility of a few proteins varies considerably from the rest, causing them to merge with and cross other bands as the Bis concentration changes. Band splitting revealed that several bands previously thought to represent a single species are actually comprised of comigrating proteins. Once the Bis/monomer concentration offering the best separation was identified, we sought a simple method for identifying the genetic origin of bands, since many proteins now migrated in new positions on the gel. We reasoned that if infected cells were simultaneously labeled with [35S]methionine and [3H]leucine and the purified virion proteins analyzed to determine their 35S/3H ratio, we could identify most proteins by comparing this ratio with one calculated from the T4 DNA sequence. Our expectations were realized, and we here report the separation and identification of all T4 virion proteins. Finally, we comment on the incorporation of various changes to the original Laemmli SDS-polyacrylamide gel formulations that have been reported in the literature.

Applications of capillary electrophoresis/laser-induced fluorescence detection to groundwater migration studies

Capillary electrophoresis has been applied to the determination of groundwater migration based on laser-induced fluorescence (LIF) detection and traditional spectrofluorimetry. Detection limits of injected dye-fluorescent whitening agent (tinopal) in the low ppt ranges have been accomplished with both a spectrofluorometer and with CE/LIF based on the HeCd laser. The real-world problem was the determination of groundwater migration between adjacent Resource Conservation and Recovery Act (RCRA) and Superfund sites. Fluorescent dyes were injected into wells and were discovered in monitoring wells by extracting pads that adsorbed the dye. The methodology based on CE/LIF exhibits increased specificity over existing methodology due to the separation and unique migration time of the dye. Additional studies were aimed at achieving sub-ppt levels in the water directly using solid-phase extraction (SPE) and field-amplified injection techniques.