Comparative effectiveness and complications of intravenous ceftriaxone compared with oral doxycycline in Lyme meningitis in children: a multicentre prospective cohort study

INTRODUCTION

Lyme disease is the most common vectorborne disease in the Northern hemisphere with more than 400 000 new cases in the USA annually. Lyme meningitis is an uncommon but potentially serious clinical manifestation of Lyme disease. Intravenous ceftriaxone had been the first-line treatment for Lyme meningitis, but is associated with a high rate of complications. Although efficacy and effectiveness (or real-world evidence) data for oral doxycycline are limited, practice guidelines were recently expanded to recommend either oral doxycycline or ceftriaxone as first-line treatments for Lyme meningitis. Our goal is to compare oral doxycycline with intravenous ceftriaxone for the treatment of Lyme meningitis on short-term recovery and long-term quality of life.

METHODS AND ANALYSIS

We are performing a prospective cohort study at 20 US paediatric centres located in diverse geographical range where Lyme disease is endemic. The clinical care team will make all antibiotic treatment decisions for children with Lyme meningitis, as per usual practice. We will follow enrolled children for 6 months to determine time of acute symptom recovery and impact on quality of life.

ETHICS AND DISSEMINATION

Boston Children's Hospital, the single Institutional Review Board (sIRB), has approved the study protocol with the other 19 enrolling sites as well as the Utah data coordinating centre relying on the Boston Children's Hospital sIRB. Once the study is completed, we will publish our findings in a peer-reviewed medical journal.

Emergency Department Child Abuse Evaluations During COVID-19: A Multicenter Study

BACKGROUND AND OBJECTIVE

The reported impacts of the COVID-19 pandemic on child maltreatment in the United States have been mixed. Encounter trends for child physical abuse within pediatric emergency departments may provide insights. Thus, this study sought to determine the change in the rate of emergency department encounters related to child physical abuse.

METHODS

A retrospective study within the Pediatric Emergency Care Applied Research Network Registry. Encounters related to child physical abuse were identified by 3 methods: child physical abuse diagnoses among all ages, age-restricted high-risk injury, or age-restricted skeletal survey completion. The primary outcomes were encounter rates per day and clinical severity before (January 2018-March 2020) and during the COVID-19 pandemic (April 2020-March 2021). Multivariable Poisson regression models were fit to estimate rate ratios with marginal estimation methods.

RESULTS

Encounter rates decreased significantly during the pandemic for 2 of 3 identification methods. In fully adjusted models, encounter rates were reduced by 19% in the diagnosis-code cohort (adjusted rate ratio: 0.81 [99% confidence interval: 0.75-0.88], P <.001), with the greatest reduction among preschool and school-aged children. Encounter rates decreased 10% in the injury cohort (adjusted rate ratio: 0.90 [confidence interval: 0.82-0.98], P = .002). For all 3 methods, rates for lower-severity encounters were significantly reduced whereas higher-severity encounters were not.

CONCLUSIONS

Encounter rates for child physical abuse were reduced or unchanged. Reductions were greatest for lower-severity encounters and preschool and school-aged children. This pattern calls for critical assessment to clarify whether pandemic changes led to true reductions versus decreased recognition of child physical abuse.

Association of Physical Activity, Sports, and Screen Time With Adolescent Behaviors in Youth Who Visit the Pediatric Emergency Department

Moderate to vigorous physical activity (MVPA), sports, and reduced screen time are associated with favorable youth risk profiles. We evaluated the association of MVPA, sports, and screen time with adolescent behaviors among pediatric emergency department youth. Adolescents were assessed for alcohol/drug use, risky behavior, conduct disorder, and depressive mood. MVPA was activity for ≥5 days/week and ≥60 minutes/day. Increased screen time was ≥3 hours/day computer/TV use for non-schoolwork. Multivariable regression studied association between MVPA, sports, and increased screen time and outcomes adjusting for demographics and academic achievement. Older age and lower academic achievement were significantly associated with risky behaviors, conduct disorder, and depression. Youth who endorsed MVPA and sports participation had less depression (odds ratio [OR] = 0.76; confidence interval [CI] = 0.66-0.87). Increased screen time was associated with conduct disorder (OR = 1.6; CI = 1.3-2.1), depression (OR = 1.2; CI = 1.0-1.4), and drug use (OR = 1.8; CI = 1.1-2.8). In pediatric emergency department youth, MVPA and sports participation is associated with less depression. Increased screen time is associated with conduct disorders, depression, and drug use.

Lack of Association of Household Income and Acute Gastroenteritis Disease Severity in Young Children: A Cohort Study

OBJECTIVE

To determine if low household income is associated with disease severity following emergency department (ED) discharge in children with acute gastroenteritis (AGE).

METHODS

We conducted a secondary analysis employing data collected in 10 US-based tertiary-care, pediatric EDs between 2014 and 2017. Participants were aged 3 to 48 months and presented for care due to AGE. Income status was defined based on 1) home ZIP Code median annual home income and 2) percentage of home ZIP Code households below the poverty threshold. The primary outcome was moderate-to-severe AGE, defined by a post-ED visit Modified Vesikari Scale (MVS) score ≥9. Secondary outcomes included in-person revisits, revisits with intravenous rehydration, hospitalization, and etiologic pathogens.

RESULTS

About 943 (97%) participants with a median age of 17 months (interquartile range 10, 28) completed follow-up. Post-ED visit MVS scores were lower for the lowest household income group (adjusted: -0.60; 95% confidence interval [CI]: -1.13, -0.07). Odds of experiencing an MVS score ≥9 did not differ between groups (adjusted odds ratio: 0.91; 95% CI: 0.54, 1.52). No difference in the post-ED visit MVS score or the proportion of participants with scores ≥9 was observed using the national poverty threshold definition. For both income definitions, there were no differences in terms of revisits following discharge, hospitalizations, and intravenous rehydration. Bacterial enteropathogens were more commonly identified in the lowest socioeconomic group using both definitions.

CONCLUSIONS

Lower household income was not associated with increased disease severity or resource use. Economic disparities do not appear to result in differences in the disease course of children with AGE seeking ED care.

Prospective Validation of a Rapid Host Gene Expression Test to Discriminate Bacterial From Viral Respiratory Infection

Importance

Bacterial and viral causes of acute respiratory illness (ARI) are difficult to clinically distinguish, resulting in the inappropriate use of antibacterial therapy. The use of a host gene expression-based test that is able to discriminate bacterial from viral infection in less than 1 hour may improve care and antimicrobial stewardship.

Objective

To validate the host response bacterial/viral (HR-B/V) test and assess its ability to accurately differentiate bacterial from viral infection among patients with ARI.

Design, Setting, and Participants

This prospective multicenter diagnostic study enrolled 755 children and adults with febrile ARI of 7 or fewer days' duration from 10 US emergency departments. Participants were enrolled from October 3, 2014, to September 1, 2019, followed by additional enrollment of patients with COVID-19 from March 20 to December 3, 2020. Clinical adjudication of enrolled participants identified 616 individuals as having bacterial or viral infection. The primary analysis cohort included 334 participants with high-confidence reference adjudications (based on adjudicator concordance and the presence of an identified pathogen confirmed by microbiological testing). A secondary analysis of the entire cohort of 616 participants included cases with low-confidence reference adjudications (based on adjudicator discordance or the absence of an identified pathogen in microbiological testing). Thirty-three participants with COVID-19 were included post hoc.

Interventions

The HR-B/V test quantified the expression of 45 host messenger RNAs in approximately 45 minutes to derive a probability of bacterial infection.

Main Outcomes and Measures

Performance characteristics for the HR-B/V test compared with clinical adjudication were reported as either bacterial or viral infection or categorized into 4 likelihood groups (viral very likely [probability score <0.19], viral likely [probability score of 0.19-0.40], bacterial likely [probability score of 0.41-0.73], and bacterial very likely [probability score >0.73]) and compared with procalcitonin measurement.

Results

Among 755 enrolled participants, the median age was 26 years (IQR, 16-52 years); 360 participants (47.7%) were female, and 395 (52.3%) were male. A total of 13 participants (1.7%) were American Indian, 13 (1.7%) were Asian, 368 (48.7%) were Black, 131 (17.4%) were Hispanic, 3 (0.4%) were Native Hawaiian or Pacific Islander, 297 (39.3%) were White, and 60 (7.9%) were of unspecified race and/or ethnicity. In the primary analysis involving 334 participants, the HR-B/V test had sensitivity of 89.8% (95% CI, 77.8%-96.2%), specificity of 82.1% (95% CI, 77.4%-86.6%), and a negative predictive value (NPV) of 97.9% (95% CI, 95.3%-99.1%) for bacterial infection. In comparison, the sensitivity of procalcitonin measurement was 28.6% (95% CI, 16.2%-40.9%; P < .001), the specificity was 87.0% (95% CI, 82.7%-90.7%; P = .006), and the NPV was 87.6% (95% CI, 85.5%-89.5%; P < .001). When stratified into likelihood groups, the HR-B/V test had an NPV of 98.9% (95% CI, 96.1%-100%) for bacterial infection in the viral very likely group and a positive predictive value of 63.4% (95% CI, 47.2%-77.9%) for bacterial infection in the bacterial very likely group. The HR-B/V test correctly identified 30 of 33 participants (90.9%) with acute COVID-19 as having a viral infection.

Conclusions and Relevance

In this study, the HR-B/V test accurately discriminated bacterial from viral infection among patients with febrile ARI and was superior to procalcitonin measurement. The findings suggest that an accurate point-of-need host response test with high NPV may offer an opportunity to improve antibiotic stewardship and patient outcomes.

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.

Adolescent Substance Abuse Risk: A Comparison of Pediatric Emergency Care Applied Research Network Emergency Department Patients and 2 Nationally Representative Samples

OBJECTIVES

The aim of this study was to understand the prevalence of alcohol and other substance use among teenagers in generalized samples.

METHODS

This study compared the alcohol and other substance use of adolescents enrolled in a screening study across 16 Pediatric Emergency Care Applied Research Network emergency departments (EDs) (ASSESS) with those sampled in 2 nationally representative surveys, the Youth Risk Behavior Surveillance System (YRBSS) and the National Survey of Drug Use and Health (NSDUH). The analysis includes 3362 ASSESS participants and 11,142 YRBSS and 12,086 NSDUH respondents.

RESULTS

The ASSESS patients had a similar profile to the NSDUH sample, with small differences in marijuana and cocaine use and age at first tobacco smoking and smoking within the last 30 days and higher use of snuff or chewing tobacco. The YRBSS participants had higher rates of using marijuana, snuff/chewing tobacco, methamphetamine, and hallucinogens and higher smoking rates compared with ASSESS and NSDUH.

CONCLUSIONS

Adolescents visiting Pediatric Emergency Care Applied Research Network EDs have substantial rates of substance use, similar to other nationally representative studies on this topic, although not as high as a school-based survey. Future ED studies should continue to investigate adolescent substance use, including exploring optimal methods of survey administration.

Factors Associated With Nonadherence in an Emergency Department-based Multicenter Randomized Clinical Trial of a Probiotic in Children With Acute Gastroenteritis

ABSTRACT

Nonadherence in clinical trials affects safety and efficacy determinations. Predictors of nonadherence in pediatric acute illness trials are unknown. We sought to examine predictors of nonadherence in a multicenter randomized trial of 971 children with acute gastroenteritis receiving a 5-day oral course of Lactobacillus rhamnosus GG or placebo. Adherence, defined as consuming all doses of the product, was reported by the parents and recorded during daily follow-up contacts. Of 943 patients with follow-up data, 766 (81.2%) were adherent. On multivariate analysis, older age (OR 1.19; 95% CI: 1.00-1.43), increased vomiting duration (OR 1.23; 95% CI: 1.05-1.45), higher dehydration score (OR 1.23, 95% CI: 1.07-1.42), and hospitalization following ED discharge (OR 4.16, 95% CI: 1.21--14.30) were factors associated with nonadherence; however, those with highest severity scores were more likely to adhere (OR 0.87, 95% CI: 0.80-0.95). These data may inform strategies and specific targets to maximize adherence in future pediatric trials.

IDeA States Pediatric Clinical Trials Network for Underserved and Rural Communities

The National Institutes of Health's Environmental Influences on Child Health Outcomes (ECHO) program aims to study high-priority and high-impact pediatric conditions. This broad-based health initiative is unique in the National Institutes of Health research portfolio and involves 2 research components: (1) a large group of established centers with pediatric cohorts combining data to support longitudinal studies (ECHO cohorts) and (2) pediatric trials program for institutions within Institutional Development Awards states, known as the ECHO Institutional Development Awards States Pediatric Clinical Trials Network (ISPCTN). In the current presentation, we provide a broad overview of the ISPCTN and, particularly, its importance in enhancing clinical trials capabilities of pediatrician scientists through the support of research infrastructure, while at the same time implementing clinical trials that inform future health care for children. The ISPCTN research mission is aligned with the health priority conditions emphasized in the ECHO program, with a commitment to bringing state-of-the-science trials to children residing in underserved and rural communities. ISPCTN site infrastructure is critical to successful trial implementation and includes research training for pediatric faculty and coordinators. Network sites exist in settings that have historically had limited National Institutes of Health funding success and lacked pediatric research infrastructure, with the initial funding directed to considerable efforts in professional development, implementation of regulatory procedures, and engagement of communities and families. The Network has made considerable headway with these objectives, opening two large research studies during its initial 18 months as well as producing findings that serve as markers of success that will optimize sustainability.

Effects of Alcohol Cue Reactivity on Subsequent Treatment Outcomes Among Treatment-Seeking Individuals with Alcohol Use Disorder: A Multisite Randomized, Double-Blind, Placebo-Controlled Clinical Trial of Varenicline

BACKGROUND

The alcohol cue reactivity paradigm is increasingly used to screen medications for the treatment of alcohol use disorder (AUD) and other substance use disorders. Yet, its prospective association with craving and naturalistic drinking outcomes in clinical trials remains unknown. This study embedded repeated human laboratory assessments of alcohol cue reactivity within the context of a randomized controlled trial to examine the effects of varenicline tartrate (Chantix^® ), a partial agonist of α4β2 nicotinic acetylcholine receptors, on alcohol craving among treatment-seeking heavy drinkers with AUD. Our main objectives were to test whether varenicline, as compared to placebo, blunts alcohol cue-elicited craving and test whether alcohol cue reactivity observed in the human laboratory predicts subsequent alcohol craving and use during the remainder of the trial.

DESIGN AND METHODS

This double-blind, randomized, 2-site study compared the effects of varenicline (up to 2 mg/d) and placebo on responses to in vivo alcohol cue and affective picture cue exposure in the human laboratory. Forty-seven volunteers (18 females, 29 males), ages 23 to 67 years (M = 43.7, SD = 11.5), were recruited from the community via advertisements to participate in a clinical trial designed to study the effects of varenicline on alcohol use. Participants were randomized to either varenicline or placebo for 6 weeks.

RESULTS

Varenicline did not attenuate cue-induced alcohol craving relative to placebo, but craving captured during the cue reactivity paradigm significantly predicted subsequent alcohol use in real-world settings during the clinical trial. Higher craving predicted heavier alcohol use.

CONCLUSIONS

Our results are among the first to show alcohol cue-induced craving captured during a human laboratory paradigm predicts drinking outcomes in the context of a clinical trial.

Sex Without Contraceptives in a Multicenter Study of Adolescent Emergency Department Patients

OBJECTIVES

In the United States, rates of teenage pregnancy and sexually transmitted infections (STIs) remain exceptionally high, and racial and ethnic disparities persist. Emergency departments (EDs) care for over 19 million adolescents each year, the majority being minority and low socioeconomic status. Single-center studies demonstrate infrequent use of contraceptives among adolescent ED patients and an association between risky sex and behaviors such as alcohol and drug use; however, no multicenter ED data exist. The objectives of this study were to 1) determine the prevalence of sex without contraceptives in a large multicenter adolescent ED study and 2) assess patient demographic and risky behaviors associated with sex without contraceptives.

METHODS

Participants aged 14 to 17 years (n = 3,247) in 16 pediatric EDs across the United States completed an electronic survey. Questions focused on validated measures of risky sex; use of alcohol, tobacco, marijuana, and other drugs; and depression and violence. In this secondary analysis, we constructed univariable and multivariable models to identify demographic and behavioral factors associated with sex without contraceptives (our primary outcome), separately for adolescent males and females.

RESULTS

In the prior year, 17.4% (236/1,356) of males and 15.8% (299/1,891) of females had sex without contraceptives. In the multivariable model, sex without contraceptives for both genders was more likely among teens who were black, with conduct problems and participated in casual sex, binge drinking, or cannabis use. Sex without contraceptives was also more likely among Hispanic and cigarette-smoking males, as well as depressed females.

CONCLUSIONS

Adolescent ED patients across the United States are participating in risky sexual behaviors that increase their likelihood of pregnancy and STI acquisition. These adolescents report a number of problem behaviors, including substance use, which are strongly correlated with unprotected sex. The ED visit may be an opportunity to identify at-risk adolescent patients, address risky behaviors, and intervene to improve adolescent health.

Reliability of the Clinical SBIRT Proficiency Checklist for Medical Students

INTRODUCTION

The Substance Abuse and Mental Health Services Agency (SAMHSA) recognizes Screening, Brief Intervention, and Referral to Treatment (SBIRT) as a comprehensive approach to identify individuals with or at risk of developing substance use disorders. Few studies have explored tools for assessing medical student SBIRT competencies.

METHODS

First-year medical students trained in SBIRT and Motivational Interviewing completed an Objective Structured Clinical Encounter (OSCE) with a standardized patient who presented with substance use. Six trained members of our research team reviewed 118 OSCE videos utilizing the Clinical SBIRT Proficiency Checklist (CSPC); additionally 30% (n = 37) were randomly selected for pair-review to examine interrater reliability.

RESULTS

Interrater reliability was Cohen's kappa of 0.89 for the presence of SBIRT skills and 0.39 agreement for the absence of skills. Across the videos, the most commonly observed skill was screening for alcohol use (75.4%, 95%CI 66.5, 84.3), while organizing referral for treatment was infrequently observed (36.4%, 95% CI 22.0, 50.8).

CONCLUSIONS

The CSPC is a reliable tool for assessing medical student SBIRT skills on an OSCE. These findings provide insights on medical student SBIRT knowledge and provides a practical tool for providing early clinically relevant feedback on these skills.

Predictive Validity of the CRAFFT for Substance Use Disorder

BACKGROUND

The utility of CRAFFT (Car, Relax, Alone, Forget, Friends, Trouble) in identifying current and future problematic substance use and substance use disorders (SUDs) in pediatric emergency department (PED) patients is unknown. We conducted a secondary analysis of a study in 16 PEDs to determine the concurrent and predictive validity of CRAFFT with respect to SUD.

METHODS

At baseline, 4753 participants aged 12 to 17 years completed an assessment battery (CRAFFT and other measures of alcohol, drug use, and risk behaviors). A subsample was readministered the battery at 1-, 2-, and 3-year follow-up to investigate future SUDs.

RESULTS

Of 2175 participants assigned to follow-up, 1493 (68.6%) completed 1-year, 1451 (66.7%) completed 2-year, and 1265 (58.1%) completed the 3-year follow-up. A baseline CRAFFT value of ≥2 was significantly associated with problematic substance use or mild or moderate to severe SUD diagnosis on the Diagnostic Interview Schedule for Children at baseline (P < .001). The results persisted after 1, 2, and 3 years (P < .001). The best combined sensitivity and specificity was achieved with a baseline CRAFFT value of ≥1 as a cutoff for predicting problematic substance use and a Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition diagnosis of mild SUD at 1, 2, and 3 years. The baseline CRAFFT score that best predicted a moderate to severe SUD at 1 year was ≥2; but at 2 and 3 years, the cutoff score was ≥1.

CONCLUSIONS

CRAFFT has good concurrent validity for problematic substance use and SUD in PED patients and is useful in predicting SUDs at up to 3 years follow-up but with limited sensitivity.

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.

Substance use screening, brief intervention, and referral to treatment training for emergency medicine trainees

INTRODUCTION

Emergency medicine (EM) providers are in an opportunistic position to identify and intervene with patients at risk for alcohol misuse and related problems. However, alcohol screening, brief intervention, and referral to treatment (SBIRT) services are underutilized within the emergency department. Providing SBIRT training to trainees may help to increase utilization of these valuable services in the future. An SBIRT training program for EM faculty and trainees was developed and delivered to increase trainees' skills and practice of SBIRT services.

METHODS

The SBIRT training program included unique tracks for medical students, physician assistant (PA) students, EM residents and faculty preceptors. Faculty and trainees completed performance measures at the end of each training session, 30 days post-training and 12 months later.

RESULTS

SBIRT training was provided to 238 trainees and 65 faculty members. At all follow-up time points, satisfaction of training and usefulness varied by trainee type with PA students rating constructs higher than both medical students and EM residents. At the 12-month follow-up survey, there was no significant difference in ratings of sharing the information (χ² (2)=0.38, P=0.33) between these trainees, with the majority of all trainees (96% of PA students, 83% of residents and 68% of medical students) responding that they had applied what they learned in the training to their work.

CONCLUSION

An SBIRT training curriculum for EM trainees was delivered successfully and utilized 12 months after implementation.

Randomised controlled trial of Lactobacillus rhamnosus (LGG) versus placebo in children presenting to the emergency department with acute gastroenteritis: the PECARN probiotic study protocol

INTRODUCTION

Acute gastroenteritis (AGE) is a common and burdensome condition that affects millions of children worldwide each year. Currently available strategies are limited to symptomatic management, treatment and prevention of dehydration and infection control; no disease-modifying interventions exist. Probiotics, defined as live microorganisms beneficial to the host, have shown promise in improving AGE outcomes, but existing studies have sufficient limitations such that the use of probiotics cannot currently be recommended with confidence. Here we present the methods of a large, rigorous, randomised, double-blind placebo-controlled study to assess the effectiveness and side effect profile of Lactobacillus rhamnosus GG (LGG) (ATCC 53103) in children with AGE.

METHODS AND ANALYSIS

The study is being conducted in 10 US paediatric emergency departments (EDs) within the federally funded Pediatric Emergency Care Applied Research Network, in accordance with current SPIRIT and CONSORT statement recommendations. We will randomise 970 children presenting to participating EDs with AGE to either 5 days of treatment with LGG (10¹⁰colony-forming unit twice a day) or placebo between July 2014 to December 2017. The main outcome is the occurrence of moderate-to-severe disease over time, as defined by the Modified Vesikari Scale. We also record adverse events and side effects related to the intervention. We will conduct intention-to-treat analyses and use an enrichment design to restore the statistical power in case the presence of a subpopulation with a substantially low treatment effect is identified.

ETHICS AND DISSEMINATION

Institutional review board approval has been obtained at all sites, and data and material use agreements have been established between the participating sites. The results of the trial will be published in peer-reviewed journals. A deidentified public data set will be made available after the completion of all study procedures.

TRIAL REGISTRATION NUMBER

NCT01773967.

Nonemergency Acute Care: When It's Not the Medical Home

The American Academy of Pediatrics (AAP) affirms that the optimal location for children to receive care for acute, nonemergency health concerns is the medical home. The medical home is characterized by the AAP as a care model that "must be accessible, family centered, continuous, comprehensive, coordinated, compassionate, and culturally effective." However, some children and families use acute care services outside the medical home because there is a perceived or real benefit related to accessibility, convenience, or cost of care. Examples of such acute care entities include urgent care facilities, retail-based clinics, and commercial telemedicine services. Children deserve high-quality, appropriate, and safe acute care services wherever they access the health care system, with timely and complete communication with the medical home, to ensure coordinated and continuous care. Treatment of children under established, new, and evolving practice arrangements in acute care entities should adhere to the core principles of continuity of care and communication, best practices within a defined scope of services, pediatric-trained staff, safe transitions of care, and continuous improvement. In support of the medical home, the AAP urges stakeholders, including payers, to avoid any incentives (eg, reduced copays) that encourage visits to external entities for acute issues as a preference over the medical home.

Reliability and Validity of a Two-Question Alcohol Screen in the Pediatric Emergency Department

BACKGROUND AND OBJECTIVE

A multisite study was conducted to determine the psychometric properties of the National Institute of Alcohol Abuse and Alcoholism (NIAAA) 2-question alcohol screen within pediatric emergency departments (PEDs).

METHODS

Participants (N = 4838) included 12- to 17-year-old subjects treated in 1 of the 16 participating PEDs across the United States. A criterion assessment battery (including the NIAAA 2-question alcohol screen and other measures of alcohol, drug use, and risk behaviors) was self-administered on a tablet computer. A subsample (n = 186) was re-administered the NIAAA 2-question screen 1 week later to assess test-retest reliability.

RESULTS

Moderate to good test-retest reliability was demonstrated. A classification of moderate risk or higher on the screen had the best combined sensitivity and specificity for determining a diagnosis of alcohol use disorder (AUD) for all students. Any past year drinking among middle school students increased the odds of a diagnosis of an AUD according to Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition criteria, whereas the optimal cutoff for high school ages was ≥3 drinking days in the past year. The optimal cutoff for drinking days determining a positive Alcohol Use Disorders Identification Test score among middle school subjects was ≥1 drinking day, whereas the optimal cutoff for high school subjects was ≥2 drinking days.

CONCLUSIONS

The NIAAA 2-question screen is a brief, valid approach for alcohol screening in PEDs. A positive screen suggests that referral for further evaluation is indicated to determine if an adolescent has an AUD.

Patient-centered outcomes research in appendicitis in children: Bridging the knowledge gap

PURPOSE

Patient-centered outcomes research (PCOR) aims to give patients a better understanding of the treatment options to enable optimal decision-making. As nonoperative alternatives are now being evaluated in children for acute appendicitis, we surveyed patients and their families regarding their knowledge of appendicitis and evaluated whether providing basic medical information would affect their perception of the disease and allow them to more rationally consider the treatment alternatives.

METHODS

Families of children aged 5-18 presenting to the Emergency Department with suspected appendicitis were recruited for a tablet-based interactive educational survey. One hundred subjects (caregivers and patients ≥ 15 years) were questioned before and after an education session about their understanding of appendicitis, including questions on three hypothetical treatment options: urgent appendectomy, antibiotics alone, or initial antibiotics followed by elective appendectomy. Subjects were clearly informed that urgent appendectomy is currently the standard of care.

RESULTS

Only 14% of respondents correctly identified the mortality rate of appendicitis (17 deaths/year according to the 2010 US census) when compared with other extremely rare causes of death. Fifty-four and 31% thought it was more common than death from lightning (40/year) and hunting-associated deaths (44/year), respectively. Eighty-two percent of respondents believed it "likely" or "very likely" that the appendix would rupture if operation was at all delayed, and 81% believed that rupture of the appendix would rapidly lead to severe complications and death. In univariate analysis, this perception was significantly more prevalent for mothers (odds ratio, (OR) 5.19, confidence interval (CI) 1.33-21.15), and subjects who knew at least one friend or relative who had a negative experience with appendicitis (OR 5.53, CI 1.40-25.47). Following education, these perceptions changed significantly (53% still believed that immediate operation was necessary, and 47% believed perforation led to great morbidity and potential mortality, P<0.001). In a survey of potential appendicitis treatment options, urgent appendectomy was considered a "good" or "very good" option by 74% of subjects, compared with 68% for antibiotics only without appendectomy and 49% for initial antibiotic therapy followed by elective outpatient appendectomy.

CONCLUSION

There was a striking knowledge gap in the participant perception of appendicitis. Appropriate education can correct anecdotally supported misconceptions. Adequate education may empower patients to make better-informed decisions about their medical care and may be important for future studies in alternative treatments for appendicitis in children.

Substance Use and Depressive Symptoms among Adolescents Treated in a Pediatric Emergency Department

The current study examined associations between substance use and depressed mood by gender and type of substance used (no use, alcohol, marijuana or both alcohol and marijuana) in a sample of 713 adolescents (M_age = 15.3) recruited from a Pediatric Emergency Department (PED). Adolescents who reported any marijuana use had higher overall depressed mood scores compared to all other adolescents. When examined by gender, females with both alcohol and marijuana use reported the highest overall depressed mood symptoms. These results suggest the usefulness of screening and identification of depressive symptoms among adolescents presenting to a PED for substance use-related problems.

Challenges of managing pediatric mental health crises in the emergency department

Children with mental health problems are increasingly being evaluated and treated in pediatric clinical settings. This article focuses on the epidemiology, evaluation, and management of the 2 most common pediatric mental health emergencies, suicidal and homicidal/aggressive patients, as well as the equally challenging population of children with autism or other developmental disabilities.

Multicenter pediatric emergency medicine research and Rhode Island

Multicenter clinical research studies are often needed to address issues of generalizability, conditions with low incidence, adequate statistical power, and potential study bias. While pediatric research networks began work in the 1950s, and Rhode Island physicians have contributed to many of these studies, pediatric emergency medicine (PEM) collaboratives are relative newcomers. Since the mid-1990s, Rhode Island pediatricians have contributed to multicenter studies of diabetic ketoacidosis, bronchiolitis, asthma, quality of PEM care, meningitis, brief interventions for substance use disorders, point-of-care ultrasound, and pre-hospital triage protocols. In 2011, Rhode Island Hospital joined the Pediatric Emergency Care Applied Research Network, the first federally funded pediatric emergency medicine network of its kind. Its mission is to perform high quality, high impact PEM research. Since joining the network, Rhode Island Hospital has quickly become a productive and valued member of the network, portending a bright future for multicenter PEM research in the Ocean State.

Pediatric mental health emergencies and special health care needs

Children with mental health problems are increasingly being evaluated and treated by both pediatric primary care and pediatric emergency physicians. This article focuses on the epidemiology, evaluation, and management of the 2 most common pediatric mental health emergencies, suicidal and homicidal/aggressive patients, as well as the equally challenging population of children with autism or other developmental disabilities.

Emergency Department Screening for Adolescent Mental Health Disorders: The Who, What, When, Where, Why and How It Could and Should Be Done

Mental health problems are a significant cause of morbidity and mortality among pediatric populations. Screening for these problems can result in earlier identification and increase treatment and improve outcomes for these children and adolescents. The emergency department (ED) is an ideal site for such screening. Pediatric ED patients are known to be at higher risk for mental health problems. For many, an ED visit is one of the few opportunities to identify and intervene with these children and adolescents. A number of brief, efficient screening instruments have been developed for the ED setting. Screening for mental health problems is both feasible and acceptable to ED patients, parents, and caregivers.

Pediatric observation units

Pediatric observation units (OUs) are hospital areas used to provide medical evaluation and/or management for health-related conditions in children, typically for a well-defined, brief period. Pediatric OUs represent an emerging alternative site of care for selected groups of children who historically may have received their treatment in an ambulatory setting, emergency department, or hospital-based inpatient unit. This clinical report provides an overview of pediatric OUs, including the definitions and operating characteristics of different types of OUs, quality considerations and coding for observation services, and the effect of OUs on inpatient hospital utilization.

Dispensing medications at the hospital upon discharge from an emergency department

Although most health care services can and should be provided by their medical home, children will be referred or require visits to the emergency department (ED) for emergent clinical conditions or injuries. Continuation of medical care after discharge from an ED is dependent on parents or caregivers' understanding of and compliance with follow-up instructions and on adherence to medication recommendations. ED visits often occur at times when the majority of pharmacies are not open and caregivers are concerned with getting their ill or injured child directly home. Approximately one-third of patients fail to obtain priority medications from a pharmacy after discharge from an ED. The option of judiciously dispensing ED discharge medications from the ED's outpatient pharmacy within the facility is a major convenience that overcomes this obstacle, improving the likelihood of medication adherence. Emergency care encounters should be routinely followed up with primary care provider medical homes to ensure complete and comprehensive care.

Beliefs and practices of pediatric emergency physicians and nurses regarding counseling alcohol-using adolescents: can counseling practice be predicted?

OBJECTIVES

The objectives of the study were to investigate the attitudes and practices of pediatric emergency department (PED) physicians (MDs), MD extenders (MD's assistants [PAs], nurse practitioners [NPs]), and nurses (RNs) regarding their counseling of alcohol-using adolescent PED patients and to determine which, if any, PED clinician characteristics predict current counseling practice.

METHODS

An Internet-based survey of PED clinicians (MDs, PAs, NPs, and RNs) from 11 academic US PEDs was conducted. Respondents were asked about their counseling training, current counseling practices, confidence in their counseling skills, importance of counseling, attitudes and beliefs about counseling, and demographic information. Univariate and multivariate analyses were performed to determine the relationship between clinician characteristics and counseling practice.

RESULTS

Counseling practice was strongly associated with one's profession; PED MDs/PAs/NPs reported significantly higher rates of counseling alcohol-using adolescents than PED RNs. These 2 groups differed significantly in terms of counseling training and experience. Counseling training and experience remained significant predictors of counseling practice, even after controlling for profession and other covariates. Both groups had similar views on the importance of counseling, confidence in their ability to counsel, and counseling substance-using adolescent PED patients.

CONCLUSIONS

Pediatric ED MDs/PAs/NPs differ significantly from PED RNs in their counseling training, experience, and practice. These findings have important implications for the training and support necessary to successfully implement PED counseling. Specifically, formal training in counseling during professional schooling and garnering counseling experience after completing training may be critical factors in promoting PED counseling.

Ethnic group differences in substance use, depression, peer relationships, and parenting among adolescents receiving brief alcohol counseling

This study examined differences in substance use and related risk factors in a matched sample of Hispanic and White non-Hispanic adolescents receiving brief alcohol counseling. Findings revealed that the White non-Hispanic adolescents reported smoking a higher number of cigarettes per day. The Hispanic adolescents reported perceiving less acceptance from the neighborhood environment in which they live, whereas their parents reported monitoring their teens less than the parents' of White non-Hispanic adolescents. Consistent with the findings found in community samples, the overall findings of this study suggest that Hispanic and White non-Hispanic adolescents enrolled in this alcohol intervention have similar baseline characteristics.

The significance of marijuana use among alcohol-using adolescent emergency department patients

OBJECTIVES

The objective was to determine if adolescents presenting to a pediatric emergency department (PED) for an alcohol-related event requiring medical care differ in terms of substance use, behavioral and mental health problems, peer relationships, and parental monitoring based on their history of marijuana use.

METHODS

This was a cross-sectional comparison of adolescents 13-17 years old, with evidence of recent alcohol use, presenting to a PED with a self-reported history of marijuana use. Assessment tools included the Adolescent Drinking Inventory, Adolescent Drinking Questionnaire, Young Adult Drinking and Driving Questionnaire, Center for Epidemiologic Studies Depression Scale, Behavioral Assessment System for Children, and Peer Substance Use and Tolerance of Substance Use Scale.

RESULTS

Compared to adolescents using alcohol only (AO), adolescents who use alcohol and marijuana (A+M) have higher rates of smoking (F = 23.62) and binge drinking (F = 11.56), consume more drinks per sitting (F = 9.03), have more externalizing behavior problems (F = 12.53), and report both greater peer tolerance of substance use (F = 12.99) and lower parental monitoring (F = 7.12).

CONCLUSIONS

Adolescents who use A+M report greater substance use and more risk factors for substance abuse than AO-using adolescents. Screening for a history of marijuana use may be important when treating adolescents presenting with an alcohol-related event. A+M co-use may identify a high-risk population, which may have important implications for ED clinicians in the care of these patients, providing parental guidance, and planning follow-up care.

Alcohol-related visits to the emergency department by injured adolescents: a national perspective

PURPOSE

Alcohol use is a risk factor for injury in adolescents. Many injured adolescents require treatment in emergency departments (EDs). The present study was intended to explore this association between adolescent alcohol use and injury-related ED visits using the National Hospital Ambulatory Medical Care Survey (NHAMCS), a nationally representative probability sample of visits to EDs.

METHODS

This was a retrospective, cross-sectional study using data from NHAMCS for 2001 through 2004. ED visits by injured adolescents aged 13-20 years whose visits were determined by NHAMCS coders to be related to alcohol were compared with visits by those whose visits were determined not related to alcohol. Specific variables of interest included demographic and medical characteristics of visits.

RESULTS

Our analyses indicated that there were several visit-related characteristics that were associated with alcohol-related ED visits, including time of visit, type of health insurance, and geographic location of the ED. Similarly, there were a number of patient-related characteristics that were also associated with alcohol-related visits to the ED, including patient acuity and injury intentionality.

CONCLUSIONS

Our findings suggest that injured adolescents are more likely to present to the ED with an alcohol-related visit during the early hours of the morning, that the injury is more likely to be assault related and of higher acuity than non-alcohol-related visits. These findings suggest the ED as a potential site for alcohol prevention interventions with younger adolescents. However, these interventions will need to take into account when such adolescents will present to the ED and will need also to recognize that factors such as violence and aggression, in addition to alcohol use, may be important issues to address in the intervention.

The asthma/mental health nexus in a population-based sample of the United States

BACKGROUND

Asthma is one of the most prevalent chronic medical conditions in the United States. The relationship of asthma with psychological factors has been known for centuries, and recently there has been a resurgence of interest in this topic. This study investigates the relationship between current asthma and poor mental health in a nationally representative sample of the US population.

METHODS

This study utilizes data from the 2006 Behavioral Risk Factor Surveillance System survey (n = 355,710). A multinomial logistic regression model was constructed to assess the relationship between current asthma and poor mental health. The relationship between formerly having asthma and poor mental health was also investigated.

RESULTS

Persons reporting poor mental health have increased risk of currently having asthma compared to persons reporting good mental health. Additionally, this asthma/mental health relationship has a "dose-response" relationship. For every incremental increase in days of poor mental health, there is a corresponding increase in risk of currently having asthma. Previously reported risk factors for asthma (ie, age, gender, race, marital, smoking, overall health, exercise, obesity, and socioeconomic status) were all found to be important covariates of asthma. The relationship between former asthma and poor mental health is less clear.

CONCLUSIONS

This large, nationally representative sample confirms the relationship between asthma and mental health symptoms. Any degree of poor mental health appears to increase one's risk for asthma. Future research is needed to determine the causal and/or physiologic relationship between asthma and mental health symptoms.

Coordinate regulation of endothelin and adrenomedullin secretion by oxidative stress in endothelial cells

To elucidate the significance of oxidative stress in the modulation of endothelial functions, we examined the effects of H(2)O(2) on the expression of two endothelium-derived vasoactive peptides, endothelin (ET) and adrenomedullin (Am), and their interaction. H(2)O(2) dose dependently suppressed ET secretion and ET-1 mRNA expression in bovine carotid endothelial cells (ECs). Menadion sodium bisulfate, a redox cycling drug, also decreased ET secretion in a dose-dependent manner. Catalase, a H(2)O(2) reductase, and dl-alpha-tocopherol (vitamin E) significantly inhibited H(2)O(2)-induced suppression of ET secretion. Downregulation of ET-1 mRNA under oxidative stress was regulated at the transcriptional level. In contrast, H(2)O(2) increased Am secretion (and its mRNA expression) accompanied by the augmentation of cAMP production. Am, as well as 8-bromo-cAMP and forskolin decreased ET secretion in a dose-dependent fashion. Furthermore, an anti-Am monoclonal antibody that we developed abolished H(2)O(2)-induced suppression of ET secretion at 6-24 h after the addition of H(2)O(2). H(2)O(2) increased the intracellular Ca(2+) concentration ([Ca(2+)](i)). Moreover, treatment with ionomycin, a Ca(2+) ionophore, and thapsigargin, an inhibitor of endoplasmic reticulum ATPase, decreased ET secretion dose dependently for 3 h. These results suggest that the production of ET was decreased via activation of the Am-cAMP pathway and by the elevation of [Ca(2+)](i) under oxidative stress. These findings elucidate the coordinate expression of two local vascular hormones, ET and Am, under oxidative stress, which may protect against vascular diseases.

Thiazolidinediones, peroxisome proliferator-activated receptor gamma agonists, regulate endothelial cell growth and secretion of vasoactive peptides

Insulin resistance has been highlighted as a common causal factor for glucose intolerance, hypertension and dyslipidemia, all of which are cardiovascular risk factors. A new class of antidiabetic agents, thiazolidinediones (TZDs), has been developed and demonstrated to improve insulin sensitivity. TZDs are high affinity ligands for peroxisome proliferator-activated receptor gamma (PPARgamma), the crucial transcription factor for adipocytes. Recent studies showed that PPARgamma is also expressed in monocytes/macrophages and is suggested to be involved in atherosclerosis. We could detect PPARgamma gene transcript in several cultured endothelial cells (human aortic endothelial cells (HAoECs), human coronary artery endothelial cells (HCAECs), human umbilical vein endothelial cells (HUVECs) and bovine carotid artery endothelial cells (BAECs)) as well as human coronary arteries we examined. Since endothelial dysfunction is critical for atherosclerosis, we investigated the effects of TZDs, troglitazone (TRO) and pioglitazone (PIO), on endothelial cell growth and secretion of C-type natriuretic peptide (CNP), which we demonstrated as a novel endothelium-derived relaxing peptide, and endothelin (ET), a potent vasoconstrictor, using HAoECs, HCAECs, HUVECs and BAECs. When all these cultured endothelial cells were daily treated with TRO and PIO for 5 days, both TRO and PIO (10(-8)M) significantly stimulated (3)H-thymidine incorporation of all these endothelial cells. In contrast, higher dose of TRO and PIO (10(-5)M) significantly suppressed DNA synthesis. TRO and PIO also exerted the compatible effect on the increase of cell numbers. TRO and PIO significantly enhanced CNP secretion from BAECs. In contrast, ET secretion from BAECs was suppressed by both TRO and PIO in a dose-dependent manner. The results of the present study suggest that TZDs modulate endothelial functions, including regulation of endothelial cell growth and secretion of endothelium-derived vasoactive substances, which affect vascular tone and remodeling in the process of atherosclerosis.

C-type natriuretic peptide induces redifferentiation of vascular smooth muscle cells with accelerated reendothelialization

We recently reported that C-type natriuretic peptide (CNP) occurs in vascular endothelial cells and acts as a vascular-type natriuretic peptide. In the present study, we stimulated the cGMP cascade in proliferating smooth muscle cells (SMCs), in which particulate guanylate cyclase-B, the specific receptor for CNP, is predominantly expressed, by use of an adenovirus encoding rat CNP cDNA (Ad.CNP). In the Ad.CNP-treated cultured SMCs, CNP caused the growth inhibition of SMCs at G(1) phase with an early increase of p21(CIP1/WAF1) expression and subsequent upregulation of p16(INK4a). The expression of smooth muscle myosin heavy chain-2, which is the molecular marker of highly differentiated SMCs, was reinduced in the Ad.CNP-treated SMCs. The Ad.CNP-treated SMCs also reexpressed particulate guanylate cyclase-A, which shows high affinity to atrial and brain natriuretic peptide and is exclusively expressed in well-differentiated SMCs. CNP, which was overexpressed in rabbit femoral arteries in vivo at the time of balloon injury, significantly suppressed neointimal formation. Furthermore, an enhancement of the expression of smooth muscle myosin heavy chain-2 occurred in the residual neointima. In addition, early regeneration of endothelial cells was observed in the Ad.CNP-infected group. Thus, stimulation of cGMP cascade in proliferating dedifferentiated SMCs can induce growth inhibition and redifferentiation of SMCs with accelerated reendothelialization.

Oxidized LDL regulates vascular endothelial growth factor expression in human macrophages and endothelial cells through activation of peroxisome proliferator-activated receptor-gamma

Vascular endothelial growth factor (VEGF) has been recognized as an angiogenic factor that induces endothelial proliferation and vascular permeability. Recent studies have also suggested that VEGF can promote macrophage migration, which is critical for atherosclerosis. We have reported that VEGF is remarkably expressed in activated macrophages, endothelial cells, and smooth muscle cells within human coronary atherosclerotic lesions, and we have proposed the significance of VEGF in the progression of atherosclerosis. To clarify the mechanism of VEGF expression in atherosclerotic lesions, we examined the regulation of VEGF expression by oxidized low density lipoprotein (Ox-LDL), which is abundant in atherosclerotic arterial walls. A recent report has revealed that peroxisome proliferator-activated receptor-gamma (PPARgamma) is expressed not only in adipocytes but also in monocytes/macrophages and has suggested that PPARgamma may have a role in the differentiation of monocytes/macrophages. Furthermore, 9- and 13-hydroxy-(S)-10,12-octadecadienoic acid (9- and 13-HODE, respectively), the components of Ox-LDL, may be PPARgamma ligands. Therefore, we investigated the involvement of PPARgamma in the regulation of VEGF by Ox-LDL. PPARgamma expression was detected in human monocyte/macrophage cell lines, human acute monocytic leukemia (THP-1) cells, and human coronary artery endothelial cells (HCAECs). Ox-LDL (10 to 50 microg/mL) upregulated VEGF secretion from THP-1 dose-dependently. VEGF mRNA expression in HCAECs was also upregulated by Ox-LDL. The mRNA expression of VEGF in THP-1 cells and HCAECs was also augmented by PPARgamma activators, troglitazone (TRO), and 15-deoxy-(12,14)-prostaglandin J(2) (PGJ2). In contrast, VEGF expression in another monocyte/macrophage cell line, human histiocytic lymphoma cells (U937), which lacks PPARgamma expression, was not augmented by TRO or PGJ2. We established the U937 cell line, which permanently expresses PPARgamma (U937T). TRO and Ox-LDL augmented VEGF expression in U937T. In addition, VEGF production by THP-1 cells was significantly increased by exposure to 9-HODE and 13-HODE. In conclusion, Ox-LDL upregulates VEGF expression in macrophages and endothelial cells, at least in part, through the activation of PPARgamma.

Altered gene expression of uncoupling protein-2 and -3 in stroke-prone spontaneously hypertensive rats

BACKGROUND

Uncoupling proteins (UCPs) are the inner mitochondrial membrane-associated proteins, which dissipate the proton gradient and generate heat instead of ATP. The involvement of UCPs in energy expenditure and glucose metabolism has been suggested. Recently, we succeeded in cloning of rat UCP2 and UCP3.

OBJECTIVE

The aim of this study was to elucidate the pathophysiological role of UCP2 and UCP3 in hypertension associated with hyperglycemia in stroke-prone spontaneously hypertensive rats (SHR-SP).

METHODS

UCP2 and UCP3 mRNA levels of cardiac and gastrocnemius muscles in SHR-SP and Wistar-Kyoto (WKY) rats were determined at 6 weeks (prehypertensive stage) and at 15 weeks (hypertensive stage).

RESULTS

UCP2 and UCP3 mRNA levels in the heart of SHR-SP at 6 weeks were significantly higher than those of WKY rats (1.6-fold, 3.6-fold, respectively). These tendencies did not change in the heart at 15 weeks. UCP2 and UCP3 mRNA levels in the skeletal muscle of SHR-SP at 6 weeks were significantly higher than those of WKY rats (1.4-fold, 2.4-fold, respectively). In contrast, at 15 weeks, UCP2 and UCP3 mRNA levels in the skeletal muscle of SHR-SP were significantly lower than those of WKY rats (70 and 36% of WKY rats, respectively). Therefore, the decrease of UCP2 and UCP3 in the skeletal muscle was observed with the concomitant development of hypertension in SHR-SP. UCP2 mRNA levels in the epididymal fat of SHR-SP at 15 weeks were similar to that of WKY rats.

CONCLUSIONS

Altered gene expression of UCP2 and UCP3 might be related to some pathophysiological aspects in hypertension and glucose metabolism in SHR-SP.

Inhibition of rho-associated kinase results in suppression of neointimal formation of balloon-injured arteries

BACKGROUND

Rho-associated kinase (ROCK), an effector of small GTPase Rho, regulates vascular tone via a calcium sensitization mechanism and plays a key role in the pathogenesis of hypertension. However, its role in vascular growth remains unclear.

METHODS AND RESULTS

Y-27632, a specific ROCK inhibitor, and the overexpression of dominant-negative ROCK suppressed the mitogen-induced DNA synthesis of cultured vascular smooth muscle cells (VSMCs), which indicates the essential role of ROCK in the control of VSMC proliferation in vitro. Y-27632 also suppressed the chemotaxis of VSMCs. Male Wistar rats were systemically given Y-27632 (35 to 70 mg. kg(-1). day(-1)) through an intraperitoneal infusion. The neointimal formation of balloon-injured carotid arteries was significantly suppressed in Y-27632-treated rats (intima/media ratio, 0.22+/-0.02) compared with vehicle-treated rats (intima/media ratio, 0.92+/-0.21) or hydralazine-treated rats with a similar blood pressure decrease (intima/media ratio, 1.03+/-0.15). The phosphorylation of myosin phosphatase and myosin light chain was elevated in injured arteries in a Y-27632-sensitive manner, indicating the augmentation of ROCK activity in neointimal formation. The downregulation of the cyclin-dependent kinase inhibitor p27(kip1) in injured vessels was reversed by Y-27632 treatment, reflecting the antiproliferative effect of ROCK inhibition in vivo.

CONCLUSIONS

We conclude that ROCK plays a key role in the process of neointimal formation after balloon injury. Thus, the inhibition of ROCK may be a potential therapeutic strategy for treating vascular proliferative disorders and hypertension.

Oxidative stress augments secretion of endothelium-derived relaxing peptides, C-type natriuretic peptide and adrenomedullin

OBJECTIVE

Excess oxidative stress is one of the major metabolic abnormalities on vascular walls in hypertension and atherosclerosis. In order to further elucidate the endothelial function under oxidative stress, the effect of hydrogen peroxide (H2O2) on expression of two novel endothelium-derived vasorelaxing peptides, C-type natriuretic peptide (CNP) and adrenomedullin (AM) from bovine carotid artery endothelial cells (BCAECs) was examined.

METHODS

BCAECs were treated with H2O2 (0.1-1.0 mmol/ l) and/or an antioxidant, N-acetylcysteine (NAC) (5-10 mmol/l), and incubated for 48 h. The concentrations of CNP and AM were measured with the specific radioimmuno assays that we originally developed. CNP and AM mRNA expressions were also examined by reverse transcription-polymerase chain reaction (RT-PCR).

RESULTS

Treatment of BCAECs with 0.5 and 1 mmol/l H2O2 induced 9-and 10-fold increases of CNP concentration in the media. Addition of 10 mmol/l NAC significantly suppressed the effect of H2O2 by 52%. RT-PCR analysis showed that CNP mRNA expression in BCAECs was also rapidly augmented within 1 h with H2O2 (1 mmol/l) treatment, and reached a peak at 3 h to show a 10-fold increase. AM secretion from BCAECs also increased to two-fold with exposure to 0.5 mmol/l H2O2, accompanied with the augmented level of AM mRNA. NAC 10 mmol/l completely suppressed the effect of H2O2 on AM secretion.

CONCLUSIONS

In this study, it has been demonstrated that H2O2 augments endothelial secretion of the two endothelium-derived relaxing peptides, CNP and AM. Our findings suggest the increased secretion of CNP and AM from endothelium under oxidative stress may function to compensate the impaired nitric oxide-dependent vasorelaxation in hypertension and atherosclerosis.

Down regulation of peroxisome proliferator-activated receptorgamma expression by inflammatory cytokines and its reversal by thiazolidinediones

AIMS/HYPOTHESIS

Previous studies show that inflammatory cytokines play a part in the development of insulin resistance. Thiazolidinediones were developed as insulin-sensitizing drugs and are ligands for the peroxisome proliferator-activated receptory (PPARgamma). We hypothesized that the anti-diabetic mechanism of thiazolidinediones depends on the quantity of PPARgamma in the insulin resistant state in which inflammatory cytokines play a part.

METHODS

We isolated rat PPARgamma1 and gamma2 cDNAs and examined effects of various cytokines and thiazolidinediones on PPARgamma mRNA expression in rat mature adipocytes.

RESULTS

Various inflammatory cytokines, such as tumour necrosis factor-alpha (TNF-alpha), interleukin-1alpha (IL-1alpha), IL-1beta, IL-6 and leukaemia inhibitory factor decreased PPARgamma mRNA expression. In addition, hydrogen peroxide, lysophosphatidylcholine or phorbol 12-myristate 13-acetate also decreased the expression of PPARgamma. The suppression of PPARgamma mRNA expression caused by 10 nmol/l of TNF-alpha was reversed 60% and 55% by treatment with 10(-4) mol/l of troglitazone and 10(-4) mol/l of pioglitazone, respectively. The suppression of glucose transporter 4 mRNA expression caused by TNF-alpha was also reversed by thiazolidinediones. Associated with the change of PPARgamma mRNA expression, troglitazone improved glucose uptake suppressed by TNF-alpha.

CONCLUSION/INTERPRETATION

Our study suggests that inflammatory cytokines could be factors that regulate PPARgamma expression for possible modulation of insulin resistance. In addition, we speculate that the regulation of PPARgamma mRNA expression may contribute to the anti-diabetic mechanism of thiazolidinediones.

Vascular endothelial growth factor (VEGF) expression in human coronary atherosclerotic lesions: possible pathophysiological significance of VEGF in progression of atherosclerosis

BACKGROUND

Vascular endothelial growth factor (VEGF) is an important angiogenic factor reported to induce migration and proliferation of endothelial cells, enhance vascular permeability, and modulate thrombogenicity. VEGF expression in cultured cells (smooth muscle cells, macrophages, endothelial cells) is controlled by growth factors and cytokines. Hence, the question arises of whether VEGF could play a role in atherogenesis.

METHODS AND RESULTS

Frozen sections from 38 coronary artery segments were studied. The specimens were characterized as normal with diffuse intimal thickening, early atherosclerosis with hypercellularity, and advanced atherosclerosis (atheromatous plaques, fibrous plaques, and totally occlusive lesions). VEGF expression as well as the expression of 2 VEGF receptors, flt-1 and Flk-1, were studied with immunohistochemical techniques in these samples at the different stages of human coronary atherosclerosis progression. The expression of VEGF mRNA was also studied with reverse transcription-polymerase chain reaction. Normal arterial segments showed no substantial VEGF expression. Hypercellular and atheromatous lesions showed distinct VEGF positivity of activated endothelial cells, macrophages, and partially differentiated smooth muscle cells. VEGF positivity was also detected in endothelial cells of intraplaque microvessels within advanced lesions. In totally occlusive lesions with extensive neovascularization, intense immunostaining for VEGF was observed in accumulated macrophages and endothelial cells of the microvessels. Furthermore, VEGF mRNA expression was detected in atherosclerotic coronary segments but not in normal coronary segments. The immunostainings for flt-1 and Flk-1 were detected in aggregating macrophages in atherosclerotic lesions and also in endothelial cells of the microvessels in totally occlusive lesions.

CONCLUSIONS

These results demonstrate distinct expression of VEGF and its receptors (flt-1 and Flk-1) in atherosclerotic lesions in human coronary arteries. Considering the multipotent actions of VEGF documented experimentally in vivo and in vitro, our findings suggest that VEGF may have some role in the progression of human coronary atherosclerosis, as well as in recanalization processes in obstructive coronary diseases.