Achievement of Target Gain Larger than Unity in an Inertial Fusion Experiment

On December 5, 2022, an indirect drive fusion implosion on the National Ignition Facility (NIF) achieved a target gain G_{target} of 1.5. This is the first laboratory demonstration of exceeding "scientific breakeven" (or G_{target}>1) where 2.05 MJ of 351 nm laser light produced 3.1 MJ of total fusion yield, a result which significantly exceeds the Lawson criterion for fusion ignition as reported in a previous NIF implosion [H. Abu-Shawareb et al. (Indirect Drive ICF Collaboration), Phys. Rev. Lett. 129, 075001 (2022)PRLTAO0031-900710.1103/PhysRevLett.129.075001]. This achievement is the culmination of more than five decades of research and gives proof that laboratory fusion, based on fundamental physics principles, is possible. This Letter reports on the target, laser, design, and experimental advancements that led to this result.

Similar skills, different frames: a thematic analysis exploring conceptualizations held by community-based organization practitioners and academics regarding skills to use evidence-based interventions to address cancer inequities

BACKGROUND

Community-based organizations (CBOs) are critical partners in delivering evidence-based interventions (EBIs) to address cancer inequities. However, CBO practitioners do not typically have access to opportunities to build the necessary capacity (skills, knowledge, motivation, and resources) for using EBIs. Although capacity-building interventions can offer a solution, inconsistent definitions and measurements of capacity limit the ability to develop and evaluate such efforts. We explored how and why conceptualizations of core skills for EBI use differ between practitioners and academics addressing cancer and other health inequities. We anchored the inquiry with a commonly used set of target skills for EBI capacity-building efforts.

METHODS

The study was conducted by an interdisciplinary team of academic researchers and CBO practitioners. We gathered data through semi-structured, hour-long interviews with practitioners and academics working to address cancer and other health inequities (n = 19). After hearing a brief vignette about a CBO addressing cervical cancer inequities, participants considered a widely accepted list of skills for EBI use that included assessing needs, engaging stakeholders, and selecting, adapting, implementing, evaluating, and sustaining the EBI. We used a team-based, reflexive thematic analysis approach grounded in critical and constructivist perspectives.

RESULTS

Overall, the original list resonated with practitioners and academics and they added new skills to the list (cultural humility and systems change). Practitioners' responses described skills from the reference point of addressing broader community needs and context and achieving change over the long term, emphasizing aspects of health promotion in their descriptions. Academics offered a mix of perspectives, with some focused on addressing community needs (and related flexibility regarding EBIs) but more emphasized skills needed to deliver a specific EBI to achieve a focused set of health and equity outcomes.

CONCLUSIONS

There is a significant opportunity to leverage complementary expertise and perspectives held by practitioners and academics addressing cancer inequities. However, the different frames utilized suggest proactive efforts will be required to find alignment across groups, particularly in valuing diverse contributions and identifying relevant outcomes of interest for each group. Such alignment is critical to designing effective capacity-building interventions and supporting the routine utilization of EBIs to address cancer inequities.

Priority skills for equity-focused, evidence-based cancer control in community-based organizations: A group concept mapping analysis with academics and practitioners

Introduction

Community-based organizations (CBOs) are important equity-promoting delivery channels for evidence-based interventions (EBIs). However, CBO practitioners often cannot access needed support to build EBI skills. Additionally, the capacity-building literature is hindered by inconsistent definitions, limited use of validated measures, and an emphasis on the perspectives of EBI developers versus implementers. To address these gaps, we explored commonalities and differences between CBO practitioners and academics in conceptualizing and prioritizing core EBI skills.

Methods

We utilized Group Concept Mapping, a mixed-methods approach connecting qualitative data (e.g., regarding the range of critical EBI skills) and quantitative data (e.g., sorting and ranking data regarding unique skills) to create conceptual maps integrating perspectives from diverse participants. A total of 34 practitioners and 30 academics working with cancer inequities participated in the study.

Results

Participants nominated 581 core skills for EBI use, and our team (including practitioners and academics) identified 98 unique skills from this list. Participants sorted them into conceptual groups, yielding five clusters: (1) using data and evaluation, (2) selecting and adapting EBIs, (3) connecting with community members, (4) building diverse and equitable partnerships, and (5) managing EBI implementation. The ordering of importance and presence of skill clusters were similar across groups. Overall, importance was rated higher than presence, suggesting capacity gaps.

Conclusions

There are helpful commonalities between practitioners' and academics' views of core EBI skills in CBOs and apparent capacity gaps. However, underlying patterns suggest that differences between the groups' perceptions warrant further exploration.

Lawson Criterion for Ignition Exceeded in an Inertial Fusion Experiment

For more than half a century, researchers around the world have been engaged in attempts to achieve fusion ignition as a proof of principle of various fusion concepts. Following the Lawson criterion, an ignited plasma is one where the fusion heating power is high enough to overcome all the physical processes that cool the fusion plasma, creating a positive thermodynamic feedback loop with rapidly increasing temperature. In inertially confined fusion, ignition is a state where the fusion plasma can begin "burn propagation" into surrounding cold fuel, enabling the possibility of high energy gain. While "scientific breakeven" (i.e., unity target gain) has not yet been achieved (here target gain is 0.72, 1.37 MJ of fusion for 1.92 MJ of laser energy), this Letter reports the first controlled fusion experiment, using laser indirect drive, on the National Ignition Facility to produce capsule gain (here 5.8) and reach ignition by nine different formulations of the Lawson criterion.

0201 Sleep duration and timing is prospectively linked with increases in insulin resistance over late adolescence

Introduction

During puberty, adolescents experience a period of transient insulin resistance (IR) that normalizes upon full maturation. Yet, IR continues to rise for some adolescents, increasing metabolic disease and type 2 diabetes risk in adulthood. Whether short sleep duration and/or later sleep timing are risk factors for persistently increasing IR in late adolescence has not been explored.

Methods

The study population includes 362 adolescents from Mexico City enrolled in a longitudinal birth cohort (ELEMENT study). Beginning in 2015, when participants were between the ages of 9 and 17, there were 2 clinic visits that occurred approximately 2 years apart. During the visit, a fasting blood sample and anthropometric measurements were taken. Insulin resistance was assessed with glucose and insulin via HOMA-IR. Four groups were defined using puberty-specific cutpoints for IR: normal HOMA-IR over the follow-up period (reference), transition from normal to IR, transition from IR to normal, and IR at both time points. Baseline sleep assessments (sleep duration, timing, and variability of both duration and timing) were measured with 7-day actigraphy. Multinomial logistic regression models were used to evaluate associations between sleep duration and timing with HOMA-IR categories, adjusting for age, sex, and baseline pubertal status

Results

Seventeen percent of the sample developed insulin resistance over the follow-up period. Adolescents ≥1 hour below the sleep duration recommendations-for-age were over twice as likely to be in the group that developed IR compared to the normal group (95% CI 1.1, .9; P for trend=0.03). Similarly, adolescents who had a sleep midpoint later than 4:36 AM were 2.77 times as likely to be in the increasing HOMA-IR category (95% CI 1.0, 7.5; P for trend=0.05). Interestingly, there was no evidence that changes in adiposity over follow-up mediated associations between sleep and insulin resistance.

Conclusion

Insufficient sleep duration and late sleep timing were independently associated with development of IR over a 2-year period in peri-puberty. Adequate sleep during the pubertal period may promote metabolic health into young adulthood, independent of any changes in adiposity.

Support (If Any)

Dr. Jansen is supported by K01HL151673. The study is supported by P01 ES02284401.

Gestational exposure to high fat diets and bisphenol A alters metabolic outcomes in dams and offspring, but produces hepatic steatosis only in dams

The prevalence of non-alcoholic fatty liver disease (NAFLD) is increasing worldwide. Perinatal development is a critical window for altered, lifelong health trajectory, and evidence supports the role of perinatal programming in chronic metabolic diseases. To examine the impact of diet and bisphenol A (BPA) on the developmental trajectory of NAFLD in offspring, we exposed dams from pre-gestation through lactation to a human-relevant dose of oral BPA coupled with intake of high fat Western or Mediterranean-style diets. We assessed hepatic steatosis by quantifying hepatic triglycerides (TGs) and metabolic health by measuring body weight, relative organ weights, and serum hormone levels in dams and offspring at postnatal day 10 (PND10) and 10-months of age. In dams, consumption of the Western or Mediterranean diet increased hepatic TGs 1.7-2.4-fold, independent of BPA intake. Among offspring, both perinatal diet and BPA exposure had a greater impact on metabolic outcomes than on hepatic steatosis. At PND10, serum leptin levels were elevated 2.6-4.8-fold in pups exposed to the Mediterranean diet, with a trend for sex-specific effects on body and organ weights. At 10-months, sex-specific increases in organ weight and hormone levels were observed in mice perinatally exposed to Western + BPA or Mediterranean + BPA. These findings suggest lifestage-specific interaction of perinatal exposures to experimental diets and BPA on offspring metabolic health without effects on NAFLD later in life. Importantly, alterations in dam phenotype by diet and BPA exposure appear to impact offspring health trajectory, emphasizing the need to define dam diet in assessing effects of environmental exposures on offspring health.

Changes in Sugar Sweetened Beverage Intake Related to Changes in Body Composition in Mexican Adolescents

Objectives

To examine the relationship between changes in sugar sweetened beverage (SSB) intake and changes in adiposity over a two-year period during adolescence in a Mexico City cohort.

Methods

The analytic sample comprised 511 Mexican adolescents enrolled in a birth cohort study with complete information on sugar sweetened beverage intake and body composition for two time points. In 2015 and 2017, a food frequency questionnaire (FFQ) from the 2006 Mexican National Health and Nutrition Survey was administered to participants ages 9 to 20. Seven variables from the FFQ were summed to use as daily servings of SSBs as a predictor: regular soda, coffee with sugar, tea with sugar, sweetened fruit water, chocolate milk, corn atole, and Yakult (sweetened probiotic milk beverage). Adiposity measurements included body mass index (BMI), body fat % estimated by bioelectrical impedance, and waist circumference, measured by trained research assistants using standard techniques. We used linear regression models with changes in adiposity measures as the continuous outcome and quartiles of change in sugar sweetened beverage intake as the predictor adjusting for age, sex, household socioeconomic status, screen time, and physical activity.

Results

At baseline (2015), mean age was 14.5 ± 2.1 years with 48% male. The median intake of SSBs was 341 mL/day (IQR = 463 mL) for males and 257 mL/day (IQR = 391 mL) for females. The median SSB intake change over the 2-year period was a 51 mL decrease (IQR = 441 mL) for males and no change (IQR = 360 mL) for females. In adjusted analyses, adolescents with the highest change in SSB intake (Quartile 4,274.3 mL median (IQR = 297.1) increase in SSB intake) had a 0.30 increase kg/m2 in BMI (95% CI −0.15, 0.75), a 1.14% increase in body fat (95% CI −0.02, 2.31), and a 1.64 cm increase in waist circumference (95% CI 0.27, 3.00), compared to those with decreases or no change in SSB intake.

Conclusions

Increased intake of sugar sweetened beverages was associated with higher changes in body fat percentage, waist circumference, and BMI over a two-year period among Mexican adolescents.

Funding Sources

This project was supported by a P01 research grant through the NIH/NIEHS.

Prenatal Diet in Relation to Sleep Health of Offspring During Adolescence: Evidence From the ELEMENT Study

Objectives

Maternal diet during gestation has been linked to sex-specific differences in infant sleep; however, the impact on sleep into adolescence is unknown. We sought to examine the relationship between maternal diet patterns and sex-stratified offspring sleep health during adolescence among a Mexico City cohort.

Methods

Data from 309 mother-adolescent dyads were analyzed. Prenatal diet patterns were formed by principal component analysis derived from a food frequency questionnaire collected over the third trimester. Sleep variables were derived from 7-day actigraphy data from adolescents aged 9–17 years. Linear regression was employed to examine sex-stratified associations between tertiles of the diet patterns with adolescent sleep, adjusting for confounding factors.

Results

Three diet patterns included: the Prudent Diet (PD), high in lean proteins and vegetables; the Transitioning Mexican Diet (TMD) high in Mexican and “Westernized” foods; and the High Meat & Fat Diet (HMFD), high in meats and high-fat dairy products. The mean (SD) offspring age was 15.1 (1.9) years, and 52.4% of the sample was female. The mean (SD) sleep duration was 8.4 (1.4) h/night. Adjusted analyses showed an association between PD adherence and earlier sleep midpoint among female offspring, the offspring of mothers in the highest tertile of PD had a 0.70 h (95% CI: −1.2, −0.20; p = 0.01) earlier sleep midpoint (p, trend = 0.01). Additional associations were detected between TMD prenatal adherence with shorter sleep duration and earlier sleep midpoint among both sexes. For example, female and male offspring of mothers in the highest tertile of TMD had 0.80 h (95% CI: −85.0, −10.6; p = 0.01) (p, trend = 0.0043) and 0.54 h (95% CI: −66.1, 1.3) (p, trend = 0.03) shorter sleep duration, respectively. HMFD prenatal adherence was associated with less fragmented sleep in a non-linear manner among females and was non-linearly associated with an earlier sleep midpoint among males.

Conclusions

Sex-stratified analyses demonstrated that findings were more robust between multiple diet patterns and shorter sleep, earlier sleep timing, and less fragmented sleep among female offspring, thus indicating that maternal diet during pregnancy may impact female offspring's sleep health in adolescence.

Funding Sources

US EPA, NIEHS, NHLBI, and the National Institute of Public Health/Ministry of Health of Mexico.

Plasma Fatty Acid Biomarkers of Dairy Consumption Are Associated With Sex-Dependent Effects on MetS Components in Mexican Adolescents

Objectives

This study investigates the association between plasma fatty acids (FAs) related to dairy intake and dairy portions with Metabolic Syndrome (MetS) components in Mexican adolescents.

Methods

A total of 311 participants from the Early Life Exposures in Mexico to Environmental Toxicants (ELEMENT) cohort were included in this cross-sectional analysis. Fasting blood samples were collected to assess the concentration of FAs in plasma. Dairy intake was assessed using a 7-day recall Food Frequency Questionnaire to determinate dairy servings per day. The following dairy biomarkers were used in analysis: pentadecanoic acid (C15:0), heptadecanoic acid (C17:0), and trans-palmitoleic acid (t-C16:1n-7). MetS components included waist circumference (WC), blood pressure, HDL-cholesterol, triglycerides, glucose, and insulin. Linear regression models stratified by sex were fit to explore the association between plasma FAs tertiles and dairy portions (low fat/high fat) with MetS components as continuous variables, adjusted by age, socioeconomic status, sedentary behavior, BMI, pubertal status, and energy intake.

Results

The mean age was 14.0 years (SD ± 2.0) and 50.6% were male. Significant associations between tertiles of dairy FAs and MetS components were found. In females, C17:0 (T2 vs T1: β = −2.0; 95% CI: −3.0, −0.1) and t-C16:1n-7 (T3 vs T1: β −3.1; 95% CI: −4.8, −1.1) were negatively associated with WC. Similarly, in males, t-C16:1n-7 was negatively associated with WC (T2 vs T1: β = −2.0; 95% CI: 4.1, −0.04, P = 0.05) and insulin (T2 vs T1: β −4.1; 95% CI: −7.1, −0.7). In female C17:0 was also negatively associated with HDL (T2 vs T1: β = −3.9; 95% CI: −7.4, −0.2). In contrast, C15:0 in females (T3 v2 T1: β = 44.5; 95% CI: 22.5, 66.5) and t-C16:1n-7 in male (T3 vs T1: β = 21.2; 95% CI: 1.7, 40.6) was related to increased triglycerides. High fat dairy portions were negatively associated with WC (β −0.86; 95% CI: −1.4, −0.28) in female. In contrast, low fat dairy portions were negatively associated with HDL-C (β −1.7; 95% CI: −3.4, −0.1).

Conclusions

Our results suggest that adolescent dairy intake, assessed through FAS levels, may be associated in different ways with cardiovascular risk factors, and that associations are sex-dependent.

Funding Sources

The study is supported by National Institutes of Health. FAs analysis was funded by the University of Michigan Momentum Center.

A Prospective Study of Prenatal Maternal Dietary Patterns and Offspring Adipokine Levels During Adolescence

Objectives

Maternal diet during pregnancy has been associated with offspring adipokine levels related to insulin resistance and hyperlipidemia during infancy. However, whether this relationship persists into adolescence is unknown. We examined the association between maternal prenatal diet patterns with adolescent leptin and adiponectin levels a Mexico City cohort.

Methods

Data from 379 mother-adolescent dyads from the Mexico City ELEMENT cohort were analyzed. Diet patterns were derived from principal component analysis of food frequency questionnaire data collected during pregnancy trimesters. Adolescent serum leptin and adiponectin were measured at ages 10–17. Information on maternal covariates was measured during pregnancy. Multiple linear regression was used to examine overall and sex-stratified associations between quartiles of diet patterns with leptin and adiponectin, adjusting for maternal marital status, education, and parity.

Results

Three maternal diet patterns were identified: Prudent Diet (PD), high in fish and vegetables, the High Meat & Fat Diet (HMFD), high in pork and processed meats, and the Transitioning Diet (TD), high in corn tortillas and sugar beverages. At follow-up, the mean (SD) of leptin and adiponectin were 24.3 (18.2) ng/ml and 11.7 (3.9) ng/ml. A significant positive association was demonstrated between first trimester TD scores and adipokines in girls. In a multivariate-adjusted model, compared to girls in the lowest quartile (Q1) of the TD pattern, the highest quartile of the TD pattern (Q4) had 10.39 ng/mL higher leptin (95% CI: 3.1, 17.6; p for trend = 0.0024). In addition, compared to girls in the lowest quartile (Q1) of the TD pattern, those in the third quartile (Q3) of the TD pattern had 1.86 ng/mL lower adiponectin (95% CI: −3.5, −0.2; p for trend = 0.168). Associations were mostly consistent across all trimesters.

Conclusions

During pregnancy, a Transitioning Diet pattern was positively associated with leptin and non-monotonically inversely associated with adiponectin in females. Findings suggest maternal diet patterns during pregnancy may influence offspring leptin and adiponectin levels in adolescent girls.

Funding Sources

Funded by grant P01ES022844.

Metabolomic Profiling in Response to an Oral Glucose Tolerance Test Reveals Pathways Associated With Obesity and Insulin Resistance During the Pubertal Transition

Objectives

To reveal alterations in metabolic pathways in response to an oral glucose tolerance test (OGTT) underlying the development of insulin resistance during the pubertal transition.

Methods

Participants were recruited as healthy controls (HC, n = 55, aged 8.3–18.0 years, BMI percentile 5–85%) and overweight and obese individuals (OVOB, n = 228, aged 8.1–17.9 years, BMI percentile ≥ 85%). Participants were grouped based on their peak insulin response to the OGTT, stratified by peak at t30 (Group 1, n = 163), t60 (Group 2, n = 75), and t120 minutes (Group 3,

n = 44). Untargeted metabolomics profiled 267 annotated metabolites and > 3000 unannotated features in plasma at t0 and t60 minutes. Regression classified changes in metabolites across the time-course, assessing the influence of BMI and insulin response (FDR < 0.05). The connectivity of the metabolome was determined using differential network enrichment analysis (DNEA), stratified by insulin response group.

Results

At fasting, 32% of the metabolites differed between HC and OVOB, including elevated kynurenine, leucine/isoleucine, methionine, tyrosine, short-chain acylcarnitines, and diacylglycerols in OVOB. At t60, only 4% of the metabolites differed between HC and OVOB participants, suggesting a “normalization” of the metabolome, with exceptions of acylcarnitines and FA oxidation (FAO) intermediates. Although no metabolites differed significantly between insulin response group, differential subnetworks were observed, including increased connectivity between FA and FAO intermediates in Group 1 at t60, suggesting differential regulation in post-prandial FAs.

Conclusions

Profiling the metabolome response to an OGTT may highlight metabolic dysfunction prior to type 2 diabetes and will be used in future longitudinal analyses predicting insulin resistance trajectory.

Funding Sources

The National Institute of Child Health and Human Development, the National Institute of Diabetes and Digestive and Kidney Diseases, and the National Institutes of Health

Stem Cell-Laden Coaxially Electrospun Fibrous Scaffold for Regenerative Engineering Applications

Stem cell-based therapies for various ailments have attracted significant attention for over a decade. However, low retention of transplanted cells at the damaged site has hindered their potential for use in therapy. Tissue engineered grafts with fibrillar structures mimicking the extracellular matrix (ECM) can be potentially used to increase the retention and engraftment of stem cells at the damaged site. Moreover, these grafts may also provide mechanical stability at the damaged site to enhance function and regeneration. Among all the methods to produce fibrillar structures developed in recent years, electrospinning is a simple and versatile method to produce fibrous structures ranging from a few nanometers to micrometers. Coaxial electrospinning enables production of a mechanically stable core with a cell-binding sheath for enhanced cell adhesion and proliferation. Furthermore, this process provides an alternative to functionalized engineered scaffolds with specific compositions. The present article describes the protocol for developing a polycaprolactone (PCL) core and gelatin/gelatin methacrylate (GelMA) sheath laden with stem cells for various regenerative engineering applications. © 2021 Wiley Periodicals LLC. Basic Protocol 1: Uniaxial PCL electrospinning Basic Protocol 2: Coaxial electrospinning Support Protocol 1: Scaffold characterization for Basic Protocols 1 and 2 Basic Protocol 3: Cell seeding on uniaxial and coaxial electrospun scaffolds and MTS assay Support Protocol 2: Preparation of scaffold with cells for scanning electron microscopy.

Greater cumulative exposure to a pro-inflammatory diet is associated with higher metabolic syndrome score and blood pressure in young Mexican adults

Low-grade inflammation is a suggested mechanism in the development of metabolic syndrome (MetS), and diet could act as a regulator. Therefore, we hypothesized that the cumulative Dietary Inflammatory Index (DII®) exposure from diet during infancy through adulthood would be positively associated with the MetS and its components in young Mexican adults. One hundred participants from the Early Life Exposures in Mexico to Environmental Toxicants cohort were included in this analysis. The dietary inflammatory potential of the diet (without supplements) was assessed using 27 nutrients obtained from repeated food frequency questionnaires (1-22 years) using the DII, a validated score. The cumulative exposure of DII was constructed using the area under the curve (AUC of DII). The MetS was defined using the International Diabetes Federation criteria, and the Metabolic Syndrome Risk Z-score (MetRisk Z-score) was estimated. Linear regressions were conducted to assess the association between the AUC of DII with MetRisk Z-score and MetS components, adjusting for sex, socioeconomic status, smoking status, physical activity, birth weight, and body mass index. In adulthood, the mean age was 21.5 years, 54% were male, and 17% had MetS. Positive associations were found between AUC of DII with MetRisk Z-score (β = .12; 95% confidence interval [CI]: 0.03-0.22; P = .009) and systolic (β = .33; 95% CI: 0.05-0.61; P = .023) and diastolic blood pressure (β = .24; 95% CI: 0.01-0.47; P = .040). A cumulative proinflammatory diet from infancy through young adulthood is associated with higher MetRisk Z-scores as well as blood pressure. These findings may provide evidence for the implementation of anti-inflammatory diet interventions throughout early life for the prevention of cardiometabolic risk.

Abstract P206: Prenatal Cadmium Burden, Birth Weight, And Offspring Adolescent Blood Pressure

Background: Cadmium is a ubiquitous, toxic heavy metal associated with several adverse health outcomes, including high blood pressure, in adults. The impact of maternal cadmium burden on offspring birth weight and have not been thoroughly explored. We investigated associations of prenatal cadmium burden with birth weight and offspring blood pressure in childhood and adolescence.

Methods: We analyzed data from 202 mother-child pairs who were recruited for the Early Life Exposure in Mexico to Environmental Toxicants (ELEMENT) study in Mexico City (1997-2000). Prenatal cadmium burden was characterized using maternal urine collected in the third trimester of pregnancy - continuous and quartile specific-gravity adjusted cadmium (log-UCd, μg/L). Outcomes were offspring birth weight and blood pressure (measured at age 7-15 years). Blood pressure status (normal, elevated, stage 1 hypertension) was defined based on the 2017 American Academy of Pediatrics Guidelines. Those with elevated or stage 1 hypertension were categorized as having high blood pressure. Linear and logistic regression models were used to examine associations, adjusted for potential confounders. Potential effect modification by offspring sex was assessed using interaction terms and sex-stratified models.

Results: Study participants included 93 males and 109 females, with a mean age of 10.0 (SD=1.5) years. Median third trimester urinary cadmium concentration was 0.17 μg/L (IQR=0.12, 0.26). The prevalence of high blood pressure was 19.3% (39/202). Prenatal cadmium was not associated with birthweight (β=-58.94 grams, 95%CI: -138.07, 20.19), offspring systolic blood pressure (β=-0.90 mmHg, 95%CI: -2.87, 1.06), diastolic blood pressure (β=-1.21 mmHg, 95%CI: -2.68, 0.26), or high blood pressure (OR=0.64, 95%CI: 0.34, 1.21). We found similar results when prenatal cadmium was modeled with quartiles. There was no evidence of effect modification by sex for any of the outcomes.

Conclusions: In the current study, maternal third trimester was not associated with offspring blood pressure or birth weight, however future studies are needed to confirm these findings.

Estimating the causal effect of prenatal lead exposure on prepulse inhibition deficits in children and adolescents

During pregnancy, maternal lead from earlier exposures mobilizes and crosses placental barriers, placing the developing fetus at risk for lead exposure and neurodevelopmental deficits. Some neuronal circuits known to be affected in neurodevelopment disorders can be probed with simple physiological behavioral paradigms. One such neural biomarker is Pre-Pulse Inhibition (PPI), an indicator of adequate sensorimotor gating processing. In clinical studies, deficits in PPI have been associated with neurodevelopmental disorders in human subjects. To our knowledge, no studies have examined the use of PPI as a biomarker of toxicant effects on the brain in epidemiological studies. We aimed to estimate the causal effect of prenatal lead exposure, assessed by maternal cortical bone lead concentrations, on PPI in 279 children from Mexico City. in vivo maternal cortical bone lead measurements were taken at four weeks postpartum at the mid-tibia shaft using a K-Shell X-ray fluorescence instrument. PPI recording occurred in an isolated clinical setting and eye blink responses were measured using electromyography. We assessed if the conditions for causal inference held in our study and used the results of our assessment to estimate the causal effect of prenatal lead exposure on PPI using an ordinary least squares regression model, a marginal structural model, and the parametric g-formula. Results were consistent across the three modeling approaches. For the parametric g-formula, a one standard deviation (10.0 μg/g) increase in prenatal lead significantly reduced PPI by approximately 19.0 % (95 % CI: 5.4 %, 34.3 %). This decrease is similar in magnitude to clinical studies on schizophrenia, which have observed PPI impairments in patients with schizophrenia as compared to controls. Our results are consistent with findings from other studies establishing an association between lead exposure and neurodevelopmental disorders in children and suggest that PPI may be useful as an objective biomarker of toxicant effects on the brain.

Scientific evidence supporting recommendations on the use of the 9-valent HPV vaccine in a 2-dose vaccine schedule in Australia

The Australian Technical Advisory Group on Immunisation (ATAGI) updated recommendations on the use of human papillomavirus (HPV) vaccines in the Australian Immunisation Handbook in 2018, regarding the use of the recently available 9-valent (9vHPV) vaccine, Gardasil 9, and a 2-dose schedule for young adolescents for HPV vaccines. This report provides an overview of the relevant scientific evidence that underpinned these updated recommendations. The 9vHPV vaccine includes 5 HPV types (HPV 31, 33, 45, 52 and 58) additional to the 4 that are also covered by the 4vHPV (Gardasil) vaccine (HPV 6,11,16,18). Accordingly, the 9vHPV vaccine is expected to prevent an additional 15% of cervical cancers and up to 20% of other HPV-related cancers. Non-inferior antibody responses after two 9vHPV vaccine doses given 6-12 months apart in girls and boys aged 9-14 years compared to women aged 16-26 years after three doses support the 2-dose schedule for adolescents of this age group. In clinical trials 9vHPV vaccine was well-tolerated with a similar safety profile to 4vHPV vaccine. The switch to 9vHPV vaccine and a 2-dose schedule is anticipated to improve public acceptability of the program and reduce HPV-related disease in the long-term.

Exposure to Endocrine-Disrupting Chemicals During Pregnancy Is Associated with Weight Change Through 1 Year Postpartum Among Women in the Early-Life Exposure in Mexico to Environmental Toxicants Project

Background: The postpartum period may be a vulnerable life stage for a woman's cardiometabolic health. We examined associations of exposure to common endocrine-disrupting chemicals (EDCs) during pregnancy with weight from delivery through 1 year postpartum among 199 women in Mexico City. Materials and Methods: During each trimester of pregnancy, we collected a urine sample to assay bisphenol A (BPA), mono-n-butyl phthalate (MnBP), mono-isobutyl phthalate (MiBP), monobenzyl phthalate (MBzP), mono-3-carboxypropyl phthalate (MCPP), mono-2-ethyl-5-carboxypentyl phthalate (MECPP), mono-2-ethyl-5-hydroxyhexyl phthalate (MEHHP), mono-2-ethylhexyl phthalate (MEHP), mono-2-ethyl-5-oxohexyl phthalate (MEOHP), and monoethyl phthalate (MEP). We calculated summary scores for di-2-ethylhexyl phthalate metabolites (ΣDEHP) and dibutyl phthalate metabolites (ΣDBP). We calculated the geometric mean of each EDC across pregnancy for use in the analysis. At delivery and three additional times during the first year postpartum, we measured the women's weight. We used mixed-effects linear regression models to estimate associations of each EDC with weight at delivery (kg) and weight change (kg/year) from delivery through 1 year postpartum. Covariates included urinary specific gravity, maternal age, parity, height, first trimester body mass index, and gestational age at enrollment. Results: Mean ± standard deviation weight change during the first postpartum year was -0.49 ± 4.04 kg. The EDCs were inversely associated with weight at delivery, but positively associated with weight change through 1 year postpartum. For example, each interquartile range of urinary ΣDEHP corresponded with 1.38 (95% confidence interval: 0.44-2.33) kg lower weight at delivery and 1.01 (0.41--1.61) kg/year slower rate of weight loss. We observed similar associations for other EDCs. Conclusions: Prenatal exposure to EDCs is associated with lower weight at delivery, but slower rate of weight loss through the first postpartum year.

Health resource utilization of labor induction versus expectant management

BACKGROUND

Although induction of labor of low-risk nulliparous women at 39 weeks reduces the risk of cesarean delivery compared with expectant management, concern regarding more frequent use of labor induction remains, given that this intervention historically has been thought to incur greater resource utilization.

OBJECTIVE

The objective of the study was to determine whether planned elective labor induction at 39 weeks among low-risk nulliparous women, compared with expectant management, was associated with differences in health care resource utilization from the time of randomization through 8 weeks postpartum.

STUDY DESIGN

This is a planned secondary analysis of a multicenter randomized trial in which low-risk nulliparous women were assigned to induction of labor at 39 weeks or expectant management. We assessed resource utilization after randomization in 3 time periods: antepartum, delivery admission, and discharge through 8 weeks postpartum.

RESULTS

Of 6096 women with data available, those in the induction of labor group (n = 3059) were significantly less likely in the antepartum period after randomization to have at least 1 ambulatory visit for routine prenatal care (32.4% vs 68.4%), unanticipated care (0.5% vs 2.6%), or urgent care (16.2% vs 44.3%), or at least 1 antepartum hospitalization (0.8% vs 2.2%, P < .001 for all). They also had fewer tests (eg, sonograms, blood tests) and treatments (eg, antibiotics, intravenous hydration) prior to delivery. During the delivery admission, women in the induction of labor group spent a longer time in labor and delivery (median, 0.83 vs 0.57 days), but both women (P = .002) and their neonates (P < .001) had shorter postpartum stays. Women and neonates in both groups had similar frequencies of postpartum urgent care and hospital readmissions (P > .05 for all).

CONCLUSION

Women randomized to induction of labor had longer durations in labor and delivery but significantly fewer antepartum visits, tests, and treatments and shorter maternal and neonatal hospital durations after delivery. These results demonstrate that the health outcome advantages associated with induction of labor are gained without incurring uniformly greater health care resource use.

Long-term tracking demonstrates effectiveness of a partnership-led training program to advance the careers of biomedical researchers from underrepresented groups

The demographic profile of the biomedical workforce in the U.S. does not reflect the population at large, raising concerns that there will be insufficient trained researchers in the future, and the scope of research interests will not be sufficiently broad. To diversify and expand the pool of researchers trained to conduct research on cancer and cancer health disparities, a series of training activities to recruit and train primarily Hispanic students at both the undergraduate and graduate level were developed. The strengths of both a Hispanic Serving Institution and an NIH-designated Comprehensive Cancer Center were leveraged to develop appropriate research training and professional development activities. The career progression of the participants and degree completion rates was tracked, along with persistent interest in biomedical research in general and cancer and cancer health disparities research in particular for these underrepresented individuals. Finally, this report demonstrates that these training activities increased general knowledge about cancer among participants.

A SHORT TEACHING RESIDENCY SPANNING 1,657 MILES

In scientific disciplines, most postdoctoral fellowships focus on research training. Postdoctoral fellows ("postdocs") develop research expertise and research projects that they will use in future independent faculty positions. This research focus often precludes opportunities for undergraduate teaching. However, most academic faculty positions require faculty to teach at the undergraduate level. The result is that many postdocs are exceptionally well-qualified to meet the research expectations of future faculty positions, but lack experience and training in innovative and evidence-based undergraduate teaching strategies. Training in evidence-based teaching approaches can result in two tangible outcomes. First, the quality of applications by the postdocs for tenure-track faculty positions at institutions with substantive teaching expectations can be improved. Second, we can anticipate stronger alignment of teaching and learning expectations between new faculty and their undergraduate students. There are many programs that provide training in teaching to early career researchers. We describe the design and implementation of a mentored teaching experience that faced some unique challenges, including a large geographic distance between the postdocs and the teaching mentor and teaching site. We describe how we addressed the challenges, what the benefits to various stakeholders have been, and the key elements that contributed to the success of the program.

Socio-demographic predictors of prepulse inhibition: A prospective study in children and adolescents from Mexico City

Prepulse inhibition (PPI) is a sensorimotor gating mechanism that reduces interfering influences to the neural processing of incoming stimuli, and is associated with several neurodevelopmental disorders. To date, research on PPI and neurodevelopmental disorders has primarily been in cross-sectional, clinical settings. In this prospective, epidemiologic study, we used a data-driven prediction model to identify socio-demographic predictors of PPI in children and adolescents from Mexico City to inform future etiologic studies evaluating PPI. We conducted variable selection and validation using a modified version of the multiple imputation random lasso (MIRL) variable selection algorithm. MIRL identified six predictors of PPI at a stimulus onset asynchrony of 120 ms or 240 ms. Of those six predictors, maternal education, birthweight, and total breastfeeding months were highlighted as previously unstudied variables associated with enhanced PPI. Our findings highlight the potential value of PPI as an adjunct screening tool for identifying children at risk for neurodevelopmental disorders and underscore the relevance for validation research on this topic.

HPV vaccination coverage and course completion rates for Indigenous Australian adolescents, 2015

OBJECTIVE

To estimate human papillomavirus (HPV) vaccination coverage and course completion rates for Indigenous adolescents in four Australian states and territories.

PARTICIPANTS, SETTING

Adolescents who were 12 years old in 2015 and received the quadrivalent HPV vaccine (three doses: 0, 2, 6 months) as part of the National HPV Vaccination Program in 2015 or 2016 in New South Wales, Queensland, the Northern Territory, or the Australian Capital Territory.

MAIN OUTCOME MEASURES

Estimated HPV vaccination coverage by dose and by Indigenous status and sex, based on National HPV Vaccination Program Register data; vaccination course completion rates (proportion of dose 1 recipients who received dose 3) for 12-year-olds vaccinated during 2013-2016, by sex, jurisdiction, and Indigenous status.

RESULTS

Dose 1 coverage exceeded 80% for all Indigenous status/jurisdiction/sex groups (range, 83.3-97.7%). Coverage was similar for Indigenous and non-Indigenous girls in Queensland (87.3% v 87.0%), lower for Indigenous girls in the ACT (88.7% v 97.7%) and the NT (91.1% v 97.0%), and higher in NSW (95.9% v 89.9%); it was similar for Indigenous and non-Indigenous boys in all jurisdictions except the NT (88.6% v 96.3%). Dose 3 coverage (range, 61.2-87.7%) was markedly lower for Indigenous than non-Indigenous 12-year-olds in all jurisdictions, except for girls in NSW (82.6% v 83.6%).

CONCLUSION

HPV vaccine coverage is high, but course completion is generally lower for Indigenous adolescents. Strategies for improving completion rates for Indigenous Australians are needed to end the higher burden of cervical cancer among Indigenous than non-Indigenous women.

Adolescent Beverage Intake in Relation to Actigraphy-assessed Sleep Duration, Timing, and Fragmentation (P18-100-19)

Objectives

To examine whether usual beverage intake was associated with sleep timing, duration, and fragmentation among adolescents.

Methods

The study population included 528 Mexico City adolescents enrolled in a longitudinal study. Beverage intake over the last week was assessed with a food frequency questionnaire. The following beverage groups were analyzed: milk, sweetened milk, regular soda, coffee/tea, 100% fruit juice, commercial fruit juice with sugar, fruit drink/flavored water with sugar, and plain water. Sleep timing, duration, and fragmentation were assessed with 7-day actigraphy. Overall and sex-stratified linear regression was conducted with sleep characteristics as separate outcomes and quantiles of energy-adjusted beverage intake as exposures, accounting for sex, age, maternal education, physical activity, and smoking.

Results

The mean age (SD) was 14.4 (2.1) years; 48% were male. The most commonly consumed drinks were water, milk, soda, and fruit juice with added sugar (energy-adjusted mean = 666 (557) mL per day, 360 (278) mL per day, 225 (251) mL per day and 203 (263) mL per day, respectively). In overall regression analysis, soda was associated with later sleep timing; those in the 4th (highest) quartile of soda consumption had a 19 minute later weekday sleep timing than those in the lowest quartile [95% CI 1, 37]. Among boys, milk and water consumption were each associated with longer weekday sleep duration (25 [1, 48] and 26 [4, 47] more minutes, respectively in the 4th compared to the 1st quartile); and higher 100% fruit juice consumption was related to earlier weekday sleep timing (−22 [−28, 1] minutes in the 1st compared to the last quantile; P trend = 0.03). Among girls, soda was associated with higher sleep fragmentation (1.6 [0.4, 2.8] % in the 4th compared to the 1st), and coffee/tea consumption was related to shorter weekend sleep duration (−23 [−44, −2] minutes in the 4th compared to the 1st).

Conclusions

Higher soda intake was associated with later sleep midpoint in boys and girls, while other beverages were associated with sleep in a sex-specific manner. Among girls, adverse associations with sleep were observed for caffeinated drinks only, while boys with higher consumption of water, milk, and natural juice had evidence of healthier sleep.

Funding Sources

NIH/NIEHS, EPA.

Comparison of Actual and Reported Macronutrient Intake in a Well-controlled Human Feeding Study (P08-003-19)

Objectives

Dietary guidelines are largely based on epidemiological studies that rely on memory-based dietary assessments (MBDAs) such as 24-hour recalls (24 hr). Few reports have compared actual and reported dietary intake in well-controlled feeding studies (WCFS). This study sought to directly compare discrepancies between actual dietary intake from experimental diets and reported 24 hr intake in free-living participants.

Methods

Food was provided to 24 subjects (50% female, ages 24.4(3.4); BMI 23.1(2.9)) for 24 days; all diets were eucaloric. Participants were provided a standard diet (15% protein (PRO): 35% fat: 50% carbohydrate (CHO)) for 3 days and then randomly assigned to either a 21-day high fat (60% fat, HF) or a high CHO (75% CHO, HC) diet while PRO was held constant. Diets were ‘typical’ foods with macronutrient compositions adjusted to achieve targeted percentages, either overtly (added sugary drinks) or covertly (added coconut oil). Calories were added to maintain weight (±1 kg). Dietitians administered 4 24-hour recalls (24 hr); one after the standard diet, and once a week during the experimental diets. Actual and reported energy intake (EI) and macronutrient intakes were compared within group via Student's T-tests (α = 0.05).

Results

No difference was observed between actual EI and reported EI during the standard or experimental phase for HF or HC groups. %difference was calculated as (g reported/g actual) * 100. PRO intake was over-reported by all subjects during the standard phase – 127.4% (11.3) and during the HC – 115.6% (7.2) and HF – 116.1% (5.6). PRO difference was due to over-reporting of animal PRO. During the experimental diet, HC subjects over-reported CHO – 166.4% (11.4) and under-reported fat –93.7% (4.7) while HF subjects under-reported CHO – 89.2% (6.5) and over-reported fat –119.8 (6.7). (P < 0.05).

Conclusions

In this WCFS in free-living participants, EI is accurately reported. However, subjects over-report animal PRO intake potentially due to their misreporting portion sizes of meat. When given extreme diets, subjects tended to under report the experimental macronutrient (HF or HC). This could potentially be due to covert target macronutrients in the diet. This makes use of the 24hr suspect in WCFS when macronutrients are hidden from participants.

Funding Sources

This study was internally funded through researchers discretionary funds.

Supporting Tables, Images and/or Graphs

Intrinsic Mitochondrial Nutrient Utilization May Underlie the Association of Metabolite Levels with BMIz and Insulin Resistance (FS03-02-19)

Objectives

To identify metabolites associated with BMIz and insulin resistance (IR) among 108 girls and 98 boys aged 8–14 years. We sought evidence of whether altered mitochondrial nutrient utilization, as indicated by mitochondrial-derived metabolites, mediates the relationship between diet, IR and obesity.

Methods

Anthropometry, fasting untargeted-liquid chromatography/mass spectrometry-derived metabolites and C-Peptide, and semi-quantitative food frequency questionnaires were collected from adolescents in the Early Life Exposure in Mexico to ENvironmental Toxicants (ELEMENT) birth cohort. Sex-stratified generalized linear models were used to identify metabolites that are marginally associated BMIz and HOMA C-peptide (HOMA-CP), accounting for puberty, age and muscle and fat area (FDR < 0.1). Assessed the relationship between energy-adjusted macronutrient intake with HOMA-CP and BMIz. Structural equation models coupled with hierarchical clustering identified clusters of metabolites that may mediate the relationship between macronutrient intake with BMIz and HOMA-CP.

Results

Stratification by sex demonstrated sex-specific associations with BMIz. Most notable were girl's positive association with diacylglycerols and boy's positive association with branched chain and aromatic amino acids, independent of HOMA-CP. Intermediates in fatty acid metabolism, including medium chain acylcarnitines (acylCN), were inversely associated with HOMA-CP. No direct relationship was observed between macronutrient intake with BMIz and IR. Using mediation analyses, fat intake is positively associated with BMIz and HOMA-CP through increases in levels of dicarboxylic fatty acids (DiC-FA), products of omega-oxidation. Carbohydrate intake is positively associated with HOMA-CP through decreases in levels of medium chain acylCN, products of β-oxidation.

Conclusions

Insulin resistance in children appears to be associated with reduced fatty acid oxidation capacity. When consuming more grams of fat, there is evidence for increased extra-mitochondrial fatty acid metabolism (DiC-FA), while higher carbohydrate intake appears to lead to accumulation of intermediates of β-oxidation. Thus, biomarkers of IR and mitochondrial oxidative capacity may depend on macronutrient intake.

Funding Sources

This work was supported by the NIEHS, EPA and NIDDK.

The Association Between Breastfeeding and Body Composition During Adolescence (P11-123-19)

Objectives

To investigate whether breastfeeding duration during infancy was related to body composition in adolescence.

Methods

The analytic sample comprised 536 Mexico City adolescents enrolled in an ongoing cohort study. Breastfeeding duration was estimated based on mother's report of when she started and stopped breastfeeding, assessed during follow up visits at 1, 3, 6, and 12 months postpartum. Trained health professionals conducted the anthropometric assessment of weight, height, waist circumference, and triceps, suprailiac, and subscapular skinfold thicknesses. Bioelectrical impedance was used to derive the fat, muscle, lean and trunk fat masses and percentages. Sex-specific linear regression was performed with body composition measures as outcomes and breastfeeding duration in months as a continuous exposure, accounting for age, maternal education, maternal smoking during pregnancy, maternal parity, birth weight, and length, length of gestation, and adolescent maturation status.

Results

The median (IQR) age was 14.62 (3.90) years, and 51.49% were females. Mean (SD) Body Mass Index Z-score was 0.58 (1.19) for females and 0.42 (1.29) for males. Breastfeeding duration ranged from 0 to 34 months with a median duration of 6.50 (9.00) and 7.00 (8.00) months in females and males, respectively. In males, there was a statistically significant positive association between duration of breastfeeding and skeletal muscle and lean mass in crude models (β = 0.19 [95% CI 0.07, 0.30] and β = 0.29 [95% CI 0.11, 0.46], respectively. Nonetheless, these associations were attenuated and no longer statistically significant when age and other covariates were included in the linear model (for muscle mass β = 0.02 [95% CI - 0.06, 0.10]) and lean mass β = 0.03 [95% CI - 0.09, 0.15]). There were no associations between breastfeeding duration and other body composition outcomes either in crude or adjusted sex-specific models.

Conclusions

After accounting for potential confounders, there was no evidence of a relationship between breastfeeding duration and adolescent body composition. Age was a crucial confounder, as younger adolescents in the cohort had shorter breastfeeding duration and lower skeletal and lean mass.

Funding Sources

NIH/NIEHS and EPA.

Familial psychosocial risk classes and preschooler body mass index: The moderating effect of caregiver feeding style

BACKGROUND

Early child weight gain predicts adolescent and adult obesity, underscoring the need to determine early risk factors affecting weight status and how risk factors might be mitigated. Socioeconomic status, food insecurity, caregiver depressive symptomology, single parenthood, and dysfunctional parenting each have been linked to early childhood weight status. However, the associations between these risk factors and children's weight status may be moderated by caregiver feeding styles (CFS). Examining modifiable factors buffering risk could provide key information to guide early obesity intervention efforts.

METHODS

This analysis used baseline data from the Growing Healthy project that recruited caregivers/child dyads (N = 626) from Michigan Head Start programs. Caregivers were primarily non-Hispanic white (62%) and African American (30%). After using latent class analysis to identify classes of familial psychosocial risk, CFS was tested as a moderator of the association between familial psychosocial risk class and child body mass index (BMI) z-score.

RESULTS

Latent class analysis identified three familial psychosocial risk classes: (1) poor, food insecure and depressed families; (2) poor, single parent families; and (3) low risk families. Interactive effects for uninvolved feeding styles and risk group indicated that children in poor, food insecure, and depressed families had higher BMI z-scores compared to children in the low risk group. Authoritative feeding styles in low risk and poor, food insecure, and depressed families showed lower child BMI z-scores relative to poor, single parent families with authoritative feeding styles.

CONCLUSIONS

Uninvolved feeding styles intensified the risk and an authoritative feeding style muted the risk conferred by living in a poor, food-insecure, and depressed family. Interventions that promote responsive feeding practices could help decrease the associations of familial psychosocial risks with early child weight outcomes.

Trends in diagnoses after implementation of the Chicago classification for esophageal motility disorders (V3.0) for high-resolution manometry studies

To determine trends in the diagnostic distribution of esophageal motility disorders after implementation of the Chicago Classification Version 3.0 (CC V3.0) for interpretation of high-resolution manometry (HRM) studies compared to non-Chicago Classification criteria. Retrospective trends analysis of patients with an HRM study conducted at a single center from January 1, 2013 to September 30, 2015. The implementation of the CC V3.0 for manometry interpretation occurred in September 2014. Patient charts were manually reviewed for data collection including demographics and HRM diagnoses. The prevalence and relative risks (RR) of CC V3.0 diagnostic categories (i.e. normal, indeterminate, achalasia, and EGJ outflow obstruction [EJGOO], and major and minor motility disorders) were calculated before and after CC V3.0 implementation. Four hundred sixty-five HRM studies were included in the study including 268 before and 179 after CC V3.0 implementation. The mean ± SD age was 54 ± 15.4 years and 59.8% were female (n = 278). The percentage with indeterminate diagnosis decreased from 35.3% before CC V3.0 implementation to 16.8% after implementation (adjusted RR 0.5, 95%CI 0.30-0.70, p < 0.001). The percentage with a major motility disorders decreased from 13.9% to 7.3% (adjusted RR 0.5, 95%CI 0.2-1.0, p < 0.001). The percentage with EJGOO and minor diagnoses increased from 1.4% to 14.5% and 11.9% to 22.9%, respectively. The percentage with achalasia and normal diagnosis did not change over the study period. Implementation of CCV3.0 was associated with changes in the distribution of esophageal motility diagnoses in clinical practice. The percentage of indeterminate and major diagnosis decreased and EGJOO and minor diagnoses increased. The decrease in the number of indeterminate studies suggests that the CC V3.0 may clarify the criteria for the interpreting physician. The increase in studies with a diagnosis of EGJ outflow obstruction may reflect the heterogeneity of disorders with clinically relevant outflow obstruction.

Urinary and plasma fluoride levels in pregnant women from Mexico City

BACKGROUND

There is need to assess the developmental neurotoxicity of fluoride. Our knowledge of prenatal fluoride exposure is challenged as few population-based studies have been conducted and these generally date back several decades, provide incomplete data on sociodemographic variables, and have methodological limitations.

OBJECTIVE

To measure urinary and plasma fluoride levels across three time points in pregnant mothers who were enrolled in the Early Life Exposures in Mexico to Environmental Toxicants (ELEMENT) birth cohort study.

METHODS

Fluoride levels were characterized in archived urine and plasma from 872 pregnant mothers sampled from the ELEMENT cohort. Various statistical methods were used to analyze the fluoride data with particular consideration for changes across three stages of pregnancy and against sociodemographic variables.

RESULTS

All samples had detectable levels of fluoride. The mean urinary and plasma fluoride levels were 0.91 and 0.0221mg/L respectively, and these were not statistically different across three stages of pregnancy. Fluoride levels correlated across the stages of pregnancy studied, with stronger correlations between neighboring stages. Urinary fluoride changed as pregnancy progressed with levels increasing until ~23 weeks and then decreasing until the end of pregnancy. For plasma fluoride, there was a decreasing trend but this was not of statistical significance. Creatinine-adjusted urinary fluoride levels did not associate consistently with any of the sociodemographic variables studied.

CONCLUSIONS

This study provides the most extensive characterization to date of fluoride exposure throughout pregnancy. These results provide the foundation to explore exposure-related health outcomes in the ELEMENT cohort and other studies.

Effects of Compression Hosiery in Female Workers with a Standing Profession

Objective:

To evaluate the effect of compression hosiery during standing work.

Design:

An open study, comparing symptoms and plethysmographic findings before and after treatment.

Setting:

University hospital, vascular surgery.

Subjects:

Forty-eight female volunteers with a standing profession.

Methods:

Visual analogue scale to evaluate symptoms and foot volumetry to study venous function before and after 4 weeks use of compression hosiery (20–30 mmHg).

Result:

All scores for symptoms were significantly reduced after treatment. Only 21% of the study subjects had minor abnormalities on foot volumetry. The expelled volume was significantly higher after work at 4 weeks than at the first measurement at inclusion, while the refilling rate was significantly lower after work at 4 weeks than at the corresponding measurement at inclusion.

Conclusion:

Symptomatic improvement was recorded after compression treatment. Limited effects were seen with the objective measurement, although the most important factor, the refilling rate, diminished significantly during the treatment period. Compression treatment reduces lower limb symptoms following standing work.

Early introduction and cumulative consumption of sugar-sweetened beverages during the pre-school period and risk of obesity at 8-14 years of age

BACKGROUND

Consumption of sugar-sweetened beverages (SSB) has been associated with risk of obesity, but little evidence exists to evaluate if age of introduction and cumulative SSB consumption increases risk in children.

OBJECTIVES

The objective of the study was to estimate the relationship between age of introduction and cumulative SSB consumption with risk of obesity in 227 Mexican children.

METHODS

SSB intake was measured every 6 months; age of introduction and cumulative consumption during the pre-school period were calculated. Height, weight, waist circumference, SSB intake and other relevant variables were measured at age 8-14 years and obesity defined using standard criteria.

RESULTS

All participants were introduced to SSB before age 24 months and most (73%) before 12 months. Early SSB introduction (≤12 months) was not significantly associated with increased odds of obesity (odds ratio [OR] = 2.00, 95% confidence interval [CI]: 0.87, 4.59). However, children in the highest tertile of cumulative SSB consumption, compared with the lowest, had almost three times the odds of general (OR = 2.99, 95% CI: 1.27, 7.00) and abdominal (OR = 2.70, 95% CI: 1.03, 7.03) obesity at age 8-14 years.

CONCLUSIONS

High SSB consumption increased the likelihood of obesity in 8-14-year-old children. Our results suggest that SSB intake should be delayed and excessive SSB consumption in pre-school period should be avoided.

A multi-method review of home-based chemotherapy

This study summarises research- and practice-based evidence on home-based chemotherapy, and explores existing delivery models. A three-pronged investigation was conducted consisting of a literature review and synthesis of 54 papers, a review of seven home-based chemotherapy programmes spanning four countries, and two case studies within the Canadian province of Ontario. The results support the provision of home-based chemotherapy as a safe and patient-centred alternative to hospital- and outpatient-based service. This paper consolidates information on home-based chemotherapy programmes including services and drugs offered, patient eligibility criteria, patient views and experiences, delivery structures and processes, and common challenges. Fourteen recommendations are also provided for improving the delivery of chemotherapy in patients' homes by prioritising patient-centredness, provider training and teamwork, safety and quality of care, and programme management. The results of this study can be used to inform the development of an evidence-informed model for the delivery of chemotherapy and related care, such as symptom management, in patients' homes.

Mercury levels in pregnant women, children, and seafood from Mexico City

BACKGROUND

Mercury is a global contaminant of concern though little is known about exposures in México.

OBJECTIVES

To characterize mercury levels in pregnant women, children, and commonly consumed seafood samples.

METHODS

Use resources of the Early Life Exposures in Mexico to Environmental Toxicants (ELEMENT) birth cohorts to measure total mercury levels in archived samples from 348 pregnant women (blood from three trimesters and cord blood), 825 offspring (blood, hair, and urine) and their mothers (hair), and 91 seafood and canned tuna samples from Mexico City.

RESULTS

Maternal blood mercury levels correlated across three trimesters and averaged 3.4 μg/L. Cord blood mercury averaged 4.7 μg/L and correlated with maternal blood from trimester 3 (but not trimesters 1 and 2). In children, blood, hair and urine mercury levels correlated and averaged 1.8 μg/L, 0.6 μg/g, and 0.9 μg/L, respectively. Hair mercury was 0.5 μg/g in mothers and correlated with child's hair. Mean consumption of canned tuna, fresh fish, canned sardine, and shellfish was 3.1, 2.2, 0.5, and 1.0 times per month respectively in pregnant women. Mean mercury content in 7 of 23 seafood species and 5 of 9 canned tuna brands purchased exceeded the U.S. EPA guidance value of 0.3 μg/g.

CONCLUSIONS

Mercury exposures in pregnant women and children from Mexico City, via biomarker studies, are generally 3-5 times greater than values reported in population surveys from the U.S., Canada, and elsewhere. In particular, mercury levels in 29-39% of the maternal participants exceeded the biomonitoring guideline associated with the U.S. EPA reference dose for mercury.

RETRACTED: Paraoxonase I polymorphisms and attention/hyperactivity in school-age children from Mexico City, Mexico

Globally, organophosphate (OP) pesticide usage and exposure is widespread. Studies have found that fetuses and infants are more sensitive than adults to environmental toxicants and that prenatal exposure to low levels of OPs has been associated with Attention Deficit Hyperactivity Disorder-Like Phenotypes (ADHD-LP). Paraoxonase 1 (PON1) is an enzyme involved in detoxifying some OPs and its polymorphisms influence enzyme activity and quantity. The objective of this study was to examine whether maternal and/or child PON1 genotypes (PON1R192Q and PON1L55M) were associated with ADHD-LP in a Mexico City, Mexico birth cohort. PON1R192Q and PON1L55M genotypes in mothers (PON1R192Q: N=531; PON1L55M: N=458) and children (PON1R192Q: N=532; PON1L55M: N=478) from blood DNA were determined. We assessed ADHD-LP for children between the ages of 6 and 13 using Conners' Parent Rating Scales-Revised (CRS-R), Conners' Continuous Performance Test (CPT), and the parent scores for Behavior Assessment System for Children-2 (BASC2). Multivariable linear regression models were used to test relationships between ADHD-LP and PON1 polymorphisms. In these models, significant associations were observed with maternal genotypes but not with the child genotypes. A higher DSM IV Hyperactivity/Impulsivity score (β=3.27 points; 95% CI (0.89, 5.65)) and a 2.17 higher score in child DSM IV Total (95% CI (0.05, 4.29)) were observed for maternal PON155MM in comparison to PON155LM+LL. The childattention problems score was 2.27 points higher (95% CI (0.002, 4.53) for maternal PON1192QQ in comparison to PON1192QR+RR. Because maternal PON1 polymorphisms were associated with child ADHD-LP, this may be a viable biomarker of susceptibility for ADHD-LP.

Examining waiting placement in hospital: utilization and the lived experience

This mixed-methods study addressed the problem that although waiting placement is considered a major hospital utilization issue, minimal evidence exists to highlight the extent of it and the personal impact of waiting placement. An analysis of two years of complete hospital data for the Canadian province of Alberta was undertaken to examine waiting placement rates and describe waiting placement patients. Qualitative interviews and observations of elderly patients waiting in hospital for nursing home placement were also undertaken to gain an understanding of the lived experience of waiting for placement in hospital. Only 1.8% of all inpatients were waiting placement with an ALC (Alternative Level of Care) designation, 80% of ALC waits were less than 41 days (mean=29.85, median=14), and 2.2% of total hospital bed days in these two years were used by ALC patients. Three qualitative themes emerged: (a) coming to a realization of this significant move, (b) waiting is boring and distressing, and (c) hospitals are not designed for waiting placement. The findings of this study should raise awareness that although relatively few people wait placement in hospital, there are some major possible negative effects of waiting for placement in hospital for those who wait; with remedies to address waiting placement care deficits needed.

An exercise program to prevent falls in institutionalized elderly with cognitive deficits: a crossover pilot study

Falls are the leading cause of injury among older adults in the United States, with the institutionalized elderly at elevated risk for injury and death. Physical weakness and mental frailty, prevalent in institutionalized elderly, are major risk factors for falls. The purpose of this study was to evaluate a program that addresses both the physical and mental aspects of exercise to reduce falls in institutionalized elderly. Twenty-seven volunteer subjects residing in an assisted living facility participated in the 24 week randomized crossover study. After demographic, fall history, and mental status examinations, subjects were randomly assigned first to ten weeks of either an exercise class or a control group, followed by a four week "washout period" of no activity, then cross assigned to ten weeks as either a control group or exercise class, respectively. Falls as well as mental status changes were monitored during the study. After adjusting for differences in baseline risk between the control and treatment groups, and for potential residual effects of the treatment during the crossover phase, a statistically significant (P = .025) reduction in falls was found during treatment compared to the control periods. No change in mental status was seen. This small, pilot study shows that exercise programs, which emphasize mental strengthening as well as physical fitness, have the potential to reduce falls among mentally impaired, institutionalized seniors.