A novel preclinical model of environment-like combined benzene, toluene, ethylbenzene, and xylenes (BTEX) exposure: Behavioral and neurochemical findings.

Environmental exposure to toxicants is a major health issue and a leading risk factor for premature mortality worldwide, including environmental exposures to volatile organic compounds (VOCs), specifically Benzene, Toluene, Ethylbenzene, and Xylene (BTEX). While exposure to these compounds individually has shown behavioral and neurochemical effects, this investigation examined the impact of exposure to combined BTEX using a preclinical model. Male Swiss Webster mice were exposed to BTEX vapors designed to approximate environmental levels in urban communities. Animals were exposed to one of four treatment conditions: a 0-ppm (air control), two BTEX groups representing levels of environmental-like exposure, and a fourth group modeling occupational-like exposure. These exposures were conducted in 1.5-h sessions, 2 sessions/day, 5 days/week, for 3 weeks. Effects on coordination (i.e., rotarod and inverted screen test), learning and memory (i.e., Y-maze), and locomotor behavior (i.e., movement during exposure) were assessed during and after exposure. Monoamine levels in the medial prefrontal cortex and nucleus accumbens were assessed immediately following exposure. Effects of BTEX exposure were found on the variance of locomotor activity but not in other behavioral or neurochemical assessments. These results indicate that the combination of inhaled BTEX at environmentally representative concentrations has demonstrable, albeit subtle, effects on behavior.

Effects of inhaled combined Benzene, Toluene, Ethylbenzene, and Xylenes (BTEX): Toward an environmental exposure model.

Combined environmental exposures to the volatile organic compounds (VOCs) Benzene, Toluene, Ethylbenzene, and Xylene (BTEX) pose clear risks to public health. Research into these risks is under-studied even as BTEX levels in the atmosphere are predicted to rise. This review focuses on the available literature using single- and combined-BTEX component inhaled solvent exposures in animal models, necessarily also drawing on findings from models of inhalant abuse and occupational exposures. Health effects of these exposures are discussed for multiple organ systems, but with particular attention on neurobehavioral outcomes such as locomotor activity, impulsivity, learning, and psychopharmacological responses. It is clear that animal models have significant differences in the concentrations, durations and patterns of exposure. Experimental evidence of the deleterious health and neurobehavioral consequences of exposures to the individual components of BTEX were found, but these effects were typically assessed using concentrations and exposure patterns not characteristic of environmental exposure. Future studies with animal models designed appropriately to explore combined BTEX will be necessary and advantageous to discovering health outcomes and more subtle neurobehavioral impacts of long-term environmental exposures.

Prenatal Alcohol Screening During Pregnancy by Midwives and Nurses.

BACKGROUND: Alcohol use during pregnancy can have a variety of harmful consequences on the fetus. Lifelong effects include growth restriction, characteristic facial anomalies, and neurobehavioral dysfunction. This range of effects is known as fetal alcohol spectrum disorders (FASD). There is no amount, pattern, or timing of alcohol use during pregnancy proven safe for a developing embryo or fetus. Therefore, it is important to screen patients for alcohol use, inform them about alcohol's potential effects during pregnancy, encourage abstinence, and refer for intervention if necessary. However, how and how often nurses and midwives inquire about alcohol drinking during pregnancy or use recommended screening tools and barriers they perceive to alcohol screening has not been well established. METHODS: This survey was sent to about 6,000 American midwives, nurse practitioners, and nurses who provide prenatal care about their knowledge of the effects of prenatal alcohol exposure, the prevalence of alcohol use during pregnancy, and practices for screening patients' alcohol use. Participants were recruited by e-mail from the entire membership roster of the American College of Nurse-Midwives. RESULTS: There were 578 valid surveys returned (about 9.6%). Analyses showed that 37.7% of the respondents believe drinking alcohol is safe during at least one trimester of pregnancy. Only 35.2% of respondents reported screening to assess patient alcohol use. Only 23.3% reported using a specific screening tool, and few of those were validated screens recommended for use in pregnant women. Respondents who believe alcohol is safe at some point in pregnancy were significantly less likely to screen their patients. CONCLUSIONS: Respondents who reported that pregnancy alcohol use is unsafe felt more prepared to educate and intervene with patients regarding alcohol use during pregnancy and FASD than respondents who reported drinking in pregnancy was safe. Perceived alcohol safety and perceived barriers to screening appeared to influence screening practices. Improving prenatal care provider knowledge about the effects of prenatal alcohol exposure and the availability of valid alcohol screening tools will improve detection of drinking during pregnancy, provide more opportunities for meaningful intervention, and ultimately reduce the incidence of FASD.

Increased cut-point of the TACER-3 screen reduces false positives without losing sensitivity in predicting risk alcohol drinking in pregnancy.

BACKGROUND: Detection of in-pregnancy maternal risk alcohol drinking is an essential first step in preventing fetal alcohol spectrum disorders, and the widely used T-ACE screen was developed for that purpose. We recently reported that increasing the total T-ACE score cut-point from 2 to 3 doubled specificity of detecting risk drinking in pregnancy and identified 4-year-old children with neurobehavioral effects associated with prenatal alcohol exposure. METHODS: In this study, the TACER-3 was further validated in another prospectively identified high-risk urban cohort. Women were categorized as follows: (i) Not At-Risk Group (negative on T-ACE and TACER-3); (ii) At-Risk Group (positive on T-ACE and TACER-3); and (iii) Change Risk Group (positive on T-ACE but negative on TACER-3). RESULTS: The TACER-3 total score cut-point of 3 yielded fewer "false positives" than the T-ACE cut-point of 2. Based on relative risk scores, women in the TACER-3-positive At-Risk Group were more likely to drink alcohol during pregnancy than women in the Change Risk Group. In contrast, women in the Not At-Risk Group were largely not different in their drinking from women in the Change Risk Group. The largest increases in relative risk of the At-Risk Group compared to the Change Risk Group were for the amount of drinking per day across pregnancy (RR = 11.4) and for the amount of drinking per drinking day at the first prenatal visit (RR = 12.7). For both of these measures, the relative risk of at-risk alcohol consumption in the At-Risk Group was over >10 times that of the Change Risk Group. CONCLUSIONS: Thus, the TACER-3 was more effective at selectively identifying women drinking at fetal risk levels than the original T-ACE. The TACER-3 allows for more efficient use of healthcare provider time in directing targeted clinical interventions with pregnant women identified as drinking at fetal risk levels.

Just say "I don't": lack of concordance between teen report and biological measures of drug use.

BACKGROUND: Prevalence estimates of illicit drug use by teens are typically generated from confidential or anonymous self-report. While data comparing teen self-report with biological measures are limited, adult studies identify varying degrees of under-reporting. METHODS: Hair analyses for cocaine, opiates and marijuana were compared to confidential teen self- and parent-reported teen drug use in a longitudinal cohort of >400 high-risk urban teens and parents. RESULTS: Both teens and parents substantially underreported recent teen cocaine and opiate use. However, compared with parents, teens were more likely to deny biomarker-verified cocaine use. Teen specimens (hair) were 52 times more likely to identify cocaine use compared with self-report. Parent hair analyses for cocaine and opiate use were 6.5 times and 5.5 times, respectively, more likely to indicate drug use than were parental self-report. The lack of concordance between self-report and bioassay occurred despite participant's knowledge that a "certificate of confidentiality" protected both teen and adult participants, and that the biological specimens would be tested for drugs. CONCLUSIONS: These findings confirm prior reports of adult under-reporting of their own drug use while extending our understanding of teen's self-admitted drug use. The lack of concordance between teen self- or parent-reported teen drug use and biomarkers confirm our concerns that both teen- and parent-reported teen drug use is limited, at least for youth in high-risk urban settings. Methods of ascertainment other than self- or parent-report must be considered when health care providers, researchers and public health agencies attempt to estimate teen drug-use prevalence.

The impact of maternal age on the effects of prenatal alcohol exposure on attention.

BACKGROUND: Prenatal exposure to alcohol has a variety of morphologic and neurobehavioral consequences, yet more than 10% of women continue to drink during pregnancy, placing their offspring at risk for fetal alcohol spectrum disorders (FASD). Identification of at-risk pregnancies has been difficult, in part, because the presence and severity of FASD are influenced by factors beyond the pattern of alcohol consumption. Establishing maternal characteristics, such as maternal age, that increase the risk of FASD is critical for targeted pregnancy intervention. METHODS: We examined the moderating effect of maternal age on measures of attention in 462 children from a longitudinal cohort born to women with known alcohol consumption levels (absolute ounces of alcohol per day at conception) who were recruited during pregnancy. Analyses examined the impact of binge drinking, as average ounces of absolute alcohol per drinking day. Smoking and use of cocaine, marijuana, and opiates were also assessed. At 7 years of age, the children completed the Continuous Performance Test, and their teachers completed the Achenbach Teacher Report Form. RESULTS: After controlling for covariates, stepwise multiple regression analyses revealed a negative relation between levels of prenatal binge drinking and several measures of attention. The interaction between alcohol consumption and maternal age was also significant, indicating that the impact of maternal binge drinking during pregnancy on attention was greater among children born to older drinking mothers. CONCLUSION: These findings are consistent with previous findings that children born to older alcohol-using women have more deleterious effects of prenatal alcohol exposure on other neurobehavioral outcomes.

Validity of the T-ACE in pregnancy in predicting child outcome and risk drinking.

Preventing fetal alcohol spectrum disorders (FASDs) requires detection of in-pregnancy maternal risk drinking. The widely used T-ACE screen has been applied in various ways, although the impact of those different uses on effectiveness is uncertain. We examined relations among different T-ACE scoring criteria, maternal drinking, and child outcome. Self-reported across-pregnancy maternal drinking was assessed in 75 African-American women. The different T-ACE criteria used varied the level of drinking that defined tolerance (two or three drinks) and the total T-ACE score cut-points (two or three). Receiver operator curves and regression analysis assessed the significance of relations. Increasing the total T-ACE score cut-point to 3 almost doubled specificity in detecting risk drinking whereas maintaining adequate sensitivity, equivalent to that in the original report, and identified substantially more neurobehavioral deficits in children. Redefining tolerance at three drinks did not improve T-ACE effectiveness in predicting outcomes. This study is among the first to show the ability of an in-pregnancy T-ACE assessment to predict child neurodevelopmental outcome. In addition, increasing the total T-ACE score criterion (from 2 to 3) improved identification of non-drinking mothers and unaffected children with little loss in detection of drinkers and affected children. Efficient in-pregnancy screens for risk drinking afford greater opportunities for intervention that could prevent/limit FASDs.

Maternal smoking is associated with decreased 5-methyltetrahydrofolate in cord plasma.

BACKGROUND: Maternal-fetal folate transport via the placenta has been shown to be concentrative. Exposure to cigarette smoke is associated with decreased maternal folate status through altered dietary intakes and possibly through nondietary mechanisms such as increased folate turnover. The effect of maternal smoking on fetal folate status has not been documented. OBJECTIVE: The objective was to determine the effect of maternal smoking on plasma 5-methyltetrahydrofolic acid (5-MTHFA) concentrations in umbilical cord blood. DESIGN: African American women were recruited from an antenatal clinic in Detroit, MI. Plasma 5-MTHFA concentrations were measured in maternal-umbilical cord pairings (n = 58). The participants completed a structured interview to determine demographic characteristics, including smoking. RESULTS: Concentrations of 5-MTHFA were significantly higher in venous cord plasma (16.8 +/- 7.5 ng/mL) than in maternal plasma (13.0 +/- 7.5 ng/mL) but remained associated (r = 0.60, P < 0.001) with each other. Cigarettes smoked by the mothers was negatively associated (r = -0.31, P = 0.019) with venous cord 5-MTHFA concentrations and remained so after control for maternal plasma 5-MTHFA and other variables. Venous cord plasma 5-MTHFA was significantly lower in smoking (15.1 +/- 7.6 ng/mL; n = 32) than in nonsmoking (19.0 +/- 7.0 ng/mL; n = 26) mothers. CONCLUSIONS: Cord plasma 5-MTHFA concentrations were elevated relative to maternal blood, as expected, because the placenta is capable of concentrative folate transport to the fetus. The negative effect of maternal smoking on infant, but not on maternal, 5-MTHFA status indicates that maternal smoking may impair folate transport to the fetus.

Gender and alcohol moderate caregiver reported child behavior after prenatal cocaine.

OBJECTIVE: The concurrence of prenatal alcohol exposure with other drug exposure, low socioeconomic status and environmental risk factors may obscure associations, if any, between prenatal cocaine exposure and child outcomes. This study evaluates the effects of prenatal cocaine exposure on child behavior in analyses stratified by gender and prenatal alcohol exposure status. METHODS: Maternal alcohol, cigarette, and illicit drug use were prospectively assessed by interview during pregnancy and postnatally. Maternal and neonatal urine were tested for drug exposure as clinically indicated. Caregiver report of child behavior was assessed with the Achenbach Child Behavior Checklist (CBCL). Dichotomous cocaine exposure was characterized as no (negative history and biologic markers), and any (positive history and/or biologic markers during pregnancy and/or positive urine screen at delivery from either mother or infant). RESULTS: Prenatal cocaine exposure was associated with adverse effects on offspring behavior that were moderated by the gender of the offspring as well as prenatal alcohol exposure. For girls without prenatal alcohol exposure, 6.5% of the unique variance in behavior was related to prenatal cocaine exposure. For these girls, the odds of scoring in the abnormal range for Aggression was 17 times control levels (95% confidence limits 1.4 to 203). These findings, though significant, have wide confidence intervals and need to be replicated in larger cohorts and on longitudinal follow-up.

Status of plasma folate after folic acid fortification of the food supply in pregnant African American women and the influences of diet, smoking, and alcohol consumption.

BACKGROUND: African American women and socioeconomically challenged women are at risk of compromised folate status and, thus, of folate-related birth defects. Data are limited on circulating folate concentrations in pregnant African American women after folic acid fortification of the food supply was implemented. OBJECTIVE: The objective was to determine the influence of smoking and alcohol consumption on plasma 5-methyltetrahydrofolic acid (5-MTHFA) concentrations in pregnant African American women. DESIGN: Alcohol consumption, smoking exposure, and other characteristics of pregnant African American women reporting to an inner-city antenatal clinic were assessed. At 24 wk of gestation, blood samples and food-frequency intake data were collected. Plasma 5-MTHFA concentrations were determined by liquid chromatography-mass spectrometry for 116 subjects and examined in a correlational study design. RESULTS: Dietary folate and markers of alcohol consumption were positively associated, whereas exposure to smoke was negatively associated with plasma 5-MTHFA. More than one-half of the participants in this population failed to meet the recommended dietary allowance for dietary folate equivalents of 600 microg/d during pregnancy. CONCLUSIONS: Most inner-city African American women are not meeting the recommended dietary allowance for dietary folate during pregnancy, and smoking may further compromise their folate status. Programs to reduce smoking and raise awareness about the importance of folate and multivitamin supplementation during pregnancy need to target this population.

Effects of alcohol intake during pregnancy on docosahexaenoic acid and arachidonic acid in umbilical cord vessels of black women.

OBJECTIVE: Alcohol influences the intake and metabolism of several nutrients including long-chain polyunsaturated fatty acids (LC-PUFAs). The LC-PUFAs docosahexaenoic acid (DHA) and arachidonic acid (AA) are particularly crucial for intrauterine growth and brain development. We hypothesized that alcohol consumption adversely affects LC-PUFA levels in pregnant women and their newborn infants. METHODS: Pregnant black women (N = 208) presenting at a core city antenatal clinic were screened and recruited. Shortly before delivery, maternal plasma was collected. After delivery, umbilical arteries and veins were dissected from the cords, total lipids were extracted from the vessel tissues and maternal plasma, and fatty acid levels were assayed by gas chromatography. For statistical analysis, subjects were categorized according to absolute alcohol intake per day (AAD) and absolute alcohol intake per drinking day (AADD) around the time of conception, with smoking and other potential confounders included in the analyses. RESULTS: Significant differences in fatty acid composition of total lipid extracts were detected in umbilical cord vessels among the AADD groups: abstainers (AADD = 0), moderate drinkers (AADD < 130 g), and heavy drinkers (AADD > or = 130 g). DHA and AA content in the arterial umbilical vessel wall was approximately 14% and approximately 10% higher in the moderate (n = 127) and heavy (n = 32) alcohol groups, respectively, than in abstainers (n = 49). A small, nonsignificant increase ( approximately 3%) was seen in the umbilical vein for AA but not for DHA. Alcohol intake was positively correlated to both DHA and AA concentrations in the arterial vessel wall but to neither in the venous wall nor maternal plasma. Maternal plasma DHA was positively correlated with both umbilical arteries and vein DHA, but there were no significant correlations for AA between maternal plasma and either umbilical vessel. CONCLUSIONS: Our findings indicate that alcohol intake during pregnancy is associated with altered DHA and AA status in fetal tissues. Although differences may be due to either metabolism and/or distribution, it is most likely a result of a direct influence of alcohol on fetal metabolism.