Dawn M. Bielawski

Combined analysis of prenatal (maternal hair and blood) and neonatal (infant hair, cord blood and meconium) matrices to detect fetal exposure to environmental pesticides

OBJECTIVE The aim of this study was to determine optimum biomarkers to detect fetal exposure to environmental pesticides by the simultaneous analysis of maternal (hair and blood) and infant (cord blood, infant hair or meconium) matrices and to determine if a combination of these biomarkers will further increase the detection rate. PATIENTS AND METHODS Pregnant women were prospectively recruited from an agricultural site in the Philippines with substantial use at home and in the farm of the following pesticides: propoxur, cyfluthrin, chlorpyrifos, cypermethrin, pretilachlor, bioallethrin, malathion, diazinon and transfluthrin. Maternal hair and blood were obtained at midgestation and at delivery and infant hair, cord blood and meconium were obtained after birth. All samples were analyzed by gas chromatography/mass spectrometry (GC/MS) for the above pesticides and some of their metabolites. RESULTS A total of 598 mother/infant dyads were included in this report. The highest rates of pesticide exposure were detected in meconium (23.2% to propoxur, 2.0% to pretilachlor, 1.7% to cypermethrin, 0.8% to cyfluthrin, 0.7% to 1,1,1-trichloro-2,2-bis, p-chlorophenylethane (DDT) and 0.3% to malathion and bioallethrin) and in maternal hair (21.6% to propoxur, 14.5% to bioallethrin, 1.3% to malathion, 0.8% to DDT, 0.3% to chlorpyrifos and 0.2% to pretilachlor). Combined analysis of maternal hair and meconium increased detection rate further to 38.5% for propoxur and to 16.7% for pyrethroids. Pesticide metabolites were rarely found in any of the analyzed matrices. CONCLUSIONS There is significant exposure of the pregnant woman and her fetus to pesticides, particularly to the home pesticides, propoxur and pyrethroids. Analysis of meconium for pesticides was the single most sensitive measure of exposure. However, combined analysis of maternal hair and meconium significantly increased the detection rate. A major advantage of analyzing maternal hair is that prenatal pesticide exposure in the mother can be detected and intervention measures can be initiated to minimize further exposure of the fetus to pesticides.

The social representation of material culture and gender in children's books

This study examined the gender-typed portrayal of material culture in Caldecott Award childrens books published between 1937 and 1989. Analyses of illustrations found that a larger proportion of female characters was shown using household artifacts, and a larger proportion of male characters was depicted using nondomestic production artifacts. Contrast analyses revealed no change over time in the proportions of female characters portrayed using household and production artifacts. Childrens exposure to this representation may result in gender-linked modeling effects on preferences and skills related to technology and other material culture.

Association between prenatal pesticide exposures and the generation of leukemia-associated T(8;21)

This study was designed to investigate the relationship between prenatal pesticide exposures and the generation of leukemia‐associated t(8;21)(q22;q22), one of the most common cytogenetic abnormalities in childhood acute myeloid leukemia (AML).

Fetal exposure to propoxur and abnormal child neurodevelopment at 2 years of age.

OBJECTIVE Our aim was to determine the effects of fetal exposure to propoxur and pyrethroids, on child neurodevelopment at 2 years of age. PATIENTS AND METHODS Mothers were prospectively recruited during mid-pregnancy in Bulacan, Philippines where multiple pesticides including propoxur, cyfluthrin, chlorpyrifos, cypermethrin, pretilachlor, bioallethrin, malathion, diazinon and transfluthrin are used. To detect prenatal exposure to these pesticides, maternal hair and blood, infants hair, cord blood, and meconium were analyzed for the pesticides by gas chromatography/mass spectrometry. Infants were examined at 2 years of age with 95.1% follow up rate and their neurodevelopment outcome was assessed by the Griffiths mental developmental scale (N=754). RESULTS Meconium analysis was the most sensitive method to detect fetal exposure to pesticides and exposure was highest for propoxur (21.3%) and the grouped pyrethroids (2.5% - bioallethrin, transfluthrin, cyfluthrin and cypermethrin). Path analysis modeling was performed to determine the effects of fetal exposure to propoxur and pyrethroids on the childs neurodevelopment at 24 months of age while controlling for confounders. Only singletons and those with complete data for the path analysis were included (N=696). Using a path analysis model, there was a significant negative (β=-0.14, p<0.001) relationship between prenatal pesticide exposure to propoxur and motor development at 2 years of age after controlling for confounders, e.g., infant gender, socioeconomic status, maternal intelligence, home stimulation (HOME), postnatal exposure to propoxur and blood lead level at 2 years of age. CONCLUSION At 2 years of age, prenatal exposure to propoxur was associated with poorer motor development in children.

Effects of Noninvasive Facial Nerve Stimulation in the Dog Middle Cerebral Artery Occlusion Model of Ischemic Stroke

Background and Purpose— Facial nerve stimulation has been proposed as a new treatment of ischemic stroke because autonomic components of the nerve dilate cerebral arteries and increase cerebral blood flow when activated. A noninvasive facial nerve stimulator device based on pulsed magnetic stimulation was tested in a dog middle cerebral artery occlusion model. Methods— We used an ischemic stroke dog model involving injection of autologous blood clot into the internal carotid artery that reliably embolizes to the middle cerebral artery. Thirty minutes after middle cerebral artery occlusion, the geniculate ganglion region of the facial nerve was stimulated for 5 minutes. Brain perfusion was measured using gadolinium-enhanced contrast MRI, and ATP and total phosphate levels were measured using 31P spectroscopy. Separately, a dog model of brain hemorrhage involving puncture of the intracranial internal carotid artery served as an initial examination of facial nerve stimulation safety. Results— Facial nerve stimulation caused a significant improvement in perfusion in the hemisphere affected by ischemic stroke and a reduction in ischemic core volume in comparison to sham stimulation control. The ATP/total phosphate ratio showed a large decrease poststroke in the control group versus a normal level in the stimulation group. The same stimulation administered to dogs with brain hemorrhage did not cause hematoma enlargement. Conclusions— These results support the development and evaluation of a noninvasive facial nerve stimulator device as a treatment of ischemic stroke.

Trends in long term exposure to propoxur and pyrethroids in young children in the Philippines.

BACKGROUND/AIM Pesticides are neurotoxic and can adversely affect childrens neurobehavioral outcome. Ongoing pesticide exposure has to be monitored in the study of long term outcome of pesticide adverse effects since changes in the type and amount of exposure can influence outcome. The aim of this paper is to describe the trend in long term pesticide exposure in children through the analysis of pesticides in their hair. PATIENTS AND METHODS As part of an NIH study on the long term effects of pesticide exposure in young children, ongoing exposure to pesticides was determined by the analysis of childrens hair for propoxur and pyrethroids by gas chromatography/mass spectrometry at 2, 4 and 6 years of age. RESULTS There were significant changes in the prevalence and concentration of propoxur and pyrethroids in childrens hair at 2, 4 and 6 years of age. At ages 2 and 4 years, the prevalence of propoxur exposure increased from 12.4% to 24.1% (p<0.001) but dramatically decreased to 1.7% at 6 years (p<0.001). For bioallethrin, the prevalence of exposure steadily increased from 2 years (0.7%, p<0.001) to 4 years (12.4%, p<0.001) and to 6 years (18.4% p<0.001). Exposure to transfluthrin significantly increased from 4 years (1.0%) to 6 years (9.2%, p<0.001). There were also significantly higher median concentrations of bioallethrin at 2 compared to 4 years and for propoxur at 2 years compared to 6 years. Between 4 and 6 years, there was a higher median concentration of propoxur at 4 compared to 6 years and for transfluthrin and bioallethrin, at 6 compared to 4 years. CONCLUSION Changes in the prevalence and concentration of exposure to propoxur and pyrethroids in children at 2, 4 and 6 years of age are related to the progress in ambulation of young children and to changes in the formulation of home spray pesticides. Thus, periodic monitoring of pesticide exposure is necessary when studying the long term effects of pesticide exposure in the neurodevelopment of young children.

Effect of pulsed magnetic stimulation of the facial nerve on cerebral blood flow

In these experiments we define an effective means of pulsed magnetic stimulation of the facial nerve for the purpose of increasing cerebral blood flow (CBF). In normal anesthetized dog and sheep, a focal magnetic field was directed toward the facial nerve within the temporal bone by placing a 6.5 cm figure-8 stimulation coil over the ear. In an initial set of experiments, CBF was measured by laser Doppler flowmetry and the cerebral vasculature was visualized by angiography. The effect of facial nerve stimulation was found to be dependent on stimulation power, frequency, and the precise positioning of the stimulation coil. Furthermore, an increase in CBF was not observed after direct electrical stimulation in the middle ear space, indicating that non-specific stimulation of the tympanic plexus, an intervening neural structure with vasoactive effects, was not responsible for the increase in CBF after pulsed magnetic stimulation. Subsequent experiments using perfusion MRI demonstrated reproducible increases in CBF throughout the forebrain that manifested bilaterally, albeit with an ipsilateral predominance. These experiments support the development of a non-invasive pulsed magnetic facial nerve stimulator that will increase CBF as a treatment of ischemic stroke.

Meconium analysis to detect fetal exposure to neurotoxicants

Second perspective on the paper by Ortega Garcia et al (see page 642) An accurate detection of fetal exposure to drugs and other compounds (xenobiotics) is essential for studying the true prevalence of antenatal exposure to these compounds and their possible adverse effects on the fetus and infant. The ideal matrix to analyse is one that can be obtained non-invasively and is representative of a wide period of exposure of the fetus throughout gestation. Meconium is formed by the fetus as early as the 12th week of gestation, accumulates throughout pregnancy, and is normally excreted after birth by the infant. Throughout gestation, xenobiotics and their metabolites are principally deposited in meconium either directly from bile secretion or from fetal swallowing of amniotic fluid which contains these compounds which are excreted via the fetal urine. Meconium is therefore a repository of many of the xenobiotics that the fetus is exposed to throughout pregnancy and its analysis has consequently been used for the detection of fetal exposure to illicit drugs. In addition, meconium has also been successfully analysed to detect fetal exposure to various licit drugs and over the counter medications as well as to cotinine and fatty acid ethyl esters …

Analysis of House Dust and Children's Hair for Pesticides: A Comparison of Markers of Ongoing Pesticide Exposure in Children

BACKGROUND/AIM The long term study of the adverse effects of pesticides on child neuro development requires monitoring not only of initial, but ongoing pesticide exposure. Our aim was to compare house dust and childrens hair as environmental and biological markers of ongoing pesticide exposure in children. DESIGN/METHODS In a continuing NIH study on the adverse effects of prenatal pesticide exposure on child neurodevelopment, ongoing pesticide exposure after birth was measured in swept house dust and hair in the children at 4 years of age for propoxur and pyrethroids (transfluthrin, bioallethrin, cyfluthrin and cypermethrin) by gas chromatography/mass spectrometry. The prevalence and concentration of pesticides in the two matrices were compared. RESULTS Prevalence of propoxur was higher in hair compared to house dust (p<0.001) whereas prevalence of the pyrethroids was higher (p<0.001) in house dust. The overall concentrations of the pyrethroids were also higher (p<0.007) in house dust compared to hair. There was a significant (p<0.001) correlation between dust and hair for bioallethrin and cypermethrin. CONCLUSIONS Ongoing exposure of children to environmental pesticides is sensitively detected by analysis of childrens hair and house dust. However, prevalence of propoxur was higher in hair compared to swept house dust, but the opposite was found for the pyrethroids. Thus, both matrices should be analyzed. There was a significant (p<0.001) correlation between house dust and hair for bioallethrin and cypermethrin.

What Is the African American's Experience Following Imago Education?

The purpose of this qualitative study is to explore the African American’s experience following Imago education. Six women and six men were interviewed for this study. Qualitative data analysis resulted in the following themes: (a) improved communication between partners, (b) increased understanding of self, (c) increased understanding of partner, (d) increased understanding of one’s own and one’s partner’s childhood, (e) revealed more of one’s authentic self, and (f) expressed need for more education about Imago therapy within the African American community. Information gained from this study will be of value to the field of psychology, providing culturally pertinent insight about African Americans and how they experience relationships and psychotherapy. The findings are presented and summarized through themes, individual quotes, a composite depiction, and a creative synthesis. Future research in this area would examine the long-term effects of Imago education in this population.