Prenatal exposure to endocrine disrupting chemicals is associated with altered DNA methylation in cord blood

Prenatal exposure to endocrine disrupting chemicals can interfere with development, and has been associated with social-cognitive functioning and adverse health outcomes later in life. Exposure-associated changes of DNA methylation (DNAm) patterns have been suggested as a possible mediator of this relationship. This study investigated whether prenatal low-dose exposure to polychlorinated biphenyls (PCBs) and polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) is associated with altered DNAm patterns across the genome in a Western urban-industrial population. In 142 mother-infant pairs from the Duisburg Birth Cohort Study, PCBs and PCDD/Fs levels were quantified from maternal blood during late pregnancy and associated with DNAm levels in cord blood using the Illumina EPIC beadchip. The epigenome-wide association studies (EWAS) identified 32 significantly differentially methylated positions (DMPs) and eight differentially methylated regions (DMRs) associated with six congeners of PCB and PCDD in females or males (FDRs < 0.05). DMPs and DMRs mapped to genes involved in neurodevelopment, gene regulation, and immune functioning. Weighted gene correlation network analysis (WGCNA) showed 31 co-methylated modules (FDRs < 0.05) associated with one congener of PCDF levels in females. Results of both analytical strategies indicate that prenatal exposure to PCBs and PCDD/Fs is associated with altered DNAm of genes involved in neurodevelopment, gene expression and immune functioning. DNAm and gene expression levels of several of these genes were previously associated with EDC exposure in rodent models. Follow-up studies will clarify whether these epigenetic changes might contribute to the origin for adverse mental and health outcomes.

Der Zusammenhang zwischen Schlafproblemen, unzureichender Schlafdauer und psychischen Auffälligkeiten bei Kindern und Jugendlichen

Zusammenfassung. Schlafprobleme und eine unzureichende Schlafdauer können die psychische Gesundheit im Kindes- und Jugendalter nachhaltig beeinträchtigen. Daten von 6.670 Jungen und Mädchen im Alter von 11 – 13 und 14 – 17 Jahren, aus dem Kinder- und Jugendgesundheitssurvey (KIGGS), wurden getrennt nach Geschlechtern analysiert, um zu untersuchen, ob Schlafprobleme und eine unzureichende Schlafdauer mit einer höheren Risikowahrscheinlichkeit für psychische Auffälligkeiten einhergehen. Während Schlafprobleme unabhängig von Geschlecht und Alter mit einem höheren Risiko für alle Symptombereiche (OR = 1.52 – 3.49) verbunden sind, findet sich hinsichtlich einer geringen Schlafdauer nur bei Mädchen eine höheres Risikowahrscheinlichkeit für Auffälligkeiten im externalisierenden und internalisierenden Bereich. Damit scheint sich der Zusammenhang zwischen unzureichender Schlafdauer und psychischen Auffälligkeiten bei Jungen und Mädchen zu unterscheiden. Mögliche Ursachen und Implikationen für die pädiatrische und psychiatrische Praxis werden diskutiert.

The relationship between attention and deferred imitation in 12-month-old infants

Imitation is a frequent behavior in the first years of life, and serves both a social function (e.g., to interact with others) and a cognitive function (e.g., to learn a new skill). Infants differ in their temperament, and temperament might be related to the dominance of one function of imitation. In this study, we investigated whether temperament and deferred imitation are related in 12-month-old infants. Temperament was measured via the Infant Behavior Questionnaire Revised (IBQ-R) and parts of the Laboratory Temperament Assessment Battery (Lab-TAB). Deferred imitation was measured via the Frankfurt Imitation Test for 12-month-olds (FIT-12). Regression analyses revealed that the duration of orienting (IBQ-R) and the latency of the first look away in the Task Orientation task (Lab-TAB) predicted the infants' imitation score. These results suggest that attention-related processes may play a major role when infants start to imitate.

Mothers’ socialisation goals and evaluations of desirable and undesirable everyday situations in two diverse cultural groups

Long-term socialisation goals and evaluations of infant behaviour in a variety of everyday contexts were studied among 45 mothers who had immigrated from Central America to the United States, and 41 mothers from European American backgrounds. In accord with expectations based on broad cultural constructs, mothers from Central America emphasised long-term socialisation goals related to Proper Demeanour. In addition, when describing and evaluating everyday situations, they were likely to attribute the desirability or undesirability of these situations to the child's own appropriate and cooperative behaviour, and were likely to highlight mutual enjoyment when describing preferred play situations. In contrast, Euro-American mothers emphasised long-term socialisation goals related to Self-Maximisation, and when describing undesirable everyday situations, stressed the role of external factors not under the child's control, presumably to preserve the child's self-esteem. However, it was also found that the Central American mothers endorse selected aspects of individualism related to promoting their children's economic and personal potential in the United States. These findings point not only to the multidimensional nature of individualism, but also to the heterogeneity of beliefs among Latino populations. The importance of studying within-group variation with regard to the individualism/sociocentrism construct is highlighted.

Attachment Security and Maternal Concepts of Ideal Children in Northern and Southern Germany

The degree of attachment security and the concept of an "ideal child" were investigated by asking 83 mothers to describe the secure-base behaviour of either their own children or of an imagined "ideal child" using a German translation of Waters' (1987) Attachment Q-Set. Additionally, 11 German experts generated a "maximally secure" criterion sort, which was virtually identical with the established US criterion sort. Attachment security is highly desirable, as shown by the similarity between the profiles of the ideal descriptions and the security criterion sort. Two subsamples from Northern and Southern Germany showed similar intercorrelations of Attachment Q-Set subscales. We identified small differences in Northern and Southern mothers' perceptions of an "ideal" child in items relating to activity and independence. However, Northern and Southern mothers' descriptions of their toddlers did not differ in attachment security or dependence.

The Ecology of Mother-Infant Interaction in Euro-American and Immigrant Central American Families Living in the United States

In an attempt to explore cultural and subcultural similarities and variations in the patterns of child care, two culturally and economically distinct groups were studied. Twenty-one 3-month-old infants had well-educated Euro-American mothers and another 17 had recently migrated Central American mothers. Observations of parent-infant interaction and behaviour were conducted at home throughout the day to ensure coverage of complete 12-hour cycles. Descriptive analyses revealed remarkable similarities and few differences in the everyday experiences of infants in these two diverse groups. Both groups of mothers spent most of their time playing with, feeding, or caring for their infants. Fathers spent little time with their infants during the day but their presence affected the amount of time spent in various contexts, with significantly less object play occurring when the fathers were present. Mother and infant vocalisations and mutual attention occurred more frequently during social interaction and caretaking than in bouts of feeding. These descriptive profiles expand our basic understanding of infants’ everyday experiences in diverse subcultural groups.

ATTENTION FUNCTIONING IN CHILDREN WITH PRENATAL DRUG EXPOSURE

Children born to drug abusers are exposed to teratogenic influences on intrauterine brain development and undergo postnatal withdrawal. We investigated the interplay of different domains and levels of attention functioning in 24 prenatally exposed and 25 nonexposed children who were 5 to 6 years old. Assessment included parent ratings and neuropsychological and electrophysiological methods. Exposed children had a higher prevalence of attention deficit hyperactivity symptoms, tended to have poorer performance in an attention test battery, and showed EEG alterations in P3 and N2c. Findings suggest long-term effects of prenatal drug exposure on specific domains and on different levels of attention functioning.

Influence of Low-Level Prenatal Exposure to PCDD/Fs and PCBs on Empathizing, Systemizing and Autistic Traits: Results from the Duisburg Birth Cohort Study

BACKGROUND

Polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and polychlorinated biphenyls (PCBs) are assumed to act as endocrine disruptor chemicals. Prenatal exposure to these pollutants might influence fetal steroid hormone levels, which are thought to be related to sex-typical development and autistic traits.

OBJECTIVES

We examined associations of prenatal levels of PCDD/Fs and PCBs with autism traits and sex-typical behaviour in childhood.

METHODS

We measured levels of PCDD/Fs and PCBs in maternal blood samples during pregnancy using gas chromatography/high-resolution mass spectrometry. Sex-typical behaviour was assessed at 9 years of age (n = 96) and autistic traits at 10 years of age using the Social Responsiveness Scale (SRS; n = 100). Multiple regression analyses were conducted to estimate the associations between prenatal exposure and outcome variables.

RESULTS

Blood concentrations (WHO2005-TEq) of ƩPCDD/Fs ranged from 2.93-46.45 pg/g lipid base (median = 12.91 pg/g lipid base) and concentrations of ƩPCBs were in the range of 1.24-25.47 pg/g lipid base (median = 6.85 pg/g lipid base) which is within the range of German background exposure. We found significant negative associations between PCDD/F levels in maternal blood and SRS scores in the whole group (β = -6.66, p < .05), in girls (β = -10.98, p < .05) and, in one SRS subscale, in boys (β = -6.86, p < .05). For PCB levels, associations with one SRS subscale were significant for the whole study group as were associations with two subscales in girls. We did not find significant associations between PCDD/F or PCB levels and sex-typical behaviour for either sex.

CONCLUSIONS

In an earlier part of this study, prenatal exposure to PCDD/Fs and PCBs was found to be associated with lower testosterone levels, therefore, our findings are consistent with the idea that autism spectrum conditions are related to fetal androgen levels. Several possible mechanisms, through which PCDD/Fs and PCBs might influence autistic behaviour, are discussed.

Zur Konstruktvalidität der selektiven Aufmerksamkeit in einer computergestützten Testbatterie zur Aufmerksamkeitsprüfung für Kinder (KITAP)

Die Fähigkeit zur selektiven Aufmerksamkeit hat eine hohe Relevanz für die psychosoziale Entwicklung von Kindern. Durch die Analyse der Testergebnisse von N = 467 Kindern (52 % Jungen) im Alter von 7 bis 10 Jahren (M = 105.23 Monate; SD = 5.87) in den Subtests Go/NoGo und Ablenkbarkeit der KITAP werden statistische Zusammenhänge dargestellt. Zudem werden Annahmen aus einer theoretischen Perspektive bezüglich selektiver Aufmerksamkeit in der KITAP überprüft. Insgesamt ist es nicht gelungen eine Modellspezifikation selektiver Aufmerksamkeit darzustellen, die die vorliegenden Daten angemessen repräsentiert. Eine exploratorische Faktorenanalyse ergab drei Faktoren (Leistungsgeschwindigkeit, Leistungsgüte und Interferenzeffekt) mit einer Varianzaufklärung von 45 %. Zudem wurden Alters- und Geschlechtsunterschiede gefunden. Die Reliabilitätskennwerte sind mit denen in der Normstichprobe vergleichbar und können nur teilweise als befriedigend eingestuft werden. Folgerungen für die differenzierte Interpretation der beiden KITAP-Subtests werden diskutiert.

The influence of low level pre- and perinatal exposure to PCDD/Fs, PCBs, and lead on attention performance and attention-related behavior among German school-aged children: results from the Duisburg Birth Cohort Study

BACKGROUND

Prenatal exposure to polychlorinated biphenyls (PCBs) and lead are thought to be risk factors for attention-deficit hyperactivity disorder (ADHD), whereas the prenatal influence of polychlorinated dibenzo-p-dioxins and -furans (PCDD/Fs) on attention performance has been less studied.

OBJECTIVES

Within the Duisburg Birth Cohort Study, we investigated low-level exposure to these compounds in relation to children's attention.

METHODS

We measured blood levels of PCDD/Fs, PCBs and lead from pregnant mothers (32(nd) week of pregnancy) and PCDD/Fs and PCBs in breast milk (2 weeks after delivery). The attention of school-aged children (N=117) was investigated with a computer-based test battery of attention performance (KITAP) and a parent rating questionnaire of behaviors related to ADHD (FBB-ADHS). Influences of the exposure on attention were analyzed by multiple regression analyses.

RESULTS

Increasing prenatal PCDD/F and PCB concentrations were significantly (p<0.05) associated with a higher number of omission errors in the subtest Divided Attention (47% and 42%; 95% confidence intervals (95%-CI): 1.08-2.00 and 1.07-1.89, respectively). Prenatal lead concentrations had few significant associations with attention performance (e.g., a 23% higher number of omission errors in the subtest Distractibility; 95%-CI: 1.00-1.51), whereas ADHD-related behavior (questionnaire based) was increased with increasing lead exposure (Overall-ADHD: 9%; 95%-CI: 1.01-1.17). ADHD-related behavior was negatively associated with prenatal PCDD/F or PCB exposures (e.g., for PCB exposure: -10%; 95%-CI: 0.82-0.99).

CONCLUSIONS

Pre- and perinatal PCDD/F and PCB exposure may have subtle influences on attention performance in healthy children at low environmental levels, while behavior changes are negatively associated. Furthermore, we provide additional evidence for the impact of prenatal lead exposure on attention deficits.

Die computergestützte Aufmerksamkeitstestbatterie für Kinder (KITAP): Zusammenhänge mit dem Arbeitsgedächtnis und der Verarbeitungsgeschwindigkeit

Die vorliegende Studie überprüft Zusammenhänge zwischen verschiedenen Aspekten der Aufmerksamkeit (Subtests der KITAP: Ablenkbarkeit, Alertness, Flexibilität, geteilte Aufmerksamkeit und Go/NoGo) mit kognitiven Leistungen (Subskalen im HAWIK-IV: Verarbeitungsgeschwindigkeit und Arbeitsgedächtnis). Dazu wurden N = 456 Kinder (52.2 % Jungen) im Alter von 7 bis 10 Jahren (M = 105 Monate, SD = 5.86) untersucht. Die Aspekte der Aufmerksamkeit ließen sich nicht überzeugend differenzieren, eine konfirmatorische Faktorenanalyse ergab zwei latente Variablen (Leistungsgeschwindigkeit und Leistungsgüte) mit gutem Modellfit. Die Leistungsgüte hängt signifikant mit dem Arbeitsgedächtnis und der Verarbeitungsgeschwindigkeit zusammen (r = -.31 bzw. r = -.24). Die Leistungsgeschwindigkeit zeigt bedeutsame, aber niedrigere Zusammenhänge mit den kognitiven Leistungen. Folgerungen für die differenzierte Interpretation der KITAP-Subtests werden diskutiert.

Breast feeding initiation and duration: comparison of French and German mothers

BACKGROUND

approximately 56% of babies in France are breast fed at birth compared with approximately 91% in Germany. Few studies have compared these neighbouring countries despite the similarities in their social systems.

OBJECTIVES

to compare breast-feeding initiation and duration from birth to 3 months post partum between French and German mothers, as well as reasons for breast-feeding cessation in the first 3 months.

DESIGN

mothers were contacted twice during the study: immediately after childbirth and at 3 months post partum.

PARTICIPANTS

126 French mothers were recruited during their maternity stay in hospital, and 80 German women were recruited by their midwives and contacted via regular mail. All women were primiparous.

METHODS

breast-feeding rates at birth and 3 months post partum were collected and compared. In addition, reasons for breast-feeding cessation in the first 3 months were explored and analysed.

RESULTS

96% of German women initiated breast feeding at birth and 83% were still breast feeding at 3 months post partum. In comparison, 67% of French women initiated breast feeding at birth and 34% were still breast feeding at 3 months post partum.

CONCLUSION

there is a need for postnatal follow-up care for French mothers who breast feed. Follow-up care available for German mothers shows encouraging results.

Assessment of Migrant and Minority Children

Testing children with minority status or migration background poses particular challenges for educators and researchers. More obvious are language barriers, but there may also be more complex limitations based on cultural or contextual differences. The literature on testing migrant and minority children is summarized in a brief historical perspective, focusing on the use of standardized tests. Potential biases in testing minority and migrant children are discussed, and empirical results of testing two groups of preschool age children of nonmigrant (N = 50) and migrant status (N = 35) with the ET 6–6 in Germany are presented. Results indicate significant group differences to the disadvantage of the migrant children in some scales, however, both groups scored within the normal range of one standard deviation around the test norm. The migrant group children were tested in their dominant language, and they used more time to complete the test. Interpretation of test results should use caution, particularly when using tests to support placement in educational settings.

Geschlechtsspezifische Entwicklung der Anatomie und Gangdynamik im Kindes- und Jugendalter

Zusammenfassung. Im Verlauf der Kindheit werden Unterschiede zwischen Jungen und Mädchen im Körperbau und der Bewegungsdynamik sichtbar. Die Entwicklung von Körperproportionen und der Gangdynamik wurde an einer Querschnittsstichprobe von 27 Mädchen und 27 Jungen im Alter von 4 bis 16 Jahren analysiert. Zur Synthese digitalisierter Point-Light Modelle wurden die Gangmuster der Probanden im dreidimensionalen Raum erfasst. Lineare Diskriminanzfunktionen der Bewegungsinformation erlauben die überzufällig korrekte Zuordnung individueller Gangmuster nach Alter und Geschlecht, wobei die Präzision mit dem Alter ansteigt. Berechnet man die Diskriminanzfunktion als altersspezifische Funktion innerhalb von drei Altersgruppen, ergibt sich zusätzlich zur dynamischen Identifikation eine korrekte Zuordnung auf Grund der strukturellen anatomischen Information. Korrelative Zusammenhänge zwischen altersspezifischen Körperproportionen und dynamischen Aspekten treten dabei für Mädchen und Jungen in unterschiedlichen Entwicklungsphasen auf. Diese Ergebnisse werfen ein neues Licht auf die bisherigen Erkenntnisse der anthropometrischen Forschung und die Entwicklung von geschlechtsspezifischen Bewegungsmustern.

Socialization goals among first- and second-generation migrant Turkish and German mothers

The current study examines generational differences in Turkish mothers' socialization goals following migration to Germany. A total of 78 working-class mothers from three different groups (Turkish first- and second-generation, and German non-migrant) participated. Each mother had a child between 18 and 36 months of age. Mothers were interviewed using the Socialization Goals Interview. The results indicate that compared to both groups of Turkish mothers, German mothers placed more emphasis on self-control as a socialization goal, and compared with the first-generation mothers only, were more concerned that their child develop characteristics associated with psychological independence and self-confidence. Among the Turkish mothers, more highly educated mothers placed less emphasis on the importance of respect towards others than did less educated mothers.

Retrospektive Erfassung frühkindlicher Beziehungsaspekte: Konstruktion der Beziehungs-Kontext-Skala

Zusammenfassung. Testkennwerte einer Skala zur retrospektiven Erfassung innerfamiliärer Beziehungsaspekte der ersten acht Lebensjahre wurden an einer Stichprobe (N = 333) aus Ost- und Westdeutschland (Halle/Saale und Osnabrück) erhoben, wobei sich die interne Konsistenz (α = .92) und der mittlere Trennschärfeindex (rit = .56) als zufriedenstellend erweist. Die Beziehungs-Kontext-Skala setzt sich aus fünf Subskalen zusammen, die sich als “Qualität der elterlichen Beziehung”, “Qualität der Beziehung zur Mutter”, “Qualität der Beziehung zum Vater”, “Familiäre Beziehungen” und “Familiäre Harmonie” interpretieren lassen. Ostdeutsche Untersuchungsteilnehmer haben signifikant höhere Werte in der Subskala “Familiäre Beziehungen” und “Familiäre Harmonie”. Vergleiche soziodemographischer Subgruppen sowie Zusammenhänge mit einem familiendiagnostischen Meßinstrument ( Gehring, 1993 ) weisen auf eine beachtliche Validität der Skala und ihrer Dimensionen hin. Kritisch diskutiert wird die Bedeutung retrospektiver psychometrischer Verfahren für die Entwicklungspsychologie.

Culture and early infancy among central African foragers and farmers

Everyday infant experiences among the Aka hunter-gatherers and the neighboring Ngandu farmers were observed and compared. Twenty Aka and 21 Ngandu 3- to 4-month-olds and 20 Aka and 20 Ngandu 9- to 10-month-olds were observed for 3 hr on each of 4 days so that all 12 daylight hr were covered. The Aka infants were more likely to be held, fed, and asleep or drowsy, whereas Ngandu infants were more likely to be alone and to fuss or cry, smile, vocalize, or play. The amount of crying, soothing, feeding, and sleeping declined over time in both groups. Distal social interaction increased over time among the Ngandu but not among the Aka. Despite striking cultural differences on many variables, however, functional context systematically affected the relative prominence of the infants' behavior in both cultural groups.

Culture and early infancy among central African foragers and farmers

Everyday infant experiences among the Aka hunter-gatherers and the neighboring Ngandu farmers were observed and compared. Twenty Aka and 21 Ngandu 3- to 4-month-olds and 20 Aka and 20 Ngandu 9- to 10-month-olds were observed for 3 hr on each of 4 days so that all 12 daylight hr were covered. The Aka infants were more likely to be held, fed, and asleep or drowsy, whereas Ngandu infants were more likely to be alone and to fuss or cry, smile, vocalize, or play. The amount of crying, soothing, feeding, and sleeping declined over time in both groups. Distal social interaction increased over time among the Ngandu but not among the Aka. Despite striking cultural differences on many variables, however, functional context systematically affected the relative prominence of the infants' behavior in both cultural groups.