Biomedical subjects

Herman van Engeland

Publications and source records attributed to Herman van Engeland.

At least 19 recordsLinked to original sources

PubMed2007

Caudate nucleus is enlarged in high-functioning medication-naive subjects with autism.

BACKGROUND: Autism is defined by three symptom clusters, including repetitive and stereotyped behavior. Previous studies have implicated basal ganglia in these behaviors. Earlier studies investigating basal ganglia in autism have included subjects on neuroleptics known to affect basal ganglia volumes. Therefore, we investigated these structures in medication-naive subjects with autism. METHODS: Volumetric magnetic resonance measures of caudate, putamen, and nucleus accumbens were compared in two independent samples of medication-naive, high-functioning subjects with autism or Asperger syndrome: 1) 21 affected children and adolescents and 21 matched control subjects; and 2) 21 affected adolescents and young adults and 21 matched control subjects. RESULTS: Caudate nucleus was enlarged in both samples. This result remained significant after correction for total brain volume. CONCLUSIONS: These results implicate caudate nucleus in autism, as an enlargement of this structure was disproportional to an increase in total brain volume in two independent samples of medication-naive subjects with autism.

Adolescent↗

PubMed2007

Attachment in toddlers with autism and other developmental disorders.

Attachment was assessed in toddlers with Autistic Disorder (n=20), Pervasive Developmental Disorder (n=14), Mental Retardation (n=12), Language Development Disorder (n=16), and a non-clinical comparison group (n=18), using the Strange Situation Procedure (SSP). Children in the clinical groups were more often disorganized and less often securely attached. Severity of autism was associated with more attachment insecurity, and lower developmental level increased the chance for disorganized attachment. Attachment disorganization was related to increased heart rate during the SSP. Controlling for basal cortisol and developmental level, more autistic symptoms predicted lower cortisol responses to the SSP. The findings support the importance of disorganized attachment for children with autism.

Arousal↗

PubMed2007

Prolactin release in children treated with risperidone: impact and role of CYP2D6 metabolism.

OBJECTIVE: Little is known about the role of CYP2D6 polymorphism in risperidone-induced prolactin release in children. METHOD: Twenty-five children (aged 5-15 years) with pervasive developmental disorders were genotyped for CYP2D6 polymorphisms. Serum prolactin, risperidone, and 9-hydroxyrisperidone were assessed at baseline and after 8 weeks of risperidone treatment (mean dosage, 0.06 +/- 0.03 mg/kg/d). After 24 weeks of treatment, prolactin was measured in a subsample of 15 children. Adverse effects were evaluated using a clinician-rated survey. RESULTS: Mean +/- SD prolactin levels increased from 7.8 +/- 8.0 ng/mL at baseline to 33.2 +/- 12.8 ng/mL at week 8 (P < 0.001), with a slight decrease to 28.8 +/- 13.6 ng/mL at week 24. At week 8, serum prolactin level was positively correlated with dose per kilogram (r = 0.648, P < 0.001), number of functional CYP2D6 genes (J = 2.117, P = 0.034), and serum 9-hydroxyrisperidone concentration (r = 0.664, P = 0.001) and was negatively correlated with the risperidone/9-hydroxyrisperidone ratio (r = -0.571, P = 0.004) but not with risperidone concentration (r = -0.243, P = 0.264) nor age (r = 0.072, P = 0.733). Prolactin elevation was not associated with adverse effects. CONCLUSIONS: Low-to-intermediate doses of risperidone induced a 4-fold prolactin increase in children without a clear development of tolerance up to 6 months. CYP2D6 ultrarapid metabolism may be a risk factor for more pronounced prolactin elevation.

Adolescent↗

PubMed2006

Cortisol moderates the relationship between testosterone and aggression in delinquent male adolescents.

BACKGROUND: In animals, strong evidence exists for an association between testosterone and aggression. In humans, and particularly in children and adolescents, findings have been less consistent. Previous research has suggested that this may partly be due to moderating effects of other factors, e.g., hormones. This study aims to investigate the moderating effect of cortisol on the relationship between testosterone and subtypes of aggression in delinquent male adolescents. METHODS: Participants were 103 boys (mean age 13.7) referred to a delinquency diversion program. Testosterone and cortisol levels were determined from saliva samples collected during resting conditions and related to self-report scores on overt and covert aggression. RESULTS: Linear regression analyses revealed a significant interaction between cortisol and testosterone in relation to overt aggression, with a significant positive relationship between testosterone and overt aggression in subjects with low cortisol levels but not in subjects with high cortisol levels. Using the same model for covert aggression, no significant effects of testosterone, cortisol, or testosterone x cortisol interaction were found. CONCLUSIONS: These results indicate a moderating effect of cortisol on the relationship between testosterone and overt aggression in delinquent male adolescents. Implications and directions for future research are discussed.

Adolescent↗

PubMed2006

Hypothalamus pituitary adrenal axis and autonomic activity during stress in delinquent male adolescents and controls.

OBJECTIVE: Patterns of low autonomic arousal have consistently been related to delinquency and disruptive behavior disorders (DBD) in children and adolescents. Findings on another stress regulating mechanism, the hypothalamic pituitary adrenal (HPA) axis, have been inconsistent, which may partly be due to not considering specific stress reactivity measures. Therefore, the aim of the present study was to investigate the relationship between disruptive behavior in male adolescents and their HPA and autonomic reactivity to a standard public speaking task (PST). METHOD: Responsivity to the PST of cortisol, heart rate (HR), skin conductance level (SCL) and self-reported negative feelings was measured, and compared between 12and14-year-old boys who attended a delinquency diversion program (DP), with and without DBD (DP+, n=22 and DP-, n=49, resectively), and matched normal controls (NC, n=30). DBD diagnoses were based on a structured psychiatric interview. RESULTS: The DP+ group, but not the DP- group, showed a significantly decreased cortisol and HR response during the PST as compared with the NC group. No significant effects were found for SCL. All subjects connoted the task negatively. CONCLUSIONS: The results indicate that low cortisol and HR responsivity to stress may be a neurobiological marker for delinquent boys with DBD, but not for those without DBD. Directions for future research and clinical implications are discussed.

Adolescent↗

PubMed2006

Minicolumnar abnormalities in autism.

Autism is characterized by qualitative abnormalities in behavior and higher order cognitive functions. Minicolumnar irregularities observed in autism provide a neurologically sound localization to observed clinical and anatomical abnormalities. This study corroborates the initial reports of a minicolumnopathy in autism within an independent sample. The patient population consisted of six age-matched pairs of patients (DSM-IV-TR and ADI-R diagnosed) and controls. Digital micrographs were taken from cortical areas S1, 4, 9, and 17. The image analysis produced estimates of minicolumnar width (CW), mean interneuronal distance, variability in CW (V (CW)), cross section of Nissl-stained somata, boundary length of stained somata per unit area, and the planar convexity. On average CW was 27.2 microm in controls and 25.7 microm in autistic patients (P = 0.0234). Mean neuron and nucleolar cross sections were found to be smaller in autistic cases compared to controls, while neuron density in autism exceeded the comparison group by 23%. Analysis of inter- and intracluster distances of a Delaunay triangulation suggests that the increased cell density is the result of a greater number of minicolumns, otherwise the number of cells per minicolumns appears normal. A reduction in both somatic and nucleolar cross sections could reflect a bias towards shorter connecting fibers, which favors local computation at the expense of inter-areal and callosal connectivity.

Adolescent↗

PubMed2006

Activation in ventral prefrontal cortex is sensitive to genetic vulnerability for attention-deficit hyperactivity disorder.

BACKGROUND: Attention-deficit hyperactivity disorder (ADHD) is a heritable neuropsychiatric disorder, associated with atypical patterns of brain activation in functional imaging studies. Neuroimaging measures may serve as an intermediate phenotype in genetic studies of ADHD, as they are putatively more closely linked to gene expression than a clinical diagnosis. METHODS: We used rapid, mixed-trial, event-related functional magnetic resonance imaging (fMRI) to investigate changes in brain activation during a go no-go task in boys with ADHD, their unaffected siblings, and matched control subjects. RESULTS: On the hardest inhibitory trials in our task, children and adolescents with ADHD had lower accuracy than control subjects, whereas their unaffected siblings did not. Control subjects activated a network of regions, including ventral prefrontal and inferior parietal cortex. Both children and adolescents with ADHD and their unaffected siblings showed decreased activation in these areas, as well as fewer correlations between performance and activation. CONCLUSIONS: These findings suggest that the magnitude of activation during successful inhibitions is sensitive to genetic vulnerability for ADHD in a number of regions, including ventral prefrontal cortex. If this can be replicated in future studies, this suggests that neuroimaging measures related to inhibitory control may be suitable as intermediate phenotypes in studies investigating gene effects in ADHD.

Adolescent↗

PubMed2006

Characteristics of early psychosis.

There is little research on characteristics related to course and prognosis of early-onset psychosis. The present article aims to advance our knowledge of this disorder for the purpose of proper diagnosis and treatment. It focuses on premorbid and prodromal characteristics, treatment history, symptoms and classifications, and differences between subgroups with affective and schizophrenic psychosis. A chart review was constructed to study a group of 129 subjects (12-18 years) with psychotic symptoms referred to the University Medical Center in Utrecht. The group was characterized by early-but nonspecific-treatment, developmental problems (mostly social), and clear prodromal symptoms. Drug abuse, depressive symptoms, and suicidal behavior were also frequent. Male sex, a relatively long prodromal phase, school problems, and drug abuse were more indicative of the schizophrenic subgroup. Introversion was characteristic for boys with schizophrenia. Classifications, however, were not stable. These findings suggest that early recognition of psychosis can be enhanced in health and youth care facilities. Careful examination of the prodromal phase seems helpful to differentiate between schizophrenic and affective psychosis.

Adolescent↗

PubMed2006

Salivary testosterone and aggression, delinquency, and social dominance in a population-based longitudinal study of adolescent males.

Testosterone (T) has been found to have a stimulating effect on aggressive behavior in a wide range of vertebrate species. There is also some evidence of a positive relationship in humans, albeit less consistently. In the present study we investigated the relationship between T and aggression, dominance and delinquency over time, covering a period from early adolescence to adulthood. From a large population-based sample (n = 1.161) a subgroup of 96 boys was selected whose behavior had been assessed repeatedly by different informants from age 12 to 21 years, and who had provided multiple T samples over these years of assessment. On the whole, a decrease in aggressive and delinquent behavior was observed in a period in which T rises dramatically. Boys who developed a criminal record, had higher T levels at age 16. In addition, positive associations were observed between T and proactive and reactive aggression and self-reported delinquent behavior. Over the pubertal years different forms of aggressive and delinquent behavior were positively related to T, which may indicate that specific positive links are dependent on the social setting in which this relationship is assessed.

Adolescent↗

PubMed2006

A parent questionnaire for distinguishing between reactive and proactive aggression in children.

BACKGROUND: Evidence suggests that reactive and proactive aggression can be distinguished on the basis of teacher-rating scales. In this article a newly developed parent-rated questionnaire that aims to distinguish between reactive and proactive aggression is evaluated with regard to its structure and validity. METHOD: In study 1, a confirmatory factor analysis was performed on the data of 442 children aged 6-12 years of a general population. Study 2 examined the relations between the two forms of aggression and hostile intentions, expected outcome of aggression, ADHD symptoms and callous-unemotional traits in a sample of 40 normal and 40 disruptive behaviour disordered boys aged 8-12 years. RESULTS: The confirmatory factor analysis showed that the two-factor model, unlike a singlefactor model, produced a reasonable fit to the data. The results of study 2 showed that the correlations between the different variables and reactive aggression differed from the correlations with proactive aggression in ways that were consistent with theoretical definitions and earlier findings. CONCLUSION: These results, in addition to those of earlier studies using teacher-rating scales, suggest that it is possible to make a valid distinction between reactive and proactive aggression using this newly developed parent-rated questionnaire.

Child↗

PubMed2006

ERPs and eye movements reflect atypical visual perception in pervasive developmental disorder.

Many studies of eye tracking or event-related brain potentials (ERPs) in subjects with Pervasive Developmental Disorder (PDD) have yielded inconsistent results on attentional processing. However, recent studies have indicated that there are specific abnormalities in early processing that are probably related to perception. ERP amplitudes in response to visual stimuli, measured above the occipital (modality-specific) cortex, are reported to be abnormally small in patients with PDD, and the abnormal visual processing is possibly associated with the spatial visual frequency content of stimuli. It is suggested that subjects with PDD show abnormal activation of visual pathways dedicated to the processing of high and low spatial frequencies.

Attention↗

PubMed2006

Abnormal selective attention normalizes P3 amplitudes in PDD.

This paper studied whether abnormal P3 amplitudes in PDD are a corollary of abnormalities in ERP components related to selective attention in visual and auditory tasks. Furthermore, this study sought to clarify possible age differences in such abnormalities. Children with PDD showed smaller P3 amplitudes than controls, but no abnormalities in selective attention. Adolescents with PDD showed abnormal selective attention, as reflected by larger auditory Processing Negativity (PN) and visual N2b, but no P3 abnormalities. Dipole localizations revealed that the locations of PN generators in subjects with PDD differed from controls. It was concluded that the abnormalities in selective attention in adolescents with PDD have a normalizing effect on P3, and possibly act as a compensatory process.

Adolescent↗

PubMed2006

Superior disembedding performance of high-functioning individuals with autism spectrum disorders and their parents: the need for subtle measures.

We assessed the disembedding performance on the Embedded Figures Test (EFT) of high-functioning subjects with autism or autism spectrum disorders from multi-incidence families and the performance of their parents. The individuals with autism spectrum disorders were significantly faster than matched controls in locating the shape, but their parents were not faster than a control group of parents. However, both the individuals with autism spectrum disorders and their fathers made significantly fewer incorrect attempts before finding the right shape than matched controls. These results suggest that the number of incorrect attempts is a more subtle measure than accuracy or response time for assessing superior disembedding skills and therefore may be useful in the assessment of individuals with autism spectrum disorders.

Adolescent↗

PubMed2006

Screening for autistic spectrum disorder in children aged 14-15 months. II: population screening with the Early Screening of Autistic Traits Questionnaire (ESAT). Design and general findings.

A two-stage protocol for screening for autistic spectrum disorders (ASD) was evaluated in a random population of 31,724 children aged 14-15 months. Children were first pre-screened by physicians at well-baby clinics using a 4-item screening instrument. Infants that screened positive were then evaluated during a 1.5-h home visit by a trained psychologist using a recently developed screening instrument, the 14-item Early Screening of Autistic Traits Questionnaire (ESAT). Children with 3 or more negative scores were considered to be at high-risk of developing ASD and were invited for further systematic psychiatric examination. Eighteen children with ASD were identified. The group of children with false positive results had related disorders, such as Language Disorder (N = 18) and Mental Retardation (N = 13).

Autistic Disorder↗

PubMed2006

Screening for autistic spectrum in children aged 14 to 15 months. I: the development of the Early Screening of Autistic Traits Questionnaire (ESAT).

This article describes the development of a screening instrument for young children. Screening items were tested first in a non-selected population of children aged 8-20 months (n = 478). Then, parents of children with clinically diagnosed ASD (n = 153, average age 87 months) or ADHD (n = 76, average age 112 months) were asked to score the items retrospectively for when their child was 14 months old. A 14-item screening instrument, Early Screening of Autistic Traits (ESAT) which had maximal sensitivity and specificity for ASD was developed. The sensitivity of the ESAT was checked in an independent sample of 34 children aged 16-48 months clinically diagnosed with ASD. A 4-item version appears to be a promising prescreening instrument.

Asperger Syndrome↗

PubMed2006

Autonomic and neuroendocrine responses to a psychosocial stressor in adults with autistic spectrum disorder.

Objective of the study was to replicate in adults our previous findings of decreased heart rate and normal endocrine responses to stress in autistic children and to elucidate the discrepancy between autonomic and endocrine stress responses by including epinephrine, norepinephrine, oxytocin and vasopressin measurements. Ten autistic spectrum disorder (ASD) adults were compared to 14 healthy controls in their response to a psychosocial stressor (public speaking). ASD patients showed decreased heart rate, but normal cortisol responses, consistent with our prior findings in children. No differences in norepinephrine, epinephrine, oxytocin or vasopressin responses to stress were found. However, in contrast to previous findings in low functioning autistic children, ASD adults showed increased basal oxytocin levels, which may be related to developmental factors.

Adrenocorticotropic Hormone↗

PubMed2006

The 22q11.2 deletion in children: high rate of autistic disorders and early onset of psychotic symptoms.

OBJECTIVE: To examine psychopathology and influence of intelligence level on psychiatric symptoms in children with the 22q11.2 deletion syndrome (22q11DS). METHOD: Sixty patients, ages 9 through 18 years, were evaluated. Assessments followed standard protocols, including structured and semistructured interviews of parents, videotaped psychiatric interview, and intelligence assessment of the child. Intelligence level, psychiatric symptoms, and classification provided the main outcome. RESULTS: High rates of autism spectrum disorders (30 of 60, 50.0%) and psychotic symptoms (16 of 60, 26.7%) were found in this sample. In 7 of 60 (11.7%), the psychotic symptoms interfered with behavior and caused considerable distress. In these cases, the diagnosis of a psychotic disorder was applied. The average age of the children with psychotic symptoms at time of assessment was 14.2 years. Although it is likely that the high rate of psychopathology in this sample is to some extent associated with the lower level of cognitive function, a major effect of the degree of cognitive impairment on psychiatric morbidity was not found. CONCLUSION: Autism spectrum disorders and subthreshold autistic symptomatology are common in children with 22q11DS. Furthermore, a high rate of psychosis and psychotic symptoms is found in this childhood sample, suggesting an early onset of psychosis in 22q11DS patients. Autistic and psychotic disorders should be considered to be main elements of the behavioral phenotype of 22q11DS children.

Adolescent↗

PubMed2005

Olanzapine reduces physical activity in rats exposed to activity-based anorexia: possible implications for treatment of anorexia nervosa?

BACKGROUND: Anorexia nervosa (AN) patients often show extreme hypophagia and excessive physical activity. Activity-based anorexia (ABA) is considered an animal model of AN and mimics food restriction and hyperactivity in rats. This study investigated whether treatment with olanzapine (Zyprexa) reduces the development of ABA in rats. The effect of olanzapine treatment in AN patients was also evaluated in a small open-label study. METHODS: Rats were chronically (1 week) infused with olanzapine (7.5 mg/kg) and exposed to the ABA model or ad libitum feeding. Hyperactive AN patients were followed for up to 3 months of olanzapine treatment (5 mg/kg). RESULTS: Olanzapine treatment reduced development of ABA in rats by reducing running wheel activity, starvation-induced hypothermia and activation of the hypothalamus-pituitary-adrenal axis. Olanzapine treatment reduced activity levels of AN patients compared with untreated AN patients, without affecting body weight and plasma leptin levels. CONCLUSIONS: Olanzapine treatment reduced wheel running and thereby diminished development of ABA in rats. Olanzapine treatment also reduced physical activity in hyperactive AN patients in a small open-label study. These data support the need for controlled studies investigating the putative beneficial effects of olanzapine treatment in AN patients.

Adipose Tissue↗