This thesis reinforce that children born preterm are at risk for long-term impairments. Being able to predict who is at risk, by neonatal neuroimaging or early assessment, remains difficult,... Show moreThis thesis reinforce that children born preterm are at risk for long-term impairments. Being able to predict who is at risk, by neonatal neuroimaging or early assessment, remains difficult, especially in children who have milder forms of brain injury and/or experience milder difficulties at two years of age. Currently, most follow-up assessments use standardized outcome measures that might not show the full extent of a child’s daily functioning. Additional measurements and/or the implementation of qualitative research can be of great additional value. Show less
The two-hit stress model predicts that exposure to stress at two different time-points in life may increase or decrease the risk of developing stress-related disorders later in life. Most studies... Show moreThe two-hit stress model predicts that exposure to stress at two different time-points in life may increase or decrease the risk of developing stress-related disorders later in life. Most studies based on the two-hit stress model have investigated early postnatal stress as the first hit with adult stress as the second hit. Adolescence, however, represents another highly sensitive developmental window during which exposure to stressful events may affect programming outcomes following exposure to stress in adulthood. Here, we discuss the programming effects of different types of stressors (social and nonsocial) occurring during adolescence (first hit) and how such stressors affect the responsiveness toward an additional stressor occurring during adulthood (second hit) in rodents. We then provide a comprehensive overview of the potential mechanisms underlying interindividual and sex differences in the resilience/susceptibility to developing stress-related disorders later in life when stress is experienced in two different life stages. Show less
Background: Psychosocial development in monochorionic (MC) twins born after selective fetal growth restriction (sFGR) has been unreported to date, despite its importance for daily functioning and... Show moreBackground: Psychosocial development in monochorionic (MC) twins born after selective fetal growth restriction (sFGR) has been unreported to date, despite its importance for daily functioning and future relationships. Aims: To investigate psychosocial development, attachment and school functioning in MC twins with sFGR and compare outcomes with the general population and between smaller and larger twins. Study design: Observational cohort study. Subjects: MC twins with sFGR (defined as a birth weight discordance >= 20 %) born between 2002 and 2017 and aged 3-17 years. Outcome measures: Multiple parent report questionnaires: the Child Behavior Checklist (social-emotional devel-opment and behavior), the (Early) Childhood Behavior Questionnaire Very Short Form (temperament), the Attachment Insecurity Screening Inventory (attachment) and a school functioning questionnaire. Results: Median age for the 48 twin pairs was 11 (interquartile range (IQR) 8-13) years. Attachment insecurity for both twins was higher than in the general population for ambivalence/resistance (34 % (21/62) vs. 16 %, p = 0.024) and total attachment insecurity (35 % (22/62) vs. 16 %, p = 0.016). Smaller twins had more internalizing behavioral problems, i.e. negative emotions and behaviors turned inwards (22 % (10/46) vs. 11 % (5/46), p = 0.021) and a higher negative affect, i.e. more likely to experience negative emotions (3.2 (2.9-3.7) vs. 2.9 (2.2-3.2), p = 0.009) than larger twins, as well as a lower secondary school level (p = 0.031). Conclusion: MC twins with sFGR have more ambivalent/resistant attachment insecurity following the compli-cated pregnancy course. Smaller twins have a tendency towards negative emotions and internalizing behaviors compared to larger twins, indicating an increased sensitivity for depression and anxiety. Show less
Hulst, A.M. van; Verwaaijen, E.J.; Fiocco, M.F.; Pluijm, S.M.F.; Grootenhuis, M.A.; Pieters, R.; ... ; Heuvel-Eibrink, M.M. van den 2021
Background: Dexamethasone, a highly effective drug in treating pediatric acute lymphoblastic leukemia (ALL), can induce serious neurobehavioral side effects. These side effects are experienced by... Show moreBackground: Dexamethasone, a highly effective drug in treating pediatric acute lymphoblastic leukemia (ALL), can induce serious neurobehavioral side effects. These side effects are experienced by patients and parents as detrimental with respect to health related quality of life (HRQoL). Based on previous studies, it has been suggested that neurobehavioral side effects are associated to cortisol depletion of the mineralocorticoid receptor in the brain. Our previously reported randomized controlled trial, the Dexadagen study (NTR3280), suggests that physiological hydrocortisone addition during dexamethasone treatment may overcome clinically relevant neurobehavioral problems in patients who experience these problems during dexamethasone treatment. With our current study, we aim to replicate these results in a targeted larger sample before further implementing this intervention into standard of care.Methods: In a national center setting, pediatric ALL patients between 3 and 18 years are enrolled in an Identification study, which identifies patients with clinically relevant dexamethasone-induced neurobehavioral side effects using the Strengths and Difficulties Questionnaire (SDQ). Contributing factors, such as genetic susceptibility, dexamethasone pharmacokinetics as well as psychosocial and family factors are studied to determine their influence in the inter-patient variability for developing dexamethasone-induced neurobehavioral side effects.Patients with clinically relevant problems (i.e. a rise of >= 5 points on the SDQ Total Difficulties Score after 5 days of dexamethasone) are subsequently included in a randomized double-blind placebo-controlled trial with a cross-over design. They receive two courses placebo followed by two courses hydrocortisone during dexamethasone treatment, or vice versa, each time at least 16 days without study medication in between. The primary endpoint is change in SDQ score. The secondary endpoints are sleep (measured with actigraphy and the Sleep Disturbance Scale for Children) and HRQoL (Pediatric Quality of Life Questionnaire).Discussion: The results of our current study may contribute to the management of future ALL patients who experience dexamethasone-induced neuropsychological problems as it may improve HRQoL for patients who suffer most from dexamethasone-induced neurobehavioral side effects. Furthermore, by investigating multiple risk factors that could be related to inter-patient variability in developing these side effects, we might be able to identify and treat patients who are at risk earlier during treatment. Show less
In this thesis, we have studied the potential of the zebrafish larval model in studying the ECS, as a complementary model to the existing rodent models. More specifically, we have looked at the... Show moreIn this thesis, we have studied the potential of the zebrafish larval model in studying the ECS, as a complementary model to the existing rodent models. More specifically, we have looked at the role of the ECS in regulating locomotion and anxiety, and its interaction with the hypothalamic-pituitary-interrenal (HPI) axis, or stress axis. This study has provided us with an interesting animal model which allows for pharmacological screening of Cnr1 agonists, and their involvement in the CNS, as shown by a change in locomotion, anxiety-like behavior and HPI axis activity. The zebrafish larval model can be used as a complementary model to the existing rodent animal models, to study the ECS. The zebrafish larval model brings several interesting features, such as optical transparency and possibilities for high-throughput screening. Furthermore, a complete ECS is present, there is lack of endogenous activity, allowing for exogenous compound screening, and zebrafish data is generally in line with rodent literature. Since the ECS is involved in many diseases, more research of this system may result in the discovery of novel drugs and drug targets. Show less
Objective: To compare effects of immediate delivery vs expectant monitoring on neurodevelopmental and behavioral outcomes at 5 years of age in offspring of women with mild late preterm hypertensive... Show moreObjective: To compare effects of immediate delivery vs expectant monitoring on neurodevelopmental and behavioral outcomes at 5 years of age in offspring of women with mild late preterm hypertensive disorders.Study design: We studied children born during the HYPITAT-11 trial, in which 704 women with a hypertensive disorder between 34 and 37 weeks of gestation were randomized to immediate delivery or expectant monitoring. Participating women were asked to complete the Ages and Stages Questionnaire (ASQ) for developmental outcome and the Child Behavior Checklist (CBCL) for behavioral problems when their child was 5 years old. Outcomes were dichotomized and analyzed by logistic regression analysis. We also assessed factors influencing development and behavior at both 2 and 5 years after a hypertensive pregnancy.Results: Five years after the original study 322(46%) women were contacted for follow-up, of whom 148 (46%) responded. In the delivery group 22%(n = 14/65) of the children had an abnormal ASQ score compared to 21% (n = 13/62) in the expectant monitoring group (p = 0.9). Abnormal CBCL-scores were found in 19% (n = 14/72) of the children in the delivery group versus in 27% (n = 20/75) in the expectant monitoring group (p = 0.3). The main predictor of development and behavior at 2 and 5 years was fetal growth restriction (for abnormal development OR 2.1, CI 1.0-4.4; for behavior problems OR 2.2, CI 1.1-5.5). Higher maternal education decreased abnormal behavior outcomes (OR 0.5, CI 0.2-0.9) and a similar tendency was observed for developmental problems (OR 0.6, CI 0.3 - 1.1).Conclusion: We did not find different developmental and behavior outcomes at 5 years of age between a management policy of immediate delivery and expectant management in preterm hypertensive disorders. The increased risk of developmental delay at 2 years of age after immediate delivery, we found in the 2 year follow up study, did not persist at 5 years of age. (C) 2019 Elsevier B.V. All rights reserved. Show less
Psychotic depression is characterized by elevated circulating cortisol, and high daily doses of the glucocorticoid/progesterone antagonist mifepristone for 1 week are required for significant... Show morePsychotic depression is characterized by elevated circulating cortisol, and high daily doses of the glucocorticoid/progesterone antagonist mifepristone for 1 week are required for significant improvement. Using a rodent model, we find that such high doses of mifepristone are needed because the antagonist is rapidly degraded and poorly penetrates the blood-brain barrier, but seems to facilitate the entry of cortisol. We also report that in male C57BL/6J mice, after a 7-day treatment with a high dose of mifepristone, basal blood corticosterone levels were similar to that of vehicle controls. This is surprising because after the first mifepristone challenge, corticosterone remained elevated for about 16 h, and then decreased towards vehicle control levels at 24 h. At that time, stress-induced corticosterone levels of the 1xMIF were sevenfold higher than the 7xMIF group, the latter response being twofold lower than controls. The 1xMIF mice showed behavioral hyperactivity during exploration of the circular hole board, while the 7xMIF mice rather engaged in serial search patterns. To explain this rapid reset of corticosterone secretion upon recurrent mifepristone administration, we suggest the following: (i) A rebound glucocorticoid feedback after cessation of mifepristone treatment. (ii) Glucocorticoid agonism in transrepression and recruitment of cell-specific coregulator cocktails. (iii) A more prominent role of brain MR function in control of stress circuit activity. An overview table of neuroendocrine MIF effects is provided. The data are of interest for understanding the mechanistic underpinning of stress system reset as treatment strategy for stress-related diseases. Show less
The main focus of the research that makes up this thesis was to translate rodent behavioural assays to larval zebrafish for better time and resource management in biomedical research,... Show moreThe main focus of the research that makes up this thesis was to translate rodent behavioural assays to larval zebrafish for better time and resource management in biomedical research, pharmaceutical research and development. __The larval zebrafish is a useful model in toxicology and drug discovery. However, its predictivity is restricted by compound class. __Light-dark cycle plays an important role in the normal development of the zebrafish embryo, and abnormal lighting regimes during rearing can result in malformations. __The hyperactivity displayed by zebrafish larvae following the onset of sudden darkness is an intrinsic characteristic. Zebrafish larvae quickly habituate with repeated stimuli of onset of darkness with short interstimulus interval. __Zebrafish larvae are able to discriminate colours, and they show a preference for orange and green, but aversion towards red, yellow, blue and black. The larvae also show freezing behaviour in the complex environment which is attenuated with diazepam.. __Zebrafish larvae raised in an abnormal lighting regime changed some aspects of their colour preference, although orange and red remained as preferred and avoided colours respectively. __In short, the zebrafish larvae is a useful complementary animal model in behavioural research amenable to high-throughput screening of compounds and drug discovery Show less
In conclusion, the results of the present studies show how schizotypal symptoms may develop following child psychiatric psychopathology and how these symptoms unfavorably influence a persons__... Show moreIn conclusion, the results of the present studies show how schizotypal symptoms may develop following child psychiatric psychopathology and how these symptoms unfavorably influence a persons__ quality of life. It is important for clinicians to be aware of the complex dynamics of psychopathology and the higher risk for adult schizotypal symptomatology following behavioral problems and psychiatric disorders at child and adolescent age. Show less
