The Circadian System Is a Target and Modulator of Prenatal Cocaine Effects

BACKGROUND. Prenatal exposure to cocaine can be deleterious to embryonic brain development, but the results in humans remain controversial, the mechanisms involved are not well understood and effective therapies are yet to be designed. We hypothesize that some of the prenatal effects of cocaine might be related to dysregulation of physiological rhythms due to alterations in the integrating circadian clock function. METHODOLOGY AND PRINCIPLE FINDINGS. Here we introduce a new high-throughput genetically well-characterized diurnal vertebrate model for studying the mechanisms of prenatal cocaine effects by demonstrating reduced viability and alterations in the pattern of neuronal development following repeated cocaine exposure in zebrafish embryos. This effect is associated with acute cocaine-induced changes in the expression of genes affecting growth (growth hormone, zGH) and neurotransmission (dopamine transporter, zDAT). Analysis of circadian gene expression, using quantitative real-time RT-PCR (QPCR), demonstrates that cocaine acutely and dose-dependently changes the expression of the circadian genes (zPer-3, zBmal-1) and genes encoding melatonin receptors (zMelR) that mediate the circadian message to the entire organism. Moreover, the effects of prenatal cocaine depend on the time of treatment, being more robust during the day, independent of whether the embryos are raised under the light-dark cycle or in constant light. The latter suggests involvement of the inherited circadian factors. The principal circadian hormone, melatonin, counteracts the effects of cocaine on neuronal development and gene expression, acting via specific melatonin receptors. CONCLUSIONS/SIGNIFICANCE. These findings demonstrate that, in a diurnal vertebrate, prenatal cocaine can acutely dysregulate the expression of circadian genes and those affecting melatonin signaling, growth and neurotransmission, while repeated cocaine exposure can alter neuronal development. Daily variation in these effects of cocaine and their attenuation by melatonin suggest a potential prophylactic or therapeutic role for circadian factors in prenatal cocaine exposure.National Institutes of Health (DA1541801, MH 065528); National Institute on Drug Abuse (DA-4-7733

Histomorphological study of the spinal growth plates from the convex side and the concave side in adolescent idiopathic scoliosis

Asymmetrical growth of the vertebrae has been implicated as one possible etiologic factor in the pathogenesis of adolescent idiopathic scoliosis. The longitudinal vertebral growth derives from the endochondral ossification of the vertebral growth plate. In the present study, the growth plates from the convex and concave side of the vertebrae were characterized by the method of histology and immunohistochemistry to evaluate the growth activity, cell proliferation, and apoptosis. Normal zoned architectures were observed in the convex side of the growth plate and disorganized architectures in the concave side. The histological grades were significantly different between the convex and the concave side of the growth plate in the apex vertebrae (P < 0.05). The histological difference was also found significant statistically between end vertebrae and apex vertebrae in the concave side of vertebral growth plates (P < 0.05). The proliferative potential indexes and apoptosis indexes of chondrocytes in the proliferative and hypertrophic zone in the convex side were significantly higher than that in the concave side in the apex vertebral growth plate (P < 0.05). There was a significant difference of the proliferative potential index (proliferating cell nuclear antigen, PCNA index) between convex side and concave side at the upper end vertebra (P < 0.05). The difference of the proliferative potential index and apoptosis index were found significant statistically in the concave side of the vertebral growth plate between end vertebrae and apex vertebrae (P < 0.05). The same result was also found for the apoptosis index (terminal deoxynucleotidyl transferase mediated deoxyuridine triphosphate biotin nick end labeling assay, TUNEL index) in the convex side of vertebral growth plate between end vertebrae and apex vertebrae (P < 0.05). Some correlation were found between radiographic measurements and proliferation and apoptosis indexes. The difference in histological grades and cellular activity between the convex and concave side indicated that the bilateral growth plate of the vertebrae in AIS patients have different growth kinetics which may affect the curve progression

Infant colic and feeding difficulties

Aims: To examine the relation between colic and feeding difficulties and their impact on parental functioning for a primarily clinic referred sample. Methods: Forty three infants (and their mothers) were enrolled between 6 and 8 weeks of age. Infants were divided into two groups, colic (n = 19) and comparison (n = 24), based on a modified Wessel rule of three criteria for colic. Families were assessed at two visits; one occurred in the laboratory and one occurred in a paediatric radiology office. Outcome measures included the clinical assessment of infant oral motor skills, behavioural observation of mother-infant feeding interactions, maternal questionnaires on infant crying, sleeping and feeding behaviours, and the occurrence of gastro-oesophageal reflux (GOR) in the infants using abdominal ultrasound. Results: Infants in the colic group displayed more difficulties with feeding; including disorganised feeding behaviours, less rhythmic nutritive and non-nutritive sucking, more discomfort following feedings, and lower responsiveness during feeding interactions. Infants in the colic group also had more evidence of GOR based on the number of reflux episodes on abdominal ultrasound as well as maternal report of reflux. Mothers in the colic group reported higher levels of parenting stress. Conclusions: Results provide the first systematic evidence of feeding problems in a subgroup of infants with colic. Data also illustrate the impact of these difficulties on parental and infant functioning. The association between feeding difficulties and colic suggests the potential for ongoing regulatory problems in infants presenting with clinically significant colic symptoms

Probiotics for infantile colic: a systematic review

BACKGROUND: Infantile colic is a common paediatric condition which causes significant parental distress. Increased intestinal coliform colonization in addition to alteration in Lactobacillus abundance and distribution may play an important role in its pathogenesis. The objectives of this systematic review are to evaluate the efficacy of probiotic supplementation in the reduction of crying time and successful treatment of infantile colic. METHODS: Literature searches were conducted of MEDLINE, EMBASE and the Cochrane Central Register of Controlled Trials. Only randomized controlled trials enrolling term, healthy infants with colic were included. A meta-analysis of included trials was performed utilizing the Cochrane Collaboration methodology. RESULTS: Three trials that enrolled 220 breastfed infants met inclusion criteria, of which 209 infants were available for analysis. Two of the studies were assessed as good quality. Lactobacillus reuteri (strains-American Type Culture Collection Strain 55730 and DSM 17 938) was the only species utilized in the therapeutic intervention. Two of the trials were industry funded. Probiotic supplementation compared to simethicone or placebo significantly and progressively shortened crying times to 7 days reaching a plateau at three weeks post initiation of therapy [mean difference −56.03 minutes; 95% CI (−59.92, -52.15)]. Similarly, probiotics compared to placebo significantly increased the treatment success of infantile colic with a relative risk (RR) of 0.06; 95% CI (0.01, 0.25) and a number needed to treat of 2. CONCLUSIONS: Although L. reuteri may be effective as a treatment strategy for crying in exclusively breastfed infants with colic, the evidence supporting probiotic use for the treatment of infant colic or crying in formula-fed infants remains unresolved. Results from larger rigorously designed studies will help draw more definitive conclusions

Child Care Health Dev

BACKGROUND: Parenting stress is influenced by many factors including maternal attachment and excessive infant crying, yet the nature of these relationships is not well understood. For example, excessive infant crying despite maternal soothing may impact maternal attachment to the child, leading to higher stress. This paper explored whether maternal perception of excessive infant crying at six months was associated with higher maternal parenting stress at 24 months, and whether maternal attachment mediated this relationship. METHODS: All families, present at 24 months in a randomized controlled trial of a five-year early intervention program targeting school readiness skills in disadvantaged area of Ireland, were included. At six months, infant crying was assessed using a maternal reported measure of duration of infant crying and maternal attachment to the infant was assessed using the Condon Maternal Attachment Scale. Parenting stress was assessed at 24 months using the childrearing stress subscale from the Parenting Stress Index. Structural Equation Modelling was used to explore the direct and indirect effects of maternal perceptions of excessive infant crying on parenting stress, controlling for infant, maternal, and environmental characteristics, focusing on the mediating role of maternal attachment. RESULTS: Reporting excessive infant crying at six months was associated with lower maternal attachment at six months, which led to higher parenting stress at 24 months. In addition, vulnerable adult attachment style, previous maternal mental health difficulties, low paternal education, paternal involvement with the child, and not being married were associated with higher parenting stress. CONCLUSION: Findings suggest that the association between maternal perceptions of excessive crying at six months and later parenting stress may be mediated through maternal attachment to the infant. Interventions based on improving maternal attachment could be investigated to determine the effectiveness of supporting mothers with low attachment