Current Pediatric Reviews

ISSN: 1573-3963

Current Pediatric Reviews
Volume 4, Number 1, February 2008

Contents


Editorial Pp. 1


Pathophysiology and Prevention of Bronchopulmonary Dysplasia Pp. 2-14
Jonathan W. Davis and David G. Sweet
[Abstract]


Congenital Duodenal Obstruction: The Impact of Down’s Syndrome in Neonatal Morbidity. A Two-Center Su Pp.15-18
Marcelo E. Miranda, Daniel G. Bittencourt, Joaquim M. Bustorff Silva, Bernardo A. Campos, Edson S. Tatsuo and Lourenço Sbragia
[Abstract]


A Comprehensive Update on Congenital Glaucoma Pp. 19-30
Thasarat S. Vajaranant, Sami Al-Shahwan, Bassem A. Bejjan and Deepak P. Edward
[Abstract]


Sudden Infant Death Syndrome: A Review of the Literature Pp. 31-39
Olanrewaju O. Omojokun and Rachel Y. Moon
[Abstract]


The Fragile X Family of Disorders: A Model for Autism and Targeted Treatments Pp. 40-52
Randi J. Hagerman, Susan M. Rivera and Paul J. Hagerman
[Abstract]


Early Communication Skills; Important in Screening for Language Impairment and Neuropsychiatric Disorders Pp. 53-57
Barbro Bruce and Kristina Hansson
[Abstract]


New Insights into the Pathogenesis of and Long-Term Risks in Children with Henoch-Schönlein Purpura\ Nephritis Pp. 58-65
Keith K. Lau and Lavjay Butani
[Abstract]




Abstracts


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Editorial

Bronchopulmonary dysplasia (BPD) is a common adverse outcome of premature birth, affecting approximately 40% of those born prior to 29 weeks of gestation. It has long term adverse consequences including recurrent respiratory symptoms requiring treatment and lung function abnormalities at school age and adolescence. In this issue, Drs. Davis and Sweet highlight that BPD is caused by a combination of insults on the developing lung precipitated by preterm birth and its subsequent respiratory management. In particular, they note the common pathway linking the various causative factors is inflammation which, in the developing lung, induces airway remodelling with an adverse effect on lung function. They emphasize that management should be directed towards prevention with strategies aimed at minimising early lung injury and oxidative stress, including delivery room stabilisation and mechanical ventilation techniques that aim to avoid volutrauma and atelecto-trauma. Meta-analysis of randomised trials of “invasive” ventilation has demonstrated that only prophylactic high frequency oscillation is associated with a reduction in BPD, but the effect is modest and inconsistent across the fifteen trials included in the Cochrane review. Over the first year after birth, studies have demonstrated lung function deterioration in prematurely born infants. Results of a non-randomised study suggest this may be avoided by use of prophylactic HFO. Yet certain trials have demonstrated use of HFO may increase short term neurological complications. It is therefore essential that there is long term follow up of infants entered into such trials and hence the real risk benefit ratio of this ventilation mode can be determined.

Sudden infant death syndrome (SIDS) remains the leading cause of postnatal deaths in the United States. Prematurely born infants have an increased risk of SIDS, particularly if slept prone (odds radio of over 40) and also if their mothers smoked during pregnancy. In this issue Drs. Omojokun and Moon have reviewed the evidence for the pathophysiology of SIDS and maternal risk factors. They highlight that recent data have demonstrated associations between SIDS and specific polymorphisms, including genes involved in the autonomic system development, cardiac ion channels and infection, inflammation and metabolism. They suggest that the interaction between environmental and genetic factors contributes to SIDS susceptibility.


Prof. Anne Greenough
King’s College London, MRC-Asthma Centre
Division of Asthma, Allergy and Lung Biology
King’s College Hospital, Denmark Hill
London, SE5 9RS
UK
E-mail: anne.greenough@kcl.ac.uk


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Pathophysiology and Prevention of Bronchopulmonary Dysplasia
Jonathan W. Davis and David G. Sweet

BPD is the major respiratory complication of preterm delivery and is typified by chronic oxygen dependency and respiratory insufficiency beyond 36 weeks’ postconceptional age. It is caused by a combination of insults on the developing lung precipitated by preterm birth and its subsequent respiratory management. The common pathway linking the various causative factors is inflammation, which may be initiated prior to birth in the setting of maternal chorioamnionitis, or after birth by mechanical ventilation, infection or oxidative stress. Inflammation in the developing lung induces airways remodeling which adversely affects lung function. Multiple inflammatory mediators are implicated in this process and modifying the course of the disease has proven difficult. The emphasis of management should be directed towards prevention with strategies aimed at minimizing early lung injury and oxidative stress. These include delivery room stabilization and mechanical ventilation techniques that aim to avoid volutrauma and atelectotrauma. Drugs may also influence BPD progression and can broadly be divided into three categories; those administered prenatally to accelerate lung maturation, those administered postnatally to reduce initiation of inflammatory stimuli and those to modify any established inflammatory response. In this review we have examined recent evidence for each of these ventilatory and therapeutic strategies to prevent BPD. A better understanding of the pathophysiology of airways remodeling in BPD could have significant implications for future potential targeted interventions.


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Congenital Duodenal Obstruction: The Impact of Down’s Syndrome in Neonatal Morbidity. A Two-Center Survey
Marcelo E. Miranda, Daniel G. Bittencourt, Joaquim M. Bustorff Silva, Bernardo A. Campos, Edson S. Tatsuo and Lourenço Sbragia

Background/Purpose: Babies with congenital duodenal obstruction (CDO) have a high incidence of additional anomalies. Down’s syndrome (DS) is the most common associated chromosomal defect, affecting up to 20% of these newborns. Morbidity is expected to be higher in DS patients, since it is a major cause of congenital heart disease, immunodeficiency, and other birth defects. We could find only one report concerning the morbidity in the DS newborn, when associated with CDO. The purpose of this report is to compare the postoperative outcome of two groups of newborns with CDO: group I, patients with associated DS and group II, without DS.

Methods: A two-center retrospective review of charts of 46 newborns with CDO admitted to the Hospital of “UNICAMP” and the “Hospital das Clínicas da UFMG”, between 1993 and 2001, was undertaken.

Results: Sixteen (34,7%) of the 46 babies had DS. The groups were homogeneous concerning gestational age, gender, birth weight and nutritional status. There was a higher incidence of cardiopathy (56% x 20%) and sepsis (37% x 16%) among patients with DS; however we could find statistic difference only for the incidence of cardiopathy. The survival rate was similar for both groups, reaching 94%.

Conclusions: Despite the associated anomalies, newborns with DS individuals had a similar postoperative course, when compared with babies without DS after surgical correction of CDO. The earlier diagnosis of CDO and other birth defects, associated with intensive care, appropriate surgical procedure and postoperative support can provide an equivalent morbidity for DS patients.


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A Comprehensive Update on Congenital Glaucoma
Thasarat S. Vajaranant, Sami Al-Shahwan, Bassem A. Bejjani and Deepak P. Edward

Congenital glaucoma is a broad group of disorders that present with elevated intraocular pressure in children. Pediatricians and family physicians have significant roles in diagnosing the condition in its early stages. The disorder is infrequent but can be a sight threatening condition or even life threatening when associated with certain systemic conditions. The reported incidence of the condition is variable and more prevalent in certain parts of the world. This review will discuss updates on the classification of congenital glaucoma, the role of genetics in this disorder, and current concepts of the pathogenesis of the disease. In addition, the clinical signs and symptoms of the disease as well as ophthalmic and systemic workup will be reviewed. This review will also describe current medical and surgical treatment, and visual outcomes. In addition, the importance of long-term visual rehabilitation and the role of the pediatrician or other primary care provider in this process will be emphasized.


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Sudden Infant Death Syndrome: A Review of the Literature
Olanrewaju O. Omojokun and Rachel Y. Moon

Sudden Infant Death Syndrome (SIDS) is characterized by the sudden death of an infant, unexpected by history and unexplained by a postmortem exam. The rate of SIDS has decreased markedly since the launch of the Back to Sleep campaign and other public health initiatives. Despite these efforts, SIDS remains the third leading cause of infant death and the leading cause of postneonatal deaths in the United States. The cause of SIDS is unknown, but autopsies have suggested that asphyxia and central nervous system abnormalities, among other findings, may play a role. Environmental risk factors, such as maternal smoking and infant sleep position, are multifactorial and documented throughout the medical literature. The influence of genetics on SIDS risk is not as well-understood at this time, but recent data have demonstrated associations between specific polymorphisms and SIDS, suggesting that interactions among environmental and genetic factors contribute to SIDS susceptibility. Recent data regarding the protective effects of pacifiers and breastfeeding are discussed. Risk reduction guidelines for physicians, parents, and other caretakers are outlined in this review of the literature, with particular emphasis on the 2005 recommendations from the American Academy of Pediatrics.


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The Fragile X Family of Disorders: A Model for Autism and Targeted Treatments
Randi J. Hagerman, Susan M. Rivera and Paul J. Hagerman

CGG-repeat expansion mutations of the fragile X mental retardation 1 (FMR1) gene are the leading known cause of autism and autism spectrum disorders (ASD). Full mutation expansions (>200 CGG repeats) of the gene are generally silenced, resulting in absence of the FMR1 protein and fragile X syndrome. By contrast, smaller expansions in the premutation range (55-200 CGG repeats) result in excess gene activity and RNA toxicity, which is responsible for the neurodegenerative disorder, fragile X-associated tremor/ataxia syndrome (FXTAS), and likely additional cases of developmental delay and autism. Thus, the FMR1 gene is causative of a common (autism) phenotype via two entirely different pathogenic mechanisms, RNA toxicity and gene silencing. The study of this gene and its pathogenic mechanisms therefore represents a paradigm for understanding gene-brain relationships and the means by which diverse genetic mechanisms can give rise to a common behavioral phenotype.


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Early Communication Skills; Important in Screening for Language Impairment and Neuropsychiatric Disorders
Barbro Bruce and Kristina Hansson

Communication skills during social interaction at 18 months’ age, such as comprehension of instructions and play behaviour, have been shown to predict the results on language tests three years later. Accordingly, children with weak communication skills are at risk for persistent problems of language and communication. Problems of communication in social interaction are also common in children with neuropsychiatric disorders, such as ADHD (attention deficit hyperactivity disorder) and ASD (autism spectrum disorder). For different reasons, it is important to identify children who are at risk for language impairment and neuropsychiatric disorders at as an early age as possible. First, early identification allows early intervention, which may increase the chances of a positive outcome for the child. Second, early identification may decrease the risk of secondary problems with behaviour, and social and emotional wellbeing, which are frequently occurring in children with neuropsychiatric disorders. This paper is an overview of the literature focusing on the importance of early communication skills, i.e. language use in a social interaction context. Conclusion: Early communication skills in social interaction are a possible predictor of language impairment and neuropsychiatric disorders, and should therefore be included in early screening procedures. Furthermore, social interaction enhances language development, and can therefore be regarded as a tool in language intervention.


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New Insights into the Pathogenesis of and Long-Term Risks in Children with Henoch-Schönlein Purpura Nephritis
Keith K. Lau and Lavjay Butani

Renal involvement is the major factor determining the long-term outcome of children with Henoch-Schönlein Purpura (HSP) nephritis. The precise incidence of adverse outcomes is debatable; moreover, there are conflicting data on the validity of prognostic factors for predicting adverse outcome in children with HSP nephritis. Difficulties in prognostication are compounded by lack of non-invasive diagnostic methods in children suspected of having HSP. The purpose of this article is to review recent data evaluating the role of serum galactose-deficient IgA in the pathogenesis of HSP nephritis and its potential role as a non-invasive diagnostic tool. Recent studies evaluating the role of prognostic markers and the risk of adverse long-term outcomes in children with HSP nephritis are also described. HSP nephritis, although relatively benign in most children, can lead to significant chronic kidney disease in a subset of children, especially on very long-term follow-up. Health-care providers need to be aware of this and tailor appropriate follow-up and screening tests to identify early signs of renal functional deterioration, so that therapies that can retard the rate of progression can be instituted early.