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PubMed2004

Systemic antifungal drugs for invasive fungal infection in preterm infants.

BACKGROUND: Invasive fungal infection is an increasingly common cause of mortality and morbidity in preterm infants. In addition to amphotericin B, a variety of newer antifungal drugs and drug preparations are available for treatment. There is a need to assess their relative merits. OBJECTIVES: In preterm infants with suspected or confirmed invasive fungal infection, does treatment with newer systemic antifungal drugs or drug preparations, versus conventional amphotericin B alone, reduce mortality and adverse neurodevelopmental outcomes? SEARCH STRATEGY: We used the standard search strategy of the Cochrane Neonatal Review Group. This included searches of the Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library, Issue 3, 2003), MEDLINE (1966 - August 2003), EMBASE (1980 - August 2003), conference proceedings, and previous reviews. SELECTION CRITERIA: Randomised and quasi-randomised control trials comparing one antifungal agent or combination of agents with another in preterm infants with suspected or confirmed invasive fungal infection. DATA COLLECTION AND ANALYSIS: We extracted the data using the standard methods of the Cochrane Neonatal Review Group, with separate evaluation of trial quality and data extraction by each author, and synthesis of data using relative risk and risk difference. The pre-specified outcomes were death prior to hospital discharge, longer term neurodevelopment, and adverse drug reactions resulting in discontinuation of therapy. MAIN RESULTS: We identified only one small trial. This study compared the use of fluconazole with amphotericin B (5-Fluorocytosine added if fungal meningitis present). Three of 11 infants who were treated with fluconazole died and four of 10 infants who were treated with amphotericin B died : Relative risk: 0.68 (95% confidence interval 0.20, 2.33), Risk Difference -0.13 (95% confidence interval -0.53, 0.27) There were not any data on longer term outcomes. REVIEWER'S CONCLUSIONS: From this one small study there are insufficient data to favour one antifungal agent or combination to reduce mortality and adverse neurodevelopmental outcomes in preterm infants with suspected or confirmed invasive fungal infection. A large randomised controlled trial is required to compare the newer antifungal preparations with conventional amphotericin B. Further research may also determine the relative convenience and cost effectiveness of the available drugs.

Amphotericin B↗

PubMed2006

Single versus double volume exchange transfusion in jaundiced newborn infants.

BACKGROUND: Double volume exchange transfusion is commonly used in newborns with severe jaundice in order to prevent kernicterus and other toxicity related to hyperbilirubinemia. Most commonly, exchange transfusions are used in infants with rhesus hemolytic disease. OBJECTIVES: To compare the effectiveness of single volume exchange transfusion (SVET) with that of double volume exchange transfusion (DVET) in producing survival without disability and reducing bilirubin levels in newborn infants with severe jaundice. SEARCH STRATEGY: MEDLINE, EMBASE (Excerpta Medica online), The Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library), SCISEARCH (Science Citation Index), Reference lists from the articles identified in the search of the databases, and from review articles were searched through March 2006. Personal communication with experts in the field was used to identify unpublished data. SELECTION CRITERIA: All Randomised and quasi randomised control trials comparing single volume and double volume exchange transfusions in jaundiced newborn infants were included. DATA COLLECTION AND ANALYSIS: Safety and efficacy of single and double volume exchange compared with regards to long term neurodevelopment, reduction in bilirubin levels and other complications during exchange transfusion. Data was evaluated separately with regards to the cause of jaundice. Relative risk (RR) and weighted mean difference (WMD) were calculated for dichotomous and continuous variables respectively. 95% confidence intervals were used and a fixed effects model was assumed. MAIN RESULTS: Only one study fulfilled the criteria (Amato 1988). 20 full term babies requiring exchange transfusion for hemolytic jaundice due to ABO incompatibility were randomly allocated to receive single or double volume exchange transfusion. Base line characteristics of both groups were similar with regards to birth weight 3260 (SD 390) g vs. 3350 SD (410) g, gestational age 39 (SD 1) week vs. 40 (SD 0.8) week, immediate pre exchange bilirubin level 199 (SD 33) micromol/L vs. 216 (SD 55) micromol/L. Both groups were treated equally apart from the volume of blood used for exchange transfusion. Total bilirubin levels immediately after exchange transfusion were not significantly different in either group. No long term neurodevelopmental outcome was examined in this study. AUTHORS' CONCLUSIONS: There was insufficient evidence to support or refute the use of single volume exchange transfusion as opposed to double volume exchange transfusion in jaundiced newborns. A change from the current practice of double volume exchange transfusions for severe jaundice in newborns infant, cannot be recommended on current evidence.

Bilirubin↗

PubMed2005

Calorie and protein-enriched formula versus standard term formula for improving growth and development in preterm or low birth weight infants following hospital discharge.

BACKGROUND: Preterm and low birth weight infants are often growth-restricted at hospital discharge. Feeding infants post-hospital discharge with calorie and protein-enriched formula milk might facilitate "catch-up" growth and improve development. OBJECTIVES: To review the evidence from randomised controlled trials that feeding following hospital discharge with calorie and protein-enriched formula compared with standard term formula improves growth and development for preterm or low birth weight infants. SEARCH STRATEGY: We used the standard search strategy of the Cochrane Neonatal Review Group. This included searches of the Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library, Issue 4, 2004), MEDLINE (1966 - December 2004), EMBASE (1980 - December 2004), CINAHL (1982 - December 2004), conference proceedings, and previous reviews. SELECTION CRITERIA: Randomised or quasi-randomised controlled trials that compared the effect of feeding preterm or low birth weight infants post-hospital discharge with calorie and protein-enriched formula compared with standard term formula. DATA COLLECTION AND ANALYSIS: We extracted data using the standard methods of the Cochrane Neonatal Review Group, with separate evaluation of trial quality and data extraction by two authors, and synthesis of data using weighted mean difference and a fixed effects model for meta-analysis. MAIN RESULTS: We found six trials that were eligible for inclusion. These recruited a total of 424 infants and were generally of good methodological quality. These trials found little evidence that feeding with calorie and protein-enriched formula milk affected growth and development. Because of differences in the way individual trials measured and presented outcomes, data synthesis was limited. Meta-analysis of data from two trials found a statistically significant effect on crown-heel length at 18 months post-term (weighted mean difference 9.7 millimetres (95% confidence interval 3.2 to 16.2)), but not on weight or head circumference. Meta-analysis of data from the two trials that assessed neurodevelopment at 18 months post-term did not reveal a statistically significant difference in either Bayley Mental Development Index (weighted mean difference 0.23 (95% confidence interval -2.99 to 3.45)) or Psychomotor Development Index (weighted mean difference 0.56 (95% confidence interval -1.95 to 3.07)). There are not yet any data on growth or development through later childhood. AUTHORS' CONCLUSIONS: The limited available data do not provide strong evidence that feeding preterm or low birth weight infants following hospital discharge with calorie and protein-enriched formula compared with standard term formula affects growth rates or development up to 18 months post-term.

Child Development↗

PubMed2006

Increased energy intake for preterm infants with (or developing) bronchopulmonary dysplasia/ chronic lung disease.

BACKGROUND: Preterm infants with bronchopulmonary dysplasia/chronic lung disease have nutritional deficits that may contribute to short and long term morbidity and mortality. Increasing the daily energy intake for these infants may improve their respiratory, growth and neurodevelopmental outcomes. OBJECTIVES: To assess the effect of increased energy intake on mortality and respiratory, growth and neurodevelopmental outcomes for preterm infants with (or developing) CLD/BPD. Secondarily, the review examines any adverse effects associated with increased energy intake. SEARCH STRATEGY: The standard search strategy of the Cochrane Neonatal Review Group was used. This included searches of the Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library, Issue 1, 2006) , MEDLINE (accessed via Ovid), references cited in previous relevant Cochrane reviews and in other relevant studies, review articles, standard textbooks, and manuals of neonatal medicine. Hand search results of the Cochrane Neonatal Review Group were also assessed. SELECTION CRITERIA: All randomized and quasi-randomized trials comparing the outcomes of preterm infants with (or developing) CLD/BPD who had either increased (> 135 kcal/kg/day) or standard energy intake (98 to 135 kcal/kg/day). Increasing energy intake might be achieved enterally and/or parenterally, enterally by increasing the energy content of the milk, increasing feed volume, or by nutrient supplementation with protein, carbohydrate or fat. The primary outcomes were the development of CLD and neonatal mortality; secondary outcomes included respiratory morbidities, growth, neurodevelopmental status and possible complications with increased energy intake. DATA COLLECTION AND ANALYSIS: We planned to extract data using the standard methods of the Cochrane Neonatal Review Group. Relevant trials would be scrutinized for methodological quality independently by the reviewers to determine their eligibility for inclusion. Data of the included trials would be expressed as relative risk, risk difference, NNT and weighted mean difference where appropriate, using a fixed effect model. MAIN RESULTS: No eligible trials were identified. Twelve studies that appeared to be relevant were excluded, as no study directly compared increased versus standard energy intakes in infants with CLD/BPD. However, two excluded trials provided some insights into the topic. One study showed that infants with CLD/BPD who were fed formula enriched with protein and minerals had improved growth parameters up until the cessation of the intervention at three months of corrected age. The other study compared different energy density of formula but identical energy intake by setting different feed volumes for both groups. It showed that both groups were unable to achieve the pre-designated feed volumes, and that there were no differences in growth, respiratory outcomes, oedema and the diuretic requirements. AUTHORS' CONCLUSIONS: To date, no randomized controlled trials are available that examine the effects of increased versus standard energy intake for preterm infants with (or developing) CLD/BPD. Research should be directed at evaluating the effects of various levels of energy intake on this group of infants on clinically important outcomes like mortality, respiratory status, growth and neurodevelopment. The benefits and harms of various ways of increasing energy intake, including higher energy density of milk feed and/or fluid volume (clinically realistic target volume should be set), parenteral nutrition, and the use of various constituents of energy like carbohydrate, protein and fat for this purpose also need to be assessed.

Bronchopulmonary Dysplasia↗

PubMed2006

Iodine supplementation for the prevention of mortality and adverse neurodevelopmental outcomes in preterm infants.

BACKGROUND: Parenteral nutrition solutions, formula milks, and human breast milk contain insufficient iodine to meet recommended intakes for preterm infants. Iodine deficiency may exacerbate transient hypothyroxinaemia in preterm infants and this may be associated with adverse respiratory or neurological outcomes. OBJECTIVES: To assess the evidence from randomised controlled trials that dietary supplementation with iodine reduces mortality and morbidity in preterm infants. SEARCH STRATEGY: We used the standard search strategy of the Cochrane Neonatal Review Group. This included searches of the Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library, Issue 4, 2005), MEDLINE (1966 - November 2005), EMBASE (1980 - November 2005), CINAHL (1982 - November 2005), conference proceedings, and previous reviews. SELECTION CRITERIA: Randomised or quasi-randomised controlled trials that compared a policy of supplementing enteral or parenteral feeds with iodine (more than 30 micrograms per kilogram per day) versus placebo or no supplementation in preterm infants. DATA COLLECTION AND ANALYSIS: The standard methods of the Cochrane Neonatal Review Group, with separate evaluation of trial quality and data extraction by two reviewers, and synthesis of data using relative risk, risk difference and weighted mean difference. The primary outcomes for this review were neonatal mortality, death before hospital discharge, and longer term neurodevelopmental outcomes including severe neurodevelopmental disability. MAIN RESULTS: We found only one randomised controlled trial (N = 121) that fulfilled the review eligibility criteria (Rogahn 2000). The participants were infants born before 33 weeks' gestation (but most were of birth weight greater than 1000 grams). The primary aim of this trial was to assess the effect of iodine supplementation on thyroid function. The investigators did not detect any statistically significant effects on the plasma levels of thyroxine (free and total), triiodothyronine, or thyrotrophin in preterm infants (measured up to 40 weeks' post-conceptional age). Only one infant died and the trial was therefore underpowered to detect an effect on mortality. The trial did not assess the effect of the intervention on neurodevelopmental morbidity. There was not a statistically significant difference in the incidence of chronic lung disease. AUTHORS' CONCLUSIONS: There are insufficient data at present to determine whether providing preterm infants with supplemental iodine (to match fetal accretion rates) prevents morbidity and mortality in preterm infants. Future randomised controlled trials of iodine supplementation should focus on extremely preterm and extremely low birth weight infants, the group at greatest risk of transient hypothyroxinaemia. These trials should aim to assess the effect of iodine supplementation on clinically important outcomes including respiratory morbidity and longer term neurodevelopment.

Developmental Disabilities↗

PubMed1991

Fetal brain development and later schizophrenia.

Computed tomography and magnetic resonance imaging studies have shown cerebral ventricular enlargement and a decreased volume of temporal lobe structures in a proportion of schizophrenic patients. Neuropathological investigations confirm these findings and also show diminished volume of the hippocampus and abnormal pre-alpha cell clusters in the parahippocampal gyrus. Compared with controls, schizophrenic patients are more likely to have minor physical anomalies, to have a history of obstetric complications, and to have been born in the late winter. Together the evidence regarding structural brain abnormalities and epidemiology suggests that a significant proportion of cases of schizophrenia have their origins in fetal or neonatal life. The mechanisms involved in the aberrant neurodevelopment remain obscure but some impairment of neuronal migration is an appealing hypothesis.

Brain↗

PubMed1993

Schizophrenia: genetics and the maternal immune response to viral infection.

Thirty years ago, Eliot Slater suggested that the reason schizophrenia was not progressively eliminated from the population was that the responsible gene also conveyed a compensatory advantage in terms of increased resistance to infection. If this selective advantage lies in the antibody response to certain viral infections, this could explain recent studies suggesting that exposure to influenza in the second trimester of gestation increases the risk of later schizophrenia. We propose that prenatal exposure to influenza induces maternal antibodies which then cross-react with proteins in the developing foetal brain, becoming foetal autoantibodies. Thus an immunogenetic response by the mother results in aberrant foetal neurodevelopment, the biological substrate for a proportion of adult schizophrenia. Initial research strategies to test this hypothesis are proposed.

Antibodies, Viral↗

PubMed2005

Joubert syndrome is not a cause of classical autism.

A previous report noted a 27% prevalence of autism in Joubert syndrome (JS), raising the question of overlapping etiologies. Family studies have shown that autism is characterized by family loading for a number of specific behavioral and psychiatric disorders and that the sib recurrence risk is around 4%. The purpose of this study is to determine whether children with Joubert and their families show behavioral or genetic characteristics similar to autism. Thirty-one volunteer Joubert families were identified. Parents completed a semi-structured family history interview and the Autism Behavioral Checklist. Rates of family loading for neuropsychiatric disorders in the JS families were compared to autism family history data and Down syndrome (DS) controls. The JS families had significantly lower rates of autism, alcoholism, cognitive, and language disorders than the autism families. Their rate of depression was lower, but not significantly different from that found in autism families. None of the JS children met the clinical cut-off for autism based on parental symptom report and the sib recurrence risk was 32% for the JS families compared to 4% for the autism and 0% for DS families. These data indicate that JS is a genetically distinct disorder from autism. Different genes with different inheritance patterns that affect neurodevelopment of the cerebellum could explain the clinical similarities previously reported in JS and autism.

Abnormalities, Multiple↗

PubMed2004

Lack of evidence for an association between WNT2 and RELN polymorphisms and autism.

Autism is a pervasive neurodevelopmental disorder characterized by deficits in language development and social interaction, as well as stereotypical, repetitive behaviors. The etiology of autism is largely unknown. Family and twin studies have provided compelling evidence for a strong genetic component in most idiopathic cases. Several recent candidate gene studies have suggested that alleles of WNT2 and the reelin gene (RELN), two genes involved in distinct aspects of neurodevelopment, confer greater susceptibility to autism. We screened WNT2 for DNA polymorphisms by sequencing all exons and adjacent intronic regions in 24 autistic patients, and identified not only the WNT2 variants reported previously (two common single-nucleotide polymorphisms (SNPs) in the 5' upstream region and the 3' untranslated region (UTR), respectively), but also two new SNPs in its 3' UTR. We genotyped all four WNT2 polymorphisms and a polymorphic trinucleotide repeat in the 5' UTR of RELN in 107 families with multiple autistic children, and evaluated evidence for association between these variants and autism by the transmission disequilibrium test (TDT). Our results revealed no deviation from the null hypothesis of no association. Our interpretation of these findings is that it is unlikely that DNA variations in RELN and WNT2 play a significant role in the genetic predisposition to autism.

5' Untranslated Regions↗

PubMed2005

A meta-analysis of the MTHFR C677T polymorphism and schizophrenia risk.

Epigenetic mechanisms such as methylation of DNA, could lead to abnormal neurodevelopment and may be important in the etiology of schizophrenia. Maternal dietary folate intake may play a role in determining methylation levels. The MTHFR gene C677T polymorphism influences folate metabolism and intracellular availability of folate metabolites for methylation. We carried out a meta-analysis of MTHFR C677T genotype and schizophrenia risk, and found that TT homozygotes had a significantly increased risk, OR 1.48 (1.18-1.86). This supports the hypothesis that folate status is a determinant of schizophrenia risk. Larger studies of this issue are required, together with studies of maternal genotype which could identify whether maternal folate status during pregnancy is important.

Alleles↗

PubMed2007

Schizophrenia is not associated with the functional candidate gene ERBB3: results from a case-control study.

Increasing evidence has supported the hypothesis of a neurodevelopmental component in the etiology of schizophrenia. Recently, several independent microarray gene expression studies have revealed downregulated expression of myelin-related genes in the postmortem brains of schizophrenia patients. Complete myelination of the cortex has been observed to occur in late adolescence and early adulthood, which is typically the age of onset of schizophrenia. ERBB3 is a gene which has not only been found to be downregulated in schizophrenia simultaneously in three microarray studies, but also is a strong candidate because of its potential role in neurodevelopment as a receptor of NRG1. Therefore, we performed association analysis of seven nonsynonymous SNPs in this gene. Two SNPs in ERBB3 (rs773123 and rs2271188) were polymorphic in our samples, neither of which showed significant evidence of association with the illness (P = 0.639 and 0.561, respectively). Because replication across such studies is notoriously difficult, the microarray evidence implicating ERBB3 still strongly supports some role of this gene in schizophrenia. However, our failure to find genetic association suggests that the differential expression of ERBB3 in schizophrenia may be environmentally driven, or involve cis- or trans-acting genetic factors beyond the boundaries of the gene itself.

Adolescent↗

PubMed2004

The interleukin 1beta gene promoter polymorphism (-511) acts as a risk factor for psychosis in Alzheimer's dementia.

The explanation for why some patients develop psychotic change in Alzheimer's disease (AD) is unclear. "Psychosis-modifier genes" may act in the setting of neurodegeneration to produce AD plus psychosis in a similar way to how genetic modulation during neurodevelopment leads to schizophrenia. Because there is increasing interest in the common disruption of cytokine pathways seen in both AD and schizophrenia, we tested the association between the functional interleukin-1beta -511 promoter polymorphism with delusions and hallucinations in AD. Significant associations between psychotic symptoms and the CC genotype (p = 0.001 - p = 0.043) and C allele (p = 0.014 vs p = 0.048) were found, thus confirming the previously noted increased risk in schizophrenia.

Aged↗

PubMed1987

Positron emission tomography study of human brain functional development.

From over 100 children studied with 2-deoxy-2[18F]fluoro-D-glucose and positron emission tomography we selected 29 children (aged 5 days to 15.1 years) who had suffered transient neurological events not significantly affecting normal neurodevelopment. These 29 children were reasonably representative of normal children and provided an otherwise unobtainable population in which to study developmental changes in local cerebral metabolic rates for glucose (lCMRGlc). In infants less than 5 weeks old lCMRGlc was highest in sensorimotor cortex, thalamus, brainstem, and cerebellar vermis. By 3 months, lCMRGlc had increased in parietal, temporal, and occipital cortices; basal ganglia; and cerebellar cortex. Frontal and dorsolateral occipital cortical regions displayed a maturational rise in lCMRGlc by approximately 6 to 8 months. Absolute values of lCMRGlc for various grey matter regions were low at birth (13 to 25 mumol/min/100 gm), and rapidly rose to reach adult values (19 to 33 mumol/min/100 gm) by 2 years. lCMRGlc continued to rise until, by 3 to 4 years, it reached values of 49 to 65 mumol/min/100 gm in most regions. These high rates were maintained until approximately 9 years, when they began to decline, and reached adult rates again by the latter part of the second decade. The highest increases of lCMRGlc over adult values occurred in cerebral cortical structures; lesser increases were seen in subcortical structures and in the cerebellum. This time course of lCMRGlc changes matches that describing the process of initial overproduction and subsequent elimination of excessive neurons, synapses, and dendritic spines known to occur in the developing brain. The determination of changing metabolic patterns accompanying normal brain development is a necessary prelude to the study of abnormal brain development with positron emission tomography.

Adolescent↗

PubMed1993

The effects of X monosomy on brain development: monozygotic twins discordant for Turner's syndrome.

Monosomy for the X chromosome is the most frequent cause of Turner's syndrome, a common clinical syndrome associated with particular physical and neurobehavioral features. The results from comprehensive assessment of prepubertal monozygotic female twins discordant for X monosomy are presented. Zygosity was established with DNA Fingerprinting and no evidence of chromosomal mosaicism was seen in either child. Physical features in the affected twin were relatively mild with respect to the full spectrum of physical malformations and disabilities associated with Turner's syndrome. The neurobehavioral phenotypes of the twins were compared. Although both sisters scored in the superior range of intelligence, the affected twin's Performance IQ was 18 points less than her sister, whereas Verbal IQ showed only a 3-point difference between the sisters. Other relative differences were noted within the executive, visuospatial, and visuomotor domains of function. Behavioral evaluation indicated greater problems with attention, hyperactivity, and anxiety in the affected twin. Quantitative analysis of brain anatomy revealed evidence of both general and regional effects of X monosomy on neurodevelopment. Cerebrospinal fluid volume was increased by 25% in the affected twin compared with her sister with a corresponding decrease in gray matter volume. The right frontal, right parietal-occipital, and left parietal-perisylvian regions showed the greatest discrepancy between the sisters with respect to increased cerebrospinal fluid and decreased gray matter volumes in twin with X monosomy. Differences in the posterior fossa were also noted with a 50% relative increase in the volumes of the fourth ventricle and cisterna magna and a 10 to 15% relative reduction in size of the cerebellar vermis, pons, and medulla in the affected twin. The association between the neurobehavioral and neuroanatomical findings in the affected twin is discussed. The unique nature of the naturally occurring genetic phenomenon seen in this twin pair provides an opportunity to more fully elucidate the neurobehavioral phenotype associated with X monosomy and Turner's syndrome.

Brain↗

PubMed1993

Neuroanatomy of Rett syndrome: a volumetric imaging study.

Rett syndrome is a pediatric neurological disorder of unknown etiology defined by the presence of severe neurodevelopment decline, acquired microcephaly, dementia, abnormalities of movement, autistic behavior, and seizures in young female children. In this study, the neuroanatomy of 11 females with Rett syndrome and 15 age- and gender-matched control subjects was investigated in vivo with quantitative neuroimaging techniques. Compared to control subjects, the patients with Rett syndrome were found to have significantly reduced cerebral volume; evidence of greater loss of gray matter in comparison to white matter; regional variation in cortical gray matter, with the frontal regions showing the largest decrease; and reduced volume of the caudate nucleus and midbrain, even when taking into account general reduction in the size of the brain. In addition, there was no evidence of an ongoing degenerative process in this sample of girls with Rett syndrome. The consistency of these data with results from neuropathological investigations points to the need for continued quantitative neuroimaging studies of children with this condition. In particular, research employing serial longitudinal scans of very young children manifesting early signs of the clinical syndrome holds promise for helping to elucidate the neuropathological pathways leading to the debilitating clinical manifestations of Rett syndrome.

Adolescent↗

PubMed1993

Developmental changes in human gamma-aminobutyric acidA receptor subunit composition.

gamma-Aminobutyric acid (GABA) is the neurotransmitter at most inhibitory synapses in the human central nervous system. The GABAA receptor, a ligand-gated ion channel, is the site of action of benzodiazepines, the most widely prescribed neuroactive drugs. It was recently demonstrated that there are multiple subtypes of GABAA receptors. Studies of rodents have shown that receptor subunits are developmentally controlled. The major alpha subunit of the adult receptor is expressed at low levels before birth. This study, using postmortem human tissue, shows that GABAA receptors are present in significant numbers in the human cerebellum at birth, and the numbers rise threefold by adulthood. Two subtypes of benzodiazepine receptors were detected by binding studies in the neonate, whereas only a single subtype of receptor was detected in the adult cerebellum. Comparison to recombinant human GABAA receptors shows that receptors containing alpha 1 constitute 50% of the receptors at birth and the percentage rises to over 95% by adulthood. In both cerebral cortex and cerebellum, a dramatic rise in alpha 1 messenger RNA was observed during development, suggesting that the complement of GABAA receptors differs in infants and adults. These findings have significant implications for normal neurodevelopment as well as for the understanding and treatment of pathophysiological states such as seizures.

Adolescent↗

PubMed1995

Early copper therapy in classic Menkes disease patients with a novel splicing mutation.

To correlate genotype with response to early copper histidine therapy in Menkes disease, an X-linked disorder of copper transport, we performed mutational analysis in 2 related males who began treatment at the age of 10 days and prenatally at 32 weeks' gestation, respectively. A G to T transversion at the -1 exonic position of a splice donor site was identified, predicting a glutamine to histidine substitution at codon 724 of the Menkes copper-transporting ATPase gene. The Q724H mutation disrupts proper splicing and generates five mutant transcripts that skip from one to four exons. None of these transcripts is predicted to encode a functional copper transport protein. Copper histidine treatment normalized circulating copper and ceruloplasmin levels but did not improve the baseline deficiency of dopamine-beta-hydroxylase, a copper-dependent enzyme. At the age of 36 months, the first patient was living and had neurodevelopmental abilities ranging from 10 to 15 months. The second patient also showed delayed neurodevelopment and died of pulmonary complications at the age of 5 1/2 months. We conclude that early copper histidine therapy does not normalize neurological outcome in patients with the Q724H splicing mutation, and suggest that preservation of some residual Menkes ATPase activity may be a general prerequisite for significant clinical efficacy from such treatment.

Adenosine Triphosphatases↗

PubMed2005

Neuronal migration is transiently delayed by prenatal exposure to intermittent hypoxia.

BACKGROUND: Neonatal neurodevelopment is influenced by a variety of external factors, although the mechanisms responsible are poorly understood. Prenatal hypoxia, from physiological or chemical sources, can have no discernible effect, or can result in a broad spectrum of abnormalities. METHODS: To mimic some of the maternal effects of smoking, we developed a model that investigates the effects of intermittent hypoxia (IH), with or without concurrent nicotine in timed pregnant Sprague-Dawley rats. RESULTS: We found no significant differences between litter sizes or birthweight of pups from any treatment group, but animals exposed to IH (with or without nicotine) showed long term diminished body weights. Animals subjected to IH consistently showed a transient delay in neuronal migration early in the postpartum period, which was amplified by concurrent nicotine administration. We observed increased c-Abl protein levels in animals from the IH treatment groups. Multiple proteins involved in the intricate control of neuronal migration were also altered in response to this treatment, primarily the downstream targets of c-Abl: Cdk5, p25, and the cytoskeletal elements neurofilament H and F-actin and catalase. Catalase activity and protein levels, already elevated in response to IH, were further amplified by simultaneous nicotine exposure. CONCLUSIONS: This new model provides a novel system for investigating the effects of low grade IH in the developing brain and suggests that concurrent nicotine further aggravates many of the deleterious effects of IH.

Actins↗