Impaired control of renal sympathetic nerve activity following neonatal intermittent hypoxia in rats.

Apneas and recurring oxygen desaturations can occur in preterm infants and young children. To investigate long-term effects of neonatal intermittent hypoxia on baroreflex control of sympathetic nerve activity, we studied 5-7-month-old (adult) Sprague-Dawley rats exposed to chronic intermittent hypoxia (CIH, n=9; 8% O2 for 90 s alternating with 90 s 21% O2, 12h/day) for their first 30 postnatal days or controls exposed to normoxia (C, n=9). In adult CIH and C rats, baseline heart rate, mean arterial pressure, and plasma concentration of epinephrine and norepinephrine were similar.

Correlates of sleep and pediatric bipolar disorder.

Study Objective: To determine, based on a large community sample, the prevalence and associated sleep characteristics of children with a bipolar mood disturbance behavioral profile.

Methods: Participants who fit the pediatric bipolar disorder profile as derived from the Child Behavior Checklist were matched to control participants for age, sex, ethnicity, parentally reported attention-deficit/hyperactivity disorder, psychotropic medication usage, and apnea-hypopnea indexes. Paired comparisons were made between the groups to examine differences on polysomnographic data and parentally reported sleep characteristics.

Autonomic dysfunction in children with sleep-disordered breathing.

Study Objectives: To measure sympathetic responses in children with and without sleep-disordered breathing.

Design: Prospective, observational study.

Setting: Kosair Children's Hospital Sleep Medicine and Apnea Center.

Early postnatal chronic intermittent hypoxia modifies hypoxic respiratory responses and long-term phrenic facilitation in adult rats.

Acute isocapnic intermittent hypoxia elicits time-dependent, serotonin-dependent enhancement of phrenic motor output in anesthetized rats (phrenic long-term facilitation, pLTF). In adult rats, pLTF is enhanced by chronic intermittent hypoxia (CIH). To test the hypothesis that early postnatal CIH induces persistent modifications of ventilation and pLTF, we exposed male Sprague-Dawley rat pups on their first day of life to a CIH profile consisting of alternating room air and 10% oxygen every 90 s for 30 days during daylight hours (RAIH) or to comparable exposures consisting of room air throughout (RARA).

Intranasal steroids and oral leukotriene modifier therapy in residual sleep-disordered breathing after tonsillectomy and adenoidectomy in children.

Objective: Tonsillectomy and adenoidectomy (T&A) is the primary therapeutic approach for sleep-disordered breathing (SDB) in children. However, residual mild SDB will be found in more than one third of these patients after T&A. We hypothesized that combined therapy with the leukotriene receptor antagonist montelukast and intranasal budesonide would result in normalization of residual SDB after T&A.

Apolipoprotein E-deficient mice exhibit increased vulnerability to intermittent hypoxia-induced spatial learning deficits.

Exposure to intermittent hypoxia, such as occurs in sleep-disordered breathing, is associated with oxidative stress, cognitive impairments, and increased neuronal apoptosis in brain regions involved in learning and memory. Apolipoprotein E (ApoE) has been implicated in neurodegenerative disorders, and in vitro studies suggest that one of the functions of ApoE may be to confer protection from oxidant stress-induced neuronal cell loss. Therefore, we hypothesized that ApoE-deficient (ApoE-/-) mice would display increased cognitive impairments following intermittent hypoxia.

Tea tree oil.

Tea tree oil is a popular ingredient in many over-the-counter healthcare and cosmetic products. With the explosion of the natural and alternative medicine industry, more and more people are using products containing tea tree oil. This article reviews basic information about tea tree oil and contact allergy, including sources of tea tree oil, chemical composition, potential cross reactions, reported cases of allergic contact dermatitis, allergenic compounds in tea tree oil, practical patch testing information, and preventive measures.

Autonomic function in children with congenital central hypoventilation syndrome and their families.

Study Objectives: Congenital central hypoventilation syndrome (CCHS) is a genetic disorder characterized by failure of automatic control of breathing in the absence of obvious anatomic lesions. There have been several reports suggesting that CCHS patients display autonomic dysregulation. Pulse arterial tonometry (PAT) is a novel technique that provides noninvasive moment-to-moment measurements of sympathetic tone changes to the cutaneous vascular bed.

Developmental plasticity of respiratory control following intermittent hypoxia.

During development, windows of increased vulnerability to noxious stimulus occur. These critical periods of maturation represent times at which the maturing animal is uniquely susceptible to external perturbations that may alter the ultimate configuration of neural networks and their associated function(s), thereby inducing persistent (mal)adaptive changes. In contrast, when comparable perturbations are applied to adult animals the associated adaptive changes do not typically persist.

Postnatal intermittent hypoxia alters baroreflex function in adult rats.

Chronic perinatal intermittent hypoxia (IH) could have long-term cardiovascular effects by altering baroreflex function. To examine this hypothesis, we exposed rats (n = 6/group) for postnatal days 1-30 or prenatal embryonic days 5-21 to IH (8% ambient O2 for 90 s after 90 s of 21% of O2, 12 h/day) or to normoxia (control). Baroreflex sensitivity (BRS) and cardiac chronotropic responses were examined in anesthetized animals 3.

Intermittent hypoxia during development induces long-term alterations in spatial working memory, monoamines, and dendritic branching in rat frontal cortex.

Exposure to intermittent hypoxia (IH), such as occurs in sleep-disordered breathing, is associated with increased apoptosis in vulnerable brain regions as well as with spatial reference memory deficits in adult and developing rats. The latter are more susceptible to IH, suggesting that early exposure to IH may have long-term consequences. Rats were exposed to 14 d of room air (RA) or IH starting at postnatal d 10.

Effects of endotoxin administration and cerebral hypoxia-ischemia on complement activity and local transcriptional regulation in neonatal rats.

It is not known whether up-regulation of complement components, either circulating or locally synthesized, contributes to an increased susceptibility to neonatal hypoxic-ischemic (HI) cerebral injury. Therefore, we tested the hypothesis that in neonatal rats subjected to a unilateral HI cerebral insult, prior administration of E. coli lipopolysaccharide (LPS) augments (1) complement-mediated serum hemolytic activity, and (2) C3 mRNA and C9 mRNA levels in hepatic and cerebral tissue.

Long-term effect of maternal obesity on pancreatic beta cells of offspring: reduced beta cell adaptation to high glucose and high-fat diet challenges in adult female mouse offspring.

Aim/hypothesis: Obesity is a global problem with high risks of cardiovascular diseases, stroke and type 2 diabetes. It is well known that maternal obesity affects offspring by inducing malformation, functional abnormalities in many organs and cells, and by increased risk of obesity and type 2 diabetes. However, little is known about abnormalities induced by maternal obesity in pancreatic beta cells of offspring.

Lymphangiomatosis: a case report.

Lymphangiomatosis is a rare congenital malformation that can involve visceral organs, soft tissue, and bone. This report describes a 5-year-old female with this disorder who presented with respiratory distress and subsequently died. Clinical, diagnostic, and treatment aspects of this entity are discussed.

Obesity rather than severity of sleep-disordered breathing as the major determinant of insulin resistance and altered lipidemia in snoring children.

Objective: Sleep-disordered breathing (SDB) is associated with insulin resistance and dyslipidemia in adults and in obese children. However, the prevalence of such metabolic abnormalities among snoring children is unknown. This study was done to prospectively assess the relative contribution of SDB and obesity to metabolic disturbances in a large cohort of snoring children.

Prospective evaluation of dexmedetomidine for noninvasive procedural sedation in children.

Objective: Children often require sedation for lengthy noninvasive procedures. Conventional agents such as chloral hydrate, benzodiazepines, or barbiturates have been associated with sedation failure, respiratory depression, and paradoxic agitation. Dexmedetomidine is a newer alpha(2)-adrenergic receptor agonist with sedative properties and minimal respiratory depression.

Cultural influences on the bedtime behaviors of young children.

Background And Purpose: This study was designed to assess potential relationships of race and socioeconomic status (SES) to bedtime behavior from a community sample of 2- to 7-year-old children.

Patients And Methods: A previously validated sleep questionnaire was administered to parents of children enrolled in the Jefferson County, Kentucky school system. The sleep behavior of African-American (n=973) and Caucasian (n=2398) children was analyzed.

Seven-year clinical experience with the extracardiac pedicled pericardial Fontan operation.

Background: Although improved perioperative outcomes with growth potential of the extracardiac pedicled pericardial Fontan (EPPF) operation have been suggested, no advantage has been demonstrated.

Methods: We retrospectively reviewed our institutional experience of 54 consecutive patients undergoing EPPF between June 1996 and August 2003. Clinical and echocardiographic follow-up was obtained yearly with a mean follow-up of 2.

Transcatheter ablation of supraventricular tachycardia and closure of a large secundum ASD in a Jehovah's Witness.

This report describes successful radiofrequency ablation of typical atrioventricular (AV) node reentrant tachycardiafollowed by transcatheter closure of a large secundum atrial septal defect in a patient of the Jehovah's Witness faith. Both procedures were performed successfully during the same catheterization, without complication or need for blood transfusion.

Changes in ventilatory adaptations associated with long-term intermittent hypoxia across the age spectrum in the rat.

Intermittent hypoxia (IH) induces alterations in respiratory control that reflect various types of ventilatory plasticity. In freely behaving rats, acute exposure to IH elicits enhancements in normoxic minute ventilation (VE), termed ventilatory long-term facilitation. Exposure to longer time periods of IH induces unique ventilatory adaptations to intermittent hypoxia (VAIH).

Calcium/calmodulin-dependent kinase II mediates critical components of the hypoxic ventilatory response within the nucleus of the solitary tract in adult rats.

Calcium/calmodulin-dependent kinase II (CaMKII) is an ubiquitous second messenger that is highly expressed in neurons, where it has been implicated in some of the pathways regulating neuronal discharge as well as N-methyl-d-aspartate receptor-mediated synaptic plasticity. The full expression of the mammalian hypoxic ventilatory response (HVR) requires intact central relays within the nucleus of the solitary tract (NTS), and neural transmission of hypoxic afferent input is mediated by glutamatergic receptor activity, primarily through N-methyl-D-aspartate receptors. To examine the functional role of CaMKII in HVR, KN-93, a highly selective antagonist of CaMKII, was microinjected in the NTS via bilaterally placed osmotic pumps in freely behaving adult male Sprague-Dawley rats for 3 days.

Leukotriene modifier therapy for mild sleep-disordered breathing in children.

Background: Children with mild sleep-disordered breathing (SDB), who may not be recommended for adenotonsillectomy, frequently exhibit neurocognitive and behavioral morbidity, and may benefit from alternative therapeutic interventions, such as leukotriene modifier therapy.

Methods: Twenty-four children with SDB completed an open-label intervention study for 16 weeks with daily montelukast therapy. Sleep studies and adenoid size estimates from lateral X-ray films of the neck were obtained before and after treatment.

The administration of cobra venom factor reduces post-ischemic cerebral injury in adult and neonatal rats.

The role of complement in post-ischemic cerebral injury is incompletely understood. Therefore, experiments were designed to test the effect of complement depletion on cerebral infarct volume in adult rats and cerebral atrophy in neonatal rats. Cerebral infarcts were induced in adult rats by transient filamentous occlusion of the right middle cerebral artery (MCAO).

Tyrosine hydroxylase expression and activity in the rat brain: differential regulation after long-term intermittent or sustained hypoxia.

Tyrosine hydroxylase, a hypoxia-regulated gene, may be involved in tissue adaptation to hypoxia. Intermittent hypoxia, a characteristic feature of sleep apnea, leads to significant memory deficits, as well as to cortex and hippocampal apoptosis that are absent after sustained hypoxia. To examine the hypothesis that sustained and intermittent hypoxia induce different catecholaminergic responses, changes in tyrosine hydroxylase mRNA, protein expression, and activity were compared in various brain regions of male rats exposed for 6 h, 1 day, 3 days, and 7 days to sustained hypoxia (10% O(2)), intermittent hypoxia (alternating room air and 10% O(2)), or normoxia.

Sleep in children with attention deficit/hyperactivity disorder.

Attention-deficit hyperactivity disorder (ADHD) is one of the most common psychological disorders in children. Sleep disturbances are also very prevalent among the pediatric age range and can lead to substantial behavioral and cognitive consequences that may mimic ADHD. Conversely, children with ADHD may suffer from significant sleep disturbances that may originate in the biochemical disturbances that underlie their deficits in executive function and attention.