Impaired spatial working memory and altered choline acetyltransferase (CHAT) immunoreactivity and nicotinic receptor binding in rats exposed to intermittent hypoxia during sleep.

Exposure to intermittent hypoxia (IH), such as occurs in sleep-disordered breathing (SDB), is associated with cognitive impairment, neurodegeneration, oxidative stress, and inflammatory responses within rodent brain regions such as the basal forebrain. In this region, damage to cholinergic neurons correlates with working memory deficits in a number of neurodegenerative disorders, suggesting that degeneration of cholinergic systems may also contribute to the working memory impairments observed after IH exposures. We therefore examined basal forebrain choline acetyltransferase (CHAT) immunohistochemistry, nicotinic receptor binding in the prefrontal cortex (PFC), and working memory, in male rats tested on a delayed matching to place (DMP) task in the water maze following exposure to either room air (RA) or intermittent hypoxia (IH; alternating 90s epochs of 21% and 10% O(2) during sleep).

Functional imaging reveals respiratory network activity during hypoxic and opioid challenge in the neonate rat tilted sagittal slab preparation.

In mammals, respiration-modulated networks are distributed rostrocaudally in the ventrolateral quadrant of the medulla. Recent studies have established that in neonate rodents, two spatially separate networks along this column-the parafacial respiratory group (pFRG) and the pre-Bötzinger complex (preBötC)-are hypothesized to be sufficient for respiratory rhythm generation, but little is known about the connectivity within or between these networks. To be able to observe how these networks interact, we have developed a neonate rat medullary tilted sagittal slab, which exposes one column of respiration-modulated neurons on its surface, permitting functional imaging with cellular resolution.

Hypoxemia and obesity modulate plasma C-reactive protein and interleukin-6 levels in sleep-disordered breathing.

C-reactive protein (CRP) and interleukin-6 (IL-6) are pro-inflammatory proteins and important risk factors for atherosclerosis. Plasma CRP levels in snoring children may or may not be elevated. Since obesity is prevalent among snoring children and is associated with elevated CRP levels, we aimed to investigate the relative contributions of sleep-disordered breathing (SDB) and obesity to the inflammatory processes in snoring children in this prospective study.

Persistence of obstructive sleep apnea syndrome in children after adenotonsillectomy.

Objective: To investigate the relative contribution of various risk factors to the surgical outcome of adenotonsillectomy for obstructive sleep apnea syndrome in children.

Study Design: Children (n = 110; mean age, 6.4 +/- 3.

Obesity and obstructive sleep apnea in children.

The prevalence and severity of obesity in children and adolescent is dramatically increasing worldwide with a corresponding increase in the prevalence of obesity-associated morbidities particularly those involving OSAS and metabolic and cardiovascular sequelae. Obstructive sleep apnea and obesity hypoventilation syndrome are important and serious consequences of obesity, and may in fact mediate components of the association between obesity and metabolic and cardiovascular morbidities, most likely via potentiation of inflammatory cascades. It is anticipated that the increased prevalence of obesity in children and adolescents in our society will be accompanied by a steady increase in the incidence of OSAS.

Respiratory and metabolic responses to early postnatal chronic intermittent hypoxia and sustained hypoxia in the developing rat.

Exposure to sustained hypoxia (SH) differentially modifies the hypoxic ventilatory response (HVR) in adults and developing rats. We examined the possibility that postnatal intermittent hypoxia (IH), a more prevalent clinical condition than SH, may lead to significant modifications of ventilatory patterning during development. Sprague-Dawley rat pups were exposed as of the d 1 of life to either SH (10% O2) or IH [alternating room air (RA) and 10% O2 every 90 s] for up to 30 d; controls were exposed to normoxia.

Inflammatory mediators in exhaled breath condensate of children with obstructive sleep apnea syndrome.

Background: Upper airway inflammation is now recognized in adults with obstructive sleep apnea (OSA) syndrome. However, the role played by eicosanoids such as leukotrienes and prostaglandins is unclear.

Objective: To investigate whether eicosanoids are measurable in exhaled breath condensate (EBC), and to determine whether differences in these inflammatory mediators emerge among children with and without sleep-disordered breathing (SDB).

Obesity increases the risk for persisting obstructive sleep apnea after treatment in children.

Objective: To evaluate the impact of obesity at diagnosis on treatment outcomes in paediatric obstructive sleep apnea (OSA).

Methods: Children were included if they had both diagnostic and follow-up studies for OSA. Anthropological and polysomnographic data were collected at the time of both studies.

Maxillary sinus augmentation.

Attention to the principles of bone grafting, bone healing, and maxillary sinus physiology as well as anatomy is critical to the successful placement of dental implants in the posterior maxilla. The integration of these principles must take into account the restorative dental requirements and the patient's autonomy in guiding implant reconstruction. As in so many clinical disciplines, additional research is needed to provide better guidance for clinicians.

Comparison of a new forehead reflectance pulse oximeter sensor with a conventional digit sensor in pediatric patients.

Background: During conditions of poor perfusion, the accuracy of conventional extremity-based pulse oximeters may be limited. Limited evidence suggests that forehead perfusion may be better preserved during such periods, but pediatric experience with newer forehead reflectance sensors is limited. We prospectively compared the accuracy of a forehead reflectance sensor, the Max-Fast, with a new-generation digit sensor in pediatric patients.

Sleep apnea in children--treatment considerations.

The prevalence of obstructive sleep apnea (OSA) is clearly increasing in the pediatric population. However, the polysomnographic criteria for treatment still remain to be defined by appropriate scientific methodology. Furthermore, the overall efficacy of currently available interventions such as surgical removal of enlarged tonsils and adenoids (T&A) is unknown, such that we are currently unable to precisely define who the high risk patients are, and the cost and benefits associated with any given treatment.

The status of diagnostic testing following referral from universal newborn hearing screening.

The Joint Committee on Infant Hearing 2000 position statement includes guidelines for the development of Early Hearing Detection and Intervention programs. These guidelines provide specific recommendations for the audiologic test battery for infants who fail a newborn infant hearing screening. The recommended test battery includes electrophysiologic measures such as the ABR, frequency specific electrophysiologic tests, bone-conducted ABR, OAEs, tympanometry using high frequency probe stimuli, and acoustic reflexes.

Hypoxia differentially regulates the expression of neuroglobin and cytoglobin in rat brain.

Neuroglobin (Ngb) and Cytoglobin (Cygb) are new members of the globin family and display heterotopic expression patterns. To examine the effect of different hypoxia profiles on expression of Ngb and Cygb in rodent brain, rats were exposed to either sustained hypoxia (SH; 10% O(2)) or intermittent hypoxia (IH; 10% and 21% O(2) alternating every 90 s) for 1, 3, 7 and 14 days, and mRNA and protein expression of Ngb and Cygb were assessed in brain cortex. SH increased Ngb mRNA and protein expression throughout the exposure, while IH only elicited slight increases in Ngb expression at day 1.

Heliox-driven albuterol nebulization for asthma exacerbations: an overview.

Our understanding of albuterol nebulization driven by helium-oxygen mixture (heliox) has matured with recent advances in clinical therapy, delivery systems, and understanding of dosing; this has led to substantial improvements in delivery as well as refinements of research protocols for asthma exacerbations. This review begins with heliox inhalation therapy and then addresses heliox as a driving gas for nebulization. Technical considerations are reviewed, including optimal gas mixtures, flow-rate adjustment factors, and nebulizer setup.

Intersex genetic anomalies with malignant potential.

Purpose Of Review: Mutations in genes contributing to sexual determination and differentiation can cause clinical syndromes with potential for the development of malignant tumors. This article focuses on intersex disorders requiring surveillance for and/or operation to prevent or treat malignancies.

Recent Findings: Classification of intersex disorders into risk groups gives guidance to physicians about children who are vulnerable to malignant degeneration of the gonads or kidneys.

Follow-up on metabolic markers in children treated for obstructive sleep apnea.

Rationale: In adults, obstructive sleep apnea (OSA) is associated with metabolic dysfunction that improves with treatment of OSA. No equivalent studies exist in children.

Objective: To examine the relationship between metabolic markers and OSA with time and treatment in children.

Anatomical changes in selected cardio-respiratory brainstem nuclei following early post-natal chronic intermittent hypoxia.

Early post-natal environmental exposures, including chronic intermittent hypoxia (CIH), may lead to long-term alterations in cardio-respiratory control, such as reductions in baroreflex sensitivity and acute hypoxic ventilatory responses in adult rats. Although the mechanisms underlying CIH-induced functional metaplasticity are unclear, anatomical alterations within selected brainstem nuclei may develop after CIH. To examine this issue, male rats were exposed to CIH (RAIH) or room air (RARA) for the first 30 days of life and were microinjected unilaterally in the right nodose ganglion with the neuronal tracer tetramethylrhodamine-dextran (TMR-D) to label brainstem neurons receiving vagal and glossopharyngeal projections.

High fat/refined carbohydrate diet enhances the susceptibility to spatial learning deficits in rats exposed to intermittent hypoxia.

Background: Intermittent hypoxia during sleep (IH), as occurs in sleep disordered breathing (SDB), induces spatial learning deficits associated with regulation of transcription factors associated with learning and memory in the hippocampal CA1 region in rats. high fat refined carbohydrate diet (HF/RC) can induce similar deficits and associated changes in signaling pathways under normoxic conditions.

Methods: Sprague-Dawley adult male rats were fed either with (HF/RC) or low fat/complex carbohydrate diet (LF/CC) starting at post-natal day 30 for 90 days, and were then exposed for 14 days during light phase (12 h/day) to either normoxia (RA) or IH (21% and 10% O2 alternations every 90 s).

Regulation of PDK mRNA by high fatty acid and glucose in pancreatic islets.

Pyruvate dehydrogenase (PDH) converts pyruvate to acetyl-CoA, links glycolysis to the Krebs cycle, and plays an important role in glucose metabolism and insulin secretion in pancreatic beta cells. In beta cells from obese and Type 2 diabetic animals, PDH activity is significantly reduced. PDH is negatively regulated by multiple pyruvate dehydrogenase kinase (PDK) isotypes (PDK subtypes 1-4).

Plasma adhesion molecules in children with sleep-disordered breathing.

Study Objectives: To determine whether childhood sleep-disordered breathing (SDB) is associated with elevated levels of plasma adhesion molecules.

Design: Prospective, observational study.

Setting: Sleep Medicine Center of Kosair Children's Hospital.

Differential metabolic adaptation to acute and long-term hypoxia in rat primary cortical astrocytes.

Brain astrocytes provide structural and metabolic support to surrounding cells during ischemia. Glucose and oxygen are critical to brain function, and glucose uptake and metabolism by astrocytes are essential to their metabolic coupling to neurons. To examine astrocyte metabolic response to hypoxia, cell survival and metabolic parameters were assessed in rat primary cortical astrocytes cultured for 3 weeks in either normoxia or in either 1 day or 3 weeks sustained hypoxia (5% O2).

Urinary protein expression patterns in children with sleep-disordered breathing: preliminary findings.

Background: Obstructive sleep apnea (OSA) is the most common form of sleep-disordered breathing, with almost 15 million Americans affected and many more at risk. Current diagnostic approach to OSA requires polysomnography, which is laborious, onerous, and time-consuming. There is ample evidence that inflammatory responses to the perturbations associated with OSA trigger a variety of genes and signaling cascades that ultimately lead to end-organ injury and changes in kidney function and protein expression.

Reciprocal interactions between spontaneous and respiratory arousals in adults with suspected sleep-disordered breathing.

Background And Purpose: Excessive daytime sleepiness (EDS) is a major consequence of sleep-disordered breathing (SDB) in adults. In snoring children, spontaneous and respiratory arousals display reciprocal interactions, allowing for development of a new quantitative measure, the sleep pressure score (SPS), which provides intra-polysomnographic estimates of sleep pressure/disruption. The aim of the present study was to assess the interactions between respiratory and spontaneous arousals in adults with suspected SDB, and to examine whether the SPS and the Epworth sleepiness scale (ESS) are correlated.

Oxidant stress and inflammation in the snoring child: confluent pathways to upper airway pathogenesis and end-organ morbidity.

Snoring in children is increasingly being recognized as a highly prevalent condition, and indicates the presence of heightened upper airway resistance during sleep. In this paper, we present evidence to support the hypothesis that local inflammatory processes within the upper airway contribute to the pathophysiology of adenotonsillar hypertrophy and altered reflexes potentially leading to increased propensity for upper airway obstruction during sleep. Furthermore, the cumulative evidence supporting multiorgan morbidity for sleep-disordered breathing (SDB) is reviewed, and a unified hypothesis of a triple risk model proposing oxidative-inflammatory mechanisms as mediating the morbid consequences of SDB is presented.