Publications by authors named "Thornton Mason"

Water striders are abundant in areas with high humidity and rainfall. Raindrops can weigh more than 40 times the adult water strider and some pelagic species spend their entire lives at sea, never contacting ground. Until now, researchers have not systematically investigated the survival of water striders when impacted by raindrops.

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Introduction: Stevens-Johnson syndrome/toxic epidermal necrolysis (SJS/TEN) is a rare and dangerous dermatologic emergency. It can have different presentations, especially in patients with multiple drug causes, and definitive management of SJS/TEN in these presentations remains unclear. Systemic corticosteroids, TNF inhibitors, and cyclosporine A are promising therapies.

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This study was aimed to evaluate the yearly incidence of pediatric narcolepsy prior to and following the 2009 H1N1 pandemic and to evaluate seasonal patterns of narcolepsy onset and associations with H1N1 influenza infection in the United States. This was a multicenter retrospective study with prospective follow-up. Participants were recruited from members of the Pediatric Working Group of the Sleep Research Network including 22 sites across the United States.

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Future terrestrial and interplanetary travel will require high-speed flight and reentry in planetary atmospheres by way of robust, controllable means. This, in large part, hinges on having reliable propulsion systems for hypersonic and supersonic flight. Given the availability of fuels as propellants, we likely will rely on some form of chemical or nuclear propulsion, which means using various forms of exothermic reactions and therefore combustion waves.

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Objective: To determine pre- and postoperative prevalence of obstructive sleep apnea (OSA) in patients with 22q11.2 deletion syndrome (DS) undergoing wide posterior pharyngeal flap (PPF) surgery for velopharyngeal dysfunction (VPD).

Design: Retrospective study using pre- and postoperative polysomnography (PSG) to determine prevalence of OSA.

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Kleine-Levin syndrome (KLS) is a rare disorder characterized by discrete episodes of hypersomnia associated with cognitive and behavioural abnormalities, as well as normal alertness and function between episodes. The prevalence of KLS may be underestimated as it is often misdiagnosed and managed as another sleep disorder, neurological disorder or psychiatric condition. KLS is more typically seen in adolescence than at other ages, and is more common in males than in females.

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Objective: The aim of this study is to understand the impact of a 5-day period of nap restriction on sleep patterns and cognitive function in typically developing preschoolers, aged 3 to 4 years.

Method: Following 1 week of baseline assessment, 28 children were randomly assigned to either a "napping as usual" group ( n = 15) or a 5-day period of nap restriction ( n = 13). Sleep was assessed with sleep logs and actigraphy; cognition was assessed at baseline and at the end of the intervention week.

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Study Objectives: Although the American Academy of Sleep Medicine (AASM) mandates that periodic limb movements during sleep (PLMS) be scored on every polysomnogram, and considers a periodic limb movement index (PLMI) > 5/h abnormal in children, there is a lack of community-derived data regarding the prevalence of PLMS in children, and no data to support this cutoff value. Therefore, the aim of this study was to determine the prevalence of PLMS in a sample of normal children.

Design: Retrospective study.

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Unlabelled: Otolaryngologic problems are common in the 22q11.2 deletion syndrome (DS) population. Structural anomalies and retrognathia may predispose these patients to obstructive sleep apnea (OSA).

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Sickle cell disease (SCD) is a disorder known to impact the respiratory system. We sought to identify respiratory muscle force and lung volume relationships in a paediatric SCD population. Thirty-four SCD-SS subjects underwent pulmonary function testing.

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Background: Sleepwalking is typically a benign and self-limited non-rapid eye movement parasomnia of childhood.

Patient: We describe an unusual 15-year-old boy referred to our sleep center for new-onset sleepwalking.

Results: An overnight polysomnogram was normal from a respiratory standpoint, but a concurrent extended electroencephalogram montage showed frequent epileptiform discharges from the right parietal-temporal region and two electroclinical seizures arising from the right-frontal-central-temporal region during sleep.

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We describe 19 unrelated individuals with submicroscopic deletions involving 10p15.3 characterized by chromosomal microarray (CMA). Interestingly, to our knowledge, only two individuals with isolated, submicroscopic 10p15.

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Objectives: To test agreement and define differences in periodic limb movements in sleep (PLMS) measured by polysomnography and an ankle activity monitor, and to describe PLMS variability across nights, feasibility of home monitoring, and correlates of PLMS in children with sickle cell disease (SCD).

Methods: Twenty children with SCD and restless legs syndrome (RLS) symptoms or polysomnography-documented PLMS underwent concurrent attended polysomnography and ankle activity monitoring over one to two nights and home activity monitoring for three nights. Serum iron and ferritin were measured pre- and post-polysomnography.

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Assessment of oxyhemoglobin saturation in patients with sickle cell disease (SCD) is vital for prompt recognition of hypoxemia. The accuracy of pulse oximeter measurements of blood oxygenation in SCD patients is variable, partially due to carboxyhemoglobin (COHb) and methemoglobin (MetHb), which decrease the oxygen content of blood. This study evaluated the accuracy and reliability of a non-invasive pulse co-oximeter in measuring COHb and MetHb percentages (SpCO and SpMet) in children with SCD.

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Background: The prevalence of obstructive sleep apnea syndrome (OSAS) is higher in children with sickle cell disease (SCD) as compared with the general pediatric population. It has been speculated that overgrowth of the adenoid and tonsils is an important contributor.

Methods: The current study used MRI to evaluate such an association.

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Objective: To analyze sleep in children with Williams Syndrome (WS) compared to normal healthy controls in order to determine whether particular sleep features are characteristic of WS, and to explore associations between disturbed sleep and behavior.

Methods: Thirty-five children with genetically-confirmed WS and 35 matched controls underwent overnight polysomnography and performance testing in the Sleep Center at the Children's Hospital of Philadelphia. Parents completed questionnaires regarding the subjects' sleep and behavior.

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Study Objectives: To describe the rate, distribution and correlates of periodic limb movements in sleep (PLMS) in children with sickle cell disease (SCD).

Design: Prospective, cross-sectional.

Setting: Hospital-based sleep laboratory.

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Actigraphy provides a non-invasive objective means to assess sleep-wake cycles. In young children, parent logs can also be useful for obtaining sleep-wake information. The authors hypothesized that actigraphy and parent logs were both equally valid instruments in healthy preschool-aged children.

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Study Objectives: The prevalence of obstructive sleep apnea syndrome (OSAS) in sickle cell disease (SCD) has been reported to be higher than that in the general pediatric population. However, not all subjects with SCD develop OSAS. We hypothesized that SCD patients with OSAS have a blunted neuromuscular response to subatmospheric pressure loads during sleep, making them more likely to develop upper airway collapse.

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Study Objectives: The gold-standard test used to diagnose childhood obstructive sleep apnea is polysomnography. However, this test requires an overnight stay at a sleep laboratory and the attachment of multiple sensors to the patient. The long-term impact of this testing on the child and family are not known.

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Objective: To determine the relationship between napping and cognitive function in preschool-aged children.

Methods: Daytime napping, nighttime sleep, and cognitive function were assessed in 59 typically developing children aged 3 to 5 years, who were enrolled in full-time childcare. Participants wore an actigraphy watch for 7 days to measure sleep and napping patterns and completed neuropsychological testing emphasizing attention, response control, and vocabulary.

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Obesity continues to be a major public health issue. In adolescents, there are limited studies on the relationship between obesity and sleep duration. We found hypothesized that an average sleep duration of <6 h in adolescents was associated with obesity.

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Objective: Adolescents may not receive the sleep they need. New media technology and new, popular energy drinks may be implicated in sleep deficits. In this pilot study we quantified nighttime technology use and caffeine consumption to determine effects on sleep duration and daytime behaviors in adolescents.

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Rapid eye movement sleep distribution changes during development, but little is known about rapid eye movement latency variation in childhood by age, sex, or pathologic sleep states. We hypothesized that: (1) rapid eye movement latency would differ in normal children by age, with a younger cohort (1-10 years) demonstrating shorter rapid eye movement latency than an older group (>10-18 years); (2) rapid eye movement latency in children would differ from typical adult rapid eye movement latency; and (3) intrinsic sleep disorders (narcolepsy, pediatric obstructive sleep apnea syndrome) would disrupt normal developmental patterns of rapid eye movement latency. A retrospective chart review included data from clinic visits and of rapid eye movement latency and other parameters measured by overnight polysomnography.

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