Dissolution of concentrated surfactant solutions: from microscopy imaging to rheological measurements through numerical simulations.

Concentrated aqueous solutions of surfactants, often referred to as pastes, experience complex phase and rheology changes upon dissolution in water, which is a typical step in the production of liquid detergents. During the dilution process, depending on water content, surfactant molecules can arrange in different morphologies, such as lamellar or cubic and hexagonal structures. These phases are characterized by different physico-chemical properties, such as viscosity or diffusivity, which lead to non-simple transport mechanisms during the dissolution process. In this work, we investigate the dissolution of concentrated Sodium Lauryl Ether Sulfate (SLES) pastes in water under quiescent conditions by coupling different experimental techniques. A thorough rheological characterization of the system showed non-monotonic changes of several orders of magnitude in its viscosity and viscoelastic moduli as a function of water content. Time-lapse microscopy allowed us to image the dynamic evolution of the phase changes as water penetrated in a disk-shaped sample (with the same geometry used in rheological tests). Numerical simulation, based on a simple diffusion-based multi-parameter model is shown to describe satisfactorily SLES dissolution data.

Adenotonsillectomy and orthodontic therapy in pediatric obstructive sleep apnea.

PURPOSE: Rapid maxillary expansion (RME) is an additional treatment in pediatric obstructive sleep apnea (OSA). The aim of this study was to present data about the outcome of adenotonsillectomy (AT) and of RME in a clinical sample of pediatric OSA. METHODS: We consecutively enrolled children with OSA to undergo RME or AT. The age and the severity of OSA are the main factors involved in the choice of treatment. A polysomnography was performed at the baseline (i.e., before treatment, T0) and 1 year after treatment (T1). RESULTS: A total of 52 subjects fulfilled the inclusion criteria. Twenty-five children underwent AT (group 1) and 22 children underwent RME (group 2). Five children underwent both treatments (group 3). Children in group 2 were older, had a longer disease duration, a higher body mass index (BMI), a lower apnea-hypopnea index (AHI), and a lower arousal index at T0 than children in group 1. After 1 year, BMI percentile and overnight mean saturation increased in group 1 while AHI and arousal index decreased. In group 2, mean overnight saturation increased while AHI decreased. Children in group 3 displayed a significant decrease in AHI from T0 to T1. CONCLUSIONS: Our data demonstrate that both treatments help to improve OSA, and a multidisciplinary approach to treatment is suggested.

Sleep clinical record: an aid to rapid and accurate diagnosis of paediatric sleep disordered breathing.

Overnight polysomnography (PSG) is an expensive procedure which can only be used in a minority of cases, although it remains the gold standard for the diagnosis of sleep disordered breathing (SDB). The objective of this study was to develop a simple, PSG-validated tool to screen SDB, thus reducing the use of PSG. For every participant we performed PSG and a sleep clinical record was completed. The sleep clinical record consists of three items: physical examination, subjective symptoms and clinical history. The clinical history analyses behavioural and cognitive problems. All three items were used to create a sleep clinical score (SCS). We studied 279 children, mean ± SD age 6.1 ± 3.1 years, 63.8% male; 27.2% with primary snoring and 72.8% with obstructive sleep apnoea (OSA) syndrome. The SCS was higher in the OSA syndrome group compared to the primary snoring group (8.1 ± 9.6 versus 0.4 ± 0.3, p<0.005), correlated with apnoea/hypopnoea index (p=0.001) and had a sensitivity of 96.05%. Positive and negative likelihood ratios were 2.91 and 0.06, respectively. SCS may effectively be used to screen patients as candidates for PSG study for suspected OSA syndrome, and to enable those with a mild form of SDB to receive early treatment.

Headache and cognitive profile in children: a cross-sectional controlled study.

We investigated whether children affected by tension-type headache and migraine without aura, compared with a healthy control group that was matched by age, culturally and socioeconomically display a diverse intellectual functioning and have a separate "cognitive profile". A cross-sectional study was conducted from January 2006 to November 2008 at "Sapienza University" in Rome. A total of 134 children were diagnosed as being affected by either migraine without aura (93) or tension-type headache (41). On the basis of our exclusion/inclusion criteria, we enrolled 82 of these 134 children, 63 of whom were affected by migraine without aura and 19 by tension-type headache. On entry, cognitive functions were assessed in both the affected subjects and the control group by the Wechsler Intelligence Scale for Children-revised. Significant differences were found between the headache and control groups in the mean total intelligence quotient and verbal intelligence quotient scores (p < 0.001). Significant negative correlations were found between the total intelligence quotient, verbal intelligence quotient, performance intelligence quotient and the frequency of attacks (r = -0.55 and p < 0.001, r = -0.61 and p < 0.001, r = -0.29 and p < 0.01, respectively), as well as between the total intelligence quotient score and the age at headache onset (r = 0.234, p < 0.05). Our results suggest that the cognitive profile of children affected by headache should be assessed at the first child neurology outpatient observation. From a therapeutic point of view, although within a normal range, the abilities most likely to be less brilliant in such children are verbal skills.

Migraine treatment in developmental age: guidelines update.

There is a serious lack of controlled studies on the pharmacological treatment of primary migraine in the developmental age; there is, consequently, an urgent need for new, evidence-based approaches to this long-neglected field of research. Moreover, previous studies have stated that the placebo response is greater in pediatric patients than in adults and that a reduction in the attack frequency in the absence of any pharmacological treatment is observed more frequently in pediatric migraine patients than in adults. Besides these preliminary considerations, the shorter duration of migraine attacks and other characteristic semeiological features of the clinical picture in children are such that the design of randomized controlled trial (RCT) is more problematic in the developmental age than in the adult. Bearing in mind all these weak points, the aim of this review was to summarize and update recent guidelines for the treatment of primary migraine in children and adolescents. The most recent guidelines are those published by the Italian Society for the study of Headache, the French Society for the study of Migraine and Headache, and the American Academy of Neurology. We have incorporated into these guidelines the results from the few, recent RCTs, clinical controlled trials, open-label studies, meta-analyses and reviews that have been published since 2004; owing to the lack of strong evidence in this field of research, we have sometimes even mentioned pilot non-controlled studies, case series and expert opinions. Lastly, evidence was classified and the recommendations were categorized according to different levels.

Chemical-Induced Read-Through at Premature Termination Codons Determined by a Rapid Dual-Fluorescence System Based on S. cerevisiae.

Nonsense mutations generate in-frame stop codons in mRNA leading to a premature arrest of translation. Functional consequences of premature termination codons (PTCs) include the synthesis of truncated proteins with loss of protein function causing severe inherited or acquired diseases. A therapeutic approach has been recently developed that is based on the use of chemical agents with the ability to suppress PTCs (read-through) restoring the synthesis of a functional full-length protein. Research interest for compounds able to induce read-through requires an efficient high throughput large scale screening system. We present a rapid, sensitive and quantitative method based on a dual-fluorescence reporter expressed in the yeast Saccharomyces cerevisiae to monitor and quantitate read-through at PTCs. We have shown that our novel system works equally well in detecting read-through at all three PTCs UGA, UAG and UAA.

Tobramycin is a suppressor of premature termination codons.

Premature translation terminations (PTCs) constitute the molecular basis of many genetic diseases, including cystic fibrosis, as they lead to the synthesis of truncated non-functional or partially functional protein. Suppression of translation terminations at PTCs (read-through) has been developed as a therapeutic strategy to restore full-length protein in several genetic diseases. Phenotypic consequences of PTCs can be exacerbated by the nonsense-mediated mRNA decay (NMD) pathway that detects and degrades mRNA containing PTC. Modulation of NMD, therefore, is also of interest as a potential target for the suppression therapy. Tobramycin is an aminoglycoside antibiotic, normally used to treat Pseudomonas aeruginosa pulmonary infection in CF patients. In the present study, by using yeast as a genetic system, we have examined the ability of Tobramycin to suppress PTCs as a function of the presence or absence of NMD. Results demonstrate that Tobramycin exhibits read-through ability on PTCs and preferentially in absence of NMD.

Sleep cyclic alternating pattern analysis in infants with apparent life-threatening events: a daytime polysomnographic study.

OBJECTIVE: Non-REM sleep is characterized by a physiologic oscillating pattern that exhibits different levels of arousal, coded as cyclic alternating pattern. The aim of this study was to analyze the development of cyclic alternating pattern parameters in a group of infants with apparent life-threatening events. METHODS: A total of 26 infants with apparent life-threatening events (14 females, mean age 3.4 months, 2.37 S.D., age range 0.5-9 months) were studied while they slept in the morning between feedings, by means of a 3-h video-electroencephalographic-polygraphic recording. Sleep was visually scored using standard criteria. The control group was composed of 36 healthy infants (16 females, mean age 3.2 months, 2.17 S.D., age range 0.5-9 months). RESULTS: Children with apparent life-threatening events showed an increased frequency of periodic breathing, gastroesofageal reflux and of other risk conditions. They presented also an increased obstructive apnoea/hypopnea index. A full NREM sleep development was found in a significantly smaller percentage of patients, and they showed a significant reduction of the percentage of REM sleep, of cyclic alternating pattern A1 subtypes, an increased percentage of A2 and A3 subtypes and increased index of A2, A3 subtypes and arousal, compared to normal controls. Cyclic alternating pattern rate showed a significant positive correlation with age, only in controls. CONCLUSIONS: Our results show a higher level of arousal and an increased non-REM sleep discontinuity in babies with apparent life-threatening events, compared to controls. SIGNIFICANCE: The enhanced mechanism of arousal might counteract life-threatening events and represent an important neurophysiologic distinction from future victims of sudden infant death syndrome who also experience similar events.

Neurocognitive assessment and sleep analysis in children with sleep-disordered breathing.

OBJECTIVE: To assess possible correlations between intelligence quotient (IQ) and attention deficit hyperactive disorder (ADHD) rating scale values and sleep (including cyclic alternating patterns analysis) and respiratory parameters in children with sleep-disordered breathing (SDB). METHODS: Thirteen children who satisfied the criteria for primary snoring and 31 children for obstructive sleep apnea syndrome (OSAS) underwent polysomnography in a standard laboratory setting and a neurocognitive assessment. Sixty normal controls recruited from two schools underwent the neurocognitive assessment. RESULTS: The IQ estimates of controls were higher and the ADHD rating scale scores lower than those of children with SDB. Children with OSAS had a higher REM sleep latency and arousal index as well as a lower N3 and A mean duration than children who snored. In our sample of children with SDB, the percentage of wakefulness after sleep onset, of N1, of A2, of arousal and A2 index correlated positively with global intelligence. Total and hyperactivity scores correlated positively with the A2 index. Regression analysis mostly confirmed the correlations between neurocognitive measures and sleep parameters and further demonstrated a negative correlation between the hyperactivity rating score and oxygen saturation during the night. CONCLUSIONS: Our results support the hypothesis that arousal is a defensive mechanism that may preserve cognitive function by counteracting the respiratory events, at the expense of sleep maintenance and NREM sleep instability. SIGNIFICANCE: We believe that our study makes an interesting contribution to research on the relationship between sleep fragmentation and cognitive function.

Sleep cyclic alternating pattern analysis in healthy children during the first year of life: a daytime polysomnographic study.

We evaluated the cyclic alternating pattern (CAP) during the first year of life in order to obtain information on the maturation of arousal mechanisms during NREM sleep and to provide normative data for CAP parameters in this age range (5-16months). Eleven healthy children (mean age 7.9±3.3months, seven boys) were studied while they slept in the morning. They underwent a 3-h video-EEG-polysomnographic recording at the Pediatric Sleep Unit of Sant'Andrea Hospital in Rome, Italy. Sleep was scored visually for sleep architecture and CAP analysis using standard criteria. Our results were complemented by CAP data from a previous sample of healthy infants (2-4months), studied when they slept during the morning, in order to correlate CAP parameters with age. The total sample comprised 24 children. The sleep period was approximately 2h, with a first REM latency of about 30min, and a clear distinction between stages N1, N2, and N3. The arousal index was 12±2.1 events/hour of sleep. The total CAP rate was 23.7±7.6%, and it increased progressively with the deepness of sleep; the highest values were observed during stage N3 and the lowest values during stage N1. A1 phases were the most numerous (78.2%), followed by A2 (14%) and A3 (7.7%) phases. The A1 index was higher than the A2 and A3 indices, whereas the mean duration of B was higher than that of A. The correlation showed that the CAP rate, A1, A2, A3 indices, A2, A3 percentages, and the average duration of B increased with age, whereas the A1 percentage decreased. We provide the first data on CAP analysis in children aged 5-16months, studied when they slept during the morning. Our results confirm the trend toward an increase in CAP rate during the first year of life. In addition, we observed a progressive increase in CAP rate with deepness of sleep, and with age, reflecting maturation of slow-wave activity. The decreased percentage of A1 subtypes may reflect the maturation of arousability.

"Electro-clinical syndromes" with onset in paediatric age: the highlights of the clinical-EEG, genetic and therapeutic advances.

The genetic causes underlying epilepsy remain largely unknown, and the impact of available genetic data on the nosology of epilepsy is still limited. Thus, at present, classification of epileptic disorders should be mainly based on electroclinical features. Electro-clinical syndrome is a term used to identify a group of clinical entities showing a cluster of electro-clinical characteristics, with signs and symptoms that together define a distinctive, recognizable, clinical disorder. These often become the focus of treatment trials as well as of genetic, neuropsychological, and neuroimaging investigations. They are distinctive disorders identifiable on the basis of a typical age onset, specific EEG characteristics, seizure types, and often other features which, when taken together, permit a specific diagnosis which, in turn, often has implications for treatment, management, and prognosis. Each electro-clinical syndrome can be classified according to age at onset, cognitive and developmental antecedents and consequences, motor and sensory examinations, EEG features, provoking or triggering factors, and patterns of seizure occurrence with respect to sleep. Therefore, according to the age at onset, here we review the more frequently observed paediatric electro-clinical syndrome from their clinical-EEG, genetic and therapeutic point of views.

Visual scoring of sleep: A comparison between the Rechtschaffen and Kales criteria and the American Academy of Sleep Medicine criteria in a pediatric population with obstructive sleep apnea syndrome.

OBJECTIVE: To compare the new American Academy of Sleep Medicine (AASM) criteria for scoring sleep with the previous Rechtschaffen and Kales (R&K) criteria in a cohort of children with primary snoring, obstructive sleep apnea syndrome (OSAS) and normal controls. METHODS: Polysomnography was performed in 26 consecutive children with primary snoring (13 males, mean age 6.2 years, SD 3.2), in 39 with OSAS (24 males, mean age 6.1 years, SD 3.0), and in 10 age-matched normal controls. RESULTS: Compared to the other groups, OSAS children showed a lower percentage of slow-wave sleep, using both R&K and AASM criteria; they also showed a higher percentage of stage shifts, and N1, using the AASM criteria. Children with primary snoring showed a higher percentage of N1, compared to controls. CONCLUSIONS: These results indicate that the use of the new AASM criteria seem to disclose more differences in sleep parameters than the R&K rules in children with OSAS. SIGNIFICANCE: The AASM criteria seem to disclose a high degree of sleep fragmentation in children with OSAS, mostly related to the repeated occurrence of N1.

Diffuse subcortical band heterotopia, periodic limb movements during sleep and a novel "de novo" mutation in the DCX gene.

Mutations of the DCX gene (Xp22.3) cause X-linked lissencephaly in males and double cortex syndrome (DCS) or subcortical band heterotopia (SBH) in females. SBH is characterized by bilateral bands of grey matter interposed in the white matter between the cortex and the lateral ventricles. The main clinical manifestation in patients with SBH is epilepsy, which may be partial or generalized and is intractable in approximately 65% of the patients. An association of periodic limb movements (PLMs) and SBH has not been documented previously. We describe a 2-year-old girl affected by SBH with epilepsy and periodic limb movements (PLMs), in whom a novel "de novo" missense substitution, Met1Val (M1V), was identified in the DCX gene. Physiopathological links between PLMs and SBH are discussed.