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Introduction: Respiratory infections are one of the leading causes of morbidity and mortality worldwide, mainly in children, immunocompromised people, and the elderly. Several respiratory viruses can induce intestinal inflammation and alterations in intestinal microbiota composition. Human metapneumovirus (HMPV) is one of the major respiratory viruses contributing to infant mortality in children under 5 years of age worldwide, and the effect of this infection at the gut level has not been studied. Methods: Here, we evaluated the distal effects of HMPV infection on intestinal microbiota and inflammation in a murine model, analyzing several post-infection times (days 1, 3, and 5). Six to eight-week-old C57BL/6 mice were infected intranasally with HMPV, and mice inoculated with a non-infectious supernatant (Mock) were used as a control group. Results: We did not detect HMPV viral load in the intestine, but we observed significant changes in the transcription of IFN-γ in the colon, analyzed by qPCR, at day 1 post-infection as compared to the control group. Furthermore, we analyzed the frequencies of different innate and adaptive immune cells in the colonic lamina propria, using flow cytometry. The frequency of monocyte populations was altered in the colon of HMPV -infected mice at days 1 and 3, with no significant difference from control mice at day 5 post-infection. Moreover, colonic CD8+ T cells and memory precursor effector CD8+ T cells were significantly increased in HMPV-infected mice at day 5, suggesting that HMPV may also alter intestinal adaptive immunity. Additionally, we did not find alterations in antimicrobial peptide expression, the frequency of colonic IgA+ plasma cells, and levels of fecal IgA. Some minor alterations in the fecal microbiota composition of HMPV -infected mice were detected using 16s rRNA sequencing. However, no significant differences were found in ß-diversity and relative abundance at the genus level. Discussion: To our knowledge, this is the first report describing the alterations in intestinal immunity following respiratory infection with HMPV infection. These effects do not seem to be mediated by direct viral infection in the intestinal tract. Our results indicate that HMPV can affect colonic innate and adaptive immunity but does not significantly alter the microbiota composition, and further research is required to understand the mechanisms inducing these distal effects in the intestine.
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Metapneumovirus , Infecções por Paramyxoviridae , Infecções Respiratórias , Criança , Camundongos , Humanos , Animais , Pré-Escolar , Idoso , Linfócitos T CD8-Positivos , RNA Ribossômico 16S , Camundongos Endogâmicos C57BL , Imunidade Adaptativa , Inflamação , Imunoglobulina ARESUMO
Around 155 million people worldwide suffer from asthma. In Chile, the prevalence of this disease in children is around 15% and has a high impact in the health system. Studies suggest that asthma is caused by multiple factors, including host genetics, antibiotic use, and the development of the airway microbiota. Here, we used 16S rRNA high-throughput sequencing to characterize the nasal and oral mucosae of 63 asthmatic and 89 healthy children (152 samples) from Santiago, Chile. We found that the nasal mucosa was dominated by a high abundance of Moraxella, Dolosigranulum, Haemophilus, Corynebacterium, Streptococcus, and Staphylococcus. In turn, the oral mucosa was characterized by a high abundance of Streptococcus, Haemophilus, Gemella, Veillonella, Neisseria, and Porphyromonas. Our results showed significantly (P < 0.001) lower alpha diversity and an over-abundance of Streptococcus (P < 0.01) in nasal samples from asthmatics compared to samples from healthy subjects. Community structure, as revealed by co-occurrence networks, showed different microbial interactions in asthmatic and healthy subjects, particularly in the nasal microbiota. The networks revealed keystone genera in each body site, including Prevotella, Leptotrichia, and Porphyromonas in the nasal microbiota, and Streptococcus, Granulicatella, and Veillonella in the oral microbiota. We also detected 51 functional pathways differentially abundant on the nasal mucosa of asthmatic subjects, although only 13 pathways were overrepresented in the asthmatic subjects (P < 0.05). We did not find any significant differences in microbial taxonomic (composition and structure) and functional diversity between the oral mucosa of asthmatic and healthy subjects. This study explores for the first time the relationships between the upper respiratory airways bacteriome and asthma in Chile. It demonstrates that the nasal cavity of children from Santiago harbors unique bacterial communities and identifies potential taxonomic and functional biomarkers of pediatric asthma.
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The lacustrine systems of La Brava and La Punta, located in the Tilopozo sector in the extreme south of Salar de Atacama, are pristine high-altitude Andean lakes found along the central Andes of South America. This shallow ecosystem suffers from permanent evaporation, leading to falling water levels, causing it to recede or disappear during the dry season. This dynamic causes physicochemical changes in lakes, such as low nutrient availability, pH change, and dissolved metals, which can influence the composition of the microbial community. In this study, we used a metataxonomic approach (16S rRNA hypervariable regions V3 to V4) to characterize the sedimentary microbiota of these lakes. To understand how the water column affects and is structured in the microbiota of these lakes, we combined the analysis of the persistence of the water column through satellite images and physicochemical characterization. Our results show a significant difference in abiotic factors and microbiota composition between La Punta and La Brava lakes. In addition, microbiota analysis revealed compositional changes in the ecological disaggregation (main and isolated bodies) and antagonistic changes in the abundance of certain taxa between lakes. These findings are an invaluable resource for understanding the microbiological diversity of high Andean lakes using a multidisciplinary approach that evaluates the microbiota behavior in response to abiotic factors. IMPORTANCE In this study, we analyzed the persistence of the water column through satellite images and physicochemical characterization to investigate the composition and diversity in High Andean Lake Systems in a hyperarid environment. In addition to the persistence of the water column, this approach can be used to analyze changes in the morphology of saline accumulations and persistence of snow or ice; for example, for establishing variable plant cover over time and evaluating the microbiota associated with soils with seasonal changes in plants. This makes it an ideal approach to search for novel extremophilic microorganisms with unique properties. In our case, it was used to study microorganisms capable of resisting desiccation and water restriction for a considerable period and adapting to survive in ecological niches, such as those with high UV irradiation, extreme drought, and high salt concentration.
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Lagos , Microbiota , Lagos/química , Estações do Ano , Água , RNA Ribossômico 16S/genética , AltitudeRESUMO
We study solitons in a zig-zag lattice of magnetic dipoles. The lattice comprises two sublattices of parallel chains with magnetic dipoles at their vertices. Due to orthogonal easy planes of rotation for dipoles belonging to different sublattices, the total dipolar energy of this system is separable into a sum of symmetric and chiral long-ranged interactions between the magnets where the last takes the form of Dzyaloshinskii-Moriya (DM) coupling. For a specific range of values of the offset between sublattices, the dipoles realize an equilibrium magnetic state in the lattice plane, consisting of one chain settled in an antiferromagnetic (AF) parallel configuration and the other in a collinear ferromagnetic fashion. If the offset grows beyond this value, the internal DM field stabilizes two Bloch domain walls at the edges of the AF chain. The dynamics of these solitons is studied by deriving the long-wavelength lagrangian density for the easy axis antiferromagnet. We find that the chiral couplings between sublattices give rise to an effective magnetic field that stabilizes the solitons in the antiferromagnet. When the chains displace respect to each other, an emergent Lorentz force accelerates the domain walls along the lattice.
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Chiral magnetic insulators manifest novel phases of matter where the sense of rotation of the magnetization is associated with exotic transport phenomena. Effective control of such phases and their dynamical evolution points to the search and study of chiral fields like the Dzyaloshinskii-Moriya interaction. Here we combine experiments, numerics, and theory to study a zig-zag dipolar lattice as a model of an interface between magnetic in-plane layers with a perpendicular magnetization. The zig-zag lattice comprises two parallel sublattices of dipoles with perpendicular easy plane of rotation. The dipolar energy of the system is exactly separable into a sum of symmetric and antisymmetric long-range exchange interactions between dipoles, where the antisymmetric coupling generates a nonlocal Dzyaloshinskii-Moriya field which stabilizes winding textures with the form of chiral solitons. The Dzyaloshinskii-Moriya interaction acts as a vector potential or gauge field of the magnetic current and gives rise to emergent magnetic and electric fields that allow the manifestation of the magnetoelectric effect in the system.
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Eletricidade , Fenômenos Físicos , RotaçãoRESUMO
BACKGROUND: Observational studies suggest that asthma/wheezing improves after adenotonsillectomy (AT). However, there is a paucity of randomized clinical trial (RCT) specifically studying the effects of AT in asthma/wheezing. Therefore, we conducted a post-hoc analysis of the Childhood Adenotonsillectomy Trial (CHAT), the largest RCT of AT in children with obstructive sleep apnea (OSA) to test the hypothesis that AT would result in fewer wheezing episodes. METHODS: In the CHAT study, 464 children with OSA, aged 5-9 years, were randomized to early AT (n = 226) or watchful waiting with supportive care (WWSC) (n = 227). For this post-hoc analysis, children were categorized as having "any wheezing" versus "no wheezing" at baseline and at 7 months of follow-up. A multivariate analysis was conducted to evaluate the association between "any wheezing" at follow-up and treatment group after controlling for several potential confounders. RESULTS: Children in the "any wheezing" group were predominantly black, had more allergic rhinitis, eczema, second-hand smoke exposure, body mass index, apnea-hypopnea index (AHI), and had lower maternal education and family income than those in the "no wheezing group." In the AT arm, the prevalence of wheezing significantly decreased from baseline to follow-up (at 7 months of the intervention) (47% vs. 21.6%, p < 0.001); while in the WWSC arms did not change (45.2% vs. 43.1%, p = 0.67). In the multivariate analysis, second-hand smoke exposure, wheezing at baseline, and belong to WWSC arm (odds ratio: 3.65 [2.16-6.19]) increase the risk of wheezing at follow-up. CONCLUSION: This study demonstrated that AT decreased the risk of wheezing at 7 months of follow-up.
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Apneia Obstrutiva do Sono , Poluição por Fumaça de Tabaco , Tonsilectomia , Criança , Humanos , Adenoidectomia , Apneia Obstrutiva do Sono/cirurgia , Apneia Obstrutiva do Sono/complicações , Índice de Massa CorporalRESUMO
Salar de Atacama is located approximately 55 km south of San Pedro de Atacama in the Antofagasta region, Chile. The high UV irradiation and salt concentration and extreme drought make Salar de Atacama an ideal site to search for novel soil microorganisms with unique properties. Here, we used a metataxonomic approach (16S rRNA V3-V4) to identify and characterize the soil microbiota associated with different surface azonal vegetation formations, including strict hygrophiles (Baccharis juncea, Juncus balticus, and Schoenoplectus americanus), transitional hygrophiles (Distichlis spicata, Lycium humile, and Tessaria absinthioides), and their various combinations. We detected compositional differences among the soil surface microbiota associated with each plant formation in the sampling area. There were changes in soil microbial phylogenetic diversity from the strict to the transitional hygrophiles. Moreover, we found alterations in the abundance of bacterial phyla and genera. Halobacteriota and Actinobacteriota might have facilitated water uptake by the transitional hygrophiles. Our findings helped to elucidate the microbiota of Salar de Atacama and associate them with the strict and transitional hygrophiles indigenous to the region. These findings could be highly relevant to future research on the symbiotic relationships between microbiota and salt-tolerant plants in the face of climate change-induced desertification. IMPORTANCE The study of the composition and diversity of the wetland soil microbiota associated with hygrophilous plants in a desert ecosystem of the high Puna in northern Chile makes it an ideal approach to search for novel extremophilic microorganisms with unique properties. These microorganisms are adapted to survive in ecological niches, such as those with high UV irradiation, extreme drought, and high salt concentration; they can be applied in various fields, such as biotechnology and astrobiology, and industries, including the pharmaceutical, food, agricultural, biofuel, cosmetic, and textile industries. These microorganisms can also be used for ecological conservation and restoration. Extreme ecosystems are a unique biological resource and biodiversity hot spots that play a crucial role in maintaining environmental sustainability. The findings could be highly relevant to future research on the symbiotic relationships between microbiota and extreme-environment-tolerant plants in the face of climate change-induced desertification.
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Microbiota , Microbiologia do Solo , Áreas Alagadas , Bactérias/genética , Microbiota/genética , Filogenia , Plantas , RNA Ribossômico 16S/genéticaRESUMO
BACKGROUND: Clinical simulation allows the acquisition of procedural skills among medical students. The anticipatory study of these skills may improve the efficiency of simulation sessions. Aim: To Compare two anticipatory study guides in the simulation of airway management, in a cohort of medical students from Chile. MATERIAL AND METHODS: Fifth year medical students were randomly assigned to prepare the simulation of tracheal intubation with a theoretical guide, an audiovisual guide, and a control group without study. The skills acquired were evaluated in a simulated scenario. RESULTS: All groups increased their successful orotracheal intubation (OTI) rate and decreased the time to achieve a successful OTI after each attempt. The study group with a theoretical guide had the higher rate of success in the 1st OTI attempt without feedback. In contrast, the group without any anticipatory study had more failed attempts (1st and 2nd attempt), achieving their first successful OTI in the 3rd attempt after feedback. Conclusions: Study guides improve practice effectiveness. Our results indicate that the best results are obtained by simulation accompanied with immediate directed feedback and opportunities to repeat the procedures, independent of the type of anticipatory study.
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Humanos , Estudantes de Medicina , Chile , Intubação Intratraqueal/métodosRESUMO
BACKGROUND: Clinical simulation allows the acquisition of procedural skills among medical students. The anticipatory study of these skills may improve the efficiency of simulation sessions. AIM: To Compare two anticipatory study guides in the simulation of airway management, in a cohort of medical students from Chile. MATERIAL AND METHODS: Fifth year medical students were randomly assigned to prepare the simulation of tracheal intubation with a theoretical guide, an audiovisual guide, and a control group without study. The skills acquired were evaluated in a simulated scenario. RESULTS: All groups increased their successful orotracheal intubation (OTI) rate and decreased the time to achieve a successful OTI after each attempt. The study group with a theoretical guide had the higher rate of success in the 1st OTI attempt without feedback. In contrast, the group without any anticipatory study had more failed attempts (1st and 2nd attempt), achieving their first successful OTI in the 3rd attempt after feedback. CONCLUSIONS: Study guides improve practice effectiveness. Our results indicate that the best results are obtained by simulation accompanied with immediate directed feedback and opportunities to repeat the procedures, independent of the type of anticipatory study.
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Estudantes de Medicina , Chile , Humanos , Intubação Intratraqueal/métodosRESUMO
A nonvibrating magnetic granular system is studied by using a time series approach. The system consists of steel balls confined inside a circular wall that surrounds a glass plate. Kinetic energy is provided to the particles by the application of an external vertical time-dependent magnetic field of different amplitudes. We carried out a characterization of the system dynamics through the measurement of the correlations present in the time series of positions, in the x-direction, of each particle. In particular, by performing Fourier spectral analysis, we find that the time series are fractal and scale invariant, in such a way that the corresponding Fourier power spectra follow a power law [Formula: see text], with [Formula: see text]. More specifically, we find that the values of [Formula: see text], and therefore the strength of the correlations, increase as the magnetic field also increases. In this way, the present system constitutes an experimental model to generate correlated random walks. Additionally, we show how the introduction of a constant magnetic field breaks down this scale invariance property in the positions of each particle. Finally, we confirm the above results by applying detrended fluctuation analysis.
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Campylobacter spp., especially C. jejuni, are recognized worldwide as the bacterial species that most commonly cause food-related diarrhea. C. jejuni possesses many different virulence factors, has the ability to survive in different reservoirs, and has shown among isolates the emergence of Antimicrobial Resistance (AMR). Genome association analyses of this bacterial pathogen have contributed to a better understanding of its pathogenic and AMR associated determinants. However, the epidemiological information of these bacteria in Latin American countries is scarce and no genomic information is available in public databases from isolates in these countries. Considering this, the present study is aimed to describe the genomic traits from representative Campylobacter spp. strains recovered from faecal samples of patients with acute diarrhoea from Valparaíso, Chile. Campylobacter spp. was detected from the faeces of 28 (8%) out of 350 patients with acute diarrhoea, mainly from young adults and children, and 26 (93%) of the isolates corresponded to C. jejuni. 63% of the isolates were resistant to ciprofloxacin, 25.9% to tetracycline, and 3.5% to erythromycin. Three isolates were selected for WGS on the basis of their flaA-RFLP genotype. They belonged to the multilocus sequence typing (MLST) clonal clomplex (CC) 21(PUCV-1), CC-48 (PUCV-3), and CC-353 (PUCV-2) and presented several putative virulence genes, including the Type IV and Type VI Secretion Systems, as well as AMR-associated genes in agreement with their susceptibility pattern. On the basis of the wgMLST, they were linked to strains from poultry and ruminants. These are the first genomes of Chilean C. jejuni isolates available in public databases and they provide relevant information about the C. jejuni isolates associated with human infection in this country.
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Técnicas de Tipagem Bacteriana , Infecções por Campylobacter , Campylobacter jejuni , Farmacorresistência Bacteriana , Genoma Bacteriano , Tipagem de Sequências Multilocus , Fatores de Virulência/genética , Adulto , Idoso , Infecções por Campylobacter/epidemiologia , Infecções por Campylobacter/genética , Campylobacter jejuni/classificação , Campylobacter jejuni/genética , Campylobacter jejuni/isolamento & purificação , Campylobacter jejuni/patogenicidade , Criança , Chile/epidemiologia , Fezes , Feminino , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
We apply the singular value decomposition (SVD) method, based on normal-mode analysis, to decompose the spectra of finite random matrices of standard Gaussian ensembles in trend and fluctuation modes. We use the fact that the fluctuation modes are scale invariant and follow a power law, to characterize the transition between the extreme regular and chaotic cases. Thereby, we quantify the quantum chaos in systems described by random matrix theory in a direct way, without performing any previous unfolding procedure, and therefore, avoiding possible artifacts.
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STUDY OBJECTIVES: Children with the obstructive sleep apnea (OSA) have impaired upper airway two-point discrimination compared to controls. In addition, blunted vibration threshold detection (VT) in the palate has been recognized in adults with OSA, but has not been studied in children. Both findings are indicative of a defect in the afferent limb of the upper airway dilator reflex that could prevent upper airway dilation secondary to airway loading, resulting in airway collapse. We hypothesized that children with OSA have impaired palate VT compared to controls, and that this improves after OSA treatment. METHODS: Case-control study. Children with OSA and healthy non-snoring controls underwent polysomnography and palate VT measurements. Children with OSA were retested after adenotonsillectomy. RESULTS: 29 children with OSA (median [interquartile range] age = 9.5 [7.5-12.6] years, obstructive apnea-hypopnea index [OAHI] = 11.3 [5.7-19.5] events/h, BMI z = 1.8 [1.3-2.1]) and 32 controls (age = 11.2 [9.3-13.5] years, P = 0.1; OAHI = 0.5 [0.1-0.7] events/h, P < 0.001; BMI z = 1 [0.3-1.7], P = 0.004) were tested. OSA palate VT (1.0 [0.8-1.5] vibration units) was similar to that of controls (1 [0.8-1.3], P = 0.37). 20 children with OSA were retested 4.4 (3.2-7.1) months after treatment. OAHI decreased from 13.1 (5.8-19) to 0.6 (0.2-2.5) events per hour (P < 0.001) postoperatively, but palate VT did not change (before = 1 [0.7-1.5], after = 1.2 [0.8-1.4], P = 0.37). CONCLUSIONS: Children with OSA and controls have similar palate VT. Unlike in adults, palate VT does not seem to be affected by childhood OSA.
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Palato/fisiopatologia , Limiar Sensorial/fisiologia , Apneia Obstrutiva do Sono/fisiopatologia , Vibração , Adenoidectomia , Adolescente , Estudos de Casos e Controles , Criança , Feminino , Humanos , Masculino , Polissonografia , Método Simples-Cego , Apneia Obstrutiva do Sono/cirurgia , Tonsilectomia , Resultado do TratamentoRESUMO
STUDY OBJECTIVES: Children with craniofacial anomalies are a heterogeneous group at high risk for obstructive sleep apnea (OSA). However, the prevalence and structural predictors of OSA in this population are unknown. We hypothesized that infants with micrognathia would have more significant OSA than those with isolated cleft palate ± cleft lip (ICP), and those with ICP would have more significant OSA than controls. We postulated that OSA severity would correlate with reduced mandibular size, neurodevelopmental scores, and growth. METHODS: Prospective cohort study. 15 infants with ICP, 19 with micrognathia, and 9 controls were recruited for polysomnograms, neurodevelopmental testing, cephalometrics (ICP and micrognathia groups) at baseline and a follow-up at 6 mo. RESULTS: Baseline apnea-hypopnea index (AHI) [median (range)] of the micrognathia group [20.1 events/h (0.8, 54.7)] was greater than ICP [3.2 (0.3, 30.7)] or controls [3.1 (0.5, 23.3)] (p = 0.001). Polysomnographic findings were similar between ICP and controls. Controls had a greater AHI than previously reported in the literature. Cephalometric measures of both midface hypoplasia and micrognathia correlated with OSA severity. Neurodevelopment was similar among groups. OSA improved with growth in participants with ICP and postoperatively in infants with micrognathia. CONCLUSIONS: Micrognathia, but not ICP, was associated with more significant OSA compared to controls. Both midface and mandibular hypoplasia contribute to OSA in these populations. OSA improved after surgical correction in most infants with micrognathia, and improved without intervention before palate repair in infants with ICP.
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Fissura Palatina/epidemiologia , Micrognatismo/epidemiologia , Apneia Obstrutiva do Sono/epidemiologia , Estudos de Coortes , Comorbidade , Feminino , Seguimentos , Humanos , Lactente , Masculino , Philadelphia/epidemiologia , Polissonografia , Prevalência , Estudos Prospectivos , Índice de Gravidade de DoençaRESUMO
We studied experimentally a model of a glass-forming liquid on the basis of a nonvibrating magnetic granular system under an unsteady magnetic field. A sudden quenching was produced that drove the system from a liquid state to a different final state with lower temperature; the latter could be a liquid state or a solid state. We determined the mean-squared displacement in temporal windows to obtain the dynamic evolution of the system, and we determined the radial distribution function to obtain its structural characteristics. The results were analyzed using the intermediate scattering function and the effective potential between two particles. We observed that when quenching drives the system to a final state in the liquid phase far from the glass-transition temperature, equilibration occurs very quickly. When the final state has a temperature far below the glass-transition temperature, the system reaches its equilibrium state very quickly. In contrast, when the final state has an intermediate temperature but is below that corresponding to the glass transition, the system falls into a state that evolves slowly, presenting aging. The system evolves by an aging process toward more ordered states. However, after a waiting time, the dynamic behavior changes. It was observed that some particles get close enough to overpass the repulsive interactions and form small stable aggregates. In the effective potential curves, it was observed that the emergence of a second effective well due to the attraction quickly evolves and results in a deeper well than the initial effective well due to the repulsion. With the increase in time, more particles fall in the attractive well forming inhomogeneities, which produce a frustration in the aging process.
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STUDY OBJECTIVES: Children with obstructive sleep apnea syndrome (OSAS) often experience periods of hypercapnia during sleep, a potent stimulator of cerebral blood flow (CBF). Considering this hypercapnia exposure during sleep, it is possible that children with OSAS have abnormal CBF responses to hypercapnia even during wakefulness. Therefore, we hypothesized that children with OSAS have blunted CBF response to hypercapnia during wakefulness, compared to snorers and controls. METHODS: CBF changes during hypercapnic ventilatory response (HCVR) were tested in children with OSAS, snorers, and healthy controls using diffuse correlation spectroscopy (DCS). Peak CBF changes with respect to pre-hypercapnic baseline were measured for each group. The study was conducted at an academic pediatric sleep center. RESULTS: Twelve children with OSAS (aged 10.1 ± 2.5 [mean ± standard deviation] y, obstructive apnea hypopnea index [AHI] = 9.4 [5.1-15.4] [median, interquartile range] events/hour), eight snorers (11 ± 3 y, 0.5 [0-1.3] events/hour), and 10 controls (11.4 ± 2.6 y, 0.3 [0.2-0.4] events/hour) were studied. The fractional CBF change during hypercapnia, normalized to the change in end-tidal carbon dioxide, was significantly higher in controls (9 ± 1.8 %/mmHg) compared to OSAS (7.1 ± 1.5, P = 0.023) and snorers (6.7 ± 1.9, P = 0.025). CONCLUSIONS: Children with OSAS and snorers have blunted CBF response to hypercapnia during wakefulness compared to controls. Noninvasive DCS blood flow measurements of hypercapnic reactivity offer insights into physiopathology of OSAS in children, which could lead to further understanding about the central nervous system complications of OSAS.
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Circulação Cerebrovascular/fisiologia , Hipercapnia/complicações , Hipercapnia/fisiopatologia , Apneia Obstrutiva do Sono/complicações , Adolescente , Dióxido de Carbono/sangue , Criança , Feminino , Humanos , Hipercapnia/sangue , Masculino , Polissonografia , Sono , Apneia Obstrutiva do Sono/sangue , Apneia Obstrutiva do Sono/fisiopatologia , Ronco/sangue , Ronco/complicações , Ronco/fisiopatologia , VigíliaRESUMO
STUDY OBJECTIVES: The obstructive sleep apnea syndrome (OSAS) is more prevalent in ex-preterm children compared to the general pediatric population. However, it is unknown whether OSAS in ex-preterm children is associated with specific perinatal risk factors. This multicenter cohort study aimed to determine perinatal factors associated with OSAS at school age. METHODS: 197 ex-preterm (500-1,250 g) children aged 5-12 y who participated as neonates in a double-blind, randomized clinical trial of caffeine versus placebo (Caffeine for Apnea of Prematurity) underwent comprehensive ambulatory polysomnography. A negative binomial regression model was used to identify perinatal risk factors associated with OSAS. RESULTS: 19 children had OSAS (9.6%). Chorioamnionitis and multiple gestation were positively associated with OSAS with P values of 0.014 and 0.03, respectively. Maternal white race (P = 0.047) and maternal age (P = 0.002) were negatively associated with OSAS. Other risk factors, such as birth weight, Apgar score at 5 min, antenatal corticosteroids, delivery route, and sex were not significant. CONCLUSIONS: OSAS is very frequent, and is associated with chorioamnionitis and multiple gestation in ex-preterm children. Those born to older white mothers appear to be protected. We speculate that the former may be due to systemic inflammation and the latter to a higher socio-economic status. COMMENTARY: A commentary on this article appears in this issue on page 721.