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BACKGROUND: Observational studies have shown that higher cereal fiber intake is associated with reduced type 2 diabetes risk. However, it remains uncertain whether this association is causal. OBJECTIVE: This study evaluated the feasibility of an intervention to increase cereal fiber intake in children using breakfast cereals. METHODS: The study was a 2-arm parallel group randomized controlled trial in 9-10-y-old children, who received free supplies of high-fiber breakfast cereals (>3.5 g/portion) or low-fiber breakfast cereals (<1.0 g/portion) to eat daily for 1 mo with behavioral support to promote adherence. Children provided baseline and 1-mo fasting blood samples, physical measurements, and 24-h dietary recalls. The primary outcome was the group difference in change in plasma total alkylresorcinol (AR) concentration; secondary outcomes were group differences in nutrient intakes and adiposity indices. Analyses (complete case and multiple imputation) were conducted by regressing the final AR concentration on baseline AR in models adjusted for sex, ethnicity, age, and school (random effect). RESULTS: Two-hundred seventy-two children were randomly assigned (137 receiving a low-fiber and 135 a high-fiber diet) and 193 (71%) provided fasting blood samples at baseline and follow-up. Among randomized participants, median (IQR) of baseline AR was 43.1 (24.6-85.5) nmol/L and of cereal fiber intake was 4.5 (2.7-6.4) g; 87% of participants reported consuming the cereal on most or all days. Compared with changes in the low-fiber group, the high-fiber group had greater increases in AR (40.7 nmol/L; 95% CI: 21.7, 59.8 nmol/L, P < 0.0001) and in reported cereal fiber intake (2.9g/d; 95% CI: 2.0, 3.7 g; P < 0.0001). There were no appreciable differences in other secondary outcomes. CONCLUSIONS: We have developed a simple and acceptable nutritional intervention that increases markers of daily cereal fiber intake in children. This intervention could be used to test whether increases in cereal fiber intake in children might reduce insulin resistance. This trial was registered at www.isrctn.com as ISRCTN33260236.
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Fibras na Dieta/administração & dosagem , Grão Comestível/química , Criança , Fibras na Dieta/análise , Estudos de Viabilidade , Feminino , Humanos , MasculinoRESUMO
BACKGROUND: With evidence of rising need around mental health in young people, cuts in specialist health provision and increasing recognition of the central role of schools in supporting young people with mental health problems, it is important to understand the provision of mental health support currently available in schools, the nature of the relationship with health and other providers of child and adolescent mental health (CAMH) services, and what are the key barriers to accessing support. METHOD: The study was a convenience sample survey of 577 school staff from 341 schools in England. Participants completed an online survey about the provision of specialist mental health support in their school, including what support is available, who provides it, and perceived barriers to supporting the mental health of young people. Data were linked to publicly available data on school characteristics. RESULTS: Over two thirds of schools reported having some specialist support available, with specialist provision more common in secondary schools. Staff training and whole-school approaches were the most frequently employed specific approaches. Support was most often provided by educational psychologists, followed by counsellors. School staff particularly valued support and feedback within the schools context. The most frequently cited barrier to mental health support was the limited capacity of specialist CAMH services. CONCLUSIONS: The results suggest a need to enhance the availability of specialist support for mental health both within schools and in CAMH services.
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BACKGROUND: Regular breakfast consumption may protect against type 2 diabetes risk in adults but little is known about its influence on type 2 diabetes risk markers in children. We investigated the associations between breakfast consumption (frequency and content) and risk markers for type 2 diabetes (particularly insulin resistance and glycaemia) and cardiovascular disease in children. METHODS AND FINDINGS: We conducted a cross-sectional study of 4,116 UK primary school children aged 9-10 years. Participants provided information on breakfast frequency, had measurements of body composition, and gave fasting blood samples for measurements of blood lipids, insulin, glucose, and glycated haemoglobin (HbA1c). A subgroup of 2,004 children also completed a 24-hour dietary recall. Among 4,116 children studied, 3,056 (74%) ate breakfast daily, 450 (11%) most days, 372 (9%) some days, and 238 (6%) not usually. Graded associations between breakfast frequency and risk markers were observed; children who reported not usually having breakfast had higher fasting insulin (percent difference 26.4%, 95% CI 16.6%-37.0%), insulin resistance (percent difference 26.7%, 95% CI 17.0%-37.2%), HbA1c (percent difference 1.2%, 95% CI 0.4%-2.0%), glucose (percent difference 1.0%, 95% CI 0.0%-2.0%), and urate (percent difference 6%, 95% CI 3%-10%) than those who reported having breakfast daily; these differences were little affected by adjustment for adiposity, socioeconomic status, and physical activity levels. When the higher levels of triglyceride, systolic blood pressure, and C-reactive protein for those who usually did not eat breakfast relative to those who ate breakfast daily were adjusted for adiposity, the differences were no longer significant. Children eating a high fibre cereal breakfast had lower insulin resistance than those eating other breakfast types (p for heterogeneity <0.01). Differences in nutrient intakes between breakfast frequency groups did not account for the differences in type 2 diabetes markers. CONCLUSIONS: Children who ate breakfast daily, particularly a high fibre cereal breakfast, had a more favourable type 2 diabetes risk profile. Trials are needed to quantify the protective effect of breakfast on emerging type 2 diabetes risk. Please see later in the article for the Editors' Summary.
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Desjejum/etnologia , Diabetes Mellitus Tipo 2/etnologia , Diabetes Mellitus Tipo 2/prevenção & controle , Comportamento Alimentar/etnologia , Nível de Saúde , Glicemia/metabolismo , Desjejum/fisiologia , Criança , Estudos Transversais , Diabetes Mellitus Tipo 2/sangue , Inglaterra/etnologia , Comportamento Alimentar/fisiologia , Feminino , Humanos , Masculino , Fatores de Risco , Fatores SocioeconômicosRESUMO
Gorham's Cave is located in the British territory of Gibraltar in the southernmost end of the Iberian Peninsula. Recent excavations, which began in 1997, have exposed an 18 m archaeological sequence that covered the last evidence of Neanderthal occupation and the first evidence of modern human occupation in the cave. By applying the Mutual Climatic Range method on the amphibian and reptile assemblages, we propose here new quantitative data on the terrestrial climatic conditions throughout the latest Pleistocene sequence of Gorham's Cave. In comparison with current climatic data, all mean annual temperatures were about 1.6-1.8 degrees C lower in this region. Winters were colder and summers were similar to today. Mean annual precipitation was slightly lower, but according to the Aridity Index of Gaussen there were only four dry months during the latest Pleistocene as opposed to five dry months today during the summer. The climate was Mediterranean and semi-arid (according to the Aridity Index of Dantin-Revenga) or semi-humid (according to the Aridity Index of Martonne). The atmospheric temperature range was higher during the latest Pleistocene, mainly due to lower winter temperatures. Such data support recent bioclimatic models, which indicate that high rainfall levels may have been a significant factor in the late survival of Neanderthal populations in southern Iberia. The Solutrean levels of Gorham's Cave and climate records from cores in the Alboran Sea indicate increasing aridity from Marine Isotope Stage (MIS) 3-2. Because Neanderthals seem to have been associated with woodland habitats, we propose that lessening rainfall may have caused the degradation of large areas of forest and may have made late surviving Neanderthal populations more vulnerable outside southern refuges like the Rock of Gibraltar.
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Anfíbios/fisiologia , Arqueologia , Biota , Fósseis , Homem de Neandertal/fisiologia , Répteis/fisiologia , Animais , Cavernas , Clima , Ecossistema , Gibraltar , Estações do Ano , TemperaturaRESUMO
BACKGROUND: Lower circulating vitamin D 25-hydroxyvitamin D (25(OH)D) concentrations are associated with higher type 2 diabetes risk in adults, although causality remains uncertain. However, associations between 25(OH)D and type 2 diabetes risk markers in children have been little studied, particularly in ethnic minority populations. We examined whether 25(OH)D concentrations were associated with insulin resistance in children and whether lower 25(OH)D concentrations in South Asians and black African Caribbeans could contribute to their higher insulin resistance. METHODS: Cross-sectional study of 4650 UK primary school children aged 9-10 years of predominantly South Asian, black African Caribbean and white European ethnicity. Children had fasting blood measurements of circulating 25(OH)D metabolite concentrations, insulin and glucose. RESULTS: Lower 25(OH)D concentrations were observed in girls, South Asians and black African Caribbeans. In analyses adjusted for age, sex, month, ethnic group and school, circulating 25(OH)D was inversely associated with fasting insulin (-0.38%, 95% CI -0.49% to -0.27%), homoeostasis model assessment (HOMA) insulin resistance (-0.39%, 95% CI -0.50% to -0.28%) and fasting glucose (-0.03%, 95% CI -0.05% to -0.02%) per nmol/L increase in 25(OH)D; associations did not differ between ethnic groups. Ethnic differences in fasting insulin and HOMA insulin resistance (higher among South Asian and black African Caribbeans) were reduced by >40% after adjustment for circulating 25(OH)D concentrations. CONCLUSION: Circulating vitamin D was inversely associated with insulin resistance in all ethnic groups; higher insulin resistance in South Asian and black African children were partly explained by their lower vitamin D levels. Whether vitamin D supplementation can reduce emerging type 2 diabetes risk needs further evaluation.
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BACKGROUND: The influence of the family and home environment on childhood physical activity (PA) and whether this differs between ethnic groups remains uncertain. This paper investigates associations between family and home factors and childhood PA in a multi-ethnic population and explores whether associations differ between ethnic groups. METHODS: Cross-sectional study of 9-10 year-old schoolchildren, in which PA was objectively measured by Actigraph GT1 M accelerometers for ≤7 days to estimate average activity counts per minute (CPM). Information on 11 family and home environmental factors were collected from questionnaires. Associations between these factors and CPM were quantified using multi-level linear regression. Interactions with ethnicity were explored using likelihood ratio tests. RESULTS: 2071 children (mean ± SD age: 9.95 ± 0.38 years; 47.8% male) participated, including 25% white European, 28% black African-Caribbean, 24% South Asian, and 24% other ethnic origin. Family PA support and having a pet were associated with higher average CPM (adjusted mean difference: 6 (95%CI:1,10) and 13 (95%CI:3,23), respectively) while car ownership and having internet access at home were associated with lower average CPM (adjusted mean difference: -19 (95%CI:-30,-8) and -10 (95%CI:-19,0), respectively). These associations did not differ by ethnicity. Although the number of siblings showed no overall association with PA, there was some evidence of interaction with ethnicity (p for ethnicity interaction=0.04, 0.05 in a fully-adjusted model); a positive significant association with number of siblings was observed in white Europeans (per sibling CPM difference 10.3 (95% CI 1.7, 18.9)) and a positive non-significant association was observed in black African-Caribbeans (per sibling CPM difference: 3.5 (-4.2, 11.2)) while a negative, non-significant association was observed in South Asians (per sibling CPM difference -6.0 (-15.5, 3.4)). CONCLUSIONS: Some family and home environmental factors have modest associations with childhood PA and these are mostly similar across different ethnic groups. This suggests that targeting these factors in an intervention to promote PA would be relevant for children in different ethnic groups.
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Comportamento Infantil , Relações Familiares , Atividade Motora , Criança , Comportamento Infantil/etnologia , Comportamento Infantil/psicologia , Estudos Transversais , Inglaterra , Características da Família , Feminino , Inquéritos Epidemiológicos , Humanos , Internet , Masculino , Animais de Estimação , Irmãos , Fatores SocioeconômicosRESUMO
BACKGROUND: Repolarization alternans (RA) has been implicated in the pathogenesis of ventricular arrhythmias and sudden cardiac death. METHODS: We have developed a real-time, closed-loop system to record and analyze RA from multiple intracardiac leads, and deliver dynamically R-wave triggered pacing stimuli during the absolute refractory period. We have evaluated the ability of this system to control RA and reduce arrhythmia susceptibility, in vivo. RESULTS: R-wave triggered pacing can induce RA, the magnitude of which can be modulated by varying the amplitude, pulse width, and size of the pacing vector. Using a swine model (n=9), we demonstrate that to induce a 1 µV change in the alternans voltage on the body surface, coronary sinus and left ventricle leads, requires a delivered charge of 0.04±0.02, 0.05±0.025, and 0.06±0.033 µC, respectively, while to induce a one unit change of the Kscore, requires a delivered charge of 0.93±0.73, 0.32±0.29, and 0.33±0.37 µC, respectively. For all body surface and intracardiac leads, both Δ(alternans voltage) and ΔKscore between baseline and R-wave triggered paced beats increases consistently with an increase in the pacing pulse amplitude, pulse width, and vector spacing. Additionally, we show that the proposed method can be used to suppress spontaneously occurring alternans (n=7), in the presence of myocardial ischemia. Suppression of RA by pacing during the absolute refractory period results in a significant reduction in arrhythmia susceptibility, evidenced by a lower Srank score during programmed ventricular stimulation compared with baseline before ischemia. CONCLUSIONS: We have developed and evaluated a novel closed-loop method to dynamically modulate RA in a swine model. Our data suggest that suppression of RA directly reduces arrhythmia susceptibility and reinforces the concept that RA plays a critical role in the pathophysiology of arrhythmogenesis.
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Potenciais de Ação , Arritmias Cardíacas/prevenção & controle , Estimulação Cardíaca Artificial/métodos , Sistema de Condução Cardíaco/fisiopatologia , Período Refratário Eletrofisiológico , Animais , Arritmias Cardíacas/etiologia , Arritmias Cardíacas/fisiopatologia , Modelos Animais de Doenças , Frequência Cardíaca , Isquemia Miocárdica/complicações , Isquemia Miocárdica/fisiopatologia , Sus scrofa , Fatores de TempoRESUMO
Repolarization alternans (RA) has been implicated in the pathogenesis of ventricular arrhythmias and sudden cardiac death. We developed a 12-lead, blue-tooth/Smart-Phone (Android) based electrocardiogram (ECG) acquisition and monitoring system (cvrPhone), and an application to estimate RA, in real-time. In in-vivo swine studies (N = 17), 12-lead ECG signals were recorded at baseline and following coronary artery occlusion. RA was estimated using the Fast Fourier Transform (FFT) method using a custom developed algorithm in JAVA. Underlying ischemia was detected using a custom developed ischemic index. RA from each lead showed a significant (p < 0.05) increase within 1 min of occlusion compared to baseline (n = 29). Following myocardial infarction, spontaneous ventricular tachycardia episodes (n = 4) were preceded by significant (p < 0.05) increase of RA prior to the onset of the tachy-arrhythmias. Similarly, the ischemic index exhibited a significant increase following myocardial infarction (p < 0.05) and preceding a tachy-arrhythmic event. In conclusion, RA can be effectively estimated using surface lead electrocardiograms by analyzing beat-to-beat variability in ECG morphology using a smartphone based platform. cvrPhone can be used to detect myocardial ischemia and arrhythmia susceptibility using a user-friendly, clinically acceptable, mobile platform.
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Arritmias Cardíacas/diagnóstico , Morte Súbita Cardíaca/patologia , Monitorização Fisiológica , Smartphone , Algoritmos , Animais , Arritmias Cardíacas/fisiopatologia , Morte Súbita Cardíaca/prevenção & controle , Modelos Animais de Doenças , Eletrocardiografia , Ventrículos do Coração/fisiopatologia , Humanos , Infarto do Miocárdio/diagnóstico , Infarto do Miocárdio/fisiopatologia , Suínos , Taquicardia VentricularRESUMO
BACKGROUND: Sleep disordered breathing manifested as sleep apnea (SA) is prevalent in the general population, and while it is associated with increased morbidity and mortality risk in some patient populations, it remains under-diagnosed. The objective of this study was to assess the accuracy of respiration-rate (RR) and tidal-volume (TV) estimation algorithms, from body-surface ECG signals, using a smartphone based ambulatory respiration monitoring system (cvrPhone). METHODS: Twelve lead ECG signals were collected using the cvrPhone from anesthetized and mechanically ventilated swine (n = 9). During ECG data acquisition, the mechanical ventilator tidal-volume (TV) was varied from 250 to 0 to 750 to 0 to 500 to 0 to 750 ml at respiratory rates (RR) of 6 and 14 breaths/min, respectively, and the RR and TV values were estimated from the ECG signals using custom algorithms. RESULTS: TV estimations from any two different TV settings showed statistically significant difference (p < 0.01) regardless of the RR. RRs were estimated to be 6.1±1.1 and 14.0±0.2 breaths/min at 6 and 14 breaths/min, respectively (when 250, 500 and 750 ml TV settings were combined). During apnea, the estimated TV and RR values were 11.7±54.9 ml and 0.0±3.5 breaths/min, which were significantly different (p<0.05) than TV and RR values during non-apnea breathing. In addition, the time delay from the apnea onset to the first apnea detection was 8.6±6.7 and 7.0±3.2 seconds for TV and RR respectively. CONCLUSIONS: We have demonstrated that apnea can reliably be detected using ECG-derived RR and TV algorithms. These results support the concept that our algorithms can be utilized to detect SA in conjunction with ECG monitoring.
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Eletrocardiografia , Monitorização Fisiológica/instrumentação , Síndromes da Apneia do Sono/diagnóstico , Síndromes da Apneia do Sono/fisiopatologia , Smartphone , Animais , Masculino , Taxa Respiratória , Processamento de Sinais Assistido por Computador , Suínos , Volume de Ventilação PulmonarRESUMO
OBJECTIVE: To investigate associations between takeaway meal consumption and risk markers for coronary heart disease, type 2 diabetes and obesity risk markers in children. DESIGN: A cross-sectional, school-based observational study. SETTING: 85 primary schools across London, Birmingham and Leicester. PARTICIPANTS: 1948 UK primary school children in year 5, aged 9-10 years. MAIN OUTCOME MEASURES: Children reported their frequency of takeaway meal consumption, completed a 24-hour dietary recall, had physical measurements and provided a fasting blood sample. RESULTS: Among 1948 participants with complete data, 499 (26%) never/hardly ever consumed a takeaway meal, 894 (46%) did so <1/week and 555 (28%) did ≥1/week. In models adjusted for age, sex, month, school, ethnicity and socioeconomic status, more frequent takeaway meal consumption was associated with higher dietary intakes of energy, fat % energy and saturated fat % energy and higher energy density (all P trend <0.001) and lower starch, protein and micronutrient intakes (all P trend <0.05). A higher frequency of takeaway meal consumption was associated with higher serum total cholesterol and low-density lipoprotein (LDL) cholesterol (P trend=0.04, 0.01, respectively); children eating a takeaway meal ≥1/week had total cholesterol and LDL cholesterol 0.09 mmol/L (95% CI 0.01 to 0.18) and 0.10 mmol/L (95% CI 0.02 to 0.18) higher respectively than children never/hardly ever eating a takeaway meal; their fat mass index was also higher. CONCLUSIONS: More frequent takeaway meal consumption in children was associated with unhealthy dietary nutrient intake patterns and potentially with adverse longer term consequences for obesity and coronary heart disease risk.
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Doença das Coronárias/etiologia , Diabetes Mellitus Tipo 2/etiologia , Fast Foods/efeitos adversos , Obesidade Infantil/etiologia , Glicemia/análise , Criança , Estudos Transversais , Inquéritos sobre Dietas , Ingestão de Energia/fisiologia , Inglaterra , Fast Foods/estatística & dados numéricos , Comportamento Alimentar , Feminino , Humanos , Lipídeos/sangue , Masculino , Estado Nutricional , Exame Físico , Fatores de Risco , Classe SocialRESUMO
From 1998 to 2003 in San Francisco, unprotected anal intercourse (UAI) with one or more partner of unknown HIV serostatus (potentially serodiscordant UAI) increased among bisexual men who have sex with men (MSM) in parallel and in magnitude compared with other MSM. Potentially serodiscordant UAI and unprotected vaginal intercourse increased from 1998 to 2001 then decreased from 2001 to 2003. Although elements of a 'bisexual bridge' are present, we note an encouraging decrease in risk from 2001 to 2003.
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Bissexualidade/estatística & dados numéricos , Soroprevalência de HIV/tendências , Sexo Seguro , Estudos Transversais , Feminino , Soropositividade para HIV , Humanos , Modelos Logísticos , Masculino , Assunção de Riscos , São Francisco/epidemiologia , Parceiros SexuaisRESUMO
BACKGROUND AND PURPOSE: Our purpose was to determine whether cerebral perfusion functional CT (fCT), performed after endovascular middle cerebral artery (MCA) occlusion, can be used to predict final cerebral infarction extent in a primate model. METHODS: fCT with bolus tracking was performed before and 30 and 150 minutes after 3-hour digital subtraction angiography (DSA)-guided endovascular MCA occlusion in five baboons. Parametric cerebral blood flow (CBF), cerebral blood volume (CBV) and mean transit time (MTT) maps were constructed by voxel-by-voxel gamma variate fitting and used to determine lesion sizes. Animals were sacrificed 48 hours after the occlusion, and ex vivo MR imaging was performed. Lesion sizes on fCT and MR images were compared. RESULTS: Hypoperfusion was clearly identified on all images obtained after MCA occlusion. Thirty and 150 minutes after occlusion onset, respectively, mean lesion sizes were 737 mm(2) +/- 33 and 737 mm(2) +/- 44 for CBF, 722 mm(2) +/- 32 and 730 mm(2) +/- 43 for CBV, and 819 mm(2) +/- 14 and 847 mm(2) +/- 11 for MTT. Mean outcome infarct size on MR images was 733 mm(2) +/- 30. Measurements based on CBV and CBF (R(2) = 0.97 and 0.96, P <.001), but not MTT (R(2) = 0.40, P >.5), were highly correlated with final lesion size. CONCLUSION: An endovascular approach to MCA occlusion provides a minimally invasive, reproducible animal model for controlled studies of cerebral ischemia and infarction. Derived cerebral perfusion maps closely predict the 48-hour infarct size after 3-hour MCA occlusion.
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Arteriopatias Oclusivas/complicações , Arteriopatias Oclusivas/diagnóstico por imagem , Artérias Cerebrais , Infarto Cerebral/etiologia , Tomografia Computadorizada por Raios X , Angiografia Digital , Animais , Arteriopatias Oclusivas/diagnóstico , Arteriopatias Oclusivas/fisiopatologia , Volume Sanguíneo , Isquemia Encefálica/etiologia , Angiografia Cerebral , Circulação Cerebrovascular , Modelos Animais de Doenças , Previsões , Imageamento por Ressonância Magnética , Papio , Acidente Vascular Cerebral/etiologia , Fatores de TempoRESUMO
This article describes and tests a photography rig that has been built at the University of Melbourne, Australia, specifically for the purpose of taking rapid and highly standardized craniofacial photographs, in simultaneous views of front and profile. The rig uses a novel projected light range-finding system that has been designed for easy and accurate positioning of subjects, in the natural head position, at precise distances from the frontal camera. Results of experiments examining the intraobserver error of multiple photographs taken on the rig indicate that high-quality, repeatable photographs can be taken after a reasonably large amount of time has lapsed between photography sessions (e.g., 30 days). This study also indicates that some variability remains between photographs even when highly standardized protocols are followed. Consequently, it is expected that the variation between photographs with limited standardization is much larger and more likely to cause significant errors in any comparisons.
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Face , Fotografação/métodos , Fotografação/normas , Crânio , Desenho de Equipamento , Humanos , Fotografação/instrumentaçãoRESUMO
BACKGROUND: T-wave alternans (TWA) has been implicated in the pathogenesis of ventricular arrhythmias and sudden cardiac death. However, to estimate and suppress TWA effectively, the phase of TWA must be accurately determined. METHODS AND RESULTS: We developed a method that computes the beat-by-beat integral of the T-wave morphology, over time points within the T-wave with positive alternans. Then, we estimated the signed derivative of the T-wave integral sequence, which allows the classification of each beat to a binary phase index. In animal studies, we found that this method was able to accurately identify the T-wave phase in artificially induced alternans (P<0.0001). The coherence of the phase increased consistently after acute ischemia induction in all body-surface and intracardiac leads (P<0.0001). Also, we developed a phase-resetting detection algorithm that enhances the diagnostic utility of TWA. We further established an algorithm that uses the phase of TWA to deliver appropriate polarity-pacing pulses (all interventions compared with baseline, P<0.0001 for alternans voltage; P<0.0001 for K(score)), to suppress TWA. Finally, we demonstrated that using the phase of TWA we can suppress spontaneous TWA during acute ischemia; 77.6% for alternans voltage (P<0.0001) and 92.5% for K(score) (P<0.0001). CONCLUSIONS: We developed a method to quantify the temporal variability of the TWA phase. This method is expected to enhance the utility of TWA in predicting ventricular arrhythmias and sudden cardiac death and raises the possibility of using upstream therapies to abort a ventricular tachyarrhythmia before its onset.
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Arritmias Cardíacas/diagnóstico , Técnicas Eletrofisiológicas Cardíacas , Sistema de Condução Cardíaco/fisiopatologia , Processamento de Sinais Assistido por Computador , Potenciais de Ação , Algoritmos , Animais , Arritmias Cardíacas/etiologia , Arritmias Cardíacas/fisiopatologia , Estimulação Cardíaca Artificial , Modelos Animais de Doenças , Eletrocardiografia , Masculino , Isquemia Miocárdica/complicações , Isquemia Miocárdica/fisiopatologia , Valor Preditivo dos Testes , Suínos , Fatores de TempoRESUMO
PURPOSE: We describe the profile and associations of anisometropia and aniso-astigmatism in a population-based sample of children. METHODS: The Northern Ireland Childhood Errors of Refraction (NICER) study used a stratified random cluster design to recruit a representative sample of children from schools in Northern Ireland. Examinations included cycloplegic (1% cyclopentolate) autorefraction, and measures of axial length, anterior chamber depth, and corneal curvature. χ(2) tests were used to assess variations in the prevalence of anisometropia and aniso-astigmatism by age group, with logistic regression used to compare odds of anisometropia and aniso-astigmatism with refractive status (myopia, emmetropia, hyperopia). The Mann-Whitney U test was used to examine interocular differences in ocular biometry. RESULTS: Data from 661 white children aged 12 to 13 years (50.5% male) and 389 white children aged 6 to 7 years (49.6% male) are presented. The prevalence of anisometropia ≥1 diopters sphere (DS) did not differ statistically significantly between 6- to 7-year-old (8.5%; 95% confidence interval [CI], 3.9-13.1) and 12- to 13-year-old (9.4%; 95% CI, 5.9-12.9) children. The prevalence of aniso-astigmatism ≥1 diopters cylinder (DC) did not vary statistically significantly between 6- to 7-year-old (7.7%; 95% CI, 4.3-11.2) and 12- to 13-year-old (5.6%; 95% CI, 0.5-8.1) children. Anisometropia and aniso-astigmatism were more common in 12- to 13-year-old children with hyperopia ≥+2 DS. Anisometropic eyes had greater axial length asymmetry than nonanisometropic eyes. Aniso-astigmatic eyes were more asymmetric in axial length and corneal astigmatism than eyes without aniso-astigmatism. CONCLUSIONS: In this population, there is a high prevalence of axial anisometropia and corneal/axial aniso-astigmatism, associated with hyperopia, but whether these relations are causal is unclear. Further work is required to clarify the developmental mechanism behind these associations.
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Anisometropia/epidemiologia , Astigmatismo/epidemiologia , Erros de Refração/epidemiologia , Adolescente , Distribuição por Idade , Comprimento Axial do Olho/anatomia & histologia , Biometria , Criança , Ciclopentolato/administração & dosagem , Feminino , Humanos , Masculino , Midriáticos/administração & dosagem , Irlanda do Norte/epidemiologia , Prevalência , Pupila/efeitos dos fármacos , Visão Binocular/fisiologia , População Branca/etnologiaRESUMO
Multifrequency (0 to 0.3 mm(-1)), multiwavelength (633, 680, 720, 800, and 820 nm) spatial frequency domain imaging (SFDI) of 5-aminolevulinic acid-induced protoporphyrin IX (PpIX) was used to recover absorption, scattering, and fluorescence properties of glioblastoma multiforme spheroids in tissue-simulating phantoms and in vivo in a mouse model. Three-dimensional tomographic reconstructions of the frequency-dependent remitted light localized the depths of the spheroids within 500 µm, and the total amount of PpIX in the reconstructed images was constant to within 30% when spheroid depth was varied. In vivo tumor-to-normal contrast was greater than â¼1.5 in reduced scattering coefficient for all wavelengths and was â¼1.3 for the tissue concentration of deoxyhemoglobin (ctHb). The study demonstrates the feasibility of SFDI for providing enhanced image guidance during surgical resection of brain tumors.
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Neoplasias Encefálicas/patologia , Neoplasias Encefálicas/cirurgia , Glioma/patologia , Glioma/cirurgia , Microscopia de Fluorescência/métodos , Protoporfirinas , Cirurgia Assistida por Computador/métodos , Animais , Linhagem Celular Tumoral , Meios de Contraste , Camundongos , Camundongos Nus , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Tomografia Óptica/métodosRESUMO
BACKGROUND: The objective of this study was to examine adiposity patterns in UK South Asian, black African-Caribbean and white European children using a range of adiposity markers. A cross-sectional survey in London, Birmingham and Leicester primary schools was conducted. Weight, height, waist circumference, skinfold thickness values (biceps, triceps, subscapular and suprailiac) were measured. Fat mass was derived from bioimpedance; optimally height-standardized indices were derived for all adiposity markers. Ethnic origin was based on parental self-report. Multilevel models were used to obtain adjusted means and ethnic differences adjusted for gender, age, month, observer and school (fitted as a random effect). A total of 5887 children aged 9-10 years participated (response rate 68%), including 1345 white Europeans, 1523 South Asians and 1570 black African-Caribbeans. RESULTS: Compared with white Europeans, South Asians had a higher sum of all skinfolds and fat mass percentage, and their body mass index (BMI) was lower. South Asians were slightly shorter but use of optimally height-standardized indices did not materially affect these comparisons. At any given fat mass, BMI was lower in South Asians than white Europeans. In similar comparisons, black African-Caribbeans had a lower sum of all skinfolds but a higher fat mass percentage, and their BMI was higher. Black African-Caribbeans were markedly taller. Use of optimally height-standardized indices yielded markedly different findings; sum of skinfolds index was markedly lower, whereas fat mass index and weight-for-height index were similar. At any given fat mass, BMI was similar in black African-Caribbeans and white Europeans. CONCLUSIONS: UK South Asian children have higher adiposity levels and black African-Caribbeans have similar or lower adiposity levels when compared with white Europeans. However, these differences are not well represented by comparisons based on BMI, which systematically underestimates adiposity in South Asians, and in black African-Caribbeans it overestimates adiposity because of its association with height.
Assuntos
Adiposidade , Tamanho Corporal , África/etnologia , Antropometria , Ásia/etnologia , Biomarcadores/análise , Estatura , Peso Corporal , Região do Caribe/etnologia , Criança , Estudos Transversais , Impedância Elétrica , Europa (Continente)/etnologia , Feminino , Humanos , Modelos Lineares , Masculino , Dobras Cutâneas , Reino Unido/epidemiologia , População BrancaRESUMO
Raman micro-spectroscopy combined with multivariate analysis was employed to monitor real-time biochemical changes induced in living cells in vitro following exposure to a pharmaceutical. The cancer drug etoposide (topoisomerase II inhibitor) was used to induce double-strand DNA breaks in human type II pneumocyte-like cells (A549 cell-line). Raman spectra of A549 cells exposed to 100 microM etoposide were collected and classical least squares (CLS) analysis used to determine the relative concentrations of the main cellular components. It was found that the concentrations of DNA and RNA significantly (P < 0.05) decreased, whilst the concentration of lipids significantly (P < 0.05) increased with increasing etoposide exposure time as compared to control untreated A549 cells. The concentration of DNA decreased by 27.5 and 87.0% after 24 and 48 h exposure to etoposide respectively. Principal components analysis (PCA) successfully discriminated between treated and untreated cells, with the main variance between treatment groups attributed to changes in DNA and lipid. DNA fragmentation was confirmed by Western blot analysis of apoptosis regulator protein p53 and cell metabolic activity determined by MTT assay. The over-expression of p53 protein in the etoposide treated cells indicated a significant level of DNA fragmentation and apoptosis. MTT tests confirmed that cellular metabolic activity decreased following exposure to etoposide by 29.4 and 61.2% after 24 and 48 h, respectively. Raman micro-spectroscopy may find applications in the toxicology screening of other drugs, chemicals and new biomaterials, with a range of cell types.
Assuntos
Análise Espectral Raman/métodos , Testes de Toxicidade/métodos , Apoptose/efeitos dos fármacos , Linhagem Celular , Dano ao DNA , Fragmentação do DNA/efeitos dos fármacos , Etoposídeo/toxicidade , Humanos , Modelos Teóricos , Proteína Supressora de Tumor p53/efeitos dos fármacos , Proteína Supressora de Tumor p53/metabolismoRESUMO
This review summarises progress in Raman spectroscopy and its application in diagnostics, toxicological testing and tissue engineering. Applications of Raman spectroscopy in cell biology are in the early stages of development, however, recent publications have demonstrated its utilisation as a diagnostic and development tool with the key advantage that investigations of living cells can be performed non-invasively.Some of the research highlighted here demonstrates the ability of Raman spectroscopy to accurately characterise cancer cells and distinguish between similar cell types. Many groups have used Raman spectroscopy to study tissues, but recently increased effort has gone into single cell analysis of cell lines; the advantages being that cell lines offer ease of handling and increased reproducibility over tissue studies and primary cells. The main goals of bio-Raman spectroscopy at this stage are twofold. Firstly, the aim is to further develop the diagnostic ability of Raman spectroscopy so it can be implemented in a clinical environment, producing accurate and rapid diagnoses. Secondly, the aim is to optimise the technique as a research tool for the non-invasive real time investigation of cell/material interactions in the fields of tissue engineering and toxicology testing.