Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 350
Filtrar
1.
J Prev Alzheimers Dis ; 11(4): 881-888, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-39044497

RESUMEN

BACKGROUND: Stronger resting-state functional connectivity of the default mode and frontoparietal control networks has been associated with cognitive resilience to Alzheimer's disease related pathology and neurodegeneration in smaller cohort studies. OBJECTIVES: We investigated whether these networks are associated with longitudinal CR to AD biomarkers of beta-amyloid (Aß). DESIGN: Longitudinal mixed. SETTING: The Anti-Amyloid Treatment in Asymptomatic Alzheimer's Disease (A4) study and its natural history observation arm, the Longitudinal Evaluation of Amyloid Risk and Neurodegeneration (LEARN) study. PARTICIPANTS: A sample of 1,021 cognitively unimpaired older adults (mean age = 71.2 years [SD = 4.7 years], 61% women, 42% APOEε4 carriers, 52% Aß positive). MEASUREMENTS: Global cognitive performance (Preclinical Alzheimer's Cognitive Composite) was assessed over an average 5.4 year follow-up period (SD = 2 years). Cortical Aß and functional connectivity (left and right frontoparietal control and default mode networks) were estimated from fMRI and PET, respectively, at baseline. Covariates included baseline age, APOEε4 carrier status, years of education, adjusted gray matter volume, head motion, study group, cumulative treatment exposure, and cognitive test version. RESULTS: Mixed effects models revealed that functional connectivity of the left frontoparietal control network moderated the negative effect of Aß on cognitive change (p = .025) such that stronger connectivity was associated with reduced Aß-related cognitive decline. CONCLUSIONS: Our results demonstrate a potential protective effect of functional connectivity in preclinical AD, such that stronger connectivity in this network is associated with slower Aß-related cognitive decline.


Asunto(s)
Enfermedad de Alzheimer , Péptidos beta-Amiloides , Disfunción Cognitiva , Lóbulo Frontal , Imagen por Resonancia Magnética , Lóbulo Parietal , Humanos , Femenino , Masculino , Anciano , Péptidos beta-Amiloides/metabolismo , Lóbulo Parietal/diagnóstico por imagen , Estudios Longitudinales , Lóbulo Frontal/diagnóstico por imagen , Tomografía de Emisión de Positrones , Síntomas Prodrómicos , Red Nerviosa/diagnóstico por imagen , Red Nerviosa/fisiopatología
2.
Artículo en Inglés | MEDLINE | ID: mdl-38796100

RESUMEN

BACKGROUND: Oral food challenge (OFC) is the criterion standard for diagnosis of acute food protein-induced enterocolitis syndrome (FPIES). No diagnostic/prognostic biomarkers are available, and OFC assessment criteria are not validated. OBJECTIVE: To assess clinical-hematological changes and predictors of severity of FPIES reactions at OFC. METHODS: This was an observational multicenter prospective study. Children aged 0 to 18 years diagnosed with acute FPIES were recruited at follow-up OFC in 12 tertiary centers in Spain and Italy. OFC outcomes (as positive/negative/inconclusive and mild/moderate/severe) were assessed on the basis of published "2017 FPIES Consensus" criteria. Clinical characteristics were recorded, and full blood cell count was done at baseline, reaction onset, and 4 hours later. Regression analysis was performed to assess predictors of severe reactions at OFC. RESULTS: A total of 81 children had positive OFC (mild in 11% [9 of 81], moderate in 61% [49 of 81], and severe in 28% [23 of 81]). Increase in neutrophils and reduction in eosinophils, basophils, and lymphocytes were observed (P < .05). OFC was inconclusive in 19 cases despite objective signs or neutrophilia. Regression analysis showed that a 2-day OFC protocol where only 25% of an age-appropriate portion is given on day 1 (not sex, age, culprit food, cumulative dose, and previous reaction severity) was associated with reduced odds of severe reaction compared with giving multiple doses in a single day. CONCLUSIONS: Distinct hematological changes may help support FPIES diagnosis. Current OFC assessment criteria may not capture the broad spectrum of acute FPIES presentations. This 2-day protocol may be associated with a reduced risk of severe reactions. Future work should aim to develop safer OFC and non-OFC diagnostics for FPIES.

3.
J Nutr Health Aging ; 27(12): 1174-1187, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-38151868

RESUMEN

BACKGROUND AND OBJECTIVE: It is documented that low protein and amino-acid dietary intake is related to poorer cognitive health and increased risk of dementia. Degradation of the neuromodulatory pathways, (comprising the cholinergic, dopaminergic, serotoninergic and noradrenergic systems) is observed in neurodegenerative diseases and impairs the proper biosynthesis of key neuromodulators from micro-nutrients and amino acids. How these micro-nutrients are linked to neuromodulatory pathways in healthy adults is less studied. The Locus Coeruleus-Noradrenergic System (LC-NA) is the earliest subcortical structure affected in Alzheimer's disease, showing marked neurodegeneration, but is also sensitive for age-related changes. The LC-NA system is critical for supporting attention and cognitive control, functions that are enhanced both by tyrosine administration and chronic tyrosine intake. The purpose of this study was to 1) investigate whether the dietary intake of tyrosine, the key precursor for noradrenaline (NA), is related to LC signal intensity 2) whether LC mediates the reported association between tyrosine intake and higher cognitive performance (measured with Trail Making Test - TMT), and 3) whether LC signal intensity relates to an objective measure of brain maintenance (BrainPAD). METHODS: The analyses included 398 3T MRIs of healthy participants from the Berlin Aging Study II to investigate the relationship between LC signal intensity and habitual dietary tyrosine intake-daily average (HD-Tyr-IDA - measured with Food Frequency Questionnaire - FFQ). As a control procedure, the same analyses were repeated on other main seeds of the neuromodulators' subcortical system (Dorsal and Medial Raphe, Ventral Tegmental Area and Nucleus Basalis of Meynert). In the same way, the relationships between the five nuclei and BrainPAD were tested. RESULTS: Results show that HD-Tyr-IDA is positively associated with LC signal intensity. Similarly, LC disproportionally relates to better brain maintenance (BrainPAD). Mediation analyses reveal that only LC, relative to the other nuclei tested, mediates the relationship between HD-Tyr-IDA I and performance in the TMT and between HD-Tyr-IDA and BrainPAD. CONCLUSIONS: These findings provide the first evidence linking tyrosine intake with LC-NA system signal intensity and its correlation with neuropsychological performance. This study strengthens the role of diet for maintaining brain and cognitive health and supports the noradrenergic theory of cognitive reserve. Within this framework, adequate tyrosine intake might increase the resilience of LC-NA system functioning, by preventing degeneration and supporting noradrenergic metabolism required for LC function and neuropsychological performance.


Asunto(s)
Locus Coeruleus , Tirosina , Humanos , Locus Coeruleus/metabolismo , Tirosina/metabolismo , Sustancia Gris/diagnóstico por imagen , Envejecimiento , Norepinefrina/metabolismo , Imagen por Resonancia Magnética , Atención , Dieta , Ingestión de Alimentos , Neurotransmisores/metabolismo
5.
Alzheimers Res Ther ; 13(1): 128, 2021 07 12.
Artículo en Inglés | MEDLINE | ID: mdl-34253231

RESUMEN

BACKGROUND: Cognitive reserve is most commonly measured using socio-behavioural proxy variables. These variables are easy to collect, have a straightforward interpretation, and are widely associated with reduced risk of dementia and cognitive decline in epidemiological studies. However, the specific proxies vary across studies and have rarely been assessed in complete models of cognitive reserve (i.e. alongside both a measure of cognitive outcome and a measure of brain structure). Complete models can test independent associations between proxies and cognitive function in addition to the moderation effect of proxies on the brain-cognition relationship. Consequently, there is insufficient empirical evidence guiding the choice of proxy measures of cognitive reserve and poor comparability across studies. METHOD: In a cross-sectional study, we assessed the validity of 5 common proxies (education, occupational complexity, verbal intelligence, leisure activities, and exercise) and all possible combinations of these proxies in 2 separate community-dwelling older adult cohorts: The Irish Longitudinal Study on Ageing (TILDA; N = 313, mean age = 68.9 years, range = 54-88) and the Cognitive Reserve/Reference Ability Neural Network Study (CR/RANN; N = 234, mean age = 64.49 years, range = 50-80). Fifteen models were created with 3 brain structure variables (grey matter volume, hippocampal volume, and mean cortical thickness) and 5 cognitive variables (verbal fluency, processing speed, executive function, episodic memory, and global cognition). RESULTS: No moderation effects were observed. There were robust positive associations with cognitive function, independent of brain structure, for 2 individual proxies (verbal intelligence and education) and 16 composites (i.e. combinations of proxies). Verbal intelligence was statistically significant in all models. Education was significant only in models with executive function as the cognitive outcome variable. Three robust composites were observed in more than two-thirds of brain-cognition models: the composites of (1) occupational complexity and verbal intelligence, (2) education and verbal intelligence, and (3) education, occupational complexity, and verbal intelligence. However, no composite had larger average effects nor was more robust than verbal intelligence alone. CONCLUSION: These results support the use of verbal intelligence as a proxy measure of CR in cross-sectional studies of cognitively healthy older adults.


Asunto(s)
Reserva Cognitiva , Anciano , Anciano de 80 o más Años , Cognición , Estudios Transversales , Escolaridad , Humanos , Inteligencia , Estudios Longitudinales , Persona de Mediana Edad , Pruebas Neuropsicológicas
6.
JPEN J Parenter Enteral Nutr ; 45(6): 1369-1375, 2021 08.
Artículo en Inglés | MEDLINE | ID: mdl-33586170

RESUMEN

BACKGROUND: The direct effect of the coronavirus disease 2019 (COVID-19) pandemic on patients with intestinal failure (IF) has not been described. METHODS: We conducted a nationwide study of UK IF centers to evaluate the infection rates, presentations, and outcomes in patients with types 2 and 3 IF. RESULTS: A total of 45 patients with IF contracted COVID-19 between March and August 2020; this included 26 of 2191 (1.2%) home parenteral nutrition (HPN)-dependent adults and 19 of 298 (6.4%) adults hospitalized with type 2 IF. The proportion of patients receiving nursing care for HPN administration was higher in those with community-acquired COVID-19 (66.7%) than the proportion in the entire HPN cohort (26.1%; P < .01). Two HPN-dependent and 1 hospitalized patient with type 2 IF died as a direct consequence of the virus (6.7% of 45 patients with types 2 or 3 infected). CONCLUSION: This is the first study to describe the outcomes of COVID-19 in a large cohort of patients requiring long-term PN. Methods to reduce hospital and community nosocomial spread would likely be beneficial.


Asunto(s)
COVID-19 , Enfermedades Intestinales , Nutrición Parenteral en el Domicilio , Adulto , Humanos , Enfermedades Intestinales/complicaciones , Enfermedades Intestinales/terapia , Nutrición Parenteral en el Domicilio/efectos adversos , Estudios Retrospectivos , SARS-CoV-2 , Reino Unido/epidemiología
7.
Clin Exp Allergy ; 50(12): 1302-1312, 2020 12.
Artículo en Inglés | MEDLINE | ID: mdl-33283366

RESUMEN

In the second of two linked articles, we describe the development in clinical as described by Clinical & Experimental Allergy and other journals in 2019. Epidemiology, clinical allergy, asthma and rhinitis are all covered. In this article, we described the development in the field of allergy as described by Clinical and Experimental Allergy in 2019. Epidemiology, clinical allergy, asthma and rhinitis are all covered.


Asunto(s)
Alérgenos/inmunología , Hipersensibilidad/inmunología , Sistema Inmunológico/inmunología , Animales , Asma/epidemiología , Asma/inmunología , Asma/metabolismo , Asma/terapia , Hipersensibilidad a los Alimentos/epidemiología , Hipersensibilidad a los Alimentos/inmunología , Hipersensibilidad a los Alimentos/metabolismo , Hipersensibilidad a los Alimentos/terapia , Humanos , Hipersensibilidad/epidemiología , Hipersensibilidad/metabolismo , Hipersensibilidad/terapia , Sistema Inmunológico/metabolismo , Pronóstico , Rinitis Alérgica/epidemiología , Rinitis Alérgica/inmunología , Rinitis Alérgica/metabolismo , Rinitis Alérgica/terapia , Factores de Riesgo
8.
Clin Exp Allergy ; 50(12): 1294-1301, 2020 12.
Artículo en Inglés | MEDLINE | ID: mdl-33283368

RESUMEN

In the first of two linked articles, we describe the development in the mechanisms underlying allergy as described by Clinical & Experimental Allergy and other journals in 2019. Experimental models of allergic disease, basic mechanisms, clinical mechanisms and allergens are all covered.


Asunto(s)
Alérgenos/inmunología , Hipersensibilidad/inmunología , Sistema Inmunológico/inmunología , Animales , Modelos Animales de Enfermedad , Humanos , Hipersensibilidad/metabolismo , Sistema Inmunológico/metabolismo
9.
Prev Chronic Dis ; 17: E107, 2020 09 17.
Artículo en Inglés | MEDLINE | ID: mdl-32945768

RESUMEN

INTRODUCTION: Reducing tobacco-related health disparities has been a public health priority for more than 2 decades, yet disparities in cigarette use have remained steady or worsened. Less is known about how disparities in other tobacco products have changed over time. Our study examined trends in cigarette and other tobacco product use in Minnesota with the goal of informing efforts aimed at reducing disparities. METHODS: We examined tobacco use disparities as a function of education, income, and race across the Minnesota Adult Tobacco Survey results in 2010 (N = 7,057), 2014 (N = 9,304), and 2018 (N = 6,055). Tobacco use was captured by assessing past 30-day use of 4 tobacco products: cigarettes, cigars, e-cigarettes, and smokeless tobacco, plus combustibles (ie, cigarettes and/or cigars) and any tobacco (ie, use of any of the 4 products). RESULTS: At each wave, those with lower income and education reported greater use of cigarettes, combustibles, and any tobacco than those with higher income and education. Black respondents were more likely to report cigar and combustibles use than White respondents in 2018, whereas White respondents were more likely to report smokeless tobacco use in 2014. We saw no significant wave-by-demographic interactions, suggesting that the magnitude of the disparity remained unchanged over time for any tobacco product. CONCLUSION: Substantial disparities in tobacco use remain across education, income, and race, even in a state such as Minnesota with a strong tobacco control program. Additional efforts are needed to close disparity gaps and reach endgame tobacco use targets for all subpopulations.


Asunto(s)
Fumar Tabaco/tendencias , Tabaco sin Humo/estadística & datos numéricos , Vapeo/tendencias , Estudios Transversales , Recolección de Datos , Humanos
10.
Sci Rep ; 10(1): 6549, 2020 04 16.
Artículo en Inglés | MEDLINE | ID: mdl-32300235

RESUMEN

Many aspects of the supposed hyperthermal Toarcian Oceanic Anoxic Event (T-OAE, Early Jurassic, c. 182 Ma) are well understood but a lack of robust palaeotemperature data severely limits reconstruction of the processes that drove the T-OAE and associated environmental and biotic changes. New oxygen isotope data from calcite shells of the benthic fauna suggest that bottom water temperatures in the western Tethys were elevated by c. 3.5 °C through the entire T-OAE. Modelling supports the idea that widespread marine anoxia was induced by a greenhouse-driven weathering pulse, and is compatible with the OAE duration being extended by limitation of the global silicate weathering flux. In the western Tethys Ocean, the later part of the T-OAE is characterized by abundant occurrences of the brachiopod Soaresirhynchia, which exhibits characteristics of slow-growing, deep sea brachiopods. The unlikely success of Soaresirhynchia in a hyperthermal event is attributed here to low metabolic rate, which put it at an advantage over other species from shallow epicontinental environments with higher metabolic demand.


Asunto(s)
Adaptación Fisiológica , Hipoxia/fisiopatología , Invertebrados/fisiología , Océanos y Mares , Temperatura , Animales , Ciclo del Carbono , Isótopos de Carbono , Geografía , Invertebrados/ultraestructura , Modelos Teóricos , Isótopos de Oxígeno , Paleontología
11.
Neuroimage ; 215: 116795, 2020 07 15.
Artículo en Inglés | MEDLINE | ID: mdl-32278090

RESUMEN

Alzheimer's disease (AD) is the leading cause of dementia, accounting for 70% of cases worldwide. By 2050, dementia prevalence will have tripled, with most new cases occurring in low- and middle-income countries. Mild cognitive impairment (MCI) is a stage between healthy aging and dementia, marked by cognitive deficits that do not impair daily living. People with MCI are at increased risk of dementia, with an average progression rate of 39% within 5 years. There is urgent need for low-cost, accessible and objective methods to facilitate early dementia detection. Electroencephalography (EEG) has potential to address this need due to its low cost and portability. Here, we collected resting state EEG, structural MRI (sMRI) and rich neuropsychological data from older adults (55+ years) with AD, amnestic MCI (aMCI) and healthy controls (~60 per group). We evaluated a range of candidate EEG markers (i.e., frequency band power and functional connectivity) for AD and aMCI classification and compared their performance with sMRI. We also tested a combined EEG and cognitive classification model (using Mini-Mental State Examination; MMSE). sMRI outperformed resting state EEG at classifying AD (AUCs â€‹= â€‹1.00 vs 0.76, respectively). However, both EEG and sMRI were only moderately good at distinguishing aMCI from healthy aging (AUCs â€‹= â€‹0.67-0.73), and neither method achieved sensitivity above 70%. The addition of EEG to MMSE scores had no added benefit relative to MMSE scores alone. This is the first direct comparison of EEG and sMRI for classification of AD and aMCI.


Asunto(s)
Enfermedad de Alzheimer/diagnóstico , Disfunción Cognitiva/diagnóstico , Electroencefalografía , Imagen por Resonancia Magnética , Anciano , Enfermedad de Alzheimer/patología , Enfermedad de Alzheimer/fisiopatología , Disfunción Cognitiva/patología , Disfunción Cognitiva/fisiopatología , Femenino , Humanos , Aprendizaje Automático , Masculino , Pruebas Neuropsicológicas , Sensibilidad y Especificidad
12.
Clin Exp Allergy ; 49(12): 1550-1557, 2019 12.
Artículo en Inglés | MEDLINE | ID: mdl-31833123

RESUMEN

In this article, we describe developments in the field of clinical allergy as described by Clinical and Experimental Allergy in 2018; epidemiology, asthma and rhinitis, clinical allergy and allergens are all covered.


Asunto(s)
Alérgenos/inmunología , Asma/inmunología , Rinitis/inmunología , Animales , Asma/patología , Humanos , Rinitis/patología
14.
Clin Exp Allergy ; 48(12): 1606-1621, 2018 12.
Artículo en Inglés | MEDLINE | ID: mdl-30489681

RESUMEN

In this article, we described the development in the field of allergy as described by Clinical and Experimental Allergy in 2017. Experimental models of allergic disease, basic mechanisms, clinical mechanisms, allergens, asthma and rhinitis and clinical allergy are all covered.


Asunto(s)
Estudios Clínicos como Asunto , Hipersensibilidad/epidemiología , Investigación , Alérgenos/inmunología , Animales , Manejo de la Enfermedad , Susceptibilidad a Enfermedades , Historia del Siglo XXI , Humanos , Hipersensibilidad/diagnóstico , Hipersensibilidad/etiología , Hipersensibilidad/historia , Fenotipo , Investigación/tendencias , Factores de Riesgo
15.
Pediatr Blood Cancer ; 65(12): e27298, 2018 12.
Artículo en Inglés | MEDLINE | ID: mdl-30094928

RESUMEN

BACKGROUND: English-speaking Caribbean (ESC) childhood cancer outcomes are unknown. PROCEDURE: Through the SickKids-Caribbean Initiative (SCI), we established a multicenter childhood cancer database across seven centers in six ESC countries. Data managers entered patient demographics, disease, treatment, and outcome data. Data collection commenced in 2013, with retrospective collection to 2011 and subsequent prospective collection. RESULTS: A total of 367 children were diagnosed between 2011 and 2015 with a median age of 5.7 years (interquartile range 2.9-10.6 years). One hundred thirty (35.4%) patients were diagnosed with leukemia, 30 (8.2%) with lymphoma, and 149 (40.6%) with solid tumors. A relative paucity of children with brain tumors was seen (N = 58, 15.8%). Two-year event-free survival (EFS) for the cohort was 48.5% ± 3.2%; 2-year overall survival (OS) was 55.1% ± 3.1%. Children with acute lymphoblastic leukemia (ALL) and Wilms tumor (WT) experienced better 2-year EFS (62.1% ± 6.4% and 66.7% ± 10.1%), while dismal outcomes were seen in children with acute myeloid leukemia (AML; 22.7 ± 9.6%), rhabdomyosarcoma (21.0% ± 17.0%), and medulloblastoma (21.4% ± 17.8%). Of 108 deaths with known cause, 58 (53.7%) were attributed to disease and 50 (46.3%) to treatment complications. Death within 60 days of diagnosis was relatively common in acute leukemia [13/98 (13.3%) ALL, 8/26 (30.8%) AML]. Despite this, traditional prognosticators adversely impacted outcome in ALL, including higher age, higher white blood cell count, and T-cell lineage. CONCLUSIONS: ESC childhood cancer outcomes are significantly inferior to high-income country outcomes. Based on these data, interventions for improving supportive care and modifying treatment protocols are under way. Continued data collection will allow evaluation of interventions and ensure maximal outcome improvements.


Asunto(s)
Neoplasias/mortalidad , Neoplasias/terapia , Factores de Edad , Región del Caribe/epidemiología , Niño , Preescolar , Supervivencia sin Enfermedad , Femenino , Humanos , Recuento de Leucocitos , Masculino , Neoplasias/sangre , Estudios Retrospectivos , Tasa de Supervivencia , Factores de Tiempo
16.
Clin Oncol (R Coll Radiol) ; 30(9): 589-592, 2018 09.
Artículo en Inglés | MEDLINE | ID: mdl-29803344

RESUMEN

AIM: To determine the outcome after radiation therapy for desmoid fibromatosis. MATERIALS AND METHODS: A retrospective review of 50 patients treated between 1988 and 2016 in a specialised bone and soft tissue tumour clinic. RESULTS: The median age at the time of radiation therapy was 36.8 years (range 15.1-69.0) and the median follow-up time was 51 months. Forty-three patients underwent radiation therapy as the definitive treatment with a median dose of 56 Gy (range 30-58.8 Gy). The median dose for the seven patients treated with postoperative radiation therapy was 50.4 Gy (range 48-56 Gy). Eleven patients (22%) developed progressive disease after radiation therapy at a median time of 41 months (range 12-113 months). The recurrences were within the radiation therapy field in four patients and outside the field in seven patients. One patient developed a radiation-induced malignancy 20 years after treatment. CONCLUSIONS: Radiation therapy is an alternative treatment in the management of desmoid fibromatosis. It should be considered in patients for whom surgical resection is not feasible, or as adjuvant therapy after surgery with involved margins where any further recurrences would cause significant morbidity.


Asunto(s)
Fibromatosis Agresiva/radioterapia , Recurrencia Local de Neoplasia , Neoplasias Inducidas por Radiación/etiología , Neoplasias Primarias Secundarias/etiología , Neoplasias de los Tejidos Blandos/radioterapia , Adolescente , Adulto , Anciano , Progresión de la Enfermedad , Femenino , Fibromatosis Agresiva/patología , Fibromatosis Agresiva/cirugía , Humanos , Masculino , Persona de Mediana Edad , Recurrencia Local de Neoplasia/diagnóstico , Dosificación Radioterapéutica , Radioterapia Adyuvante , Estudios Retrospectivos , Neoplasias de los Tejidos Blandos/patología , Neoplasias de los Tejidos Blandos/cirugía , Adulto Joven
17.
Geobiology ; 16(3): 252-278, 2018 05.
Artículo en Inglés | MEDLINE | ID: mdl-29498810

RESUMEN

Mixing of sediments by moving animals becomes apparent in the trace fossil record from about 550 million years ago (Ma), loosely overlapping with the tail end of the extreme carbonate carbon isotope δ13 Ccarbonate fluctuations that qualitatively distinguish the Proterozoic geochemical record from that of the Phanerozoic. These Precambrian-scale fluctuations in δ13 Ccarbonate (PSF-δ13 Ccarbonate ) remain enigmatic, due to their high amplitude and inclusion of global-scale negative δ13 Ccarbonate values, below anything attributable to mantle input. Here, we note that different biogeochemical-model scenarios plausibly explaining globally synchronous PSF-δ13 Ccarbonate converge: via mechanistic requirements for extensive anoxia in marine sediments to support sedimentary build-up of 13 C-depleted carbon. We hypothesize that bioturbation qualitatively reduced marine sediment anoxia by exposing sediments to oxygenated overlying waters, which ultimately contributed to decreasing the carbon cycle's subsequent susceptibility to PSF- δ13 Ccarbonate . Bioturbation may also have reduced the quantity of (isotopically light) organic-derived carbon available to contribute to PSF- δ13 Ccarbonate via ocean crust carbonatization at depth. We conduct a comparative modelling exercise in which we introduce bioturbation to existing model scenarios for PSF- δ13 Ccarbonate : expressing both the anoxic proportion of marine sediments, and the global organic carbon burial efficiency, as a decreasing function of bioturbation. We find that bioturbation's oxygenating impact on sediments has the capacity to prevent PSF- δ13 Ccarbonate caused by authigenic carbonate precipitation or methanogenesis. Bioturbation's impact on the f-ratio via remineralization is partially offset by liberation of organic phosphate, some of which feeds back into new production. We emphasize that this study is semiquantitative, exploratory and intended merely to provide a qualitative theoretical framework within which bioturbation's impact on long-term, first-order δ13 Ccarbonate can be assessed (and it is hoped quantified in more detail by future work). With this proviso, we conclude that it is entirely plausible that bioturbation made a decisive contribution to the enigmatic directionality in the δ13 Ccarbonate record, from the Neoproterozoic-Cambrian boundary onwards.


Asunto(s)
Isótopos de Carbono/análisis , Fósiles , Sedimentos Geológicos/química , Anaerobiosis , Ciclo del Carbono , Simulación por Computador , Metabolismo
18.
Clin Exp Allergy ; 48(8): 1000-1015, 2018 08.
Artículo en Inglés | MEDLINE | ID: mdl-29570230

RESUMEN

INTRODUCTION: Eczema is a common childhood ailment responsible for a considerable disease burden. Both timing of introduction to solid food and allergenic food are believed to be related to childhood eczema. Despite the growing body of evidence, the relationship between timing of any solid food introduction (allergenic and/or non-allergenic) and development of eczema has not previously been systematically reviewed. METHODS: PubMed and EMBASE databases were searched using food and eczema terms. Two authors selected papers according to the inclusion criteria and extracted information on study characteristics and measures of association. Meta-analyses were performed after grouping studies according to the age and type of exposure. RESULTS: A total of 17 papers met the inclusion criteria, reporting results from 16 study populations. Of these, 11 were cohort studies, 2 case-controls, 1 cross-sectional study and 2 randomized controlled trials. Limited meta-analyses were performed due to heterogeneity between studies. Timing of solid food introduction was not associated with eczema. One randomized controlled trial provided weak evidence of an association between early allergenic (around 4 months) food introduction and reduced risk of eczema. CONCLUSIONS: The available evidence is currently insufficient to determine whether the timing of introduction of any solid food influences the risk of eczema.


Asunto(s)
Susceptibilidad a Enfermedades , Eccema/epidemiología , Eccema/etiología , Alimentos Infantiles , Alérgenos/inmunología , Estudios de Casos y Controles , Estudios Transversales , Humanos , Ensayos Clínicos Controlados Aleatorios como Asunto , Factores de Tiempo
19.
Allergol Immunopathol (Madr) ; 46(4): 389-393, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-29338964

RESUMEN

BACKGROUND: Obstructive respiratory disorders, such as allergic rhinitis and asthma may impair sleep quality. The aim of this study is to validate the Children's Sleep Habits Questionnaire (CSHQ) for Greek children from 6 to 14 years of age. No validated tool has been developed so far to assess sleep disturbances in Greek school-aged children. METHODS: We examined the reliability and validity of the CSHQ in a sample of children with allergic rhinitis (AR) and a non-clinical population of parents of these children as a proxy measure of children's AR quality of life (QoL) as evaluated by the Pediatric Allergic Rhinitis Quality of Life (PedARQoL) questionnaire. RESULTS: The CSHQ questionnaire Child's Form (CF) had a moderate internal consistency with a Cronbach's alpha 0.671 and Guttman split-half coefficient of 0.563 when correlated with the PedARQoL (CF). There was also a moderate intraclass correlation of ICC=0.505 between the responses to both questionnaires in the two visits. The CSHQ Parent's Form (PF) had a very good internal consistency with a Cronbach's alpha of 0.928 and Guttman split-half coefficient of 0.798. There was a high intraclass correlation of 0.643 between the responses in the two visits. CONCLUSIONS: The Greek version of the CSHQ CF, but particularly the PF has proved to be a very reliable clinical instrument, which can be used in clinical trials for assessing sleep quality in school-aged children with sleep disturbances because of obstructive airway disorders, such as AR.


Asunto(s)
Calidad de Vida , Rinitis Alérgica/complicaciones , Sueño , Encuestas y Cuestionarios , Adolescente , Niño , Femenino , Grecia , Humanos , Masculino , Psicometría
20.
J Perinatol ; 38(1): 80-85, 2018 01.
Artículo en Inglés | MEDLINE | ID: mdl-29095433

RESUMEN

OBJECTIVE: To determine short-term outcomes of infants with evidence of hypoxia-ischemia at birth and classified as mild neonatal encephalopathy (NE) at <6 h of age. STUDY DESIGN: Prospective multicenter study. Mild NE was defined as ⩾1 abnormal category in modified Sarnat score. Primary outcome was any abnormality on early amplitude integrated electroencephalogram (aEEG) or seizures, abnormal brain magnetic resonance imaging (MRI) or neurological exam at discharge. RESULTS: A total of 54/63 (86%) of enrolled infants had data on components of the primary outcome, which was abnormal in 28/54 (52%): discontinuous aEEG (n=4), MRI (n=9) and discharge exam (n=22). Abnormal tone and/or incomplete Moro were the most common findings. MRI abnormalities were confined to cerebral cortex but two infants had basal ganglia and/or thalamus involvement. The 18 to 24 months follow-up is ongoing. CONCLUSIONS: A larger than expected proportion of mild NE infants with abnormal outcomes was observed. Future research should evaluate safety and efficacy of neuroprotection for mild NE.


Asunto(s)
Encéfalo/patología , Electroencefalografía , Hipoxia-Isquemia Encefálica/diagnóstico , Convulsiones/etiología , Canadá , Femenino , Humanos , Hipotermia Inducida/métodos , Recién Nacido , Imagen por Resonancia Magnética , Masculino , Examen Neurológico , Valor Predictivo de las Pruebas , Estudios Prospectivos , Convulsiones/diagnóstico , Índice de Severidad de la Enfermedad
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...