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1.
BMC Pulm Med ; 24(1): 232, 2024 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-38745268

RESUMO

BACKGROUND: Excessive use of short-acting ß2 agonists (SABA) in patients with asthma continues to be a notable concern due to its link to higher mortality rates. Global relevance of SABA overuse in asthma management cannot be understated, it poses significant health risk to patients with asthma and imposes burden on healthcare systems. This study, as part of global SABINA progamme, aimed to describe the prescribing patterns and clinical outcomes associated with SABA use in the Chinese population. METHODS: Retrospective cohort study was conducted using anonymized electronic healthcare records of Clinical Data Analysis and Reporting System (CDARS) from Hong Kong Hospital Authority (HA). Patients newly diagnosed with asthma between 2011 and 2018 and aged ≥12 years were included, stratified by SABA use (≤2, 3-6, 7-10, or ≥11 canisters/year) during one-year baseline period since asthma diagnosis date. Patients were followed up from one-year post-index until earliest censoring of events: outcome occurrence and end of study period (31 December 2020). Cox proportional regression and negative binomial regression were used to estimate the mortality risk and frequency of hospital admissions associated with SABA use respectively, after adjusting for age, sex, Charlson Comorbidity Index (CCI), and inhaled corticosteroid (ICS) dose. Outcomes include all-cause, asthma-related, and respiratory-related mortality, frequency of hospital admissions for any cause, and frequency of hospital admissions due to asthma. RESULTS: 17,782 patients with asthma (mean age 46.7 years, 40.8% male) were included and 59.1% of patients were overusing SABA (≥ 3 canisters per year). Each patient was prescribed a median of 5.61 SABA canisters/year. SABA overuse during baseline period was associated with higher all-cause mortality risk compared to patients with ≤2 canisters/year. Association was dose-dependent, highest risk in those used ≥11 canisters/year (adjusted hazard ratio: 1.42, 95% CI: 1.13, 1.79) and 3-6 canisters/year (adjusted hazard ratio: 1.22, 95% CI: 1.00, 1.50). Higher SABA prescription volume associated with increased frequency of hospital admissions with greatest risk observed in 7-10 canisters/year subgroup (adjusted rate ratio: 4.81, 95% CI: 3.66, 6.37). CONCLUSIONS: SABA overuse is prevalent and is associated with increased all-cause mortality risk and frequency of hospital admissions among the patients with asthma in Hong Kong.


Assuntos
Agonistas de Receptores Adrenérgicos beta 2 , Asma , Humanos , Hong Kong/epidemiologia , Masculino , Feminino , Asma/tratamento farmacológico , Estudos Retrospectivos , Pessoa de Meia-Idade , Adulto , Agonistas de Receptores Adrenérgicos beta 2/uso terapêutico , Agonistas de Receptores Adrenérgicos beta 2/administração & dosagem , Padrões de Prática Médica/estatística & dados numéricos , Padrões de Prática Médica/tendências , Idoso , Adulto Jovem , Adolescente , Hospitalização/estatística & dados numéricos , População do Leste Asiático
2.
Phys Rev Lett ; 130(12): 126401, 2023 Mar 24.
Artigo em Inglês | MEDLINE | ID: mdl-37027842

RESUMO

The recently discovered layered kagome metals of composition AV_{3}Sb_{5} (A=K, Rb, Cs) exhibit a complex interplay among superconductivity, charge density wave order, topologically nontrivial electronic band structure and geometrical frustration. Here, we probe the electronic band structure underlying these exotic correlated electronic states in CsV_{3}Sb_{5} with quantum oscillation measurements in pulsed fields up to 86 T. The high-field data reveal a sequence of magnetic breakdown orbits that allows the construction of a model for the folded Fermi surface of CsV_{3}Sb_{5}. The dominant features are large triangular Fermi surface sheets that cover almost half the folded Brillouin zone. These sheets have not yet been detected in angle resolved photoemission spectroscopy and display pronounced nesting. The Berry phases of the electron orbits have been deduced from Landau level fan diagrams near the quantum limit without the need for extrapolations, thereby unambiguously establishing the nontrivial topological character of several electron bands in this kagome lattice superconductor.

3.
Cochrane Database Syst Rev ; 8: CD011677, 2022 08 29.
Artigo em Inglês | MEDLINE | ID: mdl-36036664

RESUMO

BACKGROUND: Several school-based interventions are effective in improving child diet and physical activity, and preventing excessive weight gain, and tobacco or harmful alcohol use. However, schools are frequently unsuccessful in implementing such evidence-based interventions. OBJECTIVES: 1. To evaluate the benefits and harms of strategies aiming to improve school implementation of interventions to address student diet, physical activity, tobacco or alcohol use, and obesity. 2. To evaluate the benefits and harms of strategies to improve intervention implementation on measures of student diet, physical activity, obesity, tobacco use or alcohol use; describe their cost or cost-effectiveness; and any harms of strategies on schools, school staff or students. SEARCH METHODS: We used standard, extensive Cochrane search methods. The latest search was between 1 September 2016 and 30 April 2021 to identify any relevant trials published since the last published review. SELECTION CRITERIA: We defined 'Implementation' as the use of strategies to adopt and integrate evidence-based health interventions and to change practice patterns within specific settings. We included any trial (randomised controlled trial (RCT) or non-randomised controlled trial (non-RCT)) conducted at any scale, with a parallel control group that compared a strategy to implement policies or practices to address diet, physical activity, overweight or obesity, tobacco or alcohol use by students to 'no intervention', 'usual' practice or a different implementation strategy. DATA COLLECTION AND ANALYSIS: We used standard Cochrane methods. Given the large number of outcomes reported, we selected and included the effects of a single outcome measure for each trial for the primary (implementation) and secondary (student health behaviour and obesity) outcomes using a decision hierarchy. Where possible, we calculated standardised mean differences (SMDs) to account for variable outcome measures with 95% confidence intervals (CI). For RCTs, we conducted meta-analyses of primary and secondary outcomes using a random-effects model, or in instances where there were between two and five studies, a fixed-effect model. The synthesis of the effects for non-randomised studies followed the 'Synthesis without meta-analysis' (SWiM) guidelines. MAIN RESULTS: We included an additional 11 trials in this update bringing the total number of included studies in the review to 38. Of these, 22 were conducted in the USA. Twenty-six studies used RCT designs. Seventeen trials tested strategies to implement healthy eating, 12 physical activity and six a combination of risk factors. Just one trial sought to increase the implementation of interventions to delay initiation or reduce the consumption of alcohol. All trials used multiple implementation strategies, the most common being educational materials, educational outreach and educational meetings. The overall certainty of evidence was low and ranged from very low to moderate for secondary review outcomes. Pooled analyses of RCTs found, relative to a control, the use of implementation strategies may result in a large increase in the implementation of interventions in schools (SMD 1.04, 95% CI 0.74 to 1.34; 22 RCTs, 1917 participants; low-certainty evidence). For secondary outcomes we found, relative to control, the use of implementation strategies to support intervention implementation may result in a slight improvement on measures of student diet (SMD 0.08, 95% CI 0.02 to 0.15; 11 RCTs, 16,649 participants; low-certainty evidence) and physical activity (SMD 0.09, 95% CI -0.02 to 0.19; 9 RCTs, 16,389 participants; low-certainty evidence). The effects on obesity probably suggest little to no difference (SMD -0.02, 95% CI -0.05 to 0.02; 8 RCTs, 18,618 participants; moderate-certainty evidence). The effects on tobacco use are very uncertain (SMD -0.03, 95% CIs -0.23 to 0.18; 3 RCTs, 3635 participants; very low-certainty evidence). One RCT assessed measures of student alcohol use and found strategies to support implementation may result in a slight increase in use (odds ratio 1.10, 95% CI 0.77 to 1.56; P = 0.60; 2105 participants). Few trials reported the economic evaluations of implementation strategies, the methods of which were heterogeneous and evidence graded as very uncertain. A lack of consistent terminology describing implementation strategies was an important limitation of the review. AUTHORS' CONCLUSIONS: The use of implementation strategies may result in large increases in implementation of interventions, and slight improvements in measures of student diet, and physical activity. Further research is required to assess the impact of implementation strategies on such behavioural- and obesity-related outcomes, including on measures of alcohol use, where the findings of one trial suggest it may slightly increase student risk. Given the low certainty of the available evidence for most measures further research is required to guide efforts to facilitate the translation of evidence into practice in this setting.


Assuntos
Dieta , Nicotiana , Criança , Exercício Físico , Humanos , Obesidade/prevenção & controle , Políticas , Ensaios Clínicos Controlados Aleatórios como Assunto , Uso de Tabaco
4.
Br J Surg ; 108(11): 1315-1322, 2021 11 11.
Artigo em Inglês | MEDLINE | ID: mdl-34467970

RESUMO

BACKGROUND: There is a lack of information regarding the provision of parental leave for surgical careers. This survey study aims to evaluate the experience of maternity/paternity leave and views on work-life balance globally. METHODS: A 55-item online survey in 24 languages was distributed via social media as per CHERRIES guideline from February to March 2020. It explored parental leave entitlements, attitude towards leave taking, financial impact, time spent with children and compatibility of parenthood with surgical career. RESULTS: Of the 1393 (male : female, 514 : 829) respondents from 65 countries, there were 479 medical students, 349 surgical trainees and 513 consultants. Consultants had less than the recommended duration of maternity leave (43.8 versus 29.1 per cent), no paid maternity (8.3 versus 3.2 per cent) or paternity leave (19.3 versus 11.0 per cent) compared with trainees. Females were less likely to have children than males (36.8 versus 45.6 per cent, P = 0.010) and were more often told surgery is incompatible with parenthood (80.2 versus 59.5 per cent, P < 0.001). Males spent less than 20 per cent of their salary on childcare and fewer than 30 hours/week with their children. More than half (59.2 per cent) of medical students did not believe a surgical career allowed work-life balance. CONCLUSION: Surgeons across the globe had inadequate parental leave. Significant gender disparity was seen in multiple aspects.


Assuntos
Escolha da Profissão , Internato e Residência/estatística & dados numéricos , Licença Parental/estatística & dados numéricos , Estudantes de Medicina/estatística & dados numéricos , Cirurgiões/estatística & dados numéricos , Inquéritos e Questionários , Adulto , Atitude do Pessoal de Saúde , Feminino , Humanos , Masculino , Fatores Sexuais , Adulto Jovem
5.
Phys Rev Lett ; 126(15): 157001, 2021 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-33929261

RESUMO

In this Letter, we describe quantitative magnetic imaging of superconducting vortices in RbEuFe_{4}As_{4} in order to investigate the unique interplay between the magnetic and superconducting sublattices. Our scanning Hall microscopy data reveal a pronounced suppression of the superfluid density near the magnetic ordering temperature in good qualitative agreement with a recently developed model describing the suppression of superconductivity by correlated magnetic fluctuations. These results indicate a pronounced exchange interaction between the superconducting and magnetic subsystems in RbEuFe_{4}As_{4}, with important implications for future investigations of physical phenomena arising from the interplay between them.

6.
Hong Kong Med J ; 26(6): 479-485, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33284132

RESUMO

OBJECTIVES: To investigate the effects of pre-hospital stroke screening and notification on reperfusion therapy for patients with acute ischaemic stroke. METHODS: Pre-hospital stroke screening criteria were established based on a modified version of the Face Arm Speech Time (FAST) test. Screening was performed during ambulance transport by emergency medical service (EMS) personnel who completed a 2-hour training session on stroke screening. Temporal trends affecting acute ischaemic stroke investigation and intervention were compared before and after implementation of the pre-hospital screening. RESULTS: From July 2018 to October 2019, 298 patients with suspected stroke were screened by EMS personnel during ambulance transport prior to hospital arrival. Of these 298 patients, 213 fulfilled the screening criteria, 166 were diagnosed with acute stroke, and 32 received reperfusion therapy. The onset-to-door time was shortened by more than 1.5 hours (100.6 min vs 197.6 min, P<0.001). The door-to-computed tomography time (25.6 min vs 32.0 min, P=0.021), door-to-needle time (49.2 min vs 70.1 min, P=0.003), and door-to-groin puncture time for intra-arterial mechanical thrombectomy (126.7 min vs 168.6 min, P=0.04) were significantly shortened after implementation of the pre-hospital screening and notification, compared with historical control data of patients admitted from January 2018 to June 2018, before implementation of the screening system. CONCLUSION: Implementation of pre-hospital stroke screening using criteria based on a modified version of the FAST test, together with pre-arrival notification, significantly shortened the door-to-reperfusion therapy time for patients with ischaemic stroke. Pre-hospital stroke screening during ambulance transport by EMS personnel who complete a 2-hour focused training session is effective for identifying reperfusion-eligible patients with stroke.


Assuntos
Programas de Triagem Diagnóstica , Serviços Médicos de Emergência/métodos , AVC Isquêmico/diagnóstico , Reperfusão/estatística & dados numéricos , Tempo para o Tratamento/estatística & dados numéricos , Idoso , Idoso de 80 Anos ou mais , Diagnóstico Precoce , Auxiliares de Emergência/educação , Feminino , Implementação de Plano de Saúde , Humanos , AVC Isquêmico/terapia , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Estudos Retrospectivos
7.
Clin Exp Allergy ; 46(6): 871-83, 2016 06.
Artigo em Inglês | MEDLINE | ID: mdl-27129138

RESUMO

BACKGROUND: Allergies to cashew are increasing in prevalence, with clinical symptoms ranging from oral pruritus to fatal anaphylactic reaction. Yet, cashew-specific T cell epitopes and T cell cross-reactivity amongst cashew and other tree nut allergens in humans remain uncharacterized. OBJECTIVES: In this study, we characterized cashew-specific T cell responses in cashew-allergic subjects and examined cross-reactivity of these cashew-specific cells towards other tree nut allergens. METHODS: CD154 up-regulation assay was used to determine immunodominance hierarchy among cashew major allergens at the T cell level. The phenotype, magnitude and functionality of cashew-specific T cells were determined by utilizing ex vivo staining with MHC class II tetramers. Dual tetramer staining and proliferation experiments were used to determine cross-reactivity to other tree nuts. RESULTS: CD4(+) T cell responses were directed towards cashew allergens Ana o 1 and Ana o 2. Multiple Ana o 1 and Ana o 2 T cell epitopes were then identified. These epitopes elicited either TH 2 or TH 2/TH 17 responses in allergic subjects, which were either cashew unique epitope or cross-reactive epitopes. For clones that recognized the cross-reactive epitope, T cell clones responded robustly to cashew, hazelnut and/or pistachio but not to walnut. CONCLUSIONS: Phylogenetically diverse tree nut allergens can activate cashew-reactive T cells and elicit a TH 2-type response at an epitope-specific level. CLINICAL RELEVANCE: Lack of cross-reactivity between walnut and cashew suggests that cashew peptide immunotherapy approach may not be most effective for walnut.


Assuntos
Alérgenos/imunologia , Antígenos de Plantas/imunologia , Linfócitos T CD4-Positivos/imunologia , Reações Cruzadas/imunologia , Epitopos de Linfócito T/imunologia , Nozes/efeitos adversos , Proteínas de Plantas/imunologia , Adolescente , Adulto , Sequência de Aminoácidos , Basófilos/imunologia , Basófilos/metabolismo , Linfócitos T CD4-Positivos/metabolismo , Criança , Mapeamento de Epitopos , Epitopos de Linfócito T/química , Feminino , Cadeias HLA-DRB1/genética , Cadeias HLA-DRB1/imunologia , Humanos , Imunoglobulina E/imunologia , Masculino , Hipersensibilidade a Noz/diagnóstico , Hipersensibilidade a Noz/genética , Hipersensibilidade a Noz/imunologia , Hipersensibilidade a Noz/metabolismo , Testes Cutâneos , Subpopulações de Linfócitos T/imunologia , Subpopulações de Linfócitos T/metabolismo , Adulto Jovem
8.
Clin Exp Allergy ; 46(5): 705-19, 2016 05.
Artigo em Inglês | MEDLINE | ID: mdl-26662458

RESUMO

BACKGROUND: Timothy grass (TG) pollen is a common seasonal airborne allergen associated with symptoms ranging from mild rhinitis to severe asthma. OBJECTIVE: The aim of this study was to characterize changes in TG-specific T cell responses as a function of seasonality. METHODS: Peripheral blood mononuclear cells (PBMCs) obtained from allergic individuals and non-allergic controls, either during the pollen season or out of season, were stimulated with either TG extract or a pool of previously identified immunodominant antigenic regions. RESULTS: PBMCs from allergic subjects exhibit higher IL-5 and IL-10 responses in season than when collected out of season. In the case of non-allergic subjects, as expected we observed lower IL-5 responses and robust production of IFN-γ compared to allergic individuals. Strikingly, non-allergic donors exhibited an opposing pattern, with decreased immune reactivity in season. The broad down-regulation in non-allergic donors indicates that healthy individuals are not oblivious to allergen exposure, but rather react with an active modulation of responses following the antigenic stimulus provided during the pollen season. Transcriptomic analysis of allergen-specific T cells defined genes modulated in concomitance with the allergen exposure and inhibition of responses in non-allergic donors. CONCLUSION AND CLINICAL RELEVANCE: Magnitude and functionality of T helper cell responses differ substantially in season vs. out of season in allergic and non-allergic subjects. The results indicate the specific and opposing modulation of immune responses following the antigenic stimulation during the pollen season. This seasonal modulation reflects the enactment of specific molecular programmes associated with health and allergic disease.


Assuntos
Alérgenos/imunologia , Imunomodulação , Fenótipo , Phleum/imunologia , Pólen/imunologia , Rinite Alérgica Sazonal/diagnóstico , Rinite Alérgica Sazonal/imunologia , Estudos de Casos e Controles , Citocinas/metabolismo , Feminino , Perfilação da Expressão Gênica , Regulação da Expressão Gênica , Antígenos HLA/genética , Antígenos HLA/imunologia , Humanos , Memória Imunológica , Leucócitos Mononucleares/imunologia , Leucócitos Mononucleares/metabolismo , Ativação Linfocitária , Contagem de Linfócitos , Masculino , RNA Mensageiro/genética , Rinite Alérgica Sazonal/genética , Rinite Alérgica Sazonal/metabolismo , Estações do Ano , Especificidade do Receptor de Antígeno de Linfócitos T , Subpopulações de Linfócitos T/imunologia , Subpopulações de Linfócitos T/metabolismo , Transcriptoma
9.
Neurobiol Dis ; 83: 26-34, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26321676

RESUMO

Individuals with Rett syndrome have greatly impaired speech and language abilities. Auditory brainstem responses to sounds are normal, but cortical responses are highly abnormal. In this study, we used the novel rat Mecp2 knockout model of Rett syndrome to document the neural and behavioral processing of speech sounds. We hypothesized that both speech discrimination ability and the neural response to speech sounds would be impaired in Mecp2 rats. We expected that extensive speech training would improve speech discrimination ability and the cortical response to speech sounds. Our results reveal that speech responses across all four auditory cortex fields of Mecp2 rats were hyperexcitable, responded slower, and were less able to follow rapidly presented sounds. While Mecp2 rats could accurately perform consonant and vowel discrimination tasks in quiet, they were significantly impaired at speech sound discrimination in background noise. Extensive speech training improved discrimination ability. Training shifted cortical responses in both Mecp2 and control rats to favor the onset of speech sounds. While training increased the response to low frequency sounds in control rats, the opposite occurred in Mecp2 rats. Although neural coding and plasticity are abnormal in the rat model of Rett syndrome, extensive therapy appears to be effective. These findings may help to explain some aspects of communication deficits in Rett syndrome and suggest that extensive rehabilitation therapy might prove beneficial.


Assuntos
Córtex Auditivo/fisiopatologia , Percepção Auditiva/fisiologia , Neurônios/fisiologia , Fonética , Síndrome de Rett/fisiopatologia , Estimulação Acústica , Animais , Discriminação Psicológica/fisiologia , Modelos Animais de Doenças , Potenciais Evocados Auditivos , Feminino , Técnicas de Inativação de Genes , Proteína 2 de Ligação a Metil-CpG/genética , Ruído , Ratos , Ratos Sprague-Dawley , Síndrome de Rett/genética
10.
Phys Rev Lett ; 115(4): 046602, 2015 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-26252701

RESUMO

Extremely large magnetoresistance (XMR) was recently discovered in WTe_{2}, triggering extensive research on this material regarding the XMR origin. Since WTe_{2} is a layered compound with metal layers sandwiched between adjacent insulating chalcogenide layers, this material has been considered to be electronically two-dimensional (2D). Here we report two new findings on WTe_{2}: (1) WTe_{2} is electronically 3D with a mass anisotropy as low as 2, as revealed by the 3D scaling behavior of the resistance R(H,θ)=R(ϵ_{θ}H) with ϵ_{θ}=(cos^{2}θ+γ^{-2}sin^{2}θ)^{1/2}, θ being the magnetic field angle with respect to the c axis of the crystal and γ being the mass anisotropy and (2) the mass anisotropy γ varies with temperature and follows the magnetoresistance behavior of the Fermi liquid state. Our results not only provide a general scaling approach for the anisotropic magnetoresistance but also are crucial for correctly understanding the electronic properties of WTe_{2}, including the origin of the remarkable "turn-on" behavior in the resistance versus temperature curve, which has been widely observed in many materials and assumed to be a metal-insulator transition.

11.
Scand J Rheumatol ; 44(1): 70-3, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25179456

RESUMO

OBJECTIVES: To investigate whether all-cause mortality and deaths due to cardiovascular disease are increased in patients who have consulted primary or secondary health care with symptoms and signs of osteoarthritis (OA). METHOD: This study included 383 patients with symptomatic OA at multiple sites from the Genetics ARthrosis and Progression (GARP) study (mean age 60 years, 82% women, 3693 person-years of follow-up) and 459 patients with primary hand, knee, or hip OA from the Osteoarthritis Care Clinic (OCC) study (mean age 61 years, 88% women, 1890 person-years of follow-up). Standardized mortality ratios (SMRs) with 95% confidence intervals (CIs) were calculated for all-cause mortality and causes of deaths in comparison to the general population. Cox proportional hazard ratios (HRs) with 95% CIs were used to associate baseline characteristics with all-cause mortality. RESULTS: In the GARP study, 26 patients died whereas 48 deaths were expected (SMR 0.54, 95% CI 0.37-0.79). The SMR was 0.47 (95% CI 0.29-0.76) in women and 0.73 (95% CI 0.39-1.35) in men. Similar results were found in the OCC study (SMR 0.45, 95% CI 0.25-0.82). Malignancy and cardiovascular disease were the main causes of deaths in GARP. Male sex (HR 3.04, 95% CI 1.38-6.69), increasing age (HR 1.10, 95% CI 1.05-1.16), and self-reported cancer (HR 8.29, 95% CI 3.12-22.03) were associated with increased mortality in GARP. CONCLUSIONS: Patients consulting health care for their OA are not at higher risk of death than the general population. These results suggest that the management of OA patients may not need to focus specifically on the treatment of cardiovascular risk factors and comorbidities.


Assuntos
Doenças Cardiovasculares/mortalidade , Osteoartrite do Quadril/mortalidade , Osteoartrite do Joelho/mortalidade , Idoso , Intervalos de Confiança , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Modelos de Riscos Proporcionais , Estudos Prospectivos , Fatores de Risco , Irmãos
12.
BMC Bioinformatics ; 15 Suppl 2: S8, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24564837

RESUMO

BACKGROUND: Under a Markov model of evolution, recoding, or lumping, of the four nucleotides into fewer groups may permit analysis under simpler conditions but may unfortunately yield misleading results unless the evolutionary process of the recoded groups remains Markovian. If a Markov process is lumpable, then the evolutionary process of the recoded groups is Markovian. RESULTS: We consider stationary, reversible, and homogeneous Markov processes on two taxa and compare three tests for lumpability: one using an ad hoc test statistic, which is based on an index that is evaluated using a bootstrap approximation of its distribution; one that is based on a test proposed specifically for Markov chains; and one using a likelihood-ratio test. We show that the likelihood-ratio test is more powerful than the index test, which is more powerful than that based on the Markov chain test statistic. We also show that for stationary processes on binary trees with more than two taxa, the tests can be applied to all pairs. Finally, we show that if the process is lumpable, then estimates obtained under the recoded model agree with estimates obtained under the original model, whereas, if the process is not lumpable, then these estimates can differ substantially. We apply the new likelihood-ratio test for lumpability to two primate data sets, one with a mitochondrial origin and one with a nuclear origin. CONCLUSIONS: Recoding may result in biased phylogenetic estimates because the original evolutionary process is not lumpable. Accordingly, testing for lumpability should be done prior to phylogenetic analysis of recoded data.


Assuntos
Filogenia , Análise de Sequência de DNA/métodos , Animais , DNA Mitocondrial/química , Funções Verossimilhança , Cadeias de Markov , Nucleotídeos/análise , Primatas , Homologia de Sequência do Ácido Nucleico
13.
Clin Exp Allergy ; 44(7): 986-98, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24708411

RESUMO

BACKGROUND: Conceptually, allergic responses may involve cross-reactivity by antibodies or T-cells. While IgE cross-reactivity among grass-pollen allergens has been observed, cross-reactivity at the allergen-specific T-cell level has been less documented. Identification of the patterns of cross-reactivity may improve our understanding, allowing optimization of better immunotherapy strategies. OBJECTIVES: We use Phleum pratense as model for the studying of cross-reactivity at the allergen-specific CD4(+) T cell level among DR04:01 restricted Pooideae grass-pollen T-cell epitopes. METHODS: After in vitro culture of blood mono-nucleated cells from grass-pollen-allergic subjects with specific Pooideae antigenic epitopes, dual tetramer staining with APC-labelled DR04:01/Phleum pratense tetramers and PE-labelled DR04:01/Pooideae grass homolog tetramers was assessed to identify cross-reactivity among allergen-specific DR04:01-restricted T-cells in six subjects. Direct ex vivo staining enabled the comparison of frequency and phenotype of different Pooideae grass-pollen reactive T-cells. Intracellular cytokine staining (ICS) assays were also used to examine phenotypes of these T-cells. RESULTS: T-cells with various degrees of cross-reactive profiles could be detected. Poa p 1 97-116 , Lol p 1 221-240 , Lol p 5a 199-218 , and Poa p 5a 199-218 were identified as minimally cross-reactive T-cell epitopes that do not show cross-reactivity to Phl p 1 and Phl p 5a epitopes. Ex vivo tetramer staining assays demonstrated T-cells that recognized these minimally cross-reactive T-cell epitopes are present in Grass-pollen-allergic subjects. CONCLUSIONS: Our results suggest that not all Pooideae grass epitopes with sequence homology are cross-reactive. Non-cross-reactive T-cells with comparable frequency, phenotype and functionality to Phl p-specific T-cells suggest that a multiple allergen system should be considered for immunotherapy instead of a mono-allergen system.


Assuntos
Alérgenos/imunologia , Linfócitos T CD4-Positivos/imunologia , Reações Cruzadas/imunologia , Dessensibilização Imunológica , Poaceae/imunologia , Subpopulações de Linfócitos T/imunologia , Alelos , Sequência de Aminoácidos , Antígenos de Plantas/química , Antígenos de Plantas/imunologia , Basófilos/imunologia , Basófilos/metabolismo , Linfócitos T CD4-Positivos/metabolismo , Citocinas/metabolismo , Epitopos de Linfócito T/química , Epitopos de Linfócito T/imunologia , Antígenos HLA/genética , Antígenos HLA/imunologia , Humanos , Imunoglobulina E/imunologia , Ativação Linfocitária/imunologia , Peptídeos/química , Peptídeos/imunologia , Pólen/imunologia , Especificidade do Receptor de Antígeno de Linfócitos T/imunologia , Subpopulações de Linfócitos T/metabolismo
14.
Osteoarthritis Cartilage ; 22(1): 40-3, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24185107

RESUMO

OBJECTIVE: To study inflammatory ultrasound (US) features and pain over a 3-month period in hand osteoarthritis (HOA). DESIGN: In 25 consecutive HOA patients (mean age 60 years, 76% female), fulfilling the American College of Rheumatology (ACR) criteria, visual analogue scale (VAS) pain scores were collected at baseline and 3 months. In 750 [all first carpometacarpal (CMC), metacarpalphalangeal (MCP), proximal interphalangeal (PIP), distal interphalangeal (DIP) and first interphalangeal (IP)] joints, pain was assessed upon palpation and synovial thickening, effusion and power Doppler signal (PDS) were scored with standardized methods by US. Associations between inflammatory features and painful joints were analysed using generalized estimated equations to account for patient effects, adjusting for confounders, and presented as odds ratios (ORs) with 95% confidence intervals (95%CI). RESULTS: Inflammatory US features were seen in (nearly) all patients. The median number (range) of inflammatory joints per patient did not change over time: 9 (0-16) to 9 (2-18). In 18.7% of joints inflammatory features were present at both time points; in 20.5% inflammatory features occurred only at baseline or follow-up. Pain decreased over time: median VAS pain 49-39 mm; median number of painful joints 8-3. Synovial thickening, effusion and PDS were associated with pain upon palpation both at baseline and follow-up: OR 2.9 (1.4, 5.7), 2.7 (1.7, 4.3), 3.6 (2.1, 6.3) and 7.3 (3.2, 16.5), 3.3 (2.3, 4.7), 4.1 (2.1, 7.9). respectively. CONCLUSIONS: In HOA inflammatory US features are stable over time at patient level, but vary on joint level. Pain diminished after 3 months, while associations between painful joints and inflammation seem to increase, emphasizing the multifactorial aetiology of pain.


Assuntos
Articulação da Mão/diagnóstico por imagem , Osteoartrite/diagnóstico por imagem , Idoso , Feminino , Seguimentos , Articulação da Mão/patologia , Humanos , Masculino , Pessoa de Meia-Idade , Osteoartrite/complicações , Osteoartrite/patologia , Dor/diagnóstico por imagem , Dor/etiologia , Medição da Dor/métodos , Radiografia , Membrana Sinovial/diagnóstico por imagem , Membrana Sinovial/patologia , Ultrassonografia Doppler/métodos
15.
Osteoarthritis Cartilage ; 22(6): 756-63, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24680934

RESUMO

OBJECTIVE: To estimate the prevalence of erosive disease in first carpometacarpal joints (CMCJs) and investigate its clinical impact compared with radiographic thumb base (TB) osteoarthritis (OA). PATIENT AND METHODS: Standardized assessments with hand radiographs were performed in participants of two population-based cohort studies in North Staffordshire with hand symptoms lasting ≥1 day in the past month. Erosive disease was defined as the presence of eroded or remodeled phase in ≥1 interphalangeal joint (IPJ) or first CMCJ following the Verbruggen-Veys classification. Hand pain and function were assessed with Australian/Canadian Hand Osteoarthritis Index (AUSCAN). Prevalence was estimated by dividing the number of persons with erosive lesions by population size. Linear and logistic regression analyses were used to contrast clinical determinants between persons with erosions and with radiographic TB OA. Results were presented as mean differences and odds ratios (ORs) with 95% confidence intervals (95% CI), adjusted for age, sex and radiographic severity. RESULTS: 1,076 participants were studied (60% women, mean age 64.7 years (SD 8.3); 24 persons had erosive disease in the TB. The prevalence of erosive disease in first CMCJs was 2.2% (95% CI 1.4, 3.3). Only 0.5% (95% CI 0.2, 1.2) had erosive disease affecting IPJs and first CMCJs combined. More persons with erosive disease of first CMCJs reported pain in their TB than persons with radiographic TB OA, AUSCAN pain and function scores were similar. CONCLUSION: Erosive disease of first CMCJs was present in 2.2% of subjects with hand pain and was often not accompanied by erosions in IPJs. Erosive disease was associated with TB pain, but not with the level of pain, when compared with radiographic TB OA.


Assuntos
Articulações Carpometacarpais/patologia , Osteoartrite/epidemiologia , Osteoartrite/patologia , Medição da Dor , Polegar/diagnóstico por imagem , Adulto , Fatores Etários , Idoso , Articulações Carpometacarpais/diagnóstico por imagem , Estudos de Casos e Controles , Estudos de Coortes , Intervalos de Confiança , Feminino , Seguimentos , Força da Mão , Humanos , Vida Independente , Masculino , Pessoa de Meia-Idade , Razão de Chances , Osteoartrite/diagnóstico por imagem , Prevalência , Estudos Prospectivos , Radiografia , Amplitude de Movimento Articular/fisiologia , Características de Residência , Medição de Risco , Fatores Sexuais , Perfil de Impacto da Doença , Polegar/patologia
16.
Phys Rev Lett ; 112(15): 157001, 2014 Apr 18.
Artigo em Inglês | MEDLINE | ID: mdl-24785065

RESUMO

We report the direct imaging of a novel modulated flux striped domain phase in a nearly twin-free YBCO crystal. These domains arise from instabilities in the vortex structure within a narrow region of tilted magnetic fields at small angles from the in-plane direction. By comparing the experimental and theoretically derived vortex phase diagrams we infer that the stripe domains emerge from a first-order phase transition of the vortex structure. The size of domains containing vortices of certain orientations is controlled by the balance between the vortex stray field energy and the positive energy of the domain boundaries. Our results confirm the existence of the kinked vortex chain phase in an anisotropic high temperature superconductor and reveal a sharp transition in the state of this phase resulting in regular vortex domains.

17.
Allergy ; 69(9): 1162-70, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24934402

RESUMO

BACKGROUND: Allergen-specific immunotherapy (SIT) faces problems related to side effects and limited efficacy. Direct administration of allergen extracts into lymph nodes induces increased specific IgG production and T-cell responses using significantly lower allergen doses. METHODS: In this study, mechanisms of immune regulation by MAT vaccines in vitro and in allergen-SIT of cat-allergic rhinitis patients, who received 3 inguinal intra-lymph node injections of MAT-Fel d 1 vaccine, were investigated in PBMC and cell cultures for specific T-cell proliferation, Fel d 1-tetramer-specific responses, and multiple immune regulatory molecules. RESULTS: MAT-Fel d 1 vaccine was efficiently internalized by antigen-presenting cells. This was followed by precaspase 1 cleavage to caspase 1 and secretion of IL-1ß, indicating inflammasome activation. Mat-Fel d 1 induced specific T-cell proliferation and an IL-10- and IFN-γ-dominated T-cell responses with decreased Th2 cytokines at 100 times lower doses than Fel d 1. Induction of immune tolerance by MAT-Fel d 1-ILIT involved multiple mechanisms of immune suppression. Early Fel d 1-specific T-cell activation was followed by full T-cell unresponsiveness to allergen after 1 year in the MAT-Fel d 1 group, characterized by increased allergen-specific T regulatory cells, decreased circulating Fel d 1 tetramer-positive cells, increased IL-10 and FOXP3 expression, and change in the HR2/HR1 ratio toward HR2. CONCLUSIONS: This study demonstrates the induction of allergen tolerance after 3 intra-lymph node injections of MAT-Fel d 1 vaccine, mediated by increased cellular internalization of the allergen, activation of inflammasome, and generation of allergen-specific peripheral T-cell tolerance.


Assuntos
Dessensibilização Imunológica/métodos , Glicoproteínas/administração & dosagem , Linfócitos T/imunologia , Vacinas/administração & dosagem , Western Blotting , Citometria de Fluxo , Glicoproteínas/imunologia , Humanos , Microscopia Confocal , Reação em Cadeia da Polimerase em Tempo Real , Vacinas/imunologia
19.
Phys Rev Lett ; 111(6): 067001, 2013 Aug 09.
Artigo em Inglês | MEDLINE | ID: mdl-23971602

RESUMO

We report an anomalous matching effect in MoGe thin films containing pairs of circular holes arranged in such a way that four of those pairs meet at each vertex point of a square lattice. A remarkably pronounced fractional matching was observed in the magnetic field dependences of both the resistance and the critical current. At the half matching field the critical current can be even higher than that at zero field. This has never been observed before for vortices in superconductors with pinning arrays. Numerical simulations within the nonlinear Ginzburg-Landau theory reveal a square vortex ice configuration in the ground state at the half matching field and demonstrate similar characteristic features in the field dependence of the critical current, confirming the experimental realization of an artificial ice system for vortices for the first time.

20.
Environ Sci Technol ; 47(8): 3933-41, 2013 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-23488675

RESUMO

Several studies have documented reductions in indoor ozone levels that occur as a consequence of its reactions with the exposed skin, hair and clothing of human occupants. One would anticipate that consumption of ozone via such reactions would impact co-occurring products derived from ozone's reactions with various indoor pollutants. The present study examines this possibility for secondary organic aerosols (SOA) derived from ozone-initiated chemistry with limonene, a commonly occurring indoor terpene. The experiments were conducted at realistic ozone and limonene concentrations in a 240 m(3) chamber configured to simulate a typical open office environment. During an experiment the chamber was either unoccupied or occupied with 18-20 workers. Ozone and particle levels were continuously monitored using a UV photometric ozone analyzer and a fast mobility particle sizer (FMPS), respectively. Under otherwise identical conditions, when workers were present in the simulated office the ozone concentrations were approximately two-thirds and the SOA mass concentrations were approximately one-half of those measured when the office was unoccupied. This was observed whether new or used filters were present in the air handling system. These results illustrate the importance of accounting for occupancy when estimating human exposure to pollutants in various indoor settings.


Assuntos
Aerossóis/análise , Poluentes Atmosféricos/análise , Poluição do Ar em Ambientes Fechados/análise , Monitoramento Ambiental , Compostos Orgânicos/análise , Ozônio/química , Local de Trabalho , Cicloexenos/análise , Humanos , Limoneno , Tamanho da Partícula , Material Particulado/química , Terpenos/análise
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