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1.
Rev Esp Anestesiol Reanim (Engl Ed) ; 70(10): 593-595, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37666453

RESUMO

Eosinophilic granulomatosis with polyangiitis (EGPA), also known as Churg-Strauss syndrome, is a rare type of vasculitis with multisystemic involvement. Very few authors have described the anaesthesia technique in these patients. We present the first report on ambulatory surgery in a patient with EGPA. This case dispels concerns about the safety of day surgery and reports successful regional anaesthesia management in a patient with EGPA.


Assuntos
Síndrome de Churg-Strauss , Granulomatose com Poliangiite , Humanos , Síndrome de Churg-Strauss/complicações
2.
AJNR Am J Neuroradiol ; 43(10): 1437-1444, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-36137654

RESUMO

BACKGROUND AND PURPOSE: MCA aneurysms are still commonly clipped surgically despite the recent development of a number of endovascular tools and techniques. We measured clinical uncertainty by studying the reliability of decisions made for patients with middle cerebral artery (MCA) aneurysms. MATERIALS AND METHODS: A portfolio of 60 MCA aneurysms was presented to surgical and endovascular specialists who were asked whether they considered surgery or endovascular treatment to be an option, whether they would consider recruitment of the patient in a randomized trial, and whether they would provide their final management recommendation. Agreement was studied using κ statistics. Intrarater reliability was assessed with the same, permuted portfolio of cases of MCA aneurysm sent to the same specialists 1 month later. RESULTS: Surgical management was the preferred option for neurosurgeons (n = 844/1320; [64%] responses/22 raters), while endovascular treatment was more commonly chosen by interventional neuroradiologists (1149/1500 [76.6%] responses/25 raters). Interrater agreement was only "slight" for all cases and all judges (κ = 0.094; 95% CI, 0.068-0.130). Agreement was no better within specialties or with more experience. On delayed requestioning, 11 of 35 raters (31%) disagreed with themselves on at least 20% of cases. Surgical management and endovascular treatment were always judged to be a treatment option, for all patients. Trial participation was offered to patients 65% of the time. CONCLUSIONS: Individual clinicians did not agree regarding the best management of patients with MCA aneurysms. A randomized trial comparing endovascular with surgical management of patients with MCA aneurysms is in order.


Assuntos
Embolização Terapêutica , Procedimentos Endovasculares , Aneurisma Intracraniano , Humanos , Tomada de Decisão Clínica , Reprodutibilidade dos Testes , Incerteza , Aneurisma Intracraniano/diagnóstico por imagem , Aneurisma Intracraniano/cirurgia , Procedimentos Neurocirúrgicos/métodos , Resultado do Tratamento , Estudos Retrospectivos
4.
J Stroke Cerebrovasc Dis ; 30(8): 105922, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34157670

RESUMO

OBJECTIVES: To determine the predictive value of early transcranial color-coded sonography (TCCS) for intracranial hemorrhage (ICH) in patients with large artery occlusion (LAO) stroke of carotid circulation, who were submitted to endovascular therapy (EVT) with successful reperfusion. MATERIALS AND METHODS: Retrospective study evaluating a cohort of consecutive stroke patients with LAO of the carotid circulation that were recanalyzed with EVT. We measured angle-corrected peak systolic velocities, end-diastolic velocities and mean flow velocities (PSV, EDV and MFV) of the symptomatic and asymptomatic middle cerebral artery (MCA). The ratio between MFV of the symptomatic MCA and MFV of the asymptomatic MCA (MCA-Ra) was calculated. Parenchymal hematoma in the 24 hours control CT was considered as ICH. Univariate associations and multivariate analyses were used to identify early independent predictors for ICH among TCCS findings. RESULTS: We included 234 patients, mean age 72.5 (SD 12.6) years, 52.1% male. The mean time between recanalization and TCCS was 12.3 hours (range 3-22). Patients who developed postinterventional ICH showed a higher MCA-Ra (1.02 ± 0.26 vs 1.16 ± 0,21, p = 0.036). In multivariate analysis, only higher MCA-Ra remained independently associated with postinterventional ICH (OR: 6.778, 95%CI: 1.152-39.892, p = 0.034). A value of MCA-Ra ≥ 1,05 was associated with ICH, showing a sensitivity of 81.3% and a specificity of 65.9%; the AUC based of the ROC analysis was 0.688 (95% CI 0.570-0.806). CONCLUSION: TCCS performed within the first 24 hours after stroke onset can help to predict hemorrhagic transformation in patients with LAO.


Assuntos
Procedimentos Endovasculares/efeitos adversos , Infarto da Artéria Cerebral Média/terapia , Hemorragias Intracranianas/diagnóstico por imagem , AVC Isquêmico/terapia , Trombectomia/efeitos adversos , Ultrassonografia Doppler em Cores , Ultrassonografia Doppler Transcraniana , Idoso , Idoso de 80 Anos ou mais , Velocidade do Fluxo Sanguíneo , Circulação Cerebrovascular , Feminino , Humanos , Infarto da Artéria Cerebral Média/diagnóstico por imagem , Infarto da Artéria Cerebral Média/fisiopatologia , Hemorragias Intracranianas/etiologia , AVC Isquêmico/diagnóstico por imagem , AVC Isquêmico/fisiopatologia , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Sistema de Registros , Reprodutibilidade dos Testes , Estudos Retrospectivos , Medição de Risco , Fatores de Risco , Fatores de Tempo , Resultado do Tratamento
5.
J Investig Allergol Clin Immunol ; 32(1): 33-39, 2021 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-32732183

RESUMO

BACKGROUND AND OBJECTIVES: To analyze component-resolved diagnosis of sensitization to Dermatophagoides pteronyssinus (Der p) in patients with respiratory allergy and the association between diagnostic findings and clinical severity in different geographical areas. METHODS: The study population comprised 217 patients (mean age, 25.85 [12.7] years; 51.16% female) selected from 13 centers in Portugal (5 from the North, n=65). All had allergic rhinitis with or without asthma and positive skin prick test results to at least 1 dust mite. Specific IgE (sIgE) to Der p, Dermatophagoides farinae, Lepidoglyphus destructor, Der p 1, Der p 2, Der p 10, and Der p 23 was determined using ImmunoCAP. The Mann-Whitney test was applied for the following comparisons: rhinitis vs rhinitis and asthma; mild vs moderate-to-severe rhinitis; North vs South. RESULTS: The prevalence of sensitization was 98.2% for Der p, and 72.4%, 89.4%, 9.7%, and 77% for Der p 1, Der p 2, Der p 10, and Der p 23, respectively. The corresponding median sIgE levels were 8.56, 17.7, 0.01, and 3.95 kUA/L. sIgE to all allergens was higher in patients with moderate-to-severe rhinitis and rhinitis with asthma (nonsignficant). Concentrations of sIgE to Der p 2 were significantly higher in the South than in the North (P=.0496). CONCLUSION: The most common sensitization in Portugal was to Der p. The highest prevalence and median sIgE level were observed for Der p 2. All sIgE values for molecular components were higher in more symptomatic patients (nonsignificant). Concentrations of sIgE to Der p 2 were higher in the South, probably because of the warmer temperature and/or the larger sample size.


Assuntos
Antígenos de Dermatophagoides , Dermatophagoides pteronyssinus , Adulto , Alérgenos , Animais , Poeira , Feminino , Humanos , Imunoglobulina E , Masculino , Portugal/epidemiologia , Testes Cutâneos/métodos
6.
AJNR Am J Neuroradiol ; 41(2): 274-279, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-32001446

RESUMO

BACKGROUND AND PURPOSE: The reasons for poor clinical outcome after thrombectomy for acute stroke, concerning around half of all patients, are misunderstood. We developed a hierarchic algorithm based on DWI to better identify patients at high risk of disability. MATERIALS AND METHODS: Our single-center, retrospective study included consecutive patients with acute ischemic stroke who underwent thrombectomy for large anterior artery occlusion and underwent pretreatment DWI. The primary outcome was the mRS at 3 months after stroke onset. Multivariable regression was used to identify independent clinical and imaging predictors of poor prognosis (mRS > 2) at 3 months, and a hierarchic algorithm predictive of disability was developed. RESULTS: A total of 149 patients were analyzed. In decreasing importance, DWI lesion volume of >80 mL, baseline NIHSS score of >14, age older than 75 years, and time from stroke onset to groin puncture of >4 hours were independent predictors of poor prognosis. The predictive hierarchic algorithm developed from the multivariate analysis predicted the risk of disability at 3 months for up to 100% of patients with a high predictive value. The area under the receiver operating characteristic curve was 0.87. CONCLUSIONS: The DWI-based hierarchic algorithm we developed is highly predictive of disability at 3 months after thrombectomy and is easy to use in routine practice.


Assuntos
Algoritmos , Imagem de Difusão por Ressonância Magnética/métodos , Acidente Vascular Cerebral/cirurgia , Trombectomia/métodos , Resultado do Tratamento , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Prognóstico , Curva ROC , Estudos Retrospectivos , Fatores de Risco , Acidente Vascular Cerebral/complicações
8.
Ultrasound Obstet Gynecol ; 54(5): 596-603, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31006923

RESUMO

OBJECTIVE: To evaluate the cost-effectiveness of five prenatal screening strategies for trisomies (13/18/21) and other unbalanced chromosomal abnormalities (UBCA), following the introduction of cell-free DNA (cfDNA) analysis. METHODS: A model-based cost-effectiveness analysis was performed to estimate prevalence, safety, screening-program costs and healthcare costs of five different prenatal screening strategies, using a virtual cohort of 652 653 pregnant women in France. Data were derived from the French Biomedicine Agency and published articles. Uncertainty was addressed using one-way sensitivity analysis. The five strategies compared were: (i) cfDNA testing for women with a risk following first-trimester screening of ≥ 1/250; (ii) cfDNA testing for women with a risk of ≥ 1/1000 (currently recommended); (iii) cfDNA testing in the general population (regardless of risk); (iv) invasive testing for women with a risk of ≥ 1/250 (historical strategy); and (v) invasive testing for women with a risk of ≥ 1/1000. RESULTS: In our virtual population, at similar risk thresholds, cfDNA testing compared with invasive testing was cheaper but less effective. Compared with the historical strategy, cfDNA testing at the ≥ 1/1000 risk threshold was a more expensive strategy that detected 158 additional trisomies, but also 175 fewer other UBCA. Implementation of cfDNA testing in the general population would give an incremental cost-effectiveness ratio of €9 166 689 per additional anomaly detected compared with the historical strategy. CONCLUSION: Extending cfDNA to lower risk thresholds or even to all pregnancies would detect more trisomies, but at greater expense and with lower detection rate of other UBCA, compared with the historical strategy. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.


Relación costo-eficacia de cinco estrategias de cribado prenatal para trisomías y otras anomalías cromosómicas no equilibradas: un análisis basado en modelos OBJETIVO: Evaluar la eficacia en función de los costos de cinco estrategias de cribado prenatal para trisomías (13/18/21) y otras anomalías cromosómicas no equilibradas (UBCA, por sus siglas en inglés), tras la introducción del análisis de ADN fetal (cfDNA, por sus siglas en inglés). MÉTODOS: Se realizó un análisis de la relación costo-eficacia basado en modelos para estimar la prevalencia, la seguridad, los costos de los programas de cribado y los costos sanitarios de cinco estrategias diferentes de cribado prenatal, para lo cual se usó una cohorte virtual de 652 653 mujeres embarazadas en Francia. Los datos se obtuvieron de la Agencia Francesa de Biomedicina y de artículos publicados. La incertidumbre se abordó mediante un análisis de sensibilidad unidireccional. Las cinco estrategias comparadas fueron: (i) pruebas de cfDNA para mujeres con un riesgo ≥1/250 después del examen del primer trimestre; (ii) pruebas de cfDNA para mujeres con un riesgo ≥1/1000 (las recomendadas actualmente); (iii) pruebas de cfDNA en la población general (independientemente del riesgo); (iv) pruebas invasivas para mujeres con un riesgo ≥1/250 (estrategia histórica); y (v) pruebas invasivas para mujeres con un riesgo ≥1/1000. RESULTADOS: En esta población virtual, con umbrales de riesgo similares, la prueba de cfDNA fue más barata pero menos efectiva en comparación con la prueba invasiva. En comparación con la estrategia histórica, la prueba de cfDNA para el umbral de riesgo de ≥1/1000 fue una estrategia más costosa que detectó 158 trisomías adicionales, pero también 175 menos de otras UBCA. La aplicación de las pruebas de cfDNA en la población general daría una relación costo-eficacia incremental de 9 166 689 EUR por cada anomalía adicional detectada en comparación con la estrategia histórica. CONCLUSIÓN: Extender las pruebas de cfDNA a umbrales de riesgo más bajos o incluso a todos los embarazos detectaría más trisomías, pero a un costo mayor y con una tasa de detección más baja de otras UBCA, en comparación con la estrategia histórica.


Assuntos
Ácidos Nucleicos Livres/economia , Síndrome de Down/diagnóstico , Diagnóstico Pré-Natal/economia , Síndrome da Trissomia do Cromossomo 13/diagnóstico , Síndrome da Trissomía do Cromossomo 18/diagnóstico , Estudos de Casos e Controles , Ácidos Nucleicos Livres/normas , Aberrações Cromossômicas/estatística & dados numéricos , Estudos de Coortes , Síndrome de Down/epidemiologia , Síndrome de Down/genética , Feminino , França/epidemiologia , Humanos , Gravidez , Diagnóstico Pré-Natal/métodos , Diagnóstico Pré-Natal/normas , Sensibilidade e Especificidade , Síndrome da Trissomia do Cromossomo 13/epidemiologia , Síndrome da Trissomia do Cromossomo 13/genética , Síndrome da Trissomía do Cromossomo 18/epidemiologia , Síndrome da Trissomía do Cromossomo 18/genética
9.
Leukemia ; 32(4): 874-881, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29089646

RESUMO

Precise classification of acute leukemia (AL) is crucial for adequate treatment. EuroFlow has previously designed an AL orientation tube (ALOT) to guide towards the relevant classification panel (T-cell acute lymphoblastic leukemia (T-ALL), B-cell precursor (BCP)-ALL and/or acute myeloid leukemia (AML)) and final diagnosis. Now we built a reference database with 656 typical AL samples (145 T-ALL, 377 BCP-ALL, 134 AML), processed and analyzed via standardized protocols. Using principal component analysis (PCA)-based plots and automated classification algorithms for direct comparison of single-cells from individual patients against the database, another 783 cases were subsequently evaluated. Depending on the database-guided results, patients were categorized as: (i) typical T, B or Myeloid without or; (ii) with a transitional component to another lineage; (iii) atypical; or (iv) mixed-lineage. Using this automated algorithm, in 781/783 cases (99.7%) the right panel was selected, and data comparable to the final WHO-diagnosis was already provided in >93% of cases (85% T-ALL, 97% BCP-ALL, 95% AML and 87% mixed-phenotype AL patients), even without data on the full-characterization panels. Our results show that database-guided analysis facilitates standardized interpretation of ALOT results and allows accurate selection of the relevant classification panels, hence providing a solid basis for designing future WHO AL classifications.


Assuntos
Leucemia Mieloide Aguda/patologia , Doença Aguda , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Feminino , Humanos , Imunofenotipagem/métodos , Lactente , Recém-Nascido , Masculino , Pessoa de Meia-Idade , Leucemia-Linfoma Linfoblástico de Células Precursoras/patologia , Adulto Jovem
10.
Phys Rev Lett ; 117(14): 147802, 2016 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-27740839

RESUMO

The chain and association dynamics of supramolecular polymer ensembles decisively determines their properties. Using neutron spin echo (NSE) spectroscopy we present molecular insight into the space and time evolution of this dynamics. Studying a well characterized ensemble of linearly associating telechelic poly(ethylene glycol) melts carrying triple H-bonding end groups, we show that H-bond breaking significantly impacts the mode spectrum of the associates. The breaking affects the mode contributions and not the relaxation times as was assumed previously. NSE spectra directly reveal the so far intangible H-bond lifetimes in the supramolecular melt and demonstrate that for both the microscopic and the macroscopic dynamics of the supramolecular ensemble the instantaneous average of the M_{w} distribution governs the system response at least as long as the Rouse picture applies.

11.
Phys Chem Chem Phys ; 17(32): 21005-17, 2015 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-26214587

RESUMO

While it is traditionally accepted that the chain interactions responsible for the elastic response in an elastomeric network are ideally permanent and instantaneously active, the ongoing investigation of self-healing materials reveals that the introduction of self-healing properties into elastomers requires high mechanical integrity under dynamic load conditions, while on long timescales (or at extended temperatures), the chain and bond dynamics must allow for an intrinsic repair of micro cracks occurring during operation and aging. Based on an acrylate-based amorphous ionomer model system with pendant carboxylate groups allowing the systematic variation of the composition and the nature of the counter ion, we demonstrate the interrelation between the morphological, thermal, and mechanical properties, and identify the prerequisites and tools for property adjustment and optimization of self-healing efficiency. While the ion fraction is directly related to the effective network density and elastic performance, the crossover frequency between viscous and elastic behavior is influenced by the nature of the counter ion. In order to achieve reliable elastic response and optimal damage repair, the ion fraction in these systems should be in the range of 5 mol% and the chain dynamics should be appropriate to allow for excellent self-healing behavior at moderate healing temperatures.

12.
AJNR Am J Neuroradiol ; 36(6): 1081-8, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25767186

RESUMO

BACKGROUND AND PURPOSE: Identifying occlusion location is crucial for determining the optimal therapeutic strategy during the acute phase of ischemic stroke. The purpose of this study was to assess the diagnostic efficacy of MR imaging, including conventional sequences plus time-resolved contrast-enhanced MRA in comparison with DSA for identifying arterial occlusion location. MATERIALS AND METHODS: Thirty-two patients with 34 occlusion levels referred for thrombectomy during acute cerebral stroke events were consecutively included from August 2010 to December 2012. Before thrombectomy, we performed 3T MR imaging, including conventional 3D-TOF and gradient-echo T2 sequences, along with time-resolved contrast-enhanced MRA of the extra- and intracranial arteries. The 3D-TOF, gradient-echo T2, and time-resolved contrast-enhanced MRA results were consensually assessed by 2 neuroradiologists and compared with prethrombectomy DSA results in terms of occlusion location. The Wilcoxon test was used for statistical analysis to compare MR imaging sequences with DSA, and the κ coefficient was used to determine intermodality agreement. RESULTS: The occlusion level on the 3D-TOF and gradient-echo T2 images differed significantly from that of DSA (P < .001 and P = .002, respectively), while no significant difference was observed between DSA and time-resolved contrast-enhanced MRA (P = .125). κ coefficients for intermodality agreement with DSA (95% CI, percentage agreement) were 0.43 (0.3%-0.6; 62%), 0.32 (0.2%-0.5; 56%), and 0.81 (0.6%-1.0; 88%) for 3D-TOF, gradient-echo T2, and time-resolved contrast-enhanced MRA, respectively. CONCLUSIONS: The time-resolved contrast-enhanced MRA sequence proved reliable for identifying occlusion location in acute stroke with performance superior to that of 3D-TOF and gradient-echo T2 sequences.


Assuntos
Angiografia Cerebral/métodos , Infarto Cerebral/diagnóstico , Meios de Contraste , Aumento da Imagem/métodos , Interpretação de Imagem Assistida por Computador/métodos , Imageamento Tridimensional/métodos , Angiografia por Ressonância Magnética/métodos , Meglumina , Compostos Organometálicos , Adulto , Idoso , Idoso de 80 Anos ou mais , Angiografia Digital , Infarto Cerebral/cirurgia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Sensibilidade e Especificidade , Trombectomia
13.
Phys Rev Lett ; 113(16): 168302, 2014 Oct 17.
Artigo em Inglês | MEDLINE | ID: mdl-25361284

RESUMO

We present neutron scattering data on the structure and dynamics of melts from polyethylene oxide rings with molecular weights up to ten times the entanglement mass of the linear counterpart. The data reveal a very compact conformation displaying a structure approaching a mass fractal, as hypothesized by recent simulation work. The dynamics is characterized by a fast Rouse relaxation of subunits (loops) and a slower dynamics displaying a lattice animal-like loop displacement. The loop size is an intrinsic property of the ring architecture and is independent of molecular weight. This is the first experimental observation of the space-time evolution of segmental motion in ring polymers illustrating the dynamic consequences of their topology that is unique among all polymeric systems of any other known architecture.


Assuntos
Modelos Químicos , Polietilenoglicóis/química , Fractais , Peso Molecular , Difração de Nêutrons , Termodinâmica
14.
Int J Tuberc Lung Dis ; 18(10): 1202-10, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25216834

RESUMO

SETTING: Tuberculosis (TB) is a global public health concern. Surveillance programmes present invaluable epidemiological information regarding its temporal evolution, particularly for pulmonary tuberculosis (PTB), the most common form of TB and the one that presents the greatest challenge in public health. OBJECTIVES: To characterise, model and predict monthly incidence rates for PTB in Portugal disaggregated by high/low-incidence areas, sex and age groups. DESIGN: PTB monthly incidence rates were estimated based on PTB cases diagnosed in 2000-2010, disaggregated by population and geographic characteristics. Seasonal-trend LOESS (STL) decomposition was employed to model trend and seasonality. Seasonal autoregressive integrated moving average (SARIMA) models were fit to characterise series behaviour and forecast PTB monthly incidence rates. RESULTS: Overall, the time series showed a downward trend in and seasonality of PTB diagnosis, with a peak in March and a trough in December. The mean seasonal amplitude was consistently higher in high-incidence areas, in males and in adults aged 25-54 years. SARIMA models were found to adequately fit and forecast the time series, thus predicting trend and seasonal persistence. CONCLUSIONS: STL and SARIMA findings concurred and were accurate. Endemic PTB seems to be slowly declining and case diagnosis is likely seasonal, which can be expected to persist if past conditions continue.


Assuntos
Tuberculose Pulmonar/diagnóstico , Tuberculose Pulmonar/epidemiologia , Adolescente , Adulto , Idoso , Criança , Pré-Escolar , Feminino , Previsões , Humanos , Incidência , Lactente , Masculino , Pessoa de Meia-Idade , Modelos Teóricos , Portugal/epidemiologia , Estações do Ano , Adulto Jovem
15.
Cell Death Dis ; 4: e774, 2013 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-23949223

RESUMO

Rad54 is an important factor in the homologous recombination pathway of DNA double-strand break repair. However, Rad54 knockout (KO) mice do not exhibit overt phenotypes at adulthood, even when exposed to radiation. In this study, we show that in Rad54 KO mouse the germline is actually altered. Compared with the wild-type (WT) animals, these mice have less premeiotic germ cells. This germ cell loss is found as early as in E11.5 embryos, suggesting an early failure during mutant primordial germ cells development. Both testicular and ovarian KO germ cells exhibited high radiation sensitivity leading to a long-term gametogenesis defect at adulthood. The KO female germline was particularly affected displaying decreased litter size or sterility. Spermatogenesis recovery after irradiation was slower and incomplete in Rad54 KO mice compared with that of WT mice, suggesting that loss of germ stem cell precursors is not fully compensated along the successive rounds of spermatogenesis. Finally, spermatogenesis recovery after postnatal irradiation is in part regulated by glial-cell-line-derived neurotrophic factor (GDNF) in KO but not in irradiated WT mice, suggesting that Sertoli cell GDNF production is stimulated upon substantial germ cell loss only. Our findings suggest that Rad54 has a key function in maintaining genomic integrity of the developing germ cells.


Assuntos
Dano ao DNA , DNA Helicases/metabolismo , Instabilidade Genômica , Células Germinativas/patologia , Proteínas Nucleares/metabolismo , Animais , Contagem de Células , Morte Celular/genética , Morte Celular/efeitos da radiação , Dano ao DNA/efeitos da radiação , DNA Helicases/deficiência , Relação Dose-Resposta à Radiação , Feminino , Feto/metabolismo , Feto/efeitos da radiação , Raios gama , Instabilidade Genômica/efeitos da radiação , Células Germinativas/metabolismo , Células Germinativas/efeitos da radiação , Infertilidade Feminina/embriologia , Infertilidade Feminina/patologia , Cinética , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Proteínas Nucleares/deficiência , Ovário/embriologia , Ovário/patologia , Ovário/efeitos da radiação , Tolerância a Radiação/genética , Tolerância a Radiação/efeitos da radiação , Células de Sertoli/patologia , Espermatogênese/genética , Espermatogênese/efeitos da radiação , Espermatogônias/metabolismo , Espermatogônias/patologia , Espermatogônias/efeitos da radiação , Testículo/embriologia , Testículo/patologia , Testículo/efeitos da radiação
16.
J Phys Chem B ; 116(9): 2664-76, 2012 Mar 08.
Artigo em Inglês | MEDLINE | ID: mdl-22369088

RESUMO

The properties of the light flexible device, ion jelly, which combines gelatin with an ionic liquid (IL) were recently reported being promising to develop safe and highly conductive electrolytes. This article aims for the understanding of the ion jelly conductive mechanism using dielectric relaxation spectroscopy (DRS) in the frequency range 10(-1)-10(6) Hz; the study was complemented with differential scanning calorimetry (DSC) and pulsed field gradient nuclear magnetic resonance (PFG NMR) spectroscopy. The room temperature ionic liquid 1-butyl-3-methylimmidazolium dicyanamide (BMIMDCA) used as received (1.9% w/w water content) and with 6.6% (w/w) of water content and two ion jellies with two different ratios BMIMDCA/gelatin/water % (w/w), IJ1 (41.1/46.7/12.2) and IJ3 (67.8/25.6/6.6), have been characterized. A glass transition was detected by DSC for all materials allowing for classifying them as glass formers. For the ionic liquid, it was observed that the glass transition temperature decreases with the increase of water content. While in subsequent calorimetric runs crystallization was observed for BMIMDCA with negligible water content, no crystallization was detected for any of the ion jelly materials upon themal cycling. To the dielectric spectra of all tested materials, both dipolar relaxation and conductivity contribute; at the lowest frequencies, electrode and interfacial polarization highly dominate. Conductivity, which manifests much more intensity relative to dipolar reorientations, strongly evidences subdiffusive ion dynamics at high frequencies. From dielectric measures, transport properties as mobility and diffusion coefficients were extracted. Data treatment was carried out in order to deconvolute the average diffusion coefficients estimated from dielectric data in its individual contributions of cations (D(+)) and anions (D(-)). The D(+) values thus obtained for IJ3, the ion jelly with the highest IL/gelatin ratio, cover a large temperature range up to room temperature and revealed excellent agreement with direct measurements from PFG NMR, obeying to the same VFT equation. For BMIMDCA(6.6%water), which has the same water amount as IJ3, the diffusion coefficients were only estimated from DRS measurements over a limited temperature range; however, a single VFT equation describes both DRS and PFG NMR data. Moreover, it was found that the diffusion coefficients and mobility are similar for the ionic liquid and IJ3, which points to a role of both water and gelatin weakening the contact ion pair, facilitating the translational motion of ions and promoting its dissociation; nevertheless, it is conceivable the existence of a critical composition of gelatin that leads to those properties. The VFT temperature dependence observed for the conductivity was found to be determined by a similar dependence of the mobility. Both conductivity and segmental motion revealed to be correlated as inferred by the relatively low values of the decoupling indexes. The obtained results show that ion jelly could be in fact a very promising material to design novel electrolytes for different electrochemical devices, having a performance close to the IL but presenting an additional stability regarding electrical measurements and resistance against crystallization relative to the bulk ionic liquid.


Assuntos
Condutividade Elétrica , Íons , Varredura Diferencial de Calorimetria , Espectroscopia de Ressonância Magnética
17.
Rev Med Interne ; 33(5): 244-9, 2012 May.
Artigo em Francês | MEDLINE | ID: mdl-22240290

RESUMO

PURPOSE: Patients with suspected deep vein thrombosis (DVT) are often managed on an outpatient basis. The aim of the study was to validate a clinical prediction rule specifically for use in primary care to help physicians in their decision to start anticoagulant therapy while awaiting ultrasound examination. PATIENTS AND METHODS: Between September 2007 and October 2008, 194 general practitioners prospectively included patients with clinically suspected DVT without clinically suspected pulmonary embolism. All patients underwent a standardized clinical assessment in order to collect items included in the clinical prediction rule (personal history of venous thromboembolism +1, immobilization in previous month+1, estrogen contraceptive+2, active malignancy+3, swelling of the calf+1, the presence of an alternative diagnosis more likely than that of DVT-3. DVT unlikely if score<2, likely if score≥2). RESULTS: Among the 164 included patients, 56 (34%) had DVT of them 28 (17%) had a proximal DVT. Proportions of confirmed DVT were 29% in the unlikely group and 43% in the likely group against 26% and 63% respectively in the derivation study. CONCLUSIONS: This clinical prediction rule might not fulfill the required conditions to be considered as a usable help in the ambulatory management of DVT. Variations of the cut-off value could enhance its performance.


Assuntos
Técnicas de Apoio para a Decisão , Perna (Membro)/irrigação sanguínea , Atenção Primária à Saúde , Trombose Venosa/diagnóstico , Idoso , Feminino , Humanos , Masculino , Estudos Prospectivos
18.
J Chem Phys ; 132(22): 224508, 2010 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-20550409

RESUMO

The nematic liquid crystalline mixture E7 was confined with similar filling degrees to molecular sieves with constant composition but different pore diameters (from 2.8 to 6.8 nm). Fourier transform infrared analysis proved that the E7 molecules interact via the cyanogroup with the pore walls of the molecular sieves. The molecular dynamics of the system was investigated by broadband dielectric spectroscopy (10(-2)-10(9) Hz) covering a wide temperature range of approximately 200 K from temperatures well above the isotropic-nematic transition down to the glass transition of bulk E7. A variety of relaxation processes is observed including two modes that are located close to the bulk behavior in its temperature dependence. For all confined samples, two relaxation processes, at frequencies lower than the processes observed for the bulk, were detected. At lower temperatures, their relaxation rates have different temperature dependencies whereas at higher temperatures, they seem to collapse into one chart. The temperature dependence of the slowest process (S-process) obeys the Vogel-Fulcher-Tammann law indicating a glassy dynamics of the E7 molecules anchored to the pore surface. The pore size dependence of both the Vogel temperature and fragility revealed a steplike transition around 4 nm pore size, which indicates a transition from a strong to a fragile behavior. The process with a relaxation rate in between the bulklike and the S-process (I-process) shows no dependence on the pore size. The agreement of the I-process with the behavior of a 5CB surface layer adsorbed on nonporous silica leads to the assignment of E7 molecules anchored at the outer surface of the microcrystals of the molecular sieves.

20.
J Phys Chem B ; 112(28): 8227-35, 2008 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-18572906

RESUMO

Broadband dielectric spectroscopy (10(-2)-10(9) Hz) was employed to investigate the molecular dynamics of the liquid crystalline mixture E7 confined in both untreated and lecithin-treated 20 nm Anopore membranes. Because E7 does not crystallize, it was possible to cover a temperature range of more than 200 K, providing an exhaustive dielectric characterization of a liquid crystal confined to Anopore membranes for the first time. In the nematic state, the tumbling (alpha-) and the delta-relaxation are observed, also under confinement conditions. The analysis of their relative intensities give that the orientation of the E7 molecules is preferentially axial in untreated but opposite radial in lecithin-treated pores. The radial alignment of the liquid crystals in the modified membrane is understood as a tail-to-tail conformation of E7 molecules imposed by the adsorbed lecithin molecules. The relaxation rate of the alpha-process is enhanced for E7 confined in native Anopore compared with the bulk and E7 in treated pores. This is interpreted as resulting from a less dense molecular packing of E7 in the middle of the pore compared to the bulk. In both untreated and treated membranes, the relaxation rate of the delta-process is higher than in the bulk, and the values of the respective Vogel-Fulcher-Tammann temperatures depend on the actual surface treatment. Additionally, a surface process, due to molecular fluctuations of molecules within an adsorbed layer at the pore wall, was detected.

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