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1.
Diabet Med ; 40(2): e14938, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36039920

RESUMO

AIMS: The aim of this study was to determine if single items in the quality of life questionnaire short form 36 (SF36) were associated with cardiovascular events in patients with type 2 diabetes mellitus (T2DM). METHODS: In 756 T2DM patients (260 women) from the CARDIPP study, nine questions from the domains vitality and well-being in SF36 were analysed. Patients, 55-66 years, were recruited in 2005-2008 and followed up until 31 December 2018 for the incidence of major adverse cardiovascular events (MACE), that is, myocardial infarction, stroke or cardiovascular death. RESULTS: Median follow-up time: 11.6 years, during which 119 (16%) MACE occurred. The SF36 items: 'seldom full of pep' (HR 1.2, 95% CI: 1.1-1.4, p = 0.006), 'seldom a lot of energy' (HR 1.3, 95%CI: 1.1-1.5, p < 0.001), 'worn out' (HR 1.2, 95%CI: 1.0-1.4, p = 0.020) and 'seldom happy' (HR 1.2, 95%CI: 1.0-1.4, p = 0.012) were independent risk factors for MACE in separate models, as well as male sex, diabetes duration, HbA1c , sagittal abdominal diameter and aortic pulse wave velocity. The variables 'seldom full of pep' and 'seldom a lot of energy' remained associated with MACE when conducting separate analyses for sexes. Only 'seldom a lot of energy' remained associated with MACE when all items from SF-36 were comprised in the same model. CONCLUSIONS: One single question regarding energy levels from SF36 may be used as an independent risk factor for cardiovascular events in T2DM patients in primary care, for both men and women. This item may be included in future risk assessment for use in clinical practice for cardiovascular risk stratification of T2DM patients. TRIAL REGISTRATION: The study was registered in clinicaltrial.gov (NCT01049737) in 14 January 2010.


Assuntos
Doenças Cardiovasculares , Diabetes Mellitus Tipo 2 , Infarto do Miocárdio , Rigidez Vascular , Humanos , Masculino , Feminino , Diabetes Mellitus Tipo 2/complicações , Diabetes Mellitus Tipo 2/epidemiologia , Análise de Onda de Pulso , Qualidade de Vida , Fatores de Risco , Infarto do Miocárdio/epidemiologia , Infarto do Miocárdio/etiologia , Doenças Cardiovasculares/etiologia , Doenças Cardiovasculares/complicações
2.
SAGE Open Med ; 10: 20503121211073421, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35070314

RESUMO

OBJECTIVES: Fracture liaison services are designed to identify patients needing osteoporosis treatment after a fracture. Some fracture liaison service designs involve a prescreening step, for example, fracture risk assessment tool (FRAX®). Another possible prescreening tools are bone mass density assessment in the acute setting. The aim of this study was to assess the effectiveness of prescreening tools. METHODS: In the present prospective cohort study, women aged >55 years with a radius fracture were included. Patients were recruited at the emergency department after experiencing their fracture. All patients performed fracture risk assessment by fracture risk assessment tool, and bone mass density assessment by digital X-ray radiogrammetry and dual-energy X-ray absorptiometry (prescreening steps) as well as full routine evaluation at the osteoporosis unit (endpoint). The main outcome measures were sensitivity, specificity, predictive values, and area under the curve. RESULTS: Forty-one women were recruited (mean age: 70 ± 8 years). Of these, 54% fulfilled the treatment indication criteria of osteoporosis after a full examination. Fracture risk assessment tool without bone mass density (cutoff ⩾ 15%) for prescreening patients had a high sensitivity (90%) but a low area under the curve (0.50) and specificity (16%). The highest area under the curve (0.73) was found prescreening with bone mass density assessment (dual-energy X-ray absorptiometry or digital X-ray radiogrammetry) having a sensitivity of 59%-86% and specificity of 61%-90%. CONCLUSION: This study, though small, raises questions regarding the effectiveness of using a prescreening step in fracture liaison services for high-risk individuals. In this cohort, FRAX® without bone mass density had a low precision, with a risk of both underestimating and overestimating patients requiring treatment. Bone mass density assessment in the acute setting could improve the precision of prescreening. Further investigations on the effectiveness and health economics of prescreening steps in fracture liaison services are needed.

3.
Microb Drug Resist ; 26(12): 1472-1481, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32315569

RESUMO

The aim of this work was to determine the susceptibility, molecular profile, and clonal relationship in Streptococcus agalactiae (group B Streptococcus [GBS]) isolated from vaginal-rectal swab samples. We worked with 200 isolates collected from pregnant women between 35 and 37 weeks of gestation. The macrolide-lincosamide-streptogramin B (MLSB) resistance phenotypes were determined using the double-disc assay. Susceptibility to erythromycin (ERI) and clindamycin (CLI) was performed with the E-test. Resistance genes ermB and ermTR were detected by polymerase chain reaction. Clonal studies were performed using the random amplification of polymorphic DNA. Twelve (6%) of the isolates were resistant to ERI and 10 (5%) of them to CLI. Fifty percent of the resistant strains corresponded to serotype III, 25% to serotype V, and the remaining 25% to serotype Ia, II, and nontypeable strains. The cMLSB phenotype was detected in eight strains (66.67%) and the iMLSB phenotype in four (33.33%). The minimum inhibitory concentration values were between 1.5 and 16 µg/mL for ERI, and between 1 and 32 µg/mL for CLI. Out of the 25 strains susceptible to ERI and CLI, the presence of the ermB gene was detected in eight of them and the ermTR gene in one strain. The ermB gene was detected in the 12 strains that initially had some macrolide resistance phenotype. The ermTR gene was detected in three out of the four strains with the iMLSB phenotype. The resistance to macrolides in the province of Misiones is due to multiclonal spread. The phenotypic and genotypic characterization of macrolide resistance in GBS strains are crucial to contribute to the correct intrapartum prophylactic antibiotic therapy of allergic pregnant women and the epidemiological surveillance of these strains.


Assuntos
Antibacterianos/farmacologia , Farmacorresistência Bacteriana Múltipla/genética , Lincosamidas/farmacologia , Macrolídeos/farmacologia , Streptococcus agalactiae/genética , Argentina , Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Feminino , Genótipo , Idade Gestacional , Humanos , Testes de Sensibilidade Microbiana , Fenótipo , Reação em Cadeia da Polimerase , Gravidez , Terceiro Trimestre da Gravidez , Streptococcus agalactiae/efeitos dos fármacos
4.
PLoS One ; 12(6): e0179401, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28622349

RESUMO

BACKGROUND: We aimed to study the impact by running 5 km, at maximal speed, on the normal variations of metabolic variables related to glucose, insulin, insulin sensitivity, cortisol, glucagon, Troponin T and metabolic rate. MATERIAL AND METHODS: Five women and 12 men 25.7±5.2 years of age with a body-mass-index of 22.5±2.3 kg/m2 where recruited to run 5 km at individual maximal speed in the morning, and to a corresponding day of rest, followed by standardized breakfast and lunch meals. Blood sampling and measurement of indirect calorimetry were done before and after meals. The participants were randomized regarding the order of the two trial-days in this cross-over study. RESULTS: Insulin and cortisol levels were higher, and insulin sensitivity was lower, on the race-day compared with the day of rest (linear mixed model: p<0.0001 for all three analyses). However, glucose levels and metabolic rate did not differ between the two trial days (p = 0.29 and p = 0.53, respectively). When analyzing specific time-points we found that glucose increased from 5.01±0.37 mmol/l to 6.36 ± 1.3 mmol/l, p<0.0001, by running, while serum insulin concomitantly increased from 42±21 to 90±54 pmol/l, p<0.0001. In accordance, the QUICKI index of serum sensitivity, 1/(log10insulin+log10glucose), was lowered post-race, p<0.0001. Serum cortisol levels increased from 408±137 nmol/l to 644±171 nmol/l, p<0.0001, post-race while serum glucagon levels were unaffected. Troponin T was detectable in serum post-race in 12 out of the 17 participants and reached or surpassed the clinical reference level of 15 ng/l in three subjects. Post-race electrocardiograms displayed no pathologies. CONCLUSIONS: Relatively short running-races can apparently induce a reduction in insulin sensitivity that is not fully compensated by concomitantly increased insulin secretion intended to ensure euglycemia. Since also Troponin T was detected in plasma in a majority of the participants, our data suggest that it is possible to induce considerable metabolic stress by running merely 5 km, when striving for maximal speed.


Assuntos
Glicemia/metabolismo , Hidrocortisona/sangue , Insulina/biossíntese , Corrida/fisiologia , Troponina T/sangue , Adulto , Estudos Cross-Over , Feminino , Humanos , Masculino
5.
Rev. iberoam. micol ; 31(3): 176-181, jul.-sept. 2014.
Artigo em Espanhol | IBECS | ID: ibc-127627

RESUMO

Antecedentes. Aspergillus es un hongo oportunista que provoca infecciones con alta morbimortalidad en pacientes inmunosuprimidos. Aspergillus fumigatus causa frecuentemente infecciones nosocomiales, pero la incidencia de otras especies ha aumentado en los últimos años. Objetivos. Evaluar la carga fúngica aérea y la diversidad de especies de Aspergillus en ambientes hospitalarios con pacientes pediátricos en estado crítico. Métodos. Durante otoño y primavera, cada 15 días, se muestrearon aire y superficies de la Unidad de Terapia Intensiva y la Unidad de Quemados de un hospital pediátrico. Las muestras de aire se tomaron con el SAS Super 100®, y las de superficies, con el método del hisopo. Resultados. Los recuentos de UFC/m3 superaron los niveles admisibles. En la Unidad de Terapia Intensiva se encontró mayor cantidad de UFC/m3 y mayor diversidad de especies de Aspergillus que en la Unidad de Quemados. La carga fúngica y la diversidad de especies dentro de las salas fueron mayores que en los ambientes control. La aplicación conjunta del método del hisopo y del SAS permitió encontrar mayor diversidad de especies. Se aislaron 96 cepas de Aspergillus, de las cuales se identificaron 12 especies. Destacaron por su alta frecuencia Aspergillus sydowii, Aspergillus niger, Aspergillus flavus, Aspergillus terreus y Aspergillus parasiticus. Se aisló Aspergillus fumigatus de ambas salas, especie considerada inaceptable en ambientes internos. Conclusiones. Aspergillus se aisló con una alta frecuencia en estas salas. Muchas de estas especies son de interés en salud pública por ser potenciales patógenos. El control y muestreo del aire es el eje en la prevención de estas infecciones (AU)


Background. Aspergillus is a group of opportunistic fungi that cause infections, with high morbimortality in immunosuppressed patients. Aspergillus fumigatus is the most frequent species in these infections, although the incidence of other species has increased in the last few years. Aims. To evaluate the air fungal load and the diversity of Aspergillus species in hospitals with pediatric patients in critical condition. Methods. The Intensive Care Unit and Burns Unit of a pediatric hospital were sampled every 15 days during the autumn and spring seasons. The air samples were collected with SAS Super 100® and the surface samples were collected by swab method. Results. The UFC/m3 counts found exceeded the acceptable levels. The UFC/m3 and the diversity of Aspergillus species found in the Intensive Care Unit were higher than those found in the Burns Unit. The fungal load and the diversity of species within the units were higher than those in control environments. The use of both methods -SAS and swab- allowed the detection of a higher diversity of species, with 96 strains of Aspergillus being isolated and 12 species identified. The outstanding findings were Aspergillus sydowii, Aspergillus niger, Aspergillus flavus, Aspergillus terreus and Aspergillus parasiticus, due to their high frequency. Aspergillus fumigatus, considered unacceptable in indoor environments, was isolated in both units. Conclusions. Aspergillus was present with high frequency in these units. Several species are of interest in public health for being potential pathogenic agents. Air control and monitoring are essential in the prevention of these infections (AU)


Assuntos
Humanos , Masculino , Feminino , Criança , Aspergillus/isolamento & purificação , Aspergillus/patogenicidade , Infecção Hospitalar/complicações , Infecção Hospitalar/microbiologia , Cuidados Críticos/métodos , Cuidados Críticos/estatística & dados numéricos , Cuidados Críticos/normas , Controle de Doenças Transmissíveis/organização & administração , Controle de Doenças Transmissíveis/normas , Monitoramento Epidemiológico/organização & administração , Infecção Hospitalar/prevenção & controle , Estudos de Amostragem , Indicadores de Morbimortalidade , Micologia/métodos , Micologia/estatística & dados numéricos , Micologia/tendências
6.
Rev Iberoam Micol ; 31(3): 176-81, 2014.
Artigo em Espanhol | MEDLINE | ID: mdl-24120420

RESUMO

BACKGROUND: Aspergillus is a group of opportunistic fungi that cause infections, with high morbimortality in immunosuppressed patients. Aspergillus fumigatus is the most frequent species in these infections, although the incidence of other species has increased in the last few years. AIMS: To evaluate the air fungal load and the diversity of Aspergillus species in hospitals with pediatric patients in critical condition. METHODS: The Intensive Care Unit and Burns Unit of a pediatric hospital were sampled every 15 days during the autumn and spring seasons. The air samples were collected with SAS Super 100(®) and the surface samples were collected by swab method. RESULTS: The UFC/m(3) counts found exceeded the acceptable levels. The UFC/m(3) and the diversity of Aspergillus species found in the Intensive Care Unit were higher than those found in the Burns Unit. The fungal load and the diversity of species within the units were higher than those in control environments. The use of both methods -SAS and swab- allowed the detection of a higher diversity of species, with 96 strains of Aspergillus being isolated and 12 species identified. The outstanding findings were Aspergillus sydowii, Aspergillus niger, Aspergillus flavus, Aspergillus terreus and Aspergillus parasiticus, due to their high frequency. Aspergillus fumigatus, considered unacceptable in indoor environments, was isolated in both units. CONCLUSIONS: Aspergillus was present with high frequency in these units. Several species are of interest in public health for being potential pathogenic agents. Air control and monitoring are essential in the prevention of these infections.


Assuntos
Microbiologia do Ar , Aspergillus/isolamento & purificação , Contaminação de Equipamentos , Unidades Hospitalares , Criança , Estado Terminal , Hospitais , Humanos , Estações do Ano
7.
Ups J Med Sci ; 118(4): 247-55, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23977864

RESUMO

BACKGROUND: The improvement of insulin sensitivity by exercise has been shown to be inhibited by supplementation of vitamins acting as antioxidants. OBJECTIVE: To examine effects of exercise with or without blueberries, containing natural antioxidants, on cardio-metabolic risk factors. METHODS: Fifteen healthy men and 17 women, 27.6 ± 6.5 years old, were recruited, and 26 completed a randomized cross-over trial with 4 weeks of exercise by running/jogging 5 km five times/week and 4 weeks of minimal physical activity. Participants were also randomized to consume 150 g of blueberries, or not, on exercise days. Laboratory variables were measured before and after a 5 km running-race at maximal speed at the beginning and end of each period, i.e. there were four maximal running-races and eight samplings in total for each participant. RESULTS: Insulin and triglyceride levels were reduced while HDL-cholesterol increased by exercise compared with minimal physical activity. Participants randomized to consume blueberries showed an increase in fasting glucose levels compared with controls, during the exercise period (blueberries: from 5.12 ± 0.49 mmol/l to 5.32 ± 0.29 mmol/l; controls: from 5.24 ± 0.27 mmol/l to 5.17 ± 0.23 mmol/l, P = 0.04 for difference in change). Triglyceride levels fell in the control group (from 1.1 ± 0.49 mmol/l to 0.93 ± 0.31 mmol/l, P = 0.02), while HDL-cholesterol increased in the blueberry group (from 1.51 ± 0.29 mmol/l to 1.64 ± 0.33 mmol/l, P = 0.006). CONCLUSIONS: Ingestion of blueberries induced differential effects on cardio-metabolic risk factors, including increased levels of both fasting glucose and HDL-cholesterol. However, since it is possible that indirect effects on food intake were induced, other than consumption of blueberries, further studies are needed to confirm the findings.


Assuntos
Mirtilos Azuis (Planta) , Doenças Cardiovasculares/prevenção & controle , Dieta , Exercício Físico , Adulto , Antioxidantes/química , Glicemia/análise , HDL-Colesterol/metabolismo , LDL-Colesterol/metabolismo , Estudos Cross-Over , Feminino , Voluntários Saudáveis , Humanos , Insulina/metabolismo , Masculino , Pessoa de Meia-Idade , Projetos Piloto , Fatores de Risco , Triglicerídeos/metabolismo , Troponina T/sangue , Adulto Jovem
8.
Rev. cuba. hig. epidemiol ; 51(2): 129-139, mayo-ago. 2013.
Artigo em Espanhol | LILACS | ID: lil-685288

RESUMO

Introducción: Si bien Streptococcus agalactiae es comensal del tracto gastrointestinal y genitourinario, es la principal causa de enfermedades invasivas y de mortalidad en niños recién nacidos. La infección puede adquirirse a través de la aspiración de líquido amniótico infectado o durante el paso por el canal de parto. Objetivos: comparar la utilidad de diversos métodos de conservación de cepas de Streptococcus agalactiae que resulten reproducibles, accesibles a laboratorios de baja y mediana complejidad, y asegurar su estabilidad fenotípica y genotípica mediante el método de preservación llamado subcultivo continuo, para el mantenimiento del cultivo en medio adecuado con transferencias a medio fresco a intervalos variables. Métodos: Se seleccionaron al azar 40 cepas de Streptococcus agalactiae, las que se sometieron a verificación de viabilidad, pureza y caracterización fenotípica y genotípica antes y después de ser sometidas a conservación, utilizando idénticos medios, reactivos y metodología en ambas circunstancias. Se probaron diferentes medios de preservación de las cepas, que permitieran a laboratorios de baja y mediana complejidad su traslado a centros especializados para la vigilancia adecuada del organismo. Las cepas se conservaron durante nueve meses con subcultivos que mostraron las características originales. Resultados: Los medios más efectivos fueron ATS-TA y LD 4 %-SO-20 ºC, ya que garantizaron viabilidad, pureza y estabilidad fenotípica y genotípica de las cepas. Se demostró que el uso de este medio es una alternativa adecuada para la conservación de Streptococcus agalactiae en laboratorios donde la liofilización y la desecación no están disponibles y que son de bajo costo, rápidos y muy fáciles de usar en la práctica habitual. Conclusiones: los medios ATS-TA y LD 4 %-SO-20 ºC constituyen una buena alternativa para cortos períodos de preservación y transporte de cepas de Streptococcus agalactiae en laboratorios de baja y mediana complejidad.


Introduction: Although Streptococcus agalactiae is commensal of the gastrointestinal and genitourinary tract, it is the main cause of invasive diseases and mortality in newborns. The infection can be acquired through the aspiration of infected amniotic fluid or during the passage through the birth canal. Objectives: to compare the effectiveness of various methods for the conservation of Streptococcus agalactiae strains that can be reproducible and accessible to laboratories of low and medium complexity and guarantee their phenotypic and genotypic stability through a preservation method called continuous subculture, for the maintenance of the culture in an adequate environment with fresh medium transfers at variable interval periods. Methods: 40 strains of Streptococcus agalactiae were randomly selected, which were subjected to verification of viability, purity and genotypic and phenotypic characterization before and after being subjected to conservation, using identical environments, reactive and methodologies in both circumstances. Different means of preservation of strains were tested, which allowed laboratories of low and medium complexity their transfer to specialized centers for the proper surveillance of the organism. The strains were kept for nine months with subcultures that showed original characteristics. Results: The most effective environments were ATS-TA and LD-4 % -SO-20 ºC because they guaranteed viability, purity and genotypic and phenotypic stability of the strains. It was shown that the use of this environment is an adequate alternative for the conservation of Streptococcus agalactiae in laboratories where lyophilization and dessication are not available and are low cost, fast and very easy to use in regular practice. Conclusions: The ATS-TA and LD-4 % -SO-20 ºC environments are a good alternative for short periods of preservation and transportation of Streptococcus agalactiae strains in laboratories of low and medium complexity.

9.
Scand J Clin Lab Invest ; 72(6): 471-8, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22935042

RESUMO

OBJECTIVE: To prospectively evaluate the effects of resistance training combined with increased energy intake or protein-supplementation on lean body-mass, resting metabolic-rate (RMR) and cardiovascular risk factors. METHODS: Twenty-four healthy males (aged 19-32 years) performed resistance exercise for 12 weeks aiming for at least 1 hour training-sessions 3 times a week. The participants were randomized to consume extra protein (33 g whey protein/day) or a meal of fast-food/day (1350 kcal, 41 g protein). Body-composition was measured with Dual-Energy X-ray Absorptiometry (DEXA) and RMR by indirect calorimetry. Fasting blood samples were drawn before and after the 3-month training period and after 12 months. RESULTS: The body weight increased from 75.1 ± 6.9 kg to 78.7 ± 7.2 kg (p < 0.0001), without differences between the groups. RMR increased from 1787 ± 143 kcal/24 h to 1954 ± 187 kcal/24 h (p < 0.0001, N = 24), which was more than expected from the increase in lean body-mass (increase from 59.7 ± 4.3 kg to 61.8 ± 4.1 kg p = 0.004). Fasting serum-insulin levels increased in the fast-food group compared with the extra-protein group (p = 0.03). ApoB increased from 0.691 ± 0.14 g/L to 0.768 ± 0.17 g/L, p = 0.004, in the fast-food group only. Long-term follow up after 12 months showed that RMR, body weight, total fat and lean body-masses did not differ from baseline (n = 19). CONCLUSIONS: Resistance training for 12 weeks increased RMR and lean body-mass similarly when based on either an increased energy-intake or protein supplement. However, the increase in RMR was higher than expected from the increase in lean body-mass. Thus resistance training could potentially decrease the risk of obesity by induction of increased RMR.


Assuntos
Metabolismo Basal/efeitos dos fármacos , Proteínas Alimentares/farmacologia , Suplementos Nutricionais , Fast Foods , Treinamento Resistido , Adulto , Peso Corporal/efeitos dos fármacos , Seguimentos , Humanos , Masculino , Descanso/fisiologia , Fatores de Tempo , Adulto Jovem
10.
Cognition ; 115(1): 79-92, 2010 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-20035934

RESUMO

Studies from many languages consistently report that subject relative clauses (SR) are easier to process than object relatives (OR). However, Hsiao and Gibson (2003) report an OR preference for Chinese, a finding that has been contested. Here we report faster OR versus SR processing in Basque, an ergative, head-final language with pre-nominal relative clauses. A self-paced reading task was used in Experiments 1 and 2, while ERPs were recorded in Experiment 3. We used relative clauses that were ambiguous between an object or subject-gap interpretation and disambiguated later in the sentence. The results of Experiments 1 and 2 showed that SR took longer to read than OR in the critical disambiguating region. In addition, Experiment 3 showed that SR produced larger amplitudes than OR in the P600 window immediately after reading the critical disambiguating word. Our results suggest that SR are not universally easier to process. They cast doubts on universal hypotheses and suggest that processing complexity may depend on language-specific aspects of grammar.


Assuntos
Compreensão/fisiologia , Idioma , Análise de Variância , Atenção/fisiologia , Mapeamento Encefálico , Córtex Cerebral/fisiologia , Eletroencefalografia , Potenciais Evocados/fisiologia , Lateralidade Funcional/fisiologia , Humanos , Linguística , Leitura
11.
J Cogn Neurosci ; 22(8): 1870-87, 2010 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-19580390

RESUMO

The goal of the present study was to investigate the electrophysiological correlates of second-language (L2) morphosyntactic processing in highly proficient late learners of an L2 with long exposure to the L2 environment. ERPs were collected from 22 English-Spanish late learners while they read sentences in which morphosyntactic features of the L2 present or not present in the first language (number and gender agreement, respectively) were manipulated at two different sentence positions-within and across phrases. The results for a control group of age-matched native-speaker Spanish participants included an ERP pattern of LAN-type early negativity followed by P600 effect in response to both agreement violations and for both sentence positions. The late L2 learner results included a similar pattern, consisting of early negativity followed by P600, in the first sentence position (within-phrase agreement violations) but only P600 effects in the second sentence position (across-phrase agreement violation), as well as significant amplitude and onset latency differences between the gender and the number violation effects in both sentence positions. These results reveal that highly proficient learners can show electrophysiological correlates during L2 processing that are qualitatively similar to those of native speakers, but the results also indicate the contribution of factors such as age of acquisition and transfer processes from first language to L2.


Assuntos
Mapeamento Encefálico , Potenciais Evocados Visuais/fisiologia , Aprendizagem/fisiologia , Multilinguismo , Leitura , Adolescente , Adulto , Fatores Etários , Análise de Variância , Criança , Eletroencefalografia/métodos , Feminino , Lateralidade Funcional/fisiologia , Humanos , Testes de Linguagem , Masculino , Tempo de Reação/fisiologia , Adulto Jovem
12.
Psychophysiology ; 46(5): 1113-22, 2009 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-19515107

RESUMO

One key issue for computational models of visual-word recognition is the time course of orthographic and phonological information during reading. Previous research, using both behavioral and event related brain potential (ERP) measures, has shown that orthographic codes are activated very early but that phonological activation starts to occur immediately afterward. Here we report an ERP masked priming experiment in Spanish that investigates this issue further by using very strict control conditions. The critical phonological comparison was between two pairs of primes having the same orthographic similarity to the target words but differing in phonological similarity (e.g., conal-CANAL vs. cinal-CANAL vis à vis ponel-PANEL vs. pinel-PANEL), whereas the critical orthographic contrast was between pairs of primes that had the same phonological similarity to the target but differing in orthographic similarity (e.g., conal-CANAL vs. konal-CANAL). Orthographic priming was mainly observed in the 150-250-ms time window whereas phonological priming occurred in the 350-550-ms window.


Assuntos
Sinais (Psicologia) , Potenciais Evocados/fisiologia , Reconhecimento Psicológico/fisiologia , Adolescente , Adulto , Eletroencefalografia , Feminino , Humanos , Idioma , Masculino , Psicolinguística , Desempenho Psicomotor/fisiologia , Leitura , Adulto Jovem
13.
Hum Brain Mapp ; 30(9): 3079-88, 2009 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-19172625

RESUMO

This article investigates the neural representation of the processes involved in recognizing multisyllabic words in Spanish asking whether lexical and sublexical processes are reflected in a different neuronal activation pattern. High and low frequency words were presented for lexical decision in two different colors. In the congruent condition the color boundaries matched the limit of the first syllable, whereas in the incongruent condition color boundaries and syllable boundaries did not match. The results revealed robust and dissociable brain activations for lexical frequency and syllable-color congruency, but no interaction between the two. We interpreted the greater activation for low relative to high frequency words in the left pre/SMA region, and in the insula/inferior frontal cortex bilaterally to reflect a differential recruitment of lexico-phonological and/or semantic processes. In contrast, we considered two interpretations for the greater deactivation in the precuneus for both lexical frequency and syllable-color congruency words, and in the thalami and a frontal area for syllable-color congruency words only. The deactivations may reflect the differential engagement of semantic processing or may result from the differential allocation of attentional resources. Importantly, while a differential deactivation pattern was observed in the precuneus region for lexicality and syllable-color congruency, BOLD deconvolution revealed a remarkable difference in timing of the two effects with a much earlier deactivation peak for the syllable-color congruency factor. Thus, effects of lexical frequency and syllable-color congruency on brain activation show an important dissociation between lexical and sublexical processes during visual word recognition of multisyllabic words.


Assuntos
Encéfalo/fisiologia , Idioma , Rede Nervosa/fisiologia , Reconhecimento Visual de Modelos/fisiologia , Leitura , Comportamento Verbal/fisiologia , Adulto , Atenção/fisiologia , Encéfalo/anatomia & histologia , Mapeamento Encefálico/métodos , Circulação Cerebrovascular/fisiologia , Visão de Cores/fisiologia , Feminino , Lobo Frontal/anatomia & histologia , Lobo Frontal/fisiologia , Humanos , Testes de Linguagem , Imageamento por Ressonância Magnética/métodos , Masculino , Rede Nervosa/anatomia & histologia , Testes Neuropsicológicos , Estimulação Luminosa , Tálamo/anatomia & histologia , Tálamo/fisiologia , Adulto Jovem
14.
J Cogn Neurosci ; 21(2): 275-88, 2009 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-18510451

RESUMO

To investigate the neural bases of consonant and vowel processing, event-related potentials (ERPs) were recorded while participants read words and pseudowords in a lexical decision task. The stimuli were displayed in three different conditions: (i) simultaneous presentation of all letters (baseline condition); (ii) presentation of all letters, except that two internal consonants were delayed for 50 msec (consonants-delayed condition); and (iii) presentation of all letters, except that two internal vowels were delayed for 50 msec (vowels-delayed condition). The behavioral results showed that, for words, response times in the consonants-delayed condition were longer than in the vowels-delayed condition, which, in turn, were longer than in the baseline condition. The ERPs showed that, starting as early as 150 msec, words in the consonants-delayed condition produced a larger negativity than words in vowels-delayed condition. In addition, there were peak latency differences and amplitude differences in the P150, N250, P325, and N400 components between the baseline and the two letter-delayed conditions. We examine the implications of these findings for models of visual-word recognition and reading.


Assuntos
Discriminação Psicológica/fisiologia , Potenciais Evocados/fisiologia , Tempo de Reação/fisiologia , Leitura , Percepção da Fala/fisiologia , Mapeamento Encefálico/métodos , Eletroencefalografia , Feminino , Humanos , Masculino , Estimulação Luminosa/métodos , Vocabulário , Adulto Jovem
15.
Psychophysiology ; 46(1): 34-42, 2009 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-18992069

RESUMO

One key issue for any computational model of visual-word recognition is the choice of an input coding scheme for assigning letter position. Recent research has shown that pseudowords created by transposing two letters are very effective at activating the lexical representation of their base words (e.g., relovution activates REVOLUTION). We report a masked priming lexical decision experiment in which the pseudoword primes were created by transposing/replacing two consonants or two vowels while event-related potentials were recorded. The results showed a modulation of the amplitude at an early window (150-250 ms) and at the N400 component for vowels but not for consonant transpositions. In addition, the peak latencies were faster for transposed than replaced consonants. These results suggest that consonants and vowels play a different role during the process of visual word recognition. We examine the implications for the choice of an input coding scheme in models of visual-word recognition.


Assuntos
Leitura , Reconhecimento Psicológico/fisiologia , Adolescente , Adulto , Sinais (Psicologia) , Eletroencefalografia , Eletrofisiologia , Feminino , Humanos , Estimulação Luminosa , Psicolinguística , Desempenho Psicomotor/fisiologia , Adulto Jovem
16.
Neurosci Lett ; 419(3): 219-24, 2007 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-17507160

RESUMO

Recent research has shown that pseudowords created by transposing letters are very effective for activating the lexical representation of their base words (e.g., relovution activates REVOLUTION). Furthermore, pseudoword transpositions of consonants are more similar to their corresponding base words than the transposition of vowels. We report one experiment using pseudowords created by the transposition of two consonants, two vowels, and their corresponding control conditions (i.e., the replacement of two consonants or two vowels) in a lexical decision task while Event Related Potentials (ERPs) were recorded. The results showed a modulation of the amplitude of the N400 component as a function of the type of pseudoword (transposed-letter versus replacement letter pseudowords), and this modulation was different for transposed consonants and vowels. These results suggest that consonants and vowels play a different role during word processing.


Assuntos
Mapeamento Encefálico , Idioma , Reconhecimento Visual de Modelos/fisiologia , Leitura , Adolescente , Adulto , Potenciais Evocados , Feminino , Humanos , Masculino
17.
J Cogn Neurosci ; 17(11): 1803-17, 2005 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-16269115

RESUMO

A number of behavioral studies have suggested that syllables might play an important role in visual word recognition in some languages. We report two event-related potential (ERP) experiments using a new paradigm showing that syllabic units modulate early ERP components. In Experiment 1, words and pseudowords were presented visually and colored so that there was a match or a mismatch between the syllable boundaries and the color boundaries. The results showed color-syllable congruency effects in the time window of the P200. Lexicality modulated the N400 amplitude, but no effects of this variable were obtained at the P200 window. In Experiment 2, high- and low-frequency words and pseudowords were presented in the congruent and incongruent conditions. The results again showed congruency effects at the P200 for low-frequency words and pseudowords, but not for high-frequency words. Lexicality and lexical frequency effects showed up at the N400 component. The results suggest a dissociation between syllabic and lexical effects with important consequences for models of visual word recognition.


Assuntos
Potenciais Evocados Visuais/fisiologia , Reconhecimento Psicológico/fisiologia , Aprendizagem Verbal/fisiologia , Percepção Visual/fisiologia , Vocabulário , Adulto , Análise de Variância , Mapeamento Encefálico , Interpretação Estatística de Dados , Eletroencefalografia/métodos , Feminino , Humanos , Masculino , Estimulação Luminosa/métodos , Tempo de Reação/fisiologia , Fatores de Tempo
18.
Neuroreport ; 15(3): 545-8, 2004 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-15094520

RESUMO

A lexical decision experiment was conducted while event related potentials (ERPs) were recorded. The word frequency and the first syllable frequency of each word were manipulated. Results showed that, while high frequency words produced less negative amplitudes in the N400 time window than low frequency words, the inverse pattern was found for syllable frequency. Words containing high frequency syllables produced more negative amplitudes than words containing low frequency syllables. Importantly, a significant syllable frequency effect was also obtained at the P200 time window. The results are interpreted in the framework of an interactive activation model, in which high frequency syllables produce the initial activation of a larger number of lexical candidates during the analysis of orthographic or phonological representations, which have to be inhibited later to allow the identification of a unique word. These findings support the idea that, at least in languages with clear syllabic boundaries, syllables are functional sublexical units during visual word recognition.


Assuntos
Leitura , Adolescente , Adulto , Interpretação Estatística de Dados , Tomada de Decisões , Eletroencefalografia , Potenciais Evocados/fisiologia , Feminino , Humanos , Idioma , Masculino , Modelos Neurológicos , Estimulação Luminosa
20.
Rev. Inst. Med. Trop. Säo Paulo ; 42(1): 9-15, Jan.-Feb. 2000. tab, graf
Artigo em Inglês | LILACS | ID: lil-254823

RESUMO

Diarrheagenics Escherichia coli are the major agents involved in diarrheal disease in developing countries. The aim of this study was to evaluate the time of appearance of the first asymptomatic infection by the different categories of diarrheagenic E. coli in 44 children since their birth and during the first 20 months of their lives. In all of the children studied, we detected at least one category of diarrheagenic E. coli through the 20 months of the study. 510 diarrheagenic E. coli (33.5 percent) were obtained from the 1,524 samples collected from the 44 children during the time of the study (31.4 percent EAggEC, 28.8 percent EPEC, 27.1 percent DAEC, and 12.7 percent ETEC). Neither EHEC nor EIEC were identified. The median age for diarrheagenic E. coli colonization was 7.5 months. The mean weaning period was 12.8 months and the mean age for introduction of mixed feeding (breast fed supplemented) was 3.8 months. A significantly lower incidence of diarrheal disease and asymptomatic infections was recorded among the exclusively breast-fed rather than in the supplemented and non breast-fed infants. For ETEC, EPEC and EAggEC the introduction of weaning foods and complete termination of breast-feeding were associated with an increase of asymptomatic infections


Assuntos
Humanos , Lactente , Recém-Nascido , Diarreia Infantil/microbiologia , Infecções por Escherichia coli/microbiologia , Argentina , Aleitamento Materno , Sondas de DNA , Escherichia coli/classificação , Escherichia coli/isolamento & purificação , Seguimentos , Fatores de Risco , Fatores de Tempo
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