2,339 research outputs found

    Evidence of widespread retinal dysfunction in patients with stargardt disease and morphologically unaffected carrier relatives

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    PURPOSE: To characterize contrast sensitivity (CS) across the visual field for two achromatic spatial-temporal frequencies in 21 families with Stargardt disease (STGD) and to correlate psychophysical impairment with patterns of change in multifocal electroretinography (mfERG). METHODS: Twenty-seven eyes from patients with STGD, 16 eyes from asymptomatic relatives, and 44 age-matched control eyes were included. Chromatic CS function was assessed by comparing protan, deutan, and tritan (Cambridge Color Test; Cambridge Research Systems Ltd., Rochester, UK) and anomaloscope measures (IF-2; Roland Consult, Wiesbaden, Germany). Achromatic CS measures were obtained with custom-made software in nine locations by using randomly interleaved staircases. The first task-low spatial frequency (LSF)-matched the known frequency-doubling method that is believed to activate the magnocellular pathway preferentially. The second included an intermediate spatial frequency (ISF, 3.5 cyc/deg). mfERGs (RETIscan; Roland Consult) were also obtained. Relatives were screened for ABCA4 mutations by ABCR400 microarray and direct sequencing. RESULTS: Central impairment of achromatic and chromatic CS (along the three isolation axes) was observed in STGD. LSF and ISF tasks revealed significant and widespread dysfunction in patients and their morphologically unaffected relatives, 80% of whom were found to be ABCA4 mutation carriers. Significant reduction of P1 amplitudes was also observed in both groups. CONCLUSIONS: CS function is impaired in patients with STGD at distinct spatial-temporal frequencies, which, in addition to the color vision deficits, suggests dual impairment of the magno- parvocellular pathways. STGD morphologically unaffected carriers may show patterns of psychophysical dysfunction that are mirrored by abnormal mfERG response

    Neonatal sepsis – a retrospective analysis 2004 to 2006 of Bissaya Barreto Maternity

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    Introdução: As doenças infecciosas são uma causa frequente de morbi- -mortalidade no período neonatal. O conhecimento da epidemiologia de cada unidade é um factor decisivo para o sucesso da antibioterapia empírica. Objectivos: Caracterizar os episódios de sépsis neonatal (SNN) ocorridos de Janeiro de 2004 a Dezembro de 2006 na Unidade de Cuidados Intensivos Neonatais (UCIN) da Maternidade Bissaya Barreto. Material e métodos: Estudo descritivo retrospectivo dos processos clínicos dos recém-nascidos com o diagnóstico de SNN. Definiu-se sépsis com confirmação laboratorial se dois ou mais critérios clínicos compatíveis, associados a um dos seguintes critérios laboratoriais: a) identificação de qualquer agente patogénico bacteriano na hemocultura ou no líquor cefalo-raquídeo; b) identificação de Staphylococcus coagulase negativo na presença de proteína C reactiva >2,0 mg/dl ou plaquetas <100.000/μl ou relação neutrófilos imaturos / neutrófilos totais >0,2. Definiu-se sépsis clínica quando se verificou: instituição de terapêutica antibiótica durante 5 dias, hemocultura negativa ou não pedida, ausência de infecção noutro local e dois ou mais critérios clínicos compatíveis. No caso de sépsis clínica deveria haver pelo menos também um dos seguintes: proteína C reactiva >2,0 mg/dl; leucócitos >30.000 ou <5.000/μl; relação neutrófilos imaturos / neutrófilos totais >0,2; plaquetas <100 000/μl. Considerou-se SNN precoce ou tardia, respectivamente se início até ou após as 72 horas de vida. Resultados: Cumpriram critérios de inclusão 61 episódios infecciosos (16 precoces e 45 tardios), correspondendo a 58 recém-nascidos. Destes, 50% apresentavam peso de nascimento inferior a 1500 gramas. A idade gestacional variou entre as 25 e as 41 semanas, com mediana de 30 semanas. Da amostra considerada, 45 (73,8%) foram sépsis com confirmação laboratorial e 16 (26,2%) foram sépsis clínicas. Os gérmens isolados foram 26 (57,8%) Staphylococcus coagulase negativos – 17 (37,8%) Staphylococcus epidermidis, 9 (20,0%) outros Staphylococcus coagulase negativos; 9 (20,0%) Escherichia coli; 6 (13,3%) Staphylococcus aureus; 2 (4,4%) Streptococcus do grupo B; 1 (2,2%) Proteus mirabilis; 1 (2,2%) Cândica albicans.A percentagem de resistências da Escherichia coli à ampicilina foi de 77,8%. Houve dois Staphylococcus aureus meticilino-resistentes, ambos sensíveis à vancomicina. Faleceram 6 recém-nascidos com SNN. Comentários: Os nossos resultados estão de acordo com os estudos nacionais e internacionais sobre SNN, salientando-se contudo o diminuto número de Streptococcus do grupo B isolados e o maior número de Escherichia coli, com uma elevada percentagem de estirpes ampicilino- resistentes. A mortalidade relacionada com a SNN encontra-se dentro dos dados referidos na literatura

    Geometrical Constraints on the Cosmological Constant

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    The cosmological constant problem is examined under the assumption that the extrinsic curvature of the space-time contributes to the vacuum. A compensation mechanism based on a variable cosmological term is proposed. Under a suitable hypothesis on the behavior of the extrinsic curvature, we find that an initially large Λ(t)\Lambda(t) rolls down rapidly to zero during the early stages of the universe. Using perturbation analysis, it is shown that such vacuum behaves essentially as a spin-2 field which is independent of the metric.Comment: [email protected], 17 pages, Latex, 2 figures obtained by reques

    Correlates of changes in BMI of children from the Azores islands

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    Objective: To model changes in body mass index (BMI), including its stability, and to investigate the association between physical activity, 1-mile run/walk and levels of gross motor coordination and BMI during 5 consecutive years. Design: A longitudinal study of children 6 years of age at baseline followed at annual intervals over 5 years. Subjects: A total of 285 children (143 boys and 142 girls) were enrolled in grade 1 (age 6 years) and followed through grade 5 (age 10 years). Measurements: BMI was recorded and physical activity was assessed by questionnaire, aerobic fitness was evaluated with the 1-mile run/walk and gross motor coordination was measured with the KTK test battery (Korperkoordination test fur Kinder). Multilevel modelling techniques were for the primary analysis. Results: Changes in BMI showed similar curvilinear trends in boys and girls, with ample inter-individual crossing trajectories that is, low tracking. Longitudinal changes in physical activity (PA) and aerobic fitness were not significantly associated with BMI-changes during the 5 years. Children who were more proficient in their motor coordination showed lower values of BMI during the 5 years. Conclusions: BMI trajectories of both boys and girls show low tracking of BMI-values. Considerable inter-individual variation exists both in baseline BMI-values and changes (velocity and acceleration) over time. PA and fitness were not associated with BMI-changes, but gross motor function was negatively associated with BMI-changes. No gender-specific associations were found. If confirmed in other populations these observations could be translated in the promotion of physical activities that improve gross motor function in children aged 6-10 years. This seems to be of major importance for the physical education curriculum of primary school children

    Evapotranspiração de referência obtida pelo Tanque Classe A e por Penmam Monteith (FAO): influência na determinação do Kc da goiabeira em Petrolina, PE.

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    Esse trabalho teve por objetivo comparar a estimativa da evapotranspiração de referência (ETo), obtida pelos métodos de PenmamMonteith (PM-FAO) e do tanque classe A, na região de Petrolina - PE. As estimativas de ETo foram utilizadas para a determinação do coeficiente de cultura (Kc) da goiabeira cv. Paluma, irrigada por micropaspersão, durante o terceiro ciclo de produção, entre junho e dezembro de 2001. Os valores de ETo estimados pelo tanque classe A foram superiores aos estimados pelo método PM-FAO, com médias de 5,22 e 4,68 mm.dia1, respectivamente. Conseqüentemente, os valores de Kc foram maiores para a ETo estimada pelo método de PM FAO

    Atividade microbiana na rizosfera de goiabeiras micorrizadas e cultivadas em solo infestado com Meloidogyne mayaguensis Rammah & Hirschmann.

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    A utilização de FMA (fungos micorrízicos arbusculares) favorece o crescimento vegetal e diminui os danos causados por fitopatógenos (MAlA et aI. 2006), intluenciando a microbiota do solo
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