936 resultados para Pretérito perfecto simple


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El TDA-H es un trastorno que no solo afecta y dificulta al niño su aprendizaje, sino que sus relaciones sociales, su entorno se ven trastornados. Lo que provoca al niño con TDA-H un sentimiento de soledad y de inseguridad que afecta negativa y directamente a su autoestima, lo que acrecienta aun más su problemática. Por ello es importante que familia y escuela se alíen a la hora de luchar contra este trastorno, haciendo partícipe al niño en esta lucha, donde el trió familia-escuela-niñoTDA-H han de trabajar de manera simbiótica, para que el niño pueda superar todas las dificultades que este trastorno arrastra con él. El diagnostico temprano es imprescindible, pero se debe empezar a trabajar a partir de las primeras alarmas que se despierten y que suelen despertarse en la escuela. Esto aliviará e incluso esquivará algunos de los golpes que este niño TDA-H tendrá que ir superando, hasta iniciar su correcto tratamiento.

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In Nigeria, schistosomiasis, caused predominantly by the species Schistosoma haematobium, is highly endemic in resource-poor communities. We performed a school-based survey in two rural communities in Osun State (Southwestern Nigeria) and assessed macrohaematuria, microhaematuria and proteinuria as indirect indicators for the presence of disease. Urine samples were inspected macroscopically for haematuria and screened for microhaematuria and proteinuria using urine reagent strips. The microscopic examination of schistosome eggs was used as the gold standard for diagnosis. In total, 447 schoolchildren were included in this study and had a 51% prevalence of urinary schistosomiasis. The sensitivity of microhaematuria (68%) and proteinuria (53%) for infection with S. haematobium was relatively low. In patients with a heavy infection (>500 eggs/10 mL), the sensitivity of microhaematuria was high (95%). When the presence of macrohaematuria and the concomitant presence of microhaematuria and proteinuria were combined, it revealed a sensitivity of 63%, a specificity of 93% and a positive predictive value of 91%. Macrohaematuria also showed high specificity (96%) and a positive predictive value of 92%, while sensitivity was < 50%. These data show that combining urine reagent strip tests (presence of proteinuria and microhaematuria) and information on macrohaematuria increased the accuracy of the rapid diagnosis of urinary schistosomiasis in an endemic rural West African setting. This simple approach can be used to increase the quality of monitoring of schistosomiasis in schoolchildren.

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In the accounting literature, interaction or moderating effects are usually assessed by means of OLS regression and summated rating scales are constructed to reduce measurement error bias. Structural equation models and two-stage least squares regression could be used to completely eliminate this bias, but large samples are needed. Partial Least Squares are appropriate for small samples but do not correct measurement error bias. In this article, disattenuated regression is discussed as a small sample alternative and is illustrated on data of Bisbe and Otley (in press) that examine the interaction effect of innovation and style of use of budgets on performance. Sizeable differences emerge between OLS and disattenuated regression

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OBJECTIVE: To test the ability of a novel phase-shifting medium (PSM) to provide sustained distension of the uterine cavity and produce saline infusion sonography (SIS)-like images in a simplified contrast ultrasound procedure. DESIGN: Prospective pilot feasibility trial of a new diagnostic procedure, contrast ultrasound. SETTING: Clinical reproductive endocrine and infertility unit of regional teaching hospital. PATIENT(S): Twenty-six asymptomatic infertile women (group I) and 27 women presenting with dysfunctional uterine bleeding (DUB) who were scheduled for exploratory surgery (group II). INTERVENTION(S): All women who were temporarily on oral contraceptive first had a regular pelvic ultrasound followed by the intrauterine instillation of up to 3 mL PSM, using a regular insemination catheter, after which all instruments were removed and a regular ultrasound was performed again. RESULT(S): In all 53 women, intrauterine instillation of 1-3 mL PSM resulted in a 3-7 mm uterine distension, sufficient to produce SIS-like images of the uterine cavity that lasted 7-10 min. Contrast ultrasound revealed an endometrial polyp in 3 asymptomatic women of group I. In group II. 12 of 14 women (86%) whose vaginal ultrasound were positive or dubious had positive findings with contrast ultrasound; 9 of 12 patients whose vaginal ultrasounds were negative also had positive contrast ultrasound findings. All the positive and negative findings of contrast ultrasound made in group II were confirmed anatomically (sensitivity and specificity of 100%), whereas the correlation for standard vaginal ultrasound was markedly lower at 57.1% and 85.7%, respectively. Most patients (46 of 53) reported no discomfort during or after the procedure, and 7 women described the procedure as mildly uncomfortable. CONCLUSION(S): Contrast ultrasound, a novel simple diagnostic procedure conducted after intrauterine instillation of 1-3 mL PSM using a simple plastic catheter, delivered SIS-quality images in asymptomatic (group I) and symptomatic (group II) patients while retaining the simplicity of standard ultrasound. We therefore foresee broad application of contrast ultrasound for sensitive and specific assessment for uterine pathologies in the physician's office.

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BACKGROUND: Dermatophyte identification in tinea capitis is essential for choosing the appropriate treatment and in tinea infections to identify the possible source. The failure of fungi to grow in cultures frequently occurs, especially in cases of previous antifungal therapy. OBJECTIVES: To develop a rapid polymerase chain reaction (PCR) sequencing assay for dermatophyte identification in tinea capitis and tinea corporis. MATERIAL AND METHODS: Fungal DNA was extracted from hair and skin samples that were confirmed to be positive by direct mycological examination. Dermatophytes were identified by the sequence of a 28S ribosomal DNA subunit amplicon generated by nested PCR. RESULTS: Nested PCR was found to be necessary to obtain amplicons in substantial amounts for dermatophyte identification by sequencing. The results agreed with those of classical mycological identification in 14 of 23, 6 of 10, and 20 of 23 cases of tinea capitis, tinea corporis and tinea pedis, respectively, from which a dermatophyte was obtained in culture. In seven of the 56 cases, another dermatophyte was identified, revealing previous misidentification. A dermatophyte was identified in 12 of 18, three of five, and four of nine cases of tinea capitis, tinea corporis and tinea pedis, respectively, in cases in which no dermatophyte grew in culture. CONCLUSIONS: Although the gold standard dermatophyte identification from clinical samples remains fungal cultures, the assay developed in the present study is especially suitable for tinea capitis. Improved sensitivity for the identification of dermatophyte species was obtained as it is possible to identify the dermatophyte when the fungus fails to grow in cultures.

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Actualmente no se disponen de marcadores biológicos específicos para la cáncer de próstata produciéndose en muchas ocasiones biopsias prostáticas innecesarias o un sobretratamientos para cánceres indolentes. Existen cada vez más un número mayor de publicaciones sobre cómo los polimorfismos de nucleótido simple (SNP) se relacionan con la susceptibilidad al cáncer de próstata o predecir con mayor precisión qué grado de agresividad adquiere la enfermedad. Se presenta una revisión bibliográfica de las investigaciones publicadas en PubMed desde el año 2000 hasta el 2012 que ponen de manifiesto la relación de los SNP con el riesgo a padecer cáncer de próstata y con sus características anatomopatológicas.

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Arbuscular mycorrhizal fungi (AMF) are important symbionts of plants that improve plant nutrient acquisition and promote plant diversity. Although within-species genetic differences among AMF have been shown to differentially affect plant growth, very little is actually known about the degree of genetic diversity in AMF populations. This is largely because of difficulties in isolation and cultivation of the fungi in a clean system allowing reliable genotyping to be performed. A population of the arbuscular mycorrhizal fungus Glomus intraradices growing in an in vitro cultivation system was studied using newly developed simple sequence repeat (SSR), nuclear gene intron and mitochondrial ribosomal gene intron markers. The markers revealed a strong differentiation at the nuclear and mitochondrial level among isolates. Genotypes were nonrandomly distributed among four plots showing genetic subdivisions in the field. Meanwhile, identical genotypes were found in geographically distant locations. AMF genotypes showed significant preferences to different host plant species (Glycine max, Helianthus annuus and Allium porrum) used before the fungal in vitro culture establishment. Host plants in a field could provide a heterogeneous environment favouring certain genotypes. Such preferences may partly explain within-population patterns of genetic diversity.

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We have defined structural features that are apparently important for the binding of four different, unrelated antigenic epitopes to the same major histocompatibility complex (MHC) class I molecule, H-2Kd. The four epitopes are recognized in the form of synthetic peptides by cytotoxic T lymphocytes of the appropriate specificity. By analysis of the relative potency of truncated peptides, we demonstrated that for each of the four epitopes, optimal antigenic activity was present in a peptide of 9 or 10 amino acid residues. A comparison of the relative competitor activity of the different-length peptides in a functional competition assay, as well as in a direct binding assay based on photoaffinity labeling of the Kd molecule, indicated that the enhanced potency of the peptides upon reduction in length was most likely due to a higher affinity of the shorter peptides for the Kd molecule. A remarkably simple motif that appears to be important for the specific binding of Kd-restricted peptides was identified by the analysis of peptides containing amino acid substitutions or deletions. The motif consists of two elements, a Tyr in the second position relative to the NH2 terminus and a hydrophobic residue with a large aliphatic side chain (Leu, Ile, or Val) at the COOH-terminal end of the optimal 9- or 10-mer peptides. We demonstrated that a simple peptide analogue (AYP6L) that incorporates the motif can effectively and specifically interact with the Kd molecule. Moreover, all of the additional Kd-restricted epitopes defined thus far in the literature contain the motif, and it may thus be useful for the prediction of new epitopes recognized by T cells in the context of this MHC class I molecule.

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In Arabidopsis thaliana, gene expression level polymorphisms (ELPs) between natural accessions that exhibit simple, single locus inheritance are promising quantitative trait locus (QTL) candidates to explain phenotypic variability. It is assumed that such ELPs overwhelmingly represent regulatory element polymorphisms. However, comprehensive genome-wide analyses linking expression level, regulatory sequence and gene structure variation are missing, preventing definite verification of this assumption. Here, we analyzed ELPs observed between the Eil-0 and Lc-0 accessions. Compared with non-variable controls, 5' regulatory sequence variation in the corresponding genes is indeed increased. However, approximately 42% of all the ELP genes also carry major transcription unit deletions in one parent as revealed by genome tiling arrays, representing a &gt;4-fold enrichment over controls. Within the subset of ELPs with simple inheritance, this proportion is even higher and deletions are generally more severe. Similar results were obtained from analyses of the Bay-0 and Sha accessions, using alternative technical approaches. Collectively, our results suggest that drastic structural changes are a major cause for ELPs with simple inheritance, corroborating experimentally observed indel preponderance in cloned Arabidopsis QTL.