2,104 research outputs found

    Differences in neurocognitive aspects of dyslexia in Dutch and immigrant 6-7- and 8-9-years old children

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    Detecting dyslexia in immigrant children can be jeopardized because of assessment bias, as a consequence of a limited word lexicon or differences in language development of these children. This is in contrast with the view of the universal neurocognitive basis for dyslexia. In this research, differences in screening children at risk for dyslexia with the Dyslexia Screening Test (DST) were studied in third and fifth graders of primary school of Dutch (mainstream) and immigrant descent. Mean group differences were found on a few subtests (Naming Letters, Semantic Fluency, Backward Digit Span and Verbal Fluency), probably as a consequence of bias because of the linguistic character of these subtests. The raw scores of word lexicon increased in the Dutch and immigrant group. The association of having a dyslexia diagnosis on DST scores was comparable for Dutch and immigrant children. Differences in the DST scores between non-dyslexic and dyslexic children were found between the third and fifth grade, with a stronger effect of having a dyslexia diagnosis in the fifth grade than the third grade, for Dutch as well as immigrant children. Screening of dyslexia seems easier in the fifth grade than in the third grade, dyslexic children show a slower reading development than their non-dyslexic peers, irrespective of their cultural background. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s40064-015-0874-1) contains supplementary material, which is available to authorized users

    Broadband hyperspectral imaging for breast tumor detection using spectral and spatial information

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    Complete tumor removal during breast-conserving surgery remains challenging due to the lack of optimal intraoperative margin assessment techniques. Here, we use hyperspectral imaging for tumor detection in fresh breast tissue. We evaluated different wavelength ranges and two classification algorithms; a pixel-wise classification algorithm and a convolutional neural network that combines spectral and spatial information. The highest classification performance was obtained using the full wavelength range (450-1650nm). Adding spatial information mainly improved the differentiation of tissue classes within the malignant and healthy classes. High sensitivity and specificity were accomplished, which offers potential for hyperspectral imaging as a margin assessment technique to improve surgical outcome. (C) 2019 Optical Society of America under the terms of the OSA Open Access Publishing Agreemen

    Loss of Bcl-2 in invasive breast cancer is associated with high rates of cell death, but also with increased proliferative activity.

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    Bcl-2 has been demonstrated to inhibit apoptosis in breast cancer cells in vitro, and the ratio between Bcl-2 and its proapoptotic homologue Bax seems to be an important determinant of cellular sensitivity to induction of apoptosis. However, little information is available on the relationship between Bcl-2 and the rate of apoptotic and necrotic cell death in breast tumours. From a series of 441 premenopausal, lymphnode-negative breast cancer patients, a subset of 49 tumours was selected in which immunostaining for the 26-kDa isoform of Bcl-2 was either absent (n = 23) or very high (n = 26). High expression of Bcl-2 was found to be strongly associated with low rates of apoptotic (P < 0.001) and necrotic cell death (P < 0.001). The mean value of the apoptotic index was 2.69%+/-1.40% in Bcl-2-negative tumours and 0.68%+/-1.00% in Bcl-2-positive tumours. Expression of the proapoptotic protein Bax correlated neither with Bcl-2 nor with the frequency of apoptotic cells. Immunostaining for the antiapoptotic Bcl-2 homologue BcI-X(L) correlated with Bcl-2 expression (P < 0.001) but not with apoptosis. High proliferation rate and high tumour grade (Bloom-Richardson) were strongly associated with absence of Bcl-2 expression (P< 0.001). p53 accumulation was associated with absence of Bcl-2 expression and increased apoptotic activity. Loss of Bcl-2 expression was strongly correlated with increased apoptotic and necrotic cell death, high proliferation rate and high tumour grade, supporting a model in which Bcl-2 not only mediates cell death, but also cell division in breast cancer tissue, and in which regulation of cell division and cell death are tightly linked

    Loss of heterozygosity for defined regions on chromosomes 3, 11 and 17 in carcinomas of the uterine cervix.

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    Loss of heterozygosity (LOH) frequently occurs in squamous cell carcinomas of the uterine cervix and indicates the probable sites of tumour-suppressor genes that play a role in the development of this tumour. To define the localization of these tumour-suppressor genes, we studied loss of heterozygosity in 64 invasive cervical carcinomas (stage IB and IIA) using the polymerase chain reaction with 24 primers for polymorphic repeats of known chromosomal localization. Chromosomes 3, 11, 13, 16 and 17, in particular, were studied. LOH was frequently found on chromosome 11, in particular at 11q22 (46%) and 11q23.3 (43%). LOH on chromosome 11p was not frequent. On chromosome 17p13.3, a marker (D17S513) distal to p53 showed 38% LOH, whereas p53 itself showed only 20% LOH. On the short arm of chromosome 3, LOH was frequently found (41%) at 3p21.1. The beta-catenin gene is located in this chromosomal region. Therefore, expression of beta-catenin protein was studied in 39 cases using immunohistochemistry. Staining of beta-catenin at the plasma membrane of tumour cells was present in 38 cases and completely absent in only one case. The tumour-suppressor gene on chromosome 3p21.1 may be beta-catenin in this one case, but (an)other tumour-suppressor gene(s) must also be present in this region. For the other chromosomes studied, 13q (BRCA-2) and 16q (E-cadherin), only sporadic losses (< 15% of cases) were found. Expression of E-cadherin was found in all of 37 cases but in six cases the staining was very weak. No correlation was found between clinical and histological parameters and losses on chromosome 3p, 11q and 17p. In addition to LOH, microsatellite instability was found in one tumour for almost all loci and in eight tumours for one to three loci. In conclusion, we have identified three loci with frequent LOH, which may harbour new tumour-suppressor genes, and found microsatellite instability in 14% of cervical carcinomas

    Method for coregistration of optical measurements of breast tissue with histopathology : the importance of accounting for tissue deformations

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    For the validation of optical diagnostic technologies, experimental results need to be benchmarked against the gold standard. Currently, the gold standard for tissue characterization is assessment of hematoxylin and eosin (H&E)-stained sections by a pathologist. When processing tissue into H&E sections, the shape of the tissue deforms with respect to the initial shape when it was optically measured. We demonstrate the importance of accounting for these tissue deformations when correlating optical measurement with routinely acquired histopathology. We propose a method to register the tissue in the H&E sections to the optical measurements, which corrects for these tissue deformations. We compare the registered H&E sections to H&E sections that were registered with an algorithm that does not account for tissue deformations by evaluating both the shape and the composition of the tissue and using microcomputer tomography data as an independent measure. The proposed method, which did account for tissue deformations, was more accurate than the method that did not account for tissue deformations. These results emphasize the need for a registration method that accounts for tissue deformations, such as the method presented in this study, which can aid in validating optical techniques for clinical use. (C) The Authors. Published by SPIE under a Creative Commons Attribution 4.0 Unported License

    Immunohistochemical categorisation of ductal carcinoma in situ of the breast

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    The aim of this study is to analyse whether immunohistochemistry (IHC) applying a broad set of markers could be used to categorise ductal carcinoma in situ (DCIS) of the breast in distinct subgroups corresponding to the recently defined molecular categories of invasive carcinoma. Immunohistochemistry of pure DCIS cases constructed in tissue arrays was performed with 16 markers (oestrogen receptor (ER), progesterone receptor (PR), androgen receptor (AR), Bcl-2, p53, Her2, insulin-like growth factor receptor, E-cadherin, epithelial membrane antigen (EMA), CA125, keratins 5/6, 14, 19, epidermal growth factor receptor, S100, and CD31). Results in 163 cases were analysed by unsupervised hierarchical clustering. Histological classification was performed by review of whole tissue sections and identified 36 well-, 55 intermediately, and 72 poorly differentiated DCISs. Unsupervised hierarchical cluster analysis categorised DCIS into two major groups that could be further subdivided into subgroups based on the expression of six markers (ER, PR, AR, Bcl-2, p53, and Her2). In the major predominantly ER/Bcl-2-positive (luminal) group, three subgroups (AR-positive (n=33), AR-negative (n=40), and mixed (n=34)) could be identified and included 34 well-differentiated DCISs. Within the major predominantly ER/Bcl-2-negative (nonluminal) group, a Her2-positive subgroup (n=34) was characterised by 31 poorly differentiated lesions. Eight triple-negative lesions, including one positive for keratin 5/6 and two positive for p53, were encountered. Intermediately differentiated DCIS shared a comparable IHC staining pattern with well-differentiated DCIS that was distinct from poorly differentiated DCIS (P<0.001). Ductal carcinoma in situ could be categorised by IHC into two major groups and five subgroups using six markers. Morphologically, intermediately differentiated DCIS seems to have more biological similarities with well-differentiated lesions as compared to poorly differentiated lesions

    Effects of organically and conventionally produced feed on biomarkers of health in a chicken model

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    Consumers expect organic products to be healthier. However, limited research has been performed to study the effect of organic food on health. The present study aimed to identify biomarkers of health to enable future studies in human subjects. A feeding experiment was performed in two generations of three groups of chickens differing in immune responsiveness, which were fed identically composed feeds from either organic or conventional produce. The animals of the second generation were exposed to an immune challenge and sacrificed at 13 weeks of age. Feed and ingredients were analysed on macro- and micronutrients, i.e. vitamins, minerals, trace elements, heavy metals and microbes. The chickens were studied by general health and immune parameters, metabolomics, genomics and post-mortem evaluation. The organic and conventional feeds were comparable with respect to metabolisable energy. On average, the conventionally produced feeds had a 10 % higher protein content and some differences in micronutrients were observed. Although animals on both feeds were healthy, differences between the groups were found. The random control group of chickens fed conventional feed showed overall a higher weight gain during life span than the group on organic feed, although feed intake was mostly comparable. The animals on organic feed showed an enhanced immune reactivity, a stronger reaction to the immune challenge as well as a slightly stronger ‘catch-up growth’ after the challenge. Biomarkers for future research were identified in the parameters feed intake, body weight and growth rate, and in immunological, physiological and metabolic parameters, several of these differing most pronounced after the challeng

    Acquiescence and Extremity in Cross-National Surveys: Domain Dependence and Country-Level Correlates

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    Likert-type rating scales are susceptible to response styles, such as acquiescence and extremity scoring. Although it is widely acknowledged that response styles can seriously invalidate findings of cross-cultural research, their theoretical underpinnings are hardly explored. The current study analyzed domain-dependency and country differences in acquiescence and extremity scoring in a large dataset of the International Social Survey Program. The hypothesis that response styles are more likely in domains with a high personal relevance compared to domains with a low personal relevance was tentatively confirmed. Correlations with various cultural, psychological, and economic variables were investigated. We found that acquiescence was negatively related to affluence, individualism, and well-being, while extremity was only negatively related to well-being. Positive associations were found between uncertainty avoidance and both acquiescence and extremity

    An item and construct bias analysis of two language versions of a verbal analogies scale

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    The Woodcock Muñoz Language Survey is a test of cognitive academic language proficiency that has been adapted from English into Xhosa by a South African team of researchers. This study was primarily concerned with the Verbal Analogies Scale of the Woodcock Muñoz Language Survey and aimed to extend previous research on the equivalence of the two language versions of the scale. The study employed a monolingual two-group design consisting of 150 mainly English-speaking and 149 mainly Xhosa learners in Grades 6 and 7. The first research objective was to investigate item bias (or differential item functioning items) in the Visual Analogies Scale across the Xhosa and English versions using logistic regression and Mantel–Haenszel statistical techniques. Five items were identified as differential item functioning. The second objective was to evaluate the construct equivalence of the two versions by conducting a factor analysis after removing the differential item functioning items from the scale. Two factors were identified. The first factor displayed significant loadings across both language versions. The second factor was stable for the English version but not for the Xhosa version. Results were supported by calculating a Tucker’s phi coefficient for both factors. It was therefore concluded that Factor 1 is structurally equivalent across the two language versions but that Factor 2 was not structurally equivalent. Thus, the detection and removal of differential item functioning items did not result in structural equivalence.Department of HE and Training approved lis

    Expression of Bcl-2 in node-negative breast cancer is associated with various prognostic factors, but does not predict response to one course of perioperative chemotherapy.

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    The aim of this study was to assess relationships between Bcl-2 expression, response to chemotherapy and a number of pathological and biological tumour parameters in premenopausal, lymph node-negative breast cancer patients. Expression of Bcl-2 was determined using immunohistochemistry on paraffin-embedded sections in a series of 441 premenopausal, lymph node-negative breast cancers of patients randomised to receive perioperative chemotherapy (5-fluorouracil, doxorubicin, cyclophosphamide) or no perioperative chemotherapy. Immunohistochemistry of Bcl-2 was evaluated by scoring both staining intensity (0-3) and number of positive cells (0-2). Using these scores tumours were grouped into categories 0-6. It was found that 9.2% of the tumours were completely negative (0), 17.2% weakly (1 + 2), 41.6% moderately (3 + 4) and 31.9% strongly positive (5 + 6) for Bcl-2. A positive correlation was found between high Bcl-2 expression and oestrogen (P < 0.001) and progesterone receptor positivity (P < 0.001) and low tumour grade (P < 0.001), whereas high Bcl-2 expression was negatively correlated with p53 (P < 0.001) and c-erb-B-2 positively (P < 0.001), high Ki-67 index (P < 0.001), mitotic index (P < 0.001) and large tumour size (P = 0.006). Patients with tumours expressing high levels of Bcl-2 (overall score 3-6) had a significantly better disease-free (P = 0.004) and overall (P = 0.009) survival. However, in a multivariate model this association no longer remained significant. There was a trend for an effect of adjuvant chemotherapy on disease-free survival both for patients with Bcl-2-positive (HR-0.61, 95% CI 0.35-1.06, P = 0.07) and negative (HR = 0.55, 95% CI 0.27-1.12, P = 0.09) breast tumours at a median follow-up of 49 months. The level of Bcl-2 expression does not seem to predict response to perioperative chemotherapy in premenopausal, lymph node-negative breast cancer patients. High levels of Bcl-2 are preferentially expressed in well-differentiated tumours and are associated with favourable prognosis. However, Bcl-2 expression is not an independent prognostic factor in this patient series
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