98 research outputs found

    XMM-Newton observations of Extremely Red Objects and the link with luminous, X-ray obscured Quasars

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    We present the results of a deep (about 80 ks) XMM-Newton survey of the largest sample of near-infrared selected Extremely Red Objects (R-K>5) available to date to K_S< 19.2. At the relatively bright X-ray fluxes (F_{2-10 keV}> 4x10^{-15} cgs) and near-infrared magnitude probed by the present observations, the fraction of AGN (i.e., X-ray detected) among the ERO population is small (~3.5%); conversely, the fraction of EROs among hard X-ray selected sources is much higher (~20%). The X-ray properties of EROs detected in our XMM-Newton observation indicate absorption in excess of 10^{22} cm^{-2} in a large fraction of them. We have also considered additional samples of X-ray detected EROs available in the literature. X-ray spectral analysis of the highest S/N sources unambiguously indicates that large columns of cold gas (even >10^{23} cm^{-2}) are the rule rather than the exception. The X-ray, optical, and near-infrared properties of those X-ray selected EROs with a spectroscopic or photometric redshift nicely match those expected for quasars 2, the high-luminosity, high-redshift obscured AGNs predicted in baseline XRB synthesis models. A close correlation is detected between X- and K-band fluxes. For the AGN EROs this is consistent, under reasonable assumptions, with the relation established locally between the host galaxies and their central black holes. This suggest that the majority of EROs are powered by massive black holes accreting, on average, at about 0.03-0.1 of the Eddington limit.Comment: 33 pages, 10 figures, to appear in A&

    Obesity and poor breast cancer prognosis: an illusion because of hormone replacement therapy?

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    High body mass index (BMI) and use of hormone replacement therapy (HRT) increase the risk of postmenopausal breast cancer. It has been shown that BMI modifies the effect of HRT, as its influence is most pronounced in lean women. We investigated the influence of BMI and HRT on prognosis in 2640 postmenopausal women diagnosed with breast cancer in Sweden in 1993–1995, taking into account HRT and mammography before diagnosis. Logistic and Cox regression were used. In non-users of HRT, obese women (BMI >30) compared with normal weight women (BMI <25) had a similar prognosis (hazard ratio (HR) 1.1, 95% confidence interval (CI) 0.8–1.6), despite larger tumours found in obese women. Obese HRT users had less favourable tumour characteristics and poorer prognosis compared with normal weight women (HR 3.7, 95% CI 1.9–7.2). The influence of BMI on breast cancer prognosis was similar whether diagnosed by mammographic screening or not. We found a similar prognosis of postmenopausal breast cancer-specific death regardless of BMI in non-users of HRT, but among HRT users obesity was associated with a poorer breast cancer prognosis

    Development and evaluation of a tool for the assessment of footwear characteristics

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    <p>Abstract</p> <p>Background</p> <p>Footwear characteristics have been linked to falls in older adults and children, and the development of many musculoskeletal conditions. Due to the relationship between footwear and pathology, health professionals have a responsibility to consider footwear characteristics in the etiology and treatment of various patient presentations. In order for health professionals and researchers to accurately and efficiently critique an individual's footwear, a valid and reliable footwear assessment tool is required. The aim of this study was to develop a simple, efficient, and reliable footwear assessment tool potentially suitable for use in a range of patient populations.</p> <p>Methods</p> <p>Consideration of previously published tools, other footwear related literature, and clinical considerations of three therapists were used to assist in the development of the tool. The tool was developed to cover fit, general features, general structure, motion control properties, cushioning, and wear patterns. A total of 15 participants (who provided two pairs of shoes each) were recruited, and assessment using the scale was completed on two separate occasions (separated by 1 – 3 weeks) by a physiotherapist and a podiatrist on each participant's dominant foot. Intra-rater and inter-rater reliability were evaluated using intra-class correlation coefficients (ICCs) (model 2, 1) and the 95% limits of agreement (95% LOAs) for continuous items, and percentage agreement and kappa (κ) statistics for categorical items.</p> <p>Results</p> <p>All categorical items demonstrated high percentage agreement statistic for intra-rater (83 – 100%) and inter-rater (83 – 100%) comparisons. With the exception of last shape and objective measures used to categorise the adequacy of length, excellent intra-rater (ICC = 0.91 – 1.00) and inter-rater reliability (ICC = 0.90 – 1.00) was indicated for continuous items in the tool, including the motion control properties scale (0.91 – 0.95).</p> <p>Conclusion</p> <p>A comprehensive footwear assessment tool with good face validity has been developed to assist future research and clinical footwear assessment. Generally good reliability amongst all items indicates that the tool can be used with confidence in research and clinical settings. Further research is now required to determine the clinical validity of each item in various patient populations.</p

    Genome Scan of M. tuberculosis Infection and Disease in Ugandans

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    Tuberculosis (TB), caused by Mycobacterium tuberculosis (Mtb), is an enduring public health problem globally, particularly in sub-Saharan Africa. Several studies have suggested a role for host genetic susceptibility in increased risk for TB but results across studies have been equivocal. As part of a household contact study of Mtb infection and disease in Kampala, Uganda, we have taken a unique approach to the study of genetic susceptibility to TB, by studying three phenotypes. First, we analyzed culture confirmed TB disease compared to latent Mtb infection (LTBI) or lack of Mtb infection. Second, we analyzed resistance to Mtb infection in the face of continuous exposure, defined by a persistently negative tuberculin skin test (PTST-); this outcome was contrasted to LTBI. Third, we analyzed an intermediate phenotype, tumor necrosis factor-alpha (TNFα) expression in response to soluble Mtb ligands enriched with molecules secreted from Mtb (culture filtrate). We conducted a full microsatellite genome scan, using genotypes generated by the Center for Medical Genetics at Marshfield. Multipoint model-free linkage analysis was conducted using an extension of the Haseman-Elston regression model that includes half sibling pairs, and HIV status was included as a covariate in the model. The analysis included 803 individuals from 193 pedigrees, comprising 258 full sibling pairs and 175 half sibling pairs. Suggestive linkage (p<10−3) was observed on chromosomes 2q21-2q24 and 5p13-5q22 for PTST-, and on chromosome 7p22-7p21 for TB; these findings for PTST- are novel and the chromosome 7 region contains the IL6 gene. In addition, we replicated recent linkage findings on chromosome 20q13 for TB (p = 0.002). We also observed linkage at the nominal α = 0.05 threshold to a number of promising candidate genes, SLC11A1 (PTST- p = 0.02), IL-1 complex (TB p = 0.01), IL12BR2 (TNFα p = 0.006), IL12A (TB p = 0.02) and IFNGR2 (TNFα p = 0.002). These results confirm not only that genetic factors influence the interaction between humans and Mtb but more importantly that they differ according to the outcome of that interaction: exposure but no infection, infection without progression to disease, or progression of infection to disease. Many of the genetic factors for each of these stages are part of the innate immune system

    Androgen receptor expresion in breast cancer: Relationship with clinicopathological characteristics of the tumors, prognosis, and expression of metalloproteases and their inhibitors

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    <p>Abstract</p> <p>Background</p> <p>In the present study we analyze, in patients with breast cancer, the tumor expression of androgen receptors (AR), its relationship with clinicopathological characteristics and with the expression of several matrix metalloproteases (MMPs) and their inhibitors (TIMPs), as well as with prognosis.</p> <p>Methods</p> <p>An immunohistochemical study was performed using tissue microarrays and specific antibodies against AR, MMPs -1, -2, -7, -9, -11, -13, -14, and TIMPs -1, -2 and -3. More than 2,800 determinations on tumor specimens from 111 patients with primary invasive ductal carcinoma of the breast (52 with axillary lymph node metastases and 59 without them) and controls were performed. Staining results were categorized using a score based on the intensity of the staining and a specific software program calculated the percentage of immunostained cells automatically.</p> <p>Results</p> <p>A total of 83 cases (74.8%) showed a positive immunostaining for AR, but with a wide variation in the staining score values. There were no significant associations between the total immunostaining scores for AR and any clinicopathological parameters. However, score values for MMP-1, -7 and -13, were significantly higher in AR-positive tumors than in AR-negative tumors. Likewise, when we considered the cellular type expressing each factor, we found that AR-positive tumors had a higher percentage of cases positive for MMP-1, -7, -11, and TIMP-2 in their malignant cells, as well as for MMP-1 in intratumoral fibroblasts. On the other hand, multivariate analysis demonstrated that patients with AR-positive tumors have a significant longer overall survival than those with AR-negative breast carcinomas (<it>p </it>= 0.03).</p> <p>Conclusion</p> <p>Our results confirm that AR are commonly expressed in breast cancer, and are correlated with the expression of some MMPs and TIMP-2. Although we found a specific value of AR expression to be a prognostic indicator in breast cancer, the functional role of AR in these neoplasms is still unclear and further data are needed in order to clarify their biological signification in breast cancer.</p

    Pecking order theory versus trade-off theory : are service SMEs’ capital structure decisions different?

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    This paper seeks to analyse if the capital structure decisions of service small and medium-sized enterprises (SMEs) are different from those of other types of firm. To do so, we consider four research samples: (i) 610 service SMEs; (ii) 126 service large firms; (iii) 679 manufacturing and construction SMEs; and (iv) 132 manufacturing and construction large firms. Using the two-step estimation method, the empirical evidence obtained in this study shows that the capital structure decisions of service SMEs are different from those of other types of firm. Service SMEs’ capital structure decisions are closer to the assumptions of Pecking Order Theory and further removed from those of Trade-Off Theory compared with the case of other types of firm

    The potential role for prolactin-inducible protein (PIP) as a marker of human breast cancer micrometastasis

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    The prolactin-inducible protein (PIP/GCPD15) is believed to originate from a limited set of tissues, including breast and salivary glands, and has been applied as a clinical marker for the diagnosis of metastatic tumours of unknown origin. We have investigated the potential role of PIP mRNA as a marker of human breast cancer metastasis. Using reverse transcription polymerase chain reaction and Southern or dot blot analysis, PIP mRNA was detected in 4/6 breast cell lines, independent of oestrogen receptor (ER) status. In breast primary tumours (n = 97), analysed from histologically characterized sections, PIP mRNA was detected in most cases. Higher PIP mRNA levels correlated with ER+ (P = 0.0004), progesterone receptor positive (PR+) (P = 0.0167), low-grade (P = 0.0195) tumours, and also PIP protein levels assessed by immunohistochemistry (n = 19, P = 0.0319). PIP mRNA expression was also detectable in 11/16 (69%) of axillary node metastases. PIP mRNA expression, however, was also detected in normal breast duct epithelium, skin, salivary gland and peripheral blood leucocyte samples from normal individuals. We conclude that PIP mRNA is frequently expressed in both primary human breast tumours and nodal metastases. However, the presence of PIP expression in skin creates a potential source of contamination in venepuncture samples that should be considered in its application as a marker for breast tumour micrometastases. © 1999 Cancer Research Campaig

    Hemolymph microbiome of Pacific oysters in response to temperature, temperature stress and infection

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    Microbiota provide their hosts with a range of beneficial services, including defense from external pathogens. However, host-associated microbial communities themselves can act as a source of opportunistic pathogens depending on the environment. Marine poikilotherms and their microbiota are strongly influenced by temperature, but experimental studies exploring how temperature affects the interactions between both parties are rare. To assess the effects of temperature, temperature stress and infection on diversity, composition and dynamics of the hemolymph microbiota of Pacific oysters (Crassostrea gigas), we conducted an experiment in a fully-crossed, three-factorial design, in which the temperature acclimated oysters (8 or 22 °C) were exposed to temperature stress and to experimental challenge with a virulent Vibrio sp. Strain. We monitored oyster survival and repeatedly collected hemolymph of dead and alive animals to determine the microbiome composition by 16s rRNA gene amplicon pyrosequencing. We found that the microbial dynamics and composition of communities in healthy animals (including infection survivors) were significantly affected by temperature and temperature stress, but not by infection. The response was mediated by changes in the incidence and abundance of operational taxonomic units (OTUs) and accompanied by little change at higher taxonomic levels, indicating dynamic stability of the hemolymph microbiome. Dead and moribund oysters, on the contrary, displayed signs of community structure disruption, characterized by very low diversity and proliferation of few OTUs. We can therefore link short-term responses of host-associated microbial communities to abiotic and biotic factors and assess the potential feedback between microbiota dynamics and host survival during disease
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