395 research outputs found

    A novel diffuse gastric cancer susceptibility variant in E-cadherin (CDH1) intron 2: A case control study in an Italian population

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    <p>Abstract</p> <p>Background</p> <p>Inherited genetic factors such as E-cadherin (<it>CDH1</it>) promoter variants are believed to influence the risk towards sporadic diffuse gastric cancer (DGC). Recently, a new regulatory region essential for <it>CDH1 </it>transcription has been identified in <it>CDH1 </it>intron 2.</p> <p>Methods</p> <p>We genotyped all known polymorphisms located within conserved sequences of <it>CDH1 </it>intron 2 (rs10673765, rs9932686, rs1125557, rs9282650, rs9931853) in an Italian population consisting of 134 DGC cases and 100 healthy controls (55 patient relatives and 45 unrelated, matched individuals). The influence of individual variants on DGC risk was assessed using χ<sup>2</sup>-tests and logistic regression. The relative contribution of alleles was estimated by haplotype analysis.</p> <p>Results</p> <p>We observed a significant (p < 0.0004) association of the <it>CDH1 </it>163+37235G>A variant (rs1125557) with DGC risk. Odds ratios were 4.55 (95%CI = 2.09–9.93) and 1.38 (95%CI = 0.75–2.55) for AA and GA carriers, respectively. When adjusted for age, sex, smoking status, alcohol intake and <it>H. pylori </it>infection, the risk estimates remained largely significant for AA carriers. Haplotype analysis suggested the 163+37235A-allele contributes to disease risk independently of the other variants studied.</p> <p>Conclusion</p> <p>The <it>CDH1 </it>163+37235G>A polymorphism may represent a novel susceptibility variant for sporadic DGC if confirmed in other populations. Considering the broad expression of E-cadherin in epithelia, this exploratory study encourages further evaluation of the 163+37235A-allele as a susceptibility variant in other carcinomas.</p

    Use and limitations of malaria rapid diagnostic testing by community health workers in war-torn Democratic Republic of Congo

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    <p>Abstract</p> <p>Background</p> <p>Accurate and practical malaria diagnostics, such as immunochromatographic rapid diagnostic tests (RDTs), have the potential to avert unnecessary treatments and save lives. Volunteer community health workers (CHWs) represent a potentially valuable human resource for expanding this technology to where it is most needed, remote rural communities in sub-Saharan Africa with limited health facilities and personnel. This study reports on a training programme for CHWs to incorporate RDTs into their management strategy for febrile children in the Democratic Republic of Congo, a tropical African setting ravaged by human conflict.</p> <p>Methods</p> <p>Prospective cohort study, satisfaction questionnaire and decision analysis.</p> <p>Results</p> <p>Twelve CHWs were trained to safely and accurately perform and interpret RDTs, then successfully implemented rapid diagnostic testing in their remote community in a cohort of 357 febrile children. CHWs were uniformly positive in evaluating RDTs for their utility and ease of use. However, high malaria prevalence in this cohort (93% by RDTs, 88% by light microscopy) limited the cost-effectiveness of RDTs compared to presumptive treatment of all febrile children, as evidenced by findings from a simplified decision analysis.</p> <p>Conclusions</p> <p>CHWs can safely and effectively use RDTs in their management of febrile children; however, cost-effectiveness of RDTs is limited in zones of high malaria prevalence.</p

    CMV infection of liver transplant recipients: comparison of antigenemia and molecular biology assays

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    BACKGROUND: CMV is a major clinical problem in transplant recipients. Thus, it is important to use sensitive and specific diagnostic techniques to rapidly and accurately detect CMV infection and identify patients at risk of developing CMV disease. In the present study, CMV infection after liver transplantation was monitored retrospectively by two molecular biology assays - a quantitative PCR assay and a qualitative NASBA assay. The results were compared with those obtained by prospective pp65 antigenemia determinations. MATERIALS AND METHODS: 87 consecutive samples from 10 liver transplanted patients were tested for CMV by pp65 antigenemia, and CMV monitor and NASBA pp67 mRNA assay. RESULTS: CMV infection was detected in all patients by antigenemia and CMV monitor, whereas NASBA assay identified only 8/10 patients with viremia. Furthermore, CMV infection was never detected earlier by molecular biology assays than by antigenemia. Only 5/10 patients with CMV infection developed CMV disease. Using a cut off value of 8 cells/50,000, antigenemia was found to be the assay that better identified patients at risk of developing CMV disease. However, the kinetics of the onset of infection detected by NASBA and CMV monitor seemed to have better identified patients at risk of developing CMV disease. Furthermore, before onset of disease, CMV pp67 mRNA was found to have similar or better negative and positive predictive values for the development of CMV disease. CONCLUSIONS: The present data, suggests that the concomitant use of antigenemia and pp67 mRNA assay gives the best identification of patients at risk of developing CMV disease

    Thermal modification of wood and a complex study of its properties by magnetic resonance and other methods

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    © 2016, Springer-Verlag Berlin Heidelberg.Thermal modification of wood is an effective method to improve some of the properties of wood. It is reported on studies of vacuum thermal-treated wood species by magnetic resonance methods. Wood species such as Scots pine (Pinus sylvestris), birch (Betula pendula), Russian larch (Larix sibirica), Norway spruce (Picea abies), small-leaved lime (Tilia cordata) were vacuum treated by heat at 220 °C with various durations up to 8 h. This selection of wood species was investigated by electron paramagnetic resonance, nuclear magnetic resonance and microscopy methods before and after the thermal treatment. Electron paramagnetic resonance experiments revealed changes in the amount of free radicals in samples with the thermal treatment duration. Additional information on magnetic relaxation of 1H nuclei in samples at room temperature was obtained. Optical microscope analysis helped to detect structural changes in the thermally modified wood. Important properties of wood such as wood hardness and humidity absorption were also studied. The original results that were obtained correlate and complement each other, and clarify changes in the wood structure that appear with the heat treatment

    Long Term Follow-Up of the Endovascular Trans-Vessel Wall Technique for Parenchymal Access in Rabbit with Full Clinical Integration

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    OBJECTIVE: Endovascular techniques are providing options to surgical/percutaneous cell transplantation methods. Some cells, e.g. insulin producing cells, are not suitable for intra-luminal transplantation and for such cells, other options must be found. We have constructed a "nanocatheter" with a penetrating tip for vessel perforation, thereby creating a working channel for parenchymal access by endovascular technique. To finish the procedure safely, the distal tip is detached to provide a securing plug in the vessel wall defect. MATERIALS AND METHODS: We have performed interventions with full clinical integration in the superior mesenteric artery (SMA), the subclavian artery and the external carotid artery in rabbits. No hemorrhagic- or thromboembolic events occurred during the procedure. Stenosis formation and distal embolisation were analyzed by angiography and macroscopic inspection during autopsy at five, 30 and 80 days. All animals and implanted devices were also evaluated by micro-dissections and histochemical analysis. RESULTS: In this study we show safety data on the trans-vessel wall technique by behavioral, angiographical and histological analysis. No stenosis formation was observed at any of the follow-up time points. No animals or organs have shown any signs of distress due to the intervention. Histological examination showed no signs of hemorrhage, excellent biocompatibility with no inflammation and a very limited fibrous capsule formation around the device, comparable to titanium implants. Further, no histological changes were detected in the endothelia of the vessels subject to intervention. CONCLUSIONS: The trans-vessel wall technique can be applied for e.g. cell transplantations, local substance administration and tissue sampling with low risk for complications during the procedure and low risk for hemorrhage, stenosis development or adverse tissue reactions with an 80 days follow-up time. The benefit should be greatest in organs that are difficult or risky to reach with surgical techniques, such as the pancreas, the CNS and the heart

    Coherent Random Lasing Realized in Polymer Vesicles

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    We have demonstrated the realization of a coherent vesicle random lasing (VRL) from the dye doped azobenzene polymer vesicles self-assembled in the tetrahydrofuran-water system, which contains a double-walled structure: a hydrophilic and hydrophobic part. The effect of the dye and azobenzene polymer concentration on the threshold of random laser has been researched. The threshold of random laser decreases with an increase in the concentration of the pyrromethene 597 (PM597) laser and azobenzene polymer. Moreover, the scattering of small size group vesicles is attributed to providing a loop to boost the coherent random laser through the Fourier transform analysis. Due to the vesicles having the similar structure with the cell, the generation of coherent random lasers from vesicles expand random lasers to the biomedicine filed

    Reduced expression of a gene proliferation signature is associated with enhanced malignancy in colon cancer

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    The association between cell proliferation and the malignant potential of colon cancer is not well understood. Here, we evaluated this association using a colon-specific gene proliferation signature (GPS). The GPS was derived by combining gene expression data obtained from the analysis of a cancer cell line model and a published colon crypt profile. The GPS was overexpressed in both actively cycling cells in vitro and the proliferate compartment of colon crypts. K-means clustering was used to independantly stratify two cohorts of colon tumours into two groups with high and low GPS expression. Notably, we observed a significant association between reduced GPS expression and an increased likelihood of recurrence (P<0.05), leading to shorter disease-free survival in both cohorts. This finding was not a result of methodological bias as we verified the well-established association between breast cancer malignancy and increased proliferation, by applying our GPS to public breast cancer data. In this study, we show that reduced proliferation is a biological feature characterizing the majority of aggressive colon cancers. This contrasts with many other carcinomas such as breast cancer. Investigating the reasons underlying this unusual observation may provide important insight into the biology of colon cancer progression and putative novel therapy options

    Operational accuracy and comparative persistent antigenicity of HRP2 rapid diagnostic tests for Plasmodium falciparum malaria in a hyperendemic region of Uganda

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    BACKGROUND: Parasite-based diagnosis of malaria by microscopy requires laboratory skills that are generally unavailable at peripheral health facilities. Rapid diagnostic tests (RDTs) require less expertise, but accuracy under operational conditions has not been fully evaluated in Uganda. There are also concerns about RDTs that use the antigen histidine-rich protein 2 (HRP2) to detect Plasmodium falciparum, because this antigen can persist after effective treatment, giving false positive test results in the absence of infection. An assessment of the accuracy of Malaria Pf immuno-chromatographic test (ICT) and description of persistent antigenicity of HRP2 RDTs was undertaken in a hyperendemic area of Uganda. METHODS: Using a cross-sectional design, a total of 357 febrile patients of all ages were tested using ICT, and compared to microscopy as the gold standard reference. Two independent RDT readings were used to assess accuracy and inter-observer reliability. With a longitudinal design to describe persistent antigenicity of ICT and Paracheck, 224 children aged 6-59 months were followed up at 7-day intervals until the HRP2 antigens where undetectable by the RDTs. RESULTS: Of the 357 patients tested during the cross-sectional component, 40% (139) had positive blood smears for asexual forms of P. falciparum. ICT had an overall sensitivity of 98%, a specificity of 72%, a negative predictive value (NPV) of 98% and a positive predictive value (PPV) of 69%. ICT showed a high inter-observer reliability under operational conditions, with 95% of readings having assigned the same results (kappa statistics 0.921, p 50,000/microl, the mean duration of persistent antigenicity was 37 days compared to 26 days for parasitaemia less than 1,000/microl (log rank 21.9, p < 0.001). CONCLUSION: ICT is an accurate and appropriate test for operational use as a diagnostic tool where microscopy is unavailable. However, persistent antigenicity reduces the accuracy of this and other HRP2-based RDTs. The low specificity continues to be of concern, especially in children below five years of age. These pose limitations that need consideration, such as their use for diagnosis of patients returning with symptoms within two to four weeks of treatment. Good clinical skills are essential to interpret test results

    Assessment of cytomegalovirus-specific cell-mediated immunity for the prediction of cytomegalovirus disease in high-risk solid-organ transplant recipients: a multicenter cohort study.

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    BACKGROUND: Cytomegalovirus (CMV) disease remains an important problem in solid-organ transplant recipients, with the greatest risk among donor CMV-seropositive, recipient-seronegative (D(+)/R(-)) patients. CMV-specific cell-mediated immunity may be able to predict which patients will develop CMV disease. METHODS: We prospectively included D(+)/R(-) patients who received antiviral prophylaxis. We used the Quantiferon-CMV assay to measure interferon-γ levels following in vitro stimulation with CMV antigens. The test was performed at the end of prophylaxis and 1 and 2 months later. The primary outcome was the incidence of CMV disease at 12 months after transplant. We calculated positive and negative predictive values of the assay for protection from CMV disease. RESULTS: Overall, 28 of 127 (22%) patients developed CMV disease. Of 124 evaluable patients, 31 (25%) had a positive result, 81 (65.3%) had a negative result, and 12 (9.7%) had an indeterminate result (negative mitogen and CMV antigen) with the Quantiferon-CMV assay. At 12 months, patients with a positive result had a subsequent lower incidence of CMV disease than patients with a negative and an indeterminate result (6.4% vs 22.2% vs 58.3%, respectively; P &lt; .001). Positive and negative predictive values of the assay for protection from CMV disease were 0.90 (95% confidence interval [CI], .74-.98) and 0.27 (95% CI, .18-.37), respectively. CONCLUSIONS: This assay may be useful to predict if patients are at low, intermediate, or high risk for the development of subsequent CMV disease after prophylaxis. CLINICAL TRIALS REGISTRATION: NCT00817908
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