Identification, Characterization and Application of a G-Quadruplex Structured DNA Aptamer against Cancer Biomarker Protein Anterior Gradient Homolog 2

Background: Anterior gradient homolog 2 (AGR2) is a functional protein with critical roles in a diverse range of biological systems, including vertebrate tissue development, inflammatory tissue injury responses, and cancer progression. Clinical studies have shown that the AGR2 protein is overexpressed in a wide range of human cancers, including carcinomas of the esophagus, pancreas, breast, prostate, and lung, making the protein as a potential cancer biomarker. However, the general biochemical functions of AGR2 in human cells remain undefined, and the signaling mechanisms that drive AGR2 to inhibit p53 are still not clearly illustrated. Therefore, it is of great interest to develop molecular probes specifically recognizing AGR2 for its detection and for the elucidation of AGR2-associated molecular mechanism. Methodology/Principal Findings: Through a bead-based and flow cytometry monitored SELEX technology, we have identified a group of DNA aptamers that can specifically bind to AGR2 with K-d values in the nanomolar range after 14 rounds of selections. Aptamer C14B was chosen to further study, due to its high binding affinity and specificity. The optimized and shortened C14B1 has special G-rich characteristics, and the G-rich region of this binding motif was further characterized to reveal an intramolecular parallel G-quadruplex by CD spectroscopy and UV spectroscopy. Our experiments confirmed that the stability of the G-quadruplex structure was strongly dependent on the nature of the monovalent ions and the formation of G-quadruplex structure was also important for the binding capacity of C14B1 to the target. Furthermore, we have designed a kind of allosteric molecule beacon (aMB) probe for selective and sensitive detection of AGR2. Conclusion/Significance: In this work, we have developed new aptamer probes for specific recognition of the AGR2. Structural study have identified that the binding motif of aptamer is an intramolecular parallel G-quadruplex structure and its structure and binding affinity are strongly dependent on the nature of the monovalent ion. Furthermore, with our design of AGR2-aMB, AGR2 could be sensitively and selectively detected. This aptamer probe has great potential to serve as a useful tool for early diagnosis and prognosis of cancer and for fundamental research to elucidate the biochemical functions of AGR2.National Basic Research Program of China [2010CB732402]; National Instrumentation Program [2011YQ03012412]; Natural Science Foundation of Fujian Province for Distinguished Young Scholars [2010 J06004]; National Found for Fostering Talents of Basic Science [J1030415

QTL Detection for Kernel Size and Weight in Bread Wheat (Triticum aestivum L.) Using a High-Density SNP and SSR-Based Linkage Map

High-density genetic linkage maps are essential for precise mapping quantitative trait loci (QTL) in wheat (Triticum aestivum L.). In this study, a high-density genetic linkage map consisted of 6312 SNP and SSR markers was developed to identify QTL controlling kernel size and weight, based on a recombinant inbred line (RIL) population derived from the cross of Shixin828 and Kenong2007. Seventy-eight putative QTL for kernel length (KL), kernel width (KW), kernel diameter ratio (KDR), and thousand kernel weight (TKW) were detected over eight environments by inclusive composite interval mapping (ICIM). Of these, six stable QTL were identified in more than four environments, including two for KL (qKL-2D and qKL-6B.2), one for KW (qKW-2D.1), one for KDR (qKDR-2D.1) and two for TKW (qTKW-5A and qTKW-5B.2). Unconditional and multivariable conditional QTL mapping for TKW with respect to TKW component (TKWC) revealed that kernel dimensions played an important role in regulating the kernel weight. Seven QTL-rich genetic regions including seventeen QTL were found on chromosomes 1A (2), 2D, 3A, 4B and 5B (2) exhibiting pleiotropic effects. In particular, clusters on chromosomes 2D and 5B possessing significant QTL for kernel-related traits were highlighted. Markers tightly linked to these QTL or clusters will eventually facilitate further studies for fine mapping, candidate gene discovery and marker-assisted selection (MAS) in wheat breeding

A multifunctional nanomicelle for real-time targeted imaging and precise near-infrared cancer therapy

Simultaneous targeted cancer imaging, therapy and real-time therapeutic monitoring can prevent over- or undertreatment. This work describes the design of a multifunctional nanomicelle for recognition and precise near-infrared (NIR) cancer therapy. The nanomicelle encapsulates a new pH-activatable fluorescent probe and a robust NIR photosensitizer, R16FP, and is functionalized with a newly screened cancer-specific aptamer for targeting viable cancer cells. The fluorescent probe can light up the lysosomes for real-time imaging. Upon NIR irradiation, R16FP-mediated generation of reactive oxygen species causes lysosomal destruction and subsequently trigger lysosomal cell death. Meanwhile the fluorescent probe can reflect the cellular status and in situ visualize the treatment process. This protocol can provide molecular information for precise therapy and therapeutic monitoring. All in one: A lysosome-aimed multifunctional nanomicelle (Apt-TNP) was developed by integrating a target-cell-specific aptamer, a pH-activatable fluorescent probe, and a near-infrared photosensitizer. Apt-TNP enables simultaneous cancer imaging, photodynamic therapy, and real-time self-feedback of therapeutic efficacy. ? 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

Analyse de la prescription antibiotique dans le service de gynécologie-obstétrique d un centre hospitalier antillais (revue rétrospective de 300 séjours)

Objectif :Décrire l antibiothérapie dans le service de gynécologie-obstétrique du Centre Hospitalier Louis-Constant Fleming, déterminer les facteurs influençant la prise d antibiotiques et l adéquation de l antibiothérapie et définir d un point de vue socio-démographique la population étudiée.Matériel et méthodes : Analyse rétrospective, sur dossier médical et dossier de soin, des séjours tirés au sort entre 2009 et 2011, à l aide d un questionnaire par un staff multidisciplinaire.Résultats : 293 séjours ont été analysés, 35,5 % des patientes avaient reçu une antibiothérapie. Les pénicillines(87%) représentaient la classe thérapeutique la plus fréquemment prescrite. Les principales indications étaient la rupture prématurée des membranes (19%), le portage vaginal connu(17%) et inconnu(13%) du streptocoque du groupe B. 82% des antibiothérapies étaient protocolisées avec une conformité globale au protocole de 64%.18% des antibiothérapies étaient non protocolisées avec 55% des antibiothérapies adéquates. 78% des antibiothérapies étaient prophylactiques avec 64% de prescription adéquate. 22% des antibiothérapies étaient curatives avec 58% des prescriptions adéquates. Le taux d antibiothérapies adéquates dans l ensemble était de 59%. Une origine ethnique caribéenne était associée à un risque accru de prise d antibiotiques tandis que la présence d une comorbidité était associée à une prescription moindre. L adéquation de l antibiothérapie était meilleure en pré ou per-partum qu en post-partum. Les patientes présentaient une prévalence importante d indicateurs de précarité :38,1% n avaient pas de couverture sociale ou avaient une CMU ou AME, 54,7 % des patientes avaient un niveau scolaire inférieur au baccalauréat et 50,9 % des patientes étaient sans emploi.Conclusion : Différentes actions pourraient être menées pour améliorer l antibiothérapie : refonte des protocoles existants avec promotion active ; informatisation des prescriptions d antibiotiques et intégration du score EPICES dans le dossier obstétrical afin d organiser une prise en charge globale des patientes.Objective : To describe the antibiotherapy in the gynaecology and obstetrics department of Louis Constant Fleming Medical Center, determine the factors influencing the intake of antibiotics, whether the antibiotherapy is appropriate and define the studied population socio-demographywise.Methods: Retrospective analysis, from medical and nursing files, of the randomized stays between 2009 and 2011, with a questionnaire by a multidisciplinary staff.Results : 293 stays were analysed, 35.5 % of patients received an antibiotherapy. Penicillins (87%) was the medical treatment most commonly prescribed. The main indications were the premature rupture of membranes (19%), the vaginal carriage known (17%) and unknown (13%) of Streptococcus B. 82 % of antibiotherapies followed a protocol with 64 % of them in conformity with it. 18% of antibiotherapies did not follow a protocol with 55 % of them being appropriate. 78% of antibiotherapies were preventive with 64 % of appropriate prescriptions. 22 % of antibiotherapies were curative with 58% of them being appropriate. The rate of appropriate antibiotherapies was 59% on the whole. A caribbean ethnic origin was associated to a higher risk of antibiotic intake, as opposed to the presence of a comorbidity which was associated to a lower intake. The antibiotherapy was more appropriate in pre or per-partum, better than in post-partum. The patients had a high prevalence of indicators of precariousness : 38.1 of them had no social insurance or had CMU or AME, 54.7 of them had stopped their education before bachelor s degree and 50.9 of patients were unemployed.Conclusions : Different actions could be lead to improve the antibiotherapy : remodelling the existing protocols with active promotion; computerizing of the prescriptions of antibiotics and integration of the EPICES score in the obstetrics file to organize a global care of the female patients.ABYMES-CHRUPPA-BU (971202102) / SudocSudocFranceF

In Vitro Selection of DNA Aptamers for Metastatic Breast Cancer Cell Recognition and Tissue Imaging

National Basic Research Program of China [2010CB732402, 2013CB933703]; National Science Foundation of China [91313302, 21205100, 21275122, 21075104]; National Instrumentation Program [2011YQ03012412]; Fundamental Research Funds for the Central Universities [2012121025]; NFFTBS [J1030415]; National Science Foundation for Distinguished Young Scholars of China [21325522]Cancer is a major public health issue, with metastatic cancer accounting for the overwhelming majority of cancer deaths. Early diagnosis and appropriate treatment of metastatic cancer may largely prolong the survival rate and improve the quality of life for patients. In this study, we have identified a panel of DNA aptamers specifically binding to MDA-MB-231 cells derived from metastatic site-pleural effusion, with high affinity after 15 rounds of selections using the cell-based systematic evolution of ligands by exponential enrichment (SELEX) method. The selected aptamers were subjected to flow cytometry and laser confocal fluorescence microscopy to evaluate their binding affinity and selectivity. The aptamer LXL-1 with the highest abundance in the enriched library demonstrated a low K-d value and excellent selectivity for the recognition of the metastatic breast cancer cells. Tissue imaging results showed that truncated aptamer sequence LXL-1-A was highly specific to the corresponding tumor tissue and displayed 76% detection rate against breast cancer tissue with metastasis in regional lymph nodes. Therefore, on the basis of its excellent targeting properties and functional versatility, LXL-1-A holds great potential to be used as a molecular imaging probe for the detection of breast cancer metastasis. Our result clearly demonstrates that metastatic-cell-based SELEX can be used to generate DNA ligands specifically recognizing metastatic cancer cells, which is of great significance for metastatic cancer diagnosis and treatment

Highway constructions on the Qinghai-Tibet Plateau: Challenge, research and practice

Summary: Highway constructions on the Qinghai-Tibet Plateau (QTP) face great challenges induced by the unique local environmental, geological, and engineering conditions. The large area of permafrost, great temperature variability, strong UV rays, and complex geological conditions are the major factors that adversely influence the long-term performance of pavement systems. Since 1960s, Chinese engineers and researchers have started conducting research on the QTP to enhance the performance and durability of pavement systems. The present paper provide a comprehensive review of challenge, research and practice of highway constructions on the QTP including the special environmental and geological conditions, history of highway constructions on the QTP, major challenges and the state-of-the-art technology of subgrade constructions on permafrost, developments of the pavement structures and materials, performance prediction and maintenance methods of pavement surfaces, and applications of the research achievements on the first expressway on the QTP (i.e., Gongyu Expressway). Based on the comprehensive literature review, it can be found that (1) frost heave and thaw weakening induced subgrade disease and longitudinal cracks on the pavement surface are complex coupled water-thermal-load problems. Engineering solutions are focusing on active cooling and thermal insulation methods, which can help to reduce temperature variations in the subgrade and thus improving its stability, (2) the harsh environmental and construction conditions may reduce the early strength and induce premature damage of cement-treated base materials. Some field validations showed that geocell-reinforced or asphalt-treated flexible base materials can provide better long-term performance, (3) the large temperature variability and strong UV rays can significantly accelerate aging of asphalt binders and greatly reduce the service life of asphalt mixtures. Various binder modification methods were developed for improving their viscoelasticity and enhance the low-temperature cracking resistance of pavement surface materials but are still lack of field validation data and comparisons of their life cycle costs. Therefore, it is recommended that a demonstration research project build test sections to examine a range of pavement structures and materials, and compare their long-term performance and life cycle costs, which can serve as important reference for future highway constructions on the QTP

Using the selected aptamers to recognize FFPE normal or glioma tissue sections.

<p>FFPE tissue sections were incubated with cy5-labeled aptamers. A =  Normal brain tissue with GBM128; B =  Glioblastoma tissue with GBM128; C =  Anaplastic oligodendroglima with GBM128; D =  Oligoastrocytoma with GBM128; E =  Pilocytic astrocytoma with GBM128; F =  Normal brain tissue with GBM131; G =  Glioblastoma tissue with GBM131; H =  Anaplastic oligodendroglima with GBM131; I =  Oligoastrocytoma with GBM131; J =  Pilocytic astrocytoma with GBM131. The final concentration of Cy5-labeled aptamers was 250 nM.</p

The binding affinity assay of the enriched pools with U118 MG and SVGp12 cells.

<p>(A) The fluorescence intensity of U118-MG cells binding with selected pools increased gradually as the selection progressed, indicating that the enhanced binding affinity of enriched pools. (B)The selected pools also showed increased affinity with SVGp12 cells, but the response was apparently weaker than with U118-MG cells. Final concentration of FAM-labeled ssDNA pools was 250 nM in binding buffer.</p