María Jesús Aira Rodríguez

One Step Synthesis of the Smallest Photoluminescent and Paramagnetic PVP-Protected Gold Atomic Clusters

Gold atomic clusters of only two and three atoms were prepared by a simple electrochemical technique based on the anodic dissolution of a gold electrode in the presence of PVP, and subsequent electroreduction of the Au-PVP complexes. These clusters show stable photoluminescent and magnetic properties, which make them the smallest and most elemental gold (0) building blocks in nature (after atoms) bringing new possibilities to construct novel nano/microstructures with large potential interest in biomedicine, catalysis, and so forth.

Biomarkers characterization of circulating tumour cells in breast cancer patients

IntroductionIncreasing evidence supports the view that the detection of circulating tumor cells (CTCs) predicts outcomes of nonmetastatic breast cancer patients. CTCs differ genetically from the primary tumor and may contribute to variations in prognosis and response to therapy. As we start to understand more about the biology of CTCs, we can begin to address how best to treat this form of disease.MethodsNinety-eight nonmetastatic breast cancer patients were included in this study. CTCs were isolated by immunomagnetic techniques using magnetic beads labelled with a multi-CK-specific antibody (CK3-11D5) and CTC detection through immunocytochemical methods. Estrogen receptor, progesterone receptor and epidermal growth factor receptor (EGFR) were evaluated by immunofluorescence experiments and HER2 and TOP2A by fluorescence in situ hybridization. We aimed to characterize this set of biomarkers in CTCs and correlate it with clinical-pathological characteristics.ResultsBaseline detection rate was 46.9% ≥ 1 CTC/30 ml threshold. CTC-positive cells were more frequent in HER2-negative tumors (p = 0.046). In patients younger than 50 years old, HER2-amplified and G1-G2 tumors had a higher possibility of being nondetectable CTCs. Heterogeneous expression of hormonal receptors (HRs) in samples from the same patients was found. Discordances between HR expression, HER2 and TOP2A status in CTCs and their primary tumor were found in the sequential blood samples. Less that 35% of patients switched their CTC status after receiving chemotherapy. EGFR-positive CTCs were associated with Luminal tumors (p = 0.03).ConclusionsThis is the largest exploratory CTC biomarker analysis in nonmetastatic BC patients. Our study suggests that CTC biomarkers profiles might be useful as a surrogate marker for therapeutic selection and monitoring since heterogeneity of the biomarker distribution in CTCs and the lack of correlation with the primary tumor biomarker status were found. Further exploration of the association between EGFR-positive CTCs and Luminal tumors is warranted.

In vivo cell imaging with semiconductor quantum dots and noble metal nanodots

Innovations in fluorescence microscopy of live cells involving new reagents and techniques reveal dynamic processes that were not previously observable and therefore unknown. Water soluble, biofunctionalized semiconductor quantum dots (QDs) provide advantages of much greater photostability compared to conventional fluorescent dyes, and, as a consequence, single QDs can be easily detected. QDs coupled to growth factor ligands behave similarly as the natural ligand and serve as highly fluorescent probes of the erbB family of tyrosine kinase receptors in living cells. Continuous confocal laser scanning microscopy and flow cytometry measurements of QDs combined with visible fluorescent fusions of the receptors have elucidated individual steps in the signaling cascades initiated by these receptors. This report highlights advantages and some disadvantages of QDs, such as size and blinking behavior that complicate some live cell imaging applications. The new class of noble metal nanodots constitute an attractive alternative to QDs in that they are not only highly fluorescent and photostable, but also, much smaller and nontoxic. We present a new synthesis method for the production of Au nanodots. We demonstrate that electrochemical synthesis allows the reproducible control of cluster size. The resulting clusters are more monodisperse than those formed by other methods and are stable over many months. We report their characterization using MALDI-TOF mass spectrometry and UV-VIS spectroscopy.

Use of the cobas 4800 system for the rapid detection of toxigenic Clostridium difficile and methicillin-resistant Staphylococcus aureus

The new cobas® Cdiff and cobas® MRSA/SA tests were compared with conventional methods for the rapid detection of toxigenic Clostridium difficile and methicillin-resistant Staphylococcus aureus. The final concordance between cobas Cdiff Test and GDH/toxin gene screening was 97.62% and between cobas MRSA/SA Test and chromogenic culture, 91.30%, respectively.

Distribución y características palinológicas de las mieles de Eucalyptus gallegas

SEijo, M. C., AtRa, M. J.& JATO, M. V. 1998. Distribucion y caracteristicas palinologicas de las mieles de Eucalyptus gallegas. Bot. Complutensis 22:133-143. Se ha realizado el estudio polinico de 60 muestras de miel de Galicia con porcentajes superiores al 70% de polen de Eucalyptus por lo que se han considerado mieles monoflorales. El 10% de las muestras analizadas presentan valores de polen de Eucalyptus superiores al 89%, el 34% presenta valores comprendidos entre el 80% y el 89%, el 56% restante contiene valores entre el 70% y el 79%. El numero medio de tipos polinicos en ios espectros de estas mieles es de 25 y su contenido en indicadores de mielada es nulo. En cuanto a su riqueza polinica son mieles pobres en polen presentando un-a media de 4.753 granos de polen por gramo de miel. En general, las mieles de eucalipto de Galicia presentan cristalizacion tardia y color ambar.