728 research outputs found
Association between sleep-disordered breathing and breast cancer aggressiveness
Background
Sleep-disordered breathing (SDB) has been associated with cancer aggressiveness, but studies focused on specific tumors are lacking. In this pilot study we investigated whether SDB is associated with breast cancer (BC) aggressiveness.
Methods
83 consecutive women <65 years diagnosed with primary BC underwent a home respiratory polygraphy. Markers of SDB severity included the apnea-hypopnea index (AHI) and the 4% oxygen desaturation index (ODI4). The Ki67 proliferation index, lack of hormone receptors (HR-), Nottingham Histological Grade (NHG), and tumor stage were used as markers of BC aggressiveness. The association between SDB and molecular subtypes of BC was also assessed.
Results
The mean (SD) age was 48.8 (8.8) years and body mass index was 27.4 (5.4) Kg/m2. 42 women (50.6%) were post-menopausal. The median (IQR) AHI was 5.1 (2–9.4), and ODI4 was 1.5 (0.5–5.8). The median (IQR) AHI did not differ between the groups with Ki67>28% and Ki6728% and Ki67<29% (51.2% vs 52.3%, p = 0.90), HR- and HR+ (58.3% vs 49.1%, p = 0.47), NHG categories (p = 0.89), different tumor stages (p = 0.71), or molecular subtypes (p = 0.73). These results did not change when the ODI4 was used instead of the AHI.
Conclusion
Our results do not support an association between the presence or severity of SDB and BC aggressiveness.Asociación de Neumología y Cirugía Torácica del Sur (NEUMOSUR) 1/201
Vegetation of the La Invernada Valley (Don Carmelo Private Reserve) in the central-west of San Juan Province (Argentina
Vegetation of the La Invernada valley (Don Carmelo Private Reserve) in the central-west of San Juan province (Argentina). In this paper, the vegetation of La Invernada valley, located in the Andean Precordillera of San Juan province, was analyzed. A total of 146 floristic releves were made, and environmental variables as slope, geomorphologic unit, altitude, plant cover were recorded, and physic-chemical analyses of soils were carried out. The biologic and chorologic spectra for each community were performed. Obtained data were analyzed using multivariate methods. In total, 143 vascular plant species were recorded, and ten plant communities determined. Dominant life forms were chamaephytes and hemicriptophytes. Chorologically the studied area belongs to the Cuyano District of the phytogeographical province of Puna, while below 2600 m a.s.l. elements of Cardonal and Monte are found.Los estudios de las comunidades vegetales en el sector andino de la provincia de San Juan (Argentina) son escasos. En la precordillera provincial, el valle La Invernada fue declarado área protegida en 1993 con la denominación de Reserva Privada de Usos Múltiples Don Carmelo. A pesar de ser un área de interés desde el punto de vista fitogeográfico, carece de estudios de su vegetación. El objetivo de este trabajo fue determinar florísticamente las comunidades vegetales, los pisos de vegetación y las unidades fitogeográficas de la reserva.Fil: Ripoll Busso, Yanina Elizabeth. Universidad Nacional de San Juan. Facultad de Ciencias Exactas Físicas y Naturales. Departamento de Biología; ArgentinaFil: Martinez Carretero, Eduardo Enrique. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Investigaciones de las Zonas Áridas. Provincia de Mendoza. Instituto Argentino de Investigaciones de las Zonas Áridas. Universidad Nacional de Cuyo. Instituto Argentino de Investigaciones de las Zonas Áridas; Argentina. Universidad Nacional de San Juan. Facultad de Ciencias Exactas Físicas y Naturales. Departamento de Biología; Argentin
Structural organisation of the type IV secretion systems
Type IV secretion (T4S) systems are large dynamic nanomachines that transport DNAs and/or proteins through the membranes of bacteria. Because of their complexity and multi-protein organisation, T4S systems have been extremely challenging to study structurally. However in the past five years significant milestones have been achieved by X-ray crystallography and cryo-electron microscopy. This review describes some of the more recent advances: the structures of some of the protein components of the T4S systems and the complete core complex structure that was determined using electron microscopy
Recent advances in the structural and molecular biology of type IV secretion systems
Bacteria use type IV secretion (T4S) systems to deliver DNA and protein substrates to a diverse range of prokaryotic and eukaryotic target cells. T4S systems have great impact on human health, as they are a major source of antibiotic resistance spread among bacteria and are central to infection processes of many pathogens. Therefore, deciphering the structure and underlying translocation mechanism of T4S systems is crucial to facilitate development of new drugs. The last five years have witnessed considerable progress in unraveling the structure of T4S system subassemblies, notably that of the T4S system core complex, a large 1 MegaDalton (MDa) structure embedded in the double membrane of Gram-negative bacteria and made of 3 of the 12 T4S system components. However, the recent determination of the structure of ∼3 MDa assembly of 8 of these components has revolutionized our views of T4S system architecture and opened up new avenues of research, which are discussed in this review
Conjugation Inhibitors and Their Potential Use to Prevent Dissemination of Antibiotic Resistance Genes in Bacteria
Antibiotic resistance has become one of the most challenging problems in health care. Bacteria conjugation is one of the main mechanisms whereby bacteria become resistant to antibiotics. Therefore, the search for specific conjugation inhibitors (COINs) is of interest in the fight against the spread of antibiotic resistances in a variety of laboratory and natural environments. Several compounds, discovered as COINs, are promising candidates in the fight against plasmid dissemination. In this review, we survey the effectiveness and toxicity of the most relevant compounds. Particular emphasis has been placed on unsaturated fatty acid derivatives, as they have been shown to be efficient in preventing plasmid invasiveness in bacterial populations. Biochemical and structural studies have provided insights concerning their potential molecular targets and inhibitory mechanisms. These findings open a new avenue in the search of new and more effective synthetic inhibitors. In this pursuit, the use of structure-based drug design methods will be of great importance for the screening of ligands and binding sites of putative targets.
Metodología para modelizar una red de tráfico en la que se van a obtener datos mediante la técnica del escaneo de matrículas
[ES] En el presente artículo se aborda el problema de modelizar una red de tráfico para poder
aplicar la técnica del escaneo de matrículas para estimar flujos en ruta, y por tanto obtener
la matriz Origen-Destino así como la asignación de la red. Para llevar a cabo dicha
modelización se plantea una metodología que trata de manera global la simplificación de la
red y que tiene como base la reducción del número de rutas mediante la eliminación de
pares Origen-Destino que no tengan una demanda relevante. Dicha simplificación tiene un
enfoque práctico muy diferente de la visión tradicional de zonificación y disposición de
centroides dentro de la red y que permitirá imbricarla con los modelos de ubicación de
dispositivos de escaneo.
La metodología permite detectar aquellos arcos de la red que son afectados por la
simplificación y las consecuencias sobre la estimación de flujos que puedan derivarse de
dicha afección. Con todo ello, se puede establecer una priorización en la ubicación de los
equipos de escaneo que permitirá hacer una reconstrucción más fiable de los flujos de la
red.
Se ha empleado una red basada en la denominada red Nguyen-Dupuis como ejemplo de
aplicación de la metodología desarrollada. A través del mismo se irá aclarando paso por
paso cada una de las fases del método.Sánchez Cambronero, S.; Rivas Álvarez, A.; Barba Contreras, R.; Ruiz Ripoll, L.; Gallego Giner, M.; Menéndez Martinez, J. (2016). Metodología para modelizar una red de tráfico en la que se van a obtener datos mediante la técnica del escaneo de matrículas. En XII Congreso de ingeniería del transporte. 7, 8 y 9 de Junio, Valencia (España). Editorial Universitat Politècnica de València. 1142-1154. https://doi.org/10.4995/CIT2016.2015.4216OCS1142115
Sancti Cirici de Colera / Sant Quirze de Colera (Alt Empordà, Girona). Estudio preliminar del conjunto monástico, siglos VIII al XVI
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