Pseudomonas aeruginosa productora de metabolito con actividad antimicrobiana contra Burkholderia glumae

The present study had as objective to evaluate in vitro antimicrobial activity of endphytes bacteria associated with Neem (Azadirachta indica) against Burkholderia glumae. The inhibitory activity of endophytic bacteria against B. glumae was evaluated by antagonism, using the technique of diffusion in agar with sensitive records. Once identified the endophytic bacteria inhibitory potential, used discs medium numbers 3 for production of secondary metabolites, to test their inhibition against B. glumae by Elisa plate microdilution methods. The results showed an inhibition of 50% of the growth against B. glumae, the identification with API 20 NE kit found in 99,55% to the species Pseudomonas aeruginosa.El presente estudio tuvo como objetivo evaluar in vitro la actividad antimicrobiana de bacterias endófitas asociadas a Neem (Azadirachta indica) contra la bacteria fitopatógena Burkholderia glumae. La actividad inhibitoria de bacterias endófitas contra B. glumae se evaluó por antagonismo, mediante la técnica de difusión en agar con discos sensitivos. Una vez identificadas las bacterias endófitas con potencial inhibitorio, se empleó medio número 3 para producción de metabolitos secundarios, para probar su inhibición contra B. glumae mediante la técnica de microdilucion en placas de Elisa. Los resultados mostraron, una inhibición del 50% del crecimiento de B. glumae por parte de la bacteria endófita asilada. La identificación de la bacteria endófita con potencial inhibitorio contra B. glumae se realizó por medio un kit API 20 NE, donde el perfil de identificación arrojo un 99,5% para Pseudomonas aeruginosa

Cortactin regulates cofilin and N-WASp activities to control the stages of invadopodium assembly and maturation

Invadopodia are matrix-degrading membrane protrusions in invasive carcinoma cells. The mechanisms regulating invadopodium assembly and maturation are not understood. We have dissected the stages of invadopodium assembly and maturation and show that invadopodia use cortactin phosphorylation as a master switch during these processes. In particular, cortactin phosphorylation was found to regulate cofilin and Arp2/3 complex–dependent actin polymerization. Cortactin directly binds cofilin and inhibits its severing activity. Cortactin phosphorylation is required to release this inhibition so cofilin can sever actin filaments to create barbed ends at invadopodia to support Arp2/3-dependent actin polymerization. After barbed end formation, cortactin is dephosphorylated, which blocks cofilin severing activity thereby stabilizing invadopodia. These findings identify novel mechanisms for actin polymerization in the invadopodia of metastatic carcinoma cells and define four distinct stages of invadopodium assembly and maturation consisting of invadopodium precursor formation, actin polymerization, stabilization, and matrix degradation

Fitoplancton en el sistema lagunar tropical Carmen Pajonal Machona, Tabasco

Background. Phytoplankton is considered an important indicator of natural and anthropogenic processes that take place in basins and coastal environments. An example of these systems is the formed by the El Car- men, Pajonal and La Machona lagoons, in which there is intense fishing and oyster farming activity, as well as agricultural activities, oil extraction and forestry in their surroundings. Goals.Identifying the phytoplankton species, with emphasis on the potentially harmful and / or toxic ones, their distribution and differences between the samplings, north winds (2015) and rainy (2016), as well as reporting the physicochemical variables was the aimed of this work. Methods. Net samples with a mesh size of 20 μm were taken and physicoche- mical variables were measured with a water quality sonde. 300 organisms were counted and the specific richness, relative abundances and diversity index were calculated. To identify differences between the two seasons sampled the Mann-Whitney U test was performed. In addition, the most important physicochemical variables were identified to explore their relationship with the species through a distance-based redundancy analysis (dbRDA). Results. A total of 86 species were identified, of which ten are new records and 15 are potentially harmful and / or toxic ones. The taxonomic group with the most species in both seasons was Bacillaryophyta (43 Northeast and 22 Rains). Specific richness was significantly different between seasons. In the north winds season, the most abundant species were from the Cyanoprokaryota and Bacillaryophyta groups, while for rainy season they were from the Dinoflagellata. Conclusions. Water temperature and salinity were the physicochemical variables that defined the phyto- plankton composition in the CPM lagoons; the presence of potentially toxic species is an alert for the lagoon system because it reflects a latent situation that could trigger blooms at any time.Antecedentes. El fitoplancton es considerado un indicador importante de los procesos naturales y antro- pogénicos que se desarrollan en las cuencas y en los ambientes costeros. Un ejemplo de estos sistemas es el conformado por las lagunas El Carmen, Pajonal y La Machona (CPM), en las cuales hay una intensa actividad pesquera y de ostricultura, así como actividades agrícolas, extracción petrolera y forestal a sus alrededores. Objetivo. El objetivo fue identificar las especies fitoplanctónicas, con énfasis en las potencial- mente nocivas y/o tóxicas, su distribución y diferencias entre los muestreos, nortes (2015) y lluvias (2016), así como reportar las variables fisicoquímicas. Métodos. Se tomaron muestras de red de 20 μm de abertura de malla y midieron las variables con una sonda de calidad de agua. Se contabilizaron 300 organismos y se obtuvieron la riqueza específica, abundancias relativas e índice de diversidad. Para identificar diferencias entre las dos temporadas muestreadas se realizó la prueba U de Mann-Whitney. Además, se identificaron las variables fisicoquímicas más importantes para explorar su relación con las especies mediante un análisis de redundancia basado en distancias (dbRDA). Resultados. Se identificaron un total de 86 especies de las cuales diez son nuevos registros para el área y 15 son potencialmente tóxicas. El grupo taxonómico con más especies fue el de las Bacillaryophyta (43 nortes y 22 lluvias). La riqueza específica fue significativamente diferente entre temporadas. Las especies más abundantes fueron de los grupos de las Cyanoprokaryota y las Bacillaryophyta para la temporada de nortes, mientras que para la temporada de lluvias fueron del grupo Dinoflagellata. Conclusiones. La temperatura y la salinidad fueron las variables que determinaron la com- posición del fitoplancton en las lagunas CPM; la presencia de especies potencialmente tóxicas es una alerta para el sistema lagunar debido a que refleja una situación latente que podría desencadenar florecimientos en cualquier momento

Loss of Ambra1 promotes melanoma growth and invasion

Melanoma is the deadliest skin cancer. Despite improvements in the understanding of the molecular mechanisms underlying melanoma biology and in defining new curative strategies, the therapeutic needs for this disease have not yet been fulfilled. Herein, we provide evidence that the Activating Molecule in Beclin-1-Regulated Autophagy (Ambra1) contributes to melanoma development. Indeed, we show that Ambra1 deficiency confers accelerated tumor growth and decreased overall survival in Braf/Pten-mutated mouse models of melanoma. Also, we demonstrate that Ambra1 deletion promotes melanoma aggressiveness and metastasis by increasing cell motility/invasion and activating an EMT-like process. Moreover, we show that Ambra1 deficiency in melanoma impacts extracellular matrix remodeling and induces hyperactivation of the focal adhesion kinase 1 (FAK1) signaling, whose inhibition is able to reduce cell invasion and melanoma growth. Overall, our findings identify a function for AMBRA1 as tumor suppressor in melanoma, proposing FAK1 inhibition as a therapeutic strategy for AMBRA1 low-expressing melanoma. The absence of scaffold protein Ambra1 leads to hyperproliferation and growth in mouse models. Here the authors show that Ambra1 deficiency accelerates melanoma growth and increases metastasis in mouse models of melanoma through FAK1 hyperactivation

Protective role of chaperone-mediated autophagy against atherosclerosis

Significance Cardiovascular diseases remain the leading cause of death worldwide, with atherosclerosis being the most common source of clinical events. Metabolic changes with aging associate with concurrent increased risk of both type 2 diabetes and cardiovascular disease, with the former further raising the risk of the latter. The activity of a selective type of autophagy, chaperone-mediated autophagy (CMA), decreases with age or upon dietary excesses. Here we study whether reduced CMA activity increases risk of atherosclerosis in mouse models. We have identified that CMA is up-regulated early in response to proatherogenic challenges and demonstrate that reduced systemic CMA aggravates vascular pathology in these conditions. We also provide proof-of-concept support that CMA up-regulation is an effective intervention to reduce atherosclerosis severity and progression

LIM kinase function and renal growth: potential role for LIM kinases in fetal programming of kidney development

Aims Maternal dietary restriction during pregnancy impairs nephron development and results in offspring with fewer nephrons. Cell turnover in the early developing kidney is altered by exposure to maternal dietary restriction and may be regulated by the LIM-kinase family of enzymes. We set out to establish whether disturbance of LIM-kinase activity might play a role in the impairment of nephron formation. Main methods E12.5 metanephric kidneys and HK2 cells were grown in culture with the pharmacological LIM-kinase inhibitor BMS5. Organs were injected with DiI, imaged and cell numbers measured over 48 h to assess growth. Cells undergoing mitosis were visualised by pH 3 labelling. Key findings Growth of cultured kidneys reduced to 83% of controls after exposure to BMS5 and final cell number to 25% of control levels after 48 h. Whilst control and BMS5 treated organs showed cells undergoing mitosis (100 ± 11 cells/field vs 113 ± 18 cells/field respectively) the proportion in anaphase was considerably diminished with BMS5 treatment (7.8 ± 0.8% vs 0.8 ± 0.6% respectively; P < 0.01). This was consistent with effects on HK2 cells highlighting a severe impact of BMS5 on formation of the mitotic spindle and centriole positioning. DiI labelled cells migrated in 100% of control cultures vs 0% BMS5 treated organs. The number of nephrogenic precursor cells appeared depleted in whole organs and formation of new nephrons was blocked by exposure to BMS5. Significance Pharmacological blockade of LIM-kinase function in the early developing kidney results in failure of renal development. This is likely due to prevention of dividing cells from completion of mitosis with their resultant loss

Anisotropy and chemical composition of ultra-high energy cosmic rays using arrival directions measured by the Pierre Auger Observatory

The Pierre Auger Collaboration has reported evidence for anisotropy in the distribution of arrival directions of the cosmic rays with energies $E>E_{th}=5.5\times 10^{19}$ eV. These show a correlation with the distribution of nearby extragalactic objects, including an apparent excess around the direction of Centaurus A. If the particles responsible for these excesses at $E>E_{th}$ are heavy nuclei with charge $Z$, the proton component of the sources should lead to excesses in the same regions at energies $E/Z$. We here report the lack of anisotropies in these directions at energies above $E_{th}/Z$ (for illustrative values of $Z=6,\ 13,\ 26$). If the anisotropies above $E_{th}$ are due to nuclei with charge $Z$, and under reasonable assumptions about the acceleration process, these observations imply stringent constraints on the allowed proton fraction at the lower energies

Protective role of chaperone-mediated autophagy against atherosclerosis

Chaperone-mediated autophagy (CMA) contributes to regulation of energy homeostasis by timely degradation of enzymes involved in glucose and lipid metabolism. Here, we report reduced CMA activity in vascular smooth muscle cells and macrophages in murine and human arteries in response to atherosclerotic challenges. We show that in vivo genetic blockage of CMA worsens atherosclerotic pathology through both systemic and cell-autonomous changes in vascular smooth muscle cells and macrophages, the two main cell types involved in atherogenesis. CMA deficiency promotes dedifferentiation of vascular smooth muscle cells and a proinflammatory state in macrophages. Conversely, a genetic mouse model with up-regulated CMA shows lower vulnerability to proatherosclerotic challenges. We propose that CMA could be an attractive therapeutic target against cardiovascular diseases

Update on the correlation of the highest energy cosmic rays with nearby extragalactic matter

Data collected by the Pierre Auger Observatory through 31 August 2007 showed evidence for anisotropy in the arrival directions of cosmic rays above the Greisen-Zatsepin-Kuz'min energy threshold, \nobreak{$6\times 10^{19}$eV}. The anisotropy was measured by the fraction of arrival directions that are less than $3.1^\circ$ from the position of an active galactic nucleus within 75 Mpc (using the V\'eron-Cetty and V\'eron $12^{\rm th}$ catalog). An updated measurement of this fraction is reported here using the arrival directions of cosmic rays recorded above the same energy threshold through 31 December 2009. The number of arrival directions has increased from 27 to 69, allowing a more precise measurement. The correlating fraction is $(38^{+7}_{-6})$, compared with $21$ expected for isotropic cosmic rays. This is down from the early estimate of $(69^{+11}_{-13})$. The enlarged set of arrival directions is examined also in relation to other populations of nearby extragalactic objects: galaxies in the 2 Microns All Sky Survey and active galactic nuclei detected in hard X-rays by the Swift Burst Alert Telescope. A celestial region around the position of the radiogalaxy Cen A has the largest excess of arrival directions relative to isotropic expectations. The 2-point autocorrelation function is shown for the enlarged set of arrival directions and compared to the isotropic expectation.Comment: Accepted for publication in Astroparticle Physics on 31 August 201

The Fluorescence Detector of the Pierre Auger Observatory

The Pierre Auger Observatory is a hybrid detector for ultra-high energy cosmic rays. It combines a surface array to measure secondary particles at ground level together with a fluorescence detector to measure the development of air showers in the atmosphere above the array. The fluorescence detector comprises 24 large telescopes specialized for measuring the nitrogen fluorescence caused by charged particles of cosmic ray air showers. In this paper we describe the components of the fluorescence detector including its optical system, the design of the camera, the electronics, and the systems for relative and absolute calibration. We also discuss the operation and the monitoring of the detector. Finally, we evaluate the detector performance and precision of shower reconstructions.Comment: 53 pages. Submitted to Nuclear Instruments and Methods in Physics Research Section