Comparacion de un nuevo agente basado en nanotecnología con el talco convencional para el control de los derrames pleurales malignos / Comparison between a new nanotechnology-based agent and conventional talc in the control of malignant pleural effusions

En este trabajo usamos dióxido de titanio (TiO2), fabricado mediante nanotecnología. Para demostrar su superioridad respecto al talco, realizamos un estudio in vitro comparando la respuesta pro-inflamatoria de ambos agentes sobre células malignas y mesoteliales benignas; investigando la posible inducción de apoptosis y la posible inhibición de angiogénesis también por ambos agentes. Realizamos cultivo de líneas celulares derivadas de mesotelio humano, procedente de mesotelioma bifásico humano y adenocarcinoma bronquial humano. Las células se co-cultivaron con diferentes dosis de talco y de nanopartículas de TiO2. En todas las muestras de sobrenadantes de los cultivos se analizaron los niveles de diferentes mediadores inflamatorios. La tasa de apoptosis se analizó por la expresión de Caspasa-3. Para el estudio de angiostasis se determinaron los niveles de endostatina mediante técnica ELISA. Observamos que la viabilidad de las células mesoteliales benignas es mucho menor al emplear TiO2. En el caso de las células mesoteliales malignas, se observó el mismo efecto con dosis alta de TiO2. En el adenocarcinoma de pulmón, la viabilidad de estas células expuestas al talco fue netamente inferior a la que se observó en la línea celular benigna. La producción de IL-8 fue mucho mayor por parte de las células mesoteliales neoplásicas que por las benignas y aumentó siguiendo un patrón dosis dependiente frente al talco, mientras que cayó con el TiO2. Según estos resultados, se demuestra que el talco es superior al TiO2 en su capacidad de producir mediadores que favorecerían la pleurodesis para el control del derrame pleural maligno

For this study, we used titanium dioxide (TiO2), produced using nanotechnology. To show its superiority with respect to talc, we completed an in vitro study comparing the pro-inflammatory response of both agents towards malignant and benign mesothelial cells; researching the possible apoptosis induction and possible inhibition of angiogenesis for both agents. We took a culture of cell lines derived from human mesothelioma, originating from human biphasic mesothelioma and human bronchial adenocarcinoma. The cells were cocultured with different doses of talc and TiO2 nanoparticles. The levels of different inflammatory mediators were analyzed for each culture supernatant sample. The apoptosis rate was analyzed using caspase-3 expression. The endostatin levels were determined for the angiostasis study using the ELISA technique. We observed that the viability of the benign mesothelial cells is much lower after using TiO2. In the case of malignant mesothelial cells, the same effect was observed with a high dose of TiO2. In adenocarcinoma of the lung, the viability of these cells exposed to talc was distinctly lower than that which was observed in the benign cell line. IL-8 production was much higher in neoplastic mesothelial cells than in benign cells and increased following a dose-dependent pattern with talc, while it decreased with TiO2. According to these results, we can see that talc is superior to TiO2 in its ability to produce mediators which favor pleurodesis for the control of malignant pleural effusions

Ecobroncoscopia / No disponible

La ecografía endobronquial (EBUS: endobronchial ultrasound) combina en un endoscopio flexible dos sistemas de imagen: uno óptico, idéntico al de los broncoscopios convencionales y una sonda de ecografía. Existen dos tipos de ecobroncoscopios: lineal/sectorial y radial. El primero disponible fue el ecobroncoscopio radial, pero en la actualidad el más utilizado es el lineal. Las principales indicaciones de la ecobroncoscopia radial se refieren al estudio de lesiones pulmonares periféricas y a la exploración de la pared traqueobronquial para ver si existe infiltración neoplásica o no. Su principal desventaja es que no permite la toma de muestras en tiempo real. Sus complicaciones son las mismas que una broncoscopia convencional con reali-zación de biopsias transbronquiales siendo, por tanto, una técnica segura y muy eficaz. La ecobroncoscopia lineal tiene como principal indicación la estadificación mediastínica en pacientes con sospecha o previamente diagnosticados de cáncer de pulmón primario o metastático, aunque también se utiliza para la evaluación mediastínica en otras patologías. El uso de Doppler color permite la diferenciación de estructuras vasculares, lo que hace la técnica más segura. Su principal ventaja respecto a la ecobroncoscopia radial es que permite la punción en tiempo real. Es una técnica segura, cuya tasa de complicaciones es muy baja (1,5%)

No disponible

Redox signalling in chloroplasts and mitochondria: genomic and biochemical evidence for two-component regulatory systems in bioenergetic organelles.

Redox chemistry is central to the primary functions of chloroplasts and mitochondria, that is, to energy conversion in photosynthesis and respiration. However, these bioenergetic organelles always contain very small, specialized genetic systems, relics of their bacterial origin. At huge cost, organellar genomes contain, typically, a mere 0.1% of the genetic information in a eukaryotic cell. There is evidence that chloroplast and mitochondrial genomes encode proteins whose function and biogenesis are particularly tightly governed by electron transfer. We have identified nuclear genes for 'bacterial' histidine sensor kinases and aspartate response regulators that seem to be targeted to chloroplast and mitochondrial membranes. Sequence similarities to cyanobacterial redox signalling components indicate homology and suggest conserved sensory and signalling functions. Two-component redox signalling pathways might be ancient, conserved mechanisms that permit endogenous control over the biogenesis, in situ, of bioenergetic complexes of chloroplasts and mitochondria.

The complete set of genes encoding major intrinsic proteins in Arabidopsis provides a framework for a new nomenclature for major intrinsic proteins in plants.

Major intrinsic proteins (MIPs) facilitate the passive transport of small polar molecules across membranes. MIPs constitute a very old family of proteins and different forms have been found in all kinds of living organisms, including bacteria, fungi, animals, and plants. In the genomic sequence of Arabidopsis, we have identified 35 different MIP-encoding genes. Based on sequence similarity, these 35 proteins are divided into four different subfamilies: plasma membrane intrinsic proteins, tonoplast intrinsic proteins, NOD26-like intrinsic proteins also called NOD26-like MIPs, and the recently discovered small basic intrinsic proteins. In Arabidopsis, there are 13 plasma membrane intrinsic proteins, 10 tonoplast intrinsic proteins, nine NOD26-like intrinsic proteins, and three small basic intrinsic proteins. The gene structure in general is conserved within each subfamily, although there is a tendency to lose introns. Based on phylogenetic comparisons of maize (Zea mays) and Arabidopsis MIPs (AtMIPs), it is argued that the general intron patterns in the subfamilies were formed before the split of monocotyledons and dicotyledons. Although the gene structure is unique for each subfamily, there is a common pattern in how transmembrane helices are encoded on the exons in three of the subfamilies. The nomenclature for plant MIPs varies widely between different species but also between subfamilies in the same species. Based on the phylogeny of all AtMIPs, a new and more consistent nomenclature is proposed. The complete set of AtMIPs, together with the new nomenclature, will facilitate the isolation, classification, and labeling of plant MIPs from other species.

Structural characterization of two aquaporins isolated from native spinach leaf plasma membranes.

Two members of the aquaporin family, PM28A and a new one, PM28C, were isolated and shown to be the major constituents of spinach leaf plasma membranes. These two isoforms were identified and characterized by matrix-assisted laser desorption ionization-mass spectrometry. Edman degradation yielded the amino acid sequence of two domains belonging to the new isoform. PM28B, a previously described isoform, was not found in our preparations. Scanning transmission electron microscopy mass analysis revealed both PM28 isoforms to be tetrameric. Two types of particles, a larger and a smaller one, were found by transmission electron microscopy of negatively stained solubilized proteins and by atomic force microscopy of PM28 two-dimensional crystals. The ratio of larger to smaller particles observed by transmission electron microscopy and single particle analysis correlated with the ratio of PM28A to PM28C determined by matrix-assisted laser desorption ionization-mass spectrometry. The absence of PM28B and the ratio of PM28A to PM28C indicate that these plasma membrane intrinsic proteins are differentially expressed in spinach leaves. These findings suggest that differential expression of the various aquaporin isoforms may regulate the water flux across the plasma membrane, in addition to the known mechanism of regulation by phosphorylation.

Isospin tracing: A probe of nonequilibrium in central heavy-Ion collisions

Four different combinations of 9644Ru and 9640Zr nuclei, both as projectile and target, were investigated at the same bombarding energy of 400A MeV using a 4pi detector. The degree of isospin mixing between projectile and target nucleons is mapped across a large portion of the phase space using two different isospin-tracer observables, the number of measured protons and the tritium to 3He yield ratio. The experimental results show that the global equilibrium is not reached even in the most central collisions. Quantitative measures of stopping and mixing are extracted from the data. They are found to exhibit a quite strong sensitivity to the in-medium ( n,n) cross section used in microscopic transport calculations.

Influence of high light and UV-B radiation on photosynthesis and D1 turnover in atrazine-tolerant and -sensitive cultivars of Brassica napus.

An atrazine-tolerant mutant and an atrazine-sensitive cultivar of Brassica napus L. were grown under visible radiation (400 mumol m-2 s-1, photosynthetically active radiation, PAR) and then subjected to treatment conditions. These included short-term high PAR (1600 mumol m-2 s-1) which was given for 4 h either alone or in combination with an enhanced level of UV-BBE radiation (4.6 kJ m-2 h-1 biologically effective UV-B, 280-320 nm). Recovery from the radiation treatment was studied for 4 h under the light conditions for growth. Since it is known that the atrazine-tolerant mutant is susceptible to photoinhibition, one of the aims of the present study was to determine the effects of a supplemental, enhanced level of UV-B radiation with regard to the mutant. The results indicate an additive effect of UV-B radiation on Fv/Fm, photochemical yield and photosynthetic oxygen evolution during both exposure and recovery, and also a higher susceptibility of the mutant to photoinhibitory PAR conditions alone and in combination with UV-B, which may have implications in a changing environment. Both cultivars also showed a higher D1 turnover during the radiation stress than during recovery, as shown by immunoblotting and 35S-methionine incorporation measurements.

Proton production in relativistic heavy ion collisions; comparison with a thermodynamical model.

Experimental results concerning proton production in nuclear collisions, obtained at Saturne with the Diogene 4 pi facility, are compared with the predictions of a thermodynamical model, using collective velocity distributions combined with a statistical thermodynamics in local rest frames. Experimental differential cross sections for alpha + nucleus and Neon + nucleus central collisions at incident energies between 200 and 800 MeV per nucleon are well reproduced by the model, for an angular range 30-110 degrees in the laboratory system. Extracted values of the temperatures are compared with those given by other authors.

Nuclear collective flow and charged-pion emission in Ne-nucleus collisions at E/A = 800 MeV.

Triple-differential cross sections of charged pions were measured for collisions of Ne projectiles at E/A = 800 MeV with NaF, Nb, and Pb targets. The reaction plane was estimated event by event from the light-baryon momentum distribution. For heavy targets, preferential emission of charged pions away from the interaction zone towards the projectile side was observed in the transverse direction. Such a preferential emission, which is not predicted by cascade calculations, may be attributed to a stronger pion absorption by the heavier spectator remnant.

Proton-proton correlations at small relative momentum in neon-nucleus collisions at E/A=400 and 800 MeV.

Proton-proton small angle correlations have been measured in neon-nucleus collisions, using the 4 pi detector Diogene, at 400 and 800 MeV per nucleon incident energies. Values of the size of the emitting region are obtained by comparison with the Koonin formula, taking into account the biases of the apparatus. The dependence of the density on target mass and incident energy is also analysed.

Exclusive measurements of mean pion multiplicities in 4He-nucleus reactions from 200 to 800 MeV/nucleon.

Mean multiplicities of pi+ and pi- in 4He collisions with C, Cu, and Pb at 200, 600, and 800 MeV/u, and with C and Pb at 400 MeV/u have been measured using the large solid angle detector Diogene. The independence of pion multiplicity on projectile incident energy, target mass and proton multiplicity is studied in comparison with intra-nuclear cascade predictions. The discrepancy between experimental results and theory is pointed out and discussed.