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161.
162.
Guimera A Gabriel G Plata-Cordero M Montero L Maldonado MJ Villa R 《Biosensors & bioelectronics》2012,31(1):55-61
The permeability of the cornea epithelial layer has an important role in optimal function of the cornea. To assess this property quantitatively, methods must be based on the passive electrical properties of living tissues, as they can take advantage of the fundamental role that ionic permeability plays in such properties. For such techniques, measurement of the translayer electrical resistance (TER) has been consistently used to examine the ion transport mechanisms in the corneal epithelial cells; however, this technique has been only possible in vitro. To enhance the applications of this method, in this work we present a novel sensor to perform non-invasive in vivo TER measurements. Herein, the epithelial permeability was assessed using non-invasive tetrapolar impedance measurements that were performed with four electrodes placed on the corneal surface. The geometry of these electrodes was previously optimized to maximize the sensitivity of the corneal epithelium. To evaluate the feasibility of this sensor, the permeability of a rabbit corneal epithelium was monitored by applying a solution of benzalkonium chloride (0.05% BAC). The results validate the capability of the sensor to evaluate the cornea epithelial permeability in vivo. 相似文献
163.
De-Nova JA Medina R Montero JC Weeks A Rosell JA Olson ME Eguiarte LE Magallón S 《The New phytologist》2012,193(1):276-287
? Mesoamerican arid biomes epitomize neotropical rich and complex biodiversity. To document some of the macroevolutionary processes underlying the vast species richness of Mesoamerican seasonally dry tropical forests (SDTFs), and to evaluate specific predictions about the age, geographical structure and niche conservatism of SDTF-centered woody plant lineages, the diversification of Bursera is reconstructed. ? Using a nearly complete Bursera species-level phylogeny from nuclear and plastid genomic markers, we estimate divergence times, test for phylogenetic and temporal diversification heterogeneity, test for geographical structure, and reconstruct habitat shifts. ? Bursera became differentiated in the earliest Eocene, but diversified during independent early Miocene consecutive radiations that took place in SDTFs. The late Miocene average age of Bursera species, the presence of phylogenetic geographical structure, and its strong conservatism to SDTFs conform to expectations derived from South American SDTF-centered lineages. ? The diversification of Bursera suggests that Mesoamerican SDTF richness derives from high speciation from the Miocene onwards uncoupled from habitat shifts, during a period of enhanced aridity resulting mainly from global cooling and regional rain shadows. 相似文献
164.
Olloquequi J García-Valero J Rodríguez E Montero MA Ferrer J Montes JF 《Histology and histopathology》2012,27(1):39-47
Among all inflammatory cells involved in COPD, those with a cytolytic or elastolytic activity are thought to play a key role in the pathogenesis of the disease. However, there is no data about the infiltration of cells expressing the CD57 marker in small airways and parenchyma of COPD patients. In this study, surgical specimens from 43 subjects undergoing lung resection due to lung cancer (9 non-smokers, 18 smokers without COPD and 16 smokers with moderate COPD) and 16 patients undergoing double lung transplantation for very severe COPD were examined. CD57+ cells, neutrophils, macrophages and mast cells infiltrating bronchioles (epithelium, smooth muscle and connective tissue) and parenchymal interstitium were localized and quantified by immunohistochemical analysis. Compared to the other groups, the small airways of very severe COPD patients showed a significantly higher density of CD57+ cells, mainly infiltrated in the connective tissue (p=0.001), and a significantly higher density of neutrophils located characteristically in the epithelium (p=0.037). Also, the density of neutrophils was significantly higher in parenchyma of very severe COPD patients compared with the rest of the groups (p=0.001). Finally, there were significant correlations between the bronchiolar density of CD57+ cells and the FEV1 values (R=-0.43, p=0.022), as well as between the parenchymal density of neutrophils and macroscopic emphysema degree (R=0.43, p=0.048) in COPD groups. These results show that CD57+ cells may be involved in COPD pathogenesis, especially in the most severe stages of the disease. 相似文献
165.
Carreras-Aubets M Montero FE Kostadinova A Gibson DI Carrassón M 《Systematic parasitology》2012,82(3):185-199
Two frequently reported but poorly known hemiurid digeneans, Lecithochirium musculus (Looss, 1907) (Lecithochiriinae), from the stomach of Trachinus draco and Citharus linguatula, and Ectenurus lepidus Looss, 1907 (Dinurinae), from the stomach of Spicara maena, are redescribed based on material from off the Barcelona coast of the western Mediterranean. The two species are commented upon, and Lecithochirium israelense Fischthal, 1980 is considered a synonym of L. musculus. Records of the two species in the Mediterranean Basin and North East Atlantic region are summarised. 相似文献
166.
Preliminary atomic force microscopy study of two-dimensional crystals of lactose permease from Escherichia coli 总被引:1,自引:0,他引:1
Lactose permease (LacY) of Escherichia coli is not only a paradigm for secondary transporters but also for difficulties in two-dimensional (2D) crystallization. In this work we present the progresses achieved in the observation of 2D crystals of wild-type LacY by atomic force microscopy (AFM). Crystals were obtained following reconstitution of LacY in 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) liposomes. Proteolipid sheets (PLSs) 6.4 nm in height were obtained after spreading the samples onto mica. Observations were carried out in liquid medium and in contact mode (CM-AFM). When the crystalline surfaces of the PLSs were imaged regular packing arrangements were observed. The back-Fourier transformation revealed the existence of various orientations mostly consistent with crystals possessing p2 symmetry and unit-cell dimensions: a=13.15 nm, b=16.74 nm, gamma=116 degrees. The characteristics, size, and shape of the repetitive motif could be compatible with dimers of this protein. These preliminary results are compared and discussed with previously reported 2D crystals observed by electron microscopy. 相似文献
167.
Domènech O Sanz F Montero MT Hernández-Borrell J 《Biochimica et biophysica acta》2006,1758(2):213-221
Cardiolipin (CL) is a phospholipid found in the energy-transducing membranes of bacteria and mitochondria and it is thought to be involved in relevant biological processes as apoptosis. In this work, the mixing properties of CL and 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocoline (POPC) and 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphoethanolamine (POPE) at the air-water interface, have been examined using the thermodynamic framework analysis of compression isotherms. Accordingly, the values of the Gibbs energy of mixing, the more stable monolayers assayed were: POPC:CL (0.6:0.4, mol:mol) and POPE:CL (0.8:0.2, mol:mol). The results reflect that attractive forces are the greatest contributors to the total interaction in these compositions. Supported planar bilayers (SPBs) with such compositions were examined using atomic force microscopy (AFM) at different temperatures. With the POPC:CL mixture, rounded and featureless SPBs were obtained at 4 degrees C and 24 degrees C. In contrast, the extension of the POPE:CL mixture revealed the existence of different lipid domains at 24 degrees C and 37 degrees C. Three lipid domains coexisted which can be distinguished by measuring the step height difference between the uncovered mica and the bilayer. While the low and intermediate domains were temperature dependent, the high domain was composition dependent. When cytochrome c (cyt c) was injected into the fluid cell, the protein showed a preferential adsorption onto the high domain of the POPC:CL. These results suggest that the high domain is mainly formed by CL. 相似文献
168.
Seridi A Kadri M Abdaoui M Winum JY Montero JL 《Bioorganic & medicinal chemistry letters》2006,16(4):1021-1027
The kinetics decomposition of 2-chloroethylnitrososulfamides (CENS) was studied in aqueous buffered solutions with pH ranging from 0 to 14. The study was monitored by RP-LC-MS and conventional UV spectrophotometry. The reaction proceeded via a pseudo-first-order kinetic with significant correlation coefficient. The major decomposition products from CENS after incubation in phosphate buffer were isolated and identified by NMR and mass spectrometry. The results indicate that the mechanism pathway involves a denitrosation of the CENS and competitive hydrolysis with nucleophilic attack on the sulfur atom and formation of sulfamate compounds. 相似文献
169.
Diaz-Montero CM Salem ML Nishimura MI Garrett-Mayer E Cole DJ Montero AJ 《Cancer immunology, immunotherapy : CII》2009,58(1):49-59
Abnormal accumulation of myeloid-derived suppressor cells (MDSC) is an important mechanism of tumor immune evasion. Cyclophosphamide
(CTX) has also been shown in non-tumor bearing animals to cause transient surges in MDSC. Knowledge of MDSC is primarily based
on preclinical work, and to date only few published studies have involved cancer patients. The goal of this study was to test
the hypothesis that circulating MDSC levels correlate with clinical cancer stage, CTX-based chemotherapy, and metastatic tumor
burden. Whole blood was collected from 106 newly diagnosed solid tumor patients (stages I–IV). Percentages of circulating
MDSC (Lin−/Lo, HLA DR−, CD33+CD11b+) were determined prior to initiation of systemic therapy. In 17 early stage breast cancer patients receiving doxorubicin–cyclophosphamide
chemotherapy every 14 days (ddAC) blood was collected on day 1 of each cycle. Circulating MDSC were significantly increased
in cancer patients of all stages relative to healthy volunteers. A significant correlation between circulating MDSC and clinical
cancer stage was also observed. Moreover, among stage IV patients, those with extensive metastatic tumor burden had the highest
percent and absolute number of MDSC. Significant increases in circulating MDSC were observed with ddAC when compared with
pretreatment levels. Circulating MDSC levels correlate with clinical cancer stage, ddAC, and metastatic tumor burden. This
information must be incorporated into the design of future trials exploring immune-based therapeutic strategies. Pharmacologic
modulation of MDSC should also be tested in future clinical trials. 相似文献
170.
Elias Daura-Oller Maria Cabre Miguel A Montero Jose L Paternain Antoni Romeu 《Bioinformation》2009,3(8):340-343
Giving coding region structural features a role in the hypomethylation of specific genes, the occurrence of G+C content,
CpG islands, repeat and retrotransposable elements in demethylated genes related to cancer has been evaluated. A
comparative analysis among different cancer types has also been performed. In this work, the inter-cancer coding region
features comparative analysis carried out, show insights into what structural trends/patterns are present in the studied cancers. 相似文献