273 research outputs found

    Clinical Application of Optical Coherence Tomography in the Corneal Degenerations

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    Anterior segment optical coherence tomography (AS-OCT) has become an essential tool in the diagnosis and management of corneal degenerations. AS-OCT optical findings and thickness measurements are useful for the proper evaluation of the ocular surface diseases. AS-OCT imaging provides noninvasive information necessary to decide clinical and surgical management. This device helps to achieve a correct pre-intervention investigation and will allow physicians to compare the corneal status after the surgical process. Thus, it is useful to evaluate the corneal thickness, areas of hyper-reflective material, and corneal fibrosis in certain disorders such as Salzmann’s nodular degeneration (SND) and Terrien’s marginal degeneration (TMD), before and following the surgical process

    A small molecule tubulin depolymerizing agent identified by a phenotypic drug discovery approach

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    In the scenario of drug discovery, numerous in vitro testing initiatives had been established. Thus far, no general methodology is reputable and literature on this hot topic is scarce. In this respect, we propose a strategy based on a Phenotypic Drug Discovery approach. Within our program directed at the discovery of new antitumor agents, we have focused our attention on compounds that disturb the cell cycle. Our strategy relies on the use of a set of biological assays organized in a modular fashion. Herein, we exemplified this strategy with a family of propargylic enol ether derivatives. Using different assays in sequential stages and in a stepwise manner, our studies allowed us to understand the bioactivity of this family of compounds and led us to identify tubulin as the main molecular target.info:eu-repo/semantics/publishedVersio

    Corneal biomechanical parameters and central corneal thickness in glaucoma patients, glaucoma suspects, and a healthy population

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    Purpose: To evaluate and compare corneal hysteresis (CH), corneal resistance factor (CRF), and central corneal thickness (CCT), measurements were taken between a healthy population (controls), patients diagnosed with glaucoma (DG), and glaucoma suspect patients due to ocular hypertension (OHT), family history of glaucoma (FHG), or glaucoma-like optic discs (GLD). Additionally, Goldmann-correlated intraocular pressure (IOPg) and corneal-compensated IOP (IOPcc) were compared between the different groups of patients. Methods: In this prospective analytical-observational study, a total of 1065 patients (one eye of each) were recruited to undergo Ocular Response Analyzer (ORA) testing, ultrasound pachymetry, and clinical examination. Corneal biomechanical parameters (CH, CRF), CCT, IOPg, and IOPcc were measured in the control group (n = 574) and the other groups: DG (n = 147), FHG (n = 78), GLD (n = 90), and OHT (n = 176). We performed a variance analysis (ANOVA) for all the dependent variables according to the different diagnostic categories with multiple comparisons to identify the differences between the diagnostic categories, deeming p < 0.05 as statistically significant. Results: The mean CH in the DG group (9.69 mmHg) was significantly lower compared to controls (10.75 mmHg; mean difference 1.05, p < 0.001), FHG (10.70 mmHg; mean difference 1.00, p < 0.05), GLD (10.63 mmHg; mean difference 0.93, p < 0.05) and OHT (10.54 mmHg; mean difference 0.84, p < 0.05). No glaucoma suspects (FHG, GLD, OHT groups) presented significant differences between themselves and the control group (p = 1.00). No statistically significant differences were found in the mean CRF between DG (11.18 mmHg) and the control group (10.75 mmHg; mean difference 0.42, p = 0.40). The FHG and OHT groups showed significantly higher mean CRF values (12.32 and 12.41 mmHg, respectively) than the DG group (11.18 mmHg), with mean differences of 1.13 (p < 0.05) and 1.22 (p < 0.001), respectively. No statistically significant differences were found in CCT in the analysis between DG (562 μ) and the other groups (control = 556 μ, FHG = 576 μ, GLD = 569 μ, OHT = 570 μ). The means of IOPg and IOPcc values were higher in the DG patient and suspect groups than in the control group, with statistically significant differences in all groups (p < 0.001). Conclusion: This study presents corneal biomechanical values (CH, CRF), CCT, IOPg, and IOPcc for diagnosed glaucoma patients, three suspected glaucoma groups, and a healthy population, using the ORA. Mean CH values were markedly lower in the DG group (diagnosed with glaucoma damage) compared to the other groups. No significant difference was found in CCT between the DG and control groups. Unexpectedly, CRF showed higher values in all groups than in the control group, but the difference was only statistically significant in the suspect groups (FHG, GLD, and OHT), not in the DG group

    Protective effect of bovine lactoferrin against Cronobacter sakazakii in human intestinal Caco-2/TC7 cells

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    Milk is a source of bioactive proteins with defensive properties of great value for protecting the newborn. The activity of bovine milk lactoferrin (LF) was investigated as an antibacterial agent in the internalisation of the emergent pathogen Cronobacter sakazakii into Caco-2/TC7 cells, a model of human intestinal epithelium. The effect of LF on oxidative stress and expression of Toll-like receptors (TLR) was also investigated. LF exerted a clear antibacterial activity against C. sakazakii, as well as an inhibitory effect on C. sakazakii adhesion and internalisation into Caco-2/TC7 cells. Incubation with C. sakazakii induced an increase in oxidative stress on the lipid fraction of Caco-2/TC7 cells, which was reversed by LF. Additionally, LF altered the expression of TLR, with a clear decrease in the expression levels of TLR4 at 24 h of incubation. These results suggest that LF has very interesting properties as a potential ingredient for functional foods

    Influence of the Cenozoic substrate on the origin and sedimentation of a soda lake (Caballo Alba, Central Spain)

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    La laguna de Caballo Alba (Segovia) es un pequeño lago efímero hiperalcalino del Humedal Coca-Olmedo de salmueras clorurado-sódicas, cuyo sustrato y área de drenaje están formados por rocas margosas miocenas y retazos de terrazas cuaternarias. Este trabajo se centra en analizar la influencia de la estructura y litología del sustrato Cenozoico en el origen de la laguna y composición mineralógica de sus sedimentos. Se muestra que el origen y forma de Caballo Alba están controlados por las fracturas NNW-SSE que afectan al Cenozoico y constituyen las principales vías de alimentación de agua mediante flujos subterráneos. El sedimento reciente de Caballo Alba incluye sulfatos y carbonatos (cálcicos, magnésicos y sódicos), y arcillas. El estudio comparativo de las margas miocenas y del sedimento lagunar revela que en Caballo Alba probablemente se están depositando esmectitas autigénicasCaballo Alba is a highly alkaline and ephemeral lake located in a wetland area of the Duero basin (central Spain). The lake contains sodium chloride water and overlies Miocene marlstone deposits and Quaternary terraces. The purpose of this paper is to study the impact of the structure and lithology of the Cenozoic substrate in both the origin of the lake and mineralogy of the lake deposits. The origin and shape of Caballo Alba was controlled by NNW-SSE fractures affecting the substrate. These fractures provide the main pathways of groundwater to the lakes. Lacustrine deposits are comprised of clays and authigenic calcium, magnesium and sodium carbonates, and sulfates. The comparative analysis of the mineralogy between Miocene marls and lacustrine deposits reveals that authigenic smectites are also forming in the lak

    An Update on Corneal Biomechanics and Architecture in Diabetes

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    In the last decade, we have witnessed substantial progress in our understanding of corneal biomechanics and architecture. It is well known that diabetes is a systemic metabolic disease that causes chronic progressive damage in the main organs of the human body, including the eyeball. Although the main and most widely recognized ocular effect of diabetes is on the retina, the structure of the cornea (the outermost and transparent tissue of the eye) can also be affected by the poor glycemic control characterizing diabetes. e different corneal structures (epithelium, stroma, and endothelium) are affected by specific complications of diabetes. e development of new noninvasive diagnostic technologies has provided a better understanding of corneal tissue modifications. e objective of this review is to describe the advances in the knowledge of the corneal alterations that diabetes can induc

    Shadows and spirals in the protoplanetary disk HD 100453

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    Understanding the diversity of planets requires to study the morphology and the physical conditions in the protoplanetary disks in which they form. We observed and spatially resolved the disk around the ~10 Myr old protoplanetary disk HD 100453 in polarized scattered light with SPHERE/VLT at optical and near-infrared wavelengths, reaching an angular resolution of ~0.02", and an inner working angle of ~0.09". We detect polarized scattered light up to ~0.42" (~48 au) and detect a cavity, a rim with azimuthal brightness variations at an inclination of 38 degrees, two shadows and two symmetric spiral arms. The spiral arms originate near the location of the shadows, close to the semi major axis. We detect a faint spiral-like feature in the SW that can be interpreted as the scattering surface of the bottom side of the disk, if the disk is tidally truncated by the M-dwarf companion currently seen at a projected distance of ~119 au. We construct a radiative transfer model that accounts for the main characteristics of the features with an inner and outer disk misaligned by ~72 degrees. The azimuthal brightness variations along the rim are well reproduced with the scattering phase function of the model. While spirals can be triggered by the tidal interaction with the companion, the close proximity of the spirals to the shadows suggests that the shadows could also play a role. The change in stellar illumination along the rim, induces an azimuthal variation of the scale height that can contribute to the brightness variations. Dark regions in polarized images of transition disks are now detected in a handful of disks and often interpreted as shadows due to a misaligned inner disk. The origin of such a misalignment in HD 100453, and of the spirals, is unclear, and might be due to a yet-undetected massive companion inside the cavity, and on an inclined orbit.Comment: A&A, accepte

    Computational simulation of scleral buckling surgery for rhegmatogenous retinal detachment: on the effect of the band size on the myopization

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    A finite element model (FE) of the eye including cornea, sclera, crystalline lens, and ciliary body was created to analyze the influence of the silicone encircling bandwidth and the tightness degree on the myopia induced by scleral buckling (SB) procedure for rhegmatogenous retinal detachment. Intraocular pressure (IOP) was applied to the reference geometry of the FE model and then SB surgery was simulated with encircling bandwidths of 1, 2, and 2.5 mm. Different levels of tightening and three values of IOP were applied.The anterior segment resulted as unaffected by the surgery. The highest value of Cauchy stress appeared in the surroundings of the implant, whereas no increment of stress was observed either in anterior segment or in the optic nerve head. The initial IOP did not appear to play any role in the induced myopia.The wider the band, the greater the induced myopia: 0.44, 0.88, and 1.07 diopters (D) for the 1, 2, and 2.5mm bandwidth, respectively.Therefore, patients become more myopic with a wider encircling element. The proposed simulations allow determining the effect of the bandwidth or the tightness degree on the axial lengthening, thus predicting the myopic increment caused by the encircling surgery.The authors wish to acknowledge the research support by the Spanish Ministry of Education and Science Research Project DPI2014-54981R, the CIBER initiative, Instituto de Salud Carlos III (ISCIII) Platformfor Biological Tissue Characterization of the Centro de Investigación Biomédica en Red en Bioingeniería, Biomateriales y Nanomedicina (CIBERBBN), and the Department of Industry and Innovation (Government of Aragón) through the research group Grant T88 (Fondo Social Europeo)

    Post conjunction detection of β\beta Pictoris b with VLT/SPHERE

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    With an orbital distance comparable to that of Saturn in the solar system, \bpic b is the closest (semi-major axis \simeq\,9\,au) exoplanet that has been imaged to orbit a star. Thus it offers unique opportunities for detailed studies of its orbital, physical, and atmospheric properties, and of disk-planet interactions. With the exception of the discovery observations in 2003 with NaCo at the Very Large Telescope (VLT), all following astrometric measurements relative to \bpic have been obtained in the southwestern part of the orbit, which severely limits the determination of the planet's orbital parameters. We aimed at further constraining \bpic b orbital properties using more data, and, in particular, data taken in the northeastern part of the orbit. We used SPHERE at the VLT to precisely monitor the orbital motion of beta \bpic b since first light of the instrument in 2014. We were able to monitor the planet until November 2016, when its angular separation became too small (125 mas, i.e., 1.6\,au) and prevented further detection. We redetected \bpic b on the northeast side of the disk at a separation of 139\,mas and a PA of 30^{\circ} in September 2018. The planetary orbit is now well constrained. With a semi-major axis (sma) of a=9.0±0.5a = 9.0 \pm 0.5 au (1 σ\sigma ), it definitely excludes previously reported possible long orbital periods, and excludes \bpic b as the origin of photometric variations that took place in 1981. We also refine the eccentricity and inclination of the planet. From an instrumental point of view, these data demonstrate that it is possible to detect, if they exist, young massive Jupiters that orbit at less than 2 au from a star that is 20 pc away.Comment: accepted by A&
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