Characterization of corneal structure in keratoconus

Producción CientíficaThe increasing volume of patients interested in refractive surgery and the new treatment options available for keratoconus have generated a higher interest in achieving a better characterization of this pathology. The ophthalmic devices for corneal analysis and diagnosis have experienced a rapid development during the past decade with the implementation of technologies such as the Placido-disk corneal topography and the introduction of others such as scanning-slit topography, Scheimpflug photography, and optical coherence tomography, which are able to accurately describe not only the geometry of the anterior corneal surface but also that of the posterior surface, as well as pachymetry and corneal volume. Specifically, anterior and posterior corneal elevation, corneal power, pachymetry maps, and corneal coma-like aberrometry data provide sufficient information for an accurate characterization of the cornea to avoid misleading diagnoses of patients and provide appropriate counseling of refractive surgery candidates

Eficacia de la terapia de aceptación y compromiso centrada en pensamiento negativo repetitivo en fibromialgia: Un diseño de línea base múltiple aleatorizado

Repetitive negative thinking (RNT), in the form of worry and rumination, is a factor that can have a negative impact on the quality of life and symptomatology of patients with fibromyalgia (FM). The present study analyzes the efficacy of a brief Acceptance and Commitment Therapy (ACT) protocol focused on reducing RNT in four women diagnosed with FM. A randomized, multiple-baseline design across participants was conducted. Participants completed 4-6 weeks of baseline and subsequently received a 4-session individual intervention. The effect of the intervention was assessed by conducting follow-ups for up to 3 months. All four participants showed clinically significant changes in emotional symptoms as measured by the Depression Anxiety and Stress Scale – 21 (DASS-21¸ S. H. Lovibond y P. F. Lovibond, 1995) and the General Health Questionnaire – 12 (Ruiz et al., 2017a). Likewise, participants showed significant improvements in parameters related to sleep quality and improvements in health-related quality of life. As for process measures, all participants showed clinically significant changes in pathological worry, and three of them also in cognitive fusion. Changes in valued actions were more modest. Effect sizes comparable across designs were very large and statistically significant for DASS-Total (d = 1.51), DASS-Depression (d = 1.83), pathological worry (d = 1.79), and cognitive fusion (d = 1.99). These results suggest that brief RNT-focused ACT interventions hold promise for intervention in patients with FM.El pensamiento negativo repetitivo (PNR), en la forma de rumia y preocupación, es un factor que puede generar un impacto negativo sobre la calidad de vida y sintomatología de los pacientes con fibromialgia (FM). El presente estudio analiza la eficacia de un protocolo breve de la Terapia de Aceptación y Compromiso (ACT) centrado en reducir PNR en cuatro mujeres con diagnóstico de FM. Se llevó a cabo un diseño de línea de base múltiple entre participantes aleatorizado. Las participantes completaron entre 4 y 6 semanas de línea base y, posteriormente, recibieron una intervención individual de 4 sesiones. El efecto de la intervención se evaluó realizando seguimientos hasta los 3 meses. Las cuatro participantes mostraron cambios clínicamente significativos en síntomas emocionales medidos a través del Depression Anxiety and Stress Scale – 21 (DASS-21¸ S. H. Lovibond y P. F. Lovibond, 1995) y el General Health Questionnaire – 12 (Ruiz et al., 2017a). Asimismo, las participantes mostraron mejoras significativas en parámetros relacionados con la calidad del sueño y mejoras en calidad de vida relacionada con la salud. En cuanto a las medidas de proceso, todas las participantes mostraron cambios clínicamente significativos en preocupación patológica y tres de ellas también en fusión cognitiva. Los cambios en acciones valiosas fueron más modestos. Los tamaños del efecto comparables a través de diseños fueron muy grandes y estadísticamente significativos para DASS-Total (d = 1.51), DASS-Depresión (d = 1.83), preocupación patológica (d = 1.79) y fusión cognitiva (d = 1.99)

Existence and multiplicity of solutions for fractional κ(ξ)\kappa(\xi)-Kirchhoff-type equation

In this paper, we aim to tackle the questions of existence and multiplicity of solutions to a new class of $\kappa(\xi)$-Kirchhoff-type equation utilizing a variational approach. Further, we research the results from the theory of variable exponent Sobolev spaces and from the theory of space $\psi$-fractional $\mathcal{H}^{\mu,\nu;\,\psi}_{\kappa(\xi)}(\Lambda)$. In this sense, we present a few special cases and remark on the outcomes explored.Comment: 18 page

Teeth infection may shunt through Fontan in high-altitude conditions.

The Fontan surgery involves the creation a conduit between the inferior vena cava and the right pulmonary artery. This conduit has a small fenestration that shunts the blood from right to left in case the pulmonary blood flow is limited; namely, if the pulmonary vascular resistance (PVR) is increased then the shunt is increased. Bacteria may bypass the pulmonary circulation and easily get access to the systemic circulation (bacteremia). We report the case of a patient that underwent Fontan surgery in 2010 and remained in a high-altitude city for 7 years, during this time he was asymptomatic until 2017 when he developed a brain abscess due to Streptococcus gordonii, a pathogen of dental plaque. Since high-altitude may raise PVR in response to reduction in the partial pressure of oxygen, we conclude that the long-term outcome of increased altitude on Fontan hemodynamics can lead to the shunt of teeth flora and consequently leading to severe infections

Langerin-Heparin Interaction: Two Binding Sites for Small and Large Ligands as revealed by a combination of NMR Spectroscopy and Cross-Linking Mapping Experiments

Langerin is a C-type lectin present on Langerhans cells that mediates capture of pathogens in a carbohydrate-dependent manner, leading to subsequent internalization and elimination in the cellular organelles called Birbeck granules. This mechanism mediated by langerin was shown to constitute a natural barrier for HIV-1 particle transmission. Besides interacting specifically with high mannose and fucosylated neutral carbohydrate structures, langerin has the ability to bind sulfated carbohydrate ligands as 6-sulfated galactosides in the Ca2+ dependent binding site. Very recently langerin was demonstrated to interact with sulfated glycosaminoglycans (GAGs), in a Ca2+ independent way, resulting in the proposal of a new binding site for GAGs. Based on those results, we have conducted a structural study of the interactions of small heparin (HEP) like oligosaccharides with langerin in solution. Heparin-bead cross-linking experiments, an approach specifically designed to identify HEP/HS binding sites in proteins were first carried out and experimentally validated the previously proposed model for the interaction of Lg ECD with 6 kDa HEP. High-resolution NMR studies of a set of 8 synthetic HEP-like trisaccharides harboring different sulfation patterns demonstrated that all of them bound to langerin in a Ca2+ dependent way. The binding epitopes were determined by STD NMR and the bound conformations by transferred NOESY experiments. These experimental data were combined with docking and molecular dynamics and resulted in the proposal of a binding mode characterized by the coordination of calcium by the two equatorial hydroxyl groups OH3 and OH4 at the non-reducing end. The binding also includes the carboxylate group at the adjacent iduronate residue. Such epitope is shared by all the 8 ligands, explaining the absence of any impact on binding from their differences in substitution pattern. Finally, in contrast to the small trisaccharides, we demonstrated that a longer HEP-like hexasaccharide, bearing an additional O-sulfate group at the non-reducing end, which precludes binding to the Ca2+ site, interacts with langerin in the previously identified Ca2+ independent binding site

Multidrug-Resistant Mycobacterium tuberculosis, Southwestern Colombia

Using spoligotyping, we identified 13 genotypes and 17 orphan types among 160 Mycobacterium tuberculosis isolates from patients in Valle del Cauca, Colombia. The Beijing genotype represented 15.6% of the isolates and was correlated with multidrug-resistant tuberculosis, female sex of the patients, and residence in Buenaventura and may represent a new public health threat

Selective Loss of Chemokine Receptor Expression on Leukocytes after Cell Isolation

Chemokine receptors are distinctively exposed on cells to characterize their migration pattern. However, little is known about factors that may regulate their expression. To determine the optimal conditions for an accurate analysis of chemokine receptors, we compared the expression of CCR2, CCR4, CCR5, CCR6, CXCR3 and CXCR4 on different leukocyte subsets using whole blood (WB) plus erythrocyte lysis and density gradient isolation (Ficoll). Most WB monocytes were CCR2+ (93.5±2.9%) whereas 32.8±6.0% of monocytes from Ficoll-PBMC expressed CCR2 (p<0.001). Significant reductions of CCR6 and CXCR3 on monocytes were also observed after Ficoll isolation (WB: 46.4±7.5% and 57.1±5.5%; Ficoll: 29.5±2.2% and 5.4±4.3% respectively) (p<0.01). Although comparable percentages of WB and Ficoll-PBMC monocytes expressed CCR4, CCR5 and CXCR4, Ficoll isolation significantly reduced the levels of CXCR4 (WB: MFI 5±0.4 and Ficoll: MFI 3.3±0.1) (p<0.05). Similarly to monocytes, CCR2, CXCR3 and CXCR4 were also reduced on lymphocytes. In addition, Ficoll isolation significantly reduced the percentage of CCR4 positive lymphocytes (WB: 90.2±4.5% and Ficoll: 55±4.1%) (p<0.01). The loss of expression of chemokine receptors after isolation of monocytes was not dependent on either the anticoagulant or the density gradient method. It was irreversible and could not be restored by LPS activation or in vitro macrophage differentiation. Experiments tagged with anti-CCR2 antibodies prior to density gradient isolation demonstrated that Ficoll internalized chemokine receptors. The method for cell isolation may alter not only the expression of certain chemokine receptors but also the respective functional migration assay. The final choice to analyze their expression should therefore depend on the receptor to be measured

Towards Modelling QFT in Real Metamaterials: Singular Potentials and Self-Adjoint Extensions

[EN] Solutions of the one-dimensional Schrödinger equation are found when point interactions of the type aδ(x − q) + bδ'(x − q) are placed either in a couple of points or in a regular lattice. The results obtained in the present study are a first step toward a rigorous mathematical model of real metamaterials is Solid State Physics

Evidence for a 3 x 10^8 solar mass black hole in NGC 7052 from HST observations of the nuclear gas disk

We present an HST study of the nuclear region of the E4 radio galaxy NGC 7052, which has a nuclear disk of dust and gas. The WFPC2 was used to obtain B, V and I broad-band images and an H_alpha+[NII] narrow-band image. The FOS was used to obtain H_alpha+[NII] spectra along the major axis, using a 0.26 arcsec diameter circular aperture. The observed rotation velocity of the ionized gas is V = 155 +/- 17 km/s at r = 0.2 arcsec from the nucleus. The Gaussian dispersion of the emission lines increases from sigma = 70 km/s at r=1 arcsec, to sigma = 400 km/s on the nucleus. To interpret the gas kinematics we construct axisymmetric models in which the gas and dust reside in a disk in the equatorial plane of the stellar body. It is assumed that the gas moves on circular orbits, with an intrinsic velocity dispersion due to turbulence. The circular velocity is calculated from the combined gravitational potential of the stars and a possible nuclear black hole (BH). Models without a BH predict a rotation curve that is shallower than observed (V_pred = 92 km/s at r = 0.2 arcsec), and are ruled out at > 99% confidence. Models with a BH of 3.3^{+2.3}_{-1.3} x 10^8 solar masses provide an acceptable fit. NGC 7052 can be added to the list of active galaxies for which HST spectra of a nuclear gas disk provide evidence for the presence of a central BH. The BH masses inferred for M87, M84, NGC 6251, NGC 4261 and NGC 7052 span a range of a factor 10, with NGC 7052 falling on the low end. By contrast, the luminosities of these galaxies are identical to within 25%. Any relation between BH mass and luminosity, as suggested by independent arguments, must therefore have a scatter of at least a factor 10.Comment: 39 pages, LaTeX, with 16 PostScript figures. Submitted to the Astronomical Journal. Postscript version with higher resolution figures available from http://sol.stsci.edu/~marel/abstracts/abs_R22.htm