Optical coherence tomography angiography: a non-invasive tool to image end-arterial system

Optical coherence tomography angiography (OCTA) is a relatively novel technology for in vivo imaging of vascular network. It uses moving erythrocytes as contrasting mechanism and avoids the use of intravenous dyes. A depth-resolved 3-dimensional image set can be generated within seconds using the technique of OCTA. Therefore, it possesses a great potential for widespread application in ophthalmic angiography. Herein we discuss the most common technologies behind OCTA and the scope of future technical improvement. We provide a perspective on advantages and disadvantages of OCTA over conventional fluorescein angiography and indocyanine green angiography. Lastly, current literature on the clinical application of OCTA in common ocular diseases including neovascular age-related macular degeneration, diabetic retinopathy, retinal artery and vein occlusion, and glaucoma are reviewed

An Alternate Method of Classifying Allergic Bronchopulmonary Aspergillosis Based on High-Attenuation Mucus

Allergic bronchopulmonary aspergillosis (ABPA) is classified radiologically based on the findings of central bronchiectasis (CB) and other radiologic features (ORF). However, the long-term clinical significance of these classifications remains unknown. We hypothesized that the immunological activity and outcomes of ABPA could be predicted on HRCT chest finding of high-attenuation mucus (HAM), a marker of inflammatory activity. In this study, we evaluate the severity and clinical outcomes of ABPA with different radiological classifications. specific IgE levels, eosinophil count) severity of the disease and clinical outcomes in various classifications were analyzed.Of the 234 (123 males, 111 females; mean age, 34.1 years) patients, 55 (23.5%) had normal HRCT, 179 (76.5%) had CB, 49 (20.9%) had HAM, and 27 (11.5%) had ORF. All immunological markers were consistently higher in the HAM classification, while in other classifications these findings were inconsistent. On multivariate analysis, the factors predicting frequent relapses were presence of HAM (OR 7.38; 95% CI, 3.21–17.0) and CB (OR 3.93; 95% CI, 1.63–9.48) after adjusting for ORF.The classification scheme based on HAM most consistently predicts immunological severity in ABPA. Central bronchiectasis and HAM are independent predictors of recurrent relapses in ABPA. Hence, HAM should be employed in the radiological classification of ABPA

On the fermionic T-duality of the AdS_4 \times CP^3 sigma-model

In this note we consider a fermionic T-duality of the coset realization of the type IIA sigma-model on AdS_4 \times CP^3 with respect to the three flat directions in AdS_4, six of the fermionic coordinates and three of the CP^3 directions. We show that the Buscher procedure fails as it leads to a singular transformation and discuss the result and its implications.Comment: LaTeX2e, 9 pages, no figures, JHEP style; v2: minor clarifications; v3: typos fixed, matches the published versio

Assessment of retinal vascular calibres as a biomarker of disease activity in birdshot chorioretinopathy

Purpose Birdshot chorioretinopathy (BCR) is a potentially blinding ocular disorder involving the retinal vasculature and choroid without any systemic manifestations. The objective of the study was to describe vascular calibre changes in BCR and analyse the possibility of this optical biomarker for staging and monitoring disease activity in BCR. Methods This retrospective case–control study at a tertiary referral eye centre in the UK included 33 eyes from 21 patients with BCR and equal number of eyes from control subjects. Diagnosis of BCR was confirmed on fundus fluorescein and indocyanine green angiography. Vascular calibres were measured using validated semiautomated software. Results Patients with BCR had smaller retinal venular calibres central retinal venular equivalent (CRVE) than controls (211.3 versus 227.9 μm, p = 0.008). After adjusting for variables, the difference between the two groups for CRVE at baseline was statistically significant based on two different analysis methods. Central retinal venular equivalent (CRVE) was lower at the 6-month follow-up visit (206.2 versus 213.8 μm, p-value = 0.03), and arteriole-to-venule ratio was larger (0.74 versus 0.71, p = 0.04) in subjects with BCR. Arteriolar calibre (CRAE) remained the same. Conclusion This study provides novel insight into the pattern of vascular involvement in BCR. There was significant difference in the CRVE in patients with BCR. More studies are needed to correlate this data with visual function and treatment outcome and to validate the findings

Morphometric features on enhanced depth imaging optical coherence tomography scans in idiopathic posterior uveitis or panuveitis

PURPOSE: Enhanced depth imaging (EDI) optical coherence tomography (OCT) has emerged as a novel tool for qualitative and quantitative choroidal assessment in posterior uveitis. The objective of this study was to investigate the role of EDI-OCT to assess the choroidal and retinal changes in posterior uveitis. METHODS: In this retrospective study, EDI-OCT scans of patients with idiopathic posterior uveitis or panuveitis were reviewed. Morphological features from retina and choroid from the OCT scans were assessed and compared to the fellow normal eyes. Follow-up assessment was performed at 6-month follow-up. RESULTS: Nineteen patients with idiopathic posterior or panuveitis were included in the study. Choroidal examination using EDI-OCT scans showed areas of focal hypo-reflective and discrete hyper-reflective foci in one-third patients. Macular edema, disruption of the ellipsoid zone (generalized and discrete), outer retinal hyper-reflective foci, and intraretinal and subretinal fluid were observed. CONCLUSIONS: The index study reports qualitative OCT-derived parameters as possible tools in monitoring disease progression in uveitis

Biomechanical Thresholds Regulate Inflammation through the NF-κB Pathway: Experiments and Modeling

BACKGROUND: During normal physical activities cartilage experiences dynamic compressive forces that are essential to maintain cartilage integrity. However, at non-physiologic levels these signals can induce inflammation and initiate cartilage destruction. Here, by examining the pro-inflammatory signaling networks, we developed a mathematical model to show the magnitude-dependent regulation of chondrocytic responses by compressive forces. METHODOLOGY/PRINCIPAL FINDINGS: Chondrocytic cells grown in 3-D scaffolds were subjected to various magnitudes of dynamic compressive strain (DCS), and the regulation of pro-inflammatory gene expression via activation of nuclear factor-kappa B (NF-kappaB) signaling cascade examined. Experimental evidences provide the existence of a threshold in the magnitude of DCS that regulates the mRNA expression of nitric oxide synthase (NOS2), an inducible pro-inflammatory enzyme. Interestingly, below this threshold, DCS inhibits the interleukin-1beta (IL-1beta)-induced pro-inflammatory gene expression, with the degree of suppression depending on the magnitude of DCS. This suppression of NOS2 by DCS correlates with the attenuation of the NF-kappaB signaling pathway as measured by IL-1beta-induced phosphorylation of the inhibitor of kappa B (IkappaB)-alpha, degradation of IkappaB-alpha and IkappaB-beta, and subsequent nuclear translocation of NF-kappaB p65. A mathematical model developed to understand the complex dynamics of the system predicts two thresholds in the magnitudes of DCS, one for the inhibition of IL-1beta-induced expression of NOS2 by DCS at low magnitudes, and second for the DCS-induced expression of NOS2 at higher magnitudes. CONCLUSIONS/SIGNIFICANCE: Experimental and computational results indicate that biomechanical signals suppress and induce inflammation at critical thresholds through activation/suppression of the NF-kappaB signaling pathway. These thresholds arise due to the bistable behavior of the networks originating from the positive feedback loop between NF-kappaB and its target genes. These findings lay initial groundwork for the identification of the thresholds in physical activities that can differentiate its favorable actions from its unfavorable consequences on joints

From Correlators to Wilson Loops in Chern-Simons Matter Theories

We study n-point correlation functions for chiral primary operators in three dimensional supersymmetric Chern-Simons matter theories. Our analysis is carried on in N=2 superspace and covers N=2,3 supersymmetric CFT's, the N=6 ABJM and the N=8 BLG models. In the limit where the positions of adjacent operators become light-like, we find that the one-loop n-point correlator divided by its tree level expression coincides with a light-like n-polygon Wilson loop. Remarkably, the result can be simply expressed as a linear combination of five dimensional two-mass easy boxes. We manage to evaluate the integrals analytically and find a vanishing result, in agreement with previous findings for Wilson loops.Comment: 32 pages, 6 figures, JHEP

Self-duality of the D1-D5 near-horizon

We explore fermionic T-duality and self-duality in the geometry AdS3 x S3 x T4 in type IIB supergravity. We explicitly construct the Killing spinors and the fermionic T-duality isometries and show that the geometry is self-dual under a combination of two bosonic AdS3 T-dualities, four fermionic T-dualities and either two additional T-dualities along T4 or two T-dualities along S3. In addition, we show that the presence of a B-field acts as an obstacle to self-duality, a property attributable to S- duality and fermionic T-duality not commuting. Finally, we argue that fermionic T-duality may be extended to CY2 = K3, a setting where we cannot explicitly construct the Killing spinors.Comment: 24 pages, references added, changes made to reinforce the point that S-duality and fermionic T-duality generically do not commute, version accepted to JHE