Publications by authors named "Gavrielle Untracht"

High-throughput screening (HTS) three-dimensional (3D) tumor models are a promising approach for cancer drug discovery, as they more accurately replicate cell behavior than two-dimensional (2D) models. However, assessing and comparing current 3D models for drug efficacy remains essential, given the significant influence of cellular conditions on treatment response. To develop mimicking 3D models, we evaluated two HTS 3D models established in 96-well plates with 3D polycaprolactone (PCL) scaffolds fabricated using two distinct methods, resulting in scaffolds with either homogenous or non-homogenous fiber networks.

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Treatment-resistant actinic keratosis (AK) is of concern in clinical practice, often requiring retreatment. Microvascular assessments might help differentiate treatment-resistant from treatment-responsive AKs, enabling targeted treatment. Using dynamic optical coherence tomography, AK vascularization was investigated following daylight photodynamic therapy, comparing treatment-resistant with cleared AKs.

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Article Synopsis
  • Line-field confocal optical coherence tomography (LC-OCT) is a new technique for diagnosing skin cancers like basal cell carcinoma (BCC) and squamous cell carcinoma (SCC), but little is known about how consistently different observers identify specific image markers of these conditions.
  • The study involved six evaluators with varying dermatological imaging experience assessing 75 LC-OCT images to determine the interobserver agreement (IOA) on 10 key image markers related to skin cancers and their precursors.
  • It was found that IOA was highest for markers typically seen in BCC, such as lobules and clefting, while other markers showed lower agreement, particularly those related to the dermal-epidermal junction, indicating
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Article Synopsis
  • * The study involved 47 patients, revealing that D-OCT identified distinct vascular differences between AK grades and photodamaged skin, especially at a depth of 300μm, and showed significant differences in vessel arrangement and patterns across the various grades of AK.
  • * The combined use of D-OCT and dermatoscopy proved effective in differentiating between AK grades, with results indicating increased vascularization and vessel disorganization in higher-grade AK lesions.
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Clinical grading of actinic keratosis (AK) is based on skin surface features, while subclinical alterations are not taken into consideration. Dynamic optical coherence tomography (D-OCT) enables quantification of the skin´s vasculature, potentially helpful to improve the link between clinical and subclinical features. We aimed to compare microvascular characteristics across AK grades using D-OCT with automated vascular analysis.

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Quantitative assessment of retinal microvasculature in optical coherence tomography angiography (OCTA) images is important for studying, diagnosing, monitoring, and guiding the treatment of ocular and systemic diseases. However, the OCTA user community lacks universal and transparent image analysis tools that can be applied to images from a range of OCTA instruments and provide reliable and consistent microvascular metrics from diverse datasets. We present a retinal extension to the OCTA Vascular Analyser (OCTAVA) that addresses the challenges of providing robust, easy-to-use, and transparent analysis of retinal OCTA images.

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The penetration depth of optical coherence tomography (OCT) reaches well beyond conventional microscopy; however, signal reduction with depth leads to rapid degradation of the signal below the noise level. The pursuit of imaging at depth has been largely approached by extinguishing multiple scattering. However, in OCT, multiple scattering substantially contributes to image formation at depth.

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Optical coherence tomography angiography (OCTA) is a non-invasive, high-resolution imaging modality with growing application in dermatology and microvascular assessment. Accepted reference values for OCTA-derived microvascular parameters in skin do not yet exist but need to be established to drive OCTA into the clinic. In this pilot study, we assess a range of OCTA microvascular metrics at rest and after post-occlusive reactive hyperaemia (PORH) in the hands and feet of 52 healthy people and 11 people with well-controlled type 2 diabetes mellitus (T2DM).

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Femoral artery (FA) endothelial function is a promising biomarker of lower extremity vascular health for peripheral artery disease (PAD) prevention and treatment; however, the impact of age on FA endothelial function has not been reported in healthy adults. Therefore, we evaluated the reproducibility and acceptability of flow-mediated dilation (FMD) in the FA and brachial artery (BA) (n = 20) and performed cross-sectional FA- and BA-FMD measurements in healthy non-smokers aged 22−76 years (n = 50). FMD protocols demonstrated similar good reproducibility.

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: diabetes and age are major risk factors for the development of lower extremity peripheral artery disease (PAD). Cocoa flavanol (CF) consumption is associated with lower risk for PAD and improves brachial artery (BA) endothelial function. : to assess if femoral artery (FA) endothelial function and dermal microcirculation are impaired in individuals with type 2 diabetes mellitus (T2DM) and evaluate the acute effect of CF consumption on FA endothelial function.

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Optical coherence tomography angiography (OCTA) performs non-invasive visualization and characterization of microvasculature in research and clinical applications mainly in ophthalmology and dermatology. A wide variety of instruments, imaging protocols, processing methods and metrics have been used to describe the microvasculature, such that comparing different study outcomes is currently not feasible. With the goal of contributing to standardization of OCTA data analysis, we report a user-friendly, open-source toolbox, OCTAVA (OCTA Vascular Analyzer), to automate the pre-processing, segmentation, and quantitative analysis of en face OCTA maximum intensity projection images in a standardized workflow.

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The organization of fibrillar tissue on the micrometer scale carries direct implications for health and disease but remains difficult to assess . Polarization-sensitive optical coherence tomography measures birefringence, which relates to the microscopic arrangement of fibrillar tissue components. Here, we demonstrate a critical improvement in leveraging this contrast mechanism by employing the improved spatial resolution of focus-extended optical coherence microscopy (1.

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Optical tweezers are an invaluable tool for non-contact trapping and micro-manipulation, but their ability to facilitate high-throughput volumetric microrheology of biological samples for mechanobiology research is limited by the precise alignment associated with the excitation and detection of individual bead oscillations. In contrast, radiation pressure from a low-numerical aperture optical beam can apply transversely localized force over an extended depth range. Here we present photonic force optical coherence elastography (PF-OCE), leveraging phase-sensitive interferometric detection to track sub-nanometer oscillations of beads, embedded in viscoelastic hydrogels, induced by modulated radiation pressure.

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