106 research outputs found

    Remote Non-invasive Stereoscopic Imaging of Blood Vessels: First In-vivo Results of a New Multispectral Contrast Enhancement Technology

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    We describe a contactless optical technique selectively enhancing superficial blood vessels below variously pigmented intact human skin by combining images in different spectral bands. Two CMOS-cameras, with apochromatic lenses and dual-band LED-arrays, simultaneously streamed Left (L) and Right (R) image data to a dual-processor PC. Both cameras captured color images within the visible range (VIS, 400–780 nm) and grey-scale images within the near infrared range (NIR, 910–920 nm) by sequentially switching between LED-array emission bands. Image-size-settings of 1280 × 1024 for VIS & 640 × 512 for NIR produced 12 cycles/s (1 cycle = 1 VIS L&R-pair + 1 NIR L&R-pair). Decreasing image-size-settings (640 × 512 for VIS and 320 × 256 for NIR) increased camera-speed to 25 cycles/s. Contrasts from below the tissue surface were algorithmically distinguished from surface shadows, reflections, etc. Thus blood vessels were selectively enhanced and back-projected into the stereoscopic VIS-color-image using either a 3D-display or conventional shutter glasses. As a first usability reconnaissance we applied this custom-built mobile stereoscopic camera for several clinical settings: • blood withdrawal; • vein inspection in dark skin; • vein detection through iodide; • varicose vein and nevi pigmentosum inspection. Our technique improves blood vessel visualization compared to the naked eye, and supports depth perception

    Lipid-rich Plaques Detected by Near-infrared Spectroscopy Are More Frequently Exposed to High Shear Stress

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    High wall shear stress (WSS) and near-infrared spectroscopy (NIRS) detected lipid-rich plaque (LRP) are both known to be associated with plaque destabilization and future adverse cardiovascular events. However, knowledge of spatial co-localization of LRP and high WSS is lacking. This study investigated the co-localization of LRP based on NIRS and high WSS. Fifty-three patients presenting acute coronary syndrome underwent NIRS-intravascular-ultrasound (NIRS-IVUS) imaging of a non-culprit coronary artery. WSS was obtained using WSS profiling in 3D-reconstructions of the coronary arteries based on fusion of IVUS-segmented lumen and CT-derived 3D-centerline. Thirty-eight vessels were available for final analysis and divided into 0.5 mm/45° sectors. LRP sectors, as identified by NIRS, were more often colocalized with high WSS than sectors without LRP. Moreover, there was a dose-dependent relationship between lipid content and high WSS exposure. This study is a first step in understanding the evolution of LRPs to vulnerable plaques. [Figure not available: see fulltext.

    The Presence of EGFR T790M in TKI-Naïve Lung Cancer Samples of Patients Who Developed a T790M-Positive Relapse on First or Second Generation TKI Is Rare

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    EGFR-mutated non-small cell lung cancer (NSCLC) patients can be effectively treated with tyrosine kinase inhibitors (TKI) but frequently present with an EGFR T790M resistance mutation at relapse. We aimed to screen for T790M in pre-treatment formalin-fixed and paraffin-embedded (FFPE) tissue samples of patients with a confirmed T790M mutation at progression. We analyzed 33 pre-treatment DNA samples of NSCLC patients who progressed upon TKI between 2013 to 2019. To establish storage-time dependent formalin fixation-induced background levels for C>T mutations, we analyzed DNA isolated from archival (stored >1 year, n = 22) and recently generated (stored <1 month, n = 11) FFPE samples and included DNA isolated from white blood cells (WBC) (n = 24) as controls. DNA samples were analyzed by droplet digital (dd)PCR, and positivity was defined by outlier detection according to Grubb's criterion. The T790M background allele frequency levels were 0.160% in DNA isolated from archival-FFPE, 0.100% in fresh FFPE, and 0.035% in WBC. Progression-free survival (PFS) time of the single T790M positive patient was 9 months, while T790M negative patients had a median PFS of 10 months (range 2-27). Proper storage time matched FFPE control samples are essential for reliable detection of T790M mutation at low VAF. The presence of EGFR T790M mutations in pre-TKI samples is rare, even in patients who progressed with EGFR T790M mutations

    Simultaneous Morphological and Flow Imaging Enabled by Megahertz Intravascular Doppler Optical Coherence Tomography

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    We demonstrate three-dimensional intravascular flow imaging compatible with routine clinical image acquisition workflow by means of megahertz (MHz) intravascular Doppler Optical Coherence Tomography (OCT). The OCT system relies on a 1.1 mm diameter motorized imaging catheter and a 1.5 MHz Fourier Domain Mode Locked (FDML) laser. Using a post processing method to compensate the drift of the FDML laser output, we can resolve the Doppler phase shift between two adjoining OCT A-line datasets. By interpretation of the velocity field as measured around the zero phase shift, the flow direction at specific angles can be qualitatively estimated. Imaging experiments were carried out in phantoms, micro channels, and swine coronary artery in vitro at a speed of 600 frames/s. The MHz wavelength sweep rate of the OCT system allows us to directly investigate flow velocity of up to 37.5 cm/s while computationally expensive phase-unwrapping has to be applied to measure such high speed using conventional OCT system. The MHz sweep rate also enables a volumetric Doppler imaging even with a fast pullback at 40 mm/s. We present the first simultaneously recorded 3D morphological images and Doppler flow profiles. Flow pattern estimation and three-dimensional structural reconstruction of entire coronary artery are achieved using a single OCT pullback dataset

    [18F]FDG Uptake in Adipose Tissue Is Not Related to Inflammation in Type 2 Diabetes Mellitus

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    PURPOSE: 2-deoxy-2-[18F]fluoro-D-glucose ([18F]FDG) uptake is a marker of metabolic activity and is therefore used to measure the inflammatory state of several tissues. This radionuclide marker is transported through the cell membrane via glucose transport proteins (GLUTs). The aim of this study is to investigate whether insulin resistance (IR) or inflammation plays a role in [18F]FDG uptake in adipose tissue (AT). PROCEDURES: This study consisted of an in vivo clinical part and an ex vivo mechanistic part. In the clinical part, [18F]FDG uptake in abdominal visceral AT (VAT) and subcutaneous AT (SAT) was determined using PET/CT imaging in 44 patients with early type 2 diabetes mellitus (T2DM) (age 63 [54-66] years, HbA1c [6.3 ± 0.4 %], HOMA-IR 5.1[3.1-8.5]). Plasma levels were measured with ELISA. In the mechanistic part, AT biopsies obtained from 8 patients were ex vivo incubated with [18F]FDG followed by autoradiography. Next, a qRT-PCR analysis was performed to determine GLUT and cytokine mRNA expression levels. Immunohistochemistry was performed to determine CD68+ macrophage infiltration and GLUT4 protein expression in AT. RESULTS: In vivo VAT [18F]FDG uptake in patients with T2DM was inversely correlated with HOMA-IR (r = - 0.32, p = 0.034), and positively related to adiponectin plasma levels (r = 0.43, p = 0.003). Ex vivo [18F]FDG uptake in VAT was not related to CD68+ macrophage infiltration, and IL-1ß and IL-6 mRNA expression levels. Ex vivo VAT [18F]FDG uptake was positively related to GLUT4 (r = 0.83, p = 0.042), inversely to GLUT3 (r = - 0.83, p = 0.042) and not related to GLUT1 mRNA expression levels. CONCLUSIONS: In vivo [18F]FDG uptake in VAT from patients with T2DM is positively correlated with adiponectin levels and inversely with IR. Ex vivo [18F]FDG uptake in AT is associated with GLUT4 expression but not with pro-inflammatory markers. The effect of IR should be taken into account when interpreting data of [18F]FDG uptake as a marker for AT inflammation

    Combined optical coherence tomography and intravascular ultrasound radio frequency data analysis for plaque characterization. Classification accuracy of human coronary plaques in vitro

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    This study was performed to characterize coronary plaque types by optical coherence tomography (OCT) and intravascular ultrasound (IVUS) radiofrequency (RF) data analysis, and to investigate the possibility of error reduction by combining these techniques. Intracoronary imaging methods have greatly enhanced the diagnostic capabilities for the detection of high-risk atherosclerotic plaques. IVUS RF data analysis and OCT are two techniques focusing on plaque morphology and composition. Regions of interest were selected and imaged with OCT and IVUS in 50 sections, from 14 human coronary arteries, sectioned post-mortem from 14 hearts of patients dying of non-cardiovascular causes. Plaques were classified based on IVUS RF data analysis (VH-IVUSTM), OCT and the combination of those. Histology was the benchmark. Imaging with both modalities and coregistered histology was successful in 36 sections. OCT correctly classified 24; VH-IVUS 25, and VH-IVUS/OCT combined, 27 out of 36 cross-sections. Systematic misclassifications in OCT were intimal thickening classified as fibroatheroma in 8 cross-sections. Misclassifications in VH-IVUS were mainly fibroatheroma as intimal thickening in 5 cross-sections. Typical image artifacts were found to affect the interpretation of OCT data, misclassifying intimal thickening as fibroatheroma or thin-cap fibroatheroma. Adding VH-IVUS to OCT reduced the error rate in this study

    The Relation Between Histological, Tumor-Biological and Clinical Parameters in Deep and Superficial Leiomyosarcoma and Leiomyoma

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    Purpose: Leiomyosarcomas (LMS) of deep and superficial tissues were examined to identify prognostic markers explaining their different biological behaviour and to define differences between cutaneous and subcutaneous LMS. LMS and leiomyomas (LM) of the skin were compared to and consistent differences that could aid in the (sometimes difficult) diagnosis

    Cortactin expression assessment improves patient selection for a watchful waiting strategy in pT1cN0-staged oral squamous cell carcinomas with a tumor infiltration depth below 4 mm

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    BACKGROUND: In this feasibility study we aimed to evaluate the value of previously reported molecular tumor biomarkers associated with lymph node metastasis in oral squamous cell carcinoma (OSCC) to optimize neck strategy selection criteria. METHODS: The association between expression of cortactin, cyclin D1, FADD, RAB25, and S100A9 and sentinel lymph node status was evaluated in a series of 87 (cT1‐2N0) patients with OSCC treated with primary resection and SLNB procedure. RESULTS: Tumor infiltration depth and tumor pattern of invasion were independent prognostic markers for SLN status, while none of the tumor makers showed a better prognostic value to replace SLNB as neck staging technique in the total cohort. However, in the subgroup of patients with pT1N0 OSCC, cortactin expression (OR 16.0, 95%CI 2.0–127.9) was associated with SLN classification. CONCLUSIONS: Expression of cortactin is a promising immunohistochemical tumor marker to identify patients at low risk that may not benefit from SLNB or END

    Tudásmenedzsment és a felsőoktatási intézmény, mint vállalat = Knowledge Management and the University as a Company

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    Purpose: ALK rearrangement detection using FISH is the standard test to identify patients with non–small cell lung carcinoma (NSCLC) eligible for treatment with ALK inhibitors. Recently, ALK protein expression in resectable NSCLC showed predictive value. We evaluated tumor response rate and survival after crizotinib treatment of patients with advanced NSCLC with ALK activation using both dichotomous immunohistochemical (IHC) staining and FISH. Experimental Design: Patients with stage IV NSCLC treated with crizotinib were selected. Tumor response was assessed. ALK rearrangements were detected by FISH (Vysis ALK-break-apart FISH-Probe KIT) and IHC [Ventana ALK (D5F3) CDx assay]. Cohorts of patients with ALK-FISH–positive advanced NSCLC from four other hospitals were used for validation. Results: Twenty-nine consecutive patients with ALK-positive advanced NSCLC diagnosed by FISH and/or IHC on small biopsies or fine-needle aspirations (FNA) were treated with ALK inhibitors. All ALK-IHC–positive patients responded to crizotinib except three with primary resistance. No tumor response was observed in 13 ALK-FISH–positive but ALK-IHC–negative patients. This was confirmed in an external cohort of 16 patients. Receiver operator characteristic (ROC) curves for ALK-IHC and ALK-FISH compared with treatment outcome showed that dichotomous ALK-IHC outperforms ALK-FISH [tumor response area under the curve: (AUC), 0.86 vs. 0.64, P ¼ 0.03; progression-free survival (PFS): AUC 0.86 vs. 0.36, P ¼ 0.005; overall survival (OS): AUC, 0.78 vs. 0.41, P ¼ 0.01, respectively]. Conclusions: Dichotomous ALK-IHC is superior to ALK-FISH on small biopsies and FNA to predict tumor response and survival to crizotinib for patients with advanced NSCLC. Our data strongly suggest adapting the guidelines and using dichotomous ALK-IHC as standard companion diagnostic test to select patients with NSCLC who benefit from ALK-targeting therapy
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