265 research outputs found
Detailed examination of lymph nodes improves prognostication in colorectal cancer
Up to 30% of stage II patients with curatively resected colorectal cancer (CRC) will develop disease recurrence. We evaluated whether examination of lymph nodes by multilevel sectioning and immunohistochemical staining can improve prognostication. Lymph nodes (n = 780) from 36 CRC patients who had developed disease recurrence (cases) and 72 patients who showed no recurrence of disease for at least 5 years (controls) were analyzed. Sections of 4 levels at 200-mu m interval were immunohistochemically stained for cytokeratin expression. The first level was analyzed by conventional and automated microscopy, and the 3 following levels were analyzed by automated microscopy for the presence of tumor cells. Overall, cases showed more micrometastases (3 patients) than controls (1 patient). Analysis of a second level led to the additional detection of 1 patient with micrometastases (case) and 1 patient with macrometastasis (case). Examining more levels only led to additional isolated tumor cells, which were equally divided between cases and controls. Likewise, automated microscopy resulted only in detection of additional isolated tumor cells when compared with conventional microscopy. In multivariate analysis, micrometastases [odds ratio (OR) 26.3, 95% confidence interval (CI) 1.9-364.8, p = 0.015], T4 stage (OR 4.8, 95% CI 1.4-16.7, p = 0.013) and number of lymph nodes (OR 0.9, 95% CI 0.8-1.0, p = 0.028) were independent predictors for disease recurrence. Lymph node analysis of 2 levels and immunohistochemical staining add to the detection of macrometastases and micrometastases in CRC. Micrometastases were found to be an independent predictor of disease recurrence. Isolated tumor cells were of no prognostic significance.</p
Nanocolloidal albumin-IRDye 800CW: a near-infrared fluorescent tracer with optimal retention in the sentinel lymph node
Purpose: At present, the only approved fluorescent tracer for clinical near-infrared fluorescence-guided sentinel node (SN) detection is indocyanine green (ICG), but the use of this tracer is limited due to its poor retention in the SN resulting in the detection of higher tier nodes. We describe the development and characterization of a next-generation fluorescent tracer, nanocolloidal albumin-IRDye 800CW that has optimal properties for clinical SN detection Methods: The fluorescent dye IRDye 800CW was covalently coupled to colloidal human serum albumin (HSA) particles present in the labelling kit Nanocoll in a manner compliant with current Good Manufacturing Practice. Characterization of nanocolloidal albumin-IRDye 800CW included determination of conjugation efficiency, purity, stability and particle size. Quantum yield was determined in serum and compared to that of ICG. For in vivo evaluation a lymphogenic metastatic tumour model in rabbits was used. Fluorescence imaging was performed directly after peritumoral injection of nanocolloidal albumin-IRDye 800CW or the reference ICG/HSA (i.e. ICG mixed with HSA), and was repeated after 24 h, after which fluorescent lymph nodes were excised. Results: Conjugation of IRDye 800CW to nanocolloidal albumin was always about 50% efficient and resulted in a stable and pure product without affecting the particle size of the nanocolloidal albumin. The quantum yield of nanocolloidal albumin-IRDye 800CW was similar to that of ICG. In vivo evaluation revealed noninvasive detection of the SN within 5 min of injection of either nanocolloidal albumin-IRDye 800CW or ICG/HSA. No decrease in the fluorescence signal from SN was observed 24 h after injection of the nanocolloidal albumin-IRDye 800CW, while a strong decrease or complete disappearance of the fluorescence signal was seen 24 h after injection of ICG/HSA. Fluorescence-guided SN biopsy was very easy. Conclusion: Nanocolloidal albumin-IRDye 800CW is a promising fluorescent tracer with optimal kinetic features for SN detection. © The Author(s) 2012
Treatment strategies and clinical outcomes in consecutive patients with locally advanced pancreatic cancer:A multicenter prospective cohort
Introduction: Since current studies on locally advanced pancreatic cancer (LAPC) mainly report from single, high-volume centers, it is unclear if outcomes can be translated to daily clinical practice. This study provides treatment strategies and clinical outcomes within a multicenter cohort of unselected patients with LAPC. Materials and methods: Consecutive patients with LAPC according to Dutch Pancreatic Cancer Group criteria, were prospectively included in 14 centers from April 2015 until December 2017. A centralized expert panel reviewed response according to RECIST v1.1 and potential surgical resectability. Primary outcome was median overall survival (mOS), stratified for primary treatment strategy. Results: Overall, 422 patients were included, of whom 77% (n = 326) received chemotherapy. The majority started with FOLFIRINOX (77%, 252/326) with a median of six cycles (IQR 4-10). Gemcitabine monotherapy was given to 13% (41/326) of patients and nab-paclitaxel/gemcitabine to 10% (33/326), with a median of two (IQR 3-5) and three (IQR 3-5) cycles respectively. The mOS of the entire cohort was 10 months (95%CI 9-11). In patients treated with FOLFIRINOX, gemcitabine monotherapy, or nab-paclitaxel/gemcitabine, mOS was 14 (95%CI 13-15), 9 (95%CI 8-10), and 9 months (95%CI 8-10), respectively. A resection was performed in 13% (32/252) of patients after FOLFIRINOX, resulting in a mOS of 23 months (95%CI 12-34). Conclusion: This multicenter unselected cohort of patients with LAPC resulted in a 14 month mOS and a 13% resection rate after FOLFIRINOX. These data put previous results in perspective, enable us to inform patients with more accurate survival numbers and will support decision-making in clinical practice. (C) 2020 The Authors. Published by Elsevier Ltd
The third data release of the Kilo-Degree Survey and associated data products
The Kilo-Degree Survey (KiDS) is an ongoing optical wide-field imaging survey
with the OmegaCAM camera at the VLT Survey Telescope. It aims to image 1500
square degrees in four filters (ugri). The core science driver is mapping the
large-scale matter distribution in the Universe, using weak lensing shear and
photometric redshift measurements. Further science cases include galaxy
evolution, Milky Way structure, detection of high-redshift clusters, and
finding rare sources such as strong lenses and quasars. Here we present the
third public data release (DR3) and several associated data products, adding
further area, homogenized photometric calibration, photometric redshifts and
weak lensing shear measurements to the first two releases. A dedicated pipeline
embedded in the Astro-WISE information system is used for the production of the
main release. Modifications with respect to earlier releases are described in
detail. Photometric redshifts have been derived using both Bayesian template
fitting, and machine-learning techniques. For the weak lensing measurements,
optimized procedures based on the THELI data reduction and lensfit shear
measurement packages are used. In DR3 stacked ugri images, weight maps, masks,
and source lists for 292 new survey tiles (~300 sq.deg) are made available. The
multi-band catalogue, including homogenized photometry and photometric
redshifts, covers the combined DR1, DR2 and DR3 footprint of 440 survey tiles
(447 sq.deg). Limiting magnitudes are typically 24.3, 25.1, 24.9, 23.8 (5 sigma
in a 2 arcsec aperture) in ugri, respectively, and the typical r-band PSF size
is less than 0.7 arcsec. The photometric homogenization scheme ensures accurate
colors and an absolute calibration stable to ~2% for gri and ~3% in u.
Separately released are a weak lensing shear catalogue and photometric
redshifts based on two different machine-learning techniques.Comment: small modifications; 27 pages, 12 figures, accepted for publication
in Astronomy & Astrophysic
Skewed X-inactivation is common in the general female population
X-inactivation is a well-established dosage compensation mechanism ensuring that X-chromosomal genes are expressed at comparable levels in males and females. Skewed X-inactivation is often explained by negative selection of one of the alleles. We demonstrate that imbalanced expression of the paternal and maternal X-chromosomes is common in the general population and that the random nature of the X-inactivation mechanism can be sufficient to explain the imbalance. To this end, we analyzed blood-derived RNA and whole-genome sequencing data from 79 female children and their parents from the Genome of the Netherlands project. We calculated the median ratio of the paternal over total counts at all X-chromosomal heterozygous single-nucleotide variants with coverage ≥10. We identified two individuals where the same X-chromosome was inactivated in all cells. Imbalanced expression of the two X-chromosomes (ratios ≤0.35 or ≥0.65) was observed in nearly 50% of the population. The empirically observed skewing is explained by a theoretical model where X-inactivation takes place in an embryonic stage in which eight cells give rise to the hematopoietic compartment. Genes escaping X-inactivation are expressed from both alleles and therefore demonstrate less skewing than inactivated genes. Using this characteristic, we identified three novel escapee genes (SSR4, REPS2, and SEPT6), but did not find support for many previously reported escapee genes in blood. Our collective data suggest that skewed X-inactivation is common in the general population. This may contribute to manifestation of symptoms in carriers of recessive X-linked disorders. We recommend that X-inactivation results should not be used lightly in the interpretation of X-linked variants
MedShapeNet -- A Large-Scale Dataset of 3D Medical Shapes for Computer Vision
Prior to the deep learning era, shape was commonly used to describe the
objects. Nowadays, state-of-the-art (SOTA) algorithms in medical imaging are
predominantly diverging from computer vision, where voxel grids, meshes, point
clouds, and implicit surface models are used. This is seen from numerous
shape-related publications in premier vision conferences as well as the growing
popularity of ShapeNet (about 51,300 models) and Princeton ModelNet (127,915
models). For the medical domain, we present a large collection of anatomical
shapes (e.g., bones, organs, vessels) and 3D models of surgical instrument,
called MedShapeNet, created to facilitate the translation of data-driven vision
algorithms to medical applications and to adapt SOTA vision algorithms to
medical problems. As a unique feature, we directly model the majority of shapes
on the imaging data of real patients. As of today, MedShapeNet includes 23
dataset with more than 100,000 shapes that are paired with annotations (ground
truth). Our data is freely accessible via a web interface and a Python
application programming interface (API) and can be used for discriminative,
reconstructive, and variational benchmarks as well as various applications in
virtual, augmented, or mixed reality, and 3D printing. Exemplary, we present
use cases in the fields of classification of brain tumors, facial and skull
reconstructions, multi-class anatomy completion, education, and 3D printing. In
future, we will extend the data and improve the interfaces. The project pages
are: https://medshapenet.ikim.nrw/ and
https://github.com/Jianningli/medshapenet-feedbackComment: 16 page
Skewed X-inactivation is common in the general female population
X-inactivation is a well-established dosage compensation mechanism ensuring that X-chromosomal genes are expressed at comparable levels in males and females. Skewed X-inactivation is often explained by negative selection of one of the alleles. We demonstrate that imbalanced expression of the paternal and maternal X-chromosomes is common in the general population and that the random nature of the X-inactivation mechanism can be sufficient to explain the imbalance. To this end, we analyzed blood-derived RNA and whole-genome sequencing data from 79 female children and their parents from the Genome of the Netherlands project. We calculated the median ratio of the paternal over total counts at all X-chromosomal heterozygous single-nucleotide variants with coverage ≥10. We identified two individuals where the same X-chromosome was inactivated in all cells. Imbalanced expression of the two X-chromosomes (ratios ≤0.35 or ≥0.65) was observed in nearly 50% of the population. The empirically observed skewing is explained by a theoretical model where X-inactivation takes place in an embryonic stage in which eight cells give rise to the hematopoietic compartment. Genes escaping X-inactivation are expressed from both alleles and therefore demonstrate less skewing than inactivated genes. Using this characteristic, we identified three novel escapee genes (SSR4, REPS2, and SEPT6), but did not find support for many previously reported escapee genes in blood. Our collective data suggest that skewed X-inactivation is common in the general population. This may contribute to manifestation of symptoms in carriers of recessive X-linked disorders. We recommend that X-inactivation results should not be used lightly in the interpretation of X-linked variants
Functional specialization and dynamic resource allocation in visual cortex
We studied the spatiotemporal characteristics of cortical activity in early visual areas and the fusiform gyri (FG) by means of magnetoencephalography (MEG). Subjects performed a visual classification task, in which letters and visually similar pseudoletters were presented in different surrounds and under different task demands. The stimuli appeared in a cued half of the visual field (VF). We observed prestimulus effects on amplitudes in V1 and Cuneus relating to VF and task demands, suggesting a combination of active anticipation and specialized routing of activity in visual processing. Amplitudes in the right FG between 150 and 350 ms after stimulus onset reflected task demands, while those in the left FG between 300 and 400 ms showed selectivity for graphemes. The contrasting stimulus-evoked effects in the right and left FG show that the former area is sensitive to task demands irrespective of stimulus content, whereas the left FG is sensitive to stimulus content irrespectively of task demand
Ioannides, “Functional specialization and dynamic resource allocation in visual cortex
Abstract: We studied the spatiotemporal characteristics of cortical activity in early visual areas and the fusiform gyri (FG) by means of magnetoencephalography (MEG). Subjects performed a visual classification task, in which letters and visually similar pseudoletters were presented in different surrounds and under different task demands. The stimuli appeared in a cued half of the visual field (VF). We observed prestimulus effects on amplitudes in V1 and Cuneus relating to VF and task demands, suggesting a combination of active anticipation and specialized routing of activity in visual processing. Amplitudes in the right FG between 150 and 350 ms after stimulus onset reflected task demands, while those in the left FG between 300 and 400 ms showed selectivity for graphemes. The contrasting stimulus-evoked effects in the right and left FG show that the former area is sensitive to task demands irrespective of stimulus content, whereas the left FG is sensitive to stimulus content irrespectively of task demand. Hum Brain Mapp 31:1-13
The “Mosaic Stage” in Amodal Completion as Characterized by Magnetoencephalography Responses
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