Heterogeneous Specimens Research Articles

Lactose-Functionalized Gold Nanorods for Sensitive and Rapid Serological Diagnosis of Cancer.

Timely and accurate diagnosis of cancer is crucial to cancer treatment. However, serological diagnosis of cancer still faces great challenge because the conventional methodology based on the enzyme-linked immune sorbent assay (ELISA) is costly, time-consuming, and complicated, involving multiple steps. Herein, lactose-functionalized gold nanorods (Lac-GNRs) are fabricated as efficient biosensors to detect cancerous conditions based on the unique surface plasmon resonance properties of GNRs and high specificity of lactose to the galectin-1 cancer biomarker. A trace concentration of galectin-1 as small as 10(-13) M can be detected by Lac-GNRs. The comparative study among BSA, galectin-3, and galectin-1 demonstrates the good specificity of Lac-GNRs to galectin-1 either in aqueous solutions or in the complex and heterogeneous serum specimens. Clinical tests show that the Lac-GNRs biosensors can readily distinguish the serums of cancer patients from those of healthy persons simply by using a microplate reader or even direct visual observation. The Lac-GNRs biosensing platform is highly efficient and easy to use and have great potential in rapid screening of cancer patients.

Tearing resistance of heterogeneous interface region of a dissimilar metal weld characterised with sub-sized single edge bend specimens

Determination of tearing resistance of heterogeneous dissimilar metal welds (DMW) that are critical structures of pipes in nuclear power plants (NPPs) is important in assessment of the structural integrity. Currently, tearing resistance of heterogeneous materials is determined by standards developed for homogeneous materials. The fracture behaviour of heterogeneous materials differs from fracture behaviour of homogeneous materials. Thus standards developed for homogeneous materials are not necessary directly applicable to heterogeneous materials. To develop a standard for heterogeneous materials the current level of knowledge of fracture behaviour in heterogeneous specimens needs to be increased. To enhance the knowledge of fracture in heterogeneous materials tearing resistance of 10×10×55 mm3 and 10×20×100 mm3 single edge bend (SE(B)) specimens extracted from a NPP ferrite-austenite DMW were measured. The specimens were extracted at three different crack locations in a region close to the fusion line between ferritic steel and weld metal of the DMW. As tearing resistance curves of the two specimen geometries are compared toughness and scatter varies, which can be explained by differing crack location with respect to the fusion line. However, the effect of crack location on tearing resistance was not microstructurally quantified, but the qualitative analysis of crack location done in this work implies that a standard developed for heterogeneous materials shall contain guidelines on characterisation of crack location.

Hydrogel microstructure live-cell array for multiplexed analyses of cancer stem cells, tumor heterogeneity and differential drug response at single-element resolution.

Specific phenotypic subpopulations of cancer stem cells (CSCs) are responsible for tumor development, production of heterogeneous differentiated tumor mass, metastasis, and resistance to therapies. The development of therapeutic approaches based on targeting rare CSCs has been limited partially due to the lack of appropriate experimental models and measurement approaches. The current study presents new tools and methodologies based on a hydrogel microstructure array (HMA) for identification and multiplex analyses of CSCs. Low-melt agarose integrated with type I collagen, a major component of the extracellular matrix (ECM), was used to form a solid hydrogel array with natural non-adhesive characteristics and high optical quality. The array contained thousands of individual pyramidal shaped, nanoliter-volume micro-chambers (MCs), allowing concomitant generation and measurement of large populations of free-floating CSC spheroids from single cells, each in an individual micro-chamber (MC). The optical live cell platform, based on an imaging plate patterned with HMA, was validated using CSC-enriched prostate and colon cancer cell lines. The HMA methodology and quantitative image analysis at single-element resolution clearly demonstrates several levels of tumor cell heterogeneity, including morphological and phenotypic variability, differences in proliferation capacity and in drug response. Moreover, the system facilitates real-time examination of single stem cell (SC) fate, as well as drug-induced alteration in expression of stemness markers. The technology may be applicable in personalized cancer treatment, including multiplex ex vivo analysis of heterogeneous patient-derived tumor specimens, precise detection and characterization of potentially dangerous cell phenotypes, and for representative evaluation of drug sensitivity of CSCs and other types of tumor cells.

The Special Features of the Deformation Behavior of an Ultrafine-Grained Aluminum Alloy of the Al–Mg–Li System at Room Temperature

539.52:536.33 The special features of the deformation behavior of an ultrafine-grained aluminum alloy produced by severe plastic deformation are investigated. Unlike ultrafine-grained pure aluminum, the second-phase particles precipitated in the bulk and at the grain boundaries of the alloy are shown to hinder the development of grain boundary sliding and plastic strain localization. This increases the length of the strain hardening stage and uniformity of elongation of a heterogeneous aluminum alloy specimen as compared to pure aluminum.

Numerical analysis of strength mismatch effect on stress field in Charpy specimen

The influence of strength mismatch adjacent to the V-notch in Charpy specimen on stress field has been numerically analyzed with a 3D finite element method. It is found that the softer material adjacent to the V-notch provides a “shielding effect” from high-speed straining introduced by impact loading. As this leads to reduction in flow stress ahead of the V-notch, lower opening stress compared with homogeneous specimen is found in the case of the V-notch within the harder material in heterogeneous specimen. By contrast, in the case of the V-notch within the softer material, plastic strain is concentrated near the V-notch and the opening stress is elevated by constraint due to hard material adjacent to the V-notch. The Charpy impact test was conducted with the Charpy specimen extracted from the clad steel consisted of low- and high-strength steels in order to investigate the strength mismatch effect Charpy absorbed energy KV. It is found that KV value is affected by strength mismatch adjacent to the V-notch and the Weibull stress criterion can be applied to the quantitative evaluation of the strength mismatch effect on KV.

On the contact interfaces in sonic composites

AbstractThe paper analyses the effect of normal contact with friction on the generation of full band‐gaps in sonic composites. The behavior of contact interfaces are computed by using LISA (local interaction simulation approach). LISA is an efficient tool for numerical simulation of the acoustic wave propagation in heterogeneous material specimens, in particular those with contact interfaces between different materials, like in sonic composites. (© 2014 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Abstract 1892: Development of a clinical targeted next generation sequencing test for challenging formalin-fixed paraffin-embedded (FFPE) cancer samples

Abstract Introduction: There is an urgent need for deep targeted sequencing for detection of varieties of somatic aberrations, including single nucleotide variants (SNV), insertions/deletions (indels), loss of heterozygosity (LOH), and copy number variants (CNV) in heterogeneous FFPE cancer patient specimens. We have developed a Next Generation Sequencing (NGS)-based assay for deep sequencing of a number of selected oncogenes and tumor suppressor genes for testing of clinical breast cancer samples. The panel includes those genes, which are commonly mutated in cancers (e.g. breast and ovarian cancer), based on The Cancer Genome Atlas studies and are potentially indicative of responses to experimental compounds undergoing clinical trials. Importantly, the assay can be used in FFPE samples which pose challenges because of high variability in quality and often suboptimal quantities. Methods: To minimize FFPE sample input requirement, we optimized multiple assay steps. DNA was extracted from macrodissected FFPE tissue, and randomly fragmented. The DNA library was constructed and subject to target capture and enrichment before being sequenced on the Illumina MiSeq® systems. To analytically qualify the assays, we tested well-characterized cell lines and reference HapMap cell lines. Furthermore, to confirm the performance of the NGS results in clinical FFPE samples, we compared the results generated using orthogonal methodologies, e.g. SNVs using a custom Ion AmpliSeq™ panel (Life Technologies) on Ion Personal Genome Machine® (PGM), or CNVs using real-time PCR assays or custom Nanostring nCounter® CNV assays (NanoString Technologies). To establish the lower limit of detection, we used mixed DNA samples from FFPE cell lines and from HapMap DNA and further tested Horizon FFPE reference DNA containing mutations at defined allele frequencies. Results: For FFPE DNA extraction, we selected Cobas® FFPE kit (Roche), and Maxwell® CSC DNA FFPE kit (Promega) for higher yield and better purity. For library construction, we chose a KAPA streamlined library preparation kit. For target capture, we used custom xGEN® DNA probes (Integrated DNA Technologies) for improved flexibility in assay optimization, reduced reagent cost, and minimizing batch-to-batch variability. We were able to detect SNVs for >99% of exons selected down to a 5% sensitivity level using about 100 ng FFPE DNA input. Indels, CNV and LOH could also be detected reliably. Conclusions: We developed a targeted NGS assay that could be used in clinical trials and meets the dual challenge of limited DNA amounts and/or variable quality often associated with FFPE clinical specimens and the detection of low level mutations. Considering the recent recognition of Illumina NGS platform by FDA, this approach can represent a path forward to assist in cancer patient assessment, clinical trial recruitment and care. Citation Format: Wenge Shi, Christine Chin, Tingdong Tang, Loretta Hipolito, Preethi Srinivasan, Derek Chiang, David Peng, Emmanuelle Di Tomaso, Shabnam Tangri, Jelveh Lameh, Reinhold Pollner. Development of a clinical targeted next generation sequencing test for challenging formalin-fixed paraffin-embedded (FFPE) cancer samples. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 1892. doi:10.1158/1538-7445.AM2014-1892

Estimation of state and properties of various-scale geomechanical objects using solutions of inverse problems

The authors comment on features of formulation and structure of input data for the inverse problems used in rock mechanics to estimate state and properties of natural and anthropogenic objects at various spatial scales. The article gives examples of using solutions of inverse problems in coal bed degassing monitoring, based on data on changes of pressure in hydraulic props in the overlying bed, and in assessment of deformation parameters of inclusions, based on data of uniaxial compression tests of artificial heterogeneous specimens.

Determination of mechanical properties of spatially heterogeneous breast tissue specimens using contact mode atomic force microscopy (AFM).

This paper outlines a comprehensive parametric approach for quantifying mechanical properties of spatially heterogeneous thin biological specimens such as human breast tissue using contact-mode Atomic Force Microscopy. Using inverse finite element (FE) analysis of spherical nanoindentation, the force response from hyperelastic material models is compared with the predicted force response from existing analytical contact models, and a sensitivity study is carried out to assess uniqueness of the inverse FE solution. Furthermore, an automation strategy is proposed to analyze AFM force curves with varying levels of material nonlinearity with minimal user intervention. Implementation of our approach on an elastic map acquired from raster AFM indentation of breast tissue specimens indicates that a judicious combination of analytical and numerical techniques allow more accurate interpretation of AFM indentation data compared to relying on purely analytical contact models, while keeping the computational cost associated an inverse FE solution with reasonable limits. The results reported in this study have several implications in performing unsupervised data analysis on AFM indentation measurements on a wide variety of heterogeneous biomaterials.

A knowledge-based system for discovering ecological interactions in biodiversity data-stores of heterogeneous specimen-records: A case-study of flower-visiting ecology

We modeled expert knowledge of arthropod flower-visiting behavioral ecology and represented this in an event-centric domain ontology, which we describe along with the ontology construction process. Two smaller domain ontologies were created to represent expert knowledge of known flower-visiting insect groups and expert knowledge of the flower-visiting behavioral ecology of Rediviva bees. Two application ontologies were designed, which, together with the domain ontologies, constituted the ontology framework of a prototype semantic enrichment and mediation system that we designed and implemented to improve semantic interoperability between flower-visiting data-stores. We describe and evaluate the system implementation in a case-study of three flower-visiting data-stores, and we discuss the system's scalability, extension and potential impact. We demonstrate how the system is able to dynamically extract complex ecological interactions from heterogeneous specimen data-stores. The conceptual stance and modeling approach are potentially of general use in representing knowledge of animal behavior and ecological interactions, and in engineering semantic interoperability between data-stores containing behavioral ecology data.

1020-LBP: A system for high-throughput library preparation allows high-resolution HLA typing using next-generation sequencing

Aim The most widely used platform for HLA typing, capillary electrophoresis-based Sanger sequencing technology, does not scale with the number of regions and samples required in complex study designs when compared to next-generation sequencing (NGS) platforms. Here we describe a high-throughput system under development for high-resolution HLA typing capable of generating libraries for NGS using 192 samples and 24 different target specific assays in less than eight hours in run time and 60 minutes in hands-on time. Methods The new Access Array™ HT System is composed of the IFC Controller AXHT, FC1™ thermal cycler, and the 192.24 Access Array™ IFC. The IFC contains 4,608 chambers of 11 nL volume each where amplification reaction takes place. To test the performance of this new system, primers targeting exons 2 and 3 of HLA-A, -B, -C, -DRB1, -DQB1, -DPB1 were used to amplify 192 genomic DNA samples previously typed. Sample barcodes and sequencer-specific tags were added to the amplicons during chip amplification step. After amplification, library was prepared for sequencing. Results Eight 192.24 Access Array™ IFCs were used to prepare libraries for NGS. The first library tested DNA input concentrations of 5, 10, and 20 ng/ μ L DNA. The success rate achieved was of 82.5%, 95.3%, and 95.7% respectively, with 100% concordant typing. Additional libraries prepared using 10 ng/ μ L of DNA resulted in 100% concordant typing for 96% or more of all 2,172 loci tested. These results obtained are the first set of data using the platform under development and will improve with platform and primer design optimization. Conclusions The Access Array™ HT System has proven to be a reliable and efficient system to generate libraries for HLA typing, reaching 100% concordance for over 95% of the loci tested. This system fits the needs of an evolving field where typing a large number of samples accurately, at low cost and short turnaround time, is necessary to effectively test genetically heterogeneous specimens.

Introducing the 2014 JALA Ten Honorees

Introducing the 2014 JALA Ten Honorees

Application of SNP Microarrays to the Genome-Wide Analysis of Chromosomal Instability in Premalignant Airway Lesions

Chromosomal instability is central to the process of carcinogenesis. The genome-wide detection of somatic chromosomal alterations (SCA) in small premalignant lesions remains challenging because sample heterogeneity dilutes the aberrant cell information. To overcome this hurdle, we focused on the B allele frequency data from single-nucleotide polymorphism microarrays (SNP arrays). The difference of allelic fractions between paired tumor and normal samples from the same patient (delta-θ) provides a simple but sensitive detection of SCA in the affected tissue. We applied the delta-θ approach to small, heterogeneous clinical specimens, including endobronchial biopsies and brushings. Regions identified by delta-θ were validated by FISH and quantitative PCR in heterogeneous samples. Distinctive genomic variations were successfully detected across the whole genome in all invasive cancer cases (6 of 6), carcinoma in situ (3 of 3), and high-grade dysplasia (severe or moderate; 3 of 11). Not only well-described SCAs in lung squamous cell carcinoma, but also several novel chromosomal alterations were frequently found across the preinvasive dysplastic cases. Within these novel regions, losses of putative tumor suppressors (RNF20 and SSBP2) and an amplification of RASGRP3 gene with oncogenic activity were observed. Widespread sampling of the airway during bronchoscopy demonstrated that field cancerization reflected by SCAs at multiple sites was detectable. SNP arrays combined with delta-θ analysis can detect SCAs in heterogeneous clinical sample and expand our ability to assess genomic instability in the airway epithelium as a biomarker of lung cancer risk.

Tumor Heterogeneity Revealed byKRAS,BRAF, andPIK3CAPyrosequencing:KRASandPIK3CAIntratumor Mutation Profile Differences and Their Therapeutic Implications

Current clinical problems in colorectal cancer (CRC) diagnostics and therapeutics include the disease complexity, tumor heterogeneity, and resistance to targeted therapeutics. In the present study, we examined 171 CRC adenocarcinomas from Greek patients undergoing surgery for CRC to determine the frequency of KRAS, BRAF, and PIK3CA point mutations from different areas of tumors in heterogeneous specimens. Ninety two out of 171 (53.8%) patients were found to bear a KRAS mutation in codons 12/13. Of the 126 mutations found, 57.9% (73/126) were c.38G>A mutations (p.G13D) and 22.2% (28/126) were c.35G>T (p.G12V). Remarkably, RAS mutations in both codons 12 and 13 were recorded in the same tumor by pyrosequencing. Moreover, differences in KRAS mutations between tumor center and periphery revealed tumor heterogeneity in 50.7% of the specimens. BRAF c.1799T>A (V600E) mutations were moderately detected in 4/171 (2.3%) specimens, whereas most PIK3CA mutations were revealed by pyrosequencing 6/171 (3.5%). Remarkable tumor heterogeneity is revealed, where double mutations of KRAS in the same tumor and different KRAS mutation status between tumor core and margin are detected with high frequency. It is expected that these findings will have a major impact in cancer diagnosis and personalized therapies.

Delamination tests on CFRP-reinforced masonry pillars: Optical monitoring and mechanical modeling

In this methodological study, delamination phenomena of Carbon Fiber Reinforced Polymer (CFRP) strips from masonry pillars were investigated on the basis of single-lap shear tests. The masonry pillar considered in this case was constituted of three historical bricks, derived from a XVII century rural building. The bricks were bonded by a high strength mortar recently proposed for the restoration process. To follow the specimen response up to collapse, the test was controlled by a clip gauge located at the anchorage of the reinforcement strip. The conventional experimental information, concerning the overall reaction force and relative displacements provided by point sensors (LVDTs and clip gauge), were herein enriched with no-contact, kinematic full-field measurements provided by 2D Digital Image Correlation (2D DIC). Special care was devoted to improve the precision of the optical measurement, which included correction of the effects owing to the lens distortion and to lack of coplanarity between the camera sensor and the monitored flat surface. The overall accuracy was assessed through laboratory benchmarking tests. Moreover, an advanced three-dimensional mechanical model based on nonlinear finite elements was developed under the simplifying assumption of perfect adhesion. This model was adopted to describe bulk damage inside the heterogeneous specimen and to correlate it to the macroscopic response and surface measurements. Coherence between the above mentioned sources of information and the predictions provided by the advanced finite element model were critically discussed.

Plastic limit load and its application to the fracture toughness testing for heterogeneous single edge notch tension specimens

ABSTRACTThe current investigation pursues the confirmation of the applicability of the limit load solutions in determination of the η factors necessary for fracture toughness testing protocols. The procedure begins with the correct calculation of limit load values in welded single edge notch tension (SE(T)) fracture specimens containing centreline cracks. Hence, the η factor is inferred through the principle of potential energy. Additionally, such results are compared with those obtained from finite element analyses, including strain hardening effects available in the literature. SE(T) specimens subject to pin‐loading display that the η factors are insensitive to the configurational effects and hardening properties. On the other hand, in clamped SE(T) specimens, such effects become meaningful, making its usage in fracture toughness experiments questionable. This work provides an alternative methodology to compute fully plastic proportionality coefficients (η) based on limit load solutions for heterogeneous cracked SE(T) specimens. These analyses also consider the limitations and potentialities of such an approach in experimental measurements of ductile crack growth.

Concurrent spatial mapping of the elasticity of heterogeneous soft materials via a polymer-based microfluidic device

In this paper, built upon a polymer-based microfluidic device, a novel experimental technique called concurrent spatial mapping (CSM) is presented for measuring the spatially-varying elasticity of heterogeneous soft materials. Comprised of a single compliant polymer microstructure and a set of electrolyte-enabled distributed resistive transducers, this device is capable of detecting continuous distributed loads. In this experimental technique, a rigid probe is employed to press a material specimen against the device with precisely controlled displacements, and consequently the spatially-varying elasticity of the specimen translates to continuous distributed loads acting on the device, where continuous distributed loads give rise to continuous deflection of the polymer microstructure and register as discrete resistance changes at the locations of the distributed transducers. Performance characterization is first conducted on the device as a control experiment. Then, CSM is implemented on several heterogeneous and homogeneous polydimethylsiloxane specimens, as well as a rabbit tissue specimen. The associated data analysis is performed on the measured data for extracting the spatially-varying load-deflection relations of these specimens. In conjunction with its dimensions, the extracted spatially-varying load-deflection relations of a specimen result in its spatially-varying elasticity by the related theoretical formula. For the first time, this paper demonstrates the feasibility of using a single polymer-based microfluidic device to concurrently map out the spatially-varying elasticity of heterogeneous soft materials. As a result, CSM will pave the way for efficiently examining biological tissues and cell-seeded engineering scaffolds, while without excluding the interaction among neighboring compositions in such materials.

Stress relaxation measurement of viscoelastic materials using a polymer-based microfluidic device

This paper presents the stress relaxation measurement of viscoelastic materials using a polymer-based microfluidic device. Comprised of a single polymer rectangular microstructure and a set of electrolyte-enabled distributed resistive transducers, this device is capable of detecting continuous distributed dynamic loads. In a measurement, a rigid cylinder probe is utilized to apply a precisely controlled step displacement input to a material specimen on the device, and consequently the spatially varying stress relaxation behavior of the specimen is translated to time-dependent continuous distributed loads acting on the device, where such loads give rise to time-dependent continuous deflection of the polymer microstructure and register as discrete resistance changes at the locations of the transducers. To account for device-to-device fabrication variations, performance characterization is first conducted on a device as a control experiment, and then a specimen is placed on a characterized device for measurement. Several homogeneous and heterogeneous specimens are measured, and the associated data analysis is conducted for extracting the spatially varying Young's relaxation modulus, which is expressed as the Maxwell model with two relaxation times. The results demonstrate the feasibility of using a single polymer-based microfluidic device to map out the spatially varying stress relaxation behavior of viscoelastic materials.

New Methods for ALK Status Diagnosis in Non–Small-Cell Lung Cancer: An Improved ALK Immunohistochemical Assay and a New, Brightfield, Dual ALK IHC–In Situ Hybridization Assay

The demonstration of anaplastic lymphoma kinase (ALK) positivity in non-small-cell lung cancer (NSCLC) has been hindered by the technical complexity and interpretative challenges of fluorescence in situ hybridization methods for detection of ALK gene rearrangement and by the inadequate sensitivity of existing immunohistochemistry (IHC) methods for ALK protein detection. In this study, we sought to increase the sensitivity of ALK IHC detection and to develop a brightfield assay for concurrent detection of ALK protein expression and ALK gene rearrangement. We developed a horseradish peroxidase-based IHC detection system using the novel, nonendogenous hapten 3-hydroxy-2-quinoxaline (HQ) and tyramide. We also developed a dual gene protein ALK assay combining a brightfield break-apart in situ hybridization ALK assay with another sensitive IHC method using the novel, nonendogenous hapten 5-nitro-3-pyrazole. We examined the sensitivity and accuracy of these methods using surgically resected NSCLC cases examined with ALK fluorescence in situ hybridization. The new HQ-tyramide IHC detection system offered readily interpretable staining with substantially greater sensitivity than conventional ALK IHC, and produced heterogeneous and homogeneous patterns of ALK protein staining among ALK-positive NSCLC surgical cases. The new 5-nitro-3-pyrazole-based IHC detection system was similar in ALK detection sensitivity to the HQ-tyramide IHC system and was compatible with the brightfield in situ hybridization assay. The new HQ-tyramide IHC reagent system allows more sensitive assessment of ALK protein status in NSCLC cases. The new ALK gene-protein assay allows the concurrent visualization of ALK gene and ALK protein status in single cells, allowing more accurate ALK status determination even in heterogeneous specimens.

Categorization of aortic aneurysm thrombus morphology by magnetic resonance imaging

BackgroundMagnetic resonance imaging (MRI) has been proposed for qualitative categorization of intraluminal thrombus morphology. We aimed to correlate the qualitative MRI categorization previously described to quantitative measurements of signal intensity and to compare morphological characteristics of intraluminal thrombus specimens to the appearance on magnetic resonance imaging. MethodsThirty-four patients undergoing open surgery for abdominal aortic aneurysm had a preoperative MRI obtained with a 1.5T magnet. Qualitative categorization was performed (blinded and in consensus) and correlated to intraluminal thrombus to muscle signal-intensity ratios. Morphology of intraluminal thrombus specimens collected during surgery were compared to the magnetic resonance imaging categories and specimen weight was correlated to thrombus volume measured on preoperative computer tomography angiography. ResultsBlinded MRI categorization resulted in agreement in 22 out of 34 intraluminal thrombi (Kappa value 0.3, p=0.006). Medians (p=0.004) and distribution (p=0.002) of signal-intensity ratios varied significantly across the three MRI categories obtained by consensus. Heterogeneous and homogenous specimen appearance corresponded to similar appearances on MRI in 78% and 55% respectively, resulting in an overall Kappa=0.4 (p=0.04). Intraluminal thrombus volume and weight correlated well (rs 0.831, p<0.001) with a mean difference of 60g (95% CI 38–80g), without proportional bias. ConclusionQualitative evaluation of intraluminal thrombus morphology based on MRI can be quantified by measuring signal-intensity ratios. Concurrently a fair agreement to blinded qualitative evaluation of thrombus specimens can be obtained. However, the evaluation is impaired by loss of a large proportion of thrombus during sampling.