Extrinsic and intrinsic preanalytical variables affecting liquid biopsy in cancer

Liquid biopsy, through isolation and analysis of disease-specific analytes, has evolved as a promising tool for safe and minimally invasive diagnosis and monitoring of tumors. It also has tremendous utility as a companion diagnostic allowing detection of biomarkers in a range of cancers (lung, breast, colon, ovarian, brain). However, clinical implementation and validation remains a challenge. Among other stages of development, preanalytical variables are critical in influencing the downstream cellular and molecular analysis of different analytes. Although considerable progress has been made to address these challenges, a comprehensive assessment of the impact on diagnostic parameters and consensus on standardized and optimized protocols is still lacking. Here, we summarize and critically evaluate key variables in the preanalytical stage, including study population selection, choice of biofluid, sample handling and collection, processing, and storage. There is an unmet need to develop and implement comprehensive preanalytical guidelines on the optimal practices and methodologies

The Liquid Biopsy Consortium: Challenges and opportunities for early cancer detection and monitoring

The emerging field of liquid biopsy stands at the forefront of novel diagnostic strategies for cancer and other diseases. Liquid biopsy allows minimally invasive molecular characterization of cancers for diagnosis, patient stratification to therapy, and longitudinal monitoring. Liquid biopsy strategies include detection and monitoring of circulating tumor cells, cell-free DNA, and extracellular vesicles. In this review, we address the current understanding and the role of existing liquid-biopsy-based modalities in cancer diagnostics and monitoring. We specifically focus on the technical and clinical challenges associated with liquid biopsy and biomarker development being addressed by the Liquid Biopsy Consortium, established through the National Cancer Institute. The Liquid Biopsy Consortium has developed new methods/assays and validated existing methods/technologies to capture and characterize tumor-derived circulating cargo, as well as addressed existing challenges and provided recommendations for advancing biomarker assays

Mise en place de l'extraction liquide-liquide en microsystèmes établir des écoulements segmentés à façon pour optimiser le transfert de masse

National audienceLiquid-liquid extraction is commonly used for radiochemical analysis. When miniaturized, it can benefitfrom the advantages of microfluidic tools i.e. possible coupling, precise control of the interfacial areabetween the aqueous and organic phases, and contact time. A first study, dedicated to liquid-liquidextraction with parallel flows of europium diluted in nitric acid by the N,N′-dimethyl-N,N′-dibutyltetradecylmalonic diamide [1, 2], allowed us to highlight the limitations of parallel flows for aslow chemical system. One way to optimize yields of extraction of the kinetically slow systems is toincrease the specific interfacial area. For this reason, segmented flows formation and characteristicswere investigated, as a function of the physicochemical properties of a biphasic system, flow rates andthe dimensions of a focalized flux junction. In the following, two multiphase models of the droplets sizecorresponding to the transition and dripping regimes were validated and will be used for theoptimization of the specific interfacial area.L’extraction liquide-liquide est couramment utilisée pour les analyses radiochimiques. Miniaturisée,elle peut bénéficier des avantages des outils microfluidiques qui sont la possibilité de réaliser descouplages, le contrôle précis de l’aire interfaciale entre les phases aqueuse et organique en présence,et des temps de contact. Une première étude, dédiée à l’extraction liquide-liquide en flux parallèlesd’europium en milieu nitrique par le N,N’-dimethyl N,N’-dibutyl tetradecylmalonamide [1, 2], a permisde mettre en évidence les limitations des flux parallèles pour un système chimique lent. Une façond’optimiser les rendements d’extraction des systèmes cinétiquement lents est de mettre en œuvre desécoulements permettant d’augmenter l’aire interfaciale spécifique. C’est pourquoi nous étudions laformation d’écoulements segmentés à façon en fonction des propriétés physico-chimiques d’un systèmechimique biphasique, des débits et des dimensions d’une jonction en flux focalisé. L’utilisation de deuxmodèles de calcul des tailles de gouttes en régimes d’écoulements transitoire

Clinical Study Bedside Endoscopic Ultrasound in Critically Ill patients

Background. The aim of this study was to evaluate the role and impact of EUS in the management of critically ill patients. Methods. We retrospectively identified all patients at our institution over a 68-month period in whom bedside inpatient EUS was performed. EUS was considered to have a significant impact if a new diagnosis was established and/or the findings altered subsequent clinical management. Results. Fifteen patients (9 male; mean age 58 ± 15 years) underwent bedside EUS without complications. EUS-FNA (median 4 passes; range 2–7) performed in 12 (80%) demonstrated a malignant mediastinal mass/lymph node (5), pancreatic abscess (1), excluded a pelvic abscess (1), established enlarged gastric folds as benign (1) and excluded malignancy in enlarged mediastinal (1) and porta hepatis adenopathy (1). In two patients, EUS-FNA failed to diagnose mediastinal histoplasmosis (1) and a hemorrhagic pancreatic pseudocyst (1). In three diagnostic exams without FNA, EUS correctly excluded choledocholithaisis (n = 1) and cholangiocarcinoma (1), and found gastric varices successfully thrombosed after previous cyanoacrylate injection (1). EUS was considered to have an impact in 13/15 (87%) patients. Conclusions. In this series, bedside EUS in critically ill patients was technically feasible, safe and had a major impact on the majority of patients. 1

Bedside Endoscopic Ultrasound in Critically Ill patients

Background. The aim of this study was to evaluate the role and impact of EUS in the management of critically ill patients. Methods. We retrospectively identified all patients at our institution over a 68-month period in whom bedside inpatient EUS was performed. EUS was considered to have a significant impact if a new diagnosis was established and/or the findings altered subsequent clinical management. Results. Fifteen patients (9 male; mean age 58 ± 15 years) underwent bedside EUS without complications. EUS-FNA (median 4 passes; range 2–7) performed in 12 (80%) demonstrated a malignant mediastinal mass/lymph node (5), pancreatic abscess (1), excluded a pelvic abscess (1), established enlarged gastric folds as benign (1) and excluded malignancy in enlarged mediastinal (1) and porta hepatis adenopathy (1). In two patients, EUS-FNA failed to diagnose mediastinal histoplasmosis (1) and a hemorrhagic pancreatic pseudocyst (1). In three diagnostic exams without FNA, EUS correctly excluded choledocholithaisis (n = 1) and cholangiocarcinoma (1), and found gastric varices successfully thrombosed after previous cyanoacrylate injection (1). EUS was considered to have an impact in 13/15 (87%) patients. Conclusions. In this series, bedside EUS in critically ill patients was technically feasible, safe and had a major impact on the majority of patients

Relationships between emotional intelligence and sales performance in Kuwait

This study investigates the relationship between emotional intelligence (EI) and Total Sales Performance (TSP), and whether EI contributes to predicting the performance of sales professionals in Kuwait. The sample was 218 sales professionals working for 24 different car dealerships. An ability model of EI was measured using the Assessing Emotions Scale (AES) developed by Schutte et al. (1998) and its Arabic version. The trait model of EI was assessed using the Effective Intelligence Scale (EIS). The findings showed a negative but weak correlation between TSP and the AES and all its subscales. No correlation was found between TSP and the EIS. A weak positive correlation existed between Objective Sales Performance and each of total EIS, Accuracy, and Patience subscales

A parametric integer programming algorithm for bilevel mixed integer programs

We consider discrete bilevel optimization problems where the follower solves an integer program with a fixed number of variables. Using recent results in parametric integer programming, we present polynomial time algorithms for pure and mixed integer bilevel problems. For the mixed integer case where the leader's variables are continuous, our algorithm also detects whether the infimum cost fails to be attained, a difficulty that has been identified but not directly addressed in the literature. In this case it yields a ``better than fully polynomial time'' approximation scheme with running time polynomial in the logarithm of the relative precision. For the pure integer case where the leader's variables are integer, and hence optimal solutions are guaranteed to exist, we present two algorithms which run in polynomial time when the total number of variables is fixed.Comment: 11 page

Utility of EUS following endoscopic polypectomy of high-risk rectosigmoid lesions

BACKGROUND: The utility of endoscopic ultrasound (EUS) compared with standard white light endoscopy (WLE) following recent polypectomy of high-risk colorectal polyps is unknown. OBJECTIVE: To assess the incremental yield of EUS after endoscopic polypectomy of a high-risk rectal lesion. DESIGN: Retrospective cohort. SETTING: Tertiary referral center. MATERIALS AND METHODS: Patients referred for EUS following attempted endoscopic resection of a high-risk rectal neoplasm, defined as a tubulovillous adenoma, tubular adenoma with high-grade dysplasia, carcinoid, carcinoma in-situ or adenocarcinoma (CA). INTERVENTIONS: Sigmoidoscopy ± mucosal biopsy and EUS ± fine-needle aspiration (FNA) to evaluate for: (1) Residual polyp/tumor in the rectal wall or (2) peritumoral adenopathy. MAIN OUTCOME: Sensitivity and specificity for detection of residual neoplasia for WLE ± biopsy (WLE/BX) and EUS ± FNA for cancer (CA group) or benign disease (non-CA group). The incremental yield of EUS defined as: (1) Residual intramural neoplasia not present on WLE ± BX and; (2) abnormal peritumoral adenopathy. RESULTS: A total of 70 patients (mean age 64 ± 11 years, 61% male) with a final diagnosis of CA (n = 38) and non-CA (n = 32) were identified. There was no difference between the sensitivity and specificity of WLE alone (65% and 84%), WLE with biopsy (71% and 95%), and EUS (59% and 84%), for the detection of residual neoplasia (P > 0.05 for all). EUS identified 3 masses missed by WLE, all in the CA group. A malignant (n = 2) or benign (n = 3) node was identified in 5 (13%) CA patients; EUS-FNA in two showed residual malignancy in one and a reactive lymph node (LN) in one. No LNs were identified in the non-CA patients. LIMITATIONS: Retrospective design, incomplete follow-up in some patients. CONCLUSION: Following endoscopic polypectomy of high-risk rectal neoplasia, the incremental yield of EUS compared with WLE/BX for evaluation of residual disease appears limited, especially in patients with benign disease

Performance characteristics of EUS for locoregional evaluation of ampullary lesions

Background The accuracy of EUS in the locoregional assessment of ampullary lesions is unclear. Objectives To compare EUS with ERCP and surgical pathology for the evaluation of intraductal extension and local staging of ampullary lesions. Design Retrospective cohort study. Setting Tertiary-care referral center. Patients All patients who underwent EUS primarily for the evaluation of an ampullary lesion between 1998 and 2012. Intervention EUS. Main Outcome Measurements Comparison of EUS sensitivity/specificity for intraductal and local extension with ERCP and surgical pathology by using the area under the receiver-operating characteristic (AUROC) curves and outcomes of the subgroup referred for endoscopic papillectomy. Results We identified 119 patients who underwent EUS for an ampullary lesion, of whom 99 (83%) had an adenoma or adenocarcinoma. Compared with ERCP (n = 90), the sensitivity/specificity of EUS for any intraductal extension was 56%/97% (AUROC = 0.77; 95% confidence interval [CI], 0.64-0.89). However, when using surgical pathology as the reference (n = 102), the sensitivity/specificity of EUS (80%/93%; AUROC = 0.87; 95% CI, 0.76-0.97) and ERCP (83%/93%; AUROC = 0.88; 95% CI, 0.77-0.99) were comparable. The overall accuracy of EUS for local staging was 90%. Of 58 patients referred for endoscopic papillectomy, complete resection was achieved in 53 (91%); in those having intraductal extension by EUS or ERCP, complete resection was achieved in 4 of 5 (80%) and 4 of 7 (57%), respectively. Limitation Retrospective design. Conclusions EUS and ERCP perform similarly in evaluating intraductal extension of ampullary adenomas. Additionally, EUS is accurate in T-staging ampullary adenocarcinomas. Future prospective studies should evaluate whether EUS can identify characteristics of ampullary lesions that appropriately direct patients to endoscopic or surgical resection. (Gastrointest Endosc 2015;81:380-8.

Murine B Cell Development and Antibody Responses to Model Antigens Are Not Impaired in the Absence of the TNF Receptor GITR

The Glucocorticoid-Induced Tumor necrosis factor Receptor GITR, a member of the tumor necrosis factor receptor superfamily, has been shown to be important in modulating immune responses in the context of T cell immunity. B lymphocytes also express GITR, but a role of GITR in humoral immunity has not been fully explored. To address this question, we performed studies to determine the kinetics of GITR expression on naïve and stimulated B cells and the capacity of B cells to develop and mount antibody responses in GITR−/− mice. Results of our studies indicate that all mature B cells express GITR on the cell surface, albeit at different levels. Expression of GITR on naïve mature B cells is upregulated by BCR signaling, but is counteracted by helper T cell-related factors and other inflammatory signals in vitro. In line with these findings, expression of GITR on germinal center and memory B cells is lower than that on naïve B cells. However, the expression of GITR is strongly upregulated in plasma cells. Despite these differences in GITR expression, the absence of GITR has no effect on T cell-dependent and T cell-independent antibody responses to model antigens in GITR−/− mice, or on B cell activation and proliferation in vitro. GITR deficiency manifests only with a slight reduction of mature B cell numbers and increased turnover of naïve B cells, suggesting that GITR slightly contributes to mature B cell homeostasis. Overall, our data indicate that GITR does not play a significant role in B cell development and antibody responses to T-dependent and independent model antigens within the context of a GITR-deficient genetic background