179 research outputs found

    Comparison of three methods to stabilize bronchoalveolar lavage cells for flowcytometric analysis

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    Background: Flowcytometric analysis of lymphocytes and their subpopulations in bronchoalveolar lavages (BAL) can support the diagnosis of interstitial lung diseases. This analysis should be done within 4 hr after lavage due to rapid cell deterioration. We tested three methods in order to stabilize for at least 28 days the BAL cell populations to allow delayed flowcytometric analysis in order to facilitate external quality assurance (EQA). Methods: We compared an in-house, dual-step stabilization method for BAL cells with results of two different commercial available stabilization reagents: TransFix® and Streck Cell Preservative™. All three methods were compared with native BAL cells as reference. BAL samples from six patients were tested on six occasions following stabilization from 1 to 28 days by flow cytometry. Results: Following stabilization and storage at 4°C, BAL cell suspensions had stable light scatter patterns and lymphocyte subsets. As expected, rapid deterioration of cells was seen with native BAL cells. The stabilized lavages showed more stable counts of WBC and lymphocyte populations with only minor differences found between the three methods. Conclusions: If analysis of the BAL cells is performed more than 24 hr after the lavage, st

    Evaluating the systemic right ventricle by CMR: the importance of consistent and reproducible delineation of the cavity

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    Contains fulltext : 70334.pdf (publisher's version ) (Open Access)BACKGROUND: The method used to delineate the boundary of the right ventricle (RV), relative to the trabeculations and papillary muscles in cardiovascular magnetic resonance (CMR) ventricular volume analysis, may matter more when these structures are hypertrophied than in individuals with normal cardiovascular anatomy. This study aimed to compare two methods of cavity delineation in patients with systemic RV. METHODS: Twenty-nine patients (mean age 34.7 +/- 12.4 years) with a systemic RV (12 with congenitally corrected transposition of the great arteries (ccTGA) and 17 with atrially switched (TGA) underwent CMR. We compared measurements of systemic RV volumes and function using two analysis protocols. The RV trabeculations and papillary muscles were either included in the calculated blood volume, the boundary drawn immediately within the apparently compacted myocardial layer, or they were manually outlined and excluded. RV stroke volume (SV) calculated using each method was compared with corresponding left ventricular (LV) SV. Additionally, we compared the differences in analysis time, and in intra- and inter-observer variability between the two methods. Paired samples t-test was used to test for differences in volumes, function and analysis time between the two methods. Differences in intra- and inter-observer reproducibility were tested using an extension of the Bland-Altman method. RESULTS: The inclusion of trabeculations and papillary muscles in the ventricular volume resulted in higher values for systemic RV end diastolic volume (mean difference 28.7 +/- 10.6 ml, p < 0.001) and for end systolic volume (mean difference 31.0 +/- 11.5 ml, p < 0.001). Values for ejection fraction were significantly lower (mean difference -7.4 +/- 3.9%, p < 0.001) if structures were included. LV SV did not differ significantly from RV SV for both analysis methods (p = NS). Including structures resulted in shorter analysis time (p < 0.001), and showed better inter-observer reproducibility for ejection fraction (p < 0.01). CONCLUSION: The choice of method for systemic RV cavity delineation significantly affected volume measurements, given the CMR acquisition and analysis systems used. We recommend delineation outside the trabeculations for routine clinical measurements of systemic RV volumes as this approach took less time and gave more reproducible measurements

    What is a Macrophyte Patch? Patch Identification in Aquatic Ecosystems and Guidelines for Consistent Delineation

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    Schoelynck J, Creëlle S, Buis K, De Mulder T, Emsens W, Hein T, Meire D, Meire P, Okruszko T, Preiner S, Roldan Gonzalez R, Silinski A, Temmerman S, Troch P, Van Oyen T, Verschoren V, Visser F, Wang C, Wolters J, Folkard A, in press. . Ecohydrology & Hydrobiology. DOI 10.1016/j.ecohyd.2017.10.00

    Procedural justice in punishment systems: Inconsistent punishment procedures have detrimental effects on cooperation

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    The current research examines a moderator who predicts in what situations punishment can have detrimental effects on cooperation. We hypothesized that when a punishment system is perceived as procedurally unfair, people's cooperation level decreases. Results of two experiments indicated that participants cooperated less in a group-based trust game when punishment was inconsistent between persons (i.e. not all group members would be punished for defection) than when punishment was consistent between persons (i.e. any group member who defected would be punished) or when there was no punishment. These effects were mediated by perceived belongingness. The authors conclude that an unfair punishment system leads people to feel marginalized as a group member, and this prompts them to display less cooperation. © 2008 The British Psychological Society

    High-resolution analysis of HLA class I alterations in colorectal cancer

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    BACKGROUND: Previous studies indicate that alterations in Human Leukocyte Antigen (HLA) class I expression are frequent in colorectal tumors. This would suggest serious limitations for immunotherapy-based strategies involving T-cell recognition. Distinct patterns of HLA surface expression might conceal different immune escape mechanisms employed by the tumors and are worth further study. METHOD: We applied four-color multiparameter flow cytometry (FCM), using a large panel of alloantigen-specific anti-HLA-A and -B monoclonal antibodies, to study membranous expression of individual HLA alleles in freshly isolated colorectal cancer cell suspensions from 21 patients. RESULTS: Alterations in HLA class I phenotype were observed in 8 (38%) of the 21 tumors and comprised loss of a single A or B alleles in 4 cases, and loss of all four A and B alleles in the other 4 cases. Seven of these 8 tumors were located on the right side of the colon, and those showing loss of both HLA-A and -B membranous expression were all of the MSI-H phenotype. CONCLUSION: FCM allows the discrimination of complex phenotypes related to the expression of HLA class I. The different patterns of HLA class I expression might underlie different tumor behavior and influence the success rate of immunotherapy

    Алмазные фотоприемники ультрафиолетового диапазона

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    Изготовлены и исследованы планарные алмазные «солнечно-слепые» фотоприемники УФ-диапазона. Приведено теоретическое обоснование принципов работы и экспериментальные параметры фотоприемников в фоторезистивном и фотодиодном режимах

    Content analysis: What are they talking about?

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    Quantitative content analysis is increasingly used to surpass surface level analyses in Computer-Supported Collaborative Learning (e.g., counting messages), but critical reflection on accepted practice has generally not been reported. A review of CSCL conference proceedings revealed a general vagueness in definitions of units of analysis. In general, arguments for choosing a unit were lacking and decisions made while developing the content analysis procedures were not made explicit. In this article, it will be illustrated that the currently accepted practices concerning the ‘unit of meaning’ are not generally applicable to quantitative content analysis of electronic communication. Such analysis is affected by ‘unit boundary overlap’ and contextual constraints having to do with the technology used. The analysis of e-mail communication required a different unit of analysis and segmentation procedure. This procedure proved to be reliable, and the subsequent coding of these units for quantitative analysis yielded satisfactory reliabilities. These findings have implications and recommendations for current content analysis practice in CSCL research

    The Role of Thrombin in Proliferative Vitreoretinopathy

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    PURPOSE. To determine the role of thrombin in the development of proliferative vitreoretinopathy (PVR). METHODS. Vitreous was collected from patients undergoing a vitrectomy (macular holes and puckers, n ¼ 11 [controls]; retinal detachment without PVR development following vitrectomy, n ¼ 15 [RRD1]; retinal detachment with PVR development within 6 months after vitrectomy, n ¼ 11 [RRD2]; and established PVR, n ¼ 14 [PVR]). Thrombin activity in vitreous was determined using a thrombin-specific chromogenic substrate. ARPE-19 cells were stimulated with 83 diluted vitreous samples in the presence and absence of hirudin. The samples were analyzed at t ¼ 0 and t ¼ 24 hours for the presence of 27 cytokines/ chemokines and growth factors using a multiplex approach. In comparable studies, ARPE-19 cells were stimulated for 2 hours, and mRNA expression levels for CCL2, CXCL8, GMCSF, IL6, and PDGFB were determined by real-time quantitative (RQ)-PCR. RESULTS. Thrombin activity was significantly (P &lt; 0.05) higher in vitreous of the PVR group compared to the other groups. Proliferative vitreoretinopathy vitreous stimulated the production of chemokine (C-C motif) ligand (CCL)2, chemokine (C-X-C motif) ligand (CXCL)8, granulocyte-macrophage colony-stimulating factor (GM-CSF), IL-6, and plateletderived growth factor (PDGF)-BB by ARPE-19 to significantly (P &lt; 0.05) higher levels than vitreous from the RRD1 and RRD2 groups. These effects of PVR vitreous were significantly (P &lt; 0.05) reduced by hirudin. These data were confirmed by mRNA studies. CONCLUSIONS. Thrombin activity is increased in vitreous of patients with established PVR and is involved in the activation of proinflammatory and profibrotic pathways in RPE cells. Inhibition of thrombin activity may therefore represent a potential treatment option for proliferative vitreoretinopathy
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