58 research outputs found

    Development in Web-based Laboratory Sessions

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    The laboratory experiments can help the undergraduate students to gain a better understanding the theoretical problem. This paper proposes an educational tool made up a user-friendly interface controlling experimental boards and instrumentation device with a new approach based on FieldPointTM module and the web publishing tool of the LabVIEW. The proposed system allows students to improve their knowledge in the field of optical sensing devices, virtual instrumentation, data acquisition systems, and signal processing

    Human limbal fibroblast-like stem cells induce immune-tolerance in autoreactive T lymphocytes from female patients with Hashimoto\u2019s thyroiditis

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    Abstract Background: Due to their \u201cnatural immune privilege\u201d and immunoregulatory properties human fibroblast-like limbal stem cells (f-LSCs) have acquired great interest as a potential tool for achieving immunotolerance. Hashimoto\u2019s thyroiditis (HT) is the most common thyroid autoimmune disease and cause of hypothyroidism. To date, conventional hormone replacement therapy and unspecific immunosuppressive regimens cannot provide a definitive cure for HT subjects. We explored the immunosuppressant potential of human f-LSCs on circulating lymphomonocytes (PBMCs) collected from healthy donors and female HT patients. Methods: We assessed the immunophenotyping of f-LSCs, both untreated and after 48 h of proinflammatory cytokine exposure, by means of quantitative reverse-transcription polymerase chain reaction (qRT-PCR) and flow cytometry. The immunosuppressant effects of f-LSCs on healthy activated PBMCs were investigated in cell-cell contact and transwell settings through cell cycle assay, acridine orange staining, and caspase-3 detection. We also studied T-cell responses and possible Treg conversion by means of flow cytometry. Functional assays were conducted in activated HT lymphocytes cocultured with f-LSCs after carboxyfluorescein succinimidyl ester labeling and intracellular detection of pro- and antiinflammatory cytokines. Results: The hypo-immunogenicity of the f-LSC population depended on both cell contact and soluble factors produced, as well as the undetectable expression of all those molecules required to fully activate T lymphocytes. Following exposure to Th1 cytokines, f-LSCs augmented expression of programmed death-ligand 1 and 2 (PDL-1 and -2), indoleamine-pyrrole-2,3-dioxygenase (IDO), interleukin (IL)-6, and monocyte chemotactic protein 1 (MCP-1) while maintaining their negative phenotype for major histocompatibility (MHC) class II and costimulatory molecules. During coculture, f-LSCs suppressed up to 40% of proliferation in healthy activated PBMCs, arrested them in the G0/G1 cell cycle phase without inducing apoptosis cascade, inverted the CD4/CD8 ratio, and promoted sustained expression of the immunomodulator marker CD69. Under coculture conditions the Th imbalance of autoreactive T cells from female HT patients was fully restored. Conclusions: Our study describes an in vitro coculture system able to prevent inappropriate activation of autoreactive T lymphocytes of female HT patients and to generate a tolerogenic environment even in an inflammatory background. Further investigations are necessary to establish whether this stem cell-based therapy approach in HT could avoid lifetime hormone replacement therapy by inducing T-cell education

    Light-sheet microscopy for everyone? Experience of building an OpenSPIM to study flatworm development.

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    Background: Selective plane illumination microscopy (SPIM a type of light-sheet microscopy) involves focusing a thin sheet of laser light through a specimen at right angles to the objective lens. As only the thin section of the specimen at the focal plane of the lens is illuminated, out of focus light is naturally absent and toxicity due to light (phototoxicity) is greatly reduced enabling longer term live imaging. OpenSPIM is an open access platform (Pitrone et al. 2013 and OpenSPIM.org) created to give new users step-by-step instructions on building a basic configuration of a SPIM microscope, which can in principle be adapted and upgraded to each laboratory’s own requirements and budget. Here we describe our own experience with the process of designing, building, configuring and using an OpenSPIM for our research into the early development of the polyclad flatworm Maritigrella crozieri – a non-model animal. Results: Our OpenSPIM builds on the standard design with the addition of two colour laser illumination for simultaneous detection of two probes/molecules and dual sided illumination, which provides more even signal intensity across a specimen. Our OpenSPIM provides high resolution 3d images and time lapse recordings, and we demonstrate the use of two colour lasers and the benefits of two color dual-sided imaging. We used our microscope to study the development of the embryo of the polyclad flatworm M. crozieri. The capabilities of our microscope are demonstrated by our ability to record the stereotypical spiral cleavage pattern of M. crozieri with high-speed multi-view time lapse imaging. 3D and 4D (3D + time) reconstruction of early development from these data is possible using image registration and deconvolution tools provided as part of the open source Fiji platform. We discuss our findings on the pros and cons of a self built microscope. Conclusions: We conclude that home-built microscopes, such as an OpenSPIM, together with the available open source software, such as MicroManager and Fiji, make SPIM accessible to anyone interested in having continuous access to their own light-sheet microscope. However, building an OpenSPIM is not without challenges and an open access microscope is a worthwhile, if significant, investment of time and money. Multi-view 4D microscopy is more challenging than we had expected. We hope that our experience gained during this project will help future OpenSPIM users with similar ambitions

    In vitro generation of pancreatic endocrine cells from human adult fibroblast-like limbal stem cells

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    Stem cells might provide unlimited supply of transplantable cells for β-cell replacement therapy in diabetes. The human limbus is a highly specialized region hosting a well-recognized population of epithelial stem cells, which sustain the continuous renewal of the cornea, and the recently identified stromal fibroblast-like stem cells (f-LSCs), with apparent broader plasticity. However, the lack of specific molecular markers for the identification of the multipotent limbal subpopulation has so far limited the investigation of their differentiation potential. In this study we show that the human limbus contains uncommitted cells that could be potentially harnessed for the treatment of diabetes. Fourteen limbal biopsies were obtained from patients undergoing surgery for ocular diseases not involving the conjunctiva or corneal surface. We identified a subpopulation of f-LSCs characterized by robust proliferative capacity, expressing several pluripotent stem cell markers and exhibiting self-renewal ability. We then demonstrated the potential of f-LSCs to differentiate in vitro into functional insulin-secreting cells by developing a four-step differentiation protocol that efficiently directed f-LSCs towards the pancreatic endocrine cell fate. The expression of specific endodermal, pancreatic, islet, and β-cell markers, as well as functional properties of f-LSC-derived insulin-producing cells, were evaluated during differentiation. With our stage-specific approach, up to 77% of f-LSCs eventually differentiated into cells expressing insulin (also assessed as C-peptide) and exhibited phenotypic features of mature β-cells, such as expression of critical transcription factors and presence of secretory granules. Although insulin content was about 160-fold lower than what observed in adult islets, differentiated cells processed ∟98% of their proinsulin content, similar to mature β-cells. Moreover, they responded in vitro in a regulated manner to multiple secretory stimuli, including glucose. In conclusion, f-LSCs represent a possible relevant source of autologous, transplantable, insulin-producing cells that could be tested for the reversal of diabetes

    MULTIPLE PLURIPOTENT STEM CELL MARKERS IN HUMAN ANAPLASTIC THYROID CANCER: THE PUTATIVE UPSTREAM ROLE OF SOX-2

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    Background: Anaplastic Thyroid Carcinoma (ATC) is a rare and aggressive endocrine tumor, with highly undifferentiated morphology. It has been suggested that cancer stem cells (CSCs) might play a central role in ATC. The objectives of this study were the following: 1) to characterize CSCs from ex vivo ATC specimens by investigating the expression of several pluripotent stem cell markers; 2) to evaluate in vitro drug resistance modifications after specific CSC transcription factor switch off. Methods: Ex vivo: eight formalin-fixed, paraffin-embedded ATC specimens were analyzed by RT and qRT-PCR and immunohistochemistry. In vitro: in ATC SW1736 cells the expression levels of OCT-4, NANOG and ABCG2 and the sensitivity to either cisplatin or doxorubicin were evaluated after silencing. Results: OCT-4, KLF4 and SOX2 transcription factors and C-KIT and THY-1 stem surface antigens showed variable up-regulation in all ATC cases. The SW1736 cell line was characterized by a high percentage of stem population (10.4 \ub1 2.1 % of cells were aldehyde dehydrogenase positive) and a high expression of several CSC markers (SOX2, OCT4, NANOG, C-MYC, SSEA4). SOX2 silencing down-regulated OCT-4, NANOG and ABCG2. SOX2 silencing sensitized SW1736 cells, causing a significant cell death increase (1.8 fold) in comparison to control cells with 10 \ub5M cisplatin (93.9\ub13.4% vs. 52.6\ub19.4%, p<0.01) and 2.7 fold with 0.5\ub5M doxorubicin (45.8\ub19.9% vs. 17.1\ub13.4% p<0.01). ABCG2 silencing caused increased cell death with both cisplatin (74.9\ub11.4%) and doxorubicin treatment (74.1\ub10.1%) vs. no-target-treated cells (respectively, 45.8\ub11.0% and 48.6\ub11.0%, p<0.001). Conclusions: The characterization of CSCs in ATC through the analysis of multiple pluripotent stem cell markers might be useful in identifying cells with a stem-like phenotype capable of resisting conventional chemotherapy. In addition, our data demonstrate that SOX2 switch-off through ABCG2 transporter down-regulation has a major role in overcoming CSC chemotherapy resistance

    Combined low densities of FoxP3+ and CD3+ tumor-infiltrating lymphocytes identify stage II colorectal cancer at high risk of progression

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    The densities of CD3+ and CD8+ tumor-infiltrating lymphocytes (TILs), combined with TNM (tumor-node-metastasis) staging, have prognostic value for nonmetastatic colorectal cancer (CRC) patients. We compared the prognostic value of CD3+ and FoxP3+ TILs at the invasive front, TNM classifiers, and microsatellite (MS) status in a trial set of patients with stage II-III CRC (n = 413), by recursive partitioning with a classification and regression tree (CART). Significant prognostic factors and interactions were re-assessed by logistic regression and Cox proportional-hazards modeling in the trial and a validation set (n = 215) of patients with stage II CRC. In the trial set, CART indicated that TIL numbers were of value only in predicting recurrence risk for stage II cancers, where low densities of FoxP3+ TILs ranked first and low densities of CD3+ TILs further stratifiying risk. Multivariate analysis showed that TILs interacted with tumor stage (FoxP3+, P = 0.06; CD3+, P = 0.02) and MS instability (FoxP3+; P = 0.02). In stage II MS-stable cancers, concomitant low densities of both FoxP3+ and CD3+ TILs identified patients with the highest progression risk in the trial (HR 7.24; 95%CI, 3.41-15.4; P < 0.001) and the validation (HR 15.16; 95% IC, 3.43-66.9; P < 0.001) sets. FoxP3+ and CD3+ TIL load in CRC was more informative than other prognostic factors before the cancer progressed to lymph nodes. This prognostic information about TILs, including FoxP3+ cells, suggests that randomized controlled trials might be refined to include interactions between TNM status, molecular classifiers, and post-surgical treatments

    Multi-photon attenuation-compensated light-sheet fluorescence microscopy

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    We thank the UK Engineering and Physical Sciences Research Council for funding (grants EP/P030017/1 and EP/R004854/1), the European Union’s Horizon 2020 Framework Programme (H2020) (675512, BE-OPTICAL), the Danish Council for Independent Research (DFF FTP grant 7017-00021), and the Otto Mønsted Foundation (grant 19-70-0109).Attenuation of optical fields owing to scattering and absorption limits the penetration depth for imaging. Whilst aberration correction may be used, this is difficult to implement over a large field-of-view in heterogeneous tissue. Attenuation-compensation allows tailoring of the maximum lobe of a propagation-invariant light field and promises an increase in depth penetration for imaging. Here we show this promising approach may be implemented in multi-photon (two-photon) light-sheet fluorescence microscopy and, furthermore, can be achieved in a facile manner utilizing a graded neutral density filter, circumventing the need for complex beam shaping apparatus. A “gold standard” system utilizing a spatial light modulator for beam shaping is used to benchmark our implementation. The approach will open up enhanced depth penetration in light-sheet imaging to a wide range of end users.Publisher PDFPeer reviewe

    Development in Web-based Laboratory Sessions

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    The laboratory experiments can help the undergraduate students to gain a better understanding the theoretical problem. This paper proposes an educational tool made up a user-friendly interface controlling experimental boards and instrumentation device with a new approach based on FieldPointTM module and the web publishing tool of the LabVIEW. The proposed system allows students to improve their knowledge in the field of optical sensing devices, virtual instrumentation, data acquisition systems, and signal processing.PublishedComo, Italy2IT. Laboratori sperimentali e analiticiope
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