28 research outputs found

    Science communication and concept of risk in bio-tech-sciences: Is it a part of neo-liberalism, or foucaultian bio-politics?

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    In this work a Raman flow cytometer is presented. It consists of a microfluidic device that takes advantages of the basic principles of Raman spectroscopy and flow cytometry. The microfluidic device integrates calibrated microfluidic channels- where the cells can flow one-by-one -, allowing single cell Raman analysis. The microfluidic channel integrates plasmonic nanodimers in a fluidic trapping region. In this way it is possible to perform Enhanced Raman Spectroscopy on single cell. These allow a label-free analysis, providing information about the biochemical content of membrane and cytoplasm of the each cell. Experiments are performed on red blood cells (RBCs), peripheral blood lymphocytes (PBLs) and myelogenous leukemia tumor cells (K562)

    Mechanical Stress Downregulates MHC Class I Expression on Human Cancer Cell Membrane

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    In our body, cells are continuously exposed to physical forces that can regulate different cell functions such as cell proliferation, differentiation and death. In this work, we employed two different strategies to mechanically stress cancer cells. The cancer and healthy cell populations were treated either with mechanical stress delivered by a micropump (fabricated by deep X-ray nanolithography) or by ultrasound wave stimuli. A specific down-regulation of Major Histocompatibility Complex (MHC) class I molecules expression on cancer cell membrane compared to different kinds of healthy cells (fibroblasts, macrophages, dendritic and lymphocyte cells) was observed, stimulating the cells with forces in the range of nano-newton, and pressures between 1 and 10 bar (1 bar = 100.000 Pascal), depending on the devices used. Moreover, Raman spectroscopy analysis, after mechanical treatment, in the range between 700-1800 cm(-1), indicated a relative concentration variation of MHC class I. PCA analysis was also performed to distinguish control and stressed cells within different cell lines. These mechanical induced phenotypic changes increase the tumor immunogenicity, as revealed by the related increased susceptibility to Natural Killer (NK) cells cytotoxic recognition

    RANBP1, a member of the nuclear-cytoplasmic trafficking-regulator complex, is the terminal-striking point of the SGK1-dependent Th17+ pathological differentiation

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    The Th17+ arrangement is critical for orchestrating both innate and acquired immune responses. In this context, the serum and glucocorticoid regulated kinase 1 (SGK1) exerts a key role in the governance of IL-23R-dependent Th17+ maturation, through the phosphorylation-dependent control of FOXO1 localization. Our previous work has shown that some of the SGK1-key functions are dependent on RAN-binding protein 1 (RANBP1), a terminal gene in the nuclear transport regulation. Here, we show that RANBP1, similarly to SGK1, is modulated during Th17+ differentiation and that RANBP1 fluctuations mediate the SGK1-dependent effects on Th17+ maturation. RANBP1, as the final effector of the SGK1 pathway, affects FOXO1 transport from the nucleus to the cytoplasm, thus enabling RORγt activation. In this light, RANBP1 represents the missing piece, in an essential and rate-limiting manner, underlying the Th17+ immune asset

    Iron and Ferritin Modulate MHC Class I Expression and NK Cell Recognition

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    The ability of pathogens to sequester iron from their host cells and proteins affects their virulence. Moreover, iron is required for various innate host defense mechanisms as well as for acquired immune responses. Therefore, intracellular iron concentration may influence the interplay between pathogens and immune system. Here, we investigated whether changes in iron concentrations and intracellular ferritin heavy chain (FTH) abundance may modulate the expression of Major Histocompatibility Complex molecules (MHC), and susceptibility to Natural Killer (NK) cell cytotoxicity. FTH downregulation, either by shRNA transfection or iron chelation, led to MHC surface reduction in primary cancer cells and macrophages. On the contrary, mouse embryonic fibroblasts (MEFs) from NCOA4 null mice accumulated FTH for ferritinophagy impairment and displayed MHC class I cell surface overexpression. Low iron concentration, but not FTH, interfered with IFN-γ receptor signaling, preventing the increase of MHC-class I molecules on the membrane by obstructing STAT1 phosphorylation and nuclear translocation. Finally, iron depletion and FTH downregulation increased the target susceptibility of both primary cancer cells and macrophages to NK cell recognition. In conclusion, the reduction of iron and FTH may influence the expression of MHC class I molecules leading to NK cells activation

    Comparison of Allplexâ„¢ 2019-nCoV and TaqPathâ„¢ COVID-19 Assays

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    The clinical presentation of COVID-19 is non-specific, and to improve and limit the spread of the SARS-CoV-2 virus, an accurate diagnosis with a robust method is needed. A total of 500 nasopharyngeal swab specimens were tested for SARS-CoV-2. Of these, 184 samples were found to be positive with Allplexâ„¢ 2019-nCoV Assay, which is fully automated. All the positive samples were retested with TaqPathâ„¢ COVID-19 CE-IVD RT-PCR Kit (after this, referred to as TaqPathâ„¢ COVID-19), semi-automated. The comparison of RT-qPCR for SARS-CoV-2 genes target points shows only one target point in common, the N gene. Therefore, the N gene was used to compare both assays. We noticed different Ct values between the tests. Therefore, samples were divided into four groups depending to the Ct value results: (1) Ct 35. TaqPathâ„¢ COVID-19 Kit reconfirmed the results obtained from Allplexâ„¢ 2019-nCoV Assay. In conclusion, both the Allplexâ„¢ 2019-nCoV assay and TaqPathâ„¢ COVID-19 tests accurately confirm the diagnosis of SARS-CoV-2 infection. Even if TaqPathâ„¢ COVID-19 has a semi-automated workflow, it does not introduce bias in the diagnostic screening of SARS-CoV-2, and it supports the indirect identification of variants of concern to undergo sequencing

    Comparison of Allplex™ 2019-nCoV and TaqPath™ COVID-19 Assays

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    The clinical presentation of COVID-19 is non-specific, and to improve and limit the spread of the SARS-CoV-2 virus, an accurate diagnosis with a robust method is needed. A total of 500 nasopharyngeal swab specimens were tested for SARS-CoV-2. Of these, 184 samples were found to be positive with Allplex™ 2019-nCoV Assay, which is fully automated. All the positive samples were retested with TaqPath™ COVID-19 CE-IVD RT-PCR Kit (after this, referred to as TaqPath™ COVID-19), semi-automated. The comparison of RT-qPCR for SARS-CoV-2 genes target points shows only one target point in common, the N gene. Therefore, the N gene was used to compare both assays. We noticed different Ct values between the tests. Therefore, samples were divided into four groups depending to the Ct value results: (1) Ct < 25, (2) Ct 25–30, (3) Ct 30–35, (4) Ct > 35. TaqPath™ COVID-19 Kit reconfirmed the results obtained from Allplex™ 2019-nCoV Assay. In conclusion, both the Allplex™ 2019-nCoV assay and TaqPath™ COVID-19 tests accurately confirm the diagnosis of SARS-CoV-2 infection. Even if TaqPath™ COVID-19 has a semi-automated workflow, it does not introduce bias in the diagnostic screening of SARS-CoV-2, and it supports the indirect identification of variants of concern to undergo sequencing

    Silver-based surface enhanced Raman scattering (SERS) substrate fabrication using nanolithography and site selective electroless deposition

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    In this work active SERS (surface enhanced Raman scattering) substrates are obtained by electron beam lithography and site selective electroless deposition technique. The combination of these two techniques allows to obtain well-defined metal structures, with a considerable advantage in Raman signal enhancement and in device reproducibility. The active-substrates are composed of silver, gold or a combination of the two metals, with different nanoparticles characteristics, obtained by varying metal deposition time. Rhodamine 6G was used as probe molecules for SERS experiments, showing that this new active substrate has high sensitivity to SERS response and allows to give Raman scattering also for diluted solutions (10−20 M)

    Validation of GeneFinder COVID-19 Ag Plus Rapid Test and Its Potential Utility to Slowing Infection Waves: A Single-Center Laboratory Evaluation Study

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    Diagnostic laboratory tools are essential to keep everyone safe and track newly emerging variants; on the other hand, “filter” screening tests recognizing positivity are valuable tools to avoid hectic laboratory work that, besides COVID-19, are also part of the routine. Therefore, complementary assays, such as rapid antigen tests (RATs), are essential in controlling and monitoring virus spread within the community, especially in the asymptomatic population. A subset of nasopharyngeal swab specimens resulted in SARS-CoV-2 positive and investigated for genomic characterization were used for RAT validation. RATs were performed immediately after sampling, following the manufacturer’s instructions (reading at 15 min). RT-PCRs were carried out within 24 h of specimens’ collection. Out of 603 patients, 145 (24.05%) tested positive by RT-PCR and RAT and 451 (74.79%) tested negative by both methods; discordant results (RT-PCR+/RAT− or RT-PCR−/RAT+) were obtained in 7 patients (1.16%). RATs’ overall specificity and sensitivity were 96.03% (95%CI: 91.55–98.53%) and 99.78% (95%CI: 98.77–99.99%), respectively, taking RT-PCR as the reference. Overall, RAT negative predictive value was 98.69% (95%CI 97.17–99.40%). The GeneFinder COVID-19 Ag Plus Rapid Test performed well as a screening test for early diagnosis of COVID-19, especially in asymptomatic subjects. The data suggested that patients with RT-PCR-proven COVID-19 testing negative by RAT are unlikely to be infectious. GeneFinder COVID-19 Ag Plus Rapid Test also works on variants of concern (VOC) delta and omicron BA.1 and BA.2
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