139 research outputs found
Modeling the influence of Twitter in reducing and increasing the spread of influenza epidemics
In this paper we present compartmentalized neuron arraying (CNA) microfluidic circuits for the preparation of neuronal networks using minimal cellular inputs (10–100-fold less than existing systems). The approach combines the benefits of microfluidics for precision single cell handling with biomaterial patterning for the long term maintenance of neuronal arrangements. A differential flow principle was used for cell metering and loading along linear arrays. An innovative water masking technique was developed for the inclusion of aligned biomaterial patterns within the microfluidic environment. For patterning primary neurons the technique involved the use of meniscus-pinning micropillars to align a water mask for plasma stencilling a poly-amine coating. The approach was extended for patterning the human SH-SY5Y neuroblastoma cell line using a poly(ethylene glycol) (PEG) back-fill and for dopaminergic LUHMES neuronal precursors by the further addition of a fibronectin coating. The patterning efficiency Epatt was >75% during lengthy in chip culture, with ~85% of the outgrowth channels occupied by neurites. Neurons were also cultured in next generation circuits which enable neurite guidance into all outgrowth channels for the formation of extensive inter-compartment networks. Fluidic isolation protocols were developed for the rapid and sustained treatment of the different cellular and sub-cellular compartments. In summary, this research demonstrates widely applicable microfluidic methods for the construction of compartmentalized brain models with single cell precision. These minimalistic ex vivo tissue constructs pave the way for high throughput experimentation to gain deeper insights into pathological processes such as Alzheimer and Parkinson Diseases, as well as neuronal development and function in health
Long-Term Impact of Cyclosporin Reduction with MMF Treatment in Chronic Allograft Dysfunction: REFERENECE Study 3-Year Follow Up
Calcineurin inhibitor (CNI) toxicity contributes to chronic allograft nephropathy (CAN). In the 2-year, randomized, study, we showed that 50% cyclosporin (CsA) reduction in combination with mycophenolate mofetil (MMF) treatment improves kidney function without increasing the risk for graft rejection/loss. To investigate the long-term effect of this regimen, we conducted a follow up study in 70 kidney transplant patients until 5 years after REFERENCE initiation. The improvement of kidney function was confirmed in the MMF group but not in the control group (CsA group). Four graft losses occurred, 2 in each group (graft survival in the MMF group 95.8% and 90.9% in control group). One death occurred in the control group. There was no statistically significant difference in the occurrence of serious adverse events or acute graft rejections. A limitation is the weak proportion of patient still remaining within the control group. On the other hand, REFERENCE focuses on the CsA regimen while opinions about the tacrolimus ones are still debated. In conclusion, CsA reduction in the presence of MMF treatment seems to maintain kidney function and is well tolerated in the long term
Intravascular hemolysis activates complement via cell-free heme and heme-loaded microvesicles
Chronic kidney disease after liver, cardiac, lung, heart–lung, and hematopoietic stem cell transplant
Patient survival after cardiac, liver, and hematopoietic stem cell transplant (HSCT) is improving; however, this survival is limited by substantial pretransplant and treatment-related toxicities. A major cause of morbidity and mortality after transplant is chronic kidney disease (CKD). Although the majority of CKD after transplant is attributed to the use of calcineurin inhibitors, various other conditions such as thrombotic microangiopathy, nephrotic syndrome, and focal segmental glomerulosclerosis have been described. Though the immunosuppression used for each of the transplant types, cardiac, liver and HSCT is similar, the risk factors for developing CKD and the CKD severity described in patients after transplant vary. As the indications for transplant and the long-term survival improves for these children, so will the burden of CKD. Nephrologists should be involved early in the pretransplant workup of these patients. Transplant physicians and nephrologists will need to work together to identify those patients at risk of developing CKD early to prevent its development and progression to end-stage renal disease
Low incidence of SARS-CoV-2, risk factors of mortality and the course of illness in the French national cohort of dialysis patients
Long-term kidney survival analyses in IgA nephropathy patients under steroids therapy: a case control study
Étude de la prévalence de la consommation de drogues en milieu de travail à partir de l’expérience régionale du Nord-Pas-de-Calais
Facteurs associes aux violences en milieu du travail cas du Chu-campus de Lome (Togo)
En milieu de travail, les mauvaises conditions de travail peuvent générer la violence avec des conséquences physiques et psychologiques entraînant ainsi des coûts pour le travailleur, pour l’entreprise et pour la société. Au CHU Campus, la violence est devenue un sérieux problème menaçant la santé du personnel et les patients ne sont pas satisfaits des prestations. L’objectif de notre étude est de décrire les types de violences et d’identifier les facteurs associés. Il s’agit d’une étude épidémiologique descriptive transversale été menée au CHU Campus de Lomé, de novembre 2005 à avril 2006. Elle a porté sur 110 personnels soignants et non soignants représentatifs de la population hospitalière générale du Togo.Quarante huit pour cent des agents enquêtés ont été victime et/ou témoin de violence au sein du CHU Campus. Les types de violences sont : les agressions verbales (47.0 %), le harcèlement moral (36.4 %), leharcèlement sexuel (27.3 %) et les agressions physiques (6.8 %). Les facteurs les plus souvent associés sont : l’insatisfaction du salaire (84,0%), l’insatisfaction des conditions de travail (80,0 %), l’insuffisancedu matériel de travail (79,0 %), l’exiguïté des salles de travail avec encombrement et surpeuplement (53,0 %), l’effectif réduit des équipes de travail (50,0 %), la non reconnaissance du service rendu (45,0 %) et le cumul de plusieurs tâches à la fois (36,0 %). Les violences existent au CHU Campus de Lomé et sont associées aux mauvaises conditions de travail. Les autorités et les partenaires sociaux doivent prendre des dispositions pour minimiser l’impact des facteurs psycho-sociaux sur les travailleurs. Le problème doit être abordé beaucoup plus en profondeurpour en évaluer l’ampleur en milieu de travail et en rechercher les causes et les facteurs associés
Suppression of auto-fluorescence from high-resolution 3D polymeric architectures fabricated via two-photon polymerization for cell biology applications
Two-photon polymerization (2PP) has provided the field of cell biology with the opportunity to fabricate precisely designed microscaffolds for a wide range of studies, from mechanobiology to in vitro disease modelling. However, a multitude of commercial and in-house developed photosensitive materials employed in 2PP suffers from high auto-fluorescence in multiple regions of the spectrum. In the context of in vitro cell biological studies, this is a major problem since one of the main methods of characterization is fluorescence microscopy of immuno-stained cells. This undesired auto-fluorescence of microscaffolds affects the efficiency of such an analysis as it often overlaps with fluorescent signals of stained cells rendering them indistinguishable from the scaffolds. Here, we propose two effective solutions to suppress this auto-fluorescence and compare them to determine the superiority of one over the other: photo-bleaching with a powerful UV point source and auto-fluorescence quenching via Sudan Black B (SBB). The materials used in this study were all commercially available, namely IP-L, IP-Dip, IP-S, and IP-PDMS. Bleaching was shown to be 61.7–92.5% effective in reducing auto-fluorescence depending on the material. On the other hand, SBB was shown to be 33–95.4% effective. The worst result in presence of SBB (33%) was in combination with IP-PDMS since the adsorption of the material on IP-PDMS was not sufficient to fully quench the auto-fluorescence. However, auto-fluorescence reduction was significantly enhanced when activating the IP-PDMS structures with oxygen plasma for 30 s. Moreover, we performed a cell culture assay using a human neuroblastoma cell line (SH-SY5Y) to prove the effectiveness of both methods in immunofluorescence characterization. SBB presented a lower performance in the study especially in presence of 2PP-fabricated microchannels and microcages, within which the differentiated SH-SY5Y cells migrated and extended their axon-like processes, since the SBB obstructed the fluorescence of the stained cells. Therefore, we concluded that photo-bleaching is the optimal way of auto-fluorescence suppression. In summary, this study provides a systematic comparison to answer one of the most pressing issues in the field of 2PP applied to cell biology and paves the way to a more efficient immunofluorescence characterization of cells cultured within engineered in vitro microenvironments.</p
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