Publications by authors named "Jonathan Flax"

Sepsis is the most lethal and expensive condition treated in intensive care units. Sepsis survivors frequently suffer long-term cognitive impairment, which has been linked to the breakdown of the blood-brain barrier (BBB) during a sepsis-associated "cytokine storm". Because animal models poorly recapitulate sepsis pathophysiology, human models are needed to understand sepsis-associated brain injury and to develop novel therapeutic strategies.

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Extracellular vesicles (EVs) are particles released from cells that facilitate intercellular communication and have tremendous diagnostic and therapeutic potential. Bulk assays lack the sensitivity to detect rare EV subsets relevant to disease, and while single EV analysis techniques remedy this, they are often undermined by complicated detection schemes and prohibitive instrumentation. To address these issues, a microfluidic technique for EV characterization called "catch and display for liquid biopsy (CAD-LB)" is proposed.

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Extracellular vesicles (EVs) are particles secreted by all cells that carry bioactive cargo and facilitate intercellular communication with roles in normal physiology and disease pathogenesis. EVs have tremendous diagnostic and therapeutic potential and accordingly, the EV field has grown exponentially in recent years. Bulk assays lack the sensitivity to detect rare EV subsets relevant to disease, and while single EV analysis techniques remedy this, they are undermined by complicated detection schemes often coupled with prohibitive instrumentation.

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  • Advanced in vitro tissue chip models, like the modular µSiM (m-µSiM), can help reduce animal testing and support potential "on-chip" clinical trials.
  • The m-µSiM uses easy-to-produce components to allow labs to quickly assemble and adjust designs without needing advanced microfabrication skills.
  • Demonstrations of the m-µSiM's effectiveness include replicating blood-brain barrier properties, ensuring reliable results across different labs, and showcasing its flexibility for various studies by enabling quick modifications and additions.
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  • Sphingosine-1-phosphate (S1P) has varying effects on endothelial barrier function depending on the receptor type it engages, specifically enhancing barriers in HUVECs while destabilizing them in HPMECs.
  • Researchers used various techniques, including flow cytometry and immunofluorescence, to study how S1P interacts with specific receptors (S1PR1 and S1PR3) in two different types of human endothelial cells.
  • The study found that S1P's effect on HPMECs could be exacerbated by inflammatory conditions and involves the Rho-ROCK signaling pathway, indicating that different endothelial cells respond differently to S1P due to varying expression levels of receptors.
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  • The COVID-19 pandemic highlighted the need for better point-of-care (POC) diagnostic tests since initial RT-PCR tests were logistically challenged and couldn't effectively differentiate active infections from residual viral particles.
  • A novel membrane-based sensor called μSiM-DX has been developed to specifically detect intact virions without needing external power, providing rapid results within ten seconds.
  • Early tests of this sensor show 100% specificity and 97% sensitivity for vaccinia virus, with a detection range suitable for viral loads seen in COVID-19 patients.
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To better understand the origin of microplastics in municipal drinking water, we evaluated 50 mL water samples from different stages of the City of Rochester's drinking water production and transport route, from Hemlock Lake to the University of Rochester. We directly filtered samples using silicon nitride nanomembrane filters with precisely patterned slit-shaped pores, capturing many of the smallest particulates (<20 μm) that could be absorbed by the human body. We employed machine learning algorithms to quantify the shapes and quantity of debris at different stages of the water transport process, while automatically segregating out fibrous structures from particulate.

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Extracellular vesicles (EVs) are membrane vesicles secreted by cells and can modulate biological activities by transferring their content following uptake into recipient cells. Labelling of EVs is a commonly used technique for understanding their cellular targeting and biodistribution. A reliable fluorescent technique needs to preserve the size of EVs since changes in size may alter their uptake and biodistribution.

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Membranes have been used extensively for the purification and separation of biological species. A persistent challenge is the purification of species from concentrated feed solutions such as extracellular vesicles (EVs) from biological fluids. We investigated a new method to isolate micro- and nano-scale species termed tangential flow for analyte capture (TFAC), which is an extension of traditional tangential flow filtration (TFF).

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Exosomes are 30-150nM membrane-bound secreted vesicles that are readily isolated from biological fluids such as urine (UEs). Exosomes contain proteins, micro RNA (miRNA), messenger RNA (mRNA), and long non-coding RNA (lncRNA) from their cells of origin. Although miRNA, protein and lncRNA have been isolated from serum as potential biomarkers for benign and malignant disease, it is unknown if lncRNAs in UEs from urothelial bladder cancer (UBC) patients can serve as biomarkers.

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In order to evaluate the phenotypic effects of implanted neural stem cells (NSCs) in the mouse model of Niemann-Pick C (NPC) disease, we injected a well-characterized clone of murine NSCs into the cerebella of neonatal Npc1(-/-) and control mice. The implanted cells survived and were abundant in some regions of the cerebellum. Life span was lengthened in NPC mice with the implanted NSCs.

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Clonal neural cells with stem-like features integrate appropriately into the developing and degenerating central and peripheral nervous system throughout the neuraxis. In response to hypoxic-ischemic (HI) injury, previously engrafted, integrated, and quiescent clonal neural stem cells (NSCs) transiently re-enter the cell cycle, migrate preferentially to the site of ischemia, and differentiate into neurons and oligodendrocytes, the neural cell types typically lost following HI brain injury. They also replenish the supply of immature uncommitted resident stem/progenitor cells.

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