19 research outputs found

    Ceftriaxone-associated biliary pseudolithiasis in children

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    Purpose. Ceftriaxone is known to induce reversible precipitations, known as pseudolithiasis, in the gallbladder and urinary tract. The aim of this study was to investigate the incidence and predisposing factors that contribute to this side effect. Methods. A prospective study was conducted in 156 children admitted for the treatment of various infections with different daily ceftriaxone doses (50 mg/kg, 75 mg/kg, and 100 mg/kg). Sonographic examinations of the gallbladder and urinary tract were performed before treatment on the third and seventh day of therapy, and at the first and second month after the end of treatment. Patients with positive findings were followed with weekly sonographic examinations until the abnormality resolved. Results. Abnormal gallbladder sonograms were demonstrated in 27 children (17%); 16 of them (10%) had gallbladder lithiasis, 11 had gallbladder sludge (7%) (n = 4 on the third day, n = 23 on the seventh day), and 1 developed urolithiasis (0.6%). Five children (19%) were symptomatic. The abnormalities resolved after a mean of 16 days (range 10-30 days). Patients with pseudolithiasis were older and treated with higher drug doses than those with normal sonographic findings (P< 0.01 and P< 0.05, respectively). Conclusions. Biliary pseudolithiasis (and infrequently nephrolithiasis) usually occurs in children receiving high doses of ceftriaxone. It is generally asymptomatic. When this reversible complication becomes symptomatic, unnecessary cholecystectomy should be avoided. (C) 2006 Wiley Periodicals, Inc

    Engineering of extracellular vesicles for display of protein biotherapeutics

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    Extracellular vesicles (EVs) have recently emerged as a highly promising cell-free bio-therapeutics. While a range of engineering strategies have been developed to functionalize the EV surface, current approaches fail to address the limitations associated with endogenous surface display, pertaining to the heterogeneous display of commonly used EV-loading moieties among different EV subpopulations. Here we present a novel engineering platform to display multiple protein therapeutics simultaneously on the EV surface. As proof-of-concept, we screened multiple endogenous display strategies for decorating the EV surface with cytokine binding domains derived from tumor necrosis factor receptor 1 (TNFR1) and interleukin 6 signal transducer (IL6ST), which can act as decoys for the pro-inflammatory cytokines TNFα and IL6, respectively. Combining synthetic biology and systematic screening of loading moieties, resulted in a three-component system which increased the display and decoy activity of TNFR1 and IL6ST, respectively. Further, this system allowed for combinatorial functionalization of two different receptors on the same EV surface. These cytokine decoy EVs significantly ameliorated disease phenotypes in three different inflammatory mouse models for systemic inflammation, neuroinflammation, and intestinal inflammation. Importantly, significantly improved in vitro and in vivo efficacy of these engineered EVs was observed when compared directly to clinically approved biologics targeting the IL6 and TNFα pathways

    High-throughput measurement of the content and properties of nano-sized bioparticles with single-particle profiler

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    We introduce a method, single-particle profiler, that provides single-particle information on the content and biophysical properties of thousands of particles in the size range 5–200 nm. We use our single-particle profiler to measure the messenger RNA encapsulation efficiency of lipid nanoparticles, the viral binding efficiencies of different nanobodies, and the biophysical heterogeneity of liposomes, lipoproteins, exosomes and viruses

    Identification of storage conditions stabilizing extracellular vesicles preparations

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    Extracellular vesicles (EVs) play a key role in many physiological and pathophysiological processes and hold great potential for therapeutic and diagnostic use. Despite significant advances within the last decade, the key issue of EV storage stability remains unresolved and under investigated. Here, we aimed to identify storage conditions stabilizing EVs and comprehensively compared the impact of various storage buffer formulations at different temperatures on EVs derived from different cellular sources for up to 2 years. EV features including concentration, diameter, surface protein profile and nucleic acid contents were assessed by complementary methods, and engineered EVs containing fluorophores or functionalized surface proteins were utilized to compare cellular uptake and ligand binding. We show that storing EVs in PBS over time leads to drastically reduced recovery particularly for pure EV samples at all temperatures tested, starting already within days. We further report that using PBS as diluent was found to result in severely reduced EV recovery rates already within minutes. Several of the tested new buffer conditions largely prevented the observed effects, the lead candidate being PBS supplemented with human albumin and trehalose (PBS‐HAT). We report that PBS‐HAT buffer facilitates clearly improved short‐term and long‐term EV preservation for samples stored at ‐80°C, stability throughout several freeze‐thaw cycles, and drastically improved EV recovery when using a diluent for EV samples for downstream applications
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