The last decade has seen a sharp increase in the number of scientific publications describing physiological and pathological functions of extracellular vesicles (EVs), a collective term covering various subtypes of cell-released, membranous structures, called exosomes, microvesicles, microparticles, ectosomes, oncosomes, apoptotic bodies, and many other names. However, specific issues arise when working with these entities, whose size and amount often make them difficult to obtain as relatively pure preparations, and to characterize properly. The International Society for Extracellular Vesicles (ISEV) proposed Minimal Information for Studies of Extracellular Vesicles (“MISEV”) guidelines for the field in 2014. We now update these “MISEV2014” guidelines based on evolution of the collective knowledge in the last four years. An important point to consider is that ascribing a specific function to EVs in general, or to subtypes of EVs, requires reporting of specific information beyond mere description of function in a crude, potentially contaminated, and heterogeneous preparation. For example, claims that exosomes are endowed with exquisite and specific activities remain difficult to support experimentally, given our still limited knowledge of their specific molecular machineries of biogenesis and release, as compared with other biophysically similar EVs. The MISEV2018 guidelines include tables and outlines of suggested protocols and steps to follow to document specific EV-associated functional activities. Finally, a checklist is provided with summaries of key points.
Background & Aims
The efficacy of treatment of Helicobacter pylori infection has decreased steadily due to increasing resistance to clarithromycin, metronidazole, and levofloxacin. Resistance to amoxicillin is generally low, and high intragastric pH increases the efficacy of amoxicillin, so we investigated whether a combination of a high-dose proton-pump inhibitor and amoxicillin (dual therapy) was more effective than standard first-line or rescue therapies in eradicating H pylori.
Methods
We performed a large-scale, multi-hospital trial to compare the efficacy of a high-dose dual therapy (HDDT) with that of standard therapies in treatment-naïve (n=450) or treatment-experienced (n=168) patients with H pylori infection. Treatment-naïve patients were randomly assigned to groups given HDDT (rabeprazole 20 mg and amoxicillin 750 mg, 4 times/day for 14 days; group A1), sequential therapy for 10 days (group B1), or clarithromycin-containing triple therapy for 7 days (group C1). Treatment-experienced patients were randomly assigned to groups given HDDT for 14 days (group A2), sequential therapy for 10 days (B2), or levofloxacin-containing triple therapy for 7 days (C2). H pylori infection was detected using the 13C–urea breath test. We evaluated factors associated with treatment outcomes.
Results
In the intention-to-treat treat analysis, H pylori was eradicated in 95.3% of patients in group A1 (95% confidence interval [CI], 91.9%–98.8%), 85.3% in B1 (95% CI, 79.6%–91.1%), and 80.7% in group C1 (95% CI, 74.3%–87.1%). Infection was eradicated in 89.3% of patients in group A2 (95% CI, 80.9%–97.6%), 51.8% in group B2 (95% CI, 38.3%–65.3%), and 78.6% (95% CI, 67.5%–89.7%). The efficacy of HDDT was significantly higher than that of currently recommended regimens, irrespective of CYP2C19 genotype. Bacterial resistance to drugs was associated with treatment failure. There were no significant differences between groups in adverse events or patient adherence.
Conclusions
HDDT is superior to standard regimens as empiric first-line or rescue therapy for H pylori infection, with similar safety profiles and tolerability. ClinicalTrials.gov no: NCT01163435.
Single- and few-layer MoS2 nanoflowers are first discovered to have a piezo-catalyst effect, exhibiting an ultra-high degradation activity in the dark by introducing external mechanical strains. The degradation ratio of the Rhodamine-B dye solution reaches 93% within 60 s under ultrasonic-wave assistance in the dark.
Fibrosis of the peritoneal cavity remains a serious, life-threatening problem in the treatment of kidney failure with peritoneal dialysis. The mechanism of fibrosis remains unclear partly because the fibrogenic cells have not been identified with certainty. Recent studies have proposed mesothelial cells to be an important source of myofibroblasts through the epithelial-mesenchymal transition; however, confirmatory studies in vivo are lacking. Here, we show by inducible genetic fate mapping that type I collagen-producing submesothelial fibroblasts are specific progenitors of a-smooth muscle actin-positive myofibroblasts that accumulate progressively in models of peritoneal fibrosis induced by sodium hypochlorite, hyperglycemic dialysis solutions, or TGF-b1. Similar genetic mapping of Wilms' tumor-1-positive mesothelial cells indicated that peritoneal membrane disruption is repaired and replaced by surviving mesothelial cells in peritoneal injury, and not by submesothelial fibroblasts. Although primary cultures of mesothelial cells or submesothelial fibroblasts each expressed a-smooth muscle actin under the influence of TGF-b1, only submesothelial fibroblasts expressed a-smooth muscle actin after induction of peritoneal fibrosis in mice. Furthermore, pharmacologic inhibition of the PDGF receptor, which is expressed by submesothelial fibroblasts but not mesothelial cells, attenuated the peritoneal fibrosis but not the remesothelialization induced by hypochlorite. Thus, our data identify distinctive fates for injured mesothelial cells and submesothelial fibroblasts during peritoneal injury and fibrosis.
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