Mcleanfrandsen7119
Extracellular vesicles (EVs) are membrane-derived lipid bilayers secreted by bacteria and eukaryotic cells. Bacterial membrane vesicles were discovered over 60 years ago and have been extensively studied in Gram-negative bacteria. During their production, EVs are loaded with proteins, nucleic acids, and various compounds that are subsequently released into the environment. TEN-010 purchase Depending on the packaged cargo, EVs have a broad spectrum of action and are involved in pathogenesis, antibiotic resistance, nutrient uptake, and nucleic acid transfer. Due to differences in cell wall structure, EVs in Gram-positive bacteria have been disregarded for decades, and our understanding of their biogenesis and host cell interaction is incomplete. Recently, studies on bacteria such as Staphylococcus aureus, Streptococcus spp., Bacillus subtilis, and Mycobacterium spp. have demonstrated EV production in Gram-positive bacteria and shown the great importance EVs have in Gram-positive bacterial physiology and disease progression. Here, we review the latest findings on the biogenesis and functions of EVs from Gram-positive bacteria and identify key areas for future research.Acinetobacter baumannii is an opportunistic and frequently multidrug-resistant Gram-negative bacterial pathogen that primarily infects critically ill individuals. Indirect transmission from patient to patient in hospitals can drive infections, supported by this organism's abilities to persist on dry surfaces and rapidly colonize susceptible individuals. To investigate how A. baumannii survives on surfaces, we cultured A. baumannii in liquid media for several days and then analyzed isolates that lost the ability to survive drying. One of these isolates carried a mutation that affected the gene encoding the carbon storage regulator CsrA. As we began to examine the role of CsrA in A. baumannii, we observed that the growth of ΔcsrA mutant strains was inhibited in the presence of amino acids. The ΔcsrA mutant strains had a reduced ability to survive drying and to form biofilms but an improved ability to tolerate increased osmolarity compared with the wild type. We also examined the importance of CsrA for A. baumannii virulence. The ΔcsrA mutant strains had a greatly reduced ability to kill Galleria mellonella larvae, could not replicate in G. mellonella hemolymph, and also had a growth defect in human serum. Together, these results show that CsrA is essential for the growth of A. baumannii on host-derived substrates and is involved in desiccation tolerance, implying that CsrA controls key functions involved in the transmission of A. baumannii in hospitals.
High-frequency optical coherence tomography (HF-OCT) is an intra-vascular imaging technique capable of assessing device-vessel interactions at spatial resolution approaching 10 µm. We tested the hypothesis that adequately deployed Woven EndoBridge (WEB) devices as visualized by HF-OCT lead to higher aneurysm occlusion rates.
In a leporine model, elastase-induced aneurysms (n=24) were treated with the WEB device. HF-OCT and digital subtraction angiography (DSA) were performed following WEB deployment and repeated at 4, 8, and 12 weeks. Protrusion (0-present, 1-absent) and malapposition (0-malapposed, 1-neck apposition >50%) were binary coded. A device was considered 'adequately deployed' by HF-OCT and DSA if apposed and non-protruding. Aneurysm healing on DSA was reported using the 4-point WEB occlusion score A or B grades were considered positive outcome. Neointimal coverage was quantified on HF-OCT images at 12 weeks and compared with scanning electron microscopy (SEM).
Adequate deployment on HF-OCT correlated with positive outcome (P=0.007), but no statistically significant relationship was found between good outcome and adequate deployment on DSA (P=0.289). Absence of protrusion on HF-OCT correlated with a positive outcome (P=0.006); however, malapposition alone had no significant relationship (P=0.19). HF-OCT showed a strong correlation with SEM for the assessment of areas of neointimal tissue (R²=0.96; P<0.001). More neointimal coverage of 78%±32% was found on 'adequate deployment' cases versus 31%±24% for the 'inadequate deployment' cases (P=0.001).
HF-OCT visualizes features that can determine adequate device deployment to prognosticate early aneurysm occlusion following WEB implantation and can be used to longitudinally monitor aneurysm healing progression.
HF-OCT visualizes features that can determine adequate device deployment to prognosticate early aneurysm occlusion following WEB implantation and can be used to longitudinally monitor aneurysm healing progression.
We aimed to compare the outcome of acute ischemic stroke (AIS) patients who received endovascular thrombectomy (EVT) with confirmed COVID-19 to those without.
We performed a retrospective analysis using the Vizient Clinical Data Base and included hospital discharges from April 1 to July 31 2020 with ICD-10 codes for AIS and EVT. The primary outcome was in-hospital death and the secondary outcome was favorable discharge, defined as discharge home or to acute rehabilitation. We compared patients with laboratory-confirmed COVID-19 to those without. As a sensitivity analysis, we compared COVID-19 AIS patients who did not undergo EVT to those who did, to balance potential adverse events inherent to COVID-19 infection.
We identified 3165 AIS patients who received EVT during April to July 2020, in which COVID-19 was confirmed in 104 (3.3%). Comorbid COVID-19 infection was associated with younger age, male sex, diabetes, black race, Hispanic ethnicity, intubation, acute coronary syndrome, acute renal failure, a. AIS EVT patients with COVID-19 were younger, more likely to be male, have systemic complications, and almost twice as likely to be black and over three times as likely to be Hispanic.
In AIS patients treated with EVT, comorbid COVID-19 infection was associated with in-hospital death and a lower odds of favorable discharge compared with patients without COVID-19, but not compared with AIS patients with COVID-19 who did not undergo EVT. AIS EVT patients with COVID-19 were younger, more likely to be male, have systemic complications, and almost twice as likely to be black and over three times as likely to be Hispanic.