Search results for "SEP"

Proteolytic Enzymes Clustered in Specialized Plasma-Membrane Domains Drive Endothelial Cells’ Migration

2016

In vitro cultured endothelial cells forming a continuous monolayer establish stable cell-cell contacts and acquire a "resting" phenotype; on the other hand, when growing in sparse conditions these cells acquire a migratory phenotype and invade the empty area of the culture. Culturing cells in different conditions, we compared expression and clustering of proteolytic enzymes in cells having migratory versus stationary behavior. In order to observe resting and migrating cells in the same microscopic field, a continuous cell monolayer was wounded. Increased expression of proteolytic enzymes was evident in cell membranes of migrating cells especially at sprouting sites and in shed membrane vesi…

MARTX Toxin in the Zoonotic Serovar of Vibrio vulnificus Triggers an Early Cytokine Storm in Mice

2017

Vibrio vulnificus biotype 2-serovar E is a zoonotic clonal complex that can cause death by sepsis in humans and fish. Unlike other biotypes, Bt2 produces a unique type of MARTXVv (Multifunctional-Autoprocessive-Repeats-in-Toxin; RtxA13), which is encoded by a gene duplicated in the pVvBt2 plasmid and chromosome II. In this work, we analyzed the activity of this toxin and its role in human sepsis by performing in vitro, ex vivo, and in vivo assays. First, we demonstrated that the ACD domain, present exclusively in this toxin variant, effectively has an actin-cross-linking activity. Second, we determined that the whole toxin caused death of human endotheliocytes and monocytes by lysis and apo…

Cholera Toxin Subunit B for Sensitive and Rapid Determination of Exosomes by Gel Filtration.

2020

We developed a sensitive fluorescence-based assay for determination of exosome concentration. In our assay, Cholera toxin subunit B (CTB) conjugated to a fluorescence probe and a gel filtration technique (size-exclusion chromatography) are used. Exosomal membranes are particularly enriched in raft-forming lipids (cholesterol, sphingolipids, and saturated phospholipids) and in GM1 ganglioside. CTB binds specifically and with high affinity to exosomal GM1 ganglioside residing in rafts only, and it has long been the probe of choice for membrane rafts. The CTB-gel filtration assay allows for detection of as little as 3 × 108 isolated exosomes/mL in a standard fluorometer, which has a sensitivit…

Should we administer antifungal drugs before the diagnosis of invasive fungal infection in non-neutropenic critically ill patients?

2016

The Management of Staphylococcal Toxic Shock Syndrome. A Case Report

2016

Abstract Staphylococcal toxic shock syndrome (TSS) is most frequently produced by TSS toxin-1 (TSST-1) and Staphylococcal enterotoxin B (SEB), and only rarely by enterotoxins A, C, D, E, and H. Various clinical pictures can occur depending on severity, patient age and immune status of the host. Severe forms, complicated by sepsis, are associated with a death rate of 50-60%. The case of a Caucasian female infant, aged seven weeks, hospitalized with a diffuse skin rash, characterized as allergodermia, who initially developed TSS with axillary intertrigo, is reported. TSS was confirmed according to 2011 CDC criteria, and blood cultures positive for Methicillin-sensitive Staphylococcus aureus (…

Aestivation motifs explain hypertension and muscle mass loss in mice with psoriatic skin barrier defect

2021

Aim Recent evidence suggests that arterial hypertension could be alternatively explained as a physiological adaptation response to water shortage, termed aestivation, which relies on complex multi-organ metabolic adjustments to prevent dehydration. Here, we tested the hypothesis that chronic water loss across diseased skin leads to similar adaptive water conservation responses as observed in experimental renal failure or high salt diet. Methods We studied mice with keratinocyte-specific overexpression of IL-17A which develop severe psoriasis-like skin disease. We measured transepidermal water loss and solute and water excretion in the urine. We quantified glomerular filtration rate (GFR) by…

Validation of the Sepsis MetaScore for Diagnosis of Neonatal Sepsis

2016

What’s known on this subject Neonates are at increased risk for developing sepsis, but this population often exhibits ambiguous clinical signs that complicate the diagnosis of infection. No biomarker has yet shown enough diagnostic accuracy to rule out sepsis at the time of clinical suspicion. What this study adds We show that a gene-expression-based signature is an accurate objective measure of the risk of sepsis in a neonate or preterm infant, and it substantially improves diagnostic accuracy over that of commonly used laboratory-based testing. Implementation might decrease inappropriate antibiotic use. Background Neonatal sepsis can have devastating consequences, but accurate diagnosis i…

2020

BACKGROUND: Detailed descriptions of the patterns of disease progression of deceased coronavirus disease 2019 (COVID-19) patients have not been well explored. OBJECTIVES: This study sought to explore disease progression patterns and risk factors associated with mortality of deceased patients with COVID-19. MATERIALS AND METHODS: Epidemiological, clinical, laboratory, and imaging data (from 15 January to 26 March 2020) of laboratory-confirmed COVID-19 patients were collected retrospectively from two hospitals, Hubei province, China. Disease progression patterns of patients were analyzed based on laboratory data, radiological findings, and Sequential Organ Failure Assessment (SOFA) score. Ris…

Ectodomain shedding of CD99 within highly conserved regions is mediated by the metalloprotease meprin β and promotes transendothelial cell migration.

2016

The adhesion molecule CD99 is essential for the transendothelial migration of leukocytes. In this study, we used biochemical and cellular assays to show that CD99 undergoes ectodomain shedding by the metalloprotease meprin β and subsequent intramembrane proteolysis by γ-secretase. The cleavage site in CD99 was identified by mass spectrometry within an acidic region highly conserved through different vertebrate species. This finding fits perfectly to the unique cleavage specificity of meprin β with a strong preference for aspartate residues and suggests coevolution of protease and substrate. We hypothesized that limited CD99 cleavage by meprin β would alter cellular transendothelial migratio…

Efficient and reproducible experimental infections of rats with Blastocystis spp.

2018

Although Blastocystis spp. infect probably more than 1 billion people worldwide, their clinical significance is still controversial and their pathophysiology remains poorly understood. In this study, we describe a protocol for an efficient and reproducible model of chronic infection in rats, laying the groundwork for future work to evaluate the pathogenic potential of this parasite. In our experimental conditions, we were unable to infect rats using vacuolar forms of an axenically cultivated ST4 isolate, but we successfully established chronic infections of 4 week-old rats after oral administration of both ST3 and ST4 purified cysts isolated from human stool samples. The infection protocol …