Staphylococcus aureus and group A Streptococcus pyogenes (GAS) express superantigen (SAg) exotoxin proteins capable of inducing lethal shock. To induce toxicity, SAgs must bind not only to the major histocompatibility complex II molecule of antigen-presenting cells and the variable β chain of the T-cell receptor but also to the dimer interface of the T-cell costimulatory receptor CD28. Here, we...

38, 6th ASM Conference on Streptococcal Genetics, Ashville, NC, USA]. GBS β-h/c contributes to virulence in animal studies. When administered to neonatal rats via the pulmonary route, NH GBS mutants possess a 1000-fold greater LD50 than the wild-type parent strains, confirming a role in the pathogenesis of pneumonia and systemic spread [52]. In an adult mouse model of GBS arthritis, hemolysin e...

INTRODUCTION Previous randomized trials failed to demonstrate a decrease in mortality of patients with acute lung injury treated by exogenous surfactant. The aim of this prospective randomized study was to evaluate the effects of exogenous porcine-derived surfactant on pulmonary reaeration and lung tissue in patients with acute lung injury and acute respiratory distress syndrome (ALI/ARDS). M...

Alveolar fibrin generation has been suggested to possess strong surfactant-inhibitory potency. In perfused rabbit lungs, fibrin formation in the alveolar space was induced by sequential ultrasonic aerosolization of fibrinogen and thrombin, and the efficacy of rescue administration of surfactant and urokinase was investigated. Ventilation-perfusion (VA/Q) distribution was assessed by the multipl...

OBJECTIVES We hypothesized that inhaled nitric oxide treatment of premature infants at risk for bronchopulmonary dysplasia would not adversely affect endogenous surfactant function or composition. METHODS As part of the Nitric Oxide Chronic Lung Disease Trial of inhaled nitric oxide, we examined surfactant in a subpopulation of enrolled infants. Tracheal aspirate fluid was collected at specif...

Core flooding experiments were conducted with the objective of evaluating near miscible surfactant alternating CO2 injection and the effect of surfactant concentrations on gas-oil and water displacements in porous media. The core samples were provided from a low permeability mixed wet oil reservoir at 156 °F and 1900 psia. In addition, very few studies of surfactant adsorption on car...

Repair of severe skin tissue injury remains a great challenge and wound infection is still formidable problem. In this study, new macroporous antibacterial gelatin/alginate (SAG)-based hydrogels for repair were designed developed based on in-situ gas foaming method ion release strategy as result Mg-Cu particles degradation in the hydrogel matrix. The addition decreased storage modulus SAG, main...

The aim of this paper is to provide a perspective on the effect of gas type on the permeability of foam films stabilized by different types of surfactant and to present a critical overview of the tracer gas experiments, which is the common approach to determine the trapped fraction of foam in porous media. In these experiments some part of the gas is replaced by a "tracer gas" during the steady...

OBJECTIVES Biologically variable ventilation improves lung function in acute respiratory distress models. If enhanced recruitment is responsible for these results, then biologically variable ventilation might promote distribution of exogenous surfactant to nonaerated areas. Our objectives were to confirm model predictions of enhanced recruitment with biologically variable ventilation using comp...

Using a hydrodynamic lattice-gas model, we study interface growth in a binary fluid with various concentrations of surfactant. We find that the interface is smoothed by small concentrations of surfactant, while microemulsion droplets form for large surfactant concentrations. To assist in determining the stability limits of the interface, we calculate the change in the roughness and growth expon...