Search results for " Shock"

Quaternary structures of GroEL and naïve-Hsp60 chaperonins in solution: a combined SAXS-MD study

2015

The quaternary structures of bacterial GroEL and human naïve-Hsp60 chaperonins in physiological conditions have been investigated by an innovative approach based on a combination of synchrotron Small Angle X-ray Scattering (SAXS) in-solution experiments and molecular dynamics (MD) simulations. Low-resolution SAXS experiments over large and highly symmetric oligomers are analyzed on the basis of the high-resolution structure of the asymmetric protein monomers, provided by MD. The results reveal remarkable differences between the solution and the crystallographic structure of GroEL and between the solution structures of GroEL and of its human homologue Hsp60.

Milrinone is preferred to levosimendan for mesenteric perfusion in hypoxia-reoxygenated newborn piglets treated with dopamine

2012

INTRODUCTION There is little information regarding the comparative hemodynamic effects of adding milrinone or levosimendan to dopamine infusion in hypoxia-reoxygenated (H-R) newborns. RESULTS Severely hypoxic piglets had cardiogenic shock with depressed cardiac index (CI) and mean arterial pressure (MAP). The hemodynamics deteriorated gradually after initial recovery upon reoxygenation. Heart rate and CI improved with milrinone (D+M) and levosimendan (D+L) administration (P < 0.05 vs. control). Both regimens improved carotid arterial flow and carotid vascular resistance; D+M additionally improved superior mesentric arterial flow (all P < 0.05 vs. control). No effect was found on renal arter…

Variations in physiological responses to thermal stress in congeneric limpets in the Mediterranean Sea

2014

Cardiac activity (Arrhenius breakpoint temperatures and Q10 relationships) and heat shock response (hsp70 expression) were measured in the congeneric limpets Patella rustica, P. caerulea and P. ulyssiponensis in order to test the relationship between their vertical distribution and physiological thermal tolerance. These species exhibit different vertical distributions along Mediterranean shores and despite the narrow tidal range in the Mediterranean, they experience different environmental conditions and consequently had specific thermal windows. Cardiac activity of the upper zoned P. rustica was maintained at higher temperatures than its mid- or low shore counterparts, P. caerulea and P. u…

PspA adopts an ESCRT-III-like fold and remodels bacterial membranes

2020

SummaryPspA is the main effector of the phage shock protein (Psp) system and preserves the bacterial inner membrane integrity and function. Here, we present the 3.6 Å resolution cryo-EM structure of PspA assembled in helical rods. PspA monomers adopt a canonical ESCRT-III fold in an extended open conformation. PspA rods are capable of enclosing lipids and generate positive membrane curvature. Using cryo-EM we visualized how PspA remodels membrane vesicles into μm-sized structures and how it mediates the formation of internalized vesicular structures. Hot spots of these activities are zones derived from PspA assemblies, serving as lipid transfer platforms and linking previously separated lip…

Isolation and characterization of a Paracentrotus lividus cDNA encoding a stress-inducible chaperonin

2001

Chaperonins are ubiquitous proteins that facilitate protein folding in an adenosine triphosphate–dependent manner. Here we report the isolation of a sea urchin cDNA (Plhsp60) coding for mitochondrial chaperonin (Cpn60), whose basal expression is further enhanced by heat shock. The described cDNA corresponds to a full-length mRNA encoding a protein of 582 amino acids, the first 32 of which constitute a putative mitochondrial targeting leader sequence. Comparative analysis has demonstrated that this protein is highly conserved in evolution.

Dust Production and Particle Acceleration in Supernova 1987A Revealed with ALMA

2013

Supernova (SN) explosions are crucial engines driving the evolution of galaxies by shock heating gas, increasing the metallicity, creating dust, and accelerating energetic particles. In 2012 we used the Atacama Large Millimeter/Submillimeter Array to observe SN 1987A, one of the best-observed supernovae since the invention of the telescope. We present spatially resolved images at 450um, 870um, 1.4mm, and 2.8mm, an important transition wavelength range. Longer wavelength emission is dominated by synchrotron radiation from shock-accelerated particles, shorter wavelengths by emission from the largest mass of dust measured in a supernova remnant (&gt;0.2Msun). For the first time we show unambig…

Fatal necrotising fasciitis associated with intramuscular injection of nonsteroidal anti-inflammatory drugs after uncomplicated endoscopic polypectom…

2007

Summary Necrotising fasciitis is a life-threatening infection of the superficial muscle fascia and the adjacent deep layer of subcutaneous tissue that is often fatal. A 46-year-old woman was admitted to the intensive care unit (ICU) three days after an uncomplicated endoscopic polypectomy because of necrotising fasciitis of left tight, buttock and retroperitoneal space and septic shock. Six hours after the polypectomy she was given an intramuscular injection of ketorolac in the left tight because of moderate low abdominal pain. Twelve and 24h later she was treated with another two intramuscular injection of diclofenac in the left tight for severe pains in the left hip joint region. The shoc…

Ceftazidime-avibactam use for klebsiella pneumoniae carbapenemase-producing k. pneumoniae infections: A retrospective observational multicenter study

2021

Abstract Background A growing body of observational evidence supports the value of ceftazidime-avibactam (CAZ-AVI) in managing infections caused by carbapenem-resistant Enterobacteriaceae. Methods We retrospectively analyzed observational data on use and outcomes of CAZ-AVI therapy for infections caused by Klebsiella pneumoniae carbapenemase–producing K. pneumoniae (KPC-Kp) strains. Multivariate regression analysis was used to identify variables independently associated with 30-day mortality. Results were adjusted for propensity score for receipt of CAZ-AVI combination regimens versus CAZ-AVI monotherapy. Results The cohort comprised 577 adults with bloodstream infections (n = 391) or nonba…

Proteinaceous bacterial toxins and pathogenesis of sepsis syndrome and septic shock: the unknown connection

1994

Major histocompatibility complex class II binding site for streptococcal pyrogenic (erythrogenic) toxin A.

1994

Streptococcal pyrogenic exotoxin A (SPEA) is an important pathogenicity factor of group A streptococci. It is a member of the family of „superantigens” produced by Staphylococcus aureus and Streptococcus pyogenes and its T lymphocyte stimulating activity is involved into the pathogenesis of certain diseases caused by pyogenic streptococci. In this study we have produced and characterized recombinant SPEA molecules in Escherichia coli. These molecules are indistinguishable from natural SPEA in both T cell stimulatory and HLA class II binding activities. Human class II molecules are more efficient than mouse class II molecules in presenting SPEA to T cells. In binding tests to major histocomp…