Search results for "Shock"

Effect of?-cyclodextrin complexation on the photohaemolitic activity induced by Ketoprofen and Naproxen sensitization

1993

Red blood cell lysis photosensitized by two non-steroidal anti-inflammatory drugs Naproxen (NAP) and Ketoprofen (KPF) was investigated in the presence of β-cyclodextrin (β-Cyd). The photohaemolysis was inhibited by the addition of β-Cyd both for NAP and, to a lesser extent, for KPF. The protective action was found only in a restricted range of concentration of β-Cyd. Higher amounts of β-Cyd interfered with the resistance of the cell to the osmotic shock induced by the photosensitization process. The complexing action of β-Cyd was ascertained through UV-vis absorption spectroscopy, induced circular dichroism and emission spectroscopy. The isolated complexes Naproxen-β-Cyd (NAP-β-Cyd) and Ket…

Comparative analysis of the coordinated motion of Hsp70s from different organelles observed by single-molecule three-color FRET.

2021

Cellular function depends on the correct folding of proteins inside the cell. Heat-shock proteins 70 (Hsp70s), being among the first molecular chaperones binding to nascently translated proteins, aid in protein folding and transport. They undergo large, coordinated intra- and interdomain structural rearrangements mediated by allosteric interactions. Here, we applied a three-color single-molecule Forster resonance energy transfer (FRET) combined with three-color photon distribution analysis to compare the conformational cycle of the Hsp70 chaperones DnaK, Ssc1, and BiP. By capturing three distances simultaneously, we can identify coordinated structural changes during the functional cycle. Be…

The effect of osmo-induced stress on product formation by Zymomonas mobilis on sucrose

2000

The intensification of biosynthesis of fructooligosaccharides in the presence of high salt concentrations was observed during sucrose (10%) fermentation by Zymomonas mobilis 113S. A 0.6 M NaCl concentration led to an increase of oligosaccharide productivity by 3.5-fold. Sorbitol formation was increased in the presence of 0.16 M NaCl and was inhibited at highest salt concentrations. In a medium with high (65%, w/w) sucrose content the salts gave inhibitory effects on fructooligosaccharide production by lyophilised Z. mobilis cells. Influence of salts on gluconic acid and sorbitol formation under these conditions was studied. The ratio of oligosaccharides and gluconic acid productivity (Qolig…

Immediate early response of the marine sponge Suberites domuncula to heat stress: Reduction of trehalose and glutathione concentrations and glutathio…

1997

The marine sponge Suberites domuncula was used to identify early markers for thermal stress. Cubes from sponges have been kept for 30 min at 31°C (10 °C higher than the ambient temperature). After this treatment the sponge cubes were kept again at 21°C. To demonstrate that the animals reacted to the elevated temperature, the expression of heat shock protein (HSP) was determined. Using an antibody raised against HSP70, it was found by Western blotting that the animals specifically express a 45 kDa polypeptide after heat treatment. It was shown that even after 10 min of heat treatment the steady-state concentration of trehalose drops by 40% from a base level of 13 nmol/mg protein. The activit…

Distinct amino acids of  the Oenococcus oeni small heat shock protein Lo18 are essential for damaged protein protection and membrane stabilization

2010

The small heat shock protein (smHsp) Lo18 from lactic acid bacteria Oenococcus oeni reduces in vitro thermal aggregation of proteins and modulates the membrane fluidity of native liposomes. An absence of information relating to the way in which the smHsp demonstrates a stabilizing effect for both proteins and membranes prompted this study. We expressed three Lo18 proteins with amino acid substitutions in Escherichia coli to investigate their ability to prevent E. coli protein aggregation and their capacity to stabilize E. coli whole-cell membranes. Our results showed that the alanine 123 to serine substitution induces a decrease in chaperone activity in denaturated proteins, and that the ty…

Hemorrhagic Shock and Antioxidants: Influence of Timing on Survival

2001

Interaction Between Osmotic and Hydrostatic Pressure in Yeast Inactivation

1999

The protective effect of an osmotic perturbation on high-pressure inactivation has been investigated using a yeast strain:Saccharomyces cerevisiae. Osmotic shocks have been carried out with binary medium (glycerol/sorbitol and water) with or without glucose. Variations of osmotic level, osmotic shift kinetics and time between osmotic and hydrostatic treatment (350 MPa/10 min) have allowed the characterization of cell baroprotection. Two different cumulative baroprotection effects have been distinguished: one conferred by the solute on biological structures and the other related to the osmotic stress, cell volume variations and stress metabolism response (HSP, trehalose). These experiments h…

Circular RNAs in Sepsis: Biogenesis, Function, and Clinical Significance

2020

Sepsis is a life-threatening condition that occurs when the body responds to an infection that damages it is own tissues. The major problem in sepsis is rapid, vital status deterioration in patients, which can progress to septic shock with multiple organ failure if not properly treated. As there are no specific treatments, early diagnosis is mandatory to reduce high mortality. Despite more than 170 different biomarkers being postulated, early sepsis diagnosis and prognosis remain a challenge for clinicians. Recent findings propose that circular RNAs (circRNAs) may play a prominent role in regulating the patients’ immune system against different pathogens, including bacteria and viruses. Mou…

Estudio de los marcadores de severidad en la sepsis grave y shock séptico

2014

La sepsis es la respuesta del organismo a la infección, y se caracteriza por la activación de distintos sistemas de proteasas, inflamación intravascular y una alteración en la extracción de oxígeno, que pueden conducir a un cuadro de disfunción multiorgánica. La complejidad de esta respuesta inmune del huésped hace poco probable que un solo biomarcador pueda describir adecuadamente y estratificar a los pacientes con sepsis. HIPÓTESIS La determinación de parámetros relacionados con la inflamación, coagulación, estrés oxidativo y perfusión tisular como pilares fundamentales de la fisiopatología de la sepsis, así como la interrelación de ellos, se considera de utilidad en la práctica clínica p…

A Model for Assessing the Magnitude and Distribution of Sheath Currents in Medium and High-Voltage Cable Lines

2020

In this article, the authors discuss a simulation model to study the effect of cross-bonding of metallic sheaths, and/or nonmagnetic armors, of single-core medium- and high-voltage cables in the same circuit. In single-core cables, the resistive losses due to the induced circulating currents in cable sheaths or armors cause an increase of the cable temperature, which therefore reduces its ampacity. This is a serious issue affecting the distribution and transmission lines. In addition, the risk of electric shock due to induced voltages may be present if a person is in contact with the armor/sheath at its unbounded end. For these reasons, special bonding techniques of metal sheaths are employ…