Search results for "Hemoglobin"
showing 10 items of 504 documents
Fluid resuscitation-related coagulation impairment in a porcine hemorrhagic shock model.
2020
Background Fast and effective treatment of hemorrhagic shock is one of the most important preclinical trauma care tasks e.g., in combat casualties in avoiding severe end-organ damage or death. In scenarios without immediate availability of blood products, alternate regimens of fluid resuscitation represent the only possibility of maintaining sufficient circulation and regaining adequate end-organ oxygen supply. However, the fluid choice alone may affect the extent of the bleeding by interfering with coagulation pathways. This study investigates the impact of hydroxyethyl starch (HES), gelatine-polysuccinate (GP) and balanced electrolyte solution (BES) as commonly used agents for fluid resu…
Protein diffusion through charged nanopores with different radii at low ionic strength
2014
[EN] The diffusion of two similar molecular weight proteins, bovine serum albumin (BSA) and bovine haemoglobin (BHb), through nanoporous charged membranes with a wide range of pore radii is studied at low ionic strength. The effects of the solution pH and the membrane pore diameter on the pore permeability allow quantifying the electrostatic interaction between the chargedpore and the protein. Because of the large screening Debye length, both surface and bulk diffusion occur simultaneously. By increasing the pore diameter, the permeability tends to the bulk self-diffusion coefficient for each protein. By decreasing the pore diameter, the charges on the pore surface electrostatically hinder …
Application of High Energy Shock Waves to Single Cells
1989
Extracorporeal shock wave lithotripsy has been in clinical use since 1980 with several hundred thousand patients treated to date. Striking complications, like perirenal hematomas, are rare with a range of approximately 0.5%–1.5%. High dose applications in pigs and dogs have shown devastating effects on renal parenchyma with intrarenal hemorrhage and later fibrosis (Muschter et al. 1987). However, very little is known about shock wave effects on single cells like cellular blood components. Chaussy and coworkers (Chaussy 1982; Eisenberger et al. 1977) could show an increase of free hemoglobin after exposing canine erythrocytes to shock waves. Russo and associates (1986) found a profound influ…
Molecular characterization of hemoglobin from the honeybee Apis mellifera
2005
Due to the prevailing importance of the tracheal system for insect respiration, hemoglobins had been considered rare exceptions in this arthropod subphylum. Here we report the identification, cloning and expression analysis of a true hemoglobin gene in the honeybee Apis mellifera (Hymenoptera). The deduced amino acid sequence covers 171 residues (19.5 kDa) and harbors all globin-typical features, including the proximal and the distal histidines. The protein has no signal peptide for transmembrane transport and was predicted to localize in the cytoplasm. The honeybee hemoglobin gene shows an ancient structure, with introns in positions B12.2 and G7.0, while most other insect globins have div…
Effect of T-R conformational change on sickle-cell hemoglobin interactions and aggregation
2004
We compare the role of a conformational switch and that of a point mutation in the thermodynamic stability of a protein solution and in the consequent propensity toward aggregation. We study sickle-cell hemoglobin (HbS), the beta6 Glu-Val point mutant of adult human hemoglobin (HbA), in its R (CO-liganded) conformation, and compare its aggregation properties to those of both HbS and HbA in their T (unliganded) conformation. Static and dynamic light scattering measurements performed for various hemoglobin concentrations showed critical divergences with mean field exponents as temperature was increased. This allowed determining spinodal data points T(S)(c) by extrapolation. These points were …
Paroxysmal nocturnal hemoglobinuria-like phenotype and thrombotic risk in several clinical disorders.
2021
Potential Application of Voltammetry of Microparticles for Dating Porcine Blood-based Binding Media used in Taiwanese Architectural Polychromies
2012
A method for dating Hemoglobine-containing archaeological samples using the voltammetry of microparticles is described. This is based on the record of the voltammetric response of such materials attached to paraffin-impregnated graphite electrodes in contact with aqueous acetate buffer. Signals attributable to the Fe(III)/Fe(II) iron couple and their catalytic enhancement in the presence of H(2)O(2) can be correlated, via first-order reaction kinetics, with the time of aging of the samples. The method has been applied to the study and dating of the polychromed architectural decoration of different parts of the architectural complex of the Longshan Temple in Lukang (18(th) century, Taiwan).
Quaternary structure dependence of kinetic hole burning and conformational substates interconversion in hemoglobin.
2003
Using a sol-gel encapsulation technique, we have prepared samples of CO saturated human adult hemoglobin locked in the R or T quaternary conformation. We report time-resolved spectra of these samples in the Soret region following flash photolysis, in the time interval ranging from 250 ns to 200 ms and in the temperature interval of 100-170 K. A suitable analysis of the measured difference spectra enables us to obtain the spectral contribution of deoxyHb and HbCO molecules as a function of time and/or of the fraction N(t) of deoxyHb molecules. In our experimental time window geminate CO rebinding to hemoglobin in the T quaternary conformation is about 2 orders of magnitude slower than to hem…
Impact of Various Thermal Doses on the Oxygenation and Blood Flow in Malignant Tumors Upon Localized Hyperthermia
1984
Hyperthermia exhibits various direct cytocidal effects (Dickson, 1977; Overgaard, 1977; Suit, 1977). During heat treatment in vivo, several indirect mechanisms enhance the direct cell-killing capacity of hyperthermia. Therefore, the effective use of hyperthermia can overcome some of the well-known problems involved in modern radiation therapy at least in some malignant tumors.