Inhibitory Activity of Angiotensin 1-Converting Enzyme of Phosphopeptides Obtained from Proteolytic Hydrolyzates of Oyster, Crassostrea gigas

In the previous papers^(1.2), we investigated the effects of ACE inhibitory activities of phosphopeptides of P-1 and C-2 which were obtained from edible oyster by proteolytic hydrolyzation. In this investigation, the ACE inhibitory phosphopeptides of T-1 was further purified by ultrafiltration and Sephadex G-15 column chromatography. ACE inhibitory activity was fractionated into three major phosphopeptides fractions of T-1-1,T-1-2 and T-1-3 in the pepsin hydrolyzates of the T-1 by gel filtration rechromatography on Sephadex G-15. The inhibition of ACE of the three kinds of phosphopeptides fractions (T-1-1,T-1-2 and T-1-3) was analyzed in vitro. The IC_ values of T-1-1,T-1-2 and T-1-3 of phosphopeptides for ACE were 0.159,0.095 and 0.140 mg protein/ml, respectively. The T-1-2 fraction had the most potent inyhibitory activity and showed 0.095 mg protein/ml inhibition against ACE at IC_ value. It has been demonstrated that the T-1-1,T-1-2 and T-1-3 contained about 33.3%, 3.01% and 27.12% as phosphonate-phosphorus of total phosphorus. The amino acid compositions of the phosphopeptides fractions (T-1-1,T-1-2 and T-1-3) were characterized by relatively high percentage for Tyr, Ser, Arg, Ala, Asp and Phe. When the ACE inhibitory phosphopeptides were analyzed by thin layer chromatography, some ninhydrine-positive spots were observed. These results suggest that the phosphopeptides are a mixture of several phosphopeptides

Increase of nitrosative stress in patients with eosinophilic pneumonia

<p>Abstract</p> <p>Background</p> <p>Exhaled nitric oxide (NO) production is increased in asthma and reflects the degree of airway inflammation. The alveolar NO concentration (Calv) in interstitial pneumonia is reported to be increased. However, it remains unknown whether NO production is increased and nitrosative stress occurs in eosinophilic pneumonia (EP). We hypothesized that nitrosative stress markers including Calv, inducible type of NO synthase (iNOS), and 3-nitrotyrosine (3-NT), are upregulated in EP.</p> <p>Methods</p> <p>Exhaled NO including fractional exhaled NO (FE_NO) and Calv was measured in ten healthy subjects, 13 patients with idiopathic pulmonary fibrosis (IPF), and 13 patients with EP. iNOS expression and 3-NT formation were assessed by immunocytochemistory in BALf cells. The exhaled NO, lung function, and systemic inflammatory markers of the EP patients were investigated after corticosteroid treatment for 4 weeks.</p> <p>Results</p> <p>The Calv levels in the EP group (14.4 ± 2.0 ppb) were significantly higher than those in the healthy subjects (5.1 ± 0.6 ppb, p < 0.01) and the IPF groups (6.3 ± 0.6 ppb, p < 0.01) as well as the FE_NOand the corrected Calv levels (all p < 0.01). More iNOS and 3-NT positive cells were observed in the EP group compared to the healthy subject and IPF patient. The Calv levels had significant positive correlations with both iNOS (r = 0.858, p < 0.05) and 3-NT positive cells (r = 0.924, p < 0.01). Corticosteroid treatment significantly reduced both the FE_NO(p < 0.05) and the Calv levels (p < 0.01). The magnitude of reduction in the Calv levels had a significant positive correlation with the peripheral blood eosinophil counts (r = 0.802, p < 0.05).</p> <p>Conclusions</p> <p>These results suggested that excessive nitrosative stress occurred in EP and that Calv could be a marker of the disease activity.</p

Polymères électrostrictifs à forte déformation : méthode d'élaboration et modélisation

La thèse porte de manière générale sur les polymères électrostrictifs qui peuvent être utilisés soit comme actionneurs électromécaniques souples, soit comme capteurs ou récupérateurs d’énergie. Le premier chapitre est une introduction générale aux systèmes couplés électromécaniques. Le choix des matériaux est exposé et porte sur les élastomères diélectriques et les polyuréthanes (PU) chargés par des nanoparticules conductrices de noir de carbone (CB). Le second chapitre porte sur la réalisation des films. Des particules de CB sous forme de micelles préformées et une technique « solution-cast » sont employées dans cette optique. Ce procédé permet une bonne dispersion des charges. Une amélioration de la déformation d’un facteur 1,6 est obtenue par introduction de particules de CB à 0.89 vol%. Le troisième chapitre présente la modélisation de phénomènes comme la saturation de la polarisation qui implique directement une saturation de la déformation. En modélisant la polarisation comme une fonction non-linéaire dépendant de deux variables (la permittivité bas niveau et un champ de saturation), on décrit ainsi correctement plusieurs phénomènes qui ne peuvent être interprétés par une approche linéaire et homogène. Les simulations effectuées montrent une bonne corrélation avec les expérimentations menées. Le quatrième chapitre propose une comparaison entre les films PU purs et chargés. Cette analyse porte non seulement sur des mesures mécaniques et électriques mais également en XRD ou en DSC afin de détecter le niveau de cristallisation. Une dispersion importante a ainsi été observée visuellement. Des déformations de l’ordre de 50 % ont ainsi été obtenues. Le cinquième chapitre porte sur l’effet lié à l’injection de charges électriques par bombardement électronique (HEBI), sur la déformation électrostrictive. Une telle approche permet ainsi un gain d’un facteur de l’ordre de 2 sur la déformation et semble réduire les pertes de façon très conséquente.In a general manner, the present thesis focuses on electrostrictive polymers which can be used either as flexible electromechanical actuators or as sensors or energy harvesters. Chapter 1 is a general introduction to electro-mechanical coupled systems. The choice of the materials is described and focuses on dielectric elastomers, polyurethane (PU) with conductive carbon black (CB) nano-particle fillers. Chapter 2 focuses on the film synthesis. CB nano-particles in the form of micelles and solution cast method were employed to provide good filler dispersion. The strain enhancement of a factor of 1.6 was obtained by 0.89 vol% CB doping. Chapter 3 exposes the modeling of electrostrictive actuation and in particular the saturation of the polarization. By modeling the polarization as a nonlinear function depending on two variables (low-level permittivity and saturation field), it is therefore possible to describe several phenomena that cannot be explained by a classical linear and homogeneous approach. Simulations performed using such an approach show a good agreement with experimental results. Chapter 4 presents the comparison between pure PU and composite films. It includes mechanical/electrical characterization as well as XRD or DSC measurements to detect the crystallization level. High dispersion level was visually confirmed. Strains of the order of 50 % were reached. Chapter 5 deals with the effect of electric charge injection by homogeneous electron beam irradiation (HEBI) on the electrostrictive strain. This technique therefore permits a gain of 2 on the obtained strain and seems to significantly reduce the losses in the material as well

High strain electrostrictive polymers : elaboration methods and modelization

In a general manner, the present thesis focuses on electrostrictive polymers which can be used either as flexible electromechanical actuators or as sensors or energy harvesters. Chapter 1 is a general introduction to electro-mechanical coupled systems. The choice of the materials is described and focuses on dielectric elastomers, polyurethane (PU) with conductive carbon black (CB) nano-particle fillers. Chapter 2 focuses on the film synthesis. CB nano-particles in the form of micelles and solution cast method were employed to provide good filler dispersion. The strain enhancement of a factor of 1.6 was obtained by 0.89 vol% CB doping. Chapter 3 exposes the modeling of electrostrictive actuation and in particular the saturation of the polarization. By modeling the polarization as a nonlinear function depending on two variables (low-level permittivity and saturation field), it is therefore possible to describe several phenomena that cannot be explained by a classical linear and homogeneous approach. Simulations performed using such an approach show a good agreement with experimental results. Chapter 4 presents the comparison between pure PU and composite films. It includes mechanical/electrical characterization as well as XRD or DSC measurements to detect the crystallization level. High dispersion level was visually confirmed. Strains of the order of 50 % were reached. Chapter 5 deals with the effect of electric charge injection by homogeneous electron beam irradiation (HEBI) on the electrostrictive strain. This technique therefore permits a gain of 2 on the obtained strain and seems to significantly reduce the losses in the material as well.La thèse porte de manière générale sur les polymères électrostrictifs qui peuvent être utilisés soit comme actionneurs électromécaniques souples, soit comme capteurs ou récupérateurs d’énergie. Le premier chapitre est une introduction générale aux systèmes couplés électromécaniques. Le choix des matériaux est exposé et porte sur les élastomères diélectriques et les polyuréthanes (PU) chargés par des nanoparticules conductrices de noir de carbone (CB). Le second chapitre porte sur la réalisation des films. Des particules de CB sous forme de micelles préformées et une technique « solution-cast » sont employées dans cette optique. Ce procédé permet une bonne dispersion des charges. Une amélioration de la déformation d’un facteur 1,6 est obtenue par introduction de particules de CB à 0.89 vol%. Le troisième chapitre présente la modélisation de phénomènes comme la saturation de la polarisation qui implique directement une saturation de la déformation. En modélisant la polarisation comme une fonction non-linéaire dépendant de deux variables (la permittivité bas niveau et un champ de saturation), on décrit ainsi correctement plusieurs phénomènes qui ne peuvent être interprétés par une approche linéaire et homogène. Les simulations effectuées montrent une bonne corrélation avec les expérimentations menées. Le quatrième chapitre propose une comparaison entre les films PU purs et chargés. Cette analyse porte non seulement sur des mesures mécaniques et électriques mais également en XRD ou en DSC afin de détecter le niveau de cristallisation. Une dispersion importante a ainsi été observée visuellement. Des déformations de l’ordre de 50 % ont ainsi été obtenues. Le cinquième chapitre porte sur l’effet lié à l’injection de charges électriques par bombardement électronique (HEBI), sur la déformation électrostrictive. Une telle approche permet ainsi un gain d’un facteur de l’ordre de 2 sur la déformation et semble réduire les pertes de façon très conséquente

Inhibitory Activity of Angiotensin 1-Converting Enzyme of Phosphopeptides Obtained from Proteolytic Hydrolyzates of Oyster, Crassostrea gigas

In the previous papers^(1.2), we investigated the effects of ACE inhibitory activities of phosphopeptides of P-1 and C-2 which were obtained from edible oyster by proteolytic hydrolyzation. In this investigation, the ACE inhibitory phosphopeptides of T-1 was further purified by ultrafiltration and Sephadex G-15 column chromatography. ACE inhibitory activity was fractionated into three major phosphopeptides fractions of T-1-1,T-1-2 and T-1-3 in the pepsin hydrolyzates of the T-1 by gel filtration rechromatography on Sephadex G-15. The inhibition of ACE of the three kinds of phosphopeptides fractions (T-1-1,T-1-2 and T-1-3) was analyzed in vitro. The IC_ values of T-1-1,T-1-2 and T-1-3 of phosphopeptides for ACE were 0.159,0.095 and 0.140 mg protein/ml, respectively. The T-1-2 fraction had the most potent inyhibitory activity and showed 0.095 mg protein/ml inhibition against ACE at IC_ value. It has been demonstrated that the T-1-1,T-1-2 and T-1-3 contained about 33.3%, 3.01% and 27.12% as phosphonate-phosphorus of total phosphorus. The amino acid compositions of the phosphopeptides fractions (T-1-1,T-1-2 and T-1-3) were characterized by relatively high percentage for Tyr, Ser, Arg, Ala, Asp and Phe. When the ACE inhibitory phosphopeptides were analyzed by thin layer chromatography, some ninhydrine-positive spots were observed. These results suggest that the phosphopeptides are a mixture of several phosphopeptides