Search results for "elastase"
showing 10 items of 88 documents
Nitric oxide metabolites, leukocyte activation markers and oxidative status in dialyzed subjects.
2008
<i>Aims:</i> Our purpose was to evaluate, in a group of 42 end-stage renal disease patients who regularly undergo hemodialysis, some indexes of leukocyte activation, nitric oxide metabolites (NOx) and other parameters that reflect the oxidative stress before and after a standard hemodialysis session. <i>Methods:</i> Elastase and myeloperoxidase (MPO) were determined by means of ELISA. The NO production was evaluated by a micromethod which measures the concentration of NOx. The oxidation of polyunsaturated fatty acids was evaluated in plasma by detection of thiobarbituric acid-reactive substances (TBARS). Total antioxidant status (TAS) was obtained using spectrophotom…
In vivo effects of intravascularly applied Escherichia coli hemolysin: dissociation between induction of granulocytopenia and lethality in monkeys.
1993
The effects of intravascular application of endotoxin-depleted Escherichia coli hemolysin (HlyA) was studied in rabbits and monkeys. In rabbits, bolus application of HlyA calculated to effect final blood levels of approximately 2-3 HU/ml (200-300 ng/ml) caused an acute fall of polymorphonuclear blood leukocytes to less than 20% of starting levels within 5 min. Additionally, platelet counts dropped to approximately 30% of starting levels, whereas lymphocyte counts varied considerably and seldom fell to less than 50%. Nine out ten animals that received 2-4 HU/ml toxin died within 90 min post application. These animals presented with signs of acute respiratory failure and post mortem inspectio…
Dexamethasone dipropionate loaded nanoparticles of α-elastin-g-PLGA for potential treatment of restenosis.
2013
A graft copolymer of α-elastin with poly(lactic-co-glycolic) acid (PLGA) has been synthesized and successfully employed to produce nanoparticles. Exploiting the known biological activity of α-elastin to promote the maintenance of smooth muscle cells (SMCs) contractile phenotype and the antiproliferative effect of glucocorticoids, the aim of this research was to produce drug-loaded nanoparticles suitable for potential treatment of restenosis. In particular, nanoparticles of α-elastin-g-PLGA with a mean size of 200 nm have been produced and loaded with dexamethasone dipropionate (10% w/w), chosen as a model drug that inhibits proliferation of vascular SMCs. These nanoparticles are able to pro…
Inhibition of human sPLA2 and 5-lipoxygenase activities by two neo-clerodane diterpenoids
1999
Abstract The inhibitory effect of two neo -clerodane diterpenoids, E -isolinaridial (EI) and its methylketone derivative (EIM), isolated from Linaria saxatilis var. glutinosa , on PLA2 and other enzyme activities involved in the inflammatory process was studied. Both compounds inhibited human synovial sPLA 2 in a concentration-dependent manner with IC 50 values of 0.20 and 0.49 μM, respectively, similar to scalaradial. Besides, these compounds decreased the cell-free 5-lipoxygenase activity and A23187-induced neutrophil LTB 4 biosynthesis. Another function of human neutrophils, such as receptor-mediated degranulation, was also significantly reduced. In contrast, none of the compounds affect…
Cycloamphilectenes, a new type of potent marine diterpenes: inhibition of nitric oxide production in murine macrophages.
2003
The inhibitory effect of a series of 6 cycloamphilectenes, novel marine diterpenes based on amphilectene skeletons and isolated from the Vanuatu sponge Axinella sp., on NO, PGE(2) and TNFalpha production in murine peritoneal macrophages was studied. These compounds reduced potently nitric oxide production in a concentration-dependent manner with IC(50) values in the submicromolar range (0.1-4.3 microM). Studies on intact cells and Western blot analysis showed that the more potent cycloamphilectenes reduced the expression of inducible nitric oxide synthase without affecting cyclo-oxygenase-2 expression. Among them cycloamphilectene 2, the unique compound bearing an exocyclic methylene group,…
Diterpenoids from Tetraclinis articulata that Inhibit Various Human Leukocyte Functions
2003
Ten new compounds, eight of them pimarane derivatives (1-8), together with a menthane dimer (9) and a totarane diterpenoid (10), were isolated from the leaves and wood of Tetraclinis articulata. The structures of 1-10 were established by using spectroscopic techniques, including 2D NMR spectra. Pimaranes 1-5 were found to possess an unusual cis interannular union of the B and C rings, which, from a biogenetic perspective, could be derived from the hydration of a carbocation at C-8. Compounds 4-6 and a mixture of 7 and 11 modulated different human leukocyte functions at a concentration of 10 microM, mainly the degranulation process measured as myeloperoxidase release and, to a lesser extent,…
Subendothelial infiltration of neutrophil granulocytes and liberation of matrix-destabilizing enzymes in an experimental model of human neo-intima.
2008
SummaryIt was the objective of this study to examine the role of human neutrophil granulocytes (PMN) in an in-vitro model of human neo-intima developed for the study of atherosclerosis. Human granulocytes were subjected to a co-culture model of human endothelial and smooth muscle cells. Subendothelial lipid accumulation was achieved by addition of native LDL to the culture medium. Tissue samples were analyzed by immunohistochemistry and scanning/transmission electron microscopy, and culture supernatants were examined for the presence of interleukin- 8 (IL-8), MCP-1, GRO-α, elastase and matrixmetalloproteinase-8 (MMP-8). Following addition of 2 mg/ml LDL, adherence, transmigration and infilt…
Determination of Human Granulocyte Elastase by the Immunoactivation Method on the Hitachi® 717 Automated Analyser
1991
This paper describes a fully mechanized homogeneous immunoassay using the immunoactivation method for the rapid and specific determination of human granulocyte elastase (EC 3.4.21.37) in plasma. The method uses anti-elastase antibody fragments from sheep, conjugated to horseradish peroxidase. These enzyme-antibody conjugates bind to the elastase-alpha 1-proteinase inhibitor complex present in plasma. A separate sample blank with non-specific sheep antibody fragments conjugated to horseradish peroxidase corrects for errors introduced by the sample matrix. Measurements were performed with the clinical chemistry analyser Hitachi 717. A single determination can be performed in 10 min, requiring…
Synthesis and biological properties of the seven alanine-modified analogues of the marine cyclopeptide hymenamide C
2002
The synthesis and biological activity of the marine cyclopeptide hymenamide C(1), showing an inhibitory effect on human neutrophil elastase degranulation release, were recently described. Based on this result, it was decided to undertake a systematic structure-activity relationship study of this cyclopeptide, based on the Ala-scan technique, in order to obtain useful information for the rational design of additional analogues. The synthesis and characterization of the seven Ala modified analogues are reported and their biological and pharmacological properties are described.
Secretion of haemolysins and proteases by Aeromonas hydrophila EO63: separation and characterization of the serine protease (caseinase) and the metal…
2004
C . E S T E V E A N D T . H . B I R K B E C K . 2004. Aims: To determine the haemolysins and proteases excreted by the virulent strain EO63 of Aeromonas hydrophila grown in complex media and to then fractionate and characterize them, in particular those with elastolytic activity. Methods and Results: The amount of haemolytic and proteolytic activity in EO63 culture supernatants was dependent on the culture media used. In all media, haemolysins appeared during the phase of active growth and haemolytic activity decreased quickly thereafter, as previously described for aerolysin. In contrast, proteases were mainly released during the stationary phase. Serine protease activity in EO63 culture s…