Search results for "Complement"
showing 10 items of 2113 documents
Phenolic Substances from Phagnalon rupestre Protect against 2,4,6-Trinitrochlorobenzene-Induced Contact Hypersensitivity
2011
2-isoprenylhydroquinone-1-glucoside (1), 3,5-dicaffeoylquinic acid (2), and 3,5-dicaffeoylquinic acid methyl ester (3), isolated from Phagnalon rupestre, improved the contact hypersensitivity response to 2,4,6-trinitrochlorobenzene in mice. These phenolics reduced ear swelling and IL-1β content by 50% 24 h after challenge; in addition, 2 inhibited tumor necrosis factor-α by 53%. All three compounds also reduced interleukin-2 content by 50% 72 h after challenge. Both 2 and 3 inhibited metalloproteinase-9 levels in the skin lesions by 66% and 41%, respectively, and lowered cyclooxygenase-2 expression by 44% and 49%, respectively, at 24 h. Moreover, 2 was effective against atopic dermatitis in…
Inhibition of NF-κB Activation and iNOS Induction by ent-Kaurane Diterpenoids in LPS-Stimulated RAW264.7 Murine Macrophages
2009
Xerophilusin A (1), xerophilusin B (2), longikaurin B (3), and xerophilusin F (4) from Isodon xerophylus inhibit LPS-induced NO production in RAW 264.7 macrophages, with IC(50) values of 0.60, 0.23, 0.44, and 0.67 muM, respectively, and they all inhibited mRNA production in these same cells. They decreased the luciferase activity in RAW 264.7 cells transiently transfected with the NF-kappaB-dependent luciferase reporter, with IC(50) values of 1.8, 0.7, 1.2, and 1.6 muM, respectively. Compounds 1-3 reduced NF-kappaB activation, with compound 4 showing no effect, but p65 translocation from the cytoplasm to the nucleus and the LPS-induced degradation of IkappaB were inhibited by all four test …
Stimulation of monokine production by lipoteichoic acids
1991
Lipoteichoic acids (LTAs) isolated from bacterial species, including Staphylococcus aureus, Streptococcus pyogenes A, Enterococcus faecalis, Streptococcus pneumoniae, and Listeria monocytogenes, were tested for their ability to stimulate the production of interleukin-1 beta (IL-1 beta), IL-6, and tumor necrosis factor alpha in cultured human monocytes. LTAs from S. aureus and S. pneumoniae failed to induce monokine production when applied in the concentration range of 0.05 to 5.0 micrograms/ml. However, LTAs from several enterococcal species (0.5 to 5 micrograms/ml) induced the release of all three monokines at levels similar to those observed after lipopolysaccharide stimulation. The kinet…
Vibrio vulnificus biotype 2 serovar E gne but not galE is essential for lipopolysaccharide biosynthesis and virulence
2008
ABSTRACT This work aimed to establish the role of gne (encoding UDP-GalNAc 4-epimerase activity) and galE (encoding UDP-Gal-4-epimerase activity) in the biosynthesis of surface polysaccharides, as well as in the virulence for eels and humans of the zoonotic serovar of Vibrio vulnificus biotype 2, serovar E. DNA sequence data revealed that gne and galE are quite homologous within this species (≥90% homology). Mutation in gne of strain CECT4999 increased the surface hydrophobicity, produced deep alterations in the outer membrane architecture, and resulted in noticeable increases in the sensitivity to microcidal peptides (MP), to eel and human sera, and to phagocytosis/opsonophagocytosis. Furt…
Budlein A from Viguiera robusta inhibits leukocyte-endothelial cell interactions, adhesion molecule expression and inflammatory mediators release
2009
Budlein A has been reported to exert some analgesic and anti-inflammatory properties. In this study, we have evaluated its effect on LPS-induced leukocyte recruitment in vivo and the mechanisms involved in its anti-inflammatory activity. In vivo, intravital videomicroscopy was used to determine the effects of budlein A on LPS-induced leukocyte-endothelial cell interactions in the murine cremasteric microcirculation. In vitro, the effects of budlein A on LPS-induced cytokine, chemokine and nitrites release, T-cell proliferative response as well as cell adhesion molecule expression (CAM) were evaluated. In vivo, intraperitoneal administration of budlein A (2.6 mM/kg) caused a significant redu…
LPS challenge regulates gene expression and tissue localization of a Ciona intestinalis gene through an alternative polyadenylation mechanism.
2013
A subtractive hybridization strategy for the identification of differentially expressed genes was performed between LPS-challenged and naive Ciona intestinalis. This strategy allowed the characterization of two transcripts (Ci8short and Ci8long) generated by the use of two Alternative Polyadenylation sites. The Ci8long transcript contains a protein domain with relevant homology to several components of the Receptor Transporting Protein (RTP) family not present in the Ci8short mRNA. By means of Real Time PCR and Northern Blot, the Ci8short and Ci8long transcripts showed a different pattern of gene expression with the Ci8short mRNA being strongly activated after LPS injection in the pharynx. …
Inhibition of leukocyte functions by the alkaloid isaindigotone from Isatis indigotica and some new synthetic derivatives.
2001
The alkaloid isaindigotone (1a) and seven derivatives have been synthesized to study their influence on several leukocyte functions and the generation of inflammatory mediators. Isaindigotone (1a) was found to be a scavenger of superoxide generated either by the hypoxanthine/xanthine oxidase system or stimulated human neutrophils. Isaindigotone (1a) and its acetylated derivative (1b) also inhibited 5-lipoxygenase activity and leukotriene B(4) production in these cells, whereas none of the compounds affected degranulation. In RAW 264.7 macrophages stimulated with lipopolysaccharide, synthetic derivatives exerted higher inhibitory effects on prostaglandin E(2) (PGE(2)) and nitric oxide (NO) g…
CiC3-1a-Mediated Chemotaxis in the Deuterostome Invertebrate Ciona intestinalis (Urochordata)
2003
Abstract Deuterostome invertebrates possess complement genes, and in limited instances complement-mediated functions have been reported in these organisms. However, the organization of the complement pathway(s), as well as the functions exerted by the cloned gene products, are largely unknown. To address the issue of the presence of an inflammatory pathway in ascidians, we expressed in Escherichia coli the fragment of Ciona intestinalis C3-1 corresponding to mammalian complement C3a (rCiC3-1a) and assessed its chemotactic activity on C. intestinalis hemocytes. We found that the migration of C. intestinalis hemocytes toward rCiC3-1a was dose dependent, peaking at 500 nM, and was specific for…
The lipopolysaccharide O side chain of Vibrio vulnificus serogroup E is a virulence determinant for eels
1997
Vibrio vulnificus is a gram-negative bacterium capable of producing septicemic infections in eels and immunocompromised humans. Two biotypes are classically recognized, with the virulence for eels being specific to strains belonging to biotype 2, which constitutes a homogeneous lipopolysaccharide (LPS)-based O serogroup (which we have designated serogroup E). In the present study we demonstrated that the O side chain of this LPS determines the selective virulence of biotype 2 for eels: (i) biotype 1 strains (which do not belong to serogroup E) are destroyed by the bactericidal action of nonimmune eel serum (NIS) through activation of the alternative pathway of complement, (ii) biotype 2 str…
IG VII 53, an epigraphic rara avis in the corpus of greek metrical inscriptions
2017
Este artigo tem como objetivo estudar a inscrição publicada no IG VII 53 de uma perspectiva liguística. Ele consiste de uma seção em prosa que inclui um epigrama dedicado aos Mégaros caídos em combate nas guerras Pérsicas. A inscrição foi supostamente composta no século V a. C., mas o texto preservado não foi inscrito antes do IV século a. C. Após reavaliar a bibliografia principal sobre o texto, que estudou a inscrição principalmente do ponto de vista arqueológico, histórico ou literário, nós aplicamos uma análise linguística em dois níveis, baseada: a) na comparação dos dados linguísticos com a prosa epigráfica ou outras influências literárias, e b) nas restrições métricas que poderiam de…