Neuroprotection by the endogenous cannabinoid anandamide and arvanil against in vivo excitotoxicity in the rat: role of vanilloid receptors and lipoxygenases.

Type 1 vanilloid receptors (VR1) have been identified recently in the brain, in which they serve as yet primarily undetermined purposes. The endocannabinoid anandamide (AEA) and some of its oxidative metabolites are ligands for VR1, and AEA has been shown to afford protection against ouabain-induced in vivo excitotoxicity, in a manner that is only in part dependent on the type 1 cannabinoid (CB1) receptor. In the present study, we assessed whether VR1 is involved in neuroprotection by AEA and by arvanil, a hydrolysis-stable AEA analog that is a ligand for both VR1 and CB1. Furthermore, we assessed the putative involvement of lipoxygenase metabolites of AEA in conveying neuroprotection. Using HPLC and gas chromatography/mass spectroscopy, we demonstrated that rat brain and blood cells converted AEA into 12-hydroxy-N-arachidoylethanolamine (12-HAEA) and 15-hydroxy-N-arachidonoylethanolamine (15-HAEA) and that this conversion was blocked by addition of the lipoxygenase inhibitor nordihydroguaiaretic acid. Using magnetic resonance imaging we show the following: (1) pretreatment with the reduced 12-lipoxygenase metabolite of AEA, 12-HAEA, attenuated cytotoxic edema formation in a CB1 receptor-independent manner in the acute phase after intracranial injection of the Na+/K+-ATPase inhibitor ouabain; (2) the reduced 15-lipoxygenase metabolite, 15-HAEA, enhanced the neuroprotective effect of AEA in the acute phase; (3) modulation of VR1, as tested using arvanil, the VR1 agonist capsaicin, and the antagonist capsazepine, leads to neuroprotective effects in this model, and arvanil is a potent neuroprotectant, acting at both CB1 and VR1; and (4) the in vivo neuroprotective effects of AEA are mediated by CB1 but not by lipoxygenase metabolites or VR1.

Immunodiagnostically applicable monoclonal antibodies to the circulating anodic antigen of Schistosoma mansoni bind to small, defined oligosaccharide epitopes.

Gut-associated glycoproteins constitute a major group of the circulating excretory antigens produced by human Schistosoma species. The O-glycans of the relatively abundant circulating anodic antigen (CAA) from S. mansoni carry long stretches of unique -->6(GlcA beta 1-->3)GalNAc beta 1--> repeats. Specific anti-carbohydrate monoclonal antibodies (mAbs) are essential tools for the immunodiagnostic detection of CAA in the serum or urine of Schistosoma-infected subjects. In order to define the epitopes recognised by these anti-CAA mAbs, we screened a series of protein-coupled synthetic di- to pentasaccharide building blocks of the CAA polysaccharide for immunoreactivity, using ELISA and surface plasmon resonance spectroscopy. It was shown that anti-CAA IgM mAbs preferentially recognise -->6(GlcA beta 1-->3)GalNAc beta 1--> disaccharide units. Interestingly, no mouse anti-CAA mAbs of the IgG class were found that bind to the synthetic epitopes, although many of the IgG mAbs tested do recognise native CAA in a carbohydrate-dependent manner. In addition, both IgM and IgG class antibodies could be detected in human infection sera using the synthetic CAA fragments. These synthetic schistosome glycan epitopes and their matching set of specific mAbs are useful tools that further the development of diagnostic methods and are helpful in defining the immunological responses of the mammalian hosts to schistosome glycoconjugates.

Dominant antibody responses to Fucalpha1-3GalNAc and Fucalpha1-2Fucalpha1-3GlcNAc containing carbohydrate epitopes in Pan troglodytes vaccinated and infected with Schistosoma mansoni.

The development of the humoral anti-glycan immune response of chimpanzees, either or not vaccinated with radiation-attenuated Schistosoma mansoni cercariae, was followed during 1 year after infection with S. mansoni. During the acute phase of infection both the vaccinated and the control chimpanzees produce high levels of immunoglobulin G (IgG) antibodies against carbohydrate structures that are characteristic for schistosomes carrying the Fucalpha1-3GalNAc and Fucalpha1-2Fucalpha1-3GlcNAc motifs, but not to the more widespread occurring structures GalNAcbeta1-4GlcNAc, GalNAcbeta1-4(Fucalpha1-3)GlcNAc, and Galbeta1-4(Fucalpha1-3)GlcNAc (Lewis(x)). In addition, high levels of IgM antibodies were found against the trimeric Lewis(x) epitope. Apparently, the schistosome-characteristic carbohydrate structures are dominant epitopes in the anti-glycan humoral immune response of the chimpanzees. All chimpanzees showed an increase in the level of antibodies against most of the carbohydrate structures tested directly after vaccination, peaking at challenge time and during the acute phase of infection. With the exception of anti-F-LDN antibody responses, the anti-carbohydrate antibody responses upon schistosome infection of the vaccinated animals were muted in comparison to the control animals.

The influence of plasticiser on molecular organisation in dry amylopectin measured by differential scanning calorimetry and solid state nuclear magnetic resonance spectroscopy.

The interaction of crystalline and amorphous amylopectin with the plasticisers glycerol and ethylene glycol in the absence of water was studied with differential scanning calorimetry (DSC) and solid state NMR. At room temperature glycerol interacts mainly with the amorphous regions, while for ethylene glycol the amylopectin crystallinity does not effect the interaction. After heating the mixtures, an additional immobilisation of the plasticiser occurs.