The stimulation of adenosine 2A receptor reduces inflammatory response in mouse articular chondrocytes treated with hyaluronan oligosaccharides

The adenosine 2A receptor (A_2AR) is greatly involved in inflammation pathologies such as rheumatoid arthritis. By interacting with A_2AR, the purine nucleoside adenosine acts as a potent endogenous inhibitor of the inflammatory process in a variety of tissues. Hyaluronan (HA) fragments act to prime inflammation via CD44 and the toll-like receptor 4 (TLR-4). The aim of this study was to investigate whether the inhibition/stimulation of A_2AR modulates the inflammation cascade primed by small HA fragments in mouse articular chondrocytes.6-mer HA treatment induced up-regulation of CD44, TLR4 and A_2AR mRNA expression and the related protein levels, and NF-kB activation, that in turn increased TNF-α, IL-1β, and IL-6 and production. Treatment with a selective ₂A adenosine receptor agonist (2-phenylaminoadenosine) enhanced A_2AR increase, as well as the inhibition of CD44 and TLR4 activity using two specific antibodies abolished up-regulation of CD44 and TLR4, and significantly reduced, especially by antibody inhibition, NF-kB activation and pro-inflammatory cytokine production. Furthermore, the exposure of chondrocytes to A_2AR specific interference mRNA (A_2AR siRNA) enhanced HA 6-mer induced NF-kB activation and inflammatory cytokine increase. Finally, the use of an exchange protein activated by cAMP (EPAC) siRNA and a specific PKA inhibitor showed a predominant EPAC involvement in the mediation of the anti-inflammatory activity exerted by A_2AR stimulation.These data suggest that HA depolymerization occurring during inflammation contributes to priming of the inflammatory cascade, while endogenous adenosine, by exerting anti-inflammatory response via A_2AR, could be a modulatory mechanism that attempts to attenuate the inflammation process.     

Chirality of azelastine and flezelastine: Investigation of their enantiomers

The racemic phthalazinone derivatives azelastine and flezelastine were resolved via formation of diastereomeric salts and fractional crystallization thereof. The optical purity of the enantiomers was checked by HPLC. Pharmacological investigations in vitro and in vivo related to antiallergic/antiasthmatic activity revealed some stereospecific differences. However, chiral discrimination could not be observed with regard to overall activity of azelastine and flezelastine. © 1993 Wiley-Liss, Inc.     

Two new cases of cutaneous alternariosis with a review of the literature

Summary Two cases of cutaneous phaeohyphomycosis due to Alternaria tenuissima in patients affected with primitive myeloproliferative syndrome and lymphocytic lymphoma respectively are reported.Following a review of the specific literature, the authors discuss the etiopathogenic mechanisms, the clinical and histologic aspects of the lesions and the therapeutic problems.     

NMR-based metabolomic study of type 1 diabetes

The genetic homogeneity of the people of Sardinia makes it an ideal place to study genetic related diseases such as type 1 diabetes, which in this island has one of the highest incidence worldwide. The principal objective of this study was to use ¹H high-resolution NMR spectroscopy and supervised methods of multivariate data analysis to highlight the importance of the variation of low concentration metabolites between healthy and diabetic Sardinian children. To achieve this goal, statistical analyses were performed after removal of the prevailing signals of sugars and citrate (related to carbohydrate metabolism) and of hippurate (a metabolite of bacterial origins) whose presence overwhelmed all the other compounds effects on classification. The variable influence in the statistical model showed that other metabolites deriving from gut microbial metabolism (p-cresol sulphate and phenylacetylglycine) were heavily involved in classification. This suggests the importance of changes in gut microbiota composition associated with type 1 diabetes in children.     

Intraerythrocytic administration of a synthetic Plasmodium antigen elicits antibody response in mice, without carrier molecules or adjuvants

The synthetic peptide (NANP)₂₀, reproducing the tandem-repeated epitope of the circumsporozoite protein of Plasmodium (Laverania) falciparum, was entrapped into murine, autologous erythrocytes by a hypotonic dialysis method. Mice immunized intravenously with minute amounts of encapsulated peptide produced considerable antibody titres. This result indicates that intraerythrocytic antigen administration may have a potential as an immunization system for humans, since it dispenses with adjuvants and carrier molecules.     

Profiling histidine dipeptides in plasma and urine after ingesting beef, chicken or chicken broth in humans

The in vitro metabolic stability of histidine-dipeptides (HD), carnosine (CAR) and anserine (ANS), in human serum, and their absorption kinetics after ingesting pure carnosine or HD rich foods in humans have been investigated. Healthy women (n = 4) went through four phases of taking one dose of either 450 mg of pure carnosine, 150 g beef (B), 150 g chicken (C), or chicken broth (CB) from 150 g chicken with a >2-week washout period between each phase. Blood samples were collected at 0, 30, 60, 100, 180, 240, and 300 min, and urine samples before and after (up to 7 h) ingesting pure carnosine or food. Both plasma and urine samples were analyzed for HD concentrations using a sensitive and selective LC–ESI-MS/MS method. CAR was undetectable in plasma after ingesting pure carnosine, B, C or CB. By contrast, plasma ANS concentration was significantly increased (P < 0.05) after ingesting C or CB, respectively. Urinary concentrations of both CAR and ANS were 13- to 14-fold increased after ingesting B, and 14.8- and 243-fold after CB ingestion, respectively. Thus, dietary HD, which are rapidly hydrolyzed by carnosinase in plasma, and excreted in urine, may act as reactive carbonyl species sequestering agents.