12 research outputs found
Glial Tumor Necrosis Factor Alpha (TNFα) Generates Metaplastic Inhibition of Spinal Learning
Injury-induced overexpression of tumor necrosis factor alpha (TNFα) in the spinal cord can induce chronic neuroinflammation and excitotoxicity that ultimately undermines functional recovery. Here we investigate how TNFα might also act to upset spinal function by modulating spinal plasticity. Using a model of instrumental learning in the injured spinal cord, we have previously shown that peripheral intermittent stimulation can produce a plastic change in spinal plasticity (metaplasticity), resulting in the prolonged inhibition of spinal learning. We hypothesized that spinal metaplasticity may be mediated by TNFα. We found that intermittent stimulation increased protein levels in the spinal cord. Using intrathecal pharmacological manipulations, we showed TNFα to be both necessary and sufficient for the long-term inhibition of a spinal instrumental learning task. These effects were found to be dependent on glial production of TNFα and involved downstream alterations in calcium-permeable AMPA receptors. These findings suggest a crucial role for glial TNFα in undermining spinal learning, and demonstrate the therapeutic potential of inhibiting TNFα activity to rescue and restore adaptive spinal plasticity to the injured spinal cord. TNFα modulation represents a novel therapeutic target for improving rehabilitation after spinal cord injury
The role of flavor and fragrance chemicals in TRPA1 (transient receptor potential cation channel, member A1) activity associated with allergies
TRPA1 has been proposed to be associated with diverse sensory allergic reactions, including thermal (cold) nociception, hearing and allergic inflammatory conditions. Some naturally occurring compounds are known to activate TRPA1 by forming a Michael addition product with a cysteine residue of TRPA1 through covalent protein modification and, in consequence, to cause allergic reactions. The anti-allergic property of TRPA1 agonists may be due to the activation and subsequent desensitization of TRPA1 expressed in sensory neurons. In this review, naturally occurring TRPA1 antagonists, such as camphor, 1,8-cineole, menthol, borneol, fenchyl alcohol and 2-methylisoborneol, and TRPA1 agonists, including thymol, carvacrol, 1’S-1’- acetoxychavicol acetate, cinnamaldehyde, α-n-hexyl cinnamic aldehyde and thymoquinone as well as isothiocyanates and sulfides are discussed
Identification of an immunodominant IgE epitope of the Parietaria judaica major allergen
Par j 1.0101 is one of the two major allergens of the Parietaria judaica (Pj) pollen, and its three-dimensional structure was built
by three-dimensional structural homology modeling. The resultant model was used to identify putative IgE binding regions.
Western blot analysis of gene fragmentation products showed that the 1 to 30 region was capable of binding specific IgE from a
pool of sera (n 5 30) of patients allergic to Pj pollen. Using the structural model as a guide, deletion and site-directed mutagenesis
of the 1 to 30 region was performed, and the amino acids involved in IgE binding were identified. In addition, a synthetic peptide
covering the 1 to 30 region was capable of binding human IgE without triggering histamine release from basophils of Pj allergic
patients (n 5 6) and thus represents a haptenic molecule with potential use as an immunotolerant agent. This epitope is also
present on the Par j 2.0101 major allergen representing a common IgE epitope. It is an immunodominant epitope, since it was
capable of inhibiting 30% of all specific IgE against the Pj major allergens, and therefore, it might be a candidate for the future
development of immunotherapeutics
Role and clinical importance of Helicobacter pylori infection in hemodialysis patients
Dyspepsia is an extrarenal symptom frequently found in hemodialysed patients; it is due to chronic renal failure, and uremic gastritis is a specific associated condition in chronic renal failure (CRF). On the other hand, in the general population, Helicobacter pylori infection is an important dyspepsia-related risk factor; its close connections with gastro-duodenal pathology are already known, above all the peptic disease in a really exclusive way. By observation of a dyalitic group of patients, opportunely matched with a no CRF group, we evaluated CRF-associated uremia and Helicobacter pylori infection which could eventually interact causing symptoms and lesions. A statistical analysis of obtained data allowed us to conclude that, although there is not, from an epidemiological view-point, a larger diffusion of Helicobacter pylori among dyalitic patients compared to general population, moreover the infection is uremia-synergic in causing gastro-duodenal symptoms and lesions. These findings, therefore, suggest systematically investigation a possible Helicobacter pylori infection in CRF patients and its relation to gastritis grading, and searching for probable active peptic lesions
Mesoporous silicas as versatile supports to tune the palladium-catalyzed selective aerobic oxidation of allylic alcohols
Surfactant templating offers a simple route to synthesize high-surface area silicas with ordered, tunable mesopore architectures. The use of these materials as versatile catalyst supports for palladium nanoparticles has been explored in the aerobic selective oxidation (selox) of allylic alcohols under mild conditions. Families of Pd/mesoporous silicas, synthesized through incipient wetness impregnation of SBA-15, SBA-16, and KIT-6, have been characterized by using nitrogen porosimetry, CO chemisorption, diffuse reflection infrared Fourier transform spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy, X-ray absorption spectroscopy, and high-resolution TEM and benchmarked in liquid phase allylic alcohol selox against a Pd/amorphous SiO standard. The transition from amorphous to two-dimensional parallel and three-dimensional interpenetrating porous silica networks conferred significant selox rate enhancements associated with higher surface densities of active palladium oxide sites. Dissolved oxygen was essential for insitu stabilization of palladium oxide, and thus maintenance of high activity on-stream, whereas selectivity to the desired aldehyde selox product over competing hydrogenolysis pathways was directed by using palladium metal