Increased mucosal inflammatory cytokines in children with Helicobacter pylori-associated gastritis

The concentrations of tumour necrosis factor-alpha (TNF-α), interleukin-6 (IL-6) and IL-1-β in tissue homogenates of gastric mucosal biopsy specimens, and in gastric juice samples from Helicobacter pylori-positive and -negative children, were determined. The study population comprised 30 children with recurrent abdominal pain attending upper gastrointestinal endoscopy. Of these patients 18 were infected with H. pylori. Cytokine concentrations in gastric biopsy homogenate supernatants and in gastric juice were measured by enzyme-linked immunosorbent assay (ELISA). TNF-α levels in gastric juice and in gastric biopsy homogenate supernatants in patients with H. pylori-positive gastritis were found to be significantly higher than those in children without H. pylori infection. IL-6 levels were also higher in H. pylori -infected subjects, but the difference in IL-6 concentrations measured in gastric juice and biopsy homogenate supernatants did not reach statistical significance. IL-1-β concentrations in both specimens showed no significant difference between the two groups of children. It was suggested that increased levels of inflammatory cytokines, especially TNF-α and IL-6 generated locally within the gastric mucosa might be implicated in the pathogenesis of H. pylori-associated gastritis in childhood.     

A conus peptide blocks nicotinic receptors of unmyelinated axons in human nerves

The novel alpha-conotoxin Vc1.1 is a potential analgesic for the treatment of painful neuropathic conditions. In the present study, the effects of Vc1.1 were tested on the nicotine-induced increase in excitability of unmyelinated C-fiber axons in isolated segments of peripheral human nerves. Vc1.1 in concentrations above 0.1 microM antagonized the increase in axonal excitability produced by nicotine; the maximal inhibition was observed with 10 microM. We also demonstrate immunoreactivity for alpha 3 and alpha 5 subunits of neuronal nicotinic receptors on unmyelinated peripheral human axons. Blockade of nicotinic receptors on unmyelinated peripheral nerve fibers may be helpful in painful neuropathies affecting unmyelinated sympathetic and/or sensory axons.