These findings clearly suggest the involvement of proinflammatory agents and ODFR in the pathogenesis of gastric lesions. The gastroprotective effects of SIM are mediated by inhibition of neutrophils activity, reduction of oxidative stress, and maintenance of vascular integrity. This study was conducted in rats; its relevance to human gastric ulcers is not known and warrants further study.

No abstract

Rheumatoid arthritis (RA) is a chronic systemic inflammatory disorder of unknown etiology that affects the synovial membrane of multiple joints. The clinical presentation of RA may vary from mild to severe with excessive erosions of periarticular bone leading to the loss of functional capacity. Both genetic and environmental factors are important in the development of this disorder. The genetic contribution to susceptibility for RA is underlined by a three-to four-fold higher concordance percentage for clinically expressed disease in monozygotic twins compared to dizygotic twins. The severity and long term outcome of RA have also been related to various genetic factors. Tumor necrosis factor (TNF), a pro-inflammatory cytokine, is involved in the pathogenesis of a variety of autoimmune disorders, including RA. A large number of studies have been undertaken to determine the role of TNF-α promoter polymorphisms in the pathogenesis of RA. On the other hand few attempts have been made to identify the association between TNF-α (lymphotoxin-alfa) polymorphism and RA. In this narrative review of published literature, an attempt has been made to determine the association between TNF-α promoter polymorphisms at positions –308, –238, –489, –857, –863 and TNF-β at +252 with respect to susceptibility to and severity of RA, as well as response to drug therapy. In spite of intra-and inter-ethnic variations, analysis of data suggests a significant role of TNF-α/TNF-β polymorphisms in determining the susceptibility/severity of RA and responsiveness to anti-TNF drug therapy. The TNF gene polymorphisms may be an interesting target for novel strategies to prevent RA and/or in its early treatment. Further studies using larger samples are needed to pinpoint the regulatory polymorphisms or haplotypes and their effects on the development of certain manifestations in RA.

Earlier studies have implicated reactive oxygen species and transitional metals in the pathogenesis of gastric lesions. In this study, we have evaluated the effect of 2,3-dimercaptopropanol (DMP), a thiol compound and metal chelator, on chemically induced gastroduodenal ulcers in rats. Acid secretion studies were undertaken using pylorus-ligated rats pretreated with DMP (3-100 mg/kg, i.p.). The effect of orally administered DMP on cysteamine-induced duodenal ulcers and ethanol-induced gastric ulcers was also tested. The level of nonprotein sulfhydryls (NP-SH) and gastric wall mucus was measured in the glandular stomach of rats treated with ethanol. None of the dose of DMP affected the volume or acidity of gastric secretion. Low doses of DMP (3 and 10 mg/kg) significantly reduced cysteamine-induced duodenal ulcers, whereas the high doses (30 and 100 mg/kg) were ineffective in this model. All the doses of DMP significantly and dose dependently attenuated ethanol-induced gastric lesions. The adverse effects of ethanol on gastric wall mucus and NP-SH were significantly and dose dependently reversed by DMP. In conclusion, the protective effects of DMP appear to be independent of gastric acid secretion and may be associated with counteracting the oxidative stress by replenishing glutathione and reducing the pool of transition metals.

Rheumatoid arthritis (RA) is a chronic systemic inflammatory disorder of unknown etiology that affects the synovial membrane of multiple joints. The clinical presentation of RA may vary from mild to severe with excessive erosions of periarticular bone leading to the loss of functional capacity. Both genetic and environmental factors are important in the development of this disorder. The genetic contribution to susceptibility for RA is underlined by a three-to four-fold higher concordance percentage for clinically expressed disease in monozygotic twins compared to dizygotic twins. The severity and long term outcome of RA have also been related to various genetic factors. Tumor necrosis factor (TNF), a pro-inflammatory cytokine, is involved in the pathogenesis of a variety of autoimmune disorders, including RA. A large number of studies have been undertaken to determine the role of TNF-α promoter polymorphisms in the pathogenesis of RA. On the other hand few attempts have been made to identify the association between TNF-α (lymphotoxin-alfa) polymorphism and RA. In this narrative review of published literature, an attempt has been made to determine the association between TNF-α promoter polymorphisms at positions –308, –238, –489, –857, –863 and TNF-β at +252 with respect to susceptibility to and severity of RA, as well as response to drug therapy. In spite of intra-and inter-ethnic variations, analysis of data suggests a significant role of TNF-α/TNF-β polymorphisms in determining the susceptibility/severity of RA and responsiveness to anti-TNF drug therapy. The TNF gene polymorphisms may be an interesting target for novel strategies to prevent RA and/or in its early treatment. Further studies using larger samples are needed to pinpoint the regulatory polymorphisms or haplotypes and their effects on the development of certain manifestations in RA.