[Free radicals in inner ear immune responses; immunohistochemical study of myeloperoxidase]

Soluble epoxide hydrolase gene deficiency or inhibition attenuates chronic active inflammatory bowel disease in IL-10(-/-) mice

BACKGROUND

Soluble epoxide hydrolase (sEH) metabolizes anti-inflammatory epoxyeicosatrienoic acids (EETs) into their much less active dihydroxy derivatives dihydroxyeicosatrienoic acids. Thus, targeting sEH would be important for inflammation.

AIMS

To determine whether knockout or inhibition of sEH would attenuate the development of inflammatory bowel disease (IBD) in a mouse model of IBD in IL-10(-/-) mice.

METHODS

Either the small molecule sEH inhibitor trans/-4-[4-(3-adamantan-1-yl-ureido)-cyclohexyloxy]-benzoic acid (t-AUCB) or sEH knockout mice were used in combination with IL-10(-/-) mice. t-AUCB was administered to mice in drinking fluid. Extensive histopathologic, immunochemical, and biochemical analyses were performed to evaluate effect of sEH inhibition or deficiency on chronic active inflammation and related mechanism in the bowel.

RESULTS

Compared to IL-10 (-/-) mice, sEH inhibition or sEH deficiency in IL-10(-/-) mice resulted in significantly lower incidence of active ulcer formation and transmural inflammation, along with a significant decrease in myeloperoxidase-labeled neutrophil infiltration in the inflamed bowel. The levels of IFN-γ, TNF-α, and MCP-1, as well VCAM-1 and NF-kB/IKK-α signals were significantly decreased as compared to control animals. Moreover, an eicosanoid profile analysis revealed a significant increase in the ratio of EETs/DHET and EpOME/DiOME, and a slightly down-regulation of inflammatory mediators LTB(4) and 5-HETE.

CONCLUSION

These results indicate that sEH gene deficiency or inhibition reduces inflammatory activities in the IL-10 (-/-) mouse model of IBD, and that sEH inhibitor could be a highly potential in the treatment of IBD.

Myeloperoxydase activity in the pathogenesis of cholesteatoma

OBJECTIVE

The aim of this study was to determine the effect of myeloperoxydase (MPO) in bone destruction in patients of chronic otitis media (COM) with cholesteatoma by immtino-histochemical staining and to conclude the possible relationship between bone destruction in patients with cholesteatoma accompanied with COM and MPO activity.

METHODS

The study was conducted on a total number of 81 patients where 51 of the patients were enrolled in the "patient group" and 30 of the patients were enrolled in the "control group" whom were operated due to otitis media. MPO positivism was monitored when a cytoplasmic staining process was performed.

RESULTS

Meanwhile, a significant difference is present at a statistically advanced level between the MPO levels of groups (p = 0.001; p < 0.01). However, MPO activity is absent in patients included in the control group or it can be observed at a very slight level. A moderate level or intense level of activity can be observed in patients enrolled in the study group. Excluding the destruction at the dura, all findings related with the middle ear and the erosion of the mastoid cavity and MPO activity indicated a statistically significant difference (p < 0.05). According to the destruction at the wall of the dura bone, distribution of MPO activity did not display a statistically meaningful difference (p > 0.05).

CONCLUSION

In this study, we investigated the relationship between MPO level and bone destruction and found a significant level of correlation among the fore said. A new era may be opened in the treatment of cholesteatoma when preoperative MPO levels are determined and adequate information is obtained related with bone erosion.