The localization of matrix metalloproteinases-8 and -13 in cholesteatoma, deep-meatal and post-auricular skin: a comparative analysis.

CONCLUSION: The presence of matrix metalloproteinase (MMP)-8 and MMP-13 was found to be significantly higher in cholesteatoma compared with post-auricular skin. The results show that the control group used has implications for further studies. OBJECTIVES: To compare the presence of MMP-8 and MMP-13 in cholesteatoma, deep meatal and post-auricular skin. Our null hypothesis was that there was no difference in expressions of MMP-8 and MMP-13 in the three groups. MATERIALS AND METHODS: The study was carried out in a secondary care specialist centre and used prospective retrieval of specimens for immunohistological localization of MMP-8 and MMP-13. Eleven patients undergoing cholesteatoma surgery were recruited for the study. Eleven cholesteatoma specimens, 10 deep meatal skin specimens and 10 post-auricular skin specimens were analysed. Specimens were analysed by immunohistochemistry using monoclonal antibodies to MMP-8 and MMP-13. Two observers scored the slides independently in a blind fashion. RESULTS: The presence of MMP-8 and MMP-13 was found to be significantly higher in cholesteatoma compared to post-auricular skin (p=0.02, p=0.03, respectively). There were no significant differences in expression of MMP-8 and MMP-13 between cholesteatoma and deep meatal skin (p=0.08, p=0.09, respectively). There were no significant differences in the control groups.

Topical anti-inflammatory activity of human recombinant epidermal growth factor.

The topical anti-inflammatory activity of epidermal growth factor (EGF) was evaluated in inflammation models induced by 12-Otetradecanoylphorbol-13-acetate, croton oil and arachidonic acid. When EGF (1.5, 3 or 6 microg/ear) was coapplied with each inflammatory agent, there was a dose-related decrease in inflammation as assessed by ear punch weights, myeloperoxidase activity as well as by histopathological studies. The precise anti-inflammatory action of EGF is yet unclear, but we believe that interference with arachidonic acid metabolism may play an important role.

Aldehyde dehydrogenase (ALDH) isozymes in the gray short-tailed opossum (Monodelphis domestica): tissue and subcellular distribution and biochemical genetics of ALDH3.

Polyacrylamide gel isoelectric focusing (PAGE-IEF), cellulose acetate electrophoresis, and histochemical techniques were used to examine the tissue and subcellular distribution, genetics and biochemical properties of aldehyde dehydrogenase (ALDH) isozymes in a didelphid marsupial, the gray short-tail opossum (Monodelphis domestica). At least 14 zones of activity were resolved by PAGE-IEF and divided into five isozyme groups and three ALDH classes, based upon comparisons with properties previously reported for human, baboon, rat, and mouse ALDHs. Opossum liver ALDHs were distributed among cytosol (ALDHs 1 and 5) and large granular (mitochondrial) fractions (ALDHs 2 and 5). Similarly, kidney ALDHs were distributed between the cytosol (ALDH5) and the mitochondrial fractions (ALDHs 2, 4, and 5), whereas a major isozyme (ALDH3), found in high activity in cornea, esophagus, ear pinna, tail, and stomach extracts, was localized predominantly in the cytosol fraction. Phenotypic variants of the latter enzyme were shown to be inherited in a normal Mendelian fashion, with two alleles at a single locus (ALDH3) showing codominant expression. The data provided evidence for genetic identity of corneal, ear pinna, tail, and stomach ALDH3 and supported biochemical evidence from other mammalian species that this enzyme has a dimeric subunit structure.