Tear fluid concentration of mmp-8 is elevated in non-allergic eosinophilic conjunctivitis and correlates with conjunctival inflammatory cell infiltration.

BACKGROUND: To investigate tear fluid concentration of matrix metalloproteinase 8 (MMP-8) and its relation to conjunctival inflammatory cell infiltration in persistent non-allergic eosinophilic conjunctivitis (NAEC). METHODS: Two groups were included: 26 consecutive adult patients with NAEC (conjunctival eosinophils at least 1+ [1-10 eosinophils/slide], skin prick test [SPT] to common allergens negative), and 26 asymptomatic adult persons (no conjunctival eosinophils, SPT negative). MMP-8 tear fluid concentrations were determined by immunofluorometric assay, and conjunctival brush cytology samples from NAEC patients were used for MMP-8 immunocytochemistry. Gelatin zymography was used to illustrate proteolytic activity within the tear fluid samples. RESULTS: The mean MMP-8 concentration was significantly higher among NAEC patients (214.3 +/- 327.7 microg/l) than among healthy persons (50.4 +/- 62.3 microg/l, P < 0.0001). In the NAEC patients, tear fluid MMP-8 correlated with the numbers of conjunctival neutrophils (r = 0.66, P = 0.0002) as well as with goblet cells and columnar epithelial cells (r = 0.54 for both, P = 0.045), but not with the lymphocyte numbers (r = -0.36, P = 0.0741). By immunocytology, MMP-8 protein could also be detected in vivo in the inflammatory cell population within the conjunctiva. Zymography revealed that proteolysis was significantly higher in the NAEC group, and activated enzymes were practically found only in the NAEC group. CONCLUSIONS: The results showed that NAEC is an inflammatory condition characterized by increased tear fluid MMP-8 levels, probably derived from both inflammatory and structural conjunctival cells. The increased proteolytic activity in NAEC patients may indicate risk of conjunctival structural changes (remodeling).

Elevated expression and activation of matrix metalloproteinase 8 in tear fluid in atopic blepharoconjunctivitis.

PURPOSE: Matrix metalloproteinase 8 (MMP-8) is an effective collagenolytic enzyme that is associated with many ocular inflammatory diseases, such as uveitis, keratitis, and ocular rosacea. We studied the tear fluid concentration and activation of MMP-8 in atopic blepharoconjunctivitis (ABC) and the presence of the enzyme in conjunctival inflammatory cells in vivo. METHODS: Tear fluid samples were collected from 26 patients with ABC and 26 healthy controls. MMP-8 concentrations were determined by immunofluorometric assay, and its molecular forms and degrees of activation were studied by Western blotting. Conjunctival brush cytology samples from patients with ABC were used for MMP-8 immunocytochemistry. RESULTS: : The mean MMP-8 concentration was statistically significantly higher among the patients with ABC (545.6 +/- 879.3 microg/L) than among the healthy controls (50.4 +/- 62.3 microg/L, P = 0.0001). There was a statistically significant correlation between neutrophils detected in brush cytology and tear fluid MMP-8 (P = 0.032, r = 0.47). Both the control and ABC tear fluid samples contained predominantly the larger (60-80 kDa), highly glycosylated polymorphonuclear leukocyte-type MMP-8 isoform, as identified by Western blotting, but neither was found to contain the mesenchymal-type isoform. The active enzyme was in practice present only in the ABC samples. Immunostainings show the MMP-8 protein to be present in all the main inflammatory cell types within the conjunctiva. CONCLUSIONS: : A higher mean concentration and activation of MMP-8 is present in tear fluid in ABC. This finding probably reflects persistent inflammatory and collagenolytic activity associated with the disease.

Tear fluid levels of MMP-8 are elevated in ocular rosacea--treatment effect of oral doxycycline.

BACKGROUND: Ocular rosacea (OcR) is a chronic inflammatory disease especially affecting lid margins. Previous studies have shown that it is accompanied by increased levels and activation of tear fluid gelatinases. Matrix metalloproteinase 8 (MMP-8; collagenase 2) levels and activation are commonly elevated in many inflammatory conditions. Therefore we studied here whether MMP-8 concentration and activation in tear fluid are increased also in OcR, and if an oral doxycycline regimen could rectify the situation. METHODS: Tear fluid samples were collected from 22 OcR patients and 22 healthy controls. The OcR patients were then treated with an oral doxycycline regimen for 8 weeks and tear fluid samples collected again after 4 and 8 weeks. Conjunctival brush cytology and patients' subjective symptoms were scored. MMP-8 concentrations in the tear fluid were assessed by immunofluorometric assay and the molecular forms and isoenzyme expression of MMP-8 were studied by Western immunoblotting. RESULTS: The mean MMP-8 concentration was statistically significantly higher in OcR (156.8+/-207.4 mug/ml) than in the normal subjects (53.5+/-66.7 mug/ml) (P=0.036), but decreased to 79.2+/-141.6 mug/l and 53.6+/-75.2 mug/l after 4 and 8 weeks doxycycline treatment, respectively. There was a statistically significant difference between the untreated OcR and the MMP-8 results after 4 or 8 weeks of oral doxycycline (P=0.041 and 0.069, respectively) and the OcR patients experienced statistically significant relief of their subjective symptoms (P=0.0001) after the doxycycline regimen. Both the normal and OcR tear fluid contained the larger, 60-80 kDa highly- glycosylated polymorphonuclear leukocyte-type MMP-8 isoform in Western immunoblotting, but not the 45-55 kDa less glycosylated mesenchymal-type isoform. MMP-8 activation was in practice present only in the OcR samples, and was inhibited by oral doxycycline. CONCLUSIONS: MMP-8 concentration and activation degree in tear fluid are increased in OcR, probably reflecting increased inflammatory activity. Doxycycline effectively reduces these pathologically excessive levels and activation of MMP-8, and relieves patients' subjective symptoms.

Caffeine as a performance-enhancing drug in rats: sex, dose, housing, and task considerations.

Past animal studies of the performance-enhancing properties of stimulant drugs, such as caffeine, may have suffered from a number of procedural and ethical problems. For example. the housing condition of the animals was often not taken into consideration. As well, endurance tests, such as the forced swim task, sometimes involved ethically (and procedurally) questionable interference with natural swimming behaviour. Some of the manipulations, such as attaching a weight to the swimming animal's tail to increase the difficulty of the task and using mortality as a dependent variable, seem grotesque, even unnecessary. In this experiment, the performance-enhancing effects of caffeine in a modified forced swim task and a dominance task were evaluated using male and female rats as subjects (N=60), housed in either enriched or isolated environments. Analysis indicated that rats respond to caffeine as an interactive function of sex, housing, dose, and task characteristics. It was concluded that performance-enhancing properties of stimulant drugs may be the result of a complex interplay of variables, making simple generalizations questionable.