Expression of inducible nitric oxide synthase in a mouse model of anaphylaxis.

BACKGROUND: The generation of large quantities of nitric oxide (NO) is implicated in the pathogenesis of anaphylactic shock. The source of NO, however, has not been established and conflicting results have been obtained when investigators have tried to inhibit its production in anaphylaxis. OBJECTIVE: The aim of this study was to analyze the expression of inducible nitric oxide synthase (iNOS) and endothelial nitric oxide synthase (eNOS) in a mouse model of anaphylaxis. METHODS: BALB/c mice were sensitized and challenged with ovalbumin to induce anaphylaxis. Tissues were removed from the heart and lungs, and blood was drawn at different time points during the first 48 hours after induction of anaphylaxis. The Griess assay was used to measure nitric oxide generation. Nitric oxide synthase expression was examined by reverse transcriptase polymerase chain reaction and immunohistochemistry. RESULTS: A significant increase in iNOS mRNA expression and nitric oxide production was evident as early as 10 to 30 minutes after allergen challenge in both heart and lungs. In contrast, expression of eNOS mRNA was not altered during the course of the experiment. CONCLUSION: Our results support involvement of iNOS in the immediate physiological response of anaphylaxis.

Oral vitamins C and E as additional treatment in patients with acute anterior uveitis: a randomised double masked study in 145 patients.

AIM: To investigate the effect of additional oral vitamins C and E on acute anterior uveitis. METHODS: A placebo controlled double masked study on the effect of vitamin C 500 mg in combination with vitamin E 100 mg twice daily in 145 patients with acute anterior uveitis. As a primary end point variable, laser cell/flare measurements were performed. Best corrected and stenopeic visual acuity (VA) testing and clinical variable scores were measured. RESULTS: Laser flare measurements (ph/s) before treatment were 207.1 (SD 258) in the vitamin group and 143.6 (156) in the placebo group. After 3 days corresponding values were 80.2 (129) and 54.7 (82), after 7 days 89.2 (187) (12.5) and 85.8 (208), after 14 days 47.1 (109.5) and 40.5 (116) after 28 days 23.1 (53.6) and 23.1 (48), and after 56 days 15.6 (26) and 15.3 (17). There was no significant difference in time trend between the two treatment groups (RMANOVA; p = 0.53). Baseline VA (logMAR) was 0.106 (0.241) in the vitamin group and 0.128 (0.456) in the placebo group. VA after 3 days was 0. 236 (0.293) and 0.344 ( 0.489), after 7 days 0.204 (0.292) and 0.292 (0.479), after 14 days 0.162 (0.274) and 0.193 (0.454), after 28 days 0.096 (0.232) and 0.158 (0.436), and 0.026 (0.213) and 0.106 (0. 437) after 56 days. Although no significant difference in time trend was detected, evaluation of the VA data of the last time point (56 days) by means of the Mann-Whitney test showed a significantly better VA in the vitamin group (p = 0.01). CONCLUSIONS: There was no significant effect of vitamins C and E on laser flare measurements. The significant effect of the oral vitamins on visual acuity at 8 weeks after start of the oral vitamins C and E may indicate a protective effect in patients with acute anterior uveitis.

Diagnosis of carotid artery stenosis: comparison of 2DFT time-of-flight MR angiography with contrast angiography in 50 patients.

Fifty patients underwent 2DFT time-of-flight MR angiography and intraarterial contrast angiography for evaluation of possible carotid atherosclerotic disease. The MR angiography technique employed contiguous axial flow-sensitive (short TR/TE) slices that were reformatted and postprocessed by using a maximum-intensity projection algorithm to provide 16 angiographic views of the carotid arteries. Both studies were independently reviewed by two observers in a blinded manner. Carotid arteries were categorized as normal, mildly stenotic, moderately stenotic, severely stenotic, or occluded. For the 94 carotid arteries available for review, one observer reported a 70% agreement between the two techniques and the second observer reported a 56% agreement (p = .0001). The best correlation was in the severely stenotic category and the worst was in the occluded category. Agreement between observers was 67% for MR angiography and 72% for contrast angiography, which was similar to that between the two techniques. Although not all carotid atherosclerotic disease was visualized equally well, 2DFT time-of-flight MR angiography had a good overall correlation with the "gold standard" of intraarterial contrast angiography, supporting its use as a screening technique. While further improvements are needed, use of MR angiography as the primary diagnostic tool for many patients with suspected carotid stenosis should continue to increase.