Thus, P aeruginosa cultures also were incubated under the following control conditions: (1) in the presence of exhausted DETA-NO (0.5, 5, and 50 mM; generated by previously incubating DETA-NO in open polystyrene test tubes at 60°C for 24 h); and (2) NaNO2 (0.5, 5, and 50 mM). Following exposure to DETA-NO, exhausted DETA-NO, or NaNO2, the bacterial number was quantified in triplicate on 5% sheep’s blood agar plates.
All results are expressed as the mean ± SEM. Differences between groups were assessed by analysis of variance (ANOVA) [one-way ANOVA, Sigmastat; Jandel Scientific Corporation; San Rafael, CA). Changes in eNO levels over time following DETA-NO nebulization were analyzed by repeated-measures ANOVA. Post hoc comparisons were performed with a Student-Newman-Keuls t test where appropriate. Differences were accepted as statistically significant at p < 0.05 (two-tailed test).
Mouse Model of Acute P aeruginosa Pneumonia
Following the induction of pneumonia, mice appeared lethargic and tachypneic, and exhibited decreased grooming and exploratory behavior. The lungs of mice with pneumonia were grossly edematous and had patchy areas of hemorrhage. Survival at 24 h was not significantly different in pneumonia mice vs sham mice (p = 0.10) [Table 1]. The inhalation of NO or exposure to nebulized DETA-NO did not have any qualitative effects on the behavior either of sham or pneumonia mice, nor were there any gross pathologic pulmonary effects. Moreover, treatment with iNO or DETA-NO had no significant effect on survival in either pneumonia or sham mice (Table 1). birth control online
In untreated pneumonia mice, the total pulmonary bacterial load was 6.1 ± 1.8-fold greater than the instillate bacterial number, indicating intrapul-monary bacterial proliferation over the 24 h following intratracheal instillation (Fig 1). DETA-NO exposure (both 12.5 and 125 ^mol) was associated with a 65 ± 19% (p < 0.05) decrease in the total pulmonary bacterial load. There was no difference in the effect on bacterial load of the two doses of DETA-NO.
Figure 1. Effect of nebulized DETA-NO (12.5 or 125 ^mol) or iNO (10 or 40 ppm) on the pulmonary bacterial burden as a multiple of the number of organisms instilled in mice with P aeruginosa pneumonia (untreated pneumonia control [C] group, 28 mice; other treatment groups, 6 to 12 mice per group). * = p < 0.01 for DETA-NO-treated group or iNO-treated group vs the untreated pneumonia group.
Table 1—Effect of DETA-NO and iNO on Survival of Sham Mice and Mice with P aeruginosa Pneumonia
|Treatment||Dose||Sham Mice||Pneumonia Mice|