IL-8 (OptEIA, rabbit IL-8 set; Pharmingen; San Diego, CA) and VEGF (R&D Systems; Minneapolis, MN) were measured by enzyme-linked immunosorbent assay according to the manufacturers’ directions. Quantification of IL-8 and VEGF was done by comparison of the optical density in the enzyme-linked immunosorbent assay reader (Power Wave; Bio-Tek; Winooski, VT) using a 450-nm filter with the optical density of controls.
The data are expressed as the mean ± SD. Statistical analyses were performed using statistical computer software (SigmaStat; SPSS; San Rafael, CA). One-way analysis of variance was used to compare the levels among subgroups, and the Tukey test was used to perform multiple comparison procedures. If the log-transformed data did not satisfy the normality and equal variance tests, Kruskal-Wallis one-way analysis of variance on ranks was used to compare the levels among subgroups, and the Dunn method was used to perform multiple comparison procedures. Paired t tests were used to compare the cytokine levels in the blood and pleural fluid. Linear regression was used to analyze the relationship between the serum cytokine (dependent variable) and the pleural fluid cytokine level. A p value of < 0.05 was accepted as being significant. www.help-at-diabetes.com
Leukocytes: The intrapleural injection of all three agents led to an increase in the peripheral WBC count, but only the WBC count at 6 h after TL injection (10 ± 3.3 X 103 cells/mm) was significantly higher than the control value (5.1 ± 1.3 X 103 cells/mm) [p < 0.05]. The comparison among injected groups at different times showed no significant differences in WBC count (Fig 1). Neutrophils: As observed with the blood WBC count, the percentage of blood neutrophils also was increased 6 h after the injection of each of the three agents, but only the TL group (73 ± 11%) differed significantly from the control group (53 ± 7%; p < 0.05). Subsequently, the percentage of neutrophils decreased with time in the TL group, and after 48 h the SN group had a significantly higher mean percentage of neutrophils than did the TL group (55 ± 14% vs 29 ± 9%, respectively). When changes with time in the neutrophil counts in the different groups were analyzed, the neutrophil counts in both the TL and SN groups tended to decrease with time (Fig 2).
Figure 1. Blood WBC count in controls, and in rabbits injected with saline solution, TL, and SN. * = p < 0.05 compared with TL-injected rabbits 6 h after injection.
Figure 2. Blood neutrophil percentages in controls, and rabbits injected with saline solution, TL, and SN. * = p < 0.05 (TL group at 6 h vs control, saline solution at 6 h, and the TL group at 24 and 48 h); # = p < 0.05 (TL group at 24 h vs TL group at 48 h and the SN group at 24 h); x = p < 0.05 (SN group at 6 h vs SN group at 24 h); + = p < 0.05 (SN group at 48 h vs TL group at 48 h).