Effect of pentoxifylline and 5-fluorouracil/triamcinolone on laryngotracheal stenosis developing as a complication of tracheostomy: study in rats.

We aimed to investigate the prophylactic effect of pentoxifylline (PTX) and 5-fluorouracil (5-FU) on laryngotracheal stenosis in tracheotomised rats by evaluating blood glutathione peroxidase (GPx) and superoxide dismutase activities and by histopathological evaluation of laryngotracheal segment. Randomized prospective single-blind study. Standard vertical tracheotomy was performed on 24 rats. Then, the animals were randomly divided into three groups. Intraperitoneal PTX administered to group A (study group) for 10 days. 5-FU was injected in paratracheal tissues in group B (study group) for 10 days. In group C (control group), intraperitoneal saline was administered for 10 days. After 10 days, tracheal cannules were removed. For biochemical analysis, two blood samples were obtained. Three weeks later, all animals were euthanized and trachea specimens were harvested. Stenosis index and mean wall thickness in PTX group were lower as compared to other groups but the difference was statistically insignificant. Minimum inflammation and fibrosis plus maximum epithelial regeneration were seen in PTX group. In addition, GPx activity was at highest level in PTX group and a statistically significant difference was found between control and PTX groups (P = 0.024) though the difference between remaining groups was statistically insignificant (P = 0.121). Superoxide dismutase activity was highest in PTX group but no statistically significant difference was found between the three groups (P = 0.305). The administration of PTX increases GPx activity and it may have some effect on tracheal scar formation which develops following tracheostomy.

Jab1 expression is associated with TGF-ß1 signaling in chronic rhinosinusitis and nasal polyposis.

Jab1, which is a fifth component of COP9 signalosome, plays an essential role in cell growth and proliferation. Jab1 is also shown to regulate transforming growth factor-beta (TGF-ß) signaling in carcinoma cells. The aim of the present study was to investigate the expression and the correlation of Jab1 and TGF-ß1 in chronic rhinosinusitis and nasal polyposis. Here, we show the elevated expression of Jab1 and TGF-ß1 in diseased mucosa without nasal polyps and a correlation between Jab1 and TGF-ß1 expression. Forty-six samples (26 patients with nasal polyps, 10 patients with chronic rhinosinusitis and 10 control subjects) were included to this study. Immunohistochemistry and Western blotting were performed for the assessment of Jab1 and TGF-ß1 localization and the expression of proteins. Double staining of both proteins showed that Jab1 and TGF-ß1 were colocalized in the epithelium, inflammatory cells and the vascular endothelium of nasal mucosa. There was a significant increase in the expression of TGF-ß1 and Jab1 in patients without nasal polyps and a significant decrease in patients with nasal polyps compared to controls. Moreover, correlation was detected between the expression of Jab1 and TGF-ß1 in chronic rhinosinusitis and nasal polyposis. Our results demonstrate that chronic rhinosinusitis is characterized by elevated expression of Jab1 and TGF-ß1 compared to nasal polyposis and Jab1 may play a vital role in the pathogenesis of both chronic rhinosinusitis and nasal polyposis.