Postoperative histopathologic study of rabbit's maxillary sinus

This study was performed on 21 healthy rabbits divided into three groups of nasoantral window, ostioplasty and radical antrostomy. One sinus was operated upon and the other side served as control. Exploration was performed after six weeks to record the changes in the size and contents of the sinus cavity as well as the state of the natural and/or artificial window. Then, the animals were sacrificed and their heads were processed for histopathologic evaluation of the cavity, mucosa and submucosa. It was noticed that artificial nasoantral window was associated with high rates of window closure and it did not preclude postoperative infection. Ostioplasty was followed by the least rate of cavity contraction and suppuration. However, it resulted in noticeable changes at the natural ostium. Radical antrostomy was associated with the highest incidence of mucosal and submucosal abnormalities as well as a high infection rate

Modulatory effect of L - arginine [nitric oxide precursor] on aspirin - induced changes in gastric mucosa and motility in rats.

In this study, L-arginine was administrated orally [p.o.] at a dosage of 10, 20 and 40 mg/kg of body weight, acutely once and chronically daily throughout two weeks prior to ulcer induction. Gastric mucosal lesion was induced by single oral administration of aspirin 300 mg/kg body weight suspected in water, after 36 hours fasting. The rats were killed within 24-48 hours and the gastrointestinal tract was subjected to gastric motility study and examined for the evidence of gross or microscopic change. The obtained results indicated the relaxant effect of L-arginine on gastric fundus and its protective role against the aspirin-induced ulcers in the rat