Effects of arterial balloon dilatation papaverine administration and arterial clamping on internal mammary artery endothelial cells morphology: a scanning electron microscopic study

The internal mammary artery has become the conduit of choice for coronary artery bypass grafting. Harvesting of the internal mammary artery [IMA] for use in myocardial revascularization may result in spasm, which can impair early graft flow. Hydrostatic and mechanical dilatation can exert an lntraluminal shear force causing denudation of the IMA endothelium. Performance of a vascular anastomosis or repair requires meticulous, gentle technique and a bloodless operative field. Many vascular surgeons rely on commercial [atrauniatic] vascular clamps for the latter; however, most experimental evidence incriminates clamps as agents of moderate to severe endothelial and medial layer injury. Moreover, Intraluminal papaverine treatment during operation is said to reduce vasospasm and facilitates anastomosis. However, it has been suggested that papaverine may cause intimal damage and accordingly this work investigated endothelial architectural alterations by comparing the effect of balloon dilation, papaverine administration and vascular clamp at 10 and 30 minutes clamping in the internal mammary arteries segments using the scanning electron microscopy. In the present study, the balloon angioplasty was found to be the most detrimental procedure on endoihelial integrity [40% endothelial loss], while the papaverine was the safest procedure during IMA grafting [5% loss]. Endothelial damage following clamping for 10 min was significantly less [mild] 10% loss than that produced by 30 min clamping [moderate] 30% loss

Effects of cyclophosphamide administration on the lung of albino rat and protective role of antioxidants

The present work was designed to study the effects of cyclophosphamide on the albino rat lung, and to demonstrate the possible protective role of the antioxidants. The results revealed that administration of cyclophosphamide [20 mg/ kg b.w.] for one week caused thickening of the alveolar wall with partial detachment and degeneration of type II pneumocytes. Signs of congestion and fibrosis were also detected. Administration of cyclophosphamide [20 mg/kg b.w.] for two weeks caused pleomorphic cellular proliferation and obliteration of the alveolar lumen. Degenerative changes were noticed in both type I and type II pneumocytes. Type I pneumocytes manifested altered nuclear chromatin pattern and vacuolated cytoplasm. Type II pneumocytes showed detached microvilli, irregular cell membrane, pyknotic nucleus and multiple interconnected empty lamellar bodies. Signs of congestion and cellular infiltration by plasma cells, mast cells and neutrophils were noticed with accumulation of thick elongated collagen bundles in the alveolar wall. Administration of the antioxidants [0.1 ml of Antox], minimized the toxic effects of cyclophosphamide and even allowed regeneration of the alveolar wall. Regarding the alveolar pneumocytes, binducleated type II pneumocytes were noticed. Furthermore many pneumocytes acquired features intermediate between type I and type II in an attempt to restore the alveolar wall. Fibrosis and congestion were minimized