Change and role of heme oxygenase-1 in injured lungs following limb ischemia/reperfusion in rats / 中华创伤杂志(英文版)

<p><b>OBJECTIVE</b>To study the change and role of heme oxygenase-1 (HO-1) in injured lungs following limb ischemia/reperfusion in rats.</p><p><b>METHODS</b>A total of 96 healthy male Sprague-Dawley rats, weighing 250-300 g, were used in this study. Hind limb ischemia was made on 40 rats through clamping the infrarenal aorta for 2 hours with a microvascular clip, then limb reperfusion for 0, 4, 8, 16 and 24 hours (n=8 in each time point) was performed, respectively. Other 8 rats undergoing full surgical operation including isolation of the infrarenal aorta without occlusion were taken as the sham operation group. Lung tissues were obtained from the 48 animals and Northern blotting and Western blotting were employed to measure the changes of HO-1 mRNA and protein expression, respectively. Immunohistochemistry technique was used to determine the cell types responsible for HO-1 expression after limb ischemia/reperfusion. Then hind limb ischemia was made on other 12 rats through clamping the infrarenal aorta for 2 hours with a microvascular clip, among whom, 6 rats were given zinc protoporphyrin (ZnPP), an inhibitor of HO. Then limb reperfusion for 16 hours was performed on all the 12 rats. And other 12 rats underwent full surgical operation including isolation of the infrarenal aorta without occlusion, among whom, 6 rats were then given ZnPP. Then lung tissues were obtained from the 24 animals and lung injury markers, lung histology, polymorphonuclear leukocyte (PMN) count and malondialdehyde (MDA) content were detected, respectively. HO activity was determined through measuring the carboxyhemoglobin (COHb) level in artery blood with a CO-oximeter after limb ischemia/reperfusion. And the animal mortality was observed on the other 24 rats.</p><p><b>RESULTS</b>Northern blotting analysis showed that HO-1 mRNA increased significantly at 4 hours after reperfusion, peaked at 16 hours, and began to decrease at 24 hours. In contrast, no positive signal was observed in the sham and simple ischemia animals. Increased HO-1 mRNA levels were accompanied by similar increases in HO-1 protein. Lung PMNs and MDA content increased significantly at 4, 8, 16 and 24 hours after reperfusion, compared with the sham controls (P<0.001), while they decreased in rats with reperfusion for 16 hours when compared with rats with reperfusion for 4 hours (P<0.001). Immunohistochemical studies showed that HO-1 was expressed in a variety of cell types, including the airway epithelia, alveolar macrophages and vascular smooth muscular cells. The blood COHb level and animal mortality increased significantly after limb ischemia/reperfusion compared with the sham controls (P<0.001). ZnPP administrated to the ischemia/reperfusion animals led to a decrease in the COHb level and an increase in lung PMN number, MDA content and animal mortality (P<0.001 compared with ischemia/reperfusion group), and the lung injury was aggravated.</p><p><b>CONCLUSIONS</b>Limb ischemia/reperfusion up-regulates pulmonary HO-1 expression, which serves as a compensatory protective response to the ischemia/reperfusion-induced lung injury in rats.</p>

Treatment of extremity infections with soft tissue defects with the ramified musculocutaneous flap pedicled with the descending branch of lateral circumflex femoral artery / 中华显微外科杂志

Objective To discuss the clinical effect of the ramified musculocutaneous flap pedicled with the descending branch of lateral circumflex femoral artery treatment of bones and arthrsis of extremity in- fections with soft tissue defects.Methods The muscle flap blooded with the muscular branch of lateral fem- oral muscle and musculocutaneous flap blooded with the musculocutaneous branch were designed,all of which were pedicled with the descending branch of lateral circumflex femoral arteryIn clinic24 cases of bones and arthrosis of extremity infections with soft tissue defects were treated with this kind of ramified musculocutaneous flap.Results Of the 24 cases23 cases were survived while 1 case was lost16 cases were healed at stageⅠ8 cases were healed at stageⅡSinus has formated in 3 casesone of which twicebut they were healed in one year with the treatment of debridmentsFour cases with osteomvelitis and bone defect were treated with bone grafting in the later 6～8 months after the wound has healedTwenty-two cases were followed-up for 6～20 monthsinfcetiou didn't recur.Conclusion This kind of ramified musculocutaneous flap has such ad- vantages as longer blood vessel pediclefilling the defects completely flexible application and stronger anti-in- fectionthat it may be an effective way in treating bones and arthrosises of extremity infections with soft tissue defects.