Pretreatment with H(2) O(2) alleviates aluminum-induced oxidative stress in wheat seedlings.

Hydrogen peroxide (H(2) O(2) ) is a key reactive oxygen species (ROS) in signal transduction pathways leading to activation of plant defenses against biotic and abiotic stresses. In this study, we investigated the effects of H(2) O(2) pretreatment on aluminum (Al) induced antioxidant responses in root tips of two wheat (Triticum aestivum L.) genotypes, Yangmai-5 (Al-sensitive) and Jian-864 (Al-tolerant). Al increased accumulation of H(2) O(2) and O(2) (•-) leading to more predominant lipid peroxidation, programmed cell death and root elongation inhibition in Yangmai-5 than in Jian-864. However, H(2) O(2) pretreatment alleviated Al-induced deleterious effects in both genotypes. Under Al stress, H(2) O(2) pretreatment increased the activities of superoxide dismutase, catalase, peroxidase, ascorbate peroxidase and monodehydroascorbate reductase, glutathione reductase and glutathione peroxidase as well as the levels of ascorbate and glutathione more significantly in Yangmai-5 than in Jian-864. Furthermore, H(2) O(2) pretreatment also increased the total antioxidant capacity evaluated as the 2, 2-diphenyl-1-picrylhydrazyl-radical scavenging activity and the ferric reducing/antioxidant power more significantly in Yangmai-5 than in Jian-864. Therefore, we conclude that H(2) O(2) pretreatment improves wheat Al acclimation during subsequent Al exposure by enhancing the antioxidant defense capacity, which prevents ROS accumulation, and that the enhancement is greater in the Al-sensitive genotype than in the Al-tolerant genotype.

[The clinical report of 21 cases of occlusion of atrial septal defect through right chest small incision].

OBJECTIVE: To evaluate the methods and efficacy of atrial septal defect (ASD) occlusion through right chest incision. METHODS: The clinical data of 21 patients with ASD from July 2004 to May 2005 were analyzed retrospectively. Eight patients were male and 13 patients were female, aged from 1 to 70 years old, with the median age of 21 years old. The diameter of ASD was from 8 to 40 mm. All the 21 patients were under general anaesthesia. A 2 to 3 cm incision was made in the 4th intercostals of right side of sternum. With the help of transesophageal or normal transthoracic echocardiography, the occluder was released using monotube unit. RESULTS: All cases were occluded successfully without death. The types of the occluder were from 14 to 46 mm. None failed and had to choose extracorporeal circulation operations. No transfusion and no serious complication such as the occluder dislocated occurred. And no evident of atrial shunt was found when in review echo. CONCLUSIONS: The ASD occlusion through right chest minimal incision is safe, credit, minimal invasive and worth to use widely.