Oxidation of isopropanol by rat liver microsomes: possible role of hydroxyl radicals

Isopropanol, a branched chain alcohol, served as a substrate for the microsomal alcohol oxidizing system. Isopropanol oxidation required NADPH; H₂O₂ or an H₂O₂-generating system did not effectively support isopropanol oxidation, indicating that isopropanol was not a substrate for the peroxidatic activity of catalase. The addition of azide by itself or H₂O₂ (in the presence of azide and NADPH) stimulated isopropanol oxidation, suggesting a pivotal, indirect role for H₂O₂ in the system. H₂O₂ may serve as a precursor of hydroxyl radicals. Accordingly, the oxidation of isopropanol was inhibited by hydroxyl radical scavenging agents, namely dimethylsulfoxide, mannitol, benzoate and 2-keto-4-thiomethylbutyric acid. Fe-EDTA, which is known to increase hydroxyl radical generation, stimulated the oxidation of isopropanol. The stimulation by Fe-EDTA was blocked by competing hydroxyl radical scavengers. Model hydroxyl radical generating systems such as the coupled oxidation of xanthine by xanthine oxidase, especially in the presence of Fe-EDTA, or the autoxidation of ascorbate in the presence of Fe-EDTA could also oxidize isopropanol. These results indicate that (a) rat liver microsomes are capable of oxidizing branched chain alcohols, and (b) hydroxyl radicals or a species with the oxidizing power of the hydroxyl radical, generated from microsomal electron transfer, may play a role in isopropanol oxidation.     

Internal fixation of a segmental fracture of the femur with a Küntscher-Herzog tibial nail

This article presents the technique and the results of internal fixation of a severely unstable and displaced segmental fracture with a Küntscher-Herzog tibial nai in a young patient with associated multiple fractures.     

育亨宾对雄性瑞士白化小鼠的生殖、细胞和生化毒性(英文)

目的:研究育亨宾(Yohimbe)对瑞士白化小鼠生殖细胞的影响。方法:用不同剂量(188,375和750mg/[kg·day])的育亨宾水性悬浮液灌胃处理成年雄性小鼠,持续90天。检测下面的参数:(1)生殖器官重量,(2)精子的活动力和数量,(3)怀孕率和平均受精卵附着数,(4)精子形态,(5)睾丸染色体的细胞学,(6)蛋白质,RNA,DNA,丙二醛,非蛋白质的硫氢化合物(NP-SH)和激素的生化评估。结果:育亨宾处理使精囊重量、精子的活动性和精子数量、受精卵附着前和受精卵附着后的重量的显著增加,雄性生殖能力降低。精子畸形和染色体变异方面的数据进一步证实了这一结果。生化评估数据也显示睾丸细胞中的丙二醛,NP-SH 的消耗,蛋白质,RNA 和 DNA 增加了。结论:本研究结果表明,自由基可能是通过 yohimbine(Yohimbe 的主要成分)对神经传递素,包括去甲肾上腺素的影响产生细胞毒性和生殖毒性。这些数据提示要谨慎使用 Yohimbe。     

Fractured tracheostomy tube in the tracheo-bronchial tree

Tracheostomy is a life saving procedure and many a times patients are discharged with permanent tracheostomy tubes. However, fracture of tracheostomy tube with subsequent migration into the tracheobronchial tree is uncommon and carries the potentially fatal risk of respiratory obstruction. In this report, a case of a 6-year-old boy is presented, who had aspirated a fractured tracheostomy tube which had lodged in the left bronchus.