Chinese Med J Peking
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Chinese Med J Peking · Feb 2008
A finite element analysis of the pelvic reconstruction using fibular transplantation fixed with four different rod-screw systems after type I resection.
The pelvis often needs to be reconstructed after bone tumor resection. A major challenge here for the orthopedic surgeons is to choose a method that gives the best performance which depends upon its biomechanical properties. In this study, a 3-dimensional finite element analysis (FEA) was used to analyze the biomechanical properties of reconstructed pelvis using fibula transplant fixed by four commonly used rod-screw systems. ⋯ According to the stability and stress concentration, the method of L5-S1 HR fixation combined with fibula transplantation is better than other fixation methods in pelvic reconstruction after type I resection.
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Isoflurane, a commonly used inhaled anesthetic, induces apoptosis in primary rat cortical neurons of rat in a concentration- and time-dependent manner by an unknown mechanism. We hypothesized that isoflurane induced apoptosis by causing abnormal calcium release from the endoplasmic reticulum (ER) via activation of inositol 1, 4, 5-trisphosphate (IP(3)) receptors. Sevoflurane has a reduced ability to disrupt intracellular calcium homeostasis and is a less potent cytotoxic agent. This study examined and compared the cytotoxic effects of isoflurane and sevoflurane on rat primary cortical neurons and their relationship with disruption of intracellular calcium homeostasis and production of reactive oxygen species (ROS). ⋯ These results suggested that isoflurane induced elevation in [Ca(2+)](c), partially via elevated activity of IP(3) receptors, which rendered cells vulnerable to isoflurane neurotoxicity. ROS production was not involved in isoflurane-induced neurotoxicity. Sevoflurane, at an equivalent exposure to isoflurane, did not induce similar elevations of [Ca(2+)](c) or neurotoxicity in primary cortical neurons of rat.
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Chinese Med J Peking · Feb 2008
Hemin, a heme oxygenase-1 inducer, improves aortic endothelial dysfunction in insulin resistant rats.
Under an insulin resistance (IR) state, overproduction of reactive oxygen species (ROS) may be playing a major role in the pathogenesis of endothelial dysfunction, hypertension and atherosclerosis. Recently, increasing attention has been drawn to the beneficial effects of heme oxygenase-1 (HO-1) in the cardiovascular system. This study aimed to investigate the effects of HO-1 on vascular function of thoracic aorta in IR rats and demonstrate the probable mechanisms of HO-1 against endothelial dysfunction in IR states. ⋯ The endothelial dysfunction in the aorta is present in the IR state. The protective effects of HO-1 against aortic endothelial dysfunction may be due to its antioxidation and regulative effect of vasoactive substances. It is proposed that hemin, inducer of HO-1, could be a potential therapeutic option for vascular dysfunction in IR states.