Objective To study the effects of zinc-metallothionein (ZnMT) on the cadmium-induced oxidative damage of liver and kidney in mice. Methods The model of laboratory animal was established by 14 d-cadmium exposure to Kunming mice. Then the cadmium-poisoning mice were grouped as Cd-ZnMT group and Cd-ZnSO4 group and perfused orally by solution of ZnMT and ZnSO4 for 14 days respectively. The morphological changes of liver and kidney were observed by electron microscope. The contents of malonydiadehyde (MDA), the activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) in supernatant fluid of liver and kidney were determined. Results The decreases of the contents of MDA, the increases of the activities of SOD and GSH-Px in liver and kidney of mice in Cd-ZnMT and Cd-ZnSO4-exposure group were observed compared with those in cadmium-exposure group, the dose-effect relationships were also found. The increases of the activities of SOD and GSH-Px, the decrease of contents of MDA of liver and kidney, were found in Cd-ZnMT-exposure group compared with those of Cd-ZnSO4-exposure group, but without statistical significances. The morphological damages of liver and kidney observed by electron microscope in mice of cadmium-exposure group were more serious than those in mice treated with solution of ZnMT and ZnSO4 after cadmium exposure. Conclusion ZnMT could repair the lipid peroxidative damages in liver and kidney in mice induced by exposure to cadmium in a certain degree.

The progress of mainly experimental studies on the chronic toxicity test of the automobile exhaust-involving reproductive system impairment, chronic lung impairment and lung cancer in this paper, and the general situation and the progress on the latest domestic and foreign studies on the possiblely multiple mechanisms of automobile exhaust-induced chronic toxicity are introduced. Some epidemiological study results on the automobile exhausts-induced chronic impairments are reviewed, as well as some problems required to be explored further in the occupational risk assessment of exposure to automobile exhausts in recent years.

Objective To explore the effects of prenatal exposure to lead on learning and memory of rats' offspring. Methods The pregnant rats were randomly divided into 4 groups provided with double evaporated water, 50, 100 and 200 mg/L lead acetate solution via drinking water respectively. The lead-exposure period for exposure groups was limited from the 1st day after pregnancy to the 20th day when the offspring began to be weaned. For learning ability 20-day old offspring were tested by water maze. For active learning and memory ability, the 20-day old, 40-day old and 60-day old offspring were tested by Y maze. Results The frequency of the mistakes in water maze made by offspring increased with the increase of the prenatal lead-exposure doses of their mothers and showed significantly higher levels in 100 and 200 mg/L groups compared with that of control group (P0.05). But the qualified rates of 0-min and 24-h escape for 100 and 200 mg/L groups showed sigificantly lower levels compared with that of control group when they were 60-day old (P

Objective To observe the toxicity of diesel exhaust particles extracts(DEPE) on V79 cell in cell viability, membrane and oxidative stress. Methods Cell exposed different concentrations of DEPE for different time , the change of cell viability, the leakage of intracellular lactate dehydrogenase(LDH), intracellular glutathione(GSH) and glutathione peroxidase (GPX)content were determined respectively, and analyzed the relation between GSH and GPX. Results The results showed that the viability of V79 cell decreased and the leakage rate of lactate dehydrogenase increased gradually in according with the increasing dosage of DEPE,and that DEPE could impair V79 cell by oxidative stress, included intracellular GSH content decreased and the activity of GPX increased, indicating that GPX might play a important role in DEPE induced GSH depletion. Conclusion DEPE may impair cell viability and the cell membrane integrity, also impair cell by oxidative stress.

Objective To study the process of stent graft implantation into the aortic dissection model by finite element simulation, calculate the stress distribution at different locations of the aorta after the implantation, and analyze the biomechanical mechanism of new lesions for implantation of stent grafts. Methods Based on the computed tomography angiography (CTA) image data of the aorta, a three-dimensional geometric model of patient-specific aortic dissection was established with image segmentation and reconstruction. The wall thickness and material properties of the aortic dissection of the computational models were set according to the literature data. Stent grafting rings with different geometric parameters were designed in a computer-aided design (CAD) software, and the procedure of stent graft implantation was simulated by a finite element analysis software. Results When the implanted stent graft reached a steady-state, the maximum Von Mises stress of the aorta was markedly related to the position of the stent graft and located at the bare stent or small nickel-titanium alloy ring. In the long-term, this force might cause a new tear to appear at the treated aorta. Conclusions The position of the stent graft had a weak effect on the distribution of the maximum Von Mises stress of the aorta, but there was an obvious effect on the Von Mises stress of the aorta. These research outcomes may provide significant guidance for selecting the position of the stent graft.

Numerical simulation of stent deployment is very important to the surgical planning and risk assess of the interventional treatment for the cardio-cerebrovascular diseases. Our group developed a framework to deploy the braided stent and the stent graft virtually by finite element simulation. By using the framework, the whole process of the deployment of the flow diverter to treat a cerebral aneurysm was simulated, and the deformation of the parent artery and the distributions of the stress in the parent artery wall were investigated. The results provided some information to improve the intervention of cerebral aneurysm and optimize the design of the flow diverter. Furthermore, the whole process of the deployment of the stent graft to treat an aortic dissection was simulated, and the distributions of the stress in the aortic wall were investigated when the different oversize ratio of the stent graft was selected. The simulation results proved that the maximum stress located at the position where the bare metal ring touched the artery wall. The results also can be applied to improve the intervention of the aortic dissection and the design of the stent graft.
Arteries ; Blood Vessel Prosthesis Implantation ; Cardiovascular Diseases ; Computer Simulation ; Finite Element Analysis ; Humans ; Prosthesis Design ; Stents