Risk of cerebral vasospasm following subarachnoid hemorrhage is associated with endothelial nitric oxide synthase gene polymorphism / 南方医科大学学报

<p><b>OBJECTIVE</b>To study whether endothelial nitric oxide synthase gene (eNOS) polymorphisms is implicated in the development of cerebral vasospasm following subarachnoid hemorrhage.</p><p><b>METHODS</b>Three groups of patients with subarachnoid hemorrhage were selected to test this hypothesis, including 98 patients with cerebral vasospasm following aneurysmal subarachnoid hemorrhage (ASAH), 96 with cerebral vasospasm following traumatic subarachnoid hemorrhage (TSAH), and 195 patients without cerebral vasospasm following aneurysmal or traumatic subarachnoid hemorrhage. The parents of 194 patients and 100 control subjects were also examined for transmission disequilibrium test according to a family-based study design to test the associations.</p><p><b>RESULTS</b>We examined four eNOS gene polymorphisms, and two of these polymorphisms, the T to C substitution in the promoter at position -786 and the a-deletion/b-insertion in intron 4, were found to associate with cerebral vasospasm in subarachnoid hemorrhage in the case-control comparisons. For the former polymorphism, the risk of cerebral vasospasm was higher in C allele homozygotes than in the other two genotypes (odds ratio: 2.8, 95% CI: 1.4 to 5.6); for the latter polymorphism, the a-deletion carriers were exposed to a increased risk (odds ratio: 2.3, 95% CI: 1.3 to 4.0) in comparison with the noncarriers. The two polymorphisms were analyzed together as haplotypes in a family-based study using the transmission disequilibrium test. The C/a-deletion haplotype was transmitted from the heterozygous parents to cases of cerebral vasospasm in subarachnoid hemorrhage with a significantly higher frequency than expected (P=0.005).</p><p><b>CONCLUSION</b>The findings of the case-control and family-based studies clearly demonstrate that DNA sequence differences in eNOS gene influence the risk of cerebral vasospasm in subarachnoid hemorrhage.</p>

Effect of renal artery embolization using 2-poly-hydroxyethyl-methacrylate as a liquid embolic agent: a study in rabbits / 南方医科大学学报

<p><b>OBJECTIVE</b>To assess the effect of a liquid embolic agent 2-poly-hydroxyethyl -methacrylate (2-P-HEMA) for renal artery embolization in rabbits.</p><p><b>METHODS</b>The precipitation time of different concentrations (2%, 3.5%, 5%, 6.5%, 8% and 9.5%) of 2-P-HEMA dissolved in different solutions (ethanol, ethanol/iobitridol, and ethanol/Bi2O3) were determined in flowing water. The mixtures of 2-P-HEMA (2%, 5%, and 8%) with ethanol/ Bi2O3 were injected into the renal arteries of the rabbits, and the artery-embolizing effects were assessed using angiography at 2 and 12 weeks after the injection, with also macroscopic and microscopic examination of the embolized kidneys.</p><p><b>RESULTS</b>The mixtures of 2-P-HEMA and ethanol formed flocculent precipitation a few seconds after injection into flowing water, and the precipitation time showed no significant variations with the concentration of 2-P-HEMA in the mixture. Low and moderate concentrations of 2-P-HEMA could pass through the microcatheter smoothly with little injection resistance, and resulted in complete occlusion of the renal arteries without adhesion to the microcatheter. Angiography at 2 and 12 weeks detected no recanalization of the occluded renal arteries. Macroscopically, the lumen of the renal arteries was found to be occluded by the embolic agents, and deep penetration of the embolic agents into the glomerular arteries was observed microscopically. The mixture containing high-concentration 2-P-HEMA was difficult to deliver through the microcatheter due to high injection resistance.</p><p><b>CONCLUSION</b>2-P-HEMA can be rapidly precipitated after injection into flowing water, and allows complete embolization of the renal arteries of rabbits at proper concentrations, suggesting its great potential as an endovascular liquid embolic agent.</p>

Biocompatibility of polyurethane-BaFe(12)O(19 ) composite microsphere as a new endovascular embolization material / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the biocompatibility of polyurethane-BaFe(12)O(19) magnetic composite microsphere as a new endovascular embolization material.</p><p><b>METHODS</b>The biocompatibility of BaFe(12)O(19) particle was evaluated in vitro using Ames test, cell toxicity test, acute and subacute systemic toxicity test, hemolysis test, bleeding time and clotting time test and blood clotting function assay.</p><p><b>RESULTS</b>Ames test showed that the MR values of this particle leaching solution were all less than 2 without mutagenicity. Cell toxicity test showed that leaching solution at different concentrations had grade I toxicity on L929 cells. Acute and subacute systemic toxicity test showed that the experimental animals had good general condition without obvious pathological abnormality. The hemolysis rate of experimental group was 2.43%, which met the ISO standard (no more than 5%). The bleeding time and clotting time in mice were comparable between the experimental group and control group (P>0.05). There were no significant differences in blood clotting function between experimental group and control group (P>0.05).</p><p><b>CONCLUSION</b>The material has no obvious toxicity or mutagenicity, and does not cause hemolysis or hemopexis or affect the bleeding time and clotting time. Polyurethane-BaFe(12)O( 19) particle possesses satisfactory biocompatibility.</p>

Study on intraluminal embolization with microcoils treating traumatic pseudoaneurysms in common carotid artery in rabbits / 中华创伤杂志(英文版)

<p><b>OBJECTIVE</b>To evaluate the long-term effect of endovascular occlusion with microcoils on traumatic pseudoaneurysms (TPAs) in the common carotid artery in rabbits.</p><p><b>METHODS</b>TPAs in the right common carotid artery were surgically made in 16 rabbits. At 3-4 weeks after operation, the survived 12 models were randomly divided into a control group (n=3) with no treatment and an experimental group (n=9), in which TPAs were intraluminally embolized with microcoils and corresponding therapy was given. Three months after embolization, the TPAs were examined with digital subtraction angiography and pathology.</p><p><b>RESULTS</b>The 3 rabbits in the control group all died of rupture of TPA. Among the 9 TPAs occluded with microcoils, 4 were completely occluded, 4 were partially occluded, and 1 was excluded due to the microcoils migrating into the parent artery. Three months after embolization, the 4 TPAs which were completely occluded remained obliterated as determined by digital subtraction angiographic findings. The parent artery remained unobstructed and the structure of the TPAs were replaced by a mass of scar tissues. The 4 TPAs which were partially occluded remained unruptured and the microcoils were compressed.</p><p><b>CONCLUSIONS</b>The lumen in TPA can be completely occluded by microcoils and the parent artery is unblocked. Partial occlusion of the lumen can also prevent the rupture of TPA.</p>