Résumé
AIM: Although endovascular radiotherapy inhibits neointimal hyperplasia, the exact alterations induced by ?-particles irradiation remain to be elucidated. The objective of this study was to investigate the ability and the cellular mechanism of local ?-particles emission from 188 Re to inhibit vascular smooth muscle cells (SMCs).METHODS: The SMCs in vitro were irradiated by 188 Re with single doses of 2.6 Gy-25.8 Gy. The effects of ?-particles on SMCs, such as effective irradiate doses, the period of inhibition for SMCs proliferation, the changes of cell proliferation rate and DNA synthesis rate, cell cycle progression and related gene expression, were investigated by cell count,-TdR incorporation, cell cycle progression analysis, cell viability and immunocytochemistry, respectivecy.RESULTS: ?-particles irradiation with dose of 5.2 Gy could inhibit significantly SMCs proliferation. At dose of 20.6 Gy DNA synthesis inhibitory rate was 92%, SMCs proliferation rate was only 3%. Renoval of 188 Re did not abolish the inhibitory effects of ?-particles on SMCs proliferation. The expression of P53 was up regulation and PCNA was down regulation after irradiation. CONCLUSION: ?-particles from 188 Re was significantly effective and permanent in inhibiting SMCs proliferation, and inhibitory effect was in dose-dependet manner ED50 was 5 Gy, the best dose to inhibit SMCs proliferation was 20 Gy. ?-particles irradiation induced SMCs to occur G 0/G 1 arrest, damaged the ability of SMCs reproliferation and led to cell clonogenic death. P53 and PCNA had regulatiory effects on SMCs proliferation after ?-particles irradiation.
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Objective This study was to evaluate the effects of endovascular irradiation on the proliferation response of injured artery Methods The bilateral iliac arteries of thirty normal fed New Zealand white rabbits were injured by balloon overdilatation (balloon to artery ratio was 1 54∶1) In one iliac artery endovascular irradiation was carried out by a perfusion balloon inflated with 32 P solution The contralateral iliac artery served as an intraanimal control Three doses schedules were studied: 10Gy, 20Gy and 40Gy, 10 rabbits per group Digital angiographic image was made before and after balloon overdilatation as well as at the end of 4 week follow up Subsequently, the iliac arteries injured were excised to be stained with weigert massion for hisopathologic analysis Results The iliac arteries injury of three group rabbits showed certain stenosis at the end of 4 week follow up ( P 0 05) Histopathologic analysis of irradiated arteries exhibited the decreased neointimal proliferation compared with the control both in 20Gy and 40Gy high dose radiation groups ( P 0 05) Conclusion The experimental restenosis like model can be established using overstretch balloon to injure the iliac artery of normal diet rabbit The dose from 20Gy to 40Gy of endovascular irradiation inhibited neointimal proliferation after artery injury The improvement of arterial stenosis was not observed
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AIM: To investigate affection of the novel Ginko biloba extract GBE50 on bcl-2、bcl-xL gene expression in rabbit myocardium. METHODS: Adult male New Zealand rabbits were randomly divided into 2 groups. GBE50 group were orally administrated with 100 mg/kg GBE50 daily. Control group were only administrated vehicle 2% CMC-Na. After being raised for 4 weeks, the animals were killed and the ventricular tissue were excised. We performed reverse transcriptase polymerase (RT-PCR) to measure gene expression of bcl-2、bcl-xL. Semiquantitative analysis method based on gel electrophoresis image was adopted to compare gene expression among groups. RESULTS : The gene expression of bcl-2、bcl-xL significantly increased in GBE50 group compared with control group. CONCLUSION: The novel Ginko biloba extract GBE50 can promote expression of the antiapoptotic gene bcl-2、bcl-xL in rabbit myocardium.
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Transcatheter atrioventricular (AV) junction ablation with radiofrequency energy was performed in five patients with AV nodal reentrant tachycardia. Disappearance of ventriculoa-trial condcution in all patients was showed and no dual pathway was observed in four patients, in whom three patients occurred first degree AV block after ablation. No tachycardia was showed in all patients in the electrophysiology test and in follow-up of 1. 5-12. 5 months. The results sug-gested that the application of radiofrequency energy may be a suitable and safe therapeutic mothed for modification of AV nodal conduction in patients with AV nodal reentrant tachycardia.
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AIM: To explore the effect of insulin on the proliferation and expression of transforming growth factor ? 1 (TGF ? 1) and its receptors in aortic vascular smooth muscle cells (VSMC) from spontaneously hypertensive rats (SHR) and from the normotensive Wistar-Kyoto(WKY) rats. METHODS: VSMCs from aortas of WKY rats and SHR were prepared by an explant method. The effect of insulin on VSMC proliferation were measured by cell counting and flow cytometry analysis, respectively. Quantitative reverse transcription polymerase chain reaction (RT-PCR) technique was used to probe TGF ? 1 and its receptor mRNA on VSMC. RESULTS: Insulin enhanced the proliferation of VSMC from SHR in a dose-dependent manner ( P 0 05). CONCLUSIONS: The responses to insulin of TGF ? 1 and its receptor in SHR and WKY are significantly different. This abnormal regulation by insulin may be associated with an exaggerated proliferative response in SHR derived cells.