Tehran University Medical Journal

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Background: Proteolytic enzymes, especially collagenases, are used for digestion of extracellular matrix, cell isolation and primary culture. Because of the problems in purification and low amount of collagenases in bacterial or animal sources, it is important to find new sources of the enzymes. So, in the present study actinidin, a plentiful protein in kiwifruit was purified and a mixture of actinidin and trypsin was applied to isolate rat aortic endothelial cells. Methods: Aortic endothelial cells were isolated using digestion solution containing different concentrations of actinidin (from 2 to 16 mg/ml) and trypsin (0.3, 0.6, 1.2 and 2.4 mg/ml) in different times (from 15 to 90 minute). Isolated cells were cultured in DMEM culture medium. Isolated cells were identified by morphological characteristics and immunocytochemical staining viability of separated cells was estimated by trypan blue exclusion test. Results: Actinidin in concentration of 10 mg/ml with trypsin in concentration of 1.2 mg/ml for one hour could isolate rat aortic endothelial cells. In this condition the viability of cells was estimated 90%. Morphological and immunocytochemical charac- teristics confirmed the isolated cells as endothelial cells. Conclusion: The results showed that the mentioned mixture of actinidin and trypsin has not considerable toxic effects on separated cells and is a novel and suitable option for isolation of rat aortic endothelial cells

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Background: Coarctation of aorta is narrowing of proximal descending aorta. Interventional procedures such as balloon angioplasty & stent implantation has been progressively in use as alternatives for surgery in increasing number of children with diagnosis of coarctation of aorta. The aim of this study was to evaluate the use of endovascular stent in children with coarctation of aorta.

Methods: We evaluated effectiveness and safety of stenting in all patients younger than 18 years old with coarctation and re-coarctation of aorta which treated by stenting between years 2004-9 at rajaei - heart centre in Tehran, Iran.

Results: we studied 53 patients younger than 18 years old with a follow up of six months. Totally 54 stents were implanted. Mean (±SD) age of the patients was 11.6±4.2yrs. Seventeen cases (32%) were younger than 10 years old, and 36 cases (68%) were 10 years and older. Mean (±SD) weight was 39.24±18kg. 16 cases weighting less than 25kg. Peak systolic pressure gradient (SPG) decreased from 46.26±17.07 to 1.03±0.19mmHg after procedure (p<0.001). There was no significant difference (p<0.001) in the gradient before and after stenting in the patients with native coarctation (Vs re-coarctation cases), less than 25 kg and under 10 years old groups. Complications developed in 44% of cases while dominantly were minor except in two cases re-dilatation of stent was not needed during six month of follow-up of the patients.

Conclusions: Stenting of coarctation of aorta can decrease complications and can be used safely in children weighing bellow 25kg and in children below 10yrs old.