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Background and Objective: Irreversible electroporation is a new treatment modality for skin tumors ablation. In order to successful treatment, all of tumoral tissues must be exposed to intense electric field. In addition, the heat that produced during the surgery has adverse effect on recovery procedure. This study was done to evaluate the thermal distribution in ablation of squamous cell carcinoma skin tumors using irreversible electroporation. Materials and Methods: In this study numerical modeling by finite element was used for determination of electrical and thermal distribution in healthy and tumoral tissues. Three-Dimensional Model was done using MR imaging of patient with squamous cell carcinoma in FEMLAB v3.5a software. Electric field distribution determined using Laplace equation and distribution of thermal damage calculated using bioheat equation and Arrhenius equation. This calculation was done for different geometry parameters of needle and plate electrodes. Results: Thermal damage of first-degree burn was not observed in any cases. However in high voltage, volume with temperature above 43˚C reach to 10% of tumoral tissue and 3% of healthy tissue. The study show that the voltage applied to the electrodes and the distance between the electrodes can have the greatest impact on the thermal and electrical distributions. Although needle electrode showed better electric coverage in tumoral area. Conclusion: This study showed that it can be possible to select optimized electric and geometric parameter to select electrode for complete tumor ablation, control of thermal damage in tumoral and healthy tissues.

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Background and Objective: Helicobacter pylori infection is one of the most common chronic bacterial infections all over the world, particularly in the developing countries. LeoA gene plays an important role in pathogenesis, and the main role of this gene is to increase the bacterial toxin secretion. This study was conducted to isolate and clone the leoA gene in a pEGFP-C2 expression vector and evaluate its expression in eukaryotic system.
Methods: In this laboratory study, the leoA gene was amplified from the standard strain of Helicobacter pylori genome (ATCC 43504) by PCR method. It was then inserted into the pTZ vector by cloning T/A. Sub cloning of this gene was performed in a pEGFP-C2 expression vector with a ligase enzyme. The final structure of pEGFP-C2-leoA was transformed by electroporation in CHO (Chinese hamster ovary) cells and the expression of the leoA gene was evaluated by SDS-PAGE and RT-PCR.
Results: The results of PCR indicated that the 1758 bp fragment was amplified from the leoA gene. Cloning of this gene was performed successfully in pTZ and pEGFP-C2 vectors, respectively. The enzyme digestion with two KpnI and SacII enzymes, as well as sequencing, confirmed the accuracy of gene cloning. The observation of the protein product of the leoA gene in CHO cells indicated the successful expression of the LeoA gene in the eukaryotic system of Helicobacter pylori.
Conclusion: The final construct of pEGFP-C2-leoA had a successful expression of the leoA gene in animal cells.