Cell Journal (Yakhteh)

7-18

Authors: Jamileh Nowroozi , Abbas Akhavan Sepahi , Afrooz Rashnonejad

Objective: Pyocyanine plays an important role in the pathogenesis of Pseudomonas aeruginosa, (P. aeruginosa) and is known to have inhibitory and bactericidal effects. This study has aimed to detect the phenazine biosynthetic operon (phz ABCDEFG) and two phenazine modifying genes (phzM and phzS) by polymerase chain reaction (PCR) and detection of its possible protein bands by sodium dodecyl sulfate - polyacrylamide gel electrophoresis (SDS-PAGE). The antimicrobial effects of pyocyanine alone and mixed with colloidal silver nanoparticles were studied. Materials and Methods: In this descriptive study, clinical and environmental species of P. aeruginosa were isolated by thioglycollate medium culture and cetrimide agar, respectively. The existence of a phenazine biosynthetic operon and two phenazine modifying genes as well as their protein products were confirmed by PCR and SDS-PAGE, respectively. Pyocyanine was extracted with chloroform and its antimicrobial effects against bacteria such as; Escherichia coli (E. coli), P. aeruginosaand Staphylococcus aureus (S. aureus) bacteria and yeast Candida albicans (C. albicans) were tested using well, spot and disk diffusion methods. Results: In this study, 3 out of 48 clinical strains were unable to produce pyocyanine on cetrimide and Mueller Hinton (MH) agar. Two strains did not have phenazine modifying gene bands. Another strain did not have the possible protein band of the phzM gene. Pyocyanine had antimicrobial effects against the microbial strains, which increased in the presence of silver nanoparticles. Conclusion: According to the results of the present study, some P. aeruginosa strains are unable to produce pyocyanine due to the absence of the phzM or phzS genes. Therefore, these genes have an important role in pyocyanine production in P. aeruginosa. Pyocyanine shows synergistic antimicrobial effects in the presence of silver nanoparticles against microbial strains.

25-30

Authors: Ali Neshasteh-Riz , Fereshteh Koosha , Afshin Mohsenifar , Seyed Rabee Mahdavi

Objective: The passage of ionizing radiation in living cells creates clusters of damaged nucleotides in DNA. In this study, DNA strand breaks induced by the beta particle of iodine-131 (I-131), have been determined experimentally and compared to Monte Carlo simulation results as a theoretical method of determining131I damage. Materials and Methods: In this experimental study, in order to create single strand breaks (SSB) and double strand breaks (DSB) in the DNA, glioblastoma (GBM) cells were exposed to 10 mCi I-131, at a dose of 2 Gy. Damage of irradiated cells were evaluated quantitatively by the Fast Micromethod assay. The energy spectrum of electrons released in cells were obtained by the macroscopic Monte Carlo code (MCNP4c) and used as an input of the micro Monte Carlo code (MCDS). The percent of damage induced in cells was analyzed by Mann-Whitney test. Results: A significant reduction (p<0.05) in fluorescence intensity in irradiated cells compared to control cells as determined by the Fast Micromethod assay represented induced SSB and DSB damages in the DNA of irradiated cells. Comparison of experimental and theoretical results showed that the difference between the percentages of SSB per Gy was about 7.4% and DSB was about 1% per Gy. Conclusion: The differences in experimental and theoretical results may be due to the algorithm of applied codes. Since the Fast Micromethod and other experimental techniques do not provide information about the amount of detailed and complex damages of DNA-like base damages, the applied Monte Carlo codes, due to their capability to predict the amount of detailed damages that occur in the DNA of irradiated cells, can be used in in vitro experiments and radiation protection areas.

39-46

Authors: Sam Zarbakhsh , Mehrdad Bakhtiyari , Abolfazl Faghihi , Mohammad Taghi Joghataei , Mehdi Mehdizadeh , Samideh Khoei , Korosh Mansouri , Behpour Yousefi , Vahid Pirhajati , Fatemeh Moradi , Maryam Shirmohammadi

Objective: Transplantation of bone marrow stromal cells (BMSCs) or Schwann cells (SCs) can facilitate axonal regeneration in peripheral nerve injuries. The aim of this study was to compare the effects of transplantation of BMSCs and SCs on functional recovery after injury to the sciatic nerve in the rat. Materials and Methods:In this experimental research, adult male Wistar rats (n=24, 250-300 g) were used, BMSCs and SCs were cultured, and SCs were confirmed with anti S100 antibody. Rats were randomly divided into 3 groups (n=8 in each group): 1; control group: silicon tube filled with fibrin gel without the cells, 2; BMSCs group: silicon tube filled with fibrin gel seeded with BMSCs and 3; SCs group: silicon tube filled with fibrin gel seeded with SCs. The left sciatic nerve was exposed, a 10 mm segment removed, and a silicone tube interposed into this nerve gap. BMSCs and SCs were separately transplanted into the gap in the two experimental groups and were labeled with anti BrdU and DiI respectively. After 12 weeks electrophysiological and functional assessments were performed and analyzed by one-way analysis of variance (ANOVA). Results: Electrophysiological and functional assessments showed a significant difference between the experimental groups compared with the control group. Electrophysiological measures were significantly better in the SCs transplantation group compared with the BMSCs treatment group (p<0.05). Functional assessments showed no statistically significant difference between the BMSCs and SCs groups (p<0.05). Conclusion: Although both BMSCs and SCs have the potential to produce functional recovery after injury to the sciatic nerve in rats, electrophysiological evaluation confirms that the improvement after SCs transplantation is greater than that after BMSCs transplantation.

53-60

Authors: Fauziah Othman , Gholamreza Motalleb , Sally Lam Tsuey Peng , Asmah Rahmat , Rusliza Basri , Chong Pei Pei

Objective: Breast cancer is the most common cause of cancer-related deaths in women both worldwide and in Malaysia. Azadirachta indica (A. Juss), commonly known as neem, is one of the most versatile medicinal plants that has gained worldwide prominence due to its medicinal properties. However, the anticancer effect of ethanolic neem leaf extract against breast cancer has not been documented. The purpose of the present study is to investigate the effect of neem leaf extract on c-Myc oncogene expression in 4T1 breast cancer BALB/c mice. Materials and Methods: In this experimental study, A total of 48 female BALB/c mice were divided randomly into four groups of 12 mice per group: i.cancer control (CC) treated with 0.5% Tween 20 in PBS, ii. 0.5 μg/mL tamoxifen citrate (CT), iii. 250 mg/kg neem leaf extract (C250), and iv. 500 mg/kg neem leaf extract (C500). In situ reverse transcription polymerase chain reaction (in situ RT-PCR) was applied to evaluate suppression of c-Myc oncogene expression in breast cancer tissue. Results: The C500 group showed significant (p<0.05) suppression of c-Myc oncogene expression compared to the CC group. Conclusion: c-Myc was found to be down regulated under the effect of 500 mg/kg ethanolic neem leaf extract.

67-72

Authors: Azadeh Sayad , Mehrdad Noruzinia , Mahdi Zamani , Mohammad Hossein Harirchian , Anoshirvan Kazemnejad

Objective: Lipid metabolism is involved in the pathogenesis of late-onset Alzheimer’s disease (LOAD). Lipoprotein lipase (LPL) is a multifunctional enzyme that plays a major role in lipid metabolism; its abnormal function seems to be related, either directly or indirectly, to the pathogenesis of many diseases such as atherosclerosis, coronary artery disease (CAD) and Alzheimer’s disease (AD) . HindIII polymorphism is a common LPL genetic variant shown to increase the risk of LOAD. The present research investigates whether this polymorphism is involved in the pathogenesis of Iranian LOAD patients. Materials and Methods: In this case control study ,allele and genotype frequencies for the HindIII polymorphism of the LPL gene in 100 patients affected with LOAD and 100 healthy controls were determined by reaction-restriction fragment length polymorphism (PCR-RFLP) and compared using the chi-square and Fisher’s exact tests. Results: LPL H+H+ genotype frequency in LOAD patients was 58%, which was significantly higher than controls (44%). There was a 1.75-fold increased risk for the development of LOAD in carriers of the H+H+ genotype compared to non-carriers (OR=1.75; 95%CI: 1.00-3.07; p=0.048). When adjusted for sex, the H+H+ genotype was more frequent in patients than controls; this difference was more remarkable in males (OR: 1.90; 95% CI: 1.08–3.34; p=0.024). The mean age of disease onset did not differ in patients with the LPL H+H+ genotype compared to unaffected individuals. Conclusion: This study confirms the association between the H+H+ genotype with LOAD and supports the correlation of this genotype of the LPL gene with risk of developing LOAD in Iranian patients with AD.