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Nasiri N.,Royan Institute for Reproductive Biomedicine | Nasiri N.,University of Tehran | Dizaj A.V.T.,Royan Institute for Reproductive Biomedicine | Ahmadi F.,Royan Institute for Reproductive Biomedicine | And 3 more authors.
Yakhteh | Year: 2010

Objective: Artificial stimulation of mouse oocyte, in the absence of sperm contribution, can induce its parthenogenic activation of oocyte. Ultrasound is one of the newest methods for artificial activation of mammal oocytes, and its successful utilization in pig oocyte activation has been recently reported. Our objective was to assess the effect of ultrasound on mouse oocyte activation. Materials and Methods: Our groups included1 control group, 3 experimental groups consisting of 1, 2 and 3 repetitions of ultrasound exposure, and 3 sham groups handled similar to experimental groups but ultrasound system was off during treatments. In experimental groups, adult female NMRI mice at the interval between pregnant mare serum gonadotropin (PMSG) and human corionic gonadotropin (hCG) injections, were exposed to continuous ultrasound with 3.28 MHz frequency and peak intensity (Ipk) = 355 mW/cm2. Sixteen hours after injection of hCG, the mice were euthanized and their oocytes were collected; thereafter, parthenogenic oocytes were counted. Results: Data analysis using the ANOVA test shows a significant increase in the number of parthenogenic oocytes in mice with 3 overall exposures to ovarian ultrasound (p<0.05). A significant decrease in the number of metaphase II (MII) oocytes numbers was also seen in mice treated with ultrasound (p<0.05). Conclusion: Ultrasound is thought to induce pores generation in oocyte membranes and provides an easier inward transport of Ca++ into oocytes. This phenomenon can induce meiosis resumption in immature oocytes. With increased exposure repetitions from 1 to 3 times and greater Ca++ arrival, oocytes can be parthenogenetically activated. Source

Kashef N.,University of Tehran | Ravaei Sharif Abadi G.,University of Tehran | Djavid G.E.,Iranian Center for Medical Lasers
Photodiagnosis and Photodynamic Therapy | Year: 2012

Background: Photodynamic inactivation (PDI) has been investigated to cope with the increasing incidence of multidrug-resistant (MDR) pathogens. Here we studied the PDI mediated by methylene blue (MB) and toluidine blue O (TBO) in clinical methicillin-resistant Staphylococcus aureus and MDR Escherichia coli, together with their corresponding American Type Culture Collection (ATCC) strains. Methods: Effect of photosensitizer concentration (12.5,25,50. μg/ml) and laser irradiation time (10, 20 and 30. min) on lethal photosensitization was investigated. Results: TBO was more effective. TBO at 50μg/ml, 46.8Jcm -2, exhibited 0.7log killing for MDR E. coli and 1.7log killing for E. coli (ATCC 25922); 3.1log killing for MRSA, and 4.2log killing for S. aureus (ATCC 25923). MB at 50μg/ml, 163.8Jcm -2, only exhibited 2.2log killing in MRSA and 3.1log killing in S. aureus (ATCC 25923). MB (50μg/ml, 163.8Jcm -2) induced 0.2log killing for MDR E. coli and 0.3log killing for E. coli (ATCC 25922). After TBO-PDI, MDR isolates were more susceptible to some antibiotics than control groups. Conclusion: Our studied clinical isolates were more resistant to PDI-mediated killing than their ATCC reference strains. Thus, TBO/MB-mediated PDI in other MDR isolates deserves further investigation. © 2011 Elsevier B.V. Source

Kashef N.,University of Tehran | Ravaei Sharif Abadi G.,University of Tehran | Djavid G.E.,Iranian Center for Medical Lasers
Photodiagnosis and Photodynamic Therapy | Year: 2012

Background: An important determinant of the clinical applicability and value of antimicrobial photodynamic inactivation (PDI) is the cytotoxicity of the treatment to human cells. We evaluated the in vitro cytotoxicity of PDI to primary human fibroblasts using methylene blue (MB) and toluidine blue O (TBO) as the photosensitizers. Methods: The primary human fibroblasts were exposed to PDI regimes that were used for the inactivation of methicillin-resistant Staphylococcus aureus (MRSA) and multi-drug resistant Escherichia coli (MDR E. coli). Mitochondrial activity subsequent to exposure was evaluated after 24. h using the methylthiazoletetrazolium assay and compared to pretreatment values. Results: Mitochondrial activity of primary human fibroblasts was reduced by 27% after exposure to light (163.8J/cm2) and MB (50μg/ml). At a TBO concentration previously demonstrated to induce 99.91% and 83.2% reduction in a viable count for MRSA and MDR E. coli, respectively, 39.6% of the fibroblasts were photo-inactivated. Conclusion: Our findings showed that MB/TBO-PDI did not induce significant cytotoxic effects on human fibroblasts in culture. © 2012 Elsevier B.V. Source

Ataie-Fashtami L.,Iranian Center for Medical Lasers | Shirkavand A.,Iranian Center for Medical Lasers | Shirkavand A.,Tehran University of Medical Sciences | Sarkar S.,Tehran University of Medical Sciences | And 6 more authors.
Photomedicine and Laser Surgery | Year: 2011

Objective: We simulated the heat distribution and thermal damage patterns of diode hair-removal lasers for different spot sizes, pulse durations, and fluences as a guide for optimization. Background: Recently, the concept of thermal damage time as a reference for pulse duration has become a subject of debate. Methods: Laser-Induced-Temperature-Calculation-In-Tissue (LITCIT) was used for the simulations. Skin was modeled as two homogenous layers of epidermis/dermis and two coaxial cylinders as the hair shaft/ follicle. Opto-thermal coefficients of the components and the radiant parameters of the laser (diode, 810 nm) were defined. Results: At constant fluences and pulse durations, the damage occurred deeper when larger spot sizes were used. At constant pulse duration, high fluences caused significant damage to the hair follicle and epidermis. By using longer pulse durations (≤400 ms) at constant fluences, there was more effective damage to the hair follicle while sparing the adjacent epidermis and dermis. Because of the time-dependent temperature profiles, an increased pulse duration creates a moderate, gradual rise in the target's temperature. Pulse durations >400 ms are accompanied by unwanted dermis damage. Conclusions: Our results show that using very long pulse durations near the tissue damage time (≤400 ms) creates better efficacy in treating unwanted hairs while avoiding unwanted damage. © Copyright 2011, Mary Ann Liebert, Inc. 2011. Source

Kashef N.,University of Tehran | Esmaeeli Djavid G.,Iranian Center for Medical Lasers | Siroosy M.,University of Tehran | Taghi Khani A.,University of Tehran | And 2 more authors.
Iranian Journal of Microbiology | Year: 2011

Background and Objectives: Due to the extensive use of antibiotics, the spread of drug-resistant bacteria is one of the most worrisome threats to public health. One strategy that can be used to overcome potential shortcomings might be the inactivation of these organisms by photodynamic therapy. In this study, we have investigated whether drug-resistant wound-associated organisms (Staphylococcus aureus, Staphylococcus epidermidis and Escherichia coli) are sensitive to lethal photosensitization using the dye methylene blue coupled with laser light of 660 nm. Materials and Methods: Effect of photosensitizer concentration (25, 50, 100 μg/ml) and laser light dose (27.3, 54.6 and 109.2 J/cm 2) on lethal photosensitization was investigated. Results: All species were susceptible to killing by photodynamic inactivation. The bactericidal effect was not dependent on the concentration of methylene blue but it was dependent on the light dose. Methylene blue photosensitization using red laser light (109.2 J/cm 2) was able to achieve reductions of 99.03% and 98.95% in the viable counts of S. aureus and S. epidermidis (using starting concentrations of 10 4-10 5 CFU/ml). Eradication of 92.23% were obtained for E. coli (initial concentration 10 4-10 5 CFU/ml) photosensitized by the red light (109.2 J/cm 2). Conclusion: These findings imply that MB in combination with red light may be an effective means of eradicating drug-resistant bacteria from wounds. Source

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