Tehran University Medical Journal

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Background: Recently, bone-marrow-derived cells have introduced new therapeutic approaches to the management of wound healing in severe skin injuries. Bone marrow-derived stromal cells are described as a heterogeneous population, including mesenchymal stem cells, hematopoietic stem cells, and fibro-blast cells. Results derived from several studies indicate that these cells may contribute to tissue regeneration whether through producing variety of bioactive growth factors and/or by differentiation into mesoderm lineage. The aim of the present study was to investigate the effect of subcutaneous administration of bone marrow-derived stromal cells in repairing or regeneration of skin wounds induced by third-degree burn in a mouse model. Methods: In an experimental study that was performed in Urmia University research center from December 2011 to June 2012, The third-degree skin burn was induced on the shaved backs of healthy 7-8 week old male mice (N=18) using a metal rods heated in boiling water. After 1 hour, based on the equal physical condition mice were randomly divided into two separate groups and then subcutaneously administered with phosphate buffered saline (PBS 400 µl) or bone marrow-derived stromal cells (106 cell in 400µl PBS) at the burn site. 7, 14 and 21 days after induction of burn injury, biopsies were taken from burn wounds and then the sections were prepared. Subsequently the prepared sections were stained with hematoxylin/eosin and Masson's trichrome to explore histopathological changes evoke by administration of bone marrow derived stromal cells in comparison with control subjects. Results: Considering investigated parameters including formation of granulation tissue (respectively on days 7, 14 and 21 P≤ 0/007, P≤ 0/0013 and P≤ 0/001), angiogenesis (on day 21 P≤ 0/002) and collagen deposition, in mice treated with bone marrow-derived stromal cells the rate of healing of third-degree thermal burns was significantly accelerated when compared to the PBS-treated mice. Conclusion: This experimental modulation of wound healing suggests that bone marrow-derived stromal cells can significantly enhance the rate of wound healing possibly through stimulation of granulation tissue, angiogenesis, fibroblast proliferation and collagen deposition.

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Embryonic stem cells are pluripotent stem cells which have the ability to indefinitely self-renew and differentiate into all differentiated cells of the body. Regarding their two main properties (unlimited self-renewal and multi-lineage differentiation), these cells have various biomedical applications in basic research and cell based therapy. Because the transplantation of differentiated cells that are derived from embryonic stem cells is allogenic, they face the problem of immune rejection following the transplantation of embryonic stem cell-derived cells into patients. In 2006, researchers from Japan reported the derivation of a new type of pluripotent stem cells which could overcome the problem of immune rejection that is associated with the application of embryonic stem cells. They designated these cells as induced pluripotent stem (iPS) cells, because their production was ‘induced’ from differentiated somatic cells using a combination of four embryonic stem cell-associated transcription factors. Importantly, these pluripotent stem cells exhibit all the key features of embryonic stem cells including unlimited self-renewal and multi-lineage differentiation potential, and can pass the most stringent test of pluripotency which is known as the tetraploid (4n) complementation. Hence, in addition to bypassing the problem of immune rejection, iPS cells have all of the potential applications of embryonic stem cells, including in developmental studies, toxicology research, drug discovery and disease modeling. Also, considering that they could be generated from patient’s own cells, iPS cells hold great promise in the future of patient-specific cell replacement therapies using pluripotent stem cells. In this review article, we will present a comprehensive review on the how and why of the generation of iPS cell from somatic cells of the body and discuss how they should be characterized in terms of morphologically, pluripotent stem cell behavior, and the molecular signature. In addition, their medical applications as well as some of the considerations and future challenges in their use will be discussed.

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Background: About 15% of couples have fertility problems and male factor in fertility accounts for half of the cases. In vitro generation of germ cells introduces a novel approach to male infertility and provides an effective system in gene tracking studies, however many aspects of this process have remained unclear. We aimed to promote mouse embryonic stem cells (mESCs) differentiation into germ cells and evaluate its effectiveness with tracking the expression of the Testis specific 10 (Tsga10) during this process. Methods: This is an in vitro study that was performed in department of Medical Genetics in Tehran University of Medical Sciences from February 2012 to March 2013. Mouse embryonic stem cells were cultured on mouse embryonic fibroblast as feeder layer. Then mESCs were differentiated into germ cells in the presence of Retinoic Acid. Based on developmental schedule of the postnatal testis, samples were taken on the 7th, 12th and 25th days of the culture and were subjected to expression analysis of a panel of germ cell specific genes (Stra8 as pre-meiotic, Dazl and Sycp3‌ as meiotic and Protamin1 and Spata19 as Post-meiotic). Expression of Testis Specific Gene 10 (Tsga10) at RNA and protein levels was then analyzed. Results: It was shown that transition of embryonic stem cells from mitosis to meiosis occurred between 7th and 12th days of mESC culture and post-meiotic gene expression did not occur until 25th day of the culture. Results showed low level of Tsga10 expression in undifferentiated stem cells. During transition from meiotic to post-meiotic phase, Tsga10 expression increased in 6.6 folds. This finding is in concordance with in vivo changes during transition from pre-pubertal to pubertal stage. Localization of processed and unprocessed form of the related protein was similar to those in vivo as well. Conclusion: Expression pattern of Tsga10, as a gene with critical function in spermatogenesis, is similar during in vitro and in vivo germ cell generation. The results suggest that in vitro derived germ cells could be a trusted model to study genes behavior during spermatogenesis.

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Background: Hematopoietic stem cell transplantation (HSCT) is a therapeutic approach in treatment of hematologic malignancies and incompatibility of bone marrow. Umbilical cord blood (UCB) known as an alternative for hematopoietic stem/ progenitor cells (HPSC) for in allogenic transplantation. The main hindrance in application of HPSC derived from umbilical cord blood is the low volume of collected samples. So, ex vivo expansion of HPSCs is the useful approach to overcome this restriction. Synthetic biomaterials such as nanofibers is used to produce synthetic niches. The aim of this study was the ex vivo expansion of hematopoietic stem cells on biocompatible nanofiber scaffolds. Methods: This study was done at Tarbiat Modares University from November 2012 to June 2013 and was a research study. Umbilical cord blood CD133+ hematopoietic stem cells were separated using MidiMacs (positive selection) system by means of monocolonal antibody (microbeads) CD133. Flow cytometry was used to assess the purity of cells. Cell culture was done on plate (2 Dimensional) and fibronectin conjougated polyether sulfone nanofiber scaffold (3 Dimensional). Colony assay test was used to asses the ability of colonization of cells. Results: Cell count analysis revealed the expansion of hematopoietic stem cells in cell culture plate (2D environment) and on nanofiber scaffold (3D environment) after 2 weeks. Expansion of cells in 2D environment was greater than 3D condition. Colony assay test revealed that the colonization ability of cells decreased after 2 weeks, but this decrease was lower in scaffold culture than plate culture. Conclusion: This study demonstrated that umbilical cord blood CD133+ hematopoietic stem cells can expand on fibronectin conjugated polyether sulfone scaffold and we can use this system for expanding of cells in vitro situation.

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Background: Mycoplasma contamination in cell cultures is considered as a major economic, research and production problem. In this study, mycoplasma-infected Vero cell lines were treated by various dilutions of ciprofloxacin and enrofloxacin in a timely manner. Removal of mycoplasma contamination from infected cell cultures was evaluated and demonstrated by polymerase chain reaction (PCR) method. Methods: This study was done from October 2013 to May 2014, in Human Rabies Vaccine Laboratory, Pasteur Institute Production and Research Complex, Tehran, Iran. Different dilutions of ciprofloxacin and enrofloxacin were used in sequential passages for treatment of infected Vero cell line. Based on lowest passages of the cell line, antibiotic treatment with ciprofloxacin and enrofloxacin was done. Amelioration of the infection and removal of mycoplasma contamination was confirmed in each step by PCR method. The technique for order of preference by similarity to ideal solution, TOPSIS method, was used to suggest the most efficient concentration of ciprofloxacin and enrofloxacin. Results: Proposed concentration of ciprofloxacin is 20 μg/ml, and in the second order is 200 μg/ml. For enrofloxacin the best proposed concentrations are 30, 300 and 3 μg/ml respectively. Ciprofloxacin and enrofloxacin and ability of them for removal of mycoplasma and also the time of treatment were verified by evaluation of the recurrence of infection through consecutive subcultures of the treated cell line. Conclusion: Our results showed that 20 μg/ml of ciprofloxacin was the dilution of choice for mycoplasma elimination followed by 200 μg/ml of ciprofloxacin. Concentrations of 3, 30 and 300 of enrofloxacin, respectively, are appropriate for mycoplasma removal. More detailed works would be needed to verify the authenticity of the proposed simple and affordable way of mycoplasma elimination.

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Background: Pregnancy is a phenomenon that antigens of semi allogenic fetus are in direct contact with mother's immune system. Immune dysregulation can cause fetus rejection by mother's immune system responses. Human leukocyte antigen-G1, as an immunotolerant molecule has a major role to induce tolerance during pregnancy by suppression of natural killer cells through inhibitor receptors on these cells. Natural killer cells have an important role in immune surveillance and these cells can be reaction with HLA-G molecules on the trophoblast cells surface. This function prevents natural killer cell invasion against fetus trophoblast cells. The purpose of this study was determination of natural killer cells percent and human leukocyte antigen-G1 expression in peripheral blood of threatened-abortion pregnant women in comparison with control group. Methods: This case-control study was conducted from, February 2014 to October, 2014 in Baghban Clinic in Sari City, Mazandaran province. We investigated 21 threatened-abortion women with light bleeding or spotting less than twenty weeks of pregnancy in comparison with 21 normal pregnant women as control group. Peripheral blood mononuclear cell was isolated by ficoll histopaque (1.077) and natural killer cells percent were evaluated by flow cytometry. Furthermore, we assessed the human leukocyte antigen-G1 isoforms expression by real-time polymerase chain reaction (PCR) in case and control groups. Results: The results of this study was shown that natural killer cells percent in threatened-abortion pregnant women was significantly higher than normal pregnant women (P=0.03). In addition, human leukocyte antigen-G1 isoform had a lower expression in threatened-abortion pregnant women in comparison with control group (P=0.004). Conclusion: Decreasing of human leukocyte antigen-G1 expression with increasing of natural killer cells level in threatened-abortion pregnant women is an indicator of mother's immune system dysregulation in comparison with control group. Therefore, it is concluded that in the threatened-abortion pregnant women, human leukocyte antigen-G1 expression level with natural killer cells percent as diagnostic marker must be determine.

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Background: Stem cells represent an ideal cell source for application in tissue engineering and regenerative medicine due to their ability to proliferate and differentiate to a wide variety of cell lineages. With recent development of medical sciences and tissue engineering, usage of adipose-derived mesenchymal stem cells, their culture and differentiation on suitable scaffolds are considered as a successful clinical and research strategy. One of the most crucial factors in a successful tissue engineering technique is to choose an appropriate scaffold which allow cell migration transferring of bioactive factors as well as providing optimal growth environment for stem cells. In this study, the ability of two scaffolds is investigated as a suitable environment for the proliferation and differentiation of adipose-derived mesenchymal stem cells. Methods: This is an in vitro study that was performed in Laboratory of Stem Cell in Academic Center for Education, Culture and Research, Qom province from April 2013 to February 2014. In this study, two scaffolds including fibrin glue and alginate were prepared as two separate groups and after isolating mesenchymal stem cells from adipose tissue and adequate proliferation, they were seeded into each scaffold in chondrogenic medium. After 14 days, the evaluation of viability and gene expression of collagen II and I, SOX9 and aggrecan were done by MTT (3-{4,5-dimethylthiazol-2yl}-2,5-diphenyl-2H tetrazolium bromide) assay and real-time PCR technique respectively. Also, cartilaginous tissue formation on scaffolds was evaluated by histological analysis. Results: According to the obtained results, the fibrin glue scaffold showed significant difference in terms of viability in comparison to alginate scaffold in chondrocyte differentiating medium (P< 0.05). Also the results of real-time PCR analysis showed that the fibrin glue scaffold express cartilage specific genes at a higher level than alginate scaffold. Conclusion: The use of natural fibrin glue scaffold can be considered as a suitable environment for proliferation and differentiation of adipose-derived mesenchymal stem cells in cartilage tissue engineering.

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Background: In this study were focused on corneal cells changes in keratoconus disease, as there are differences between results of other studies that were done on keratokonic eyes. And the chief purpose was a comparison between keratoconus and normal population based corneal endothelium (in cell density, pleomorphism and polymegethism of cells). Methods: This study is an observational study and is a case-control type. This study was done in Farabi Ophthalmology Hospital, Tehran, from September 2013 to February 2014. In this study, 26 mild (corneal power is lower than 48 diopter) and moderate (corneal power is between 48 to 54 diopter) keratoconic eyes (case group) with no history of contact lenses wear or eye surgeries were compared with 25 normal eyes (control group) that corneal power based topographic images is lower than 47.2 diopter. This comparison were done based specular microscopy images which were taken by Noncontact (Topcan Sp-2000 P) specular microscope in 5 corneal regions (central, superior, inferior, nasal, temporal). Then the information related to the cell density, Coefficient of Variation (CV) of polymegethism and pleomorphism of cells were analyzed by SPSS software, version 21 (SPSS, Inc., Chicago, IL, USA). Results: Superior corneal region has the largest amount of endothelial cell density in case and control groups (P<0.001). But the effects of keratoconus on the cell density was not significant (P=0.96). And also CV of polymegethism in two groups (case and control groups), was similar (P=0.828). Pleomorphism was seen in 7 eyes of 26 eyes in case group (26.9%) and 6 eyes of 25 eyes in control group (24%). Conclusion: Keratoconus does not have any considerable effect on cell density, polymegethism and pleomorphism, in mild and moderate stages and corneal opacity risk caused by intraocular surgeries (such as: Cataract or Glaucoma surgeries) and some diseases (such as diabetes and uveitis) is similar in keratoconic and normal eyes.

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Fibronectin (FN) is one of the essential component of the extra cellular matrix and their important role is as regulator of cellular activities and also fibronectin is an important scaffold for maintaining tissue. Fibronectin conformational changes expose additional binding sites that participate in fibril formation and in conversion of fibrils into a stabilized, insoluble form. In fact fibronectin is a connected glycoprotein disulfide dimer with sedimentation coefficient of approximately S 13 and 440 kDa molecular mass which is exist in many extracellular matrix and plasma with concentration of approximately 300 µg/ml that during the regeneration body tissues acts in severely regulated stages until regenerate the damaged tissue. Fibronectin has domains for interacting with other extra cellular matrix proteins, cell surface receptors, glycosaminoglycans (GAGs), and other FN molecules. This combination of domains allows FNs to bind simultaneously to cells and to molecules within the surrounding matrix. Also fibronectin have binding sites for collagen/ gelatin, heparin, fibrinogen, and other molecules. In the present study important roles of fibronectin in development, regeneration especially in nerves system and important role of it in treatment of some diseases have been reviewed. Present study has reviewed 77 publications by using of PubMed, NCBI, Elsevier, EBSCO and Nature databases for describing the important roles of fibronectin in biological systems. Studies have shown that fibronectin has diverse roles such as: cellular adhesion, embryonic differentiation, assembly of extra cellular matrix, connecting and cell growth, transformation as well as cell migration that each of this roles depends to fibronectins action site. Considering the important role of fibronectin in attachment of cancer cells to basal lamina, spread neoplasm, tissue regeneration and formation of extra cellular matrix better identification the properties as well as physiological applications of fibronectin in tissues and bodies of animals can provide the better understanding of physiological mechanisms and pathophysiological effects of cells on each other, and also provides the new ways for treatment a variety of diseases.

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Background: Allergic Asthma is an inflammatory disease of the respiratory system that is well known by increased inflammatory cells in the airways and causes difficulty in respiration. The prevalence of allergic asthma is increasing worldwide, and it has become a significant cause of health challenge especially in developed countries. Inhaled β2-agonists and Inhaled or oral corticosteroids are common medications for treating the disease, but they cannot be used for long periods of time because of frequently occurring side effects and they can’t change the main pathogenesis of the problem. Deficiency in regulatory system against inflammation could be an important factor in allergic asthma. Mesenchymal stem cells (MSCs) have potential of cellular immunosuppressive therapy of inflammatory disorders. The aim of present study was to evaluate the effects of MSC therapy on mechanisms of allergic asthma in mice model. Methods: This experimental study was conducted from August 2014 to March 2015. The animals were housed and maintained in Biotechnology Center of Urmia University, Iran. Mice were sensitized by intra-peritoneal injection of ovalbumin (OVA) and aluminum hydroxide emulsion and then were challenged intra-nasally with OVA. Before allergen challenge on day 14, experimental mice received tail vein injection of MSCs in PBS. Regulatory T cells of spleen, cytokines and IgE analysis were carried out using lungs wash as well as serum samples. Results: Our results showed that MSCs significantly reduced total cells and eosinophilia, serum OVA-specific IgE concentration in OVA-sensitized and challenged mice. Also results showed that MSCs markedly inhibited expressions of Th2 cytokines and elevated levels of Treg cells and Treg cytokines. Conclusion: In the present study, we demonstrated the inhibitory effect of MSCs on airway inflammation using mice model of allergic asthma. The mice were sensitized with OVA and compared to the results of dexamethasone administration. Our results demonstrated that administration of MSCs could be used as a potential therapeutic approach for the allergic asthma.

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Background: After primary infection, the number of CD4 T-cells decreases with disease progress. The patient’s immunological status could inform by The CD4 T-cell counts over the time. The main purpose of this study is to assess the trend of CD4 cell count in HIV+ patient that received Antiretroviral Therapy (ART) by using a multistate Markov model to estimate transition intensities and transition probabilities among various states.

Methods: A total of 122 HIV+ patients were included in this cohort study who are undergoing Antiretroviral Therapy treatment in the Iran AIDS center in Imam Khomeini Hospital in Tehran that inter during March 1995 to January 2005 and then fallow up to October 2014. All adults with at least two follow-up visits in addition to their pre-ART treatment were considered to be eligible for inclusion in the study. Continuous-time Markov processes are used to describe the evolution of a disease over different states. The mean sojourn time for each state was estimated by multi state Markov model.

Results: Sample included 22 (18%) female with a mean age of 43.32 (standard deviation 8.33) years and 100 (82%) male with a mean age of 45.28 (standard deviation 8.34) year. Age was divided in to two categories, 40 years old and lower than that 66 (54.1) patents and persons older than 40 years old 56 (45.9) patents. A total of 122 patients were included. 29 patients died during follow-up. One year transition probability for staying in state 1 of CD4 cell count was 51%. This probability for six year was 33%. The mean sojourn time for sate 4 was 21 month. The hazard ratio of transition from state 3 to state 4 was 4.4 in men related to women.

Conclusion: The use of antiretroviral therapy in the treatment of HIV infected persons reduce viral replication and increase in CD4 T lymphocyte count, and delay the progression of disease. This paper is shown the progression of this trend.

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Background: Spermatogenesis is a complex and highly organized process of proliferation and differentiation of spermatogonial stem cells. Spermatogonial stem cells (SSCs) as a unique stem cell have the potential to self-renewal, differentiation and transmit genetic information to the next generation and play a vital role in maintaining fertility. Sertoli cells as the only somatic cells within the seminiferous epithelium play central roles in the formation of niche and balance between self-renewal and differentiation by secrete many growth factors. Given the importance and widespread use of SSCs, particularly in the treatment of infertility, the aim of this study was to create an optimal environment for the proliferation of SSCs. So we decided to study of undifferentiated (ID4) and differentiated (c-Kit) gene expression in SSCs followed by co-culture with Sertoli cells for a one-month.

Methods: This experimental study was conducted from November 2013 to December 2014 in Department of Anatomy, School of Medicine, Tehran University of Medical Sciences, on immature NMRI mouse (6-3 days old). Initially, Sertoli cells and SSCs were isolated from neonates mouse testes during the two-step enzymatic digestion characteristics Sertoli cells with vimentin marker and SSCs with promyelocytic leukemia zinc-finger (PLZF) marker were confirmed. Then SSCs were cultured in two groups: co-culture with Sertoli and without co-culture (control). Undifferentiated (ID4) and differentiation (c-Kit) gene expression were evaluated by Real-time PCR technique.

Results: Spermatogonial stem cells purity was obtained 66.91% by flow cytometry. The relative expression levels of gene ID4 in co-culture group at the end of each week, compared to the control group showed a significant increase (P<0.05). While the expression of this gene significantly decreased in each group over time (P<0.05). The results of the comparison of the relative expression of c-Kit gene in co-culture group are indicated significant decrease than the control group at the end of each week (P<0.05). In addition, this gene expression was showed significant increase in each group individually over time (P<0.05) ID4 gene expression showed a significant (P<0.05) increase toward the control group, while in the expression of c-Kit was observed a significant (P<0.05) decrease compared with the control group at the end of each week.

Conclusion: According to the results of this study, co-culture with Sertoli cells maintains SSCs in the prolifration stage for long-term, so can be used to optimize the culture medium at the clinic.

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Stem cells are undifferentiated and multi pluripotent cells which can differentiate into a variety of mature cells and tissues such as nervous tissue, muscle tissue, epithelial tissue, skeletal tissue and etc. Stem cells from all different source have three unique features: 1) Proliferative capability: Stem cells are capable of self dividing and self renewing for long periods or more than six months at least that called immortalization. 2) Undifferentiated nature: It’s considered as one of the essential characteristics of stem cell, so it doesn't have any tissue-specific construction. 3) Differentiation to the different cells from all organs: This ability can Induced by tissue specific transcription factors. Because of that, they are so important in prevention and treatment of human disease. Depending on the sources from which they derive, they have different types which can be used to produce special cells and tissues. The most significant types of stem cells are; embryonic stem cells (ESCs) which are derived from embryos, adult stem cells (ASCs) which are derived from differentiated cells in a specific tissue, induced pluripotent stem cells (iPSs) which are produced from adult differentiated cells that have been genetically reprogrammed to act resemble to an embryonic stem cell and cord blood stem cells which contains haematopoietic stem cells and derived from the umbilical cord after gestation. By providing a medium containing of special growth factor, it is possible to orientated stem cell differentiation pathway and gained certain cells from them. The important uses of stem cells includes damaged heart tissue cells improvements and bone tissue repairing, cancer treatment, damaged neurological and spinal tissue repairing, improving burns and injuries and the treatment of diabetes, infertility and spermatogenesis dysfunction. Furthermore, the application of them in gene therapy is an important issue in the modern medicine science due to the role of them in transferring gene into different cells. Today, this method have had considerable progress in the treatment of many disease. In this review study, some aspect of stem cells like types and characteristic, origin, derivation techniques, storage conditions and differentiation to target tissues, current clinical usage and their therapeutic capabilities will be discussed.

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It was assumed that the loss of cardiomyocytes is irreversible. The main goal is to develop widely available and clinically applicable treatments for heart diseases. The several studies have showed that the use of stem cells can improve complicacies such as cardiovascular diseases. Stem cells have a potential benefit of the self-renewal and cell differentiation into the cell types that can play an important role in the organogenesis and the embryonic development. In a lifetime, the heart muscle has a population of cardiac stem cells (CSCs) in which a dramatically increase after cardiovascular damages. So far, seven types of CSCs have been discovered with the different molecular phenotype and the cell differentiation potential. In this regard, the proliferation and the differentiation increase of CSCs in the cardiac ischemic areas can be a key factor to improve heart complicacies. Paracrine and/or autocrine factors, the extracellular matrix and the genetic mediators including microRNA can control the function of CSCs. It has clearly been understood that the factors mentioned previously have the ability to improve these complicacies. The differentiation, the survival and the self-renewal of CSCs are largely under the control of factors in the heart microenvironment. Several studies showed that the cytokines and the growth factors play the important role in the proliferation and the migration of CSCs. Taking advantage of these factors together CSCs to repair damaged heart can enhance this method efficiency. This review will discuss the different kinds of CSCs, their molecular phenotype and cardiac regeneration potential in order to improve cardiovascular diseases. It seems that CSCs-based therapy is emerging as a novel approach for myocardial repair over conventional cardiovascular therapies. Therefore, understanding the new aspects on the molecular mechanisms and the signaling pathways involving CSCs is critical for the development of the therapeutic strategies in cardiac patients that would be valuable for researchers in both fields of molecular and clinical cardiology.

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Background: Hydroxyapatite nanoparticles have a more surface contact and solubility than conventional hydroxyapatite. Hydroxynanoparticles enhances the biological and mechanical properties of new regenerated tissues. The hydroxyapatite nanoparticles have received attention as a new and effective osseous graft for using as scaffolds in bone regeneration. The reports on hydroxyapatite nanoparticles biocompatibility are controversial. It has been shown that hydroxyapatite nanoparticles induces inflammatory reaction and apoptosis. The aim of the present study was to evaluate the cytotoxicity of nano-hydroxyapatite on the human epithelial cells.

Methods: The study was experimental and completed in vitro. The study was carried out in department of Immonulogy, Faculty of Medicine, Shahid Beheshti University of Medical Sciences in November 2014. The human-derived oral epithelium cell line (KB) obtained from Pasteur Institute, Tehran, Iran were exposed to hydroxyapatite nanoparticles at 0.01, 0.05, 0.1, 0.5, 0.75, 1, 2.5 and 5 mg/ml concentrations in 24, 48 and 72 hours. Rod-shaped hydroxyapatite nanoparticles with 99% purity and maximum 100 nm sized particles were used. Methylthiazol tetrazolium bromide (MTT) method was employed for cell vitality evaluation. Enzyme-linked immunosorbent assay (ELISA) was used for assessing the viability of cells. Distilled water and fetal bovine serum (FBS) were positive and negative controls. ANOVA and Duncan tests were used for statistical analysis.

Results: The cytotoxicity of different concentrations of hydroxyapatite nanoparticles on human-derived oral epithelium cell line in 24 (P< 0.001), 48 (P< 0.001) and 72 hours (P< 0.001) was significantly different. The nano-hydroxyapatite particles at 0.5 to 1 mg/ml had the highest cytotoxicity effect on human-derived oral epithelium cells in 24, 48 and 72 hours. Lower concentrations than 0.05 mg/ml had the best biocompatibility properties in 24, 48 and 72 hours.

Conclusion: Hydroxyapatite nanoparticles had a good biocompatibility. The biocompatibility of hydroxyapatite nanoparticles were dose and time dependent. The lower concentrations than 0.05 mg/ml of nano-hydroxyapatite had the best biocompatibility over time.

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Background: Telomerase as an enzyme with reverse transcriptase activity has an essential role in telomere maintenance by adding a telomere repeat sequence to the 3' end of chromosome and is important for regulating of many processes in embryonic development including cell proliferation and differentiation. Human umbilical cord-derived mesenchymal stem cells (hUC-MSCs) with a self-renewal capacity are cells that can differentiate into various germ layer derivatives including neural cells and cardiomyocytes, and undergo biological changes during long-term cultivation. Hence, the passage number in which the cells expanded seems to be very important for proliferating and differentiating. This study was aimed at investigating the relationship between the telomerase activity and the growth rate of (hUC-MSCs) at different passages.

Methods: This experimental study was performed in Ardabil University of Medical Sciences, Iran, from March 2014 to December 2014. The umbilical cord samples were obtained from full-term neonate hospitalized in Alavi’s Hospital in Ardabil under sterile conditions. The umbilical vessels were clear off and the small pieces of the umbilical cord were cultured in Dulbecco's modified eagle's medium (DMEM) supplemented with 20% fetal bovine serum (FBS). Then, the hUC-MSCs were harvested from passage one to three to calculate the population doubling time (PDT) and extract proteins by using CHAPS lysis buffer. Finally, the telomerase activity of the cells at different passages was measured by telomeric repeat amplification protocol (TRAP) and qRT-TRAP assays.

Results: The hUC-MSCs population doubling time at passage from 1 to 3 were calculated as the average of 54.68±1.92, 55.03±1.71 and 69.41±2.54 hours, respectively, suggesting the higher cell passage number, the more extended PDT. The threshold cycles (CTs) for the telomerase activity also showed 30.58±0.51, 27.24±0.74 and 32.13±0.75 for the cell passage from one to three, respectively, representing the significant increasing in telomerase activity at passage two compared with the other passages (P= 0.021).

Conclusion: Analysis of the growth curve, PDT determination and measurement of telomerase activity of the human umbilical cord-derived mesenchymal stem cells showed that the long-term cell culture can affect on the cell proliferation and the telomerase activity.

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Background: Operation theatre in a hospital requires considerable human and physical resources to deliver surgery services on an agreed schedule. However, operation theatres are sometimes underutilized due to avoidable last minute cancellations of operations. Cancellation of operations on the day of intended surgery results in operation theatre planning difficulties, hospital inefficiency and resource wastage. In addition, it causes stress for patients and their relatives and results in unnecessary hospital staying. Cancellation of planned operations could be avoided by applying appropriate management strategies and techniques. Quality management as an organizational strategy helps enhance hospital departments’ productivity.

Methods: This study aimed to reduce cancelled surgeries in Shahid Rajaei Hospital in Tehran using a quality management model. A participatory action research was used for the intervention between April 2013 and March 2014. Information on operations cancelled on the day of surgery obtained each day from the operating theatre list. Using a checklist, the reasons for operations cancellation were identified, investigated and an action plan was developed for its reduction. The plan was implemented using the action research cycle.

Results: The number of surgeries increased by 4.06 percent and operations cancellation was reduced by 32.4 percent using the quality management strategy. Surgeon and anesthetist related factors, over-running of previous surgery, changes in patient clinical status and lack of intensive care unit beds were the main reasons for cancelling surgeries. Standardization of processes, proper planning and using anesthetics clinic helped reduce the operations cancellation.

Conclusion: Last minute surgeries cancellation is potentially avoidable. Implementing an appropriate quality management model helps enhance hospital departments’ productivity and reduce surgical cancellation.

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Background: In recent years the use of diced cartilage grafts in reconstructive surgery particulary rhinoplasty have been considered by most plastic surgeons. However, long-term resorption usually occurs. Stem cells are a powerful tool for reconstructive surgery to rebuild and maintain tissue with reduced complications. Since the adipose tissue-derived stem cells (ADSCs) can rebuild a wide variety of tissues such as skin, fat, bone and cartilage are used, this is a very good chance for cosmetic surgery. The aim of this study was to examine the effects of adipose-derived stem cells on the viability of diced cartilage grafts.

Methods: This interventional study was performed on May 2014 in animal laboratory of Hazrat Fatima Hospital on 10 New Zealand white male rabbits, weighing 2000-2500 grams, approximately 12 to 16 weeks of age. Stem cells was harvested from inguinal adipose tissue of each rabbits. After completely removing the skin and perichondrium, cartilage became divided into two equal pieces using a scalpel. Then place the ear amputation was restored by nylon 4 zero. After weighing cartilages, on either side of the center line on the back of each rabbits, left and right, subcutaneous pocket created equal weight and each piece of cartilage was placed in an envelope. Stem cells were injected in one side and the other side was control. The cartilage weights were recorded both before implantation and after explantation. Evaluation of living chondrocytes was conducted 12 weeks after implantation.

Results: The mean difference of cartilage weights was varied between two groups (intervention and control sides), So that the average was significantly higher in stem cell side than that in the control side (P= 0.021). The average number of live chondrocytes was significantly higher in the intervention side than the control side (P< 0.001).

Conclusion: Despite the unclear mechanism, these results suggest that adipose-derived stem cells can maintain the viability of diced cartilage. Because adipose-derived stem cells are autologous and easy to harvest, they can be use to improve the long-term outcomes of diced cartilage grafting.

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Background: Human brucellosis is a significant public health problem in many middle east countries including Iran. Brucella organisms, which are small aerobic, facultative intracellular coccobacilli, localize in the reproductive organs of host animals, causing abortions and sterility. They are shed in large numbers in the animal’s urine, milk, placental fluid, and other fluids. Dairy product from raw milk are a potential threat to public health in endemic developing countries. The gold standard for the diagnosis of brucellosis is isolation of Brucella species. However, isolation Brucella species is time consuming and needed to level 3 biocontainment facilities and highly skilled technical personnel to handle samples and live bacteria for eventual identification. Handling Brucella species increase risk of laboratory infection. Polymerase chain reaction (PCR) with high sensitivity and specifity overcomed to these disadvantages. The aim of this study was to detect Brucella species in milk from dairy cattle farms in Kerman province, Iran by PCR technique.

Methods: Forty and eight bulk tank milk (BTM) were collected from October 2015 to March 2016 from 48 dairy cattle farm including 4200 cows. DNA of milk samples extracted by lysis buffer and proteinase K method. All milk samples were examined by PCR to detect Brucella-specific DNA targeting IS 711. Positive samples must be showed 317 bp amplified, corresponding to the expected size of the IS 711 genome region in all Brucella species.

Results: Using IS711 primer were detected in 4 samples (8.3%) Brucella spp. from 48 BTM samples in this area.

Conclusion: The results indicate that brucellosis by Brucella species is endemic in the Kerman province dairy farms. Consumption of raw milk dairy products by individual farmers operating under poor hygienic conditions represents an high risk to public health. The need for implementing control measures and raising public awareness on zoonotic transmission of brucellosis are recommended. Vaccination of cattle is recommended for control of bovine brucellosis in enzootic areas with high prevalence rates.

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Background: Breast cancer is a malignant proliferation of epithelial cells that lining the ducts or lobules of the breast. It is the second common cancer, after lung cancer in women. Since growth inhibition is an important strategy in cancer treatment, many attempts are in program to find new apoptotic inducer agents. Today there is some reports about effect of metabolites of Pseudomonas on cancer cells, hence, metabolites of Pseudomonas sp. UW4, were isolated and anti-cancer and anti-microbial activity of these metabolites was studied. Methods: This experimental study was performed in cellular and developmental biology of Shahrekord Islamic Azad University from April 2015 to August 2015. Anti-microbial activity of metabolites of Pseudomonas sp. UW4 was tested against a pathogenic bacteria, including Escherichia coli, Bacillus cereus and Staphylococcus aureus. For anti-cancer activity, in this study SKBR3 cells and normal fibroblast cells (HU-02) were cultured in DMEM medium with 10% fetal bovine serum (FBS). The cells were treated by various concentrations of these metabolites 5, 10, 15 and 20 mg/ml for 24, 48 and 72 h. Cell viability was assessed by MTS assay. Cells were seeded at 5×103 cells/ml in 96 well plates and incubated for 24 hr. Then metabolites of bacteria were added, after indicated times MTS (20 µl) was added and the absorbance was measured at 492 nm using ELISA plate reader. Results: Pseudomonas sp. UW4 was able to produce antimicrobial metabolites against Staphylococcus aureus. Metabolites decreases the viability of SKBR3 cell line in a time and dose dependent manner, so that the most effective concentration of this substance was 20 mg/ml and 72 h after treatment (P< 0.01). While Pseudomonas sp. UW4 in various concentrations had no significant effect on normal fibroblast cells (P= 0.24). Conclusion: Bioactive compounds produced by of Pseudomonas sp. UW4 could be used for elimination of infections and treatment of breast cancer SK-BR3.