Counterflow Combustion of Micro Organic Particles

The structure of counterflow premixed flames in an axisymmetric configuration, containing uniformly distributed volatile fuel particles, with nonunity Lewis number of the fuel are examined. It is presumed that the gaseous fuel, produced from vaporization of the fuel particles, oxidizes in the gas phase and the fuel particles do not participate in the reaction. The analysis is carried out in the asymptotic limit for large values of Zeldovich number.A one-step reaction is assumed. The flame position is determined andthe effect of Lewis number change on fraction distribution is investigated

Inhibition of cell proliferation and increased-apoptosis of AGS and SNU-5 cancer cells following small interfering RNA (siRNA)-mediated down-regulation of vascular endothelial growth factor receptor 1 (VEGFR1)

BACKGROUND: Angiogenesis is vital for development of normal tissue and wound healing; but it play an important role in development of some diseases such as different types of cancer. Vascular endothelial growth factor (VEGF) and VEGF receptors (VEGFR) are two important key factors in this process. Previous studies have shown that down-regulation of VEGFR1 inhibits cell proliferation, migration, and vascular permeability of endothelial cells. So, blocking VEGF and VEGFR1 have been considered as a target to prevent the growth of tumors.METHODS: In this study, VEGFR1 gene expression was suppressed in AGS and SNU5 cancer cells using RNA interference (RNAi) technology. Down-regulation of VEGFR1 was assessed at mRNA and protein levels using real-time polymerase chain reaction (PCR), and western blot methods. Moreover, the viability and apoptosis of these cells were analyzed using MTT and flow cytometry techniques.RESULTS: VEGFR1 expression was significantly down-regulated both in mRNA and protein levels. MTT and flow cytometry results revealed that down-regulation of VEGFR1 inhibited cell proliferation, and induced apoptosis of these cancer cells.CONCLUSION: Our findings suggest that VEGFR1 could play an important role in cell proliferation and tumor growth; and it could be considered as a valuable target for controlling tumor cells, and cancer therapies

In vivo reprogramming: A new approach for tissue repair in chronic diseases

Medical researchers and biologists have long been fascinated by the possibility of changing the identity of cells, a phenomenon known as cellular plasticity. Now, we know that differentiated cells can be experimentally coaxed to become pluripotent (cellular reprogramming). Recent studies have demonstrated that changes in cell identity are not limited to the laboratory, but also the tissue cells in live organisms are subjected to this process, too (endogenous cellular reprograming). Nowadays “reprogramming technology” has created new opportunities in understanding human chronic diseases, drug discovery, and regenerative medicine. This technology have enabled the generation of various specific cell types including cardiomyocytes, pancreatic beta cell, and neurons, from patient’s cells such as skin fibroblasts. Reprogramming technology provides a novel cell source for autologous cell transplantation. But, cell transplantation faces several difficult hurdles such as cell production and purification, long-term survival, and functional integration after transplantation. Recently, in vivo reprogramming, which uses endogenous cells for tissue repair, has emerged as a new approach to circumvent cell transplantation. Up till now, in vivo reprogramming has been practiced in the mouse pancreas, heart, brain, and spinal cord with various degrees of success. In this review, we summarize the progress made, therapeutic potentials, and the challenges ahead in this emerging research area

The Effect of Photodynamic Therapy in the Treatment of Chronic Periodontitis: A Review of Literature

Introduction: Chronic periodontitis is the most common periodontal disease which is related to the chronic accumulation of bacterial plaque. Since mechanical methods are not sufficient in the treatment of this disease, administration of local/systemic antibiotic is recommended following mechanical debridement. However, side effects of antibiotics such as microbial resistance and patient allergy led to development of alternative methods. One of these suggested methods is the antimicrobial photodynamic therapy (aPDT). PDT is a local noninvasive treatment modality without the side effects caused by antibiotics. The aim of this study was to review the articles related to the application of PDT with laser in the treatment of chronic periodontitis.Review of literature: In the present review of literature, the authors used key words such as Chronic Periodontitis, Laser and Photodynamic therapy, and conducted a literature search via Google Scholar and PubMed for the period of 1990 to 2015. A total of 47 articles in English were found. The articles that were not associated with the topic of research and review articles were deleted and only clinical trials were evaluated. After reviewing 23 articles’ abstracts, the full texts of 16 articles were analyzed.Conclusion: Considering the safety, the lack of side effects and general advantages like more patient compliance, the PDT treatment with SRP is recommended as an efficient adjunctive modality for the treatment of localized chronic periodontitis especially during the maintenance phase in non-surgical treatment

Transdifferentiation of Human Dental Pulp Stem Cells Into Oligoprogenitor Cells

Introduction: The nerve fibers in central nervous system are surrounded by myelin sheet which is formed by oligodendrocytes. Cell therapy based on oligodendrocytes and their precursors transplantation can hold a promising alternative treatment for myelin sheet repair in demyelinating diseases. Methods: Human Dental Pulp Stem Cells (hDPSCs) are noninvasive, autologous and easy available source with multipotency characteristics, so they are in focus of interest in regenerative medicine. In the present study, hDPSCs were differentiated into oligoprogenitor using glial induction media, containing Retinoic Acid (RA), basic Fibroblast Growth Factor (bFGF), Platelet- Derived Growth Factor (PDGF), N2 and B27. The differentiated Oligoprogenitor Cells (OPCs) were evaluated for nestin, Olig2, NG2 and O4 using immunocytochemistry. Also, the expression of nestin, Olig2 and PDGFR-alpha gens (neuroprogenitor and oligoprogenitor markers) were investigated via RT-PCR technique. Results: The results indicate that glial differentiation medium induces the generation of oligoprogenitor cells as revealed via exhibition of specific glial markers, including Olig2, NG2 and O4. The expersion of nestin gene (neuroprogenitor marker) and Olig2 and PDGFR-alpha genes (oligoprogentor markers) were detected in treated hDPSCs at the end of the induction stage. Conclusion: hDPSCs can be induced to transdifferentiate into oligoprogenitor cells and respond to the routinely applied regents for glial differentiation of mesanchymal stem cells. These data suggest the hDPSCs as a valuable source for cell therapy in neurodegenerative diseases

PCR-RFLP detection of Haemoproteus spp. (Haemosporida: Haemoproteidae) in pigeon blood samples from Iran

This study was carried out to determine Haemoproteus spp. infection in pigeons in Iran. Blood sam-ples collected from pigeons were examined for Haemoproteus spp. using stained blood smears and polymerase chain reaction (PCR). For PCR, DNA was extracted from blood samples and a fragment of 617 bp in size subjected to PCR using HAEMF and HAEMR2 derived from cytochrome b gene of the parasite mitochondrial genome. A total number of 93 blood samples from pigeons were examined for Haemoproteus spp. of which 13 (13.97%) samples were positive in stained blood smears for Haemoproteus spp. and 27 (24.73%) were positive in PCR. Digestion of PCR product with AluI re-striction endonuclease generated only one distinct pattern for all positive samples, which is indicative of identical Haemoproteus spp. presence in infected pigeons. The results also revealed that PCR had higher sensitivity in detecting Haemoproteus spp. in pigeons

Serum protein alterations in goats naturally infected with Babesia ovis

Summary This study was conducted to determine the electrophoretic pattern of serum protein in goats infected with Babesia ovis. Serum total protein was calculated and serum electrophoresis from 15 goats naturally infected with B. ovis as well as same number of healthy goats was performed. Microscopic examination of Giemsastained peripheral blood smears revealed B. ovis infection. The parasitological diagnosis was confirmed using polymerase chain reaction (PCR) assay by using a pair of B. ovis-specific primers. Mean values total protein and α and γ globulin fractions in infected goats were significantly higher (P<0.05) than those observed in the healthy group