Publications by authors named "Rahim Nosrati"

20 Publications

  • Page 1 of 1

Biosensing of microcystins in water samples; recent advances.

Biosens Bioelectron 2020 Oct 27;165:112403. Epub 2020 Jun 27.

Department of Analytical Chemistry, University of Valencia, Dr. Moliner 50, 46100, Burjassot, Valencia, Spain. Electronic address:

Safety and quality of water are significant matters for agriculture, animals and human health. Microcystins, as secondary metabolite of cyanobacteria (blue-green algae) and cyclic heptapeptide cyanotoxin, are one of the main marine toxins in continental aquatic ecosystems. More than 100 microcystins have been identified, of which MC-LR is the most important type due to its high toxicity and common detection in the environment. Climate change is an impressive factor with effects on cyanobacterial blooms as source of microcystins. The presence of this cyanotoxin in freshwater, drinking water, water reservoir supplies and food (vegetable, fish and shellfish) has created a common phenomenon in eutrophic freshwater ecosystems worldwide. International public health organizations have categorized microcystins as a kind of neurotoxin and carcinogen. There are several conventional methods for detection of microcystins. The limitations of traditional methods have encouraged the development of innovative methods for detection of microcystins. In recent years, the developed sensor techniques, with advantages, such as accuracy, reproducibility, portability and low cost, have attracted considerable attention. This review compares the well-known of biosensor types for detection of microcystins with a summary of their analytical performance.
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http://dx.doi.org/10.1016/j.bios.2020.112403DOI Listing
October 2020

Current insights into the metastasis of epithelial ovarian cancer - hopes and hurdles.

Cell Oncol (Dordr) 2020 Aug 16;43(4):515-538. Epub 2020 May 16.

Department of Medical Genetics and Molecular Medicine, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran.

Background: Ovarian cancer is the most lethal gynecologic cancer and the fifth leading cause of cancer-related mortality in women worldwide. Despite various attempts to improve the diagnosis and therapy of ovarian cancer patients, the survival rate for these patients is still dismal, mainly because most of them are diagnosed at a late stage. Up to 90% of ovarian cancers arise from neoplastic transformation of ovarian surface epithelial cells, and are usually referred to as epithelial ovarian cancer (EOC). Unlike most human cancers, which are disseminated through blood-borne metastatic routes, EOC has traditionally been thought to be disseminated through direct migration of ovarian tumor cells to the peritoneal cavity and omentum via peritoneal fluid. It has recently been shown, however, that EOC can also be disseminated through blood-borne metastatic routes, challenging previous thoughts about ovarian cancer metastasis.

Conclusions: Here, we review our current understanding of the most updated cellular and molecular mechanisms underlying EOC metastasis and discuss in more detail two main metastatic routes of EOC, i.e., transcoelomic metastasis and hematogenous metastasis. The emerging concept of blood-borne EOC metastasis has led to exploration of the significance of circulating tumor cells (CTCs) as novel and non-invasive prognostic markers in this daunting cancer. We also evaluate the role of tumor stroma, including cancer associated fibroblasts (CAFs), tumor associated macrophages (TAMs), endothelial cells, adipocytes, dendritic cells and extracellular matrix (ECM) components in EOC growth and metastasis. Lastly, we discuss therapeutic approaches for targeting EOC. Unraveling the mechanisms underlying EOC metastasis will open up avenues to the design of new therapeutic options. For instance, understanding the molecular mechanisms involved in the hematogenous metastasis of EOC, the biology of CTCs, and the detailed mechanisms through which EOC cells take advantage of stromal cells may help to find new opportunities for targeting EOC metastasis.
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http://dx.doi.org/10.1007/s13402-020-00513-9DOI Listing
August 2020

Zinc solubilization characteristics of efficient siderophore-producing soil bacteria.

Iran J Microbiol 2019 Oct;11(5):419-430

Center of Excellence in Electrochemistry, Faculty of Chemistry, University of Tehran, Tehran, Iran.

Background And Objectives: Iron and zinc are two essential micro-nutrients for plant growth and development. Therefore, isolation of siderophores-producing and zinc-solubilizing rhizobacteria involved in bio-availability of these elements is of great interest.

Materials And Methods: In this study, soil samples collected from slightly alkaline soil types were screened for high levels of siderophore secretion and zinc solubilization.

Results: Among positive colonies, three isolates, named F21A, F37 and F38, were able to secrete siderophore at high levels, ranged between 200 and 300 μM/liter. A close association was observed between siderophore production capability and growth rate as an indicator of active metabolism. Siderophore production was closely correlated with the level of zinc ion released into the medium as well. All three siderophore producing isolates were able to withstand temperature as high as 37°C, high concentration of NaCl (up to 2.5%) and a wide range of initial pH from 6 to 9 while hydrolyzing Zn compounds actively. One of the isolates, F21A, tolerated the presence of 200 mgl of zinc. Biochemical and molecular characteristics are indicative that these isolates are . As experienced in a greenhouse experiment, inoculation with the F21A and F37 isolates significantly increase the plants height, fresh and dry weight of corn with compared to control.

Conclusion: These findings demonstrated that the potential of strains as plants growth promoting rhizobacteria (PGPR) in iron and zinc deficient soils.
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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7049313PMC
October 2019

Prognostic and therapeutic significance of circulating tumor cells in patients with lung cancer.

Cell Oncol (Dordr) 2020 Feb 11;43(1):31-49. Epub 2019 Dec 11.

Hematology, Oncology and Stem Cell Transplantation Research Center, Shariati Hospital, Tehran University of Medical Sciences, Tehran, Iran.

Background: Lung cancer is the second most common cancer and the main cause of cancer-related mortality worldwide. In spite of various efforts that have been made to facilitate the early diagnosis of lung cancer, most patients are diagnosed when the disease is already in stage IV, which is generally associated with the occurrence of distant metastases and a poor survival. Moreover, a large proportion of these patients will relapse after treatment, heralding the need for the stratification of lung cancer patients in addition to identifying those who are at a higher risk of relapse and, thus, require alternative and/or additional therapies. Recently, circulating tumor cells (CTCs) have been considered as valuable markers for the early diagnosis, prognosis and risk stratification of cancer patients, and they have been found to be able to predict the survival of patients with various types of cancer, including lung cancer. Additionally, the characterization of CTCs has recently provided fascinating insights into the heterogeneity of tumors, which may be instrumental for the development of novel targeted therapies.

Conclusions: Here we review our current understanding of the significance of CTCs in lung cancer metastasis. We also discuss prominent studies reporting the utility of enumeration and characterization of CTCs in lung cancer patients as prognostic and pharmacodynamic biomarkers for those who are at a higher risk of metastasis and drug resistance.
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http://dx.doi.org/10.1007/s13402-019-00470-yDOI Listing
February 2020

Optical and electrochemical-based nano-aptasensing approaches for the detection of circulating tumor cells (CTCs).

Biosens Bioelectron 2020 Jan 1;148:111833. Epub 2019 Nov 1.

Pharmaceutical Research Center, Pharmaceutical Technology Institute, Mashhad University of Medical Sciences, Mashhad, Iran. Electronic address:

More recently, detection of circulating tumor cells (CTCs) has been considered as an appealing prognostic and diagnostic approach for cancer patients. CTCs as a type of tumor-derived cells are secreted by the tumor and released into the blood circulation. Since the migration of CTCs is an early event in cancer progression, patients who still have tumor-free lymph nodes have to be well examined for the CTCs presence in their blood circulation. Nowadays, there is a broad range of detection methods available to identify CTCs. As artificial RNA oligonucleotides or single-stranded DNA with receptor and catalytic characteristics, aptamers have been standing out, owing to their target-induced conformational modifications, elevated stability, and target specificity to be implemented in biosensing techniques. To date, several sensitivity-enhancement methods alongside smart nanomaterials have been used for the creation of new aptasensors to address the limit of detection (LOD), and improve the sensitivity of numerous analyte identification methods. The present review article supports a focused overview of the recent studies in the identification and quantitative determination of CTCs by aptamer-based biosensors and nanobiosensors.
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http://dx.doi.org/10.1016/j.bios.2019.111833DOI Listing
January 2020

Electrochemical-based biosensors for detection of and tuberculosis biomarkers.

Crit Rev Biotechnol 2019 Dec 25;39(8):1056-1077. Epub 2019 Sep 25.

Biotechnology Research Center, Pharmaceutical Technology Institute, Mashhad University of Medical Sciences , Mashhad , Iran.

Early detection of tuberculosis (TB) reduces the interval between infection and the beginning of treatment. However, commercially available tests cannot discriminate between BCG-vaccinated healthy persons and patients. Also, they are not suitable to be used for immunocompromised persons. In recent years, biosensors have attracted great attention due to their simple utility, accessibility, and real-time outputs. These sensors are increasingly being considered as pioneering tools for point-of-care diagnostics in communities with a high burden of TB and limited accessibility to reference laboratories. Among other types of biosensors, the electrochemical sensors have the advantages of low-cost operation, fast processing, simultaneous multi-analyte analyzing, operating with turbid samples, comparable sensitivity and readily available miniaturization. Electrochemical biosensors are sub-divided into several categories including: amperometric, impedimetric, potentiometric, and conductometric biosensors. The biorecognition element in electrochemical biosensors is usually based on antibodies (immunosensors), DNAs or PNAs (genosensors), and aptamers (aptasensors). In either case, whether an interaction of the antigen-antibody/aptamer or the hybridization of probe with target mycobacterial DNA is detected, a change in the electrical current occurs that is recorded and displayed as a plot. Therefore, impedimetric-based methods evaluate resistance to electron transfer toward an electrode by a Nyquist plot and amperometric/voltammetric-based methods weigh the electrical current by means of cyclic voltammetry, square wave voltammetry, and differential pulse voltammetry. Electrochemical biosensors provide a promising scope for the new era of diagnostics. As a consequence, they can improve detection of traces even in attomolar scales.
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http://dx.doi.org/10.1080/07388551.2019.1668348DOI Listing
December 2019

Aptasensors as a new sensing technology developed for the detection of MUC1 mucin: A review.

Biosens Bioelectron 2019 Apr 15;130:1-19. Epub 2019 Jan 15.

Pharmaceutical Research Center, Pharmaceutical Technology Institute, Mashhad University of Medical Sciences, Mashhad, Iran. Electronic address:

Mucin 1 protein (MUC1) is a membrane-associated glycoprotein overexpressed in the majority of human malignancies and considered as a predominant protein biomarker in cancers. Owing to the crucial role of MUC1 in cancer dissemination and metastasis, detection and quantification of this biomarker is of great importance in clinical diagnostics. Today, there exist a wide variety of strategies for the determination of various types of disease biomarkers, especially MUC1. In this regard, aptamers, as artificial single-stranded DNA or RNA oligonucleotides with catalytic and receptor properties, have drawn lots of attention for the development of biosensing platforms. So far, various sensitivity-enhancement techniques in combination with a broad range of smart nanomaterials have integrated into the design of novel aptamer-based biosensors (aptasensors) to improve detection limit and sensitivity of analyte determination. This review article provides a brief classification and description of the research progresses of aptamer-based biosensors and nanobiosensors for the detection and quantitative determination of MUC1 based on optical and electrochemical platforms.
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http://dx.doi.org/10.1016/j.bios.2019.01.015DOI Listing
April 2019

SELEX methods on the road to protein targeting with nucleic acid aptamers.

Biochimie 2018 Nov 5;154:132-155. Epub 2018 Sep 5.

Pharmaceutical Research Center, Pharmaceutical Technology Institute, Mashhad University of Medical Sciences, Mashhad, Iran. Electronic address:

Systematic evolution of ligand by exponential enrichment (SELEX) is an efficient method used to isolate high-affinity single stranded oligonucleotides from a large random sequence pool. These SELEX-derived oligonucleotides named aptamer, can be selected against a broad spectrum of target molecules including proteins, cells, microorganisms and chemical compounds. Like antibodies, aptamers have a great potential in interacting with and binding to their targets through structural recognition and are therefore called "chemical antibodies". However, aptamers offer advantages over antibodies including smaller size, better tissue penetration, higher thermal stability, lower immunogenicity, easier production, lower cost of synthesis and facilitated conjugation or modification with different functional moieties. Thus, aptamers represent an attractive substitution for protein antibodies in the fields of biomarker discovery, diagnosis, imaging and targeted therapy. Enormous interest in aptamer technology triggered the development of SELEX that has underwent numerous modifications since its introduction in 1990. This review will discuss the recent advances in SELEX methods and their advantages and limitations. Aptamer applications are also briefly outlined in this review.
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http://dx.doi.org/10.1016/j.biochi.2018.09.001DOI Listing
November 2018

Nanomaterial-based biosensors and immunosensors for quantitative determination of cardiac troponins.

J Pharm Biomed Anal 2018 Sep 18;159:425-436. Epub 2018 Jul 18.

Department of Pharmacodynamics and Toxicology, School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Iran; Pharmaceutical Research Center, Pharmaceutical Technology Institute, Mashhad University of Medical Sciences, Mashhad, Iran. Electronic address:

Cardiovascular diseases (CVDs) are the most frequent mortality cause in many countries. The acute myocardial infraction (AMI) is one of the most common types of CVDs. Cardiac troponin I (cTnI) and cardiac troponin T (cTnT) as predominant cardiac infarction biomarkers considered as "gold standard" for diagnosis of acute myocardial infraction (AMI). The restrictions of traditional methods have encouraged the development of highly sensitive and specific methods for cTnI and cTnT detection. The rapid, early, reliable, and cost-effective diagnosis of CVDs not only helps with patient survival, but also save cost and time to prosperous prognosis. In recent years, the concept of biosensors has opened new horizons in high precision detection. Once combined with nanomaterials, nano-scale biosensors provide powerful analytical platforms for diagnosing of cTnI and cTnT. In this article, after a brief overview of the cardiac troponins, a classification and description of the research progresses of biosensors and immunosensors for the detection and quantitative determination of cardiac troponins based on optical and electrochemical platforms are presented.
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http://dx.doi.org/10.1016/j.jpba.2018.07.031DOI Listing
September 2018

Screening and characterization of probiotic criteria of and strains.

Iran J Microbiol 2018 Apr;10(2):123-131

Molecular Microbiology Research Center (MMRC), Faculty of Medicine, Shahed University, Tehran, Iran.

Background And Objectives: Probiotics are defined as live micro-organisms conferring a health benefit on the host. Although most probiotics are bacteria, some yeasts such as and , has been found to have effective probiotic properties. The objective of this study was to isolate and identify indigenous and yeast strains and to compare some probiotic characteristics between these two strains .

Materials And Methods: Strains were isolated on yeast glucose chloramphenicol agar medium from 205 samples and identified by morphological, physiological and biochemical assays. The effects of different conditions such as pH and temperature on the survival and growth of the isolates were studied. In addition, resistance to acidic pH (1.5, 2, 3 and 5), pepsin and different concentrations of bile salts (1%, 3% and 5%), as well as proteolytic, lipolytic and hemolytic activity of selected isolates were assessed. Finally, the best isolates were selected for investigation of their viability in samples of dairy products.

Results: 126 isolates were identified using biochemical and molecular techniques as yeast strains. Five isolates were found to have effective probiotic properties, belonging to (S97, S101 and S106) and (S28, S34). These isolates were able to grow at 37°C, pH=1.5, withstand to concentration of 5% oxbile and pepsin and exhibit the proteolytic activity. The isolates of showed better viability in dairy (yogurt).

Conclusion: In the comparative experiments, the isolates of showed better probiotic potentials.
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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6039453PMC
April 2018

Nano-biosensing approaches on tuberculosis: Defy of aptamers.

Biosens Bioelectron 2018 Oct 11;117:319-331. Epub 2018 Jun 11.

Biotechnology Research Center, Pharmaceutical Technology Institute, Mashhad University of Medical Sciences, Mashhad, Iran; Mediphage Bioceuticals, Inc., 661 University Avenue, Suite 1300, MaRS Centre, West Tower, Toronto, Canada. Electronic address:

Tuberculosis is a major global health problem caused by the bacterium Mycobacterium tuberculosis (Mtb) complex. According to WHO reports, 53 million TB patients died from 2000 to 2016. Therefore, early diagnosis of the disease is of great importance for global health care programs. The restrictions of traditional methods have encouraged the development of innovative methods for rapid, reliable, and cost-effective diagnosis of tuberculosis. In recent years, aptamer-based biosensors or aptasensors have drawn great attention to sensitive and accessible detection of tuberculosis. Aptamers are small short single-stranded molecules of DNA or RNA that fold to a unique form and bind to targets. Once combined with nanomaterials, nano-scale aptasensors provide powerful analytical platforms for diagnosing of tuberculosis. Various groups designed and studied aptamers specific for the whole cells of M. tuberculosis, mycobacterial proteins and IFN-γ for early diagnosis of TB. Advantages such as high specificity and strong affinity, potential for binding to a larger variety of targets, increased stability, lower costs of synthesis and storage requirements, and lower probability of contamination make aptasensors pivotal alternatives for future TB diagnostics. In recent years, the concept of SOMAmer has opened new horizons in high precision detection of tuberculosis biomarkers. This review article provides a description of the research progresses of aptamer-based and SOMAmer-based biosensors and nanobiosensors for the detection of tuberculosis.
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http://dx.doi.org/10.1016/j.bios.2018.06.025DOI Listing
October 2018

Siderophore-based biosensors and nanosensors; new approach on the development of diagnostic systems.

Biosens Bioelectron 2018 Oct 30;117:1-14. Epub 2018 May 30.

Pharmaceutical Research Center, Pharmaceutical Technology Institute, Mashhad University of Medical Sciences, Mashhad, Iran. Electronic address:

Siderophores are small organic compounds secreted by microorganisms under iron-depleted conditions which enhance the uptake of iron. Siderophores can play vital roles in ecology, agriculture, bioremediation, biosensor, and medicine. In recent years, the concept of siderophore-based biosensing devices has opened new horizons in high precision detection of various metal ions especially the iron, microorganisms, phosphopeptides, antibiotics as well pesticides. Once combined with nanomaterials, nano-scale siderophore systems provide powerful analytical platforms for detection of low concentration of metal ions and numerous pathogens. In this article, a brief overview of general aspects of siderophore is firstly discussed. In addition, a clear and concise review of recent advances of siderophore-based biosensors (siderosensor) and nanosensors are mainly discussed herein. Subsequently, future perspectives and challenges of siderophore-based sensors are discussed briefly.
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http://dx.doi.org/10.1016/j.bios.2018.05.057DOI Listing
October 2018

Label-free nano-biosensing on the road to tuberculosis detection.

Biosens Bioelectron 2018 Aug 1;113:124-135. Epub 2018 May 1.

Laboratory of Toxicology, Medical School, University of Crete, Voutes, Heraklion, Crete 71003, Greece.

Tuberculosis, an ailment caused by the bacterium Mycobacterium tuberculosis (Mtb) complex, is one of the catastrophic transmittable diseases that affect human. Reports published by WHO indicate that in 2017 about 6.3 million people progressed to TB and 53 million TB patients died from 2000 to 2016. Therefore, early diagnosis of the disease is of great importance for global health care programs. Common diagnostics like the traditional PPD test and antibody-assisted assays suffer the lack of sensitivity, long processing time and cumbersome post-test proceedings. These shortcomings restrict their use and encourage innovations in TB diagnostics. In recent years, the biosensor concept opened up new horizons in sensitive and fast detection of the disease, reducing the interval time between sampling and diagnostic result. Among new diagnostics, label-free nano-biosensors are highly promising for sensitive and accessible detection of tuberculosis. Various specific label-free nano-biosensors have been recently reported detecting the whole cell of M. tuberculosis, mycobacterial proteins and IFN-γ as crucial markers in early diagnosis of TB. This article provides a focused overview on nanomaterial-based label-free biosensors for tuberculosis detection.
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http://dx.doi.org/10.1016/j.bios.2018.04.059DOI Listing
August 2018

Aptamer-based biosensors and nanosensors for the detection of vascular endothelial growth factor (VEGF): A review.

Biosens Bioelectron 2018 Jul 19;110:23-37. Epub 2018 Mar 19.

Pharmaceutical Research Center, Pharmaceutical Technology Institute, Mashhad University of Medical Sciences, Mashhad, Iran. Electronic address:

Vascular endothelial growth factor (VEGF) is a key regulator of vascular formation and a predominant protein biomarker in cancer angiogenesis. Owing to its crucial roles in the cancer metastasis, VEGF detection and quantification is of great importance in clinical diagnostics. Today, there exist a wide variety of detection strategies for identifying many types of disease biomarkers, especially for VEGF. As artificial single-stranded DNA or RNA oligonucleotides with catalytic and receptor properties, aptamers have drawn lots of attention to be applied in biosensing platforms due to their target-induced conformational changes as well as high stability and target versatility. So far, various sensitivity-enhancement techniques in combination with a broad range of smart nanomaterials have integrated into the design of novel aptasensors to improve detection limit and sensitivity of analyte detection. This review article provides a brief classification and description of the research progresses of aptamer-based biosensors and nanobiosensors for the detection and quantitative determination of VEGF based on optical and electrochemical platforms.
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http://dx.doi.org/10.1016/j.bios.2018.03.037DOI Listing
July 2018

Organ-specific metastasis of breast cancer: molecular and cellular mechanisms underlying lung metastasis.

Cell Oncol (Dordr) 2018 Apr 22;41(2):123-140. Epub 2018 Mar 22.

Department of Medical Genetics, Faculty of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran.

Background: Breast cancer (BC) is the most common type of cancer in women and the second cause of cancer-related mortality world-wide. The majority of BC-related deaths is due to metastasis. Bone, lung, brain and liver are the primary target sites of BC metastasis. The clinical implications and mechanisms underlying bone metastasis have been reviewed before. Given the fact that BC lung metastasis (BCLM) usually produces symptoms only after the lungs have been vastly occupied with metastatic tumor masses, it is of paramount importance for diagnostic and prognostic, as well as therapeutic purposes to comprehend the molecular and cellular mechanisms underlying BCLM. Here, we review current insights into the organ-specificity of BC metastasis, including the role of cancer stem cells in triggering BC spread, the traveling of tumor cells in the blood stream and their migration across endothelial barriers, their adaptation to the lung microenvironment and the initiation of metastatic colonization within the lung.

Conclusions: Detailed understanding of the mechanisms underlying BCLM will shed a new light on the identification of novel molecular targets to impede daunting pulmonary metastases in patients with breast cancer.
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http://dx.doi.org/10.1007/s13402-018-0376-6DOI Listing
April 2018

Lung cancer-associated brain metastasis: Molecular mechanisms and therapeutic options.

Cell Oncol (Dordr) 2017 Oct 18;40(5):419-441. Epub 2017 Sep 18.

Hematology, Oncology and Stem Cell Transplantation Research Center, Shariati Hospital, Tehran University of Medical Sciences, Tehran, Iran.

Background: Lung cancer is the most common cause of cancer-related mortality in humans. There are several reasons for this high rate of mortality, including metastasis to several organs, especially the brain. In fact, lung cancer is responsible for approximately 50% of all brain metastases, which are very difficult to manage. Understanding the cellular and molecular mechanisms underlying lung cancer-associated brain metastasis brings up novel therapeutic promises with the hope to ameliorate the severity of the disease. Here, we provide an overview of the molecular mechanisms underlying the pathogenesis of lung cancer dissemination and metastasis to the brain, as well as promising horizons for impeding lung cancer brain metastasis, including the role of cancer stem cells, the blood-brain barrier, interactions of lung cancer cells with the brain microenvironment and lung cancer-driven systemic processes, as well as the role of growth factor/receptor tyrosine kinases, cell adhesion molecules and non-coding RNAs. In addition, we provide an overview of current and novel therapeutic approaches, including radiotherapy, surgery and stereotactic radiosurgery, chemotherapy, as also targeted cancer stem cell and epithelial-mesenchymal transition (EMT)-based therapies, micro-RNA-based therapies and other small molecule or antibody-based therapies. We will also discuss the daunting potential of some combined therapies.

Conclusions: The identification of molecular mechanisms underlying lung cancer metastasis has opened up new avenues towards their eradication and provides interesting opportunities for future research aimed at the development of novel targeted therapies.
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http://dx.doi.org/10.1007/s13402-017-0345-5DOI Listing
October 2017

Isolation of indigenous Glutathione producing strains.

Iran J Pathol 2016 ;11(4):354-362

Molecular Microbiology Research Center, Shahed University, Tehran, Iran.

Background: Glutathione (GSH) is a non-protein thiol compound, which plays an important role in the response to oxidative stress and nutritional stress. The aim of this study was to isolate indigenous strains capable of effectively produce GSH.

Methods: One hundred-twenty sweet fruit samples were collected. The strains were isolated on yeast glucose chloramphenicol (YGC) agar medium and identified. The isolates were evaluated for GSH producing on yeast malt (YM) medium. Concentration of glutathione was investigated by recording absorbance of all samples at wavelength 412 nm (Ellman's method). In addition, optimization of glucose and peptone concentration in culture medium and the effects of various environmental conditions such as temperature (20-35 °C), agitation rate (150-250 rpm), and initial pH (4.0-6.0) were assessed on producing of GSH.

Results: From 120 samples, 80 isolates were identified by morphological, biochemical and molecular tests as . Five isolates were capable to produce effectively GSH. The optimal culture conditions were agitation rate, 200 rpm; temperature, 30 °C; initial pH, 6; glucose, 30 g/l; and peptone concentration, 5 g/l. In optimal conditions, the amount of derived glutathione was improved compared to YM basal medium and highest GSH concentration (296.8 mg/l) was obtained after cultivation with shaking for 72 h.

Conclusion: The possibility of obtaining cells with a high GSH intracellular content can be considered an interesting opportunity of furthering the range of application and utilization of this molecule.
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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5563933PMC
January 2016

Analysis of virulence genes and accessory gene regulator (agr) types among methicillin-resistant Staphylococcus aureus strains in Iran.

J Glob Antimicrob Resist 2017 09 20;10:315-320. Epub 2017 Jul 20.

Department of Pathology and Laboratory Medicine, Tehran Heart Center, Tehran University of Medical Sciences, North Karegar Ave., Tehran 1411713138, Iran. Electronic address:

Objectives: Methicillin-resistant Staphylococcus aureus (MRSA) strains are a major cause of hospital-acquired infections and are considered a serious public health concern. MRSA isolates have abundant virulence factors that are the basis for their pathogenicity. The accessory gene regulator (agr) locus co-ordinates the expression of these genes. The aim of this study was to determine the presence and frequency of various virulence genes encoding enterotoxins and adhesins as well as to identify agr specificity groups in MRSA isolates.

Methods: This descriptive study included a total of 296 MRSA strains isolated from clinical samples collected in Tehran Heart Center (Tehran, Iran) between October 2004 and March 2013. Following DNA extraction, PCR-based assays were used to evaluate the presence of various virulence genes. IBM SPSS Statistics for Windows v.21.0 was used for statistical analysis.

Results: The results indicated that the most frequent toxin genes were see (120/296; 40.5%), followed by sea (79/296; 26.7%); the other genes were encoded less frequently. The presence of seb and seh was not found in any of the isolates. Furthermore, the most frequent adhesin genes were clfA, spa, cna, map/eap and bbp, found in 281 (94.9%), 275 (92.9%), 267 (90.2%), 265 (89.5%) and 264 (89.2%) isolates, respectively. The majority of isolates belonged to agr group I (53.0%), followed by agr group III (1.4%). None of the isolates belonged to agr group II.

Conclusions: The relatively high frequency of various virulence genes suggests the emergence and pathogenic potential of MRSA isolates containing these genes in the study area.
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http://dx.doi.org/10.1016/j.jgar.2017.06.009DOI Listing
September 2017

Phosphate solubilization characteristics of efficient nitrogen fixing soil Azotobacter strains.

Iran J Microbiol 2014 Aug;6(4):285-95

National Institute of Genetic Engineering and Biotechnology (NIGEB), Tehran, I.R. Iran.

Background And Objectives: Azotobacter is a diazotroph bacterium reported to possess various plant growth-promoting characteristics.The aim of this study was to isolate Azotobacter strains capable of fixing nitrogen and effectively hydrolyzing both organic and inorganic Pi compounds.

Materials And Methods: In this study, soil samples collected from a diverse range of slightly alkaline soil types were screened for Azotobacter isolates. The inorganic and organic phosphate solubilization potentials of twenty competent phosphate solubilizing Azotobacter isolates were assessed.Variations were noted in the solubilization potentials.

Result: Three isolates, identified as Azotobacter vinelandii strains O2, O4 and O6, were able to fix atmospheric N2 effectively. The nitrogenase activity of these isolates ranged between 158.6 and 326.4 C2H4h(-1)vial(-1) (ethylene). Bacterial growth rates and phosphate solubilization activities were measured quantitatively under various environmental conditions. A close association was evident between phosphate solubilizing ability and growth rate as an indicator of active metabolism. All three phosphate solubilizing bacteria (PSB) were able to withstand temperature as high as 45°C, high concentration of NaCl (upto 5%) and a wide range of initial pH from 5 to 10 while hydrolyzing phosphate compounds actively.

Conclusion: Azotobacter vinelandii strains O2, O4 and O6 are superior candidates for biofertilizers that may result in the reduction of chemical nitrogen and phosphate fertilizers leading to increase crop production.
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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4367947PMC
August 2014

Antimicrobial susceptibility differences among mucoid and non-mucoid Pseudomonas aeruginosa isolates.

GMS Hyg Infect Control 2014 19;9(2):Doc13. Epub 2014 Aug 19.

Department of Microbiology, Faculty of Medicine, Iran University of Medical Sciences, Tehran, Iran ; Department of Microbiology, Faculty of Medicine, Tehran University of Medical Sciences, Tehran, Iran.

Pseudomonas aeruginosa is one of the most important opportunistic bacteria, causing a wide variety of infections particularly in immunocompromised patients. The extracellular glycocalyx is produced in copious amounts by mucoid strains of P. aeruginosa. Mucoid and non-mucoid P. aeruginosa strains show some differences in their antimicrobial susceptibility pattern. The aim of this study was to investigate the frequency of mucoid and non-mucoid types and their antimicrobial susceptibility patterns isolated from Milad and Mostafa Khomeini Hospital in Tehran, Iran. One hundred P. aeruginosa isolates were collected which all were confirmed by conventional biochemical tests and PCR assay using specific primers for oprI and oprL lipoproteins. Mucoid and non-mucoid types of isolates were determined by culturing isolates on BHI agar containing Congo red and Muir mordant staining method. The susceptibility pattern of isolates against 23 different antibiotics was assessed using MIC sensititre susceptibility plates. Fifty of 100 of isolates were mucoid type, of which 14 isolates were from Mostafa Khomeini Hospital. Frequency of mucoid type of P. aeruginosa in Mostafa Khomeini hospital (70%) was higher than that seen in Milad hospital (45%). The statistical analysis of MICs results showed significant differences in antimicrobial resistance among mucoid and non-mucoid types (non mucoid strains showed more resistance against tested antibiotics). This may be due to the tendency of some antibiotics to attach to extracellular glycocalyx of mucoid strains.
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http://dx.doi.org/10.3205/dgkh000233DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4141634PMC
August 2014