19 research outputs found

    Hepatoxicity of aqueous extract and fractionated methanol extract of Phytolacca americana by isolated rat liver perfusion system

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    Recombinant retroviral vector containing human tissue inhibitor of matrix metalloproteinase-2 (TIMP-2) gene was constructed and investigation of the in vitro invasion and metastasis of gastric cancer cells transfected with TIMP-2 was carried out. Human TlMP-2 was isolated from recombinant vector Bluescript 1/TIMP-2(+), and then inserted into the retroviral vector pL-MT. Correct orientation was verified by restriction endonuclease digestion. Human full length TIMP-2 gene was ligated into a plasmid, which was then transfected into PA317 cell line. G418-resistant individual clones were selected to transfect human SGC-7901 cell line. Cell proliferation, cell electrophoresis, soft agar colony formation and in vitro invasion were detected to analyze the bio-behavioral changes of cancer cells. The results from restriction endonuclease digestion were as theoretically expected. The cell electrophoresis rate, colony number and invasion ability in SGC-7901 cells and MFC cells transfected with TIMP-2 gene were significantly decreased when compared with control group. However, no significant changes were noted in the proliferation of cancer cells. We successfully construct a recombinant retroviral vector containing human TIMP-2. TIMP-2 transfection could markedly alter the membrane charge of cancer cells, resulting in decreased electrophoresis capacity, cell migration and invasion. However, cell growth was not affected by TIMP-2. These results suggested TIMP-2 transfection might exert effects on the malignant phenotype of cancer cells through affecting extracellular environment, which provided a new way to investigate gene regulation of in vitro collagen metabolism

    Expression, Tissue Distribution and Function of miR-21 in Esophageal Squamous Cell Carcinoma

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    Objective:MiR-21 is an oncomir expressed by malignant cells and/or tumor microenvironment components. In this study we focused on understanding the effects of stromal miR-21 on esophageal malignant cells.Design:MiR-21 expression was evaluated in formalin-fixed paraffin-embedded samples from patients with esophageal squamous-cell carcinoma (SCC) by quantitative RT-PCR. MiR-21 tissue distribution was visualized with in situ hybridization. A co-culture system of normal fibroblasts and esophageal cancer cells was used to determine the effects of fibroblasts on miR-21 expression levels, and on SCC cell migration and invasion.Results:MiR-21 was overexpressed in SCCs, when compared to the adjacent non-tumor tissues (P = 0.0007), and was mainly localized in the cytoplasm of stromal cells adjacent to malignant cells. Accordingly, miR-21 expression was increased in tumors with high versus low stromal content (P = 0.04). When co-cultured with normal fibroblasts, miR-21 expression was elevated in SCC cells (KYSE-30), while its expression was restricted to fibroblasts when co-cultured with adenocarcinoma cells (OE-33 and FLO-1). MiR-21 was detected in conditioned media of cancer cell lines, illustrating the release of this miRNA into the environment. Co-culturing with normal fibroblasts or addition of fibroblast conditioned media caused a significant increase in cell migration and invasion potency of KYSE-30 cells (P<0.0001). In addition, co-culturing cancer cells with fibroblasts and expression of miR-21 induced the expression of the cancer associated fibroblast (CAF) marker S100A4.Conclusions:MiR-21 expression is mostly confined to the SCC stroma and its release from fibroblasts influences the migration and invasion capacity of SCC cells. Moreover, miR-21 may be an important factor in "activating" fibroblasts to CAFs. These findings provide new insights into the role of CAFs and the extracellular matrix in tumor microenvironment formation and in tumor cell maintenance, and suggest miR-21 may contribute to cellular crosstalk in the tumor microenvironment. © 2013 Nouraee et al

    Robotic Wireless Sensor Networks

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    In this chapter, we present a literature survey of an emerging, cutting-edge, and multi-disciplinary field of research at the intersection of Robotics and Wireless Sensor Networks (WSN) which we refer to as Robotic Wireless Sensor Networks (RWSN). We define a RWSN as an autonomous networked multi-robot system that aims to achieve certain sensing goals while meeting and maintaining certain communication performance requirements, through cooperative control, learning and adaptation. While both of the component areas, i.e., Robotics and WSN, are very well-known and well-explored, there exist a whole set of new opportunities and research directions at the intersection of these two fields which are relatively or even completely unexplored. One such example would be the use of a set of robotic routers to set up a temporary communication path between a sender and a receiver that uses the controlled mobility to the advantage of packet routing. We find that there exist only a limited number of articles to be directly categorized as RWSN related works whereas there exist a range of articles in the robotics and the WSN literature that are also relevant to this new field of research. To connect the dots, we first identify the core problems and research trends related to RWSN such as connectivity, localization, routing, and robust flow of information. Next, we classify the existing research on RWSN as well as the relevant state-of-the-arts from robotics and WSN community according to the problems and trends identified in the first step. Lastly, we analyze what is missing in the existing literature, and identify topics that require more research attention in the future

    Opportunistic Routing with Congestion Diversity in Wireless Multi-hop Networks

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    Abstract-This paper considers the problem of routing packets across a multi-hop network consisting of multiple sources of traffic and wireless links with stochastic reliability while ensuring bounded expected delay. Each packet transmission can be overheard by a random subset of receiver nodes among which the next relay/router is selected opportunistically. The main challenge in the design of minimum-delay routing policies is balancing the tradeoff between routing the packets along the shortest paths to the destination and controlling the congestion and distributing traffic uniformly across the network. Simple opportunistic variants of shortest path routing may, under heavy traffic scenarios, result in severe congestion and unbounded delay. While the opportunistic variants of backpressure, which ensure a bounded expected delay, are known to exhibit extremely poor delay performance at low to medium traffic conditions. Combining important aspects of shortest path routing with those of backpressure routing, this paper provides an opportunistic routing policy with congestion diversity (ORCD). ORCD uses a measure of draining time to opportunistically identify and route packets along the paths with an expected low overall congestion. Using a novel Lyapunov function construction, ORCD is proved to ensure a bounded expected delay for all networks and under any admissible traffic (without any knowledge of traffic statistics). Furthermore, the expected delay encountered by the packets in the network under ORCD is compared against known existing routing policies via simulations and substantial improvements are observed. Finally, the paper proposes practical implementations and discusses criticality of various assumptions in the analysis

    Status of estrogene, progesterone receptors and HER-2/neu expression in invasive breast cancer

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    Background&Objective: The breast cancer is the most common malignancy in women. The normal and malignant breast tissue are under the regulatory effects of esteroid hormones and growth factors including HER-2/neu. The purpose of this study, is to determine the expression of estrogene receptor (ER) progesterone receptor(PR) and HER-2/neu among Iranian women with invasive breast cancer. Materials&Methods: The study is descriptive and cross-sectional that was performed on 50 samples of patients with invasive breast cancer in Imam-Khomeini Hospital-Sari (2005-06). After preparing the samples four tissue sections from each sample was obtained then H&E and IHC staining were performed. Results: In our study, the patients were between 28-88 yrs, (mean:52/6). ER and PR and HER-2/neu were positive in 80%, 72% and 57.1% of cases, respectively. Concurrent positive ER and PR was 70%, meanwhile 62.9% of these patient were also positive for HER-2/neu. 20% of the cases showed negativity for both ER and PR and of these 83.4% were also negative for HER-2/neu. Conclusion: In our study ER expression by itself is equal to previous studies in textbooks but PR expression, HER-2/neu and concurrent expression of ER&PR are higher in our study. Interestingly HER-2/neu expression is near to what was previously proposed by Iranian Blood Transfusion Organization and Kerman University of Medical science. It seems that racial and geographic factors are contributed for these diffrences

    Effects of some natural products from fungal and herbal sources on Giardia lamblia in vivo

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    Giardia lamblia (G. lamblia) is the most widely known protozoan parasite that causes human gastrointestinal infection worldwide. Some natural compounds exhibited pivotal effects against different infectious diseases. In this research, the antigiardial activity and cytotoxicity of fungal chitosan, nano-chitosan, Rhamnus cathartica (R. cathartica) and emodin were evaluated in Balb/c mice. Genotyping of G. lamblia was assessed by PCR-RFLP technique. Different concentrations of mentioned compounds were used to check their antigiardial and cytotoxicity effects on human intestinal epithelial cells (HT-29) after 24, 48 and 72 h. The G. lamblia strain used in the current work was genotyped and revealed as an AII assemblage. All the concentration showed acceptable activity against G. lamblia cysts and trophozoites in comparison to the negative and positive controls (furazolidone and metronidazole) in vitro (P &lt; 0.05). Giardia lamblia cysts were susceptible after treatment in all experiments in vivo in comparison to negative control (P &lt; 0.05). Approximately, in most of the concentration, nano-chitosan and emodin were more effective than chitosan and R. cathartica, respectively (P &lt; 0.05). The effects of exposure times in antigiardial and cytotoxicity effects were not statistically significant (P &gt; 0.05). The maximum mortality rate (100) was achieved at 100 and 50 μg kg -1 concentrations after 48 and 72 h of exposure time, respectively. Our results provide significant information about the new antigiardial agent and proposed the nano-chitosan and emodin for the development of new drugs against G. lamblia in the future. Copyright © Cambridge University Press 2019
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