WorldWideScience

Sample records for chemoprevention protocols requirements

  1. Sirt1 Is Required for Resveratrol-Mediated Chemopreventive Effects in Colorectal Cancer Cells

    Directory of Open Access Journals (Sweden)

    Constanze Buhrmann

    2016-03-01

    Full Text Available Sirt1 is a NAD+-dependent protein-modifying enzyme involved in regulating gene expression, DNA damage repair, metabolism and survival, as well as acts as an important subcellular target of resveratrol. The complex mechanisms underlying Sirt1 signaling during carcinogenesis remain controversial, as it can serve both as a tumor promoter and suppressor. Whether resveratrol-mediated chemopreventive effects are mediated via Sirt1 in CRC growth and metastasis remains unclear; which was the subject of this study. We found that resveratrol suppressed proliferation and invasion of two different human CRC cells in a dose-dependent manner, and interestingly, this was accompanied with a significant decrease in Ki-67 expression. By transient transfection of CRC cells with Sirt1-ASO, we demonstrated that the anti-tumor effects of resveratrol on cells was abolished, suggesting the essential role of this enzyme in the resveratrol signaling pathway. Moreover, resveratrol downregulated nuclear localization of NF-κB, NF-κB phosphorylation and its acetylation, causing attenuation of NF-κB-regulated gene products (MMP-9, CXCR4 involved in tumor-invasion and metastasis. Finally, Sirt1 was found to interact directly with NF-κB, and resveratrol did not suppress Sirt1-ASO-induced NF-κB phosphorylation, acetylation and NF-κB-regulated gene products. Overall, our results demonstrate that resveratrol can suppress tumorigenesis, at least in part by targeting Sirt1 and suppression of NF-κB activation.

  2. Sirt1 Is Required for Resveratrol-Mediated Chemopreventive Effects in Colorectal Cancer Cells.

    Science.gov (United States)

    Buhrmann, Constanze; Shayan, Parviz; Popper, Bastian; Goel, Ajay; Shakibaei, Mehdi

    2016-03-05

    Sirt1 is a NAD⁺-dependent protein-modifying enzyme involved in regulating gene expression, DNA damage repair, metabolism and survival, as well as acts as an important subcellular target of resveratrol. The complex mechanisms underlying Sirt1 signaling during carcinogenesis remain controversial, as it can serve both as a tumor promoter and suppressor. Whether resveratrol-mediated chemopreventive effects are mediated via Sirt1 in CRC growth and metastasis remains unclear; which was the subject of this study. We found that resveratrol suppressed proliferation and invasion of two different human CRC cells in a dose-dependent manner, and interestingly, this was accompanied with a significant decrease in Ki-67 expression. By transient transfection of CRC cells with Sirt1-ASO, we demonstrated that the anti-tumor effects of resveratrol on cells was abolished, suggesting the essential role of this enzyme in the resveratrol signaling pathway. Moreover, resveratrol downregulated nuclear localization of NF-κB, NF-κB phosphorylation and its acetylation, causing attenuation of NF-κB-regulated gene products (MMP-9, CXCR4) involved in tumor-invasion and metastasis. Finally, Sirt1 was found to interact directly with NF-κB, and resveratrol did not suppress Sirt1-ASO-induced NF-κB phosphorylation, acetylation and NF-κB-regulated gene products. Overall, our results demonstrate that resveratrol can suppress tumorigenesis, at least in part by targeting Sirt1 and suppression of NF-κB activation.

  3. Sirt1 Is Required for Resveratrol-Mediated Chemopreventive Effects in Colorectal Cancer Cells

    Science.gov (United States)

    Buhrmann, Constanze; Shayan, Parviz; Popper, Bastian; Goel, Ajay; Shakibaei, Mehdi

    2016-01-01

    Sirt1 is a NAD+-dependent protein-modifying enzyme involved in regulating gene expression, DNA damage repair, metabolism and survival, as well as acts as an important subcellular target of resveratrol. The complex mechanisms underlying Sirt1 signaling during carcinogenesis remain controversial, as it can serve both as a tumor promoter and suppressor. Whether resveratrol-mediated chemopreventive effects are mediated via Sirt1 in CRC growth and metastasis remains unclear; which was the subject of this study. We found that resveratrol suppressed proliferation and invasion of two different human CRC cells in a dose-dependent manner, and interestingly, this was accompanied with a significant decrease in Ki-67 expression. By transient transfection of CRC cells with Sirt1-ASO, we demonstrated that the anti-tumor effects of resveratrol on cells was abolished, suggesting the essential role of this enzyme in the resveratrol signaling pathway. Moreover, resveratrol downregulated nuclear localization of NF-κB, NF-κB phosphorylation and its acetylation, causing attenuation of NF-κB-regulated gene products (MMP-9, CXCR4) involved in tumor-invasion and metastasis. Finally, Sirt1 was found to interact directly with NF-κB, and resveratrol did not suppress Sirt1-ASO-induced NF-κB phosphorylation, acetylation and NF-κB-regulated gene products. Overall, our results demonstrate that resveratrol can suppress tumorigenesis, at least in part by targeting Sirt1 and suppression of NF-κB activation. PMID:26959057

  4. Chemoprevention of bladder cancer.

    Science.gov (United States)

    Kamat, Ashish M; Lamm, Donald L

    2002-02-01

    The data presented herein, although highly supportive for a protective role of various nutrients against bladder cancer, are far from definitive. Many authorities question the validity of current recommendations for nutritional chemoprevention against bladder cancer. The reason for the wide variations reported in epidemiologic studies lies in the nature of observational studies. Dietary studies are limited in their conclusions because the protection afforded by the consumption of a particular nutrient may be multifactorial, with different components of the food exerting potential chemopreventive effects. Furthermore, measuring levels of nutrients in the food intake of populations is confounded by factors that might affect these levels and also the incidence of cancer. For example, vitamin A can come from animal or vegetarian sources. Because animal fat has been identified as a potential carcinogen in man, depending on the source of the vitamin, varying levels of protection might be deduced. In addition, chemoprevention studies using dietary supplements are expected to have mild effects, and large studies would be required to confirm statistical significance. Even with agents such as intravesical chemotherapy, only half the studies achieve statistical significance [29]. Prospective randomized trials with a large sample size, longer follow-up, and an extended duration of treatment are needed to clarify the association between micronutrients and cancer protection. With these caveats in mind, several recommendations can be made. Simple measures, such as drinking more fluids (especially water), can have a profound impact on the incidence of bladder cancer. Vitamins are being extensively studied in chemopreventive trials for different cancers. There is strong evidence for a chemoprotective effect of vitamin A in bladder cancer. The authors recommend 32,000 IU/day of vitamin A initially, with lower doses (24,000 IU) for persons less than 50 kg. Because liver toxicity is a

  5. Chemoprevention by WR-2721

    Energy Technology Data Exchange (ETDEWEB)

    Grdina, D.J. [Argonne National Lab., IL (United States)]|[Chicago Univ., IL (United States). Dept. of Radiation and Cellular Oncology; Carnes, B.A. [Argonne National Lab., IL (United States)

    1993-05-01

    WR-2721 [S-2-(3-aminopropylamino)ethylphosphorothioic acid] is an effective chemopreventive agent. C57BL {times} BALB/c F{sub 1} female mice, were exposed to a single whole-body dose of 206 cGy from a {sup 60}Co photon source. Those groups treated with VATR-2721 (400 mg/kg) were administered the agent i.p. 30 min prior to irradiation. Over 90% of deaths were determined to be due to tumor involvement. WR-2721 afforded significant protection against life shortening due to radiation-induced tumors of connective tissue and epithelial tissue origins. Subsequent survival time in WR-2721-treated and irradiated animals as compared to matched irradiated-only controls was extended up to 59 days. A single exposure of animals to VVR-2721 did not affect the cumulative survival curves for unirradiated mice. WR-2721 possesses chemopreventive properties which can be clinically exploited to reduce the risk to therapy-induced secondary cancers in patients who otherwise would have an excellent prognosis for cure and long-term survival.

  6. Chemoprevention by WR-2721

    Energy Technology Data Exchange (ETDEWEB)

    Grdina, D.J. (Argonne National Lab., IL (United States) Chicago Univ., IL (United States). Dept. of Radiation and Cellular Oncology); Carnes, B.A. (Argonne National Lab., IL (United States))

    1993-01-01

    WR-2721 [S-2-(3-aminopropylamino)ethylphosphorothioic acid] is an effective chemopreventive agent. C57BL [times] BALB/c F[sub 1] female mice, were exposed to a single whole-body dose of 206 cGy from a [sup 60]Co photon source. Those groups treated with VATR-2721 (400 mg/kg) were administered the agent i.p. 30 min prior to irradiation. Over 90% of deaths were determined to be due to tumor involvement. WR-2721 afforded significant protection against life shortening due to radiation-induced tumors of connective tissue and epithelial tissue origins. Subsequent survival time in WR-2721-treated and irradiated animals as compared to matched irradiated-only controls was extended up to 59 days. A single exposure of animals to VVR-2721 did not affect the cumulative survival curves for unirradiated mice. WR-2721 possesses chemopreventive properties which can be clinically exploited to reduce the risk to therapy-induced secondary cancers in patients who otherwise would have an excellent prognosis for cure and long-term survival.

  7. 76 FR 50164 - Protocol Gas Verification Program and Minimum Competency Requirements for Air Emission Testing...

    Science.gov (United States)

    2011-08-12

    ... AGENCY 40 CFR Parts 72 and 75 RIN 2060-AQ06 Protocol Gas Verification Program and Minimum Competency... Program and Minimum Competency Requirements for Air Emission Testing rule. EPA published in the Federal... Program (PGVP) and the minimum competency requirements for Air Emission Testing Bodies (AETBs), and...

  8. Improving the AODV Protocol to Satisfy the Required Level of Reliability for Home Area Networks

    Directory of Open Access Journals (Sweden)

    Hossein Jafari Pozveh

    2016-06-01

    Full Text Available For decades, the structure of existing power grids has not changed. It is an old structure that depends heavily on fossil fuel as an energy source, and in the future, this is likely to be critical in the field of energy. To solve these problems and to make optimal use of energy resources, a new concept is proposed, called Smart Grid. Smart Grid is an electric power distribution automation system, which can provide a two-way flow of electricity and information between power plants and consumers. The Smart Grid communications infrastructure consists of different network components, such as Home Area Network (HAN, Neighborhood Area Network (NAN and Wide Area Network (WAN. Achieving the required level of reliability in the transmission of information to all sections, including the HAN, is one of the main objectives in the design and implementation of Smart Grid. This study offers a routing protocol by considering the parameters and constraints of HAN, which, by improving AODV routing protocol, achieves the level of required reliability for data transmission in this network. These improvements include: making table-driven AODV routing protocol, extending the routing protocol to compute multiple paths in a route discovery, simplification and providing the effect of HAN parameters. The results of the NS2 simulation indicate that applying this improved routing protocol in the HAN, satisfies the required level of reliability of the network, which is over 98%.

  9. 76 FR 20536 - Protocol Gas Verification Program and Minimum Competency Requirements for Air Emission Testing

    Science.gov (United States)

    2011-04-13

    ... From the Federal Register Online via the Government Publishing Office ENVIRONMENTAL PROTECTION AGENCY 40 CFR Part 75 RIN 2060-AQ06 Protocol Gas Verification Program and Minimum Competency Requirements for Air Emission Testing Correction In rule document 2011-6216 appearing on pages 17288-17325 in...

  10. 76 FR 50129 - Protocol Gas Verification Program and Minimum Competency Requirements for Air Emission Testing...

    Science.gov (United States)

    2011-08-12

    ... From the Federal Register Online via the Government Publishing Office ENVIRONMENTAL PROTECTION AGENCY 40 CFR Parts 72 and 75 RIN 2060-AQ06 Protocol Gas Verification Program and Minimum Competency... Verification Program and Minimum Competency Requirements for Air Emission Testing final rule, which...

  11. INTEGRATED DATA CAPTURING REQUIREMENTS FOR 3D SEMANTIC MODELLING OF CULTURAL HERITAGE: THE INCEPTION PROTOCOL

    Directory of Open Access Journals (Sweden)

    R. Di Giulio

    2017-02-01

    In order to face these challenges and to start solving the issue of the large amount of captured data and time-consuming processes in the production of 3D digital models, an Optimized Data Acquisition Protocol (DAP has been set up. The purpose is to guide the processes of digitization of cultural heritage, respecting needs, requirements and specificities of cultural assets.

  12. Current status of oral cancer chemoprevention

    Institute of Scientific and Technical Information of China (English)

    Moni Abraham Kuriakose

    2008-01-01

    @@ Chemoprevention is the administration of agents to block or reverse carcinogenesis. Chemoprevention in oral cancer has been directed towards reversal of premalignant lesion and prevention of second primary tumor.

  13. Moringa oleifera Lam: Targeting Chemoprevention.

    Science.gov (United States)

    Karim, Nurul Ashikin Abd; Ibrahim, Muhammad Din; Kntayya, Saie Brindha; Rukayadi, Yaya; Hamid, Hazrulizawati Abd; Razis, Ahmad Faizal Abdull

    2016-01-01

    Moringa oleifera Lam, family Moringaceae, is a perennial plant which is called various names, but is locally known in Malaysia as "murungai" or "kelor". Glucomoringin, a glucosinolate with from M. oleifera is a major secondary metabolite compound. The seeds and leaves of the plant are reported to have the highest amount of glucosinolates. M. oleifera is well known for its many uses health and benefits. It is claimed to have nutritional, medicinal and chemopreventive potentials. Chemopreventive effects of M. oleifera are expected due to the existence of glucosinolate which it is reported to have the ability to induce apoptosis in anticancer studies. Furthermore, chemopreventive value of M. oleifera has been demonstrated in studies utilizing its leaf extract to inhibit the growth of human cancer cell lines. This review highlights the advantages of M. oleifera targeting chemoprevention where glucosinolates could help to slow the process of carcinogenesis through several molecular targets. It is also includes inhibition of carcinogen activation and induction of carcinogen detoxification, anti-inflammatory, anti-tumor cell proliferation, induction of apoptosis and inhibition of tumor angiogenesis. Finally, for synergistic effects of M. oleifera with other drugs and safety, essential for chemoprevention, it is important that it safe to be consumed by human body and works well. Although there is promising evidence about M. oleifera in chemoprevention, extensive research needs to be done due to the expected rise of cancer in coming years and to gain more information about the mechanisms involved in M. oleifera influence, which could be a good source to inhibit several major mechanisms involved in cancer development.

  14. Protocol Requirements for Self-organizing Artifacts: Towards an Ambient Intelligence

    Science.gov (United States)

    Gershenson, Carlos; Heylighen, Francis

    We discuss1 which properties common-use artifacts should have to collaborate without human intervention. We conceive how devices, such as mobile phones, PDAs, and home appliances, could be seamlessly integrated to provide an "ambient intelligence" that responds to the user's desires without requiring explicit programming or commands. While the hardware and software technology to build such systems already exists, as yet there is no standard protocol that can learn new meanings. We propose the first steps in the development of such a protocol, which would need to be adaptive, extensible, and open to the community, while promoting self-organization. We argue that devices, interacting through "game-like" moves, can learn to agree about how to communicate, with whom to cooperate, and how to delegate and coordinate specialized tasks. Thus, they may evolve a distributed cognition or collective intelligence capable of tackling complex tasks.

  15. Nicotinamide for skin cancer chemoprevention.

    Science.gov (United States)

    Damian, Diona L

    2017-03-20

    Nicotinamide (vitamin B3 ) has a range of photoprotective effects in vitro and in vivo; it enhances DNA repair, reduces UV radiation-induced suppression of skin immune responses, modulates inflammatory cytokine production and skin barrier function and restores cellular energy levels after UV exposure. Pharmacological doses of nicotinamide have been shown to reduce actinic keratoses and nonmelanoma skin cancer incidence in high-risk individuals, making this a nontoxic and accessible option for skin cancer chemoprevention in this population.

  16. Comet Assay in Cancer Chemoprevention.

    Science.gov (United States)

    Santoro, Raffaela; Ferraiuolo, Maria; Morgano, Gian Paolo; Muti, Paola; Strano, Sabrina

    2016-01-01

    The comet assay can be useful in monitoring DNA damage in single cells caused by exposure to genotoxic agents, such as those causing air, water, and soil pollution (e.g., pesticides, dioxins, electromagnetic fields) and chemo- and radiotherapy in cancer patients, or in the assessment of genoprotective effects of chemopreventive molecules. Therefore, it has particular importance in the fields of pharmacology and toxicology, and in both environmental and human biomonitoring. It allows the detection of single strand breaks as well as double-strand breaks and can be used in both normal and cancer cells. Here we describe the alkali method for comet assay, which allows to detect both single- and double-strand DNA breaks.

  17. Integrated Data Capturing Requirements for 3d Semantic Modelling of Cultural Heritage: the Inception Protocol

    Science.gov (United States)

    Di Giulio, R.; Maietti, F.; Piaia, E.; Medici, M.; Ferrari, F.; Turillazzi, B.

    2017-02-01

    The generation of high quality 3D models can be still very time-consuming and expensive, and the outcome of digital reconstructions is frequently provided in formats that are not interoperable, and therefore cannot be easily accessed. This challenge is even more crucial for complex architectures and large heritage sites, which involve a large amount of data to be acquired, managed and enriched by metadata. In this framework, the ongoing EU funded project INCEPTION - Inclusive Cultural Heritage in Europe through 3D semantic modelling proposes a workflow aimed at the achievements of efficient 3D digitization methods, post-processing tools for an enriched semantic modelling, web-based solutions and applications to ensure a wide access to experts and non-experts. In order to face these challenges and to start solving the issue of the large amount of captured data and time-consuming processes in the production of 3D digital models, an Optimized Data Acquisition Protocol (DAP) has been set up. The purpose is to guide the processes of digitization of cultural heritage, respecting needs, requirements and specificities of cultural assets.

  18. Validating Vegetable Production Unit (VPU) Plants, Protocols, Procedures and Requirements (P3R) using Currently Existing Flight Resources

    Science.gov (United States)

    Bingham, Gail; Bates, Scott; Bugbee, Bruce; Garland, Jay; Podolski, Igor; Levinskikh, Rita; Sychev, Vladimir; Gushin, Vadim

    2009-01-01

    Validating Vegetable Production Unit (VPU) Plants, Protocols, Procedures and Requirements (P3R) Using Currently Existing Flight Resources (Lada-VPU-P3R) is a study to advance the technology required for plant growth in microgravity and to research related food safety issues. Lada-VPU-P3R also investigates the non-nutritional value to the flight crew of developing plants on-orbit. The Lada-VPU-P3R uses the Lada hardware on the ISS and falls under a cooperative agreement between National Aeronautics and Space Administration (NASA) and the Russian Federal Space Association (FSA). Research Summary: Validating Vegetable Production Unit (VPU) Plants, Protocols, Procedures and Requirements (P3R) Using Currently Existing Flight Resources (Lada-VPU-P3R) will optimize hardware and

  19. A Rover Operations Protocol for Maintaining Compliance with Planetary Protection Requirements

    Science.gov (United States)

    Jones, Melissa; Vasavada, Ashwin

    2016-07-01

    The Mars Science Laboratory (MSL) mission, with its Curiosity rover, arrived at Gale Crater in August 2012 with the scientific objective of assessing the past and present habitability of the landing site area. It is not a life detection mission, but one that uses geological, geochemical, and environmental measurements to understand whether past and present conditions could have supported life. The MSL mission is designated Planetary Protection Category IVa, with specific restrictions on the landing site and surface operations. In particular, the mission is prohibited from introducing any hardware into a Mars Special Region, as defined by COSPAR policy and in NASA document NPR 8020.12D. Fluid-formed features such as recurring slope lineae are included in this prohibition. Finally, any evidence suggesting the presence of Special Regions or flowing liquid at the actual MSL landing site shall be communicated to the NASA Planetary Protection Officer immediately, and physical contact by the rover with such features shall be entirely avoided. The MSL Project has recently developed and instituted a protocol in daily rover operations to ensure ongoing compliance with its planetary protection categorization. A particular challenge comes from the fact that the characteristics of potential Special Regions may not be obvious in the rover downlink data (e.g., landscape images, chemical measurements, or meteorology), or easily distinguishable from characteristics of other processes that do not imply Special Regions. For this reason, the first step in the process would be for the lead scientist for that day of operations (a role that rotates through senior scientists on the mission) to scrutinize all the targets that may receive interaction by rover hardware, such as targets for arm contact, or paths for wheel contact. Based on the expertise of the lead scientist, and definitions of Mars Special Regions, if any features of concern are identified, the other scientists on duty that

  20. Ellagitannins in Cancer Chemoprevention and Therapy

    Directory of Open Access Journals (Sweden)

    Tariq Ismail

    2016-05-01

    Full Text Available It is universally accepted that diets rich in fruit and vegetables lead to reduction in the risk of common forms of cancer and are useful in cancer prevention. Indeed edible vegetables and fruits contain a wide variety of phytochemicals with proven antioxidant, anti-carcinogenic, and chemopreventive activity; moreover, some of these phytochemicals also display direct antiproliferative activity towards tumor cells, with the additional advantage of high tolerability and low toxicity. The most important dietary phytochemicals are isothiocyanates, ellagitannins (ET, polyphenols, indoles, flavonoids, retinoids, tocopherols. Among this very wide panel of compounds, ET represent an important class of phytochemicals which are being increasingly investigated for their chemopreventive and anticancer activities. This article reviews the chemistry, the dietary sources, the pharmacokinetics, the evidence on chemopreventive efficacy and the anticancer activity of ET with regard to the most sensitive tumors, as well as the mechanisms underlying their clinically-valuable properties.

  1. Polyphenols as cancer chemopreventive agents.

    Science.gov (United States)

    Stoner, G D; Mukhtar, H

    1995-01-01

    This article summarizes available data on the chemopreventive efficacies of tea polyphenols, curcumin and ellagic acid in various model systems. Emphasis is placed upon the anticarcinogenic activity of these polyphenols and their proposed mechanism(s) of action. Tea is grown in about 30 countries and, next to water, is the most widely consumed beverage in the world. Tea is manufactured as either green, black, or oolong; black tea represents approximately 80% of tea products. Epidemiological studies, though inconclusive, suggest a protective effect of tea consumption on human cancer. Experimental studies of the antimutagenic and anticarcinogenic effects of tea have been conducted principally with green tea polyphenols (GTPs). GTPs exhibit antimutagenic activity in vitro, and they inhibit carcinogen-induced skin, lung, forestomach, esophagus, duodenum and colon tumors in rodents. In addition, GTPs inhibit TPA-induced skin tumor promotion in mice. Although several GTPs possess anticarcinogenic activity, the most active is (-)-epigallocatechin-3-gallate (EGCG), the major constituent in the GTP fraction. Several mechanisms appear to be responsible for the tumor-inhibitory properties of GTPs, including enhancement of antioxidant (glutathione peroxidase, catalase and quinone reductase) and phase II (glutathione-S-transferase) enzyme activities; inhibition of chemically induced lipid peroxidation; inhibition of irradiation- and TPA-induced epidermal ornithine decarboxylase (ODC) and cyclooxygenase activities; inhibition of protein kinase C and cellular proliferation; antiinflammatory activity; and enhancement of gap junction intercellular communication. Curcumin is the yellow coloring agent in the spice tumeric. It exhibits antimutagenic activity in the Ames Salmonella test and has anticarcinogenic activity, inhibiting chemically induced preneoplastic lesions in the breast and colon and neoplastic lesions in the skin, forestomach, duodenum and colon of rodents. In addition

  2. The application of Kyoto Protocol in Italy: role and required synergies between central and regional administrations

    Directory of Open Access Journals (Sweden)

    Pilli R

    2007-01-01

    Full Text Available According to art. 3.3 of the Kyoto Protocol, Parties included in Annex I shall report the net changes in greenhouse gas emissions by sources and removals by sinks resulting from afforestation, reforestation and deforestation activities. To assess these activities, Italy has to define methods to estimate land use change occurring after 31 December 1989. On the other hand, Italy elected forest management as additional human-induced activity to attain the goals of reduction of greenhouse gas emissions. The paper considers the key-role that central and regional Administrations may have in order to solve some specific problems regarding data collection and management issues.

  3. Beneficial and adverse effects of chemopreventive agents

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Byung Mu; Park, Kwang-Kyun

    2003-03-01

    The beneficial and adverse effects of some chemopreventive agents, such as Vitamins A, C, E, beta-carotene, indole-3-carbinol, capsaicin, garlic, and aloe are reviewed. Two large randomized trials with a lung cancer endpoint, the Alpha-Tocopherol, Beta-Carotene (ATBC) Prevention Study and the Beta-Carotene and Retinol Efficacy Trial (CARET), suggested that antioxidants might be harmful in smokers. However, the results of the Linxian study and of the ATBC or the CARET studies were significantly different in this respect, and therefore, the relationship between antioxidant and carcinogenesis remains open to debate. Indole-3-carbinol has cancer promoting activities in the colon, thyroid, pancreas, and liver, whereas capsaicin alters the metabolism of chemical carcinogens and may promote carcinogenesis at high doses. Organosulfur compounds and selenium from garlic have no or a little enhancing effect on cancer promotion stage. Information upon chemopreventive mechanisms that inhibit carcinogenesis is imperfect, although the causes and natures of certain human cancers are known. Therefore, definitive preventive guidelines should be carefully offered for various types of tumors, which properly consider ethnic variations, and the efficacies and the safety of chemopreventive agents.

  4. 75 FR 33391 - Amendments to the Protocol Gas Verification Program and Minimum Competency Requirements for Air...

    Science.gov (United States)

    2010-06-11

    ... testing (formerly air emission testing body requirements) to improve the accuracy of emissions data. EPA... left out of the January 24, 2008 final rule, and clarifying the language and applicability of certain..., which means EPA will not know your identity or contact information unless you provide it in the body...

  5. 21 CFR 320.30 - Inquiries regarding bioavailability and bioequivalence requirements and review of protocols by...

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 5 2010-04-01 2010-04-01 false Inquiries regarding bioavailability and... FOR HUMAN USE BIOAVAILABILITY AND BIOEQUIVALENCE REQUIREMENTS Procedures for Determining the Bioavailability or Bioequivalence of Drug Products § 320.30 Inquiries regarding bioavailability and...

  6. Analysis of Requirements for the Medication Profile to Be Used in Clinical Research: Protocol Feasibility Studies and Patient Recruitment

    Directory of Open Access Journals (Sweden)

    Julie M. James

    2015-01-01

    Full Text Available A “Medication Profile,” the information about the medicines a person is using and has used, is a core part of many electronic health record systems and summaries. However, there is little objective research into the data elements that the profile should contain to support the uses it must serve. With the increasing emphasis on secondary uses of electronic health information, as well as supporting the requirements to support direct to patient care, the Medication Profile should also support the requirements from clinical research. However, there is little, if any, description of these available. This paper describes an analysis of a set of study eligibility criteria that was undertaken to investigate which medication-related data elements would be required to support two clinical research use cases: the parameters to query a patient’s Medication Profile to assess their suitability for entry into a trial (patient recruitment and the parameters to query a set of Medication Profiles in a data warehouse to assess whether the eligibility criteria as described would yield a reasonable cohort of patients as potential subjects (protocol feasibility. These medication-related data elements then become information requirements that a Medication Profile should ideally meet, in order to be able to support these two uses in the clinical research domain.

  7. Chemopreventive potential of Annona muricata L leaves on chemically-induced skin papillomagenesis in mice.

    Science.gov (United States)

    Hamizah, Sulaiman; Roslida, A H; Fezah, O; Tan, K L; Tor, Y S; Tan, C I

    2012-01-01

    Annona muricata L (Annonaceae), commonly known as soursop has a long, rich history in herbal medicine with a lengthy recorded indigenous use. It had also been found to be a promising new anti-tumor agent in numerous in vitro studies. The present investigation concerns chemopreventive effects in a two-stage model of skin papillomagenesis. Chemopreventive effects of an ethanolic extract of A. muricata leaves (AMLE) was evaluated in 6-7 week old ICR mice given a single topical application of 7,12-dimethylbenza(α)anthracene (DMBA 100 μg/100 μl acetone) and promotion by repeated application of croton oil (1% in acetone/ twice a week) for 10 weeks. Morphological tumor incidence, burden and volume were measured, with histological evaluation of skin tissue. Topical application of AMLE at 30, 100 and 300 mg/kg significantly reduced DMBA/croton oil induced mice skin papillomagenesis in (i) peri-initiation protocol (AMLE from 7 days prior to 7 days after DMBA), (ii) promotion protocol (AMLE 30 minutes after croton oil), or (iii) both peri-initiation and promotion protocol (AMLE 7 days prior to 7 day after DMBA and AMLE 30 minutes after croton oil throughout the experimental period), in a dose dependent manner (pmuricata leaves extract was able to suppress tumor initiation as well as tumor promotion even at lower dosage.

  8. Emerging Applications of Metabolomics in Studying Chemopreventive Phytochemicals

    OpenAIRE

    2013-01-01

    Phytochemicals from diet and herbal medicines are under intensive investigation for their potential use as chemopreventive agents to block and suppress carcinogenesis. Chemical diversity of phytochemicals, together with complex metabolic interactions between phytochemicals and biological system, can overwhelm the capacity of traditional analytical platforms, and thus pose major challenges in studying chemopreventive phytochemicals. Recent progresses in metabolomics have transformed it to beco...

  9. Retinoids in lung cancer chemoprevention and treatment.

    Science.gov (United States)

    Toma, S; Raffo, P; Isnardi, L; Palumbo, R

    1999-01-01

    In this review, we aim to synthesize the emerging picture of retinoids in lung cancer through a summary of ongoing investigations in biology, chemoprevention and therapy settings, in an attempt to clarify the possible role of these agents in such a disease. Early work in head and neck cancer has evidenced the capability of retinoids to interrupt field carcinogenesis by reversing premalignant lesions and decreasing the incidence of second primary tumors (SPTs). At this time, the completed randomized trials in lung cancer have failed to demonstrate an evident chemopreventive effect of the tested agents on different study end points, although both a marginally significant benefit of retinol palmitate in time-to-development rates for smoke-related SPTs and a potential preventive effect of retinol supplementation against mesothelioma in selected populations of asbestos-exposed workers have been recently reported. Concerning the role of retinoids in lung cancer treatment, a moderate activity of 13-cis-retinoic acid (13cRA) or all-transretinoic acid (ATRA) as single agents has been reported in small series of advanced, mostly pretreated lung cancer patients. More encouraging findings derive from combination studies, in which retinoids, especially ATRA, are added to either alpha-interferon or chemotherapy and radiotherapy. Major recent advances have been made towards the understanding of retinoids mechanisms of action; at this regard, the role of RAR-beta basal or treatment-induced levels seems to be of particular interest as intermediate end point and/or independent prognostic factor, besides their known importance in lung carcinogenesis. Future research for chemopreventive and therapeutic programs with retinoids in lung cancer should be focused on the investigation of new generation compounds with a specificity for individual retinoid nuclear receptors. Such selective molecules may have a greater activity against lung cancer, with a more favourable toxicity profile, as

  10. [Colorectal adenomas: postpolypectomy surveillance strategies and chemoprevention].

    Science.gov (United States)

    Castells, Antoni

    2008-10-01

    Colorectal adenomas are the most fully characterized premalignant lesions in the development of colorectal cancer. Consequently, the identification and resolution of these lesions, as well as the follow-up of affected patients, are a priority in the prevention of this neoplasm. The studies presented in the annual meeting of the American Gastroenterological Association 2008 show that the results of current surveillance strategies can be improved with a view to reducing the rate of interval neoplasia. Improvement of these results includes optimization of the endoscopic technique (colonic preparation, cecal intubation, withdrawal time, etc.) as well as the incorporation of new diagnostic methods and the possible administration of chemopreventive drugs.

  11. Sports-related testing protocols are required to reveal trunk stability adaptations in high-level athletes.

    Science.gov (United States)

    Barbado, David; Barbado, Luis C; Elvira, Jose L L; Dieën, Jaap H van; Vera-Garcia, Francisco J

    2016-09-01

    Trunk/core stability is considered a key component of training programs, because it could contribute to prevention of low-back and lower-limb injuries and to sports performance. Based on the specificity principle, sports-related trunk stability tests would be required in elite sports performance. However, there may be some generic qualities underlying trunk stability that can be assessed with nonspecific protocols, which are broadly used in sport and rehabilitation. To assess whether specific tests are needed in a high-performance context, we analyzed the influence of specialization in sports with large but qualitatively different balance control demands (judo and kayaking) on trunk stability and compared high-performance athletes with recreational athletes without a specific training history. Twenty-five judokas, sixteen kayakers and thirty-seven recreational athletes performed two trunk stability protocols: sudden loading, to assess trunk responses to external and unexpected perturbations; stable and unstable sitting, to assess the participant's ability to control trunk while sitting. Within-session test-retest reliability analyses were performed to support the between-groups comparison. Judokas showed lower angular displacement (0.199rad) against posterior loading than kayakers (0.221rad) probably because they are frequently challenged by higher sudden loads while they are pushed or pulled. Kayakers showed lower error (7.33mm), probably because they train and compete seated on unstable surfaces. Importantly, judokas and kayakers obtained better results than recreational athletes only in those tests designed according to the specific demands of each sport (psport training induces specific trunk stability adaptations, which are not revealed through nonspecific tests.

  12. Cancer Chemopreventive Ability of Conjugated Linolenic Acids

    Directory of Open Access Journals (Sweden)

    Kazuo Miyashita

    2011-11-01

    Full Text Available Conjugated fatty acids (CFA have received increased interest because of their beneficial effects on human health, including preventing cancer development. Conjugated linoleic acids (CLA are such CFA, and have been reviewed extensively for their multiple biological activities. In contrast to other types of CFAs including CLA that are found at low concentrations (less than 1% in natural products, conjugated linolenic acids (CLN are the only CFAs that occur in higher quantities in natural products. Some plant seeds contain a considerably high concentration of CLN (30 to 70 wt% lipid. Our research group has screened CLN from different plant seed oils to determine their cancer chemopreventive ability. This review describes the physiological functions of CLN isomers that occur in certain plant seeds. CLN are able to induce apoptosis through decrease of Bcl-2 protein in certain human cancer cell lines, increase expression of peroxisome proliferator-activated receptor (PPAR-γ, and up-regulate gene expression of p53. Findings in our preclinical animal studies have indicated that feeding with CLN resulted in inhibition of colorectal tumorigenesis through modulation of apoptosis and expression of PPARγ and p53. In this review, we summarize chemopreventive efficacy of CLN against cancer development, especially colorectal cancer.

  13. Chemoprevention of lung cancer by tea.

    Science.gov (United States)

    Clark, Julie; You, Ming

    2006-02-01

    Tea is the second only to water as the most consumed beverage in the world. Both green and black teas have been studied for their health benefits for a variety of diseases, particularly cancer. Lung cancer is the predominant cause of cancer mortality in developed countries. Smokers' risk of lung cancer is 20 times that of persons who have never smoked. Epidemiological studies on the cancer-preventive effects of tea produce inconsistent results, which could in part be attributed to the lack of a universal standard for tea preparations. However, most animal studies indicate that tea has strong chemopreventive effects against lung tumorigenesis. The reported mechanisms for chemopreventive activity of green tea are antioxidation, induction of phase II enzymes, inhibition of TNFalpha expression and release, inhibition of cell proliferation, and induction of apoptosis. Cell cycle arrest and apoptosis induced by green tea are probably the two most significant factors. Future studies are needed to determine how green tea affects the genes associated with cell cycle regulation and apoptosis during the mouse lung carcinogenesis process.

  14. Chemoprevention in gastrointestinal physiology and disease. Anti-inflammatory approaches for colorectal cancer chemoprevention

    Science.gov (United States)

    Piazza, Gary A.

    2015-01-01

    Colorectal cancer (CRC) is one of the most common human malignancies and a leading cause of cancer-related deaths in developed countries. Identifying effective preventive strategies aimed at inhibiting the development and progression of CRC is critical for reducing the incidence and mortality of this malignancy. The prevention of carcinogenesis by anti-inflammatory agents including nonsteroidal anti-inflammatory drugs (NSAIDs), selective cyclooxygenase-2 (COX-2) inhibitors, and natural products is an area of considerable interest and research. Numerous anti-inflammatory agents have been identified as potential CRC chemopreventive agents but vary in their mechanism of action. This review will discuss the molecular mechanisms being studied for the CRC chemopreventive activity of NSAIDs (i.e., aspirin, sulindac, and ibuprofen), COX-2 inhibitors (i.e., celecoxib), natural products (i.e., curcumin, resveratrol, EGCG, genistein, and baicalein), and metformin. A deeper understanding of how these anti-inflammatory agents inhibit CRC will provide insight into the development of potentially safer and more effective chemopreventive drugs. PMID:26021807

  15. Polyamine catabolism in carcinogenesis: potential targets for chemotherapy and chemoprevention.

    Science.gov (United States)

    Battaglia, Valentina; DeStefano Shields, Christina; Murray-Stewart, Tracy; Casero, Robert A

    2014-03-01

    Polyamines, including spermine, spermidine, and the precursor diamine, putrescine, are naturally occurring polycationic alkylamines that are required for eukaryotic cell growth, differentiation, and survival. This absolute requirement for polyamines and the need to maintain intracellular levels within specific ranges require a highly regulated metabolic pathway primed for rapid changes in response to cellular growth signals, environmental changes, and stress. Although the polyamine metabolic pathway is strictly regulated in normal cells, dysregulation of polyamine metabolism is a frequent event in cancer. Recent studies suggest that the polyamine catabolic pathway may be involved in the etiology of some epithelial cancers. The catabolism of spermine to spermidine utilizes either the one-step enzymatic reaction of spermine oxidase (SMO) or the two-step process of spermidine/spermine N (1)-acetyltransferase (SSAT) coupled with the peroxisomal enzyme N (1)-acetylpolyamine oxidase. Both catabolic pathways produce hydrogen peroxide and a reactive aldehyde that are capable of damaging DNA and other critical cellular components. The catabolic pathway also depletes the intracellular concentrations of spermidine and spermine, which are free radical scavengers. Consequently, the polyamine catabolic pathway in general and specifically SMO and SSAT provide exciting new targets for chemoprevention and/or chemotherapy.

  16. The Use of Animal Models for Cancer Chemoprevention Drug Development

    OpenAIRE

    2010-01-01

    Animal models currently are used to assess the efficacy of potential chemopreventive agents, including synthetic chemicals, chemical agents obtained from natural products and natural product mixtures. The observations made in these models as well as other data are then used to prioritize agents to determine which are qualified to progress to clinical chemoprevention trials. Organ specific animal models are employed to determine which agents or classes of agents are likely to be the most effec...

  17. Capsaicin: A novel chemopreventive molecule and its underlying molecular mechanisms of action

    Directory of Open Access Journals (Sweden)

    A A Oyagbemi

    2010-01-01

    Full Text Available Capsaicin (trans-8-methyl-N-vanillyl-6-nonenamide is the a principal pungent ingredient of hot red and chili peppers that belong to the plant genus Capsicum (Solanaceae. Capsaicin is a cancer-suppressing agent. It blocks the translocation of nuclear factor kappa B (NF-kB, activator protein 1 (AP-1, and signal transducer and activator of transcription (STAT3 signaling pathway that are required for carcinogenesis. The anti-inflammatory potential of capsaicin is attributed to its inhibitory effect on inducible COX-2 mRNA expression. Cytochrome P4502E1 mediates the activation of xenobiotics such as vinyl carbamate and dimethyl nitrosamine to their toxic metabolites. This metabolic activation of xenobiotics by Cytochrome P4502E1 has been shown to be inhibited by capsaicin. Capsaicin also generates reactive oxygen species in cells with resultant induction of apoptosis and cell cycle arrest, which is beneficial for cancer chemoprevention. Therefore, the use of capsaicin as a chemopreventive agent is of immense benefit for cancer chemoprevention. The search strategy included printed journals, pubmed, and medline, using the terms ′capsaicin′ and ′anticancer′ citations, relevant to anticancer properties of capsaicin.

  18. Polyamines and cancer: implications for chemotherapy and chemoprevention.

    Science.gov (United States)

    Nowotarski, Shannon L; Woster, Patrick M; Casero, Robert A

    2013-02-22

    Polyamines are small organic cations that are essential for normal cell growth and development in eukaryotes. Under normal physiological conditions, intracellular polyamine concentrations are tightly regulated through a dynamic network of biosynthetic and catabolic enzymes, and a poorly characterised transport system. This precise regulation ensures that the intracellular concentration of polyamines is maintained within strictly controlled limits. It has frequently been observed that the metabolism of, and the requirement for, polyamines in tumours is frequently dysregulated. Elevated levels of polyamines have been associated with breast, colon, lung, prostate and skin cancers, and altered levels of rate-limiting enzymes in both biosynthesis and catabolism have been observed. Based on these observations and the absolute requirement for polyamines in tumour growth, the polyamine pathway is a rational target for chemoprevention and chemotherapeutics. Here we describe the recent advances made in the polyamine field and focus on the roles of polyamines and polyamine metabolism in neoplasia through a discussion of the current animal models for the polyamine pathway, chemotherapeutic strategies that target the polyamine pathway, chemotherapeutic clinical trials for polyamine pathway-specific drugs and ongoing clinical trials targeting polyamine biosynthesis.

  19. Polyamines and cancer: Implications for chemoprevention and chemotherapy

    Science.gov (United States)

    Nowotarski, Shannon L.; Woster, Patrick M.; Casero, Robert A.

    2013-01-01

    Polyamines are small organic cations that are essential for normal cell growth and development in eukaryotes. Under normal physiological conditions, intracellular polyamine concentrations are tightly regulated through a dynamic network of biosynthetic and catabolic enzymes and a poorly characterized transport system. This precise regulation ensures that the intracellular concentration of polyamines is maintained within strictly controlled limits. It has frequently been observed that the metabolism of, and the requirement for, polyamines in tumours is frequently dysregulated. Elevated levels of polyamines have been associated with breast, colon, lung, prostate, and skin cancers, and altered levels of the rate limiting enzymes in both biosynthesis and catabolism have been observed. Based on these observations and the absolute requirement for polyamines in tumour growth, the polyamine pathway is a rational target for chemoprevention and chemotherapeutics. Here we describe the recent advances made in the polyamine field and focus on the roles of polyamines and polyamine metabolism in neoplasia through a discussion of the current animal models for the polyamine pathway, chemotherapeutic strategies that target the polyamine pathway, chemotherapeutic clinical trials for polyamine pathway specific drugs, and ongoing clinical trials targeting polyamine biosynthesis. PMID:23432971

  20. Endotoxin and cancer chemo-prevention.

    Science.gov (United States)

    Mastrangelo, Giuseppe; Fadda, Emanuela; Cegolon, Luca

    2013-10-01

    Reduced rates of lung cancer have been observed in several occupational groups exposed to high levels of organic dusts contaminated by endotoxin. The underlying anti-neoplastic mechanism of endotoxin may be an increased secretion of endogenous anti-neoplastic mediators and activation of the toll-like receptors (TLR). A detoxified endotoxin derivative, Monophosphoryl Lipid A (MPL(®)) is marketed in Europe since 1999 as part of the adjuvant systems in allergy vaccines for treatment of allergic rhino-conjunctivitis and allergic asthma. Over 200,000 patients have used them to date (nearly 70% in Germany). Since detailed exposure (MPL(®) dose and timing of administration) and individual data are potentially available, an observational follow-up study could be conducted in Germany to investigate the protective effect of MPL(®) against cancer, comparing cancer incidence in two groups of patients with allergic rhinitis: those treated with allergoids plus MPL(®) and those treated with a vaccine including the same allergoids but not MPL(®). The protective effect of MPL(®) could be quantified in ever and never smokers. If this proposed observational study provides evidence of protective effects, MPL(®) could be immediately used as a chemo-preventive agent since it is already in use as adjuvant in human vaccines against cancer.

  1. Proposed Requirements-driven User-scenario Development Protocol for the Belmont Forum E-Infrastructure and Data Management Cooperative Research Agreement

    Science.gov (United States)

    Wee, B.; Car, N.; Percivall, G.; Allen, D.; Fitch, P. G.; Baumann, P.; Waldmann, H. C.

    2014-12-01

    The Belmont Forum E-Infrastructure and Data Management Cooperative Research Agreement (CRA) is designed to foster a global community to collaborate on e-infrastructure challenges. One of the deliverables is an implementation plan to address global data infrastructure interoperability challenges and align existing domestic and international capabilities. Work package three (WP3) of the CRA focuses on the harmonization of global data infrastructure for sharing environmental data. One of the subtasks under WP3 is the development of user scenarios that guide the development of applicable deliverables. This paper describes the proposed protocol for user scenario development. It enables the solicitation of user scenarios from a broad constituency, and exposes the mechanisms by which those solicitations are evaluated against requirements that map to the Belmont Challenge. The underlying principle of traceability forms the basis for a structured, requirements-driven approach resulting in work products amenable to trade-off analyses and objective prioritization. The protocol adopts the ISO Reference Model for Open Distributed Processing (RM-ODP) as a top level framework. User scenarios are developed within RM-ODP's "Enterprise Viewpoint". To harmonize with existing frameworks, the protocol utilizes the conceptual constructs of "scenarios", "use cases", "use case categories", and use case templates as adopted by recent GEOSS Architecture Implementation Project (AIP) deliverables and CSIRO's eReefs project. These constructs are encapsulated under the larger construct of "user scenarios". Once user scenarios are ranked by goodness-of-fit to the Belmont Challenge, secondary scoring metrics may be generated, like goodness-of-fit to FutureEarth science themes. The protocol also facilitates an assessment of the ease of implementing given user scenario using existing GEOSS AIP deliverables. In summary, the protocol results in a traceability graph that can be extended to coordinate

  2. Chemoprevention of Radiation Induced Rat Mammary Neoplasms

    Science.gov (United States)

    Huso, David L.

    1999-01-01

    Radiations encountered in space include protons and heavy ions such as iron as well as their secondaries. The relative biological effect (RBE) of these ions is not known, particularly at the doses and dose-rates expected for planetary missions. Neutrons, are not particularly relevant to space travel, but have been found experimentally to have an increase in their RBE with decreasing dose. If a similar trend of increasing RBE with decreasing dose is present for heavy ions and protons during irradiation in space, the small doses received during space travel could potentially have substantial carcinogenic risk. Clearly more investigation of the effects of heavy ions and protons is needed before accurate risk assessment for prolonged travel in space can be done. One means to mitigate the increased risk of cancer due to radiation exposure in space is by developing effective countermeasures that can reduce the incidence of tumor development. Tamoxifen has recently been shown to be an effective chemopreventive agent in both animal models and humans for the prevention of mammary tumors. Tamoxifen is a unique drug, with a highly specific mechanism of action affecting a specific radiation-sensitive population of epithelial cells in the mammary gland. In human studies, the annual incidence of a primary tumor in the contralateral breast of women with previous breast cancer is about 8 per 1000, making them an exceedingly high-risk group for the development of breast cancer. In this high risk group, treated with tamoxifen, daily, for 2 years, the incidence of a new primary tumor in the contralateral breast was approximately one third of that noted in the non-tamoxifen treatment group. Tamoxifen antagonizes the action of estrogen by competing for the nuclear receptor complex thereby altering the association of the receptor complex and nuclear binding sites. Its effects in reducing the development of breast cancer could be accomplished by controlling clinically undetectable

  3. Emerging applications of metabolomics in studying chemopreventive phytochemicals.

    Science.gov (United States)

    Wang, Lei; Chen, Chi

    2013-10-01

    Phytochemicals from diet and herbal medicines are under intensive investigation for their potential use as chemopreventive agents to block and suppress carcinogenesis. Chemical diversity of phytochemicals, together with complex metabolic interactions between phytochemicals and biological system, can overwhelm the capacity of traditional analytical platforms, and thus pose major challenges in studying chemopreventive phytochemicals. Recent progresses in metabolomics have transformed it to become a robust systems biology tool, suitable for examining both chemical and biochemical events that contribute to the cancer prevention activities of plant preparations or their bioactive components. This review aims to discuss the technical platform of metabolomics and its existing and potential applications in chemoprevention research, including identifying bioactive phytochemicals in plant extracts, monitoring phytochemical exposure in humans, elucidating biotransformation pathways of phytochemicals, and characterizing the effects of phytochemicals on endogenous metabolism and cancer metabolism.

  4. Molecular Mechanisms Behind the Chemopreventive Effects of Anthocyanidins

    Directory of Open Access Journals (Sweden)

    De-Xing Hou

    2004-01-01

    Full Text Available Anthocyanins are polyphenolic ring-based flavonoids, and are widespread in fruits and vegetables of red-blue color. Epidemiological investigations and animal experiments have indicated that anthocyanins may contribute to cancer chemoprevention. The studies on the mechanism have been done recently at molecular level. This review summarizes current molecular bases for anthocyanidins on several key steps involved in cancer chemoprevention: (i inhibition of anthocyanidins in cell transformation through targeting mitogen-activated protein kinase (MAPK pathway and activator protein 1 (AP-1 factor; (ii suppression of anthocyanidins in inflammation and carcinogenesis through targeting nuclear factor kappa B (NF-κB pathway and cyclooxygenase 2 (COX-2 gene; (iii apoptotic induction of cancer cells by anthocyanidins through reactive oxygen species (ROS / c-Jun NH2-terminal kinase (JNK-mediated caspase activation. These data provide a first molecular view of anthocyanidins contributing to cancer chemoprevention.

  5. Identifying Molecular Targets for Chemoprevention in a Rat Model

    Science.gov (United States)

    2007-06-01

    were incubated in 10mMcitrate at 100jC. Primary antibodies were incubated overnight at room temperature in phosphate- buffered saline. We used the...Murakoshi M, Nishino H, and Shirai T (2001). Lack of chemopreventive effects of lycopene and curcumin on experimental rat prostate carci- nogenesis

  6. Keap1 eye on the target: chemoprevention of liver cancer

    Institute of Scientific and Technical Information of China (English)

    Melinda Sue YATES; Thomas Wells KENSLER

    2007-01-01

    Hepatocellular carcinoma (HCC) is one of the most common cancers worldwide,causing nearly 600000 deaths each year. Increased risk of HCC due to chronic infection with hepatitis B virus (HBV) and exposure to dietary aflatoxins is respon-sible for many of these deaths. Prevention strategies targeting HBV infection and aflatoxin exposure could dramatically impact the rates of HCC. Universal HBV vaccination programs have begun in some high-risk areas. Strategies to reduce aflatoxin contamination in food stores have also been implemented. However,complete elimination of aflatoxin contamination might not be possible. For this reason, chemoprevention strategies which alter aflatoxin disposition are a practi-cal strategy to reduce the incidence of HCC in populations with high dietary aflatoxin exposure. The mechanisms of aflatoxin-induced hepatocarcinogenesis are well known. This knowledge provides the basis for evaluation of both expo-sures to aflatoxin, as well as modulation of aflatoxin disposition by chemopreventive agents. Products of aflatoxin DNA damage and toxicity as well as other metabo-lites can be used as biomarkers to evaluate modulation of aflatoxin disposition.Modulation of aflatoxin disposition can be achieved through induction of conju-gating and cytoprotective enzymes. Many of these enzymes are regulated through Kelch ECH-associating protein 1 (Keap 1)-NF-E2-related factor 2(Nrf2)-antioxi-dant response element (ARE) signaling, making this pathway an important mo-lecular target for chemoprevention. Rodent studies have identified several classes of chemopreventive agents which induce cytoprotective genes. These inducers include phenolic antioxidants, dithiolethiones, isothiocyanates, and triterpenoids.Furthermore, clinical interventions have shown that inducers of Keap 1-Nrf2-ARE signaling increase cytoprotective enzyme expression, resulting in modula-tion of aflatoxin disposition. Much work remains to be done in order to take promising chemopreventive

  7. Chemoprevention of prostate cancer with nutrients and supplements

    Directory of Open Access Journals (Sweden)

    Van Poppel H

    2011-04-01

    Full Text Available Hendrik Van Poppel1, Bertrand Tombal21Department of Urology, University Hospital, KU Leuven, Leuven, Belgium; 2Service d’Urologie, Cliniques Universtaires Saint Luc, Brussels, BelgiumAbstract: As the adult population is increasing, prostate cancer (PCa will become a considerable health problem in the next millennium. This has raised public interest in potential chemoprevention of this disease. As PCa is extremely common and generally slow to progress it is regarded as an ideal candidate for chemoprevention. At present, the 5 alpha-reductase inhibitors finasteride and dutasteride have been identified as preventive agents. This review describes whether selenium, alpha-tocopherol, isoflavones, lycopene green tea polyphenols, calcium, and resveratrol may be useful for decreasing the risk of PCa in men. Although encouraging results are present, some studies show negative results. Differences in study design, sample size, dose administered, and/or concentrations achieved in the body may be the reason for these inconsistencies. Today, chemopreventive agents may be appropriate for high-risk patients like those with high-grade prostatic intraepithelial neoplasia and other high-risk groups such as patients with elevated prostate specific antigen (PSA and negative biopsy, rapid PSA velocity, and with a family history of PCa. Although larger randomized controlled studies are needed and epidemiologic evidence should be placed in a clinical context, physicians must be aware of these preventive opportunities in PCa care. Combinations of chemopreventive agents should be carefully investigated because mechanisms of action may be additive or synergistic.Keywords: alpha-tocopherol, chemoprevention, isoflavones, lycopene, polyphenols, prostate cancer, selenium

  8. Sugar-borate esters--potential chemical agents in prostate cancer chemoprevention.

    Science.gov (United States)

    Scorei, Romulus Ion; Popa, Radu

    2013-07-01

    The potential value of sugar-borate esters (SBEs) in the chemo-preventive therapy of prostate cancer has been reviewed. We propose that SBEs act as boron (B) vehicles, increasing the concentration of borate inside cancer cells relative to normal cells. Increased intracellular concentration of borate activates borate transporters, but also leads to growth inhibition and apoptosis. The effects of SBEs on normal cells are less dramatic because SBEs are naturally-occurring biochemicals, common and abundant in some fruits and vegetables, and also because borate dissociated from SBEs in natural diet doses is easily exported from normal cells. Cancer cell lines that over-express sugar transporters or under-express borate export are potential targets for SBE-based therapy. With regard to efficiency against cancer cells and drug preparation requirements, trigonal cis-diol boric monoesters will be one of the most effective class of SBEs. Because negative correlation exists between borate intake and the incidence of prostate cancer, and because most cancer cells overexpress sugar transporters, SBEs are proposed as a potential chemopreventive avenue in the fight against primary and recurrent prostate cancer.

  9. Chemoprevention of Lung Cancer: Prospects and Disappointments in Human Clinical Trials

    Directory of Open Access Journals (Sweden)

    William N. Rom

    2013-01-01

    Full Text Available Decreasing the risk of lung cancer, or preventing its development in high-risk individuals, would have a huge impact on public health. The most effective means to decrease lung cancer incidence is to eliminate exposure to carcinogens. However, with recent advances in the understanding of pulmonary carcinogenesis and the identification of intermediate biomarkers, the prospects for the field of chemoprevention research have improved dramatically. Here we review the most recent research in lung cancer chemoprevention—focusing on those agents that have been investigated in human clinical trials. These agents fall into three major categories. First, oxidative stress plays an important role in pulmonary carcinogenesis; and therefore, antioxidants (including vitamins, selenium, green tea extracts, and isothiocyanates may be particularly effective in preventing the development of lung cancer. Second, inflammation is increasingly accepted as a crucial factor in carcinogenesis, and many investigators have focused on anti-inflammatory agents, such as glucocorticoids, NSAIDs, statins, and PPARγ agonists. Finally, the PI3K/AKT/mTOR pathway is recognized to play a central role in tobacco-induced carcinogenesis, and inhibitors of this pathway, including myoinositol and metformin, are promising agents for lung cancer prevention. Successful chemoprevention will likely require targeting of multiple pathways to carcinogenesis—both to minimize toxicity and maximize efficacy.

  10. Regulatory approval of cancer risk-reducing (chemopreventive) drugs: moving what we have learned into the clinic.

    Science.gov (United States)

    Meyskens, Frank L; Curt, Gregory A; Brenner, Dean E; Gordon, Gary; Herberman, Ronald B; Finn, Olivera; Kelloff, Gary J; Khleif, Samir N; Sigman, Caroline C; Szabo, Eva

    2011-03-01

    This article endeavors to clarify the current requirements and status of regulatory approval for chemoprevention (risk reduction) drugs and discusses possible improvements to the regulatory pathway for chemoprevention. Covering a wide range of topics in as much depth as space allows, this report is written in a style to facilitate the understanding of nonscientists and to serve as a framework for informing the directions of experts engaged more deeply with this issue. Key topics we cover here are as follows: a history of definitive cancer chemoprevention trials and their influence on the evolution of regulatory assessments; a brief review of the long-standing success of pharmacologic risk reduction of cardiovascular diseases and its relevance to approval for cancer risk reduction drugs; the use and limitations of biomarkers for developing and the approval of cancer risk reduction drugs; the identification of individuals at a high(er) risk for cancer and who are appropriate candidates for risk reduction drugs; business models that should incentivize pharmaceutical industry investment in cancer risk reduction; a summary of scientific and institutional barriers to development of cancer risk reduction drugs; and a summary of major recommendations that should help facilitate the pathway to regulatory approval for pharmacologic cancer risk reduction drugs.

  11. Evidence supporting the conceptual framework of cancer chemoprevention in canines.

    Science.gov (United States)

    Kondratyuk, Tamara P; Adrian, Julie Ann Luiz; Wright, Brian; Park, Eun-Jung; van Breemen, Richard B; Morris, Kenneth R; Pezzuto, John M

    2016-05-24

    As with human beings, dogs suffer from the consequences of cancer. We investigated the potential of a formulation comprised of resveratrol, ellagic acid, genistein, curcumin and quercetin to modulate biomarkers indicative of disease prevention. Dog biscuits were evaluated for palatability and ability to deliver the chemopreventive agents. The extent of endogenous DNA damage in peripheral blood lymphocytes from dogs given the dietary supplement or placebo showed no change. However, H2O2-inducible DNA damage was significantly decreased after consumption of the supplement. The expression of 11 of 84 genes related to oxidative stress was altered. Hematological parameters remained in the reference range. The concept of chemoprevention for the explicit benefit of the canine is compelling since dogs are an important part of our culture. Our results establish a proof-of-principle and provide a framework for improving the health and well-being of "man's best friend".

  12. Cutting edge: chemoprevention of colorectal neoplasia in inflammatory bowel disease.

    Science.gov (United States)

    Actis, Giovanni C; Tarallo, Sonia; Rosina, Floriano

    2013-02-01

    Colitis-associated cancer represents a long-standing problem, with two new factors adding to its importance: the diffusion of inflammatory bowel disease in developing countries, and the increased availability of effective drugs that control ulcerative colitis delaying or abrogating the need for a curative colectomy. The consolidated evidence that inflammation is the unique variable that factors in colitic cancer development has conferred impetus to the search and release of anti-inflammatory/immune suppressive molecules to pursue the goal of cancer chemoprevention. Cutting-edge research has provided breakthrough insights into the mechanism of the chemopreventive actions of mesalamines, thiopurines, and probiotics, and we expand on these topics. Despite these advancements, bedside evidence is still mixed and calls for further scrutiny. Nowadays, the clinician must continue to rely on classic preventive measures such as surveillance colonoscopy, and the early and aggressive use of drugs that permit to keep the degree of mucosal inflammation to a minimum.

  13. Polyphenols: Key Issues Involved in Chemoprevention of Prostate Cancer

    Directory of Open Access Journals (Sweden)

    Sebastiano Cimino

    2012-01-01

    Full Text Available Prostate cancer is is the most common solid neoplasm and it is now recognized as one of the most important medical problems facing the male population. Due to its long latency and its identifiable preneoplastic lesions, prostate cancer is an ideal target tumor for chemoprevention. Different compounds are available and certainly polyphenols represent those with efficacy against prostate cancer. This review take a look at activity and properties of major polyphenolic substances, such as epigallocatechin-3-gallate, curcumin, resveratrol and the flavonoids quercetin and genistein. Although the current studies are limited, mechanisms of action of polyphenols added with the lack of side effects show a a start for future strategies in prostate chemoprevention.

  14. Shrimp Lipids: A Source of Cancer Chemopreventive Compounds

    Directory of Open Access Journals (Sweden)

    Armando Burgos-Hernández

    2013-10-01

    Full Text Available Shrimp is one of the most popular seafoods worldwide, and its lipids have been studied for biological activity in both, muscle and exoskeleton. Free fatty acids, triglycerides, carotenoids, and other lipids integrate this fraction, and some of these compounds have been reported with cancer chemopreventive activities. Carotenoids and polyunsaturated fatty acids have been extensively studied for chemopreventive properties, in both in vivo and in vitro studies. Their mechanisms of action depend on the lipid chemical structure and include antioxidant, anti-proliferative, anti-mutagenic, and anti-inflammatory activities, among others. The purpose of this review is to lay groundwork for future research about the properties of the lipid fraction of shrimp.

  15. Mangiferin in cancer chemoprevention and treatment: pharmacokinetics and molecular targets.

    Science.gov (United States)

    Rajendran, Peramaiyan; Rengarajan, Thamaraiselvan; Nandakumar, Natarajan; Divya, H; Nishigaki, Ikuo

    2015-02-01

    A variety of bioactive food components have been shown to modulate inflammatory responses and to attenuate carcinogenesis. Polyphenols isolated several years ago from various medicinal plants now seem to have a prominent role in the prevention and therapy of a variety of ailments. Mangiferin, a unique, important, and highly investigated polyphenol, has attracted much attention of late for its potential as a chemopreventive and chemotherapeutic agent against various types of cancer. Mangiferin has been shown to target multiple proinflammatory transcription factors, cell- cycle proteins, growth factors, kinases, cytokines, chemokines, adhesion molecules, and inflammatory enzymes. These targets can potentially mediate the chemopreventive and therapeutic effects of mangiferin by inhibiting the initiation, promotion, and metastasis of cancer. This review not only summarizes the diverse molecular targets of mangiferin, but also gives the results of various preclinical studies that have been performed in the last decade with this promising polyphenol.

  16. Chemoprevention of cancer: current evidence and future prospects [version 1; referees: 3 approved

    Directory of Open Access Journals (Sweden)

    Vassiliki Benetou

    2015-09-01

    Full Text Available Cancer chemoprevention refers to the use of agents for the inhibition, delay, or reversal of carcinogenesis before invasion. In the present review, agents examined in the context of cancer chemoprevention are classified in four major categories—hormonal, medications, diet-related agents, and vaccines—and the main representatives of each category are presented. Although there are serious constraints in the documentation of effectiveness of chemopreventive agents, mainly stemming from the long latency of the condition they are addressing and the frequent lack of intermediate biomarkers, there is little disagreement about the role of aspirin, whereas a diet rich in vegetables and fruits appears to convey more protection than individual micronutrients. Among categories of cancer chemopreventive agents, hormonal ones and vaccines might hold more promise for the future. Also, the identification of individuals who would benefit most from chemopreventive interventions on the basis of their genetic profiles could open new prospects for cancer chemoprevention.

  17. Discovery and development of sulforaphane as a cancer chemopreventive phytochemical

    Institute of Scientific and Technical Information of China (English)

    Yuesheng ZHANG; Li TANG

    2007-01-01

    Sulforaphane (SF) is a phytochemical that displays both anticarcinogenic and anticancer activity. SF modulates many cancer-related events, including suscep-tibility to carcinogens, cell death, cell cycle, angiogenesis, invasion and metastasis.We review its discovery and development as a cancer chemopreventive agent with the intention of encouraging further research on this important compound and facilitating the identification and development of new phytochemicals for cancer prevention.

  18. Phytochemicals as Anticancer and Chemopreventive Topoisomerase II Poisons

    OpenAIRE

    2013-01-01

    Phytochemicals are a rich source of anticancer drugs and chemopreventive agents. Several of these chemicals appear to exert at least some of their effects through interactions with topoisomerase II, an essential enzyme that regulates DNA supercoiling and removes knots and tangles from the genome. Topoisomerase II-active phytochemicals function by stabilizing covalent protein-cleaved DNA complexes that are intermediates in the catalytic cycle of the enzyme. As a result, these compounds convert...

  19. Evidence supporting the conceptual framework of cancer chemoprevention in canines

    OpenAIRE

    Kondratyuk, Tamara P.; Julie Ann Luiz Adrian; Brian Wright; Eun-Jung Park; van Breemen, Richard B.; Morris, Kenneth R.; Pezzuto, John M.

    2016-01-01

    As with human beings, dogs suffer from the consequences of cancer. We investigated the potential of a formulation comprised of resveratrol, ellagic acid, genistein, curcumin and quercetin to modulate biomarkers indicative of disease prevention. Dog biscuits were evaluated for palatability and ability to deliver the chemopreventive agents. The extent of endogenous DNA damage in peripheral blood lymphocytes from dogs given the dietary supplement or placebo showed no change. However, H2O2-induci...

  20. Aspirin Metabolomics in Colorectal Cancer Chemoprevention | Division of Cancer Prevention

    Science.gov (United States)

    DESCRIPTION (provided by applicant): Substantial evidence supports the effectiveness of aspirin for cancer chemoprevention in addition to its well-established role in cardiovascular protection. In recent meta-analyses of randomized controlled trials in humans, daily aspirin use reduced incidence, metastasis and mortality from several common types of cancer, especially colorectal cancer. The mechanism(s) by which aspirin exerts an anticancer benefit is uncertain;numerous effects have been described involving both cyclooxygenase-dependent and -independent pathways. |

  1. Anticarcinogenic Effects of Dietary Phytoestrogens and Their Chemopreventive Mechanisms.

    Science.gov (United States)

    Hwang, Kyung-A; Choi, Kyung-Chul

    2015-01-01

    Phytoestrogens are phenolic compounds derived from plants and exert an estrogenic as well as an antiestrogenic effect and also various biological efficacies. Chemopreventive properties of phytoestrogens has emerged from epidemiological observations indicating that the incidence of some cancers including breast and prostate cancers is much lower in Asian people, who consume significantly higher amounts of phytoestrogens than Western people. There are 4 main classes of phytoestrogens: isoflavones, stilbenes, coumestans, and lignans. Currently, resveratrol is recognized as another major phytoestrogen present in grape and red wine and has been studied in many biological studies. Phytoestrogens have biologically diverse profitabilities and advantages such as low cytotoxicity to patients, lack of side effects in clinical trials, and pronounced benefits in a combined therapy. In this review, we highlighted the effects of genistein, daidzein, and resveratrol in relation with their anticarcinogenic activity. A lot of in vitro and in vivo results on their chemopreventive properties were presented along with the underlying mechanisms. Besides well-known mechanisms such as antioxidant property and apoptosis, newly elucidated anticarcinogenic modes of action including epigenetic modifications and topoisomerase inhibition have been provided to examine the possibility of phytoestrogens as promising reagents for cancer chemoprevention and/or treatment and to suggest the importance of plant-based diet of phytoestrogens.

  2. Sulforaphane (SFN: An Isothiocyanate in a Cancer Chemoprevention Paradigm

    Directory of Open Access Journals (Sweden)

    Mohammad Fahad Ullah

    2015-07-01

    Full Text Available The International Agency for Research on Cancer (IARC in its latest World Cancer Report (2014 has projected the increase in the global cancer burden from 14 million (2012 to 22 million incidence annually within the next two decades. Such statistics warrant a collaborative engagement of conventional and complementary and alternative therapies to contain and manage cancer. In recent years, there has been a shift in the cancer chemoprevention paradigm with a significant focus turning towards bioactive components of human diets for their anticancer properties. Since diet is an integral part of lifestyle and given that an estimated one third of human cancers are believed to be preventable though appropriate lifestyle modification including dietary habits, the current shift in the conventional paradigm assumes significance. Several epidemiological studies have indicated that consumption of broccoli is associated with a lower risk of cancer incidence including breast, prostate, lung, stomach and colon cancer. The edible plant belonging to the family of cruciferae such as broccoli is a rich source of glucoraphanin, a precursor of isothiocyanate sulforaphane which is considered to be a potent anti-cancer agent. Plant-based dietary agents such as sulforaphane mimic chemotherapeutic drugs such as vorinostat, possessing histone deacetylase inhibition activity. Evidence from epidemiological and experimental studies have emerged, enhancing the clinical plausibility and translational value of sulforaphane in cancer chemoprevention. The present review provides the current understanding of the cancer chemopreventive pharmacology of sulforaphane towards its potential as an anticancer agent.

  3. [Chemoprevention of tobacco-related lung cancer by cruciferous vegetable].

    Science.gov (United States)

    Balcerek, Maciej

    2007-01-01

    Lung cancer is the most common malignant disease in the world and the major cause of death from cancers. Around 80-90% of all human lung cancers are related to cigarette smoke. Tobacco smoke contains at least 60 carcinogens capable of causing tumors, 4-(N-methyl-N-nitrosamino)-1-(3-pyridyl)-1-butanone (NNK) and polycyclic aromatic hydrocarbons (PAH) are among the most prominent pulmonary carcinogens. Prevention is the most effective way to reduce lung cancer mortality. Chemoprevention is a cancer preventive strategy to inhibit, delay or reverse carcinogenesis using naturally occurring or synthetic chemical agents. A number of epidemiological studies have shown an inverse relationship between cruciferous vegetable consumption and cancer, especially those of lung and stomach. Crucifers, such as broccoli, cauliflower, brussel sprouts and cabbage, contain a family of secondary plant metabolites known as glucosinolates, which are unique to these vegetables. Upon hydrolysis, glucosinolates yield a number of breakdown products, mostly isothiocyanates, with supposed chemopreventive properties, as shown in animal experiments. It appears that significant portion of the chemopreventive effects of isothiocyanates may be associated with the inhibition of the metabolic activation of carcinogens by cytochrome P450s (Phase I), coupled with strong induction of phase II of detoxifying enzymes.

  4. Australian clinicians and chemoprevention for women at high familial risk for breast cancer

    Directory of Open Access Journals (Sweden)

    Keogh Louise A

    2009-05-01

    Full Text Available Abstract Objectives Effective chemoprevention strategies exist for women at high risk for breast cancer, yet uptake is low. Physician recommendation is an important determinant of uptake, but little is known about clinicians' attitudes to chemoprevention. Methods Focus groups were conducted with clinicians at five Family Cancer Centers in three Australian states. Discussions were recorded, transcribed and analyzed thematically. Results Twenty three clinicians, including genetic counselors, clinical geneticists, medical oncologists, breast surgeons and gynaecologic oncologists, participated in six focus groups in 2007. The identified barriers to the discussion of the use of tamoxifen and raloxifene for chemoprevention pertained to issues of evidence (evidence for efficacy not strong enough, side-effects outweigh benefits, oophorectomy superior for mutation carriers, practice (drugs not approved for chemoprevention by regulatory authorities and not government subsidized, chemoprevention not endorsed in national guidelines and not many women ask about it, and perception (clinicians not knowledgeable about chemoprevention and women thought to be opposed to hormonal treatments. Conclusion The study demonstrated limited enthusiasm for discussing breast cancer chemoprevention as a management option for women at high familial risk. Several options for increasing the likelihood of clinicians discussing chemoprevention were identified; maintaining up to date national guidelines on management of these women and education of clinicians about the drugs themselves, the legality of "off-label" prescribing, and the actual costs of chemopreventive medications.

  5. The importance of carcinogen dose in chemoprevention studies: quantitative interrelationships between, dibenzo[a,l]pyrene dose, chlorophyllin dose, target organ DNA adduct biomarkers and final tumor outcome.

    Science.gov (United States)

    Pratt, M Margaret; Reddy, Ashok P; Hendricks, Jerry D; Pereira, Cliff; Kensler, Thomas W; Bailey, George S

    2007-03-01

    Chlorophyllin (CHL) is a potent antimutagen in vitro, an effective anti-carcinogen in several animal models, and significantly reduced urinary biomarkers of aflatoxin B(1) (AFB(1)) exposure in a human population. Here we report an expanded analysis of CHL chemoprevention using the potent environmental hydrocarbon dibenzo[a,l]pyrene (DBP). A dose-dose matrix design employed over 12 000 rainbow trout to evaluate the interrelationships among dietary carcinogen dose, anti-carcinogen dose, carcinogen-DNA adduct levels at exposure and eventual tumor outcome in two target organs. Included was an evaluation of the pharmaceutical CHL preparation (Derifil), used previously in a study of individuals chronically exposed to AFB(1). CHL was pre-, co- and post-fed at doses of 0-6000 p.p.m. and co-fed with DBP at doses of 0-371.5 p.p.m. for 4 weeks. This protocol generated a total of 21 dose-dose treatment groups, each evaluated with three or more replicates of 100 animals. The DBP-only treatment produced dose-responsive increases in liver and stomach DBP-DNA adducts, whereas increasing CHL co-treatment doses produced successive inhibition in liver (49-83%) and stomach (47-75%) adduct levels at each DBP dose examined. The remaining 8711 trout were necropsied, 10 months later. DBP treatment alone produced a logit incidence versus log [DBP] dose-response curve in stomach that was linear; CHL co-treatment provided dose-dependent tumor inhibition which ranged from 30 to 68% and was predictable from the adduct response. The Derifil CHL preparation was also found to effectively reduce DNA adduction and final tumor incidence in stomach (as well as liver), with a potency compatible with its total chlorin content. Liver tumor incidence in the DBP-only groups appeared to plateau near 60%. At DBP doses of

  6. Implications for chemoprevention of prostate cancer with intake of cruciferous vegetables

    Institute of Scientific and Technical Information of China (English)

    Jeanny B Aragon-Ching

    2011-01-01

    @@ Efforts on chemoprevention have been an attractive target of investigation for prostate cancer.Since prostate cancer is the most common non-cutaneous malignancy among American men, efforts for chemopreventative strategies make sense.However, such undertaking has been wrought with problems and wide-scale efforts to launch drug chemoprevention have been dampened by mixed results.

  7. Chemoprevention with Acetylsalicylic Acid, Vitamin D and Calcium Reduces Risk of Carcinogen-induced Lung Tumors

    DEFF Research Database (Denmark)

    Pommergaard, Hans-Christian; Burcharth, Jakob; Rosenberg, J

    2013-01-01

    Background/Aim: Research has shown that chemoprevention may be effective against the development of lung cancer. The purpose of the present study was to evaluate the effect of oral chemoprevention in a mouse model of tobacco carcinogen-induced lung tumor....

  8. ATM and Internet protocol

    CERN Document Server

    Bentall, M; Turton, B

    1998-01-01

    Asynchronous Transfer Mode (ATM) is a protocol that allows data, sound and video being transferred between independent networks via ISDN links to be supplied to, and interpreted by, the various system protocols.ATM and Internet Protocol explains the working of the ATM and B-ISDN network for readers with a basic understanding of telecommunications. It provides a handy reference to everyone working with ATM who may not require the full standards in detail, but need a comprehensive guide to ATM. A substantial section is devoted to the problems of running IP over ATM and there is some discussion o

  9. Targeting multiple signal pathways by chemopreventive agents for cancer prevention and therapy

    Institute of Scientific and Technical Information of China (English)

    Fazlul H SARKAR; Yi-wei LI

    2007-01-01

    In recent years, growing interest has been focused on the field of cancer prevention.Cancer prevention by chemopreventive agents offers significant promise for re-ducing the incidence and mortality of cancer. Chemopreventive agents may exert their effects either by blocking or metabolizing carcinogens or by inhibiting tumor cell growth. Another important benefit of chemopreventive agents is their non-toxic nature. Therefore, chemopreventive agents have recently been used for cancer treatment in combination with chemotherapeutics or radiotherapy, uncov-ering a novel strategy for cancer therapy. This strategy opens a new avenue fromcancer prevention to cancer treatment. In vitro and in vivo studies have demon-strated that chemopreventive agents could enhance the antitumor activity of chemotherapeutics, improving the treatment outcome. Growing evidence has shown that chemopreventive agents potentiate the efficacy of chemotherapy and radiotherapy through the regulation of multiple signaling pathways, including Akt, NF-κB, c-Myc, cyclooxygenase-2, apoptosis, and others, suggesting a multitargeted nature of chemopreventive agents. However, further in-depth mecha-nistic studies, in vivo animal experiments, and clinical trials are needed to investi-gate the effects of chemopreventive agents in combination treatment of cancer with conventional cancer therapies. More potent natural and synthetic chemo-preventive agents are also needed to improve the efficacy of mechanism-based and targeted therapeutic strategies against cancer, which are likely to make a significant impact on saving lives. Here, we have briefly reviewed the role of chemopreventive agents in cancer prevention, but most importantly, we have reviewed how they could be useful for cancer therapy in combination with con-ventional therapies.

  10. Plant phytochemicals as epigenetic modulators: role in cancer chemoprevention.

    Science.gov (United States)

    Thakur, Vijay S; Deb, Gauri; Babcook, Melissa A; Gupta, Sanjay

    2014-01-01

    In recent years, "nutri-epigenetics," which focuses on the influence of dietary agents on epigenetic mechanism(s), has emerged as an exciting novel area in epigenetics research. Targeting of aberrant epigenetic modifications has gained considerable attention in cancer chemoprevention research because, unlike genetic changes, epigenetic alterations are reversible and occur during early carcinogenesis. Aberrant epigenetic mechanisms, such as promoter DNA methylation, histone modifications, and miRNA-mediated post-transcriptional alterations, can silence critical tumor suppressor genes, such as transcription factors, cell cycle regulators, nuclear receptors, signal transducers, and apoptosis-inducing and DNA repair gene products, and ultimately contribute to carcinogenesis. In an effort to identify and develop anticancer agents which cause minimal harm to normal cells while effectively killing cancer cells, a number of naturally occurring phytochemicals in food and medicinal plants have been investigated. This review highlights the potential role of plant-derived phytochemicals in targeting epigenetic alterations that occur during carcinogenesis, by modulating the activity or expression of DNA methyltransferases, histone modifying enzymes, and miRNAs. We present in detail the epigenetic mode of action of various phytochemicals and discuss their potential as safe and clinically useful chemopreventive strategies.

  11. Tea beverage in chemoprevention and chemotherapy of prostate cancer

    Institute of Scientific and Technical Information of China (English)

    Imtiaz A SIDDIQUI; Mohammad SALEEM; Vaqar M ADHAMI; Mohammad ASIM; Hasan MUKHTAR

    2007-01-01

    Prostate cancer (Pca) is the most frequently diagnosed malignancy and the sec-ond leading cause of cancer-related deaths in American males with similar trends in many western countries. The existing treatment approaches and surgical inter-vention have not been able to effectively cope with this dreaded disease. For these reasons, it is necessary to intensify our efforts for a better understanding of the disease process and for the development of novel approaches for its preven-tion and treatment. Based on considerable evidence from in vivo and in vitro data and epidemiological studies, in recent years the beverage tea has gained consid-erable attention for reducing the risk of several cancers. Much of the cancerpreventive effects of tea, especially green tea appear to be mediated by the polyphe-nols present therein. Geographical evidence suggests that the incidence and occurrence of Pca is lower in populations that consume tea regularly. This evi-dence suggests that tea polyphenols could be extrapolated to optimize their chemopreventive properties against Pca. Pca represents an excellent candidate disease for chemoprevention because it is typically diagnosed in men over 50 years of age and therefore, even a modest delay in neoplastic development achieved through pharmacological or nutritional intervention could result in a substantial reduction in the incidence of clinically detectable disease. In this review we address the issue of possible use of tea, especially green tea, for the prevention aswell as treatment of Pca.

  12. Ginseng Metabolites on Cancer Chemoprevention: An Angiogenesis Link?

    Directory of Open Access Journals (Sweden)

    Chong-Zhi Wang

    2015-09-01

    Full Text Available Cancer is a leading cause of death in the United States. Angiogenesis inhibitors have been introduced for the treatment of cancer. Based on the fact that many anticancer agents have been developed from botanical sources, there is a significant untapped resource to be found in natural products. American ginseng is a commonly used herbal medicine in the U.S., which possesses antioxidant properties. After oral ingestion, natural ginseng saponins are biotransformed to their metabolites by the enteric microbiome before being absorbed. The major metabolites, ginsenoside Rg3 and compound K, showed significant potent anticancer activity compared to that of their parent ginsenosides Rb1, Rc, and Rd. In this review, the molecular mechanisms of ginseng metabolites on cancer chemoprevention, especially apoptosis and angiogenic inhibition, are discussed. Ginseng gut microbiome metabolites showed significant anti-angiogenic effects on pulmonary, gastric and ovarian cancers. This review suggests that in addition to the chemopreventive effects of ginseng compounds, as angiogenic inhibitors, ginsenoside metabolites could be used in combination with other cancer chemotherapeutic agents in cancer management.

  13. Resveratrol and aspirin eliminate tetraploid cells for anticancer chemoprevention.

    Science.gov (United States)

    Lissa, Delphine; Senovilla, Laura; Rello-Varona, Santiago; Vitale, Ilio; Michaud, Mickaël; Pietrocola, Federico; Boilève, Alice; Obrist, Florine; Bordenave, Chloé; Garcia, Pauline; Michels, Judith; Jemaà, Mohamed; Kepp, Oliver; Castedo, Maria; Kroemer, Guido

    2014-02-25

    Tetraploidy constitutes a genomically metastable state that can lead to aneuploidy and genomic instability. Tetraploid cells are frequently found in preneoplastic lesions, including intestinal cancers arising due to the inactivation of the tumor suppressor adenomatous polyposis coli (APC). Using a phenotypic screen, we identified resveratrol as an agent that selectively reduces the fitness of tetraploid cells by slowing down their cell cycle progression and by stimulating the intrinsic pathway of apoptosis. Selective killing of tetraploid cells was observed for a series of additional agents that indirectly or directly stimulate AMP-activated protein kinase (AMPK) including salicylate, whose chemopreventive action has been established by epidemiological studies and clinical trials. Both resveratrol and salicylate reduced the formation of tetraploid or higher-order polyploid cells resulting from the culture of human colon carcinoma cell lines or primary mouse epithelial cells lacking tumor protein p53 (TP53, best known as p53) in the presence of antimitotic agents, as determined by cytofluorometric and videomicroscopic assays. Moreover, oral treatment with either resveratrol or aspirin, the prodrug of salicylate, repressed the accumulation of tetraploid intestinal epithelial cells in the Apc(Min/+) mouse model of colon cancer. Collectively, our results suggest that the chemopreventive action of resveratrol and aspirin involves the elimination of tetraploid cancer cell precursors.

  14. The role of aspirin in colorectal cancer chemoprevention.

    Science.gov (United States)

    Singh Ranger, Gurpreet

    2016-08-01

    Considerable interest has emerged over the last decade regarding the role of aspirin in prevention of colorectal cancer. This disease is one of the commonest cancers in the Western World, therefore, the existence of a simple "everyday" agent, which could have the ability to prevent the disease, represents an invaluable opportunity clinicians may be able to exploit. Evidence from case-control and cohort studies, and recent updates of randomised controlled trials have been very encouraging-indicating benefit from long term use of aspirin at low dose. Possible mechanisms of chemoprevention include inhibition of the cyclooxygenase (COX) pathway, or COX-independent mechanisms, for example, the PIK3CA pathway, or therapy-induced senescence of cancer cells. The most serious side effect of prolonged aspirin treatment is haemorrhage, especially from the GI tract. This is likely to be less of a problem with chemoprevention at lower doses. One also needs to consider the impact if aspirin resistance, an increasingly recognised clinical entity.

  15. Carnosol: A Phenolic Diterpene With Cancer Chemopreventive Potential

    Science.gov (United States)

    Chun, Kyung-Soo; Kundu, Juthika; Chae, In Gyeong; Kundu, Joydeb Kumar

    2014-01-01

    Cancer is an unbeaten health challenge for the humankind. After striving for decades to find a cancer cure, attention has now been shifted to reduce the morbidity and mortality from cancer by halting the course of tumor development. Numerous bioactive phytochemicals, especially those present in edible and non-edible plant species, have been reported to reduce the risk of many cancers. Multiple lines of evidence suggest that carnosol, a phenolic diterpene present in rosemary (Rosmarinus officinalis L.), holds the promise of preventing certain types of cancer. A remarkable progress has been made in delineating the biochemical mechanisms underlying the chemopreventive effects of carnosol. Results from in vitro cell culture studies as well as animal model experiments have revealed that carnosol inhibits experimentally induced carcinogenesis and exhibits potent anti-oxidative, anti-inflammatory, antiproliferative and apoptosis inducing properties. Moreover, carnosol enhances the sensitivity of chemoresistant cancer cells to chemotherapeutic agents. The purpose of this review is to shed light on the detailed mechanistic aspects of cancer chemoprevention with carnosol. PMID:25337578

  16. Quantum deniable authentication protocol

    Science.gov (United States)

    Shi, Wei-Min; Zhou, Yi-Hua; Yang, Yu-Guang

    2014-07-01

    The proposed quantum identity authentication schemes only involved authentication between two communicators, but communications with deniability capability are often desired in electronic applications such as online negotiation and electronic voting. In this paper, we proposed a quantum deniable authentication protocol. According to the property of unitary transformation and quantum one-way function, this protocol can provide that only the specified receiver can identify the true source of a given message and the specified receiver cannot prove the source of the message to a third party by a transcript simulation algorithm. Moreover, the quantum key distribution and quantum encryption algorithm guarantee the unconditional security of this scheme. Security analysis results show that this protocol satisfies the basic security requirements of deniable authentication protocol such as completeness and deniability and can withstand the forgery attack, impersonation attack, inter-resend attack.

  17. Evaluating the effectiveness of exercise training on elderly patients who require haemodialysis: study protocol for a systematic review and meta-analysis

    Science.gov (United States)

    Matsuzawa, Ryota; Hoshi, Keika; Yoneki, Kei; Matsunaga, Atsuhiko

    2016-01-01

    Introduction As the average age of haemodialysis patients rapidly increases around the world, the number of frail, elderly patients has increased. Frailty is well known to be an indicator of disability and a poor prognosis for haemodialysis patients. Exercise interventions have been safely and successfully implemented for middle-aged or younger patients undergoing haemodialysis. However, the benefits of exercise interventions on elderly patients undergoing haemodialysis remain controversial. The main objective of this study is to systematically review the effects of exercise training on the physical function, exercise capacity and quality of life of elderly patients undergoing haemodialysis, and to provide an update on the relevant evidence. Methods and analyses Published randomised controlled trials (RCTs) that assessed the effectiveness of exercise training on haemodialysis patients with respect to physical function, exercise tolerance and quality of life will be included. Bibliographic databases include MEDLINE, EMBASE, the Cochrane Central Register of Controlled Trials, the Cochrane Database of Systematic Reviews, CINAHL, Web of Science, PsycINFO and PEDro. The risk of bias of the included RCTs will be assessed using the Cochrane Collaboration's tool and TESTEX. The primary outcome will be physical function and exercise tolerance. This review protocol is reported according to the PRISMA-P 2015 checklist. Statistical analysis will be performed using review manager software (RevMan V.5.3, Cochrane Collaboration, Oxford, England). Ethics and dissemination Ethical approval is not required because this study does not include confidential personal data nor does it perform interventions on patients. This review is expected to inform readers on the effectiveness of exercise training in elderly patients undergoing haemodialysis. Findings will be presented at conferences and submitted to a peer-reviewed journal for publication. PROSPERO registration number CRD42015020701

  18. CT protocol review and optimization.

    Science.gov (United States)

    Kofler, James M; Cody, Dianna D; Morin, Richard L

    2014-03-01

    To reduce the radiation dose associated with CT scans, much attention is focused on CT protocol review and improvement. In fact, annual protocol reviews will soon be required for ACR CT accreditation. A major challenge in the protocol review process is determining whether a current protocol is optimal and deciding what steps to take to improve it. In this paper, the authors describe methods for pinpointing deficiencies in CT protocols and provide a systematic approach for optimizing them. Emphasis is placed on a team approach, with a team consisting of at least one radiologist, one physicist, and one technologist. This core team completes a critical review of all aspects of a CT protocol and carefully evaluates proposed improvements. Changes to protocols are implemented only with consensus of the core team, with consideration of all aspects of the CT examination, including image quality, radiation dose, patient care and safety, and workflow.

  19. Molecular mechanisms of chemopreventive phytochemicals against gastroenterological cancer development.

    Science.gov (United States)

    Chung, Min-Yu; Lim, Tae Gyu; Lee, Ki Won

    2013-02-21

    Cancer is one of the leading causes of death worldwide. Commonly used cancer treatments, including chemotherapy and radiation therapy, often have side effects and a complete cure is sometimes impossible. Therefore, prevention, suppression, and/or delaying the onset of the disease are important. The onset of gastroenterological cancers is closely associated with an individual's lifestyle. Thus, changing lifestyle, specifically the consumption of fruits and vegetables, can help to protect against the development of gastroenterological cancers. In particular, naturally occurring bioactive compounds, including curcumin, resveratrol, isothiocyanates, (-)-epigallocatechin gallate and sulforaphane, are regarded as promising chemopreventive agents. Hence, regular consumption of these natural bioactive compounds found in foods can contribute to prevention, suppression, and/or delay of gastroenterological cancer development. In this review, we will summarize natural phytochemicals possessing potential antioxidant and/or anti-inflammatory and anti-carcinogenic activities, which are exerted by regulating or targeting specific molecules against gastroenterological cancers, including esophageal, gastric and colon cancers.

  20. Review paper: Cancer chemopreventive compounds and canine cancer.

    Science.gov (United States)

    Baek, S J; McEntee, M F; Legendre, A M

    2009-07-01

    Canine cancer has become more prevalent in recent years because of increased life expectancy and greater attention to the health of pets. The range of cancers seen in dogs is as diverse as that in human patients, and despite more intensive therapeutic interventions, fatality rates remain unacceptably high in both species. Chemoprevention is therefore an important means of confronting this disease. Because domestic pets share our environment, greater cross-application and study of the protumorigenic and antitumorigenic factors in our shared environment will benefit all species, leading to the development of new families of less toxic antitumorigenic compounds based on novel and established molecular targets. Currently, the most interesting cancer preventive agents are nonsteroidal anti-inflammatory drugs, peroxisome proliferator-activated receptor-gamma ligands, and dietary compounds. This article provides an overview of what is known about how these agents affect molecular signaling in neoplastic disease, with reference to reported application and/or study in dogs where available.

  1. Aspirin as a chemoprevention agent for colorectal cancer.

    LENUS (Irish Health Repository)

    Lee, Chun Seng

    2012-11-01

    Colorectal cancer (CRC) is one of the leading causes of mortality in the western world. It is widely accepted that neoplasms such as colonic polyps are precursors to CRC formation; with the polyp-adenoma-carcinoma sequences well described in medical literature [1, 2]. It has been shown that Aspirin and other non-steroid anti-inflammatory drugs (NSAID) have a negative effect on polyp and cancer formation. This review aims to describe some of the mechanism behind the chemoprotective properties of aspirin; COX 2 inhibition, regulation of proliferation and apoptosis and effects on the immune system and also the current evidence that supports its use as a chemoprevention agent against CRC. We will also aim to explore the side effects with the use of aspirin and the pitfalls of using aspirin routinely for primary prophylaxis against CRC.

  2. Oral Carcinogenesis and Oral Cancer Chemoprevention: A Review

    Directory of Open Access Journals (Sweden)

    Takuji Tanaka

    2011-01-01

    Full Text Available Oral cancer is one of the major global threats to public health. The development of oral cancer is a tobacco-related multistep and multifocal process involving field cancerization and carcinogenesis. The rationale for molecular-targeted prevention of oral cancer is promising. Biomarkers of genomic instability, including aneuploidy and allelic imbalance, are possible to measure the cancer risk of oral premalignancies. Understanding of the biology of oral carcinogenesis will yield important advances for detecting high-risk patients, monitoring preventive interventions, and assessing cancer risk and pharmacogenomics. In addition, novel chemopreventive agents based on molecular mechanisms and targets against oral cancers will be derived from studies using appropriate animal carcinogenesis models. New approaches, such as molecular-targeted agents and agent combinations in high-risk oral individuals, are undoubtedly needed to reduce the devastating worldwide consequences of oral malignancy.

  3. Survey protocol for invasive species

    OpenAIRE

    Menza, Charles

    2009-01-01

    This protocol was developed by the Biogeography Branch of NOAA’s Center for Coastal Monitoring and Assessment to support invasive species research by the Papahānaumokuākea Marine National Monument. The protocol’s objective is to detect Carijoa riisei and Hypnea musciformis in deepwater habitats using visual surveys by technical divers. Note: This protocol is designed to detect the presence or absence of invasive species. A distinct protocol is required to collect information on abundance ...

  4. Nanoencapsulation of pomegranate bioactive compounds for breast cancer chemoprevention.

    Science.gov (United States)

    Shirode, Amit B; Bharali, Dhruba J; Nallanthighal, Sameera; Coon, Justin K; Mousa, Shaker A; Reliene, Ramune

    2015-01-01

    Pomegranate polyphenols are potent antioxidants and chemopreventive agents but have low bioavailability and a short half-life. For example, punicalagin (PU), the major polyphenol in pomegranates, is not absorbed in its intact form but is hydrolyzed to ellagic acid (EA) moieties and rapidly metabolized into short-lived metabolites of EA. We hypothesized that encapsulation of pomegranate polyphenols into biodegradable sustained release nanoparticles (NPs) may circumvent these limitations. We describe here the development, characterization, and bioactivity assessment of novel formulations of poly(D,L-lactic-co-glycolic acid)-poly(ethylene glycol) (PLGA-PEG) NPs loaded with pomegranate extract (PE) or individual polyphenols such as PU or EA. Monodispersed, spherical 150-200 nm average diameter NPs were prepared by the double emulsion-solvent evaporation method. Uptake of Alexa Fluor-488-labeled NPs was evaluated in MCF-7 breast cancer cells over a 24-hour time course. Confocal fluorescent microscopy revealed that PLGA-PEG NPs were efficiently taken up, and the uptake reached the maximum at 24 hours. In addition, we examined the antiproliferative effects of PE-, PU-, and/or EA-loaded NPs in MCF-7 and Hs578T breast cancer cells. We found that PE, PU, and EA nanoprototypes had a 2- to 12-fold enhanced effect on cell growth inhibition compared to their free counterparts, while void NPs did not affect cell growth. PU-NPs were the most potent nanoprototype of pomegranates. Thus, PU may be the polyphenol of choice for further chemoprevention studies with pomegranate nanoprototypes. These data demonstrate that nanotechnology-enabled delivery of pomegranate polyphenols enhances their anticancer effects in breast cancer cells. Thus, pomegranate polyphenols are promising agents for nanochemoprevention of breast cancer.

  5. The Network Protocol Analysis Technique in Snort

    Science.gov (United States)

    Wu, Qing-Xiu

    Network protocol analysis is a network sniffer to capture data for further analysis and understanding of the technical means necessary packets. Network sniffing is intercepted by packet assembly binary format of the original message content. In order to obtain the information contained. Required based on TCP / IP protocol stack protocol specification. Again to restore the data packets at protocol format and content in each protocol layer. Actual data transferred, as well as the application tier.

  6. Can transcriptomics provide insight into the underlying chemopreventive mechanisms of complex mixtures of phytochemicals in humans?

    NARCIS (Netherlands)

    Breda, van S.G.; Wilms, L.C.; Gaj, S.; Briedé, J.J.; Helsper, J.P.F.G.; Kleinjans, J.C.; Kok, de T.M.

    2014-01-01

    Blueberries contain relatively large amounts of different phytochemicals which are suggested to have chemopreventive properties, but little information is available on the underlying molecular modes of action. This study investigates whole genome gene expression changes in lymphocytes of 143 humans

  7. About the Chemopreventive Agent Development Research Group | Division of Cancer Prevention

    Science.gov (United States)

    The Chemopreventive Agent Development Research Group promotes and supports research on early chemopreventive agent development, from preclinical studies to phase I clinical trials. The group’s projects aim to identify and develop prevention agents with the potential to block, reverse, or delay the early stages of cancer. The overarching goal is to determine positive and negative predictive values of preclinical models for clinical development. |

  8. IP Routing Protocols

    Science.gov (United States)

    Nolasco Pinto, Armando

    2002-03-01

    Uyless Black is a widely known expert in computer networks and data communications. He is author of more than ten books in the communication technologies field, which puts him in a good position to address this topic. In IP Routing Protocols he starts by providing the background and concepts required for understanding TCP/IP technology. This is done clearly and assumes little prior knowledge of the area. As might be expected, he emphasizes the IP route discovery problem. Later he details several routing protocols.

  9. Biomarker and animal models for assessment of retinoid efficacy in cancer chemoprevention

    Institute of Scientific and Technical Information of China (English)

    Richard M NILES

    2007-01-01

    Vitamin A is essential for normal growth and development. Epidemiology and laboratory studies suggest that decreased vitamin A levels and defective metabo-lisrn/action may contribute to the genesis of certain cancers. Based on this information, natural and synthetic derivatives of vitamin A (retinoids) have been used for chemoprevention of cancer. Retinoids have had some success in the chemoprevention of leukoplakia and in the decreased incidence of second prima-ties in head and neck cancer. There is little information on biomarkers that can be used to assess the efficacy of the chemopreventive activity of retinoids. The ability of retinoids to induce RARb has been consistently shown to correlate with the response of cells and tissues to retinoic acid, but few other biomarkers have been certified as indicators of retinoid activity. In light of the failure of the ATBC and CARET clinical intervention trials for chemoprevention of lung cancer, greater use of animal models for chemoprevention studies is necessary. The potential combination of phytochemicals that inhibit DNA methyltransferase activity with retinoids holds promise for more effective chemoprevention of retinoid-unrespon-sive premalignant lesions.

  10. Piroxicam and other cyclooxygenase inhibitors: potential for cancer chemoprevention.

    Science.gov (United States)

    Earnest, D L; Hixson, L J; Alberts, D S

    1992-01-01

    Piroxicam is a nonsteroidal anti-inflammatory drug (NSAID) widely used for treatment of inflammatory arthritis. Recent experimental and clinical studies suggest that piroxicam, as well as other NSAIDs, may be useful for chemoprevention of colon cancer. While there is less information regarding NSAIDs for chemoprevention of urinary bladder malignancy, there are compelling data which suggest that this should be evaluated. A major effect of NSAIDs is inhibition of cyclooxygenase, the rate-limiting enzyme for conversion of arachidonic acid to important signal molecules, including prostaglandins, which profoundly affect cellular functions in many tissues. The initial enzyme reaction leading to formation of prostaglandin H can be accompanied by cooxidation of xenobiotics resulting in extrahepatic and local tissue production of reactive products which are carcinogenic. The end product prostaglandins, especially prostaglandin E2 (PGE2), are biological modifiers which can significantly affect cell proliferation and tumor growth. High levels of PGE2 stimulate growth of certain tumor cell lines while inhibition of prostaglandin synthesis with indomethacin or piroxicam can cause suppression. The mechanisms for this effect are unclear. Studies in cultured cells exposed to indomethacin show inhibition of G1-to-S phase progression of the cell cycle and a reduction in overall DNA synthesis. It is unclear whether this effect on cell growth results from some direct action of the NSAID or a reduction in prostaglandins or indirectly from modulation of important control signals, such as calcium flux. In addition to cyclooxygenase, NSAIDs can inhibit activity of other enzymes, including phosphodiesterases and cyclic GMP-AMP protein kinases, which may be central to cancer initiation and promotion. NSAIDs can also interfere with transmembrane ion fluxes and with cell-to-cell binding. Prostaglandins can modulate a variety of immunological responses and thereby play an important role in

  11. Histology protocols

    Directory of Open Access Journals (Sweden)

    CarloAlberto Redi

    2010-06-01

    Full Text Available Tim D. Hewitson & Ian A. Darby (Eds Humana press, Totowa, New Jersey (USA Series: Springer Protocols Methods in Molecular Biology, Volume 611, 2010 Pages: 230; € 83.15 ISBN: 978-1-60327-344-2 Impressive as it can sounds in the era that Biology see a clear dominance of reductionism with the idea that complexity can be disentagled more and more thanks to the use of molecular tools, the reader will remain fascinated by this slim and agile volume devoted to bring together what apparently are two separeted words: molecular biology and histology. Simply remembering to the youngest scientists.....

  12. Cancer chemoprevention with green tea catechins: from bench to bed.

    Science.gov (United States)

    Shirakami, Yohei; Shimizu, Masahito; Moriwaki, Hisataka

    2012-12-01

    Many epidemiological studies and a large number of experimental studies using a variety of animal models have observed that consumption or administration of green tea appears to exert cancer chemopreventive activity. Based on the results of numerous laboratory cell culture investigations, several mechanisms have been hypothesized to underlie the anti-cancer activity of green tea catechins, especially that of (-)-epigallocatechin-3-gallate (EGCG), the most abundant and active constituent in green tea. These mechanisms include promotion of anti-oxidant activity, inhibition of NF-κB and AP-1, regulation of the cell cycle, inhibition of receptor tyrosine kinase pathways, control of epigenetic modifications, and modulation of the immune system. Several recent interventional studies examining the anti-carcinogenic properties of green tea catechins in humans have yielded promising results that suggest the possibility of their application to human clinical trials. This review article analyzes the results of these studies to explicate the effects of consumption or administration of green tea and its constituents on malignancies observed to date and discuss future directions in this research field.

  13. Anti-inflammatory phytochemicals for chemoprevention of colon cancer.

    Science.gov (United States)

    Madka, Venkateshwar; Rao, Chinthalapally V

    2013-06-01

    Every year more than a million new cancer cases and 600,000 deaths are reported world-wide. Colorectal cancer is the fourth most commonly occurring and second leading cause of cancer deaths in the United States. Significant progress has been made in understanding colorectal cancer through epidemiological, laboratory and clinical studies. Development of metastatic adenocarcinomas is a multistage process occurring over several years during which multiple genetic alterations and pathophysiological changes are associated. Colorectal cancer can be prevented if the transformation of normal colonic crypt cells to malignant can be halted or reversed. Some of the key molecules that are altered significantly and play important roles in colorectal tumor progression are associated with inflammation. Since chronic inflammation is now recognized as a potential risk factor for tumor development, targeting inflammatory pathways has proven effective in preventing formation of colonic tumors and their malignant progression in both preclinical and clinical studies. Synthetic non-steroidal anti-inflammatory drugs (NSAIDS) have been identified as potential colorectal cancer chemopreventive agents; however, most of these synthetic agents are associated with unwanted and sometimes fatal side effects. There is mounting evidence in support of the efficacy of naturally-occurring phytochemicals possessing anti-inflammatory activity. In this review we discuss key inflammatory pathways associated with colorectal cancer and promising naturally-occurring phytochemicals as anti-inflammatory agents for the prevention and treatment of colorectal cancer.

  14. Molecular targets of cancer chemoprevention by garlic-derived organosulfides

    Institute of Scientific and Technical Information of China (English)

    Anna HERMAN-ANTOSIEWICZ; Anna A POWOLNY; Shivendra V SINGH

    2007-01-01

    The medicinal benefits of Allium vegetables, especially garlic, have been noted throughout recorded history. The known health benefits of Allium vegetables and their constituents include cardiovascular protective effects, stimulation of immune function, reduction of blood glucose level, radioprotection, improvement of memory loss, protection against microbial, viral and fungal infections, as well as anticancer effects. Population-based case control studies have suggested an inverse correlation between dietary intake of Allium vegetables and the risk of different types of cancers. The anticarcinogenic effect of Allium vegetables in-eluding garlic is attributed to organosulfur compounds (OSC), which are highly effective in affording protection against cancer in animal models induced by a variety of chemical carcinogens. More recent studies have shown that certain naturally occurring OSC analogues can suppress proliferation of cancer cells in culture and in vivo. The OSC-induced changes in the proliferation of cancer Cellsare frequently associated with perturbations in cell cycle progression and induc-tion of G2/M phase arrest. The OSC have also been demonstrated to induce apoptosis via the intrinsic pathway by altering the ratio of the Bc1-2 family of proteins both in cell culture and in in vivo models. Anti-angiogenic activity for garlic-derived OSC has also been documented. This article summarizes current knowledge on molecular targets of cancer chemoprevention by OSC.

  15. Plant Polyphenols as Chemopreventive Agents for Lung Cancer

    Directory of Open Access Journals (Sweden)

    Madumani Amararathna

    2016-08-01

    Full Text Available Lung cancer may be prevented by a diet rich in fruits and vegetables as they are enriched with dietary antioxidant polyphenols, such as flavonoids, proanthocyanidins, lignans, stilbenes, and phenolic acids. Dietary polyphenols exert a wide range of beneficial biological functions beyond their antioxidative properties and are involved in regulation of cell survival pathways leading to anticarcinogenic and antimutagenic functions. There are sufficient evidence from in vitro, in vivo, and epidemiological studies to suggest that the dietary intervention of polyphenols in cancer prevention, including the chemopreventive ability of dietary polyphenols, act against lung carcinogens. Cohort and epidemiological studies in selected risk populations have evaluated clinical effects of polyphenols. Polyphenols have demonstrated three major actions: antioxidative activity, regulation of phase I and II enzymes, and regulation of cell survival pathways against lung carcinogenesis. They have also shown an inverse association of lung cancer occurrences among high risk populations who consumed considerable amounts of fruits and vegetables in their daily diet. In in vitro cell culture experimental models, polyphenols bind with electrophilic metabolites from carcinogens, inactivate cellular oxygen radicals, prevent membrane lipid peroxidation and DNA oxidative damage, and adduct formation. Further, polyphenols enhance the detoxifying enzymes such as the phase II enzymes, glutathione transferases and glucuronosyl transferases.

  16. Plant Polyphenols as Chemopreventive Agents for Lung Cancer

    Science.gov (United States)

    Amararathna, Madumani; Johnston, Michael R.; Rupasinghe, H. P. Vasantha

    2016-01-01

    Lung cancer may be prevented by a diet rich in fruits and vegetables as they are enriched with dietary antioxidant polyphenols, such as flavonoids, proanthocyanidins, lignans, stilbenes, and phenolic acids. Dietary polyphenols exert a wide range of beneficial biological functions beyond their antioxidative properties and are involved in regulation of cell survival pathways leading to anticarcinogenic and antimutagenic functions. There are sufficient evidence from in vitro, in vivo, and epidemiological studies to suggest that the dietary intervention of polyphenols in cancer prevention, including the chemopreventive ability of dietary polyphenols, act against lung carcinogens. Cohort and epidemiological studies in selected risk populations have evaluated clinical effects of polyphenols. Polyphenols have demonstrated three major actions: antioxidative activity, regulation of phase I and II enzymes, and regulation of cell survival pathways against lung carcinogenesis. They have also shown an inverse association of lung cancer occurrences among high risk populations who consumed considerable amounts of fruits and vegetables in their daily diet. In in vitro cell culture experimental models, polyphenols bind with electrophilic metabolites from carcinogens, inactivate cellular oxygen radicals, prevent membrane lipid peroxidation and DNA oxidative damage, and adduct formation. Further, polyphenols enhance the detoxifying enzymes such as the phase II enzymes, glutathione transferases and glucuronosyl transferases. PMID:27548149

  17. Chemopreventive effect of apple and berry fruits against colon cancer.

    Science.gov (United States)

    Jaganathan, Saravana Kumar; Vellayappan, Muthu Vignesh; Narasimhan, Gayathri; Supriyanto, Eko; Octorina Dewi, Dyah Ekashanti; Narayanan, Aqilah Leela T; Balaji, Arunpandian; Subramanian, Aruna Priyadarshini; Yusof, Mustafa

    2014-12-07

    Colon cancer arises due to the conversion of precancerous polyps (benign) found in the inner lining of the colon. Prevention is better than cure, and this is very true with respect to colon cancer. Various epidemiologic studies have linked colorectal cancer with food intake. Apple and berry juices are widely consumed among various ethnicities because of their nutritious values. In this review article, chemopreventive effects of these fruit juices against colon cancer are discussed. Studies dealing with bioavailability, in vitro and in vivo effects of apple and berry juices are emphasized in this article. A thorough literature survey indicated that various phenolic phytochemicals present in these fruit juices have the innate potential to inhibit colon cancer cell lines. This review proposes the need for more preclinical evidence for the effects of fruit juices against different colon cancer cells, and also strives to facilitate clinical studies using these juices in humans in large trials. The conclusion of the review is that these apple and berry juices will be possible candidates in the campaign against colon cancer.

  18. Crocus sativus L. (saffron) for cancer chemoprevention: A mini review.

    Science.gov (United States)

    Bhandari, Prasan R

    2015-04-01

    Cancer is one of the most feared diseases globally and there has been a sustained rise in its incidence in both developing and developed countries. Despite the growing therapeutic options for patients with cancer, their efficacy is time-limited and non-curative. Hence to overcome these drawbacks, an incessant screening for superior and safer drugs has been ongoing for numerous decades, resulting in the detection of anti-cancer properties of several phytochemicals. Chemoprevention using readily available natural substances from vegetables, fruits, herbs and spices is one of the significantly important approaches for cancer prevention in the present era. Among the spices, Crocus sativus L. (saffron; fān hóng huā) has generated interest because pharmacological experiments have established numerous beneficial properties including radical scavenging, anti-mutagenic and immuno-modulating effects. The more powerful components of saffron are crocin, crocetin and safranal. Studies in animal models and with cultured human malignant cell lines have demonstrated antitumor and cancer preventive activities of saffron and its main ingredients. This review provides a brief insight into the anticancer properties of saffron and its components.

  19. Chemopreventive functions and molecular mechanisms of garlic organosulfur compounds.

    Science.gov (United States)

    Trio, Phoebe Zapanta; You, Sixiang; He, Xi; He, Jianhua; Sakao, Kozue; Hou, De-Xing

    2014-05-01

    Garlic (Allium sativum L.) has long been used both for culinary and medicinal purposes by many cultures. Population and preclinical investigations have suggested that dietary garlic intake has health benefits, such as lowering the risk of esophageal, stomach and prostate cancers. Extensive studies from laboratory and animal models have revealed that garlic has a wide range of biological activities, and garlic organosulfur compounds (OSCs) are responsible for the biological activities. However, the presence and potency of garlic OSCs vary with respect to the mode of garlic preparation and extraction. Cooked or processed garlic products showed different kinds of garlic OSCs, some of which are highly unstable and instantly decomposed. These facts, possibly gave paradoxical results on the garlic effects. In this review, we first summarized the biotransformation processes of garlic alliin into different garlic OSCs as well as the garlic OSCs compositions from different garlic preparations. Next, we reviewed the chemopreventive functions and molecular mechanisms focusing on the anti-inflammation, antioxidation, anti-diabetes and anticancer activity behind different garlic OSCs.

  20. Chemopreventive effect of resveratrol, sesamol, sesame oil and sunflower oil in the Epstein-Barr virus early antigen activation assay and the mouse skin two-stage carcinogenesis.

    Science.gov (United States)

    Kapadia, Govind J; Azuine, Magnus A; Tokuda, Harukuni; Takasaki, Midori; Mukainaka, Teruo; Konoshima, Takao; Nishino, Hoyoku

    2002-06-01

    Resveratrol, sesamol, sesame oil and sunflower oil are known natural dietary components with intrinsic cancer chemopreventive potentials. As a part of our study of dietary constituents as potential cancer chemopreventive agents, we have assessed the anti-cancer potentials of these products in the promotion stage of cancer development employing the in vitro Epstein-Barr virus early antigen activation assay induced by the tumor promoter 12-O-tetradecanoylphorbol 13-acetate (TPA). Further, we studied the activities of these compounds in the brine shrimp cytotoxicity assay as well as on the stable 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging bioassay with a view to comparing some of the mechanisms of their anti-cancer activity. Finally, we compared the observed chemoprotective capabilities of the four products in the in vivo 7,12 dimethylbenz(a)anthracene initiated and TPA-promoted mouse skin two-stage carcinogenesis protocols. All the products tested showed a profound inhibitory effect on the Epstein-Barr virus early antigen induction using Raji cells. Comparatively, sesame oil was the most potent followed by sesamol and then resveratrol. Only sesamol and resveratrol showed a remarkable cytotoxic activity in the brine shrimp lethality assays as well as profound free radical scavenging activity in the DPPH bioassay. In both test systems, sesamol exhibited a more remarkable activity than resveratrol while sesame oil and sunflower oil did not exhibit any appreciable activity even at the highest concentrations tested (4000 microg ml(-1) ). In our in vivo assay at a 50-fold molar ratio to TPA, sesamol offered 50% reduction in mouse skin papillomas at 20 weeks after promotion with TPA. Under an identical molar ratio to TPA, resveratrol offered a 60% reduction in the papillomas in mouse at 20 weeks. Thus sesamol seems to be an almost equally potent chemopreventive agent. Sesame oil and sunflower oil offered 20 and 40% protection, respectively, in the mouse

  1. The Role of Nutraceuticals in Chemoprevention and Chemotherapy and Their Clinical Outcomes

    Directory of Open Access Journals (Sweden)

    Sabita N. Saldanha

    2012-01-01

    Full Text Available The genesis of cancer is often a slow process and the risk of developing cancer increases with age. Altering a diet that includes consumption of beneficial phytochemicals can influence the balance and availability of dietary chemopreventive agents. In chemopreventive approaches, foods containing chemicals that have anticancer properties can be supplemented in diets to prevent precancerous lesions from occurring. This necessitates further understanding of how phytochemicals can potently maintain healthy cells. Fortunately there is a plethora of plant-based phytochemicals although few of them are well studied in terms of their application as cancer chemopreventive and therapeutic agents. In this analysis we will examine phytochemicals that have strong chemopreventive and therapeutic properties in vitro as well as the design and modification of these bioactive compounds for preclinical and clinical applications. The increasing potential of combinational approaches using more than one bioactive dietary compound in chemoprevention or cancer therapy will also be evaluated. Many novel approaches to cancer prevention are on the horizon, several of which are showing great promise in saving lives in a cost-effective manner.

  2. Using an international workshop to develop functional requirements and a Biohazard Assessment Protocol (BAP) with which to develop a preferred concept for a Mars Sample Return (MSR) Sample Receiving Facility (SRF).

    Science.gov (United States)

    Vrublevskis, John; Guest, Michael; Bennett, Allan; Walker, James; Smith, Caroline; Baker, Robert; Grant, Colin

    COSPAR Planetary Protection Policy places very stringent requirements on Sample Return missions and `breaking the chain of contact' between Earth and the celestial body from which the sample is returned. This must be continued after return to Earth and -at the same time-any contamination or damage to the sample must be avoided until such time as it can be confirmed as not presenting a biohazard and available for subsequent curation and scientific investigation. Such a facility has never before been built and an investigation has been made to determine the requirements for a Mars Sample Return (MSR) Sample Receiving Facility (SRF) from first principles based on a Biohazard Assessment Protocol (BAP) rather than the modification of an existing BSL-4 facility. This approach fully takes in to account cleanliness requirements to avoid sample contamination. This paper will present the results from the first part of an ESA funded study, which derived the top level functional requirements by reviewing published scientific literature from all expert domains i.e.; biocontainment, science curation, space technology, infrastructure and equipment. These functional requirements were then examined by invited attendees from all expert domains in a 2 day international workshop. From the results of the international workshop an existing Biohazard Assessment Protocol (BAP) was modified and a trade off was conducted to derive a preferred concept which allowed early indications of future technological direction of study. The results of the MSR SRF study by SEA (as well as the results of another parallel study) will be taken into account by ESA to define the requirements for a follow-on procurement action in the future. There will be a review of the results from both studies and an agreement on the requirements based on these parallel studies. Therefore, the views expressed herein should not be taken to reflect the official opinion of the European Space Agency.

  3. Ascorbic acid in cancer chemoprevention: translational perspectives and efficacy.

    Science.gov (United States)

    Ullah, Mohammad F; Bhat, Showket H; Hussain, Eram; Abu-Duhier, Faisel; Ahmad, Aamir; Hadi, S M

    2012-12-01

    Chemoprevention, which is referred to as the use of nontoxic natural or synthetic chemicals to intervene in multistage carcinogenesis has since decades attracted a considerable interest in plant-derived chemical constituents often termed as "phytochemicals" or sometimes as "Nutraceuticals" in case they are derived from dietary sources. A comprehensive search of the literature show that such an interest in natural product pharmacology has surged in the last 25 years and particularly risen at exponential rates since the last one decade. Phytochemicals such as curcumin (from spice turmeric), resveratrol (from red wine) and genistein (from soy) share the major efforts as indicated by overwhelming publications, despite skepticism concerning their bioavailability. Ascorbic acid (AA), the popular anti-oxidant in fruits and vegetables, has even a longer historical perspective than these dietary agents as for more than 35 years; there had been lingering questions about the efficacy of AA in cancer therapy. The footprints of AA from "scurvy" to "cancer" though complex seems to carry potential provided the puzzle could be set right. The use of AA in cancer treatment has been debated extensively as evident from the literature but surprisingly the complementing early phase bench work on the mechanistic studies for anticancer action was rather retarded. Proposed mechanisms of action for AA in the prevention and treatment of cancer includes antioxidant as well as pro-oxidant properties, stimulation of the immune system, altering carcinogen metabolism, enhancement of collagen synthesis necessary for tumor encapsulation and interference with cancer cell signaling. The observation that the intravenous administration of AA enhances its bioavailability to the extent of deriving pharmacological benefits against cancer has in recent years partially supported the clinical plausibility (efficacy) of AA towards realizing its translational advantage. Here, we provide an overview of AA with

  4. Combination chemoprevention with diclofenac, calcipotriol and difluoromethylornithine inhibits development of non-melanoma skin cancer in mice

    DEFF Research Database (Denmark)

    Pommergaard, Hans-Christian; Burcharth, Jakob; Rosenberg, Jacob

    2013-01-01

    Background/Aim: With increasing incidence of non-melanoma skin cancer (NMSC), focus on chemoprevention of this disease is growing. The aim of this study was to evaluate topical combination therapies as chemoprevention of UV radiation-induced tumors in a mouse model....

  5. Oral chemoprevention with acetyl salicylic Acid, vitamin d and calcium reduces the risk of tobacco carcinogen-induced bladder tumors in mice

    DEFF Research Database (Denmark)

    Pommergaard, Hans-Christian; Burcharth, J; Rosenberg, J

    2013-01-01

    , and diet with chemoprevention (acetyl salicylic acid, 1-alpha 25(0H)2-vitamin D3 and calcium). There were significantly fewer tumors (0 (0-0) vs. 0 (0-2), p = .045) and fewer animals with tumors (0/20 vs. 5/20, p = .045) in the chemoprevention group compared with controls. Thus, chemoprevention diet...

  6. Chemopreventive effect of Lagenaria siceraria in two stages DMBA plus croton oil induced skin papillomagenesis.

    Science.gov (United States)

    Kumar, Navneet; Kale, Raosaheb K; Tiku, Ashu B

    2013-01-01

    Cancer chemoprevention is a dietary or therapeutic strategy to prevent, suppress, or delay carcinogenesis either at initiation or progression level with nontoxic agents. Use of natural dietary compounds has been a major chemopreventive approach to modulate tumorigenic pathways. In the present study, we have evaluated Lagenaria siceraria (bottle gourd), a common vegetable of Indian household for its chemomodulatory potential. The fruit has been used in traditional medicine for a very long time for health benefits and to cure pain, ulcers, fever, cough, asthma, and other bronchial disorders. However, despite its reported beneficial effect the chemo modulatory potential of this plant has not been reported. Therefore chemopreventive effect of bottle gourd juice (BGJ) was studied against 7,12-dimethylbenz(a)anthracene (DMBA) plus croton oil induced skin papillomagenesis in Swiss albino mice. The effect was studied both at antiinitiation and antiinitiation/promotion level followed by histopathological study. A dose of 2.5% and 5% given in drinking water showed significant decrease in papilloma number, papilloma incidence, papilloma multiplicity, papilloma latency, papilloma volume, and papilloma size in different size range. Histopathological study showed chemopreventive effect by minimizing loss of stratification, a decrease in number of epithelial layers, reducing dermal infiltration and protection for various cytoplasmic changes. Higher dose of BGJ was found to be more effective than lower dose and the chemopreventive effect was maximum for antiinitiation/promotion treatment. Altogether, this study reports the chemopreventive effect of Lagenaria siceraria on skin papillomagenesis for the first time and suggests that its consumption may help in suppression of skin cancer.

  7. The Potential Role of Nitric Oxide in Halting Cancer Progression Through Chemoprevention

    Science.gov (United States)

    Vahora, Huzefa; Khan, Munawwar Ali; Alalami, Usama; Hussain, Arif

    2016-01-01

    Nitric oxide (NO) in general plays a beneficial physiological role as a vasorelaxant and the role of NO is decided by its concentration present in physiological environments. NO either facilitates cancer-promoting characters or act as an anti-cancer agent. The dilemma in this regard still remains unanswered. This review summarizes the recent information on NO and its role in carcinogenesis and tumor progression, as well as dietary chemopreventive agents which have NO-modulating properties with safe cytotoxic profile. Understanding the molecular mechanisms and cross-talk modulating NO effect by these chemopreventive agents can allow us to develop better therapeutic strategies for cancer treatment. PMID:27051643

  8. Nitrates and NO-NSAIDs in cancer chemoprevention and therapy: in vitro evidence querying the NO donor functionality.

    Science.gov (United States)

    Dunlap, Tareisha; Abdul-Hay, Samer O; Chandrasena, R Esala P; Hagos, Ghenet K; Sinha, Vaishali; Wang, Zhiqiang; Wang, Huali; Thatcher, Gregory R J

    2008-09-01

    Properties of the NO-ASA family of NO-donating NSAIDs (NO-NSAIDs), notably NCX 4016 (mNO-ASA) and NCX 4040 (pNO-ASA), reported in more than one hundred publications, have included positive preclinical data in cancer chemoprevention and therapy. Evidence is presented that the antiproliferative, the chemopreventive (antioxidant/electrophile response element (ARE) activation), and the anti-inflammatory activity of NO-ASA in cell cultures is replicated by X-ASA derivatives that are incapable of acting as NO donors. pBr-ASA and mBr-ASA are conisogenic with NO-ASA, but are not NO donors. The biological activity of pNO-ASA is replicated by pBr-ASA; and both pNO-ASA and pBr-ASA are bioactivated to the same quinone methide electrophile. The biological activity of mNO-ASA is replicated by mBr-ASA; mNO-ASA and mBr-ASA are bioactivated to different benzyl electrophiles. The observed activity is likely initiated by trapping of thiol biomolecules by the quinone and benzyl electrophiles, leading to depletion of GSH and modification of Cys-containing sensor proteins. Whereas all NO-NSAIDs containing the same structural "linker" as NCX 4040 and NCX 4016 are anticipated to possess activity resulting from bioactivation to electrophilic metabolites, this expectation does not extend to other linker structures. Nitrates require metabolic bioactivation to liberate NO bioactivity, which is often poorly replicated in vitro, and NO bioactivity provided by NO-NSAIDs in vivo provides proven therapeutic benefits in mitigation of NSAID gastrotoxicity. The in vivo properties of X-ASA drugs await discovery.

  9. Dextran sulfate sodium-induced colitis-associated neoplasia: a promising model for the development of chemopreventive interventions

    Institute of Scientific and Technical Information of China (English)

    Margie Lee CLAPPER; Harry Stanley COOPER; Wen-Chi Lee CHANG

    2007-01-01

    Individuals diagnosed with ulcerative colitis face a significantly increased risk of developing colorectal dysplasia and cancer during their lifetime. To date, little attention has been given to the development of a chemopreventive intervention for this high-risk population. The mouse model of dextran sulfate sodium (DSS) -induced colitis represents an excellent preclinical system in which to both charac-terize the molecular events required for tumor formation in the presence of inflam-marion and assess the ability of select agents to inhibit this process. Cyclic admin-istration of DSS in drinking water results in the establishment of chronic colitis and the development of colorectal dysplasias and cancers with pathological fea-tures that resemble those of human colitis-associated neoplasia. The incidence and multiplicity of lesions observed varies depending on the mouse strain used (ie, Swiss Webster, C57BL/6J, CBA, ICR) and the dose (0.7%-5.0%) and schedule (1-15 cycles with or without a subsequent recovery period) of DSS. The incidence of neoplasia can be increased and its progression to invasive cancer accelerated significantly by administering DSS in combination with a known colon carcinogen(azoxymethane (AOM), 2-amino-3-methylimidazo[4,5-f]quinoline (IQ), 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP)) or iron. More recent induction of colitis-associated neoplasia in genetically defined mouse strains has provided new insight into the role of specific genes (ie, adenomatous polyposis coli (Apc),p53, inducible nitric oxide synthase (iNOS), Msh2) in the development of colitis-associated neoplasias. Emerging data from chemopreventive intervention studies document the efficacy of several agents in inhibiting DSS-induced neoplasia and provide great promise that colitis-associated colorectal neoplasia is a pre-ventable disease.

  10. Generalized routing protocols for multihop relay networks

    KAUST Repository

    Khan, Fahd Ahmed

    2011-07-01

    Performance of multihop cooperative networks depends on the routing protocols employed. In this paper we propose the last-n-hop selection protocol, the dual path protocol, the forward-backward last-n-hop selection protocol and the forward-backward dual path protocol for the routing of data through multihop relay networks. The average symbol error probability performance of the schemes is analysed by simulations. It is shown that close to optimal performance can be achieved by using the last-n-hop selection protocol and its forward-backward variant. Furthermore we also compute the complexity of the protocols in terms of number of channel state information required and the number of comparisons required for routing the signal through the network. © 2011 IEEE.

  11. Chemoprevention of Rat Mammary Carcinogenesis by Apiaceae Spices

    Science.gov (United States)

    Aqil, Farrukh; Jeyabalan, Jeyaprakash; Munagala, Radha; Ravoori, Srivani; Vadhanam, Manicka V.; Schultz, David J.; Gupta, Ramesh C.

    2017-01-01

    Scientific evidence suggests that many herbs and spices have medicinal properties that alleviate symptoms or prevent disease. In this study, we examined the chemopreventive effects of the Apiaceae spices, anise, caraway, and celery seeds against 17β-estrogen (E2)-mediated mammary tumorigenesis in an ACI (August-Copenhagen Irish) rat model. Female ACI rats were given either control diet (AIN 93M) or diet supplemented with 7.5% (w/w) of anise, caraway, or celery seed powder. Two weeks later, one half of the animals in each group received subcutaneous silastic implants of E2. Diet intake and body weight were recorded weekly, and animals were euthanized after 3 and 12 weeks. E2-treatment showed significantly (2.1- and 3.4-fold) enhanced growth of pituitary gland at 3 and 12 weeks, respectively. All test spices significantly offset the pituitary growth by 12 weeks, except celery which was effective as early as three weeks. Immunohistochemical analysis for proliferative cell nuclear antigen (PCNA) in mammary tissues showed significant reduction in E2-mediated mammary cell proliferation. Test spices reduced the circulating levels of both E2 and prolactin at three weeks. This protection was more pronounced at 12 weeks, with celery eliciting the highest effect. RT-PCR and western blot analysis were performed to determine the potential molecular targets of the spices. Anise and caraway diets significantly offset estrogen-mediated overexpression of both cyclin D1 and estrogen receptor α (ERα). The effect of anise was modest. Likewise, expression of CYP1B1 and CYP1A1 was inhibited by all test spices. Based on short-term molecular markers, caraway was selected over other spices based on its enhanced effect on estrogen-associated pathway. Therefore, a tumor-end point study in ACI rats was conducted with dietary caraway. Tumor palpation from 12 weeks onwards revealed tumor latency of 29 days in caraway-treated animals compared with first tumor appearance at 92 days in control

  12. Chemoprevention of Rat Mammary Carcinogenesis by Apiaceae Spices

    Directory of Open Access Journals (Sweden)

    Farrukh Aqil

    2017-02-01

    Full Text Available Scientific evidence suggests that many herbs and spices have medicinal properties that alleviate symptoms or prevent disease. In this study, we examined the chemopreventive effects of the Apiaceae spices, anise, caraway, and celery seeds against 17β-estrogen (E2-mediated mammary tumorigenesis in an ACI (August-Copenhagen Irish rat model. Female ACI rats were given either control diet (AIN 93M or diet supplemented with 7.5% (w/w of anise, caraway, or celery seed powder. Two weeks later, one half of the animals in each group received subcutaneous silastic implants of E2. Diet intake and body weight were recorded weekly, and animals were euthanized after 3 and 12 weeks. E2-treatment showed significantly (2.1- and 3.4-fold enhanced growth of pituitary gland at 3 and 12 weeks, respectively. All test spices significantly offset the pituitary growth by 12 weeks, except celery which was effective as early as three weeks. Immunohistochemical analysis for proliferative cell nuclear antigen (PCNA in mammary tissues showed significant reduction in E2-mediated mammary cell proliferation. Test spices reduced the circulating levels of both E2 and prolactin at three weeks. This protection was more pronounced at 12 weeks, with celery eliciting the highest effect. RT-PCR and western blot analysis were performed to determine the potential molecular targets of the spices. Anise and caraway diets significantly offset estrogen-mediated overexpression of both cyclin D1 and estrogen receptor α (ERα. The effect of anise was modest. Likewise, expression of CYP1B1 and CYP1A1 was inhibited by all test spices. Based on short-term molecular markers, caraway was selected over other spices based on its enhanced effect on estrogen-associated pathway. Therefore, a tumor-end point study in ACI rats was conducted with dietary caraway. Tumor palpation from 12 weeks onwards revealed tumor latency of 29 days in caraway-treated animals compared with first tumor appearance at 92

  13. Development of a Real-Time PCR Protocol Requiring Minimal Handling for Detection of Vancomycin-Resistant Enterococci with the Fully Automated BD Max System.

    Science.gov (United States)

    Dalpke, Alexander H; Hofko, Marjeta; Zimmermann, Stefan

    2016-09-01

    Vancomycin-resistant enterococci (VRE) are an important cause of health care-associated infections, resulting in significant mortality and a significant economic burden in hospitals. Active surveillance for at-risk populations contributes to the prevention of infections with VRE. The availability of a combination of automation and molecular detection procedures for rapid screening would be beneficial. Here, we report on the development of a laboratory-developed PCR for detection of VRE which runs on the fully automated Becton Dickinson (BD) Max platform, which combines DNA extraction, PCR setup, and real-time PCR amplification. We evaluated two protocols: one using a liquid master mix and the other employing commercially ordered dry-down reagents. The BD Max VRE PCR was evaluated in two rounds with 86 and 61 rectal elution swab (eSwab) samples, and the results were compared to the culture results. The sensitivities of the different PCR formats were 84 to 100% for vanA and 83.7 to 100% for vanB; specificities were 96.8 to 100% for vanA and 81.8 to 97% for vanB The use of dry-down reagents and the ExK DNA-2 kit for extraction showed that the samples were less inhibited (3.3%) than they were by the use of the liquid master mix (14.8%). Adoption of a cutoff threshold cycle of 35 for discrimination of vanB-positive samples allowed an increase of specificity to 87.9%. The performance of the BD Max VRE assay equaled that of the BD GeneOhm VanR assay, which was run in parallel. The use of dry-down reagents simplifies the assay and omits any need to handle liquid PCR reagents.

  14. Sequence Patterns of Identity Authentication Protocols

    Institute of Scientific and Technical Information of China (English)

    Tao Hongcai; He Dake

    2006-01-01

    From the viewpoint of protocol sequence, analyses are made of the sequence patterns of possible identity authentication protocol under two cases: with or without the trusted third party (TTP). Ten feasible sequence patterns of authentication protocol with TTP and 5 sequence patterns without TTP are gained. These gained sequence patterns meet the requirements for identity authentication,and basically cover almost all the authentication protocols with TTP and without TTP at present. All of the sequence patterns gained are classified into unilateral or bilateral authentication. Then , according to the sequence symmetry, several good sequence patterns with TTP are evaluated. The accompolished results can provide a reference to design of new identity authentication protocols.

  15. Azoxymethane-induced rat aberrant crypt foci: Relevance in studying chemoprevention of colon cancer

    Institute of Scientific and Technical Information of China (English)

    Jayadev Raju

    2008-01-01

    The pathogenesis of colon cancer involves sequential and multistep progression of epithelial cells initiated to a cancerous state with defined precancerous intermediaries.Aberrant crypt foci (ACF) represent the earliest identifiable intermediate precancerous lesions during colon carcinogenesis in both laboratory animals and humans.ACF are easily induced by colon-specific carcinogens in rodents and can be used to learn more about the process of colon carcinogenesis.For over two decades,since its first discovery,azoxymethane(AOM)-induced rodent ACF have served as surrogate biomarkers in the screening of various anticarcinogens and carcinogens.Several dietary constituents and phytochemicals have been tested for their colon cancer chemopreventive efficacy using the ACF system.There has been substantial effort in defining and refining ACF in terms of understanding their molecular make-up,and extensive research in this field is currently in progress.In chemoprevention studies,AOM-induced rat ACF have been very successful as biomarkers,and have provided several standardized analyses of data.There have been several studies that have reported that ACF data do not correlate to actual colon tumor outcome,however,and hence there has been an ambiguity about their role as biomarkers.The scope of this mini-review is to provide valuable insights and limitations of AOM-induced rat ACF as biomarkers in colon cancer chemoprevention studies.The role of the dynamics and biological heterogeneity of ACF is critical in understanding them as biomarkers in chemoprevention studies.

  16. Chemoprevention of intestinal tumorigenesis by nabumetone: induction of apoptosis and Bcl-2 downregulation.

    Science.gov (United States)

    Roy, H K; Karoski, W J; Ratashak, A; Smyrk, T C

    2001-05-18

    Treatment of MIN mice with the nonsteroidal anti-inflammatory drug, nabumetone, resulted in a dose-dependent suppression of intestinal tumorigenesis. In both the uninvolved MIN mouse colonic epithelium and HT-29 colon cancer cells, nabumetone downregulated the anti-apoptotic protein, Bcl-2, with concomitant induction of apoptosis, suggesting a potential mechanism for colon cancer chemoprevention.

  17. A review of the content of the putative chemopreventive phytoalexin resveratrol in red wine

    DEFF Research Database (Denmark)

    Stervbo, Ulrik; Vang, Ole; Bonnesen, Christine

    2007-01-01

    Resveratrol, a naturally occurring compound of various fruits such as grapes, is thought to possess chemopreventive properties. The levels of resveratrol in grapes and grape products including wine, varies from region to region and from one year to another. This paper reviews the resveratrol...

  18. Chemoprevention of colorectal cancer by targeting APC-deficient cells for apoptosis.

    Science.gov (United States)

    Zhang, Ling; Ren, Xiaoyang; Alt, Eckhard; Bai, Xiaowen; Huang, Shaoyi; Xu, Zhengming; Lynch, Patrick M; Moyer, Mary P; Wen, Xian-Feng; Wu, Xiangwei

    2010-04-15

    Cancer chemoprevention uses natural, synthetic, or biological substances to reverse, suppress, or prevent either the initial phase of carcinogenesis or the progression of neoplastic cells to cancer. It holds promise for overcoming problems associated with the treatment of late-stage cancers. However, the broad application of chemoprevention is compromised at present by limited effectiveness and potential toxicity. To overcome these challenges, here we developed a new chemoprevention approach that specifically targets premalignant tumour cells for apoptosis. We show that a deficiency in the adenomatous polyposis coli (APC) gene and subsequent activation of beta-catenin lead to the repression of cellular caspase-8 inhibitor c-FLIP (also known as CFLAR) expression through activation of c-Myc, and that all-trans-retinyl acetate (RAc) independently upregulates tumour necrosis factor-related apoptosis-inducing ligand (TRAIL) death receptors and suppresses decoy receptors. Thus, the combination of TRAIL and RAc induces apoptosis in APC-deficient premalignant cells without affecting normal cells in vitro. In addition, we show that short-term and non-continuous TRAIL and RAc treatment induce apoptosis specifically in intestinal polyps, strongly inhibit tumour growth, and prolong survival in multiple intestinal neoplasms C57BL/6J-Apc(Min)/J (Apc(Min)) mice. With our approach, we further demonstrate that TRAIL and RAc induce significant cell death in human colon polyps, providing a potentially selective approach for colorectal cancer chemoprevention by targeting APC-deficient cells for apoptosis.

  19. Effect of a vegan diet on biomarkers of chemoprevention in females

    NARCIS (Netherlands)

    Verhagen, H.; Rauma, A.L.; Törrönen, R.; Vogel, N. de; Bruijntjes-Rozier, G.C.D.M.; Dreve, M.A.; Bogaards, J.J.P.; Mykkänen, H.

    1996-01-01

    1. In order to study the potential beneficial effects of a vegan diet, a cross-sectional study was performed and several biomarkers of chemoprevention were measured in a population of female 'living food' eaters ('vegans'; n = 20) vs matched omnivorous controls (n = 20). 2. White blood cells obtaine

  20. COX-independent mechanisms of cancer chemoprevention by anti-inflammatory drugs

    Directory of Open Access Journals (Sweden)

    Evrim eGurpinar

    2013-07-01

    Full Text Available Epidemiological and clinical studies suggest that non-steroidal anti-inflammatory drugs (NSAIDs, including cyclooxygenase (COX-2 selective inhibitors, reduce the risk of developing cancer. Experimental studies in human cancer cell lines and rodent models of carcinogenesis support these observations by providing strong evidence for the antineoplastic properties of NSAIDs. The involvement of COX-2 in tumorigenesis and its overexpression in various cancer tissues suggest that inhibition of COX-2 is responsible for the chemopreventive efficacy of these agents. However, the precise mechanisms by which NSAIDs exert their antiproliferative effects are still a matter of debate. Numerous other studies have shown that NSAIDs can act through COX-independent mechanisms. This review provides a detailed description of the major COX-independent molecular targets of NSAIDs and discusses how these targets may be involved in their anticancer effects. Toxicities resulting from COX inhibition and the suppression of prostaglandin synthesis preclude the long-term use of NSAIDs for cancer chemoprevention. Furthermore, chemopreventive efficacy is incomplete and treatment often leads to the development of resistance. Identification of alternative NSAID targets and elucidation of the biochemical processes by which they inhibit tumor growth could lead to the development of safer and more efficacious drugs for cancer chemoprevention.

  1. Dietary Pterostilbene is a novel MTA1-targeted chemopreventive and therapeutic agent in prostate cancer

    Science.gov (United States)

    Dietary nutrients with ability to reverse adverse epigenetic events have great potential for cancer chemoprevention. Overexpression of the epigenetic modifier metastasis-associated protein 1 (MTA1) is associated with aggressive human prostate cancer. The purpose of this study was to determine MTA1-d...

  2. Chemoprevention of prostate cancer: Natural compounds, antiandrogens, and antioxidants - In vivo evidence

    Directory of Open Access Journals (Sweden)

    Nur Özten-Kandas

    2011-01-01

    Full Text Available Prostate cancer is the leading non-skin malignancy detected in US males and the second cause of death due to male cancer, in the US. Interventions with drugs or diet supplements that slow down the growth and progression of prostate cancer are potentially very effective in reducing the burden of prostate cancer, particularly if these treatments also prevent the de novo development of new prostatic malignancies. Challenges to identify efficacious agents and develop them for chemopreventive application in men at risk for prostate cancer have included uncertainty about which preclinical models have the ability to predict efficacy in men and lack of consensus about which early phase clinical trial designs are the most appropriate and cost-effective to test promising agents. Efficacy studies in animal models have identified several agents with potential chemopreventive activity against prostate cancer, but few of these findings have been translated into clinical trials. This article identifies some of the major issues associated with prostate cancer chemoprevention research and summarizes the most significant current results from animal efficacy studies and human clinical prevention trials. This summary focuses on: (1 Naturally occurring agents and compounds derived from such agents, including green tea and its constituents, silibinin and milk thistle, and genistein and soy, (2 chemoprevention drugs including agents interfering with androgen action, and (3 antioxidants such as selenium, vitamin E, and lycopene. The general lack of activity of antioxidants is discussed, followed by considerations about translation of preclinical chemoprevention efficacy data, focusing on dose, form, bioavailability, and timing of administration of the agent, as well as discussion of study design of clinical trials and the predictive ability of preclinical models.

  3. Using Breast Cancer Risk Associated Polymorphisms to Identify Women for Breast Cancer Chemoprevention

    Science.gov (United States)

    Ziv, Elad; Tice, Jeffrey A.; Sprague, Brian; Vachon, Celine M.; Cummings, Steven R.; Kerlikowske, Karla

    2017-01-01

    Background Breast cancer can be prevented with selective estrogen receptor modifiers (SERMs) and aromatase inhibitors (AIs). The US Preventive Services Task Force recommends that women with a 5-year breast cancer risk ≥3% consider chemoprevention for breast cancer. More than 70 single nucleotide polymorphisms (SNPs) have been associated with breast cancer. We sought to determine how to best integrate risk information from SNPs with other risk factors to risk stratify women for chemoprevention. Methods We used the risk distribution among women ages 35–69 estimated by the Breast Cancer Surveillance Consortium (BCSC) risk model. We modeled the effect of adding 70 SNPs to the BCSC model and examined how this would affect how many women are reclassified above and below the threshold for chemoprevention. Results We found that most of the benefit of SNP testing a population is achieved by testing a modest fraction of the population. For example, if women with a 5-year BCSC risk of >2.0% are tested (~21% of all women), ~75% of the benefit of testing all women (shifting women above or below 3% 5-year risk) would be derived. If women with a 5-year risk of >1.5% are tested (~36% of all women), ~90% of the benefit of testing all women would be derived. Conclusion SNP testing is effective for reclassification of women for chemoprevention, but is unlikely to reclassify women with <1.5% 5-year risk. These results can be used to implement an efficient two-step testing approach to identify high risk women who may benefit from chemoprevention. PMID:28107349

  4. Developing security protocols in χ-Spaces

    DEFF Research Database (Denmark)

    Crazzolara, Federico; Milicia, Giuseppe

    2002-01-01

    of formal protocol verification. Verification, however, is usually carried out on an abstract model not at all related with a protocol’s implementation. Experience shows that security breaches introduced in implementations of successfully verified models are rather common. The χ-Spaces framework...... is an implementation of SPL (Security Protocol Language), a formal model for studying security protocols. In this paper we discuss the use of χ-Spaces as a tool for developing robust security protocol implementations. To make the case, we take a family of key-translation protocols due to Woo and Lam and show how χ-Spaces......It is of paramount importance that a security protocol effectively enforces the desired security requirements. The apparent simplicity of informal protocol descriptions hides the inherent complexity of their interactions which, often, invalidate informal correctness arguments and justify the effort...

  5. A Secure Short Message Communication Protocol

    Institute of Scientific and Technical Information of China (English)

    Chao-Wen Chang; Heng Pan; Hong-Yong Jia

    2008-01-01

    According to the security requirement of the short message service (SMS) industry application, a secure short message communication protocol is proposed. This is an application level protocol constructed on the standard SMS communication protocol using public key authentication and key agreement without the need of wireless public key infrastructure (WPKI). Secure short message transmission and dynamic key agreement between mobile terminals and the accessing gateway are realized. The security of the proposed protocol is validated through the BAN logic. Compared with the standard SMS protocol, the effective payload rate of our protocol can reach 91.4%, and subscriber identity module (SIM) tool kit (STK) applications based on our protocol suit well for all kinds of mobile terminals in practical application.

  6. Protocol Implementation Generator

    DEFF Research Database (Denmark)

    Carvalho Quaresma, Jose Nuno; Probst, Christian W.

    2010-01-01

    necessary tools. In this paper, we present the Protocol Implementation Generator (PiG), a framework that can be used to add protocol generation to protocol negotiation, or to easily share and implement new protocols throughout a network. PiG enables the sharing, verification, and translation...... of communication protocols. With it, partners can suggest a new protocol by sending its specification. After formally verifying the specification, each partner generates an implementation, which can then be used for establishing communication. We also present a practical realisation of the Protocol Implementation...... Generator framework based on the LySatool and a translator from the LySa language into C or Java....

  7. Improving the DGK comparison protocol

    NARCIS (Netherlands)

    Veugen, P.J.M.

    2012-01-01

    When processing signals in the encrypted domain, homomorphic encryption can be used to enable linear operations on encrypted data. Comparison of encrypted data however requires an additional protocol between the parties and will be relatively expensive. A well-known and frequently used comparison pr

  8. Prostate cancer chemoprevention in men of African descent: current state of the art and opportunities for future research.

    Science.gov (United States)

    Chornokur, Ganna; Kumar, Nagi B

    2013-08-01

    Prostate cancer is the most frequently diagnosed malignancy in men. However, African American/Black men are 60 % more likely to be diagnosed with and 2.4 times more likely to die from prostate cancer, compared to Non-Hispanic White men. Despite the increased burden of this malignancy, no evidence-based recommendation regarding prostate cancer screening exists for the high-risk population. Moreover, in addition to screening and detection, African American men may constitute a prime population for chemoprevention. Early detection and chemoprevention may thus represent an integral part of prostate cancer control in this population. Importantly, recent research has elucidated biological differences in the prostate tumors of African American compared to European American men. The latter may enable a more favorable response in African American men to specific chemopreventive agents that target relevant signal transduction pathways. Based on this evolving evidence, the aims of this review are threefold. First, we aim to summarize the biological differences that were reported in the prostate tumors of African American and European American men. Second, we will review the single- and multi-target chemopreventive agents placing specific emphasis on the pathways implicated in prostate carcinogenesis. And lastly, we will discuss the most promising nutraceutical chemopreventive compounds. Our review underscores the promise of chemoprevention in prostate cancer control, as well as provides justification for further investment in this filed to ultimately reduce prostate cancer morbidity and mortality in this high-risk population of African American men.

  9. Chemopreventive effect of the non-psychotropic phytocannabinoid cannabidiol on experimental colon cancer.

    Science.gov (United States)

    Aviello, Gabriella; Romano, Barbara; Borrelli, Francesca; Capasso, Raffaele; Gallo, Laura; Piscitelli, Fabiana; Di Marzo, Vincenzo; Izzo, Angelo A

    2012-08-01

    Colon cancer affects millions of individuals in Western countries. Cannabidiol, a safe and non-psychotropic ingredient of Cannabis sativa, exerts pharmacological actions (antioxidant and intestinal antinflammatory) and mechanisms (inhibition of endocannabinoid enzymatic degradation) potentially beneficial for colon carcinogenesis. Thus, we investigated its possible chemopreventive effect in the model of colon cancer induced by azoxymethane (AOM) in mice. AOM treatment was associated with aberrant crypt foci (ACF, preneoplastic lesions), polyps, and tumour formation, up-regulation of phospho-Akt, iNOS and COX-2 and down-regulation of caspase-3. Cannabidiol-reduced ACF, polyps and tumours and counteracted AOM-induced phospho-Akt and caspase-3 changes. In colorectal carcinoma cell lines, cannabidiol protected DNA from oxidative damage, increased endocannabinoid levels and reduced cell proliferation in a CB(1)-, TRPV1- and PPARγ-antagonists sensitive manner. It is concluded that cannabidiol exerts chemopreventive effect in vivo and reduces cell proliferation through multiple mechanisms.

  10. Chemopreventive Potential of Flavonoids in Oral Squamous Cell Carcinoma in Human Studies

    Directory of Open Access Journals (Sweden)

    Elena Maria Varoni

    2013-07-01

    Full Text Available Evidence available from nutritional epidemiology has indicated an inverse association between regular consumption of fruits and vegetables and the risk of developing certain types of cancer. In turn, preclinical studies have attributed the health-promoting effects of plant foods to some groups of phytochemicals, by virtue of their many biological activities. In this survey, we briefly examine the chemopreventive potential of flavonoids and flavonoid-rich foods in human oral carcinogenesis. Despite the paucity of data from clinical trials and epidemiological studies, in comparison to in vitro/in vivo investigations, a high level of evidence has been reported for epigallocatechin gallate (EGCG and anthocyanins. These flavonoids, abundant in green tea and black raspberries, respectively, represent promising chemopreventive agents in human oral cancer.

  11. Dietary phytochemicals and cancer chemoprevention: a review of the clinical evidence.

    Science.gov (United States)

    Kotecha, Ritesh; Takami, Akiyoshi; Espinoza, J Luis

    2016-08-09

    Cancer chemoprevention involves the use of different natural or biologic agents to inhibit or reverse tumor growth. Epidemiological and pre-clinical data suggest that various natural phytochemicals and dietary compounds possess chemopreventive properties, and in-vitro and animal studies support that these compounds may modulate signaling pathways involved in cell proliferation and apoptosis in transformed cells, enhance the host immune system and sensitize malignant cells to cytotoxic agents. Despite promising results from experimental studies, only a limited number of these compounds have been tested in clinical trials and have shown variable results. In this review, we summarize the data regarding select phytochemicals including curcumin, resveratrol, lycopene, folates and tea polyphenols with emphasis on the clinical evidence supporting the efficacy of these compounds in high-risk populations.

  12. Oxidative stress and cyclooxygenase activity in prostate carcinogenesis: targets for chemopreventive strategies.

    Science.gov (United States)

    Pathak, S K; Sharma, R A; Steward, W P; Mellon, J K; Griffiths, T R L; Gescher, A J

    2005-01-01

    Over the last decade, epidemiological, experimental and clinical studies have implicated oxidative stress in the development and progression of prostate cancer. Oxidative stress may be linked to the effects of androgens, anti-oxidant systems and the pre-malignant condition, high-grade prostatic intraepithelial neoplasia. Cyclooxygenase-2 activity has been linked with prostate carcinogenesis. Evidence suggests that oxidative stress and cyclo-oxygenase-2 activity may be mechanistically linked. Agents such as anti-oxidants and cyclo-oxgenase-2 inhibitors may be of value in the chemoprevention of prostate cancer. The feasibility of intervention with such agents will depend on the development and validation of biomarkers for clinical trials, particularly markers of oxidative damage caused by reactive oxygen species (ROS). A greater understanding of the molecular events associated with oxidative stress will enhance the development of such biomarkers and should result in better strategies for the chemoprevention of prostate cancer.

  13. Protocol Writing in Clinical Research

    Science.gov (United States)

    Al-Jundi, Azzam

    2016-01-01

    Writing a research proposal is probably one of the most challenging and difficult task as research is a new area for the majority of postgraduates and new researchers. The purpose of this article is to summarize the most important steps and necessary guidelines for producing a standard research protocol. Academic and administrative success of any project is usually determined by acquiring a grant for the related field of research. Hence, the quality of a protocol is primarily required to achieve success in this scientific competition. PMID:28050522

  14. Superposition Attacks on Cryptographic Protocols

    DEFF Research Database (Denmark)

    Damgård, Ivan Bjerre; Funder, Jakob Løvstad; Nielsen, Jesper Buus

    2011-01-01

    Attacks on classical cryptographic protocols are usually modeled by allowing an adversary to ask queries from an oracle. Security is then defined by requiring that as long as the queries satisfy some constraint, there is some problem the adversary cannot solve, such as compute a certain piece...... of information. In this paper, we introduce a fundamentally new model of quantum attacks on classical cryptographic protocols, where the adversary is allowed to ask several classical queries in quantum superposition. This is a strictly stronger attack than the standard one, and we consider the security...

  15. Chemoprevention of intestinal tumorigenesis by nabumetone: induction of apoptosis and Bcl-2 downregulation

    OpenAIRE

    Roy, H K; Karoski, W J; Ratashak, A; Smyrk, T. C.

    2001-01-01

    Treatment of MIN mice with the nonsteroidal anti-inflammatory drug, nabumetone, resulted in a dose-dependent suppression of intestinal tumorigenesis. In both the uninvolved MIN mouse colonic epithelium and HT-29 colon cancer cells, nabumetone downregulated the anti-apoptotic protein, Bcl-2, with concomitant induction of apoptosis, suggesting a potential mechanism for colon cancer chemoprevention. © 2001 Cancer Research Campaign www.bjcancer.com

  16. Population Pharmacokinetic Model for Cancer Chemoprevention With Sulindac in Healthy Subjects

    OpenAIRE

    Berg, Alexander K.; Mandrekar, Sumithra J.; Ziegler, Katie L. Allen; Carlson, Elsa C.; Szabo, Eva; Ames, Mathew M.; Boring, Daniel; Limburg, Paul J.; Reid, Joel M.

    2013-01-01

    Sulindac is a prescription-based non-steroidal anti-inflammatory drug (NSAID) that continues to be actively investigated as a candidate cancer chemoprevention agent. To further current understanding of sulindac bioavailability, metabolism, and disposition, we developed a population pharmacokinetic model for the parent compound and its active metabolites, sulindac sulfide, and exisulind. This analysis was based on data from 24 healthy subjects who participated in a bioequivalence study compari...

  17. Chemoprevention of Prostate Cancer Initiation in a Novel Transgenic Mouse Model by Targeting 15-Lipoxygenase-1

    Science.gov (United States)

    2012-02-01

    chemoprevention studies. Diets rich in either omega (ω)-3 or ω-6 polyunsaturated fatty acids ( PUFAs ) directly impact PCa tumor growth. Furthermore... acids effects on PIN development. 15. SUBJECT TERMS Diet, polyunsaturated fatty acids ( PUFAs ), 15-lipoxygenase-1, cyclooxygenase, prostate cancer...compared to FLiMP+/+ mice fed a normal diet (PIN observed) and, (3) Our study in year 2 provided mechanistic roles of omega (ω)-3 fatty acids in slowing

  18. In Vivo Testing of Chemopreventive Agents Using the Dog Model of Spontaneous Prostate Carcinogenesis

    Science.gov (United States)

    2005-03-01

    squamous cell or basal cell carcinoma , ing for smoking exposure, non-tumorous lung tissue melanoma); oropharyngeal; hepatocellular carcinoma ; of women...supplementation on cancer incidence in a randomized clinical squamous cell carcinoma of the skin in relation to plasma trial: a summary report of the...invasive carcinoma . In vivo screening of promising chemopreventive agents using the dog model of spontaneous prostate carcinogenesis represents a novel

  19. Chronic unpredictable stress deteriorates the chemopreventive efficacy of pomegranate through oxidative stress pathway.

    Science.gov (United States)

    Hasan, Shirin; Suhail, Nida; Bilal, Nayeem; Ashraf, Ghulam Md; Zaidi, Syed Kashif; AlNohair, Sultan; Banu, Naheed

    2016-05-01

    Chronic unpredictable stress (CUS) can influence the risk and progression of cancer through increased oxidative stress. Pomegranate is known to protect carcinogenesis through its anti-oxidative properties. This study is carried out to examine whether CUS affects the chemopreventive potential of pomegranate through oxidative stress pathway. Role of CUS on early stages of 7, 12 dimethyl benz(a) anthracene (DMBA) induced carcinogenesis, and its pre-exposure effect on chemopreventive efficacy of pomegranate juice (PJ) was examined in terms of in vivo antioxidant and biochemical parameters in Swiss albino rats. Rats were divided in various groups and were subjected to CUS paradigm, DMBA administration (65 mg/kg body weight, single dose), and PJ treatment. Exposure to stress (alone) and DMBA (alone) led to increased oxidative stress by significantly decreasing the antioxidant enzymes activities and altering the glutathione (GSH), malondialdehyde (MDA), glutamate oxaloacetate transaminase (GOT), and glutamate pyruvate transaminase (GPT) levels. A significant increase in DNA damage demonstrated by comet assay was seen in the liver cells. Stress exposure to DMBA-treated rats further increased the oxidative stress and disturbed the biochemical parameters as compared to DMBA (alone)-treated rats. Chemoprevention with PJ in DMBA (alone)-treated rats restored the altered parameters. However, in the pre-stress DMBA-treated rats, the overall antioxidant potential of PJ was significantly diminished. Our results indicate that chronic stress not only increases the severity of carcinogenesis but also diminishes the anti-oxidative efficacy of PJ. In a broader perspective, special emphasis should be given to stress management and healthy diet during cancer chemoprevention.

  20. Expression of Metabolic and Apoptotic Genes During Treatment With Chemopreventive Agents for Breast Cancer

    Science.gov (United States)

    2005-07-01

    Minneapolis, MN. Cancer -preventive properties of the components of cruciferous vegetables including indoles have been studied extensively. 3,3...carbinol (13C) is a product of autolysis from glucobrassicin in cruciferous vegetables . It is condensed to 3,3’-diindolylmethane (DIM) and other products in...AD Award Number: DAMD17-01-1-0332 TITLE: Expression of Metabolic and Apoptotic Genes During Treatment with Chemopreventive Agents for Breast Cancer

  1. Biomarkers in phase I–II chemoprevention trials: lessons from the NCI experience

    OpenAIRE

    Szabo, Eva

    2015-01-01

    Early phase clinical trials are an essential component of chemopreventive drug development to identify signals of drug efficacy that can subsequently be explored definitively in phase III trials. Whereas phase I trials focus on safety and identification of optimal dose and schedule for cancer prevention, phase II trials focus on intermediate endpoints that are variably related to cancer development. The United States National Cancer Institute supports a programme devoted to early phase cancer...

  2. Wireless sensors networks MAC protocols analysis

    CERN Document Server

    Chaari, Lamia

    2010-01-01

    Wireless sensors networks performance are strictly related to the medium access mechanism. An effective one, require non-conventional paradigms for protocol design due to several constraints. An adequate equilibrium between communication improvement and data processing capabilities must be accomplished. To achieve low power operation, several MAC protocols already proposed for WSN. The aim of this paper is to survey and to analyze the most energy efficient MAC protocol in order to categorize them and to compare their performances. Furthermore we have implemented some of WSN MAC protocol under OMNET++ with the purpose to evaluate their performances.

  3. Implications of cancer stem cell theory for cancer chemoprevention by natural dietary compounds.

    Science.gov (United States)

    Li, Yanyan; Wicha, Max S; Schwartz, Steven J; Sun, Duxin

    2011-09-01

    The emergence of cancer stem cell theory has profound implications for cancer chemoprevention and therapy. Cancer stem cells give rise to the tumor bulk through continuous self-renewal and differentiation. Understanding the mechanisms that regulate self-renewal is of greatest importance for discovery of anticancer drugs targeting cancer stem cells. Naturally occurring dietary compounds have received increasing attention in cancer chemoprevention. The anticancer effects of many dietary components have been reported for both in vitro and in vivo studies. Recently, a number of studies have found that several dietary compounds can directly or indirectly affect cancer stem cell self-renewal pathways. Herein we review the current knowledge of most common natural dietary compounds for their impact on self-renewal pathways and potential effect against cancer stem cells. Three pathways (Wnt/β-catenin, Hedgehog and Notch) are summarized for their functions in self-renewal of cancer stem cells. The dietary compounds, including curcumin, sulforaphane, soy isoflavone, epigallocatechin-3-gallate, resveratrol, lycopene, piperine and vitamin D(3), are discussed for their direct or indirect effect on these self-renewal pathways. Curcumin and piperine have been demonstrated to target breast cancer stem cells. Sulforaphane has been reported to inhibit pancreatic tumor-initiating cells and breast cancer stem cells. These studies provide a basis for preclinical and clinical evaluation of dietary compounds for chemoprevention of cancer stem cells. This may enable us to discover more preventive strategies for cancer management by reducing cancer resistance and recurrence and improving patient survival.

  4. Colon Cancer Chemoprevention by Sage Tea Drinking: Decreased DNA Damage and Cell Proliferation.

    Science.gov (United States)

    Pedro, Dalila F N; Ramos, Alice A; Lima, Cristovao F; Baltazar, Fatima; Pereira-Wilson, Cristina

    2016-02-01

    Salvia officinalis and some of its isolated compounds have been found to be preventive of DNA damage and increased proliferation in vitro in colon cells. In the present study, we used the azoxymethane model to test effects of S. officinalis on colon cancer prevention in vivo. The results showed that sage treatment reduced the number of ACF formed only if administered before azoxymethane injection, demonstrating that sage tea drinking has a chemopreventive effect on colorectal cancer. A decrease in the proliferation marker Ki67 and in H2 O2 -induced and azoxymethane-induced DNA damage to colonocytes and lymphocytes were found with sage treatment. This confirms in vivo the chemopreventive effects of S. officinalis. Taken together, our results show that sage treatment prevented initiation phases of colon carcinogenesis, an effect due, at least in part, to DNA protection, and reduced proliferation rates of colon epithelial cell that prevent mutations and their fixation through cell replication. These chemopreventive effects of S. officinalis on colon cancer add to the many health benefits attributed to sage and encourage its consumption.

  5. Analysis of in vitro chemoprevention of genotoxic damage by phytochemicals, as single agents or as combinations.

    Science.gov (United States)

    Abraham, Suresh K; Eckhardt, Alexander; Oli, Rajaraman G; Stopper, Helga

    2012-05-15

    Cancer chemoprevention with low-dose combinations of bioactive phytochemicals instead of single agents has been suggested to induce less toxicity and improve efficacy. In this study, we selected four plant food-based phytochemicals, viz. chlorogenic acid (CLA), pelargonidin (PEL), resveratrol (RES) and epigallocatechin gallate (EGCG) to evaluate the in vitro chemoprevention of genotoxic damage in HL-60 cells. These agents were tested either individually or as a combination at two concentrations (with a 10-fold difference) against the genotoxins mitomycin C (MMC), diepoxybutane (DEB) and patulin (PAT). Our preliminary ferric reducing antioxidant power (FRAP) assay demonstrated additive effects when PEL, CLA, RES and EGCG were combined. Results of the cytokinesis-block micronucleus test showed significant protection against genotoxic damage induced by PAT, DEB and MMC when CLA, PEL, RES and EGCG were tested individually. This protective effect of the phytochemicals was not concentration-related. Both low- and high-concentration combinations of CLA, PEL, RES and EGCG showed significant reducing effects on the frequencies of micronuclei induced by PAT, DEB and MMC. However, the micronucleus test did not provide indications of additive or synergistic effects with this combination of phytochemicals. In conclusion, the chemo-preventive effects of PEL, CLA, RES and EGCG against genotoxic damage induced by MMC, DEB and PAT are indicative of a 'saturation effect' when higher concentrations and combinations of these phytochemicals are used.

  6. Chemopreventive effect of Curcuma longa Linn on liver pathology in HBx transgenic mice.

    Science.gov (United States)

    Kim, Jungsun; Ha, Hye-Lin; Moon, Hyung-Bae; Lee, Yeon-Weol; Cho, Chong-Kwan; Yoo, Hwa-Seung; Yu, Dae-Yeul

    2011-06-01

    Unlike other forms of hepatocellular carcinoma (HCC), HCC induced by hepatitis B virus (HBV) infection shows a poor prognosis after conventional therapies. HBV induces liver cirrhosis and HCC. Many researchers have made efforts to find new substances that suppress the activity of HBV. Curcuma longa Linn (CLL) has been used for traditional medicine and food in Asia, especially in India, and has shown chemopreventive effects in a HBV-related in vitro model. This in vivo study was designed to seek the chemopreventive effects of CLL and its mechanisms. CLL mixture concentrated with dextrose water by boiling was lyophilized. CLL extracts were administrated to HBV X protein (HBx) transgenic mice aged 4 weeks for 2 to 4 weeks and aged 6 months for 3 months. After administration, histological changes in the liver tissue and expression of HBx-related genes were investigated. CLL-treated mice showed less visceral fat, a smaller liver/body weight ratio and delayed liver pathogenesis. Proliferating cell nuclear antigen (PCNA) expression was also increased in CLL-treated HBx transgenic mice, indicating regeneration of damaged liver tissue. CLL treatment decreased expression of HBx and increased p21 and cyclin D1 in livers of HBx transgenic mice. In addition, p-p53 was increased after CLL treatment. These results suggest that CLL can have beneficial effects on the early and late stages of liver pathogenesis, preventing and delaying liver carcinogenesis. This drug should be considered as a potential chemopreventive agent for HBV-related hepatocarcinogenesis.

  7. Multitargeted Low-Dose GLAD Combination Chemoprevention: A Novel and Promising Approach to Combat Colon Carcinogenesis

    Directory of Open Access Journals (Sweden)

    Altaf Mohammed

    2013-05-01

    Full Text Available Preclinical studies have shown that gefitinib, licofelone, atorvastatin, and α-difluoromethylornithine (GLAD are promising colon cancer chemopreventive agents. Because low-dose combination regimens can offer potential additive or synergistic effects without toxicity, GLAD combination was tested for toxicity and chemopreventive efficacy for suppression of intestinal tumorigenesis in adenomatous polyposis coli (APCMin/+ mice. Six-week-old wild-type and APCMin/+ mice were fed modified American Institute of Nutrition 76A diets with or without GLAD (25 + 50 + 50 + 500 ppm for 14 weeks. Dietary GLAD caused no signs of toxicity based on organ pathology and liver enzyme profiles. GLAD feeding strongly inhibited (80–83%, P 95% fewer polyps with sizes of >2 mm compared with control mice and showed 75% and 85% inhibition of colonic tumors in males and females, respectively. Molecular analyses of polyps suggested that GLAD exerts efficacy by inhibiting cell proliferation, inducing apoptosis, decreasing β-catenin and caveolin-1 levels, increasing caspase-3 cleavage and p21, and modulating expression profile of inflammatory cytokines. These observations demonstrate that GLAD, a novel cocktail of chemopreventive agents at very low doses, suppresses intestinal tumorigenesis in APCMin/+ mice with no toxicity. This novel strategy to prevent colorectal cancer is an important step in developing agents with high efficacy without unwanted side effects.

  8. Anthocyans from fruits and vegetables--does bright colour signal cancer chemopreventive activity?

    Science.gov (United States)

    Cooke, Darren; Steward, William P; Gescher, Andreas J; Marczylo, Tim

    2005-09-01

    Consumption of fruits and berries has been associated with decreased risk of developing cancer. The most abundant flavonoid constituents of fruits and berries are anthocyans (i.e. anthocyanins, glycosides, and their aglycons, anthocyanidins) that cause intense colouration. In this review, we describe epidemiological evidence hinting at the cancer preventive activity of anthocyan-containing foods in humans, results of chemoprevention studies in rodent models with anthocyans or anthocyan-containing fruit/vegetable extracts, and pharmacological properties of anthocyans. Anthocyanidins have been shown to inhibit malignant cell survival and confound many oncogenic signalling events in the 10(-6)-10(-4) M concentration range. Studies of the pharmacokinetics of anthocyanins after their consumption as single agents, anthocyanin mixtures or berry extracts suggest that anthocyanins reach levels of 10(-8)-10(-7) M in human blood. It is unclear whether such concentrations are sufficient to explain anticarcinogenic effects, and whether anthocyanins exert chemopreventive efficacy themselves, or if they need to undergo hydrolysis to their aglyconic counterparts. The currently available literature provides tantalising hints of the potential usefulness of anthocyans or anthocyan mixtures as cancer chemopreventive interventions. Nevertheless further studies are necessary to help adjudge the propitiousness of their clinical development.

  9. Research on Protocol Migration

    Institute of Scientific and Technical Information of China (English)

    汪芸; 顾冠群; 等

    1996-01-01

    This paper elaborates the concept and model of protocol migration in network interconnection.Migration strategies and principles are discussed and several cases are studied in detail which show the basic procedure and techniques used in protocol migration.

  10. Merging Multiparty Protocols in Multiparty Choreographies

    Directory of Open Access Journals (Sweden)

    Fabrizio Montesi

    2013-02-01

    Full Text Available Choreography-based programming is a powerful paradigm for defining communication-based systems from a global viewpoint. A choreography can be checked against multiparty protocol specifications, given as behavioural types, that may be instantiated indefinitely at runtime. Each protocol instance is started with a synchronisation among the involved peers. We analyse a simple transformation from a choreography with a possibly unbounded number of protocol instantiations to a choreography instantiating a single protocol, which is the merge of the original ones. This gives an effective methodology for obtaining new protocols by composing existing ones. Moreover, by removing all synchronisations required for starting protocol instances, our transformation reduces the number of communications and resources needed to execute a choreography.

  11. Topological Design of Protocols

    CERN Document Server

    Jaffe, Arthur; Wozniakowski, Alex

    2016-01-01

    We give a topological simulation for tensor networks that we call the two-string model. In this approach we give a new way to design protocols, and we discover a new multipartite quantum communication protocol. We introduce the notion of topologically compressed transformations. Our new protocol can implement multiple, non-local compressed transformations among multi-parties using one multipartite resource state.

  12. Rethinking Dosing Regimen Selection of Piperaquine for Malaria Chemoprevention: A Simulation Study.

    Directory of Open Access Journals (Sweden)

    Nancy C Sambol

    Full Text Available The combination of short-acting dihydroartemisinin and long-acting piperaquine (DP is among the first-line therapies for the treatment of uncomplicated Plasmodium falciparum malaria. Population pharmacokinetic models of piperaquine (PQ based on data from acute treatment of young children can be used to predict exposure profiles of piperaquine under different DP chemoprevention regimens. The purpose of our study was to make such predictions in young children.Based on a prior population pharmacokinetic model of PQ in young Ugandan children, we simulated capillary plasma concentration-time profiles (including their variability of candidate chemoprevention regimens for a reference population of 1-2 year olds weighing at least 11 kg. Candidate regimens that were tested included monthly administration of standard therapeutic doses, bimonthly dosing, and weekly dosing (with and without a loading dose.Once daily doses of 320 mg for three days (960 mg total at the beginning of each month are predicted to achieve an average steady-state trough capillary piperaquine concentration of 35 ng/mL, with 60% achieving a level of 30 ng/mL or higher. In contrast, weekly dosing of 320 mg (i.e., 33% higher amount per month is predicted to approximately double the average steady-state trough concentration, increase the percent of children predicted to achieve 30 ng/mL or higher (94%, while at the same time lowering peak concentrations. Exposure at steady-state, reached at approximately 3 months of multiple dosing, is expected to be approximately 2-fold higher than exposure following initial dosing, due to accumulation. A loading dose improves early exposure, thereby reducing the risk of breakthrough infections at the initiation of chemoprevention.Once weekly chemoprevention of DP predicts favourable exposures with respect to both trough and peak concentrations. These predictions need to be verified, as well as safety evaluated, in field-based clinical studies of young

  13. Similarity based mixed transaction concurrency control protocol

    Institute of Scientific and Technical Information of China (English)

    PAN Yi; LU Yan-sheng

    2005-01-01

    Due to the various performance requirements and data access restrictions of different types of real-time transactions, concurrency control protocols which had been designed for the systems with single type of transactions are not sufficient for mixed real-time database systems (MRTDBS), where different types of real-time transactions coexist in the systems concurrently. In this paper, a new concurrency control protocol MRTT_CC for mixed real-time transactions is proposed. The new strategy integrates with different concurrency control protocols to meet the deadline requirements of different types of real-time transactions. The data similarity concept is also explored in the new protocol to reduce the blocking time of soft real-time transactions, which increases their chances to meet the deadlines. Simulation experiments show that the new protocol has gained good performance.

  14. 5-aminosalicylic acid is an attractive candidate agent for chemoprevention of colon cancer in patients with inflammatory bowel disease

    Institute of Scientific and Technical Information of China (English)

    Yang Cheng; Pierre Desreumaux

    2005-01-01

    Inflammatory bowel disease (IBD) is classically subdivided into ulcerative colitis (UC) and Crohn's disease (CD). Patients with IBD have increased risk for colorectal cancer. Because the pathogenesis of colorectal carcinoma has not been entirely defined yet and there is no ideal treatment for colon cancer, cancer prevention has become increasingly important in patients with IBD. The two adopted methods to prevent the development of colon cancer in clinical practice include the prophylactic colectomy and colonoscopic surveillance.But patients and physicians seldom accept colectomy as a routine preventive method and most patients do not undergo appropriate colonoscopic surveillance. Chemoprevention refers to the use of natural or synthetic chemical agents to reverse, suppress, or to delay the process of carcinogenesis.Chemoprevention is a particularly useful method in the management of patients at high risk for the development of specific cancers based on inborn genetic susceptibility, the presence of cancer-associated disease, or other known risk factors. Prevention of colorectal cancer by administration of chemopreventive agents is one of the most promising options for IBD patients who are at increased risks of the disease. The chemopreventive efficacy of nonsteroidal antiinflammatory drugs (NSAIDs) against intestinal tumors has been well established. But with reports that NSAIDs aggravated the symptoms of colitis, their sustained use for the purpose of cancer chemoprevention has been relatively contraindicated in IBD patients. Another hopeful candidate chemoprevention drug for IBD patients is 5-aminosalicylic acid (5-ASA), which is well tolerated by most patients and has limited systemic adverse effects, and no gastrointestinal toxicity. 5-ASA lacks the well-known side effects of longterm NSAIDs use. Retrospective correlative studies have suggested that the long-term use of 5-ASA in IBD patients may significantly reduce the risk of development of colorectal cancer

  15. A formal model of fair exchange protocols

    Institute of Scientific and Technical Information of China (English)

    QING Sihan; LI Gaicheng

    2005-01-01

    Based on the study of existing fair exchange protocols, this paper sets up an accurate formal model by stepwise refinement. In the process of refinement an unreliable channel is employed to simulate an attack behavior. The model provides a novel formal definition of exchanged items, and presents the formal goals for fairness, accountability,etc., reflecting the inherent requirements for fair exchange protocols across-the-board. In order to check, prove, and design fair exchange protocols effectively and efficiently, the model puts forward a novel property of abuse-freeness which applies to all fair exchange protocols, gives a formal definition for trust strand of the third party, and presents general criteria of designing a secure and effective fair exchange protocol. Taking a typical fair exchange protocol as an example, this paper presents the analysis steps of fair exchange protocols appealing to our model. An unknown attack is uncovered. The analysis reveals the process of a complete attack, discovering deeper reasons for causing an attack.Finally, we modify the flawed protocol and the revised protocol ensures the desirable properties.

  16. Comparison of on Demand Routing Protocols

    Directory of Open Access Journals (Sweden)

    Bharat Bhushan

    2013-02-01

    Full Text Available A routing protocol is used to facilitate communication in ad hoc network. The primary goal of such a routing protocol is to provide an efficient and reliable path between a pair of nodes. The routing protocols for ad hoc network can be categorized into three categories: table driven, on demand and hybrid routing. The table driven and hybrid routing strategies require periodic exchange of hello messages between nodes of the ad hoc network and thus have high processing and bandwidth requirements. On the other hand on demand routing strategy creates routes when required and hence is very much suitable for ad hoc network. This paper therefore examines the performance of three on demand routing protocols at application layer using QualNet-5.01 simulator.

  17. Multiparty Quantum Cryptographic Protocol

    Institute of Scientific and Technical Information of China (English)

    M. Ramzan; M. K. Khan

    2008-01-01

    We propose a multiparty quantum cryptographic protocol. Unitary operators applied by Bob and Charlie, on their respective qubits of a tripartite entangled state encoding a classical symbol that can be decoded at Alice's end with the help of a decoding matrix. Eve's presence can be detected by the disturbance of the decoding matrix. Our protocol is secure against intercept-resend attacks. Furthermore, it is efficient and deterministic in the sense that two classical bits can be transferred per entangled pair of qubits. It is worth mentioning that in this protocol, the same symbol can be used for key distribution and Eve's detection that enhances the effciency of the protocol.

  18. In vitro cancer chemopreventive properties of polysaccharide extract from the brown alga, Sargassum latifolium.

    Science.gov (United States)

    Gamal-Eldeen, Amira M; Ahmed, Eman F; Abo-Zeid, Mona A

    2009-06-01

    Polysaccharides of edible algae attracted extensive interest due to their numerous biological activities. Sargassum latifolium (Turner) C. Agardh, belongs to Sargassaceae, is a brown algae in red sea shores in Egypt. This work is a novel attempt to explore the cancer chemopreventive activity of different fractions of water-soluble polysaccharide extract derived from S. latifolium. Estimation of cancer chemopreventive activity, specifically anti-initiation, including the modulation of carcinogen metabolism and the antioxidant capacity, revealed that E1 and E4 were potent anti-initiators, where they lead not only to an inhibition in the carcinogen activator cytochrome P450 1A (IC50 2.54 and 10.30 microg/ml, respectively), but also to an induction in the carcinogen detoxification enzymes glutathione-S-transferases (144% and 225% of the control, respectively). E1 and E4 inhibited 59% and 63% of the induced-DNA damage, as measured by comet assay. Similarly both E1 and E4 possessed potential anti-promoting properties as indicated by their anti-inflammatory activity. E1 and E4 enhanced the macrophage proliferation; however they dramatically inhibited the stimulated NO (30.7% and 59.3%), TNF-alpha (38.2% and 54.9) and COX-2 (20% and 18%), respectively. E3 showed a selective cytotoxicity against lymphoblastic leukemia (1301 cells), while other fraction extracts had no cytotoxic effect against all tested cell lines. E3 led to a major disturbance in cell cycle including arrest in both S-phases in 1301 cells. This disturbance was associated with an induced-cell death due to apoptosis, but not necrosis. In conclusion, E1 and E4 are promising cancer chemopreventive fractions, since they had tumor anti- initiating activity via their protective modulation of carcinogen metabolism, and tumor anti-promoting activity via their anti-inflammatory activity, while E3 can be considered as a promising anti-cancer agent against leukemia.

  19. Chemopreventive Effect of Tadalafil in Cisplatin-Induced Nephrotoxicity in Rats.

    Science.gov (United States)

    Adeneye, A A; Benebo, A S

    2016-08-30

    Nephrotoxicity remains a common untoward effect of cisplatin therapy with limited effective chemopreventive options available till date. This study aims to evaluate the possible chemopreventive effect and mechanism(s) of action of 2 mgkg-1 and 5 mgkg-1 of Tadalafil in cisplatin-induced nephrotoxic rats. In this study, twenty-five male Wistar rats were randomly divided into five groups (n = 5 rats per group) and daily pretreated with oral doses of distilled water (10 mLkg-1), ascorbic acid (100 mgkg-1), Tadalafil (2 mgkg-1 and 5 mgkg-1) for 7 days before cisplatin (5 mgkg-1, intraperitoneal) was administered. 72 hours post-cisplatin injections, rats were sacrificed humanely and blood samples for serum electrolytes, urea and creatinine and renal tissues for reduced glutathione (GSH), superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px) and malonialdehyde dehydrogenase (MAD) assays and histopathology were collected. Results showed that cisplatin injection caused significant decreases in the serum sodium (Na+), potassium (K+), bicarbonate (HCO3-), calcium (Ca2+), phosphate (PO42-) and concomitant significant increases in the serum urea and creatinine levels. In addition, there were significant decreases in the renal tissue GSH, SOD, CAT and increased MAD and GSH-Px levels which were corroborated by histopathological features of tubulonephritis. However, these histo-biochemical alterations were significantly attenuated by ascorbic acid and Tadalafil pretreatments. Overall, results of this study showed the chemopreventive potential of Tadalafil against cisplatin-induced nephrotoxicity which was possibly mediated via antioxidant and anti-lipoperoxidation mechanisms.

  20. Natural products for cancer-targeted therapy: citrus flavonoids as potent chemopreventive agents.

    Science.gov (United States)

    Meiyanto, Edy; Hermawan, Adam; Anindyajati

    2012-01-01

    Targeted therapy has been a very promising strategy of drug development research. Many molecular mechanims of diseases have been known to be regulated by abundance of proteins, such as receptors and hormones. Chemoprevention for treatment and prevention of diseases are continuously developed. Pre-clinical and clinical studies in chemoprevention field yielded many valuable data in preventing the onset of disease and suppressing the progress of their growth, making chemoprevention a challenging and a very rational strategy in future researches. Natural products being rich of flavonoids are those fruits belong to the genus citrus. Ethanolic extract of Citrus reticulata and Citrus aurantiifolia peels showed anticarcinogenic, antiproliferative, co-chemotherapeutic and estrogenic effects. Several examples of citrus flavonoids that are potential as chemotherapeutic agents are tangeretin, nobiletin, hesperetin, hesperidin, naringenin, and naringin. Those flavonoids have been shown to possess inhibition activity on certain cancer cells' growth through various mechanisms. Moreover, citrus flavonoids also perform promising effect in combination with several chemotherapeutic agents against the growth of cancer cells. Some mechanisms involved in those activities are through cell cycle modulation, antiangiogenic effect, and apoptosis induction. Previous studies showed that tangeretin suppressed the growth of T47D breast cancer cells by inhibiting ERK phosphorylation. While in combination with tamoxifen, doxorubicin, and 5-FU, respectively, it was proven to be synergist on several cancer cells. Hesperidin and naringenin increased cytotoxicitity of doxorubicin on MCF-7 cells and HeLa cells. Besides, citrus flavonoids also performed estrogenic effect in vivo. One example is hesperidin having the ability to decrease the concentration of serum and hepatic lipid and reduce osteoporosis of ovariectomized rats. Those studies showed the great potential of citrus fruits as natural product

  1. PPARγ Ligand as a Promising Candidate for Colorectal Cancer Chemoprevention: A Pilot Study

    Directory of Open Access Journals (Sweden)

    Hirokazu Takahashi

    2010-01-01

    Full Text Available Activating synthetic ligands for peroxisome proliferator-activated receptor gamma (PPARγ, such as pioglitazone, are commonly used to treat persons with diabetes mellitus with improvement of insulin resistance. Several reports have clearly demonstrated that PPARγ ligands could inhibit colorectal cancer cell growth and induce apoptosis. Meanwhile, aberrant crypt foci (ACF have come to be established as a biomarker of the risk of CRC in azoxymethane-treated mice and rats. In humans, ACF can be detected using magnifying colonoscopy. Previously, CRC and adenoma were used as a target for chemopreventive agents, but it needs a long time to evaluate, however, ACF can be a surrogate marker of CRC even for a brief period. In this clinical study, we investigated the chemopreventive effect of pioglitazone on the development of human ACF as a surrogate marker of CRC. Twenty-nine patients were divided into two groups, 20 were in the endoscopically normal control group and 9 were in the pioglitazone (15 mg/day group, and ACF and adenoma were examined before and after 1-month treatment. The number of ACF was significantly decreased (5.8±1.1 to 3.3±2.3 after 1 month of pioglitazone treatment, however, there was no significant change in the number of crypts/ACF or in the number and size of adenomas. Pioglitazone may have a clinical application as a cancer-preventive drug. This investigation is just a pilot study, therefore, further clinical studies are needed to show that the PPARγ ligand may be a promising candidate as a chemopreventive agent for colorectal carcinogenesis.

  2. Antiproliferative and cancer-chemopreventive properties of sulfated glycosylated extract derived from Leucaena leucocephala

    Directory of Open Access Journals (Sweden)

    Gamal-Eldeen Amira

    2007-01-01

    Full Text Available This work aimed to prove that simple chemical modification could provide new cancer chemopreventive and/or anticancer properties to the inactive extracted polysaccharide derived from Leucaena leucocephala . Polysaccharides were extracted from Leucaena leucocephala seeds and its 2,4-pentanedione-treated derivative (glycosylated form was prepared, which is further sulphated to give sulphated glycosylated form. Estimation of their anti-initiation activity, modulation of carcinogen metabolism, was indicated by the inhibition cytochrome P450 1A (CYP1A and the induction of glutathione-S-transferases (GSTs. Anti-proliferation activity was investigated by MTT assay against human hepatocarcinoma (HepG2, breast carcinoma (MCF-7 and lymphoblastic leukemia (1301. Apoptosis/necrosis and cell cycle were analyzed by flow cytometry. The results revealed that glycosylated form inhibited both CYP1A and GSTs, while sulphated glycosylated form not only inhibited CYP1A, but also induced the GSTs. Unlike GE, sulphated glycosylated form possessed a significant anti-proliferative activity against different cell lines. Analysis of HepG2 cell cycle phases demonstrated that glycosylated form led to a delay of G2/M-phase, while sulphated glycosylated form led to a concomitant arrest in S- and G2/M-phases. Investigation of apoptosis/necrosis ratio demonstrated that both of glycosylated form and sulphated glycosylated form induced HepG2 cell death by necrosis, but not apoptosis. Unmodified crude extract was neither active as cancer chemopreventive nor as anti-proliferative. In conclusion, chemical modification of Leucaena gum induced its cancer chemopreventive and anti-proliferative activities.

  3. Chemopreventive effect of omega-3 polyunsaturated fatty acids and atorvastatin in rats with bladder cancer.

    Science.gov (United States)

    El-Ashmawy, Nahla E; Khedr, Eman G; El-Bahrawy, Hoda A; Al-Tantawy, Samar M

    2017-02-01

    Bladder cancer remains a huge concern for the medical community because of its incidence and prevalence rates, as well as high percentage of recurrence and progression. Omega-3 polyunsaturated fatty acids and atorvastatin proved anti-inflammatory effects through peroxisome proliferator-activated receptor gamma mechanism. However, their chemopreventive effect still remained to be examined and clarified. In this study, bladder cancer was induced in rats by the chemical carcinogen N-butyl-N-(4-hydroxybutyl)nitrosamine. Omega-3 polyunsaturated fatty acids (docosahexaenoic acid and eicosapentaenoic acid: 2:3 w/w; 1200 mg/kg) and/or atorvastatin (6 mg/kg) were given orally daily to rats for eight consecutive weeks concomitantly with N-butyl-N-(4-hydroxybutyl)nitrosamine and continued for further 4 weeks after cessation of N-butyl-N-(4-hydroxybutyl)nitrosamine administration. The histopathological examination of rat bladder revealed the presence of tumors and the absence of apoptotic bodies in sections from N-butyl-N-(4-hydroxybutyl)nitrosamine group, while tumors were absent and apoptotic bodies were clearly observed in sections from rat groups treated with omega-3 polyunsaturated fatty acids, atorvastatin, or both drugs. The study of the molecular mechanisms illustrated downregulation of COX-2 and P53 (mutant) genes and suppression of transforming growth factor beta-1 and the lipid peroxidation product malondialdehyde in serum of rats of the three treated groups. This chemopreventive effect was confirmed by and associated with lower level of bladder tumor antigen in urine. However, the combined treatment with both drugs exhibited the major protective effect and nearly corrected the dyslipidemia that has been induced by N-butyl-N-(4-hydroxybutyl)nitrosamine. Collectively, omega-3 polyunsaturated fatty acids and atorvastatin, besides having anti-inflammatory properties, proved a chemopreventive effect against bladder cancer, which nominates them to be used as

  4. Cyclooxygenase as a target for chemoprevention in colorectal cancer: lost cause or a concept coming of age?

    LENUS (Irish Health Repository)

    Doherty, Glen A

    2009-02-01

    COX-2 is upregulated at an early stage in colorectal carcinogenesis and generates prostaglandins, which promote cancer cell proliferation, impair apoptosis and enhance angiogenesis, promoting tumour growth and metastasis. There are ample data from animal models and human studies to demonstrate enhanced tumour progression associated with COX-2 activity in cancer cells. Conversely, NSAIDs including aspirin inhibit COX-2 and, therefore, have anti-neoplastic properties. There has been sustained interest in COX-2 as a chemopreventive target in colorectal cancer (CRC) and although both aspirin and COX-2 selective NSAIDs have demonstrated efficacy, adverse effects have limited their widespread adoption. In particular, evidence of the cardiovascular effects of COX-2 selective inhibitors has led to questioning of the suitability of COX-2 as a target for chemoprevention. This review examines the basis for targeting COX-2 in CRC chemoprevention, evaluates the efficacy and safety of the approach and examines future strategies in this area.

  5. Pharmacoproteomic analysis reveals that metapristone (RU486 metabolite) intervenes E-cadherin and vimentin to realize cancer metastasis chemoprevention.

    Science.gov (United States)

    Yu, Suhong; Yan, Cuicui; Yang, Xingtian; He, Sudang; Liu, Jian; Qin, Chongtao; Huang, Chuanzhong; Lu, Yusheng; Tian, Zhongping; Jia, Lee

    2016-03-02

    Metapristone is the most predominant biological active metabolite of mifepristone, and being developed as a novel cancer metastasis chemopreventive agent by us. Despite its prominent metastasis chemopreventive effect, the underlying mechanism remains elusive. Our study, for the first time, demonstrated that metapristone had the ability to prevent breast cancer cells from migration, invasion, and interfere with their adhesion to endothelial cells. To explore the underlying mechanism of metapristone, we employed the iTRAQ technique to assess the effect of metapristone on MDA-MB-231 cells. In total, 5,145 proteins were identified, of which, 311 proteins showed significant differences in metapristone-treated cells compared to the control group (P-value metastasis chemoprevention is through intervening the EMT-related signaling pathways.

  6. Model Checking Data Consistency for Cache Coherence Protocols

    Institute of Scientific and Technical Information of China (English)

    Hong Pan; Hui-Min Lin; Yi Lv

    2006-01-01

    A method for automatic verification of cache coherence protocols is presented, in which cache coherence protocols are modeled as concurrent value-passing processes, and control and data consistency requirement are described as formulas in first-orderμ-calculus. A model checker is employed to check if the protocol under investigation satisfies the required properties. Using this method a data consistency error has been revealed in a well-known cache coherence protocol.The error has been corrected, and the revised protocol has been shown free from data consistency error for any data domain size, by appealing to data independence technique.

  7. An Arbitrary 2D Structured Replica Control Protocol

    OpenAIRE

    Basmadjian, Robert; Meer, Hermann,

    2011-01-01

    Traditional replication protocols that logically arrange the replicas into a specific structure have reasonable availability, lower communication cost as well as system load than those that do not require any logical organisation of replicas. We propose in this paper the A2DS protocol: a single protocol that, unlike the existing proposed protocols, can be adapted to any 2D structure. Its read operation is carried out on any replica of every level of the structure whereas write operations are ...

  8. A Model Based Security Testing Method for Protocol Implementation

    Directory of Open Access Journals (Sweden)

    Yu Long Fu

    2014-01-01

    Full Text Available The security of protocol implementation is important and hard to be verified. Since the penetration testing is usually based on the experience of the security tester and the specific protocol specifications, a formal and automatic verification method is always required. In this paper, we propose an extended model of IOLTS to describe the legal roles and intruders of security protocol implementations, and then combine them together to generate the suitable test cases to verify the security of protocol implementation.

  9. An Efficient Secure Real-Time Concurrency Control Protocol

    Institute of Scientific and Technical Information of China (English)

    XIAO Yingyuan; LIU Yunsheng; CHEN Xiangyang

    2006-01-01

    Secure real-time databases must simultaneously satisfy two requirements in guaranteeing data security and minimizing the missing deadlines ratio of transactions. However, these two requirements can conflict with each other and achieve one requirement is to sacrifice the other. This paper presents a secure real-time concurrency control protocol based on optimistic method. The concurrency control protocol incorporates security constraints in a real-time optimistic concurrency control protocol and makes a suitable tradeoff between security and real-time requirements by introducing secure influence factor and real-time influence factor. The experimental results show the concurrency control protocol achieves data security without degrading real-time performance significantly.

  10. Spacelab system analysis: The modified free access protocol: An access protocol for communication systems with periodic and Poisson traffic

    Science.gov (United States)

    Ingels, Frank; Owens, John; Daniel, Steven

    1989-01-01

    The protocol definition and terminal hardware for the modified free access protocol, a communications protocol similar to Ethernet, are developed. A MFA protocol simulator and a CSMA/CD math model are also developed. The protocol is tailored to communication systems where the total traffic may be divided into scheduled traffic and Poisson traffic. The scheduled traffic should occur on a periodic basis but may occur after a given event such as a request for data from a large number of stations. The Poisson traffic will include alarms and other random traffic. The purpose of the protocol is to guarantee that scheduled packets will be delivered without collision. This is required in many control and data collection systems. The protocol uses standard Ethernet hardware and software requiring minimum modifications to an existing system. The modification to the protocol only affects the Ethernet transmission privileges and does not effect the Ethernet receiver.

  11. A Chemopreventive Trial to Study the Effects of High Tea Consumption on Smoking-Related Oxidative Stress

    Science.gov (United States)

    2006-02-01

    479.76 583.65 425.47 448.57 n 127 43 42 42 f) Determination of each subiect’s baseline history of smoking, diet and tea intake, plasma catechins ...AD Award Number: DAMD17-03-1-0053 TITLE: A Chemopreventive Trial to Study the Effects of High Tea Consumption on Smoking-Related Oxidative Stress...2006 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER A Chemopreventive Trial to Study the Effects of High Tea Consumption on Smoking- 5b. GRANT NUMBER Related

  12. Acceptability by community health workers in Senegal of combining community case management of malaria and seasonal malaria chemoprevention

    DEFF Research Database (Denmark)

    Tine, Roger Ck; Ndiaye, Pascal; Ndour, Cheikh T;

    2013-01-01

    Community case management of malaria (CCMm) and seasonal malaria chemoprevention (SMC) are anti-malarial interventions that can lead to substantial reduction in malaria burden acting in synergy. However, little is known about the social acceptability of these interventions. A study was undertaken...... to assess whether combining the interventions would be an acceptable approach to malaria control for community health workers (CHWs).......Community case management of malaria (CCMm) and seasonal malaria chemoprevention (SMC) are anti-malarial interventions that can lead to substantial reduction in malaria burden acting in synergy. However, little is known about the social acceptability of these interventions. A study was undertaken...

  13. Improvement In MAODV Protocol Using Location Based Routing Protocol

    Directory of Open Access Journals (Sweden)

    Kaur Sharnjeet

    2016-01-01

    Full Text Available Energy saving is difficult in wireless sensor network (WSN due to limited resources. Each node in WSN is constrained by their limited battery power for their energy. The energy is reduced as the time goes off due to the packet transmission and reception. Energy management techniques are necessary to minimize the total power consumption of all the nodes in the network in order to maximize its life span. Our proposed protocol Location based routing (LBR aimed to find a path which utilizes the minimum energy to transmit the packets between the source and the destination. The required energy for the transmission and reception of data is evaluated in MATLAB. LBR is implemented on Multicast Ad hoc On Demand Distance Vector Routing Protocol (MAODV to manage the energy consumption in the transmission and reception of data. Simulation results of LBR show the energy consumption has been reduced.

  14. Transport Protocol Throughput Fairness

    Directory of Open Access Journals (Sweden)

    Saleem Bhatti

    2009-11-01

    Full Text Available Interest continues to grow in alternative transport protocols to the Transmission Control Protocol (TCP. These alternatives include protocols designed to give greater efficiency in high-speed, high-delay environments (so-called high-speed TCP variants, and protocols that provide congestion control without reliability. For the former category, along with the deployed base of ‘vanilla’ TCP – TCP NewReno – the TCP variants BIC and CUBIC are widely used within Linux: for the latter category, the Datagram Congestion Control Protocol (DCCP is currently on the IETF Standards Track. It is clear that future traffic patterns will consist of a mix of flows from these protocols (and others. So, it is important for users and network operators to be aware of the impact that these protocols may have on users. We show the measurement of fairness in throughput performance of DCCP Congestion Control ID 2 (CCID2 relative to TCP NewReno, and variants Binary Increase Congestion control (BIC, CUBIC and Compound, all in “out-of-the box” configurations. We use a testbed and endto- end measurements to assess overall throughput, and also to assess fairness – how well these protocols might respond to each other when operating over the same end-to-end network path. We find that, in our testbed, DCCP CCID2 shows good fairness with NewReno, while BIC, CUBIC and Compound show unfairness above round-trip times of 25ms.

  15. Identification of cancer chemopreventive isothiocyanates as direct inhibitors of the arylamine N-acetyltransferase-dependent acetylation and bioactivation of aromatic amine carcinogens

    Science.gov (United States)

    Duval, Romain; Xu, Ximing; Bui, Linh-Chi; Mathieu, Cécile; Petit, Emile; Cariou, Kevin; Dodd, Robert H.; Dupret, Jean-Marie; Rodrigues-Lima, Fernando

    2016-01-01

    Aromatic amines (AAs) are chemicals of industrial, pharmacological and environmental relevance. Certain AAs, such as 4-aminobiphenyl (4-ABP), are human carcinogens that require enzymatic metabolic activation to reactive chemicals to form genotoxic DNA adducts. Arylamine N-acetyltransferases (NAT) are xenobiotic metabolizing enzymes (XME) that play a major role in this carcinogenic bioactivation process. Isothiocyanates (ITCs), including benzyl-ITC (BITC) and phenethyl-ITC (PEITC), are phytochemicals known to have chemopreventive activity against several aromatic carcinogens. In particular, ITCs have been shown to modify the bioactivation and subsequent mutagenicity of carcinogenic AA chemicals such as 4-ABP. However, the molecular and biochemical mechanisms by which these phytochemicals may modulate AA carcinogens bioactivation and AA-DNA damage remains poorly understood. This manuscript provides evidence indicating that ITCs can decrease the metabolic activation of carcinogenic AAs via the irreversible inhibition of NAT enzymes and subsequent alteration of the acetylation of AAs. We demonstrate that BITC and PEITC react with NAT1 and inhibit readily its acetyltransferase activity (ki = 200 M−1.s−1 and 66 M−1.s−1 for BITC and PEITC, respectively). Chemical labeling, docking approaches and substrate protection assays indicated that inhibition of the acetylation of AAs by NAT1 was due to the chemical modification of the enzyme active site cysteine. Moreover, analyses of AAs acetylation and DNA adducts in cells showed that BITC was able to modulate the endogenous acetylation and bioactivation of 4-ABP. In conclusion, we show that direct inhibition of NAT enzymes may be an important mechanism by which ITCs exert their chemopreventive activity towards AA chemicals. PMID:26840026

  16. Coded Splitting Tree Protocols

    DEFF Research Database (Denmark)

    Sørensen, Jesper Hemming; Stefanovic, Cedomir; Popovski, Petar

    2013-01-01

    This paper presents a novel approach to multiple access control called coded splitting tree protocol. The approach builds on the known tree splitting protocols, code structure and successive interference cancellation (SIC). Several instances of the tree splitting protocol are initiated, each...... instance is terminated prematurely and subsequently iterated. The combined set of leaves from all the tree instances can then be viewed as a graph code, which is decodable using belief propagation. The main design problem is determining the order of splitting, which enables successful decoding as early...... as possible. Evaluations show that the proposed protocol provides considerable gains over the standard tree splitting protocol applying SIC. The improvement comes at the expense of an increased feedback and receiver complexity....

  17. INEEL AIR MODELING PROTOCOL ext

    Energy Technology Data Exchange (ETDEWEB)

    C. S. Staley; M. L. Abbott; P. D. Ritter

    2004-12-01

    Various laws stemming from the Clean Air Act of 1970 and the Clean Air Act amendments of 1990 require air emissions modeling. Modeling is used to ensure that air emissions from new projects and from modifications to existing facilities do not exceed certain standards. For radionuclides, any new airborne release must be modeled to show that downwind receptors do not receive exposures exceeding the dose limits and to determine the requirements for emissions monitoring. For criteria and toxic pollutants, emissions usually must first exceed threshold values before modeling of downwind concentrations is required. This document was prepared to provide guidance for performing environmental compliance-driven air modeling of emissions from Idaho National Engineering and Environmental Laboratory facilities. This document assumes that the user has experience in air modeling and dose and risk assessment. It is not intended to be a "cookbook," nor should all recommendations herein be construed as requirements. However, there are certain procedures that are required by law, and these are pointed out. It is also important to understand that air emissions modeling is a constantly evolving process. This document should, therefore, be reviewed periodically and revised as needed. The document is divided into two parts. Part A is the protocol for radiological assessments, and Part B is for nonradiological assessments. This document is an update of and supersedes document INEEL/INT-98-00236, Rev. 0, INEEL Air Modeling Protocol. This updated document incorporates changes in some of the rules, procedures, and air modeling codes that have occurred since the protocol was first published in 1998.

  18. Analysis of Enhanced Associativity Based Routing Protocol

    Directory of Open Access Journals (Sweden)

    Said A. Shaar

    2006-01-01

    Full Text Available This study introduces an analysis to the performance of the Enhanced Associativity Based Routing protocol (EABR based on two factors; Operation complexity (OC and Communication Complexity (CC. OC can be defined as the number of steps required in performing a protocol operation, while CC can be defined as the number of messages exchanged in performing a protocol operation[1]. The values represent the worst-case analysis. The EABR has been analyzed based on CC and OC and the results have been compared with another routing technique called ABR. The results have shown that EABR can perform better than ABR in many circumstances during the route reconstruction.

  19. Mutual Authentication Protocols for RFID Systems

    Institute of Scientific and Technical Information of China (English)

    Ashrar A. Omer; Johnson P. Thomas; Ling Zhu

    2008-01-01

    With the availability of low-cost radio frequency identification (RFID) tags, security becomes an increasing concern.However, such tags do not permit complex eryptographic functions due to their computational, communications, and storage limitations.In this paper, we investigate the security issues and requirements of RFID systems, and propose ultra-light weight and light weight protocols for low-cost RFID tags. The proposed protocols has been applied to a supply chain management system.

  20. OAuth protocol for CERN Web Applications

    OpenAIRE

    Kleszcz, Emil; Rodriguez Fernandez, Luis; Marescaux, Nicolas Bernard

    2016-01-01

    Project Specification The CERN Authentication service has recently increased his offer of SSO protocols/frameworks with OAuth2 standard. The purpose of the work is to explain the need for an authorization standard and explain how does OAuth2 protocol addresses our requirements. OAuth is an open standard for authorization which provides a secure access to server resources that belongs to a user. As a wide known and relatively new standard (2012) is used by big players in the industry a...

  1. Field Monitoring Protocol: Heat Pump Water Heaters

    Energy Technology Data Exchange (ETDEWEB)

    Sparn, B.; Earle, L.; Christensen, D.; Maguire, J.; Wilson, E.; Hancock, E.

    2013-02-01

    This document provides a standard field monitoring protocol for evaluating the installed performance of Heat Pump Water Heaters in residential buildings. The report is organized to be consistent with the chronology of field test planning and execution. Research questions are identified first, followed by a discussion of analysis methods, and then the details of measuring the required information are laid out. A field validation of the protocol at a house near the NREL campus is included for reference.

  2. Field Monitoring Protocol. Heat Pump Water Heaters

    Energy Technology Data Exchange (ETDEWEB)

    Sparn, B. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Earle, L. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Christensen, D. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Maguire, J. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Wilson, E. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Hancock, C. E. [Mountain Energy Partnership, Longmont, CO (United States)

    2013-02-01

    This document provides a standard field monitoring protocol for evaluating the installed performance of Heat Pump Water Heaters in residential buildings. The report is organized to be consistent with the chronology of field test planning and execution. Research questions are identified first, followed by a discussion of analysis methods, and then the details of measuring the required information are laid out. A field validation of the protocol at a house near the NREL campus is included for reference.

  3. Tea: age-old beverage as an effective cancer chemopreventive agent

    Directory of Open Access Journals (Sweden)

    Jasmine George

    2011-12-01

    Full Text Available Cancer is the major public health problem, causing approximately 7 million deaths every year worldwide. The existing treatment approaches and surgical techniques have not been able to cope effectively with this dreaded disease. Because of this, the concept of chemoprevention is now considered a valid approach to reduce the incidence of cancer. There is convincing epidemiological and experimental evidence to show that dietary polyphenolic plant-derived compounds have cancer preventive properties. Based on evidence from in vitro, in vivo data and epidemiological studies, tea has received considerable attention over recent years for reducing the risk of several cancers. Much of the cancer preventive effects of tea, and in particular green tea, appear to be mediated by the polyphenols they contain. In addition to inhibiting mutagenesis and proliferation, tea is relatively non-toxic, is low cost, and can be taken orally or as a part of the daily diet. Therefore it is logical that future clinical studies should focus on examining the efficacy of tea and its active constituents, such as epigallocatechin- 3-gallate (EGCG and theaflavins (TFs, in chemoprevention as an alternative to pharmacological agents. In this review, we address the use of tea and its constituents for the prevention and treatment of cancer. Further mechanistic and dose-response studies will help us to understand the effects of tea consumption on human carcinogenesis.

  4. Chemoprevention of skin cancer using low HLB surfactant nanoemulsion of 5-fluorouracil: a preliminary study.

    Science.gov (United States)

    Shakeel, Faiyaz; Haq, Nazrul; Al-Dhfyan, Abdullah; Alanazi, Fars K; Alsarra, Ibrahim A

    2015-01-01

    Oral delivery of 5-fluorouracil (5-FU) is difficult due to its serious adverse effects and extremely low bioavailability. Therefore, the aim of present investigation was to develop and evaluate low HLB surfactant nanoemulsion of 5-FU for topical chemoprevention of skin cancer. Low HLB surfactant nanoemulsions were prepared by oil phase titration method. Thermodynamically stable nanoemulsions were characterized in terms of droplet size distribution, zeta potential, viscosity and refractive index. Selected formulations and control were subjected to in vitro skin permeation studies through rat skin using Franz diffusion cells. Optimized formulation F9 was subjected to stability and in vitro cytotoxic studies on melanoma cell lines. Enhancement ratio was found to be 22.33 in formulation F9 compared with control and other formulations. The values of steady state flux and permeability coefficient for formulation F9 were found to be 206.40 ± 14.56 µg cm(-2) h(-1) and 2.064 × 10(-2) ± 0.050 × 10(-2 )cm h(-1), respectively. Optimized formulation F9 was found to be physical stable. In vitro cytotoxicity studies on SK-MEL-5 cancer cells indicated that 5-FU in optimized nanoemulsion is much more efficacious than free 5-FU. From these results, it can be concluded that the developed nanoemulsion might be a promising vehicle for chemoprevention of skin cancer.

  5. Clinical cancer chemoprevention: From the hepatitis B virus (HBV) vaccine to the human papillomavirus (HPV) vaccine.

    Science.gov (United States)

    Tsai, Horng-Jyh

    2015-04-01

    Approximately 2 million new cancer cases are attributed to infectious agents each year worldwide. Vaccines for the hepatitis B virus (HBV), a risk factor of hepatocellular cancer, and human papillomavirus (HPV), a risk factor of cervical cancer, are considered major successes in clinical chemoprevention of cancer. In Taiwan, the first evidence of cancer prevention through vaccinations was provided by HBV vaccination data in infants. The Taiwanese HBV vaccination program has since become a model immunization schedule for newborns worldwide. Persistent infection with high-risk HPV is generally accepted as prerequisite for cervical cancer diagnosis; however, cervical cancer is a rare complication of HPV infections. This is due to the fact that such infections tend to be transient. The safety and efficacy of both available HPV quadrivalent vaccine and bivalent vaccine are not in doubt at the present time. Until a human cytomegalovirus (CMV) vaccine becomes available, simple hygienic practices, such as hand washing, can prevent CMV infection both before and during pregnancy. Each country should establish her official guidelines regarding which vaccines should be used to treat various conditions, the target population (i.e., universal or limited to a selected population), and the immunization schedules. After a vaccine is recommended, decisions regarding reimbursement by the public health care fund are evaluated. The guidelines become part of the immunization schedule, which is updated annually and published in the official bulletin. In conclusion, both HBV and HPV vaccines are considered major successes in the chemoprevention of cancer.

  6. Cancer chemopreventive activity of diversin from Ferula diversivittata in vitro and in vivo.

    Science.gov (United States)

    Iranshahi, M; Sahebkar, A; Hosseini, S T; Takasaki, M; Konoshima, T; Tokuda, H

    2010-03-01

    A prenylated coumarin (diversin, 1) together with four new sesquiterpene lactones (diversolides A, D, F and G, 2-5) isolated from the roots of Ferula diversivittata were studied for their possible inhibitory effects on Epstein-Barr virus early antigen (EBV-EA) activation induced by 12-O-tetradecanoylphorbol-13-acetate (TPA). All of the tested compounds were active against EBV-EA activation. Among these compounds diversin (IC(50): 7.7) exhibited the strongest inhibitory effect and was selected to examine its effects on in vivo two-stage mouse skin carcinogenesis induced by 7,12-dimethylbenz[a]anthracene (DMBA) as initiator and TPA as promoter. Treatment with compound 1 (85nmol) along with DMBA/TPA inhibited papilloma formation up to week 7 and the percentage of papilloma bearers was approximately 93.3% at week 20. The average number of papillomas formed per mouse was only 5.5 even at week 20. The results of the present investigation indicated that diversin might be valuable as a potent cancer chemopreventive agent and its potency was comparable with those of curcumin and quercetin, two well-known cancer chemopreventive agents.

  7. Cancer chemoprevention activity of labdane diterpenes from rhizomes of Hedychium coronarium

    Directory of Open Access Journals (Sweden)

    Denise C. Endringer

    2014-08-01

    Full Text Available Hedychium coronarium J. Koenig, Zingiberaceae, is a medicinal plant popularly used to treat inflammatory conditions in different countries. Three labdane diterpenes [isocoronarin D (1, methoxycoronarin D (2, ethoxycoronarin D (3] and benzoyl eugenol (4 were isolated from rhizomes and their chemopreventive potential was evaluated using in vitro assays, namely the inhibition of NF-κB, COX-1 and -2, the induction of antioxidant response element (ARE, and the inhibition of cell proliferation. Diterpene 1 activated ARE (EC50 57.6 ± 2.4 µM, while 2, 3 and 4 significantly inhibited NF-κB (IC50 of 7.3 ± 0.3, 3.2 ± 0.3 and 32.5 ± 4.9 µM, respectively. In addition, 2 and 3 selectively inhibited COX-1 (IC50 values of 0.9 ± 0.0 and 3.8 ± 0.0 µM, respectively. These data support the potential chemopreventive activity of constituents from H. coronarium rhizomes.

  8. Population pharmacokinetic model for cancer chemoprevention with sulindac in healthy subjects.

    Science.gov (United States)

    Berg, Alexander K; Mandrekar, Sumithra J; Ziegler, Katie L Allen; Carlson, Elsa C; Szabo, Eva; Ames, Mathew M; Boring, Daniel; Limburg, Paul J; Reid, Joel M

    2013-04-01

    Sulindac is a prescription-based non-steroidal anti-inflammatory drug (NSAID) that continues to be actively investigated as a candidate cancer chemoprevention agent. To further current understanding of sulindac bioavailability, metabolism, and disposition, we developed a population pharmacokinetic model for the parent compound and its active metabolites, sulindac sulfide, and exisulind. This analysis was based on data from 24 healthy subjects who participated in a bioequivalence study comparing two formulations of sulindac. The complex disposition of sulindac and its metabolites was described by a seven-compartment model featuring enterohepatic recirculation and is the first reported population pharmacokinetic model for sulindac. The derived model was used to explore effects of clinical variables on sulindac pharmacokinetics and revealed that body weight, creatinine clearance, and gender were significantly correlated with pharmacokinetic parameters. Moreover, the model quantifies the relative bioavailability of the sulindac formulations and illustrates the utility of population pharmacokinetics in bioequivalence assessment. This novel population pharmacokinetic model provides new insights regarding the factors that may affect the pharmacokinetics of sulindac and the exisulind and sulindac sulfide metabolites in generally healthy subjects, which have implications for future chemoprevention trial design for this widely available agent.

  9. Nutrient and nonnutrient components of legumes, and its chemopreventive activity: a review.

    Science.gov (United States)

    Sánchez-Chino, Xariss; Jiménez-Martínez, Cristian; Dávila-Ortiz, Gloria; Álvarez-González, Isela; Madrigal-Bujaidar, Eduardo

    2015-01-01

    Legumes in combination with other products are the staple food for a large part of the world population, especially the low-income fragment, because their seeds provide valuable amounts of carbohydrates, fiber, and proteins, and have an important composition of essential amino acids, the sulphured amino acids being the limiting ones. Furthermore, legumes also have nonnutritional compounds that may decrease the absorption of nutrients or produce toxic effects; however, it has been reported that depending on the dose, these nonnutritional compounds also have different bioactivities as antioxidant, hypolipidemic, hypoglycemic, and anticarcinogenic agents, which have been proven in scientific studies. It has been observed that in countries with a high consumption of legumes, the incidence of colorectal cancer is lower. Some studies have shown that legume seeds are an alternative chemopreventive therapy against various cancers especially colon; this was verified in various animal models of induced by azoxymethane, a colon specific carcinogenic compound, in which a diet was supplemented with different concentrations of beans, lentils, chickpeas, or soybeans, mostly. These studies have proven the anticancer activity of legumes in early stages of carcinogenesis. Therefore, it is important to review the information available to elucidate the chemopreventive mechanisms of action of legume compounds.

  10. Chemopreventive effect of PSP through targeting of prostate cancer stem cell-like population.

    Science.gov (United States)

    Luk, Sze-Ue; Lee, Terence Kin-Wah; Liu, Ji; Lee, Davy Tak-Wing; Chiu, Yung-Tuen; Ma, Stephanie; Ng, Irene Oi-Lin; Wong, Yong-Chuan; Chan, Franky Leung; Ling, Ming-Tat

    2011-01-01

    Recent evidence suggested that prostate cancer stem/progenitor cells (CSC) are responsible for cancer initiation as well as disease progression. Unfortunately, conventional therapies are only effective in targeting the more differentiated cancer cells and spare the CSCs. Here, we report that PSP, an active component extracted from the mushroom Turkey tail (also known as Coriolus versicolor), is effective in targeting prostate CSCs. We found that treatment of the prostate cancer cell line PC-3 with PSP led to the down-regulation of CSC markers (CD133 and CD44) in a time and dose-dependent manner. Meanwhile, PSP treatment not only suppressed the ability of PC-3 cells to form prostaspheres under non-adherent culture conditions, but also inhibited their tumorigenicity in vivo, further proving that PSP can suppress prostate CSC properties. To investigate if the anti-CSC effect of PSP may lead to prostate cancer chemoprevention, transgenic mice (TgMAP) that spontaneously develop prostate tumors were orally fed with PSP for 20 weeks. Whereas 100% of the mice that fed with water only developed prostate tumors at the end of experiment, no tumors could be found in any of the mice fed with PSP, suggesting that PSP treatment can completely inhibit prostate tumor formation. Our results not only demonstrated the intriguing anti-CSC effect of PSP, but also revealed, for the first time, the surprising chemopreventive property of oral PSP consumption against prostate cancer.

  11. In Vitro Chemopreventive Properties of Green Tea, Rooibos and Honeybush Extracts in Skin Cells

    Directory of Open Access Journals (Sweden)

    Tandeka U. Magcwebeba

    2016-11-01

    Full Text Available The chemopreventive properties of the herbal teas rooibos (Aspalathus linearis and honeybush (Cyclopia spp. have been demonstrated on mouse skin in vivo but the underlying mechanisms are not clear. The aim of the current study was to determine the anti-proliferative and pro-apoptotic activity of methanol and aqueous extracts of rooibos and two Cyclopia species in different skin cells, using green tea (Camellia sinensis as a benchmark. Extracts were also characterised for their major individual polyphenols by high performance liquid chromatography and spectroscopically for the total polyphenol (TP groups. The methanol extract of rooibos, containing higher levels of polyphenols than its aqueous extract, displayed similar activity to green tea as it selectively targeted premalignant cells by inhibiting cell proliferation at lower concentrations whilst inducing apoptosis via membrane depolarisation at higher concentrations. Specific roles of the major rooibos dihydrochalcones and flavanol/proanthocyanidin-type (FLAVA compounds are likely to be involved. The aqueous extracts of the Cyclopia species were more active against cell proliferation and at inducing apoptosis which was associated with a higher FLAVA content and a reduced TP/FLAVA ratio. In contrast, their methanol extracts exhibited a cytoprotective effect against apoptosis which was related to their monomeric xanthone and flavanone content. The underlying chemopreventive properties of green tea and the herbal teas appear to be associated with diverse and complex monomeric/polymeric polyphenolic cell interactions.

  12. The chemopreventive bioflavonoid apigenin modulates signal transduction pathways in keratinocyte and colon carcinoma cell lines.

    Science.gov (United States)

    Van Dross, Rukiyah; Xue, Yue; Knudson, Alexandra; Pelling, Jill C

    2003-11-01

    Apigenin is a nonmutagenic chemopreventive agent found in fruits and green vegetables. In this study, we used two different epithelial cell lines (308 mouse keratinocytes and HCT116 colon carcinoma cells) to determine the effect of apigenin on the mitogen-activated protein kinase (MAPK) cascade. Apigenin induced a dose-dependent phosphorylation of both extracellular signal-regulated protein kinase (ERK) and p38 kinase but had little effect on the phosphorylation of c-jun amino terminal kinase (JNK). We used immunoprecipitation-coupled kinase assays to show that apigenin increased the kinase activity of ERK and p38 but not JNK. Consistent with these results, we found that apigenin induced a 7.4-fold induction in the phosphorylation of Elk, the downstream phosphorylation target of ERK kinase. Similarly, apigenin induced a 3.2-fold induction in the phosphorylation of activating transcription factor-2, the downstream phosphorylation target of p38 kinase. Little change was observed in the phosphorylation of c-jun, the phosphorylation target of JNK. These data suggest that part of the chemopreventive activity of apigenin may be mediated by its ability to modulate the MAPK cascade.

  13. Benzo(a)pyrene induced lung cancer: Role of dietary phytochemicals in chemoprevention.

    Science.gov (United States)

    Kasala, Eshvendar Reddy; Bodduluru, Lakshmi Narendra; Barua, Chandana C; Sriram, Chandra Shekhar; Gogoi, Ranadeep

    2015-10-01

    Lung cancer is the major cause of overall cancer deaths, and chemoprevention is a promising strategy to control this disease. Benzo(a)pyrene [B(a)P], a polycyclic aromatic hydrocarbon, is one among the principal constituents of tobacco smoke that plays a key role in lung carcinogenesis. The B(a)P induced lung cancer in mice offers a relevant model to study the effect of natural products and has been widely used by many researchers and found considerable success in ameliorating the pathophysiological changes of lung cancer. Currently available synthetic drugs that constitute the pharmacological armamentarium are themselves effective in managing the condition but not without setbacks. These hunches have accelerated the requisite for natural products, which may be used as dietary supplement to prevent the progress of lung cancer. Besides, these agents also supplement the conventional treatment and offer better management of the condition with less side effects. In the context of soaring interest toward dietary phytochemicals as newer pharmacological interventions for lung cancer, in the present review, we are attempting to give a silhouette of mechanisms of B(a)P induced lung carcinogenesis and the role of dietary phytochemicals in chemoprevention.

  14. Kioto protocol; Protocolo de Kioto

    Energy Technology Data Exchange (ETDEWEB)

    Romero, A.

    2005-07-01

    Atmospheric contamination by greenhouse gases is a global problem, and thus its solution requires global measures. Although the consequences of climate change are questioned and the foreseeable effects are not excessively serious, there are plenty of scientific reasons for all countries to make the necessary efforts to meet the objectives established by the Kyoto Protocol of reducing the six greenhouse gases over the period 2008-2012. Therefore, it seems essential that we understand the nature of the transformation that are occurring in the different systems, what changes they are causing and what costs they incur. Independently of its effectiveness and realism, the Kyoto Protocol is the first regulatory step in the direction of globalization in the environmental field. (Author)

  15. Chapter 14: Chiller Evaluation Protocol

    Energy Technology Data Exchange (ETDEWEB)

    Tiessen, A.

    2014-09-01

    This protocol defines a chiller measure as a project that directly impacts equipment within the boundary of a chiller plant. A chiller plant encompasses a chiller--or multiple chillers--and associated auxiliary equipment. This protocol primarily covers electric-driven chillers and chiller plants. It does not include thermal energy storage and absorption chillers fired by natural gas or steam, although a similar methodology may be applicable to these chilled water system components. Chillers provide mechanical cooling for commercial, institutional, multiunit residential, and industrial facilities. Cooling may be required for facility heating, ventilation, and air conditioning systems or for process cooling loads (e.g., data centers, manufacturing process cooling). The vapor compression cycle, or refrigeration cycle, cools water in the chilled water loop by absorbing heat and rejecting it to either a condensing water loop (water cooled chillers) or to the ambient air (air-cooled chillers).

  16. IPv6 Protocol Analyzer

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    With the emerging of next generation Intemet protocol (IPv6), it is expected to replace the current version of Internet protocol (IPv4) that will be exhausted in the near future. Besides providing adequate address space, some other new features are included into the new 128 bits of IP such as IP auto configuration, quality of service, simple routing capability, security, mobility and multicasting. The current protocol analyzer will not be able to handle IPv6 packets. This paper will focus on developing protocol analyzer that decodes IPv6 packet. IPv6 protocol analyzer is an application module,which is able to decode the IPv6 packet and provide detail breakdown of the construction of the packet. It has to understand the detail construction of the IPv6, and provide a high level abstraction of bits and bytes of the IPv6 packet.Thus it increases network administrators' understanding of a network protocol,helps he/she in solving protocol related problem in a IPv6 network environment.

  17. Playing With Population Protocols

    Directory of Open Access Journals (Sweden)

    Xavier Koegler

    2009-06-01

    Full Text Available Population protocols have been introduced as a model of sensor networks consisting of very limited mobile agents with no control over their own movement: A collection of anonymous agents, modeled by finite automata, interact in pairs according to some rules. Predicates on the initial configurations that can be computed by such protocols have been characterized under several hypotheses. We discuss here whether and when the rules of interactions between agents can be seen as a game from game theory. We do so by discussing several basic protocols.

  18. Linear Logical Voting Protocols

    DEFF Research Database (Denmark)

    DeYoung, Henry; Schürmann, Carsten

    2012-01-01

    . In response, we promote linear logic as a high-level language for both specifying and implementing voting protocols. Our linear logical specifications of the single-winner first-past-the-post (SW- FPTP) and single transferable vote (STV) protocols demonstrate that this approach leads to concise......Current approaches to electronic implementations of voting protocols involve translating legal text to source code of an imperative programming language. Because the gap between legal text and source code is very large, it is difficult to trust that the program meets its legal specification...... implementations that closely correspond to their legal specification, thereby increasing trust....

  19. New Enlightenment of Skin Cancer Chemoprevention through Phytochemicals: In Vitro and In Vivo Studies and the Underlying Mechanisms.

    Science.gov (United States)

    Singh, Madhulika; Suman, Shankar; Shukla, Yogeshwer

    2014-01-01

    Skin cancer is still a major cause of morbidity and mortality worldwide. Skin overexposure to ultraviolet irradiations, chemicals, and several viruses has a capability to cause severe skin-related disorders including immunosuppression and skin cancer. These factors act in sequence at various steps of skin carcinogenesis via initiation, promotion, and/or progression. These days cancer chemoprevention is recognized as the most hopeful and novel approach to prevent, inhibit, or reverse the processes of carcinogenesis by intervention with natural products. Phytochemicals have antioxidant, antimutagenic, anticarcinogenic, and carcinogen detoxification capabilities thereby considered as efficient chemopreventive agents. Considerable efforts have been done to identify the phytochemicals which may possibly act on one or several molecular targets that modulate cellular processes such as inflammation, immunity, cell cycle progression, and apoptosis. Till date several phytochemicals in the light of chemoprevention have been studied by using suitable skin carcinogenic in vitro and in vivo models and proven as beneficial for prevention of skin cancer. This revision presents a comprehensive knowledge and the main molecular mechanisms of actions of various phytochemicals in the chemoprevention of skin cancer.

  20. New Enlightenment of Skin Cancer Chemoprevention through Phytochemicals: In Vitro and In Vivo Studies and the Underlying Mechanisms

    Directory of Open Access Journals (Sweden)

    Madhulika Singh

    2014-01-01

    Full Text Available Skin cancer is still a major cause of morbidity and mortality worldwide. Skin overexposure to ultraviolet irradiations, chemicals, and several viruses has a capability to cause severe skin-related disorders including immunosuppression and skin cancer. These factors act in sequence at various steps of skin carcinogenesis via initiation, promotion, and/or progression. These days cancer chemoprevention is recognized as the most hopeful and novel approach to prevent, inhibit, or reverse the processes of carcinogenesis by intervention with natural products. Phytochemicals have antioxidant, antimutagenic, anticarcinogenic, and carcinogen detoxification capabilities thereby considered as efficient chemopreventive agents. Considerable efforts have been done to identify the phytochemicals which may possibly act on one or several molecular targets that modulate cellular processes such as inflammation, immunity, cell cycle progression, and apoptosis. Till date several phytochemicals in the light of chemoprevention have been studied by using suitable skin carcinogenic in vitro and in vivo models and proven as beneficial for prevention of skin cancer. This revision presents a comprehensive knowledge and the main molecular mechanisms of actions of various phytochemicals in the chemoprevention of skin cancer.

  1. Breaking the relay in deregulated cellular signal transduction as a rationale for chemoprevention with anti-inflammatory phytochemicals

    Energy Technology Data Exchange (ETDEWEB)

    Kundu, Joydeb Kumar [National Research Laboratory of Molecular Carcinogenesis and Chemoprevention, College of Pharmacy, Seoul National University, Shinlim-dong, Kwanak-gu, Seoul 151-742 (Korea, Republic of); Surh, Young-Joon [National Research Laboratory of Molecular Carcinogenesis and Chemoprevention, College of Pharmacy, Seoul National University, Shinlim-dong, Kwanak-gu, Seoul 151-742 (Korea, Republic of)]. E-mail: surh@plaza.snu.ac.kr

    2005-12-11

    Center to the cancer biology is disrupted intracellular signaling network, which transmits improper signals resulting in abnormal cellular functioning. Therefore, modulation of inappropriate cell signaling cascades might be a rational approach in achieving chemoprevention. Inflammation has long been suspected to contribute to carcinogenesis. A new horizon in chemoprevention research is the recent discovery of molecular links between inflammation and cancer. Components of the cell signaling network, especially those converge on redox-sensitive transcription factor nuclear factor-{kappa}B involved in mediating inflammatory response, have been implicated in carcinogenesis. Intracellular signaling through another redox-sensitive transcription factor AP-1 and that transmitted via a more recently identified oncoprotein {beta}-catenin are also considered to be crucial for inflammation-associated cancer. Epidemiological and experimental studies have revealed that a wide variety of phytochemicals present in our daily diet are potential chemopreventive agents that can alter or correct undesired cellular functions caused by abnormal pro-inflammatory signal transmission. Modulation of cellular signaling involved in chronic inflammatory response by anti-inflammatory phytochemicals may comprise a rational and pragmatic strategy in molecular target-based chemoprevention.

  2. Chemoprevention activity of 25-hydroxyvitamin D in the MMTV-PyMT mouse model of breast cancer

    Science.gov (United States)

    Development of oncologic conditions is often linked to inadequate vitamin D status. The chemoprevention ability of this molecule is of high interest for breast cancer, the most common malignancy in women worldwide. Current effective vitamin D analogs including the naturally occurring active metabol...

  3. 1996 : Track Count Protocol

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The goal of St. Vincent National Wildlife Refuge's Track Count Protocol is to provide an index to the population size of game animals inhabiting St. Vincent Island.

  4. Unconditionally Secure Protocols

    DEFF Research Database (Denmark)

    Meldgaard, Sigurd Torkel

    the secure computation. Especially we look at the communication complexity of protocols in this model, and perfectly secure protocols. We show general protocols for any finite functionality with statistical security and optimal communication complexity (but exponential amount of preprocessing). And for two......This thesis contains research on the theory of secure multi-party computation (MPC). Especially information theoretically (as opposed to computationally) secure protocols. It contains results from two main lines of work. One line on Information Theoretically Secure Oblivious RAMS, and how...... they are used to speed up secure computation. An Oblivious RAM is a construction for a client with a small $O(1)$ internal memory to store $N$ pieces of data on a server while revealing nothing more than the size of the memory $N$, and the number of accesses. This specifically includes hiding the access pattern...

  5. Efficient Privacy Preserving Protocols for Similarity Join

    Directory of Open Access Journals (Sweden)

    Bilal Hawashin

    2012-04-01

    Full Text Available During the similarity join process, one or more sources may not allow sharing its data with other sources. In this case, a privacy preserving similarity join is required. We showed in our previous work [4] that using long attributes, such as paper abstracts, movie summaries, product descriptions, and user feedbacks, could improve the similarity join accuracy using supervised learning. However, the existing secure protocols for similarity join methods can not be used to join sources using these long attributes. Moreover, the majority of the existing privacy‐preserving protocols do not consider the semantic similarities during the similarity join process. In this paper, we introduce a secure efficient protocol to semantically join sources when the join attributes are long attributes. We provide two secure protocols for both scenarios when a training set exists and when there is no available training set. Furthermore, we introduced the multi‐label supervised secure protocol and the expandable supervised secure protocol. Results show that our protocols can efficiently join sources using the long attributes by considering the semantic relationships among the long string values. Therefore, it improves the overall secure similarity join performance.

  6. USA-USSR protocol

    CERN Multimedia

    1970-01-01

    On 30 November the USA Atomic Energy Commission and the USSR State Committee for the Utilization of Atomic Energy signed, in Washington, a protocol 'on carrying out of joint projects in the field of high energy physics at the accelerators of the National Accelerator Laboratory (Batavia) and the Institute for High Energy Physics (Serpukhov)'. The protocol will be in force for five years and can be extended by mutual agreement.

  7. Statins in the chemoprevention of colorectal cancer in established animal models of sporadic and colitis-associated cancer.

    Science.gov (United States)

    Pikoulis, Emmanouil; Margonis, Georgios A; Angelou, Anastasios; Zografos, George C; Antoniou, Efstathios

    2016-03-01

    Despite the availability of effective surveillance for colorectal cancer with colonoscopy, chemoprevention might be an acceptable alternative. Statins are potent inhibitors of cholesterol biosynthesis. In clinical trials, statins have been found to be beneficial in the primary and secondary prevention of coronary heart disease. However, the overall benefits observed with statins appear to be greater than what might be expected from changes in lipid levels alone, suggesting effects beyond cholesterol lowering. This systematic review aimed to gather information on the possible chemopreventive role of statins in preventing carcinogenesis and tumor promotion by a diverse array of mechanisms in both sporadic and colitis-associated cancer in animal models. The MEDLINE database was thoroughly searched using the following keywords: 'statin, HMG-CoA reductase inhibitor, colon cancer, mice, rats, chemoprevention, colitis-associated cancer'. Additional articles were gathered and evaluated. There are a lot of clinical studies and meta-analyses, as well as a plethora of basic research studies implementing cancer cell lines and animal models, on the chemopreventive role of statins in colorectal cancer (CRC). However, data derived from clinical studies are inconclusive, yet they show a tendency toward a beneficial role of statins against CRC pathogenesis. Thus, more research on the molecular pathways of CRC tumorigenesis as related to statins is warranted to uncover new mechanisms and compare the effect of statins on both sporadic and colitis-associated cancer in animal models. Basic science results could fuel exclusive colitis-associated cancer clinical trials to study the chemopreventive effects of statins and to differentiate between their effects on the two types of CRCs in humans.

  8. Kaiware Daikon (Raphanus sativus L.) extract: a naturally multipotent chemopreventive agent.

    Science.gov (United States)

    Barillari, Jessica; Iori, Renato; Papi, Alessio; Orlandi, Marina; Bartolini, Giovanna; Gabbanini, Simone; Pedulli, Gian Franco; Valgimigli, Luca

    2008-09-10

    Brassica vegetables are attracting major attention as healthy foods because of their content of glucosinolates (GLs) that release the corresponding isothiocyanates (ITCs) upon myrosinase hydrolysis. A number of studies have so far documented the chemopreventive properties of some ITCs. On the other hand, single nutrients detached from the food itself risk being somewhat "reductive", since plants contain several classes of compounds endowed with a polyhedral mechanism of action. Our recent finding that 4-methylthio-3-butenyl isothiocyanate (GRH-ITC) and 4-methylsulfinyl-3-butenyl isothiocyanate (GRE-ITC), released by the GLs purified from Japanese (Kaiware) Daikon (Raphanus sativus L.) seeds and sprouts, had selective cytotoxic/apoptotic activity on three human colon carcinoma cell lines prompted further research on the potential chemopreventive role of a standardized Kaiware Daikon extract (KDE), containing 10.5% w/w GRH and 3.8% w/w GRE, compared to its isolated components. KDE administered in combination with myrosinase at doses corresponding to 50 microM GRH-ITC plus 15 microM GRE-ITC (50 microM KDE-ITC) to three human cancer cell lines (LoVo, HCT-116 and HT-29) significantly reduced cell growth by 94-96% of control in six days (p GRH-ITC or GRE-ITC at the same dose. On the other hand, the same treatment had no significant toxicity on normal human T-lymphocytes. A 50 microM concentration of KDE-ITC had relevant apoptosis induction in all tested cancer cell lines, as confirmed by annexin V assay (e.g., 33% induction in LoVo compared to control, p GRH or GRH-ITC, KDE also had significant chain-breaking antioxidant activity, retarding the AAPH-initiated autoxidation of methyl linoleate in SDS micelles at concentrations as low as 4.4 ppm (-50% in oxygen consumption rate), as monitored by Clark-type microelectrode oxygen-uptake kinetics, and induced very fast quenching of DPPH. radical in methanol with t(1/2) (s) = (1.47 +/- 0.25) x 10(-2)/[KDE; (g/L)], measured by

  9. Successful and not so successful chemoprevention of tobacco smoke-induced lung tumors.

    Science.gov (United States)

    Witschi, H

    2000-12-01

    Strain A/J mice underwent whole body exposure for 6 hours a day, 5 days a week, for 5 months to a mixture of cigarette sidestream and mainstream smoke (89%-11%; total suspended particulates 80-150 mg/m3), then were kept for another 4 months in air before being killed for scoring of lung tumors. In 7 independent experiments, lung tumor multiplicity was significantly increased in all 7 trials and lung tumor incidence in 5. When animals were kept for 9 months in smoke, lung tumor multiplicity was not significantly higher than in controls, although lung tumor incidence was. The following chemopreventive agents were evaluated: green tea, phenethyl isothiocyanate (PEITC), acetylsalicylic acid (ASA), N-acetylcysteine (NAC), p-XSC (1,4-phenylenebis[methylene]selenocyanate), d-limonene (DL), and a mixture of PEITC and BITC (benzyl isothiocyanate). In animals exposed to tobacco smoke, none of these agents reduced lung tumor multiplicity or incidence. As a control, the effects of the same agents were examined in A/J mice initiated with 4-(methylnitrosamino)-1-(3pyridyl)-1-butanone (NNK) or urethane. In mice injected with NNK, green tea and ASA did not reduce lung tumor multiplicities and NAC had no effect on urethane-induced lung tumors, whereas PEITC, p-XSC and DL reduced NNK-induced tumor multiplicities to 20% to 50% of control values. On the other hand, dietary mixture of myoinositol and dexamethasone was not only highly protective against NNK, but reduced lung tumor multiplicities and incidence in smoke-exposed animals to control values. This effect was also seen when the animals were fed the myo-inositol-dexamethasone mixture once they were removed from smoke. It is concluded that in animal studies it might be preferable to evaluate the effectiveness of putative chemopreventive agents against full tobacco smoke rather than against selected model compounds. The observations made with myo-inositol-dexamethasone suggest that people who have recently quit smoking might

  10. Probabilistic Model--Checking of Quantum Protocols

    CERN Document Server

    Gay, S; Papanikolaou, N; Gay, Simon; Nagarajan, Rajagopal; Papanikolaou, Nikolaos

    2005-01-01

    We establish fundamental and general techniques for formal verification of quantum protocols. Quantum protocols are novel communication schemes involving the use of quantum-mechanical phenomena for representation, storage and transmission of data. As opposed to quantum computers, quantum communication systems can and have been implemented using present-day technology; therefore, the ability to model and analyse such systems rigorously is of primary importance. While current analyses of quantum protocols use a traditional mathematical approach and require considerable understanding of the underlying physics, we argue that automated verification techniques provide an elegant alternative. We demonstrate these techniques through the use of PRISM, a probabilistic model-checking tool. Our approach is conceptually simpler than existing proofs, and allows us to disambiguate protocol definitions and assess their properties. It also facilitates detailed analyses of actual implemented systems. We illustrate our techniqu...

  11. Cancer Chemoprevention Effects of Ginger and its Active Constituents: Potential for New Drug Discovery.

    Science.gov (United States)

    Wang, Chong-Zhi; Qi, Lian-Wen; Yuan, Chun-Su

    2015-01-01

    Ginger is a commonly used spice and herbal medicine worldwide. Besides its extensive use as a condiment, ginger has been used in traditional Chinese medicine for the management of various medical conditions. In recent years, ginger has received wide attention due to its observed antiemetic and anticancer activities. This paper reviews the potential role of ginger and its active constituents in cancer chemoprevention. The phytochemistry, bioactivity, and molecular targets of ginger constituents, especially 6-shogaol, are discussed. The content of 6-shogaol is very low in fresh ginger, but significantly higher after steaming. With reported anti-cancer activities, 6-shogaol can be served as a lead compound for new drug discovery. The lead compound derivative synthesis, bioactivity evaluation, and computational docking provide a promising opportunity to identify novel anticancer compounds originating from ginger.

  12. Esophageal cancer: The latest on chemoprevention and state of the art therapies.

    Science.gov (United States)

    Le Bras, Gregoire F; Farooq, Muhammad H; Falk, Gary W; Andl, Claudia D

    2016-11-01

    Esophageal cancer is currently the 8th most common cancer worldwide and the 6th leading cause of cancer-related mortality. Despite remarkable advances, the mortality for those suffering from esophageal cancer remains high, with 5-year survival rates of less than 20%. In part, because most patients present with late-stage disease, long-term survival even after resection and therapy is disappointingly low. As we will discuss in this review, multiple characteristics specific to the disease stage and patient must be considered when choosing a treatment plan. This article will summarize current standard therapies, potential application of chemoprevention drugs and the promise and partial failure of personalized medicine, as well as novel treatments addressing this disease.

  13. Bladder urotoxicity pathophysiology induced by the oxazaphosphorine alkylating agents and its chemoprevention 

    Directory of Open Access Journals (Sweden)

    Łukasz Dobrek

    2012-09-01

    Full Text Available The use of oxazaphosphorines (cyclophosphamide, ifosfamide in the treatment of numerous neoplastic disorders is associated with their essential adverse effect in the form of hemorrhagic cystitis, which considerably limits the safety and efficacy of their pharmacotherapy. HC is a complex inflammatory response, induced by toxic oxazaphosphorines metabolite – acrolein with subsequent immunocompetetive cells activation and release of many proinflammatory agents. However, there are some chemoprotectant agents which help reduce the HC exacerbation.The article briefly discuses the mechanism of action of oxazaphosphorines, the pathophysiology of the hemorrhagic cystitis development and currently accepted chemopreventive agents, applied to the objective of urotoxicity amelioration. Moreover, the rationale for some phytopharmaceuticals administration as novel bladder protective compounds accompanying cyclophosphamide or ifosfamide therapy was also mentioned. 

  14. Preclinical Cancer Chemoprevention Studies Using Animal Model of Inflammation-Associated Colorectal Carcinogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Tanaka, Takuji [Cytopatholgy Division, Tohkai Cytopathology Institute, Cancer Research and Prevention (TCI-CaRP), 5-1-2 Minami-uzura, Gifu 500-8285 (Japan); Department of Tumor Pathology, Gifu University Graduate School of Medicine, 1-1 Yanagido, Gifu 501-1194 (Japan)

    2012-07-16

    Inflammation is involved in all stages of carcinogenesis. Inflammatory bowel disease, such as ulcerative colitis and Crohn’s disease is a longstanding inflammatory disease of intestine with increased risk for colorectal cancer (CRC). Several molecular events involved in chronic inflammatory process are reported to contribute to multi-step carcinogenesis of CRC in the inflamed colon. They include over-production of free radicals, reactive oxygen and nitrogen species, up-regulation of inflammatory enzymes in arachidonic acid biosynthesis pathway, up-regulation of certain cytokines, and intestinal immune system dysfunction. In this article, firstly I briefly introduce our experimental animal models where colorectal neoplasms rapidly develop in the inflamed colorectum. Secondary, data on preclinical cancer chemoprevention studies of inflammation-associated colon carcinogenesis by morin, bezafibrate, and valproic acid, using this novel inflammation-related colorectal carcinogenesis model is described.

  15. Fresh garlic extract inhibits Staphylococcus aureus biofilm formation under chemopreventive and chemotherapeutic conditions

    Directory of Open Access Journals (Sweden)

    Panan Ratthawongjirakul

    2016-08-01

    Full Text Available Staphylococcus aureus and methicillin-resistant Staphylococcus aureus (MRSA are the leading aetiological pathogens of nosocomial infections worldwide. These bacteria form biofilms on both biotic and abiotic surfaces causing biofilm-associated infections. Within the biofilm, these bacteria might develop persistent and antimicrobial resistant characteristics resulting in chronic infections and treatment failures. Garlic exhibits broad pharmaceutical properties and inhibitory activities against S. aureus. We investigated the effects of aqueous fresh garlic extract on biofilm formation in S. aureus ATCC25923 and MRSA strains under chemopreventive and chemotherapeutic conditions. The viable bacteria and biofilm levels were quantified through colony count and crystal violet staining, respectively. The use of fresh garlic extract under both conditions significantly inhibited biofilm formation in S. aureus strains ATCC25923 and MRSA. Garlic could be developed as either a prophylactic or therapeutic agent to manage S. aureus biofilm-associated infections.

  16. The Chemopreventive Phytochemical Moringin Isolated from Moringa oleifera Seeds Inhibits JAK/STAT Signaling

    Science.gov (United States)

    Weigl, Julia; De Nicola, Gina Rosalinda; Canistro, Donatella; Paolini, Moreno; Iori, Renato; Rascle, Anne

    2016-01-01

    Sulforaphane (SFN) and moringin (GMG-ITC) are edible isothiocyanates present as glucosinolate precursors in cruciferous vegetables and in the plant Moringa oleifera respectively, and recognized for their chemopreventive and medicinal properties. In contrast to the well-studied SFN, little is known about the molecular pathways targeted by GMG-ITC. We investigated the ability of GMG-ITC to inhibit essential signaling pathways that are frequently upregulated in cancer and immune disorders, such as JAK/STAT and NF-κB. We report for the first time that, similarly to SFN, GMG-ITC in the nanomolar range suppresses IL-3-induced expression of STAT5 target genes. GMG-ITC, like SFN, does not inhibit STAT5 phosphorylation, suggesting a downstream inhibitory event. Interestingly, treatment with GMG-ITC or SFN had a limited inhibitory effect on IFNα-induced STAT1 and STAT2 activity, indicating that both isothiocyanates differentially target JAK/STAT signaling pathways. Furthermore, we showed that GMG-ITC in the micromolar range is a more potent inhibitor of TNF-induced NF-κB activity than SFN. Finally, using a cellular system mimicking constitutive active STAT5-induced cell transformation, we demonstrated that SFN can reverse the survival and growth advantage mediated by oncogenic STAT5 and triggers cell death, therefore providing experimental evidence of a cancer chemopreventive activity of SFN. This work thus identified STAT5, and to a lesser extent STAT1/STAT2, as novel targets of moringin. It also contributes to a better understanding of the biological activities of the dietary isothiocyanates GMG-ITC and SFN and further supports their apparent beneficial role in the prevention of chronic illnesses such as cancer, inflammatory diseases and immune disorders. PMID:27304884

  17. The DNA base excision repair protein Ape1/Ref-1 as a therapeutic and chemopreventive target.

    Science.gov (United States)

    Fishel, Melissa L; Kelley, Mark R

    2007-01-01

    With our growing understanding of the pathways involved in cell proliferation and signaling, targeted therapies, in the treatment of cancer are entering the clinical arena. New and emerging targets are proteins involved in DNA repair pathways. Inhibition of various proteins in the DNA repair pathways sensitizes cancer cells to DNA damaging agents such as chemotherapy and/or radiation. We study the apurinic endonuclease 1/redox factor-1 (Ape1/Ref-1) and believe that its crucial function in DNA repair and reduction-oxidation or redox signaling make it an excellent target for sensitizing tumor cells to chemotherapy. Ape1/Ref-1 is an essential enzyme in the base excision repair (BER) pathway which is responsible for the repair of DNA caused by oxidative and alkylation damage. As importantly, Ape1/Ref-1 also functions as a redox factor maintaining transcription factors in an active reduced state. Ape1/Ref-1 stimulates the DNA binding activity of numerous transcription factors that are involved in cancer promotion and progression such as AP-1 (Fos/Jun), NFkappaB, HIF-1alpha, CREB, p53 and others. We will discuss what is known regarding the pharmacological targeting of the DNA repair activity, as well as the redox activity of Ape1/Ref-1, and explore the budding clinical utility of inhibition of either of these functions in cancer treatment. A brief discussion of the effect of polymorphisms in its DNA sequence is included because of Ape1/Ref-1's importance to maintenance and integrity of the genome. Experimental modification of Ape1/Ref-1 activity changes the response of cells and of organisms to DNA damaging agents, suggesting that Ape1/Ref-1 may also be a productive target of chemoprevention. In this review, we will provide an overview of Ape1/Ref-1's activities and explore the potential of this protein as a target in cancer treatment as well as its role in chemoprevention.

  18. The Chemopreventive Phytochemical Moringin Isolated from Moringa oleifera Seeds Inhibits JAK/STAT Signaling.

    Directory of Open Access Journals (Sweden)

    Carina Michl

    Full Text Available Sulforaphane (SFN and moringin (GMG-ITC are edible isothiocyanates present as glucosinolate precursors in cruciferous vegetables and in the plant Moringa oleifera respectively, and recognized for their chemopreventive and medicinal properties. In contrast to the well-studied SFN, little is known about the molecular pathways targeted by GMG-ITC. We investigated the ability of GMG-ITC to inhibit essential signaling pathways that are frequently upregulated in cancer and immune disorders, such as JAK/STAT and NF-κB. We report for the first time that, similarly to SFN, GMG-ITC in the nanomolar range suppresses IL-3-induced expression of STAT5 target genes. GMG-ITC, like SFN, does not inhibit STAT5 phosphorylation, suggesting a downstream inhibitory event. Interestingly, treatment with GMG-ITC or SFN had a limited inhibitory effect on IFNα-induced STAT1 and STAT2 activity, indicating that both isothiocyanates differentially target JAK/STAT signaling pathways. Furthermore, we showed that GMG-ITC in the micromolar range is a more potent inhibitor of TNF-induced NF-κB activity than SFN. Finally, using a cellular system mimicking constitutive active STAT5-induced cell transformation, we demonstrated that SFN can reverse the survival and growth advantage mediated by oncogenic STAT5 and triggers cell death, therefore providing experimental evidence of a cancer chemopreventive activity of SFN. This work thus identified STAT5, and to a lesser extent STAT1/STAT2, as novel targets of moringin. It also contributes to a better understanding of the biological activities of the dietary isothiocyanates GMG-ITC and SFN and further supports their apparent beneficial role in the prevention of chronic illnesses such as cancer, inflammatory diseases and immune disorders.

  19. The Chemopreventive Phytochemical Moringin Isolated from Moringa oleifera Seeds Inhibits JAK/STAT Signaling.

    Science.gov (United States)

    Michl, Carina; Vivarelli, Fabio; Weigl, Julia; De Nicola, Gina Rosalinda; Canistro, Donatella; Paolini, Moreno; Iori, Renato; Rascle, Anne

    2016-01-01

    Sulforaphane (SFN) and moringin (GMG-ITC) are edible isothiocyanates present as glucosinolate precursors in cruciferous vegetables and in the plant Moringa oleifera respectively, and recognized for their chemopreventive and medicinal properties. In contrast to the well-studied SFN, little is known about the molecular pathways targeted by GMG-ITC. We investigated the ability of GMG-ITC to inhibit essential signaling pathways that are frequently upregulated in cancer and immune disorders, such as JAK/STAT and NF-κB. We report for the first time that, similarly to SFN, GMG-ITC in the nanomolar range suppresses IL-3-induced expression of STAT5 target genes. GMG-ITC, like SFN, does not inhibit STAT5 phosphorylation, suggesting a downstream inhibitory event. Interestingly, treatment with GMG-ITC or SFN had a limited inhibitory effect on IFNα-induced STAT1 and STAT2 activity, indicating that both isothiocyanates differentially target JAK/STAT signaling pathways. Furthermore, we showed that GMG-ITC in the micromolar range is a more potent inhibitor of TNF-induced NF-κB activity than SFN. Finally, using a cellular system mimicking constitutive active STAT5-induced cell transformation, we demonstrated that SFN can reverse the survival and growth advantage mediated by oncogenic STAT5 and triggers cell death, therefore providing experimental evidence of a cancer chemopreventive activity of SFN. This work thus identified STAT5, and to a lesser extent STAT1/STAT2, as novel targets of moringin. It also contributes to a better understanding of the biological activities of the dietary isothiocyanates GMG-ITC and SFN and further supports their apparent beneficial role in the prevention of chronic illnesses such as cancer, inflammatory diseases and immune disorders.

  20. Inhibition of Akt Enhances the Chemopreventive Effects of Topical Rapamycin in Mouse Skin.

    Science.gov (United States)

    Dickinson, Sally E; Janda, Jaroslav; Criswell, Jane; Blohm-Mangone, Karen; Olson, Erik R; Liu, Zhonglin; Barber, Christy; Petricoin, Emanuel F; Calvert, Valerie S; Einspahr, Janine; Dickinson, Jesse E; Stratton, Steven P; Curiel-Lewandrowski, Clara; Saboda, Kathylynn; Hu, Chengcheng; Bode, Ann M; Dong, Zigang; Alberts, David S; Timothy Bowden, G

    2016-03-01

    The PI3Kinase/Akt/mTOR pathway has important roles in cancer development for multiple tumor types, including UV-induced nonmelanoma skin cancer. Immunosuppressed populations are at increased risk of aggressive cutaneous squamous cell carcinoma (SCC). Individuals who are treated with rapamycin (sirolimus, a classical mTOR inhibitor) have significantly decreased rates of developing new cutaneous SCCs compared with those that receive traditional immunosuppression. However, systemic rapamycin use can lead to significant adverse events. Here, we explored the use of topical rapamycin as a chemopreventive agent in the context of solar-simulated light (SSL)-induced skin carcinogenesis. In SKH-1 mice, topical rapamycin treatment decreased tumor yields when applied after completion of 15 weeks of SSL exposure compared with controls. However, applying rapamycin during SSL exposure for 15 weeks, and continuing for 10 weeks after UV treatment, increased tumor yields. We also examined whether a combinatorial approach might result in more significant tumor suppression by rapamycin. We validated that rapamycin causes increased Akt (S473) phosphorylation in the epidermis after SSL, and show for the first time that this dysregulation can be inhibited in vivo by a selective PDK1/Akt inhibitor, PHT-427. Combining rapamycin with PHT-427 on tumor prone skin additively caused a significant reduction of tumor multiplicity compared with vehicle controls. Our findings indicate that patients taking rapamycin should avoid sun exposure, and that combining topical mTOR inhibitors and Akt inhibitors may be a viable chemoprevention option for individuals at high risk for cutaneous SCC.

  1. Inhibition of akt enhances the chemopreventive effects of topical rapamycin in mouse skin

    Science.gov (United States)

    Dickinson, Sally E; Janda, Jaroslav; Criswell, Jane; Blohm-Mangone, Karen; Olson, Erik R.; Liu, Zhonglin; Barber, Christie; Rusche, Jadrian J.; Petricoin, Emmanuel; Calvert, Valerie; Einspahr, Janine G.; Dickinson, Jesse; Stratton, Steven P.; Curiel-Lewandrowski, Clara; Saboda, Kathylynn; Hu, Chengcheng; Bode, Ann M.; Dong, Zigang; Alberts, David S.; Bowden, G. Timothy

    2016-01-01

    The PI3Kinase/Akt/mTOR pathway has important roles in cancer development for multiple tumor types, including UV-induced non-melanoma skin cancer. Immunosuppressed populations are at increased risk of aggressive cutaneous squamous cell carcinoma (SCC). Individuals who are treated with rapamycin, (sirolimus, a classical mTOR inhibitor) have significantly decreased rates of developing new cutaneous SCCs compared to those that receive traditional immunosuppression. However, systemic rapamycin use can lead to significant adverse events. Here we explored the use of topical rapamycin as a chemopreventive agent in the context of solar simulated light (SSL)-induced skin carcinogenesis. In SKH-1 mice, topical rapamycin treatment decreased tumor yields when applied after completion of 15 weeks of SSL exposure compared to controls. However, applying rapamycin during SSL exposure for 15 weeks, and continuing for 10 weeks after UV treatment, increased tumor yields. We also examined whether a combinatorial approach might result in more significant tumor suppression by rapamycin. We validated that rapamycin causes increased Akt (S473) phosphorylation in the epidermis after SSL, and show for the first time that this dysregulation can be inhibited in vivo by a selective PDK1/Akt inhibitor, PHT-427. Combining rapamycin with PHT-427 on tumor prone skin additively caused a significant reduction of tumor multiplicity compared to vehicle controls. Our findings indicate that patients taking rapamycin should avoid sun exposure, and that combining topical mTOR inhibitors and Akt inhibitors may be a viable chemoprevention option for individuals at high risk for cutaneous SCC.

  2. Signal transduction pathways regulating cyclooxygenase-2 expression: potential molecular targets for chemoprevention.

    Science.gov (United States)

    Chun, Kyung-Soo; Surh, Young-Joon

    2004-09-15

    Expression of cyclooxygenase-2 (COX-2) has been reported to be elevated in human colorectal adenocarcinoma and other tumors, including those of breast, cervical, prostate, and lung. Genetic knock-out or pharmacological inhibition of COX-2 has been shown to protect against experimentally-induced carcinogenesis. Results from epidemiological and laboratory studies indicate that regular intake of selective COX-2 inhibitors reduces the risk of several forms of human malignancies. Thus, it is conceivable that targeted inhibition of abnormally or improperly elevated COX-2 provides one of the most effective and promising strategies for cancer chemoprevention. The COX-2 promoter contains a TATA box and binding sites for several transcription factors including nuclear factor-kappaB (NF-kappaB), nuclear factor for interleukin-6/CCAAT enhancer-binding protein (NF-IL6/C/EBP) and cyclic AMP response element (CRE) binding protein. Upregulation of COX-2 is mediated by a variety of stimuli including tumor promoters, oncogenes, and growth factors. Stimulation of either protein kinase C (PKC) or Ras signaling enhances mitogen-activated protein kinase (MAPK) activity, which, in turn, activates transcription of cox-2. Celecoxib, the first US FDA approved selective COX-2 inhibitor, initially developed for the treatment of adult rheumatoid arthritis and osteoarthritis, has been reported to reduce the formation of polyps in patients with familial adenomatous polyposis. This COX-2 specific inhibitor also protects against experimentally-induced carcinogenesis, but the underlying molecular mechanisms are poorly understood. The present review covers the signal transduction pathways responsible for regulating COX-2 expression as novel molecular targets of chemopreventive agents with celecoxib as a specific example.

  3. The Chemopreventive Effect of Tamoxifen Combined with Celecoxib on DMBA chemically-Induced Breast Cancer

    Institute of Scientific and Technical Information of China (English)

    Xiaoxu Liu; Huafeng Kang; Xijing Wang; Zhijun Dai; Fengjie Xue; Xinghuan Xue

    2007-01-01

    Objective: To investigate the chemopreventive effect of tamoxifen combined with a COX-2 selective inhibitor, celecoxib, on breast cancer in rats chemically induced by 7,12-dimethylben (a)anthracene (DMBA). Methods:DMBA was irrigated into the stomaches of SD female rats to build breast cancer model. A total of 120 rats were divided into four groups: control group, tamoxifen group, celecoxib group and combined group. The incidence rate, latent period, number and volume of breast cancer were detected and analyzed. Results:The tumor incidence rate of tamoxifen group (48.15%, 13/27) and celecoxib group (50.00%,14/28) were lower than that of control group (85.71%, 24/28), but higher than that of combined group (21.43%, 6/28). The tumor's latent period of tamoxifen group (97.54±1.85 d) and celecoxib group (96.79±2.89 d) were longer than that of control group (89.50±5.99 d), but shorter than that of combined group (103.67±3.39 d). The average tumor number of tamoxifen group (1.77±0.73) and celecoxib group (1.71±0.61) were less than that of control group (3.50±1.62), but more than that of combined group ( 1.17±0.42 ). The average tumor volume of tamoxifen group (1.78±0.71 cm3) and celecoxib group (2.05±1.04 cm3) were smaller than that of control group (6.42±3.96 cm3), but bigger than that of combined group (0.71±0.96 cm3) (P < 0.05 respectively).Conclusion:Celecoxib and tamoxifen are effective drugs in preventing the occurrence of rat breast cancer chemically induced by DMBA. Furthermore, combination of them has better chemopreventive effect.

  4. Resveratrol enhances the chemopreventive effect of celecoxib in chemically induced breast cancer in rats.

    Science.gov (United States)

    Kisková, Terézia; Jendželovský, Rastislav; Rentsen, Erdenetsetsek; Maier-Salamon, Alexandra; Kokošová, Natália; Papčová, Zuzana; Mikeš, Jaromír; Orendáš, Peter; Bojková, Bianka; Kubatka, Peter; Svoboda, Martin; Kajo, Karol; Fedoročko, Peter; Jäger, Walter; Ekmekcioglu, Cem; Kassayová, Monika; Thalhammer, Theresia

    2014-11-01

    Resveratrol and celecoxib were used as chemopreventive agents in animal models of carcinogenesis, and exert antiproliferative and proapoptotic effects on cancer cells. Therefore, the aim of this study was to evaluate whether combining resveratrol with celecoxib may exert more potent anticarcinogenic effects than the single agents. Mammary carcinogenesis was initiated in 70 female Sprague-Dawley rats with N-methyl-N-nitrosourea (NMU). The chemoprevention with resveratrol, celecoxib, and their combination started 2 weeks before the first carcinogen dose and lasted until the end of the experiment. Tumor incidence and frequency, latency period, tumor volume, the expression of cyclooxygenase 2 (COX2) and growth differentiation factor 15 (GDF15), and also the formation of reactive oxygen species were analyzed using different methods. In addition, the levels of resveratrol and its metabolites in blood and selected tumor tissues were determined by high-performance liquid chromatography. Finally, the anticancer effects of the reagents were studied in the human breast cancer cell line MCF-7. Celecoxib as a single agent significantly decreased tumor frequency, prolonged tumor latency, and decreased the total number of malignant tumors compared with the NMU conditions. Tumor volume was nonsignificantly reduced (0.68±0.25 vs. 0.93±0.28 cm3). Importantly, the addition of resveratrol to celecoxib reduced tumor volume by 60% compared with celecoxib alone (from 0.68±0.25 to 0.27±0.07 cm3, Pcancer-preventive effects of this application. This study showed that in NMU-induced mammary cancer in rats, the combination of resveratrol and celecoxib led to a significant reduction in all tumor parameters. In addition, in terms of tumor volume, the combination was more efficient than celecoxib as a single agent.

  5. Cancer chemoprevention by phytochemicals: potential molecular targets,biomarkers and animal models

    Institute of Scientific and Technical Information of China (English)

    Ki Han KWON; Avantika BARVE; Siwang YU; Mou-Tuan HUANG; Ah-Ng Tony KONG

    2007-01-01

    Recent studies have strongly indicated that certain daily-consumed dietary phytochemicals could have cancer protective effects against transgenic mice can-cer models and cancers mediated by carcinogens, irradiations and carcinogenic metabolites derived from exogenous or endogenous sources. The cancer-protec-tive effects elicited by these dietary compounds are believed to be due at least in part to the induction of cellular defense systems including the detoxifying and antioxidant enzymes system, as well as the inhibition of anti-inflammatory and anti-cell growth signaling pathways culminating in cell cycle arrest and/or cell-death. In this review, we summarize the potential mechanisms including the modu-lation of nuclear factor kappaB (NF-κB), cyclooxygenases-2 (COX-2), activator protein-1 (AP-1), mitogen-activated protein kinases (MAPKs) and the induction of phase Ⅱ cellular detoxifying and antioxidant enzymes mediated mainly by the antioxidant response elements (ARE) within the promoter regions of these genes through nuclear factor-erythroid 2-related factor 2 (Nrf2), a member of the Cap 'n' collar (CNC) family of the basic region-leucine zipper transcription factor. In addition, we also review several animal models of carcinogenesis and cancer chemopreventive efficacy studies of these animal models using dietary chemopreventive compounds. Finally, we discuss the cellular signaling cascades mediated by Nrf2, NF-κB, AP-1, MAPKs and COX-2, which have been considered to play pivotal roles in tumor initiation, promotion and progression processes,and could be promising molecular targets for the design of drugs targeting cancer prevention and therapy.

  6. Chemoprevention gene therapy (CGT): novel combinatorial approach for preventing and treating pancreatic cancer.

    Science.gov (United States)

    Sarkar, S; Azab, B M; Das, S K; Quinn, B A; Shen, X; Dash, R; Emdad, L; Thomas, S; Dasgupta, S; Su, Z-Z; Wang, X-Y; Sarkar, D; Fisher, P B

    2013-08-01

    Pancreatic cancer remains one of the deadliest of all cancers despite aggressive surgical treatment combined with adjuvant radiotherapy and chemotherapy. Chemoresistance and radioresistance are the principal causes of failure of pancreatic cancer patients to respond to therapy. Conditionally replication competent adenovirus (CRCA)-based cancer gene therapy is an innovative strategy for treating cancers displaying inherent resistance to treatment. Limitations of current adenovirus (Ad)-based gene therapies for malignant tumors include lack of cancer-specificity, and effective and targeted delivery. To remedy this situation, CRCAs have been designed that express E1A, necessary for Ad replication, under the control of a cancer-specific progression elevated gene-3 promoter (PEG-Prom) with concomitant expression of an immunomodulatory cytokine, such as mda-7/IL-24 or interferon-γ (IFN-γ), under the control of a ubiquitous and strong cytomegalovirus promoter (CMV-Prom) from the E3 region. These bipartite CRCAs, when armed with a transgene, are called cancer terminator viruses (CTVs), i.e., Ad.PEG-E1A-CMV-mda-7 (CTV-M7) and Ad.PEG-E1A-CMV-IFN-γ (CTV-γ), because of their universal effectiveness in cancer treatment irrespective of p53/pRb/p16 or other genetic alterations in tumor cells. In addition to their selective oncolytic effects in tumor cells, the potent 'bystander antitumor' properties of MDA-7/IL-24 and IFN-γ embody the CTVs with expanded treatment properties for both primary and distant cancers. Pancreatic cancer cells display a "translational block" of mda-7/IL-24 mRNA, limiting production of MDA-7/IL-24 protein and cancer-specific apoptosis. Specific chemopreventive agents abrogate this "translational block" resulting in pancreatic cancer-specific killing. This novel chemoprevention gene therapy (CGT) strategy holds promise for both prevention and treatment of pancreatic cancers where all other strategies have proven ineffective.

  7. A systems pharmacokinetic and pharmacodynamic approach to identify opportunities and pitfalls in energy stress-mediated chemoprevention: the use of metformin and other biguanides.

    Science.gov (United States)

    Thompson, Matthew D; Thompson, Henry J

    2012-12-01

    Metformin, a widely used anti-hyperglycemic drug in the biguanide class, is currently under investigation for the prevention of cancer. Surprisingly however, considering the time and cost of clinical chemoprevention trials and the current scrutiny of cancer chemoprevention, limited attention has been given to integrating available data, identifying the subpopulations most likely to benefit, or to quantitatively understanding the potential pitfalls of biguanide chemoprevention. Herein, a physiologically-based pharmacokinetic (PBPK) and pharmacodynamic framework is proposed for integrating information on physicochemical, cell-based, animal, and human studies of various biguanides to identify gaps in knowledge and to build a systems model that may facilitate the planning of randomized cancer chemoprevention trials of metformin.

  8. DNA repair protocols

    DEFF Research Database (Denmark)

    Bjergbæk, Lotte

    In its 3rd edition, this Methods in Molecular Biology(TM) book covers the eukaryotic response to genomic insult including advanced protocols and standard techniques in the field of DNA repair. Offers expert guidance for DNA repair, recombination, and replication. Current knowledge of the mechanisms...... that regulate DNA repair has grown significantly over the past years with technology advances such as RNA interference, advanced proteomics and microscopy as well as high throughput screens. The third edition of DNA Repair Protocols covers various aspects of the eukaryotic response to genomic insult including...... recent advanced protocols as well as standard techniques used in the field of DNA repair. Both mammalian and non-mammalian model organisms are covered in the book, and many of the techniques can be applied with only minor modifications to other systems than the one described. Written in the highly...

  9. Blind Cognitive MAC Protocols

    CERN Document Server

    Mehanna, Omar; Gamal, Hesham El

    2008-01-01

    We consider the design of cognitive Medium Access Control (MAC) protocols enabling an unlicensed (secondary) transmitter-receiver pair to communicate over the idle periods of a set of licensed channels, i.e., the primary network. The objective is to maximize data throughput while maintaining the synchronization between secondary users and avoiding interference with licensed (primary) users. No statistical information about the primary traffic is assumed to be available a-priori to the secondary user. We investigate two distinct sensing scenarios. In the first, the secondary transmitter is capable of sensing all the primary channels, whereas it senses one channel only in the second scenario. In both cases, we propose MAC protocols that efficiently learn the statistics of the primary traffic online. Our simulation results demonstrate that the proposed blind protocols asymptotically achieve the throughput obtained when prior knowledge of primary traffic statistics is available.

  10. Cytoskeleton - Methods and Protocols

    Directory of Open Access Journals (Sweden)

    CarloAlberto Redi

    2010-03-01

    Full Text Available Cytoskeleton - Methods and ProtocolsSecond edition, 2010; Ray H. Gavin (Ed; Springer Protocols methods in molecular biology, vol. 586 Humana press, Totowa, New Jersey (USA; Pages: 390; €95.44; ISBN: 978-1-60761-375-6Ray H. Gavin, from the Brooklyn College of The City University of New York, Brooklyn, NY, USA, wrote a few line as preface of this book. This is quite understandable: there is not a great need of words when there are facts that sustain and favour the dissemination of a cultural product. This is the case of the second edition of Cytoskeleton - Methods and Protocols, which appears just ten years after the first edition...

  11. Trianthema portulacastrum Linn. exerts chemoprevention of 7,12-dimethylbenz(a)anthracene-induced mammary tumorigenesis in rats

    Energy Technology Data Exchange (ETDEWEB)

    Bishayee, Anupam, E-mail: abishayee@auhs.edu [Department of Pharmaceutical Sciences, School of Pharmacy, American University of Health Sciences, Signal Hill, CA 90755 (United States); Mandal, Animesh [Cancer Therapeutics and Chemoprevention Group, Department of Pharmaceutical Sciences, College of Pharmacy, Northeast Ohio Medical University, Rootstown, OH 44272 (United States)

    2014-10-15

    Highlights: • Dietary administration of an ethanolic extract of aerial parts of T. portulacastrum (TPE) exhibits a striking chemopreventive effect in an experimentally induced classical animal model of breast cancer. • The mammary tumor-inhibitory effect of TPE could be achieved, at least in part, though intervention of key hallmark capabilities of tumor cells, such as abnormal cell proliferation and evasion of apoptosis. • TPE is capable of diminishing activated canonical Wnt/β-catenin signaling to exhibit antiproliferative, proapoptotic and oncostatic effects during this early-stage mammary carcinoma. • These results coupled with a safety profile of T. portulacastrum may encourage further studies to understand the full potential of this dietary plant for chemoprevention of breast cancer. - Abstract: Due to limited treatment options for advanced-stage metastatic breast cancer, a high priority should be given to develop non-toxic chemopreventive drugs. The value of various natural and dietary agents to reduce the risk of developing breast cancer is well established. Trianthema portulacastrum Linn. (Aizoaceae), a dietary and medicinal plant, has been found to exert antihepatotoxic and antihepatocarcinogenic properties in rodents. This study was initiated to investigate mechanism-based chemopreventive potential of an ethanolic extract of T. portulacastrum (TPE) against 7,12-dimethylbenz(a)anthracene (DMBA)-initiated rat mammary gland carcinogenesis, an experimental tumor model that closely resembles human breast cancer. Rats had access to a basal diet supplemented with TPE to yield three dietary doses of the extract, i.e., 50, 100 and 200 mg/kg body weight. Following two weeks of TPE treatment, mammary tumorigenesis was initiated by oral administration of DMBA (50 mg/kg body weight). At the end of the study (16 weeks after DMBA exposure), TPE exhibited a striking reduction of DMBA-induced mammary tumor incidence, total tumor burden and average tumor weight

  12. Demarcation of Security in Authentication Protocols

    DEFF Research Database (Denmark)

    Ahmed, Naveed; Jensen, Christian D.

    2011-01-01

    Security analysis of communication protocols is a slippery business; many “secure” protocols later turn out to be insecure. Among many, two complains are more frequent: inadequate definition of security and unstated assumptions in the security model. In our experience, one principal cause...... for such state of affairs is an apparent overlap of security and correctness, which may lead to many sloppy security definitions and security models. Although there is no inherent need to separate security and correctness requirements, practically, such separation is significant. It makes security analysis...... easier, and enables us to define security goals with a fine granularity. We present one such separation, by introducing the notion of binding sequence as a security primitive. A binding sequence, roughly speaking, is the only required security property of an authentication protocol. All other...

  13. Use of YouScope to implement systematic microscopy protocols.

    Science.gov (United States)

    Lang, Moritz; Rudolf, Fabian; Stelling, Jörg

    2012-04-01

    Complex microscopy protocols, e.g., to dynamically track multiple signals in living cells under different conditions, are becoming more common. However, the implementation of complex protocols on modern, motorized microscopes often requires their reformulation into low-level machine language. This recoding is a time-consuming and error-prone task that often requires advanced programming skills. This unit describes how to use the high level, open-source microscope control platform YouScope to implement complex measurement protocols. Three protocols detail how to install and configure YouScope on a motorized microscope, how to use YouScope to quickly assess the quality of a sample, and how to set up imaging protocols for cells in a microplate. In addition to these protocols, descriptions are given for the use of various other tools YouScope provides to successfully accomplish various microscopy tasks.

  14. Apoptosis - Methods and Protocols

    Directory of Open Access Journals (Sweden)

    CarloAlberto Redi

    2010-03-01

    Full Text Available Apoptosis - Methods and ProtocolsSecond edition, 2009; Peter Erhardt and Ambrus Toth (Eds; Springer Protocols - Methods in molecular biology, vol. 559; Humana press, Totowa, New Jersey (USA; Pages: 400; €88.35; ISBN: 978-1-60327-016-8The editors rightly begin the preface telling us that: “The ability to detect and quantify apoptosis, to understand its biochemistry and to identify its regulatory genes and proteins is crucial to biomedical research”. Nowadays this is a grounding concept of biology and medicine. What is particularly remarkable...

  15. A security analysis of the 802.11s wireless mesh network routing protocol and its secure routing protocols.

    Science.gov (United States)

    Tan, Whye Kit; Lee, Sang-Gon; Lam, Jun Huy; Yoo, Seong-Moo

    2013-09-02

    Wireless mesh networks (WMNs) can act as a scalable backbone by connecting separate sensor networks and even by connecting WMNs to a wired network. The Hybrid Wireless Mesh Protocol (HWMP) is the default routing protocol for the 802.11s WMN. The routing protocol is one of the most important parts of the network, and it requires protection, especially in the wireless environment. The existing security protocols, such as the Broadcast Integrity Protocol (BIP), Counter with cipher block chaining message authentication code protocol (CCMP), Secure Hybrid Wireless Mesh Protocol (SHWMP), Identity Based Cryptography HWMP (IBC-HWMP), Elliptic Curve Digital Signature Algorithm HWMP (ECDSA-HWMP), and Watchdog-HWMP aim to protect the HWMP frames. In this paper, we have analyzed the vulnerabilities of the HWMP and developed security requirements to protect these identified vulnerabilities. We applied the security requirements to analyze the existing secure schemes for HWMP. The results of our analysis indicate that none of these protocols is able to satisfy all of the security requirements. We also present a quantitative complexity comparison among the protocols and an example of a security scheme for HWMP to demonstrate how the result of our research can be utilized. Our research results thus provide a tool for designing secure schemes for the HWMP.

  16. Algebra model and security analysis for cryptographic protocols

    Institute of Scientific and Technical Information of China (English)

    HUAI Jinpeng; LI Xianxian

    2004-01-01

    More and more cryptographic protocols have been used to achieve various security requirements of distributed systems in the open network environment. However cryptographic protocols are very difficult to design and analyze due to the complexity of the cryptographic protocol execution, and a large number of problems are unsolved that range from the theory framework to the concrete analysis technique. In this paper, we build a new algebra called cryptographic protocol algebra (CPA) for describing the message operations with many cryptographic primitives, and proposed a new algebra model for cryptographic protocols based on the CPA. In the model, expanding processes of the participant's knowledge on the protocol runs are characterized with some algebraic notions such as subalgebra, free generator and polynomial algebra, and attack processes are modeled with a new notion similar to that of the exact sequence used in homological algebra. Then we develope a mathematical approach to the cryptographic protocol security analysis. By using algebraic techniques, we have shown that for those cryptographic protocols with some symmetric properties, the execution space generated by an arbitrary number of participants may boil down to a smaller space generated by several honest participants and attackers. Furthermore we discuss the composability problem of cryptographic protocols and give a sufficient condition under which the protocol composed of two correct cryptographic protocols is still correct, and we finally offer a counterexample to show that the statement may not be true when the condition is not met.

  17. An improved arbitrated quantum signature protocol based on the key-controlled chained CNOT encryption

    Science.gov (United States)

    Zhang, Long; Sun, Hong-Wei; Zhang, Ke-Jia; Jia, Heng-Yue

    2017-03-01

    In this paper, a new quantum encryption based on the key-controlled chained CNOT operations, which is named KCCC encryption, is proposed. With the KCCC encryption, an improved arbitrated quantum signature (AQS) protocol is presented. Compared with the existing protocols, our protocol can effectively prevent forgery attacks and disavowal attacks. Moreover, only single state is required in the protocol. We hope it is helpful to further research in the design of AQS protocols in future.

  18. Protocol Materials: A Clarification.

    Science.gov (United States)

    Innerd, Wilfred; O'Gorman, David

    "Protocol materials" are records or recordings of a wide variety of behavioral situations. Characteristically they are neither simulated nor extensively edited. They are to be used for the empirical verification of concepts derived from both educational theory and the social sciences. They are attempts to capture reality so that it may be studied…

  19. THE MASTER PROTOCOL CONCEPT

    Science.gov (United States)

    Allegra, Carmen J.

    2015-01-01

    During the past decade, biomedical technologies have undergone an explosive evolution---from the publication of the first complete human genome in 2003, after more than a decade of effort and at a cost of hundreds of millions of dollars---to the present time, where a complete genomic sequence can be available in less than a day and at a small fraction of the cost of the original sequence. The widespread availability of next generation genomic sequencing has opened the door to the development of precision oncology. The need to test multiple new targeted agents both alone and in combination with other targeted therapies, as well as classic cytotoxic agents, demand the development of novel therapeutic platforms (particularly Master Protocols) capable of efficiently and effectively testing multiple targeted agents or targeted therapeutic strategies in relatively small patient subpopulations. Here, we describe the Master Protocol concept, with a focus on the expected gains and complexities of the use of this design. An overview of Master Protocols currently active or in development is provided along with a more extensive discussion of the Lung Master Protocol (Lung-MAP study). PMID:26433553

  20. Principles of Protocol Design

    DEFF Research Database (Denmark)

    Sharp, Robin

    This is a new and updated edition of a book first published in 1994. The book introduces the reader to the principles used in the construction of a large range of modern data communication protocols, as used in distributed computer systems of all kinds. The approach taken is rather a formal one...

  1. Security Protocol Design: A Case Study Using Key Distribution Protocols

    Directory of Open Access Journals (Sweden)

    Reiner Dojen

    2009-10-01

    Full Text Available Nowadays security protocols are a key component in providing security services for fixed and mobile networks. These services include data confidentiality, radio link encryption, message integrity, mobile subscriber authentication, electronic payment, certified e-mail, contract signing and nonrepudiation. This paper is concerned with design of effective security protocols. Security protocols are introduced and some common attacks against security protocols are discussed. The vulnerabilities that lead to theattacks are analyzed and guidelines for effective security protocol design are proposed. The presented guidelines are applied to the Andrew Secure RPC protocol and its adapted versions. It is demonstrated that compliance with the guidelines successfully avoidsfreshness and parallel session attacks.

  2. In vivo phase II-enzymes inducers, as potential chemopreventive agents, based on the chalcone and furoxan skeletons.

    Science.gov (United States)

    Cabrera, Mauricio; Mastandrea, Ignacio; Otero, Gabriel; Cerecetto, Hugo; González, Mercedes

    2016-04-15

    Cancer chemoprevention involves prevention/delay/reverse of the carcinogenic process through administration of cancer chemopreventive agents (CCA). Compounds which are able to induce detoxification-enzymes, especially monofunctional phase II enzymes, have become in excellent approaches for new CCA. Herein, we report the synthesis of new furoxanyl chalcone-like hybrid compounds as CCA. In vitro studies showed that phenylfuroxanyl derivatives 6 and 9 displayed the best activities being 9 the greatest monofunctional-inducer. Additionally, compounds were non-mutagenic against TA98 Salmonella typhimurium strain (Ames test) and could be used in the prevention of the progression of pre-malignant lesions for their cytotoxic activity against tumoral cells. In vivo proof of concept showed increment on phase II-enzymes activities in liver, colon and mammary gland having derivative 9 the best induction profiles. We probed Nrf2 nuclear translocation is operative for both compounds allowing to exert protective effects via expression of downstream phase-II enzymes.

  3. Multiparty Authentication Services and Key Agreement Protocols with Semi-Trusted Third Party

    Institute of Scientific and Technical Information of China (English)

    郑东; 陈克非; 尤晋元

    2002-01-01

    This paper introduces a new family of group key establishment protocols suit-able for small or medium-sized groups. Five protocols are presented, using a semi-trustedserver, with varying security service. The first one is a non-authenticated key agreement pro-tocol suitable for applications with low security requirements. The second protocol adds anauthenticated key agreement to provide collaborative authentication. The third and the fourthprotocols provide key establishment with integrity and confirmation services, and the fifth pro-tocol is the member adding protocol. A major advantage of the protocols is that they reducethe numbers of rounds from n to 5.

  4. A Chemoprevention Trial to Study the Effects of High Tea Consumption on Smoking-Related Oxidative Stress

    Science.gov (United States)

    2007-02-01

    each subject’s baseline history of smoking, diet and tea intake, plasma catechins , and levels biomarkers of oxidative stress at baseline. All...Effects of High Tea Consumption on Smoking-Related Oxidative Stress PRINCIPAL INVESTIGATOR: Iman A. Hakim, MD, Ph., MPH...3. DATES COVERED (From - To) 13 Jul 06 – 12 Jan 07 4. TITLE AND SUBTITLE A Chemoprevention Trial to Study the Effects of High Tea Consumption on 5a

  5. New Enlightenment of Skin Cancer Chemoprevention through Phytochemicals: In Vitro and In Vivo Studies and the Underlying Mechanisms

    OpenAIRE

    2014-01-01

    Skin cancer is still a major cause of morbidity and mortality worldwide. Skin overexposure to ultraviolet irradiations, chemicals, and several viruses has a capability to cause severe skin-related disorders including immunosuppression and skin cancer. These factors act in sequence at various steps of skin carcinogenesis via initiation, promotion, and/or progression. These days cancer chemoprevention is recognized as the most hopeful and novel approach to prevent, inhibit, or reverse the proce...

  6. Efficacy of geraniol but not of β-ionone or their combination for the chemoprevention of rat colon carcinogenesis

    Directory of Open Access Journals (Sweden)

    A. Vieira

    2011-06-01

    Full Text Available β-ionone (βI, a cyclic isoprenoid, and geraniol (GO, an acyclic monoterpene, represent a promising class of dietary chemopreventive agents against cancer, whose combination could result in synergistic anticarcinogenic effects. The chemopreventive activities of βI and GO were evaluated individually or in combination during colon carcinogenesis induced by dimethylhydrazine in 48 3-week-old male Wistar rats (12 per group weighing 40-50 g. Animals were treated for 9 consecutive weeks with βI (16 mg/100 g body weight, GO (25 mg/100 g body weight, βI combined with GO or corn oil (control. Number of total aberrant crypt foci (ACF and of ACF ≥4 crypts in the distal colon was significantly lower in the GO group (66 ± 13 and 9 ± 2, respectively compared to control (102 ± 9 and 17 ± 3 and without differences in the βI (91 ± 11 and 14 ± 3 and βI+GO groups (96 ± 5 and 19 ± 2. Apoptosis level, identified by classical apoptosis morphological criteria, in the distal colon was significantly higher in the GO group (1.64 ± 0.06 apoptotic cells/mm² compared to control (0.91 ± 0.07 apoptotic cells/mm². The GO group presented a 0.7-fold reduction in Bcl-2 protein expression (Western blot compared to control. Colonic mucosa concentrations of βI and GO (gas chromatography/mass spectrometry were higher in the βI and GO groups, respectively, compared to the control and βI+GO groups. Therefore, GO, but not βI, represents a potential chemopreventive agent in colon carcinogenesis. Surprisingly, the combination of isoprenoids does not represent an efficient chemopreventive strategy.

  7. Trianthema portulacastrum Linn. exerts chemoprevention of 7,12-dimethylbenz(a)anthracene-induced mammary tumorigenesis in rats.

    Science.gov (United States)

    Bishayee, Anupam; Mandal, Animesh

    2014-10-01

    Due to limited treatment options for advanced-stage metastatic breast cancer, a high priority should be given to develop non-toxic chemopreventive drugs. The value of various natural and dietary agents to reduce the risk of developing breast cancer is well established. Trianthema portulacastrum Linn. (Aizoaceae), a dietary and medicinal plant, has been found to exert antihepatotoxic and antihepatocarcinogenic properties in rodents. This study was initiated to investigate mechanism-based chemopreventive potential of an ethanolic extract of T. portulacastrum (TPE) against 7,12-dimethylbenz(a)anthracene (DMBA)-initiated rat mammary gland carcinogenesis, an experimental tumor model that closely resembles human breast cancer. Rats had access to a basal diet supplemented with TPE to yield three dietary doses of the extract, i.e., 50, 100 and 200 mg/kg body weight. Following two weeks of TPE treatment, mammary tumorigenesis was initiated by oral administration of DMBA (50 mg/kg body weight). At the end of the study (16 weeks after DMBA exposure), TPE exhibited a striking reduction of DMBA-induced mammary tumor incidence, total tumor burden and average tumor weight and reversed intratumor histopathological alterations. TPE dose-dependently suppressed proliferating cell nuclear antigen and cyclin D1 expression, induced apoptosis, upregulated proapoptotic protein Bax, downregulated antiapoptotic protein Bcl-2 and diminished the expression of nuclear and cytosolic β-catenin in mammary tumors. Our results clearly provide the first experimental evidence that TPE exerts chemopreventive effect in the classical DMBA model of breast cancer by suppressing abnormal cell proliferation and inducing apoptosis mediated through alteration of Bax/Bcl-2 ratio. Mechanistically, TPE is capable of diminishing activated canonical Wnt/β-catenin signaling to exhibit antiproliferative, proapoptotic and oncostatic effects during an early-stage breast cancer. These results may encourage further

  8. Topical polyethylene glycol as a novel chemopreventive agent for oral cancer via targeting of epidermal growth factor response.

    Directory of Open Access Journals (Sweden)

    Ramesh K Wali

    Full Text Available Head and neck squamous cell carcinoma (HNSCC is a major cause of morbidity and mortality underscoring the need for safe and effective chemopreventive strategies. Targeting epidermal growth factor receptor (EGFR is attractive in that it is an early critical event in HNSCC pathogenesis. However, current agents lack efficacy or have unacceptable toxicity. Several groups have demonstrated that the over-the-counter medication, polyethylene glycol (PEG has remarkable chemopreventive efficacy against colon carcinogenesis. Importantly, we reported that this effect is mediated through EGFR internalization/degradation. In the current study, we investigated the chemopreventive efficacy of this agent against HNSCC, using both the well validated animal model 4-NQO (4-nitroquinoline 1-oxide rat model and cell culture with the human HNSCC cell line SCC-25. We demonstrated that daily topical application of 10% PEG-8000 in the oral cavity (tongue and cavity wall post 4NQO initiation resulted in a significant reduction in tumor burden (both, tumor size and tumors/tumor bearing rat without any evidence of toxicity. Immunohistochemical studies depicted decreased proliferation (number of Ki67-positive cells and reduced expression of EGFR and its downstream effectors cyclin D1 in the tongue mucosa of 4NQO-rats treated with PEG. We showed that EGFR was also markedly downregulated in SCC-25 cells by PEG-8000 with a concomitant induction of G1-S phase cell-cycle arrest, which was potentially mediated through upregulated p21(cip1/waf1. In conclusion, we demonstrate, for the first time, that PEG has promising efficacy and safety as a chemopreventive efficacy against oral carcinogenesis.

  9. Chemoprevention of HBV-related hepatocellular carcinoma by the combined product of resveratrol and silymarin in transgenic mice

    OpenAIRE

    2013-01-01

    ABSTRACTBackground: Patients with chronic hepatitis B virus (HBV) infection are at a high risk to develop hepatocellular carcinoma (HCC). Recently, metabolic syndrome has been found to carry a risk for HCC development. Considering the limitation of chemotherapeutic drugs for HCCs, the development of chemopreventive agents for high risk chronic HBV carriers is urgently demanded. In this study, we used combined silymarin and resveratrol extract which have been shown to exhibit biologic effects ...

  10. Mixtures of Uncaria and Tabebuia extracts are potentially chemopreventive in CBA/Ca mice: a long-term experiment.

    Science.gov (United States)

    Budán, Ferenc; Szabó, István; Varjas, Tímea; Nowrasteh, Ghodratollah; Dávid, Tamás; Gergely, Péter; Varga, Zsuzsa; Molnár, Kornélia; Kádár, Balázs; Orsós, Zsuzsa; Kiss, István; Ember, István

    2011-04-01

    A long-term experimental animal model was developed by our research group for the evaluation of potential chemopreventive effects. The inhibitory effects of agents on carcinogen (7,12-dimethylbenz[a]anthracene (DMBA) induced molecular epidemiological biomarkers, in this case the expression of key onco/suppressor genes were investigated. The expression pattern of c-myc, Ha-ras, Bcl-2, K-ras protooncogene and p53 tumour suppressor gene were studied to elucidate early carcinogenic and potential chemopreventive effects. The consumption of so-called Claw of Dragon tea (CoD™ tea) containing the bark of Uncaria guianensis, Cat's Claw (Uncaria sp. U. tomentosa) and Palmer trumpet-tree (Tabebuia sp. T. avellanedae) was able to decrease the DMBA-induced onco/suppressor gene overexpression in a short-term animal experiment. In a following study CBA/Ca mice were treated with 20 mg/kg bw DMBA intraperitoneally (i.p.) and the expression patterns of onco/suppressor genes were examined at several time intervals. According to the examined gene expression patterns in this long-term experiment the chemopreventive effect of CoD™ tea consumption could be confirmed.

  11. Azathioprine, mucosal healing in ulcerative colitis, and the chemoprevention of colitic cancer: a clinical-practice-based forecast.

    Science.gov (United States)

    Actis, Giovanni C; Pellicano, Rinaldo; David, Ezio; Sapino, Anna

    2010-03-01

    The development of colorectal cancer in ulcerative colitis is a function of disease duration, with the risk approaching 14% at 25 years. Colitic cancer has become an issue in the last decades, as the availability of effective immune suppressors has reduced resort to curative colectomies. Scrutiny of the available drug options for ulcerative colitis has generated solid evidence of a chemopreventive role of mesalamines. Recent studies on the thiopurines azathioprine and mercaptopurine have unraveled the ability of these drugs to reduce inflammation and influence adaptive immunity by enhancing apoptosis. This evidence, speaking in favor of a chemopreventive role of thiopurines, has not been supported until recently by clinical studies. By contrast, endoscopic and clinical data in our hands have continued to suggest such a role: of a cohort of ulcerative colitis patients treated with azathioprine for 17 years, those on active treatment had no mucosal inflammation on endoscopy and overall none in this cohort developed cancer. This retrospective data have now been validated by cutting-edge information from a prospective nationwide study from an independent group which found a significant chemopreventive effect of azathioprine in those with extended long-standing colitis. Combination of our single-center experience with the data from this large study strongly indicates that the immune modulatory properties of thiopurines can translate into clinically meaningful anti-cancer activity in colitis. These results are likely to influence the medical choices of inflammatory bowel disease caregivers in the decades to come.

  12. Acyclic retinoid in chemoprevention of hepatocellular carcinoma: Targeting phosphorylated retinoid X receptor-α for prevention of liver carcinogenesis

    Directory of Open Access Journals (Sweden)

    Masahito Shimizu

    2012-01-01

    Full Text Available One of the key features of hepatocellular carcinoma (HCC is the high rate of intrahepatic recurrence that correlates with poor prognosis. Therefore, in order to improve the clinical outcome for patients with HCC, development of a chemopreventive agent that can decrease or delay the incidence of recurrence is a critical issue for urgent investigation. Acyclic retinoid (ACR, a synthetic retinoid, successfully improves HCC patient survival by preventing recurrence and the formation of secondary tumors. A malfunction of the retinoid X receptor-α (RXRα due to phosphorylation by the Ras-MAPK signaling pathway plays a critical role in liver carcinogenesis, and ACR exerts chemopreventive effects on HCC development by inhibiting RXRα phosphorylation. Here, we review the relationship between retinoid signaling abnormalities and liver disease, the mechanisms of how RXRα phosphorylation contributes to liver carcinogenesis, and the detailed effects of ACR on preventing HCC development, especially based on the results of our basic and clinical research. We also outline the concept of "clonal deletion and inhibition" therapy, which is defined as the removal and inhibition of latent malignant clones from the liver before they expand into clinically detectable HCC, because ACR prevents the development of HCC by implementing this concept. Looking toward the future, we discuss "combination chemoprevention" using ACR as a key drug since it can generate a synergistic effect, and may thus be an effective new strategy for the prevention of HCC.

  13. The current role of neoadjuvant/adjuvant/chemoprevention therapy in partial hepatectomy for hepatocellular carcinoma:a systematic review

    Institute of Scientific and Technical Information of China (English)

    Wan-Yee Lau; Eric C. H. Lai; Stephanie H. Y. Lau

    2009-01-01

    BACKGROUND: Following curative treatment for hepato-cellular carcinoma (HCC), 50%-90% of postoperative death is due to recurrent disease. Intra-hepatic recurrence is frequently the only site of recurrence. Thus, any neoadjuvant or adjuvant therapy, which can decrease or delay the incidence of intra-hepatic recurrence, or any cancer chemoprevention which can prevent a new HCC from developing in the liver remnant, will improve the results of liver resection. This article systematically reviewed the current evidence of neoadjuvant, adjuvant, and chemoprevention in partial hepatectomy of HCC. DATA SOURCES: Studies were identiifed by searching MEDLINE and PubMed databases for articles from January 1990 to November 2008 using the keywords"hepatocellular carcinoma", "hepatectomy", "adjuvant therapy", "neoadjuvant therapy", and "regional therapy". Additional papers and book chapters were identiifed by a manual search of the references from the key articles. RESULTS: Neoadjuvant transarterial chemoembolization or adjuvant regional transarterial chemotherapy± embolization+systemic chemotherapy did not add beneift. Both adjuvant transarterial radioembolization with 131I-lipiodol and adjuvant systemic interferon showed promising results. However, there were only a limited number of such studies.CONCLUSIONS: Further randomized controlled studies need to be carried out. Currently, there is no consensus on a standard neoadjuvant/adjuvant/chemoprevention therapy in partial hepatectomy for HCC.

  14. Chemopreventive efficacy of menthol on carcinogen-induced cutaneous carcinoma through inhibition of inflammation and oxidative stress in mice.

    Science.gov (United States)

    Liu, Zhaoguo; Shen, Cunsi; Tao, Yu; Wang, Siliang; Wei, Zhonghong; Cao, Yuzhu; Wu, Hongyan; Fan, Fangtian; Lin, Chao; Shan, Yunlong; Zhu, Pingting; Sun, Lihua; Chen, Chen; Wang, Aiyun; Zheng, Shizhong; Lu, Yin

    2015-08-01

    Inflammation and oxidative stress have been implicated in various pathological processes including skin tumorigenesis. Skin cancer is the most common form of cancer responsible for considerable morbidity and mortality, the treatment progress of which remains slow though. Therefore, chemoprevention and other strategies are being considered. Menthol has shown high anticancer activity against various human cancers, but its effect on skin cancer has never been evaluated. We herein investigated the chemopreventive potential of menthol against 9,10-dimethylbenz[a]anthracene (DMBA)/12-O-tetradecanoylphorbol-13-acetate (TPA)-induced inflammation, oxidative stress and skin carcinogenesis in female ICR mice. Pretreatment with menthol at various doses significantly suppressed tumor formation and growth, and markedly reduced tumor incidence and volume. Moreover, menthol inhibited TPA-induced skin hyperplasia and inflammation, and significantly suppressed the expression of cyclooxygenase-2 (COX-2). Furthermore, pretreatment with menthol inhibited the formation of reactive oxygen species and affected the activities of a battery of antioxidant enzymes in the skin. The expressions of NF-κB, Erk and p38 were down-regulated by menthol administration. Thus, inflammation and oxidative stress collectively played a crucial role in the chemopreventive efficacy of menthol on the murine skin tumorigenesis.

  15. A family of quantum protocols

    CERN Document Server

    Devetak, I; Winter, A

    2003-01-01

    We introduce two dual, purely quantum protocols: for entanglement distillation assisted by quantum communication (``mother'' protocol) and for entanglement assisted quantum communication (``father'' protocol). We show how a large class of ``children'' protocols (including many previously known ones) can be derived from the two by direct application of teleportation or super-dense coding. Furthermore, the parent may be recovered from most of the children protocols by making them ``coherent''. We also summarize the various resource trade-offs these protocols give rise to.

  16. Explicit Protocol for Deterministic Entanglement Concentration

    Institute of Scientific and Technical Information of China (English)

    GU Yong-Jian; GAO Peng; GUO Guang-Can

    2005-01-01

    @@ We present an explicit protocol for extraction of an EPR pair from two partially entangled pairs in a deterministic fashion via local operations and classical communication. This protocol is constituted by a local measurement described by a positive operator-valued measure (POVM), one-way classical communication, and a corresponding local unitary operation or a choice between the two pairs. We explicitly construct the required POVM by the analysis of the doubly stochastic matrix connecting the initial and the final states. Our scheme might be useful in future quantum communication.

  17. Social Protocols for Agile Virtual Teams

    Science.gov (United States)

    Picard, Willy

    Despite many works on collaborative networked organizations (CNOs), CSCW, groupware, workflow systems and social networks, computer support for virtual teams is still insufficient, especially support for agility, i.e. the capability of virtual team members to rapidly and cost efficiently adapt the way they interact to changes. In this paper, requirements for computer support for agile virtual teams are presented. Next, an extension of the concept of social protocol is proposed as a novel model supporting agile interactions within virtual teams. The extended concept of social protocol consists of an extended social network and a workflow model.

  18. Social Protocols for Agile Virtual Teams

    CERN Document Server

    Picard, Willy

    2011-01-01

    Despite many works on collaborative networked organizations (CNOs), CSCW, groupware, workflow systems and social networks, computer support for virtual teams is still insufficient, especially support for agility, i.e. the capability of virtual team members to rapidly and cost efficiently adapt the way they interact to changes. In this paper, requirements for computer support for agile virtual teams are presented. Next, an extension of the concept of social protocol is proposed as a novel model supporting agile interactions within virtual teams. The extended concept of social protocol consists of an extended social network and a workflow model.

  19. The covert channel over HTTP protocol

    Science.gov (United States)

    Graniszewski, Waldemar; Krupski, Jacek; Szczypiorski, Krzysztof

    2016-09-01

    The paper presents a new steganographic method - the covert channel is created over HTTP protocol header, i.e. trailer field. HTTP protocol is one of the most frequently used in the Internet. The popularity of the Web servers and network traffic from, and to them, is one of the requirements for undetectable message exchange. To study this kind of the information hiding technique an application in Javascript language based on the Node.js framework was written. The results of the experiment that was performed to send a message in the covert channel are also presented.

  20. Chemopreventive and renal protective effects for docosahexaenoic acid (DHA: implications of CRP and lipid peroxides

    Directory of Open Access Journals (Sweden)

    Darweish MM

    2009-04-01

    Full Text Available Abstract Background The fish oil-derived ω-3 fatty acids, like docosahexanoic (DHA, claim a plethora of health benefits. We currently evaluated the antitumor effects of DHA, alone or in combination with cisplatin (CP in the EAC solid tumor mice model, and monitored concomitant changes in serum levels of C-reactive protein (CRP, lipid peroxidation (measured as malondialdehyde; MDA and leukocytic count (LC. Further, we verified the capacity of DHA to ameliorate the lethal, CP-induced nephrotoxicity in rats and the molecular mechanisms involved therein. Results EAC-bearing mice exhibited markedly elevated LC (2-fold, CRP (11-fold and MDA levels (2.7-fold. DHA (125, 250 mg/kg elicited significant, dose-dependent reductions in tumor size (38%, 79%; respectively, as well as in LC, CRP and MDA levels. These effects for CP were appreciably lower than those of DHA (250 mg/kg. Interestingly, DHA (125 mg/kg markedly enhanced the chemopreventive effects of CP and boosted its ability to reduce serum CRP and MDA levels. Correlation studies revealed a high degree of positive association between tumor growth and each of CRP (r = 0.85 and leukocytosis (r = 0.89, thus attesting to a diagnostic/prognostic role for CRP. On the other hand, a single CP dose (10 mg/kg induced nephrotoxicity in rats that was evidenced by proteinuria, deterioration of glomerular filtration rate (GFR, -4-fold, a rise in serum creatinine/urea levels (2–5-fold after 4 days, and globally-induced animal fatalities after 7 days. Kidney-homogenates from CP-treated rats displayed significantly elevated MDA- and TNF-α-, but reduced GSH-, levels. Rats treated with DHA (250 mg/kg, but not 125 mg/kg survived the lethal effects of CP, and showed a significant recovery of GFR; while their homogenates had markedly-reduced MDA- and TNF-α-, but -increased GSH-levels. Significant association was detected between creatinine level and those of MDA (r = 0.81, TNF-α r = 0.92 and GSH (r = -0

  1. CCPA: Component-based communication protocol architecture for embedded systems

    Institute of Scientific and Technical Information of China (English)

    DAI Hong-jun; CHEN Tian-zhou; CHEN Chun

    2005-01-01

    For increased and various communication requirements of modem applications on embedded systems, general purpose protocol stacks and protocol models are not efficient because they are fixed to execute in the static mode. We present the Component-Based Communication Protocol Architecture (CCPA) to make communication dynamic and configurable. It can develop, test and store the customized components for flexible reuse. The protocols are implemented by component assembly and support by configurable environments. This leads to smaller memory, more flexibility, more reconfiguration ability, better concurrency, and multiple data channel support.

  2. A Flexible Improvement for Ping-Pong Protocol

    Institute of Scientific and Technical Information of China (English)

    LIU Yu; HUA Sha; WANG Xiao-Xin; LI Yue; YE Jun; LI Jun

    2006-01-01

    A deterministic quantum communication protocol, called the ping-pong protocol, has been represented by Bostr(o)m and Felbinger [Phys. Rev. Lett. 89 (2002) 187902]. Based on an entangled pair of photons, it allows asymptotically secure key distribution and quasi-secure direct communication. However, it was concluded from our previous research that the experiment realization of this protocol requires two optic paths strictly equivalent for interferometry. Here we propose an improved protocol, which is more flexible and secure for conceivable applications. Its feasibility and security are also discussed.

  3. Security Analysis of Routing Protocols in Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Mohammad Sadeghi

    2012-01-01

    Full Text Available In this paper, I describe briefly some of the different types of attacks on wireless sensor networks such as Sybil, HELLO, Wormhole and Sinkhole attacks. Then I describe security analysis of some major routing protocols in wireless sensor network such as Directed Diffusion, TinyOS beaconing, geographic and Rumor routings in term of attacks and security goals. As a result I explain some secure routing protocols for wireless sensor network and is discussed briefly some methods and policy of these protocols to meet their security requirements. At last some simulation results of these protocols that have been done by their designer are mentioned.

  4. Model Checking Electronic Commerce Security Protocols Based on CTL

    Institute of Scientific and Technical Information of China (English)

    XIAO De-qin; ZHANG Huan-guo

    2005-01-01

    We present a model based on Computational Temporal Logic (CTL) methods for verifying security requirements of electronic commerce protocols. The model describes formally the authentication, confidentiality integrity,non-repudiation, denial of service and access control of the electronic commerce protocols. We illustrate as case study a variant of the Lu-Smolka protocol proposed by Lu-Smolka.Moreover, we have discovered two attacks that allow a dishonest user to purchase a good debiting the amount to another user. And also, we compared our work with relative research works and found that the formal way of this paper is more general to specify security protocols for E-Commerce.

  5. Symmetric cryptographic protocols

    CERN Document Server

    Ramkumar, Mahalingam

    2014-01-01

    This book focuses on protocols and constructions that make good use of symmetric pseudo random functions (PRF) like block ciphers and hash functions - the building blocks for symmetric cryptography. Readers will benefit from detailed discussion of several strategies for utilizing symmetric PRFs. Coverage includes various key distribution strategies for unicast, broadcast and multicast security, and strategies for constructing efficient digests of dynamic databases using binary hash trees.   •        Provides detailed coverage of symmetric key protocols •        Describes various applications of symmetric building blocks •        Includes strategies for constructing compact and efficient digests of dynamic databases

  6. Mitosis Methods & Protocols

    Directory of Open Access Journals (Sweden)

    CarloAlberto Redi

    2010-06-01

    Full Text Available Mitosis Methods & Protocols Andrew D. McAinsh (Edt Humana press, Totowa, New Jersey (USA Series: Springer Protocols Methods in Molecular Biology, Volume 545, 2009 ISBN: 978-1-60327-992-5   It is quite clear from the contents of this book that the remarkably fascinating phenomenon of mitosis (that captured, and still is capturing, the attention of entire generations of scientists is still open to research. This is mainly due to our lack of knowledge of so many multifaced events of this extraordinarly complex process. The reader giving a glace through the Contents and Contributors sections is speechless: All of the first-class models (i.e., budding yeast, Caenorabditis, Drosophila, Xenopus and Human are presented..... 

  7. Cognitive Protocol Stack Design

    Science.gov (United States)

    2015-12-30

    SPONSORING/MONITORING AGENCY NAME(S) AND ADDRESS (ES) U.S. Army Research Office P.O. Box 12211 Research Triangle Park , NC 27709-2211 cognitive...related to mobility and topology changes in a wireless multi-hop ad hoc network. (xv) We used a cross-layer formulation to design transmission...the transmission parameters, the implemented protocol and the network topology . The solution adopted involves a heuristic metric to measure how the

  8. Dysphonia risk screening protocol

    Directory of Open Access Journals (Sweden)

    Katia Nemr

    2016-03-01

    Full Text Available OBJECTIVE: To propose and test the applicability of a dysphonia risk screening protocol with score calculation in individuals with and without dysphonia. METHOD: This descriptive cross-sectional study included 365 individuals (41 children, 142 adult women, 91 adult men and 91 seniors divided into a dysphonic group and a non-dysphonic group. The protocol consisted of 18 questions and a score was calculated using a 10-cm visual analog scale. The measured value on the visual analog scale was added to the overall score, along with other partial scores. Speech samples allowed for analysis/assessment of the overall degree of vocal deviation and initial definition of the respective groups and after six months, the separation of the groups was confirmed using an acoustic analysis. RESULTS: The mean total scores were different between the groups in all samples. Values ranged between 37.0 and 57.85 in the dysphonic group and between 12.95 and 19.28 in the non-dysphonic group, with overall means of 46.09 and 15.55, respectively. High sensitivity and specificity were demonstrated when discriminating between the groups with the following cut-off points: 22.50 (children, 29.25 (adult women, 22.75 (adult men, and 27.10 (seniors. CONCLUSION: The protocol demonstrated high sensitivity and specificity in differentiating groups of individuals with and without dysphonia in different sample groups and is thus an effective instrument for use in voice clinics.

  9. Protocol Independent Multicast Based States Allocation

    Directory of Open Access Journals (Sweden)

    G Hemalatha

    2012-02-01

    Full Text Available In this paper the Protocol Independent Multicast (PIM protocol is being used. The PIM protocol avoids the packet drop and diverting problem. The PIM protocol is not dependent on any specific unicast routing protocol. It is IP routing independent protocol. The PIM uses the unicast and multicast information to create a distribution tree along the reverse path from the receivers towards the source. The PIM protocol consists of three modes such as sparse mode, dense mode and bidirectional mode. The sparse mode is used to sends the file from router to a receiver. The dense mode is used to sends the file from router to multiple receivers. The bidirectional mode is used to sends the message from router to sender and then continue the other process depending on the sender requirements. The client sends the file from sender to destination via the router. First the sender selects the file name and receiver name for transmission. Then the state is assigned automatically depend upon the user selection. The state can be defined by the number of destination selected to transmit the file from the source. If the sender selects single destination, it will assign “Without forwarding state router” for transmission. Otherwise it will assign “Forwarding state router” for transmission. If the receiver is not available, the router sends a message to sender such that “the requested receiver is not available”. Then the client will decide the file is transfer or not, it will reply with transfer the file, then the file will be transferred until the file will be discarded at client side. If the sender tries the same process after two times, the router will display the warning message as “the requested receiver is not available, this file will be discarded at client side”. Then it continues the other process.

  10. Performance Evaluation of MANET Routing Protocols

    Directory of Open Access Journals (Sweden)

    Hrituparna Paul

    2012-07-01

    Full Text Available The task of finding and sustaining routes in Mobile Ad-hoc Networks (MANETS is an important factor in determining the efficiency of any MANET protocol. MANET characteristically is an autonomous system of mobile nodes connected by wireless links without any centralised infrastructure. Absence of fixed infrastructures and host mobility thus network may experience rapid and unpredictable topology changes. Hence, routing is required in order to perform communication among the entire network. There are several routing protocols namely proactive, reactive and hybrid etc. In this paper we will discuss the active research work on these routing protocols and its performance evaluation. To this end, we adopt a simulation approach, which is more suitable to this kind of analysis

  11. Efficient Controlled Quantum Secure Direct Communication Protocols

    Science.gov (United States)

    Patwardhan, Siddharth; Moulick, Subhayan Roy; Panigrahi, Prasanta K.

    2016-07-01

    We study controlled quantum secure direct communication (CQSDC), a cryptographic scheme where a sender can send a secret bit-string to an intended recipient, without any secure classical channel, who can obtain the complete bit-string only with the permission of a controller. We report an efficient protocol to realize CQSDC using Cluster state and then go on to construct a (2-3)-CQSDC using Brown state, where a coalition of any two of the three controllers is required to retrieve the complete message. We argue both protocols to be unconditionally secure and analyze the efficiency of the protocols to show it to outperform the existing schemes while maintaining the same security specifications.

  12. Chapter 15: Commercial New Construction Protocol

    Energy Technology Data Exchange (ETDEWEB)

    Keates, S.

    2014-09-01

    This protocol is intended to describe the recommended method when evaluating the whole-building performance of new construction projects in the commercial sector. The protocol focuses on energy conservation measures (ECMs) measures (or packages of measures) where evaluators can best analyze impacts using building simulation. These ECMs typically require the use of calibrated building simulations under Option D of the International Performance Measurement and Verification Protocol. Examples of such measures include Leadership in Energy and Environmental Design building certification, novel and/or efficient heating, ventilation, and air conditioning system designs, and extensive building controls systems. In general, it is best to evaluate any ECM (or set of measures) expected to significantly interact with other systems within the building and with savings sensitive to seasonal variations in weather.

  13. Probabilistic protocols in quantum information science: Use and abuse

    Science.gov (United States)

    Caves, Carlton

    2014-03-01

    Protocols in quantum information science often succeed with less than unit probability, but nonetheless perform useful tasks because success occurs often enough to make tolerable the overhead from having to perform the protocol several times. Any probabilistic protocol must be analyzed from the perspective of the resources required to make the protocol succeed. I present results from analyses of two probabilistic protocols: (i) nondeterministic (or immaculate) linear amplification, in which an input coherent state is amplified some of the time to a larger-amplitude coherent state, and (ii) probabilistic quantum metrology, in which one attempts to improve estimation of a parameter (or parameters) by post-selecting on a particular outcome. The analysis indicates that there is little to be gained from probabilistic protocols in these two situations.

  14. RPWCN or Roaming Protocol in Wireless Community Network

    Directory of Open Access Journals (Sweden)

    Thomas Djotio

    2014-03-01

    Full Text Available Many Roaming protocols have already been proposed in wireless community networks (WCN, but none has yet been the subject of standardization. Also, the networks topologies required for deployments are all very costly when it is necessary to take into account the socio-economic conditions of developing countries. In this paper, we propose the RPWCN Protocol (Roaming Protocol in Wireless Community Network which design logic is strongly inspired by the functioning of the Roaming Protocol in GSM. The WCN architecture on which we modelled our Protocol takes into account the socio-economic conditions of developing countries. After the modelling of the RPWCN Protocol, the AVISPA tool has been solicited for its validation

  15. An Internet Key Exchange Protocol Based on Public Key Infrastructure

    Institute of Scientific and Technical Information of China (English)

    朱建明; 马建峰

    2004-01-01

    Internet key exchange (IKE) is an automated key exchange mechanism that is used to facilitate the transfer of IPSec security associations (SAs). Public key infrastructure (PKI) is considered as a key element for providing security to new distributed communication networks and services. In this paper, we concentrate on the properties of the protocol of Phase 1 IKE. After investigating IKE protocol and PKI technology, we combine IKE protocol and PKI and present an implementation scheme of the IKE based on PKI. Then, we give a logic analysis of the proposed protocol with the BAN-logic and discuss the security of the protocol. The result indicates that the protocol is correct and satisfies the security requirements of Internet key exchange.

  16. Routing Protocol Performance Issues and Evaluation Considerations in MANET

    Directory of Open Access Journals (Sweden)

    P.Venkata Maheswara,

    2013-07-01

    Full Text Available Mobile nodes in Wire less a d-hoc networ k need to operate as routers in or d er to maintain the informa tion ab out network connectivity as there is no centralized infrastructure. Therefore,Routing Protocols are required which could adapt dynamically to the changing topologies and works at low data rates. As are sult, there arises a need for the compreh ensive performance evaluation of the ad-doc routing protocols in same frame work to under stand their comparative merits and suitability for deployment in different scenarios. In this paper the protocols suite selected for comparison are AODV, DSR, TORA and OLSR ad- hoc routing protocols, as these were the most promising from all other protocols. The performance of these protocols is evaluated through exhaustive simulations using the OPNET Model network simulator under different parameters like routing over head, delay , throughput and network load under varying the mobile nodes .

  17. DESIGN OF PROTOCOL IN UNDERWATER WIRELESS SENSOR NETWORKS

    Directory of Open Access Journals (Sweden)

    S. Fathima

    2015-10-01

    Full Text Available In this work we designed a routing protocol to overcome upcoming challenges in under water wireless sensor networks. The routing protocol designed for specific roles leads to issues in the network. The major issues for development of routing protocol for underwater sensor network are harsh deployment environment, low bandwidth, high propagation delay, low bandwidth, requires high bandwidth energy, temporary losses, fouling and corrosion and high bit error rates. In this project the certain issues to be rectified are low bandwidth, energy efficiency and data delivery. The limitations existing routing protocols are low data delivery, data delivery ratio, energy efficiency, bandwidth efficiency and reliability. Design of three new protocol is to overcome the limitations of existing protocols in underwater wireless sensor networks.

  18. AN INTERACTIVE VISUALIZATION TOOL FOR ANIMATING BEHAVIOR OF CRYPTOGRAPHIC PROTOCOLS

    Directory of Open Access Journals (Sweden)

    Mabroka Maeref

    2015-03-01

    Full Text Available Cryptography and Network Security is a difficult subject to understand, mainly because of the complexity of security protocols and the mathematical rigour required to understand encryption algorithms. Realizing the need for an interactive visualization tool to facilitate the understanding of cryptographic concepts and protocols, several tools had been developed. However, these tools cannot be easily adapted to animate different protocols. The aim of this paper is to propose an interactive visualization tool, called the Cryptographic Protocol Animator (CPAnim. The tool enables a student to specify a protocol and gain knowledge about the impact of its behavior. The protocol is specified by using a scenario-based approach and it is demonstrated as a number of scenes displaying a complete scenario. The effectiveness of this tool was tested using an empirical evaluation method. The results show that this tool was effective in meeting its learning objectives.

  19. E-Cash Payment Protocols

    Directory of Open Access Journals (Sweden)

    Shweta Srivastava

    2012-09-01

    Full Text Available E-cash is a payment system designed and implemented for making purchases over open networks such as the Internet. Need of a payment system which enables the electronic transactions are growing at the same time that the use of Internet is growing in our daily life. Present days electronic payment systems have a major problem, they cannot handle the security and the users anonymity and at the same time these systems are secure on the cost of their users anonymity. This paper shows the payment protocols for digital cash and discusses how a digital cash system can be formed by presenting a few of the present days digital cash systems in details. We also provide a comparison and determine them together to see which one of them fulfils the properties for digital cash and the required security level.

  20. Secure Multi-Player Protocols

    DEFF Research Database (Denmark)

    Fehr, Serge

    secret sharing in terms of simple algebraic conditions on the integer sharing coefficients, and we propose a black-box secret sharing scheme with minimal expansion factor. Note that, in contrast to the classical field-based secret sharing schemes, a black-box secret sharing scheme allows to share......, MPC can be based on arbitrary finite rings. This is in sharp contrast to the literature where essentially all MPC protocols require a much stronger mathematical structure, namely a field. Apart from its theoretical value, this can lead to efficiency improvements since it allows a greater freedom...... ones. We also construct a noninteractive distributed-verifier proof of circuit satisfiability, which—in principle—allows to prove anything that can be proven without giving away the proof....

  1. A review of the dietary flavonoid, kaempferol on human health and cancer chemoprevention.

    Science.gov (United States)

    Chen, Allen Y; Chen, Yi Charlie

    2013-06-15

    Kaempferol is a polyphenol antioxidant found in fruits and vegetables. Many studies have described the beneficial effects of dietary kaempferol in reducing the risk of chronic diseases, especially cancer. Epidemiological studies have shown an inverse relationship between kaempferol intake and cancer. Kaempferol may help by augmenting the body's antioxidant defence against free radicals, which promote the development of cancer. At the molecular level, kaempferol has been reported to modulate a number of key elements in cellular signal transduction pathways linked to apoptosis, angiogenesis, inflammation, and metastasis. Significantly, kaempferol inhibits cancer cell growth and angiogenesis and induces cancer cell apoptosis, but on the other hand, kaempferol appears to preserve normal cell viability, in some cases exerting a protective effect. The aim of this review is to synthesize information concerning the extraction of kaempferol, as well as to provide insights into the molecular basis of its potential chemo-preventative activities, with an emphasis on its ability to control intracellular signaling cascades that regulate the aforementioned processes. Chemoprevention using nanotechnology to improve the bioavailability of kaempferol is also discussed.

  2. Arsenic immunotoxicity and immunomodulation by phytochemicals: potential relations to develop chemopreventive approaches.

    Science.gov (United States)

    Ramos Elizagaray, Sabina I; Soria, Elio A

    2014-01-01

    Arsenic (As) contaminates drinking water worldwide, and As exposure, hypersensitivity and deficiency are involved in the immunopathogenesis of various health problems. Its chemoprevention thus has a high health impact. Given its oxidative potential, antioxidant compounds are good candidates to counteract arsenic's deleterious effects on humans. Phytochemicals (e.g., phenolics, carotenoids, etc.) act through free radical chelation activity and regulation of cellular targets. Consequently, they are appropriate for developing anti-As strategies derived from plants, and Argentinean flora is rich in useful species. Several molecular pathways involved in immune regulation are at the same time targets of exogenous agents, and oxidative stress itself is a modulating phenomenon of immunity. Since xenohormesis has been described as the organic enhancement of resistance to stress conditions (e.g., oxidation, pollution, etc.) by consuming xenobiotics, immunoxenohormesis implies also defense improvement. This review focuses on recent patents on the development of vegetable redox-related immunomodulating agents, which might be applied in As-induced dysfunctions, with their scientific basis being reviewed.

  3. Molecular aspects and chemoprevention of dimethylaminoazobenzene-induced hepatocarcinogenesis: A review.

    Science.gov (United States)

    Thomas, Nisha Susan; George, Kiran; Namasivayam, Nalini

    2016-01-01

    The lipophilic azo dye dimethylaminoazobenzene (DAB) is a potent hepatocarcinogen accounted as a group-2B carcinogen causing risk to humans. DAB is commonly used as a coloring agent in food, pharmaceuticals, beverages, soap and polishes. The exploration of DAB-induced hepatocarcinogenesis in animal models helped to an extent to perceive the histological, biochemical and molecular mechanisms of DAB carcinogenesis and also the severity of DAB exposure to humans. In experimental animal models, it is well-proved that the procarcinogen DAB is predominantly metabolized by cytochrome P450 enzymes giving rise to the formation of toxic electrophiles and reactive oxygen species (ROS), which further forms DNA adducts leading to the development of hepatic tumors. Recently, research evidence suggests that dietary phytochemicals and plant polyphenols are promising agents to control the incidence of DAB-induced hepatocarcinogenesis by preventing the generation of toxic electrophiles and ROS thereby inhibiting the formation of DNA adducts. This review highlights the role of specific dietary factors, biotransformation of DAB, phenotypic and genotypic alterations, and significance of certain chemopreventive agents against DAB-induced hepatocarcinogenesis.

  4. Nitroxides as antioxidants – possibilities of their application in chemoprevention and radioprotection

    Directory of Open Access Journals (Sweden)

    Sabina Tabaczar

    2011-01-01

    Full Text Available Nitroxides as stabile organic radicals were used initially as spin labels in spectroscopy of electron paramagnetic resonance (EPR with respect to parameters such as pH of an intercellular environment, oxygenation of cells and tissues, fluidity of biological membranes, conformational state and topography of proteins. Nitroxides have also been used in biology and medicine as contrast agents in magnetic resonance imaging (MRI. When their antioxidant activities were discovered, an era of research on the potential utility of these agents began. Nitroxides can modulate the redox state of the cell by participation in oxidation/reduction reactions. Therefore, they are extensively examined in various models of oxidative stress. The antioxidant effect of nitroxides is a result of their ability to catalyze dismutation of superoxide radical (superoxide dismutase-like activity, inhibit lipid peroxidation, prevent Fenton and Haber-Weiss reactions by oxidation of transition metal ions to a higher oxidative state, and confer catalase-like activity on heme proteins. In the present paper the antioxidative mechanisms of nitroxides are presented. The relation between structure, function and the rate of nitroxide reduction inside cells and tissues is also presented. The application of nitroxides in chemoprevention and radioprotection is discussed.

  5. The 4Ps of Breast Cancer Chemoprevention: Putting Proven Principles into Practice.

    Science.gov (United States)

    Jordan, V Craig

    2017-04-01

    The pioneering Royal Marsden Tamoxifen Prevention Trial recruited 2,471 eligible high-risk women to be randomized to either placebo or tamoxifen (20 mg daily) for 8 years. Breast cancer incidence was evaluated at a median of 18.4 years from the start of the study. There was a 32% reduction in estrogen/progesterone receptor (ER/PR)-positive breast cancers after tamoxifen treatment finished. Translational research, to study "the good, the bad, and the ugly of tamoxifen" in the 1980s, subsequently ensured women's safety from possible increases in osteoperosis, coronary heart disease, and endometrial cancer. Other tamoxifen chemoprevention trials followed. The result of laboratory research was the unanticipated discovery of raloxifene to prevent osteoporosis and breast cancer at the same time. A new group of medicines, now known as selective ER modulators, was established. Indeed, the ability to prevent or delay multiple diseases with a single cheap medicine has the potential to alleviate pressure on health care systems that are overwhelmed. It is a priority to educate physicians appropriately to apply recommended proven medicines as preventives. Cancer Prev Res; 10(4); 219-22. ©2017 AACRSee related article by Detre, et al., Cancer Prev Res 2017;10(3):171-6.

  6. Chemopreventive effect of quercetin in MNU and testosterone induced prostate cancer of Sprague-Dawley rats.

    Science.gov (United States)

    Sharmila, Govindaraj; Athirai, Thavadurainathan; Kiruthiga, Balakrishnan; Senthilkumar, Kalimuthu; Elumalai, Perumal; Arunkumar, Ramachandran; Arunakaran, Jagadeesan

    2014-01-01

    Prostate cancer becomes an ideal target for chemoprevention because of its high incidence and extended natural history. The consumption of quercetin (plant flavonoid) in diet is associated with decreased risk of disease and many cancers but then this was not elucidated in prostate malignancy. Hence, a study in which the male Sprague-Dawley rats were induced prostate cancer by hormone (testosterone) and carcinogen (MNU) and simultaneously supplemented with quercetin (200 mg/Kg body weight) thrice a week, was conducted. After the treatment period, rats were killed; ventral and dorsolateral lobes of the prostate were dissected. Histology and oxidative stress markers LPO, H2O2, and antioxidant GSH level were measured in both lobes. The lipid peroxidation, H2O2, in (MNU+T) treated rats were increased and GSH level was decreased, whereas simultaneous quercetin-treated rats reverted back to normal level in both ventral and dorsolateral regions. The different patterns of PIN were observed with associated hyperplasia and dysplasia; changes in these regions and the occurrence of this lesion were reduced in simultaneous quercetin-treated rats. The study concluded that dietary quercetin prevented MNU + T-induced prostate carcinogenesis on both ventral and dorsolateral lobes of Sprague-Dawley rats.

  7. Salvianolic Acid B, a Potential Chemopreventive Agent, for Head and Neck Squamous Cell Cancer

    Directory of Open Access Journals (Sweden)

    Yuan Zhao

    2011-01-01

    Full Text Available Head and neck squamous cell cancer (HNSCC is one of the top ten cancers in the United States. The survival rate of HNSCC has only marginally improved over the last two decades. In addition, African-American men bear a disproportionate burden of this preventable disease. Therefore, a critical challenge of preventive health approaches is warranted. Salvianolic acid B (Sal-B isolated from Salvia miltiorrhiza Bge, which is a well-know Chinese medicines has been safely used to treat and prevent aging diseases for thousand of years. Recently, the anticancer properties of Sal-B have received more attention. Sal-B significantly inhibits or delays the growth of HNSCC in both cultured HNSCC cells and HNSCC xenograft animal models. The following anticancer mechanisms have been proposed: the inhibition of COX-2/PGE-2 pathway, the promotion of apoptosis, and the modulation of angiogenesis. In conclusion, Sal-B is a potential HNSCC chemopreventive agent working through antioxidation and anti-inflammation mechanisms.

  8. Salvianolic Acid B, a Potential Chemopreventive Agent, for Head and Neck Squamous Cell Cancer

    Science.gov (United States)

    Zhao, Yuan; Guo, Yinhan; Gu, Xinbin

    2011-01-01

    Head and neck squamous cell cancer (HNSCC) is one of the top ten cancers in the United States. The survival rate of HNSCC has only marginally improved over the last two decades. In addition, African-American men bear a disproportionate burden of this preventable disease. Therefore, a critical challenge of preventive health approaches is warranted. Salvianolic acid B (Sal-B) isolated from Salvia miltiorrhiza Bge, which is a well-know Chinese medicines has been safely used to treat and prevent aging diseases for thousand of years. Recently, the anticancer properties of Sal-B have received more attention. Sal-B significantly inhibits or delays the growth of HNSCC in both cultured HNSCC cells and HNSCC xenograft animal models. The following anticancer mechanisms have been proposed: the inhibition of COX-2/PGE-2 pathway, the promotion of apoptosis, and the modulation of angiogenesis. In conclusion, Sal-B is a potential HNSCC chemopreventive agent working through antioxidation and anti-inflammation mechanisms. PMID:21209716

  9. Potent chemopreventive effect of mangiferin on lung carcinogenesis in experimental Swiss albino mice

    Directory of Open Access Journals (Sweden)

    Peramaiyan Rajendran

    2014-01-01

    Full Text Available Aim of the Study: In the present study the effects of mangiferin were tested against lung cancer-bearing mice in both the pre-initiation and post-initiation periods. Materials and Methods: Healthy male Swiss albino mice (6-8 weeks old were used throughout the study. The animals were treated with mangiferin (100 mg/kg body weight dissolved in corn oil two weeks before (pre-initiation and the twelfth week after (post-initiation the establishment of B (a P (50 mg/kg body weight-induced lung carcinoma. Results: The body weight decreased and the lung weight and levels of xenobiotic and liver marker enzymes markedly increased in the carcinogen-administered animals; and mangiferin treatment brought the values of these parameters back to the near-normal ones. The activities of lysosomal enzymes in the animals with B (a P-induced experimental lung carcinogenesis were also assessed. In these animals there was an increase in the activities of lysosomal enzymes such as acidphosphatase, β-glucuronidase, N-acetyl glucosaminidase, and β-galactosidase. Conclusion: Supplementation with mangiferin attenuated all these alterations, thus indicating its anticancer effect. Overall, the above data showed that the anticancer effect of mangiferin as a chemopreventive agent was pronounced.

  10. Development of in vitro models for cellular and molecular studies in toxicology and chemoprevention

    Energy Technology Data Exchange (ETDEWEB)

    Mace, K.; Offord, E.A.; Harris, C.C.; Pfeifer, A.M.A. [Nestle Research Center, Lausanne (Switzerland)

    1998-12-31

    Many natural dietary phytochemicals found compounds found in fruits, vegetables, spices and tea have been shown in recent years to be protective against cancer in various animal models. In the light of the potential impact of these compounds on human health it is important to elucidate the mechanisms involved. We therefore developed and characterized relevant in vitro models using immortalized human epithelial cell lines derived from target tissues in carcinogenesis, such as lung, liver and colon. Assays were established, allowing the evaluation of the cytotoxic and genotoxic effects of various procarcinogens, including nitrosamines, mycotoxins and heterocyclic amines on these metabolically-competent human epithelial cell lines. These cellular models appeared to be a useful tool to study the capacity of certain food components to block the initiation stage of carcinogenesis. The ability of carnosol and carnosic acid from rosemary as well as the synthetic dithiolethione, oltipraz, to block the formation of DNA adducts, and their effects on the expression of phase I and phase II enzymes was investigated. We have observed that both rosemary extracts and oltiprax inhibited benzo(a)pyrene- or aflatoxin B{sub 1}-induced DNA adduct formation by strongly inhibiting CYP{sub 450} activities and inducing the expression of glutathione S-transferase. These results in human cell models give some insight into the different mechanisms involved in the chemopreventive action of both natural and synthetic compounds in relation to phase I and phase II enzymes. (orig.)

  11. Controlled Delegation Protocol in Mobile RFID Networks

    Directory of Open Access Journals (Sweden)

    Yang MingHour

    2010-01-01

    Full Text Available To achieve off-line delegation for mobile readers, we propose a delegation protocol for mobile RFID allowing its readers access to specific tags through back-end server. That is to say, reader-tag mutual authentication can be performed without readers being connected to back-end server. Readers are also allowed off-line access to tags' data. Compared with other delegation protocols, our scheme uniquely enables back-end server to limit each reader's reading times during delegation. Even in a multireader situation, our protocol can limit reading times and reading time periods for each of them and therefore makes back-end server's delegation more flexible. Besides, our protocol can prevent authorized readers from transferring their authority to the unauthorized, declining invalid access to tags. Our scheme is proved viable and secure with GNY logic; it is against certain security threats, such as replay attacks, denial of service (DoS attacks, Man-in-the-Middle attacks, counterfeit tags, and breaches of location and data privacy. Also, the performance analysis of our protocol proves that current tags can afford the computation load required in this scheme.

  12. A Lightweight Buyer-Seller Watermarking Protocol

    Directory of Open Access Journals (Sweden)

    Yongdong Wu

    2008-01-01

    Full Text Available The buyer-seller watermarking protocol enables a seller to successfully identify a traitor from a pirated copy, while preventing the seller from framing an innocent buyer. Based on finite field theory and the homomorphic property of public key cryptosystems such as RSA, several buyer-seller watermarking protocols (N. Memon and P. W. Wong (2001 and C.-L. Lei et al. (2004 have been proposed previously. However, those protocols require not only large computational power but also substantial network bandwidth. In this paper, we introduce a new buyer-seller protocol that overcomes those weaknesses by managing the watermarks. Compared with the earlier protocols, ours is n times faster in terms of computation, where n is the number of watermark elements, while incurring only O(1/lN times communication overhead given the finite field parameter lN. In addition, the quality of the watermarked image generated with our method is better, using the same watermark strength.

  13. Operational protocols for controlling accelerator equipment

    Energy Technology Data Exchange (ETDEWEB)

    Bailey, R.; Baribaud, G.; Benincasa, G.P.; Burla, P.; Casalegno, L.; Coudert, G.; Gelato, G.; Kuhn, H.K.; Saban, R.; Spinks, A. (European Organization for Nuclear Research, Geneva (Switzerland). LEP Div.)

    1990-08-01

    The equipment used to operate an accelerator is varied. However, the different devices may be divided into a limited number of classes for which operational protocols can be defined. Operational protocols permit: (i) a uniform operation, (ii) a clear definition of responsibility between the various specialists, (iii) independent development of programs and use of the most appropriate technology, (iv) the change of hardware and the transportability of software, and (v) the fabrication of devices by industry for general use. An operational protocol should be independent of any given control system and it must not be confused with a transmission protocol. As a first step, one defines an operational model of the device to be controlled. The model must represent a high-level description of the device as seen by the user. It will be characterized by a set of parameters and a set of rules. Although the particular requirements of specialists are not included in the operational protocol, allowances should be made for them. Emphasis will be placed on studies carried out on power converters and beam instrumentation. A general-purpose control message architecture is reported. (orig.).

  14. Operational protocols for controlling accelerator equipment

    Science.gov (United States)

    Bailey, R.; Baribaud, G.; Benincasa, G. P.; Burla, P.; Casalegno, L.; Coudert, G.; Gelato, G.; Kuhn, H. K.; Saban, R.; Spinks, A.

    1990-08-01

    The equipment used to operate an accelerator is varied. However, the different devices may be divided into a limited number of classes for which operational protocols can be defined. Operational protocols permit: (i) a uniform operation, (ii) a clear definition of responsibility between the various specialists, (iii) independent development of programs and use of the most appropriate technology, (iv) the change of hardware and the transportability of software, and (v) the fabrication of devices by industry for general use. An operational protocol should be independent of any given control system and it must not be confused with a transmission protocol. As a first step, one defines an operational model of the device to be controlled. The model must represent a high-level description of the device as seen by the user. It will be characterized by a set of parameters and a set of rules. Although the particular requirements of specialists are not included in the operational protocol, allowances should be made for them. Emphasis will be placed on studies carried out on power converters and beam instrumentation. A general-purpose control message architecture is reported.

  15. Automatic Validation of Protocol Narration

    DEFF Research Database (Denmark)

    Bodei, Chiara; Buchholtz, Mikael; Degano, Pierpablo;

    2003-01-01

    We perform a systematic expansion of protocol narrations into terms of a process algebra in order to make precise some of the detailed checks that need to be made in a protocol. We then apply static analysis technology to develop an automatic validation procedure for protocols. Finally, we...

  16. A New Primary Lazy Update Propagation Protocol for Replicated Databases

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    This paper proposes a new primary lazy update protocol, PTCS (Primary Transaction Commit Schedule). In the PTCS protocol, a serializable primary transaction schedule is generated firstly and then the secondary transactions are committed according to the serializable primary transaction schedule. PTCS protocol can guarantee serializability if the data copy graph contains no directed circles. It can also be extended to eliminate all requirements on the data copy graph. Compared to earlier works, PTCS protocol not only imposes a much weaker requirement on the data placement, but also avoids the deadlock caused by transaction waits and extra message overhead. The performance experiments show that the degradation of the performance caused by the replica management of the PTCS protocol is tolerable.

  17. Bayesian Authentication: Quantifying Security of the Hancke-Kuhn Protocol

    NARCIS (Netherlands)

    Pavlovic, Dusko; Meadows, Catherine; Mislove, M.; Selinger, P.

    2010-01-01

    As mobile devices pervade physical space, the familiar authentication patterns are becoming insufficient: besides entity authentication, many applications require, e.g., location authentication. Many interesting protocols have been proposed and implemented to provide such strengthened forms of authe

  18. SPECT/CT workflow and imaging protocols

    Energy Technology Data Exchange (ETDEWEB)

    Beckers, Catherine [University Hospital of Liege, Division of Nuclear Medicine and Oncological Imaging, Department of Medical Physics, Liege (Belgium); Hustinx, Roland [University Hospital of Liege, Division of Nuclear Medicine and Oncological Imaging, Department of Medical Physics, Liege (Belgium); Domaine Universitaire du Sart Tilman, Service de Medecine Nucleaire et Imagerie Oncologique, CHU de Liege, Liege (Belgium)

    2014-05-15

    Introducing a hybrid imaging method such as single photon emission computed tomography (SPECT)/CT greatly alters the routine in the nuclear medicine department. It requires designing new workflow processes and the revision of original scheduling process and imaging protocols. In addition, the imaging protocol should be adapted for each individual patient, so that performing CT is fully justified and the CT procedure is fully tailored to address the clinical issue. Such refinements often occur before the procedure is started but may be required at some intermediate stage of the procedure. Furthermore, SPECT/CT leads in many instances to a new partnership with the radiology department. This article presents practical advice and highlights the key clinical elements which need to be considered to help understand the workflow process of SPECT/CT and optimise imaging protocols. The workflow process using SPECT/CT is complex in particular because of its bimodal character, the large spectrum of stakeholders, the multiplicity of their activities at various time points and the need for real-time decision-making. With help from analytical tools developed for quality assessment, the workflow process using SPECT/CT may be separated into related, but independent steps, each with its specific human and material resources to use as inputs or outputs. This helps identify factors that could contribute to failure in routine clinical practice. At each step of the process, practical aspects to optimise imaging procedure and protocols are developed. A decision-making algorithm for justifying each CT indication as well as the appropriateness of each CT protocol is the cornerstone of routine clinical practice using SPECT/CT. In conclusion, implementing hybrid SPECT/CT imaging requires new ways of working. It is highly rewarding from a clinical perspective, but it also proves to be a daily challenge in terms of management. (orig.)

  19. FRENCH PROTOCOL CARDS

    CERN Multimedia

    Division des Ressources Humaines; Human Resources Division; Tel. 74683-79494

    2000-01-01

    Senior officials, holders of FRENCH PROTOCOL cards (blue cards) due to expire on 31.12.2000, are requested to return these cards and those of family members, for extension to: Bureau des cartes, Bât 33.1-009/1-015 Should the three spaces for authentication on the back of the card be full, please enclose two passport photographs for a new card. In the case of children aged 14 and over, an attestation of dependency and a school certificate should be returned with the card.

  20. FRENCH PROTOCOL CARDS

    CERN Multimedia

    Division du Personnel

    1999-01-01

    Senior officials, holders of FRENCH PROTOCOL cards (blue cards) due to expire on 31.12.1999, are requested to return these cards and those of family members, for extension to:Bureau des cartes, bâtiment 33.1-025Should the 3 spaces for authentication on the back of the card be full, please enclose 2 passport photographs for a new card.In the case of children aged 14 and over, an attestation of dependency and a school certificate should be returned with the card.Personnel DivisionTel. 79494/74683

  1. Power Saving MAC Protocols for WSNs and Optimization of S-MAC Protocol

    Directory of Open Access Journals (Sweden)

    Simarpreet Kaur

    2012-11-01

    Full Text Available Low power MAC protocols have received a lot of consideration in the last few years because of their influence on the lifetime of wireless sensor networks. Since, sensors typically operate on batteries, replacement of which is often difficult. A lot of work has been done to minimize the energy expenditure and prolong the sensor lifetime through energy efficient designs, across layers. Meanwhile, the sensor network should be able to maintain a certain throughput in order to fulfill the QoS requirements of the end user, and to ensure the constancy of the network. This paper introduces different types of MAC protocols used for WSNs and proposes S‐MAC, a Medium‐Access Control protocol designed for Wireless Sensor Networks. S‐MAC uses a few innovative techniques to reduce energy consumption and support selfconfiguration. A new protocol is suggested to improve the energy efficiency, latency and throughput of existing MAC protocol for WSNs. A modification of the protocol is then proposed to eliminate the need for some nodes to stay awake longer than the other nodes which improves the energy efficiency, latency and throughput and hence increases the life span of a wireless sensor network.

  2. Securing Zone Routing Protocol in Ad-Hoc Networks

    Directory of Open Access Journals (Sweden)

    Ibrahim S. I. Abuhaiba

    2012-09-01

    Full Text Available This paper is a contribution in the field of security analysis on mobile ad-hoc networks, and security requirements of applications. Limitations of the mobile nodes have been studied in order to design a secure routing protocol that thwarts different kinds of attacks. Our approach is based on the Zone Routing Protocol (ZRP; the most popular hybrid routing protocol. The importance of the proposed solution lies in the fact that it ensures security as needed by providing a comprehensive architecture of Secure Zone Routing Protocol (SZRP based on efficient key management, secure neighbor discovery, secure routing packets, detection of malicious nodes, and preventing these nodes from destroying the network. In order to fulfill these objectives, both efficient key management and secure neighbor mechanisms have been designed to be performed prior to the functioning of the protocol.To validate the proposed solution, we use the network simulator NS-2 to test the performance of secure protocol and compare it with the conventional zone routing protocol over different number of factors that affect the network. Our results evidently show that our secure version paragons the conventional protocol in the packet delivery ratio while it has a tolerable increase in the routing overhead and average delay. Also, security analysis proves in details that the proposed protocol is robust enough to thwart all classes of ad-hoc attacks.

  3. CANCER CHEMOPREVENTIVE ACTIVITIES OF S-3-1,A SYNTHETIC DERIVATIVE OF DANSHINONE

    Institute of Scientific and Technical Information of China (English)

    XIAO-GUANG CHEN; YAN LI; CHUN-HONG YAN; LIAN-NIANG LI; RUI HAN

    2001-01-01

    Salvia miltiorrhiza is a traditional Chinese medicine which has been well documented for its anti-cancer effects. Based on the structure of danshinone, one of the active compounds derived from Salvia miltiorrhiza, we synthesized a simplified phenolic analog, S-3-1, and tried to explore its possible actions in preventing the development of cancer. With the Ames test, S-3-1 was found to efficiently suppress the mutagenicity of benzo[a]pyrene. This result is consistent with the inhibitory effect of S-3-1 on the activation of benzo[α]pyrene by hepatic microsomal enzymes. Besides the anti-initiation effects, S-3-1 could significantly inhibit the croton oil induced increase of mouse skin epithermal ornithine decarboxylase activity. Moreover, S-3-1 quenched both superoxide and hydroxyl free radicals whereas it inhibited lipid peroxidation in the in vitro model. These results suggest that S-3-1 might act as anti-initiation and anti-promo tion agents through reversing the biochemical alterations induced by carcinogen during carcino genesis. Therefore, we further investigated the effects of S-3-1 on carcinogenesis. In vitro, S-3-1inhibited the benzo[a]pyrene-induced transformation of V79 Chinese hamster lung fibroblasts.At 10-40 mg/kg, S-3-1 was found to inhibit the development of DM BA/croton oil-induced skin papilloma in mice through decreasing the incidence of papilloma, prolonging the latent period of tumor occurrence and reducing tumor number per mouse in a dose-dependent manner. We concluded from this study that S-3-1 might be developed as a new chemopreventive drug.

  4. Dietary factors and cancer chemoprevention: An overview of obesity-related malignancies

    Directory of Open Access Journals (Sweden)

    Murthy N

    2009-01-01

    Full Text Available Obesity is a growing health problem in developed nations and in countries that are in the process of westernization like India. Obesity is linked with several health disorders such as hypertension and cardiovascular diseases, Type 2 diabetes, dyslipidemia and certain cancers. Currently, obesity-related malignancies, e.g., cancers of the breast, prostate and colon are the leading cancers in the industrialized societies. An increased amount of fat or adipose tissue in an overweight or obese person probably influences the development of cancer by releasing several hormone-like factors or adipokines. The majority of adipokines are pro-inflammatory, which promote pathological conditions like insulin resistance and cancer. On the other hand, many recent studies have shown that adiponectin, an anti-inflammatory adipokine, has anti-cancer and insulin-sensitizing effects. Adiponectin exerts its physiological functions chiefly by activation of AMP kinase via adiponectin receptors. Interestingly, several fruits and vegetables may contain adiponectin-like molecules or may increase the biosynthesis of adiponectin in our body. Studies on adiponectin analogues or adiponectin receptor agonists are a promising area of cancer chemoprevention research. In general, fruits and vegetables contain various dietary substances such as vitamins, minerals (like calcium and selenium, fiber and phytochemicals or phenolic compounds (like flavonoids and vanilloids, which may act as anti-cancer agents. Similarly, several dietary constituents including phytochemicals may have anti-obesity effects. Consumption of such dietary compounds along with caloric restriction and physical activity may be helpful in preventing obesity-related cancers. For this review article, we searched PubMed primarily to get the relevant literature.

  5. Potential chemoprevention of diethylnitrosamine-induced hepatocarcinogenesis in rats: myrrh (Commiphora molmol) vs. turmeric (Curcuma longa).

    Science.gov (United States)

    El-Shahat, Mohamed; El-Abd, Sabah; Alkafafy, Mohamed; El-Khatib, Gamal

    2012-09-01

    The aim of the present study was to assess the potential chemopreventive effects of myrrh (Commiphora molmol) vs. turmeric (Curcuma longa) in hepatocarcinogenic rats induced by a single intraperitoneal injection of diethylnitrosamine (DENA) (200 mg/kg body weight). Ninety male Wistar rats used in this study were randomly divided into six equal groups (n=15). Group 1 rats served as negative controls; group 2 received a single i.p. injection of DENA and served as positive controls. Rats in both groups were fed on basal diet. Group 3 rats were fed a diet containing 5% turmeric, whereas group 4 rats were fed a diet containing 2% myrrh. Rats in groups 5 and 6 received a single i.p. injection of DENA and were fed diets containing 5% turmeric and 2% myrrh, respectively. The study demonstrated that DENA caused a significant increase in serum indices of liver enzymes and also severe histological and immunohistochemical changes in hepatic tissues. These included disorganized hepatic parenchyma, appearance of pseudoacinar and trabecular arrays of hepatocytes and alterations in CD10-immunoreactivity. Dietary supplementation of turmeric relatively improved the biochemical parameters to values approximating those of the negative controls and delayed the initiation of carcinogenesis. In contrast, myrrh did not improve the biochemical parameters or delay the hepatocarcinogenesis. Both turmeric and myrrh induced significant biochemical and histological changes in non-treated rats. In conclusion, DENA significantly changes the biological enzymatic activities in serum and the integrity of hepatic tissues. Phytochemicals with potential hepatoprotective effects must be applied cautiously owing to their potential hepatotoxicity.

  6. Folic acid supplementation inhibits recurrence of colorectal adenomas: A randomized chemoprevention trial

    Institute of Scientific and Technical Information of China (English)

    Richard Jaszewski; Adhip PN Majumdar; Sabeena Misra; Martin Tobi; Nadeem Ullah; Jo Ann Naumoff; Omer Kucuk; Edi Levi; Bradley N Axelrod; Bhaumik B Patel

    2008-01-01

    AIM: To determine whether folic acid supplementation will reduce the recurrence of colorectal adenomas,the precursors of colorectal cancer, we performed a double-blind placebo-controlled trial in patients with adenomatous polyps.METHODS: In the current double-blind, placebo-controlled trial at this VA Medical Center, patients with colorectal adenomas were randomly assigned to receive either a daily 5 mg dose of folic acid or a matched identical placebo for 3 years. All polyps were removed at baseline colonoscopy and each patient had a follow up colonoscopy at 3 years. The primary endpoint was a reduction in the number of recurrent adenomas at 3 years.RESULTS: Of 137 subjects, who were eligible after confirmation of polyp histology and run-in period to conform compliance, 94 completed the study; 49 in folic acid group and 45 in placebo group. Recurrence of adenomas at 3-year was compared between the two groups. The mean number of recurrent polyps at 3-year was 0.36 (SD, 0.69) for folic acid treated patients compared to 0.82 (SD, 1.17) for placebo treated subjects, resulting in a 3-fold increase in polyp recurrence in the placebo group. Patients below 70 years of age and those with left-sided colonic adenomas or advanced adenomas responded better to folic acid supplementation.CONCLUSION: High dose folic acid supplementation is associated with a significant reduction in the recurrence of colonic adenomas suggesting that folic acid may be an effective chemopreventive agent for colorectal neoplasia.

  7. Chemoprevention of human actinic keratoses by topical DL-alpha-tocopherol.

    Science.gov (United States)

    Foote, Janet A; Ranger-Moore, James R; Einspahr, Janine G; Saboda, Kathylynn; Kenyon, Jaime; Warneke, James; Miller, Richard C; Goldman, Rayna; Xu, Min-Jian; Roe, Denise J; Alberts, David S

    2009-04-01

    Prior research shows that topical application of free, nonfatty acid-conjugated vitamin E (DL-alpha-tocopherol) prevents skin cancer in mice, as well as immunosuppression induced by UVB radiation. This study investigated the chemopreventive potential of DL-alpha-tocopherol in humans through monitoring surrogate end point biomarkers in sun-damaged skin. Contralateral arms of healthy human volunteers with actinic keratoses (AK) were randomly assigned to receive either 12.5% DL-alpha-tocopherol or placebo in a crème base for 6 months. Changes in number of AKs, levels of p53 protein expression, proliferating cell nuclear antigen, and polyamines were assessed along with skin and systemic vitamin E levels. Following treatment, plasma concentration levels of DL-alpha-tocopherol were unchanged, but skin levels were highly elevated (P cell nuclear antigen did not change significantly, whereas number of AKs declined insignificantly in both placebo and treatment arms. Regression models showed significant decreases in putrescine, spermidine, spermine, and total polyamine concentrations following treatment. Topically applied DL-alpha-tocopherol was substantially absorbed in skin, but the 6-month application did not significantly reduce numbers of preexisting AKs on moderately to severely sun-damaged forearms. Increases in polyamine synthesis are expected during tumor initiation and promotion; conversely, the significant reductions in polyamine levels resulting from the topical DL-alpha-tocopherol application are consistent with reductions in tumorigenesis potential. Topical tocopherol did not normalize established sun-induced lesions, but DL-alpha-tocopherol-induced reductions in polyamine metabolism are consistent with the inhibition of skin squamous cell carcinogenesis as seen in previous human trials and animal models.

  8. Chemoprevention of prostate cancer by d,l-sulforaphane is augmented by pharmacological inhibition of autophagy.

    Science.gov (United States)

    Vyas, Avani R; Hahm, Eun-Ryeong; Arlotti, Julie A; Watkins, Simon; Stolz, Donna Beer; Desai, Dhimant; Amin, Shantu; Singh, Shivendra V

    2013-10-01

    There is a preclinical evidence that the oral administration of d,l-sulforaphane (SFN) can decrease the incidence or burden of early-stage prostate cancer [prostatic intraepithelial neoplasia (PIN)] and well-differentiated cancer (WDC) but not late-stage poorly differentiated cancer (PDC). Because SFN treatment induces cytoprotective autophagy in cultured human prostate cancer cells, the present study tested the hypothesis that chemopreventive efficacy of SFN could be augmented by the pharmacologic inhibition of autophagy using chloroquine (CQ). Incidence of PDC characterized by prostate weight of more than 1 g was significantly lower in the SFN + CQ group than in control (P = 0.004), CQ group (P = 0.026), or SFN group (P = 0.002 by Fisher exact test). Average size of the metastatic lymph node was lower by about 42% in the SFN + CQ group than in control (P = 0.043 by Wilcoxon test). On the other hand, the SFN + CQ combination was not superior to SFN alone with respect to inhibition of incidence or burden of microscopic PIN or WDC. SFN treatment caused in vivo autophagy as evidenced by transmission electron microscopy. Mechanistic studies showed that prevention of prostate cancer and metastasis by the SFN + CQ combination was associated with decreased cell proliferation, increased apoptosis, alterations in protein levels of autophagy regulators Atg5 and phospho-mTOR, and suppression of biochemical features of epithelial-mesenchymal transition. Plasma proteomics identified protein expression signature that may serve as biomarker of SFN + CQ exposure/response. This study offers a novel combination regimen for future clinical investigations for prevention of prostate cancer in humans.

  9. Chemopreventive Effects of RXR-Selective Rexinoid Bexarotene on Intestinal Neoplasia of ApcMin/+ Mice

    Directory of Open Access Journals (Sweden)

    Naveena B. Janakiram

    2012-02-01

    Full Text Available Retinoid X receptor (RXR has been implicated in several neoplastic diseases. Previously, we have shown that RXR-α is downregulated in human and rodent colonic tumors, suggesting a potential target for colon cancer prevention (http://www.cancer.org/Cancer/ColonandRectumCancer/DetailedGuide/colorectal-cancer-key-statistics. Experiments were designed to assess the chemopreventive efficacy of the selective RXR agonist bexarotene for the suppression of intestinal tumorigenesis in ApcMin/+ mice. Before the efficacy studies, we determined that the maximal tolerated dose in C57BL/6J mice was less than 400 ppm. For the efficacy study, 6-week-old male and female C57BL/6J-ApcMin/+ mice (nine mice per group were fed diets containing 0, 30, and 60 ppm of bexarotene or 200 ppm of bexarotene for 80 days before intestinal tumors were evaluated. Dietary administration of 30 and 60 ppm of bexarotene suppressed the intestinal polyp formation by 38% (P < .015 and 60% (P < .0001 in males, respectively, and by 8.5% and 37% (P < .007 in females, respectively. Also, significant inhibition (50%–100% of colonic tumor formation was observed in both male and female mice with bexarotene treatment. Administration of 200 ppm of bexarotene showed significant suppression of tumor formation (66%, P < .0001; however, it had significant toxicity. Intestinal tumors of bexarotene-fed mice showed significantly reduced expression of proliferating cell nuclear antigen (60%, P < .0001, cyclin D1, and cyclooxygenase 2 and increased RXR-α messenger RNA and uptake of oleate (34%, P < .01. Also, bexarotene-fed mice showed dose-dependent suppression of serum triglycerides (25%–72%, P < .0001 and inflammatory cytokines.

  10. Analysis of Security Protocols in Embedded Systems

    DEFF Research Database (Denmark)

    Bruni, Alessandro

    .e., protecting the system from the external world). With increased connectivity of these systems to external networks the attack surface has grown, and consequently there is a need for securing the system from external attacks. Introducing security protocols in safety critical systems requires careful......Embedded real-time systems have been adopted in a wide range of safety-critical applications—including automotive, avionics, and train control systems—where the focus has long been on safety (i.e., protecting the external world from the potential damage caused by the system) rather than security (i...... considerations on the available resources, especially in meeting real-time and resource constraints, as well as cost and reliability requirements. For this reason many proposed security protocols in this domain have peculiar features, not present in traditional security literature. In this thesis we tackle...

  11. Chemoprevention of HBV-related hepatocellular carcinoma by the combined product of resveratrol and silymarin in transgenic mice

    Directory of Open Access Journals (Sweden)

    Wen-Chuan Hsieh

    2013-09-01

    Full Text Available ABSTRACTBackground: Patients with chronic hepatitis B virus (HBV infection are at a high risk to develop hepatocellular carcinoma (HCC. Recently, metabolic syndrome has been found to carry a risk for HCC development. Considering the limitation of chemotherapeutic drugs for HCCs, the development of chemopreventive agents for high risk chronic HBV carriers is urgently demanded. In this study, we used combined silymarin and resveratrol extract which have been shown to exhibit biologic effects on activating peroxisome proliferator activated receptors (PPAR and inhibiting mTOR signaling in a transgenic mice model harboring HBV viral oncoproteins.Methods: The transgenic mice model harboring HBx and pre-S2 mutant constructs which develop HCC was adopted. First, we in vitro tested the ideal combination dosages of the silymarin and resveratrol product, and then we fed the natural product to the transgenic mice.The chemopreventive effects on preventing the development of HCC were evaluated.Results: MTT assay showed an enhanced effect of the combined silymarin and resveratrol product on the reduction of cell proliferation in two hepatoma cell lines, Huh-7 and Hep G2. In vitro reporter assay and Western blot analyses revealed that the combined product couldactivate PPAR/PGC-1 signaling and inhibit mTOR expression. In vivo, the combined products could significantly ameliorate fatty liver and reduce HCCs in transgenic miceharboring HBV oncoproteins.Conclusions: The combined silymarin and resveratrol product exhibits a synergistic effect on the reduction of HCC development in transgenic mice model and may represent a potential agent for the prevention of HCC in high risk chronic HBV carriers.Key words: HBV, HCC, Transgenic mice, Chemoprevention

  12. The role of chemoprevention by selective cyclooxygenase-2 inhibitors in colorectal cancer patients - a population-based study

    Directory of Open Access Journals (Sweden)

    Yang Yi-Hsin

    2012-12-01

    Full Text Available Abstract Background There are limited population-based studies focusing on the chemopreventive effects of selective cyclooxygenase-2 (COX-2 inhibitors against colorectal cancer. The purpose of this study is to assess the trends and dose–response effects of various medication possession ratios (MPR of selective COX-2 inhibitor used for chemoprevention of colorectal cancer. Methods A population-based case–control study was conducted using the Taiwan Health Insurance Research Database (NHIRD. The study comprised 21,460 colorectal cancer patients and 79,331 controls. The conditional logistic regression was applied to estimate the odds ratios (ORs for COX-2 inhibitors used for several durations (5 years, 3 years, 1 year, 6 months and 3 months prior to the index date. Results In patients receiving selective COX-2 inhibitors, the OR was 0.51 (95% CI=0.29~0.90, p=0.021 for an estimated 5-year period in developing colorectal cancer. ORs showing significant protection effects were found in 10% of MPRs for 5-year, 3-year, and 1-year usage. Risk reduction against colorectal cancer by selective COX-2 inhibitors was observed as early as 6 months after usage. Conclusion Our results indicate that selective COX-2 inhibitors may reduce the development of colorectal cancer by at least 10% based on the MPRs evaluated. Given the limited number of clinical reports from general populations, our results add to the knowledge of chemopreventive effects of selective COX-2 inhibitors against cancer in individuals at no increased risk of colorectal cancer.

  13. Statins dose-dependently exert a chemopreventive effect against lung cancer in COPD patients: a population-based cohort study

    Science.gov (United States)

    Hsu, Yi-Ping; Hao, Wen-Rui; Kao, Pai-Feng; Sung, Li-Chin; Chen, Chun-Chao; Wu, Szu-Yuan

    2016-01-01

    Purpose Chronic obstructive pulmonary disease (COPD) is associated with increased lung cancer risk. We evaluated the association of statin use with lung cancer risk in COPD patients and identified which statins possess the highest chemopreventive potential. Results After adjustment for age, sex, CCI, diabetes, hypertension, dyslipidemia, urbanization level, and monthly income according to propensity scores, lung cancer risk in the statin users was lower than that in the statin nonusers (adjusted hazard ratio [aHR] = 0.37). Of the individual statins, lovastatin and fluvastatin did not reduce lung cancer risk significantly. By contrast, lung cancer risk in patients using rosuvastatin, simvastatin, atorvastatin, and pravastatin was significantly lower than that in statin nonusers (aHRs = 0.41, 0.44, 0.52, and 0.58, respectively). Statins dose-dependently reduced lung cancer risk in all subgroups and the main model with additional covariates (nonstatin drug use). MATERIALS AND METHODS The study cohort comprised all patients diagnosed with COPD at health care facilities in Taiwan (n = 116,017) between January 1, 2001 and December 31, 2012. Our final study cohort comprised 43,802 COPD patients: 10,086 used statins, whereas 33,716 did not. Patients were followed up to assess lung cancer risk or protective factors. In addition, we also considered demographic characteristics, namely age, sex, comorbidities (diabetes, hypertension, dyslipidemia, and Charlson comorbidity index [CCI]), urbanization level, monthly income, and nonstatin drug use. The index date of statin use was the COPD confirmation date. To examine the dose–response relationship, we categorized statin use into four groups in each cohort: 365 cumulative defined daily doses (cDDDs). Patients receiving Statins dose-dependently exert a significant chemopreventive effect against lung cancer in COPD patients. Rosuvastatin, simvastatin, and atorvastatin exhibited the highest chemopreventive potential. PMID:27517752

  14. A novel chemopreventive mechanism for a traditional medicine: East Indian sandalwood oil induces autophagy and cell death in proliferating keratinocytes.

    Science.gov (United States)

    Dickinson, Sally E; Olson, Erik R; Levenson, Corey; Janda, Jaroslav; Rusche, Jadrian J; Alberts, David S; Bowden, G Timothy

    2014-09-15

    One of the primary components of the East Indian sandalwood oil (EISO) is α-santalol, a molecule that has been investigated for its potential use as a chemopreventive agent in skin cancer. Although there is some evidence that α-santalol could be an effective chemopreventive agent, to date, purified EISO has not been extensively investigated even though it is widely used in cultures around the world for its health benefits as well as for its fragrance and as a cosmetic. In the current study, we show for the first time that EISO-treatment of HaCaT keratinocytes results in a blockade of cell cycle progression as well as a concentration-dependent inhibition of UV-induced AP-1 activity, two major cellular effects known to drive skin carcinogenesis. Unlike many chemopreventive agents, these effects were not mediated through an inhibition of signaling upstream of AP-1, as EISO treatment did not inhibit UV-induced Akt or MAPK activity. Low concentrations of EISO were found to induce HaCaT cell death, although not through apoptosis as annexin V and PARP cleavage were not found to increase with EISO treatment. However, plasma membrane integrity was severely compromised in EISO-treated cells, which may have led to cleavage of LC3 and the induction of autophagy. These effects were more pronounced in cells stimulated to proliferate with bovine pituitary extract and EGF prior to receiving EISO. Together, these effects suggest that EISO may exert beneficial effects upon skin, reducing the likelihood of promotion of pre-cancerous cells to actinic keratosis (AK) and skin cancer.

  15. Chemoprevention of DMH-induced rat colon carcinoma initiation by combination administration of piroxicam and C-phycocyanin.

    Science.gov (United States)

    Saini, Manpreet Kaur; Vaiphei, Kim; Sanyal, Sankar Nath

    2012-02-01

    Cancer research illustrated that combinatorial studies can provide significant improvement in safety and effectiveness over the monotherapy regimens. A combination of two drugs may restrain precancerous colon polyps, opening a new possible opportunity for chemoprevention of colon cancer. In this context, chemopreventive efficacy of a combination regimen of C-phycocyanin, a biliprotein present in Spirulina platensis, a cyanobacterium, which is a selective cycloxygenase-2 (COX-2) inhibitor and piroxicam, a traditional non-steroidal anti-inflammatory drug was considered in 1,2 dimethylhyadrazine (DMH)-induced colon carcinogenesis in rats. Western blotting, immunohistochemistry, DNA fragmentation, fluorescent staining, PGE(2) enzyme immunoassay, and carrageenan-induced paw edema test were performed along with morphological and histological analysis. DMH treatment showed a rich presence of preneoplastic lesions such as multiple plaque lesions, aberrant crypt foci, and well-characterized dysplasia. These features were reduced with piroxicam and C-phycocyanin administration. The number of apoptotic cells was featured prominently in all the groups compared with DMH. DMH treatment revealed intact high molecular weight genomic DNA with no signs of laddering/DNA fragmentation while it was noticeable significantly in control and DMH + piroxicam + C-phycocyanin. DMH group showed highest COX-2 expression and PGE(2) level in comparison with other groups. Doses of piroxicam and C-phycocyanin used in the present study were established at an anti-inflammatory range. A combination regimen of piroxicam and C-phycocyanin, rather than individually has the much greater potential for reduction of DMH-induced colon cancer development and COX-2 being the prime possible target in such chemoprevention.

  16. Safety and chemopreventive effect of Polyphenon E in preventing early and metastatic progression of prostate cancer in TRAMP mice.

    Science.gov (United States)

    Kim, Seung Joon; Amankwah, Ernest; Connors, Shahnjayla; Park, Hyun Y; Rincon, Maria; Cornnell, Heather; Chornokur, Ganna; Hashim, Arig Ibrahim; Choi, Junsung; Tsai, Ya-Yu; Engelman, Robert W; Kumar, Nagi; Park, Jong Y

    2014-04-01

    Prostate cancer treatment is often accompanied by untoward side effects. Therefore, chemoprevention to reduce the risk and inhibit the progression of prostate cancer may be an effective approach to reducing disease burden. We investigated the safety and efficacy of Polyphenon E, a green tea extract, in reducing the progression of prostate cancer in transgenic adenocarcinoma of the mouse prostate (TRAMP) mice. A total of 119 male TRAMP and 119 C57BL/6J mice were treated orally with one of 3 doses of Polyphenon E (200, 500, and 1,000 mg/kg/day) in drinking water ad libitum replicating human achievable doses. Baseline assessments were performed before treatments. Safety and efficacy assessments during treatments were performed when mice were 12, 22, and 32 weeks old. The number and size of tumors in treated TRAMP mice were significantly decreased compared with untreated animals. In untreated 32 weeks old TRAMP mice, prostate carcinoma metastasis to distant sites was observed in 100% of mice (8/8), compared with 13% of mice (2/16) treated with high-dose Polyphenon E during the same period. Furthermore, Polyphenon E treatment significantly inhibited metastasis in TRAMP mice in a dose-dependent manner (P = 0.0003). Long-term (32 weeks) treatment with Polyphenon E was safe and well tolerated with no evidence of toxicity in C57BL/6J mice. Polyphenon E is an effective chemopreventive agent in preventing the progression of prostate cancer to metastasis in TRAMP mice. Polyphenon E showed no toxicity in these mouse models. Our findings provide additional evidence for the safety and chemopreventive effect of Polyphenon E in preventing metastatic progression of prostate cancer.

  17. Bounding the per-protocol effect in randomized trials: An application to colorectal cancer screening

    NARCIS (Netherlands)

    S.A. Swanson (Sonja); Holme (Øyvind); M. Løberg (Magnus); M. Kalager (Mette); M. Bretthauer (Michael); G. Hoff (G.); E. Aas (Eline); M.A. Hernán (M.)

    2015-01-01

    textabstractBackground: The per-protocol effect is the effect that would have been observed in a randomized trial had everybody followed the protocol. Though obtaining a valid point estimate for the per-protocol effect requires assumptions that are unverifiable and often implausible, lower and upper

  18. Mechanisms of Nrf2/Keap1-Dependent Phase II Cytoprotective and Detoxifying Gene Expression and Potential Cellular Targets of Chemopreventive Isothiocyanates

    Directory of Open Access Journals (Sweden)

    Biswa Nath Das

    2013-01-01

    Full Text Available Isothiocyanates (ITCs are abundantly found in cruciferous vegetables. Epidemiological studies suggest that chronic consumption of cruciferous vegetables can lower the overall risk of cancer. Natural ITCs are key chemopreventive ingredients of cruciferous vegetables, and one of the prime chemopreventive mechanisms of natural isothiocyanates is the induction of Nrf2/ARE-dependent gene expression that plays a critical role in cellular defense against electrophiles and reactive oxygen species. In the present review, we first discuss the underlying mechanisms how natural ITCs affect the intracellular signaling kinase cascades to regulate the Keap1/Nrf2 activities, thereby inducing phase II cytoprotective and detoxifying enzymes. We also discuss the potential cellular protein targets to which natural ITCs are directly conjugated and how these events aid in the chemopreventive effects of natural ITCs. Finally, we discuss the posttranslational modifications of Keap1 and nucleocytoplasmic trafficking of Nrf2 in response to electrophiles and oxidants.

  19. QAODV: Improved Security Routing Protocol of AODV

    OpenAIRE

    Ruihui Mu; Wuqiang Zhang

    2013-01-01

    Network control system (NCS) has higher requirements on QoS index of the network, but MANET can hardly meet the demands of control systems because of its own characteristics. The paper improves AODV and proposes AODV routing protocol QAODV with certain QoS security in combination with NCS and MANET, and expounds routing detection, routing register and routing maintenance. Simulation results show that end-to-end delay and packet loss of QAODV reduces evidently compared with AODV, and the proto...

  20. Formal analysis and design of multi-party fair exchange protocols

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Based on the origin of message items and channel combination between transacting parties, and events and relations among events, this paper presents a concise, precise, and hierarchical model for general fair exchange protocols, formally specifies various security requirements which are able to reflect inherent requirements for fair exchange protocols more rigorously, and partition these security requirements with fine granularity. This work helps analyze, debug, and design multi-party fair exchange protocols more effectively and elaborately.

  1. Stream Control Transmission Protocol Steganography

    CERN Document Server

    Fraczek, Wojciech; Szczypiorski, Krzysztof

    2010-01-01

    Stream Control Transmission Protocol (SCTP) is a new transport layer protocol that is due to replace TCP (Transmission Control Protocol) and UDP (User Datagram Protocol) protocols in future IP networks. Currently, it is implemented in such operating systems like BSD, Linux, HP-UX or Sun Solaris. It is also supported in Cisco network devices operating system (Cisco IOS) and may be used in Windows. This paper describes potential steganographic methods that may be applied to SCTP and may pose a threat to network security. Proposed methods utilize new, characteristic SCTP features like multi-homing and multistreaming. Identified new threats and suggested countermeasures may be used as a supplement to RFC 5062, which describes security attacks in SCTP protocol and can induce further standard modifications.

  2. Protocols for Scholarly Communication

    CERN Document Server

    Pepe, Alberto; Pepe, Alberto; Yeomans, Joanne

    2007-01-01

    CERN, the European Organization for Nuclear Research, has operated an institutional preprint repository for more than 10 years. The repository contains over 850,000 records of which more than 450,000 are full-text OA preprints, mostly in the field of particle physics, and it is integrated with the library's holdings of books, conference proceedings, journals and other grey literature. In order to encourage effective propagation and open access to scholarly material, CERN is implementing a range of innovative library services into its document repository: automatic keywording, reference extraction, collaborative management tools and bibliometric tools. Some of these services, such as user reviewing and automatic metadata extraction, could make up an interesting testbed for future publishing solutions and certainly provide an exciting environment for e-science possibilities. The future protocol for scientific communication should naturally guide authors towards OA publication and CERN wants to help reach a full...

  3. A PROGRAMMED LABOUR - PROTOCOL

    Directory of Open Access Journals (Sweden)

    Savita

    2014-12-01

    Full Text Available A Prospective randomized Clinical study of outcome of labour following. “A Programmed labour. Protocol” was done at Department of OBG, MRMC Gulbarga. The Protocol was aimed with dual. Objective of Providing Pain relief during labour and teaching the goal of safe motherhood by optimizing objective outcome. AIMS AND OBJECTIVES: Shortening of duration of labour. Effect of labour analgesia. Monitoring of the events during labour. Lowering the incidence of operative deliveries. METHODS: 100 cases primi pregnant women admitted in labour room are randomly selected. It is designed to apply to low risk primi parous, singleton cephalic presentation without evidence of CPD and spontaneous onset of labour. RESULTS: Shortened duration of all the stages of Labour, especially significant reduction in duration of active phase of labour. CONCLUSION: The programmed labour is simple easy and effective method for painless and safe delivery.

  4. Static Validation of Security Protocols

    DEFF Research Database (Denmark)

    Bodei, Chiara; Buchholtz, Mikael; Degano, P.;

    2005-01-01

    We methodically expand protocol narrations into terms of a process algebra in order to specify some of the checks that need to be made in a protocol. We then apply static analysis technology to develop an automatic validation procedure for protocols. Finally, we demonstrate that these techniques ...... suffice to identify several authentication flaws in symmetric and asymmetric key protocols such as Needham-Schroeder symmetric key, Otway-Rees, Yahalom, Andrew secure RPC, Needham-Schroeder asymmetric key, and Beller-Chang-Yacobi MSR...

  5. Mars Sample Handling Protocol Workshop Series: Workshop 4

    Science.gov (United States)

    Race Margaret S. (Editor); DeVincenzi, Donald L. (Editor); Rummel, John D. (Editor); Acevedo, Sara E. (Editor)

    2001-01-01

    In preparation for missions to Mars that will involve the return of samples to Earth, it will be necessary to prepare for the receiving, handling, testing, distributing, and archiving of martian materials here on Earth. Previous groups and committees have studied selected aspects of sample return activities, but specific detailed protocols for the handling and testing of returned samples must still be developed. To further refine the requirements for sample hazard testing and to develop the criteria for subsequent release of sample materials from quarantine, the NASA Planetary Protection Officer convened a series of workshops in 2000-2001. The overall objective of the Workshop Series was to produce a Draft Protocol by which returned martian sample materials can be assessed for biological hazards and examined for evidence of life (extant or extinct) while safeguarding the purity of the samples from possible terrestrial contamination. This report also provides a record of the proceedings of Workshop 4, the final Workshop of the Series, which was held in Arlington, Virginia, June 5-7, 2001. During Workshop 4, the sub-groups were provided with a draft of the protocol compiled in May 2001 from the work done at prior Workshops in the Series. Then eight sub-groups were formed to discuss the following assigned topics: Review and Assess the Draft Protocol for Physical/Chemical Testing Review and Assess the Draft Protocol for Life Detection Testing Review and Assess the Draft Protocol for Biohazard Testing Environmental and Health/Monitoring and Safety Issues Requirements of the Draft Protocol for Facilities and Equipment Contingency Planning for Different Outcomes of the Draft Protocol Personnel Management Considerations in Implementation of the Draft Protocol Draft Protocol Implementation Process and Update Concepts This report provides the first complete presentation of the Draft Protocol for Mars Sample Handling to meet planetary protection needs. This Draft Protocol

  6. SECURED ELECTRONIC VOTING PROTOCOL USING HYBRID CRYPTOSYSTEM

    Directory of Open Access Journals (Sweden)

    KALAICHELVI V

    2013-04-01

    Full Text Available Electronic Voting play a really vital role in the democracy of our life. In this paper, we propose an electronic voting protocol. Our scheme does not require a special voting channel and communication can occur entirely over the current Internet. This method integrates the Internet convenience and cryptology. In the existing protocol the Tallier has to wait until the decryption key is received from the voter. So it will consume lot of time. But, the proposed protocol is based on the hybrid cryptosystem. In this, the ballot is encrypted using faster secret key algorithm and the digital envelope is encrypted using Tallier’s public key. So, the Tallier will decrypt the digital envelope using his own private key to get the secret key and then the encrypted ballot is decrypted using that secret key. So, comparatively the proposed protocol consumes less time. This paper also analyzes the various security issues involved in an electronic voting like security, privacy, authentication, anonymous, uniqueness, accuracy, fairness, efficiency and uncoercibility.

  7. The Kyoto protocol in a global perspective

    Directory of Open Access Journals (Sweden)

    Tjaša Redek

    2009-11-01

    Full Text Available The global climate has changed notably since the beginning of the Industrial Revolution. Atmospheric concentrations of greenhouse gasses (GHG have increased dramatically followed by an increase in global average temperature. In order to avoid negative potential outcomes of global warming, countries have adopted the United Nations Framework Convention on Climate Change that has so far been ratified by 192 countries. In 1997 the Kyoto Protocol, a binding GHG reduction plan, was adopted and entered into force in 2005. But several countries, including the USA, have had doubts about the potential negative consequences of the planned 5% global joint reduction of GHG. However, studies generally show that on a macroeconomic level: (1 welfare loss in terms of GDP and lost growth in EU is low; (2 it differs among economies; and (3 permit trading and permit price (in either global or regional markets is highly correlated with the welfare loss. The main objective of the paper is to describe the attitudes and responses to the Kyoto Protocol from a global perspective. The paper has three objectives. First, to provide an overview of global greenhouse gas emissions and the big drivers behind these emissions. Second, to present where different countries, both developed and less developed countries, such as India, China and the countries of South-east Europe currently stand as regards their efforts to achieve the Kyoto Protocol requirements. Third, to analyse the responses and attitudes to the Kyoto Protocol from a country development perspective.

  8. SECURITY ENHANCEMENT FOR 3- PEKE PROTOCOL USING PARALLEL MESSAGE TRANSMISSION TECHNIQUE

    OpenAIRE

    2012-01-01

    It is easy to choose and memorize simple and meaningful vocabulary as secret passwords, but it is very hard to meet the requirement of security and efficiency. Hence chang and chang proposed a novel three party encrypted key exchange protocol without using the server’s public keys. The key exchange protocol has achieved great attention due to its simplicity and efficiency. It was claimed that the protocol was practically secure and efficient. On the other hand, the protocol resists all types ...

  9. Lightweight Mutual Authentication Protocol for Low Cost RFID Tags

    CERN Document Server

    Ahmed, Eslam Gamal; Hashem, Mohamed; 10.5121/ijnsa.2010.2203

    2010-01-01

    Radio Frequency Identification (RFID) technology one of the most promising technologies in the field of ubiquitous computing. Indeed, RFID technology may well replace barcode technology. Although it offers many advantages over other identification systems, there are also associated security risks that are not easy to be addressed. When designing a real lightweight authentication protocol for low cost RFID tags, a number of challenges arise due to the extremely limited computational, storage and communication abilities of Low-cost RFID tags. This paper proposes a real mutual authentication protocol for low cost RFID tags. The proposed protocol prevents passive attacks as active attacks are discounted when designing a protocol to meet the requirements of low cost RFID tags. However the implementation of the protocol meets the limited abilities of low cost RFID tags.

  10. Design of Intelligent Cross-Layer Routing Protocols for Airborne Wireless Networks Under Dynamic Spectrum Access Paradigm

    Science.gov (United States)

    2011-05-01

    routing protocols require link layer detection and hello message to maintain multiple routes . Various single and multipath protocols , like AODV ... protocols (e.g., AODV , DSR, Optimized Link State Routing (OLSR) etc.) with and without link layer detection. The protocols with link layer detection...Reactive protocols like AODV tend to reduce the control traffic messages overhead at the cost of increased latency in finding new routes . AODV has a

  11. CREATION OF THE MODEL ADDITIONAL PROTOCOL

    Energy Technology Data Exchange (ETDEWEB)

    Houck, F.; Rosenthal, M.; Wulf, N.

    2010-05-25

    In 1991, the international nuclear nonproliferation community was dismayed to discover that the implementation of safeguards by the International Atomic Energy Agency (IAEA) under its NPT INFCIRC/153 safeguards agreement with Iraq had failed to detect Iraq's nuclear weapon program. It was now clear that ensuring that states were fulfilling their obligations under the NPT would require not just detecting diversion but also the ability to detect undeclared materials and activities. To achieve this, the IAEA initiated what would turn out to be a five-year effort to reappraise the NPT safeguards system. The effort engaged the IAEA and its Member States and led to agreement in 1997 on a new safeguards agreement, the Model Protocol Additional to the Agreement(s) between States and the International Atomic Energy Agency for the Application of Safeguards. The Model Protocol makes explicit that one IAEA goal is to provide assurance of the absence of undeclared nuclear material and activities. The Model Protocol requires an expanded declaration that identifies a State's nuclear potential, empowers the IAEA to raise questions about the correctness and completeness of the State's declaration, and, if needed, allows IAEA access to locations. The information required and the locations available for access are much broader than those provided for under INFCIRC/153. The negotiation was completed in quite a short time because it started with a relatively complete draft of an agreement prepared by the IAEA Secretariat. This paper describes how the Model Protocol was constructed and reviews key decisions that were made both during the five-year period and in the actual negotiation.

  12. High speed transport protocols: An attempt to find the best solution

    Science.gov (United States)

    Lazaris, Konstantinos A.

    1994-03-01

    The development and advances in fiber optic technology are leading to major changes in modern telecommunications systems. In short, the transmission of data through optical fiber has become so fast that the computers which the fibers connect have become a bottleneck. The transport layer protocol, which is the software interface between the network and the computer, is one of the most important sources of this bottleneck. The purpose of this thesis is to investigate several 'high-speed' transport protocols, evaluate them, and attempt to determine which transport protocol or combination of transport protocols is optimal for high speed networks of the future. The approach is to first study the requirements of transport protocols for high speed networks. Then the properties of several specific transport protocols are studied with these requirements in mind. A detailed analysis of the strengths and shortcomings of Transmission Control Protocol/Internet Protocol (TCP/IP), Xpress Transfer Protocol (XTP), and SNR are presented. TCP/IP, which is in wide use today, was designed when transmission rates were much slower and error rates were much higher than today. XTP and SNR are two new experimental transport layer protocols which have been recently designed with high speed networks in mind. The primary contribution of this thesis is an evaluation of the requirements of future transport protocols. In short, TCP/IP in its present form is simply not adequate; it must change and adapt, or be replaced by a new transport protocol like XTP or SNR.

  13. Impact of Obesity on Tamoxifen Chemoprevention in a Model of Ductal Carcinoma in Situ

    Science.gov (United States)

    2012-10-01

    drug delivery, surgeries, necropsy, cardiac puncture), and statistical analysis Postdoctoral Fellow- NeuroOncology Department of Pathology...1998 University of Texas, Arlington (Dr. Frederick M. MacDonnell) • Developed the protocol to synthesize a chiral ruthenium dimmer, then connect the

  14. Chemoprevention and cytotoxic effect of Bauhinia variegata against N-nitrosodiethylamine induced liver tumors and human cancer cell lines.

    Science.gov (United States)

    Rajkapoor, B; Jayakar, B; Murugesh, N; Sakthisekaran, D

    2006-04-06

    The chemopreventive and cytotoxic effect of ethanol extract of Bauhinia variegata (EBV) was evaluated in N-nitrosodiethylamine (DEN, 200 mg/kg) induced experimental liver tumor in rats and human cancer cell lines. Oral administration of ethanol extract of Bauhinia variegata (250 mg/kg) effectively suppressed liver tumor induced by DEN as revealed by decrease in DEN induced elevated levels of serum glutamate pyruvate transaminase (SGPT), serum glutamate oxaloacetate transaminase (SGOT), alkaline phosphatase (ALP), total bilirubin, gamma glutamate transpeptidase (GGTP), lipid peroxidase (LPO), glutathione peroxidase (GPx) and glutathione S-transferase (GST). The extract produced an increase in enzymatic antioxidant (superoxide dismutase and catalase) levels and total proteins when compared to those in liver tumor bearing rats. The histopathological changes of liver samples were compared with respective controls. EBV was found to be cytotoxic against human epithelial larynx cancer (HEp2) and human breast cancer (HBL-100) cells. These results show a significant chemopreventive and cytotoxic effect of ethanol extract of Bauhinia variegata against DEN induced liver tumor and human cancer cell lines.

  15. Impact of Short-term 1,25-Dihydroxyvitamin D3 on the Chemopreventive Efficacy of Erlotinib against Oral Cancer.

    Science.gov (United States)

    Bothwell, Katelyn D; Shaurova, Tatiana; Merzianu, Mihai; Suresh, Amritha; Kuriakose, Moni A; Johnson, Candace S; Hershberger, Pamela A; Seshadri, Mukund

    2015-09-01

    Activation of the epidermal growth factor receptor (EGFR) pathway is an early event in head and neck carcinogenesis. As a result, targeting EGFR for chemoprevention of head and neck squamous cell carcinomas (HNSCC) has received considerable attention. In the present study, we examined the impact of 1,25(OH)2D3, the active metabolite of the nutritional supplement vitamin D on the chemopreventive efficacy of the EGFR inhibitor, erlotinib, against HNSCC. Experimental studies were conducted in patient-derived xenografts (PDX) and the 4-nitroquinoline-1-oxide (4NQO) carcinogen-induced model of HNSCC. Short-term treatment (4 weeks) of PDX-bearing mice with 1,25(OH)2D3 and erlotinib resulted in significant inhibition of tumor growth. Noninvasive MRI enabled longitudinal monitoring of disease progression in the 4NQO model with 100% of control animals showing evidence of neoplastic lesions by 24 weeks. Among the experimental groups, animals treated with the combination regimen showed the greatest reduction in tumor incidence and volume (P phospho-EGFR and phospho-Akt with the combination regimen. These results highlight the potential of 1,25(OH)2D3 to augment the efficacy of erlotinib against HNSCC. Further optimization of schedule and sequence of this combination regimen along with investigation into the activity of less calcemic analogues or dietary vitamin D is essential to fully realize the potential of this approach.

  16. Resveratrol mobilizes endogenous copper in human peripheral lymphocytes leading to oxidative DNA breakage: a putative mechanism for chemoprevention of cancer.

    Science.gov (United States)

    Hadi, S M; Ullah, M F; Azmi, A S; Ahmad, A; Shamim, U; Zubair, H; Khan, H Y

    2010-06-01

    Plant polyphenols are important components of human diet, and a number of them are considered to possess chemopreventive and therapeutic properties against cancer. They are recognized as naturally occurring anti-oxidants but also act as pro-oxidants catalyzing DNA degradation in the presence of metal ions such as copper. The plant polyphenol resveratrol confers resistance to plants against fungal agents and has been implicated as a cancer chemopreventive agent. Of particular interest is the observation that resveratrol has been found to induce apoptosis in cancer cell lines but not in normal cells. Over the last few years, we have shown that resveratrol is capable of causing DNA breakage in cells such as human lymphocytes. Such cellular DNA breakage is inhibited by copper specific chelators but not by iron and zinc chelating agents. Similar results are obtained by using permeabilized cells or with isolated nuclei, indicating that chromatin-bound copper is mobilized in this reaction. It is well established that tissue, cellular and serum copper levels are considerably elevated in various malignancies. Therefore, cancer cells may be more subject to electron transfer between copper ions and resveratrol to generate reactive oxygen species responsible for DNA cleavage. The results are in support of our hypothesis that anti-cancer mechanism of plant polyphenols involves mobilization of endogenous copper and the consequent pro-oxidant action. Such a mechanism better explains the anti-cancer effects of resveratrol, as it accounts for the preferential cytotoxicity towards cancer cells.

  17. Naturally-Occurring Glucosinolates, Glucoraphanin and Glucoerucin, are Antagonists to Aryl Hydrocarbon Receptor as Their Chemopreventive Potency.

    Science.gov (United States)

    Abdull Razis, Ahmad Faizal; Noor, Noramaliza Mohd

    2015-01-01

    As a cytosolic transcription factor, the aryl hydrocarbon (Ah) receptor is involved in several patho- physiological events leading to immunosuppression and cancer; hence antagonists of the Ah receptor may possess chemoprevention properties. It is known to modulate carcinogen-metabolising enzymes, for instance the CYP1 family of cytochromes P450 and quinone reductase, both important in the biotransformation of many chemical carcinogens via regulating phase I and phase II enzyme systems. Utilising chemically-activated luciferase expression (CALUX) assay it was revealed that intact glucosinolates, glucoraphanin and glucoerucin, isolated from Brassica oleracea L. var. acephala sabellica and Eruca sativa ripe seeds, respectively, are such antagonists. Both glucosinolates were poor ligands for the Ah receptor; however, they effectively antagonised activation of the receptor by the avid ligand benzo[a]pyrene. Indeed, intact glucosinolate glucoraphanin was a more potent antagonist to the receptor than glucoerucin. It can be concluded that both glucosinolates effectively act as antagonists for the Ah receptor, and this may contribute to their established chemoprevention potency.

  18. Chemopreventive effects of free and bound phenolics associated to steep waters (nejayote) obtained after nixtamalization of different maize types.

    Science.gov (United States)

    Rojas-García, Carlos; García-Lara, Silverio; Serna-Saldivar, Sergio O; Gutiérrez-Uribe, Janet A

    2012-03-01

    Free and bound phenolics extracts from nejayote solids were obtained after optimally lime-cooking blue, normal white, red, normal yellow, high-carotenoid and quality protein maize types. The extraction yield ranged from 4.47 to 10.05%. Bound phenolics extracts had higher content of total phenolics, antioxidant activity and ferulic acid compared to the free phenolics extracts. In general, free phenolics extracts were less cytotoxic than the bound phenolics counterparts. Bound phenolics extracts had higher induction of quinone reductase (QR) and particularly the normal yellow nejayote exerted the highest chemopreventive index tested in Hepa1c1c7 cells. When tested for monofunctional phase 2 induction capacity in BPrc1 cells, the bound phenolics extracts of blue, normal white and quality protein nejayotes were better inducers than the normal yellow counterpart. Particularly, the free phenolics extract of the white maize nejayote induced BPrc1 cells QR and exerted a higher chemopreventive index compared to the bound phenolics extract. Therefore, the nejayote of the normal white maize was the best source of monofunctional phase 2 enzyme inducers.

  19. Raman spectroscopic investigation of the chemopreventive response of naringenin and its nanoparticles in DMBA-induced oral carcinogenesis

    Science.gov (United States)

    Krishnakumar, N.; Sulfikkarali, N. K.; Manoharan, S.; Venkatachalam, P.

    2013-11-01

    Raman spectroscopy is a vibrational spectroscopic technique that can be used to optically probe the biomolecular changes associated with tumor progression. The aim of the present study is to investigate the biomolecular changes in chemopreventive response of prepared naringenin-loaded nanoparticles (NARNPs) relative to efficacy of free naringenin (NAR) during 7,12-dimethyl benz(a)anthracene (DMBA)-induced oral carcinogenesis by Fourier Transform Raman (FT-Raman) spectroscopy. Oral squamous cell carcinoma (OSCC) was developed in the buccal pouch of golden Syrian hamsters by painting with 0.5% DMBA in liquid paraffin three times a week for 14 weeks. Raman spectra differed significantly between the control and tumor tissues, with tumors showing higher percentage signals for nucleic acids, phenylalanine and tryptophan and a lower in the percentage of phospholipids. Moreover, oral administration of free NAR and NARNPs significantly increased phospholipids and decreased the levels of tryptophan, phenylalanine and nucleic acid contents. On a comparative basis, NARNPs was found to have a more potent antitumor effect than free NAR in completely preventing the formation of squamous cell carcinoma and in improving the biochemical status to a normal range in DMBA-induced oral carcinogenesis. The present study further suggest that Raman spectroscopy could be a valuable tool for rapid and sensitive detection of specific biomolecular changes in response to chemopreventive agents.

  20. A Review of Routing Protocols in Wireless Body Area Networks

    Directory of Open Access Journals (Sweden)

    Samaneh Movassaghi

    2013-03-01

    Full Text Available Recent technological advancements in wireless communication, integrated circuits and Micro-Electro-Mechanical Systems (MEMs has enabled miniaturized, lowpower, intelligent, invasive/ non-invasive micro and nanotechnology sensor nodes placed in or on the human body for use in monitoring body function and its immediate environment referred to as Body Area Networks (BANs. BANs face many stringent requirements in terms of delay, power, temperature and network lifetime which need to be taken into serious consideration in the design of different protocols. Since routing protocols play an important role in the overall system performance in terms of delay, power consumption, temperature and so on, a thorough study on existing routing protocols in BANs is necessary. Also, the specific challenges of BANs necessitates the design of new routing protocols specifically designed for BANs. This paper provides a survey of existing routing protocols mainly proposed for BANs. These protocols are further classified into five main categories namely, temperature based, crosslayer, cluster based, cost-effective and QoS-based routing, where each protocol is described under its specified category. Also, comparison among routing protocols in each category is given.

  1. A review of animal model studies of tomato carotenoids, lycopene, and cancer chemoprevention.

    Science.gov (United States)

    Cohen, Leonard A

    2002-11-01

    There are relatively few reports on the cancer chemopreventive effects of lycopene or tomato carotenoids in animal models. The majority, but not all, of these studies indicate a protective effect. Inhibitory effects were reported in two studies using aberrant crypt foci, an intermediate lesion leading to colon cancer, as an end point and in two mammary tumor studies, one using the dimethylbenz(a)anthracene model, and the other the spontaneous mouse model. Inhibitory effects were also reported in mouse lung and rat hepatocarcinoma and bladder cancer models. However, a report from the author's laboratory found no effect in the N-nitrosomethylurea-induced mammary tumor model when crystalline lycopene or a lycopene-rich tomato carotenoid oleoresin was administered in the diet. Unfortunately, because of differences in routes of administration (gavage, intraperitoneal injection, intra-rectal instillation, drinking water, and diet supplementation), species and strain differences, form of lycopene (pure crystalline, beadlet, mixed carotenoid suspension), varying diets (grain-based, casein based) and dose ranges (0.5-500 ppm), no two studies are comparable. It is clear that the majority of ingested lycopene is excreted in the feces and that 1000-fold more lycopene is absorbed and stored in the liver than accumulates in other target organs. Nonetheless, physiologically significant (nanogram) levels of lycopene are assimilated by key organs such as breast, prostate, lung, and colon, and there is a rough dose-response relationship between lycopene intake and blood levels. Pure lycopene was absorbed less efficiently than the lycopene-rich tomato carotenoid oleoresin and blood levels of lycopene in rats fed a grain-based diet were consistently lower than those in rats fed lycopene in a casein-based diet. The latter suggests that the matrix in which lycopene is incorporated is an important determinant of lycopene uptake. A number of issues remain to be resolved before any

  2. Bayesian adaptive survey protocols for resource management

    Science.gov (United States)

    Halstead, Brian J.; Wylie, Glenn D.; Coates, Peter S.; Casazza, Michael L.

    2011-01-01

    Transparency in resource management decisions requires a proper accounting of uncertainty at multiple stages of the decision-making process. As information becomes available, periodic review and updating of resource management protocols reduces uncertainty and improves management decisions. One of the most basic steps to mitigating anthropogenic effects on populations is determining if a population of a species occurs in an area that will be affected by human activity. Species are rarely detected with certainty, however, and falsely declaring a species absent can cause improper conservation decisions or even extirpation of populations. We propose a method to design survey protocols for imperfectly detected species that accounts for multiple sources of uncertainty in the detection process, is capable of quantitatively incorporating expert opinion into the decision-making process, allows periodic updates to the protocol, and permits resource managers to weigh the severity of consequences if the species is falsely declared absent. We developed our method using the giant gartersnake (Thamnophis gigas), a threatened species precinctive to the Central Valley of California, as a case study. Survey date was negatively related to the probability of detecting the giant gartersnake, and water temperature was positively related to the probability of detecting the giant gartersnake at a sampled location. Reporting sampling effort, timing and duration of surveys, and water temperatures would allow resource managers to evaluate the probability that the giant gartersnake occurs at sampled sites where it is not detected. This information would also allow periodic updates and quantitative evaluation of changes to the giant gartersnake survey protocol. Because it naturally allows multiple sources of information and is predicated upon the idea of updating information, Bayesian analysis is well-suited to solving the problem of developing efficient sampling protocols for species of

  3. Adenosine stress protocols for myocardial perfusion imaging

    Directory of Open Access Journals (Sweden)

    Baškot Branislav

    2008-01-01

    Full Text Available Background/Aim. Treadmill test combined with myocardial perfusion scintigraphy (MPS is a commonly used technique in the assessment of coronary artery disease. There are many patients, however, who may not be able to undergo treadmill test. Such patients would benefit from pharmacological stress procedures combined with MPS. The most commonly used pharmacological agents for cardiac stress are coronary vasodilatators (adenosine, dipyridamol and catecholamines. Concomitant low-level treadmill exercise with adenosine pharmacologic stress (AdenoEX during MPS has become commonly used in recent years. A number of studies have demonstrated a beneficial impact of AdenoEX protocol. The aim of the study was, besides introducing into practice the two types of protocols of pharmatological stress test with adenosine, as a preparation for MPS, to compare and monitor the frequency of their side effects to quality, acquisition, as well as to standardize the onset time of acquisition (diagnostic imaging for both protocols. Methods. A total of 130 patients underwent pharmacological stress test with adenosine (vasodilatator. In 108 of the patients we performed concomitant exercise (AdenoEX of low level (50W by a bicycle ergometar. In 28 of the patients we performed Adenosine abbreviated protocol (AdenoSCAN. Side effects of adenosine were followed and compared between the two kinds of protocols AdenoEX and AdenoSCAN. Also compared were image quality and suggested time of acquisition after the stress test. Results. Numerous side effects were found, but being short-lived they did not require any active interventions. The benefit of AdenoEX versus AdenoSCAN included decreased side effects (62% vs 87%, improved safety and patients tolerance, improved target-to-background ratios because of less subdiaphragmatic activity, earlier acquisition, and improved sensitivity. Conclusion. The safety and efficacy of adenosine pharmacological stress is even better with concomitant

  4. Internet Protocol Television (IPTV

    Directory of Open Access Journals (Sweden)

    Lokesh Mittal

    2012-09-01

    Full Text Available IPTV is one of the mostly used technology of Internet and IP application. IPTV is a service for the delivery of broadcast TV, movies on demand and other interactive multimedia services over a secure, end-to-end operator managed broadband IP data network with desired QoS to the public with a broadband Internet connection. IPTV system may also include Internet services such as Web access and VoIP where it may be called Triple Play and is typically supplied by a broadband operator using the same infrastructure. IPTV is not the Internet Video that simply allows users to watch videos, like movie previews and web-cams, over the Internet in a best effort fashion. IPTV technology offers revenue-generating opportunities for the telecom and cable service providers. For traditional telephone service providers, Triple Play is delivered using a combination of optical fiber and Digital Subscriber Line (DSL technologies to its residential base. IPTV is a system where a digital television service is delivered by using Internet Protocol over a network infrastructure, which may include delivery by a broadband connection. A general definition of IPTV is television content that, instead of being delivered through traditional broadcast and cable formats, is received by the viewer through the technologies used for computer networks. In this paper I am trying to discuss this topic as my knowledge, including what is IPTV, how it works, its advantages and its applications

  5. Evaluation of OLSR Protocol Implementations using Analytical Hierarchical Process (AHP

    Directory of Open Access Journals (Sweden)

    Ashfaq Ahmad Malik

    2016-11-01

    Full Text Available Adhoc networks are part of IEEE 802.11 Wireless LAN Standard also called Independent Basic Service Set (IBSS and work as Peer to Peer network by default. These work without the requirement of an Infrastructure (such as an Access Point and demands specific routing requirements to work as a multi-hop network. There are various Adhoc network routing protocols which are categorized as Proactive, Reactive and Hybrid. OLSR (a proactive routing protocol is one of widely used routing protocols in adhoc networks. In this paper an empirical study and analysis of the various OLSR implementations (by different research groups and individuals has been conducted in light of Relative Opinion Scores (ROS and Analytical Hierarchical Process (AHP Online System software. Based on quantitative comparison of results, it is concluded that OLSRd project is most updated and best amongst six variants of OLSR protocol implementations.

  6. Voice over Internet Protocol (VOIP: Future Potential

    Directory of Open Access Journals (Sweden)

    Ms. Deepti

    2014-11-01

    Full Text Available VoIP (voice over IP delivers standard voice over telephone services over Internet Protocol (IP. VoIP is the technology of digitizing sound, compressing it, breaking it up into data packets, and sending it over an IP (internet protocol network where it is reassembled, decompressed, and converted back into an analog wave form. Gateways are the key component required to facilitate IP Telephony. A gateway is used to bridge the traditional circuit switched PSTN with the packet switched Internet. The paper covers software, hardware and protocol requirements followed by weighing the VoIP advantages such as low cost, portability, free and advanced features, bandwidth efficiency, call recording and monitoring against the VoIP disadvantages such as power dependency, quality of voice and service, security, and reliability. With ever increasing internet penetration and better broadband connectivity, VoIP is going to expand further with businesses already using VoIP standalone or in a hybrid format, although our focus and scope here remains VoIP. Mobile VoIP, an infant with less than 4% market share, has so far been focusing on increasing active subscriptions without a sustainable revenue model, but has the potential and is going to see tussle with static VoIP for space in days ahead.

  7. VOICE OVER INTERNET PROTOCOL (VOIP: FUTURE POTENTIAL

    Directory of Open Access Journals (Sweden)

    Deepti Kumari

    2015-10-01

    Full Text Available VoIP (voice over IP delivers standard voice over telephone services over Internet Protocol (IP. VoIP is the technology of digitizing sound, compressing it, breaking it up into data packets, and sending it over an IP (internet protocol network where it is reassembled, decompressed, and converted back into an analog wave form. Gateways are the key component required to facilitate IP Telephony. A gateway is used to bridge the traditional circuit switched PSTN with the packet switched Internet. The paper covers software, hardware and protocol requirements followed by weighing the VoIP advantages such as low cost, portability, free and advanced features, bandwidth efficiency, call recording and monitoring against the VoIP disadvantages such as power dependency, quality of voice and service, security, and reliability. With ever increasing internet penetration and better broadband connectivity, VoIP is going to expand further with businesses already using VoIP standalone or in a hybrid format, although our focus and scope here remains VoIP. Mobile VoIP, an infant with less than 4% market share, has so far been focusing on increasing active subscriptions without a sustainable revenue model, but has the potential and is going to see tussle with static VoIP for space in days ahead.

  8. Analysis of Security Protocols for Mobile Healthcare.

    Science.gov (United States)

    Wazid, Mohammad; Zeadally, Sherali; Das, Ashok Kumar; Odelu, Vanga

    2016-11-01

    Mobile Healthcare (mHealth) continues to improve because of significant improvements and the decreasing costs of Information Communication Technologies (ICTs). mHealth is a medical and public health practice, which is supported by mobile devices (for example, smartphones) and, patient monitoring devices (for example, various types of wearable sensors, etc.). An mHealth system enables healthcare experts and professionals to have ubiquitous access to a patient's health data along with providing any ongoing medical treatment at any time, any place, and from any device. It also helps the patient requiring continuous medical monitoring to stay in touch with the appropriate medical staff and healthcare experts remotely. Thus, mHealth has become a major driving force in improving the health of citizens today. First, we discuss the security requirements, issues and threats to the mHealth system. We then present a taxonomy of recently proposed security protocols for mHealth system based on features supported and possible attacks, computation cost and communication cost. Our detailed taxonomy demonstrates the strength and weaknesses of recently proposed security protocols for the mHealth system. Finally, we identify some of the challenges in the area of security protocols for mHealth systems that still need to be addressed in the future to enable cost-effective, secure and robust mHealth systems.

  9. Quantum Clock Synchronization a Multi-Party Protocol

    CERN Document Server

    Krco, M; Krco, Marko; Paul, Prabasaj

    2001-01-01

    We present a multi-party quantum clock synchronization protocol that utilizes shared prior entanglement and broadcast of classical information to synchronize spatially separated clocks. Notably, it is necessary only for any one party to publish classical information. Consequently, the efficacy of the method is independent of the relative location of the parties. The suggested protocol is robust and does not require precise sequencing of procedural steps.

  10. Internet-Protocol-Based Satellite Bus Architecture Designed

    Science.gov (United States)

    Slywczak, Richard A.

    2004-01-01

    NASA is designing future complex satellite missions ranging from single satellites and constellations to space networks and sensor webs. These missions require more interoperability, autonomy, and coordination than previous missions; in addition, a desire exists to have scientists retrieve data directly from the satellite rather than a central distribution source. To meet these goals, NASA has been studying the possibility of extending the Transmission Control Protocol/Internet Protocol (TCP/IP) suite for spacebased applications.

  11. Sulforaphane, a cancer chemopreventive agent, induces pathways associated with membrane biosynthesis in response to tissue damage by aflatoxin B{sub 1}

    Energy Technology Data Exchange (ETDEWEB)

    Techapiesancharoenkij, Nirachara [Laboratory of Environmental Toxicology, Chulabhorn Research Institute, Bangkok 10210 (Thailand); Fiala, Jeannette L.A. [Department of Biological Engineering and Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States); Navasumrit, Panida [Laboratory of Environmental Toxicology, Chulabhorn Research Institute, Bangkok 10210 (Thailand); Croy, Robert G.; Wogan, Gerald N. [Department of Biological Engineering and Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States); Groopman, John D. [Department of Environmental Health Sciences, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205 (United States); Ruchirawat, Mathuros [Laboratory of Environmental Toxicology, Chulabhorn Research Institute, Bangkok 10210 (Thailand); Essigmann, John M., E-mail: jessig@mit.edu [Department of Biological Engineering and Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States)

    2015-01-01

    Aflatoxin B{sub 1} (AFB{sub 1}) is one of the major risk factors for liver cancer globally. A recent study showed that sulforaphane (SF), a potent inducer of phase II enzymes that occurs naturally in widely consumed vegetables, effectively induces hepatic glutathione S-transferases (GSTs) and reduces levels of hepatic AFB{sub 1}-DNA adducts in AFB{sub 1}-exposed Sprague Dawley rats. The present study characterized the effects of SF pre-treatment on global gene expression in the livers of similarly treated male rats. Combined treatment with AFB{sub 1} and SF caused reprogramming of a network of genes involved in signal transduction and transcription. Changes in gene regulation were observable 4 h after AFB{sub 1} administration in SF-pretreated animals and may reflect regeneration of cells in the wake of AFB{sub 1}-induced hepatotoxicity. At 24 h after AFB{sub 1} administration, significant induction of genes that play roles in cellular lipid metabolism and acetyl-CoA biosynthesis was detected in SF-pretreated AFB{sub 1}-dosed rats. Induction of this group of genes may indicate a metabolic shift toward glycolysis and fatty acid synthesis to generate and maintain pools of intermediate molecules required for tissue repair, cell growth and compensatory hepatic cell proliferation. Collectively, gene expression data from this study provide insights into molecular mechanisms underlying the protective effects of SF against AFB{sub 1} hepatotoxicity and hepatocarcinogenicity, in addition to the chemopreventive activity of this compound as a GST inducer. - Highlights: • This study revealed sulforaphane (SF)-deregulated gene sets in aflatoxin B{sub 1} (AFB{sub 1})-treated rat livers. • SF redirects biochemical networks toward lipid biosynthesis in AFB{sub 1}-dosed rats. • SF enhanced gene sets that would be expected to favor cell repair and regeneration.

  12. Randomized, Double-Blind, Placebo-Controlled, Phase III Chemoprevention Trial of Selenium Supplementation in Patients With Resected Stage I Non–Small-Cell Lung Cancer: ECOG 5597

    Science.gov (United States)

    Karp, Daniel D.; Lee, Sandra J.; Keller, Steven M.; Wright, Gail Shaw; Aisner, Seena; Belinsky, Steven Alan; Johnson, David H.; Johnston, Michael R.; Goodman, Gary; Clamon, Gerald; Okawara, Gordon; Marks, Randolph; Frechette, Eric; McCaskill-Stevens, Worta; Lippman, Scott M.; Ruckdeschel, John; Khuri, Fadlo R.

    2013-01-01

    Purpose Selenium has been reported to have chemopreventive benefits in lung cancer. We conducted a double-blind, placebo-controlled trial to evaluate the incidence of second primary tumors (SPTs) in patients with resected non–small-cell lung cancer (NSCLC) receiving selenium supplementation. Patients and Methods Patients with completely resected stage I NSCLC were randomly assigned to take selenized yeast 200 μg versus placebo daily for 48 months. Participation was 6 to 36 months postoperatively and required a negative mediastinal node biopsy, no excessive vitamin intake, normal liver function, negative chest x-ray, and no other evidence of recurrence. Results The first interim analysis in October 2009, with 46% of the projected end points accumulated, showed a trend in favor of the placebo group with a low likelihood that the trial would become positive; thus, the study was stopped. One thousand seven hundred seventy-two participants were enrolled, with 1,561 patients randomly assigned. Analysis was updated in June 2011 with the maturation of 54% of the planned end points. Two hundred fifty-two SPTs (from 224 patients) developed, of which 98 (from 97 patients) were lung cancer (38.9%). Lung and overall SPT incidence were 1.62 and 3.54 per 100 person-years, respectively, for selenium versus 1.30 and 3.39 per 100 person-years, respectively, for placebo (P = .294). Five-year disease-free survival was 74.4% for selenium recipients versus 79.6% for placebo recipients. Grade 1 to 2 toxicity occurred in 31% of selenium recipients and 26% of placebo recipients, and grade ≥ 3 toxicity occurred in less than 2% of selenium recipients versus 3% of placebo recipients. Compliance was excellent. No increase in diabetes mellitus or skin cancer was detected. Conclusion Selenium was safe but conferred no benefit over placebo in the prevention of SPT in patients with resected NSCLC. PMID:24002495

  13. Staining protocol for organotypic hippocampal slice cultures.

    Science.gov (United States)

    Gogolla, Nadine; Galimberti, Ivan; DePaola, Vincenzo; Caroni, Pico

    2006-01-01

    This protocol details a method to immunostain organotypic slice cultures from mouse hippocampus. The cultures are based on the interface method, which does not require special equipment, is easy to execute and yields slice cultures that can be imaged repeatedly, from the time of isolation at postnatal day 6-9 up to 6 months in vitro. The preserved tissue architecture facilitates the analysis of defined hippocampal synapses, cells and entire projections. Time-lapse imaging is based on transgenes expressed in the mice or on constructs introduced through transfection or viral vectors; it can reveal processes that develop over periods ranging from seconds to months. Subsequent to imaging, the slices can be processed for immunocytochemistry to collect further information about the imaged structures. This protocol can be completed in 3 d.

  14. Efficient Protocols for Distributed Classification and Optimization

    CERN Document Server

    Daume, Hal; Saha, Avishek; Venkatasubramanian, Suresh

    2012-01-01

    In distributed learning, the goal is to perform a learning task over data distributed across multiple nodes with minimal (expensive) communication. Prior work (Daume III et al., 2012) proposes a general model that bounds the communication required for learning classifiers while allowing for $\\eps$ training error on linearly separable data adversarially distributed across nodes. In this work, we develop key improvements and extensions to this basic model. Our first result is a two-party multiplicative-weight-update based protocol that uses $O(d^2 \\log{1/\\eps})$ words of communication to classify distributed data in arbitrary dimension $d$, $\\eps$-optimally. This readily extends to classification over $k$ nodes with $O(kd^2 \\log{1/\\eps})$ words of communication. Our proposed protocol is simple to implement and is considerably more efficient than baselines compared, as demonstrated by our empirical results. In addition, we illustrate general algorithm design paradigms for doing efficient learning over distribute...

  15. Gamma camera performance: technical assessment protocol

    Energy Technology Data Exchange (ETDEWEB)

    Bolster, A.A. [West Glasgow Hospitals NHS Trust, London (United Kingdom). Dept. of Clinical Physics; Waddington, W.A. [University College London Hospitals NHS Trust, London (United Kingdom). Inst. of Nuclear Medicine

    1996-12-31

    This protocol addresses the performance assessment of single and dual headed gamma cameras. No attempt is made to assess the performance of any associated computing systems. Evaluations are usually performed on a gamma camera commercially available within the United Kingdom and recently installed at a clinical site. In consultation with the manufacturer, GCAT selects the site and liaises with local staff to arrange a mutually convenient time for assessment. The manufacturer is encouraged to have a representative present during the evaluation. Three to four days are typically required for the evaluation team to perform the necessary measurements. When access time is limited, the team will modify the protocol to test the camera as thoroughly as possible. Data are acquired on the camera`s computer system and are subsequently transferred to the independent GCAT computer system for analysis. This transfer from site computer to the independent system is effected via a hardware interface and Interfile data transfer. (author).

  16. Protocols.io: Virtual Communities for Protocol Development and Discussion.

    Science.gov (United States)

    Teytelman, Leonid; Stoliartchouk, Alexei; Kindler, Lori; Hurwitz, Bonnie L

    2016-08-01

    The detailed know-how to implement research protocols frequently remains restricted to the research group that developed the method or technology. This knowledge often exists at a level that is too detailed for inclusion in the methods section of scientific articles. Consequently, methods are not easily reproduced, leading to a loss of time and effort by other researchers. The challenge is to develop a method-centered collaborative platform to connect with fellow researchers and discover state-of-the-art knowledge. Protocols.io is an open-access platform for detailing, sharing, and discussing molecular and computational protocols that can be useful before, during, and after publication of research results.

  17. AN IMPROVED AUTHENTICATED KEY AGREEMENT PROTOCOL

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    In 1999, Seo and Sweeney proposed a simple authenticated key agreement protocol that was designed to act as a Diffie-Hellman key agreement protocol with user authentication.Various attacks on this protocol are described and enhanced in the literature. Recently, Ku and Wang proposed an improved authenticated key agreement protocol, where they asserted the protocol could withstand the existing attacks. This paper shows that Ku and Wang's protocol is still vulnerable to the modification attack and presents an improved authenticated key agreement protocol to enhance the security of Ku and Wang's protocol. The protocol has more efficient performance by replacing exponentiation operations with message authentication code operations.

  18. Potential Impact of Seasonal Malaria Chemoprevention on the Acquisition of Antibodies Against Glutamate-Rich Protein and Apical Membrane Antigen 1 in Children Living in Southern Senegal

    DEFF Research Database (Denmark)

    Ndiaye, Magatte; Sylla, Khadime; Sow, Doudou;

    2015-01-01

    Seasonal malaria chemoprevention (SMC) is defined as the intermittent administration of full treatment courses of an antimalarial drug to children during the peak of malaria transmission season with the aim of preventing malaria-associated mortality and morbidity. SMC using sulfadoxine-pyrimetham...

  19. Endoscopic spectral domain optical coherence tomography of murine colonic morphology to determine effectiveness of chemopreventive and chemotherapeutic agents in colorectal cancer

    Science.gov (United States)

    LeGendre-McGhee, Susan; Rice, Photini F. S.; Wall, R. Andrew; Klein, Justin; Luttman, Amber; Sprute, Kyle; Gerner, Eugene; Barton, Jennifer K.

    2012-02-01

    Optical coherence tomography (OCT) is a minimally-invasive imaging modality capable of tracking the development of individual colonic adenomas. As such, OCT can be used to evaluate the mechanisms and effectiveness of chemopreventive and chemotherapeutic agents in colorectal cancer models. The data presented here represent part of a larger study evaluating α-difluoromethylornithine (DFMO) and Sulindac as chemopreventive and chemotherapeutic agents using mice treated with the carcinogen azoxymethane (AOM). 27 A/J mice were included in the chemoprevention study, subdivided into four treatment groups (No Drug, DFMO, Sulindac, DFMO/Sulindac). 30 mm lateral images of each colon at eight different rotations were obtained at five different time points using a 2 mm diameter spectral domain OCT endoscopy system centered at 890 nm with 3.5 μm axial resolution in air and 5 μm lateral resolution. Images were visually analyzed to determine number and size of adenomas. Gross photos of the excised colons and histology provided gold standard confirmation of the final imaging time point. Preliminary results show that 100% of mice in the No Drug group developed adenomas over the course of the chemoprevention study. Incidence was reduced to 71.43% in mice given DFMO, 85.71% for Sulindac and 0% for DFMO/Sulindac. Discrete adenoma size did not vary significantly between experimental groups. Additional experiments are currently under way to verify these results and evaluate DFMO and Sulindac for chemotherapeutic applications.

  20. An effective and simple procedure to isolate abundant quantities of biologically active chemopreventive lunasin-protease inhibitor concentrate (LPIC) from soybean

    Science.gov (United States)

    Lunasin is a 5-kDa soybean bioactive peptide with demonstrated anti-cancer and anti-inflammatory properties. The use of lunasin as a chemopreventive agent in large-scale animal studies and human clinical trials is hampered by the paucity of large quantities of lunasin. Recently, purification methods...

  1. Review article : the potential of combinational regimen with non-steroidal anti-inflammatory drugs in the chemoprevention of colorectal cancer

    NARCIS (Netherlands)

    Jalving, M; Koornstra, JJ; De Jong, S; De Vries, EGE; Kleibeuker, JH

    2005-01-01

    Non-steroidal anti-inflammatory drugs are chemopreventive agents in colorectal cancer. Non-steroidal anti-inflammatory drugs do not, however, offer complete protection against adenoma and carcinoma development. There is increasing interest in combining non-steroidal anti-inflammatory drugs with agen

  2. From chemoprevention and organ preservation programmes to postoperative management : major achievements and strategies of the EORTC Head and Neck Cancer Group

    NARCIS (Netherlands)

    Bernier, J; Vermorken, JB; Debruyne, C; Andry, G; Licitra, L; Grandi, C; Langendijk, H; De Mulder, PHM; Lefebvre, JL

    2002-01-01

    The purpose of this article is to review the most significant results of the clinical studies conducted in the past two decades by the EORTC Head and Neck Cancer Group (HNCG). As for phase III trials. the HNCG investigated. besides the efficacy of chemopreventive drugs, the impact of cytostatic agen

  3. High-Bandwidth Tactical-Network Data Analysis in a High-Performance-Computing (HPC) Environment: Transport Protocol (Transmission Control Protocol/User Datagram Protocol [TCP/UDP]) Analysis

    Science.gov (United States)

    2015-09-01

    Protocol [TCP/UDP]) Analysis 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Kenneth D Renard and James R Adametz...guaranteed and ordered delivery of data from application to application. Internet Protocol ( IP ) does not guarantee either of these capabilities...that require reliable transport services, careful examination of TCP protocol performance is necessary. Data collected during test events includes IP

  4. SIP protocol model for OMNET++

    Directory of Open Access Journals (Sweden)

    Jan Kucerak

    2016-01-01

    Full Text Available The article describes our new SIP protocol implementation for the OMNeT++ simulation framework. OMNeT++ simulation framework provides an extensive support of IP related protocols, nevertheless a working SIP protocol implementation is missing. Real measurements were also done using a SIPp traffic generator and the results are compared to those obtained by our new SIP model. Since this work is a part of bigger project concerned strictly on measuring "first response times" over networks with a faulty transmission links, the actually collected statistics are focused only this way.

  5. 肺癌化学药物预防的研究进展%Research progress on lung cancer chemoprevention

    Institute of Scientific and Technical Information of China (English)

    刘乾; 徐卫国

    2014-01-01

    肺癌是世界范围内癌症致死的首要原因。近年来,针对肺癌的传统治疗手段虽不断发展和改善,但肺癌的病死率未明显改变。除了大力倡导戒烟,化学药物预防有望降低肺癌的发生及抑制肺癌的发展,从而成为近年来研究的热点。化学药物预防是应用饮食和/或药物来抑制或逆转肿瘤的形成,目前已成功用于某些恶性肿瘤的临床预防。虽然已有的研究未能找到有效预防肺癌的药物,但鉴于大部分肺癌的发生是支气管上皮经历正常分化、增生、化生、异常增生及癌变的过程,故找寻可以有效抑制或逆转癌前病变或癌前状态的药物就变得愈发重要。%Lung cancer is the leading cause of cancer death in the world.Most patients with lung cancer are not candidates for curative therapy,and new therapies have not made a substantial impact on survival.Chemoprevention can reverse or inhibit the carcinogenic process through the use of dietary or pharmaceutical agents and has been successfully applied to common malignancies other than lung.Despite previous studies in lung cancer chemoprevention failing to identify effective agents,since the development of most lung bronchogenic carcinoma in the central bronchial epithelium starts with normal epithelium and progresses through hyperplasia,metaplasia,dysplasia,carcinoma in situ to invasive lung cancer.It is needed for effective lung cancer chemoprevention to reverse or inhibit the premalignant lesions.

  6. Interoperation between AODV protocol and AOHR protocol for mobile ad hoc networks

    Science.gov (United States)

    Wu, Shaochuan; Wang, Changhong; Zhang, Jiayan

    2009-12-01

    Although AOHR protocol has some excellent performance, no actual network utilizes AOHR as routing protocol. It is because that this protocol cannot interoperate with AODV protocol, which is the most famous routing protocol and used all over the world. The cost will be very huge to replace AODV protocol with AOHR protocol for existing networks, so the only feasible method is to modify AOHR protocol to interoperate with AODV as introduced in this paper. The simulation results prove that the modified AOHR protocol can help the existing AODV protocol provide routing service, and the interoperation of these two routing protocols is realized.

  7. Process for Reviewing Survey Protocols

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This document describes the process for conducting two types of reviews of survey protocols. A quick assessment is used to acknowledge and describe to potential...

  8. Assessment of Established Survey Protocols

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — A form and instructions for quickly and briefly assessing a previously (prior to 2013) reviewed or approved survey protocol for use as a National or Regional survey...

  9. National Elk Refuge vaccination protocol

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Proposal by the State of Wyoming, Wyoming Game and Fish Department, to vaccinate elk on the National Elk Refuge. The proposal provides a protocol for vaccinating elk...

  10. Improved Authenticated Multi-Key Agreement Protocol

    Institute of Scientific and Technical Information of China (English)

    ZHANG Hua; YUAN Zheng; WEN Qiaoyan

    2006-01-01

    Zhou et al give an attack on Harn's modified authenticated multi-key agreement protocol, and give a protocol that can prevent the unknown key-share attack. The paper points out that the protocol is vulnerable to a concatenation attack. This paper proposes an improved authenticated multi-key agreement protocol which shows how to make Harn's protocol more secure by modifying the signature and verification. And this protocol can escape the concatenation attack.

  11. MANETs performance analysis with dos attack at different routing protocols

    Directory of Open Access Journals (Sweden)

    Alaa Zain

    2015-05-01

    Full Text Available A Mobile Ad-Hoc Networks (MANET is widely used in many industrial and people's life applications, such as earth monitoring, natural disaster prevention, agriculture biomedical related applications, and many other areas. Security threat is one of the major aspects of MANET, as it is one of the basic requirements of wireless sensor network, yet this problem has not been sufficiently explored. The main purpose of this paper is to study different MANETs routing protocols with three scenarios of Denial of Service (DoS attacks on network layer using proactive routing protocol i.e. Optimized Link State Routing (OLSR and Reactive routing protocols like Ad hoc On-Demand Distance Vector (AODV, Hybrid routing protocols like Geographic Routing Protocol (GRP. Moreover, a comparative analysis of DoS attacks for throughput, Data loss, delay and network load is taken into account. The performance of MANET under the attack is studied to find out which protocol is more vulnerable to the attack and how much is the impact of the attack on both protocols. The simulation is done using OPNET 17.

  12. Formal Modeling of Communication Protocols.

    Science.gov (United States)

    1981-03-01

    problems have been developed. 4 FORMAL MODELING OF COMMUNICATION PROTOCOLS The state machine model is motivated by the observation that protocols may be...simplest types of state machine model because they have only a single state variable (the state) which takes on a relatively small range of values. For...grammar, this correspondence is very apparent. For each state of the state machine model , we define a nonterminal symbol in the grammar. The inputs

  13. Cytochrome P450 1B1, a novel chemopreventive target for benzo[a]pyrene-initiated human esophageal cancer.

    Science.gov (United States)

    Wen, Xia; Walle, Thomas

    2007-02-08

    Esophageal cancer is common worldwide, with poor prognosis. Smoking, including exposure to polyaromatic hydrocarbons like benzo[a]pyrene (BaP), is a major risk factor. In human esophageal HET-1A cells, we found that time-dependent BaP-DNA binding was associated with upregulation of CYP1B1, but not CYP1A1, mRNA and protein. The dietary flavonoid 5,7-dimethoxyflavone significantly inhibited BaP-DNA binding and down-regulated BaP-induced CYP1B1 mRNA and protein. 3',4'-Dimethoxyflavone was an even more potent inhibitor of CYP1B1 expression, while resveratrol had no effect. Thus, dietary methoxylated flavones inhibited BaP-induced CYP1B1 transcription in a cell-specific manner and hold promise as chemopreventive agents in esophageal carcinogenesis.

  14. Chemopreventive potential of Tribulus terrestris against 7,12- dimethylbenz (a) anthracene induced skin papillomagenesis in mice.

    Science.gov (United States)

    Kumar, Manish; Soni, Anil Kumar; Shukla, Shalini; Kumar, Ashok

    2006-01-01

    In the present investigation, the chemopreventive potential of aqueous extracts of the root and fruit of Tribulus terrestris (an Ayurvedic medicinal plant) on 7, 12 - dimethylbenz (a) anthracene (DMBA) induced papillomagenesis in male Swiss albino mice was studied. A significant reduction in tumor incidence, tumor burden and cumulative number of papillomas was observed, along with a significant increase in average latent period in mice treated orally with Tribulus terrestris suspension continuously at pre, peri and post-initiation stages of papillomagenesis as compared to the control group treated with DMBA and croton oil alone. Treatment with Tribulus terrestris suspension by oral gavage for 7 days resulted in a significant increase in the reduced glutathione content in the liver (P< 0.001 for both root and fruit extracts). Conversely, lipid peroxidation levels were significantly decreased (P< 0.001).

  15. Downstream carcinogenesis signaling pathways by green tea polyphenols: a translational perspective of chemoprevention and treatment for cancers.

    Science.gov (United States)

    Hu, Guohua; Zhang, Lei; Rong, Yefei; Ni, Xiaoling; Sun, Yihong

    2014-01-01

    Green tea is one of the most popular beverages around the world. For several decades, numerous epidemiological, preclinical and clinical studies have demonstrated that green tea polyphenols (GTPs), especially epigallocatechin-3-gallate (EGCG) have cancer-preventing effects on various cancers. In this review, we present inhibition of carcinogenesis in different animal models by GTPs or EGCG, including prostate cancer, bladder cancer, breast cancer, intestinal cancer, colon cancer, gastric cancer, lung cancer, oral cancer and skin cancer. In vitro studies showed that GTPs/EGCG potently induces apoptosis, cell cycle arrest and suppresses metastasis in tumor cells but not in their normal cell counterparts. The molecular mechanisms of these activities are discussed in detail to elucidate GTPs/EGCG downstream carcinogenesis signaling pathways and their values of perspective of chemoprevention and treatment for cancers.

  16. Increased chemopreventive effect by combining arctigenin, green tea polyphenol and curcumin in prostate and breast cancer cells.

    Science.gov (United States)

    Wang, Piwen; Wang, Bin; Chung, Seyung; Wu, Yanyuan; Henning, Susanne M; Vadgama, Jaydutt V

    2014-08-05

    The low bioavailability of most flavonoids limits their application as anti-carcinogenic agents in humans. A novel approach of treatment with a mixture of bioactive compounds that share molecular anti-carcinogenic targets may enhance the effect on these targets at low concentrations of individual compound, thereby overcoming the limitations of reduced bioavailability. We therefore investigated whether a combination of three natural products arctigenin (Arc), a novel anti-inflammatory lignan from the seeds of Arctium lappa, green tea polyphenol (-)-epigallocatechin gallate (EGCG) and curcumin (Cur) increases the chemopreventive potency of individual compounds. LNCaP prostate cancer and MCF-7 breast cancer cells were treated with 2-4 mg/L (about 5-10μM) Cur, 1μM Arc and 40μM EGCG alone or in combination for 48h. In both cell lines treatment with the mixture of Cur, Arc and EGCG synergistically increased the antiproliferative effect. In LNCaP cells both Arc and EGCG increased the pro-apoptotic effect of Cur. Whereas in MCF-7 cells Arc increased the cell apoptosis of Cur while EGCG enhanced cell cycle arrest of Cur at G0/G1 phase. The strongest effects on cell cycle arrest and apoptosis were achieved by combining all three compounds in both cell lines. The combination treatment significantly increased the ratio of Bax to Bcl-2 proteins, decreased the activation of NFκB, PI3K/Akt and Stat3 pathways and cell migration compared to individual treatment. These results warrant in vivo studies to confirm the efficacy of this novel regimen by combining Arc and EGCG with Cur to enhance chemoprevention in both prostate and breast cancer.

  17. Identification of an unintended consequence of Nrf2-directed cytoprotection against a key tobacco carcinogen plus a counteracting chemopreventive intervention.

    Science.gov (United States)

    Paonessa, Joseph D; Ding, Yi; Randall, Kristen L; Munday, Rex; Argoti, Dayana; Vouros, Paul; Zhang, Yuesheng

    2011-06-01

    NF-E2-related factor 2 (Nrf2) is a major cytoprotective gene and is a key chemopreventive target against cancer and other diseases. Here we show that Nrf2 faces a dilemma in defense against 4-aminobiphenyl (ABP), a major human bladder carcinogen from tobacco smoke and other environmental sources. Although Nrf2 protected mouse liver against ABP (which is metabolically activated in liver), the bladder level of N-(deoxyguanosin-8-yl)-4-aminobiphenyl (dG-C8-ABP), the predominant ABP-DNA adduct formed in bladder cells and tissues, was markedly higher in Nrf2(+/+) mice than in Nrf2(-/-) mice after ABP exposure. Notably, Nrf2 protected bladder cells against ABP in vitro. Mechanistic investigations showed that the dichotomous effects of Nrf2 could be explained at least partly by upregulation of UDP-glucuronosyltransferase (UGT). Nrf2 promoted conjugation of ABP with glucuronic acid in the liver, increasing urinary excretion of the conjugate. Although glucuronidation of ABP and its metabolites is a detoxification process, these conjugates, which are excreted in urine, are known to be unstable in acidic urine, leading to delivery of the parent compounds to bladder. Hence, although higher liver UGT activity may protect the liver against ABP, it increases bladder exposure to ABP. These findings raise concerns of potential bladder toxicity when Nrf2-activating chemopreventive agents are used in humans exposed to ABP, especially in smokers. We further show that 5,6-dihydrocyclopenta[c][1,2]-dithiole-3(4H)-thione (CPDT) significantly inhibits dG-C8-ABP formation in bladder cells and tissues but does not seem to significantly modulate ABP-catalyzing UGT in liver. Thus, CPDT exemplifies a counteracting solution to the dilemma posed by Nrf2.

  18. Chemopreventive potential of β-Sitosterol in experimental colon cancer model - an In vitro and In vivo study

    Directory of Open Access Journals (Sweden)

    Paulraj Gabriel M

    2010-06-01

    Full Text Available Abstract Background Asclepias curassavica Linn. is a traditional medicinal plant used by tribal people in the western ghats, India, to treat piles, gonorrhoea, roundworm infestation and abdominal tumours. We have determined the protective effect of β-sitosterol isolated from A. curassavica in colon cancer, using in vitro and in vivo models. Methods The active molecule was isolated, based upon bioassay guided fractionation, and identified as β-sitosterol on spectral evidence. The ability to induce apoptosis was determined by its in vitro antiradical activity, cytotoxic studies using human colon adenocarcinoma and normal monkey kidney cell lines, and the expression of β-catenin and proliferating cell nuclear antigen (PCNA in human colon cancer cell lines (COLO 320 DM. The chemopreventive potential of β-sitosterol in colon carcinogenesis was assessed by injecting 1,2-dimethylhydrazine (DMH, 20 mg/kg b.w. into male Wistar rats and supplementing this with β-sitosterol throughout the experimental period of 16 weeks at 5, 10, and 20 mg/kg b.w. Results β-sitosterol induced significant dose-dependent growth inhibition of COLO 320 DM cells (IC50 266.2 μM, induced apoptosis by scavenging reactive oxygen species, and suppressed the expression of β-catenin and PCNA antigens in human colon cancer cells. β-sitosterol supplementation reduced the number of aberrant crypt and crypt multiplicity in DMH-initiated rats in a dose-dependent manner with no toxic effects. Conclusion We found doses of 10-20 mg/kg b.w. β-sitosterol to be effective for future in vivo studies. β-sitosterol had chemopreventive potential by virtue of its radical quenching ability in vitro, with minimal toxicity to normal cells. It also attenuated β-catenin and PCNA expression, making it a potential anticancer drug for colon carcinogenesis.

  19. Chemopreventive potential of β-Sitosterol in experimental colon cancer model - an In vitro and In vivo study

    Science.gov (United States)

    2010-01-01

    Background Asclepias curassavica Linn. is a traditional medicinal plant used by tribal people in the western ghats, India, to treat piles, gonorrhoea, roundworm infestation and abdominal tumours. We have determined the protective effect of β-sitosterol isolated from A. curassavica in colon cancer, using in vitro and in vivo models. Methods The active molecule was isolated, based upon bioassay guided fractionation, and identified as β-sitosterol on spectral evidence. The ability to induce apoptosis was determined by its in vitro antiradical activity, cytotoxic studies using human colon adenocarcinoma and normal monkey kidney cell lines, and the expression of β-catenin and proliferating cell nuclear antigen (PCNA) in human colon cancer cell lines (COLO 320 DM). The chemopreventive potential of β-sitosterol in colon carcinogenesis was assessed by injecting 1,2-dimethylhydrazine (DMH, 20 mg/kg b.w.) into male Wistar rats and supplementing this with β-sitosterol throughout the experimental period of 16 weeks at 5, 10, and 20 mg/kg b.w. Results β-sitosterol induced significant dose-dependent growth inhibition of COLO 320 DM cells (IC50 266.2 μM), induced apoptosis by scavenging reactive oxygen species, and suppressed the expression of β-catenin and PCNA antigens in human colon cancer cells. β-sitosterol supplementation reduced the number of aberrant crypt and crypt multiplicity in DMH-initiated rats in a dose-dependent manner with no toxic effects. Conclusion We found doses of 10-20 mg/kg b.w. β-sitosterol to be effective for future in vivo studies. β-sitosterol had chemopreventive potential by virtue of its radical quenching ability in vitro, with minimal toxicity to normal cells. It also attenuated β-catenin and PCNA expression, making it a potential anticancer drug for colon carcinogenesis. PMID:20525330

  20. Transcriptomic responses provide a new mechanistic basis for the chemopreventive effects of folic acid and tributyrin in rat liver carcinogenesis

    Science.gov (United States)

    Guariento, Aline H.; Furtado, Kelly S.; de Conti, Aline; Campos, Adriana; Purgatto, Eduardo; Carrilho, Jéssica; Shinohara, Elvira Maria Guerra; Tryndyak, Volodymyr; Han, Tao; Fuscoe, James C.; Ross, Sharon A.; Beland, Frederick A.; Pogribny, Igor P.; Moreno, Fernando S.

    2014-01-01

    The steady increase in the incidence and mortality of hepatocellular carcinoma (HCC) signifies a crucial need to understand better its pathogenesis to improve clinical management and prevention of the disease. The aim of this study was to investigate molecular mechanisms for the chemopreventive effects of folic acid and tributyrin alone or in combination on rat hepatocarcinogenesis. Male Wistar rats were subjected to a classic “resistant hepatocyte” model of liver carcinogenesis and treated with folic acid and tributyrin alone or in combination for 5 weeks during promotion stage. Treatment with folic acid and tributyrin alone or in combination strongly inhibited the development of glutathione-S-transferase placental form (GSTP)-positive foci. Microarray analysis showed significant changes in gene expression. A total of 501, 655, and 940 of differentially expressed genes, involved in cell cycle, p53-signaling, angiogenesis, and Wnt pathways, was identified in the livers of rats treated with folic acid, tributyrin or folic acid and tributyrin. A detailed analysis of these differentially expressed genes revealed that treatments inhibited angiogenesis in the preneoplastic livers. This was evidenced by the fact that 30 out of 77 differentially expressed genes common to all three treatments are involved in the regulation of the angiogenesis pathway. The inhibition of angiogenesis was confirmed by reduced levels of CD34 protein. In conclusion, the tumor-suppressing activity of folic acid and tributyrin is associated with inhibition of angiogenesis at early stages of rat liver carcinogenesis. Importantly, the combination of folic acid and tributyrin has stronger chemopreventive effect than each of the compounds alone. PMID:24302446

  1. Cancer chemopreventive effect of Spirogyra neglecta (Hassall) Kützing on diethylnitrosamine-induced hepatocarcinogenesis in rats.

    Science.gov (United States)

    Thumvijit, Tarika; Taya, Sirinya; Punvittayagul, Charatda; Peerapornpisal, Yuwadee; Wongpoomchai, Rawiwan

    2014-01-01

    Spirogyra neglecta, a freshwater green alga, is a local food in the northern and northeastern parts of Thailand. This investigation explored the anticarcinogenicity of S neglecta and its possible cancer chemopreventive mechanisms in rats divided into 14 groups. Groups 1 and 10 served as positive and negative control groups, respectively. Groups 1-9 were intraperitoneally injected with diethylnitrosamine (DEN) once a week for 3 weeks. Groups 10-14 received normal saline instead. One week after the last DEN injection, groups 2-5 were administered for 9 consecutive weeks various doses of S neglecta extract (SNE) and dried S neglecta (SND), mixed with basal diet. Groups 6-9 and 11-14 similarly were administered various doses of SNE and SND starting from the first week of the experiment. Administration of SNE and SND was not associated with formation of glutathione-S- transferase placental form (GST-P) positive foci in rat liver. SNE and SND during initiation phase significantly reduced the number of GST-P positive foci in rats injected with DEN. The number of GST-P also diminished in groups treated with SNE and SND after injection with DEN, except for the low dose extract group. SNE showed stronger anticarcinogenic potency than SND. Furthermore, SNE also decreased the number of Ki-67 positive cells. However, the numbers of TUNEL-positive cells in the liver of the SNE-treated groups were not statistically different from the controls. The GST activity in 50 mg/kg bw of SNE and 1% of SND groups was significantly increased as compared to the positive control. In conclusion, Spirogyra neglecta (Hassall) Kutzing showed cancer chemopreventive properties at the early stages of diethylnitrosamine-induced hepatocarcinogenesis in rats. Possible inhibitory mechanisms include enhancement of the activities of some detoxifying enzymes and/or suppression of precancerous cells.

  2. Evaluation of the chemopreventive response of naringenin-loaded nanoparticles in experimental oral carcinogenesis using laser-induced autofluorescence spectroscopy

    Science.gov (United States)

    Sulfikkarali, N. K.; Krishnakumar, N.

    2013-04-01

    The aim of the present study is to investigate the chemopreventive effects of prepared naringenin-loaded nanoparticles (NARNPs) relative to the efficacy of free naringenin (NAR) in modifying the carcinogenic process and to study the changes in the endogenous fluorophores during DMBA-induced hamster buccal pouch (HBP) carcinogenesis by laser-induced autofluorescence (LIAF) spectroscopy. LIAF emission spectra from the hamster buccal mucosa of the control and experimental groups of animals were recorded in the 350-700 nm spectral range on a miniature fiber optic spectrometer from different anatomical sites of each group, with excitation at 404 nm from a diode laser. Oral squamous cell carcinoma (OSCC) was developed in the buccal pouch of golden Syrian hamsters by painting with 0.5% DMBA in liquid paraffin three times a week for 14 weeks. DMBA-painted animals revealed morphological changes, hyperplasia, dysplasia and well-differentiated squamous cell carcinoma. LIAF emission spectra showed significant difference between the control and tumor tissues. The tumor tissues are characterized by an increase in the emission of porphyrins and a decrease in the emission of nicotinamide adenine dinucleotide hydrogenase (NADH) and flavin adenine nucleotide (FAD) when compared to the control tissues. Furthermore, oral administration of NAR and its nanoparticulates restored the status of endogenous fluorophores in the buccal mucosa of DMBA-painted animals. On a comparative basis, the treatment of nanoparticulate naringenin was found to be more effective than free naringenin in completely preventing the formation of squamous cell carcinoma and in improving the status of endogenous porphyrins to a normal range in DMBA-induced hamster buccal pouch carcinogenesis. The result of the present study further suggests that LIAF spectroscopy may be a very valuable tool for rapid and sensitive detection of endogenous fluorophore changes in response to chemopreventive agents.

  3. α-Santalol, a skin cancer chemopreventive agent with potential to target various pathways involved in photocarcinogenesis.

    Science.gov (United States)

    Santha, Sreevidya; Dwivedi, Chandradhar

    2013-01-01

    This study is designed to investigate the chemopreventive effect and molecular mechanisms of α-santalol on UVB-induced skin tumor development in SKH-1 hairless mouse, a widely used model for human photocarcinogenesis. A dose of UVB radiation (30 mJ cm(-2) day(-1)) that is in the range of human sunlight exposure was used for the initiation and promotion of tumor. Topical treatment of mice with α-santalol (10%, wt/vol in acetone) caused reduction in tumor incidence, multiplicity and volume. In our study, the anticarcinogenic action of α-santalol against UVB-induced photocarcinogenesis was found to be associated with inhibition of inflammation and epidermal cell proliferation, cell cycle arrest and induction of apoptosis. α-Santalol pretreatment strongly inhibited UVB-induced epidermal hyperplasia and thickness of the epidermis, expression of proliferation and inflammation markers proliferating cell nuclear antigen (PCNA), Ki-67 and cyclooxygenase 2 (Cox-2). Significant decrease in the expression of cyclins A, B1, D1 and D2 and cyclin-dependent kinases (Cdk)s Cdk1 (Cdc2), Cdk2, Cdk4 and Cdk6 and an upregulated expression of cyclin-dependent kinase (CDK) inhibitor Cip1/p21 were found in α-santalol pretreated group. Furthermore, an elevated level of cleaved caspase 3 and cleaved poly (ADP-ribose) polymerase (PARP) were observed in α-santalol-treated group. Our data suggested that α-santalol is a safer and promising skin cancer chemopreventive agent with potential to target various pathways involved in photocarcinogenesis.

  4. Efficient Controlled Quantum Secure Direct Communication Protocols

    OpenAIRE

    Patwardhan, Siddharth; Moulick, Subhayan Roy; Prasanta K. Panigrahi

    2015-01-01

    We study controlled quantum secure direct communication (CQSDC), a cryptographic scheme where a sender can send a secret bit-string to an intended recipient, without any secure classical channel, who can obtain the complete bit-string only with the permission of a controller. We report an efficient protocol to realize CQSDC using Cluster state and then go on to construct a (2-3)-CQSDC using Brown state, where a coalition of any two of the three controllers is required to retrieve the complete...

  5. Radiotherapy QA of the DAHANCA 19 protocol

    DEFF Research Database (Denmark)

    Samsøe, E.; Andersen, E.; Hansen, C. R.;

    2015-01-01

    trials. RT-QA of large multicentre-trials, however, requires substantial effort and resources. Recently, we presented a digital QA platform, the CIRRO dose plan bank, which allows for central review of such trials. Here, we present our RT-QA results from the latest completed clinical protocol from...... in CTV1 dose coverage were due to clinical considerations of the tolerance dose to the spinal cord, thus compromising target dose. Five of the major deviations in total treatment time were related to comorbidities, such as alcohol- or cardiac related matters and hospitalization. The remaining two cases...

  6. Neuroendocrine lung carcinogenesis in hamsters is inhibited by green tea or theophylline while the development of adenocarcinomas is promoted: implications for chemoprevention in smokers.

    Science.gov (United States)

    Schuller, Hildegard M; Porter, B; Riechert, A; Walker, K; Schmoyer, R

    2004-07-01

    Lung cancer continues to be the leading cause of cancer death in developed countries. With smoking the major etiological factor for lung cancer, there is a great need for the development of chemopreventive treatments that inhibit the progression of initiated cells and premalignant lesions into overt lung cancer in smokers who quit. Although the major focus of chemoprevention research has been on agents that inhibit the metabolic activation of genotoxic chemicals contained in tobacco products, some of these agents may additionally modulate growth-regulating signal transduction. In turn, the function of such signaling pathways is highly cell type-specific, with a given pathway inhibiting the growth of one cell type while stimulating the growth of others. The current experiment has tested the hypothesis that green tea and the methylxanthine theophylline contained in tea inhibit the progression of neuroendocrine lung carcinogenesis in hamsters with hyperoxic lung injury and initiated with the tobacco carcinogen 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) while promoting the development of Clara cell-derived pulmonary adenocarcinomas initiated by NNK in healthy hamsters. This hypothesis is based on published evidence that human small cell lung cancer as well as the neuroendocrine hamster tumors are regulated via autocrine signaling pathways that activate Raf-1 and the mitogen-activated (MAP) kinase pathway whereas human pulmonary adenocarcinomas of Clara cell lineage and the hamster model of this cancer type are regulated by a beta-adrenergic pathway involving the activation of cyclic adenosine 3',5'-monophosphate (cAMP) and the arachidonic acid (AA) cascade. In turn, it was hypothesized that theophylline would inhibit Raf-1-dependent tumor progression while promoting cAMP-dependent tumor progression due to its documented ability to inhibit the enzyme cAMP-phophodiesterase. The experimental design simulated chemoprevention in former smokers in that treatments

  7. Verification and validation of a reliable multicast protocol

    Science.gov (United States)

    Callahan, John R.; Montgomery, Todd L.

    1995-01-01

    This paper describes the methods used to specify and implement a complex communications protocol that provides reliable delivery of data in multicast-capable, packet-switching telecommunication networks. The protocol, called the Reliable Multicasting Protocol (RMP), was developed incrementally by two complementary teams using a combination of formal and informal techniques in an attempt to ensure the correctness of the protocol implementation. The first team, called the Design team, initially specified protocol requirements using a variant of SCR requirements tables and implemented a prototype solution. The second team, called the V&V team, developed a state model based on the requirements tables and derived test cases from these tables to exercise the implementation. In a series of iterative steps, the Design team added new functionality to the implementation while the V&V team kept the state model in fidelity with the implementation through testing. Test cases derived from state transition paths in the formal model formed the dialogue between teams during development and served as the vehicles for keeping the model and implementation in fidelity with each other. This paper describes our experiences in developing our process model, details of our approach, and some example problems found during the development of RMP.

  8. Satellite-Friendly Protocols and Standards

    Science.gov (United States)

    Koudelka, O.; Schmidt, M.; Ebert, J.; Schlemmer, H.; Kastner, S.; Riedler, W.

    2002-01-01

    We are currently observing a development unprecedented with other services, the enormous growth of the Internet. Video, voice and data applications can be supported via this network in high quality. Multi-media applications require high bandwidth which may not be available in many areas. When making proper use of the broadcast feature of a communications satellite, the performance of the satellite-based system can compare favourably to terrestrial solutions. Internet applications are in many cases highly asymmetric, making them very well suited to applications using small and inexpensive terminals. Data from one source may be used simultaneously by a large number of users. The Internet protocol suite has become the de-facto standard. But this protocol family in its original form has not been designed to support guaranteed quality of service, a prerequisite for real-time, high quality traffic. The Internet Protocol has to be adapted for the satellite environment, because long roundtrip delays and the error behaviour of the channel could make it inefficient over a GEO satellite. Another requirement is to utilise the satellite bandwidth as efficiently as possible. This can be achieved by adapting the access system to the nature of IP frames, which are variable in length. In the framework of ESA's ARTES project a novel satellite multimedia system was developed which utilises Multi-Frequency TDMA in a meshed network topology. The system supports Quality of Service (QoS) by reserving capacity with different QoS requirements. The system is centrally controlled by a master station with the implementation of a demand assignment (DAMA) system. A lean internal signalling system has been adopted. Network management is based on the SNMP protocol and industry-standard network management platforms, making interfaces to standard accounting and billing systems easy. Modern communication systems will have to be compliant to different standards in a very flexible manner. The

  9. Enhancement in Ad hoc on Demand Distance Vector (AODV) Routing Protocol Security

    Institute of Scientific and Technical Information of China (English)

    WANG Cui-rong; YANG Xiao-zong; GAO Yuan

    2005-01-01

    Ad-hoc networking has mainly been associated with military battlefield networks. Security has received considerably less attention and the issue needs to be addressed before any successful applications will appear. Due to the insecure nature of the wireless link and their dynamically changing topology, wireless ad-hoc networks require a careful and security-oriented approach for designing routing protocols.In this paper, an AODV-based secure routing protocolENAODV is presented. A speed-optimized digital signature algorithm is integrated into the routing protocol. The protocol algorithm is implemented with NS-2. The security of the protocol is analyzed. The simulating results show that the performances of ENAODV protocol, such as average node energy consumption, packet delay and packet delivery is nearly the same as standard AODV protocol.

  10. The mesh network protocol evaluation and development

    OpenAIRE

    Pei Ping; PETRENKO Y.N.

    2015-01-01

    In this paper, we introduce a Mesh network protocol evaluation and development. It has a special protocol. We could easily to understand that how different protocols are used in mesh network. In addition to our comprehension, Multi – hop routing protocol could provide robustness and load balancing to communication in wireless mesh networks.

  11. Cryptographic Protocols under Quantum Attacks

    CERN Document Server

    Lunemann, Carolin

    2011-01-01

    The realm of this thesis is cryptographic protocol theory in the quantum world. We study the security of quantum and classical protocols against adversaries that are assumed to exploit quantum effects to their advantage. Security in the quantum world means that quantum computation does not jeopardize the assumption, underlying the protocol construction. But moreover, we encounter additional setbacks in the security proofs, which are mostly due to the fact that some well-known classical proof techniques are forbidden by certain properties of a quantum environment. Interestingly, we can exploit some of the very same properties to the benefit of quantum cryptography. Thus, this work lies right at the heart of the conflict between highly potential effects but likewise rather demanding conditions in the quantum world.

  12. Lightweight Distance Bounding Protocol against Relay Attacks

    Science.gov (United States)

    Kim, Jin Seok; Cho, Kookrae; Yum, Dae Hyun; Hong, Sung Je; Lee, Pil Joong

    Traditional authentication protocols are based on cryptographic techniques to achieve identity verification. Distance bounding protocols are an enhanced type of authentication protocol built upon both signal traversal time measurement and cryptographic techniques to accomplish distance verification as well as identity verification. A distance bounding protocol is usually designed to defend against the relay attack and the distance fraud attack. As there are applications to which the distance fraud attack is not a serious threat, we propose a streamlined distance bounding protocol that focuses on the relay attack. The proposed protocol is more efficient than previous protocols and has a low false acceptance rate under the relay attack.

  13. Advanced transport protocols for space communications

    Science.gov (United States)

    Fang, Jian

    Satellite IP networks are characterized by high bit error rates, long propagation delays, low bandwidth feedback links, and persistent fades resulting from varying weather patterns. A new unicast transport protocol is designed to address all the above challenges. Two new algorithms, Jump Start and Quick Recovery, are presented to replace the traditional Slow Start algorithm and to recover rapidly from multiple segment losses within one window of data. The characteristics of satellite IP networks also distinguish satellite multicasting from multicasting in terrestrial wirelined networks. A reliable data multicast transport protocol, TCP-Peachtree, is proposed to solve the acknowledgment implosion and scalability problems in satellite IP networks. Developments in space technology are enabling the realization of deep space missions. The scientific data from these missions need to be delivered to the Earth successfully. To achieve this goal, the InterPlaNetary Internet is proposed as the Internet of the deep space planetary networks, which is characterized by extremely high propagation delays, high link errors, asymmetrical bandwidth, and blackouts. A reliable transport protocol, TP-Planet, is proposed for data traffic in the InterPlaNetary Internet. TP-Planet deploys rate-based additive-increase multiplicative-decrease (AIMD) congestion control and replaces the inefficient slow start algorithm with a novel Initial State algorithm that allows the capture of link resources in a very fast and controlled manner. A new congestion detection and control mechanism is developed and a Blackout State is incorporated into the protocol operation. Multimedia traffic is also one part of the aggregate traffic over InterPlaNetary Internet backbone links and it has additional requirements such as minimum bandwidth, smooth traffic, and error control. To address all the above challenges, RCP-Planet is proposed. RCP-Planet consists of two novel algorithms, i.e., Begin State and

  14. BioBlocks: Programming Protocols in Biology Made Easier.

    Science.gov (United States)

    Gupta, Vishal; Irimia, Jesús; Pau, Iván; Rodríguez-Patón, Alfonso

    2017-01-24

    The methods to execute biological experiments are evolving. Affordable fluid handling robots and on-demand biology enterprises are making automating entire experiments a reality. Automation offers the benefit of high-throughput experimentation, rapid prototyping, and improved reproducibility of results. However, learning to automate and codify experiments is a difficult task as it requires programming expertise. Here, we present a web-based visual development environment called BioBlocks for describing experimental protocols in biology. It is based on Google's Blockly and Scratch, and requires little or no experience in computer programming to automate the execution of experiments. The experiments can be specified, saved, modified, and shared between multiple users in an easy manner. BioBlocks is open-source and can be customized to execute protocols on local robotic platforms or remotely, that is, in the cloud. It aims to serve as a de facto open standard for programming protocols in Biology.

  15. The Kyoto protocol development; La viabilite du protocole de Kyoto

    Energy Technology Data Exchange (ETDEWEB)

    Cooper, R. [Harvard Univ., Barrow, AK (United States); Guesneris, R. [College de France, 75 - Paris (France)

    2002-04-01

    From the author R. Cooper point of view the Kyoto Protocol is a flawed concept. The reasons for dropping Kyoto are presented in this paper insisting that rejecting Kyoto not means to imply that global climate change is not a serious problem. After a presentation of the US policy facing the Climatic Change, some concluding propositions are proposed. (A.L.B.)

  16. Developing protocols for obstetric emergencies.

    Science.gov (United States)

    Roth, Cheryl K; Parfitt, Sheryl E; Hering, Sandra L; Dent, Sarah A

    2014-01-01

    There is potential for important steps to be missed in emergency situations, even in the presence of many health care team members. Developing a clear plan of response for common emergencies can ensure that no tasks are redundant or omitted, and can create a more controlled environment that promotes positive health outcomes. A multidisciplinary team was assembled in a large community hospital to create protocols that would help ensure optimum care and continuity of practice in cases of postpartum hemorrhage, shoulder dystocia, emergency cesarean surgical birth, eclamptic seizure and maternal code. Assignment of team roles and responsibilities led to the evolution of standardized protocols for each emergency situation.

  17. The Simplest Protocol for Oblivious Transfer

    DEFF Research Database (Denmark)

    Chou, Tung; Orlandi, Claudio

    2015-01-01

    Oblivious Transfer (OT) is the fundamental building block of cryptographic protocols. In this paper we describe the simplest and most efficient protocol for 1-out-of-n OT to date, which is obtained by tweaking the Diffie-Hellman key-exchange protocol. The protocol achieves UC-security against...... optimizations) is at least one order of magnitude faster than previous work. Category / Keywords: cryptographic protocols / Oblivious Transfer, UC Security, Elliptic Curves, Efficient Implementation...

  18. Carbon Nanotube–Purification and Sorting Protocols

    Directory of Open Access Journals (Sweden)

    Poornendu Chaturvedi

    2008-09-01

    Full Text Available Carbon nanotubes (CNTs have shown extraordinary mechanical, thermal, electrical, and electronic properties. Electronic properties of CNT are very sensitive to its diameter and chirality, making it metallicor semiconducting, depending upon its chiral vector. The extraordinary properties of CNTs have led to demonstration of several applications but commercial realisation of these devices require consistent qualityof CNTs, and these should be  free of any impurity. For development of electronic devices, CNTs should notjust be pure but also of similar length, diameter, and electronic behaviour. Such demanding requirements need development of elaborate purification and sorting protocols. In this paper,  a brief review of the existing technologies and the research done is presented.Defence Science Journal, 2008, 58(5, pp.591-599, DOI:http://dx.doi.org/10.14429/dsj.58.1694

  19. A Passive Testing Approach for Protocols in Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Xiaoping Che

    2015-11-01

    Full Text Available Smart systems are today increasingly developed with the number of wireless sensor devices drastically increasing. They are implemented within several contexts throughout our environment. Thus, sensed data transported in ubiquitous systems are important, and the way to carry them must be efficient and reliable. For that purpose, several routing protocols have been proposed for wireless sensor networks (WSN. However, one stage that is often neglected before their deployment is the conformance testing process, a crucial and challenging step. Compared to active testing techniques commonly used in wired networks, passive approaches are more suitable to the WSN environment. While some works propose to specify the protocol with state models or to analyze them with simulators and emulators, we here propose a logic-based approach for formally specifying some functional requirements of a novel WSN routing protocol. We provide an algorithm to evaluate these properties on collected protocol execution traces. Further, we demonstrate the efficiency and suitability of our approach by its application into common WSN functional properties, as well as specific ones designed from our own routing protocol. We provide relevant testing verdicts through a real indoor testbed and the implementation of our protocol. Furthermore, the flexibility, genericity and practicability of our approach have been proven by the experimental results.

  20. Prevention Of WormholeAttacks In Geographic Routing Protocol

    Directory of Open Access Journals (Sweden)

    E.Poornima,

    2011-01-01

    Full Text Available As mobile ad hoc network applications are deployed, security emerges as a central requirement..Position aided routing protocols can offer a significant performance increase over traditional ad hoc routing protocols. Boundary State Routing (BSR is a geographic routing protocol which routes the data using the location of the nodes. Geographic routing protocols are known to be particularly susceptible to attacks.. In this paper we present the possible attacks on BSR protocol. One of the most popular and serious attacks in ad hoc networks is wormhole attack in which two or more colluding attackers record packets at one location, and tunnel them to another location for a replay at that remote location. A wormhole attack is very powerful, and preventing the attack has proven to be very difficult. In this paper, we devise efficient methods to detect and avoid wormhole attacks in the BSR protocol. The first method namely Reverse Routing Scheme (RRS attempts to detect the intrusion action .The second technique namely Authentication of Nodes Scheme (ANS uses cryptographic concepts to detect and prevent wormhole attacks. It not only detects the fake route but also adopts preventive measures against action wormhole nodes from reappearing during routing. The proposed system is designed in Boundary state routing (BSRprotocol and analysis and simulations are performed in network simulator (NS-2.

  1. A Secure Wireless Routing Protocol Using Enhanced Chain Signatures

    CERN Document Server

    Saxena, Amitabh

    2009-01-01

    We propose a routing protocol for wireless networks. Wireless routing protocols allow hosts within a network to have some knowledge of the topology in order to know when to forward a packet (via broadcast) and when to drop it. Since a routing protocol forms the backbone of a network, it is a lucrative target for many attacks, all of which attempt to disrupt network traffic by corrupting routing tables of neighboring routers using false updates. Secure routing protocols designed for wired networks (such as S-BGP) are not scalable in an ad-hoc wireless environment because of two main drawbacks: (1) the need to maintain knowledge about all immediate neighbors (which requires a discovery protocol), and (2) the need to transmit the same update several times, one for each neighbor. Although information about neighbors is readily available in a fairly static and wired network, such information is often not updated or available in an ad-hoc wireless network with mobile devices. Our protocol is a variant of S-BGP call...

  2. From Active to Passive Progress in Testing Internet Routing Protocols

    Institute of Scientific and Technical Information of China (English)

    赵邑新; 吴建平; 尹霞

    2002-01-01

    Routing protocols play an important role in the Internet and the test requirements are running up. To test routing protocols more efficiently, several enhancing techniques are applied in the protocol integrated test system described in this paper. The Implementation Under Test is modeled as a black box with windows. The test system is endowed with multiple channels and multiple ports to test distributed protocols. The test suite and other related aspects are also extended. Meanwhile, the passive testing is introduced to test, analyze and manage routing protocols in the production field, which is able to perform the conformance test, the interoperability test and the performance test. The state machine of peer sessions is tested with the state synchronization algorithm, and the routing information manipulation and other operations are checked and analyzed with the methods like the topology analysis and the internal process simulation. With both the active testing and the passive testing, the routing protocol test is going further and more thoroughly and helps a lot in the development of routers.

  3. A Passive Testing Approach for Protocols in Wireless Sensor Networks.

    Science.gov (United States)

    Che, Xiaoping; Maag, Stephane; Tan, Hwee-Xian; Tan, Hwee-Pink; Zhou, Zhangbing

    2015-11-19

    Smart systems are today increasingly developed with the number of wireless sensor devices drastically increasing. They are implemented within several contexts throughout our environment. Thus, sensed data transported in ubiquitous systems are important, and the way to carry them must be efficient and reliable. For that purpose, several routing protocols have been proposed for wireless sensor networks (WSN). However, one stage that is often neglected before their deployment is the conformance testing process, a crucial and challenging step. Compared to active testing techniques commonly used in wired networks, passive approaches are more suitable to the WSN environment. While some works propose to specify the protocol with state models or to analyze them with simulators and emulators, we here propose a logic-based approach for formally specifying some functional requirements of a novel WSN routing protocol. We provide an algorithm to evaluate these properties on collected protocol execution traces. Further, we demonstrate the efficiency and suitability of our approach by its application into common WSN functional properties, as well as specific ones designed from our own routing protocol. We provide relevant testing verdicts through a real indoor testbed and the implementation of our protocol. Furthermore, the flexibility, genericity and practicability of our approach have been proven by the experimental results.

  4. Asbestos Induces Oxidative Stress and Activation of Nrf2 Signaling in Murine Macrophages: Chemopreventive Role of the Synthetic Lignan Secoisolariciresinol Diglucoside (LGM2605)

    OpenAIRE

    Pietrofesa, Ralph A; Anastasia Velalopoulou; Albelda, Steven M.; Melpo Christofidou-Solomidou

    2016-01-01

    The interaction of asbestos fibers with macrophages generates harmful reactive oxygen species (ROS) and subsequent oxidative cell damage that are key processes linked to malignancy. Secoisolariciresinol diglucoside (SDG) is a non-toxic, flaxseed-derived pluripotent compound that has antioxidant properties and may thus function as a chemopreventive agent for asbestos-induced mesothelioma. We thus evaluated synthetic SDG (LGM2605) in asbestos-exposed, elicited murine peritoneal macrophages as a...

  5. Chemopreventive efficacy of hesperidin against chemically induced nephrotoxicity and renal carcinogenesis via amelioration of oxidative stress and modulation of multiple molecular pathways.

    Science.gov (United States)

    Siddiqi, Aisha; Hasan, Syed Kazim; Nafees, Sana; Rashid, Summya; Saidullah, Bano; Sultana, Sarwat

    2015-12-01

    In the present study, chemopreventive efficacy of hesperidin was evaluated against ferric nitrilotriacetate (Fe-NTA) induced renal oxidative stress and carcinogenesis in wistar rats. Nephrotoxicity was induced by single intraperitoneal injection of Fe-NTA (9 mg Fe/kg b.wt). Renal cancer was initiated by the administration of N-nitrosodiethylamine (DEN 200mg/kg b.wt ip) and promoted by Fe-NTA (9 mg Fe/kg b.wt ip) twice weekly for 16 weeks. Efficacy of hesperidin against Fe-NTA-induced nephrotoxicity was assessed in terms of biochemical estimation of antioxidant enzyme activities viz. reduced renal GSH, glutathione peroxidase, glutathione reductase, glutathione-S-transferase, catalase, superoxide dismutase and renal toxicity markers (BUN, Creatinine, KIM-1). Administration of Fe-NTA significantly depleted antioxidant renal armory, enhanced renal lipid peroxidation as well as the levels of BUN, creatinine and KIM-1. However, simultaneous pretreatment of hesperidin restored their levels in a dose dependent manner. Expression of apoptotic markers caspase-3, caspase-9, bax, bcl-2 and proliferative marker PCNA along with inflammatory markers (NFκB, iNOS, TNF-α) were also analysed to assess the chemopreventive potential of hesperidin in two-stage renal carcinogenesis model. Hesperidin was found to induce caspase-3, caspase-9, bax expression and downregulate bcl-2, NFκB, iNOS, TNF-α, PCNA expression. Histopathological findings further revealed hesperidin's chemopreventive efficacy by restoring the renal morphology. Our results provide a powerful evidence suggesting hesperidin to be a potent chemopreventive agent against renal carcinogenesis possibly by virtue of its antioxidant properties and by modulation of multiple molecular pathways.

  6. Relationships between pulmonary micro-RNA and proteome profiles, systemic cytogenetic damage and lung tumors in cigarette smoke-exposed mice treated with chemopreventive agents.

    Science.gov (United States)

    Izzotti, Alberto; Balansky, Roumen; D'Agostini, Francesco; Longobardi, Mariagrazia; Cartiglia, Cristina; La Maestra, Sebastiano; Micale, Rosanna T; Camoirano, Anna; Ganchev, Gancho; Iltcheva, Marietta; Steele, Vernon E; De Flora, Silvio

    2013-10-01

    Assessing the correlation between molecular endpoints and cancer induction or prevention aims at validating the use of intermediate biomarkers. We previously developed murine models that are suitable to detect both the carcinogenicity of mainstream cigarette smoke (MCS) and the induction of molecular alterations. In this study, we used 931 Swiss mice in two parallel experiments and in a preliminary toxicity study. The chemopreventive agents included vorinostat, myo-inositol, bexarotene, pioglitazone and a combination of bexarotene and pioglitazone. Pulmonary micro-RNAs and proteins were evaluated by microarray analyses at 10 weeks of age in male and female mice, either unexposed or exposed to MCS since birth, and either untreated or receiving each one of the five chemopreventive regimens with the diet after weaning. At 4 months of age, the frequency of micronucleated normochromatic erythrocytes was evaluated. At 7 months, the lungs were subjected to standard histopathological analysis. The results showed that exposure to MCS significantly downregulated the expression of 79 of 694 lung micro-RNAs (11.4%) and upregulated 66 of 1164 proteins (5.7%). Administration of chemopreventive agents modulated the baseline micro-RNA and proteome profiles and reversed several MCS-induced alterations, with some intergender differences. The stronger protective effects were produced by the combination of bexarotene and pioglitazone, which also inhibited the MCS-induced clastogenic damage and the yield of malignant tumors. Pioglitazone alone increased the yield of lung adenomas. Thus, micro-RNAs, proteins, cytogenetic damage and lung tumors were closely related. The molecular biomarkers contributed to evaluate both protective and adverse effects of chemopreventive agents and highlighted the mechanisms involved.

  7. Feasibility, safety and effectiveness of combining home based malaria management and seasonal malaria chemoprevention in children less than 10 years in Senegal

    DEFF Research Database (Denmark)

    Tine, Roger C K; Ndour, Cheikh T; Faye, Babacar;

    2014-01-01

    Home-based management of malaria (HMM) may improve access to diagnostic testing and treatment with artemisinin combination therapy (ACT). In the Sahel region, seasonal malaria chemoprevention (SMC) is now recommended for the prevention of malaria in children. It is likely that combinations of ant...... of antimalarial interventions can reduce the malaria burden. This study assessed the feasibility, effectiveness and safety of combining SMC and HMM delivered by community health workers (CHWs)....

  8. Probability Distributions over Cryptographic Protocols

    Science.gov (United States)

    2009-06-01

    exception. Cryptyc integrates use of pattern- matching in the spi calculus framework , which in turn allows the specification of nested cryptographic...programs too: the metaheuristic search for security protocols,” Information and Software Technology, vol. 43, pp. 891– 904, December 2001. 131 [9] X

  9. Performance Evaluation of Security Protocols

    DEFF Research Database (Denmark)

    Bodei, Chiara; Buchholtz, Mikael; Curti, Michele

    2005-01-01

    We use a special operational semantics which drives us in inferring quantitative measures on systems describing cryptographis cryptographic protocols. We assign rates to transitions by only looking at these labels. The rates reflect the distributed architecture running applications and the use of...... of possibly different cryptosystems. We then map transition systems to Markov chains and evaluate performance of systems, using standard tools....

  10. A Student Teamwork Induction Protocol

    Science.gov (United States)

    Kamau, Caroline; Spong, Abigail

    2015-01-01

    Faulty group processes have harmful effects on performance but there is little research about intervention protocols to pre-empt them in higher education. This naturalistic experiment compared a control cohort with an inducted cohort. The inducted cohort attended a workshop, consultations, elected a leader and used tools (a group log and group…

  11. Metabolomics protocols for filamentous fungi.

    Science.gov (United States)

    Gummer, Joel P A; Krill, Christian; Du Fall, Lauren; Waters, Ormonde D C; Trengove, Robert D; Oliver, Richard P; Solomon, Peter S

    2012-01-01

    Proteomics and transcriptomics are established functional genomics tools commonly used to study filamentous fungi. Metabolomics has recently emerged as another option to complement existing techniques and provide detailed information on metabolic regulation and secondary metabolism. Here, we describe broad generic protocols that can be used to undertake metabolomics studies in filamentous fungi.

  12. From protocol to published report

    DEFF Research Database (Denmark)

    Berendt, Louise; Callréus, Torbjörn; Petersen, Lene Grejs

    2016-01-01

    BACKGROUND: Unacknowledged inconsistencies in the reporting of clinical trials undermine the validity of the results of the trials. Little is known about inconsistency in the reporting of academic clinical drug trials. Therefore, we investigated the prevalence of consistency between protocols and...

  13. Protocol biopsies for renal transplantation

    Directory of Open Access Journals (Sweden)

    Rush David

    2010-01-01

    Full Text Available Protocol biopsies in renal transplantation are those that are procured at predetermined times post renal transplantation, regardless of renal function. These biopsies have been useful to study the natural history of the transplanted kidney as they have detected unexpected - i.e. "subclinical" pathology. The most significant subclinical pathologies that have been detected with protocol biopsies have been acute lesions, such as cellular and antibody mediated rejection, and chronic lesions, such as interstitial fibrosis and tubular atrophy, and transplant glomerulopathy. The potential benefit of early recognition of the above lesions is that their early treatment may result in improved long-term outcomes. Conversely, the identification of normal histology on a protocol biopsy, may inform us about the safety of reduction in overall immunosuppression. Our centre, as well as others, is attempting to develop non-invasive methods of immune monitoring of renal transplant patients. However, we believe that until such methods have been developed and validated, the protocol biopsy will remain an indispensable tool for the complete care of renal transplant patients.

  14. Petri Nets in Cryptographic Protocols

    DEFF Research Database (Denmark)

    Crazzolara, Federico; Winskel, Glynn

    2001-01-01

    A process language for security protocols is presented together with a semantics in terms of sets of events. The denotation of process is a set of events, and as each event specifies a set of pre and postconditions, this denotation can be viewed as a Petri net. By means of an example we illustrat...

  15. Recursive Ping-Pong Protocols

    DEFF Research Database (Denmark)

    Huttel, Hans; Srba, Jiri

    2004-01-01

    This paper introduces a process calculus with recursion which allows us to express an unbounded number of runs of the ping-pong protocols introduced by Dolev and Yao. We study the decidability issues associated with two common approaches to checking security properties, namely reachability analys...

  16. Automata-theoretic protocol programming

    NARCIS (Netherlands)

    Jongmans, Sung-Shik Theodorus Quirinus

    2016-01-01

    Parallel programming has become essential for writing scalable programs on general hardware. Conceptually, every parallel program consists of workers, which implement primary units of sequential computation, and protocols, which implement the rules of interaction that workers must abide by. As progr

  17. Bundle Security Protocol for ION

    Science.gov (United States)

    Burleigh, Scott C.; Birrane, Edward J.; Krupiarz, Christopher

    2011-01-01

    This software implements bundle authentication, conforming to the Delay-Tolerant Networking (DTN) Internet Draft on Bundle Security Protocol (BSP), for the Interplanetary Overlay Network (ION) implementation of DTN. This is the only implementation of BSP that is integrated with ION.

  18. The Kyoto Protocol and China

    Institute of Scientific and Technical Information of China (English)

    佘巧云

    2005-01-01

    The kyoto Protocol is an agreement to the United Nations Framework Convention on CLimate Change (UNFCCC)2,an international treaty on global warming .It is a legally binding agreement under which industrialized countries will reduce their collective emissions of greenhouse gases by an average of 5.2% compared to the level of 1990 during the 2008-12 period.

  19. Formally Generating Adaptive Security Protocols

    Science.gov (United States)

    2013-03-01

    a proven version of leader election and 2/3 consensus. In 2011 we did the same for a simple version of Paxos. At each stage of the evolution as our... leader election [2] and authentication [4] would suffice for Paxos as well. In preparation for the harder protocols, we had added expressive power to the

  20. Spectroscopic characterization of lycopene extract from Lycopersicum esculentum (Tomato) and its evaluation as a chemopreventive agent against experimental hepatocarcinogenesis in mice.

    Science.gov (United States)

    Gupta, Prachi; Bansal, Mohinder Pal; Koul, Ashwani

    2013-03-01

    The present study was designed to characterize the lycopene extract (LycT) prepared from tomatoes (Lycopersicum esculentum) and then to evaluate its chemopreventive efficacy in N-diethylnitrosamine (NDEA)-induced experimental hepatocarcinogenesis in female Balb/c mice. The extraction of lycopene was carried out using hexane/acetone/ethanol as an extracting medium and then characterized by ultraviolet-visible, nuclear magnetic resonance and Fourier transform infrared spectroscopy. Chemopreventive efficacy of characterized LycT in vivo was evaluated in terms of hepatic tumour incidence, multiplicity, burden, hepatosomatic index and animal survival rate. Results indicated that average lycopene content of the tomato was 11.6-14 mg/kg tomato weight. Spectroscopic data confirmed the structural characteristics of lycopene in the extract. In the animal study, reduction in tumour incidence (42.05%), tumour burden (1.39) and tumour multiplicity (3.42) was observed upon LycT pretreatment to NDEA-treated animals. Histopathological analysis unravelled that the increased survival rate in LycT + NDEA-treated animals was due to the delay in the formation of aggressive tumour nodules. These observations indicate that lycopene seems to be an able candidate for chemoprevention in hepatocarcinogenesis resulting from NDEA insults.

  1. Quantum Key Distribution Using Decoy State Protocol

    Directory of Open Access Journals (Sweden)

    Sellami Ali

    2009-01-01

    Full Text Available Problem statement: Quantum key distribution provides unconditional security guaranteed by the fundamental laws of quantum physics. Unfortunately, for real-life experimental set-ups, which mainly based on faint laser pulses, the occasional production of multi-photons and channel loss make it possible for sophisticated eavesdroppers to launch various subtle eavesdropping attacks including the Photon Number Splitting (PNS attack. The decoy state protocols recently proposed to beat PNS attack and to improve dramatically distance and secure key generation rate of Quantum Key Distribution (QKD. Approach: Objective of this study was experimental implementation of weak decoy + vacuum states QKD for increasing the performance of QKD system. To show conceptually how simple it was to apply the weak decoy + vacuum state idea to a commercial QKD system, we chosen ID-3000 commercial quantum key distribution system manufactured by id quantique. To implement the weak decoy + vacuum state protocol, we had to add some new optical and electronics components to id quantique and to attenuate each signal to the intensity of either signal state or weak decoy or vacuum state randomly. Results: In our implementation, the attenuation will be done by placing a VOA (variable optical attenuator in Alice’s side. Specifically, our QKD system required the polarizations of 2 pulses from the same signal to be orthogonal. Therefore the VOA must be polarization independent so as to attenuate the two pulses equally. The VOA utilized in experiment to attenuate signals dynamically was Intensity Modulator (IM. We had implemented weak + vacuum protocol on a modified commercial QKD system over a 25 km of telecom fibers with an unconditionally secure key rate of 6.2931x10-4 per pulse. Conclusion: By making simple modifications to a commercial quantum key distribution system, we could achieve much better performance with substantially higher key generation rate and longer distance than

  2. Performance Evaluation of MANET Routing Protocols Based on Internet Protocols

    Directory of Open Access Journals (Sweden)

    Hilal Bello Said,

    2015-11-01

    Full Text Available The topology of mobile ad hoc network (MANET changes rapidly and unpredictably due to nodes mobility. This makes routing protocols very important to analyze so as to communicate efficiently between the wireless nodes. Another important issue in the MANET is the internet protocols IPv4 and IPV6. The former which have been conventionally in use for long and the latter which is seen as the future standard for network architecture is studied due to its improved protection and huge address space support. In this paper, performance of AODV, DYMO, OLSRv2 and OLSR are analyzed under the IPv4 and IPv6 standards using the Qualnet simulator. Distinct performance metrics viz. Packet delivery ratio, Throughput, Average End-to-End Delay, and Average jitter are selected for the experiment. The results are then analyzed and scrutinized to provide qualitative assessment of their performances.

  3. Novel analysis and improvement of Yahalom protocol

    Institute of Scientific and Technical Information of China (English)

    CHEN Chun-ling; YU Han; L(U) Heng-shan; WANG Ru-chuan

    2009-01-01

    The modified version of Yahalom protocol improved by Burrows, Abradi, and Needham (BAN) still has security drawbacks. This study analyzed such flaws in a detailed way from the point of strand spaces, which is a novel method of analyzing protocol's security. First, a mathematical model of BAN-Yahalom protocol is constructed. Second, penetrators' abilities are restricted with a rigorous and formalized definition. Moreover, to increase the security of this protocol against potential attackers in practice, a further improvement is made to the protocol. Future application of this re-improved protocol is also discussed.

  4. A multi-protocol architecture for SNMP entities

    OpenAIRE

    Lopes, Rui Pedro; Oliveira, José Luís

    2002-01-01

    Crescent requirements on the network management area, droved by the successive increase on networks size, internetworking complexity and time-constraint services deployment, impose the omnipresence of technicians and tools. The universality of the interfaces, both for the manager and for the agent sides, is essential to support these requirements. This paper presents a middleware architecture for the development of agents that can be transparently mapped into different management protocol sta...

  5. Development of high-reliable real-time communication network protocol for SMART

    Energy Technology Data Exchange (ETDEWEB)

    Song, Ki Sang; Kim, Young Sik [Korea National University of Education, Chongwon (Korea); No, Hee Chon [Korea Advanced Institute of Science and Technology, Taejon (Korea)

    1999-04-01

    In this research, we first define protocol subsets for SMART(System-integrated Modular Advanced Reactor) communication network based on the requirement of SMART MMIS transmission delay and traffic requirements and OSI(Open System Interconnection) 7 layers' network protocol functions. Also, current industrial purpose LAN protocols are analyzed and the applicability of commercialized protocols are checked. For the suitability test, we have applied approximated SMART data traffic and maximum allowable transmission delay requirement. With the simulation results, we conclude that IEEE 802.5 and FDDI which is an ANSI standard, is the most suitable for SMART. We further analyzed the FDDI and token ring protocols for SMART and nuclear plant network environment including IEEE 802.4, IEEE 802.5, and ARCnet. The most suitable protocol for SMART is FDDI and FDDI MAC and RMT protocol specifications have been verified with LOTOS and the verification results show that FDDI MAC and RMT satisfy the reachability and liveness, but does not show deadlock and livelock. Therefore, we conclude that FDDI MAC and RMT is highly reliable protocol for SMART MMIS network. After that, we consider the stacking fault of IEEE 802.5 token ring protocol and propose a fault tolerant MAM(Modified Active Monitor) protocol. The simulation results show that the MAM protocol improves lower priority traffic service rate when stacking fault occurs. Therefore, proposed MAM protocol can be applied to SMART communication network for high reliability and hard real-time communication purpose in data acquisition and inter channel network. (author). 37 refs., 79 figs., 39 tabs.

  6. QoS-aware self-adaptation of communication protocols in a pervasive service middleware

    DEFF Research Database (Denmark)

    Zhang, Weishan; Hansen, Klaus Marius; Fernandes, João;

    2010-01-01

    Pervasive computing is characterized by heterogeneous devices that usually have scarce resources requiring optimized usage. These devices may use different communication protocols which can be switched at runtime. As different communication protocols have different quality of service (QoS) proper...

  7. Optimization and verification of the TR-MAC protocol for wireless sensor networks

    NARCIS (Netherlands)

    Morshed, Sarwar; Heijenk, Geert

    2015-01-01

    Energy-efficiency is an important requirement in the design of communication protocols for wireless sensor networks (WSN). TR-MAC is an energy-efficient medium access control (MAC) layer protocol for low power WSN that exploits transmitted-reference (TR) modulation in the physical layer. The underly

  8. Protocol for Quantification of Defects in Natural Fibres for Composites

    DEFF Research Database (Denmark)

    Mortensen, Ulrich Andreas; Madsen, Bo

    2014-01-01

    Natural bast-type plant fibres are attracting increasing interest for being used for structural composite applications where high quality fibres with good mechanical properties are required. A protocol for the quantification of defects in natural fibres is presented. The protocol is based...... of defect size by width, and it is shown that both definitions can be used to give unbiased findings for the comparison between fibre types. Finally, considerations are given with respect to true measures of defect content, number of determinations, and number of significant figures used for the descriptive...

  9. Security protocol specification and verification with AnBx

    DEFF Research Database (Denmark)

    Bugliesi, Michele; Calzavara, Stefano; Mödersheim, Sebastian Alexander

    2016-01-01

    Designing distributed protocols is complex and requires actions at very different levels: from the design of an interaction flow supporting the desired application-specific guarantees to the selection of the most appropriate network-level protection mechanisms. To tame this complexity, we propose...... AnBx, a formal protocol specification language based on the popular Alice & Bob notation. AnBx offers channels as the main abstraction for communication, providing different authenticity and/or confidentiality guarantees for message transmission. AnBx extends existing proposals in the literature...

  10. Efficient medium access control protocol for geostationary satellite systems

    Institute of Scientific and Technical Information of China (English)

    王丽娜; 顾学迈

    2004-01-01

    This paper proposes an efficient medium access control (MAC) protocol based on multifrequency-time division multiple access (MF-TDMA) for geostationary satellite systems deploying multiple spot-beams and onboard processing,which uses a method of random reservation access with movable boundaries to dynamically request the transmission slots and can transmit different types of traffic. The simulation results have shown that our designed MAC protocol can achieve a high bandwidth utilization, while providing the required quality of service (QoS) for each class of service.

  11. SECURING VIRTUAL IMAGES USING BLIND AUTHENTICATION PROTOCOL

    Directory of Open Access Journals (Sweden)

    RAVIKIRAN PEELUKHANA,

    2011-04-01

    Full Text Available The cloud virtualization technology improves the economy of scale for data centers through server consolidation, application consolidation and resources consolidation. Virtualization allows the provider to move Virtual Images from more congested host to less-congested hosts, as required. Enterprises also get improved server reliability, which in turn increases application performance. Despite these benefits, it includes major security challenges with the portability of Virtual Images between different cloud providers.The security and integrity of Virtual images is the foundation for the overall security of the cloud. Many of the Virtual images are intended to be shared by diverse and unrelated users. Unfortunately, existing approaches to cloud security built by cloud practitioners fall short when dealing with Virtual images. Secure transmission of virtual Images can bepossible by providing authentication using Blind Authentication protocol (BAP. The proposed approach authenticates the allocation of virtual images using Blind authentication protocol. It provides provable protection against replay and client side attacks even if the keys of the user are compromised. The encryption also provides template protection, revocability and alleviates the concerns on privacy in widespread use of biometrics. Carrying out the authentication in the encrypted domain is a secure process, while the encryption key acts as an additional layer of security.

  12. [The protocol for multi organ donor management].

    Science.gov (United States)

    Kucewicz, Ewa; Wojarski, Jacek; Zegleń, Sławomir; Saucha, Wojciech; Maciejewski, Tomasz; Pacholewicz, Jerzy; Przybylski, Roman; Knapik, Piotr; Zembala, Marian

    2009-01-01

    Identification and preparation of a potential organ donor requires careful and meticulous intensive care, so that the organs may be harvested in the best possible condition for transplantation. The protocol consists of three key elements: (1) monitoring and haemodynamicstabilisation, (2) hormonal therapy, and (3) adequate mechanical ventilation and nosocomial pneumonia prophylaxis. Standard haemodynamic monitoring should consist of a 12 lead EGG, and direct monitoring of arterial and central venous pressures. Pulmonary artery catheterisation is indicated in donors with a left ventricular ejection fraction (LVEF) below 45%. PCWP should be kept at around 12 mm Hg, Cl at greater than 2.4 L m(-2), and SVR between 800 and 1200 dyn s(-1) cm(-5). When a vasopressor is necessary, vasopressin should be used as the drug of choice. If vasopressin is not available, noradrenaline or adrenaline may be used. Haemoglobin concentration should be maintained between 5.5-6.2 mmol L(-1). In a potential heart donor, troponin concentration should be checked daily. Neutral thermal conditions should be maintained using a warm air blower. A brain dead patient cannot maintain adequate pituitary function, therefore hormone replacement therapy with methylprednisolone, thyroxin and desmopressin is indicated. Glucose concentrations should be kept within the normal range, using insulin if necessary. The lung harvesting protocol should be similarto ARDS treatment guidelines (optimal PEEP, low tidal volumes). Lung recruitment manoeuvres, and aggressive prevention and treatment of nosocomial infection are essential.

  13. Implementation and evaluation of a protocol management system for automated review of CT protocols.

    Science.gov (United States)

    Grimes, Joshua; Leng, Shuai; Zhang, Yi; Vrieze, Thomas; McCollough, Cynthia

    2016-09-08

    Protocol review is important to decrease the risk of patient injury and increase the consistency of CT image quality. A large volume of CT protocols makes manual review labor-intensive, error-prone, and costly. To address these challenges, we have developed a software system for automatically managing and monitoring CT proto-cols on a frequent basis. This article describes our experiences in the implementation and evaluation of this protocol monitoring system. In particular, we discuss various strategies for addressing each of the steps in our protocol-monitoring workflow, which are: maintaining an accurate set of master protocols, retrieving protocols from the scanners, comparing scanner protocols to master protocols, reviewing flagged differences between the scanner and master protocols, and updating the scanner and/or master protocols. In our initial evaluation focusing only on abdo-men and pelvis protocols, we detected 309 modified protocols in a 24-week trial period. About one-quarter of these modified protocols were determined to contain inappropriate (i.e., erroneous) protocol parameter modifications that needed to be corrected on the scanner. The most frequently affected parameter was the series description, which was inappropriately modified 47 times. Two inappropriate modifications were made to the tube current, which is particularly important to flag as this parameter impacts both radiation dose and image quality. The CT protocol changes detected in this work provide strong motivation for the use of an automated CT protocol quality control system to ensure protocol accuracy and consistency.

  14. Perfect forward secure identity-based authenticated key agreement protocol in the escrow mode

    Institute of Scientific and Technical Information of China (English)

    WANG ShengBao; CAO ZhenFu; CHENG ZhaoHui; CHOO Kim-KwangRaymond

    2009-01-01

    The majority of existing escrowable identity-based key agreement protocols only provide partial forward secrecy. Such protocols are, arguably, not suitable for many real-word applications, as the latter tends to require a stronger sense of forward secrecy-perfect forward secrecy. In this paper, we propose an efficient perfect forward-secure identity-based key agreement protocol in the escrow mode. We prove the security of our protocol in the random oracle model, assuming the intractability of the Gap Bilinear Diffie-Hellman (GBDH) problem.

  15. Serial extraction protocol for partial arches in implant dentistry: principles and clinical methodology.

    Science.gov (United States)

    Cavallaro, John S; Greenstein, Gary; Greenstein, Ben

    2010-01-01

    Serial extraction protocol (SEP) is a clinical technique that facilitates using natural tooth abutments to support a fixed interim resin prosthesis, while inserting a sufficient number of implants to retain a definitive fixed prosthesis. A Class 1 protocol allows all necessary implants to be placed during one surgical appointment, while a Class 2 protocol requires two or more rounds of implant installation to achieve sufficient support for a definitive fixed prosthesis. The SEP methodology can be used to restore full and partially edentulous dentitions. This article addresses rehabilitation of partial arches using an SEP protocol.

  16. Ada-MAC: An Adaptive MAC Protocol for Real-time and Reliable Health Monitoring,

    OpenAIRE

    Xia, Feng; Wang, Linqiang; Zhang, Daqiang; Zhang, Xue(Department of Physics, Liaoning Normal University, Dalian, 116029, China); Gao, Ruixia

    2013-01-01

    IEEE 802.15.4 is regarded as one of the most suitable communication protocols for cyber-physical applications of wireless sensor and actuator networks. This is because this protocol is able to achieve low-power and low-cost transmission in wireless personal area networks. But most cyber-physical systems (CPSs) require a degree of real-time and reliability from the underlying communication protocol. Some of them are stricter than the others. However, IEEE 802.15.4 protocol cannot provide relia...

  17. Efficient Authenticated Key Agreement Protocol Using Self-Certified Public Keys from Pairings

    Institute of Scientific and Technical Information of China (English)

    SHAO Zu-hua

    2005-01-01

    An efficient authenticated key agreement protocol is proposed, which makes use of bilinear pairings and selfcertified public keys. Its security is based on the security assumptions of the bilinear Diffie-Hellman problem and the computational Diffie-Hellman problem. Users can choose their private keys independently. The public keys and identities of users can be verified implicitly when the session key being generating in a logically single step. A trusted Key Generation Center is no longer required as in the ID-based authenticated key agreement protocols. Compared with existing authenticated key agreement protocols from pairings, the new proposed protocol is more efficient and secure.

  18. Distal bowel selectivity in the chemoprevention of experimental colon carcinogenesis by the non-steroidal anti-inflammatory drug nabumetone.

    Science.gov (United States)

    Roy, H K; Karolski, W J; Ratashak, A

    2001-05-15

    Use of non-steroidal anti-inflammatory drugs (NSAIDs) for chemoprevention of colon cancer has been hindered by their potential gastro-intestinal toxicity. Nabumetone, which is approximately 10 to 36 times safer than conventional NSAIDs, was evaluated in 2 models of experimental colon carcinogenesis. In azoxymethane (AOM)-treated Fisher 344 rats, nabumetone caused dose-dependent inhibition of aberrant crypt foci (ACF), with 750 and 1,500 ppm resulting in 15% and 37% reductions, respectively (p nabumetone, with 900 ppm suppressing approximately half of the intestinal tumors. Interestingly, inhibition of intermediate biomarkers in both models was markedly greater in the distal than the proximal bowel. To mechanistically evaluate this regional selectivity, we assessed cyclo-oxygenase-2 (COX-2) expression in the uninvolved mucosa and demonstrated a 3- to 4-fold excess in the distal relative to the proximal bowel in both MIN mice and AOM-treated rats. We then investigated another putative NSAID target, peroxisome proliferator-activated receptor-delta (PPAR-delta) and demonstrated up-regulation during AOM-induced colonic tumorigenesis. Furthermore, in pre-neoplastic mucosa, there was a 3-fold excess of PPAR-delta in the distal colon. We demonstrate that nabumetone is an effective protective agent in both experimental models of colon carcinogenesis. The striking distal predilection of nabumetone may be, at least partially, explained by distal bowel over-expression of COX-2 and PPAR-delta.

  19. Zileuton, 5-lipoxygenase inhibitor, acts as a chemopreventive agent in intestinal polyposis, by modulating polyp and systemic inflammation.

    Directory of Open Access Journals (Sweden)

    Elias Gounaris

    Full Text Available Leukotrienes and prostaglandins, products of arachidonic acid metabolism, sustain both systemic and lesion-localized inflammation. Tumor-associated Inflammation can also contribute to the pathogenesis of colon cancer. Patients with inflammatory bowel disease (IBD have increased risk of developing colon cancer. The levels of 5-lipoxygenase (5-LO, the key enzyme for leukotrienes production, are increased in colon cancer specimens and colonic dysplastic lesions. Here we report that Zileuton, a specific 5-LO inhibitor, can prevent polyp formation by efficiently reducing the tumor-associated and systemic inflammation in APCΔ468 mice.In the current study, we inhibited 5-LO by dietary administration of Zileuton in the APCΔ468 mouse model of polyposis and analyzed the effect of in vivo 5-LO inhibition on tumor-associated and systemic inflammation.Zileuton-fed mice developed fewer polyps and displayed marked reduction in systemic and polyp-associated inflammation. Pro-inflammatory cytokines and pro-inflammatory innate and adaptive immunity cells were reduced both in the lesions and systemically. As part of tumor-associated inflammation Leukotriene B4 (LTB4, product of 5-LO activity, is increased focally in human dysplastic lesions. The 5-LO enzymatic activity was reduced in the serum of Zileuton treated polyposis mice.This study demonstrates that dietary administration of 5-LO specific inhibitor in the polyposis mouse model decreases polyp burden, and suggests that Zileuton may be a potential chemo-preventive agent in patients that are high-risk of developing colon cancer.

  20. Chemopreventive action of non-steroidal anti-inflammatory drugs on the inflammatory pathways in colon cancer.

    Science.gov (United States)

    Ghanghas, Preety; Jain, Shelly; Rana, Chandan; Sanyal, S N

    2016-03-01

    Non-steroidal anti-inflammatory drugs (NSAIDs) are emerging as novel chemopreventive agents against a variety of cancers owing to their capability in blocking the tumor development by cellular proliferation and by promoting apoptosis. Inflammation is principal cause of colon carcinogenesis. A missing link between inflammation and cancer could be the activation of NF-κB, which is a hallmark of inflammatory response, and is commonly detected in malignant tumors. Therefore, targeting pro-inflammatory cyclooxygenase enzymes and transcription factors will be profitable as a mechanism to inhibit tumor growth. In the present study, we have studied the role of various pro-inflammatory enzymes and transcription factors in the development of the 1,2-dimethylhydrazine dihydrochloride (DMH)-induced colorectal cancer and also observed the role of three NSAIDs, viz., Celecoxib, Etoricoxib and Diclofenac. Carcinogenic changes were observed in morphological and histopathological studies, whereas protein regulations of various biomolecules were identified by immunofluorescence analysis. Apoptotic studies was done by TUNEL assay and Hoechst/PI co-staining of the isolated colonocytes. It was found that DMH-treated animals were having an over-expression of pro-inflammatory enzymes, aberrant nuclear localization of activated cell survival transcription factor, NF-κB and suppression of anti-inflammatory transcription factor PPAR-γ, thereby suggesting a marked role of inflammation in the tumor progression. However, co-administration of NSAIDs has significantly reduced the inflammatory potential of the growing neoplasm.

  1. Target delivery and controlled release of the chemopreventive drug sulindac by using an advanced layered double hydroxide nanomatrix formulation system.

    Science.gov (United States)

    Minagawa, Keiji; Berber, Mohamed R; Hafez, Inas H; Mori, Takeshi; Tanaka, Masami

    2012-04-01

    Target delivery and controlled release of the chemopreventive drug sulindac that possesses low water solubility present a great challenge for its pharmaceutical industry. Here, we offered an advanced nanomatrix formulation system of sulindac based on layered double hydroxide materials. The X-ray analysis and infrared spectroscopy confirmed the incorporation of sulindac into the gallery of the layered double hydroxides. The incorporation ratios of sulindac were recorded to be 45, 31 and 20 for coprecipitation, anion-exchange and reconstruction techniques, respectively. The scanning electron microscopy showed a nanomatrix-structure of ~50 nm. The release studies of sulindac-nanomatrix showed a 96% controlled release at the small intestine solution during 3 h(s), indicating an enhancement in the dissolution profile of sulindac after the matrix formation. The layered structure of the matrix supplied sulindac with a well-ordered structure and a relatively hydrophobic microenvironment that controlled the guest hydrolysis and reactivity during the release process. The laminar structure of layered double hydroxides offered a safe preservation for sulindac against photodecarboxylation, and enhanced the drug thermal stability from 190 to 230° C. The ionic electrostatic interaction of sulindac through its acidic group with layered double hydroxides demolished the gastrointestinal ulceration.

  2. Chemopreventive potential of fungal taxol against 7, 12-dimethylbenz[a]anthracene induced mammary gland carcinogenesis in Sprague Dawley rats.

    Science.gov (United States)

    Gokul Raj, Kathamuthu; Chidambaram, Ranganathan; Varunkumar, Krishnamoorthy; Ravikumar, Vilwanathan; Pandi, Mohan

    2015-11-15

    Breast cancer is the second most prevalent cancer and foremost global public health problem. The present study was designed to appraise the chemopreventive potential of fungal taxol against 7,12-dimethylbenz[a]anthracene (DMBA) induced mammary gland carcinogenesis in Sprague Dawley rats. After 90 days of tumor induction, fungal and authentic taxol were given intraperitoneally once in a week for four weeks. Infrared thermal imaging analysis, serum biochemical parameters such as lipid peroxidase (LPO), creatinine, enzymic and non enzymic antioxidants, liver markers tests such as alanine transaminase (ALT), aspartate aminotransferase (AST), total cholesterol (TC), triglycerides (TG) and lipoproteins was analysed. In addition, histopathological observation (breast, kidney and liver), immunohistochemical analysis (p53 and Her2/neu) and western blotting experiments (bcl-2, bax and caspase-9) were performed both in control and experimental animals. In thermal imaging, decreased temperature was observed in rat treated with fungal and authentic taxol when compared to tumor induced rats. The significant decrease in LPO, creatinine, ALT, AST, TC, TG, lipoproteins and increase in enzymic, non-enzymic antioxidants were exemplified in serum of treated groups. Further histopathology, immunohistochemical and western blot analysis (bax, cas-9 and bcl-2) of apoptotic markers in breast tissues clearly showed the anti-carcinogenic property of fungal taxol. Our findings implement that fungal taxol is a potential chemo preventive agent against DMBA induced mammary gland carcinogenesis.

  3. Cancer chemoprevention by an adenosine derivative in a model of cirrhosis-hepatocellular carcinoma induced by diethylnitrosamine in rats.

    Science.gov (United States)

    Velasco-Loyden, Gabriela; Pérez-Martínez, Lidia; Vidrio-Gómez, Susana; Pérez-Carreón, Julio Isael; Chagoya de Sánchez, Victoria

    2017-02-01

    Hepatocellular carcinoma is one of the most common cancers, and approximately 80% develop from cirrhotic livers. We have previously shown that the aspartate salt of adenosine prevents and reverses carbon tetrachloride-induced liver fibrosis in rats. Considering the hepatoprotective role of this adenosine derivative in fibrogenesis, we were interested in evaluating its effect in a hepatocarcinogenesis model induced by diethylnitrosamine in rats, where multinodular cancer is preceded by cirrhosis. Rats were injected with diethylnitrosamine for 12 weeks to induce cirrhosis and for 16 weeks to induce hepatocarcinogenesis. Groups of rats were treated with aspartate salt of adenosine from the beginning of carcinogen administration for 12 or 18 weeks total, and another group received the compound from weeks 12 to 18. Fibrogenesis was estimated and the proportion of preneoplastic nodules and tumors was measured. The apoptotic and proliferation rates in liver tissues were evaluated, as well as the expression of cell signaling and cell cycle proteins participating in hepatocarcinogenesis. The adenosine derivative treatment reduced diethylnitrosamine-induced collagen expression and decreased the proportion of nodules positive for the tumor marker γ-glutamyl transferase. This compound down-regulated the expression of thymidylate synthase and hepatocyte growth factor, and augmented the protein level of the cell cycle inhibitor p27; these effects could be part of its chemopreventive mechanism. These findings suggest a hepatoprotective role of aspartate salt of adenosine that could be used as a therapeutic compound in the prevention of liver tumorigenesis as described earlier for hepatic fibrosis.

  4. Use of the disulfiram/copper complex for breast cancer chemoprevention in MMTV-erbB2 transgenic mice.

    Science.gov (United States)

    Yang, Yanhui; Deng, Qian; Feng, Xiaoshan; Sun, Junjun

    2015-07-01

    The disulfiram/copper complex (DS/Cu) has been demonstrated to exert potent anti-tumor effects in various types of cancer. At present, whether DS/Cu has chemopreventive effects on breast cancer development remains to be fully elucidated. In the present study, using MMTV-erbB2 transgenic mice, it was identified for the first time that DS/Cu treatment was able to inhibit cell growth in breast cancer cells while sparing normal cells in vitro, in addition to delaying the development of mammary tumor development in MMTV-erbB2 transgenic mice in vivo. Morphological examination demonstrated that DS/Cu treatment resulted in cell proliferation inhibition and apoptosis activation in vitro and in vivo. Furthermore, the present study observed that DS/Cu may inhibit proliferation via inhibition of AKT and cyclin D1 signaling and promote apoptosis via c-Jun N-terminal kinase activation and suppression of nuclear factor κB signaling. These results suggested that DS/Cu treatment may be a promising therapy for the prevention of erbB2-positive breast cancer.

  5. Chemopreventive effects of synthetic C-substituted diindolylmethanes originating from cruciferous vegetables in human oral cancer cells.

    Science.gov (United States)

    Shin, Ji-Ae; Shim, Jung-Hyun; Choi, Eun-Sun; Leem, Dae-Ho; Kwon, Ki Han; Lee, Syng-Ook; Safe, Stephen; Cho, Nam-Pyo; Cho, Sung-Dae

    2011-09-01

    Diindolylmethane (DIM), an isothiocyanate found in cruciferous vegetables, has been shown to have cancer chemopreventive effects. A series of synthetic C-substituted DIMs (C-DIMs) analogs was developed, including DIM-C-pPhtBu and DIM-C-pPhC6H5, which exhibited better inhibitory activity in cancer cells than DIM. This study examined the effects of C-DIMs on the growth of human oral cancer cells. DIM-C-pPhtBu and DIM-C-pPhC6H5 decreased the number of viable KB cells and induced caspase-dependent apoptosis. The apoptotic cell death was accompanied by a change in Bax/Bcl-2 ratio and damage to mitochondrial membrane potential through the induction of death receptor 5 and the cleavage of Bid and caspase 8. Studies on the mechanism of action showed that the apoptotic cell death induced by DIM-C-pPhtBu and DIM-C-pPhC6H5 was mediated by endoplasmic reticulum stress. In addition, C-DIMs inhibited cell proliferation and induced PARP cleavage through death receptor 5 and CHOP in HEp-2 and HN22 cells. This provides the first evidence that synthetic C-DIMs originating from cruciferous vegetables induce apoptosis in human oral cancer cells through the endoplasmic reticulum stress pathway.

  6. A gene expression signature that can predict green tea exposure and chemopreventive efficacy of lung cancer in mice.

    Science.gov (United States)

    Lu, Yan; Yao, Ruisheng; Yan, Ying; Wang, Yian; Hara, Yukihiko; Lubet, Ronald A; You, Ming

    2006-02-15

    Green tea has been shown to be a potent chemopreventive agent against lung tumorigenesis in animal models. Previously, we found that treatment of A/J mice with either green tea (0.6% in water) or a defined green tea catechin extract (polyphenon E; 2.0 g/kg in diet) inhibited lung tumor tumorigenesis. Here, we described expression profiling of lung tissues derived from these studies to determine the gene expression signature that can predict the exposure and efficacy of green tea in mice. We first profiled global gene expressions in normal lungs versus lung tumors to determine genes which might be associated with the tumorigenic process (TUM genes). Gene expression in control tumors and green tea-treated tumors (either green tea or polyphenon E) were compared to determine those TUM genes whose expression levels in green tea-treated tumors returned to levels seen in normal lungs. We established a 17-gene expression profile specific for exposure to effective doses of either green tea or polyphenon E. This gene expression signature was altered both in normal lungs and lung adenomas when mice were exposed to green tea or polyphenon E. These experiments identified patterns of gene expressions that both offer clues for green tea's potential mechanisms of action and provide a molecular signature specific for green tea exposure.

  7. On using Mobile IP Protocols

    Directory of Open Access Journals (Sweden)

    Fayza A. Nada

    2006-01-01

    Full Text Available The recent advances in wireless communication technology and the unprecedented growth of the Internet have paved the way for wireless networking and IP mobility. Mobile Internet protocol has been designed within the IETF to support the mobility of users who wish to connect to the Internet and maintain communications as they move from place to place. This study describes and summarizes the current Internet draft for mobile IP (MIPv4 with its major components: agent discovery, registration and tunneling. In addition, we outline the available encapsulation techniques and route optimization procedure. In the end, we describe the design of the new protocol for transparent routing of IPv6 packets to mobile IPv6 nodes operating in the Internet.

  8. Heuristic Methods for Security Protocols

    Directory of Open Access Journals (Sweden)

    Qurat ul Ain Nizamani

    2009-10-01

    Full Text Available Model checking is an automatic verification technique to verify hardware and software systems. However it suffers from state-space explosion problem. In this paper we address this problem in the context of cryptographic protocols by proposing a security property-dependent heuristic. The heuristic weights the state space by exploiting the security formulae; the weights may then be used to explore the state space when searching for attacks.

  9. Building America House Simulation Protocols

    Energy Technology Data Exchange (ETDEWEB)

    Hendron, Robert [National Renewable Energy Lab. (NREL), Golden, CO (United States); Engebrecht, Cheryn [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2010-09-01

    The House Simulation Protocol document was developed to track and manage progress toward Building America's multi-year, average whole-building energy reduction research goals for new construction and existing homes, using a consistent analytical reference point. This report summarizes the guidelines for developing and reporting these analytical results in a consistent and meaningful manner for all home energy uses using standard operating conditions.

  10. Heuristic Methods for Security Protocols

    OpenAIRE

    Qurat ul Ain Nizamani; Emilio Tuosto

    2009-01-01

    Model checking is an automatic verification technique to verify hardware and software systems. However it suffers from state-space explosion problem. In this paper we address this problem in the context of cryptographic protocols by proposing a security property-dependent heuristic. The heuristic weights the state space by exploiting the security formulae; the weights may then be used to explore the state space when searching for attacks.

  11. New Models for Protocol Security

    Science.gov (United States)

    2015-06-18

    protocols and primitives (e.g., Schnorrs identification scheme, commitment schemes secure against selective openings, Chaum Blind Signatures , etc...Theory 156: 246-268 (2015) 5 3. Samantha Leung, Edward Lui, Rafael Pass: Voting with Coarse Beliefs. ITCS 2015: 61 4. Jing Chen, Silvio Micali, Rafael...Schneider: Multi-Verifier Signatures . J. Cryptology 25(2): 310-348 (2012) 7 37. Rafael Pass, Muthuramakrishnan Venkitasubramaniam: A Parallel Repetition

  12. National protocol framework for the inventory and monitoring of bees

    Science.gov (United States)

    Droege, Sam; Engler, Joseph D.; Sellers, Elizabeth A.; Lee O'Brien,

    2016-01-01

    This national protocol framework is a standardized tool for the inventory and monitoring of the approximately 4,200 species of native and non-native bee species that may be found within the National Wildlife Refuge System (NWRS) administered by the U.S. Fish and Wildlife Service (USFWS). However, this protocol framework may also be used by other organizations and individuals to monitor bees in any given habitat or location. Our goal is to provide USFWS stations within the NWRS (NWRS stations are land units managed by the USFWS such as national wildlife refuges, national fish hatcheries, wetland management districts, conservation areas, leased lands, etc.) with techniques for developing an initial baseline inventory of what bee species are present on their lands and to provide an inexpensive, simple technique for monitoring bees continuously and for monitoring and evaluating long-term population trends and management impacts. The latter long-term monitoring technique requires a minimal time burden for the individual station, yet can provide a good statistical sample of changing populations that can be investigated at the station, regional, and national levels within the USFWS’ jurisdiction, and compared to other sites within the United States and Canada. This protocol framework was developed in cooperation with the United States Geological Survey (USGS), the USFWS, and a worldwide network of bee researchers who have investigated the techniques and methods for capturing bees and tracking population changes. The protocol framework evolved from field and lab-based investigations at the USGS Bee Inventory and Monitoring Laboratory at the Patuxent Wildlife Research Center in Beltsville, Maryland starting in 2002 and was refined by a large number of USFWS, academic, and state groups. It includes a Protocol Introduction and a set of 8 Standard Operating Procedures or SOPs and adheres to national standards of protocol content and organization. The Protocol Narrative

  13. Automatic analysis of distance bounding protocols

    CERN Document Server

    Malladi, Sreekanth; Kothapalli, Kishore

    2010-01-01

    Distance bounding protocols are used by nodes in wireless networks to calculate upper bounds on their distances to other nodes. However, dishonest nodes in the network can turn the calculations both illegitimate and inaccurate when they participate in protocol executions. It is important to analyze protocols for the possibility of such violations. Past efforts to analyze distance bounding protocols have only been manual. However, automated approaches are important since they are quite likely to find flaws that manual approaches cannot, as witnessed in literature for analysis pertaining to key establishment protocols. In this paper, we use the constraint solver tool to automatically analyze distance bounding protocols. We first formulate a new trace property called Secure Distance Bounding (SDB) that protocol executions must satisfy. We then classify the scenarios in which these protocols can operate considering the (dis)honesty of nodes and location of the attacker in the network. Finally, we extend the const...

  14. DSTC Layering Protocols in Wireless Cooperative Networks

    CERN Document Server

    Elamvazhuthi, P S; Dey, B K

    2008-01-01

    In adhoc wireless relay networks, layers of relays are used to communicate from a source to a destination to achieve better reliability. In this paper, we consider five protocols derived from an earlier proposed protocol, where the relays do a simple processing before transmitting and as a result achieve distributed space-time code. Four of the protocols discussed utilize more complicated relaying schemes than simple layered protocols proposed in earlier literature. We have analyzed the effectiveness of these protocols in various power loss configurations among the paths. Optimum power allocation of the total power among various transmissions have been found by reasonable fine search for all the protocols. Bit error rate plots are compared under optimum power allocation for these protocols. From the simulation results, we draw some guidelines as to which protocol is good for what kind of environment.

  15. Language, Semantics, and Methods for Security Protocols

    DEFF Research Database (Denmark)

    Crazzolara, Federico

    used to give a formal semantics to security protocols which supports proofs of their correctness. More precisely, we give a compositional event-based semantics to an economical, but expressive, language for describing security protocols (SPL); so the events and dependency of a wide range of protocols......Security protocols help in establishing secure channels between communicating systems. Great care needs therefore to be taken in developing and implementing robust protocols. The complexity of security-protocol interactions can hide, however, security weaknesses that only a formal analysis can...... reveal. The last few years have seen the emergence of successful intensional, event-based, formal approaches to reasoning about security protocols. The methods are concerned with reasoning about the events that a security protocol can perform, and make use of a causal dependency that exists between...

  16. The reliable multicast protocol application programming interface

    Science.gov (United States)

    Montgomery , Todd; Whetten, Brian

    1995-01-01

    The Application Programming Interface for the Berkeley/WVU implementation of the Reliable Multicast Protocol is described. This transport layer protocol is implemented as a user library that applications and software buses link against.

  17. Automatic Generation of Network Protocol Gateways

    DEFF Research Database (Denmark)

    Bromberg, Yérom-David; Réveillère, Laurent; Lawall, Julia

    2009-01-01

    for describing protocol behaviors, message structures, and the gateway logic.  Z2z includes a compiler that checks essential correctness properties and produces efficient code. We have used z2z to develop a number of gateways, including SIP to RTSP, SLP to UPnP, and SMTP to SMTP via HTTP, involving a range......The emergence of networked devices in the home has made it possible to develop applications that control a variety of household functions. However, current devices communicate via a multitude of incompatible protocols, and thus gateways are needed to translate between them.  Gateway construction......, however, requires an intimate knowledge of the relevant protocols and a substantial understanding of low-level network programming, which can be a challenge for many application programmers. This paper presents a generative approach to gateway construction, z2z, based on a domain-specific language...

  18. MAXIMUM PRODUCTION OF TRANSMISSION MESSAGES RATE FOR SERVICE DISCOVERY PROTOCOLS

    Directory of Open Access Journals (Sweden)

    Intisar Al-Mejibli

    2011-12-01

    Full Text Available Minimizing the number of dropped User Datagram Protocol (UDP messages in a network is regarded asa challenge by researchers. This issue represents serious problems for many protocols particularly thosethat depend on sending messages as part of their strategy, such us service discovery protocols.This paper proposes and evaluates an algorithm to predict the minimum period of time required betweentwo or more consecutive messages and suggests the minimum queue sizes for the routers, to manage thetraffic and minimise the number of dropped messages that has been caused by either congestion or queueoverflow or both together. The algorithm has been applied to the Universal Plug and Play (UPnPprotocol using ns2 simulator. It was tested when the routers were connected in two configurations; as acentralized and de centralized. The message length and bandwidth of the links among the routers weretaken in the consideration. The result shows Better improvement in number of dropped messages `amongthe routers.

  19. Novel satellite transport protocol with on-board spoofing proxy

    Institute of Scientific and Technical Information of China (English)

    Liu Jiong; Cao Zhigang; Wang Jinglin

    2006-01-01

    As a result of the exponential growing rate of worldwide Internet usage, satellite systems are required to support broadband Internet applications. The transmission control protocol (TCP) which is widely used in the Internet, performs very well on wired networks. However, in the case of satellite channels, due to the delay and transmission errors, TCP performance degrades significantly and bandwidth of satellite links can not be fully utilized. To improve the TCP performance, a new idea of placing a TCP spoofing proxy in the satellite is considered. A Novel Satellite Transport Protocol (NSTP) which takes advantage of the special properties of the satellite channel is also proposed. By using simulation, as compared with traditional TCPs, the on-board spoofing proxy integrated with the special transport protocol can significantly enhance throughput performance on the high BER satellite link, the time needed to transfer files and the bandwidth used in reverse path are sharply reduced.

  20. An Evaluation of Protocols for UAV Science Applications

    Science.gov (United States)

    Ivancic, William D.; Stewart, David E.; Sullivan, Donald V.; Finch, Patrick E.

    2012-01-01

    This paper identifies data transport needs for current and future science payloads deployed on the NASA Global Hawk Unmanned Aeronautical Vehicle (UAV). The NASA Global Hawk communication system and operational constrains are presented. The Genesis and Rapid Intensification Processes (GRIP) mission is used to provide the baseline communication requirements as a variety of payloads were utilized in this mission. User needs and desires are addressed. Protocols are matched to the payload needs and an evaluation of various techniques and tradeoffs are presented. Such techniques include utilization rate-base selective negative acknowledgement protocols and possible use of protocol enhancing proxies. Tradeoffs of communication architectures that address ease-of-use and security considerations are also presented.

  1. Performance Evaluation of Reactive Protocols for Ad Hoc Wireless Sensor Network

    Directory of Open Access Journals (Sweden)

    Rashmi A Bichkar

    2012-10-01

    Full Text Available The requirement for good Quality of Service in Mobile Ad Hoc Network is that, better protocols should be used. To improve protocol efficiency, the two key issues to be considered are, low control overhead and low energy consumption. For reducing energy consumption and routing overhead, an enhanced routing algorithm, EEDSR (Energy Efficient Dynamic Source Routing with local route enhancement model for DSR (Dynamic Source Routing is implemented. Comparisons based on routing overhead, energy and throughput is done between EEDSR and EEAODV (Energy Efficient Ad Hoc on Demand Distance Vector and AODV (Ad Hoc on Demand Distance Vector protocols. For all protocols, NS-2.34 Simulator is used. This paper presents the simulation results in order to choose the best routing protocol to give highest performance. The simulations have shown that EEDSR protocol performs well as it consumes 12�0less energy than EEAODV and AODV

  2. ACSEPP On-Line Electronic Payment Protocol

    Institute of Scientific and Technical Information of China (English)

    WANG Shao-bin; ZHU Xian; HONG Fan

    2004-01-01

    With analyzing the existing on-line electronic payment protocols, this paper presents a new on-line electronic payment protocol named ACSEPP: Anonymous, Convenient and Secure Electronic Payment Protocol.Its aim is to design a practical electronic payment protocol which is both secure and convenient.Without using PKI_CA frame, it realized the anonymity of consumer and merchant, the convenient of handling, the low cost of maintenance and the security.

  3. Security Verification of Secure MANET Routing Protocols

    Science.gov (United States)

    2012-03-22

    the destination. The route discovery phase is complete upon receipt of the RREP at the requesting node. The DYMO protocol is a simpler version of AODV ...described in this appendix. The protocols are Secure AODV (SAODV), Secure Efficient Distance Vector (SEAD), and Secure Link State Routing Protocol (SLSP...SECURITY VERIFICATION OF SECURE MANET ROUTING PROTOCOLS THESIS Matthew F. Steele, Captain, USAF AFIT/GCS/ENG/12-03 DEPARTMENT OF THE AIR FORCE AIR

  4. A father protocol for quantum broadcast channels

    CERN Document Server

    Dupuis, F; Dupuis, Fr\\'ed\\'eric; Hayden, Patrick

    2006-01-01

    We present a new protocol for quantum broadcast channels based on the fully quantum Slepian-Wolf protocol. The protocol yields an achievable rate region for entanglement-assisted transmission of quantum information through a quantum broadcast channel that can be considered the quantum analogue of Marton's region for classical broadcast channels. The protocol can be adapted to yield achievable rate regions for unassisted quantum communication and for entanglement-assisted classical communication. Regularized versions of all three rate regions are provably optimal.

  5. Model checking the HAVi leader election protocol

    OpenAIRE

    Romijn, J.M.T.

    1999-01-01

    The HAVi specification proposes an architecture for audio/video interoperability in home networks. Part of the HAVi specification is a distributed leader election protocol. We have modelled this leader election protocol in Promela and Lotos and have checked several properties with the tools Spin and Xtl (from the Caesar/Aldebaran package). It turns out that the protocol does not meet some safety properties and that there are situations in which the protocol may never converge to designate a l...

  6. New dimensions in SNMP Protocol in Romania

    Directory of Open Access Journals (Sweden)

    Alice Nastovici

    2009-06-01

    Full Text Available In this year 2009, after e-finance shock made in each banks who worked with Simple NetworkManagement Protocol (SNMP default community string and vulnerability:- If you do not absolutely require SNMP, disable it- If you must use SNMP, use the same policy for community names as used for passwords.Make sure that they are difficult to guess or crack and that they are chanced periodically- Validate and check community names using SNMPwalk. Additional information can be foundat http://www.2nd.com/functionSNMPwalk.php- Filter SNMP (port 161/udp at the border-router or firewall unless it is absolutely necessary topool or manage devices from outside of the local network, where possible read-only

  7. Performance measurements of a data link protocol

    Science.gov (United States)

    Kanakia, Hemant; Tobagi, Fouad

    The end-to-end performance of a program implementing IEEE Std 802.2 logical link control protocol, which provides virtual circuit and datagram service and which constitutes the top sublayer of the data link layer of the reference model for Local Area Networks is studied. The measurements of relative execution times of various functions required in transferring data, over virtual circuits or as datagrams, showed that most of the program execution time is spent in a few relatively low-level functions. One of these functions performs block movement of data in memory, and two other functions provide access to various queues. Based on this result, two alternative versions of the program which move data efficiently were written and measured. In this paper the results of the study are reported and their impact on designing hardware and software systems for a network interface are discussed.

  8. Remote Sensing and the Kyoto Protocol: A Workshop Summary

    Science.gov (United States)

    Rosenqvist, Ake; Imhoff, Marc; Milne, Anthony; Dobson, Craig

    2000-01-01

    The Kyoto Protocol to the United Nations Framework Convention on Climate Change contains quantified, legally binding commitments to limit or reduce greenhouse gas emissions to 1990 levels and allows carbon emissions to be balanced by carbon sinks represented by vegetation. The issue of using vegetation cover as an emission offset raises a debate about the adequacy of current remote sensing systems and data archives to both assess carbon stocks/sinks at 1990 levels, and monitor the current and future global status of those stocks. These concerns and the potential ratification of the Protocol among participating countries is stimulating policy debates and underscoring a need for the exchange of information between the international legal community and the remote sensing community. On October 20-22 1999, two working groups of the International Society for Photogrammetry and Remote Sensing (ISPRS) joined with the University of Michigan (Michigan, USA) to convene discussions on how remote sensing technology could contribute to the information requirements raised by implementation of, and compliance with, the Kyoto Protocol. The meeting originated as a joint effort between the Global Monitoring Working Group and the Radar Applications Working Group in Commission VII of the ISPRS, co-sponsored by the University of Michigan. Tile meeting was attended by representatives from national government agencies and international organizations and academic institutions. Some of the key themes addressed were: (1) legal aspects of transnational remote sensing in the context of the Kyoto Protocol; (2) a review of the current and future and remote sensing technologies that could be applied to the Kyoto Protocol; (3) identification of areas where additional research is needed in order to advance and align remote sensing technology with the requirements and expectations of the Protocol; and 94) the bureaucratic and research management approaches needed to align the remote sensing

  9. Some Attacks On Quantum-based Cryptographic Protocols

    CERN Document Server

    Lo, H K; Lo, Hoi-Kwong; Ko, Tsz-Mei

    2003-01-01

    Quantum-based cryptographic protocols are often said to enjoy security guaranteed by the fundamental laws of physics. However, subtle attacks that are outside the original design of the protocols may allow eavesdroppers to break those protocols. As an example, we will give a peeking attack against a quantum key distribution scheme based on quantum memory. Moreover, if technological assumptions are made in the design of a quantum-based cryptographic protocol, then the actual security of the protocol may fall short of expectations. This is because it is often hard to quantify those technological assumptions in a precise manner. Here, we give an attack against a recently proposed ``secure communication using coherent state scheme''. Our attack requires only beamsplitters and the replacement of a lossy channel by a lossless one. It is successful provided that the original loss in the channel is so big that Eve can obtain 2^k copies of what Bob receives, where k is the length of the seed key pre-shared by Alice an...

  10. A novel protocol for multiparty quantum key management

    Science.gov (United States)

    Xu, Gang; Chen, Xiu-Bo; Dou, Zhao; Yang, Yi-Xian; Li, Zongpeng

    2015-08-01

    Key management plays a fundamental role in the field of cryptography. In this paper, we propose a novel multiparty quantum key management (QKM) protocol. Departing from single-function quantum cryptography protocols, our protocol has a salient feature in that it accomplishes a complete QKM process. In this process, we can simultaneously realize the functions of key generation, key distribution and key backup by executing the protocol once. Meanwhile, for the first time, we propose the idea of multi-function QKM. Firstly, the secret key is randomly generated by managers via the quantum measurements in -level Bell basis. Then, through entanglement swapping, the secret key is successfully distributed to users. Under circumstances of urgent requirement, all managers can cooperate to recover the users' secret key, but neither of them can recover it unilaterally. Furthermore, this protocol is further generalized into the multi-manager and multi-user QKM scenario. It has clear advantages in the burgeoning area of quantum security group communication. In this system, all group members share the same group key, and group key management is the foundation of secure group communication and hence an important subject of study.

  11. 3DMRP: 3-Directional Zone-Disjoint Multipath Routing Protocol

    Science.gov (United States)

    Shin, Dongseung; Kim, Dongkyun

    In static wireless ad hoc networks such as wireless mesh networks and wireless sensor networks, multipath routing techniques are very useful for improving end-to-end delay, throughput, and load balancing, as compared to single-path routing techniques. When determining multiple paths, however, multipath routing protocols should address the well-known route coupling problem that results from a geographic proximity of adjacent routes and that hampers performance gain. Although a lot of multipath routing protocols have been proposed, most of them focused on obtaining node or link-disjoint multipaths. In order to address the route coupling problem, some multipath routing protocols utilizing zone-disjointness property were proposed. However, they suffer from an overhead of control traffic or require additional equipment such as directional antenna. This paper therefore proposes a novel multipath routing protocol, based on geographical information with low overhead, called 3-directional zone-disjoint multipath routing protocol (3DMRP). 3DMRP searches up to three zone-disjoint paths by using two techniques: 1) greedy forwarding, and 2) RREP-overhearing. One primary and two secondary paths are obtained via greedy forwarding in order to reduce control overhead, and these secondary paths are found by avoiding the RREP overhearing zone created during the primary path acquisition. In particular, two versions of 3DMRP are introduced in order to avoid the RREQ-overhearing zone. Through ns-2 simulations, 3DMRP is evaluated to verify that it achieves performance improvements in terms of throughput and control overhead.

  12. A Lock—Based Cache Coherence Protocol for Scope Consistency

    Institute of Scientific and Technical Information of China (English)

    胡伟武; 施巍松; 等

    1998-01-01

    Directory protocols are widely adopted to maintain cache coherence of distributed shared memory multiprocessors.Although scalable to a certain extent,directory protocols are complex enough to prevent it from being used in very large scale multiprocessors with tens of thousands of nodes.his paper proposes a lock-based cache coherence protocol for scope consistency.In does not rely on directory information to maintain cache coherence.Instead,cache coherence is maintained through requiring the releasing processor of a lock to stroe all write-notices generated in the associated critical section to the lock and the acquiring processor invalidates or updates its locally cached data copies according to the write notices of the lock.To evaluate the performance of the lock-based cache coherence protocol,a software SDM system named JIAJIA is built on network of workstations.Besides the lock-based cache coherence protocol,JIAJIA also characterizes itself with its shared memory organization scheme which combines the physical memories of multiple workstations to form a large shared space.Performance measurements with SPLASH2 program suite and NAS benchmarks indicate that,compared to recent SVM systems such as CVM,higher speedup is achieved by JIAJIA.Besides,JIAJIA can solve large scale problems that cannot be solved by other SVM systems due to memory size limitation.

  13. Accessibility in Public Buildings: Efficiency of Checklist Protocols.

    Science.gov (United States)

    Andersson, Jonas E; Skehan, Terry

    2016-01-01

    In Sweden, governmental agencies and bodies are required to implement a higher level of accessibility in their buildings than that stipulated by the National Building and Planning Act (PBL). The Swedish Agency for Participation (MFD, Myndigheten för delaktighet) develops holistic guidelines in order to conceptualize this higher level of accessibility. In conjunction to these guidelines, various checklist protocols have been produced. The present study focuses on the efficiency of such checklist protocols. The study revolved around the use of a checklist protocol in assessments of two buildings in Stockholm: the new head office for the National Authority for Social Insurances (ASI) and the School of Architecture at the Royal Institute of Technology (KTH). The study included three groups: Group 1 and Group 2 consisted of 50 real estate managers employed by the ASI, while Group 3 consisted of three participants in a course at the KTH. The results were similar in all of the groups. The use of the checklist protocol generated queries, which related mainly to two factors: (1) the accompanying factsheet consisted of textual explanations with no drawings, photographs or illustrations and (2) the order of the questions in the checklist protocol was difficult to correlate with the two buildings' spatial logic of accessing, egressing and making use of the built space.

  14. Mean Response Time Approximation for HTTP Transactions over Transport Protocols

    Directory of Open Access Journals (Sweden)

    Y. J. Lee

    2014-12-01

    Full Text Available This paper addresses mean response time that end-users experience when using the Internet. HTTP (Hyper Text Transfer Protocol is a widely used transfer protocol to retrieve web objects in the Internet. Generally, HTTP uses TCP (Transmission Control Protocol in a transport layer. But it is known that HTTP interacts with TCP inefficiently. As an example of such inefficiencies, HTTP does not require TCP to deliver the rigid order, which may cause head-of-line blocking. As another transport layer protocol, SCTP (Stream Control Transmission Protocol has attractive features such as multi-streaming and multi-homing unlike TCP. Within an SCTP association, multi-streaming allows for independent delivery among streams, thus can avoid the head-of-line blocking. In addition, SCTP provides very large number of streams; therefore, it can transfer multiple objects more efficiently than the typical HTTP/1.1 over TCP which limits the number of pipelines. Mean response time is one of the main measures that end users using Internet concern. This paper presents the simple analytical model and algorithm to find the mean response time for HTTP over SCTP including the previous HTTP over TCP. Some computational experiences show that the proposed model and algorithm are well approximated to the real environment. Also, it is shown that mean response time for HTTP over SCTP can be less than that for HTTP over TCP.

  15. Bioinspired Security Analysis of Wireless Protocols

    DEFF Research Database (Denmark)

    Petrocchi, Marinella; Spognardi, Angelo; Santi, Paolo

    2016-01-01

    work, this paper investigates feasibility of adopting fraglets as model for specifying security protocols and analysing their properties. In particular, we give concrete sample analyses over a secure RFID protocol, showing evolution of the protocol run as chemical dynamics and simulating an adversary...

  16. Static Validation of a Voting Protocol

    DEFF Research Database (Denmark)

    Nielsen, Christoffer Rosenkilde; Andersen, Esben Heltoft; Nielson, Hanne Riis

    2005-01-01

    The desired security properties of electronic voting protocols include verifiability, accuracy, democracy and fairness. In this paper we use a static program analysis tool to validate these properties for one of the classical voting protocols under appropriate assumptions. The protocol is formali...

  17. Proposed experiment for the quantum "Guess my number" protocol

    CERN Document Server

    Cabello, A; Cabello, Adan; Lopez-Tarrida, Antonio J.

    2005-01-01

    An experimental realization of the entanglement-assisted "Guess my number" protocol for the reduction of communication complexity, introduced by Steane and van Dam, would require producing and detecting three-qubit GHZ states with an efficiency eta > 0.70, which would require single photon detectors of efficiency sigma > 0.89. We propose a modification of the protocol which can be translated into a real experiment using present-day technology. In the proposed experiment, the quantum reduction of the multi-party communication complexity would require an efficiency eta > 0.05, achievable with detectors of sigma > 0.47, for four parties, and eta > 0.17 (sigma > 0.55) for three parties.

  18. Low-cost, low-input RNA-seq protocols perform nearly as well as high-input protocols

    Directory of Open Access Journals (Sweden)

    Peter A. Combs

    2015-03-01

    Full Text Available Recently, a number of protocols extending RNA-sequencing to the single-cell regime have been published. However, we were concerned that the additional steps to deal with such minute quantities of input sample would introduce serious biases that would make analysis of the data using existing approaches invalid. In this study, we performed a critical evaluation of several of these low-volume RNA-seq protocols, and found that they performed slightly less well in per-gene linearity of response, but with at least two orders of magnitude less sample required. We also explored a simple modification to one of these protocols that, for many samples, reduced the cost of library preparation to approximately $20/sample.

  19. Constructing UC Secure and Constant-Round Group Key Exchange Protocols via Secret Sharing

    Directory of Open Access Journals (Sweden)

    Sangjae Moon

    2008-07-01

    Full Text Available Group key exchange (GKE is one of the basic building blocks in securing group communication. A number of solutions to GKE problem have been proposed, but most of them are not scalable and require a number of rounds linear with the number of group members. We present a method of constructing constant-round and identity-based protocol via secret sharing for GKE within universally composability (UC framework. The resultant protocol focuses on round efficiency and three rounds of communication are required. The protocol allows the batch verification of messages signed by all other group participants. Moreover, compared with other identity-based protocols, the key generation center (KGC in our protocol is not always online.

  20. Constructing UC Secure and Constant-Round Group Key Exchange Protocols via Secret Sharing

    Directory of Open Access Journals (Sweden)

    Moon Sangjae

    2008-01-01

    Full Text Available Abstract Group key exchange (GKE is one of the basic building blocks in securing group communication. A number of solutions to GKE problem have been proposed, but most of them are not scalable and require a number of rounds linear with the number of group members. We present a method of constructing constant-round and identity-based protocol via secret sharing for GKE within universally composability (UC framework. The resultant protocol focuses on round efficiency and three rounds of communication are required. The protocol allows the batch verification of messages signed by all other group participants. Moreover, compared with other identity-based protocols, the key generation center (KGC in our protocol is not always online.

  1. Self-Adaptive and Energy-Efficient MAC Protocol Based on Event-Driven

    Directory of Open Access Journals (Sweden)

    Xin Hou

    2013-01-01

    Full Text Available Combined with WSN MAC layer protocol characteristics and design requirements, according to the characteristic of WSN monitoring application requirements, this paper puts forward a method based on event driven MAC protocol. The agreement algorithm is to solve the problem of network congestion and node energy unnecessary consumption cause by a large number of redundant monitoring data transceiver. It is a kind of adaptive low power consumption of the MAC layer protocol, which is pointed out based on theoretical foundation of S_MAC protocol, made use of the event driven mechanism system theory, combined with event driven mechanism and the characteristics of the WSN. It has the periodic dormancy mechanism of S_MAC protocol, in the premise of the reliability data, to reduce data redundancy and communication delay time, improve the overall network throughput, to ensure the safety and reliability of the network, which can greatly extends  the node of working time.

  2. A climate change plan for the purposes of the Kyoto Protocol Implementation Act

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2008-05-15

    In response to concerns about climate change, the Government of Canada is taking comprehensive actions to reduce Canada's greenhouse gas emissions. This document constituted the climate change plan for 2008 that the Canadian government was required to publish under section 5 of the Kyoto Protocol Implementation Act. The report provided background information on the Kyoto Protocol Implementation Act and outlined Canada's Kyoto Protocol targets and obligations. It also presented Canada's greenhouse gas emissions in 2006 and discussed the economics of the Kyoto Protocol Implementation Act. Actions to address climate change as well as provincial territorial collaboration and action were also outlined. Timelines for achievement of emissions targets were presented. It was concluded that with this document, the Minister of the Environment has responded to the publication requirements of section 5 of the Kyoto Protocol Implementation Act. The action plan was found to be a realistic, balanced and achievable plan. refs., tabs.

  3. Colorectal Chemoprevention with Calcium and Vitamin D | Division of Cancer Prevention

    Science.gov (United States)

    DESCRIPTION: In this application we propose to complete CA098286, a double-blind, randomized, controlled trial of supplementation with vitamin D and/or calcium for the prevention of colorectal adenomas. The study builds on extensive epidemiological and experimental data indicating that both vitamin D and calcium have anti-neoplastic effects in the large bowel and that these agents interact, each requiring the other for full effect. Despite the strong supporting |

  4. Designing an Exploration Atmosphere Prebreathe Protocol

    Science.gov (United States)

    Conkin, Johnny; Feiveson, A. H.; Gernhardt, M. L.; Norcross, J. R.; Wessel, J. H., III

    2015-01-01

    Extravehicular activities (EVAs) at remote locations must maximize limited resources such as oxygen (O2) and also minimize the risk of decompression sickness (DCS). A proposed remote denitrogenation (prebreathe) protocol requires astronauts to live in a mildly hypoxic atmosphere at 8.2 psia while periodically performing EVAs at 4.3 psia. Empirical data are required to confirm that the protocol meets the current accept requirements: less than or equal to 15% incidence of Type I DCS, less than or equal to 20% incidence of Grade IV venous gas emboli (VGE), both at 95% statistical confidence, with no Type II DCS symptom during the validation trial. METHODS: A repeated measures statistical design is proposed in which groups of 6 subjects with physical characteristics similar to active-duty astronauts would first become equilibrated to an 8.2 psia atmosphere in a hypobaric chamber containing 34% O2 and 66% N2, over 48 h, and then perform 4 simulated EVAs at 4.3 psia over the next 9 days. In the equilibration phase, subjects undergo a 3-h 100% O2 mask prebreathe prior to and during a 5-min ascent to 8.2 psia to prevent significant tissue N2 supersaturation on reaching 8.2 psia. Masks would be removed once 34% O2 is established at 8.2 psia, and subjects would then equilibrate to this atmosphere for 48 h. The hypoxia is equivalent to breathing air at 1,220 meters (4,000 ft) altitude, just as was experienced in the shuttle 10.2 psia - 26.5% O2 staged denitrogenation protocol and the current ISS campout denitrogenation protocol. For simulated EVAs, each subject dons a mask and breathes 85% O2 and 15% N2 during a 3-min depressurization to 6.0 psia, holds for 15 min, and then completes a 3-min depressurization to 4.3 psia. The simulated EVA period starts when 6.0 psia is reached and continues for a total of 240 min (222 min at 4.3 psia). During this time, subjects will follow a prescribed repetitive activity against loads in the upper and lower body with mean metabolic rate

  5. Analysing ZigBee Key Establishment Protocols

    CERN Document Server

    Yüksel, Ender

    2012-01-01

    In this report, we present our approach for protocol analysis together with a real example where we find an important flow in a contemporary wireless sensor network security protocol. We start by modelling protocols using a specific process algebraic formalism called LySa process calculus. We then apply an analysis based on a special program analysis technique called control flow analysis. We apply this technique to the ZigBee-2007 End-to-End Application Key Establishment Protocol and with the help of the analysis discover an unknown flaw. Finally we suggest a fix for the protocol, and verify that the fix works by using the same technique.

  6. Control room envelope unfiltered air inleakage test protocols

    Energy Technology Data Exchange (ETDEWEB)

    Lagus, P.L. [Lagus Applied Technology, San Diego, CA (United States); Grot, R.A. [Lagus Applied Technology, Olney, MD (United States)

    1997-08-01

    In 1983, the Advisory Committee on Reactor Safeguards (ACRS) recommended that the US NRC develop a control room HVAC performance testing protocol. To date no such protocol has been forthcoming. Beginning in mid-1994, an effort was funded by NRC under a Small Business Innovation Research (SBIR) grant to develop several simplified test protocols based on the principles of tracer gas testing in order to measure the total unfiltered inleakage entering a CRE during emergency mode operation of the control room ventilation system. These would allow accurate assessment of unfiltered air inleakage as required in SRP 6.4. The continuing lack of a standard protocol is unfortunate since one of the significant parameters required to calculate operator dose is the amount of unfiltered air inleakage into the control room. Often it is assumed that, if the Control Room Envelope (CRE) is maintained at +1/8 in. w.g. differential pressure relative to the surroundings, no significant unfiltered inleakage can occur it is further assumed that inleakage due to door openings is the only source of unfiltered air. 23 refs., 13 figs., 2 tabs.

  7. Simplified 3D protocol capable of generating early cortical neuroepithelium

    Science.gov (United States)

    Holmes, Dwayne B.

    2017-01-01

    ABSTRACT Here, we report a 3D cerebellar differentiation protocol with quick startup method, defined medium and no special materials or handling requirements. Three fibroblast growth factors (FGF2, 4 and 8) were used for cerebellar patterning and smoothened agonist (SAG) for granule cell development. After 35 days, differentiation products exhibited similar structures and neuronal markers reported in prior ‘organoid’ and ‘spheroid’ protocols. This included cells positive for KIRREL2 (a marker of early cerebellar neuroepithelium) and ZIC1 (a marker for granule cells). Follow-up tests indicated that addition of FGFs, if helpful, was not required to generate observed structures and cell types. This suggests that intrinsic production of patterning factors by aggregates themselves may be adequate for region-specific 3D modeling. This protocol may be used as a quick, easy and cost-efficient method for 3D culture, whether to research development of the early cerebellar neuroepithelium, a base to generate mature cortical structures, or to optimize minimal-factor protocols for other brain regions. PMID:28167491

  8. Effective Protocols for Mobile Communications and Networking

    Energy Technology Data Exchange (ETDEWEB)

    Espinoza, J.; Sholander, P.; Van Leeuwen, B,

    1998-12-01

    This report examines methods of mobile communications with an emphasis on mobile computing and wireless communications. Many of the advances in communications involve the use of Internet Protocol (IP), Asynchronous Transfer Mode (ATM), and ad hoc network protocols. However, many of the advances in these protocols have been focused on wired communications. Recently much focus has been directed at advancing communication technology in the area of mobile wireless networks. This report discusses various protocols used in mobile communications and proposes a number of extensions to existing protocols. A detailed discussion is also included on desirable protocol characteristics and evaluation criteria. In addition, the report includes a discussion on several network simulation tools that maybe used to evaluate network protocols.

  9. Authenticating Tripartite Key Agreement Protocol with Pairings

    Institute of Scientific and Technical Information of China (English)

    Sheng-Li Liu; Fang-Guo Zhang; Ke-Fei Chen

    2004-01-01

    In this paper, an authenticated tripartite key agreement protocol is proposed, which is an ID-based one with pairings. This protocol involves only one round. The authenticity of the protocol is assured by a special signature scheme, so that messages carrying the information of two ephemeral keys can be broadcasted authentically by an entity. Consequently, one instance of the protocol results in eight session keys for three entities. In other word, one instance of the protocol generates a session key, which is eight times longer than those obtained from traditional key agreement protocols. Security attributes of the protocol are presented, and the computational overhead and bandwidth of the broadcast messages are analyzed as well.

  10. Tool Supported Analysis of Web Services Protocols

    DEFF Research Database (Denmark)

    Marques, Abinoam P.; Ravn, Anders Peter; Srba, Jiri

    2011-01-01

    e.g. in the design of web services protocols, into an intermediate XML format. We further translate this format into a network of communicating state machines directly suitable for verification in the model checking tool UPPAAL. We introduce two types of communication media abstractions in order......We describe an abstract protocol model suitable for modelling of web services and other protocols communicating via unreliable, asynchronous communication channels. The model is supported by a tool chain where the first step translates tables with state/transition protocol descriptions, often used...... to ensure the finiteness of the protocol state-spaces while still being able to verify interesting protocol properties. The translations for different kinds of communication media have been implemented and successfully tested, among others, on agreement protocols from WS-Business Activity....

  11. Research on Container Behaviors Protocol

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    With the development of middleware technology, there are some new features to be adopted on demand in middleware platform based on container component. Aiming at the adaptation of middleware platform, from the nature of component container, this paper begins with behaviors features of EJB (Enterprise Java Bean) container, extracts general behaviors protocol of container, and defines its formal behaviors specification. In the end, the interactive relationship of components is described by WRIGHT language, and the configuration of whole system is shown. The method proposed in this paper mines the hidden features of framework of component container, and applies to refactor middleware platform in reflection and aspect-oriented programming technology.

  12. New Models for Population Protocols

    CERN Document Server

    Michail, Othon

    2010-01-01

    Wireless sensor networks are about to be part of everyday life. Homes and workplaces capable of self-controlling and adapting air-conditioning for different temperature and humidity levels, sleepless forests ready to detect and react in case of a fire, vehicles able to avoid sudden obstacles or possibly able to self-organize routes to avoid congestion, and so on, will probably be commonplace in the very near future. Mobility plays a central role in such systems and so does passive mobility, that is, mobility of the network stemming from the environment itself. The population protocol model was

  13. Experimental quantum multiparty communication protocols

    Science.gov (United States)

    Smania, Massimiliano; Elhassan, Ashraf M.; Tavakoli, Armin; Bourennane, Mohamed

    2016-06-01

    Quantum information science breaks limitations of conventional information transfer, cryptography and computation by using quantum superpositions or entanglement as resources for information processing. Here we report on the experimental realisation of three-party quantum communication protocols using single three-level quantum system (qutrit) communication: secret-sharing, detectable Byzantine agreement and communication complexity reduction for a three-valued function. We have implemented these three schemes using the same optical fibre interferometric setup. Our realisation is easily scalable without compromising on detection efficiency or generating extremely complex many-particle entangled states.

  14. A structured data transfer protocol

    Science.gov (United States)

    Barrett, P.; Rots, A.

    1992-01-01

    The transfer of data between different computers and programs can be a major obstacle during data analysis. We present a new data transfer protocol which is based on a simple structure containing a value, an error, and a unit. Each of these members can be arrays or another structure. The ability to nest structures allows for the concept of objects. When using an object-oriented language such as C++, reference can be made to the object name instead of each element explicitly. Prototype code has been written which implements the basic design with enhancements planned for the future.

  15. Chemopreventive effects of Cuminum cyminum in chemically induced forestomach and uterine cervix tumors in murine model systems.

    Science.gov (United States)

    Gagandeep; Dhanalakshmi, Sivanandhan; Méndiz, Ester; Rao, Agra Ramesha; Kale, Raosaheb Kathalupant

    2003-01-01

    Lately, a strong correlation has been established between diet and cancer. For ages, cumin has been a part of the diet. It is a popular spice regularly used as a flavoring agent in a number of ethnic cousins. In the present study, cancer chemopreventive potentials of different doses of a cumin seed-mixed diet were evaluated against benzo(a)pyrene [B(a)P]-induced forestomach tumorigenesis and 3-methylcholanthrene (MCA)-induced uterine cervix tumorigenesis. Results showed a significant inhibition of stomach tumor burden (tumors per mouse) by cumin. Tumor burden was 7.33 +/- 2.10 in the B(a)P-treated control group, whereas it reduced to 3.10 +/- 0.57 (P < 0.001) by a 2.5% dose and 3.11 +/- 0.60 (P <0.001) by a 5% dose of cumin seeds. Cervical carcinoma incidence, compared with the MCA-treated control group (66.67%), reduced to 27.27% (P < 0.05) by a diet of 5% cumin seeds and to 12.50% (P < 0.05) by a diet of 7.5% cumin seeds. The effect of 2.5 and 5% cumin seed-mixed diets was also examined on carcinogen/xenobiotic metabolizing phase I and phase II enzymes, antioxidant enzymes, glutathione content, lactate dehydrogenase (LDH), and lipid peroxidation in the liver of Swiss albino mice. Levels of cytochrome P-450 (cyt P-450) and cytochrome b5 (cyt b(5)) were significantly augmented (P < 0.05) by the 2.5% dose of cumin seed diet. The levels of cyt P-450 reductase and cyt b(5) reductase were increased (significance level being from P < 0.05 to P < 0.01) by both doses of cumin. Among the phase II enzymes, glutathione S-transferase specific activity increased (P < 0.005) by the 5% dose, whereas that of DT-diaphorase increased significantly (P < 0.05) by both doses used (2.5 and 5%). In the antioxidant system, significant elevation of the specific activities of superoxide dismutase (P < 0.01) and catalase (P < 0.05) was observed with the 5% dose of cumin. The activities of glutathione peroxidase and glutathione reductase remained unaltered by both doses of cumin. The level

  16. Anti-proliferative and proapoptotic effects of (-)-epigallocatechin-3-gallate on human melanoma: possible implications for the chemoprevention of melanoma.

    Science.gov (United States)

    Nihal, Minakshi; Ahmad, Nihal; Mukhtar, Hasan; Wood, Gary S

    2005-04-20

    Melanoma accounts for only about 4% of all skin cancer cases but most of skin cancer-related deaths. Standard systemic therapies such as interferon (IFN) have not been adequately effective in the management of melanoma. Therefore, novel approaches are needed for prevention and treatment of this disease. Chemoprevention by naturally occurring agents present in food and beverages has shown benefits in certain cancers including nonmelanoma skin cancers. Here, employing 2 human melanoma cell lines (A-375 amelanotic malignant melanoma and Hs-294T metastatic melanoma) and normal human epidermal melanocytes (NHEM), we studied the antiproliferative effects of epigallocatechin-3-gallate (EGCG), the major polyphenolic antioxidant present in green tea. EGCG treatment was found to result in a dose-dependent decrease in the viability and growth of both melanoma cell lines. Interestingly, at similar EGCG concentrations, the normal melanocytes were not affected. EGCG treatment of the melanoma cell lines resulted in decreased cell proliferation (as assessed by Ki-67 and PCNA protein levels) and induction of apoptosis (as assessed cleavage of PARP, TUNEL assay and JC-1 assay). EGCG also significantly inhibited the colony formation ability of the melanoma cells studied. EGCG treatment of melanoma cells resulted in a downmodulation of anti-apoptotic protein Bcl2, upregulation of proapoptotic Bax and activation of caspases -3, -7 and -9. Furthermore, our data demonstrated that EGCG treatment resulted in a significant, dose-dependent decrease in cyclin D1 and cdk2 protein levels and induction of cyclin kinase inhibitors (ckis) p16INK4a, p21WAF1/CIP1 and p27KIP1. Our data suggest that EGCG causes significant induction of cell cycle arrest and apoptosis of melanoma cells that is mediated via modulations in the cki-cyclin-cdk network and Bcl2 family proteins. Thus, EGCG, alone or in conjunction with current therapies, could be useful for the management of melanoma.

  17. The chemopreventive potential of Curcuma purpurascens rhizome in reducing azoxymethane-induced aberrant crypt foci in rats.

    Science.gov (United States)

    Rouhollahi, Elham; Moghadamtousi, Soheil Zorofchian; Al-Henhena, Nawal; Kunasegaran, Thubasni; Hasanpourghadi, Mohadeseh; Looi, Chung Yeng; Abd Malek, Sri Nurestri; Awang, Khalijah; Abdulla, Mahmood Ameen; Mohamed, Zahurin

    2015-01-01

    Curcuma purpurascens BI. rhizome, a member of the Zingiberaceae family, is a popular spice in Indonesia that is traditionally used in assorted remedies. Dichloromethane extract of C. purpurascens BI. rhizome (DECPR) has previously been shown to have an apoptosis-inducing effect on colon cancer cells. In the present study, we examined the potential of DECPR to prevent colon cancer development in rats treated with azoxymethane (AOM) (15 mg/kg) by determining the percentage inhibition in incidence of aberrant crypt foci (ACF). Starting from the day immediately after AOM treatment, three groups of rats were orally administered once a day for 2 months either 10% Tween 20 (5 mL/kg, cancer control), DECPR (250 mg/kg, low dose), or DECPR (500 mg/kg, high dose). Meanwhile, the control group was intraperitoneally injected with 5-fluorouracil (35 mg/kg) for 5 consecutive days. After euthanizing the rats, the number of ACF was enumerated in colon tissues. Bax, Bcl-2, and proliferating cell nuclear antigen (PCNA) protein expressions were examined using immunohistochemical and Western blot analyses. Antioxidant enzymatic activity was measured in colon tissue homogenates and associated with malondialdehyde level. The percentage inhibition of ACF was 56.04% and 68.68% in the low- and high-dose DECPR-treated groups, respectively. The ACF inhibition in the treatment control group was 74.17%. Results revealed that DECPR exposure at both doses significantly decreased AOM-induced ACF formation, which was accompanied by reduced expression of PCNA. Upregulation of Bax and downregulation of Bcl-2 suggested the involvement of apoptosis in the chemopreventive effect of DECPR. In addition, the oxidative stress resulting from AOM treatment was significantly attenuated after administration of DECPR, which was shown by the elevated antioxidant enzymatic activity and reduced malondialdehyde level. Taken together, the present data clearly indicate that DECPR significantly inhibits ACF formation

  18. 植物多酚对胃癌的化学预防%Chemoprevention of plant polyphenols in gastric cancer

    Institute of Scientific and Technical Information of China (English)

    刘入铭; 姜晶; 马麟; 曹雪源

    2012-01-01

    胃癌的发病是多因素相互作用的过程,与宿主因素、幽门螺杆菌(Hp)感染、饮食等因素相关.植物多酚是广泛存在于植物中的一大类多酚化合物的总称,具有较强的抗氧化性,许多动物实验和临床研究表明,多酚类物质能够通过抑制Hp感染、抑制核转录因子-κB(NF-κB)表达、促进肿瘤细胞凋亡等多种途径实现对胃癌的抑制.植物多酚的应用拓宽了胃癌化学预防的途径.%Gastric cancer carcinogenesis is a multifactorial process which is related to an interaction of host factors,Helieobacter pylori (Hp) infection,dietary factors and so on.The plant polyphenols which are widely present in many plants are the general term for a large group polyphenolic compounds.They have strong antioxidant activity.Furthermore,many animal experiments and clinical studies have proved that the polyphenols could inhibit gastric cancer via inhibiting Hp infection,suppressing the expression of nuclear factor-κB (NF-κB),promoting apoptosis in cancer cells and so on.The application of plant polyphenols could broaden the approaches for chemoprevention of gastric cancer.

  19. Chemopreventive effect of Korean Angelica root extract on TRAMP carcinogenesis and integrative "omic" profiling of affected neuroendocrine carcinomas.

    Science.gov (United States)

    Zhang, Jinhui; Wang, Lei; Zhang, Yong; Li, Li; Tang, Suni; Xing, Chengguo; Kim, Sung-Hoon; Jiang, Cheng; Lü, Junxuan

    2015-12-01

    Angelica gigas Nakai (AGN) root ethanol extract exerts anti-cancer activity in several allograft and xenograft models. Here we examined its chemopreventive efficacy through gavage administration against primary carcinogenesis in the transgenic adenocarcinoma of mouse prostate (TRAMP) model. Male C57BL/6 TRAMP mice and wild type littermates were given a daily gavage (5 mg/mouse, Monday-Friday) of AGN or vehicle, beginning at 8 wk of age (WOA). All mice were terminated at 24 WOA, unless earlier euthanasia was necessitated by large tumors. Whereas AGN-treated TRAMP mice decreased dorsolateral prostate lesion growth by 30% (P = 0.009), they developed fewer and smaller neuroendocrine-carcinomas (NE-Ca) (0.12 g/mouse) than vehicle-treated counterparts (0.81 g/mouse, P = 0.037). We analyzed the proteome and transcriptome of banked NE-Ca to gain molecular insights. Angiogenesis-antibody array detected a substantial reduction in AGN-treated NE-Ca of basic fibroblast growth factor (FGF2), an angiogenesis stimulator. iTRAQ proteomics plus data mining suggested changes of genes upstream and downstream of FGF2 functionally consistent with AGN inhibiting FGF2/FGFR1 signaling at different levels of the transduction cascade. Moreover, AGN upregulated mRNA of genes related to immune responses, restored expression of many tumor suppressor genes, and prostate function and muscle differentiation genes. On the other hand, AGN down-regulated mRNA of genes related to neuron signaling, oncofetal antigens, inflammation, and mast cells, Wnt signaling, embryonic morphogenesis, biosynthesis, cell adhesion, motility, invasion, and angiogenesis. These changes suggest not only multiple cancer cell targeting actions of AGN but also impact on the tumor microenvironments such as angiogenesis, inflammation, and immune surveillance.

  20. Disruption of androgen and estrogen receptor activity in prostate cancer by a novel dietary diterpene carnosol: implications for chemoprevention

    Science.gov (United States)

    Johnson, Jeremy J.; Syed, Deeba N.; Suh, Yewseok; Heren, Chenelle R.; Saleem, Mohammad; Siddiqui, Imtiaz A.; Mukhtar, Hasan

    2010-01-01

    Emerging data is suggesting that estrogens, in addition to androgens, may also be contributing to the development of prostate cancer (PCa). In view of this notion agents that target estrogens, in addition to androgens, may be a novel approach for PCa chemoprevention and treatment. Thus, the identification and development of non-toxic dietary agents capable of disrupting androgen receptor (AR) in addition to estrogen receptor (ER) could be extremely useful in the management of PCa. Through molecular modeling we found carnosol, a dietary diterpene fits within the ligand binding domain of both AR and ER-α. Using a TR-FRET assay we found that carnosol interacts with both AR and ER-α and additional experiments confirmed that it functions as a receptor antagonist with no agonist effects. LNCaP, 22Rv1, and MCF7 cells treated with carnosol (20–40 µM) showed decreased protein expression of AR and ER-α. Oral administration of carnosol at 30 mg/kg five days weekly for 28 days to 22Rv1 PCa xenografted mice suppressed tumor growth by 36% (p = 0.028) and was associated with a decrease in serum PSA by 26% (p=0.0042). These properties make carnosol unique to any known anti-androgen or anti-estrogen investigated so far for the simultaneous disruption of AR and ER-α. We suggest that carnosol may be developed or chemically modified through more rigorous structure activity relationship studies for a new class of investigational agents - a dual AR/ER modulator. PMID:20736335