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Sample records for chemosensitizing agent ctbt

  1. The chemosensitizing agent lubeluzole binds calmodulin and inhibits Ca(2+)/calmodulin-dependent kinase II.

    Science.gov (United States)

    Bruno, Claudio; Cavalluzzi, Maria Maddalena; Rusciano, Maria Rosaria; Lovece, Angelo; Carrieri, Antonio; Pracella, Riccardo; Giannuzzi, Giulia; Polimeno, Lorenzo; Viale, Maurizio; Illario, Maddalena; Franchini, Carlo; Lentini, Giovanni

    2016-06-30

    An affinity capillary electrophoresis (ACE) method to estimate apparent dissociation constants between bovine brain calmodulin (CaM) and non-peptidic ligands was developed. The method was validated reproducing the dissociation constants of a number of well-known CaM ligands. In particular, the potent antagonist 125-C9 was ad hoc synthesized through an improved synthetic procedure. The ACE method was successfully applied to verify CaM affinity for lubeluzole, a well-known neuroprotective agent recently proved useful to potentiate the activity of anti-cancer drugs. Lubeluzole was slightly less potent than 125-C9 (Kd = 2.9 ± 0.7 and 0.47 ± 0.06 μM, respectively) and displayed Ca(2+)/calmodulin-dependent kinase II (CaMKII) inhibition (IC50 = 40 ± 1 μM). Possible binding modes of lubeluzole to CaM were explored by docking studies based on the X-ray crystal structures of several trifluoperazine-CaM complexes. An estimated dissociation constant in good agreement with the experimental one was found and the main aminoacidic residues and interactions contributing to complex formation were highlighted. The possibility that interference with Ca(2+) pathways may contribute to the previously observed chemosensitizing effects of lubeluzole on human ovarian adenocarcinoma and lung carcinoma cells are discussed. PMID:27043269

  2. CTBT and its implications

    International Nuclear Information System (INIS)

    The Comprehensive Test Ban Treaty (CTBT), whatsoever its shortcomings, is an important step towards nuclear weapons non-proliferation. The question of signing or not signing the Treaty is of vital importance for Pakistan. Pakistan's policy on this question has been India-specific; we have seldom articulated our genuine security concerns and have taken the line that we would sign the Treaty if India did so. Many in Pakistan consider this policy questionable. They are of the view that if India ever decided to sign the CTBT, it would place us in a rather awkward situation. The Pakistan Nuclear Society had organized two one-day seminars in October 1996 on CTBT with a view to creating awareness among the general public of an issue which is of great relevance to Pakistan's security and survival. Although at that time there was no clear intention of publishing these proceedings but in view of the current importance of the subject of CTBT the Pakistan Nuclear Society has decided to publish them. The views expressed here at the learned speakers may have changed their viewpoints in this period cannot bye totally discounted. In spite of certain shortcomings and the difficulties that were encountered in exact transcription, we believe that this small volume would be informative for the general public as an introduction to an issue which is of vital importance not only for the people of Pakistan but for the whole of human race. The nuclear tests conducted by India and Pakistan in May 1998 and the international pressure being exerted on both the countries to sign the CTBT had added to the need for wider dissemination of the Treaty's text and the viewpoints of opinion-makers of the both countries on this subject. For the benefit of readers, the full text of CTBT has been given in the Appendix. (author)

  3. CTBT technical issues handbook

    Energy Technology Data Exchange (ETDEWEB)

    Zucca, J.J. [ed.

    1994-05-01

    The purpose of this handbook is to give the nonspecialist in nuclear explosion physics and nuclear test monitoring an introduction to the topic as it pertains to a Comprehensive Test Ban Treaty (CTBT). The authors have tried to make the handbook visually oriented, with figures paired to short discussions. As such, the handbook may be read straight through or in sections. The handbook covers four main areas and ends with a glossary, which includes both scientific terms and acronyms likely to be encountered during CTBT negotiations. The following topics are covered: (1) Physics of nuclear explosion experiments. This is a description of basic nuclear physics and elementary nuclear weapon design. Also discussed are testing practices. (2) Other nuclear experiments. This section discusses experiments that produce small amounts of nuclear energy but differ from explosion experiments discussed in the first chapter. This includes the type of activities, such as laser fusion, that would continue after a CTBT is in force. (3) Monitoring tests in various environments. This section describes the different physical environments in which a test could be conducted (underground, in the atmosphere, in space, underwater, and in the laboratory); the sources of non-nuclear events (such as earthquakes and mining operations); and the opportunities for evasion. (4) On-site inspections. A CTBT is likely to include these inspections as an element of the verification provisions, in order to resolve the nature of ambiguous events. This chapter describes some technical considerations and technologies that are likely to be useful. (5) Selecting verification measures. This chapter discusses the uncertain nature of the evidence from monitoring systems and how compliance judgments could be made, taking the uncertainties into account. It also discusses how to allocate monitoring resources, given the likelihood of testing by various countries in various environments.

  4. CTBT technical issues handbook

    International Nuclear Information System (INIS)

    The purpose of this handbook is to give the nonspecialist in nuclear explosion physics and nuclear test monitoring an introduction to the topic as it pertains to a Comprehensive Test Ban Treaty (CTBT). The authors have tried to make the handbook visually oriented, with figures paired to short discussions. As such, the handbook may be read straight through or in sections. The handbook covers four main areas and ends with a glossary, which includes both scientific terms and acronyms likely to be encountered during CTBT negotiations. The following topics are covered: (1) Physics of nuclear explosion experiments. This is a description of basic nuclear physics and elementary nuclear weapon design. Also discussed are testing practices. (2) Other nuclear experiments. This section discusses experiments that produce small amounts of nuclear energy but differ from explosion experiments discussed in the first chapter. This includes the type of activities, such as laser fusion, that would continue after a CTBT is in force. (3) Monitoring tests in various environments. This section describes the different physical environments in which a test could be conducted (underground, in the atmosphere, in space, underwater, and in the laboratory); the sources of non-nuclear events (such as earthquakes and mining operations); and the opportunities for evasion. (4) On-site inspections. A CTBT is likely to include these inspections as an element of the verification provisions, in order to resolve the nature of ambiguous events. This chapter describes some technical considerations and technologies that are likely to be useful. (5) Selecting verification measures. This chapter discusses the uncertain nature of the evidence from monitoring systems and how compliance judgments could be made, taking the uncertainties into account. It also discusses how to allocate monitoring resources, given the likelihood of testing by various countries in various environments

  5. Mexico and the CTBT

    International Nuclear Information System (INIS)

    The Comprehensive Nuclear Test-Ban-Treaty (CTBT) is a treaty that prohibits all the nuclear explosions by anybody and in any place, either on the terrestrial surface, in the atmosphere, under the sea or underground. From the adoption of this Treaty by the United Nations, Mexico has had interest for its entrance in vigor, as integral part to assure the international peace. For this reason, our country signed the Treaty since it was open in September 24, 1996 and three years later ratified it, due to Mexico is part of the group of necessary countries for their entrance in vigor. During 13 years, the country has been committed and helped to the installation of monitoring stations, actions that allow the strengthening of the International System of Surveillance. The purpose of this work is to divulge the Treaty,its technologies and benefits; and also to diffuse the works realized by Mexico regarding the radionuclides monitoring station and noble gases both certified ones for the CTBT. Besides the radionuclides technology, Mexico has taken charge of the installation and operation of the seismic stations and hydro-acoustics that have been certified too. The radionuclides station Rn-44 located in Guerrero Negro, BCS has two technologies, an automated sampler of suspended particles in air brand Cinderella/ARAME and a noble gases system Sauna used for the particles detection of radioactive material gamma emitting and Xenon radioisotopes product of nuclear assays. Both technologies are transmitting data in real time to the International Center of Data. These technologies are shown in this work. (Author)

  6. Prenylated Chalcone 2 Acts as an Antimitotic Agent and Enhances the Chemosensitivity of Tumor Cells to Paclitaxel

    Directory of Open Access Journals (Sweden)

    Joana Fonseca

    2016-07-01

    Full Text Available We previously reported that prenylated chalcone 2 (PC2, the O-prenyl derivative (2 of 2′-hydroxy-3,4,4′,5,6′-pentamethoxychalcone (1, induced cytotoxicity of tumor cells via disruption of p53-MDM2 interaction. However, the cellular changes through which PC2 exerts its cytotoxic activity and its antitumor potential, remain to be addressed. In the present work, we aimed to (i characterize the effect of PC2 on mitotic progression and the underlying mechanism; and to (ii explore this information to evaluate its ability to sensitize tumor cells to paclitaxel in a combination regimen. PC2 was able to arrest breast adenocarcinoma MCF-7 and non-small cell lung cancer NCI-H460 cells in mitosis. All mitosis-arrested cells showed collapsed mitotic spindles with randomly distributed chromosomes, and activated spindle assembly checkpoint. Live-cell imaging revealed that the compound induced a prolonged delay (up to 14 h in mitosis, culminating in massive cell death by blebbing. Importantly, PC2 in combination with paclitaxel enhanced the effect on cell growth inhibition as determined by cell viability and proliferation assays. Our findings demonstrate that the cytotoxicity induced by PC2 is mediated through antimitotic activity as a result of mitotic spindle damage. The enhancement effects of PC2 on chemosensitivity of cancer cells to paclitaxel encourage further validation of the clinical potential of this combination.

  7. Prenylated Chalcone 2 Acts as an Antimitotic Agent and Enhances the Chemosensitivity of Tumor Cells to Paclitaxel.

    Science.gov (United States)

    Fonseca, Joana; Marques, Sandra; Silva, Patrícia M A; Brandão, Pedro; Cidade, Honorina; Pinto, Madalena M; Bousbaa, Hassan

    2016-01-01

    We previously reported that prenylated chalcone 2 (PC2), the O-prenyl derivative (2) of 2'-hydroxy-3,4,4',5,6'-pentamethoxychalcone (1), induced cytotoxicity of tumor cells via disruption of p53-MDM2 interaction. However, the cellular changes through which PC2 exerts its cytotoxic activity and its antitumor potential, remain to be addressed. In the present work, we aimed to (i) characterize the effect of PC2 on mitotic progression and the underlying mechanism; and to (ii) explore this information to evaluate its ability to sensitize tumor cells to paclitaxel in a combination regimen. PC2 was able to arrest breast adenocarcinoma MCF-7 and non-small cell lung cancer NCI-H460 cells in mitosis. All mitosis-arrested cells showed collapsed mitotic spindles with randomly distributed chromosomes, and activated spindle assembly checkpoint. Live-cell imaging revealed that the compound induced a prolonged delay (up to 14 h) in mitosis, culminating in massive cell death by blebbing. Importantly, PC2 in combination with paclitaxel enhanced the effect on cell growth inhibition as determined by cell viability and proliferation assays. Our findings demonstrate that the cytotoxicity induced by PC2 is mediated through antimitotic activity as a result of mitotic spindle damage. The enhancement effects of PC2 on chemosensitivity of cancer cells to paclitaxel encourage further validation of the clinical potential of this combination. PMID:27483224

  8. Biostimulative effects of Nd:YAG Q-switch dye on normal human fibroblast cultures: study of a new chemosensitizing agent for the Nd:YAG laser

    Energy Technology Data Exchange (ETDEWEB)

    Castro, D.J.; Saxton, R.E.; Fetterman, H.R.; Castro, D.J.; Ward, P.H.

    1987-12-01

    Kodak Q-switch II is a new chemical with an absorption maxima at 1051 nm, designed to be used as an Nd:YAG dye laser. The potential for this dye as a new chemosensitizing agent in the treatment of connective tissue diseases and wound healing with low energy Nd:YAG laser was examined. Two normal fibroblast cell lines were tested for sensitivity to various levels of this dye in vitro. These cells were exposed to Q-switch II dye at concentrations of 0.01, 0.1, 1, 10, 50, and 100 micrograms/ml for 1 and 24 hours. Cell viability was assessed by the trypan blue exclusion test. Cell duplication and DNA synthesis were measured by the incorporation of (/sup 3/H)-thymidine at 6 and 24 hours postexposure to Q-switch II dye. At concentrations up to 10 micrograms/ml, both cell lines tested showed no changes in cell viability. However, at concentrations equal or higher than 50 micrograms/ml, more than 40% of the fibroblasts incorporated trypan blue after 24 hours of exposure to this dye, indicating significant cell destruction. The results indicate that Q-switch II dye is nontoxic to normal human fibroblast cultures and showed significant biostimulative effects on cell duplication at concentrations equal to or lower than 10 micrograms/ml. Further studies will be required to determine the usefulness of Q-switch II dye as a new photochemosensitizing agent for potential biostimulation of wound healing and/or treatment of connective tissue diseases with the Nd:YAG laser (near infrared, 1060 nm) at nonthermal levels of energies.

  9. Biostimulative effects of Nd:YAG Q-switch dye on normal human fibroblast cultures: study of a new chemosensitizing agent for the Nd:YAG laser

    International Nuclear Information System (INIS)

    Kodak Q-switch II is a new chemical with an absorption maxima at 1051 nm, designed to be used as an Nd:YAG dye laser. The potential for this dye as a new chemosensitizing agent in the treatment of connective tissue diseases and wound healing with low energy Nd:YAG laser was examined. Two normal fibroblast cell lines were tested for sensitivity to various levels of this dye in vitro. These cells were exposed to Q-switch II dye at concentrations of 0.01, 0.1, 1, 10, 50, and 100 micrograms/ml for 1 and 24 hours. Cell viability was assessed by the trypan blue exclusion test. Cell duplication and DNA synthesis were measured by the incorporation of [3H]-thymidine at 6 and 24 hours postexposure to Q-switch II dye. At concentrations up to 10 micrograms/ml, both cell lines tested showed no changes in cell viability. However, at concentrations equal or higher than 50 micrograms/ml, more than 40% of the fibroblasts incorporated trypan blue after 24 hours of exposure to this dye, indicating significant cell destruction. The results indicate that Q-switch II dye is nontoxic to normal human fibroblast cultures and showed significant biostimulative effects on cell duplication at concentrations equal to or lower than 10 micrograms/ml. Further studies will be required to determine the usefulness of Q-switch II dye as a new photochemosensitizing agent for potential biostimulation of wound healing and/or treatment of connective tissue diseases with the Nd:YAG laser (near infrared, 1060 nm) at nonthermal levels of energies

  10. Heterogeneity of chemosensitivity in esophagealcancer using ATP-tumor chemosensitivity assay

    Institute of Scientific and Technical Information of China (English)

    Zhi-qiang LING; Zhi-xing YANG; Jian YIN; Wei-min MAO; Chun-jian QI; Xiao-xiao LU; Li-juan QIAN; Lin-hui GU; Zhi-guo ZHENG; Qiang ZHAO; Shi WANG; Xian-hua FANG

    2012-01-01

    Current chemotherapy for esophageal cancer is conducted on the basis of empirical information from clinical trials,which fails to take into account the known heterogeneity of chemosensitivity between patients.This study was aimed to demonstrate the degree of heterogeneity of chemosensitivity in esophageal cancers.Methods:A total of 42 esophageal cancer specimens were collected.The heterogeneity of chemosensitivity in esophageal cancer specimens was examined using an ex vivo ATP-tumor chemosensitivity assay (ATP-TCA).Results:Thirty eight specimens produced evaluable results (90.5%).The most active single agent tested was nedaplatin,to which 28.9% of samples were sensitive.Combinations of chemotherapy agents exhibited much higher sensitivity:cisplatin+paclitaxel was sensitive in 16 of 38 (42.1%) of samples,while nedaplatin+paclitaxel was more effective,which was sensitive in 20 of 38 cases (52.6%).Conclusion:There was a marked heterogeneity of chemosensitivity in esophageal cancer.Chemosensitivity testing may provide apractical method for testing new regimens before clinical trials in esophageal cancer patients.

  11. CTBT on-site inspections

    Energy Technology Data Exchange (ETDEWEB)

    Zucca, J. J. [Principal Deputy, Global Security Directorate, Lawrence Livermore National Laboratory, Livermore, California (United States)

    2014-05-09

    On-site inspection (OSI) is a critical part of the verification regime for the Comprehensive Nuclear-Test-Ban Treaty (CTBT). The OSI verification regime provides for international inspectors to make a suite of measurements and observations on site at the location of an event of interest. The other critical component of the verification regime is the International Monitoring System (IMS), which is a globally distributed network of monitoring stations. The IMS along with technical monitoring data from CTBT member countries, as appropriate, will be used to trigger an OSI. After the decision is made to carry out an OSI, it is important for the inspectors to deploy to the field site rapidly to be able to detect short-lived phenomena such as the aftershocks that may be observable after an underground nuclear explosion. The inspectors will be on site from weeks to months and will be working with many tens of tons of equipment. Parts of the OSI regime will be tested in a field exercise in the country of Jordan late in 2014. The build-up of the OSI regime has been proceeding steadily since the CTBT was signed in 1996 and is on track to becoming a deterrent to someone considering conducting a nuclear explosion in violation of the Treaty.

  12. Visual inspection for CTBT verification

    Energy Technology Data Exchange (ETDEWEB)

    Hawkins, W.; Wohletz, K.

    1997-03-01

    On-site visual inspection will play an essential role in future Comprehensive Test Ban Treaty (CTBT) verification. Although seismic and remote sensing techniques are the best understood and most developed methods for detection of evasive testing of nuclear weapons, visual inspection can greatly augment the certainty and detail of understanding provided by these more traditional methods. Not only can visual inspection offer ``ground truth`` in cases of suspected nuclear testing, but it also can provide accurate source location and testing media properties necessary for detailed analysis of seismic records. For testing in violation of the CTBT, an offending party may attempt to conceal the test, which most likely will be achieved by underground burial. While such concealment may not prevent seismic detection, evidence of test deployment, location, and yield can be disguised. In this light, if a suspicious event is detected by seismic or other remote methods, visual inspection of the event area is necessary to document any evidence that might support a claim of nuclear testing and provide data needed to further interpret seismic records and guide further investigations. However, the methods for visual inspection are not widely known nor appreciated, and experience is presently limited. Visual inspection can be achieved by simple, non-intrusive means, primarily geological in nature, and it is the purpose of this report to describe the considerations, procedures, and equipment required to field such an inspection.

  13. Mexico and the CTBT; Mexico y el CTBT

    Energy Technology Data Exchange (ETDEWEB)

    Aguirre G, J.; Martinez L, J.; Ruiz E, L. J.; Aragon M, I. B., E-mail: jaguirre@cnsns.gob.mx [Comision Nacional de Seguridad Nuclear y Salvaguardias, Dr. Barragan 779, Col. Narvarte, 03020 Mexico D. F. (Mexico)

    2013-10-15

    The Comprehensive Nuclear Test-Ban-Treaty (CTBT) is a treaty that prohibits all the nuclear explosions by anybody and in any place, either on the terrestrial surface, in the atmosphere, under the sea or underground. From the adoption of this Treaty by the United Nations, Mexico has had interest for its entrance in vigor, as integral part to assure the international peace. For this reason, our country signed the Treaty since it was open in September 24, 1996 and three years later ratified it, due to Mexico is part of the group of necessary countries for their entrance in vigor. During 13 years, the country has been committed and helped to the installation of monitoring stations, actions that allow the strengthening of the International System of Surveillance. The purpose of this work is to divulge the Treaty,its technologies and benefits; and also to diffuse the works realized by Mexico regarding the radionuclides monitoring station and noble gases both certified ones for the CTBT. Besides the radionuclides technology, Mexico has taken charge of the installation and operation of the seismic stations and hydro-acoustics that have been certified too. The radionuclides station Rn-44 located in Guerrero Negro, BCS has two technologies, an automated sampler of suspended particles in air brand Cinderella/ARAME and a noble gases system Sauna used for the particles detection of radioactive material gamma emitting and Xenon radioisotopes product of nuclear assays. Both technologies are transmitting data in real time to the International Center of Data. These technologies are shown in this work. (Author)

  14. CTBT integrated verification system evaluation model supplement

    Energy Technology Data Exchange (ETDEWEB)

    EDENBURN,MICHAEL W.; BUNTING,MARCUS; PAYNE JR.,ARTHUR C.; TROST,LAWRENCE C.

    2000-03-02

    Sandia National Laboratories has developed a computer based model called IVSEM (Integrated Verification System Evaluation Model) to estimate the performance of a nuclear detonation monitoring system. The IVSEM project was initiated in June 1994, by Sandia's Monitoring Systems and Technology Center and has been funded by the U.S. Department of Energy's Office of Nonproliferation and National Security (DOE/NN). IVSEM is a simple, ''top-level,'' modeling tool which estimates the performance of a Comprehensive Nuclear Test Ban Treaty (CTBT) monitoring system and can help explore the impact of various sensor system concepts and technology advancements on CTBT monitoring. One of IVSEM's unique features is that it integrates results from the various CTBT sensor technologies (seismic, in sound, radionuclide, and hydroacoustic) and allows the user to investigate synergy among the technologies. Specifically, IVSEM estimates the detection effectiveness (probability of detection), location accuracy, and identification capability of the integrated system and of each technology subsystem individually. The model attempts to accurately estimate the monitoring system's performance at medium interfaces (air-land, air-water) and for some evasive testing methods such as seismic decoupling. The original IVSEM report, CTBT Integrated Verification System Evaluation Model, SAND97-25 18, described version 1.2 of IVSEM. This report describes the changes made to IVSEM version 1.2 and the addition of identification capability estimates that have been incorporated into IVSEM version 2.0.

  15. CTBT integrated verification system evaluation model supplement

    International Nuclear Information System (INIS)

    Sandia National Laboratories has developed a computer based model called IVSEM (Integrated Verification System Evaluation Model) to estimate the performance of a nuclear detonation monitoring system. The IVSEM project was initiated in June 1994, by Sandia's Monitoring Systems and Technology Center and has been funded by the U.S. Department of Energy's Office of Nonproliferation and National Security (DOE/NN). IVSEM is a simple, ''top-level,'' modeling tool which estimates the performance of a Comprehensive Nuclear Test Ban Treaty (CTBT) monitoring system and can help explore the impact of various sensor system concepts and technology advancements on CTBT monitoring. One of IVSEM's unique features is that it integrates results from the various CTBT sensor technologies (seismic, in sound, radionuclide, and hydroacoustic) and allows the user to investigate synergy among the technologies. Specifically, IVSEM estimates the detection effectiveness (probability of detection), location accuracy, and identification capability of the integrated system and of each technology subsystem individually. The model attempts to accurately estimate the monitoring system's performance at medium interfaces (air-land, air-water) and for some evasive testing methods such as seismic decoupling. The original IVSEM report, CTBT Integrated Verification System Evaluation Model, SAND97-25 18, described version 1.2 of IVSEM. This report describes the changes made to IVSEM version 1.2 and the addition of identification capability estimates that have been incorporated into IVSEM version 2.0

  16. The CTBT National Data Centre: Roles And Functions

    International Nuclear Information System (INIS)

    Following the signature of the Comprehensive Nuclear-Test-Ban Treaty (CTBT) on 23 July 1998, Malaysian Nuclear Agency (Nuclear Malaysia) was designated as the CTBT National Authority in Malaysia. Subsequently, Malaysia ratified the treaty on 17 January 2008. Following the ratification, a CTBT National Data Centre (CTBT-NDC) was established at Nuclear Malaysia. The objective of this paper is to elaborate the unique roles and functions of CTBT-NDC which provide technical support to the CTBT National Authority in carrying out its roles under CTBT as well as promoting the uses of International Monitoring System (IMS) data and International Data Centre (IDC) products for civil and scientific applications. With regards to the verification of events suspected to be a nuclear weapon test, CTBT-NDC performs waveform data analysis using IMS data and IDC products produced by IDC in order to verify the nature of such event. The waveform data analysis could include seismic, hydro acoustic and infra sound data. In addition, an atmospheric transport modeling on possible release of radionuclide particles originated from the nuclear weapon test location is also performed to forecast the global dispersion of radionuclide smoke. The findings from these analyses will be used as technical advice to the CTBT National Authority. Apart from verification purposes, CTBT-NDC also promotes the benefits of IMS data and IDC products for civil and scientific applications such as earth studies, improvement of disaster management and etc. In summary, CTBT NDC plays a unique role in supporting CTBT National Authority to carried out its functions under CTBT as well as promote the full use of IMS data and IDC products for civil and scientific applications. (author)

  17. Environmental radiation measurement in CTBT verification system

    International Nuclear Information System (INIS)

    This paper introduces the technical requirements of the Comprehensive Nuclear-Test-Ban Treaty (CTBT) Radionuclide Stations, the CTBT-related activities carried out by the Japan Atomic Energy Research Institute (JAERI), and the ripple effects of such acquired radionuclide data on general researches. The International Monitoring System (IMS), which is one of the CTBT verification regime. Consists of 80 radionuclide air monitoring stations (of those, 40 stations monitor noble gas as well) and 16 certified laboratories that support these stations throughout the world. For radionuclide air monitoring under the CTBT, the stations collect particulates in the atmosphere on a filter and determine by gamma-ray spectrometry the presence or absence of any radionuclides (e.g. 140Ba, 131I, 99Mo, 132Te, 103Ru, 141Ce, 147Nd, 95Zr, etc.) that offer clear evidence of possible nuclear explosion. Minimum technical requirements are stringently set for the radionuclide air monitoring stations: 500 m3/h air flow rate, 24-hour acquisition time, 10 to 30 Bq/m3 of detection sensitivity for 140Ba, and less than 7 consecutive days, or total of 15 days, a year of shutdown at the stations. For noble gas monitoring, on the other hand, the stations separate Xe from gas elements in the atmosphere and, after purifying and concentrating it, measure 4 nuclides, 131mXe, 133Xe, 133mXe, and 135Xe, by gamma-ray spectrometry or beta-gamma coincidence method. Minimum technical requirements are also set for the noble gas measurement: 0.4 m3/h air flow rate, a full capacity of 10 m3, and 1 Bq/m3 of detection sensitivity for 133Xe, etc. On the request of the Ministry of Education, Culture, Sports and Technology, the JAERI is currently undertaking the establishment of the CTBT radionuclide monitoring stations at both Takasaki (both particle and noble gas) and Okinawa (particle), the certified laboratory at JAERI Tokai, and the National Data Center (NDC 2) at JAERI Tokai, which handles radionuclide data, as

  18. The CTBT verification system. Entering rough waters?

    International Nuclear Information System (INIS)

    Five years after the Comprehensive Nuclear Test Ban Treaty (CTBT) was opened for signature, progress towards entry into force has been slowing. - Political uncertainty about the timing of entry into force is complicating the work of the CTBT Organization's Preparatory Commission (PrepCom). - The US decision, announced on 21 August 2001, not to pay its full share of financial contributions to the PrepCom and withdraw from activities not related to the International Monitoring System (IMS) may put it in non-compliance as a signatory to the treaty. - States need to continue to support the work of the PrepCom by providing it with the necessary financial and technical means. Gaps left by the US decision need to be filled by other states. - Completing the IMS remains a priority task which will need patience and support from all member states of the PrepCom. - Establishing an effective regime for on-site inspections is greatly complicated by the new US policy. Those states in favour of a flexible regime need to redouble their efforts, including increased input into the development of an Operational Manual. - States need to overcome undue concerns about confidentiality and create an open verification regime that makes its data available to scientific and humanitarian relief organisations. - Taken together, these efforts will enable the PrepCom to complete its task of setting up the CTBT's verification system in the foreseeable future. - Washington should live up to its commitment as a signatory to the CTBT and support the whole range of PrepCom activities. - The Article XIV conference should urge the US to reconsider its new policy of reducing support to the PrepCom

  19. CTBT Integrated Verification System Evaluation Model

    Energy Technology Data Exchange (ETDEWEB)

    Edenburn, M.W.; Bunting, M.L.; Payne, A.C. Jr.

    1997-10-01

    Sandia National Laboratories has developed a computer based model called IVSEM (Integrated Verification System Evaluation Model) to estimate the performance of a nuclear detonation monitoring system. The IVSEM project was initiated in June 1994, by Sandia`s Monitoring Systems and Technology Center and has been funded by the US Department of Energy`s Office of Nonproliferation and National Security (DOE/NN). IVSEM is a simple, top-level, modeling tool which estimates the performance of a Comprehensive Nuclear Test Ban Treaty (CTBT) monitoring system and can help explore the impact of various sensor system concepts and technology advancements on CTBT monitoring. One of IVSEM`s unique features is that it integrates results from the various CTBT sensor technologies (seismic, infrasound, radionuclide, and hydroacoustic) and allows the user to investigate synergy among the technologies. Specifically, IVSEM estimates the detection effectiveness (probability of detection) and location accuracy of the integrated system and of each technology subsystem individually. The model attempts to accurately estimate the monitoring system`s performance at medium interfaces (air-land, air-water) and for some evasive testing methods such as seismic decoupling. This report describes version 1.2 of IVSEM.

  20. Political significance of the CTBT (History, status, relationship with the Pelindaba Treaty, etc.)

    International Nuclear Information System (INIS)

    This presentation deals with historical overview, negotiations on CTBT and its adoption, status and verification system of the Treaty, political significance of CTBT and its significance for States signatories in Africa. Separate chapters are devoted to the African region, CTBT Pelindaba Treaty and cooperative prospects and relevance of the CTBT for Africa

  1. CTBT verification-related technologies for peaceful purposes: Implementation of CTBT in Iran

    International Nuclear Information System (INIS)

    Based on its strong policy on disarmament and non proliferation, Islamic Republic of Iran considers CTBT as one of the measures towards the safe world and free from nuclear weapons. It is believed that full implementation of this treaty increases international security as well as national security of every state signatory. It is also considered that it has many scientific and technological benefits for sustainable development of the countries. This paper deals with international monitoring system in Iran, including primary and auxiliary seismic stations, infrasound and radionuclides monitoring systems

  2. Rapid in vitro chemosensitivity analysis of human colon tumor cell lines

    International Nuclear Information System (INIS)

    In oncology, diagnostic assays have the potential to individualize treatment. Due to a large number of chemotherapeutic agents available, a chemosensitivity assay would be of great value for patients receiving chemotherapy. However, no broadly accepted test exists to date. Our work aims at establishing a chemosensitivity test using a microphysiometer, a device that measures the extracellular acidification rate of cells. The test assesses chemosensitivity by comparing the acidification rate of cells treated with cytostatic agents with that of nontreated cells. We performed experiments with two human colon tumor cell lines, HCT 116 and SW620, and cytostatic agents commonly used in therapy of colon carcinoma. We showed that a chemosensitivity test can be reproducibly performed using a microphysiometer. Suitable media and conditions for the assay were found. Test results were further correlated with the crystal violet assay and a tetrazolium salt assay. In comparison, cytostatic effects were rapidly and most clearly displayed with the microphysiometer. Our results suggest that microphysiometry is a promising platform for chemosensitivity testing

  3. JAERI-Tokai radionuclide laboratory in CTBT verification regime

    International Nuclear Information System (INIS)

    In the Comprehensive Nuclear-Test-Ban Treaty (CTBT), the International Monitoring System (IMS) network of radionuclide monitoring stations is to be supported by the radionuclide laboratories (RL), in order to maintain the station performances and verify the presence of fission products originated by nuclear explosion. The RL's have to be certified by the CTBT organization for performance of their systems. The JAERI-Tokai laboratory, which is stated in the treaty as one of the sixteen RL's in the world, is currently engaged in the development of a laboratory needed for certification and has participated in the intercomparison test organized by the CTBT organization as a part of the certification system. In this paper, roles of the RL's and status of the JAERI-Tokai RL are reported together with the results of the international intercomparison test. (author)

  4. Dual-use benefits of the CTBT verification system

    International Nuclear Information System (INIS)

    Since it has been completed in September 1996, the CTBT has been signed by 151 countries. Awaiting the 44 ratifications and entry into force, all of the nuclear powers have imposed unilateral moratoriums on nuclear test explosions. The end of these weapons development activities is often cited as the principal benefit of the CTBT. As the world begins to implement the Treaty, it has become clear that the development and operation of the CTBT verification system will provide a wide range of additional benefits if the data analysis products are available for dual-purpose applications. As this paper describes these could have economic and social implications, especially for countries with limited technical infrastructures. These involve, seismic monitoring, mineral exploration, scientific and technical training

  5. IDEF method for designing seismic information system in CTBT verification

    International Nuclear Information System (INIS)

    Seismic information system is of great importance for improving the capability of CTBT verification. A large amount of money has been appropriated for the research in this field in the U.S. and some other countries in recent years. However, designing and developing a seismic information system involves various technologies about complex system design. This paper discusses the IDEF0 method to construct function models and the IDEF1x method to make information models systemically, as well as how they are used in designing seismic information system in CTBT verification. (authors)

  6. N-methylformamide: cytotoxic, radiosensitizer, or chemosensitizer

    International Nuclear Information System (INIS)

    N-methylformamide (NMF), a polar solvent, is currently being evaluated by the National Cancer Institute (NCI) as an antineoplastic agent because of its activity against colon, mammary, and lung tumor xenografts. Results from preclinical studies suggest that it has radiosensitizing, chemosensitizing, and differentiating activity. Its mechanism of action remains unknown, but may involve cellular depletion of glutathione, cell membrane changes, or modulation of proto-oncogene expression. Preclinical toxicology studies conducted in mice, rats, and beagle dogs showed reversible hepatotoxicity to be dose-limiting. Clinically, NMF is administered both orally and by intravenous (IV) injection. The bioavailability with oral administration is 90% to 95%. The highest reported plasma concentration of NMF is approximately 4 mmol/L in a patient who received a dose of 2,000 mg/m2 of IV NMF. Biphasic elimination with IV NMF is seen on both the daily for five days and weekly for 3 weeks schedule. Approximately 5% to 7% of the total administered IV dose is excreted in the urine. In phase I studies, dose-limiting toxicities included reversible hepatotoxicity, a generalized malaise syndrome, and nausea and vomiting. One partial response has been reported in the 111 patients treated on phase II trials in colorectal, head and neck, and renal carcinomas. Suggestions for the future development of this drug are presented. 82 references

  7. Verification lessons learned and CTBT's contribution to disarmament and nonproliferation

    International Nuclear Information System (INIS)

    The Comprehensive Nuclear-Test-Ban Treaty (CTBT) prohibits all nuclear tests for any purposes. The CTBT is essential for peace and security; it is a core element of the nonproliferation regime. It limits the ability of countries to develop advanced nuclear weapons technology. It is enforced through the extensive International Monitoring System designed to detect and deter nuclear explosions in atmosphere, underwater and underground. In the process of monitoring and detecting a potential nuclear test - the system registers over 30,000 events a year - the vast majority of them are earthquakes. The civil and scientific applications of the CTBT data can be used to gain better understanding of the earth, of climate change, of volcanic ash clouds, of the tsunamis, of the movements of whales and much more. The CTBT sets a new legal and verification standard for nuclear weapons. It is a non-discriminatory Treaty with the same rights and obligations for all Member States. Its verification regime is equally nondiscriminatory and provides equal access for all Member States to CTBTO data. We are driving to achieve 160 ratifications by the end of the year, and this will provide additional momentum towards entry into force (EIF) and universality. (A.C.)

  8. Resistance gene expression determines the in vitro chemosensitivity of non-small cell lung cancer (NSCLC

    Directory of Open Access Journals (Sweden)

    Amer Khalid

    2009-08-01

    Full Text Available Abstract Background NSCLC exhibits considerable heterogeneity in its sensitivity to chemotherapy and similar heterogeneity is noted in vitro in a variety of model systems. This study has tested the hypothesis that the molecular basis of the observed in vitro chemosensitivity of NSCLC lies within the known resistance mechanisms inherent to these patients' tumors. Methods The chemosensitivity of a series of 49 NSCLC tumors was assessed using the ATP-based tumor chemosensitivity assay (ATP-TCA and compared with quantitative expression of resistance genes measured by RT-PCR in a Taqman Array™ following extraction of RNA from formalin-fixed paraffin-embedded (FFPE tissue. Results There was considerable heterogeneity between tumors within the ATP-TCA, and while this showed no direct correlation with individual gene expression, there was strong correlation of multi-gene signatures for many of the single agents and combinations tested. For instance, docetaxel activity showed some dependence on the expression of drug pumps, while cisplatin activity showed some dependence on DNA repair enzyme expression. Activity of both drugs was influenced more strongly still by the expression of anti- and pro-apoptotic genes by the tumor for both docetaxel and cisplatin. The doublet combinations of cisplatin with gemcitabine and cisplatin with docetaxel showed gene expression signatures incorporating resistance mechanisms for both agents. Conclusion Genes predicted to be involved in known mechanisms drug sensitivity and resistance correlate well with in vitro chemosensitivity and may allow the definition of predictive signatures to guide individualized chemotherapy in lung cancer.

  9. The participation of Argentina in the CTBT verification regime

    International Nuclear Information System (INIS)

    Argentina is among the countries involved in the CTBT with seismic, radionuclide and infra sound stations. In May 1998, a Provisional Agreement was signed between the Argentine Ministry of Foreign Affairs and the Executive Secretary of the Provisional technical Secretariat to allow technicians and equipment of the CTBTO to start the harmonization and upgrade of the monitoring stations located in Argentina. It started, through Instituto de Prevencion Sismica (INPRES), participating with the group of Scientific experts at the Conference of Disarmament. Concerning radionuclide monitoring and infra sound technologies Argentina participates with its stations managed by the Nuclear Regulatory Authority. Participation of Argentina in the CTBT is considered as an excellent opportunity for interchanging information and experiences among Argentine experts and experts from other countries

  10. Measurement of 7Be in CTBT radionuclide stations verification samples

    International Nuclear Information System (INIS)

    The Comprehensive Nuclear-Test-Ban Treaty (CTBT) International Monitoring System (IMS) radionuclide network, including 80 stations, was designed to monitor nuclear test all over the word. The stations should be certified by CTBT to comply with the technical requirements. Among the certification tests carried out at each station, parallel sampling with portable particle sampler is performed. The verification samples from the portable air sampler will be analyzed at radionuclide laboratories to calibrate the equipment of stations. According to technical requirement of radionuclide station certification, this article deduced the formula of 7Be radioactivity concentration. The preparation and analysis procedure of verification samples were established. As part of certification of radionuclide stations RN42 and RN56, the verification samples from these two stations were measured by HPGe γ spectrometer in Beijing Radionuclide Laboratory. (authors)

  11. The present status of the CTBT verification regime

    International Nuclear Information System (INIS)

    The Comprehensive nuclear-Test-Ban Treaty (CTBT) was opened for signature on September 24, 1996. As of November 17, 2006 the numbers of Signatories and Ratifications are 177 and 137 respectively. The Preparatory Commission for the CTBT Organization, which consists of Signatures, has been preparing for the verification regime in order to monitor compliance with the Treaty. With 10 years passage the International Monitoring System is switching from establishing to operating phase and has functioned effectively to detect nuclear explosions. On the other hand many issues has arisen in long pending of not entering into force, which was not supposed in early time; for example restructuring of the organization for conforming operational body and its nature and status and technology refreshment. Also data globally acquired are being used for civil and scientific applications and attempts are made with increasing interaction between the Organization, Signatories and scientific community. This paper presents an overview of status of the verification regime, discuss future course and issues, and also expresses JAEA's programme related to the CTBT. (author)

  12. In vitro chemosensitivity of head and neck cancer cell lines

    Directory of Open Access Journals (Sweden)

    Schuler PJ

    2010-08-01

    Full Text Available Abstract Background Systemic treatment of head and neck squamous cell carcinoma (HNSCC includes a variety of antineoplastic drugs. However, drug-resistance interferes with the effectiveness of chemotherapy. Preclinical testing models are needed in order to develop approaches to overcome chemoresistance. Methods Ten human cell lines were obtained from HNSCC, including one with experimentally-induced cisplatin resistance. Inhibition of cell growth by seven chemotherapeutic agents (cisplatin, carboplatin, 5- fluorouracil, methotrexate, bleomycin, vincristin, and paclitaxel was measured using metabolic MTT-uptake assay and correlated to clinically-achievable plasma concentrations. Results All drugs inhibited cell growth in a concentration-dependent manner with an IC50 comparable to that achievable in vivo. However, response curves for methotrexate were unsatisfactory and for paclitaxel, the solubilizer cremophor EL was toxic. Cross-resistance was observed between cisplatin and carboplatin. Conclusion Chemosensitivity of HNSCC cell lines can be determined using the MTT-uptake assay. For DNA-interfering cytostatics and vinca alkaloids this is a simple and reproducible procedure. Determined in vitro chemosensitivity serves as a baseline for further experimental approaches aiming to modulate chemoresistance in HNSCC with potential clinical significance.

  13. The CTBT Verification Regime: Monitoring the Earth for nuclear explosions

    International Nuclear Information System (INIS)

    The Comprehensive nuclear-Test-Ban Treaty (CTBT) bans all nuclear weapon tests. Its unique verification regime is designed to detect nuclear explosions anywhere on the planet - in the oceans, underground and in the atmosphere. once complete, the international Monitoring system (iMs) will consist of 337 facilities located in 89 countries around the globe. The iMs is currently operating in test mode so that data are already transmitted for analysis from monitoring facilities to the international Data Centre (iDC) at the headquarters of the preparatory Commission for the Comprehensive nuclear-Test-Ban Treaty Organization (CTBTO) in Vienna. Data and analysis results are shared with Member states.

  14. Accessing chemosensitivity and ventilatory stability from transient stimuli.

    Science.gov (United States)

    Bruce, E N

    1996-12-01

    The degree of ventilatory stability of human subjects is inferred from the presence or absence of oscillations in ventilation in response to a brief CO2 disturbance using the method of pseudorandom stimulation. Simultaneously, chemosensitivity is measured. Stability and chemosensitivity are compared in hyperoxia between wakefulness and stage 2 non-rapid eye movement (NREM) sleep and between normoxia and hyperoxia awake. Stability is unchanged between wakefulness and sleep but chemosensitivity decreases in sleep. In contrast, stability is reduced in normoxia whereas chemosensitivity is larger than in hyperoxia. It is concluded that chemosensitivity and ventilatory stability may change independently, implying that chemosensitivity alone is not an adequate indicator of the likelihood of a subject to exhibit periodic breathing. PMID:9085498

  15. Radio-xenon monitoring technology for CTBT verification

    International Nuclear Information System (INIS)

    To help ensure compliance with a comprehensive nuclear test ban treaty (CTBT), it is important that monitoring technologies for detecting covert nuclear testing be available. Monitoring methods are included seismic, hydroacoustic, infra-sound, and radionuclide technologies. Conducting a test underground, underwater, under such condition, gaseous radionuclides detection would be useful method for detecting of nuclear detonation. This report described on as to performance of detecting equipment and detecting principle of radioactive described on as to performance of detecting equipment and detecting principle of radioactive noble gas detection for CTBT. Although the quantity of xenon radionuclides entering the atmosphere from a nuclear detonation may be very large, the combination of dilution in the atmosphere plus radioactive decay requires very sensitive measurements to detect these radionuclides. Furthermore, xenon radionuclides can be enter the atmosphere from sources other than nuclear detonation, including operating nuclear reactors, producing and using medical isotopes and nuclear fuel reprocessing. Since measurement of the activity ratios of xenon radionuclides is important for determine of their origin. (author). 19 refs., 13 tabs., 18 figs

  16. Recent status of research activities for development of CTBT-related technologies in JAERI

    International Nuclear Information System (INIS)

    This report describes research activities of the R and D Group for Non-Proliferation Technology related to the Comprehensive Nuclear-Test-Ban Treaty (CTBT) verification regime. The main subjects of this report are (1) an overview of the CTBT verification regime, (2) preparation of the National Data Center for radionuclide data, (3) construction and operation of the radionuclide monitoring stations at Takasaki and Okinawa and the certified radionuclide laboratory at Tokai in Japan. We have participated in an intercomparison test internationally organized for the certified laboratories and the test results are given here. Scientific application of the CTBT-related technologies to environmental researches is also depicted. (author)

  17. The National Radiation Protection Authority and its regulatory programme. Potential benefits of the CTBT and thoughts on cooperation

    International Nuclear Information System (INIS)

    In the past years Ethiopia became an active participant in the scientific and political development as well as supporter of the CTBT. This paper describes the designated institution for the CTBT implementation in the area of Radionuclides in Ethiopia and its scientific and regulatory program as well as main activities concerning application techniques. The second part of the paper accounts for the links between the objectives of the national institute with the CTBT. It draws substantive details about benefits that could arise from participating in CTBT implementation and summarizes the discussion by suggesting modalities for building partnership and cooperation

  18. Completing and sustaining IMS network for the CTBT Verification Regime

    Science.gov (United States)

    Meral Ozel, N.

    2015-12-01

    The CTBT International Monitoring System is to be comprised of 337 facilities located all over the world for the purpose of detecting and locating nuclear test explosions. Major challenges remain, namely the completion of the network where most of the remaining stations have either environmental, logistical and/or political issues to surmont (89% of the stations have already been built) and the sustainment of a reliable and state-of the-art network covering 4 technologies - seismic, infrasound , hydroacoustic and radionuclide. To have a credible and trustworthy verification system ready for entry into force of the Treaty, the CTBTO is protecting and enhancing its investment of its global network of stations and is providing effective data to the International Data Centre (IDC) and Member States. Regarding the protection of the CTBTO's investment and enhanced sustainment of IMS station operations, the IMS Division is enhancing the capabilities of the monitoring system by applying advances in instrumentation and introducing new software applications that are fit for purpose. Some examples are the development of noble gas laboratory systems to process and analyse subsoil samples, development of a mobile noble gas system for onsite inspection purposes, optimization of Beta Gamma detectors for Xenon detection, assessing and improving the efficiency of wind noise reduction systems for infrasound stations, development and testing of infrasound stations with a self-calibrating capability, and research into the use of modular designs for the hydroacoustic network.

  19. Evaluation of database technologies for the CTBT Knowledge Base prototype

    Energy Technology Data Exchange (ETDEWEB)

    Keyser, R.; Shepard-Dombroski, E.; Baur, D.; Hipp, J.; Moore, S.; Young, C.; Chael, E.

    1996-11-01

    This document examines a number of different software technologies in the rapidly changing field of database management systems, evaluates these systems in light of the expected needs of the Comprehensive Test Ban Treaty (CTBT) Knowledge Base, and makes some recommendations for the initial prototypes of the Knowledge Base. The Knowledge Base requirements are examined and then used as criteria for evaluation of the database management options. A mock-up of the data expected in the Knowledge Base is used as a basis for examining how four different database technologies deal with the problems of storing and retrieving the data. Based on these requirement and the results of the evaluation, the recommendation is that the Illustra database be considered for the initial prototype of the Knowledge Base. Illustra offers a unique blend of performance, flexibility, and features that will aid in the implementation of the prototype. At the same time, Illustra provides a high level of compatibility with the hardware and software environments present at the US NDC (National Data Center) and the PIDC (Prototype International Data Center).

  20. Action plan for the comprehensive nuclear-test-ban treaty (CTBT) Malaysian National Data Centre

    International Nuclear Information System (INIS)

    The Comprehensive Nuclear-Test-Ban Treaty (CTBT) is a keystone of the international regime on the non-proliferation of nuclear weapons and an essential basis for the pursuit of nuclear disarmament. Its total ban of any nuclear weapon test explosion moreover will restrict the development and qualitative improvement of nuclear weapons and end the development of advanced new types of these weapons. One of the key features of this treaty is the development of an International Monitoring System (IMS) to detect any nuclear weapon test. The IMS comprises a network of 321 monitoring stations and 16 radionuclide laboratories that monitor the Earth for evidence of nuclear explosions. It uses four verification methods, including seismic, hydroacoustic and infrasound, in addition to radionuclide monitoring of the underground, underwater and atmosphere environments, respectively, whereas, radionuclide monitoring can detect radioactive debris vented from atmospheric, underground or underwater nuclear explosions. Malaysia signed the CTBT on 23 July 1998, and is currently in the process of drafting a national CTBT Act to facilitate ratification. As provided for under the Treaty, one of the radionuclide-monitoring stations (Rain) under the IMS will be located in Malaysia. The station is under the responsibility of the Malaysian Nuclear Agency, as the National Authority for the CTBT. The operation of the IMS is supported by an International Data Centre (IDC) CTBT, which is based at the headquarters of the Preparatory Commission for the CTBT Organization (CTBTO) in Vienna. To facilitate the acquisition of data from the IMS for the purposes of verifying compliance with the Treaty in general, and to enable Malaysia to benefit from the scientific applications of the data obtainable from the IDC, a CTBT National Data Centre (NDC) is the process of being established in Malaysia , which is targeted to be fully operational by the third quarter of 2007. (Author)

  1. Aptamer–polymer functionalized silicon nanosubstrates for enhanced recovered circulating tumor cell viability and in vitro chemosensitivity testing

    Science.gov (United States)

    Shen, Qinglin; Peng, Caixia; Zhan, Yan; Fan, Liang; Wang, Mengyi; Zhou, Qing; Liu, Jue; Lv, Xiaojuan; Tang, Qiu; Li, Jun; Huang, Xiaodong; Xia, Jiahong

    2016-01-01

    Selection of the optimal chemotherapy regimen for an individual cancer patient is challenging. The existing chemosensitivity tests are costly, time-consuming, and not amenable to wide utilization within a clinic. This limitation might be addressed by the recently proposed use of circulating tumor cells (CTCs), which provide an opportunity to noninvasively monitor response to therapy. Over the past few decades, various techniques were developed to capture and recover CTCs, but these techniques were often limited by a capture and recovery performance tradeoff between high viability and high efficiency. In this work, we used anti-epithelial cell adhesion molecule coated aptamer–poly (N-isopropylacrylamide) functionalized silicon nanowire substrates to capture and release epithelial cell adhesion molecule-positive CTCs at 32°C and 4°C, respectively. Then, we applied the nuclease to digest the aptamer to release the captured CTCs (near or at the end of the polymer brush), which cannot be released by heating/cooling process. High viability and purity CTCs could be achieved by decreasing the heating/cooling cycles and enzymatic treatment rounds. Furthermore, the time-saving process is helpful to maintain the morphology and enhance vitality of the recovered CTCs and is beneficial to the subsequent cell culture in vitro. We validated the feasibility of chemosensitivity testing based on the recovered HCC827 cells using an adenosine triphosphate–tumor chemosensitivity assay, and the results suggested that our method can determine which agent and what concentration have the best chemosensitivity for the culturing recovered CTCs. So, the novel method capable of a highly effective capture and recovery of high viability CTCs will pave the way for chemosensitivity testing. PMID:27274239

  2. Aptamer-polymer functionalized silicon nanosubstrates for enhanced recovered circulating tumor cell viability and in vitro chemosensitivity testing.

    Science.gov (United States)

    Shen, Qinglin; Peng, Caixia; Zhan, Yan; Fan, Liang; Wang, Mengyi; Zhou, Qing; Liu, Jue; Lv, Xiaojuan; Tang, Qiu; Li, Jun; Huang, Xiaodong; Xia, Jiahong

    2016-01-01

    Selection of the optimal chemotherapy regimen for an individual cancer patient is challenging. The existing chemosensitivity tests are costly, time-consuming, and not amenable to wide utilization within a clinic. This limitation might be addressed by the recently proposed use of circulating tumor cells (CTCs), which provide an opportunity to noninvasively monitor response to therapy. Over the past few decades, various techniques were developed to capture and recover CTCs, but these techniques were often limited by a capture and recovery performance tradeoff between high viability and high efficiency. In this work, we used anti-epithelial cell adhesion molecule coated aptamer-poly (N-isopropylacrylamide) functionalized silicon nanowire substrates to capture and release epithelial cell adhesion molecule-positive CTCs at 32°C and 4°C, respectively. Then, we applied the nuclease to digest the aptamer to release the captured CTCs (near or at the end of the polymer brush), which cannot be released by heating/cooling process. High viability and purity CTCs could be achieved by decreasing the heating/cooling cycles and enzymatic treatment rounds. Furthermore, the time-saving process is helpful to maintain the morphology and enhance vitality of the recovered CTCs and is beneficial to the subsequent cell culture in vitro. We validated the feasibility of chemosensitivity testing based on the recovered HCC827 cells using an adenosine triphosphate-tumor chemosensitivity assay, and the results suggested that our method can determine which agent and what concentration have the best chemosensitivity for the culturing recovered CTCs. So, the novel method capable of a highly effective capture and recovery of high viability CTCs will pave the way for chemosensitivity testing. PMID:27274239

  3. Global Monitoring of the CTBT: Progress, Capabilities and Plans (Invited)

    Science.gov (United States)

    Zerbo, L.

    2013-12-01

    The Preparatory Commission for the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO), established in 1996, is tasked with building up the verification regime of the CTBT. The regime includes a global system for monitoring the earth, the oceans and the atmosphere for nuclear tests, and an on-site inspection (OSI) capability. More than 80% of the 337 facilities of the International Monitoring System (IMS) have been installed and are sending data to the International Data Centre (IDC) in Vienna, Austria for processing. These IMS data along with IDC processed and reviewed products are available to all States that have signed the Treaty. Concurrent with the build-up of the global monitoring networks, near-field geophysical methods are being developed and tested for OSIs. The monitoring system is currently operating in a provisional mode, as the Treaty has not yet entered into force. Progress in installing and operating the IMS and the IDC and in building up an OSI capability will be described. The capabilities of the monitoring networks have progressively improved as stations are added to the IMS and IDC processing techniques refined. Detection thresholds for seismic, hydroacoustic, infrasound and radionuclide events have been measured and in general are equal to or lower than the predictions used during the Treaty negotiations. The measurements have led to improved models and tools that allow more accurate predictions of future capabilities and network performance under any configuration. Unplanned tests of the monitoring network occurred when the DPRK announced nuclear tests in 2006, 2009, and 2013. All three tests were well above the detection threshold and easily detected and located by the seismic monitoring network. In addition, noble gas consistent with the nuclear tests in 2006 and 2013 (according to atmospheric transport models) was detected by stations in the network. On-site inspections of these tests were not conducted as the Treaty has not entered

  4. Research on database realization technology of seismic information system in CTBT verification

    International Nuclear Information System (INIS)

    Developing CTBT verification technology has become the most important method that makes sure CTBT to be fulfilled conscientiously. The seismic analysis based on seismic information system (SIS) is playing an important rule in this field. Based on GIS, the SIS will be very sufficient and powerful in spatial analysis, topologic analysis and visualization. However, the critical issue to implement the whole system function depends on the performance of SIS DB. Based on the ArcSDE Geodatabase data model, not only have the spatial data and attribute data seamless integrated management been realized with RDBMS ORACLE really, but also the most functions of ORACLE have been reserved. (authors)

  5. Prediction of drug efficacy for cancer treatment based on comparative analysis of chemosensitivity and gene expression data

    DEFF Research Database (Denmark)

    Wan, P; Li, Q; Eklund, AC;

    2012-01-01

    The NCI60 database is the largest available collection of compounds with measured anti-cancer activity. The strengths and limitations for using the NCI60 database as a source of new anti-cancer agents are explored and discussed in relation to previous studies. We selected a sub-set of 2333...... compounds with reliable experimental half maximum growth inhibitions (GI(50)) values for 30 cell lines from the NCI60 data set and evaluated their growth inhibitory effect (chemosensitivity) with respect to tissue of origin. This was done by identifying natural clusters in the chemosensitivity data set and...... in a data set of expression profiles of 1901 genes for the corresponding tumor cell lines. Five clusters were identified based on the gene expression data using self-organizing maps (SOM), comprising leukemia, melanoma, ovarian and prostate, basal breast, and luminal breast cancer cells, respectively...

  6. Prediction of drug efficacy for cancer treatment based on comparative analysis of chemosensitivity and gene expression data

    DEFF Research Database (Denmark)

    Wan, Peng; Li, Qiyuan; Larsen, Jens Erik Pontoppidan;

    2012-01-01

    The NCI60 database is the largest available collection of compounds with measured anti-cancer activity. The strengths and limitations for using the NCI60 database as a source of new anti-cancer agents are explored and discussed in relation to previous studies. We selected a sub-set of 2333...... compounds with reliable experimental half maximum growth inhibitions (GI50) values for 30 cell lines from the NCI60 data set and evaluated their growth inhibitory effect (chemosensitivity) with respect to tissue of origin. This was done by identifying natural clusters in the chemosensitivity data set and in...... a data set of expression profiles of 1901 genes for the corresponding tumor cell lines. Five clusters were identified based on the gene expression data using self-organizing maps (SOM), comprising leukemia, melanoma, ovarian and prostate, basal breast, and luminal breast cancer cells, respectively...

  7. CO2 chemosensitivity during immersion in humans.

    Science.gov (United States)

    Chang, L P; Lundgren, C E

    1995-01-01

    Hypercapnic ventilatory response was compared in 9 seated subjects during head-out immersion in 35 degrees C (thermoneutral) water and during non-immersion in 28 degrees C (thermoneutral) room air. Using Read's CO2-rebreathing technique, minute ventilation (VE) and end-tidal (ET) PCO2 were sampled continuously for 4-5 min with a spirometer and a mass spectrometer, while the subject rebreathed a 6 L gas mixture initially containing 7% CO2 and 93% O2 in a bag-in-box system. The slope of the hypercapnic ventilatory response curve, expressed as delta VE/delta PETCO2, ranged from 0.76 to 2.49 L/min/mmHg. Immersion affected neither the slope nor the position of the hypercapnic ventilatory response curve. The rate of rise of PETCO2 during immersed CO2-rebreathing was significantly reduced (4.47 +/- 0.19 [SE] mmHg/min), as compared to the control value (5.67 +/- 0.24). It was concluded that the CO2 chemosensitivity during immersion in humans did not change and that the capacity to store CO2 in tissue might have been increased. PMID:8549236

  8. Noscapine chemosensitization enhances docetaxel anticancer activity and nanocarrier uptake in triple negative breast cancer.

    Science.gov (United States)

    Doddapaneni, Ravi; Patel, Ketan; Chowdhury, Nusrat; Singh, Mandip

    2016-08-01

    Chemosensitization and enhanced delivery to solid tumor are widely explored strategies to augment the anticancer efficacy of existing chemotherapeutics agents. The aim of current research was to investigate the role of low dose Noscapine (Nos) in potentiating docetaxel cytotoxicity and enhancing tumor penetration of nanocarriers. The objectives are; (1) To evaluate the chemo-sensitizing effect of Nos in combination with docetaxel (DTX), and to elucidate the possible mechanism (2) To investigate the effect of low dose Nos on tumor stroma and enhancing nanocarrier uptake in triple negative breast cancer (TNBC) bearing nude mice. Cytotoxicity and flow cytometry analysis of DTX in Nos (4µM) pre-treated MDA-MB-231 cells showed 3.0-fold increase in cell killing and 30% increase in number of late apoptotic cells, respectively. Stress transducer p38 phosphorylation was significantly upregulated with Nos exposure. DTX showed remarkable downregulation in expression of bcl-2, survivin and pAKT in Nos pre-treated MDA-MB-231 cells. Nos pre-sensitization significantly (p<0.02) enhanced the anti-migration effect of DTX. In vivo studies in orthotopic TNBC tumor bearing mice showed marked reduction in tumor collagen-I levels and significantly (p<0.03) higher intra-tumoral uptake of coumarin-6 loaded PEGylated liposomes (7-fold) in Nos treated group. Chemo-sensitization and anti-fibrotic effect of Nos could be a promising approach to increase anticancer efficacy of DTX which can be used for other nanomedicinal products. PMID:27177833

  9. Aptamer-polymer functionalized silicon nanosubstrates for enhanced recovered circulating tumor cell viability and in vitro chemosensitivity testing

    Directory of Open Access Journals (Sweden)

    Shen QL

    2016-05-01

    assay, and the results suggested that our method can determine which agent and what concentration have the best chemosensitivity for the culturing recovered CTCs. So, the novel method capable of a highly effective capture and recovery of high viability CTCs will pave the way for chemosensitivity testing. Keywords: circulating tumor cells, aptamer–PNIPAM coating, capture and recovery, cell culture in vitro, chemosensitivity testing

  10. Salinomycin increases chemosensitivity to the effects of doxorubicin in soft tissue sarcomas

    International Nuclear Information System (INIS)

    Chemotherapy for soft tissue sarcomas remains unsatisfactory due to their low chemosensitivity. Even the first line chemotherapeutic agent doxorubicin only yields a response rate of 18-29%. The antibiotic salinomycin, a potassium ionophore, has recently been shown to be a potent compound to deplete chemoresistant cells like cancer stem like cells (CSC) in adenocarcinomas. Here, we evaluated the effect of salinomycin on sarcoma cell lines, whereby salinomycin mono- and combination treatment with doxorubicin regimens were analyzed. To evaluate the effect of salinomycin on fibrosarcoma, rhabdomyosarcoma and liposarcoma cell lines, cells were drug exposed in single and combined treatments, respectively. The effects of the corresponding treatments were monitored by cell viability assays, cell cycle analysis, caspase 3/7 and 9 activity assays. Further we analyzed NF-κB activity; p53, p21 and PUMA transcription levels, together with p53 expression and serine 15 phosphorylation. The combination of salinomycin with doxorubicin enhanced caspase activation and increased the sub-G1 fraction. The combined treatment yielded higher NF-κB activity, and p53, p21 and PUMA transcription, whereas the salinomycin monotreatment did not cause any significant changes. Salinomycin increases the chemosensitivity of sarcoma cell lines - even at sub-lethal concentrations - to the cytostatic drug doxorubicin. These findings support a strategy to decrease the doxorubicin concentration in combination with salinomycin in order to reduce toxic side effects

  11. Chemosensitization of plant pathogenic fungi to agricultural fungicides

    Science.gov (United States)

    Continual use of fungicides in agriculture often results in development of resistance in pathogens. A new strategy to aid in overcoming or minimizing this problem is enhancement of pathogen sensitivity to fungicides by chemosensitization. This involves combining fungicides with certain non-fungicida...

  12. Analysis of acoustic-seismic coupling behaviour for CTBT on-site inspection performance improvement

    Energy Technology Data Exchange (ETDEWEB)

    Liebsch, Mattes; Knoop, Jan-Frederik [Technische Univ. Dortmund (Germany)

    2013-07-01

    After teleseismic detection of a big underground explosion, during on-site inspections under the Comprehensive Nuclear Test-Ban Treaty (CTBT) weak seismic signals from aftershocks are to be detected. These, however, can be masked by soil vibrations which are caused by acoustic waves which couple to the ground. To analyse the coupling behaviour between acoustic waves and soil vibrations several experiments with different acoustic sources (helicopters, firecrackers, loudspeaker) were performed. Of special interest is the influence of surface waves, excited in a larger area around the sensor, which can superpose constructively at the position of the sensor and can increase the measured seismic signal. A better understanding of the acoustic-seismic coupling can be used to develop guidelines for seismic aftershock measurements, such as a suitable sensor setup, with the goal of reducing or even preventing disturbing signals to improve the performance of on-site inspections for the CTBT.

  13. Analysis of acoustic-seismic coupling behaviour for CTBT on-site inspection performance improvement

    International Nuclear Information System (INIS)

    After teleseismic detection of a big underground explosion, during on-site inspections under the Comprehensive Nuclear Test-Ban Treaty (CTBT) weak seismic signals from aftershocks are to be detected. These, however, can be masked by soil vibrations which are caused by acoustic waves which couple to the ground. To analyse the coupling behaviour between acoustic waves and soil vibrations several experiments with different acoustic sources (helicopters, firecrackers, loudspeaker) were performed. Of special interest is the influence of surface waves, excited in a larger area around the sensor, which can superpose constructively at the position of the sensor and can increase the measured seismic signal. A better understanding of the acoustic-seismic coupling can be used to develop guidelines for seismic aftershock measurements, such as a suitable sensor setup, with the goal of reducing or even preventing disturbing signals to improve the performance of on-site inspections for the CTBT.

  14. Chemosensitivity of radioresistant cells in the multicellular spheroids of A549 lung adenocarcinoma

    Directory of Open Access Journals (Sweden)

    Huang Gang

    2009-06-01

    Full Text Available Abstract Background The relapse of cancer after radiotherapy is a clinical knotty problem. Previous studies have demonstrated that the elevation of several factors is likely in some way to lead to the development of treatment tolerance, so it is necessary to further explore the problem of re-proliferated radioresistant cells to chemotherapeutic agents. In the present study, we aimed to investigate the chemosensitivity of radioresistant cells originated from the multicellular spheroids of A549 lung adenocarcinoma. Methods After irradiated with 25 Gy of 6 MV X-ray to A549 multicellular spheroids, whose 10th re-proliferated generations were employed as radioresistant cells, and the control groups were A549 parental cells and MCF7/VCR resistant cells. The chemo-sensitivity test was made by six kinds of chemotherapeutic drugs which were DDP, VDS, 5-Fu, HCP, MMC and ADM respectively, while verapamil (VPL was used as the reversal agent. Then the treatment effect was evaluated by MTT assay, and the multidrug resistant gene expressions of mdr1 and MRP were measured by RT-PCR. Results Both A549 parental cells and A549 derived radioresistant cells were resistant to DDP, but sensitive to VDS, 5-Fu, HCP, MMC and ADM. The inhibitory rates of VPL to these two types of cell were 98% and 25% respectively (P Mdr1/β2-MG and MRP/β2-MG of all A549 cells were about 0 and 0.7 respectively, and those of MCF7/VCR cells were 35 and 4.36. Conclusion The chemosensitivity of A549 radioresistant cells had not changed markedly, and the decreased sensitivity to VPL could not be explained by the gene expression of mdr1 and MRP. It is possible that the changes in the cell membrane and decreased proliferate ability might be attributed to the resistance. Unlike multidrug resistance induced by chemotherapy, VPL may be not an ideal reverser to radioresistant cells. Therefore, the new biological strategy needs to be developed to treat recurring radioresistant tumor in combination

  15. Chemosensitivity of irradiated resistant cells of multicellular spheroids in A549 lung adenocarcinoma

    International Nuclear Information System (INIS)

    Objective: To investigate the chemosensitivity of irradiated resistant cells of multicellular spheroids in A549 lung adenocarcinoma. Methods: The A549 irradiated resistant cells were the 10th regrowth generations after irradiated with 2.5 Gy of 6 MV X-ray, the control groups were A549 parent cells and MCFY/VCR resistant cells. The 6 kinds of chemotherapeutic drugs were DDP, VDS, 5-FU, HCP, MMC and ADM respectively, with verapamil (VPL) as reverse agent. The treatment effect was compared with MTT assay, and the multidrug resistant gene expressions of mdrl and MRP were measured with RT-PCR method. Results: A549 cells and irradiated resistant cells were resistant to DDP, but sensitivity to VDS,5-FU, HCP, MMC and ADM. The inhibitory rates of VPL to the above two cells were 98% and 25% respectively(P2-MG and MRP/β2-MG of all A549 cells were about 0 and 0.7 respectively, and those of MCFT/VCR cells were 35 and 4.36. Conclusion: The chemosensitivity of A549 irradiated resistant cells had not changed markedly, the decreased sensitivity to VPL could not be explained by the gene expression of mdrl and MRP. It is conferred that some kinds of changes in the cell membrane and decreased regrowth ability to result in resistance. Unlike multidrug resistance induced by chemotherapy, VPL may be not an ideal reverser to irradiated resistant cells. The new kinds of biological preparation should be sought to combine chemotherapy to treat recurring tumor with irradiated resistance. (authors)

  16. Glucose regulated protein 78 (GRP78) inhibits apoptosis and attentinutes chemosensitivity of gemcitabine in breast cancer cell via AKT/mitochondrial apoptotic pathway.

    Science.gov (United States)

    Xie, Jie; Tao, Zhong-Hua; Zhao, Jiang; Li, Ting; Wu, Zheng-Hua; Zhang, Jin-Feng; Zhang, Jian; Hu, Xi-Chun

    2016-06-01

    The underlying mechanism of gemcitabine resistance during breast cancer treatment remains unclear. Glucose regulated protein 78 (GRP78) frequently triggered by anticancer agents, was substantially elevated in gemcitabine resistant sublines. Ectopic expression of GRP78 changes gemcitabine chemosensitivity and apoptosis levels in breast cancer cells. Further experiments showed an involvement of caspase 9, not caspase 8, in gemcitabine resistance and GRP78-mediated chemosensitivity, suggesting that mitochondria apoptotic pathway was activated by GRP78. This finding was further supported by the observations of AKT activation, Bcl-2 increase, Bax and Bim decrease. Conclusively, GRP78 plays a vital role in gemcitabine resistance and clinical strategy to improve gemcitabine efficacy in breast cancer by manipulating GRP78 should be explored. PMID:27012209

  17. Augmenting the Antifungal Activity of an Oxidizing Agent with Kojic Acid: Control of Penicillium Strains Infecting Crops

    OpenAIRE

    Kim, Jong H.; Chan, Kathleen L.

    2014-01-01

    Oxidative treatment is one of the strategies for preventing Penicillium contamination in crops/foods. The antifungal efficacy of hydrogen peroxide (H2O2; oxidant) was investigated in Penicillium strains by using kojic acid (KA) as a chemosensitizing agent, which can enhance the susceptibility of pathogens to antifungal agents. Co-application of KA with H2O2 (chemosensitization) resulted in the enhancement of antifungal activity of either compound, when compared to the independent application ...

  18. Geophysics, Remote Sensing, and the Comprehensive Nuclear-Test-Ban Treaty (CTBT) Integrated Field Exercise 2014

    Science.gov (United States)

    Sussman, A. J.; Macleod, G.; Labak, P.; Malich, G.; Rowlands, A. P.; Craven, J.; Sweeney, J. J.; Chiappini, M.; Tuckwell, G.; Sankey, P.

    2015-12-01

    The Integrated Field Exercise of 2014 (IFE14) was an event held in the Hashemite Kingdom of Jordan (with concurrent activities in Austria) that tested the operational and technical capabilities of an on-site inspection (OSI) within the CTBT verification regime. During an OSI, up to 40 international inspectors will search an area for evidence of a nuclear explosion. Over 250 experts from ~50 countries were involved in IFE14 (the largest simulation of a real OSI to date) and worked from a number of different directions, such as the Exercise Management and Control Teams (which executed the scenario in which the exercise was played) and those participants performing as members of the Inspection Team (IT). One of the main objectives of IFE14 was to test and integrate Treaty allowed inspection techniques, including a number of geophysical and remote sensing methods. In order to develop a scenario in which the simulated exercise could be carried out, suites of physical features in the IFE14 inspection area were designed and engineered by the Scenario Task Force (STF) that the IT could detect by applying the geophysical and remote sensing inspection technologies, in addition to other techniques allowed by the CTBT. For example, in preparation for IFE14, the STF modeled a seismic triggering event that was provided to the IT to prompt them to detect and localize aftershocks in the vicinity of a possible explosion. Similarly, the STF planted shallow targets such as borehole casings and pipes for detection using other geophysical methods. In addition, airborne technologies, which included multi-spectral imaging, were deployed such that the IT could identify freshly exposed surfaces, imported materials, and other areas that had been subject to modification. This presentation will introduce the CTBT and OSI, explain the IFE14 in terms of the goals specific to geophysical and remote sensing methods, and show how both the preparation for and execution of IFE14 meet those goals.

  19. Synergy between von Hippel-Lindau and P53 contributes to chemosensitivity of clear cell renal cell carcinoma.

    Science.gov (United States)

    Zhao, Ziyi; Chen, Changjin; Lin, Junzhi; Zeng, Wentong; Zhao, Juan; Liang, Yindan; Tan, Qinrui; Yang, Chao; Li, Hui

    2016-09-01

    The von Hippel-Lindau tumor suppressor (VHL; E3 ubiquitin ligase gene) is frequently mutated or undetectable in clear cell renal cell carcinoma (CCRCC), and therefore these tumors are highly resistant to chemotherapeutic agents, including adriamycin (ADM) and sunitinib. A mutation in the tumor protein p53 (TP53) also leads to chemoresistance in tumors; however, in CCRCC, TP53 is frequently functional, yet the tumors remain highly insensitive to chemotherapy. This indicates the possibility of a synergistic effect of VHL and P53 in CCRCC. The present study aimed to detect the chemosensitivity of CCRCC. The expression of VHL in the MZ1257 cell line sensitized these cells to ADM and sunitinib, and a knockdown of VHL in the ACHN cells increased their chemoresistance. To confirm that VHL and P53 are both required for chemosensitivity, VHL and P53 were co‑expressed in 786‑O cells. The results of the functional antagonist assay (which assessed the IC50 values, i.e. the half maximal inhibitory concentration) confirmed that VHL and P53 act in synergy to promote chemosensitivity. Cell cycle arrest was measured by propidium iodide staining following treatment with ADM or sunitinib. Further analysis indicated that co‑expression of VHL and P53 inhibited cell proliferation by completely inhibiting the cell cycle at the G0/G1 phase, and promoted apoptosis following treatment with ADM or sunitinib. These findings demonstrated that VHL and P53 act synergistically in the regulation of cell proliferation and apoptosis in CCRCC. Overall, VHL and P53 have important roles in the regulation of cell proliferation and apoptosis in CCRCC. Furthermore, the regulatory role of VHL is dependant on the activation P53. PMID:27485825

  20. JAEA's recent activities related to Comprehensive Nuclear-Test-Ban Treaty (CTBT)

    International Nuclear Information System (INIS)

    The Comprehensive Nuclear-Test-Ban Treaty (CTBT), which bans any nuclear test at any place on the earth and provides the establishment of a system to monitor compliance by member states, was adopted at the United Nations in 1996. At present, more than 80% facilities (276 places) of the International Monitoring System (IMS) prescribed in the treaty have already been completed and have been substantially functioning as a global nuclear test monitoring. Of facilities installed in Japan, the Japan Atomic Energy Agency (JAEA) has established two radionuclide (RN) stations (Onna-son, Okinawa and Takasaki, Gunma) which monitor radionuclides and one radionuclide laboratory (Tokai, Ibaraki) for detail analyses of samples sent from RN stations all over the world, and JAEA is operating them as certified facilities meeting technical requirements for the Treaty monitoring. The National Data Center (NDC) installed in JAEA's site (Tokai, Ibaraki) receives the data from station network and analyzes them routinely. This paper describes current status of the verification regime and JAEA's recent activities related to the CTBT such as analysis and evaluation of the DPRK's 3rd nuclear test event. (author)

  1. Analysis of acoustic-seismic coupling for CTBT on-site inspection support

    International Nuclear Information System (INIS)

    The measurements of weak seismic signals, e.g. aftershock measurements during an on-site inspection for the Comprehensive Nuclear Test-Ban Treaty (CTBT), can be masked by man-made disturbances. These can be caused by airborne signals, like the noises of aircraft or helicopters, which couple to the ground and excite soil vibrations. We have measured sound pressure and corresponding soil vibrations caused by aircraft and by signals produced artificially with a speaker. Methods of acoustic deadening were applied to reduce the incident acoustic power locally. The influence on soil vibrations in different depths below the surface is investigated. The underlying question was whether the coupling of sound happens locally or soil vibrations created in a wide area around the sensor sum up to the total seismic signal. A better understanding of acoustic-seismic coupling can be used to develop guidelines for seismic aftershock measurements in order to improve the performance of on-site inspections for the CTBT.

  2. Role of EGFR mutations in lung cancers: prognosis and tumor chemosensitivity.

    Science.gov (United States)

    Suda, Kenichi; Mitsudomi, Tetsuya

    2015-08-01

    Lung cancers with an epidermal growth factor receptor (EGFR) gene mutation account for ~40 % of adenocarcinomas in East Asians and ~15 % of those in Caucasians and African Americans, which makes them one of the most common molecularly defined lung cancer subsets. The discriminative clinical and pathological features of lung cancers with EGFR mutations have been intensively studied, and the predictive role of an EGFR mutation for treatment with EGFR tyrosine kinase inhibitors (EGFR-TKIs) is well established. However, controversial issues remain regarding the clinical and therapeutic implications of EGFR mutations in lung cancers. These include the prognostic impact of the EGFR mutation, its predictive implication for successful treatment with anticancer agents other than EGFR-TKIs, appropriate cytotoxic agents for lung cancers with this mutation, and the chemosensitivity of EGFR-mutation-positive lung cancers after acquisition of resistance to EGFR-TKIs. In this review, we discuss these unanswered but important questions, referring to in vitro studies, basic research, retrospective analyses, and the results of phase III clinical trials. PMID:25983263

  3. Introduction of the Comprehensive Nuclear-Test-Ban Treaty (CTBT) and preparatory activities for its entry into force

    Energy Technology Data Exchange (ETDEWEB)

    Tani, Hiroshi [Japan Atomic Energy Research Inst., Mutsu Establishment, Mutsu, Aomori (Japan)

    2001-03-01

    The Comprehensive Nuclear-Test-Ban Treaty (CTBT) is a very important treaty, not only for Japan but also for the world, because it prohibits any nuclear weapon test explosion or any other nuclear explosion anywhere in the world. The treaty however will not enter into force until it has been signed and ratified by all the 44 states listed in Annex 2 to the treaty. Many efforts to facilitate the treaty's early entry into force are being done by many countries and many international organizations. As one of result of these efforts, a Preparatory Commission for the Comprehensive Nuclear-Test-Ban Treaty Organization had be established at a meeting of State Signatories on 19 November 1996, and the Commission started activities to establish global verification regime of the treaty and to prepare for its entry into force. Under the CTBT activities, the Japan Atomic Energy Research Institute (JAERI) is expected to play an important role as supporter for the Japanese Government, especially in a field of an International Monitoring System (IMS). However, there is no appropriate guide book on the CTBT for JAERI staff at present. This report provides some introduction of the CTBT regime and preparatory activities for its entry into force. Only open source information is used for making the report. If anyone need more detail information, it should be asked to contact competent authorities. (author)

  4. Introduction of the Comprehensive Nuclear-Test-Ban Treaty (CTBT) and preparatory activities for its entry into force

    International Nuclear Information System (INIS)

    The Comprehensive Nuclear-Test-Ban Treaty (CTBT) is a very important treaty, not only for Japan but also for the world, because it prohibits any nuclear weapon test explosion or any other nuclear explosion anywhere in the world. The treaty however will not enter into force until it has been signed and ratified by all the 44 states listed in Annex 2 to the treaty. Many efforts to facilitate the treaty's early entry into force are being done by many countries and many international organizations. As one of result of these efforts, a Preparatory Commission for the Comprehensive Nuclear-Test-Ban Treaty Organization had be established at a meeting of State Signatories on 19 November 1996, and the Commission started activities to establish global verification regime of the treaty and to prepare for its entry into force. Under the CTBT activities, the Japan Atomic Energy Research Institute (JAERI) is expected to play an important role as supporter for the Japanese Government, especially in a field of an International Monitoring System (IMS). However, there is no appropriate guide book on the CTBT for JAERI staff at present. This report provides some introduction of the CTBT regime and preparatory activities for its entry into force. Only open source information is used for making the report. If anyone need more detail information, it should be asked to contact competent authorities. (author)

  5. Seismic Characterization of Coal-Mining Seismicity in Utah for CTBT Monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Arabasz, W J; Pechmann, J C

    2001-03-01

    Underground coal mining (down to {approx}0.75 km depth) in the contiguous Wasatch Plateau (WP) and Book Cliffs (BC) mining districts of east-central Utah induces abundant seismicity that is monitored by the University of Utah regional seismic network. This report presents the results of a systematic characterization of mining seismicity (magnitude {le} 4.2) in the WP-BC region from January 1978 to June 2000-together with an evaluation of three seismic events (magnitude {le} 4.3) associated with underground trona mining in southwestern Wyoming during January-August 2000. (Unless specified otherwise, magnitude implies Richter local magnitude, M{sub L}.) The University of Utah Seismograph Stations (UUSS) undertook this cooperative project to assist the University of California Lawrence Livermore National Laboratory (LLNL) in research and development relating to monitoring the Comprehensive Test Ban Treaty (CTBT). The project, which formally began February 28, 1998, and ended September 1, 2000, had three basic objectives: (1) Strategically install a three-component broadband digital seismic station in the WP-BC region to ensure the continuous recording of high-quality waveform data to meet the long-term needs of LLNL, UUSS, and other interested parties, including the international CTBT community. (2) Determine source mechanisms--to the extent that available source data and resources allowed--for comparative seismic characterization of stress release in mines versus earthquakes in the WP-BC study region. (3) Gather and report to LLNL local information on mine operations and associated seismicity, including ''ground truth'' for significant events. Following guidance from LLNL's Technical Representative, the focus of Objective 2 was changed slightly to place emphasis on three mining-related events that occurred in and near the study area after the original work plan had been made, thus posing new targets of opportunity. These included: a magnitude

  6. Experiences as an observer of the CTBT on-site-inspection exercise DE07 in Chernobyl

    International Nuclear Information System (INIS)

    The directed exercise DE07 took place in the Chernobyl exclusion zone in the Ukraine from 4. June 2007 to 14. June 2007. The aim of the exercise was to train several aspects of an on-site-inspection (OSI) to provide evidence of a forbidden nuclear weapons test in the context of the preparation of the comprehensive test ban treaty (CTBT). I had the opportunity to join the exercise as an observer. 25 experts from 22 state parties took part in the exercise. In addition 4 observers from 4 countries participated. The aim of the directed exercise was to measure radioactivity levels in a simulated inspection area and to identify the nuclides. The following aspects of an OSI were trained: carborne and airborne gamma survey; environmental sampling and analysis in a field laboratory; safety of work, personal protection and decontamination; communication and navigation in the field; data preparation and data handling

  7. Present state of JAERI National Data Center (NDC) for CTBT verification

    International Nuclear Information System (INIS)

    The Japan Atomic Energy Research Institute (JAERI) has developed the National Data Center (NDC) for radionuclide as part of the international monitoring regime related to the Comprehensive Nuclear-Test-Ban Treaty (CTBT). JAERI NDC already started to input gamma-ray spectrum data obtained from several International Monitoring System (IMS) stations into a database. Data analysis reports made by the International Data Center (IDC) are also stored in the database. Some software tools are under development for the NDC's independent analysis such as investigation of existence of the radionuclides derived from nuclear explosion and presumptive analysis of source location of radionuclide release. The NDC system will also be able to post IMS data and analysis results to the authorized users on the Internet. This paper presents the role, current state of system development and future plan of JAERI NDC. (author)

  8. Engineering upgrades to the Radionuclide Aerosol Sampler/Analyzer for the CTBT International Monitoring System

    International Nuclear Information System (INIS)

    The Radionuclide Aerosol Sampler/Analyzer (RASA) is an automated collection and analysis system designed for aerosol radionuclide monitoring for the Comprehensive Nuclear-Test-Ban Treaty (CTBT). The advantages of an automated system include minimal need for human intervention and consistent analytical data. However, maintainability and down time issues threaten this utility, even for systems with over 90 % data availability. Engineering upgrades to the RASA are currently being pursued to address these issues, as well as measures relevant to technical lessons learned from the Fukushima nuclear power plant event. Current work includes a new automation control unit and other potential improvements such as alternative detector cooling and sampling options. This paper presents the current state of upgrades and improvements under investigation. (author)

  9. Association of telomerase activity with radio- and chemosensitivity of neuroblastomas

    International Nuclear Information System (INIS)

    Telomerase activity compensates shortening of telomeres during cell division and enables cancer cells to escape senescent processes. It is also supposed, that telomerase is associated with radio- and chemoresistance. In the here described study we systematically investigated the influence of telomerase activity (TA) and telomere length on the outcome of radio- and chemotherapy in neuroblastoma. We studied the effects on dominant negative (DN) mutant, wild type (WT) of the telomerase catalytic unit (hTERT) using neuroblastoma cell lines. The cells were irradiated with 60Co and treated with doxorubicin, etoposide, cisplatin and ifosfamide, respectively. Viability was determined by MTS/MTT-test and the GI50 was calculated. Telomere length was measured by southernblot analysis and TA by Trap-Assay. Compared to the hTERT expressing cells the dominant negative cells showed increased radiosensitivity with decreased telomere length. Independent of telomere length, telomerase negative cells are significantly more sensitive to irradiation. The effect of TA knock-down or overexpression on chemosensitivity were dependent on TA, the anticancer drug, and the chemosensitivity of the maternal cell line. Our results supported the concept of telomerase inhibition as an antiproliferative treatment approach in neuroblastomas. Telomerase inhibition increases the outcome of radiotherapy while in combination with chemotherapy the outcome depends on drug- and cell line and can be additive/synergistic or antagonistic. High telomerase activity is one distinct cancer stem cell feature and the here described cellular constructs in combination with stem cell markers like CD133, Aldehyddehydrogenase-1 (ALDH-1) or Side population (SP) may help to investigate the impact of telomerase activity on cancer stem cell survival under therapy

  10. Chemosensitization of cancer cells by siRNA using targeted nanogel delivery

    International Nuclear Information System (INIS)

    Chemoresistance is a major obstacle in cancer treatment. Targeted therapies that enhance cancer cell sensitivity to chemotherapeutic agents have the potential to increase drug efficacy while reducing toxic effects on untargeted cells. Targeted cancer therapy by RNA interference (RNAi) is a relatively new approach that can be used to reversibly silence genes in vivo by selectively targeting genes such as the epidermal growth factor receptor (EGFR), which has been shown to increase the sensitivity of cancer cells to taxane chemotherapy. However, delivery represents the main hurdle for the broad development of RNAi therapeutics. We report here the use of core/shell hydrogel nanoparticles (nanogels) functionalized with peptides that specially target the EphA2 receptor to deliver small interfering RNAs (siRNAs) targeting EGFR. Expression of EGFR was determined by immunoblotting, and the effect of decreased EGFR expression on chemosensitization of ovarian cancer cells after siRNA delivery was investigated. Treatment of EphA2 positive Hey cells with siRNA-loaded, peptide-targeted nanogels decreased EGFR expression levels and significantly increased the sensitivity of this cell line to docetaxel (P < 0.05). Nanogel treatment of SK-OV-3 cells, which are negative for EphA2 expression, failed to reduce EGFR levels and did not increase docetaxel sensitivity (P > 0.05). This study suggests that targeted delivery of siRNAs by nanogels may be a promising strategy to increase the efficacy of chemotherapy drugs for the treatment of ovarian cancer. In addition, EphA2 is a viable target for therapeutic delivery, and the siRNAs are effectively protected by the nanogel carrier, overcoming the poor stability and uptake that has hindered clinical advancement of therapeutic siRNAs

  11. In Vitro Chemosensitivity Testing of Primary and Recurrent Breast Carcinomas and Its Clinical Significance

    Institute of Scientific and Technical Information of China (English)

    Zhi LI; Haiping SONG; Wenshan HE; Yuan TIAN; Tao HUANG

    2008-01-01

    In this study, in vitro chemosensitivity testing was conducted on primary cultured breast cancer cells from 96 patients with breast cancer, and the results showed that the cells from a few patients with primary breast cancer developed multidrug resistance (MDR) prior to the first chemotherapy exposure. All the cells from the recurrent cancer patients had MDR. The findings suggested that patients having MDR would benefit from high-dose chemotherapy (HDC) regimens. In vitro chemosensitivity screening, which was aimed at improving the therapeutic efficacy and minimizing side effects, helps in choosing individualized treatment for breast cancer.

  12. Investigation of CTBT OSI Radionuclide Techniques at the DILUTED WATERS Nuclear Test Site

    Energy Technology Data Exchange (ETDEWEB)

    Baciak, James E.; Milbrath, Brian D.; Detwiler, Rebecca S.; Kirkham, Randy R.; Keillor, Martin E.; Lepel, Elwood A.; Seifert, Allen; Emer, Dudley; Floyd, Michael

    2012-11-01

    Under the Comprehensive Nuclear-Test-Ban Treaty (CTBT), a verification regime that includes the ability to conduct an On-Site Inspection (OSI) will be established. The Treaty allows for an OSI to include many techniques, including the radionuclide techniques of gamma radiation surveying and spectrometry and environmental sampling and analysis. Such radioactivity detection techniques can provide the “smoking gun” evidence that a nuclear test has occurred through the detection and quantification of indicative recent fission products. An OSI faces restrictions in time and manpower, as dictated by the Treaty; not to mention possible logistics difficulties due to the location and climate of the suspected explosion site. It is thus necessary to have a good understanding of the possible source term an OSI will encounter and the proper techniques that will be necessary for an effective OSI regime. One of the challenges during an OSI is to locate radioactive debris that has escaped an underground nuclear explosion (UNE) and settled on the surface near and downwind of ground zero. To support the understanding and selection of sampling and survey techniques for use in an OSI, we are currently designing an experiment, the Particulate Release Experiment (PRex), to simulate a small-scale vent from an underground nuclear explosion. PRex will occur at the Nevada National Security Site (NNSS). The project is conducted under the National Center for Nuclear Security (NCNS) funded by the National Nuclear Security Agency (NNSA). Prior to the release experiment, scheduled for Spring of 2013, the project scheduled a number of activities at the NNSS to prepare for the release experiment as well as to utilize the nuclear testing past of the NNSS for the development of OSI techniques for CTBT. One such activity—the focus of this report—was a survey and sampling campaign at the site of an old UNE that vented: DILUTED WATERS. Activities at DILUTED WATERS included vehicle-based survey

  13. Ad hoc algorithms and methodologies for the radionuclide CTBT treaty verification

    International Nuclear Information System (INIS)

    Full text: The 'Preparatory Commission for the Comprehensive Nuclear-Test-Ban Treaty Organization' is the international organization establishing the global verification system under the CTBT, which bans all nuclear weapon test explosion or any other nuclear explosion. The verification system includes the International Monitoring System (IMS), a global network of 321 monitoring stations (radionuclide technologies: particulate and noble gases; waveform technologies: seismic, hydro acoustic and infrasound), a communications infrastructure, an International Data Centre (hereinafter referred to as the IDC) and the capability to carry out on-site inspections. To verify the treaty, the radionuclide monitoring needs to review data coming daily from 80 particulate and 40 noble gas stations. The big amount of data to review and the specific and sensitive task in the treaty verification led to the development of new methods and algorithms to help the human analysis reducing the reviewing time and enhancing the quality of the results. Specific science for gamma spectroscopy has been involved and applied in ad hoc algorithms to make the automatic screening faster, consistent and scientific sound, moreover a set of special tools have been provided to the analysts to review and correct identify the daily findings. A whole package containing all those needs and algorithms has been developed at the CTBTO and is called Simulated Assisted Interactive Nuclide-review Tool (SAINT). The two major peculiarities of the SAINT are: A total new approach of gamma peak finding that enhances drastically the capability to detect very small signals. The usage of Monte Carlo simulated spectra for the correct Nuclide Identification A good spectrum baseline calculation is essential for the application of these ad-hoc calculations. The algorithm named 'lawnmower' has been developed at the IDC. (author)

  14. Targeting the Mitochondrial Respiratory Chain of Cryptococcus through Antifungal Chemosensitization: A Model for Control of Non-Fermentative Pathogens

    Directory of Open Access Journals (Sweden)

    Kathleen L. Chan

    2013-07-01

    Full Text Available Enhanced control of species of Cryptococcus, non-fermentative yeast pathogens, was achieved by chemosensitization through co-application of certain compounds with a conventional antimicrobial drug. The species of Cryptococcus tested showed higher sensitivity to mitochondrial respiratory chain (MRC inhibition compared to species of Candida. This higher sensitivity results from the inability of Cryptococcus to generate cellular energy through fermentation. To heighten disruption of cellular MRC, octyl gallate (OG or 2,3-dihydroxybenzaldehyde (2,3-DHBA, phenolic compounds inhibiting mitochondrial functions, were selected as chemosensitizers to pyraclostrobin (PCS; an inhibitor of complex III of MRC. The cryptococci were more susceptible to the chemosensitization (i.e., PCS + OG or 2,3-DHBA than the Candida with all Cryptococcus strains tested being sensitive to this chemosensitization. Alternatively, only few of the Candida strains showed sensitivity. OG possessed higher chemosensitizing potency than 2,3-DHBA, where the concentration of OG required with the drug to achieve chemosensitizing synergism was much lower than that required of 2,3-DHBA. Bioassays with gene deletion mutants of the model yeast Saccharomyces cerevisiae showed that OG or 2,3-DHBA affect different cellular targets. These assays revealed mitochondrial superoxide dismutase or glutathione homeostasis plays a relatively greater role in fungal tolerance to 2,3-DHBA or OG, respectively. These findings show that application of chemosensitizing compounds that augment MRC debilitation is a promising strategy to antifungal control against yeast pathogens.

  15. Prohibiting and Preventing Nuclear Explosions: Background Information for Parliamentarians on the Comprehensive Nuclear-Test-Ban Treaty (CTBT)

    International Nuclear Information System (INIS)

    The object and purpose of the CTBT is to ban comprehensively nuclear weapon test explosions and any other nuclear explosion in any environment in an effectively verifiable manner. The CTBT aims at eliminating nuclear weapons by constraining the development and qualitative improvement of new or more advanced nuclear weapons. It plays a crucial role in the prevention of nuclear proliferation and in nuclear disarmament, thus contributing to a safer and more secure world. When the Treaty enters into force it will establish a treaty-implementing body (the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO)), including an on-site inspection mechanism and confidence-building measures as well as an International Monitoring System (IMS) and International Data Centre (IDC). The IMS and IDC are already being created and are being provisionally operated during the preparatory phase by the Preparatory Commission for the CTBTO and its Provisional Technical Secretariat in Vienna. Seismic, hydroacoustic, infrasound and radionuclide data are collected through the stations of the IMS and transmitted to Member States via the IDC. The IDC also processes the raw data received from the stations to derive objective products and services which will support the Treaty verification responsibilities. If the collected and analysed data indicate an ambiguous event, States may address concerns about possible noncompliance with the Treaty through a consultation and clarification process after it enters into force and may request an on-site inspection by the CTBTO.

  16. NG09 And CTBT On-Site Inspection Noble Gas Sampling and Analysis Requirements

    Science.gov (United States)

    Carrigan, Charles R.; Tanaka, Junichi

    2010-05-01

    A provision of the Comprehensive Test Ban Treaty (CTBT) allows on-site inspections (OSIs) of suspect nuclear sites to determine if the occurrence of a detected event is nuclear in origin. For an underground nuclear explosion (UNE), the potential success of an OSI depends significantly on the containment scenario of the alleged event as well as the application of air and soil-gas radionuclide sampling techniques in a manner that takes into account both the suspect site geology and the gas transport physics. UNE scenarios may be broadly divided into categories involving the level of containment. The simplest to detect is a UNE that vents a significant portion of its radionuclide inventory and is readily detectable at distance by the International Monitoring System (IMS). The most well contained subsurface events will only be detectable during an OSI. In such cases, 37 Ar and radioactive xenon cavity gases may reach the surface through either "micro-seepage" or the barometric pumping process and only the careful siting of sampling locations, timing of sampling and application of the most site-appropriate atmospheric and soil-gas capturing methods will result in a confirmatory signal. The OSI noble gas field tests NG09 was recently held in Stupava, Slovakia to consider, in addition to other field sampling and analysis techniques, drilling and subsurface noble gas extraction methods that might be applied during an OSI. One of the experiments focused on challenges to soil-gas sampling near the soil-atmosphere interface. During withdrawal of soil gas from shallow, subsurface sample points, atmospheric dilution of the sample and the potential for introduction of unwanted atmospheric gases were considered. Tests were designed to evaluate surface infiltration and the ability of inflatable well-packers to seal out atmospheric gases during sample acquisition. We discuss these tests along with some model-based predictions regarding infiltration under different near

  17. Systematically characterizing and prioritizing chemosensitivity related gene based on Gene Ontology and protein interaction network

    Directory of Open Access Journals (Sweden)

    Chen Xin

    2012-10-01

    Full Text Available Abstract Background The identification of genes that predict in vitro cellular chemosensitivity of cancer cells is of great importance. Chemosensitivity related genes (CRGs have been widely utilized to guide clinical and cancer chemotherapy decisions. In addition, CRGs potentially share functional characteristics and network features in protein interaction networks (PPIN. Methods In this study, we proposed a method to identify CRGs based on Gene Ontology (GO and PPIN. Firstly, we documented 150 pairs of drug-CCRG (curated chemosensitivity related gene from 492 published papers. Secondly, we characterized CCRGs from the perspective of GO and PPIN. Thirdly, we prioritized CRGs based on CCRGs’ GO and network characteristics. Lastly, we evaluated the performance of the proposed method. Results We found that CCRG enriched GO terms were most often related to chemosensitivity and exhibited higher similarity scores compared to randomly selected genes. Moreover, CCRGs played key roles in maintaining the connectivity and controlling the information flow of PPINs. We then prioritized CRGs using CCRG enriched GO terms and CCRG network characteristics in order to obtain a database of predicted drug-CRGs that included 53 CRGs, 32 of which have been reported to affect susceptibility to drugs. Our proposed method identifies a greater number of drug-CCRGs, and drug-CCRGs are much more significantly enriched in predicted drug-CRGs, compared to a method based on the correlation of gene expression and drug activity. The mean area under ROC curve (AUC for our method is 65.2%, whereas that for the traditional method is 55.2%. Conclusions Our method not only identifies CRGs with expression patterns strongly correlated with drug activity, but also identifies CRGs in which expression is weakly correlated with drug activity. This study provides the framework for the identification of signatures that predict in vitro cellular chemosensitivity and offers a valuable

  18. Targeting the oxidative stress response system of fungi with safe, redox-potent chemosensitizing agents

    Science.gov (United States)

    One mode of action of the antimycotics amphotericin B (AMB) or itraconazole (ITZ) against filamentous fungi involves cellular oxidative stress response. Aspergillus fumigatus sakA', a mitogen-activated protein kinase (MAPK) gene deletion mutant in the antioxidation system, was more sensitive to AMB ...

  19. Polycyclic amines as chloroquine resistance modulating agents in Plasmodium falciparum.

    Science.gov (United States)

    Joubert, Jacques; Kapp, Erika; Taylor, Dale; Smith, Peter J; Malan, Sarel F

    2016-02-15

    Pentacycloundecylamines (PCUs) and adamantane amines, such as NGP1-01 (1) and amantadine, have shown significant channel blocking activities. They are postulated to act as chemosensitizers and circumvent the resistance of the plasmodia parasite against chloroquine (CQ) by inhibiting the p-glycoprotein efflux pump and enabling the accumulation of CQ inside the parasite digestive vacuole. Twelve polycyclic amines containing either a PCU or adamantane amine moiety conjugated to different aromatic functionalities through various tethered linkers were selected based on their channel blocking abilities and evaluated as potential chemosensitizers. Compounds 2, 4, 5 and 10 showed significant voltage-gated calcium channel (VGCC) blocking ability (IC50=0.27-35 μM) and were able to alter the CQ IC50 in differing degrees (45-81%) in the multidrug resistant Plasmodium falciparum Dd2 isolate. Among them, the PCU-dansyl amine compound (4) displayed the best potential to act as a chemosensitizer against the Dd2 strain at a 1 μM concentration (RMI=0.19) while displaying moderate antiplasmodial activity (Dd2 IC50=6.25 μM) and low in vitro cytotoxicity against a mammalian cell line (CHO, IC50=119 μM). Compounds 2 and 10 also showed some promising chemosensitizing abilities (RMI=0.36 and 0.35 respectively). A direct correlation was found between the VGCC blocking ability of these polycyclic amines and their capacity to act as CQ resistance modulating agents. PMID:26832222

  20. Factors associated with the preincubation effect of hypoxic cell sensitizers in vitro and their possible implications in chemosensitization

    International Nuclear Information System (INIS)

    The enhancement of melphalan toxicity was observed by preincubation of V-79-379A cells in spinner culture with multiple doses of misonidazole (miso) or SR-2508 under hypoxic conditions. Chemosensitization was shown to be a function of sensitizer concentration and duration of exposure to the alkylating agent. Cells preincubated with miso not only had lower levels of nonprotein thiols, but also were shown to have altered levels of intracellular calcium and a lower threshold to oxidative stress as measured by toxicity to cysteamine or H2O2. Preincubated cells, hypoxic cells, and cells receiving moderate hyperthermia (42.50C for 3 hr) all showed increased sensitivity to either cysteamine or H2O2. The increased killing of preincubated cells by cysteamine was shown to be similar to that of H2O2, and the dramatic reduction of cysteamine toxicity by catalase indicated H2O2 was the major reaction associated with this effect. These results indicate that preincubated cells exhibit a variety of biological effects that may significantly influence their response to further treatment with drugs or radiation, especially where peroxidative and free radical mechanisms are involved

  1. Activity of mevalonate pathway inhibitors against breast and ovarian cancers in the ATP-based tumour chemosensitivity assay

    International Nuclear Information System (INIS)

    Previous data suggest that lipophilic statins such as fluvastatin and N-bisphosphonates such as zoledronic acid, both inhibitors of the mevalonate metabolic pathway, have anti-cancer effects in vitro and in patients. We have examined the effect of fluvastatin alone and in combination with zoledronic acid in the ATP-based tumour chemosensitivity assay (ATP-TCA) for effects on breast and ovarian cancer tumour-derived cells. Both zoledronic acid and fluvastatin showed activity in the ATP-TCA against breast and ovarian cancer, though fluvastatin alone was less active, particularly against breast cancer. The combination of zoledronic acid and fluvastatin was more active than either single agent in the ATP-TCA with some synergy against breast and ovarian cancer tumour-derived cells. Sequential drug experiments showed that pre-treatment of ovarian tumour cells with fluvastatin resulted in decreased sensitivity to zoledronic acid. Addition of mevalonate pathway components with zoledronic acid with or without fluvastatin showed little effect, while mevalonate did reduced inhibition due to fluvastatin. These data suggest that the combination of zoledronic acid and fluvastatin may have activity against breast and ovarian cancer based on direct anti-cancer cell effects. A clinical trial to test this is in preparation

  2. Water extract from Pleurotus pulmonarius with antioxidant activity exerts in vivo chemoprophylaxis and chemosensitization for liver cancer.

    Science.gov (United States)

    Xu, Wen Wen; Li, Bin; Lai, Emily Tsz Ching; Chen, Lei; Huang, Jim Jun Hui; Cheung, Annie Lai Man; Cheung, Peter Chi Keung

    2014-01-01

    Chemoprophylaxis and chemosensitization are promising strategies to combat human cancers. Natural antioxidant agents show great promise in cancer therapy, and the use of edible mushrooms against cancer is receiving more interest globally. In this study, the radical scavenging activities including diphenyl-1-picrylhydrazyl, superoxide anion radical, hydroxyl radical, and hydrogen peroxide were compared among hot water extracts from 3 edible mushrooms, among which Pleurotus pulmonarius (Pp) possessed the highest antioxidant potential. Oral administration of Pp 2 wk in advance could markedly inhibit the incidence and size of tumor (Huh7 liver cancer cells) with an inhibition rate of 93.1% in nude mice. No obvious side effect was observed in the Pp-treated mice as indicated by their body weight and histological analysis of major organs. The cancer prevention by Pp treatment might be explained by the inhibition of cancer cell proliferation indicated by reduction of ki-67 staining and the inactivation of phosphoinositide 3-kinase (PI3K)/AKT signaling pathway in the Pp-treated mice. Furthermore, a significant synergistic effect was observed when the mice were treated with a combination of low dose of cisplatin and Pp. Taken together, these results suggest the potential application of Pp as an adjuvant in the chemotherapy of liver cancer. PMID:25072857

  3. Differential effects of arsenic trioxide on chemosensitization in human hepatic tumor and stellate cell lines

    International Nuclear Information System (INIS)

    Crosstalk between malignant hepatocytes and the surrounding peritumoral stroma is a key modulator of hepatocarcinogenesis and therapeutic resistance. To examine the chemotherapy resistance of these two cellular compartments in vitro, we evaluated a well-established hepatic tumor cell line, HepG2, and an adult hepatic stellate cell line, LX2. The aim was to compare the chemosensitization potential of arsenic trioxide (ATO) in combination with sorafenib or fluorouracil (5-FU), in both hepatic tumor cells and stromal cells. Cytotoxicity of ATO, 5-FU, and sorafenib, alone and in combination against HepG2 cells and LX2 cells was measured by an automated high throughput cell-based proliferation assay. Changes in survival and apoptotic signaling pathways were analyzed by flow cytometry and western blot. Gene expression of the 5-FU metabolic enzyme, thymidylate synthase, was analyzed by real time PCR. Both HepG2 and LX2 cell lines were susceptible to single agent sorafenib and ATO at 24 hr (ATO IC50: 5.3 μM in LX2; 32.7 μM in HepG2; Sorafenib IC50: 11.8 μM in LX2; 9.9 μM in HepG2). In contrast, 5-FU cytotoxicity required higher concentrations and prolonged (48–72 hr) drug exposure. Concurrent ATO and 5-FU treatment of HepG2 cells was synergistic, leading to increased cytotoxicity due in part to modulation of thymidylate synthase levels by ATO. Concurrent ATO and sorafenib treatment showed a trend towards increased HepG2 cytotoxicity, possibly due to a significant decrease in MAPK activation in comparison to treatment with ATO alone. ATO differentially sensitizes hepatic tumor cells and adult hepatic stellate cells to 5-FU and sorafenib. Given the importance of both of these cell types in hepatocarcinogenesis, these data have implications for the rational development of anti-cancer therapy combinations for the treatment of hepatocellular carcinoma (HCC)

  4. Statement to the Third Conference on Facilitating the Entry into Force of the Comprehensive Nuclear-Test-Ban Treaty (CTBT). Vienna, 3 September 2003

    International Nuclear Information System (INIS)

    Full text: The Third Conference on Facilitating the Entry into Force of the Comprehensive Nuclear-Test-Ban Treaty (CTBT) is being held at a time of major challenges to the nuclear arms control and disarmament regime. A verified, permanent, global ban on all types of nuclear explosive tests has been a key item on the international security agenda for nearly half a century. More than 2,000 nuclear explosive detonations have taken place since 1945, with the most recent ones in 1998. The CTBT has been characterized as the longest sought, hardest fought prize in the history of arms control. The Treaty, when implemented, will prohibit all nuclear explosions, in all environments, for all time. It will curb the development and testing of new, more advanced and more dangerous nuclear weapons, and will limit the possibilities for further nuclear proliferation. The Treaty will lead to the establishment of a comprehensive International Monitoring System to provide independent, impartial verification of compliance. The CTBT, along with the Treaty on the Non-Proliferation of Nuclear Weapons (NPT), and a future Treaty Banning the Production of Fissile Material for Nuclear Weapons and Other Nuclear Explosive Devices (FMCT), forms an essential element of a network of negotiated, global treaties that will strengthen international efforts to prevent the further spread of nuclear weapons and to promote nuclear disarmament leading in time hopefully to a world without nuclear weapons. In the meantime, with the early entry into force of the CTBT, it would indeed be a significant achievement if this new century were to remain free of any nuclear test explosions. In this context, I encourage all signatory States to ratify the CTBT, and all those States that have yet to sign to do so and to ratify the Treaty, as soon as possible - so that another crucial pillar can be raised to support the edifice of global nuclear non-proliferation and nuclear disarmament norms. (IAEA)

  5. ABC transporters as multidrug resistance mechanisms and the development of chemosensitizers for their reversal

    Directory of Open Access Journals (Sweden)

    Choi Cheol-Hee

    2005-10-01

    Full Text Available Abstract One of the major problems related with anticancer chemotherapy is resistance against anticancer drugs. The ATP-binding cassette (ABC transporters are a family of transporter proteins that are responsible for drug resistance and a low bioavailability of drugs by pumping a variety of drugs out cells at the expense of ATP hydrolysis. One strategy for reversal of the resistance of tumor cells expressing ABC transporters is combined use of anticancer drugs with chemosensitizers. In this review, the physiological functions and structures of ABC transporters, and the development of chemosensitizers are described focusing on well-known proteins including P-glycoprotein, multidrug resistance associated protein, and breast cancer resistance protein.

  6. 20(S)-Protopanaxadiol (PPD) analogues chemosensitize multidrug-resistant cancer cells to clinical anticancer drugs.

    Science.gov (United States)

    Liu, Junhua; Wang, Xu; Liu, Peng; Deng, Rongxin; Lei, Min; Chen, Wantao; Hu, Lihong

    2013-07-15

    Novel 20(S)-protopanoxadiol (PPD) analogues were designed, synthesized, and evaluated for the chemosensitizing activity against a multidrug resistant (MDR) cell line (KBvcr) overexpressing P-glycoprotein (P-gp). Structure-activity relationship analysis showed that aromatic substituted aliphatic amine at the 24-positions (groups V) effectively and significantly sensitized P-gp overexpressing multidrug resistant (MDR) cells to anticancer drugs, such as docetaxel (DOC), vincristine (VCR), and adriamycin (ADM). PPD derivatives 12 and 18 showed 1.3-2.6 times more effective reversal ability than verapamil (VER) for DOC and VCR. Importantly, no cytotoxicity was observed by the active PPD analogues (5μM) against both non-MDR and MDR cells, suggesting that PPD analogues serve as novel lead compounds toward a potent and safe resistance modulator. Moreover, a preliminary mechanism study demonstrated that the chemosensitizing activity of PPD analogues results from inhibition of P-glycoprotein (P-gp) overexpressed in MDR cancer cells. PMID:23683834

  7. CD80 antigen expression as a predictor of ex vivo chemosensitivity in chronic lymphocytic leukemia.

    Science.gov (United States)

    Kivekäs, Ilkka; Hulkkonen, Janne; Hurme, Mikko; Vilpo, Leena; Vilpo, Juhani

    2002-05-01

    We investigated the correlation between expression of 31 surface membrane antigens and chemosensitivity of peripheral blood mononuclear cells from 36 patients with CLL. The sensitivity of CLL cells to nine drugs (2'-chlorodeoxyadenosine, cisplatin, chlorambucil, cyclosporin A, doxorubicin, fludarabine, prednisolone, verapamil and vincristine) and two types of irradiation (gamma and UV-irradiation) was determined from dose-response curves of 4-day cultures ex vivo. The results indicated that the CLL cases responding to purine analogs (2'-chlorodeoxyadenosine and fludarabine) can be identified according to CD80 expression: all resistant cases had low or negative CD80 expression. No other correlations were revealed. CD80 may be a surrogate chemosensitivity marker for purine analogs. PMID:11916516

  8. Respiratory control in the newborn : Central chemosensitivity, neuropeptides and nicotinic effects

    OpenAIRE

    Wickström, Ronny

    2002-01-01

    Breathing is regulated by a complex network of neurons located mainly in the brainstem. For the newborn, it is critical for survival that a continuous respiration is established after birth. However, the regulation of respiration also undergoes maturation in the postnatal period. This thesis focuses on some of the systems modulating respiration that may be of great importance for the newborn: central (C02) chemosensitivity and the neuropeptides substance P (SP) and galanin ...

  9. EFFECTS OF SIMULATED MICROGRAVITY ON PROLIFERATION AND CHEMOSENSITIVITY IN MALIGNANT GLIOMA CELLS

    OpenAIRE

    Kurisu, Kaoru; Takeda, Masaaki; Okazaki, Takahito; Kawahara, Yumi; Yuge, Lous

    2014-01-01

    BACKGROUND: Everything on the earth can be affected by gravity of the earth. So, microgravity, as small as 10 minus 3 times G, can make some effects to the growth or maturation of cells. Under this hypothesis we examined cell proliferation and chemosensitivity after exposure to simulated microgravity using the malignant glioma cell lines. We exposed cells to simulated microgravity using a 3D-clinostat which is a type of rotating culture system that has two independent axes of rotation to disp...

  10. Increased leucine-rich repeats and immunoglobulin- like domains 1 expression enhances chemosensitivity in glioma

    Institute of Scientific and Technical Information of China (English)

    Baohui Liu; Shenqi Zhang; Dong Ruan; Xiaonan Zhu; Zhentao Guo; Huimin Dong; Mingmin Yan; Qianxue Chen; Daofeng Tian; Liquan Wu; Junmin Wang; Qiang Cai; Heng Shen; Baowei Ji; Long Wang

    2011-01-01

    Leucine-rich repeats and immunoglobulin-like domains 1 (LRIG1) is an anti-oncogene.LRIG1 is correlated with Bcl-2 in ependymomas.Decreased Bcl-2 and manganese superoxide dismutase expression can improve the chemosensitivity of glioma.In the present study, a tissue microarray of human brain astrocytomas was constructed.To investigate the relationship of LRIG1 with Bcl-2 and manganese superoxide dismutase, LRIG1, Bcl-2 and manganese superoxide dismutase expression in our tissue microarray was determined using immunohistochemistry.In addition, we constructed the LRIG1-U251 cell line, and its responses to doxorubicin and temozolomide were detected using the MTT assay.Results showed that LRIG1 expression was significantly negatively correlated with Bcl-2 and manganese superoxide dismutase expression in glioma.Also, proliferation of LRIG1-U251 cells exposed to doxorubicin or temozolomide was significantly inhibited, i.e.in the LRIG1-U251 cell line, the chemosensitivity to doxorubicin and temozolomide was increased.This indicates that increased LRIG1 expression produces a chemosensitivity in glioma.

  11. Towards a new daily in-situ precipitation data set supporting parameterization of wet-deposition of CTBT relevant radionuclides

    Science.gov (United States)

    Becker, A.; Ceranna, L.; Ross, O.; Schneider, U.; Meyer-Christoffer, A.; Ziese, M.; Lehner, K.; Rudolf, B.

    2012-04-01

    As contribution to the World Climate Research Program (WCRP) and in support of the Global Climate Observing System (GCOS) of the World Meteorological Organization (WMO), the Deutscher Wetterdienst (DWD) operates the Global Precipitation Climatology Centre (GPCC). The GPCC re-analysis and near-real time monitoring products are recognized world-wide as the most reliable global data set on rain-gauge based (in-situ) precipitation measurements. The GPCC Monitoring Product (Schneider et al, 2011; Becker et al. 2012, Ziese et al, EGU2012-5442) is available two months after the fact based on the data gathered while listening to the GTS to fetch the SYNOP and CLIMAT messages. This product serves also the reference data to calibrate satellite based precipitation measurements yielding the Global Precipitation Climatology Project (GPCP) data set (Huffmann et al., 2009). The quickest GPCC product is the First Guess version of the GPCC Monitoring Product being available already 3-5 days after the month regarded. Both, the GPCC and the GPCP products bear the capability to serve as data base for the computational light-weight post processing of the wet deposition impact on the radionuclide (RN) monitoring capability of the CTBT network (Wotawa et al., 2009) on the regional and global scale, respectively. This is of major importance any time, a reliable quantitative assessment of the source-receptor sensitivity is needed, e.g. for the analysis of isotopic ratios. Actually the wet deposition recognition is a prerequisite if ratios of particulate and noble gas measurements come into play. This is so far a quite unexplored field of investigation, but would alleviate the clearance of several apparently CTBT relevant detections, encountered in the past, as bogus and provide an assessment for the so far overestimation of the RN detection capability of the CTBT network. Besides the climatological kind of wet deposition assessment for threshold monitoring purposes, there are also singular

  12. Regression of Stage IV Pancreatic Cancer to Curative Surgery and Introduction of a Novel Ex-Vivo Chemosensitivity Assay.

    Science.gov (United States)

    Rios Perez, Mayrim V; Dai, Bingbing; Koay, Eugene J; Wolff, Robert A; Fleming, Jason B

    2015-01-01

    Although data suggests little hope for survival when patients present with metastatic pancreatic cancer, recent advances in systemic therapy offer the possibility for dramatic tumor responses like those observed in other disease sites. Here, we present the case of a 50-year-old woman who presented with adenocarcinoma of the pancreas with two liver metastases and a CA 19-9 level of 1,659 U/mL. The patient received FOLFIRINOX (leucovorin, 5-fluorouracil, irinotecan, and oxaliplatin) with a dramatic reduction in CA 19-9 level to 23.9 U/mL, and complete regression of both liver metastases. The patient then received capecitabine with the maintenance of a normal CA19-9 over the next 12 months. With no evidence of distant disease, concurrent systemic and local therapy with capecitabine-based chemoradiation (CapeXRT) was performed followed by observation for eight months with normal CA 19-9 readings. A mild increase in CA 19-9 (143 U/mL) prompted a restaging demonstrating an active primary tumor but no distant disease. Therefore, a pancreaticoduodenectomy (PD or Whipple) was performed rendering this patient free of detectable cancer. Our team has developed an ex-vivo chemosensitivity assay in which the tumor tissue from an individual patient can be rapidly examined for sensitivity to available systemic therapy treatment strategies. We tested this patient's tumor for its sensitivity to gemcitabine (Gem) versus a combination of 5-fluorouracil, irinotecan, and oxaliplatin (FIRINOX). Remarkably, our assay confirmed a profound sensitivity of this patient's tumor to the agents she had received. PMID:26848412

  13. Paclitaxel stimulates chromosomal fusion and instability in cells with dysfunctional telomeres: Implication in multinucleation and chemosensitization

    Energy Technology Data Exchange (ETDEWEB)

    Park, Jeong-Eun [Division of Radiation Cancer Research, Korea Institute of Radiological and Medical Sciences, Seoul 139-706 (Korea, Republic of); Woo, Seon Rang [Division of Radiation Cancer Research, Korea Institute of Radiological and Medical Sciences, Seoul 139-706 (Korea, Republic of); Department of Biochemistry, College of Medicine, Korea University, Seoul 136-705 (Korea, Republic of); Kang, Chang-Mo [Laboratory of Cytogenetics and Tissue Regeneration, Korea Institute of Radiological and Medical Sciences, Seoul 139-706 (Korea, Republic of); Juhn, Kyoung-Mi; Ju, Yeun-Jin; Shin, Hyun-Jin; Joo, Hyun-Yoo; Park, Eun Ran; Park, In-chul; Hong, Sung Hee; Hwang, Sang-Gu [Division of Radiation Cancer Research, Korea Institute of Radiological and Medical Sciences, Seoul 139-706 (Korea, Republic of); Lee, Jung-Kee [Department of Life Science and Genetic Engineering, Paichai University, Daejeon 302-735 (Korea, Republic of); Kim, Hae Kwon [Department of Biotechnology, Seoul Woman' s University, Seoul 139-774 (Korea, Republic of); Cho, Myung-Haing [Laboratory of Toxicology, College of Veterinary Medicine, Seoul National University, Seoul 151-74-2 (Korea, Republic of); Park, Gil Hong [Department of Biochemistry, College of Medicine, Korea University, Seoul 136-705 (Korea, Republic of); Lee, Kee-Ho, E-mail: khlee@kirams.re.kr [Division of Radiation Cancer Research, Korea Institute of Radiological and Medical Sciences, Seoul 139-706 (Korea, Republic of)

    2011-01-14

    Research highlights: {yields} Paclitaxel serves as a stimulator of chromosomal fusion in cells in which telomeres are dysfunctional. {yields} Typical fusions involve p-arms, but paclitaxel-induced fusions occur between both q- and p-arms. {yields} Paclitaxel-stimulated fusions in cells in which telomeres are dysfunctional evoke prolonged G2/M cell cycle arrest and delay multinucleation. {yields} Upon telomere erosion, paclitaxel promotes chromosomal instability and subsequent apoptosis. {yields} Chromosomal fusion enhances paclitaxel chemosensitivity under telomere dysfunction. -- Abstract: The anticancer effect of paclitaxel is attributable principally to irreversible promotion of microtubule stabilization and is hampered upon development of chemoresistance by tumor cells. Telomere shortening, and eventual telomere erosion, evoke chromosomal instability, resulting in particular cellular responses. Using telomerase-deficient cells derived from mTREC-/-p53-/- mice, here we show that, upon telomere erosion, paclitaxel propagates chromosomal instability by stimulating chromosomal end-to-end fusions and delaying the development of multinucleation. The end-to-end fusions involve both the p- and q-arms in cells in which telomeres are dysfunctional. Paclitaxel-induced chromosomal fusions were accompanied by prolonged G2/M cell cycle arrest, delayed multinucleation, and apoptosis. Telomere dysfunctional cells with mutlinucleation eventually underwent apoptosis. Thus, as telomere erosion proceeds, paclitaxel stimulates chromosomal fusion and instability, and both apoptosis and chemosensitization eventually develop.

  14. Cerebral and muscle deoxygenation, hypoxic ventilatory chemosensitivity and cerebrovascular responsiveness during incremental exercise.

    Science.gov (United States)

    Peltonen, Juha E; Paterson, Donald H; Shoemaker, J Kevin; Delorey, Darren S; Dumanoir, Gregory R; Petrella, Robert J; Kowalchuk, John M

    2009-10-31

    To examine if cerebral (frontal cortex) and skeletal muscle (m. vastus lateralis) deoxygenation and cerebral blood flow velocity (V(mean)) in the middle cerebral artery differentiated between normoxic and hypoxic (end-tidal P(O)(2) 71 mmHg) conditions, and if they were associated with hypoxic ventilatory chemosensitivity and cerebrovascular responsiveness, 8 men performed incremental cycling trials (30W/min ramp) under normoxic (T1-N) and hypoxic (T1-H) conditions until volitional fatigue, or until arterial O2 saturation decreased below 80%. The tests were repeated (T2-N; T2-H) on another day with supplemental O2 (Sup-O2) at the end of exercise. The V(mean) response was similar in normoxia and hypoxia. In hypoxia compared to normoxia, cerebral deoxygenation ( upward arrow deoxyhemoglobin concentration (Delta[HHb]) and downward arrow tissue oxygenation index (TOI)) was greater at a given work rate. A strong hypoxic ventilatory chemosensitivity was associated with a rapid reduction of cerebral TOI (r=0.94, PMuscle deoxygenation was similar in normoxia and hypoxia suggesting greater muscle blood flow in hypoxia compared to normoxia and thus the existence of control features that match muscle perfusion and O2 delivery tightly with O2 demand during exercise. Sup-O2 reduced both cerebral and muscle deoxygenation, at least transiently. PMID:19729079

  15. A case of advanced intrahepatic cholangiocarcinoma successfully treated with chemosensitivity test-guided systemic chemotherapy

    Institute of Scientific and Technical Information of China (English)

    Kazumichi Abe; Takeru Wakatsuki; Fumiko Katsushima; Kyoko Monoe; Yukiko Kanno; Atsushi Takahashi; Junko Yokokawa; Hiromasa Ohira

    2009-01-01

    Intrahepatic cholangiocarcinoma (ICC) is a relatively rare and highly fatal neoplasm that arises from the biliary epithelium. Prognosis is generally poor and survival is limited to a few months. Here we present a case of advanced ICC successfully treated by chemosensitivity test-guided systemic chemotherapy combining S-1 and cisplatin (CDDP). A 65-year-old woman with a liver tumor was referred to our hospital on November 21, 2007. Abdominal ultrasonography and computed tomography (CT) showed low-density masses of 50 and 15 mm in diameter, respectively in segment Ⅷ of the liver and in the enlarged lymph node in the para-aorta. Ultrasonography-guided fine needle biopsy diagnosed the tumors as ICC. Since the patient was inoperable for lymph node metastasis, she underwent systemic chemotherapy with gemcitabine. Six months after initiation of chemotherapy, CT revealed ICC progression in the liver and pleural dissemination with pleural effusion. The patient was admitted to our hospital for anticancer drug sensitivity testing on June 9, 2008. Based on the sensitivity test results, we elected to administer systemic chemotherapy combining S-1 and CDDP. Two months into the second chemotherapy treatment, CT revealed a reduction of the tumors in the liver and lymph node and a decrease in pleural effusion.After eight cycles of the second chemotherapy, 17 mo after ICC diagnosis, she is alive and well with no sign of recurrence. We conclude that chemosensitivity testing may effectively determine the appropriate chemotherapy regimen for advanced ICC.

  16. In vitro chemosensitivity profile of oral squamous cell cancer and its correlation with clinical response to chemotherapy

    Directory of Open Access Journals (Sweden)

    Pathak K

    2007-01-01

    Full Text Available Context : Oral cancers represent a disparate group of tumors with diverse clinical behavior and chemosensitivity profile. Currently, it is difficult to predict whether a tumor will respond to chemotherapy and which drug(s will achieve the maximum clinical response. Aims : To study in vitro chemosensitivity profile of oral cancers and to correlate the in vitro chemosensitivity of oral cancer to clinical response to chemotherapy. Settings and Design : Prospective study in a tertiary cancer care center. Methods and Material : We prospectively studied the chemosensitivity profile of 57 untreated, advanced, unresectable oral cancers to cisplatin, methotrexate, 5-fluorouracil and their combinations by using histoculture drug response assay (HDRA and correlated them to the clinical response to chemotherapy. Statistical Analysis Used : Chi Square test. Results : Biopsy samples were successfully histocultured in 52/57 (91% cases. Of these 52 evaluable patients, 47 had primary gingivo-buccal cancers and five had tongue / floor of mouth cancers. Based on the assay, 27 (52% tumors were sensitive to cisplatin, 27 (52% to methotrexate, 24 (46% to 5-fluorouracil, 38 (73% to combination of cisplatin and methotrexate and 36 (69% to combination of cisplatin and 5-fluorouracil. Of these, 31 patients with good performance status received two cycles of chemotherapy using one or more of these test drugs. There was a significant correlation (p=0.03 between the in vitro chemosensitivity and the clinical response. Negative predictive value of the test was 80%, positive predictive value-69%, sensitivity-79% and specificity -71%. The overall accuracy of the assay was 74%. Conclusions : We found HDRA to be a fairly good predictor of chemo-response of oral cancer.

  17. Comparison of the ability of some radiosensitizers undergoing clinical trials to act as chemosensitizers

    International Nuclear Information System (INIS)

    The abilities of misonidazole, Ro 05-9963, Ro 03-8799 and Sr-2508 to enhance the action of the drugs cyclophosphamide (CY) and melphalan (L-PAM) have been compared in two mouse fibrosarcomas at acute and chronic sensitizer doses. SR-2508 was not effective with either CY or L-PAM in either tumor. Some enhancement of CY was obtained with Ro 05-9963 and Ro 03-8799; however, the degree of enhancement varied according to tumor and acute or chronic sensitizer dose. In all cases, the degree of enhancement was less than that obtained with an equivalent dose of misonidazole in both tumor systems. Of the four compounds tested, MISO would appear to have the most potential as a chemosensitizer

  18. 胰岛素增加肿瘤细胞化疗敏感性的研究%The effect of insulin on the chemosensitivity of cancer cells

    Institute of Scientific and Technical Information of China (English)

    孙龙昊; 何向辉; 朱理玮

    2010-01-01

    Objective To investigate the effect and mechanism of insulin and hypoglycemia on the chemosensitivity of cancer cells. Methods Human colon cancer cells SW480, mouse colon cancer cells CT-26 and mouse breast cancer cells 4T1 were cultured and treated with insulin and chemotheraputic drugs, 5-fluorouracil or methotrexate. MTT assay was used to measure the cytotoxity. Fluorescence microscopy and flow cytometry were used to determine the effects of insulin on the uptake of fluorescent methotrexate by cancer cells. Mouse breast cancer cells 4T1 were inoculated into syngeneic BALB/C mice. Insulin was administrated to the mice before giving methotrexate and the therapeutic effect was monitored. Results (1) Insulin enhanced the chemocytotoxity of chemotheraputic drugs on cancer cells by 4. 1% to 11.5%;(2) Insulin increased the uptake of fluorescent methotrexate by cancer cells in vitro by 141. 9% ;(3) Insulin and hypoglycemia enhanced the chemotherapeutic effect of methotrexate on mouse breast cancer models by 20. 1%. Conclusion Insulin and hypoglycemia increase absorption of chemotherapeutic agents by cancer cells and enhance the chemosensitivity of cancer cells.%目的 探讨胰岛素对肿瘤细胞化疗敏感性的影响及机制.方法 以胰岛素和甲氨蝶呤(MTX)或5-氟尿嘧啶(5-Fu)处理人结肠癌细胞SW480,小鼠结肠癌细胞CT-26及小鼠乳腺癌细胞4T1,噻唑蓝(MTT)法分析细胞活力,荧光显微镜和流式细胞术观察肿瘤细胞对荧光标记MTX的摄取,并利用小鼠荷瘤模型,观察胰岛素及低MTX糖对MTX化疗疗效的影响.结果 (1)胰岛素增加MTX和5-Fu的细胞毒作用4.1%-11.5%.(2)胰岛素增加肿瘤细胞对MTX摄取141.9%.(3)胰岛素及低血糖状态增强MTX抑瘤作用20.1%.结论 胰岛素及低血糖状态增加肿瘤细胞对化疗药物的吸收,提高肿瘤细胞对化疗药物的敏感性.

  19. The Effect of Primary Cancer Cell Culture Models on the Results of Drug Chemosensitivity Assays: The Application of Perfusion Microbioreactor System as Cell Culture Vessel

    OpenAIRE

    Chia-Hsun Hsieh; Yi-Dao Chen; Shiang-Fu Huang; Hung-Ming Wang; Min-Hsien Wu

    2015-01-01

    To precisely and faithfully perform cell-based drug chemosensitivity assays, a well-defined and biologically relevant culture condition is required. For the former, a perfusion microbioreactor system capable of providing a stable culture condition was adopted. For the latter, however, little is known about the impact of culture models on the physiology and chemosensitivity assay results of primary oral cavity cancer cells. To address the issues, experiments were performed. Results showed that...

  20. Chemosensitivity assay in mice prostate tumor: Preliminary report of flow cytometry, DNA fragmentation, ion ratiometric methods of anti-neoplastic drug monitoring

    OpenAIRE

    Kline Richard; Sharma Rakesh

    2004-01-01

    Abstract Flow cytometry, DNA fragmentation, ion ratiomateric analysis and NMR peaks characterized drug chemosensitivity of antineoplastic drugs. Hypotheses were: 1. The chemosensitive effect of different cancer cell lines is characteristic; 2. DNA fragmentation, ion ratiometric analysis suggest apoptosis status of tumor cells. Methods PC-3 cell lines were compared with DU-145, LNCaP cell lines in culture for the [Na]i and [Ca]i ion sensing dyes, cell death, NMR peaks and apoptosis staining fo...

  1. Clinical significance of chemosensitivity in chronic heart failure: influence on neurohormonal derangement, Cheyne-Stokes respiration and arrhythmias

    OpenAIRE

    Giannoni, Alberto; Emdin, Michele; Poletti, Roberta; Bramanti, Francesca; Prontera, Concetta; Piepoli, Massimo; Passino, Claudio

    2007-01-01

    Abstract Increased chemosensitivity has been observed in heart failure (HF). To investigate its pathophysiological and clinical relevance, we evaluated its impact on neurohormonal balance, breathing pattern, response to exercise, and arrhythmic profile. Sixty patients with chronic HF (age 66?1 years, left ventricular ejection fraction, EF, 31?1%, mean?SEM) underwent assessment of hypoxic-normocapnic (HVR) and hypercapnic-normoxic ventilatory response (HCVR), neurohormonal evaluat...

  2. Impact of Brachyury on epithelial-mesenchymal transitions and chemosensitivity in non-small cell lung cancer

    OpenAIRE

    Xu, Ke; Liu, Bin; Liu, Yongyu

    2015-01-01

    The objective of the current study was to investigate the impact of Brachyury on epithelial-mesenchymal transitions and chemosensitivity in non-small cell lung cancer (NSCLC). In 115 archived NSCLC tissue samples, the expression of Brachyury was observed to be significantly higher than that in adjacent normal lung tissues. In addition, the current study demonstrated that the expression of Brachyury is closely associated with TNM staging, lymph node metastasis and the prognosis of NSCLC, altho...

  3. STUDY ON RELATIONSHIP BETWEEN CHEMOSENSITIVITY OF BREAST CANCER AND EXPRESSION OF p73α AND p53

    Institute of Scientific and Technical Information of China (English)

    ZHOU Xin; SUN Zhi-jun

    2005-01-01

    Objective: To investigate the relationship between the expression of p73α and p53 versus the chemosensitivity in breast cancer cells. Methods: Twelve surgical samples of breast cancer diagnosed by pathology were used. The cancer sample cells were separately cultured in the incubator at 37℃, 5% CO2 in vitro. The relative inhibition rate of cancer cells by 4 kinds of anticancer drugs, which were EPI, MMC, 5-Fu and DDP, were assayed by MTT method. Immunocytochemistry was used to detect the expression of p73α and p53 in the cancer cells. Results: The positive expression of p73α was found in 5/12 (41.67%), and p53 positive expression rate was 50.0% (6/12). The relative inhibition rate of MMC, EPI, 5-Fu and DDP were significantly higher in the p73α positive cancer cells than in the p73α negative cancer cells. A positive correlation was found between expression of p73α and chemosensitivity for all the four anticancer drugs. Conclusion: The expression of p73α is related with the chemosensitivity of the breast cancer cells, and it may become one of the markers for judging the effect of chemotherapy in clinic.

  4. Overexpression of miR-100 inhibits cell proliferation, migration, and chemosensitivity in human glioblastoma through FGFR3

    Directory of Open Access Journals (Sweden)

    Luan YX

    2015-11-01

    Full Text Available Yongxin Luan,1 Shuyan Zhang,1 Ling Zuo,2 Lixiang Zhou1 1Department of Neurosurgery, First Bethune Hospital of Jilin University, 2Department of Ophthalmology, Second Bethune Hospital of Jilin University, Changchun, People’s Republic of China Background: Glioblastoma multiforme is one of the most deadly forms of brain cancer. We investigated the regulatory effects of microRNA-100 (miR-100 on cell proliferation, migration, and chemosensitivity in human glioblastoma. Methods: miR-100 expression was assessed by quantitative real-time polymerase chain reaction in both glioblastoma cells and human tumors. Lentiviruses of miR-100 mimics and inhibitors were transfected into U251 and T98G cells. The regulatory effects of either overexpressing or downregulating miR-100 on glioblastoma were evaluated by a viability assay, growth assay, migration assay, chemosensitivity assay, and an in vivo tumor transplantation assay. Expression of fibroblast growth factor receptor 3 (FGFR3, the bioinformatically predicted target of miR-100, was examined by Western blot in glioblastoma. FGFR3 was then ectopically overexpressed in U251 and T98G cells, and its effects on miR-100-mediated cancer regulation were evaluated by growth, migration, and chemosensitivity assays. Results: MiR-100 was markedly downregulated in both glioblastoma cell lines and human tumors. Overexpressing miR-100 through lentiviral transfection in U251 and T98G cells significantly inhibited cancer growth (both in vitro and in vivo and migration and increased chemosensitivity to cisplatin and 1, 3-bis (2-chloroethyl-l-nitrosourea, whereas downregulation of miR-100 had no effects on development of cancer. FGFR3 was directly regulated by miR-100 in glioblastoma. Ectopically overexpressing FGFR3 was able to ameliorate the anticancer effects of upregulation of miR-100 on glioblastoma growth, migration, and chemosensitivity. Conclusion: MiR-100 was generally downregulated in glioblastoma. Overexpressing mi

  5. Docosahexaenoic Acid Induces Oxidative DNA Damage and Apoptosis, and Enhances the Chemosensitivity of Cancer Cells

    Directory of Open Access Journals (Sweden)

    Eun Ah Song

    2016-08-01

    Full Text Available The human diet contains low amounts of ω-3 polyunsaturated fatty acids (PUFAs and high amounts of ω-6 PUFAs, which has been reported to contribute to the incidence of cancer. Epidemiological studies have shown that a high consumption of fish oil or ω-3 PUFAs reduced the risk of colon, pancreatic, and endometrial cancers. The ω-3 PUFA, docosahexaenoic acid (DHA, shows anticancer activity by inducing apoptosis of some human cancer cells without toxicity against normal cells. DHA induces oxidative stress and oxidative DNA adduct formation by depleting intracellular glutathione (GSH and decreasing the mitochondrial function of cancer cells. Oxidative DNA damage and DNA strand breaks activate DNA damage responses to repair the damaged DNA. However, excessive DNA damage beyond the capacity of the DNA repair processes may initiate apoptotic signaling pathways and cell cycle arrest in cancer cells. DHA shows a variable inhibitory effect on cancer cell growth depending on the cells’ molecular properties and degree of malignancy. It has been shown to affect DNA repair processes including DNA-dependent protein kinases and mismatch repair in cancer cells. Moreover, DHA enhanced the efficacy of anticancer drugs by increasing drug uptake and suppressing survival pathways in cancer cells. In this review, DHA-induced oxidative DNA damage, apoptotic signaling, and enhancement of chemosensitivity in cancer cells will be discussed based on recent studies.

  6. Chronic oxidative stress promotes H2AX protein degradation and enhances chemosensitivity in breast cancer patients.

    Science.gov (United States)

    Gruosso, Tina; Mieulet, Virginie; Cardon, Melissa; Bourachot, Brigitte; Kieffer, Yann; Devun, Flavien; Dubois, Thierry; Dutreix, Marie; Vincent-Salomon, Anne; Miller, Kyle Malcolm; Mechta-Grigoriou, Fatima

    2016-01-01

    Anti-cancer drugs often increase reactive oxygen species (ROS) and cause DNA damage. Here, we highlight a new cross talk between chronic oxidative stress and the histone variant H2AX, a key player in DNA repair. We observe that persistent accumulation of ROS, due to a deficient JunD-/Nrf2-antioxidant response, reduces H2AX protein levels. This effect is mediated by an enhanced interaction of H2AX with the E3 ubiquitin ligase RNF168, which is associated with H2AX poly-ubiquitination and promotes its degradation by the proteasome. ROS-mediated H2AX decrease plays a crucial role in chemosensitivity. Indeed, cycles of chemotherapy that sustainably increase ROS reduce H2AX protein levels in Triple-Negative breast cancer (TNBC) patients. H2AX decrease by such treatment is associated with an impaired NRF2-antioxidant response and is indicative of the therapeutic efficiency and survival of TNBC patients. Thus, our data describe a novel ROS-mediated regulation of H2AX turnover, which provides new insights into genetic instability and treatment efficacy in TNBC patients. PMID:27006338

  7. Hispidulin inhibits proliferation and enhances chemosensitivity of gallbladder cancer cells by targeting HIF-1α

    Energy Technology Data Exchange (ETDEWEB)

    Gao, Hui; Xie, Jing [Medical College, Qingdao University, Qingdao, Shandong 266071 (China); Peng, Jianjun, E-mail: jianjunpeng@126.com [College of Life Sciences, Chongqing Normal University, Chongqing 401331 (China); Han, Yantao, E-mail: hanyt19@126.com [Medical College, Qingdao University, Qingdao, Shandong 266071 (China); Jiang, Qixiao; Han, Mei; Wang, Chunbo [Medical College, Qingdao University, Qingdao, Shandong 266071 (China)

    2015-03-15

    Gallbladder cancer (GBC) is an aggressive malignancy of the bile duct, which is associated with a low (5-year) survival and poor prognosis. The transcription factor HIF-1α is implicated in the angiogenesis, cell survival, epithelial mesenchymal transition (EMT) and invasiveness of GBC. In this study, we have investigated the role of HIF-1α in the pathobilogy of GBC and effect of hispidulin on the molecular events controlled by this transcription factor. We observed that hispidulin caused induction of apoptosis, blockade of growth and cell cycle progression in GBC cells. Our results have demonstrated for the first time that hispidulin-exerted anti-tumor effect involved the suppression of HIF-1α signaling. Hispidulin was found to repress the expression of HIF-1α protein dose-dependently without affecting the HIF-1α mRNA expression. In addition, the inhibition of HIF-1α protein synthesis was revealed to be mediated through the activation of AMPK signaling. Hispidulin also sensitized the tumor cells to Gemcitabine and 5-Fluoroucil by down-regulating HIF-1α/P-gp signaling. Given the low cost and exceedingly safe profile, hispidulin appears to be a promising and novel chemosensitizer for GBC treatment. - Highlights: • Hispidulin inhibits proliferation of gallbladder cancer cells by targeting HIF-1α. • Hispidulin regulates HIF-1α via activating AMPK signaling. • Hispidulin sensitized the GBC cells to chemotherapeutics by down-regulating P-gp.

  8. Hispidulin inhibits proliferation and enhances chemosensitivity of gallbladder cancer cells by targeting HIF-1α

    International Nuclear Information System (INIS)

    Gallbladder cancer (GBC) is an aggressive malignancy of the bile duct, which is associated with a low (5-year) survival and poor prognosis. The transcription factor HIF-1α is implicated in the angiogenesis, cell survival, epithelial mesenchymal transition (EMT) and invasiveness of GBC. In this study, we have investigated the role of HIF-1α in the pathobilogy of GBC and effect of hispidulin on the molecular events controlled by this transcription factor. We observed that hispidulin caused induction of apoptosis, blockade of growth and cell cycle progression in GBC cells. Our results have demonstrated for the first time that hispidulin-exerted anti-tumor effect involved the suppression of HIF-1α signaling. Hispidulin was found to repress the expression of HIF-1α protein dose-dependently without affecting the HIF-1α mRNA expression. In addition, the inhibition of HIF-1α protein synthesis was revealed to be mediated through the activation of AMPK signaling. Hispidulin also sensitized the tumor cells to Gemcitabine and 5-Fluoroucil by down-regulating HIF-1α/P-gp signaling. Given the low cost and exceedingly safe profile, hispidulin appears to be a promising and novel chemosensitizer for GBC treatment. - Highlights: • Hispidulin inhibits proliferation of gallbladder cancer cells by targeting HIF-1α. • Hispidulin regulates HIF-1α via activating AMPK signaling. • Hispidulin sensitized the GBC cells to chemotherapeutics by down-regulating P-gp

  9. Effect of Recepteur d'Origine Nantais expression on chemosensitivity and tumor cell behavior in colorectal cancer.

    Science.gov (United States)

    Kim, Nuri; Cho, Sung-Bum; Park, Young-Lan; Park, Sun-Young; Myung, Eun; Kim, Seung-Hun; Yu, Hyung-Min; Son, Young-Ae; Myung, Dae-Seong; Lee, Wan-Sik; Joo, Young-Eun

    2016-06-01

    Recepteur d'Origine Nantais (RON) expression is known to induce oncogenic properties including tumor cell growth, survival, motility, angiogenesis and chemoresistance. In the present study, we evaluated whether RON affects chemosensitivity and oncogenic behavior of colorectal cancer cells and investigated its prognostic value in colorectal cancer. To evaluate the impact of RON on chemosensitivity and tumor cell behavior, we treated colorectal cancer cells with small interfering RNAs specific to RON. This was followed by flow cytometric analyses and migration, Matrigel invasion and endothelial tube formation assays. The expression of RON was investigated by immunohistochemistry in colorectal cancer tissues. TUNEL assay and immunohistochemical staining for CD34 and D2-40 were deployed to determine apoptosis, angiogenesis and lymphangiogenesis. RON knockdown enhanced 5-fluorouracil (FU)-induced apoptosis by upregulating the activities of caspases and expression of proapoptotic genes. Moreover, it enhanced 5-FU-induced cell cycle arrest by decreasing the expression of cyclins and cyclin‑dependent kinases and inducing that of p21. Furthermore, RON knockdown augmented the 5-FU-induced inhibition of invasion and migration of colorectal cancer cells. The β-catenin signaling cascade was blocked by RON knockdown upon 5-FU treatment. RON knockdown also decreased endothelial tube formation and expression of VEGF-A and HIF-1α and increased angiostatin expression. Furthermore, it inhibited lymphatic endothelial cell tube formation and the expression of VEGF-C and COX-2. RON expression was observed to be associated with age, tumor size, lymphovascular and perineural invasion, tumor stage, lymph node and distant metastasis, and poor survival rate. The mean microvessel density value of RON-positive tumors was significantly higher than that of RON-negative ones. These results indicate that RON is associated with tumor progression by inhibiting chemosensitivity and enhancing

  10. Decorin in human oral cancer: A promising predictive biomarker of S-1 neoadjuvant chemosensitivity

    Energy Technology Data Exchange (ETDEWEB)

    Kasamatsu, Atsushi, E-mail: kasamatsua@faculty.chiba-u.jp [Department of Oral Science, Graduate School of Medicine, Chiba University, Chiba 260-8670 (Japan); Department of Dentistry and Oral–Maxillofacial Surgery, Chiba University Hospital, Chiba 260-8670 (Japan); Uzawa, Katsuhiro, E-mail: uzawak@faculty.chiba-u.jp [Department of Oral Science, Graduate School of Medicine, Chiba University, Chiba 260-8670 (Japan); Department of Dentistry and Oral–Maxillofacial Surgery, Chiba University Hospital, Chiba 260-8670 (Japan); Minakawa, Yasuyuki; Ishige, Shunsaku; Kasama, Hiroki [Department of Oral Science, Graduate School of Medicine, Chiba University, Chiba 260-8670 (Japan); Endo-Sakamoto, Yosuke; Ogawara, Katsunori [Department of Dentistry and Oral–Maxillofacial Surgery, Chiba University Hospital, Chiba 260-8670 (Japan); Shiiba, Masashi; Takiguchi, Yuichi [Medical Oncology, Graduate School of Medicine, Chiba University, Chiba 260-8670 (Japan); Tanzawa, Hideki [Department of Oral Science, Graduate School of Medicine, Chiba University, Chiba 260-8670 (Japan); Department of Dentistry and Oral–Maxillofacial Surgery, Chiba University Hospital, Chiba 260-8670 (Japan)

    2015-01-30

    Highlights: • DCN is significantly up-regulated in chemoresistant cancer cell lines. • DCN is a key regulator for chemoresistant mechanisms in vitro and in vivo. • DCN predicts the clinical responses to S-1 NAC for patients with oral cancer. - Abstract: We reported previously that decorin (DCN) is significantly up-regulated in chemoresistant cancer cell lines. DCN is a small leucine-rich proteoglycan that exists and functions in stromal and epithelial cells. Accumulating evidence suggests that DCN affects the biology of several types of cancer by directly/indirectly targeting the signaling molecules involved in cell growth, survival, metastasis, and angiogenesis, however, the molecular mechanisms of DCN in chemoresistance and its clinical relevance are still unknown. Here we assumed that DCN silencing cells increase chemosusceptibility to S-1, consisted of tegafur, prodrug of 5-fluorouracil. We first established DCN knockdown transfectants derived from oral cancer cells for following experiments including chemosusceptibility assay to S-1. In addition to the in vitro data, DCN knockdown zenografting tumors in nude mice demonstrate decreasing cell proliferation and increasing apoptosis with dephosphorylation of AKT after S-1 chemotherapy. We also investigated whether DCN expression predicts the clinical responses of neoadjuvant chemotherapy (NAC) using S-1 (S-1 NAC) for oral cancer patients. Immunohistochemistry data in the preoperative biopsy samples was analyzed to determine the cut-off point for status of DCN expression by receiver operating curve analysis. Interestingly, low DCN expression was observed in five (83%) of six cases with complete responses to S-1 NAC, and in one (10%) case of 10 cases with stable/progressive disease, indicating that S-1 chemosensitivity is dramatically effective in oral cancer patients with low DCN expression compared with high DCN expression. Our findings suggest that DCN is a key regulator for chemoresistant mechanisms, and

  11. Decorin in human oral cancer: A promising predictive biomarker of S-1 neoadjuvant chemosensitivity

    International Nuclear Information System (INIS)

    Highlights: • DCN is significantly up-regulated in chemoresistant cancer cell lines. • DCN is a key regulator for chemoresistant mechanisms in vitro and in vivo. • DCN predicts the clinical responses to S-1 NAC for patients with oral cancer. - Abstract: We reported previously that decorin (DCN) is significantly up-regulated in chemoresistant cancer cell lines. DCN is a small leucine-rich proteoglycan that exists and functions in stromal and epithelial cells. Accumulating evidence suggests that DCN affects the biology of several types of cancer by directly/indirectly targeting the signaling molecules involved in cell growth, survival, metastasis, and angiogenesis, however, the molecular mechanisms of DCN in chemoresistance and its clinical relevance are still unknown. Here we assumed that DCN silencing cells increase chemosusceptibility to S-1, consisted of tegafur, prodrug of 5-fluorouracil. We first established DCN knockdown transfectants derived from oral cancer cells for following experiments including chemosusceptibility assay to S-1. In addition to the in vitro data, DCN knockdown zenografting tumors in nude mice demonstrate decreasing cell proliferation and increasing apoptosis with dephosphorylation of AKT after S-1 chemotherapy. We also investigated whether DCN expression predicts the clinical responses of neoadjuvant chemotherapy (NAC) using S-1 (S-1 NAC) for oral cancer patients. Immunohistochemistry data in the preoperative biopsy samples was analyzed to determine the cut-off point for status of DCN expression by receiver operating curve analysis. Interestingly, low DCN expression was observed in five (83%) of six cases with complete responses to S-1 NAC, and in one (10%) case of 10 cases with stable/progressive disease, indicating that S-1 chemosensitivity is dramatically effective in oral cancer patients with low DCN expression compared with high DCN expression. Our findings suggest that DCN is a key regulator for chemoresistant mechanisms, and

  12. Wild type p53 increased chemosensitivity of drug-resistant human hepatocellular carcinoma Be17402 / 5-FU cells

    Institute of Scientific and Technical Information of China (English)

    Yu-xiuLI; Zhi-binLIN; Huan-ranTAN

    2004-01-01

    AIM: To study the effect of wild type (wt) p53 gene transfection on drug resistant human hepatocellular carcinoma(HCC) cells induced by 5-Fluorouracil (5-FU). METHODS: The cytotoxicity of anticancer drugs on Be17402 and Be17402/5-FU cells was assessed using SRB assay, p53 expression was detected at its mRNA level by RT-PCR assay and at its protein level Western blot or immunocytochemistry assay in Be17402/5-FU cells transfected with either control vector or wt p53. AnnexinV-FITC/PI double labeled assay was performed to detect apoptosis. The chemosensitivity of Be17402/5-FU cells transfected with wt p53 was assessed using SRB assay. RESULTS: Be17402/5-FU cells exhibited cross-resistance to vincristine, doxorubicin, paclitaxel, and so on. wt p53 gene transfection upregulated the expression of p53 in Be17402/5-FU cells, wt p53 was able to greatly inhibit cell proliferation and significantly induce apoptosis in Be17402/5-FU cells. Moreover, wt p53 gene transfection increased the chemosensitivity of Be17402/5-FU cells to some anticancer drugs. CONCLUSION: These results indicated that the wt p53 gene transfection not only induced suppression of cell growth, but also increased the sensitivity of Be17402/5-FU cells to 5-FU, vincristine, and doxorubicin.

  13. Restoration of IGFBP-rP1 increases radiosensitivity and chemosensitivity in hormone-refractory human prostate cancer

    International Nuclear Information System (INIS)

    We previously reported the tumor-suppressive activity of insulin-like growth factor binding protein-related protein 1 (IGFBP-rP1) through induction of apoptosis in human prostate cancer cells. The aim of this study was to investigate the effects of IGFBP-rP1 for radiosensitivity and chemosensitivity in hormone-refractory human prostate PC-3 cancer cells. Five assays were performed using PC-3 cells transfected with IGFBP-rP1 (PC-3rP1) and control cells transfected with an empty vector (PC-3N): PC-3rP1 and PC-3N were compared by clonogenic survival assay, cell cycle analysis and apoptotic assay for radiosensitivity. The number of colonies of PC-3rP1 cells significantly decreased after 4 and 8 Gy of irradiation, compared with those of PC-3N in the clonogenic survival assay. After 16 hr irradiation at 8 Gy, the percentage of apoptotic cells significantly increased in PC-3rP1 compared with PC-3N. Growth of PC-3rP1 was significantly lower than that of PC-3N after docetaxel treatment both in vitro and in vivo. These results indicate that restoration of IGFBP-rP1 to PC-3 cells increases both their radiosensitivity and chemosensitivity. (author)

  14. Chemosensitizing effect of podophyllotoxin acetate on topoisomerase inhibitors leads to synergistic enhancement of lung cancer cell apoptosis

    Science.gov (United States)

    HONG, WAN GI; CHO, JEONG HYUN; HWANG, SANG-GU; LEE, EUNAH; LEE, JAESEOK; KIM, JONG-IL; UM, HONG-DUCK; PARK, JONG KUK

    2016-01-01

    Podophyllotoxin acetate (PA) acts as a radiosensitizer against non-small cell lung cancer (NSCLC) in vitro and in vivo. In this study, we examined its potential role as a chemosensitizer in conjunction with the topoisomerase inhibitors etoposide (Eto) and camptothecin (Cpt). The effects of combinations of PA and Eto/Cpt were examined with CompuSyn software in two NSCLC cell lines, A549 and NCI-H1299. Combination index (CI) values indicated synergistic effects of PA and the topoisomerase inhibitors. The intracellular mechanism underlying synergism was further determined using propidium iodide uptake, immunoblotting and electrophoretic mobility shift assay (EMSA). Combination of PA with Eto/Cpt promoted disruption of the dynamics of actin filaments, leading to subsequent enhancement of apoptotic cell death via induction of caspase-3, -8, and -9, accompanied by increased phosphorylation of p38. Conversely, suppression of p38 phosphorylation blocked the apoptotic effect of the drug combinations. Notably, CREB-1, a transcription factor, was constitutively activated in both cell types, and synergistically inhibited upon combination treatment. Our results collectively indicate that PA functions as a chemosensitizer by enhancing apoptosis through activation of the p38/caspase axis and suppression of CREB-1. PMID:27035096

  15. Organ-Tumor-on-a-Chip for Chemosensitivity Assay: A Critical Review

    Directory of Open Access Journals (Sweden)

    Navid Kashaninejad

    2016-07-01

    Full Text Available With a mortality rate over 580,000 per year, cancer is still one of the leading causes of death worldwide. However, the emerging field of microfluidics can potentially shed light on this puzzling disease. Unique characteristics of microfluidic chips (also known as micro-total analysis system make them excellent candidates for biological applications. The ex vivo approach of tumor-on-a-chip is becoming an indispensable part of personalized medicine and can replace in vivo animal testing as well as conventional in vitro methods. In tumor-on-a-chip, the complex three-dimensional (3D nature of malignant tumor is co-cultured on a microfluidic chip and high throughput screening tools to evaluate the efficacy of anticancer drugs are integrated on the same chip. In this article, we critically review the cutting edge advances in this field and mainly categorize each tumor-on-a-chip work based on its primary organ. Specifically, design, fabrication and characterization of tumor microenvironment; cell culture technique; transferring mechanism of cultured cells into the microchip; concentration gradient generators for drug delivery; in vitro screening assays of drug efficacy; and pros and cons of each microfluidic platform used in the recent literature will be discussed separately for the tumor of following organs: (1 Lung; (2 Bone marrow; (3 Brain; (4 Breast; (5 Urinary system (kidney, bladder and prostate; (6 Intestine; and (7 Liver. By comparing these microchips, we intend to demonstrate the unique design considerations of each tumor-on-a-chip based on primary organ, e.g., how microfluidic platform of lung-tumor-on-a-chip may differ from liver-tumor-on-a-chip. In addition, the importance of heart–liver–intestine co-culture with microvasculature in tumor-on-a-chip devices for in vitro chemosensitivity assay will be discussed. Such system would be able to completely evaluate the absorption, distribution, metabolism, excretion and toxicity (ADMET of

  16. Improving the understanding of the global distribution of the Radioxenon Background caused by known civil emissions and its consequences for CTBT verification

    Science.gov (United States)

    Wotawa, G.; Becker, A.; Kalinowski, M.; Saey, P.; Tuma, M.; Zaehringer, M.

    2009-04-01

    Monitoring of radioactive noble gases, in particular xenon radioisotopes, is a crucial activity for the verification of the Comprehensive Nuclear-Test-Ban Treaty. In a previous study, it was found that the distribution and magnitude of the global background of the isotope xenon-133 measured at stations of the International Monitoring System is to a large extent consistent with the hypothesis that it results from the currently known civil sources, namely isotope production facilities and nuclear power plants. In the new study, more sophisticated methodologies for background simulation and comparison are applied. All available data on the temporal variations of emissions and production cycles from the background dominating facilities Chalk River in Canada and Fleurus in Belgium are taken into account. Particularly data from the year 2008 provide a unique opportunity to allocate fractions of site specific background to individual sources as there have been several longer downtime periods of major xenon sources. Furthermore, an attempt to better account for batch releases from reactors in a statistical way based on the emission studies available is presented. The subsequent data analysis is enhanced by including not only daily and annual observation values, but also weekly and monthly median values from each station. Consequently, a more complete and consistent picture on the global xenon-133 emissions is presented, and improved conclusions regarding the verification of the CTBT based on noble gas monitoring are drawn. Finally, computations are also expanded to the other three relevant radioxenon isotopes.

  17. Proceedings of the 22nd Annual DoD/DOE Seismic Research Symposium: Planning for Verification of and Compliance with the Comprehensive Nuclear-Test-Ban Treaty (CTBT)

    Energy Technology Data Exchange (ETDEWEB)

    Nichols, James W., LTC [Editor

    2000-09-15

    These proceedings contain papers prepared for the 22nd Annual DoD/DOE Seismic Research Symposium: Planning for Verification of and Compliance with the Comprehensive Nuclear-Test-Ban Treaty (CTBT), held 13-15 September 2000 in New Orleans, Louisiana. These papers represent the combined research related to ground-based nuclear explosion monitoring funded by the National Nuclear Security Administration (NNSA), Defense Threat Reduction Agency (DTRA), Air Force Technical Applications Center (AFTAC), Department of Defense (DoD), US Army Space and Missile Defense Command, Defense Special Weapons Agency (DSWA), and other invited sponsors. The scientific objectives of the research are to improve the United States capability to detect, locate, and identify nuclear explosions. The purpose of the meeting is to provide the sponsoring agencies, as well as potential users, an opportunity to review research accomplished during the preceding year and to discuss areas of investigation for the coming year. For the researchers, it provides a forum for the exchange of scientific information toward achieving program goals, and an opportunity to discuss results and future plans. Paper topics include: seismic regionalization and calibration; detection and location of sources; wave propagation from source to receiver; the nature of seismic sources, including mining practices; hydroacoustic, infrasound, and radionuclide methods; on-site inspection; and data processing.

  18. Predictive value of MTT assay as an in vitro chemosensitivity testing for gastric cancer: One institution's experience

    Institute of Scientific and Technical Information of China (English)

    Bin Wu; Jin-Shui Zhu; Yi Zhang; Wei-Ming Shen; Qiang Zhang

    2008-01-01

    AIM: To investigate the predictive clinical value of in vitro 3-(4,5-dimethylthiazolyl-2)-2, 5-diphenyltetrazolium bromide (MTT) assay for directing chemosensitivity in patients with gastric cancer.METHODS: Results of a total of 353 consecutive patients with gastric cancer treated with MTT-directed chemotherapy or physician's empirical chemotherapy from July 1997 to April 2003 were reviewed and analyzed retrospectively.RESULTS: The overall 5-year survival rate of MTTsensitive group (MSG) and control group (CG) was 47.5% and 45.1%, respectively. The results of subgroup analysis with Cox proportional-hazards model were favorable for the MSG-sensitive group. However, no statistically significant difference in survival rate was observed between the two groups.CONCLUSION: Individualized chemotherapy based on in vitro MTT assay is beneficial, but needs to be confirmed by further randomized controlled trials.

  19. Suppression of bcl-2 Gene by RNA Interference Increases Chemosensitivity to Cisplatin in Nasopharyngeal Carcinoma Cell Line CNE1

    Institute of Scientific and Technical Information of China (English)

    Zhi-Hua YIN; Cai-Ping REN; Feng LI; Xu-Yu YANG; Hui LI; Ming ZHAO; Kai-Tai YAO

    2004-01-01

    To explore the effect of suppressing BCL-2 expression using RNA interference (RNAi) technique in nasopharyngeal carcinoma cell line CNE1. CNE1 cell lines stably expressing shRNAs targeted bcl-2 and GL3 gene were established and gene expression inhibition was assessed by Western blotting analysis. The effect of suppressing bcl-2 by RNAi on cell growth was studied, the apoptosis induction and the sensitization of CNE 1 cells to cisplatin were quantified by MTT assay and flow cytometry. The results showed that: stable transfection of CNE 1 cells with vectors expressing shRNAs against bcl-2 decreased the expression of BCL-2 protein; suppression of BCL-2 expression did not affect cell proliferation but could increase the chemosensitivity to cisplatin in CNE1 cells. This will help physicians to make some clinical trials of gene therapy on nasopharyngeal carcinoma by RNAi.

  20. Agent engineering

    CERN Document Server

    Liu, Jiming; Zhong, Ning; Wang, Patrick S P

    2001-01-01

    Agent engineering concerns the development of autonomous computational or physical entities capable of perceiving, reasoning, adapting, learning, cooperating and delegating in a dynamic environment. It is one of the most promising areas of research and development in information technology, computer science and engineering. This book addresses some of the key issues in agent engineering: What is meant by "autonomous agents"? How can we build agents with autonomy? What are the desirable capabilities of agents with respect to surviving (they will not die) and living (they will furthermore enjoy

  1. Modulation of P-Glycoprotein Mediated Multidrug Resistance (Mdr in Cancer Using Chemosensitizers.

    Directory of Open Access Journals (Sweden)

    Velingkar V.S

    2010-03-01

    Full Text Available Multidrug resistance (MDR is one of the main obstacles in the chemotherapy of cancer. MDR is associated with the over expression of P-glycoprotein (P-gp, resulting in increased efflux of chemotherapy from cancer cells. Inhibiting P-gp as a method to reverse MDR in cancer patients has been studied extensively, but the results have generally been disappointing. First-generation agents were limited by unacceptable toxicity, whereas second-generation agents had bettertolerability but were confounded by unpredictable pharmacokinetic interactions and interactions with other transporter proteins. Third-generation inhibitors have high potency and specificity for P-gp. Furthermore, pharmacokinetic studies to date have shown no appreciable impact on drug metabolism and no clinically significant drug interactions with common chemotherapy agents. Third-generation P-gp inhibitors have shown promise in clinical trials. The continued development of these agents may establish the true therapeutic potential of P-gp-mediated MDR reversal.

  2. RASSF1A expression inhibits cell growth and enhances cell chemosensitivity to mitomycin in BEL-7402 hepatocellular carcinoma cells

    Institute of Scientific and Technical Information of China (English)

    GUAN Hong-geng; XUE Wan-jiang; QIAN Hai-xin; ZHOU Xiao-jun; QIN Lei; LAN Jing

    2009-01-01

    Background The antitumor role of Ras association domain family 1A (RASSFIA) gene and its potential molecular mechanisms are not well understood. The objective of this study was to observe the antitumor ability of RASSFIA in hepatoceliular carcinoma, and study the mechanisms of cell apoptosis induced by RASSFIA.Methods After stably transfecting a RASSF1A (wild-type or mutant) expression vector into the BEL-7402 hepatocellular carcinoma cell line, RT-PCR and Westem blotting was used to detect the RASSF1A expression levels in recombinant cells. The effects of wild-type RASSF1A on cell growth were observed in vitro by analyzing cell proliferation rate, cell colony formation, and in vivo by analyzing tumorigenesis in nude mice. In addition, the effect of RASSF1A gene expression on the chemosensitivity of human hepatocellular carcinoma cells to antitumor drugs was examined by inhibition of cell proliferation and the percentage of apoptotic cells.Results Wild-type RASSF1A, not the mutant, suppressed cell growth in vitro and in vivo. Re-expression of wild-type RASSF1A could enhance the inhibition of cell proliferation and the percentage of apoptotic cells following cell treatment with mitomycin, but had no significant effect when combined with adriamycin, etoposide, 5-fluorouracil and cisplatJn treatment.Conclusion Wild-type RASSF1A inhibits cell growth and enhances cell chemosensitivity to mitomycin in hepatocellular carcinoma, suggesting that RASSF1A may serve as a new target for gene therapy in hepatocellular carcinoma patients.

  3. Chemosensitizing effects of carbon-based nanomaterials in cancer cells: enhanced apoptosis and inhibition of proliferation as underlying mechanisms

    Science.gov (United States)

    Erdmann, Kati; Ringel, Jessica; Hampel, Silke; Rieger, Christiane; Huebner, Doreen; Wirth, Manfred P.; Fuessel, Susanne

    2014-10-01

    Recent studies have shown that carbon nanomaterials such as carbon nanofibres (CNFs) and multi-walled carbon nanotubes (CNTs) can exert antitumor activities themselves and sensitize cancer cells to conventional chemotherapeutics such as carboplatin and cisplatin. In the present study, the chemosensitizing effect of CNFs and CNTs on cancer cells of urological origin was investigated regarding the underlying mechanisms. Prostate cancer (DU-145, PC-3) and bladder cancer (EJ28) cells were treated with carbon nanomaterials (CNFs, CNTs) and chemotherapeutics (carboplatin, cisplatin) alone as well as in combination for 24 h. Forty-eight (EJ28) or 72 h (DU-145, PC-3) after the end of treatment the effects on cellular proliferation, clonogenic survival, cell death rate and cell cycle distribution were evaluated. Depending on the cell line, simultaneous administration of chemotherapeutics and carbon nanomaterials produced an additional inhibition of cellular proliferation and clonogenic survival of up to 77% and 98%, respectively, compared to the inhibitory effects of the chemotherapeutics alone. These strongly enhanced antiproliferative effects were accompanied by an elevated cell death rate, which was predominantly mediated via apoptosis and not by necrosis. The antitumor effects of combinations with CNTs were less pronounced than those with CNFs. The enhanced effects of the combinatory treatments on cellular function were mostly of additive to partly synergistic nature. Furthermore, cell cycle analysis demonstrated an arrest at the G2/M phase mediated by a monotreatment with chemotherapeutics. Following combinatory treatments, mostly less than or nearly additive increases of cell fractions in the G2/M phase could be observed. In conclusion, the pronounced chemosensitizing effects of CNFs and CNTs were mediated by an enhanced apoptosis and inhibition of proliferation. The combination of carbon-based nanomaterials and conventional chemotherapeutics represents a novel

  4. ER maleate is a novel anticancer agent in oral cancer: implications for cancer therapy

    Science.gov (United States)

    Fu, Guodong; Somasundaram, Raj Thani; Jessa, Fatima; Srivastava, Gunjan; MacMillan, Christina; Witterick, Ian; Walfish, Paul G.; Ralhan, Ranju

    2016-01-01

    ER maleate [10-(3-Aminopropyl)-3, 4-dimethyl-9(10H)-acridinone maleate] identified in a kinome screen was investigated as a novel anticancer agent for oral squamous cell carcinoma (OSCC). Our aim was to demonstrate its anticancer effects, identify putative molecular targets and determine their clinical relevance and investigate its chemosensitization potential for platinum drugs to aid in OSCC management. Biologic effects of ER maleate were determined using oral cancer cell lines in vitro and oral tumor xenografts in vivo. mRNA profiling, real time PCR and western blot revealed ER maleate modulated the expression of polo-like kinase 1 (PLK1) and spleen tyrosine kinase (Syk). Their clinical significance was determined in oral SCC patients by immunohistochemistry and correlated with prognosis by Kaplan-Meier survival and multivariate Cox regression analyses. ER maleate induced cell apoptosis, inhibited proliferation, colony formation, migration and invasion in oral cancer cells. Imagestream analysis revealed cell cycle arrest in G2/M phase and increased polyploidy, unravelling deregulation of cell division and cell death. Mechanistically, ER maleate decreased expression of PLK1 and Syk, induced cleavage of PARP, caspase9 and caspase3, and increased chemosensitivity to carboplatin; significantly suppressed tumor growth and increased antitumor activity of carboplatin in tumor xenografts. ER maleate treated tumor xenografts showed reduced PLK1 and Syk expression. Clinical investigations revealed overexpression of PLK1 and Syk in oral SCC patients that correlated with disease prognosis. Our in vitro and in vivo findings provide a strong rationale for pre-clinical efficacy of ER maleate as a novel anticancer agent and chemosensitizer of platinum drugs for OSCC. PMID:26934445

  5. Atmospheric transport modelling for the CTBT radionuclide network in routine operation and after the Fukushima releases; Atmosphaerische Transportmodellierung fuer das Radionuklidmessnetz zur Ueberwachung des Kernwaffenteststoppvertrages im Regelbetrieb und nach den Freisetzungen in Fukushima

    Energy Technology Data Exchange (ETDEWEB)

    Ross, J.O.; Ceranna, L.; Boennemann, C. [Bundesanstalt fuer Geowissenschaften und Rohstoffe (BGR), Hannover (Germany). B4.3; Schlosser, C. [Bundesamt fuer Strahlenschutz (BfS), Freiburg (Germany). SW2.5

    2014-01-20

    The Comprehensive Nuclear-Test-Ban Treaty (CTBT) bans all types of nuclear explosions. For verification of compliance with Treaty the International Monitoring System (IMS) is being built up by the Provisional Technical Secretariat (PTS) of the CTBT-Organisation in Vienna. The IMS observes waveform signals (seismic, infrasound, hydroacoustic) of explosions and traces of radionuclides in the atmosphere to proof the nuclear character of an event. The International Data Centre (IDC) provides analysis products for the IMS data such as various event bulletins, radionuclide reports, and atmospheric transport modeling (ATM) results confining the possible source region of detected radionuclides. The judgment on the character of a suspicious event remains with the member states. The German National Data Centre for verification of CTBT is hosted by the Federal Institute for Geosciences and Natural Resources (BGR) in Hannover. The BGR operates four IMS stations (IS26, IS27, PS19, and AS35) and cooperates closely with the Federal Office for Radiation Protection (BfS) who operates the radionuclide station RN33 at mount Schauinsland and supports the NDC with radionuclide expertise. In response to the Fukushima accident caused by the large magnitude 9.0 Tohuku Earthquake and Tsunami the HSYSPLIT model driven by 0.5 degree NCEP data was used at the German NDC to simulate the primary transport pathways of potentially emitted radioisotopes. The analysis focuses on arrival times and dilution ratios at the radionuclide stations of the IMS. The arrival times were predicted correctly at most stations for ten days after the accident. Traces of the Fukushima emissions were detected at all IMS radionuclide stations on the Northern Hemisphere end of March. In April also some stations on the Southern Hemisphere detected some traces which passed the ITCZ. In respect to the CTBT context the influence of the Tohoku earthquake and the Fukushima emissions on the network capability to detect a

  6. MicroRNA-mediated Silencing of RhoC Inhibits Tumor Invasion and Increases Chemosensitivity to Paclitaxel in SKOV3 Cells in vitro

    Institute of Scientific and Technical Information of China (English)

    PAN Ying; DU Zhen-wu; LENG Wei-chun; ZHOU Jia-wen; WANG Ying-jian; SHENG Min-jia; WANG Jun-rong; ZHANG Gui-zhen

    2011-01-01

    RhoC is a member of the Ras-homologous family of genes which are implicated in tumorigenesis and tumor progression. Up-regulation of RhoC is associated with tumor progression in ovarian carcinoma and RhoC is significantly correlated with the invasive capability of ovarian cancer cell lines in vitro. We developed a system that blocks RhoC in the human ovarian cancer SKOV3 cells using specific MicroRNA(miRNA) interference. By transfecting SKOV3 cells with the plasmid vector to express specific MiRNA that targets human RhoC, we were able to establish a stable clone in which RhoC expression was significantly downregnlated. This resulted in the decreased invasive potential of SKOV3 cells as well as increased chemosensitivity to paclitaxel. RhoC involves in invasion and chemosensitivity of SKOV3, indicating that RhoC may be a promising therapeutic target for ovarian cancer.

  7. Effects of hypoxia on expression of a panel of stem cell and chemosensitivity markers in glioblastoma cell line-derived spheroids

    DEFF Research Database (Denmark)

    Kolenda, Jesper; Jensen, Stine Skov; Aaberg-Jessen, Charlotte;

    entire immunohistochemical panel included hypoxia (HIF-1α, HIF-2α), proliferation (Ki-67) and stem cell (CD133, nestin, podoplanin, Bmi-1, Sox-2) markers as well as markers related to chemosensitivity (MGMT, MDR-1, TIMP-1, Lamp-1). Since spheroids derived in hypoxia were smaller than in normoxia, a set...... differences were found for podoplanin, nestin and TIMP-1 as well as for Ki-67. Hif-2α, Sox-2, MGMT and MDR-1 were not detectable in normoxic and hypoxic U87 spheroids. In conclusion, the expression of tumor stem cell and chemosensitivity markers seems to depend on the oxygen tension suggesting that future...... oxygen tensions below 1-5% O2 has been attributed to play a crucial role in tumorigenesis and therapeutic resistance in glioblastoma. This is in contrast to most in vitro experiments in this field being performed in atmospheric air with 21% O2. In this study the influence of hypoxia on the expression of...

  8. Chemosensitivity Predicted by BluePrint 80-Gene Functional Subtype and MammaPrint in the Prospective Neoadjuvant Breast Registry Symphony Trial (NBRST)

    OpenAIRE

    Whitworth, Pat; Stork-Sloots, Lisette; de Snoo, Femke A.; Richards, Paul; Rotkis, Michael; Beatty, Jennifer; Mislowsky, Angela; Pellicane, James V.; Nguyen, Bichlien; Lee, Laura; Nash, Charles; Gittleman, Mark; Akbari, Stephanie; Beitsch, Peter D.

    2014-01-01

    Purpose The purpose of the NBRST study is to compare a multigene classifier to conventional immunohistochemistry (IHC)/fluorescence in situ hybridization (FISH) subtyping to predict chemosensitivity as defined by pathological complete response (pCR) or endocrine sensitivity as defined by partial response. Methods The study includes women with histologically proven breast cancer, who will receive neoadjuvant chemotherapy (NCT) or neoadjuvant endocrine therapy. BluePrint in combination with Mam...

  9. Application of ATP-bioluminescence assay for screening chemotherapeutic agents of ovarian cancer chemotherapy

    International Nuclear Information System (INIS)

    To evaluate the feasibility of using ATP-bioluminescence assay for tumor chemosensitivity testing in vitro, authors selected the A2780 cell line as a model and established the suitable assay condition. Screening chemotherapeutic agents of ovarian cancer in vitro were preliminarily researched. Using this assay, dose-response curve was detected in cell line treated with these agents. The result showed that the coefficients of variation for assay ranged from 0.2% to 8.2%, which means high reproducibility. It can measured ATP content of as few as forty cells. The thermal stability of the luciferin-luciferase system was high enough used in industry. The predictable accuracy rate is about 90.6%. This study demonstrated ATP-bioluminescence assay is a reliable, reproducible and sensitive method. It can provide a technical base for screening sensitive chemotherapeutic agents in clinic

  10. Antibiotic Agents

    Science.gov (United States)

    ... either as public health or as non-public health antimicrobial agents. What is the difference between bacteriostats, sanitizers, disinfectants ... bacteria, however, there is considerable controversy surrounding their health benefits. The ... producing agents (Table of Antibacterials) have been used for many ...

  11. RNAi-mediated silencing of CD147 inhibits tumor cell proliferation, invasion and increases chemosensitivity to cisplatin in SGC7901 cells in vitro

    Directory of Open Access Journals (Sweden)

    Zhu Chan

    2010-06-01

    Full Text Available Abstract Background CD147 is a widely distributed cell surface glycoprotein that belongs to the Ig superfamily. CD147 has been implicated in numerous physiological and pathological activities. Enriched on the surface of many tumor cells, CD147 promotes tumor growth, invasion, metastasis and angiogenesis and confers resistance to some chemotherapeutic drugs. In this study, we investigated the possible role of CD147 in the progression of gastric cancer. Methods Short hairpin RNA (shRNA expressing vectors targeting CD147 were constructed and transfected into human gastric cancer cells SGC7901 and CD147 expression was monitored by quantitative realtime RT-PCR and Western blot. Cell proliferation, the activities of MMP-2 and MMP-9, the invasive potential and chemosensitivity to cisplatin of SGC7901 cells were determined by MTT, gelatin zymography, Transwell invasion assay and MTT, respectively. Results Down-regulation of CD147 by RNAi approach led to decreased cell proliferation, MMP-2 and MMP-9 activities and invasive potential of SGC7901 cells as well as increased chemosensitivity to cisplatin. Conclusion CD147 involves in proliferation, invasion and chemosensitivity of human gastric cancer cell line SGC7901, indicating that CD147 may be a promising therapeutic target for gastric cancer.

  12. Co-expression of ING4 and P53 enhances hypopharyngeal cancer chemosensitivity to cisplatin in vivo.

    Science.gov (United States)

    Ren, Xin; Liu, Hao; Zhang, Mingjie; Wang, Mengjun; Ma, Shiyin

    2016-09-01

    Hypopharyngeal cancer is a distinct type of malignant head and neck tumor, which exhibits low sensitivity to anti-cancer drugs. The importance of developing methods for reducing chemotherapy resistance, and improving and enhancing prognosis has previously been emphasized and is considered a challenge for effective clinical treatment of hypopharyngeal cancer. The current study investigated the effects of co‑expression of inhibitor of growth protein 4 (ING4) and P53, a tumor suppressor gene, on chemosensitivity to cisplatin in human hypopharyngeal cancer xenografts in vivo, and the potential molecular mechanisms involved. A tumor model was established by injecting athymic nude mice with FADU human hypopharyngeal cancer cells. Five days after intratumoral and peritumoral injections of an empty adenoviral vector (Ad), Ad‑ING4‑P53, cisplatin, or a combination of Ad‑ING4‑P53 and cisplatin (Ad‑ING4‑P53 + cisplatin) every other day for 5 days, the mice were euthanized and their tumors, livers, and kidneys were removed. The tumor weights were used to calculate the inhibition rate, and the expression levels of ING4 and P53 were detected by reverse transcription‑polymerase chain reaction. Additionally, apoptotic cells were detected using terminal deoxynucleotidyl transferase dUTP nick end labeling, and immunohistochemistry determined the levels ING4, P53, B‑cell lymphoma‑2 (Bcl‑2) and Bcl‑2 associated X protein (Bax) protein expression. The results demonstrated increased expression of ING4 and P53 in the Ad‑ING4‑P53 groups compared with PBS and Ad groups, indicating successful introduction of the genes into the tumor cells. Notably, the Ad‑ING4‑P53 + cisplatin group exhibited a higher inhibition rate compared with the four other groups. The results of immunohistochemistry analysis demonstrated that Bax expression was increased and Bcl‑2 was decreased in the Ad‑ING4‑P53 + cisplatin group. This suggested that the enhanced

  13. Assessment of central chemosensitivity and cardiac sympathetic nerve activity using I-123 MIBG imaging in central sleep apnea syndrome in patients with dilated cardiomyopathy

    International Nuclear Information System (INIS)

    Iodine-123 m-iodobenzylguanidine (MIBG) imaging has been used to study cardiac sympathetic function in various cardiac diseases. Central sleep apnea syndrome (CSAS) occurs frequently in patients with chronic heart failure (CHF) and is reported to be associated with a poor prognosis. One of the mechanisms of its poor prognosis may be related to impaired cardiac sympathetic activity. However, the relationship between chemosensitivity to carbon dioxide, which is reported to correlate with the severity of CSAS, and cardiac sympathetic activity has not been investigated. Therefore, this study was undertaken to assess cardiac sympathetic function and chemosensitivity to carbon dioxide in CHF patients. The oxygen desaturation index (ODI) was evaluated in 21 patients with dilated cardiomyopathy (male/female: 19/2, left ventricular ejection fraction (LVEF)5 times/h underwent polysomnography. Patients with an apnea hypopnea index >15/h but without evidence of obstructive apnea were defined as having CSAS. Early (15 min) and delayed (4 hr) planar MIBG images were obtained from these patients. The mean counts in the whole heart and the mediastinum were obtained. The heart-to-mediastinum count ratio of the delayed image (H/M) and the corrected myocardial washout rate (WR) were also calculated. The central chemoreflex was assessed with the rebreathing method using a hypercapnic gas mixture (7% CO2 and 93% O2). Ten of the 21 patients had CSAS. The H/M ratio was similar in patients both with and without CSAS (1.57±0.18 vs. 1.59±0.14, p=0.82). However, the WR was higher in patients with CSAS than in patients without CSAS (40±8% vs. 30±12%, p<0.05). ODI significantly correlated with central chemosensitivity to carbon dioxide. Moreover, there was a highly significant correlation between WR and central chemosensitivity (r=0.65, p<0.05). However, there was no correlation between ODI and the WR (r=0.36, p=0.11). Cardiac sympathetic nerve activity in patients with CHF and CSAS is

  14. Unique chemosensitivity of MAC 16 tumours to flavone acetic acid (LM975, NSC 347512).

    OpenAIRE

    Bibby, M. C.; Double, J A; Loadman, P.M.

    1988-01-01

    MAC 16 is one of a series of mouse colon tumours originally induced by dimethylhydrazine. It is a relatively slow growing subcutaneous adenocarcinoma which becomes necrotic as it grows and causes severe body wasting in the host. This study has indicated that the tumour is resistant to a large number of standard anti-cancer drugs but is highly responsive to the investigational agent flavone acetic acid (FAA). The levels of FAA achieved in tumours are lower than those necessary for activity in ...

  15. Chemosensitizing and cytotoxic effects of 2-deoxy-D-glucose on breast cancer cells

    Directory of Open Access Journals (Sweden)

    Zhang Fanjie

    2009-09-01

    Full Text Available Background: Accelerated glucose uptake for anerobic glycolysis is one of the major metabolic changes found in malignant cells. This property has been exploited for imaging malignancies and as a possible anticancer therapy. The nonmetabolizable glucose analog 2-deoxyglucose (2 DG interferes with glucose metabolism leading to breast cancer cell death. Aims: To determine whether 2DG can synergize with chemotherapeutic agents commonly used in breast cancer treatment and identify cellular characteristics associated with sensitivity to 2DG. Materials and Methods: SkBr3 breast cancer cells were incubated with varying concentrations of 5-fluorouracil (5FU, doxorubicin, cisplatin, cyclophosphamide, or herceptin with or without 2DG. Cell viability was measured using the MTT (3-(4,5-dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide assay. Results: Combining 2DG with doxorubicin, 5 FU, cyclophosphamide, and herceptin resulted in enhanced cell death compared with each agent alone, while in combination with cisplatin, the amount of cell death was additive. Mouse embryo fibroblasts (MEF mutated for p53 (-/- were 30% more sensitive to the cytotoxic effects of 2DG than the parental cell lines. Cells mutated for Bax/Bac, genes involved in protection from apoptosis, are slightly more sensitive than the parental cell lines. Conclusions: These results indicate that 2DG acts synergistically with specific chemotherapeutic agents in causing cell death and the class of chemicals most sensitive appear to be those which cause DNA damage.

  16. Uso de teste de químio-sensibilidade para escolha da quimioterapia adjuvante no câncer gástrico avançado Use of the chemosensitivity test to choose appropriate adjuvant chemotherapy for advanced gastric cancer

    Directory of Open Access Journals (Sweden)

    Wilson Shinjiro Matsuzaki

    2006-08-01

    Full Text Available OBJETIVO: Introduzir e familiarizar em nosso meio o uso do teste de químio-sensibilidade MTT avaliando a ação de agentes quimioterápicos sobre células tumorais de 30 doentes com câncer gástrico avançado. Correlacionar os resultados do teste MTT com os aspectos clínicos, anátomo-patológicos e estádio utlizando a mesma metodologia do estudo realizado em pacientes japoneses na Universidade de Keio, Japão. MÉTODO: Foi realizado o teste MTT em tumores de 30 pacientes com diagnóstico de adenocarcinoma gástrico, submetidos ao tratamento cirúrgico no Departamento de Cirurgia da Faculdade de Ciências Médicas da Santa Casa de São Paulo. Foram estudados in vitro os seguintes agentes quimioterápicos: mitomicina C, doxorrubicina, cisplatina e 5-fluorouracil. RESULTADOS: Os índices de atividade sobre células tumorais foram: 16,6% para a mitomicina C, 10,0% para a doxorrubicina, 6,6% para a cisplatina e 6,6% para o 5-fluorouracil. Os resultados do teste MTT não tiveram correlação com a idade, sexo, aspectos microscópicos e estádio (p0,05. CONCLUSÕES: A ação dos agentes quimioterápicos estudados sobre células tumorais do câncer gástrico foi baixa. Os resultados da ação dos quimioterápicos in vitro não apresentou correlação estatística com a idade, sexo, aspectos microscópicos e estádio destes doentes. Utilizando a mesma metodologia, tanto em nosso meio como em pacientes japoneses, a quimio-sensibilidade se mostrou baixa em ambos os estudos, podendo-se deduzir também que os resultados da químiosensibilidade independe da etnia. Com o surgimento de novos agentes quimioterápicos, a expectativa é grande para melhores resultados na prática clínica. Com a utilização e difusão do teste MTT em nosso meio, poder-se-á criar protocolos e estudos multicêntricos para selecionar os quimioterápicos a serem utlizados.BACKGROUND: Utilizing the MTT chemosensitivity test to evaluated the action of chemotherapeutic agents on

  17. DYSREGULATION OF ION HOMEOSTASIS BY ANTIFUNGAL AGENTS

    Directory of Open Access Journals (Sweden)

    RajiniRao

    2012-04-01

    Full Text Available Ion signaling and transduction networks are central to fungal development and virulence because they regulate gene expression, filamentation, host association and invasion, pathogen stress response and survival. Dysregulation of ion homeostasis rapidly mediates cell death, forming the mechanistic basis by which a growing number of amphipathic but structurally unrelated compounds elicit antifungal activity. Included in this group is carvacrol, a terpenoid phenol that is a prominent component of oregano and other plant essential oils. Carvacrol triggers an early dose dependent Ca2+ burst and long lasting pH changes in the model yeast S. cerevisiae. The distinct phases of ionic transients and a robust transcriptional response that overlaps with Ca2+ stress and nutrient starvation point to specific signaling events elicited by plant terpenoid phenols, rather than a non-specific lesion of the membrane as was previously considered. We discuss the potential use of plant essential oils and other agents that disrupt ion signaling pathways as chemosensitizers to augment conventional antifungal therapy, and to convert fungistatic drugs with strong safety profiles into fungicides.

  18. Outcome of ATP-based tumor chemosensitivity assay directed chemotherapy in heavily pre-treated recurrent ovarian carcinoma

    Directory of Open Access Journals (Sweden)

    Lamont Alan

    2003-07-01

    Full Text Available Abstract Background We wished to evaluate the clinical response following ATP-Tumor Chemosensitivity Assay (ATP-TCA directed salvage chemotherapy in a series of UK patients with advanced ovarian cancer. The results are compared with that of a similar assay used in a different country in terms of evaluability and clinical endpoints. Methods From November 1998 to November 2001, 46 patients with pre-treated, advanced ovarian cancer were given a total of 56 courses of chemotherapy based on in-vitro ATP-TCA responses obtained from fresh tumor samples or ascites. Forty-four patients were evaluable for results. Of these, 18 patients had clinically platinum resistant disease (relapse Results The overall response rate was 59% (33/56 per course of chemotherapy, including 12 complete responses, 21 partial responses, 6 with stable disease, and 15 with progressive disease. Two patients were not evaluable for response having received just one cycle of chemotherapy: if these were excluded the response rate is 61%. Fifteen patients are still alive. Median progression free survival (PFS was 6.6 months per course of chemotherapy; median overall survival (OAS for each patient following the start of TCA-directed therapy was 10.4 months (95% confidence interval 7.9–12.8 months. Conclusion The results show similar response rates to previous studies using ATP-TCA directed therapy in recurrent ovarian cancer. The assay shows high evaluability and this study adds weight to the reproducibility of results from different centres.

  19. Knockdown of astrocyte elevated gene-1 inhibits proliferation and enhancing chemo-sensitivity to cisplatin or doxorubicin in neuroblastoma cells

    Directory of Open Access Journals (Sweden)

    Xie Li

    2009-02-01

    Full Text Available Abstract Background Astrocyte elevated gene-1 (AEG-1 was originally characterized as a HIV-1-inducible gene in primary human fetal astrocyte. Recent studies highlight a potential role of AEG-1 in promoting tumor progression and metastasis. The aim of this study was to investigate if AEG-1 serves as a potential therapeutic target of human neuroblastoma. Methods We employed RNA interference to reduce AEG-1 expression in human neuroblastoma cell lines and analyzed their phenotypic changes. Results We found that the knockdown of AEG-1 expression in human neuroblastoma cells significantly inhibited cell proliferation and apoptosis. The specific downregulation induced cell arrest in the G0/G1 phase of cell cycle. In the present study, we also observed a significant enhancement of chemo-sensitivity to cisplatin and doxorubicin by knockdown of AEG-1. Conclusion Our study suggests that overexpressed AEG-1 enhance the tumorogenic properties of neuroblastoma cells. The inhibition of AEG-1 expression could be a new adjuvant therapy for neuroblastoma.

  20. Overexpression of human sperm protein 17 increases migration and decreases the chemosensitivity of human epithelial ovarian cancer cells

    International Nuclear Information System (INIS)

    Most deaths from ovarian cancer are due to metastases that are resistant to conventional therapies. But the factors that regulate the metastatic process and chemoresistance of ovarian cancer are poorly understood. In the current study, we investigated the aberrant expression of human sperm protein 17 (HSp17) in human epithelial ovarian cancer cells and tried to analyze its influences on the cell behaviors like migration and chemoresistance. Immunohistochemistry and immunocytochemistry were used to identify HSp17 in paraffin embedded ovarian malignant tumor specimens and peritoneal metastatic malignant cells. Then we examined the effect of HSp17 overexpression on the proliferation, migration, and chemoresistance of ovarian cancer cells to carboplatin and cisplatin in a human ovarian carcinoma cell line, HO8910. We found that HSp17 was aberrantly expressed in 43% (30/70) of the patients with primary epithelial ovarian carcinomas, and in all of the metastatic cancer cells of ascites from 8 patients. The Sp17 expression was also detected in the metastatic lesions the same as in ovarian lesions. None of the 7 non-epithelial tumors primarily developed in the ovaries was immunopositive for HSp17. Overexpression of HSp17 increased the migration but decreased the chemosensitivity of ovarian carcinoma cells to carboplatin and cisplatin. HSp17 is aberrantly expressed in a significant proportion of epithelial ovarian carcinomas. Our results strongly suggest that HSp17 plays a role in metastatic disease and resistance of epithelial ovarian carcinoma to chemotherapy

  1. VEGFR3 Inhibition Chemosensitizes Ovarian Cancer Stemlike Cells through Down-Regulation of BRCA1 and BRCA2

    Directory of Open Access Journals (Sweden)

    Jaeyoung Lim

    2014-04-01

    Full Text Available In ovarian cancer, loss of BRCA gene expression in tumors is associated with improved response to chemotherapy and increased survival. A means to pharmacologically downregulate BRCA gene expression could improve the outcomes of patients with BRCA wild-type tumors. We report that vascular endothelial growth factor receptor 3 (VEGFR3 inhibition in ovarian cancer cells is associated with decreased levels of both BRCA1 and BRCA2. Inhibition of VEGFR3 in ovarian tumor cells was associated with growth arrest. CD133+ ovarian cancer stemlike cells were preferentially susceptible to VEGFR3-mediated growth inhibition. VEGFR3 inhibition–mediated down-regulation of BRCA gene expression reversed chemotherapy resistance and restored chemosensitivity in resistant cell lines in which a BRCA2 mutation had reverted to wild type. Finally, we demonstrate that tumor-associated macrophages are a primary source of VEGF-C in the tumor microenvironment. Our studies suggest that VEGFR3 inhibition may be a pharmacologic means to downregulate BRCA genes and improve the outcomes of patients with BRCA wild-type tumors.

  2. VEGFR3 Inhibition Chemosensitizes Ovarian Cancer Stemlike Cells through Down-Regulation of BRCA1 and BRCA212

    Science.gov (United States)

    Lim, Jaeyoung; Yang, Kun; Taylor-Harding, Barbie; Wiedemeyer, W. Ruprecht; Buckanovich, Ronald J.

    2014-01-01

    In ovarian cancer, loss of BRCA gene expression in tumors is associated with improved response to chemotherapy and increased survival. A means to pharmacologically downregulate BRCA gene expression could improve the outcomes of patients with BRCA wild-type tumors. We report that vascular endothelial growth factor receptor 3 (VEGFR3) inhibition in ovarian cancer cells is associated with decreased levels of both BRCA1 and BRCA2. Inhibition of VEGFR3 in ovarian tumor cells was associated with growth arrest. CD133+ ovarian cancer stemlike cells were preferentially susceptible to VEGFR3-mediated growth inhibition. VEGFR3 inhibition–mediated down-regulation of BRCA gene expression reversed chemotherapy resistance and restored chemosensitivity in resistant cell lines in which a BRCA2 mutation had reverted to wild type. Finally, we demonstrate that tumor-associated macrophages are a primary source of VEGF-C in the tumor microenvironment. Our studies suggest that VEGFR3 inhibition may be a pharmacologic means to downregulate BRCA genes and improve the outcomes of patients with BRCA wild-type tumors. PMID:24862760

  3. A Serial Analysis of Gene Expression (SAGE) database analysis of chemosensitivity

    DEFF Research Database (Denmark)

    Stein, Wilfred D; Litman, Thomas; Fojo, Tito;

    2004-01-01

    Drug sensitivity and resistance has been most extensively studied in cell lines carried in tissue culture. Furthermore, cell lines have been widely used in testing new anticancer agents, despite the widely recognized observation that cell lines are more sensitive to cytotoxic drugs than are their...... corresponding solid tumors. We used the Serial Analysis of Gene Expression (SAGE) database to identify differences between solid tumors and cell lines, hoping to detect genes that could potentially explain differences in drug sensitivity. SAGE libraries were available for both solid tumors and cell lines from...

  4. Critical role for BRCA1 expression as a marker of chemosensitivity response and prognosis.

    Science.gov (United States)

    De Luca, Paola; De Siervi, Adriana

    2016-01-01

    Chemotherapy is still the leader option for cancer treatment. Nevertheless some patients develop chemotherapy resistance. One major research goal is to identify the critical genes involved in chemotherapy response to predict the best therapy option for patients. Germline mutations in the BReast Cancer susceptibility gene (BRCA1) are associated to increased risk of developing breast, ovarian and other types of cancers. However, due to harmful BRCA1 gene mutations are relatively rare in the general population, nowadays most researchers focused on BRCA1 expression downregulation and/or epigenetic inactivation in sporadic tumors as a prognosis tool for chemotherapy response in patients. Chemotherapy response can be dramatically different depending on BRCA1 expression status, tumor type and drug. Hence, the chemotherapy response could be dissimilar in breast, ovarian, uterine, prostate, esophageal, gastric and lung cancers. Additionally, differential BRCA1 expression in sporadic tumors shows different response to DNA-damaging agents, mitotic inhibitors or PARP inhibitors. In this review we will examine the response to different chemotherapy agents in several cancer types depending on BRCA1 expression status. PMID:26709647

  5. ATP-TCA检测乳腺癌细胞对体外化疗药物敏感性的研究%Chemosensitivity in Vitro by ATP-TPC in Patients with Breast Cancer

    Institute of Scientific and Technical Information of China (English)

    张大庆; 崔振; 余辉; 陈凯; 余建军

    2012-01-01

    Objective To measure the appropriate chemotherapeutic agents on breast cancer cells in vitro by ATP - TCA and to evaluate the possibility of individual chemotherapy of breast cancer patients. Methods The study included 35 women with breast cancer who were subjected to modified radical mastectomy. All patients were initially treated, without adjuvant chemotherapy and radiotherapy. Tumor tissue were cultured with 9 kinds of chemotherapeutic agents at respective peak plasma concentration with three repeats for 3-5 days. The inhibition rate of the samples was measured by ATP bioluminescence assay. Results 32 of 35 assays completed successfully with ATP - TCA, with a evaluability rate of 91. 4% . The assay results suggested that 32 specimens from different breast cancer patients responded to chemotherapeutic drugs with individualized profiles. The most effective drug in the experiment was Adriamycin , and then Docetaxel, Paclitaxel, Vinorelbine, 5 - Fluorouracil, Cis - platinum and Gemcitabine, the rates of chemosensitivity of which were 81. 2% , 68.8% ,59.4% ,43.8% ,34.4%,31.2% and 25% respectively. While Methotrexate and Etoposide ( VP-16) were almost weakly active or resistive(0&12. 5% ) . Conclusion The anthracycline and taxane chemotherapeutic program has a better consistence of breast cancer in vitro chemosensitivity test. The vitro susceptibility test may provide the experimental basis for the implementation of the individual chemotherapeutic drugs.%目的 ATP-TCA检测乳腺癌患者肿瘤细胞对化疗药物的敏感性,评价本方法指导乳腺癌个体化疗的可行性.方法 35例行乳腺癌改良根治术患者纳入本研究,术中取新鲜无菌肿瘤组织,进行原代细胞培养,分别加入9种化疗药物,采用 ATP-TCA 测定药物对肿瘤细胞的抑制情况.结果 35例标本中32例完成药敏检测,标本的可评价率为91.4%.患者对化疗药物的体外敏感性存在个体差异,乳腺癌细胞对ADM

  6. A Probe into the International Verification Mechanism of CTBT%《全面禁止核试验条约》国际核查机制研究

    Institute of Scientific and Technical Information of China (English)

    郝发辉

    2013-01-01

    国际核不扩散体系的构成在防止核扩散中发挥着巨大的作用,《全面禁止核试验条约》对于核不扩散体系具有里程碑式的意义,条约最大的成果就是建立了国际核查机制,以科学技术为基础建立起来的国际核查机制在建立和发展过程中不仅受着国际政治和管理等多方面的影响,科学技术的发展和进步也很大程度上影响着国际核查机制的建设。本文叙述了以科学技术为基础建立起来的国际核查机制及目前的建设和运行情况,分析了科学技术对国际核查机制的作用,阐明了《全面禁止核试验条约》所确立的国际核查机制在国际大环境中的发展情况。%International system of non -proliferation of nuclear weapons plays a significant role in preventing the spread of nucle -ar weapons.The Comprehensive Nuclear -Test-Ban Treaty (CTBT) serves as a milestone in the system of non -proliferation of nuclear weapons , with its greatest achievement in establishing the international verification mechanism .Throughout the construc-tion, establishment and development process of the international verification mechanism , which is built upon science and technol-ogy, it is affected not only by international politics and administration , but also the advancement and progress of science and tech-nology .This article describes current construction and operation status of CTBT's science-and technology -oriented internation-al verification mechanism , and analyzes the effects it bears from science and technology , and finally , states the development situ-ation of CTBT's international verification mechanism with reference to the macro international environment .

  7. Increased chemosensitivity of paclitaxel by telomeric fusion-induced genomic instability

    Energy Technology Data Exchange (ETDEWEB)

    Woo, Seon Rang; Juhn, Kyoung Mi; Park, Jeong Eun; Ju, Yeun Jin; Yun, Mi Yong; Lee, Kee Ho [Korea Institute of Radiological and Medical Sciences, Seoul (Korea, Republic of); Park, Gil Hong; Kim, Joon [College of Medicine, Korea University, Seoul (Korea, Republic of)

    2009-05-15

    A telomere is a region of repetitive DNA at the end of chromosomes. They protect a cell's chromosomes from fusing with each other or rearranging and so cells are normally destroyed when their telomeres are consumed. Most normal somatic cells lose telomeric repeats after each cell division. Telomeric shortening in humans can induce replicative senescence which blocks cell division. This mechanism appears to prevent genomic instability by limiting the number of cell divisions. Telomerase is an attractive molecular target, since its activity has been found in more than 85% of human cancers. Combination therapy with chemotherapeutic agent is superior to single in overall response rate and progression free survival. In this study, we showed that telomerase null cells are more hypersensitive by paclitaxel treatment than at wild type cells.

  8. Agent, autonomous

    OpenAIRE

    Luciani, Annie

    2007-01-01

    The expression autonomous agents, widely used in virtual reality, computer graphics, artificial intelligence and artificial life, corresponds to the simulation of autonomous creatures, virtual (i.e. totally computed by a program), or embodied in a physical envelope, as done in autonomous robots.

  9. Knockdown of dual specificity phosphatase 4 enhances the chemosensitivity of MCF-7 and MCF-7/ADR breast cancer cells to doxorubicin

    International Nuclear Information System (INIS)

    Background: Breast cancer is the major cause of cancer-related deaths in females world-wide. Doxorubicin-based therapy has limited efficacy in breast cancer due to drug resistance, which has been shown to be associated with the epithelial-to-mesenchymal transition (EMT). However, the molecular mechanisms linking the EMT and drug resistance in breast cancer cells remain unclear. Dual specificity phosphatase 4 (DUSP4), a member of the dual specificity phosphatase family, is associated with cellular proliferation and differentiation; however, its role in breast cancer progression is controversial. Methods: We used cell viability assays, Western blotting and immunofluorescent staining, combined with siRNA interference, to evaluate chemoresistance and the EMT in MCF-7 and adriamycin-resistant MCF-7/ADR breast cancer cells, and investigate the underlying mechanisms. Results: Knockdown of DUSP4 significantly increased the chemosensitivity of MCF-7 and MCF-7/ADR breast cancer cells to doxorubicin, and MCF-7/ADR cells which expressed high levels of DUSP4 had a mesenchymal phenotype. Furthermore, knockdown of DUSP4 reversed the EMT in MCF-7/ADR cells, as demonstrated by upregulation of epithelial biomarkers and downregulation of mesenchymal biomarkers, and also increased the chemosensitivity of MCF-7/ADR cells to doxorubicin. Conclusions: DUSP4 might represent a potential drug target for inhibiting drug resistance and regulating the process of the EMT during the treatment of breast cancer. - Highlights: • We used different technologies to prove our conclusion. • DUSP4 knockdown increased doxorubicin chemosensitivity in breast cancer cells. • DUSP4 is a potential target for combating drug resistance in breast cancer. • DUSP4 is a potential target for regulating the EMT in breast cancer

  10. Knockdown of dual specificity phosphatase 4 enhances the chemosensitivity of MCF-7 and MCF-7/ADR breast cancer cells to doxorubicin

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Yu; Du, Feiya; Chen, Wei; Yao, Minya; Lv, Kezhen; Fu, Peifen, E-mail: fupeifendoczju@163.com

    2013-12-10

    Background: Breast cancer is the major cause of cancer-related deaths in females world-wide. Doxorubicin-based therapy has limited efficacy in breast cancer due to drug resistance, which has been shown to be associated with the epithelial-to-mesenchymal transition (EMT). However, the molecular mechanisms linking the EMT and drug resistance in breast cancer cells remain unclear. Dual specificity phosphatase 4 (DUSP4), a member of the dual specificity phosphatase family, is associated with cellular proliferation and differentiation; however, its role in breast cancer progression is controversial. Methods: We used cell viability assays, Western blotting and immunofluorescent staining, combined with siRNA interference, to evaluate chemoresistance and the EMT in MCF-7 and adriamycin-resistant MCF-7/ADR breast cancer cells, and investigate the underlying mechanisms. Results: Knockdown of DUSP4 significantly increased the chemosensitivity of MCF-7 and MCF-7/ADR breast cancer cells to doxorubicin, and MCF-7/ADR cells which expressed high levels of DUSP4 had a mesenchymal phenotype. Furthermore, knockdown of DUSP4 reversed the EMT in MCF-7/ADR cells, as demonstrated by upregulation of epithelial biomarkers and downregulation of mesenchymal biomarkers, and also increased the chemosensitivity of MCF-7/ADR cells to doxorubicin. Conclusions: DUSP4 might represent a potential drug target for inhibiting drug resistance and regulating the process of the EMT during the treatment of breast cancer. - Highlights: • We used different technologies to prove our conclusion. • DUSP4 knockdown increased doxorubicin chemosensitivity in breast cancer cells. • DUSP4 is a potential target for combating drug resistance in breast cancer. • DUSP4 is a potential target for regulating the EMT in breast cancer.

  11. Reactive oxygen species-mediated apoptosis contributes to chemosensitization effect of saikosaponins on cisplatin-induced cytotoxicity in cancer cells

    Directory of Open Access Journals (Sweden)

    He Fan

    2010-12-01

    Full Text Available Abstract Background Saikosaponin-a and -d, two naturally occurring compounds derived from Bupleurum radix, have been shown to exert anti-cancer activity in several cancer cell lines. However, the effect of combination of saikosaponins with chemotherapeutic drugs has never been addressed. Thus, we investigated whether these two saikosaponins have chemosensitization effect on cisplatin-induced cancer cell cytotoxicity. Methods Two cervical cancer cell lines, HeLa and Siha, an ovarian cancer cell line, SKOV3, and a non-small cell lung cancer cell line, A549, were treated with saikosaponins or cisplatin individually or in combination. Cell death was quantitatively detected by the release of lactate dehydrogenase (LDH using a cytotoxicity detection kit. Cellular ROS was analyzed by flow cytometry. Apoptosis was evaluated by AO/EB staining, flow cytometry after Anexin V and PI staining, and Western blot for caspase activation. ROS scavengers and caspase inhibitor were used to determine the roles of ROS and apoptosis in the effects of saikosaponins on cisplatin-induced cell death. Results Both saikosaponin-a and -d sensitized cancer cells to cisplatin-induced cell death in a dose-dependent manner, which was accompanied with induction of reactive oxygen species (ROS accumulation. The dead cells showed typical apoptotic morphologies. Both early apoptotic and late apoptotic cells detected by flow cytometry were increased in saikosaponins and cisplatin cotreated cells, accompanied by activation of the caspase pathway. The pan-caspase inhibitor z-VAD and ROS scanvengers butylated hydroxyanisole (BHA and N-acetyl-L-cysteine (NAC dramatically suppressed the potentiated cytotoxicity achieved by combination of saikosaponin-a or -d and cisplatin. Conclusions These results suggest that saikosaponins sensitize cancer cells to cisplatin through ROS-mediated apoptosis, and the combination of saikosaponins with cisplatin could be an effective therapeutic strategy.

  12. Expression of TP53 isoforms p53β or p53γ enhances chemosensitivity in TP53(null) cell lines.

    Science.gov (United States)

    Silden, Elisabeth; Hjelle, Sigrun M; Wergeland, Line; Sulen, André; Andresen, Vibeke; Bourdon, Jean-Christophe; Micklem, David R; McCormack, Emmet; Gjertsen, Bjørn Tore

    2013-01-01

    The carboxy-terminal truncated p53 alternative spliced isoforms, p53β and p53γ, are expressed at disparate levels in cancer and are suggested to influence treatment response and therapy outcome. However, their functional role in cancer remains to be elucidated. We investigated their individual functionality in the p53(null) background of cell lines H1299 and SAOS-2 by stable retroviral transduction or transient transfection. Expression status of p53β and p53γ protein was found to correlate with increased response to camptothecin and doxorubicin chemotherapy. Decreased DNA synthesis and clonogenicity in p53β and p53γ congenic H1299 was accompanied by increased p21((CIP1/WAF1)), Bax and Mdm2 proteins. Chemotherapy induced p53 isoform degradation, most prominent for p53γ. The proteasome inhibitor bortezomib substantially increased basal p53γ protein level, while the level of p53β protein was unaffected. Treatment with dicoumarol, a putative blocker of the proteasome-related NAD(P)H quinone oxidoreductase NQO1, effectively attenuated basal p53γ protein level in spite of bortezomib treatment. Although in vitro proliferation and clonogenicity assays indicated a weak suppressive effect by p53β and p53γ expression, studies of in vivo subcutaneous H1299 tumor growth demonstrated a significantly increased growth by expression of either p53 isoforms. This study suggests that p53β and p53γ share functionality in chemosensitizing and tumor growth enhancement but comprise distinct regulation at the protein level. PMID:23409163

  13. PKM2 enhances chemosensitivity to cisplatin through interaction with the mTOR pathway in cervical cancer.

    Science.gov (United States)

    Zhu, Haiyan; Wu, Jun; Zhang, Wenwen; Luo, Hui; Shen, Zhaojun; Cheng, Huihui; Zhu, Xueqiong

    2016-01-01

    Pyruvate kinase M2 (PKM2) is a key driver of aerobic glycolysis in cancer cells and has been shown to be up-regulated by mTOR in vitro. Our previous proteomic profiling studies showed that PKM2 was significantly upregulated in cervical cancer tissues after treatment with neoadjuvant chemotherapy (NACT). Whether PKM2 expression predicts cisplatin-based NACT sensitivity and is mTOR dependent in cervical cancer patients remains unclear. Using paired tumor samples (pre- and post-chemotherapy) from 36 cervical cancer patients, we examined mTOR, HIF-1α, c-Myc, and PKM2 expression in cervical cancer samples and investigated the response to cisplatin-based NACT. In addition, we established PKM2 suppressed cervical cancer cell lines and evaluated their sensitivity to cisplatin in vitro. We found that the mTOR/HIF-1α/c-Myc/PKM2 signaling pathway was significantly downregulated in post-chemotherapy cervical cancer tissues. High levels of mTOR, HIF-1α, c-Myc, and PKM2 were associated with a positive chemotherapy response in cervical cancer patients treated with cisplatin-based NACT. In vitro, PKM2 knockdown desensitized cervical cancer cells to cisplatin. Moreover, PKM2 had complex interactions with mTOR pathways. mTOR, HIF1α, c-Myc, and PKM2 expression in cervical cancer may serve as predictive biomarkers to cisplatin-based chemotherapy. PKM2 enhances chemosensitivity to cisplatin through interaction with the mTOR pathway in cervical cancer. PMID:27492148

  14. Expression of TP53 isoforms p53β or p53γ enhances chemosensitivity in TP53(null cell lines.

    Directory of Open Access Journals (Sweden)

    Elisabeth Silden

    Full Text Available The carboxy-terminal truncated p53 alternative spliced isoforms, p53β and p53γ, are expressed at disparate levels in cancer and are suggested to influence treatment response and therapy outcome. However, their functional role in cancer remains to be elucidated. We investigated their individual functionality in the p53(null background of cell lines H1299 and SAOS-2 by stable retroviral transduction or transient transfection. Expression status of p53β and p53γ protein was found to correlate with increased response to camptothecin and doxorubicin chemotherapy. Decreased DNA synthesis and clonogenicity in p53β and p53γ congenic H1299 was accompanied by increased p21((CIP1/WAF1, Bax and Mdm2 proteins. Chemotherapy induced p53 isoform degradation, most prominent for p53γ. The proteasome inhibitor bortezomib substantially increased basal p53γ protein level, while the level of p53β protein was unaffected. Treatment with dicoumarol, a putative blocker of the proteasome-related NAD(PH quinone oxidoreductase NQO1, effectively attenuated basal p53γ protein level in spite of bortezomib treatment. Although in vitro proliferation and clonogenicity assays indicated a weak suppressive effect by p53β and p53γ expression, studies of in vivo subcutaneous H1299 tumor growth demonstrated a significantly increased growth by expression of either p53 isoforms. This study suggests that p53β and p53γ share functionality in chemosensitizing and tumor growth enhancement but comprise distinct regulation at the protein level.

  15. Altered features and increased chemosensitivity of human breast cancer cells mediated by adipose tissue-derived mesenchymal stromal cells

    International Nuclear Information System (INIS)

    Mesenchymal stromal cells (MSCs) represent heterogeneous cell population suitable for cell therapies in regenerative medicine. MSCs can also substantially affect tumor biology due to their ability to be recruited to the tumor stroma and interact with malignant cells via direct contacts and paracrine signaling. The aim of our study was to characterize molecular changes dictated by adipose tissue-derived mesenchymal stromal cells (AT-MSCs) and the effects on drug responses in human breast cancer cells SKBR3. The tumor cells were either directly cocultured with AT-MSCs or exposed to MSCs-conditioned medium (MSC-CM). Changes in cell biology were evaluated by kinetic live cell imaging, fluorescent microscopy, scratch wound assay, expression analysis, cytokine secretion profiling, ATP-based viability and apoptosis assays. The efficiency of cytotoxic treatment in the presence of AT-MSCs or MSCs-CM was analyzed. The AT-MSCs altered tumor cell morphology, induced epithelial-to-mesenchymal transition, increased mammosphere formation, cell confluence and migration of SKBR3. These features were attributed to molecular changes induced by MSCs-secreted cytokines and chemokines in breast cancer cells. AT-MSCs significantly inhibited the proliferation of SKBR3 cells in direct cocultures which was shown to be dependent on the SDF-1α/CXCR4 signaling axis. MSC-CM-exposed SKBR3 or SKBR3 in direct coculture with AT-MSCs exhibited increased chemosensitivity and induction of apoptosis in response to doxorubicin and 5-fluorouracil. Our work further highlights the multi-level nature of tumor-stromal cell interplay and demonstrates the capability of AT-MSCs and MSC-secreted factors to alter the anti-tumor drug responses

  16. P-glycoprotein inhibitors of natural origin as potential tumor chemo-sensitizers: A re

    Directory of Open Access Journals (Sweden)

    Hossam M. Abdallah

    2015-01-01

    Full Text Available Resistance of solid tumors to treatment is significantly attributed to pharmacokinetic reasons at both cellular and multi-cellular levels. Anticancer agent must be bio-available at the site of action in a cytotoxic concentration to exert its proposed activity. P-glycoprotein (P-gp is a member of the ATP-dependent membrane transport proteins; it is known to pump substrates out of cells in ATP-dependent mechanism. The over-expression of P-gp in tumor cells reduces the intracellular drug concentrations, which decreases the cytotoxicity of a broad spectrum of antitumor drugs. Accordingly, P-gp inhibitors/blockers are potential enhancer for the cellular bioavailability of several clinically important anticancer drugs such as, anthracyclines, taxanes, vinca alkaloids, and podophyllotoxins. Besides several chemically synthesized P-gp inhibitors/blockers, some naturally occurring compounds and plant extracts were reported for their modulation of multidrug resistance; however, this review will focus only on major classes of naturally occurring inhibitors viz., flavonoids, coumarins, terpenoids, alkaloids and saponins.

  17. Clinical Impact of a Novel MicroRNA Chemo-Sensitivity Predictor in Gastrooesophageal Cancer

    Science.gov (United States)

    Winther, Mette; Knudsen, Steen; Dahlgaard, Jesper; Jensen, Thomas; Hansen, Anker; Jensen, Peter Buhl; Tramm, Trine; Alsner, Jan; Nordsmark, Marianne

    2016-01-01

    Background miRNAs might be potentially useful biomarkers for prediction of response to chemotherapeutic agents, radiotherapy and survival. The aim of this retrospective study was to validate miRNA response predictors in a cohort of patients with gastrooesophageal cancer in order to predict overall survival (OS) and disease-specific survival (DSS). Material and Methods The study population encompassed 53 patients treated with curative intend for loco-regional gastrooesophageal cancer. miRNA expression was quantified from pre-therapeutic and diagnostic, formalin-fixed, paraffin embedded tumour specimens using Affymetrix GeneChip miRNA 1.0 Array. Based on growth inhibition of the NCI60 panel in the presence of cisplatin, epirubicine and capecitabine, a miRNA based response predictor was developed. The Cox proportional hazards model was applied to assess the correlations of the response predictor with OS and DSS. Results A univariate analysis demonstrated a statistical significant improvement of OS for patients who had undergone surgical resection with prediction scores above the median prediction score (HR: 0.41 (95% CI: 0.17–0.96). Adjusting for surgery and stage, this predictor was identified to be independently associated with both OS (HR: 0.37 (95% CI: 0.16–0.87)) and DSS (HR: 0.32 (0.12–0.87)). Conclusion The miRNA profile predictive for sensitivity to cisplatin, epirubicine and capecitabine was shown to be independently associated with OS and DSS in patients with gastrooesophageal cancer. PMID:26885979

  18. Antifungal agents.

    Science.gov (United States)

    Ryder, N S

    1999-12-01

    At this year's ICAAC Meeting, new data on approximately 20 different antifungal agents were presented, while no new agents were disclosed. Drugs in late development include the triazoles, voriconazole (Pfizer Ltd) and Sch-56592 (Schering-Plough Corp), and the echinocandins, caspofungin (Merck & Co Inc) and FK-463 (Fujisawa Pharmaceutical Co Ltd). In contrast to previous years, presentations on these and earlier developmental compounds were relatively modest in scope, with few significant new data. Little new information appeared on the most recent novel class of agents, the sordarins (Glaxo Wellcome plc). Early clinical results were presented for FK-463, showing acceptable tolerability and dose-dependent efficacy in AIDS-associated esophageal candidiasis. A new liposomal formulation of nystatin (Nyotran; Aronex Pharmaceuticals Inc) was shown to be equivalent to conventional amphotericin B in empiric therapy of presumed fungal infection in neutropenic patients, but with reduced toxicity. Intravenous itraconazole (Janssen Pharmaceutica NV) was an effective prophylactic therapy in invasive pulmonary aspergillosis, while oral itraconazole was discussed as a treatment for fungal infection in heart and liver transplant patients. The allylamine compound, terbinafine (Novartis AG), showed good clinical efficacy against fungal mycetoma, a serious tropical infection. A major highlight was the first presentation of inhibitors of fungal efflux pumps as a strategy for overcoming resistance. MC-510027 (milbemycin alpha-9; Microcide Pharmaceuticals Inc) and its derivatives, potentiated the antifungal activity of triazoles and terbinafine in a number of Candida spp. Another pump inhibitor, MC-005172 (Microcide Pharmaceuticals Inc) showed in vivo potentiation of fluconazole in a mouse kidney infection model. Microcide Pharmaceuticals Inc also presented inhibitors of bacterial efflux pumps. PMID:16113946

  19. Trading Agents

    CERN Document Server

    Wellman, Michael

    2011-01-01

    Automated trading in electronic markets is one of the most common and consequential applications of autonomous software agents. Design of effective trading strategies requires thorough understanding of how market mechanisms operate, and appreciation of strategic issues that commonly manifest in trading scenarios. Drawing on research in auction theory and artificial intelligence, this book presents core principles of strategic reasoning that apply to market situations. The author illustrates trading strategy choices through examples of concrete market environments, such as eBay, as well as abst

  20. Using 99mTc-MIBI to Evaluate the Effects of Chemosensitizer on P-glycoprotein in Multidrug-resistant Carcinoma Cells

    Institute of Scientific and Technical Information of China (English)

    ZHANGZhenwei; ZHANGXuemei; WUHua; ZHAOMing; XIANYUZhiqun; ZHOUJian; LAIShiying

    2005-01-01

    Objective: To establish a method to evaluate the effects of chemosensitizer on P-glycoprotein using 99mTc-MIBI, and observe the changes of 99mTc-MIBI uptake kinetics and P-glycoprotein levels after using verapamil in MDR human breast cells MCF-7/Adr. Methods: MDR breast carcinoma cells, MCF-7/Adr, were incubated and different protocols were performed. Protocol I: a chemosensitizer, verapamil (10μmol/L), was added into cell culture medium, while in control group, the same volume of DMEM was given. Cells were harvested after 2 h incubation with 99mTc-MIBI. Protocol Ⅱ: Verapamil (10μmol/L) was added into cell culture medium and incubated for 20 min, 40 min, 60 rain, 80 min, 8 h, 24 h, 48 h and 72 h respectively. Cells were harvested after 2 h incubation with 99mTc-MIBI. The radioactivity of the cells was measured and P-glycoprotein expression levels were determined with immunohistochemical stain. Results: Protocol I: After 2h incubation with verapamil the cellular uptake of 99mTc-MIBI was remarkably higher than control group (t=2.33, P0.05). Protocol

  1. B7-H3 silencing by RNAi inhibits tumor progression and enhances chemosensitivity in U937 cells

    Directory of Open Access Journals (Sweden)

    Zhang W

    2015-07-01

    function of B7-H3 and a promising therapeutic approach targeting B7-H3 in acute monocytic leukemia. Keywords: B7-H3, acute monocytic leukemia, cancer gene therapy, chemosensitivity

  2. Radioprotective Agents

    Directory of Open Access Journals (Sweden)

    Ilker Kelle

    2008-01-01

    Full Text Available Since1949, a great deal of research has been carried out on the radioprotective activity of various chemical substances. Thiol compounds, compounds which contain –SH radical, different classes of pharmacological agents and other compounds such as vitamine C and WR-2721 have been shown to reduce mortality when administered prior to exposure to a lethal dose of radiation. Recently, honey bee venom as well as that of its components melittin and histamine have shown to be valuable in reduction of radiation-induced damage and also provide prophylactic alternative treatment for serious side effects related with radiotherapy. It has been suggested that the radioprotective activity of bee venom components is related with the stimulation of the hematopoetic system.

  3. An agent framework for dynamic agent retraining: Agent academy

    OpenAIRE

    Mitkas, P.; A. Symeonidis; Kechagias, D.; Athanasiadis, I.N.; Laleci, G.; KURT, G.; Kabak, Y.; Acar, A.; Dogac, A.

    2004-01-01

    Agent Academy (AA) aims to develop a multi-agent society that can train new agents for specific or general tasks, while constantly retraining existing agents in a recursive mode. The system is based on collecting information both from the environment and the behaviors of the acting agents and their related successes/failures to generate a body of data, stored in the Agent Use Repository, which is mined by the Data Miner module, in order to generate useful knowledge about the application domai...

  4. Expression of the apoptosis-related genes BCL-2 and BAD in human breast carcinoma and their associated relationship with chemosensitivity

    Directory of Open Access Journals (Sweden)

    Fan Yuan-ming

    2010-08-01

    Full Text Available Abstract Objective To evaluate the expression of BCL-2 and BAD genes in tissues of breast carcinoma and investigate the relationship between the expression of BCL-2 and BAD in breast cancer cells with chemosensitivity. Methods Immunohistochemical technique was used to detect the expression of BCL-2, BAD in 10 normal breast tissues, 10 breast fibroadenoma tissues, 40 youth human breast carcinoma tissues, 40 menopause human breast carcinoma tissues. And to detect the expression of ER, PR in 80 human breast carcinoma tissues. 20 Surgical samples of breast cancer, diagnosed by pathology, were obtained from The First Affiliated Hospital of Chongqing Medical University. The cancer sample cells were cultured separately in the incubator at 37°C, 5% CO2 in vitro. The rate of inhibition of cancer cells in 4 kinds of anticancer drugs-- Epirubicin Adriamycin (EADM,5-Fluorouracil (5-Fu, Navelbine(NVB and Diaminedichloroplatinum (DDP, were assayed by MTT method. Results The expression of BCL-2, BAD genes in young human breast carcinoma tissues were lower than that in menopause human breast carcinoma tissues (P . There was a negative correlation between the positive expression rate of BCL-2 and histologic grade or the lymph node metastasis (P . There was a positive correlation between the expression rates of BCL-2 and of ER, PR (P . The expression of BAD had no relationship with the expression of ER, PR, histologic grade and the lymph node metastasis(P = NS. Sensitivity rates of 20 breast cancer cells in 0.1 × PPC within 48 h in vitro were 30% EADM,20% 5-Fu,45% NVB and 25% DDP. Respectively, the rate of inhibition of EADM,5- Fu, NVB and DDP were significantly higher in the BCL-2 negative cancer cells than in the BCL-2 positive cancer cells. A negative correlation was found between expression of BCL-2 and chemosensitivity for all the 4 anticancer drugs. The inhibition rates of EADM and NVB were significantly lower in the BAD negative cancer cells than in the

  5. Overcoming chloroquine resistance in malaria: Design, synthesis and structure-activity relationships of novel chemoreversal agents.

    Science.gov (United States)

    Boudhar, Aicha; Ng, Xiao Wei; Loh, Chiew Yee; Chia, Wan Ni; Tan, Zhi Ming; Nosten, Francois; Dymock, Brian W; Tan, Kevin S W

    2016-08-25

    Malaria remains a significant infectious disease with even artemisinin-based therapies now facing resistance in the field. Development of new therapies is urgently needed, either by finding new compounds with unique modes of action, or by reversing resistance towards known drugs with 'chemosensitizers' or 'chemoreversal' agents (CRA). Concerning the latter, we have focused on the resistance mechanisms developed against chloroquine (CQ). We have synthesized a series of compounds related to previously identified CRAs, and found promising novel compounds. These compounds show encouraging results in a coumarin labeled chloroquine uptake assay, exhibiting a dose response in resensitising parasites to the antimalarial effects of chloroquine. Selected compounds show consistent potency across a panel of chloroquine and artemisinin sensitive and resistant parasites, and a wide therapeutic window. This data supports further study of CRAs in the treatment of malaria and, ultimately, their use in chloroquine-based combination therapies. PMID:27173385

  6. Growth-inhibitory and chemosensitizing effects of the glutathione-S-transferase-π-activated nitric oxide donor PABA/NO in malignant gliomas.

    Science.gov (United States)

    Kogias, Evangelos; Osterberg, Nadja; Baumer, Brunhilde; Psarras, Nikolaos; Koentges, Christoph; Papazoglou, Anna; Saavedra, Joseph E; Keefer, Larry K; Weyerbrock, Astrid

    2012-03-01

    Glutathione-S-transferases (GSTs) are upregulated in malignant gliomas and contribute to their chemoresistance. The nitric oxide (NO) donor PABA/NO (O(2) -{2,4-dinitro-5-[4-(N-methylamino)benzoyloxy]phenyl} 1-(N,N-dimethylamino)diazen-1-ium-1,2-diolate) generates NO upon selective enzymatic activation by GST-π-inducing selective biological effects in tumors. Tumor cell killing and chemosensitization were observed in a variety of tumors after exposure to GST-activated NO donor drugs. In our project, cytotoxic and chemosensitizing effects of PABA/NO in combination with carboplatin (CPT) and temozolomide (TMZ) were studied in human U87 glioma cells in vitro and in vivo. U87 glioma cells were exposed to PABA/NO alone or in combination with CPT or TMZ for 24 hr. Cell viability was assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay after 24-hr incubation and 48 hr after drug removal. The antiproliferative effect of PABA/NO was assessed in an intracranial U87 glioma nude rat model comparing subcutaneous administration and intratumoral delivery by convection-enhanced delivery. PABA/NO monotherapy showed a strong dose-dependent growth-inhibitory effect in U87 glioma cells in vitro, and a strong synergistic effect was observed after concomitant treatment with TMZ, but not with CPT. Systemic and intratumoral PABA/NO administration significantly reduced cell proliferation, but this did not result in prolonged survival in nude rats with intracranial U87 gliomas. PABA/NO has potent antiproliferative effects, sensitizes U87 glioma cells to TMZ in vitro and shows some in vivo efficacy. Further studies are still required to consolidate the role of NO donor therapy in glioma treatment. PMID:21455987

  7. Antitumor and chemosensitizing action of dichloroacetate implicates modulation of tumor microenvironment: A role of reorganized glucose metabolism, cell survival regulation and macrophage differentiation

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Ajay; Kant, Shiva; Singh, Sukh Mahendra, E-mail: sukhmahendrasingh@yahoo.com

    2013-11-15

    Targeting of tumor metabolism is emerging as a novel therapeutic strategy against cancer. Dichloroacetate (DCA), an inhibitor of pyruvate dehydrogenase kinase (PDK), has been shown to exert a potent tumoricidal action against a variety of tumor cells. The main mode of its antineoplastic action implicates a shift of glycolysis to oxidative metabolism of glucose, leading to generation of cytotoxic reactive oxygen intermediates. However, the effect of DCA on tumor microenvironment, which in turn regulates tumor cell survival; remains speculative to a large extent. It is also unclear if DCA can exert any modulatory effect on the process of hematopoiesis, which is in a compromised state in tumor-bearing hosts undergoing chemotherapy. In view of these lacunas, the present study was undertaken to investigate the so far unexplored aspects with respect to the molecular mechanisms of DCA-dependent tumor growth retardation and chemosensitization. BALB/c mice were transplanted with Dalton's lymphoma (DL) cells, a T cell lymphoma of spontaneous origin, followed by administration of DCA with or without cisplatin. DCA-dependent tumor regression and chemosensitization to cisplatin was found to be associated with altered repertoire of key cell survival regulatory molecules, modulated glucose metabolism, accompanying reconstituted tumor microenvironment with respect to pH homeostasis, cytokine balance and alternatively activated TAM. Moreover, DCA administration also led to an alteration in the MDR phenotype of tumor cells and myelopoietic differentiation of macrophages. The findings of this study shed a new light with respect to some of the novel mechanisms underlying the antitumor action of DCA and thus may have immense clinical applications. - Highlights: • DCA modulates tumor progression and chemoresistance. • DCA alters molecules regulating cell survival, glucose metabolism and MDR. • DCA reconstitutes biophysical and cellular composition of tumor microenvironment.

  8. Deregulation of MicroRNA-375 inhibits cancer proliferation migration and chemosensitivity in pancreatic cancer through the association of HOXB3

    Science.gov (United States)

    Yang, Dejun; Yan, Ronglin; Zhang, Xin; Zhu, Zhenxin; Wang, Changming; Liang, Chao; Zhang, Xin

    2016-01-01

    Background: The expression pattern and regulatory effect of microRNA-375 (miR-375) in human pancreatic cancer was explored. Methods: Gene expression of miR-375 was compared between pancreatic tumors and non-tumorous pancreatic tissues, as well as pancreatic cancer cell lines and normal epithelial cells. MiR-375 was downregulated in pancreatic cancer cell lines, Capan-1 and PANC-1 cells, to assess possible tumor suppressive effects on cancer proliferation, migration, cisplatin chemosensitivity and in vivo growth of tumor explant. The regulation of miR-375 on its target gene, homeobox B3 (HOXB3) gene, was assessed though luciferase activity assay and qRT-PCR. HOXB3 was also downregulated in Capan-1 and PANC-1 cells to assess its functional correlation with miR-375 on cancer regulation. Results: MiR-375 was upregulated in pancreatic tumors and pancreatic cancer cell lines. MiR-375 downregulation had tumor suppressive effects in Capan-1 and PANC-1 cells by reducing cancer proliferation & migration, increasing cisplatin sensitivity and inhibiting in vivo tumor explant growth. HOXB3 was directly bound by miR-375, and was negatively regulated by miR-375 in pancreatic cancer cells. Subsequent HOXB3 downregulation reversed the suppression of miR-375 downregulation on cancer proliferation, migration and cisplatin chemosensitivity in pancreatic cancer. Conclusion: MiR-375 is an oncogene in pancreatic cancer. Deregulation of miR-375 is inhibitory to the development of pancreatic cancer, and reversely regulated by HOXB3. PMID:27186281

  9. Antitumor and chemosensitizing action of dichloroacetate implicates modulation of tumor microenvironment: A role of reorganized glucose metabolism, cell survival regulation and macrophage differentiation

    International Nuclear Information System (INIS)

    Targeting of tumor metabolism is emerging as a novel therapeutic strategy against cancer. Dichloroacetate (DCA), an inhibitor of pyruvate dehydrogenase kinase (PDK), has been shown to exert a potent tumoricidal action against a variety of tumor cells. The main mode of its antineoplastic action implicates a shift of glycolysis to oxidative metabolism of glucose, leading to generation of cytotoxic reactive oxygen intermediates. However, the effect of DCA on tumor microenvironment, which in turn regulates tumor cell survival; remains speculative to a large extent. It is also unclear if DCA can exert any modulatory effect on the process of hematopoiesis, which is in a compromised state in tumor-bearing hosts undergoing chemotherapy. In view of these lacunas, the present study was undertaken to investigate the so far unexplored aspects with respect to the molecular mechanisms of DCA-dependent tumor growth retardation and chemosensitization. BALB/c mice were transplanted with Dalton's lymphoma (DL) cells, a T cell lymphoma of spontaneous origin, followed by administration of DCA with or without cisplatin. DCA-dependent tumor regression and chemosensitization to cisplatin was found to be associated with altered repertoire of key cell survival regulatory molecules, modulated glucose metabolism, accompanying reconstituted tumor microenvironment with respect to pH homeostasis, cytokine balance and alternatively activated TAM. Moreover, DCA administration also led to an alteration in the MDR phenotype of tumor cells and myelopoietic differentiation of macrophages. The findings of this study shed a new light with respect to some of the novel mechanisms underlying the antitumor action of DCA and thus may have immense clinical applications. - Highlights: • DCA modulates tumor progression and chemoresistance. • DCA alters molecules regulating cell survival, glucose metabolism and MDR. • DCA reconstitutes biophysical and cellular composition of tumor microenvironment.

  10. Tumor-derived hepatocyte growth factor is associated with poor prognosis of patients with glioma and influences the chemosensitivity of glioma cell line to cisplatin in vitro

    Directory of Open Access Journals (Sweden)

    Guo You-feng

    2012-06-01

    Full Text Available Abstract Background We examined the association of tumor-derived hepatocyte growth factor (HGF with the clinicopathological features of gliomas and investigated the effect of HGF inhibition on the biological behavior of tumor cells in vitro in order to determine whether HGF is a valuable prognostic predictor for glioma patients. Methods Seventy-six cases of glioma were collected. The tumor-derived HGF expression, cell proliferation index (PI and intratumoral microvessels were evaluated by immunohistochemistry. Correlation between immunostaining and clinicopathological parameters, as well as the follow-up data of patients, was analyzed statistically. U87MG glioma cells were transfected with short interference (si-RNA for HGF, and the cell viability, migratory ability and chemosensitivity to cisplatin were evaluated in vitro. Results Both high HGF expression in tumor cells (59.2%, 45/76 and high PI were significantly associated with high-grade glioma and increased microvessels in tumors (P P = 0.004 and high-expression of HGF (P = 0.008 emerged as independent prognostic factors for the overall survival of glioma patients. The tumor-derived HGF mRNA and protein expressions were significantly decreased in vitro after transfection of HGF siRNA. HGF siRNA inhibited the cell growth and reduced cell migratory ability. Moreover, HGF siRNA transfection enhanced the chemosensitivity of U87MG glioma cells to cisplatin. Conclusion This study indicated that there was significant correlation among tumor cell-derived HGF, cell proliferation and microvessel proliferation in gliomas. HGF might influence tumor progression by modulating the cell growth, migration and chemoresistance to drugs. Increased expression of HGF may be a valuable predictor for prognostic evaluation of glioma patients.

  11. ERCC1 and BRCA1 mRNA expression levels in metastatic malignant effusions is associated with chemosensitivity to cisplatin and/or docetaxel

    Directory of Open Access Journals (Sweden)

    Wang Tingting

    2008-04-01

    Full Text Available Abstract Background One of the major challenges in currently chemotherapeutic theme is lacking effective biomarkers for drug response and sensitivity. Our current study focus on two promising biomarkers, ERCC1 (excision repair cross-complementing group 1 and BRCA1 (breast cancer susceptibility gene 1. To investigate their potential role in serving as biomarkers for drug sensitivity in cancer patients with metastases, we statistically measure the mRNA expression level of ERCC1 and BRCA1 in tumor cells isolated from malignant effusions and correlate them with cisplatin and/or docetaxel chemosensitivity. Methods Real-time quantitative PCR is used to analysis related genes expression in forty-six malignant effusions prospectively collected from non-small cell lung cancer (NSCLC, gastric and gynecology cancer patients. Viable tumor cells obtained from malignant effusions are tested for their sensitivity to cisplatin and docetaxel using ATP-TCA assay. Results ERCC1 expression level is negatively correlated with the sensitivity to cisplatin in NSCLC patients (P = 0.001. In NSCLC and gastric group, BRCA1 expression level is negatively correlated with the sensitivity to cisplatin (NSCLC: P = 0.014; gastric: P = 0.002 while positively correlated with sensitivity to docetaxel (NSCLC: P = 0.008; gastric: P = 0.032. A significant interaction is found between ERCC1 and BRCA1 mRNA expressions on sensitivity to cisplatin (P = 0.010, n = 45. Conclusion Our results demonstrate that ERCC1 and BRCA1 mRNA expression levels are correlated with in vitro chemosensitivity to cisplatin and/or docetaxel in malignant effusions of NSCLC and gastric cancer patients. And combination of ERCC1 and BRCA1 may have a better role on predicting the sensitivity to cisplatin than the single one is considered.

  12. ERCC1 and BRCA1 mRNA expression levels in metastatic malignant effusions is associated with chemosensitivity to cisplatin and/or docetaxel

    International Nuclear Information System (INIS)

    One of the major challenges in currently chemotherapeutic theme is lacking effective biomarkers for drug response and sensitivity. Our current study focus on two promising biomarkers, ERCC1 (excision repair cross-complementing group 1) and BRCA1 (breast cancer susceptibility gene 1). To investigate their potential role in serving as biomarkers for drug sensitivity in cancer patients with metastases, we statistically measure the mRNA expression level of ERCC1 and BRCA1 in tumor cells isolated from malignant effusions and correlate them with cisplatin and/or docetaxel chemosensitivity. Real-time quantitative PCR is used to analysis related genes expression in forty-six malignant effusions prospectively collected from non-small cell lung cancer (NSCLC), gastric and gynecology cancer patients. Viable tumor cells obtained from malignant effusions are tested for their sensitivity to cisplatin and docetaxel using ATP-TCA assay. ERCC1 expression level is negatively correlated with the sensitivity to cisplatin in NSCLC patients (P = 0.001). In NSCLC and gastric group, BRCA1 expression level is negatively correlated with the sensitivity to cisplatin (NSCLC: P = 0.014; gastric: P = 0.002) while positively correlated with sensitivity to docetaxel (NSCLC: P = 0.008; gastric: P = 0.032). A significant interaction is found between ERCC1 and BRCA1 mRNA expressions on sensitivity to cisplatin (P = 0.010, n = 45). Our results demonstrate that ERCC1 and BRCA1 mRNA expression levels are correlated with in vitro chemosensitivity to cisplatin and/or docetaxel in malignant effusions of NSCLC and gastric cancer patients. And combination of ERCC1 and BRCA1 may have a better role on predicting the sensitivity to cisplatin than the single one is considered

  13. Agent Chameleons: Virtual Agents Real Intelligence

    OpenAIRE

    O'Hare, Gregory; Duffy, Brian; Schoen-Phelan, Bianca; Martin, Alan; Bradley, John

    2003-01-01

    Agent Chameleons provides virtual agents powered by real intelligence, delivering next generation autonomic entities that can seamlessly migrate, mutate and evolve on their journey between and within physical and digital information spaces.

  14. Preclinical Investigations of PM01183 (Lurbinectedin) as a Single Agent or in Combination with Other Anticancer Agents for Clear Cell Carcinoma of the Ovary

    Science.gov (United States)

    Takahashi, Ryoko; Mabuchi, Seiji; Kawano, Mahiru; Sasano, Tomoyuki; Matsumoto, Yuri; Kuroda, Hiromasa; Kozasa, Katsumi; Hashimoto, Kae; Sawada, Kenjiro; Kimura, Tadashi

    2016-01-01

    Objective The objective of this study was to evaluate the antitumor effects of lurbinectedin as a single agent or in combination with existing anticancer agents for clear cell carcinoma (CCC) of the ovary, which is regarded as an aggressive, chemoresistant, histological subtype. Methods Using human ovarian CCC cell lines, the antitumor effects of lurbinectedin, SN-38, doxorubicin, cisplatin, and paclitaxel as single agents were assessed using the MTS assay. Then, the antitumor effects of combination therapies involving lurbinectedin and 1 of the other 4 agents were evaluated using isobologram analysis to examine whether these combinations displayed synergistic effects. The antitumor activity of each treatment was also examined using cisplatin-resistant and paclitaxel-resistant CCC sublines. Finally, we determined the effects of mTORC1 inhibition on the antitumor activity of lurbinectedin-based chemotherapy. Results Lurbinectedin exhibited significant antitumor activity toward chemosensitive and chemoresistant CCC cells in vitro. An examination of mouse CCC cell xenografts revealed that lurbinectedin significantly inhibits tumor growth. Among the tested combinations, lurbinectedin plus SN-38 resulted in a significant synergistic effect. This combination also had strong synergistic effects on both the cisplatin-resistant and paclitaxel-resistant CCC cell lines. Everolimus significantly enhanced the antitumor activity of lurbinectedin-based chemotherapies. Conclusions Lurbinectedin, a new agent that targets active transcription, exhibits antitumor activity in CCC when used as a single agent and has synergistic antitumor effects when combined with irinotecan. Our results indicate that lurbinectedin is a promising agent for treating ovarian CCC, both as a first-line treatment and as a salvage treatment for recurrent lesions that develop after platinum-based or paclitaxel treatment. PMID:26986199

  15. Study of chemosensitivity testing in vitro on astrocytoma%星形细胞瘤体外化疗药物敏感程度的研究

    Institute of Scientific and Technical Information of China (English)

    滕晓华; 刘波; 周蓉; 曾年菊; 卢明

    2011-01-01

    目的 了解星形细胞瘤对常用化疗药物的敏感程度,探讨化疗药物体外敏感试验对于胶质瘤化疗的指导意义,比较不同WHO分级星形细胞瘤对化疗药物敏感度的差异,为临床治疗提供依据.方法 收集手术切除的新鲜星形细胞瘤标本共142例,其中低级别星形细胞瘤(Ⅰ、Ⅱ级)55例,高级别星形细胞瘤(Ⅲ、Ⅳ级)87例,分别进行星形细胞瘤细胞分离培养,采用MTT法检测临床常用11种化疗药物对肿瘤细胞的生长抑制情况,判定药物敏感程度.结果 142例患者中有78例(54.93%)获临床推荐使用药物,其中低级别星形细胞瘤为41.82%(23/55),而高级别星形细胞瘤为63.22%(55/87).不同WHO分级星形细胞瘤敏感化疗药物基本相似,以替尼泊苷、卡铂、长春新碱更为敏感.结论 化疗药物体外敏感试验对于胶质瘤的化疗药物筛选具有一定的指导意义,恶性程度越高,作用越突出.不同WHO分级的星形细胞瘤在化疗药物的选择上差异不明显.%Objective To observe the sensitivity ofastrocytoma to chemotherapeutic drugs, in order to explore the drug selection using chemosensitivity testing in vitro on astrocytoma. Comparing different WHO grade astrocytoma to chemotherapeutic drugs sensitivity differences,providing the basis data for clinical treatment. Methods The astrocytoma cells were seperated and cultured in vitro from 142 tumor tissues by glioma resection, including 55 cases of low-grade astrocytoma (WHO grade Ⅰ , Ⅱ) and 87 cases of high-grade astrocytoma (WHO grade Ⅲ, Ⅳ). The proliferation inhibition and chemosensitivity of tumor cells to 11 drugs were investigated by using MTT method. Results There were 54.93% (78/142) patients recommended chemotherapeutic drug in 142 cases. The percentage was 41.82%(23/55) in the low-grade astrocytoma, and 63.22% (55/87) in the high-grade astrocytoma respectively. Teniposide,carboplatin,vincristine as the sensitive drugs were similar in

  16. Current approaches to improve the anticancer chemotherapy with alkylating agents: state of the problem in world and Ukraine.

    Directory of Open Access Journals (Sweden)

    Iatsyshyna A. P.

    2012-01-01

    Full Text Available Alkylating agents are frequently used in many established anticancer chemotherapies. They alkylate the genomic DNA at various sites. Alkylation of the guanine at the O6-position is cytotoxic, it has the strongest mutagenic potential, as well as can cause the tumor development. Alkyl groups at the O6-position of guanine are removed by the DNA repair enzyme O6-methylguanine-DNA methyltransferase (MGMT. The effectiveness of alkylating chemotherapy is limited by MGMT in cancer cells and adverse toxic side effects in normal cells. Different approaches consisting in the modulation of the MGMT expression and activity are under development now to improve the cancer chemotherapy. They include two main directions, in particular, the increase in chemosensitivity of cancer cells to alkylating drugs and the protection of normal cells from the toxic side effects of chemotherapy. This review is focused on current attempts to improve the alkylating chemotherapy of malignant tumours worldwide and state of the issue in Ukraine

  17. MiR-92b regulates the cell growth, cisplatin chemosensitivity of A549 non small cell lung cancer cell line and target PTEN.

    Science.gov (United States)

    Li, Yan; Li, Li; Guan, Yan; Liu, Xiuju; Meng, Qingyong; Guo, Qisen

    2013-11-01

    MicroRNAs (miRNAs) have emerged to play important roles in tumorigenesis and drug resistance of human cancer. Fewer studies were explored the roles of miR-92b on human lung cancer cell growth and resistance to cisplatin (CDDP). In this paper, we utilized real-time PCR to verify miR-92b was significantly up-regulated in non-small cell lung cancer (NSCLC) tissues compared to matched adjacent normal tissues. In vitro assay demonstrated that knock-down of miR-92b inhabits cell growth and sensitized the A549/CDDP cells to CDDP. Furthermore, we found miR-92b could directly target PTEN, a unique tumor suppressor gene, which was downregulated in lung cancer tissues compared to the matched adjacent normal tissues. These data indicate that the miR-92b play an oncogene roles by regulates cell growth, cisplatin chemosensitivity phenotype, and could serve as a novel potential maker for NSCLC therapy. PMID:24099768

  18. Integration of photothermal therapy and synergistic chemotherapy by a porphyrin self-assembled micelle confers chemosensitivity in triple-negative breast cancer.

    Science.gov (United States)

    Su, Shishuai; Ding, Yanping; Li, Yiye; Wu, Yan; Nie, Guangjun

    2016-02-01

    Triple-negative breast cancer is a malignant cancer type with a high risk of early recurrence and distant metastasis. Unlike other breast cancers, triple-negative breast cancer is lack of targetable receptors and, therefore, patients largely receive systemic chemotherapy. However, inevitable adverse effects and acquired drug resistance severely constrain the therapeutic outcome. Here we tailor-designed a porphyrin-based micelle that was self-assembled from a hybrid amphiphilic polymer comprising polyethylene glycol, poly (d, l-lactide-co-glycolide) and porphyrin. The bilayer micelles can be simultaneously loaded with two chemotherapeutic drugs with synergistic cytotoxicity and distinct physiochemical properties, forming a uniform and spherical nanostructure. The drug-loaded micelles showed a tendency to accumulate in the tumor and can be internalized by tumor cells for drug release in acidic organelles. Under near-infrared laser irradiation, high density of self-quenched porphyrins in the hydrophobic layer absorbed light efficiently and converted into an excited state, leading to the release of sufficient heat for photothermal therapy. The integration of localized photothermal effect and synergistic chemotherapy conferred great chemosensitivity to cancer cells and achieved tumor regression using about 1/10 of traditional drug dosage. As a result, chemotherapy-associated adverse effects were successfully avoided. Our present study established a novel porphyrin-based nanoplatform with photothermal activity and expanded drug loading capacity, providing new opportunities for challenging conventional chemotherapy and fighting against stubborn triple-negative breast cancer. PMID:26708642

  19. Application value of ATP based bioluminescence tumor chemosensitivity assay in the chemotherapy for hydrothorax caused by non-small cell lung cancer

    Institute of Scientific and Technical Information of China (English)

    Kaijian Le; Yuming Jia; Jing Wang; Maoqiong Jiang

    2013-01-01

    Objective: The aim of the study was to investigate the clinical value and application of ATP based bioluminescencetumor chemosensitivity assay (ATP-TCA) in the chemotherapy for hydrothorax caused by non-small cell lung cancer(NSCLC). Methods: Hydrothorax specimens from 120 NSCLC patients were analyzed by ATP-TCA and the most sensitivechemotherapeutic drugs were used in NSCLC patients (treatment group). At the same time, 56 NSCLC patients with hydrothoraxwere admitted in our Hospital (Department of Oncology, The No. 2 People's Hospital of Yibin, China) and given chemotherapywithout guidance of the ATP-TCA (control group). Before the third chemotherapeutic cycle, clinical outcomes wereanalyzed in the two groups. Results: Effective rate of hydrothorax in treatment group was 67%, while 46% in control group(P < 0.05). In refractory hydrothorax patients, they were 69% and 40% (P < 0.05), respectively. In vitro results correlated wellwith clinical outcomes (P < 0.01). Conclusion: Effective rate of chemotherapy for hydrothorax in NSCLC is higher in treatmentgroup than that in control group. ATP-TCA is especially helpful for refractory hydrothorax.

  20. MKP1 mediates chemosensitizer effects of E1a in response to cisplatin in non-small cell lung carcinoma cells

    Science.gov (United States)

    Pascual-Serra, Raquel; García-Cano, Jesus; Garcia-Gil, Elena; De la Cruz-Morcillo, Miguel; Ortega-Muelas, Marta; Serrano-Oviedo, Leticia; Gutkind, J. Silvio; Sánchez-Prieto, Ricardo

    2015-01-01

    The adenoviral gene E1a is known to enhance the antitumor effect of cisplatin, one of the cornerstones of the current cancer chemotherapy. Here we study the molecular basis of E1a mediated sensitivity to cisplatin in an experimental model of Non-small cell lung cancer. Our data show how E1a blocks the induction of autophagy triggered by cisplatin and promotes the apoptotic response in resistant cells. Interestingly, at the molecular level, we present evidences showing how the phosphatase MKP1 is a major determinant of cisplatin sensitivity and its upregulation is strictly required for the induction of chemosensitivity mediated by E1a. Indeed, E1a is almost unable to promote sensitivity in H460, in which the high expression of MKP1 remains unaffected by E1a. However, in resistant cell as H1299, H23 or H661, which display low levels of MKP1, E1a expression promotes a dramatic increase in the amount of MKP1 correlating with cisplatin sensitivity. Furthermore, effective knock down of MKP1 in H1299 E1a expressing cells restores resistance to a similar extent than parental cells. In summary, the present work reinforce the critical role of MKP1 in the cellular response to cisplatin highlighting the importance of this phosphatase in future gene therapy approach based on E1a gene. PMID:26689986

  1. Enhanced chemosensitivity of p73α gene transferred into H1299 cell line of human lung adenocarcinoma

    Institute of Scientific and Technical Information of China (English)

    HE Yong; FAN Shi-zhi; Kalkunte S Srivenugopal; JIANG Yao-guang; QIN Chuan

    2004-01-01

    Objective: To study the effects of transferred wild type p73α gene on the sensitivity to the chemotherapeutic agents and the growth of p53-null H1299 cells of human lung adenocarcinoma. Methods: The pcDNA3-HA-p73α plasmid was transferred into the cultured p53-null H1299 cells of human lung adenocarcinoma with the mediation of Dosper liposome;The cells resistant to G418 were selected. The expression of p73α gene in the cells was examined with Western blot. MTT assay was used to analyze the response of the transfected cells to cis-dichlorodiamine platinum (cDDP) and adriamycin (ADM). The rate of drug-induced apoptosis of the transfected cells was determined with flow cytometry and DNA fragmentation assay. The changes of the biological behaviors were observed with colony formation assay. Results: The transfected H1299 cells of human lung adenocarcinoma over-expressed p73α protein stably. MTT assay showed that the IC50 values of cDDP and ADM were reduced by approximately 7 fold and 130 fold respectively in the transfected cells as compared with the untransfected ones. Lower concentration of the chemotherapeutic agents ( 1.25 μmol/L of cDDP and 0.05 μmol/L of ADM)could be employed to suppress markedly the growth of the transfected H1299 cells. The apoptotic rate induced by cDDP was increased from 10.1% to 38.4% ( P < 0.01 ) and that of ADM from 12.1% to 49.3 % ( P < 0.01 ). The clonogenecity after the administration of chemotherapeutic agents was significantly lower in the transfected H1299 cells than in the parental cells (P < 0.01). The sensitive enhancement ratios were 1.8 and 2.6 for cDDP and ADM respectively. Conclusion: The transfection of H1299 cells with wild type p73α gene results in an increase of the sensitivity of the cells to chemotherapeutic agents.

  2. AgentChess : An Agent Chess Approach

    OpenAIRE

    Fransson, Henric

    2003-01-01

    The game of chess has many times been discussed and used for test purpose by science departments of Artificial Intelligence (AI). Although the technique of agent and as well multi-agent systems is quite old, the use of these offspring of AI within chess is limited. This report describes the project performed applying the use of agents to a chess program. To measure the performance of the logic has tests between the developed program main parts been performed. Further tests against a tradition...

  3. Agents in domestic environments

    OpenAIRE

    van Moergestel, Leo; Langerak, Wouter; Meerstra, Glenn; Nieuwenburg, Niels van; Pape, Franc; Telgen, Daniël; Puik, Erik; meyer, john-jules

    2013-01-01

    Athor supplied : "This paper describes an agent-based architecture for domotics. This architecture is based on requirements about expandability and hardware independence. The heart of the system is a multi-agent system. This system is distributed over several platforms to open the possibility to tie the agents directly to the actuators, sensors and devices involved. This way a level of abstraction is created and all intelligence of the system as a whole is related to the agents involved. A pr...

  4. Culturally Aware Agent Communication

    DEFF Research Database (Denmark)

    Rehm, Matthias; Nakano, Yukiko; Koda, Tomoko;

    2012-01-01

    Agent based interaction in the form of Embodied Conversational Agents (ECAs) has matured over the last decade and agents have become more and more sophisticated in terms of their verbal and nonverbal behavior like facial expressions or gestures. Having such “natural” communication channels...

  5. Riot Control Agents

    Science.gov (United States)

    ... a person has been exposed to riot control agents. Long-term health effects of exposure to riot control agents Prolonged ... person is removed from exposure to riot control agents, long-term health effects are unlikely to occur. How you can ...

  6. Reasoning about emotional agents

    NARCIS (Netherlands)

    Meyer, J.-J.

    2008-01-01

    In this paper we discuss the role of emotions in artificial agent design, and the use of logic in reasoning about the emotional or affective states an agent can reside in. We do so by extending the KARO framework for reasoning about rational agents appropriately. In particular we formalize in this f

  7. Agents modeling agents in information economies

    Energy Technology Data Exchange (ETDEWEB)

    Vidal, J.M.; Durfee, E.H. [Univ. of Michigan, Ann Arbor, MI (United States)

    1996-12-31

    Our goal is to design and build agents that act intelligently when placed in an agent-based information economy, where agents buy and sell services (e.g. thesaurus, search, task planning services, etc.). The economy we are working in is the University of Michigan Digital Library (UMDL), a large scale multidisciplinary effort to build an infrastructure for the delivery of library services. In contrast with a typical economy, an information economy deals in goods and services that are often derived from unique sources (authors, analysts, etc.), so that many goods and services are not interchangeable. Also, the cost of replicating and transporting goods is usually negligible, and the quality of goods and services is difficult to measure objectively: even two sources with essentially the same information might appeal to different audiences. Thus, each agent has its own assessment of the quality of goods and services delivered.

  8. Arctigenin enhances chemosensitivity to cisplatin in human nonsmall lung cancer H460 cells through downregulation of survivin expression.

    Science.gov (United States)

    Wang, Huan-qin; Jin, Jian-jun; Wang, Jing

    2014-01-01

    Arctigenin, a dibenzylbutyrolactone lignan, enhances cisplatin-mediated cell apoptosis in cancer cells. Here, we sought to investigate the effects of arctigenin on cisplatin-treated non-small-cell lung cancer (NSCLC) H460 cells. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and annexin-V/propidium iodide staining were performed to analyze the proliferation and apoptosis of H460 cells. Arctigenin dose-dependently suppressed cell proliferation and potentiated cell apoptosis, coupled with increased cleavage of caspase-3 and poly(ADP-ribose) polymerase. Moreover, arctigenin sensitized H460 cells to cisplatin-induced proliferation inhibition and apoptosis. Arctigenin alone or in combination with cisplatin had a significantly lower amount of survivin. Ectopic expression of survivin decreased cell apoptosis induced by arctigenin (P arctigenin (P arctigenin has a therapeutic potential in combina-tion with chemotherapeutic agents for NSLC. PMID:24395429

  9. Selenium enrichment of broccoli sprout extract increases chemosensitivity and apoptosis of LNCaP prostate cancer cells

    Directory of Open Access Journals (Sweden)

    Suzuki Kazuhiro

    2009-11-01

    Full Text Available Abstract Background Broccoli is a Brassica vegetable that is believed to possess chemopreventive properties. Selenium also shows promise as an anticancer agent. Thus, selenium enrichment of broccoli has the potential to enhance the anticancer properties of broccoli sprouts. Method Selenium-enriched broccoli sprouts were prepared using a sodium selenite solution. Their anticancer properties were evaluated in human prostate cancer cell lines and compared with those of a control broccoli sprout extract. Results Selenium-enriched broccoli sprouts were superior to normal broccoli sprouts in inhibiting cell proliferation, decreasing prostate-specific antigen secretion, and inducing apoptosis of prostate cancer cells. Furthermore, selenium-enriched broccoli sprouts but, not normal broccoli sprouts, induced a downregulation of the survival Akt/mTOR pathway. Conclusion Our results suggest that selenium-enriched broccoli sprouts could potentially be used as an alternative selenium source for prostate cancer prevention and therapy.

  10. The effect of adenovirus expressing wild-type p53 on 5-fiuorouracil chemosensitivity is related to p53 status in pancreatic cancer cell lines

    Institute of Scientific and Technical Information of China (English)

    Sven Eisold; Michael Linnebacher; Eduard Ryschich; Dalibor Antolovic; Ulf Hinz; Ernst Klar; Jan Schmidt

    2004-01-01

    AIM: There are conflicting data about p53 function on cellular sensitivity to the cytotoxic action of 5-fluorouracil (5-FU).Therefore the objective of this study was to determine the combined effects of adenovirus-mediated wild-type (wt) p53gene transfer and 5-FU chemotherapy on pancreatic cancer cells with different p53 gene status.METHODS: Human pancreatic cancer cell lines Capan-1p53mut,Capan-2p53wt, FAMPACp53mut, PANC1p53mut, and rat pancreatic cancer cell lines ASp53wt and DSL6Ap53null were used for in vitro studies. Following infection with different ratios of Adp53-particles (MOI) in combination with 5-FU, proliferation of tumor cells and apoptosis were quantified by cell proliferation assay (WST-1) and FACS (PI-staining). In addition, DSL6A syngeneic pancreatic tumor cells were inoculated subcutaneously in to Lewis rats for in vivo studies.Tumor size, apoptosis (TUNEL) and survival were determined.RESULTS: Ad-p53 gene transfer combined with 5-FU significantly inhibited tumor cell proliferation and substantially enhanced apoptosis in all four cell lines with an alteration in the p53 gene compared to those two cell lines containing wt-p53. In vivo experiments showed the most effective tumor regression in animals treated with Ad-p53 plus 5-FU. Both in vitro and in vivo analyses revealed that a sublethal dose of Ad-p53 augmented the apoptotic response induced by 5-FU.CONCLUSION: Our results suggest that Ad-p53 may synergistically enhance 5-FU-chemosensitivity most strikingly in pancreatic cancer cells lacking p53 function. These findings illustrate that the anticancer efficacy of this combination treatment is dependent on the p53 gene status of the target tumor cells.

  11. Inhibition of Bcl-2 expression by a novel tumor-specific RNA interference system increases chemosensitivity to 5-fluorouracil in Hela cells

    Institute of Scientific and Technical Information of China (English)

    Sheng-lin HUANG; Yi WU; Hai YU; Ping ZHANG; Xing-qian ZHANG; Lei YING; Han-fang ZHAO

    2006-01-01

    Aim: RNA interference (RNAi) has been proposed as a potential treatment for cancer, but the lack of cellular targets limits its use in cancer gene therapy. No current technology has achieved direct tumor-specific gene silencing using RNAi.In the present study we attempt to develop a tumor-specific RNAi system using the human telomerase reverse transcriptase (hTERT) promoter; furthermore, we analyzed its inhibitive effect on Bcl-2 expression. Methods: The vectors containing a small hairpin RNA (shRNA) to target exogenous reporters [firefly luciferase and enhanced green fluorescent protein (EGFP)] and endogenous gene (Bcl-2)were constructed. Luciferase expression was determined by dual luciferase assay.Reverse transcription-polymerase chain reaction (RT-PCR), fluorescence microscopy and fluorescence-activated cell sorting (FACS) were used to measure EGFP expression. Inhibition of Bcl-2 was evaluated by RT-PCR and Western blotting.Cell proliferation and viability were measured by using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay. FACS was used to analyze the cell cycle distribution profile. Results: We showed that with the hTERT promoter directly driving shRNA transcription, expression of the exogenous reporters (LUC and EGFP) in tumor cells, but not normal cells, was specifically inhibited in vitro. The hTERT promoter-driven shRNA also depressed the expression of Bcl-2. Inhibition of Bcl-2 did not affect cell proliferation, but increased the chemosensitivity of HeLa cells to 5-fluorouracil. Conclusion: The present study describes an efficient RNAi system for gene silencing that is specific to tumor cells using the hTERT promoter. Suppression of Bcl-2 by using this system sensitized HeLa cells to 5-fluorouracil. This system may be useful for RNAi therapy.

  12. Inhibition of MerTK increases chemosensitivity and decreases oncogenic potential in T-cell acute lymphoblastic leukemia.

    Science.gov (United States)

    Brandao, L N; Winges, A; Christoph, S; Sather, S; Migdall-Wilson, J; Schlegel, J; McGranahan, A; Gao, D; Liang, X; Deryckere, D; Graham, D K

    2013-01-01

    Pediatric leukemia survival rates have improved dramatically over the past decades. However, current treatment protocols are still largely ineffective in cases of relapsed leukemia and are associated with a significant rate of chronic health conditions. Thus, there is a continued need for new therapeutic options. Here, we show that mer receptor tyrosine kinase (MerTK) was abnormally expressed in approximately one half of pediatric T-cell leukemia patient samples and T-cell acute lymphoblastic leukemia (T-ALL) cell lines. Stimulation of MerTK by the ligand Gas6 led to activation of the prosurvival proteins Erk 1/2 and Stat5, and MerTK-dependent activation of the STAT pathway in leukemia represents a novel finding. Furthermore, inhibition of MerTK expression increased the sensitivity of T-ALL cells to treatment with chemotherapeutic agents and decreased the oncogenic potential of the Jurkat T-ALL cell line in a methylcellulose colony-forming assay. Lastly, inhibition of MerTK expression significantly increased median survival in a xenograft mouse model of leukemia (30.5 days vs 60 days, P<0.0001). These results suggest that inhibition of MerTK is a promising therapeutic strategy for the treatment of leukemia and may allow for dose reduction of currently used chemotherapeutics resulting in decreased rates of therapy-associated toxicities. PMID:23353780

  13. Inhibition of MerTK increases chemosensitivity and decreases oncogenic potential in T-cell acute lymphoblastic leukemia

    International Nuclear Information System (INIS)

    Pediatric leukemia survival rates have improved dramatically over the past decades. However, current treatment protocols are still largely ineffective in cases of relapsed leukemia and are associated with a significant rate of chronic health conditions. Thus, there is a continued need for new therapeutic options. Here, we show that mer receptor tyrosine kinase (MerTK) was abnormally expressed in approximately one half of pediatric T-cell leukemia patient samples and T-cell acute lymphoblastic leukemia (T-ALL) cell lines. Stimulation of MerTK by the ligand Gas6 led to activation of the prosurvival proteins Erk 1/2 and Stat5, and MerTK-dependent activation of the STAT pathway in leukemia represents a novel finding. Furthermore, inhibition of MerTK expression increased the sensitivity of T-ALL cells to treatment with chemotherapeutic agents and decreased the oncogenic potential of the Jurkat T-ALL cell line in a methylcellulose colony-forming assay. Lastly, inhibition of MerTK expression significantly increased median survival in a xenograft mouse model of leukemia (30.5 days vs 60 days, P<0.0001). These results suggest that inhibition of MerTK is a promising therapeutic strategy for the treatment of leukemia and may allow for dose reduction of currently used chemotherapeutics resulting in decreased rates of therapy-associated toxicities

  14. Bioimpedance microelectronics in a 24-microwell plate with metabolic-sensors for testing chemosensitivity of tumor cells and tissues

    Science.gov (United States)

    Schwarzenberger, T.; Demmel, F.; Becker, B.; Zottmann, M.; Wolf, P.; Kleinhans, R.; Brischwein, M.; Otto, A.; Wolf, B.

    2010-04-01

    Living cells react to external influences such as pharmacological agents in an intricate manner due to their complex internal signal processing. Cell reactions are an impact on vitality, cell-cell or cell-matrix interaction and morphological changes. A number of published techniques on impedance spectroscopy (IS) of adherent cells with planar electrodes address these changes. However, IS can merely serve as an indicator of cellular events rather than provide detailed information on a specific cell process. Thus our approach is a 24-microwell sensor-plate with impedance-electrodes in parallel to pH- and O2-sensors, capable of being integrated into a fully automated screening system. For the purpose of IS, high precision impedance-electronics have been developed based on integrated circuits and validated against a Solartron 1260 impedance analyzer. IS data is correlated to the metabolic-sensors and additionally compared with cell images shot by an inverse optical microscope which is also part of the screening system. Proof of principle is demonstrated by experimental growth monitoring of a MCF-7 culture and cellular response to chemotherapeutics. Furthermore, the potential to monitor living tissue probes is presented for the first time.

  15. Chemical crowd control agents.

    Science.gov (United States)

    Menezes, Ritesh G; Hussain, Syed Ather; Rameez, Mansoor Ali Merchant; Kharoshah, Magdy A; Madadin, Mohammed; Anwar, Naureen; Senthilkumaran, Subramanian

    2016-03-01

    Chemical crowd control agents are also referred to as riot control agents and are mainly used by civil authorities and government agencies to curtail civil disobedience gatherings or processions by large crowds. Common riot control agents used to disperse large numbers of individuals into smaller, less destructive, and more easily controllable numbers include chloroacetophenone, chlorobenzylidenemalononitrile, dibenzoxazepine, diphenylaminearsine, and oleoresin capsicum. In this paper, we discuss the emergency medical care needed by sufferers of acute chemical agent contamination and raise important issues concerning toxicology, safety and health. PMID:26658556

  16. Decontamination Data - Blister Agents

    Data.gov (United States)

    U.S. Environmental Protection Agency — Decontamination efficacy data for blister agents on various building materials using various decontamination solutions This dataset is associated with the following...

  17. CTBT PrepCom work in Namibia

    International Nuclear Information System (INIS)

    The history, location and facilities of Namibia's Tsumeb Geophysical Research Station are briefly described. The station's seismic and infrasound activities together with its IMS and CTBTO membership are mentioned. Manpower, training and budgetary constriants are noted

  18. Infrasound workshop for CTBT monitoring: Proceedings

    International Nuclear Information System (INIS)

    It is expected that the establishment of new infrasound stations in the global IMS network by the Provisional Technical Secretariat of the CTBTO in Vienna will commence in the middle of 1998. Thus, decisions on the final operational design for IMS infrasound stations will have to be made within the next 12 months. Though many of the basic design problems have been resolved, it is clear that further work needs to be carried out during the coming year to ensure that IMS infrasound stations will operate with maximum capability in accord with the specifications determined during the May 1997 PrepCom Meeting. Some of the papers presented at the Workshop suggest that it may be difficult to design a four-element infrasound array station that will reliably detect and locate infrasound signals at all frequencies in the specified range from 0.02 to 4.0 Hz in all noise environments. Hence, if the basic design of an infrasound array is restricted to four array elements, the final optimized design may be suited only to the detection and location of signals in a more limited pass-band. Several participants have also noted that the reliable discrimination of infrasound signals could be quite difficult if the detection system leads to signal distortion. Thus, it has been emphasized that the detection system should not, if possible, compromise signal fidelity. This report contains the workshop agenda, a list of participants, and abstracts and viewgraphs from each presentation

  19. The IMS radionuclide network of the CTBT

    International Nuclear Information System (INIS)

    The Comprehensive Nuclear Test-Ban Treaty calls for the establishment of a world-wide network of monitoring stations (IMS, International Monitoring System). In total 321 monitoring stations will be installed: 50 primary seismic, 120 auxiliary seismic, 11 hydroacoustic, 60 infrasound and 80 radionuclide. The 80 radionuclide stations collect particulate from the air and measure its radioactivity. Among these radionuclide stations, 40 of them will also have the capability of measuring the concentration in the air of the noble gas Xenon. The particulate stations will have a cycle of 1 day collection, 1 day decay time and 1 day acquisition time whereas the noble gas stations will have 1 day of collection and 1 day of acquisition time. Equipment for particulate station consists of a high volume air sampler (flow rate ≥ 500 m-3 h-1 at standard pressure and temperature) and a HPGe detector system with a relative efficiency of at least 40 %. Stations can be manually or automatically operated depending on the choice of the host country. The technical specification of the equipment to be used, the distribution and the number of stations around the world were chosen in such a way to be able to detect nuclear explosions according to the following criterion: 90 % detection probability within approximately 14 days for a 1 kt nuclear explosion in the atmosphere or from venting by an underground or underwater detonation. All data collected are converted in a standard format and sent directly to Vienna where they are analysed. Most of the stations will send data through a very reliable satellite link. In fact it is required that particulate stations will send spectral data within 72 hours of collection start, within 48 hours for noble gas stations. In addition every station should reach 95 % of data availability; in particular it is required that the maximum consecutive down time is 7 days and a maximum of 15 days annually. In case of suspicious events detected by the stations, atmospheric transport models will be applied in order to localise the source as accurately as possible. After the treaty has entered into force, when a nuclear test is suspected, the state parties can take the decision to perform an on-site inspection at the location where this test is supposed having taken place. Currently about 11 stations are fully installed and it is planned to have additionally about 20 stations installed by the end of the year 2000. (author)

  20. Infrasound workshop for CTBT monitoring: Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    Christie, D.; Whitaker, R.

    1998-11-01

    It is expected that the establishment of new infrasound stations in the global IMS network by the Provisional Technical Secretariat of the CTBTO in Vienna will commence in the middle of 1998. Thus, decisions on the final operational design for IMS infrasound stations will have to be made within the next 12 months. Though many of the basic design problems have been resolved, it is clear that further work needs to be carried out during the coming year to ensure that IMS infrasound stations will operate with maximum capability in accord with the specifications determined during the May 1997 PrepCom Meeting. Some of the papers presented at the Workshop suggest that it may be difficult to design a four-element infrasound array station that will reliably detect and locate infrasound signals at all frequencies in the specified range from 0.02 to 4.0 Hz in all noise environments. Hence, if the basic design of an infrasound array is restricted to four array elements, the final optimized design may be suited only to the detection and location of signals in a more limited pass-band. Several participants have also noted that the reliable discrimination of infrasound signals could be quite difficult if the detection system leads to signal distortion. Thus, it has been emphasized that the detection system should not, if possible, compromise signal fidelity. This report contains the workshop agenda, a list of participants, and abstracts and viewgraphs from each presentation.

  1. CTBT and the international technical cooperation

    International Nuclear Information System (INIS)

    Having in mind the basic aim of the CTBTO this presentation covers the fields of international co-operation as one of the most important and the cooperation of China and some International research and development institutions concerning the related subjects. One of the most important among international organizations being the IAEA, detailed list of general circumstances in the Chinese cooperation with IAEA is presented. It covers nuclear power plants construction and operation, safety of nuclear facilities, nuclear fuel cycle, radiation protection and waste management, industrial application, agricultural application, human health, fundamental research and information dissemination

  2. 3'-Phosphoadenosine 5'-phosphosulfate synthase 1 (PAPSS1) knockdown sensitizes non-small cell lung cancer cells to DNA damaging agents.

    Science.gov (United States)

    Leung, Ada W Y; Dragowska, Wieslawa H; Ricaurte, Daniel; Kwok, Brian; Mathew, Veena; Roosendaal, Jeroen; Ahluwalia, Amith; Warburton, Corinna; Laskin, Janessa J; Stirling, Peter C; Qadir, Mohammed A; Bally, Marcel B

    2015-07-10

    Standard treatment for advanced non-small cell lung cancer (NSCLC) with no known driver mutation is platinum-based chemotherapy, which has a response rate of only 30-33%. Through an siRNA screen, 3'-phosphoadenosine 5'-phosphosulfate (PAPS) synthase 1 (PAPSS1), an enzyme that synthesizes the biologically active form of sulfate PAPS, was identified as a novel platinum-sensitizing target in NSCLC cells. PAPSS1 knockdown in combination with low-dose (IC10) cisplatin reduces clonogenicity of NSCLC cells by 98.7% (p < 0.001), increases DNA damage, and induces G1/S phase cell cycle arrest and apoptosis. PAPSS1 silencing also sensitized NSCLC cells to other DNA crosslinking agents, radiation, and topoisomerase I inhibitors, but not topoisomerase II inhibitors. Chemo-sensitization was not observed in normal epithelial cells. Knocking out the PAPSS1 homolog did not sensitize yeast to cisplatin, suggesting that sulfate bioavailability for amino acid synthesis is not the cause of sensitization to DNA damaging agents. Rather, sensitization may be due to sulfation reactions involved in blocking the action of DNA damaging agents, facilitating DNA repair, promoting cancer cell survival under therapeutic stress or reducing the bioavailability of DNA damaging agents. Our study demonstrates for the first time that PAPSS1 could be targeted to improve the activity of multiple anticancer agents used to treat NSCLC. PMID:26220590

  3. 3′-Phosphoadenosine 5′-phosphosulfate synthase 1 (PAPSS1) knockdown sensitizes non-small cell lung cancer cells to DNA damaging agents

    Science.gov (United States)

    Leung, Ada W. Y.; Dragowska, Wieslawa H.; Ricaurte, Daniel; Kwok, Brian; Mathew, Veena; Roosendaal, Jeroen; Ahluwalia, Amith; Warburton, Corinna; Laskin, Janessa J.; Stirling, Peter C.; Qadir, Mohammed A.; Bally, Marcel B.

    2015-01-01

    Standard treatment for advanced non-small cell lung cancer (NSCLC) with no known driver mutation is platinum-based chemotherapy, which has a response rate of only 30–33%. Through an siRNA screen, 3′-phosphoadenosine 5′-phosphosulfate (PAPS) synthase 1 (PAPSS1), an enzyme that synthesizes the biologically active form of sulfate PAPS, was identified as a novel platinum-sensitizing target in NSCLC cells. PAPSS1 knockdown in combination with low-dose (IC10) cisplatin reduces clonogenicity of NSCLC cells by 98.7% (p < 0.001), increases DNA damage, and induces G1/S phase cell cycle arrest and apoptosis. PAPSS1 silencing also sensitized NSCLC cells to other DNA crosslinking agents, radiation, and topoisomerase I inhibitors, but not topoisomerase II inhibitors. Chemo-sensitization was not observed in normal epithelial cells. Knocking out the PAPSS1 homolog did not sensitize yeast to cisplatin, suggesting that sulfate bioavailability for amino acid synthesis is not the cause of sensitization to DNA damaging agents. Rather, sensitization may be due to sulfation reactions involved in blocking the action of DNA damaging agents, facilitating DNA repair, promoting cancer cell survival under therapeutic stress or reducing the bioavailability of DNA damaging agents. Our study demonstrates for the first time that PAPSS1 could be targeted to improve the activity of multiple anticancer agents used to treat NSCLC. PMID:26220590

  4. 流式细胞术应用于抗肿瘤药物敏感性实验的可行性研究%The feasibility of antitumor drugs chemosensitivity testing by flow Cytometry

    Institute of Scientific and Technical Information of China (English)

    Jing Yao; Jianhong Wu; Daxing Xie; Xiaolan Li; Deding Tao; Junbo Hu; Jianping Gong

    2007-01-01

    Objective:To investigate the feasibility of chemosensitivity testing of antitumor drugs by flow cytometry in clinical applications so as to provide experimental and theoretical basis for the establishment of a novel antitumor drugs sensitivity testing and the screening of particular antitumor drugs.Methods:Detect the apoptosis rate of 12 cases of Molt-4 cell line.57 cases of fresh clinical gastrointestinal tumor cells by Sub-G1 and Annexin V assay of flow cytometry under the effects of antitumor drugs at different times and the outcomes were compared with the ones of the MTT(3-(4,5-dimethylthiazolyl-2)-2,5-diphenyltetrazolium bromide)assay.Results:The lethality of drugs on Molt-4 cell clinica gastrointestinal tumor cells had a positive correlation with the acting time of antidrugs by employing Annexin V.Sub-G1 and MTT assay.Drug-incurring maximum lethality of Annexin V assay was higher than MTT colorimetric assay.that of Sub-G1 was lower than MTT assay.the virtual times of Annexin V and Sub-G1 assay were obviously earlier than that of MTT colorimetric assay.Conclusion:Annexin V and Sub-G1 assay of flow cytometry can be taken as potent protocols testing anti-tumor drug chemosensitivity.Annexin V assay is featured by more sensitive,concise,reliable compared with the classical chemosensilivity testing assay Of MTT colorimetric assay and it possesses clinical applied value.

  5. Agent Development Toolkits

    CERN Document Server

    Singh, Aarti; Sharma, A K

    2011-01-01

    Development of agents as well as their wide usage requires good underlying infrastructure. Literature indicates scarcity of agent development tools in initial years of research which limited the exploitation of this beneficial technology. However, today a wide variety of tools are available, for developing robust infrastructure. This technical note provides a deep overview of such tools and contrasts features provided by them.

  6. Radiographic scintiscanning agent

    International Nuclear Information System (INIS)

    A new technetium-based scintiscanning agent has been prepared comprising a water soluble sup(99m)Tc-methanehydroxydiphosphonate in combination with a reducing agent selected from stannous, ferrous, chromous and titanous salts. As an additional stabilizer salts and esters of gentisic or ascorbic acids have been used. (E.G.)

  7. Asimovian Adaptive Agents

    CERN Document Server

    Gordon, D F

    2011-01-01

    The goal of this research is to develop agents that are adaptive and predictable and timely. At first blush, these three requirements seem contradictory. For example, adaptation risks introducing undesirable side effects, thereby making agents' behavior less predictable. Furthermore, although formal verification can assist in ensuring behavioral predictability, it is known to be time-consuming. Our solution to the challenge of satisfying all three requirements is the following. Agents have finite-state automaton plans, which are adapted online via evolutionary learning (perturbation) operators. To ensure that critical behavioral constraints are always satisfied, agents' plans are first formally verified. They are then reverified after every adaptation. If reverification concludes that constraints are violated, the plans are repaired. The main objective of this paper is to improve the efficiency of reverification after learning, so that agents have a sufficiently rapid response time. We present two solutions: ...

  8. How do agents represent?

    Science.gov (United States)

    Ryan, Alex

    Representation is inherent to the concept of an agent, but its importance in complex systems has not yet been widely recognised. In this paper I introduce Peirce's theory of signs, which facilitates a definition of representation in general. In summary, representation means that for some agent, a model is used to stand in for another entity in a way that shapes the behaviour of the agent with respect to that entity. Representation in general is then related to the theories of representation that have developed within different disciplines. I compare theories of representation from metaphysics, military theory and systems theory. Additional complications arise in explaining the special case of mental representations, which is the focus of cognitive science. I consider the dominant theory of cognition — that the brain is a representational device — as well as the sceptical anti-representational response. Finally, I argue that representation distinguishes agents from non-representational objects: agents are objects capable of representation.

  9. Hyperthermia and chemotherapy agent

    International Nuclear Information System (INIS)

    The use of chemotherapeutic agents for the treatment of cancer dates back to the late 19th century, but the modern era of chemotherapy drugs was ushered in during the 1940's with the development of the polyfunctional alkylating agent. Since then, numerous classes of drugs have evolved and the combined use of antineoplastic agents with other treatment modalities such as radiation or heat, remains a large relatively unexplored area. This approach, combining local hyperthermia with chemotherapy agents affords a measure of targeting and selective toxicity not previously available for drugs. In this paper, the effects of adriamycin, bleomycin and cis-platinum are examined. The adjuvant use of heat may also reverse the resistance of hypoxic cells noted for some chemotherapy agents

  10. miR-29b, miR-205 and miR-221 enhance chemosensitivity to gemcitabine in HuH28 human cholangiocarcinoma cells.

    Directory of Open Access Journals (Sweden)

    Kinya Okamoto

    Full Text Available BACKGROUND AND AIMS: Cholangiocarcinoma (CCA is highly resistant to chemotherapy, including gemcitabine (Gem treatment. MicroRNAs (miRNAs are endogenous, non-coding, short RNAs that can regulate multiple genes expression. Some miRNAs play important roles in the chemosensitivity of tumors. Here, we examined the relationship between miRNA expression and the sensitivity of CCA cells to Gem. METHODS: Microarray analysis was used to determine the miRNA expression profiles of two CCA cell lines, HuH28 and HuCCT1. To determine the effect of candidate miRNAs on Gem sensitivity, expression of each candidate miRNA was modified via either transfection of a miRNA mimic or transfection of an anti-oligonucleotide. Ontology-based programs were used to identify potential target genes of candidate miRNAs that were confirmed to affect the Gem sensitivity of CCA cells. RESULTS: HuCCT1 cells were more sensitive to Gem than were HuH28 cells, and 18 miRNAs were differentially expressed whose ratios over ± 2log2 between HuH28 and HuCCT1. Among these 18 miRNAs, ectopic overexpression of each of three downregulated miRNAs in HuH28 (miR-29b, miR-205, miR-221 restored Gem sensitivity to HuH28. Suppression of one upregulated miRNA in HuH28, miR-125a-5p, inhibited HuH28 cell proliferation independently to Gem treatment. Selective siRNA-mediated downregulation of either of two software-predicted targets, PIK3R1 (target of miR-29b and miR-221 or MMP-2 (target of miR-29b, also conferred Gem sensitivity to HuH28. CONCLUSIONS: miRNA expression profiling was used to identify key miRNAs that regulate Gem sensitivity in CCA cells, and software that predicts miRNA targets was used to identify promising target genes for anti-tumor therapies.

  11. A meta-analytic review of ERCC1/MDR1 polymorphism and chemosensitivity to platinum in patients with advanced non-small cell lung cancer

    Institute of Scientific and Technical Information of China (English)

    WEI Hai-bo; HU Jing; SHANG Li-hua; ZHANG Yun-yan; LU Fei-fei; WEI Min; YU Yan

    2012-01-01

    Background Platinum-based regimens are used as standard first-line chemotherapy in non-small cell lung cancer (NSCLC) patients.To study if pharmacogenetic approach may allow a tailored selection of platinum chemotherapy for advanced NSCLC,we performed a meta-analysis to compare chemosensitivity to platinum with different ERCC1 C118T/MDR1 C3435T single-nucleotide polymorphism (SNP).Methods Relevant studies were identified by searching the PubMed,Embase,Cochrane,OVID,Springer,EBSCO and CNKI databases.Inclusion criteria were patients with advanced NSCLC who received platinum-based chemotherapy,an evaluated polymorphism of ERCC/MDR1 and overall response rate.We excluded duplicate publications,letters and review articles.The RevMan 4.2 and STATA 11 package were used to do comprehensive quantitative assessment.Results A total of 11 studies were included in this meta-analysis.For studies evaluating ERCC1 C118T,test for heterogeneity was done (x2=13.41,P=0.1),and the odds ratio (OR) for the wild-type C/C genotype versus the heterozygous C/T and T/T genotypes was 1.50 (95% CI 1.09-2.06,P=-0.01).In four studies evaluating MDR1 polymorphism,test for heterogeneity was also done (x2=3.22,P=0.36),and the OR for the wild-type C/C genotype versus the heterozygous C/T and T/T genotypes was 2.30 (95% CI 1.44-3.68,P=0.0005).Conclusions The results indicated that platinum-based chemotherapy sensitivity was significantly associated with polymorphism of ERCC1 C118T and MDR1 C3435T SNP.In further perspective studies,the ERCC1/MDR1 SNPs might serve as simple and less invasive biomarkers for personalized chemotherapy with platinum-based anticancer drugs.

  12. Suppression of SPIN1-mediated PI3K-Akt pathway by miR-489 increases chemosensitivity in breast cancer.

    Science.gov (United States)

    Chen, Xu; Wang, Ya-Wen; Xing, Ai-Yan; Xiang, Shuai; Shi, Duan-Bo; Liu, Lei; Li, Yan-Xiang; Gao, Peng

    2016-08-01

    Drug resistance is one of the major obstacles for improving the prognosis of breast cancer patients. Increasing evidence has linked the association of aberrantly expressed microRNAs (miRNAs) with tumour development and progression as well as chemoresistance. Despite recent advances, there is still little known about the potential role and mechanism of miRNAs in breast cancer chemoresistance. Here we describe that 16 miRNAs were found to be significantly down-regulated and 11 up-regulated in drug-resistant breast cancer tissues compared with drug-sensitive tissues, using a miRNA microarray. The results also showed miR-489 to be one of the most down-regulated miRNAs in drug-resistant tissues and cell lines, as confirmed by miRNA microarray screening and real-time quantitative PCR. A decrease in miR-489 expression was associated with chemoresistance as well as lymph node metastasis, increased tumour size, advanced pTNM stage and poor prognosis in breast cancer. Functional analysis revealed that miR-489 increased breast cancer chemosensitivity and inhibited cell proliferation, migration and invasion, both in vitro and in vivo. Furthermore, SPIN1, VAV3, BCL2 and AKT3 were found to be direct targets of miR-489. SPIN1 was significantly elevated in drug-resistant and metastatic breast cancer tissues and inversely correlated with miR-489 expression. High expression of SPIN1 was associated with higher histological grade, lymph node metastasis, advanced pTNM stage and positive progesterone receptor (PR) status. Increased SPIN1 expression enhanced cell migration and invasion, inhibited apoptosis and partially antagonized the effects of miR-489 in breast cancer. PIK3CA, AKT, CREB1 and BCL2 in the PI3K-Akt signalling pathway, demonstrated to be elevated in drug-resistant breast cancer tissues, were identified as downstream effectors of SPIN1. It was further found that either inhibition of SPIN1 or overexpression of miR-489 suppressed the PI3K-Akt signalling pathway. These data

  13. Users, Bystanders and Agents

    DEFF Research Database (Denmark)

    Krummheuer, Antonia Lina

    2015-01-01

    Human-agent interaction (HAI), especially in the field of embodied conversational agents (ECA), is mainly construed as dyadic communication between a human user and a virtual agent. This is despite the fact that many application scenarios for future ECAs involve the presence of others. This paper...... the construction of the agent’s identity, and (3) how HAI, as a mediated interaction, is framed by an asymmetric participation framework. The paper concludes by suggesting various participation roles, which may inform development of ECAs....

  14. Agent-Based Optimization

    CERN Document Server

    Jędrzejowicz, Piotr; Kacprzyk, Janusz

    2013-01-01

    This volume presents a collection of original research works by leading specialists focusing on novel and promising approaches in which the multi-agent system paradigm is used to support, enhance or replace traditional approaches to solving difficult optimization problems. The editors have invited several well-known specialists to present their solutions, tools, and models falling under the common denominator of the agent-based optimization. The book consists of eight chapters covering examples of application of the multi-agent paradigm and respective customized tools to solve  difficult optimization problems arising in different areas such as machine learning, scheduling, transportation and, more generally, distributed and cooperative problem solving.

  15. Agent Standards Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The innovation of the work herein proposed is the development of standards for software autonomous agents. These standards are essential to achieve software...

  16. Programming Service Oriented Agents

    OpenAIRE

    Hirsch, Benjamin; Konnerth, Thomas; Burkhardt, Michael; Albayrak, Sahin

    2010-01-01

    This paper introduces a programming language for service-oriented agents. JADL++ combines the ease of use of scripting-languages with a state-of-the-art service oriented approach which allows the seamless integration of web-services. Furthermore, the language includes OWL-based ontologies for semantic descriptions of data and services, thus allowing agents to make intelligent decisions about service calls.

  17. Adrenal imaging agents

    International Nuclear Information System (INIS)

    The goals of this proposal are the development of selenium-containing analogs of the aromatic amino acids as imaging agents for the pancreas and of the adrenal cortex enzyme inhibitors as imaging agents for adrenal pathology. The objects for this year include (a) the synthesis of methylseleno derivatives of phenylalanine and tryptophan, and (b) the preparation and evaluation of radiolabeled iodobenzoyl derivatives of the selenazole and thiazole analogs of metyrapone and SU-9055

  18. Agent amplified communication

    Energy Technology Data Exchange (ETDEWEB)

    Kautz, H.; Selman, B.; Milewski, A. [AT& T Laboratories, Murray Hill, NJ (United States)

    1996-12-31

    We propose an agent-based framework for assisting and simplifying person-to-person communication for information gathering tasks. As an example, we focus on locating experts for any specified topic. In our approach, the informal person-to-person networks that exist within an organization are used to {open_quotes}referral chain{close_quotes} requests for expertise. User-agents help automate this process. The agents generate referrals by analyzing records of e-mail communication patterns. Simulation results show that the higher responsiveness of an agent-based system can be effectively traded for the higher accuracy of a completely manual approach. Furthermore, preliminary experience with a group of users on a prototype system has shown that useful automatic referrals can be found in practice. Our experience with actual users has also shown that privacy concerns are central to the successful deployment of personal agents: an advanced agent-based system will therefore need to reason about issues involving trust and authority.

  19. Agent Oriented Programming进展%Advances in Agent Oriented Programming

    Institute of Scientific and Technical Information of China (English)

    王一川; 石纯一

    2002-01-01

    Agent-oriented programming (AOP) is a framework to develop agents, and it aims to link the gap betweentheory and practical in agent research. The core of an AOP framework is its language and semantics. In this paper,we propose the necessary properties which agents should have, and then give a summary and analysis about differentAOP languages based on these properties.

  20. Drugs reverting multidrug resistance (chemosensitizers)

    Energy Technology Data Exchange (ETDEWEB)

    Gualtieri, F. [Florence Univ. (Italy). Dip. di Scienze Farmaceutiche

    1996-12-01

    Drug resistance is a phenomenon that frequently impairs proper treatment of cancer. Multidrug resistance (MDR) is a particular case of acquired drug resistance, resulting from overexpression of a protein (P-170) that functions as a pump, clearing cells from the chemotherapic. The P-170 protein functions can be inhibited by a variety of lipophilic drugs containing a hydrophilic nitrogen, protonated at physiological pH. A considerable effort is underway to identify new drugs able to reverse MDR. Few of these molecules are already undergoing clinical trials.

  1. Agents unleashed a public domain look at agent technology

    CERN Document Server

    Wayner, Peter

    1995-01-01

    Agents Unleashed: A Public Domain Look at Agent Technology covers details of building a secure agent realm. The book discusses the technology for creating seamlessly integrated networks that allow programs to move from machine to machine without leaving a trail of havoc; as well as the technical details of how an agent will move through the network, prove its identity, and execute its code without endangering the host. The text also describes the organization of the host's work processing an agent; error messages, bad agent expulsion, and errors in XLISP-agents; and the simulators of errors, f

  2. El agente encubierto

    OpenAIRE

    Anaya Marcos, María del Carmen

    2015-01-01

    [ES] El trabajo versa sobre la figura del agente encubierto. Debemos enmarcar tal medida de investigación dentro del ámbito de la criminalidad organizada. Actualmente, estamos asistiendo a una proliferación de la delincuencia organizada. La sociedad ha evolucionado, y con ella la delincuencia. Fruto de tal evolución fue necesario incluir en nuestra Ley de Enjuiciamiento Criminal medidas extraordinarias de investigación, y una de ellas es el agente encubierto. Se trata de una medida muy polémi...

  3. The PLS agent : agent behavior validation by partial least squares

    OpenAIRE

    Lorscheid, Iris; Meyer, Matthias; Pakur, Sandra; Ringle, Christian

    2014-01-01

    Agent-based modeling is widely applied in the social sciences. However, the validation of agent behavior is challenging and identified as one of the shortcomings in the field. Methods are required to establish empirical links and support the implementation of valid agent models. This paper contributes to this, by introducing the PLS agent concept. This approach shows a way to transfer results about causalities and decision criteria from empirical surveys into an agent-based decision model, th...

  4. Trading Agents for Roaming Users

    OpenAIRE

    Boman, Magnus; Bylund, Markus; Espinoza, Fredrik; Danielson, Mats; Lyback, David

    2002-01-01

    Some roaming users need services to manipulate autonomous processes. Trading agents running on agent trade servers are used as a case in point. We present a solution that provides the agent owners with means to upkeeping their desktop environment, and maintaining their agent trade server processes, via a briefcase service.

  5. Software Agent Techniques in Design

    DEFF Research Database (Denmark)

    Hartvig, Susanne C

    1998-01-01

    This paper briefly presents studies of software agent techniques and outline aspects of these which can be applied in design agents in integrated civil engineering design environments.......This paper briefly presents studies of software agent techniques and outline aspects of these which can be applied in design agents in integrated civil engineering design environments....

  6. 13 CFR 107.1620 - Functions of agents, including Central Registration Agent, Selling Agent and Fiscal Agent.

    Science.gov (United States)

    2010-01-01

    ... 13 Business Credit and Assistance 1 2010-01-01 2010-01-01 false Functions of agents, including Central Registration Agent, Selling Agent and Fiscal Agent. 107.1620 Section 107.1620 Business Credit and Assistance SMALL BUSINESS ADMINISTRATION SMALL BUSINESS INVESTMENT COMPANIES SBA Financial Assistance...

  7. Programming multi-agent systems

    NARCIS (Netherlands)

    Dastani, Mehdi

    2015-01-01

    With the significant advances in the area of autonomous agents and multi-agent systems in the last decade, promising technologies for the development and engineering of multi-agent systems have emerged. The result is a variety of agent-oriented programming languages, development frameworks, executio

  8. SECOND BUYING AGENT

    CERN Multimedia

    SPL - SERVICES ACHATS

    2000-01-01

    Last year the buying agent LOGITRADE started operations on the CERN site, processing purchasing requests for well-defined families of products up to a certain value. It was planned from the outset that a second buying agent would be brought in to handle the remaining product families. So, according to that plan, the company CHARLES KENDALL will be commencing operations at CERN on 8 May 2000 in Building 73, 1st floor, offices 31 and 35 (phone and fax numbers to be announced).Each buying agent will have its own specific list of product families and will handle purchasing requests up to 10'000 CHF.Whenever possible they will provide the requested supplies at a price (including the cost of their own services) which must be equivalent to or lower than the price mentioned on the purchasing request, changing the supplier if necessary. If a lower price cannot be obtained, agents will provide the necessary administrative support free of charge.To ensure that all orders are processed in the best possible conditions, us...

  9. Radioactive diagnostic agent

    International Nuclear Information System (INIS)

    A dispersion of denatured aggregates of serum albumin to which tin is attached is prepared and lyophilized. A mixture of polycarboxylic acid and a disaccharide or monosaccharide is included in the dispersion in sufficient amount to reduce degradation during lyophilization and aging. The dispersion is suitable for radioactive labelling and use as a diagnostic agent

  10. Developing Enculturated Agents

    DEFF Research Database (Denmark)

    Rehm, Matthias

    Embodied Conversational Agents (ECAs) are complex multimodal systems with rich verbal and nonverbal repertoires. There human-like appearance raises severe expectations regarding natural communicative behaviors on the side of the user. But what is regarded as “natural” is to a large degree dependent...

  11. Biomimetic Emotional Learning Agents

    OpenAIRE

    Kenyon, Samuel H.

    2005-01-01

    This extended abstract proposes a type of AI agent comprised of: an autonomous real-time control system, low-level emotional learning (including a simple knowledge base that links homeostatic/innate drives to sensory perception states), and a novel sliding-priority drive motivation mechanism. Learning occurs in both phylogenetic and ontogenetic training.

  12. Agents of Change

    DEFF Research Database (Denmark)

    Hansen, Jens Aage; Lehmann, Martin

    2004-01-01

    at large, it emphasises universities as key change agents and providers in new learning, including tools such as project based and problem oriented learning (PBL) as well as information and communication technology (ICT); as providers of competent and motivated graduates to fill key positions in society...

  13. The need for agents

    DEFF Research Database (Denmark)

    Abolfazlian, Ali Reza Kian

    1996-01-01

    I denne artikel arbejder vi med begrebet Intelligent Software Agents (ISAs), som autonomous, social, reactive, proactive og subservient computer systemer. Baseret på socialt psykologiske argumenter viser jeg endvidere, hvordan både den menneskelige natur og det teknologiske stadium, som mennesket...

  14. Build Autonomic Agents with ABLE

    Institute of Scientific and Technical Information of China (English)

    吴吉义

    2007-01-01

    The IBM Agent Building and Learning Environment(ABLE) provides a lightweight Java~(TM) agent frame- work,a comprehensive JavaBeansTM library of intelligent software components,a set of development and test tools, and an agent platform.After the introduction to ABLE,classes and interfaces in the ABLE agent framework were put forward.At last an autonomic agent that is an ABLE-based architecture for incrementally building autonomic systems was discussed.

  15. Actions and Agents

    OpenAIRE

    Alonso, E.

    2014-01-01

    In this chapter the notion of agency in AI is presented..It has been argued that in order to behave rationally in prevalent software applications artificial entities would have to be autonomous and adaptive. Besides, rather than working with single, isolated systems the new trend in AI would need to focus on inherently social entities in the form of multi-agent systems. The chapter begins by introducing the notion of action in traditional AI systems, deliberative and reactive. Next, the i...

  16. Towards Soft Computing Agents

    Czech Academy of Sciences Publication Activity Database

    Neruda, Roman; Krušina, Pavel; Petrová, Zuzana

    2000-01-01

    Roč. 10, č. 5 (2000), s. 859-868. ISSN 1210-0552. [SOFSEM 2000 Workshop on Soft Computing. Milovy, 27.11.2000-28.11.2000] R&D Projects: GA ČR GA201/00/1489; GA ČR GA201/99/P057 Institutional research plan: AV0Z1030915 Keywords : hybrid systems * intelligent agents Subject RIV: BA - General Mathematics

  17. Sunscreening Agents: A Review

    OpenAIRE

    Latha, M. S.; Martis, Jacintha; Shobha, V; Sham Shinde, Rutuja; Bangera, Sudhakar; Krishnankutty, Binny; Bellary, Shantala; Varughese, Sunoj; Rao, Prabhakar; B R Naveen Kumar

    2013-01-01

    The increasing incidence of skin cancers and photodamaging effects caused by ultraviolet radiation has increased the use of sunscreening agents, which have shown beneficial effects in reducing the symptoms and reoccurrence of these problems. Many sunscreen compounds are in use, but their safety and efficacy are still in question. Efficacy is measured through indices, such as sun protection factor, persistent pigment darkening protection factor, and COLIPA guidelines. The United States Food an...

  18. Perioperative allergy: uncommon agents.

    Science.gov (United States)

    Caimmi, S; Caimmi, D; Cardinale, F; Indinnimeo, L; Crisafulli, G; Peroni, D G; Marseglia, G L

    2011-01-01

    Anesthesia may often be considered as a high-risk procedure and anaphylaxis remains a major cause of concern for anesthetists who routinely administer many potentially allergenic agents. Neuromuscular blocking agents, latex and antibiotics are the substances involved in most of the reported reactions. Besides these three agents, a wide variety of substances may cause an anaphylactic reaction during anesthesia. Basically all the administered drugs or substances may be potential causes of anaphylaxis. Among them, those reported the most in literature include hypnotics, opioids, local anesthetics, colloids, dye, Non-Steroidal Anti-Inflammatory Drugs (NSAIDs), Iodinated Contrast Media (ICM), antiseptics, aprotinin, ethylene oxyde and formaldehyde, and protamine and heparins. No premedication can effectively prevent an allergic reaction and a systematic preoperative screening is not justified for all patients; nevertheless, an allergy specialist should evaluate those patients with a history of anesthesia-related allergy. Patients must be fully informed of investigation results, and advised to provide a detailed report prior to future anesthesia. PMID:22014927

  19. Advanced scale conditioning agents

    International Nuclear Information System (INIS)

    A technical description of Advanced Scale Conditioning Agents (ASCA) technology was published in the May-June 2003 edition of the Nuclear Plant Journal. That article described the development of programs of advanced scale conditioning agents and specific types to maintain the secondary side of steam generators within a pressurized water reactor free of deposited corrosion products and corrosion-inducing contaminants to ensure their long-term operation. This article describes the first two plant applications of advanced scale conditioning agents implemented at Southern Nuclear Operating Company's Vogtle Units 1 and 2 during their 2002 scheduled outages to minimize tube degradation and maintain full power operation using the most effective techniques while minimizing outage costs. The goal was to remove three to four fuel cycles of deposits from each steam generator so that after future chemical cleaning activities, ASCAs could be used to maintain the cleanliness of the steam generators without the need for additional chemical cleaning efforts. The goal was achieved as well as several other benefits that resulted in cost savings to the plant

  20. SAM : Semantic Agent Model for SWRL rule-based agents

    OpenAIRE

    Subercaze, Julien; Maret, Pierre

    2010-01-01

    International audience SemanticWeb technologies are part of multi-agent engineering, especially regarding knowledge base support. Recent advances in the field of logic for the semantic web enable a new range of applications. Among them, programming agents based on semantic rules is a promising field. In this paper we present a semantic agent model that allows SWRL programming of agents. Our approach, based on the extended finite state machine concept, results in a three layers architecture...

  1. Peripheral Neuropathy and Agent Orange

    Science.gov (United States)

    ... Enter ZIP code here Peripheral Neuropathy and Agent Orange VA presumes Veterans' early-onset peripheral neuropathy is related to their exposure to Agent Orange or other herbicides during service when the disease ...

  2. Agents Play Mix-game

    CERN Document Server

    Gou, C

    2005-01-01

    In mix-game which is an extension of minority game, there are two groups of agents; group1 plays the majority game, but the group2 plays the minority game. This paper studies the change of the average winnings of agents and volatilities vs. the change of mixture of agents in mix-game model. It finds that the correlations between the average winnings of agents and the mean of local volatilities are different with different combinations of agent memory length when the proportion of agents in group 1 increases. This study result suggests that memory length of agents in group1 be smaller than that of agent in group2 when mix-game model is used to simulate the financial markets.

  3. The Power Trading Agent Competition

    OpenAIRE

    Ketter, W.; Collins, J.; REDDY, P; Flath, C.

    2011-01-01

    This is the specification for the Power Trading Agent Competition for 2011 (Power TAC 2011). Agents are simulations of electrical power brokers, who must compete with each other for both power production and consumption, and manage their portfolios.

  4. Mediating Performance Through Virtual Agents

    OpenAIRE

    Giannachi, Gabriella; Gillies, Marco; Kaye, Nick; Swapp, David

    2009-01-01

    This paper presents the process of creation of virtual agents used in a virtual reality performance. The performance aimed to investigate how drama and performance could inform the creation of virtual agents and also how virtual reality could raise questions for drama and performance. The virtual agents were based on the performance of 2 actors. This paper describes the process of preparing the actors, capturing their performances and transferring them to the virtual agents. A second set of a...

  5. Erythropoietic Agents and the Elderly

    OpenAIRE

    Agarwal, Neeraj; Prchal, Josef T.

    2008-01-01

    Erythropoietin is a peptide hormone that stimulates erythropoiesis. There are several agents in clinical use and in development, which either act as ligands for the cell surface receptors of erythropoietin or promote erythropoietin production that stimulates erythropoiesis. These are known as erythropoietic agents. The agents already in use include epoetin alfa, epoetin beta, and darbepoetin alfa. Newer agents stimulating erythropoiesis (such as continuous erythropoietin receptor activator (C...

  6. Cultural Differentiation of Negotiating Agents

    NARCIS (Netherlands)

    Hofstede, G.J.; Jonker, C.M.; Verwaart, D.

    2012-01-01

    Negotiations proceed differently across cultures. For realistic modeling of agents in multicultural negotiations, the agents must display culturally differentiated behavior. This paper presents an agent-based simulation model that tackles these challenges, based on Hofstede’s model of national cultu

  7. Cultural differentiation of negotiating agents

    NARCIS (Netherlands)

    Hofstede, G.J.; Jonker, C.M.; Verwaart, T.

    2010-01-01

    Negotiations proceed differently across cultures. For realistic modeling of agents in multicultural negotiations, the agents must display culturally differentiated behavior. This paper presents an agent-based simulation model that tackles these challenges, based on Hofstede’s model of national cultu

  8. Collaborating with Autonomous Agents

    Science.gov (United States)

    Trujillo, Anna C.; Cross, Charles D.; Fan, Henry; Hempley, Lucas E.; Motter, Mark A.; Neilan, James H.; Qualls, Garry D.; Rothhaar, Paul M.; Tran, Loc D.; Allen, B. Danette

    2015-01-01

    With the anticipated increase of small unmanned aircraft systems (sUAS) entering into the National Airspace System, it is highly likely that vehicle operators will be teaming with fleets of small autonomous vehicles. The small vehicles may consist of sUAS, which are 55 pounds or less that typically will y at altitudes 400 feet and below, and small ground vehicles typically operating in buildings or defined small campuses. Typically, the vehicle operators are not concerned with manual control of the vehicle; instead they are concerned with the overall mission. In order for this vision of high-level mission operators working with fleets of vehicles to come to fruition, many human factors related challenges must be investigated and solved. First, the interface between the human operator and the autonomous agent must be at a level that the operator needs and the agents can understand. This paper details the natural language human factors e orts that NASA Langley's Autonomy Incubator is focusing on. In particular these e orts focus on allowing the operator to interact with the system using speech and gestures rather than a mouse and keyboard. With this ability of the system to understand both speech and gestures, operators not familiar with the vehicle dynamics will be able to easily plan, initiate, and change missions using a language familiar to them rather than having to learn and converse in the vehicle's language. This will foster better teaming between the operator and the autonomous agent which will help lower workload, increase situation awareness, and improve performance of the system as a whole.

  9. Preoperative chemosensitivity testing as Predictor of Treatment benefit in Adjuvant stage III colon cancer (PePiTA): Protocol of a prospective BGDO (Belgian Group for Digestive Oncology) multicentric study

    International Nuclear Information System (INIS)

    Surgery is a curative treatment for patients with locally advanced colon cancer, but recurrences are frequent for those with stage III disease. FOLFOX adjuvant chemotherapy has been shown to improve recurrence-free survival and overall survival by more than 20% and is nowadays considered a standard of care. However, the vast majority of patients will not benefit from receiving cytotoxic drugs because they have either already been cured by surgery or because their tumor cells are resistant to the chemotherapy, for which predictive factors are still not available. Identifying which patients are unlikely to respond to adjuvant chemotherapy from among those who are eligible for such treatment would be a major step towards treatment personalization. It would spare such patients from unnecessary toxicities and would improve the allocation of societal healthcare resources. PePiTA is a prospective, multicenter, non-randomised trial built on the hypothesis that preoperative chemosensitivity testing using FDG-PET/CT before and after one course of FOLFOX can identify the patients who are unlikely to benefit from 6 months of adjuvant FOLFOX treatment for stage III colon cancer. The study’s primary objective is to examine the ability of PET/CT-assessed tumor FDG uptake after one course of preoperative chemotherapy to predict the outcome of adjuvant therapy, as measured by 3-year disease-free survival. Secondary objectives are to examine the predictive value of changes in PET/CT-assessed tumor FDG uptake on overall survival, to define the best cut-off value of FDG uptake for predicting treatment outcome, and to analyse the cost-effectiveness of such preoperative chemo-sensitivity testing. At study planning, exploratory translational research objectives were 1) to assess the predictive value of circulating tumor cells for disease-free survival, 2) to examine the predictive value of single nucleotide polymorphisms for disease-free survival with respect to genes related either to

  10. Agentes de información Information Agents

    Directory of Open Access Journals (Sweden)

    Alfonso López Yepes

    2005-12-01

    Full Text Available Este artículo realiza un repaso sobre las tipologías de agentes de información y describe aspectos como movilidad, racionalidad y adaptatividad, y el ajuste final de estos conceptos a entornos distribuidos como Internet, donde este tipo de agentes tienen un amplio grado de aplicación. Asimismo, se propone una arquitectura de agentes para un sistema multiagente de recuperación de información donde se aplica un paradigma documental basado en el concepto de ciclo documental.This article summarizes the main information agent types reflecting on issues such as mobility, rationality, adaptability and the final adjustment of this concepts to distributed environments such as the Internet, where this kind of agents has wide range application. Likewise, an information agent architecture is proposed to create a multi-agent information retrieval system in which a documentary paradigm based on the documentary cycle is developed.

  11. Secure Mobile Trade Agent

    Directory of Open Access Journals (Sweden)

    Musbah M. Aqe

    2007-01-01

    Full Text Available E-commerce on the internet has the ability to produce millions of transactions and a great number of merchants whose supply merchandise over the internet. As a result, it is difficult for entities to roam over every site on the internet and choose the best merchandise to trade. So, in this paper we introduced a mobile trade agent that visit the sites to gather and evaluate the information from merchant servers and decide to trade goods on behalf of the user. We observed that the combination of public key cryptosystem with distributed object technology make this proposed scheme more secure and efficient than the already existed schemes.

  12. Configuring Computational Agents

    Czech Academy of Sciences Publication Activity Database

    Beuster, G.; Neruda, Roman

    Halifax : Saint Mary's University, 2004 - (Zhuge, H.; Cheung, W.; Liu, J.), s. 57-62 ISBN 0-9734039-8-5. [International Workshop on Knowledge Grid and Grid Intelligence /2./. Beijing (CN), 20.09.2004] R&D Projects: GA AV ČR 1ET100300419 Grant ostatní: CZ-DE project(XX) CZE-03/023 Institutional research plan: CEZ:AV0Z1030915 Keywords : Bang 3 * multi-agent systems * computational intelligence models Subject RIV: BA - General Mathematics

  13. Holograms as Teaching Agents

    Science.gov (United States)

    Walker, Robin A.

    2013-02-01

    Hungarian physicist Dennis Gabor won the Pulitzer Prize for his 1947 introduction of basic holographic principles, but it was not until the invention of the laser in 1960 that research scientists, physicians, technologists and the general public began to seriously consider the interdisciplinary potentiality of holography. Questions around whether and when Three-Dimensional (3-D) images and systems would impact American entertainment and the arts would be answered before educators, instructional designers and students would discover how much Three-Dimensional Hologram Technology (3DHT) would affect teaching practices and learning environments. In the following International Symposium on Display Holograms (ISDH) poster presentation, the author features a traditional board game as well as a reflection hologram to illustrate conventional and evolving Three-Dimensional representations and technology for education. Using elements from the American children's toy Operation® (Hasbro, 2005) as well as a reflection hologram of a human brain (Ko, 1998), this poster design highlights the pedagogical effects of 3-D images, games and systems on learning science. As teaching agents, holograms can be considered substitutes for real objects, (human beings, organs, and animated characters) as well as agents (pedagogical, avatars, reflective) in various learning environments using many systems (direct, emergent, augmented reality) and electronic tools (cellphones, computers, tablets, television). In order to understand the particular importance of utilizing holography in school, clinical and public settings, the author identifies advantages and benefits of using 3-D images and technology as instructional tools.

  14. Amphoteric surface active agents

    Directory of Open Access Journals (Sweden)

    Eissa, A.M. F.

    1995-10-01

    Full Text Available 2-[trimethyl ammonium, triethyl ammonium, pyridinium and 2-amino pyridinium] alkanoates, four series of surface active agents containing carbon chain C12, C14, C16 and C18carbon atoms, were prepared. Their structures were characterized by microanalysis, infrared (IR and nuclear magnetic resonance (NMR. Surface and interfacial tension, Krafft point, wetting time, emulsification power, foaming height and critical micelle concentration (cmc were determined and a comparative study was made between their chemical structure and surface active properties. Antimicrobial activity of these surfactants was also determined.

    Se prepararon cuatro series de agentes tensioactivos del tipo 2-[trimetil amonio, trietil amonio, piridinio y 2-amino piridinio] alcanoatos, que contienen cadenas carbonadas con C12, C14, C16 y C18 átomos de carbono.
    Se determinaron la tensión superficial e interfacial, el punto de Krafft, el tiempo humectante, el poder de emulsionamiento, la altura espumante y la concentración critica de miscela (cmc y se hizo un estudio comparativo entre la estructura química y sus propiedades tensioactivas. Se determinó también la actividad antimicrobiana de estos tensioactivos. Estas estructuras se caracterizaron por microanálisis, infrarrojo (IR y resonancia magnética nuclear (RMN.

  15. Contrast agents for MRI

    International Nuclear Information System (INIS)

    Contrast agents are divided into two categories. The first one is paramagnetic compounds, including lanthanides like gadolinium, which mainly reduce the longitudinal (T1) relaxation property and result in a brighter signal. The second class consists of super-paramagnetic magnetic nanoparticles (SPMNPs) such as iron oxides, which have a strong effect on the transversal (T2) relaxation properties. SPMNPs have the potential to be utilized as excellent probes for magnetic resonance imaging (MRI). For instance, clinically benign iron oxide and engineered ferrite nanoparticles provide a good MRI probing capability for clinical applications. Furthermore, the limited magnetic property and inability to escape from the reticuloendothelial system (RES) of the used nanoparticles impede their further advancement. Therefore, it is necessary to develop the engineered magnetic nanoparticle probes for the next-generation molecular MRI. Considering the importance of MRI in diagnosing diseases, this paper presents an overview of recent scientific achievements in the development of new synthetic SPMNP probes whereby the sensitive and target-specific observation of biological events at the molecular and cellular levels is feasible. - Highlights: • This paper studies the contrast agents for MRI. • Fe―Co alloys and Mn-ferrites exhibit suitable contrast enhancement. • Nonhydrolytic thermal-decomposition synthetic method is suitable to produce MNPs. • This method allows controlling the size, magnetic dopants, magneto-crystalline anisotropy. • The increase in the superparamagnetic size leads to the contrast-enhancement

  16. Agent-oriented Software Engineering

    Institute of Scientific and Technical Information of China (English)

    GUAN Xu; CHENG Ming; LIU Bao

    2001-01-01

    An increasing number of computer systems are being viewed in terms of autonomous agents.Most people believe that agent-oriented approach is well suited to design and build complex systems. Yet. todate, little effort had been devoted to discuss the advantages of agent-oriented approach as a mainstreamsoftware engineering paradigm. Here both of this issues and the relation between object-oriented and agent-oriented will be argued. we describe an agent-oriented methodology and provide a quote for designing anauction system.

  17. Plumbagin, Vitamin K3 Analogue, Suppresses STAT3 Activation Pathway through Induction of Protein Tyrosine Phosphatase, SHP-1: Potential Role in Chemosensitization

    OpenAIRE

    Sandur, Santosh K.; Pandey, Manoj K.; Sung, Bokyung; Aggarwal, Bharat B.

    2010-01-01

    The activation of STAT3 has been linked with carcinogenesis through survival, proliferation, and angiogenesis of tumor cells. Agents that can suppress STAT3 activation have potential not only for prevention but also for treatment of cancer. In the present report, we investigated whether plumbagin (5-hydroxy-2-methyl-1,4-naphthoquinone), an analogue of Vitamin K and isolated from chitrak (Plumbago zeylanica), an Ayurvedic medicinal plant, can modulate the STAT3 pathway. We found that plumbagin...

  18. Learning models of intelligent agents

    Energy Technology Data Exchange (ETDEWEB)

    Carmel, D.; Markovitch, S. [Computer Science Dept., Haifa (Israel)

    1996-12-31

    Agents that operate in a multi-agent system need an efficient strategy to handle their encounters with other agents involved. Searching for an optimal interactive strategy is a hard problem because it depends mostly on the behavior of the others. In this work, interaction among agents is represented as a repeated two-player game, where the agents` objective is to look for a strategy that maximizes their expected sum of rewards in the game. We assume that agents` strategies can be modeled as finite automata. A model-based approach is presented as a possible method for learning an effective interactive strategy. First, we describe how an agent should find an optimal strategy against a given model. Second, we present an unsupervised algorithm that infers a model of the opponent`s automaton from its input/output behavior. A set of experiments that show the potential merit of the algorithm is reported as well.

  19. Flexible, secure agent development framework

    Science.gov (United States)

    Goldsmith; Steven Y.

    2009-04-07

    While an agent generator is generating an intelligent agent, it can also evaluate the data processing platform on which it is executing, in order to assess a risk factor associated with operation of the agent generator on the data processing platform. The agent generator can retrieve from a location external to the data processing platform an open site that is configurable by the user, and load the open site into an agent substrate, thereby creating a development agent with code development capabilities. While an intelligent agent is executing a functional program on a data processing platform, it can also evaluate the data processing platform to assess a risk factor associated with performing the data processing function on the data processing platform.

  20. UTBot: A Virtual Agent Platform for Teaching Agent System Design

    Directory of Open Access Journals (Sweden)

    In-Cheol Kim

    2007-02-01

    Full Text Available We introduce UTBot, a virtual agent platform for teaching agent system design. UTBot implements a client for the Unreal Tournament game server and Gamebots system. It provides students with the basic functionality required to start developing their own intelligent virtual agents to play autonomously UT games. UTBot includes a generic agent architecture, CAA (Context-sensitive Agent Architecture, a domain-specific world model, a visualization tool, several basic strategies (represented by internal modes and internal behaviors, and skills (represented by external behaviors. The CAA architecture can support complex long-term behaviors as well as reactive short-term behaviors. It also realizes high context-sensitivity of behaviors. We also discuss our experience using UTBot as a pedagogical tool for teaching agent system design in undergraduate Artificial Intelligence course.

  1. Mushrooms as therapeutic agents

    Directory of Open Access Journals (Sweden)

    Sushila Rathee

    2012-04-01

    Full Text Available Mushrooms have been known for their nutritional and culinary values and used as medicines and tonics by humans for ages. In modern terms, they can be considered as functional foods which can provide health benefits beyond the traditional nutrients. There are monographs that cover the medicinal and healing properties of some individual traditional mushrooms. There has been a recent upsurge of interest in mushrooms not only as a health food which is rich in protein but also as a source of biologically active compounds of medicinal value which include complementary medicine/dietary supplements for anticancer, antiviral, hepatoprotective, immunopotentiating and hypocholesterolemic agents. However the mechanisms of the various health benefits of mushrooms to humans still require intensive investigation, especially given the emergence of new evidence of their health benefits. In the present paper the medicinal potential of mushrooms is being discussed.

  2. Microencapsulation of chemotherapeutic agents

    International Nuclear Information System (INIS)

    Mixing various amounts of chemotherapeutic agents such as cisplatinum, 5-fluorouracil, mitomycin-C, and adriamycin with polymers such as poly-d, 1-lactide, ethylhydroxyethylcellulose, and polycaprolactone, several kinds of microcapsules were made. Among them, microcapsule made from ethylhydroxyethylcellulose showed best yield. Under light microscopy, the capsules were observed as particles with refractive properties. For the basic toxicity test, intraarterial administration of cisplatinum was done in 6 adult mongrel dogs. Follow-up angiography was accomplished in 2 wk intervals for 6 wks. Despite no significant difference in the histopathological examination between the embolized and normal kidneys, follow-up angiogram showed atrophy of renal cortex and diminished numbers of arterial branches in the embolized kidneys. In order to identify the structural properties of microcapsules, and to determine the drug content and the rate of release, further experiment is thought to be necessary. (Author)

  3. Hepatocytes as Immunological Agents.

    Science.gov (United States)

    Crispe, Ian N

    2016-01-01

    Hepatocytes are targeted for infection by a number of major human pathogens, including hepatitis B virus, hepatitis C virus, and malaria. However, hepatocytes are also immunological agents in their own right. In systemic immunity, they are central in the acute-phase response, which floods the circulation with defensive proteins during diverse stresses, including ischemia, physical trauma, and sepsis. Hepatocytes express a variety of innate immune receptors and, when challenged with pathogen- or damage-associated molecular patterns, can deliver cell-autonomous innate immune responses that may result in host defense or in immunopathology. Important human pathogens have evolved mechanisms to subvert these responses. Finally, hepatocytes talk directly to T cells, resulting in a bias toward immune tolerance. PMID:26685314

  4. MORBIDITY AGENTS: A REVIEW

    Directory of Open Access Journals (Sweden)

    Shrivastava Neelesh

    2011-09-01

    Full Text Available This paper discuss on clinical representation of morbid jealousy which often termed delusional jealousy or ‘Othello Syndrome’ is a psychiatric condition where a lover believes against all reason and their beloved is being sexually unfaithful. Patients will be preoccupied with their partner’s perceived lack of sexual fidelity and will often behave in an unacceptable or extreme way as they endeavor to prove their ideas. Misuse of any psychomotor is an important association cause morbidity jealousy agents, like CNS stimulants that release the catecholamine, particularly dopamine, from pre synaptic terminals substance should be treated as a priority. Where higher levels of violence are reported Sildenafil may be useful as a diagnostic as well as therapeutic test in such cases .Many studies have shown an association between high alcohol consumption and developing morbid jealousy. Amphetamine-induced psychosis has been extensively studied because of its close resemblance to schizophrenia.

  5. Agent Assignment for Process Management: Pattern Based Agent Performance Evaluation

    Science.gov (United States)

    Jablonski, Stefan; Talib, Ramzan

    In almost all workflow management system the role concept is determined once at the introduction of workflow application and is not reevaluated to observe how successfully certain processes are performed by the authorized agents. This paper describes an approach which evaluates how agents are working successfully and feed this information back for future agent assignment to achieve maximum business benefit for the enterprise. The approach is called Pattern based Agent Performance Evaluation (PAPE) and is based on machine learning technique combined with post processing technique. We report on the result of our experiments and discuss issues and improvement of our approach.

  6. TAp73-mediated the activation of C-jun N-terminal kinase enhances cellular chemosensitivity to cisplatin in ovarian cancer cells

    OpenAIRE

    Pingde Zhang; Stephanie Si Liu; Hextan Yuen Sheung Ngan

    2012-01-01

    P73, one member of the tumor suppressor p53 family, shares highly structural and functional similarity to p53. Like p53, the transcriptionally active TAp73 can mediate cellular response to chemotherapeutic agents in human cancer cells by up-regulating the expressions of its pro-apoptotic target genes such as PUMA, Bax, NOXA. Here, we demonstrated a novel molecular mechanism for TAp73-mediated apoptosis in response to cisplatin in ovarian cancer cells, and that was irrespective of p53 status. ...

  7. Odor Classification using Agent Technology

    Directory of Open Access Journals (Sweden)

    Sigeru OMATU

    2014-03-01

    Full Text Available In order to measure and classify odors, Quartz Crystal Microbalance (QCM can be used. In the present study, seven QCM sensors and three different odors are used. The system has been developed as a virtual organization of agents using an agent platform called PANGEA (Platform for Automatic coNstruction of orGanizations of intElligent Agents. This is a platform for developing open multi-agent systems, specifically those including organizational aspects. The main reason for the use of agents is the scalability of the platform, i.e. the way in which it models the services. The system models functionalities as services inside the agents, or as Service Oriented Approach (SOA architecture compliant services using Web Services. This way the adaptation of the odor classification systems with new algorithms, tools and classification techniques is allowed.

  8. Stability of Evolving Agent Populations

    CERN Document Server

    Briscoe, G

    2007-01-01

    Stability is perhaps the most desired feature in the systems that we design. It is important for us to be able to predict the response of a Multi-Agent System (MAS) to various environmental conditions prior to its actual deployment. The Chli-DeWilde agent stability measure views a MAS as a discrete time Markov chain with a potentially unknown transition probabilities. A MAS is considered to be stable when its state, a stochastic process, has converged to an equilibrium distribution. We investigate an extension of their agent stability definition to include MASs with evolutionary dynamics, focusing on evolving agent populations. Additionally, using our extended agent stability measure, we construct an entropy-based definition for the degree of instability. An example system, the Digital Ecosystem, is considered in detail to investigate the stability of an evolving agent population through simulations. The results are consistent with the original Chli-DeWilde measure.

  9. Agent-based enterprise integration

    Energy Technology Data Exchange (ETDEWEB)

    N. M. Berry; C. M. Pancerella

    1998-12-01

    The authors are developing and deploying software agents in an enterprise information architecture such that the agents manage enterprise resources and facilitate user interaction with these resources. The enterprise agents are built on top of a robust software architecture for data exchange and tool integration across heterogeneous hardware and software. The resulting distributed multi-agent system serves as a method of enhancing enterprises in the following ways: providing users with knowledge about enterprise resources and applications; accessing the dynamically changing enterprise; locating enterprise applications and services; and improving search capabilities for applications and data. Furthermore, agents can access non-agents (i.e., databases and tools) through the enterprise framework. The ultimate target of the effort is the user; they are attempting to increase user productivity in the enterprise. This paper describes their design and early implementation and discusses the planned future work.

  10. Mobile Agents for Digital Signage

    OpenAIRE

    SATOH, Ichiro

    2010-01-01

    International audience This paper presents an agent-based framework for building and operating context-aware multimedia content on digital signage in public/private spaces. It enables active and multimedia content to be composed from mobile agents, which can travel from computer to computer and provide multimedia content for advertising or user-assistant services to users. The framework automatically deploys their agents at computers near to their current positions to provide advertising o...

  11. An agent for ecological deliberation

    OpenAIRE

    Debenham, John; Sierra, Carles

    2010-01-01

    An agent architecture supports the two forms of deliberation used by human agents. Cartesian, constructivist rationalism leads to game theory, decision theory and logical models. Ecological rationalism leads to deliberative actions that are derived from agents’ prior interactions and are not designed; i.e., they are strictly emergent. This paper aims to address the scant attention paid by the agent community to the predominant form of deliberation used by mankind.

  12. Agent factory: towards social robots

    OpenAIRE

    O'Hare, G. M. P.; Duffy, Brian R.; Collier, Rem; Rooney, Colm, (Thesis); O'Donoghue, Ruadhan

    1999-01-01

    This paper advocates the application of multi-agent techniques in the realisation of social robotic behaviour. We present the Social Robot Architecture, which integrates the key elements of agent-hood and robotics in a coherent and systematic manner. This architecture seamlessly integrates, real world robots, multi-agent development tools, and VRML visualisation tools into a coherent whole. Using these elements, we deliver a development environment, which facilitates rapid prototyping of soci...

  13. Agent Systems in Software Engineering

    OpenAIRE

    Lazarou, Vasilios S.; Gardikiotis, Spyridon K.; Malevris, Nicos

    2008-01-01

    In this chapter, the application of multi-agent systems to tackle the software engineering task was outlined. The concentration was on the employment of agent technology in order to deal with distributed software systems and mainly distributed database applications and web applications. The rationale behind utilizing agent technology has to do with the multi-tier architecture and the associated inherent complication of distributed applications and the required interoperability of software res...

  14. Research on Negotiating Agent Development

    Institute of Scientific and Technical Information of China (English)

    WEI Ding-guo; PENG Hong

    2004-01-01

    The paper presents a flexible and effective method of development of negotiating agents.A strategy specification, which is specified by a state chart and defeasible rules, can be dynamically inserted into an agent shell incorporating a state chart interpreter and a defeasible logic inference engine, in order to yield a desirable agent.The set of desirable criteria and rules is required to be justified with different context of the application.

  15. Extending Agent Languages for Autonomy

    OpenAIRE

    Meneguzzi, Felipe Rech

    2008-01-01

    BDI agent languages provide a useful abstraction for complex systems comprised of interactive autonomous entities, but they have been used mostly in the context of single agents with a static plan library of behaviours invoked reactively. These languages provide a theoretically sound basis for agent design but are very limited in providing direct support for autonomy and societal cooperation needed for large scale systems. Some techniques for autonomy and cooperation have been explored in the...

  16. Radioactive scanning agents with stabilizer

    International Nuclear Information System (INIS)

    Stable compositions useful as technetium 99-based scintigraphic agents comprise gentisyl alcohol or a pharmaceutically-acceptable salt or ester thereof in combination with a pertechnetate reducing agent or dissolved in pertechnetate-99m (sup(99m)TcOsub(4)sup(-)) solution. The compositions are especially useful in combination with a phosphate or phosphonate material that carries the radionuclide to bone, thus providing a skeletal imaging agent

  17. Technetium diagnostic agent and carrier

    International Nuclear Information System (INIS)

    A stable sup(99m)Tc-labelled radioactive diagnostic agent is produced by contacting sup(99m)Tc-containing pertechnetate with a non-radioactive carrier comprising a chelating agent, a water-soluble reducing agent and a stabilizer. The stabilizer is chosen from ascorbic acid and erythorbic acid and their pharmaceutically acceptable salts and esters. A mole ratio of more than 100 moles ascorbic or erythorbic acid to 1 mole of reducing agent provides a stable composition at high levels of radioactivity

  18. Relational agents: A critical review

    DEFF Research Database (Denmark)

    Campbell, Robert H.; Grimshaw, Mark Nicholas; Green, Gill

    2009-01-01

    and non-player characters that can actively participate in such relationships. The focus of this review is relational agents, agents that can build long term socioemotional relationships with users. In virtual worlds, such agents are just starting to emerge; they are more common in other environments...... but remain few and far between. This review critically assesses the progress of relational agent development and research since their inception in 2005, proposes new areas of research and considers the potential for their exploitation in virtual worlds....

  19. Incorporating BDI Agents into Human-Agent Decision Making Research

    Science.gov (United States)

    Kamphorst, Bart; van Wissen, Arlette; Dignum, Virginia

    Artificial agents, people, institutes and societies all have the ability to make decisions. Decision making as a research area therefore involves a broad spectrum of sciences, ranging from Artificial Intelligence to economics to psychology. The Colored Trails (CT) framework is designed to aid researchers in all fields in examining decision making processes. It is developed both to study interaction between multiple actors (humans or software agents) in a dynamic environment, and to study and model the decision making of these actors. However, agents in the current implementation of CT lack the explanatory power to help understand the reasoning processes involved in decision making. The BDI paradigm that has been proposed in the agent research area to describe rational agents, enables the specification of agents that reason in abstract concepts such as beliefs, goals, plans and events. In this paper, we present CTAPL: an extension to CT that allows BDI software agents that are written in the practical agent programming language 2APL to reason about and interact with a CT environment.

  20. Plasmids encoding therapeutic agents

    Science.gov (United States)

    Keener, William K.

    2007-08-07

    Plasmids encoding anti-HIV and anti-anthrax therapeutic agents are disclosed. Plasmid pWKK-500 encodes a fusion protein containing DP178 as a targeting moiety, the ricin A chain, an HIV protease cleavable linker, and a truncated ricin B chain. N-terminal extensions of the fusion protein include the maltose binding protein and a Factor Xa protease site. C-terminal extensions include a hydrophobic linker, an L domain motif peptide, a KDEL ER retention signal, another Factor Xa protease site, an out-of-frame buforin II coding sequence, the lacZ.alpha. peptide, and a polyhistidine tag. More than twenty derivatives of plasmid pWKK-500 are described. Plasmids pWKK-700 and pWKK-800 are similar to pWKK-500 wherein the DP178-encoding sequence is substituted by RANTES- and SDF-1-encoding sequences, respectively. Plasmid pWKK-900 is similar to pWKK-500 wherein the HIV protease cleavable linker is substituted by a lethal factor (LF) peptide-cleavable linker.

  1. Gastrointestinal scanning agent

    International Nuclear Information System (INIS)

    An easily prepared radiolabeled gastrointestinal scanning agent is described. Technetium-99m has ideal characteristics for imaging the upper and lower GI tract and determining stomach emptying and intestinal transit time when used with an insoluble particulate material. For example, crystalline and amorphous calcium phosphate particles can be effectively labeled in a one-step process using sup(99m)TcO4 and SnCl2. These labeled particles have insignificant mass and when administered orally pass through the GI tract unchanged, without affecting the handling and density of the intestinal contents. Visualization of the esophageal entry into the stomach, the greater and lesser curvatures of the stomach, ejection into the duodenum, and rates of passage through the upper and lower GI tract are obtained. The slurry of sup(99m)TC particulate can be given rectally by enema. Good images of the cecum and the ascending, transverse, and descending colon are obtained. Mucosal folds and the splenic and hepatic flexures are visualized. The resilience of the large intestine is also readily visualized by pneumocolonographic techniques. (author)

  2. 2012 Survey of clothing agents

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    Clothing agents take part in China International Clothing and Accessories Fairs ( CHIC ) year by year. In order to attracting investment, they compared with each other at improving their originality and service levels. At the exhibition brands manufacturers and agents had a face-to-face communication,

  3. Topical agents in burn care

    Directory of Open Access Journals (Sweden)

    Momčilović Dragan

    2002-01-01

    Full Text Available Introduction Understanding of fluid shifts and recognition of the importance of early and appropriate fluid replacement therapy have significantly reduced mortality in the early post burn period. After the bum patient successfully passes the resuscitation period, the burn wound represents the greatest threat to survival. History Since the dawn of civilization, man has been trying to find an agent which would help burn wounds heal, and at the same time, not harm general condition of the injured. It was not until the XX century, after the discovery of antibiotics, when this condition was fulfilled. In 1968, combining silver and sulfadiazine, fox made silver-sulfadiazine, which is a 1% hydro-soluble cream and a superior agent in topical treatment of burns today. Current topical agents None of the topical antimicrobial agents available today, alone or combined, have the characteristics of ideal prophylactic agents, but they eliminate colonization of burn wound, and invasive infections are infrequent. With an excellent spectrum of activity, low toxicity, and ease of application with minimal pain, silver-sulfadiazine is still the most frequently used topical agent. Conclusion The incidence of invasive infections and overall mortality have been significantly reduced after introduction of topical burn wound antimicrobial agents into practice. In most burn patients the drug of choice for prophylaxis is silver sulfadiazine. Other agents may be useful in certain clinical situations.

  4. Agent Roles in Human Teams

    OpenAIRE

    Lewis, M.; Sycara, K.; Payne, T.R.

    2003-01-01

    In this paper, we describe results of a series of experiments investigating the effects of agent aiding on human teams. The role an agent played, its task, and the ease with which it communicated with its human teammates all influenced team behavior. Team supporting tasks such as relaying and reminding seemed particularly effective.

  5. Intelligent Agents in Physics Education

    Science.gov (United States)

    Sánchez-Guzmán, D.; Mora, César

    2010-07-01

    Intelligent Agents are being applied in a wide range of processes and everyday applications. Their development is not new, in recent years they have had an increased attention and design; like learning and mentoring tools. In this work we discuss the definition of what an intelligent agent is; how they are applied; how they look like; recent implementations of agents; agents as support in the learning process, more precisely intelligent tutors; their state in Latin-American countries and future developments and trends that will permit a better communication between people and agents. Also we present an Intelligent Tutor applied as a tool for improving high-school students' skills and reasoning for the first five topics of Mechanics curricula.

  6. Markov Tracking for Agent Coordination

    Science.gov (United States)

    Washington, Richard; Lau, Sonie (Technical Monitor)

    1998-01-01

    Partially observable Markov decision processes (POMDPs) axe an attractive representation for representing agent behavior, since they capture uncertainty in both the agent's state and its actions. However, finding an optimal policy for POMDPs in general is computationally difficult. In this paper we present Markov Tracking, a restricted problem of coordinating actions with an agent or process represented as a POMDP Because the actions coordinate with the agent rather than influence its behavior, the optimal solution to this problem can be computed locally and quickly. We also demonstrate the use of the technique on sequential POMDPs, which can be used to model a behavior that follows a linear, acyclic trajectory through a series of states. By imposing a "windowing" restriction that restricts the number of possible alternatives considered at any moment to a fixed size, a coordinating action can be calculated in constant time, making this amenable to coordination with complex agents.

  7. Agent Communications using Distributed Metaobjects

    Energy Technology Data Exchange (ETDEWEB)

    Goldsmith, Steven Y.; Spires, Shannon V.

    1999-06-10

    There are currently two proposed standards for agent communication languages, namely, KQML (Finin, Lobrou, and Mayfield 1994) and the FIPA ACL. Neither standard has yet achieved primacy, and neither has been evaluated extensively in an open environment such as the Internet. It seems prudent therefore to design a general-purpose agent communications facility for new agent architectures that is flexible yet provides an architecture that accepts many different specializations. In this paper we exhibit the salient features of an agent communications architecture based on distributed metaobjects. This architecture captures design commitments at a metaobject level, leaving the base-level design and implementation up to the agent developer. The scope of the metamodel is broad enough to accommodate many different communication protocols, interaction protocols, and knowledge sharing regimes through extensions to the metaobject framework. We conclude that with a powerful distributed object substrate that supports metaobject communications, a general framework can be developed that will effectively enable different approaches to agent communications in the same agent system. We have implemented a KQML-based communications protocol and have several special-purpose interaction protocols under development.

  8. Mobile agent driven by aspect

    Directory of Open Access Journals (Sweden)

    Youssef Hannad

    2010-11-01

    Full Text Available Domain application of mobile agents is quite large. They are used for network management and the monitoring of complex architecture. Mobile agent is also essential into specific software architecture such that adaptable grid architecture. Even if the concept of mobile agent seems to be obvious, the development is always complex because it needs to understand network features but also security features and negotiation algorithms. We present a work about an application of aspects dedicated to mobile agent development over a local network. At this level, the underlying protocol is called jini and allows managing several essential concepts such that short transaction and permission management. Three subsets of aspects are defined in this work. A part is for the description of agent host and its security level, accessible resource, etc. A second part is about mobile agent and their collaboration. This means how they can operate on an agent host with the respect of the execution context. All the results are illustrated through a distributed monitoring application called DMA. Its main objective is the observation of component servers.

  9. Intelligent Farmer Agent for Multi-Agent Ecological Simulations Optimization

    OpenAIRE

    Filipe Cruz; António Pereira; Pedro Valente; Pedro Duarte; Luis Paulo Reis

    2007-01-01

    This paper presents the development of a bivalve farmer agent interacting with a realistic ecological simulation system. The purpose of the farmer agent is to determine the best combinations of bivalve seeding areas in a large region, maximizing the production without exceeding the total allowed seeding area. A system based on simulated annealing, tabu search, genetic algorithms and reinforcement learning, was developed to minimize the number of iterations required to unravel a semi-optimum s...

  10. MDE and Mobile Agents : another reflexion on the agent migration

    OpenAIRE

    Gherbi, Tahar; Borne, Isabelle; Meslati, Djamel

    2009-01-01

    International audience Model Driven Engineering (MDE) is a software development approach family based on the use of models in the software construction. It allows the exploitation of models to simulate, estimate, understand, communicate and produce code. Mobile agents are a very interesting technology to develop applications for mobile and distributed environments. A mobile agent is essentially a computer program that acts autonomously on behalf of a user and travels through a network of h...

  11. Rapid in vivo Taxotere quantitative chemosensitivity response by 4.23 Tesla sodium MRI and histo-immunostaining features in N-Methyl-N-Nitrosourea induced breast tumors in rats

    Directory of Open Access Journals (Sweden)

    Wu Ed X

    2005-08-01

    Full Text Available Abstract Background Sodium weighted images can indicate sodium signal intensities from different features in the tumor before and 24 hours following administration of Taxotere. Aim To evaluate the association of in vivo intracellular sodium magnetic resonance image intensities with immuno-biomarkers and histopathological features to monitor the early tumor response to Taxotere chemotherapy in Methyl-Nitroso-Urea induced rat xenograft breast tumors. Methods and Materials Methyl-Nitroso-Urea (MNU induced rat xenograft breast tumors were imaged for sodium MRI and compared with tumor histology, immunostaining after 24 hours chemotherapy. Results Sodium MRI signal intensities represented sodium concentrations. Excised tumor histological sections showed different in vitro histological end points i.e. single strand DNA content of cell nuclei during cell cycle (G1/S-G2/M, distinct S or M histograms (Feulgen labeling to nuclear DNA content by CAS 200, mitotic figures and apoptosis at different locations of breast tumors. Necrosis and cystic fluid appeared gray on intracellular (IC sodium images while apoptosis rich regions appeared brighter on IC sodium images. After 24 hours Taxotere-treated tumors showed lower 'IC/EC ratio' of viable cells (65–76% with higher mitotic index; apoptotic tumor cells at high risk due to cytotoxicity (>70% with high apoptotic index; reduced proliferation index (270 vs 120 per high power field associated with enhanced IC sodium in vivo MR image intensities and decreased tumor size (3%; p in vivo associated with apoptosis and different pre-malignant features within 24 hours of exposure of cancer cells to anti-neoplastic Taxotere drug. Conclusion Sodium MRI imaging may be used as in vivo rapid drug monitoring method to evaluate Taxotere chemosensitivity response associated with neoplasia, apoptosis and tumor histology features.

  12. Knowledge mining using intelligent agents

    CERN Document Server

    Dehuri, Satchidananda

    2010-01-01

    ""Knowledge Mining Using Intelligent Agents"" explores the concept of knowledge discovery processes and enhances decision-making capability through the use of intelligent agents like ants, termites and honey bees. In order to provide readers with an integrated set of concepts and techniques for understanding knowledge discovery and its practical utility, this book blends two distinct disciplines - data mining and knowledge discovery process, and intelligent agents-based computing (swarm intelligence and computational intelligence). For the more advanced reader, researchers, and decision/policy

  13. Agent-oriented Software Engineering

    Institute of Scientific and Technical Information of China (English)

    MingCheng; XuGuan; BaoLiu

    2004-01-01

    An increasing number of computer systems are being viewed in terms of autonomous agents.Most people believe that agent-oriented approach is well suited to designing and building complex systems. Yet, to date, little effort had been devoted to discussing the advantages of agent-oriented approach as a mainstream software engineering paradiam.Here both of this issues and the relation between object-oriented and agentoriented will be argued.We describe an agent-oriented methodology and provide a quote for designing a auction system.

  14. TAp73-mediated the activation of c-Jun N-terminal kinase enhances cellular chemosensitivity to cisplatin in ovarian cancer cells.

    Directory of Open Access Journals (Sweden)

    Pingde Zhang

    Full Text Available P73, one member of the tumor suppressor p53 family, shares highly structural and functional similarity to p53. Like p53, the transcriptionally active TAp73 can mediate cellular response to chemotherapeutic agents in human cancer cells by up-regulating the expressions of its pro-apoptotic target genes such as PUMA, Bax, NOXA. Here, we demonstrated a novel molecular mechanism for TAp73-mediated apoptosis in response to cisplatin in ovarian cancer cells, and that was irrespective of p53 status. We found that TAp73 acted as an activator of the c-Jun N-terminal kinase (JNK signaling pathway by up-regulating the expression of its target growth arrest and DNA-damage-inducible protein GADD45 alpha (GADD45α and subsequently activating mitogen-activated protein kinase kinase-4 (MKK4. Inhibition of JNK activity by a specific inhibitor or small interfering RNA (siRNA significantly abrogated TAp73-mediated apoptosis induced by cisplatin. Furthermore, inhibition of GADD45α by siRNA inactivated MKK4/JNK activities and also blocked TAp73-mediated apoptosis induction by cisplatin. Our study has demonstrated that TAp73 activated the JNK apoptotic signaling pathway in response to cisplatin in ovarian cancer cells.

  15. Optimistic Agents are Asymptotically Optimal

    OpenAIRE

    Sunehag, Peter; Hutter, Marcus

    2012-01-01

    We use optimism to introduce generic asymptotically optimal reinforcement learning agents. They achieve, with an arbitrary finite or compact class of environments, asymptotically optimal behavior. Furthermore, in the finite deterministic case we provide finite error bounds.

  16. Agents containing chlorhexidine in dentistry

    OpenAIRE

    Lebedeva S.N.; Zemlyanichenko М.К.

    2011-01-01

    Aclinical definition of the efficacy of chlorhexidine-containing means for reducing the risk of dental caries and gingivitis with plastic caps. Chlorhexidine is an effective antimicrobial agent for the formation of individual programs for the prevention of dental caries

  17. Chemical Agents: Facts about Evacuation

    Science.gov (United States)

    ... Health Emergency Response Guide Reaching At-Risk Populations Chemical Agents: Facts About Evacuation Format: Select one PDF [ ... on Facebook Tweet Share Compartir Some kinds of chemical accidents or attacks, such as a train derailment ...

  18. PENETRATION ENHANCEMENT OF MEDICINAL AGENTS

    OpenAIRE

    Sharma Ganesh N.; Sanadya Jyotsana; Kaushik Avinash; Dwivedi Abha

    2012-01-01

    Many current therapeutic agents like antibiotics, ionizable and peptide drugs are impermeable or do not possess the requisite physicochemical properties for efficient transport through outer tissue barrier to attain therapeutic blood level. For this reason the delivery of such drugs through barriers is currently one of the major interests in pharmaceutical research. Penetration enhancers or promoters are agents that have no therapeutic properties of their own but can transport the sorption of...

  19. Agents in E-learning

    OpenAIRE

    S. Mencke; Dumke, R

    2007-01-01

    This paper presents a framework to describe thecrossover domain of e-learning and agent technology.Furthermore it is used to classify existing work and possiblestarting points for the future development of agenttechniques and technologies order to enhance theperformance and the effectiveness of several aspects of elearningsystems. Agents are not a new concept but their usein the field of e-learning constitutes a basis for consequentialadvances.

  20. Handling of injectable antineoplastic agents.

    OpenAIRE

    Knowles, R S; Virden, J E

    1980-01-01

    Although the clinical toxicity of antineoplastic drugs has been well documented there is little or no information on the problems that may arise on the handling and mishandling of such agents. This paper attempts to highlight the importance of taking precautions to prevent adverse effects resulting from contact with cytotoxic drugs during handling and to suggest a practical guide for the handling of such agents.

  1. Biocontrol agents in signalling resistance

    OpenAIRE

    Loon, L C; Pieterse, C.M.J.

    2002-01-01

    The mechanisms by which biological control agents suppress disease comprise competition for nutrients, notably iron, production of antibiotics, and secretion of lytic enzymes, as well as inducing resistance in the plant. The former three mechanisms act primarily on the pathogen by decreasing its activity, growth, and/or survival and require the biocontrol agent and the pathogen to be in close proximity. Because microorganisms with biocontrol properties and soilborne pathogens are both attract...

  2. Epidemic Spreading with External Agents

    OpenAIRE

    Banerjee, Siddhartha; Gopalan, Aditya; Das, Abhik Kumar; Shakkottai, Sanjay

    2012-01-01

    We study epidemic spreading processes in large networks, when the spread is assisted by a small number of external agents: infection sources with bounded spreading power, but whose movement is unrestricted vis-\\`a-vis the underlying network topology. For networks which are `spatially constrained', we show that the spread of infection can be significantly speeded up even by a few such external agents infecting randomly. Moreover, for general networks, we derive upper-bounds on the order of the...

  3. Locating Agents in RFID Architectures

    OpenAIRE

    Abdel-Naby, Sameh; Giorgini, Paolo

    2006-01-01

    The use of software agents can create an “intelligent” interface between users’ preferences and the back‐end systems. Agents are now able to interact and communicate with each other, forming a virtual community and feeding back the user with suggestions. Innovative systems related to Asset Tracking, Inventory and Shelving architectures are more often involving advanced communication techniques (e.g., RFID); these systems are responsible for user authentication and objects verification. RFID s...

  4. Towards Building Computational Agent Schemes

    Czech Academy of Sciences Publication Activity Database

    Beuster, Gerd; Krušina, Pavel; Neruda, Roman; Rydvan, Pavel

    Wien : SpringerVerlag, 2003 - (Pearson, D.; Steele, N.; Albrecht, R.), s. 210-215 ISBN 3-211-00743-1. [ICANNGA'2003 /6./. Roanne (FR), 23.04.2003-25.04.2003] R&D Projects: GA ČR GA201/02/0428 Institutional research plan: AV0Z1030915 Keywords : multi agent system s * intelligent agent s * hybrid models Subject RIV: BA - General Mathematics

  5. Cooperation of Computational Intelligence Agents

    Czech Academy of Sciences Publication Activity Database

    Neruda, Roman

    Los Alamitos : IEEE Computer Society, 2006 - (Smari, W.; McQuay, W.), s. 256-263 ISBN 0-9785699-0-3. [International Symposium on Collaborative Technologies and System s. Las Vegas (US), 14.05.2006-17.05.2006] R&D Projects: GA AV ČR(CZ) 1ET100300419 Institutional research plan: CEZ:AV0Z10300504 Keywords : multi - agent system s * cooperative agent s * computational intelligence * ontologies Subject RIV: IN - Informatics, Computer Science

  6. Bacteriocins as potential anticancer agents

    OpenAIRE

    Sukhraj eKaur; Sumanpreet eKaur

    2015-01-01

    Cancer remains one of the leading causes of deaths worldwide, despite advances in its treatment and detection. The conventional chemotherapeutic agents used for the treatment of cancer have nonspecific toxicity towards normal body cells that cause various side effects. Secondly, cancer cells are known to develop chemotherapy resistance in due course of treatment. Thus, the demand for novel anti-cancer agents is increasing day by day. Some of the experimental studies have reported the therapeu...

  7. Bacteriocins as Potential Anticancer Agents

    OpenAIRE

    Kaur, Sumanpreet; Kaur, Sukhraj

    2015-01-01

    Cancer remains one of the leading causes of deaths worldwide, despite advances in its treatment and detection. The conventional chemotherapeutic agents used for the treatment of cancer have non-specific toxicity toward normal body cells that cause various side effects. Secondly, cancer cells are known to develop chemotherapy resistance in due course of treatment. Thus, the demand for novel anti-cancer agents is increasing day by day. Some of the experimental studies have reported the therapeu...

  8. Business Intelligence using Software Agents

    OpenAIRE

    Ana-Ramona BOLOGA; Razvan BOLOGA

    2011-01-01

    This paper presents some ideas about business intelligence today and the importance of developing real time business solutions. The authors make an exploration of links between business intelligence and artificial intelligence and focuses specifically on the implementation of software agents-based systems in business intelligence. There are briefly presented some of the few solutions proposed so far that use software agents properties for the benefit of business intelligence. The authors then...

  9. What makes virtual agents believable?

    Science.gov (United States)

    Bogdanovych, Anton; Trescak, Tomas; Simoff, Simeon

    2016-01-01

    In this paper we investigate the concept of believability and make an attempt to isolate individual characteristics (features) that contribute to making virtual characters believable. As the result of this investigation we have produced a formalisation of believability and based on this formalisation built a computational framework focused on simulation of believable virtual agents that possess the identified features. In order to test whether the identified features are, in fact, responsible for agents being perceived as more believable, we have conducted a user study. In this study we tested user reactions towards the virtual characters that were created for a simulation of aboriginal inhabitants of a particular area of Sydney, Australia in 1770 A.D. The participants of our user study were exposed to short simulated scenes, in which virtual agents performed some behaviour in two different ways (while possessing a certain aspect of believability vs. not possessing it). The results of the study indicate that virtual agents that appear resource bounded, are aware of their environment, own interaction capabilities and their state in the world, agents that can adapt to changes in the environment and exist in correct social context are those that are being perceived as more believable. Further in the paper we discuss these and other believability features and provide a quantitative analysis of the level of contribution for each such feature to the overall perceived believability of a virtual agent.

  10. 46 CFR Sec. 2 - General Agents' authority.

    Science.gov (United States)

    2010-10-01

    ... RESPONSIBILITY OF GENERAL AGENTS TO UNDERTAKE EMERGENCY REPAIRS IN FOREIGN PORTS Sec. 2 General Agents' authority. The General Agents are hereby delegated authority to undertake for the account of the...

  11. Interactions of ionic and nonionic contrast agents with thrombolytic agents

    International Nuclear Information System (INIS)

    Both the ionic and nonionic intravascular contrast media have been used before and after the administration of thrombolytic agents to evaluate clot lysis during angioplasty and the treatment of myocardial infarction. In experimental animal models, the authors found that the clot lytic efficacy of streptokinase, streptokinase-plasminogen complex, and tissue plasminogen activator (t-PA) is markedly augmented if these agents are administered within 1 hour after the angiographic producers. Furthermore, contrast agents injected after the administration of t-Pa exhibit a synergistic action. In stimulated models administration of one ionic contrast medium (Angiovist, Berlex, Wayne, NJ) and two nonionic contrast agents (Isovue-370, Squibb Diagnostics, New Brunswick, NJ; Omnipaque-350, Winthrop, NY) 15 minutes before the administration of t-PA resulted in marked enhancement of the lytic activity. Although the mechanism of this interaction is unknown at this time, it should be taken into consideration in the treatment of patients with myocardial infarction, in whom contrast agents are continually used to evaluate the therapeutic lysis. Furthermore, this interaction may be partly related to the therapeutic efficacy and/or hemorrhagic actions observed

  12. 3-Bromopyruvic acid, a hexokinase II inhibitor, is an effective antitumor agent on the hepatoma cells : in vitro and in vivo findings.

    Science.gov (United States)

    Gong, Lei; Wei, Yuhua; Yu, Xin; Peng, Jirun; Leng, Xisheng

    2014-06-01

    Over-expressed in cancer cells, hexokinase II (HK II) forms a mitochondrial complex, which promotes cancer survival. 3- Bromopyruvic acid (3-BrPA) dissociates HK II from this complex, causing cell death, and thus, having an anti-tumor effect. The design of this study was to first analyze the expression of HK II in the hepatoma cell line, BEL-7402, then investigate the effects of 3-Br-PA on these cells, and finally, discuss its potential for clinical usage. HK II expression was detected in BEL-7402 cells by immunocytochemistry and reverse transcriptase polymerase chain reaction (RT-PCR). In vitro treatment of cells with 3-BrPA significantly inhibited their growth, as evaluated by MTT assay and adenosine triphosphate-tumor chemosensitivity assay (ATP-TCA). To analyze the in vivo function and safety of this drug, a tumor model was established by subcutaneously implanting hepatic cancer cells into nude mice. 3-BrPA treatment (50 mg/kg ip. daily, 6 days/week for three weeks) was effective in the animal model by attenuating tumor growth and causing tumor necrosis. Toxic signs were not observed. The acute toxicity study provided an LD50 of 191.7 mg/kg for 3-BrPA. Taken together, our in vitro and in vivo analyses suggest that 3-BrPA exerts anti-hepatoma effects, and may be an effective pharmacological agent for the treatment of hepatocellular carcinoma. PMID:24738957

  13. Geo-Agents: Design and Implement

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Geo-Agents, a multi-agent system that processes distr ib utedgeospatial information and geospatial service was presented. Firstly, the requirement for distributed geographical information process was discussed, and the architecture of Geo-Agents was introduced. Then in-depth discussions were r aised on agent system implementation, such as the basic agent, agent advertising , message passing, and collaborating. An example was also given to explain the p roblem solving process.

  14. Special issue about advances in Physical Agents

    OpenAIRE

    Cazorla Quevedo, Miguel Ángel; Matellán Olivera, Vicente

    2011-01-01

    Nowadays, there are a lot of Spanish groups which are doing research in areas related with physical agents: they use agent-based technologies concepts, especially industrial applications, robotics and domotics (physical agents) and applications related to the information society, (software agents) highlighting the similarities and synergies among physical and software agents. In this special issue we will show several works from those groups, focusing on the recent advances in Physical Agents.

  15. Learning by Observation of Agent Software Images

    OpenAIRE

    Costa, Paulo Roberto; Botelho, Luís Miguel

    2014-01-01

    Learning by observation can be of key importance whenever agents sharing similar features want to learn from each other. This paper presents an agent architecture that enables software agents to learn by direct observation of the actions executed by expert agents while they are performing a task. This is possible because the proposed architecture displays information that is essential for observation, making it possible for software agents to observe each other. The agent architecture support...

  16. Regulation of death induction and chemosensitizing action of 3-bromopyruvate in myeloid leukemia cells: energy depletion, oxidative stress, and protein kinase activity modulation.

    Science.gov (United States)

    Calviño, Eva; Estañ, María Cristina; Sánchez-Martín, Carlos; Brea, Rocío; de Blas, Elena; Boyano-Adánez, María del Carmen; Rial, Eduardo; Aller, Patricio

    2014-02-01

    3-Bromopyruvate (3-BrP) is an alkylating, energy-depleting drug that is of interest in antitumor therapies, although the mechanisms underlying its cytotoxicity are ill-defined. We show here that 3-BrP causes concentration-dependent cell death of HL60 and other human myeloid leukemia cells, inducing both apoptosis and necrosis at 20-30 μM and a pure necrotic response at 60 μM. Low concentrations of 3-BrP (10-20 μM) brought about a rapid inhibition of glycolysis, which at higher concentrations was followed by the inhibition of mitochondrial respiration. The combination of these effects causes concentration-dependent ATP depletion, although this cannot explain the lethality at intermediate 3-BrP concentrations (20-30 μM). The oxidative stress caused by exposure to 3-BrP was evident as a moderate overproduction of reactive oxygen species and a concentration-dependent depletion of glutathione, which was an important determinant of 3-BrP toxicity. In addition, 3-BrP caused glutathione-dependent stimulation of p38 mitogen-activated protein kinase (MAPK), mitogen-induced extracellular kinase (MEK)/extracellular signal-regulated kinase (ERK), and protein kinase B (Akt)/mammalian target of rapamycin/p70S6K phosphorylation or activation, as well as rapid LKB-1/AMP kinase (AMPK) activation, which was later followed by Akt-mediated inactivation. Experiments with pharmacological inhibitors revealed that p38 MAPK activation enhances 3-BrP toxicity, which is conversely restrained by ERK and Akt activity. Finally, 3-BrP was seen to cooperate with antitumor agents like arsenic trioxide and curcumin in causing cell death, a response apparently mediated by both the generation of oxidative stress induced by 3-BrP and the attenuation of Akt and ERK activation by curcumin. In summary, 3-BrP cytotoxicity is the result of several combined regulatory mechanisms that might represent important targets to improve therapeutic efficacy. PMID:24307199

  17. Colitis associated with biological agents

    Directory of Open Access Journals (Sweden)

    Hugh James Freeman

    2012-01-01

    Full Text Available In the past, there has been considerable focus on a host of drugs and chemicals that may produce colonic toxicity. Now, a variety of new biological monoclonal antibody agents, usually administered by infusion, have appeared in the clinical realm over the last decade or so to treat different chronic inflammatory or malignant disorders.For some of these agents, adverse effects have been documented, including apparently new forms of immune-mediated inflammatory bowel disease. In some, only limited symptoms have been recorded, but in others, severe colitis with serious complications, such as bowel perforation has been recorded. In others, adverse effects may have a direct vascular or ischemic basis, while other intestinal effects may be related to a superimposed infection. Some new onset cases of ulcerative colitis or Crohn’s disease may also be attributed to the same agents used to treat these diseases, or be responsible for disease exacerbation. Dramatic and well documented side effects have been observed with ipilimumab, a humanized monoclonal antibody developed to reduce and overcome cytotoxic T-lymphocyte antigen 4, a key negative feedback regulator of the T-cell anti-tumor response. This agent has frequently been used in the treatment of different malignancies, notably, malignant melanoma. Side effects with this agent occur in up to 40% and these are believed to be largely immune-mediated. One of these is a form of enterocolitis that may be severe, and occasionally, fatal. Other agents include rituximab (an anti-CD20 monoclonal antibody, bevacizumab (a monoclonal antibody against the vascular endothelial growth factor and anti-tumor necrosis factor agents, including infliximab, adalimumab and etanercept.

  18. [Microvascular architecture of human tumors transplanted in nude mice--its relationship to sensitivity to antineoplastic agents].

    Science.gov (United States)

    Okazaki, M; Kubota, T; Hanatani, Y; Maruyama, K; Tsuyuki, K; Nakada, M; Asanuma, F; Ishibiki, K; Abe, O

    1982-08-01

    Microangiographic study was performed with ten human tumors serially transplanted into nude mice to clarify the role of tumor vessels on the chemosensitivity of the human tumors. Five gastric carcinomas, two colon carcinomas, one breast carcinoma, one cholangiocarcinoma, and one hemangiopericytoma were used for the experiments. Seven tumors revealed hypervascular network of vessels, whereas hypovascular patterns of tumor vessels were observed in the other three tumors. It was found that the histologically differentiated tumors were hypervascular and undifferentiated tumors were hypovascular, with statistically significant differences (p less than 0.05). Each tumor possessed the vascular network similar to human tumors originated from the same organs. No discernible changes of microangiographic features were noticed by serial transfers. As the chemosensitivities of these tumors depended mainly on their original tissues, these chemosensitivities could not be explained only by tumor vascularities or drug transferences. However, in the tumors with similar chemosensitive spectra, less susceptible tumors were observed to possess the irregular vascular networks in comparison with sensitive strains. From these considerations, tumor vessels were thought to have some role on vascular flow and drug transference which affected chemosensitivity of human tumors. PMID:7184456

  19. A multi-agent architecture for geosimulation of moving agents

    Science.gov (United States)

    Vahidnia, Mohammad H.; Alesheikh, Ali A.; Alavipanah, Seyed Kazem

    2015-10-01

    In this paper, a novel architecture is proposed in which an axiomatic derivation system in the form of first-order logic facilitates declarative explanation and spatial reasoning. Simulation of environmental perception and interaction between autonomous agents is designed with a geographic belief-desire-intention and a request-inform-query model. The architecture has a complementary quantitative component that supports collaborative planning based on the concept of equilibrium and game theory. This new architecture presents a departure from current best practices geographic agent-based modelling. Implementation tasks are discussed in some detail, as well as scenarios for fleet management and disaster management.

  20. Sensors for detecting biological agents

    Directory of Open Access Journals (Sweden)

    Kim E. Sapsford

    2008-03-01

    Full Text Available Biological agents including viruses, bacteria, and other naturally occurring pathogenic organisms, along with the toxins they produce, are considered far harder to detect and defend against than chemical agents. Here we provide an overview of the predominant molecular sensing technologies for the detection of these agents. This includes biosensing strategies based upon use of antibodies, genomic analysis, biochemical testing, other recognition interactions, and cellular-based responses. We survey some popular sensing approaches, illustrate them with current examples showing how they have been applied, and discuss their intrinsic benefits and potential liabilities. Lastly, within the context of security applications, some approaches for integrating sensing technologies into field-portable devices are discussed.

  1. Agent review phase one report.

    Energy Technology Data Exchange (ETDEWEB)

    Zubelewicz, Alex Tadeusz; Davis, Christopher Edward; Bauer, Travis LaDell

    2009-12-01

    This report summarizes the findings for phase one of the agent review and discusses the review methods and results. The phase one review identified a short list of agent systems that would prove most useful in the service architecture of an information management, analysis, and retrieval system. Reviewers evaluated open-source and commercial multi-agent systems and scored them based upon viability, uniqueness, ease of development, ease of deployment, and ease of integration with other products. Based on these criteria, reviewers identified the ten most appropriate systems. The report also mentions several systems that reviewers deemed noteworthy for the ideas they implement, even if those systems are not the best choices for information management purposes.

  2. Dopamine agents for hepatic encephalopathy

    DEFF Research Database (Denmark)

    Junker, Anders Ellekær; Als-Nielsen, Bodil; Gluud, Christian;

    2014-01-01

    BACKGROUND: Patients with hepatic encephalopathy may present with extrapyramidal symptoms and changes in basal ganglia. These changes are similar to those seen in patients with Parkinson's disease. Dopamine agents (such as bromocriptine and levodopa, used for patients with Parkinson's disease) have...... therefore been assessed as a potential treatment for patients with hepatic encephalopathy. OBJECTIVES: To evaluate the beneficial and harmful effects of dopamine agents versus placebo or no intervention for patients with hepatic encephalopathy. SEARCH METHODS: Trials were identified through the Cochrane...... the trials followed participants after the end of treatment. Only one trial reported adequate bias control; the remaining four trials were considered to have high risk of bias. Random-effects model meta-analyses showed that dopamine agents had no beneficial or detrimental effect on hepatic...

  3. Multi-Agent Software Engineering

    International Nuclear Information System (INIS)

    This paper proposed an alarm-monitoring system for people based on multi-agent using maps. The system monitors the users physical context using their mobile phone. The agents on the mobile phones are responsible for collecting, processing and sending data to the server. They can determine the parameters of their environment by sensors. The data are processed and sent to the server. On the other side, a set of agents on server can store this data and check the preconditions of the restrictions associated with the user, in order to trigger the appropriate alarms. These alarms are sent not only to the user who is alarmed to avoid the appeared restriction, but also to his supervisor. The proposed system is a general purpose alarm system that can be used in different critical application areas. It has been applied for monitoring the workers of radiation sites. However, these workers can do their activity tasks in the radiation environments safely

  4. Monitoring presence of chemical agents

    International Nuclear Information System (INIS)

    The specification describes a case for use with a hand-portable chemical agent detector for continuously monitoring an atmosphere for the presence of predetermined chemical agents. The detector having means for ionizing air samples and providing at an output terminal electrical signals representative of the mobility spectrum of ionized chemical vapours produced by the ionizing means. The case comprises means for defining a chamber in the case for supporting and removably enclosing the detector, means for communicating ambient atmosphere to the chamber, electrical circuit means in the case, the circuit means being adapted to be detachably connected to the detector output terminal when the detector is positioned in the chamber and being responsive to the electrical signals for producing an alarm signal when the signals detect a chemical agent concentration in the atmosphere exceeding a predetermined concentration level, and alarm means responsive to the alarm signal. (author)

  5. Erythropoietic agents and the elderly.

    Science.gov (United States)

    Agarwal, Neeraj; Prchal, Josef T

    2008-10-01

    Erythropoietin (Epo) is a peptide hormone that stimulates erythropoiesis. There are several agents in clinical use and in development that either act as ligands for the cell surface receptors of Epo or promote Epo production, which stimulates erythropoiesis. These are known as erythropoietic agents. The agents already in use include epoetin alfa, epoetin beta, and darbepoetin alfa. Newer agents under active investigation include continuous erythropoietin receptor activator (CERA) or proline hydroxylase inhibitors that increase hypoxia-inducible factor-1 (HIF-1), thereby stimulating Epo production and iron availability and supply. Erythropoietic agents have been shown to promote neuronal regeneration and to decrease post-stroke infarct size in mouse models. They have also been reported to shorten survival when used to treat anemia in many cancer patients and to increase thromboembolism. In contrast, rapid decrease of Epo levels as observed in astronauts and high-altitude dwellers upon rapid descent to sea level leads to the decrease of erythroid mass, a phenomenon known as "neocytolysis." The relative decrease in the serum Epo level is known to occur in some subjects with otherwise unexplained anemia of aging. Anemia by itself is a predictor of poor physical function in the elderly and is a significant economic burden on society. One out of every five persons in the United States will be elderly by 2050. Erythropoietic agents, by preventing and treating otherwise unexplained anemias of the elderly and anemia associated with other disease conditions of the elderly, have the potential to improve the functional capacity and to decrease the morbidity and mortality in the elderly, thereby alleviating the overall burden of medical care in society. PMID:18809098

  6. Autonomous sensor manager agents (ASMA)

    Science.gov (United States)

    Osadciw, Lisa A.

    2004-04-01

    Autonomous sensor manager agents are presented as an algorithm to perform sensor management within a multisensor fusion network. The design of the hybrid ant system/particle swarm agents is described in detail with some insight into their performance. Although the algorithm is designed for the general sensor management problem, a simulation example involving 2 radar systems is presented. Algorithmic parameters are determined by the size of the region covered by the sensor network, the number of sensors, and the number of parameters to be selected. With straight forward modifications, this algorithm can be adapted for most sensor management problems.

  7. An overview of inotropic agents.

    Science.gov (United States)

    Vroom, Margreeth B

    2006-09-01

    The use of inotropic agents has been surrounded by many controversies. Recent guidelines for the treatment of patients with chronic and acute heart failure have elucidated some of the issues, but many remain. As a result, a substantial variability in the use of agents between institutions and caregivers remains, which mainly results from the lack of uniform data in the literature. Prospective randomized trials with a long-term follow-up and sufficient power are clearly needed, and a number of trials are currently in progress. PMID:16959760

  8. Building Multi-Agent Systems Using Jason

    DEFF Research Database (Denmark)

    Boss, Niklas Skamriis; Jensen, Andreas Schmidt; Villadsen, Jørgen

    2010-01-01

    Technical University of Denmark (DTU). A part of this course was a short introduction to the multi-agent framework Jason, which is an interpreter for AgentSpeak, an agent-oriented programming language. As the final project in this course a solution to the Multi-Agent Programming Contest from 2007, the Gold...

  9. Using Agent to Coordinate Web Services

    CERN Document Server

    Liu, C H; Chen, Jason J Y

    2009-01-01

    Traditionally, agent and web service are two separate research areas. We figure that, through agent communication, agent is suitable to coordinate web services. However, there exist agent communication problems due to the lack of uniform, cross-platform vocabulary. Fortunately, ontology defines a vocabulary. We thus propose a new agent communication layer and present the web ontology language (OWL)-based operational ontologies that provides a declarative description. It can be accessed by various engines to facilitate agent communication. Further, in our operational ontologies, we define the mental attitudes of agents that can be shared among other agents. Our architecture enhanced the 3APL agent platform, and it is implemented as an agent communication framework. Finally, we extended the framework to be compatible with the web ontology language for service (OWL-S), and then develop a movie recommendation system with four OWL-S semantic web services on the framework. The benefits of this work are: 1) dynamic ...

  10. Tc-99m imaging agents

    International Nuclear Information System (INIS)

    A wide range of pharmaceuticals for labeling with Tc-99m, developed by the Soreq Radiopharmaceuticals Department, is described. Details of the production and quality control of 13 kits are given, as well as the range of results required for consistently high quality imaging agents

  11. Antibacterial activities of antineoplastic agents.

    OpenAIRE

    Bodet, C A; Jorgensen, J H; Drutz, D J

    1985-01-01

    Fourteen antineoplastic agents were examined for in vitro antibacterial activity against 101 aerobic and anaerobic bacterial isolates representing indigenous human microflora and selected opportunistic pathogens. Only 5-fluorouracil, mitomycin, and etoposide demonstrated inhibitory effects at achievable plasma concentrations, while the remaining drugs lacked appreciable antibacterial activities.

  12. Raspberry Pi for secret agents

    CERN Document Server

    Sjogelid, Stefan

    2015-01-01

    This book is an easy-to-follow guide with practical examples in each chapter. Suitable for the novice and expert alike, each topic provides a fast and easy way to get started with exciting applications and also guides you through setting up the Raspberry Pi as a secret agent toolbox.

  13. Identity Management in Agent Systems

    NARCIS (Netherlands)

    Brazier, F.M.T.; Groot, de D.R.A.

    2006-01-01

    If agent-based applications are to be used in large scale, open environments, security is a main issue; digital identity management (DIDM) an essential element. DIDM is needed to be able to determine the rights and obligations of the four main

  14. Kriitikute lemmikfilm on "Agent Sinikael"

    Index Scriptorium Estoniae

    2003-01-01

    Eesti Filmiajakirjanike Ühing andis kümnendat korda välja auhinda Aasta film 2002. Parimaks filmiks tunnistati mängufilm "Agent Sinikael" : režissöör Marko Raat. Viimane sai preemiaks Neitsi Maali kuju ja 12 000 krooni

  15. Improving agents using reliable communication

    Science.gov (United States)

    Zheng, Jinbin

    2013-10-01

    Recent advances in introspective modalities and linear time symmetries do not necessarily obviate the need for web browsers [1]. In our research, we disprove the exploration of agents, which embodies the appropriate principles of electrical engineering. Here we demonstrate that even though semaphores and XML [1] are mostly incompatible, randomized algorithms and write-back caches are mostly incompatible.

  16. Foodborne illness and microbial agents

    Science.gov (United States)

    Foodborne illnesses result from the consumption of food containing microbial agents such as bacteria, viruses, parasites or food contaminated by poisonous chemicals or bio-toxins. Pathogen proliferation is due to nutrient composition of foods, which are capable of supporting the growth of microorgan...

  17. Bridging humans via agent networks

    International Nuclear Information System (INIS)

    Recent drastic advance in telecommunication networks enabled the human organization of new class, teleorganization, which differ from any existing organization in that the organization which is easy to create by using telecommunication networks is virtual and remote, that people can join multiple organizations simultaneously, and that the organization can involve people who may not know each other. In order to enjoy the recent advance in telecommunication, the agent networks to help people organize themselves are needed. In this paper, an architecture of agent networks, in which each agent learns the preference or the utility functioin of the owner, and acts on behalf of the owner in maintaining the organization, is proposed. When an agent networks supports a human organization, the conventional human interface is divided into personal and social interfaces. The functionalities of the social interface in teleconferencing and telelearning were investigated. In both cases, the existence of B-ISDN is assumed, and the extension to the business meeting scheduling using personal handy phone (PHS) networks with personal digital assistant (PDA) terminals is expected. These circumstances are described. Mutual selection protocols (MSP) and their dynamic properties are explained. (K.I.)

  18. Anchor Toolkit - a secure mobile agent system

    OpenAIRE

    Mudumbai, Srilekha S.; Johnston, William; Essiari, Abdelilah

    2008-01-01

    Mobile agent technology facilitates intelligent operation in software systems with less human interaction. Major challenge to deployment of mobile agents include secure transmission of agents and preventing unauthorized access to resources between interacting systems, as either hosts, or agents, or both can act maliciously. The Anchor toolkit, designed by LBNL, handles the transmission and secure management of mobile agents in a heterogeneous distributed computing environment. It provide...

  19. Providing Reliable Agents for Electronic Commerce

    OpenAIRE

    Straßer, Markus; Rothermel, Kurt; Maihöfer, Christian

    1998-01-01

    It is widely agreed that mobile agents in conjunction with WWW technology will provide the technical foundation for future electronic commerce. A prerequisite for the use of mobile agents in a commercial environment is, that agents have to be executed reliable, independent of communication and node failure. In this paper, we first present a recently proposed fault-tolerant protocol to ensure the exactly-once execution of an agent by monitoring the agents execut...

  20. Halide test agent replacement study

    Energy Technology Data Exchange (ETDEWEB)

    Banks, E.M.; Freeman, W.P.; Kovach, B.J. [and others

    1995-02-01

    The intended phaseout of the chlorofluorocarbons (CFCs) from commercial use required the evaluation of substitute materials for the testing for leak paths through both individual adsorbers and installed adsorbent banks. The American Society of Mechanical Engineers (ASME) Committee on Nuclear Air and Gas Treatment (CONAGT) is in charge of maintaining the standards and codes specifying adsorbent leak test methods for the nuclear safety related air cleaning systems. The currently published standards and codes cite the use of R-11, R-12 and R-112 for leak path test agents. All of these compounds are CFCs. There are other agencies and organizations (USDOE, USDOD and USNRC) also specifying testing for leak paths or in some cases for special life tests using the above compounds. The CONAGT has recently developed criteria for the suitability evaluation of substitute test agents. On the basis of these criteria, several compounds were evaluated for their acceptability as adsorbent bed leak and life test agents. The ASME CONAGT Test Agent Qualification Criteria. The test agent qualification is based on the following parameters: (1) Similar retention times on activated carbons at the same concentration levels as one of the following: R-11, R-12, R-112 or R-112a. (2) Similar lower detection limit sensitivity and precision in the concentration range of use as R-11, R-12, R-112 and R-112a. (3) Gives the same in-place leak test results as R-11, R-12, R-112, or R-112a. (4) Chemical and radiological stability under the use conditions. (5) Causes no degradation of the carbon and its impregnant or of the other NATS components under the use conditions. (6) Is listed in the USEPA Toxic Substances Control Act (TSCA) inventory for commercial use.

  1. Biologic agents in juvenile spondyloarthropathies.

    Science.gov (United States)

    Katsicas, María Martha; Russo, Ricardo

    2016-01-01

    The juvenile spondyloarthropathies (JSpA) are a group of related rheumatic diseases characterized by involvement of peripheral large joints, axial joints, and entheses (enthesitis) that begin in the early years of life (prior to 16(th) birthday).The nomenclature and concept of spondyloarthropathies has changed during the last few decades. Although there is not any specific classification of JSpA, diseases under the spondyloarthropathy nomenclature umbrella in the younger patients include: the seronegative enthesitis and arthropathy (SEA) syndrome, juvenile ankylosing spondylitis, reactive arthritis, and inflammatory bowel disease-associated arthritis. Moreover, the ILAR criteria for Juvenile Idiopathic Arthritis includes two categories closely related to spondyloarthritis: Enthesitis-related arthritis and psoriatic arthritis.We review the pathophysiology and the use of biological agents in JSpA. JSpA are idiopathic inflammatory diseases driven by an altered balance in the proinflammatory cytokines. There is ample evidence on the role of tumor necrosis factor (TNF) and interleukin-17 in the physiopathology of these entities. Several non-biologic and biologic agents have been used with conflicting results in the treatment of these complex diseases. The efficacy and safety of anti-TNF agents, such as etanercept, infliximab and adalimumab, have been analysed in controlled and uncontrolled trials, usually showing satisfactory outcomes. Other biologic agents, such as abatacept, tocilizumab and rituximab, have been insufficiently studied and their role in the therapy of SpA is uncertain. Interleukin-17-blocking agents are promising alternatives for the treatment of JSpA patients in the near future. Recommendations for the treatment of patients with JSpA have recently been proposed and are discussed in the present review. PMID:26968522

  2. Migration Dynamics in Artificial Agent Societies

    Directory of Open Access Journals (Sweden)

    Harjot Kaur

    2014-02-01

    Full Text Available An Artificial Agent Society can be defined as a collection of agents interacting with each other for some purpose and/or inhabiting a specific locality, possibly in accordance to some common norms/rules. These societies are analogous to human and ecological societies, and are an expanding and emerging field in research about social systems. Social networks, electronic markets and disaster management organizations can be viewed as such artificial (open agent societies and can be best understood as computational societies. Members of such artificial agent societies are heterogeneous intelligent software agents which are operating locally and cooperating and coordinating with each other in order to achieve goals of an agent society. These artificial agent societies have some kind of dynamics existing in them in terms of dynamics of Agent Migration, Role-Assignment, Norm- Emergence, Security and Agent-Interaction. In this paper, we have described the dynamics of agent migration process, starting from the various types of agent migration, causes or reasons for agent migration, consequences of agent migration, and an agent migration framework to model the its behavior for migration of agents between societies.

  3. Laser interrogation of surface agents (LISA) for chemical agent reconnaissance

    Science.gov (United States)

    Higdon, N. S.; Chyba, Thomas H.; Richter, Dale A.; Ponsardin, Patrick L.; Armstrong, Wayne T.; Lobb, C. T.; Kelly, Brian T.; Babnick, Robert D.; Sedlacek, Arthur J., III

    2002-06-01

    Laser Interrogation of Surface Agents (LISA) is a new technique which exploits Raman scattering to provide standoff detection and identification of surface-deposited chemical agents. ITT Industries, Advanced Engineering and Sciences Division is developing the LISA technology under a cost-sharing arrangement with the US Army Soldier and Biological Chemical Command for incorporation on the Army's future reconnaissance vehicles. A field-engineered prototype LISA-Recon system is being designed to demonstrate on-the- move measurements of chemical contaminants. In this article, we will describe the LISA technique, data form proof-of- concept measurements, the LISA-Recon design, and some of the future realizations envisioned for military sensing applications.

  4. The New Agent: A Qualitative Study to Strategically Adapt New Agent Professional Development

    Science.gov (United States)

    Baker, Lauri M.; Hadley, Gregg

    2014-01-01

    The qualitative study reported here assessed the needs of agents related to new agent professional development to improve the current model. Agents who participated in new agent professional development within the last 5 years were selected to participate in focus groups to determine concerns and continued needs. Agents enjoyed networking and…

  5. Big Data Solution for CTBT Monitoring Using Global Cross Correlation

    Science.gov (United States)

    Gaillard, P.; Bobrov, D.; Dupont, A.; Grenouille, A.; Kitov, I. O.; Rozhkov, M.

    2014-12-01

    Due to the mismatch between data volume and the performance of the Information Technology infrastructure used in seismic data centers, it becomes more and more difficult to process all the data with traditional applications in a reasonable elapsed time. To fulfill their missions, the International Data Centre of the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO/IDC) and the Département Analyse Surveillance Environnement of Commissariat à l'Energie atomique et aux énergies alternatives (CEA/DASE) collect, process and produce complex data sets whose volume is growing exponentially. In the medium term, computer architectures, data management systems and application algorithms will require fundamental changes to meet the needs. This problem is well known and identified as a "Big Data" challenge. To tackle this major task, the CEA/DASE takes part during two years to the "DataScale" project. Started in September 2013, DataScale gathers a large set of partners (research laboratories, SMEs and big companies). The common objective is to design efficient solutions using the synergy between Big Data solutions and the High Performance Computing (HPC). The project will evaluate the relevance of these technological solutions by implementing a demonstrator for seismic event detections thanks to massive waveform correlations. The IDC has developed an expertise on such techniques leading to an algorithm called "Master Event" and provides a high-quality dataset for an extensive cross correlation study. The objective of the project is to enhance the Master Event algorithm and to reanalyze 10 years of waveform data from the International Monitoring System (IMS) network thanks to a dedicated HPC infrastructure operated by the "Centre de Calcul Recherche et Technologie" at the CEA of Bruyères-le-Châtel. The dataset used for the demonstrator includes more than 300,000 seismic events, tens of millions of raw detections and more than 30 terabytes of continuous seismic data from the primary IMS stations. In this talk, we will present the Master Event algorithm and the associated workflow, we will give an overview of the designed technical solutions (from the building blocks to the global infrastructure), and we will show the preliminary results at a regional scale.

  6. Uganda's participation in CTBT activities and earthquake monitoring

    International Nuclear Information System (INIS)

    Earthquake occurrence in Uganda is mostly related to East Africa Rift System. The country's western border lies within the Western branch of this system while the Eastern branch is only 200 km from its eastern border. The two tectonic features contribute to seismicity in Uganda. These are the Aswar shear zone running from Nimule at the border of Uganda and Sudan, to Mount Elgon on the Eastern border and Katonga fault break which cuts across the country from the foot hills of mount Rwenzori to the Western side of Lake Victoria. This unique tectonic setting makes Uganda one of most seismically active countries on the African continet as exemplified by some destructive earthquakes that have hit the country. For this reason the Government of uganda is in the process of setting up an earthquake monitoring system, the National Seismological Network, with efficient detectability, efficient data transmission and processing facilities so that earthquakes in Uganda can be properly assessed and seismic hazard studies of the country cunducted. The objectives of the said network, the seismic developments for the last two decades and its current satus are described

  7. Inhibition of phosphatidylinositol 3-kinase promotes tumor cell resistance to chemotherapeutic agents via a mechanism involving delay in cell cycle progression

    Energy Technology Data Exchange (ETDEWEB)

    McDonald, Gail T.; Sullivan, Richard; Pare, Genevieve C.; Graham, Charles H., E-mail: grahamc@queensu.ca

    2010-11-15

    Approaches to overcome chemoresistance in cancer cells have involved targeting specific signaling pathways such as the phosphatidylinositol 3-kinase (PI3K) pathway, a stress response pathway known to be involved in the regulation of cell survival, apoptosis and growth. The present study determined the effect of PI3K inhibition on the clonogenic survival of human cancer cells following exposure to various chemotherapeutic agents. Treatment with the PI3K inhibitors LY294002 or Compound 15e resulted in increased survival of MDA-MB-231 breast carcinoma cells after exposure to doxorubicin, etoposide, 5-fluorouracil, and vincristine. Increased survival following PI3K inhibition was also observed in DU-145 prostate, HCT-116 colon and A-549 lung carcinoma cell lines exposed to doxorubicin. Increased cell survival mediated by LY294002 was correlated with a decrease in cell proliferation, which was linked to an increase in the proportion of cells in the G{sub 1} phase of the cell cycle. Inhibition of PI3K signaling also resulted in higher levels of the cyclin-dependent kinase inhibitors p21{sup Waf1/Cip1} and p27{sup Kip1}; and knockdown of p27{sup kip1} with siRNA attenuated resistance to doxorubicin in cells treated with LY294002. Incubation in the presence of LY294002 after exposure to doxorubicin resulted in decreased cell survival. These findings provide evidence that PI3K inhibition leads to chemoresistance in human cancer cells by causing a delay in cell cycle; however, the timing of PI3K inhibition (either before or after exposure to anti-cancer agents) may be a critical determinant of chemosensitivity.

  8. Inhibition of phosphatidylinositol 3-kinase promotes tumor cell resistance to chemotherapeutic agents via a mechanism involving delay in cell cycle progression

    International Nuclear Information System (INIS)

    Approaches to overcome chemoresistance in cancer cells have involved targeting specific signaling pathways such as the phosphatidylinositol 3-kinase (PI3K) pathway, a stress response pathway known to be involved in the regulation of cell survival, apoptosis and growth. The present study determined the effect of PI3K inhibition on the clonogenic survival of human cancer cells following exposure to various chemotherapeutic agents. Treatment with the PI3K inhibitors LY294002 or Compound 15e resulted in increased survival of MDA-MB-231 breast carcinoma cells after exposure to doxorubicin, etoposide, 5-fluorouracil, and vincristine. Increased survival following PI3K inhibition was also observed in DU-145 prostate, HCT-116 colon and A-549 lung carcinoma cell lines exposed to doxorubicin. Increased cell survival mediated by LY294002 was correlated with a decrease in cell proliferation, which was linked to an increase in the proportion of cells in the G1 phase of the cell cycle. Inhibition of PI3K signaling also resulted in higher levels of the cyclin-dependent kinase inhibitors p21Waf1/Cip1 and p27Kip1; and knockdown of p27kip1 with siRNA attenuated resistance to doxorubicin in cells treated with LY294002. Incubation in the presence of LY294002 after exposure to doxorubicin resulted in decreased cell survival. These findings provide evidence that PI3K inhibition leads to chemoresistance in human cancer cells by causing a delay in cell cycle; however, the timing of PI3K inhibition (either before or after exposure to anti-cancer agents) may be a critical determinant of chemosensitivity.

  9. CATS-based Agents That Err

    Science.gov (United States)

    Callantine, Todd J.

    2002-01-01

    This report describes preliminary research on intelligent agents that make errors. Such agents are crucial to the development of novel agent-based techniques for assessing system safety. The agents extend an agent architecture derived from the Crew Activity Tracking System that has been used as the basis for air traffic controller agents. The report first reviews several error taxonomies. Next, it presents an overview of the air traffic controller agents, then details several mechanisms for causing the agents to err in realistic ways. The report presents a performance assessment of the error-generating agents, and identifies directions for further research. The research was supported by the System-Wide Accident Prevention element of the FAA/NASA Aviation Safety Program.

  10. Biological effects of mutagenic agents

    International Nuclear Information System (INIS)

    There is an increasing body of evidence that mutagenic agents (biological, chemical and physical) play an important role in the etiology of human diseases. Mutations may occur in the germinal as well as in the somatic cells. Mutations of the germ cells may result on infertility or fertilization of damaged cells, the later leading to abortion or birth of a malformed fetus. Somatic-cells mutations may have various biological effects, depending on the period of the human life at which the mutation occurs. If it occurs during the prenatal life, a teratogenic or carcinogenic effect will be observed. If the somatic cell is damaged during the postnatal life, this will lead to neoplastic transformation. Therefore it is extremely important to know the mutagenic, teratogenic and carcinogenic effects of various biological, chemical and physical agents in order to eliminate them from our environment. (author). 13 refs, 4 figs, 1 tab

  11. Extension agents and conflict narratives

    DEFF Research Database (Denmark)

    Bond, Jennifer Lauren

    2016-01-01

    Purpose: This work investigated the narratives of development extensionists in relation to natural resource conflict, in order to understand the competing discourses surrounding the wicked problems of natural resource management in Laikipia County, Kenya. Methodology: Q methodology was used to...... professionals from government, non-government, faith-based and private organizations. Findings: Four factors were elicited from the data, labelled—A: ‘Improved Leadership’; B: ‘Resource-centred conflict’; C: ‘Improved Governance’; and D: ‘Improved Management’. Practical Implications: Narratives of neo...... resource conflict. Originality: This work contributes to a growing body of literature interested in the role of extension agents in conflict management. By applying Q methodology, this work has shown that while extension agents are involved in conflict management, their perceptions of these conflicts are...

  12. Agent Based Individual Traffic Guidance

    DEFF Research Database (Denmark)

    Wanscher, Jørgen

    This thesis investigates the possibilities in applying Operations Research (OR) to autonomous vehicular traffic. The explicit difference to most other research today is that we presume that an agent is present in every vehicle - hence Agent Based Individual Traffic guidance (ABIT). The next...... that the system can be divided into two separate constituents. The immediate dispersion, which is used for small areas and quick response, and the individual alleviation, which considers the longer distance decision support. Both of these require intrinsicate models and cost functions which at the...... beginning of the project were not previously considered. We define a special inseparable cost function and develop a solution complex capable of using this cost function. In relation to calibration and estimation of statistical models used for dynamic route guidance we worked with generating random number...

  13. [Infectious agents and autoimmune diseases].

    Science.gov (United States)

    Riebeling-Navarro, C; Madrid-Marina, V; Camarena-Medellín, B E; Peralta-Zaragoza, O; Barrera, R

    1992-01-01

    In this paper the molecular aspects of the relationships between infectious agents and autoimmune diseases, the mechanisms of immune response to infectious agents, and the more recent hypotheses regarding the cause of autoimmune diseases are discussed. The antigens are processed and selected by their immunogenicity, and presented by HLA molecules to the T cell receptor. These events initiate the immune response with the activation and proliferation of T-lymphocytes. Although there are several hypotheses regarding the cause of autoimmune diseases and too many findings against and in favor of them, there is still no conclusive data. All these hypothesis and findings are discussed in the context of the more recent advances. PMID:1615352

  14. Oral agents in multiple sclerosis.

    Science.gov (United States)

    Lorefice, L; Fenu, G; Frau, J; Coghe, G C; Marrosu, M G; Cocco, E

    2015-01-01

    Multiple sclerosis (MS) is a complex autoimmune disease of the central nervous system. Disease-modifying drugs licensed for MS treatment have been developed to reduce relapse rates and halt disease progression. The majority of current MS drugs involve regular, parenteral administration, affecting long-term adherence and thus reducing treatment efficacy. Over the last two decades great progress has been made towards developing new MS therapies with different modes of action and biologic effects. In particular, oral drugs have generated much interest because of their convenience and positive impact on medication adherence. Fingolimod was the first launched oral treatment for relapsing-remitting MS; recently, Teriflunomide and Dimethyl fumarate have also been approved as oral disease-modifying agents. In this review, we summarize and discuss the history, pharmacodynamics, efficacy, and safety of oral agents that have been approved or are under development for the selective treatment of MS. PMID:25924620

  15. Logical Theories for Agent Introspection

    DEFF Research Database (Denmark)

    Bolander, Thomas

    2004-01-01

    Artificial intelligence systems (agents) generally have models of the environments they inhabit which they use for representing facts, for reasoning about these facts and for planning actions. Much intelligent behaviour seems to involve an ability to model not only one's external environment but...... self-reference. In the standard approach taken in artificial intelligence, the model that an agent has of its environment is represented as a set of beliefs. These beliefs are expressed as logical formulas within a formal, logical theory. When the logical theory is expressive enough to allow...... introspective reasoning, the presence of self-reference causes the theory to be prone to inconsistency. The challenge therefore becomes to construct logical theories supporting introspective reasoning while at the same time ensuring that consistency is retained. In the thesis, we meet this challenge by devising...

  16. Injectable agents affecting subcutaneous fats.

    Science.gov (United States)

    Chen, David Lk; Cohen, Joel L; Green, Jeremy B

    2015-09-01

    Mesotherapy is an intradermal or subcutaneous injection of therapeutic agents to induce local effects, and was pioneered in Europe during the 1950s. For the past 2 decades, there has been significant interest in the use of mesotherapy for minimally invasive local fat contouring. Based on the theorized lipolytic effects of the agent phosphatidylcholine, initial attempts involved its injection into subcutaneous tissue. With further studies, however, it became apparent that the activity attributed to phosphatidylcholine mesotherapy was due to the adipolytic effects of deoxycholate, a detergent used to solubilize phosphatidylcholine. Since then, clinical trials have surfaced that demonstrate the efficacy of a proprietary formulation of deoxycholate for local fat contouring. Current trials on mesotherapy with salmeterol, a b-adrenergic agonist and lipolysis stimulator, are underway-with promising preliminary results as well. PMID:26566569

  17. Curcumin-albumin conjugates as an effective anti-cancer agent with immunomodulatory properties.

    Science.gov (United States)

    Aravind, S R; Krishnan, Lissy K

    2016-05-01

    Curcumin (diferuloylmethane) is an active ingredient in turmeric (Curcuma longa) with anti-inflammatory, antioxidant, chemopreventive, chemosensitization, and radiosensitization properties. Conjugation of curcumin (Curc) to albumin (Alb) has been found to increase the aqueous solubility of the drug. The current study aimed to prove the safe use of the Curc-Alb conjugate in animals and to demonstrate that it retains drug action both in vitro and in vivo. Dalton's lymphoma ascites (DLA) cell viability was inhibited by the Curc-Alb conjugate in a dose dependent manner in vitro, as evidenced by the MTT assay. Administration of up to 11.4 mg of conjugated curcumin per kg body weight to healthy animals was non-toxic both in terms of lethality and weight loss. Histological analysis of vital organs (kidney, liver and spleen) also did not show toxic effects. Favorable immuno-modulatory activity was observed after continuous administration of sub-acute doses of the conjugate which caused increase in total leukocyte count, platelet count, and viable cell count in bone marrow, and enhanced proliferation of lymphocyte in vitro upon culture. In vivo studies in the DLA tumor model in mice demonstrated that conjugated drug induces tumor reduction and prevention. Significant tumor reduction was observed when the Curc-Alb conjugate was administered intraperitoneally in DLA-induced mice after 1 day (prevention therapy) and 7 days (reduction therapy) of tumor induction. There was significant reduction in both tumor volume and tumor cell numbers in the treated animals as well as a marked increase in their mean survival time and percent increase in life span. The effect was greater when the conjugate was administered soon after inducing the tumor as compared to when treatment was started after allowing tumor to grow for 7 days. Thus, the results of the present study suggest that curcumin albumin conjugate has immunomodulatory and tumor growth inhibition properties. The study postulates

  18. Topical agents in burn care

    OpenAIRE

    Momčilović Dragan

    2002-01-01

    Introduction Understanding of fluid shifts and recognition of the importance of early and appropriate fluid replacement therapy have significantly reduced mortality in the early post burn period. After the bum patient successfully passes the resuscitation period, the burn wound represents the greatest threat to survival. History Since the dawn of civilization, man has been trying to find an agent which would help burn wounds heal, and at the same time, not harm general condition of the injure...

  19. Building Hybrid Soft Computing Agents

    Czech Academy of Sciences Publication Activity Database

    Neruda, Roman

    Anheim : ACTA Press, 2003 - (Castillo, O.), s. 7-11 ISBN 0-88986-347-4. [IASTED International Conference on Neural Networks and Computational Intelligence. Cancun (MX), 19.05.2003-21.05.2003] R&D Projects: GA ČR(CZ) GP201/03/P163 Institutional research plan: CEZ:AV0Z1030915 Keywords : evolutionary algorithms * multi - agent system s * hybrid methods Subject RIV: BA - General Mathematics

  20. MSA AGENT FOR MULTIMEDIA APPLICATIONS

    OpenAIRE

    Aruna Rani; A. K. Gautam

    2011-01-01

    The MSA Agent is the software developed to design rectangular and U slotted micro strip antenna.It is applied for the various applications such as satellite communications, UHF applications. Within the multimedia frequency range the developed software is tested and analyzed for various results. The software is developed using genetic algorithm. This provides extra flexibility and new capability to design rectangular and U slotted micro strip antenna for multimedia application also. The result...

  1. Provably Bounded-Optimal Agents

    OpenAIRE

    Russell, S J; Subramanian, D.

    1995-01-01

    Since its inception, artificial intelligence has relied upon a theoretical foundation centered around perfect rationality as the desired property of intelligent systems. We argue, as others have done, that this foundation is inadequate because it imposes fundamentally unsatisfiable requirements. As a result, there has arisen a wide gap between theory and practice in AI, hindering progress in the field. We propose instead a property called bounded optimality. Roughly speaking, an agent is boun...

  2. Autonomous Behavior of Computational Agents

    Czech Academy of Sciences Publication Activity Database

    Vaculín, Roman; Neruda, Roman

    Wien : Springer-Verlag, 2005 - (Ribiero, B.; Albrecht, R.; Dobnikar, A.; Pearson, D.; Steele, N.), s. 514-517 ISBN 3-211-24934-6. [ICANNGA'2005 /7./. Coimbra (PT), 21.03.2005-23.03.2005] R&D Projects: GA AV ČR 1ET100300419 Institutional research plan: CEZ:AV0Z10300504 Keywords : computational agents * autonomous behavior * reasoning Subject RIV: BA - General Mathematics

  3. Agent Simulation of Chain Bankruptcy

    OpenAIRE

    Yuichi Ikeda; Yoshi Fujiwara; Wataru Souma; Hideaki Aoyama; Hiroshi Iyetomi

    2007-01-01

    We have conducted an agent-based simulation of chain bankruptcy. The propagation of credit risk on a network, i.e., chain bankruptcy, is the key to nderstanding largesized bankruptcies. In our model, decrease of revenue by the loss of accounts payable is modeled by an interaction term, and bankruptcy is defined as a capital deficit. Model parameters were estimated using financial data for 1,077 listed Japanese firms. Simulations of chain bankruptcy on the real transaction network consisting o...

  4. Crimen organizado y agente encubierto

    OpenAIRE

    Herrero Reus, Ignacio

    2014-01-01

    Uno de los objetivos de la justicia penal actual es la lucha contra la criminalidad organizada, bien por su propia naturaleza de “crimen organizado”, bien porque presenta elementos trasnacionales que impiden su investigación a fondo. Todo ello exige la creación de recursos que permitan la investigación de dichos delitos, recursos como el de infiltración de los agentes policiales, objeto del trabajo.

  5. Dimensions and Issues of Mobile Agent Technology

    Directory of Open Access Journals (Sweden)

    Yashpal Singh

    2012-09-01

    Full Text Available Mobile Agent is a type of software system which acts “intelligently” on one’s behalf with the feature of autonomy, learning ability and most importantly mobility. Now mobile agents are gaining interest in the research community. In this article mobile agents will be addressed as tools for mobile computing. Mobile agents have been used in applications ranging from network management to information management. We present mobile agent concept, characteristics, classification, need, applications and technical constraints in the mobile technology. We also provide a brief case study about how mobile agent is used for information retrieval.

  6. Antagonistic formation motion of cooperative agents

    Institute of Scientific and Technical Information of China (English)

    卢婉婷; 代明香; 薛方正

    2015-01-01

    This paper investigates a new formation motion problem of a class of first-order multi-agent systems with antagonis-tic interactions. A distributed formation control algorithm is proposed for each agent to realize the antagonistic formation motion. A sufficient condition is derived to ensure that all agents make an antagonistic formation motion in a distributed manner. It is shown that all agents can be spontaneously divided into several groups, and agents in the same group collab-orate while agents in different groups compete. Finally, a numerical simulation is included to demonstrate our theoretical results.

  7. Agent planning in AgScala

    Science.gov (United States)

    Tošić, Saša; Mitrović, Dejan; Ivanović, Mirjana

    2013-10-01

    Agent-oriented programming languages are designed to simplify the development of software agents, especially those that exhibit complex, intelligent behavior. This paper presents recent improvements of AgScala, an agent-oriented programming language based on Scala. AgScala includes declarative constructs for managing beliefs, actions and goals of intelligent agents. Combined with object-oriented and functional programming paradigms offered by Scala, it aims to be an efficient framework for developing both purely reactive, and more complex, deliberate agents. Instead of the Prolog back-end used initially, the new version of AgScala relies on Agent Planning Package, a more advanced system for automated planning and reasoning.

  8. A++: An Agent Oriented Programming Language

    Directory of Open Access Journals (Sweden)

    Deyi Xue

    2004-08-01

    Full Text Available A new Agent-Oriented Programming (AOP language called A++ is introduced in this research for developing agent-based distributed systems. In this work, agent-oriented programming is defined as a programming method with characteristics of distribution, autonomy, concurrency, and mobility. Both agents and objects can be modeled in A++. In addition to data and methods that can be defined in objects including classes and instances, each agent is also associated with an independent computing process in agent-oriented programming.

  9. Pharmacologic Agents for Chronic Diarrhea.

    Science.gov (United States)

    Lee, Kwang Jae

    2015-10-01

    Chronic diarrhea is usually associated with a number of non-infectious causes. When definitive treatment is unavailable, symptomatic drug therapy is indicated. Pharmacologic agents for chronic diarrhea include loperamide, 5-hydroxytryptamine type 3 (5-HT3) receptor antagonists, diosmectite, cholestyramine, probiotics, antispasmodics, rifaximin, and anti-inflammatory agents. Loperamide, a synthetic opiate agonist, decreases peristaltic activity and inhibits secretion, resulting in the reduction of fluid and electrolyte loss and an increase in stool consistency. Cholestyramine is a bile acid sequestrant that is generally considered as the first-line treatment for bile acid diarrhea. 5-HT3 receptor antagonists have significant benefits in patients with irritable bowel syndrome (IBS) with diarrhea. Ramosetron improves stool consistency as well as global IBS symptoms. Probiotics may have a role in the prevention of antibiotic-associated diarrhea. However, data on the role of probiotics in the treatment of chronic diarrhea are lacking. Diosmectite, an absorbent, can be used for the treatment of chronic functional diarrhea, radiation-induced diarrhea, and chemotherapy-induced diarrhea. Antispasmodics including alverine citrate, mebeverine, otilonium bromide, and pinaverium bromide are used for relieving diarrheal symptoms and abdominal pain. Rifaximin can be effective for chronic diarrhea associated with IBS and small intestinal bacterial overgrowth. Budesonide is effective in both lymphocytic colitis and collagenous colitis. The efficacy of mesalazine in microscopic colitis is weak or remains uncertain. Considering their mechanisms of action, these agents should be prescribed properly. PMID:26576135

  10. Multi-agent autonomous system

    Science.gov (United States)

    Fink, Wolfgang (Inventor); Dohm, James (Inventor); Tarbell, Mark A. (Inventor)

    2010-01-01

    A multi-agent autonomous system for exploration of hazardous or inaccessible locations. The multi-agent autonomous system includes simple surface-based agents or craft controlled by an airborne tracking and command system. The airborne tracking and command system includes an instrument suite used to image an operational area and any craft deployed within the operational area. The image data is used to identify the craft, targets for exploration, and obstacles in the operational area. The tracking and command system determines paths for the surface-based craft using the identified targets and obstacles and commands the craft using simple movement commands to move through the operational area to the targets while avoiding the obstacles. Each craft includes its own instrument suite to collect information about the operational area that is transmitted back to the tracking and command system. The tracking and command system may be further coupled to a satellite system to provide additional image information about the operational area and provide operational and location commands to the tracking and command system.

  11. An Agent Based Classification Model

    CERN Document Server

    Gu, Feng; Greensmith, Julie

    2009-01-01

    The major function of this model is to access the UCI Wisconsin Breast Can- cer data-set[1] and classify the data items into two categories, which are normal and anomalous. This kind of classifi cation can be referred as anomaly detection, which discriminates anomalous behaviour from normal behaviour in computer systems. One popular solution for anomaly detection is Artifi cial Immune Sys- tems (AIS). AIS are adaptive systems inspired by theoretical immunology and observed immune functions, principles and models which are applied to prob- lem solving. The Dendritic Cell Algorithm (DCA)[2] is an AIS algorithm that is developed specifi cally for anomaly detection. It has been successfully applied to intrusion detection in computer security. It is believed that agent-based mod- elling is an ideal approach for implementing AIS, as intelligent agents could be the perfect representations of immune entities in AIS. This model evaluates the feasibility of re-implementing the DCA in an agent-based simulation environ- ...

  12. 14th International Conference on Practical Applications of Agents and Multi-Agent Systems : Special Sessions

    CERN Document Server

    Escalona, María; Corchuelo, Rafael; Mathieu, Philippe; Vale, Zita; Campbell, Andrew; Rossi, Silvia; Adam, Emmanuel; Jiménez-López, María; Navarro, Elena; Moreno, María

    2016-01-01

    PAAMS, the International Conference on Practical Applications of Agents and Multi-Agent Systems is an evolution of the International Workshop on Practical Applications of Agents and Multi-Agent Systems. PAAMS is an international yearly tribune to present, to discuss, and to disseminate the latest developments and the most important outcomes related to real-world applications. It provides a unique opportunity to bring multi-disciplinary experts, academics and practitioners together to exchange their experience in the development of Agents and Multi-Agent Systems. This volume presents the papers that have been accepted for the 2016 in the special sessions: Agents Behaviours and Artificial Markets (ABAM); Advances on Demand Response and Renewable Energy Sources in Agent Based Smart Grids (ADRESS); Agents and Mobile Devices (AM); Agent Methodologies for Intelligent Robotics Applications (AMIRA); Learning, Agents and Formal Languages (LAFLang); Multi-Agent Systems and Ambient Intelligence (MASMAI); Web Mining and ...

  13. Borrelioses, agentes e vetores Borrelioses, agents and vectors: a review

    Directory of Open Access Journals (Sweden)

    Cleber O. Soares

    2000-03-01

    Full Text Available As borrelioses são enfermidades infecciosas determinadas por espiroquetas do gênero Borrelia, agentes transmissíveis, principalmente, por carrapatos aos animais e/ou ao homem. Nesta revisão são apresentadas e discutidas as enfermidades determinadas por borrélias, bem como as características gerais das espiroquetas, os aspectos relacionados a transmissão por artrópodes, as enfermidades nos animais domésticos e silvestres, quanto aos aspectos biológicos e patológicos, a doença de Lyme como principal zoonose do grupo, a associação de borrélia com outros agentes hematozoários e os métodos diagnósticos e a epidemiologia comparativa entre dados obtidos no Brasil com os de outros países. Estas borrelioses possuem características patológicas, clínicas e epidemiológicas variadas de acordo à região fisiográfica, devido à existência de distintas espécies, genoespécies e cepas; estes aspectos variam ainda em função dos artrópodes vetores, da interação vetor-patógeno e dos ecossistemas distintos.Borrelioses are infectous diseases caused by spirochaetes of the genus Borrelia. They are born mainly through ticks at animals and/or human beings. In this review are shown and discussed five groups of diseases determined by borrelia, general characteristics of the spirochaetes, aspects related to transmission by arthropods, biological and pathological aspects of the diseases in domestic and wild animals, Lyme disease as an important zoonosis, the association of borrelia with other hematozoa agents, the diagnostic methods and the comparative epidemiology with data obtained from Brazil and other countries. The borrelioses have pathological, clinical and epidemiological characteristics which vary according to physiographic regions due to the existence of different species, genospecies and strains of borrelia, of arthropod vectors, vector-agent relationship and of different ecocystems.

  14. Learning other agents` preferences in multiagent negotiation

    Energy Technology Data Exchange (ETDEWEB)

    Bui, H.H.; Kieronska, D.; Venkatesh, S. [Curtin Univ. of Technology, Perth, WA (Australia)

    1996-12-31

    In multiagent systems, an agent does not usually have complete information about the preferences and decision making processes of other agents. This might prevent the agents from making coordinated choices, purely due to their ignorance of what others want. This paper describes the integration of a learning module into a communication-intensive negotiating agent architecture. The learning module gives the agents the ability to learn about other agents` preferences via past interactions. Over time, the agents can incrementally update their models of other agents` preferences and use them to make better coordinated decisions. Combining both communication and learning, as two complement knowledge acquisition methods, helps to reduce the amount of communication needed on average, and is justified in situations where communication is computationally costly or simply not desirable (e.g. to preserve the individual privacy).

  15. Agent Communication Channel Based on BACnet

    Institute of Scientific and Technical Information of China (English)

    Jiang Wen-bin; Zhou Man-li

    2004-01-01

    We analyze the common shortcoming in the existing agent MTPs (message transport protocols). With employing the File object and related service AtomicWriteFile of BACnet (a data communication protocol building automation and control networks), a new method of agent message transport is proposed and implemented. Every agent platform (AP) has one specified File object and agents in another AP can communicate with agents in the AP by using AtomicWriteFile service. Agent messages can be in a variety of formats. In implementation, BACnet/IP and Ethernet are applied as the BACnet data link layers respectively. The experiment results show that the BACnet can provide perfect support for agent communication like other conventional protocols such as hypertext transfer protocol(HTTP), remote method invocation (RMI) etc. and has broken through the restriction of TCP/IP. By this approach, the agent technology is introduced into the building automation control network system.

  16. Analysis and Optimization for Mobile Agent Communication

    Institute of Scientific and Technical Information of China (English)

    YANGBo; LIUDayou

    2005-01-01

    Communication performance is one of the most important factors affecting the efficiency of mobile agent system. Only traditional optimization techniques for communication performance are not enough, especially in large-scale intelligent mobile agent system, so more intelligent optimization techniques are needed. In the background, the paper studies communication of mobile agent system from the viewpoint of performance. The paper makes qualitative and quantitative analysis of four important factors that will affect the communication performance of mobile agent system and presents the communication performance optimization model. The model hasthree primary functions. First, the model provides a formalism method to describe the communication task and process of mobile agent. Second, the model provides a means to make quantitative analysis of the performance of mobile agent system. Third, the model can plan out an optimal communication scheme for mobile agent to minimize the cost of whole communication. The model could thus be a building block for the optimization of the communication behavior of mobile agent.

  17. Comparison of Communication Models for Mobile Agents

    Directory of Open Access Journals (Sweden)

    Xining Li

    2003-04-01

    Full Text Available An agent is a self-contained process being acting on behalf of a user. A Mobile Agent is an agent roaming the internet to access data and services, and carry out its assigned task remotely. This paper will focus on the communication models for Mobile Agents. Generally speaking, communication models concern with problems of how to name Mobile Agents, how to establish communication relationships, how to trace moving agents, and how to guarantee reliable communication. Some existing MA systems are purely based on RPC-style communication, whereas some adopts asynchronous message passing, or event registration/handling. Different communication concepts suitable for Mobile Agents are well discussed in [1]. However, we will investigate these concepts and existing models from a different point view: how to track down agents and deliver messages in a dynamic, changing world.

  18. A Framework for Multi-Agent Planning

    OpenAIRE

    Bos, A; Tonino, J.F.M.; De Weerdt, M.M.; Witteveen, C.

    2000-01-01

    We introduce a computational framework, consisting of resources, skills, goals and services to represent the plans of individual agents and to develop models and algorithms for cooperation processes between a collection of agents.

  19. Porphyria Cutanea Tarda and Agent Orange

    Science.gov (United States)

    ... ZIP code here Porphyria Cutanea Tarda and Agent Orange VA presumes porphyria cutanea tarda (PCT) is related to Veterans' exposure to Agent Orange or other herbicides during military service when the ...

  20. Soft Tissue Sarcomas and Agent Orange

    Science.gov (United States)

    ... ZIP code here Soft Tissue Sarcomas and Agent Orange VA presumes some soft tissue sarcomas in Veterans are related to their exposure to Agent Orange or other herbicides during military service. The soft ...

  1. Retrotrapezoid nucleus, respiratory chemosensitivity and breathing automaticity

    Science.gov (United States)

    Guyenet, Patrice G.; Bayliss, Douglas A.; Stornetta, Ruth L.; Fortuna, Michal G.; Abbott, Stephen B.; Depuy, Seth D.

    2009-01-01

    SUMMARY Breathing automaticity and CO2 regulation are inseparable neural processes. The retrotrapezoid nucleus (RTN), a group of glutamatergic neurons that express the transcription factor Phox2b, may be a crucial nodal point through which breathing automaticity is regulated to maintain CO2 constant. This review updates the analysis presented in prior publications. Additional evidence that RTN neurons have central respiratory chemoreceptor properties is presented but this is only one of many factors that determine their activity. The RTN is also regulated by powerful inputs from the carotid bodies and, at least in the adult, by many other synaptic inputs. We also analyze how RTN neurons may control the activity of the downstream central respiratory pattern generator. Specifically, we review the evidence which suggests that RTN neurons a) innervate the entire ventral respiratory column, and b) control both inspiration and expiration. Finally, we argue that the RTN neurons are the adult form of the parafacial respiratory group in neonate rats. PMID:19712903

  2. Mobile agents for distributed decision support systems

    OpenAIRE

    Blaz Rodič

    2011-01-01

    This article focuses on the performance of Java based mobile agents using format translation via an intermediary XML based format. Our goal was to develop and verify the performance of a lightweight, mobile agent based solution that would allow strong security, portability and access to heterogeneous data resources from a mobile platform to facilitate exchange of data between simulation models and data resources. We have developed two types of agents: a mobile agent that functions as a server...

  3. Security Issues in Mobile Agent Paradigm

    OpenAIRE

    Nitin Jain; Neeraj Singla

    2011-01-01

    A mobile Agent is a Software program that migrates from node tonode of a heterogeneous network. They are goal-oriented i.e. workautonomously towards a goal, capable of suspending their executionon one platform and moving to other where they can resumeexecution using resources of these nodes and they meet and interactwith other agents. Agents may be stationary, always resident at asingle platform or mobile, capable of moving among differentplatforms at different time. The mobile agent paradigm...

  4. Explaining Simulations Through Self Explaining Agents

    OpenAIRE

    Maaike Harbers; John-Jules Meyer; Karel Van den Bosch

    2010-01-01

    Several strategies are used to explain emergent interaction patterns in agent-based simulations. A distinction can be made between simulations in which the agents just behave in a reactive way, and simulations involving agents with also pro-active (goal-directed) behavior. Pro-active behavior is more variable and harder to predict than reactive behavior, and therefore it might be harder to explain. However, the approach presented in this paper tries to make advantage of the agents' pro-active...

  5. ENZYMATIC DEINKING AGENTS FOR MIXED OFFICE WASTEPAPER

    Institute of Scientific and Technical Information of China (English)

    HuayuQiu; ChuanfuLiu; XiaokeMa; YingjuanFu

    2004-01-01

    This article focused on deinking agents for enzymatic deinking of MOW (mixed office wastepaper). The deinking performances of many series of surfactants were discussed at the experimental conditions, and finally some surfactants, which had good deinking effect, were selected. Then two-composed deinking agents were discussed. The deinkability of the deinking agents, e.g. deinking agents containing T-123 50% and P-10 50%, T-123 70% and O-15 30%, were better than that of the imported product.

  6. ENZYMATIC DEINKING AGENTS FOR MIXED OFFICE WASTEPAPER

    Institute of Scientific and Technical Information of China (English)

    Huayu Qiu; Chuanfu Liu; Xiaoke Ma; Yingjuan Fu

    2004-01-01

    This article focused on deinking agents for enzymatic deinking of MOW (mixed office wastepaper). The deinking performances of many series of surfactants were discussed at the experimental conditions, and finally, some surfactants, which had good deinking effect, were selected. Then two-composed deinking agents were discussed. The deinkability of the deinking agents, e.g. deinking agents containing T-123 50% and P-10 50%, T-123 70% and O-1530%, were better than that of the imported product.

  7. Virtual Knowledge Communities for Semantic Agents

    OpenAIRE

    Subercaze, Julien; Maret, Pierre

    2011-01-01

    International audience Virtual Knowledge Communities are a well suited paradigm for decentralized knowldege exchanges and they have been applied in several domains. In this paper we investigate the implementation of virtual knowledge communities with se- mantic agents. Using the SAM (Semantic Agent Modeling) approach, we show that agents can exchange community re- lated concepts (in OWL) and behavior (in SWRL). Agents can then learn and adapt new community-related behavior, which is useful...

  8. On Programming Organization-Aware Agents

    DEFF Research Database (Denmark)

    Jensen, Andreas Schmidt

    Since it is difficult (or even impossible) to assume anything about the agents’ behavior and goals in an open multi-agent system, it is often suggested that an organization is imposed upon the agents, whichhich, by abstracting away from the agents, specifies boundaries and objectives that the......-aware, thus removing the middleware and letting the agents directly reason about the organization. In this paper, we discuss the results so far, and describe the future goals and research direction for the project....

  9. Sports Agent Industry Emerges in China

    Institute of Scientific and Technical Information of China (English)

    HeiZiand; YiYou

    2003-01-01

    The agent profession is not new to Chinese. First appearing in the Western Zhou Dynasty, agents were called "Zhi Ren" then and "Ya Ren" from the Tang Dynasty onwards. In the Ming Dynasty, a certain amount of property and a license were required if one wanted to become an agent. In the late Qing Dynasty, Mai Ban (Chinese executives working in foreign firms), also a sort of agents, began to emerge in major cities of China.

  10. Integration of Agent System with Legacy Software

    Institute of Scientific and Technical Information of China (English)

    SHEN Qi; ZHAO Yan-hong; YIN Zhao-lin

    2003-01-01

    Agent technique is a new method that can analyze, design and realize a distributed open system. It has been used in almost every field. But if act for the real practical words in technique, it must integrate with legacy software, such as database system etc, and control them. This paper introduces the specification of agent software integration, ontology, instances database as implementing agent software integration with CORBA technique and takes XML, ACL as language communicating among agents.

  11. Topology and Social Behaviour of Agents

    OpenAIRE

    O. Hudak

    2003-01-01

    In a social group its members are caled here agents. Any two agents from the group may interact. The interaction consists of the exchange of information and it costs some energy. There exist subgroups of interacting agents which are nonreducibile. The structure, configuration of interactions between agents in the group, forms a macroscopic structure. The statistical equilibrium due to microreversibility is characterised by the maximum of entropy and by the minimum of energy, costs of informat...

  12. Self-Adapting Reactive Autonomous Agents

    Science.gov (United States)

    Andrecut, M.; Ali, M. K.

    This paper describes a new self-adapting control algorithm for reactive autonomous agents. The architecture of the autonomous agents integrates the reactive behavior with reinforcement learning. We show how these components perform on-line adaptation of the autonomous agents to various complex navigation situations by constructing an internal model of the environment. Also, a discussion on cooperation and coordination of teams of agents is presented.

  13. Properties of Ettringite Type Expansive Agent

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    By employing different forms and amounts of materials,many kinds of ettringite type expansive agents had been prepared.The relationship between the compositions and properties of expansive agents was analyzed.The design methods of expansive agent have been put forward according to the property requirement of expansive concrete.

  14. Agent for roentgenocontrast examination of cavities

    International Nuclear Information System (INIS)

    The water-soluble agent, additionaly containing starch, agar, water, is suggested to increase accuracy of injured cavity diagnostics. The method for roentgenocontrast agent preparation on the base of starch-agar gel is described. Advantages of the agent suggested in comparison with those of roentgenologic cavity investigation used are shown

  15. Cooperative heuristic multi-agent planning

    NARCIS (Netherlands)

    De Weerdt, M.M.; Tonino, J.F.M.; Witteveen, C.

    2001-01-01

    In this paper we will use the framework to study cooperative heuristic multi-agent planning. During the construction of their plans, the agents use a heuristic function inspired by the FF planner (l3l). At any time in the process of planning the agents may exchange available resources, or they may r

  16. Stability of Evolving Multi-Agent Systems

    CERN Document Server

    De Wilde, Philippe; 10.1109/TSMCB.2011.2110642

    2011-01-01

    A Multi-Agent System is a distributed system where the agents or nodes perform complex functions that cannot be written down in analytic form. Multi-Agent Systems are highly connected, and the information they contain is mostly stored in the connections. When agents update their state, they take into account the state of the other agents, and they have access to those states via the connections. There is also external, user-generated input into the Multi-Agent System. As so much information is stored in the connections, agents are often memory-less. This memory-less property, together with the randomness of the external input, has allowed us to model Multi-Agent Systems using Markov chains. In this paper, we look at Multi-Agent Systems that evolve, i.e. the number of agents varies according to the fitness of the individual agents. We extend our Markov chain model, and define stability. This is the start of a methodology to control Multi-Agent Systems. We then build upon this to construct an entropy-based defi...

  17. The Ontogenesis of Agent: Linguistic Expression.

    Science.gov (United States)

    Olswang, Lesley Barrett; Carpenter, Robert L.

    1982-01-01

    Some of the findings of a longitudinal study of three infants between their 11th and 22nd months to document development of linguistic expression of the agent concept indicated that first vocalizations were inconsistently associated with nonverbal agentive behaviors and later mature utterances coded agent-action-recipient events. (MC)

  18. Embedded Automation in Human-Agent Environment

    CERN Document Server

    Tweedale, Jeffrey W

    2012-01-01

    This research book proposes a general conceptual framework for the development of automation in human-agents environments that will allow human- agent teams to work effectively and efficiently. We examine various schemes to implement artificial intelligence techniques in agents.  The text is directed to the scientists, application engineers, professors and students of all disciplines, interested in the agency methodology and applications.

  19. STUDIES OF WATERBORNE AGENTS OF VIRAL GASTROENTERITIS

    Science.gov (United States)

    The etiologic agent of a large outbreak of waterborne viral gastroenteritis was detected employing immune electron microscopy (IEM) and a newly developed solid phase radioimmunoassay (RIA). This agent, referred to as the Snow Mountain Agent (SMA), is 27-32 nm. in diameter, has cu...

  20. A theoretical framework for explaining agent behavior

    NARCIS (Netherlands)

    Harbers, M.; Bosch, K. van den; Meyer, J.J.C.

    2011-01-01

    To understand emergent processes in multi-agent-based simulations it is important to study the global processes in a simulation as well as the processes on the agent level. The behavior of individual agents is easier to understand when they are able to explain their own behavior. In this paper, a th

  1. Stigmergy in multi-agent reinforcement learning

    OpenAIRE

    Aras, Raghav; Dutech, Alain; Charpillet, François

    2004-01-01

    http://www.computer.org In this paper, we describe how certain aspects of the biological phenomena of stigmergy can be imported into multi-agent reinforcement learning (MARL), with the purpose of better enabling coordination of agent actions and speeding up learning. In particular, we detail how these stigmergic aspects can be used to define an inter-agent communication framework.

  2. Explaining simulations through self explaining agents

    NARCIS (Netherlands)

    Harbers, M.; Bosch, K. van den; Meyer, J.J.C.

    2010-01-01

    Several strategies are used to explain emergent interaction patterns in agent-based simulations. A distinction can be made between simulations in which the agents just behave in a reactive way, and simulations involving agents with also pro-active (goal-directed) behavior. Pro-active behavior is mor

  3. Explaining Simulations through Self Explaining Agents

    NARCIS (Netherlands)

    Harbers, M.; Dignum, F.; Bosch, K. van den; Meyer, J.J.C.

    2008-01-01

    Several strategies are used to explain emergent interaction patterns in agent-based simulations. A distinction can be made between simulations in which the agents just behave in a reactive way, and simulations involving agents with also pro-active (goal-directed) behavior. Pro-active behavior is mor

  4. Mobile Agents in Networking and Distributed Computing

    CERN Document Server

    Cao, Jiannong

    2012-01-01

    The book focuses on mobile agents, which are computer programs that can autonomously migrate between network sites. This text introduces the concepts and principles of mobile agents, provides an overview of mobile agent technology, and focuses on applications in networking and distributed computing.

  5. On Programming Organization-Aware Agents

    DEFF Research Database (Denmark)

    Jensen, Andreas Schmidt

    2013-01-01

    Since it is difficult (or even impossible) to assume anything about the agents’ behavior and goals in an open multi-agent system, it is often suggested that an organization is imposed upon the agents, whichhich, by abstracting away from the agents, specifies boundaries and objectives that the age...

  6. Radioactive scanning agents with hydroquinone stabilizer

    International Nuclear Information System (INIS)

    Stable compositions useful as technetium 99m-based scintigraphic agents comprise hydroquinone in combination with a pertechnetate reducing agent or dissolved in pertechnetate-99m (sup(99m)TcOsub(4)sup(-)) solution. The compositions are especially useful in combination with a phosphate or phosphonate material which carries the radionuclide to bone, thus providing a skeletal imaging agent

  7. Honey - A Novel Antidiabetic Agent

    Directory of Open Access Journals (Sweden)

    Omotayo O. Erejuwa, Siti A. Sulaiman, Mohd S. Ab Wahab

    2012-01-01

    Full Text Available Diabetes mellitus remains a burden worldwide in spite of the availability of numerous antidiabetic drugs. Honey is a natural substance produced by bees from nectar. Several evidence-based health benefits have been ascribed to honey in the recent years. In this review article, we highlight findings which demonstrate the beneficial or potential effects of honey in the gastrointestinal tract (GIT, on the gut microbiota, in the liver, in the pancreas and how these effects could improve glycemic control and metabolic derangements. In healthy subjects or patients with impaired glucose tolerance or diabetes mellitus, various studies revealed that honey reduced blood glucose or was more tolerable than most common sugars or sweeteners. Pre-clinical studies provided more convincing evidence in support of honey as a potential antidiabetic agent than clinical studies did. The not-too-impressive clinical data could mainly be attributed to poor study designs or due to the fact that the clinical studies were preliminary. Based on the key constituents of honey, the possible mechanisms of action of antidiabetic effect of honey are proposed. The paper also highlights the potential impacts and future perspectives on the use of honey as an antidiabetic agent. It makes recommendations for further clinical studies on the potential antidiabetic effect of honey. This review provides insight on the potential use of honey, especially as a complementary agent, in the management of diabetes mellitus. Hence, it is very important to have well-designed, randomized controlled clinical trials that investigate the reproducibility (or otherwise of these experimental data in diabetic human subjects.

  8. Anticancer agents from marine sponges.

    Science.gov (United States)

    Ye, Jianjun; Zhou, Feng; Al-Kareef, Ammar M Q; Wang, Hong

    2015-01-01

    Marine sponges are currently one of the richest sources of anticancer active compounds found in the marine ecosystems. More than 5300 different known metabolites are from sponges and their associated microorganisms. To survive in the complicated marine environment, most of the sponge species have evolved chemical means to defend against predation. Such chemical adaptation produces many biologically active secondary metabolites including anticancer agents. This review highlights novel secondary metabolites in sponges which inhibited diverse cancer species in the recent 5 years. These natural products of marine sponges are categorized based on various chemical characteristics. PMID:25402340

  9. Social Robots as Persuasive Agents

    DEFF Research Database (Denmark)

    Vlachos, Evgenios; Schärfe, Henrik

    2014-01-01

    Robots are more and more used in a social context, and in this paper we try to formulate a research agenda concerning ethical issues around social HRI in order to be prepared for future scenarios where robots may be a naturally integrated part of human society. We outline different paradigms to d...... describe the role of social robots in communication processes with humans, and connect HRI with the topic of persuasive technology in health care, to critically reflect the potential benefits of using social robots as persuasive agents....

  10. Camouflaging Agents for Vitiligo Patients.

    Science.gov (United States)

    Hossain, Claudia; Porto, Dennis A; Hamzavi, Iltefat; Lim, Henry W

    2016-04-01

    Vitiligo is an acquired condition resulting in patches of depigmented skin that is cosmetically disfiguring and can subsequently be psychologically disturbing. For patients seeking to mask their vitiligo, camouflage options have historically been limited and been designated as a cosmetic, rather than a medical, concern. As research has indicated that proper concealment of vitiligo lesions can vastly improve quality of life, we believe it is essential that dermatologists become aware of all the options available to their patients and that discussions of camouflage options be broached from the first visit. Methods for concealment include cosmetic tattoos, dihydroxyacetone, general cosmetics, and various topical camouflage agents, including the newest product, Microskin™. We conducted a literature review of all of the available options for vitiligo concealment and evaluated their advantages and disadvantages. Ultimately, temporary methods of concealment are recommended; but the particular agent used can come from discussion with the patient based on the location of the lesions, degree of concealment desired, cost, and availability. PMID:27050692

  11. Surfactants as blackbird stressing agents

    Science.gov (United States)

    Lefebvre, P.W.; Seubert, J.L.

    1970-01-01

    Applications of wetting-agent solutions produce mortality in birds. The exact cause of death is undetermined but it is believed that destruction of the insulating qualities of the plumage permits ambient cold temperatures and evaporation to lower the body temperature to a lethal level. The original concept of using these materials as bird-control tools was developed in 1958 at the Patuxent Wildlife Research Center, Bureau of Sport Fisheries and Wildlife Laurel, Maryland. Early field trials by personnel of the Division of Wildlife Services and the Denver Wildlife Research Center indicated that ground-application techniques had promise but limitations of the equipment precluded successful large-scale roost treatments. In 1966, Patuxent Center personnel began using tanker-type aircraft to evaluate high-volume aerial applications of wetting agents. The success of these tests led to the use of small aircraft to make low-volume, high-concentration aerial applications just prior to expected rainfall. Recent trials of the low-volume method show that, with some limitations, it is effective, inexpensive, and safe to the environment. Current research emphasizes the screening of new candidate materials for efficacy, biodegradability, and toxicity to plants and non-target animals, as well as basic investigations of the avian physiological mechanisms involved. Field trials to develop more effective application techniques will continue.

  12. Electric power market agent design

    Science.gov (United States)

    Oh, Hyungseon

    The electric power industry in many countries has been restructured in the hope of a more economically efficient system. In the restructured system, traditional operating and planning tools based on true marginal cost do not perform well since information required is strictly confidential. For developing a new tool, it is necessary to understand offer behavior. The main objective of this study is to create a new tool for power system planning. For the purpose, this dissertation develops models for a market and market participants. A new model is developed in this work for explaining a supply-side offer curve, and several variables are introduced to characterize the curve. Demand is estimated using a neural network, and a numerical optimization process is used to determine the values of the variables that maximize the profit of the agent. The amount of data required for the optimization is chosen with the aid of nonlinear dynamics. To suggest an optimal demand-side bidding function, two optimization problems are constructed and solved for maximizing consumer satisfaction based on the properties of two different types of demands: price-based demand and must-be-served demand. Several different simulations are performed to test how an agent reacts in various situations. The offer behavior depends on locational benefit as well as the offer strategies of competitors.

  13. Cooperative planning in multi-agent systems

    OpenAIRE

    Torreño Lerma, Alejandro

    2016-01-01

    [EN] Automated planning is a centralized process in which a single planning entity, or agent, synthesizes a course of action, or plan, that satisfies a desired set of goals from an initial situation. A Multi-Agent System (MAS) is a distributed system where a group of autonomous agents pursue their own goals in a reactive, proactive and social way. Multi-Agent Planning (MAP) is a novel research field that emerges as the integration of automated planning in MAS. Agents are endowed with plan...

  14. Anchor Toolkit - a secure mobile agent system

    Energy Technology Data Exchange (ETDEWEB)

    Mudumbai, Srilekha S.; Johnston, William; Essiari, Abdelilah

    1999-05-19

    Mobile agent technology facilitates intelligent operation insoftware systems with less human interaction. Major challenge todeployment of mobile agents include secure transmission of agents andpreventing unauthorized access to resources between interacting systems,as either hosts, or agents, or both can act maliciously. The Anchortoolkit, designed by LBNL, handles the transmission and secure managementof mobile agents in a heterogeneous distributed computing environment. Itprovides users with the option of incorporating their security managers.This paper concentrates on the architecture, features, access control anddeployment of Anchor toolkit. Application of this toolkit in a securedistributed CVS environment is discussed as a case study.

  15. An Agent-Based Distributed Manufacturing System

    Institute of Scientific and Technical Information of China (English)

    J.Li; J.Y.H.Fuh; Y.F.Zhang; A.Y.C.Nee

    2006-01-01

    Agent theories have shown their promising capability in solving distributed complex system ever since its development. In this paper, one multi-agent based distributed product design and manufacturing planning system is presented. The objective of the research is to develop a distributed collaborative design environment for supporting cooperation among the existing engineering functions. In the system, the functional agents for design, manufacturability evaluation,process planning and scheduling are efficiently integrated with a facilitator agent. This paper firstly gives an introduction to the system structure, and the definitions for each executive agent are then described and a prototype of the proposed is also included at the end part.

  16. Selected Problems on Mobile Agent Communication

    OpenAIRE

    Yinka A. Adekunle; Sola S. Maitanmi

    2011-01-01

    Mobile agent technology offers a new computing paradigm in which a program, in the form of a software agent, can transfer its execution from agent to agent masquerading itself as the original source of message. The use of mobile code has a long history dating back to the use of remote job entry systems in the 1960's. Today's agent incarnations can be characterized in a number of ways ranging from simple distributed objects to highly secured software with algorithm that can only be interpreted...

  17. Reversal agents in anaesthesia and critical care

    Directory of Open Access Journals (Sweden)

    Nibedita Pani

    2015-01-01

    Full Text Available Despite the advent of short and ultra-short acting drugs, an in-depth knowledge of the reversal agents used is a necessity for any anaesthesiologist. Reversal agents are defined as any drug used to reverse the effects of anaesthetics, narcotics or potentially toxic agents. The controversy on the routine reversal of neuromuscular blockade still exists. The advent of newer reversal agents like sugammadex have made the use of steroidal neuromuscular blockers like rocuronium feasible in rapid sequence induction situations. We made a review of the older reversal agents and those still under investigation for drugs that are regularly used in our anaesthesia practice.

  18. 75 FR 56489 - Separation Distances of Ammonium Nitrate and Blasting Agents From Explosives or Blasting Agents...

    Science.gov (United States)

    2010-09-16

    ... Ammonium Nitrate and Blasting Agents From Explosives or Blasting Agents (2002R-226P) AGENCY: Bureau of... CFR 555.220 set forth a table of separation distances of ammonium nitrate and blasting agents from explosives or blasting agents followed by six explanatory notes. Note three (3) states that the...

  19. Intelligent agent support for automated radiology exam

    Science.gov (United States)

    Shang, Yi; Popescu, Mihail

    2000-10-01

    A difficult problem in automatic medical image understanding is that for every image type such as x-ray and every body organ such as heart, there exist specific solutions that do not allow for generalization. Just collecting all the specific solutions will not achieve the vision of a computerized physician. To address this problem, we propose an intelligent agent approach that is based on agent-oriented programming is that it combines the benefits of object-oriented programming and expert system. For radiology image understanding, we present a multi- agent system that is composed of two major types of intelligent agents: radiologist agents and patient agents. A patient agent asks for multiple opinions from radiologists agents in interpreting a given set of images and then integrates the opinions. A radiologist agent decomposes the image recognition task into smaller problems that are solved collectively by multiple intelligent sub-agents. Finally, we present a preliminary implementation and running examples of the multi-agent system.

  20. A SURVEY OF THE PROPERTIES OF AGENTS

    Directory of Open Access Journals (Sweden)

    Kornelije Rabuzin

    2006-06-01

    Full Text Available In the past decade agent systems were considered to be as one of the major fields of study in Artificial Intelligence (AI field. Many different definitions of agents were presented and several different approaches describing agency can be distinguished. While some authors have tried to define “what” an agent really is, others have tried to identify agents by means of properties which they should possess. Most authors agree on these properties (at least basic set of properties which are intrinsic to agents. Since agent's definitions are not consistent, we are going to give an overview and list the properties intrinsic to an agent. Many different adjectives were attached to the term agent as well and many different kinds of agents and different architectures emerged too. The aim of this paper it go give an overview of what was going on in the field while taking into consideration main streams and projects. We will also present some guidelines important when modelling agent systems and say something about security issues. Also, some existing problems which restrict the wider usage of agents will be mentioned too.

  1. Agent-Based Modeling and Mapping of Manufacturing System

    Institute of Scientific and Technical Information of China (English)

    Z; Zhang

    2002-01-01

    Considering the agent-based modeling and mapping i n manufacturing system, some system models are described in this paper, which are included: Domain Based Hierarchical Structure (DBHS), Cascading Agent Structure (CAS), Proximity Relation Structure (PRS), and Bus-based Network Structure (BNS ). In DBHS, one sort of agents, called static agents, individually acts as Domai n Agents, Resources Agents, UserInterface Agents and Gateway Agents. And the oth ers, named mobile agents, are the brokers of task and ...

  2. Mobile agents for distributed decision support systems

    Directory of Open Access Journals (Sweden)

    Blaz Rodič

    2011-03-01

    Full Text Available This article focuses on the performance of Java based mobile agents using format translation via an intermediary XML based format. Our goal was to develop and verify the performance of a lightweight, mobile agent based solution that would allow strong security, portability and access to heterogeneous data resources from a mobile platform to facilitate exchange of data between simulation models and data resources. We have developed two types of agents: a mobile agent that functions as a server for queries in SQL and converts the query results into XML documents and a stationary agent acting as a client for query forwarding and conversion of received documents into text files readable by a client application. We have tested the performance of the agents in a distributed simulation scenario and established that the agents can be used to connect heterogeneous simulation models and other applications, improving their connectivity and usability.

  3. Agent-Oriented Probabilistic Logic Programming

    Institute of Scientific and Technical Information of China (English)

    Jie Wang; Shi-Er Ju; Chun-Nian Liu

    2006-01-01

    Currently, agent-based computing is an active research area, and great efforts have been made towards the agent-oriented programming both from a theoretical and practical view. However, most of them assume that there is no uncertainty in agents' mental state and their environment. In other words, under this assumption agent developers are just allowed to specify how his agent acts when the agent is 100% sure about what is true/false. In this paper, this unrealistic assumption is removed and a new agent-oriented probabilistic logic programming language is proposed, which can deal with uncertain information about the world. The programming language is based on a combination of features of probabilistic logic programming and imperative programming.

  4. Knowledge Management in Role Based Agents

    Science.gov (United States)

    Kır, Hüseyin; Ekinci, Erdem Eser; Dikenelli, Oguz

    In multi-agent system literature, the role concept is getting increasingly researched to provide an abstraction to scope beliefs, norms, goals of agents and to shape relationships of the agents in the organization. In this research, we propose a knowledgebase architecture to increase applicability of roles in MAS domain by drawing inspiration from the self concept in the role theory of sociology. The proposed knowledgebase architecture has granulated structure that is dynamically organized according to the agent's identification in a social environment. Thanks to this dynamic structure, agents are enabled to work on consistent knowledge in spite of inevitable conflicts between roles and the agent. The knowledgebase architecture is also implemented and incorporated into the SEAGENT multi-agent system development framework.

  5. An Agent Framework of Tourism Recommender System

    Directory of Open Access Journals (Sweden)

    Jia Zhi Yang

    2016-01-01

    Full Text Available This paper proposes the development of an Agent framework for tourism recommender system. The recommender system can be featured as an online web application which is capable of generating a personalized list of preference attractions for tourists. Traditional technologies of classical recommender system application domains, such as collaborative filtering, content-based filtering and content-based filtering are effectively adopted in the framework. In the framework they are constructed as Agents that can generate recommendations respectively. Recommender Agent can generate recommender information by integrating the recommendations of Content-based Agent, collaborative filtering-based Agent and constraint-based Agent. In order to make the performance more effective, linear combination method of data fusion is applied. User interface is provided by the tourist Agent in form of webpages and mobile app.

  6. G-CSF: From granulopoietic stimulant to bone marrow stem cell mobilizing agent.

    Science.gov (United States)

    Bendall, Linda J; Bradstock, Kenneth F

    2014-08-01

    G-CSF was among the first cytokines to be identified and rapidly transitioned into clinical medicine. Initially used to promote the production of neutrophils in patients with chemotherapy-induced neutropenia it helped to revolutionize the delivery of cancer therapy. Its ability to mobilize hematopoietic stem cells from the bone marrow into the blood was subsequently exploited, changing the face of hematopoietic stem cell transplantation. Today the knowledge gained in unraveling the mechanisms of stem cell mobilization by G-CSF is being explored as a means to increase chemosensitivity in hematological malignancies. This review provides a brief history of G-CSF and then focuses on recent advances in our understanding of G-CSF-induced stem cell mobilization and the potential clinical application of this knowledge in chemo-sensitization. PMID:25131807

  7. 10th International Conference on Practical Applications of Agents and Multi-Agent Systems

    CERN Document Server

    Pérez, Javier; Golinska, Paulina; Giroux, Sylvain; Corchuelo, Rafael; Trends in Practical Applications of Agents and Multiagent Systems

    2012-01-01

    PAAMS, the International Conference on Practical Applications of Agents and Multi-Agent Systems is an evolution of the International Workshop on Practical Applications of Agents and Multi-Agent Systems. PAAMS is an international yearly tribune to present, to discuss, and to disseminate the latest developments and the most important outcomes related to real-world applications. It provides a unique opportunity to bring multi-disciplinary experts, academics and practitioners together to exchange their experience in the development of Agents and Multi-Agent Systems.   This volume presents the papers that have been accepted for the 2012 in the workshops: Workshop on Agents for Ambient Assisted Living, Workshop on Agent-Based Solutions for Manufacturing and Supply Chain and Workshop on Agents and Multi-agent systems for Enterprise Integration.

  8. Interaction Protocols in Multi-Agent Systems based on Agent Petri Nets Model

    Directory of Open Access Journals (Sweden)

    Kamel Barkaoui

    2013-08-01

    Full Text Available This paper deals with the modeling of interaction between agents in Multi Agents System (MAS based on Agent Petri Nets (APN. Our models are created based on communicating agents. Indeed, an agent initiating a conversation with other can specify the interaction protocol wishes to follow. The combination of APN and FIPA Protocols schemes leads to a set of deployment formal rules for points where model interaction can be successfully implemented. We introduce some models FIPA standard protocols.

  9. Fault Tolerance Mobile Agent System Using Witness Agent in 2-Dimensional Mesh Network

    Directory of Open Access Journals (Sweden)

    Ahmad Rostami

    2010-09-01

    Full Text Available Mobile agents are computer programs that act autonomously on behalf of a user or its owner and travel through a network of heterogeneous machines. Fault tolerance is important in their itinerary. In this paper, existent methods of fault tolerance in mobile agents are described which they are considered in linear network topology. In the methods three agents are used to fault tolerance by cooperating to each others for detecting and recovering server and agent failure. Three types of agents are: actual agent which performs programs for its owner, witness agent which monitors the actual agent and the witness agent after itself, probe which is sent for recovery the actual agent or the witness agent on the side of the witness agent. Communication mechanism in the methods is message passing between these agents. The methods are considered in linear network. We introduce our witness agent approach for fault tolerance mobile agent systems in Two Dimensional Mesh (2D-Mesh Network. Indeed Our approach minimizes Witness-Dependency in this network and then represents its algorithm.

  10. Agent Based Individual Traffic guidance

    DEFF Research Database (Denmark)

    Wanscher, Jørgen Bundgaard

    2004-01-01

    vehicle can be obtained through cellular phone tracking or GPS systems. This information can then be used to provide individual traffic guidance as opposed to the mass information systems of today -- dynamic roadsigns and trafficradio. The goal is to achieve better usage of road and time. The main topic......When working with traffic planning or guidance it is common practice to view the vehicles as a combined mass. >From this models are employed to specify the vehicle supply and demand for each region. As the models are complex and the calculations are equally demanding the regions and the detail of...... the road network is aggregated. As a result the calculations reveal only what the mass of vehicles are doing and not what a single vehicle is doing. This is the crucial difference to ABIT (Agent Based Individual Trafficguidance). ABIT is based on the fact that information on the destination of each...

  11. Bioprotective agents in safety control

    Directory of Open Access Journals (Sweden)

    Dimitrijević-Branković Suzana I.

    2003-01-01

    Full Text Available Food poisoning is the one of the main health hazards even today. More than 200 known diseases are transmitted through food. The causes of foodborne illness include viruses, bacteria, parasites, toxins, metals, and prions and the symptoms of foodborne illness range from mild gastroenteritis to life-threatening neurological, hepatic and renal syndromes.The prevention of food poisonings represents very serious task for food manufacturers. Beside food control according to the concept "from the farm to the table" there is increased need for the development of new technology for longer shelf lifes of food. Food fermented by lactic acid bacteria (LAB and traditionally considered to be safe. There are many substances produced by LAB that affect the shelf life of fermented food, by active suppression of poisoning microorganisms growth. Because of that, the LAB is recently considered as bioprotective agents that have important role in food safety.

  12. [Anticonvulsant agents in neuralgic pain.].

    Science.gov (United States)

    Jurna, I; Zenz, M

    1992-06-01

    The anticonvulsants, carbamazepine, clonazepam, phenytoin, and valproic acid are capable of depressing attacks of shooting pain in neuralgia. Shooting pain is perceived in trigeminal, intercostal, and other neuralgias, as a consequence of infectious diseases such as herpes zoster, and in the course of polyneuropathies of various causes. It is due to injury of nociceptive afferents, which generate bursts of activity in response to appropriate environmental changes. The anticonvulsant agents have no analgesic property per se, so that background pain remains unchanged. The depression of shooting pain results from the anticonvulsant action of the compounds. Both carbamazepine and phenytoin block synaptic transmission of neuronal hyperactivity by a direct depressant action that includes reduction of sodium conductance and by activation of inhibitory control. Clonazepam and valproic acid act by enhancing GABA-mediated inhibition of synaptic transmission. Carbamazepine is by far the most widely used compound; phenytoin, clonazepam, and valproic acid are not so popular because of their side effects. PMID:18415623

  13. Host modulation by therapeutic agents

    Directory of Open Access Journals (Sweden)

    Sugumari Elavarasu

    2012-01-01

    Full Text Available Periodontal disease susceptible group present advanced periodontal breakdown even though they achieve a high standard of oral hygiene. Various destructive enzymes and inflammatory mediators are involved in destruction. These are elevated in case of periodontal destruction. Host modulation aims at bringing these enzymes and mediators to normal level. Doxycycline, nonsteroidal anti-inflammatory drugs (NSAIDs, bisphosphonates, nitrous oxide (NO synthase inhibitors, recombinant human interleukin-11 (rhIL-11, omega-3 fatty acid, mouse anti-human interleukin-6 receptor antibody (MRA, mitogen-activated protein kinase (MAPK inhibitors, nuclear factor-kappa B (NF-kb inhibitors, osteoprotegerin, and tumor necrosis factor antagonist (TNF-α are some of the therapeutic agents that have host modulation properties.

  14. Evolutionary algorithms and multi-agent systems

    Science.gov (United States)

    Oh, Jae C.

    2006-05-01

    This paper discusses how evolutionary algorithms are related to multi-agent systems and the possibility of military applications using the two disciplines. In particular, we present a game theoretic model for multi-agent resource distribution and allocation where agents in the environment must help each other to survive. Each agent maintains a set of variables representing actual friendship and perceived friendship. The model directly addresses problems in reputation management schemes in multi-agent systems and Peer-to-Peer distributed systems. We present algorithms based on evolutionary game process for maintaining the friendship values as well as a utility equation used in each agent's decision making. For an application problem, we adapted our formal model to the military coalition support problem in peace-keeping missions. Simulation results show that efficient resource allocation and sharing with minimum communication cost is achieved without centralized control.

  15. Diuretic Agents in Treatment of Sudden Deafness

    Institute of Scientific and Technical Information of China (English)

    JI Chang-you; LI Hong-tao; ZHOU Ding-rong; CHEN Ji-chuan; WANG Yi-nan; GUAN Li-qian; ZHANG Min

    2008-01-01

    Objective To study the role of diuretic agents in treating sudden deafness (SD) and explore the possibility of endolymphatic hydrops as a potential cause of SD. Methods Twenty-eight SD cases were reviewed. In 23 cases, treatment was initiated with routine agents. Diuretic agents were later added in 8 of these cases that failed to respond to routine treatment agents. Diuretic agents were included in the initial treatment in the rest 5 cases. In total, 13 cases received diuretics in addition to routine treatment agents and 15 cases received conventional treatment only. Results In the 8 cases who received diuretics after failed conventional treatments, 4 showed hearing improvement, whereas all 5 cases in which diuretics were included in the initial treatment demonstrated hearing improvement. Conclusion These results suggest a possible role of endolymphatic hydrops in the pathophysiologic course of SD. Diuretics should be considered when clear indications exist with no conflicts to other medical conditions.

  16. Ultrasound contrast agents: bubbles, drops and particles

    OpenAIRE

    Lajoinie, Guillaume Pierre René

    2015-01-01

    The research on the medical use of microbubbles has coontinuously provided fascinating results for half a century. Investigating new agents or new uses of existing agents requires both innovative physics and ideas and extensive testing in-vitro and in vivo. The translation from the lab to the clinic is long and calls upon many specialties. In this dissertation, we have presented and studied various experimental agents for biomedical imaging and therapy, some in the early development phase and...

  17. NESTA: NASA Engineering Shuttle Telemetry Agent

    OpenAIRE

    Semmel, Glenn S.; Davis, Steven R.; Leucht, Kurt W.; Rowe, Dan A.; Smith, Kevin E.; O'Farrel, Ryan l; Boloni, Ladislau

    2006-01-01

    The Electrical Systems Division at the NASA Kennedy Space Center has developed and deployed an agent-based tool to monitor the space shuttle's ground processing telemetry stream. The application, the NASA Engineering Shuttle Telemetry Agent (NESTA), increases situational awareness for system and hardware engineers during ground processing of the shuttle's subsystems. The agent provides autonomous monitoring of the telemetry stream and automatically alerts system engineers when predefined crit...

  18. Intelligent Agents in E-Commerce

    Directory of Open Access Journals (Sweden)

    Valentin LITOIU

    2006-01-01

    Full Text Available This paper emphasizes the importance of intelligent agents in e-commerce, with a particular focus on the B2C and B2B context. From the consumer buying behaviour perspective, agents can be used to assist the following stages: need identification, product brokering, buyer coalition formation, merchant brokering and negotiation. Related to B2B commerce, intelligent agents are involved in partnership formation, brokering and negotiation.

  19. Web-Based Computing Resource Agent Publishing

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Web-based Computing Resource Publishing is a efficient way to provide additional computing capacity for users who need more computing resources than that they themselves could afford by making use of idle computing resources in the Web.Extensibility and reliability are crucial for agent publishing. The parent-child agent framework and primary-slave agent framework were proposed respectively and discussed in detail.

  20. Modeling culture in intelligent virtual agents

    OpenAIRE

    Mascarenhas, S.; Degens, N.; Paiva, A; Prada, R.; Hofstede, G.J.; Beulens, A.J.M.; Aylett, R.

    2015-01-01

    This work addresses the challenge of creating virtual agents that are able to portray culturally appropriate behavior when interacting with other agents or humans. Because culture influences how people perceive their social reality it is important to have agent models that explicitly consider social elements, such as existing relational factors. We addressed this necessity by integrating culture into a novel model for simulating human social behavior. With this model, we operationalized a par...

  1. Intelligent Agents in E-Commerce

    OpenAIRE

    Valentin LITOIU; Amelia BADICA; Cristian ETEGAN

    2006-01-01

    This paper emphasizes the importance of intelligent agents in e-commerce, with a particular focus on the B2C and B2B context. From the consumer buying behaviour perspective, agents can be used to assist the following stages: need identification, product brokering, buyer coalition formation, merchant brokering and negotiation. Related to B2B commerce, intelligent agents are involved in partnership formation, brokering and negotiation.

  2. Massive Multi-Agent Systems Control

    Science.gov (United States)

    Campagne, Jean-Charles; Gardon, Alain; Collomb, Etienne; Nishida, Toyoaki

    2004-01-01

    In order to build massive multi-agent systems, considered as complex and dynamic systems, one needs a method to analyze and control the system. We suggest an approach using morphology to represent and control the state of large organizations composed of a great number of light software agents. Morphology is understood as representing the state of the multi-agent system as shapes in an abstract geometrical space, this notion is close to the notion of phase space in physics.

  3. Applying Software Engineering to Agent Development

    OpenAIRE

    Cohen, Mark A.; Lock Haven University; RITTER, Frank E.; Haynes, Steven R

    2010-01-01

    Developing intelligent agents and cognitive models is a complex software engineering activity. This article shows how all intelligent agent creation tools can be improved by taking advantage of established software engineering principles such as high-level languages, maintenance-oriented development environments, and software reuse. We describe how these principles have been realized in the Herbal integrated development environment, a collection of tools that allows agent developers to exploi...

  4. Agent-based argumentation for ontology alignments

    OpenAIRE

    Laera, Loredana; Tamma, Valentina; Bench-Capon, Trevor; Euzenat, Jérôme

    2006-01-01

    laera2006a International audience When agents communicate they do not necessarily use the same vocabulary or ontology. For them to interact successfully they must find correspondences between the terms used in their ontologies. While many proposals for matching two agent ontologies have been presented in the literature, the resulting alignment may not be satisfactory to both agents and can become the object of further negotiation between them. This paper describes our work constructing ...

  5. Decentralized network management based on mobile agent

    Institute of Scientific and Technical Information of China (English)

    李锋; 冯珊

    2004-01-01

    The mobile agent technology can be employed effectively for the decentralized management of complex networks. We show how the integration of mobile agent with legacy management protocol, such as simple network management protocol (SNMP), leads to decentralized management architecture. HostWatcher is a framework that allows mobile agents to roam network, collect and process data, and perform certain adaptive actions. A prototype system is built and a quantitative analysis underlines the benefits in respect to reducing network load.

  6. Agent fabrication and its implementation for agent-based electronic commerce

    OpenAIRE

    Guan, Su; Zhu, F.

    2002-01-01

    In the last decade, agent-based e-commerce has emerged as a potential role for the next generation of e-commerce. How to create agents for e-commerce applications has become a serious consideration in this field. This paper proposes a new scheme named agent fabrication and elaborates its implementation in multi-agent systems based on the SAFER (Secure Agent Fabrication, Evolution & Roaming) architecture. First, a conceptual structure is proposed for software agents carrying out e-commerce act...

  7. Glaucoma: role of neuroprotective agents

    Directory of Open Access Journals (Sweden)

    Achyut N. Pandey

    2014-10-01

    Full Text Available Glaucoma is an optic neuropathy, considered as the second leading cause of blindness worldwide. Glaucoma is characterized by selective death of retinal ganglion cells (RGC and a progressive loss of vision. Elevated intraocular pressure (IOP is one of the most important risk factors for developing glaucoma and hence we mainly focus on lowering IOP to arrest the progression of glaucoma. However, many patients continue to demonstrate a clinically downhill course despite the control of initially raised IOP. In fact, some patients develop what is called normal tension glaucoma, not associated to an increased IOP. This emphasizes that several pressure-independent mechanisms are responsible for the development and progression of glaucomatous neuropathy and that high IOP and vascular insufficiency in the optic nerve head are only risk factors for the development of glaucoma, and are not the only target for the treatment of glaucoma. The reason is that the process of RGC death is thought to be biphasic, and the primary injury is followed by a slower secondary degeneration related to a noxious environment surrounding the apoptotic cells. This environment is characterized by changes in the extra-cellular ionic concentrations, increased amounts of free radicals, neurotrophins (NT depletion and increased glutamate-induced excitotoxicity due to high extra-cellular glutamate levels, which binds to N-methyl-D-aspartate (NMDA receptors leading to an abnormally high intracellular Ca2+ concentration. Neuroprotection is a process that attempts to preserve the remaining cells that are still vulnerable to damage, and the main aim of neuroprotective therapy is to employ pharmacologic or other means to attenuate the hostility of the environment surrounding the degenerating cells, or to supply the cells with the tools to deal with this aggression, providing resilience to the insult. Several agents have been reported neuroprotective in glaucoma, both in clinical assays

  8. Multi-agent systems simulation and applications

    CERN Document Server

    Uhrmacher, Adelinde M

    2009-01-01

    Methodological Guidelines for Modeling and Developing MAS-Based SimulationsThe intersection of agents, modeling, simulation, and application domains has been the subject of active research for over two decades. Although agents and simulation have been used effectively in a variety of application domains, much of the supporting research remains scattered in the literature, too often leaving scientists to develop multi-agent system (MAS) models and simulations from scratch. Multi-Agent Systems: Simulation and Applications provides an overdue review of the wide ranging facets of MAS simulation, i

  9. TEST SUITE GENERATION PROCESS FOR AGENT TESTING

    Directory of Open Access Journals (Sweden)

    HOUHAMDI ZINA

    2011-04-01

    Full Text Available Software agents are a promising technology for today's complex, distributed systems. Methodologies and techniques that address testing and reliability of multi agent systems are increasingly demanded, in particular to support automated test case generation and execution. In this paper, we introduce a novel approach for goal-oriented software agent testing. It specifies a testing process that complements the goal oriented methodology Tropos and reinforces the mutual relationship between goal analysis and testing. Furthermore, it defines a structured and comprehensive agent test suite generation process by providing a systematic way of deriving test cases from goal analysis.

  10. Integrating Interaction Framework for Agent Negotiation

    Institute of Scientific and Technical Information of China (English)

    肖正光; 王振杰; 徐良贤

    2003-01-01

    Agent negotiation has become increasingly important since the advent of electronic commerce.There are two kinds of interactions in the process of agent negotiation.One is the interaction between different agents,and the other is the interaction between the agent and the human user.In this paper,firstly,we introduce Q language,a scenario description language for designing interactions between agents and human users.Then we propose an integrating interaction framework for agent negotiation,in which both kinds of interactions are described by Q scenario.Our framework can make the interaction process open and easy to be understood by the users.Users can understand how the negotiation process goes and what is happening in the system including some erroneous or inappropriate actions caused by the negotiation agent.This gives the users a chance to terminate or change the behavior of negotiation agent in time to avoid unfavorable negotiation outcome.In addition,users can customize the agent's behaviors through visible interactions with it.

  11. Agent architecture for intelligent manufacturing systems

    Directory of Open Access Journals (Sweden)

    J. Madejski

    2008-08-01

    Full Text Available Purpose: Analysis is made of requirements posed by tasks of agents operating in the intelligent manufacturing systems and their resulting architecture is presented.Design/methodology/approach: Architecture of agent systems for industrial environment is presented, making it possible to generate the particular agents customised for the specific tasks, based on the automatic analysis of its required features.Findings: Extension of cellular automata approach underlying the conventional agent behaviour specification using the Fuzzy Cognitive Maps is presented in conjunction with the neural networks providing learning capability of the agents designed for the various levels of the manufacturing supervisory and execution systems. Adding reaction time specification to FCM makes it possible to analyse and design systems with the required behaviour.Research limitations/implications: Specific features of the designed agent architecture have been tested as separate mechanisms which can be merged into the final comprehensive at a later stage.Originality/value: Agent architecture is proposed for the industrial applications of single agents and their groups that can collaborate to achieve the individual and joint goals specified in reaction to changing environment conditions and into their agendas in XML format. Automatic generation of custom agent reactions models can be carried out based on a set of requirements that may be specified in the if-then rules form.

  12. Agent-Based Health Monitoring System Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose combination of software intelligent agents to achieve decentralized reasoning, with fault detection and diagnosis using PCA, neural nets, and maximum...

  13. Decidability Classes for Mobile Agents Computing

    CERN Document Server

    Fraigniaud, Pierre

    2010-01-01

    We establish a classification of decision problems that are to be solved by mobile agents operating in unlabeled graphs, using a deterministic protocol. The classification is with respect to the ability of a team of agents to solve the problem, possibly with the aid of additional information. In particular, our focus is on studying differences between the decidability of a decision problem by agents and its verifiability when a certificate for a positive answer is provided to the agents. We show that the class MAV of mobile agents verifiable problems is much wider than the class MAD of mobile agents decidable problems. Our main result shows that there exist natural MAV-complete problems: the most difficult problems in this class, to which all problems in MAV are reducible. Our construction of a MAV-complete problem involves two main ingredients in mobile agents computability: the topology of the quotient graph and the number of operating agents. Beyond the class MAV we show that, for a single agent, three nat...

  14. Application Framework with Abstractions for Protocol and Agent Role

    DEFF Research Database (Denmark)

    Kristensen, Bent Bruun

    2016-01-01

    In multi-agent systems, agents interact by sending and receiving messages and the actual sequences of message form interaction structures between agents. Protocols and agents organized internally by agent roles support these interaction structures. Description and use of protocols based on agent...

  15. Licopeno como agente antioxidante Lycopene as an antioxidant agent

    Directory of Open Access Journals (Sweden)

    Najua Juma Ismail Esh Shami

    2004-06-01

    Full Text Available Este trabalho constitui uma revisão de dados científicos sobre o consumo de licopeno e sua ação como fator antioxidante. O licopeno é considerado o carotenóide que possui a maior capacidade seqüestrante do oxigênio singlete. Radicais livres agem continuamente no organismo, podendo desencadear danos celulares e serem os responsáveis pelo desenvolvimento de câncer e certas doenças crônicas. Estudos mostram que o licopeno protege moléculas de lipídios, lipoproteínas de baixa densidade, proteínas e DNA contra o ataque dos radicais, tendo um papel essencial na proteção de doenças. Como prevenção, preconiza-se o consumo de dietas ricas em alimentos fontes de licopeno: tomates e seus produtos (purê, pasta, catchup, mamão, pitanga e goiaba; que aportem cerca de 35mg de licopeno ao dia.This paper is a review of scientific data about lycopene as an antioxidant agent. Lycopene is considered the carotenoid that has the highest capacity of capturing the singlet oxygen. Free radicals are continuously acting on the organism, being capable of promoting cellular damage and development of cancer among other chronic diseases. Studies show that lycopene protects lipid molecules, low-density lipoproteins, proteins and DNA against the attack of free radicals. They have an essential function in the protection against diseases. As a precaution, one should eat foods that are a source of lycopene: tomatoes and tomato-products (purée, pasta, ketchup, papaya, pitanga and guava; to provide approximately 35mg of lycopene a day.

  16. Cutting agents for special metals

    International Nuclear Information System (INIS)

    The quantity of use of special metals has increased year after year in the Plasma Research Institute, Nagoya University, with the development of researches on plasma and nuclear fusion. Most of these special metals are hard to cut, and in order to secure the surface smoothness and dimensional accuracy, considerable efforts are required. The method of experiment is as follows: cutting agents salt water and acetone, rape-seed oil, sulfide and chloride oil and water soluble cutting oil W grade 3; metals to be cut niobium, molybdenum, tantalum, titanium and tungsten; cutting conditions cutting speed 4.7 to 90 m/min, feed 0.07 to 0.2 mm/rev, depth of cut 0.1 to 0.4 mm, tool cemented carbide bit. Chemicals such as tetrachloromethane and trichloroethane give excellent cutting performance, but the toxicity is intense and the stimulative odor exists, accordingly they are hard to use practically. Cutting was easier when the salt water added with acetone was used than the case of rape-seed oil, but salt water is corrosive. Recently, the machining of molybdenum has been often carried out, and the water soluble cutting oil was the best. It is also good for cutting stainless steel, and its lubricating property is improved by adding some additives such as sulfur, chlorine, phosphorus and molybdenum disulfide. However after cutting with it, washing is required. (Kako, I.)

  17. Departments as Agents of Change

    Science.gov (United States)

    Lagowski, J. J.

    1996-07-01

    Higher education is changing because it has no choice. And, for the most part, outside influences are dictating the processes of change. The more fortunate institutions have had a flat budget during this period, but most have been forced to deal with a declining revenue stream as well. Legislators seem bent on micromanaging state-supported institutions, even as they cut their support. Regulators demand greater institutional accountability. Students and their parents expect more service at lower prices and increased flexibility. Technological advances have dramatically affected the availability and accessibility of extant knowledge. It is no longer a question of whether institutions will change, but rather, who will control the change. Most institutions possess long-standing academic traditions, but these are placed at risk in an increasingly competitive market that holds little sympathy for such traditions and may even see them as obstacles or barriers. As a result, the change agents will undoubtedly have a profound effect on the very nature of academic institutions. From the academic point of view, it would seem prudent to attempt to manage the changes that will inevitably occur. A number of concerned observers, notably the Pew Higher Education Roundtable and the American Association for Higher Education, argue persuasively that the academic department is the logical focus for responding to the current winds of change. Using a marketing metaphor, the academic department has been likened to a "producers' cooperative" of services that consumers seek. Thus, the department should be held accountable for the quality of teaching delivered by its members, for the coherence of its major, for its contributions to the general education curriculum, and for supervising and rewarding its individual faculty members. If departments are to be held accountable, it is surely in their best interest to act in such a way that they are accountable. Expecting academic departments to be

  18. Pedagogical agent design: The impact of agent gender, ethnicity, and instructional role

    OpenAIRE

    Baylor, A. L.; Kim, Yanghee

    2004-01-01

    To investigate the role of pedagogical agent gender and ethnicity, 230 students were randomly assigned to one of twelve conditions, where agents differed by ethnicity (African-American, Caucasian), gender (male, female), and roles (expert, motivator, and mentor).

  19. Safe motion planning for mobile agents: A model of reactive planning for multiple mobile agents

    Energy Technology Data Exchange (ETDEWEB)

    Fujimura, Kikuo.

    1990-01-01

    The problem of motion planning for multiple mobile agents is studied. Each planning agent independently plans its own action based on its map which contains a limited information about the environment. In an environment where more than one mobile agent interacts, the motions of the robots are uncertain and dynamic. A model for reactive agents is described and simulation results are presented to show their behavior patterns. 18 refs., 2 figs.

  20. Core Competencies Of A Call Centre AgentCore Competencies Of A Call Centre Agent

    OpenAIRE

    Christine White; Vera Roos

    2005-01-01

    Call centre agents are becoming increasingly important in the call centre context. They act as a contact point between the customer and the company. Call centre agents should have certain competencies to perform their duties sufficiently. Identifying competencies, required to be effective agents, will ease the task of training and recruitment. Due to the interrelatedness of the call centre agent, the management of a call centre and customers, all relevant role players’ perceptions were taken ...

  1. Stock market dynamics created by interacting agents

    Directory of Open Access Journals (Sweden)

    Karl-Theodor Eisele

    2006-06-01

    Full Text Available We study a stock market model, consisting in a large number of agents, going eventually to infinity, and evaluate the stock price under the influence of opinions of different agents. Next we study the behavior of prices when the market is very nervous; there appear discontinuities (phase transitions which can be interpreted as stock market crashes.

  2. Explanation in human-agent teamwork

    NARCIS (Netherlands)

    Harbers, M.; Bradshaw, J.M.; Johnson, M.; Feltovich, P.; Bosch, K. van den; Meyer, J.J.C.

    2012-01-01

    There are several applications in which humans and agents jointly perform a task. If the task involves interdependence among the team members, coordination is required to achieve good team performance. This paper discusses the role of explanation in coordination in human-agent teams. Explanations ab

  3. Assurance in Agent-Based Systems

    International Nuclear Information System (INIS)

    Our vision of the future of information systems is one that includes engineered collectives of software agents which are situated in an environment over years and which increasingly improve the performance of the overall system of which they are a part. At a minimum, the movement of agent and multi-agent technology into National Security applications, including their use in information assurance, is apparent today. The use of deliberative, autonomous agents in high-consequence/high-security applications will require a commensurate level of protection and confidence in the predictability of system-level behavior. At Sandia National Laboratories, we have defined and are addressing a research agenda that integrates the surety (safety, security, and reliability) into agent-based systems at a deep level. Surety is addressed at multiple levels: The integrity of individual agents must be protected by addressing potential failure modes and vulnerabilities to malevolent threats. Providing for the surety of the collective requires attention to communications surety issues and mechanisms for identifying and working with trusted collaborators. At the highest level, using agent-based collectives within a large-scale distributed system requires the development of principled design methods to deliver the desired emergent performance or surety characteristics. This position paper will outline the research directions underway at Sandia, will discuss relevant work being performed elsewhere, and will report progress to date toward assurance in agent-based systems

  4. Designing Negotiating Agent for Automated Negotiations

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Traditional research in automated negotiation is focused on negotiation protocol and strategy.This paper studies automated negotiation from a new point of view, proposes a novel concept, namely negotiating agent, and discusses its significance in construction of automated negotiation system, with an abstract model formally described and the architecture designed, which supports both goal-directed reasoning and reactive response. A communication model was proposed to construct interaction mechanism used by negotiating agents, in which the negotiation language used by agents is defined.The communication model and the language are defined in a way general enough to support a wide variety of market mechanisms, thus being particularly suitable for flexible applications such as electronic business. The design and expression of the negotiation ontology is also discussed. On the base of the theoretical model of negotiating agent, negotiating agent architecture and negotiating agent communication model (NACM) are explicit and formal specifications for the agents negotiating in an E-business environment; especially, NACM defines the negotiation language template shared among all agents formally and explicitly. The novelty of the communication model is twofold.

  5. PU Sizing Agent Sector Starts Reform

    Institute of Scientific and Technical Information of China (English)

    Wang Lei

    2007-01-01

    @@ Polyurethane (PU) sizing agent is a thermoplastic PU elastomer extensively used in synthetic leather, artificial deerskin and electrostatic flocking sectors. The drastic production and demand increase of synthetic leather in China in recent years has promoted rapid consumption growth of PU sizing agent.

  6. VIRAL GASTROENTERITIS AGENTS AND WATERBORNE DISEASE

    Science.gov (United States)

    The application of electron microscopic techniques in the study of human gastroenteritis led in the 1970's to the identification of new viral agents that had previously escaped detection by routine cell culture procedures. These agents have been the focus of study by researchers ...

  7. Modeling agents with a theory of mind

    NARCIS (Netherlands)

    Harbers, M.; Bosch, K. van den; Meyer, J.J.C.

    2009-01-01

    Training systems with intelligent virtual agents provide an effective means to train people for complex, dynamic tasks like crisis management or firefighting. Virtual agents provide more adequate behavior and explanations if they not only take their own goals and beliefs into account, but also the a

  8. Practice among Novice Change Agents in Schools

    Science.gov (United States)

    Blossing, Ulf

    2016-01-01

    The aim of the article is to understand practice as negotiation of meaning among novice and internal change agents in school organisations. The research question is as follows: What themes of participation and reification/management occur among the change agents? The study was qualitative in design using the social learning theory of community of…

  9. Computational Intelligence Agent-Oriented Modelling

    Czech Academy of Sciences Publication Activity Database

    Neruda, Roman

    2006-01-01

    Roč. 5, č. 2 (2006), s. 430-433. ISSN 1109-2777 R&D Projects: GA MŠk 1M0567 Institutional research plan: CEZ:AV0Z10300504 Keywords : multi - agent system s * adaptive agent s * computational intelligence Subject RIV: IN - Informatics, Computer Science

  10. Transient Diversity in Multi-Agent Systems

    OpenAIRE

    Lyback, David

    2003-01-01

    Diversity is an important aspect of highly efficient multi-agent teams. We introduce the main factors that drive a multi-agent system in either direction along the diversity scale. A metric for diversity is described, and we speculate on the concept of transient diversity. Finally, an experiment on social entropy using a RoboCup simulated soccer team is presented.

  11. Security of Mobile Agents on the Internet.

    Science.gov (United States)

    Corradi, Antonio; Montanari, Rebecca; Stefanelli, Cesare

    2001-01-01

    Discussion of the Internet focuses on new programming paradigms based on mobile agents. Considers the security issues associated with mobile agents and proposes a security architecture composed of a wide set of services and components capable of adapting to a variety of applications, particularly electronic commerce. (Author/LRW)

  12. Agent programming languages: programming with mental models

    NARCIS (Netherlands)

    Hindriks, K.V.

    2001-01-01

    Intelligent Agents are personal assistants which can provide proactive support to users by executing routine activities like searching on the Internet, the scheduling of meetings, etc. The concept of an Intelligent Agent has its roots in Artificial Intelligence and provides a basis for the con

  13. Ultrasound contrast agents: An overview

    Energy Technology Data Exchange (ETDEWEB)

    Cosgrove, David [Imaging Sciences Department, Imperial College, Hammersmith Hospital, London (United Kingdom)]. E-mail: d.cosgrove@csc.mrc.ac.uk

    2006-12-15

    With the introduction of microbubble contrast agents, diagnostic ultrasound has entered a new era that allows the dynamic detection of tissue flow of both the macro and microvasculature. Underpinning this development is the fact that gases are compressible, and thus the microbubbles expand and contract in the alternating pressure waves of the ultrasound beam, while tissue is almost incompressible. Special software using multiple pulse sequences separates these signals from those of tissue and displays them as an overlay or on a split screen. This can be done at low acoustic pressures (MI < 0.3) so that the microbubbles are not destroyed and scanning can continue in real time. The clinical roles of contrast enhanced ultrasound scanning are expanding rapidly. They are established in echocardiography to improve endocardial border detection and are being developed for myocardial perfusion. In radiology, the most important application is the liver, especially for focal disease. The approach parallels that of dynamic CT or MRI but ultrasound has the advantages of high spatial and temporal resolution. Thus, small lesions that can be indeterminate on CT can often be studied with ultrasound, and situations where the flow is very rapid (e.g., focal nodular hyperplasia where the first few seconds of arterial perfusion may be critical to making the diagnosis) are readily studied. Microbubbles linger in the extensive sinusoidal space of normal liver for several minutes whereas they wash out rapidly from metastases, which have a low vascular volume and thus appear as filling defects. The method has been shown to be as sensitive as three-phase CT. Microbubbles have clinical uses in many other applications where knowledge of the microcirculation is important (the macrocirculation can usually be assessed adequately using conventional Doppler though there are a few important situations where the signal boost given by microbubbles is useful, e.g., transcranial Doppler for evaluating

  14. Your company's secret change agents.

    Science.gov (United States)

    Pascale, Richard Tanner; Sternin, Jerry

    2005-05-01

    Organizational change has traditionally come about through top-down initiatives such as hiring experts or importing best-of-breed practices. Such methods usually result in companywide rollouts of templates mandated from on high. These do little to get people excited. But within every organization, there are a few individuals who find unique ways to look at problems that seem impossible to solve. Although these change agents start out with the same tools and access to resources as their peers, they are able to see solutions where others do not. They find a way to bridge the divide between what is happening and what is possible. These positive deviants are the key, the authors believe, to a better way of creating organizational change. Your company can make the most of their methods by following six steps. In Step 1, Make the group the guru, the members of the community are engaged in the process of their own evolution. Step 2, Reframe through facts, entails restating the problem in a way that opens minds to new possibilities. Step 3, Make it safe to learn, involves creating an environment that supports innovative ideas. In Step 4, Make the problem concrete, the community combats abstraction by stating uncomfortable truths. In Step 5, Leverage social proof, the community looks to the larger society for examples of solutions that have worked in parallel situations. In Step 6, Confound the immune defense response, solutions are introduced organically from within the group in a way that promotes acceptance. Throughout the steps, the leader must suspend his or her traditional role in favor of more facilitatory practices. The positive-deviance approach has unearthed solutions to such complicated and diverse problems as malnutrition in Mali and human trafficking in East Java. This methodology can help solve even the most extreme dilemmas. PMID:15929405

  15. 9th KES Conference on Agent and Multi-Agent Systems : Technologies and Applications

    CERN Document Server

    Howlett, Robert; Jain, Lakhmi

    2015-01-01

    Agents and multi-agent systems are related to a modern software paradigm which has long been recognized as a promising technology for constructing autonomous, complex and intelligent systems. The topics covered in this volume include agent-oriented software engineering, agent co-operation, co-ordination, negotiation, organization and communication, distributed problem solving, specification of agent communication languages, agent privacy, safety and security, formalization of ontologies and conversational agents. The volume highlights new trends and challenges in agent and multi-agent research and includes 38 papers classified in the following specific topics: learning paradigms, agent-based modeling and simulation, business model innovation and disruptive technologies, anthropic-oriented computing, serious games and business intelligence, design and implementation of intelligent agents and multi-agent systems, digital economy, and advances in networked virtual enterprises. Published p...

  16. Advances on Practical Applications of Agents and Multi-Agent Systems 10th International Conference on Practical Applications of Agents and Multi-Agent Systems

    CERN Document Server

    Müller, Jörg; Rodríguez, Juan; Pérez, Javier

    2012-01-01

    Research on Agents and Multi-Agent Systems has matured during the last decade and many effective applications of this technology are now deployed. PAAMS provides an international forum to present and discuss the latest scientific developments and their effective applications, to assess the impact of the approach, and to facilitate technology transfer. PAAMS started as a local initiative, but has since grown to become THE international yearly platform to present, to discuss, and to disseminate the latest developments and the most important outcomes related to real-world applications. It provides a unique opportunity to bring multi-disciplinary experts, academics and practitioners together to exchange their experience in the development and deployment of Agents and Multi-Agent Systems. PAAMS intends to bring together researchers and developers from industry and the academic world to report on the latest scientific and technical advances on the application of multi-agent systems, to discuss and debate the major ...

  17. Highlights on Practical Applications of Agents and Multi-Agent Systems 10th International Conference on Practical Applications of Agents and Multi-Agent Systems

    CERN Document Server

    Sánchez, Miguel; Mathieu, Philippe; Rodríguez, Juan; Adam, Emmanuel; Ortega, Alfonso; Moreno, María; Navarro, Elena; Hirsch, Benjamin; Lopes-Cardoso, Henrique; Julián, Vicente

    2012-01-01

    Research on Agents and Multi-Agent Systems has matured during the last decade and many effective applications of this technology are now deployed. PAAMS provides an international forum to present and discuss the latest scientific developments and their effective applications, to assess the impact of the approach, and to facilitate technology transfer. PAAMS started as a local initiative, but has since grown to become THE international yearly platform to present, to discuss, and to disseminate the latest developments and the most important outcomes related to real-world applications. It provides a unique opportunity to bring multi-disciplinary experts, academics and practitioners together to exchange their experience in the development and deployment of Agents and Multi-Agent Systems. PAAMS intends to bring together researchers and developers from industry and the academic world to report on the latest scientific and technical advances on the application of multi-agent systems, to discuss and debate the major ...

  18. Security Issues in Mobile Agent Paradigm

    Directory of Open Access Journals (Sweden)

    Nitin Jain

    2011-05-01

    Full Text Available A mobile Agent is a Software program that migrates from node tonode of a heterogeneous network. They are goal-oriented i.e. workautonomously towards a goal, capable of suspending their executionon one platform and moving to other where they can resumeexecution using resources of these nodes and they meet and interactwith other agents. Agents may be stationary, always resident at asingle platform or mobile, capable of moving among differentplatforms at different time. The mobile agent paradigm providesmany benefits in developments of distributed application at the sametime introduce new requirements for security issues with thesesystems. In this paper we try to focus mainly on security issues thatarise when mobile agent paradigm comes into play.

  19. Fault Reconnaissance Agent for Sensor Networks

    Directory of Open Access Journals (Sweden)

    Elhadi M. Shakshuki

    2010-01-01

    Full Text Available One of the key prerequisite for a scalable, effective and efficient sensor network is the utilization of low-cost, low-overhead and high-resilient fault-inference techniques. To this end, we propose an intelligent agent system with a problem solving capability to address the issue of fault inference in sensor network environments. The intelligent agent system is designed and implemented at base-station side. The core of the agent system – problem solver – implements a fault-detection inference engine which harnesses Expectation Maximization (EM algorithm to estimate fault probabilities of sensor nodes. To validate the correctness and effectiveness of the intelligent agent system, a set of experiments in a wireless sensor testbed are conducted. The experimental results show that our intelligent agent system is able to precisely estimate the fault probability of sensor nodes.

  20. Development of Soda Residue Concrete Expansion Agent

    Institute of Scientific and Technical Information of China (English)

    WANG Bao-min; WANG Li-jiu; M F Mohd Zain; F C Lai

    2003-01-01

    A new type of concrete expansion agent has been successfully developed for the first time in the world by utilizing an industrial waste residue-soda residue and an industrial wasteliquor.Adding 3%-6% of the agent into Portland cement enables a shrinkage-compensating concrete to be prepared.Mortar and concrete containing this expansion agent have better shrinkage-compensating and mechanical properties.The raw materials component,production process,technical properties,micro-analysis of mortar made with this expansion agent,mechanism of expansion and research results are described in this article.The experimental results show that the new type of concrete expansion agent accords with the standard and its main mineral component is xCaO-ySO3-zAl2O3.

  1. A Network Management Framework Using Mobile Agents

    Directory of Open Access Journals (Sweden)

    Jonathan Lefebvre

    2006-01-01

    Full Text Available Network management of heterogeneous networks is still hard to achieve automatically and efficiently. In this study, we present a framework that has the ability to perform network management tasks on heterogeneous networks using mobile agents. This framework handles the inability of many network devices to run mobile agents. While the main focus of the project is the framework, we present an example of mobile agents that are able to locate a fixed set of network failures and detect the possible causes accurately. Experimental results show that some network management tasks can be more easily executed by mobile agents. In particular, search and diagnostic mobile agents are able to find more precisely a cause of a network failure by finding alternate paths to gather more data about the failure.

  2. Econophysics of agent-based models

    CERN Document Server

    Aoyama, Hideaki; Chakrabarti, Bikas; Chakraborti, Anirban; Ghosh, Asim

    2014-01-01

    The primary goal of this book is to present the research findings and conclusions of physicists, economists, mathematicians and financial engineers working in the field of "Econophysics" who have undertaken agent-based modelling, comparison with empirical studies and related investigations. Most standard economic models assume the existence of the representative agent, who is “perfectly rational” and applies the utility maximization principle when taking action. One reason for this is the desire to keep models mathematically tractable: no tools are available to economists for solving non-linear models of heterogeneous adaptive agents without explicit optimization. In contrast, multi-agent models, which originated from statistical physics considerations, allow us to go beyond the prototype theories of traditional economics involving the representative agent. This book is based on the Econophys-Kolkata VII Workshop, at which many such modelling efforts were presented. In the book, leading researchers in the...

  3. CEST and PARACEST MR contrast agents

    International Nuclear Information System (INIS)

    In this review we describe the status of development for a new class of magnetic resonance (MR) contrast agents, based on chemical exchange saturation transfer (CEST). The mathematics and physics relevant to the description of the CEST effect in MR are presented in an appendix published in the online version only. We discuss the issues arising when translating in vitro results obtained with CEST agents to using these MR agents in in vivo model studies and in humans. Examples are given on how these agents are imaged in vivo. We summarize the status of development of these CEST agents, and speculate about the next steps that may be taken towards the demonstration of CEST MR imaging in clinical applications

  4. Incorporating Inertia Into Multi-Agent Systems

    CERN Document Server

    Man, W C

    2005-01-01

    We consider a model that demonstrates the crucial role of inertia and stickiness in multi-agent systems, based on the Minority Game (MG). The inertia of an agent is introduced into the game model by allowing agents to apply hypothesis testing when choosing their best strategies, thereby reducing their reactivity towards changes in the environment. From massive numerical simulations, a remarkable improvement of global cooperation is observed throughout the whole phase space, and the maladaptation behaviour due to over-reaction of agents is removed. Also, these agents are found to be advantageous over the standard ones, which are sometimes too sensitive to attain a fair success rate. Analytical calculation on determining the minimum amount of inertia needed to achieve the above improvement is also provided, which is consistent with the numerical data.

  5. Ecology Based Decentralized Agent Management System

    Science.gov (United States)

    Peysakhov, Maxim D.; Cicirello, Vincent A.; Regli, William C.

    2004-01-01

    The problem of maintaining a desired number of mobile agents on a network is not trivial, especially if we want a completely decentralized solution. Decentralized control makes a system more r e bust and less susceptible to partial failures. The problem is exacerbated on wireless ad hoc networks where host mobility can result in significant changes in the network size and topology. In this paper we propose an ecology-inspired approach to the management of the number of agents. The approach associates agents with living organisms and tasks with food. Agents procreate or die based on the abundance of uncompleted tasks (food). We performed a series of experiments investigating properties of such systems and analyzed their stability under various conditions. We concluded that the ecology based metaphor can be successfully applied to the management of agent populations on wireless ad hoc networks.

  6. For whom will the Bayesian agents vote?

    Science.gov (United States)

    Caticha, Nestor; Cesar, Jonatas; Vicente, Renato

    2015-04-01

    Within an agent-based model where moral classifications are socially learned, we ask if a population of agents behaves in a way that may be compared with conservative or liberal positions in the real political spectrum. We assume that agents first experience a formative period, in which they adjust their learning style acting as supervised Bayesian adaptive learners. The formative phase is followed by a period of social influence by reinforcement learning. By comparing data generated by the agents with data from a sample of 15000 Moral Foundation questionnaires we found the following. 1. The number of information exchanges in the formative phase correlates positively with statistics identifying liberals in the social influence phase. This is consistent with recent evidence that connects the dopamine receptor D4-7R gene, political orientation and early age social clique size. 2. The learning algorithms that result from the formative phase vary in the way they treat novelty and corroborative information with more conservative-like agents treating it more equally than liberal-like agents. This is consistent with the correlation between political affiliation and the Openness personality trait reported in the literature. 3. Under the increase of a model parameter interpreted as an external pressure, the statistics of liberal agents resemble more those of conservative agents, consistent with reports on the consequences of external threats on measures of conservatism. We also show that in the social influence phase liberal-like agents readapt much faster than conservative-like agents when subjected to changes on the relevant set of moral issues. This suggests a verifiable dynamical criterium for attaching liberal or conservative labels to groups.

  7. Agent-based Modeling and Mapping of Manufacturing System

    Institute of Scientific and Technical Information of China (English)

    Z; Zhang

    2002-01-01

    Considering the gent-based modeling and mapping in m anufacturing system, in this paper, some system models are described, which are including: Domain Based Hierarchical Structure (DBHS), Cascading Agent Struc ture (CAS), Proximity Relation structure (PRS), and Bus-based network structure (BNS). In DBHS, one sort of agent individually delegates Domain Agents, Res ources Agents, UserInterface Agents and Gateway Agents and the other one is a br oker of tasks and process flow. Static agents representing...

  8. An Application of Mobile Agent System in Network Management

    Institute of Scientific and Technical Information of China (English)

    YANG Chen-xiang; DU Jun-ping; YIN Yi-xin

    2004-01-01

    This paper describes an application of a reusable mobile agent system in network management. A mobile agent reusable system is constructed to realize a new method in forming mobile agent systems. By using this method, an agent can change its route dynamically without making any change to its specific behavior. By classifying mobile agents into two categories, the task agent can be reusable in different networks. In this way, a mobile agent system can easily carry out network management tasks.

  9. Multi-Agent Systems for E-Commerce

    OpenAIRE

    Solodukha, T. V.; Sosnovskiy, O. A.; Zhelezko, B. A.

    2009-01-01

    The article focuses on multi-agent systems (MAS) and domains that can benefit from multi-agent technology. In the last few years, the agent based modeling (ABM) community has developed several practical agent based modeling toolkits that enable individuals to develop agent-based applications. The comparison of agent-based modeling toolkits is given. Multi-agent systems are designed to handle changing and dynamic business processes. Any organization with complex and distributed busine...

  10. Agent-Supported Mission Operations Teamwork

    Science.gov (United States)

    Malin, Jane T.

    2003-01-01

    This slide presentation reviews the development of software agents to support of mission operations teamwork. The goals of the work was to make automation by agents easy to use, supervise and direct, manage information and communication to decrease distraction, interruptions, workload and errors, reduce mission impact of off-nominal situations and increase morale and decrease turnover. The accomplishments or the project are: 1. Collaborative agents - mixed initiative and creation of instructions for mediating agent 2. Methods for prototyping, evaluating and evolving socio-technical systems 3. Technology infusion: teamwork tools in mISSIons 4. Demonstrations in simulation testbed An example of the use of agent is given, the use of an agent to monitor a N2 tank leak. An incomplete instruction to the agent is handled with mediating assistants, or Intelligent Briefing and Response Assistant (IBRA). The IBRA Engine also watches data stream for triggers and executes Act-Whenever actions. There is also a Briefing and Response Instruction (BRI) which is easy for a discipline specialist to create through a BRI editor.

  11. Persistent agents in Axelrod's social dynamics model

    Science.gov (United States)

    Reia, Sandro M.; Neves, Ubiraci P. C.

    2016-01-01

    Axelrod's model of social dynamics has been studied under the effect of external media. Here we study the formation of cultural domains in the model by introducing persistent agents. These are agents whose cultural traits are not allowed to change but may be spread through local neighborhood. In the absence of persistent agents, the system is known to present a transition from a monocultural to a multicultural regime at some critical Q (number of traits). Our results reveal a dependence of critical Q on the occupation probability p of persistent agents and we obtain the phase diagram of the model in the (p,Q) -plane. The critical locus is explained by the competition of two opposite forces named here barrier and bonding effects. Such forces are verified to be caused by non-persistent agents which adhere (adherent agents) to the set of traits of persistent ones. The adherence (concentration of adherent agents) as a function of p is found to decay for constant Q. Furthermore, adherence as a function of Q is found to decay as a power law with constant p.

  12. Dynamic Channel Allocation Management Using Agents Technology

    Directory of Open Access Journals (Sweden)

    Ion BOGDAN

    2009-07-01

    Full Text Available Channel allocation schemes are management techniques meant to solve the radio access problem in the telecommunications area. There are several known schemes namely: static, dynamic, hybrid and flexible channel allocation schemes. In our work we developed the channel allocation scheme using a decentralized structure, based on software agents. In order to create such a structure, some functions must be carried out by some specialized functional entities. Each functional entity is implemented with an agent, having a specific role. Using this manner of implementation, different functions of the system can be implemented at different sites, located apart and also the structure can be modularized. In our work we have created the agents structure and the communications between agents, on the use of Multiagent Systems Engineering Technology. We also involved the AgentTool platform to automate the creation of the agents structure and the code resulted was in Java. In order to realize the test of our system we considered a shape of 21 radio areas, each including a number of users. Each wireless user can initiate a number of calls per hour and each call last a holding time. The communications between agents were realized for the TCP/IP protocol, based on socket connections.

  13. [Decorporation agents for internal radioactive contamination].

    Science.gov (United States)

    Ohmachi, Yasushi

    2015-01-01

    When radionuclides are accidentally ingested or inhaled, blood circulation or tissue/organ deposition of the radionuclides causes systemic or local radiation effects. In such cases, decorporation therapy is used to reduce the health risks due to their intake. Decorporation therapy includes reduction and/or inhibition of absorption from the gastrointestinal tract, isotopic dilution, and the use of diuretics, adsorbents, and chelating agents. For example, penicillamine is recommended as a chelating agent for copper contamination, and diethylene triamine pentaacetic acid is approved for the treatment of internal contamination with plutonium. During chelation therapy, the removal effect of the drugs should be monitored using a whole-body counter and/or bioassay. Some authorities, such as the National Council on Radiation Protection and Measurements and International Atomic Energy Agency, have reported recommended decorporation agents for each radionuclide. However, few drugs are approved by the US Food and Drug Administration, and many are off-label-use agents. Because many decontamination agents are drugs that have been available for a long time and have limited efficacy, the development of new, higher-efficacy drugs has been carried out mainly in the USA and France. In this article, in addition to an outline of decorporation agents for internal radioactive contamination, an outline of our research on decorporation agents for actinide (uranium and plutonium) contamination and for radio-cesium contamination is also presented. PMID:25832835

  14. Agent and multi-Agent systems in distributed systems digital economy and e-commerce

    CERN Document Server

    Hartung, Ronald

    2013-01-01

    Information and communication technology, in particular artificial intelligence, can be used to support economy and commerce using digital means. This book is about agents and multi-agent distributed systems applied to digital economy and e-commerce to meet, improve, and overcome challenges in the digital economy and e-commerce sphere. Agent and multi-agent solutions are applied in implementing real-life, exciting developments associated with the need to eliminate problems of distributed systems.   The book presents solutions for both technology and applications, illustrating the possible uses of agents in the enterprise domain, covering design and analytic methods, needed to provide a solid foundation required for practical systems. More specifically, the book provides solutions for the digital economy, e-sourcing clusters in network economy, and knowledge exchange between agents applicable to online trading agents, and security solutions to both digital economy and e-commerce. Furthermore, it offers soluti...

  15. Designing Agent Utilities for Coordinated, Scalable and Robust Multi-Agent Systems

    Science.gov (United States)

    Tumer, Kagan

    2005-01-01

    Coordinating the behavior of a large number of agents to achieve a system level goal poses unique design challenges. In particular, problems of scaling (number of agents in the thousands to tens of thousands), observability (agents have limited sensing capabilities), and robustness (the agents are unreliable) make it impossible to simply apply methods developed for small multi-agent systems composed of reliable agents. To address these problems, we present an approach based on deriving agent goals that are aligned with the overall system goal, and can be computed using information readily available to the agents. Then, each agent uses a simple reinforcement learning algorithm to pursue its own goals. Because of the way in which those goals are derived, there is no need to use difficult to scale external mechanisms to force collaboration or coordination among the agents, or to ensure that agents actively attempt to appropriate the tasks of agents that suffered failures. To present these results in a concrete setting, we focus on the problem of finding the sub-set of a set of imperfect devices that results in the best aggregate device. This is a large distributed agent coordination problem where each agent (e.g., device) needs to determine whether to be part of the aggregate device. Our results show that the approach proposed in this work provides improvements of over an order of magnitude over both traditional search methods and traditional multi-agent methods. Furthermore, the results show that even in extreme cases of agent failures (i.e., half the agents failed midway through the simulation) the system's performance degrades gracefully and still outperforms a failure-free and centralized search algorithm. The results also show that the gains increase as the size of the system (e.g., number of agents) increases. This latter result is particularly encouraging and suggests that this method is ideally suited for domains where the number of agents is currently in the

  16. Fluorescence quenching of flavins by reductive agents

    Science.gov (United States)

    Penzkofer, A.; Bansal, A. K.; Song, S.-H.; Dick, B.

    2007-07-01

    The fluorescence behaviour of the flavins riboflavin, flavin mononucleotide (FMN), flavin adenine dinucleotide (FAD), and lumiflavin in aqueous solution at pH 8 in the presence of the reducing agents β-mercaptoethanol (β-ME), dithiothreitol (DTT), and sodium nitrite (NaNO 2) is studied under aerobic conditions. The fluorescence quantum yields and fluorescence lifetimes are determined as a function of the reducing agent concentration. For all three reducing agents diffusion controlled dynamic fluorescence quenching is observed which is thought to be due to photo-induced reductive electron transfer. For DTT additionally static fluorescence quenching occurs.

  17. Information Service Model with Mobile Agent Supported

    Institute of Scientific and Technical Information of China (English)

    邹涛; 王继成; 张福炎

    2000-01-01

    Mobile Agent is a kind of novel agent technology characterized by mobile, intelligent, parallel and asynchronous computing. In this paper, a new information service model that adopts mobile agent technology is introduced first,and then an experimental system DOLTRIA system that is implemented based on the model is described. The DOLTRIA system implemented by WWW framework and Java can search for relevant HTML documents on a set of Web servers. The result of experiments shows that performance improvement can be achieved by this model, and both the elapsed time and network traffic are reduced significantly.

  18. Fluorescence quenching of flavins by reductive agents

    Energy Technology Data Exchange (ETDEWEB)

    Penzkofer, A. [Institut II - Experimentelle und Angewandte Physik, Universitaet Regensburg, Universitaetsstrasse 31, D-93053 Regensburg (Germany)], E-mail: alfons.penzkofer@physik.uni-regensburg.de; Bansal, A.K. [Institut II - Experimentelle und Angewandte Physik, Universitaet Regensburg, Universitaetsstrasse 31, D-93053 Regensburg (Germany); Song, S.-H.; Dick, B. [Institut fuer Physikalische und Theoretische Chemie, Universitaet Regensburg, Universitaetsstrasse 31, 93053 Regensburg (Germany)

    2007-07-09

    The fluorescence behaviour of the flavins riboflavin, flavin mononucleotide (FMN), flavin adenine dinucleotide (FAD), and lumiflavin in aqueous solution at pH 8 in the presence of the reducing agents {beta}-mercaptoethanol ({beta}-ME), dithiothreitol (DTT), and sodium nitrite (NaNO{sub 2}) is studied under aerobic conditions. The fluorescence quantum yields and fluorescence lifetimes are determined as a function of the reducing agent concentration. For all three reducing agents diffusion controlled dynamic fluorescence quenching is observed which is thought to be due to photo-induced reductive electron transfer. For DTT additionally static fluorescence quenching occurs.

  19. On agent-mediated electronic commerce

    OpenAIRE

    He, M.; Jennings, N. R.; Leung, H.

    2003-01-01

    This paper surveys and analyzes the state of the art of agent-mediated electronic commerce (e-commerce), concentrating particularly on the business-to-consumer (B2C) and business-to-business (B2B) aspects. From the consumer buying behavior perspective, agents are being used in the following activities: need identification, product brokering, buyer coalition formation, merchant brokering, and negotiation. The roles of agents in B2B e-commerce are discussed through the business-to-business tran...

  20. Towards Culturally-Aware Virtual Agent Systems

    DEFF Research Database (Denmark)

    Endrass, Birgit; André, Elisabeth; Rehm, Matthias

    2010-01-01

    game-like environment in a more interesting way than for example learning with a textbook. The authors support the idea that virtual agents are a great opportunity for teaching cultural awareness. Realizing this, the concept of culture needs to be translated into computational models and the advantages...... of different systems using virtual agents need to be considered. Therefore, the authors reflect in this chapter on how virtual agents can help to learn about culture, scan definitions of culture from the social sciences, give an overview on how multiagent systems developed over time and classify the...