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Sample records for damaging therapeutic agent

  1. Acute Organophosphate Poisonings: Therapeutic Dilemmas and New Potential Therapeutic Agents

    International Nuclear Information System (INIS)

    Vucinic, S.; Jovanovic, D.; Vucinic, Z.; Todorovic, V.; Segrt, Z.

    2007-01-01

    It has been six decades since synthesis of organophosphates, but this chapter has not yet come to a closure. Toxic effects of organophosphates are well known and the current therapeutic scheme includes supportive therapy and antidotes. There is a dilemma on whether and when to apply gastric lavage and activated charcoal. According to Position Statement (by EAPCCT) it should be applied only if the patient presents within one hour of ingestion, with potentially lethal ingested dose. Atropine, a competitive antagonist of acetylcholine at m-receptors, which antagonizes bronchosecretion and bronchoconstriction, is the corner stone of acute organophosphate poisoning therapy. There were many attempts to find a more efficient drug, including glycopyrrolate which has been used even in clinical trials, but it still can not replace atropine. The only dilemma about atropine usage which still exists, concerns usage of high atropine dose and scheme of application. The most efficient atropinization is achieved with bolus doses of 1-2mg of atropine i.v push, with repeating the dose on each 5 minutes until signs of atropinization are registered. Diazepam, with its GABA stabilizing effect, reduces central nervous system damage and central respiratory weakness. Oximes reactivate phosphorylated acetylcholinesterase, which still has not gone ageing, reducing acetylcholine concentration and cholinergic crisis. These effects are clearly demonstrated in experimental conditions, but the clinical significance of oximes is still unclear and there are still those who question oxime therapy. For those who approve it, oxime dosage, duration of therapy, the choice of oxime for certain OP is still an open issue. We need new, more efficient antidotes, and those that are in use are only the small part of the therapy which could be used. Experimental studies show favorable therapeutic effect of many agents, but none of them has been introduced in standard treatment of OPI poisoning in the last 30

  2. ATM regulates 3-methylpurine-DNA glycosylase and promotes therapeutic resistance to alkylating agents.

    Science.gov (United States)

    Agnihotri, Sameer; Burrell, Kelly; Buczkowicz, Pawel; Remke, Marc; Golbourn, Brian; Chornenkyy, Yevgen; Gajadhar, Aaron; Fernandez, Nestor A; Clarke, Ian D; Barszczyk, Mark S; Pajovic, Sanja; Ternamian, Christian; Head, Renee; Sabha, Nesrin; Sobol, Robert W; Taylor, Michael D; Rutka, James T; Jones, Chris; Dirks, Peter B; Zadeh, Gelareh; Hawkins, Cynthia

    2014-10-01

    Alkylating agents are a first-line therapy for the treatment of several aggressive cancers, including pediatric glioblastoma, a lethal tumor in children. Unfortunately, many tumors are resistant to this therapy. We sought to identify ways of sensitizing tumor cells to alkylating agents while leaving normal cells unharmed, increasing therapeutic response while minimizing toxicity. Using an siRNA screen targeting over 240 DNA damage response genes, we identified novel sensitizers to alkylating agents. In particular, the base excision repair (BER) pathway, including 3-methylpurine-DNA glycosylase (MPG), as well as ataxia telangiectasia mutated (ATM), were identified in our screen. Interestingly, we identified MPG as a direct novel substrate of ATM. ATM-mediated phosphorylation of MPG was required for enhanced MPG function. Importantly, combined inhibition or loss of MPG and ATM resulted in increased alkylating agent-induced cytotoxicity in vitro and prolonged survival in vivo. The discovery of the ATM-MPG axis will lead to improved treatment of alkylating agent-resistant tumors. Inhibition of ATM and MPG-mediated BER cooperate to sensitize tumor cells to alkylating agents, impairing tumor growth in vitro and in vivo with no toxicity to normal cells, providing an ideal therapeutic window. ©2014 American Association for Cancer Research.

  3. A virtual therapeutic environment with user projective agents.

    Science.gov (United States)

    Ookita, S Y; Tokuda, H

    2001-02-01

    Today, we see the Internet as more than just an information infrastructure, but a socializing place and a safe outlet of inner feelings. Many personalities develop aside from real world life due to its anonymous environment. Virtual world interactions are bringing about new psychological illnesses ranging from netaddiction to technostress, as well as online personality disorders and conflicts in multiple identities that exist in the virtual world. Presently, there are no standard therapy models for the virtual environment. There are very few therapeutic environments, or tools especially made for virtual therapeutic environments. The goal of our research is to provide the therapy model and middleware tools for psychologists to use in virtual therapeutic environments. We propose the Cyber Therapy Model, and Projective Agents, a tool used in the therapeutic environment. To evaluate the effectiveness of the tool, we created a prototype system, called the Virtual Group Counseling System, which is a therapeutic environment that allows the user to participate in group counseling through the eyes of their Projective Agent. Projective Agents inherit the user's personality traits. During the virtual group counseling, the user's Projective Agent interacts and collaborates to recover and increase their psychological growth. The prototype system provides a simulation environment where psychologists can adjust the parameters and customize their own simulation environment. The model and tool is a first attempt toward simulating online personalities that may exist only online, and provide data for observation.

  4. Genome-Wide Requirements for Resistance to Functionally Distinct DNA-Damaging Agents.

    Directory of Open Access Journals (Sweden)

    2005-08-01

    Full Text Available The mechanistic and therapeutic differences in the cellular response to DNA-damaging compounds are not completely understood, despite intense study. To expand our knowledge of DNA damage, we assayed the effects of 12 closely related DNA-damaging agents on the complete pool of ~4,700 barcoded homozygous deletion strains of Saccharomyces cerevisiae. In our protocol, deletion strains are pooled together and grown competitively in the presence of compound. Relative strain sensitivity is determined by hybridization of PCR-amplified barcodes to an oligonucleotide array carrying the barcode complements. These screens identified genes in well-characterized DNA-damage-response pathways as well as genes whose role in the DNA-damage response had not been previously established. High-throughput individual growth analysis was used to independently confirm microarray results. Each compound produced a unique genome-wide profile. Analysis of these data allowed us to determine the relative importance of DNA-repair modules for resistance to each of the 12 profiled compounds. Clustering the data for 12 distinct compounds uncovered both known and novel functional interactions that comprise the DNA-damage response and allowed us to define the genetic determinants required for repair of interstrand cross-links. Further genetic analysis allowed determination of epistasis for one of these functional groups.

  5. Development of Class IIa Bacteriocins as Therapeutic Agents

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    Christopher T. Lohans

    2012-01-01

    Full Text Available Class IIa bacteriocins have been primarily explored as natural food preservatives, but there is much interest in exploring the application of these peptides as therapeutic antimicrobial agents. Bacteriocins of this class possess antimicrobial activity against several important human pathogens. Therefore, the therapeutic development of these bacteriocins will be reviewed. Biological and chemical modifications to both stabilize and increase the potency of bacteriocins are discussed, as well as the optimization of their production and purification. The suitability of bacteriocins as pharmaceuticals is explored through determinations of cytotoxicity, effects on the natural microbiota, and in vivo efficacy in mouse models. Recent results suggest that class IIa bacteriocins show promise as a class of therapeutic agents.

  6. Application of Mesenchymal Stem Cells for Therapeutic Agent Delivery in Anti-tumor Treatment

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    Daria S. Chulpanova

    2018-03-01

    Full Text Available Mesenchymal stem cells (MSCs are non-hematopoietic progenitor cells, which can be isolated from different types of tissues including bone marrow, adipose tissue, tooth pulp, and placenta/umbilical cord blood. There isolation from adult tissues circumvents the ethical concerns of working with embryonic or fetal stem cells, whilst still providing cells capable of differentiating into various cell lineages, such as adipocytes, osteocytes and chondrocytes. An important feature of MSCs is the low immunogenicity due to the lack of co-stimulatory molecules expression, meaning there is no need for immunosuppression during allogenic transplantation. The tropism of MSCs to damaged tissues and tumor sites makes them a promising vector for therapeutic agent delivery to tumors and metastatic niches. MSCs can be genetically modified by virus vectors to encode tumor suppressor genes, immunomodulating cytokines and their combinations, other therapeutic approaches include MSCs priming/loading with chemotherapeutic drugs or nanoparticles. MSCs derived membrane microvesicles (MVs, which play an important role in intercellular communication, are also considered as a new therapeutic agent and drug delivery vector. Recruited by the tumor, MSCs can exhibit both pro- and anti-oncogenic properties. In this regard, for the development of new methods for cancer therapy using MSCs, a deeper understanding of the molecular and cellular interactions between MSCs and the tumor microenvironment is necessary. In this review, we discuss MSC and tumor interaction mechanisms and review the new therapeutic strategies using MSCs and MSCs derived MVs for cancer treatment.

  7. The Growing Complexity of Cancer Cell Response to DNA-Damaging Agents: Caspase 3 Mediates Cell Death or Survival?

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    Razmik Mirzayans

    2016-05-01

    Full Text Available It is widely stated that wild-type p53 either mediates the activation of cell cycle checkpoints to facilitate DNA repair and promote cell survival, or orchestrates apoptotic cell death following exposure to cancer therapeutic agents. This reigning paradigm has been challenged by numerous discoveries with different human cell types, including solid tumor-derived cell lines. Thus, activation of the p53 signaling pathway by ionizing radiation and other DNA-damaging agents hinders apoptosis and triggers growth arrest (e.g., through premature senescence in some genetic backgrounds; such growth arrested cells remain viable, secrete growth-promoting factors, and give rise to progeny with stem cell-like properties. In addition, caspase 3, which is best known for its role in the execution phase of apoptosis, has been recently reported to facilitate (rather than suppress DNA damage-induced genomic instability and carcinogenesis. This observation is consistent with an earlier report demonstrating that caspase 3 mediates secretion of the pro-survival factor prostaglandin E2, which in turn promotes enrichment of tumor repopulating cells. In this article, we review these and related discoveries and point out novel cancer therapeutic strategies. One of our objectives is to demonstrate the growing complexity of the DNA damage response beyond the conventional “repair and survive, or die” hypothesis.

  8. Balancing repair and tolerance of DNA damage caused by alkylating agents.

    Science.gov (United States)

    Fu, Dragony; Calvo, Jennifer A; Samson, Leona D

    2012-01-12

    Alkylating agents constitute a major class of frontline chemotherapeutic drugs that inflict cytotoxic DNA damage as their main mode of action, in addition to collateral mutagenic damage. Numerous cellular pathways, including direct DNA damage reversal, base excision repair (BER) and mismatch repair (MMR), respond to alkylation damage to defend against alkylation-induced cell death or mutation. However, maintaining a proper balance of activity both within and between these pathways is crucial for a favourable response of an organism to alkylating agents. Furthermore, the response of an individual to alkylating agents can vary considerably from tissue to tissue and from person to person, pointing to genetic and epigenetic mechanisms that modulate alkylating agent toxicity.

  9. Quantitative Analyses of Synergistic Responses between Cannabidiol and DNA-Damaging Agents on the Proliferation and Viability of Glioblastoma and Neural Progenitor Cells in Culture.

    Science.gov (United States)

    Deng, Liting; Ng, Lindsay; Ozawa, Tatsuya; Stella, Nephi

    2017-01-01

    Evidence suggests that the nonpsychotropic cannabis-derived compound, cannabidiol (CBD), has antineoplastic activity in multiple types of cancers, including glioblastoma multiforme (GBM). DNA-damaging agents remain the main standard of care treatment available for patients diagnosed with GBM. Here we studied the antiproliferative and cell-killing activity of CBD alone and in combination with DNA-damaging agents (temozolomide, carmustine, or cisplatin) in several human GBM cell lines and in mouse primary GBM cells in cultures. This activity was also studied in mouse neural progenitor cells (NPCs) in culture to assess for potential central nervous system toxicity. We found that CBD induced a dose-dependent reduction of both proliferation and viability of all cells with similar potencies, suggesting no preferential activity for cancer cells. Hill plot analysis indicates an allosteric mechanism of action triggered by CBD in all cells. Cotreatment regimens combining CBD and DNA-damaging agents produced synergistic antiproliferating and cell-killing responses over a limited range of concentrations in all human GBM cell lines and mouse GBM cells as well as in mouse NPCs. Remarkably, antagonistic responses occurred at low concentrations in select human GBM cell lines and in mouse GBM cells. Our study suggests limited synergistic activity when combining CBD and DNA-damaging agents in treating GBM cells, along with little to no therapeutic window when considering NPCs. Copyright © 2016 by The American Society for Pharmacology and Experimental Therapeutics.

  10. Incidence of insects, diseases, and other damaging agents in Oregon forests.

    Science.gov (United States)

    Paul A. Dunham

    2008-01-01

    This report uses data from a network of forest inventory plots sampled at two points in time, annual aerial insect and disease surveys, and specialized pest damage surveys to quantify the incidence and impact of insects, diseases, and other damaging agents on Oregon's forests. The number and volume of trees damaged or killed by various agents is summarized....

  11. Inhibiting DNA Polymerases as a Therapeutic Intervention against Cancer

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    Anthony J. Berdis

    2017-11-01

    Full Text Available Inhibiting DNA synthesis is an important therapeutic strategy that is widely used to treat a number of hyperproliferative diseases including viral infections, autoimmune disorders, and cancer. This chapter describes two major categories of therapeutic agents used to inhibit DNA synthesis. The first category includes purine and pyrmidine nucleoside analogs that directly inhibit DNA polymerase activity. The second category includes DNA damaging agents including cisplatin and chlorambucil that modify the composition and structure of the nucleic acid substrate to indirectly inhibit DNA synthesis. Special emphasis is placed on describing the molecular mechanisms of these inhibitory effects against chromosomal and mitochondrial DNA polymerases. Discussions are also provided on the mechanisms associated with resistance to these therapeutic agents. A primary focus is toward understanding the roles of specialized DNA polymerases that by-pass DNA lesions produced by DNA damaging agents. Finally, a section is provided that describes emerging areas in developing new therapeutic strategies targeting specialized DNA polymerases.

  12. A survey of the sequence-specific interaction of damaging agents with DNA: emphasis on antitumor agents.

    Science.gov (United States)

    Murray, V

    1999-01-01

    This article reviews the literature concerning the sequence specificity of DNA-damaging agents. DNA-damaging agents are widely used in cancer chemotherapy. It is important to understand fully the determinants of DNA sequence specificity so that more effective DNA-damaging agents can be developed as antitumor drugs. There are five main methods of DNA sequence specificity analysis: cleavage of end-labeled fragments, linear amplification with Taq DNA polymerase, ligation-mediated polymerase chain reaction (PCR), single-strand ligation PCR, and footprinting. The DNA sequence specificity in purified DNA and in intact mammalian cells is reviewed for several classes of DNA-damaging agent. These include agents that form covalent adducts with DNA, free radical generators, topoisomerase inhibitors, intercalators and minor groove binders, enzymes, and electromagnetic radiation. The main sites of adduct formation are at the N-7 of guanine in the major groove of DNA and the N-3 of adenine in the minor groove, whereas free radical generators abstract hydrogen from the deoxyribose sugar and topoisomerase inhibitors cause enzyme-DNA cross-links to form. Several issues involved in the determination of the DNA sequence specificity are discussed. The future directions of the field, with respect to cancer chemotherapy, are also examined.

  13. Development of Class IIa Bacteriocins as Therapeutic Agents

    OpenAIRE

    Christopher T. Lohans; John C. Vederas

    2012-01-01

    Class IIa bacteriocins have been primarily explored as natural food preservatives, but there is much interest in exploring the application of these peptides as therapeutic antimicrobial agents. Bacteriocins of this class possess antimicrobial activity against several important human pathogens. Therefore, the therapeutic development of these bacteriocins will be reviewed. Biological and chemical modifications to both stabilize and increase the potency of bacteriocins are discussed, as well as ...

  14. Therapeutic Hypothermia Reduces Oxidative Damage and Alters Antioxidant Defenses after Cardiac Arrest

    Science.gov (United States)

    Hackenhaar, Fernanda S.; Medeiros, Tássia M.; Heemann, Fernanda M.; Behling, Camile S.; Putti, Jordana S.; Mahl, Camila D.; Verona, Cleber; da Silva, Ana Carolina A.; Guerra, Maria C.; Gonçalves, Carlos A. S.; Oliveira, Vanessa M.; Riveiro, Diego F. M.; Vieira, Silvia R. R.

    2017-01-01

    After cardiac arrest, organ damage consequent to ischemia-reperfusion has been attributed to oxidative stress. Mild therapeutic hypothermia has been applied to reduce this damage, and it may reduce oxidative damage as well. This study aimed to compare oxidative damage and antioxidant defenses in patients treated with controlled normothermia versus mild therapeutic hypothermia during postcardiac arrest syndrome. The sample consisted of 31 patients under controlled normothermia (36°C) and 11 patients treated with 24 h mild therapeutic hypothermia (33°C), victims of in- or out-of-hospital cardiac arrest. Parameters were assessed at 6, 12, 36, and 72 h after cardiac arrest in the central venous blood samples. Hypothermic and normothermic patients had similar S100B levels, a biomarker of brain injury. Xanthine oxidase activity is similar between hypothermic and normothermic patients; however, it decreases posthypothermia treatment. Xanthine oxidase activity is positively correlated with lactate and S100B and inversely correlated with pH, calcium, and sodium levels. Hypothermia reduces malondialdehyde and protein carbonyl levels, markers of oxidative damage. Concomitantly, hypothermia increases the activity of erythrocyte antioxidant enzymes superoxide dismutase, glutathione peroxidase, and glutathione S-transferase while decreasing the activity of serum paraoxonase-1. These findings suggest that mild therapeutic hypothermia reduces oxidative damage and alters antioxidant defenses in postcardiac arrest patients. PMID:28553435

  15. Relay tracking control for second-order multi-agent systems with damaged agents.

    Science.gov (United States)

    Dong, Lijing; Li, Jing; Liu, Qin

    2017-11-01

    This paper investigates a situation where smart agents capable of sensory and mobility are deployed to monitor a designated area. A preset number of agents start tracking when a target intrudes this area. Some of the tracking agents are possible to be out of order over the tracking course. Thus, we propose a cooperative relay tracking strategy to ensure the successful tracking with existence of damaged agents. Relay means that, when a tracking agent quits tracking due to malfunction, one of the near deployed agents replaces it to continue the tracking task. This results in jump of tracking errors and dynamic switching of topology of the multi-agent system. Switched system technique is employed to solve this specific problem. Finally, the effectiveness of proposed tracking strategy and validity of the theoretical results are verified by conducting a numerical simulation. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

  16. Multirate delivery of multiple therapeutic agents from metal-organic frameworks

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    Alistair C. McKinlay

    2014-12-01

    Full Text Available The highly porous nature of metal-organic frameworks (MOFs offers great potential for the delivery of therapeutic agents. Here, we show that highly porous metal-organic frameworks can be used to deliver multiple therapeutic agents—a biologically active gas, an antibiotic drug molecule, and an active metal ion—simultaneously but at different rates. The possibilities offered by delivery of multiple agents with different mechanisms of action and, in particular, variable timescales may allow new therapy approaches. Here, we show that the loaded MOFs are highly active against various strains of bacteria.

  17. MicroRNAs, the DNA damage response and cancer

    International Nuclear Information System (INIS)

    Wouters, Maikel D.; Gent, Dik C. van; Hoeijmakers, Jan H.J.; Pothof, Joris

    2011-01-01

    Many carcinogenic agents such as ultra-violet light from the sun and various natural and man-made chemicals act by damaging the DNA. To deal with these potentially detrimental effects of DNA damage, cells induce a complex DNA damage response (DDR) that includes DNA repair, cell cycle checkpoints, damage tolerance systems and apoptosis. This DDR is a potent barrier against carcinogenesis and defects within this response are observed in many, if not all, human tumors. DDR defects fuel the evolution of precancerous cells to malignant tumors, but can also induce sensitivity to DNA damaging agents in cancer cells, which can be therapeutically exploited by the use of DNA damaging treatment modalities. Regulation of and coordination between sub-pathways within the DDR is important for maintaining genome stability. Although regulation of the DDR has been extensively studied at the transcriptional and post-translational level, less is known about post-transcriptional gene regulation by microRNAs, the topic of this review. More specifically, we highlight current knowledge about DNA damage responsive microRNAs and microRNAs that regulate DNA damage response genes. We end by discussing the role of DNA damage response microRNAs in cancer etiology and sensitivity to ionizing radiation and other DNA damaging therapeutic agents.

  18. Epigenetic and genetic factors in the cellular response to radiations and DNA-damaging chemicals

    International Nuclear Information System (INIS)

    Williams, J.R.; D'Arpa, P.

    1981-01-01

    DNA-damaging agents are widely used as therapeutic tools for a variety of disease states. Many such agents are considered to produce detrimental side effects. Thus, it is important to evaluate both therapeutic efficacy and potential risk. DNA-damaging agents can be so evaluated by comparison to agents whose therapeutic benefit and potential hazards are better known. We propose a framework for such comparison, demonstrating that a simple transformation of cytotoxicity-dose response patterns permits a facile comparison of variation between cells exposed to a single DNA-damaging agent or to different cytotoxic agents. Further, by transforming data from experiments which compare responses of 2 cell populations to an effects ratio, different patterns for the changes in cytotoxicity produced by epigenetic and genetic factors were compared. Using these transformations, we found that there is a wide variation (a factor of 4) between laboratories for a single agent (UVC) and only a slightly larger variation (factor of 6) between normal cell response for different types of DNA-damaging agents (x-ray, UVC, alkylating agents, crosslinking agents). Epigenetic factors such as repair and recovery appear to be a factor only at higher dose levels. Comparison in the cytotoxic effect of a spectrum of DNA-damaging agents in xeroderma pigmentosum, ataxia telangiectasia, and Fanconi's anemia cells indicates significantly different patterns, implying that the effect, and perhaps the nature, of these genetic conditions are quite different

  19. Applications of inorganic nanoparticles as therapeutic agents

    Science.gov (United States)

    Kim, Taeho; Hyeon, Taeghwan

    2014-01-01

    During the last decade, various functional nanostructured materials with interesting optical, magnetic, mechanical and chemical properties have been extensively applied to biomedical areas including imaging, diagnosis and therapy. In therapeutics, most research has focused on the application of nanoparticles as potential delivery vehicles for drugs and genes, because nanoparticles in the size range of 2-100 nm can interact with biological systems at the molecular level, and allow targeted delivery and passage through biological barriers. Recent investigations have even revealed that several kinds of nanomaterials are intrinsically therapeutic. Not only can they passively interact with cells, but they can also actively mediate molecular processes to regulate cell functions. This can be seen in the treatment of cancer via anti-angiogenic mechanisms as well as the treatment of neurodegenerative diseases by effectively controlling oxidative stress. This review will present recent applications of inorganic nanoparticles as therapeutic agents in the treatment of disease.

  20. Therapeutic strategies with oral fluoropyrimidine anticancer agent, S-1 against oral cancer.

    Science.gov (United States)

    Harada, Koji; Ferdous, Tarannum; Ueyama, Yoshiya

    2017-08-01

    Oral cancer has been recognized as a tumor with low sensitivity to anticancer agents. However, introduction of S-1, an oral cancer agent is improving treatment outcome for patients with oral cancer. In addition, S-1, as a main drug for oral cancer treatment in Japan can be easily available for outpatients. In fact, S-1 exerts high therapeutic effects with acceptable side effects. Moreover, combined chemotherapy with S-1 shows higher efficacy than S-1 alone, and combined chemo-radiotherapy with S-1 exerts remarkable therapeutic effects. Furthermore, we should consider the combined therapy of S-1 and molecular targeting agents right now as these combinations were reportedly useful for oral cancer treatment. Here, we describe our findings related to S-1 that were obtained experimentally and clinically, and favorable therapeutic strategies with S-1 against oral cancer with bibliographic considerations.

  1. Hypersensitivity to DNA-damaging agents in primary degenerations of excitable tissue

    International Nuclear Information System (INIS)

    Robbins, J.H.

    1983-01-01

    Defects in DNA-repair mechanisms render xeroderma pigmentosum cells hypersensitive to killing by the uv-type of DNA-damaging agent. Some xeroderma pigmentosum patients develop a primary neuronal degeneration, and cell lines from patients with the earliest onset of neurodegeneration are the most sensitive to killing by uv radiation. These findings led to the neuronal DNA integrity theory which holds that when the integrity of neuronal DNA is destroyed by the accumulation of unrepaired DNA damaged spontaneously or by endogenous metabolites, the neurons will undergo a primary degeneration. Cells from patients with Cockayne syndrome, a demyelinating disorder with a primary retinal degeneration, are also hypersensitive to the uv-type of DNA-damaging agent. Cells from patients with the primary neuronal degeneration of ataxia telangiectasia are hypersensitive to the x-ray-type of DNA-damaging agent. Cells from other patients with primary degeneration of excitable tissue also have hypersensitivity to the x-ray-type of DNA-damaging agent. These disorders include (1) primary neuronal degenerations which are either genetic (e.g., Huntington disease, familial dysautonomia, Friedreich ataxia) or sporadic (e.g., Alzheimer disease, Parkinson disease), (2) primary muscle degenerations (e.g., Duchenne muscular dystrophy), and (3) a primary retinal degeneration (Usher syndrome). Death of excitable tissue in vivo in these radiosensitive diseases may result from unrepaired DNA. This hypersensitivity provides the basis for developing suitable presymptomatic and prenatal tests for these diseases, for elucidating their pathogenesis, and for developing future therapies. 119 references, 3 figures, 3 tables

  2. Glutamine deficiency induces DNA alkylation damage and sensitizes cancer cells to alkylating agents through inhibition of ALKBH enzymes.

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    Thai Q Tran

    2017-11-01

    Full Text Available Driven by oncogenic signaling, glutamine addiction exhibited by cancer cells often leads to severe glutamine depletion in solid tumors. Despite this nutritional environment that tumor cells often experience, the effect of glutamine deficiency on cellular responses to DNA damage and chemotherapeutic treatment remains unclear. Here, we show that glutamine deficiency, through the reduction of alpha-ketoglutarate, inhibits the AlkB homolog (ALKBH enzymes activity and induces DNA alkylation damage. As a result, glutamine deprivation or glutaminase inhibitor treatment triggers DNA damage accumulation independent of cell death. In addition, low glutamine-induced DNA damage is abolished in ALKBH deficient cells. Importantly, we show that glutaminase inhibitors, 6-Diazo-5-oxo-L-norleucine (DON or CB-839, hypersensitize cancer cells to alkylating agents both in vitro and in vivo. Together, the crosstalk between glutamine metabolism and the DNA repair pathway identified in this study highlights a potential role of metabolic stress in genomic instability and therapeutic response in cancer.

  3. Glutamine deficiency induces DNA alkylation damage and sensitizes cancer cells to alkylating agents through inhibition of ALKBH enzymes.

    Science.gov (United States)

    Tran, Thai Q; Ishak Gabra, Mari B; Lowman, Xazmin H; Yang, Ying; Reid, Michael A; Pan, Min; O'Connor, Timothy R; Kong, Mei

    2017-11-01

    Driven by oncogenic signaling, glutamine addiction exhibited by cancer cells often leads to severe glutamine depletion in solid tumors. Despite this nutritional environment that tumor cells often experience, the effect of glutamine deficiency on cellular responses to DNA damage and chemotherapeutic treatment remains unclear. Here, we show that glutamine deficiency, through the reduction of alpha-ketoglutarate, inhibits the AlkB homolog (ALKBH) enzymes activity and induces DNA alkylation damage. As a result, glutamine deprivation or glutaminase inhibitor treatment triggers DNA damage accumulation independent of cell death. In addition, low glutamine-induced DNA damage is abolished in ALKBH deficient cells. Importantly, we show that glutaminase inhibitors, 6-Diazo-5-oxo-L-norleucine (DON) or CB-839, hypersensitize cancer cells to alkylating agents both in vitro and in vivo. Together, the crosstalk between glutamine metabolism and the DNA repair pathway identified in this study highlights a potential role of metabolic stress in genomic instability and therapeutic response in cancer.

  4. Ultrasound enhanced delivery of molecular imaging and therapeutic agents in Alzheimer's disease mouse models.

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    Scott B Raymond

    Full Text Available Alzheimer's disease is a neurodegenerative disorder typified by the accumulation of a small protein, beta-amyloid, which aggregates and is the primary component of amyloid plaques. Many new therapeutic and diagnostic agents for reducing amyloid plaques have limited efficacy in vivo because of poor transport across the blood-brain barrier. Here we demonstrate that low-intensity focused ultrasound with a microbubble contrast agent may be used to transiently disrupt the blood-brain barrier, allowing non-invasive, localized delivery of imaging fluorophores and immunotherapeutics directly to amyloid plaques. We administered intravenous Trypan blue, an amyloid staining red fluorophore, and anti-amyloid antibodies, concurrently with focused ultrasound therapy in plaque-bearing, transgenic mouse models of Alzheimer's disease with amyloid pathology. MRI guidance permitted selective treatment and monitoring of plaque-heavy anatomical regions, such as the hippocampus. Treated brain regions exhibited 16.5+/-5.4-fold increase in Trypan blue fluorescence and 2.7+/-1.2-fold increase in anti-amyloid antibodies that localized to amyloid plaques. Ultrasound-enhanced delivery was consistently reproduced in two different transgenic strains (APPswe:PSEN1dE9, PDAPP, across a large age range (9-26 months, with and without MR guidance, and with little or no tissue damage. Ultrasound-mediated, transient blood-brain barrier disruption allows the delivery of both therapeutic and molecular imaging agents in Alzheimer's mouse models, which should aid pre-clinical drug screening and imaging probe development. Furthermore, this technique may be used to deliver a wide variety of small and large molecules to the brain for imaging and therapy in other neurodegenerative diseases.

  5. Sea urchin coelomocytes are resistant to a variety of DNA damaging agents

    International Nuclear Information System (INIS)

    Loram, Jeannette; Raudonis, Renee; Chapman, Jecar; Lortie, Mae; Bodnar, Andrea

    2012-01-01

    Increasing anthropogenic activities are creating environmental pressures that threaten marine ecosystems. Effective environmental health assessment requires the development of rapid, sensitive, and cost-effective tools to predict negative impacts at the individual and ecosystem levels. To this end, a number of biological assays using a variety of cells and organisms measuring different end points have been developed for biomonitoring programs. The sea urchin fertilization/development test has been useful for evaluating environmental toxicology and it has been proposed that sea urchin coelomocytes represent a novel cellular biosensor of environmental stress. In this study we investigated the sensitivity of coelomocytes from the sea urchin Lytechinus variegatus to a variety of DNA-damaging agents including ultraviolet (UV) radiation, hydrogen peroxide (H 2 O 2 ), methylmethane sulfonate (MMS) and benzo[a]pyrene (BaP). LD 50 values determined for coelomocytes after 24 h of exposure to these DNA damaging agents indicated a high level of resistance to all treatments. Significant increases in the formation of apurinic/apyrimidinic (AP or abasic) sites in DNA were only detected using high doses of H 2 O 2 , MMS and UV radiation. Comparison of sea urchin coelomocytes with hemocytes from the gastropod mollusk Aplysia dactylomela and the decapod crustacean Panulirus argus indicated that sensitivity to different DNA damaging agents varies between species. The high level of resistance to genotoxic agents suggests that DNA damage may not be an informative end point for environmental health assessment using sea urchin coelomocytes however, natural resistance to DNA damaging agents may have implications for the occurrence of neoplastic disease in these animals.

  6. Balancing repair and tolerance of DNA damage caused by alkylating agents

    OpenAIRE

    Fu, Dragony; Calvo, Jennifer A.; Samson, Leona D.

    2012-01-01

    Alkylating agents constitute a major class of frontline chemotherapeutic drugs that inflict cytotoxic DNA damage as their main mode of action, in addition to collateral mutagenic damage. Numerous cellular pathways, including direct DNA damage reversal, base excision repair (BER) and mismatch repair (MMR), respond to alkylation damage to defend against alkylation-induced cell death or mutation. However, maintaining a proper balance of activity both within and between these pathways is crucial ...

  7. Sea urchin coelomocytes are resistant to a variety of DNA damaging agents

    Energy Technology Data Exchange (ETDEWEB)

    Loram, Jeannette; Raudonis, Renee; Chapman, Jecar; Lortie, Mae [Bermuda Institute of Ocean Sciences, St. George' s, Bermuda, GE 01 (Bermuda); Bodnar, Andrea, E-mail: andrea.bodnar@bios.edu [Bermuda Institute of Ocean Sciences, St. George' s, Bermuda, GE 01 (Bermuda)

    2012-11-15

    Increasing anthropogenic activities are creating environmental pressures that threaten marine ecosystems. Effective environmental health assessment requires the development of rapid, sensitive, and cost-effective tools to predict negative impacts at the individual and ecosystem levels. To this end, a number of biological assays using a variety of cells and organisms measuring different end points have been developed for biomonitoring programs. The sea urchin fertilization/development test has been useful for evaluating environmental toxicology and it has been proposed that sea urchin coelomocytes represent a novel cellular biosensor of environmental stress. In this study we investigated the sensitivity of coelomocytes from the sea urchin Lytechinus variegatus to a variety of DNA-damaging agents including ultraviolet (UV) radiation, hydrogen peroxide (H{sub 2}O{sub 2}), methylmethane sulfonate (MMS) and benzo[a]pyrene (BaP). LD{sub 50} values determined for coelomocytes after 24 h of exposure to these DNA damaging agents indicated a high level of resistance to all treatments. Significant increases in the formation of apurinic/apyrimidinic (AP or abasic) sites in DNA were only detected using high doses of H{sub 2}O{sub 2}, MMS and UV radiation. Comparison of sea urchin coelomocytes with hemocytes from the gastropod mollusk Aplysia dactylomela and the decapod crustacean Panulirus argus indicated that sensitivity to different DNA damaging agents varies between species. The high level of resistance to genotoxic agents suggests that DNA damage may not be an informative end point for environmental health assessment using sea urchin coelomocytes however, natural resistance to DNA damaging agents may have implications for the occurrence of neoplastic disease in these animals.

  8. Therapeutic neuroprotective agents for amyotrophic lateral sclerosis

    Science.gov (United States)

    Pandya, Rachna S.; Zhu, Haining; Li, Wei; Bowser, Robert; Friedlander, Robert M.

    2014-01-01

    Amyotrophic lateral sclerosis (ALS) is a fatal chronic neurodegenerative disease whose hallmark is proteinaceous, ubiquitinated, cytoplasmic inclusions in motor neurons and surrounding cells. Multiple mechanisms proposed as responsible for ALS pathogenesis include dysfunction of protein degradation, glutamate excitotoxicity, mitochondrial dysfunction, apoptosis, oxidative stress, and inflammation. It is therefore essential to gain a better understanding of the underlying disease etiology and search for neuroprotective agents that might delay disease onset, slow progression, prolong survival, and ultimately reduce the burden of disease. Because riluzole, the only Food and Drug Administration (FDA)-approved treatment, prolongs the ALS patient’s life by only 3 months, new therapeutic agents are urgently needed. In this review, we focus on studies of various small pharmacological compounds targeting the proposed pathogenic mechanisms of ALS and discuss their impact on disease progression. PMID:23864030

  9. SERIES: Genomic instability in cancer Balancing repair and tolerance of DNA damage caused by alkylating agents

    Science.gov (United States)

    Fu, Dragony; Calvo, Jennifer A.; Samson, Leona D

    2013-01-01

    Alkylating agents comprise a major class of frontline chemotherapeutic drugs that inflict cytotoxic DNA damage as their main mode of action, in addition to collateral mutagenic damage. Numerous cellular pathways, including direct DNA damage reversal, base excision repair (BER), and mismatch repair (MMR) respond to alkylation damage to defend against alkylation-induced cell death or mutation. However, maintaining a proper balance of activity both within and between these pathways is crucial for an organism's favorable response to alkylating agents. Furthermore, an individual's response to alkylating agents can vary considerably from tissue to tissue and from person to person, pointing to genetic and epigenetic mechanisms that modulate alkylating agent toxicity. PMID:22237395

  10. Selective estrogen receptor modulators as brain therapeutic agents

    OpenAIRE

    Arévalo, María Ángeles; Santos-Galindo, María; Lagunas, Natalia; Azcoitia, I.; García-Segura, Luis M.

    2011-01-01

    Selective estrogen receptor modulators (SERMs), used for the treatment of breast cancer, osteoporosis, and menopausal symptoms, affect the nervous system. Some SERMs trigger neuroprotective mechanisms and reduce neural damage in different experimental models of neural trauma, brain inflammation, neurodegenerative diseases, cognitive impairment, and affective disorders. New SERMs with specific actions on neurons and glial cells may represent promising therapeutic tools for the brain. © 2011 So...

  11. Regulation of DNA Alkylation Damage Repair: Lessons and Therapeutic Opportunities.

    Science.gov (United States)

    Soll, Jennifer M; Sobol, Robert W; Mosammaparast, Nima

    2017-03-01

    Alkylation chemotherapy is one of the most widely used systemic therapies for cancer. While somewhat effective, clinical responses and toxicities of these agents are highly variable. A major contributing factor for this variability is the numerous distinct lesions that are created upon alkylation damage. These adducts activate multiple repair pathways. There is mounting evidence that the individual pathways function cooperatively, suggesting that coordinated regulation of alkylation repair is critical to prevent toxicity. Furthermore, some alkylating agents produce adducts that overlap with newly discovered methylation marks, making it difficult to distinguish between bona fide damaged bases and so-called 'epigenetic' adducts. Here, we discuss new efforts aimed at deciphering the mechanisms that regulate these repair pathways, emphasizing their implications for cancer chemotherapy. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Developing Inhibitors of Translesion DNA Synthesis as Therapeutic Agents Against Lung Cancer

    Science.gov (United States)

    2014-10-01

    pol eta when replicating damaged DNA. 1S. SUBJECT TERMS: Mutagenesis, DNA polymerases, nucleoside analogs, chemotherapeutic agents 16. SECURITY ...such as polymerase eta, iota , and kappa that are involved in replicating damaged DNA. Our kinetic data obtained under Task 1B indicates that pol eta

  13. Applications of inorganic nanoparticles as therapeutic agents

    International Nuclear Information System (INIS)

    Kim, Taeho; Hyeon, Taeghwan

    2014-01-01

    During the last decade, various functional nanostructured materials with interesting optical, magnetic, mechanical and chemical properties have been extensively applied to biomedical areas including imaging, diagnosis and therapy. In therapeutics, most research has focused on the application of nanoparticles as potential delivery vehicles for drugs and genes, because nanoparticles in the size range of 2–100 nm can interact with biological systems at the molecular level, and allow targeted delivery and passage through biological barriers. Recent investigations have even revealed that several kinds of nanomaterials are intrinsically therapeutic. Not only can they passively interact with cells, but they can also actively mediate molecular processes to regulate cell functions. This can be seen in the treatment of cancer via anti-angiogenic mechanisms as well as the treatment of neurodegenerative diseases by effectively controlling oxidative stress. This review will present recent applications of inorganic nanoparticles as therapeutic agents in the treatment of disease. (topical review)

  14. Synergy of irofulven in combination with other DNA damaging agents: synergistic interaction with altretamine, alkylating, and platinum-derived agents in the MV522 lung tumor model.

    Science.gov (United States)

    Kelner, Michael J; McMorris, Trevor C; Rojas, Rafael J; Estes, Leita A; Suthipinijtham, Pharnuk

    2008-12-01

    Irofulven (MGI 114, NSC 683863) is a semisynthetic derivative of illudin S, a natural product present in the Omphalotus illudins (Jack O'Lantern) mushroom. This novel agent produces DNA damage, that in contrast to other agents, is predominately ignored by the global genome repair pathway of the nucleotide excision repair (NER)(2) system. The aim of this study was to determine the antitumor activity of irofulven when administered in combination with 44 different DNA damaging agents, whose damage is in general detected and repaired by the genome repair pathway. The human lung carcinoma MV522 cell line and its corresponding xenograft model were used to evaluate the activity of irofulven in combination with different DNA damaging agents. Two main classes of DNA damaging agents, platinum-derived agents, and select bifunctional alkylating agents, demonstrated in vivo synergistic or super-additive interaction with irofulven. DNA helicase inhibiting agents also demonstrated synergy in vitro, but an enhanced interaction with irofulven could not be demonstrated in vivo. There was no detectable synergistic activity between irofulven and agents capable of inducing DNA cleavage or intercalating into DNA. These results indicate that the antitumor activity of irofulven is enhanced when combined with platinum-derived agents, altretamine, and select alkylating agents such as melphalan or chlorambucil. A common factor between these agents appears to be the production of intrastrand DNA crosslinks. The synergistic interaction between irofulven and other agents may stem from the nucleotide excision repair system being selectively overwhelmed at two distinct points in the pathway, resulting in prolonged stalling of transcription forks, and subsequent initiation of apoptosis.

  15. Spherical Nucleic Acids as Intracellular Agents for Nucleic Acid Based Therapeutics

    Science.gov (United States)

    Hao, Liangliang

    Recent functional discoveries on the noncoding sequences of human genome and transcriptome could lead to revolutionary treatment modalities because the noncoding RNAs (ncRNAs) can be applied as therapeutic agents to manipulate disease-causing genes. To date few nucleic acid-based therapeutics have been translated into the clinic due to challenges in the delivery of the oligonucleotide agents in an effective, cell specific, and non-toxic fashion. Unmodified oligonucleotide agents are destroyed rapidly in biological fluids by enzymatic degradation and have difficulty crossing the plasma membrane without the aid of transfection reagents, which often cause inflammatory, cytotoxic, or immunogenic side effects. Spherical nucleic acids (SNAs), nanoparticles consisting of densely organized and highly oriented oligonucleotides, pose one possible solution to circumventing these problems in both the antisense and RNA interference (RNAi) pathways. The unique three dimensional architecture of SNAs protects the bioactive oligonucleotides from unspecific degradation during delivery and supports their targeting of class A scavenger receptors and endocytosis via a lipid-raft-dependent, caveolae-mediated pathway. Owing to their unique structure, SNAs are able to cross cell membranes and regulate target genes expression as a single entity, without triggering the cellular innate immune response. Herein, my thesis has focused on understanding the interactions between SNAs and cellular components and developing SNA-based nanostructures to improve therapeutic capabilities. Specifically, I developed a novel SNA-based, nanoscale agent for delivery of therapeutic oligonucleotides to manipulate microRNAs (miRNAs), the endogenous post-transcriptional gene regulators. I investigated the role of SNAs involving miRNAs in anti-cancer or anti-inflammation responses in cells and in in vivo murine disease models via systemic injection. Furthermore, I explored using different strategies to construct

  16. A Zebrafish Heart Failure Model for Assessing Therapeutic Agents.

    Science.gov (United States)

    Zhu, Xiao-Yu; Wu, Si-Qi; Guo, Sheng-Ya; Yang, Hua; Xia, Bo; Li, Ping; Li, Chun-Qi

    2018-03-20

    Heart failure is a leading cause of death and the development of effective and safe therapeutic agents for heart failure has been proven challenging. In this study, taking advantage of larval zebrafish, we developed a zebrafish heart failure model for drug screening and efficacy assessment. Zebrafish at 2 dpf (days postfertilization) were treated with verapamil at a concentration of 200 μM for 30 min, which were determined as optimum conditions for model development. Tested drugs were administered into zebrafish either by direct soaking or circulation microinjection. After treatment, zebrafish were randomly selected and subjected to either visual observation and image acquisition or record videos under a Zebralab Blood Flow System. The therapeutic effects of drugs on zebrafish heart failure were quantified by calculating the efficiency of heart dilatation, venous congestion, cardiac output, and blood flow dynamics. All 8 human heart failure therapeutic drugs (LCZ696, digoxin, irbesartan, metoprolol, qiliqiangxin capsule, enalapril, shenmai injection, and hydrochlorothiazide) showed significant preventive and therapeutic effects on zebrafish heart failure (p failure model developed and validated in this study could be used for in vivo heart failure studies and for rapid screening and efficacy assessment of preventive and therapeutic drugs.

  17. Effect of Some Therapeutic Agents on the Radionuclides Excretion from Internally Contaminated Rats

    International Nuclear Information System (INIS)

    Aziz, M.; Mangood, Sh.A.; Sohsah, M.A.

    2009-01-01

    The present work was oriented to investigate the effectiveness of Prussian blue (PB), vermiculite and diethylenetriaminepentaacetic acid (CaDTPA) as therapeutic agents for the elimination of either 134 Cs or 60 Co from contaminated rats after intake of one of the isotopes. The study was performed by using 48 adult rats divided into 8 identical groups each of six rats having approximately the same body weight. The groups included a reference group, without isotope or therapeutic agent administration, four groups given one of the isotopes and four groups given the isotopes and treated with different therapeutic regimes. The isotope content of the treated and untreated contaminated rats were followed by daily whole body radiometric counting for three weeks. On plotting log % radionuclide retained as a function of time, elapsed between radionuclide administration and radiometric counting, straight lines were obtained. The results indicate that excretion can mostly be represented by two stages; the first is fast followed by a second slow stage. The % radionuclide excreted, the corresponding rate constant and the biological half-life of each stage was estimated. It was found that the application of PB + vermiculite is more efficient, to remove 134 Cs, from contaminated rats, than PB only and CaDTPA is more efficient to remove 60Co. Therefore, it is recommended to use the three therapeutic agents to remove both isotopes when taken simultaneously

  18. In vitro sensitivity of normal and hereditary retinoblastoma fibroblasts to DNA-damaging agents

    International Nuclear Information System (INIS)

    Woods, W.G.; Byrne, T.D.

    1986-01-01

    We investigated the ability of nine fibroblast cell strains from patients with the hereditary form of retinoblastoma (RB) to handle various types of DNA-damaging agents and compared the results with those obtained in nine normal strains. Cell strains were exposed to gamma-radiation, which causes DNA scission; actinomycin D, a DNA-intercalating agent; and mitomycin C, a bifunctional alkylating agent leading to DNA-DNA cross-linking. Cell strains were studied for their ability to survive in a cytotoxicity assay. Nine normal strains exhibited a mean D0 (inverse of the slope of the straight line portion of the survival curve) of 134-178 cGy after radiation exposure, compared to a range of 119-186 cGy in the nine RB strains (P = 0.33). Similarly, exposure to actinomycin D led to D0 values of 0.024-0.069 microgram/ml in the nine normal strains and D0 values of 0.016-0.067 microgram/ml in the RB strains (P = 0.64). The nine RB strains did exhibit a small overall increase in sensitivity after exposure to mitomycin C, with D0 values ranging from 0.14-0.32 microgram/ml versus 0.19-0.66 microgram/ml in the nine normal strains (P = 0.002); however, when the two most resistant normal strains were excluded from analysis, results were similar. Three RB cell strains derived from individuals who had either developed second cancers or who had a family history of additional sarcomas consistently exhibited increases in sensitivity to all three DNA-damaging agents studied compared with other hereditary RB cell strains as well as normal strains. The results suggest that normal human fibroblast cell strains exhibit a wide response to DNA-damaging agents, especially chemical agents. Most hereditary RB strains exhibit sensitivity well within the normal range; however, strains from RB patients predisposed to second cancers exhibit increases in sensitivity to DNA-damaging agents

  19. Comparison of checkpoint responses triggered by DNA polymerase inhibition versus DNA damaging agents

    International Nuclear Information System (INIS)

    Liu, J.-S.; Kuo, S.-R.; Melendy, Thomas

    2003-01-01

    To better understand the different cellular responses to replication fork pausing versus blockage, early DNA damage response markers were compared after treatment of cultured mammalian cells with agents that either inhibit DNA polymerase activity (hydroxyurea (HU) or aphidicolin) or selectively induce S-phase DNA damage responses (the DNA alkylating agents, methyl methanesulfonate (MMS) and adozelesin). These agents were compared for their relative abilities to induce phosphorylation of Chk1, H2AX, and replication protein A (RPA), and intra-nuclear focalization of γ-H2AX and RPA. Treatment by aphidicolin and HU resulted in phosphorylation of Chk1, while HU, but not aphidicolin, induced focalization of γ-H2AX and RPA. Surprisingly, pre-treatment with aphidicolin to stop replication fork progression, did not abrogate HU-induced γ-H2AX and RPA focalization. This suggests that HU may act on the replication fork machinery directly, such that fork progression is not required to trigger these responses. The DNA-damaging fork-blocking agents, adozelesin and MMS, both induced phosphorylation and focalization of H2AX and RPA. Unlike adozelesin and HU, the pattern of MMS-induced RPA focalization did not match the BUdR incorporation pattern and was not blocked by aphidicolin, suggesting that MMS-induced damage is not replication fork-dependent. In support of this, MMS was the only reagent used that did not induce phosphorylation of Chk1. These results indicate that induction of DNA damage checkpoint responses due to adozelesin is both replication fork and fork progression dependent, induction by HU is replication fork dependent but progression independent, while induction by MMS is independent of both replication forks and fork progression

  20. Comparison of checkpoint responses triggered by DNA polymerase inhibition versus DNA damaging agents

    Energy Technology Data Exchange (ETDEWEB)

    Liu, J.-S.; Kuo, S.-R.; Melendy, Thomas

    2003-11-27

    To better understand the different cellular responses to replication fork pausing versus blockage, early DNA damage response markers were compared after treatment of cultured mammalian cells with agents that either inhibit DNA polymerase activity (hydroxyurea (HU) or aphidicolin) or selectively induce S-phase DNA damage responses (the DNA alkylating agents, methyl methanesulfonate (MMS) and adozelesin). These agents were compared for their relative abilities to induce phosphorylation of Chk1, H2AX, and replication protein A (RPA), and intra-nuclear focalization of {gamma}-H2AX and RPA. Treatment by aphidicolin and HU resulted in phosphorylation of Chk1, while HU, but not aphidicolin, induced focalization of {gamma}-H2AX and RPA. Surprisingly, pre-treatment with aphidicolin to stop replication fork progression, did not abrogate HU-induced {gamma}-H2AX and RPA focalization. This suggests that HU may act on the replication fork machinery directly, such that fork progression is not required to trigger these responses. The DNA-damaging fork-blocking agents, adozelesin and MMS, both induced phosphorylation and focalization of H2AX and RPA. Unlike adozelesin and HU, the pattern of MMS-induced RPA focalization did not match the BUdR incorporation pattern and was not blocked by aphidicolin, suggesting that MMS-induced damage is not replication fork-dependent. In support of this, MMS was the only reagent used that did not induce phosphorylation of Chk1. These results indicate that induction of DNA damage checkpoint responses due to adozelesin is both replication fork and fork progression dependent, induction by HU is replication fork dependent but progression independent, while induction by MMS is independent of both replication forks and fork progression.

  1. DNA Damage Induced by Alkylating Agents and Repair Pathways

    Science.gov (United States)

    Kondo, Natsuko; Takahashi, Akihisa; Ono, Koji; Ohnishi, Takeo

    2010-01-01

    The cytotoxic effects of alkylating agents are strongly attenuated by cellular DNA repair processes, necessitating a clear understanding of the repair mechanisms. Simple methylating agents form adducts at N- and O-atoms. N-methylations are removed by base excision repair, AlkB homologues, or nucleotide excision repair (NER). O6-methylguanine (MeG), which can eventually become cytotoxic and mutagenic, is repaired by O6-methylguanine-DNA methyltransferase, and O6MeG:T mispairs are recognized by the mismatch repair system (MMR). MMR cannot repair the O6MeG/T mispairs, which eventually lead to double-strand breaks. Bifunctional alkylating agents form interstrand cross-links (ICLs) which are more complex and highly cytotoxic. ICLs are repaired by complex of NER factors (e.g., endnuclease xeroderma pigmentosum complementation group F-excision repair cross-complementing rodent repair deficiency complementation group 1), Fanconi anemia repair, and homologous recombination. A detailed understanding of how cells cope with DNA damage caused by alkylating agents is therefore potentially useful in clinical medicine. PMID:21113301

  2. Onconase responsive genes in human mesothelioma cells: implications for an RNA damaging therapeutic agent

    International Nuclear Information System (INIS)

    Altomare, Deborah A; Rybak, Susanna M; Pei, Jianming; Maizel, Jacob V; Cheung, Mitchell; Testa, Joseph R; Shogen, Kuslima

    2010-01-01

    Onconase represents a new class of RNA-damaging drugs. Mechanistically, Onconase is thought to internalize, where it degrades intracellular RNAs such as tRNA and double-stranded RNA, and thereby suppresses protein synthesis. However, there may be additional or alternative mechanism(s) of action. In this study, microarray analysis was used to compare gene expression profiles in untreated human malignant mesothelioma (MM) cell lines and cells exposed to 5 μg/ml Onconase for 24 h. A total of 155 genes were found to be regulated by Onconase that were common to both epithelial and biphasic MM cell lines. Some of these genes are known to significantly affect apoptosis (IL-24, TNFAIP3), transcription (ATF3, DDIT3, MAFF, HDAC9, SNAPC1) or inflammation and the immune response (IL-6, COX-2). RT-PCR analysis of selected up- or down-regulated genes treated with varying doses and times of Onconase generally confirmed the expression array findings in four MM cell lines. Onconase treatment consistently resulted in up-regulation of IL-24, previously shown to have tumor suppressive activity, as well as ATF3 and IL-6. Induction of ATF3 and the pro-apoptotic factor IL-24 by Onconase was highest in the two most responsive MM cell lines, as defined by DNA fragmentation analysis. In addition to apoptosis, gene ontology analysis indicated that pathways impacted by Onconase include MAPK signaling, cytokine-cytokine-receptor interactions, and Jak-STAT signaling. These results provide a broad picture of gene activity after treatment with a drug that targets small non-coding RNAs and contribute to our overall understanding of MM cell response to Onconase as a therapeutic strategy. The findings provide insights regarding mechanisms that may contribute to the efficacy of this novel drug in clinical trials of MM patients who have failed first line chemotherapy or radiation treatment

  3. Bioprospecting the Curculigoside-Cinnamic Acid-Rich Fraction from Molineria latifolia Rhizome as a Potential Antioxidant Therapeutic Agent

    Directory of Open Access Journals (Sweden)

    Der Jiun Ooi

    2016-06-01

    Full Text Available Increasing evidence from both experimental and clinical studies depicts the involvement of oxidative stress in the pathogenesis of various diseases. Specifically, disruption of homeostatic redox balance in accumulated body fat mass leads to obesity-associated metabolic syndrome. Strategies for the restoration of redox balance, potentially by exploring potent plant bioactives, have thus become the focus of therapeutic intervention. The present study aimed to bioprospect the potential use of the curculigoside-cinnamic acid-rich fraction from Molineria latifolia rhizome as an antioxidant therapeutic agent. The ethyl acetate fraction (EAF isolated from M. latifolia rhizome methanolic extract (RME contained the highest amount of phenolic compounds, particularly curculigoside and cinnamic acid. EAF demonstrated glycation inhibitory activities in both glucose- and fructose-mediated glycation models. In addition, in vitro chemical-based and cellular-based antioxidant assays showed that EAF exhibited high antioxidant activities and a protective effect against oxidative damage in 3T3-L1 preadipocytes. Although the efficacies of individual phenolics differed depending on the structure and concentration, a correlational study revealed strong correlations between total phenolic contents and antioxidant capacities. The results concluded that enriched phenolic contents in EAF (curculigoside-cinnamic acid-rich fraction contributed to the overall better reactivity. Our data suggest that this bioactive-rich fraction warrants therapeutic potential against oxidative stress-related disorders.

  4. Perspectives on Phytochemicals as Antibacterial Agents: An Outstanding Contribution to Modern Therapeutics.

    Science.gov (United States)

    Khatri, Savita; Kumar, Manish; Phougat, Neetu; Chaudhary, Renu; Chhillar, Anil Kumar

    2016-01-01

    Despite the considerable advancements in the development of antimicrobial agents, incidents of epidemics due to multi drug resistance in microorganisms have created a massive hazard to mankind. Due to increased resistance against conventional antibiotics, researchers and pharmaceutical industries are more concerned about novel therapeutic agents for the prevention of bacterial infections. Enormous wealth of traditional system of medicine gains importance in health therapies over again. With ancient credentials of potent medicinal plants, various herbal remedies came forward for the management of bacterial infections. The Ayurvedic approach facilitates the development of new therapeutic agents due to structural and functional diversity among phytochemicals. The abundance and diversity is responsible for the characterization of new lead structures from medicinal plants. Industrial interest has increased due to recent research advancements viz. synergistic and high-throughput screening approach for the evaluation of vast variety of phytochemicals. The review certainly emphasizes on the traditional medicines as alternatives to conventional chemotherapeutic drugs. The review briefly describes mode of action of various antibiotics and resistance mechanisms. This review focuses on the chemical diversity and various mechanisms of action of phytochemicals against bacterial pathogens.

  5. DNA-damaging agents stimulate gene expression at specific loci in Escherichia coli

    Energy Technology Data Exchange (ETDEWEB)

    Kenyon, C.J.; Walker, G.C.

    1988-05-01

    Operon fusions in Escherichia coli were obtained that showed increased beta-galactosidase expression in response to treatment with the DNA-damaging agent mitomycin C. These fusions were generated by using the Mud(ApR, lac) vector to insert the lactose structural genes randomly into the bacterial chromosome. Induction of beta-galactosidase in these strains, which carried fusions of lac to these din (damage-inducible) loci, was (i) triggered by UV light as well as by mitomycin C and (ii) abolished by either a recA- or a lexA- mutation. Similar characteristics of induction were observed when the lactose genes were fused to a prophage lambda promoter by using Mud(ApR, lac). These results indicate that E. coli contains a set of genes that, like prophage lambda genes, are expressed in response to DNA-damaging agents and regulated by the recA and lexA gene products. These din genes map at five bacterial loci. One din::Mud(ApR, lac) insertion results in a UV-sensitive phenotype and may be within the uvrA transcriptional unit.

  6. Mesenchymal Stem Cells as New Therapeutic Agents for the Treatment of Primary Biliary Cholangitis

    Directory of Open Access Journals (Sweden)

    Aleksandar Arsenijevic

    2017-01-01

    Full Text Available Primary biliary cholangitis (PBC is a chronic autoimmune cholestatic liver disease characterized by the progressive destruction of small- and medium-sized intrahepatic bile ducts with resultant cholestasis and progressive fibrosis. Ursodeoxycholic acid and obethicholic acid are the only agents approved by the US Food and Drug Administration (FDA for the treatment of PBC. However, for patients with advanced, end-stage PBC, liver transplantation is still the most effective treatment. Accordingly, the alternative approaches, such as mesenchymal stem cell (MSC transplantation, have been suggested as an effective alternative therapy for these patients. Due to their immunomodulatory characteristics, MSCs are considered as promising therapeutic agents for the therapy of autoimmune liver diseases, including PBC. In this review, we have summarized the therapeutic potential of MSCs for the treatment of these diseases, emphasizing molecular and cellular mechanisms responsible for MSC-based effects in an animal model of PBC and therapeutic potential observed in recently conducted clinical trials. We have also presented several outstanding problems including safety issues regarding unwanted differentiation of transplanted MSCs which limit their therapeutic use. Efficient and safe MSC-based therapy for PBC remains a challenging issue that requires continuous cooperation between clinicians, researchers, and patients.

  7. Lipoprotein Nanoplatform for Targeted Delivery of Diagnostic and Therapeutic Agents

    Directory of Open Access Journals (Sweden)

    Jerry D. Glickson

    2008-03-01

    Full Text Available Low-density lipoprotein (LDL provides a highly versatile natural nanoplatform for delivery of visible or near-infrared fluorescent optical and magnetic resonance imaging (MRI contrast agents and photodynamic therapy and chemotherapeutic agents to normal and neoplastic cells that overexpress low-density lipoprotein receptors (LDLRs. Extension to other lipoproteins ranging in diameter from about 10 nm (high-density lipoprotein [HDL] to over a micron (chylomicrons is feasible. Loading of contrast or therapeutic agents onto or into these particles has been achieved by protein loading (covalent attachment to protein side chains, surface loading (intercalation into the phospholipid monolayer, and core loading (extraction and reconstitution of the triglyceride/cholesterol ester core. Core and surface loading of LDL have been used for delivery of optical imaging agents to tumor cells in vivo and in culture. Surface loading was used for delivery of gadolinium-bis-stearylamide contrast agents for in vivo MRI detection in tumor-bearing mice. Chlorin and phthalocyanine near-infrared photodynamic therapy agents (≤ 400/LDL have been attached by core loading. Protein loading was used to reroute the LDL from its natural receptor (LDLR to folate receptors and could be used to target other receptors. A semisynthetic nanoparticle has been constructed by coating magnetite iron oxide nanoparticles with carboxylated cholesterol and overlaying a monolayer of phospholipid to which apolipoprotein A1 or E was adsorbed for targeting HDL or adsorbing synthetic amphipathic helical peptides ltargeting LDL or folate receptors. These particles can be used for in situ loading of magnetite into cells for MRI-monitored cell tracking or gene expression.

  8. Protective effects of antioxidants and anti-inflammatory agents against manganese-induced oxidative damage and neuronal injury

    Energy Technology Data Exchange (ETDEWEB)

    Milatovic, Dejan, E-mail: dejan.milatovic@vanderbilt.edu [Vanderbilt University School of Medicine, Department of Pediatrics, Nashville, TN (United States); Gupta, Ramesh C. [Murray State University, Breathitt Veterinary Center, Hopkinsville, KY (United States); Yu, Yingchun; Zaja-Milatovic, Snjezana [Vanderbilt University School of Medicine, Department of Pediatrics, Nashville, TN (United States); Aschner, Michael [Vanderbilt University School of Medicine, Department of Pediatrics, Nashville, TN (United States); Pharmacology and the Kennedy Center for Research on Human Development, Nashville, TN (United States)

    2011-11-15

    Exposure to excessive manganese (Mn) levels leads to neurotoxicity, referred to as manganism, which resembles Parkinson's disease (PD). Manganism is caused by neuronal injury in both cortical and subcortical regions, particularly in the basal ganglia. The basis for the selective neurotoxicity of Mn is not yet fully understood. However, several studies suggest that oxidative damage and inflammatory processes play prominent roles in the degeneration of dopamine-containing neurons. In the present study, we assessed the effects of Mn on reactive oxygen species (ROS) formation, changes in high-energy phosphates and associated neuronal dysfunctions both in vitro and in vivo. Results from our in vitro study showed a significant (p < 0.01) increase in biomarkers of oxidative damage, F{sub 2}-isoprostanes (F{sub 2}-IsoPs), as well as the depletion of ATP in primary rat cortical neurons following exposure to Mn (500 {mu}M) for 2 h. These effects were protected when neurons were pretreated for 30 min with 100 of an antioxidant, the hydrophilic vitamin E analog, trolox (6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid), or an anti-inflammatory agent, indomethacin. Results from our in vivo study confirmed a significant increase in F{sub 2}-IsoPs levels in conjunction with the progressive spine degeneration and dendritic damage of the striatal medium spiny neurons (MSNs) of mice exposed to Mn (100 mg/kg, s.c.) 24 h. Additionally, pretreatment with vitamin E (100 mg/kg, i.p.) or ibuprofen (140 {mu}g/ml in the drinking water for two weeks) attenuated the Mn-induced increase in cerebral F{sub 2}-IsoPs? and protected the MSNs from dendritic atrophy and dendritic spine loss. Our findings suggest that the mediation of oxidative stress/mitochondrial dysfunction and the control of alterations in biomarkers of oxidative injury, neuroinflammation and synaptodendritic degeneration may provide an effective, multi-pronged therapeutic strategy for protecting dysfunctional

  9. Matricellular proteins in drug delivery: Therapeutic targets, active agents, and therapeutic localization.

    Science.gov (United States)

    Sawyer, Andrew J; Kyriakides, Themis R

    2016-02-01

    Extracellular matrix is composed of a complex array of molecules that together provide structural and functional support to cells. These properties are mainly mediated by the activity of collagenous and elastic fibers, proteoglycans, and proteins such as fibronectin and laminin. ECM composition is tissue-specific and could include matricellular proteins whose primary role is to modulate cell-matrix interactions. In adults, matricellular proteins are primarily expressed during injury, inflammation and disease. Particularly, they are closely associated with the progression and prognosis of cardiovascular and fibrotic diseases, and cancer. This review aims to provide an overview of the potential use of matricellular proteins in drug delivery including the generation of therapeutic agents based on the properties and structures of these proteins as well as their utility as biomarkers for specific diseases. Copyright © 2016 Elsevier B.V. All rights reserved.

  10. Widening and Elaboration of Consecutive Research into Therapeutic Antioxidant Enzyme Derivatives

    Directory of Open Access Journals (Sweden)

    Alexander V. Maksimenko

    2016-01-01

    Full Text Available Undiminishing actuality of enzyme modification for therapeutic purposes has been confirmed by application of modified enzymes in clinical practice and numerous research data on them. Intravenous injection of the superoxide dismutase-chondroitin sulfate-catalase (SOD-CHS-CAT conjugate in preventive and medicative regimes in rats with endotoxin shock induced with a lipopolysaccharide bolus has demonstrated that antioxidant agents not only effectively prevent damage caused by oxidative stress (as believed previously but also can be used for antioxidative stress therapy. The results obtained emphasize the importance of investigation into the pathogenesis of vascular damage and the role of oxidative stress in it. The effects of intravenous medicative injection of SOD-CHS-CAT in a rat model of endotoxin shock have demonstrated a variety in the activity of this conjugate in addition to prevention of NO conversion in peroxynitrite upon interaction with O2∙- superoxide radical. Together with the literature data, these findings offer a prospect for the study of NO-independent therapeutic effects of SOD-CHS-CAT, implying the importance of a better insight into the mechanisms of the conjugate activity in modeled cardiovascular damage involving vasoactive agents other than NO.

  11. SERIES: Genomic instability in cancer Balancing repair and tolerance of DNA damage caused by alkylating agents

    OpenAIRE

    Fu, Dragony; Calvo, Jennifer A.; Samson, Leona D

    2012-01-01

    Alkylating agents comprise a major class of frontline chemotherapeutic drugs that inflict cytotoxic DNA damage as their main mode of action, in addition to collateral mutagenic damage. Numerous cellular pathways, including direct DNA damage reversal, base excision repair (BER), and mismatch repair (MMR) respond to alkylation damage to defend against alkylation-induced cell death or mutation. However, maintaining a proper balance of activity both within and between these pathways is crucial fo...

  12. Review of therapeutic agents for burns pruritus and protocols for management in adult and paediatric patients using the GRADE classification

    Directory of Open Access Journals (Sweden)

    Goutos Ioannis

    2010-10-01

    Full Text Available To review the current evidence on therapeutic agents for burns pruritus and use the Grading of Recommendations, Assessment, Development and Evaluation (GRADE classification to propose therapeutic protocols for adult and paediatric patients. All published interventions for burns pruritus were analysed by a multidisciplinary panel of burns specialists following the GRADE classification to rate individual agents. Following the collation of results and panel discussion, consensus protocols are presented. Twenty-three studies appraising therapeutic agents in the burns literature were identified. The majority of these studies (16 out of 23 are of an observational nature, making an evidence-based approach to defining optimal therapy not feasible. Our multidisciplinary approach employing the GRADE classification recommends the use of antihistamines (cetirizine and cimetidine and gabapentin as the first-line pharmacological agents for both adult and paediatric patients. Ondansetron and loratadine are the second-line medications in our protocols. We additionally recommend a variety of non-pharmacological adjuncts for the perusal of clinicians in order to maximise symptomatic relief in patients troubled with postburn itch. Most studies in the subject area lack sufficient statistical power to dictate a ′gold standard′ treatment agent for burns itch. We encourage clinicians to employ the GRADE system in order to delineate the most appropriate therapeutic approach for burns pruritus until further research elucidates the most efficacious interventions. This widely adopted classification empowers burns clinicians to tailor therapeutic regimens according to current evidence, patient values, risks and resource considerations in different medical environments.

  13. Silibinin, dexamethasone, and doxycycline as potential therapeutic agents for treating vesicant-inflicted ocular injuries

    International Nuclear Information System (INIS)

    Tewari-Singh, Neera; Jain, Anil K.; Inturi, Swetha; Ammar, David A.; Agarwal, Chapla; Tyagi, Puneet; Kompella, Uday B.; Enzenauer, Robert W.; Petrash, J. Mark; Agarwal, Rajesh

    2012-01-01

    There are no effective and approved therapies against devastating ocular injuries caused by vesicating chemical agents sulfur mustard (SM) and nitrogen mustard (NM). Herein, studies were carried out in rabbit corneal cultures to establish relevant ocular injury biomarkers with NM for screening potential efficacious agents in laboratory settings. NM (100 nmol) exposure of the corneas for 2 h (cultured for 24 h), showed increases in epithelial thickness, ulceration, apoptotic cell death, epithelial detachment microbullae formation, and the levels of VEGF, cyclooxygenase-2 (COX-2) and matrix metalloproteinase-9 (MMP-9). Employing these biomarkers, efficacy studies were performed with agent treatments 2 h and every 4 h thereafter, for 24 h following NM exposure. Three agents were evaluated, including prescription drugs dexamethasone (0.1%; anti-inflammatory steroid) and doxycycline (100 nmol; antibiotic and MMP inhibitor) that have been studied earlier for treating vesicant-induced eye injuries. We also examined silibinin (100 μg), a non-toxic natural flavanone found to be effective in treating SM analog-induced skin injuries in our earlier studies. Treatments of doxycycline + dexamethasone, and silibinin were more effective than doxycycline or dexamethasone alone in reversing NM-induced epithelial thickening, microbullae formation, apoptotic cell death, and MMP-9 elevation. However, dexamethasone and silibinin alone were more effective in reversing NM-induced VEGF levels. Doxycycline, dexamethasone and silibinin were all effective in reversing NM-induced COX-2 levels. Apart from therapeutic efficacy of doxycycline and dexamethasone, these results show strong multifunctional efficacy of silibinin in reversing NM-induced ocular injuries, which could help develop effective and safe therapeutics against ocular injuries by vesicants. -- Highlights: ► Established injury biomarkers in rabbit corneal culture with nitrogen mustard (NM) ► This NM model is a cost effective

  14. Silibinin, dexamethasone, and doxycycline as potential therapeutic agents for treating vesicant-inflicted ocular injuries

    Energy Technology Data Exchange (ETDEWEB)

    Tewari-Singh, Neera, E-mail: Neera.Tewari-Singh@ucdenver.edu [Department of Pharmaceutical Sciences, University of Colorado Skaggs School of Pharmacy and Pharmaceutical Sciences, Aurora, CO 80045 (United States); Jain, Anil K., E-mail: Anil.Jain@ucdenver.edu [Department of Pharmaceutical Sciences, University of Colorado Skaggs School of Pharmacy and Pharmaceutical Sciences, Aurora, CO 80045 (United States); Inturi, Swetha, E-mail: Swetha.Inturi@ucdenver.edu [Department of Pharmaceutical Sciences, University of Colorado Skaggs School of Pharmacy and Pharmaceutical Sciences, Aurora, CO 80045 (United States); Ammar, David A., E-mail: David.Ammar@ucdenver.edu [Department of Ophthalmology, University of Colorado School of Medicine, Aurora, CO 80045 (United States); Agarwal, Chapla, E-mail: Chapla.Agarwal@ucdenver.edu [Department of Pharmaceutical Sciences, University of Colorado Skaggs School of Pharmacy and Pharmaceutical Sciences, Aurora, CO 80045 (United States); Tyagi, Puneet, E-mail: Puneet.Tyagi@ucdenver.edu [Department of Pharmaceutical Sciences, University of Colorado Skaggs School of Pharmacy and Pharmaceutical Sciences, Aurora, CO 80045 (United States); Kompella, Uday B., E-mail: Uday.Kompella@ucdenver.edu [Department of Pharmaceutical Sciences, University of Colorado Skaggs School of Pharmacy and Pharmaceutical Sciences, Aurora, CO 80045 (United States); Enzenauer, Robert W., E-mail: Robert.Enzenauer@ucdenver.edu [Department of Ophthalmology, University of Colorado School of Medicine, Aurora, CO 80045 (United States); Petrash, J. Mark, E-mail: Mark.Petrash@ucdenver.edu [Department of Ophthalmology, University of Colorado School of Medicine, Aurora, CO 80045 (United States); Agarwal, Rajesh, E-mail: Rajesh.Agarwal@ucdenver.edu [Department of Pharmaceutical Sciences, University of Colorado Skaggs School of Pharmacy and Pharmaceutical Sciences, Aurora, CO 80045 (United States)

    2012-10-01

    There are no effective and approved therapies against devastating ocular injuries caused by vesicating chemical agents sulfur mustard (SM) and nitrogen mustard (NM). Herein, studies were carried out in rabbit corneal cultures to establish relevant ocular injury biomarkers with NM for screening potential efficacious agents in laboratory settings. NM (100 nmol) exposure of the corneas for 2 h (cultured for 24 h), showed increases in epithelial thickness, ulceration, apoptotic cell death, epithelial detachment microbullae formation, and the levels of VEGF, cyclooxygenase-2 (COX-2) and matrix metalloproteinase-9 (MMP-9). Employing these biomarkers, efficacy studies were performed with agent treatments 2 h and every 4 h thereafter, for 24 h following NM exposure. Three agents were evaluated, including prescription drugs dexamethasone (0.1%; anti-inflammatory steroid) and doxycycline (100 nmol; antibiotic and MMP inhibitor) that have been studied earlier for treating vesicant-induced eye injuries. We also examined silibinin (100 μg), a non-toxic natural flavanone found to be effective in treating SM analog-induced skin injuries in our earlier studies. Treatments of doxycycline + dexamethasone, and silibinin were more effective than doxycycline or dexamethasone alone in reversing NM-induced epithelial thickening, microbullae formation, apoptotic cell death, and MMP-9 elevation. However, dexamethasone and silibinin alone were more effective in reversing NM-induced VEGF levels. Doxycycline, dexamethasone and silibinin were all effective in reversing NM-induced COX-2 levels. Apart from therapeutic efficacy of doxycycline and dexamethasone, these results show strong multifunctional efficacy of silibinin in reversing NM-induced ocular injuries, which could help develop effective and safe therapeutics against ocular injuries by vesicants. -- Highlights: ► Established injury biomarkers in rabbit corneal culture with nitrogen mustard (NM) ► This NM model is a cost effective

  15. Functional polymers as therapeutic agents: concept to market place.

    Science.gov (United States)

    Dhal, Pradeep K; Polomoscanik, Steven C; Avila, Louis Z; Holmes-Farley, S Randall; Miller, Robert J

    2009-11-12

    Biologically active synthetic polymers have received considerable scientific interest and attention in recent years for their potential as promising novel therapeutic agents to treat human diseases. Although a significant amount of research has been carried out involving polymer-linked drugs as targeted and sustained release drug delivery systems and prodrugs, examples on bioactive polymers that exhibit intrinsic therapeutic properties are relatively less. Several appealing characteristics of synthetic polymers including high molecular weight, molecular architecture, and controlled polydispersity can all be utilized to discover a new generation of therapies. For example, high molecular weight bioactive polymers can be restricted to gastrointestinal tract, where they can selectively recognize, bind, and remove target disease causing substances from the body. The appealing features of GI tract restriction and stability in biological environment render these polymeric drugs to be devoid of systemic toxicity that are generally associated with small molecule systemic drugs. The present article highlights recent developments in the rational design and synthesis of appropriate functional polymers that have resulted in a number of promising polymer based therapies and biomaterials, including some marketed products.

  16. Endogenous c-Myc is essential for p53-induced apoptosis in response to DNA damage in vivo

    NARCIS (Netherlands)

    Phesse, T. J.; Myant, K. B.; Cole, A. M.; Ridgway, R. A.; Pearson, H.; Muncan, V.; van den Brink, G. R.; Vousden, K. H.; Sears, R.; Vassilev, L. T.; Clarke, A. R.; Sansom, O. J.

    2014-01-01

    Recent studies have suggested that C-MYC may be an excellent therapeutic cancer target and a number of new agents targeting C-MYC are in preclinical development. Given most therapeutic regimes would combine C-MYC inhibition with genotoxic damage, it is important to assess the importance of C-MYC

  17. Contributions of DNA repair and damage response pathways to the non-linear genotoxic responses of alkylating agents

    Science.gov (United States)

    Klapacz, Joanna; Pottenger, Lynn H.; Engelward, Bevin P.; Heinen, Christopher D.; Johnson, George E.; Clewell, Rebecca A.; Carmichael, Paul L.; Adeleye, Yeyejide; Andersen, Melvin E.

    2016-01-01

    From a risk assessment perspective, DNA-reactive agents are conventionally assumed to have genotoxic risks at all exposure levels, thus applying a linear extrapolation for low-dose responses. New approaches discussed here, including more diverse and sensitive methods for assessing DNA damage and DNA repair, strongly support the existence of measurable regions where genotoxic responses with increasing doses are insignificant relative to control. Model monofunctional alkylating agents have in vitro and in vivo datasets amenable to determination of points of departure (PoDs) for genotoxic effects. A session at the 2013 Society of Toxicology meeting provided an opportunity to survey the progress in understanding the biological basis of empirically-observed PoDs for DNA alkylating agents. Together with the literature published since, this review discusses cellular pathways activated by endogenous and exogenous alkylation DNA damage. Cells have evolved conserved processes that monitor and counteract a spontaneous steady-state level of DNA damage. The ubiquitous network of DNA repair pathways serves as the first line of defense for clearing of the DNA damage and preventing mutation. Other biological pathways discussed here that are activated by genotoxic stress include post-translational activation of cell cycle networks and transcriptional networks for apoptosis/cell death. The interactions of various DNA repair and DNA damage response pathways provide biological bases for the observed PoD behaviors seen with genotoxic compounds. Thus, after formation of DNA adducts, the activation of cellular pathways can lead to the avoidance a mutagenic outcome. The understanding of the cellular mechanisms acting within the low-dose region will serve to better characterize risks from exposures to DNA-reactive agents at environmentally-relevant concentrations. PMID:27036068

  18. Protective effects of antioxidants and anti-inflammatory agents against manganese-induced oxidative damage and neuronal injury

    International Nuclear Information System (INIS)

    Milatovic, Dejan; Gupta, Ramesh C.; Yu, Yingchun; Zaja-Milatovic, Snjezana; Aschner, Michael

    2011-01-01

    Exposure to excessive manganese (Mn) levels leads to neurotoxicity, referred to as manganism, which resembles Parkinson's disease (PD). Manganism is caused by neuronal injury in both cortical and subcortical regions, particularly in the basal ganglia. The basis for the selective neurotoxicity of Mn is not yet fully understood. However, several studies suggest that oxidative damage and inflammatory processes play prominent roles in the degeneration of dopamine-containing neurons. In the present study, we assessed the effects of Mn on reactive oxygen species (ROS) formation, changes in high-energy phosphates and associated neuronal dysfunctions both in vitro and in vivo. Results from our in vitro study showed a significant (p 2 -isoprostanes (F 2 -IsoPs), as well as the depletion of ATP in primary rat cortical neurons following exposure to Mn (500 μM) for 2 h. These effects were protected when neurons were pretreated for 30 min with 100 of an antioxidant, the hydrophilic vitamin E analog, trolox (6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid), or an anti-inflammatory agent, indomethacin. Results from our in vivo study confirmed a significant increase in F 2 -IsoPs levels in conjunction with the progressive spine degeneration and dendritic damage of the striatal medium spiny neurons (MSNs) of mice exposed to Mn (100 mg/kg, s.c.) 24 h. Additionally, pretreatment with vitamin E (100 mg/kg, i.p.) or ibuprofen (140 μg/ml in the drinking water for two weeks) attenuated the Mn-induced increase in cerebral F 2 -IsoPs? and protected the MSNs from dendritic atrophy and dendritic spine loss. Our findings suggest that the mediation of oxidative stress/mitochondrial dysfunction and the control of alterations in biomarkers of oxidative injury, neuroinflammation and synaptodendritic degeneration may provide an effective, multi-pronged therapeutic strategy for protecting dysfunctional dopaminergic transmission and slowing of the progression of Mn-induced neurodegenerative

  19. Production and evaluation of Lutetium-177 maltolate as a possible therapeutic agent

    International Nuclear Information System (INIS)

    Hakimi, A.; Jalilian, A. R.; Bahrami Samani, A.; Ghannadi Maragheh, M.

    2012-01-01

    Development of oral therapeutic radiopharmaceuticals is a new concept in radiopharmacy. Due to the interesting therapeutic properties of 177 Lu and oral bioavailability of maltolate (MAL) metal complexes, 177 Lu-maltolate ( 177 Lu-MAL) was developed as a possible therapeutic compound for ultimate oral administration. The specific activity of 2.6-3 GBq/mg was obtained by irradiation of natural Lu 2 O 3 sample with thermal neutron flux of 4x10 13 n.cm -2 .s -1 for Lu-177. The product was converted into chloride form which was further used for labeling maltol (MAL). At optimized conditions a radiochemical purity of about >99% was obtained for 177 Lu-MAL shown by ITLC (specific activity, 970-1000 Mbq/mmole). The stability of the labeled compound as well as the partition coefficient was determined in the final solution up to 24h. Biodistribution studies of Lu-177 chloride and 177 Lu-MAL were carried out in wild-type rats for post-oral distribution phase data. Lu-MAL is a possible therapeutic agent in human malignancies for the bone palliation therapy so the efficacy of the compound should be tested in various animal models.

  20. Investigation of Acute Toxicity of a Chemical Warfare Agent in Kidneys

    Directory of Open Access Journals (Sweden)

    Turgut Topal

    2007-08-01

    Full Text Available One of the most important chemical warfare agents, sulfur mustard (SM causes crucial acute and chronic toxic effects. Lung, skin, eye and kidneys are the most affected organs. In this work, it was investigated if increased nitric oxide (NO and peroxynitrite are involved in nitrogen mustard (NM induced kidney damage. In this experimen, aminoguanidine (AG as inducible nitric oxide synthase (iNOS inhibitor and ebselen as peroxynitrite scavenger were used. NM administration resulted in important oxidant and antioxidant changes as well as tissue damage in kidneys. Therapeutic agents showed significant protection and reduced oxidant parameteres leading to tissue healing was observed. Results of this study suggest that drugs with similar properties can be used to protect kidney damage caused by NM. [TAF Prev Med Bull. 2007; 6(4: 227-232

  1. Investigation of Acute Toxicity of a Chemical Warfare Agent in Kidneys

    Directory of Open Access Journals (Sweden)

    Turgut Topal

    2007-08-01

    Full Text Available One of the most important chemical warfare agents, sulfur mustard (SM causes crucial acute and chronic toxic effects. Lung, skin, eye and kidneys are the most affected organs. In this work, it was investigated if increased nitric oxide (NO and peroxynitrite are involved in nitrogen mustard (NM induced kidney damage. In this experimen, aminoguanidine (AG as inducible nitric oxide synthase (iNOS inhibitor and ebselen as peroxynitrite scavenger were used. NM administration resulted in important oxidant and antioxidant changes as well as tissue damage in kidneys. Therapeutic agents showed significant protection and reduced oxidant parameteres leading to tissue healing was observed. Results of this study suggest that drugs with similar properties can be used to protect kidney damage caused by NM. [TAF Prev Med Bull 2007; 6(4.000: 227-232

  2. Contributions of DNA repair and damage response pathways to the non-linear genotoxic responses of alkylating agents.

    Science.gov (United States)

    Klapacz, Joanna; Pottenger, Lynn H; Engelward, Bevin P; Heinen, Christopher D; Johnson, George E; Clewell, Rebecca A; Carmichael, Paul L; Adeleye, Yeyejide; Andersen, Melvin E

    2016-01-01

    From a risk assessment perspective, DNA-reactive agents are conventionally assumed to have genotoxic risks at all exposure levels, thus applying a linear extrapolation for low-dose responses. New approaches discussed here, including more diverse and sensitive methods for assessing DNA damage and DNA repair, strongly support the existence of measurable regions where genotoxic responses with increasing doses are insignificant relative to control. Model monofunctional alkylating agents have in vitro and in vivo datasets amenable to determination of points of departure (PoDs) for genotoxic effects. A session at the 2013 Society of Toxicology meeting provided an opportunity to survey the progress in understanding the biological basis of empirically-observed PoDs for DNA alkylating agents. Together with the literature published since, this review discusses cellular pathways activated by endogenous and exogenous alkylation DNA damage. Cells have evolved conserved processes that monitor and counteract a spontaneous steady-state level of DNA damage. The ubiquitous network of DNA repair pathways serves as the first line of defense for clearing of the DNA damage and preventing mutation. Other biological pathways discussed here that are activated by genotoxic stress include post-translational activation of cell cycle networks and transcriptional networks for apoptosis/cell death. The interactions of various DNA repair and DNA damage response pathways provide biological bases for the observed PoD behaviors seen with genotoxic compounds. Thus, after formation of DNA adducts, the activation of cellular pathways can lead to the avoidance of a mutagenic outcome. The understanding of the cellular mechanisms acting within the low-dose region will serve to better characterize risks from exposures to DNA-reactive agents at environmentally-relevant concentrations. Copyright © 2015 Elsevier B.V. All rights reserved.

  3. The responsibility of the agents responsible for environmental damage caused by oil spilling in Brazil; A responsabilidade dos agentes causadores de dano ambiental por derramamento de oleo no Brasil

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2004-07-01

    This essay talks about the responsibility of the agents that cause damage to the environment, both civil liability, as well as criminal and administrative responsibility. It analyzes the most important brazilian juridical rules, emphasizing the National Environmental Politics Law, the Brazilian Federal Republic Constitution and the Environmental Crimes Law. Specially, due to the amount and importance of the oil and gas activities in Brazil, it talks about the environmental responsibility, in the above mentioned fields, related to damage resulting from the Oil and Gas Industry's activities. It focuses the rules that rule this subject in the brazilian juridical system, emphasizing the cases of environmental damage resulting from oil spills in Brazil and the probable juridical consequences to the agents responsible for this damage. (author)

  4. Therapeutic efficacy and mechanism of action of ethamsylate, a long-standing hemostatic agent.

    Science.gov (United States)

    Garay, Ricardo P; Chiavaroli, Carlo; Hannaert, Patrick

    2006-01-01

    Ethamsylate (2,5-dihydroxy-benzene-sulfonate diethylammonium salt) is a synthetic hemostatic drug indicated in cases of capillary bleeding. This review covers more than 40 years of intensive clinical and fundamental research with ethamsylate. First, we summarize the large medical literature concerning its clinical efficacy. Of these, well-controlled clinical trials clearly showed the therapeutic efficacy of ethamsylate in dysfunctional uterine bleeding, with the magnitude of blood-loss reduction being directly proportional to the severity of the menorrhagia. Other well-controlled clinical trials showed therapeutic efficacy of ethamsylate in periventricular hemorrhage in very low birth weight babies and surgical or postsurgical capillary bleeding. Second, we review the numerous investigations performed to elucidate the mechanism of action of ethamsylate. Ethamsylate acts on the first step of hemostasis by improving platelet adhesiveness and restoring capillary resistance. Recent studies showed that ethamsylate promotes P-selectin-dependent, platelet adhesive mechanisms. Finally, we compare ethamsylate with other recent hemostatic agents. It is suggested that the place of ethamsylate as a hemostatic agent is that of a mild but well-tolerated drug, particularly useful in dysfunctional uterine bleeding when contraception is not needed.

  5. Insights into the Antimicrobial Properties of Hepcidins: Advantages and Drawbacks as Potential Therapeutic Agents

    Directory of Open Access Journals (Sweden)

    Lisa Lombardi

    2015-04-01

    Full Text Available The increasing frequency of multi-drug resistant microorganisms has driven research into alternative therapeutic strategies. In this respect, natural antimicrobial peptides (AMPs hold much promise as candidates for the development of novel antibiotics. However, AMPs have some intrinsic drawbacks, such as partial degradation by host proteases or inhibition by host body fluid composition, potential toxicity, and high production costs. This review focuses on the hepcidins, which are peptides produced by the human liver with a known role in iron homeostasis, as well by numerous other organisms (including fish, reptiles, other mammals, and their potential as antibacterial and antifungal agents. Interestingly, the antimicrobial properties of human hepcidins are enhanced at acidic pH, rendering these peptides appealing for the design of new drugs targeting infections that occur in body areas with acidic physiological pH. This review not only considers current research on the direct killing activity of these peptides, but evaluates the potential application of these molecules as coating agents preventing biofilm formation and critically assesses technical obstacles preventing their therapeutic application.

  6. RGD-based strategies for selective delivery of therapeutics and imaging agents to the tumour vasculature

    NARCIS (Netherlands)

    Temming, K; Molema, G; Kok, RJ

    2005-01-01

    During the past decade, RGD-peptides have become a popular tool for the targeting of drugs and imaging agents to a(v)beta(3)-integrin expressing tumour vasculature. RGD-peptides have been introduced by recombinant means into therapeutic proteins and viruses. Chemical means have been applied to

  7. Protective roles of bacterioruberin and intracellular KCl in the resistance of Halobacterium salinarium against DNA-damaging agents

    International Nuclear Information System (INIS)

    Shahmohammadi, H.R.; Asgarani, E.; Terato, Hiroaki; Saito, Takeshi; Ohyama, Yoshihiko; Gekko, Kunihiko; Yamamoto, Osamu; Ide, Hiroshi

    1998-01-01

    Halobacterium salinarium, a member of the extremely halophilic archaebacteria, contains a C 50 -carotenoid namely bacterioruberin. We have previously reported the high resistance of this organism against the lethal actions of DNA-damaging agents including ionizing radiation and ultraviolet light (UV). In this study, we have examined whether bacterioruberin and the highly concentrated salts in this bacterium play protective roles against the lethal actions of ionizing radiation, UV, hydrogen peroxide, and mitomycin-C (MMC). The colourless mutant of H. salinarium deficient in bacterioruberin was more sensitive than the red-pigmented wild-type to all tested DNA-damaging agents except MMC. Circular dichroism (CD) spectra of H. salinarium chromosomal DNA at various concentrations of KCl (0-3.5 M) were similar to that of B-DNA, indicating that no conformational changes occurred as a result of high salt concentrations. However, DNA strand-breaks induced by ionizing radiation were significantly reduced by the presence of either bacterioruberin or concentrated KCl, presumably due to scavenging of free radicals. These results suggest that bacterioruberin and intracellular KCl of H. salinarium protect this organism against the lethal effects of oxidative DNA-damaging agents. (author)

  8. Tetrodotoxin (TTX as a Therapeutic Agent for Pain

    Directory of Open Access Journals (Sweden)

    Cruz Miguel Cendán

    2012-01-01

    Full Text Available Tetrodotoxin (TTX is a potent neurotoxin that blocks voltage-gated sodium channels (VGSCs. VGSCs play a critical role in neuronal function under both physiological and pathological conditions. TTX has been extensively used to functionally characterize VGSCs, which can be classified as TTX-sensitive or TTX-resistant channels according to their sensitivity to this toxin. Alterations in the expression and/or function of some specific TTX-sensitive VGSCs have been implicated in a number of chronic pain conditions. The administration of TTX at doses below those that interfere with the generation and conduction of action potentials in normal (non-injured nerves has been used in humans and experimental animals under different pain conditions. These data indicate a role for TTX as a potential therapeutic agent for pain. This review focuses on the preclinical and clinical evidence supporting a potential analgesic role for TTX. In addition, the contribution of specific TTX-sensitive VGSCs to pain is reviewed.

  9. Evolution of and perspectives on therapeutic approaches to nerve agent poisoning.

    Science.gov (United States)

    Masson, Patrick

    2011-09-25

    After more than 70 years of considerable efforts, research on medical defense against nerve agents has come to a standstill. Major progress in medical countermeasures was achieved between the 50s and 70s with the development of anticholinergic drugs and carbamate-based pretreatment, the introduction of pyridinium oximes as antidotes, and benzodiazepines in emergency treatments. These drugs ensure good protection of the peripheral nervous system and mitigate the acute effects of exposure to lethal doses of nerve agents. However, pyridostigmine and cholinesterase reactivators currently used in the armed forces do not protect/reactivate central acetylcholinesterases. Moreover, other drugs used are not sufficiently effective in protecting the central nervous system against seizures, irreversible brain damages and long-term sequelae of nerve agent poisoning.New developments of medical counter-measures focus on: (a) detoxification of organophosphorus molecules before they react with acetylcholinesterase and other physiological targets by administration of stoichiometric or catalytic scavengers; (b) protection and reactivation of central acetylcholinesterases, and (c) improvement of neuroprotection following delayed therapy.Future developments will aim at treatment of acute and long-term effects of low level exposure to nerve agents, research on alternative routes for optimizing drug delivery, and therapies. Though gene therapy for in situ generation of bioscavengers, and cell therapy based on neural progenitor engraftment for neuronal regeneration have been successfully explored, more studies are needed before practical medical applications can be made of these new approaches. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  10. Cellular Responses to Cisplatin-Induced DNA Damage

    Directory of Open Access Journals (Sweden)

    Alakananda Basu

    2010-01-01

    Full Text Available Cisplatin is one of the most effective anticancer agents widely used in the treatment of solid tumors. It is generally considered as a cytotoxic drug which kills cancer cells by damaging DNA and inhibiting DNA synthesis. How cells respond to cisplatin-induced DNA damage plays a critical role in deciding cisplatin sensitivity. Cisplatin-induced DNA damage activates various signaling pathways to prevent or promote cell death. This paper summarizes our current understandings regarding the mechanisms by which cisplatin induces cell death and the bases of cisplatin resistance. We have discussed various steps, including the entry of cisplatin inside cells, DNA repair, drug detoxification, DNA damage response, and regulation of cisplatin-induced apoptosis by protein kinases. An understanding of how various signaling pathways regulate cisplatin-induced cell death should aid in the development of more effective therapeutic strategies for the treatment of cancer.

  11. Cell targeting peptides as smart ligands for targeting of therapeutic or diagnostic agents: a systematic review.

    Science.gov (United States)

    Mousavizadeh, Ali; Jabbari, Ali; Akrami, Mohammad; Bardania, Hassan

    2017-10-01

    Cell targeting peptides (CTP) are small peptides which have high affinity and specificity to a cell or tissue targets. They are typically identified by using phage display and chemical synthetic peptide library methods. CTPs have attracted considerable attention as a new class of ligands to delivery specifically therapeutic and diagnostic agents, because of the fact they have several advantages including easy synthesis, smaller physical sizes, lower immunogenicity and cytotoxicity and their simple and better conjugation to nano-carriers and therapeutic or diagnostic agents compared to conventional antibodies. In this systematic review, we will focus on the basic concepts concerning the use of cell-targeting peptides (CTPs), following the approaches of selecting them from peptide libraries. We discuss several developed strategies for cell-specific delivery of different cargos by CTPs, which are designed for drug delivery and diagnostic applications. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. Anti-SEMA3A Antibody: A Novel Therapeutic Agent to Suppress GBM Tumor Growth.

    Science.gov (United States)

    Lee, Jaehyun; Shin, Yong Jae; Lee, Kyoungmin; Cho, Hee Jin; Sa, Jason K; Lee, Sang-Yun; Kim, Seok-Hyung; Lee, Jeongwu; Yoon, Yeup; Nam, Do-Hyun

    2017-11-10

    Glioblastoma (GBM) is classified as one of the most aggressive and lethal brain tumor. Great strides have been made in understanding the genomic and molecular underpinnings of GBM, which translated into development of new therapeutic approaches to combat such deadly disease. However, there are only few therapeutic agents that can effectively inhibit GBM invasion in a clinical framework. In an effort to address such challenges, we have generated anti-SEMA3A monoclonal antibody as a potential therapeutic antibody against GBM progression. We employed public glioma datasets, Repository of Molecular Brain Neoplasia Data and The Cancer Genome Atlas, to analyze SEMA3A mRNA expression in human GBM specimens. We also evaluated for protein expression level of SEMA3A via tissue microarray (TMA) analysis. Cell migration and proliferation kinetics were assessed in various GBM patient-derived cells (PDCs) and U87-MG cell-line for SEMA3A antibody efficacy. GBM patient-derived xenograft (PDX) models were generated to evaluate tumor inhibitory effect of anti-SEMA3A antibody in vivo. By combining bioinformatics and TMA analysis, we discovered that SEMA3A is highly expressed in human GBM specimens compared to non-neoplastic tissues. We developed three different anti-SEMA3A antibodies, in fully human IgG form, through screening phage-displayed synthetic antibody library using a classical panning method. Neutralization of SEMA3A significantly reduced migration and proliferation capabilities of PDCs and U87-MG cell-line in vitro. In PDX models, treatment with anti-SEMA3A antibody exhibited notable tumor inhibitory effect through down-regulation of cellular proliferative kinetics and tumor-associated macrophages recruitment. In present study, we demonstrated tumor inhibitory effect of SEMA3A antibody in GBM progression and present its potential relevance as a therapeutic agent in a clinical framework.

  13. Small Scaffolds, Big Potential: Developing Miniature Proteins as Therapeutic Agents.

    Science.gov (United States)

    Holub, Justin M

    2017-09-01

    Preclinical Research Miniature proteins are a class of oligopeptide characterized by their short sequence lengths and ability to adopt well-folded, three-dimensional structures. Because of their biomimetic nature and synthetic tractability, miniature proteins have been used to study a range of biochemical processes including fast protein folding, signal transduction, catalysis and molecular transport. Recently, miniature proteins have been gaining traction as potential therapeutic agents because their small size and ability to fold into defined tertiary structures facilitates their development as protein-based drugs. This research overview discusses emerging developments involving the use of miniature proteins as scaffolds to design novel therapeutics for the treatment and study of human disease. Specifically, this review will explore strategies to: (i) stabilize miniature protein tertiary structure; (ii) optimize biomolecular recognition by grafting functional epitopes onto miniature protein scaffolds; and (iii) enhance cytosolic delivery of miniature proteins through the use of cationic motifs that facilitate endosomal escape. These objectives are discussed not only to address challenges in developing effective miniature protein-based drugs, but also to highlight the tremendous potential miniature proteins hold for combating and understanding human disease. Drug Dev Res 78 : 268-282, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  14. Current progress and future perspectives in the development of anti-polo-like kinase 1 therapeutic agents [version 1; referees: 4 approved

    Directory of Open Access Journals (Sweden)

    Jung-Eun Park

    2017-06-01

    Full Text Available Although significant levels of side effects are often associated with their use, microtubule-directed agents that primarily target fast-growing mitotic cells have been considered to be some of the most effective anti-cancer therapeutics. With the hope of developing new-generation anti-mitotic agents with reduced side effects and enhanced tumor specificity, researchers have targeted various proteins whose functions are critically required for mitotic progression. As one of the highly attractive mitotic targets, polo-like kinase 1 (Plk1 has been the subject of an extensive effort for anti-cancer drug discovery. To date, a variety of anti-Plk1 agents have been developed, and several of them are presently in clinical trials. Here, we will discuss the current status of generating anti-Plk1 agents as well as future strategies for designing and developing more efficacious anti-Plk1 therapeutics.

  15. 77 FR 62521 - Prospective Grant of Exclusive License: The Development of Therapeutic Agents for the Treatment...

    Science.gov (United States)

    2012-10-15

    ... interleukin-10 (IL-10) inhibitor as a dual-biologic therapy to treat metastatic breast cancer, or ii) incorporating a p53 isoform antisense oligonucleotide as a single biologic therapy to treat T- cell lymphoma... Exclusive License: The Development of Therapeutic Agents for the Treatment of Metastatic Breast Cancer and T...

  16. Paclitaxel-induced epithelial damage and ectopic MMP-13 expression promotes neurotoxicity in zebrafish.

    Science.gov (United States)

    Lisse, Thomas S; Middleton, Leah J; Pellegrini, Adriana D; Martin, Paige B; Spaulding, Emily L; Lopes, Olivia; Brochu, Elizabeth A; Carter, Erin V; Waldron, Ashley; Rieger, Sandra

    2016-04-12

    Paclitaxel is a microtubule-stabilizing chemotherapeutic agent that is widely used in cancer treatment and in a number of curative and palliative regimens. Despite its beneficial effects on cancer, paclitaxel also damages healthy tissues, most prominently the peripheral sensory nervous system. The mechanisms leading to paclitaxel-induced peripheral neuropathy remain elusive, and therapies that prevent or alleviate this condition are not available. We established a zebrafish in vivo model to study the underlying mechanisms and to identify pharmacological agents that may be developed into therapeutics. Both adult and larval zebrafish displayed signs of paclitaxel neurotoxicity, including sensory axon degeneration and the loss of touch response in the distal caudal fin. Intriguingly, studies in zebrafish larvae showed that paclitaxel rapidly promotes epithelial damage and decreased mechanical stress resistance of the skin before induction of axon degeneration. Moreover, injured paclitaxel-treated zebrafish skin and scratch-wounded human keratinocytes (HEK001) display reduced healing capacity. Epithelial damage correlated with rapid accumulation of fluorescein-conjugated paclitaxel in epidermal basal keratinocytes, but not axons, and up-regulation of matrix-metalloproteinase 13 (MMP-13, collagenase 3) in the skin. Pharmacological inhibition of MMP-13, in contrast, largely rescued paclitaxel-induced epithelial damage and neurotoxicity, whereas MMP-13 overexpression in zebrafish embryos rendered the skin vulnerable to injury under mechanical stress conditions. Thus, our studies provide evidence that the epidermis plays a critical role in this condition, and we provide a previously unidentified candidate for therapeutic interventions.

  17. Cross-sensitivity of X-ray-hypersensitive cells derived from LEC strain rats to DNA-damaging agents

    International Nuclear Information System (INIS)

    Okui, T.; Endoh, D.; Arai, S.; Isogai, E.; Hayashi, M.

    1996-01-01

    The cross-sensitivity of X-ray-hypersensitive lung fibroblasts from LEC strain (LEC) rats to other DNA-damaging agents was examined. The LEC cells were 2- to 3-fold more sensitive to bleomycin (BLM) that induces DNA double-strand breaks, and to a cross-linking agent, mitomycin C, than the cells from WKAH strain (WKAH) rats, while they were slightly sensitive to alkylating agents, ethyl nitrosourea and N-methyl-N'-nitro-N-nitrosoguanidine, but not to UV-irradiation. Although no difference was observed in the initial yields of DNA double-strand breaks induced by BLM between LEC and WKAH cells, the repair process of DNA double-strand breaks was significantly slower in LEC cells than in WKAH cells

  18. Chemotherapeutic Drugs: DNA Damage and Repair in Glioblastoma.

    Science.gov (United States)

    Annovazzi, Laura; Mellai, Marta; Schiffer, Davide

    2017-05-26

    Despite improvements in therapeutic strategies, glioblastoma (GB) remains one of the most lethal cancers. The presence of the blood-brain barrier, the infiltrative nature of the tumor and several resistance mechanisms account for the failure of current treatments. Distinct DNA repair pathways can neutralize the cytotoxicity of chemo- and radio-therapeutic agents, driving resistance and tumor relapse. It seems that a subpopulation of stem-like cells, indicated as glioma stem cells (GSCs), is responsible for tumor initiation, maintenance and recurrence and they appear to be more resistant owing to their enhanced DNA repair capacity. Recently, attention has been focused on the pivotal role of the DNA damage response (DDR) in tumorigenesis and in the modulation of therapeutic treatment effects. In this review, we try to summarize the knowledge concerning the main molecular mechanisms involved in the removal of genotoxic lesions caused by alkylating agents, emphasizing the role of GSCs. Beside their increased DNA repair capacity in comparison with non-stem tumor cells, GSCs show a constitutive checkpoint expression that enables them to survive to treatments in a quiescent, non-proliferative state. The targeted inhibition of checkpoint/repair factors of DDR can contribute to eradicate the GSC population and can have a great potential therapeutic impact aiming at sensitizing malignant gliomas to treatments, improving the overall survival of patients.

  19. Targeting Potassium Channels for Increasing Delivery of Imaging Agents and Therapeutics to Brain Tumors

    OpenAIRE

    Nagendra Sanyasihally Ningaraj; Divya eKhaitan

    2013-01-01

    Every year in the US, 20,000 new primary and nearly 200,000 metastatic brain tumor cases are reported. The cerebral microvessels/ capillaries that form the blood–brain barrier (BBB) not only protect the brain from toxic agents in the blood but also pose a significant hindrance to the delivery of small and large therapeutic molecules. Different strategies have been employed to circumvent the physiological barrier posed by blood-brain tumor barrier (BTB). Studies in our laboratory have identifi...

  20. Vascular-targeted photodynamic therapy with BF2-chelated Tetraaryl-Azadipyrromethene agents: a multi-modality molecular imaging approach to therapeutic assessment.

    LENUS (Irish Health Repository)

    Byrne, A T

    2009-11-03

    Photodynamic therapy (PDT) is a treatment modality for a range of diseases including cancer. The BF(2)-chelated tetraaryl-azadipyrromethenes (ADPMs) are an emerging class of non-porphyrin PDT agent, which have previously shown excellent photochemical and photophysical properties for therapeutic application. Herein, in vivo efficacy and mechanism of action studies have been completed for the lead agent, ADMP06.

  1. Oxidative phosphorylation-dependent regulation of cancer cell apoptosis in response to anticancer agents.

    Science.gov (United States)

    Yadav, N; Kumar, S; Marlowe, T; Chaudhary, A K; Kumar, R; Wang, J; O'Malley, J; Boland, P M; Jayanthi, S; Kumar, T K S; Yadava, N; Chandra, D

    2015-11-05

    Cancer cells tend to develop resistance to various types of anticancer agents, whether they adopt similar or distinct mechanisms to evade cell death in response to a broad spectrum of cancer therapeutics is not fully defined. Current study concludes that DNA-damaging agents (etoposide and doxorubicin), ER stressor (thapsigargin), and histone deacetylase inhibitor (apicidin) target oxidative phosphorylation (OXPHOS) for apoptosis induction, whereas other anticancer agents including staurosporine, taxol, and sorafenib induce apoptosis in an OXPHOS-independent manner. DNA-damaging agents promoted mitochondrial biogenesis accompanied by increased accumulation of cellular and mitochondrial ROS, mitochondrial protein-folding machinery, and mitochondrial unfolded protein response. Induction of mitochondrial biogenesis occurred in a caspase activation-independent mechanism but was reduced by autophagy inhibition and p53-deficiency. Abrogation of complex-I blocked DNA-damage-induced caspase activation and apoptosis, whereas inhibition of complex-II or a combined deficiency of OXPHOS complexes I, III, IV, and V due to impaired mitochondrial protein synthesis did not modulate caspase activity. Mechanistic analysis revealed that inhibition of caspase activation in response to anticancer agents associates with decreased release of mitochondrial cytochrome c in complex-I-deficient cells compared with wild type (WT) cells. Gross OXPHOS deficiencies promoted increased release of apoptosis-inducing factor from mitochondria compared with WT or complex-I-deficient cells, suggesting that cells harboring defective OXPHOS trigger caspase-dependent as well as caspase-independent apoptosis in response to anticancer agents. Interestingly, DNA-damaging agent doxorubicin showed strong binding to mitochondria, which was disrupted by complex-I-deficiency but not by complex-II-deficiency. Thapsigargin-induced caspase activation was reduced upon abrogation of complex-I or gross OXPHOS deficiency

  2. Self-healing of low-velocity impact damage in glass fabric/epoxy composites using an epoxy–mercaptan healing agent

    International Nuclear Information System (INIS)

    Yuan, Yan Chao; Qin, Shi Xiang; Ye, Yueping; Chen, Haibin; Wu, Jingshen; Rong, Min Zhi; Zhang, Ming Qiu; Yang, Gui Cheng

    2011-01-01

    Self-healing woven glass fabric-reinforced epoxy composite laminates were made by embedding epoxy- and mercaptan-loaded microcapsules. After being subjected to low-velocity impact, the laminates were able to heal the damage in an autonomic way at room temperature. The healing-induced reduction in the damaged areas was visualized using a scanning acoustic microscope. The rate of damage area reduction, which is closely related to the effect of crack rehabilitation and mechanical recovery, is a function of impact energy, content and size of the healing microcapsules. Minor damage, such as microcracks in the matrix, can be completely repaired by the healing system without manual intervention, including external pressure. Microcapsules with larger size and/or higher concentration are propitious for delivering more healing agent to cracked portions, while imposition of lateral pressure on damaged specimens forces the separated faces to approach each other. Both can improve the rate of damage area reduction in the case of severe damage

  3. Frontiers in nano-therapeutics

    CERN Document Server

    Tasnim, Nishat; Sai Krishna, Katla; Kalagara, Sudhakar; Narayan, Mahesh; Noveron, Juan C; Joddar, Binata

    2017-01-01

    This brief highlights recent research advances in the area of nano-therapeutics. Nanotechnology holds immense potential for application in a wide range of biological and engineering applications such as molecular sensors for disease diagnosis, therapeutic agents for the treatment of diseases, a vehicle for delivering therapeutics and imaging agents for theranostic applications, both in-vitro and in-vivo. The brief is grouped into the following sections namely, A) Discrete Nanosystems ; B) Anisotropic Nanoparticles; C) Nano-films/coated/layered and D) Nano-composites.

  4. Protective effects of antioxidants and anti-inflammatory agents against manganese-induced oxidative damage and neuronal injury.

    Science.gov (United States)

    Milatovic, Dejan; Gupta, Ramesh C; Yu, Yingchun; Zaja-Milatovic, Snjezana; Aschner, Michael

    2011-11-01

    Exposure to excessive manganese (Mn) levels leads to neurotoxicity, referred to as manganism, which resembles Parkinson's disease (PD). Manganism is caused by neuronal injury in both cortical and subcortical regions, particularly in the basal ganglia. The basis for the selective neurotoxicity of Mn is not yet fully understood. However, several studies suggest that oxidative damage and inflammatory processes play prominent roles in the degeneration of dopamine-containing neurons. In the present study, we assessed the effects of Mn on reactive oxygen species (ROS) formation, changes in high-energy phosphates and associated neuronal dysfunctions both in vitro and in vivo. Results from our in vitro study showed a significant (pprotected when neurons were pretreated for 30 min with 100 of an antioxidant, the hydrophilic vitamin E analog, trolox (6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid), or an anti-inflammatory agent, indomethacin. Results from our in vivo study confirmed a significant increase in F(2)-IsoPs levels in conjunction with the progressive spine degeneration and dendritic damage of the striatal medium spiny neurons (MSNs) of mice exposed to Mn (100mg/kg, s.c.) 24h. Additionally, pretreatment with vitamin E (100mg/kg, i.p.) or ibuprofen (140 μg/ml in the drinking water for two weeks) attenuated the Mn-induced increase in cerebral F(2)-IsoPs? and protected the MSNs from dendritic atrophy and dendritic spine loss. Our findings suggest that the mediation of oxidative stress/mitochondrial dysfunction and the control of alterations in biomarkers of oxidative injury, neuroinflammation and synaptodendritic degeneration may provide an effective, multi-pronged therapeutic strategy for protecting dysfunctional dopaminergic transmission and slowing of the progression of Mn-induced neurodegenerative processes. Copyright © 2011 Elsevier Inc. All rights reserved.

  5. Cooperative biological effects between ionizing radiation and other physical and chemical agents.

    Science.gov (United States)

    Manti, Lorenzo; D'Arco, Annalisa

    2010-01-01

    Exposure to ionizing radiation (IR), at environmentally and therapeutically relevant doses or as a result of diagnostics or accidents, causes cyto- and genotoxic damage. However, exposure to IR alone is a rare event as it occurs in spatial and temporal combination with several physico-chemical agents. Some of these are of known noxiousness, as is the case with chemical compounds at high dose, hence additive/synergistic effects can be expected or have been demonstrated. Conversely, the cellular toxicity of other agents, such as non-ionizing electromagnetic fields (EMFs), is only presumed and their short- and long-term cooperation on IR-induced damage remains undetermined. In this review, we shall examine evidence in support of the interplay between spatially and/or temporally related environmentally relevant stressors. In vitro or animal-based studies as well as epidemiological surveys have generally examined the combined action of no more than a couple of known or potentially DNA-damaging agents. Moreover, most existing research mainly focused on short-term effects of combined exposures. Hence, it is important that quantitative research addresses the issue of the possible cooperation between chronic exposure to environmental trace contaminants and exposure to EMFs, examining not only the modulation of damage acutely induced by IR but also long-term genome stability. 2010 Elsevier B.V. All rights reserved.

  6. New Therapeutic Agent against Arterial Thrombosis: An Iridium(III-Derived Organometallic Compound

    Directory of Open Access Journals (Sweden)

    Chih-Wei Hsia

    2017-12-01

    Full Text Available Platelet activation plays a major role in cardio and cerebrovascular diseases, and cancer progression. Disruption of platelet activation represents an attractive therapeutic target for reducing the bidirectional cross talk between platelets and tumor cells. Platinum (Pt compounds have been used for treating cancer. Hence, replacing Pt with iridium (Ir is considered a potential alternative. We recently developed an Ir(III-derived complex, [Ir(Cp*1-(2-pyridyl-3-(2-hydroxyphenylimidazo[1,5-a]pyridine Cl]BF4 (Ir-11, which exhibited strong antiplatelet activity; hence, we assessed the therapeutic potential of Ir-11 against arterial thrombosis. In collagen-activated platelets, Ir-11 inhibited platelet aggregation, adenosine triphosphate (ATP release, intracellular Ca2+ mobilization, P-selectin expression, and OH· formation, as well as the phosphorylation of phospholipase Cγ2 (PLCγ2, protein kinase C (PKC, mitogen-activated protein kinases (MAPKs, and Akt. Neither the adenylate cyclase inhibitor nor the guanylate cyclase inhibitor reversed the Ir-11-mediated antiplatelet effects. In experimental mice, Ir-11 prolonged the bleeding time and reduced mortality associated with acute pulmonary thromboembolism. Ir-11 plays a crucial role by inhibiting platelet activation through the inhibition of the PLCγ2–PKC cascade, and the subsequent suppression of Akt and MAPK activation, ultimately inhibiting platelet aggregation. Therefore, Ir-11 can be considered a new therapeutic agent against either arterial thrombosis or the bidirectional cross talk between platelets and tumor cells.

  7. Quantitative Analyses of Synergistic Responses between Cannabidiol and DNA-Damaging Agents on the Proliferation and Viability of Glioblastoma and Neural Progenitor Cells in Culture

    OpenAIRE

    Deng, Liting; Ng, Lindsay; Ozawa, Tatsuya; Stella, Nephi

    2017-01-01

    Evidence suggests that the nonpsychotropic cannabis-derived compound, cannabidiol (CBD), has antineoplastic activity in multiple types of cancers, including glioblastoma multiforme (GBM). DNA-damaging agents remain the main standard of care treatment available for patients diagnosed with GBM. Here we studied the antiproliferative and cell-killing activity of CBD alone and in combination with DNA-damaging agents (temozolomide, carmustine, or cisplatin) in several human GBM cell lines and in mo...

  8. Development and biological evaluation of {sup 90}Y-BPAMD as a novel bone seeking therapeutic agent

    Energy Technology Data Exchange (ETDEWEB)

    Rabiei, Ali; Shamsaei, Mojtaba [Amir Kabir University of Technology, Tehran (Iran, Islamic Republic of). Energy Engineering and Physics Dept.; Yousefnia, Hassan; Zolghadri, Samaneh; Jalilian, Amir Reza [Nuclear Science and Technology Research Institute (NSTRI), Tehran (Iran, Islamic Republic of); Enayati, Razieh [Islamic Azad Univ. (IAU), Tehran (Iran, Islamic Republic of). Faculty of Engineering

    2016-07-01

    Nowadays, the bone-seeking radiopharmaceuticals play an important role in the treatment of the bone-related pathologies. Whereas various phosphonate ligands have already been identified, a DOTA-based bisphosphonate, 4-{[(bis(phosphonomethyl))carbamoyl]methyl}-7,10-bis(carboxymethyl) -1,4,7,10-tetraazacyclododec-1-yl (BPAMD) with better characteristics has recently been synthesized. In this study, {sup 90}Y-BPAMD was developed with radiochemical purity >98% and the specific activity of 3.52 TBq/mmol in the optimized conditions as a new bone-seeking therapeutic agent. The complex demonstrated significant stability at room temperature and in human serum even after 48 h. At even low amount of hydroxyapatite (5 mg), more than 90% binding to hydroxyapatite was observed. Biodistribution studies after injection of the complex into the Syrian rats showed major accumulation of the labelled compound in the bone tissue and an insignificant uptake in the other organs all the times after injection. Generally, {sup 90}Y-BPAMD demonstrated interesting characteristics compared to the other {sup 90}Y bone-seeking agents and even {sup 166}Ho-BPAMD, and can be considered as a new bone-seeking candidate for therapeutic applications.

  9. Sensitization of human cells by inhibitors of DNA synthesis following the action of DNA-damaging agents

    Energy Technology Data Exchange (ETDEWEB)

    Filatov, M.V.; Noskin, L.A. (Leningrad Inst. of Nuclear Physics, Gatchina (USSR))

    1983-08-01

    Inhibitors of DNA synthesis 1-..beta..-arabinofuranosylcytosine (Ac) and hydroxyurea (Hu) taken together drastically sensitized human cells to the killing effect of DNA-damaging agents. For UV-irradiation this sensitization depended on the cells' ability for excision repair. By using viscoelastometric methods of measurement of double-strand breaks (DSB) in the genome, it was established that the first DSB were generated after incubation of the damaged cells in the mixture of inhibitors at about the same dose when sensitization appeared. A scheme is proposed to describe molecular events associated with the phenomenon studied. 35 refs.

  10. Parainfluenza Virus Infection Sensitizes Cancer Cells to DNA-Damaging Agents: Implications for Oncolytic Virus Therapy.

    Science.gov (United States)

    Fox, Candace R; Parks, Griffith D

    2018-04-01

    A parainfluenza virus 5 (PIV5) with mutations in the P/V gene (P/V-CPI - ) is restricted for spread in normal cells but not in cancer cells in vitro and is effective at reducing tumor burdens in mouse model systems. Here we show that P/V-CPI - infection of HEp-2 human laryngeal cancer cells results in the majority of the cells dying, but unexpectedly, over time, there is an emergence of a population of cells that survive as P/V-CPI - persistently infected (PI) cells. P/V-CPI - PI cells had elevated levels of basal caspase activation, and viability was highly dependent on the activity of cellular inhibitor-of-apoptosis proteins (IAPs) such as Survivin and XIAP. In challenge experiments with external inducers of apoptosis, PI cells were more sensitive to cisplatin-induced DNA damage and cell death. This increased cisplatin sensitivity correlated with defects in DNA damage signaling pathways such as phosphorylation of Chk1 and translocation of damage-specific DNA binding protein 1 (DDB1) to the nucleus. Cisplatin-induced killing of PI cells was sensitive to the inhibition of wild-type (WT) p53-inducible protein 1 (WIP1), a phosphatase which acts to terminate DNA damage signaling pathways. A similar sensitivity to cisplatin was seen with cells during acute infection with P/V-CPI - as well as during acute infections with WT PIV5 and the related virus human parainfluenza virus type 2 (hPIV2). Our results have general implications for the design of safer paramyxovirus-based vectors that cannot establish PI as well as the potential for combining chemotherapy with oncolytic RNA virus vectors. IMPORTANCE There is intense interest in developing oncolytic viral vectors with increased potency against cancer cells, particularly those cancer cells that have gained resistance to chemotherapies. We have found that infection with cytoplasmically replicating parainfluenza virus can result in increases in the killing of cancer cells by agents that induce DNA damage, and this is linked

  11. Therapeutic Strategies to Enhance the Anticancer Efficacy of Histone Deacetylase Inhibitors

    Directory of Open Access Journals (Sweden)

    Claudia P. Miller

    2011-01-01

    Full Text Available Histone acetylation is a posttranslational modification that plays a role in regulating gene expression. More recently, other nonhistone proteins have been identified to be acetylated which can regulate their function, stability, localization, or interaction with other molecules. Modulating acetylation with histone deacetylase inhibitors (HDACi has been validated to have anticancer effects in preclinical and clinical cancer models. This has led to development and approval of the first HDACi, vorinostat, for the treatment of cutaneous T cell lymphoma. However, to date, targeting acetylation with HDACi as a monotherapy has shown modest activity against other cancers. To improve their efficacy, HDACi have been paired with other antitumor agents. Here, we discuss several combination therapies, highlighting various epigenetic drugs, ROS-generating agents, proteasome inhibitors, and DNA-damaging compounds that together may provide a therapeutic advantage over single-agent strategies.

  12. Trans-differentiation of neural stem cells: a therapeutic mechanism against the radiation induced brain damage.

    Directory of Open Access Journals (Sweden)

    Kyeung Min Joo

    Full Text Available Radiation therapy is an indispensable therapeutic modality for various brain diseases. Though endogenous neural stem cells (NSCs would provide regenerative potential, many patients nevertheless suffer from radiation-induced brain damage. Accordingly, we tested beneficial effects of exogenous NSC supplementation using in vivo mouse models that received whole brain irradiation. Systemic supplementation of primarily cultured mouse fetal NSCs inhibited radiation-induced brain atrophy and thereby preserved brain functions such as short-term memory. Transplanted NSCs migrated to the irradiated brain and differentiated into neurons, astrocytes, or oligodendrocytes. In addition, neurotrophic factors such as NGF were significantly increased in the brain by NSCs, indicating that both paracrine and replacement effects could be the therapeutic mechanisms of NSCs. Interestingly, NSCs also differentiated into brain endothelial cells, which was accompanied by the restoration the cerebral blood flow that was reduced from the irradiation. Inhibition of the VEGF signaling reduced the migration and trans-differentiation of NSCs. Therefore, trans-differentiation of NSCs into brain endothelial cells by the VEGF signaling and the consequential restoration of the cerebral blood flow would also be one of the therapeutic mechanisms of NSCs. In summary, our data demonstrate that exogenous NSC supplementation could prevent radiation-induced functional loss of the brain. Therefore, successful combination of brain radiation therapy and NSC supplementation would provide a highly promising therapeutic option for patients with various brain diseases.

  13. 166Ho-HA evaluation as therapeutic agent for rheumatoid arthritis treatment

    International Nuclear Information System (INIS)

    Chandia, M.C.; Errazu, X.C.; Pinto, L.N.; Godoy, N.O.; Avila, M.J.; Mendoza, P.; Mendoza, J.; Jofre, J.; Sirraalta, P.

    2002-01-01

    Aim: Rheumatoid arthritis is a limiting disease having, among its pathological features, the inflammation of synovial tissue with progressive and later destruction of the articulation. This leads to joint deformation and loss of its function, generating pain and reducing the mobility of the affected articulation. The aim was to evaluate 166 Ho-Hydroxyapatite ( 166 Ho-HA) as potential radiopharmaceutical for the symptomatic treatment of chronic and acute arthritis. Materials and Methods: Holmiun-166 was produced by irradiation of Ho 2 O 3 at La Reina Research Reactor, Nuclear Chilean Energy Commission. Hydroxyapatite was in-house synthesized. Its labelling and quality controls follows the internationally accepted procedures. An antigen's arthritis was induced to eight New Zealand rabbits with the 166 Ho-HA radiochemical being administered thereafter in two dosage modalities (single and double). The compound therapeutic efficiency was evaluated based upon clinical improvement and images from the inflamated articulation using 67 Ga citrate before and after 166 Ho-HA injection. Results: The radiochemical purity of the inoculated compound was greater than 98% as measured under sterility conditions. Clinically, an inflammation reduction (2 cm), appetite improvement and general well being was observed. The 166 Ho-HA distribution and localization was monitored using gamma camera images taken at 4 and 24 h. There was no evidence of extra articular leakage. From the 67 Ga citrate imaging, the acute group shows an overall improvement of well being corresponding to a lesser uptake at the inflamated articulation, regarding to the chronic group. The 166 Ho-HA double doses, compared to the single doses, suggest a reduced uptake of 67 Ga citrate at the inflamated tissue, meaning an increased therapeutic effect. Conclusions: 166 Ho-HA is useful as therapeutic agent for the symptomatic treatment of rheumatoid arthritis as shown by imaging and clinical examination

  14. 166 Ho-HA Evaluation as therapeutic agent for rheumatoid arthritis treatment

    International Nuclear Information System (INIS)

    Chandia, M; Errazu, X; Mendoza, P; Troncoso, F; Jofre, J; Sierralta, P

    2003-01-01

    Aim: Rheumatoid arthritis is a limiting disease having, among its pathological features, the inflammation of synovial tissue with progressive and later destruction of the articulation. This lead to joint deformation and loss of its function, generating pain and reducing the mobility of the affected articulation. The aim was to evaluate 166 Ho-Hydroxyapatite ( 166 Ho-HA) as potential radiopharmaceutical for the syntomatic treatment of chronic and acute arthritis Materials and Methods: 166 Holmiun was produced by irradiation of Ho 2 O 3 at La Reina Research Reactor, Nuclear Chilean Energy Commission. Hydroxyapatite was in-house synthetized. Its labelling and quality controls follows the internationally accepted procedures. An antigen arthritis was induced to eight New Zealand rabbits with the 166 Ho-HA radiochemical being administred thereafter in two dosage modalities (single and double). The compound therapeutic efficiency was evaluated based upon clinical improvement and images from the inflamated articulation using 67 Ga citrate before and after 166 Ho-HA injection. Results: The radiochemical purity of the innoculated compound was greater than 98% as measured under sterility conditions. Clinically, an inflamation reduction (2 cm), appetite improvement and general well being was observed. The 166 Ho-HA distribution and localization was monitored using gamma camera images taken at 4 and 24 h. There was no evidence of extraarticular leakage. From the 67 Ga citrate imaging, the acute group shows an overall improvement of well being corresponding to a lesser uptake at the inflamated articulation, regarding to the chronic group. The 166 Ho-HA double dosis, compared to the single dosis, suggest a reduced uptake of 67 Ga citrate at the inflamated tissue, meaning an increased therapeutic effect. Conclusions: 166 Ho-HA is usefull as therapeutic agent for the syntomatic treatment of rheumatoideal arthritis as shown by imaging and clinical examination (author)

  15. [ManNAc, a new therapeutic agent to reduce Angptl4-induced proteinuria in MCD].

    Science.gov (United States)

    Clément, Lionel; Macé, Camille

    2016-01-01

    Current therapies used in minimal change disease (MCD) were originally designed to cure other diseases. They are only partially efficient, and present inconvenient side effects. Therefore, understanding the molecular mechanisms implicated in the pathogenesis of proteinuria in MCD could lead to new therapeutic strategies. A new experimental transgenic rat model of human MCD was generated. These NPHS2-Angptl4 transgenic rats over-express two different forms of the glycoprotein Angptl4 from the podocyte. The majority of the protein shows a lack of sialylation that is implicated in the pathogenesis of proteinuria. Supplementation of ManNAc, a precursor of sialic acid, significantly reduces albuminuria in those rats by increasing sialylation of the hyposialylated form of Angptl4. After treatment of the first episode of MCD with glucocorticoids in patients, ManNAc could be used as a maintenance drug, especially to reduce the frequency and intensity of relapse. ManNAc is a promising therapeutic agent for patients with MCD. © 2016 médecine/sciences – Inserm.

  16. Growth/differentiation factor-5: a candidate therapeutic agent for periodontal regeneration? A review of pre-clinical data.

    Science.gov (United States)

    Moore, Yolanda R; Dickinson, Douglas P; Wikesjö, Ulf M E

    2010-03-01

    Therapeutic concepts involving the application of matrix, growth and differentiation factors have been advocated in support of periodontal wound healing/regeneration. Growth/differentiation factor-5 (GDF-5), a member of the bone morphogenetic protein family, represents one such factor. The purpose of this review is to provide a background of the therapeutic effects of GDF-5 expressed in various musculoskeletal settings using small and large animal platforms. A comprehensive literature search was conducted to identify all reports in the English language evaluating GDF-5 using the PubMed and Google search engines, and a manual search of the reference lists from the electronically retrieved reports. Two reviewers independently screened the titles and abstracts from a total of 69 reports, 22 of which were identified as pre-clinical (in vivo) evaluations of GDF-5. The full-length article of the 22 pre-clinical reports was then reviewed. Various applications including cranial and craniofacial bone formation, spine fusion, long bone fracture healing, cartilage, and tendon/ligament repair using a variety of small and large animal platforms evaluating GDF-5 as a therapeutic agent were identified. A majority of studies, using biomechanical, radiographic, and histological analysis, demonstrated significant dose-dependent effects of GDF-5. These include increased/enhanced local bone formation, fracture healing/repair, and cartilage and tendon/ligament formation. GDF-5 frequently was shown to accelerate wound maturation. Several studies demonstrated GDF-5 to be a realistic alternative to autograft bone. Studies using pre-clinical models and human histology suggest GDF-5 may also increase/enhance periodontal wound healing/regeneration. GDF-5 appears a promising therapeutic agent for periodontal wound healing/regeneration as GDF-5 supports/accelerates bone and tendon/ligament formation in several musculoskeletal settings including periodontal tissues.

  17. Dihydrocoumarin, an HDAC Inhibitor, Increases DNA Damage Sensitivity by Inhibiting Rad52

    Directory of Open Access Journals (Sweden)

    Chin-Chuan Chen

    2017-12-01

    Full Text Available Effective DNA repair enables cancer cells to survive DNA damage induced by chemotherapeutic or radiotherapeutic treatments. Therefore, inhibiting DNA repair pathways is a promising therapeutic strategy for increasing the efficacy of such treatments. In this study, we found that dihydrocoumarin (DHC, a flavoring agent, causes deficiencies in double-stand break (DSB repair and prolonged DNA damage checkpoint recovery in yeast. Following DNA damage, Rad52 recombinase was revealed to be inhibited by DHC, which results in deficiencies in DSB repair and prolonged DNA damage checkpoint recovery. The deletion of RPD3, a class I histone deacetylase (HDAC, was found to mimic DHC-induced suppression of Rad52 expression, suggesting that the HDAC inhibitor activity of DHC is critical to DSB repair and DNA damage sensitivity. Overall, our findings delineate the regulatory mechanisms of DHC in DSB repair and suggest that it might potentially be used as an inhibitor of the DNA repair pathway in human cells.

  18. Preclinical therapeutic potential of a nitrosylating agent in the treatment of ovarian cancer.

    Directory of Open Access Journals (Sweden)

    Shailendra Giri

    Full Text Available This study examines the role of s-nitrosylation in the growth of ovarian cancer using cell culture based and in vivo approaches. Using the nitrosylating agent, S-nitrosoglutathione (GSNO, a physiological nitric oxide molecule, we show that GSNO treatment inhibited proliferation of chemoresponsive and chemoresistant ovarian cancer cell lines (A2780, C200, SKVO3, ID8, OVCAR3, OVCAR4, OVCAR5, OVCAR7, OVCAR8, OVCAR10, PE01 and PE04 in a dose dependent manner. GSNO treatment abrogated growth factor (HB-EGF induced signal transduction including phosphorylation of Akt, p42/44 and STAT3, which are known to play critical roles in ovarian cancer growth and progression. To examine the therapeutic potential of GSNO in vivo, nude mice bearing intra-peritoneal xenografts of human A2780 ovarian carcinoma cell line (2 × 10(6 were orally administered GSNO at the dose of 1 mg/kg body weight. Daily oral administration of GSNO significantly attenuated tumor mass (p<0.001 in the peritoneal cavity compared to vehicle (phosphate buffered saline treated group at 4 weeks. GSNO also potentiated cisplatin mediated tumor toxicity in an A2780 ovarian carcinoma nude mouse model. GSNO's nitrosylating ability was reflected in the induced nitrosylation of various known proteins including NFκB p65, Akt and EGFR. As a novel finding, we observed that GSNO also induced nitrosylation with inverse relationship at tyrosine 705 phosphorylation of STAT3, an established player in chemoresistance and cell proliferation in ovarian cancer and in cancer in general. Overall, our study underlines the significance of S-nitrosylation of key cancer promoting proteins in modulating ovarian cancer and proposes the therapeutic potential of nitrosylating agents (like GSNO for the treatment of ovarian cancer alone or in combination with chemotherapeutic drugs.

  19. Evaluation of Antioxidant and DNA Damage Protection Activity of the Hydroalcoholic Extract of Desmostachya bipinnata L. Stapf

    Directory of Open Access Journals (Sweden)

    Upendarrao Golla

    2014-01-01

    Full Text Available Desmostachya bipinnata Stapf (Poaceae/Gramineae is an official drug of ayurvedic pharmacopoeia. Various parts of this plant were used extensively in traditional and folklore medicine to cure various human ailments. The present study was aimed to evaluate the antioxidant and DNA damage protection activity of hydroalcoholic extract of Desmostachya bipinnata both in vitro and in vivo, to provide scientific basis for traditional usage of this plant. The extract showed significant antioxidant activity in a dose-dependent manner with an IC50 value of 264.18±3.47 μg/mL in H2O2 scavenging assay and prevented the oxidative damage to DNA in presence of DNA damaging agent (Fenton’s reagent at a concentration of 50 μg/mL. Also, the presence of extract protected yeast cells in a dose-dependent manner against DNA damaging agent (Hydroxyurea in spot assay. Moreover, the presence of extract exhibited significant antioxidant activity in vivo by protecting yeast cells against oxidative stressing agent (H2O2. Altogether, the results of current study revealed that Desmostachya bipinnata is a potential source of antioxidants and lends pharmacological credence to the ethnomedical use of this plant in traditional system of medicine, justifying its therapeutic application for free-radical-induced diseases.

  20. VIP as a potential therapeutic agent in gram negative sepsis.

    Science.gov (United States)

    Ibrahim, Hiba; Barrow, Paul; Foster, Neil

    2012-12-01

    Gram negative sepsis remains a high cause of mortality and places a great burden on public health finance in both the developed and developing world. Treatment of sepsis, using antibiotics, is often ineffective since pathology associated with the disease occurs due to dysregulation of the immune system (failure to return to steady state conditions) which continues after the bacteria, which induced the immune response, have been cleared. Immune modulation is therefore a rational approach to the treatment of sepsis but to date no drug has been developed which is highly effective, cheap and completely safe to use. One potential therapeutic agent is VIP, which is a natural peptide and is highly homologous in all vertebrates. In this review we will discuss the effect of VIP on components of the immune system, relevant to gram negative sepsis, and present data from animal models. Furthermore we will hypothesise on how these studies could be improved in future and speculate on the possible different ways in which VIP could be used in clinical medicine.

  1. Comparative study of radiopharmaceuticals as radiodiagnostic agent of cardiac damage in rats

    International Nuclear Information System (INIS)

    Gallego Heise, R.

    1983-01-01

    Six radiopharmaceuticals were screened in a small-animal model as potential infarct-localizing agents. The model used was subcutaneous inyection of isoproterenol (30 mg/kg of body weight) - induced myocardial lesions in rats, similar to an infarct and ischemia in human beings, corroborated by histological findings. The uptake of each radiopharmaceuticals is measured at various times after lesion initiation. The results are expressed as % I.D./g and through the contrast relations between the activity of whole heart of treated rats and the others tissues. The relation damaged heart/normal heart (DH/NH) of the phosphorated radiopharmaceuticals (sup(99m) Tc-PPi, sup(99m) Tc-MDP, sup(113m) In-EDTMP), and 197 Hg-MPG are significatively greater in rats with heart damaged than in the controls animals (undamaged); these were followed by sup(99m) Tc-GH and sup(99m) Tc-DMSA. Sup(99m) Tc-PPi, was the tracer that showed the mot favorable concentration in the lesion and the best target-non target ratios in most of the time intervals. At early time intervals 197 Hg-MPG showed the best DH/NH relation. (Author)

  2. Targeting neddylation induces DNA damage and checkpoint activation and sensitizes chronic lymphocytic leukemia B cells to alkylating agents.

    Science.gov (United States)

    Paiva, C; Godbersen, J C; Berger, A; Brown, J R; Danilov, A V

    2015-07-09

    Microenvironment-mediated upregulation of the B-cell receptor (BCR) and nuclear factor-κB (NF-κB) signaling in CLL cells resident in the lymph node and bone marrow promotes apoptosis evasion and clonal expansion. We recently reported that MLN4924 (pevonedistat), an investigational agent that inhibits the NEDD8-activating enzyme (NAE), abrogates stromal-mediated NF-κB pathway activity and CLL cell survival. However, the NAE pathway also assists degradation of multiple other substrates. MLN4924 has been shown to induce DNA damage and cell cycle arrest, but the importance of this mechanism in primary neoplastic B cells has not been studied. Here we mimicked the lymph node microenvironment using CD40 ligand (CD40L)-expressing stroma and interleukin-21 (IL-21) to find that inducing proliferation of the primary CLL cells conferred enhanced sensitivity to NAE inhibition. Treatment of the CD40-stimulated CLL cells with MLN4924 resulted in deregulation of Cdt1, a DNA replication licensing factor, and cell cycle inhibitors p21 and p27. This led to DNA damage, checkpoint activation and G2 arrest. Alkylating agents bendamustine and chlorambucil enhanced MLN4924-mediated DNA damage and apoptosis. These events were more prominent in cells stimulated with IL-21 compared with CD40L alone, indicating that, following NAE inhibition, the culture conditions were able to direct CLL cell fate from an NF-κB inhibition to a Cdt1 induction program. Our data provide insight into the biological consequences of targeting NAE in CLL and serves as further rationale for studying the clinical activity of MLN4924 in CLL, particularly in combination with alkylating agents.

  3. DNA excision repair in cell extracts from human cell lines exhibiting hypersensitivity to DNA-damaging agents

    International Nuclear Information System (INIS)

    Hansson, J.; Keyse, S.M.; Lindahl, T.; Wood, R.D.

    1991-01-01

    Whole cell extracts from human lymphoid cell lines can perform in vitro DNA repair synthesis in plasmids damaged by agents including UV or cis-diamminedichloroplatinum(II) (cis-DDP). Extracts from xeroderma pigmentosum (XP) cells are defective in repair synthesis. We have now studied in vitro DNA repair synthesis using extracts from lymphoblastoid cell lines representing four human hereditary syndromes with increased sensitivity to DNA-damaging agents. Extracts of cell lines from individuals with the sunlight-sensitive disorders dysplastic nevus syndrome or Cockayne's syndrome (complementation groups A and B) showed normal DNA repair synthesis in plasmids with UV photoproducts. This is consistent with in vivo measurements of the overall DNA repair capacity in such cell lines. A number of extracts were prepared from two cell lines representing the variant form of XP (XP-V). Half of the extracts prepared showed normal levels of in vitro DNA repair synthesis in plasmids containing UV lesions, but the remainder of the extracts from the same cell lines showed deficient repair synthesis, suggesting the possibility of an unusually labile excision repair protein in XP-V. Fanconi's anemia (FA) cells show cellular hypersensitivity to cross-linking agents including cis-DDP. Extracts from cell lines belonging to two different complementation groups of FA showed normal DNA repair synthesis in plasmids containing cis-DDP or UV adducts. Thus, there does not appear to be an overall excision repair defect in FA, but the data do not exclude a defect in the repair of interstrand DNA cross-links

  4. Mechanisms of chemoresistance to alkylating agents in malignant glioma.

    Science.gov (United States)

    Sarkaria, Jann N; Kitange, Gaspar J; James, C David; Plummer, Ruth; Calvert, Hilary; Weller, Michael; Wick, Wolfgang

    2008-05-15

    Intrinsic or acquired chemoresistance to alkylating agents is a major cause of treatment failure in patients with malignant brain tumors. Alkylating agents, the mainstay of treatment for brain tumors, damage the DNA and induce apoptosis, but the cytotoxic activity of these agents is dependent on DNA repair pathways. For example, O6-methylguanine DNA adducts can cause double-strand breaks, but this is dependent on a functional mismatch repair pathway. Thus, tumor cell lines deficient in mismatch repair are resistant to alkylating agents. Perhaps the most important mechanism of resistance to alkylating agents is the DNA repair enzyme O6-methylguanine methyltransferase, which can eliminate the cytotoxic O6-methylguanine DNA adduct before it causes harm. Another mechanism of resistance to alkylating agents is the base excision repair (BER) pathway. Consequently, efforts are ongoing to develop effective inhibitors of BER. Poly(ADP-ribose)polymerase plays a pivotal role in BER and is an important therapeutic target. Developing effective strategies to overcome chemoresistance requires the identification of reliable preclinical models that recapitulate human disease and which can be used to facilitate drug development. This article describes the diverse mechanisms of chemoresistance operating in malignant glioma and efforts to develop reliable preclinical models and novel pharmacologic approaches to overcome resistance to alkylating agents.

  5. Carboxylated nanodiamonds inhibit γ-irradiation damage of human red blood cells.

    Science.gov (United States)

    Santacruz-Gomez, K; Silva-Campa, E; Melendrez-Amavizca, R; Teran Arce, F; Mata-Haro, V; Landon, P B; Zhang, C; Pedroza-Montero, M; Lal, R

    2016-04-07

    Nanodiamonds when carboxylated (cNDs) act as reducing agents and hence could limit oxidative damage in biological systems. Gamma (γ)-irradiation of whole blood or its components is required in immunocompetent patients to prevent transfusion-associated graft versus host disease (TA-GVHD). However, γ-irradiation of blood also deoxygenates red blood cells (RBCs) and induces oxidative damage, including abnormalities in cellular membranes and hemolysis. Using atomic force microscopy (AFM) and Raman spectroscopy, we examined the effect of cNDs on γ-irradiation mediated deoxygenation and morphological damage of RBCs. γ-Radiation induced several morphological phenotypes, including stomatocytes, codocytes and echinocytes. While stomatocytes and codocytes are reversibly damaged RBCs, echinocytes are irreversibly damaged. AFM images show significantly fewer echinocytes among cND-treated γ-irradiated RBCs. The Raman spectra of γ-irradiated RBCs had more oxygenated hemoglobin patterns when cND-treated, resembling those of normal, non-irradiated RBCs, compared to the non-cND-treated RBCs. cND inhibited hemoglobin deoxygenation and morphological damage, possibly by neutralizing the free radicals generated during γ-irradiation. Thus cNDs have the therapeutic potential to preserve the quality of stored blood following γ-irradiation.

  6. The influence of polymeric excipients on the process of pharmaceutical availability of therapeutic agents from a model drug form. Part I. In formulations with controlled disintegration and release time.

    Science.gov (United States)

    Nachajski, Michal Jakub; Zgoda, Marian Mikołaj

    2010-01-01

    Pre-formulation research was conducted on the application of Ex. Echinaceae aq. siccum in the production of a quickly disintegrating suspension tablet, a lozenge with kariostatic sugar alcohols (mannitol, sorbitol), and, above all, a solid drug form with controlled release of therapeutic agents included in the extract. Morphological parameters of tablets obtained in the course of experiment were estimated and the profiles of the release (diffusion) ofhydrophilic therapeutic agents into model receptor fluids with varying values of osmolarity (0.1 mol HCl approximately 200 mOsm/l, hypotonic hydrating fluid approximately 143 mOsm/l, and compensatory paediatric fluid approximately 272 mOsm/l) were examined. The study focused on the technological problem of determining the effect of hydrogel Carbopol structure on the ordering of diffusion ofhydrophilic therapeutic agents from a model drug form (a tablet) into model fluids with variable osmolarity.

  7. Choline and Geranate Deep Eutectic Solvent as a Broad-Spectrum Antiseptic Agent for Preventive and Therapeutic Applications.

    Science.gov (United States)

    Zakrewsky, Michael; Banerjee, Amrita; Apte, Sanjana; Kern, Theresa L; Jones, Mattie R; Sesto, Rico E Del; Koppisch, Andrew T; Fox, David T; Mitragotri, Samir

    2016-06-01

    Antiseptic agents are the primary arsenal to disinfect skin and prevent pathogens spreading within the host as well as into the surroundings; however the Food and Drug Administration published a report in 2015 requiring additional validation of nearly all current antiseptic agents before their continued use can be allowed. This vulnerable position calls for urgent identification of novel antiseptic agents. Recently, the ability of a deep eutectic, Choline And Geranate (CAGE), to treat biofilms of Pseudomonas aeruginosa and Salmonella enterica was demonstrated. Here it is reported that CAGE exhibits broad-spectrum antimicrobial activity against a number of drug-resistant bacteria, fungi, and viruses including clinical isolates of Mycobacterium tuberculosis, Staphylococcus aureus, and Candida albicans as well as laboratory strains of Herpes Simplex Virus. Studies in human keratinocytes and mice show that CAGE affords negligible local or systemic toxicity, and an ≈180-14 000-fold improved efficacy/toxicity ratio over currently used antiseptic agents. Further, CAGE penetrates deep into the dermis and treats pathogens located in deep skin layers as confirmed by the ability of CAGE in vivo to treat Propionibacterium acnes infection. In combination, the results clearly demonstrate CAGE holds promise as a transformative platform antiseptic agent for preventive as well as therapeutic applications. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Mutations at the mei-41, mus(1)101, mus(1)103, mus(2)205 and mus(3)310 loci of Drosophila exhibit differential UDS responses with different DNA-damaging agents

    International Nuclear Information System (INIS)

    Dusenbery, R.L.

    1987-01-01

    5 mutagen-sensitive mutants of Drosophila melanogaster, reported to perform normal or only slightly reduced excision repair of UV damage, were examined by an unscheduled DNA synthesis (UDS) assay. 2 mutants, classified as completely or partially proficient for both excision and postreplication repair of UV damage, mus(1)103 and mus(2)205, were found to give positive UDS responses only for UV damage. These mutants exhibit no measurable UDS activity following DNA damage by several different alkylating agents and X-rays. 3 mutants, classified as having no defect in excision repair, but measurable defects in postreplication repair of UV damage, exhibit 3 different response patterns. The mutant mei-41 exhibits a highly positive UDS response following damage by all agents, consistent with its prior classification as excision-repair-proficient, but postreplication-repair-deficient for UV damage. The mutant mus(1)101, however, exhibits a strong positive UDS response following only UV damage and appears to be blocked in the excision repair of damage produced by both alkylating agents and X-irradiation. Finally, mus(3)310 exhibits no UDS response to alkylation, X-ray or UV damage. This is not consistent with its previous classification. Results obtained w0272the qualitative in vitro UDS assay are entirely consistent with the results from two separate in vivo measures of excision repair deficiency followign DNA damage, larval hypersensitivity to killing and hypermutability in the sex-linked recessive lethal test. (Auth.)

  9. Adaptive response to DNA-damaging agents in natural Saccharomyces cerevisiae populations from "Evolution Canyon", Mt. Carmel, Israel.

    Directory of Open Access Journals (Sweden)

    Gabriel A Lidzbarsky

    2009-06-01

    Full Text Available Natural populations of most organisms, especially unicellular microorganisms, are constantly exposed to harsh environmental factors which affect their growth. UV radiation is one of the most important physical parameters which influences yeast growth in nature. Here we used 46 natural strains of Saccharomyces cerevisiae isolated from several natural populations at the "Evolution Canyon" microsite (Nahal Oren, Mt. Carmel, Israel. The opposing slopes of this canyon share the same geology, soil, and macroclimate, but they differ in microclimatic conditions. The interslope differences in solar radiation (200%-800% more on the "African" slope caused the development of two distinct biomes. The south-facing slope is sunnier and has xeric, savannoid "African" environment while the north-facing slope is represented by temperate, "European" forested environment. Here we studied the phenotypic response of the S. cerevisiae strains to UVA and UVC radiations and to methyl methanesulfonate (MMS in order to evaluate the interslope effect on the strains' ability to withstand DNA-damaging agents.We exposed our strains to the different DNA-damaging agents and measured survival by counting colony forming units. The strains from the "African" slope were more resilient to both UVA and MMS than the strains from the "European" slope. In contrast, we found that there was almost no difference between strains (with similar ploidy from the opposite slopes, in their sensitivity to UVC radiation. These results suggest that the "African" strains are more adapted to higher solar radiation than the "European" strains. We also found that the tetraploids strains were more tolerant to all DNA-damaging agents than their neighboring diploid strains, which suggest that high ploidy level might be a mechanism of adaptation to high solar radiation.Our results and the results of parallel studies with several other organisms, suggest that natural selection appears to select, at a

  10. Chelating agents in pharmacology, toxicology and therapeutics

    International Nuclear Information System (INIS)

    1988-01-01

    The proceedings contain 71 abstracts of papers. Fourteen abstracts were inputted in INIS. The topics covered include: the effects of chelating agents on the retention of 63 Ni, 109 Cd, 203 Hg, 144 Ce, 95 Nb and the excretion of 210 Po, 63 Ni, 48 V, 239 Pu, 241 Am, 54 Mn; the applications of tracer techniques for studies of the efficacy of chelation therapy in patients with heart and brain disorders; and the treatment of metal poisoning with chelating agents. (J.P.)

  11. Quercetin as an Emerging Anti-Melanoma Agent: A four-focus area therapeutic development strategy

    Directory of Open Access Journals (Sweden)

    Zoey Harris

    2016-10-01

    Full Text Available Replacing current refractory treatments for melanoma with new prevention and therapeutic approaches is crucial in order to successfully treat this aggressive cancer form. Melanoma develops from neural crest cells, which express tyrosinase -- a key enzyme in the pigmentation pathway. The tyrosinase enzyme is highly active in melanoma cells and metabolizes polyphenolic compounds; tyrosinase expression thus makes a feasible a target for polyphenol-based therapies. For example, quercetin (3,3′,4′,5,7-pentahydroxyflavone is a highly ubiquitous and well-classified dietary polyphenol found in various fruits, vegetables and other plant products including onions, broccoli, kale, oranges, blueberries, apples, and tea. Quercetin has demonstrated anti-proliferative and pro-apoptotic activity in various cancer cell types. Quercetin is readily metabolized by tyrosinase into various compounds that promote anti-cancer activity; additionally, given that tyrosinase expression increases during tumorigenesis, and its activity is associated with pigmentation changes in both early- and late-stage melanocytic lesions, it suggests that quercetin can be used to target melanoma. In this review we explore the potential of Quercetin as an anti-melanoma agent utilizing and extrapolating on evidence from previous in vitro studies in various human malignant cell lines and propose a four-focus area strategy to develop quercetin as a targeted anti-melanoma compound for use as either a preventative or therapeutic agent. The four areas of focus include utilizing quercetin to i modulate cellular bioreduction potential and associated signaling cascades, ii affect transcription of relevant genes, iii regulate epigenetic processes, and iv develop effective combination therapies and delivery modalities/protocols. In general, quercetin could be used to exploit tyrosinase activity to prevent, and/or treat, melanoma with minimal additional side effects.

  12. Protein based therapeutic delivery agents: Contemporary developments and challenges.

    Science.gov (United States)

    Yin, Liming; Yuvienco, Carlo; Montclare, Jin Kim

    2017-07-01

    As unique biopolymers, proteins can be employed for therapeutic delivery. They bear important features such as bioavailability, biocompatibility, and biodegradability with low toxicity serving as a platform for delivery of various small molecule therapeutics, gene therapies, protein biologics and cells. Depending on size and characteristic of the therapeutic, a variety of natural and engineered proteins or peptides have been developed. This, coupled to recent advances in synthetic and chemical biology, has led to the creation of tailor-made protein materials for delivery. This review highlights strategies employing proteins to facilitate the delivery of therapeutic matter, addressing the challenges for small molecule, gene, protein and cell transport. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Development of haemostatic decontaminants for treatment of wounds contaminated with chemical warfare agents. 3: Evaluation of in vitro topical decontamination efficacy using damaged skin.

    Science.gov (United States)

    Lydon, Helen L; Hall, Charlotte A; Dalton, Christopher H; Chipman, J Kevin; Graham, John S; Chilcott, Robert P

    2017-08-01

    Previous studies have demonstrated that haemostatic products with an absorptive mechanism of action retain their clotting efficiency in the presence of toxic materials and are effective in decontaminating chemical warfare (CW) agents when applied to normal, intact skin. The purpose of this in vitro study was to assess three candidate haemostatic products for effectiveness in the decontamination of superficially damaged porcine skin exposed to the radiolabelled CW agents, soman (GD), VX and sulphur mustard (HD). Controlled physical damage (removal of the upper 100 μm skin layer) resulted in a significant enhancement of the dermal absorption of all three CW agents. Of the haemostatic products assessed, WoundStat™ was consistently the most effective, being equivalent in performance to a standard military decontaminant (fuller's earth). These data suggest that judicious application of haemostatic products to wounds contaminated with CW agents may be a viable option for the clinical management of casualties presenting with contaminated, haemorrhaging injuries. Further studies using a relevant animal model are required to confirm the potential clinical efficacy of WoundStat™ for treating wounds contaminated with CW agents. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

  14. Vitamin A-aldehyde adducts: AMD risk and targeted therapeutics.

    Science.gov (United States)

    Sparrow, Janet R

    2016-04-26

    Although currently available treatment options for age-related macular degeneration (AMD) are limited, particularly for atrophic AMD, the identification of predisposing genetic variations has informed clinical studies addressing therapeutic options such as complement inhibitors and anti-inflammatory agents. To lower risk of early AMD, recommended lifestyle interventions such as the avoidance of smoking and the intake of low glycemic antioxidant-rich diets have largely followed from the identification of nongenetic modifiable factors. On the other hand, the challenge of understanding the complex relationship between aging and cumulative damage leading to AMD has fueled investigations of the visual cycle adducts that accumulate in retinal pigment epithelial (RPE) cells and are a hallmark of aging retina. These studies have revealed properties of these compounds that provide insights into processes that may compromise RPE and could contribute to disease mechanisms in AMD. This work has also led to the design of targeted therapeutics that are currently under investigation.

  15. Nutraceuticals as therapeutic agents for atherosclerosis.

    Science.gov (United States)

    Moss, Joe W E; Williams, Jessica O; Ramji, Dipak P

    2018-05-01

    Atherosclerosis, a chronic inflammatory disorder of medium and large arteries and an underlying cause of cardiovascular disease (CVD), is responsible for a third of all global deaths. Current treatments for CVD, such as optimized statin therapy, are associated with considerable residual risk and several side effects in some patients. The outcome of research on the identification of alternative pharmaceutical agents for the treatment of CVD has been relatively disappointing with many promising leads failing at the clinical level. Nutraceuticals, products from food sources with health benefits beyond their nutritional value, represent promising agents in the prevention of CVD or as an add-on therapy with current treatments. This review will highlight the potential of several nutraceuticals, including polyunsaturated fatty acids, flavonoids and other polyphenols, as anti-CVD therapies based on clinical and pre-clinical mechanism-based studies. Copyright © 2018 The Author(s). Published by Elsevier B.V. All rights reserved.

  16. Mesenchymal Stem/Stromal Cell-Derived Extracellular Vesicles and Their Potential as Novel Immunomodulatory Therapeutic Agents

    Directory of Open Access Journals (Sweden)

    Verena Börger

    2017-07-01

    Full Text Available Extracellular vesicles (EVs, such as exosomes and microvesicles, have been identified as mediators of a newly-discovered intercellular communication system. They are essential signaling mediators in various physiological and pathophysiological processes. Depending on their origin, they fulfill different functions. EVs of mesenchymal stem/stromal cells (MSCs have been found to promote comparable therapeutic activities as MSCs themselves. In a variety of in vivo models, it has been observed that they suppress pro-inflammatory processes and reduce oxidative stress and fibrosis. By switching pro-inflammatory into tolerogenic immune responses, MSC-EVs very likely promote tissue regeneration by creating a pro-regenerative environment allowing endogenous stem and progenitor cells to successfully repair affected tissues. Accordingly, MSC-EVs provide a novel, very promising therapeutic agent, which has already been successfully applied to humans. However, the MSC-EV production process has not been standardized, yet. Indeed, a collection of different protocols has been used for the MSC-EV production, characterization and application. By focusing on kidney, heart, liver and brain injuries, we have reviewed the major outcomes of published MSC-EV in vivo studies.

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

    International Nuclear Information System (INIS)

    Fareed, J.; Moncada, R.; Scanlon, P.; Hoppensteadt, D.; Huan, X.; Walenga, J.M.

    1987-01-01

    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

  18. Interactions of radiation with novel chemotherapeutic agents: Taxanes and nucleoside analogs

    International Nuclear Information System (INIS)

    Milas, Luka

    1997-01-01

    The combination of chemotherapeutic agents and radiotherapy is an appealing approach to improving the results of cancer treatment. By their independent action or interactive action chemotherapeutic drugs reduce cell burden in tumors undergoing radiotherapy, thereby increasing the chances of tumor control. In addition, the drugs may spatially cooperate with radiotherapy through their systemic action on metastatic disease. Recently, a number of new chemotherapeutic agents have been introduced for cancer treatment, which in addition have high potential to increase therapeutic ratio of radiotherapy. These agents include taxanes (paclitaxel and docetaxel) and the nucleoside analogs fludarabine and gemcitabine. Paclitaxel is a natural product isolated from the bark of Taxus brevifolia and taxotere is a semisynthetic analogue of paclitaxel prepared from needle extracts of Taxus baccata. By binding to cellular tubulin structures, taxanes interfere with tubulin polymerization and promote microtubule assembly, resulting in accumulation of cells in the radiosensitive G2 and M phases of the cell cycle. In vivo studies have demonstrated two major mechanisms of tumor radioenhancement by taxanes: mitotic arrest and tumor reoxygenation. Fludarabine and gemcitabine inhibit DNA synthesis and the repair of radiation-induced chromosome breaks. The mechanism of their radioenhancing activity include inhibition of repair of radiation induced damage, apoptosis induction and cell cycle synchronization. Because both classes of these agents affect radioresponse of normal dose-limiting tissues much less than that of tumors, they can greatly increase therapeutic ratio of radiotherapy. The objective of this course is to overview the rationale for using these drugs as radioenhancing agents, the experimental findings in preclinical studies, the mechanisms of their interaction, and the clinical application of these agents

  19. Potential therapeutic agents for circulatory diseases from Bauhinia glauca Benth.subsp. pernervosa. (Da Ye Guan Men).

    Science.gov (United States)

    Tang, Yingzhan; Ling, Junhong; Zhang, Peng; Zhang, Xiangrong; Zhang, Na; Wang, Wenli; Li, Jiayuan; Li, Ning

    2015-08-15

    Because of platelets as critical factor in the formation of pathogenic thrombi, anti-platelet activities have been selected as therapeutic target for various circulatory diseases. In order to find potential therapeutic agents, bioassay-directed separation of Bauhinia glauca Benth.subsp. pernervosa. (called Da Ye Guan Men as a traditional Chinese medicine) was performed to get 29 main components (compounds 1-29) from the bioactive part of this herbal. It was the first time to focus on the composition with anti-platelet aggregation activities for this traditional Chinese medicine. The constituents, characterized from the effective extract, were established on the basis of extensive spectral data analysis. Then their anti-platelet aggregation effects were evaluated systematically. On the basis of the chemical profile and biological assay, it was suggested that the flavonoid composition (5 and 18) should be responsible for the anti-platelet aggregation of the herbal because of their significant activities. The primary structure and activity relationship was also discussed briefly. Copyright © 2015. Published by Elsevier Ltd.

  20. Complex DNA repair pathways as possible therapeutic targets to overcome temozolomide resistance in glioblastoma

    International Nuclear Information System (INIS)

    Yoshimoto, Koji; Mizoguchi, Masahiro; Hata, Nobuhiro; Murata, Hideki; Hatae, Ryusuke; Amano, Toshiyuki; Nakamizo, Akira; Sasaki, Tomio

    2012-01-01

    Many conventional chemotherapeutic drugs exert their cytotoxic function by inducing DNA damage in the tumor cell. Therefore, a cell-inherent DNA repair pathway, which reverses the DNA-damaging effect of the cytotoxic drugs, can mediate therapeutic resistance to chemotherapy. The monofunctional DNA-alkylating agent temozolomide (TMZ) is a commonly used chemotherapeutic drug and the gold standard treatment for glioblastoma (GBM). Although the activity of DNA repair protein O6-methylguanine-DNA methyltransferase (MGMT) has been described as the main modulator to determine the sensitivity of GBM to TMZ, a subset of GBM does not respond despite MGMT inactivation, suggesting that another DNA repair mechanism may also modulate the tolerance to TMZ. Considerable interest has focused on MGMT, mismatch repair (MMR), and the base excision repair (BER) pathway in the mechanism of mediating TMZ resistance, but emerging roles for the DNA strand-break repair pathway have been demonstrated. In the first part of this review article, we briefly review the significant role of MGMT, MMR, and the BER pathway in the tolerance to TMZ; in the last part, we review the recent publications that demonstrate possible roles of DNA strand-break repair pathways, such as single-strand break repair and double-strand break repair, as well as the Fanconi anemia pathway in the repair process after alkylating agent-based therapy. It is possible that all of these repair pathways have a potential to modulate the sensitivity to TMZ and aid in overcoming the therapeutic resistance in the clinic.

  1. Complex DNA repair pathways as possible therapeutic targets to overcome temozolomide resistance in glioblastoma

    Energy Technology Data Exchange (ETDEWEB)

    Yoshimoto, Koji; Mizoguchi, Masahiro; Hata, Nobuhiro; Murata, Hideki; Hatae, Ryusuke; Amano, Toshiyuki; Nakamizo, Akira; Sasaki, Tomio, E-mail: kyoshimo@ns.med.kyushu-u.ac.jp [Department of Neurosurgery, Graduate School of Medical Sciences, Kyushu University, Fukuoka (Japan)

    2012-12-05

    Many conventional chemotherapeutic drugs exert their cytotoxic function by inducing DNA damage in the tumor cell. Therefore, a cell-inherent DNA repair pathway, which reverses the DNA-damaging effect of the cytotoxic drugs, can mediate therapeutic resistance to chemotherapy. The monofunctional DNA-alkylating agent temozolomide (TMZ) is a commonly used chemotherapeutic drug and the gold standard treatment for glioblastoma (GBM). Although the activity of DNA repair protein O6-methylguanine-DNA methyltransferase (MGMT) has been described as the main modulator to determine the sensitivity of GBM to TMZ, a subset of GBM does not respond despite MGMT inactivation, suggesting that another DNA repair mechanism may also modulate the tolerance to TMZ. Considerable interest has focused on MGMT, mismatch repair (MMR), and the base excision repair (BER) pathway in the mechanism of mediating TMZ resistance, but emerging roles for the DNA strand-break repair pathway have been demonstrated. In the first part of this review article, we briefly review the significant role of MGMT, MMR, and the BER pathway in the tolerance to TMZ; in the last part, we review the recent publications that demonstrate possible roles of DNA strand-break repair pathways, such as single-strand break repair and double-strand break repair, as well as the Fanconi anemia pathway in the repair process after alkylating agent-based therapy. It is possible that all of these repair pathways have a potential to modulate the sensitivity to TMZ and aid in overcoming the therapeutic resistance in the clinic.

  2. Neuroinflammation in the pathogenesis of Alzheimer's disease. A rational framework for the search of novel therapeutic approaches.

    Science.gov (United States)

    Morales, Inelia; Guzmán-Martínez, Leonardo; Cerda-Troncoso, Cristóbal; Farías, Gonzalo A; Maccioni, Ricardo B

    2014-01-01

    Alzheimer disease (AD) is the most common cause of dementia in people over 60 years old. The molecular and cellular alterations that trigger this disease are still diffuse, one of the reasons for the delay in finding an effective treatment. In the search for new targets to search for novel therapeutic avenues, clinical studies in patients who used anti-inflammatory drugs indicating a lower incidence of AD have been of value to support the neuroinflammatory hypothesis of the neurodegenerative processes and the role of innate immunity in this disease. Neuroinflammation appears to occur as a consequence of a series of damage signals, including trauma, infection, oxidative agents, redox iron, oligomers of τ and β-amyloid, etc. In this context, our theory of Neuroimmunomodulation focus on the link between neuronal damage and brain inflammatory process, mediated by the progressive activation of astrocytes and microglial cells with the consequent overproduction of proinflammatory agents. Here, we discuss about the role of microglial and astrocytic cells, the principal agents in neuroinflammation process, in the development of neurodegenerative diseases such as AD. In this context, we also evaluated the potential relevance of natural anti-inflammatory components, which include curcumin and the novel Andean Compound, as agents for AD prevention and as a coadjuvant for AD treatments.

  3. Therapeutic Potential of Mesenchymal Stem Cell-Derived Exosomes in the Treatment of Eye Diseases.

    Science.gov (United States)

    Harrell, C Randall; Simovic Markovic, Bojana; Fellabaum, Crissy; Arsenijevic, Aleksandar; Djonov, Valentin; Arsenijevic, Nebojsa; Volarevic, Vladislav

    2018-05-18

    Mesenchymal stem cells (MSCs) were, due to their immunomodulatory and pro-angiogenic characteristics, extensively explored as new therapeutic agents in cell-based therapy of uveitis, glaucoma, retinal and ocular surface diseases.Since it was recently revealed that exosomes play an important role in biological functions of MSCs, herewith we summarized current knowledge about the morphology, structure, phenotype and functional characteristics of MSC-derived exosomes emphasizing their therapeutic potential in the treatment of eye diseases.MSC-derived exosomes were as efficient as transplanted MSCs in limiting the extent of eye injury and inflammation. Immediately after intravitreal injection, MSC-derived exosomes, due to nano-dimension, diffused rapidly throughout the retina and significantly attenuated retinal damage and inflammation. MSC-derived exosomes successfully delivered trophic and immunomodulatory factors to the inner retina and efficiently promoted survival and neuritogenesis of injured retinal ganglion cells. MSC-derived exosomes efficiently suppressed migration of inflammatory cells, attenuated detrimental Th1 and Th17 cell-driven immune response and ameliorated experimental autoimmune uveitis. MSC-derived exosomes were able to fuse with the lysosomes within corneal cells, enabling delivering of MSC-derived active β-glucuronidase and consequent catabolism of accumulated glycosaminoglycans, indicating their therapeutic potential in the treatment of Mucopolysaccharidosis VII (Sly Syndrome). Importantly, beneficent effects were noticed only in animals that received MSC-derived exosomes and were not seen after therapy with fibroblasts-derived exosomes confirming specific therapeutic potential of MSCs and their products in the treatment of eye diseases.In conclusion, MSC-derived exosomes represent potentially new therapeutic agents in the therapy of degenerative and inflammatory ocular diseases.

  4. DNA damage and autophagy

    International Nuclear Information System (INIS)

    Rodriguez-Rocha, Humberto; Garcia-Garcia, Aracely; Panayiotidis, Mihalis I.; Franco, Rodrigo

    2011-01-01

    Both exogenous and endogenous agents are a threat to DNA integrity. Exogenous environmental agents such as ultraviolet (UV) and ionizing radiation, genotoxic chemicals and endogenous byproducts of metabolism including reactive oxygen species can cause alterations in DNA structure (DNA damage). Unrepaired DNA damage has been linked to a variety of human disorders including cancer and neurodegenerative disease. Thus, efficient mechanisms to detect DNA lesions, signal their presence and promote their repair have been evolved in cells. If DNA is effectively repaired, DNA damage response is inactivated and normal cell functioning resumes. In contrast, when DNA lesions cannot be removed, chronic DNA damage triggers specific cell responses such as cell death and senescence. Recently, DNA damage has been shown to induce autophagy, a cellular catabolic process that maintains a balance between synthesis, degradation, and recycling of cellular components. But the exact mechanisms by which DNA damage triggers autophagy are unclear. More importantly, the role of autophagy in the DNA damage response and cellular fate is unknown. In this review we analyze evidence that supports a role for autophagy as an integral part of the DNA damage response.

  5. Therapeutic journery of nitrogen mustard as alkylating anticancer agents: Historic to future perspectives.

    Science.gov (United States)

    Singh, Rajesh K; Kumar, Sahil; Prasad, D N; Bhardwaj, T R

    2018-05-10

    Cancer is considered as one of the most serious health problems today. The discovery of nitrogen mustard as an alkylating agent in 1942, opened a new era in the cancer chemotherapy. This valuable class of alkylating agent exerts its biological activity by binding to DNA, cross linking two strands, preventing DNA replication and ultimate cell death. At the molecular level, nitrogen lone pairs of nitrogen mustard generate a strained intermediate "aziridinium ion" which is very reactive towards DNA of tumor cell as well as normal cell resulting in various adverse side effects alogwith therapeutic implications. Over the last 75 years, due to its high reactivity and peripheral cytotoxicity, numerous modifications have been made in the area of nitrogen mustard to improve its efficacy as well as enhancing drug delivery specifically to tumor cells. This review mainly discusses the medicinal chemistry aspects in the development of various classes of nitrogen mustards (mechlorethamine, chlorambucil, melphalan, cyclophosphamide and steroidal based nitrogen mustards). The literature collection includes the historical and the latest developments in these areas. This comprehensive review also attempted to showcase the recent progress in the targeted delivery of nitrogen mustards that includes DNA directed nitrogen mustards, antibody directed enzyme prodrug therapy (ADEPT), gene directed enzyme prodrug therapy (GDEPT), nitrogen mustard activated by glutathione transferase, peptide based nitrogen mustards and CNS targeted nitrogen mustards. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

  6. MUCOLYTIC AGENTS IN PEDIATRICS: RATIONAL SELECTION, THERAPEUTIC EFFECTS AND SPECIFIC ASPECTS OF TREATMENT

    Directory of Open Access Journals (Sweden)

    O. I. Simonova

    2013-01-01

    Full Text Available The article deals with the cough treatment options with mucolytic agents administration at the first several days of acute respiratory tract infections in children. Efficacy of treatment with secretolytic and secretomotoric drugs significantly depends on certain factors. The article contains the criteria of therapeutic efficacy of expectorants. A special attention is given to N-acetylcysteine — a direct acting mucolytic agent, which effect is caused by presence of free sulfhydryl groups, disrupting disulfide bonds between molecules of acid mucopolysaccharides and glycoproteins therefore changing the structure of sputum. Acetylcysteine is active against every type of sputum (mucous, muco-purulent, purulent, that is especially important in treatment of bacterial infections, when it is necessary to quickly decrease sputum thickness, eliminate it from the respiratory tract and prevent dissemination of the infection. High efficacy of acetylcysteine is caused by its unique triple action: mucolytic, antioxidant and antitoxic. Mechanism of action of acetylcysteine is discussed in detail. Timely administered treatment will improve sputum discharge and therefore eliminate one of the main factors of bronchial obstruction and decrease the risk of microbial colonization of the respiratory tract. The article also includes indications, contraindications and dosage regimens of acetylcysteine in children. The most common mistakes and specific aspects of mucolytic drugs in pediatrics are listed in the conclusion. 

  7. [Weighing use and safety of therapeutic agents and feed additives (author's transl)].

    Science.gov (United States)

    van der Wal, P

    1982-02-01

    (1) The pros and cons of using feed additives and therapeutic agents may be successfully weighed in the light of carefully considered consumer requirements. (2) The socio-economic interests of the producer and the welfare of the animal will also determine the response of the production apparatus to consumer requirements. (3) Consumption of the current amounts of products of animal origin and maintenance of price and quality will only be feasible in the event of rational large-scale production in which constituents used in nutrition, prophylaxis and therapeutics are highly important factors. (4) Using these ingredients should be preceded by accurate evaluation of their use and safety. Testing facilities, conduct of studies and reporting should be such as to make the results nationally and internationally acceptable to all those concerned. (5) In deciding whether feed constituents are acceptable in view of the established use and safety, compliance will have to be sought with those standards which are accepted in other fields of society. Measures which result in raising the price of food without actually helping to reduce the risks to the safety of man, animals and environment, are likely to be rejected by any well-informed consumer who is aware of the facts. (6) For accurate weighing of use and safety at a national level, possibilities are hardly adequate in Europe. Decisions reached within the framework of the European Community, also tuned to U.S.A.- conditions are rightly encouraged. A centrally managed professionally staffed and equipped test system in the European Community would appear to be indispensable.

  8. Therapeutic potential of thiazolidinedione-8 as an antibiofilm agent against Candida albicans.

    Directory of Open Access Journals (Sweden)

    Mark Feldman

    Full Text Available Candida albicans is known as a commensal microorganism but it is also the most common fungal pathogen in humans, causing both mucosal and systemic infections. Biofilm-associated C. albicans infections present clinically important features due to their high levels of resistance to traditional antifungal agents. Quorum sensing is closely associated with biofilm formation and increasing fungal pathogenicity. We investigated the ability of the novel bacterial quorum sensing quencher thiazolidinedione-8 (S-8 to inhibit the formation of, and eradication of mature C. albicans biofilms. In addition, the capability of S-8 to alter fungal adhesion to mammalian cells was checked. S-8 exhibited specific antibiofilm and antiadhesion activities against C. albicans, at four- to eightfold lower concentrations than the minimum inhibitory concentration (MIC. Using fluorescence microscopy, we observed that S-8 dose-dependently reduces C. albicans-GFP binding to RAW macrophages. S-8 at sub-MICs also interfered with fungal morphogenesis by inhibiting the yeast-to-hyphal form transition. In addition, the tested agent strongly affected fungal cell wall characteristics by modulating its hydrophobicity. We evaluated the molecular mode of S-8 antibiofilm and antiadhesion activities using real-time RT-PCR. The expression levels of genes associated with biofilm formation, adhesion and filamentation, HWP1, ALS3 and EAP1, respectively, were dose-dependently downregulated by S-8. Transcript levels of UME6, responsible for long-term hyphal maintenance, were also significantly decreased by the tested agent. Both signaling pathways of hyphal formation-cAMP-PKA and MAPK-were interrupted by S-8. Their upstream general regulator RAS1 was markedly suppressed by S-8. In addition, the expression levels of MAPK cascade components CST20, HST7 and CPH1 were downregulated by S-8. Finally, transcriptional repressors of filament formation, TUP1 and NRG1, were dramatically upregulated by our

  9. FANCG knockout CHO cells display sensitivity to diverse DNA damaging agents and possible genomic instability

    International Nuclear Information System (INIS)

    Hinz, J.M.; Tebbs, R.S.; Yamada, N.A.; Salazar, E.P.; Kopf, V.L.; Thompson, L.H.

    2003-01-01

    Full text: The function of the proteins encoded by the genes responsible for the disease Fanconi anemia (FA) have not been elucidated. Several of these proteins (FancA, C, E, F, and G) form a complex in the nucleus, and cells deficient in any one of these proteins are sensitive to crosslinking agents, suggesting a possible role for these proteins in some aspect of DNA repair, chromosomal maintenance, or replication. We constructed a FancG knockout mutant (FGKO40) in CHO AA8 cells, as well as FancG-corrected FGKO40 cells (KO40BP6, which is a pool of six BAC-clone transformants). FGKO40 cells are sensitive to a wide variety of DNA damaging agents. Sensitivity to the cross-linking agents MMC (3x) and chloroethyl-nitrosourea (3x) does not exceed that of methyl methanesulfonate (MMS) (4x), methyl-nitrosourea (4x), or ethyl-nitrosourea (3x), or the purine analog 6-thioguanine (5x). Other agents show mild sensitivity in FGKO40 cells: ionizing radiation (1.2x), UV-C (1.5x), hydroxyurea (1.2x), camptothecin (1.2x), and excess thymidine (normal). The length of S phase was carefully measured by monitoring the progression of highly synchronous G1 cells obtained by centrifugal elutriation. FGKO40 cells traversed S phase normally but had a slightly longer G2 phase than parental cells. Treatment of synchronized G1 cells with MMS did not increase S phase in parental or mutant cells, but again G2 was slightly longer for FGKO40. Mutation rates were measured at the hrpt and aprt loci, where gene inactivation confers resistance to 6-thioguanine or 8-azaadenine, respectively. FGKO40 had a slightly reduced mutation rate for hprt mutants, suggesting reduced recovery of large deletions at this locus. Moreover, the rate of methotrexate resistance was elevated 2.5-fold in mutant cells compared to controls. Resistance to this drug is generally associated with amplification of the dhfr locus, suggesting FancG plays a role in this aspect of genome stability. We suggest that the defect in FGKO

  10. Maltol, a Food Flavoring Agent, Attenuates Acute Alcohol-Induced Oxidative Damage in Mice

    Directory of Open Access Journals (Sweden)

    Ye Han

    2015-01-01

    Full Text Available The purpose of this study was to evaluate the hepatoprotective effect of maltol, a food-flavoring agent, on alcohol-induced acute oxidative damage in mice. Maltol used in this study was isolated from red ginseng (Panax ginseng C.A Meyer and analyzed by high performance liquid chromatography (HPLC and mass spectrometry. For hepatoprotective activity in vivo, pretreatment with maltol (12.5, 25 and 50 mg/kg; 15 days drastically prevented the elevated activities of aspartate transaminase (AST, alanine transaminase (ALT, alkaline phosphatase (ALP and triglyceride (TG in serum and the levels of malondialdehyde (MDA, tumor necrosis factor-α (TNF-α, interleukin-1β (IL-1β in liver tissue (p < 0.05. Meanwhile, the levels of hepatic antioxidant, such as catalase (CAT, superoxide dismutase (SOD, glutathione peroxidase (GSH-Px were elevated by maltol pretreatment, compared to the alcohol group (p < 0.05. Histopathological examination revealed that maltol pretreatment significantly inhibited alcohol-induced hepatocyte apoptosis and fatty degeneration. Interestingly, pretreatment of maltol effectively relieved alcohol-induced oxidative damage in a dose-dependent manner. Maltol appeared to possess promising anti-oxidative and anti-inflammatory capacities. It was suggested that the hepatoprotective effect exhibited by maltol on alcohol-induced liver oxidative injury may be due to its potent antioxidant properties.

  11. Hypoxia-regulated therapeutic gene as a preemptive treatment strategy against ischemia/reperfusion tissue injury.

    Science.gov (United States)

    Pachori, Alok S; Melo, Luis G; Hart, Melanie L; Noiseux, Nicholas; Zhang, Lunan; Morello, Fulvio; Solomon, Scott D; Stahl, Gregory L; Pratt, Richard E; Dzau, Victor J

    2004-08-17

    Ischemia and reperfusion represent major mechanisms of tissue injury and organ failure. The timing of administration and the duration of action limit current treatment approaches using pharmacological agents. In this study, we have successfully developed a preemptive strategy for tissue protection using an adenoassociated vector system containing erythropoietin hypoxia response elements for ischemia-regulated expression of the therapeutic gene human heme-oxygenase-1 (hHO-1). We demonstrate that a single administration of this vector several weeks in advance of ischemia/reperfusion injury to multiple tissues such as heart, liver, and skeletal muscle yields rapid and timely induction of hHO-1 during ischemia that resulted in dramatic reduction in tissue damage. In addition, overexpression of therapeutic transgene prevented long-term pathological tissue remodeling and normalized tissue function. Application of this regulatable system using an endogenous physiological stimulus for expression of a therapeutic gene may be a feasible strategy for protecting tissues at risk of ischemia/reperfusion injury.

  12. Hypoxia-regulated therapeutic gene as a preemptive treatment strategy against ischemia/reperfusion tissue injury

    Science.gov (United States)

    Pachori, Alok S.; Melo, Luis G.; Hart, Melanie L.; Noiseux, Nicholas; Zhang, Lunan; Morello, Fulvio; Solomon, Scott D.; Stahl, Gregory L.; Pratt, Richard E.; Dzau, Victor J.

    2004-08-01

    Ischemia and reperfusion represent major mechanisms of tissue injury and organ failure. The timing of administration and the duration of action limit current treatment approaches using pharmacological agents. In this study, we have successfully developed a preemptive strategy for tissue protection using an adenoassociated vector system containing erythropoietin hypoxia response elements for ischemia-regulated expression of the therapeutic gene human heme-oxygenase-1 (hHO-1). We demonstrate that a single administration of this vector several weeks in advance of ischemia/reperfusion injury to multiple tissues such as heart, liver, and skeletal muscle yields rapid and timely induction of hHO-1 during ischemia that resulted in dramatic reduction in tissue damage. In addition, overexpression of therapeutic transgene prevented long-term pathological tissue remodeling and normalized tissue function. Application of this regulatable system using an endogenous physiological stimulus for expression of a therapeutic gene may be a feasible strategy for protecting tissues at risk of ischemia/reperfusion injury.

  13. Chemical warfare agents.

    Science.gov (United States)

    Kuca, Kamil; Pohanka, Miroslav

    2010-01-01

    Chemical warfare agents are compounds of different chemical structures. Simple molecules such as chlorine as well as complex structures such as ricin belong to this group. Nerve agents, vesicants, incapacitating agents, blood agents, lung-damaging agents, riot-control agents and several toxins are among chemical warfare agents. Although the use of these compounds is strictly prohibited, the possible misuse by terrorist groups is a reality nowadays. Owing to this fact, knowledge of the basic properties of these substances is of a high importance. This chapter briefly introduces the separate groups of chemical warfare agents together with their members and the potential therapy that should be applied in case someone is intoxicated by these agents.

  14. Poly-S-Nitrosated Albumin as a Safe and Effective Multifunctional Antitumor Agent: Characterization, Biochemistry and Possible Future Therapeutic Applications

    Directory of Open Access Journals (Sweden)

    Yu Ishima

    2013-01-01

    Full Text Available Nitric oxide (NO is a ubiquitous molecule involved in multiple cellular functions. Inappropriate production of NO may lead to disease states. To date, pharmacologically active compounds that release NO within the body, such as organic nitrates, have been used as therapeutic agents, but their efficacy is significantly limited by unwanted side effects. Therefore, novel NO donors with better pharmacological and pharmacokinetic properties are highly desirable. The S-nitrosothiol fraction in plasma is largely composed of endogenous S-nitrosated human serum albumin (Mono-SNO-HSA, and that is why we are testing whether this albumin form can be therapeutically useful. Recently, we developed SNO-HSA analogs such as SNO-HSA with many conjugated SNO groups (Poly-SNO-HSA which were prepared using chemical modification. Unexpectedly, we found striking inverse effects between Poly-SNO-HSA and Mono-SNO-HSA. Despite the fact that Mono-SNO-HSA inhibits apoptosis, Poly-SNO-HSA possesses very strong proapoptotic effects against tumor cells. Furthermore, Poly-SNO-HSA can reduce or perhaps completely eliminate the multidrug resistance often developed by cancer cells. In this review, we forward the possibility that Poly-SNO-HSA can be used as a safe and effective multifunctional antitumor agent.

  15. Influence of a pre-treatment with lithium, anabolic agents and hypertransfusion on the regeneration of the hematopoiesis in mice after radiation damage. Einfluss einer Vorbehandlung mit Lithium, Anabolikum und Hypertransfusion auf die Regeneration der Haematopoese bei der Maus nach Strahlenschaden

    Energy Technology Data Exchange (ETDEWEB)

    Bartenstein, P.

    1985-08-27

    In this work it was investigated, whether a week-long pre-treatment with Lithium carbonate, the anabolic agent Deca-Durabolin and syngeneic blood transfusions effected a stimulation, especially of the granulopoiesis, in mice and whether with these measures an increase in the number of pluripotent and myeloically determined stem cells CFUs and CFUc was attained. Further, the question was followed, to what extent these measures have a positive affect on the regeneration of hematopoiesis after radiation damage. Because these therapeutic interventions influence the hematopoiesis through various mechanisms, the detection of eventually present, additive effects should be done using a combination of these types of treatment.

  16. A germline FANCA alteration that is associated with increased sensitivity to DNA damaging agents.

    Science.gov (United States)

    Wilkes, David C; Sailer, Verena; Xue, Hui; Cheng, Hongwei; Collins, Colin C; Gleave, Martin; Wang, Yuzhuo; Demichelis, Francesca; Beltran, Himisha; Rubin, Mark A; Rickman, David S

    2017-09-01

    Defects in genes involved in DNA damage repair (DDR) pathway are emerging as novel biomarkers and targets for new prostate cancer drug therapies. A previous report revealed an association between an exceptional response to cisplatin treatment and a somatic loss of heterozygosity (LOH) of FANCA in a patient with metastatic prostate cancer who also harbored a germline FANCA variant (S1088F). Although germline FANCA mutations are the most frequent alterations in patients with Fanconi anemia, germline alterations are less common in prostate cancer. We hypothesized that the germline S1088F FANCA variant in combination with FANCA LOH was deleterious for FANCA function and contributed to the patient's exceptional response to cisplatin. We show that although it properly localizes to the nucleus, the S1088F FANCA mutant protein disrupts the FANC protein complex resulting in increased sensitivity to DNA damaging agents. Because molecular stratification is emerging as a strategy for treating men with metastatic, castrate-resistant prostate cancer harboring specific DDR gene defects, our findings suggest that more biomarker studies are needed to better define clinically relevant germline and somatic alterations. © 2017 Wilkes et al.; Published by Cold Spring Harbor Laboratory Press.

  17. Cyclic peptides as potential therapeutic agents for skin disorders.

    Science.gov (United States)

    Namjoshi, Sarika; Benson, Heather A E

    2010-01-01

    There is an increasing understanding of the role of peptides in normal skin function and skin disease. With this knowledge, there is significant interest in the application of peptides as therapeutics in skin disease or as cosmeceuticals to enhance skin appearance. In particular, antimicrobial peptides and those involved in inflammatory processes provide options for the development of new therapeutic directions in chronic skin conditions such as psoriasis and dermatitis. To exploit their potential, it is essential that these peptides are delivered to their site of action in active form and in sufficient quantity to provide the desired effect. Many polymers permeate the skin poorly and are vulnerable to enzymatic degradation. Synthesis of cyclic peptide derivatives can substantially alter the physicochemical characteristics of the peptide with the potential to improve its skin permeation. In addition, cyclization can stabilize the peptide structure and thereby increase its stability. This review describes the role of cyclic peptides in the skin, examples of current cyclic peptide therapeutic products, and the potential for cyclic peptides as dermatological therapeutics and cosmeceuticals.

  18. A Novel Single-Strand RNAi Therapeutic Agent Targeting the (Pro)renin Receptor Suppresses Ocular Inflammation.

    Science.gov (United States)

    Kanda, Atsuhiro; Ishizuka, Erdal Tan; Shibata, Atsushi; Matsumoto, Takahiro; Toyofuku, Hidekazu; Noda, Kousuke; Namba, Kenichi; Ishida, Susumu

    2017-06-16

    The receptor-associated prorenin system (RAPS) refers to the pathogenic mechanism whereby prorenin binding to the (pro)renin receptor [(P)RR] dually activates the tissue renin-angiotensin system (RAS) and RAS-independent intracellular signaling. Here we revealed significant upregulation of prorenin and soluble (P)RR levels in the vitreous fluid of patients with uveitis compared to non-inflammatory controls, together with a positive correlation between these RAPS components and monocyte chemotactic protein-1 among several upregulated cytokines. Moreover, we developed a novel single-strand RNAi agent, proline-modified short hairpin RNA directed against human and mouse (P)RR [(P)RR-PshRNA], and we determined its safety and efficacy in vitro and in vivo. Application of (P)RR-PshRNA in mice caused significant amelioration of acute (uveitic) and chronic (diabetic) models of ocular inflammation with no apparent adverse effects. Our findings demonstrate the significant implication of RAPS in the pathogenesis of human uveitis and the potential usefulness of (P)RR-PshRNA as a therapeutic agent to reduce ocular inflammation. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  19. Radiomodulatory potential of hydroalcoholic extract of a medicinal plant Cynodon dactylon (Family: Poaceae), against radiation-induced cytogenetic damage

    International Nuclear Information System (INIS)

    Satish Rao, B.S.; Upadhya, D.; Adiga, S.K.

    2007-01-01

    The exposure of humans to ionizing radiations may be advertently by routine diagnostic and therapeutic purposes or inadvertently during natural, occupational and nuclear accident situations. Therefore, in order to overcome the deleterious biological effects of radiation several chemical agents have been studied for their radioprotective potential. The medicinal plants being one of the resources for such clinically important natural agents, used extensively in several drug discovery related research. Here the radiomodulatory potential of hydroalcoholic extract of a medicinal plant Cynodon dactylon (Family: Poaceae), against radiation-induced cytogenetic damage was analyzed using Chinese hamster fibroblast cells (V79) and human peripheral blood lymphocytes (HPBLs) growing in vitro is reported

  20. The effect of interstitial pressure on therapeutic agent transport: coupling with the tumor blood and lymphatic vascular systems.

    Science.gov (United States)

    Wu, Min; Frieboes, Hermann B; Chaplain, Mark A J; McDougall, Steven R; Cristini, Vittorio; Lowengrub, John S

    2014-08-21

    Vascularized tumor growth is characterized by both abnormal interstitial fluid flow and the associated interstitial fluid pressure (IFP). Here, we study the effect that these conditions have on the transport of therapeutic agents during chemotherapy. We apply our recently developed vascular tumor growth model which couples a continuous growth component with a discrete angiogenesis model to show that hypertensive IFP is a physical barrier that may hinder vascular extravasation of agents through transvascular fluid flux convection, which drives the agents away from the tumor. This result is consistent with previous work using simpler models without blood flow or lymphatic drainage. We consider the vascular/interstitial/lymphatic fluid dynamics to show that tumors with larger lymphatic resistance increase the agent concentration more rapidly while also experiencing faster washout. In contrast, tumors with smaller lymphatic resistance accumulate less agents but are able to retain them for a longer time. The agent availability (area-under-the curve, or AUC) increases for less permeable agents as lymphatic resistance increases, and correspondingly decreases for more permeable agents. We also investigate the effect of vascular pathologies on agent transport. We show that elevated vascular hydraulic conductivity contributes to the highest AUC when the agent is less permeable, but to lower AUC when the agent is more permeable. We find that elevated interstitial hydraulic conductivity contributes to low AUC in general regardless of the transvascular agent transport capability. We also couple the agent transport with the tumor dynamics to simulate chemotherapy with the same vascularized tumor under different vascular pathologies. We show that tumors with an elevated interstitial hydraulic conductivity alone require the strongest dosage to shrink. We further show that tumors with elevated vascular hydraulic conductivity are more hypoxic during therapy and that the response

  1. Hypersensitivity of hypoxia grown Mycobacterium smegmatis to DNA damaging agents: implications of the DNA repair deficiencies in attenuation of mycobacteria.

    Science.gov (United States)

    Rex, Kervin; Kurthkoti, Krishna; Varshney, Umesh

    2013-10-01

    Mycobacteria are an important group of pathogenic bacteria. We generated a series of DNA repair deficient strains of Mycobacterium smegmatis, a model organism, to understand the importance of various DNA repair proteins (UvrB, Ung, UdgB, MutY and Fpg) in survival of the pathogenic strains. Here, we compared tolerance of the M. smegmatis strains to genotoxic stress (ROS and RNI) under aerobic, hypoxic and recovery conditions of growth by monitoring their survival. We show an increased susceptibility of mycobacteria to genotoxic stress under hypoxia. UvrB deficiency led to high susceptibility of M. smegmatis to the DNA damaging agents. Ung was second in importance in strains with single deficiencies. Interestingly, we observed that while deficiency of UdgB had only a minor impact on the strain's susceptibility, its combination with Ung deficiency resulted in severe consequences on the strain's survival under genotoxic stress suggesting a strong interdependence of different DNA repair pathways in safeguarding genomic integrity. Our observations reinforce the possibility of targeting DNA repair processes in mycobacteria for therapeutic intervention during active growth and latency phase of the pathogen. High susceptibility of the UvrB, or the Ung/UdgB deficient strains to genotoxic stress may be exploited in generation of attenuated strains of mycobacteria. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  2. Alkylating chemotherapeutic agents cyclophosphamide and melphalan cause functional injury to human bone marrow-derived mesenchymal stem cells.

    Science.gov (United States)

    Kemp, Kevin; Morse, Ruth; Sanders, Kelly; Hows, Jill; Donaldson, Craig

    2011-07-01

    The adverse effects of melphalan and cyclophosphamide on hematopoietic stem cells are well-known; however, the effects on the mesenchymal stem cells (MSCs) residing in the bone marrow are less well characterised. Examining the effects of chemotherapeutic agents on patient MSCs in vivo is difficult due to variability in patients and differences in the drug combinations used, both of which could have implications on MSC function. As drugs are not commonly used as single agents during high-dose chemotherapy (HDC) regimens, there is a lack of data comparing the short- or long-term effects these drugs have on patients post treatment. To help address these problems, the effects of the alkylating chemotherapeutic agents cyclophosphamide and melphalan on human bone marrow MSCs were evaluated in vitro. Within this study, the exposure of MSCs to the chemotherapeutic agents cyclophosphamide or melphalan had strong negative effects on MSC expansion and CD44 expression. In addition, changes were seen in the ability of MSCs to support hematopoietic cell migration and repopulation. These observations therefore highlight potential disadvantages in the use of autologous MSCs in chemotherapeutically pre-treated patients for future therapeutic strategies. Furthermore, this study suggests that if the damage caused by chemotherapeutic agents to marrow MSCs is substantial, it would be logical to use cultured allogeneic MSCs therapeutically to assist or repair the marrow microenvironment after HDC.

  3. Neuroinflammation in the pathogenesis of Alzheimer´s disease. A rational framework for the search of novel therapeutic approaches

    Directory of Open Access Journals (Sweden)

    Ricardo Benjamin Maccioni

    2014-04-01

    Full Text Available Alzheimer disease (AD is the most common cause of dementia in people over 60 years old. The molecular and cellular alterations that trigger this disease are still diffuse, one of the reasons for the delay in finding an effective treatment. In the search for new targets to search for novel therapeutic avenues, clinical studies in patients who used anti-inflammatory drugs indicating a lower incidence of AD have been of value to support the neuroinflammatory hypothesis of the neurodegenerative processes and the role of innate immunity in this disease. Neuroinflammation appears to occur as a consequence of a series of damage signals, including trauma, infection, oxidative agents, redox iron, oligomers of tau and beta amyloid, etc. In this context, our theory of Neuroimmunomodulation focus on the link between neuronal damage and brain inflammatory process, mediated by the progressive activation of astrocytes and microglial cells with the consequent overproduction of proinflammatory agents. Here, we discuss about the role of microglial and astrocytic cells, the principal agents in neuroinflammation process, in the development of neurodegenerative diseases such as AD. In this context, we also evaluated the potential relevance of natural anti-inflammatory components, which include curcumin and the novel Andean Compound, as agents for AD prevention and as a coadjuvant for AD treatments.

  4. Complex responses to alkylating agents

    International Nuclear Information System (INIS)

    Samson, L.D.

    2003-01-01

    Using Affymetrix oligonucleotide GeneChip analysis, we previously found that, upon exposure to the simple alkylating agent methylmethane sulfonate, the transcript levels for about one third of the Saccharomyces cerevisiae genome (∼2,000 transcripts) are induced or repressed during the first hour or two after exposure. In order to determine whether the responsiveness of these genes has any relevance to the protection of cells against alkylating agents we have undertaken several follow-up studies. First, we explored the specificity of this global transcriptional response to MMS by measuring the global response of S. cerevisiae to a broad range of agents that are known to induce DNA damage. We found that each agent produced a very different mRNA transcript profile, even though the exposure doses produced similar levels of toxicity. We also found that the selection of genes that respond to MMS is highly dependent upon what cell cycle phase the cells are in at the time of exposure. Computational clustering analysis of the dataset derived from a large number of exposures identified several promoter motifs that are likely to control some of the regulons that comprise this large set of genes that are responsive to DNA damaging agents. However, it should be noted that these agents damage cellular components other than DNA, and that the responsiveness of each gene need not be in response to DNA damage per se. We have also begun to study the response of other organisms to alkylating agents, and these include E. coli, cultured mouse and human cells, and mice. Finally, we have developed a high throughput phenotypic screening method to interrogate the role of all non-essential S. cerevisiae genes (about 4,800) in protecting S. cerevisiae against the deleterious effects of alkylating agents; we have termed this analysis 'genomic phenotyping'. This study has uncovered a plethora of new pathways that play a role in the recovery of eukaryotic cells after exposure to toxic

  5. Endogenous c-Myc is essential for p53-induced apoptosis in response to DNA damage in vivo.

    Science.gov (United States)

    Phesse, T J; Myant, K B; Cole, A M; Ridgway, R A; Pearson, H; Muncan, V; van den Brink, G R; Vousden, K H; Sears, R; Vassilev, L T; Clarke, A R; Sansom, O J

    2014-06-01

    Recent studies have suggested that C-MYC may be an excellent therapeutic cancer target and a number of new agents targeting C-MYC are in preclinical development. Given most therapeutic regimes would combine C-MYC inhibition with genotoxic damage, it is important to assess the importance of C-MYC function for DNA damage signalling in vivo. In this study, we have conditionally deleted the c-Myc gene in the adult murine intestine and investigated the apoptotic response of intestinal enterocytes to DNA damage. Remarkably, c-Myc deletion completely abrogated the immediate wave of apoptosis following both ionizing irradiation and cisplatin treatment, recapitulating the phenotype of p53 deficiency in the intestine. Consistent with this, c-Myc-deficient intestinal enterocytes did not upregulate p53. Mechanistically, this was linked to an upregulation of the E3 Ubiquitin ligase Mdm2, which targets p53 for degradation in c-Myc-deficient intestinal enterocytes. Further, low level overexpression of c-Myc, which does not impact on basal levels of apoptosis, elicited sustained apoptosis in response to DNA damage, suggesting c-Myc activity acts as a crucial cell survival rheostat following DNA damage. We also identify the importance of MYC during DNA damage-induced apoptosis in several other tissues, including the thymus and spleen, using systemic deletion of c-Myc throughout the adult mouse. Together, we have elucidated for the first time in vivo an essential role for endogenous c-Myc in signalling DNA damage-induced apoptosis through the control of the p53 tumour suppressor protein.

  6. Base damage within single-strand DNA underlies in vivo hypermutability induced by a ubiquitous environmental agent.

    Directory of Open Access Journals (Sweden)

    Kin Chan

    Full Text Available Chromosomal DNA must be in single-strand form for important transactions such as replication, transcription, and recombination to occur. The single-strand DNA (ssDNA is more prone to damage than double-strand DNA (dsDNA, due to greater exposure of chemically reactive moieties in the nitrogenous bases. Thus, there can be agents that damage regions of ssDNA in vivo while being inert toward dsDNA. To assess the potential hazard posed by such agents, we devised an ssDNA-specific mutagenesis reporter system in budding yeast. The reporter strains bear the cdc13-1 temperature-sensitive mutation, such that shifting to 37°C results in telomere uncapping and ensuing 5' to 3' enzymatic resection. This exposes the reporter region, containing three closely-spaced reporter genes, as a long 3' ssDNA overhang. We validated the ability of the system to detect mutagenic damage within ssDNA by expressing a modified human single-strand specific cytosine deaminase, APOBEC3G. APOBEC3G induced a high density of substitutions at cytosines in the ssDNA overhang strand, resulting in frequent, simultaneous inactivation of two reporter genes. We then examined the mutagenicity of sulfites, a class of reactive sulfur oxides to which humans are exposed frequently via respiration and food intake. Sulfites, at a concentration similar to that found in some foods, induced a high density of mutations, almost always as substitutions at cytosines in the ssDNA overhang strand, resulting in simultaneous inactivation of at least two reporter genes. Furthermore, sulfites formed a long-lived adducted 2'-deoxyuracil intermediate in DNA that was resistant to excision by uracil-DNA N-glycosylase. This intermediate was bypassed by error-prone translesion DNA synthesis, frequently involving Pol ζ, during repair synthesis. Our results suggest that sulfite-induced lesions in DNA can be particularly deleterious, since cells might not possess the means to repair or bypass such lesions

  7. Potencial terapéutico de los canabinoides como neuroprotectores Therapeutical potential of cannabinoids as neuroprotective agents

    Directory of Open Access Journals (Sweden)

    Laymi Martínez García

    2007-12-01

    Full Text Available La planta Cannabis sativa L. o cáñamo ha captado desde tiempos antiquísimos la atención del hombre en el campo de la salud y terapéutica humanas y todavía, a inicios del siglo XXI, continúa despertando polémicas en la comunidad científica como fuente natural y en el estudio y aplicación de sus derivados. Desde el punto de vista fitoquímico se han descrito más de 70 derivados de tipo canabinoide farmacológicamente activos sobre el sistema nervioso central. En la actualidad se han generado valiosísimas fuentes de información que relacionan la especie botánica Cannabis sativa L. y sus metabolitos secundarios con la medicina (tratamiento terapéutico, farmacología (modelos experimentales y química sintética (diseño y generación de nuevas estructuras, las cuales avalan la importancia del estudio de esta planta, sus extractos, metabolitos y precursores como fuente de agentes terapéuticos. Por tal motivo se presenta una revisión de la información existente sobre las potenciales implicaciones terapéuticas de sistemas moleculares canabinoidales (endógenos, naturales y sintéticos en el tratamiento de enfermedades neurodegenerativas del sistema nervioso central, que incluye: conceptos de tipos de canabinoides, sistemas de receptores canabinoides CB1 y CB2 y evidencias preclínicas de los efectos neuroprotectores de canabinoides desde 1970 hasta el 2005Cannabis sativa L. or cáñamo has focused man's attention for its therapeutical and medical application since ancient times, and yet, at the beginning of XXI century, this plant continues being polemic for the scientific community as a natural source and in the study and application of its derivatives. More than 70 cannabinoid compounds with pharmacological action on the central nervous system have been phytochemically described. At present, a great amount of valuable information and experimental data have been generated that correlate Cannabis sativa and its secondary metabolites

  8. Effect of curing agents on the oxidative and nitrosative damage to meat proteins during processing of fermented sausages.

    Science.gov (United States)

    Villaverde, A; Morcuende, D; Estévez, M

    2014-07-01

    The effect of increasing concentrations of curing agents, ascorbate (0, 250, and 500 ppm), and nitrite (0, 75, and 150 ppm), on the oxidative and nitrosative damage to proteins during processing of fermented sausages was studied. The potential influence of these reactions on color and texture of the fermented sausages was also addressed. Nitrite had a pro-oxidant effect on tryptophan depletion and promoted the formation of protein carbonyls and Schiff bases. The nitration degree in the fermented sausages was also dependent on nitrite concentration. On the other hand, ascorbate acted as an efficient inhibitor of the oxidative and nitrosative damage to meat proteins. As expected, nitrite clearly favored the formation of the cured red color and ascorbate acted as an enhancer of color formation. Nitrite content was positively correlated with hardness. The chemistry behind the action of nitrite and ascorbate on muscle proteins during meat fermentation is thoroughly discussed. The results suggest that ascorbate (500 ppm) may be required to compensate the pro-oxidant impact of nitrite on meat proteins. This study provides insight on the action of curing agents on meat proteins during processing of fermented sausages. This chemistry background provides understanding of the potential influence of the oxidative and nitrosative damage to proteins on the quality of processed muscle foods. The study provides novel information on the impact of the combination of nitrite and ascorbate on the chemical deterioration of proteins and the influence on particular quality traits of fermented sausages. These data may be of interest for the design of cured muscle foods of enhanced quality. © 2014 Institute of Food Technologists®

  9. DNA damage induced in mouse peritoneal exudate cells after in vivo administration of chemical and physical agents as determined by alkaline elution

    International Nuclear Information System (INIS)

    Nishi, Yoshisuke; Miyanaga, Kumiko; Sato, Sei-ichi; Inui, Naomichi

    1990-01-01

    The alkaline elution technique for detecting DNA strand breaks has been applied to the study of DNA damage in mouse peritoneal exudate cells resulting from the in vivo administration of chemical and physical agents. The direct methylating agents methyl methanesulphonate and N-methyl-N-nitrosourea induced extensive breakage in samples taken 2 h after administration. The direct ethylating agents ethyl methanesulphonate and N-ethyl-N-nitrosourea also induced DNA strand breaks, but to a lesser extent than the methylating agents. The indirect methylating agent dimethylnitrosamine showed hardly any effect in this system. A weak but positive response was observed upon treatment with the anti-neoplastic alkylating agent procarbazine hydrochloride. The whole-body irradiation of mice with 60 Co γ-rays also induced DNA strand breaks. The elution profiles for γ-ray irradiation were different from those of alkylating agents, and indicate that alkylating agents produce many more secondary lesions leading to DNA strand breaks than γ-rays. N-methyl-N-nitrosourea produced slightly more DNA strand breaks in mutagen-sensitive mice, which are derived from the CD-1 strain, than in ICR mice. (Author)

  10. DNA damage induced in mouse peritoneal exudate cells after in vivo administration of chemical and physical agents as determined by alkaline elution

    Energy Technology Data Exchange (ETDEWEB)

    Nishi, Yoshisuke (Japan Tobacco Inc., Yokohama (Japan). Central Research Inst.); Miyanaga, Kumiko; Sato, Sei-ichi (Japan Tobacco Inc., Hatano, Kanagawa (Japan). Toxicology Research Lab.); Inui, Naomichi (Japan Tobacco Inc., Yokohama, Kanagawa (Japan). Pharmaceutical Research Labs.)

    1990-01-01

    The alkaline elution technique for detecting DNA strand breaks has been applied to the study of DNA damage in mouse peritoneal exudate cells resulting from the in vivo administration of chemical and physical agents. The direct methylating agents methyl methanesulphonate and N-methyl-N-nitrosourea induced extensive breakage in samples taken 2 h after administration. The direct ethylating agents ethyl methanesulphonate and N-ethyl-N-nitrosourea also induced DNA strand breaks, but to a lesser extent than the methylating agents. The indirect methylating agent dimethylnitrosamine showed hardly any effect in this system. A weak but positive response was observed upon treatment with the anti-neoplastic alkylating agent procarbazine hydrochloride. The whole-body irradiation of mice with {sup 60}Co {gamma}-rays also induced DNA strand breaks. The elution profiles for {gamma}-ray irradiation were different from those of alkylating agents, and indicate that alkylating agents produce many more secondary lesions leading to DNA strand breaks than {gamma}-rays. N-methyl-N-nitrosourea produced slightly more DNA strand breaks in mutagen-sensitive mice, which are derived from the CD-1 strain, than in ICR mice. (Author).

  11. Medical ozone therapy as a potential treatment modality for regeneration of damaged articular cartilage in osteoarthritis

    Directory of Open Access Journals (Sweden)

    Sello Lebohang Manoto

    2018-05-01

    Full Text Available Osteoarthritis (OA is the most common degenerative joint disease and a growing health problem affecting more than half of the population over the age of 65. It is characterized by inflammation in the cartilage and synovium, resulting in the loss of joint structure and progressive damage to the cartilage. Many pro-inflammatory mediators are elevated in OA, including reactive oxygen species (ROS such as nitric oxide (NO and hydrogen peroxide (H2O2. Damaged articular cartilage remains a challenge to treat due to the limited self-healing capacity of the tissue and unsuccessful biological interventions. This highlights the need for better therapeutic strategies to heal damaged articular cartilage. Ozone (O3 therapy has been shown to have positive results in the treatment of OA; however the use of O3 therapy as a therapeutic agent is controversial. There is a perception that O3 is always toxic, whereas evidence indicates that when it is applied following a specified method, O3 can be effective in the treatment of degenerative diseases. The mechanism of action of O3 therapy in OA is not fully understood and this review summarizes the use of O3 therapy in the treatment of damaged articular cartilage in OA. Keywords: Osteoarthritis (OA, Articular cartilage, Ozone (O3 therapy, Reactive oxygen species (ROS

  12. Regulation of radiation protective agents on cell damage induced by reactive oxygen species

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jeong Hee; Lee, Si Eun; Ju, Eun Mi; Gao, Eu Feng [Kyung Hee University, Seoul (Korea)

    2002-04-01

    In this study, we developed candidates of new radio-protective agents and elucidated the regulation mechanism of these candidates on cell damage induced by reactive oxygen species. The methanol extracts and ethylacetate fractions of NP-1, NP-5, NP-7, NP-11, NP-12 and NP-14 showed higher radical scavenging activity. The extracts of NP-7, NP-12 and NP-14 showed strong protective effect against oxidative damage induced by UV and H{sub 2}O{sub 2}. The most of samples enhanced SOD, CAT and GPX activity in V79-4 cells. The protective effect of samples on H{sub 2}O{sub 2}-induced apoptosis was observed with microscope and flow cytometer. Cells exposed to H{sub 2}O{sub 2} exhibit distinct morphological features of programmed cell death, such as nuclear fragmentation and increase in the percentage of cells with a sub-G1 DNA content. However, cells which was pretreated with samples significantly reduced the characteristics of apoptotic cells. Their morphological observation and DNA profiles were similar to those of the control cells. NP-14 which had excellent antioxidant activity restored G2/M arrest induced by oxidative stress. These data suggested that natural medicinal plants protected H{sub 2}O{sub 2}-induced apoptosis. 42 refs., 29 figs., 11 tabs. (Author)

  13. Formulation and acoustic studies of a new phase-shift agent for diagnostic and therapeutic ultrasound.

    Science.gov (United States)

    Sheeran, Paul S; Luois, Samantha; Dayton, Paul A; Matsunaga, Terry O

    2011-09-06

    Recent efforts in the area of acoustic droplet vaporization with the objective of designing extravascular ultrasound contrast agents has led to the development of stabilized, lipid-encapsulated nanodroplets of the highly volatile compound decafluorobutane (DFB). We developed two methods of generating DFB droplets, the first of which involves condensing DFB gas (boiling point from -1.1 to -2 °C) followed by extrusion with a lipid formulation in HEPES buffer. Acoustic droplet vaporization of micrometer-sized lipid-coated droplets at diagnostic ultrasound frequencies and mechanical indices were confirmed optically. In our second formulation methodology, we demonstrate the formulation of submicrometer-sized lipid-coated nanodroplets based upon condensation of preformed microbubbles containing DFB. The droplets are routinely in the 200-300 nm range and yield microbubbles on the order of 1-5 μm once vaporized, consistent with ideal gas law expansion predictions. The simple and effective nature of this methodology allows for the development of a variety of different formulations that can be used for imaging, drug and gene delivery, and therapy. This study is the first to our knowledge to demonstrate both a method of generating ADV agents by microbubble condensation and formulation of primarily submicrometer droplets of decafluorobutane that remain stable at physiological temperatures. Finally, activation of DFB nanodroplets is demonstrated using pressures within the FDA guidelines for diagnostic imaging, which may minimize the potential for bioeffects in humans. This methodology offers a new means of developing extravascular contrast agents for diagnostic and therapeutic applications. © 2011 American Chemical Society

  14. Targeting Potassium Channels for Increasing Delivery of Imaging Agents and Therapeutics to Brain Tumors

    Directory of Open Access Journals (Sweden)

    Nagendra Sanyasihally Ningaraj

    2013-05-01

    Full Text Available Every year in the US, 20,000 new primary and nearly 200,000 metastatic brain tumor cases are reported. The cerebral microvessels/ capillaries that form the blood–brain barrier (BBB not only protect the brain from toxic agents in the blood but also pose a significant hindrance to the delivery of small and large therapeutic molecules. Different strategies have been employed to circumvent the physiological barrier posed by blood-brain tumor barrier (BTB. Studies in our laboratory have identified significant differences in the expression levels of certain genes and proteins between normal and brain tumor capillary endothelial cells. In this study, we validated the non-invasive and clinically relevant Dynamic Contrast Enhancing-Magnetic Resonance Imaging (DCE-MRI method with invasive, clinically irrelevant but highly accurate Quantitative Autoradiography (QAR method using rat glioma model. We also showed that DCE-MRI metric of tissue vessel perfusion-permeability is sensitive to changes in blood vessel permeability following administration of calcium-activated potassium (BKCa channel activator NS-1619. Our results show that human gliomas and brain tumor endothelial cells that overexpress BKCa channels can be targeted for increased BTB permeability for MRI enhancing agents to brain tumors. We conclude that monitoring the outcome of increased MRI enhancing agents’ delivery to microsatellites and leading tumor edges in glioma patients would lead to beneficial clinical outcome.

  15. Radiological and physiological studies on the role of some therapeutic agents used for internal decontamination of radionuclides from male albino rats

    International Nuclear Information System (INIS)

    Mangood, S.A.

    2008-01-01

    With the earths increasing nuclear arsenal and the growing use of nuclear energy, the possibility of radiological accidents involving release of radioactive materials, internal contamination may consequently occurs via inhalation, ingestion or absorption of radioisotopes.Therefore, the present work was oriented to deal with four topics related to the internal decontamination of two of the most widely used isotopes, namely 134 Cs and 60 Co from contaminated rats:-In vitro study aimed to select agents that can strongly bind the two metal ions and elucidate the best conditions and the factors affecting this binding. The tested agents were bentonite, vermiculite and Prussian blue (PB). The sorption capacity of PB and vermiculite for both metal ions was high and equivalent to more than 10 11 Bq 137 Cs or 60 Co per gram sorbent. As bentonite has lower capacity to both isotopes, further in vivo experiments were performed with PB and vermiculite.-In vivo studies, via 5 groups of rats, devoted to investigate the kinetics of excretion of 134 Cs and/or 60 Co from contaminated rats. The biological half lives of excretion, excretion stages for both isotopes and the effect of route of entry on the excretion were estimated.-In vivo studies aimed to investigate the effectiveness of PB + vermiculite and CaDTPA as therapeutic agents for accelerating the elimination of 134 Cs and/or 60 Co from contaminated rats. The study was performed via 6 groups of rats given different regimes of therapy. The results showed the high efficiency of PB + vermiculite for accelerating elimination of 134 Cs and orally administrated 60 Co while CaDTPA succeeded in accelerating intraperitoneally administrated 60 Co. The study proved that oral administration of PB + vermiculite and injection with CaDTPA at the same time is very effective in accelerating elimination of both contaminants simultaneously.-The physiological studies aimed to evaluate the hazardous effects of 134 Cs and/or 60 Co incorporation and

  16. Folic acid tagged nanoceria as a novel therapeutic agent in ovarian cancer

    International Nuclear Information System (INIS)

    Hijaz, Miriana; Das, Soumen; Mert, Ismail; Gupta, Ankur; Al-Wahab, Zaid; Tebbe, Calvin; Dar, Sajad; Chhina, Jasdeep; Giri, Shailendra; Munkarah, Adnan; Seal, Sudipta; Rattan, Ramandeep

    2016-01-01

    Nanomedicine is a very promising field and nanomedical drugs have recently been used as therapeutic agents against cancer. In a previous study, we showed that Nanoceria (NCe), nanoparticles of cerium oxide, significantly inhibited production of reactive oxygen species, cell migration and invasion of ovarian cancer cells in vitro, without affecting cell proliferation and significantly reduced tumor growth in an ovarian cancer xenograft nude model. Increased expression of folate receptor-α, an isoform of membrane-bound folate receptors, has been described in ovarian cancer. To enable NCe to specifically target ovarian cancer cells, we conjugated nanoceria to folic acid (NCe-FA). Our aim was to investigate the pre-clinical efficacy of NCe-FA alone and in combination with Cisplatin. Ovarian cancer cell lines were treated with NCe or NCe-FA. Cell viability was assessed by MTT and colony forming units. In vivo studies were carried in A2780 generated mouse xenografts treated with 0.1 mg/Kg NCe, 0.1 mg/Kg; NCe-FA and cisplatinum, 4 mg/Kg by intra-peritoneal injections. Tumor weights and burden scores were determined. Immunohistochemistry and toxicity assays were used to evaluate treatment effects. We show that folic acid conjugation of NCe increased the cellular NCe internalization and inhibited cell proliferation. Mice treated with NCe-FA had a lower tumor burden compared to NCe, without any vital organ toxicity. Combination of NCe-FA with cisplatinum decreased the tumor burden more significantly. Moreover, NCe-FA was also effective in reducing proliferation and angiogenesis in the xenograft mouse model. Thus, specific targeting of ovarian cancer cells by NCe-FA holds great potential as an effective therapeutic alone or in combination with standard chemotherapy. The online version of this article (doi:10.1186/s12885-016-2206-4) contains supplementary material, which is available to authorized users

  17. Dendrimer advances for the central nervous system delivery of therapeutics.

    Science.gov (United States)

    Xu, Leyuan; Zhang, Hao; Wu, Yue

    2014-01-15

    The effectiveness of noninvasive treatment for central nervous system (CNS) diseases is generally limited by the poor access of therapeutic agents into the CNS. Most CNS drugs cannot permeate into the brain parenchyma because of the blood-brain barrier (BBB), and overcoming this has become one of the most significant challenges in the development of CNS therapeutics. Rapid advances in nanotechnology have provided promising solutions to this challenge. This review discusses the latest applications of dendrimers in the treatment of CNS diseases with an emphasis on brain tumors. Dendrimer-mediated drug delivery, imaging, and diagnosis are also reviewed. The toxicity, biodistribution, and transport mechanisms in dendrimer-mediated delivery of CNS therapeutic agents bypassing or crossing the BBB are also discussed. Future directions and major challenges of dendrimer-mediated delivery of CNS therapeutic agents are included.

  18. Photodynamic therapy induced vascular damage: an overview of experimental PDT

    International Nuclear Information System (INIS)

    Wang, W; Moriyama, L T; Bagnato, V S

    2013-01-01

    Photodynamic therapy (PDT) has been developed as one of the most important therapeutic options in the treatment of cancer and other diseases. By resorting to the photosensitizer and light, which convert oxygen into cytotoxic reactive oxygen species (ROS), PDT will induce vascular damage and direct tumor cell killing. Another consequence of PDT is the microvascular stasis, which results in hypoxia and further produces tumor regression. To improve the treatment with PDT, three promising strategies are currently attracting much interest: (1) the combination of PDT and anti-angiogenesis agents, which more effectively prevent the proliferation of endothelial cells and the formation of new blood vessels; (2) the nanoparticle-assisted delivery of photosensitizer, which makes the photosensitizer more localized in tumor sites and thus renders minimal damage to the normal tissues; (3) the application of intravascular PDT, which can avoid the loss of energy during the transmission and expose the target area directly. Here we aim to review the important findings on vascular damage by PDT on mice. The combination of PDT with other approaches as well as its effect on cancer photomedicine are also reviewed. (review)

  19. TRAIL: A Novel Therapeutic Agent for Prostate Cancer

    National Research Council Canada - National Science Library

    Li, Honglin

    2002-01-01

    This study aims to elucidate the signaling pathway of TRAIL-mediated apoptosis in prostate cancer cells, and to examine the therapeutic effect of TRAIL on prostate cancer cells in vitro and in vivo...

  20. TRAIL: A Novel Therapeutic Agent for Prostate Cancer

    National Research Council Canada - National Science Library

    Li, Honglin

    2004-01-01

    This study aims to elucidate the signaling pathway of TRAIL-mediated apoptosis in prostate cancer cells, and to examine the therapeutic effect of TRAIL on prostate cancer cells in vitro and in vivo...

  1. TRAIL: A Novel Therapeutic Agent for Prostate Cancer

    National Research Council Canada - National Science Library

    Li, Honglin

    2003-01-01

    This study aims to elucidate the signaling pathway of TRAIL-mediated apoptosis in prostate cancer cells, and to examine the therapeutic effect of TRAIL on prostate cancer cells in vitro and in vivo...

  2. Technical cooperation for the wider uses of Ho-166 therapeutic agents in European countries

    CERN Document Server

    Park, K B; Choi, S M; Han, K H; Hong, Y D; Park, W W; Shin, B C

    2002-01-01

    Czech has put their priority in developing the radiopharmaceuticals based on reactor produced Ho-166 and a related fabrication will be extended to other EU conturies including Germany, France, etc after a development of project. The collaboration will be based on the mutual agreement for developing the between research institutes, industries and academic institutes and further researches should be followed by the issue of developing radiopharmaceuticals using Ho-166. To strengthen the collaboration, detailed discussions for the practical collaboration have been made through the visitation to the research institution of each counter part. For implementing the collaboration between NPI and KAERI, an institutional basis technical cooperation agreement(TCA) will be concluded. Furthermore, agreement for the substantial collaboration on Ho-166 related researches will be made after the conclusion of the TCA. It will accelerate the commercialization of KAERI developed Ho-166 therapeutic agents into other European cou...

  3. Neuroprotection for Nerve Agent-Induced Brain Damage

    National Research Council Canada - National Science Library

    Newmark, Jonathan; Ballough, Gerald P; Filbert, Margaret G

    2002-01-01

    ... secondary to exposure to nerve agents. Preliminary work in this laboratory has demonstrated proof of concept using a compound not yet approved for clinical use by the US Food and Drug Administration...

  4. In-silico analysis of heat shock protein 47 for identifying the novel therapeutic agents in the management of oral submucous fibrosis

    Directory of Open Access Journals (Sweden)

    Jayasankar P Pillai

    2014-01-01

    Conclusion: HSP47 can be a potential candidate to target, in order to control the production of abundance collagen in OSF. Hence, the binding sites of HSP47 with collagen are identified and some natural compounds with a potential to bind with these binding receptors are also recognized. These natural compounds might act as anti-HSP47 lead molecules in designing novel therapeutic agents for OSF, which are so far unavailable.

  5. Attenuation of Oxidative Damage by Boerhaavia diffusa L. Against Different Neurotoxic Agents in Rat Brain Homogenate.

    Science.gov (United States)

    Ayyappan, Prathapan; Palayyan, Salin Raj; Kozhiparambil Gopalan, Raghu

    2016-01-01

    Due to a high rate of oxidative metabolic activity in the brain, intense production of reactive oxygen metabolite occurs, and the subsequent generation of free radicals is implicated in the pathogenesis of traumatic brain injury, epilepsy, and ischemia as well as chronic neurodegenerative diseases. In the present study, protective effects of polyphenol rich ethanolic extract of Boerhaavia diffusa (BDE), a neuroprotective edible medicinal plant against oxidative stress induced by different neurotoxic agents, were evaluated. BDE was tested against quinolinic acid (QA), 3-nitropropionic acid (NPA), sodium nitroprusside (SNP), and Fe (II)/EDTA complex induced oxidative stress in rat brain homogenates. QA, NPA, SNP, and Fe (II)/EDTA treatment caused an increased level of thiobarbituric acid reactive substances (TBARS) in brain homogenates along with a decline in the activities of antioxidant enzymes. BDE treatment significantly decreased the production of TBARS (p cerebral cortex. Inhibitory potential of BDE against deoxyribose degradation (IC50 value 38.91 ± 0.12 μg/ml) shows that BDE can protect hydroxyl radical induced DNA damage in the tissues. Therefore, B. diffusa had high antioxidant potential that could inhibit the oxidative stress induced by different neurotoxic agents in brain. Since many of the neurological disorders are associated with free radical injury, these data may imply that B. diffusa, functioning as an antioxidant agent, may be beneficial for reducing various neurodegenerative complications.

  6. PYTHIOSIS: A THERAPEUTIC APPROACH

    Directory of Open Access Journals (Sweden)

    C. M. C. Falcão

    2015-10-01

    Full Text Available Pythiosis, a disease caused by the oomycete Pythium insidiosum, often presents inefficient response to chemotherapy. It is a consensus that, in spite the several therapeutic protocols, a combination of surgery, chemotherapy and immunotherapy should be used. Surgical excision requires the removal of the entire affected area, with a wide margin of safety. The use of antifungal drugs has resulted in variable results, both in vitro and in vivo, and presents low therapeutic efficiency due to differences in the agent characteristics, which differ from true fungi. Immunotherapy is a non-invasive alternative for the treatment of pythiosis, which aims at modifying the immune response of the host, thereby producing an effective response to the agent. Photodynamic therapy has emerged as a promising technique, with good activity against P. insidiosum in vitro and in vivo. However, more studies are necessary to increase the efficiency of the current treatment protocols and consequently improve the cure rates. This paper aims to conduct a review covering the conventional and recent therapeutic methods against P. insidiosum infections

  7. Pharmacokinetics of cotinine in rats: a potential therapeutic agent for disorders of cognitive function.

    Science.gov (United States)

    Li, Pei; Beck, Wayne D; Callahan, Patrick M; Terry, Alvin V; Bartlett, Michael G

    2015-06-01

    Attention has been paid to cotinine (COT), one of the major metabolites of nicotine (NIC), for its pro-cognitive effects and potential therapeutic activities against Alzheimer's disease (AD) and other types of cognitive impairment. In order to facilitate pharmacological and toxicological studies on COT for its pro-cognitive activities, we conducted a pharmacokinetic (PK) study of COT in rats, providing important oral and intravenously (iv) PK information. In this study, plasma samples were obtained up to 48 h after COT was dosed to rats orally and iv at a dose of 3mg/kg. Plasma samples were prepared and analyzed using a sensitive liquid chromatography tandem mass spectrometry (LC-MS/MS) bioanalytical method, providing concentration profiles of COT and metabolites after oral and iv administrations. The data were fitted into a one-compartment model and a two-compartment model for the oral and iv groups, respectively, providing important PK information for COT including PK profiles, half-life, clearance and bioavailability. The results suggested fast absorption, slow elimination and high bioavailability of COT in rats. Several important facts about the PK properties in rats suggested COT could be a potential pro-cognitive agent. Information about the pharmacokinetics of COT in rats revealed in this study is of great importance for the future studies on COT or potential COT analogs as agents for improving cognition. Copyright © 2014 Institute of Pharmacology, Polish Academy of Sciences. Published by Elsevier Urban & Partner Sp. z o.o. All rights reserved.

  8. Dendrimer Advances for the Central Nervous System Delivery of Therapeutics

    Science.gov (United States)

    2013-01-01

    The effectiveness of noninvasive treatment for central nervous system (CNS) diseases is generally limited by the poor access of therapeutic agents into the CNS. Most CNS drugs cannot permeate into the brain parenchyma because of the blood-brain barrier (BBB), and overcoming this has become one of the most significant challenges in the development of CNS therapeutics. Rapid advances in nanotechnology have provided promising solutions to this challenge. This review discusses the latest applications of dendrimers in the treatment of CNS diseases with an emphasis on brain tumors. Dendrimer-mediated drug delivery, imaging, and diagnosis are also reviewed. The toxicity, biodistribution, and transport mechanisms in dendrimer-mediated delivery of CNS therapeutic agents bypassing or crossing the BBB are also discussed. Future directions and major challenges of dendrimer-mediated delivery of CNS therapeutic agents are included. PMID:24274162

  9. Recent trends in the transdermal delivery of therapeutic agents used for the management of neurodegenerative diseases.

    Science.gov (United States)

    Ita, Kevin

    2017-06-01

    With the increasing proportion of the global geriatric population, it becomes obvious that neurodegenerative diseases will become more widespread. From an epidemiological standpoint, it is necessary to develop new therapeutic agents for the management of Alzheimer's disease, Parkinson's disease, multiple sclerosis and other neurodegenerative disorders. An important approach in this regard involves the use of the transdermal route. With transdermal drug delivery systems (TDDS), it is possible to modulate the pharmacokinetic profiles of these medications and improve patient compliance. Transdermal drug delivery has also been shown to be useful for drugs with short half-life and low or unpredictable bioavailability. In this review, several transdermal drug delivery enhancement technologies are being discussed in relation to the delivery of medications used for the management of neurodegenerative disorders.

  10. Therapeutics of Ebola hemorrhagic fever: whole-genome transcriptional analysis of successful disease mitigation.

    Science.gov (United States)

    Yen, Judy Y; Garamszegi, Sara; Geisbert, Joan B; Rubins, Kathleen H; Geisbert, Thomas W; Honko, Anna; Xia, Yu; Connor, John H; Hensley, Lisa E

    2011-11-01

    The mechanisms of Ebola (EBOV) pathogenesis are only partially understood, but the dysregulation of normal host immune responses (including destruction of lymphocytes, increases in circulating cytokine levels, and development of coagulation abnormalities) is thought to play a major role. Accumulating evidence suggests that much of the observed pathology is not the direct result of virus-induced structural damage but rather is due to the release of soluble immune mediators from EBOV-infected cells. It is therefore essential to understand how the candidate therapeutic may be interrupting the disease process and/or targeting the infectious agent. To identify genetic signatures that are correlates of protection, we used a DNA microarray-based approach to compare the host genome-wide responses of EBOV-infected nonhuman primates (NHPs) responding to candidate therapeutics. We observed that, although the overall circulating immune response was similar in the presence and absence of coagulation inhibitors, surviving NHPs clustered together. Noticeable differences in coagulation-associated genes appeared to correlate with survival, which revealed a subset of distinctly differentially expressed genes, including chemokine ligand 8 (CCL8/MCP-2), that may provide possible targets for early-stage diagnostics or future therapeutics. These analyses will assist us in understanding the pathogenic mechanisms of EBOV infection and in identifying improved therapeutic strategies.

  11. Strategy to prime the host and cells to augment therapeutic efficacy of progenitor cells for patients with myocardial infarction

    Directory of Open Access Journals (Sweden)

    Jeehoon Kang

    2016-11-01

    Full Text Available Cell therapy in myocardial infarction (MI is an innovative strategy that is regarded as a rescue therapy to repair the damaged myocardium and to promote neovascularization for the ischemic border zone. Among several stem cell sources for this purpose, autologous progenitors from bone marrow or peripheral blood would be the most feasible and safest cell-source. Despite the theoretical benefit of cell therapy, this method is not widely adopted in the actual clinical practice due to its low therapeutic efficacy. Various methods have been used to augment the efficacy of cell therapy in MI, such as using different source of progenitors, genetic manipulation of cells, or priming of the cells or hosts (patients with agents. Among these methods, the strategy to augment the therapeutic efficacy of the autologous peripheral blood mononuclear cells by priming agents may be the most feasible and the safest method that can be applied directly to the clinic. In this review, we will discuss the current status and future directions of priming peripheral blood mononuclear cells or patients, as for cell therapy of MI.

  12. Biomedical and therapeutic applications of biosurfactants

    OpenAIRE

    Rodrigues, L. R.; Teixeira, J. A.

    2010-01-01

    During the last years, several applications of biosurfactants with medical purposes have been reported. Biosurfactants are considered relevant molecules for applications in combating many diseases and as therapeutic agents due to their antibacterial, antifungal and antiviral activities. Furthermore, their role as anti-adhesive agents against several pathogens illustrate their utility as suitable anti-adhesive coating agents for medical insertional materials leading to a reduction of a large n...

  13. Therapeutic hypothermia for acute stroke

    DEFF Research Database (Denmark)

    Olsen, Tom Skyhøj; Weber, Uno Jakob; Kammersgaard, Lars Peter

    2003-01-01

    Experimental evidence and clinical experience show that hypothermia protects the brain from damage during ischaemia. There is a growing hope that the prevention of fever in stroke will improve outcome and that hypothermia may be a therapeutic option for the treatment of stroke. Body temperature...... obvious therapeutic potential, hypothermia as a form of neuroprotection for stroke has been investigated in only a few very small studies. Therapeutic hypothermia is feasible in acute stroke but owing to serious side-effects--such as hypotension, cardiac arrhythmia, and pneumonia--it is still thought...

  14. The nitric oxide prodrug JS-K and its structural analogues as cancer therapeutic agents.

    Science.gov (United States)

    Maciag, Anna E; Saavedra, Joseph E; Chakrapani, Harinath

    2009-09-01

    Nitric oxide (NO) prodrugs of the diazeniumdiolate class are routinely used as reliable sources of nitric oxide in chemical and biological laboratory settings. O(2)-(2,4-dinitrophenyl) diazeniumdiolates, which are derivatized forms of ionic diazeniumdiolates, have been found to show potent anti-proliferative activity in a variety of cancer cells, presumably through the effects of NO. One important member of this class of diazeniumdiolates, O(2)-(2,4-dinitrophenyl) 1-[(4-ethoxycarbonyl)piperazin-1-yl]diazen-1-ium-1,2-diolate (JS-K), has shown promise as a novel cancer therapeutic agent in a number of animal models. This review describes the developments in chemical and biochemical characterization and structure-activity relationship of JS-K and its analogues. In addition, some molecular mechanistic insights into the observed anti-proliferative activity of JS-K are discussed. Finally, a structural motif is presented for O(2)-(aryl) diazeniumdiolate nitric oxide prodrugs that show potency comparable with that of JS-K.

  15. Melatonin Role in Ameliorating Radiation-induced Skin Damage: From Theory to Practice (A Review of Literature

    Directory of Open Access Journals (Sweden)

    Abbaszadeh A.

    2017-06-01

    Full Text Available Normal skin is composed of epidermis and dermis. Skin is susceptible to radiation damage because it is a continuously renewing organ containing rapidly proliferating mature cells. Radiation burn is a damage to the skin or other biological tissues caused by exposure to radiofrequency energy or ionizing radiation. Acute skin reaction is the most frequently occurring side effect of radiation therapy. Generally, any chemical/ biological agent given before or at the time of irradiation to prevent or ameliorate damage to normal tissues is called a radioprotector. Melatonin is a highly lipophilic substance that easily penetrates organic membranes and therefore is able to protect important intracellular structures including mitochondria and DNA against oxidative damage directly at the sites where such a kind of damage would occur. Melatonin leads to an increase in the molecular level of some important antioxidative enzymes such as superoxide, dismotase and glutation-peroxidase, and also a reduction in synthetic activity of nitric oxide. There is a large body of evidence which proves the efficacy of Melatonin in ameliorating UV and X ray-induced skin damage. We propose that, in the future, Melatonin would improve the therapeutic ratio in radiation oncology and ameliorate skin damage more effectively when administered in optimal and non-toxic doses

  16. MCM-41 mesoporous silica nanoparticles functionalized with aptamer and radiolabelled with 90Y and 159Gd as a potential therapeutic agent against colorectal cancer

    International Nuclear Information System (INIS)

    Ferreira, Carolina de Aguiar

    2014-01-01

    Colorectal cancer (CRC) is a malignancy that affects large intestine and rectum, and it is the most common malignancy of the gastrointestinal tract, the third most commonly diagnosed type of cancer in the world and the second leading cause of cancer-related death in the United States. Nowadays, available therapeutic procedures for this type of cancer are limited and ineffective. Conventional radiotherapy is not an often used approach in the treatment of CRC due to the fact that peristaltic movements hamper the targeting of ionizing radiation and this type of treatment is used as adjuvant and palliative to control symptoms. Therefore, surgical intervention is the primary therapeutic choice against this disease. Researches based on the combination of radioisotopes and nanostructured carriers systems have demonstrated significant results in improving the selectivity action as well as reducing the radiation dose into healthy tissues. MCM-41 mesoporous silica nanoparticles have unique characteristics such as high surface area and well-defined pore diameters making these nanoparticles an ideal candidate of therapeutic agent carrier. Thus, the objective of this work is to synthesize and characterize MCM-41 mesoporous silica nanoparticles conjugated with yttrium-90 and gadolinium-159 and evaluate this system as a potential therapeutic agent. The nanoparticles were synthesized via sol-gel method. The sample was characterized using FTIR, SAXS, PCS, Zeta Potential analysis, Thermal analysis, CHN elemental analysis, nitrogen adsorption, scanning and transmission electron microscopy. The ability to incorporate Y +3 and Gd +3 ion was determined in vitro using different ratios (1:1, 1:3, 1:5 v/v) of YCL 3 and Gd 2 O 3 and silica nanoparticles dispersed in saline, pH 7.4. The non-incorporated Y +3 and Gd +3 ions were removed by ultracentrifugation procedure and the concentration of ions in the supernatant was determined by ICP-AES. Cell viability was assessed by colorimetric MTT

  17. Topical efficacy of dimercapto-chelating agents against lewisite-induced skin lesions in SKH-1 hairless mice

    Energy Technology Data Exchange (ETDEWEB)

    Mouret, Stéphane, E-mail: stephane.mouret@irba.fr [Département de Toxicologie et Risques Chimiques, Institut de Recherche Biomédicale des Armées, Centre de Recherches du Service de Santé des Armées, 24 avenue Maquis du Grésivaudan, 38700 La Tronche (France); Wartelle, Julien; Emorine, Sandy; Bertoni, Marine; Nguon, Nina; Cléry-Barraud, Cécile [Département de Toxicologie et Risques Chimiques, Institut de Recherche Biomédicale des Armées, Centre de Recherches du Service de Santé des Armées, 24 avenue Maquis du Grésivaudan, 38700 La Tronche (France); Dorandeu, Frédéric [Département de Toxicologie et Risques Chimiques, Institut de Recherche Biomédicale des Armées, Centre de Recherches du Service de Santé des Armées, 24 avenue Maquis du Grésivaudan, 38700 La Tronche (France); Ecole du Val-de-Grâce, 1 place Alphonse Laveran, Paris (France); Boudry, Isabelle [Département de Toxicologie et Risques Chimiques, Institut de Recherche Biomédicale des Armées, Centre de Recherches du Service de Santé des Armées, 24 avenue Maquis du Grésivaudan, 38700 La Tronche (France)

    2013-10-15

    Lewisite is a potent chemical warfare arsenical vesicant that can cause severe skin lesions. Today, lewisite exposure remains possible during demilitarization of old ammunitions and as a result of deliberate use. Although its cutaneous toxicity is not fully elucidated, a specific antidote exists, the British anti-lewisite (BAL, dimercaprol) but it is not without untoward effects. Analogs of BAL, less toxic, have been developed such as meso-2,3-dimercaptosuccinic acid (DMSA) and have been employed for the treatment of heavy metal poisoning. However, efficacy of DMSA against lewisite-induced skin lesions remains to be determined in comparison with BAL. We have thus evaluated in this study the therapeutic efficacy of BAL and DMSA in two administration modes against skin lesions induced by lewisite vapor on SKH-1 hairless mice. Our data demonstrate a strong protective efficacy of topical application of dimercapto-chelating agents in contrast to a subcutaneous administration 1 h after lewisite exposure, with attenuation of wound size, necrosis and impairment of skin barrier function. The histological evaluation also confirms the efficacy of topical application by showing that treatments were effective in reversing lewisite-induced neutrophil infiltration. This protective effect was associated with an epidermal hyperplasia. However, for all the parameters studied, BAL was more effective than DMSA in reducing lewisite-induced skin injury. Together, these findings support the use of a topical form of dimercaprol-chelating agent against lewisite-induced skin lesion within the first hour after exposure to increase the therapeutic management and that BAL, despite its side-effects, should not be abandoned. - Highlights: • Topically applied dimercapto-chelating agents reduce lewisite-induced skin damage. • One topical application of BAL or DMSA is sufficient to reverse lewisite effects. • Topical BAL is more effective than DMSA to counteract lewisite-induced skin damage.

  18. Therapeutic improvement of colonic anastomotic healing under complicated conditions

    DEFF Research Database (Denmark)

    Nerstrøm, Malene; Krarup, Peter-Martin; Jørgensen, Lars Nannestad

    2016-01-01

    AIM: To identify therapeutic agents for the prophylaxis of gastrointestinal anastomotic leakage (AL) under complicated conditions. METHODS: The PubMed and EMBASE databases were searched for English articles published between January 1975 and September 2014. Studies with the primary purpose of imp...... controls in experimental chemotherapeutic models. CONCLUSION: This systematic review identified potential therapeutic agents, but more studies are needed before concluding that any of these are useful for AL prophylaxis....

  19. Prospects for therapeutic mitochondrial transplantation.

    Science.gov (United States)

    Gollihue, Jenna L; Rabchevsky, Alexander G

    2017-07-01

    Mitochondrial dysfunction has been implicated in a multitude of diseases and pathological conditions- the organelles that are essential for life can also be major players in contributing to cell death and disease. Because mitochondria are so well established in our existence, being present in all cell types except for red blood cells and having the responsibility of providing most of our energy needs for survival, then dysfunctional mitochondria can elicit devastating cellular pathologies that can be widespread across the entire organism. As such, the field of "mitochondrial medicine" is emerging in which disease states are being targeted therapeutically at the level of the mitochondrion, including specific antioxidants, bioenergetic substrate additions, and membrane uncoupling agents. New and compelling research investigating novel techniques for mitochondrial transplantation to replace damaged or dysfunctional mitochondria with exogenous healthy mitochondria has shown promising results, including tissue sparing accompanied by increased energy production and decreased oxidative damage. Various experimental techniques have been attempted and each has been challenged to accomplish successful transplantation. The purpose of this review is to present the history of mitochondrial transplantation, the different techniques used for both in vitro and in vivo delivery, along with caveats and pitfalls that have been discovered along the way. Results from such pioneering studies are promising and could be the next big wave of "mitochondrial medicine" once technical hurdles are overcome. Copyright © 2017 Elsevier B.V. and Mitochondria Research Society. All rights reserved.

  20. [Alkylating agents].

    Science.gov (United States)

    Pourquier, Philippe

    2011-11-01

    With the approval of mechlorethamine by the FDA in 1949 for the treatment of hematologic malignancies, alkylating agents are the oldest class of anticancer agents. Even though their clinical use is far beyond the use of new targeted therapies, they still occupy a major place in specific indications and sometimes represent the unique option for the treatment of refractory diseases. Here, we are reviewing the major classes of alkylating agents and their mechanism of action, with a particular emphasis for the new generations of alkylating agents. As for most of the chemotherapeutic agents used in the clinic, these compounds are derived from natural sources. With a complex but original mechanism of action, they represent new interesting alternatives for the clinicians, especially for tumors that are resistant to conventional DNA damaging agents. We also briefly describe the different strategies that have been or are currently developed to potentiate the use of classical alkylating agents, especially the inhibition of pathways that are involved in the repair of DNA lesions induced by these agents. In this line, the development of PARP inhibitors is a striking example of the recent regain of interest towards the "old" alkylating agents.

  1. Identification of novel human damage response proteins targeted through yeast orthology.

    Directory of Open Access Journals (Sweden)

    J Peter Svensson

    Full Text Available Studies in Saccharomyces cerevisiae show that many proteins influence cellular survival upon exposure to DNA damaging agents. We hypothesized that human orthologs of these S. cerevisiae proteins would also be required for cellular survival after treatment with DNA damaging agents. For this purpose, human homologs of S. cerevisiae proteins were identified and mapped onto the human protein-protein interaction network. The resulting human network was highly modular and a series of selection rules were implemented to identify 45 candidates for human toxicity-modulating proteins. The corresponding transcripts were targeted by RNA interference in human cells. The cell lines with depleted target expression were challenged with three DNA damaging agents: the alkylating agents MMS and 4-NQO, and the oxidizing agent t-BuOOH. A comparison of the survival revealed that the majority (74% of proteins conferred either sensitivity or resistance. The identified human toxicity-modulating proteins represent a variety of biological functions: autophagy, chromatin modifications, RNA and protein metabolism, and telomere maintenance. Further studies revealed that MMS-induced autophagy increase the survival of cells treated with DNA damaging agents. In summary, we show that damage recovery proteins in humans can be identified through homology to S. cerevisiae and that many of the same pathways are represented among the toxicity modulators.

  2. Potential therapeutic effects of branched-chain amino acids supplementation on resistance exercise-based muscle damage in humans

    Directory of Open Access Journals (Sweden)

    da Luz Claudia R

    2011-12-01

    Full Text Available Abstract Branched-chain amino acids (BCAA supplementation has been considered an interesting nutritional strategy to improve skeletal muscle protein turnover in several conditions. In this context, there is evidence that resistance exercise (RE-derived biochemical markers of muscle soreness (creatine kinase (CK, aldolase, myoglobin, soreness, and functional strength may be modulated by BCAA supplementation in order to favor of muscle adaptation. However, few studies have investigated such effects in well-controlled conditions in humans. Therefore, the aim of this short report is to describe the potential therapeutic effects of BCAA supplementation on RE-based muscle damage in humans. The main point is that BCAA supplementation may decrease some biochemical markers related with muscle soreness but this does not necessarily reflect on muscle functionality.

  3. Radiation-induced normal tissue damage: implications for radiotherapy

    International Nuclear Information System (INIS)

    Prasanna, Pataje G.

    2014-01-01

    Radiotherapy is an important treatment modality for many malignancies, either alone or as a part of combined modality treatment. However, despite technological advances in physical treatment delivery, patients suffer adverse effects from radiation therapy due to normal tissue damage. These side effects may be acute, occurring during or within weeks after therapy, or intermediate to late, occurring months to years after therapy. Minimizing normal tissue damage from radiotherapy will allow enhancement of tumor killing and improve tumor control and patients quality of life. Understanding mechanisms through which radiation toxicity develops in normal tissue will facilitate the development of next generation radiation effect modulators. Translation of these agents to the clinic will also require an understanding of the impact of these protectors and mitigators on tumor radiation response. In addition, normal tissues vary in radiobiologically important ways, including organ sensitivity to radiation, cellular turnover rate, and differences in mechanisms of injury manifestation and damage response. Therefore, successful development of radiation modulators may require multiple approaches to address organ/site-specific needs. These may include treatments that modify cellular damage and death processes, inflammation, alteration of normal flora, wound healing, tissue regeneration and others, specifically to counter cancer site-specific adverse effects. Further, an understanding of mechanisms of normal tissue damage will allow development of predictive biomarkers; however harmonization of such assays is critical. This is a necessary step towards patient-specific treatment customization. Examples of important adverse effects of radiotherapy either alone or in conjunction with chemotherapy, and important limitations in the current approaches of using radioprotectors for improving therapeutic outcome will be highlighted. (author)

  4. Evaluation of 188Re-labeled PEGylated nanoliposome as a radionuclide therapeutic agent in an orthotopic glioma-bearing rat model

    Directory of Open Access Journals (Sweden)

    Huang FYJ

    2015-01-01

    Full Text Available Feng-Yun J Huang,1 Te-Wei Lee,2 Chih-Hsien Chang,2 Liang-Cheng Chen,2 Wei-Hsin Hsu,2 Chien-Wen Chang,1 Jem-Mau Lo1 1Department of Biomedical Engineering and Environmental Sciences, National Tsing Hua University, Hsinchu, Taiwan; 2Institute of Nuclear Energy Research, Longtan, Taiwan Purpose: In this study, the 188Re-labeled PEGylated nanoliposome (188Re-liposome was prepared and evaluated as a therapeutic agent for glioma.Materials and methods: The reporter cell line, F98luc was prepared via Lentivector expression kit system and used to set up the orthotopic glioma-bearing rat model for non-invasive bioluminescent imaging. The maximum tolerated dose applicable in Fischer344 rats was explored via body weight monitoring of the rats after single intravenous injection of 188Re-liposome with varying dosages before the treatment study. The OLINDA/EXM 1.1 software was utilized for estimating the radiation dosimetry. To assess the therapeutic efficacy, tumor-bearing rats were intravenously administered 188Re-liposome or normal saline followed by monitoring of the tumor growth and animal survival time. In addition, the histopathological examinations of tumors were conducted on the 188Re-liposome-treated rats.Results: By using bioluminescent imaging, the well-established reporter cell line (F98luc showed a high relationship between cell number and its bioluminescent intensity (R2=0.99 in vitro; furthermore, it could also provide clear tumor imaging for monitoring tumor growth in vivo. The maximum tolerated dose of 188Re-liposome in Fischer344 rats was estimated to be 333 MBq. According to the dosimetry results, higher equivalent doses were observed in spleen and kidneys while very less were in normal brain, red marrow, and thyroid. For therapeutic efficacy study, the progression of tumor growth in terms of tumor volume and/or tumor weight was significantly slower for the 188Re-liposome-treated group than the control group (P<0.05. As a result, the

  5. Logical network of genotoxic stress-induced NF-kappaB signal transduction predicts putative target structures for therapeutic intervention strategies

    Directory of Open Access Journals (Sweden)

    Rainer Poltz

    2009-12-01

    Full Text Available Rainer Poltz1, Raimo Franke1,#, Katrin Schweitzer1, Steffen Klamt2, Ernst-Dieter Gilles2, Michael Naumann11Institute of Experimental Internal Medicine, Otto von Guericke University, Magdeburg, Germany; 2Max Planck Institute for Dynamics of Complex Technical Systems, Magdeburg, Germany; #Present address: Department of Chemical Biology, Helmholtz Centre for Infection Research, Braunschweig, GermanyAbstract: Genotoxic stress is induced by a broad range of DNA-damaging agents and could lead to a variety of human diseases including cancer. DNA damage is also therapeutically induced for cancer treatment with the aim to eliminate tumor cells. However, the effectiveness of radio- and chemotherapy is strongly hampered by tumor cell resistance. A major reason for radio- and chemotherapeutic resistances is the simultaneous activation of cell survival pathways resulting in the activation of the transcription factor nuclear factor-kappa B (NF-κB. Here, we present a Boolean network model of the NF-κB signal transduction induced by genotoxic stress in epithelial cells. For the representation and analysis of the model, we used the formalism of logical interaction hypergraphs. Model reconstruction was based on a careful meta-analysis of published data. By calculating minimal intervention sets, we identified p53-induced protein with a death domain (PIDD, receptor-interacting protein 1 (RIP1, and protein inhibitor of activated STAT y (PIASy as putative therapeutic targets to abrogate NF-κB activation resulting in apoptosis. Targeting these structures therapeutically may potentiate the effectiveness of radio- and chemotherapy. Thus, the presented model allows a better understanding of the signal transduction in tumor cells and provides candidates as new therapeutic target structures.Keywords: apoptosis, Boolean network, cancer therapy, DNA-damage response, NF-κB

  6. Molecular cloning and characterization of an Erwinia carotovora subsp. carotovora pectin lyase gene that responds to DNA-damaging agents.

    OpenAIRE

    McEvoy, J L; Murata, H; Chatterjee, A K

    1990-01-01

    recA-mediated production of pectin lyase (PNL) and the bacteriocin carotovoricin occurs in Erwinia carotovora subsp. carotovora 71 when this organism is subjected to agents that damage or inhibit the synthesis of DNA. The structural gene pnlA was isolated from a strain 71 cosmid gene library following mobilization of the cosmids into a moderate PNL producer, strain 193. The cosmid complemented pnl::Tn5 but not ctv::Tn5 mutations. A constitutive level of PNL activity was detected in RecA+ and ...

  7. New and exploratory therapeutic agents for asthma

    National Research Council Canada - National Science Library

    Yeadon, Michael; Diamant, Zuzana

    2000-01-01

    ... been accomplished. It is well recognized that new drugs are essentially the result of basic and applied research. Early in this century, the advent of a chemical approach to medicine led to many extraordinary developments. The past few decades have been characterized by a search to understand the mechanisms of disease- a quest spurred by the recognition that if pathogenic processes were known, new therapeutic opportunities would ensue. The validity of this concept is beautifully illustrated in the case of asthma. Here is a d...

  8. Deoxypodophyllotoxin: a promising therapeutic agent from herbal medicine.

    Science.gov (United States)

    Khaled, Meyada; Jiang, Zhen-Zhou; Zhang, Lu-Yong

    2013-08-26

    Recently, biologically active compounds isolated from plants used in herbal medicine have been the center of interest. Deoxypodophyllotoxin (DPT), structurally closely related to the lignan podophyllotoxin, is a potent antitumor and anti-inflammatory agent. However, DPT has not been used clinically yet. Also, DPT from natural sources seems to be unavailable. Hence, it is important to establish alternative resources for the production of such lignan; especially that it is used as a precursor for the semi-synthesis of the cytostatic drugs etoposide phosphate and teniposide. The update paper provides an overview of DPT as an effective anticancer natural compound and a leader for cytotoxic drugs synthesis and development in order to highlight the gaps in our knowledge and explore future research needs. The present review covers the literature available from 1877 to 2012. The information was collected via electronic search using Chinese papers and the major scientific databases including PubMed, Sciencedirect, Web of Science and Google Scholar using the keywords. All abstracts and full-text articles reporting database on the history and current status of DPT were gathered and analyzed. Plants containing DPT have played an important role in traditional medicine. In light of the in vitro pharmacological investigations, DPT is a high valuable medicinal agent that has anti-tumor, anti-proliferative, anti-inflammatory and anti-allergic properties. Further, DPT is an important precursor for the cytotoxic aryltetralin lignan, podophyllotoxin, which is used to obtain semisynthetic derivatives like etoposide and teniposide used in cancer therapy. However, most studies have focused on the in vitro data. Therefore, DPT has not been used clinically yet. DPT has emerged as a potent chemical agent from herbal medicine. Therefore, in vivo studies are needed to carry out clinical trials in humans and enable the development of new anti-cancer agents. In addition, DPT from commercial

  9. Radioprotection in E. coli by an agent from M. radiodurans

    Energy Technology Data Exchange (ETDEWEB)

    Goldstein, L S; Gersten, D M; Bruce, A K [State Univ. of New York, Buffalo (USA). Dept. of Biology

    1978-10-01

    An agent extracted from the radioresistant bacterium M. radiodurans was found to protect several strains of E. coli from X-radiation. Optimal radioprotection was observed when the repair-proficient B/r strain was irradiated in the presence of the agent under hypoxic conditions. It is proposed that this agent acts to modify damage incurred in the presence of reduced oxygen concentrations so that this damage might be subsequently repaired.

  10. DNA damage-inducible transcripts in mammalian cells

    International Nuclear Information System (INIS)

    Fornace, A.J. Jr.; Alamo, I. Jr.; Hollander, M.C.

    1988-01-01

    Hybridization subtraction at low ratios of RNA to cDNA was used to enrich for the cDNA of transcripts increased in Chinese hamster cells after UV irradiation. Forty-nine different cDNA clones were isolated. Most coded for nonabundant transcripts rapidly induced 2- to 10-fold after UV irradiation. Only 2 of the 20 cDNA clones sequenced matched known sequences (metallothionein I and II). The predicted amino acid sequence of one cDNA had two localized areas of homology with the rat helix-destabilizing protein. These areas of homology were at the two DNA-binding sites of this nucleic acid single-strand-binding protein. The induced transcripts were separated into two general classes. Class I transcripts were induced by UV radiation and not by the alkylating agent methyl methanesulfonate. Class II transcripts were induced by UV radiation and by methyl methanesulfonate. Many class II transcripts were induced also by H2O2 and various alkylating agents but not by heat shock, phorbol 12-tetradecanoate 13-acetate, or DNA-damaging agents which do not produce high levels of base damage. Since many of the cDNA clones coded for transcripts which were induced rapidly and only by certain types of DNA-damaging agents, their induction is likely a specific response to such damage rather than a general response to cell injury

  11. A high-affinity, dimeric inhibitor of PSD-95 bivalently interacts with PDZ1-2 and protects against ischemic brain damage

    DEFF Research Database (Denmark)

    Bach, Anders*; Clausen, Bettina H; Møller, Magda

    2012-01-01

    Inhibition of the ternary protein complex of the synaptic scaffolding protein postsynaptic density protein-95 (PSD-95), neuronal nitric oxide synthase (nNOS), and the N-methyl-d-aspartate (NMDA) receptor is a potential strategy for treating ischemic brain damage, but high-affinity inhibitors are ...... of Tat-N-dimer (3 nmol/g) to mice subjected to focal cerebral ischemia reduces infarct volume with 40% and restores motor functions. Thus, Tat-N-dimer is a highly efficacious neuroprotective agent with therapeutic potential in stroke....

  12. Moderate variations in CDC25B protein levels modulate the response to DNA damaging agents

    International Nuclear Information System (INIS)

    Aressy, B.; Bugler, B.; Valette, A.; Ducommun, B.; Biard, D.

    2008-01-01

    CDC25B, one of the three members of the CDC25 dual-specificity phosphatase family, plays a critical role in the control of the cell cycle and in the checkpoint response to DNA damage. CDC25B is responsible for the initial dephosphorylation and activation of the cyclin-dependent kinases, thus initiating the train of events leading to entry into mitosis. The critical role played by CDC25B is illustrated by the fact that it is specifically required for checkpoint recovery and that unscheduled accumulation of CDC25B is responsible for illegitimate entry into mitosis. Here, we report that in p53 colon carcinoma cells, a moderate increase in the CDC25B level is sufficient to impair the DNA damage checkpoint, to increase spontaneous mutagenesis, and to sensitize cells to ionising radiation and genotoxic agents. Using a tumour cell spheroid assay as an alternative to animal studies, we demonstrate that the level of CDC25B expression modulates growth inhibition and apoptotic death. Since CDC25B overexpression has been observed in a significant number of human cancers, including colon carcinoma, and is often associated with high grade tumours and poor prognosis, our work suggests that the expression level of CDC25B might be a potential key parameter of the cellular response to cancer therapy. (authors)

  13. DNA Damage Induced by Alkylating Agents and Repair Pathways

    OpenAIRE

    Natsuko Kondo; Akihisa Takahashi; Koji Ono; Takeo Ohnishi

    2010-01-01

    The cytotoxic effects of alkylating agents are strongly attenuated by cellular DNA repair processes, necessitating a clear understanding of the repair mechanisms. Simple methylating agents form adducts at N- and O-atoms. N-methylations are removed by base excision repair, AlkB homologues, or nucleotide excision repair (NER). O 6-methylguanine (MeG), which can eventually become cytotoxic and mutagenic, is repaired by O 6-methylguanine-DNA methyltransferase, and O 6MeG:T mispairs are recognized...

  14. Bacterial agents and sensitivity pattern of neonatal conjuctivitis in ...

    African Journals Online (AJOL)

    Introduction: In Africa alone, between 1000 – 4000 children are blinded annually by conjunctivitis. In view of the changing aetiological agents documented in other parts of the world and evolving resistance of infective agents to therapeutic agents, the present study was designed to define the bacterial agents, their antibiotic ...

  15. Therapeutic response assessment of percutaneous radiofrequency ablation for hepatocellular carcinoma: Utility of contrast-enhanced agent detection imaging

    International Nuclear Information System (INIS)

    Kim, Chan Kyo; Choi, Dongil; Lim, Hyo K.; Kim, Seung Hoon; Lee, Won Jae; Kim, Min Ju; Lee, Ji Yeon; Jeon, Yong Hwan; Lee, Jongmee; Lee, Soon Jin; Lim, Jae Hoon

    2005-01-01

    Purpose: To assess the utility of contrast-enhanced agent detection imaging (ADI) in the assessment of the therapeutic response to percutaneous radiofrequency (RF) ablation in patients with hepatocellular carcinoma (HCC). Materials and methods: Ninety patients with a total of 97 nodular HCCs (mean, 2.1 ± 1.3 cm; range, 1.0-5.0 cm) treated with percutaneous RF ablation under the ultrasound guidance were evaluated with contrast-enhanced ADI after receiving an intravenous bolus injection of a microbubble contrast agent (SH U 508A). We obtained serial contrast-enhanced ADI images during the time period from 15 to 90 s after the initiation of the bolus contrast injection. All of the patients underwent a follow-up four-phase helical CT at 1 month after RF ablation, which was then repeated at 2-4 month intervals during a period of at least 12 months. The results of the contrast-enhanced ADI were compared with those of the follow-up CT in terms of the presence or absence of residual unablated tumor and local tumor progression in the treated lesions. Results: On contrast-enhanced ADI, technical success was obtained in 94 (97%) of the 97 HCCs, while residual unablated tumors were found in three HCCs (3%). Two of the three tumors that were suspicious (was not proven) for incomplete ablation were subjected to additional RF ablation. The remaining one enhancing lesion that was suspicious of a residual tumor on contrast-enhanced ADI was revealed to be reactive hyperemia at the 1-month follow-up CT. Therefore; the diagnostic concordance between the contrast-enhanced ADI and 1-month follow-up CT was 99%. Of the 94 ablated HCCs without residual tumors on both the contrast-enhanced ADI and 1-month follow-up CT after the initial RF ablation, five (5%) had CT findings of local tumor progression at a subsequent follow-up CT. Conclusion: Despite its limitations in predicting local tumor progression in the treated tumors, contrast-enhanced ADI is potentially useful for evaluating the

  16. DNA Damage, Mutagenesis and Cancer

    Directory of Open Access Journals (Sweden)

    Ashis K. Basu

    2018-03-01

    Full Text Available A large number of chemicals and several physical agents, such as UV light and γ-radiation, have been associated with the etiology of human cancer. Generation of DNA damage (also known as DNA adducts or lesions induced by these agents is an important first step in the process of carcinogenesis. Evolutionary processes gave rise to DNA repair tools that are efficient in repairing damaged DNA; yet replication of damaged DNA may take place prior to repair, particularly when they are induced at a high frequency. Damaged DNA replication may lead to gene mutations, which in turn may give rise to altered proteins. Mutations in an oncogene, a tumor-suppressor gene, or a gene that controls the cell cycle can generate a clonal cell population with a distinct advantage in proliferation. Many such events, broadly divided into the stages of initiation, promotion, and progression, which may occur over a long period of time and transpire in the context of chronic exposure to carcinogens, can lead to the induction of human cancer. This is exemplified in the long-term use of tobacco being responsible for an increased risk of lung cancer. This mini-review attempts to summarize this wide area that centers on DNA damage as it relates to the development of human cancer.

  17. Aag DNA glycosylase promotes alkylation-induced tissue damage mediated by Parp1.

    Science.gov (United States)

    Calvo, Jennifer A; Moroski-Erkul, Catherine A; Lake, Annabelle; Eichinger, Lindsey W; Shah, Dharini; Jhun, Iny; Limsirichai, Prajit; Bronson, Roderick T; Christiani, David C; Meira, Lisiane B; Samson, Leona D

    2013-04-01

    Alkylating agents comprise a major class of front-line cancer chemotherapeutic compounds, and while these agents effectively kill tumor cells, they also damage healthy tissues. Although base excision repair (BER) is essential in repairing DNA alkylation damage, under certain conditions, initiation of BER can be detrimental. Here we illustrate that the alkyladenine DNA glycosylase (AAG) mediates alkylation-induced tissue damage and whole-animal lethality following exposure to alkylating agents. Aag-dependent tissue damage, as observed in cerebellar granule cells, splenocytes, thymocytes, bone marrow cells, pancreatic β-cells, and retinal photoreceptor cells, was detected in wild-type mice, exacerbated in Aag transgenic mice, and completely suppressed in Aag⁻/⁻ mice. Additional genetic experiments dissected the effects of modulating both BER and Parp1 on alkylation sensitivity in mice and determined that Aag acts upstream of Parp1 in alkylation-induced tissue damage; in fact, cytotoxicity in WT and Aag transgenic mice was abrogated in the absence of Parp1. These results provide in vivo evidence that Aag-initiated BER may play a critical role in determining the side-effects of alkylating agent chemotherapies and that Parp1 plays a crucial role in Aag-mediated tissue damage.

  18. Aag DNA glycosylase promotes alkylation-induced tissue damage mediated by Parp1.

    Directory of Open Access Journals (Sweden)

    Jennifer A Calvo

    2013-04-01

    Full Text Available Alkylating agents comprise a major class of front-line cancer chemotherapeutic compounds, and while these agents effectively kill tumor cells, they also damage healthy tissues. Although base excision repair (BER is essential in repairing DNA alkylation damage, under certain conditions, initiation of BER can be detrimental. Here we illustrate that the alkyladenine DNA glycosylase (AAG mediates alkylation-induced tissue damage and whole-animal lethality following exposure to alkylating agents. Aag-dependent tissue damage, as observed in cerebellar granule cells, splenocytes, thymocytes, bone marrow cells, pancreatic β-cells, and retinal photoreceptor cells, was detected in wild-type mice, exacerbated in Aag transgenic mice, and completely suppressed in Aag⁻/⁻ mice. Additional genetic experiments dissected the effects of modulating both BER and Parp1 on alkylation sensitivity in mice and determined that Aag acts upstream of Parp1 in alkylation-induced tissue damage; in fact, cytotoxicity in WT and Aag transgenic mice was abrogated in the absence of Parp1. These results provide in vivo evidence that Aag-initiated BER may play a critical role in determining the side-effects of alkylating agent chemotherapies and that Parp1 plays a crucial role in Aag-mediated tissue damage.

  19. Use of flubendazole as a therapeutic agent against rotifers (Brachionus plicatilis) in intensive cultures of the harpacticoid copepod Tisbe holothuriae

    DEFF Research Database (Denmark)

    Steenfeldt, Svend Jørgen; Nielsen, Johan W.

    2010-01-01

    down production and subsequently use a therapeutic agent to eliminate all zooplankton in the system before restart with a stock culture free of rotifers. We tested flubendazole as a mean of controlling rotifers (Brachionus plicatilis) in intensive laboratory cultures of the harpacticoid copepod (Tisbe...... holothuria). Flubendazole was lethal to rotifers in concentrations as low as 0.05 mg L−1. There was no significant effect on the concentration of copepods, even at the highest concentration tested, i.e. 5.0 mg L−1 flubendazole. We conclude that flubendazole is an effective drug for control of B. plicatilis...

  20. Targeted Anticancer Immunotoxins and Cytotoxic Agents with Direct Killing Moieties

    Directory of Open Access Journals (Sweden)

    Koji Kawakami

    2006-01-01

    Full Text Available Despite the progress of the bioinformatics approach to characterize cell-surface antigens and receptors on tumor cells, it remains difficult to generate novel cancer vaccines or neutralizing monoclonal antibody therapeutics. Among targeted cancer therapeutics, biologicals with targetable antibodies or ligands conjugated or fused to toxins or chemicals for direct cell-killing ability have been developed over the last 2 decades. These conjugated or fused chimeric proteins are termed immunotoxins or cytotoxic agents. Two agents, DAB389IL-2 (ONTAKTM targeting the interleukin-2 receptor and CD33-calicheamicin (Mylotarg®, have been approved by the FDA for cutaneous T-cell lymphoma (CTCL and relapsed acute myeloid leukemia (AML, respectively. Such targetable agents, including RFB4(dsFv-PE38 (BL22, IL13-PE38QQR, and Tf-CRM107, are being tested in clinical trials. Several agents using unique technology such as a cleavable adapter or immunoliposomes with antibodies are also in the preclinical stage. This review summarizes the generation, mechanism, and development of these agents. In addition, possible future directions of this therapeutic approach are discussed.

  1. Nanoparticles for therapeutic and diagnostic applications

    OpenAIRE

    Chiu, Yin To

    2014-01-01

    Nanomedicine focuses on the development and engineering of novel and unique therapeutic and diagnostic agents that can overcome the challenges associated with using traditional modalities. Nanoparticles (NPs) in the size range between 1 and 1000 nm have many advantages for use in these applications, such as, low polydispersity, established characterization methodologies, and the ability to be loaded with therapeutics for diseases, conjugated to targeting ligands to enhance specificity, and co...

  2. Topical antifungal agents: an update.

    Science.gov (United States)

    Diehl, K B

    1996-10-01

    So many topical antifungal agents have been introduced that it has become very difficult to select the proper agent for a given infection. Nonspecific agents have been available for many years, and they are still effective in many situations. These agents include Whitfield's ointment, Castellani paint, gentian violet, potassium permanganate, undecylenic acid and selenium sulfide. Specific antifungal agents include, among others, the polyenes (nystatin, amphotericin B), the imidazoles (metronidazole, clotrimazole) and the allylamines (terbinafine, naftifine). Although the choice of an antifungal agent should be based on an accurate diagnosis, many clinicians believe that topical miconazole is a relatively effective agent for the treatment of most mycotic infections. Terbinafine and other newer drugs have primary fungicidal effects. Compared with older antifungal agents, these newer drugs can be used in lower concentrations and shorter therapeutic courses. Studies are needed to evaluate the clinical efficacies and cost advantages of both newer and traditional agents.

  3. DNA damage and repair in plants

    International Nuclear Information System (INIS)

    Britt, A.B.

    1996-01-01

    The biological impact of any DNA damaging agent is a combined function of the chemical nature of the induced lesions and the efficiency and accuracy of their repair. Although much has been learned frommicrobes and mammals about both the repair of DNA damage and the biological effects of the persistence of these lesions, much remains to be learned about the mechanism and tissue-specificity of repair in plants. This review focuses on recent work on the induction and repair of DNA damage in higher plants, with special emphasis on UV-induced DNA damage products. (author)

  4. The Therapeutic Potential of Monocyte/Macrophage Manipulation in the Treatment of Chemotherapy-Induced Painful Neuropathy

    Directory of Open Access Journals (Sweden)

    Karli Montague

    2017-11-01

    Full Text Available In cancer treatments a dose-limiting side-effect of chemotherapeutic agents is the development of neuropathic pain, which is poorly managed by clinically available drugs at present. Chemotherapy-induced painful neuropathy (CIPN is a major cause of premature cessation of treatment and so a greater understanding of the underlying mechanisms and the development of novel, more effective therapies, is greatly needed. In some cases, only a weak correlation between chemotherapy-induced pain and neuronal damage is observed both clinically and preclinically. As such, a critical role for non-neuronal cells, such as immune cells, and their communication with neurons in CIPN has recently been appreciated. In this mini-review, we will discuss preclinical evidence for the role of monocytes/macrophages in the periphery in CIPN, with a focus on that which is associated with the chemotherapeutic agents vincristine and paclitaxel. In addition we will discuss the potential mechanisms that regulate monocyte/macrophage–neuron crosstalk in this context. Informed by preclinical data, we will also consider the value of monocytes/macrophages as therapeutic targets for the treatment of CIPN clinically. Approaches that manipulate the signaling pathways discussed in this review show both promise and potential pitfalls. Nonetheless, they are emerging as innovative therapeutic targets with CX3CL1/R1-regulation of monocyte/macrophage–neuron communication currently emerging as a promising front-runner.

  5. New therapeutic agent for radiation synovectomy - preparation of 166Ho-EDTMP-HA particle

    International Nuclear Information System (INIS)

    Bai, H.; Jin, X.; Du, J.; Wang, F.; Chen, D.; Fan, H.; Cheng, Z.; Zhang, J.

    1997-01-01

    In order to prepare new therapeutical agent for radiation synovectomy, Hydroxyapatite (HA) was labelled with 166 Ho by EDTMP that had high affinity to HA particles. Radiolabelling of HA particles was divided into two steps, 166 Ho-EDTMP was prepared first; then mixed with HA particles completely and vibrated for 15 minutes on the micromixer at room temperature, washed 3 times with deionized water. Radiolabelling particle was separated from free 166 Ho via centrifugation to determine its radiolabelling efficiency. 166 Ho-EDTMP-HA and 166 Ho-EDTMP were injected into knee joint of normal rabbits respectively, every group was killed at different time postinjection, took out major organ and collected urine and blood, then weighted and determined their radio counts. HA particles, as a natural component of bone was known to have good compatibility with soft tissue and biodegrade into calcium and phosphate in vivo. It was readily prepared from common chemical and formed into particles of desired size range in a controlled process, it had high stability in vitro and vivo. Radiolabelling of HA particle with 166 Ho by EDTMP was simple to perform and provides an excellent labelling yield that was more than 95% under the optimal labelling condition. The optimal labelling condition at room temperature was pH 6.0-8.0 and vibration time 15 minutes. The absorbed capacity of HA particle was 5 mg Ho/g HA particle and size of radiolabelling particle was at range of 2-5,μm that is suitable for therapy of radiation synovectomy. 166 Ho-EDTMP-HA particle demonstrated high in vitro stability in either normal saline or 1% BSA solution, but instability under extremely acidic condition (pH 1-2). The control studies performed with 166 Ho-EDTMP not bound to HA particle provided information on the distribution of radioactivity that would occur upon leakage of the radiochemical compound from joint. Its short half-life, its extremely low leakage from the joint and its even distribution throughout

  6. Therapeutic strategies to improve control of hypertension.

    Science.gov (United States)

    Armario, Pedro; Waeber, Bernard

    2013-03-01

    Blood pressure is poorly controlled in most European countries and the control rate is even lower in high-risk patients such as patients with chronic kidney disease, diabetic patients or previous coronary heart disease. Several factors have been associated with poor control, some of which involve the characteristic of the patients themselves, such as socioeconomic factors, or unsuitable life-styles, other factors related to hypertension or to associated comorbidity, but there are also factors directly associated with antihypertensive therapy, mainly involving adherence problems, therapeutic inertia and therapeutic strategies unsuited to difficult-to-control hypertensive patients. It is common knowledge that only 30% of hypertensive patients can be controlled using monotherapy; all the rest require a combination of two or more antihypertensive drugs, and this can be a barrier to good adherence and log-term persistence in patients who also often need to use other drugs, such as antidiabetic agents, statins or antiplatelet agents. The fixed combinations of three antihypertensive agents currently available can facilitate long-term control of these patients in clinical practice. If well tolerated, a long-term therapeutic regimen that includes a diuretic, an ACE inhibitor or an angiotensin receptor blocker, and a calcium channel blocker is the recommended optimal triple therapy.

  7. Biologically important radiation damage in DNA

    International Nuclear Information System (INIS)

    Ward, J.F.

    1994-01-01

    Most DNA damage by the hydroxyl radical is confined to the bases, and this base damage represents an important component of locally multiply demanded sites (LMOS). The yields of the major damaged bases have been determined by gas chromatography mass spectrometry. For our propose, it was necessary to convert a known fraction of these damaged bases to strand breaks and then assay these labile sites as the increase in strand break yield over the normally observed level. Three potential agents by which this strategy of conversion of base damage to strand break could be implemented were identified in the original application: 1, Sl nuclease; 2, piperidine; and 3, base damage specific enzymes

  8. Orexin receptor antagonists as therapeutic agents for insomnia

    Directory of Open Access Journals (Sweden)

    Ana Clementina Equihua

    2013-12-01

    Full Text Available Insomnia is a common clinical condition characterized by difficulty initiating or maintaining sleep, or non-restorative sleep with impairment of daytime functioning.Currently, treatment for insomnia involves a combination of cognitive behavioral therapy and pharmacological therapy. Among pharmacological interventions, the most evidence exists for benzodiazepine receptor agonist drugs (GABAA receptor, although concerns persist regarding their safety and their limited efficacy. The use of these hypnotic medications must be carefully monitored for adverse effects.Orexin (hypocretin neuropeptides have been shown to regulate transitions between wakefulness and sleep by promoting cholinergic/monoaminergic neural pathways. This has led to the development of a new class of pharmacological agents that antagonize the physiological effects of orexin. The development of these agents may lead to novel therapies for insomnia without the side effect profile of hypnotics (e.g. impaired cognition, disturbed arousal, and motor balance difficulties. However, antagonizing a system that regulates the sleep-wake cycle may create an entirely different side effect profile. In this review, we discuss the role of orexin and its receptors on the sleep-wake cycle and that of orexin antagonists in the treatment of insomnia.

  9. Topical Botanical Agents for the Treatment of Psoriasis: A Systematic Review.

    Science.gov (United States)

    Farahnik, Benjamin; Sharma, Divya; Alban, Joseph; Sivamani, Raja K

    2017-08-01

    Patients with psoriasis often enquire about the use of numerous botanical therapeutics. It is important for dermatologists to be aware of the current evidence regarding these agents. We conducted a systematic literature search using the PubMed, MEDLINE, and EMBASE databases for controlled and uncontrolled clinical trials that assessed the use of topical botanical therapeutics for psoriasis. The search included the following keywords: 'psoriasis' and 'plant' or 'herbal' or 'botanical'. We also reviewed citations within articles to identify additional relevant sources. We then further refined the results by route of administration and the topical botanical agents are reviewed herein. A total of 27 controlled and uncontrolled clinical trials addressing the use of topical botanical agents for psoriasis were assessed in this review. We found that the most highly studied and most efficacious topical botanical therapeutics were Mahonia aquifolium, indigo naturalis, aloe vera, and, to a lesser degree, capsaicin. The most commonly reported adverse effects were local skin irritation, erythema, pruritus, burning, and pain. However, the overall evidence for these therapeutics remains limited in quantity and quality. The literature addresses a large number of studies in regard to botanicals for the treatment of psoriasis. While most agents appear to be safe, further research is necessary before topical botanical agents can be consistently recommended to patients.

  10. [New agents for hypercholesterolemia].

    Science.gov (United States)

    Pintó, Xavier; García Gómez, María Carmen

    2016-02-19

    An elevated proportion of high cardiovascular risk patients do not achieve the therapeutic c-LDL goals. This owes to physicians' inappropriate or insufficient use of cholesterol lowering medications or to patients' bad tolerance or therapeutic compliance. Another cause is an insufficient efficacy of current cholesterol lowering drugs including statins and ezetimibe. In addition, proprotein convertase subtilisin kexin type 9 inhibitors are a new cholesterol lowering medications showing safety and high efficacy to reduce c-LDL in numerous already performed or underway clinical trials, potentially allowing an optimal control of hypercholesterolemia in most patients. Agents inhibiting apolipoprotein B synthesis and microsomal transfer protein are also providing a new potential to decrease cholesterol in patients with severe hypercholesterolemia and in particular in homozygote familial hypercholesterolemia. Last, cholesteryl ester transfer protein inhibitors have shown powerful effects on c-HDL and c-LDL, although their efficacy in cardiovascular prevention and safety has not been demonstrated yet. We provide in this article an overview of the main characteristics of therapeutic agents for hypercholesterolemia, which have been recently approved or in an advanced research stage. Copyright © 2015 Elsevier España, S.L.U. All rights reserved.

  11. Pretreatment with UV light renders the chromatin in human fibroblasts more susceptible to the DNA-damaging agents bleomycin, gamma radiation and 8-methoxypsoralen

    International Nuclear Information System (INIS)

    Ljungman, Mats

    1989-01-01

    Confluent human fibroblast cultures were pretreated with either 254 nm UV light (UV) or methyl methanesulphonate (MMS), incubated at 37 0 C and subsequently challenged on ice with bleomycin (BLM), gamma-radiation or 8-methoxy-psoralen (MOP). The resulting number of challenge-induced DNA damages (measured as DNA strand breaks or cross-links) were compared with the numbers induced in similarly challenged but non-pretreated control cells. It was found that the timing of the subsequent challenge of cells pretreated with UV did significantly affect the amount of induced DNA damage. When the challenging agents were administered after a 10-20 min incubation period following UV pretreatment, the amount of induced DNA damage was increased 50% over control cells. In contrast, the timing of the subsequent challenge of cells pretreated with MMS has no influence on the level of challenge-induced damage. It is hypothesized that UV-irradiated chromatin undergoes a time-dependent decondensation that renders it more susceptible to the induction of strand breaks and cross-links by BLM, gamma-radiation and MOP. A possible role for chromatin decondensation in UV-induced excision repair is discussed. (author)

  12. Concanavalin A: A potential anti-neoplastic agent targeting apoptosis, autophagy and anti-angiogenesis for cancer therapeutics

    International Nuclear Information System (INIS)

    Li, Wen-wen; Yu, Jia-ying; Xu, Huai-long; Bao, Jin-ku

    2011-01-01

    Highlights: → ConA induces cancer cell death targeting apoptosis and autophagy. → ConA inhibits cancer cell angiogenesis. → ConA is utilized in pre-clinical and clinical trials. -- Abstract: Concanavalin A (ConA), a Ca 2+ /Mn 2+ -dependent and mannose/glucose-binding legume lectin, has drawn a rising attention for its remarkable anti-proliferative and anti-tumor activities to a variety of cancer cells. ConA induces programmed cell death via mitochondria-mediated, P73-Foxo1a-Bim apoptosis and BNIP3-mediated mitochondrial autophagy. Through IKK-NF-κB-COX-2, SHP-2-MEK-1-ERK, and SHP-2-Ras-ERK anti-angiogenic pathways, ConA would inhibit cancer cell survival. In addition, ConA stimulates cell immunity and generates an immune memory, resisting to the same genotypic tumor. These biological findings shed light on new perspectives of ConA as a potential anti-neoplastic agent targeting apoptosis, autophagy and anti-angiogenesis in pre-clinical or clinical trials for cancer therapeutics.

  13. Cisplatin encapsulated nanoparticle as a therapeutic agent for anticancer treatment

    Science.gov (United States)

    Eka Putra, Gusti Ngurah Putu; Huang, Leaf; Hsu, Yih-Chih

    2016-03-01

    The knowledge of manipulating size of biomaterials encapsulated drug into nano-scale particles has been researched and developed in treating cancer. Cancer is the second worldwide cause of death, therefore it is critical to treat cancers challenging with therapeutic modality of various mechanisms. Our preliminary investigation has studied cisplatin encapsulated into lipid-based nanoparticle and examined the therapeutic effect on xenografted animal model. We used mice with tumor volume ranging from 195 to 214 mm3 and then few mice were grouped into three groups including: control (PBS), lipid platinum chloride (LPC) nanoparticles and CDDP (cis-diamminedichloroplatinum(II) at dose of 3mg cisplatin /kg body weight. The effect of the treatment was observed for 12 days post-injection. It showed that LPC NPs demonstrated a better therapeutic effect compared to CDDP at same 3mg cisplatin/kg drug dose of tumor size reduction, 96.6% and 11.1% respectively. In addition, mouse body weight loss of LPC, CDDP and PBS treated group are 12.1%, 24.3% and 1.4%. It means that by compared to CDDP group, LPC group demonstrated less side effect as not much reduction of body weight have found. Our findings have shown to be a potential modality to further investigate as a feasible cancer therapy modality.

  14. Therapeutic benefit in patients switching tolterodine to other novel antimuscarinic agents.

    Science.gov (United States)

    Sánchez-Ballester, F; Miranda, P; Lizarraga, I; Rejas, J; Arumi, D

    2014-04-01

    To explore in the daily clinical practice setting that antimuscarinic, Fesoterodine or Solifenacin, provides a greater clinical benefit after changing their prior Overactive Bladder (OAB) therapy with tolterodine extended-release (ER) to other novel antimuscarinic agents. A post-hoc analysis of data from an observational multicenter, cross-sectional, retrospective study. Adult patients of both sexes, with OAB and OAB-V8 score≥8, who switched to fesoterodine or solifenacin within the 3-4 months before study visit from their prior tolterodine-ER-based therapy due to poor response were included. 92 patients were selected for each treatment group, matched (1:1) according to conditioned probability using the propensity score. Benefit of treatment change perceived by the physician and patient was evaluated by means of the Clinical Global Impression of Improvement subscale (CGI-I) and Treatment Benefit Scale (TBS), respectively. Degree of worry, bother and interference with daily living activities due to urinary symptoms, level of satisfaction, and preference for current treatment were also assessed. Fesoterodine provided a significantly greater improvement than solifenacina in terms of therapeutic benefit perceived by the physician according to ICG-I. 96.7% of the patients on fesoterodine treatment vs. 81.6% of the solifenacin group showed a score of improvement in TBS (P<.05). Fesoterodine was also better rated than solifenacin with regard to satisfaction and preference for the new treatment (93.4 vs. 78.2% P<.05). In daily clinical practice the switch from tolterodine LP to fesoterodine seems to provide greater benefits both from the physician's and the patient's point of view compared with those provided by solifenacin. Copyright © 2013 AEU. Published by Elsevier Espana. All rights reserved.

  15. Gallium a unique anti-resorptive agent in bone: Preclinical studies on its mechanisms of action

    International Nuclear Information System (INIS)

    Bockman, R.; Adelman, R.; Donnelly, R.; Brody, L.; Warrell, R.; Jones, K.W.

    1990-01-01

    The discovery of gallium as a new and unique agent for the treatment of metabolic bone disorders was in part fortuitous. Gallium is an exciting new therapeutic agent for the treatment of pathologic states characterized by accelerated bone resorption. Compared to other therapeutic metal compounds containing platinum or germanium, gallium affects its antiresorptive action without any evidence of a cytotoxic effect on bone cells. Gallium is unique amongst all therapeutically available antiresorptive agents in that it favors bone formation. 18 refs., 1 fig

  16. The DNA damage response during mitosis

    International Nuclear Information System (INIS)

    Heijink, Anne Margriet; Krajewska, Małgorzata; Vugt, Marcel A.T.M. van

    2013-01-01

    Cells are equipped with a cell-intrinsic signaling network called the DNA damage response (DDR). This signaling network recognizes DNA lesions and initiates various downstream pathways to coordinate a cell cycle arrest with the repair of the damaged DNA. Alternatively, the DDR can mediate clearance of affected cells that are beyond repair through apoptosis or senescence. The DDR can be activated in response to DNA damage throughout the cell cycle, although the extent of DDR signaling is different in each cell cycle phase. Especially in response to DNA double strand breaks, only a very marginal response was observed during mitosis. Early on it was recognized that cells which are irradiated during mitosis continued division without repairing broken chromosomes. Although these initial observations indicated diminished DNA repair and lack of an acute DNA damage-induced cell cycle arrest, insight into the mechanistic re-wiring of DDR signaling during mitosis was only recently provided. Different mechanisms appear to be at play to inactivate specific signaling axes of the DDR network in mitosis. Importantly, mitotic cells not simply inactivate the entire DDR, but appear to mark their DNA damage for repair after mitotic exit. Since the treatment of cancer frequently involves agents that induce DNA damage as well as agents that block mitotic progression, it is clinically relevant to obtain a better understanding of how cancer cells deal with DNA damage during interphase versus mitosis. In this review, the molecular details concerning DDR signaling during mitosis as well as the consequences of encountering DNA damage during mitosis for cellular fate are discussed

  17. The DNA damage response during mitosis

    Energy Technology Data Exchange (ETDEWEB)

    Heijink, Anne Margriet; Krajewska, Małgorzata; Vugt, Marcel A.T.M. van, E-mail: m.vugt@umcg.nl

    2013-10-15

    Cells are equipped with a cell-intrinsic signaling network called the DNA damage response (DDR). This signaling network recognizes DNA lesions and initiates various downstream pathways to coordinate a cell cycle arrest with the repair of the damaged DNA. Alternatively, the DDR can mediate clearance of affected cells that are beyond repair through apoptosis or senescence. The DDR can be activated in response to DNA damage throughout the cell cycle, although the extent of DDR signaling is different in each cell cycle phase. Especially in response to DNA double strand breaks, only a very marginal response was observed during mitosis. Early on it was recognized that cells which are irradiated during mitosis continued division without repairing broken chromosomes. Although these initial observations indicated diminished DNA repair and lack of an acute DNA damage-induced cell cycle arrest, insight into the mechanistic re-wiring of DDR signaling during mitosis was only recently provided. Different mechanisms appear to be at play to inactivate specific signaling axes of the DDR network in mitosis. Importantly, mitotic cells not simply inactivate the entire DDR, but appear to mark their DNA damage for repair after mitotic exit. Since the treatment of cancer frequently involves agents that induce DNA damage as well as agents that block mitotic progression, it is clinically relevant to obtain a better understanding of how cancer cells deal with DNA damage during interphase versus mitosis. In this review, the molecular details concerning DDR signaling during mitosis as well as the consequences of encountering DNA damage during mitosis for cellular fate are discussed.

  18. Damaging effect of therapeutic radiation on programmable pacemakers

    International Nuclear Information System (INIS)

    Adamec, R.; Haefliger, J.M.; Killisch, J.P.; Niederer, J.; Jaquet, P.

    1982-01-01

    Two series of present-day pacemakers were tested in vitro with pulsed x-ray radiation. The first series of 12 pacemakers consisted of 10 different types and models of demand pacemakers (VVI). The second series of 13 pacemakers had 9 different types and models of programmable pacemakers. Unlike the first series which showed only mild changes in frequency and pulse width, all but four of the programmable pacemakers presented sudden complete failure after different radiation doses. We conclude that direct pulse radiation at therapeutic levels of programmable pacemakers should be avoided

  19. Epigenetic Modulating Agents as a New Therapeutic Approach in Multiple Myeloma

    International Nuclear Information System (INIS)

    Maes, Ken; Menu, Eline; Van Valckenborgh, Els; Van Riet, Ivan; Vanderkerken, Karin; De Bruyne, Elke

    2013-01-01

    Multiple myeloma (MM) is an incurable B-cell malignancy. Therefore, new targets and drugs are urgently needed to improve patient outcome. Epigenetic aberrations play a crucial role in development and progression in cancer, including MM. To target these aberrations, epigenetic modulating agents, such as DNA methyltransferase inhibitors (DNMTi) and histone deacetylase inhibitors (HDACi), are under intense investigation in solid and hematological cancers. A clinical benefit of the use of these agents as single agents and in combination regimens has been suggested based on numerous studies in pre-clinical tumor models, including MM models. The mechanisms of action are not yet fully understood but appear to involve a combination of true epigenetic changes and cytotoxic actions. In addition, the interactions with the BM niche are also affected by epigenetic modulating agents that will further determine the in vivo efficacy and thus patient outcome. A better understanding of the molecular events underlying the anti-tumor activity of the epigenetic drugs will lead to more rational drug combinations. This review focuses on the involvement of epigenetic changes in MM pathogenesis and how the use of DNMTi and HDACi affect the myeloma tumor itself and its interactions with the microenvironment

  20. Surface modification of basalt with silane coupling agent on asphalt mixture moisture damage

    Energy Technology Data Exchange (ETDEWEB)

    Min, Yahong; Fang, Ying; Huang, Xiaojun; Zhu, Yinhui; Li, Wensheng [College of Chemistry and Chemical Engineering, Hunan University, Changsha, 410082 (China); Yuan, Jianmin [College of Materials Engineering, Hunan University, Changsha, 410082 (China); Tan, Ligang [College of Mechanical and Vehicle Engineering, Hunan University, Changsha, 410082 (China); Wang, Shuangyin [State Key Laboratory of Chem/Bio-Sensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, 410082 (China); Wu, Zhenjun, E-mail: wooawt@163.com [College of Chemistry and Chemical Engineering, Hunan University, Changsha, 410082 (China)

    2015-08-15

    Graphical abstract: - Highlights: • A new silane coupling agent was synthesized based on KH570. • Basalt surface was modified using the new silane coupling agent. • Chemical bond between basalt and the new silane coupling agent was formed. • Asphalt mixture which used modified basalt show superior water stability. - Abstract: A new silane coupling agent was synthesized based on γ-(methacryloyloxy) propyltrimethoxysilane (KH570). The surface of basalt rocks was modified by KH570 and the new silane coupling agent (NSCA), and the interfacial interaction between silane coupling agent and basalt was also studied. Fourier transform infrared (FTIR) spectroscopy and X-ray photoelectron spectroscopy (XPS) analysis showed that the silane coupling agent molecule bound strongly with basalt rocks. Scanning electronic microscopy (SEM) observation showed that a thin layer of coupling agent was formed on the surface of modified basalt. The boiling test and immersion Marshall test confirmed that the moisture sensitivity of basalt modified with the new silane coupling agent increased more significantly than that untreated and treated with KH570. The Retained Marshall Strength of basalt modified with the new coupling agent increased from 71.74% to 87.79% compared with untreated basalt. The results indicated that the new silane coupling agent played an important role in improving the interfacial performance between basalt and asphalt.

  1. T-oligo as an anticancer agent in colorectal cancer

    Energy Technology Data Exchange (ETDEWEB)

    Wojdyla, Luke; Stone, Amanda L. [Department of Biomedical Sciences, University of Illinois College of Medicine at Rockford, Rockford, IL (United States); Sethakorn, Nan [Department of Medicine, University of Chicago, Chicago, IL (United States); Uppada, Srijayaprakash B.; Devito, Joseph T. [Department of Biomedical Sciences, University of Illinois College of Medicine at Rockford, Rockford, IL (United States); Bissonnette, Marc [Department of Medicine, University of Chicago, Chicago, IL (United States); Puri, Neelu, E-mail: neelupur@uic.edu [Department of Biomedical Sciences, University of Illinois College of Medicine at Rockford, Rockford, IL (United States)

    2014-04-04

    Highlights: • T-oligo induces cell cycle arrest, senescence, apoptosis, and differentiation in CRC. • Treatment with T-oligo downregulates telomere-associated proteins. • T-oligo combined with an EGFR-TKI additively inhibits cellular proliferation. • T-oligo has potential as an effective therapeutic agent for CRC. - Abstract: In the United States, there will be an estimated 96,830 new cases of colorectal cancer (CRC) and 50,310 deaths in 2014. CRC is often detected at late stages of the disease, at which point there is no effective chemotherapy. Thus, there is an urgent need for effective novel therapies that have minimal effects on normal cells. T-oligo, an oligonucleotide homologous to the 3′-telomere overhang, induces potent DNA damage responses in multiple malignant cell types, however, its efficacy in CRC has not been studied. This is the first investigation demonstrating T-oligo-induced anticancer effects in two CRC cell lines, HT-29 and LoVo, which are highly resistant to conventional chemotherapies. In this investigation, we show that T-oligo may mediate its DNA damage responses through the p53/p73 pathway, thereby inhibiting cellular proliferation and inducing apoptosis or senescence. Additionally, upregulation of downstream DNA damage response proteins, including E2F1, p53 or p73, was observed. In LoVo cells, T-oligo induced senescence, decreased clonogenicity, and increased expression of senescence associated proteins p21, p27, and p53. In addition, downregulation of POT1 and TRF2, two components of the shelterin protein complex which protects telomeric ends, was observed. Moreover, we studied the antiproliferative effects of T-oligo in combination with an EGFR tyrosine kinase inhibitor, Gefitinib, which resulted in an additive inhibitory effect on cellular proliferation. Collectively, these data provide evidence that T-oligo alone, or in combination with other molecularly targeted therapies, has potential as an anti-cancer agent in CRC.

  2. The Protective Role of Hyaluronic Acid in Cr(VI-Induced Oxidative Damage in Corneal Epithelial Cells

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    Wei Wu

    2017-01-01

    Full Text Available Cr(VI exposure could produce kinds of intermediates and reactive oxygen species, both of which were related to DNA damage. Hyaluronan (HA has impressive biological functions and was reported to protect corneal epithelial cells against oxidative damage induced by ultraviolet B, benzalkonium chloride, and sodium lauryl sulfate. So the aim of our study was to investigate HA protection on human corneal epithelial (HCE cells against Cr(VI-induced toxic effects. The HCE cell lines were exposed to different concentrations of K2Cr2O7 (1.875, 3.75, 7.5, 15.0, and 30 μM or a combination of K2Cr2O7 and 0.2% HA and incubated with different times (15 min, 30 min, and 60 min. Our data showed that Cr(VI exposure could cause decreased cell viability, increased DNA damage, and ROS generation to the HCE cell lines. But incubation of HA increased HCE cell survival rates and decreased DNA damage and ROS generation induced by Cr(VI in a dose- and time-dependent manner. We report for the first time that HA can protect HCE cells against the toxicity of Cr(VI, indicating that it will be a promising therapeutic agent to corneal injuries caused by Cr(VI.

  3. The botulinum toxin as a therapeutic agent: molecular and pharmacological insights

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    Kukreja R

    2015-12-01

    Full Text Available Roshan Kukreja,1 Bal Ram Singh2 1Department of Chemistry and Biochemistry, University of Massachusetts, 2Botulinum Research Center, Institute of Advanced Sciences, Dartmouth, MA, USA Abstract: Botulinum neurotoxins (BoNTs, the most potent toxins known to mankind, are metalloproteases that act on nerve–muscle junctions to block exocytosis through a very specific and exclusive endopeptidase activity against soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE proteins of presynaptic vesicle fusion machinery. This very ability of the toxins to produce flaccid muscle paralysis through chemical denervation has been put to good use, and these potentially lethal toxins have been licensed to treat an ever expanding list of medical disorders and more popularly in the field of esthetic medicine. In most cases, therapeutic BoNT preparations are high-molecular-weight protein complexes consisting of BoNT, complexing proteins, and excipients. There is at least one isolated BoNT, which is free of complexing proteins in the market (Xeomin®. Each commercially available BoNT formulation is unique, differing mainly in molecular size and composition of complexing proteins, biological activity, and antigenicity. BoNT serotype A is marketed as Botox®, Dysport®, and Xeomin®, while BoNT type B is commercially available as Myobloc®. Nerve terminal intoxication by BoNTs is completely reversible, and the duration of therapeutic effects of BoNTs varies for different serotypes. Depending on the target tissue, BoNTs can block the cholinergic neuromuscular or cholinergic autonomic innervation of exocrine glands and smooth muscles. Therapeutic BoNTs exhibit a high safety and very limited adverse effects profile. Despite their established efficacy, the greatest concern with the use of therapeutic BoNTs is their propensity to elicit immunogenic reactions that might render the patient unresponsive to subsequent treatments, particularly in chronic

  4. Kinase inhibitors of the IGF-1R as a potential therapeutic agent for rheumatoid arthritis.

    Science.gov (United States)

    Tsushima, Hiroshi; Morimoto, Shinji; Fujishiro, Maki; Yoshida, Yuko; Hayakawa, Kunihiro; Hirai, Takuya; Miyashita, Tomoko; Ikeda, Keigo; Yamaji, Ken; Takamori, Kenji; Takasaki, Yoshinari; Sekigawa, Iwao; Tamura, Naoto

    2017-08-01

    We have previously shown that the inhibition of connective tissue growth factor (CTGF) is a potential therapeutic strategy against rheumatoid arthritis (RA). CTGF consists of four distinct modules, including the insulin-like growth factor binding protein (IGFBP). In serum, insulin-like growth factors (IGFs) bind IGFBPs, interact with the IGF-1 receptor (IGF-1 R), and regulate anabolic effects and bone metabolism. We investigated the correlation between IGF-1 and the pathogenesis of RA, and the inhibitory effect on osteoclastogenesis and angiogenesis of the small molecular weight kinase inhibitor of the IGF-1 R, NVP-AEW541, against pathogenesis of RA in vitro. Cell proliferation was evaluated by cell count and immunoblotting. The expression of IGF-1 and IGF-1 R was evaluated by RT-PCR. Osteoclastogenesis was evaluated using tartrate-resistant acid phosphatase staining, a bone resorption assay, and osteoclast-specific enzyme production. Angiogenesis was evaluated by a tube formation assay using human umbilical vein endothelial cells (HUVECs). The proliferation of MH7A cells was found to be inhibited in the presence of NVP-AEW541, and the phosphorylation of extracellular signal-regulated kinase (ERK) and Akt was downregulated in MH7A cells. IGF-1 and IGF-1 R mRNA expression levels were upregulated during formation of M-colony stimulating factor (M-CSF) and receptor activator of NF-κB ligand (RANKL)-mediated osteoclast formation. Moreover, osteoclastogenesis was suppressed in the presence of NVP-AEW541. The formation of the tubular network was enhanced by IGF-1, and this effect was neutralized by NVP-ARE541. Our findings suggest that NVP-AEW541 may be utilized as a potential therapeutic agent in the treatment of RA.

  5. The DNA damage response during mitosis.

    Science.gov (United States)

    Heijink, Anne Margriet; Krajewska, Małgorzata; van Vugt, Marcel A T M

    2013-10-01

    Cells are equipped with a cell-intrinsic signaling network called the DNA damage response (DDR). This signaling network recognizes DNA lesions and initiates various downstream pathways to coordinate a cell cycle arrest with the repair of the damaged DNA. Alternatively, the DDR can mediate clearance of affected cells that are beyond repair through apoptosis or senescence. The DDR can be activated in response to DNA damage throughout the cell cycle, although the extent of DDR signaling is different in each cell cycle phase. Especially in response to DNA double strand breaks, only a very marginal response was observed during mitosis. Early on it was recognized that cells which are irradiated during mitosis continued division without repairing broken chromosomes. Although these initial observations indicated diminished DNA repair and lack of an acute DNA damage-induced cell cycle arrest, insight into the mechanistic re-wiring of DDR signaling during mitosis was only recently provided. Different mechanisms appear to be at play to inactivate specific signaling axes of the DDR network in mitosis. Importantly, mitotic cells not simply inactivate the entire DDR, but appear to mark their DNA damage for repair after mitotic exit. Since the treatment of cancer frequently involves agents that induce DNA damage as well as agents that block mitotic progression, it is clinically relevant to obtain a better understanding of how cancer cells deal with DNA damage during interphase versus mitosis. In this review, the molecular details concerning DDR signaling during mitosis as well as the consequences of encountering DNA damage during mitosis for cellular fate are discussed. Copyright © 2013 Elsevier B.V. All rights reserved.

  6. Recent Progress in Functional Micellar Carriers with Intrinsic Therapeutic Activities for Anticancer Drug Delivery.

    Science.gov (United States)

    Qu, Ying; Chu, BingYang; Shi, Kun; Peng, JinRong; Qian, ZhiYong

    2017-12-01

    Polymeric micelles have presented superior delivery properties for poorly water-soluble chemotherapeutic agents. However, it remains discouraging that there may be some additional short or long-term toxicities caused by the metabolites of high quantities of carriers. If carriers had simultaneous therapeutic effects with the drug, these issues would not be a concern. For this, carriers not only simply act as drug carriers, but also exert an intrinsic therapeutic effect as a therapeutic agent. The functional micellar carriers would be beneficial to maximize the anticancer effect, overcome the drug resistance and reduce the systemic toxicity. In this review, we aim to summarize the recent progress on the development of functional micellar carriers with intrinsic anticancer activities for the delivery of anticancer drugs. This review focuses on the design strategies, properties of carriers and the drug loading behavior. In addition, the combinational therapeutic effects between carriers and chemotherapeutic agents are also discussed.

  7. Evaluation of gloves as a water bag coupling agent for therapeutic ultrasound

    Directory of Open Access Journals (Sweden)

    Lúcio Salustiano de Lima

    2017-03-01

    Full Text Available Abstract Introduction Therapeutic ultrasound (TUS is a widespread modality in physiotherapy, and the water bag technique is a coupling method employed in the presence of anatomical irregularities in the treatment area. The aim of the present study is to evaluate the acoustic attenuation of the water bag and its effectiveness as a TUS coupling agent. Methods The rated output powers (ROPs of the TUS equipment were evaluated based on IEC 61689. Then, a radiation force balance was used to measure ROP with and without a water bag (latex and nitrile gloves filled with deionized water between a TUS transducer and the cone-shaped target of the balance. Each experiment was performed five times for each nominal power (0.5, 1.0, 2.0, 3.0, 4.0, 5.0, 6.0, and 7.0 W and in the following configurations: without the water bag (A, with nitrile gloves and with (B and without (C a height controller, and latex gloves with (D and without (E height controller. ROPs obtained in different media were compared. Results The highest relative error of ROP was 16.72% for 0.5 W. Although the power values of the equipment were within the range recommended by IEC, there was a significant difference between the ROP values measured with A and with B, C and D. Conclusion As intensity differences below 0.5 W/cm2 are considered clinically not relevant, conditions A, B, C, D, or E can be used interchangeably.

  8. Impacts of the Human Gut Microbiome on Therapeutics.

    Science.gov (United States)

    Vázquez-Baeza, Yoshiki; Callewaert, Chris; Debelius, Justine; Hyde, Embriette; Marotz, Clarisse; Morton, James T; Swafford, Austin; Vrbanac, Alison; Dorrestein, Pieter C; Knight, Rob

    2018-01-06

    The human microbiome contains a vast source of genetic and biochemical variation, and its impacts on therapeutic responses are just beginning to be understood. This expanded understanding is especially important because the human microbiome differs far more among different people than does the human genome, and it is also dramatically easier to change. Here, we describe some of the major factors driving differences in the human microbiome among individuals and populations. We then describe some of the many ways in which gut microbes modify the action of specific chemotherapeutic agents, including nonsteroidal anti-inflammatory drugs and cardiac glycosides, and outline the potential of fecal microbiota transplant as a therapeutic. Intriguingly, microbes also alter how hosts respond to therapeutic agents through various pathways acting at distal sites. Finally, we discuss some of the computational and practical issues surrounding use of the microbiome to stratify individuals for drug response, and we envision a future where the microbiome will be modified to increase everyone's potential to benefit from therapy.

  9. A sonographic lesion index for Crohn's disease helps monitor changes in transmural bowel damage during therapy.

    Science.gov (United States)

    Zorzi, Francesca; Stasi, Elisa; Bevivino, Gerolamo; Scarozza, Patrizio; Biancone, Livia; Zuzzi, Sara; Rossi, Carla; Pallone, Francesco; Calabrese, Emma

    2014-12-01

    Therapeutic antibodies against tumor necrosis factor α (anti-TNF) are effective in patients with Crohn's disease (CD). Mucosal healing is a surrogate marker of efficacy, but little is known about the effects of anti-TNF agents on structural damage in the intestine. Small-intestine contrast ultrasonography (SICUS) is a valuable tool for assessing CD lesions. A new sonographic quantitative index (the sonographic lesion index for CD [SLIC]) was developed to quantify changes in CD lesions detected by SICUS. We explored whether the SLIC can be used to monitor transmural bowel damage in CD patients during anti-TNF therapy. We performed a prospective study of 29 patients with ileal or ileocolonic CD treated with anti-TNF agents; patients underwent SICUS before and after scheduled induction and maintenance therapy. To determine whether changes that can be detected by SICUS occur independently of anti-TNF therapy, 7 patients with ileal CD treated with mesalamine were enrolled as controls. A clinical response was defined as steroid-free remission, with CD activity index scores less than 150. We observed significant improvements in SLIC scores and subscores after induction and maintenance therapy with anti-TNFs, compared with before therapy. SLIC scores and subscores and index classes were improved significantly in patients with vs without clinical responses. Controls had no improvements in terms of CD activity index or SLIC scores, or index classes. Sonographic assessment using the quantitative index SLIC can be used to monitor changes in transmural bowel damage during anti-TNF therapy for CD. Copyright © 2014 AGA Institute. Published by Elsevier Inc. All rights reserved.

  10. Argan Oil as an Effective Nutri-Therapeutic Agent in Metabolic Syndrome: A Preclinical Study

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    Adil El Midaoui

    2017-11-01

    Full Text Available The present study aims at examining the effects of argan oil on the three main cardiovascular risk factors associated with metabolic syndrome (hypertension, insulin resistance and obesity and on one of its main complications, neuropathic pain. Male Sprague-Dawley rats had free access to a drinking solution containing 10% d-glucose or tap water for 12 weeks. The effect of argan oil was compared to that of corn oil given daily by gavage during 12 weeks in glucose-fed rats. Glucose-fed rats showed increases in systolic blood pressure, epididymal fat, plasma levels of triglycerides, leptin, glucose and insulin, insulin resistance, tactile and cold allodynia in association with a rise in superoxide anion production and NADPH oxidase activity in the thoracic aorta, epididymal fat and gastrocnemius muscle. Glucose-fed rats also showed rises in B1 receptor protein expression in aorta and gastrocnemius muscle. Argan oil prevented or significantly reduced all those anomalies with an induction in plasma adiponectin levels. In contrast, the same treatment with corn oil had a positive impact only on triglycerides, leptin, adiponectin and insulin resistance. These data are the first to suggest that argan oil is an effective nutri-therapeutic agent to prevent the cardiovascular risk factors and complications associated with metabolic syndrome.

  11. Dendrimers as Potential Therapeutic Tools in HIV Inhibition

    Directory of Open Access Journals (Sweden)

    Xiangbo Li

    2013-07-01

    Full Text Available The present treatments for HIV transfection include chemical agents and gene therapies. Although many chemical drugs, peptides and genes have been developed for HIV inhibition, a variety of non-ignorable drawbacks limited the efficiency of these materials. In this review, we discuss the application of dendrimers as both therapeutic agents and non-viral vectors of chemical agents and genes for HIV treatment. On the one hand, dendrimers with functional end groups combine with the gp120 of HIV and CD4 molecule of host cell to suppress the attachment of HIV to the host cell. Some of the dendrimers are capable of intruding into the cell and interfere with the later stages of HIV replication as well. On the other hand, dendrimers are also able to transfer chemical drugs and genes into the host cells, which conspicuously increase the anti-HIV activity of these materials. Dendrimers as therapeutic tools provide a potential treatment for HIV infection.

  12. DNA damage and polyploidization.

    Science.gov (United States)

    Chow, Jeremy; Poon, Randy Y C

    2010-01-01

    A growing body of evidence indicates that polyploidization triggers chromosomal instability and contributes to tumorigenesis. DNA damage is increasingly being recognized for its roles in promoting polyploidization. Although elegant mechanisms known as the DNA damage checkpoints are responsible for halting the cell cycle after DNA damage, agents that uncouple the checkpoints can induce unscheduled entry into mitosis. Likewise, defects of the checkpoints in several disorders permit mitotic entry even in the presence of DNA damage. Forcing cells with damaged DNA into mitosis causes severe chromosome segregation defects, including lagging chromosomes, chromosomal fragments and chromosomal bridges. The presence of these lesions in the cleavage plane is believed to abort cytokinesis. It is postulated that if cytokinesis failure is coupled with defects of the p53-dependent postmitotic checkpoint pathway, cells can enter S phase and become polyploids. Progress in the past several years has unraveled some of the underlying principles of these pathways and underscored the important role of DNA damage in polyploidization. Furthermore, polyploidization per se may also be an important determinant of sensitivity to DNA damage, thereby may offer an opportunity for novel therapies.

  13. Progranulin as a biomarker and potential therapeutic agent.

    Science.gov (United States)

    Abella, Vanessa; Pino, Jesús; Scotece, Morena; Conde, Javier; Lago, Francisca; Gonzalez-Gay, Miguel Angel; Mera, Antonio; Gómez, Rodolfo; Mobasheri, Ali; Gualillo, Oreste

    2017-10-01

    Progranulin is a cysteine-rich secreted protein with diverse pleiotropic actions and participates in several processes, such as inflammation or tumorigenesis. Progranulin was first identified as a growth factor and, recently, it was characterised as an adipokine implicated in obesity, insulin resistance and rheumatic disease. At a central level, progranulin acts as a neurotropic and neuroprotective factor and protects from neural degeneration. In this review, we summarise the most recent research advances concerning the potential role of progranulin as a therapeutic target and biomarker in cancer, neurodegenerative and inflammatory diseases. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. WE-FG-BRA-04: A Portable Confocal Microscope to Image Live Cell Damage Response Induced by Therapeutic Radiation

    Energy Technology Data Exchange (ETDEWEB)

    McFadden, C; Flint, D; Grosshans, D; Sawakuchi, G [The University of Texas MD Anderson Cancer Center, Houston, TX (United States); Sadetaporn, D [The University of Texas MD Anderson Cancer Center, Houston, TX (United States); Rice University, Houston, TX (United States); Asaithamby, A [UT Southwestern Medical Center, Dallas, TX (United States)

    2016-06-15

    Purpose: To construct a custom and portable fluorescence confocal laser-scanning microscope (FCLSM) that can be placed in the path of therapeutic radiation beams to study real-time radiation-induced damage response in live cells. Methods: We designed and constructed a portable FCLSM with three laser diodes for excitation (405, 488, and 635 nm). An objective lens focuses the excitation light and collects fluorescence from the sample. A pair of galvanometer mirrors scans/collects the laser beam/fluorescence along the focal plane (x/y-directions). A stepper motor stage scans in the axial direction and positions the x/y of the image field. Barrier filters and dichroic mirrors are used to route the spectral emission bands to the appropriate photodetector. An avalanche photodiode collects near-infrared fluorescence; a photodiode collects back-reflected 635 nm light; and a photomultiplier tube collects green fluorescence in the range of eGFP/eYFP. A 200-µm diameter pinhole was used to implement the confocal geometry for near-infrared and red channels and a 150-µm diameter pinhole for the green channel. Data acquisition and system control were achieved using a high-throughput data acquisition card. In-house software developed in LabVIEW was used to control the hardware, collect data from the photodetectors and reconstruct the confocal images. Results: 6 frames/s can be acquired for a 25 µm{sup 2} (128×128 pixels) field of view, visualizing the entire volume of the cell nucleus (∼10 µm depth) in <10 s. To demonstrate the usefulness of our FCLSM, we imaged gold nanoshells in live cells, radiation-induced damage in fibrosarcoma cells expressing eGFP tagged to a DNA repair protein, and neurons expressing eGFP. The system can also image particle tracks in fluorescent nuclear track detectors. Conclusion: We developed a versatile and portable FCLSM that allows radiobiology studies in live cells exposed to therapeutic radiation. The FCLSM can be placed in any vertical beam

  15. WE-FG-BRA-04: A Portable Confocal Microscope to Image Live Cell Damage Response Induced by Therapeutic Radiation

    International Nuclear Information System (INIS)

    McFadden, C; Flint, D; Grosshans, D; Sawakuchi, G; Sadetaporn, D; Asaithamby, A

    2016-01-01

    Purpose: To construct a custom and portable fluorescence confocal laser-scanning microscope (FCLSM) that can be placed in the path of therapeutic radiation beams to study real-time radiation-induced damage response in live cells. Methods: We designed and constructed a portable FCLSM with three laser diodes for excitation (405, 488, and 635 nm). An objective lens focuses the excitation light and collects fluorescence from the sample. A pair of galvanometer mirrors scans/collects the laser beam/fluorescence along the focal plane (x/y-directions). A stepper motor stage scans in the axial direction and positions the x/y of the image field. Barrier filters and dichroic mirrors are used to route the spectral emission bands to the appropriate photodetector. An avalanche photodiode collects near-infrared fluorescence; a photodiode collects back-reflected 635 nm light; and a photomultiplier tube collects green fluorescence in the range of eGFP/eYFP. A 200-µm diameter pinhole was used to implement the confocal geometry for near-infrared and red channels and a 150-µm diameter pinhole for the green channel. Data acquisition and system control were achieved using a high-throughput data acquisition card. In-house software developed in LabVIEW was used to control the hardware, collect data from the photodetectors and reconstruct the confocal images. Results: 6 frames/s can be acquired for a 25 µm 2 (128×128 pixels) field of view, visualizing the entire volume of the cell nucleus (∼10 µm depth) in <10 s. To demonstrate the usefulness of our FCLSM, we imaged gold nanoshells in live cells, radiation-induced damage in fibrosarcoma cells expressing eGFP tagged to a DNA repair protein, and neurons expressing eGFP. The system can also image particle tracks in fluorescent nuclear track detectors. Conclusion: We developed a versatile and portable FCLSM that allows radiobiology studies in live cells exposed to therapeutic radiation. The FCLSM can be placed in any vertical beam line

  16. Vorinostat induces reactive oxygen species and DNA damage in acute myeloid leukemia cells.

    Directory of Open Access Journals (Sweden)

    Luca A Petruccelli

    Full Text Available Histone deacetylase inhibitors (HDACi are promising anti-cancer agents, however, their mechanisms of action remain unclear. In acute myeloid leukemia (AML cells, HDACi have been reported to arrest growth and induce apoptosis. In this study, we elucidate details of the DNA damage induced by the HDACi vorinostat in AML cells. At clinically relevant concentrations, vorinostat induces double-strand breaks and oxidative DNA damage in AML cell lines. Additionally, AML patient blasts treated with vorinostat display increased DNA damage, followed by an increase in caspase-3/7 activity and a reduction in cell viability. Vorinostat-induced DNA damage is followed by a G2-M arrest and eventually apoptosis. We found that pre-treatment with the antioxidant N-acetyl cysteine (NAC reduces vorinostat-induced DNA double strand breaks, G2-M arrest and apoptosis. These data implicate DNA damage as an important mechanism in vorinostat-induced growth arrest and apoptosis in both AML cell lines and patient-derived blasts. This supports the continued study and development of vorinostat in AMLs that may be sensitive to DNA-damaging agents and as a combination therapy with ionizing radiation and/or other DNA damaging agents.

  17. Vorinostat Induces Reactive Oxygen Species and DNA Damage in Acute Myeloid Leukemia Cells

    Science.gov (United States)

    Pettersson, Filippa; Retrouvey, Hélène; Skoulikas, Sophia; Miller, Wilson H.

    2011-01-01

    Histone deacetylase inhibitors (HDACi) are promising anti-cancer agents, however, their mechanisms of action remain unclear. In acute myeloid leukemia (AML) cells, HDACi have been reported to arrest growth and induce apoptosis. In this study, we elucidate details of the DNA damage induced by the HDACi vorinostat in AML cells. At clinically relevant concentrations, vorinostat induces double-strand breaks and oxidative DNA damage in AML cell lines. Additionally, AML patient blasts treated with vorinostat display increased DNA damage, followed by an increase in caspase-3/7 activity and a reduction in cell viability. Vorinostat-induced DNA damage is followed by a G2-M arrest and eventually apoptosis. We found that pre-treatment with the antioxidant N-acetyl cysteine (NAC) reduces vorinostat-induced DNA double strand breaks, G2-M arrest and apoptosis. These data implicate DNA damage as an important mechanism in vorinostat-induced growth arrest and apoptosis in both AML cell lines and patient-derived blasts. This supports the continued study and development of vorinostat in AMLs that may be sensitive to DNA-damaging agents and as a combination therapy with ionizing radiation and/or other DNA damaging agents. PMID:21695163

  18. Power Doppler sonography and ultrasound contrast agent in assessing rheumatoid synovitis

    Directory of Open Access Journals (Sweden)

    F. Salaffi

    2011-09-01

    Full Text Available Pannus formation is a fundamental event in the pathogenesis of rheumatoid arthritis and its hypervascularisation seems to be crucial to the development of joint damage. High-resolution greyscale ultrasonography is a safe, quick, and inexpensive imaging tool that allows an accurate detection of even minimal morphostructural changes in patients with rheumatoid arthritis, including joint effusion, thickening of synovial membrane and bone erosions. More recently, power Doppler sonography has proved to be a reliable tool for semiquantitative assessment of the vascularity of the synovial tissue. The contrast-enhanced power Doppler sonography seems to be a helpful adjunct in assessing synovitis and the therapeutic response to the different therapies in patients with rheumatoid arthritis. The aim of this radiological vignette was to show a representative example of use of power Doppler sonography with contrast agent in assessing rheumatoid synovitis.

  19. Insulin and Insulin-Sensitizing Drugs in Neurodegeneration: Mitochondria as Therapeutic Targets

    Directory of Open Access Journals (Sweden)

    Paula I. Moreira

    2009-12-01

    Full Text Available Insulin, besides its glucose lowering effects, is involved in the modulation of lifespan, aging and memory and learning processes. As the population ages, neurodegenerative disorders become epidemic and a connection between insulin signaling dysregulation, cognitive decline and dementia has been established. Mitochondria are intracellular organelles that despite playing a critical role in cellular metabolism are also one of the major sources of reactive oxygen species. Mitochondrial dysfunction, oxidative stress and neuroinflammation, hallmarks of neurodegeneration, can result from impaired insulin signaling. Insulin-sensitizing drugs such as the thiazolidinediones are a new class of synthetic compounds that potentiate insulin action in the target tissues and act as specific agonists of the peroxisome proliferator-activated receptor gamma (PPAR-γ. Recently, several PPAR agonists have been proposed as novel and possible therapeutic agents for neurodegenerative disorders. Indeed, the literature shows that these agents are able to protect against mitochondrial dysfunction, oxidative damage, inflammation and apoptosis. This review discusses the role of mitochondria and insulin signaling in normal brain function and in neurodegeneration. Furthermore, the potential protective role of insulin and insulin sensitizers in Alzheimer´s, Parkinson´s and Huntington´s diseases and amyotrophic lateral sclerosis will be also discussed.

  20. Kidney in diabetes: from organ damage target to therapeutic target.

    Science.gov (United States)

    Salvatore, Teresa; Carbonara, Ornella; Cozzolino, Domenico; Torella, Roberto; Nasti, Rodolfo; Lascar, Nadia; Sasso, Ferdinando Carlo

    2011-09-01

    Despite the growing of pharmacological options for the treatment of diabetes, epidemiological studies suggest that a substantial proportion of patients does not achieve glycemic goals and so suffers from the risk of chronic complications. This review explores the inhibition of renal glucose reabsorption as a novel approach to treat hyperglycemia. Sodium-glucose cotransporter 2 (SGLT2), a low-affinity high-capacity transporter located in the brush-border membrane of the early segment (S1) of the proximal renal tubule, accounts for about 90% of the reabsorption of glucose from tubular fluid. Competitive inhibitors of SGLT2 that are responsible for renal excretion of glucose provide a unique mechanism to potentially lower the elevated blood glucose levels in patients with diabetes. They act independently of insulin secretion, thereby minimizing the risk of hypoglycemia and weight gain, to control energy balance in a negative direction, a distinctive advantage of this class of drugs over existing oral hypoglycemic agents. Although this group of medications is still under investigation, it appears to be safe and generally well tolerated and it would be expected to improve the treatment of type 2 diabetes as monotherapy or in combination with other oral or parenteral agents. Dapagliflozin is the first agent within this class, which induces clinically meaningful reductions in FPG, PPG, HbA1c, and body weight in type 2 diabetes.

  1. [Supramolecular Agents for Theranostics].

    Science.gov (United States)

    Deyev, S M; Lebedenko, E N

    2015-01-01

    This mini-review summarizes recent data obtained in the process of creation of a versatile module platform suitable for construction of supramolecular theranostic agents. As an example, we consider multifunctional hybrid agents for imaging and elimination of cancer cells. The use of an adapter protein system barnase:barstar for producing targeted multifunctional hybrid structures on the basis of highly specific peptides and mini-antibodies as addressing modules and recombinant proteins and/or nanoparticles of different nature (quantum dots, nanogold, magnetic nanoparticles, nanodiamonds, upconverting nanophosphores, polymer nanoparticles) as agents visualizing and damaging cancer cells is described. New perspectives for creation of selective and highly effective compounds for theranostics and personified medicine are contemplated.

  2. Chemotherapeutic agent and tracer composition and use thereof

    International Nuclear Information System (INIS)

    Babb, A. L.

    1985-01-01

    A therapeutic composition suitable for extracorporeal treatment of whole blood comprises a dialyzable chemotherapeutic agent and a dialyzable fluorescable tracer means. The removal rate of the fluorescable tracer compound from treated blood during hemodialysis is a function of the removal rate of unreacted chemotherapeutic agent present. The residual chemotherapeutic agent concentration after hemodialysis is ascertained by measuring the concentration of the fluorescable tracer compound in a dialysate using fluorometric techniques

  3. Mechanisms of DNA damage repair in adult stem cells and implications for cancer formation.

    Science.gov (United States)

    Weeden, Clare E; Asselin-Labat, Marie-Liesse

    2018-01-01

    Maintenance of genomic integrity in tissue-specific stem cells is critical for tissue homeostasis and the prevention of deleterious diseases such as cancer. Stem cells are subject to DNA damage induced by endogenous replication mishaps or exposure to exogenous agents. The type of DNA lesion and the cell cycle stage will invoke different DNA repair mechanisms depending on the intrinsic DNA repair machinery of a cell. Inappropriate DNA repair in stem cells can lead to cell death, or to the formation and accumulation of genetic alterations that can be transmitted to daughter cells and so is linked to cancer formation. DNA mutational signatures that are associated with DNA repair deficiencies or exposure to carcinogenic agents have been described in cancer. Here we review the most recent findings on DNA repair pathways activated in epithelial tissue stem and progenitor cells and their implications for cancer mutational signatures. We discuss how deep knowledge of early molecular events leading to carcinogenesis provides insights into DNA repair mechanisms operating in tumours and how these could be exploited therapeutically. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. Extracts of Crataegus oxyacantha and Rosmarinus officinalis Attenuate Ischemic Myocardial Damage by Decreasing Oxidative Stress and Regulating the Production of Cardiac Vasoactive Agents

    Directory of Open Access Journals (Sweden)

    Raúl Enrique Cuevas-Durán

    2017-11-01

    Full Text Available Numerous studies have supported a role for oxidative stress in the development of ischemic damage and endothelial dysfunction. Crataegus oxyacantha (Co and Rosmarinus officinalis (Ro extracts are polyphenolic-rich compounds that have proven to be efficient in the treatment of cardiovascular diseases. We studied the effect of extracts from Co and Ro on the myocardial damage associated with the oxidative status and to the production of different vasoactive agents. Rats were assigned to the following groups: (a sham; (b vehicle-treated myocardial infarction (MI (MI-V; (c Ro extract-treated myocardial infarction (MI-Ro; (d Co extract-treated myocardial infarction (MI-Co; or (e Ro+Co-treated myocardial infarction (MI-Ro+Co. Ro and Co treatments increased total antioxidant capacity, the expression of superoxide dismutase (SOD-Cu2+/Zn2+, SOD-Mn2+, and catalase, with the subsequent decline of malondialdehyde and 8-hydroxy-2′-deoxyguanosine levels. The extracts diminished vasoconstrictor peptide levels (angiotensin II and endothelin-1, increased vasodilators agents (angiotensin 1–7 and bradikinin and improved nitric oxide metabolism. Polyphenol treatment restored the left intraventricular pressure and cardiac mechanical work. We conclude that Ro and Co treatment attenuate morphological and functional ischemic-related changes by both an oxidant load reduction and improvement of the balance between vasoconstrictors and vasodilators.

  5. Hypoxia-mimetic agents inhibit proliferation and alter the morphology of human umbilical cord-derived mesenchymal stem cells

    Directory of Open Access Journals (Sweden)

    Zeng Hui-Lan

    2011-08-01

    Full Text Available Abstract Background The therapeutic efficacy of human mesenchymal stem cells (hMSCs for the treatment of hypoxic-ischemic diseases is closely related to level of hypoxia in the damaged tissues. To elucidate the potential therapeutic applications and limitations of hMSCs derived from human umbilical cords, the effects of hypoxia on the morphology and proliferation of hMSCs were analyzed. Results After treatment with DFO and CoCl2, hMSCs were elongated, and adjacent cells were no longer in close contact. In addition, vacuole-like structures were observed within the cytoplasm; the rough endoplasmic reticulum expanded, and expanded ridges were observed in mitochondria. In addition, DFO and CoCl2 treatments for 48 h significantly inhibited hMSCs proliferation in a concentration-dependent manner (P Conclusions The hypoxia-mimetic agents, DFO and CoCl2, alter umbilical cord-derived hMSCs morphology and inhibit their proliferation through influencing the cell cycle.

  6. {sup 166} Ho-HA Evaluation as therapeutic agent for rheumatoid arthritis treatment; Evaluacion de {sup 166}Ho-Ha como agente terapeutico en el tratamiento de la artritis reumatoidea

    Energy Technology Data Exchange (ETDEWEB)

    Chandia, M; Errazu, X [Comision Chilena de Energia Nuclear, Santiago (Chile); Mendoza, P [Departamento de Medicina Nuclear, Hospital Militar, Santiago (Chile); Troncoso, F [Comision Chilena de Energia Nuclear, Santiago (Chile); Jofre, J; Sierralta, P [Departamento de Medicina Nuclear, Hospital Militar, Santiago (Chile)

    2003-01-01

    Aim: Rheumatoid arthritis is a limiting disease having, among its pathological features, the inflammation of synovial tissue with progressive and later destruction of the articulation. This lead to joint deformation and loss of its function, generating pain and reducing the mobility of the affected articulation. The aim was to evaluate {sup 166}Ho-Hydroxyapatite ({sup 166} Ho-HA) as potential radiopharmaceutical for the syntomatic treatment of chronic and acute arthritis Materials and Methods: {sup 166}Holmiun was produced by irradiation of Ho{sub 2}O{sub 3} at La Reina Research Reactor, Nuclear Chilean Energy Commission. Hydroxyapatite was in-house synthetized. Its labelling and quality controls follows the internationally accepted procedures. An antigen arthritis was induced to eight New Zealand rabbits with the {sup 166}Ho-HA radiochemical being administred thereafter in two dosage modalities (single and double). The compound therapeutic efficiency was evaluated based upon clinical improvement and images from the inflamated articulation using {sup 67}Ga citrate before and after {sup 166} Ho-HA injection. Results: The radiochemical purity of the innoculated compound was greater than 98% as measured under sterility conditions. Clinically, an inflamation reduction (2 cm), appetite improvement and general well being was observed. The {sup 166} Ho-HA distribution and localization was monitored using gamma camera images taken at 4 and 24 h. There was no evidence of extraarticular leakage. From the {sup 67}Ga citrate imaging, the acute group shows an overall improvement of well being corresponding to a lesser uptake at the inflamated articulation, regarding to the chronic group. The {sup 166}Ho-HA double dosis, compared to the single dosis, suggest a reduced uptake of {sup 67}Ga citrate at the inflamated tissue, meaning an increased therapeutic effect. Conclusions: {sup 166} Ho-HA is usefull as therapeutic agent for the syntomatic treatment of rheumatoideal arthritis

  7. DNA damage by X-rays and their impact on replication processes

    International Nuclear Information System (INIS)

    Parplys, Ann Christin; Petermann, Eva; Petersen, Cordula; Dikomey, Ekkehard; Borgmann, Kerstin

    2012-01-01

    Background: Replication-dependent radiosensitization of tumors ranks among the most promising tools for future improvements in tumor therapy. However, cell cycle checkpoint signaling during S phase is a key for maintaining genomic stability after ionizing irradiation allowing DNA damage repair by stabilizing replication forks, inhibiting new origin firing and recruiting DNA repair proteins. As the impact of the different types of DNA damage induced by ionizing radiation on replication fork functionality has not been investigated, this study was performed in tumor cells treated with various agents that induce specific DNA lesions. Methods: U2OS cells were exposed to methyl methanesulfonate (MMS) to induce base damage, low or high concentrations of hydrogen peroxide for the induction of SSBs, Topotecan to induce DSBs at replication, Mitomycin C (MMC) to induce interstrand cross-links or ionizing irradiation to analyze all damages. Chk1 phosphorylation, origin firing and replication fork progression, and cell cycle distribution were analyzed. Results: In our system, the extent of Chk1 phosphorylation was dependent on the type of damage induced and prolonged Chk1 phosphorylation correlated with the inhibition of replication initiation. Ionizing radiation, high concentrations of hydrogen peroxide, and Topotecan affected replication elongation much more strongly that the other agents. Almost all agents induced a slight increase in the S phase population but subsequent G2 arrest was only observed in response to those agents that strongly inhibited replication elongation and caused prolonged Chk1 phosphorylation. Conclusions: Our data suggest that to improve radiotherapy, radiosensitivity in S phase could be increased by combining irradiation with agents that induce secondary DSB or inhibit checkpoint signaling, such as inhibitors of PARP or Chk1.

  8. DNA DAMAGE QUANTITATION BY ALKALINE GEL ELECTROPHORESIS.

    Energy Technology Data Exchange (ETDEWEB)

    SUTHERLAND,B.M.; BENNETT,P.V.; SUTHERLAND, J.C.

    2004-03-24

    Physical and chemical agents in the environment, those used in clinical applications, or encountered during recreational exposures to sunlight, induce damages in DNA. Understanding the biological impact of these agents requires quantitation of the levels of such damages in laboratory test systems as well as in field or clinical samples. Alkaline gel electrophoresis provides a sensitive (down to {approx} a few lesions/5Mb), rapid method of direct quantitation of a wide variety of DNA damages in nanogram quantities of non-radioactive DNAs from laboratory, field, or clinical specimens, including higher plants and animals. This method stems from velocity sedimentation studies of DNA populations, and from the simple methods of agarose gel electrophoresis. Our laboratories have developed quantitative agarose gel methods, analytical descriptions of DNA migration during electrophoresis on agarose gels (1-6), and electronic imaging for accurate determinations of DNA mass (7-9). Although all these components improve sensitivity and throughput of large numbers of samples (7,8,10), a simple version using only standard molecular biology equipment allows routine analysis of DNA damages at moderate frequencies. We present here a description of the methods, as well as a brief description of the underlying principles, required for a simplified approach to quantitation of DNA damages by alkaline gel electrophoresis.

  9. Supramolecular Nanoparticles for Molecular Diagnostics and Therapeutics

    Science.gov (United States)

    Chen, Kuan-Ju

    Over the past decades, significant efforts have been devoted to explore the use of various nanoparticle-based systems in the field of nanomedicine, including molecular imaging and therapy. Supramolecular synthetic approaches have attracted lots of attention due to their flexibility, convenience, and modularity for producing nanoparticles. In this dissertation, the developmental story of our size-controllable supramolecular nanoparticles (SNPs) will be discussed, as well as their use in specific biomedical applications. To achieve the self-assembly of SNPs, the well-characterized molecular recognition system (i.e., cyclodextrin/adamantane recognition) was employed. The resulting SNPs, which were assembled from three molecular building blocks, possess incredible stability in various physiological conditions, reversible size-controllability and dynamic disassembly that were exploited for various in vitro and in vivo applications. An advantage of using the supramolecular approach is that it enables the convenient incorporation of functional ligands onto SNP surface that confers functionality ( e.g., targeting, cell penetration) to SNPs. We utilized SNPs for molecular imaging such as magnetic resonance imaging (MRI) and positron emission tomography (PET) by introducing reporter systems (i.e., radio-isotopes, MR contrast agents, and fluorophores) into SNPs. On the other hand, the incorporation of various payloads, including drugs, genes and proteins, into SNPs showed improved delivery performance and enhanced therapeutic efficacy for these therapeutic agents. Leveraging the powers of (i) a combinatorial synthetic approach based on supramolecular assembly and (ii) a digital microreactor, a rapid developmental pathway was developed that is capable of screening SNP candidates for the ideal structural and functional properties that deliver optimal performance. Moreover, SNP-based theranostic delivery systems that combine reporter systems and therapeutic payloads into a

  10. Distinct patterns of DNA damage response and apoptosis correlate with Jak/Stat and PI3kinase response profiles in human acute myelogenous leukemia.

    Directory of Open Access Journals (Sweden)

    David B Rosen

    Full Text Available BACKGROUND: Single cell network profiling (SCNP utilizing flow cytometry measures alterations in intracellular signaling responses. Here SCNP was used to characterize Acute Myeloid Leukemia (AML disease subtypes based on survival, DNA damage response and apoptosis pathways. METHODOLOGY AND PRINCIPAL FINDINGS: Thirty four diagnostic non-M3 AML samples from patients with known clinical outcome were treated with a panel of myeloid growth factors and cytokines, as well as with apoptosis-inducing agents. Analysis of induced Jak/Stat and PI3K pathway responses in blasts from individual patient samples identified subgroups with distinct signaling profiles that were not seen in the absence of a modulator. In vitro exposure of patient samples to etoposide, a DNA damaging agent, revealed three distinct "DNA damage response (DDR/apoptosis" profiles: 1 AML blasts with a defective DDR and failure to undergo apoptosis; 2 AML blasts with proficient DDR and failure to undergo apoptosis; 3 AML blasts with proficiency in both DDR and apoptosis pathways. Notably, AML samples from clinical responders fell within the "DDR/apoptosis" proficient profile and, as well, had low PI3K and Jak/Stat signaling responses. In contrast, samples from clinical non responders had variable signaling profiles often with in vitro apoptotic failure and elevated PI3K pathway activity. Individual patient samples often harbored multiple, distinct, leukemia-associated cell populations identifiable by their surface marker expression, functional performance of signaling pathway in the face of cytokine or growth factor stimulation, as well as their response to apoptosis-inducing agents. CONCLUSIONS AND SIGNIFICANCE: Characterizing and tracking changes in intracellular pathway profiles in cell subpopulations both at baseline and under therapeutic pressure will likely have important clinical applications, potentially informing the selection of beneficial targeted agents, used either alone or in

  11. Development of a Multifaceted Ovarian Cancer Therapeutic and Imaging Agent

    National Research Council Canada - National Science Library

    Markland, Francis S

    2008-01-01

    ...%. This project outlines the development of a recombinant version of a member of a class of proteins known as disintegrins as an innovative imaging and diagnostic agent for ovarian cancer (OC). Vicrostatin (VN...

  12. In vivo antimicrobial activity of silver nanoparticles produced via a green chemistry synthesis using Acacia rigidula as a reducing and capping agent.

    Science.gov (United States)

    Escárcega-González, Carlos Enrique; Garza-Cervantes, J A; Vázquez-Rodríguez, A; Montelongo-Peralta, Liliana Zulem; Treviño-González, M T; Díaz Barriga Castro, E; Saucedo-Salazar, E M; Chávez Morales, R M; Regalado Soto, D I; Treviño González, F M; Carrazco Rosales, J L; Cruz, Rocío Villalobos; Morones-Ramírez, José Rubén

    2018-01-01

    One of the main issues in the medical field and clinical practice is the development of novel and effective treatments against infections caused by antibiotic-resistant bacteria. One avenue that has been approached to develop effective antimicrobials is the use of silver nanoparticles (Ag-NPs), since they have been found to exhibit an efficient and wide spectrum of antimicrobial properties. Among the main drawbacks of using Ag-NPs are their potential cytotoxicity against eukaryotic cells and the latent environmental toxicity of their synthesis methods. Therefore, diverse green synthesis methods, which involve the use of environmentally friendly plant extracts as reductive and capping agents, have become attractive to synthesize Ag-NPs that exhibit antimicrobial effects against resistant bacteria at concentrations below toxicity thresholds for eukaryotic cells. In this study, we report a green one-pot synthesis method that uses Acacia rigidula extract as a reducing and capping agent, to produce Ag-NPs with applications as therapeutic agents to treat infections in vivo. The Ag-NPs were characterized using transmission electron microscopy (TEM), high-resolution TEM, selected area electron diffraction, energy-dispersive spectroscopy, ultraviolet-visible, and Fourier transform infrared. We show that Ag-NPs are spherical with a narrow size distribution. The Ag-NPs show antimicrobial activities in vitro against Gram-negative ( Escherichia coli , Pseudomonas aeruginosa , and a clinical multidrug-resistant strain of P. aeruginosa ) and Gram-positive ( Bacillus subtilis ) bacteria. Moreover, antimicrobial effects of the Ag-NPs, against a resistant P. aeruginosa clinical strain, were tested in a murine skin infection model. The results demonstrate that the Ag-NPs reported in this work are capable of eradicating pathogenic resistant bacteria in an infection in vivo. In addition, skin, liver, and kidney damage profiles were monitored in the murine infection model, and the

  13. Early models of DNA damage formation

    International Nuclear Information System (INIS)

    Śmiałek, Małgorzata A

    2012-01-01

    Quantification of DNA damage, induced by various types of incident radiation as well as chemical agents, has been the subject of many theoretical and experimental studies, supporting the development of modern cancer therapy. The primary observations showed that many factors can lead to damage of DNA molecules. It became clear that the development of experimental techniques for exploring this phenomenon is required. Another problem was simultaneously dealt with, anticipating on how the damage is distributed within the double helix of the DNA molecule and how the single strand break formation and accumulation can influence the lethal double strand break formation. In this work the most important probabilistic models for DNA strand breakage and damage propagation are summarized and compared.

  14. Nerve agent intoxication: Recent neuropathophysiological findings and subsequent impact on medical management prospects

    International Nuclear Information System (INIS)

    Collombet, Jean-Marc

    2011-01-01

    This manuscript provides a survey of research findings catered to the development of effective countermeasures against nerve agent poisoning over the past decade. New neuropathophysiological distinctive features as regards organophosphate (OP) intoxication are presented. Such leading neuropathophysiological features include recent data on nerve agent-induced neuropathology, related peripheral or central nervous system inflammation and subsequent angiogenesis process. Hence, leading countermeasures against OP exposure are down-listed in terms of pre-treatment, protection or decontamination and emergency treatments. The final chapter focuses on the description of the self-repair attempt encountered in lesioned rodent brains, up to 3 months after soman poisoning. Indeed, an increased proliferation of neuronal progenitors was recently observed in injured brains of mice subjected to soman exposure. Subsequently, the latter experienced a neuronal regeneration in damaged brain regions such as the hippocampus and amygdala. The positive effect of a cytokine treatment on the neuronal regeneration and subsequent cognitive behavioral recovery are also discussed in this review. For the first time, brain cell therapy and neuronal regeneration are considered as a valuable contribution towards delayed treatment against OP intoxication. To date, efficient delayed treatment was lacking in the therapeutic resources administered to patients contaminated by nerve agents. - Highlights: → This review focuses on neuropathophysiology following nerve agent poisoning in mice. → Extensive data on long-term neuropathology and related inflammation are provided here. → Delayed self-repair attempts encountered in lesioned rodent brains are also described. → Cell therapy is considered as a valuable treatment against nerve agent intoxication.

  15. A comparative study on the cost of new antibiotics and drugs of other therapeutic categories.

    Science.gov (United States)

    Falagas, Matthew E; Fragoulis, Konstantinos N; Karydis, Ioannis

    2006-12-20

    Drug treatment is becoming more expensive due to the increased cost for the introduction of new drugs, and there seems to be an uneven distribution of medication cost for different therapeutic categories. We hypothesized that the cost of new antimicrobial agents may differ from that of other therapeutic categories and this may play a role in the stagnation of development of new antibiotics. We performed a pharmaco-economical comparative analysis of the drug cost of treatment for new agents introduced in the United States drug market in various therapeutic categories. We calculated the drug cost (in US dollars) of a ten-day treatment of all new drugs approved by the FDA during the period between January 1997 and July 2003, according to the 2004 Red Book Pharmacy's Fundamental Reference. New anti-neoplastic agents were found to be the most expensive drugs in comparison to all other therapeutic categories, with a median ten-day drug-treatment cost of US$848 compared to the median ten-day drug-treatment costs of all other categories ranging from US$29 to US$301. On the other hand, new antimicrobial drugs were found to be much less expensive, with a median ten-day drug-treatment cost of US$137 and $US85 for all anti-microbial agents and for anti-microbial agents excluding anti-HIV medications, respectively. The drug-treatment cost of new medications varies considerably by different therapeutic categories. This fact may influence industry decisions regarding the development of new drugs and may play a role in the shortage of new antimicrobial agents in the fight against the serious problem of antimicrobial resistance.

  16. Microbial glycolipoprotein-capped silver nanoparticles as emerging antibacterial agents against cholera.

    Science.gov (United States)

    Gahlawat, Geeta; Shikha, Sristy; Chaddha, Baldev Singh; Chaudhuri, Saumya Ray; Mayilraj, Shanmugam; Choudhury, Anirban Roy

    2016-02-01

    With the increased number of cholera outbreaks and emergence of multidrug resistance in Vibrio cholerae strains it has become necessary for the scientific community to devise and develop novel therapeutic approaches against cholera. Recent studies have indicated plausibility of therapeutic application of metal nano-materials. Among these, silver nanoparticles (AgNPs) have emerged as a potential antimicrobial agent to combat infectious diseases. At present nanoparticles are mostly produced using physical or chemical techniques which are toxic and hazardous. Thus exploitation of microbial systems could be a green eco-friendly approach for the synthesis of nanoparticles having similar or even better antimicrobial activity and biocompatibility. Hence, it would be worth to explore the possibility of utilization of microbial silver nanoparticles and their conjugates as potential novel therapeutic agent against infectious diseases like cholera. The present study attempted utilization of Ochrobactrum rhizosphaerae for the production of AgNPs and focused on investigating their role as antimicrobial agents against cholera. Later the exopolymer, purified from the culture supernatant, was used for the synthesis of spherical shaped AgNPs of around 10 nm size. Further the exopolymer was characterized as glycolipoprotein (GLP). Antibacterial activity of the novel GLP-AgNPs conjugate was evaluated by minimum inhibitory concentration, XTT reduction assay, scanning electron microscopy (SEM) and growth curve analysis. SEM studies revealed that AgNPs treatment resulted in intracellular contents leakage and cell lysis. The potential of microbially synthesized nanoparticles, as novel therapeutic agents, is still relatively less explored. In fact, the present study first time demonstrated that a glycolipoprotein secreted by the O. rhizosphaerae strain can be exploited for production of AgNPs which can further be employed to treat infectious diseases. Although this type of polymer has

  17. Molecular Therapeutic Approaches for Pediatric Acute Myeloid Leukemia

    Directory of Open Access Journals (Sweden)

    Sarah K Tasian

    2014-03-01

    Full Text Available Approximately two thirds of children with acute myeloid leukemia (AML are cured with intensive multi-agent chemotherapy. However, primary chemorefractory and relapsed AML remains a significant source of childhood cancer mortality, highlighting the need for new therapies. Further therapy intensification with traditional cytotoxic agents is not feasible given the potential for significant toxicity to normal tissues with conventional chemotherapy and the risk for long-term end-organ dysfunction. Significant emphasis has been placed upon the development of molecularly targeted therapeutic approaches for adults and children with high-risk subtypes of AML with the goal of improving remission induction and minimizing relapse. Several promising agents are currently in clinical testing or late preclinical development for AML, including monoclonal antibodies against leukemia cell surface proteins, kinase inhibitors, proteasome inhibitors, epigenetic agents, and chimeric antigen receptor engineered T cell immunotherapies. Many of these therapies have been specifically tested in children with relapsed/refractory AML via phase 1 and 2 trials with a smaller number of new agents under phase 3 evaluation for children with de novo AML. Although successful identification and implementation of new drugs for children with AML remains a formidable challenge, enthusiasm for novel molecular therapeutic approaches is great given the potential for significant clinical benefit for children who will otherwise fail standard therapy.

  18. Delayed chromosomal instability induced by DNA damage

    International Nuclear Information System (INIS)

    Morgan, W.F.; Marder, B.A.; Day, J.P.

    1994-01-01

    Cellular exposure to DNA damaging agents rapidly results in a dose dependent increase in chromosomal breakage and gross structural chromosomal rearrangements. Over recent years, evidence has been accumulating indicating genomic instability can manifest multiple generations after cellular exposure to physical and chemical DNA damaging agents. Genomic instability manifests in the progeny of surviving cells, and has been implicated in mutation, gene application, cellular transformation, and cell killing. To investigate chromosome instability following DNA damage, we have used fluorescence in situ hybridization to detect chromosomal rearrangements in a human/hamster somatic hybrid cell line following exposure to ionizing radiation. Delayed chromosomal instability was detected when multiple populations of uniquely arranged metaphases were observed in clonal isolates raised from single cells surviving X-irradiation many generations after exposure. At higher radiation doses, chromosomal instability was observed in a relatively high frequency of surviving clones and, in general, those clones showed delayed chromosome instability also showed reduced survival as measured by colony forming ability

  19. Peptides as Therapeutic Agents for Dengue Virus.

    Science.gov (United States)

    Chew, Miaw-Fang; Poh, Keat-Seong; Poh, Chit-Laa

    2017-01-01

    Dengue is an important global threat caused by dengue virus (DENV) that records an estimated 390 million infections annually. Despite the availability of CYD-TDV as a commercial vaccine, its long-term efficacy against all four dengue virus serotypes remains unsatisfactory. There is therefore an urgent need for the development of antiviral drugs for the treatment of dengue. Peptide was once a neglected choice of medical treatment but it has lately regained interest from the pharmaceutical industry following pioneering advancements in technology. In this review, the design of peptide drugs, antiviral activities and mechanisms of peptides and peptidomimetics (modified peptides) action against dengue virus are discussed. The development of peptides as inhibitors for viral entry, replication and translation is also described, with a focus on the three main targets, namely, the host cell receptors, viral structural proteins and viral non-structural proteins. The antiviral peptides designed based on these approaches may lead to the discovery of novel anti-DENV therapeutics that can treat dengue patients.

  20. Sensitization to radiation and alkylating agents by inhibitors of poly(ADP-ribose) polymerase is enhanced in cells deficient in DNA double-strand break repair.

    Science.gov (United States)

    Löser, Dana A; Shibata, Atsushi; Shibata, Akiko K; Woodbine, Lisa J; Jeggo, Penny A; Chalmers, Anthony J

    2010-06-01

    As single agents, chemical inhibitors of poly(ADP-ribose) polymerase (PARP) are nontoxic and have clinical efficacy against BRCA1- and BRCA2-deficient tumors. PARP inhibitors also enhance the cytotoxicity of ionizing radiation and alkylating agents but will only improve clinical outcomes if tumor sensitization exceeds effects on normal tissues. It is unclear how tumor DNA repair proficiency affects the degree of sensitization. We have previously shown that the radiosensitizing effect of PARP inhibition requires DNA replication and will therefore affect rapidly proliferating tumors more than normal tissues. Because many tumors exhibit defective DNA repair, we investigated the impact of double-strand break (DSB) repair integrity on the sensitizing effects of the PARP inhibitor olaparib. Sensitization to ionizing radiation and the alkylating agent methylmethane sulfonate was enhanced in DSB repair-deficient cells. In Artemis(-/-) and ATM(-/-) mouse embryo fibroblasts, sensitization was replication dependent and associated with defective repair of replication-associated damage. Radiosensitization of Ligase IV(-/-) mouse embryo fibroblasts was independent of DNA replication and is explained by inhibition of "alternative" end joining. After methylmethane sulfonate treatment, PARP inhibition promoted replication-independent accumulation of DSB, repair of which required Ligase IV. Our findings predict that the sensitizing effects of PARP inhibitors will be more pronounced in rapidly dividing and/or DNA repair defective tumors than normal tissues and show their potential to enhance the therapeutic ratio achieved by conventional DNA-damaging agents.

  1. The future of antibody therapeutics: ADCs bi-specifics and RIT

    International Nuclear Information System (INIS)

    Reichert, J.

    2015-01-01

    Full text of publication follows. Antibodies are widely accepted as remarkably versatile therapeutic agents. As evidence of this, the ∼ 30 antibody products marketed worldwide had total global sales of more than 50 billion dollars in 2012, and the commercial clinical pipeline currently comprises over 350 antibody-based product candidates. In a testament to scientific ingenuity, the investigational molecules (clinical and preclinical) are notably diverse in their composition of matter and include antibodies conjugated to a variety of agents (drugs, radioisotopes), bi-specific antibodies, and fragments or domains of antibodies. The concepts that form the basis of these agents were established decades ago, but advances in technology are now allowing new opportunities for their development. In this presentation, future directions in antibody therapeutics development will be discussed, with a focus on antibody-drug conjugates, bi-specific antibodies and radioimmunotherapy. (author)

  2. DNA Damage Signalling and Repair Inhibitors: The Long-Sought-After Achilles’ Heel of Cancer

    Directory of Open Access Journals (Sweden)

    Denis Velic

    2015-11-01

    Full Text Available For decades, radiotherapy and chemotherapy were the two only approaches exploiting DNA repair processes to fight against cancer. Nowadays, cancer therapeutics can be a major challenge when it comes to seeking personalized targeted medicine that is both effective and selective to the malignancy. Over the last decade, the discovery of new targeted therapies against DNA damage signalling and repair has offered the possibility of therapeutic improvements in oncology. In this review, we summarize the current knowledge of DNA damage signalling and repair inhibitors, their molecular and cellular effects, and future therapeutic use.

  3. Oncolytic Viruses: Therapeutics With an Identity Crisis

    Directory of Open Access Journals (Sweden)

    Caroline J. Breitbach

    2016-07-01

    Full Text Available Oncolytic viruses (OV are replicating viral therapeutics for the treatment of cancer and have been in laboratory development for about twenty years. Recently, the FDA approved Imlygic, a herpes virus based therapeutic for the treatment of melanoma and thus OVs have entered a new era where they are a weapon in the armament of the oncologist. OVs are unique therapeutics with multiple mechanisms of therapeutic activity. The exact path for their development and eventual uptake by pharmaceutical companies is somewhat clouded by an uncertain identity. Are they vaccines, tumour lysing therapeutics, inducers of innate immunity, gene therapy vectors, anti-vascular agents or all of the above? Should they be developed as stand-alone loco-regional therapeutics, systemically delivered tumour hunters or immune modulators best tested as combination therapeutics? We summarize data here supporting the idea, depending upon the virus, that OVs can be any or all of these things. Pursuing a “one-size fits all” approach is counter-productive to their clinical development and instead as a field we should build on the strengths of individual virus platforms.

  4. Vesicular (liposomal and nanoparticulated delivery of curcumin: a comparative study on carbon tetrachloride–mediated oxidative hepatocellular damage in rat model

    Directory of Open Access Journals (Sweden)

    Choudhury ST

    2016-05-01

    Full Text Available Somsubhra Thakur Choudhury,1 Nirmalendu Das,2 Swarupa Ghosh,2 Debasree Ghosh,2 Somsuta Chakraborty,2 Nahid Ali1 1Infectious Diseases and Immunology, 2Drug Development, Diagnostics and Biotechnology, CSIR-Indian Institute of Chemical Biology, Kolkata, West Bengal, India Abstract: The liver plays a vital role in biotransforming and extricating xenobiotics and is thus prone to their toxicities. Short-term administration of carbon tetrachloride (CCl4 causes hepatic inflammation by enhancing cellular reactive oxygen species (ROS level, promoting mitochondrial dysfunction, and inducing cellular apoptosis. Curcumin is well accepted for its antioxidative and anti-inflammatory properties and can be considered as an effective therapeutic agent against hepatotoxicity. However, its therapeutic efficacy is compromised due to its insolubility in water. Vesicular delivery of curcumin can address this limitation and thereby enhance its effectiveness. In this study, it was observed that both liposomal and nanoparticulated formulations of curcumin could increase its efficacy significantly against hepatotoxicity by preventing cellular oxidative stress. However, the best protection could be obtained through the polymeric nanoparticle-mediated delivery of curcumin. Mitochondria have a pivotal role in ROS homeostasis and cell survivability. Along with the maintenance of cellular ROS levels, nanoparticulated curcumin also significantly (P<0.0001 increased cellular antioxidant enzymes, averted excessive mitochondrial destruction, and prevented total liver damage in CCl4-treated rats. The therapy not only prevented cells from oxidative damage but also arrested the intrinsic apoptotic pathway. In addition, it also decreased the fatty changes in hepatocytes, centrizonal necrosis, and portal inflammation evident from the histopathological analysis. To conclude, curcumin-loaded polymeric nanoparticles are more effective in comparison to liposomal curcumin in preventing CCl4

  5. Melatonin and Its Agonist Ramelteon in Alzheimer's Disease: Possible Therapeutic Value

    Directory of Open Access Journals (Sweden)

    Venkatramanujam Srinivasan

    2011-01-01

    Full Text Available Alzheimer's disease (AD is an age-associated neurodegenerative disease characterized by the progressive loss of cognitive function, loss of memory and insomnia, and abnormal behavioral signs and symptoms. Among the various theories that have been put forth to explain the pathophysiology of AD, the oxidative stress induced by amyloid β-protein (Aβ deposition has received great attention. Studies undertaken on postmortem brain samples of AD patients have consistently shown extensive lipid, protein, and DNA oxidation. Presence of abnormal tau protein, mitochondrial dysfunction, and protein hyperphosphorylation all have been demonstrated in neural tissues of AD patients. Moreover, AD patients exhibit severe sleep/wake disturbances and insomnia and these are associated with more rapid cognitive decline and memory impairment. On this basis, the successful management of AD patients requires an ideal drug that besides antagonizing Aβ-induced neurotoxicity could also correct the disturbed sleep-wake rhythm and improve sleep quality. Melatonin is an effective chronobiotic agent and has significant neuroprotective properties preventing Aβ-induced neurotoxic effects in a number of animal experimental models. Since melatonin levels in AD patients are greatly reduced, melatonin replacement has the potential value to be used as a therapeutic agent for treating AD, particularly at the early phases of the disease and especially in those in whom the relevant melatonin receptors are intact. As sleep deprivation has been shown to produce oxidative damage, impaired mitochondrial function, neurodegenerative inflammation, and altered proteosomal processing with abnormal activation of enzymes, treatment of sleep disturbances may be a priority for arresting the progression of AD. In this context the newly introduced melatonin agonist ramelteon can be of much therapeutic value because of its highly selective action on melatonin MT1/MT2 receptors in promoting sleep.

  6. Iron-Induced Damage in Cardiomyopathy: Oxidative-Dependent and Independent Mechanisms

    Directory of Open Access Journals (Sweden)

    Elena Gammella

    2015-01-01

    Full Text Available The high incidence of cardiomyopathy in patients with hemosiderosis, particularly in transfusional iron overload, strongly indicates that iron accumulation in the heart plays a major role in the process leading to heart failure. In this context, iron-mediated generation of noxious reactive oxygen species is believed to be the most important pathogenetic mechanism determining cardiomyocyte damage, the initiating event of a pathologic progression involving apoptosis, fibrosis, and ultimately cardiac dysfunction. However, recent findings suggest that additional mechanisms involving subcellular organelles and inflammatory mediators are important factors in the development of this disease. Moreover, excess iron can amplify the cardiotoxic effect of other agents or events. Finally, subcellular misdistribution of iron within cardiomyocytes may represent an additional pathway leading to cardiac injury. Recent advances in imaging techniques and chelators development remarkably improved cardiac iron overload detection and treatment, respectively. However, increased understanding of the pathogenic mechanisms of iron overload cardiomyopathy is needed to pave the way for the development of improved therapeutic strategies.

  7. [Antiangiogenic agents in ARMD treatment].

    Science.gov (United States)

    Coroi, Mihaela-Cristiana; Demea, Sorina; Todor, Meda; Apopei, Emmanuela

    2012-01-01

    The aim of antiangiogenic agents in the treatment of age related senile macular degeneration is to destroy coroidian neoformation vessels by minimally affecting the central vision. We present a case of important central vision recovery after 3 intravitreal injections of Avastin. The therapeutic decision and patient monitoring have been made using imaging studies, such as OCT and AFG. A modern therapeutic approach of neovascular forms of age related macular degeneration, backed up by AFG and OCT is a modern treatment method of this disabling illness which brings patients optimal functional and structural improvement.

  8. Characterization of a Francisella tularensis-Caenorhabditis elegans Pathosystem for the Evaluation of Therapeutic Compounds

    OpenAIRE

    Jayamani, Elamparithi; Tharmalingam, Nagendran; Rajamuthiah, Rajmohan; Coleman, Jeffrey J.; Kim, Wooseong; Okoli, Ikechukwu; Hernandez, Ana M.; Lee, Kiho; Nau, Gerard J.; Ausubel, Frederick M.; Mylonakis, Eleftherios

    2017-01-01

    Francisella tularensis is a highly infectious Gram-negative intracellular pathogen that causes tularemia. Because of its potential as a bioterrorism agent, there is a need for new therapeutic agents. We therefore developed a whole-animal Caenorhabditis elegans-F. tularensis pathosystem for high-throughput screening to identify and characterize potential therapeutic compounds. We found that the C. elegans p38 mitogen-activate protein (MAP) kinase cascade is involved in the immune response to F...

  9. Modelling the induction of cell death and chromosome damage by therapeutic protons

    CERN Document Server

    Carante, M P

    2015-01-01

    A two-parameter biophysical model cal led BIANCA (BIophysical ANalysis of Cell death and chromosome Aberrations), which assumes a pivotal role for DNA cluster damage and for “lethal” chromosome aberrations, was applied to calculate cell death and chromosome aberrations for normal and radio-resistant cells along a 62-MeV eye melanoma proton beam. The yield of DNA “Cluster Lesions” and the probability for a chromosome fragment of not being rejoined with any partne r were adjustable parameters. In line with other works, the beam effectiveness at inducing both biological endpoints was found to increase with increasing depth, and high levels of damage were found also beyond the dose fall-off, due to the higher biological effectiveness of low-energy protons. This implies that assuming a constant RBE along the whole SOBP, as is currently done in clinical practice, may be sub-optimal, also implying a possible underestimation of normal tissue damage. Furthermore, the calculations suggested that fo...

  10. A Bayesian Belief Network Approach to Predict Damages Caused by Disturbance Agents

    Directory of Open Access Journals (Sweden)

    Alfred Radl

    2017-12-01

    Full Text Available In mountain forests of Central Europe, storm and snow breakage as well as bark beetles are the prevailing major disturbances. The complex interrelatedness between climate, disturbance agents, and forest management increases the need for an integrative approach explicitly addressing the multiple interactions between environmental changes, forest management, and disturbance agents to support forest resource managers in adaptive management. Empirical data with a comprehensive coverage for modelling the susceptibility of forests and the impact of disturbance agents are rare, thus making probabilistic models, based on expert knowledge, one of the few modelling approaches that are able to handle uncertainties due to the available information. Bayesian belief networks (BBNs are a kind of probabilistic graphical model that has become very popular to practitioners and scientists mainly due to considerations of risk and uncertainties. In this contribution, we present a development methodology to define and parameterize BBNs based on expert elicitation and approximation. We modelled storm and bark beetle disturbances agents, analyzed effects of the development methodology on model structure, and evaluated behavior with stand data from Norway spruce (Picea abies (L. Karst. forests in southern Austria. The high vulnerability of the case study area according to different disturbance agents makes it particularly suitable for testing the BBN model.

  11. Damage of Escherichia coli membrane by bactericidal agent polyhexamethylene guanidine hydrochloride: micrographic evidences.

    Science.gov (United States)

    Zhou, Z X; Wei, D F; Guan, Y; Zheng, A N; Zhong, J J

    2010-03-01

    The purpose of this study was to provide micrographic evidences for the damaged membrane structure and intracellular structure change of Escherichia coli strain 8099, induced by polyhexamethylene guanidine hydrochloride (PHMG). The bactericidal effect of PHMG on E. coli was investigated based on beta-galactosidase activity assay, fluorescein-5-isothiocyanate confocal laser scanning microscopy, field emission scanning electron microscopy and transmission electron microscopy. The results revealed that a low dose (13 microg ml(-1)) of PHMG slightly damaged the outer membrane structure of the treated bacteria and increased the permeability of the cytoplasmic membrane, while no significant damage was observed to the morphological structure of the cells. A high dose (23 microg ml(-1)) of PHMG collapsed the outer membrane structure, led to the formation of a local membrane pore across the membrane and badly damaged the internal structure of the cells. Subsequently, intracellular components were leaked followed by cell inactivation. Dose-dependent membrane disruption was the main bactericidal mechanism of PHMG. The formation of the local membrane pores was probable after exposure to a high dose (23 microg ml(-1)) of PHMG. Micrographic evidences were provided about the damaged membrane structure and intracellular structure change of E. coli. The presented information helps understand the bactericidal mechanism of PHMG by membrane damage.

  12. Therapeutic Effect of Novel Single-Stranded RNAi Agent Targeting Periostin in Eyes with Retinal Neovascularization

    Directory of Open Access Journals (Sweden)

    Takahito Nakama

    2017-03-01

    Full Text Available Retinal neovascularization (NV due to retinal ischemia remains one of the principal causes of vision impairment in patients with ischemic retinal diseases. We recently reported that periostin (POSTN may play a role in the development of preretinal fibrovascular membranes, but its role in retinal NV has not been determined. The purpose of this study was to examine the expression of POSTN in the ischemic retinas of a mouse model of oxygen-induced retinal NV. We also studied the function of POSTN on retinal NV using Postn KO mice and human retinal endothelial cells (HRECs in culture. In addition, we used a novel RNAi agent, NK0144, which targets POSTN to determine its effect on the development of retinal NV. Our results showed that the expression of POSTN was increased in the vascular endothelial cells, pericytes, and M2 macrophages in ischemic retinas. POSTN promoted the ischemia-induced retinal NV by Akt phosphorylation through integrin αvβ3. NK0144 had a greater inhibitory effect than canonical double-stranded siRNA on preretinal pathological NV in vivo and in vitro. These findings suggest a causal relationship between POSTN and retinal NV, and indicate a potential therapeutic role of intravitreal injection of NK0144 for retinal neovascular diseases.

  13. Multiwalled carbon nanotube hybrids as MRI contrast agents

    Directory of Open Access Journals (Sweden)

    Nikodem Kuźnik

    2016-07-01

    Full Text Available Magnetic resonance imaging (MRI is one of the most commonly used tomography techniques in medical diagnosis due to the non-invasive character, the high spatial resolution and the possibility of soft tissue imaging. Contrast agents, such as gadolinium complexes and superparamagnetic iron oxides, are administered to spotlight certain organs and their pathologies. Many new models have been proposed that reduce side effects and required doses of these already clinically approved contrast agents. These new candidates often possess additional functionalities, e.g., the possibility of bioactivation upon action of particular stimuli, thus serving as smart molecular probes, or the coupling with therapeutic agents and therefore combining both a diagnostic and therapeutic role. Nanomaterials have been found to be an excellent scaffold for contrast agents, among which carbon nanotubes offer vast possibilities. The morphology of multiwalled carbon nanotubes (MWCNTs, their magnetic and electronic properties, the possibility of different functionalization and the potential to penetrate cell membranes result in a unique and very attractive candidate for a new MRI contrast agent. In this review we describe the different issues connected with MWCNT hybrids designed for MRI contrast agents, i.e., their synthesis and magnetic and dispersion properties, as well as both in vitro and in vivo behavior, which is important for diagnostic purposes. An introduction to MRI contrast agent theory is elaborated here in order to point to the specific expectations regarding nanomaterials. Finally, we propose a promising, general model of MWCNTs as MRI contrast agent candidates based on the studies presented here and supported by appropriate theories.

  14. Ivacaftor: A Novel Gene-Based Therapeutic Approach for Cystic Fibrosis

    OpenAIRE

    Condren, Michelle E.; Bradshaw, Marquita D.

    2013-01-01

    Ivacaftor is a new therapeutic agent that acts at the cystic fibrosis transmembrane conductance regulator (CFTR) channel to alter activity. It is approved for use in patients 6 years and older with cystic fibrosis who have at least 1 G551D mutation in the CFTR gene. It is unlike any other current pharmacologic agent for cystic fibrosis in that it specifically targets the gene defect associated with cystic fibrosis as opposed to treating resulting symptomology. Mucoactive agents, antibiotics, ...

  15. Evaluation of real-time data obtained from gravimetric preparation of antineoplastic agents shows medication errors with possible critical therapeutic impact: Results of a large-scale, multicentre, multinational, retrospective study.

    Science.gov (United States)

    Terkola, R; Czejka, M; Bérubé, J

    2017-08-01

    Medication errors are a significant cause of morbidity and mortality especially with antineoplastic drugs, owing to their narrow therapeutic index. Gravimetric workflow software systems have the potential to reduce volumetric errors during intravenous antineoplastic drug preparation which may occur when verification is reliant on visual inspection. Our aim was to detect medication errors with possible critical therapeutic impact as determined by the rate of prevented medication errors in chemotherapy compounding after implementation of gravimetric measurement. A large-scale, retrospective analysis of data was carried out, related to medication errors identified during preparation of antineoplastic drugs in 10 pharmacy services ("centres") in five European countries following the introduction of an intravenous workflow software gravimetric system. Errors were defined as errors in dose volumes outside tolerance levels, identified during weighing stages of preparation of chemotherapy solutions which would not otherwise have been detected by conventional visual inspection. The gravimetric system detected that 7.89% of the 759 060 doses of antineoplastic drugs prepared at participating centres between July 2011 and October 2015 had error levels outside the accepted tolerance range set by individual centres, and prevented these doses from reaching patients. The proportion of antineoplastic preparations with deviations >10% ranged from 0.49% to 5.04% across sites, with a mean of 2.25%. The proportion of preparations with deviations >20% ranged from 0.21% to 1.27% across sites, with a mean of 0.71%. There was considerable variation in error levels for different antineoplastic agents. Introduction of a gravimetric preparation system for antineoplastic agents detected and prevented dosing errors which would not have been recognized with traditional methods and could have resulted in toxicity or suboptimal therapeutic outcomes for patients undergoing anticancer treatment.

  16. New therapeutic agent for radiation synovectomy - preparation of {sup 166}Ho-EDTMP-HA particle

    Energy Technology Data Exchange (ETDEWEB)

    Bai, H.; Jin, X.; Du, J.; Wang, F.; Chen, D.; Fan, H.; Cheng, Z.; Zhang, J. [China Institute of Atomic Energy, Beijing (Switzerland). Isotope Department

    1997-10-01

    In order to prepare new therapeutical agent for radiation synovectomy, Hydroxyapatite (HA) was labelled with {sup 166}Ho by EDTMP that had high affinity to HA particles. Radiolabelling of HA particles was divided into two steps, {sup 166}Ho-EDTMP was prepared first; then mixed with HA particles completely and vibrated for 15 minutes on the micromixer at room temperature, washed 3 times with deionized water. Radiolabelling particle was separated from free {sup 166}Ho via centrifugation to determine its radiolabelling efficiency. {sup 166}Ho-EDTMP-HA and {sup 166}Ho-EDTMP were injected into knee joint of normal rabbits respectively, every group was killed at different time postinjection, took out major organ and collected urine and blood, then weighted and determined their radio counts. HA particles, as a natural component of bone was known to have good compatibility with soft tissue and biodegrade into calcium and phosphate in vivo. It was readily prepared from common chemical and formed into particles of desired size range in a controlled process, it had high stability in vitro and vivo. Radiolabelling of HA particle with {sup 166}Ho by EDTMP was simple to perform and provides an excellent labelling yield that was more than 95% under the optimal labelling condition. The optimal labelling condition at room temperature was pH 6.0-8.0 and vibration time 15 minutes. The absorbed capacity of HA particle was 5 mg Ho/g HA particle and size of radiolabelling particle was at range of 2-5,{mu}m that is suitable for therapy of radiation synovectomy. {sup 166}Ho-EDTMP-HA particle demonstrated high in vitro stability in either normal saline or 1% BSA solution, but instability under extremely acidic condition (pH 1-2). The control studies performed with {sup 166}Ho-EDTMP not bound to HA particle provided information on the distribution of radioactivity that would occur upon leakage of the radiochemical compound from joint. Its short half-life, its extremely low leakage from the

  17. Resveratrol as a Therapeutic Agent for Alzheimer's Disease

    Science.gov (United States)

    Ma, Teng; Tan, Meng-Shan; Yu, Jin-Tai; Tan, Lan

    2014-01-01

    Alzheimer's disease (AD) is the most common cause of dementia, but there is no effective therapy till now. The pathogenic mechanisms of AD are considerably complex, including Aβ accumulation, tau protein phosphorylation, oxidative stress, and inflammation. Exactly, resveratrol, a polyphenol in red wine and many plants, is indicated to show the neuroprotective effect on mechanisms mostly above. Recent years, there are numerous researches about resveratrol acting on AD in many models, both in vitro and in vivo. However, the effects of resveratrol are limited by its pool bioavailability; therefore researchers have been trying a variety of methods to improve the efficiency. This review summarizes the recent studies in cell cultures and animal models, mainly discusses the molecular mechanisms of the neuroprotective effects of resveratrol, and thus investigates the therapeutic potential in AD. PMID:25525597

  18. Barnase as a new therapeutic agent triggering apoptosis in human cancer cells.

    Directory of Open Access Journals (Sweden)

    Evelina Edelweiss

    Full Text Available BACKGROUND: RNases are currently studied as non-mutagenic alternatives to the harmful DNA-damaging anticancer drugs commonly used in clinical practice. Many mammalian RNases are not potent toxins due to the strong inhibition by ribonuclease inhibitor (RI presented in the cytoplasm of mammalian cells. METHODOLOGY/PRINCIPAL FINDINGS: In search of new effective anticancer RNases we studied the effects of barnase, a ribonuclease from Bacillus amyloliquefaciens, on human cancer cells. We found that barnase is resistant to RI. In MTT cell viability assay, barnase was cytotoxic to human carcinoma cell lines with half-inhibitory concentrations (IC(50 ranging from 0.2 to 13 microM and to leukemia cell lines with IC(50 values ranging from 2.4 to 82 microM. Also, we characterized the cytotoxic effects of barnase-based immunoRNase scFv 4D5-dibarnase, which consists of two barnase molecules serially fused to the single-chain variable fragment (scFv of humanized antibody 4D5 that recognizes the extracellular domain of cancer marker HER2. The scFv 4D5-dibarnase specifically bound to HER2-positive cells and was internalized via receptor-mediated endocytosis. The intracellular localization of internalized scFv 4D5-dibarnase was determined by electronic microscopy. The cytotoxic effect of scFv 4D5-dibarnase on HER2-positive human ovarian carcinoma SKOV-3 cells (IC(50 = 1.8 nM was three orders of magnitude greater than that of barnase alone. Both barnase and scFv 4D5-dibarnase induced apoptosis in SKOV-3 cells accompanied by internucleosomal chromatin fragmentation, membrane blebbing, the appearance of phosphatidylserine on the outer leaflet of the plasma membrane, and the activation of caspase-3. CONCLUSIONS/SIGNIFICANCE: These results demonstrate that barnase is a potent toxic agent for targeting to cancer cells.

  19. DNA repair in mammalian cells exposed to combinations of carcinogenic agents

    International Nuclear Information System (INIS)

    Setlow, R.B.; Ahmed, F.E.

    1979-01-01

    Cells defective in one or more aspects of repair are killed and often mutagenized more readily than normal cells by DNA damaging agents, and humans whose cells are deficient in repair are at an increased carcinogenic risk compared to normal individuals. The excision repair of uv induced pyrimidine dimers is a well studied system, but the details of the steps in this repair system are far from being understood in human cells. We know that there are a number of chemicals that mimic uv in that normal human cells repair DNA damage from both these agents and from uv by a long patch excision repair system, and that xeroderma pigmentosum cells defective in repair of uv are also defective in the repair of damage from these chemicals. The chemicals we have investigated are AAAF, 4-NQO, DMBA-epoxide, and ICR-170. We describe experiments, using several techniques, in which DNA excision repair is measured after treatment of various human cell strains with combinations of uv and these agents. If two agents have a common rate limiting step then, at doses high enough to saturate the repair system, one would expect the observed repair after a treatment with a combination of agents to be equal to that from one agent alone. Such is not the case for normal human or excision-deficient XP cells. In the former repair is additive and in the latter repair is usually appreciably less than that observed with either agent alone. Models that attempt to explain these surprising results involve complexes of enzymes and cofactors

  20. DNA-damage-inducible (din) loci are transcriptionally activated in competent Bacillus subtilis

    International Nuclear Information System (INIS)

    Love, P.E.; Lyle, M.J.; Yasbin, R.E.

    1985-01-01

    DNA damage-inducible (din) operon fusions were generated in Bacillus subtilis by transpositional mutagenesis. These YB886(din::Tn917-lacZ) fusion isolates produced increased β-galactosidase when exposed to mitomycin C, UV radiation, or ethyl methanesulfonate, indicating that the lacZ structural gene had inserted into host transcriptional units that are induced by a variety of DNA-damaging agents. One of the fusion strains was DNA-repair deficient and phenotypically resembled a UV-sensitive mutant of B. subtilis. Induction of β-galactosidase also occurred in the competent subpopulation of each of the din fusion strains, independent of exposure to DNA-damaging agents. Both the DNA-damage-inducible and competence-inducible components of β-galactosidase expression were abolished by the recE4 mutation, which inhibits SOS-like (SOB) induction but does not interfere with the development of the component state. The results indicate that gene expression is stimulated at specific loci within the B. subtilis chromosome both by DNA-damaging agents and by the development of competence and that this response is under the control of the SOB regulatory system. Furthermore, they demonstrate that at the molecular level SOB induction and the development of competence are interrelated cellular events

  1. A psychodynamic model of behavior after acute central nervous system damage.

    Science.gov (United States)

    Groswasser, Z; Stern, M J

    1998-02-01

    This article describes a conceptual psychodynamic model for understanding the neurobehavioral manifestations of acute central nervous system damage (ACNSD) displayed by patients during the rehabilitation process. According to the proposed model, patientsO behavioral responses are viewed as their only means of emotional expression and therefore may not be considered entirely abnormal when viewed from the perspective of patientsO interpersonal contexts. An improved understanding of the dynamic processes through which recovering patients with ACNSD journey may lead to better interaction between the patient and the therapeutic environment, the interdisciplinary team, and family members. Combining this proposed psychodynamic model with an emerging understanding of the neurobehavioral foundations of aggression and depression may also lead to a more rational approach to intervention with various psychopharmacologic agents. During the rehabilitation process, understanding patients' cognitive deficits, motivational drives, and emotional needs and proper implementation of medical and environmental treatment can ultimately lead to a better psychosocial outcome.

  2. Heat-resistant agent used for control sand of steam huff and puff heavy oil well

    Science.gov (United States)

    Zhang, F. S.; Liu, G. L.; Lu, Y. J.; Xiong, X. C.; Ma, J. H.; Su, H. M.

    2018-01-01

    Heat-resistant agent containing hydroxymethyl group was synthesized from coal tar, which has similar structure with phenolic resin and could improve the heat resistance of phenolic resin sand control agent. The results showed that the heat resistance of the sand control agent was improved by adding 10% to 30% heat-resistant agent, after 280°C high temperature treatment for 7d, the compressive strength of consolidated core was increased to more than 5MPa. The compressive strength of consolidation core was not decreased after immersion in formation water, crude oil, acid or alkaline medium, which showed good resistance to medium immersion. The sand control agent had small core damage and the core permeability damage ratio of sand control agent consolidation was only 18.7%.

  3. Tumor angiogenesis--a new therapeutic target in gliomas

    DEFF Research Database (Denmark)

    Lund, E L; Spang-Thomsen, M; Skovgaard-Poulsen, H

    1998-01-01

    significant angiogenic activity primarily by the expression of the angiogenic factor VEGF Anti-angiogenic therapy represents a new promising therapeutic modality in solid tumors. Several agents are currently under evaluation in clinical trials. The present review describes the principal inducers...

  4. Imaging findings and therapeutic alternatives for peripheral vascular malformations

    International Nuclear Information System (INIS)

    Monsignore, Lucas Moretti; Nakiri, Guilherme Seizem; Santos, Daniela dos; Abud, Thiago Giansante; Abud, Daniel Giansante

    2010-01-01

    Peripheral vascular malformations represent a spectrum of lesions that appear through the lifetime and can be found in the whole body. Such lesions are uncommon and are frequently confounded with infantile hemangioma, a common benign neoplastic lesion. In the presence of such lesions, the correlation between the clinical and radiological findings is extremely important to achieve a correct diagnosis, which will guide the best therapeutic approach. The most recent classifications for peripheral vascular malformations are based on the blood flow (low or high) and on the main vascular components (arterial, capillary, lymphatic or venous). Peripheral vascular malformations represent a diagnostic and therapeutic challenge, and complementary methods such as computed tomography, Doppler ultrasonography and magnetic resonance imaging, in association with clinical findings can provide information regarding blood flow characteristics and lesions extent. Arteriography and venography confirm the diagnosis, evaluate the lesions extent and guide the therapeutic decision making. Generally, low flow vascular malformations are percutaneously treated with sclerosing agents injection, while in high flow lesions the approach is endovascular, with permanent liquid or solid embolization agents. (author)

  5. Melatonin and Nitrones As Potential Therapeutic Agents for Stroke

    Directory of Open Access Journals (Sweden)

    Alejandro Romero

    2016-11-01

    Full Text Available Stroke is a disease of aging affecting millions of people worldwide, and recombinant tissue-type plasminogen activator (r-tPA is the only treatment approved. However, r-tPA has a low therapeutic window and secondary effects which limit its beneficial outcome, urging thus the search for new more efficient therapies. Among them, neuroprotection based on melatonin or nitrones, as free radical traps, have arisen as drug candidates due to their strong antioxidant power. In this Perspective article, an update on the specific results of the melatonin and several new nitrones are presented.

  6. Research Progress in the Modification of Quercetin Leading to Anticancer Agents

    Directory of Open Access Journals (Sweden)

    Alessandro Massi

    2017-07-01

    Full Text Available The flavonoid quercetin (3,3′,4′,5,7-pentahydroxyflavone is widely distributed in plants, foods, and beverages. This polyphenol compound exhibits varied biological actions such as antioxidant, radical-scavenging, anti-inflammatory, antibacterial, antiviral, gastroprotective, immune-modulator, and finds also application in the treatment of obesity, cardiovascular diseases and diabetes. Besides, quercetin can prevent neurological disorders and exerts protection against mitochondrial damages. Various in vitro studies have assessed the anticancer effects of quercetin, although there are no conclusive data regarding its mode of action. However, low bioavailability, poor aqueous solubility as well as rapid body clearance, fast metabolism and enzymatic degradation hamper the use of quercetin as therapeutic agent, so intense research efforts have been focused on the modification of the quercetin scaffold to obtain analogs with potentially improved properties for clinical applications. This review gives an overview of the developments in the synthesis and anticancer-related activities of quercetin derivatives reported from 2012 to 2016.

  7. Limited-Sampling Strategies for Therapeutic Drug Monitoring of Moxifloxacin in Patients With Tuberculosis

    NARCIS (Netherlands)

    Pranger, Arianna D.; Kosterink, Jos G. W.; van Altena, Richard; Aarnoutse, Rob E.; van der Werf, Tjip S.; Uges, Donald R. A.; Alffenaar, Jan-Willem C.

    Background: Moxifloxacin (MFX) is a potent drug for multidrug resistant tuberculosis(TB) treatment and is also useful if first-line agents are not tolerated. Therapeutic drug monitoring may help to prevent treatment failure. Obtaining a full concentration-time curve of MFX for therapeutic drug

  8. Limited-sampling strategies for therapeutic drug monitoring of moxifloxacin in patients with tuberculosis

    NARCIS (Netherlands)

    Pranger, A.D.; Kosterink, J.G.W.; Altena, R. van; Aarnoutse, R.E.; Werf, T.S. van der; Uges, D.R.A.; Alffenaar, J.W.C.

    2011-01-01

    BACKGROUND: Moxifloxacin (MFX) is a potent drug for multidrug resistant tuberculosis(TB) treatment and is also useful if first-line agents are not tolerated. Therapeutic drug monitoring may help to prevent treatment failure. Obtaining a full concentration-time curve of MFX for therapeutic drug

  9. The influence of AT1002 on the nasal absorption of molecular weight markers and therapeutic agents when co-administered with bioadhesive polymers and an AT1002 antagonist, AT1001.

    Science.gov (United States)

    Song, Keon-Hyoung; Eddington, Natalie D

    2012-01-01

    The purpose of this study was to demonstrate the effects of the tight junction permeation enhancer, AT1002, on the nasal absorption of molecular weight markers and low bioavailable therapeutic agents co-administered with bioadhesive polymers or zonulin antagonist. The bioadhesive polymers, carrageenan and Na-CMC, were prepared with AT1002 to examine the permeation-enhancing effect of AT1002 on the nasal absorption of inulin, calcitonin and saquinavir after nasal administration to Sprague-Dawley rats. Blood samples were collected over a 6-hour period from a jugular cannula. In addition, we determined whether AT1002 exerts a permeation-enhancing effect via activation of PAR-2 specific binding to a putative receptor of zonulin. To examine this zonulin antagonist, AT1001, was administered 30 min prior to dosing with an AT1002/inulin solution and blood samples were collected over a 6-hour period. The bioadhesive polymers did not directly increase the absorption of inulin, calcitonin and saquinavir, but promoted the permeation-enhancing effect of AT1002 when delivered nasally, thereby significantly increasing the absorption of each drug. Pre-treatment with AT1001 antagonized the zonulin receptor and significantly minimized the permeation-enhancing effect of AT1002. These findings will assist in understanding the permeation-enhancing capability of and the receptor binding of AT1002. Further, combining AT1002 with carrageenan supports the development of the mucosal delivery of therapeutic agents that have low bioavailability even with bioadhesive agents. © 2011 The Authors. JPP © 2011 Royal Pharmaceutical Society.

  10. Meeting Report: High-Throughput Technologies for In Vivo Imaging Agents

    Directory of Open Access Journals (Sweden)

    Robert J. Gillies

    2005-04-01

    Full Text Available Combinatorial chemistry and high-throughput screening have become standard tools for discovering new drug candidates with suitable pharmacological properties. Now, those same technologies are starting to be applied to the problem of discovering novel in vivo imaging agents. Important differences in the biological and pharmacological properties needed for imaging agents, compared to those for a therapeutic agent, require new screening methods that emphasize those characteristics, such as optimized residence time and tissue specificity, that make for a good imaging agent candidate.

  11. Cisplatin impairs rat liver mitochondrial functions by inducing changes on membrane ion permeability: Prevention by thiol group protecting agents

    International Nuclear Information System (INIS)

    Custodio, Jose B.A.; Cardoso, Carla M.P.; Santos, Maria S.; Almeida, Leonor M.; Vicente, Joaquim A.F.; Fernandes, Maria A.S.

    2009-01-01

    H + ; (3) does not significantly affect H 2 O 2 generation by mitochondria; (4) its mitochondrial damaging effects are protected by thiol group protecting agents. Based on these conclusions, it is possible to hypothesise that small changes on the redox-status of thiol groups, affecting membrane permeability to cations (Ca 2+ and H + ) underlie CisPt-induced liver mitochondrial damage, putatively responsible for its hepatotoxicity. Therefore, we propose that CisPt-induced mitochondrial damage and consequent hepatotoxicity could be prevented by using thiol group protecting agents as therapeutic adjuvants.

  12. Multi-targeting Andrographolide and its Natural Analogs as Potential Therapeutic Agents.

    Science.gov (United States)

    Kishore, V; Yarla, Nagendra Sastry; Bishayee, Anupam; Putta, Swathi; Malla, Ramarao; Neelapu, Nageswara Rao Reddy; Challa, Surekha; Das, Subhasish; Shiralgi, Yallappa; Hegde, Gurumurthy; Dhananjaya, Bhadrapura Lakkappa

    2017-01-01

    Andrographis paniculata (A. paniculata) is a medicinal plant used in the Indian and Chinese traditional medicinal systems for its various beneficial properties of therapeutics. This is due to the presence of a diterpene lactone called 'andrographolide'. Several biological activities like antiinflammatory, antitumour, anti-hyperglycaemic, anti-fertility, antiviral, cardio protective and hepatoprotective properties are attributed to andrographolide and its natural analogs. The studies have shown that not only this diterpene lactone (andrographolide), but also other related terpenoid analogs from A. paniculata could be exploited for disease prevention due to their structural similarity with diverse pharmacological activities. Several scientific groups are trying to unveil the underlying mechanisms involved in these biological actions brough aout by andrographolide and its analogs. This review aims at giving an overview on the therapeutical and/or pharmacological activities of andrographolide and its derivatives and also exemplify the underlying mechanisms involved. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  13. Trend of research and development on clearance system for CBRNE agents

    International Nuclear Information System (INIS)

    Ishihara, Masayuki; Fujita, Masanori; Ishida, Natsuko; Hattori, Hidemi; Tachibana, Shoich; Nakamura, Shingo; Kanatani, Yasuhiro

    2013-01-01

    In a field of disaster for a wide variety of Chemical, Biological, Radiological, Nuclear, Explosive (CBRNE) agents which are harmful and deadly poisonous, it is crucial to effectively clear those agents for prevention of expanded damages and retrieval from damage. The clearance technologies in the CBRNE disaster field require to be safe for human body and to be friendly for the environments. In addition, they need scientific data-based evidences for their effectiveness and safety. The aim of this article is to view the trend of research on clearances of N, B and c agents in terms of rapidity, simplicity and economic rationality, and to deliberate on effective clearance system using adequate equipments and materials for detoxification, decomposition and removal of each contamination. (author)

  14. Immunological effects of hypomethylating agents.

    Science.gov (United States)

    Lindblad, Katherine E; Goswami, Meghali; Hourigan, Christopher S; Oetjen, Karolyn A

    2017-08-01

    Epigenetic changes resulting from aberrant methylation patterns are a recurrent observation in hematologic malignancies. Hypomethylating agents have a well-established role in the management of patients with high-risk myelodysplastic syndrome or acute myeloid leukemia. In addition to the direct effects of hypomethylating agents on cancer cells, there are several lines of evidence indicating a role for immune-mediated anti-tumor benefits from hypomethylating therapy. Areas covered: We reviewed the clinical and basic science literature for the effects of hypomethylating agents, including the most commonly utilized therapeutics azacitidine and decitabine, on immune cell subsets. We summarized the effects of hypomethylating agents on the frequency and function of natural killer cells, T cells, and dendritic cells. In particular, we highlight the effects of hypomethylating agents on expression of immune checkpoint inhibitors, leukemia-associated antigens, and endogenous retroviral elements. Expert commentary: In vitro and ex vivo studies indicate mixed effects on the function of natural killer, dendritic cells and T cells following treatment with hypomethylating agents. Clinical correlates of immune function have suggested that hypomethylating agents have immunomodulatory functions with the potential to synergize with immune checkpoint therapy for the treatment of hematologic malignancy, and has become an active area of clinical research.

  15. Phenolic antioxidants attenuate hippocampal neuronal cell damage ...

    Indian Academy of Sciences (India)

    Unknown

    CP had lower Fe3+ reducing activity in comparison to WS and AV. Plant extracts given singly ... modulators of nervous system damage. In epilepsy, ex- ..... D 1978 Antimicrobial agents from higher plants, Glycy- rrhiza glabra L. I. Some ...

  16. Contrast Agent in Magnetic Resonance Imaging

    DEFF Research Database (Denmark)

    Vu-Quang, Hieu

    2015-01-01

    Nanoparticles have been employed as contrast agent in magnetic resonance imaging (MRI) in order to improve sensitivity and accuracy in diagnosis. In addition, these contrast agents are potentially combined with other therapeutic compounds or near infrared bio-imaging (NIR) fluorophores to obtain...... theranostic or dual imaging purposes, respectively. There were two main types of MRI contrast agent that were synthesized during this PhD project including fluorine containing nanoparticles and magnetic nanoparticles. In regard of fluorine containing nanoparticles, there were two types contrast agent...... cancer cells for cancer diagnosis in MRI. F127-Folate coated SPION were stable in various types of suspension medium for over six months. They could specifically target folate receptor of cancer cells in vitro and in vivo thus enhancing the contrast in MRI T2/T2* weighted images. These are preliminary...

  17. Therapeutic effect of recombinant human interleukin-11 and curcumin on jejunal damage in mice after neutron irradiation

    International Nuclear Information System (INIS)

    Chang Gongmin; Peng Ruiyun; Gao Yabing; Wang Shuiming; Li Yang; Xu Xinping; Wang Lifeng; Dong Ji; Zhao Li

    2010-01-01

    Objective: To explore the therapeutic effect of recombinant human interleukin (rhIL-11) and curcumin on jejunal damage in mice after neutron irradiation. Methods: 140 male BALB/c mice were randomly divided into 4 groups: 20 mice in healthy control group, 60 mice in mere irradiation group, 30 mice in IL-11 treatment group and 30 mice in curcumin treatment group. The mere irradiation group mice were wholly exposed to 3 Gy neutron irradiation. The treatment groups mice were imtraperitoneally injected with rhIL-11 at the dosage of 500 μg·kg -1 ·d -1 and ourcumin of 200 mg·kg -1 ·/ -1 through enterocoelia once a day for a d after irradiation. The mortality of the mice were observed. The mice in the control and mere irradiation groups were killed 6 h, 1, 3, and 6 d post-irradiation, respectively, and the mice of the 2 treatment groups were killed 3 and 6 d post-irradiation, respectively and the samples of jujunum were colleted. HE staining, argyrophilic of nucleolar organizer staining, Feulgen staining, and image analysis were used to observe the pathology and levels of argyrophilic proteins and DNA. Results: The mice in the mere irradiation group all died at 5 d post-irradiation, while 2 mice in the IL-11 treatment group and 3 in the curcumin group survived. Large area necrosis and exfoliation were found in the intestinal epithelial mucosa of the mere irradiated group mice since 6 h to 3 d after irradiation. Crypt cell regeneration was seen occasionally found 3 days later and much more 5 days later. Crypt cell regeneration was obviously found in the intestinal epithelial mucosa and lots of new villi were observed 5 d after irradiation in both treatment groups, however, the amounts of crypt cells and new villi of the curcumin treatment group were less than those of the IL-11 treatment group. The contents of AgNOR and DNA in the intestinal epithelial cells 5 days after irradiation of the 2 treatment groups were all significantly higher than those of the mere

  18. Implication of fractionated dose exposures in therapeutic gain

    International Nuclear Information System (INIS)

    Kim, Hye-Jin; Lee, Min-Ho; Kim, Eun-Hee

    2016-01-01

    Radiation therapy pursues killing tumor cells while sparing normal cells from the radiation exposure. Stereotactic radiosurgery (SRS) is a cancer treatment modality that delivers a high dose in a single operation. This high-dose single operation shortens the treatment course, but can increase the risk of normal cell damage. Normal cell damage can be reduced by employing multi-directional exposures for an increasing number of isocenters. In this study, we investigated whether therapeutic benefits would be expected by employing new dose fractionation patterns at a high-dose single operation. The conventional single-dose operation in brain tumor radiosurgery is performed by delivering fractionated uniform doses. According to Figs. 2 and 3, the conventional radiosurgery might have obtained some therapeutic benefit by employing the fractionated uniform-dose exposures instead of a single-dose exposure. We suggest that further therapeutic gain be expected by employing the fractionated radiation exposures in an increasing dose pattern. Until ensuring our suggestion, the significance in gain of cell surviving should be verified for all three dose patterns with both normal and tumor cells. The investigation whether normal and tumor cells show the same responses to the fractionated dose exposures at lower and higher than 15 Gy of total dose is also reserved for future work

  19. [Biological agents].

    Science.gov (United States)

    Amano, Koichi

    2009-03-01

    There are two types of biological agents for the treatment of rheumatoid arthritis (RA); monoclonal antibodies and recombinant proteins. Among the latter, etanercept, a recombinant fusion protein of soluble TNF receptor and IgG was approved in 2005 in Japan. The post-marketing surveillance of 13,894 RA patients revealed the efficacy and safety profiles of etanercept in the Japanese population, as well as overseas studies. Abatacept, a recombinant fusion protein of CTLA4 and IgG, is another biological agent for RA. Two clinical trials disclosed the efficacy of abatacept for difficult-to-treat patients: the AIM for MTX-resistant cases and the ATTAIN for patients who are resistant to anti-TNF. The ATTEST trial suggested abatacept might have more acceptable safety profile than infliximab. These biologics are also promising for the treatment of RA for not only relieving clinical symptoms and signs but retarding structural damage.

  20. Pathogenic inflammation and its therapeutic targeting in systemic lupus erythematosus

    Directory of Open Access Journals (Sweden)

    Timothy Andrew Gottschalk

    2015-10-01

    Full Text Available Systemic Lupus Erythematosus (SLE, lupus is a highly complex and heterogeneous autoimmune disease that most often afflicts women in their child-bearing years. It is characterized by circulating self-reactive antibodies that deposit in tissues including skin, kidneys and brain, and the ensuing inflammatory response can lead to irreparable tissue damage. Over many years, clinical trials in SLE have focused on agents that control B and T lymphocyte activation, and, with the single exception of an agent known as Belimumab which targets the B cell survival factor BAFF, they have been disappointing. At present, standard therapy for SLE with mild disease is the agent hydroxychloroquine. During disease flares, steroids are often used, while the more severe manifestations with major organ involvement warrant potent, broad-spectrum immuno-suppression with cyclophosphamide or mycophenolate. Current treatments have severe and dose-limiting toxicities and thus a more specific therapy targeting a causative factor or signaling pathway would be greatly beneficial in SLE treatment. Moreover, the ability to control inflammation alongside B cell activation may be a superior approach for disease control. There has been a recent focus on the innate immune system and associated inflammation, which has uncovered key players in driving the pathogenesis of SLE. Delineating some of these intricate inflammatory mechanisms has been possible with studies using spontaneous mouse mutants and genetically engineered mice. These strains, to varying degrees, exhibit hallmarks of the human disease and therefore have been utilized to model human SLE and to test new drugs. Developing a better understanding of the initiation and perpetuation of disease in SLE may uncover suitable novel targets for therapeutic intervention. Here we discuss the involvement of inflammation in SLE disease pathogenesis, with a focus on several key proinflammatory cytokines and myeloid growth factors, and

  1. Pathogenic Inflammation and Its Therapeutic Targeting in Systemic Lupus Erythematosus

    Science.gov (United States)

    Gottschalk, Timothy A.; Tsantikos, Evelyn; Hibbs, Margaret L.

    2015-01-01

    Systemic lupus erythematosus (SLE, lupus) is a highly complex and heterogeneous autoimmune disease that most often afflicts women in their child-bearing years. It is characterized by circulating self-reactive antibodies that deposit in tissues, including skin, kidneys, and brain, and the ensuing inflammatory response can lead to irreparable tissue damage. Over many years, clinical trials in SLE have focused on agents that control B- and T-lymphocyte activation, and, with the single exception of an agent known as belimumab which targets the B-cell survival factor BAFF, they have been disappointing. At present, standard therapy for SLE with mild disease is the agent hydroxychloroquine. During disease flares, steroids are often used, while the more severe manifestations with major organ involvement warrant potent, broad-spectrum immunosuppression with cyclophosphamide or mycophenolate. Current treatments have severe and dose-limiting toxicities and thus a more specific therapy targeting a causative factor or signaling pathway would be greatly beneficial in SLE treatment. Moreover, the ability to control inflammation alongside B-cell activation may be a superior approach for disease control. There has been a recent focus on the innate immune system and associated inflammation, which has uncovered key players in driving the pathogenesis of SLE. Delineating some of these intricate inflammatory mechanisms has been possible with studies using spontaneous mouse mutants and genetically engineered mice. These strains, to varying degrees, exhibit hallmarks of the human disease and therefore have been utilized to model human SLE and to test new drugs. Developing a better understanding of the initiation and perpetuation of disease in SLE may uncover suitable novel targets for therapeutic intervention. Here, we discuss the involvement of inflammation in SLE disease pathogenesis, with a focus on several key proinflammatory cytokines and myeloid growth factors, and review the known

  2. Molecular pathways involved in the early and late damage induced by testis ischemia: evidence for a rational pharmacological modulation.

    Science.gov (United States)

    Altavilla, D; Romeo, C; Squadrito, F; Marini, H; Morgia, G; Antonuccio, P; Minutoli, L

    2012-01-01

    Testicular torsion or torsion of the spermatic cord is a surgical emergency in which misdiagnosis and inappropriate treatment can lead to male infertility. Events occurring during testicular torsion and detorsion are representative of an ischemia-reperfusion injury observed in other organs. The two most important factors determining testicular damage are the degree of twisting and the early onset of a surgical treatment to counter-rotate both testis and spermatic cord for inducing reperfusion. The damage from reperfusion is more severe than that induced by ischemia and several mechanisms are implicated in the development of testicular damage following torsion and detorsion. However, these mechanisms have not yet been fully clarified and, as a consequence, there is still a strong need to identify specific pharmacological treatment to limit the damage triggered by the reperfusion procedures. Ischemia and reperfusion of testis result in elevated production of reactive oxygen species (ROS), activate mitogen activated protein kinases (MAPKs) and PPARβ/δ receptor, induce transcription factors and growth factors including NF-κB and VEGF, trigger apoptotic machinery and induce several inflammatory cytokines, including TNF-α and IL-1β . This pathological cascade is responsible for the testicular atrophy, decreased blood flow and impaired spermatogenesis. Several pharmacological approaches have been characterized as promising therapeutic agents for the management of testicular torsion and may be useful to ameliorate the sequel of this disease.

  3. Overexpression of HIF-1α in mesenchymal stem cells contributes to repairing hypoxic-ischemic brain damage in rats.

    Science.gov (United States)

    Lin, Deju; Zhou, Liping; Wang, Biao; Liu, Lizhen; Cong, Li; Hu, Chuanqin; Ge, Tingting; Yu, Qin

    2017-01-01

    Preclinical researches on mesenchymal stem cells (MSCs) transplantation, which is used to treat hypoxic-ischemic (HI) brain damage, have received inspiring achievements. However, the insufficient migration of active cells to damaged tissues has limited their potential therapeutic effects. There are some evidences that hypoxia inducible factor-1 alpha (HIF-1α) promotes the viability and migration of the cells. Here, we aim to investigate whether overexpression of HIF-1α in MSCs could improve the viability and migration capacity of cells, and its therapeutic efficiency on HI brain damage. In the study, MSCs with HIF-1α overexpression was achieved by recombinant lentiviral vector and transplanted to the rats subsequent to HI. Our data indicated that overexpression of HIF-1α promoted the viability and migration of MSCs, HIF-1α overexpressed MSCs also had a stronger therapeutic efficiency on HI brain damaged treatment by mitigating the injury on behavioral and histological changes evoked by HI insults, accompanied with more MSCs migrating to cerebral damaged area. This study demonstrated that HIF-1α overexpression could increase the MSCs' therapeutic efficiency in HI and the promotion of the cells' directional migration to cerebral HI area by overexpression may be responsible for it, which showed that transplantation of MSCs with HIF-1α overexpression is an attractive therapeutic option to treat HI-induced brain injury in the future. Copyright © 2016 Académie des sciences. Published by Elsevier SAS. All rights reserved.

  4. Targeting Oxidatively Induced DNA Damage Response in Cancer: Opportunities for Novel Cancer Therapies

    Directory of Open Access Journals (Sweden)

    Pierpaola Davalli

    2018-01-01

    Full Text Available Cancer is a death cause in economically developed countries that results growing also in developing countries. Improved outcome through targeted interventions faces the scarce selectivity of the therapies and the development of resistance to them that compromise the therapeutic effects. Genomic instability is a typical cancer hallmark due to DNA damage by genetic mutations, reactive oxygen and nitrogen species, ionizing radiation, and chemotherapeutic agents. DNA lesions can induce and/or support various diseases, including cancer. The DNA damage response (DDR is a crucial signaling-transduction network that promotes cell cycle arrest or cell death to repair DNA lesions. DDR dysregulation favors tumor growth as downregulated or defective DDR generates genomic instability, while upregulated DDR may confer treatment resistance. Redox homeostasis deeply and capillary affects DDR as ROS activate/inhibit proteins and enzymes integral to DDR both in healthy and cancer cells, although by different routes. DDR regulation through modulating ROS homeostasis is under investigation as anticancer opportunity, also in combination with other treatments since ROS affect DDR differently in the patients during cancer development and treatment. Here, we highlight ROS-sensitive proteins whose regulation in oxidatively induced DDR might allow for selective strategies against cancer that are better tailored to the patients.

  5. Comparative Effects of Phosphoenolpyruvate, a Glycolytic Intermediate, as an Organ Preservation Agent with Glucose and N-Acetylcysteine against Organ Damage during Cold Storage of Mouse Liver and Kidney

    OpenAIRE

    Ishitsuka, Yoichi; Fukumoto, Yusuke; Kondo, Yuki; Irikura, Mitsuru; Kadowaki, Daisuke; Narita, Yuki; Hirata, Sumio; Moriuchi, Hiroshi; Maruyama, Toru; Hamasaki, Naotaka; Irie, Tetsumi

    2013-01-01

    We evaluated the usefulness of phosphoenolpyruvate (PEP), a glycolytic intermediate with antioxidative and energy supplementation potentials, as an organ preservation agent. Using ex vivo mouse liver and kidney of a static cold storage model, we compared the effects of PEP against organ damage and oxidative stress during cold preservation with those of glucose or N-acetylcysteine (NAC). Lactate dehydrogenase (LDH) leakage, histological changes, and oxidative stress parameters (measured as thi...

  6. Tofacitinib Suppresses Antibody Responses to Protein Therapeutics in Murine Hosts1

    Science.gov (United States)

    Onda, Masanori; Ghoreschi, Kamran; Steward-Tharp, Scott; Thomas, Craig; O’Shea, John J.; Pastan, Ira H.; FitzGerald, David J.

    2014-01-01

    Immunogenicity remains the ‘Achilles’ heel’ of protein-based therapeutics. Anti-drug antibodies produced in response to protein therapeutics can severely limit both the safety and efficacy of this expanding class of agent. Here we report that monotherapy of mice with tofacitinib (the Janus kinase inhibitor) quells antibody responses to an immunotoxin derived from the bacterial protein, Pseudomonas exotoxin A, as well as to the model antigen, keyhole limpet hemocyanin. Thousandfold reductions in IgG1 titers to both antigens were observed 21 days post-immunization. In fact, suppression was evident for all IgG isotypes and IgM. A reduction in IgG3 production was also noted with a thymus-independent type II antigen. Mechanistic investigations revealed that tofacitinib treatment led to reduced numbers of CD127+ pro-B cells. Furthermore, we observed fewer germinal center B cells and the impaired formation of germinal centers of mice treated with tofacitinib. Since normal immunoglobulin levels were still present during the tofacitinib treatment, this agent specifically reduced anti-drug antibodies, thus preserving the potential efficacy of biological therapeutics, including those that are used as cancer therapeutics. PMID:24890727

  7. Targeted Therapeutic Nanoparticles: An Immense Promise to Fight against Cancer

    Directory of Open Access Journals (Sweden)

    Sheikh Tasnim Jahan

    2017-01-01

    Full Text Available In nanomedicine, targeted therapeutic nanoparticle (NP is a virtual outcome of nanotechnology taking the advantage of cancer propagation pattern. Tying up all elements such as therapeutic or imaging agent, targeting ligand, and cross-linking agent with the NPs is the key concept to deliver the payload selectively where it intends to reach. The microenvironment of tumor tissues in lymphatic vessels can also help targeted NPs to achieve their anticipated accumulation depending on the formulation objectives. This review accumulates the application of poly(lactic-co-glycolic acid (PLGA and polyethylene glycol (PEG based NP systems, with a specific perspective in cancer. Nowadays, PLGA, PEG, or their combinations are the mostly used polymers to serve the purpose of targeted therapeutic NPs. Their unique physicochemical properties along with their biological activities are also discussed. Depending on the biological effects from parameters associated with existing NPs, several advantages and limitations have been explored in teaming up all the essential facts to give birth to targeted therapeutic NPs. Therefore, the current article will provide a comprehensive review of various approaches to fabricate a targeted system to achieve appropriate physicochemical properties. Based on such findings, researchers can realize the benefits and challenges for the next generation of delivery systems.

  8. Renal Sympathetic Denervation System via Intraluminal Ultrasonic Ablation: Therapeutic Intravascular Ultrasound Design and Preclinical Evaluation.

    Science.gov (United States)

    Chernin, Gil; Szwarcfiter, Iris; Bausback, Yvonne; Jonas, Michael

    2017-05-01

    To assess the safety and performance of a nonfocused and nonballooned ultrasonic (US) catheter-based renal sympathetic denervation (RDN) system in normotensive swine. RDN with the therapeutic intravascular US catheter was evaluated in 3 experiments: (i) therapeutic intravascular US RDN vs a control group of untreated animals with follow-up of 30, 45, and 90 days (n = 6; n = 12 renal arteries for each group); (ii) therapeutic intravascular US RDN vs radiofrequency (RF) RDN in the contralateral artery in the same animal (n = 2; n = 4 renal arteries); and (iii) therapeutic intravascular US RDN in a recently stent-implanted renal artery (n = 2; n = 4 renal arteries). In the first experiment, therapeutic intravascular US RDN was safe, without angiographic evidence of dissection or renal artery stenosis. Neuronal tissue vacuolization, nuclei pyknosis, and perineuronal inflammation were evident after RDN, without renal artery wall damage. Norepinephrine levels were significantly lower after therapeutic intravascular US RDN after 30, 45, and 90 days compared with the control group (200.17 pg/mg ± 63.35, 184.75 pg/mg ± 44.51, and 203.43 pg/mg ± 58.54, respectively, vs 342.42 pg/mg ± 79.97). In the second experiment, deeper neuronal ablation penetrance was found with therapeutic intravascular US RDN vs RF RDN (maximal penetrance from endothelium of 7.0 mm vs 3.5 mm, respectively). There was less damage to the artery wall after therapeutic intravascular US RDN than with RF RDN, after which edema and injured endothelium were seen. In the third experiment, denervation inside the stent-implanted segments was feasible without damage to the renal artery wall or stent. The therapeutic intravascular US system performed safely and reduced norepinephrine levels. Deeper penetrance and better preservation of vessel wall were observed with therapeutic intravascular US RDN vs RF RDN. Neuronal ablations were observed in stent-implanted renal arteries. Copyright © 2017 SIR. Published

  9. Development of Novel Therapeutic Agents by Inhibition of Oncogenic MicroRNAs

    Directory of Open Access Journals (Sweden)

    Dinh-Duc Nguyen

    2017-12-01

    Full Text Available MicroRNAs (miRs, miRNAs are regulatory small noncoding RNAs, with their roles already confirmed to be important for post-transcriptional regulation of gene expression affecting cell physiology and disease development. Upregulation of a cancer-causing miRNA, known as oncogenic miRNA, has been found in many types of cancers and, therefore, represents a potential new class of targets for therapeutic inhibition. Several strategies have been developed in recent years to inhibit oncogenic miRNAs. Among them is a direct approach that targets mature oncogenic miRNA with an antisense sequence known as antimiR, which could be an oligonucleotide or miRNA sponge. In contrast, an indirect approach is to block the biogenesis of miRNA by genome editing using the CRISPR/Cas9 system or a small molecule inhibitor. The development of these inhibitors is straightforward but involves significant scientific and therapeutic challenges that need to be resolved. In this review, we summarize recent relevant studies on the development of miRNA inhibitors against cancer.

  10. Bilirubin and its oxidation products damage brain white matter

    Science.gov (United States)

    Lakovic, Katarina; Ai, Jinglu; D'Abbondanza, Josephine; Tariq, Asma; Sabri, Mohammed; Alarfaj, Abdullah K; Vasdev, Punarjot; Macdonald, Robert Loch

    2014-01-01

    Brain injury after intracerebral hemorrhage (ICH) occurs in cortex and white matter and may be mediated by blood breakdown products, including hemoglobin and heme. Effects of blood breakdown products, bilirubin and bilirubin oxidation products, have not been widely investigated in adult brain. Here, we first determined the effect of bilirubin and its oxidation products on the structure and function of white matter in vitro using brain slices. Subsequently, we determined whether these compounds have an effect on the structure and function of white matter in vivo. In all, 0.5 mmol/L bilirubin treatment significantly damaged both the function and the structure of myelinated axons but not the unmyelinated axons in brain slices. Toxicity of bilirubin in vitro was prevented by dimethyl sulfoxide. Bilirubin oxidation products (BOXes) may be responsible for the toxicity of bilirubin. In in vivo experiments, unmyelinated axons were found more susceptible to damage from bilirubin injection. These results suggest that unmyelinated axons may have a major role in white-matter damage in vivo. Since bilirubin and BOXes appear in a delayed manner after ICH, preventing their toxic effects may be worth investigating therapeutically. Dimethyl sulfoxide or its structurally related derivatives may have a potential therapeutic value at antagonizing axonal damage after hemorrhagic stroke. PMID:25160671

  11. Co-culturing of Fungal Strains Against Botrytis cinerea as a Model for the Induction of Chemical Diversity and Therapeutic Agents

    Directory of Open Access Journals (Sweden)

    Olga Genilloud

    2017-04-01

    Full Text Available New fungal SMs (SMs have been successfully described to be produced by means of in vitro-simulated microbial community interactions. Co-culturing of fungi has proved to be an efficient way to induce cell–cell interactions that can promote the activation of cryptic pathways, frequently silent when the strains are grown in laboratory conditions. Filamentous fungi represent one of the most diverse microbial groups known to produce bioactive natural products. Triggering the production of novel antifungal compounds in fungi could respond to the current needs to fight health compromising pathogens and provide new therapeutic solutions. In this study, we have selected the fungus Botrytis cinerea as a model to establish microbial interactions with a large set of fungal strains related to ecosystems where they can coexist with this phytopathogen, and to generate a collection of extracts, obtained from their antagonic microbial interactions and potentially containing new bioactive compounds. The antifungal specificity of the extracts containing compounds induced after B. cinerea interaction was determined against two human fungal pathogens (Candida albicans and Aspergillus fumigatus and three phytopathogens (Colletotrichum acutatum, Fusarium proliferatum, and Magnaporthe grisea. In addition, their cytotoxicity was also evaluated against the human hepatocellular carcinoma cell line (HepG2. We have identified by LC-MS the production of a wide variety of known compounds induced from these fungal interactions, as well as novel molecules that support the potential of this approach to generate new chemical diversity and possible new therapeutic agents.

  12. Localized sequence-specific release of a chemopreventive agent and an anticancer drug in a time-controllable manner to enhance therapeutic efficacy.

    Science.gov (United States)

    Pan, Wen-Yu; Lin, Kun-Ju; Huang, Chieh-Cheng; Chiang, Wei-Lun; Lin, Yu-Jung; Lin, Wei-Chih; Chuang, Er-Yuan; Chang, Yen; Sung, Hsing-Wen

    2016-09-01

    Combination chemotherapy with multiple drugs commonly requires several injections on various schedules, and the probability that the drug molecules reach the diseased tissues at the proper time and effective therapeutic concentrations is very low. This work elucidates an injectable co-delivery system that is based on cationic liposomes that are adsorbed on anionic hollow microspheres (Lipos-HMs) via electrostatic interaction, from which the localized sequence-specific release of a chemopreventive agent (1,25(OH)2D3) and an anticancer drug (doxorubicin; DOX) can be thermally driven in a time-controllable manner by an externally applied high-frequency magnetic field (HFMF). Lipos-HMs can greatly promote the accumulation of reactive oxygen species (ROS) in tumor cells by reducing their cytoplasmic expression of an antioxidant enzyme (superoxide dismutase) by 1,25(OH)2D3, increasing the susceptibility of cancer cells to the cytotoxic action of DOX. In nude mice that bear xenograft tumors, treatment with Lipos-HMs under exposure to HFMF effectively inhibits tumor growth and is the most effective therapeutic intervention among all the investigated. These empirical results demonstrate that the synergistic anticancer effects of sequential release of 1,25(OH)2D3 and DOX from the Lipos-HMs may have potential for maximizing DOX cytotoxicity, supporting more effective cancer treatment. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. Neuroprotective effects of NAP against excitotoxic brain damage in the newborn mice: implications for cerebral palsy.

    Science.gov (United States)

    Sokolowska, P; Passemard, S; Mok, A; Schwendimann, L; Gozes, I; Gressens, P

    2011-01-26

    Activity-dependent neuroprotective protein (ADNP) was shown to be essential for embryogenesis and brain development while NAP, an active motif of ADNP, is neuroprotective in a broad range of neurodegenerative disorders. In the present study, we examined the protective potential of ADNP/NAP in a mouse model of excitotoxic brain lesion mimicking brain damage associated with cerebral palsy. We demonstrated that NAP had a potent neuroprotective effect against ibotenate-induced excitotoxic damage in the cortical plate and the white matter of P5 mice, and moderate against brain lesions of P0 mice. In contrast, endogenous ADNP appears not to be involved in the response to excitotoxic challenge in the studied model. Our findings further show that NAP reduced the number of apoptotic neurons through activation of PI-3K/Akt pathway in the cortical plate or both PI-3K/Akt and MAPK/MEK1 kinases in the white matter. In addition, NAP prevented ibotenate-induced loss of pre-oligodendrocytes without affecting the number of astrocytes or activated microglia around the site of injection. These findings indicate that protective actions of NAP are mediated by triggering transduction pathways that are crucial for neuronal and oligodendroglial survival, thus, NAP might be a promising therapeutic agent for treating developing brain damage. © 2011 IBRO. Published by Elsevier Ltd. All rights reserved.

  14. Possíveis etapas na patogênese da cefaléia tensional e indicações de tratamento Tension headache: possible pathogenic stages and its relations with therapeutic agents

    Directory of Open Access Journals (Sweden)

    Ceme Ferreira Jordy

    1995-09-01

    Full Text Available Análise de resultados obtidos no estudo de uma série de 100 pacientes com diagnóstico de cefaléia tensional permitem sugerir 5 etapas de um processo fisiopatogênico implicado. Com base nesta sugestão, a indicação para o tratamento e respectiva eficácia, dependerão da etapa patogênica sobre a qual se pretenda fazer incidir a ação terapêutica.Five steps in the pathogenic process involved in the tension headache pathogenesis are suggested from a 100 patients clinical study. Therapeutic efficacy in the treatment of the tension headache is considered to be linked to the relation between the therapeutic agent and the stage in which it has focused its effect, in the pathogenic process.

  15. Punica granatum and its therapeutic implications on breast carcinogenesis: A review.

    Science.gov (United States)

    Vini, Ravindran; Sreeja, Sreeharshan

    2015-01-01

    Punica granatum has a recorded history of pharmacological properties which can be attributed to its rich reservoir of phytochemicals. Investigations in recent years have established its tremendous potential as an antitumorogenic agent against various cancers including breast cancer, which is the second leading cause of cancer-related deaths in women. The plausible role of Punica as a therapeutic agent, as an adjuvant in chemotherapy, and its dietary implications as chemopreventive agent in breast cancer have been explored. Mechanistic studies have revealed that Punica extracts and its components, individually or in combination, can modulate and target key proteins and genes involved in breast cancer. Our earlier finding also demonstrated the role of methanolic extract of pomegranate pericarp in reducing proliferation in breast cancer by binding to estrogen receptor at the same time not affecting uterine weight unlike estradiol or tamoxifen. This review analyses other plausible mechanisms of Punica in preventing the progression of breast cancer and how it can possibly be a therapeutic agent by acting at various steps of carcinogenesis including proliferation, invasion, migration, metastasis, angiogenesis, and inflammation via various molecular mechanisms. © 2015 International Union of Biochemistry and Molecular Biology.

  16. Antimicrobial Peptides: An Emerging Category of Therapeutic Agents.

    Science.gov (United States)

    Mahlapuu, Margit; Håkansson, Joakim; Ringstad, Lovisa; Björn, Camilla

    2016-01-01

    Antimicrobial peptides (AMPs), also known as host defense peptides, are short and generally positively charged peptides found in a wide variety of life forms from microorganisms to humans. Most AMPs have the ability to kill microbial pathogens directly, whereas others act indirectly by modulating the host defense systems. Against a background of rapidly increasing resistance development to conventional antibiotics all over the world, efforts to bring AMPs into clinical use are accelerating. Several AMPs are currently being evaluated in clinical trials as novel anti-infectives, but also as new pharmacological agents to modulate the immune response, promote wound healing, and prevent post-surgical adhesions. In this review, we provide an overview of the biological role, classification, and mode of action of AMPs, discuss the opportunities and challenges to develop these peptides for clinical applications, and review the innovative formulation strategies for application of AMPs.

  17. Experimental study of plasmapheresis therapeutic efficacy in severe radiation damage

    International Nuclear Information System (INIS)

    Legeza, V.I.; Abdul', Yu.A.; Chigareva, N.G.; Petkevich, N.V.; Myasoedov, A.F.; Andryukhin, V.I.; Artemenko, A.G.

    1994-01-01

    In experiments with dogs exposed to 2.9 Gy (LD 80/45 ) it was found that plasmapheresis treatment 4-6 h after irradiation reduce the severity of the radiation sickness clinical manifestations and post-radiation toxemia thus increasing the rate of animal survival up to 60 %. Sham plasmapheresis included all the manipulations of plasmapheretic treatment except plasma substitution and had no detoxication effect and did not affect the irradiated animals survival. This is evidence for leading role of detoxiation in the mechanisms of th therapeutic action of plasmapheresis in acute irradiation

  18. Radioprotection: mechanism and radioprotective agents including honeybee venom

    Energy Technology Data Exchange (ETDEWEB)

    Varanda, E.A.; Tavares, D.C. [UNESP, Araraquara, SP (Brazil). Escola de Ciencias Farmaceuticas. Dept. de Ciencias Biologicas

    1998-07-01

    Since 1949, a great deal of research has been carried on the radioprotective action of chemical substances. These substances have shown to reduce mortality when administered to animals prior to exposure to a lethal dose of radiation. This fact is of considerable importance since it permits reduction of radiation-induced damage and provides prophylactic treatment for the damaging effects produced by radiotherapy. The following radioprotection mechanisms were proposed: free radical scavenger, repair by hydrogen donation to target molecules formation of mixed disulfides, delay of cellular division and induction of hypoxia in the tissues. Radioprotective agents have been divided into four major groups: the thiol compounds, other sulfur compounds, pharmacological agents (anesthetic drugs, analgesics, tranquilizers, etc.) and other radioprotective agents (WR-1065, WR-2721, vitamins C and E, glutathione, etc.). Several studies revealed the radioprotective action of Apis mellifera honeybee venom as well as that of its components mellitin and histamine. Radioprotective activity of bee venom involves mainly the stimulation of the hematopoietic system. In addition, release of histamine and reduction in oxygen tension also contribute to the radioprotective action of bee venom. (author)

  19. Radioprotection: mechanism and radioprotective agents including honeybee venom

    International Nuclear Information System (INIS)

    Varanda, E.A.; Tavares, D.C.

    1998-01-01

    Since 1949, a great deal of research has been carried on the radioprotective action of chemical substances. These substances have shown to reduce mortality when administered to animals prior to exposure to a lethal dose of radiation. This fact is of considerable importance since it permits reduction of radiation-induced damage and provides prophylactic treatment for the damaging effects produced by radiotherapy. The following radioprotection mechanisms were proposed: free radical scavenger, repair by hydrogen donation to target molecules formation of mixed disulfides, delay of cellular division and induction of hypoxia in the tissues. Radioprotective agents have been divided into four major groups: the thiol compounds, other sulfur compounds, pharmacological agents (anesthetic drugs, analgesics, tranquilizers, etc.) and other radioprotective agents (WR-1065, WR-2721, vitamins C and E, glutathione, etc.). Several studies revealed the radioprotective action of Apis mellifera honeybee venom as well as that of its components mellitin and histamine. Radioprotective activity of bee venom involves mainly the stimulation of the hematopoietic system. In addition, release of histamine and reduction in oxygen tension also contribute to the radioprotective action of bee venom. (author)

  20. [Therapeutic use of cannabis derivatives].

    Science.gov (United States)

    Benyamina, Amine; Reynaud, Michel

    2014-02-01

    The therapeutic use of cannabis has generated a lot of interest in the past years, leading to a better understanding of its mechanisms of action. Countries like the United States and Canada have modified their laws in order to make cannabinoid use legal in the medical context. It's also the case in France now, where a recent decree was issued, authorizing the prescription of medication containing "therapeutic cannabis" (decree no. 2013-473, June 5, 2013). Cannabinoids such as dronabinol, Sativex and nabilone have been tested for the treatment of acute and chronic pain. These agents are most promising to relieve chronic pain associated with cancer, with human immunodeficiency virus infection and with multiple sclerosis. However, longer-term studies are required to determine potential long-term adverse effects and risks of misuse and addiction.

  1. Damage pattern as a function of radiation quality and other factors.

    Science.gov (United States)

    Burkart, W; Jung, T; Frasch, G

    1999-01-01

    An understanding of damage pattern in critical cellular structures such as DNA is an important prerequisite for a mechanistic assessment of primary radiation damage, its possible repair, and the propagation of residual changes in somatic and germ cells as potential contributors to disease or ageing. Important quantitative insights have been made recently on the distribution in time and space of critical lesions from direct and indirect action of ionizing radiation on mammalian cells. When compared to damage from chemicals or from spontaneous degradation, e.g. depurination or base deamination in DNA, the potential of even low-LET radiation to create local hot spots of damage from single particle tracks is of utmost importance. This has important repercussions on inferences from critical biological effects at high dose and dose rate exposure situations to health risks at chronic, low-level exposures as experienced in environmental and controlled occupational settings. About 10,000 DNA lesions per human cell nucleus and day from spontaneous degradation and chemical attack cause no apparent effect, but a dose of 4 Gy translating into a similar number of direct and indirect DNA breaks induces acute lethality. Therefore, single lesions cannot explain the high efficiency of ionizing radiation in the induction of mutation, transformation and loss of proliferative capacity. Clustered damage leading to poorly repairable double-strand breaks or even more complex local DNA degradation, correlates better with fixed damage and critical biological endpoints. A comparison with other physical, chemical and biological agents indicates that ionizing radiation is indeed set apart from these by its unique micro- and nano-dosimetric traits. Only a few other agents such as bleomycin have a similar potential to cause complex damage from single events. However, in view of the multi-stage mechanism of carcinogenesis, it is still an open question whether dose-effect linearity for complex

  2. Chemoprotective Effect of Taurine on Potassium Bromate-Induced DNA Damage, DNA-Protein Cross-Linking and Oxidative Stress in Rat Intestine

    Science.gov (United States)

    Ahmad, Mir Kaisar; Khan, Aijaz Ahmed; Ali, Shaikh Nisar; Mahmood, Riaz

    2015-01-01

    Potassium bromate (KBrO3) is widely used as a food additive and is a major water disinfection by-product. It induces multiple organ toxicity in humans and experimental animals and is a probable human carcinogen. The present study reports the protective effect of dietary antioxidant taurine on KBrO3-induced damage to the rat intestine. Animals were randomly divided into four groups: control, KBrO3 alone, taurine alone and taurine+ KBrO3. Administration of KBrO3 alone led to decrease in the activities of intestinal brush border membrane enzymes while those of antioxidant defence and carbohydrate metabolism were also severely altered. There was increase in DNA damage and DNA-protein cross-linking. Treatment with taurine, prior to administration of KBrO3, resulted in significant attenuation in all these parameters but the administration of taurine alone had no effect. Histological studies supported these biochemical results showing extensive intestinal damage in KBrO3-treated animals and greatly reduced tissue injury in the taurine+ KBrO3 group. These results show that taurine ameliorates bromate induced tissue toxicity and oxidative damage by improving the antioxidant defence, tissue integrity and energy metabolism. Taurine can, therefore, be potentially used as a therapeutic/protective agent against toxicity of KBrO3 and related compounds. PMID:25748174

  3. DNA damage responses in human induced pluripotent stem cells and embryonic stem cells.

    Directory of Open Access Journals (Sweden)

    Olga Momcilovic

    2010-10-01

    Full Text Available Induced pluripotent stem (iPS cells have the capability to undergo self-renewal and differentiation into all somatic cell types. Since they can be produced through somatic cell reprogramming, which uses a defined set of transcription factors, iPS cells represent important sources of patient-specific cells for clinical applications. However, before these cells can be used in therapeutic designs, it is essential to understand their genetic stability.Here, we describe DNA damage responses in human iPS cells. We observe hypersensitivity to DNA damaging agents resulting in rapid induction of apoptosis after γ-irradiation. Expression of pluripotency factors does not appear to be diminished after irradiation in iPS cells. Following irradiation, iPS cells activate checkpoint signaling, evidenced by phosphorylation of ATM, NBS1, CHEK2, and TP53, localization of ATM to the double strand breaks (DSB, and localization of TP53 to the nucleus of NANOG-positive cells. We demonstrate that iPS cells temporary arrest cell cycle progression in the G(2 phase of the cell cycle, displaying a lack of the G(1/S cell cycle arrest similar to human embryonic stem (ES cells. Furthermore, both cell types remove DSB within six hours of γ-irradiation, form RAD51 foci and exhibit sister chromatid exchanges suggesting homologous recombination repair. Finally, we report elevated expression of genes involved in DNA damage signaling, checkpoint function, and repair of various types of DNA lesions in ES and iPS cells relative to their differentiated counterparts.High degrees of similarity in DNA damage responses between ES and iPS cells were found. Even though reprogramming did not alter checkpoint signaling following DNA damage, dramatic changes in cell cycle structure, including a high percentage of cells in the S phase, increased radiosensitivity and loss of DNA damage-induced G(1/S cell cycle arrest, were observed in stem cells generated by induced pluripotency.

  4. Photoactivatable Lipid-based Nanoparticles as a Vehicle for Dual Agent Delivery | NCI Technology Transfer Center | TTC

    Science.gov (United States)

    Researchers at the National Cancer Institute (NCI) RNA Biology Laboratory have developed nanoparticles that can deliver an agent (i.e., therapeutic or imaging) and release the agent upon targeted photoactivation allowing for controlled temporal and localized release of the agent.

  5. Avian Diagnostic and Therapeutic Antibodies

    Energy Technology Data Exchange (ETDEWEB)

    Bradley, David Sherman [UND SMHS

    2012-12-31

    A number of infectious agents have the potential of causing significant clinical symptomology and even death, but dispite this, the number of incidence remain below the level that supports producing a vaccine. Therapeutic antibodies provide a viable treatment option for many of these diseases. We proposed that antibodies derived from West Nile Virus (WNV) immunized geese would be able to treat WNV infection in mammals and potential humans. We demonstrated that WNV specific goose antibodies are indeed successful in treating WNV infection both prophylactically and therapeutically in a golden hamster model. We demonstrated that the goose derived antibodies are non-reactogenic, i.e. do not cause an inflammatory response with multiple exposures in mammals. We also developed both a specific pathogen free facility to house the geese during the antibody production phase and a patent-pending purification process to purify the antibodies to greater than 99% purity. Therefore, the success of these study will allow a cost effective rapidly producible therapeutic toward clinical testing with the necessary infrastructure and processes developed and in place.

  6. Anti-herpesvirus agents: a patent and literature review (2003 to present).

    Science.gov (United States)

    Skoreński, Marcin; Sieńczyk, Marcin

    2014-08-01

    The standard therapy used to treat herpesvirus infections is based on the application of DNA polymerase inhibitors such as ganciclovir or aciclovir. Unfortunately, all of these compounds exhibit relatively high toxicity and the mutation of herpesviruses results in the appearance of new drug-resistant strains. Consequently, there is a great need for the development of new, effective and safe anti-herpesvirus agents that employ different patterns of therapeutic action at various stages of the virus life cycle. Patents and patent applications concerning the development of anti-herpesvirus agents displaying different mechanisms of action that have been published since 2003 are reviewed. In addition, major discoveries in this field that have been published in academic papers have also been included. Among all the anti-herpesvirus agents described in this article, the inhibitors of viral serine protease seem to present one of the most effective/promising therapeutics. Unfortunately, the practical application of these antiviral agents has not yet been proven in any clinical trials. Nevertheless, the dynamic and extensive work on this subject gives hope that a new class of anti-herpesvirus agents aimed at the enzymatic activity of herpesvirus serine protease may be developed.

  7. Reactor-produced therapeutic radioisotopes

    International Nuclear Information System (INIS)

    Knapp, F.F. Jr.

    2002-01-01

    The significant worldwide increase in therapeutic radioisotope applications in nuclear medicine, oncology and interventional cardiology requires the dependable production of sufficient levels of radioisotopes for these applications (Reba, 2000; J. Nucl. Med., 1998; Nuclear News, 1999; Adelstein and Manning, 1994). The issues associated with both accelerator- and reactor-production of therapeutic radioisotopes is important. Clinical applications of therapeutic radioisotopes include the use of both sealed sources and unsealed radiopharmaceutical sources. Targeted radiopharmaceutical agents include those for cancer therapy and palliation of bone pain from metastatic disease, ablation of bone marrow prior to stem cell transplantation, treatment modalities for mono and oligo- and polyarthritis, for cancer therapy (including brachytherapy) and for the inhibition of the hyperplastic response following coronary angioplasty and other interventional procedures (For example, see Volkert and Hoffman, 1999). Sealed sources involve the use of radiolabeled devices for cancer therapy (brachytherapy) and also for the inhibition of the hyperplasia which is often encountered after angioplasty, especially with the exponential increase in the use of coronary stents and stents for the peripheral vasculature and other anatomical applications. Since neutron-rich radioisotopes often decay by beta decay or decay to beta-emitting daughter radioisotopes which serve as the basis for radionuclide generator systems, reactors are expected to play an increasingly important role for the production of a large variety of therapeutic radioisotopes required for these and other developing therapeutic applications. Because of the importance of the availability of reactor-produced radioisotopes for these applications, an understanding of the contribution of neutron spectra for radioisotope production and determination of those cross sections which have not yet been established is important. This

  8. Development of a Multifaceted Ovarian Cancer Therapeutic and Imaging Agent

    Science.gov (United States)

    2011-04-01

    by 1-ethyl-3- [3-(dimethylamino) propyl ]carbodiimide (EDC) and N-hydroxysulfonosuccinimide (SNHS) at pH 5.5 for 30 min with a molar ratio of...particle-coated migratory substrate that can act as a permanent record of cellular movement. The gold chloride solution was prepared using 0.342 g... Synthesis and clinical Evaluation. Anticancer Agents Med. Chem. McLane, M.A., Joerger, T., Mahmoud, A., 2008. Disintegrins in health and disease. Front

  9. Proposed Pharmacological Countermeasures Against Apoptotic Cell Death in Experimental Models Mimicking Space Environment Damage

    Science.gov (United States)

    Lulli, Matteo; Papucci, Laura; Witort, Ewa; Donnini, Martino; Lapucci, Andrea; Lazzarano, Stefano; Mazzoni, Tiziano; Simoncini, Madine; Falciani, Piergiuseppe; Capaccioli, Sergio

    2008-06-01

    Several damaging agents have been suggested to affect human vision during long term space travels. Recently, apoptosis induced by DNA-damaging agents has emerged as frequent pathogenetic mechanism of ophthalmologic pathologies. Here, we propose two countermeasures: coenzyme Q10 and bcl-2 downregulation preventing antisense oligoribonucleotides (ORNs), aimed to inhibit cellular apoptotic death. Our studies have been carried out on retina and neuronal cultured cells treated with the following apoptotic stimuli mimicking space environment: a several-day exposure to either 3H-labeled tymidine or to the genotoxic drug doxorubicin, UV irradiation, hypoxia and glucose/growth factor starvation (Locke medium). The preliminary results clearly indicate that CoQ10, as well as bcl-2 down-regulation preventing ORNs, significantly counteract apoptosis in response to different DNA damaging agents in cultured eye and in neuronal cells. This supports the possibility that both could be optimal countermeasures against ophthalmologic lesions during space explorations.

  10. Effect of time intervals between irradiation and chemotherapeutic agents on the normal tissue damage. Comparison between in vivo and in vitro experiments

    Energy Technology Data Exchange (ETDEWEB)

    Ito, Hisao; Nakayama, Toshitake; Hashimoto, Shozo (Keio Univ., Tokyo (Japan). School of Medicine)

    1989-05-01

    Experiments have been carried out to determine the effect on the cell survivals at different time intervals between irradiation and chemotherapeutic agents (BLM, cisDDP, ADM and ACNU) in either the in vivo or the in vitro system. The intestinal epithelial assay was applied on the in vivo system. The clonogenic cell survivals of V/sub 79/ cells, both in the proliferative and the plateau phases, were determined in the in vitro system. The V/sub 79/ cells in the plateau phase were more sensitive to BLM, cisDDP and ACNU than those in the proliferative phase, however, the result was reverse with ADM. When BLM, cisDDP or ACNU was combined with irradiation at different time intervals, the response of the plateau phase V/sub 79/ cells to combination therapies were very similar to those of the intestinal epithelial cells. On the other hand, V/sub 79/ cells in the proliferative phase, which were treated with ADM and irradiation, showed the similar response as the intestinal cells. These results suggest that studies of chemo-radiotherapy with cultured cells which are sensitive to chemotherapeutic agents might be suitable to expect the in vivo damage of the normal tissue. (author).

  11. Potential of Icariin Metabolites from Epimedium koreanum Nakai as Antidiabetic Therapeutic Agents

    Directory of Open Access Journals (Sweden)

    Da Hye Kim

    2017-06-01

    Full Text Available The therapeutic properties of Epimedium koreanum are presumed to be due to the flavonoid component icariin, which has been reported to have broad pharmacological potential and has demonstrated anti-diabetic, anti-Alzheimer’s disease, anti-tumor, and hepatoprotective activities. Considering these therapeutic properties of icariin, its deglycosylated icaritin and glycosylated flavonoids (icaeriside II, epimedin A, epimedin B, and epimedin C were evaluated for their ability to inhibit protein tyrosine phosphatase 1B (PTP1B and α-glucosidase. The results show that icaritin and icariside II exhibit potent inhibitory activities, with 50% inhibition concentration (IC50 values of 11.59 ± 1.39 μM and 9.94 ± 0.15 μM against PTP1B and 74.42 ± 0.01 and 106.59 ± 0.44 μM against α-glucosidase, respectively. With the exceptions of icaritin and icariside II, glycosylated flavonoids did not exhibit any inhibitory effects in the two assays. Enzyme kinetics analyses revealed that icaritin and icariside II demonstrated noncompetitive-type inhibition against PTP1B, with inhibition constant (Ki values of 11.41 and 11.66 μM, respectively. Moreover, molecular docking analysis confirmed that icaritin and icariside II both occupy the same site as allosteric ligand. Thus, the molecular docking simulation results were in close agreement with the experimental data with respect to inhibition activity. In conclusion, deglycosylated metabolites of icariin from E. koreanum might offer therapeutic potential for the treatment of type 2 diabetes mellitus.

  12. Potential Therapeutic Uses of p19ARF Mimics in Mammary Tumorigenesis

    National Research Council Canada - National Science Library

    Hann, Stephen R

    2005-01-01

    Since many breast tumors have deregulated c-Myc we hypothesize that an ARF mimic would be a valuable therapeutic agent for breast cancer to inhibit c-Myc-induced transformation/tumorigenesis without...

  13. Evaluation of DNA-damaging marine natural product with potential anticancer activity

    International Nuclear Information System (INIS)

    Nisa, M.; Amjad, S.; Chaudhary, M.I.; Sualah, R.; Khan, S.H.

    2002-01-01

    The treatment for the dreadful disease cancer require a continued development of novel and improved chemo preventive and chemotherapeutic agents. An exploitable feature of tumor cell is that it has defect in its ability to repair damage to DNA as compared with normal cell, suggesting that agent with selective toxicity towards DNA repair deficient cell might be potential anticancer agent. In a recently developed mechanism based approach discovery. DNA repair a recombination-deficient mutants of the yeast Saccharomyces cerevisiae were utilized, as yeast and bacteria are the popular genetically engineered microorganisms. We have scanned organic solvent extracts of about thirty five different species of marine flora and fauna under DNA-damaging activity assays. Marine plants showed no activity towards this bioassay, whereas marine animals tested under this bioassay showed good activity. Detail results of our studies will be discussed in this paper. (author)

  14. Chromosome analyses of nurses handling cytostatic agents

    International Nuclear Information System (INIS)

    Waksvik, H.; Klepp, O.; Brogger, A.

    1981-01-01

    A cytogenetic study of ten nurses handling cytostatic agents (average exposure, 2150 hours) and ten female hospital clerks revealed an increased frequency of chromosome gaps and a slight increase in sister chromatid exchange frequency among the nurses. The increase may be due to exposure to cytostatic drugs and points to these agents as a possible occupational health hazard. A second group of 11 nurses handling cytostatic agents for a shorter period of time (average exposure, 1078 hours), and three other groups (eight nurses engaged in therapeutic and diagnostic radiology, nine nurses engaged in anesthesiology, and seven nurses in postoperative ward) did not differ from the office personnel, except for an increased frequency of chromosome gaps in the radiology group

  15. INHIBITION OF FRIED MEAT-INDUCED DNA DAMAGE: A DIETARY INTERVENTION STUDY IN HUMANS

    Science.gov (United States)

    Dietary exposures have been implicated as risk factors in colorectal cancer. Such agents may act by causing DNA damage or may be protective against DNA damage. The effects of dietary exposures in causing or preventing damage have not been assessed directly in colon tissues. In th...

  16. rad-Dependent response of the chk1-encoded protein kinase at the DNA damage checkpoint

    NARCIS (Netherlands)

    Walworth, N.C.; Bernards, R.A.

    1996-01-01

    Exposure of eukaryotic cells to agents that generate DNA damage results in transient arrest of progression through the cell cycle. In fission yeast, the DNA damage checkpoint associated with cell cycle arrest before mitosis requires the protein kinase p56chk1. DNA damage induced by ultraviolet

  17. Ultrasound-induced cavitation damage to external epithelia of fish skin.

    Science.gov (United States)

    Frenkel, V; Kimmel, E; Iger, Y

    1999-10-01

    Transmission electron microscopy was used to show the effects of therapeutic ultrasound (fish skin. Exposures of up to 90 s produced damage to 5 to 6 of the outermost layers. Negligible temperature elevations and lack of damage observed when using degassed water indicated that the effects were due to cavitation. The minimal intensity was determined for inducing cellular damage, where the extent and depth of damage to the tissues was correlated to the exposure duration. The results may be interpreted as a damage front, advancing slowly from the outer cells inward, presumably in association with the slow replacement of the perforated cell contents with the surrounding water. This study illustrates that a controlled level of microdamage may be induced to the outer layers of the tissues.

  18. Photoinduced membrane damage of E. coli and S. aureus by the photosensitizer-antimicrobial peptide conjugate eosin-(KLAKLAK2.

    Directory of Open Access Journals (Sweden)

    Gregory A Johnson

    Full Text Available BACKGROUND/OBJECTIVES: Upon irradiation with visible light, the photosensitizer-peptide conjugate eosin-(KLAKLAK2 kills a broad spectrum of bacteria without damaging human cells. Eosin-(KLAKLAK2 therefore represents an interesting lead compound for the treatment of local infection by photodynamic bacterial inactivation. The mechanisms of cellular killing by eosin-(KLAKLAK2, however, remain unclear and this lack of knowledge hampers the development of optimized therapeutic agents. Herein, we investigate the localization of eosin-(KLAKLAK2 in bacteria prior to light treatment and examine the molecular basis for the photodynamic activity of this conjugate. METHODOLOGY/PRINCIPAL FINDINGS: By employing photooxidation of 3,3-diaminobenzidine (DAB, (scanning transmission electron microscopy ((STEM, and energy dispersive X-ray spectroscopy (EDS methodologies, eosin-(KLAKLAK2 is visualized at the surface of E. coli and S. aureus prior to photodynamic irradiation. Subsequent irradiation leads to severe membrane damage. Consistent with these observations, eosin-(KLAKLAK2 binds to liposomes of bacterial lipid composition and causes liposomal leakage upon irradiation. The eosin moiety of the conjugate mediates bacterial killing and lipid bilayer leakage by generating the reactive oxygen species singlet oxygen and superoxide. In contrast, the (KLAKLAK2 moiety targets the photosensitizer to bacterial lipid bilayers. In addition, while (KLAKLAK2 does not disrupt intact liposomes, the peptide accelerates the leakage of photo-oxidized liposomes. CONCLUSIONS/SIGNIFICANCE: Together, our results suggest that (KLAKLAK2 promotes the binding of eosin Y to bacteria cell walls and lipid bilayers. Subsequent light irradiation results in membrane damage from the production of both Type I & II photodynamic products. Membrane damage by oxidation is then further aggravated by the (KLAKLAK2 moiety and membrane lysis is accelerated by the peptide. These results therefore

  19. Important role of the nucleotide excision repair pathway in Mycobacterium smegmatis in conferring protection against commonly encountered DNA-damaging agents.

    Science.gov (United States)

    Kurthkoti, Krishna; Kumar, Pradeep; Jain, Ruchi; Varshney, Umesh

    2008-09-01

    Mycobacteria are an important group of human pathogens. Although the DNA repair mechanisms in mycobacteria are not well understood, these are vital for the pathogen's persistence in the host macrophages. In this study, we generated a null mutation in the uvrB gene of Mycobacterium smegmatis to allow us to compare the significance of the nucleotide excision repair (NER) pathway with two important base excision repair pathways, initiated by uracil DNA glycosylase (Ung) and formamidopyrimidine DNA glycosylase (Fpg or MutM), in an isogenic strain background. The strain deficient in NER was the most sensitive to commonly encountered DNA-damaging agents such as UV, low pH, reactive oxygen species, hypoxia, and was also sensitive to acidified nitrite. Taken together with previous observations on NER-deficient M. tuberculosis, these results suggest that NER is an important DNA repair pathway in mycobacteria.

  20. Inhibition of exportin-1 function results in rapid cell cycle-associated DNA damage in cancer cells.

    Science.gov (United States)

    Burke, Russell T; Marcus, Joshua M; Orth, James D

    2017-06-13

    Selective inhibitors of nuclear export (SINE) are small molecules in development as anti-cancer agents. The first-in-class SINE, selinexor, is in clinical trials for blood and solid cancers. Selinexor forms a covalent bond with exportin-1 at cysteine-528, and blocks its ability to export cargos. Previous work has shown strong cell cycle effects and drug-induced cell death across many different cancer-derived cell lines. Here, we report strong cell cycle-associated DNA double-stranded break formation upon the treatment of cancer cells with SINE. In multiple cell models, selinexor treatment results in the formation of clustered DNA damage foci in 30-40% of cells within 8 hours that is dependent upon cysteine-528. DNA damage strongly correlates with G1/S-phase and decreased DNA replication. Live cell microscopy reveals an association between DNA damage and cell fate. Cells that form damage in G1-phase more often die or arrest, while those damaged in S/G2-phase frequently progress to cell division. Up to half of all treated cells form damage foci, and most cells that die after being damaged, were damaged in G1-phase. By comparison, non-transformed cell lines show strong cell cycle effects but little DNA damage and less death than cancer cells. Significant drug combination effects occur when selinexor is paired with different classes of agents that either cause DNA damage or that diminish DNA damage repair. These data present a novel effect of exportin-1 inhibition and provide a strong rationale for multiple combination treatments of selinexor with agents that are currently in use for the treatment of different solid cancers.

  1. Dendritic Cells Primed with Paracoccidioides brasiliensis Peptide P10 Are Therapeutic in Immunosuppressed Mice with Paracoccidioidomycosis

    Directory of Open Access Journals (Sweden)

    Leandro B. R. Silva

    2017-06-01

    Full Text Available Paracoccidioidomycosis (PCM is an endemic systemic mycosis in Latin America, with the highest prevalence in Brazil, Colombia, and Venezuela. Fungi of the Paracoccidioides genus are etiologic agents of the disease. The 15 amino acid peptide P10 is derived from gp43, the main diagnostic antigen of Paracoccidioides brasiliensis. We previously reported that P10-pulsed dendritic cells (DCs induce a protective response against P. brasiliensis. Presently, dexamethasone-treated BALB/c mice were intratracheally infected with P. brasiliensis Pb18 to establish the therapeutic efficacy of P10-pulsed DCs. Immunosuppressed and infected animals that received DCs had a reduction in their fungal burden, and this result was most pronounced in mice receiving DCs primed with P10. The efficacy of therapeutic DCs was significantly augmented by concomitant treatment with trimethoprim-sulfamethoxazole. Additionally, primed-DCs with or without the antifungal drug induced a beneficial Th1-biased immune response and significantly reduced tissue damage. In conclusion, these studies with immunocompromised mice demonstrate that P10-pulsed DCs with or without concomitant antifungal drugs are potently effective in combating invasive PCM. These findings support further translational studies to validate the use of P10-primed DCs for PCM in immunocompetent and immunosuppressed hosts.

  2. Multimodal nanoparticle imaging agents: design and applications

    Science.gov (United States)

    Burke, Benjamin P.; Cawthorne, Christopher; Archibald, Stephen J.

    2017-10-01

    Molecular imaging, where the location of molecules or nanoscale constructs can be tracked in the body to report on disease or biochemical processes, is rapidly expanding to include combined modality or multimodal imaging. No single imaging technique can offer the optimum combination of properties (e.g. resolution, sensitivity, cost, availability). The rapid technological advances in hardware to scan patients, and software to process and fuse images, are pushing the boundaries of novel medical imaging approaches, and hand-in-hand with this is the requirement for advanced and specific multimodal imaging agents. These agents can be detected using a selection from radioisotope, magnetic resonance and optical imaging, among others. Nanoparticles offer great scope in this area as they lend themselves, via facile modification procedures, to act as multifunctional constructs. They have relevance as therapeutics and drug delivery agents that can be tracked by molecular imaging techniques with the particular development of applications in optically guided surgery and as radiosensitizers. There has been a huge amount of research work to produce nanoconstructs for imaging, and the parameters for successful clinical translation and validation of therapeutic applications are now becoming much better understood. It is an exciting time of progress for these agents as their potential is closer to being realized with translation into the clinic. The coming 5-10 years will be critical, as we will see if the predicted improvement in clinical outcomes becomes a reality. Some of the latest advances in combination modality agents are selected and the progression pathway to clinical trials analysed. This article is part of the themed issue 'Challenges for chemistry in molecular imaging'.

  3. Differential expression of the klf6 tumor suppressor gene upon cell damaging treatments in cancer cells

    Energy Technology Data Exchange (ETDEWEB)

    Gehrau, Ricardo C.; D' Astolfo, Diego S.; Andreoli, Veronica [Centro de Investigaciones en Bioquimica Clinica e Inmunologia (CIBICI-CONICET), Departamento de Bioquimica Clinica, Facultad de Ciencias Quimicas, Universidad Nacional de Cordoba, Haya de la Torre y Medina Allende, Ciudad Universitaria, 5000 Cordoba (Argentina); Bocco, Jose L., E-mail: jbocco@fcq.unc.edu.ar [Centro de Investigaciones en Bioquimica Clinica e Inmunologia (CIBICI-CONICET), Departamento de Bioquimica Clinica, Facultad de Ciencias Quimicas, Universidad Nacional de Cordoba, Haya de la Torre y Medina Allende, Ciudad Universitaria, 5000 Cordoba (Argentina); Koritschoner, Nicolas P. [Centro de Investigaciones en Bioquimica Clinica e Inmunologia (CIBICI-CONICET), Departamento de Bioquimica Clinica, Facultad de Ciencias Quimicas, Universidad Nacional de Cordoba, Haya de la Torre y Medina Allende, Ciudad Universitaria, 5000 Cordoba (Argentina)

    2011-02-10

    The mammalian Krueppel-like factor 6 (KLF6) is involved in critical roles such as growth-related signal transduction, cell proliferation and differentiation, development, apoptosis and angiogenesis. Also, KLF6 appears to be an emerging key factor during cancer development and progression. Its expression is thoroughly regulated by several cell-damaging stimuli. DNA damaging agents at lethal concentrations induce a p53-independent down-regulation of the klf6 gene. To investigate the impact of external stimuli on human klf6 gene expression, its mRNA level was analyzed using a cancer cell line profiling array system, consisting in an assortment of immobilized cDNAs from multiple cell lines treated with several cell-damaging agents at growth inhibitory concentrations (IC{sub 50}). Cell-damaging agents affected the klf6 expression in 62% of the cDNA samples, though the expression pattern was not dependent on the cell origin type. Interestingly, significant differences (p < 0.0001) in KLF6 mRNA levels were observed depending on the cellular p53 status upon cell damage. KLF6 expression was significantly increased in 63% of p53-deficient cells (122/195). Conversely, KLF6 mRNA level decreased nearly 4 fold in more than 70% of p53+/+ cells. In addition, klf6 gene promoter activity was down-regulated by DNA damaging agents in cells expressing the functional p53 protein whereas it was moderately increased in the absence of functional p53. Consistent results were obtained for the endogenous KLF6 protein level. Results indicate that human klf6 gene expression is responsive to external cell damage mediated by IC{sub 50} concentrations of physical and chemical stimuli in a p53-dependent manner. Most of these agents are frequently used in cancer therapy. Induction of klf6 expression in the absence of functional p53 directly correlates with cell death triggered by these compounds, whereas it is down-regulated in p53+/+ cells. Hence, klf6 expression level could represent a valuable

  4. Dendrimer-based Macromolecular MRI Contrast Agents: Characteristics and Application

    Directory of Open Access Journals (Sweden)

    Hisataka Kobayashi

    2003-01-01

    Full Text Available Numerous macromolecular MRI contrast agents prepared employing relatively simple chemistry may be readily available that can provide sufficient enhancement for multiple applications. These agents operate using a ~100-fold lower concentration of gadolinium ions in comparison to the necessary concentration of iodine employed in CT imaging. Herein, we describe some of the general potential directions of macromolecular MRI contrast agents using our recently reported families of dendrimer-based agents as examples. Changes in molecular size altered the route of excretion. Smaller-sized contrast agents less than 60 kDa molecular weight were excreted through the kidney resulting in these agents being potentially suitable as functional renal contrast agents. Hydrophilic and larger-sized contrast agents were found better suited for use as blood pool contrast agents. Hydrophobic variants formed with polypropylenimine diaminobutane dendrimer cores created liver contrast agents. Larger hydrophilic agents are useful for lymphatic imaging. Finally, contrast agents conjugated with either monoclonal antibodies or with avidin are able to function as tumor-specific contrast agents, which also might be employed as therapeutic drugs for either gadolinium neutron capture therapy or in conjunction with radioimmunotherapy.

  5. Alkylating agent (MNU)-induced mutation in space environment

    Science.gov (United States)

    Ohnishi, T.; Takahashi, A.; Ohnishi, K.; Takahashi, S.; Masukawa, M.; Sekikawa, K.; Amano, T.; Nakano, T.; Nagaoka, S.

    2001-01-01

    In recent years, some contradictory data about the effects of microgravity on radiation-induced biological responses in space experiments have been reported. We prepared a damaged template DNA produced with an alkylating agent (N-methyl-N-nitroso urea; MNU) to measure incorrect base-incorporation during DNA replication in microgravity. We examined whether mutation frequency is affected by microgravity during DNA replication for a DNA template damaged by an alkylating agent. Using an in vitro enzymatic reaction system, DNA synthesis by Taq polymerase or polymerase III was done during a US space shuttle mission (Discovery, STS-91). After the flight, DNA replication and mutation frequencies were measured. We found that there was almost no effect of microgravity on DNA replication and mutation frequency. It is suggested that microgravity might not affect at the stage of substrate incorporation in induced-mutation frequency.

  6. Effect of TSUMURA Saiboku-to as an agent for healing damage in treatment of radiomucositis due to irradiation of the head and neck area and mediastinum

    Energy Technology Data Exchange (ETDEWEB)

    Saito, Yoshihiro (Tatebayashi Kosei Hospital, Gunma (Japan)); Mitsuhashi, Norio; Takahashi, Iku (and others)

    1992-12-01

    A joint multicenter study was conducted on the utility of TSUMURA Saiboku-to as an agent for healing radiation damage in treatment of radiomucositis due to irradiation of the head and neck area and mediastinum, with the following results. In a comparison of each clinical symptom, efficacy in the TSUMURA Saiboku-to group was not clear, but an overall evaluation of the individual cases showed a significantly increased number of subjects with evaluations of effective or better in the administration group. No serious side effects were observed. (author).

  7. MCM-41 mesoporous silica nanoparticles functionalized with aptamer and radiolabelled with {sup 90}Y and {sup 159}Gd as a potential therapeutic agent against colorectal cancer; Nanoparticulas de silica mesoporosa MCM-41 funcionalizadas com aptamero e radiomarcadas com {sup 90}Y e {sup 159}Gd como um potencial agente terapeutico contra cancer colorretal

    Energy Technology Data Exchange (ETDEWEB)

    Ferreira, Carolina de Aguiar

    2014-06-01

    Colorectal cancer (CRC) is a malignancy that affects large intestine and rectum, and it is the most common malignancy of the gastrointestinal tract, the third most commonly diagnosed type of cancer in the world and the second leading cause of cancer-related death in the United States. Nowadays, available therapeutic procedures for this type of cancer are limited and ineffective. Conventional radiotherapy is not an often used approach in the treatment of CRC due to the fact that peristaltic movements hamper the targeting of ionizing radiation and this type of treatment is used as adjuvant and palliative to control symptoms. Therefore, surgical intervention is the primary therapeutic choice against this disease. Researches based on the combination of radioisotopes and nanostructured carriers systems have demonstrated significant results in improving the selectivity action as well as reducing the radiation dose into healthy tissues. MCM-41 mesoporous silica nanoparticles have unique characteristics such as high surface area and well-defined pore diameters making these nanoparticles an ideal candidate of therapeutic agent carrier. Thus, the objective of this work is to synthesize and characterize MCM-41 mesoporous silica nanoparticles conjugated with yttrium-90 and gadolinium-159 and evaluate this system as a potential therapeutic agent. The nanoparticles were synthesized via sol-gel method. The sample was characterized using FTIR, SAXS, PCS, Zeta Potential analysis, Thermal analysis, CHN elemental analysis, nitrogen adsorption, scanning and transmission electron microscopy. The ability to incorporate Y{sup +3} and Gd{sup +3} ion was determined in vitro using different ratios (1:1, 1:3, 1:5 v/v) of YCL{sub 3} and Gd{sub 2}O{sub 3} and silica nanoparticles dispersed in saline, pH 7.4. The non-incorporated Y{sup +3} and Gd{sup +3} ions were removed by ultracentrifugation procedure and the concentration of ions in the supernatant was determined by ICP-AES. Cell viability

  8. Effect of green juice and their bioactive compounds on genotoxicity induced by alkylating agents in mice.

    Science.gov (United States)

    Fagundes, Gabriela Elibio; Damiani, Adriani Paganini; Borges, Gabriela Daminelli; Teixeira, Karina Oliveira; Jesus, Maiellen Martins; Daumann, Francine; Ramlov, Fernanda; Carvalho, Tiago; Leffa, Daniela Dimer; Rohr, Paula; Moraes De Andrade, Vanessa

    2017-01-01

    Kale juice (Brassica oleracea L. var. acephala D.C.) is a reliable source of dietary carotenoids and typically contains the highest concentrations of lutein (LT) and beta-carotene (BC) among green leafy vegetables. As a result of their antioxidant properties, dietary carotenoids are postulated to decrease the risk of disease occurrence, particularly certain cancers. The present study aimed to (1) examine the genotoxic and antigenotoxic activity of natural and commercially available juices derived from Brassica oleracea and (2) assess influence of LT or BC against DNA damage induced by alkylating agents such as methyl methanesulfonate (MS) or cyclophosphamide (CP) in vivo in mice. Male Swiss mice were divided into groups of 6 animals, which were treated with water, natural, or commercial Brassica oleraceae juices (kale), LT, BC, MMS, or CP. After treatment, DNA damage was determined in peripheral blood lymphocytes using the comet assay. Results demonstrated that none of the Brassica oleraceae juices or carotenoids produced genotoxic effects. In all examined cell types, kale juices or carotenoids inhibited DNA damage induced by MMS or CP administered either pre- or posttreatment by 50 and 20%, respectively. Under our experimental conditions, kale leaf juices alone exerted no marked genotoxic or clastogenic effects. However, a significant decrease in DNA damage induced by MMS or CP was noted. This effect was most pronounced in groups that received juices, rather than carotenoids, suggesting that the synergy among constituents present in the food matrix may be more beneficial than the action of single compounds. Data suggest that the antigenotoxic properties of kale juices may be of therapeutic importance.

  9. Bifunctional chelating agent for the design and development of site specific radiopharmaceuticals and biomolecule conjugation strategy

    Science.gov (United States)

    Katti, Kattesh V.; Prabhu, Kandikere R.; Gali, Hariprasad; Pillarsetty, Nagavara Kishore; Volkert, Wynn A.

    2003-10-21

    There is provided a method of labeling a biomolecule with a transition metal or radiometal in a site specific manner to produce a diagnostic or therapeutic pharmaceutical compound by synthesizing a P.sub.2 N.sub.2 -bifunctional chelating agent intermediate, complexing the intermediate with a radio metal or a transition metal, and covalently linking the resulting metal-complexed bifunctional chelating agent with a biomolecule in a site specific manner. Also provided is a method of synthesizing the --PR.sub.2 containing biomolecules by synthesizing a P.sub.2 N.sub.2 -bifunctional chelating agent intermediate, complexing the intermediate with a radiometal or a transition metal, and covalently linking the resulting radio metal-complexed bifunctional chelating agent with a biomolecule in a site specific manner. There is provided a therapeutic or diagnostic agent comprising a --PR.sub.2 containing biomolecule.

  10. Cranial nerve contrast using nerve-specific fluorophores improved by paired-agent imaging with indocyanine green as a control agent

    Science.gov (United States)

    Torres, Veronica C.; Vuong, Victoria D.; Wilson, Todd; Wewel, Joshua; Byrne, Richard W.; Tichauer, Kenneth M.

    2017-09-01

    Nerve preservation during surgery is critical because damage can result in significant morbidity. This remains a challenge especially for skull base surgeries where cranial nerves (CNs) are involved because visualization and access are particularly poor in that location. We present a paired-agent imaging method to enhance identification of CNs using nerve-specific fluorophores. Two myelin-targeting imaging agents were evaluated, Oxazine 4 and Rhodamine 800, and coadministered with a control agent, indocyanine green, either intravenously or topically in rats. Fluorescence imaging was performed on excised brains ex vivo, and nerve contrast was evaluated via paired-agent ratiometric data analysis. Although contrast was improved among all experimental groups using paired-agent imaging compared to conventional, solely targeted imaging, Oxazine 4 applied directly exhibited the greatest enhancement, with a minimum 3 times improvement in CNs delineation. This work highlights the importance of accounting for nonspecific signal of targeted agents, and demonstrates that paired-agent imaging is one method capable of doing so. Although staining, rinsing, and imaging protocols need to be optimized, these findings serve as a demonstration for the potential use of paired-agent imaging to improve contrast of CNs, and consequently, surgical outcome.

  11. MicroRNAs in cancer therapeutics: "from the bench to the bedside".

    Science.gov (United States)

    Monroig-Bosque, Paloma del C; Rivera, Carlos A; Calin, George A

    2015-01-01

    MicroRNAs (miRNAs) are non-coding RNA transcripts that regulate physiological processes by targeting proteins directly. Their involvement in research has been robust, and evidence of their regulative functions has granted them the title: master regulators of the human genome. In cancer, they are considered important therapeutic agents, due to the fact that their aberrant expression contributes to disease development, progression, metastasis, therapeutic response and patient overall survival. This has endeavored fields of biomedical sciences to invest in developing and exploiting miRNA-based therapeutics thoroughly. Herein we highlight relevant ongoing/open clinical trials involving miRNAs and cancer.

  12. EphB4 as a therapeutic target in mesothelioma

    International Nuclear Information System (INIS)

    Liu, Ren; Ferguson, Benjamin D; Zhou, Yue; Naga, Kranthi; Salgia, Ravi; Gill, Parkash S; Krasnoperov, Valery

    2013-01-01

    Malignant pleural mesothelioma (MPM) often develops decades following exposure to asbestos. Current best therapy produces a response in only half of patients, and the median survival with this therapy remains under a year. A search for novel targets and therapeutics is underway, and recently identified targets include VEGF, Notch, and EphB4-Ephrin-B2. Each of these targets has dual activity, promoting tumor cell growth as well as tumor angiogenesis. We investigated EphB4 expression in 39 human mesothelioma tissues by immunohistochemistry. Xenograft tumors established with human mesothelioma cells were treated with an EphB4 inhibitor (monomeric soluble EphB4 fused to human serum albumin, or sEphB4-HSA). The combinatorial effect of sEphB4-HSA and biologic agent was also studied. EphB4 was overexpressed in 72% of mesothelioma tissues evaluated, with 85% of epithelioid and 38% of sarcomatoid subtypes demonstrating overexpression. The EphB4 inhibitor sEphB4-HSA was highly active as a single agent to inhibit tumor growth, accompanied by tumor cell apoptosis and inhibition of PI3K and Src signaling. Combination of sEphB4-HSA and the anti-VEGF antibody (Bevacizumab) was superior to each agent alone and led to complete tumor regression. EphB4 is a potential therapeutic target in mesothelioma. Clinical investigation of sEphB4-HSA as a single agent and in combination with VEGF inhibitors is warranted

  13. The Promise of Neuroprotective Agents in Parkinson’s Disease

    Directory of Open Access Journals (Sweden)

    Judith ePotashkin

    2011-11-01

    Full Text Available Parkinson’s Disease is characterized by loss of dopamine neurons in the substantia nigra of the brain. Since there are limited treatment options for PD, neuroprotective agents are currently being tested as a means to slow disease progression. Agents targeting oxidative stress, mitochondrial dysfunction and inflammation are prime candidates for neuroprotection. This review identifies Rasagiline, Minocycline and creatine, as the most promising neuroprotective agents for PD, and they are all currently in phase III trials. Other agents possessing protective characteristics in delaying PD include stimulants, vitamins, supplements, and other drugs. Additionally, combination therapies also show benefits in slowing PD progression. The identification of neuroprotective agents for PD provides us with therapeutic opportunities for modifying the course of disease progression and, perhaps, reducing the risk of onset when preclinical biomarkers become available.

  14. Botanical polysaccharides: macrophage immunomodulation and therapeutic potential.

    Science.gov (United States)

    Schepetkin, Igor A; Quinn, Mark T

    2006-03-01

    Botanical polysaccharides exhibit a number of beneficial therapeutic properties, and it is thought that the mechanisms involved in these effects are due to the modulation of innate immunity and, more specifically, macrophage function. In this review, we summarize our current state of understanding of the macrophage modulatory effects of botanical polysaccharides isolated from a wide array of different species of flora, including higher plants, mushrooms, lichens and algae. Overall, the primary effect of botanical polysaccharides is to enhance and/or activate macrophage immune responses, leading to immunomodulation, anti-tumor activity, wound-healing and other therapeutic effects. Furthermore, botanical and microbial polysaccharides bind to common surface receptors and induce similar immunomodulatory responses in macrophages, suggesting that evolutionarily conserved polysaccharide structural features are shared between these organisms. Thus, the evaluation of botanical polysaccharides provides a unique opportunity for the discovery of novel therapeutic agents and adjuvants that exhibit beneficial immunomodulatory properties.

  15. Cell damage by bilirubin and light

    International Nuclear Information System (INIS)

    Granli, T.

    1993-01-01

    Large doses of light are given to newborns during phototherapy for hyperbilirubinemia. Tissues containing concentrations of bilirubin almost in the mM range may be subjected to irradiation. Therefore it is of interest to study cellular effects of light and bilirubin on cells. In order to select the optimal wavelength, possible detrimental effects of light on cells must be taken into consideration among a number of other factors. In this study cellular effects of selected wavelengths of blue-green light are compared. It is not clear whether cullular damage occurs in vivo during phototherapy of newborns. Since a possibility exists that some adverse effects are caused by light, one should choose wavelengths where these effects are minimal without loosing therapeutic efficiency. Todays knowledge of the photochemical mechanisms of phototherapy, indicates that short waved light with wavelengths below 450 nm has a low therapeutic effect. The data in this paper indicate that the cellular damage is most severe at short wavelengths, and these should be reduced to a minimum in the spectra of phototherapy lamps. Further studies of possible side effects of phototherapy should be made. 64 refs., 34 figs., 1 tab

  16. Protection Against Chemical Agent-Induced, Seizure-Related Neuronal Cell Death

    National Research Council Canada - National Science Library

    Ballough, Gerald P; Filbert, Margaret G

    2002-01-01

    .... While seizure-related brain damage can be prevented by administration of an anticonvulsant drug, battlefield conditions may preclude prompt administration of the convulsant antidote for nerve agents (CANA...

  17. Systemic use of tumor necrosis factor alpha as an anticancer agent

    Science.gov (United States)

    Roberts, Nicholas J.; Zhou, Shibin; Diaz, Luis A.; Holdhoff, Matthias

    2011-01-01

    Tumor necrosis factor-α (TNF-α) has been discussed as a potential anticancer agent for many years, however initial enthusiasm about its clinical use as a systemic agent was curbed due to significant toxicities and lack of efficacy. Combination of TNF-α with chemotherapy in the setting of hyperthermic isolated limb perfusion (ILP), has provided new insights into a potential therapeutic role of this agent. The therapeutic benefit from TNF-α in ILP is thought to be not only due to its direct anti-proliferative effect, but also due to its ability to increase penetration of the chemotherapeutic agents into the tumor tissue. New concepts for the use of TNF-α as a facilitator rather than as a direct actor are currently being explored with the goal to exploit the ability of this agent to increase drug delivery and to simultaneously reduce systemic toxicity. This review article provides a comprehensive overview on the published previous experience with systemic TNF-α. Data from 18 phase I and 10 phase II single agent as well as 18 combination therapy studies illustrate previously used treatment and dose schedules, response data as well as the most prominently observed adverse effects. Also discussed, based on recent preclinical data, is a potential future role of systemic TNF-α in combination with liposomal chemotherapy to facilitate increased drug uptake into tumors. PMID:22036896

  18. Preparation of 125IUdR and its evaluation in animal tumour model as a potential therapeutic agent

    International Nuclear Information System (INIS)

    Korde, A.; Venkatesh, M.; Banerjee, S.; Pillai, M.R.A.; Sarma, H.D.

    1998-01-01

    5-Iodo-2'-deoxyuridine or iodoxyuridine (IUdR), an analogue of thymidine, is taken up by the proliferating cells during DNA synthesis. Radioiodinated IUdR is a potential therapeutic agent since radiohalogenated thymidine analogues are used for in-vivo tumour targeting and Auger electrons from radionuclides such as 123 I and 125 I are very effective in cell destruction when internalised. 125 IUdR was prepared and studied for its suitability as an in-vivo tumour therapy agent. 125 IUdR was prepared both by direct iodination of 2'-deoxyuridine and iododemercuration of 5-chloromercury-2'-deoxyuridine. Radioiodination yields were between 60-80% at pH 7. Iododemercuration was preferred since with direct iodination poor yields were observed when high specific activity product was desired and also the purification procedure was lengthier. The identity of 125 IUdR was established by comparison of TLC and HPLC patterns with those of authentic IUdR. The purified 125 IUdR had radiochemical purity >95% and was stable for 20 days at 4 deg. C and for a week at 23 deg. C and 37 deg. C. Bio-uptake of 125 IUdR was studied by injecting the tracer in tumour bearing mice (Sarcoma S-180). The uptake in tumour cells was 4.28 +- 2.7% per gram at 3 h and 1.48 +- 0.19% at 24 h post injection. In-vivo deiodination of the product was observed as seen by the uptake of the activity in the thyroid. About 40% the activity from all other organs was excreted in 70 h. The optimum time for injection of the tracer for therapy was studied by observing the delay in tumour growth and survival rate in mice injected at 0,3,9 and 12 days after tumour induction. Injection of the tracer on the third day was found to be the most beneficial for retardation of tumour growth, while injection of the activity on the zeroth and ninth day had no effect. (author)

  19. Poly (ADP-ribose) catabolism in mammalian cells exposed to DNA-damaging agents

    International Nuclear Information System (INIS)

    Alvarez-Gonzalez, R.; Althaus, F.R.

    1989-01-01

    DNA damage inflicted by the alkylating agens N-methyl-N-nitro-N-nitrosoquanidine, or by UV stimulated the catabolism of protein-bound poly (ADP-ribose) in the chromatin of cultured hepatocytes. The stimulation was highest at the largest doses of DNA-damaging treatment. As a consequence, the half-life of ADP-ribosyl polymers may drop to less than 41 s. This rapid turnover contrasts with the slow catabolism of a constitutive fraction of polymers exhibiting a half-life of 7.7 h. These data suggest that post-incisional stimulation of poly (ADP-ribose) biosynthesis in DNA-excision repair is coupled with an adaptation of poly (ADP-ribose) catabolism in mammalian cells. (Author). 37 refs.; 3 figs

  20. Therapeutic advancement of chronic lymphocytic leukemia

    Directory of Open Access Journals (Sweden)

    Lu Kang

    2012-09-01

    Full Text Available Abstract Despite the combinations of chemotherapy with monoclonal antibodies have further improved response rates, chronic lymphocytic leukemia (CLL remains an incurable disease with an extremely variable course. This article reviews the ongoing clinical advances in the treatment of CLL in both previously untreated and relapsed disease and focuses on the benefit of different therapeutic strategies, the most effective therapy combinations and the potential activity of novel agents. Novel agents and combination therapies have been investigated by several studies in both the upfront and relapsed setting, particularly for patients with 17p deletion, TP53 mutation and fludarabine-refractory CLL. While these agents and combination therapies have improved initial response rates, ongoing studies are continued to determine and improve the efficacy and safety. Despite advancements in the treatment of CLL have led to high response rates, allogeneic hematopoietic stem cell transplantation (allo-HSCT remains the only curative option and reduced-intensity conditioning (RIC allo-HSCT must be strongly considered whenever feasible. As such, ongoing studies of these agents and other novel approaches in clinical development are needed to expand and improve treatment options for CLL patients.

  1. Engineered Polymer-Based Nanomaterials for Diagnostic, Therapeutic and Theranostic Applications.

    Science.gov (United States)

    Parisi, Ortensia Ilaria; Scrivano, Luca; Sinicropi, Maria Stefania; Picci, Nevio; Puoci, Francesco

    2016-01-01

    Nanomedicine can be defined as the medical application of molecular nanotechnology and it plays a key role and pharmaceutical research and development, especially related to cancer prevention, monitoring, diagnosis and treatment. In this context, nanomaterials are attracting significant research interest due to their abilities to stay in the blood for long time, accumulate in pathological sites including tumors or inflammatory areas via the enhanced permeability and retention (EPR) effect, and facilitate targeted delivery of specific therapeutic agents. In the last decades, considerable attention was attracted by the development of nano-sized carriers, based on natural or synthetic polymers, able to provide the controlled release of anticancer drugs in the aim to overcome the drawbacks associated to the conventional chemotherapy. Furthermore, when loaded with imaging agents, this kind of systems offers the opportunity to exploit optical or magnetic resonance imaging (MRI) in cancer diagnosis. Polymeric materials are characterized by several functionalities where both therapeutic and imaging components, and also targeting moieties, can be attached for simultaneous targeted therapy and imaging providing innovative platforms defined as theranostic agents with a great potential in monitoring and treatment of cancer.

  2. Resveratrol as a Therapeutic Agent for Alzheimer’s Disease

    Directory of Open Access Journals (Sweden)

    Teng Ma

    2014-01-01

    Full Text Available Alzheimer’s disease (AD is the most common cause of dementia, but there is no effective therapy till now. The pathogenic mechanisms of AD are considerably complex, including Aβ accumulation, tau protein phosphorylation, oxidative stress, and inflammation. Exactly, resveratrol, a polyphenol in red wine and many plants, is indicated to show the neuroprotective effect on mechanisms mostly above. Recent years, there are numerous researches about resveratrol acting on AD in many models, both in vitro and in vivo. However, the effects of resveratrol are limited by its pool bioavailability; therefore researchers have been trying a variety of methods to improve the efficiency. This review summarizes the recent studies in cell cultures and animal models, mainly discusses the molecular mechanisms of the neuroprotective effects of resveratrol, and thus investigates the therapeutic potential in AD.

  3. Targeting reactive nitrogen species: a promising therapeutic strategy for cerebral ischemia-reperfusion injury.

    Science.gov (United States)

    Chen, Xing-miao; Chen, Han-sen; Xu, Ming-jing; Shen, Jian-gang

    2013-01-01

    Ischemic stroke accounts for nearly 80% of stroke cases. Recanalization with thrombolysis is a currently crucial therapeutic strategy for re-building blood supply, but the thrombolytic therapy often companies with cerebral ischemia-reperfusion injury, which are mediated by free radicals. As an important component of free radicals, reactive nitrogen species (RNS), including nitric oxide (NO) and peroxynitrite (ONOO(-)), play important roles in the process of cerebral ischemia-reperfusion injury. Ischemia-reperfusion results in the production of nitric oxide (NO) and peroxynitrite (ONOO(-)) in ischemic brain, which trigger numerous molecular cascades and lead to disruption of the blood brain barrier and exacerbate brain damage. There are few therapeutic strategies available for saving ischemic brains and preventing the subsequent brain damage. Recent evidence suggests that RNS could be a therapeutic target for the treatment of cerebral ischemia-reperfusion injury. Herein, we reviewed the recent progress regarding the roles of RNS in the process of cerebral ischemic-reperfusion injury and discussed the potentials of drug development that target NO and ONOO(-) to treat ischemic stroke. We conclude that modulation for RNS level could be an important therapeutic strategy for preventing cerebral ischemia-reperfusion injury.

  4. Immunotherapeutics in Pediatric Autoimmune Central Nervous System Disease: Agents and Mechanisms.

    Science.gov (United States)

    Nosadini, Margherita; Sartori, Stefano; Sharma, Suvasini; Dale, Russell C

    2017-08-01

    Beyond the major advances produced by careful clinical-radiological phenotyping and biomarker development in autoimmune central nervous system disorders, a comprehensive knowledge of the range of available immune therapies and a deeper understanding of their action should benefit therapeutic decision-making. This review discusses the agents used in neuroimmunology and their mechanisms of action. First-line treatments typically include corticosteroids, intravenous immunoglobulin, and plasmapheresis, while for severe disease second-line "induction" agents such as rituximab or cyclophosphamide are used. Steroid-sparing agents such as mycophenolate, azathioprine, or methotrexate are often used in potentially relapsing or corticosteroid-dependent diseases. Lessons from adult neuroimmunology and rheumatology could be translated into pediatric autoimmune central nervous system disease in the future, including the potential utility of monoclonal antibodies targeting lymphocytes, adhesion molecules for lymphocytic migration, cytokines or their receptors, or complement. Finally, many agents used in other fields have multiple mechanisms of action, including immunomodulation, with potential usefulness in neuroimmunology, such as antibiotics, psychotropic drugs, probiotics, gut health, and ketogenic diet. All currently accepted and future potential agents have adverse effects, which can be severe; therefore, a "risk-versus-benefit" determination should guide therapeutic decision-making. Copyright © 2017 Elsevier Inc. All rights reserved.

  5. (WASHINGTON, DC) A FLUORESCENCE BASED ASSAY FOR DNA DAMAGE INDUCED BY TOXIC INDUSTRIAL CHEMICALS

    Science.gov (United States)

    Numerous natural and man-made agents are continuously released into the environment due to human activity. Many of these agents cause irreversible damage to the normal biological functions leading to morbidity and mortality in the exposed organisms. The possibility of deliberat...

  6. Cellular response to alkylating agent MNNG is impaired in STAT1-deficients cells.

    Science.gov (United States)

    Ah-Koon, Laurent; Lesage, Denis; Lemadre, Elodie; Souissi, Inès; Fagard, Remi; Varin-Blank, Nadine; Fabre, Emmanuelle E; Schischmanoff, Olivier

    2016-10-01

    The SN 1 alkylating agents activate the mismatch repair system leading to delayed G2 /M cell cycle arrest and DNA repair with subsequent survival or cell death. STAT1, an anti-proliferative and pro-apoptotic transcription factor is known to potentiate p53 and to affect DNA-damage cellular response. We studied whether STAT1 may modulate cell fate following activation of the mismatch repair system upon exposure to the alkylating agent N-methyl-N'-nitro-N-nitrosoguanidine (MNNG). Using STAT1-proficient or -deficient cell lines, we found that STAT1 is required for: (i) reduction in the extent of DNA lesions, (ii) rapid phosphorylation of T68-CHK2 and of S15-p53, (iii) progression through the G2 /M checkpoint and (iv) long-term survival following treatment with MNNG. Presence of STAT1 is critical for the formation of a p53-DNA complex comprising: STAT1, c-Abl and MLH1 following exposure to MNNG. Importantly, presence of STAT1 allows recruitment of c-Abl to p53-DNA complex and links c-Abl tyrosine kinase activity to MNNG-toxicity. Thus, our data highlight the important modulatory role of STAT1 in the signalling pathway activated by the mismatch repair system. This ability of STAT1 to favour resistance to MNNG indicates the targeting of STAT1 pathway as a therapeutic option for enhancing the efficacy of SN1 alkylating agent-based chemotherapy. © 2016 The Authors. Journal of Cellular and Molecular Medicine published by John Wiley & Sons Ltd and Foundation for Cellular and Molecular Medicine.

  7. Sensitization of melanoma cells to alkylating agent-induced DNA damage and cell death via orchestrating oxidative stress and IKKβ inhibition

    Directory of Open Access Journals (Sweden)

    Anfernee Kai-Wing Tse

    2017-04-01

    Full Text Available Nitrosourea represents one of the most active classes of chemotherapeutic alkylating agents for metastatic melanoma. Treatment with nitrosoureas caused severe systemic side effects which hamper its clinical use. Here, we provide pharmacological evidence that reactive oxygen species (ROS induction and IKKβ inhibition cooperatively enhance nitrosourea-induced cytotoxicity in melanoma cells. We identified SC-514 as a ROS-inducing IKKβ inhibitor which enhanced the function of nitrosoureas. Elevated ROS level results in increased DNA crosslink efficiency triggered by nitrosoureas and IKKβ inhibition enhances DNA damage signals and sensitizes nitrosourea-induced cell death. Using xenograft mouse model, we confirm that ROS-inducing IKKβ inhibitor cooperates with nitrosourea to reduce tumor size and malignancy in vivo. Taken together, our results illustrate a new direction in nitrosourea treatment, and reveal that the combination of ROS-inducing IKKβ inhibitors with nitrosoureas can be potentially exploited for melanoma therapy.

  8. Therapeutic ratio and fractionation in cancer of the lung

    International Nuclear Information System (INIS)

    Cox, J.D.; Bauer, M.

    1988-01-01

    Bronchopulmonary carcinomas have long been considered among the most frustrating problems in radiation oncology. In spite of the reasonably favorable results reported over 30 years ago with conventional X-irradiation of patients with operable carcinoma of the lung, the patients usually referred for radiation therapy with unresectable tumors permit few opportunities for successful treatment and thus lead to a general nihilism about this disease. The potential damage that can occur from radiation therapy to the normal lung can be life-threatening. Such damage was thought, erroneously, to be increased dramatically with even moderately high doses, e.g.; more than 50 Gy in 5 weeks. Therefore, few attempts were made to deliver the same high doses of radiations that would be considered mandatory for epithelial tumors of other locations such as the upper respiratory and digestive tract or the female genital tract. The therapeutic ratio was altered in an unfavorable direction with the use of small numbers of large fractions. Based on the earliest RTOG studies of carcinoma of the lung, the therapeutic ratio is at an acceptable level with 60 Gy in 30 fractions of 2.0 Gy in 6 weeks. It is encouraging that there is no evidence of an increased rate of morbidity in the hyperfractionation trials of the RTOG. The data are too preliminary with regard to therapeutic effect to know if there will truly be an increase in therapeutic ratio. It was evident that 12-24 months of follow-up are necessary before definitive answers are available

  9. Sensitization of gastric cancer cells to alkylating agents by glaucocalyxin B via cell cycle arrest and enhanced cell death.

    Science.gov (United States)

    Ur Rahman, Muhammad Saif; Zhang, Ling; Wu, Lingyan; Xie, Yuqiong; Li, Chunchun; Cao, Jiang

    2017-01-01

    Severe side effects are major problems with chemotherapy of gastric cancer (GC). These side effects can be reduced by using sensitizing agents in combination with therapeutic drugs. In this study, the low/nontoxic dosage of glaucocalyxin B (GLB) was used with other DNA linker agents mitomycin C (MMC), cisplatin (DDP), or cyclophosphamide (CTX) to treat GC cells. Combined effectiveness of GLB with drugs was determined by proliferation assay. The molecular mechanisms associated with cell proliferation, migration, invasion, cell cycle, DNA repair/replication, apoptosis, and autophagy were investigated by immunoblotting for key proteins involved. Cell cycle and apoptosis analysis were performed by flow cytometry. Reactive oxygen species level was also examined for identification of its role in apoptosis. Proliferation assay revealed that the addition of 5 µM GLB significantly sensitizes gastric cancer SGC-7901 cells to MMC, DDP, and CTX by decreasing half-maximal inhibitory concentration (IC 50 ) by up to 75.40%±5%, 45.10%±5%, and 52.10%±5%, respectively. GLB + drugs decreased the expression level of proteins involved in proliferation and migration, suggesting the anticancer potential of GLB + drugs. GLB + MMC, GLB + CTX, and GLB + DDP arrest the cells in G 0 /G 1 and G 1 /S phase, respectively, which may be the consequence of significant decrease in the level of enzymes responsible for DNA replication and telomerase shortening. Combined use of GLB with these drugs also induces DNA damage and apoptosis by activating caspase/PARP pathways and increased production of reactive oxygen species and increased autophagy in GC cells. GLB dosage sensitizes GC cells to the alkylating agents via arresting the cell cycle and enhancing cell death. This is of significant therapeutic importance in the reduction of side effects associated with these drugs.

  10. Superparamagnetic Bifunctional Bisphosphonates Nanoparticles: A Potential MRI Contrast Agent for Osteoporosis Therapy and Diagnostic

    Directory of Open Access Journals (Sweden)

    Y. Lalatonne

    2010-01-01

    Full Text Available A bone targeting nanosystem is reported here which combined magnetic contrast agent for Magnetic Resonance Imaging (MRI and a therapeutic agent (bisphosphonates into one drug delivery system. This new targeting nanoplatform consists of superparamagnetic γFe2O3 nanoparticles conjugated to 1,5-dihydroxy-1,5,5-tris-phosphono-pentyl-phosphonic acid (di-HMBPs molecules with a bisphosphonate function at the outer of the nanoparticle surface for bone targeting. The as-synthesized nanoparticles were evaluated as a specific MRI contrast agent by adsorption study onto hydroxyapatite and MRI measurment. The strong adsorption of the bisphosphonates nanoparticles to hydroxyapatite and their use as MRI T2∗ contrast agent were demonstrated. Cellular tests performed on human osteosarcoma cells (MG63 show that γFe2O3@di-HMBP hybrid nanomaterial has no citoxity effect in cell viability and may act as a diagnostic and therapeutic system.

  11. Nanometric agents in the service of neuroscience: Manipulation of neuronal growth and activity using nanoparticles.

    Science.gov (United States)

    Polak, Pazit; Shefi, Orit

    2015-08-01

    Nerve regeneration and recovery could provide great therapeutic benefits for individuals suffering from nerve damage post trauma or degenerative diseases. However, manipulation of nerves presents a huge challenge for neuroscientists and is not yet clinically feasible. In recent years, nanoparticles have emerged as novel effective agents for control of neuronal growth and behavior. Nanoparticles may facilitate the needed nerve manipulation abilities for therapeutic and diagnostic purposes including within the brain. This review aims at presenting the currently available literature regarding the interactions between inorganic nanoparticles and neurons. A wide range of nanoparticles are presented, including gold, iron oxide, cerium oxide, nanotubes and quantum-dots. The nanoparticles enhance neuronal differentiation and survival, direct growth and regulate electrical activity. The studies are summarized in a concise table, arranged by the function and type of nanoparticle. The latest studies present a novel interdisciplinary approach, which could be harnessed for clinical applications in nanomedicine. Nerve regeneration remains the Holy Grail for patients with neuron loss. Nonetheless, this goal has not been realized in clinical setting thus far. In this article, the authors present a comprehensive review on various nanoparticle-based approaches, in both diagnosis and therapy, which should stimulate and generate more research ideas to the advancement in this field. Copyright © 2015 Elsevier Inc. All rights reserved.

  12. Therapeutic strategies in the treatment of periodontitis

    Directory of Open Access Journals (Sweden)

    Liljana Bogdanovska

    2012-04-01

    Full Text Available Periodontitis is a chronic inflammatory process which affects the tooth - supporting structures of the teeth. The disease is initiated by subgingival periopathogenic bacteria in susceptible periodontal sites. The host immune response towards periodontal pathogens helps to sustain periodontal disease and eventual alveolar bone loss. Although scaling and root planing is the standard treatment modality for periodontitis, it suffers from several drawbacks such as the inability to reach the base of deep pockets and doesn’t arrest migration of periodontal pathogens from other sites in the oral cavity. In order to overcome the limitations of scaling and root planning, adjunctive chemotherapeutics and host modulatory agents to the treatment are used. These therapeutic agents show substantial beneficial effects when compared to scaling and root planning alone. This review will cover an update on chemotherapeutic and past and future host immune modulatory agents used adjunctively to treat and manage periodontal diseases.

  13. Therapeutic Vaccination for HPV Induced Cervical Cancers

    Directory of Open Access Journals (Sweden)

    Joeli A. Brinkman

    2007-01-01

    Full Text Available Cervical Cancer is the second leading cause of cancer–related deaths in women worldwide and is associated with Human Papillomavirus (HPV infection, creating a unique opportunity to treat cervical cancer through anti-viral vaccination. Although a prophylactic vaccine may be available within a year, millions of women, already infected, will continue to suffer from HPV-related disease, emphasizing the need to develop therapeutic vaccination strategies. A majority of clinical trials examining therapeutic vaccination have shown limited efficacy due to examining patients with more advanced-stage cancer who tend to have decreased immune function. Current trends in clinical trials with therapeutic agents examine patients with pre-invasive lesions in order to prevent invasive cervical cancer. However, longer follow-up is necessary to correlate immune responses to lesion regression. Meanwhile, preclinical studies in this field include further exploration of peptide or protein vaccination, and the delivery of HPV antigens in DNA-based vaccines or in viral vectors. As long as pre-clinical studies continue to advance, the prospect of therapeutic vaccination to treat existing lesions seem good in the near future. Positive consequences of therapeutic vaccination would include less disfiguring treatment options and fewer instances of recurrent or progressive lesions leading to a reduction in cervical cancer incidence.

  14. Therapeutic peptides for cancer therapy. Part I - peptide inhibitors of signal transduction cascades.

    Science.gov (United States)

    Bidwell, Gene L; Raucher, Drazen

    2009-10-01

    Therapeutic peptides have great potential as anticancer agents owing to their ease of rational design and target specificity. However, their utility in vivo is limited by low stability and poor tumor penetration. The authors review the development of peptide inhibitors with potential for cancer therapy. Peptides that inhibit signal transduction cascades are discussed. The authors searched Medline for articles concerning the development of therapeutic peptides and their delivery. Given our current knowledge of protein sequences, structures and interaction interfaces, therapeutic peptides that inhibit interactions of interest are easily designed. These peptides are advantageous because they are highly specific for the interaction of interest, and they are much more easily developed than small molecule inhibitors of the same interactions. The main hurdle to application of peptides for cancer therapy is their poor pharmacokinetic and biodistribution parameters. Therefore, successful development of peptide delivery vectors could potentially make possible the use of this new and very promising class of anticancer agents.

  15. Acoustically active lipospheres containing paclitaxel: a new therapeutic ultrasound contrast agent.

    Science.gov (United States)

    Unger, E C; McCreery, T P; Sweitzer, R H; Caldwell, V E; Wu, Y

    1998-12-01

    Paclitaxel-carrying lipospheres (MRX-552) were developed and evaluated as a new ultrasound contrast agent for chemotherapeutic drug delivery. Paclitaxel was suspended in soybean oil and added to an aqueous suspension of phospholipids in vials. The headspace of the vials was replaced with perfluorobutane gas; the vials were sealed, and they were agitated at 4200 rpm on a shaking device. The resulting lipospheres containing paclitaxel were studied for concentration, size, acute toxicity in mice, and acoustic activity and drug release with ultrasound. Lipospheres containing sudan black dye were produced to demonstrate the acoustically active liposphere (AAL)-ultrasound release concept. Acoustically active lipospheres containing paclitaxel had a mean particle count of approximately 1 x 10(9) particles per mL and a mean size of 2.9 microns. Acute toxicity studies in mice showed a 10-fold reduction in toxicity for paclitaxel in AALs compared with free paclitaxel. The AALs reflected ultrasound as a contrast agent. Increasing amounts of ultrasound energy selectively ruptured the AALs and released the paclitaxel. Acoustically active lipospheres represent a new class of acoustically active drug delivery vehicles. Future studies will assess efficacy of AALs for ultrasound-mediated drug delivery.

  16. Sphingosine 1-phosphate (S1P) signalling: Role in bone biology and potential therapeutic target for bone repair.

    Science.gov (United States)

    Sartawi, Ziad; Schipani, Ernestina; Ryan, Katie B; Waeber, Christian

    2017-11-01

    The lipid mediator sphingosine 1-phosphate (S1P) affects cellular functions in most systems. Interest in its therapeutic potential has increased following the discovery of its G protein-coupled receptors and the recent availability of agents that can be safely administered in humans. Although the role of S1P in bone biology has been the focus of much less research than its role in the nervous, cardiovascular and immune systems, it is becoming clear that this lipid influences many of the functions, pathways and cell types that play a key role in bone maintenance and repair. Indeed, S1P is implicated in many osteogenesis-related processes including stem cell recruitment and subsequent differentiation, differentiation and survival of osteoblasts, and coupling of the latter cell type with osteoclasts. In addition, S1P's role in promoting angiogenesis is well-established. The pleiotropic effects of S1P on bone and blood vessels have significant potential therapeutic implications, as current therapeutic approaches for critical bone defects show significant limitations. Because of the complex effects of S1P on bone, the pharmacology of S1P-like agents and their physico-chemical properties, it is likely that therapeutic delivery of S1P agents will offer significant advantages compared to larger molecular weight factors. Hence, it is important to explore novel methods of utilizing S1P agents therapeutically, and improve our understanding of how S1P and its receptors modulate bone physiology and repair. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. Damage and functional recovery of the mouse retina after exposure to genotoxic agents

    International Nuclear Information System (INIS)

    Vinogradova, Yu.V.; Tronov, V.A.; Lyakhova, K.N.; Ostrovskij, M.A.

    2013-01-01

    As is known, the mature retina is characterized by high radiation resistance. We showed earlier that ionizing radiation at a dose of ≥25 Gy and the chemical genotoxic agent methylnitrosourea (MNU) in a concentration of ≥60 mg/kg induce acute retinal degeneration, combined with proapoptotic protein expression. The process has a high genotoxic threshold, below which no degeneration signs were traced. The aim of this work was to study the damaging effect of ionizing radiation and MNU on the functional activity of the retina and its ability to recover after exposure to these genotoxicants. The functional activity of the mouse retina was evaluated with electroretinograms (ERG). In parallel, morphological changes in the retina were controlled, and the TUNEL detection of the death of its cell elements was performed. It has been shown that gamma rays or accelerated proton irradiation below 15 Gy cause no structural or functional changes in the mouse retina, which confirms the mature retina's high radiation resistance. Irradiation with a higher dose of 25 Gy leads to photoreceptor layer destruction. This goes along with an increase in the number of the TUNEL-positive photoreceptors, among which are cells with fragmented nuclei, which are typical of apoptosis. MNU in a concentration of 70 mg/kg caused the irreversible loss of the retina's physiological activity, and the morphological degeneration of photoreceptors and their mass death. In a concentration of 35 mg/kg, however, MNU had no cytotoxic effect on the retina. Moreover, this dose caused a reversible ERG amplitude decrease. Also, adaptive response was observed in the retina, which became apparent after two consecutive MNU injections - first, at a dose of 17 mg/kg; then, at a cytotoxic dose of 70 mg/kg. These results point to the possibility of the neurohormesis effect, which was described concerning the retina's exposure to ionizing radiation and some chemicals.

  18. Star-Shaped Polypeptides: Synthesis and Opportunities for Delivery of Therapeutics.

    Science.gov (United States)

    Byrne, Mark; Murphy, Robert; Kapetanakis, Antonios; Ramsey, Joanne; Cryan, Sally-Ann; Heise, Andreas

    2015-09-17

    Significant advances in the synthesis of polypeptides by N-carboxyanhydride (NCA) polymerisation over the last decade have enabled the design of advanced polypeptide architectures such as star-shaped polypeptides. These materials combine the functionality offered by amino acids with the flexibility of creating stable nanoparticles with adjustable cargo space for therapeutic delivery. This review highlights recent advances in the synthesis of star polypeptides by NCA polymerisation followed by a critical review of the applications of this class of polymer in the delivery of therapeutic agents. This includes examples of traditional small-molecule drugs as well as the emerging class of biologics such as genetic therapeutics (gene delivery). © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Ultraviolet-B lethal damage on Pseudomonas aeruginosa

    International Nuclear Information System (INIS)

    Degiorgi, C.F.; Fernandez, R.O.; Pizarro, R.A.

    1996-01-01

    Pseudomonas aeruginosa has shown an increased sensitivity compared with that of Escherichia coli and Enterobacter cloacae, when they were exposed to 0.4 kJ/m2 of ultraviolet-B radiation. The rapid decay in cell viability observed in Pseudomonas aeruginosa after the irradiation was influenced by factors such as culture media and the presence of pyocyanine during the irradiation. The radioinduced lethal damage could be prevented by photoreactivating treatment, indicating that pyrimidine dimer formation was the mechanism causing bacterial death. The results indicate that several environmental conditions may act as protective agents against ultraviolet-B-induced damage

  20. Quantitative Phosphoproteomics Reveals Wee1 Kinase as a Therapeutic Target in a Model of Proneural Glioblastoma.

    Science.gov (United States)

    Lescarbeau, Rebecca S; Lei, Liang; Bakken, Katrina K; Sims, Peter A; Sarkaria, Jann N; Canoll, Peter; White, Forest M

    2016-06-01

    Glioblastoma (GBM) is the most common malignant primary brain cancer. With a median survival of about a year, new approaches to treating this disease are necessary. To identify signaling molecules regulating GBM progression in a genetically engineered murine model of proneural GBM, we quantified phosphotyrosine-mediated signaling using mass spectrometry. Oncogenic signals, including phosphorylated ERK MAPK, PI3K, and PDGFR, were found to be increased in the murine tumors relative to brain. Phosphorylation of CDK1 pY15, associated with the G2 arrest checkpoint, was identified as the most differentially phosphorylated site, with a 14-fold increase in phosphorylation in the tumors. To assess the role of this checkpoint as a potential therapeutic target, syngeneic primary cell lines derived from these tumors were treated with MK-1775, an inhibitor of Wee1, the kinase responsible for CDK1 Y15 phosphorylation. MK-1775 treatment led to mitotic catastrophe, as defined by increased DNA damage and cell death by apoptosis. To assess the extensibility of targeting Wee1/CDK1 in GBM, patient-derived xenograft (PDX) cell lines were also treated with MK-1775. Although the response was more heterogeneous, on-target Wee1 inhibition led to decreased CDK1 Y15 phosphorylation and increased DNA damage and apoptosis in each line. These results were also validated in vivo, where single-agent MK-1775 demonstrated an antitumor effect on a flank PDX tumor model, increasing mouse survival by 1.74-fold. This study highlights the ability of unbiased quantitative phosphoproteomics to reveal therapeutic targets in tumor models, and the potential for Wee1 inhibition as a treatment approach in preclinical models of GBM. Mol Cancer Ther; 15(6); 1332-43. ©2016 AACR. ©2016 American Association for Cancer Research.

  1. Efficacy of ATR inhibitors as single agents in Ewing sarcoma

    DEFF Research Database (Denmark)

    Nieto-Soler, Maria; Morgado-Palacin, Isabel; Lafarga, Vanesa

    2016-01-01

    Ewing sarcomas (ES) are pediatric bone tumors that arise from a driver translocation, most frequently EWS/FLI1. Current ES treatment involves DNA damaging agents, yet the basis for the sensitivity to these therapies remains unknown. Oncogene-induced replication stress (RS) is a known source...... efficacy in ES xenografts as single agents. Expression of EWS/FLI1 or EWS/ERG oncogenic translocations sensitizes non-ES cells to ATR inhibitors. Our data shed light onto the sensitivity of ES to genotoxic agents, and identify ATR inhibitors as a potential therapy for Ewing Sarcomas....

  2. Novel compounds for the treatment of Duchenne muscular dystrophy: emerging therapeutic agents

    Directory of Open Access Journals (Sweden)

    Steve D Wilton

    2011-03-01

    Full Text Available Steve D Wilton, Sue FletcherCentre for Neuromuscular and Neurological Disorders, University of Western Australia, Crawley, Perth, WA, AustraliaAbstract: The identification of dystrophin and the causative role of mutations in this gene in Duchenne and Becker muscular dystrophies (D/BMD was expected to lead to timely development of effective therapies. Despite over 20 years of research, corticosteroids remain the only available pharmacological treatment for DMD, although significant benefits and extended life have resulted from advances in the clinical care and management of DMD individuals. Effective treatment of DMD will require dystrophin restitution in skeletal, cardiac, and smooth muscles and nonmuscle tissues; however, modulation of muscle loss and regeneration has the potential to play an important role in altering the natural history of DMD, particularly in combination with other treatments. Emerging biological, molecular, and small molecule therapeutics are showing promise in ameliorating this devastating disease, and it is anticipated that regulatory environments will need to display some flexibility in order to accommodate the new treatment paradigms.Keywords: Duchenne muscular dystrophy, molecular therapeutics, small molecules

  3. Inhibitors of poly (ADP-ribose) polymerase and their enhancement of alkylating agent cytotoxicity in vivo

    International Nuclear Information System (INIS)

    Horsman, M.R.; Brown, D.M.; Hirst, D.G.; Brown, J.M.

    1984-01-01

    The chromosomal enzyme poly (ADP-ribose) polymerase (ADPRP) is involved in the repair of DNA damage caused by both ionizing radiation and alkylating agents. The authors have shown that certain inhibitors of this enzyme decrease potentially lethal damage repair after X-rays. The aim of the present study was to investigate the possible enhancement of alkylating agent damage in vivo by several of these ADPRP inhibitors. 3-aminobenzamide (200 mg/kg), caffeine (200 mg/kg), or nicotinamide (1000 mg/kg) given to RIF-1-tumor-bearing mice immediately before a dose of melphalan (L-PAM) (8 mg/kg) produced enhancement of tumor response as demonstrated by an in vivo in vitro tumor excision assay. Caffeine and nicotinamide provided the greatest enhancement of L-PAM cytotoxicity with at least a 100-fold increase in killing. Data are presented on the mechanism by which these drugs and other more potent inhibitors enhance the tumor cell killing by L-PAM and other alkylating agents

  4. Effects of treatment with antimicrobial agents on the human colonic microflora

    OpenAIRE

    Rafii, Fatemeh

    2008-01-01

    Fatemeh Rafii, John B Sutherland, Carl E CernigliaDivision of Microbiology, National Center for Toxicological Research, FDA, Jefferson, AR, USAAbstract: Antimicrobial agents are the most valuable means available for treating bacterial infections. However, the administration of therapeutic doses of antimicrobial agents to patients is a leading cause of disturbance of the normal gastrointestinal microflora. This disturbance results in diminishing the natural defense mechanisms provided by the c...

  5. Mechanisms of Sensorineural Cell Damage, Death and Survival in the Cochlea

    Directory of Open Access Journals (Sweden)

    Allen Frederic Ryan

    2015-04-01

    Full Text Available The majority of acquired hearing loss, including presbycusis, is caused by irreversible damage to the sensorineural tissues of the cochlea. This article reviews the intracellular mechanisms that contribute to sensorineural damage in the cochlea, as well as the survival signaling pathways that can provide endogenous protection and tissue rescue. These data have primarily been generated in hearing loss not directly related to age. However, there is evidence that similar mechanisms operate in presbycusis. Moreover, accumulation of damage from other causes can contribute to age-related hearing loss. Potential therapeutic interventions to balance opposing but interconnected cell damage and survival pathways, such as antioxidants, anti-apoptotics, and pro-inflammatory cytokine inhibitors, are also discussed.

  6. Imaging enabled platforms for development of therapeutics

    Science.gov (United States)

    Celli, Jonathan; Rizvi, Imran; Blanden, Adam R.; Evans, Conor L.; Abu-Yousif, Adnan O.; Spring, Bryan Q.; Muzikansky, Alona; Pogue, Brian W.; Finkelstein, Dianne M.; Hasan, Tayyaba

    2011-03-01

    Advances in imaging and spectroscopic technologies have enabled the optimization of many therapeutic modalities in cancer and noncancer pathologies either by earlier disease detection or by allowing therapy monitoring. Amongst the therapeutic options benefiting from developments in imaging technologies, photodynamic therapy (PDT) is exceptional. PDT is a photochemistry-based therapeutic approach where a light-sensitive molecule (photosensitizer) is activated with light of appropriate energy (wavelength) to produce reactive molecular species such as free radicals and singlet oxygen. These molecular entities then react with biological targets such as DNA, membranes and other cellular components to impair their function and lead to eventual cell and tissue death. Development of PDT-based imaging also provides a platform for rapid screening of new therapeutics in novel in vitro models prior to expensive and labor-intensive animal studies. In this study we demonstrate how an imaging platform can be used for strategizing a novel combination treatment strategy for multifocal ovarian cancer. Using an in vitro 3D model for micrometastatic ovarian cancer in conjunction with quantitative imaging we examine dose and scheduling strategies for PDT in combination with carboplatin, a chemotherapeutic agent presently in clinical use for management of this deadly form of cancer.

  7. Differential expression of the klf6 tumor suppressor gene upon cell damaging treatments in cancer cells

    International Nuclear Information System (INIS)

    Gehrau, Ricardo C.; D'Astolfo, Diego S.; Andreoli, Veronica; Bocco, Jose L.; Koritschoner, Nicolas P.

    2011-01-01

    The mammalian Krueppel-like factor 6 (KLF6) is involved in critical roles such as growth-related signal transduction, cell proliferation and differentiation, development, apoptosis and angiogenesis. Also, KLF6 appears to be an emerging key factor during cancer development and progression. Its expression is thoroughly regulated by several cell-damaging stimuli. DNA damaging agents at lethal concentrations induce a p53-independent down-regulation of the klf6 gene. To investigate the impact of external stimuli on human klf6 gene expression, its mRNA level was analyzed using a cancer cell line profiling array system, consisting in an assortment of immobilized cDNAs from multiple cell lines treated with several cell-damaging agents at growth inhibitory concentrations (IC 50 ). Cell-damaging agents affected the klf6 expression in 62% of the cDNA samples, though the expression pattern was not dependent on the cell origin type. Interestingly, significant differences (p 50 concentrations of physical and chemical stimuli in a p53-dependent manner. Most of these agents are frequently used in cancer therapy. Induction of klf6 expression in the absence of functional p53 directly correlates with cell death triggered by these compounds, whereas it is down-regulated in p53+/+ cells. Hence, klf6 expression level could represent a valuable marker for the efficiency of cell death upon cancer treatment.

  8. Comet assay for rapid detection of base damage in foods

    International Nuclear Information System (INIS)

    Al-Zubaidi, I. A.; Abdullah, T. S.; Qasim, S. R.

    2012-12-01

    Single cell gel electrophoresis (SCGE) or comet assay technique a sensitive, reliable and rapid method for DNA double and single strand break, alkali- labile site and delayed repair site detection in individual cells. In recent years, this method has been widely used for studies of DNA repair, genetic toxicology, and environmental biomontoring, however, this technique serves as an important tool for detection of DNA damage in living organism and is increasing being used in genetic testing of industrial chemicals, environmental agent's contaminations. This research paper helps to evaluate the oxidant agent's effects of exposure to organic pollutants by using comet assay techniques. This study used five samples of each food sample (Meat, Chicken, Rice, Fruits, Vegetables and Tea) to evaluate the genotoxic effects of exposure, to environmental agent's pollutants. The experimental data suggest that the DNA damage parameters ( Tail length, Tail width 1 ) were found higher value in exposed population when compared with the ratio of the length to width that cells exhibiting no migration having a ratio of 1. The percentage and distribution of cells in exposed population of cells also increases with the increase in values. This study demonstrates that, using sensitive techniques, it is possible to detect environmental agent's risks at an early stage. (Author)

  9. Hypoxic conditioning as a new therapeutic modality

    Directory of Open Access Journals (Sweden)

    Samuel eVerges

    2015-06-01

    Full Text Available Preconditioning refers to a procedure by which a single noxious stimulus below the threshold of damage is applied to the tissue in order to increase resistance to the same or even different noxious stimuli given above the threshold of damage. Hypoxic preconditioning relies on complex and active defenses that organisms have developed to counter the adverse consequences of oxygen deprivation. The protection it confers against ischemic attack for instance as well as the underlying biological mechanisms have been extensively investigated in animal models. Based on these data, hypoxic conditioning (consisting in recurrent exposure to hypoxia has been suggested a potential non-pharmacological therapeutic intervention to enhance some physiological functions in individuals in whom acute or chronic pathological events are anticipated or existing. In addition to healthy subjects, some benefits have been reported in patients with cardiovascular and pulmonary diseases as well as in overweight and obese individuals. Hypoxic conditioning consisting in sessions of intermittent exposure to moderate hypoxia repeated over several weeks may induce hematological, vascular, metabolic and neurological effects. This review addresses the existing evidence regarding the use of hypoxic conditioning as a potential therapeutic modality and emphasizes on many remaining issues to clarify and future researches to be performed in the field.

  10. Damage-induced ectopic recombination in the yeast Saccharomyces cerevisiae.

    Science.gov (United States)

    Kupiec, M; Steinlauf, R

    1997-06-09

    Mitotic recombination in the yeast Saccharomyces cerevisiae is induced when cells are irradiated with UV or X-rays, reflecting the efficient repair of damage by recombinational repair mechanisms. We have used multiply marked haploid strains that allow the simultaneous detection of several types of ectopic recombination events. We show that inter-chromosomal ectopic conversion of lys2 heteroalleles and, to a lesser extent, direct repeat recombination (DRR) between non-tandem repeats, are increased by DNA-damaging agents; in contrast, ectopic recombination of the naturally occurring Ty element is not induced. We have tested several hypotheses that could explain the preferential lack of induction of Ty recombination by DNA-damaging agents. We have found that the lack of induction cannot be explained by a cell cycle control or by an effect of the mating-type genes. We also found no role for the flanking long terminal repeats (LTRs) of the Ty in preventing the induction. Ectopic conversion, DRR, and forward mutation of artificial repeats show different kinetics of induction at various positions of the cell cycle, reflecting different mechanisms of recombination. We discuss the mechanistic and evolutionary aspects of these results.

  11. Effects of adenosine monophosphate on induction of therapeutic hypothermia and neuronal damage after cardiopulmonary resuscitation in rats.

    Science.gov (United States)

    Knapp, Jürgen; Schneider, Andreas; Nees, Corinna; Bruckner, Thomas; Böttiger, Bernd W; Popp, Erik

    2014-09-01

    Animal studies and pathophysiological considerations suggest that therapeutic hypothermia after cardiopulmonary resuscitation is the more effective the earlier it is induced. Therefore this study is sought to examine whether pharmacological facilitated hypothermia by administration of 5'-adenosine monophosphate (AMP) is neuroprotective in a rat model of cardiac arrest (CA) and resuscitation. Sixty-one rats were subjected to CA. After 6 min of ventricular fibrillation advanced cardiac life support was started. After successful return of spontaneous circulation (ROSC, n=40), animals were randomized either to placebo group (n=14) or AMP group (800 mg/kg body weight, n=14). Animals were kept at an ambient temperature of 18°C for 12 h after ROSC and core body temperature was measured using a telemetry temperature probe. Neuronal damage was analyzed by counting Nissl-positive (i.e. viable) neurons and TUNEL-positive (i.e. apoptotic) cells in coronal brain sections 7 days after ROSC. Functional status evaluated on days 1, 3 and 7 after ROSC by a tape removal test. Time until core body temperature dropped to <34.0°C was 31 min [28; 45] in AMP-treated animals and 125 min [90; 180] in the control group (p=0.003). Survival until 7 days after ROSC was comparable in both groups. Also number of Nissl-positive cells (AMP: 1 [1; 7] vs. placebo: 2 [1; 3] per 100 pixel; p=0.66) and TUNEL-positive cells (AMP: 56 [44; 72] vs. placebo: 53 [41; 67] per 100 pixel; p=0.70) did not differ. Neither did AMP affect functional neurological outcome up to 7 days after ROSC. Mean arterial pressure 20 min after ROSC was 49 [45; 55] mmHg in the AMP group in comparison to 91 [83; 95] mmHg in the control group (p<0.001). Although application of AMP reduced the time to reach a core body temperature of <34°C neither survival was improved nor neuronal damage attenuated. Reason for this is probably induction of marked hypotension as an adverse reaction to AMP treatment. Copyright © 2014 Elsevier

  12. Sensitization of melanoma cells to alkylating agent-induced DNA damage and cell death via orchestrating oxidative stress and IKKβ inhibition.

    Science.gov (United States)

    Tse, Anfernee Kai-Wing; Chen, Ying-Jie; Fu, Xiu-Qiong; Su, Tao; Li, Ting; Guo, Hui; Zhu, Pei-Li; Kwan, Hiu-Yee; Cheng, Brian Chi-Yan; Cao, Hui-Hui; Lee, Sally Kin-Wah; Fong, Wang-Fun; Yu, Zhi-Ling

    2017-04-01

    Nitrosourea represents one of the most active classes of chemotherapeutic alkylating agents for metastatic melanoma. Treatment with nitrosoureas caused severe systemic side effects which hamper its clinical use. Here, we provide pharmacological evidence that reactive oxygen species (ROS) induction and IKKβ inhibition cooperatively enhance nitrosourea-induced cytotoxicity in melanoma cells. We identified SC-514 as a ROS-inducing IKKβ inhibitor which enhanced the function of nitrosoureas. Elevated ROS level results in increased DNA crosslink efficiency triggered by nitrosoureas and IKKβ inhibition enhances DNA damage signals and sensitizes nitrosourea-induced cell death. Using xenograft mouse model, we confirm that ROS-inducing IKKβ inhibitor cooperates with nitrosourea to reduce tumor size and malignancy in vivo. Taken together, our results illustrate a new direction in nitrosourea treatment, and reveal that the combination of ROS-inducing IKKβ inhibitors with nitrosoureas can be potentially exploited for melanoma therapy. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

  13. Speciation in Metal Toxicity and Metal-Based Therapeutics

    Directory of Open Access Journals (Sweden)

    Douglas M. Templeton

    2015-04-01

    Full Text Available Metallic elements, ions and compounds produce varying degrees of toxicity in organisms with which they come into contact. Metal speciation is critical to understanding these adverse effects; the adjectives “heavy” and “toxic” are not helpful in describing the biological properties of individual elements, but detailed chemical structures are. As a broad generalization, the metallic form of an element is inert, and the ionic salts are the species that show more significant bioavailability. Yet the salts and other chelates of a metal ion can give rise to quite different toxicities, as exemplified by a range of carcinogenic potential for various nickel species. Another important distinction comes when a metallic element is organified, increasing its lipophilicity and hence its ability to penetrate the blood brain barrier, as is seen, for example, with organic mercury and tin species. Some metallic elements, such as gold and platinum, are themselves useful therapeutic agents in some forms, while other species of the same element can be toxic, thus focusing attention on species interconversions in evaluating metal-based drugs. The therapeutic use of metal-chelating agents introduces new species of the target metal in vivo, and this can affect not only its desired detoxification, but also introduce a potential for further mechanisms of toxicity. Examples of therapeutic iron chelator species are discussed in this context, as well as the more recent aspects of development of chelation therapy for uranium exposure.

  14. In vitro efficiency and mechanistic role of indocyanine green as photodynamic therapy agent for human melanoma

    Energy Technology Data Exchange (ETDEWEB)

    Mamoon, A.M.; Miller, L.; Gamal-Eldeen, A. M.; Ruppel, M. E.; Smith, R. J.; Tsang, T.; Miller, L. M.

    2009-05-02

    Photodynamic therapy (PDT) is a promising treatment for superficial cancer. However, poor therapeutic results have been reported for melanoma, due to the high melanin content. Indocyanine green (ICG) has near infrared absorption (700-800 nm) and melanins do not absorb strongly in this area. This study explores the efficiency of ICG as a PDT agent for human melanoma, and its mechanistic role in the cell death pathway. Human skin melanoma cells (Sk-Mel-28) were incubated with ICG and exposed to a low power Ti:Sapphire laser. Synchrotron-assisted Fourier transform infrared microspectroscopy and hierarchical cluster analysis were used to assess the cell damage and changes in lipid, protein, and nucleic acids. The cell death pathway was determined by analysis of cell viability and apoptosis and necrosis markers. In the cell death pathway, {sup 1}O{sub 2} generation evoked rapid multiple consequences that trigger apoptosis after laser exposure for only 15min including the release of cytochrome c, the activation of total caspases, caspase-3, and caspase-9, the inhibition of NF-{Kappa}B P65, and the enhancement of DNA fragmentation, and histone acetylation. ICG/PDT can efficiently and rapidly induce apoptosis in human melanoma cells and it can be considered as a new therapeutic approach for topical treatment of melanoma.

  15. Near Infrared Fluorescence Imaging in Nano-Therapeutics and Photo-Thermal Evaluation

    Science.gov (United States)

    Vats, Mukti; Mishra, Sumit Kumar; Baghini, Mahdieh Shojaei; Chauhan, Deepak S.; Srivastava, Rohit; De, Abhijit

    2017-01-01

    The unresolved and paramount challenge in bio-imaging and targeted therapy is to clearly define and demarcate the physical margins of tumor tissue. The ability to outline the healthy vital tissues to be carefully navigated with transection while an intraoperative surgery procedure is performed sets up a necessary and under-researched goal. To achieve the aforementioned objectives, there is a need to optimize design considerations in order to not only obtain an effective imaging agent but to also achieve attributes like favorable water solubility, biocompatibility, high molecular brightness, and a tissue specific targeting approach. The emergence of near infra-red fluorescence (NIRF) light for tissue scale imaging owes to the provision of highly specific images of the target organ. The special characteristics of near infra-red window such as minimal auto-fluorescence, low light scattering, and absorption of biomolecules in tissue converge to form an attractive modality for cancer imaging. Imparting molecular fluorescence as an exogenous contrast agent is the most beneficial attribute of NIRF light as a clinical imaging technology. Additionally, many such agents also display therapeutic potentials as photo-thermal agents, thus meeting the dual purpose of imaging and therapy. Here, we primarily discuss molecular imaging and therapeutic potentials of two such classes of materials, i.e., inorganic NIR dyes and metallic gold nanoparticle based materials. PMID:28452928

  16. Focal neuronal gigantism: a rare complication of therapeutic radiation.

    Science.gov (United States)

    Gaughen, J R; Bourne, T D; Aregawi, D; Shah, L M; Schiff, D

    2009-11-01

    Radiation therapy, a mainstay in the treatment of many brain tumors, results in a variety of well-documented acute and chronic complications. Isolated cortical damage following irradiation represents an extremely rare delayed therapeutic complication, described only twice in the medical literature. We report this rare delayed complication in a patient following treatment of a right frontal anaplastic oligodendroglioma.

  17. Potential of radiosensitizing agents in cancer chemo-radiotherapy

    Directory of Open Access Journals (Sweden)

    Girdhani S

    2005-01-01

    Full Text Available Potential of herbs and other plant-based formulations have been increasingly recognized in prevention and treatment of human diseases including cancer. There exist enormous prospect for screening and evaluation of herbal/plant products for developing effective radiosensitization and radioprotection relevant to nuclear research program. Investigations in our laboratory have focused on the mechanism of activity of variety of anticancer and antioxidant agents, namely, Eugenol, (EU, Ellagic acid (EA, Triphala (TPL, Tocopherol Succinate (TOS and Arachidonic acid on normal and cancer cells with view to design effective protocols in practical radioprotection and cancer radiotherapy. This paper is mainly focused on studies on cytotoxic effects on cancer cell lines. Results have shown that these agents produced radiosensitizing action involving oxidative damage, membrane alteration and damage to nucleic acid in various human cell lines. Studies were performed employing fluorescence probes and electron spin resonance methods and gel electrophoresis protocols. It has been found that cytotoxic effect was induced by initiating membrane oxidative damage and by triggering intracellular generation of reactive oxygen species (ROS by gamma radiation in combination with phytochemicals like TPL, EA and TOS in tumor cell line Ehrlich Ascites (EAC, Human cervical (HeLa and breast (MCF-7 cells. Membrane damage and ROS generation was measured by DPH and DCF-FDA fluorescent probes respectively after exposure to low to moderate doses of gamma radiation. This talk will present the cytotoxic effects of phytochemicals in combination with ionizing radiation. It is emphasized that modulation of membrane peroxidative damage and intra cellular ROS may help achieve efficient killing of cancer cells which may provide a new approach to developing effective treatment of cancer.

  18. Oncogenic RAS enables DNA damage- and p53-dependent differentiation of acute myeloid leukemia cells in response to chemotherapy.

    Directory of Open Access Journals (Sweden)

    Mona Meyer

    Full Text Available Acute myeloid leukemia (AML is a clonal disease originating from myeloid progenitor cells with a heterogeneous genetic background. High-dose cytarabine is used as the standard consolidation chemotherapy. Oncogenic RAS mutations are frequently observed in AML, and are associated with beneficial response to cytarabine. Why AML-patients with oncogenic RAS benefit most from high-dose cytarabine post-remission therapy is not well understood. Here we used bone marrow cells expressing a conditional MLL-ENL-ER oncogene to investigate the interaction of oncogenic RAS and chemotherapeutic agents. We show that oncogenic RAS synergizes with cytotoxic agents such as cytarabine in activation of DNA damage checkpoints, resulting in a p53-dependent genetic program that reduces clonogenicity and increases myeloid differentiation. Our data can explain the beneficial effects observed for AML patients with oncogenic RAS treated with higher dosages of cytarabine and suggest that induction of p53-dependent differentiation, e.g. by interfering with Mdm2-mediated degradation, may be a rational approach to increase cure rate in response to chemotherapy. The data also support the notion that the therapeutic success of cytotoxic drugs may depend on their ability to promote the differentiation of tumor-initiating cells.

  19. Synthetic Curcumin Analogs as Inhibitors of β -Amyloid Peptide Aggregation: Potential Therapeutic and Diagnostic Agents for Alzheimer's Disease.

    Science.gov (United States)

    Bukhari, Syed Nasir Abbas; Jantan, Ibrahim

    2015-01-01

    There is a crucial need to develop new effective drugs for Alzheimer's disease (AD) as the currently available AD treatments provide only momentary and incomplete symptomatic relief. Amongst natural products, curcumin, a major constituent of turmeric, has been intensively investigated for its neuroprotective effect against β-amyloid (Aβ)-induced toxicity in cultured neuronal cells. The ability of curcumin to attach to Aβ peptide and prevent its accumulation is attributed to its three structural characteristics such as the presence of two aromatic end groups and their co-planarity, the length and rigidity of the linker region and the substitution conformation of these aromatics. However, curcumin failed to reach adequate brain levels after oral absorption in AD clinical trials due to its low water solubility and poor oral bioavailability. A number of new curcumin analogs that mimic the active site of the compound along with analogs that mimic the curcumin anti-amyloid effect combined with anticholinesterase effect have been developed to enhance the bioavailability, pharmacokinetics, water solubility, stability at physiological conditions and delivery of curcumin. In this article, we have summarized all reported synthetic analogs of curcumin showing effects on β-amyloid and discussed their potential as therapeutic and diagnostic agents for AD.

  20. Cell-based therapeutic strategies for multiple sclerosis

    DEFF Research Database (Denmark)

    Scolding, Neil J; Pasquini, Marcelo; Reingold, Stephen C

    2017-01-01

    and none directly promotes repair. Cell-based therapies, including immunoablation followed by autologous haematopoietic stem cell transplantation, mesenchymal and related stem cell transplantation, pharmacologic manipulation of endogenous stem cells to enhance their reparative capabilities......, and transplantation of oligodendrocyte progenitor cells, have generated substantial interest as novel therapeutic strategies for immune modulation, neuroprotection, or repair of the damaged central nervous system in multiple sclerosis. Each approach has potential advantages but also safety concerns and unresolved...

  1. Neuroprotective role of hydralazine in rat spinal cord injury-attenuation of acrolein-mediated damage.

    Science.gov (United States)

    Park, Jonghyuck; Zheng, Lingxing; Marquis, Andrew; Walls, Michael; Duerstock, Brad; Pond, Amber; Vega-Alvarez, Sasha; Wang, He; Ouyang, Zheng; Shi, Riyi

    2014-04-01

    Acrolein, an α,β-unsaturated aldehyde and a reactive product of lipid peroxidation, has been suggested as a key factor in neural post-traumatic secondary injury in spinal cord injury (SCI), mainly based on in vitro and ex vivo evidence. Here, we demonstrate an increase of acrolein up to 300%; the elevation lasted at least 2 weeks in a rat SCI model. More importantly, hydralazine, a known acrolein scavenger can provide neuroprotection when applied systemically. Besides effectively reducing acrolein, hydralazine treatment also resulted in significant amelioration of tissue damage, motor deficits, and neuropathic pain. This effect was further supported by demonstrating the ability of hydralazine to reach spinal cord tissue at a therapeutic level following intraperitoneal application. This suggests that hydralazine is an effective neuroprotective agent not only in vitro, but in a live animal model of SCI as well. Finally, the role of acrolein in SCI was further validated by the fact that acrolein injection into the spinal cord caused significant SCI-like tissue damage and motor deficits. Taken together, available evidence strongly suggests a critical causal role of acrolein in the pathogenesis of spinal cord trauma. Since acrolein has been linked to a variety of illness and conditions, we believe that acrolein-scavenging measures have the potential to be expanded significantly ensuring a broad impact on human health. © 2013 International Society for Neurochemistry.

  2. Neuroprotective role of hydralazine in rat spinal cord injury-attenuation of acrolein-mediated damage

    Science.gov (United States)

    Park, Jonghyuck; Zheng, Lingxing; Marquis, Andrew; Walls, Michael; Duerstock, Brad; Pond, Amber; Alvarez, Sascha Vega; He, Wang; Ouyang, Zheng; Shi, Riyi

    2014-01-01

    Acrolein, an α,β-unsaturated aldehyde and a reactive product of lipid peroxidation, has been suggested as a key factor in neural post-traumatic secondary injury in SCI, mainly based on in vitro and ex vivo evidence. Here we demonstrate an increase of acrolein up to 300%; the elevation lasted at least two weeks in a rat SCI model. More importantly, hydralazine, a known acrolein scavenger can provide neuroprotection when applied systemically. Besides effectively reducing acrolein, hydralazine treatment also resulted in significant amelioration of tissue damage, motor deficits, and neuropathic pain. This effect was further supported by demonstrating the ability of hydralazine to reach spinal cord tissue at a therapeutic level following intraperitoneal application. This suggests that hydralazine is an effective neuroprotective agent not only in vitro, but in a live animal model of SCI as well. Finally, the role of acrolein in SCI was further validated by the fact that acrolein injection into the spinal cord caused significant SCI-like tissue damage and motor deficits. Taken together, available evidence strongly suggests a critical causal role of acrolein in the pathogenesis of spinal cord trauma. Since acrolein has been linked to a variety of illness and conditions, we believe that acrolein-scavenging measures have the potential to be expanded significantly ensuring a broad impact on human health. PMID:24286176

  3. Development of new therapeutic methods of lung cancer through team approach study

    International Nuclear Information System (INIS)

    Park, Jong Ho; Zo, Jae Ill; Baek, Hee Jong; Jung, Jin Haeng; Lee, Jae Cheol; Ryoo, Baek Yeol; Kim, Mi Sook; Choi, Du Hwan; Park, Sun Young; Lee, Hae Young

    2000-12-01

    The aims of this study were to make the lung cancer clinics in Korea Cancer Center Hospital, and to establish new therapeutic methods of lung cancer for increasing the cure rate and survival rate of patients. Also another purpose of this study was to establish a common treatment method in our hospital. All patients who were operated in Korea Cancer Center Hospital from 1987 due to lung cancer were followed up and evaluated. And we have been studied the effect of postoperative adjuvant therapy in stage I, II, IIIA non-small cell lung cancer patients from 1989 with the phase three study form. Follow-up examinations were scheduled in these patients and interim analysis was made. Also we have been studied the effect of chemo-therapeutic agents in small cell lung cancer patients from 1997 with the phase two study form. We evaluated the results of this study. Some important results of this study were as follows. 1. The new therapeutic method (surgery + MVP chemotherapy) was superior to the standard therapeutic one in stage I Non-small cell lung cancer patients. So, we have to change the standard method of treatment in stage I NSCLC. 2. Also, this new therapeutic method made a good result in stage II NSCLC patients. And this result was reported in The Annals of Thoracic Surgery. 3. However, this new therapeutic method was not superior to the standard treatment method (surgery only) in stage IIIA NSCLC patients. So, we must develop new chemo-therapeutic agents in the future for advanced NSCLC patients. 4. In the results of the randomized phase II studies about small cell lung cancer, there was no difference in survival between Etoposide + Carboplatin + Ifosfamide + Cisplatin group and Etoposide + Carboplatin + Ifosfamide + Cisplatin + Tamoxifen group in both the limited and extended types of small cell lung cancer patients

  4. Damage to haemopoiesis, therapeutic strategies and repair mechanisms

    International Nuclear Information System (INIS)

    Wangenheim, K.H. von; Peterson, H.P.; Feinendegen, L.E.

    1993-01-01

    Investigations were carried out into the question as to whether stem cells surviving irradiation remain intact, which is suggested by radiobiological experience to date, or have suffered permanent lesions. The development of a test system gauging the quality of stem cells and their progeny on the basis of their proliferation ability led to the conclusion that radiation caused long-term injuries that permanently compromised the entire haemopoietic system. Observations of the regeneration of normal and irradiated bone marrow under homogeneous conditions in animal donors subjected to high-dose radiation as well as determinations of spleen colony size, proliferation factor and number of stem cells pointed to the fact that the vast majority of stem cells were permanently damaged. It could be shown that unspecific genetic lesions remained unchanged in surviving stem cells and were passed on to their progeny. Refinements to the original proliferation test and the in vitro determination of the proliferation ability of stem cells and various blood cell lines permitted to differentiate between several causative factors. Studies on ways to diminish stem cell injuries either by influencing humoral proliferation stimuli during the regenerative phase or by the use of radiation protection substances are already in progress. In addition to the primary studies, tests were performed to examine the effects of low dose irradiation, vitamin E deficiency and a static magnetic field. (orig./MG) [de

  5. Radiation damage in biomolecular systems

    CERN Document Server

    Fuss, Martina Christina

    2012-01-01

    Since the discovery of X-rays and radioactivity, ionizing radiations have been widely applied in medicine both for diagnostic and therapeutic purposes. The risks associated with radiation exposure and handling led to the parallel development of the field of radiation protection. Pioneering experiments done by Sanche and co-workers in 2000 showed that low-energy secondary electrons, which are abundantly generated along radiation tracks, are primarily responsible for radiation damage through successive interactions with the molecular constituents of the medium. Apart from ionizing processes, which are usually related to radiation damage, below the ionization level low-energy electrons can induce molecular fragmentation via dissociative processes such as internal excitation and electron attachment. This prompted collaborative projects between different research groups from European countries together with other specialists from Canada,  the USA and Australia. This book summarizes the advances achieved by these...

  6. An update on anti-TNF agents in ulcerative colitis

    NARCIS (Netherlands)

    Samaan, Mark A.; Bagi, Preet; Vande Casteele, Niels; D'Haens, Geert R.; Levesque, Barrett G.

    2014-01-01

    Anti-tumor necrosis factor-α agents are key therapeutic options for the treatment of ulcerative colitis. Their efficacy and safety have been shown in large randomized controlled trials. The key evidence gained from these trials of infliximab, adalimumab, and golimumab is reviewed along with their

  7. Incidence and impact of damage to South Carolina's timber, 1979

    Science.gov (United States)

    Robert L. Anderson; Joe P. McClure; William H. Hoffard; Noel D. Cost

    1981-01-01

    This bulletin reports survey data on agents damaging trees in South Carolina’s forests. Data were collected in 1977 and 1978 by the Renewable Resources Evaluation Work Unit of the Southeastern Forest Experiment Station.

  8. The complexity of DNA damage: relevance to biological consequences

    International Nuclear Information System (INIS)

    Ward, J.F.

    1994-01-01

    Ionizing radiation causes both singly and multiply damaged sites in DNA when the range of radical migration is limited by the presence of hydroxyl radical scavengers (e.g. within cells). Multiply damaged sites are considered to be more biologically relevant because of the challenges they present to cellular repair mechanisms. These sites occur in the form of DNA double-strand breaks (dsb) but also as other multiple damages that can be converted to dsb during attempted repair. The presence of a dsb can lead to loss of base sequence information and/or can permit the two ends of a break to separate and rejoin with the wrong partner. (Multiply damaged sites may also be the biologically relevant type of damage caused by other agents, such as UVA, B and/or C light, and some antitumour antibiotics). The quantitative data available from radiation studies of DNA are shown to support the proposed mechanisms for the production of complex damage in cellular DNA, i.e. via scavengable and non-scavengable mechanisms. The yields of complex damages can in turn be used to support the conclusion that cellular mutations are a consequence of the presence of these damages within a gene. (Author)

  9. An anthocyanin-rich strawberry extract protects against oxidative stress damage and improves mitochondrial functionality in human dermal fibroblasts exposed to an oxidizing agent.

    Science.gov (United States)

    Giampieri, Francesca; Alvarez-Suarez, José M; Mazzoni, Luca; Forbes-Hernandez, Tamara Y; Gasparrini, Massimiliano; Gonzàlez-Paramàs, Ana M; Santos-Buelga, Celestino; Quiles, Josè L; Bompadre, Stefano; Mezzetti, Bruno; Battino, Maurizio

    2014-08-01

    This study investigates the protective effect of the Sveva strawberry polyphenol-rich extract on human dermal fibroblasts against AAPH-induced oxidative stress. The HPLC-DAD/ESI-MS analysis was used for evaluating the phenolic composition of the fruits. Sveva strawberry presented a high anthocyanin content (639.79 mg per kg fresh fruit), representing ∼86.08% of the total phenolic content, with Pg-3-glc as the most abundant representative (611.18 mg per kg fresh fruit). Only one ellagitannin (agrimoniin) was identified, while two quercetins, three kaempherol derivates, and three ellagic acid derivatives were detected and quantified. Strawberry pre-treatment (0.5 mg ml(-1)) markedly increased human dermal fibroblast viability, with a significant reduction of apoptotic and dead cells, and suppressed AAPH-induced ROS generation, after only 30 minutes of incubation with the oxidizing agent, and lipid peroxidation, against a range of AAPH concentrations tested. Notably, the strawberry extract also improved the mitochondrial functionality: the basal respiratory performance after treatment was ∼1.59-fold higher compared to control cells, while pre-treatment with strawberry extract before oxidative damage increased ∼2.70-fold compared to stressed cells. Our results confirm that the strawberry possesses antioxidant properties, and may be useful for the prevention of free radical-induced skin damage.

  10. Clinical analysis of 503 cases of hyperthyroidism related hepatic damage

    International Nuclear Information System (INIS)

    Zhang Xiaoxia

    2004-01-01

    The clinical characteristics and the therapeutic method of 503 hyperthyroidism related hepatic damage in the paper was discussed. The incidence of the disease of hyperthyroidism related hepatic damage was 39.7%, the rate increases with the increase in age of the patients and the increase of the course of hyperthy-roidism (P 3 and FT 4 . The state of the illness may be get better with the treatment, and ALT and AST were all resumed; The hyperthyroidism was easy to lead to hepatic damage. Treatment was given priority to controlling of hyperthyroidism and put the protection of liver to the second place: the degree of hepatic damage was closely related to age, the course of disease and the state of illness. A timely diagnoses and proper therapy may be lead to desirable result. (author)

  11. The therapeutic journey of benzimidazoles: a review.

    Science.gov (United States)

    Bansal, Yogita; Silakari, Om

    2012-11-01

    Presence of benzimidazole nucleus in numerous categories of therapeutic agents such as antimicrobials, antivirals, antiparasites, anticancer, anti-inflammatory, antioxidants, proton pump inhibitors, antihypertensives, anticoagulants, immunomodulators, hormone modulators, CNS stimulants as well as depressants, lipid level modulators, antidiabetics, etc. has made it an indispensable anchor for development of new therapeutic agents. Varied substitutents around the benzimidazole nucleus have provided a wide spectrum of biological activities. Importance of this nucleus in some activities like, Angiotensin I (AT(1)) receptor antagonism and proton-pump inhibition is reviewed separately in literature. Even some very short reviews on biological importance of this nucleus are also known in literature. However, owing to fast development of new drugs possessing benzimidazole nucleus many research reports are generated in short span of time. So, there is a need to couple the latest information with the earlier information to understand the current status of benzimidazole nucleus in medicinal chemistry research. In the present review, various derivatives of benzimidazole with different pharmacological activities are described on the basis of substitution pattern around the nucleus with an aim to help medicinal chemists for developing an SAR on benzimidazole derived compounds for each activity. This discussion will further help in the development of novel benzimidazole compounds. Copyright © 2012 Elsevier Ltd. All rights reserved.

  12. Trends in GPCR drug discovery: new agents, targets and indications

    DEFF Research Database (Denmark)

    Hauser, Alexander Sebastian; Gloriam, David E.; Attwood, Misty M.

    2017-01-01

    current trends across molecule types, drug targets and therapeutic indications, including showing that 475 drugs (~34% of all drugs approved by the US Food and Drug Administration (FDA)) act at 108 unique GPCRs. Approximately 321 agents are currently in clinical trials, of which ~20% target 66 potentially...... are also highly represented. The 224 (56%) non-olfactory GPCRs that have not yet been explored in clinical trials have broad untapped therapeutic potential, particularly in genetic and immune system disorders. Finally, we provide an interactive online resource to analyse and infer trends in GPCR drug......G protein-coupled receptors (GPCRs) are the most intensively studied drug targets, mostly due to their substantial involvement in human pathophysiology and their pharmacological tractability. Here, we report an up-to-date analysis of all GPCR drugs and agents in clinical trials, which reveals...

  13. Therapeutic applications of histone deacetylase inhibitors in sarcoma.

    Science.gov (United States)

    Tang, Fan; Choy, Edwin; Tu, Chongqi; Hornicek, Francis; Duan, Zhenfeng

    2017-09-01

    Sarcomas are a rare group of malignant tumors originating from mesenchymal stem cells. Surgery, radiation and chemotherapy are currently the only standard treatments for sarcoma. However, their response rates to chemotherapy are quite low. Toxic side effects and multi-drug chemoresistance make treatment even more challenging. Therefore, better drugs to treat sarcomas are needed. Histone deacetylase inhibitors (HDAC inhibitors, HDACi, HDIs) are epigenetic modifying agents that can inhibit sarcoma growth in vitro and in vivo through a variety of pathways, including inducing tumor cell apoptosis, causing cell cycle arrest, impairing tumor invasion and preventing metastasis. Importantly, preclinical studies have revealed that HDIs can not only sensitize sarcomas to chemotherapy and radiotherapy, but also increase treatment responses when combined with other chemotherapeutic drugs. Several phase I and II clinical trials have been conducted to assess the efficacy of HDIs either as monotherapy or in combination with standard chemotherapeutic agents or targeted therapeutic drugs for sarcomas. Combination regimen for sarcomas appear to be more promising than monotherapy when using HDIs. This review summarizes our current understanding and therapeutic applications of HDIs in sarcomas. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Peroxisome Proliferator-Activated Receptor Ligands and Their Role in Chronic Myeloid Leukemia: Therapeutic Strategies.

    Science.gov (United States)

    Yousefi, Bahman; Samadi, Nasser; Baradaran, Behzad; Shafiei-Irannejad, Vahid; Zarghami, Nosratollah

    2016-07-01

    Imatinib therapy remains the gold standard for treatment of chronic myeloid leukemia; however, the acquired resistance to this therapeutic agent in patients has urged the scientists to devise modalities for overcoming this chemoresistance. For this purpose, initially therapeutic agents with higher tyrosine kinase activity were introduced, which had the potential for inhibiting even mutant forms of Bcr-Abl. Furthermore, coupling imatinib with peroxisome proliferator-activated receptor ligands also showed beneficial effects in chronic myeloid leukemia cell proliferation. These combination protocols inhibited cell growth and induced apoptosis as well as differentiation in chronic myeloid leukemia cell lines. In addition, peroxisome proliferator-activated receptors ligands increased imatinib uptake by upregulating the expression of human organic cation transporter 1. Taken together, peroxisome proliferator-activated receptors ligands are currently being considered as novel promising therapeutic candidates for chronic myeloid leukemia treatment, because they can synergistically enhance the efficacy of imatinib. In this article, we reviewed the potential of peroxisome proliferator-activated receptors ligands for use in chronic myeloid leukemia treatment. The mechanism of action of these therapeutics modalities are also presented in detail. © 2016 John Wiley & Sons A/S.

  15. Pathogenesis of Graves' disease and therapeutic implications

    International Nuclear Information System (INIS)

    Seif, F.J.

    1997-01-01

    Graves' disease presents itself clinically mainly as hyperthyroidism and infiltrative ophthalmopathy and to a minimal extent also as dermopathy and acropachy. Autoimmune processes are the basic pathogenesis. Stimulating antibodies against the TSH receptor cause hyperthyroidism. Autoantibodies and autoreactive T lymphocytes against primarily thyroidal antigens cross-react with similar antigens of the eye muscles and orbital connective tissue, thus spreading the disease from the thyroid to the eyes. The therapeutic goal comprises not only the treatment of hyperthyroidism, but also the induction of a steady immuntolerance in order to minimize the irreversible damage to the eye. The therapeutic armamentarium is formed by antithyroid drugs, glucocorticoids, retrobulbar radition and thyroid ablation, either by nearly total thyroidectomy or by radioiodine. The different indications for both ablative procedures are discussed. (orig.) [de

  16. Curcumin as a potential therapeutic candidate for Helicobacter pylori associated diseases

    Science.gov (United States)

    Sarkar, Avijit; De, Ronita; Mukhopadhyay, Asish K

    2016-01-01

    Curcumin, a yellow pigment and principal polyphenolic Curcuminoid obtained from the turmeric rhizome Curcuma longa, is commonly used as a food-coloring agent. Studies suggest that curcumin has a wide range of beneficial properties e.g., anti-inflammatory, anti-oxidant, anti-cancer, anti-proliferative, anti-fungal and anti-microbial. These pleiotropic activities prompted several research groups to elucidate the role of curcumin in Helicobacter pylori (H. pylori) infection. This is the first review with this heading where we discussed regarding the role of curcumin as an anti-H. pylori agent along with its potential in other gastrointestinal diseases. Based on several in vitro, early cell culture, animal research and few pre-clinical trials, curcumin projected as a potential therapeutic candidate against H. pylori mediated gastric pathogenesis. This review sheds light on the anti-H. pylori effects of curcumin in different models with meticulous emphasis on its anti-oxidant, anti-inflammatory and anti-carcinogenic effects as well as some critical signaling and effecter molecules. Remarkably, non-toxic molecule curcumin fulfills the characteristics for an ideal chemopreventive agent against H. pylori mediated gastric carcinogenesis but the foremost challenge is to obtain the optimum therapeutic levels of curcumin, due to its low solubility and poor bioavailability. Further, we have discussed about the possibilities for improving its efficacy and bioavailability. Lastly, we concluded with the anticipation that in near future curcumin may be used to develop a therapeutic drug against H. pylori mediated gastric ailments through improved formulation or delivery systems, facilitating its enhanced absorption and cellular uptake. PMID:26973412

  17. Modulator Effect of Turmeric on Oxidative Damage in Whole Body Gamma Irradiated rats

    International Nuclear Information System (INIS)

    Amin, H.H.; Abdou, M.I.

    2012-01-01

    Because of its penetrating power and its ability to travel great distances, gamma rays are considered the primary hazard to the population during most radiological emergencies. So, there is a need to develop medical countermeasures to protect the first responders and remediation workers from biomedical effect of ionizing radiation. Turmeric has been reported to have many beneficial health effects, including a strong anti-oxidant effect, anti-inflammatory and anti-microbial properties. In the present study, turmeric was investigated as a therapeutic agent against hazards induced by ionizing radiation on kidney, liver, urinary and serum calcium levels and blood counts. A daily dose of 0.5 g/kg body weight was used in whole body gamma irradiated female rats with 3 Gy. Radiation effects were followed up for four weeks post irradiation. The results revealed that the administration of turmeric post-irradiation resulted in a significant inhibition in the frequency of radiation induced oxidative damage. It could be concluded that definite turmeric dose exerts a vital modulator role against gamma irradiation hazard

  18. Inflammation, oxidative DNA damage, and carcinogenesis

    International Nuclear Information System (INIS)

    Lewis, J.G.; Adams, D.O.

    1987-01-01

    Inflammation has long been associated with carcinogenesis, especially in the promotion phase. The mechanism of action of the potent inflammatory agent and skin promoter 12-tetradecanoyl phorbol-13-acetate (TPA) is unknown. It is though that TPA selectively enhances the growth of initiated cells, and during this process, initiated cells progress to the preneoplastic state and eventually to the malignant phenotype. The authors and others have proposed that TPA may work, in part, by inciting inflammation and stimulating inflammatory cells to release powerful oxidants which then induce DNA damage in epidermal cells. Macrophages cocultured with target cells and TPA induce oxidized thymine bases in the target cells. This process is inhibited by both catalase and inhibitors of lipoxygenases, suggesting the involvement of both H 2 O 2 and oxidized lipid products. In vivo studies demonstrated that SENCAR mice, which are sensitive to promotion by TPA, have a more intense inflammatory reaction in skin that C57LB/6 mice, which are resistant to promotion by TPA. In addition, macrophages from SENCAR mice release more H 2 O 2 and metabolites of AA, and induce more oxidative DNA damage in cocultured cells than macrophages from C57LB/6 mice. These data support the hypothesis that inflammation and the release of genotoxic oxidants may be one mechanism whereby initiated cells receive further genetic insults. They also further complicate risk assessment by suggesting that some environmental agents may work indirectly by subverting host systems to induce damage rather than maintaining homeostasis

  19. The cytoskeleton as a novel therapeutic target for old neurodegenerative disorders.

    Science.gov (United States)

    Eira, Jessica; Silva, Catarina Santos; Sousa, Mónica Mendes; Liz, Márcia Almeida

    2016-06-01

    Cytoskeleton defects, including alterations in microtubule stability, in axonal transport as well as in actin dynamics, have been characterized in several unrelated neurodegenerative conditions. These observations suggest that defects of cytoskeleton organization may be a common feature contributing to neurodegeneration. In line with this hypothesis, drugs targeting the cytoskeleton are currently being tested in animal models and in human clinical trials, showing promising effects. Drugs that modulate microtubule stability, inhibitors of posttranslational modifications of cytoskeletal components, specifically compounds affecting the levels of tubulin acetylation, and compounds targeting signaling molecules which regulate cytoskeleton dynamics, constitute the mostly addressed therapeutic interventions aiming at preventing cytoskeleton damage in neurodegenerative disorders. In this review, we will discuss in a critical perspective the current knowledge on cytoskeleton damage pathways as well as therapeutic strategies designed to revert cytoskeleton-related defects mainly focusing on the following neurodegenerative disorders: Alzheimer's Disease, Parkinson's Disease, Huntington's Disease, Amyotrophic Lateral Sclerosis and Charcot-Marie-Tooth Disease. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. Technological advancements for the detection of and protection against biological and chemical warfare agents.

    Science.gov (United States)

    Eubanks, Lisa M; Dickerson, Tobin J; Janda, Kim D

    2007-03-01

    There is a growing need for technological advancements to combat agents of chemical and biological warfare, particularly in the context of the deliberate use of a chemical and/or biological warfare agent by a terrorist organization. In this tutorial review, we describe methods that have been developed both for the specific detection of biological and chemical warfare agents in a field setting, as well as potential therapeutic approaches for treating exposure to these toxic species. In particular, nerve agents are described as a typical chemical warfare agent, and the two potent biothreat agents, anthrax and botulinum neurotoxin, are used as illustrative examples of potent weapons for which countermeasures are urgently needed.

  1. Acinetobacter pneumonia: Is the outcome different from the pneumonias caused by other agents

    Directory of Open Access Journals (Sweden)

    Edis Ebru

    2010-01-01

    Full Text Available Background : The principal aim of the present study was to determine whether Acinetobacter spp. pneumonia differs from hospital-acquired pneumonias (HAPs caused by other agents with respect to therapeutic success and survival rate. METHODS : This study includes 140 adult patients diagnosed with HAPs caused by identified etiologic agents between March 2005 and February 2006. These patients were divided into two groups according to the agent responsible for their infection (Acinetobacter spp. [n = 63] or non-Acinetobacter spp. [n = 77]. The groups were compared in terms of risk factors, therapeutic success and six-week survival rates. Results : Previous antibiotic use and the risk of aspiration were independent factors responsible for the development of Acinetobacter spp. pneumonia. Hypoalbuminemia, steroid use and the use of a mechanical ventilator were determined to be mortality-associated independent risk factors for Acinetobacter spp. pneumonia. The clinical success rate at the end of therapy was 41.6% and, at the sixth week, the survival rate was 35% among patients in whom Acinetobacter spp. was the causative agent. Conversely, in the control group, these values were 43 and 32%, respectively ( P > 0.05. We found that the use of the appropriate antibiotics for the treatment of Acinetobacter spp. pneumonia was an important factor in survival ( P < 0.001. Conclusion : The outcomes of Acinetobacter spp. pneumonia do not differ from HAPs associated with non-Acinetobacter spp. in terms of therapeutic success and survival rates.

  2. Emerging protein targets for metal-based pharmaceutical agents : An update

    NARCIS (Netherlands)

    de Almeida, Andreia; Oliveira, Bruno L.; Correia, Joao D. G.; Soveral, Graca; Casini, Angela

    2013-01-01

    The peculiar chemical properties of metal-based drugs impart innovative pharmacological profiles to this class of therapeutic and diagnostic agents, most likely in relation to novel molecular mechanisms still poorly understood. However, inorganic drugs have been scarcely considered for medicinal

  3. Future prospects of therapeutic clinical trials in acute myeloid leukemia

    Science.gov (United States)

    Khan, Maliha; Mansoor, Armaghan-e-Rehman; Kadia, Tapan M

    2017-01-01

    Acute myeloid leukemia (AML) is a markedly heterogeneous hematological malignancy that is most commonly seen in elderly adults. The response to current therapies to AML is quite variable, and very few new drugs have been recently approved for use in AML. This review aims to discuss the issues with current trial design for AML therapies, including trial end points, patient enrollment, cost of drug discovery and patient heterogeneity. We also discuss the future directions in AML therapeutics, including intensification of conventional therapy and new drug delivery mechanisms; targeted agents, including epigenetic therapies, cell cycle regulators, hypomethylating agents and chimeric antigen receptor T-cell therapy; and detail of the possible agents that may be incorporated into the treatment of AML in the future. PMID:27771959

  4. Scavenging of peroxynitrite by phycocyanin and phycocyanobilin from Spirulina platensis: protection against oxidative damage to DNA.

    Science.gov (United States)

    Bhat, V B; Madyastha, K M

    2001-07-13

    Peroxynitrite (ONOO(-)) is known to inactivate important cellular targets and also mediate oxidative damage in DNA. The present study has demonstrated that phycocyanin, a biliprotein from spirulina platensis and its chromophore, phycocyanobilin (PCB), efficiently scavenge ONOO(-), a potent physiological inorganic toxin. Scavenging of ONOO(-) by phycocyanin and PCB was established by studying their interaction with ONOO(-) and quantified by using competition kinetics of pyrogallol red bleaching assay. The relative antioxidant ratio and IC(50) value clearly indicate that phycocyanin is a more efficient ONOO(-) scavenger than PCB. The present study has also shown that PCB significantly inhibits the ONOO(-)-mediated single-strand breaks in supercoiled plasmid DNA in a dose-dependent manner with an IC(50) value of 2.9 +/- 0.6 microM. These results suggest that phycocyanin, has the ability to inhibit the ONOO(-)-mediated deleterious biological effects and hence has the potential to be used as a therapeutic agent. Copyright 2001 Academic Press.

  5. Role of the Checkpoint Clamp in DNA Damage Response

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    Mihoko Kai

    2013-01-01

    Full Text Available DNA damage occurs during DNA replication, spontaneous chemical reactions, and assaults by external or metabolism-derived agents. Therefore, all living cells must constantly contend with DNA damage. Cells protect themselves from these genotoxic stresses by activating the DNA damage checkpoint and DNA repair pathways. Coordination of these pathways requires tight regulation in order to prevent genomic instability. The checkpoint clamp complex consists of Rad9, Rad1 and Hus1 proteins, and is often called the 9-1-1 complex. This PCNA (proliferating cell nuclear antigen-like donut-shaped protein complex is a checkpoint sensor protein that is recruited to DNA damage sites during the early stage of the response, and is required for checkpoint activation. As PCNA is required for multiple pathways of DNA metabolism, the checkpoint clamp has also been implicated in direct roles in DNA repair, as well as in coordination of the pathways. Here we discuss roles of the checkpoint clamp in DNA damage response (DDR.

  6. The omega-3 fatty acid, eicosapentaenoic acid (EPA, prevents the damaging effects of tumour necrosis factor (TNF-alpha during murine skeletal muscle cell differentiation

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    Pearson Stephen

    2008-07-01

    Full Text Available Abstract Background Eicosapentaenoic acid (EPA is a ώ-3 polyunsaturated fatty acid with anti-inflammatory and anti-cachetic properties that may have potential benefits with regards to skeletal muscle atrophy conditions where inflammation is present. It is also reported that pathologic levels of the pro-inflammatory cytokine tumour necrosis factor (TNF-α are associated with muscle wasting, exerted through inhibition of myogenic differentiation and enhanced apoptosis. These findings led us to hypothesize that EPA may have a protective effect against skeletal muscle damage induced by the actions of TNF-α. Results The deleterious effects of TNF-α on C2C12 myogenesis were completely inhibited by co-treatment with EPA. Thus, EPA prevented the TNF-mediated loss of MyHC expression and significantly increased myogenic fusion (p p p p p p Conclusion In conclusion, EPA has a protective action against the damaging effects of TNF-α on C2C12 myogenesis. These findings support further investigations of EPA as a potential therapeutic agent during skeletal muscle regeneration following injury.

  7. Mild Epicureanism: notes toward the definition of a therapeutic attitude.

    Science.gov (United States)

    Strenger, Carlo

    2008-01-01

    Psychotherapists generally feel uncomfortable addressing patients' beliefs, particularly religious beliefs, because of the desire to respect client subjectivity and to avoid the abuse of therapeutic authority. This paper's first contention is that at some junctures, investigation of the client's belief structure can be an important catalyst for change, as exemplified by an extended case example. This stance assumes that much of the individual and collective damage rigid belief systems inflict derives from their function as a defense against death awareness, as described by terror management theory. The paper develops the concept of a therapeutic meta-attitude towards belief mild Epicureanism, related to the classical Greek philosopher Epicurus (341-270 BC). Mild Epicureanism means to soften attachments to all belief systems, even therapeutic theories, to lower their potential inhibition of personal growth. The paper presents the argument that mild Epicureanism is consistent with most therapeutic approaches, and allows addressing clients' belief without interfering with their right to make up their own minds.

  8. Heterocyclic N-Oxides – An Emerging Class of Therapeutic Agents

    Science.gov (United States)

    Mfuh, Adelphe M.; Larionov, Oleg V.

    2016-01-01

    Heterocyclic N-oxides have emerged as potent compounds with anticancer, antibacterial, antihypertensive, antiparasitic, anti-HIV, anti-inflammatory, herbicidal, neuroprotective, and procognitive activities. The N-oxide motif has been successfully employed in a number of recent drug development projects. This review surveys the emergence of this scaffold in the mainstream medicinal chemistry with a focus on the discovery of the heterocyclic N-oxide drugs, N-oxide-specific mechanisms of action, drug-receptor interactions and synthetic avenues to these compounds. As the first review on this subject that covers the developments since 1950s to date, it is expected that it will inspire wider implementation of the heterocyclic N-oxide motif in the rational design of new medicinal agents. PMID:26087764

  9. Let the sun shine in: mechanisms and potential for therapeutics in skin photodamage.

    Science.gov (United States)

    Wondrak, Georg T

    2007-05-01

    Photoaging and photocarcinogenesis are the two Janus faces of skin photodamage. Reactivity-based design of prototype agents that antagonize, modulate and reverse the chemistry of skin photodamage holds promise in delivering unprecedented therapeutic benefit. In contrast to structure-based approaches that use selective ligands to target macromolecules, reactivity-based drug discovery uses chemical reagents as therapeutics to target reactive chemical species as key mediators of skin photo-oxidative stress. The following classes of reactivity-based agents for skin photoprotection can be distinguished based on their mechanism of action: direct antagonists of photo-oxidative stress (sunscreens, quenchers of photo-excited states, antioxidants, redox modulators and glycation inhibitors) and skin photo-adaptation inducers (nuclear factor erythroid 2-related factor 2 [Nrf2] activators, heat-shock response inducers and metallothionein inducers).

  10. Self-Assembling Peptide Amphiphiles for Therapeutic Delivery of Proteins, Drugs, and Stem Cells

    Science.gov (United States)

    Lee, Sungsoo Seth

    Biomaterials are used to help regenerate or replace the structure and function of damaged tissues. In order to elicit desired therapeutic responses in vivo, biomaterials are often functionalized with bioactive agents, such as growth factors, small molecule drugs, or even stem cells. Therefore, the strategies used to incorporate these bioactive agents in the microstructures and nanostructures of biomaterials can strongly influence the their therapeutic efficacy. Using self-assembling peptide amphiphiles (PAs), this work has investigated supramolecular nanostructures with improved interaction with three types of therapeutic agents: bone morphogenetic protein 2 (BMP-2) which promotes osteogenic differentiation and bone growth, anti-inflammatory drug naproxen which is used to treat osteo- and rheumatoid arthritis, and neural stem cells that could differentiate into neurons to treat neurodegenerative diseases. For BMP-2 delivery, two specific systems were investigated with affinity for BMP-2: 1) heparin-binding nanofibers that display the natural ligand of the osteogenic protein, and 2) nanofibers that display a synthetic peptide ligand discovered in our laboratory through phage display to directly bind BMP-2. Both systems promoted enhanced osteoblast differentiation of pluripotent C2C12 cells and augmented bone regeneration in two in vivo models, a rat critical-size femur defect model and spinal arthrodesis model. The thesis also describes the use of PA nanofibers to improve the delivery of the anti-inflammatory drug naproxen. To promote a controlled release, naproxen was chemically conjugated to the nanofiber surface via an ester bond that would only be cleaved by esterases, which are enzymes found naturally in the body. In the absence of esterases, the naproxen remained conjugated to the nanofibers and was non-bioactive. On the other hand, in the presence of esterases, naproxen was slowly released and inhibited cyclooxygenase-2 (COX-2) activity, an enzyme responsible

  11. Challenges in the development of magnetic particles for therapeutic applications.

    Science.gov (United States)

    Barry, Stephen E

    2008-09-01

    Certain iron-based particle formulations have useful magnetic properties that, when combined with low toxicity and desirable pharmacokinetics, encourage their development for therapeutic applications. This mini-review begins with background information on magnetic particle use as MRI contrast agents and the influence of material size on pharmacokinetics and tissue penetration. Therapeutic investigations, including (1) the loading of bioactive materials, (2) the use of stationary, high-gradient (HG) magnetic fields to concentrate magnetic particles in tissues or to separate material bound to the particles from the body, and (3) the application of high power alternating magnetic fields (AMF) to generate heat in magnetic particles for hyperthermic therapeutic applications are then surveyed. Attention is directed mainly to cancer treatment, as selective distribution to tumors is well-suited to particulate approaches and has been a focus of most development efforts. While magnetic particles have been explored for several decades, their use in therapeutic products remains minimal; a discussion of future directions and potential ways to better leverage magnetic properties and to integrate their use into therapeutic regimens is discussed.

  12. Loss of Atrx sensitizes cells to DNA damaging agents through p53-mediated death pathways.

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    Damiano Conte

    Full Text Available Prevalent cell death in forebrain- and Sertoli cell-specific Atrx knockout mice suggest that Atrx is important for cell survival. However, conditional ablation in other tissues is not associated with increased death indicating that diverse cell types respond differently to the loss of this chromatin remodeling protein. Here, primary macrophages isolated from Atrx(f/f mice were infected with adenovirus expressing Cre recombinase or β-galactosidase, and assayed for cell survival under different experimental conditions. Macrophages survive without Atrx but undergo rapid apoptosis upon lipopolysaccharide (LPS activation suggesting that chromatin reorganization in response to external stimuli is compromised. Using this system we next tested the effect of different apoptotic stimuli on cell survival. We observed that survival of Atrx-null cells were similar to wild type cells in response to serum withdrawal, anti-Fas antibody, C2 ceramide or dexamethasone treatment but were more sensitive to 5-fluorouracil (5-FU. Cell survival could be rescued by re-introducing Atrx or by removal of p53 demonstrating the cell autonomous nature of the effect and its p53-dependence. Finally, we demonstrate that multiple primary cell types (myoblasts, embryonic fibroblasts and neurospheres were sensitive to 5-FU, cisplatin, and UV light treatment. Together, our results suggest that cells lacking Atrx are more sensitive to DNA damaging agents and that this may result in enhanced death during development when cells are at their proliferative peak. Moreover, it identifies potential treatment options for cancers associated with ATRX mutations, including glioblastoma and pancreatic neuroendocrine tumors.

  13. Genome-Wide Mutational Signature of the Chemotherapeutic Agent Mitomycin C in Caenorhabditis elegans.

    Science.gov (United States)

    Tam, Annie S; Chu, Jeffrey S C; Rose, Ann M

    2015-11-12

    Cancer therapy largely depends on chemotherapeutic agents that generate DNA lesions. However, our understanding of the nature of the resulting lesions as well as the mutational profiles of these chemotherapeutic agents is limited. Among these lesions, DNA interstrand crosslinks are among the more toxic types of DNA damage. Here, we have characterized the mutational spectrum of the commonly used DNA interstrand crosslinking agent mitomycin C (MMC). Using a combination of genetic mapping, whole genome sequencing, and genomic analysis, we have identified and confirmed several genomic lesions linked to MMC-induced DNA damage in Caenorhabditis elegans. Our data indicate that MMC predominantly causes deletions, with a 5'-CpG-3' sequence context prevalent in the deleted regions of DNA. Furthermore, we identified microhomology flanking the deletion junctions, indicative of DNA repair via nonhomologous end joining. Based on these results, we propose a general repair mechanism that is likely to be involved in the biological response to this highly toxic agent. In conclusion, the systematic study we have described provides insight into potential sequence specificity of MMC with DNA. Copyright © 2016 Tam et al.

  14. Genome-Wide Mutational Signature of the Chemotherapeutic Agent Mitomycin C in Caenorhabditis elegans

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    Annie S. Tam

    2016-01-01

    Full Text Available Cancer therapy largely depends on chemotherapeutic agents that generate DNA lesions. However, our understanding of the nature of the resulting lesions as well as the mutational profiles of these chemotherapeutic agents is limited. Among these lesions, DNA interstrand crosslinks are among the more toxic types of DNA damage. Here, we have characterized the mutational spectrum of the commonly used DNA interstrand crosslinking agent mitomycin C (MMC. Using a combination of genetic mapping, whole genome sequencing, and genomic analysis, we have identified and confirmed several genomic lesions linked to MMC-induced DNA damage in Caenorhabditis elegans. Our data indicate that MMC predominantly causes deletions, with a 5′-CpG-3′ sequence context prevalent in the deleted regions of DNA. Furthermore, we identified microhomology flanking the deletion junctions, indicative of DNA repair via nonhomologous end joining. Based on these results, we propose a general repair mechanism that is likely to be involved in the biological response to this highly toxic agent. In conclusion, the systematic study we have described provides insight into potential sequence specificity of MMC with DNA.

  15. Acrolein scavengers, cysteamine and N-benzylhydroxylamine, reduces the mouse liver damage after acetaminophen overdose.

    Science.gov (United States)

    Koyama, Ryo; Mizuta, Ryushin

    2017-01-10

    Our previous study suggested that the highly toxic α,β-unsaturated aldehyde acrolein, a byproduct of oxidative stress, plays a major role in acetaminophen-induced liver injury. In this study, to determine the involvement of acrolein in the liver injury and to identify novel therapeutic options for the liver damage, we examined two putative acrolein scavengers, a thiol compound cysteamine and a hydroxylamine N-benzylhydroxylamine, in cell culture and in mice. Our results showed that cysteamine and N-benzylhydroxylamine effectively prevented the cell toxicity of acrolein in vitro and acetaminophen-induced liver injury in vivo, which suggested that acrolein is involved in the liver damage, and these two drugs can be potential therapeutic options for this condition.

  16. 4β-Hydroxywithanolide E from Physalis peruviana (golden berry inhibits growth of human lung cancer cells through DNA damage, apoptosis and G2/M arrest

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    Guo Zong-Lun

    2010-02-01

    Full Text Available Abstract Background The crude extract of the fruit bearing plant, Physalis peruviana (golden berry, demonstrated anti-hepatoma and anti-inflammatory activities. However, the cellular mechanism involved in this process is still unknown. Methods Herein, we isolated the main pure compound, 4β-Hydroxywithanolide (4βHWE derived from golden berries, and investigated its antiproliferative effect on a human lung cancer cell line (H1299 using survival, cell cycle, and apoptosis analyses. An alkaline comet-nuclear extract (NE assay was used to evaluate the DNA damage due to the drug. Results It was shown that DNA damage was significantly induced by 1, 5, and 10 μg/mL 4βHWE for 2 h in a dose-dependent manner (p p 50 of 4βHWE in H1299 cells for 24 and 48 h were 0.6 and 0.71 μg/mL, respectively, suggesting it could be a potential therapeutic agent against lung cancer. In a flow cytometric analysis, 4βHWE produced cell cycle perturbation in the form of sub-G1 accumulation and slight arrest at the G2/M phase with 1 μg/mL for 12 and 24 h, respectively. Using flow cytometric and annexin V/propidium iodide immunofluorescence double-staining techniques, these phenomena were proven to be apoptosis and complete G2/M arrest for H1299 cells treated with 5 μg/mL for 24 h. Conclusions In this study, we demonstrated that golden berry-derived 4βHWE is a potential DNA-damaging and chemotherapeutic agent against lung cancer.

  17. Autophagy in DNA Damage Response

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    Piotr Czarny

    2015-01-01

    Full Text Available DNA damage response (DDR involves DNA repair, cell cycle regulation and apoptosis, but autophagy is also suggested to play a role in DDR. Autophagy can be activated in response to DNA-damaging agents, but the exact mechanism underlying this activation is not fully understood, although it is suggested that it involves the inhibition of mammalian target of rapamycin complex 1 (mTORC1. mTORC1 represses autophagy via phosphorylation of the ULK1/2–Atg13–FIP200 complex thus preventing maturation of pre-autophagosomal structures. When DNA damage occurs, it is recognized by some proteins or their complexes, such as poly(ADPribose polymerase 1 (PARP-1, Mre11–Rad50–Nbs1 (MRN complex or FOXO3, which activate repressors of mTORC1. SQSTM1/p62 is one of the proteins whose levels are regulated via autophagic degradation. Inhibition of autophagy by knockout of FIP200 results in upregulation of SQSTM1/p62, enhanced DNA damage and less efficient damage repair. Mitophagy, one form of autophagy involved in the selective degradation of mitochondria, may also play role in DDR. It degrades abnormal mitochondria and can either repress or activate apoptosis, but the exact mechanism remains unknown. There is a need to clarify the role of autophagy in DDR, as this process may possess several important biomedical applications, involving also cancer therapy.

  18. Evaluating In Vitro DNA Damage Using Comet Assay.

    Science.gov (United States)

    Lu, Yanxin; Liu, Yang; Yang, Chunzhang

    2017-10-11

    DNA damage is a common phenomenon for each cell during its lifespan, and is defined as an alteration of the chemical structure of genomic DNA. Cancer therapies, such as radio- and chemotherapy, introduce enormous amount of additional DNA damage, leading to cell cycle arrest and apoptosis to limit cancer progression. Quantitative assessment of DNA damage during experimental cancer therapy is a key step to justify the effectiveness of a genotoxic agent. In this study, we focus on a single cell electrophoresis assay, also known as the comet assay, which can quantify single and double-strand DNA breaks in vitro. The comet assay is a DNA damage quantification method that is efficient and easy to perform, and has low time/budget demands and high reproducibility. Here, we highlight the utility of the comet assay for a preclinical study by evaluating the genotoxic effect of olaparib/temozolomide combination therapy to U251 glioma cells.

  19. BET inhibitors in metastatic prostate cancer: therapeutic implications and rational drug combinations.

    Science.gov (United States)

    Markowski, Mark C; De Marzo, Angelo M; Antonarakis, Emmanuel S

    2017-12-01

    The bromodomain and extra-terminal (BET) family of proteins are epigenetic readers of acetylated histones regulating a vast network of protein expression across many different cancers. Therapeutic targeting of BET is an attractive area of clinical development for metastatic castration-resistant prostate cancer (mCRPC), particularly due to its putative effect on c-MYC expression and its interaction with the androgen receptor (AR). Areas covered: We speculate that a combination approach using inhibitors of BET proteins (BETi) with other targeted therapies may be required to improve the therapeutic index of BET inhibition in the management of prostate cancer. Preclinical data has identified several molecular targets that may enhance the effect of BET inhibition in the clinic. This review will summarize the known preclinical data implicating BET as an important therapeutic target in advanced prostate cancer, highlight the ongoing clinical trials targeting this protein family, and speculate on rationale combination strategies using BETi together with other agents in prostate cancer. A literature search using Pubmed was performed for this review. Expert opinion: Use of BETi in the treatment of mCRPC patients may require the addition of a second novel agent.

  20. Psoriatic arthritis: treatment strategies using biologic agents

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    C. Palazzi

    2012-06-01

    Full Text Available The traditional management of psoriatic arthritis (PsA includes NSAIDs, corticosteroids and DMARDs. Advancement in the knowledge of the immunopathogenesis of PsA has been associated with the development of biologic agents which have revolutionized the management of the disease. Among biologics drugs, there are the 4 currently availablee anti-TNFα blocking agents (etanercept, infliximab, adalimumab and golimumab which are more effective than traditional DMARDs on symptoms/signs of inflammation, quality of life, function, and in inhibiting the progression of the structural joint damage. Despite of the high cost, TNF inhibitors are costeffective on both the musculoskeletal and skin manifestations of psoriatic disease.

  1. Preparation, Surface Properties, and Therapeutic Applications of Gold Nanoparticles in Biomedicine.

    Science.gov (United States)

    Panahi, Yunes; Mohammadhosseini, Majid; Nejati-Koshki, Kazem; Abadi, Azam Jafari Najaf; Moafi, Hadi Fallah; Akbarzadeh, Abolfazl; Farshbaf, Masoud

    2017-02-01

    Gold nanoparticles (AuNPs) due to their unique properties and manifold surface functionalities have been applied in bio-nanotechnology. The application of GNPs in recent medical and biological research is very extensive. Especially it involves applications such as detection and photothermalysis of microorganisms and cancer stem cells, biosensors; optical bio-imaging and observing of cells and these nanostructures also serve as practical platforms for therapeutic agents. In this review we studied all therapeutic applications of gold nanoparticles in biomedicine, synthesis methods, and surface properties. © Georg Thieme Verlag KG Stuttgart · New York.

  2. Molecular Targets in Alzheimer’s Disease: From Pathogenesis to Therapeutics

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    Xuan Cheng

    2015-01-01

    Full Text Available Alzheimer’s disease (AD is characterized by progressive cognitive decline usually beginning with impairment in the ability to form recent memories. Nonavailability of definitive therapeutic strategy urges developing pharmacological targets based on cell signaling pathways. A great revival of interest in nutraceuticals and adjuvant therapy has been put forward. Tea polyphenols for their multiple health benefits have also attracted the attention of researchers. Tea catechins showed enough potentiality to be used in future as therapeutic targets to provide neuroprotection against AD. This review attempts to present a concise map of different receptor signaling pathways associated with AD with an insight into drug designing based on the proposed signaling pathways, molecular mechanistic details of AD pathogenesis, and a scientific rationale for using tea polyphenols as proposed therapeutic agents in AD.

  3. Decorporation of metal ions by chelating agents

    International Nuclear Information System (INIS)

    Koenig, T.

    1978-01-01

    Simple model designs to simulate the effect of therapeutical chelating agents on the behaviour of metals in mammal organisms with and without excretion have been derived and analytical solutions given for the corresponding differential equations. The possibilities of these models in the short-term description of plasma kinetics of various metals, the competition of the therapeutical ligands with proteins for the metal and of the metabolism of chelating agents were tested and the properties applying extreme conceivable parameters were analyzed. The simple models were successsively expanded in logical sequence, so that it was possible to qualitatively well describe over a long period of time, the metallic kinetics in plasma, organs and urine, the retention of the ligands and their effect on the metal excretion. Two suggestions were given to describe the so-called after-effect, an increased excretion of the metal at times when the ligand is almost completely excreted and their different behaviour after injecting the metal chelate is given. Calculations on the therapy with several ligand data as well as on dose fractionation are described resting on the ratios in the plutonium-239 chosen model parameters and the determining mechanisms analyzed. (orig./MG) [de

  4. Molecular Characterization of Gastric Carcinoma: Therapeutic Implications for Biomarkers and Targets

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    Lionel Kankeu Fonkoua

    2018-03-01

    Full Text Available Palliative chemotherapy is the mainstay of treatment of advanced gastric carcinoma (GC. Monoclonal antibodies including trastuzumab, ramucirumab, and pembrolizumab have been shown to provide additional benefits. However, the clinical outcomes are often unpredictable and they can vary widely among patients. Currently, no biomarker is available for predicting treatment response in the individual patient except human epidermal growth factor receptor 2 (HER2 amplification and programmed death-ligand 1 (PD-L1 expression for effectiveness of trastuzumab and pembrolizumab, respectively. Multi-platform molecular analysis of cancer, including GC, may help identify predictive biomarkers to guide selection of therapeutic agents. Molecular classification of GC by The Cancer Genome Atlas Research Network and the Asian Cancer Research Group is expected to identify therapeutic targets and predictive biomarkers. Complementary to molecular characterization of GC is molecular profiling by expression analysis and genomic sequencing of tumor DNA. Initial analysis of patients with gastroesophageal carcinoma demonstrates that the ratio of progression-free survival (PFS on molecular profile (MP-based treatment to PFS on treatment prior to molecular profiling exceeds 1.3, suggesting the potential value of MP in guiding selection of individualized therapy. Future strategies aiming to integrate molecular classification and profiling of tumors with therapeutic agents for achieving the goal of personalized treatment of GC are indicated.

  5. Molecular Characterization of Gastric Carcinoma: Therapeutic Implications for Biomarkers and Targets.

    Science.gov (United States)

    Kankeu Fonkoua, Lionel; Yee, Nelson S

    2018-03-09

    Palliative chemotherapy is the mainstay of treatment of advanced gastric carcinoma (GC). Monoclonal antibodies including trastuzumab, ramucirumab, and pembrolizumab have been shown to provide additional benefits. However, the clinical outcomes are often unpredictable and they can vary widely among patients. Currently, no biomarker is available for predicting treatment response in the individual patient except human epidermal growth factor receptor 2 (HER2) amplification and programmed death-ligand 1 (PD-L1) expression for effectiveness of trastuzumab and pembrolizumab, respectively. Multi-platform molecular analysis of cancer, including GC, may help identify predictive biomarkers to guide selection of therapeutic agents. Molecular classification of GC by The Cancer Genome Atlas Research Network and the Asian Cancer Research Group is expected to identify therapeutic targets and predictive biomarkers. Complementary to molecular characterization of GC is molecular profiling by expression analysis and genomic sequencing of tumor DNA. Initial analysis of patients with gastroesophageal carcinoma demonstrates that the ratio of progression-free survival (PFS) on molecular profile (MP)-based treatment to PFS on treatment prior to molecular profiling exceeds 1.3, suggesting the potential value of MP in guiding selection of individualized therapy. Future strategies aiming to integrate molecular classification and profiling of tumors with therapeutic agents for achieving the goal of personalized treatment of GC are indicated.

  6. Curcumin as potential therapeutic natural product: a nanobiotechnological perspective.

    Science.gov (United States)

    Shome, Soumitra; Talukdar, Anupam Das; Choudhury, Manabendra Dutta; Bhattacharya, Mrinal Kanti; Upadhyaya, Hrishikesh

    2016-12-01

    Nanotechnology-based drug delivery systems can resolve the poor bioavailability issue allied with curcumin. The therapeutic potential of curcumin can be enhanced by making nanocomposite preparation of curcumin with metal oxide nanoparticles, poly lactic-co-glycolic acid (PLGA) nanoparticles and solid lipid nanoparticles that increases its bioavailability in the tissue. Curcumin has manifold therapeutic effects which include antidiabetic, antihypertensive, anticancer, anti-inflammatory and antimicrobial properties. Curcumin can inhibit diabetes, heavy metal and stress-induced hypertension with its antioxidant, chelating and inhibitory effects on the pathways that lead to hypertension. Curcumin is an anticancer agent that can prevent abnormal cell proliferation. Nanocurcumin is an improved form of curcumin with enhanced therapeutic properties due to improved delivery to the diseased tissue, better internalization and reduced systemic elimination. Curcumin has multiple pharmacologic effects, but its poor bioavailability reduces its therapeutic effects. By conjugating curcumin to metal oxide nanoparticles or encapsulation in lipid nanoparticles, dendrimers, nanogels and polymeric nanoparticles, the water solubility and bioavailability of curcumin can be improved and thus increase its pharmacological effectiveness. © 2016 Royal Pharmaceutical Society.

  7. Tools for predicting the PK/PD of therapeutic proteins.

    Science.gov (United States)

    Diao, Lei; Meibohm, Bernd

    2015-07-01

    Assessments of the pharmacokinetic/pharmacodynamic (PK/PD) characteristics are an integral part in the development of novel therapeutic agents. Compared with traditional small molecule drugs, therapeutic proteins possess many distinct PK/PD features that necessitate the application of modified or separate approaches for assessing their PK/PD relationships. In this review, the authors discuss tools that are utilized to describe and predict the PK/PD features of therapeutic proteins and that are valuable additions in the armamentarium of drug development approaches to facilitate and accelerate their successful preclinical and clinical development. A variety of state-of-the-art PK/PD tools is currently being applied and has been adjusted to support the development of proteins as therapeutics, including allometric scaling approaches, target-mediated disposition models, first-in-man dose calculations, physiologically based PK models and empirical and semi-mechanistic PK/PD modeling. With the advent of the next generation of biologics including bioengineered antibody constructs being developed, these tools will need to be further refined and adapted to ensure their applicability and successful facilitation of the drug development process for these novel scaffolds.

  8. 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. ©2015 Frontline Medical Communications.

  9. Development of radiolanthanide labeled porphyrin complexes as possible therapeutic agents in beast carcinoma xenografts

    Energy Technology Data Exchange (ETDEWEB)

    Vahidfar, Nasim; Aghanejad, Ayuob; Beiki, Davood; Khalaj, Ali [Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of). Faculty of Pharmacy; Jalilian, Amir R.; Fazaeli, Yousef; Bahrami-Samani, Ali; Alirezapour, Behrooz; Erfani, Mostafa [Nuclear Science and Technology Research Institute, Tehran (Iran, Islamic Republic of). Radiopharmacy Research Group

    2014-10-01

    Radiolabeled porphyrins are potential tumor avid radiopharmaceuticals because of their behaviour in the human body, ability to complex various radionuclides, water solubility, low toxicity etc., in this work radio ytterbium/samarium porphyrin complexes have been developed. {sup 175}Yb and {sup 153}Sm labeled 5,10,15,20-tetrakis(3,4-dimethoxyphenyl) porphyrins ([{sup 175}Yb]-TDMPP/[{sup 153}Sm]-TDMPP) were prepared using 5,10,15,20-tetrakis(3,4-dimethoxyphenyl) porphyrin (H{sub 2}TDMPP) and [{sup 175}Yb]YbCl{sub 3} or [{sup 153}Sm]SmCl{sub 3} in 12-24 h at 60 C. Stability of the complexes were checked in final formulation and human serum for 24 h, followed by partition coefficient determination and biodistribution studies in wild type and breast carcinoma-bearing mice. The radiocomplexes were obtained with acceptable radiochemical purity (> 95% (paper chromatography) and > 96% (HPLC) for [{sup 175}Yb]-TDMPP and > 97% (paper chromatography) and > 98% (HPLC) for [{sup 153}Sm]-TDMPP) with specific activities of 12-15 GBq/mmol and 278 GBq/mmol at the end of bombardment for [{sup 175}Yb]-TDMPP and [{sup 153}Sm]-TDMPP respectively. The partition coefficients were determined for [{sup 175}Yb]-TDMPP and [{sup 153}Sm]-TDMPP (log P = 0.63 and log P = 0.96 respectively). The [{sup 175}Yb]-TDMPP complex is mostly washed out from the circulation through kidneys. Liver and spleen also demonstrated significant activity uptake in 72 h post injection. Also [{sup 153}Sm]-TDMPP, is mostly washed out from the circulation through kidneys, however lungs are the major accumulation sites. The [{sup 153}Sm]-TDMPP complex demonstrated significant targeted uptake in breast carcinoma xenografts with tumor: blood ratios of 10.67, 10.47 and 19.01 in 24, 48 and 72 h respectively. Also interesting tumor: kidney/liver ratios were obtained. {sup 153}Sm-TDMPP properties suggest an efficient tumor targeting agent with high tumor-avidity. Further investigation on the therapeutic properties must be

  10. Prevalence of acid-reducing agents (ARA) in cancer populations and ARA drug-drug interaction potential for molecular targeted agents in clinical development.

    Science.gov (United States)

    Smelick, Gillian S; Heffron, Timothy P; Chu, Laura; Dean, Brian; West, David A; Duvall, Scott L; Lum, Bert L; Budha, Nageshwar; Holden, Scott N; Benet, Leslie Z; Frymoyer, Adam; Dresser, Mark J; Ware, Joseph A

    2013-11-04

    Acid-reducing agents (ARAs) are the most commonly prescribed medications in North America and Western Europe. There are currently no data describing the prevalence of their use among cancer patients. However, this is a paramount question due to the potential for significant drug-drug interactions (DDIs) between ARAs, most commonly proton pump inhibitors (PPIs), and orally administered cancer therapeutics that display pH-dependent solubility, which may lead to decreased drug absorption and decreased therapeutic benefit. Of recently approved orally administered cancer therapeutics, >50% are characterized as having pH-dependent solubility, but there are currently no data describing the potential for this ARA-DDI liability among targeted agents currently in clinical development. The objectives of this study were to (1) determine the prevalence of ARA use among different cancer populations and (2) investigate the prevalence of orally administered cancer therapeutics currently in development that may be liable for an ARA-DDI. To address the question of ARA use among cancer patients, a retrospective cross-sectional analysis was performed using two large healthcare databases: Thomson Reuters MarketScan (N = 1,776,443) and the U.S. Department of Veterans Affairs (VA, N = 1,171,833). Among all cancer patients, the total prevalence proportion of ARA use (no. of cancer patients receiving an ARA/total no. of cancer patients) was 20% and 33% for the MarketScan and VA databases, respectively. PPIs were the most commonly prescribed agent, comprising 79% and 65% of all cancer patients receiving a prescription for an ARA (no. of cancer patients receiving a PPI /no. of cancer patients receiving an ARA) for the MarketScan and VA databases, respectively. To estimate the ARA-DDI liability of orally administered molecular targeted cancer therapeutics currently in development, two publicly available databases, (1) Kinase SARfari and (2) canSAR, were examined. For those orally administered

  11. A 3D intestinal tissue model supports Clostridioides difficile germination, colonization, toxin production and epithelial damage.

    Science.gov (United States)

    Shaban, Lamyaa; Chen, Ying; Fasciano, Alyssa C; Lin, Yinan; Kaplan, David L; Kumamoto, Carol A; Mecsas, Joan

    2018-04-01

    Endospore-forming Clostridioides difficile is a causative agent of antibiotic-induced diarrhea, a major nosocomial infection. Studies of its interactions with mammalian tissues have been hampered by the fact that C. difficile requires anaerobic conditions to survive after spore germination. We recently developed a bioengineered 3D human intestinal tissue model and found that low O 2 conditions are produced in the lumen of these tissues. Here, we compared the ability of C. difficile spores to germinate, produce toxin and cause tissue damage in our bioengineered 3D tissue model versus in a 2D transwell model in which human cells form a polarized monolayer. 3D tissue models or 2D polarized monolayers on transwell filters were challenged with the non-toxin producing C. difficile CCUG 37787 serotype X (ATCC 43603) and the toxin producing UK1 C. difficile spores in the presence of the germinant, taurocholate. Spores germinated in both the 3D tissue model as well as the 2D transwell system, however toxin activity was significantly higher in the 3D tissue models compared to the 2D transwells. Moreover, the epithelium damage in the 3D tissue model was significantly more severe than in 2D transwells and damage correlated significantly with the level of toxin activity detected but not with the amount of germinated spores. Combined, these results show that the bioengineered 3D tissue model provides a powerful system with which to study early events leading to toxin production and tissue damage of C. difficile with mammalian cells under anaerobic conditions. Furthermore, these systems may be useful for examining the effects of microbiota, novel drugs and other potential therapeutics directed towards C. difficile infections. Copyright © 2018 Elsevier Ltd. All rights reserved.

  12. Gap junctions and hemichannels composed of connexins: potential therapeutic targets for neurodegenerative diseases

    Directory of Open Access Journals (Sweden)

    Hideyuki eTakeuchi

    2014-09-01

    Full Text Available Microglia are macrophage-like resident immune cells that contribute to the maintenance of homeostasis in the central nervous system (CNS. Abnormal activation of microglia can cause damage in the CNS, and accumulation of activated microglia is a characteristic pathological observation in neurologic conditions such as trauma, stroke, inflammation, epilepsy, and neurodegenerative diseases. Activated microglia secrete high levels of glutamate, which damages CNS cells and has been implicated as a major cause of neurodegeneration in these conditions. Glutamate-receptor blockers and microglia inhibitors (e.g. minocycline have been examined as therapeutic candidates for several neurodegenerative diseases; however, these compounds exerted little therapeutic benefit because they either perturbed physiological glutamate signals or suppressed the actions of protective microglia. The ideal therapeutic approach would hamper the deleterious roles of activated microglia without diminishing their protective effects. We recently found that abnormally activated microglia secrete glutamate via gap-junction hemichannels on the cell surface. Moreover, administration of gap-junction inhibitors significantly suppressed excessive microglial glutamate release and improved disease symptoms in animal models of neurologic conditions such as stroke, multiple sclerosis, amyotrophic lateral sclerosis, and Alzheimer’s disease. Recent evidence also suggests that neuronal and glial communication via gap junctions amplifies neuroinflammation and neurodegeneration. Elucidation of the precise pathologic roles of gap junctions and hemichannels may lead to a novel therapeutic strategies that can slow and halt the progression of neurodegenerative diseases.

  13. Inactivating UBE2M impacts the DNA damage response and genome integrity involving multiple cullin ligases.

    Directory of Open Access Journals (Sweden)

    Scott Cukras

    Full Text Available Protein neddylation is involved in a wide variety of cellular processes. Here we show that the DNA damage response is perturbed in cells inactivated with an E2 Nedd8 conjugating enzyme UBE2M, measured by RAD51 foci formation kinetics and cell based DNA repair assays. UBE2M knockdown increases DNA breakages and cellular sensitivity to DNA damaging agents, further suggesting heightened genomic instability and defective DNA repair activity. Investigating the downstream Cullin targets of UBE2M revealed that silencing of Cullin 1, 2, and 4 ligases incurred significant DNA damage. In particular, UBE2M knockdown, or defective neddylation of Cullin 2, leads to a blockade in the G1 to S progression and is associated with delayed S-phase dependent DNA damage response. Cullin 4 inactivation leads to an aberrantly high DNA damage response that is associated with increased DNA breakages and sensitivity of cells to DNA damaging agents, suggesting a DNA repair defect is associated. siRNA interrogation of key Cullin substrates show that CDT1, p21, and Claspin are involved in elevated DNA damage in the UBE2M knockdown cells. Therefore, UBE2M is required to maintain genome integrity by activating multiple Cullin ligases throughout the cell cycle.

  14. Inactivating UBE2M impacts the DNA damage response and genome integrity involving multiple cullin ligases.

    Science.gov (United States)

    Cukras, Scott; Morffy, Nicholas; Ohn, Takbum; Kee, Younghoon

    2014-01-01

    Protein neddylation is involved in a wide variety of cellular processes. Here we show that the DNA damage response is perturbed in cells inactivated with an E2 Nedd8 conjugating enzyme UBE2M, measured by RAD51 foci formation kinetics and cell based DNA repair assays. UBE2M knockdown increases DNA breakages and cellular sensitivity to DNA damaging agents, further suggesting heightened genomic instability and defective DNA repair activity. Investigating the downstream Cullin targets of UBE2M revealed that silencing of Cullin 1, 2, and 4 ligases incurred significant DNA damage. In particular, UBE2M knockdown, or defective neddylation of Cullin 2, leads to a blockade in the G1 to S progression and is associated with delayed S-phase dependent DNA damage response. Cullin 4 inactivation leads to an aberrantly high DNA damage response that is associated with increased DNA breakages and sensitivity of cells to DNA damaging agents, suggesting a DNA repair defect is associated. siRNA interrogation of key Cullin substrates show that CDT1, p21, and Claspin are involved in elevated DNA damage in the UBE2M knockdown cells. Therefore, UBE2M is required to maintain genome integrity by activating multiple Cullin ligases throughout the cell cycle.

  15. Delivery of Therapeutic Proteins Using Electrospun Fibers-Recent Developments and Current Challenges.

    Science.gov (United States)

    Seif, Salem; Planz, Viktoria; Windbergs, Maike

    2017-10-01

    Proteins play a vital role within the human body by regulating various functions and even serving as structural constituent of many body parts. In this context, protein-based therapeutics have attracted a lot of attention in the last few decades as potential treatment of different diseases. Due to the steadily increasing interest in protein-based therapeutics, different dosage forms were investigated for delivering such complex macromolecules to the human body. Here, electrospun fibers hold a great potential for embedding proteins without structural damage and for controlled release of the protein for therapeutic applications. This review provides a comprehensive overview of the current state of protein-based carrier systems using electrospun fibers, with special emphasis on discussing their potential and key challenges in developing such therapeutic strategies, along with a prospective view of anticipated future directions. © 2017 Deutsche Pharmazeutische Gesellschaft.

  16. Protein Changes in Sulfur Mustard Exposure: Diagnostic and Therapeutic Implications

    International Nuclear Information System (INIS)

    Ray, P.; Jin, X.; Ray, R.

    2007-01-01

    Laminin-5, a heterotrimer of laminin α3, β3, and γ2 subunits, is a component of the skin basal epithelium. Laminin-5 functions as a ligand of the α3β1 and α6β4 integrins in epidermal keratinocytes to regulate cell adhesion, migration, morphogenesis, and assembly of basement membranes; thus it is essential for a stable attachment of the epidermis to the dermis and recovery of damaged skin. Sulfur mustard (SM), also known as mustard gas, is a vesicant chemical warfare and terrorism agent. Skin exposure to SM results in fluid-filled blisters; proposed mechanisms are inflammation, protease stimulation, basal cell death, and separation of the epidermis from the dermis apparently due to the degradation of attachment proteins like laminin-5. Therefore, we investigated the effects of SM exposure on the degradation of laminin-5 by exposing normal human epidermal keratinocytes (NHEK) to SM (0-300 μM, 1-24 hours). We found that SM degraded laminin-5 and its two subunits β3 and γ2, but not α3. Preincubation of cells with a serine protease inhibitor (PMSF), or a metalloprotease inhibitor (1, 10-phenanthroline) prior to SM exposure partially prevented SM-induced degradation of laminin-5 subunits, β3 and γ2. Regarding specificity, laminin-5 γ2 was degraded due to a bifunctional mustard compound like SM, but not due to the other alkylating agents tested. Our results support that laminin-5 degradation is an important mechanism of SM injury as well as a useful biomarker of SM exposure. This knowledge of the mechanism of laminin-5 degradation due to SM has potential application in developing cutaneous therapeutics against SM.(author)

  17. Discriminating between absorption and scattering coefficients in optical characterisation measurements on gold nanoparticle based photoacoustic contrast agents

    NARCIS (Netherlands)

    Ungureanu, C.; Manohar, Srirang; van Leeuwen, Ton; Amelink, A.; Sterenborg, Henricus J.C.M.; Oraevsky, Alexander A.; Wang, Lihong V.

    2009-01-01

    Plasmon resonant nanoparticles such as gold nanoshells and gold nanorods can be tuned to possess sharp interaction peaks in the near-infrared wavelength regions. These have great importance as contrast agents in photoacoustic imaging and as photothermal agents for therapeutic applications due to

  18. Usefulness of radiatively obtained acrylamide polymers for production of drug forms with controlled release of the therapeutic component

    International Nuclear Information System (INIS)

    Mosiniak, T.; Switek, W.

    1988-01-01

    Using 60 Co gamma radiation as a factor initiating polymerization and cross-linking of polymers, polyacrylamide matrices were formed with the following therapeutic agents: aspirin, amidopyrin, sodium salicylate. Gamma radiation doses ranged from 3.5 to 22.5 kGy, dose rate was 0.138 Gy x s -1 . Kinetics of the therapeutic agent release from the matrix polymers was determined by measurement of per cent of the drug release in the course of time and calculations of release rate constants. The preparations containing slowly released drugs were obtained. 12 figs., 2 tabs., 11 refs. (author)

  19. Repair of DNA damage induced by ionizing radiation and benzo[a]pyrene in mammalian cells

    International Nuclear Information System (INIS)

    Cerutti, P.; Shinohara, K.; Remsen, J.

    1977-01-01

    The biological effects of DNA-damaging agents are codetermined by the structural characteristics of the lesions, the quality and extent of the local distortion of DNA and chromatin structure, and the mode(s) of damage processing used by a given type of cell. Persistent damage (i.e., damage that is not removed before it is reached by DNA replication) may be mostly responsible for mutagenesis and carcinogenesis. To understand the effects of environmental physical and chemical DNA-damaging agents on human health, the mechanisms of damage processing used by human cells have to be elucidated. We report our studies of the excision of gamma-ray products of the 5,6-dihydroxydihydrothymine type (t 0 /sub 2//sup γ/) in normal human fibroblasts and in fibroblasts from patients with the hereditary diseases Fanconi's anemia (FA) and ataxia telangiectasia (AT). Both diseases are characterized by chromosomal instability and increased susceptibility for the development of cancer. Formation and repair of DNA-benzo[a]pyrene adducts were studied in baby hamster kidney cells, secondary mouse embryo cells, and human lymphoma. The relative persistence of DNA-B[a]P may explain the high mutagenicity of the 7,8-dihydroxy-9,10-epoxy-tetrahydrobenzo[a]pyrene metabolites in rodent cells that has been observed by several investigators

  20. Unexpected fatal neurological deterioration after successful cardio-pulmonary resuscitation and therapeutic hypothermia.

    NARCIS (Netherlands)

    Bergman, R.; Tjan, D.H.; Adriaanse, M.W.; Vugt, R. van; Zanten, A.R. van

    2008-01-01

    A 77-year-old woman was admitted to the intensive care unit after successful cardiopulmonary resuscitation for out-of-hospital cardiac arrest due to pulseless electrical activity. She was treated with mild therapeutic hypothermia to minimise secondary anoxic brain damage. After a 24 h period of

  1. Antibody-Based Agents in the Management of Antibiotic-Resistant Staphylococcus aureus Diseases

    Science.gov (United States)

    Speziale, Pietro; Rindi, Simonetta

    2018-01-01

    Staphylococcus aureus is a human pathogen that can cause a wide spectrum of diseases, including sepsis, pneumonia, arthritis, and endocarditis. Ineffective treatment of a number of staphylococcal infections with antibiotics is due to the development and spread of antibiotic-resistant strains following decades of antibiotic usage. This has generated renewed interest within the scientific community in alternative therapeutic agents, such as anti-S. aureus antibodies. Although the role of antibodies in the management of S. aureus diseases is controversial, the success of this pathogen in neutralizing humoral immunity clearly indicates that antibodies offer the host extensive protection. In this review, we report an update on efforts to develop antibody-based agents, particularly monoclonal antibodies, and their therapeutic potential in the passive immunization approach to the treatment and prevention of S. aureus infections. PMID:29533985

  2. Characterization of glioma stem cells through multiple stem cell markers and their specific sensitization to double-strand break-inducing agents by pharmacological inhibition of ataxia telangiectasia mutated protein.

    Science.gov (United States)

    Raso, Alessandro; Vecchio, Donatella; Cappelli, Enrico; Ropolo, Monica; Poggi, Alessandro; Nozza, Paolo; Biassoni, Roberto; Mascelli, Samantha; Capra, Valeria; Kalfas, Fotios; Severi, Paolo; Frosina, Guido

    2012-09-01

    Previous studies have shown that tumor-driving glioma stem cells (GSC) may promote radio-resistance by constitutive activation of the DNA damage response started by the ataxia telangiectasia mutated (ATM) protein. We have investigated whether GSC may be specifically sensitized to ionizing radiation by inhibiting the DNA damage response. Two grade IV glioma cell lines (BORRU and DR177) were characterized for a number of immunocytochemical, karyotypic, proliferative and differentiative parameters. In particular, the expression of a panel of nine stem cell markers was quantified by reverse transcription-polymerase chain reaction (RT-PCR) and flow cytometry. Overall, BORRU and DR177 displayed pronounced and poor stem phenotypes, respectively. In order to improve the therapeutic efficacy of radiation on GSC, the cells were preincubated with a nontoxic concentration of the ATM inhibitors KU-55933 and KU-60019 and then irradiated. BORRU cells were sensitized to radiation and radio-mimetic chemicals by ATM inhibitors whereas DR177 were protected under the same conditions. No sensitization was observed after cell differentiation or to drugs unable to induce double-strand breaks (DSB), indicating that ATM inhibitors specifically sensitize glioma cells possessing stem phenotype to DSB-inducing agents. In conclusion, pharmacological inhibition of ATM may specifically sensitize GSC to DSB-inducing agents while sparing nonstem cells. © 2012 The Authors; Brain Pathology © 2012 International Society of Neuropathology.

  3. 3D culture of Her2+ breast cancer cells promotes AKT to MAPK switching and a loss of therapeutic response.

    Science.gov (United States)

    Gangadhara, Sharath; Smith, Chris; Barrett-Lee, Peter; Hiscox, Stephen

    2016-06-01

    The Her2 receptor is overexpressed in up to 25 % of breast cancers and is associated with a poor prognosis. Around half of Her2+ breast cancers also express the estrogen receptor and treatment for such tumours can involve both endocrine and Her2-targeted therapies. However, despite preclinical data supporting the effectiveness of these agents, responses can vary widely in the clinical setting. In light of the increasing evidence pointing to the interplay between the tumour and its extracellular microenvironment as a significant determinant of therapeutic sensitivity and response here we investigated the impact of 3D matrix culture of breast cancer cells on their therapeutic sensitivity. A 3D Matrigel-based culture system was established and optimized for the growth of ER+/Her2+ breast cancer cell models. Growth of cells in response to trastuzumab and endocrine agents in 3D culture versus routine monolayer culture were assessed using cell counting and Ki67 staining. Endogenous and trastuzumab-modulated signalling pathway activity in 2D and 3D cultures were assessed using Western blotting. Breast cancer cells in 3D culture displayed an attenuated response to both endocrine agents and trastuzumab compared with cells cultured in traditional 2D monolayers. Underlying this phenomenon was an apparent matrix-induced shift from AKT to MAPK signalling; consequently, suppression of MAPK in 3D cultures restores therapeutic response. These data suggest that breast cancer cells in 3D culture display a reduced sensitivity to therapeutic agents which may be mediated by internal MAPK-mediated signalling. Targeting of adaptive pathways that maintain growth in 3D culture may represent an effective strategy to improve therapeutic response clinically.

  4. Expression of assayable residual stem cell damage in erythroid differentiation

    International Nuclear Information System (INIS)

    Huebner, G.E.; Miller, M.E.; Cronkite, E.P.

    1985-01-01

    In rodents, residual damage is inducible in hematopoietic stem cells by exposure to ionizing radiation or alkylating agents. This damage can b e assayed in mice by transferring bone marrow into lethally irradiated syngeneic recipients and subsequently measuring the incremental increase of-( 125 I)iodo-2'-deoxyuridine incorporation in spleens. In this study, bone marrow from mice treated 3 weeks previously with Methylnitrosourea (50 mg/kg) or 450 rad was injected into recipients in order to determine possible residual effects of treatment of erythroid cell differentiation following stem cell seeding. Such effects were detected by a reduced amount of 59 Fe incorporation into spleens, thus indicatin g transfer of residual stem cell damage to differentiating cells. (orig.)

  5. Detection of DNA damage induced in vivo by a cross-linking agent with a circular channel crucible oscillating viscometer.

    Science.gov (United States)

    Balbi, C; Abelmoschi, M L; Roner, R; Giaretti, W; Parodi, S; Santi, L

    1985-11-01

    DNA damage induced in vivo by the cross-linking agent mitomycin C (MMC) was investigated with a new oscillating crucible viscometer. Viscosity was measured by lysing rat liver nuclei in an alkaline lysing solution (pH 12.5; 25 degrees C). In control samples the viscosity increased very slowly with time, reaching a plateau only after 10-12 h. The process was accelerated and the maximum viscosity was decreased by alkaline single-stranded breaks arising from methylation and subsequent depurination of DNA in vitro with dimethylsulphate (DMS). MMC, when given alone, had no evident effect on the time needed for reaching plateau viscosity but it induced a small increase in maximum viscosity. When MMC was given in association with DMS, the time of disentanglement remained unchanged (accelerated) but maximum viscosity was increased in a dose dependent way. We conclude that these data clearly confirm that the slow steady increase of the viscosity of control DNA with time reflects mainly the process of unwinding of the two strands. The speed of this process seems to depend only from the number of unwinding points in DNA (breaks).

  6. Old and new challenges in Parkinson's disease therapeutics.

    Science.gov (United States)

    Pires, Ana O; Teixeira, F G; Mendes-Pinheiro, B; Serra, Sofia C; Sousa, Nuno; Salgado, António J

    2017-09-01

    Parkinson's disease (PD) is a neurodegenerative disorder characterized by the degeneration of dopaminergic neurons and/or loss od neuronal projections, in several dopaminergic networks. Current treatments for idiopathic PD rely mainly on the use of pharmacologic agents to improve motor symptomatology of PD patients. Nevertheless, so far PD remains an incurable disease. Therefore, it is of utmost importance to establish new therapeutic strategies for PD treatment. Over the last 20 years, several molecular, gene and cell/stem-cell therapeutic approaches have been developed with the aim of counteracting or retarding PD progression. The scope of this review is to provide an overview of PD related therapies and major breakthroughs achieved within this field. In order to do so, this review will start by focusing on PD characterization and current treatment options covering thereafter molecular, gene and cell/stem cell-based therapies that are currently being studied in animal models of PD or have recently been tested in clinical trials. Among stem cell-based therapies, those using MSCs as possible disease modifying agents for PD therapy and, specifically, the MSCs secretome contribution to meet the clinical challenge of counteracting or retarding PD progression, will be more deeply explored. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. 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.

  8. The Role of Damage-Associated Molecular Patterns (DAMPs in Human Diseases; Part II: DAMPs as diagnostics, prognostics and therapeutics in clinical medicine

    Directory of Open Access Journals (Sweden)

    Walter G. Land

    2015-05-01

    Full Text Available This article is the second part of a review that addresses the role of damage-associated molecular patterns (DAMPs in human diseases by presenting examples of traumatic (systemic inflammatory response syndrome, cardiovascular (myocardial infarction, metabolic (type 2 diabetes mellitus, neurodegenerative (Alzheimer’s disease, malignant and infectious diseases. Various DAMPs are involved in the pathogenesis of all these diseases as they activate innate immune machineries including the unfolded protein response and inflammasomes. These subsequently promote sterile autoinflammation accompanied, at least in part, by subsequent adaptive autoimmune processes. This review article discusses the future role of DAMPs in routine practical medicine by highlighting the possibility of harnessing and deploying DAMPs either as biomarkers for the appropriate diagnosis and prognosis of diseases, as therapeutics in the treatment of tumours or as vaccine adjuncts for the prophylaxis of infections. In addition, this article examines the potential for developing strategies aimed at mitigating DAMPs-mediated hyperinflammatory responses, such as those seen in systemic inflammatory response syndrome associated with multiple organ failure.

  9. Report on the Technical Meeting on Therapeutic Radiopharmaceuticals

    International Nuclear Information System (INIS)

    2009-01-01

    The purpose of the TM was to provide an experts' platform to facilitate exploring the current status and future directions on therapeutic radiopharmaceuticals. The invited talks and presentations in the TM were in the following topics: - Radionuclide Production; - Production and availability of alpha emitters and their radiopharmaceuticals; - Therapeutic radiopharmaceutical chemistry; - Targets and biological evaluation; - Medical physics and dosimetry; - Clinical applications including radioimmunotherapy and clinical needs; - Peptide receptor mediated therapy Panel discussions: - Radionuclide therapy using alpha emitters; - Regulatory challenges with therapeutic radiopharmaceuticals; - International activities in radionuclide therapy. he technical meeting generated a large interest among scientists and physicians working in the field of targeted therapy using radiopharmaceuticals. Participants from both developed and developing MS reported on recent developments on the research work and clinical studies going on in the field and provided their views on the future developments in this field. The unexpected high number of participants and the high number of presentations with exceptional quality underlines the great interest of scientists and professionals in therapeutic applications using radiolabelled drugs / biomolecules. The intensive discussions including panels specified the challenges in the future on developing novel agents and to finally use them for the benefit of patients. The IAEA can play as vital role in streamlining developments and to provide tools to overcome scientific, professional and regulatory challenges in the field of therapeutic radiopharmaceuticals

  10. Report on the Technical Meeting on Therapeutic Radiopharmaceuticals

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2009-07-01

    The purpose of the TM was to provide an experts' platform to facilitate exploring the current status and future directions on therapeutic radiopharmaceuticals. The invited talks and presentations in the TM were in the following topics: - Radionuclide Production; - Production and availability of alpha emitters and their radiopharmaceuticals; - Therapeutic radiopharmaceutical chemistry; - Targets and biological evaluation; - Medical physics and dosimetry; - Clinical applications including radioimmunotherapy and clinical needs; - Peptide receptor mediated therapy Panel discussions: - Radionuclide therapy using alpha emitters; - Regulatory challenges with therapeutic radiopharmaceuticals; - International activities in radionuclide therapy. he technical meeting generated a large interest among scientists and physicians working in the field of targeted therapy using radiopharmaceuticals. Participants from both developed and developing MS reported on recent developments on the research work and clinical studies going on in the field and provided their views on the future developments in this field. The unexpected high number of participants and the high number of presentations with exceptional quality underlines the great interest of scientists and professionals in therapeutic applications using radiolabelled drugs / biomolecules. The intensive discussions including panels specified the challenges in the future on developing novel agents and to finally use them for the benefit of patients. The IAEA can play as vital role in streamlining developments and to provide tools to overcome scientific, professional and regulatory challenges in the field of therapeutic radiopharmaceuticals

  11. Dunnione ameliorates cisplatin-induced small intestinal damage by modulating NAD{sup +} metabolism

    Energy Technology Data Exchange (ETDEWEB)

    Pandit, Arpana; Kim, Hyung-Jin; Oh, Gi-Su; Shen, AiHua; Lee, Su-Bin; Khadka, Dipendra; Lee, SeungHoon [Center for Metabolic Function Regulation & Department of Microbiology, Wonkwang University, Iksan, Jeonbuk 570-749 (Korea, Republic of); Shim, Hyeok; Yang, Sei-Hoon; Cho, Eun-Young [Department of Internal Medicine, School of Medicine, Wonkwang University, Iksan, Jeonbuk 570-749 (Korea, Republic of); Kwon, Kang-Beom [Department of Oriental Medical Physiology, School of Oriental Medicine, Wonkwang University, Iksan, Jeonbuk 570-749 (Korea, Republic of); Kwak, Tae Hwan [PAEAN Biotechnology, 160 Techno-2 Street, Yuseong-gu, Daejeon 305-500 (Korea, Republic of); Choe, Seong-Kyu; Park, Raekil [Center for Metabolic Function Regulation & Department of Microbiology, Wonkwang University, Iksan, Jeonbuk 570-749 (Korea, Republic of); So, Hong-Seob, E-mail: jeanso@wku.ac.kr [Center for Metabolic Function Regulation & Department of Microbiology, Wonkwang University, Iksan, Jeonbuk 570-749 (Korea, Republic of)

    2015-11-27

    Although cisplatin is a widely used anticancer drug for the treatment of a variety of tumors, its use is critically limited because of adverse effects such as ototoxicity, nephrotoxicity, neuropathy, and gastrointestinal damage. Cisplatin treatment increases oxidative stress biomarkers in the small intestine, which may induce apoptosis of epithelial cells and thereby elicit damage to the small intestine. Nicotinamide adenine dinucleotide (NAD{sup +}) is a cofactor for various enzymes associated with cellular homeostasis. In the present study, we demonstrated that the hyper-activation of poly(ADP-ribose) polymerase-1 (PARP-1) is closely associated with the depletion of NAD{sup +} in the small intestine after cisplatin treatment, which results in downregulation of sirtuin1 (SIRT1) activity. Furthermore, a decrease in SIRT1 activity was found to play an important role in cisplatin-mediated small intestinal damage through nuclear factor (NF)-κB p65 activation, facilitated by its acetylation increase. However, use of dunnione as a strong substrate for the NADH:quinone oxidoreductase 1 (NQO1) enzyme led to an increase in intracellular NAD{sup +} levels and prevented the cisplatin-induced small intestinal damage correlating with the modulation of PARP-1, SIRT1, and NF-κB. These results suggest that direct modulation of cellular NAD{sup +} levels by pharmacological NQO1 substrates could be a promising therapeutic approach for protecting against cisplatin-induced small intestinal damage. - Highlights: • NAD{sup +} acts as a cofactor for numerous enzymes including Sirtuins and PARP. • Up-regulation of SIRT1 could attenuate the cisplatin-induced intestinal damage. • Modulation of the cellular NAD{sup +} could be a promising therapeutic approach.

  12. Significance of antioxidant potential of plants and its relevance to therapeutic applications.

    Science.gov (United States)

    Kasote, Deepak M; Katyare, Surendra S; Hegde, Mahabaleshwar V; Bae, Hanhong

    2015-01-01

    Oxidative stress has been identified as the root cause of the development and progression of several diseases. Supplementation of exogenous antioxidants or boosting endogenous antioxidant defenses of the body is a promising way of combating the undesirable effects of reactive oxygen species (ROS) induced oxidative damage. Plants have an innate ability to biosynthesize a wide range of non-enzymatic antioxidants capable of attenuating ROS- induced oxidative damage. Several in vitro methods have been used to screen plants for their antioxidant potential, and in most of these assays they revealed potent antioxidant activity. However, prior to confirming their in vivo therapeutic efficacy, plant antioxidants have to pass through several physiopharmacological processes. Consequently, the findings of in vitro and in vivo antioxidant potential assessment studies are not always the same. Nevertheless, the results of in vitro assays have been irrelevantly extrapolated to the therapeutic application of plant antioxidants without undertaking sufficient in vivo studies. Therefore, we have briefly reviewed the physiology and redox biology of both plants and humans to improve our understanding of plant antioxidants as therapeutic entities. The applications and limitations of antioxidant activity measurement assays were also highlighted to identify the precise path to be followed for future research in the area of plant antioxidants.

  13. Biomedicines—Moving Biologic Agents into Approved Treatment Options

    Directory of Open Access Journals (Sweden)

    Kenneth Cornetta

    2013-03-01

    Full Text Available The development of biologic agents for therapeutic purposes, or biomedicines, has seen an active area of research both at the bench and in clinical trials. There is mounting evidence that biologic products can provide effective therapy for diseases that have been unresponsive to traditional pharmacologic approaches. Monoclonal antibody therapy for cancer and rheumatologic diseases has become a well accepted part of disease treatment plans. Gene therapy products have been approved in China and Europe. Bioengineering of new agents capitalizing on microRNA biology, nanoparticle technology, stem cell biology, and an increasing understanding of immunology predict a rich future for product development. [...

  14. Histone deacetylase inhibitors augment doxorubicin-induced DNA damage in cardiomyocytes.

    Science.gov (United States)

    Ververis, Katherine; Rodd, Annabelle L; Tang, Michelle M; El-Osta, Assam; Karagiannis, Tom C

    2011-12-01

    Histone deacetylase inhibitors have emerged as a new class of anticancer therapeutics with suberoylanilide hydroxamic acid (Vorinostat) and depsipeptide (Romidepsin) already being approved for clinical use. Numerous studies have identified that histone deacetylase inhibitors will be most effective in the clinic when used in combination with conventional cancer therapies such as ionizing radiation and chemotherapeutic agents. One promising combination, particularly for hematologic malignancies, involves the use of histone deacetylase inhibitors with the anthracycline, doxorubicin. However, we previously identified that trichostatin A can potentiate doxorubicin-induced hypertrophy, the dose-limiting side-effect of the anthracycline, in cardiac myocytes. Here we have the extended the earlier studies and evaluated the effects of combinations of the histone deacetylase inhibitors, trichostatin A, valproic acid and sodium butyrate on doxorubicin-induced DNA double-strand breaks in cardiomyocytes. Using γH2AX as a molecular marker for the DNA lesions, we identified that all of the broad-spectrum histone deacetylase inhibitors tested augment doxorubicin-induced DNA damage. Furthermore, it is evident from the fluorescence photomicrographs of stained nuclei that the histone deacetylase inhibitors also augment doxorubicin-induced hypertrophy. These observations highlight the importance of investigating potential side-effects, in relevant model systems, which may be associated with emerging combination therapies for cancer.

  15. Experience with leaf analysis in smoke damage tests

    Energy Technology Data Exchange (ETDEWEB)

    Garber, K

    1960-01-01

    The role of chemical analysis in examining plant material for damage caused by smoke is discussed. Most difficult is the diagnosis of SO/sub 2/ damage, even in case of leaf discoloration, because this symptom is not specific. An increased content of sulfur in leaves can be an indication of damage by SO/sub 2/ but this proof is not reliable, since plants can manifest elevated sulfur levels through intake from the soil. A quantitative micromethod for the detection of SO/sub 2/ in fresh leaves has been developed by G. Bredemann and H. Radeloff. Hydrochloric acid and chlorine can also be detected by a micromethod (AgNO/sub 3/) but there is no proof of damage because the natural chloride content in plants fluctuates widely. The same holds for NO/sub 2/ and NO/sub 3/. Ammonia can be detected microchemically with great reliability; fluorine can also be detected microchemically and positive tests usually indicate reliably the cause of damage, but the fluorine test is not always reliable. A microchemical test also exists for asphalt and tar vapors. Thus, if the circumstances of the damage and local conditions are known, microchemical leaf analysis is useful as an auxiliary method in attributing damage to a specific agent. But leaf analysis by itself does not constitute conclusive proof. 12 references.

  16. Salt stress causes cell wall damage in yeast cells lacking mitochondrial DNA.

    Science.gov (United States)

    Gao, Qiuqiang; Liou, Liang-Chun; Ren, Qun; Bao, Xiaoming; Zhang, Zhaojie

    2014-03-03

    The yeast cell wall plays an important role in maintaining cell morphology, cell integrity and response to environmental stresses. Here, we report that salt stress causes cell wall damage in yeast cells lacking mitochondrial DNA (ρ 0 ). Upon salt treatment, the cell wall is thickened, broken and becomes more sensitive to the cell wall-perturbing agent sodium dodecyl sulfate (SDS). Also, SCW11 mRNA levels are elevated in ρ 0 cells. Deletion of SCW11 significantly decreases the sensitivity of ρ 0 cells to SDS after salt treatment, while overexpression of SCW11 results in higher sensitivity. In addition, salt stress in ρ 0 cells induces high levels of reactive oxygen species (ROS), which further damages the cell wall, causing cells to become more sensitive towards the cell wall-perturbing agent.

  17. Quercetin in Cancer Treatment, Alone or in Combination with Conventional Therapeutics?

    Science.gov (United States)

    Brito, Ana Filipa; Ribeiro, Marina; Abrantes, Ana Margarida; Pires, Ana Salomé; Teixo, Ricardo Jorge; Tralhão, José Guilherme; Botelho, Maria Filomena

    2015-01-01

    Cancer is a problem of global importance, since the incidence is increasing worldwide and therapeutic options are generally limited. Thus, it becomes imperative to find new therapeutic targets as well as new molecules with therapeutic potential for tumors. Flavonoids are polyphenolic compounds that may be potential therapeutic agents. Several studies have shown that these compounds have a higher anticancer potential. Among the flavonoids in the human diet, quercetin is one of the most important. In the last decades, several anticancer properties of quercetin have been described, such as cell signaling, pro-apoptotic, anti-proliferative and anti-oxidant effects, growth suppression. In fact, it is now well known that quercetin has diverse biological effects, inhibiting multiple enzymes involved in cell proliferation, as well as, in signal transduction pathways. On the other hand, there are also studies reporting potential synergistic effects when combined quercetin with chemotherapeutic agents or radiotherapy. In fact, several studies which aim to explore the anticancer potential of these combined treatments have already been published, the majority with promising results. Actually it is well known that quercetin can act on the chemosensitization and radiosensitization but also as chemoprotective and radioprotective, protecting normal cells of the side effects that results from chemotherapy and radiotherapy, which obviously provides notable advantages in their use in anticancer treatment. Thus, all these data indicate that quercetin may have a key role in anticancer treatment. In this context, this review is focused on the relationship between flavonoids and cancer, with special emphasis on the role of quercetin.

  18. Degradation product characterization of therapeutic oligonucleotides using liquid chromatography mass spectrometry.

    Science.gov (United States)

    Elzahar, N M; Magdy, N; El-Kosasy, Amira M; Bartlett, Michael G

    2018-05-01

    Synthetic antisense phosphorothioate oligonucleotides (PS) have undergone rapid development as novel therapeutic agents. The increasing significance of this class of drugs requires significant investment in the development of quality control methods. The determination of the many degradation pathways of such complex molecules presents a significant challenge. However, an understanding of the potential impurities that may arise is necessary to continue to advance these powerful new therapeutics. In this study, four different antisense oligonucleotides representing several generations of oligonucleotide therapeutic agents were evaluated under various stress conditions (pH, thermal, and oxidative stress) using ion-pairing reversed-phase liquid chromatography tandem mass spectrometry (IP-RPLC-MS/MS) to provide in-depth characterization and identification of the degradation products. The oligonucleotide samples were stressed under different pH values at 45 and 90 °C. The main degradation products were observed to be losses of nucleotide moieties from the 3'- and 5'-terminus, depurination, formation of terminal phosphorothioates, and production of ribose, ribophosphorothioates (Rp), and phosphoribophosphorothioates (pRp). Moreover, the effects of different concentrations of hydrogen peroxide were studied resulting in primarily extensive desulfurization and subsequent oxidation of the phosphorothioate linkage to produce the corresponding phosphodiester. The reaction kinetics for the degradation of the oligonucleotides under the different stress conditions were studied and were found to follow pseudo-first-order kinetics. Differences in rates exist even for oligonucleotides of similar length but consisting of different sequences. Graphical abstract Identification of degradation products across several generations of oligonucleotide therapeutics using LC-MS.

  19. Genetic doping and health damages.

    Science.gov (United States)

    Fallahi, Aa; Ravasi, Aa; Farhud, Dd

    2011-01-01

    Use of genetic doping or gene transfer technology will be the newest and the lethal method of doping in future and have some unpleasant consequences for sports, athletes, and outcomes of competitions. The World Anti-Doping Agency (WADA) defines genetic doping as "the non-therapeutic use of genes, genetic elements, and/or cells that have the capacity to enhance athletic performance ". The purpose of this review is to consider genetic doping, health damages and risks of new genes if delivered in athletes. This review, which is carried out by reviewing relevant publications, is primarily based on the journals available in GOOGLE, ELSEVIER, PUBMED in fields of genetic technology, and health using a combination of keywords (e.g., genetic doping, genes, exercise, performance, athletes) until July 2010. There are several genes related to sport performance and if they are used, they will have health risks and sever damages such as cancer, autoimmunization, and heart attack.

  20. [Diabetic retinopathy: pathogenesis and therapeutic implications].

    Science.gov (United States)

    Pelikánová, Terezie

    Diabetic retinopathy (DR) develops in patients with both type 1 and type 2 diabetes and is the major cause of vision loss and blindness in the working population. The main risk factor of DR is hyperglycemia accompanied by enhanced mitochondrial production of reactive oxygen species and oxidative stress, formation of advanced glycation end products (AGE) and hexosamines, increase in polyol metabolism of glucose. The severity of vascular injury depends on the individual genetic background and is modified by other epigenetic, metabolic and haemodynamic factors, including hypertension, dyslipidemia and oxidative stress. In diabetes, damage to the retina occurs in the vasculature (endothelial cells and pericytes), neurons and glia, pigment epithelial cells and infiltrating immunocompetent cells: monocytes, granulocytes, lymfocytes. These activated cells change the production pattern of a number of mediators such as growth factors, proinflammatory cytokines, vasoactive molecules, coagulation factors and adhesion molecules resulting in increased blood flow, increased capillary permeability, proliferation of extracellular matrix and thickening of basal membranes, altered cell turnover (apoptosis, proliferation, hypertrophy), procoagulant and proaggregant pattern, and finally in angiogenesis and tissue remodelling. Brain, liver, adipose tissue, GUT, skeletal muscle and other tissues could be another source of mediators. Therapeutic approaches used for patients with or at risk for diabetic retinopathy include drug therapy to reduce modifiable risk factors, laser photocoagulation, intravitreous administration of anti-VEGF agents/steroids and intraocular surgery. Screening plays an important role in early detection and intervention to prevent the progression of diabetic retinopathy. Described insights into pathophysiological mechanisms responsible for DR, could help in the development of more targeted approach for prevention and treatment of diabetic retinopathy. anti

  1. Oral Polypodium leucotomos extract decreases ultraviolet-induced damage of human skin

    NARCIS (Netherlands)

    Middelkamp-Hup, Maritza A.; Pathak, Madhu A.; Parrado, Concepcion; Goukassian, David; Rius-Díaz, Francisca; Mihm, Martín C.; Fitzpatrick, Thomas B.; González, Salvador

    2004-01-01

    BACKGROUND: UV radiation induces damage to human skin. Protection of skin by an oral photoprotective agent would have substantial benefits. Objective We investigated the photoprotective effect of oral administration of an extract of the natural antioxidant Polypodium leucotomos (PL). METHODS: A

  2. Human Salivary Gland Stem Cells Functionally Restore Radiation Damaged Salivary Glands

    DEFF Research Database (Denmark)

    Pringle, Sarah; Maimets, Martti; van der Zwaag, Marianne

    2016-01-01

    Adult stem cells are often touted as therapeutic agents in the regenerative medicine field, however data detailing both the engraftment and functional capabilities of solid tissue derived human adult epithelial stem cells is scarce. Here we show the isolation of adult human salivary gland (SG) st...... for the first time that salispheres cultured from human SGs contain stem/progenitor cells capable of self-renewal and differentiation and rescue of saliva production. Our study underpins the therapeutic promise of salisphere cell therapy for the treatment of xerostomia....

  3. Will biofilm disassembly agents make it to market?

    Science.gov (United States)

    Romero, Diego; Kolter, Roberto

    2011-07-01

    Nearly 12 years after promising results suggested that antibiofilm agents might be developed into novel therapeutics, there are no such products on the market. In our opinion, the reasons for this have been predominantly economic. Recent developments, however, suggest that there could still be emerging opportunities for the developments of such products. Copyright © 2011 Elsevier Ltd. All rights reserved.

  4. Oxidative stress/damage induces multimerization and interaction of Fanconi anemia proteins.

    Science.gov (United States)

    Park, Su-Jung; Ciccone, Samantha L M; Beck, Brian D; Hwang, Byounghoon; Freie, Brian; Clapp, D Wade; Lee, Suk-Hee

    2004-07-16

    Fanconi anemia (FANC) is a heterogeneous genetic disorder characterized by a hypersensitivity to DNA-damaging agents, chromosomal instability, and defective DNA repair. Eight FANC genes have been identified so far, and five of them (FANCA, -C, -E, -F, and -G) assemble in a multinuclear complex and function at least in part in a complex to activate FANCD2 by monoubiquitination. Here we show that FANCA and FANCG are redox-sensitive proteins that are multimerized and/or form a nuclear complex in response to oxidative stress/damage. Both FANCA and FANCG proteins exist as monomers under non-oxidizing conditions, whereas they become multimers following H2O2 treatment. Treatment of cells with oxidizing agent not only triggers the multimeric complex of FANCA and FANCG in vivo but also induces the interaction between FANCA and FANCG. N-Ethylmaleimide treatment abolishes multimerization and interaction of FANCA and FANCG in vitro. Taken together, our results lead us to conclude that FANCA and FANCG uniquely respond to oxidative damage by forming complex(es) via intermolecular disulfide linkage(s), which may be crucial in forming such complexes and in determining their function.

  5. The human cyclin B1 protein modulates sensitivity of DNA mismatch repair deficient prostate cancer cell lines to alkylating agents.

    Science.gov (United States)

    Rasmussen, L J; Rasmussen, M; Lützen, A; Bisgaard, H C; Singh, K K

    2000-05-25

    DNA damage caused by alkylating agents results in a G2 checkpoint arrest. DNA mismatch repair (MMR) deficient cells are resistant to killing by alkylating agents and are unable to arrest the cell cycle in G2 phase after alkylation damage. We investigated the response of two MMR-deficient prostate cancer cell lines DU145 and LNCaP to the alkylating agent MNNG. Our studies reveal that DU145 cancer cells are more sensitive to killing by MNNG than LNCaP. Investigation of the underlying reasons for lower resistance revealed that the DU145 cells contain low endogenous levels of cyclin B1. We provide direct evidence that the endogenous level of cyclin B1 modulates the sensitivity of MMR-deficient prostate cancer cells to alkylating agents.

  6. Glyoxylate as a reducing agent for manganese(III) in salen scaffold ...

    Indian Academy of Sciences (India)

    being the monohydrate gem-diol forms) followed by the slow electron transfer ... stress and implicated as possible therapeutic agents .... excess HGl at different pHs (1.8–2.5) were set aside ...... sion (UGC), New Delhi in terms of a Teacher Fel-.

  7. Toxin-Based Therapeutic Approaches

    Science.gov (United States)

    Shapira, Assaf; Benhar, Itai

    2010-01-01

    Protein toxins confer a defense against predation/grazing or a superior pathogenic competence upon the producing organism. Such toxins have been perfected through evolution in poisonous animals/plants and pathogenic bacteria. Over the past five decades, a lot of effort has been invested in studying their mechanism of action, the way they contribute to pathogenicity and in the development of antidotes that neutralize their action. In parallel, many research groups turned to explore the pharmaceutical potential of such toxins when they are used to efficiently impair essential cellular processes and/or damage the integrity of their target cells. The following review summarizes major advances in the field of toxin based therapeutics and offers a comprehensive description of the mode of action of each applied toxin. PMID:22069564

  8. Reactivating p53 and Inducing Tumor Apoptosis (RITA) Enhances the Response of RITA-Sensitive Colorectal Cancer Cells to Chemotherapeutic Agents 5-Fluorouracil and Oxaliplatin.

    Science.gov (United States)

    Wiegering, Armin; Matthes, Niels; Mühling, Bettina; Koospal, Monika; Quenzer, Anne; Peter, Stephanie; Germer, Christoph-Thomas; Linnebacher, Michael; Otto, Christoph

    2017-04-01

    Colorectal carcinoma (CRC) is the most common cancer of the gastrointestinal tract with frequently dysregulated intracellular signaling pathways, including p53 signaling. The mainstay of chemotherapy treatment of CRC is 5-fluorouracil (5FU) and oxaliplatin. The two anticancer drugs mediate their therapeutic effect via DNA damage-triggered signaling. The small molecule reactivating p53 and inducing tumor apoptosis (RITA) is described as an activator of wild-type and reactivator of mutant p53 function, resulting in elevated levels of p53 protein, cell growth arrest, and cell death. Additionally, it has been shown that RITA can induce DNA damage signaling. It is expected that the therapeutic benefits of 5FU and oxaliplatin can be increased by enhancing DNA damage signaling pathways. Therefore, we highlighted the antiproliferative response of RITA alone and in combination with 5FU or oxaliplatin in human CRC cells. A panel of long-term established CRC cell lines (n=9) including p53 wild-type, p53 mutant, and p53 null and primary patient-derived, low-passage cell lines (n=5) with different p53 protein status were used for this study. A substantial number of CRC cells with pronounced sensitivity to RITA (IC 50 RITA appeared independent of p53 status and was associated with an increase in antiproliferative response to 5FU and oxaliplatin, a transcriptional increase of p53 targets p21 and NOXA, and a decrease in MYC mRNA. The effect of RITA as an inducer of DNA damage was shown by a strong elevation of phosphorylated histone variant H2A.X, which was restricted to RITA-sensitive cells. Our data underline the primary effect of RITA, inducing DNA damage, and demonstrate the differential antiproliferative effect of RITA to CRC cells independent of p53 protein status. We found a substantial number of RITA-sensitive CRC cells within both panels of established CRC cell lines and primary patient-derived CRC cell lines (6/14) that provide a rationale for combining RITA with 5FU or

  9. Myostatin as a Marker for Doxorubicin Induced Cardiac Damage.

    Science.gov (United States)

    Kesik, Vural; Honca, Tevfik; Gulgun, Mustafa; Uysal, Bulent; Kurt, Yasemin Gulcan; Cayci, Tuncer; Babacan, Oguzhan; Gocgeldi, Ercan; Korkmazer, Nadir

    2016-01-01

    Doxorubicin (DXR) is an effective chemotherapeutic agent but causes severe cardiac failure over known doses. Thus, early detection and prevention of cardiac damage is important. Various markers have been tested for early detection of cardiac damage. Myostatin is a protein produced in skeletal muscle cells inhibits muscle differentiation and growth during myogenesis. We evaluated the role of myostatin as a marker for showing DXR induced cardiac damage and compared with well known cardiac markers like NT-proBNP, hs-TnT and CK in a rat model of chronic DXR cardiotoxicity. Myostatin, NT-proBNP, and hs-TnT but not CK rose significantly during DXR treatment. Myostatin can be used as an early marker of DXR induced cardiotoxicity. © 2016 by the Association of Clinical Scientists, Inc.

  10. Therapeutic Symptomatic Strategies in the Parasomnias.

    Science.gov (United States)

    Manni, Raffaele; Toscano, Gianpaolo; Terzaghi, Michele

    2018-06-05

    The purpose of this review was to discuss the currently available pharmacologic and non-pharmacologic treatment options for parasomnias. Recent pathophysiological findings about sleep structure in parasomnias helped understanding several drug mechanisms of action. Serotoninergic theory accounts for the effect of serotoninergic drugs. Study about spectral analysis of sleep showed the effect of clonazepam on spectral bands. Cannabinoids proved to be effective in some of parasomnias, as in many other neurological disorders. A series of therapeutic strategies were analyzed and compared. Benzodiazepines, antidepressant drugs, and L-5-hydroxytryptophan may be beneficial in DOA. SSRI and topiramate are effective in SRED. RBD responds to clonazepam, melatonin, and to a lesser extent to dopaminergic and anticholinergic agents. Prazosin and cannabinoids are effective in nightmare disorder. Sleep paralysis may respond to antidepressant agents. Tricyclic antidepressant may be effective in sleep-related hallucinations and exploding head syndrome. Sleep enuresis may be successfully treated with desmopressin, anticholinergic drugs, and imipramine.

  11. Challenges to oligonucleotides-based therapeutics for Duchenne muscular dystrophy

    Directory of Open Access Journals (Sweden)

    Goyenvalle Aurélie

    2011-02-01

    Full Text Available Abstract Antisense oligonucleotides are short nucleic acids designed to bind to specific messenger RNAs in order to modulate splicing patterns or inhibit protein translation. As such, they represent promising therapeutic tools for many disorders and have been actively developed for more than 20 years as a form of molecular medicine. Although significant progress has been made in developing these agents as drugs, they are yet not recognized as effective therapeutics and several hurdles remain to be overcome. Within the last few years, however, the prospect of successful oligonucleotides-based therapies has moved a step closer, in particular for Duchenne muscular dystrophy. Clinical trials have recently been conducted for this myopathy, where exon skipping is being used to achieve therapeutic outcomes. In this review, the recent developments and clinical trials using antisense oligonucleotides for Duchenne muscular dystrophy are discussed, with emphasis on the challenges ahead for this type of therapy, especially with regards to delivery and regulatory issues.

  12. Studies on marine oil spills and their ecological damage

    Science.gov (United States)

    Mei, Hong; Yin, Yanjie

    2009-09-01

    The sources of marine oil spills are mainly from accidents of marine oil tankers or freighters, marine oil-drilling platforms, marine oil pipelines, marine oilfields, terrestrial pollution, oil-bearing atmosphere, and offshore oil production equipment. It is concluded upon analysis that there are two main reasons for marine oil spills: (I) The motive for huge economic benefits of oil industry owners and oil shipping agents far surpasses their sense of ecological risks. (II) Marine ecological safety has not become the main concern of national security. Oil spills are disasters because humans spare no efforts to get economic benefits from oil. The present paper draws another conclusion that marine ecological damage caused by oil spills can be roughly divided into two categories: damage to marine resource value (direct value) and damage to marine ecosystem service value (indirect value). Marine oil spills cause damage to marine biological, fishery, seawater, tourism and mineral resources to various extents, which contributes to the lower quality and value of marine resources.

  13. Gelatin sponge particle used as an embolic agent in transcatheter arterial chemoembolization treatment for primary hepatocellular carcinoma: its current situation in research

    International Nuclear Information System (INIS)

    Ao Jin; Zhang Yuewei; Xu Ke

    2011-01-01

    Transcatheter arterial chemoembolization (TACE) is one of the most commonly used therapeutic procedures for primary hepatocellular carcinoma (HCC). As an important and easily-available embolic agent, gelatin sponge (Gelfoam) particles have been constantly and widely employed in clinical practice. Various types of embolic agents have been continuously developed and effectively used in TACE for liver cancers. For recent years, great progress has been made in the clinical use of gelatin sponge particles, as the most traditional embolic agent, in the interventional therapeutic field for HCC. This article aims to make a comprehensive review about gelatin sponge. (authors)

  14. Terapia com agentes biológicos na criança e no adolescente Treatment with biologic agents in child and adolescent

    Directory of Open Access Journals (Sweden)

    Ricardo Maisse Suehiro

    2010-06-01

    Full Text Available OBJETIVO: Revisar os mecanismos fisiopatológicos e novos alvos terapêuticos, os agentes biológicos disponíveis, principais indicações e a evidência científica atual para o uso de terapias biológicas na população pediátrica. FONTES DE DADOS: Pesquisa na base de dados Medline e SciELO, nas línguas inglesa e portuguesa, entre 2000 e 2009. As palavras-chave usadas foram "agentes biológicos", "crianças" e "adolescentes". SÍNTESE DOS DADOS: Os agentes biológicos são uma importante opção terapêutica para tratar as doenças autoimunes refratárias às terapias convencionais na infância e na adolescência. Com exceção da artrite idiopática juvenil, a maioria dos estudos em outras doenças autoimunes não é controlada. CONCLUSÕES: Os agentes biológicos têm demonstrado eficácia no tratamento de doenças autoimunes pediátricas como artrite idiopática juvenil, miopatias idiopáticas inflamatórias, lúpus eritematoso juvenil, vasculites, uveítes crônicas, doenças inflamatórias intestinais e púrpura trombocitopênica imune crônica, assim como no linfoma não-Hodgkin. Considerando-se o custo elevado e os potenciais eventos adversos, o uso desses agentes deve ser individualizado e acompanhado por especialista.OBJECTIVE: To review the physiopathology and new therapeutical targets, the available biologic agents, the main indications and the current scientific evidence for the use of biological therapies in the pediatric population. DATA SOURCES: A bibliographical search was obtained from Medline and SciELO databases in English and Portuguese from 2000 to 2009. The key-words included were "biologic agent", "children" and "adolescent". DATA SYNTHESIS: Biologic agents are important therapeutic options to treat refractory autoimmune diseases to conventional therapies in childhood and adolescence. Excluding juvenile idiopathic arthritis, the majority of studies in other autoimmune diseases are uncontrolled trials. CONCLUSIONS

  15. 4beta-Hydroxywithanolide E from Physalis peruviana (golden berry) inhibits growth of human lung cancer cells through DNA damage, apoptosis and G2/M arrest.

    Science.gov (United States)

    Yen, Ching-Yu; Chiu, Chien-Chih; Chang, Fang-Rong; Chen, Jeff Yi-Fu; Hwang, Chi-Ching; Hseu, You-Cheng; Yang, Hsin-Ling; Lee, Alan Yueh-Luen; Tsai, Ming-Tz; Guo, Zong-Lun; Cheng, Yu-Shan; Liu, Yin-Chang; Lan, Yu-Hsuan; Chang, Yu-Ching; Ko, Ying-Chin; Chang, Hsueh-Wei; Wu, Yang-Chang

    2010-02-18

    The crude extract of the fruit bearing plant, Physalis peruviana (golden berry), demonstrated anti-hepatoma and anti-inflammatory activities. However, the cellular mechanism involved in this process is still unknown. Herein, we isolated the main pure compound, 4beta-Hydroxywithanolide (4betaHWE) derived from golden berries, and investigated its antiproliferative effect on a human lung cancer cell line (H1299) using survival, cell cycle, and apoptosis analyses. An alkaline comet-nuclear extract (NE) assay was used to evaluate the DNA damage due to the drug. It was shown that DNA damage was significantly induced by 1, 5, and 10 microg/mL 4betaHWE for 2 h in a dose-dependent manner (p < 0.005). A trypan blue exclusion assay showed that the proliferation of cells was inhibited by 4betaHWE in both dose- and time-dependent manners (p < 0.05 and 0.001 for 24 and 48 h, respectively). The half maximal inhibitory concentrations (IC50) of 4betaHWE in H1299 cells for 24 and 48 h were 0.6 and 0.71 microg/mL, respectively, suggesting it could be a potential therapeutic agent against lung cancer. In a flow cytometric analysis, 4betaHWE produced cell cycle perturbation in the form of sub-G1 accumulation and slight arrest at the G2/M phase with 1 microg/mL for 12 and 24 h, respectively. Using flow cytometric and annexin V/propidium iodide immunofluorescence double-staining techniques, these phenomena were proven to be apoptosis and complete G2/M arrest for H1299 cells treated with 5 microg/mL for 24 h. In this study, we demonstrated that golden berry-derived 4betaHWE is a potential DNA-damaging and chemotherapeutic agent against lung cancer.

  16. 4β-Hydroxywithanolide E from Physalis peruviana (golden berry) inhibits growth of human lung cancer cells through DNA damage, apoptosis and G2/M arrest

    International Nuclear Information System (INIS)

    Yen, Ching-Yu; Guo, Zong-Lun; Cheng, Yu-Shan; Liu, Yin-Chang; Lan, Yu-Hsuan; Chang, Yu-Ching; Ko, Ying-Chin; Chang, Hsueh-Wei; Wu, Yang-Chang; Chiu, Chien-Chih; Chang, Fang-Rong; Chen, Jeff Yi-Fu; Hwang, Chi-Ching; Hseu, You-Cheng; Yang, Hsin-Ling; Lee, Alan Yueh-Luen; Tsai, Ming-Tz

    2010-01-01

    The crude extract of the fruit bearing plant, Physalis peruviana (golden berry), demonstrated anti-hepatoma and anti-inflammatory activities. However, the cellular mechanism involved in this process is still unknown. Herein, we isolated the main pure compound, 4β-Hydroxywithanolide (4βHWE) derived from golden berries, and investigated its antiproliferative effect on a human lung cancer cell line (H1299) using survival, cell cycle, and apoptosis analyses. An alkaline comet-nuclear extract (NE) assay was used to evaluate the DNA damage due to the drug. It was shown that DNA damage was significantly induced by 1, 5, and 10 μg/mL 4βHWE for 2 h in a dose-dependent manner (p < 0.005). A trypan blue exclusion assay showed that the proliferation of cells was inhibited by 4βHWE in both dose- and time-dependent manners (p < 0.05 and 0.001 for 24 and 48 h, respectively). The half maximal inhibitory concentrations (IC 50 ) of 4βHWE in H1299 cells for 24 and 48 h were 0.6 and 0.71 μg/mL, respectively, suggesting it could be a potential therapeutic agent against lung cancer. In a flow cytometric analysis, 4βHWE produced cell cycle perturbation in the form of sub-G 1 accumulation and slight arrest at the G 2 /M phase with 1 μg/mL for 12 and 24 h, respectively. Using flow cytometric and annexin V/propidium iodide immunofluorescence double-staining techniques, these phenomena were proven to be apoptosis and complete G 2 /M arrest for H1299 cells treated with 5 μg/mL for 24 h. In this study, we demonstrated that golden berry-derived 4βHWE is a potential DNA-damaging and chemotherapeutic agent against lung cancer

  17. 4β-Hydroxywithanolide E from Physalis peruviana (golden berry) inhibits growth of human lung cancer cells through DNA damage, apoptosis and G2/M arrest

    Science.gov (United States)

    2010-01-01

    Background The crude extract of the fruit bearing plant, Physalis peruviana (golden berry), demonstrated anti-hepatoma and anti-inflammatory activities. However, the cellular mechanism involved in this process is still unknown. Methods Herein, we isolated the main pure compound, 4β-Hydroxywithanolide (4βHWE) derived from golden berries, and investigated its antiproliferative effect on a human lung cancer cell line (H1299) using survival, cell cycle, and apoptosis analyses. An alkaline comet-nuclear extract (NE) assay was used to evaluate the DNA damage due to the drug. Results It was shown that DNA damage was significantly induced by 1, 5, and 10 μg/mL 4βHWE for 2 h in a dose-dependent manner (p < 0.005). A trypan blue exclusion assay showed that the proliferation of cells was inhibited by 4βHWE in both dose- and time-dependent manners (p < 0.05 and 0.001 for 24 and 48 h, respectively). The half maximal inhibitory concentrations (IC50) of 4βHWE in H1299 cells for 24 and 48 h were 0.6 and 0.71 μg/mL, respectively, suggesting it could be a potential therapeutic agent against lung cancer. In a flow cytometric analysis, 4βHWE produced cell cycle perturbation in the form of sub-G1 accumulation and slight arrest at the G2/M phase with 1 μg/mL for 12 and 24 h, respectively. Using flow cytometric and annexin V/propidium iodide immunofluorescence double-staining techniques, these phenomena were proven to be apoptosis and complete G2/M arrest for H1299 cells treated with 5 μg/mL for 24 h. Conclusions In this study, we demonstrated that golden berry-derived 4βHWE is a potential DNA-damaging and chemotherapeutic agent against lung cancer. PMID:20167063

  18. Anticonvulsants for Nerve Agent-Induced Seizures: The Influence of the Therapeutic Dose of Atropine

    National Research Council Canada - National Science Library

    Shih, Tsung-Ming; Rowland, Tami C; McDonough, John H

    2007-01-01

    Two guinea pig models were used to study the anticonvulsant potency of diazepam, midazolam, and scopolamine against seizures induced by the nerve agents tabun, sarin, soman, cyclosarin, O-ethyl S-(2-(diisopropylamino)ethyl...

  19. Monkey brain damage from radiation in the therapeutic range

    International Nuclear Information System (INIS)

    Nakagaki, H.; Brunhart, G.; Kemper, T.L.; Caveness, W.F.

    1976-01-01

    Twelve Macaca mulatta monkeys received 200 rads of supervoltage radiation to the whole brain per day, 5 days a week. The course in four monkeys was 4 weeks for a total dose of 4000 rads; in four monkeys, 6 weeks for 6000 rads; and in four monkeys, 8 weeks for 8000 rads. Four unirradiated monkeys served as controls. One from each group, sacrificed at 6 and 12 months from start of irradiation, is reported here. The results from 4000 rads were negligible; those from 8000 rads, profound, with gross brain destruction. The results from 6000 rads, within the therapeutic range, included at 6 months punctate necrotic lesions, 1 mm or less, widely scattered but with a predilection for the forebrain white matter. The reaction to these lesions ranged from an early macrophage response to calcification. Some were accompanied by focal edema. There were occasional examples of vascular endothelial proliferation. In addition, there were patches of dilated capillaries or telangiectasia. Twelve months after 6000 rads there were a few mineralized lesions and innumerable minute deposits of calcium and iron. A more active process was suggested by widely disseminated areas of telangiectasia, 6 to 12 mm in extent. The clinical course from this exposure included papilledema from the third to the sixth month and depressed visual evoked response accompanied by delta activity in the electroencephalogram from the sixth to the twelfth month

  20. Hepatitis B core protein as a therapeutic target.

    Science.gov (United States)

    Mak, Lung-Yi; Wong, Danny Ka-Ho; Seto, Wai-Kay; Lai, Ching-Lung; Yuen, Man Fung

    2017-12-01

    Chronic hepatitis B virus (HBV) infection is difficult to cure, due to the presence of covalently-closed-circular DNA and virus-mediated blunting of host immune response. Existing therapies with nucleos(t)ide analogue or pegylated-interferon are not sufficient to achieve a high rate of HBV surface antigen seroclearance, a more desirable treatment outcome. Novel therapeutic agents targeting alternative viral replication steps are being developed. In this review, we will discuss the hepatitis B core antigen (HBcAg) as a therapeutic target. Areas covered: The basic structure and fundamental functions of HBcAg including nucleocapsid assembly, pre-genomic RNA encapsidation, reverse transcription, virion formation, cccDNA amplification, immune response regulation, and HBx protein interaction will be reviewed. Most of these are identified as therapeutic targets and tested in in vitro and in vivo studies, although clinical trials are scanty. Among the different components, the core protein allosteric modulators (CpAM) have been most widely investigated and appear promising in clinical trials. Expert opinion: The multiple and essential functions of HBcAg for HBV life cycle are important and attractive targets for HBV therapeutic interventions. Controlled trials involving CpAM are awaited. Apart from CpAM, drugs directed against different functions of HBcAg may be further explored to maximize the chance of cure.